WorldWideScience

Sample records for models differ greatly

  1. GREAT Process Modeller user manual

    OpenAIRE

    Rueda, Urko; España, Sergio; Ruiz, Marcela

    2015-01-01

    This report contains instructions to install, uninstall and use GREAT Process Modeller, a tool that supports Communication Analysis, a communication-oriented business process modelling method. GREAT allows creating communicative event diagrams (i.e. business process models), specifying message structures (which describe the messages associated to each communicative event), and automatically generating a class diagram (representing the data model of an information system that would support suc...

  2. A new isolation with migration model along complete genomes infers very different divergence processes among closely related great ape species.

    Directory of Open Access Journals (Sweden)

    Thomas Mailund

    Full Text Available We present a hidden Markov model (HMM for inferring gradual isolation between two populations during speciation, modelled as a time interval with restricted gene flow. The HMM describes the history of adjacent nucleotides in two genomic sequences, such that the nucleotides can be separated by recombination, can migrate between populations, or can coalesce at variable time points, all dependent on the parameters of the model, which are the effective population sizes, splitting times, recombination rate, and migration rate. We show by extensive simulations that the HMM can accurately infer all parameters except the recombination rate, which is biased downwards. Inference is robust to variation in the mutation rate and the recombination rate over the sequence and also robust to unknown phase of genomes unless they are very closely related. We provide a test for whether divergence is gradual or instantaneous, and we apply the model to three key divergence processes in great apes: (a the bonobo and common chimpanzee, (b the eastern and western gorilla, and (c the Sumatran and Bornean orang-utan. We find that the bonobo and chimpanzee appear to have undergone a clear split, whereas the divergence processes of the gorilla and orang-utan species occurred over several hundred thousands years with gene flow stopping quite recently. We also apply the model to the Homo/Pan speciation event and find that the most likely scenario involves an extended period of gene flow during speciation.

  3. Regional Personality Differences in Great Britain

    Science.gov (United States)

    Rentfrow, Peter J.; Jokela, Markus; Lamb, Michael E.

    2015-01-01

    Recent investigations indicate that personality traits are unevenly distributed geographically, with some traits being more prevalent in certain places than in others. The geographical distributions of personality traits are associated with a range of important political, economic, social, and health outcomes. The majority of research on this subject has focused on the geographical distributions and macro-level correlates of personality across nations or regions of the United States. The aim of the present investigation was to replicate and extend that past work by examining regional personality differences in Great Britain. Using a sample of nearly 400,000 British residents, we mapped the geographical distributions of the Big Five Personality traits across 380 Local Authority Districts and examined the associations with important political, economic, social, and health outcomes. The results revealed distinct geographical clusters, with neighboring regions displaying similar personality characteristics, and robust associations with the macro-level outcome variables. Overall, the patterns of results were similar to findings from past research. PMID:25803819

  4. Modeling toxaphene behavior in the Great Lakes.

    Science.gov (United States)

    Xia, Xiaoyan; Hopke, Philip K; Holsen, Thomas M; Crimmins, Bernard S

    2011-01-15

    Chlorinated camphenes, toxaphene, are persistent organic pollutants of concern in the Great Lakes since elevated concentrations are found in various media throughout the system. While concentrations have decreased since their peak values in the 1970s and 80s, recent measurements have shown that the rate of this decline in Lake Superior has decreased significantly. This modeling study focused on toxaphene cycling in the Great Lakes and was performed primarily to determine if elevated water and fish concentrations in Lake Superior can be explained by physical differences among the lakes. Specifically, the coastal zone model for persistent organic pollutants (CoZMo-POP), a fugacity-based multimedia fate model, was used to calculate toxaphene concentrations in the atmosphere, water, soil, sediment, and biota. The performance of the model was evaluated by comparing calculated and reported concentrations in these compartments. In general, simulated and observed concentrations agree within one order of magnitude. Both model results and observed values indicate that toxaphene concentrations have declined in water and biota since the 1980s primarily as the result of decreased atmospheric deposition rates. Overall the model results suggest that the CoZMo-POP2 model does a reasonable job in simulating toxaphene variations in the Great Lakes basin. The results suggest that the recent findings of higher toxaphene concentrations in Lake Superior can be explained by differences in the physical properties of the lake (primarily large volume, large residence time and cold temperatures) compared to the lower lakes and increased recent inputs are not needed to explain the measured values.

  5. Great expectations: different high-risk activities satisfy different motives.

    Science.gov (United States)

    Barlow, Matthew; Woodman, Tim; Hardy, Lew

    2013-09-01

    Research on people's motives for engaging in high-risk activities has typically been viewed through the single-focused lens of sensation seeking. We provide evidence that comprehensively challenges that view. First, we develop and confirm the structure of a 3-factor measure of motives: the Sensation Seeking, Emotion Regulation, and Agency Scale (SEAS; Study 1). We then use the SEAS to provide evidence of differential motives for 2 high-risk activities: skydiving and mountaineering. The motive for skydiving is strongly associated with sensation seeking; the motive for mountaineering is strongly associated with emotion regulation and agency but not with sensation seeking (Study 2). We also show that these conclusions cannot be drawn from existing measures of personality and sensation seeking (Study 3). Finally, individuals who are motivated by emotion regulation and agency needs also have greater expectations regarding their emotion regulation and agency. It is these greater expectations that most successfully discriminate mountaineers from skydivers and control participants (Study 4). It is concluded that researchers should no longer consider risk takers as a homogenous sensation-seeking group and that they should consider risk taking as a potential model of human endeavor. The SEAS can be used as a measure of motives for behavior whenever sensation seeking, agency, or emotion regulation is thought to be at the core of such motives, and the results are discussed in the context of encouraging personality researchers to consider the specific spontaneous behaviors that motivate different people.

  6. Why the Sacramento Delta area differs from other parts of the great valley: Numerical modeling of thermal structure and thermal subsidence of forearc basins

    Science.gov (United States)

    Mikhailov, V. O.; Parsons, T.; Simpson, R. W.; Timoshkina, E. P.; Williams, C.

    2007-01-01

    Data on present-day heat flow, subsidence history, and paleotemperature for the Sacramento Delta region, California, have been employed to constrain a numerical model of tectonic subsidence and thermal evolution of forearc basins. The model assumes an oceanic basement with an initial thermal profile dependent on its age subjected to refrigeration caused by a subducting slab. Subsidence in the Sacramento Delta region appears to be close to that expected for a forearc basin underlain by normal oceanic lithosphere of age 150 Ma, demonstrating that effects from both the initial thermal profile and the subduction process are necessary and sufficient. Subsidence at the eastern and northern borders of the Sacramento Valley is considerably less, approximating subsidence expected from the dynamics of the subduction zone alone. These results, together with other geophysical data, show that Sacramento Delta lithosphere, being thinner and having undergone deeper subsidence, must differ from lithosphere of the transitional type under other parts of the Sacramento Valley. Thermal modeling allows evaluation of the rheological properties of the lithosphere. Strength diagrams based on our thermal model show that, even under relatively slow deformation (10-17 s-1), the upper part of the delta crystalline crust (down to 20-22 km) can fail in brittle fashion, which is in agreement with deeper earthquake occurrence. Hypocentral depths of earthquakes under the Sacramento Delta region extend to nearly 20 km, whereas, in the Coast Ranges to the west, depths are typically less than 12-15 km. The greater width of the seismogenic zone in this area raises the possibility that, for fault segments of comparable length, earthquakes of somewhat greater magnitude might occur than in the Coast Ranges to the west.

  7. Microwave emissivity of freshwater ice, Part II: Modelling the Great Bear and Great Slave Lakes

    CERN Document Server

    Mills, Peter

    2012-01-01

    Lake ice within three Advanced Microwave Scanning Radiometer on EOS (AMSR-E) pixels over the Great Bear and Great Slave Lakes have been simulated with the Canadian Lake Ice Model (CLIMo). The resulting thicknesses and temperatures were fed to a radiative transfer-based ice emissivity model and compared to the satellite measurements at three frequencies---6.925 GHz, 10.65 GHz and 18.7 GHz. Excluding the melt season, the model was found to have strong predictive power, returning a correlation of 0.926 and a residual of 0.78 Kelvin at 18 GHz, vertical polarization. Discrepencies at melt season are thought to be caused by the presence of dirt in the snow cover which makes the microwave signature more like soil rather than ice. Except at 18 GHz, all results showed significant bias compared to measured values. Further work needs to be done to determine the source of this bias.

  8. Models-Based Practice: Great White Hope or White Elephant?

    Science.gov (United States)

    Casey, Ashley

    2014-01-01

    Background: Many critical curriculum theorists in physical education have advocated a model- or models-based approach to teaching in the subject. This paper explores the literature base around models-based practice (MBP) and asks if this multi-models approach to curriculum planning has the potential to be the great white hope of pedagogical change…

  9. Models-Based Practice: Great White Hope or White Elephant?

    Science.gov (United States)

    Casey, Ashley

    2014-01-01

    Background: Many critical curriculum theorists in physical education have advocated a model- or models-based approach to teaching in the subject. This paper explores the literature base around models-based practice (MBP) and asks if this multi-models approach to curriculum planning has the potential to be the great white hope of pedagogical change…

  10. A carbon balance model for the great dismal swamp ecosystem

    Science.gov (United States)

    Sleeter, Rachel; Sleeter, Benjamin M.; Williams, Brianna; Hogan, Dianna; Hawbaker, Todd J.; Zhu, Zhiliang

    2017-01-01

    BackgroundCarbon storage potential has become an important consideration for land management and planning in the United States. The ability to assess ecosystem carbon balance can help land managers understand the benefits and tradeoffs between different management strategies. This paper demonstrates an application of the Land Use and Carbon Scenario Simulator (LUCAS) model developed for local-scale land management at the Great Dismal Swamp National Wildlife Refuge. We estimate the net ecosystem carbon balance by considering past ecosystem disturbances resulting from storm damage, fire, and land management actions including hydrologic inundation, vegetation clearing, and replanting.ResultsWe modeled the annual ecosystem carbon stock and flow rates for the 30-year historic time period of 1985–2015, using age-structured forest growth curves and known data for disturbance events and management activities. The 30-year total net ecosystem production was estimated to be a net sink of 0.97 Tg C. When a hurricane and six historic fire events were considered in the simulation, the Great Dismal Swamp became a net source of 0.89 Tg C. The cumulative above and below-ground carbon loss estimated from the South One and Lateral West fire events totaled 1.70 Tg C, while management activities removed an additional 0.01 Tg C. The carbon loss in below-ground biomass alone totaled 1.38 Tg C, with the balance (0.31 Tg C) coming from above-ground biomass and detritus.ConclusionsNatural disturbances substantially impact net ecosystem carbon balance in the Great Dismal Swamp. Through alternative management actions such as re-wetting, below-ground biomass loss may have been avoided, resulting in the added carbon storage capacity of 1.38 Tg. Based on two model assumptions used to simulate the peat system, (a burn scar totaling 70 cm in depth, and the soil carbon accumulation rate of 0.36 t C/ha−1/year−1 for Atlantic white cedar), the total soil carbon loss from the

  11. Great Plains ASPEN model development: Phosam section. Final topical report

    Energy Technology Data Exchange (ETDEWEB)

    Stern, S S; Kirman, J J

    1985-02-01

    An ASPEN model has been developed of the PHOSAM Section, Section 4600, of the Great Plains Gasification Plant. The bases for this model are the process description given in Section 6.18 of the Great Plains Project Management Plan and the Lummus Phosam Schematic Process Flow Diagram, Dwg. No. SKD-7102-IM-O. The ASPEN model that has been developed contains the complete set of components that are assumed to be in the gasifier effluent. The model is primarily a flowsheet simulation that will give the material and energy balance and equipment duties for a given set of process conditions. The model is unable to predict fully changes in process conditions that would result from load changes on equipment of fixed sizes, such as a rating model would predict. The model can be used to simulate the steady-state operation of the plant at or near design conditions or to design other PHOSAM units. Because of the limited amount of process information that was available, several major process assumptions had to be made in the development of the flowsheet model. Patent literature was consulted to establish the ammonia concentration in the circulating fluid. Case studies were made with the ammonia content of the feed 25% higher and 25% lower than the base feed. Results of these runs show slightly lower recoveries of ammonia with less ammonia in the feed. As expected, the duties of the Stripper and Fractionator reboilers were higher with more ammonia in the feed. 63 references.

  12. Africa's Great Green Wall Initiative: a model for restoration success

    Science.gov (United States)

    Berrahmouni, Nora; Sacande, Moctar

    2014-05-01

    The Great Green Wall for the Sahara and the Sahel Initiative was launched to address the increasing challenges of land degradation, desertification and drought, climate change, food insecurity and poverty in more than 20 countries. Restoration of agro-sylvo-pastoral landscapes and degraded lands is one of the priority interventions initiated, enabling the springing up of green nests of life. When complete, the Great Green Wall of Africa will reverse the seemingly unstoppable desertification and address the development of its drylands' inhabitant rural communities. Today's planting of modest seedlings will grow into vast mosaics of forest and agroforestry landscapes and grasslands, which will provide essential ecosystem goods and services, restore lost livelihoods and create new wealth. The ambition of reforestation efforts within this initiative - the like of which the world has never seen before - sounds like an impossible dream. However, learning from past mistakes and capitalising on current advancement in science and technology, it is a reality that is taking root. Following a successful restoration model that RBG Kew experts have devised, we are helping to mobilise, train and support communities in four border regions in Burkina Faso, Mali and Niger. In collaboration with FAO, the Millennium Seed Bank Partnership is using its unique expertise to ensure that seeds of environmentally well-adapted and economically useful local species are collected and planted in communal gardens and village agroforestry systems managed by the communities themselves. In our first year, an estimated total of 162,000 seedlings and 61 kg of seeds from 40 useful native species, including grasses for livestock, have been planted to cover 237 ha of farmer-managed land in 19 villages. The keen interest it has created has indicated that these figures will rise five-fold in the second year. These green bricks are the foundations of the living wall that will eventually reach across the

  13. 3D Geologic Model of the Southern Great Basin

    Science.gov (United States)

    Wagoner, J. L.; Myers, S. C.

    2006-12-01

    We have constructed a regional 3D geologic model of the southern Great Basin, in support of a seismic wave propagation investigation of the 1993 Nonproliferation Experiment (NPE) at the Nevada Test Site (NTS). The model is centered on the NPE and spans longitude -119.5° to -112.6°, latitude 34.5° to 39.8°, and a depth from the surface to 150 km below sea level. Hence, the model includes the southern half of Nevada, as well as parts of eastern California, western Utah, and a portion of northwestern Arizona. The upper crust is constrained by geologic and geophysical studies, and the lower crust and upper mantle are constrained by geophysical studies. The upper crustal geologic units are Quaternary basin fill, Tertiary deposits, pre-Tertiary deposits, intrusive rocks, and calderas. The lower crust and upper mantle are parameterized with 8 layers, including the Moho. Detailed geologic data, including surface maps, borehole data, and geophysical surveys, were used to define the geology at the NTS. Digital geologic outcrop data were available for both Nevada and Arizona, whereas we scanned and hand digitized geologic maps for California and Utah. Published gravity data (2km spacing) were used to determine the thickness of the Cenozoic deposits and constrain the depth of the basins. The free surface is based on a 10m lateral resolution DEM at the NTS and a 90m resolution DEM elsewhere. The gross geophysical structure of the crust and upper mantle is taken from regional surface-wave studies. Variations in crustal thickness are based on receiver function analysis and a compilation of reflection/refraction studies. We used the Earthvision (Dynamic Graphics, Inc.) software to integrate the geologic and geophysical information into a model of x,y,z,p nodes, where p is an integer index representing the geologic unit. For regional seismic simulations we convert this realistic geologic model into elastic parameters. Upper crustal units are treated as seismically homogeneous

  14. Study Guide--What Great Principals Do Differently: Eighteen Things That Matter Most. Second Edition

    Science.gov (United States)

    Whitaker, Beth; Whitaker, Todd; Zoul, Jeffrey

    2012-01-01

    Designed to be used by facilitators and participants in seminars, book study groups, or other professional development events, this book guides critical thinking, collaboration, and professional growth based on the concepts in Todd Whitaker's best-selling title, "What Great Principals Do Differently" (2nd edition). Each chapter includes: (1) Key…

  15. Study Guide--What Great Teachers Do Differently: Seventeen Things That Matter Most. Second Edition

    Science.gov (United States)

    Whitaker, Beth; Whitaker, Todd

    2012-01-01

    Written to accompany the second edition of Todd Whitaker's best-selling title, "What Great Teachers Do Differently," this study guide can be used by facilitators and participants in seminars, book study groups, or other professional development events. The variety of activities and strategies in this book will help teachers engage in critical…

  16. President George Washington: A Timeless Model of Great Leadership

    Science.gov (United States)

    2011-04-29

    first president? I am interested in Washington because I wanted to know how he became such a great ,/ . ’ leader and how could that benefit me as a...Washington would be considered to have been homeschooled with augmentation from the local church/school -- with a focus on applied mathematics

  17. The 2010 Saturn's Great White Spot: Observations and models

    Science.gov (United States)

    Sanchez-Lavega, A.

    2011-12-01

    On December 5, 2010, a major storm erupted in Saturn's northern hemisphere at a planetographic latitude of 37.7 deg [1]. These phenomena are known as "Great White Spots" (GWS) and they have been observed once per Saturn year since the first case confidently reported in 1876. The last event occurred at Saturn's Equator in 1990 [2]. A GWS differs from similar smaller-scale storms in that it generates a planetary-scale disturbance that spreads zonally spanning the whole latitude band. We report on the evolution and motions of the 2010 GWS and its associated disturbance during the months following the outbreak, based mainly on high quality images obtained in the visual range submitted to the International Outer Planet Watch PVOL database [3], with the 1m telescope at Pic-du-Midi Observatory and the 2.2 m telescope at Calar Alto Observatory. The GWS "head source" extinguished by June 2011 implying that it survived about 6 months. Since this source is assumed to be produced by water moist convection, a reservoir of water vapor must exist at a depth of 10 bar and at the same time a disturbance producing the necessary convergence to trigger the ascending motions. The high temporal sampling and coverage allowed us to study the dynamics of the GWS in detail and the multi-wavelength observations provide information on its cloud top structure. We present non-linear simulations using the EPIC code of the evolution of the potential vorticity generated by a continuous Gaussian heat source extending from 10 bar to about 1 bar, that compare extraordinary well to the observed cloud field evolution. Acknowledgements: This work has been funded by Spanish MICIIN AYA2009-10701 with FEDER support and Grupos Gobierno Vasco IT-464-07. The presentation is done on behalf of the team listed in Reference [1]. [1]Sánchez-Lavega A., et al., Nature, 475, 71-74 (2011) [2]Sánchez-Lavega A., et al., Nature, 353, 397-401 (1991) [3]Hueso R., et al., Planet. Space Sci., 58, 1152-1159 (2010).

  18. Tissue differences in fragile X mosaics: Mosaicism in blood cells may differ greatly from skin

    Energy Technology Data Exchange (ETDEWEB)

    Dobkin, C.S.; Nolin, S.L.; Cohen, I. [NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY (United States)] [and others

    1996-08-09

    The fragile X mutation is diagnosed from the structure of the FMR1 gene in blood cell DNA. An estimated 12 to 41% of affected males are mosaics who carry both a {open_quotes}full mutation{close_quotes} allele from which there is no gene expression and a {open_quotes}premutation{close_quotes} allele which has normal gene expression. We compared the DNA in blood cells and skin fibroblasts from four mosaic fragile X males to see if there was a difference in the relative amounts of premutation and full mutation alleles within the tissues of these individuals. Two of these males showed striking differences in the ratio of premutation to full mutation in different tissues while the other two showed only slight differences. These observations conform with the widely accepted hypothesis that the fragile X CGG repeat is unstable in somatic tissue during early embryogenesis. Accordingly, the mosaicism in brain and skin, which are both ectodermal in origin, may be similar to each other but different from blood which is not ectodermal in origin. Thus, the ratio of full mutation to premutation allele in skin fibroblasts might be a better indicator of psychological impairment than the ratio in blood cells. 24 refs., 4 figs., 1 tab.

  19. Modeling the global atmospheric transport and deposition of mercury to the Great Lakes

    Directory of Open Access Journals (Sweden)

    Mark D. Cohen

    2016-07-01

    Full Text Available Abstract Mercury contamination in the Great Lakes continues to have important public health and wildlife ecotoxicology impacts, and atmospheric deposition is a significant ongoing loading pathway. The objective of this study was to estimate the amount and source-attribution for atmospheric mercury deposition to each lake, information needed to prioritize amelioration efforts. A new global, Eulerian version of the HYSPLIT-Hg model was used to simulate the 2005 global atmospheric transport and deposition of mercury to the Great Lakes. In addition to the base case, 10 alternative model configurations were used to examine sensitivity to uncertainties in atmospheric mercury chemistry and surface exchange. A novel atmospheric lifetime analysis was used to characterize fate and transport processes within the model. Model-estimated wet deposition and atmospheric concentrations of gaseous elemental mercury (Hg(0 were generally within ∼10% of measurements in the Great Lakes region. The model overestimated non-Hg(0 concentrations by a factor of 2–3, similar to other modeling studies. Potential reasons for this disagreement include model inaccuracies, differences in atmospheric Hg fractions being compared, and the measurements being biased low. Lake Erie, downwind of significant local/regional emissions sources, was estimated by the model to be the most impacted by direct anthropogenic emissions (58% of the base case total deposition, while Lake Superior, with the fewest upwind local/regional sources, was the least impacted (27%. The U.S. was the largest national contributor, followed by China, contributing 25% and 6%, respectively, on average, for the Great Lakes. The contribution of U.S. direct anthropogenic emissions to total mercury deposition varied between 46% for the base case (with a range of 24–51% over all model configurations for Lake Erie and 11% (range 6–13% for Lake Superior. These results illustrate the importance of atmospheric

  20. Genetic Correlates of Individual Differences in Sleep Behavior of Free-Living Great Tits (Parus major

    Directory of Open Access Journals (Sweden)

    Erica F. Stuber

    2016-03-01

    Full Text Available Within populations, free-living birds display considerable variation in observable sleep behaviors, reflecting dynamic interactions between individuals and their environment. Genes are expected to contribute to repeatable between-individual differences in sleep behaviors, which may be associated with individual fitness. We identified and genotyped polymorphisms in nine candidate genes for sleep, and measured five repeatable sleep behaviors in free-living great tits (Parus major, partly replicating a previous study in blue tits (Cyanistes caeruleus. Microsatellites in the CLOCK and NPAS2 clock genes exhibited an association with sleep duration relative to night length, and morning latency to exit the nest box, respectively. Furthermore, microsatellites in the NPSR1 and PCSK2 genes associated with relative sleep duration and proportion of time spent awake at night, respectively. Given the detection rate of associations in the same models run with random markers instead of candidate genes, we expected two associations to arise by chance. The detection of four associations between candidate genes and sleep, however, suggests that clock genes, a clock-related gene, or a gene involved in the melanocortin system, could play key roles in maintaining phenotypic variation in sleep behavior in avian populations. Knowledge of the genetic architecture underlying sleep behavior in the wild is important because it will enable ecologists to assess the evolution of sleep in response to selection.

  1. Genetic Correlates of Individual Differences in Sleep Behavior of Free-Living Great Tits (Parus major).

    Science.gov (United States)

    Stuber, Erica F; Baumgartner, Christine; Dingemanse, Niels J; Kempenaers, Bart; Mueller, Jakob C

    2016-01-06

    Within populations, free-living birds display considerable variation in observable sleep behaviors, reflecting dynamic interactions between individuals and their environment. Genes are expected to contribute to repeatable between-individual differences in sleep behaviors, which may be associated with individual fitness. We identified and genotyped polymorphisms in nine candidate genes for sleep, and measured five repeatable sleep behaviors in free-living great tits (Parus major), partly replicating a previous study in blue tits (Cyanistes caeruleus). Microsatellites in the CLOCK and NPAS2 clock genes exhibited an association with sleep duration relative to night length, and morning latency to exit the nest box, respectively. Furthermore, microsatellites in the NPSR1 and PCSK2 genes associated with relative sleep duration and proportion of time spent awake at night, respectively. Given the detection rate of associations in the same models run with random markers instead of candidate genes, we expected two associations to arise by chance. The detection of four associations between candidate genes and sleep, however, suggests that clock genes, a clock-related gene, or a gene involved in the melanocortin system, could play key roles in maintaining phenotypic variation in sleep behavior in avian populations. Knowledge of the genetic architecture underlying sleep behavior in the wild is important because it will enable ecologists to assess the evolution of sleep in response to selection.

  2. Melanin- and carotenoid-dependent signals of great tits (Parus major) relate differently to metal pollution.

    Science.gov (United States)

    Dauwe, Tom; Eens, Marcel

    2008-10-01

    Due to their high phenotypic plasticity, the expression of secondary sexual characteristics is particularly sensitive to stress. Here, we investigated the expression of two conspicuous visual signals in great tits (Parus major) in a metal pollution gradient. In three study sites with marked differences in metal contamination (mainly lead, cadmium, copper and zinc), we compared melanin and carotenoid colouration of great tits. While carotenoid colouration (yellow breast) was negatively related to metal pollution, the size of a melanin trait (breast stripe) was larger in the most polluted sites. Environmental pollutants not only affect the expression of conspicuous signals but may even enhance, directly or indirectly, a signal of male quality such as breast stripe. Our results also support the multiple messages hypothesis predicting that different signals highlight different aspects of geno- and phenotypic condition of the bearer.

  3. Melanin- and carotenoid-dependent signals of great tits ( Parus major) relate differently to metal pollution

    Science.gov (United States)

    Dauwe, Tom; Eens, Marcel

    2008-10-01

    Due to their high phenotypic plasticity, the expression of secondary sexual characteristics is particularly sensitive to stress. Here, we investigated the expression of two conspicuous visual signals in great tits ( Parus major) in a metal pollution gradient. In three study sites with marked differences in metal contamination (mainly lead, cadmium, copper and zinc), we compared melanin and carotenoid colouration of great tits. While carotenoid colouration (yellow breast) was negatively related to metal pollution, the size of a melanin trait (breast stripe) was larger in the most polluted sites. Environmental pollutants not only affect the expression of conspicuous signals but may even enhance, directly or indirectly, a signal of male quality such as breast stripe. Our results also support the multiple messages hypothesis predicting that different signals highlight different aspects of geno- and phenotypic condition of the bearer.

  4. Human and great ape red blood cells differ in plasmalogen levels and composition

    Directory of Open Access Journals (Sweden)

    Ely John J

    2011-06-01

    Full Text Available Abstract Background Plasmalogens are ether phospholipids required for normal mammalian developmental, physiological, and cognitive functions. They have been proposed to act as membrane antioxidants and reservoirs of polyunsaturated fatty acids as well as influence intracellular signaling and membrane dynamics. Plasmalogens are particularly enriched in cells and tissues of the human nervous, immune, and cardiovascular systems. Humans with severely reduced plasmalogen levels have reduced life spans, abnormal neurological development, skeletal dysplasia, impaired respiration, and cataracts. Plasmalogen deficiency is also found in the brain tissue of individuals with Alzheimer disease. Results In a human and great ape cohort, we measured the red blood cell (RBC levels of the most abundant types of plasmalogens. Total RBC plasmalogen levels were lower in humans than bonobos, chimpanzees, and gorillas, but higher than orangutans. There were especially pronounced cross-species differences in the levels of plasmalogens with a C16:0 moiety at the sn-1 position. Humans on Western or vegan diets had comparable total RBC plasmalogen levels, but the latter group showed moderately higher levels of plasmalogens with a C18:1 moiety at the sn-1 position. We did not find robust sex-specific differences in human or chimpanzee RBC plasmalogen levels or composition. Furthermore, human and great ape skin fibroblasts showed only modest differences in peroxisomal plasmalogen biosynthetic activity. Human and chimpanzee microarray data indicated that genes involved in plasmalogen biosynthesis show cross-species differential expression in multiple tissues. Conclusion We propose that the observed differences in human and great ape RBC plasmalogens are primarily caused by their rates of biosynthesis and/or turnover. Gene expression data raise the possibility that other human and great ape cells and tissues differ in plasmalogen levels. Based on the phenotypes of humans and

  5. Species distribution models for crop pollination: a modelling framework applied to Great Britain.

    Science.gov (United States)

    Polce, Chiara; Termansen, Mette; Aguirre-Gutiérrez, Jesus; Boatman, Nigel D; Budge, Giles E; Crowe, Andrew; Garratt, Michael P; Pietravalle, Stéphane; Potts, Simon G; Ramirez, Jorge A; Somerwill, Kate E; Biesmeijer, Jacobus C

    2013-01-01

    Insect pollination benefits over three quarters of the world's major crops. There is growing concern that observed declines in pollinators may impact on production and revenues from animal pollinated crops. Knowing the distribution of pollinators is therefore crucial for estimating their availability to pollinate crops; however, in general, we have an incomplete knowledge of where these pollinators occur. We propose a method to predict geographical patterns of pollination service to crops, novel in two elements: the use of pollinator records rather than expert knowledge to predict pollinator occurrence, and the inclusion of the managed pollinator supply. We integrated a maximum entropy species distribution model (SDM) with an existing pollination service model (PSM) to derive the availability of pollinators for crop pollination. We used nation-wide records of wild and managed pollinators (honey bees) as well as agricultural data from Great Britain. We first calibrated the SDM on a representative sample of bee and hoverfly crop pollinator species, evaluating the effects of different settings on model performance and on its capacity to identify the most important predictors. The importance of the different predictors was better resolved by SDM derived from simpler functions, with consistent results for bees and hoverflies. We then used the species distributions from the calibrated model to predict pollination service of wild and managed pollinators, using field beans as a test case. The PSM allowed us to spatially characterize the contribution of wild and managed pollinators and also identify areas potentially vulnerable to low pollination service provision, which can help direct local scale interventions. This approach can be extended to investigate geographical mismatches between crop pollination demand and the availability of pollinators, resulting from environmental change or policy scenarios.

  6. Species distribution models for crop pollination: a modelling framework applied to Great Britain.

    Directory of Open Access Journals (Sweden)

    Chiara Polce

    Full Text Available Insect pollination benefits over three quarters of the world's major crops. There is growing concern that observed declines in pollinators may impact on production and revenues from animal pollinated crops. Knowing the distribution of pollinators is therefore crucial for estimating their availability to pollinate crops; however, in general, we have an incomplete knowledge of where these pollinators occur. We propose a method to predict geographical patterns of pollination service to crops, novel in two elements: the use of pollinator records rather than expert knowledge to predict pollinator occurrence, and the inclusion of the managed pollinator supply. We integrated a maximum entropy species distribution model (SDM with an existing pollination service model (PSM to derive the availability of pollinators for crop pollination. We used nation-wide records of wild and managed pollinators (honey bees as well as agricultural data from Great Britain. We first calibrated the SDM on a representative sample of bee and hoverfly crop pollinator species, evaluating the effects of different settings on model performance and on its capacity to identify the most important predictors. The importance of the different predictors was better resolved by SDM derived from simpler functions, with consistent results for bees and hoverflies. We then used the species distributions from the calibrated model to predict pollination service of wild and managed pollinators, using field beans as a test case. The PSM allowed us to spatially characterize the contribution of wild and managed pollinators and also identify areas potentially vulnerable to low pollination service provision, which can help direct local scale interventions. This approach can be extended to investigate geographical mismatches between crop pollination demand and the availability of pollinators, resulting from environmental change or policy scenarios.

  7. Estimation of the ancestral effective population sizes of African great apes under different selection regimes.

    Science.gov (United States)

    Schrago, Carlos G

    2014-08-01

    Reliable estimates of ancestral effective population sizes are necessary to unveil the population-level phenomena that shaped the phylogeny and molecular evolution of the African great apes. Although several methods have previously been applied to infer ancestral effective population sizes, an analysis of the influence of the selective regime on the estimates of ancestral demography has not been thoroughly conducted. In this study, three independent data sets under different selective regimes were used were composed to tackle this issue. The results showed that selection had a significant impact on the estimates of ancestral effective population sizes of the African great apes. The inference of the ancestral demography of African great apes was affected by the selection regime. The effects, however, were not homogeneous along the ancestral populations of great apes. The effective population size of the ancestor of humans and chimpanzees was more impacted by the selection regime when compared to the same parameter in the ancestor of humans, chimpanzees and gorillas. Because the selection regime influenced the estimates of ancestral effective population size, it is reasonable to assume that a portion of the discrepancy found in previous studies that inferred the ancestral effective population size may be attributable to the differential action of selection on the genes sampled.

  8. Urban-rural mental health differences in Great Britain: findings from the National Morbidity Survey.

    Science.gov (United States)

    Paykel, E; Abbott, R; Jenkins, R; Brugha, T; Meltzer, H

    2003-01-01

    Studies of urban-rural differences in prevalence of non-psychotic mental disorder have not given consistent findings. Such differences have received relatively little study in Great Britain. Data from 9777 subjects in the Household Survey of the National Morbidity Survey of Great Britain were analysed for differences between urban, semi-rural, and rural areas. Psychiatric morbidity was assessed by scores on the Revised Clinical Interview Schedule (CIS-R), together with alcohol dependence, drug dependence, and receipt of treatment from general practitioners. Associations with other characteristics were examined by logistic regression. Urban subjects had higher rates than rural of CIS-R morbidity, alcohol dependence, and drug dependence, with semi-rural subjects intermediate. Urban subjects also tended to be members of more deprived social groups, with more adverse living circumstances and greater life stress--factors themselves associated with disorder. Urban-rural differences in alcohol and drug dependence were no longer significant after adjustment for these factors by logistic regression, and differences on CIS-R morbidity were considerably reduced. There were no differences in treatment. There are considerable British urban-rural differences in mental health, which may largely be attributable to more adverse urban social environments.

  9. Different Seasonal Patterns in Song System Volume in Willow Tits and Great Tits.

    Science.gov (United States)

    Longmoor, Georgia K; Lange, C Henrik; Darvell, Hannah; Walker, Lauren; Rytkönen, Seppo; Vatka, Emma; Hohtola, Esa; Orell, Markku; Smulders, Tom V

    2016-01-01

    In most species of seasonally breeding songbirds studied to date, the brain areas that control singing (i.e. the song control system, SCS) are larger during the breeding season than at other times of the year. In the family of titmice and chickadees (Paridae), one species, the blue tit (Cyanistes caeruleus), shows the typical pattern of seasonal changes, while another species, the black-capped chickadee (Poecile atricapillus), shows, at best, very reduced seasonal changes in the SCS. To test whether this pattern holds up in the two Parid lineages to which these two species belong, and to rule out that the differences in seasonal patterns observed were due to differences in geography or laboratory, we compared the seasonal patterns in two song system nuclei volumes (HVC and Area X) in willow tits (Poecile montanus), closely related to black-capped chickadees, and in great tits (Parus major), more closely related to blue tits, from the same area around Oulu, Finland. Both species had larger gonads in spring than during the rest of the year. Great tit males had a larger HVC in spring than at other times of the year, but their Area X did not change in size. Willow tits showed no seasonal change in HVC or Area X size, despite having much larger gonads in spring than the great tits. Our findings suggest that the song system of willow tits and their relatives may be involved in learning and producing nonsong social vocalizations. Since these vocalizations are used year-round, there may be a year-round demand on the song system. The great tit and blue tit HVC may change seasonally because the demand is only placed on the song system during the breeding season, since they only produce learned vocalizations during this time. We suggest that changes were not observed in Area X because its main role is in song learning, and there is evidence that great tits do not learn new songs after their first year of life. Further study is required to determine whether our hypothesis

  10. Compilation of watershed models for tributaries to the Great Lakes, United States, as of 2010, and identification of watersheds for future modeling for the Great Lakes Restoration Initiative

    Science.gov (United States)

    Coon, William F.; Murphy, Elizabeth A.; Soong, David T.; Sharpe, Jennifer B.

    2011-01-01

    As part of the Great Lakes Restoration Initiative (GLRI) during 2009–10, the U.S. Geological Survey (USGS) compiled a list of existing watershed models that had been created for tributaries within the United States that drain to the Great Lakes. Established Federal programs that are overseen by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Army Corps of Engineers (USACE) are responsible for most of the existing watershed models for specific tributaries. The NOAA Great Lakes Environmental Research Laboratory (GLERL) uses the Large Basin Runoff Model to provide data for the management of water levels in the Great Lakes by estimating United States and Canadian inflows to the Great Lakes from 121 large watersheds. GLERL also simulates streamflows in 34 U.S. watersheds by a grid-based model, the Distributed Large Basin Runoff Model. The NOAA National Weather Service uses the Sacramento Soil Moisture Accounting model to predict flows at river forecast sites. The USACE created or funded the creation of models for at least 30 tributaries to the Great Lakes to better understand sediment erosion, transport, and aggradation processes that affect Federal navigation channels and harbors. Many of the USACE hydrologic models have been coupled with hydrodynamic and sediment-transport models that simulate the processes in the stream and harbor near the mouth of the modeled tributary. Some models either have been applied or have the capability of being applied across the entire Great Lakes Basin; they are (1) the SPAtially Referenced Regressions On Watershed attributes (SPARROW) model, which was developed by the USGS; (2) the High Impact Targeting (HIT) and Digital Watershed models, which were developed by the Institute of Water Research at Michigan State University; (3) the Long-Term Hydrologic Impact Assessment (L–THIA) model, which was developed by researchers at Purdue University; and (4) the Water Erosion Prediction Project (WEPP) model, which was

  11. Ambient temperature effects on photo induced gonadal cycles and hormonal secretion patterns in Great Tits from three different breeding latitudes.

    Science.gov (United States)

    Silverin, Bengt; Wingfield, John; Stokkan, Karl-Arne; Massa, Renato; Järvinen, Antero; Andersson, Nils-Ake; Lambrechts, Marcel; Sorace, Alberto; Blomqvist, Donald

    2008-06-01

    The present study determines how populations of Great Tits (Parus major) breeding in southern, mid and northern European latitudes have adjusted their reproductive endocrinology to differences in the ambient temperature during the gonadal cycle. A study based on long-term breeding data, using the Colwell predictability model, showed that the start of the breeding season has a high predictability ( approximately 0.8-0.9) at all latitudes, and that the environmental information factor (I(e)) progressively decreased from mid Italy (I(e)>4) to northern Finland (I(e)Tits from northern Norway, southern Sweden and northern Italy to sub-maximal photo-stimulatory day lengths (13L:11D) under two different ambient temperature regimes (+4 degrees C and +20 degrees C). Changes in testicular size, plasma levels of LH and testosterone were measured. The main results were: (1) Initial testicular growth rate, as well as LH secretion, was affected by temperature in the Italian, but not in birds from the two Scandinavian populations. (2) Maximum testicular size, maximum LH and testosterone levels were maintained for a progressively shorter period of time with increasing latitude, regardless of whether the birds were kept on a low or a high ambient temperature. (3) In birds from all latitudes, the development of photorefractoriness, as indicated by testicular regression and a decrease in plasma levels of LH and testosterone, started much earlier (with the exception for LH Great Tits from northern Scandinavia) when kept on +20 degrees C than when kept on +4 degrees C. The prolonging effects of a low temperature was more pronounced in Mediterranean birds, than in birds from Scandinavia, and more pronounced in Great Tits from southern Scandinavia than in Great Tits from northern Scandinavia. Ecological implications of the results are discussed, as well as possible impact of global warming on the breeding success of European Great Tits from different breeding latitudes.

  12. A Mathematical Model of the Great Solar Eclipse of 1991.

    Science.gov (United States)

    Lamb, John Jr.

    1991-01-01

    An activity that shows how mathematics can be used to model events in the real world is described. A way to calculate the area of the sun covered by the moon during a partial eclipse is presented. A computer program that will determine the coverage percentage is also included. (KR)

  13. A Mathematical Model of the Great Solar Eclipse of 1991.

    Science.gov (United States)

    Lamb, John Jr.

    1991-01-01

    An activity that shows how mathematics can be used to model events in the real world is described. A way to calculate the area of the sun covered by the moon during a partial eclipse is presented. A computer program that will determine the coverage percentage is also included. (KR)

  14. Nanomaterials - the Next Great Challenge for Qsar Modelers

    Science.gov (United States)

    Puzyn, Tomasz; Gajewicz, Agnieszka; Leszczynska, Danuta; Leszczynski, Jerzy

    In this final chapter a new perspective for the application of QSAR in the nanosciences is discussed. The role of nanomaterials is rapidly increasing in many aspects of everyday life. This is promoting a wide range of research needs related to both the design of new materials with required properties and performing a comprehensive risk assessment of the manufactured nanoparticles. The development of nanoscience also opens new areas for QSAR modelers. We have begun this contribution with a detailed discussion on the remarkable physical-chemical properties of nanomaterials and their specific toxicities. Both these factors should be considered as potential endpoints for further nano-QSAR studies. Then, we have highlighted the status and research needs in the area of molecular descriptors applicable to nanomaterials. Finally, we have put together currently available nano-QSAR models related to the physico-chemical endpoints of nanoparticles and their activity. Although we have observed many problems (i.e., a lack of experimental data, insufficient and inadequate descriptors), we do believe that application of QSAR methodology will significantly support nanoscience in the near future. Development of reliable nano-QSARs can be considered as the next challenging task for the QSAR community.

  15. Developing Flexible, Integrated Hydrologic Modeling Systems for Multiscale Analysis in the Midwest and Great Lakes Region

    Science.gov (United States)

    Hamlet, A. F.; Chiu, C. M.; Sharma, A.; Byun, K.; Hanson, Z.

    2016-12-01

    Physically based hydrologic modeling of surface and groundwater resources that can be flexibly and efficiently applied to support water resources policy/planning/management decisions at a wide range of spatial and temporal scales are greatly needed in the Midwest, where stakeholder access to such tools is currently a fundamental barrier to basic climate change assessment and adaptation efforts, and also the co-production of useful products to support detailed decision making. Based on earlier pilot studies in the Pacific Northwest Region, we are currently assembling a suite of end-to-end tools and resources to support various kinds of water resources planning and management applications across the region. One of the key aspects of these integrated tools is that the user community can access gridded products at any point along the end-to-end chain of models, looking backwards in time about 100 years (1915-2015), and forwards in time about 85 years using CMIP5 climate model projections. The integrated model is composed of historical and projected future meteorological data based on station observations and statistical and dynamically downscaled climate model output respectively. These gridded meteorological data sets serve as forcing data for the macro-scale VIC hydrologic model implemented over the Midwest at 1/16 degree resolution. High-resolution climate model (4km WRF) output provides inputs for the analyses of urban impacts, hydrologic extremes, agricultural impacts, and impacts to the Great Lakes. Groundwater recharge estimated by the surface water model provides input data for fine-scale and macro-scale groundwater models needed for specific applications. To highlight the multi-scale use of the integrated models in support of co-production of scientific information for decision making, we briefly describe three current case studies addressing different spatial scales of analysis: 1) Effects of climate change on the water balance of the Great Lakes, 2) Future

  16. Gender and Personality Differences in Response to Social Stressors in Great Tits (Parus major).

    Science.gov (United States)

    van der Meer, Esther; van Oers, Kees

    2015-01-01

    In response to stressors, animals can increase the activity of the hypothalamic-pituitary-adrenocortical axis, resulting in elevated glucocorticoid concentrations. An increase in glucocorticoids results in an increase in heterophils and a decrease in lymphocytes, which ratio (H/L-ratio) is an indicator of stress in birds. The physiological response to a stressor can depend on individual characteristics, like dominance rank, sex and personality. Although the isolated effects of these characteristics on the response to a stressor have been well studied, little is known about the response in relation to a combination of these characteristics. In this study we investigate the relationship between social stress, dominance rank, sex and exploratory behaviour as a validated operational measure of personality in great tits (Parus major). Great tits show consistent individual differences in behaviour and physiology in response to stressors, and exploratory behaviour can be classified as fast or slow exploring. We group-housed four birds, two fast and two slow explorers, of the same sex that were previously singly housed, in an aviary and compared the H/L-ratio, lymphocyte and heterophil count before and after group housing. After experiencing the social context all birds increased their H/L-ratio and heterophil count. Females showed a stronger increase in H/L-ratio and heterophil count than males, which seemed to be related to a higher number of agonistic interactions compared to males. Dominance rank and exploration type did not affect the H/L-ratio or heterophil count. Contrary to our expectations, all birds increased their lymphocyte count. However, this increase was slower for fast than for slow explorers. Our study suggests that personality and sex related differences, but not dominance rank, are associated with changes in an individual's physiological response due to a social context.

  17. Gender and Personality Differences in Response to Social Stressors in Great Tits (Parus major.

    Directory of Open Access Journals (Sweden)

    Esther van der Meer

    Full Text Available In response to stressors, animals can increase the activity of the hypothalamic-pituitary-adrenocortical axis, resulting in elevated glucocorticoid concentrations. An increase in glucocorticoids results in an increase in heterophils and a decrease in lymphocytes, which ratio (H/L-ratio is an indicator of stress in birds. The physiological response to a stressor can depend on individual characteristics, like dominance rank, sex and personality. Although the isolated effects of these characteristics on the response to a stressor have been well studied, little is known about the response in relation to a combination of these characteristics. In this study we investigate the relationship between social stress, dominance rank, sex and exploratory behaviour as a validated operational measure of personality in great tits (Parus major. Great tits show consistent individual differences in behaviour and physiology in response to stressors, and exploratory behaviour can be classified as fast or slow exploring. We group-housed four birds, two fast and two slow explorers, of the same sex that were previously singly housed, in an aviary and compared the H/L-ratio, lymphocyte and heterophil count before and after group housing. After experiencing the social context all birds increased their H/L-ratio and heterophil count. Females showed a stronger increase in H/L-ratio and heterophil count than males, which seemed to be related to a higher number of agonistic interactions compared to males. Dominance rank and exploration type did not affect the H/L-ratio or heterophil count. Contrary to our expectations, all birds increased their lymphocyte count. However, this increase was slower for fast than for slow explorers. Our study suggests that personality and sex related differences, but not dominance rank, are associated with changes in an individual's physiological response due to a social context.

  18. Great ape origins of personality maturation and sex differences: a study of orangutans and chimpanzees.

    Science.gov (United States)

    Weiss, Alexander; King, James E

    2015-04-01

    Human personality development evinces increased emotional stability, prosocial tendencies, and responsibility. One hypothesis offered to explain this pattern is Social-Investment Theory, which posits that culturally defined social roles, including marriage and employment, are responsible for the increased maturity. Alternatively, Five-Factor Theory emphasizes the role of biological factors, such as those governing physical development, which may predate the emergence of humans. Five-Factor Theory, unlike Social-Investment Theory, predicts that all or some of the human personality developmental trends should be present in great apes, our closest evolutionary relatives. To test this prediction and to better understand the evolutionary origins of sex differences, we examined age and sex differences in the chimpanzee and orangutan personality domains Extraversion, Dominance, Neuroticism, and Agreeableness. We also examined the Activity and Gregariousness facets of Extraversion and the orangutan Intellect domain. Extraversion and Neuroticism declined across age groups in both species, in common with humans. A significant interaction indicated that Agreeableness declined in orangutans but increased in chimpanzees, as it does in humans, though this may reflect differences in how Agreeableness was defined in each species. Significant interactions indicated that male chimpanzees, unlike male orangutans, displayed higher Neuroticism scores than females and maintained higher levels of Activity and Dominance into old age than female chimpanzees, male orangutans, and female orangutans. Personality-age correlations were comparable across orangutans and chimpanzees and were similar to those reported in human studies. Sex differences were stronger in chimpanzees than in humans or orangutans. These findings support Five-Factor Theory, suggest the role of gene-culture coevolution in shaping personality development, and suggest that sex differences evolved independently in different

  19. Differences in the early cognitive development of children and great apes.

    Science.gov (United States)

    Wobber, Victoria; Herrmann, Esther; Hare, Brian; Wrangham, Richard; Tomasello, Michael

    2014-04-01

    There is very little research comparing great ape and human cognition developmentally. In the current studies we compared a cross-sectional sample of 2- to 4-year-old human children (n=48) with a large sample of chimpanzees and bonobos in the same age range (n=42, hereafter: apes) on a broad array of cognitive tasks. We then followed a group of juvenile apes (n=44) longitudinally over 3 years to track their cognitive development in greater detail. In skills of physical cognition (space, causality, quantities), children and apes performed comparably at 2 years of age, but by 4 years of age children were more advanced (whereas apes stayed at their 2-year-old performance levels). In skills of social cognition (communication, social learning, theory of mind), children out-performed apes already at 2 years, and increased this difference even more by 4 years. Patterns of development differed more between children and apes in the social domain than the physical domain, with support for these patterns present in both the cross-sectional and longitudinal ape data sets. These results indicate key differences in the pattern and pace of cognitive development between humans and other apes, particularly in the early emergence of specific social cognitive capacities in humans.

  20. Interspecies comparative genome hybridization and interspecies representational difference analysis reveal gross DNA differences between humans and great apes.

    Science.gov (United States)

    Toder, R; Xia, Y; Bausch, E

    1998-09-01

    Comparative chromosome G-/R-banding, comparative gene mapping and chromosome painting techniques have demonstrated that only few chromosomal rearrangements occurred during great ape and human evolution. Interspecies comparative genome hybridization (CGH), used here in this study, between human, gorilla and pygmy chimpanzee revealed species-specific regions in all three species. In contrast to the human, a far more complex distribution of species-specific blocks was detected with CGH in gorilla and pygmy chimpanzee. Most of these blocks coincide with already described heterochromatic regions on gorilla and chimpanzee chromosomes. Representational difference analysis (RDA) was used to subtract the complex genome of gorilla against human in order to enrich gorilla-specific DNA sequences. Gorilla-specific clones isolated with this technique revealed a 32-bp repeat unit. These clones were mapped by fluorescence in situ hybridization (FISH) to the telomeric regions of gorilla chromosomes that had been shown by interspecies CGH to contain species-specific sequences.

  1. Anticipating spring: wild populations of great tits (Parus major differ in expression of key genes for photoperiodic time measurement.

    Directory of Open Access Journals (Sweden)

    Nicole Perfito

    Full Text Available Measuring day length is critical for timing annual changes in physiology and behavior in many species. Recently, rapid changes in several photoperiodically-controlled genes following exposure to a single long day have been described. Components of this 'first day release' model have so far only been tested in highly domesticated species: quail, sheep, goats and rodents. Because artificial selection accompanying domestication acts on genes related to photoperiodicity, we must also study this phenomenon in wild organisms for it to be accepted as universal. In a songbird, the great tit (Parus major, we tested whether a these genes are involved in photoperiodic time measurement (PTM in a wild species, and b whether predictable species and population differences in expression patterns exist. Using quantitative RT-PCR, we compared gene expression after a single long day in male great tits from Sweden (57°42'N with that from a German (47°43'N population. Hypothalamic gene expression key for PTM changed only in the northern population, and occurred earlier after dawn during the single long day than demonstrated in quail; however, gonadotropins (secretion and synthesis were stimulated in both populations, albeit with different timing. Our data are the first to show acute changes in gene expression in response to photostimulation in any wild species not selected for study of photoperiodism. The pronounced differences in gene expression in response to a single long day between two populations raise exciting new questions about potential environmental selection on photoperiodic cue sensitivity.

  2. Competition effects from cheatgrass (Bromus tectorum) differs among perennial grasses of the Great Basin

    Science.gov (United States)

    Competition from the exotic annual grass, cheatgrass (Bromus tectorum), threatens millions of hectares of native plant communities throughout the Great Basin. The Nature Conservancy has identified the Great Basin as the third most endangered ecosystem in the United States. Not only has increased fue...

  3. Modelling psychological responses to the Great East Japan earthquake and nuclear incident.

    Directory of Open Access Journals (Sweden)

    Robin Goodwin

    Full Text Available The Great East Japan (Tōhoku/Kanto earthquake of March 2011 was followed by a major tsunami and nuclear incident. Several previous studies have suggested a number of psychological responses to such disasters. However, few previous studies have modelled individual differences in the risk perceptions of major events, or the implications of these perceptions for relevant behaviours. We conducted a survey specifically examining responses to the Great Japan earthquake and nuclear incident, with data collected 11-13 weeks following these events. 844 young respondents completed a questionnaire in three regions of Japan; Miyagi (close to the earthquake and leaking nuclear plants, Tokyo/Chiba (approximately 220 km from the nuclear plants, and Western Japan (Yamaguchi and Nagasaki, some 1000 km from the plants. Results indicated significant regional differences in risk perception, with greater concern over earthquake risks in Tokyo than in Miyagi or Western Japan. Structural equation analyses showed that shared normative concerns about earthquake and nuclear risks, conservation values, lack of trust in governmental advice about the nuclear hazard, and poor personal control over the nuclear incident were positively correlated with perceived earthquake and nuclear risks. These risk perceptions further predicted specific outcomes (e.g. modifying homes, avoiding going outside, contemplating leaving Japan. The strength and significance of these pathways varied by region. Mental health and practical implications of these findings are discussed in the light of the continuing uncertainties in Japan following the March 2011 events.

  4. Modelling psychological responses to the Great East Japan earthquake and nuclear incident.

    Science.gov (United States)

    Goodwin, Robin; Takahashi, Masahito; Sun, Shaojing; Gaines, Stanley O

    2012-01-01

    The Great East Japan (Tōhoku/Kanto) earthquake of March 2011 was followed by a major tsunami and nuclear incident. Several previous studies have suggested a number of psychological responses to such disasters. However, few previous studies have modelled individual differences in the risk perceptions of major events, or the implications of these perceptions for relevant behaviours. We conducted a survey specifically examining responses to the Great Japan earthquake and nuclear incident, with data collected 11-13 weeks following these events. 844 young respondents completed a questionnaire in three regions of Japan; Miyagi (close to the earthquake and leaking nuclear plants), Tokyo/Chiba (approximately 220 km from the nuclear plants), and Western Japan (Yamaguchi and Nagasaki, some 1000 km from the plants). Results indicated significant regional differences in risk perception, with greater concern over earthquake risks in Tokyo than in Miyagi or Western Japan. Structural equation analyses showed that shared normative concerns about earthquake and nuclear risks, conservation values, lack of trust in governmental advice about the nuclear hazard, and poor personal control over the nuclear incident were positively correlated with perceived earthquake and nuclear risks. These risk perceptions further predicted specific outcomes (e.g. modifying homes, avoiding going outside, contemplating leaving Japan). The strength and significance of these pathways varied by region. Mental health and practical implications of these findings are discussed in the light of the continuing uncertainties in Japan following the March 2011 events.

  5. Consistent individual differences in the social phenotypes of wild great tits, Parus major.

    Science.gov (United States)

    Aplin, L M; Firth, J A; Farine, D R; Voelkl, B; Crates, R A; Culina, A; Garroway, C J; Hinde, C A; Kidd, L R; Psorakis, I; Milligan, N D; Radersma, R; Verhelst, B L; Sheldon, B C

    2015-10-01

    Despite growing interest in animal social networks, surprisingly little is known about whether individuals are consistent in their social network characteristics. Networks are rarely repeatedly sampled; yet an assumption of individual consistency in social behaviour is often made when drawing conclusions about the consequences of social processes and structure. A characterization of such social phenotypes is therefore vital to understanding the significance of social network structure for individual fitness outcomes, and for understanding the evolution and ecology of individual variation in social behaviour more broadly. Here, we measured foraging associations over three winters in a large PIT-tagged population of great tits, and used a range of social network metrics to quantify individual variation in social behaviour. We then examined repeatability in social behaviour over both short (week to week) and long (year to year) timescales, and investigated variation in repeatability across age and sex classes. Social behaviours were significantly repeatable across all timescales, with the highest repeatability observed in group size choice and unweighted degree, a measure of gregariousness. By conducting randomizations to control for the spatial and temporal distribution of individuals, we further show that differences in social phenotypes were not solely explained by within-population variation in local densities, but also reflected fine-scale variation in social decision making. Our results provide rare evidence of stable social phenotypes in a wild population of animals. Such stable social phenotypes can be targets of selection and may have important fitness consequences, both for individuals and for their social-foraging associates.

  6. Effects of different disturbance types on butterflyfish communities of Australia's Great Barrier Reef

    Science.gov (United States)

    Emslie, M. J.; Pratchett, M. S.; Cheal, A. J.

    2011-06-01

    The effects of disturbances on coral reef fishes have been extensively documented but most studies have relied on opportunistic sampling following single events. Few studies have the spatial and temporal extent to directly compare the effects of multiple disturbances over a large geographic scale. Here, benthic communities and butterflyfishes on 47 reefs of the Great Barrier Reef were surveyed annually to examine their responses to physical disturbances (cyclones and storms) and/or biological disturbances (bleaching, outbreaks of crown-of-thorns starfish and white syndrome disease). The effects on benthic and butterflyfish communities varied among reefs depending on the structure and geographical setting of each community, on the size and type of disturbance, and on the disturbance history of that reef. There was considerable variability in the response of butterflyfishes to different disturbances: physical disturbances (occurring with or without biological disturbances) produced substantial declines in abundance, whilst biological disturbances occurring on their own did not. Butterflyfishes with the narrowest feeding preferences, such as obligate corallivores, were always the species most affected. The response of generalist feeders varied with the extent of damage. Wholesale changes to the butterflyfish community were only recorded where structural complexity of reefs was drastically reduced. The observed effects of disturbances on butterflyfishes coupled with predictions of increased frequency and intensity of disturbances sound a dire warning for the future of butterflyfish communities in particular and reef fish communities in general.

  7. Bode Analysis and Modeling of Water Level Change in the Great Lakes

    Science.gov (United States)

    Tebbens, S. F.; Smigelski, J. R.; Barton, C. C.

    2009-12-01

    Power Spectral Density calculated from a fast Fourier transform expresses a time series in terms of power in the corresponding frequency domain. The power-scaling exponent ( β ) is determined by fitting a power function to a log-log plot of frequency ( f ) or period ( 1/f ) versus power in the frequency domain. Anthropogenic and natural fluctuations including precipitation, runoff, snowmelt, water retention time, evaporation, and outflow all contribute to changes in water levels recorded in the Great Lakes. In this study, NOAA verified hourly water level data ranging from 20 to 30 years in duration for five stations in Lake Michigan and four stations in Lake Superior were analyzed. Water level time series in the Great Lakes are found to exhibit power law scaling and are thus self-affine over four distinct period ranges, each with a different beta value. With this information, a model of the original time series may be generated using an approach which draws from concepts in control theory and feedback systems. Bode Analysis can be applied in the frequency domain to explain variations in the scaling behavior ( β ) of water level data by examining the patterns of change in amplitude and phase across frequencies. A Bode magnitude plot of the system is created from the data of power versus frequency converting the amplitude to 20log dB magnitude. A transfer function representing the output of the system divided by the input is then derived based on the data using Laplace transforms and solved for magnitude and phase. Bode analysis results in a series of two transfer function equations, one for magnitude and one for phase, for each distinct beta value over the specified period range. The type of differential equation controls the slope ( β ) while the constant (k) in the differential equation controls the position (period) of transitions in scaling behavior (i.e., corner frequencies or inflection points) and are characteristics of the system. Combining the transfer

  8. Modifed Great Basin Extent (Buffered)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Two different great basin perimeter files were intersected and dissolved using ArcGIS 10.2.2 to create the outer perimeter of the great basin for use modeling...

  9. Individual Differences in Equity Models

    Science.gov (United States)

    Hofmans, Joeri

    2012-01-01

    In the present paper, we (1) study whether people differ in the equity models they use, and (2) test whether individual differences in equity models relate to individual differences in equity sensitivity. To achieve this goal, an Information Integration experiment was performed in which participants were given information on the performance of two…

  10. Modeling Potential Climatic Treeline of Great Basin Bristlecone Pine in the Snake Mountain Range, Nevada, USA

    Science.gov (United States)

    Bruening, J. M.; Tran, T. J.; Bunn, A. G.; Salzer, M. W.; Weiss, S. B.

    2015-12-01

    Great Basin bristlecone pine (Pinus longaeva) is a valuable paleoclimate resource due to the climatic sensitivity of its annually-resolved rings. Recent work has shown that low growing season temperatures limit tree growth at the upper treeline ecotone. The presence of precisely dated remnant wood above modern treeline shows that this ecotone shifts at centennial timescales; in some areas during the Holocene climatic optimum treeline was 100 m higher than at present. A recent model from Paulsen and Körner (2014, doi:10.1007/s00035-014-0124-0) predicts global potential treeline position as a function of climate. The model develops three parameters necessary to sustain a temperature-limited treeline; a growing season longer than 94 days, defined by all days with a mean temperature >0.9 °C, and a mean temperature of 6.4 °C across the entire growing season. While maintaining impressive global accuracy in treeline prediction, these parameters are not specific to the semi-arid Great Basin bristlecone pine treelines in Nevada. In this study, we used 49 temperature sensors arrayed across approximately one square kilometer of complex terrain at treeline on Mount Washington to model temperatures using topographic indices. Results show relatively accurate prediction throughout the growing season (e.g., July average daily temperatures were modeled with an R2 of 0.80 and an RMSE of 0.29 °C). The modeled temperatures enabled calibration of a regional treeline model, yielding different parameters needed to predict potential treeline than the global model. Preliminary results indicate that modern Bristlecone pine treeline on and around Mount Washington occurs in areas with a longer growing season length (~160 days defined by all days with a mean temperature >0.9 °C) and a warmer seasonal mean temperature (~9 °C) than the global average. This work will provide a baseline data set on treeline position in the Snake Range derived only from parameters physiologically relevant to

  11. Comparing different dynamic stall models

    Energy Technology Data Exchange (ETDEWEB)

    Holierhoek, J.G. [Unit Wind Energy, Energy research Centre of the Netherlands, ZG, Petten (Netherlands); De Vaal, J.B.; Van Zuijlen, A.H.; Bijl, H. [Aerospace Engineering, Delft University of Technology, Delft (Netherlands)

    2012-07-16

    The dynamic stall phenomenon and its importance for load calculations and aeroelastic simulations is well known. Different models exist to model the effect of dynamic stall; however, a systematic comparison is still lacking. To investigate if one is performing better than another, three models are used to simulate the Ohio State University measurements and a set of data from the National Aeronautics and Space Administration Ames experimental study of dynamic stall and compare results. These measurements were at conditions and for aerofoils that are typical for wind turbines, and the results are publicly available. The three selected dynamic stall models are the ONERA model, the Beddoes-Leishman model and the Snel model. The simulations show that there are still significant differences between measurements and models and that none of the models is significantly better in all cases than the other models. Especially in the deep stall regime, the accuracy of each of the dynamic stall models is limited.

  12. Differences in the Nonverbal Requests of Great Apes and Human Infants

    NARCIS (Netherlands)

    van der Goot, M. H.; Tomasello, Michael; Liszkowski, Ulf

    2014-01-01

    This study investigated how great apes and human infants use imperative pointing to request objects. In a series of three experiments (infants, N = 44; apes, N = 12), subjects were given the opportunity to either point to a desired object from a distance or else to approach closer and request it pro

  13. Data requirements of GREAT-ER: Modelling and validation using LAS in four UK catchments

    Energy Technology Data Exchange (ETDEWEB)

    Price, Oliver R., E-mail: oliver.price@unilever.co [Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ (United Kingdom); Munday, Dawn K. [Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ (United Kingdom); Whelan, Mick J. [Department of Natural Resources, School of Applied Sciences, Cranfield University, College Road, Cranfield, Bedfordshire MK43 0AL (United Kingdom); Holt, Martin S. [ECETOC, Ave van Nieuwenhuyse 4, Box 6, B-1160 Brussels (Belgium); Fox, Katharine K. [85 Park Road West, Birkenhead, Merseyside CH43 8SQ (United Kingdom); Morris, Gerard [Environment Agency, Phoenix House, Global Avenue, Leeds LS11 8PG (United Kingdom); Young, Andrew R. [Wallingford HydroSolutions Ltd, Maclean building, Crowmarsh Gifford, Wallingford, Oxon OX10 8BB (United Kingdom)

    2009-10-15

    Higher-tier environmental risk assessments on 'down-the-drain' chemicals in river networks can be conducted using models such as GREAT-ER (Geography-referenced Regional Exposure Assessment Tool for European Rivers). It is important these models are evaluated and their sensitivities to input variables understood. This study had two primary objectives: evaluate GREAT-ER model performance, comparing simulated modelled predictions for LAS (linear alkylbenzene sulphonate) with measured concentrations, for four rivers in the UK, and investigate model sensitivity to input variables. We demonstrate that the GREAT-ER model is very sensitive to variability in river discharges. However it is insensitive to the form of distributions used to describe chemical usage and removal rate in sewage treatment plants (STPs). It is concluded that more effort should be directed towards improving empirical estimates of effluent load and reducing uncertainty associated with usage and removal rates in STPs. Simulations could be improved by incorporating the effect of river depth on dissipation rates. - Validation of GREAT-ER.

  14. Forecasting credit card portfolio losses in the Great Recession: a study in model risk

    OpenAIRE

    Canals-Cerda, Jose J.; Kerr, Sougata

    2014-01-01

    Credit card portfolios represent a significant component of the balance sheets of the largest US banks. The charge‐off rate in this asset class increased drastically during the Great Recession. The recent economic downturn offers a unique opportunity to analyze the performance of credit risk models applied to credit card portfolios under conditions of economic stress. Specifically, we evaluate three potential sources of model risk: model specification, sample selection, and stress scenario se...

  15. Identification of differences in human and great ape phytanic acid metabolism that could influence gene expression profiles and physiological functions

    Directory of Open Access Journals (Sweden)

    Siegmund Kimberly D

    2010-10-01

    Full Text Available Abstract Background It has been proposed that anatomical differences in human and great ape guts arose in response to species-specific diets and energy demands. To investigate functional genomic consequences of these differences, we compared their physiological levels of phytanic acid, a branched chain fatty acid that can be derived from the microbial degradation of chlorophyll in ruminant guts. Humans who accumulate large stores of phytanic acid commonly develop cerebellar ataxia, peripheral polyneuropathy, and retinitis pigmentosa in addition to other medical conditions. Furthermore, phytanic acid is an activator of the PPAR-alpha transcription factor that influences the expression of genes relevant to lipid metabolism. Results Despite their trace dietary phytanic acid intake, all great ape species had elevated red blood cell (RBC phytanic acid levels relative to humans on diverse diets. Unlike humans, chimpanzees showed sexual dimorphism in RBC phytanic acid levels, which were higher in males relative to females. Cultured skin fibroblasts from all species had a robust capacity to degrade phytanic acid. We provide indirect evidence that great apes, in contrast to humans, derive significant amounts of phytanic acid from the hindgut fermentation of plant materials. This would represent a novel reduction of metabolic activity in humans relative to the great apes. Conclusion We identified differences in the physiological levels of phytanic acid in humans and great apes and propose this is causally related to their gut anatomies and microbiomes. Phytanic acid levels could contribute to cross-species and sex-specific differences in human and great ape transcriptomes, especially those related to lipid metabolism. Based on the medical conditions caused by phytanic acid accumulation, we suggest that differences in phytanic acid metabolism could influence the functions of human and great ape nervous, cardiovascular, and skeletal systems.

  16. Great apes can defer exchange: a replication with different results suggesting future oriented behavior.

    Science.gov (United States)

    Osvath, Mathias; Persson, Tomas

    2013-01-01

    The topic of cognitive foresight in non-human animals has received considerable attention in the last decade. The main questions concern whether the animals can prepare for upcoming situations which are, to various degrees, contextually or sensorially detached from the situation in which the preparations are made. Studies on great apes have focused on tool-related tasks, e.g., the ability to select a tool which is functional only in the future. Dufour and Sterck (2008), however, investigated whether chimpanzees were also able to prepare for a future exchange with a human: an object exchanged for a food item. The study included extensive training on the exchangeable item, which is traditionally not compatible with methods for studying planning abilities, as associative learning cannot be precluded. Nevertheless, despite this training, the chimpanzees could not solve the deferred exchange task. Given that great apes can plan for tool use, these results are puzzling. In addition, claims that great ape foresight is highly limited has been based on this study (Suddendorf and Corballis, 2010). Here we partly replicated Dufour and Sterck's study to discern whether temporally deferred and spatially displaced exchange tasks are beyond the capabilities of great apes. In addition to chimpanzees we tested orangutans. One condition followed the one used by Dufour and Sterck, in which the exchange items, functional only in the future, are placed at a location that freely allows for selections by the subjects. In order to test the possibility that the choice set-up could explain the negative results in Dufour and Sterck's study, our second condition followed a method used in the planning study by Osvath and Osvath (2008), where the subjects make a forced one-item-choice from a tray. We found that it is within the capabilities of chimpanzees and orangutans to perform deferred exchange in both conditions.

  17. Great apes can defer exchange: a replication with different results suggesting future oriented behaviour

    Directory of Open Access Journals (Sweden)

    Mathias eOsvath

    2013-10-01

    Full Text Available The topic of cognitive foresight in non-human animals has received considerable attention in the last decade. The main questions concern whether the animals can prepare for upcoming situations which are, to various degrees, contextually or sensorially detached from the situation in which the preparations are made. Studies on great apes have focused on tool-related tasks, e.g. the ability to select a tool which is functional only in the future. Dufour and Sterck (2008, however, investigated whether chimpanzees were also able to prepare for a future exchange with a human: an object exchanged for a food item. The study included extensive training on the exchangeable item, which is traditionally not compatible with methods for studying planning abilities, as associative learning cannot be precluded. Nevertheless, despite this training, the chimpanzees could not solve the deferred exchange task. Given that great apes can plan for tool use, these results are puzzling. In addition, claims that great ape foresight is highly limited has been based on this study (Suddendorf and Corballis, 2010. Here we partly replicated Dufour and Sterck’s study to discern whether temporally deferred and spatially displaced exchange tasks are beyond the capabilities of great apes. In addition to chimpanzees we tested orangutans. One condition followed the one used by Dufour and Sterck, in which the exchange items, functional only in the future, are placed at a location that freely allows for selections by the subjects. In order to test the possibility that the choice set-up could explain the negative results in Dufour and Sterck’s study, our second condition followed a method used in the planning study by Osvath and Osvath (2008, where the subjects make a forced one-item-choice from a tray. We found that it is within the capabilities of chimpanzees and orangutans to perform deferred exchange in both conditions.

  18. Difference on cone size preferences between two coniferous species by Great Spotted Woodpecker (Dendrocopos major).

    Science.gov (United States)

    Dylewski, Łukasz; Yosef, Reuven; Myczko, Łukasz

    2017-01-01

    The number of species that specialize in pre-dispersal seed predation is relatively small. Examples of specialized pre-dispersal seed predators adapted to feeding on closed cones include vertebrate species like Crossbills, Squirrels, Nutcrackers and Woodpeckers. Seed predation selects against certain phenotypic features of cones and favors another phenotypic features. In this study, we document preferences of the Great Spotted Woodpecker (Dendrocopos major) for specific traits in the cones of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris). We found that the Great Spotted Woodpecker prefers to feed on medium sized Norway spruce cones. The results suggest a disruptive selection that favors the extreme cone lengths in Norway spruce. In Scots pine, the woodpeckers avoided cones with large apophyses. Further, the selectivity for the specific characteristics of the cones is probably related to the configuration of the anvil, a place at which woodpeckers extract seeds from the cones. We think that the Great Spotted Woodpecker preferences in relation to the morphological characteristics of cones are a key to the design of the anvil in order to maximize the use of it as a tool for processing cones of both the Norway spruce and the Scots pine.

  19. Using the MESH modelling system for hydrological ensemble forecasting of the Laurentian Great Lakes at the regional scale

    Directory of Open Access Journals (Sweden)

    A. Pietroniro

    2006-08-01

    Full Text Available Environment Canada has been developing a community environmental modelling system (Modélisation Environmentale Communautaire – MEC, which is designed to facilitate coupling between models focusing on different components of the earth system. The ultimate objective of MEC is to use the coupled models to produce operational forecasts. MESH (MEC – Surface and Hydrology, a configuration of MEC currently under development, is specialized for coupled land-surface and hydrological models. To determine the specific requirements for MESH, its different components were implemented on the Laurentian Great Lakes watershed, situated on the Canada–U.S. border. This experiment showed that MESH can help us better understand the behaviour of different land-surface models, test different schemes for producing ensemble streamflow forecasts, and provide a means of sharing the data, the models and the results with collaborators and end-users. This modelling framework is at the heart of a testbed proposal for the Hydrologic Ensemble Prediction Experiment (HEPEX which should allow us to make use of the North American Ensemble Forecasting System (NAEFS to improve streamflow forecasts of the Great Lakes tributaries, and demonstrate how MESH can contribute to a Community Hydrologic Prediction System (CHPS.

  20. Evaluation of a single column model at the Southern Great Plains climate research facility

    Science.gov (United States)

    Kennedy, Aaron D.

    Despite recent advancements in global climate modeling, models produce a large range of climate sensitivities for the Earth. This range of sensitivities results in part from uncertainties in modeling clouds. To understand and to improve cloud parameterizations in Global Climate Models (GCMs), simulations should be evaluated using observations of clouds. Detailed studies can be conducted at Atmospheric Radiation Measurements (ARM) sites which provide adequate observations and forcing for Single Column Model (SCM) studies. Unfortunately, forcing for SCMs is sparse and not available for many locations or times. This study had two main goals: (1) evaluate clouds from the GISS Model E AR5 SCM at the ARM Southern Great Plains site and (2) determine whether reanalysis-based forcing was feasible at this location. To accomplish these goals, multiple model runs were conducted from 1999--2008 using forcing provided by ARM and forcing developed from the North American Regional Reanalysis (NARR). To better understand cloud biases and differences in the forcings, atmospheric states were classified using Self Organizing Maps (SOMs). Although model simulations had many similarities with the observations, there were several noticeable biases. Deep clouds had a negative bias year-round and this was attributed to clouds being too thin during frontal systems and a lack of convection during the spring and summer. These results were consistent regardless of the forcing used. During August, SCM simulations had a positive bias for low clouds. This bias varied with the forcing suggesting that part of the problem was tied to errors in the forcing. NARR forcing had many favorable characteristics when compared to ARM observations and forcing. In particular, temperature and wind information were more accurate than ARM when compared to balloon soundings. During the cool season, NARR forcing produced results similar to ARM with reasonable precipitation and a similar cloud field. Although NARR

  1. Modelling of atmospheric transport and deposition of toxaphene into the great lakes ecosystem

    Science.gov (United States)

    Voldner, E. C.; Schroeder, W. H.

    Toxaphene, not extensively used in the Great Lakes basin, has been found in fish, lake water, ambient air and precipitation in this region. It has been suggested that the atmosphere constitutes a primary transport route of toxaphene to the Great Lakes from the major source regions in the southern U.S. Environmental measurements are too few to estimate the input of toxaphene to the Great Lakes basins. The ASTRAP model, used in acid rain research, was modified for simulation of the atmospheric pathway of toxaphene. Based on emission inventories, derived from use patterns in North America for 1976 and 1980, air concentration and deposition of toxaphene to the Great Lakes were estimated. The results confirm that the atmosphere is a major transport route of toxaphene to the Great Lakes region. They also show that toxaphene can be transported to the North Atlantic. Total deposition to the Lakes in 1980 was 3-10 t and annual average air concentrations about 0.5ngm -3. Although the information on physical/chemical properties and emissions is incomplete and air quality and precipitation chemistry measurements of toxaphene are few and uncertain, model predictions show good agreement with the measurements.

  2. Conceptual model of the Great Basin carbonate and alluvial aquifer system

    Science.gov (United States)

    Heilweil, Victor M.; Brooks, Lynette E.

    2011-01-01

    A conceptual model of the Great Basin carbonate and alluvial aquifer system (GBCAAS) was developed by the U.S. Geological Survey (USGS) for a regional assessment of groundwater availability as part of a national water census. The study area is an expansion of a previous USGS Regional Aquifer Systems Analysis (RASA) study conducted during the 1980s and 1990s of the carbonate-rock province of the Great Basin. The geographic extent of the study area is 110,000 mi2, predominantly in eastern Nevada and western Utah, and includes 165 hydrographic areas (HAs) and 17 regional groundwater flow systems.

  3. Spatially-explicit modelling of nutrient loading to the landscape in the Great Lakes Basin

    Science.gov (United States)

    Hamlin, Q. F.; Kendall, A. D.; Martin, S. L.; Whitenack, H. D.; Hyndman, D. W.

    2016-12-01

    Loading of nitrogen and phosphorus to the landscape has resulted in dangerous algal blooms, contaminated drinking water, and decreased biodiversity. Here, we developed a GIS model to estimate spatially explicit nutrient loading across the Great Lakes Basin. The model expands on previous work in the lower peninsula of Michigan by Luscz et al. (2015). Inputs to the model include point source loads to streams along with five non-point source landscape loads: atmospheric deposition, chemical agricultural fertilizer, chemical non-agricultural fertilizer, manure application, and septic tanks. Scaling up from Michigan to the eight U.S. states and two Canadian provinces in the Great Lakes Basin provided unique challenges. In the case of the septic tank inputs, we compiled a multistate database of drinking water wells for use in an automated Python script to delineate wastewater treatment plant service areas and to estimate placement of septic tanks appropriately within the landscape. Using a model with individual nutrient inputs showed that even within a single land use class, there is high variability in loading rates. This variability suggests that simply prescribing loading estimates based on land use class is insufficient. Modelling high resolution and source specific landscape nutrient loading will be valuable to target strategies to decrease excessive anthropogenic nutrient loading in the Great Lakes Basin.

  4. Fine-scale modeling of bristlecone pine treeline position in the Great Basin, USA

    Science.gov (United States)

    Bruening, Jamis M.; Tran, Tyler J.; Bunn, Andrew G.; Weiss, Stuart B.; Salzer, Matthew W.

    2017-01-01

    Great Basin bristlecone pine (Pinus longaeva) and foxtail pine (Pinus balfouriana) are valuable paleoclimate resources due to their longevity and climatic sensitivity of their annually-resolved rings. Treeline research has shown that growing season temperatures limit tree growth at and just below the upper treeline. In the Great Basin, the presence of precisely dated remnant wood above modern treeline shows that the treeline ecotone shifts at centennial timescales tracking long-term changes in climate; in some areas during the Holocene climatic optimum treeline was 100 meters higher than at present. Regional treeline position models built exclusively from climate data may identify characteristics specific to Great Basin treelines and inform future physiological studies, providing a measure of climate sensitivity specific to bristlecone and foxtail pine treelines. This study implements a topoclimatic analysis—using topographic variables to explain patterns in surface temperatures across diverse mountainous terrain—to model the treeline position of three semi-arid bristlecone and/or foxtail pine treelines in the Great Basin as a function of growing season length and mean temperature calculated from in situ measurements. Results indicate: (1) the treeline sites used in this study are similar to other treelines globally, and require a growing season length of between 147-153 days and average temperature ranging from 5.5°C-7.2°C, (2) site-specific treeline position models may be improved through topoclimatic analysis and (3) treeline position in the Great Basin is likely out of equilibrium with the current climate, indicating a possible future upslope shift in treeline position.

  5. Downscaling Soil Moisture in the Southern Great Plains Through a Calibrated Multifractal Model for Land Surface Modeling Applications

    Science.gov (United States)

    Mascaro, Giuseppe; Vivoni, Enrique R.; Deidda, Roberto

    2010-01-01

    Accounting for small-scale spatial heterogeneity of soil moisture (theta) is required to enhance the predictive skill of land surface models. In this paper, we present the results of the development, calibration, and performance evaluation of a downscaling model based on multifractal theory using aircraft!based (800 m) theta estimates collected during the southern Great Plains experiment in 1997 (SGP97).We first demonstrate the presence of scale invariance and multifractality in theta fields of nine square domains of size 25.6 x 25.6 sq km, approximately a satellite footprint. Then, we estimate the downscaling model parameters and evaluate the model performance using a set of different calibration approaches. Results reveal that small-scale theta distributions are adequately reproduced across the entire region when coarse predictors include a dynamic component (i.e., the spatial mean soil moisture ) and a stationary contribution accounting for static features (i.e., topography, soil texture, vegetation). For wet conditions, we found similar multifractal properties of soil moisture across all domains, which we ascribe to the signature of rainfall spatial variability. For drier states, the theta fields in the northern domains are more intermittent than in southern domains, likely because of differences in the distribution of vegetation coverage. Through our analyses, we propose a regional downscaling relation for coarse, satellite-based soil moisture estimates, based on ancillary information (static and dynamic landscape features), which can be used in the study area to characterize statistical properties of small-scale theta distribution required by land surface models and data assimilation systems.

  6. Comparison of land-use regression models between Great Britain and the Netherlands.

    NARCIS (Netherlands)

    Vienneau, D.; de Hoogh, K.; Beelen, R.M.J.; Fischer, P.; Hoek, G.; Briggs, D.

    2010-01-01

    Land-use regression models have increasingly been applied for air pollution mapping at typically the city level. Though models generally predict spatial variability well, the structure of models differs widely between studies. The observed differences in the models may be due to artefacts of data an

  7. A study on the complexity of a business cycle model with great excitements in non-resonant condition

    Energy Technology Data Exchange (ETDEWEB)

    Ma Junhai [School of Management, Tianjin University, Tianjin 300072 (China); Tianjin University of Finance and Economics, Tianjin 300222 (China)], E-mail: mjhtju@yahoo.com.cn; Cui Yaqiang; Liulixia [School of Management, Tianjin University, Tianjin 300072 (China)

    2009-03-15

    Based on the researches of Szydlowski and Krawiec, we studied the inherent complexity of a chaotic business cycle with great excitements in non-resonant condition. First, we got the first-order and second-order approximate solutions of the system by using multiple scale method. Then deduced the formulation reflecting the complex relations between vibration, phase, bifurcation parameter {mu} and excite frequency {omega} of first-order solution. As the great excitement F varied, the global changes of the system solutions were analyzed. We also explored the different paths leading the systems with different parameter combinations into catastrophe region, fuzzy region or chaos region. Finally, we discussed the evolution trends of business cycle models under the above-mentioned conditions. Hence, this paper has some theoretical and practical significance.

  8. Modeling stakeholder-defined climate risk on the Upper Great Lakes

    Science.gov (United States)

    Moody, Paul; Brown, Casey

    2012-10-01

    Climate change is believed to pose potential risks to the stakeholders of the Great Lakes due to changes in lake levels. This paper presents a model of stakeholder-defined risk as a function of climate change. It describes the development of a statistical model that links water resources system performance and climate changes developed for the Great Lakes of North America. The function is used in a process that links bottom-up water system vulnerability assessment to top-down climate change information. Vulnerabilities are defined based on input from stakeholders and resource experts and are used to determine system performance thresholds. These thresholds are used to measure performance over a wide range of climate changes mined from a large (55,590 year) stochastic data set. The performance and climate conditions are used to create a climate response function, a statistical model to predict lake performance based on climate statistics. This function facilitates exploration and analysis of performance over a wide range of climate conditions. It can also be used to estimate risk associated with change in climate mean and variability resulting from climate change. Problematic changes in climate can be identified and the probability of those conditions estimated using climate projections or other sources of climate information. The function can also be used to evaluate the robustness of a regulation plan and to compare performance of alternate plans. This paper demonstrates the utility of the climate response function as applied within the context of the International Upper Great Lakes Study.

  9. Using simulation modeling to estimate effects of climate change on Great Plains woodlands

    Energy Technology Data Exchange (ETDEWEB)

    Guertin, D.S.; Easterling, W.E.; Brandle, J.R. [Univ. of Nebraska, Lincoln, NE (United States)

    1995-06-01

    The potential effects of climate change on biological diversity are uncertain and are likely to vary among systems. In intensively cultivated regions of the Great Plains, small unmanaged corridors of land between agricultural fields are particularly important in maintaining biological diversity, but possible responses of these corridors to climate change are mainly unknown. Many corridors are wooded, either as natural riparian forests or as planted shelterbelts. We used an individual-based community dynamics model to predict responses of linear Great Plains forests to climate change. The model estimates changes in forest communities as a result of responses of individual trees to environmental conditions. It is based on existing forest dynamics models, but incorporates features that are unique to landscapes with spatially segregated linear forest patches. In particular, we consider (1) the dispersal of seeds among patches as a function of distance between patches and species- specific probabilities of dispersal; and (2) species-specific responses to seasonal flooding and fluctuations in water table along riparian corridors. Using a nested regional climate model as a driver, we modeled changes in forest composition and structure resulting from climate changes in a doubled-CO{sub 2} atmosphere. The changes predicted by the model may have important implications for both floral and faunal diversity.

  10. Gender Differences in Mental Health Outcomes before, during, and after the Great Recession.

    Directory of Open Access Journals (Sweden)

    Rada K Dagher

    Full Text Available We examined gender differences in mental health outcomes during and post-recession versus pre-recession. We utilized 2005-2006, 2008-2009, and 2010-2011 data from the Medical Expenditure Panel Survey. Females had lower odds of depression diagnoses during and post-recession and better mental health during the recession, but higher odds of anxiety diagnoses post-recession. Males had lower odds of depression diagnoses and better mental health during and post-recession and lower Kessler 6 scores post-recession. We conducted stratified analyses, which confirmed that the aforementioned findings were consistent across the four different regions of the U.S., by employment status, income and health care utilization. Importantly, we found that the higher odds of anxiety diagnoses among females after the recession were mainly prominent among specific subgroups of females: those who lived in the Northeast or the Midwest, the unemployed, and those with low household income. Gender differences in mental health in association with the economic recession highlight the importance of policymakers taking these differences into consideration when designing economic and social policies to address economic downturns. Future research should examine the reasons behind the decreased depression diagnoses among both genders, and whether they signify decreased mental healthcare utilization or increased social support and more time for exercise and leisure activities.

  11. Different from Us: Teaching About the Rich After Occupy and the Great Recession

    Directory of Open Access Journals (Sweden)

    Richard Ohmann

    2015-02-01

    Full Text Available In a famous imaginary exchange, F. Scott Fitzgerald said, "The rich are different from us."  Ernest Hemingway replied, "Yes, they have more money."   Most critics have thought the epigram attributed to Fitzgerald more perceptive about class in the United States than the one attributed to Hemingway.  But if we're looking for a wry take on how class has been understood, in the media and among college students, Hemingway's comment is pretty good.

  12. Cognitive Ageing in Great Britain in the New Century: Cohort Differences in Episodic Memory.

    Directory of Open Access Journals (Sweden)

    Gindo Tampubolon

    Full Text Available Dementias in high income countries are set to be the third major burden of disease even as older people are increasingly required to think for themselves how to provide for their lives in retirement. Meanwhile the period of older age continues to extend with increase in life expectancy. This challenge demands an understanding of how cognition changes over an extended period in later life. But studying cognitive ageing in the population faces a difficulty from the fact that older respondents are liable to leave (attrite before study completion. This study tested three hypotheses: trajectories of cognitive ageing in Britain show an improvement beyond the age of 50; and they are lifted by secular improvement in cognition across cohorts; lastly they are susceptible to distortion due to attrition.Using the English Longitudinal Study of Ageing, this paper studied trajectories of episodic memory of Britons aged 50-89 from 2002 to 2013 (N = 5931. Using joint models the analysis found that levels of episodic memory follow a curvilinear shape, not a steady decline, in later life. The findings also revealed secular improvement in cognitive ageing such that as a cohort is being replaced episodic memory levels in the population improve. The analysis lastly demonstrated that failure to simultaneously model attrition can produce distorted pictures of cognitive ageing.Old age in this century is not necessarily a period dominated by cognitive decline. In identifying behavioural factors associated with better cognitive ageing, such as social connections of traditional and online kinds, the paper raises possibilities of mustering an adequate response to the cognition challenge.

  13. Regularized Estimation of Structural Instability in Factor Models: The US Macroeconomy and the Great Moderation

    DEFF Research Database (Denmark)

    Callot, Laurent; Kristensen, Johannes Tang

    This paper shows that the parsimoniously time-varying methodology of Callot and Kristensen (2015) can be applied to factor models.We apply this method to study macroeconomic instability in the US from 1959:1 to 2006:4 with a particular focus on the Great Moderation. Models with parsimoniously time...... dimensional by construction and sparse by assumption, is estimated using the Lasso. We apply this method to the estimation of static factor models and factor augmented autoregressions using a set of 190 quarterly observations of 144 US macroeconomic series from Stock and Watson (2009).We find......-varying parameters are models with an unknown number of break points at unknown locations. The parameters are assumed to follow a random walk with a positive probability that an increment is exactly equal to zero so that the parameters do not vary at every point in time. The vector of increments, which is high...

  14. Greatly enhanced intensity-difference squeezing via energy-level modulations in hot atomic media

    CERN Document Server

    Zhang, Da; Zhang, Zhaoyang; Zhang, Yiqi; Zhang, Yanpeng; Xiao, Min

    2016-01-01

    Narrow-band intensity-difference squeezing (IDS) beams have important applications in quantum metrology and quantum information. The best way to generate narrow-band IDS is to employ parametrically-amplified (PA) four-wave mixing (FWM) process in high-gain atomic media. Such IDS can be further enhanced by cascading multiple PA-FWM processes in separate atomic media. The complicated experimental setup, added losses and mechanical stability can limit the wide uses of such scheme in practical applications. Here, we show that by modulating/dressing the internal energy level(s) with additional laser(s), the degree of original IDS can be substantially increased. With an initial IDS of $-4.0\\pm0.1$ dB using PA-non-degenerate-FWM process in a three-level $\\Lambda$-type configuration, the degree of IDS can be enhanced to $-7.0\\pm0.1$ dB/$-8.1\\pm0.1$ dB when we use one/two laser beam(s) to modulate the involved ground/excited state(s). Our results show a low-loss, robust and efficient way to produce high degree of IDS ...

  15. Glacial isostatic adjustment at the Laurentide ice sheet margin: Models and observations in the Great Lakes region

    Science.gov (United States)

    Braun, Alexander; Kuo, Chung-Yen; Shum, C. K.; Wu, Patrick; van der Wal, Wouter; Fotopoulos, Georgia

    2008-10-01

    Glacial Isostatic Adjustment (GIA) modelling in North America relies on relative sea level information which is primarily obtained from areas far away from the uplift region. The lack of accurate geodetic observations in the Great Lakes region, which is located in the transition zone between uplift and subsidence due to the deglaciation of the Laurentide ice sheet, has prevented more detailed studies of this former margin of the ice sheet. Recently, observations of vertical crustal motion from improved GPS network solutions and combined tide gauge and satellite altimetry solutions have become available. This study compares these vertical motion observations with predictions obtained from 70 different GIA models. The ice sheet margin is distinct from the centre and far field of the uplift because the sensitivity of the GIA process towards Earth parameters such as mantle viscosity is very different. Specifically, the margin area is most sensitive to the uppermost mantle viscosity and allows for better constraints of this parameter. The 70 GIA models compared herein have different ice loading histories (ICE-3/4/5G) and Earth parameters including lateral heterogeneities. The root-mean-square differences between the 6 best models and the two sets of observations (tide gauge/altimetry and GPS) are 0.66 and 1.57 mm/yr, respectively. Both sets of independent observations are highly correlated and show a very similar fit to the models, which indicates their consistent quality. Therefore, both data sets can be considered as a means for constraining and assessing the quality of GIA models in the Great Lakes region and the former margin of the Laurentide ice sheet.

  16. Subcellular differences in handling Cu excess in three freshwater fish species contributes greatly to their differences in sensitivity to Cu

    Energy Technology Data Exchange (ETDEWEB)

    Eyckmans, Marleen, E-mail: marleen.eyckmans@ua.ac.be [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Blust, Ronny; De Boeck, Gudrun [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2012-08-15

    Since changes in metal distribution among tissues and subcellular fractions can provide insights in metal toxicity and tolerance, we investigated this partitioning of Cu in gill and liver tissue of rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gibel carp (Carassius auratus gibelio). These fish species are known to differ in their sensitivity to Cu exposure with gibel carp being the most tolerant and rainbow trout the most sensitive. After an exposure to 50 {mu}g/l (0.79 {mu}M) Cu for 24 h, 3 days, 1 week and 1 month, gills and liver of control and exposed fish were submitted to a differential centrifugation procedure. Interestingly, there was a difference in accumulated Cu in the three fish species, even in control fishes. Where the liver of rainbow trout showed extremely high Cu concentrations under control conditions, the amount of Cu accumulated in their gills was much less than in common and gibel carp. At the subcellular level, the gills of rainbow trout appeared to distribute the additional Cu exclusively in the biologically active metal pool (BAM; contains heat-denaturable fraction and organelle fraction). A similar response could be seen in gill tissue of common carp, although the percentage of Cu in the BAM of common carp was lower compared to rainbow trout. Gill tissue of gibel carp accumulated more Cu in the biologically inactive metal pool (BIM compared to BAM; contains heat-stable fraction and metal-rich granule fraction). The liver of rainbow trout seemed much more adequate in handling the excess Cu (compared to its gills), since the storage of Cu in the BIM increased. Furthermore, the high % of Cu in the metal-rich granule fraction and heat-stable fraction in the liver of common carp and especially gibel carp together with the better Cu handling in gill tissue, pointed out the ability of the carp species to minimize the disadvantages related to Cu stress. The differences in Cu distribution at the subcellular level of gills

  17. Development of models to inform a national Daily Landslide Hazard Assessment for Great Britain

    Science.gov (United States)

    Dijkstra, Tom A.; Reeves, Helen J.; Dashwood, Claire; Pennington, Catherine; Freeborough, Katy; Mackay, Jonathan D.; Uhlemann, Sebastian S.; Chambers, Jonathan E.; Wilkinson, Paul B.

    2015-04-01

    The British Geological Survey (BGS) provides landside hazard information as part of its strategic role. This includes, among others, the issuing of a national Daily Landslide Hazard Assessment (DLHA) one of the hazards assessments issued by the Natural Hazard Partnership. A range of tools are currently under development to further develop reliability and enhance the granularity of these assessments. The BGS has three datasets that support and underpin this research; the National Landslide Database (NLD), the DiGMap mass movement layer and GeoSure. The NLD holds more than 16,500 records of landslides across Great Britain (GB) stored in an Oracle database that is accessible through an ESRI ® ArcGIS interface. DiGMap comprises a digital map layer with outlines of all landslides recorded by field geologists. GeoSure is a BGS product that assesses the potential for ground movement across GB in six layers, one of which is landslide potential. The GeoSure landslide potential layer incorporates information on conditioning factors, such as local geology, geotechnical parameters and topography. These are combined within a GIS to derive a map showing where a landslide may occur under favourable conditions (e.g. persistent wet conditions due to adverse weather). Different types of terrain will be affected by different modes of landsliding and a series of hierarchical landslide domains have been established capturing the spatial consistency of slope deformation response. Each landslide domain represents an area of similar physiographic and geological characteristics which has shaped the style of landsliding (recognising relic, active and potentially active processes). In turn, this enables development of regional thresholds that are relevant to characteristic landslides in these domains. The wet period from summer 2012 into early spring 2013 resulted in a surge of recorded landslides, particularly in SW England and S Wales. Approximations of regional effective precipitation

  18. Steady-state numerical groundwater flow model of the Great Basin carbonate and alluvial aquifer system

    Science.gov (United States)

    Brooks, Lynette E.; Masbruch, Melissa D.; Sweetkind, Donald S.; Buto, Susan G.

    2014-01-01

    This report describes the construction, calibration, evaluation, and results of a steady-state numerical groundwater flow model of the Great Basin carbonate and alluvial aquifer system that was developed as part of the U.S. Geological Survey National Water Census Initiative to evaluate the nation’s groundwater availability. The study area spans 110,000 square miles across five states. The numerical model uses MODFLOW-2005, and incorporates and tests complex hydrogeologic and hydrologic elements of a conceptual understanding of an interconnected groundwater system throughout the region, including mountains, basins, consolidated rocks, and basin fill. The level of discretization in this model has not been previously available throughout the study area.

  19. Application of the Sea-Level Affecting Marshes Model (SLAMM 5.0) to Great Bay NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Sea-Level Affecting Marshes Model (SLAMM) report presents a model for projecting the effects of sea-level rise on coastal marshes and related habitats on Great...

  20. Application of the Sea-Level Affecting Marshes Model (SLAMM 6) to Great White Heron NWR : Final report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Sea-Level Affecting Marshes Model (SLAMM) report presents a model for projecting the effects of sea-level rise on coastal marshes and related habitats on Great...

  1. Feeding and energetics of the great scallop, Pecten maximus, through a DEB model

    Science.gov (United States)

    Lavaud, Romain; Flye-Sainte-Marie, Jonathan; Jean, Fred; Emmery, Antoine; Strand, Øivind; Kooijman, Sebastiaan A. L. M.

    2014-11-01

    We developed a full life-cycle bioenergetic model for the great scallop Pecten maximus relying on the concepts of the Dynamic Energy Budget (DEB) theory. The covariation method was implemented to estimate the parameters of a standard DEB model. Such models are able to predict various metabolic processes from a food availability marker and temperature in the environment. However, suspension-feeders are likely to feed on various trophic sources, from microalgae cells to detritus. They are also able to sort and select food particles very efficiently, depending on their size, energetic value or quality. The present model includes a mechanistic description of the feeding processes, based on Kooijman's Synthesizing Unit principle which allows to deal with several food sources. Moreover we tested the hypothesis of a differential selectivity between two potential substrates (phytoplankton cell and the remaining particulate organic matter). Simulations of shell length, daily shell growth rate, dry weight and gonado-somatic index (GSI) variations were realized and compared to field data from a monitoring conducted in the Bay of Brest (Brittany, France) for six years. The model shows its capacity to efficiently reproduce all life history traits of the wild great scallops. Predicted length data were estimated to the nearest millimeter. The fit of simulated weights to observed data was very satisfactory. GSI predictions were also in accordance with observations but improvements are required to better capture the sharp increase of gametogenesis at the beginning of the year. Finally, results bring evidences that P. maximus is actually preferentially feed on living algae cells rather than on the rest of organic particles.

  2. Forecasting effects of climate change on Great Lakes fisheries: models that link habitat supply to population dynamics can help

    Science.gov (United States)

    Jones, Michael L.; Shuter, Brian J.; Zhao, Yingming; Stockwell, Jason D.

    2006-01-01

    Future changes to climate in the Great Lakes may have important consequences for fisheries. Evidence suggests that Great Lakes air and water temperatures have risen and the duration of ice cover has lessened during the past century. Global circulation models (GCMs) suggest future warming and increases in precipitation in the region. We present new evidence that water temperatures have risen in Lake Erie, particularly during summer and winter in the period 1965–2000. GCM forecasts coupled with physical models suggest lower annual runoff, less ice cover, and lower lake levels in the future, but the certainty of these forecasts is low. Assessment of the likely effects of climate change on fish stocks will require an integrative approach that considers several components of habitat rather than water temperature alone. We recommend using mechanistic models that couple habitat conditions to population demographics to explore integrated effects of climate-caused habitat change and illustrate this approach with a model for Lake Erie walleye (Sander vitreum). We show that the combined effect on walleye populations of plausible changes in temperature, river hydrology, lake levels, and light penetration can be quite different from that which would be expected based on consideration of only a single factor.

  3. Predictive models in hazard assessment of Great Lakes contaminants for fish

    Science.gov (United States)

    Passino, Dora R. May

    1986-01-01

    A hazard assessment scheme was developed and applied to predict potential harm to aquatic biota of nearly 500 organic compounds detected by gas chromatography/mass spectrometry (GC/MS) in Great Lakes fish. The frequency of occurrence and estimated concentrations of compounds found in lake trout (Salvelinus namaycush) and walleyes (Stizostedion vitreum vitreum) were compared with available manufacturing and discharge information. Bioconcentration potential of the compounds was estimated from available data or from calculations of quantitative structure-activity relationships (QSAR). Investigators at the National Fisheries Research Center-Great Lakes also measured the acute toxicity (48-h EC50's) of 35 representative compounds to Daphnia pulex and compared the results with acute toxicity values generated by QSAR. The QSAR-derived toxicities for several chemicals underestimated the actual acute toxicity by one or more orders of magnitude. A multiple regression of log EC50 on log water solubility and molecular volume proved to be a useful predictive model. Additional models providing insight into toxicity incorporate solvatochromic parameters that measure dipolarity/polarizability, hydrogen bond acceptor basicity, and hydrogen bond donor acidity of the solute (toxicant).

  4. Composition of physiologically important fatty acids in great tits differs between urban and rural populations on a seasonal basis

    Directory of Open Access Journals (Sweden)

    Martin N Andersson

    2015-08-01

    Full Text Available Fatty acids (FA have crucial functions in animals, affecting e.g. inflammatory responses, thermoregulation, and cell membrane fluidity. Diet and ambient temperature affect animals’ FA composition, which, in turn, may influence these physiological processes. Great tits (Parus major −common in both urban and rural habitats− are mainly granivorous during winter and insectivorous during summer. These diets show pronounced differences in FA composition. Such variation has context-dependent effects on physiology, because the thermal environment, food availability, and levels of pro-inflammatory environmental stressors differ between urban and rural areas. Thus, we investigated how great tit plasma FA composition varied between urban and rural habitats and across seasons. Eight FAs differed between urban and rural birds. Among these, arachidonic acid (omega (ω-6 polyunsaturated FA with thermoregulatory and pro-inflammatory properties was more abundant in urban than rural birds in winter, whereas ω-3 FAs with anti-inflammatory properties were more abundant in rural birds. The difference in pro- and anti-inflammatory FAs suggest that the negative health effects that urban birds suffer from being exposed to higher levels of pollutants might be enhanced by an elevated inflammatory response. Eight FAs differed between winter and summer birds. This variation reflected the diet change: FAs common in seeds, e.g. oleic- and linoleic acid, were present in higher amounts in winter birds, whereas ω-3 polyunsaturated FAs that are common in caterpillars were more abundant in summer birds. Overall, a larger seasonal variation was seen among the urban birds. This study is the first to reveal a difference in FA composition between urban and rural populations for all animals studied to date. Future experiments should unravel the physiological implications of this variation, and ultimately, link its effects to fitness of animals with different physiological and

  5. The alteration of proportion of different lizard species compared to each other at The Great Pasture of Hajdubagos

    OpenAIRE

    Antal, Zsuzsanna

    2006-01-01

    Three different lizard species can be found at the great pasture of Hajúbagos. These are the balkan or crimean wall lizard (Podarcis taurica), the sand lizard (Lacerta agilis) and the green lizard (Lacerta viridis). All of them are protected by law in Hungary but while sand lizard and green lizard is common all over the country, the amount of the balkan wall lizard is decreasing. The main cause of this regrettable possession is the habitat degradation and thus habitat loss. Namely balkan wall...

  6. Wexler's Great Smoke Pall: a chemistry-climate model analysis of a singularly large emissions pulse

    Science.gov (United States)

    Field, R. D.; Voulgarakis, A.

    2011-12-01

    We model the effects of the smoke plume from what was arguably the largest forest fire in recorded history. The Chinchaga fire burned continuously during the summer of 1950 in northwestern Canada during a very dry fire season. On September 22nd, the fire made a major advance, burning an area of approximately 1400 km2. Ground and aircraft observations showed that from September 22 to 28, the smoke plume from the emissions pulse travelled over northern Canada, southward over the Great Lakes region and eastern US, across the Atlantic, and to Western Europe. Over the Great Lakes region, the plume remained thick enough to create twilight conditions in the mid-afternoon, and was estimated to have caused a 4 oC cooling at the surface. While many instances of long-range transport of wildfire emissions have been detected over the past decade, we know of no other wildfire which created such an acute effect on downward shortwave radiation at such a long distance. As a result, the fire was an important analogue event used in estimating the effects of a nuclear winter. Simulations with the nudged version of the GISS chemistry-climate model accurately capture the long-range transport pattern of the smoke emissions in the free-troposphere. The timing and location of aircraft observations of the plume over the eastern US, North Atlantic and the United Kingdom were well-matched to modeled anomalies of CO and aerosol optical depth. Further work will examine the model's ability to create twilight conditions during the day, and to provide an estimate of the consequent cooling effects at the surface from this remarkable emissions pulse.

  7. A system for environmental model coupling and code reuse: The Great Rivers Project

    Science.gov (United States)

    Eckman, B.; Rice, J.; Treinish, L.; Barford, C.

    2008-12-01

    As part of the Great Rivers Project, IBM is collaborating with The Nature Conservancy and the Center for Sustainability and the Global Environment (SAGE) at the University of Wisconsin, Madison to build a Modeling Framework and Decision Support System (DSS) designed to help policy makers and a variety of stakeholders (farmers, fish & wildlife managers, hydropower operators, et al.) to assess, come to consensus, and act on land use decisions representing effective compromises between human use and ecosystem preservation/restoration. Initially focused on Brazil's Paraguay-Parana, China's Yangtze, and the Mississippi Basin in the US, the DSS integrates data and models from a wide variety of environmental sectors, including water balance, water quality, carbon balance, crop production, hydropower, and biodiversity. In this presentation we focus on the modeling framework aspect of this project. In our approach to these and other environmental modeling projects, we see a flexible, extensible modeling framework infrastructure for defining and running multi-step analytic simulations as critical. In this framework, we divide monolithic models into atomic components with clearly defined semantics encoded via rich metadata representation. Once models and their semantics and composition rules have been registered with the system by their authors or other experts, non-expert users may construct simulations as workflows of these atomic model components. A model composition engine enforces rules/constraints for composing model components into simulations, to avoid the creation of Frankenmodels, models that execute but produce scientifically invalid results. A common software environment and common representations of data and models are required, as well as an adapter strategy for code written in e.g., Fortran or python, that still enables efficient simulation runs, including parallelization. Since each new simulation, as a new composition of model components, requires calibration

  8. Modelling the emerging pollutant diclofenac with the GREAT-ER model: Application to the Llobregat River Basin

    Energy Technology Data Exchange (ETDEWEB)

    Aldekoa, Joana, E-mail: joaalma2@cam.upv.es [Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Medici, Chiara [Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Osorio, Victoria; Pérez, Sandra [Institute of Environmental Assessment and Water Research, Jordi Girona 18-26, 08034 Barcelona (Spain); Marcé, Rafael [Catalan Institute for Water Research, Emili Grahit 101, 17003 Girona (Spain); Barceló, Damià [Institute of Environmental Assessment and Water Research, Jordi Girona 18-26, 08034 Barcelona (Spain); Francés, Félix [Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain)

    2013-12-15

    Highlights: • Diclofenac levels were measured in 14 sampling sites of the Llobregat River (Spain). • GREAT-ER model was used to simulate diclofenac concentrations in the Llobregat River. • Deterministic and stochastic modelling approaches were contrasted. • Diclofenac discharge into the basin was estimated for the studied period. • Consistent degradation rates were predicted and compared with literature values. -- Abstract: The present research aims at giving an insight into the increasingly important issue of water pollution due to emerging contaminants. In particular, the source and fate of the non-steroidal anti-inflammatory drug diclofenac have been analyzed at catchment scale for the Llobregat River in Catalonia (Spain). In fact, water from the Llobregat River is used to supply a significant part of the Metropolitan Area of Barcelona. At the same time, 59 wastewater treatment plants discharge into this basin. GREAT-ER model has been implemented in this basin in order to reproduce a static balance for this pollutant for two field campaigns data set. The results highlighted the ability of GREAT-ER to simulate the diclofenac concentrations in the Llobregat Catchment; however, this study also pointed out the urgent need for longer time series of observed data and a better knowledge of wastewater plants outputs and their parameterization in order to obtain more reliable results.

  9. Interseismic Coupling Models and their interactions with the Sources of Large and Great Earthquakes

    Science.gov (United States)

    Chlieh, M.; Perfettini, H.; Avouac, J. P.

    2009-04-01

    Recent observations of heterogeneous strain build up reported from subduction zones and seismic sources of large and great interplate earthquakes indicate that seismic asperities are probably persistent features of the megathrust. The Peru Megathrust produce recurrently large seismic events like the 2001 Mw 8.4, Arequipa earthquake or the 2007 Mw 8.0, Pisco earthquake. The peruvian subduction zone provide an exceptional opportunity to understand the eventual relationship between interseismic coupling, large megathrust ruptures and the frictional properties of the megathrust. An emerging concept is a megathrust with strong locked fault patches surrounded by aseismic slip. The 2001, Mw 8.4 Arequipa earthquake ruptured only the northern portion of the patch that had ruptured already during the great 1868 Mw~8.8 earthquake and that had remained locked in the interseismic period. The 2007 Mw 8.0 Pisco earthquake ruptured the southern portion of the 1746 Mw~8.5 event. The moment released in 2007 amounts to only a small fraction of the deficit of moment that had accumulated since the 1746 great earthquake. Then, the potential for future large megathrust events in Central and Southern Peru area remains large. These recent earthquakes indicate that a same portion of a megathrust can rupture in different ways depending on whether asperities break as isolated events or jointly to produce a larger rupture. The spatial distribution of frictional properties of the megathrust could be the cause for a more complex earthquakes sequence from one seismic cycle to another. The subduction of geomorphologic structure like the Nazca ridge could be the cause for a lower coupling there.

  10. Nutrient inputs to the Laurentian Great Lakes by source and watershed estimated using SPARROW watershed models

    Science.gov (United States)

    Robertson, Dale M.; Saad, David A.

    2011-01-01

    Nutrient input to the Laurentian Great Lakes continues to cause problems with eutrophication. To reduce the extent and severity of these problems, target nutrient loads were established and Total Maximum Daily Loads are being developed for many tributaries. Without detailed loading information it is difficult to determine if the targets are being met and how to prioritize rehabilitation efforts. To help address these issues, SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were developed for estimating loads and sources of phosphorus (P) and nitrogen (N) from the United States (U.S.) portion of the Great Lakes, Upper Mississippi, Ohio, and Red River Basins. Results indicated that recent U.S. loadings to Lakes Michigan and Ontario are similar to those in the 1980s, whereas loadings to Lakes Superior, Huron, and Erie decreased. Highest loads were from tributaries with the largest watersheds, whereas highest yields were from areas with intense agriculture and large point sources of nutrients. Tributaries were ranked based on their relative loads and yields to each lake. Input from agricultural areas was a significant source of nutrients, contributing ∼33-44% of the P and ∼33-58% of the N, except for areas around Superior with little agriculture. Point sources were also significant, contributing ∼14-44% of the P and 13-34% of the N. Watersheds around Lake Erie contributed nutrients at the highest rate (similar to intensively farmed areas in the Midwest) because they have the largest nutrient inputs and highest delivery ratio.

  11. Eco-Efficiency Model for Evaluating Feedlot Rations in the Great Plains, United States.

    Science.gov (United States)

    Hengen, Tyler J; Sieverding, Heidi L; Cole, Noel A; Ham, Jay M; Stone, James J

    2016-07-01

    Environmental impacts attributable to beef feedlot production provide an opportunity for economically linked efficiency optimization. Eco-efficiency models are used to optimize production and processes by connecting and quantifying environmental and economic impacts. An adaptable, objective eco-efficiency model was developed to assess the impacts of dietary rations on beef feedlot environmental and fiscal cost. The hybridized model used California Net Energy System modeling, life cycle assessment, principal component analyses (PCA), and economic analyses. The model approach was based on 38 potential feedlot rations and four transportation scenarios for the US Great Plains for each ration to determine the appropriate weight of each impact. All 152 scenarios were then assessed through a nested PCA to determine the relative contributing weight of each impact and environmental category to the overall system. The PCA output was evaluated using an eco-efficiency model. Results suggest that water, ecosystem, and human health emissions were the primary impact category drivers for feedlot eco-efficiency scoring. Enteric CH emissions were the greatest individual contributor to environmental performance (5.7% of the overall assessment), whereas terrestrial ecotoxicity had the lowest overall contribution (0.2% of the overall assessment). A well-balanced ration with mid-range dietary and processing energy requirements yielded the most eco- and environmentally efficient system. Using these results, it is possible to design a beef feed ration that is more economical and environmentally friendly. This methodology can be used to evaluate eco-efficiency and to reduce researcher bias of other complex systems.

  12. Modelling the fate of marine debris along a complex shoreline: Lessons from the Great Barrier Reef

    Science.gov (United States)

    Critchell, K.; Grech, A.; Schlaefer, J.; Andutta, F. P.; Lambrechts, J.; Wolanski, E.; Hamann, M.

    2015-12-01

    The accumulation of floating anthropogenic debris in marine and coastal areas has environmental, economic, aesthetic, and human health impacts. Until now, modelling the transport of such debris has largely been restricted to the large-scales of open seas. We used oceanographic modelling to identify potential sites of debris accumulation along a rugged coastline with headlands, islands, rocky coasts and beaches. Our study site was the Great Barrier Reef World Heritage Area that has an emerging problem with debris accumulation. We found that the classical techniques of modelling the transport of floating debris models are only moderately successful due to a number of unknowns or assumptions, such as the value of the wind drift coefficient, the variability of the oceanic forcing and of the wind, the resuspension of some floating debris by waves, and the poorly known relative contribution of floating debris from urban rivers and commercial and recreational shipping. Nevertheless the model was successful in reproducing a number of observations such as the existence of hot spots of accumulation. The orientation of beaches to the prevailing wind direction affected the accumulation rate of debris. The wind drift coefficient and the exact timing of the release of the debris at sea affected little the movement of debris originating from rivers but it affected measurably that of debris originating from ships. It was thus possible to produce local hotspot maps for floating debris, especially those originating from rivers. Such modelling can be used to inform local management decisions, and it also identifies likely priority research areas to more reliably predict the trajectory and landing points of floating debris.

  13. Modelling the emerging pollutant diclofenac with the GREAT-ER model: application to the Llobregat River Basin.

    Science.gov (United States)

    Aldekoa, Joana; Medici, Chiara; Osorio, Victoria; Pérez, Sandra; Marcé, Rafael; Barceló, Damià; Francés, Félix

    2013-12-15

    The present research aims at giving an insight into the increasingly important issue of water pollution due to emerging contaminants. In particular, the source and fate of the non-steroidal anti-inflammatory drug diclofenac have been analyzed at catchment scale for the Llobregat River in Catalonia (Spain). In fact, water from the Llobregat River is used to supply a significant part of the Metropolitan Area of Barcelona. At the same time, 59 wastewater treatment plants discharge into this basin. GREAT-ER model has been implemented in this basin in order to reproduce a static balance for this pollutant for two field campaigns data set. The results highlighted the ability of GREAT-ER to simulate the diclofenac concentrations in the Llobregat Catchment; however, this study also pointed out the urgent need for longer time series of observed data and a better knowledge of wastewater plants outputs and their parameterization in order to obtain more reliable results.

  14. Modelling Growth of Juvenile Crown-of-Thorns Starfish on the Northern Great Barrier Reef

    Directory of Open Access Journals (Sweden)

    Jennifer Wilmes

    2016-12-01

    Full Text Available The corallivorous crown-of-thorns starfish (Acanthaster spp. is a major cause of coral mortality on Indo-Pacific reefs. Despite considerable research into the biology of crown-of-thorns starfish, our understanding of the early post-settlement life stage has been hindered by the small size and cryptic nature of recently settled individuals. Most growth rates are derived from either laboratory studies or field studies conducted in Fiji and Japan. The Great Barrier Reef (GBR is currently experiencing its fourth recorded outbreak and population models to inform the progression of outbreaks lack critical growth rates of early life history stages. High numbers of 0+ year juveniles (n = 3532 were measured during extensive surveys of 64 reefs on the northern GBR between May and December 2015. An exponential growth model was fitted to the size measurement data to estimate monthly ranges of growth rates for 0+ year juveniles. Estimated growth rates varied considerably and increased with age (e.g., 0.028–0.041 mm·day−1 for one-month-old juveniles versus 0.108–0.216 mm·day−1 for twelve-month-old juveniles. This pioneering study of 0+ year juveniles on the GBR will inform population models and form the basis for more rigorous ongoing research to understand the fate of newly settled Acanthaster spp.

  15. Comparative Study of Various SDLC Models on Different Parameters

    Directory of Open Access Journals (Sweden)

    Prateek Sharma

    2015-04-01

    Full Text Available The success of a software development project greatly depends upon which process model is used. This paper emphasizes on the need of using appropriate model as per the application to be developed. In this paper we have done the comparative study of the following software models namely Waterfall, Prototype, RAD (Rapid Application Development Incremental, Spiral, Build and Fix and V-shaped. Our aim is to create reliable and cost effective software and these models provide us a way to develop them. The main objective of this research is to represent different models of software development and make a comparison between them to show the features of each model.

  16. Modeling bed-load transport of coarse sediments in the Great Bay Estuary, New Hampshire

    Science.gov (United States)

    Bilgili, A.; Swift, M. R.; Lynch, D. R.; Ip, J. T. C.

    2003-12-01

    Current, sea level and bed-load transport are investigated in the Lower Piscataqua River section of the Great Bay Estuary, New Hampshire, USA—a well-mixed and geometrically complex system with low freshwater input, having main channel tidal currents ranging between 0.5 and 2 m s -1. Current and sea level forced by the M 2M 4M 6 tides at the estuarine mouth are simulated by a vertically averaged, non-linear, time-stepping finite element model. The hydrodynamic model uses a fixed boundary computational domain and accounts for flooding-drying of tidal flats by making use of a groundwater component. Inertia terms are neglected in comparison with pressure gradient and bottom friction terms, which is consistent with the observed principal dynamic balance for this section of the system. The accuracy of hydrodynamic predictions in the study area is demonstrated by comparison with four tidal elevation stations and two cross-section averaged current measurements. Simulated current is then used to model bed-load transport in the vicinity of a rapidly growing shoal located in the main channel of the lower system. Consisting of coarse sand and gravel, the shoal must be dredged every five to eight years. Two approaches are taken—an Eulerian parametric method in which nodal bed-load flux vectors are averaged over the tidal cycle and a Lagrangian particle tracking approach in which a finite number of sediment particles are released and tracked. Both methods yield pathways and accumulations in agreement with the observed shoal formation and the long-term rate of sediment accumulation in the shoal area.

  17. Solution model of nonlinear integral adjustment including different kinds of observing data with different precisions

    Institute of Scientific and Technical Information of China (English)

    郭金运; 陶华学

    2003-01-01

    In order to process different kinds of observing data with different precisions, a new solution model of nonlinear dynamic integral least squares adjustment was put forward, which is not dependent on their derivatives. The partial derivative of each component in the target function is not computed while iteratively solving the problem. Especially when the nonlinear target function is more complex and very difficult to solve the problem, the method can greatly reduce the computing load.

  18. Life history differences between fat and lean morphs of lake charr (Salvelinus namaycush) in Great Slave Lake, Northwest Territories, Canada

    Science.gov (United States)

    Hansen, Michael J.; Nate, Nancy A.; Chavarie, Louise; Muir, Andrew M.; Zimmerman, Mara S.; Krueger, Charles C.

    2016-01-01

    Life history characteristics (size, age, plumpness, buoyancy, survival, growth, and maturity) were compared between fat and lean morphs of lake charr Salvelinus namaycush in Great Slave Lake, Canada, to determine if differences may reflect effects of resource polymorphism. Lake charr were sampled using graded-mesh gill nets set in three depth strata. Of 236 lake charr captured, 122 were a fat morph and 114 were a lean morph. Males and females did not differ from each other in any attributes for either fat or lean morphs. The fat morph averaged 15 mm longer, 481 g heavier, and 4.7 years older than the lean morph. The fat morph averaged 26% heavier and 48% more buoyant at length than the lean morph. Survival of the fat morph was 1.7% higher than that of the lean morph. The fat morph grew at a slower annual rate to a shorter asymptotic length than the lean morph. Fat and lean morphs matured at similar lengths and ages. We concluded that the connection between resource polymorphism and life histories in lean versus fat lake charr suggests that morph-specific restoration objectives may be needed in lakes where lake charr diversity is considered to be a restoration goal.

  19. Different prion disease phenotypes result from inoculation of cattle with two temporally separated sources of sheep scrapie from Great Britain

    Directory of Open Access Journals (Sweden)

    Hawkins Steve AC

    2006-10-01

    Full Text Available Abstract Background Given the theoretical proposal that bovine spongiform encephalopathy (BSE could have originated from sheep scrapie, this study investigated the pathogenicity for cattle, by intracerebral (i.c. inoculation, of two pools of scrapie agents sourced in Great Britain before and during the BSE epidemic. Two groups of ten cattle were each inoculated with pools of brain material from sheep scrapie cases collected prior to 1975 and after 1990. Control groups comprised five cattle inoculated with sheep brain free from scrapie, five cattle inoculated with saline, and for comparison with BSE, naturally infected cattle and cattle i.c. inoculated with BSE brainstem homogenate from a parallel study. Phenotypic characterisation of the disease forms transmitted to cattle was conducted by morphological, immunohistochemical, biochemical and biological methods. Results Disease occurred in 16 cattle, nine inoculated with the pre-1975 inoculum and seven inoculated with the post-1990 inoculum, with four cattle still alive at 83 months post challenge (as at June 2006. The different inocula produced predominantly two different disease phenotypes as determined by histopathological, immunohistochemical and Western immunoblotting methods and biological characterisation on transmission to mice, neither of which was identical to BSE. Whilst the disease presentation was uniform in all scrapie-affected cattle of the pre-1975 group, the post-1990 inoculum produced a more variable disease, with two animals sharing immunohistochemical and molecular profile characteristics with animals in the pre-1975 group. Conclusion The study has demonstrated that cattle inoculated with different pooled scrapie sources can develop different prion disease phenotypes, which were not consistent with the phenotype of BSE of cattle and whose isolates did not have the strain typing characteristics of the BSE agent on transmission to mice.

  20. Flow of groundwater from great depths into the near surface deposits - modelling of a local domain in northeast Uppland

    Energy Technology Data Exchange (ETDEWEB)

    Holmen, Johan G.; Forsman, Jonas [Golder Associates, Stockholm (Sweden)

    2005-01-15

    Purpose: To study the flow of groundwater from rock masses at great depths and into the surface near deposits by use of mathematical models; and to estimate the spatial and temporal distribution of groundwater from great depths in the surface near deposits (quaternary deposits). The study is about the hydraulic interaction between the geosphere and the biosphere. Methodology: The system studied is represented by time dependent three dimensional mathematical models. The models include groundwater flows in the rock mass and in the quaternary deposits as well as surface water flows. The established groundwater models have such a resolution (degree of detail) that both rock masses at great depth and near surface deposits are included in the flow system studied. The modelling includes simulations under both steady state conditions and transient conditions The transient simulations represents the varying state of the groundwater system studied, caused by the variation in hydro-meteorological conditions during a normal year, a wet-year and a dry-year. The boundary condition along the topography of the model is a non-linear boundary condition, representing the ground surface above the sea and the varying actual groundwater recharge. Area studied: The area studied is located in Sweden, in the Northeast of the Uppland province, close to the Forsmark nuclear power plant. Water balance modelling: To obtain three significantly different groundwater recharge periods for the transient groundwater flow simulations a water balance modelling was carried out based on a statistical analysis of available hydro-meteorological data. To obtain a temporal distribution of the runoff (i.e. potential groundwater recharge), we have conducted a numerical time dependent water balance modelling. General conclusions of groundwater modelling: The discharge areas for the flow paths from great depth are given by the topography and located along valleys and lakes; the spatial and temporal extension of

  1. Modeling of temporal patterns and sources of atmospherically transported and deposited pesticides in ecosystems of concern: A case study of toxaphene in the Great Lakes

    Science.gov (United States)

    Li, Rong; Jin, Jiming

    2013-10-01

    have adverse effects on human health and the environment and can be transported through the atmosphere from application sites and deposited to sensitive ecosystems. This study applies a comprehensive multimedia regional pesticide fate and chemical transport modeling system that we developed to investigate the atmospheric transport and deposition of toxaphene to the Great Lakes. Simulated results predict a significant amount of toxaphene (~350 kg) being transported through the atmosphere and deposited into the Great Lakes in the simulation year. Results also show that U.S. residues and global background are major sources to toxaphene deposition into the Great Lakes and atmospheric concentrations in the region. While the U.S. residues are the dominant source in warm months, the background dominates during winter months. In addition, different sources have different influences on the individual Great Lakes due to their proximity and relative geographical positions to the sources; U.S. residues are the dominant source to Lakes Ontario, Erie, Huron, and Michigan, but they are a much less important source to Lake Superior. These results shed light on the mystery that observed toxaphene concentrations in Great Lakes' lake trout and smelt declined between 1982 and 1992 in four of the Great Lakes except Lake Superior. While monthly total depositions to Lakes Ontario, Erie, Huron, and Michigan have clear seasonal variability with much greater values in April, May, and June, monthly total depositions to Lake Superior are more uniformly distributed over the year with comparatively greater levels in cold months.

  2. Bayesian Averaging over Many Dynamic Model Structures with Evidence on the Great Ratios and Liquidity Trap Risk

    NARCIS (Netherlands)

    R.W. Strachan (Rodney); H.K. van Dijk (Herman)

    2008-01-01

    textabstractA Bayesian model averaging procedure is presented that makes use of a finite mixture of many model structures within the class of vector autoregressive (VAR) processes. It is applied to two empirical issues. First, stability of the Great Ratios in U.S. macro-economic time series is inves

  3. Soil erosion under climate change in Great Britain: long-term simulations using high-resolution regional models

    Science.gov (United States)

    Ciampalini, Rossano; Kendon, Elizabeth; Constantine, José Antonio; Schindewolf, Marcus; Hall, Ian

    2016-04-01

    Twenty-first century climate change simulations for Great Britain reveal an increase in heavy precipitation that may lead to widespread soil loss and reduced soil carbon stores by increasing the likelihood of surface runoff. We find the quality and resolution of the simulated rainfall used to drive soil loss variation can widely influence the results. Hourly high definition rainfall simulations from a 1.5km resolution regional climate model are used to examine the soil erosion response in two UK catchments. The catchments have different sensitivity to soil erosion. "Rother" in West Sussex, England, reports some of the most erosive events that have been observed during the last 50 years in the UK. "Conwy" in North Wales, is resilient to soil erosion because of the abundant natural vegetation cover and very limited agricultural practises. We modelled with Erosion3D to check variations in soil erosion as influenced by climate variations for the periods 1996-2009 and 2086-2099. Our results indicate the Rother catchment is the most erosive, while the Conwy catchment is confirmed as the more resilient to soil erosion. The values of the reference-base period are consistent with the values of those locally observed in the previous decades. A soil erosion comparison for the two periods shows an increasing of sediment production (off-site erosion) for the end of the century at about 27% in the Rother catchment and about 50% for the Conwy catchment. The results, thanks to high-definition rainfall predictions, throw some light on the effect of climatic change effects in Great Britain.

  4. Cutting the Gordian Knot of World History: Giovanni Arrighi's Model of the Great Divergence and Convergence

    Directory of Open Access Journals (Sweden)

    Jan-Frederik Abbeloos

    2015-08-01

    Full Text Available This essay evaluates the new road Giovanni Arrighi paves in Adam Smith in Beijing (2007 in relation to the scholarly debate on Europe's Great Divergence and the remarkable resurgence of East Asia in the global economy at the end of the twentieth century. At the center of Adam Smith in Beijing is the argument that the probability has increased that we are witnessing the formation of an "East Asian-centered world-market society, " rivaling the historical "capitalist world-economy ". We show how Arrighi 's discovery of East Asia has led him to supplement the analysis of historical capitalism he presented in The Long Twentieth Century (1994. This brings about uncertainties and problems. On the one hand, Arrighi is clear in his view on the different paths of economic development followed by the Europe-centered capitalist world-system, and the Chinese-centered market-oriented world-system. These paths remained largely separate until deep into the nineteenth century. On the other hand, Arrighi is less clear on how the Asian market-oriented legacy survived its incorporation into a globalizing capitalist world-economy, a crucial precondition for Arrighi's political message. Characterized as a process of subordination, hybridization, or fusion, it remains difficult to extract from Arrighi an unambiguous understanding of the place of China and East Asia within the capitalist world-system. It is just as hard to understand the nature of that "interstitial" system itself These conceptual and theoretical uncertainties suggest a central question and problem that hangs over Adam Smith in Beijing: What remains of the capitalist world-system as an analytical category that allows us to understand economic history and our possible futures?

  5. Major Differences between the Jerome Model and the Horace Model

    Institute of Scientific and Technical Information of China (English)

    朱艳

    2014-01-01

    There are three famous translation models in the field of translation: the Jerome model, the Horace model and the Schleiermacher model. The production and development of the three models have significant influence on the translation. To find the major differences between the two western classical translation theoretical models, we discuss the Jerome model and the Hor-ace model deeply in this paper.

  6. 水温—冰盖模式对大湖水面温度的模拟%SPATIALLY DISTRIBUTED WATER SURFACE TEMPERATURE MODELING FOR THE GREAT LAKES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper describes the development and validation of a water temperature model for the Great Lakes.This model is keyed to simulate horizontally and temporally varying surface temperature.An ice cover model is coupled with the water temper ature model,forming a spatially distributed thermodynamic model for the Great La kes.This model can be used to give long-term or short-term simulations of wate r surface temperature and ice cover for the Great Lakes.

  7. The Production of National Scale Models for Natural Geohazards in Great Britain

    Science.gov (United States)

    Royse, Katherine

    2010-05-01

    Although Great Britain (GB), is untroubled by large-magnitude earthquakes or tsunamis, there is a growing financial and health threat from geohazards affecting both people and property (principally from flooding, shrink-swell clays, landslides, coastal erosion, radon and soluble rocks). This is both in terms of direct costs for remediation and indirectly from higher insurance premiums. For example, the Association of British Insurers reported that the 2007 summer floods cost Britain approximately £3billion; a figure which is predicted to triple every decade due to the increasing value of assets and potential increase in flood occurrence due to environmental change. Remediation from damage caused by shrink-swell clays alone is estimated to cost the insurance industry an average of over £300 million per year an amount that will inevitably increase given current predictions for future climate it is therefore essential that we are able to quantify and strategically assess the occurrence of geohazards in GB as a whole. This will enable us to understand their relationship to critical infrastructure (hospitals, utilities and major transportation routes), industry and major urban centres and provide an understanding of the environmental impacts that an increase in any one of these geohazards might have on, the lives of the British people, for example, flooding and associated landslides can affect the mobilisation of confined contaminants and subsequently the character and use of available land in the future. Since 2002 the British Geological Survey (BGS) has been developing national-scale models of natural geohazards in GB for just this purpose. These include, to date, landslides, shrink-swell, soluble rocks, compressible and collapsible deposits, groundwater flooding, geological indicators of flooding, radon potential, potentially harmful elements in soil, and mining hazards. The models have been created using a combination of expert knowledge (from both within BGS and

  8. The use of process models to inform and improve statistical models of nitrate occurrence, Great Miami River Basin, southwestern Ohio

    Science.gov (United States)

    Walter, Donald A.; Starn, J. Jeffrey

    2013-01-01

    local hydrologic settings, would inform and improve the development of statistical models can be implicitly estimated by evaluating the differences between explanatory variables estimated from the contributing recharge areas and the circular buffers used to develop existing statistical models. The larger the difference in estimated variables, the more likely that statistical models would be changed, and presumably improved, if explanatory variables estimated from contributing recharge areas were used in model development. Comparing model predictions from the two sets of estimated variables would further quantify—albeit implicitly—how an improved, physically based estimate of explanatory variables would be reflected in model predictions. Differences between the two sets of estimated explanatory variables and resultant model predictions vary spatially; greater differences are associated with areas of steep hydraulic gradients. A direct comparison, however, would require the development of a separate set of statistical models using explanatory variables from contributing recharge areas. Area-weighted means of three environmental variables—silt content, alfisol content, and depth to water from the U.S. Department of Agriculture State Soil Geographic (STATSGO) data—and one nitrogen-source variable (fertilizer-application rate from county data mapped to Enhanced National Land Cover Data 1992 (NLCDe 92) agricultural land use) can vary substantially between circular buffers and volume-equivalent contributing recharge areas and among contributing recharge areas for different sets of well variables. The differences in estimated explanatory variables are a function of the same factors affecting the contributing recharge areas as well as the spatial resolution and local distribution of the underlying spatial data. As a result, differences in estimated variables between circular buffers and contributing recharge areas are complex and site specific as evidenced by differences

  9. In the transmission of information, the great potential of model-based coding with the SP theory of intelligence

    OpenAIRE

    Wolff, J Gerard

    2016-01-01

    Model-based coding, described by John Pierce in 1961, has great potential to reduce the volume of information that needs to be transmitted in moving big data, without loss of information, from one place to another, or in lossless communications via the internet. Compared with ordinary compression methods, this potential advantage of model-based coding in the transmission of data arises from the fact that both the transmitter ("Alice") and the receiver ("Bob") are equipped with a grammar for t...

  10. Kansas environmental and resource study: A Great Plains model, tasks 1-6

    Science.gov (United States)

    Haralick, R. M.; Kanemasu, E. T.; Morain, S. A.; Yarger, H. L. (Principal Investigator); Ulaby, F. T.; Shanmugam, K. S.; Williams, D. L.; Mccauley, J. R.; Mcnaughton, J. L.

    1972-01-01

    There are no author identified significant results in this report. Environmental and resources investigations in Kansas utilizing ERTS-1 imagery are summarized for the following areas: (1) use of feature extraction techniqued for texture context information in ERTS imagery; (2) interpretation and automatic image enhancement; (3) water use, production, and disease detection and predictions for wheat; (4) ERTS-1 agricultural statistics; (5) monitoring fresh water resources; and (6) ground pattern analysis in the Great Plains.

  11. Gregory the Great's metaphor of the physician of the heart as a model for pastoral identity.

    Science.gov (United States)

    McGrath-Merkle, Clare

    2011-06-01

    The identity of the Roman Catholic priesthood remains in serious crisis. Scholars have called for a return to traditional sources to find possible solutions, including the Early Church Fathers and the Hebrew Bible. Following Oden, this article further explores Pope Gregory the Great's The Book of Pastoral Rule and his ideals regarding pastoral identity. Of unique importance is his notion of the pastor as a "physician of the heart," unrecognized previously as central to his project.

  12. Application of the GREAT-ER model for environmental risk assessment of nonylphenol and nonylphenol ethoxylates in China.

    Science.gov (United States)

    Zhang, Lai; Cao, Yan; Hao, Xuewen; Zhang, Yongyong; Liu, Jianguo

    2015-12-01

    The environmental risk presented by "down-the-drain" chemicals to receiving rivers in large urban areas has received increasing attention in recent years. Geo-referenced Regional Environmental Assessment Tool for European Rivers (GREAT-ER) is a typical river catchment model that has been specifically developed for the risk assessment of these chemicals and applied in many European rivers. By utilizing the new version of the model, GREAT-ER 3.0, which is the first completely open source software for worldwide application, this study represents the first attempt to conduct an application of GREAT-ER in the Wenyu River of China. Aquatic exposure simulation and an environmental risk assessment of nonylphenol (NP) and its environmental precursor nonylphenol ethoxylates (NPEOs) were conducted effectively by GREAT-ER model, since NP is one of typical endocrine disrupting chemicals (EDCs) and its environmental precursor NPEOs as a "down-the-drain" chemical are extensively used in China. In the result, the predicted environmental concentrations (PECs) of NP and NPEOs in the water of Wenyu River were 538 and 4320 ng/L, respectively, at the regional scale, and 1210 and 8990 ng/L, respectively, at the local scale. From the results profile of the RCR, the combination of high emissions from large STPs with insufficient dilution of the river caused the high RCR. The PECs of NP in the sediment were in the range of 216.8-8218.3 ng/g (dry weight), which was consistent with the available monitoring data. The study showed the worldwide applicability and reliability of GREAT-ER as a river catchment model for the risk assessment of these chemicals and also revealed the general environmental risks presented by NP and NPEOs in the Wenyu River catchment in Beijing due to the extensive use of these chemicals. The results suggest that specific control or treatment measures are probably warranted for these chemicals to reduce their discharge in major cities.

  13. Segmentation of the heart and great vessels in CT images using a model-based adaptation framework.

    Science.gov (United States)

    Ecabert, Olivier; Peters, Jochen; Walker, Matthew J; Ivanc, Thomas; Lorenz, Cristian; von Berg, Jens; Lessick, Jonathan; Vembar, Mani; Weese, Jürgen

    2011-12-01

    Recently, model-based methods for the automatic segmentation of the heart chambers have been proposed. An important application of these methods is the characterization of the heart function. Heart models are, however, increasingly used for interventional guidance making it necessary to also extract the attached great vessels. It is, for instance, important to extract the left atrium and the proximal part of the pulmonary veins to support guidance of ablation procedures for atrial fibrillation treatment. For cardiac resynchronization therapy, a heart model including the coronary sinus is needed. We present a heart model comprising the four heart chambers and the attached great vessels. By assigning individual linear transformations to the heart chambers and to short tubular segments building the great vessels, variable sizes of the heart chambers and bending of the vessels can be described in a consistent way. A configurable algorithmic framework that we call adaptation engine matches the heart model automatically to cardiac CT angiography images in a multi-stage process. First, the heart is detected using a Generalized Hough Transformation. Subsequently, the heart chambers are adapted. This stage uses parametric as well as deformable mesh adaptation techniques. In the final stage, segments of the large vascular structures are successively activated and adapted. To optimize the computational performance, the adaptation engine can vary the mesh resolution and freeze already adapted mesh parts. The data used for validation were independent from the data used for model-building. Ground truth segmentations were generated for 37 CT data sets reconstructed at several cardiac phases from 17 patients. Segmentation errors were assessed for anatomical sub-structures resulting in a mean surface-to-surface error ranging 0.50-0.82mm for the heart chambers and 0.60-1.32mm for the parts of the great vessels visible in the images.

  14. How do small differences in nonidentical pulse-coupled oscillators induce great changes in their synchronous behavior?

    Science.gov (United States)

    Ramírez Ávila, G. M.; Kurths, J.; Guisset, J. L.; Deneubourg, J. L.

    2014-12-01

    We studied synchronization and clustering in two types of pulse-coupled oscillators, namely, integrate-and-fire and light-controlled oscillators. We considered for the analysis globally coupled oscillators, either by a mean-field type coupling or a distance-dependent one. Using statistically diverse measures such as the transient, probability of total synchronization, fraction of clustered oscillators, mean size, and mean number of clusters, we describe clustering and synchronous behavior for populations of nonidentical oscillators and perform a comparative analysis of the behavioral differences and similitudes among these types of oscillators. Considering a mean-field approach, we found high probability of total synchronization in all cases for integrate-and-fire oscillators; on the other hand, in a more realistic situation, for light-controlled oscillators, i.e., when oscillators do not fire instantaneously, the probability of total synchronization decreases drastically for small differences among the oscillators and subsequently, for larger differences, it slightly increases. When the coupling strength depends on the distance, the probability of total synchronization plummets dramatically with the number of oscillators especially in the case of integrate-and-fire oscillators. The latter constitutes an interesting result because it indicates that in realistic situations, the probability of total synchronization is not very high for a population of pulse-coupled oscillators; this entails that its utilization as a paradigmatic model of total synchronization does not suit well, especially when the coupling depends on the distance. This article is dedicated to our good friend and colleague Hilda Cerdeira as a tribute to the scientific work developed over her career.

  15. In vivo and in vitro phenotypic differences between Great Lakes VHSV genotype IVb isolates with sequence types vcG001 and vcG002

    Science.gov (United States)

    Imanse, Sierra M.; Cornwell, Emily R.; Getchell, Rodman G.; Kurath, Gael; Bowser, Paul R.

    2014-01-01

    Viral hemorrhagic septicemia virus (VHSV) is an aquatic rhabdovirus first recognized in farmed rainbow trout in Denmark. In the past decade, a new genotype of this virus, IVb was discovered in the Laurentian Great Lakes basin and has caused several massive die-offs in some of the 28 species of susceptible North American freshwater fishes. Since its colonization of the Great Lakes, several closely related sequence types within genotype IVb have been reported, the two most common of which are vcG001 and vcG002. These sequence types have different spatial distributions in the Great Lakes. The aim of this study was to determine whether the genotypic differences between representative vcG001 (isolate MI03) and vcG002 (isolate 2010-030 #91) isolates correspond to phenotypic differences in terms of virulence using both in vitro and in vivo approaches. In vitro infection of epithelioma papulosum cyprini (EPC), bluegill fry (BF-2), and Chinook salmon embryo (CHSE) cells demonstrated some differences in onset and rate of growth in EPC and BF-2 cells, without any difference in the quantity of RNA produced. In vivo infection of round gobies (Neogobius melanostomus) via immersion exposure to different concentrations of vcG001 or vcG002 caused a significantly greater mortality in round gobies exposed to 102 plaque forming units ml− 1 of vcG001. These experiments suggest that there are phenotypic differences between Great Lakes isolates of VHSV genotype IVb.

  16. Is it Worth Comparing Different Bankruptcy Models?

    Directory of Open Access Journals (Sweden)

    Miroslava Dolejšová

    2015-01-01

    Full Text Available The aim of this paper is to compare the performance of small enterprises in the Zlín and Olomouc Regions. These enterprises were assessed using the Altman Z-Score model, the IN05 model, the Zmijewski model and the Springate model. The batch selected for this analysis included 16 enterprises from the Zlín Region and 16 enterprises from the Olomouc Region. Financial statements subjected to the analysis are from 2006 and 2010. The statistical data analysis was performed using the one-sample z-test for proportions and the paired t-test. The outcomes of the evaluation run using the Altman Z-Score model, the IN05 model and the Springate model revealed the enterprises to be financially sound, but the Zmijewski model identified them as being insolvent. The one-sample z-test for proportions confirmed that at least 80% of these enterprises show a sound financial condition. A comparison of all models has emphasized the substantial difference produced by the Zmijewski model. The paired t-test showed that the financial performance of small enterprises had remained the same during the years involved. It is recommended that small enterprises assess their financial performance using two different bankruptcy models. They may wish to combine the Zmijewski model with any bankruptcy model (the Altman Z-Score model, the IN05 model or the Springate model to ensure a proper method of analysis.

  17. Constraining Cosmological Models with Different Observations

    Science.gov (United States)

    Wei, J. J.

    2016-07-01

    cosmological probes, perhaps even out to redshifts much greater (z≫2) than those accessible using SNe Ia. However, the currently available sample of SNe Ia is still quite small. Our simulations have shown that if SLSNe Ic can be commonly detected in the future, they have the potential of greatly refining the measurement of cosmological parameters, particularly the parameter w_{de} of the dark energy equation of state. In Chapter 3, we focus on GRB cosmology. We firstly use GRBs as standard candles in constructing the Hubble diagram at redshifts beyond the current reach of SNe Ia observations. Then we measure high-z star formation rate (SFR) using GRBs. We confirm that the latest Swift sample of GRBs reveals an increasing evolution in the GRB rate relative to SFR at high redshifts. The observed discrepancy between the GRB rate and the SFR may be eliminated by assuming a cosmic evolution in metallicity. Assuming that the SFR and GRB rate are related via an evolving metallicity, we find that the GRB data constrain the slope of the high-z SFR to be -2.41_{-2.09}^{+1.87}. In addition, first stars can only form in structures that are suitably dense, which can be parameterized by the minimum dark matter halo mass M_{min}. M_{min} must play an important role in star formation. We can constrain M_{min}systems, and carefully introduce how to constrain cosmological parameters using these important data. We find that both ΛCDM and the R_{h}=ct Universe account for the lens observations quite well, though the precision of these measurements does not appear to be good enough to favor one model over the other. In Chapters 5 and 6, we use measurements of the galaxy-cluster angular diameter distances and 32 age measurements of passively evolving galaxies to test and compare the standard model (ΛCDM) and the R_{h}=ct Universe, respectively. We show that both models appear to account for these two data very well. However, because of the different number of free parameters in these models, we

  18. Population growth rates of reef sharks with and without fishing on the great barrier reef: robust estimation with multiple models.

    Directory of Open Access Journals (Sweden)

    Mizue Hisano

    Full Text Available Overfishing of sharks is a global concern, with increasing numbers of species threatened by overfishing. For many sharks, both catch rates and underwater visual surveys have been criticized as indices of abundance. In this context, estimation of population trends using individual demographic rates provides an important alternative means of assessing population status. However, such estimates involve uncertainties that must be appropriately characterized to credibly and effectively inform conservation efforts and management. Incorporating uncertainties into population assessment is especially important when key demographic rates are obtained via indirect methods, as is often the case for mortality rates of marine organisms subject to fishing. Here, focusing on two reef shark species on the Great Barrier Reef, Australia, we estimated natural and total mortality rates using several indirect methods, and determined the population growth rates resulting from each. We used bootstrapping to quantify the uncertainty associated with each estimate, and to evaluate the extent of agreement between estimates. Multiple models produced highly concordant natural and total mortality rates, and associated population growth rates, once the uncertainties associated with the individual estimates were taken into account. Consensus estimates of natural and total population growth across multiple models support the hypothesis that these species are declining rapidly due to fishing, in contrast to conclusions previously drawn from catch rate trends. Moreover, quantitative projections of abundance differences on fished versus unfished reefs, based on the population growth rate estimates, are comparable to those found in previous studies using underwater visual surveys. These findings appear to justify management actions to substantially reduce the fishing mortality of reef sharks. They also highlight the potential utility of rigorously characterizing uncertainty, and

  19. [Soil organic carbon storage in different aged Larix gmelinii plantations in Great Xing' an Mountains of Northeast China].

    Science.gov (United States)

    Qi, Guang; Wang, Qing-Li; Wang, Xin-Chuang; Yu, Da-Pao; Zhou, Li; Zhou, Wang-Ming; Peng, Shun-Lei; Dai, Li-Min

    2013-01-01

    A sampling plot investigation was conducted to study the soil organic carbon (SOC) storage in 0-40 cm layer in 10-, 15-, 26- and 61 years old Larix gmelinii plantations in Great Xing' an Mountains of Northeast China as well as the temporal variation pattern of the SOC source/sink during the plantation management after the clear cutting of primary L. gmelinii forest. With the increasing age of the plantations, the SOC storage increased after an initial decrease, and the inflection point was at a stand age between 15- and 26-years old. Compared with that of primary forest, the SOC storage of the plantations played a role of carbon source at early stage (10-26 years old), but gradually transformed into carbon sink then, with a SOC storage of 158.91 t x hm(-2) in 61-year-old plantation. The SOC storage of the plantations increased with soil depth initially, but was higher in upper soil layer than in deeper soil layer after the stand age being 26, which implied that human disturbance had strong effects on the vertical distribution of SOC. It was considered that the appropriate cutting age for the L. gmelinii plantations in Great Xing' an Mountains could be at least 60 years old.

  20. Seasonal variation for the ratio of BaP to BeP at different sites in Great Xiamen Bay.

    Science.gov (United States)

    Wu, Shui-Ping; Qian, Ran-Ran; Lee, Tsung-Chang; Wang, Xing-Hong; Hong, Hua-Sheng; Yuan, Chung-Shin

    2012-04-01

    From March 2008 to February 2009, PM(10) samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) at eight sampling sites in Great Xiamen Bay, China. Analyses of the seasonal and spatial variations of these compounds revealed the following results. Significantly high levels of PAHs were found in the winter compared to the summer, sometimes exceeding 100 ng m(-3), and the spatial variations were influenced most by the sampling site surroundings. Composition profiles of PAHs of an urban and a rural site were shown to be very similar with a positive correlation coefficient larger than 0.9 at the 0.01 level of significance for the same season. Diagnostic ratios, together with principal component and multiple linear regression analysis, showed that more PAHs were from grass/wood/coal combustion in winter than in other seasons. The ratios of benzo[a]pyrene to benzo[e]pyrene (BaP-BeP) in winter and fall were 0.6-1.7 times higher than those in spring and summer, suggesting the importance of local emissions of PAHs. The BaP-BeP ratios in Kinmen were generally lower than those in Xiamen, indicating that the aging degree of PAHs was higher in Kinmen than in Xiamen. The external input of PAHs from upwind urban and industrial areas was one of the key factors causing high levels of PAHs in PM(10) in Great Xiamen Bay in winter.

  1. Summer hot snaps and winter conditions: modelling white syndrome outbreaks on Great Barrier Reef corals.

    Directory of Open Access Journals (Sweden)

    Scott F Heron

    Full Text Available Coral reefs are under increasing pressure in a changing climate, one such threat being more frequent and destructive outbreaks of coral diseases. Thermal stress from rising temperatures has been implicated as a causal factor in disease outbreaks observed on the Great Barrier Reef, Australia, and elsewhere in the world. Here, we examine seasonal effects of satellite-derived temperature on the abundance of coral diseases known as white syndromes on the Great Barrier Reef, considering both warm stress during summer and deviations from mean temperatures during the preceding winter. We found a high correlation (r(2 = 0.953 between summer warm thermal anomalies (Hot Snap and disease abundance during outbreak events. Inclusion of thermal conditions during the preceding winter revealed that a significant reduction in disease outbreaks occurred following especially cold winters (Cold Snap, potentially related to a reduction in pathogen loading. Furthermore, mild winters (i.e., neither excessively cool nor warm frequently preceded disease outbreaks. In contrast, disease outbreaks did not typically occur following warm winters, potentially because of increased disease resistance of the coral host. Understanding the balance between the effects of warm and cold winters on disease outbreak will be important in a warming climate. Combining the influence of winter and summer thermal effects resulted in an algorithm that yields both a Seasonal Outlook of disease risk at the conclusion of winter and near real-time monitoring of Outbreak Risk during summer. This satellite-derived system can provide coral reef managers with an assessment of risk three-to-six months in advance of the summer season that can then be refined using near-real-time summer observations. This system can enhance the capacity of managers to prepare for and respond to possible disease outbreaks and focus research efforts to increase understanding of environmental impacts on coral disease in

  2. Regional CO2 and latent heat surface fluxes in the Southern Great Plains: Measurements, modeling, and scaling

    Energy Technology Data Exchange (ETDEWEB)

    Riley, W. J.; Biraud, S.C.; Torn, M.S.; Fischer, M.L.; Billesbach, D.P.; Berry, J.A.

    2009-08-15

    Characterizing net ecosystem exchanges (NEE) of CO{sub 2} and sensible and latent heat fluxes in heterogeneous landscapes is difficult, yet critical given expected changes in climate and land use. We report here a measurement and modeling study designed to improve our understanding of surface to atmosphere gas exchanges under very heterogeneous land cover in the mostly agricultural U.S. Southern Great Plains (SGP). We combined three years of site-level, eddy covariance measurements in several of the dominant land cover types with regional-scale climate data from the distributed Mesonet stations and Next Generation Weather Radar precipitation measurements to calibrate a land surface model of trace gas and energy exchanges (isotope-enabled land surface model (ISOLSM)). Yearly variations in vegetation cover distributions were estimated from Moderate Resolution Imaging Spectroradiometer normalized difference vegetation index and compared to regional and subregional vegetation cover type estimates from the U.S. Department of Agriculture census. We first applied ISOLSM at a 250 m spatial scale to account for vegetation cover type and leaf area variations that occur on hundred meter scales. Because of computational constraints, we developed a subsampling scheme within 10 km 'macrocells' to perform these high-resolution simulations. We estimate that the Atmospheric Radiation Measurement Climate Research Facility SGP region net CO{sub 2} exchange with the local atmosphere was -240, -340, and -270 gC m{sup -2} yr{sup -1} (positive toward the atmosphere) in 2003, 2004, and 2005, respectively, with large seasonal variations. We also performed simulations using two scaling approaches at resolutions of 10, 30, 60, and 90 km. The scaling approach applied in current land surface models led to regional NEE biases of up to 50 and 20% in weekly and annual estimates, respectively. An important factor in causing these biases was the complex leaf area index (LAI) distribution

  3. Great Ideas Revisited. Techniques for Evaluating Training Programs. Revisiting Kirkpatrick's Four-Level Model.

    Science.gov (United States)

    Kirkpatrick, Donald

    1996-01-01

    Kirkpatrick reviews his 1959 article presenting his four-level model of evaluation. He suggests that training professionals should evaluate their programs and understanding those four levels is a good start. The text of the original article is included. (JOW)

  4. Comparing photo modeling methodologies and techniques: the instance of the Great Temple of Abu Simbel

    Directory of Open Access Journals (Sweden)

    Sergio Di Tondo

    2013-10-01

    Full Text Available After fifty years from the Salvage of the Abu Simbel Temples it has been possible to experiment the contemporary photo-modeling tools beginning from the original data of the photogrammetrical survey carried out in the 1950s. This produced a reflection on “Image Based” methods and modeling techniques, comparing strict 3d digital photogrammetry with the latest Structure From Motion (SFM systems. The topographic survey data, the original photogrammetric stereo couples, the points coordinates and their representation in contour lines, allowed to obtain a model of the monument in his configuration before the moving of the temples. The impossibility to carry out a direct survey led to touristic shots to create SFM models to use for geometric comparisons.

  5. Grassland and cropland net ecosystem production of the U.S. Great Plains: Regression tree model development and comparative analysis

    Science.gov (United States)

    Wylie, Bruce K.; Howard, Daniel; Dahal, Devendra; Gilmanov, Tagir; Ji, Lei; Zhang, Li; Smith, Kelcy

    2016-01-01

    This paper presents the methodology and results of two ecological-based net ecosystem production (NEP) regression tree models capable of up scaling measurements made at various flux tower sites throughout the U.S. Great Plains. Separate grassland and cropland NEP regression tree models were trained using various remote sensing data and other biogeophysical data, along with 15 flux towers contributing to the grassland model and 15 flux towers for the cropland model. The models yielded weekly mean daily grassland and cropland NEP maps of the U.S. Great Plains at 250 m resolution for 2000–2008. The grassland and cropland NEP maps were spatially summarized and statistically compared. The results of this study indicate that grassland and cropland ecosystems generally performed as weak net carbon (C) sinks, absorbing more C from the atmosphere than they released from 2000 to 2008. Grasslands demonstrated higher carbon sink potential (139 g C·m−2·year−1) than non-irrigated croplands. A closer look into the weekly time series reveals the C fluctuation through time and space for each land cover type.

  6. Grassland and Cropland Net Ecosystem Production of the U.S. Great Plains: Regression Tree Model Development and Comparative Analysis

    Directory of Open Access Journals (Sweden)

    Bruce Wylie

    2016-11-01

    Full Text Available This paper presents the methodology and results of two ecological-based net ecosystem production (NEP regression tree models capable of up scaling measurements made at various flux tower sites throughout the U.S. Great Plains. Separate grassland and cropland NEP regression tree models were trained using various remote sensing data and other biogeophysical data, along with 15 flux towers contributing to the grassland model and 15 flux towers for the cropland model. The models yielded weekly mean daily grassland and cropland NEP maps of the U.S. Great Plains at 250 m resolution for 2000–2008. The grassland and cropland NEP maps were spatially summarized and statistically compared. The results of this study indicate that grassland and cropland ecosystems generally performed as weak net carbon (C sinks, absorbing more C from the atmosphere than they released from 2000 to 2008. Grasslands demonstrated higher carbon sink potential (139 g C·m−2·year−1 than non-irrigated croplands. A closer look into the weekly time series reveals the C fluctuation through time and space for each land cover type.

  7. Great software debates

    CERN Document Server

    Davis, A

    2004-01-01

    The industry’s most outspoken and insightful critic explains how the software industry REALLY works. In Great Software Debates, Al Davis, shares what he has learned about the difference between the theory and the realities of business and encourages you to question and think about software engineering in ways that will help you succeed where others fail. In short, provocative essays, Davis fearlessly reveals the truth about process improvement, productivity, software quality, metrics, agile development, requirements documentation, modeling, software marketing and sales, empiricism, start-up financing, software research, requirements triage, software estimation, and entrepreneurship.

  8. Summer stream water temperature models for Great Lakes streams: New York

    Science.gov (United States)

    Murphy, Marilyn K.; McKenna, James E.; Butryn, Ryan S.; McDonald, Richard P.

    2010-01-01

    Temperature is one of the most important environmental influences on aquatic organisms. It is a primary driver of physiological rates and many abiotic processes. However, despite extensive research and measurements, synoptic estimates of water temperature are not available for most regions, limiting our ability to make systemwide and large-scale assessments of aquatic resources or estimates of aquatic species abundance and biodiversity. We used subwatershed averaging of point temperature measurements and associated multiscale landscape habitat conditions from over 3,300 lotic sites throughout New York State to develop and train artificial neural network models. Separate models predicting water temperature (in cold, cool, and warm temperature classes) within small catchment–stream order groups were developed for four modeling units, which together encompassed the entire state. Water temperature predictions were then made for each stream segment in the state. All models explained more than 90% of data variation. Elevation, riparian forest cover, landscape slope, and growing degree-days were among the most important model predictors of water temperature classes. Geological influences varied among regions. Predicted temperature distributions within stream networks displayed patterns of generally increasing temperature downstream but were patchy due to the averaging of water temperatures within stream size-classes of small drainages. Models predicted coldwater streams to be most numerous and warmwater streams to be generally associated with the largest rivers and relatively flat agricultural areas and urban areas. Model predictions provide a complete, georeferenced map of summer daytime mean stream temperature potential throughout New York State that can be used for planning and assessment at spatial scales from the stream segment class to the entire state.

  9. Long-term effect of different planting proportions on forest landscape in Great Xing'an Mountains, Northeast China after the catastrophic fire in 1987

    Institute of Scientific and Technical Information of China (English)

    WANG Xugao; LI Xiuzhen; HE Hongshi; XIE Fuju

    2007-01-01

    A landscape model(LANDIS)was used to study the long-term forest dynamics under five planting types (100% larch(P1);70% larch and 30% Mongolian Scotch pine(Pinus sylvestris var.mongolica)(P2);50% larch and 50% Mongolian Scotch pine(P3);30% larch and 70% Mongolian Scotch pine(P4),100% Mongolian Scotch pine (P5)),which were also employed in severely burned area under current planting intensity,and under natural regeneration(as a comparison)in Tuqiang Forest Bureau in the northern slopes of Great Xing'an Mountains after the catastrophic fire in 1987.Results showed that different planting types had a significant influence on the abundance of larch,Mongolian Scotch pine and white birch.The abundance of larch increased with time,whereas the abundance of Mongolian Scotch pine was in a converse way.The abundance of larch and Mongolian Scotch pine under these planting scenarios was higher than that under natural regeneration.Under these planting scenarios,the abundance of larch increased with the increasing proportion of larch,and the abundance of Mongolian Scotch pine was in a similar way.Contrary to larch and Mongolian Scotch pine,white birch had higher abundance under natural regeneration than that under these planting scenarios.Also,the different proportions of larch and Mongolian Scotch pine had an influence on the abundance of white birch.White birch had higher abundance with the increasing proportion of Mongolian Scotch pine.As for the total abundance of larch and Mongolian Scotch pine,the difference was not significant under P2,P3 and P4 scenarios,but was higher than that under P1 and P5 scenarios,which indicated that individual-species planting should not be used in the forest landscape.

  10. Comparing Sediment Yield Predictions from Different Hydrologic Modeling Schemes

    Science.gov (United States)

    Dahl, T. A.; Kendall, A. D.; Hyndman, D. W.

    2015-12-01

    Sediment yield, or the delivery of sediment from the landscape to a river, is a difficult process to accurately model. It is primarily a function of hydrology and climate, but influenced by landcover and the underlying soils. These additional factors make it much more difficult to accurately model than water flow alone. It is not intuitive what impact different hydrologic modeling schemes may have on the prediction of sediment yield. Here, two implementations of the Modified Universal Soil Loss Equation (MUSLE) are compared to examine the effects of hydrologic model choice. Both the Soil and Water Assessment Tool (SWAT) and the Landscape Hydrology Model (LHM) utilize the MUSLE for calculating sediment yield. SWAT is a lumped parameter hydrologic model developed by the USDA, which is commonly used for predicting sediment yield. LHM is a fully distributed hydrologic model developed primarily for integrated surface and groundwater studies at the watershed to regional scale. SWAT and LHM models were developed and tested for two large, adjacent watersheds in the Great Lakes region; the Maumee River and the St. Joseph River. The models were run using a variety of single model and ensemble downscaled climate change scenarios from the Coupled Model Intercomparison Project 5 (CMIP5). The initial results of this comparison are discussed here.

  11. Cyberinfrastructure for remote environmental observatories: a model homogeneous sensor network in the Great Basin, USA

    Science.gov (United States)

    Strachan, Scotty; Slater, David; Fritzinger, Eric; Lyles, Bradley; Kent, Graham; Smith, Kenneth; Dascalu, Sergiu; Harris, Frederick

    2017-04-01

    Sensor-based data collection has changed the potential scale and resolution of in-situ environmental studies by orders of magnitude, increasing expertise and management requirements accordingly. Cost-effective management of these observing systems is possible by leveraging cyberinfrastructure resources. Presented is a case study environmental observation network in the Great Basin region, USA, the Nevada Climate-ecohydrological Assessment Network (NevCAN). NevCAN stretches hundreds of kilometers across several mountain ranges and monitors climate and ecohydrological conditions from low desert (900 m ASL) to high subalpine treeline (3360 m ASL) down to 1-minute timescales. The network has been operating continuously since 2010, collecting billions of sensor data points and millions of camera images that record hourly conditions at each site, despite requiring relatively low annual maintenance expenditure. These data have provided unique insight into fine-scale processes across mountain gradients, which is crucial scientific information for a water-scarce region. The key to maintaining data continuity for these remotely-located study sites has been use of uniform data transport and management systems, coupled with high-reliability power system designs. Enabling non-proprietary digital communication paths to all study sites and sensors allows the research team to acquire data in near-real-time, troubleshoot problems, and diversify sensor hardware. A wide-area network design based on common Internet Protocols (IP) has been extended into each study site, providing production bandwidth of between 2 Mbps and 60 Mbps, depending on local conditions. The network architecture and site-level support systems (such as power generation) have been implemented with the core objectives of capacity, redundancy, and modularity. NevCAN demonstrates that by following simple but uniform "best practices", the next generation of regionally-specific environmental observatories can evolve to

  12. Child Poverty During the Years of the Great Recession: An Analysis of Racial Differences Among Immigrants and US Natives

    Science.gov (United States)

    Tucker, Catherine

    2015-01-01

    Although the consequences of the Great Recession are extensively discussed in previous research, three critical issue need to be addressed in order to develop a full portrait of the economic experiences of children during this period. First, given the changing immigrant composition of the US child population, new studies are needed for examining the implications of immigrant status for exposure to child poverty during the recession. Second, it is important to understand how traditional patterns of racial inequality among were transformed during the years of the recession. Finally, it is not clear whether recession-related changes in socioeconomic inequalities continued to have implications for child well-being in the post-recession period. Results from this analysis indicate that the adverse effects of the recession were most intense in states with significant changes in their populations of Black and Latino immigrant children. The results further show that declines in parental work opportunities were more consequential for poverty among Whites and Asians. The analysis also finds differential implications of family contexts for child poverty among Black immigrant and natives during the recession. Finally, the results indicate that increases in racial child poverty disparities during the recession did not disappear in the years following the downturn. PMID:26918063

  13. Making Culverts Great Again: Modeling Road Culvert Vulnerability to Assist Prioritization of Local Infrastructure Investment

    Science.gov (United States)

    Gold, D.; Walter, M. T.; Watkins, L.; Kaufman, Z.; Meyer, A.; Mahaney, M.

    2016-12-01

    The concurrent threats posed by climate change and aging infrastructure have become of increasing concern in recent years. In the Northeastern US, storms such as Hurricane Irene and Super Storm Sandy have highlighted the vulnerability of infrastructure to extreme weather events, which are projected to become more frequent under future climate change scenarios. Road culverts are one type of infrastructure that is particularly vulnerable to such threats. Culverts allow roads to safely traverse small streams or drainage ditches, and their proper design is critical to ensuring a safe and reliable transportation network. Much of the responsibility for designing and maintaining road culverts lies at the local level, but many local governments lack the resources to quantify the vulnerability of their culverts to major storms. This study contributes a model designed to assist local governments in rapidly assessing the vulnerability of large numbers of culverts and identifies common characteristics of vulnerable culverts. Model inputs include culvert geometry and location data collected by trained local field teams. The model uses custom tools created in ArcGIS and Python to determine the maximum return period storm that each culvert can safely convey under current and projected future rainfall regimes. As a demonstration, over 1000 culverts in New York State were modeled. It was found that a significant percentage of modeled culverts failed to convey the current 5 year return period storm event (deemed a failure) and this percentage increased under projected future rainfall conditions. The model results were analyzed to determine correlations between culvert characteristics and failure. Characteristics investigated included watershed size, road type (state, county or local), affluence of the surrounding area and suitability for aquatic organism passage. Results from this study can be used by local governments to quantify and characterize the vulnerability of current

  14. Developing Critical Loads of acidity for streams in the Great Smoky Mountains National Park, using PnET-BGC model

    Science.gov (United States)

    Fakhraei, H.

    2015-12-01

    Acid deposition has impaired acid-sensitive streams and reduced aquatic biotic integrity in Great Smoky Mountains National Park (GRSM) by decreasing pH and acid neutralizing capacity (ANC). Twelve streams in GRSM are listed by the state of Tennessee as impaired due to low stream pH (pHdeposition. Calibrating 30 stream-watersheds in GRSM (including 12 listed impaired streams) to the long-term stream chemistry observations, the model was parameterized for the Park. The calibrated model was used to evaluate the level of atmospheric deposition above which harmful effects occur, known as "critical loads", for individual study watersheds. Estimated critical loads and exceedances (levels of deposition above the critical load) of atmospheric sulfur and nitrogen deposition were depicted through geographic information system maps. Accuracy of model simulations in the presence of uncertainties in the estimated model parameters and inputs was assessed using three uncertainty and sensitivity techniques.

  15. [Thurstone model application to difference sensory tests].

    Science.gov (United States)

    Angulo, Ofelia; O'Mahony, Michael

    2009-12-01

    Part of understanding why judges perform better on some difference tests than others requires an understanding of how information coming from the mouth to the brain is processed. For some tests it is processed more efficiently than others. This is described by what has been called Thurstonian modeling. This brief review introduces the concepts and ideas involved in Thurstonian modeling as applied to sensory difference measurement. It summarizes the literature concerned with the theorizing and confirmation of Thurstonian models. It introduces the important concept of stimulus variability and the fundamental measure of sensory difference: d'. It indicates how the paradox of discriminatory non-discriminators, which had puzzled researchers for years, can be simply explained using the model. It considers how memory effects and the complex interactions in the mouth can reduce d' by increasing the variance of sensory distributions.

  16. Great Expectations

    NARCIS (Netherlands)

    Dickens, Charles

    2005-01-01

    One of Dickens's most renowned and enjoyable novels, Great Expectations tells the story of Pip, an orphan boy who wishes to transcend his humble origins and finds himself unexpectedly given the opportunity to live a life of wealth and respectability. Over the course of the tale, in which Pip

  17. Great Concern

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    Women of China magazine was first published in 1956. When the "cultural revolution" started in 1966 the magazine was obliged to stop publication. In 1979, when the magazine resumed publication, Mme. Soong Ching Ling, late vice chairperson of the National People’s Congress, wrote her congratulations—"Congratulations and Great Expectation."

  18. Great Expectations

    NARCIS (Netherlands)

    Dickens, Charles

    2005-01-01

    One of Dickens's most renowned and enjoyable novels, Great Expectations tells the story of Pip, an orphan boy who wishes to transcend his humble origins and finds himself unexpectedly given the opportunity to live a life of wealth and respectability. Over the course of the tale, in which Pip encount

  19. Great Comets

    Science.gov (United States)

    Burnham, Robert

    2000-05-01

    Spectacular and mysterious objects that come and go in the night sky, comets have dwelt in our popular culture for untold ages. As remnants from the formation of the Solar system, they are objects of key scientific research and space missions. As one of nature's most potent and dramatic dangers, they pose a threat to our safety--and yet they were the origin of our oceans and perhaps even life itself. This beautifully illustrated book tells the story of the biggest and most awe-inspiring of all comets: those that have earned the title "Great." Robert Burnham focuses on the Great comets Hyakutake in 1996 and Hale-Bopp in 1997, which gripped attention worldwide because, for many, they were the first comets ever seen. He places these two recent comets in the context of their predecessors from past ages, among them the famous Comet Halley. Great Comets explains the exciting new discoveries that have come from these magnificent objects and profiles the spaceprobes to comets due for launch in the next few years. The book even takes a peek behind Hollywood's science-fiction fantasies to assess the real risks humanity faces from potential impacts of both comets and asteroids. For everyone interested in astronomy, this exciting book reveals the secrets of the Great Comets and provides essential tools for keeping up to date with comet discoveries in the future. Robert Burnham has been an amateur astronomer since the mid-1950s. He has been a senior editor of Astronomy magazine (1986-88) and is the author of many books and CD-ROMS, including Comet Hale-Bopp: Find and Enjoy the Great Comet and Comet Explorer.

  20. Screw placement of pedicle of vertebral arch-pay great attention to segmental differences of the pedicle

    Institute of Scientific and Technical Information of China (English)

    殷渠东; 郑祖根; 董启榕; 唐平

    2002-01-01

    Objective: To investigate appropriate ways for screw placement of pedicle of vertebral arch in the horizontal plane.Methods: Fifteen preserved thoracolumbar spine specimens (T11-L5) were used and divided into three groups at random. Firstly four anatomic parameters indicating screw positions in the horizontal plane were measured. Secondly the methods of Roy-camille, Magerl, and authors segmental differences were used to place successively the screws of the pedicles with 5 mm, 6 mm, and 7 mm in diameter. Coincidences between the drilling point, drilling direction and pedicle axis, and ruptures of the pedicle as well as the length of the screw in the vertebral body were observed. Results: Four anatomic parameters at various segments showed significant differences (P <0.05). The drilling point by the Roy-camilles method deviated medial to pedicle axis in most segments, and its drilling direction did not coincide well with most E-angles of the pedicles. The drilling point by Magerls method coincided relatively well with pedicle axis in lumbar vertebrae, but there were still some differences between its drilling direction and E-angles of the pedicles. The method of segmental differences coincided the best with the pedicle axis. The lengths of screw in the vertebra were relatively long by both Magerl and segmental difference methods. When 5 mm diametral screw was used by the three methods, the rupture rate was very low. When 6 mm and 7 mm diametral screws were placed, the rupture rate was accordingly increased. Of the three methods, Roy-camilles method showed a relatively high rupture rate, while the method of segmental differences a comparatively low rupture rate. Various degrees of rupture of the pedicle of vertebral arch were found at the juncture of the thoracic and lumbar vertebrae when 6 mm or 7 mm diametral screws was used by any screw placement method. In contrast, the rupture was seldom seen at the lower lumbar vertebrae when 7 mm diametral screws

  1. Screw placement of pedicle of vertebral arch—pay great attention to segmental differences of the pedicle

    Institute of Scientific and Technical Information of China (English)

    殷渠东; 郑祖根; 等

    2002-01-01

    Objective:To investigate appropriate ways for screw placement of pedicle of vertebral arch in the horizontal plane.Methods:Fifteen prreserved thoracolunbar spine specimens(T11-L5)were used and divided into three groups at random.Firstly four anatomic parameters indicating screw positions in the horizontal plae were measured.Secondly the methods of Roy-camille,Magerl,and authors'segmental differences were used to place successively the scews of the pedicles with 5mm,6mm,and7mm in diameter.Coincidences between the drilling point,drilling direction and pedicle axis,and ruptures of the pedicle as well as the length of the screw in the vertebral body were observed.Results:Four anatomic parameters at various segments showed significant differences(P<0.05),The drilling point by the Roy-camille's method deviated medial to pedicle axis in most segments,and its drilling direction did not coincide well with most E-angles of the pedicles.The drilling point by Magerl's method coincided relatively well with pedicle axis in lumbar vertebrae,but there were still some differences between its drilling direction and E-angles of the pedicles.The method of segmental differemces coincided the best with the pedicle axis.The lengths of screw in the vertebra were relatively long by blth Magerl and segmental difference methods.When5mm diametral screw was used by the three methods,the rupture rate wsa very low.When 6mmand7mm diametral screws were placed,the rupture rate was accordingly increased.Of the three methods.Roy-camille's method showed a relatively high rupture rate,while the method of segmental differences a comparatively low rupture rate.Various degrees of rupture of the pedicle of vertebral arch were found at the juncture of the thoracic and lunbar vertebrae when6mmor7mm diametral screws was used by any screw placement method.In contrast,the rupture was seldom seen at the lower lumbar vertebrae when 7mm diametral screws were used.Conclusions:The segmental difference methodis

  2. Tides and lake-level variations in the great Patagonian lakes: Observations, modelling and geophysical implications.

    Science.gov (United States)

    Marderwald, Eric; Richter, Andreas; Horwath, Martin; Hormaechea, Jose Luis; Groh, Andreas

    2016-04-01

    In Patagonia, the glacial-isostatic adjustment (GIA) to past ice-mass changes (Ivins & James 2004; Klemann et al. 2007) is of particular interest in the context of the determination of the complex regional rheology related to plate subduction in a triple-junction constellation. To further complicate the situation, GIA is overlaid with load deformation not only due to present ice mass changes but also due to water-level changes in the lakes surrounding the icefields and the ocean surrounding Patagonia. These elastic deformations affect the determination of glacial-isostatic uplift rates from GPS observations (Dietrich et al. 2010; Lange et al. 2014). Observations of lake tides and their comparison with the theoretical tidal signal have been used previously to validate predictions of ocean tidal loading and have revealed regional deviations from conventional global elastic earth models (Richter et al. 2009). In this work we investigate the tides and lake-level variations in Lago Argentino, Lago Viedma, Lago San Martín/O'Higgins and Lago Buenos Aires/General Carrera. This allows us to test, among other things, the validity of tidal loading models. We present pressure tide-gauge records from two sites in Lago Argentino extending over 2.5 years (Richter et al. 2015). These observations are complemented by lake-level records provided by the Argentine National Hydrometeorological Network. Based on these lake-level time series the principal processes affecting the lake level are identified and quantified. Lake-level changes reflecting variations in lake volume are dominated by a seasonal cycle exceeding 1 m in amplitude. Lake-volume changes occur in addition with a daily period in response to melt water influx from surrounding glaciers. In Lago Argentino sporadic lake-volume jumps are caused by bursting of the ice dam of Perito Moreno glacier. Water movements in these lakes are dominated by surface seiches reaching 20 cm in amplitude. A harmonic tidal analysis of the lake

  3. A Paddock to reef monitoring and modelling framework for the Great Barrier Reef: Paddock and catchment component.

    Science.gov (United States)

    Carroll, Chris; Waters, David; Vardy, Suzanne; Silburn, David M; Attard, Steve; Thorburn, Peter J; Davis, Aaron M; Halpin, Neil; Schmidt, Michael; Wilson, Bruce; Clark, Andrew

    2012-01-01

    Targets for improvements in water quality entering the Great Barrier Reef (GBR) have been set through the Reef Water Quality Protection Plan (Reef Plan). To measure and report on progress towards the targets set a program has been established that combines monitoring and modelling at paddock through to catchment and reef scales; the Paddock to Reef Integrated Monitoring, Modelling and Reporting Program (Paddock to Reef Program). This program aims to provide evidence of links between land management activities, water quality and reef health. Five lines of evidence are used: the effectiveness of management practices to improve water quality; the prevalence of management practice adoption and change in catchment indicators; long-term monitoring of catchment water quality; paddock & catchment modelling to provide a relative assessment of progress towards meeting targets; and finally marine monitoring of GBR water quality and reef ecosystem health. This paper outlines the first four lines of evidence.

  4. Dietary acrylamide intake of adults in the European Prospective Investigation into Cancer and Nutrition differs greatly according to geographical region

    NARCIS (Netherlands)

    Freisling, Heinz; Moskal, Aurelie; Ferrari, Pietro; Nicolas, Genevieve; Knaze, Viktoria; Clavel-Chapelon, Francoise; Boutron-Ruault, Marie-Christine; Nailler, Laura; Teucher, Birgit; Grote, Verena A.; Boeing, Heiner; Clemens, Matthias; Tjonneland, Anne; Olsen, Anja; Overvad, Kim; Ramon Quiros, J.; Duell, Eric J.; Sanchez, Maria-Jose; Amiano, Pilar; Chirlaque, Maria-Dolores; Barricarte, Aurelio; Khaw, Kay-Tee; Wareham, Nicholas J.; Crowe, Francesca L.; Gallo, Valentina; Oikonomou, Eleni; Naska, Androniki; Trichopoulou, Antonia; Palli, Domenico; Agnoli, Claudia; Tumino, Rosario; Polidoro, Silvia; Mattiello, Amalia; Bueno-de-Mesquita, H. Bas; Ocke, Marga C.; Peeters, Petra H. M.; Wirfalt, Elisabet; Ericson, Ulrika; Bergdahl, Ingvar A.; Johansson, Ingegerd; Hjartaker, Anette; Engeset, Dagrun; Skeie, Guri; Riboli, Elio; Slimani, Nadia

    2013-01-01

    Methodological differences in assessing dietary acrylamide (AA) often hamper comparisons of intake across populations. Our aim was to describe the mean dietary AA intake in 27 centers of 10 European countries according to selected lifestyle characteristics and its contributing food sources in the Eu

  5. Great Expectations for "Great Expectations."

    Science.gov (United States)

    Ridley, Cheryl

    Designed to make the study of Dickens'"Great Expectations" an appealing and worthwhile experience, this paper presents a unit of study intended to help students gain (1) an appreciation of Dickens' skill at creating realistic human characters; (2) an insight into the problems of a young man confused by false values and unreal ambitions and ways to…

  6. Comparison of methods for measuring viable E. coli cells during cultivation: great differences in the early and late exponential growth phases.

    Science.gov (United States)

    Wang, Hengwei; Cheng, Hairong; Wei, Dongzhi; Wang, Fengqing

    2011-01-01

    Four methods, namely enumeration of colony-forming units (CFU), aerobic respiration, MTT reduction capacity and succinate dehydrogenase activity were compared to determine the viability of E. coli cells at the early and late exponential growth phases. Our results revealed that great differences in cell viability existed between these methods and that the choice of method to determine cell viability must be made with caution.

  7. An energy-circuit population model for great egrets (Ardea alba) at Lake Okeechobee, Florida, U.S.A

    Science.gov (United States)

    Smith, Jeff P.

    1997-01-01

    I simulated the annual population cycles of Great Egrets (Ardea alba) at Lake Okeechobee, Florida, to provide a framework for evaluating the local population dynamics of nesting and foraging wading birds. The external forcing functions were solar energy, minimum air temperature, water depth, surface-water drying rate, and season. Solar input controlled the production of prey at moderate to high lake stages, but water area exerted primary control during a two-year drought. Modeling prey production as a linear function of water area resulted in underestimation of prey density during the drought, suggesting that prey organisms maintained high fecundity while concentrated in submerged vegetation at the lakeward fringe of the littoral zone. Simulation confirmed that large influxes of wading birds during the drought were the combined result of a regional refuge response and the availability of concentrated prey. Modeling immigration and emigration as primarily functions of the surface-water drying rate, rather than lake stage, resulted in a closer match of observed and simulated population trends for foraging birds, suggesting that the pattern of surface-water fluctuations was a more important factor than water depth. Simulation indicated an abrupt-threshold response rather than a linear association between foraging efficiency and low temperatures, which reduce activity levels of forage fishes. Great Egret breeder recruitment is primarily a function of prey availability, climate, and hydrologic trends, but simulation confirmed the concurrent involvement of a seasonal or physiological-readiness factor. An attractor function driven by high winter lake stages was necessary to reproduce observed patterns of breeder recruitment, suggesting that Great Egrets initiate nesting based on environmental cues that lead to peak food availability when nestlings are present. Poor correspondence of reproductive effort and nest productivity suggested that the drought compromised the birds

  8. "Great expectations" of adoptive parents: theory extension through structural equation modeling.

    Science.gov (United States)

    Foli, Karen J; Lim, Eunjung; South, Susan C; Sands, Laura P

    2014-01-01

    Most of the 2 million adoptive parents in the United States make the transition to parenting successfully. Adoptive parents who do not make the transition easily may put their children at risk for negative outcomes. The aim of this study was to further refine Foli's midrange theory of postadoption depression, which postulates that fulfillment of expectations is a principal contributor to parental emotional health status, aggravation, and bonding. The linked dataset (National Survey of Children's Health and National Survey of Adoptive Parents) was used for structural equation modeling. The sample consisted of 1,426 parents with adopted children who had been placed in the home more than 2 years before survey completion. Special services and child's behaviors were direct determinants of parental expectations, and parental expectations were direct determinants of parental aggravation and parentalbonding. As anticipated, parental expectations served as a mediator between child-related variables and parental outcomes. A path was also found between child's behaviors and special services and parental emotional health status. Child's past trauma was also associated with parental bonding. Parental expectations showed direct relationships with the latent variables of parental aggravation and bonding. Future research should examine factors associated with early transition when children have been in the adoptive home less than 2 years and include specific expectations held by parents.

  9. Laurentian Great Lakes phytoplankton and their water quality characteristics, including a diatom-based model for paleoreconstruction of phosphorus.

    Directory of Open Access Journals (Sweden)

    Euan D Reavie

    Full Text Available Recent shifts in water quality and food web characteristics driven by anthropogenic impacts on the Laurentian Great Lakes warranted an examination of pelagic primary producers as tracers of environmental change. The distributions of the 263 common phytoplankton taxa were related to water quality variables to determine taxon-specific responses that may be useful in indicator models. A detailed checklist of taxa and their environmental optima are provided. Multivariate analyses indicated a strong relationship between total phosphorus (TP and patterns in the diatom assemblages across the Great Lakes. Of the 118 common diatom taxa, 90 (76% had a directional response along the TP gradient. We further evaluated a diatom-based transfer function for TP based on the weighted-average abundance of taxa, assuming unimodal distributions along the TP gradient. The r(2 between observed and inferred TP in the training dataset was 0.79. Substantial spatial and environmental autocorrelation within the training set of samples justified the need for further model validation. A randomization procedure indicated that the actual transfer function consistently performed better than functions based on reshuffled environmental data. Further, TP was minimally confounded by other environmental variables, as indicated by the relatively large amount of unique variance in the diatoms explained by TP. We demonstrated the effectiveness of the transfer function by hindcasting TP concentrations using fossil diatom assemblages in a Lake Superior sediment core. Passive, multivariate analysis of the fossil samples against the training set indicated that phosphorus was a strong determinant of historical diatom assemblages, verifying that the transfer function was suited to reconstruct past TP in Lake Superior. Collectively, these results showed that phytoplankton coefficients for water quality can be robust indicators of Great Lakes pelagic condition. The diatom-based transfer

  10. Great unexpected differences between two populations of the intertidal crab Neohelice granulata inhabiting close but contrasting habitats (Crustacea: Decapoda: Brachyura

    Directory of Open Access Journals (Sweden)

    Eduardo D. Spivak

    Full Text Available ABSTRACT Two populations of the Southwestern Atlantic burrowing crab, Neohelice granulata (Dana, 1851, are separated by only 190 km. They inhabit bays that drain into a Patagonian gulf in the southernmost limit of the geographical distribution of the species: San Antonio Bay (SAO and San José Gulf (RSJ. The population from SAO has been extensively studied, whereas that of RSJ has not. The main goal of this study is to compare the ecological and habitat characteristics of the two populations, based on samples collected on successive days during the middle of the reproductive season of the crab. The substrate of SAO is composed of a high proportion of gravel and scarce organic matter, whereas the substrate of RSJ presents twice as much silt and clay, and greater organic matter content. Crabs of both sexes were larger at RSJ. Fecundity and reproductive output were greater at RSJ. The size of females at maturity was smaller and their range was shorter at RSJ. Burrows were longer and wider at RSJ. Our results indicate that there are strong differences between the two populations, which might be correlated with local environmental differences, mainly substrate granulometry and food availability.

  11. Great Lakes

    Science.gov (United States)

    Edsall, Thomas A.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

    1998-01-01

    The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside the floodplain of the river. The region spans about 9º of latitude and 20º of longitude and lies roughly halfway between the equator and the North Pole in a lowland corridor that extends from the Gulf of Mexico to the Arctic Ocean.The Great Lakes are the most prominent natural feature of the region (Fig. 1). They have a combined surface area of about 245,000 square kilometers and are among the largest, deepest lakes in the world. They are the largest single aggregation of fresh water on the planet (excluding the polar ice caps) and are the only glacial feature on Earth visible from the surface of the moon (The Nature Conservancy 1994a).The Great Lakes moderate the region’s climate, which presently ranges from subarctic in the north to humid continental warm in the south (Fig. 2), reflecting the movement of major weather masses from the north and south (U.S. Department of the Interior 1970; Eichenlaub 1979). The lakes act as heat sinks in summer and heat sources in winter and are major reservoirs that help humidify much of the region. They also create local precipitation belts in areas where air masses are pushed across the lakes by prevailing winds, pick up moisture from the lake surface, and then drop that moisture over land on the other side of the lake. The mean annual frost-free period—a general measure of the growing-season length for plants and some cold-blooded animals—varies from 60 days at higher elevations in the north to 160 days in lakeshore areas in the south. The climate influences the general distribution of wild plants and animals in the region and also influences the activities and distribution of the human

  12. Korarchaeota diversity, biogeography, and abundance in Yellowstone and Great Basin hot springs and ecological niche modeling based on machine learning.

    Science.gov (United States)

    Miller-Coleman, Robin L; Dodsworth, Jeremy A; Ross, Christian A; Shock, Everett L; Williams, Amanda J; Hartnett, Hilairy E; McDonald, Austin I; Havig, Jeff R; Hedlund, Brian P

    2012-01-01

    Over 100 hot spring sediment samples were collected from 28 sites in 12 areas/regions, while recording as many coincident geochemical properties as feasible (>60 analytes). PCR was used to screen samples for Korarchaeota 16S rRNA genes. Over 500 Korarchaeota 16S rRNA genes were screened by RFLP analysis and 90 were sequenced, resulting in identification of novel Korarchaeota phylotypes and exclusive geographical variants. Korarchaeota diversity was low, as in other terrestrial geothermal systems, suggesting a marine origin for Korarchaeota with subsequent niche-invasion into terrestrial systems. Korarchaeota endemism is consistent with endemism of other terrestrial thermophiles and supports the existence of dispersal barriers. Korarchaeota were found predominantly in >55°C springs at pH 4.7-8.5 at concentrations up to 6.6×10(6) 16S rRNA gene copies g(-1) wet sediment. In Yellowstone National Park (YNP), Korarchaeota were most abundant in springs with a pH range of 5.7 to 7.0. High sulfate concentrations suggest these fluids are influenced by contributions from hydrothermal vapors that may be neutralized to some extent by mixing with water from deep geothermal sources or meteoric water. In the Great Basin (GB), Korarchaeota were most abundant at spring sources of pH<7.2 with high particulate C content and high alkalinity, which are likely to be buffered by the carbonic acid system. It is therefore likely that at least two different geological mechanisms in YNP and GB springs create the neutral to mildly acidic pH that is optimal for Korarchaeota. A classification support vector machine (C-SVM) trained on single analytes, two analyte combinations, or vectors from non-metric multidimensional scaling models was able to predict springs as Korarchaeota-optimal or sub-optimal habitats with accuracies up to 95%. To our knowledge, this is the most extensive analysis of the geochemical habitat of any high-level microbial taxon and the first application of a C-SVM to

  13. Korarchaeota diversity, biogeography, and abundance in Yellowstone and Great Basin hot springs and ecological niche modeling based on machine learning.

    Directory of Open Access Journals (Sweden)

    Robin L Miller-Coleman

    Full Text Available Over 100 hot spring sediment samples were collected from 28 sites in 12 areas/regions, while recording as many coincident geochemical properties as feasible (>60 analytes. PCR was used to screen samples for Korarchaeota 16S rRNA genes. Over 500 Korarchaeota 16S rRNA genes were screened by RFLP analysis and 90 were sequenced, resulting in identification of novel Korarchaeota phylotypes and exclusive geographical variants. Korarchaeota diversity was low, as in other terrestrial geothermal systems, suggesting a marine origin for Korarchaeota with subsequent niche-invasion into terrestrial systems. Korarchaeota endemism is consistent with endemism of other terrestrial thermophiles and supports the existence of dispersal barriers. Korarchaeota were found predominantly in >55°C springs at pH 4.7-8.5 at concentrations up to 6.6×10(6 16S rRNA gene copies g(-1 wet sediment. In Yellowstone National Park (YNP, Korarchaeota were most abundant in springs with a pH range of 5.7 to 7.0. High sulfate concentrations suggest these fluids are influenced by contributions from hydrothermal vapors that may be neutralized to some extent by mixing with water from deep geothermal sources or meteoric water. In the Great Basin (GB, Korarchaeota were most abundant at spring sources of pH<7.2 with high particulate C content and high alkalinity, which are likely to be buffered by the carbonic acid system. It is therefore likely that at least two different geological mechanisms in YNP and GB springs create the neutral to mildly acidic pH that is optimal for Korarchaeota. A classification support vector machine (C-SVM trained on single analytes, two analyte combinations, or vectors from non-metric multidimensional scaling models was able to predict springs as Korarchaeota-optimal or sub-optimal habitats with accuracies up to 95%. To our knowledge, this is the most extensive analysis of the geochemical habitat of any high-level microbial taxon and the first application of a C

  14. Growth-Prediction Model for Blue Mussels (Mytilus edulis on Future Optimally Thinned Farm-Ropes in Great Belt (Denmark

    Directory of Open Access Journals (Sweden)

    Poul S. Larsen

    2016-07-01

    Full Text Available A recently developed BioEnergetic Growth (BEG model for blue mussels (Mytilus edulis, valid for juvenile mussels, has been further developed to an ‘extended model’ and an alternative ‘ad hoc BEG model’ valid for post-metamorphic mussels, where the latter accounts for changing ambient chl a concentration. It was used to predict the growth of M. edulis on optimally thinned farm-ropes in Great Belt (Denmark, from newly settled post-metamorphic mussels of an initial shell size of 0.8 mm to marketable juvenile 30–35 mm ‘mini-mussels’. Such mussels will presumably in the near future be introduced as a new Danish, smaller-sized consumer product. Field data for actual growth (from Day 0 = 14 June 2011 showed that size of ‘mini-mussel’ was reached on Day 109 (Oct 1 and length 38 mm on Day 178 (Dec 9 while the corresponding predictions using the extended model were Day 121 (Oct 13 and Day 159 (Nov 20. Similar results were obtained by use of the ad hoc BEG model which also demonstrated the sensitivity of growth prediction to levels of chl a concentration, but less to temperature. The results suggest that it is possible (when the conditions are optimal, i.e., no intraspecific competition ensured by sufficient thinning to produce ‘mini-mussels’ in Great Belt during one season, but not the usual marketable 45-mm mussels. We suggest that the prediction model may be used as a practical instrument to evaluate to what degree the actual growth of mussels on farm ropes due to intraspecific competition may deviate from the potential (optimal growth under specified chl a and temperature conditions, and this implies that the effect of thinning to optimize the individual growth by eliminating intraspecific competition can be rationally evaluated.

  15. The Model of Unification and the Model of Diversification of Public School Teachers' Continuing Professional Development in Great Britain, Canada and the USA

    Science.gov (United States)

    Mukan, Nataliya; Myskiv, Iryna; Kravets, Svitlana

    2016-01-01

    In the article the theoretical framework of public school teachers' continuing professional development (CPD) in Great Britain, Canada and the USA has been presented. The main objectives have been defined as theoretical analysis of scientific and pedagogical literature, which highlights different aspects of the problem under research; presentation…

  16. Biodiversity and species-environment relationships of the demersal fish assemblage at the Great Meteor Seamount (subtropical NE Atlantic), sampled by different trawls

    DEFF Research Database (Denmark)

    Fock, H.; Uiblein, F.; Köster, Fritz

    2002-01-01

    Quantitative data collected with different bottom trawls at the Great Meteor Scamount (subtropical NE Atlantic, 30degreesN; 28.5degreesW) in 1967, 1970 and 1998 are compared. Bootstrap estimates of total catch per unit effort increased from 6.96 and 10.8 ind. m(-1) h(-1) in 1967 and 1970, respect......Quantitative data collected with different bottom trawls at the Great Meteor Scamount (subtropical NE Atlantic, 30degreesN; 28.5degreesW) in 1967, 1970 and 1998 are compared. Bootstrap estimates of total catch per unit effort increased from 6.96 and 10.8 ind. m(-1) h(-1) in 1967 and 1970...... information, a grand total of 46 species was found associated with the Great Meteor Seamount. Diversity was higher in 1967 and 1970 (Shannon's diversity: H'=2.5 and 1.6) than in 1998 (H'=0.9). Species-environment relationships are discussed in terms of a sound-scattering layer-interception hypothesis, i...

  17. A coupled biophysical model for the distribution of the great scallop Pecten maximus in the English Channel

    Science.gov (United States)

    Le Goff, Clément; Lavaud, Romain; Cugier, Philippe; Jean, Fred; Flye-Sainte-Marie, Jonathan; Foucher, Eric; Desroy, Nicolas; Fifas, Spyros; Foveau, Aurélie

    2017-03-01

    In this paper we used a modelling approach integrating both physical and biological constraints to understand the biogeographical distribution of the great scallop Pecten maximus in the English Channel during its whole life cycle. A 3D bio-hydrodynamical model (ECO-MARS3D) providing environmental conditions was coupled to (i) a population dynamics model and (ii) an individual ecophysiological model (Dynamic Energy Budget model). We performed the coupling sequentially, which underlined the respective role of biological and physical factors in defining P. maximus distribution in the English Channel. Results show that larval dispersion by hydrodynamics explains most of the scallop distribution and enlighten the main known hotspots for the population, basically corresponding to the main fishing areas. The mechanistic description of individual bioenergetics shows that food availability and temperature control growth and reproduction and explain how populations may maintain themselves in particular locations. This last coupling leads to more realistic densities and distributions of adults in the English Channel. The results of this study improves our knowledge on the stock and distribution dynamics of P. maximus, and provides grounds for useful tools to support management strategies.

  18. Comparison of two different modelling tools

    DEFF Research Database (Denmark)

    Brix, Wiebke; Elmegaard, Brian

    2009-01-01

    In this paper a test case is solved using two different modelling tools, Engineering Equation Solver (EES) and WinDali, in order to compare the tools. The system of equations solved, is a static model of an evaporator used for refrigeration. The evaporator consists of two parallel channels......, and it is investigated how a non-uniform airflow influences the refrigerant mass flow rate distribution and the total cooling capacity of the heat exchanger. It is shown that the cooling capacity decreases significantly with increasing maldistribution of the airflow. Comparing the two simulation tools it is found...

  19. Great Ellipse Route Planning Based on Space Vector

    Directory of Open Access Journals (Sweden)

    LIU Wenchao

    2015-07-01

    Full Text Available Aiming at the problem of navigation error caused by unified earth model in great circle route planning using sphere model and modern navigation equipment using ellipsoid mode, a method of great ellipse route planning based on space vector is studied. By using space vector algebra method, the vertex of great ellipse is solved directly, and description of great ellipse based on major-axis vector and minor-axis vector is presented. Then calculation formulas of great ellipse azimuth and distance are deduced using two basic vectors. Finally, algorithms of great ellipse route planning are studied, especially equal distance route planning algorithm based on Newton-Raphson(N-R method. Comparative examples show that the difference of route planning between great circle and great ellipse is significant, using algorithms of great ellipse route planning can eliminate the navigation error caused by the great circle route planning, and effectively improve the accuracy of navigation calculation.

  20. Seasonal patterns in growth, blood consumption, and effects on hosts by parasitic-phase sea lampreys in the Great Lakes: an individual-based model approach

    Science.gov (United States)

    Madenjian, Charles P.; Cochran, Philip A.; Bergstedt, Roger A.

    2003-01-01

    An individual-based model (IBM) was developed for sea lamprey (Petromyzon marinus) populations in the Laurentian Great Lakes. The IBM was then calibrated to observed growth, by season, for sea lampreys in northern Lake Huron under two different water temperature regimes: a regime experienced by Seneca-strain lake trout (Salvelinus namaycush) and a regime experienced by Marquettestrain lake trout. Modeling results indicated that seasonal blood consumption under the Seneca regime was very similar to that under the Marquette regime. Simulated mortality of lake trout directly due to blood removal by sea lampreys occurred at nearly twice the rate during August and September under the Marquette regime than under the Seneca regime. However, cumulative sea lamprey-induced mortality on lake trout over the entire duration of the sea lamprey's parasitic phase was only 7% higher for the Marquette regime compared with the Seneca regime. Thus, these modeling results indicated that the strain composition of the host (lake trout) population was not important in determining total number of lake trout deaths or total blood consumption attributable to the sea lamprey population, given the sea lamprey growth pattern. Regardless of water temperature regime, both blood consumption rate by sea lampreys and rate of sea lamprey-induced mortality on lake trout peaked in late October. Elevated blood consumption in late October appeared to be unrelated to changes in water temperature. The IBM approach should prove useful in optimizing control of sea lampreys in the Laurentian Great Lakes.

  1. Numerical modeling of tides in the Great Bay Estuarine System: dynamical balance and spring-neap residual modulation

    Science.gov (United States)

    McLaughlin, J. W.; Bilgili, A.; Lynch, D. R.

    2003-05-01

    The Great Bay Estuarine System, in New Hampshire, USA, has been the focus area for an attempt to develop a robust finite element method model for estuarine hydrodynamics. Past studies used a nonlinear, time stepping, kinematic model with limited success (Ip et al. Advances in fluid mechanics III, WIT, Southampton (2000) 569; Bilgili et al. J. Geophys. Res. - Oceans 107 (2002); Ertürk et al. Estuar. Coast. Shelf Sci. 47 (1998) 119). We add dynamic physics (that is, local accelerations) for deep-water areas and keep kinematic physics (that is, without local and advective accelerations), with the inclusion of a porous medium beneath the open channel, for shallow and dewatering areas. The choice of which physics set to apply is made on an elemental depth dependent basis. The addition of the local acceleration terms for deep-water areas is seen to greatly improve accuracy in matching of tidal phasing over previous studies. Simulations involving M 2/M 4/M 6 tidal constituents result in strong agreement to observed data from the 1975 Great Bay field program (Swift & Brown, Estuar. Coast. Shelf Sci. 17 (1983) 297), in terms of both tidal heights and cross-section averaged velocities. Comparisons with 10 tidal elevation observation stations and four cross-section averaged current transects show good agreement, displaying average normalized root mean square misfit values of 0.08 and 0.25, respectively. Study of the simulated momentum balance shows the size of the contributions from acceleration terms to be on the order of a third the size of the contributions from the pressure gradient and bottom stress terms. Although relatively small, they are observed to peak at the crucial time of tidal reversal. Application of the model for long-term simulation using an M 2/N 2/S 2 forcing shows the ability to realistically capture the spring-neap cycle. The tidally rectified flow is generally described as a constant spatial pattern with overall amplitude modulation following the

  2. Modeling of STATCOM under different loading conditions

    DEFF Research Database (Denmark)

    George, G.J.; Ramachandran, Rakesh; Kowsalya, M.

    2012-01-01

    This paper deals with the study and analysis of Flexible AC Transmission Systems (FACTS), mainly the modeling of STATCOM. Reactive Power Compensation plays a very important role in the transmission of Electric Power. A comparative study of how the reactive power is injected into the transmission ...... system with and without STATCOM under different loading condition is also illustrated in this paper. Simulations are performed using MATLAB/SIMULINK software. © 2012 IEEE....

  3. Comparison of Different Mathematical Models of Cavitation

    Directory of Open Access Journals (Sweden)

    Dorota HOMA

    2014-12-01

    Full Text Available Cavitation occurs during the flow when local pressure drops to the saturation pressure according to the temperature of the flow. It includes both evaporation and condensation of the vapor bubbles, which occur alternately with high frequency. Cavitation can be very dangerous, especially for pumps, because it leads to break of flow continuity, noise, vibration, erosion of blades and change in pump’s characteristics. Therefore it is very important for pump designers and users to avoid working in cavitation conditions. Simulation of flow can be very useful in that and can indicate if there is risk of cavitating flow occurrence. As this is a multiphase flow and quite complicated phenomena, there are a few mathematical models describing it. The aim of this paper is to make a short review of them and describe their approach to model cavitation. It is desirable to know differences between them to model this phenomenon properly.

  4. Modelling sulfamethoxazole degradation under different redox conditions

    Science.gov (United States)

    Sanchez-Vila, X.; Rodriguez-Escales, P.

    2015-12-01

    Sulfamethoxazole (SMX) is a low adsorptive, polar, sulfonamide antibiotic, widely present in aquatic environments. Degradation of SMX in subsurface porous media is spatially and temporally variable, depending on various environmental factors such as in situ redox potential, availability of nutrients, local soil characteristics, and temperature. It has been reported that SMX is better degraded under anoxic conditions and by co-metabolism processes. In this work, we first develop a conceptual model of degradation of SMX under different redox conditions (denitrification and iron reducing conditions), and second, we construct a mathematical model that allows reproducing different experiments of SMX degradation reported in the literature. The conceptual model focuses on the molecular behavior and contemplates the formation of different metabolites. The model was validated using the experimental data from Barbieri et al. (2012) and Mohatt et al. (2011). It adequately reproduces the reversible degradation of SMX under the presence of nitrite as an intermediate product of denitrification. In those experiments degradation was mediated by the transient formation of a diazonium cation, which was considered responsible of the substitution of the amine radical by a nitro radical, forming the 4-nitro-SMX. The formation of this metabolite is a reversible process, so that once the concentration of nitrite was back to zero due to further advancement of denitrification, the concentration of SMX was fully recovered. The forward reaction, formation of 4-nitro SMX, was modeled considering a kinetic of second order, whereas the backward reaction, dissociation of 4-nitro-SMX back to the original compound, could be modeled with a first order degradation reaction. Regarding the iron conditions, SMX was degraded due to the oxidation of iron (Fe2+), which was previously oxidized from goethite due to the degradation of a pool of labile organic carbon. As the oxidation of iron occurred on the

  5. Developing Remote Sensing Products for Monitoring and Modeling Great Lakes Coastal Wetland Vulnerability to Climate Change and Land Use

    Science.gov (United States)

    Bourgeau-Chavez, L. L.; Miller, M. E.; Battaglia, M.; Banda, E.; Endres, S.; Currie, W. S.; Elgersma, K. J.; French, N. H. F.; Goldberg, D. E.; Hyndman, D. W.

    2014-12-01

    Spread of invasive plant species in the coastal wetlands of the Great Lakes is degrading wetland habitat, decreasing biodiversity, and decreasing ecosystem services. An understanding of the mechanisms of invasion is crucial to gaining control of this growing threat. To better understand the effects of land use and climatic drivers on the vulnerability of coastal zones to invasion, as well as to develop an understanding of the mechanisms of invasion, research is being conducted that integrates field studies, process-based ecosystem and hydrological models, and remote sensing. Spatial data from remote sensing is needed to parameterize the hydrological model and to test the outputs of the linked models. We will present several new remote sensing products that are providing important physiological, biochemical, and landscape information to parameterize and verify models. This includes a novel hybrid radar-optical technique to delineate stands of invasives, as well as natural wetland cover types; using radar to map seasonally inundated areas not hydrologically connected; and developing new algorithms to estimate leaf area index (LAI) using Landsat. A coastal map delineating wetland types including monocultures of the invaders (Typha spp. and Phragmites austrailis) was created using satellite radar (ALOS PALSAR, 20 m resolution) and optical data (Landsat 5, 30 m resolution) fusion from multiple dates in a Random Forests classifier. These maps provide verification of the integrated model showing areas at high risk of invasion. For parameterizing the hydrological model, maps of seasonal wetness are being developed using spring (wet) imagery and differencing that with summer (dry) imagery to detect the seasonally wet areas. Finally, development of LAI remote sensing high resolution algorithms for uplands and wetlands is underway. LAI algorithms for wetlands have not been previously developed due to the difficulty of a water background. These products are being used to

  6. Comparison of Different Fuel Temperature Models

    Energy Technology Data Exchange (ETDEWEB)

    Weddig, Beatrice

    2003-02-01

    The purpose of this work is to improve the performance of the core calculation system used in Ringhals for in-core fuel management. It has been observed that, whereas the codes yield results that are in good agreement with measurements when the core operates at full nominal power, this agreement deteriorates noticeably when the reactor is running at reduced power. This deficiency of the code system was observed by comparing the calculated and measured boron concentrations in the moderator of the PWR. From the neutronic point of view, the difference between full power and reduced power in the same core is the different temperature of the fuel and the moderator. Whereas the coolant temperature can be measured and is thus relatively well known, the fuel temperature is only inferred from the moderator temperature as well as neutron physics and heat transfer calculations. The most likely reason for the above mentioned discrepancy is therefore the uncertainty of the fuel temperature at low power, and hence the incorrect calculation of the fuel temperature reactivity feedback through the so called Doppler effect. To obtain the fuel temperature at low power, usually some semi-empirical relations, sometimes called correlations, are used. The above-mentioned inaccuracy of the core calculation procedures can thus be tracked down to the insufficiency of these correlations. Therefore, the suggestion is that the above mentioned deficiency of the core calculation codes can be eliminated or reduced if the fuel temperature correlations are improved. An improved model, called the 30% model, is implemented in SIMULATE-3, the core calculation code used at Ringhals. The accuracy of the 30% model was compared to that of the present model by considering a number of cases, where measured values of the boron concentration at low power were available, and comparing them with calculated values using both the present and the new model. It was found that on the whole, the new fuel temperature

  7. Modeling Storm Surge and Inundation in Washington, DC, during Hurricane Isabel and the 1936 Potomac River Great Flood

    Directory of Open Access Journals (Sweden)

    Harry V. Wang

    2015-07-01

    Full Text Available Washington, DC, the capital of the U.S., is located along the Upper Tidal Potomac River, where a reliable operational model is needed for making predictions of storm surge and river-induced flooding. We set up a finite volume model using a semi-implicit, Eulerian-Lagrangian scheme on a base grid (200 m and a special feature of sub-grids (10 m, sourced with high-resolution LiDAR data and bathymetry surveys. The model domain starts at the fall line and extends 120 km downstream to Colonial Beach, VA. The model was used to simulate storm tides during the 2003 Hurricane Isabel. The water level measuring 3.1 m reached the upper tidal river in the vicinity of Washington during the peak of the storm, followed by second and third flood peaks two and four days later, resulting from river flooding coming downstream after heavy precipitation in the watershed. The modeled water level and timing were accurate in matching with the verified peak observations within 9 cm and 3 cm, and with R2 equal to 0.93 and 0.98 at the Wisconsin Avenue and Washington gauges, respectively. A simulation was also conducted for reconstructing the historical 1936 Potomac River Great Flood that inundated downtown. It was identified that the flood water, with a velocity exceeding 2.7 m/s in the downstream of Roosevelt Island, pinched through the bank northwest of East Potomac Park near DC. The modeled maximum inundation extents revealed a crescent-shaped flooding area, which was consistent with the historical surveyed flood map of the event.

  8. The WRF Model Forecast-Derived Low-Level Wind Shear Climatology over the United States Great Plains

    Directory of Open Access Journals (Sweden)

    Sukanta Basu

    2010-02-01

    Full Text Available For wind resource assessment projects, it is common practice to use a power-law relationship (U(z ~ zα and a fixed shear exponent (α = 1=7 to extrapolate the observed wind speed from a low measurement level to high turbine hub-heights. However, recent studies using tall-tower observations have found that the annual average shear exponents at several locations over the United States Great Plains (USGP are significantly higher than 1=7. These findings highlight the critical need for detailed spatio-temporal characterizations of wind shear climatology over the USGP, where numerous large wind farms will be constructed in the foreseeable future. In this paper, a new generation numerical weather prediction model—the Weather Research and Forecasting (WRF model, a fast and relatively inexpensive alternative to time-consuming and costly tall-tower projects, is utilized to determine whether it can reliably estimate the shear exponent and the magnitude of the directional shear at any arbitrary location over the USGP. Our results indicate that the WRF model qualitatively captures several low-level wind shear characteristics. However, there is definitely room for physics parameterization improvements for the WRF model to reliably represent the lower part of the atmospheric boundary layer.

  9. Mental Models, Magical Thinking, And Individual Differences

    Directory of Open Access Journals (Sweden)

    Phil Turner

    2009-01-01

    Full Text Available Broadly, there are two mutually exclusive accounts of how people (non-specialist users reason about and conceptualize interactive technology. The first is based on classical cognitive psychology and is characterized by the term mental model. The second, drawing on concepts from social cognition, observes that people often anthropomorphize technology. We argue that people are able to exhibit both of these quite different styles of cognition, which Baron-Cohen has described as systemizing and empathizing. The former is associated with the drive to analyze, explore, and construct a system, whereas the latter is the ability to spontaneously tune into another’s thoughts and feelings. The propensity to systemize might give rise to a mental model, while the empathizing tendency might tend to anthropomorphize technology. We present an empirical study that lends support for the above position.

  10. DIFFERENT MODELS OF HEPATOTOXICITY AND RELATED LIVER DISEASES: A REVIEW

    Directory of Open Access Journals (Sweden)

    Singh Robin

    2012-07-01

    Full Text Available The liver is among the most complex and important organs in the human body. Its primary function is to control the flow and safety of substances absorbed from the digestive system before distribution of these substances to the systemic circulatory system. Hepatotoxicity implies chemical-driven liver damage. Chemicals that cause liver injury are called hepatotoxins. Hepatic injury leads to disturbances in transport function of hepatocytes resulting in leakage of plasma membrane thereby causing an increased enzyme level in serum. There are many diseases that are related with hepatotoxicity caused by certain chemicals or hepatotoxins. Herbal medicines are great demand in various chemicals and drugs disordered hepatic, the developed world for primary health care because of their efficacy, safety, lesser side effects and narrow therapeutic window. This review focus on liver, its function, liver diseases and different models of hepatotoxicity.

  11. Sex differences in developmental programming models.

    Science.gov (United States)

    Aiken, Catherine E; Ozanne, Susan E

    2013-01-01

    The theory of developmental programming suggests that diseases such as the metabolic syndrome may be 'programmed' by exposure to adverse stimuli during early development. The developmental programming literature encompasses the study of a wide range of suboptimal intrauterine environments in a variety of species and correlates these with diverse phenotypic outcomes in the offspring. At a molecular level, a large number of variables have been measured and suggested as the basis of the programmed phenotype. The range of both dependent and independent variables studied often makes the developmental programming literature complex to interpret and the drawing of definitive conclusions difficult. A common, though under-explored, theme of many developmental programming models is a sex difference in offspring outcomes. This holds true across a range of interventions, including dietary, hypoxic, and surgical models. The molecular and phenotypic outcomes of adverse in utero conditions are often more prominent in male than female offspring, although there is little consideration given to the basis for this observation in most studies. We review the evidence that maternal energy investment in male and female conceptuses may not be equal and may be environment dependent. It is suggested that male and female development could be viewed as separate processes from the time of conception, with differences in both timing and outcomes.

  12. Growth-Prediction Model for Blue Mussels (Mytilus edulis) on Future Optimally Thinned Farm-Ropes in Great Belt (Denmark)

    DEFF Research Database (Denmark)

    Larsen, Poul Scheel; Riisgård, Hans

    2016-01-01

    A recently developed BioEnergetic Growth (BEG) model for blue mussels (Mytilus edulis), valid for juvenile mussels, has been further developed to an ‘extended model’ and an alternative ‘ad hoc BEG model’ valid for post-metamorphic mussels, where the latter accounts for changing ambient chl...... a concentration. It was used to predict the growth of M. edulis on optimally thinned farm-ropes in Great Belt (Denmark), from newly settled post-metamorphic mussels of an initial shell size of 0.8 mm to marketable juvenile 30–35 mm ‘mini-mussels’. Such mussels will presumably in the near future be introduced...... as a new Danish, smaller-sized consumer product. Field data for actual growth (from Day 0 = 14 June 2011) showed that size of ‘mini-mussel’ was reached on Day 109 (Oct 1) and length 38 mm on Day 178 (Dec 9) while the corresponding predictions using the extended model were Day 121 (Oct 13) and Day 159 (Nov...

  13. Use of remote-sensing reflectance to constrain a data assimilating marine biogeochemical model of the Great Barrier Reef

    Science.gov (United States)

    Jones, Emlyn M.; Baird, Mark E.; Mongin, Mathieu; Parslow, John; Skerratt, Jenny; Lovell, Jenny; Margvelashvili, Nugzar; Matear, Richard J.; Wild-Allen, Karen; Robson, Barbara; Rizwi, Farhan; Oke, Peter; King, Edward; Schroeder, Thomas; Steven, Andy; Taylor, John

    2016-12-01

    Skillful marine biogeochemical (BGC) models are required to understand a range of coastal and global phenomena such as changes in nitrogen and carbon cycles. The refinement of BGC models through the assimilation of variables calculated from observed in-water inherent optical properties (IOPs), such as phytoplankton absorption, is problematic. Empirically derived relationships between IOPs and variables such as chlorophyll-a concentration (Chl a), total suspended solids (TSS) and coloured dissolved organic matter (CDOM) have been shown to have errors that can exceed 100 % of the observed quantity. These errors are greatest in shallow coastal regions, such as the Great Barrier Reef (GBR), due to the additional signal from bottom reflectance. Rather than assimilate quantities calculated using IOP algorithms, this study demonstrates the advantages of assimilating quantities calculated directly from the less error-prone satellite remote-sensing reflectance (RSR). To assimilate the observed RSR, we use an in-water optical model to produce an equivalent simulated RSR and calculate the mismatch between the observed and simulated quantities to constrain the BGC model with a deterministic ensemble Kalman filter (DEnKF). The traditional assumption that simulated surface Chl a is equivalent to the remotely sensed OC3M estimate of Chl a resulted in a forecast error of approximately 75 %. We show this error can be halved by instead using simulated RSR to constrain the model via the assimilation system. When the analysis and forecast fields from the RSR-based assimilation system are compared with the non-assimilating model, a comparison against independent in situ observations of Chl a, TSS and dissolved inorganic nutrients (NO3, NH4 and DIP) showed that errors are reduced by up to 90 %. In all cases, the assimilation system improves the simulation compared to the non-assimilating model. Our approach allows for the incorporation of vast quantities of remote-sensing observations

  14. Artificial neural network models as a useful tool to forecast human thermal comfort using microclimatic and bioclimatic data in the great Athens area (Greece).

    Science.gov (United States)

    Moustris, Kostas P; Tsiros, Ioannis X; Ziomas, Ioannis C; Paliatsos, Athanasios G

    2010-01-01

    The present study deals with the development and application of Artificial Neural Network (ANN) models as a tool for the evaluation of human thermal comfort conditions in the urban environment. ANNs are applied to forecast for three consecutive days during the hot period of the year (May-September) the human thermal comfort conditions as well as the daily number of consecutive hours with high levels of thermal discomfort in the great area of Athens (Greece). Modeling was based on bioclimatic data calculated by two widely used biometereorogical indices (the Discomfort Index and the Cooling Power Index) and microclimatic data (air temperature, relative humidity and wind speed) from 7 different meteorological stations for the period 2001-2005. Model performance showed that the risk of human discomfort conditions exceeding certain thresholds can be successfully forecasted by the ANN models. In addition, despite the limitations of the models, the results of the study demonstrated that ANNs, when adequately trained, could have a high applicability in the area of prevention human thermal discomfort levels in urban areas, based on a series of relatively limited number of bioclimatic data values calculated prior to the period of interest.

  15. Fatty acid profiles of great tit ( Parus major) eggs differ between urban and rural habitats, but not between coniferous and deciduous forests

    Science.gov (United States)

    Toledo, Alejandra; Andersson, Martin N.; Wang, Hong-Lei; Salmón, Pablo; Watson, Hannah; Burdge, Graham C.; Isaksson, Caroline

    2016-08-01

    Early-life nutrition is an important determinant of both short- and long-term performance and fitness. The avian embryo develops within an enclosed package of nutrients, of which fatty acids (FA) are essential for many aspects of development. The FA composition of yolk depends on maternal nutrition and condition prior to egg formation, which may be affected by the external environment. To test if maternal environment affects yolk FA composition, we investigated whether the FA composition of great tit ( Parus major) egg yolks differed between urban and rural habitats, and between deciduous and coniferous habitats. The results reveal differences in FA composition between eggs laid in urban and rural habitats, but not between eggs from the coniferous and deciduous habitats. To a large extent, this difference likely reflects dietary differences associated with urban habitats rather than dominating vegetation type. Specifically, urban yolks contained lower proportions of both ω-3 and ω-6 polyunsaturated FAs (PUFA), which are important for chick development. We also found a positive association between the proportion of saturated fatty acids and laying date, and a negative association between the proportion of ω-6 PUFA and clutch size. Given that urbanization is expanding rapidly, future studies should investigate whether factors such as anthropogenic food in the urban environment underlie these differences and whether they impair chick development.

  16. Fatty acid profiles of great tit (Parus major) eggs differ between urban and rural habitats, but not between coniferous and deciduous forests.

    Science.gov (United States)

    Toledo, Alejandra; Andersson, Martin N; Wang, Hong-Lei; Salmón, Pablo; Watson, Hannah; Burdge, Graham C; Isaksson, Caroline

    2016-08-01

    Early-life nutrition is an important determinant of both short- and long-term performance and fitness. The avian embryo develops within an enclosed package of nutrients, of which fatty acids (FA) are essential for many aspects of development. The FA composition of yolk depends on maternal nutrition and condition prior to egg formation, which may be affected by the external environment. To test if maternal environment affects yolk FA composition, we investigated whether the FA composition of great tit (Parus major) egg yolks differed between urban and rural habitats, and between deciduous and coniferous habitats. The results reveal differences in FA composition between eggs laid in urban and rural habitats, but not between eggs from the coniferous and deciduous habitats. To a large extent, this difference likely reflects dietary differences associated with urban habitats rather than dominating vegetation type. Specifically, urban yolks contained lower proportions of both ω-3 and ω-6 polyunsaturated FAs (PUFA), which are important for chick development. We also found a positive association between the proportion of saturated fatty acids and laying date, and a negative association between the proportion of ω-6 PUFA and clutch size. Given that urbanization is expanding rapidly, future studies should investigate whether factors such as anthropogenic food in the urban environment underlie these differences and whether they impair chick development.

  17. A population model of the impact of a rodenticide containing strychnine on Great Basin Gophersnakes (Pituophis catenifer deserticola).

    Science.gov (United States)

    Bishop, Christine A; Williams, Kathleen E; Kirk, David A; Nantel, Patrick; Reed, Eric; Elliott, John E

    2016-09-01

    Strychnine is a neurotoxin and an active ingredient in some rodenticides which are placed in burrows to suppress pocket gopher (Thomomys talpoides) populations in range and crop land in western North America. The population level impact was modelled of the use of strychnine-based rodenticides on a non-target snake species, the Great Basin Gophersnake (Pituophis catenifer deserticola), which is a predator of pocket gopher and a Species at Risk in Canada. Using information on population density, demographics, and movement and habitat suitability for the Gophersnake living in an agricultural valley in BC, Canada, we estimated the impact of the poisoning of adult snakes on the long-term population size. To determine the area where Gophersnakes could be exposed to strychnine, we used vendor records of a rodenticide, and quantified the landcover areas of orchards and vineyards where the compound was most commonly applied. GIS analysis determined the areas of overlap between those agricultural lands and suitable habitats used by Gophersnakes. Stage-based population matrix models revealed that in a low density (0.1/ha) population scenario, a diet of one pocket gopher per year wherein 10 % of them carried enough strychnine to kill an adult snake could cause the loss of 2 females annually from the population and this would reduce the population by 35.3 % in 25 years. Under the same dietary exposure, up to 35 females could die per year in a high density (0.4/ha) population which would result in a loss of 50 % of adults in 25 years.

  18. Do great teams think alike? An examination of team mental models and their impact on team performance.

    Science.gov (United States)

    Gardner, Aimee K; Scott, Daniel J; AbdelFattah, Kareem R

    2017-05-01

    Team mental models represent the shared understanding of team members within their relevant environment. Thus, team mental models should have a substantial impact on a team's ability to engage in purposeful and coordinated action. We sought to examine the impact of shared team mental models on team performance and to investigate if team mental models increase over time as teams continue to work together. New surgery interns were assigned randomly to 1 of 10 teams. Each team participated in one unique simulation every day for 5 days, each followed by video-based debriefing with a facilitator. Participants also completed independently a concept similarity tool validated previously in nonmedical team literature to assess team mental models. All performances were video recorded and evaluated with a scenario-specific team performance tool by a single, blinded junior surgeon under an institutional review board-approved protocol. Changes in performance and team mental models over time were assessed with paired samples t tests. Regression analysis was used to examine the extent to which team mental models predicted team performance. Thirty interns (age 27; 77% men) participated in the training program. Percentage of items achieved (x¯ ± SD) on the performance evaluation was 39 ± 20, 51 ± 14, 22 ± 17, 63 ± 14, and 77 ± 25 for Days 1-5, respectively. Team mental models were 30 ± 5, 28 ± 6, 27 ± 8, 26 ± 7, and 25 ± 6 for Days 1-5 respectively, such that larger values corresponded to greater differences in team mental models. Paired sample t tests indicated that both average performance and team mental models similarity improved from the first to last day (P team mental models predicted team performance on Days 2-5 (all P team mental models among the teams leads to better team performance. Additionally, the increase in team mental models over time suggests that engaging in team-based simulation may catalyze the process by which surgery

  19. A Comparison of Different Machine Transliteration Models

    CERN Document Server

    Choi, K; Oh, J; 10.1613/jair.1999

    2011-01-01

    Machine transliteration is a method for automatically converting words in one language into phonetically equivalent ones in another language. Machine transliteration plays an important role in natural language applications such as information retrieval and machine translation, especially for handling proper nouns and technical terms. Four machine transliteration models -- grapheme-based transliteration model, phoneme-based transliteration model, hybrid transliteration model, and correspondence-based transliteration model -- have been proposed by several researchers. To date, however, there has been little research on a framework in which multiple transliteration models can operate simultaneously. Furthermore, there has been no comparison of the four models within the same framework and using the same data. We addressed these problems by 1) modeling the four models within the same framework, 2) comparing them under the same conditions, and 3) developing a way to improve machine transliteration through this com...

  20. Differences in vulnerability to traumatic stress among patients with psychiatric disorders: One-year follow-up study after the Great East Japan Earthquake.

    Science.gov (United States)

    Inoue, Kana; Inoue, Koju; Suda, Shiro; Shioda, Katsutoshi; Kobayashi, Toshiyuki; Kishi, Koichiro; Kato, Satoshi

    2015-09-01

    The aim of this study was to evaluate differences in vulnerability to traumatic stress and the 1-year course of post-traumatic stress symptoms among patients with pre-existing psychiatric disorders after the Great East Japan Earthquake. The Impact of Event Scale-Revised (IES-R) was used to assess post-traumatic stress symptoms in 612 patients with schizophrenic (ICD-10 F2; n = 163), mood (F3; n = 299), or neurotic disorders (F4; n = 150) at 1-4 months and again at 13-16 months after the disaster (retention rate: 68%). The mean IES-R total score for all diagnostic groups was 18.6 at index and 13.4 at follow up. The mean IES-R total score for patients with neurotic disorders (22.5) was significantly higher than that of patients with mood disorders (18.1) and schizophrenic disorders (15.9). At follow up, these scores decreased for all groups and inter-group differences were not observed. Vulnerability to traumatic stress after a disaster was most severe in patients with neurotic disorders, followed by mood disorders, and, lastly, schizophrenic disorders. This difference among the three diagnostic groups was not found 1 year after the disaster. © 2015 The Authors. Psychiatry and Clinical Neurosciences © 2015 Japanese Society of Psychiatry and Neurology.

  1. Differences in demographic traits of four butterflyfish species between two reefs of the Great Barrier Reef separated by 1,200 km

    Science.gov (United States)

    Berumen, M. L.; Trip, E. D. L.; Pratchett, M. S.; Choat, J. H.

    2012-03-01

    Many species demonstrate variation in life history attributes in response to gradients in environmental conditions. For fishes, major drivers of life history variation are changes in temperature and food availability. This study examined large-scale variation in the demography of four species of butterflyfishes ( Chaetodon citrinellus, Chaetodon lunulatus, Chaetodon melannotus, and Chaetodon trifascialis) between two locations on Australia's Great Barrier Reef (Lizard Island and One Tree Island, separated by approximately 1,200 km). Variation in age-based demographic parameters was assessed using the re-parameterised von Bertalanffy growth function. All species displayed measurable differences in body size between locations, with individuals achieving a larger adult size at the higher latitude site (One Tree Island) for three of the four species examined. Resources and abundances of the study species were also measured, revealing some significant differences between locations. For example, for C. trifascialis, there was no difference in its preferred resource or in abundance between locations, yet it achieved a larger body size at the higher latitude location, suggesting a response to temperature. For some species, resources and abundances did vary between locations, limiting the ability to distinguish between a demographic response to temperature as opposed to a response to food or competition. Future studies of life histories and demographics at large spatial scales will need to consider the potentially confounding roles of temperature, resource usage and availability, and abundance/competition to disentangle the effects of these environmental variables.

  2. Differences in demographic traits of four butterflyfish species between two reefs of the Great Barrier Reef separated by 1,200 km

    KAUST Repository

    Berumen, Michael L.

    2011-11-16

    Many species demonstrate variation in life history attributes in response to gradients in environmental conditions. For fishes, major drivers of life history variation are changes in temperature and food availability. This study examined large-scale variation in the demography of four species of butterflyfishes (Chaetodon citrinellus, Chaetodon lunulatus, Chaetodon melannotus, and Chaetodon trifascialis) between two locations on Australia\\'s Great Barrier Reef (Lizard Island and One Tree Island, separated by approximately 1,200 km). Variation in age-based demographic parameters was assessed using the re-parameterised von Bertalanffy growth function. All species displayed measurable differences in body size between locations, with individuals achieving a larger adult size at the higher latitude site (One Tree Island) for three of the four species examined. Resources and abundances of the study species were also measured, revealing some significant differences between locations. For example, for C. trifascialis, there was no difference in its preferred resource or in abundance between locations, yet it achieved a larger body size at the higher latitude location, suggesting a response to temperature. For some species, resources and abundances did vary between locations, limiting the ability to distinguish between a demographic response to temperature as opposed to a response to food or competition. Future studies of life histories and demographics at large spatial scales will need to consider the potentially confounding roles of temperature, resource usage and availability, and abundance/competition to disentangle the effects of these environmental variables. © 2011 Springer-Verlag.

  3. Great Zimbabwe's water

    DEFF Research Database (Denmark)

    Pikirayi, Innocent; Sulas, Federica; Musindo, Tendai Treddah

    2016-01-01

    in the region's well-watered granite hills and valleys, and culminating in a vast urban and trading society. Later, c.1550 AD, it is argued, drying climate, land overexploitation, and changing regional trading patterns would lead to the decline of Great Zimbabwe. A review of this model is necessary since Great...... Zimbabwe and communities living around it survive in a region constantly threatened by water crises. However, we still know very little on the forms and uses of water and how these have influenced its development and demise. This article offers a multilayered review of available information on water......, including new records on environmental sequences, modern water sources, and provisioning models from in and around Great Zimbabwe. The integration of both old and new datasets allows us to follow the history of people-water interaction from early times to the present. We argue that understanding...

  4. Modeling enterococcus densities measured by quantitative polymerase chain reaction and membrane filtration using environmental conditions at four Great Lakes beaches

    Science.gov (United States)

    Data collected by the US Environmental Protection Agency (EPA) during the summer months of 2003 and 2004 at four US Great Lakes beaches were analyzed using regression analysis to identify relationships between meteorological, physical water characteristics, and beach characterist...

  5. Comparison of Different Surgical Treatment for Varicosis of Great Saphenous Vein%大隐静脉曲张不同手术治疗方法比较

    Institute of Scientific and Technical Information of China (English)

    彭利武; 周恩湘; 唐华; 文星均

    2011-01-01

    目的:探讨大隐静脉高位结扎加腔内激光治疗大隐静脉曲张的临床意义.方法:150例大隐静脉曲张患者分为A、B两组,其中A组70例,采用大隐静脉高位结扎加剥脱术治疗,B组80例,采用高位结扎加腔内激光治疗,比较两组在手术过程、术后疼痛、术后恢复及并发症发生率等方面的差别.结果:B组患者切口个数、手术时间、术中出血量、止痛药使用百分比和平均住院时间均少于A组(P0.05).结论:大隐静脉高住结扎加腔内激光术的临床疗效优于传统的高位结扎加剥脱术,且患者损伤小、恢复快、疼痛轻,值得临床推广.%Objective: To study the clinical significance of high ligation and intracavitary laser in the treatment of varicosis of great saphenous vein.Methods: In the A group, 70 cases with varicosis of great saphenous vein were treated by high ligation and stripping procedure, and 80 cases in B group by high ligation and intracavitary laser.To compare the curative effect of A and B group, the surgical procedure, postoperative pain, postoperative recovery and complication incidence were evaluated and analyzed.Results: The operation incision, surgery duration, amount of intraoperative bleeding, percentage of patients taking painkillers, duration of hospitalisation in group B were all significantly lower than those in group A (P<0.01 or 0.05), but there was no difference in NRE scores, time for first ambulation and complication incidence between the two groups (P>0.05).Conclusion: The high ligation and intracavitary laser procedure for varicosis of great saphenous vein has proved to be more effective than traditional method for low patient injury, rapid recovery and light pain, deserving to be widely used in clinical therapy.

  6. Great Salt Lake halophilic microorganisms as models for astrobiology: evidence for desiccation tolerance and ultraviolet irradiation resistance

    Science.gov (United States)

    Baxter, Bonnie K.; Eddington, Breanne; Riddle, Misty R.; Webster, Tabitha N.; Avery, Brian J.

    2007-09-01

    Great Salt Lake (GSL) is home to halophiles, salt-tolerant Bacteria and Archaea, which live at 2-5M NaCl. In addition to salt tolerance, GSL halophiles exhibit resistance to both ultraviolet (UV) irradiation and desiccation. First, to understand desiccation resistance, we sought to determine the diversity of GSL halophiles capable of surviving desiccation in either recently formed GSL halite crystals or GSL Artemia (brine shrimp) cysts. From these desiccated environments, surviving microorganisms were cultured and isolated, and genomic DNA was extracted from the individual species for identification by 16S rRNA gene homology. From the surface-sterilized cysts we also extracted DNA of the whole microbial population for non-cultivation techniques. We amplified the archaeal or bacterial 16S rRNA gene from all genomic DNA, cloned the cyst population amplicons, and sequenced. These sequences were compared to gene databases for determination of closest matched species. Interestingly, the isolates from the crystal dissolution are distinct from those previously isolated from GSL brine. The cyst population results reveal species not found in crystals or brine, and may indicate microorganisms that live as endosymbionts of this hypersaline arthropod. Second, we explored UV resistance in a GSL haloarchaea species, "H. salsolis." This strain resists UV irradiation an order of magnitude better than control species, all of which have intact repair systems. To test the hypothesis that halophiles have a photoprotection system, which prevents DNA damage from occurring, we designed an immunoassay to detect thymine dimers following UV irradiation. "H. salsolis" showed remarkable resistance to dimer formation. Evidence for both UV and desiccation resistance in these salt-tolerant GSL halophiles makes them well-suited as models for Astrobiological studies in pursuit of questions about life beyond earth.

  7. Parameterizing atmosphere-land surface exchange for climate models with satellite data: A case study for the Southern Great Plains CART site

    Science.gov (United States)

    Gao, W.

    High-resolution satellite data provide detailed, quantitative descriptions of land surface characteristics over large areas so that objective scale linkage becomes feasible. With the aid of satellite data, researchers examined the linearity of processes scaled up from 30 m to 15 km. If the phenomenon is scale invariant, then the aggregated value of a function or flux is equivalent to the function computed from aggregated values of controlling variables. The linear relation may be realistic for limited land areas having no large surface contrasts to cause significant horizontal exchange. However, for areas with sharp surface contrasts, horizontal exchange and different dynamics in the atmospheric boundary may induce nonlinear interactions, such as at interfaces of land-water, forest-farm land, and irrigated crops-desert steppe. The linear approach, however, represents the simplest scenario and is useful for developing an effective scheme for incorporating subgrid land surface processes into large-scale models. Our studies focus on coupling satellite data and ground measurements with a satellite-data-driven land surface model to parameterize surface fluxes for large-scale climate models. In this case study, we used surface spectral reflectance data from satellite remote sensing to characterize spatial and temporal changes in vegetation and associated surface parameters in an area of about 350 x 400 km covering the southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site of the US Department of Energy's Atmospheric Radiation Measurement (ARM) Program.

  8. Linking a Large-Watershed Hydrogeochemical Model to a Wetland Community-Ecosystem Model to Estimate Plant Invasion Risk in the Coastal Great Lakes Region, USA

    Science.gov (United States)

    Currie, W. S.; Bourgeau-Chavez, L. L.; Elgersma, K. J.; French, N. H. F.; Goldberg, D. E.; Hart, S.; Hyndman, D. W.; Kendall, A. D.; Martin, S. L.; Martina, J. P.

    2014-12-01

    In the Laurentian Great Lakes region of the Upper Midwest, USA, agricultural and urban land uses together with high N deposition are contributing to elevated flows of N in rivers and groundwater to coastal wetlands. The functioning of coastal wetlands, which provide a vital link between land and water, are imperative to maintaining the health of the entire Great Lakes Basin. Elevated N inflows are believed to facilitate the spread of large-stature invasive plants (cattails and Phragmites) that reduce biodiversity and have complex effects on other ecosystem services including wetland N retention and C accretion. We enhanced the ILHM (Integrated Landscape Hydrology Model) to simulate the effects of land use on N flows in streams, rivers, and groundwater throughout the Lower Peninsula of Michigan. We used the hydroperiods and N loading rates simulated by ILHM as inputs to the Mondrian model of wetland community-ecosystem processes to estimate invasion risk and other ecosystem services in coastal wetlands around the Michigan coast. Our linked models produced threshold behavior in the success of invasive plants in response to N loading, with the threshold ranging from ca. 8 to 12 g N/m2 y, depending on hydroperiod. Plant invasions increased wetland productivity 3-fold over historically oligotrophic native communities, decreased biodiversity but slightly increased wetland N retention. Regardless of invasion, elevated N loading resulted in significantly enhanced rates of C accretion, providing an important region-wide mechanism of C storage. The linked models predicted a general pattern of greater invasion risk in the southern basins of lakes Michigan and Huron relative to northern areas. The basic mechanisms of invasion have been partially validated in our field mesocosms constructed for this project. The general regional patterns of increased invasion risk have been validated through our field campaigns and remote sensing conducted for this project.

  9. A toxin-mediated size-structured population model: Finite difference approximation and well-posedness.

    Science.gov (United States)

    Huang, Qihua; Wang, Hao

    2016-08-01

    The question of the effects of environmental toxins on ecological communities is of great interest from both environmental and conservational points of view. Mathematical models have been applied increasingly to predict the effects of toxins on a variety of ecological processes. Motivated by the fact that individuals with different sizes may have different sensitivities to toxins, we develop a toxin-mediated size-structured model which is given by a system of first order fully nonlinear partial differential equations (PDEs). It is very possible that this work represents the first derivation of a PDE model in the area of ecotoxicology. To solve the model, an explicit finite difference approximation to this PDE system is developed. Existence-uniqueness of the weak solution to the model is established and convergence of the finite difference approximation to this unique solution is proved. Numerical examples are provided by numerically solving the PDE model using the finite difference scheme.

  10. Evaluation of NASA GISS post-CMIP5 single column model simulated clouds and precipitation using ARM Southern Great Plains observations

    Science.gov (United States)

    Zhang, Lei; Dong, Xiquan; Kennedy, Aaron; Xi, Baike; Li, Zhanqing

    2017-03-01

    The planetary boundary layer turbulence and moist convection parameterizations have been modified recently in the NASA Goddard Institute for Space Studies (GISS) Model E2 atmospheric general circulation model (GCM; post-CMIP5, hereafter P5). In this study, single column model (SCM P5) simulated cloud fractions (CFs), cloud liquid water paths (LWPs) and precipitation were compared with Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) groundbased observations made during the period 2002-08. CMIP5 SCM simulations and GCM outputs over the ARM SGP region were also used in the comparison to identify whether the causes of cloud and precipitation biases resulted from either the physical parameterization or the dynamic scheme. The comparison showed that the CMIP5 SCM has difficulties in simulating the vertical structure and seasonal variation of low-level clouds. The new scheme implemented in the turbulence parameterization led to significantly improved cloud simulations in P5. It was found that the SCM is sensitive to the relaxation time scale. When the relaxation time increased from 3 to 24 h, SCM P5-simulated CFs and LWPs showed a moderate increase (10%-20%) but precipitation increased significantly (56%), which agreed better with observations despite the less accurate atmospheric state. Annual averages among the GCM and SCM simulations were almost the same, but their respective seasonal variations were out of phase. This suggests that the same physical cloud parameterization can generate similar statistical results over a long time period, but different dynamics drive the differences in seasonal variations. This study can potentially provide guidance for the further development of the GISS model.

  11. Modeling Evaporation of Drops of Different Kerosenes

    Science.gov (United States)

    Bellan, Josette; Harstad, Kenneth

    2007-01-01

    A mathematical model describes the evaporation of drops of a hydrocarbon liquid composed of as many as hundreds of chemical species. The model is intended especially for application to any of several types of kerosenes commonly used as fuels. The concept of continuous thermodynamics, according to which the chemical composition of the evaporating multicomponent liquid is described by use of a probability distribution function (PDF). However, the present model is more generally applicable than is its immediate predecessor.

  12. Advantages and Limitations of Different SDLC Models

    Directory of Open Access Journals (Sweden)

    Radhika D Amlani

    2012-11-01

    Full Text Available Software engineering is the area which is constantly growing. It is very interesting subject to learn as all the software development industry based on this specified area. Now a days, there are lots of software development life cycle models available. According to the requirements, software industry people are using it as per their requirements. As there are lots of SDLC models, they are used according to their requirements. So, it is needed to know the requirements in which the SDLC models is used. This paper is about the pros and cons of some models. So, user can take the advantage of this paper to find the model best suitable for their need.

  13. Building Water Models, A Different Approach

    CERN Document Server

    Izadi, Saeed; Onufriev, Alexey V

    2014-01-01

    Simplified, classical models of water are an integral part of atomistic molecular simulations, especially in biology and chemistry where hydration effects are critical. Yet, despite several decades of effort, these models are still far from perfect. Presented here is an alternative approach to constructing point charge water models - currently, the most commonly used type. In contrast to the conventional approach, we do not impose any geometry constraints on the model other than symmetry. Instead, we optimize the distribution of point charges to best describe the "electrostatics" of the water molecule, which is key to many unusual properties of liquid water. The search for the optimal charge distribution is performed in 2D parameter space of key lowest multipole moments of the model, to find best fit to a small set of bulk water properties at room temperature. A virtually exhaustive search is enabled via analytical equations that relate the charge distribution to the multipole moments. The resulting "optimal"...

  14. Great Expectations. [Lesson Plan].

    Science.gov (United States)

    Devine, Kelley

    Based on Charles Dickens' novel "Great Expectations," this lesson plan presents activities designed to help students understand the differences between totalitarianism and democracy; and a that a writer of a story considers theme, plot, characters, setting, and point of view. The main activity of the lesson involves students working in groups to…

  15. Deep Drawing Simulations With Different Polycrystalline Models

    Science.gov (United States)

    Duchêne, Laurent; de Montleau, Pierre; Bouvier, Salima; Habraken, Anne Marie

    2004-06-01

    The goal of this research is to study the anisotropic material behavior during forming processes, represented by both complex yield loci and kinematic-isotropic hardening models. A first part of this paper describes the main concepts of the `Stress-strain interpolation' model that has been implemented in the non-linear finite element code Lagamine. This model consists of a local description of the yield locus based on the texture of the material through the full constraints Taylor's model. The texture evolution due to plastic deformations is computed throughout the FEM simulations. This `local yield locus' approach was initially linked to the classical isotropic Swift hardening law. Recently, a more complex hardening model was implemented: the physically-based microstructural model of Teodosiu. It takes into account intergranular heterogeneity due to the evolution of dislocation structures, that affects isotropic and kinematic hardening. The influence of the hardening model is compared to the influence of the texture evolution thanks to deep drawing simulations.

  16. Experimental Diabetes Mellitus in Different Animal Models

    Directory of Open Access Journals (Sweden)

    Amin Al-awar

    2016-01-01

    Full Text Available Animal models have historically played a critical role in the exploration and characterization of disease pathophysiology and target identification and in the evaluation of novel therapeutic agents and treatments in vivo. Diabetes mellitus disease, commonly known as diabetes, is a group of metabolic disorders characterized by high blood glucose levels for a prolonged time. To avoid late complications of diabetes and related costs, primary prevention and early treatment are therefore necessary. Due to its chronic symptoms, new treatment strategies need to be developed, because of the limited effectiveness of the current therapies. We overviewed the pathophysiological features of diabetes in relation to its complications in type 1 and type 2 mice along with rat models, including Zucker Diabetic Fatty (ZDF rats, BB rats, LEW 1AR1/-iddm rats, Goto-Kakizaki rats, chemically induced diabetic models, and Nonobese Diabetic mouse, and Akita mice model. The advantages and disadvantages that these models comprise were also addressed in this review. This paper briefly reviews the wide pathophysiological and molecular mechanisms associated with type 1 and type 2 diabetes, particularly focusing on the challenges associated with the evaluation and predictive validation of these models as ideal animal models for preclinical assessments and discovering new drugs and therapeutic agents for translational application in humans.

  17. Canopy Light Absorption and Application of the Light-Use Efficiency Model of Photosynthesis in a Northern Great Plains Grassland

    Science.gov (United States)

    Flanagan, L. B.; Sharp, E. J.; Gamon, J. A.

    2014-12-01

    The fraction of absorbed photosynthetically active radiation (fAPAR) is fundamentally important for model calculations of ecosystem productivity across large areas. The main objective of this study was to better understand factors influencing fAPAR, its relationship with seasonal variation in canopy greenness (Normalized Difference Vegetation Index (NDVI)), and the consequences of potential seasonal changes in the NDVI- fAPAR relationship for light-use efficiency model calculations of ecosystem photosynthesis in a semi-arid grassland. We used two approaches to determine fAPAR, (i) incoming and outgoing radiance measurements above and below the canopy, and (ii) an inversion approach based on incident photosynthetically active radiation and the light response curve of net ecosystem productivity (NEP) measured by eddy covariance at low light levels. The two approaches resulted in fAPAR values that were very strongly correlated during the initial development of the canopy until peak leaf area index (LAI) was reached. A strong linear relationship also occurred between fAPAR and NDVI, based on reflectance measurements made along a tram system above the grassland canopy during initial LAI development. After peak LAI, there was hysteresis in the NDVI- fAPAR relationship. Light-use efficiency model calculations of ecosystem photosynthesis made using fAPAR values were strongly correlated with chamber CO2 exchange measurements during the initial development of the canopy leaf area. After peak LAI, a relative stress function, based on either soil moisture or vapour pressure deficit (VPD) measurements, was necessary to reduce quantum yield and model calculations of ecosystem photosynthesis during periods of relatively low soil moisture and higher VPD later in the growing season. Both stress functions were similarly effective in improving the correlation between modeled and measured ecosystem photosynthesis values.

  18. Do Orientation-Based Differences in Nestbox Temperature Cause Differential Ectoparasite Load and Explain Patterns of Nest-Site Selection and Offspring Condition in Great Tits?

    Directory of Open Access Journals (Sweden)

    Anne E. Goodenough

    2011-01-01

    Full Text Available Nest ectoparasites have been linked previously to patterns of nest-site choice and breeding success in birds. Recent research has shown nestboxes facing south-southwest are occupied less frequently by great tits (Parus major than identical boxes facing other directions, and are associated with reduced offspring condition. Here, we investigate the hypothesis that these findings are due to ectoparasite load being directionally nonuniform, possibly because of nonuniformity in nestbox internal temperature. Nests contained, in order of prevalence, hen fleas (Ceratophyllus gallinae, haematophagous blowflies (Protocalliphora spp., biting lice (Ischnocera, and ticks/mites (Acari. Although southwest-facing nestboxes were significantly warmer than other boxes, there was no directional difference in total ectoparasite load or abundance of particular species. Similarly, there was no relationship between abundance of any ectoparasite species (either per-nest or per-chick and avian offspring condition determined using wing length or relative mass. We discuss several possible, nonmutually exclusive, explanations for this, including compensatory responses, costs of parasitism being transferred to parents, and condition-dependent effects.

  19. A Habitat-based Wind-Wildlife Collision Model with Application to the Upper Great Plains Region

    Energy Technology Data Exchange (ETDEWEB)

    Forcey, Greg, M.

    2012-08-28

    Most previous studies on collision impacts at wind facilities have taken place at the site-specific level and have only examined small-scale influences on mortality. In this study, we examine landscape-level influences using a hierarchical spatial model combined with existing datasets and life history knowledge for: Horned Lark, Red-eyed Vireo, Mallard, American Avocet, Golden Eagle, Whooping Crane, red bat, silver-haired bat, and hoary bat. These species were modeled in the central United States within Bird Conservation Regions 11, 17, 18, and 19. For the bird species, we modeled bird abundance from existing datasets as a function of habitat variables known to be preferred by each species to develop a relative abundance prediction for each species. For bats, there are no existing abundance datasets so we identified preferred habitat in the landscape for each species and assumed that greater amounts of preferred habitat would equate to greater abundance of bats. The abundance predictions for bird and bats were modeled with additional exposure factors known to influence collisions such as visibility, wind, temperature, precipitation, topography, and behavior to form a final mapped output of predicted collision risk within the study region. We reviewed published mortality studies from wind farms in our study region and collected data on reported mortality of our focal species to compare to our modeled predictions. We performed a sensitivity analysis evaluating model performance of 6 different scenarios where habitat and exposure factors were weighted differently. We compared the model performance in each scenario by evaluating observed data vs. our model predictions using spearmans rank correlations. Horned Lark collision risk was predicted to be highest in the northwestern and west-central portions of the study region with lower risk predicted elsewhere. Red-eyed Vireo collision risk was predicted to be the highest in the eastern portions of the study region and in

  20. A Habitat-based Wind-Wildlife Collision Model with Application to the Upper Great Plains Region

    Energy Technology Data Exchange (ETDEWEB)

    Forcey, Greg, M.

    2012-08-28

    Most previous studies on collision impacts at wind facilities have taken place at the site-specific level and have only examined small-scale influences on mortality. In this study, we examine landscape-level influences using a hierarchical spatial model combined with existing datasets and life history knowledge for: Horned Lark, Red-eyed Vireo, Mallard, American Avocet, Golden Eagle, Whooping Crane, red bat, silver-haired bat, and hoary bat. These species were modeled in the central United States within Bird Conservation Regions 11, 17, 18, and 19. For the bird species, we modeled bird abundance from existing datasets as a function of habitat variables known to be preferred by each species to develop a relative abundance prediction for each species. For bats, there are no existing abundance datasets so we identified preferred habitat in the landscape for each species and assumed that greater amounts of preferred habitat would equate to greater abundance of bats. The abundance predictions for bird and bats were modeled with additional exposure factors known to influence collisions such as visibility, wind, temperature, precipitation, topography, and behavior to form a final mapped output of predicted collision risk within the study region. We reviewed published mortality studies from wind farms in our study region and collected data on reported mortality of our focal species to compare to our modeled predictions. We performed a sensitivity analysis evaluating model performance of 6 different scenarios where habitat and exposure factors were weighted differently. We compared the model performance in each scenario by evaluating observed data vs. our model predictions using spearmans rank correlations. Horned Lark collision risk was predicted to be highest in the northwestern and west-central portions of the study region with lower risk predicted elsewhere. Red-eyed Vireo collision risk was predicted to be the highest in the eastern portions of the study region and in

  1. Climate change effects on wildland fire risk in the Northeastern and Great Lakes states predicted by a downscaled multi-model ensemble

    Science.gov (United States)

    Kerr, Gaige Hunter; DeGaetano, Arthur T.; Stoof, Cathelijne R.; Ward, Daniel

    2016-11-01

    This study is among the first to investigate wildland fire risk in the Northeastern and the Great Lakes states under a changing climate. We use a multi-model ensemble (MME) of regional climate models from the Coordinated Regional Downscaling Experiment (CORDEX) together with the Canadian Forest Fire Weather Index System (CFFWIS) to understand changes in wildland fire risk through differences between historical simulations and future projections. Our results are relatively homogeneous across the focus region and indicate modest increases in the magnitude of fire weather indices (FWIs) during northern hemisphere summer. The most pronounced changes occur in the date of the initialization of CFFWIS and peak of the wildland fire season, which in the future are trending earlier in the year, and in the significant increases in the length of high-risk episodes, defined by the number of consecutive days with FWIs above the current 95th percentile. Further analyses show that these changes are most closely linked to expected changes in the focus region's temperature and precipitation. These findings relate to the current understanding of particulate matter vis-à-vis wildfires and have implications for human health and local and regional changes in radiative forcings. When considering current fire management strategies which could be challenged by increasing wildland fire risk, fire management agencies could adapt new strategies to improve awareness, prevention, and resilience to mitigate potential impacts to critical infrastructure and population.

  2. Hegemony of the "Great Equalizer" and the Fragmentation of Common Sense: A Gramscian Model of Inflated Ambitions for Schooling

    Science.gov (United States)

    Isseks, Jerald

    2017-01-01

    Increasingly over the past 50 years, the mission statement of schooling in dominant US-American discourse has coalesced around a "Great Equalizer" narrative of education; that is, it has identified schools as the primary means through which individuals can achieve social mobility. In this article, I employ a Gramscian framework to…

  3. Difference-based Model Synchronization in an Industrial MDD Process

    DEFF Research Database (Denmark)

    Könemann, Patrick; Kindler, Ekkart; Unland, Ludger

    2009-01-01

    Models play a central role in model-driven software engineering. There are different kinds of models during the development process, which are related to each other and change over time. Therefore, it is difficult to keep the different models consistent with each other. Consistency of different...... model versions, and for synchronizing other types of models. The main concern is to apply our concepts to an industrial process, in particular keeping usability and performance in mind. Keyword: Model Differencing, Model Merging, Model Synchronization...... models is maintained manually in many cases today. This paper presents an approach for automated model differencing, so that the differences between two model versions can be extracted and stored. It can then be re-used independently of the models it was created from to interactively merge different...

  4. Expanding Universe: Thermodynamical Aspects From Different Models

    CERN Document Server

    Pal, Sridip

    2012-01-01

    The pivotal point of the paper is to discuss the behavior of temperature, pressure, energy density as a function of volume along with determination of caloric EoS from following two model: $w(z)=w_{0}+w_{1}\\ln(1+z)$ & $ w(z)=-1+\\frac{(1+z)}{3}\\frac{A_{1}+2A_{2}(1+z)}{A_{0}+2A_{1}(1+z)+A_{2}(1+z)^{2}}$. The time scale of instability for this two models is discussed. In the paper we then generalize our result and arrive at general expression for energy density irrespective of the model. The thermodynamical stability for both of the model and the general case is discussed from this viewpoint. We also arrive at a condition on the limiting behavior of thermodynamic parameter to validate the third law of thermodynamics and interpret the general mathematical expression of integration constant $U_{0}$ (what we get while integrating energy conservation equation) physically relating it to number of micro states. The constraint on the allowed values of the parameters of the models is discussed which ascertains stabi...

  5. Modelling classroom conditions with different boundary conditions

    DEFF Research Database (Denmark)

    Marbjerg, Gerd Høy; Jeong, Cheol-Ho; Brunskog, Jonas

    2014-01-01

    both specular and diffuse reflections with complex-valued acoustical descriptions of the surfaces. In this paper the PARISM model is used to simulate a rectangular room with most of the absorption located in the ceiling. This room configuration is typical for classroom conditions. The simulations...... measures which are important for evaluation of the acoustics in classrooms....

  6. Modelling classroom conditions with different boundary conditions

    DEFF Research Database (Denmark)

    Marbjerg, Gerd Høy; Jeong, Cheol-Ho; Brunskog, Jonas

    2014-01-01

    both specular and diffuse reflections with complex-valued acoustical descriptions of the surfaces. In this paper the PARISM model is used to simulate a rectangular room with most of the absorption located in the ceiling. This room configuration is typical for classroom conditions. The simulations...

  7. A case study of the Great Plains low-level jet using wind profiler network data and a high resolution mesoscale model

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, S.; Fast, J.D.; Bian, X.; Stage, S. [Pacific Northwest National Lab., Richland, WA (United States)] [and others

    1996-04-01

    The Great Plains low-level jet (LLJ) has important effects on the life cycle of clouds and on radiative and surface heat and moisture fluxes at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site. This diurnal phenomenon governs the transport and convergence of low-level moisture into the region and often leads to the development of clouds and precipitation. A full understanding of the life cycle of clouds at the SGP CART site and their proper representation in single column and global climate models cannot be obtained without an improved understanding of this important phenomenon.

  8. Functional Difference Equations and an Epidemic Model.

    Science.gov (United States)

    1980-06-09

    ADDRESS 12. REPORT DATE AIR FORCE OFFICE OF SCIENTIFIC RESEARC 913 June 9, 1980 BOLLING AIR FORCE BASE , WASHINGTON, D.tI,3. NUMBEROFAGS 14. MONITORING...allowed spatial effects in an S - I model to arrive at the equation t S(t,x) = S(t,x).J B(;x, )S(t+6,0) dAdO in some region f cR. If X is the ordered

  9. Great cities look small

    CERN Document Server

    Sim, Aaron; Barahona, Mauricio; Stumpf, Michael P H

    2015-01-01

    Great cities connect people; failed cities isolate people. Despite the fundamental importance of physical, face-to-face social-ties in the functioning of cities, these connectivity networks are not explicitly observed in their entirety. Attempts at estimating them often rely on unrealistic over-simplifications such as the assumption of spatial homogeneity. Here we propose a mathematical model of human interactions in terms of a local strategy of maximising the number of beneficial connections attainable under the constraint of limited individual travelling-time budgets. By incorporating census and openly-available online multi-modal transport data, we are able to characterise the connectivity of geometrically and topologically complex cities. Beyond providing a candidate measure of greatness, this model allows one to quantify and assess the impact of transport developments, population growth, and other infrastructure and demographic changes on a city. Supported by validations of GDP and HIV infection rates ac...

  10. Finite difference computing with exponential decay models

    CERN Document Server

    Langtangen, Hans Petter

    2016-01-01

    This text provides a very simple, initial introduction to the complete scientific computing pipeline: models, discretization, algorithms, programming, verification, and visualization. The pedagogical strategy is to use one case study – an ordinary differential equation describing exponential decay processes – to illustrate fundamental concepts in mathematics and computer science. The book is easy to read and only requires a command of one-variable calculus and some very basic knowledge about computer programming. Contrary to similar texts on numerical methods and programming, this text has a much stronger focus on implementation and teaches testing and software engineering in particular. .

  11. The Great Recession was not so Great

    NARCIS (Netherlands)

    van Ours, J.C.

    2015-01-01

    The Great Recession is characterized by a GDP-decline that was unprecedented in the past decades. This paper discusses the implications of the Great Recession analyzing labor market data from 20 OECD countries. Comparing the Great Recession with the 1980s recession it is concluded that there is a hi

  12. Non-lane-based full velocity difference car following model

    Science.gov (United States)

    Jin, Sheng; Wang, Dianhai; Tao, Pengfei; Li, Pingfan

    2010-11-01

    In order to describe car following behavior in real world, this paper presents a non-lane-based car following model by incorporating the effects of the lane width in traffic. The stability condition of the model is obtained by using the linear stability theory. And numerical simulation is carried out to validate the analytic results. The property of the model is investigated, and it is found that the proposed model can describe the phase transition of traffic flow and estimate the evolution of traffic congestion. The results implied that incorporating the lane width effects in car following model not only stabilize traffic flow and suppress the traffic jam, but also lower critical headway and increase capacity. Thus, the lateral separation effects greatly enhance the realism of car following models.

  13. The Great Lakes' regional climate regimes

    Science.gov (United States)

    Sugiyama, Noriyuki

    For the last couple of decades, the Great Lakes have undergone rapid surface warming. In particular, the magnitude of the summer surface-warming trends of the Great Lakes have been much greater than those of surrounding land (Austin and Colman, 2007). Among the Great Lakes, the deepest Lake Superior exhibited the strongest warming trend in its annual, as well as summer surface water temperature. We find that many aspects of this behavior can be explained in terms of the tendency of deep lakes to exhibit multiple regimes characterized, under the same seasonally varying forcing, by the warmer and colder seasonal cycles exhibiting different amounts of wintertime lake-ice cover and corresponding changes in the summertime lake-surface temperatures. In this thesis, we address the problem of the Great Lakes' warming using one-dimensional lake modeling to interpret diverse observations of the recent lake behavior. (Abstract shortened by ProQuest.).

  14. A comparative study of aerosol deposition in different lung models.

    Science.gov (United States)

    Yu, C P; Diu, C K

    1982-01-01

    Theoretical calculations are made on total and regional deposition of inhaled particles in the human respiratory system based upon various current lung models. It is found that although total deposition does not vary appreciably from model to model, considerably large differences are present in regional deposition. Deposition profiles along the airways from different models also show very different patterns. These differences can be explained in terms of airway dimensions and the number of structures in different models. Extension to explain intersubject variability is also made.

  15. Simulation analysis of a wind farm with different aggregated models

    DEFF Research Database (Denmark)

    Li, H.; Wang, H.; Zhao, B.

    2011-01-01

    Based on a wind farm including wind turbines with squirrel cage induction generators (SCIGs), different aggregated models of a wind farm, such as a single weighted average model, a reduced-order re-scaled model, a parameter transformed model and a single weighted arithmetic model were presented......, as well as the detailed SCIG wind turbine model. Regarding for the two cases of a wind farm including SCIGs with identical parameters and different parameters, the dynamic characteristics and transient performances of the presented wind farm using different aggregated models were studied and compared...

  16. Great Zimbabwe's water

    DEFF Research Database (Denmark)

    Pikirayi, Innocent; Sulas, Federica; Musindo, Tendai Treddah;

    2016-01-01

    , including new records on environmental sequences, modern water sources, and provisioning models from in and around Great Zimbabwe. The integration of both old and new datasets allows us to follow the history of people-water interaction from early times to the present. We argue that understanding......Once a thriving center with commercial links to the Indian Ocean, what remains of Great Zimbabwe is its monumental architecture. Its rise and decline have long been linked to environmental changes in southern Zimbabwe, beginning in the second half of the 13th century with agropastoralists thriving...... of the local environment was vital in managing both water excesses and shortages in the past, and show that some of this knowledge survives among indigenous communities linked to the site and living in the surrounding landscape. While nearby Masvingo town has persistently lived under water-emergency conditions...

  17. Quantifying restoration effectiveness using multi-scale habitat models: implications for sage-grouse in the Great Basin

    Science.gov (United States)

    Arkle, Robert S.; Pilliod, David S.; Hanser, Steven E.; Brooks, Matthew L.; Chambers, Jeanne C.; Grace, James B.; Knutson, Kevin C.; Pyke, David A.; Welty, Justin L.

    2014-01-01

    A recurrent challenge in the conservation of wide-ranging, imperiled species is understanding which habitats to protect and whether we are capable of restoring degraded landscapes. For Greater Sage-grouse (Centrocercus urophasianus), a species of conservation concern in the western United States, we approached this problem by developing multi-scale empirical models of occupancy in 211 randomly located plots within a 40 million ha portion of the species' range. We then used these models to predict sage-grouse habitat quality at 826 plots associated with 101 post-wildfire seeding projects implemented from 1990 to 2003. We also compared conditions at restoration sites to published habitat guidelines. Sage-grouse occupancy was positively related to plot- and landscape-level dwarf sagebrush (Artemisia arbuscula, A. nova, A. tripartita) and big sagebrush steppe prevalence, and negatively associated with non-native plants and human development. The predicted probability of sage-grouse occupancy at treated plots was low on average (0.09) and not substantially different from burned areas that had not been treated. Restoration sites with quality habitat tended to occur at higher elevation locations with low annual temperatures, high spring precipitation, and high plant diversity. Of 313 plots seeded after fire, none met all sagebrush guidelines for breeding habitats, but approximately 50% met understory guidelines, particularly for perennial grasses. This pattern was similar for summer habitat. Less than 2% of treated plots met winter habitat guidelines. Restoration actions did not increase the probability of burned areas meeting most guideline criteria. The probability of meeting guidelines was influenced by a latitudinal gradient, climate, and topography. Our results suggest that sage-grouse are relatively unlikely to use many burned areas within 20 years of fire, regardless of treatment. Understory habitat conditions are more likely to be adequate than overstory

  18. 3D models related to the publication: Neogene sloth assemblages (Mammalia, Pilosa) of the Cocinetas Basin (La Guajira, Colombia): implications for the Great American Biotic Interchange

    OpenAIRE

    Amson, Eli; Carrillo, Juan David; Jaramillo, Carlos

    2016-01-01

    INTRODUCTION : We here present the surface models of two specimens of sloths(Mammalia, Tardigrada) coming from the Late Pliocene WareFormation (Cocinetas Basin, La Guajira, Colombia, see Table 1). Along with three additional sloth taxa found in the same Formation, these specimens document the great diversity of this Neotropical locality. Furthermore, they represent a sloth assemblage from a locality just a few hundred thousand years older than the classically recognized first main pulse of th...

  19. Cross-scale modelling of alien and native vascular plant species richness in Great Britain: where is geodiversity information most relevant?

    Science.gov (United States)

    Bailey, Joseph; Field, Richard; Boyd, Doreen

    2016-04-01

    We assess the scale-dependency of the relationship between biodiversity and novel geodiversity information by studying spatial patterns of native and alien (archaeophytes and neophytes) vascular plant species richness at varying spatial scales across Great Britain. Instead of using a compound geodiversity metric, we study individual geodiversity components (GDCs) to advance our understanding of which aspects of 'geodiversity' are most important and at what scale. Terrestrial native (n = 1,490) and alien (n = 1,331) vascular plant species richness was modelled across the island of Great Britain at two grain sizes and several extent radii. Various GDCs (landforms, hydrology, geology) were compiled from existing national datasets and automatically extracted landform coverage information (e.g. hollows, valleys, peaks), the latter using a digital elevation model (DEM) and geomorphometric techniques. More traditional predictors of species richness (climate, widely-used topography metrics, land cover diversity, and human population) were also incorporated. Boosted Regression Tree (BRT) models were produced at all grain sizes and extents for each species group and the dominant predictors were assessed. Models with and without geodiversity data were compared. Overarching patterns indicated a clear dominance of geodiversity information at the smallest study extent (12.5km radius) and finest grain size (1x1km), which substantially decreased for each increase in extent as the contribution of climatic variables increased. The contribution of GDCs to biodiversity models was chiefly driven by landform information from geomorphometry, but hydrology (rivers and lakes), and to a lesser extent materials (soil, superficial deposits, and geology), were important, also. GDCs added significantly to vascular plant biodiversity models in Great Britain, independently of widely-used topographic metrics, particularly for native species. The wider consideration of geodiversity alongside

  20. Great Lakes Science Center

    Data.gov (United States)

    Federal Laboratory Consortium — Since 1927, Great Lakes Science Center (GLSC) research has provided critical information for the sound management of Great Lakes fish populations and other important...

  1. Estimating the economic value of national parks with count data models using on-site, secondary data: the case of the great sand dunes national park and preserve.

    Science.gov (United States)

    Heberling, Matthew T; Templeton, Joshua J

    2009-04-01

    We estimate an individual travel cost model for Great Sand Dunes National Park and Preserve (GSD) in Colorado using on-site, secondary data. The purpose of the on-site survey was to help the National Park Service better understand the visitors of GSD; it was not intended for a travel cost model. Variables such as travel cost and income were estimated based on respondents' Zip Codes. Following approaches found in the literature, a negative binomial model corrected for truncation and endogenous stratification fit the data the best. We estimate a recreational benefit of U.S. $89/visitor/year or U.S. $54/visitor/24-h recreational day (in 2002 U.S. $). Based on the approach presented here, there are other data sets for national parks, preserves, and battlefields where travel cost models could be estimated and used to support National Park Service management decisions.

  2. Europa's Great Lakes

    Science.gov (United States)

    Schmidt, B. E.; Blankenship, D. D.; Patterson, G. W.; Schenk, P. M.

    2012-04-01

    Unique to the surface of Europa, chaos terrain is diagnostic of the properties and dynamics of its icy shell. While models have suggested that partial melt within a thick shell or melt-through of a thin shell may form chaos, neither model has been able to definitively explain all observations of chaos terrain. However, we present a new model that suggests large melt lenses form within the shell and that water-ice interactions above and within these lenses drive the production of chaos. Our analysis of the geomorphology of Conamara Chaos and Thera Macula, was used to infer and test a four-stage lens-collapse chaos formation model: 1) Thermal plumes of warm, pure ice ascend through the shell melting the impure brittle ice above, producing a lake of briny water and surface down draw due to volume reduction. 2) Surface deflection and driving force from the plume below hydraulically seals the water in place. 3) Extension of the brittle ice lid generates fractures from below, allowing brines to enter and fluidize the ice matrix. 4) As the lens and now brash matrix refreeze, thermal expansion creates domes and raises the chaos feature above the background terrain. This new "lense-collapse" model indicates that chaos features form in the presence of a great deal of liquid water, and that large liquid water bodies exist within 3km of Europa's surface comparable in volume to the North American Great Lakes. The detection of shallow subsurface "lakes" implies that the ice shell is recycling rapidly and that Europa may be currently active. In this presentation, we will explore environments on Europa and their analogs on Earth, from collapsing Antarctic ice shelves to to subglacial volcanos in Iceland. I will present these new analyses, and describe how this new perspective informs the debate about Europa's habitability and future exploration.

  3. Did the Great Recession Downsize Immigrants and Native-Born Americans Differently? Unemployment Differentials by Nativity, Race and Gender from 2007 to 2013 in the U.S.

    Directory of Open Access Journals (Sweden)

    Sharron Xuanren Wang

    2016-09-01

    Full Text Available We use data from the Current Population Survey from 2007 and 2013 to investigate demographic differentials in unemployment during the Great Recession in the U.S. Although our analysis is primarily exploratory and descriptive, our major research objective is to illuminate the unemployment differential between the foreign born and the native born. The findings indicate that during the height of the Great Recession, the foreign born had higher unemployment rates than the native born. However, this differential is statistically explained by their observed characteristics, such as race/ethnicity, gender, age and education. With the net of those variables and a few other demographic covariates, foreign born workers as an overall group actually had somewhat lower chances of being unemployed than native born workers. This finding is discussed in terms of the selectivity of immigrant workers and the possibility that they are somewhat more immediately dependent on having a job. After breaking down the foreign born into major racial/ethnic groups, the results suggest that foreign-born blacks and foreign-born Hispanics are particularly selective with the net of their observed characteristics. The possible sources of such differentials by race/ethnicity and by gender are discussed.

  4. OSGM02: A new model for converting GPS-derived heights to local height datums in Great Britain and Ireland

    DEFF Research Database (Denmark)

    Iliffe, J.C.; Ziebart, M.; Cross, P.A.

    2003-01-01

    The background to the recent computation of a new vertical datum model for the British Isles (OSGM02) is described After giving a brief description of the computational techniques and the data sets used for the derivation of the gravimetric geoid, the paper focuses on the fitting of this surface...

  5. Cross-shelf exchanges between the Coral Sea and the Great Barrier Reef lagoon determined from a regional-scale numerical model

    Science.gov (United States)

    Schiller, Andreas; Herzfeld, Mike; Brinkman, Richard; Rizwi, Farhan; Andrewartha, John

    2015-10-01

    Analyses of the variability in a 3.5-year run of a hydrodynamic model developed for simulating the circulation of the Great Barrier Reef (GBR) are presented. Sea-surface temperature, salinity, currents and cross-shelf transports between the GBR lagoon and the deep ocean offshore are investigated and compare well to available observations. Water mass intrusions and flushing events are critical factors in determining the health of coral reef and continental shelf ecosystems. Results from tracer release experiments provide a synoptic view of the variability of residence times within the GBR and identify critical regions of shelf-ocean exchange. One such region of significant tracer contribution to the shelf is identified in the vicinity of the Pompey Reefs in an area characterised by increased frequency of upslope transported water. Another location of enhanced flux on to the shelf exists in the region bracketing Palm Passage, where the reef matrix is very open, and provides little obstacle to cross-shelf exchange. The Palm Passage location is the origin of a northwards plume of elevated concentration. The model circulation provides a robust and useful picture of the Great Barrier Reef, rendering the model suitable for providing input to biogeochemical and sediment models to simulate, at a broad scale, the ecosystem health, water quality, transport and fate of water and waterborne material, moving through catchments and into the GBR lagoon.

  6. Simulation analysis of a wind farm with different aggregated models

    DEFF Research Database (Denmark)

    Li, H.; Wang, H.; Zhao, B.

    2011-01-01

    , as well as the detailed SCIG wind turbine model. Regarding for the two cases of a wind farm including SCIGs with identical parameters and different parameters, the dynamic characteristics and transient performances of the presented wind farm using different aggregated models were studied and compared...

  7. Structural Equation Modeling of Multitrait-Multimethod Data: Different Models for Different Types of Methods

    Science.gov (United States)

    Eid, Michael; Nussbeck, Fridtjof W.; Geiser, Christian; Cole, David A.; Gollwitzer, Mario; Lischetzke, Tanja

    2008-01-01

    The question as to which structural equation model should be selected when multitrait-multimethod (MTMM) data are analyzed is of interest to many researchers. In the past, attempts to find a well-fitting model have often been data-driven and highly arbitrary. In the present article, the authors argue that the measurement design (type of methods…

  8. Reparameterization of Single Difference and Undifferenced Kinematic GPS Positioning Models

    Institute of Scientific and Technical Information of China (English)

    LIU Xianglin; C D Jong; C C J M Tiberius

    2003-01-01

    A series of advantages of single difference (SD)and undifferenced (ZD) models are given as compared wity the double difference ezist in SD and ZD models.The reparameterization method is provided to resolve this rank defect problem by estimating some combinations of the unknowns rather than the unknowns themselves. The repatameterization of SD and ZD functional models is discussed in detail with their stochastic models. The theoretical comformation of the equivalence of undifferenced and differenced models is described in a straightforward way .The relationship between SD and ZD residuals is given and verified for some special purposes,e.g.research on the stochastical properties of GPS observations.

  9. Moving from pixels to parcels: Modeling agricultural scenarios in the northern Great Plains using a hybrid raster- and vector-based approach

    Science.gov (United States)

    Sohl, T.; Wika, S.; Dornbierer, J.; Sayler, K. L.; Quenzer, R.

    2015-12-01

    Policy and economic driving forces have resulted in a higher demand for biofuel feedstocks in recent years, resulting in substantial increases in cultivated cropland in the northern Great Plains. A cellulosic-based biofuel industry could potentially further impact the region, with grassland and marginal agricultural land converted to perennial grasses or other feedstocks. Scenarios of projected land-use change are needed to enable regional stakeholders to plan for the potential consequences of expanded agricultural activity. Land-use models used to produce spatially explicit scenarios are typically raster-based and are poor at representing ownership units on which land-use change is based. This work describes a hybrid raster/vector-based modeling approach for modeling scenarios of agricultural change in the northern Great Plains. Regional scenarios of agricultural change from 2012 to 2050 were constructed, based partly on the U.S. Department of Energy's Billion Ton Update. Land-use data built from the 2012 Cropland Data Layer and the 2011 National Land Cover Database was used to establish initial conditions. Field boundaries from the U.S. Department of Agriculture's Common Land Unit dataset were used to establish ownership units. A modified version of the U.S. Geological Survey's Forecasting Scenarios of land-use (FORE-SCE) model was used to ingest vector-based field boundaries to facilitate the modeling of a farmer's choice of land use for a given year, while patch-based raster methodologies were used to represent expansion of urban/developed lands and other land use conversions. All modeled data were merged to a common raster dataset representing annual land use from 2012 to 2050. The hybrid modeling approach enabled the use of traditional, raster-based methods while integrating vector-based data to represent agricultural fields and other ownership-based units upon which land-use decisions are typically made.

  10. Individual variation in biomarkers of health: influence of persistent organic pollutants in Great skuas (Stercorarius skua) breeding at different geographical locations.

    Science.gov (United States)

    Bourgeon, Sophie; Leat, Eliza H K; Magnusdóttir, Ellen; Fisk, Aaron T; Furness, Robert W; Strøm, Hallvard; Hanssen, Sveinn Are; Petersen, Aevar; Olafsdóttir, Kristin; Borgå, Katrine; Gabrielsen, Geir W; Bustnes, Jan Ove

    2012-10-01

    Persistent organic pollutants (POPs) have been shown to cause adverse effects on a number of biomarkers of health in birds. POPs may impair immune function and alter the stress response, defined as a suite of behavioral and physiological responses to environmental perturbations. Recent studies have also proposed that POPs can induce oxidative stress. Nevertheless, there is a lack of studies simultaneously assessing the potential damaging effects of POPs on the latter biomarkers. In this study, we examined the contribution of legacy (organochlorines; (OCs)) and emerging (flame retardants; PBDEs) POPs to individual variations in stress levels (feather corticosterone), humoral immunity (plasma immunoglobulin Y levels) and oxidative stress occurring in three breeding colonies of a top predator seabird, the Great skua (Stercorarius skua), distributed from temperate regions to the high Arctic: Shetland (60°N), Iceland (63°N) and Bjørnøya (74°N). Our results demonstrated that plasma concentrations of OCs in Great skuas from Bjørnøya are among the highest in North Atlantic seabirds, with up to 7900 μg/kg (ww) ∑OCs. Yet, a latitudinal gradient in POP levels was observed with all compounds being significantly higher in Bjørnøya than in Iceland and Shetland (on average 4-7 fold higher for OCs and 2.5-4.5 for PBDEs, respectively). Contrary to our predictions, skuas breeding at the least contaminated site (i.e., Shetland) experienced the poorest physiological condition; i.e., the highest levels of stress hormones (25% higher) and oxidative stress (50% higher) and the lowest immunoglobulin levels (15% lower) compared to the two other colonies. Finally, our results failed to point out consistent within-colony relationships between biomarkers of health and POPs. Overall, it is suggested that other ecological factors such as food availability could constrain physiological indicators more than anthropogenic contaminants.

  11. ECONOMETRIC APPROACH TO DIFFERENCE EQUATIONS MODELING OF EXCHANGE RATES CHANGES

    Directory of Open Access Journals (Sweden)

    Josip Arnerić

    2010-12-01

    Full Text Available Time series models that are commonly used in econometric modeling are autoregressive stochastic linear models (AR and models of moving averages (MA. Mentioned models by their structure are actually stochastic difference equations. Therefore, the objective of this paper is to estimate difference equations containing stochastic (random component. Estimated models of time series will be used to forecast observed data in the future. Namely, solutions of difference equations are closely related to conditions of stationary time series models. Based on the fact that volatility is time varying in high frequency data and that periods of high volatility tend to cluster, the most successful and popular models in modeling time varying volatility are GARCH type models and their variants. However, GARCH models will not be analyzed because the purpose of this research is to predict the value of the exchange rate in the levels within conditional mean equation and to determine whether the observed variable has a stable or explosive time path. Based on the estimated difference equation it will be examined whether Croatia is implementing a stable policy of exchange rates.

  12. A source model for the great 2011 Tohoku earthquake (Mw=9.1) from inversion of GRACE gravity data

    Science.gov (United States)

    Cambiotti, G.; Sabadini, R.

    2012-06-01

    The co-seismic slip distribution of the 2011 Tohoku megathrust earthquake is constrained from GeoForschungsZentrum (GFZ) Gravity Recovery and Climate Experiment (GRACE) Level 2 data time series and our self-gravitating, compressible 1-D Earth model. After spatial localization of space gravity data in the surrounding of the U.S. Geological Survey (USGS) epicenter by means of orthogonal Slepian functions, we estimate the long-wavelength co-seismic gravity signature. The pattern is bipolar: the positive pole off-shore in the Pacific ocean (+3.6μGal) and the negative pole in the northern Japan and Japan sea (-8.6μGal). Inversion of the GRACE data resolves average features of finite fault models: the total seismic moment (5.3±1×1022Nm, corresponding to MW=9.1 in agreement with the centroid-moment-tensor solution), the rake angle (87°±9°), and the mean position of the slip distribution on the fault plane. We obtain that the mean depth of the rupture is 17.1±5km, just below the Moho discontinuity, although we cannot exclude that the rupture also extended to shallower crustal layers and deeper within the lithospheric mantle due to the poor resolution of the along-dip dimension of the fault.

  13. Modelling of Coulomb stress changes during the great (Mw = 8.8) 1906 Colombia-Ecuador earthquake

    Science.gov (United States)

    Mayorga, Edwin F.; Sánchez, John J.

    2016-10-01

    Six alternative models of slip distribution during the 1906 Esmeraldas (Mw = 8.8) megathrust earthquake are used to compute Coulomb stress changes on two types of specific faults and onto optimal strike-slipe faults along the Colombia-Ecuador Pacific region. Coulomb stress changes are in the range -0.5-0.5 MPa projected on specific faults varies spatially depending on target fault configuration (dip and sense of motion): Slip along low-angle reverse faults would be inhibited whereas slip along near-vertical strike-slip faults would be facilitated in the southern rupture region and inhibited in the northern rupture region. The patterns of Coulomb stress changes on optimal strike-slip faults located on the landward side of the 1906 rupture is not strongly dependent on the regional stress tensor, suggests that motion along many faults and fault segments might be facilitated, and exhibits good spatial correlation with shallow seismicity. The modelled 1906 Esmeraldas rupture is compared to the recent 2010 Mw = 8.8 Maule, Chile earthquake and the results may aid in improving current hazard estimates and degree of preparedness in the Colombia-Ecuador Pacific region.

  14. Differences in spatial understanding between physical and virtual models

    Directory of Open Access Journals (Sweden)

    Lei Sun

    2014-03-01

    Full Text Available In the digital age, physical models are still used as major tools in architectural and urban design processes. The reason why designers still use physical models remains unclear. In addition, physical and 3D virtual models have yet to be differentiated. The answers to these questions are too complex to account for in all aspects. Thus, this study only focuses on the differences in spatial understanding between physical and virtual models. In particular, it emphasizes on the perception of scale. For our experiment, respondents were shown a physical model and a virtual model consecutively. A questionnaire was then used to ask the respondents to evaluate these models objectively and to establish which model was more accurate in conveying object size. Compared with the virtual model, the physical model tended to enable quicker and more accurate comparisons of building heights.

  15. Adaptive finite difference for seismic wavefield modelling in acoustic media.

    Science.gov (United States)

    Yao, Gang; Wu, Di; Debens, Henry Alexander

    2016-08-05

    Efficient numerical seismic wavefield modelling is a key component of modern seismic imaging techniques, such as reverse-time migration and full-waveform inversion. Finite difference methods are perhaps the most widely used numerical approach for forward modelling, and here we introduce a novel scheme for implementing finite difference by introducing a time-to-space wavelet mapping. Finite difference coefficients are then computed by minimising the difference between the spatial derivatives of the mapped wavelet and the finite difference operator over all propagation angles. Since the coefficients vary adaptively with different velocities and source wavelet bandwidths, the method is capable to maximise the accuracy of the finite difference operator. Numerical examples demonstrate that this method is superior to standard finite difference methods, while comparable to Zhang's optimised finite difference scheme.

  16. Influence of different kind of peats on some physic-chemical properties, biochemical activity, the content of different forms of nitrogen and fractions of humic substances of The Great Vasyugan Mire

    Science.gov (United States)

    Inisheva, L. I.; Szajdak, L.

    2009-04-01

    Mires, or peatlands belong to the wetlands ecosystems where carbon is bounded in primary production and deposited as peat in water saturated, anoxic conditions. In those conditions, the rate of the supply of new organic matter has exceeded that the decomposition, resulting in carbon accumulation. Place of sampling belongs to an oligotrophic landscapes of the river Klyuch basin in spurs of Vasyugan mire. The catchment represents reference system for Bokchar swampy area (political district of Tomsk region). Landscape profile crosses main kinds of swampy biogeocoenosis (BGC) toward the mire center: paludal tall mixed forest, pine undershrub Sphagnum (high riam, trans-accumulative part of a profile, P2), pine-undershrub Sphagnum (low riam, transit part, P3), sedge-moss swamp (eluvial part, P5). The latter represents an eluvial part of a slope of watershed massif where it is accomplished discharge of excess, surface, soil-mire waters. The depth of peat deposit of sedge-moss swamp reaches 2,5m. To the depth of 0,6m there is a layer of Sphagnum raised bog peat, then it is a mesotrophic Scheuchzeria Sphagnum layer and at the bottom there is a thick layer of low-mire horsetail peat. The samples of peats were taken from two places (P2 and P3), both from the depth 0-75 cm of the great Vasyugan Mire. These materials represent (P2) Sphagnum fuscum peat (ash content ranged from 10.8 to 15.1%), but samples P3 belong to low-moor sedge peat (ash content ranged from 4.5-4.8%). The differences in water level, redox potential, pH, degree of degradation, bulk density, number of microorganisms, activity of enzymes, different kinds of nitrogen and humic substances were studied in two different peat soils characterized by different type of peat. In general in P2 the redox potential changed from 858 to /-140/ mV, higher activity of xanthine oxidase and peroxidase, different kinds of microorganisms (ammonifing bacteria and cellulose decomposing microorganisms) and different kinds of

  17. Quantum correlations dynamics under different non-markovian environmental models

    CERN Document Server

    Zhang, Ying-Jie; Shan, Chuan-Jia; Xia, Yun-Jie

    2011-01-01

    We investigate the roles of different environmental models on quantum correlation dynamics of two-qubit composite system interacting with two independent environments. The most common environmental models (the single-Lorentzian model, the squared-Lorentzian model, the two-Lorentzian model and band-gap model) are analyzed. First, we note that for the weak coupling regime, the monotonous decay speed of the quantum correlation is mainly determined by the spectral density functions of these different environments. Then, by considering the strong coupling regime we find that, contrary to what is stated in the weak coupling regime, the dynamics of quantum correlation depends on the non-Markovianity of the environmental models, and is independent of the environmental spectrum density functions.

  18. Comparison of four different models of vortex generators

    DEFF Research Database (Denmark)

    Fernandez, U.; Réthoré, Pierre-Elouan; Sørensen, Niels N.

    2012-01-01

    A detailed comparison between four different models of vortex generators is presented in this paper. To that end, a single Vortex Generator on a flat plate test case has been designed and solved by the following models. The first one is the traditional mesh-resolved VG and the second one, called...... Actuator Vortex Generator Model (AcVG), is based on the lifting force theory of Bender, Anderson and Yagle, the BAY Model, which provides an efficient method for computational fluid dynamic (CFD) simulations of flow with VGs, and the forces are applied into the computational domain using the actuator shape...... model. This AcVG Model enables to simulate the effects of the Vortex Generators without defining the geometry of the vortex generator in the mesh and makes it easier for researchers the investigations of different vortex generator lay outs. Both models have been archived by the in house EllipSys CFD...

  19. A model approach to project the start of egg laying of Great Tit ( Parus major L.) in response to climate change

    Science.gov (United States)

    Chmielewski, Frank-M.; Blümel, Klaus; Scherbaum-Heberer, Carina; Koppmann-Rumpf, Bettina; Schmidt, Karl-Heinz

    2013-03-01

    The aim of this study was to select a phenological model that is able to calculate the beginning of egg laying of Great Tit ( Parus major) for both current and future climate conditions. Four models (M1-M4) were optimised on long-term phenological observations from the Ecological Research Centre Schlüchtern (Hessen/Germany). Model M1 was a common thermal time model that accumulates growing degree days (GDD) on an optimised starting date t 1. Since egg laying of Great Tit is influenced not only by air temperature but also by photoperiod, model M1 was extended by a daylength term to give M2. The other two models, M3 and M4, correspond to M1 and M2, but t 1 was intentionally set to 1 January, in order to consider already rising temperatures at the beginning of the year. A comparison of the four models led to following results: model M1 had a relatively high root mean square error at verification (RMSEver) of more than 4 days and can be used only to calculate the start of egg laying for current climate conditions because of the relatively late starting date for GDD calculation. The model failed completely if the starting date was set to 1 January (M3). Consideration of a daylength term in models M2 and M4 improved the performance of both models strongly (RMSEver of only 3 days or less), increased the credibility of parameter estimation, and was a precondition to calculate reliable projections in the timing of egg laying in birds for the future. These results confirm that the start of egg laying of Great Tit is influenced not only by air temperature, but also by photoperiod. Although models M2 and M4 both provide comparably good results for current climate conditions, we recommend model M4-with a starting date of temperature accumulation on 1 January-for calculating possible future shifts in the commencement of egg laying. Our regional projections in the start of egg laying, based on five regional climate models (RCMs: REMO-UBA, ECHAM5-CLM, HadCM3-CLM, WETTREG-0

  20. Microstructure and cross-sectional shape of limb bones in Great Horned Owls and Red-tailed Hawks: how do these features relate to differences in flight and hunting behavior?

    Science.gov (United States)

    Marelli, Crystal A; Simons, Erin L R

    2014-01-01

    The Red-tailed Hawk and Great Horned Owl are two species of raptor that are similar in body size, diet, and habitat. Both species use their hindlimbs during hunting, but differ in foot morphology, how they approach and immobilize prey, and the average size of prey captured. They also differ in primary flight style: the Red-tailed Hawk uses static soaring and the Great Horned Owl uses flap-gliding. The objectives of this study were to characterize the microstructure and cross-sectional shape of limb bones of these species and examine the relationship with flight and hunting behaviors. The mid-shaft of six limb bones from six individuals of each species was sampled. The degree of bone laminarity (proportion of circular primary vascular canals) and cross-sectional geometric parameters were calculated. In both species, the humerus and femur exhibited features that suggest high resistance to torsional loading, whereas the tibiotarsus and phalanges had a shape more likely to resist compression and bending in a specific plane. The femur of the Red-tailed Hawk exhibited higher laminarity and larger polar moment of area than that of the Great Horned Owl. The tibiotarsus was more elliptical than that of the Great Horned Owl. The hawk approaches prey from a more horizontal axis, takes prey of greater mass, and is more likely to pursue prey on the ground, which could potentially be causing more torsional loads on the femur and bending loads on the tibiotarsus. In addition, differences in polar moment of area of the phalanges between the species could relate to differences in foot morphology or digit length. The humerus and ulna of the flap-gliding Great Horned Owl are more elliptical than the static soaring Red-tailed Hawk, a shape that may better resist the bending loads associated with a larger amount of flapping.

  1. Microstructure and cross-sectional shape of limb bones in Great Horned Owls and Red-tailed Hawks: how do these features relate to differences in flight and hunting behavior?

    Directory of Open Access Journals (Sweden)

    Crystal A Marelli

    Full Text Available The Red-tailed Hawk and Great Horned Owl are two species of raptor that are similar in body size, diet, and habitat. Both species use their hindlimbs during hunting, but differ in foot morphology, how they approach and immobilize prey, and the average size of prey captured. They also differ in primary flight style: the Red-tailed Hawk uses static soaring and the Great Horned Owl uses flap-gliding. The objectives of this study were to characterize the microstructure and cross-sectional shape of limb bones of these species and examine the relationship with flight and hunting behaviors. The mid-shaft of six limb bones from six individuals of each species was sampled. The degree of bone laminarity (proportion of circular primary vascular canals and cross-sectional geometric parameters were calculated. In both species, the humerus and femur exhibited features that suggest high resistance to torsional loading, whereas the tibiotarsus and phalanges had a shape more likely to resist compression and bending in a specific plane. The femur of the Red-tailed Hawk exhibited higher laminarity and larger polar moment of area than that of the Great Horned Owl. The tibiotarsus was more elliptical than that of the Great Horned Owl. The hawk approaches prey from a more horizontal axis, takes prey of greater mass, and is more likely to pursue prey on the ground, which could potentially be causing more torsional loads on the femur and bending loads on the tibiotarsus. In addition, differences in polar moment of area of the phalanges between the species could relate to differences in foot morphology or digit length. The humerus and ulna of the flap-gliding Great Horned Owl are more elliptical than the static soaring Red-tailed Hawk, a shape that may better resist the bending loads associated with a larger amount of flapping.

  2. Formation of Mobilization Model and Macroeconomic Dynamics of the USSR During the First Five-Year Period and the Great Patriotic War

    Directory of Open Access Journals (Sweden)

    Cheremisinov Georgiy Aleksandrovich

    2015-11-01

    Full Text Available The research of origin and functioning of mobilization model of economy is possible on the basis of the hypothesis about the government entrepreneurship as a typological sign of Russian economy development, the concept of threshold changes of macroeconomic dynamics, methodology of a chronotope and the theory of interrelation of the government organization of accumulation of the capital, industrialization, militarization, economic and territorial expansion of state power. Socio-economic reforming in our country was connected with threshold levels of impact of the government on economy that is confirmed by the analysis of macroeconomic conditions of emergence of the centralized planned management of a national economy. System transformations of the Russian economy to the revolutionary-military period (1914-1920 in the second half of the 1920s – early 1930s, in the period of the Great Patriotic War were carried out by the ruling power for the purpose of increase in quantity of the benefits, services, factors of production appropriated, distributed or used in its interests. The level of the centralized withdrawal of resources on irretrievable military expenses and on investments into industrialization of the power defined macroeconomic dynamics and extent of reorganization of a market mechanism of regulation of a domestic national economy. The mobilization model of directive planned management of a national economy created as a result of reforms of the beginning of the 1930s provided an economic basis of the USSR victory in the Great Patriotic War.

  3. A model of the effects of land-based, human activities on the health of coral reefs in the Great Barrier Reef and in Fouha Bay, Guam, Micronesia

    Science.gov (United States)

    Wolanski, Eric; Richmond, Robert H.; McCook, Laurence

    2004-05-01

    A model is proposed to explain coral and algal abundance on coastal coral reefs as a function of spike-like natural disturbances from tropical cyclones and turbid river floods, followed by long recovery periods where the rate of reef recovery depends on ambient water and substratum quality. The model includes competition for space between corals and algae, coral recruitment and reef connectivity. The model is applied to a 400-km stretch of Australia's Great Barrier Reef and to the 200-m-long reef tract at Fouha Bay, in Guam, Micronesia. For these two sites and at these two scales, the model appears successful at reproducing the observed distribution of algae and coral. For both sites, it is suggested that the reefs have been degraded by human activities on land and that they will recover provided remedial measures are implemented on land to restore the water and substrate conditions. We suggest ways to improve the model and to use the model to guide future ecological research and management efforts on coastal coral reefs.

  4. The Role of Surface Energy Exchange for Simulating Wind Inflow: An Evaluation of Multiple Land Surface Models in WRF for the Southern Great Plains Site Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Wharton, Sonia [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simpson, Matthew [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Osuna, Jessica [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Newman, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Biraud, Sebastien [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-05-01

    The Weather Research and Forecasting (WRF) model is used to investigate choice of land surface model (LSM) on the near-surface wind profile, including heights reached by multi-megawatt wind turbines. Simulations of wind profiles and surface energy fluxes were made using five LSMs of varying degrees of sophistication in dealing with soil-plant-atmosphere feedbacks for the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) Central Facility in Oklahoma. Surface-flux and wind-profile measurements were available for validation. The WRF model was run for three two-week periods during which varying canopy and meteorological conditions existed. The LSMs predicted a wide range of energy-flux and wind-shear magnitudes even during the cool autumn period when we expected less variability. Simulations of energy fluxes varied in accuracy by model sophistication, whereby LSMs with very simple or no soil-plant-atmosphere feedbacks were the least accurate; however, the most complex models did not consistently produce more accurate results. Errors in wind shear also were sensitive to LSM choice and were partially related to the accuracy of energy flux data. The variability of LSM performance was relatively high, suggesting that LSM representation of energy fluxes in the WRF model remains a significant source of uncertainty for simulating wind turbine inflow conditions.

  5. Nonstandard Finite Difference Method Applied to a Linear Pharmacokinetics Model

    Directory of Open Access Journals (Sweden)

    Oluwaseun Egbelowo

    2017-05-01

    Full Text Available We extend the nonstandard finite difference method of solution to the study of pharmacokinetic–pharmacodynamic models. Pharmacokinetic (PK models are commonly used to predict drug concentrations that drive controlled intravenous (I.V. transfers (or infusion and oral transfers while pharmacokinetic and pharmacodynamic (PD interaction models are used to provide predictions of drug concentrations affecting the response of these clinical drugs. We structure a nonstandard finite difference (NSFD scheme for the relevant system of equations which models this pharamcokinetic process. We compare the results obtained to standard methods. The scheme is dynamically consistent and reliable in replicating complex dynamic properties of the relevant continuous models for varying step sizes. This study provides assistance in understanding the long-term behavior of the drug in the system, and validation of the efficiency of the nonstandard finite difference scheme as the method of choice.

  6. The GREAT-ER model in China: Evaluating the risk of both treated and untreated wastewater discharges and a consideration to the future.

    Science.gov (United States)

    Jackson, Benjamin; Jones, Kevin; Sweetman, Andrew

    2016-04-01

    As a result of rapid economic development, the production and usage of chemicals in China has risen significantly. This has resulted in China's environment becoming degraded. The Chinese government has attempted to ease these problems with significant investment towards upgrading the wastewater network. These efforts have initially focused upon large cities; progressing towards smaller populations within the most recent 5 year plan. However rural populations were largely overlooked, ~90% of rural settlements do not have treatment facilities for their wastewater. The next (13th) five year plan is a great opportunity to improve upon wastewater infrastructure. This transition is particularly important and it is essential for the government to prioritise settlements to provide treatment facilities and to improve water quality in receiving waters. This study focuses upon the use of a catchment model in order make progress towards this goal. A reliable model which can capture the complexity of the catchment is needed, but one without complexity in itself, in order for it to be developed and validated without an excessive requirement for data. The Geo-referenced Regional Exposure Assessment Tool for European Rivers (GREAT-ER) model is a catchment-scale stochastic-deterministic GIS model. It is primarily used for higher-tier chemical risk assessment. Emissions are from point source only and are calculated based upon population and calculated emission rates per capita. Dilution and transportation are determined using low-flow statistics within each stretch; calculated based upon catchment soil and topographic properties. Removal of the contaminant can occur prior to emission and in-stream. The lowest tier methodology applies a simple 1st-order removal rate and a flat percentage removal for in-stream and sewage treatment work removal respectively. The data requirements are relatively low, although still challenging for many situations. Many authors have reported reasonable

  7. Differences in Family Planning Services by Rural-urban Geography: Survey of Title X-Supported Clinics In Great Plains and Midwestern States.

    Science.gov (United States)

    Martins, Summer L; Starr, Katherine A; Hellerstedt, Wendy L; Gilliam, Melissa L

    2016-03-01

    Understanding the nature of rural-urban variation in U.S. family planning services would help address disparities in unmet contraceptive need. In 2012, some 558 Title X-supported clinics in 16 Great Plains and Midwestern states were surveyed. Rural-urban commuting area (RUCA) codes were used to categorize clinic locations as urban, large rural city, small rural town or isolated small rural town. Bivariate analyses examined key domains of service provision by RUCA category and clinic type. The proportion of clinics offering walk-in appointments was lower in isolated small rural towns (47%) than in the other RUCA categories (67-73%). Results were similar for sites that do not specialize in family planning or reproductive health, but no variation was seen among specialty clinics. Overall, availability of evening or weekend appointments varied in a linear fashion, falling from 73% in urban areas to 29% in isolated small rural towns. On-site provision of most hormonal methods was most common in urban areas and least common in isolated small rural towns, while provision of nonhormonal methods was similar across RUCA categories. Sixty percent of clinics provided IUDs or implants. For clinics that did not, the only barriers that varied geographically were low IUD demand and lack of trained IUD providers; these barriers were most common in isolated rural towns (42% and 70%, respectively). While important characteristics, such as clinics' specialization (or lack thereof), are linked to the provision of family planning services, geographic disparities exist. Copyright © 2016 by the Guttmacher Institute.

  8. Discrimination and Skill Differences in an Equilibrium Search Model

    NARCIS (Netherlands)

    Bowlus, Audra J.; Eckstein, Zvi

    1998-01-01

    In this paper we analyze an equilibrium search model with threesources for wage andunemployment differentials among workers with the same (observed) human capital but different appearance (race): unobserved productivity (skill), search intensities and discrimination (Becker 1957)due to an

  9. Discrimination and Skill Differences in an Equilibrium Search Model

    NARCIS (Netherlands)

    Bowlus, Audra J.; Eckstein, Zvi

    1998-01-01

    In this paper we analyze an equilibrium search model with threesources for wage andunemployment differentials among workers with the same (observed) human capital but different appearance (race): unobserved productivity (skill), search intensities and discrimination (Becker 1957)due to an appearanc

  10. 3D City Models with Different Temporal Characteristica

    DEFF Research Database (Denmark)

    Bodum, Lars

    2005-01-01

    traditional static city models and those models that are built for realtime applications. The difference between the city models applies both to the spatial modelling and also when using the phenomenon time in the models. If the city models are used in visualizations without any variation in time or when......-built dynamic or a model suitable for visualization in realtime, it is required that modelling is done with level-of-detail and simplification of both the aesthetics and the geometry. If a temporal characteristic is combined with a visual characteristic, the situation can easily be seen as a t/v matrix where t...... is the temporal characteristic or representation and v is the visual characteristic or representation....

  11. 3D City Models with Different Temporal Characteristica

    DEFF Research Database (Denmark)

    Bodum, Lars

    2005-01-01

    the variation in time is non-synchronous with real-time, usually more effort can be put on the fi delity in relation to the aesthetic and geometric representation. This means that the models are more realistic or contain another level of detail. However, if one looks at virtual environments with an in......3D city models are mostly seen as static or at least as background for various animations types. In the last couple of years, experts have realized that 3D city models (technical maps of the future) should be maintained in order to be used in a continuous and dynamical planning and administration....... Therefore it is important that temporal information is attached to the different parts of a city model so that it can be used as part of metadata for city models. Another and just as important use of time is related to the temporal characteristics of the 3D city models. There is a huge difference between...

  12. Evaluating sand and clay models: do rheological differences matter?

    Science.gov (United States)

    Eisenstadt, Gloria; Sims, Darrell

    2005-08-01

    Dry sand and wet clay are the most frequently used materials for physical modeling of brittle deformation. We present a series of experiments that shows when the two materials can be used interchangeably, document the differences in deformation patterns and discuss how best to evaluate and apply results of physical models. Extension and shortening produce similar large-scale deformation patterns in dry sand and wet clay models, indicating that the two materials can be used interchangeably for analysis of gross deformation geometries. There are subtle deformation features that are significantly different: (1) fault propagation and fault linkage; (2) fault width, spacing and displacement; (3) extent of deformation zone; and (4) amount of folding vs. faulting. These differences are primarily due to the lower cohesion of sand and its larger grain size. If these features are of interest, the best practice would be to repeat the experiments with more than one material to ensure that rheological differences are not biasing results. Dry sand and wet clay produce very different results in inversion models; almost all faults are reactivated in wet clay, and few, if any, are significantly reactivated in sand models. Fault reactivation is attributed to high fluid pressure along the fault zone in the wet clay, a situation that may be analogous to many rocks. Sand inversion models may be best applied to areas where most faults experience little to no reactivation, while clay models best fit areas where most pre-existing normal faults are reactivated.

  13. Causes of differences in model and satellite tropospheric warming rates

    Science.gov (United States)

    Santer, Benjamin D.; Fyfe, John C.; Pallotta, Giuliana; Flato, Gregory M.; Meehl, Gerald A.; England, Matthew H.; Hawkins, Ed; Mann, Michael E.; Painter, Jeffrey F.; Bonfils, Céline; Cvijanovic, Ivana; Mears, Carl; Wentz, Frank J.; Po-Chedley, Stephen; Fu, Qiang; Zou, Cheng-Zhi

    2017-07-01

    In the early twenty-first century, satellite-derived tropospheric warming trends were generally smaller than trends estimated from a large multi-model ensemble. Because observations and coupled model simulations do not have the same phasing of natural internal variability, such decadal differences in simulated and observed warming rates invariably occur. Here we analyse global-mean tropospheric temperatures from satellites and climate model simulations to examine whether warming rate differences over the satellite era can be explained by internal climate variability alone. We find that in the last two decades of the twentieth century, differences between modelled and observed tropospheric temperature trends are broadly consistent with internal variability. Over most of the early twenty-first century, however, model tropospheric warming is substantially larger than observed; warming rate differences are generally outside the range of trends arising from internal variability. The probability that multi-decadal internal variability fully explains the asymmetry between the late twentieth and early twenty-first century results is low (between zero and about 9%). It is also unlikely that this asymmetry is due to the combined effects of internal variability and a model error in climate sensitivity. We conclude that model overestimation of tropospheric warming in the early twenty-first century is partly due to systematic deficiencies in some of the post-2000 external forcings used in the model simulations.

  14. VERIFICATION OF GEAR DYNAMIC MODEL IN DIFFERENT OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Grzegorz PERUŃ

    2014-09-01

    Full Text Available The article presents the results of verification of the drive system dynamic model with gear. Tests were carried out on the real object in different operating conditions. For the same assumed conditions were also carried out simulation studies. Comparison of the results obtained from those two series of tests helped determine the suitability of the model and verify the possibility of replacing experimental research by simulations with use of dynamic model.

  15. Atlas of Great Comets

    Science.gov (United States)

    Stoyan, Ronald; Dunlop, Storm

    2015-01-01

    Foreword; Using this book; Part I. Introduction: Cometary beliefs and fears; Comets in art; Comets in literature and poetry; Comets in science; Cometary science today; Great comets in antiquity; Great comets of the Middle Ages; Part II. The 30 Greatest Comets of Modern Times: The Great Comet of 1471; Comet Halley 1531; The Great Comet of 1556; The Great Comet of 1577; Comet Halley, 1607; The Great Comet of 1618; The Great Comet of 1664; Comet Kirch, 1680; Comet Halley, 1682; The Great Comet of 1744; Comet Halley, 1759; Comet Messier, 1769; Comet Flaugergues, 1811; Comet Halley, 1835; The Great March Comet of 1843; Comet Donati, 1858; Comet Tebbutt, 1861; The Great September Comet of 1882; The Great January Comet of 1910; Comet Halley, 1910; Comet Arend-Roland, 1956; Comet Ikeya-Seki, 1965; Comet Bennett, 1970; Comet Kohoutek, 1973-4; Comet West, 1976; Comet Halley, 1986; Comet Shoemaker-Levy 9, 1994; Comet Hyakutake, 1996; Comet Hale-Bopp, 1997; Comet McNaught, 2007; Part III. Appendices; Table of comet data; Glossary; References; Photo credits; Index.

  16. Pan evaporation modeling using six different heuristic computing methods in different climates of China

    Science.gov (United States)

    Wang, Lunche; Kisi, Ozgur; Zounemat-Kermani, Mohammad; Li, Hui

    2017-01-01

    Pan evaporation (Ep) plays important roles in agricultural water resources management. One of the basic challenges is modeling Ep using limited climatic parameters because there are a number of factors affecting the evaporation rate. This study investigated the abilities of six different soft computing methods, multi-layer perceptron (MLP), generalized regression neural network (GRNN), fuzzy genetic (FG), least square support vector machine (LSSVM), multivariate adaptive regression spline (MARS), adaptive neuro-fuzzy inference systems with grid partition (ANFIS-GP), and two regression methods, multiple linear regression (MLR) and Stephens and Stewart model (SS) in predicting monthly Ep. Long-term climatic data at various sites crossing a wide range of climates during 1961-2000 are used for model development and validation. The results showed that the models have different accuracies in different climates and the MLP model performed superior to the other models in predicting monthly Ep at most stations using local input combinations (for example, the MAE (mean absolute errors), RMSE (root mean square errors), and determination coefficient (R2) are 0.314 mm/day, 0.405 mm/day and 0.988, respectively for HEB station), while GRNN model performed better in Tibetan Plateau (MAE, RMSE and R2 are 0.459 mm/day, 0.592 mm/day and 0.932, respectively). The accuracies of above models ranked as: MLP, GRNN, LSSVM, FG, ANFIS-GP, MARS and MLR. The overall results indicated that the soft computing techniques generally performed better than the regression methods, but MLR and SS models can be more preferred at some climatic zones instead of complex nonlinear models, for example, the BJ (Beijing), CQ (Chongqing) and HK (Haikou) stations. Therefore, it can be concluded that Ep could be successfully predicted using above models in hydrological modeling studies.

  17. Making sense to modelers: Presenting UML class model differences in prose

    DEFF Research Database (Denmark)

    Störrle, Harald

    2013-01-01

    Understanding the difference between two models, such as different versions of a design, can be difficult. It is a commonly held belief in the model differencing community that the best way of presenting a model difference is by using graph or tree-based visualizations. We disagree and present an...

  18. Recent models for adaptive personality differences: a review

    Science.gov (United States)

    Dingemanse, Niels J.; Wolf, Max

    2010-01-01

    In this paper we review recent models that provide adaptive explanations for animal personalities: individual differences in behaviour (or suites of correlated behaviours) that are consistent over time or contexts. We start by briefly discussing patterns of variation in behaviour that have been documented in natural populations. In the main part of the paper we discuss models for personality differences that (i) explain animal personalities as adaptive behavioural responses to differences in state, (ii) investigate how feedbacks between state and behaviour can stabilize initial differences among individuals and (iii) provide adaptive explanations for animal personalities that are not based on state differences. Throughout, we focus on two basic questions. First, what is the basic conceptual idea underlying the model? Second, what are the key assumptions and predictions of the model? We conclude by discussing empirical features of personalities that have not yet been addressed by formal modelling. While this paper is primarily intended to guide empiricists through current adaptive theory, thereby stimulating empirical tests of these models, we hope it also inspires theoreticians to address aspects of personalities that have received little attention up to now. PMID:21078647

  19. Does style matter? : A cross-cultural study into the influence of differences in style dimensions on the persuasiveness of business newsletters in Great Britain and the Netherlands

    NARCIS (Netherlands)

    Hendriks, B.C.; Pair, R.G. le; Meurs, F. van; Korzilius, H.P.L.M.; Damen, S.

    2005-01-01

    An important consideration in the field of intercultural communication is the difference in communication styles between cultures. Gudykunst and Ting-Toomey (1988) distinguish four dimensions of communication styles: direct - indirect, instrumental – affective, personal – contextual and succinct – e

  20. Review of the UPFC Different Models in Recent Years

    Directory of Open Access Journals (Sweden)

    Mahmoud Zadehbagheri

    2014-05-01

    Full Text Available Unified Power Flow Controller (UPFC is one of the most intriguing and, potentially, the most versatile classes of Flexible AC Transmission Systems (FACTS devices. The UPFC is a device which can control simultaneously tree parameters line impedance, voltage, phase angle and dynamic compensation of AC power system. In order to analyse its true effects on power systems, it is important to model its constraints, due to various ratings and operating limits. This paper reviews on the different models of UPFC used in recent years and gives sets of information for each model of the UPFC in AC transmission. Then the different models are compared and features of each model are examined.

  1. Small distances, great differences: a case study involving the biomass of reef seaweeds and fishes on the coast of Paraíba, Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Cláudio Luís Santos Sampaio

    2007-06-01

    Full Text Available Shallow reefs on the coast of Paraíba state are poorly known. An analysis at three stations (Prot = protected; SP = semi-protected; Exp = exposed with different gradients of wave exposure revealed significant (p < 0.05 differences related to the biomass of seaweed (Prot = SP ≠ Exp. Station Exp with 9.97g (23% presented the lowest value followed by SP with 10.93 (25% and Prot with 22.55g (52%. The values suggest that the biomass of seaweeds is inversely related to the gradative higher exposure to waves. Additionally, a first record of Wrangelia argus (Montagne Montagne was made for the coast of Paraíba.

  2. Coupling hydrologic and infectious disease models to explain regional differences in schistosomiasis transmission in southwestern China.

    Science.gov (United States)

    Remais, Justin; Liang, Song; Spear, Robert C

    2008-04-01

    Rainfall-runoff models have become essential tools for conceptualizing and predicting the response of hydrologic processes to changing environments, but they have rarely been applied to challenges facing health scientists. Yet with their efficient parameterization and modest data requirements, they hold great promise for epidemiological application. A modeling analysis incorporating simple hydrologic constraints on transmission of the human parasite Schistosoma japonicum in southwestern China was conducted by coupling a lumped parameter rainfall-runoff model (IHACRES) with a delay-differential equation schistosomiasis transmission model modified to account for channel flows and on-field egg inactivation. Model predictions of prevalence and infection timing agree with observations in the region, which indicate that hydrological differences between sites can lead to pronounced differences in transmission. Channel flows are shown to be important in determining infection intensity and timing in modeled village populations. In the periodic absence of flow, overall transmission intensity is reduced among all modeled risk groups. However, the influence of hydrologic variability was greater on the cercarial stage of the parasite than the miracidial stage, due to the parasite ova's ability to survive dormant on fields between rain events. The predictive power gained from including hydrological data in epidemiological models can improve risk assessments for environmentally mediated diseases, under both long-term climate change scenarios and near-term weather fluctuations.

  3. Software Engineering Designs for Super-Modeling Different Versions of CESM Models using DART

    Science.gov (United States)

    Kluzek, Erik; Duane, Gregory; Tribbia, Joe; Vertenstein, Mariana

    2014-05-01

    The super-modeling approach connects different models together at run time in order to provide run time feedbacks between the models and thus synchronize the models. This method reduces model bias further than after-the-fact averaging of model outputs. We explore different designs to connect different configurations and versions of an IPCC class climate model - the Community Earth System Model (CESM). We build on the Data Assimilation Research Test-bed (DART) software to provide data assimilation from truth as well as to provide a software framework to link different model configurations together. We show a system building on DART that uses a Python script to do simple nudging between three versions of the atmosphere model in CESM (the Community Atmosphere Model (CAM) versions three, four and five).

  4. Green chromatography separation of analytes of greatly differing properties using a polyethylene glycol stationary phase and a low-toxic water-based mobile phase.

    Science.gov (United States)

    Šatínský, Dalibor; Brabcová, Ivana; Maroušková, Alena; Chocholouš, Petr; Solich, Petr

    2013-07-01

    A simple, rapid, and environmentally friendly HPLC method was developed and validated for the separation of four compounds (4-aminophenol, caffeine, paracetamol, and propyphenazone) with different chemical properties. A "green" mobile phase, employing water as the major eluent, was proposed and applied to the separation of analytes with different polarity on polyethylene glycol (PEG) stationary phase. The chromatography separation of all compounds and internal standard benzoic acid was performed using isocratic elution with a low-toxicity mobile phase consisting of 0.04% (v/v) triethylamine and water. HPLC separation was carried out using a PEG reversed-phase stationary phase Supelco Discovery HS PEG column (15 × 4 mm; particle size 3 μm) at a temperature of 30 °C and flow rate at 1.0 mL min(-1). The UV detector was set at 210 nm. In this study, a PEG stationary phase was shown to be suitable for the efficient isocratic separation of compounds that differ widely in hydrophobicity and acid-base properties, particularly 4-aminophenol (log P, 0.30), caffeine (log P, -0.25), and propyphenazone (log P, 2.27). A polar PEG stationary phase provided specific selectivity which allowed traditional chromatographic problems related to the separation of analytes with different polarities to be solved. The retention properties of the group of structurally similar substances (aromatic amines, phenolic compounds, and xanthine derivatives) were tested with different mobile phases. The proposed green chromatography method was successfully applied to the analysis of active substances and one degradation impurity (4-aminophenol) in commercial preparation. Under the optimum chromatographic conditions, standard calibration was carried out with good linearity correlation coefficients for all compounds in the range (0.99914-0.99997, n = 6) between the peak areas and concentration of compounds. Recovery of the sample preparation was in the range 100 ± 5% for all compounds

  5. Difference-Based Image Noise Modeling Using Skellam Distribution.

    Science.gov (United States)

    Hwang, Youngbae; Kim, Jun-Sik; Kweon, In So

    2012-07-01

    By the laws of quantum physics, pixel intensity does not have a true value, but should be a random variable. Contrary to the conventional assumptions, the distribution of intensity may not be an additive Gaussian. We propose to directly model the intensity difference and show its validity by an experimental comparison to the conventional additive model. As a model of the intensity difference, we present a Skellam distribution derived from the Poisson photon noise model. This modeling induces a linear relationship between intensity and Skellam parameters, while conventional variance computation methods do not yield any significant relationship between these parameters under natural illumination. The intensity-Skellam line is invariant to scene, illumination, and even most of camera parameters. We also propose practical methods to obtain the line using a color pattern and an arbitrary image under natural illumination. Because the Skellam parameters that can be obtained from this linearity determine a noise distribution for each intensity value, we can statistically determine whether any intensity difference is caused by an underlying signal difference or by noise. We demonstrate the effectiveness of this new noise model by applying it to practical applications of background subtraction and edge detection.

  6. Two velocity difference model for a car following theory

    Science.gov (United States)

    Ge, H. X.; Cheng, R. J.; Li, Z. P.

    2008-09-01

    In the light of the optimal velocity model, a two velocity difference model for a car-following theory is put forward considering navigation in modern traffic. To our knowledge, the model is an improvement over the previous ones theoretically, because it considers more aspects in the car-following process than others. Then we investigate the property of the model using linear and nonlinear analyses. The Korteweg-de Vries equation (for short, the KdV equation) near the neutral stability line and the modified Korteweg-de Vries equation (for short, the mKdV equation) around the critical point are derived by applying the reductive perturbation method. The traffic jam could be thus described by the KdV soliton and the kink-anti-kink soliton for the KdV equation and mKdV equation, respectively. Numerical simulations are made to verify the model, and good results are obtained with the new model.

  7. Digital Waveguides versus Finite Difference Structures: Equivalence and Mixed Modeling

    Directory of Open Access Journals (Sweden)

    Karjalainen Matti

    2004-01-01

    Full Text Available Digital waveguides and finite difference time domain schemes have been used in physical modeling of spatially distributed systems. Both of them are known to provide exact modeling of ideal one-dimensional (1D band-limited wave propagation, and both of them can be composed to approximate two-dimensional (2D and three-dimensional (3D mesh structures. Their equal capabilities in physical modeling have been shown for special cases and have been assumed to cover generalized cases as well. The ability to form mixed models by joining substructures of both classes through converter elements has been proposed recently. In this paper, we formulate a general digital signal processing (DSP-oriented framework where the functional equivalence of these two approaches is systematically elaborated and the conditions of building mixed models are studied. An example of mixed modeling of a 2D waveguide is presented.

  8. Complexity, accuracy and practical applicability of different biogeochemical model versions

    Science.gov (United States)

    Los, F. J.; Blaas, M.

    2010-04-01

    The construction of validated biogeochemical model applications as prognostic tools for the marine environment involves a large number of choices particularly with respect to the level of details of the .physical, chemical and biological aspects. Generally speaking, enhanced complexity might enhance veracity, accuracy and credibility. However, very complex models are not necessarily effective or efficient forecast tools. In this paper, models of varying degrees of complexity are evaluated with respect to their forecast skills. In total 11 biogeochemical model variants have been considered based on four different horizontal grids. The applications vary in spatial resolution, in vertical resolution (2DH versus 3D), in nature of transport, in turbidity and in the number of phytoplankton species. Included models range from 15 year old applications with relatively simple physics up to present state of the art 3D models. With all applications the same year, 2003, has been simulated. During the model intercomparison it has been noticed that the 'OSPAR' Goodness of Fit cost function (Villars and de Vries, 1998) leads to insufficient discrimination of different models. This results in models obtaining similar scores although closer inspection of the results reveals large differences. In this paper therefore, we have adopted the target diagram by Jolliff et al. (2008) which provides a concise and more contrasting picture of model skill on the entire model domain and for the entire period of the simulations. Correctness in prediction of the mean and the variability are separated and thus enhance insight in model functioning. Using the target diagrams it is demonstrated that recent models are more consistent and have smaller biases. Graphical inspection of time series confirms this, as the level of variability appears more realistic, also given the multi-annual background statistics of the observations. Nevertheless, whether the improvements are all genuine for the particular

  9. Using Decision Models to Enhance Investigations of Individual Differences in Cognitive Neuroscience

    Science.gov (United States)

    White, Corey N.; Curl, Ryan A.; Sloane, Jennifer F.

    2016-01-01

    There is great interest in relating individual differences in cognitive processing to activation of neural systems. The general process involves relating measures of task performance like reaction times or accuracy to brain activity to identify individual differences in neural processing. One limitation of this approach is that measures like reaction times can be affected by multiple components of processing. For instance, some individuals might have higher accuracy in a memory task because they respond more cautiously, not because they have better memory. Computational models of decision making, like the drift–diffusion model and the linear ballistic accumulator model, provide a potential solution to this problem. They can be fitted to data from individual participants to disentangle the effects of the different processes driving behavior. In this sense the models can provide cleaner measures of the processes of interest, and enhance our understanding of how neural activity varies across individuals or populations. The advantages of this model-based approach to investigating individual differences in neural activity are discussed with recent examples of how this method can improve our understanding of the brain–behavior relationship. PMID:26903896

  10. Using decision models to enhance investigations of individual differences in cognitive neuroscience

    Directory of Open Access Journals (Sweden)

    Corey N White

    2016-02-01

    Full Text Available There is great interest in relating individual differences in cognitive processing to activation of neural systems. The general process involves relating measures of task performance like reaction times or accuracy to brain activity to identify individual differences in neural processing. One limitation of this approach is that measures like reaction times can be affected by multiple components of processing. For instance, some individuals might have higher accuracy in a memory task because they respond more cautiously, not because they have better memory. Computational models of decision making, like the drift-diffusion model and the linear ballistic accumulator model, provide a potential solution to this problem. They can be fitted to data from individual participants to disentangle the effects of the different processes driving behavior. In this sense the models can provide cleaner measures of the processes of interest, and enhance our understanding of how neural activity varies across individuals or populations. The advantages of this model-based approach to investigating individual differences in neural activity are discussed with recent examples of how this method can improve our understanding of the brain-behavior relationship.

  11. Linear finite-difference bond graph model of an ionic polymer actuator

    Science.gov (United States)

    Bentefrit, M.; Grondel, S.; Soyer, C.; Fannir, A.; Cattan, E.; Madden, J. D.; Nguyen, T. M. G.; Plesse, C.; Vidal, F.

    2017-09-01

    With the recent growing interest for soft actuation, many new types of ionic polymers working in air have been developed. Due to the interrelated mechanical, electrical, and chemical properties which greatly influence the characteristics of such actuators, their behavior is complex and difficult to understand, predict and optimize. In light of this challenge, an original linear multiphysics finite difference bond graph model was derived to characterize this ionic actuation. This finite difference scheme was divided into two coupled subparts, each related to a specific physical, electrochemical or mechanical domain, and then converted into a bond graph model as this language is particularly suited for systems from multiple energy domains. Simulations were then conducted and a good agreement with the experimental results was obtained. Furthermore, an analysis of the power efficiency of such actuators as a function of space and time was proposed and allowed to evaluate their performance.

  12. Spatial modelling of Calanus finmarchicus and Calanus helgolandicus: parameter differences explain differences in biogeography

    Directory of Open Access Journals (Sweden)

    Robert John Wilson

    2016-09-01

    Full Text Available The North Atlantic copepods Calanus finmarchicus and C. helgolandicus are moving north in response to rising temperatures. Understanding the drivers of their relative geographic distributions is required in order to anticipate future changes. To explore this, we created a new spatially explicit stage-structured model of their populations throughout the North Atlantic. Recent advances in understanding Calanus biology, including U-shaped relationships between growth and fecundity and temperature, and a new model of diapause duration are incorporated in the model. Equations were identical for both species, but some parameters were species-specific. The model was parameterized using Continuous Plankton Recorder Survey data and tested using time series of abundance and fecundity. The geographic distributions of both species were reproduced by assuming that only known interspecific differences and a difference in the temperature influence on mortality exist. We show that differences in diapause capability are not necessary to explain why C. helgolandicus is restricted to the continental shelf. Smaller body size and higher overwinter temperatures likely make true diapause implausible for C. helgolandicus. Known differences were incapable of explaining why only C. helgolandicus exists southwest of the British Isles. Further, the fecundity of C. helgolandicus in the English Channel is much lower than we predict. We hypothesize that food quality is a key influence on the population dynamics of these species. The modelling framework presented can potentially be extended to further Calanus species.

  13. Error Probability Analysis of Free-Space Optical Links with Different Channel Model under Turbulent Condition

    CERN Document Server

    Barua, Bobby; Islam, Md Rezwan

    2012-01-01

    Free space optics (FSO) is a promising solution for the need to very high data rate point-to point communication. FSO communication technology became popular due to its large bandwidth potential, unlicensed spectrum, excellent security and quick and inexpensive setup. Unfortunately, atmospheric turbulence-induced fading is one of the main impairments affecting FSO communications. To design a high performance communication link for the atmospheric FSO channel, it is of great importance to characterize the channel with proper model. In this paper, the modulation format is Q-ary PPM across lasers, with intensity modulation and ideal photodetectors are assumed to investigate the most efficient PDF models for FSO communication under turbulent condition. The performance results are evaluated in terms of symbol error probability (SEP) for different type of channel model and the simulation results confirm the analytical findings.

  14. Estimation of whole lemon mass transfer parameters during hot air drying using different modelling methods

    Science.gov (United States)

    Torki-Harchegani, Mehdi; Ghanbarian, Davoud; Sadeghi, Morteza

    2015-08-01

    To design new dryers or improve existing drying equipments, accurate values of mass transfer parameters is of great importance. In this study, an experimental and theoretical investigation of drying whole lemons was carried out. The whole lemons were dried in a convective hot air dryer at different air temperatures (50, 60 and 75 °C) and a constant air velocity (1 m s-1). In theoretical consideration, three moisture transfer models including Dincer and Dost model, Bi- G correlation approach and conventional solution of Fick's second law of diffusion were used to determine moisture transfer parameters and predict dimensionless moisture content curves. The predicted results were then compared with the experimental data and the higher degree of prediction accuracy was achieved by the Dincer and Dost model.

  15. Tiling for Performance Tuning on Different Models of GPUs

    CERN Document Server

    Xu, Chang; Jenkins, Samantha

    2010-01-01

    The strategy of using CUDA-compatible GPUs as a parallel computation solution to improve the performance of programs has been more and more widely approved during the last two years since the CUDA platform was released. Its benefit extends from the graphic domain to many other computationally intensive domains. Tiling, as the most general and important technique, is widely used for optimization in CUDA programs. New models of GPUs with better compute capabilities have, however, been released, new versions of CUDA SDKs were also released. These updated compute capabilities must to be considered when optimizing using the tiling technique. In this paper, we implement image interpolation algorithms as a test case to discuss how different tiling strategies affect the program's performance. We especially focus on how the different models of GPUs affect the tiling's effectiveness by executing the same program on two different models of GPUs equipped testing platforms. The results demonstrate that an optimized tiling...

  16. Sex differences in animal models of psychiatric disorders

    Science.gov (United States)

    Kokras, N; Dalla, C

    2014-01-01

    Psychiatric disorders are characterized by sex differences in their prevalence, symptomatology and treatment response. Animal models have been widely employed for the investigation of the neurobiology of such disorders and the discovery of new treatments. However, mostly male animals have been used in preclinical pharmacological studies. In this review, we highlight the need for the inclusion of both male and female animals in experimental studies aiming at gender-oriented prevention, diagnosis and treatment of psychiatric disorders. We present behavioural findings on sex differences from animal models of depression, anxiety, post-traumatic stress disorder, substance-related disorders, obsessive–compulsive disorder, schizophrenia, bipolar disorder and autism. Moreover, when available, we include studies conducted across different stages of the oestrous cycle. By inspection of the relevant literature, it is obvious that robust sex differences exist in models of all psychiatric disorders. However, many times results are conflicting, and no clear conclusion regarding the direction of sex differences and the effect of the oestrous cycle is drawn. Moreover, there is a lack of considerable amount of studies using psychiatric drugs in both male and female animals, in order to evaluate the differential response between the two sexes. Notably, while in most cases animal models successfully mimic drug response in both sexes, test parameters and treatment-sensitive behavioural indices are not always the same for male and female rodents. Thus, there is an increasing need to validate animal models for both sexes and use standard procedures across different laboratories. Linked Articles This article is part of a themed section on Animal Models in Psychiatry Research. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-20 PMID:24697577

  17. An adaptation model for trabecular bone at different mechanical levels

    Directory of Open Access Journals (Sweden)

    Lv Linwei

    2010-07-01

    Full Text Available Abstract Background Bone has the ability to adapt to mechanical usage or other biophysical stimuli in terms of its mass and architecture, indicating that a certain mechanism exists for monitoring mechanical usage and controlling the bone's adaptation behaviors. There are four zones describing different bone adaptation behaviors: the disuse, adaptation, overload, and pathologic overload zones. In different zones, the changes of bone mass, as calculated by the difference between the amount of bone formed and what is resorbed, should be different. Methods An adaptation model for the trabecular bone at different mechanical levels was presented in this study based on a number of experimental observations and numerical algorithms in the literature. In the proposed model, the amount of bone formation and the probability of bone remodeling activation were proposed in accordance with the mechanical levels. Seven numerical simulation cases under different mechanical conditions were analyzed as examples by incorporating the adaptation model presented in this paper with the finite element method. Results The proposed bone adaptation model describes the well-known bone adaptation behaviors in different zones. The bone mass and architecture of the bone tissue within the adaptation zone almost remained unchanged. Although the probability of osteoclastic activation is enhanced in the overload zone, the potential of osteoblasts to form bones compensate for the osteoclastic resorption, eventually strengthening the bones. In the disuse zone, the disuse-mode remodeling removes bone tissue in disuse zone. Conclusions The study seeks to provide better understanding of the relationships between bone morphology and the mechanical, as well as biological environments. Furthermore, this paper provides a computational model and methodology for the numerical simulation of changes of bone structural morphology that are caused by changes of mechanical and biological

  18. Modelling AIDS epidemic and treatment with difference equations

    Directory of Open Access Journals (Sweden)

    Ramani A

    2004-01-01

    Full Text Available We propose two models for the description of the dynamics of an AIDS epidemic and of the effect of a combined-drugs AIDS treatment based on difference equations. We show that our interacting population model, despite its extreme simplicity, describes adequately the evolution of an AIDS epidemic. A cellular-automaton analogue of the discrete system of equations is presented as well. In the case of drug treatment, we identify two different regimes corresponding to efficient and inefficient medication. The effect of the discreteness of the equations is also studied.

  19. Modelling AIDS epidemic and treatment with difference equations

    Directory of Open Access Journals (Sweden)

    A. S. Carstea

    2004-07-01

    Full Text Available We propose two models for the description of the dynamics of an AIDS epidemic and of the effect of a combined-drugs AIDS treatment based on difference equations. We show that our interacting population model, despite its extreme simplicity, describes adequately the evolution of an AIDS epidemic. A cellular-automaton analogue of the discrete system of equations is presented as well. In the case of drug treatment, we identify two different regimes corresponding to efficient and inefficient medication. The effect of the discreteness of the equations is also studied.

  20. Differences in between-reinforcer value modulate the selective-value effect in great apes (Pan troglodytes, P. Paniscus, Gorilla gorilla, Pongo abelii).

    Science.gov (United States)

    Sánchez-Amaro, Alejandro; Peretó, Mar; Call, Josep

    2016-02-01

    We investigated how apes allocated their choices between 2 food options that varied in terms of their quantity and quality. Experiment 1 tested whether subjects preferred an AB option over an A option, where the A item is preferred to the B item (e.g., apple + carrot vs. apple). Additionally, we tested whether the length of the intertrial interval (ITI) affected subjects' choices. Five orangutans, 4 gorillas, 7 bonobos, and 10 chimpanzees received 3 types of trials: preference (A vs. B), quantity (AA vs. A), and mixed (AB vs. A where A is the preferred food). We used 3 food items that substantially differed in terms of preference (carrots, apples, and pellets). Subjects showed no overall preference for the mixed option (AB) compared with the single option (A), even though they showed clear preferences during both the preference and quantity trials. The intertrial length had no effect on choice behavior. Experiment 2 further explored apes' choices by using 3 highly preferred food items (bananas, grapes, and pellets) in 6 orangutans, 4 gorillas, 8 bonobos, and 18 chimpanzees. Unlike the results of Experiment 1, apes generally chose the mixed option. Our results indicated that apes did not show a general "selective-value" effect but chose depending on the relative value of the food items involved. Subjects were more likely to select the mixed over the single option when (a) the mixed option was composed of items that were closer in value and (b) they were compared against the less valuable item forming the mixed option.

  1. Gender Differences in Animal Models of Posttraumatic Stress Disorder

    Directory of Open Access Journals (Sweden)

    Hagit Cohen

    2011-01-01

    Full Text Available Epidemiological studies report higher prevalence rates of stress-related disorders such as acute stress disorder and post-traumatic stress disorder (PTSD in women than in men following exposure to trauma. It is still not clear whether this greater prevalence in woman reflects a greater vulnerability to stress-related psychopathology. A number of individual and trauma-related characteristics have been hypothesized to contribute to these gender differences in physiological and psychological responses to trauma, differences in appraisal, interpretation or experience of threat, coping style or social support. In this context, the use of an animal model for PTSD to analyze some of these gender-related differences may be of particular utility. Animal models of PTSD offer the opportunity to distinguish between biological and socio-cultural factors, which so often enter the discussion about gender differences in PTSD prevalence.

  2. Regional groundwater-flow model of the Lake Michigan Basin in support of Great Lakes Basin water availability and use studies

    Science.gov (United States)

    Feinstein, D.T.; Hunt, R.J.; Reeves, H.W.

    2010-01-01

    A regional groundwater-flow model of the Lake Michigan Basin and surrounding areas has been developed in support of the Great Lakes Basin Pilot project under the U.S. Geological Survey's National Water Availability and Use Program. The transient 2-million-cell model incorporates multiple aquifers and pumping centers that create water-level drawdown that extends into deep saline waters. The 20-layer model simulates the exchange between a dense surface-water network and heterogeneous glacial deposits overlying stratified bedrock of the Wisconsin/Kankakee Arches and Michigan Basin in the Lower and Upper Peninsulas of Michigan; eastern Wisconsin; northern Indiana; and northeastern Illinois. The model is used to quantify changes in the groundwater system in response to pumping and variations in recharge from 1864 to 2005. Model results quantify the sources of water to major pumping centers, illustrate the dynamics of the groundwater system, and yield measures of water availability useful for water-resources management in the region. This report is a complete description of the methods and datasets used to develop the regional model, the underlying conceptual model, and model inputs, including specified values of material properties and the assignment of external and internal boundary conditions. The report also documents the application of the SEAWAT-2000 program for variable-density flow; it details the approach, advanced methods, and results associated with calibration through nonlinear regression using the PEST program; presents the water-level, drawdown, and groundwater flows for various geographic subregions and aquifer systems; and provides analyses of the effects of pumping from shallow and deep wells on sources of water to wells, the migration of groundwater divides, and direct and indirect groundwater discharge to Lake Michigan. The report considers the role of unconfined conditions at the regional scale as well as the influence of salinity on groundwater flow

  3. Different radiation impedance models for finite porous materials

    DEFF Research Database (Denmark)

    Nolan, Melanie; Jeong, Cheol-Ho; Brunskog, Jonas;

    2015-01-01

    coupled to the transfer matrix method (TMM). These methods are found to yield comparable results when predicting the Sabine absorption coefficients of finite porous materials. Discrepancies with measurement results can essentially be explained by the unbalance between grazing and non-grazing sound field...... the infinite case. Thus, in order to predict the Sabine absorption coefficients of finite porous samples, one can incorporate models of the radiation impedance. In this study, different radiation impedance models are compared with two experimental examples. Thomasson’s model is compared to Rhazi’s method when...

  4. Sex Differences in Animal Models: Focus on Addiction.

    Science.gov (United States)

    Becker, Jill B; Koob, George F

    2016-04-01

    The purpose of this review is to discuss ways to think about and study sex differences in preclinical animal models. We use the framework of addiction, in which animal models have excellent face and construct validity, to illustrate the importance of considering sex differences. There are four types of sex differences: qualitative, quantitative, population, and mechanistic. A better understanding of the ways males and females can differ will help scientists design experiments to characterize better the presence or absence of sex differences in new phenomena that they are investigating. We have outlined major quantitative, population, and mechanistic sex differences in the addiction domain using a heuristic framework of the three established stages of the addiction cycle: binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation. Female rats, in general, acquire the self-administration of drugs and alcohol more rapidly, escalate their drug taking with extended access more rapidly, show more motivational withdrawal, and (where tested in animal models of "craving") show greater reinstatement. The one exception is that female rats show less motivational withdrawal to alcohol. The bases for these quantitative sex differences appear to be both organizational, in that estradiol-treated neonatal animals show the male phenotype, and activational, in that the female phenotype depends on the effects of gonadal hormones. In animals, differences within the estrous cycle can be observed but are relatively minor. Such hormonal effects seem to be most prevalent during the acquisition of drug taking and less influential once compulsive drug taking is established and are linked largely to progesterone and estradiol. This review emphasizes not only significant differences in the phenotypes of females and males in the domain of addiction but emphasizes the paucity of data to date in our understanding of those differences. Copyright © 2016 by The American Society

  5. Gender obesity inequities are huge but differ greatly according to environment and socio-economics in a North African setting: a national cross-sectional study in Tunisia.

    Directory of Open Access Journals (Sweden)

    Jalila El Ati

    Full Text Available INTRODUCTION: Southern Mediterranean countries have experienced a marked increase in the prevalence of obesity whose consequences for gender related health inequities have been little studied. We assessed gender obesity inequalities and their environmental and socio-economic modifiers among Tunisian adults. METHODS: Cross-sectional survey in 2005; national, 3 level random cluster sample of 35-70 years Tunisians (women: n = 2964, men: n = 2379. Overall adiposity was assessed by BMI = weight(kg/height(m(2 and obesity was BMI≥30, WHtR = waist circumference to height ratio defined abdominal obesity as WHtR≥0.6. Gender obesity inequality measure was women versus men Prevalence Proportion Odds-Ratio (OR; models featuring gender x covariate interaction assessed variation of gender obesity inequalities with area (urban versus rural, age, marital status or socio-economic position (profession, education, household income proxy. RESULTS: BMI was much higher among women (28.4(0.2 versus men (25.3(0.1, P<0.0001 as was obesity (37.0% versus 13.3%, OR = 3.8[3.1-7.4], P<0.0001 and abdominal obesity (42.6% versus 15.6%, 4.0[3.3-4.8], P<0.0001. Gender obesity inequalities (women versus men adjusted OR were higher in urban (OR = 3.3[1.3-8.7] than rural (OR = 2.0[0.7-5.5] areas. These gender obesity inequalities were lower for subjects with secondary education or more (OR = 3.3[1.3-8.6], than among those with no schooling (OR = 6.9[2.0-23.3]. They were also lower for those with upper/intermediate profession (OR = 1.4[0.5-4.3] or even employees/workers OR = 2.3[1.0-5.4] than those not professionaly active at all (OR = 3.3[1.3-8.6]. Similar results were observed for addominal obesity. CONCLUSION: The huge overall gender obesity inequities (women much more corpulent than men were higher in urban settings, but lower among subjects of higher education and professional activity. Reasons for gender inequalities in

  6. Great attractor really a great wall

    Energy Technology Data Exchange (ETDEWEB)

    Stebbins, A.; Turner, M.S.

    1988-11-01

    Some of the cosmological consequences are discussed of a late time phase transition which produces light domain walls. The observed peculiar velocity field of the Universe and the observed isotropy of the microwave background radiation severely constrain the wall surface density in such a scenario. The most interesting consequence of such a phase transition is the possibility that the local, coherent streaming motion reported by the Seven Samurai could be explained by the repulsive effect of a relic domain wall with the Hubble volume (the Great Wall).

  7. Discrimination and Skill Differences in an Equilibrium Search Model

    OpenAIRE

    Bowlus, Audra J.; Eckstein, Zvi

    1998-01-01

    In this paper, we analyse an equilibrium search model with three sources for wage and unemployment differentials among workers with the same (observed) human capital but different appearance (race): unobserved productivity (skill), search intensities and discrimination (Becker 1957) due to an appearance-based employer disutility factor. Because these sources affect the earnings distributions differently, empirical identification of these potential sources for the explanation of wage and unemp...

  8. Meridional Winds derived from ionosonde measurements: comparison of different models

    Science.gov (United States)

    Katamzi, Zama; Bosco Habarulema, John; Aruliah, Anasuya

    2016-07-01

    Thermospheric meridional winds are derived from ionospheric F2 region peak parameters (i.e. F2 maximum density, NmF2, and F2 peak height, hmF2) obtained using South African ionosonde for solar maximum (2001 and 2014) and solar minimum (2009). The study uses several different techniques and models to investigate the climatology behaviour of the winds in order to understand wind variability over South Africa. Detailed solar cycle, seasonal and diurnal trends will help establish how the winds influence ionospheric behaviour at this latitude. Comparisons of ionosonde derived neutral winds with empirical and numerical models such as the Coupled Middle Atmosphere Thermosphere Model (CMAT2) and Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) are important to understand the validity of theoretical and empirical models.

  9. Finite difference methods for coupled flow interaction transport models

    Directory of Open Access Journals (Sweden)

    Shelly McGee

    2009-04-01

    Full Text Available Understanding chemical transport in blood flow involves coupling the chemical transport process with flow equations describing the blood and plasma in the membrane wall. In this work, we consider a coupled two-dimensional model with transient Navier-Stokes equation to model the blood flow in the vessel and Darcy's flow to model the plasma flow through the vessel wall. The advection-diffusion equation is coupled with the velocities from the flows in the vessel and wall, respectively to model the transport of the chemical. The coupled chemical transport equations are discretized by the finite difference method and the resulting system is solved using the additive Schwarz method. Development of the model and related analytical and numerical results are presented in this work.

  10. Coalescence of liquid drops: Different models versus experiment

    KAUST Repository

    Sprittles, J. E.

    2012-01-01

    The process of coalescence of two identical liquid drops is simulated numerically in the framework of two essentially different mathematical models, and the results are compared with experimental data on the very early stages of the coalescence process reported recently. The first model tested is the "conventional" one, where it is assumed that coalescence as the formation of a single body of fluid occurs by an instant appearance of a liquid bridge smoothly connecting the two drops, and the subsequent process is the evolution of this single body of fluid driven by capillary forces. The second model under investigation considers coalescence as a process where a section of the free surface becomes trapped between the bulk phases as the drops are pressed against each other, and it is the gradual disappearance of this "internal interface" that leads to the formation of a single body of fluid and the conventional model taking over. Using the full numerical solution of the problem in the framework of each of the two models, we show that the recently reported electrical measurements probing the very early stages of the process are better described by the interface formation/disappearance model. New theory-guided experiments are suggested that would help to further elucidate the details of the coalescence phenomenon. As a by-product of our research, the range of validity of different "scaling laws" advanced as approximate solutions to the problem formulated using the conventional model is established. © 2012 American Institute of Physics.

  11. Great Lakes Teacher's Guide.

    Science.gov (United States)

    Reid, Ron

    The Great Lakes are one of the world's greatest reservoirs of fresh water, the foundation of Ontario's economic development, a primary force in ecological systems, and a base for pleasure and recreation. They are also a magnificent resource for the teachers of Ontario. Study of the Great Lakes can bring to life the factors that shape the ecology…

  12. Great Principles of Computing

    OpenAIRE

    Denning, Peter J.

    2008-01-01

    The Great Principles of Computing is a framework for understanding computing as a field of science. The website ...April 2008 (Rev. 8/31/08) The Great Principles of Computing is a framework for understanding computing as a field of science.

  13. Bottom Fixed Platform Dynamics Models Assessing Surface Ice Interactions for Transitional Depth Structures in the Great Lakes: FAST8 – IceDyn

    Energy Technology Data Exchange (ETDEWEB)

    Karr, Dale G. [Univ. of Michigan, Ann Arbor, MI (United States); Yu, Bingbin [Principle Power, Inc., Emeryville, CA (United States); Sirnivas, Senu [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-04-01

    To create long-term solutions for offshore wind turbines in a variety of environmental conditions, CAE tools are needed to model the design-driving loads that interact with an offshore wind turbine system during operation. This report describes our efforts in augmenting existing CAE tools used for offshore wind turbine analysis with a new module that can provide simulation capabilities for ice loading on the system. This augmentation was accomplished by creating an ice-loading module coupled to FAST8, the CAE tool maintained by the NREL for simulating land-based and offshore wind turbine dynamics. The new module includes both static and dynamic ice loading that can be applied during a dynamic simulation of the response of an offshore wind turbine. The ice forces can be prescribed, or influenced by the structure’s compliant response, or by the dynamics of both the structure and the ice floe. The new module covers ice failure modes of spalling, buckling, crushing, splitting, and bending. The supporting structure of wind turbines can be modeled as a vertical or sloping form at the waterline. The Inward Battered Guide Structure (IBGS) foundation designed by Keystone Engineering for the Great Lakes was used to study the ice models coupled to FAST8. The IBGS foundation ice loading simulations in FAST8 were compared to the baseline simulation case without ice loading. The ice conditions reflecting those from Lake Huron at Port Huron and Lake Michigan at North Manitou were studied under near rated wind speed of 12 m/s for the NREL 5-MW reference turbine. Simulations were performed on ice loading models 1 through 4 and ice model 6 with their respective sub-models. The purpose of ice model 5 is to investigate ice loading on sloping structures such as ice-cones on a monopile and is not suitable for multi-membered jacketed structures like the IBGS foundation. The key response parameters from the simulations, shear forces and moments from the tower base and IBGS foundation

  14. Modeling of Brain Shift Phenomenon for Different Craniotomies and Solid Models

    Directory of Open Access Journals (Sweden)

    Alvaro Valencia

    2012-01-01

    Full Text Available This study investigates the effects of different solid models on predictions of brain shift for three craniotomies. We created a generic 3D brain model based on healthy human brain and modeled the brain parenchyma as single continuum and constrained by a practically rigid skull. We have used elastic model, hyperelastic 1st, 2nd, and 3rd Ogden models, and hyperelastic Mooney-Rivlin with 2- and 5-parameter models. A pressure on the brain surface at craniotomy region was applied to load the model. The models were solved with the finite elements package ANSYS. The predictions on stress and displacements were compared for three different craniotomies. The difference between the predictions of elastic solid model and a hyperelastic Ogden solid model of maximum brain displacement and maximum effective stress is relevant.

  15. Modelling financial markets with agents competing on different time scales and with different amount of information

    Science.gov (United States)

    Wohlmuth, Johannes; Andersen, Jørgen Vitting

    2006-05-01

    We use agent-based models to study the competition among investors who use trading strategies with different amount of information and with different time scales. We find that mixing agents that trade on the same time scale but with different amount of information has a stabilizing impact on the large and extreme fluctuations of the market. Traders with the most information are found to be more likely to arbitrage traders who use less information in the decision making. On the other hand, introducing investors who act on two different time scales has a destabilizing effect on the large and extreme price movements, increasing the volatility of the market. Closeness in time scale used in the decision making is found to facilitate the creation of local trends. The larger the overlap in commonly shared information the more the traders in a mixed system with different time scales are found to profit from the presence of traders acting at another time scale than themselves.

  16. Using Different Models of Second-Language Teaching

    Science.gov (United States)

    Papalia, Anthony

    1975-01-01

    The teaching profession is encouraged to retreat from the search for one method of instruction and to recognize that there are many factors which lead to success in modern language learning. Several models offering different approaches for organizing classroom instruction are suggested. (Author/PMP)

  17. Exploring Sex Differences in Worry with a Cognitive Vulnerability Model

    Science.gov (United States)

    Zalta, Alyson K.; Chambless, Dianne L.

    2008-01-01

    A multivariate model was developed to examine the relative contributions of mastery, stress, interpretive bias, and coping to sex differences in worry. Rumination was incorporated as a second outcome variable to test the specificity of these associations. Participants included two samples of undergraduates totaling 302 men and 379 women. A path…

  18. How different are language models and word clouds?

    NARCIS (Netherlands)

    Kaptein, R.; Hiemstra, D.; Kamps, J.

    2010-01-01

    Word clouds are a summarised representation of a document’s text, similar to tag clouds which summarise the tags assigned to documents. Word clouds are similar to language models in the sense that they represent a document by its word distribution. In this paper we investigate the differences

  19. How Different are Language Models and Word Clouds?

    NARCIS (Netherlands)

    Kaptein, Rianne; Hiemstra, Djoerd; Kamps, Jaap

    Word clouds are a summarised representation of a document’s text, similar to tag clouds which summarise the tags assigned to documents. Word clouds are similar to language models in the sense that they represent a document by its word distribution. In this paper we investigate the differences

  20. How different are language models and word clouds?

    NARCIS (Netherlands)

    Kaptein, R.; Hiemstra, D.; Kamps, J.

    2010-01-01

    Word clouds are a summarised representation of a document’s text, similar to tag clouds which summarise the tags assigned to documents. Word clouds are similar to language models in the sense that they represent a document by its word distribution. In this paper we investigate the differences betwee

  1. How Different are Language Models and Word Clouds?

    NARCIS (Netherlands)

    Kaptein, Rianne; Hiemstra, Djoerd; Kamps, Jaap

    2010-01-01

    Word clouds are a summarised representation of a document’s text, similar to tag clouds which summarise the tags assigned to documents. Word clouds are similar to language models in the sense that they represent a document by its word distribution. In this paper we investigate the differences betwee

  2. A generic method for automatic translation between input models for different versions of simulation codes

    Energy Technology Data Exchange (ETDEWEB)

    Serfontein, Dawid E., E-mail: Dawid.Serfontein@nwu.ac.za [School of Mechanical and Nuclear Engineering, North West University (PUK-Campus), PRIVATE BAG X6001 (Internal Post Box 360), Potchefstroom 2520 (South Africa); Mulder, Eben J. [School of Mechanical and Nuclear Engineering, North West University (South Africa); Reitsma, Frederik [Calvera Consultants (South Africa)

    2014-05-01

    A computer code was developed for the semi-automatic translation of input models for the VSOP-A diffusion neutronics simulation code to the format of the newer VSOP 99/05 code. In this paper, this algorithm is presented as a generic method for producing codes for the automatic translation of input models from the format of one code version to another, or even to that of a completely different code. Normally, such translations are done manually. However, input model files, such as for the VSOP codes, often are very large and may consist of many thousands of numeric entries that make no particular sense to the human eye. Therefore the task, of for instance nuclear regulators, to verify the accuracy of such translated files can be very difficult and cumbersome. This may cause translation errors not to be picked up, which may have disastrous consequences later on when a reactor with such a faulty design is built. Therefore a generic algorithm for producing such automatic translation codes may ease the translation and verification process to a great extent. It will also remove human error from the process, which may significantly enhance the accuracy and reliability of the process. The developed algorithm also automatically creates a verification log file which permanently record the names and values of each variable used, as well as the list of meanings of all the possible values. This should greatly facilitate reactor licensing applications.

  3. Diagnosing the Local Land-Atmosphere Coupling (LoCo) in Models and Observations: A Study of Dry/Wet Extremes in the U. S. Southern Great Plains

    Science.gov (United States)

    Santanello, J. A.; Peters-Lidard, C. D.; Kumar, S.; Dong, X.; Kennedy, A. D.

    2010-12-01

    Land-atmosphere interactions play a critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface temperature and moisture states. The degree of coupling between the land surface and PBL in numerical weather prediction and climate models remains largely unexplored and undiagnosed due to the complex interactions and feedbacks present across a range of scales. Further, uncoupled systems or experiments (e.g., the Project for Intercomparison of Land Parameterization Schemes, PILPS) may lead to inaccurate water and energy cycle process understanding by neglecting feedback processes such as PBL-top entrainment. In this study, a framework for diagnosing local land-atmosphere coupling (LoCo) is presented using a coupled mesoscale model with a suite of PBL and land surface model (LSM) options along with observations during the summers of 2006/7 in the U.S. Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to NASA's Land Information System (LIS), which provides a flexible and high-resolution representation and initialization of land surface physics and states. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation are examined for the dry/wet extremes of this region, along with the sensitivity of PBL-LSM coupling to perturbations in soil moisture. As such, this methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which is serving as a testbed for LoCo experiments to evaluate coupling diagnostics within the community.

  4. Excess seawater nutrients, enlarged algal symbiont densities and bleaching sensitive reef locations: 2. A regional-scale predictive model for the Great Barrier Reef, Australia.

    Science.gov (United States)

    Wooldridge, Scott A; Heron, Scott F; Brodie, Jon E; Done, Terence J; Masiri, Itsara; Hinrichs, Saskia

    2017-01-15

    A spatial risk assessment model is developed for the Great Barrier Reef (GBR, Australia) that helps identify reef locations at higher or lower risk of coral bleaching in summer heat-wave conditions. The model confirms the considerable benefit of discriminating nutrient-enriched areas that contain corals with enlarged (suboptimal) symbiont densities for the purpose of identifying bleaching-sensitive reef locations. The benefit of the new system-level understanding is showcased in terms of: (i) improving early-warning forecasts of summer bleaching risk, (ii) explaining historical bleaching patterns, (iii) testing the bleaching-resistant quality of the current marine protected area (MPA) network (iv) identifying routinely monitored coral health attributes, such as the tissue energy reserves and skeletal growth characteristics (viz. density and extension rates) that correlate with bleaching resistant reef locations, and (v) targeting region-specific water quality improvement strategies that may increase reef-scale coral health and bleaching resistance. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  5. Multiple flux difference effect in the lattice hydrodynamic model

    Institute of Scientific and Technical Information of China (English)

    Wang Tao; Gao Zi-You; Zhao Xiao-Mei

    2012-01-01

    Considering the effect of multiple flux difference,an extended lattice model is proposed to improve the stability of traffic flow.The stability condition of the new model is obtained by using linear stability theory.The theoretical analysis result shows that considering the flux difference effect ahead can stabilize traffic flow.The nonlinear analysis is also conducted by using a reductive perturbation method.The modified KdV (mKdV) equation near the critical point is derived and the kink-antikink solution is obtained from the mKdV equation.Numerical simulation results show that the multiple flux difference effect can suppress the traffic jam considerably,which is in line with the analytical result.

  6. Statistical Modeling of Robotic Random Walks on Different Terrain

    Science.gov (United States)

    Naylor, Austin; Kinnaman, Laura

    Issues of public safety, especially with crowd dynamics and pedestrian movement, have been modeled by physicists using methods from statistical mechanics over the last few years. Complex decision making of humans moving on different terrains can be modeled using random walks (RW) and correlated random walks (CRW). The effect of different terrains, such as a constant increasing slope, on RW and CRW was explored. LEGO robots were programmed to make RW and CRW with uniform step sizes. Level ground tests demonstrated that the robots had the expected step size distribution and correlation angles (for CRW). The mean square displacement was calculated for each RW and CRW on different terrains and matched expected trends. The step size distribution was determined to change based on the terrain; theoretical predictions for the step size distribution were made for various simple terrains. It's Dr. Laura Kinnaman, not sure where to put the Prefix.

  7. RNA and protein 3D structure modeling: similarities and differences.

    Science.gov (United States)

    Rother, Kristian; Rother, Magdalena; Boniecki, Michał; Puton, Tomasz; Bujnicki, Janusz M

    2011-09-01

    In analogy to proteins, the function of RNA depends on its structure and dynamics, which are encoded in the linear sequence. While there are numerous methods for computational prediction of protein 3D structure from sequence, there have been very few such methods for RNA. This review discusses template-based and template-free approaches for macromolecular structure prediction, with special emphasis on comparison between the already tried-and-tested methods for protein structure modeling and the very recently developed "protein-like" modeling methods for RNA. We highlight analogies between many successful methods for modeling of these two types of biological macromolecules and argue that RNA 3D structure can be modeled using "protein-like" methodology. We also highlight the areas where the differences between RNA and proteins require the development of RNA-specific solutions.

  8. Differences in Liver Injury and Trophoblastic Mitochondrial Damage in Different Preeclampsia-like Mouse Models

    Institute of Scientific and Technical Information of China (English)

    Yi-Wei Han; Zi Yang; Xiao-Yan Ding; Huan Yu

    2015-01-01

    Background:Preeclampsia is a multifactorial disease during pregnancy.Dysregulated lipid metabolism may be related to some preeclampsia.We investigated the relationship between triglycerides (TGs) and liver injury in different preeclampsia-like mouse models and their potential common pathways.Methods:Preeclampsia-like models (Nw-nitro-L-arginine-methyl ester [L-NAME],lipopolysaccharide [LPS],apolipoprotein C-Ⅲ [Apo] transgnic mice + L-NAME,β2 glycoprotein Ⅰ [βGPI]) were used in four experimental groups:L-NAME (LN),LPS,Apo-LN and βGPI,respectively,and controls received saline (LN-C,LPS-C,Apo-C,βGPI-C).The first three models were established in preimplantation (PI),early-,mid-and late-gestation (EG,MG and LG).βGPI and controls were injected before implantation.Mean arterial pressure (MAP),24-hour urine protein,placental and fetal weight,serum TGs,total cholesterol (TC) and pathologic liver and trophocyte changes were assessed.Results:MAP and proteinuria were significantly increased in the experimental groups.Placenta and fetal weight in PI,EP and MP subgroups were significantly lower than LP.Serum TGs significantly increased in most groups but controls.TC was not different between experimental and control groups.Spotty hepatic cell necrosis was observed in PI,EG,MG in LN,Apo-LN and βGPI,but no morphologic changes were observed in the LPS group.Similar trophoblastic mitochondrial damage was observed in every experimental group.Conclusions:Earlier preeclampsia onset causes a higher MAP and urine protein level,and more severe placental and fetal damage.Preeclampsia-like models generated by varied means lead to different changes in lipid metabolism and associated with liver injury.Trophoblastic mitochondrial damage may be the common terminal pathway in different preeclampsia-like models.

  9. Great Lakes' regional climate regimes

    Science.gov (United States)

    Kravtsov, Sergey; Sugiyama, Noriyuki; Roebber, Paul

    2016-04-01

    We simulate the seasonal cycle of the Great Lakes' water temperature and lake ice using an idealized coupled lake-atmosphere-ice model. Under identical seasonally varying boundary conditions, this model exhibits more than one seasonally varying equilibrium solutions, which we associate with distinct regional climate regimes. Colder/warmer regimes are characterized by abundant/scarce amounts of wintertime ice and cooler/warmer summer temperatures, respectively. These regimes are also evident in the observations of the Great Lakes' climate variability over recent few decades, and are found to be most pronounced for Lake Superior, the deepest of the Great Lakes, consistent with model predictions. Multiple climate regimes of the Great Lakes also play a crucial role in the accelerated warming of the lakes relative to the surrounding land regions in response to larger-scale global warming. We discuss the physical origin and characteristics of multiple climate regimes over the lakes, as well as their implications for a longer-term regional climate variability.

  10. Performance Analysis of MANET Routing Protocols in Different Mobility Models

    Directory of Open Access Journals (Sweden)

    Anuj K. Gupta

    2013-05-01

    Full Text Available A mobile ad-hoc network (MANET is basically called as a network without any central administration or fixed infrastructure. It consists of a number of mobile nodes that use to send data packets through a wireless medium. There is always a need of a good routing protocol in order to establish the connection between mobile nodes since they possess the property of dynamic changing topology. Further, in all the existing routing protocols, mobility of a node has always been one of the important characteristics in determining the overall performance of the ad hoc network. Thus, it is essential to know about various mobility models and their effect on the routing protocols. In this paper, we have made an attempt to compare different mobility models and provide an overview of their current research status. The main focus is on Random Mobility Models and Group Mobility Models. Firstly, we present a survey of the characteristics, drawbacks and research challenges of mobility modeling. At the last we present simulation results that illustrate the importance of choosing a mobility model in the simulation of an ad hoc network protocol. Also, we illustrate how the performance results of an ad hoc network protocol drastically change as a result of changing the mobility model simulated.

  11. Symbols in the Great Gatsby

    Institute of Scientific and Technical Information of China (English)

    徐琰

    2016-01-01

    This paper analyzes the symbols in the book"The Great Gatsby" which include some particular places, objects, characters, settings and actions. These symbols are considered to have values different from what they are symbolized and most of them are connected to the theme of the novel-the corruption of the American dream.

  12. Comparison of simulated forest soil response to acid deposition reduction with two models of differing complexity

    Directory of Open Access Journals (Sweden)

    J. P. Mol-Dijkstra

    1998-01-01

    Full Text Available Great effort has been dedicated to developing soil acidification models for use on different scales. This paper focuses on the changes in model performance of a site scale soil acidification model (NUCSAM and a national to European scale soil acidification model (SMART 2. This was done to gain insight into the effects of model simplification. Because these models aim to predict the response to reduction in acid deposition, these models must be tested under such circumstances. A straightforward calibration and validation of the regional model, however, is hampered by lack of observations over a sufficient time period. Consequently, NUCSAM was calibrated and validated to a manipulation experiment involving reduced acid deposition in the Speuld forest, the Netherlands. SMART 2 was then used with calibrated input data from NUCSAM. The acid deposition was excluded by a roof beneath the canopy. The roofed area consists of a plot receiving pristine deposition levels of nitrogen (N and sulphur (S and a control plot receiving ambient deposition. NUCSAM was calibrated on the ambient plot, followed by a validation of both models on the pristine plot. Both models predicted soil solution concentrations within the 95% confidence interval of the observed responses for both the ambient plot and the pristine plot at 90 cm depth. Despite the large seasonal and vertical (spatial variation in soil solution chemistry, the trends in annual flux- weighted soil solution chemistry, as predicted by SMART 2 and NUCSAM, corresponded well.The annual leaching fluxes below the root zone were also similar although differences exist for the topsoil. For the topsoil, NUCSAM simulated the nutrients and acid related constituents better than SMART 2. Both models overestimated the ammonium (NH4 concentration at 10 cm depth. SMART 2 underestimated calcium and magnesium (BC2+ concentration at 10 depth, whereas NUCSAM overestimated BC2+ concentration at 90 cm depth. NUCSAM predicted

  13. Biomechanical modeling of eye trauma for different orbit anthropometries.

    Science.gov (United States)

    Weaver, Ashley A; Loftis, Kathryn L; Duma, Stefan M; Stitzel, Joel D

    2011-04-29

    In military, automotive, and sporting safety, there is concern over eye protection and the effects of facial anthropometry differences on risk of eye injury. The objective of this study is to investigate differences in orbital geometry and analyze their effect on eye impact injury. Clinical measurements of the orbital aperture, brow protrusion angle, eye protrusion, and the eye location within the orbit were used to develop a matrix of simulations. A finite element (FE) model of the orbit was developed from a computed tomography (CT) scan of an average male and transformed to model 27 different anthropometries. Impacts were modeled using an eye model incorporating lagrangian-eulerian fluid flow for the eye, representing a full eye for evaluation of omnidirectional impact and interaction with the orbit. Computational simulations of a Little League (CD25) baseball impact at 30.1m/s were conducted to assess the effect of orbit anthropometry on eye injury metrics. Parameters measured include stress and strain in the corneoscleral shell, internal dynamic eye pressure, and contact forces between the orbit, eye, and baseball. The location of peak stresses and strains was also assessed. Main effects and interaction effects identified in the statistical analysis illustrate the complex relationship between the anthropometric variation and eye response. The results of the study showed that the eye is more protected from impact with smaller orbital apertures, more brow protrusion, and less eye protrusion, provided that the orbital aperture is large enough to deter contact of the eye with the orbit.

  14. A finite difference model for free surface gravity drainage

    Energy Technology Data Exchange (ETDEWEB)

    Couri, F.R.; Ramey, H.J. Jr.

    1993-09-01

    The unconfined gravity flow of liquid with a free surface into a well is a classical well test problem which has not been well understood by either hydrologists or petroleum engineers. Paradigms have led many authors to treat an incompressible flow as compressible flow to justify the delayed yield behavior of a time-drawdown test. A finite-difference model has been developed to simulate the free surface gravity flow of an unconfined single phase, infinitely large reservoir into a well. The model was verified with experimental results in sandbox models in the literature and with classical methods applied to observation wells in the Groundwater literature. The simulator response was also compared with analytical Theis (1935) and Ramey et al. (1989) approaches for wellbore pressure at late producing times. The seepage face in the sandface and the delayed yield behavior were reproduced by the model considering a small liquid compressibility and incompressible porous medium. The potential buildup (recovery) simulated by the model evidenced a different- phenomenon from the drawdown, contrary to statements found in the Groundwater literature. Graphs of buildup potential vs time, buildup seepage face length vs time, and free surface head and sand bottom head radial profiles evidenced that the liquid refills the desaturating cone as a flat moving surface. The late time pseudo radial behavior was only approached after exaggerated long times.

  15. Predicting future glacial lakes in Austria using different modelling approaches

    Science.gov (United States)

    Otto, Jan-Christoph; Helfricht, Kay; Prasicek, Günther; Buckel, Johannes; Keuschnig, Markus

    2017-04-01

    Glacier retreat is one of the most apparent consequences of temperature rise in the 20th and 21th centuries in the European Alps. In Austria, more than 240 new lakes have formed in glacier forefields since the Little Ice Age. A similar signal is reported from many mountain areas worldwide. Glacial lakes can constitute important environmental and socio-economic impacts on high mountain systems including water resource management, sediment delivery, natural hazards, energy production and tourism. Their development significantly modifies the landscape configuration and visual appearance of high mountain areas. Knowledge on the location, number and extent of these future lakes can be used to assess potential impacts on high mountain geo-ecosystems and upland-lowland interactions. Information on new lakes is critical to appraise emerging threads and potentials for society. The recent development of regional ice thickness models and their combination with high resolution glacier surface data allows predicting the topography below current glaciers by subtracting ice thickness from glacier surface. Analyzing these modelled glacier bed surfaces reveals overdeepenings that represent potential locations for future lakes. In order to predict the location of future glacial lakes below recent glaciers in the Austrian Alps we apply different ice thickness models using high resolution terrain data and glacier outlines. The results are compared and validated with ice thickness data from geophysical surveys. Additionally, we run the models on three different glacier extents provided by the Austrian Glacier Inventories from 1969, 1998 and 2006. Results of this historical glacier extent modelling are compared to existing glacier lakes and discussed focusing on geomorphological impacts on lake evolution. We discuss model performance and observed differences in the results in order to assess the approach for a realistic prediction of future lake locations. The presentation delivers

  16. Great Lakes Bathymetry

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lakes Michigan, Erie, Saint Clair, Ontario and Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and...

  17. Great Indoors Awards 2007

    Index Scriptorium Estoniae

    2007-01-01

    Hollandis Maastrichtis jagati 17. XI esimest korda rahvusvahelist auhinda The Great Indoors Award. Aasta sisekujundusfirmaks valiti Masamichi Katayama asutatud Wonderwall. Auhinna said veel Zaha Hadid, Heatherwick Studio, Ryui Nakamura Architects ja Item Idem

  18. Regional differences in prediction models of lung function in Germany

    Directory of Open Access Journals (Sweden)

    Schäper Christoph

    2010-04-01

    Full Text Available Abstract Background Little is known about the influencing potential of specific characteristics on lung function in different populations. The aim of this analysis was to determine whether lung function determinants differ between subpopulations within Germany and whether prediction equations developed for one subpopulation are also adequate for another subpopulation. Methods Within three studies (KORA C, SHIP-I, ECRHS-I in different areas of Germany 4059 adults performed lung function tests. The available data consisted of forced expiratory volume in one second, forced vital capacity and peak expiratory flow rate. For each study multivariate regression models were developed to predict lung function and Bland-Altman plots were established to evaluate the agreement between predicted and measured values. Results The final regression equations for FEV1 and FVC showed adjusted r-square values between 0.65 and 0.75, and for PEF they were between 0.46 and 0.61. In all studies gender, age, height and pack-years were significant determinants, each with a similar effect size. Regarding other predictors there were some, although not statistically significant, differences between the studies. Bland-Altman plots indicated that the regression models for each individual study adequately predict medium (i.e. normal but not extremely high or low lung function values in the whole study population. Conclusions Simple models with gender, age and height explain a substantial part of lung function variance whereas further determinants add less than 5% to the total explained r-squared, at least for FEV1 and FVC. Thus, for different adult subpopulations of Germany one simple model for each lung function measures is still sufficient.

  19. Describing different brain computer interface systems through a unique model: a UML implementation.

    Science.gov (United States)

    Quitadamo, Lucia Rita; Marciani, Maria Grazia; Cardarilli, Gian Carlo; Bianchi, Luigi

    2008-01-01

    All the protocols currently implemented in brain computer interface (BCI) experiments are characterized by different structural and temporal entities. Moreover, due to the lack of a unique descriptive model for BCI systems, there is not a standard way to define the structure and the timing of a BCI experimental session among different research groups and there is also great discordance on the meaning of the most common terms dealing with BCI, such as trial, run and session. The aim of this paper is to provide a unified modeling language (UML) implementation of BCI systems through a unique dynamic model which is able to describe the main protocols defined in the literature (P300, mu-rhythms, SCP, SSVEP, fMRI) and demonstrates to be reasonable and adjustable according to different requirements. This model includes a set of definitions of the typical entities encountered in a BCI, diagrams which explain the structural correlations among them and a detailed description of the timing of a trial. This last represents an innovation with respect to the models already proposed in the literature. The UML documentation and the possibility of adapting this model to the different BCI systems built to date, make it a basis for the implementation of new systems and a mean for the unification and dissemination of resources. The model with all the diagrams and definitions reported in the paper are the core of the body language framework, a free set of routines and tools for the implementation, optimization and delivery of cross-platform BCI systems.

  20. Modeling regionalized volumetric differences in protein-ligand binding cavities.

    Science.gov (United States)

    Chen, Brian Y; Bandyopadhyay, Soutir

    2012-06-21

    Identifying elements of protein structures that create differences in protein-ligand binding specificity is an essential method for explaining the molecular mechanisms underlying preferential binding. In some cases, influential mechanisms can be visually identified by experts in structural biology, but subtler mechanisms, whose significance may only be apparent from the analysis of many structures, are harder to find. To assist this process, we present a geometric algorithm and two statistical models for identifying significant structural differences in protein-ligand binding cavities. We demonstrate these methods in an analysis of sequentially nonredundant structural representatives of the canonical serine proteases and the enolase superfamily. Here, we observed that statistically significant structural variations identified experimentally established determinants of specificity. We also observed that an analysis of individual regions inside cavities can reveal areas where small differences in shape can correspond to differences in specificity.

  1. Artificial Neural Network L* from different magnetospheric field models

    Science.gov (United States)

    Yu, Y.; Koller, J.; Zaharia, S. G.; Jordanova, V. K.

    2011-12-01

    The third adiabatic invariant L* plays an important role in modeling and understanding the radiation belt dynamics. The popular way to numerically obtain the L* value follows the recipe described by Roederer [1970], which is, however, slow and computational expensive. This work focuses on a new technique, which can compute the L* value in microseconds without losing much accuracy: artificial neural networks. Since L* is related to the magnetic flux enclosed by a particle drift shell, global magnetic field information needed to trace the drift shell is required. A series of currently popular empirical magnetic field models are applied to create the L* data pool using 1 million data samples which are randomly selected within a solar cycle and within the global magnetosphere. The networks, trained from the above L* data pool, can thereby be used for fairly efficient L* calculation given input parameters valid within the trained temporal and spatial range. Besides the empirical magnetospheric models, a physics-based self-consistent inner magnetosphere model (RAM-SCB) developed at LANL is also utilized to calculate L* values and then to train the L* neural network. This model better predicts the magnetospheric configuration and therefore can significantly improve the L*. The above neural network L* technique will enable, for the first time, comprehensive solar-cycle long studies of radiation belt processes. However, neural networks trained from different magnetic field models can result in different L* values, which could cause mis-interpretation of radiation belt dynamics, such as where the source of the radiation belt charged particle is and which mechanism is dominant in accelerating the particles. Such a fact calls for attention to cautiously choose a magnetospheric field model for the L* calculation.

  2. Towards methodical modelling: Differences between the structure and output dynamics of multiple conceptual models

    Science.gov (United States)

    Knoben, Wouter; Woods, Ross; Freer, Jim

    2016-04-01

    Conceptual hydrologic models consist of a certain arrangement of spatial and temporal dynamics consisting of stores, fluxes and transformation functions, depending on the modeller's choices and intended use. They have the advantages of being computationally efficient, being relatively easy model structures to reconfigure and having relatively low input data demands. This makes them well-suited for large-scale and large-sample hydrology, where appropriately representing the dominant hydrologic functions of a catchment is a main concern. Given these requirements, the number of parameters in the model cannot be too high, to avoid equifinality and identifiability issues. This limits the number and level of complexity of dominant hydrologic processes the model can represent. Specific purposes and places thus require a specific model and this has led to an abundance of conceptual hydrologic models. No structured overview of these models exists and there is no clear method to select appropriate model structures for different catchments. This study is a first step towards creating an overview of the elements that make up conceptual models, which may later assist a modeller in finding an appropriate model structure for a given catchment. To this end, this study brings together over 30 past and present conceptual models. The reviewed model structures are simply different configurations of three basic model elements (stores, fluxes and transformation functions), depending on the hydrologic processes the models are intended to represent. Differences also exist in the inner workings of the stores, fluxes and transformations, i.e. the mathematical formulations that describe each model element's intended behaviour. We investigate the hypothesis that different model structures can produce similar behavioural simulations. This can clarify the overview of model elements by grouping elements which are similar, which can improve model structure selection.

  3. TEC Longitude Difference Using GIMS and the IRI Model

    Science.gov (United States)

    Natali, Maria Paula; Meza, Amalia Margarita; Mendoza, Gastón

    2016-07-01

    The main geomagnetic field declination has a global distribution with positive and negative values showing maximum east-west differences over North America and Oceania and minimum differences over America and Asia. Several authors study one or more of these regions using TEC data derived from GNSS observations to describe variations in TEC. They reported a pronounced longitudinal variation respect to zero magnetic declination. One of the important factors that cause the longitude difference at mid-latitude is a combined effect of the longitude variations of magnetic declination and the variations of the zonal thermospheric winds with local time. We propose to study this effect using Global Ionospheric Maps (GIMs) and the respective TEC values generated from the International Reference Ionospheric (IRI) model, during a solar cycle, applying Principal Component Analysis (PCA). Our works is focused over different local times and regions at mid-latitude. PCA involves a mathematical procedure that transforms a number of correlated variables into a number of uncorrelated variables using the data itself. The spatial structure of the ionosphere variability and its temporal evolution, together are called modes, and there are ordered according to their percentage of the variability of data from highest to lowest. In this analysis the first mode has more than the 90 % of the variability, representing the nominal behavior of the ionosphere, and the second and third modes are the more important for our analysis, because they show the strong longitudinal variation in the different regions using either GIMs or the IRI model.

  4. Convergence of a finite difference method for combustion model problems

    Institute of Scientific and Technical Information of China (English)

    YING; Long'an

    2004-01-01

    We study a finite difference scheme for a combustion model problem. A projection scheme near the combustion wave, and the standard upwind finite difference scheme away from the combustion wave are applied. Convergence to weak solutions with a combustion wave is proved under the normal Courant-Friedrichs-Lewy condition. Some conditions on the ignition temperature are given to guarantee the solution containing a strong detonation wave or a weak detonation wave. Convergence to strong detonation wave solutions for the random projection method is also proved.

  5. Baroclinic pressure gradient difference schemes of subtracting the local averaged density stratification in sigma coordinates models

    Institute of Scientific and Technical Information of China (English)

    ZHU Shouxian; ZHANG Wenjing

    2008-01-01

    Much has been written of the error in computing the baroclinic pressure gradient (BPG) with sigma coordinates in ocean or atmos- pheric numerical models. The usual way to reduce the error is to subtract area-averaged density stratification of the whole computa- tion region. But if there is great difference between the area-averaged and the local averaged density stratification, the error will be obvious. An example is given to show that the error from this method may be larger than that from no correction sometimes. The definition of local area is put forward. Then, four improved BPG difference schemes of subtracting the local averaged density strat- ification are designed to reduce the error. Two of them are for diagnostic calculation (density field is fixed), and the others are for prognostic calculation (density field is not fixed). The results show that the errors from these schemes all significantly decrease.

  6. Survey of trust models in different network domains

    CERN Document Server

    Momani, Mohammad

    2010-01-01

    This paper introduces the security and trust concepts in wireless sensor networks and explains the difference between them, stating that even though both terms are used interchangeably when defining a secure system, they are not the same. The difference between reputation and trust is also explained, highlighting that reputation partially affects trust. A survey of trust and reputation systems in various domains is conducted, with more details given to models in ad-hoc and sensor networks as they are closely related to each other and to our research interests. The methodologies used to model trust and their references are presented. The factors affecting trust updating are summarised and some examples of the systems in which these factors have been implemented are given. The survey states that, even though researchers have started to explore the issue of trust in wireless sensor networks, they are still examining the trust associated with routing messages between nodes (binary events). However, wireless senso...

  7. Modeling satisfaction amongst the elderly in different Chinese urban neighborhoods.

    Science.gov (United States)

    Yan, Bingqiu; Gao, Xiaolu; Lyon, Michael

    2014-10-01

    Rapidly aging populations constitute a critical issue for researchers and policymakers across the world; the challenges of a shifting demographic structure are particularly pertinent in the case of China. Population control strategies implemented in China in the late 1970s have substantially changed the social and demographic structure of Chinese cities and the traditional role of families in caring for elderly people. To meet the growing needs of elderly residents "aging in place," age-friendly environments and new types of senior services are required and encouraged. This research examines the satisfaction of seniors in relation to the elderly services and living environments available to them, through empirical studies of six types of neighborhoods in Beijing. Using structural equation modeling (SEM), a satisfaction model under the Person-Environment Fit (P-E Fit) model framework was developed. This model considered the senior respondent's health status, economic attributes, family and social support networks, and neighborhood living environments. Social support was found to be the primary factor affecting satisfaction amongst the urban elderly in Beijing. The research also highlights the need to differentiate between different types of neighborhoods, which can differ significantly in terms of the socio-economic attributes (i.e., family structure, income, and education) of their senior residents. As such, based on the path coefficients revealed by different structural equation models of various neighborhoods, four types of neighborhoods were identified: in Type 1 neighborhoods, the neighborhood environment and the senior services provided by communities were primary factors in elderly satisfaction; in Type 2 neighborhoods, the satisfaction of inhabitants was strongly influenced by personal attributes such as health and income; Type 3 neighborhoods were residence of low-income people where the level of social support was the foremost factor; and in Type 4, social

  8. Viscoelastic Finite Difference Modeling Using Graphics Processing Units

    Science.gov (United States)

    Fabien-Ouellet, G.; Gloaguen, E.; Giroux, B.

    2014-12-01

    Full waveform seismic modeling requires a huge amount of computing power that still challenges today's technology. This limits the applicability of powerful processing approaches in seismic exploration like full-waveform inversion. This paper explores the use of Graphics Processing Units (GPU) to compute a time based finite-difference solution to the viscoelastic wave equation. The aim is to investigate whether the adoption of the GPU technology is susceptible to reduce significantly the computing time of simulations. The code presented herein is based on the freely accessible software of Bohlen (2002) in 2D provided under a General Public License (GNU) licence. This implementation is based on a second order centred differences scheme to approximate time differences and staggered grid schemes with centred difference of order 2, 4, 6, 8, and 12 for spatial derivatives. The code is fully parallel and is written using the Message Passing Interface (MPI), and it thus supports simulations of vast seismic models on a cluster of CPUs. To port the code from Bohlen (2002) on GPUs, the OpenCl framework was chosen for its ability to work on both CPUs and GPUs and its adoption by most of GPU manufacturers. In our implementation, OpenCL works in conjunction with MPI, which allows computations on a cluster of GPU for large-scale model simulations. We tested our code for model sizes between 1002 and 60002 elements. Comparison shows a decrease in computation time of more than two orders of magnitude between the GPU implementation run on a AMD Radeon HD 7950 and the CPU implementation run on a 2.26 GHz Intel Xeon Quad-Core. The speed-up varies depending on the order of the finite difference approximation and generally increases for higher orders. Increasing speed-ups are also obtained for increasing model size, which can be explained by kernel overheads and delays introduced by memory transfers to and from the GPU through the PCI-E bus. Those tests indicate that the GPU memory size

  9. A reasonable model or a liberal failure? The economic model in Latin America from the 1990s to the great crisis

    Directory of Open Access Journals (Sweden)

    Diego Sánchez Ancochea

    2009-05-01

    Full Text Available This paper critically evaluates the results in terms of economic growth and structural transformation of the new economic model implemented by most Latin American countries since the early 1990s. The new model, which had macroeconomic stability and export orientation as its core components, has been unable to develop more dynamic comparative advantages in the current global era and, as a result, has resulted in lower rates of economic growth than in Asia. The paper closes with an analysis of the impact of the current financial crisis in the region. It highlights the short-term costs, but also acknowledges the opportunities that the crisis is creating to promote a greater number of new progressive development alternatives that place more emphasis on the role of learning and innovation.

  10. Creation of Warehouse Models for Different Layout Designs

    OpenAIRE

    Köhler, Mirko; Lukić, Ivica; Nenadić, Krešimir

    2014-01-01

    Warehouse is one of the most important components in logistics of the supply chain network. Efficiency of warehouse operations is influenced by many different factors. One of the key factors is the racks layout configuration. A warehouse with good racks layout may significantly reduce the cost of warehouse servicing. The objective of this paper is to give a scheme for building warehouses models with one-block and two-block layout for future research in warehouse optimization. An algorithm ...

  11. Accurate Spectral Fits of Jupiter's Great Red Spot: VIMS Visual Spectra Modelled with Chromophores Created by Photolyzed Ammonia Reacting with Acetyleneχ±

    Science.gov (United States)

    Baines, Kevin; Sromovsky, Lawrence A.; Fry, Patrick M.; Carlson, Robert W.; Momary, Thomas W.

    2016-10-01

    We report results incorporating the red-tinted photochemically-generated aerosols of Carlson et al (2016, Icarus 274, 106-115) in spectral models of Jupiter's Great Red Spot (GRS). Spectral models of the 0.35-1.0-micron spectrum show good agreement with Cassini/VIMS near-center-meridian and near-limb GRS spectra for model morphologies incorporating an optically-thin layer of Carlson (2016) aerosols at high altitudes, either at the top of the tropospheric GRS cloud, or in a distinct stratospheric haze layer. Specifically, a two-layer "crème brûlée" structure of the Mie-scattering Carlson et al (2016) chromophore attached to the top of a conservatively scattering (hereafter, "white") optically-thick cloud fits the spectra well. Currently, best agreement (reduced χ2 of 0.89 for the central-meridian spectrum) is found for a 0.195-0.217-bar, 0.19 ± 0.02 opacity layer of chromophores with mean particle radius of 0.14 ± 0.01 micron. As well, a structure with a detached stratospheric chromophore layer ~0.25 bar above a white tropospheric GRS cloud provides a good spectral match (reduced χ2 of 1.16). Alternatively, a cloud morphology with the chromophore coating white particles in a single optically- and physically-thick cloud (the "coated-shell model", initially explored by Carlson et al 2016) was found to give significantly inferior fits (best reduced χ2 of 2.9). Overall, we find that models accurately fit the GRS spectrum if (1) most of the optical depth of the chromophore is in a layer near the top of the main cloud or in a distinct separated layer above it, but is not uniformly distributed within the main cloud, (2) the chromophore consists of relatively small, 0.1-0.2-micron-radius particles, and (3) the chromophore layer optical depth is small, ~ 0.1-0.2. Thus, our analysis supports the exogenic origin of the red chromophore consistent with the Carlson et al (2016) photolytic production mechanism rather than an endogenic origin, such as upwelling of material

  12. Great ape foresight is looking great.

    Science.gov (United States)

    Osvath, Mathias

    2010-09-01

    Suddendorf, Corballis and Collier-Baker (Anim Cogn 12: 751-754, 2009) comment on a study on great ape foresight (Osvath and Osvath, Anim Cogn 11: 661-674, 2008). That study consisted of four experiments investigating foresight in chimpanzees and orangutans, examining in particular whether the planning they exhibit is best explained by assuming an episodic cognitive system. This system has widely been regarded as exclusive to humans. Indeed, the Bischof-Köhler hypothesis explicitly states that planning for a future need is outside the abilities of non-humans. In our paper, we argued that the results implied the presence of episodic abilities and challenged the Bischof-Köhler hypothesis. Suddendorf et al. are not ready to accept this claim. They critique each experiment in detail and maintain their view that episodic cognition is unique to humans. Here, I point out the misapprehensions and weaknesses in their critique notably a lack of appreciation for how the experiments in the study are interrelated and serve as controls for each other and for the baseline experiment. I reinforce my earlier conclusions with a number of recently published findings.

  13. Comparison of different efficiency criteria for hydrological model assessment

    Directory of Open Access Journals (Sweden)

    P. Krause

    2005-01-01

    Full Text Available The evaluation of hydrologic model behaviour and performance is commonly made and reported through comparisons of simulated and observed variables. Frequently, comparisons are made between simulated and measured streamflow at the catchment outlet. In distributed hydrological modelling approaches, additional comparisons of simulated and observed measurements for multi-response validation may be integrated into the evaluation procedure to assess overall modelling performance. In both approaches, single and multi-response, efficiency criteria are commonly used by hydrologists to provide an objective assessment of the "closeness" of the simulated behaviour to the observed measurements. While there are a few efficiency criteria such as the Nash-Sutcliffe efficiency, coefficient of determination, and index of agreement that are frequently used in hydrologic modeling studies and reported in the literature, there are a large number of other efficiency criteria to choose from. The selection and use of specific efficiency criteria and the interpretation of the results can be a challenge for even the most experienced hydrologist since each criterion may place different emphasis on different types of simulated and observed behaviours. In this paper, the utility of several efficiency criteria is investigated in three examples using a simple observed streamflow hydrograph.

  14. Modelling of UV radiation variations at different time scales

    Directory of Open Access Journals (Sweden)

    J. L. Borkowski

    2008-03-01

    Full Text Available Solar UV radiation variability in the period 1976–2006 is discussed with respect to the relative changes in the solar global radiation, ozone content, and cloudiness. All the variables were decomposed into separate components, representing variations of different time scales, using wavelet multi-resolution decomposition. The response of the UV radiation to the changes in the solar global radiation, ozone content, and cloudiness depends on the time scale, therefore, it seems reasonable to model separately the relation between UV and explanatory variables at different time scales. The wavelet components of the UV series are modelled and summed to obtain the fit of observed series. The results show that the coarser time scale components can be modelled with greater accuracy than fine scale components and the fitted values calculated by this method are in better agreement with observed values than values calculated by the regression method, in which variables were not decomposed. The residual standard error in the case of modelling with the use of wavelets is reduced by 14% in comparison to the regression method without decomposition.

  15. The Eemian climate simulated by two models of different complexities

    Science.gov (United States)

    Nikolova, Irina; Yin, Qiuzhen; Berger, Andre; Singh, Umesh; Karami, Pasha

    2013-04-01

    The Eemian period, also known as MIS-5, experienced warmer than today climate, reduction in ice sheets and important sea-level rise. These interesting features have made the Eemian appropriate to evaluate climate models when forced with astronomical and greenhouse gas forcings different from today. In this work, we present the simulated Eemian climate by two climate models of different complexities, LOVECLIM (LLN Earth system model of intermediate complexity) and CCSM3 (NCAR atmosphere-ocean general circulation model). Feedbacks from sea ice, vegetation, monsoon and ENSO phenomena are discussed to explain the regional similarities/dissimilarities in both models with respect to the pre-industrial (PI) climate. Significant warming (cooling) over almost all the continents during boreal summer (winter) leads to a largely increased (reduced) seasonal contrast in the northern (southern) hemisphere, mainly due to the much higher (lower) insolation received by the whole Earth in boreal summer (winter). The arctic is warmer than at PI through the whole year, resulting from its much higher summer insolation and its remnant effect in the following fall-winter through the interactions between atmosphere, ocean and sea ice. Regional discrepancies exist in the sea-ice formation zones between the two models. Excessive sea-ice formation in CCSM3 results in intense regional cooling. In both models intensified African monsoon and vegetation feedback are responsible for the cooling during summer in North Africa and on the Arabian Peninsula. Over India precipitation maximum is found further west, while in Africa the precipitation maximum migrates further north. Trees and grassland expand north in Sahel/Sahara, trees being more abundant in the results from LOVECLIM than from CCSM3. A mix of forest and grassland occupies continents and expand deep in the high northern latitudes in line with proxy records. Desert areas reduce significantly in Northern Hemisphere, but increase in North

  16. Matter Effects on Neutrino Oscillations in Different Supernova Models

    Science.gov (United States)

    Xu, Jing; Hu, Li-Jun; Li, Rui-Cheng; Guo, Xin-Heng; Young, Bing-Lin

    2016-04-01

    In recent years, with the development of simulations about supernova explosion, we have a better understanding about the density profiles and the shock waves in supernovae than before. There might be a reverse shock wave, another sudden change of density except the forward shock wave, or even no shock wave, emerging in the supernova. Instead of using the expression of the crossing probability at the high resonance, PH, we have studied the matter effects on neutrino oscillations in different supernova models. In detail, we have calculated the survival probability of ve (Ps) and the conversion probability of vx (Pc) in the Schrödinger equation within a simplified two-flavor framework for a certain case, in which the neutrino transfers through the supernova matter from an initial flavor eigenstate located at the core of the supernova. Our calculations was based on the data of density in three different supernova models obtained from simulations. In our work, we do not steepen the density gradient around the border of the shock wave, which differs to what was done in most of the other simulations. It is found that the mass and the density distribution of the supernova do make a difference on the behavior of Ps and Pc. With the results of Ps and Pc, we can estimate the number of ve (and vx) remained in the beam after they go through the matter in the supernova. Supported by National Science Foundation of China under Grant Nos. 11175020 and 11275025

  17. 3D Finite Difference Modelling of Basaltic Region

    Science.gov (United States)

    Engell-Sørensen, L.

    2003-04-01

    The main purpose of the work was to generate realistic data to be applied for testing of processing and migration tools for basaltic regions. The project is based on the three - dimensional finite difference code (FD), TIGER, made by Sintef. The FD code was optimized (parallelized) by the author, to run on parallel computers. The parallel code enables us to model large-scale realistic geological models and to apply traditional seismic and micro seismic sources. The parallel code uses multiple processors in order to manipulate subsets of large amounts of data simultaneously. The general anisotropic code uses 21 elastic coefficients. Eight independent coefficients are needed as input parameters for the general TI medium. In the FD code, the elastic wave field computation is implemented by a higher order FD solution to the elastic wave equation and the wave fields are computed on a staggered grid, shifted half a node in one or two directions. The geological model is a gridded basalt model, which covers from 24 km to 37 km of a real shot line in horizontal direction and from the water surface to the depth of 3.5 km. The 2frac {1}{2}D model has been constructed using the compound modeling software from Norsk Hydro. The vertical parameter distribution is obtained from observations in two wells. At The depth of between 1100 m to 1500 m, a basalt horizon covers the whole sub surface layers. We have shown that it is possible to simulate a line survey in realistic (3D) geological models in reasonable time by using high performance computers. The author would like to thank Norsk Hydro, Statoil, GEUS, and SINTEF for very helpful discussions and Parallab for being helpful with the new IBM, p690 Regatta system.

  18. 笼养大鸨繁殖不同时期行为时间分配及活动节律%Time Budget of Behaviors and Activity Rhytinn of Great Bustard in Captivity During Different Breeding Periods

    Institute of Scientific and Technical Information of China (English)

    卢小琴; 田秀华

    2011-01-01

    The instantaneous scan method was used to study the time budget of breeding behaviors and activity rhythm of Great Bustards in Changchun Zoological and Botanical Gardens during April-August in 2010. The differences in time budget of behaviors of Great Bustards in the same breeding period between male and female and of the same sex between different breeding periods were analyzed by independent sample T-test. Results show that the time budget of behaviors and activity rhythm of the Great bustards are regular to some degree. Feeding mostly occurs in the middle of the morning and the afternoon, flaunting and hatching mostly in the morning and evening, and resting mostly occurs at noon. During the prophase of breeding, the Great bustards spend their time mainly in standing, lying and walking, and the male and the female spend 80.63% and 66.34% of their time on the three behaviors, respectively. The time budget of the male changes greatly during the anaphase of breeding. They spend 90.41% of their time in incubating in the nest, and incubating, feeding and alerting behaviors have an obvious rhythm; however, the male still spend 59.23% of their time mainly in standing, lying and walking. The time budget of behaviors of Great Bustards exhibits differences not only between the male and the female, but also between the prophase and anaphase of breeding.%2010年4月到8月,采用瞬时扫描法对长春动植物公园两对繁殖良好的大鸨的繁殖行为时间分配和活动节律进行了研究,并利用独立样本T检验分析了不同性别大鸨繁殖前后期行为的性别差异,以及相同性别的大鸨在繁殖的不同时期的行为差异.结果表示:大鸨繁殖期的各种行为活动具有一定的时间分配和日节律,取食行为多发生在上午和下午的中间时段,炫耀、孵化多在早晨和傍晚,而中午的大部分时间处于休息状态.繁殖前期,大鸨的行为主要表现为静立、趴卧和游走,雌雄大鸨的这3

  19. Evaluation of the Operational Multi-scale Environment model with Grid Adaptivity (OMEGA) for use in Wind Energy Applications in the Great Basin of Nevada

    Science.gov (United States)

    King, Kristien C.

    characterizing areas of complex terrain. Model sensitivity to horizontal grid resolution, initial conditions, and time of initialization were tested. OMEGA was run over three different horizontal grid resolutions with minimum horizontal edge lengths of: 18 km, 6 km, and 2 km. For each resolution, the model was initialized using both the Global Forecasting System (GFS) and North American Regional Reanalysis (NARR) to determine model sensitivity to initial conditions. For both the NARR and GFS initializations, the model was started at both 0000 UTC and 1200 UTC to determine the effect of start time and stability regime on the performance of the model. An additional intensive study into the model's performance was also conducted by a detailed evaluation of model results during two separate 24-hour periods, the first a period where the model performed well and the second a period where the model performed poorly, to determine which atmospheric factors most affect the predictive ability of the OMEGA model. The statistical results were then compared with the results from the MM5 and WRF simulations to determine the most appropriate model for wind energy potential studies in complex terrain.

  20. Hadron Resonance Gas Model for An Arbitrarily Large Number of Different Hard-Core Radii

    CERN Document Server

    Oliinychenko, D R; Sagun, V V; Ivanytskyi, A I; Yakimenko, I P; Nikonov, E G; Taranenko, A V; Zinovjev, G M

    2016-01-01

    We develop a novel formulation of the hadron-resonance gas model which, besides a hard-core repulsion, explicitly accounts for the surface tension induced by the interaction between the particles. Such an equation of state allows us to go beyond the Van der Waals approximation for any number of different hard-core radii. A comparison with the Carnahan-Starling equation of state shows that the new model is valid for packing fractions 0.2-0.22, while the usual Van der Waals model is inapplicable at packing fractions above 0.11-0.12. Moreover, it is shown that the equation of state with induced surface tension is softer than the one of hard spheres and remains causal at higher particle densities. The great advantage of our model is that there are only two equations to be solved and it does not depend on the various values of the hard-core radii used for different hadronic resonances. Using this novel equation of state we obtain a high-quality fit of the ALICE hadron multiplicities measured at center-of-mass ener...

  1. Model Based Analysis of Ethnic Differences in Type 2 Diabetes

    DEFF Research Database (Denmark)

    Møller, Jonas Bech

    The present thesis deals with different aspects of population pharmacokinetic /pharmacodynamic (PK/PD) modelling of the glucose homeostatic system. The thesis consist of a summary report and four scientific research papers. A description of the main topics covered in the thesis is given in the su......The present thesis deals with different aspects of population pharmacokinetic /pharmacodynamic (PK/PD) modelling of the glucose homeostatic system. The thesis consist of a summary report and four scientific research papers. A description of the main topics covered in the thesis is given...... of the glucose homeostatic system, which is a complex feedback system mainly involving mainly organs such as the liver and the pancreas, the hormones insulin and glucagon, and the carbohydrate glucose. As for any other dynamical system, a proper characterisation at non-steady state, requires a proper input...... to the system. This input must reflect the circumstances in which one wants to draw conclusions. In this thesis the intake of oral glucose, which closely resembles the intake of food under daily living has been applied. Mathematical modelling of such complex physiologal phenomenas as the glucosehomeostatic...

  2. Analysis of Urine Flow in Three Different Ureter Models

    Directory of Open Access Journals (Sweden)

    Kyung-Wuk Kim

    2017-01-01

    Full Text Available The ureter provides a way for urine to flow from the kidney to the bladder. Peristalsis in the ureter partially forces the urine flow, along with hydrostatic pressure. Ureteral diseases and a double J stent, which is commonly inserted in a ureteral stenosis or occlusion, disturb normal peristalsis. Ineffective or no peristalsis could make the contour of the ureter a tube, a funnel, or a combination of the two. In this study, we investigated urine flow in the abnormal situation. We made three different, curved tubular, funnel-shaped, and undulated ureter models that were based on human anatomy. A numerical analysis of the urine flow rate and pattern in the ureter was performed for a combination of the three different ureters, with and without a ureteral stenosis and with four different types of double J stents. The three ureters showed a difference in urine flow rate and pattern. Luminal flow rate was affected by ureter shape. The side holes of a double J stent played a different role in detour, which depended on ureter geometry.

  3. Selected Basin Characterization Model Parameters for the Great Basin Carbonate and Alluvial Aquifer System of Nevada, Utah, and Parts of Adjacent States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a study focusing on ground-water resources in the Great Basin carbonate and alluvial aquifer system (GBCAAS). The GBCAAS is a...

  4. Coalescence of Liquid Drops: Different Models Versus Experiment

    CERN Document Server

    Sprittles, James

    2012-01-01

    The process of coalescence of two identical liquid drops is simulated numerically in the framework of two essentially different mathematical models, and the results are compared with experimental data on the very early stages of the coalescence process reported recently. The first model tested is the `conventional' one, where it is assumed that coalescence as the formation of a single body of fluid occurs by an instant appearance of a liquid bridge smoothly connecting the two drops, and the subsequent process is the evolution of this single body of fluid driven by capillary forces. The second model under investigation considers coalescence as a process where a section of the free surface becomes trapped between the bulk phases as the drops are pressed against each other, and it is the gradual disappearance of this `internal interface' that leads to the formation of a single body of fluid and the conventional model taking over. Using the full numerical solution of the problem in the framework of each of the tw...

  5. SMT-based Bounded Model Checking with Difference Logic Constraints

    CERN Document Server

    Bersani, Marcello M; Morzenti, Angelo; Pradella, Matteo; Rossi, Matteo; Pietro, Pierluigi San

    2010-01-01

    Traditional Bounded Model Checking (BMC) is based on translating the model checking problem into SAT, the Boolean satisfiability problem. This paper introduces an encoding of Linear Temporal Logic with Past operators (PLTL) into the Quantifier-Free Difference Logic with Uninterpreted Functions (QF-UFIDL). The resulting encoding is a simpler and more concise version of existing SATbased encodings, currently used in BMC. In addition, we present an extension of PLTL augmented with arithmetic relations over integers, which can express unbounded counters; as such, the extended logic is more expressive than PLTL. We introduce suitable restrictions and assumptions that are shown to make the verification problem for the extended logic decidable, and we define an encoding of the new logic into QF-UFIDL. Finally, a performance comparison with the SAT-based approach on purely PLTL examples shows significant improvements in terms of both execution time and memory occupation.

  6. Meta-model of EPortfolio Usage in Different Environments

    Directory of Open Access Journals (Sweden)

    Igor Balaban

    2011-09-01

    Full Text Available EPortfolio offers a new philosophy of teaching and learning, giving the learner an opportunity to express oneself, to show one’s past work and experience to all the interested parties ranging from teachers to potential employers. However, an integral model for ePortfolio implementation in academic institutions that would take into account three different levels of stakeholders: 1. Individual (student and teacher; 2. Institution; and 3. Employer, currently does not exist. In this paper the role of ePortfolio in academic environment as well as the context in which ePortfolio operates is analyzed in detail. As a result of the comprehensive analysis that takes into account individual, academic institution and employer, a meta-model of ePortfolio usage in Lifelong Learning is proposed.

  7. Using suggestion to model different types of automatic writing.

    Science.gov (United States)

    Walsh, E; Mehta, M A; Oakley, D A; Guilmette, D N; Gabay, A; Halligan, P W; Deeley, Q

    2014-05-01

    Our sense of self includes awareness of our thoughts and movements, and our control over them. This feeling can be altered or lost in neuropsychiatric disorders as well as in phenomena such as "automatic writing" whereby writing is attributed to an external source. Here, we employed suggestion in highly hypnotically suggestible participants to model various experiences of automatic writing during a sentence completion task. Results showed that the induction of hypnosis, without additional suggestion, was associated with a small but significant reduction of control, ownership, and awareness for writing. Targeted suggestions produced a double dissociation between thought and movement components of writing, for both feelings of control and ownership, and additionally, reduced awareness of writing. Overall, suggestion produced selective alterations in the control, ownership, and awareness of thought and motor components of writing, thus enabling key aspects of automatic writing, observed across different clinical and cultural settings, to be modelled.

  8. Performance of enlarged blood pump models with five different impellers.

    Science.gov (United States)

    Chua, L P; Yu, S C; Leo, H L

    2000-01-01

    In earlier studies, a 5:1 enlarged pump model of the Kyoto-NTN Magnetically Suspended Centrifugal Blood Pump had been constructed and the flow characteristics investigated. Although the results obtained were satisfactory, the medium used was air. A 5:1 enlarged pump model using water as the medium thus was designed and constructed. Five different impeller blade profile designs were used in the present study. By varying (1) the blade profile design: forward, radial, and backward, (2) the number of blades used, and (3) the rotating speed, the flow characteristics of the pump were investigated. It was found that the impeller with the higher number of blades, used in the forward and straight blade profiles, have the best performance.

  9. Effects of different scale land cover maps in watershed modelling

    Science.gov (United States)

    Nunes, Antonio; Araújo, Antonio; Alexandridis, Thomas; Chambel, Pedro

    2013-04-01

    Water management is a rather complex process that usually involves multiple stakeholder, multiple data and sources, and complex mathematical modelling. One of the key data sets to understand a particular water system is the characterization of the land cover. Land cover maps are essential for the estimation of environmental variables (e.g. LAI, ETa) related to water quantity. Also, land cover maps are used for modelling the water quality. For instance, watersheds that have intensive agriculture can have poor water quality due to increase of nutrients loading; forest fires have a significant negative impact over the water quality by increasing the sediment loads; forest fires can increase flood risks. The land cover dynamics can as well severely affect the water quantity and quality in watersheds. In the MyWater project we are conducting a study to supply water quantity and quality information services for five study areas in five different countries (Brazil, Greece, Mozambique, Netherlands, and Portugal). In this project several land cover maps were produced both at regional and local scales, based on the exploitation of medium and high resolution satellite images (MERIS and SPOT 4). These maps were produced through semi-automatic supervised classification procedures, using an LCCS based nomenclature of 15 classes. Validation results pointed to global accuracy values greater than 80% for all maps. In this paper we focus on studying the effect of using different scale land cover maps in the watershed modelling and its impact in results. The work presented is part of the FP7-EU project "Merging hydrological models and Earth observation data for reliable information on water - MyWater".

  10. Differences between the 1993 and 1995 CABO Model Energy Codes

    Energy Technology Data Exchange (ETDEWEB)

    Conover, D.R.; Lucas, R.G.

    1995-10-01

    The Energy Policy Act of 1992 requires the US DOE to determine if changes to the Council of American Building Officials` (CABO) 1993 Model Energy Code (MEC) (CABO 1993), published in the 1995 edition of the MEC (CABO 1995), will improve energy efficiency in residential buildings. The DOE, the states, and others have expressed an interest in the differences between the 1993 and 1995 editions of the MEC. This report describes each change to the 1993 MEC, and its impact. Referenced publications are also listed along with discrepancies between code changes approved in the 1994 and 1995 code-change cycles and what actually appears in the 1995 MEC.

  11. Quantitative interpretation of Great Lakes remote sensing data

    Science.gov (United States)

    Shook, D. F.; Salzman, J.; Svehla, R. A.; Gedney, R. T.

    1980-01-01

    The paper discusses the quantitative interpretation of Great Lakes remote sensing water quality data. Remote sensing using color information must take into account (1) the existence of many different organic and inorganic species throughout the Great Lakes, (2) the occurrence of a mixture of species in most locations, and (3) spatial variations in types and concentration of species. The radiative transfer model provides a potential method for an orderly analysis of remote sensing data and a physical basis for developing quantitative algorithms. Predictions and field measurements of volume reflectances are presented which show the advantage of using a radiative transfer model. Spectral absorptance and backscattering coefficients for two inorganic sediments are reported.

  12. The Great Dismal Swamp

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This introduction to the natural history of the Great Dismal Swamp is presented at a time when 50,000 acres of the Swamp are being converted from private holdings to...

  13. The Great Lakes.

    Science.gov (United States)

    Seasons, 1987

    1987-01-01

    The Great Lakes are one of the world's greatest reserviors of fresh water, the foundation of Ontario's economic development, a primary force in ecological systems, and a base for pleasure and recreation. These lakes and their relationship with people of Canada and the United States can be useful as a subject for teaching the impact of human…

  14. Sources, fate, and pathways of Leeuwin Current water in the Indian Ocean and Great Australian Bight: A Lagrangian study in an eddy-resolving ocean model

    Science.gov (United States)

    Yit Sen Bull, Christopher; van Sebille, Erik

    2016-03-01

    The Leeuwin Current is the dominant circulation feature in the eastern Indian Ocean, transporting tropical and subtropical water southward. While it is known that the Leeuwin Current draws its water from a multitude of sources, existing Indian Ocean circulation schematics have never quantified the fluxes of tropical and subtropical source water flowing into the Leeuwin Current. This paper uses virtual Lagrangian particles to quantify the transport of these sources along the Leeuwin Current's mean pathway. Here the pathways and exchange of Leeuwin Current source waters across six coastally bound sectors on the south-west Australian coast are analyzed. This constitutes the first quantitative assessment of Leeuwin Current pathways within an offline, 50 year integration time, eddy-resolving global ocean model simulation. Along the Leeuwin Current's pathway, we find a mean poleward transport of 3.7 Sv in which the tropical sources account for 60-78% of the transport. While the net transport is small, we see large transports flowing in and out of all the offshore boundaries of the Leeuwin Current sectors. Along the Leeuwin Current's pathway, we find that water from the Indonesian Throughflow contributes 50-66% of the seasonal signal. By applying conditions on the routes particles take entering the Leeuwin Current, we find particles are more likely to travel offshore north of 30°S, while south of 30°S, particles are more likely to continue downstream. We find a 0.2 Sv pathway of water from the Leeuwin Current's source regions, flowing through the entire Leeuwin Current pathway into the Great Australian Bight.

  15. Modelling droplet collision outcomes for different substances and viscosities

    Science.gov (United States)

    Sommerfeld, Martin; Kuschel, Matthias

    2016-12-01

    The main objective of the present study is the derivation of models describing the outcome of binary droplet collisions for a wide range of dynamic viscosities in the well-known collision maps (i.e. normalised lateral droplet displacement at collision, called impact parameter, versus collision Weber number). Previous studies by Kuschel and Sommerfeld (Exp Fluids 54:1440, 2013) for different solution droplets having a range of solids contents and hence dynamic viscosities (here between 1 and 60 mPa s) revealed that the locations of the triple point (i.e. coincidence of bouncing, stretching separation and coalescence) and the critical Weber number (i.e. condition for the transition from coalescence to separation for head-on collisions) show a clear dependence on dynamic viscosity. In order to extend these findings also to pure liquids and to provide a broader data basis for modelling the viscosity effect, additional binary collision experiments were conducted for different alcohols (viscosity range 1.2-15.9 mPa s) and the FVA1 reference oil at different temperatures (viscosity range 3.0-28.2 mPa s). The droplet size for the series of alcohols was around 365 and 385 µm for the FVA1 reference oil, in each case with fixed diameter ratio at Δ= 1. The relative velocity between the droplets was varied in the range 0.5-3.5 m/s, yielding maximum Weber numbers of around 180. Individual binary droplet collisions with defined conditions were generated by two droplet chains each produced by vibrating orifice droplet generators. For recording droplet motion and the binary collision process with good spatial and temporal resolution high-speed shadow imaging was employed. The results for varied relative velocity and impact angle were assembled in impact parameter-Weber number maps. With increasing dynamic viscosity a characteristic displacement of the regimes for the different collision scenarios was also observed for pure liquids similar to that observed for solutions. This

  16. Comparing Productivity Simulated with Inventory Data Using Different Modelling Technologies

    Science.gov (United States)

    Klopf, M.; Pietsch, S. A.; Hasenauer, H.

    2009-04-01

    The Lime Stone National Park in Austria was established in 1997 to protect sensible lime stone soils from degradation due to heavy forest management. Since 1997 the management activities were successively reduced and standing volume and coarse woody debris (CWD) increased and degraded soils began to recover. One option to study the rehabilitation process towards natural virgin forest state is the use of modelling technology. In this study we will test two different modelling approaches for their applicability to Lime Stone National Park. We will compare standing tree volume simulated resulting from (i) the individual tree growth model MOSES, and (ii) the species and management sensitive adaptation of the biogeochemical-mechanistic model Biome-BGC. The results from the two models are compared with filed observations form repeated permanent forest inventory plots of the Lime Stone National Park in Austria. The simulated CWD predictions of the BGC-model were compared with dead wood measurements (standing and lying dead wood) recorded at the permanent inventory plots. The inventory was established between 1994 and 1996 and remeasured from 2004 to 2005. For this analysis 40 plots of this inventory were selected which comprise the required dead wood components and are dominated by a single tree species. First we used the distance dependant individual tree growth model MOSES to derive the standing timber and the amount of mortality per hectare. MOSES is initialized with the inventory data at plot establishment and each sampling plot is treated as forest stand. The Biome-BGC is a process based biogeochemical model with extensions for Austrian tree species, a self initialization and a forest management tool. The initialization for the actual simulations with the BGC model was done as follows: We first used spin up runs to derive a balanced forest vegetation, similar to an undisturbed forest. Next we considered the management history of the past centuries (heavy clear cuts

  17. Weather Research and Forecasting Model simulations of extended warm-season heavy precipitation episode over the US Southern Great Plains: data assimilation and microphysics sensitivity experiments

    Directory of Open Access Journals (Sweden)

    Zewdu T. Segele

    2013-07-01

    Full Text Available This study examines eight microphysics schemes (Lin, WSM5, Eta, WSM6, Goddard, Thompson, WDM5, WDM6 in the Advanced Research Weather Research and Forecasting Model (WRF-ARW for their reproduction of observed strong convection over the US Southern Great Plains (SGP for three heavy precipitation events of 27–31 May 2001. It also assesses how observational analysis nudging (OBNUD, three-dimensional (3DVAR and four-dimensional variational (4DVAR data assimilation (DA affect simulated cloud properties relative to simulations with no DA (CNTRL. Primary evaluation data were cloud radar reflectivity measurements by the millimetre cloud radar (MMCR at the Central Facility (CF of the SGP site of the ARM Climate Research Facility (ACRF. All WRF-ARW microphysics simulations reproduce the intensity and vertical structure of the first two major MMCR-observed storms, although the first simulated storm initiates a few hours earlier than observed. Of three organised convective events, the model best identifies the timing and vertical structure of the second storm more than 50 hours into the simulation. For this well-simulated cloud structure, simulated reflectivities are close to the observed counterparts in the mid- and upper troposphere, and only overestimate observed cloud radar reflectivity in the lower troposphere by less than 10 dBZ. Based on relative measures of skill, no single microphysics scheme excels in all aspects, although the WDM schemes show much-improved frequency bias scores (FBSs in the lower troposphere for a range of reflectivity thresholds. The WDM6 scheme has improved FBSs and high simulated-observed reflectivity correlations in the lower troposphere, likely due to its large production of liquid water immediately below the melting level. Of all the DA experiments, 3DVAR has the lowest mean errors (MEs and root mean-squared errors (RMSEs, although both the 3DVAR and 4DVAR simulations reduced noticeably the MEs for seven of eight

  18. Sex differences in the chronic mild stress model of depression.

    Science.gov (United States)

    Franceschelli, Anthony; Herchick, Samantha; Thelen, Connor; Papadopoulou-Daifoti, Zeta; Pitychoutis, Pothitos M

    2014-09-01

    A large volume of clinical and experimental evidence documents sex differences in brain anatomy, chemistry, and function, as well as in stress and drug responses. The chronic mild stress model (CMS) is one of the most extensively investigated animal models of chronic stress. However, only a limited number of studies have been conducted in female rodents despite the markedly higher prevalence of major depression among women. Herein, we review CMS studies conducted in rats and mice of both sexes and further discuss intriguing sex-dependent behavioral and neurobiological findings. The PubMed literature search engine was used to find and collect all relevant articles analyzed in this review. Specifically, a multitermed search was performed with 'chronic mild stress', 'chronic unpredictable stress' and 'chronic variable stress' as base terms and 'sex', 'gender', 'females' and 'depression' as secondary terms in various combinations. Male and female rodents appear to be differentially affected by CMS application, depending on the behavioral, physiological, and neurobiological indices that are being measured. Importantly, the CMS paradigm, despite its limitations, has been successfully used to assess a constellation of interdisciplinary research questions in the sex differences field and has served as a 'silver bullet' in assessing the role of sex in the neurobiology of major depression.

  19. Gas Deliverability Model with Different Vertical Wells Properties

    Directory of Open Access Journals (Sweden)

    L. Mucharam

    2003-11-01

    Full Text Available We present here a gas deliverability computational model for single reservoir with multi wells. The questions of how long the gas delivery can be sustained and how to estimate the plateau time are discussed here. In order to answer such a question, in this case, a coupling method which consists of material balance method and gas flow equation method is developed by assuming no water influx in the reservoir. Given the rate and the minimum pressure of gas at the processing plant, the gas pressure at the wellhead and at the bottom hole can be obtained. From here, the estimation of the gas deliverability can be done. In this paper we obtain a computational method which gives direct computation for pressure drop from the processing plant to the wells, taking into account different well behavior. Here AOF technique is used for obtaining gas rate in each well. Further Tian & Adewumi correlation is applied for pressure drop model along vertical and horizontal pipes and Runge-Kutta method is chosen to compute the well head and bottom hole pressures in each well which then being used to estimate the plateau times. We obtain here direct computational scheme of gas deliverability from reservoir to processing plant for single reservoir with multi-wells properties. Computational results give different profiles (i.e. gas rate, plateau and production time, etc for each well. Further by selecting proper flow rate reduction, the flow distribution after plateau time to sustain the delivery is computed for each well.

  20. Analysis of different training models for handball goalkeepers

    Directory of Open Access Journals (Sweden)

    Alejandro Muñoz Moreno

    2012-11-01

    Full Text Available The importance of the goalkeeper for the team performance is critical, however, publications on specific preparation are few in number, with no clear lines of work. The present study aims to analyze the different methodologies used in the specific training handball goalkeeper, by setting what the different training models as well as deepen the potential applications of each.For this purpose, it was conducted an extensive literature review, categorizing each document based on the performance factor on which prioritizes: physical-technical, perceptual and tactical. The analysis of results found that there were no other models than those categorized, being more numerous publications falling under physical and technical training, followed by the perceptive and very few exist on tactical training. In light of the results seems essential to conduct a specific training program for goalkeeper, taking into account the most relevant variables for optimal performance. No single factor seems more relevant to any stage of training, it being necessary to deepen it.Keywords: specific training, perception, decision making, tactical

  1. COMPARISON BETWEEN DIFFERENT MODELS FOR RHEOLOGICAL CHARACTERIZATION OF ACTIVATED SLUDGE

    Directory of Open Access Journals (Sweden)

    A. H. Khalili Garakani

    2011-09-01

    Full Text Available Activated sludge flow rheology is a very complicated phenomenon. Studies related to activated sludge tend to classify sludge as non-Newtonian fluid. Until now, several theories have been built to describe the complex behavior of activated sludge with varying degrees of success. In this article, seven different models for viscosity of non-Newtonian fluids (i.e., Power law, Bingham plastic, Herschel-Bulkley, Casson, Sisko, Carreau and Cross were considered to evaluate their predictive capability of apparent viscosity of activated sludge. Results showed that although evaluating the constants in the four-parameter models is difficult, they provide the best prediction of viscosity in the whole range of shear rates for activated sludge. For easier prediction of viscosity at different mixed liquor suspended solids (2.74-31g/L, temperature (15-25°C and shear rate (1-1000/s, simple correlations were proposed. Comparing the results with the experimental data revealed that the proposed correlations are in good agreement with real apparent viscosities.

  2. Broadband access network reference models: a different prospective

    Science.gov (United States)

    Mostafa, Mohamed S.

    1996-11-01

    The current view of the fiber-based broadband access network is that it could basically be modeled into two target networks represented by the following architectures, the fiber to the curb, building, home (FTTC/B/H) -- also termed switched digital video (SDV) -- architecture, and the hybrid fiber coax (HFC) architecture. Both architectures support on-demand digital services. One way to distinguish between these two architectures is based on the digital modulation scheme. The SDV/FTTC architecture utilizes baseband digital modulation both in the fiber distribution and the point-to- point drop. Whereas, the HFC architecture is pass-band and utilizes digitally modulated (as well as analog modulated) subcarriers both on the fiber and the coax for distribution to customers. From a network modeling point of view, the distinction between these two architectures is fuzzy. A hybrid between the above two architectures represents other architectural advantages especially bandwidth utilization in the upstream direction. This paper describes this hybrid architecture and provides an evaluation of the different access network configuration scenarios based on an expanded version of the DAVIC reference models.

  3. Comparison of CFD Simulation of a Hyundai I20 Model with Four Different Turbulence Models

    Directory of Open Access Journals (Sweden)

    Vivekanandan

    2016-07-01

    Full Text Available This article describes the CFD analysis of a Hyundai i20 car Model. The focus of this study is to investigate the aerodynamics characteristics of Hyundai i20 car model and the flow obtained by solving the steady-state governing continuity equations as well as the momentum conservation equations combined with one of four turbulence models (1.Spalart-Allmaras 2.k-ε Standard 3.Transition k-kl-ω 4.Transition Shear Stress Transport (SST and the solutions obtained using these different models were compared. Except transition k-kl-ω model, other three models show nearly similar velocity variations plot. Pressure variation plot are almost similar with K-ε and transition-SST models. Eddy viscosity plot are almost similar with K-ε and transition k-kl-ω models

  4. Does selection of mortality model make a difference in projecting population ageing?

    Directory of Open Access Journals (Sweden)

    Sergei Scherbov

    2016-01-01

    Full Text Available Background: In low mortality countries, assessing future ageing depends to a large extent on scenarios of future mortality reduction at old age. Often in population projections mortality reduction is implemented via life expectancy increases that do not specify mortality change at specific age groups. The selection of models that translate life expectancy into age-specific mortality rates may be of great importance for projecting the older age groups of future populations and indicators of ageing. Objective: We quantify how the selection of mortality models, assuming similar life expectancy scenarios, affects projected indices of population ageing. Methods: Using the cohort-component method, we project the populations of Italy, Japan, Russia, Sweden, and the USA. For each country, the given scenario of life expectancy at birth is translated into age-specific death rates by applying four alternative mortality models (variants of extrapolations of the log-mortality rates, the Brass relational model, and the Bongaarts shifting model. The models are contrasted according to their produced future age-specific mortality rates, population age composition, life expectancy at age 65, age at remaining life expectancy 15 years, and conventional and prospective old-age dependency ratios. Conclusions: We show strong differences between the alternative mortality models in terms of mortality age pattern and ageing indicators. Researchers of population ageing should be as careful about their choice of model of age patterns of future mortality as about scenarios of future life expectancy. The simultaneous extrapolation of age-specific death rates may be a better alternative to projecting life expectancy first and then deriving the age patterns of mortality in the second step.

  5. Dosha brain-types: A neural model of individual differences

    Directory of Open Access Journals (Sweden)

    Frederick T Travis

    2015-01-01

    Full Text Available This paper explores brain patterns associated with the three categories of regulatory principles of the body, mind, and behavior in Ayurveda, called Vata, Pitta, and Kapha dosha. A growing body of research has reported patterns of blood chemistry, genetic expression, physiological states, and chronic diseases associated with each dosha type. Since metabolic and growth factors are controlled by the nervous system, each dosha type should be associated with patterns of functioning of six major areas of the nervous system: The prefrontal cortex, the reticular activating system, the autonomic nervous system, the enteric nervous system, the limbic system, and the hypothalamus. For instance, the prefrontal cortex, which includes the anterior cingulate, ventral medial, and the dorsal lateral cortices, would exhibit a high range of functioning in the Vata brain-type leading to the possibility of being easily overstimulated. The Vata brain-type performs activity quickly. Learns quickly and forgets quickly. Their fast mind gives them an edge in creative problem solving. The Pitta brain-type reacts strongly to all challenges leading to purposeful and resolute actions. They never give up and are very dynamic and goal oriented. The Kapha brain-type is slow and steady leading to methodical thinking and action. They prefer routine and needs stimulation to get going. A model of dosha brain-types could provide a physiological foundation to understand individual differences. This model could help individualize treatment modalities to address different mental and physical dysfunctions. It also could explain differences in behavior seen in clinical as well as in normal populations.

  6. Comparison of different statistical modelling approaches for deriving spatial air temperature patterns in an urban environment

    Science.gov (United States)

    Straub, Annette; Beck, Christoph; Breitner, Susanne; Cyrys, Josef; Geruschkat, Uta; Jacobeit, Jucundus; Kühlbach, Benjamin; Kusch, Thomas; Richter, Katja; Schneider, Alexandra; Umminger, Robin; Wolf, Kathrin

    2017-04-01

    Frequently spatial variations of air temperature of considerable magnitude occur within urban areas. They correspond to varying land use/land cover characteristics and vary with season, time of day and synoptic conditions. These temperature differences have an impact on human health and comfort directly by inducing thermal stress as well as indirectly by means of affecting air quality. Therefore, knowledge of the spatial patterns of air temperature in cities and the factors causing them is of great importance, e.g. for urban planners. A multitude of studies have shown statistical modelling to be a suitable tool for generating spatial air temperature patterns. This contribution presents a comparison of different statistical modelling approaches for deriving spatial air temperature patterns in the urban environment of Augsburg, Southern Germany. In Augsburg there exists a measurement network for air temperature and humidity currently comprising 48 stations in the city and its rural surroundings (corporately operated by the Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health and the Institute of Geography, University of Augsburg). Using different datasets for land surface characteristics (Open Street Map, Urban Atlas) area percentages of different types of land cover were calculated for quadratic buffer zones of different size (25, 50, 100, 250, 500 m) around the stations as well for source regions of advective air flow and used as predictors together with additional variables such as sky view factor, ground level and distance from the city centre. Multiple Linear Regression and Random Forest models for different situations taking into account season, time of day and weather condition were applied utilizing selected subsets of these predictors in order to model spatial distributions of mean hourly and daily air temperature deviations from a rural reference station. Furthermore, the different model setups were

  7. Equivalence and Differences between Structural Equation Modeling and State-Space Modeling Techniques

    Science.gov (United States)

    Chow, Sy-Miin; Ho, Moon-ho R.; Hamaker, Ellen L.; Dolan, Conor V.

    2010-01-01

    State-space modeling techniques have been compared to structural equation modeling (SEM) techniques in various contexts but their unique strengths have often been overshadowed by their similarities to SEM. In this article, we provide a comprehensive discussion of these 2 approaches' similarities and differences through analytic comparisons and…

  8. Equivalence and Differences between Structural Equation Modeling and State-Space Modeling Techniques

    Science.gov (United States)

    Chow, Sy-Miin; Ho, Moon-ho R.; Hamaker, Ellen L.; Dolan, Conor V.

    2010-01-01

    State-space modeling techniques have been compared to structural equation modeling (SEM) techniques in various contexts but their unique strengths have often been overshadowed by their similarities to SEM. In this article, we provide a comprehensive discussion of these 2 approaches' similarities and differences through analytic comparisons and…

  9. Not so Great Lakes?

    Science.gov (United States)

    Showstack, Randy

    In 1965, Frank Sinatra won the Grammy Award for his album, "September of My Years;" "Early Bird," the first commercial communications satellite, was launched; and Dr. Martin Luther King, Jr. was arrested in Selma, Alabama, during demonstrations against voter-registration rules.The year 1965 was also the last time water levels in the U.S. Great Lakes were as low as they are now.

  10. Great Lakes Energy Institute

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, J. Iwan [Case Western Reserve Univ., Cleveland, OH (United States)

    2012-11-18

    The vision of the Great Lakes Energy Institute is to enable the transition to advanced, sustainable energy generation, storage, distribution and utilization through coordinated research, development, and education. The Institute will place emphasis on translating leading edge research into next generation energy technology. The Institute’s research thrusts focus on coordinated research in decentralized power generation devices (e.g. fuel cells, wind turbines, solar photovoltaic devices), management of electrical power transmission and distribution, energy storage, and energy efficiency.

  11. Understanding Differences in Chemistry Climate Model Projections of Stratospheric Ozone

    Science.gov (United States)

    Douglass, A. R.; Strahan, S. E.; Oman, L. D.; Stolarski, R. S.

    2014-01-01

    Chemistry climate models (CCMs) are used to project future evolution of stratospheric ozone as concentrations of ozone-depleting substances (ODSs) decrease and greenhouse gases increase, cooling the stratosphere. CCM projections exhibit not only many common features but also a broad range of values for quantities such as year of ozone return to 1980 and global ozone level at the end of the 21st century. Multiple linear regression is applied to each of 14 CCMs to separate ozone response to ODS concentration change from that due to climate change. We show that the sensitivity of lower stratospheric ozone to chlorine change Delta Ozone/Delta inorganic chlorine is a near-linear function of partitioning of total inorganic chlorine into its reservoirs; both inorganic chlorine and its partitioning are largely controlled by lower stratospheric transport. CCMs with best performance on transport diagnostics agree with observations for chlorine reservoirs and produce similar ozone responses to chlorine change. After 2035, differences in Delta Ozone/Delta inorganic chlorine contribute little to the spread in CCM projections as the anthropogenic contribution to inorganic chlorine becomes unimportant. Differences among upper stratospheric ozone increases due to temperature decreases are explained by differences in ozone sensitivity to temperature change Delta Ozone/Delta T due to different contributions from various ozone loss processes, each with its own temperature dependence. Ozone decrease in the tropical lower stratosphere caused by a projected speedup in the Brewer-Dobson circulation may or may not be balanced by ozone increases in the middle- and high-latitude lower stratosphere and upper troposphere. This balance, or lack thereof, contributes most to the spread in late 21st century projections.

  12. Finite-difference modeling of commercial aircraft using TSAR

    Energy Technology Data Exchange (ETDEWEB)

    Pennock, S.T.; Poggio, A.J.

    1994-11-15

    Future aircraft may have systems controlled by fiber optic cables, to reduce susceptibility to electromagnetic interference. However, the digital systems associated with the fiber optic network could still experience upset due to powerful radio stations, radars, and other electromagnetic sources, with potentially serious consequences. We are modeling the electromagnetic behavior of commercial transport aircraft in support of the NASA Fly-by-Light/Power-by-Wire program, using the TSAR finite-difference time-domain code initially developed for the military. By comparing results obtained from TSAR with data taken on a Boeing 757 at the Air Force Phillips Lab., we hope to show that FDTD codes can serve as an important tool in the design and certification of U.S. commercial aircraft, helping American companies to produce safe, reliable air transportation.

  13. Phreatophytic vegetation and groundwater fluctuations: a review of current research and application of ecosystem response modeling with an emphasis on great basin vegetation.

    Science.gov (United States)

    Naumburg, Elke; Mata-Gonzalez, Ricardo; Hunter, Rachael G; McLendon, Terry; Martin, David W

    2005-06-01

    Although changes in depth to groundwater occur naturally, anthropogenic alterations may exacerbate these fluctuations and, thus, affect vegetation reliant on groundwater. These effects include changes in physiology, structure, and community dynamics, particularly in arid regions where groundwater can be an important water source for many plants. To properly manage ecosystems subject to changes in depth to groundwater, plant responses to both rising and falling groundwater tables must be understood. However, most research has focused exclusively on riparian ecosystems, ignoring regions where groundwater is available to a wider range of species. Here, we review responses of riparian and other species to changes in groundwater levels in arid environments. Although decreasing water tables often result in plant water stress and reduced live biomass, the converse is not necessarily true for rising water tables. Initially, rising water tables kill flooded roots because most species cannot tolerate the associated low oxygen levels. Thus, flooded plants can also experience water stress. Ultimately, individual species responses to either scenario depend on drought and flooding tolerance and the change in root system size and water uptake capacity. However, additional environmental and biological factors can play important roles in the severity of vegetation response to altered groundwater tables. Using the reviewed information, we created two conceptual models to highlight vegetation dynamics in areas with groundwater fluctuations. These models use flow charts to identify key vegetation and ecosystem properties and their responses to changes in groundwater tables to predict community responses. We then incorporated key concepts from these models into EDYS, a comprehensive ecosystem model, to highlight the potential complexity of predicting community change under different fluctuating groundwater scenarios. Such models provide a valuable tool for managing vegetation and

  14. [Postoperative metabolic acidosis: use of three different fluid therapy models].

    Science.gov (United States)

    Tellan, Guglielmo; Antonucci, Adriana; Marandola, Maurizio; Naclerio, Michele; Fiengo, Leslie; Molinari, Stefania; Delogu, Giovanna

    2008-01-01

    Intraoperative fluid administration is considered an important factor in the management of metabolic acidosis following surgical procedures. The aim of this study was to compare three types of intraoperative infusional models in order to evaluate their effect on acid-base changes in the immediate postoperative period as calculated by both the Henderson-Hasselbach equation and the Stewart approach. Forty-seven patients undergoing left hemicolectomy were enrolled in the study and assigned randomly to receiving 0.9% saline alone (Group A, n=16), lactated Ringer's solution alone (Group B, n=16) or 0.9% saline and Ringer's solution, 1:1 ratio (Group C, n=15). Arterial blood samples were taken before operation (t0) and 30 min after extubation (t1) in order to measure the acid-base balance. The results showed a metabolic acidosis status in Group A patients, whereas Group B exhibited metabolic alkalosis only by means of the Stewart method. No difference was found in Group C between the time points t0 and t1 when using either the Henderson-Hasselbach equation or using the Stewart model. We conclude that saline solution in association with Ringer's solution (1:1 ratio) appears to be the most suitable form of intraoperative fluid management in order to guarantee a stable acid-base balance in selected surgical patients during the immediate postoperative period.

  15. Considerations for modeling thin cirrus effects via brightness temperature differences

    Science.gov (United States)

    Schmidt, E. O.; Arduini, R. F.; Wielicki, B. A.; Stone, R. S.; Tsay, S.-C.

    1995-01-01

    Brightness temperature difference (BTD) values are calculated for selected Geostationary Operational Environmental Satellite (GOES-6) channels (3.9, 12.7 micrometer) and Advanced Very High Resolution Radiometer channels (3.7, 12.0 micrometer). Daytime and nighttime discrimination of particle size information is possible given the infrared cloud extinction optical depth and the BTD value. BTD values are presented and compared for cirrus clouds composed of equivalent ice spheres (volume, surface area) versus randomly oriented hexagonal ice crystals. The effect of the hexagonal ice crystals is to increase the magnitude of the BTD values calculated relative to equivalent ice sphere (volume, surface area) BTDs. Equivalent spheres (volume or surface area) do not do a very good job of modeling hexagonal ice crystal effects on BTDs; however, the use of composite spheres improves the simulation and offers interesting prospects. Careful consideration of the number of Legendre polynomial coefficients used to fit the scattering phase functions is crucial to realistic modeling of cirrus BTDs. Surface and view-angle effects are incorporated to provide more realistic simulation.

  16. Critical Differences of Asymmetric Magnetic Reconnection from Standard Models

    Science.gov (United States)

    Nitta, S.; Wada, T.; Fuchida, T.; Kondoh, K.

    2016-09-01

    We have clarified the structure of asymmetric magnetic reconnection in detail as the result of the spontaneous evolutionary process. The asymmetry is imposed as ratio k of the magnetic field strength in both sides of the initial current sheet (CS) in the isothermal equilibrium. The MHD simulation is carried out by the HLLD code for the long-term temporal evolution with very high spatial resolution. The resultant structure is drastically different from the symmetric case (e.g., the Petschek model) even for slight asymmetry k = 2. (1) The velocity distribution in the reconnection jet clearly shows a two-layered structure, i.e., the high-speed sub-layer in which the flow is almost field aligned and the acceleration sub-layer. (2) Higher beta side (HBS) plasma is caught in a lower beta side plasmoid. This suggests a new plasma mixing process in the reconnection events. (3) A new large strong fast shock in front of the plasmoid forms in the HBS. This can be a new particle acceleration site in the reconnection system. These critical properties that have not been reported in previous works suggest that we contribute to a better and more detailed knowledge of the reconnection of the standard model for the symmetric magnetic reconnection system.

  17. Contraction preconditioner in finite-difference electromagnetic modeling

    Science.gov (United States)

    Yavich, Nikolay; Zhdanov, Michael S.

    2016-06-01

    This paper introduces a novel approach to constructing an effective preconditioner for finite-difference (FD) electromagnetic modeling in geophysical applications. This approach is based on introducing an FD contraction operator, similar to one developed for integral equation formulation of Maxwell's equation. The properties of the FD contraction operator were established using an FD analog of the energy equality for the anomalous electromagnetic field. A new preconditioner uses a discrete Green's function of a 1D layered background conductivity. We also developed the formulas for an estimation of the condition number of the system of FD equations preconditioned with the introduced FD contraction operator. Based on this estimation, we have established that for high contrasts, the condition number is bounded by the maximum conductivity contrast between the background conductivity and actual conductivity. When there are both resistive and conductive anomalies relative to the background, the new preconditioner is advantageous over using the 1D discrete Green's function directly. In our numerical experiments with both resistive and conductive anomalies, for a land geoelectrical model with 1:10 contrast, the method accelerates convergence of an iterative method (BiCGStab) by factors of 2 to 2.5, and in a marine example with 1:50 contrast, by a factor of 4.6, compared to direct use of the discrete 1D Green's function as a preconditioner.

  18. Contraction pre-conditioner in finite-difference electromagnetic modelling

    Science.gov (United States)

    Yavich, Nikolay; Zhdanov, Michael S.

    2016-09-01

    This paper introduces a novel approach to constructing an effective pre-conditioner for finite-difference (FD) electromagnetic modelling in geophysical applications. This approach is based on introducing an FD contraction operator, similar to one developed for integral equation formulation of Maxwell's equation. The properties of the FD contraction operator were established using an FD analogue of the energy equality for the anomalous electromagnetic field. A new pre-conditioner uses a discrete Green's function of a 1-D layered background conductivity. We also developed the formulae for an estimation of the condition number of the system of FD equations pre-conditioned with the introduced FD contraction operator. Based on this estimation, we have established that the condition number is bounded by the maximum conductivity contrast between the background conductivity and actual conductivity. When there are both resistive and conductive anomalies relative to the background, the new pre-conditioner is advantageous over using the 1-D discrete Green's function directly. In our numerical experiments with both resistive and conductive anomalies, for a land geoelectrical model with 1:10 contrast, the method accelerates convergence of an iterative method (BiCGStab) by factors of 2-2.5, and in a marine example with 1:50 contrast, by a factor of 4.6, compared to direct use of the discrete 1-D Green's function as a pre-conditioner.

  19. Exploring female mice interstrain differences relevant for models of depression

    Directory of Open Access Journals (Sweden)

    Daniela de Sá Calçada

    2015-12-01

    Full Text Available Depression is an extremely heterogeneous disorder. Diverse molecular mechanisms have been suggested to underlie its etiology. To understand the molecular mechanisms responsible for this complex disorder, researchers have been using animal models extensively, namely mice from various genetic backgrounds and harboring distinct genetic modifications. The use of numerous mouse models has contributed to enrich our knowledge on depression. However, accumulating data also revealed that the intrinsic characteristics of each mouse strain might influence the experimental outcomes, which may justify some conflicting evidence reported in the literature. To further understand the impact of the genetic background we performed a multimodal comparative study encompassing the most relevant parameters commonly addressed in depression in three of the most widely used mouse strains: Balb/c, C57BL/6 and CD-1. Moreover, female mice were selected for this study taken into account the higher prevalence of depression in woman and the fewer animal studies using this gender. Our results show that Balb/c mice have a more pronounced anxious-like behavior than CD-1 and C57BL/6 mice, whereas C57BL/6 animals present the strongest depressive-like trait. Furthermore, C57BL/6 mice display the highest rate of proliferating cells and brain-derived neurotrophic factor expression levels in the hippocampus, while hippocampal dentate granular neurons of Balb/c mice show smaller dendritic lengths and fewer ramifications. Of notice, the expression levels of inducible nitric oxide synthase (iNos predict 39,5% of the depressive-like behavior index, which suggests a key role of hippocampal iNOS in depression.Overall, this study reveals important interstrain differences in several behavioral dimensions and molecular and cellular parameters that should be considered when preparing and analyzing experiments addressing depression using mouse models. It further contributes to the literature by

  20. The peer model advantage in infants’ imitation of familiar gestures performed by differently aged models

    Directory of Open Access Journals (Sweden)

    Norbert eZmyj

    2012-07-01

    Full Text Available Research on infant´s imitation of differently aged models, which has predominantly studied object- related actions, has so far lead to mixed evidence. Whereas some studies reported an increased likelihood of imitating peer models in contrast to adult models, other studies reported the opposite pattern of results. In the present study, 14-month-old infants were presented with four familiar gestures (e.g., clapping that were demonstrated by differently aged televised models (peer, older child, adult. Results revealed that infants were more likely to imitate the peer model than the older child or the adult. This result is discussed with respect to a social function of imitation and the cognitive mechanism of imitating familiar behavior.

  1. Landscape-scale modeling of water quality in Lake Superior and Lake Michigan watersheds: How useful are forest-based indicators? Journal of Great Lakes Research

    Science.gov (United States)

    Titus S. Seilheimer; Patrick L. Zimmerman; Kirk M. Stueve; Charles H. Perry

    2013-01-01

    The Great Lakes watersheds have an important influence on the water quality of the nearshore environment, therefore, watershed characteristics can be used to predict what will be observed in the streams. We used novel landscape information describing the forest cover change, along with forest census data and established land cover data to predict total phosphorus and...

  2. A sensitivity analysis using different spatial resolution terrain models and flood inundation models

    Science.gov (United States)

    Papaioannou, George; Aronica, Giuseppe T.; Loukas, Athanasios; Vasiliades, Lampros

    2014-05-01

    The impact of terrain spatial resolution and accuracy on the hydraulic flood modeling can pervade the water depth and the flood extent accuracy. Another significant factor that can affect the hydraulic flood modeling outputs is the selection of the hydrodynamic models (1D,2D,1D/2D). Human mortality, ravaged infrastructures and other damages can be derived by extreme flash flood events that can be prevailed in lowlands at suburban and urban areas. These incidents make the necessity of a detailed description of the terrain and the use of advanced hydraulic models essential for the accurate spatial distribution of the flooded areas. In this study, a sensitivity analysis undertaken using different spatial resolution of Digital Elevation Models (DEMs) and several hydraulic modeling approaches (1D, 2D, 1D/2D) including their effect on the results of river flow modeling and mapping of floodplain. Three digital terrain models (DTMs) were generated from the different elevation variation sources: Terrestrial Laser Scanning (TLS) point cloud data, classic land surveying and digitization of elevation contours from 1:5000 scale topographic maps. HEC-RAS and MIKE 11 are the 1-dimensional hydraulic models that are used. MLFP-2D (Aronica et al., 1998) and MIKE 21 are the 2-dimensional hydraulic models. The last case consist of the integration of MIKE 11/MIKE 21 where 1D-MIKE 11 and 2D-MIKE 21 hydraulic models are coupled through the MIKE FLOOD platform. The validation process of water depths and flood extent is achieved through historical flood records. Observed flood inundation areas in terms of simulated maximum water depth and flood extent were used for the validity of each application result. The methodology has been applied in the suburban section of Xerias river at Volos-Greece. Each dataset has been used to create a flood inundation map for different cross-section configurations using different hydraulic models. The comparison of resulting flood inundation maps indicates

  3. Spatial Distribution of the Errors in Modeling the Mid-Latitude Critical Frequencies by Different Models

    Science.gov (United States)

    Kilifarska, N. A.

    There are some models that describe the spatial distribution of greatest frequency yielding reflection from the F2 ionospheric layer (foF2). However, the distribution of the models' errors over the globe and how they depend on seasons, solar activity, etc., are unknown till this time. So the aim of the present paper is to compare the accuracy in describing the latitudinal and longitudinal variation of the mid-latitude maximum electron density, of CCIR, URSI, and a new created theoretical model. A comparison between the above mentioned models and all available from Boulder's data bank VI data (among 35 deg and 70 deg) have been made. Data for three whole years with different solar activity - 1976 (F_10.7 = 73.6), 1981 (F_10.7 = 20.6), 1983 (F_10.7 = 119.6) have been compared. The final results show that: 1. the areas with greatest and smallest errors depend on UT, season and solar activity; 2. the error distribution of CCIR and URSI models are very similar and are not coincident with these ones of theoretical model. The last result indicates that the theoretical model, described briefly bellow, may be a real alternative to the empirical CCIR and URSI models. The different spatial distribution of the models' errors gives a chance for the users to choose the most appropriate model, depending on their needs. Taking into account that the theoretical models have equal accuracy in region with many or without any ionosonde station, this result shows that our model can be used to improve the global mapping of the mid-latitude ionosphere. Moreover, if Re values of the input aeronomical parameters (neutral composition, temperatures and winds), are used - it may be expected that this theoretical model can be applied for Re or almost Re-time mapping of the main ionospheric parameters (foF2 and hmF2).

  4. Bayesian model averaging in vector autoregressive processes with an investigation of stability of the US great ratios and risk of a liquidity trap in the USA, UK and Japan

    NARCIS (Netherlands)

    R.W. Strachan (Rodney); H.K. van Dijk (Herman)

    2007-01-01

    textabstractA Bayesian model averaging procedure is presented within the class of vector autoregressive (VAR) processes and applied to two empirical issues. First, stability of the "Great Ratios" in U.S. macro-economic time series is investigated, together with the presence and e¤ects of permanent s

  5. Evaluation and QSAR modeling on multiple endpoints of estrogen activity based on different bioassays.

    Science.gov (United States)

    Liu, Huanxiang; Papa, Ester; Gramatica, Paola

    2008-02-01

    There is a great need for an effective means of rapidly assessing endocrine-disrupting activity, especially estrogen-simulating activity, due to the large number of chemicals that have serious adverse effects on the environment. Many approaches using a variety of biological screening assays are used to identify endocrine disrupting chemicals. The present investigation analyzes the consistency and peculiarity of information from different experimental assays collected from a literature survey, by studying the correlation of the different endpoints. In addition, the activity values of more widely used selected bioassays have been combined by principle components analysis (PCA) to build one cumulative endpoint, the estrogen activity index (EAI), for priority setting to identify chemicals most likely possessing estrogen activity for early entry into screening. This index was then modeled using only a few theoretical molecular descriptors. The constructed MLR-QSAR model has been statistically validated for its predictive power, and can be proposed as a preliminary evaluative method to screen/prioritize estrogens according to their integrated estrogen activity, just starting from molecular structure.

  6. Idiopathic great saphenous phlebosclerosis.

    Directory of Open Access Journals (Sweden)

    Ahmadreza Jodati

    2013-06-01

    Full Text Available Arterial sclerosis has been extensively described but reports on venous sclerosis are very sparse. Phlebosclerosis refers to the thickening and hardening of the venous wall. Despite its morphological similarities with arteriosclerosis and potential morbid consequences, phlebosclerosis has gained only little attention. We report a 72 year old male with paralysis and atrophy of the right leg due to childhood poliomyelitis who was referred for coronary artery bypass surgery. The great saphenous vein, harvested from the left leg, showed a hardened cord-like obliterated vein. Surprisingly, harvested veins from the atrophic limb were normal and successfully used for grafting.

  7. 'Great Power Style' in China's Economic Policy

    DEFF Research Database (Denmark)

    Jiang, Yang

    2011-01-01

    China’s ascendance attracts concern, even though Beijing claims to be a responsible great power and tries to demonstrate its ‘great power style’ in economic diplomacy. This article therefore discusses the following questions: to what extent does the current notion and practice of Chinese ‘great...... power style’ in economic diplomacy comply with, or differ from, the criteria of benign hegemony; and what are the major constraining factors? Conceptually, China’s ‘great power style’ is rooted in ancient Chinese political philosophy and institution, but it highly resembles the Western notion of benign...... and economic interests....

  8. A ROADMAP FOR GENERATING SEMANTICALLY ENRICHED BUILDING MODELS ACCORDING TO CITYGML MODEL VIA TWO DIFFERENT METHODOLOGIES

    Directory of Open Access Journals (Sweden)

    G. Floros

    2016-10-01

    Full Text Available The methodologies of 3D modeling techniques have increasingly increased due to the rapid advances of new technologies. Nowadays, the focus of 3D modeling software is focused, not only to the finest visualization of the models, but also in their semantic features during the modeling procedure. As a result, the models thus generated are both realistic and semantically enriched. Additionally, various extensions of modeling software allow for the immediate conversion of the model’s format, via semi-automatic procedures with respect to the user’s scope. The aim of this paper is to investigate the generation of a semantically enriched Citygml building model via two different methodologies. The first methodology includes the modeling in Trimble SketchUp and the transformation in FME Desktop Manager, while the second methodology includes the model’s generation in CityEngine and its transformation in the CityGML format via the 3DCitiesProject extension for ArcGIS. Finally, the two aforesaid methodologies are being compared and specific characteristics are evaluated, in order to infer the methodology that is best applied depending on the different projects’ purposes.

  9. Soft sensor modelling by time difference, recursive partial least squares and adaptive model updating

    Science.gov (United States)

    Fu, Y.; Yang, W.; Xu, O.; Zhou, L.; Wang, J.

    2017-04-01

    To investigate time-variant and nonlinear characteristics in industrial processes, a soft sensor modelling method based on time difference, moving-window recursive partial least square (PLS) and adaptive model updating is proposed. In this method, time difference values of input and output variables are used as training samples to construct the model, which can reduce the effects of the nonlinear characteristic on modelling accuracy and retain the advantages of recursive PLS algorithm. To solve the high updating frequency of the model, a confidence value is introduced, which can be updated adaptively according to the results of the model performance assessment. Once the confidence value is updated, the model can be updated. The proposed method has been used to predict the 4-carboxy-benz-aldehyde (CBA) content in the purified terephthalic acid (PTA) oxidation reaction process. The results show that the proposed soft sensor modelling method can reduce computation effectively, improve prediction accuracy by making use of process information and reflect the process characteristics accurately.

  10. Smart structures: modeling, analysis, and control with different strategies

    Science.gov (United States)

    Ghareeb, Nader; Gaith, Mohamed; Soleimani, Sayed

    2017-04-01

    Weight optimization of structures can result in lower stiffness and less internal damping, causing the structure to become excessively prone to vibration. To overcome this problem, active or smart materials are implemented. The coupled electromechanical properties of smart materials, used in the form of piezoelectric ceramics in this work, make these materials well-suited for being implemented as distributed sensors and actuators to control the structural response. The smart structure proposed in this paper is composed of a cantilevered steel beam, an adhesive or bonding layer, and a piezoelectric actuator. The static deflection of the structure is derived as function of the piezoelectric voltage, and the outcome is compared to theoretical and experimental results from literature. The relation between the voltage and the piezoelectric moment at both ends of the actuator is also investigated and a reduced finite element model of the smart structure is created and verified. Finally, different linear controllers are implemented and its ability to attenuate the vibration due to the first Eigen frequency is demonstrated.

  11. The Great Recession, unemployment and suicide.

    Science.gov (United States)

    Norström, Thor; Grönqvist, Hans

    2015-02-01

    How have suicide rates responded to the marked increase in unemployment spurred by the Great Recession? Our paper puts this issue into a wider perspective by assessing (1) whether the unemployment-suicide link is modified by the degree of unemployment protection, and (2) whether the effect on suicide of the present crisis differs from the effects of previous economic downturns. We analysed the unemployment-suicide link using time-series data for 30 countries spanning the period 1960-2012. Separate fixed-effects models were estimated for each of five welfare state regimes with different levels of unemployment protection (Eastern, Southern, Anglo-Saxon, Bismarckian and Scandinavian). We included an interaction term to capture the possible excess effect of unemployment during the Great Recession. The largest unemployment increases occurred in the welfare state regimes with the least generous unemployment protection. The unemployment effect on male suicides was statistically significant in all welfare regimes, except the Scandinavian one. The effect on female suicides was significant only in the eastern European country group. There was a significant gradient in the effects, being stronger the less generous the unemployment protection. The interaction term capturing the possible excess effect of unemployment during the financial crisis was not significant. Our findings suggest that the more generous the unemployment protection the weaker the detrimental impact on suicide of the increasing unemployment during the Great Recession. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  12. Great Britain at CERN

    CERN Multimedia

    2006-01-01

    From 14 to 16 November 2006 Administration Building, Bldg. 60/61 - ground and 1st floor 09.30 - 17.30 Fifteen companies will present their latest technologies at the 'Great Britain at CERN' exhibition. British industry will exhibit products and technologies related to the field of particle physics. The main fields represented will be computing technologies, electrical engineering, electronics, mechanical engineering, vacuum & low temperature technologies and particle detectors. The exhibition is organised by BEAMA Exhibitions (the British Electrotechnical and Allied Manufacturers Association). Below you will find: a list of the exhibitors. A detailed programme will be available in due course: from your Departmental secretariat, from the Reception information desk, Building 33, at the exhibition itself. A detailed list of the companies is available at the following FI link: http://fi-dep.web.cern.ch/fi-dep/structure/memberstates/exhibitions_visits.htm LIST OF EXHIBITORS 3D Metrics Alma...

  13. Great Britain at CERN

    CERN Multimedia

    2006-01-01

    From 14 to 16 November 2006 Administration Building, Bldg. 60/61 - ground and 1st floor 09.30 - 17.30 Fifteen companies will present their latest technologies at the 'Great Britain at CERN' exhibition. British industry will exhibit products and technologies related to the field of particle physics. The main fields represented will be computing technologies, electrical engineering, electronics, mechanical engineering, vacuum & low temperature technologies and particle detectors. The exhibition is organised by BEAMA Exhibitions (the British Electrotechnical and Allied Manufacturers Association). Below you will find: a list of the exhibitors. A detailed programme will be available in due course: from your Departmental secretariat, from the Reception information desk, Building 33, at the exhibition itself. A detailed list of the companies is available at the following FI link: http://fi-dep.web.cern.ch/fi-dep/structure/memberstates/exhibitions_visits.htm LIST OF EXHIBITORS 3D Metrics Almat...

  14. The Great Scientists

    Science.gov (United States)

    Meadows, Jack

    1989-11-01

    This lively history of the development of science and its relationship to society combines vivid biographies of twelve pivotal scientists, commentary on the social and historical events of their time, and over four hundred illustrations, including many in color. The biographies span from classical times to the Atomic Age, covering Aristotle, Galileo, Harvey, Newton, Lavoisier, Humboldt, Faraday, Darwin, Pasteur, Curie, Freud, and Einstein. Through the biographies and a wealth of other material, the volume reveals how social forces have influenced the course of science. Along with the highly informative color illustrations, it contains much archival material never before published, ranging from medieval woodcuts, etchings from Renaissance anatomy texts, and pages from Harvey's journal, to modern false-color x-rays and infrared photographs of solar flares. A beautifully-designed, fact-filled, stimulating work, The Great Scientists will fascinate anyone with an interest in science and how history can influence scientific discovery.

  15. Comparative Study of Path Loss Models in Different Environments

    Directory of Open Access Journals (Sweden)

    Tilotma Yadav,

    2011-04-01

    Full Text Available By using propagation path models to estimate the received signal level as a function of distance, it becomes possible to predict the SNR for a mobile communication system. Both theoretical andmeasurement-based propagation models indicate that average received signal power decreases logarithmically with distance. For comparative analysis we use Okumura’s model, Hata model, COST231 Extension to Hata model,ECEC-33 model,SUI model along with the practical data. Most of these models are based on a systematic interpretation of theoretical data service area like urban(Built-up city or largetown crowded with large buildings, suburban (having some obstacles near the mobile radio car, but still not very congested and rural (No obstacles like tall trees or buildings like farm-land, rice field, open fields in INDIA at 900MHz & 1800MHz frequency .

  16. Aspect-Oriented Modelling from a Different Angle

    DEFF Research Database (Denmark)

    Kindler, Ekkart; Schmelter, David

    2008-01-01

    In this paper, we report on a new approach of aspect-oriented modelling, which is particularly suited for domains with naturally born aspects as part of that domain: MoDowA for Modelling Domains with Aspects. Though these models are on a very high level of abstraction and could be made early in t...

  17. Distinguishing Antimicrobial Models with Different Resistance Mechanisms via Population Pharmacodynamic Modeling.

    Directory of Open Access Journals (Sweden)

    Matthieu Jacobs

    2016-03-01

    Full Text Available Semi-mechanistic pharmacokinetic-pharmacodynamic (PK-PD modeling is increasingly used for antimicrobial drug development and optimization of dosage regimens, but systematic simulation-estimation studies to distinguish between competing PD models are lacking. This study compared the ability of static and dynamic in vitro infection models to distinguish between models with different resistance mechanisms and support accurate and precise parameter estimation. Monte Carlo simulations (MCS were performed for models with one susceptible bacterial population without (M1 or with a resting stage (M2, a one population model with adaptive resistance (M5, models with pre-existing susceptible and resistant populations without (M3 or with (M4 inter-conversion, and a model with two pre-existing populations with adaptive resistance (M6. For each model, 200 datasets of the total bacterial population were simulated over 24h using static antibiotic concentrations (256-fold concentration range or over 48h under dynamic conditions (dosing every 12h; elimination half-life: 1h. Twelve-hundred random datasets (each containing 20 curves for static or four curves for dynamic conditions were generated by bootstrapping. Each dataset was estimated by all six models via population PD modeling to compare bias and precision. For M1 and M3, most parameter estimates were unbiased (<10% and had good imprecision (<30%. However, parameters for adaptive resistance and inter-conversion for M2, M4, M5 and M6 had poor bias and large imprecision under static and dynamic conditions. For datasets that only contained viable counts of the total population, common statistical criteria and diagnostic plots did not support sound identification of the true resistance mechanism. Therefore, it seems advisable to quantify resistant bacteria and characterize their MICs and resistance mechanisms to support extended simulations and translate from in vitro experiments to animal infection models and

  18. Enhancing the laccase production and laccase gene expression in the white-rot fungus Trametes velutina 5930 with great potential for biotechnological applications by different metal ions and aromatic compounds.

    Science.gov (United States)

    Yang, Yang; Wei, Fuxiang; Zhuo, Rui; Fan, Fangfang; Liu, Huahua; Zhang, Chen; Ma, Li; Jiang, Mulan; Zhang, Xiaoyu

    2013-01-01

    Laccase is useful for various biotechnological and industrial applications. The white-rot fungus Trametes velutina 5930 and its laccase, isolated from the Shennongjia Nature Reserve in China by our laboratory, has great potential for practical application in environmental biotechnology. However, the original level of laccase produced by Trametes velutina 5930 was relatively low in the absence of any inducer. Therefore, in order to enhance the laccase production by Trametes velutina 5930 and make better use of this fungus in the field of environmental biotechnology, the regulation of laccase production and laccase gene expression in Trametes velutina 5930 were investigated in this study. Different metal ions such as Cu(2+) and Fe(2+) could stimulate the laccase synthesis and laccase gene transcription in Trametes velutina 5930. Some aromatic compounds structurally related to lignin, such as tannic acid, syringic acid, cinnamic acid, gallic acid and guaiacol, could also enhance the level of laccase activity and laccase gene transcription. We also found that there existed a positive synergistic effect of aromatic compound and metal ion on the laccase production and laccase gene transcription in Trametes velutina 5930. Taken together, our study may contribute to the improvement of laccase productivity by Trametes velutina 5930.

  19. Enhancing the laccase production and laccase gene expression in the white-rot fungus Trametes velutina 5930 with great potential for biotechnological applications by different metal ions and aromatic compounds.

    Directory of Open Access Journals (Sweden)

    Yang Yang

    Full Text Available Laccase is useful for various biotechnological and industrial applications. The white-rot fungus Trametes velutina 5930 and its laccase, isolated from the Shennongjia Nature Reserve in China by our laboratory, has great potential for practical application in environmental biotechnology. However, the original level of laccase produced by Trametes velutina 5930 was relatively low in the absence of any inducer. Therefore, in order to enhance the laccase production by Trametes velutina 5930 and make better use of this fungus in the field of environmental biotechnology, the regulation of laccase production and laccase gene expression in Trametes velutina 5930 were investigated in this study. Different metal ions such as Cu(2+ and Fe(2+ could stimulate the laccase synthesis and laccase gene transcription in Trametes velutina 5930. Some aromatic compounds structurally related to lignin, such as tannic acid, syringic acid, cinnamic acid, gallic acid and guaiacol, could also enhance the level of laccase activity and laccase gene transcription. We also found that there existed a positive synergistic effect of aromatic compound and metal ion on the laccase production and laccase gene transcription in Trametes velutina 5930. Taken together, our study may contribute to the improvement of laccase productivity by Trametes velutina 5930.

  20. Model of the PCB and mercury exposure of mink and great blue heron inhabiting the off-site environment downstream from the US Department of Energy Oak Ridge Reservation. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    MacIntosh, D.L. [Indiana Univ., Bloomington, IN (United States). School of Public and Environmental Affairs; Suter, G.W. II; Hoffman, F.O. [Oak Ridge National Lab., TN (United States)

    1992-09-01

    This report presents a pair of wildlife exposure models developed for use in investigating the risks to wildlife of releases of mercury and PCBS. The species modeled are the great blue heron and mink The models may be used to estimate the exposure experienced by mink and herons, to help establish remedial action goals and to identify research needs. Because mercury and PCBs bioaccumulate through dietary uptake, the models simulate the food webs supporting the two species. Sources of contaminants include surface water, sediment, sediment pore water, and soil. The model are stochastic equilibrium models. Two types of variance in the input parameters are distinguished: stochastic variance among individual mink and herons and ignorance concerning true parameter values. The variance in the output due to stochastic parameters indicates the expected variance among the receptors. The variance due to ignorance indicates the extent to which the model outputs could be unpaved by additional sampling and measurement. The results of the models were compared to concentrations measured in great blue heron eggs and nestlings from colonies on the Clinch and Tennessee Rivers. The predicted concentrations agreed well with the measured concentrations. In addition, the variances in measured values among individuals was approximately equal to the total stochastic variance predicted by the models.

  1. Model of the PCB and mercury exposure of mink and great blue heron inhabiting the off-site environment downstream from the US Department of Energy Oak Ridge Reservation

    Energy Technology Data Exchange (ETDEWEB)

    MacIntosh, D.L. (Indiana Univ., Bloomington, IN (United States). School of Public and Environmental Affairs); Suter, G.W. II; Hoffman, F.O. (Oak Ridge National Lab., TN (United States))

    1992-09-01

    This report presents a pair of wildlife exposure models developed for use in investigating the risks to wildlife of releases of mercury and PCBS. The species modeled are the great blue heron and mink The models may be used to estimate the exposure experienced by mink and herons, to help establish remedial action goals and to identify research needs. Because mercury and PCBs bioaccumulate through dietary uptake, the models simulate the food webs supporting the two species. Sources of contaminants include surface water, sediment, sediment pore water, and soil. The model are stochastic equilibrium models. Two types of variance in the input parameters are distinguished: stochastic variance among individual mink and herons and ignorance concerning true parameter values. The variance in the output due to stochastic parameters indicates the expected variance among the receptors. The variance due to ignorance indicates the extent to which the model outputs could be unpaved by additional sampling and measurement. The results of the models were compared to concentrations measured in great blue heron eggs and nestlings from colonies on the Clinch and Tennessee Rivers. The predicted concentrations agreed well with the measured concentrations. In addition, the variances in measured values among individuals was approximately equal to the total stochastic variance predicted by the models.

  2. Ethnic differences in the effects of media on body image: the effects of priming with ethnically different or similar models.

    Science.gov (United States)

    Bruns, Gina L; Carter, Michele M

    2015-04-01

    Media exposure has been positively correlated with body dissatisfaction. While body image concerns are common, being African American has been found to be a protective factor in the development of body dissatisfaction. Participants either viewed ten advertisements showing 1) ethnically-similar thin models; 2) ethnically-different thin models; 3) ethnically-similar plus-sized models; and 4) ethnically-diverse plus-sized models. Following exposure, body image was measured. African American women had less body dissatisfaction than Caucasian women. Ethnically-similar thin-model conditions did not elicit greater body dissatisfaction scores than ethnically-different thin or plus-sized models nor did the ethnicity of the model impact ratings of body dissatisfaction for women of either race. There were no differences among the African American women exposed to plus-sized versus thin models. Among Caucasian women exposure to plus-sized models resulted in greater body dissatisfaction than exposure to thin models. Results support existing literature that African American women experience less body dissatisfaction than Caucasian women even following exposure to an ethnically-similar thin model. Additionally, women exposed to plus-sized model conditions experienced greater body dissatisfaction than those shown thin models. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Modeling elk and bison carrying capacity for Great Sand Dunes National Park, Baca National Wildlife Refuge, and The Nature Conservancy's Medano Ranch, Colorado

    Science.gov (United States)

    Wockner, Gary; Boone, Randall; Schoenecker, Kathryn A.; Zeigenfuss, Linda C.

    2015-01-01

    Great Sand Dunes National Park and Preserve and the neighboring Baca National Wildlife Refuge constitute an extraordinary setting that offers a variety of opportunities for outdoor recreation and natural resource preservation in the San Luis Valley of Colorado. Adjacent to these federal lands, the Nature Conservancy (TNC) manages the historic Medano Ranch. The total land area of these three conservation properties is roughly 121,500 hectares (ha). It is a remote and rugged area in which resource managers must balance the protection of natural resources with recreation and neighboring land uses. The management of wild ungulates in this setting presents challenges, as wild ungulates move freely across public and private landscapes.

  4. A spatial individual-based model predicting a great impact of copious sugar sources and resting sites on survival of Anopheles gambiae and malaria parasite transmission

    Science.gov (United States)

    Zhu, Lin; Qualls, Whitney A.; Marshall, John M; Arheart, Kris L.; DeAngelis, Don; McManus, John W.; Traore, Sekou F.; Doumbia, Seydou; Schlein, Yosef; Muller, Gunter C.; Beier, John C.

    2015-01-01

    BackgroundAgent-based modelling (ABM) has been used to simulate mosquito life cycles and to evaluate vector control applications. However, most models lack sugar-feeding and resting behaviours or are based on mathematical equations lacking individual level randomness and spatial components of mosquito life. Here, a spatial individual-based model (IBM) incorporating sugar-feeding and resting behaviours of the malaria vector Anopheles gambiae was developed to estimate the impact of environmental sugar sources and resting sites on survival and biting behaviour.MethodsA spatial IBM containing An. gambiae mosquitoes and humans, as well as the village environment of houses, sugar sources, resting sites and larval habitat sites was developed. Anopheles gambiae behaviour rules were attributed at each step of the IBM: resting, host seeking, sugar feeding and breeding. Each step represented one second of time, and each simulation was set to run for 60 days and repeated 50 times. Scenarios of different densities and spatial distributions of sugar sources and outdoor resting sites were simulated and compared.ResultsWhen the number of natural sugar sources was increased from 0 to 100 while the number of resting sites was held constant, mean daily survival rate increased from 2.5% to 85.1% for males and from 2.5% to 94.5% for females, mean human biting rate increased from 0 to 0.94 bites per human per day, and mean daily abundance increased from 1 to 477 for males and from 1 to 1,428 for females. When the number of outdoor resting sites was increased from 0 to 50 while the number of sugar sources was held constant, mean daily survival rate increased from 77.3% to 84.3% for males and from 86.7% to 93.9% for females, mean human biting rate increased from 0 to 0.52 bites per human per day, and mean daily abundance increased from 62 to 349 for males and from 257 to 1120 for females. All increases were significant (P < 0.01). Survival was greater when sugar sources were randomly

  5. An effective model for dynamic finite difference calculations

    Energy Technology Data Exchange (ETDEWEB)

    Dey, T.N.

    1996-01-01

    An effective stress model, which simulates the mechanical effects of pore fluids on deformation and strength of porous materials, is described. The model can directly use SESAME table equations-of-state (EOSs) for the solid and fluid components. the model assumes that undrained (no fluid flow) conditions occur. Elastic and crushing behavior of the pore space can be specified from the results of simple laboratory tests. The model fully couples deviatoric and volumetric behavior in the sense that deviatoric and tensile failure depend on the effective pressure, while volumetric changes caused by deviatoric failure are coupled back to the volumetric behavior of the material. Strain hardening and softening of the yield surface, together with a number of flow rules, can be modeled. This model has been implemented into the SMC123 and CTH codes.

  6. Investigating Different ZnO Arresters Models against Transient Waves

    Directory of Open Access Journals (Sweden)

    A. Babaee

    2011-12-01

    Full Text Available Metal oxide surge arresters have dynamic characteristics that are significant for over voltage coordination studies involving fast front surges. Several models with acceptable accuracy have been proposed to simulate this frequency-dependent behavior. In this paper, various electrical models are presented for surge arrester performance simulation against lightning impulse. The desirable model is obtained by using simulation results of the existing models and experimental tests. The IEEE proposed model is a proportional model can give satisfactory results for discharge currents within a range of time to crest for 0.5 to 45 :s but due to no existing residual voltage resulting switching current on the manufacture's datasheets decrease its performance generally. In this study the maximum residual voltage due to current impulse is analyzed too. In additional, the amount of discharged energy by surge arrester is focused.

  7. Comparisons between different models for thermal simulation of GTAW process

    Institute of Scientific and Technical Information of China (English)

    Xu Yanli; Wei Yanhong

    2005-01-01

    Two mathematical models are built to study the effects of the fluid flow on thermal distributions of the gas tungsten arc welding(GTAW) process. One model is based on the heat conductivity equation, which doesn' t take the effects of the fluid flow into account, and the other couples the laminar heat transfer and fluid flow in the weld pool, which is called laminar fluid flow model in short. The simulated results of the two models show that the pattern and velocity of the fluid flow play a critical role in determining the thermal distribution and the weld pool shape. For the laminar fluid flow model, its highest temperature is 400 K lower than that calculated with the other model and the depth of its weld pool is shallower too, which is mainly caused by the main vortex of the flow in the weld pool.

  8. A model of individual differences in learning air traffic control

    NARCIS (Netherlands)

    Taatgen, NA; Altmann, EM; Cleeremans, A; Schunn, CD; Gray, WD

    2001-01-01

    Individual differences in skill acquisition are influenced by several architectural factors. According to Ackerman's theory, general intelligence, speed of proceduralization and psychomotor speed influence different stages of skill acquisition. Ackerman tested this theory by correlating performance

  9. Lithium-ion battery aging mechanisms and life model under different charging stresses

    Science.gov (United States)

    Gao, Yang; Jiang, Jiuchun; Zhang, Caiping; Zhang, Weige; Ma, Zeyu; Jiang, Yan

    2017-07-01

    The charging time-consuming and lifespan of lithium-ion batteries have always been the bottleneck for the tremendous application of electric vehicles. In this paper, cycle life tests are conducted to reveal the influence of different charging current rates and cut-off voltages on the aging mechanism of batteries. The long-term effects of charging current rates and cut-off voltages on capacity degradation and resistance increase are compared. The results show that there exists a critical charging current and a critical charging cut-off voltage. When the charging stress exceeds the critical value, battery degradation speed will be greatly accelerated. Furthermore, battery aging mechanisms at various charging currents and cut-off voltages are investigated using incremental capacity analysis. It is indicated that charging current and cut-off voltage should be reduced to retard battery degradation when the battery degrades to a certain extent. The time when the loss of electrode material accelerates is taken as the crisis to reduce charging current and the time when the loss of lithium inventory accelerates is taken as the crisis to reduce charging cut-off voltage. Moreover, an experiential model quantitatively describing the relationship between capacity degradation rate and charging stresses at different aging states is established.

  10. Sensitivity Analysis of the Land Surface Model NOAH-MP for Different Model Fluxes

    Science.gov (United States)

    Mai, Juliane; Thober, Stephan; Samaniego, Luis; Branch, Oliver; Wulfmeyer, Volker; Clark, Martyn; Attinger, Sabine; Kumar, Rohini; Cuntz, Matthias

    2015-04-01

    and (c) latent heat are calculated on twelve Model Parameter Estimation Experiment (MOPEX) catchments ranging in size from 1020 to 4421 km2. This allows investigation of parametric sensitivities for distinct hydro-climatic characteristics, emphasizing different land-surface processes. The sequential screening identifies the most informative parameters of NOAH-MP for different model output variables. The number of parameters is reduced substantially for all of the three model outputs to approximately 25. The subsequent Sobol method quantifies the sensitivities of these informative parameters. The study demonstrates the existence of sensitive, important parameters in almost all parts of the model irrespective of the considered output. Soil parameters, e.g., are informative for all three output variables whereas plant parameters are not only informative for latent heat but also for soil drainage because soil drainage is strongly coupled to transpiration through the soil water balance. These results contrast to the choice of only soil parameters in hydrological studies and only plant parameters in biogeochemical ones. The sequential screening identified several important hidden parameters that carry large sensitivities and have hence to be included during model calibration.

  11. Application of different models to the lactation curve of unimproved ...

    African Journals Online (AJOL)

    m. merih

    estimated using the Cubic model was very close to total milk yield calculated by the ... This has made the Wood model the most widely used function for the description .... study region is best in May with respect to grazing capacity. ... summer months in dairy cattle and for those cows beginning at low milk yields and reaching ...

  12. Prediction of benzodiazepines solubility using different cosolvency models.

    Science.gov (United States)

    Nokhodchi, A; Shokri, J; Barzegar-Jalali, M; Ghafourian, T

    2002-07-01

    The solubility of four benzodiazepines (BZPs) including diazepam (DIZ), lorazepam (LRZ) clonazepam (CLZ), and chlordiazepoxide (CHZ) in water-cosolvent (ethanol propylene glycol and polyethylene glycol 200) binary systems were studied. In general, increasing the volume fraction of cosolvents resulted in an increase in the solubility of benzodiazepines. The mole fraction solubilities were fitted to the various cosolvency models, namely extended Hildebrand approach (EHA), excess free energy (EFE), combined nearly ideal binary solvent/Redlich-Kister (CNIBS/R-K), general single model (GSM), mixture response surface (MR-S). double log-log (DL-L), and linear double log-log (LDL-L). The results showed that DL-L model was the best model in predicting the solubility of all drugs in all the water-cosolvent mixtures (OAE% = 4.71). The minimum and maximum errors were observed for benzodiazepine's solubility in water-propylene glycol and water-ethanol mixtures which were 2.67 and 11.78%, respectively. Three models (EFE, CNIBS/R-K and LDL-L) were chosen as general models for solubility descriptions of these structurally similar drugs in each of the solvent systems. Among these models, the EFE model was the best in predicting the solubility of benzodiazepines in binary solvent mixtures (OAE% = 11.19).

  13. Modelling clinical systemic lupus erythematosus: similarities, differences and success stories.

    Science.gov (United States)

    Celhar, Teja; Fairhurst, Anna-Marie

    2016-12-24

    Mouse models of SLE have been indispensable tools to study disease pathogenesis, to identify genetic susceptibility loci and targets for drug development, and for preclinical testing of novel therapeutics. Recent insights into immunological mechanisms of disease progression have boosted a revival in SLE drug development. Despite promising results in mouse studies, many novel drugs have failed to meet clinical end points. This is probably because of the complexity of the disease, which is driven by polygenic predisposition and diverse environmental factors, resulting in a heterogeneous clinical presentation. Each mouse model recapitulates limited aspects of lupus, especially in terms of the mechanism underlying disease progression. The main mouse models have been fairly successful for the evaluation of broad-acting immunosuppressants. However, the advent of targeted therapeutics calls for a selection of the most appropriate model(s) for testing and, ultimately, identification of patients who will be most likely to respond.

  14. Modelling clinical systemic lupus erythematosus: similarities, differences and success stories

    Science.gov (United States)

    Celhar, Teja

    2017-01-01

    Abstract Mouse models of SLE have been indispensable tools to study disease pathogenesis, to identify genetic susceptibility loci and targets for drug development, and for preclinical testing of novel therapeutics. Recent insights into immunological mechanisms of disease progression have boosted a revival in SLE drug development. Despite promising results in mouse studies, many novel drugs have failed to meet clinical end points. This is probably because of the complexity of the disease, which is driven by polygenic predisposition and diverse environmental factors, resulting in a heterogeneous clinical presentation. Each mouse model recapitulates limited aspects of lupus, especially in terms of the mechanism underlying disease progression. The main mouse models have been fairly successful for the evaluation of broad-acting immunosuppressants. However, the advent of targeted therapeutics calls for a selection of the most appropriate model(s) for testing and, ultimately, identification of patients who will be most likely to respond. PMID:28013204

  15. Development of a distributed biosphere hydrological model and its evaluation with the Southern Great Plains Experiments (SGP97 and SGP99)

    Science.gov (United States)

    A distributed biosphere hydrological model, the so called water and energy budget-based distributed hydrological model (WEB-DHM), has been developed by fully coupling a biosphere scheme (SiB2) with a geomorphology-based hydrological model (GBHM). SiB2 describes the transfer of turbulent fluxes (ener...

  16. Geoarchaeology of water management at Great Zimbabwe

    DEFF Research Database (Denmark)

    Sulas, Federica; Pikirayi, Innocent; Sagiya, Munyaradzi Elton

    In Africa, research on water management in urban contexts has often focussed rainfall, and the occurrence floods and droughts, whereas small-scale catchment systems and soil moisture regimes have received far less attention. This paper sets out to re-address the issue by examining the occurrence...... management of water resources over the last thousand years or so. These findings call for a rethinking of current models of urban evolutions in the region. More importantly, this study illustrates the need for integrating different datasets at multiple spatial and temporal scales to address people-water......, distribution and use of multiple water resources at the ancient urban landscape of Great Zimbabwe. Here, the rise and demise of the urban site have been linked to changing rainfall in the 1st mill. AD. Accordingly, rainfall shortages and consequent droughts eventually leading to the decline and abandonment...

  17. Quantitative Methods for Comparing Different Polyline Stream Network Models

    Energy Technology Data Exchange (ETDEWEB)

    Danny L. Anderson; Daniel P. Ames; Ping Yang

    2014-04-01

    Two techniques for exploring relative horizontal accuracy of complex linear spatial features are described and sample source code (pseudo code) is presented for this purpose. The first technique, relative sinuosity, is presented as a measure of the complexity or detail of a polyline network in comparison to a reference network. We term the second technique longitudinal root mean squared error (LRMSE) and present it as a means for quantitatively assessing the horizontal variance between two polyline data sets representing digitized (reference) and derived stream and river networks. Both relative sinuosity and LRMSE are shown to be suitable measures of horizontal stream network accuracy for assessing quality and variation in linear features. Both techniques have been used in two recent investigations involving extracting of hydrographic features from LiDAR elevation data. One confirmed that, with the greatly increased resolution of LiDAR data, smaller cell sizes yielded better stream network delineations, based on sinuosity and LRMSE, when using LiDAR-derived DEMs. The other demonstrated a new method of delineating stream channels directly from LiDAR point clouds, without the intermediate step of deriving a DEM, showing that the direct delineation from LiDAR point clouds yielded an excellent and much better match, as indicated by the LRMSE.

  18. Modeling large offshore wind farms under different atmospheric stability regimes with the Park wake model

    DEFF Research Database (Denmark)

    Pena Diaz, Alfredo; Réthoré, Pierre-Elouan; Rathmann, Ole

    2014-01-01

    We evaluate a modified version of the Park wake model against power data from a west-east row in the middle of the Horns Rev I offshore wind farm. The evaluation is performed on data classified in four different atmospheric stability conditions, for a narrow wind speed range, and a wide range of ...... are different. The ensemble average of the simulations does not approach the limits of the infinite wind farm under any stability condition as such averages account for directions misaligned with the row....

  19. MODELING OF THE BEHAVIOUR REOLOGICHESKIH TEL UNDER DIFFERENT LAW NAGRUZHENIYA

    Directory of Open Access Journals (Sweden)

    V. V. Bendyukov

    2014-01-01

    Full Text Available The Offered model of the behaviour reologicheskogo bodies (the viscous-elasticity of the materia, designs or systems under controlling influence of the load, acting on given law for some time.

  20. Sevoflurane Remifentanil Interaction Comparison of Different Response Surface Models

    NARCIS (Netherlands)

    Heyse, Bjorn; Proost, Johannes H.; Schumacher, Peter M.; Bouillon, Thomas W.; Vereecke, Hugo E. M.; Eleveld, Douglas J.; Luginbuehl, Martin; Struys, Michel M. R. F.

    2012-01-01

    Background: Various pharmacodynamic response surface models have been developed to quantitatively describe the relationship between two or more drug concentrations with their combined clinical effect. We examined the interaction of remifentanil and sevoflurane on the probability of tolerance to shak

  1. Randall-Sundrum models vs. supersymmetry. The different flavor signatures

    Energy Technology Data Exchange (ETDEWEB)

    Gori, Stefania

    2010-07-15

    The Minimal Supersymmetric Standard Model based on flavor symmetries and models with a warped extra dimension as first proposed by Randall and Sundrum represent two of the best founded theories beyond the Standard Model. They provide two appealing solutions both to the gauge hierarchy problem and to the Standard Model flavor hierarchy problems. In this thesis we focus on a particular Randall-Sundrum model based on the custodial symmetry SU(2){sub L} x SU(2){sub R} x P{sub LR} in the bulk and on two Supersymmetric flavor models: the one based on a U(1) abelian flavor symmetry, the other on a SU(3) non abelian flavor symmetry. We first analyze and compare the flavor structure of the two frameworks, showing two possible ways to address the New Physics flavor problem: warped geometry and custodial protection vs. flavor symmetry. Subsequently, we study the impact of the new particles (Kaluza-Klein states in the Randall-Sundrum model and superpartners in Supersymmetry) in the K and B meson mixings and rare decays. We perform a global numerical analysis of the new physics effects in the models in question and we show that it is possible to naturally be in agreement with all the available data on {delta}F=2 observables, even fixing the energy scale of the models to the TeV range, in order to have new particles in the reach of the LHC. We then study distinctive patterns of flavor violation which can enable future experiments to distinguish the two frameworks. In particular, the specific correlations between the CP violating asymmetry in the B{sub s}{sup 0}- anti B{sub s}{sup 0} system, the rare decays B{sub s,d}{yields}{mu}{sup +}{mu}{sup -} and K{yields}{pi}{nu}anti {nu} allow in principle for an experimental test of the Randall-Sundrum model and of the two Supersymmetric flavor models and a clear distinction between the two frameworks, once new data will be available. (orig.)

  2. The structure of common fears: comparing three different models.

    Science.gov (United States)

    de Jongh, Ad; Oosterink, Floor M D; Kieffer, Jacobien M; Hoogstraten, Johan; Aartman, Irene H A

    2011-01-01

    Previous studies showed discrepant findings regarding the factor structure of common fears. The purpose of the present study was to expand on these findings and contribute to the development of a descriptive framework for a fear classification. Using data from the Dutch general population (n = 961; 50.9% women), an exploratory factor analysis was performed to delineate the multidimensional structure of 11 common fears previously used in a factor analytic study by Fredrikson, Annas, Fischer, and Wik (1996). An independent sample (n = 998; 48.3% women) was used to confirm the newly derived model by means of confirmatory factor analysis. In addition, the model was tested against the DSM-IV-TR model and a model found earlier by Fredrikson et al. (1996). Although support was found for a 3-factor solution consisting of a blood-injection-injury factor, a situational-animal factor, and a height-related factor, confirmatory factor analysis showed that this 3-factor model and the DSM-IV-TR 4-factor model fitted the data equally well. The findings suggest that the structure of subclinical fears can be inferred from the DSM classification of phobia subtypes and that fears and phobias are two observable manifestations of a fear response along a continuum.

  3. Modelling of pretreatment and saccharification with different feedstocks and kinetic modeling of sorghum saccharification.

    Science.gov (United States)

    Prathyusha, N; Kamesh, Reddi; Rani, K Yamuna; Sumana, C; Sridhar, S; Prakasham, R S; Yashwanth, V V N; Sheelu, G; Kumar, M Pradeep

    2016-12-01

    Experiments have been performed for pretreatment of sorghum, wheat straw and bamboo through high temperature alkali pretreatment with different alkaline loading and temperatures, and the data on extent of delignification in terms of the final compositions of cellulose, hemicellulose and lignin have been generated. Further, enzymatic saccharification has been carried out in all the cases to find the extent of conversion possible after 72h. The effect of different operating parameters on the extent of delignification and cellulose conversion are evaluated. This data is employed to develop a generalized multi-feedstock and individual feedstock based models which can be used to determine the extent of delignification and cellulose conversion for any and specific biomass respectively with alkaline pretreatment and similar enzyme conditions as considered in the present study. Also, a kinetic model is developed and validated for sorghum for cellulosic conversion.

  4. The Development of Sex Differences in Aggression: A Revised Model.

    Science.gov (United States)

    Hyde, Janet S.; Schuck, John R.

    In response to Maccoby and Jacklin's (1974) conclusion that sex differences in aggression must be biological in origin, we suggest alternative social-learning mechanisms to explain the differences. These mechanisms include: (1) punishment for aggression increases aggression in boys, particularly because boys do not identify with the punisher; (2)…

  5. Modeling large offshore wind farms under different atmospheric stability regimes with the Park wake model

    DEFF Research Database (Denmark)

    Peña, Alfredo; Réthoré, Pierre-Elouan; Rathmann, Ole

    2013-01-01

    Here, we evaluate a modified version of the Park wake model against power data from a west-east row in the middle of the Horns Rev I offshore wind farm. The evaluation is performed on data classified in four different atmospheric stability conditions, for a narrow wind speed range, and a wide ran....... The simulations do not approach the limits of the infinite wind farm under any stability condition as winds are not parallel to the row....

  6. Great Lakes Environmental Database (GLENDA)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Great Lakes Environmental Database (GLENDA) houses environmental data on a wide variety of constituents in water, biota, sediment, and air in the Great Lakes area.

  7. Modelling tidal influence on sea breezes with models of different complexity

    Directory of Open Access Journals (Sweden)

    Jana Fischereit

    2016-09-01

    Full Text Available Tides influence both the formation and development of sea breezes. The aim of this study is to investigate the tidal influence to decide which model complexity is needed to reproduce the main influence of tides in a numerical model of coastal meteorology. Two processes are considered: (a the influence of tides on sea breezes through the effect of tidal currents on the surface wind and (b the thermal influence through the flooding and drying of mudflats in the intertidal area. The processes are considered separately by representing the ocean in the non-hydrostatic mesoscale atmosphere model METRAS with different complexity, ranging from a homogeneous stationary surface to a shallow-water model coupled to METRAS with a two-way exchange of momentum. The model system is applied in a case study to the German Bight, where large mudflats exist at low tide.The results show that the main influence of tides originates from a change in the mudflat heat budget through flooding and drying. The influence of tidal currents on the surface wind is small. Therefore, we conclude that no coupled atmosphere-ocean model is needed to reproduce the main influence of tides on sea breezes in a numerical model. Instead, we suggest to use an atmosphere model which simulates the change of surface cover in the intertidal area and includes a realistic spatial sea surface temperature distribution. For this it is essential to simulate the change in surface cover with the correct timing because the results show that the atmosphere reacts very sensitively to that change.

  8. Using the Rasch model as an objective and probabilistic technique to integrate different soil properties

    Science.gov (United States)

    Rebollo, Francisco J.; Jesús Moral García, Francisco

    2016-04-01

    Soil apparent electrical conductivity (ECa) is one of the simplest, least expensive soil measurements that integrates many soil properties affecting crop productivity, including, for instance, soil texture, water content, and cation exchange capacity. The ECa measurements obtained with a 3100 Veris sensor, operating in both shallow (0-30 cm), ECs, and deep (0-90 cm), ECd, mode, can be used as an additional and essential information to be included in a probabilistic model, the Rasch model, with the aim of quantifying the overall soil fertililty potential in an agricultural field. This quantification should integrate the main soil physical and chemical properties, with different units. In this work, the formulation of the Rasch model integrates 11 soil properties (clay, silt and sand content, organic matter -OM-, pH, total nitrogen -TN-, available phosphorus -AP- and potassium -AK-, cation exchange capacity -CEC-, ECd, and ECs) measured at 70 locations in a field. The main outputs of the model include a ranking of all soil samples according to their relative fertility potential and the unexpected behaviours of some soil samples and properties. In the case study, the considered soil variables fit the model reasonably, having an important influence on soil fertility, except pH, probably due to its homogeneity in the field. Moreover, ECd, ECs are the most influential properties on soil fertility and, on the other hand, AP and AK the less influential properties. The use of the Rasch model to estimate soil fertility potential (always in a relative way, taking into account the characteristics of the studied soil) constitutes a new application of great practical importance, enabling to rationally determine locations in a field where high soil fertility potential exists and establishing those soil samples or properties which have any anomaly; this information can be necessary to conduct site-specific treatments, leading to a more cost-effective and sustainable field

  9. Squares of different sizes: effect of geographical projection on model parameter estimates in species distribution modeling.

    Science.gov (United States)

    Budic, Lara; Didenko, Gregor; Dormann, Carsten F

    2016-01-01

    In species distribution analyses, environmental predictors and distribution data for large spatial extents are often available in long-lat format, such as degree raster grids. Long-lat projections suffer from unequal cell sizes, as a degree of longitude decreases in length from approximately 110 km at the equator to 0 km at the poles. Here we investigate whether long-lat and equal-area projections yield similar model parameter estimates, or result in a consistent bias. We analyzed the environmental effects on the distribution of 12 ungulate species with a northern distribution, as models for these species should display the strongest effect of projectional distortion. Additionally we choose four species with entirely continental distributions to investigate the effect of incomplete cell coverage at the coast. We expected that including model weights proportional to the actual cell area should compensate for the observed bias in model coefficients, and similarly that using land coverage of a cell should decrease bias in species with coastal distribution. As anticipated, model coefficients were different between long-lat and equal-area projections. Having progressively smaller and a higher number of cells with increasing latitude influenced the importance of parameters in models, increased the sample size for the northernmost parts of species ranges, and reduced the subcell variability of those areas. However, this bias could be largely removed by weighting long-lat cells by the area they cover, and marginally by correcting for land coverage. Overall we found little effect of using long-lat rather than equal-area projections in our analysis. The fitted relationship between environmental parameters and occurrence probability differed only very little between the two projection types. We still recommend using equal-area projections to avoid possible bias. More importantly, our results suggest that the cell area and the proportion of a cell covered by land should be

  10. Combating Combination of Hypertension and Diabetes in Different Rat Models

    Directory of Open Access Journals (Sweden)

    Talma Rosenthal

    2010-03-01

    Full Text Available Rat experimental models are used extensively for studying physiological mechanisms and treatments of hypertension and diabetes co-existence. Each one of these conditions is a major risk factor for cardiovascular disease (CVD, and the combination of the two conditions is a potent enhancer of CVD. Five major animal models that advanced our understanding of the mechanisms and therapeutic approaches in humans are discussed in this review: Zucker, Goto-Kakizaki, SHROB, SHR/NDmcr-cp and Cohen Rosenthal diabetic hypertensive (CRDH rats. The use of various drugs, such as angiotensin-converting enzyme (ACE inhibitors (ACEIs, various angiotensin receptor blockers (ARBs, and calcium channel blockers (CCBs, to combat the effects of concomitant pathologies on the combination of diabetes and hypertension, as well as the non-pharmacological approach are reviewed in detail for each rat model. Results from experiments on these models indicate that classical factors contributing to the pathology of hypertension and diabetes combination—Including hypertension, hyperglycemia, hyperinsulinemia and hyperlipidemia—can now be treated, although these treatments do not completely prevent renal complications. Animal studies have focused on several mechanisms involved in hypertension/diabetes that remain to be translated into clinical medicine, including hypoxia, oxidative stress, and advanced glycation. Several target molecules have been identified that need to be incorporated into a treatment modality. The challenge continues to be the identification and interpretation of the clinical evidence from the animal models and their application to human treatment.

  11. Different Higgs models and the number of Higgs particles

    Energy Technology Data Exchange (ETDEWEB)

    Marek-Crnjac, L. [University of Maribor, Faculty of Mechanical Engineering, Smetanova ulica 17, SI-2000 Maribor (Slovenia)] e-mail: fs.taj06@uni-mb.si

    2006-02-01

    In this short paper we discuss some interesting Higgs models. It is concluded that the most likely scheme for the Higgs particles consists of five physical Higgs particles. These are two charged H{sup +}, H{sup -} and three neutrals h {sup 0}, H{sup 0}, A{sup 0}. Further more the most probably total number of elementary particles for each model is calculated [El Naschie MS. Experimental and theoretical arguments for the number of the mass of the Higgs particles. Chaos, Solitons and Fractals 2005;23:1091-8; El Naschie MS. Determining the mass of the Higgs and the electroweak bosons. Chaos, Solitons and Fractals 2005;24:899-905; El Naschie MS. On 366 kissing spheres in 10 dimensions, 528 P-Brane states in 11 dimensions and the 60 elementary particles of the standard model. Chaos, Solitons and Fractals 2005;24:447-57].

  12. A parametric study of the thermal performance of green roofs in different climates through energy modeling

    Science.gov (United States)

    Mukherjee, Sananda

    In recent years, there has been great interest in the potential of green roofs as an alternative roofing option to reduce the energy consumed by individual buildings as well as mitigate large scale urban environmental problems such as the heat island effect. There is a widespread recognition and a growing literature of measured data that suggest green roofs can reduce building energy consumption. This thesis investigates the potential of green roofs in reducing the building energy loads and focuses on how the different parameters of a green roof assembly affect the thermal performance of a building. A green roof assembly is modeled in Design Builder- a 3D graphical design modeling and energy use simulation program (interface) that uses the EnergyPlus simulation engine, and the simulated data set thus obtained is compared to field experiment data to validate the roof assembly model on the basis of how accurately it simulates the behavior of a green roof. Then the software is used to evaluate the thermal performance of several green roof assemblies under three different climate types, looking at the whole building energy consumption. For the purpose of this parametric simulation study, a prototypical single story small office building is considered and one parameter of the green roof is altered for each simulation run in order to understand its effect on building's energy loads. These parameters include different insulation thicknesses, leaf area indices (LAI) and growing medium or soil depth, each of which are tested under the three different climate types. The energy use intensities (EUIs), the peak and annual heating and cooling loads resulting from the use of these green roof assemblies are compared with each other and to a cool roof base case to determine the energy load reductions, if any. The heat flux through the roof is also evaluated and compared. The simulation results are then organized and finally presented as a decision support tool that would

  13. MATLAB/Simulink Based Study of Different Approaches Using Mathematical Model of Differential Equations

    National Research Council Canada - National Science Library

    Vijay Nehra

    2014-01-01

    .... The present paper addresses different approaches used to derive mathematical models of first and second order system, developing MATLAB script implementation and building a corresponding Simulink model...

  14. Permeation of PLGA nanoparticles across different in vitro models

    CSIR Research Space (South Africa)

    Nkabinde, LA

    2012-07-01

    Full Text Available nanoparticles across different membranes and showed that although Rhodamine 6 G-labelled nanoparticles are efficiently delivered across the intestinal epithelium, its epithelial permeability changes when a drug such as isoniazid is encapsulated. Future studies...

  15. Antiulcerogenic activity of zinc acexamate in different experimental models.

    Science.gov (United States)

    Escolar, G; Camarasa, J; Navarro, C; Vernetta, C; Bulbena, O

    1987-07-01

    The antiulcerogenic activity of zinc acexamate (ZAC; Laboratorios Viñas, S.A.) has been tested in several models of gastric injury induced by acid hypersecretion, prostaglandin blockade and disruption of the gastric barrier. Lowest doses which have demonstrated to significantly prevent gastric damage ranged from 10 to 100 mg/kg depending on the experimental model used. The benefit obtained with this compound was always dose-dependent. These findings would support the hypothesis that ZAC acts by a complex inhibition of several of the mechanisms involved in the development of peptic diseases.

  16. Standard Cost Model: Three Different Paths and their Common Problems

    Directory of Open Access Journals (Sweden)

    Jacopo Torriti

    2011-12-01

    Full Text Available Red tape is not desirable as it impedes business growth. Relief from the administrative burdens that businesses face due to legislation can benefit the whole economy, especially at times of recession. However, recent governmental initiatives aimed at reducing administrative burdens have encountered some success, but also failures. This article compares three national initiatives – in the Netherlands, UK and Italy - aimed at cutting red tape by using the Standard Cost Model. Findings highlight the factors affecting the outcomes of measurement and reduction plans and ways to improve the Standard Cost Model methodology.

  17. Analyzing Differences in Operational Disease Definitions Using Ontological Modeling

    OpenAIRE

    Peelen, Linda; Klein, Michel; Schlobach, Stefan; Keizer, de, Rob J.W.; Peek, Niels

    2007-01-01

    In medicine, there are many diseases which cannot be precisely characterized but are considered as natural kinds. In the communication between health care professionals, this is generally not problematic. In biomedical research, however, crisp definitions are required to unambiguously distinguish patients with and without the disease. In practice, this results in different operational definitions being in use for a single disease. This paper presents an approach to compare different operation...

  18. Analyzing Differences in Operational Disease Definitions Using Ontological Modeling

    OpenAIRE

    Peelen, Linda; Klein, Michel; Schlobach, Stefan; Keizer, de, M.; Peek,Niels

    2007-01-01

    In medicine, there are many diseases which cannot be precisely characterized but are considered as natural kinds. In the communication between health care professionals, this is generally not problematic. In biomedical research, however, crisp definitions are required to unambiguously distinguish patients with and without the disease. In practice, this results in different operational definitions being in use for a single disease. This paper presents an approach to compare different operation...

  19. Design and Modelling of Different SRAM'S Based on CNTFET 32NM Technology

    Directory of Open Access Journals (Sweden)

    Naagesh. S. Bhat

    2012-02-01

    Full Text Available Carbon nano tube field-effect transistor (CNTFET refers to a field-effect transistor that utilizes a single carbon nano tube or an array of carbon nano tubes as the channel material instead of bulk silicon in the traditional MOSFET structure. Since it was first demonstrated in 1998, there have been tremendous developments in CNTFETs, which promise for an alternative material to replace silicon in future electronics. Carbon nano tubes are promising materials for the nano-scale electron devices such as nano tube FETs for ultra-high density integrated circuits and quantum-effect devices for novel intelligent circuits, which are expected to bring a breakthrough in the present silicon technology. A Static Random Access Memory (SRAM is designed to plug two needs: i The SRAM provides as cache memory, communicating between central processing unit and Dynamic Random Access Memory (DRAM. ii The SRAM technology act as driving force for low power application since SRAM is portable compared to DRAM, and SRAM doesn’t require any refresh current. On the basis of acquired knowledge, we present different SRAM's designed for the conventional CNTFET. HSPICE simulations of this circuit using Stanford CNTFET model shows a great improvement in power saving.

  20. Design and Modelling of Different SRAM'S Based on CNTFET 32NM Technology

    Directory of Open Access Journals (Sweden)

    Naagesh. S. Bhat

    2012-03-01

    Full Text Available Carbon nanotube field-effect transistor (CNTFET refers to a field-effect transistor that utilizes a single carbon nanotube or an array of carbon nanotubes as the channel material instead of bulk silicon in thetraditional MOSFET structure. Since it was first demonstrated in 1998, there have been tremendous developments in CNTFETs, which promise for an alternative material to replace silicon in future electronics. Carbon nanotubes are promising materials for the nano-scale electron devices such as nanotube FETs for ultra-high density integrated circuits and quantum-effect devices for novel intelligent circuits, which are expected to bring a breakthrough in the present silicon technology. A Static Random Access Memory (SRAM is designed to plug two needs: i The SRAM provides as cache memory, communicating between central processing unit and Dynamic Random Access Memory (DRAM. ii The SRAM technology act as driving force for low power application since SRAM is portable comparedto DRAM, and SRAM doesn’t require any refresh current. On the basis of acquired knowledge, we present different SRAM's designed for the conventional CNTFET. HSPICE simulations of this circuit using Stanford CNTFET model shows a great improvement in power saving.

  1. Do Different Young Plantation-Grown Species Require Different Biomass Models?

    Science.gov (United States)

    Bryce E. Schlaegel; Harvey E. Kennedy

    1985-01-01

    Sweetgum and water oak trees sampled from a plantation over 7 years were used to test whether primary tree component (bole wood, bole bark, limb wood, limb bark, and leaves) predictions could be summed to estimate total bole, total limb, and total tree values. Estimations by summing primary component predictions were not significantly different from predictions for the...

  2. INVESTIGATION OF DIFFERENT MODELS OF COMBINED PARALLEL FLASH BINARY CYCLES

    OpenAIRE

    A. Jafar Yazdi*

    2017-01-01

    The aim of this paper is a comparative study of the different geothermal power plant concepts, based on the energy and exergy analysis. The cycles studied in this paper are the combination of single and double flash power plants with two different ORC cycles as basic Organic Rankine Cycle (ORC), ORC with IHE, regenerative ORC and regenerative ORC with an IHE. The main gain due to using combined flash-binary power plants with various types of ORCs is to achieve optimum and efficient energy uti...

  3. Great Red Spot (GRS)

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    A huge permanent anticyclone in Jupiter's southern hemisphere, visible as a reddish oval at just over 20 °S. The earliest unequivocal observation was by Heinrich Schwabe in 1831 (the often-quoted sighting by Robert Hooke in 1664 now seems to have been of a similar but different spot). The GRS became a striking feature around 1880, when it developed a deep red coloration. It was also prominent in ...

  4. Socio-economic models of divorces in different societies

    CERN Document Server

    Jarynowski, Andrzej

    2012-01-01

    Population dynamic of getting divorced depends on many global factors, including social norms, economy, law or demographics as well as individual factors like the level of interpersonal or problem-solving skills of the spouses. We sought to find such a relationship incorporating only quantitative variables and test theoretical model considering phase transition between coupling (pairs) and free (single) preferential states as a function of social and economic. The analyzed data has been collected by UN across almost all the countries since 1948. Our first approach is followed by Bouchaud's model of social network of opinions, which works well with dynamics of fertility rates in postwar Europe. Unfortunately, we postulate that this pure sociological and pure economic approach fail in general. Thus, we did some observation about why it went wrong and where economy (e. g. Poland) or law (e. g. Portugal) has bigger impact on getting divorce than social pressure.

  5. Modelling the supernova-driven ISM in different environments

    CERN Document Server

    Gatto, A; Mac Low, M -M; Naab, T; Girichidis, P; Glover, S C O; Wünsch, R; Klessen, R S; Clark, P C; Baczynski, C; Peters, T; Ostriker, J P; Ibáñez-Mejía, J C; Haid, S

    2014-01-01

    We use hydrodynamical simulations in a $(256\\;{\\rm pc})^3$ periodic box to model the impact of supernova (SN) explosions on the multi-phase interstellar medium (ISM) for initial densities $n =$ 0.5-30 cm$^{-3}$ and SN rates 1-720 Myr$^{-1}$. We include radiative cooling, diffuse heating, and the formation of molecular gas using a chemical network. The SNe explode either at random positions, at density peaks, or both. We further present a model combining thermal energy for resolved and momentum input for unresolved SN remnants. Random driving at high SN rates results in hot gas ($T\\gtrsim 10^6$ K) filling $> 90$% of the volume. This gas reaches high pressures ($10^4 50$%), residing in small, dense clumps. Such a model might resemble the dense ISM in high-redshift galaxies. Peak driving results in huge radiative losses, but disrupts the densest regions by construction, producing a filamentary ISM with virtually no hot gas, and a small molecular hydrogen mass fraction ($\\ll 1$%). Varying the ratio of peak to ran...

  6. Investigating Differences between Modeled Historical and Station Calculated Drought

    Science.gov (United States)

    With growing concern over increased frequency and intensity of extreme climate events, there is an imperative need to investigate drought under different future scenarios for the contiguous U.S. To assess future drought relative to a historical baseline, drought occurrence (numbe...

  7. Holland's RIASEC Model as an Integrative Framework for Individual Differences

    Science.gov (United States)

    Armstrong, Patrick Ian; Day, Susan X.; McVay, Jason P.; Rounds, James

    2008-01-01

    Using data from published sources, the authors investigated J. L. Holland's (1959, 1997) theory of interest types as an integrative framework for organizing individual differences variables that are used in counseling psychology. Holland's interest types were used to specify 2- and 3-dimensional interest structures. In Study 1, measures of…

  8. Holland's RIASEC Model as an Integrative Framework for Individual Differences

    Science.gov (United States)

    Armstrong, Patrick Ian; Day, Susan X.; McVay, Jason P.; Rounds, James

    2008-01-01

    Using data from published sources, the authors investigated J. L. Holland's (1959, 1997) theory of interest types as an integrative framework for organizing individual differences variables that are used in counseling psychology. Holland's interest types were used to specify 2- and 3-dimensional interest structures. In Study 1, measures of…

  9. Efficiency Of Different Teaching Models In Teaching Of Frisbee Ultimate

    Directory of Open Access Journals (Sweden)

    Žuffová Zuzana

    2015-05-01

    Full Text Available The aim of the study was to verify the efficiency of two frisbee ultimate teaching models at 8-year grammar schools relative to age. In the experimental group was used a game based model (Teaching Games for Understanding and in the control group the traditional model based on teaching techniques. 6 groups of female students took part in experiment: experimental group 1 (n=10, age=11.6, experimental group 2 (n=12, age=13.8, experimental group 3 (n=14, age =15.8, control group 1 (n=11, age =11.7, control group 2 (n=10, age =13.8 and control group 3 (n=9, age =15.8. Efficiency of the teaching models was evaluated based of game performance and special knowledge results. Game performance was evaluated by the method of game performance assessment based on GPAI (Game Performance Assessment Instrument through video record. To verify level of knowledge, we used a knowledge test, which consisted of questions related to the rules and tactics knowledge of frisbee ultimate. To perform statistical evaluation Mann-Whitney U-test was used. Game performance assessment and knowledge level indicated higher efficiency of TGfU in general, but mostly statistically insignificant. Experimental groups 1 and 2 were significantly better in the indicator that evaluates tactical aspect of game performance - decision making (p<0.05. Experimental group 3 was better in the indicator that evaluates skill execution - disc catching. The results showed that the students of the classes taught by game based model reached partially better game performance in general. Experimental groups achieved from 79.17 % to 80 % of correct answers relating to the rules and from 75 % to 87.5 % of correct answers relating to the tactical knowledge in the knowledge test. Control groups achieved from 57.69 % to 72.22 % of correct answers relating to the rules and from 51.92 % to 72.22 % of correct answers relating to the tactical knowledge in the knowledge test.

  10. Comparative isotope ecology of African great apes.

    Science.gov (United States)

    Oelze, Vicky M; Fahy, Geraldine; Hohmann, Gottfried; Robbins, Martha M; Leinert, Vera; Lee, Kevin; Eshuis, Henk; Seiler, Nicole; Wessling, Erin G; Head, Josephine; Boesch, Christophe; Kühl, Hjalmar S

    2016-12-01

    The isotope ecology of great apes is a useful reference for palaeodietary reconstructions in fossil hominins. As extant apes live in C3-dominated habitats, variation in isotope signatures is assumed to be low compared to hominoids exploiting C4-plant resources. However, isotopic differences between sites and between and within individuals are poorly understood due to the lack of vegetation baseline data. In this comparative study, we included all species of free-ranging African great apes (Pan troglodytes, Pan paniscus, Gorilla sp.). First, we explore differences in isotope baselines across different habitats and whether isotopic signatures in apes can be related to feeding niches (faunivory and folivory). Secondly, we illustrate how stable isotopic variations within African ape populations compare to other extant and extinct primates and discuss possible implications for dietary flexibility. Using 701 carbon and nitrogen isotope data points resulting from 148 sectioned hair samples and an additional collection of 189 fruit samples, we compare six different great ape sites. We investigate the relationship between vegetation baselines and climatic variables, and subsequently correct great ape isotope data to a standardized plant baseline from the respective sites. We obtained temporal isotopic profiles of individual animals by sectioning hair along its growth trajectory. Isotopic signatures of great apes differed between sites, mainly as vegetation isotope baselines were correlated with site-specific climatic conditions. We show that controlling for plant isotopic characteristics at a given site is essential for faunal data interpretation. While accounting for plant baseline effects, we found distinct isotopic profiles for each great ape population. Based on evidence from habituated groups and sympatric great ape species, these differences could possibly be related to faunivory and folivory. Dietary flexibility in apes varied, but temporal variation was overall

  11. Pursuing the method of multiple working hypotheses to understand differences in process-based snow models

    Science.gov (United States)

    Clark, Martyn; Essery, Richard

    2017-04-01

    When faced with the complex and interdisciplinary challenge of building process-based land models, different modelers make different decisions at different points in the model development process. These modeling decisions are generally based on several considerations, including fidelity (e.g., what approaches faithfully simulate observed processes), complexity (e.g., which processes should be represented explicitly), practicality (e.g., what is the computational cost of the model simulations; are there sufficient resources to implement the desired modeling concepts), and data availability (e.g., is there sufficient data to force and evaluate models). Consequently the research community, comprising modelers of diverse background, experience, and modeling philosophy, has amassed a wide range of models, which differ in almost every aspect of their conceptualization and implementation. Model comparison studies have been undertaken to explore model differences, but have not been able to meaningfully attribute inter-model differences in predictive ability to individual model components because there are often too many structural and implementation differences among the different models considered. As a consequence, model comparison studies to date have provided limited insight into the causes of differences in model behavior, and model development has often relied on the inspiration and experience of individual modelers rather than on a systematic analysis of model shortcomings. This presentation will summarize the use of "multiple-hypothesis" modeling frameworks to understand differences in process-based snow models. Multiple-hypothesis frameworks define a master modeling template, and include a a wide variety of process parameterizations and spatial configurations that are used in existing models. Such frameworks provide the capability to decompose complex models into the individual decisions that are made as part of model development, and evaluate each decision in

  12. Complete electrode model in EEG: relationship and differences to the point electrode model

    Science.gov (United States)

    Pursiainen, S.; Lucka, F.; Wolters, C. H.

    2012-02-01

    In electroencephalography (EEG) source analysis, a primary current density generated by the neural activity of the brain is reconstructed from external electrode voltage measurements. This paper focuses on accurate and effective simulations of EEG through the complete electrode model (CEM). The CEM allows for the incorporation of the electrode size, shape and effective contact impedance into the forward simulation. Both neural currents in the brain and shunting currents between the electrodes and the skin can affect the measured voltages in the CEM. The goal of this study was to investigate the CEM by comparing it with the point electrode model (PEM), which is the current standard electrode model for EEG. We used a three-dimensional, realistic and high-resolution finite element head model as the reference computational domain in the comparison. The PEM could be formulated as a limit of the CEM, in which the effective impedance of each electrode goes to infinity and the size tends to zero. Numerical results concerning the forward and inverse errors and electrode voltage strengths with different impedances and electrode sizes are presented. Based on the results obtained, limits for extremely high and low impedance values of the shunting currents are suggested.

  13. Style Congruency and Persuasion: A Cross-Cultural Study Into the Influence of Differences in Style Dimensions on the Persuasiveness of Business Newsletters in Great Britain and the Netherlands

    NARCIS (Netherlands)

    Hendriks, B.C.; Meurs, W.F.J. van; Korzilius, H.P.L.M.; Pair, R.G. le; Blanc-Damen, S. le

    2012-01-01

    Abstract—Research problem: The purpose of the present study was to investigate whether style congruency on the dimensions succinct-elaborate and instrumental-affective influenced the persuasiveness of business newsletters in the Netherlands and Great Britain. Research question: Is a writing style mo

  14. Designs that make a difference: the Cardiac Universal Bed model.

    Science.gov (United States)

    Johnson, Jackie; Brown, Katherine Kay; Neal, Kelly

    2003-01-01

    Information contained in this article includes some of the findings from a joint research project conducted by Corazon Consulting and Ohio State University Medical Center on national trends in Cardiac Universal Bed (CUB) utilization. This article outlines current findings and "best practice" standards related to the benefits of developing care delivery models to differentiate an organization with a competitive advantage in the highly dynamic marketplace of cardiovascular care. (OSUMC, a Corazon client, is incorporating the CUB into their Ross Heart Hospital slated to open this spring.)

  15. [The Great Ape Project--human rights for the great anthropoid apes].

    Science.gov (United States)

    Scharmann, W

    2000-01-01

    The Great Ape Project (GAP) is an appeal of 36 scientist from different disciplines aiming at the legal equalisation of the non-human great apes (chimpanzees, gorillas and orang-utans) with man. The appeal is expressed by a number of essays stating zoological, genetical, ethological, anthropological, ethical and psychological knowledge and, based on these arguments, demanding the abolition of the species barrier between human beings and great apes. The central point of the initiative is the "Declaration on Great Apes", claiming the inclusion of great apes in the "community of equals" and thus securing three basic rights for all great apes: 1. The Right of Life; 2. The Protection of Individual Liberty; 3. The Prohibition of Torture. Not only experiments with great apes and their capture from the wilderness will be banned, but it is also intended to enfranchise as many great apes as possible from research laboratories and zoos. As a legal basis for the achievement of basic rights most of the authors plead for the idea of conferring the moral status of "persons" on great apes. Criticism of the GAP is due to its anthropocentrism. Rejection is especially expressed by advocates of pathocentric ethics who argue that the species barrier will not be abolished but only shifted, running then between the great apes and the remaining living beings. However, the GAP resulted in a greater retention in the use of great apes for experiments in several industrial countries. Additionally, the popular literature published by ethologists in the passed decades has supported a more responsible attitude of the public towards primates. Despite of all efforts the survival of the great apes is greatly endangered within their native countries.

  16. Improving Junior High Schools' Critical Thinking Skills Based on Test Three Different Models of Learning

    Science.gov (United States)

    Fuad, Nur Miftahul; Zubaidah, Siti; Mahanal, Susriyati; Suarsini, Endang

    2017-01-01

    The aims of this study were (1) to find out the differences in critical thinking skills among students who were given three different learning models: differentiated science inquiry combined with mind map, differentiated science inquiry model, and conventional model, (2) to find out the differences of critical thinking skills among male and female…

  17. Investigating the mechanics of multimedia box models: how to explain differences between models in terms of mass fluxes?

    Science.gov (United States)

    Scheringer, Martin; Wegmann, Fabio; Hungerbühler, Konrad

    2004-10-01

    The simple mathematical structure of multimedia fate models makes it possible to change the process descriptions and geometry of such models relatively easily. With different versions of a model, the effect of a process or compartment that is included in one version of the model but excluded in another version can be investigated. Here, a new method for performing such a model comparison in a quantitative way is presented. Based on the mass balances for the two model versions, it can be shown that, for a compartment contained in both model versions, the difference between a chemical's concentrations in this compartment is related directly to the difference in those mass fluxes that have different rate constants in the two models. Moreover, it is possible to identify the contributions to the concentration difference that stem from individual mass fluxes so that the concentration difference can be tracked back to specific differences in the process descriptions of the two models. This flux analysis method is illustrated with two versions of a unit-world model, one with and one without a vegetation compartment. With DDT and six polychlorinated biphenyl (PCB) congeners as example chemicals, the differences of the chemicals' concentrations in air and soil caused by the vegetation compartment are explained by using the flux analysis method. The future potential of the method for comparing not only versions of the same model but also models of different structure is discussed.

  18. Data assimilation of a ten-day period during June 1993 over the Southern Great Plains Site using a nested mesoscale model

    Energy Technology Data Exchange (ETDEWEB)

    Dudhia, J.; Guo, Y.R. [National Center for Atmospheric Research, Boulder, CO (United States)

    1996-04-01

    A goal of the Atmospheric Radiation Measurement (ARM) Program has been to obtain a complete representation of physical processes on the scale of a general circulation model (GCM) grid box in order to better parameterize radiative processes in these models. Since an observational network of practical size cannot be used alone to characterize the Cloud and Radiation Testbed (CART) site`s 3D structure and time development, data assimilation using the enhanced observations together with a mesoscale model is used to give a full 4D analysis at high resolution. The National Center for Atmospheric Research (NCAR)/Penn State Mesoscale Model (MM5) has been applied over a ten-day continuous period in a triple-nested mode with grid sizes of 60, 20 and 6.67 in. The outer domain covers the United States` 48 contiguous states; the innermost is a 480-km square centered on Lamont, Oklahoma. A simulation has been run with data assimilation using the Mesoscale Analysis and Prediction System (MAPS) 60-km analyses from the Forecast Systems Laboratory (FSL) of the National Ocean and Atmospheric Administration (NOAA). The nested domains take boundary conditions from and feed back continually to their parent meshes (i.e., they are two-way interactive). As reported last year, this provided a simulation of the basic features of mesoscale events over the CART site during the period 16-26 June 1993 when an Intensive Observation Period (IOP) was under way.

  19. Phospholipid dynamics in graphene of different topologies: predictive modeling

    Science.gov (United States)

    Glukhova, O. E.; Slepchenkov, M. M.

    2017-02-01

    The subject of our scientific interest is the dynamics of the phospholipid molecules into a corrugated graphene sheet. According to our assumption by changing the topology of graphene properly it is possible to find the ways for management of the selective localization of phospholipid molecules to form the desired configuration of these structures. We considered DPPC (dipalmitoylphosphatidylcholine) phospholipids, which are the part of cell membranes and lipoproteins. We investigated the behavior of the phospholipids on the graphene sheet consisting of 1710 atoms with the size of 6.9 nm along the zigzag edge and 6.25 nm along the armchair edge. The numerical experiment was carried out using the original AMBER/AIREBO hybrid method with Lennard-Jones potential to describe the interaction between unbound atoms of different structures. The temperature was maintained at 300 K during the numerical experiment. All numerical experiments were performed using KVAZAR software system. We considered several cases of corrugated graphene with different width and dept of the corrugation. Special attention in our work was paid to the orientation of the phospholipids in the plane of graphene sheet.

  20. Evaluating stream health based environmental justice model performance at different spatial scales

    Science.gov (United States)

    Daneshvar, Fariborz; Nejadhashemi, A. Pouyan; Zhang, Zhen; Herman, Matthew R.; Shortridge, Ashton; Marquart-Pyatt, Sandra

    2016-07-01

    This study evaluated the effects of spatial resolution on environmental justice analysis concerning stream health. The Saginaw River Basin in Michigan was selected since it is an area of concern in the Great Lakes basin. Three Bayesian Conditional Autoregressive (CAR) models (ordinary regression, weighted regression and spatial) were developed for each stream health measure based on 17 socioeconomic and physiographical variables at three census levels. For all stream health measures, spatial models had better performance compared to the two non-spatial ones at the census tract and block group levels. Meanwhile no spatial dependency was found at the county level. Multilevel Bayesian CAR models were also developed to understand the spatial dependency at the three levels. Results showed that considering level interactions improved models' prediction. Residual plots also showed that models developed at the block group and census tract (in contrary to county level models) are able to capture spatial variations.

  1. Hydrologic models of modern and fossil geothermal systems in the Great Basin: Genetic implications for epithermal Au-Ag and Carlin-type gold deposits

    Science.gov (United States)

    Person, M.; Banerjee, A.; Hofstra, A.; Sweetkind, D.; Gao, Y.

    2008-01-01

    The Great Basin region in the western United States contains active geothermal systems, large epithermal Au-Ag deposits, and world-class Carlin-type gold deposits. Temperature profiles, fluid inclusion studies, and isotopic evidence suggest that modern and fossil hydrothermal systems associated with gold mineralization share many common features, including the absence of a clear magmatic fluid source, discharge areas restricted to fault zones, and remarkably high temperatures (>200 ??C) at shallow depths (200-1500 m). While the plumbing of these systems varies, geochemical and isotopic data collected at the Dixie Valley and Beowawe geothermal systems suggest that fluid circulation along fault zones was relatively deep (>5 km) and comprised of relatively unexchanged Pleistocene meteoric water with small (enthalpy, ??18O, silica compositions of fluids and/or rocks, groundwater residence times, fluid inclusion homogenization temperatures, and apatite fission track anomalies. Our results suggest that these hydrothermal systems were driven by natural thermal convection along anisotropic, subvertical faults connected in many cases at depth by permeable aquifers within favorable lithostratigraphic horizons. Those with minimal fluid ?? 18O shifts are restricted to high-permeability fault zones and relatively small-scale (???5 km), single-pass flow systems (e.g., Beowawe). Those with intermediate to large isotopic shifts (e.g., epithermal and Carlin-type Au) had larger-scale (???15 km) loop convection cells with a greater component of flow through marine sedimentary rocks at lower water/rock ratios and greater endowments of gold. Enthalpy calculations constrain the duration of Carlin-type gold systems to probably concentrations suggest that the duration of the modern Beowawe system is enthalpy fluids. Computed fission track ages along the Carlin trend included the convective effects, and ranged between 91.6 and 35.3 Ma. Older fission track ages occurred in zones of

  2. Using time-varying global sensitivity analysis to understand the importance of different uncertainty sources in hydrological modelling

    Science.gov (United States)

    Pianosi, Francesca; Wagener, Thorsten

    2016-04-01

    Simulations from environmental models are affected by potentially large uncertainties stemming from various sources, including model parameters and observational uncertainty in the input/output data. Understanding the relative importance of such sources of uncertainty is essential to support model calibration, validation and diagnostic evaluation, and to prioritize efforts for uncertainty reduction. Global Sensitivity Analysis (GSA) provides the theoretical framework and the numerical tools to gain this understanding. However, in traditional applications of GSA, model outputs are an aggregation of the full set of simulated variables. This aggregation of propagated uncertainties prior to GSA may lead to a significant loss of information and may cover up local behaviour that could be of great interest. In this work, we propose a time-varying version of a recently developed density-based GSA method, called PAWN, as a viable option to reduce this loss of information. We apply our approach to a medium-complexity hydrological model in order to address two questions: [1] Can we distinguish between the relative importance of parameter uncertainty versus data uncertainty in time? [2] Do these influences change in catchments with different characteristics? The results present the first quantitative investigation on the relative importance of parameter and data uncertainty across time. They also provide a demonstration of the value of time-varying GSA to investigate the propagation of uncertainty through numerical models and therefore guide additional data collection needs and model calibration/assessment.

  3. Pacific salmonines in the Great Lakes Basin

    Science.gov (United States)

    Claramunt, Randall M.; Madenjian, Charles P.; Clapp, David; Taylor, William W.; Lynch, Abigail J.; Leonard, Nancy J.

    2012-01-01

    Pacific salmon (genus Oncorhynchus) are a valuable resource, both within their native range in the North Pacific rim and in the Great Lakes basin. Understanding their value from a biological and economic perspective in the Great Lakes, however, requires an understanding of changes in the ecosystem and of management actions that have been taken to promote system stability, integrity, and sustainable fisheries. Pacific salmonine introductions to the Great Lakes are comprised mainly of Chinook salmon, coho salmon, and steelhead and have accounted for 421, 177, and 247 million fish, respectively, stocked during 1966-2007. Stocking of Pacific salmonines has been effective in substantially reducing exotic prey fish abundances in several of the Great Lakes (e.g., lakes Michigan, Huron, and Ontario). The goal of our evaluation was to highlight differences in management strategies and perspectives across the basin, and to evaluate policies for Pacific salmonine management in the Great Lakes. Currently, a potential conflict exists between Pacific salmonine management and native fish rehabilitation goals because of the desire to sustain recreational fisheries and to develop self-sustaining populations of stocked Pacific salmonines in the Great Lakes. We provide evidence that suggests Pacific salmonines have not only become naturalized to the food webs of the Great Lakes, but that their populations (specifically Chinook salmon) may be fluctuating in concert with specific prey (i.e., alewives) whose populations are changing relative to environmental conditions and ecosystem disturbances. Remaining questions, however, are whether or not “natural” fluctuations in predator and prey provide enough “stability” in the Great Lakes food webs, and even more importantly, would a choice by managers to attempt to reduce the severity of predator-prey oscillations be antagonistic to native fish restoration efforts. We argue that, on each of the Great Lakes, managers are pursuing

  4. Developing Students’ Reflections about the Function and Status of Mathematical Modeling in Different Scientific Practices

    DEFF Research Database (Denmark)

    Kjeldsen, Tinne Hoff; Blomhøj, Morten

    2013-01-01

    Mathematical models and mathematical modeling play different roles in the different areas and problems in which they are used. The function and status of mathematical modeling and models in the different areas depend on the scientific practice as well as the underlying philosophical and theoretical...... position held by the modeler(s) and the practitioners in the extra-mathematical domain. For students to experience the significance of different scientific practices and cultures for the function and status of mathematical modeling in other sciences, students need to be placed in didactical situations...... in situations in which they can experience and be challenged to reflect upon and criticize, the use of modeling and the significance of the context for the function and status of modeling and models in scientific practices. We present Nicolas Rashevsky’s model of cell division from the 1930s together...

  5. The Great Cometary Show

    Science.gov (United States)

    2007-01-01

    its high spatial and spectral resolution, it was possible to zoom into the very heart of this very massive star. In this innermost region, the observations are dominated by the extremely dense stellar wind that totally obscures the underlying central star. The AMBER observations show that this dense stellar wind is not spherically symmetric, but exhibits a clearly elongated structure. Overall, the AMBER observations confirm that the extremely high mass loss of Eta Carinae's massive central star is non-spherical and much stronger along the poles than in the equatorial plane. This is in agreement with theoretical models that predict such an enhanced polar mass-loss in the case of rapidly rotating stars. ESO PR Photo 06c/07 ESO PR Photo 06c/07 RS Ophiuchi in Outburst Several papers from this special feature focus on the later stages in a star's life. One looks at the binary system Gamma 2 Velorum, which contains the closest example of a star known as a Wolf-Rayet. A single AMBER observation allowed the astronomers to separate the spectra of the two components, offering new insights in the modeling of Wolf-Rayet stars, but made it also possible to measure the separation between the two stars. This led to a new determination of the distance of the system, showing that previous estimates were incorrect. The observations also revealed information on the region where the winds from the two stars collide. The famous binary system RS Ophiuchi, an example of a recurrent nova, was observed just 5 days after it was discovered to be in outburst on 12 February 2006, an event that has been expected for 21 years. AMBER was able to detect the extension of the expanding nova emission. These observations show a complex geometry and kinematics, far from the simple interpretation of a spherical fireball in extension. AMBER has detected a high velocity jet probably perpendicular to the orbital plane of the binary system, and allowed a precise and careful study of the wind and the shockwave

  6. Kansas environmental and resource study: A Great Plains model. Extraction of agricultural statistics from ERTS-1 data of Kansas. [wheat inventory and agriculture land use

    Science.gov (United States)

    Morain, S. A. (Principal Investigator); Williams, D. L.

    1974-01-01

    The author has identified the following significant results. Wheat area, yield, and production statistics as derived from satellite image analysis, combined with a weather model, are presented for a ten county area in southwest Kansas. The data (representing the 1972-73 crop year) are compared for accuracy against both the USDA August estimate and its final (official) tabulation. The area estimates from imagery for both dryland and irrigated winter wheat were within 5% of the official figures for the same area, and predated them by almost one year. Yield on dryland wheat was estimated by the Thompson weather model to within 0.1% of the observed yield. A combined irrigated and dryland wheat production estimate for the ten county area was completed in July, 1973 and was within 1% of the production reported by USDA in February, 1974.

  7. Different models of gravitating Dirac fermions in optical lattices

    Science.gov (United States)

    Celi, Alessio

    2017-07-01

    In this paper I construct the naive lattice Dirac Hamiltonian describing the propagation of fermions in a generic 2D optical metric for different lattice and flux-lattice geometries. First, I apply a top-down constructive approach that we first proposed in [Boada et al., New J. Phys. 13, 035002 (2011)] to the honeycomb and to the brickwall lattices. I carefully discuss how gauge transformations that generalize momentum (and Dirac cone) shifts in the Brillouin zone in the Minkowski homogeneous case can be used in order to change the phases of the hopping. In particular, I show that lattice Dirac Hamiltonian for Rindler spacetime in the honeycomb and brickwall lattices can be realized by considering real and isotropic (but properly position dependent) tunneling terms. For completeness, I also discuss a suitable formulation of Rindler Dirac Hamiltonian in semi-synthetic brickwall and π-flux square lattices (where one of the dimension is implemented by using internal spin states of atoms as we originally proposed in [Boada et al., Phys. Rev. Lett. 108, 133001 (2012)] and [Celi et al., Phys. Rev. Lett. 112, 043001 (2014)]).

  8. SOMO (SOlution MOdeler) differences between X-Ray- and NMR-derived bead models suggest a role for side chain flexibility in protein hydrodynamics.

    Science.gov (United States)

    Rai, Nithin; Nöllmann, Marcelo; Spotorno, Bruno; Tassara, Giovanni; Byron, Olwyn; Rocco, Mattia

    2005-05-01

    Reduced numbers of frictional/scattering centers are essential for tractable hydrodynamic and small-angle scattering data modeling. We present a method for generating medium-resolution models from the atomic coordinates of proteins, basically by using two nonoverlapping spheres of differing radii per residue. The computed rigid-body hydrodynamic parameters of BPTI, RNase A, and lysozyme models were compared with a large database of critically assessed experimental values. Overall, very good results were obtained, but significant discrepancies between X-ray- and NMR-derived models were found. Interestingly, they could be accounted for by properly considering the extent to which highly mobile surface side chains differently affect translational/rotational properties. Models of larger structures, such as fibrinogen fragment D and citrate synthase, also produced consistent results. Foremost among this method's potential applications is the overall conformation and dynamics of modular/multidomain proteins and of supramolecular complexes. The possibility of merging data from high- and low-resolution structures greatly expands its scope.

  9. Application of the FluEgg model to predict transport of Asian carp eggs in the Saint Joseph River (Great Lakes tributary)

    Science.gov (United States)

    Garcia, Tatiana; Murphy, Elizabeth A.; Jackson, P. Ryan; Garcia, Marcelo H.

    2015-01-01

    The Fluvial Egg Drift Simulator (FluEgg) is a three-dimensional Lagrangian model that simulates the movement and development of Asian carp eggs until hatching based on the physical characteristics of the flow field and the physical and biological characteristics of the eggs. This tool provides information concerning egg development and spawning habitat suitability including: egg plume location, egg vertical and travel time distribution, and egg-hatching risk. A case study of the simulation of Asian carp eggs in the Lower Saint Joseph River, a tributary of Lake Michigan, is presented. The river hydrodynamic input for FluEgg was generated in two ways — using hydroacoustic data and using HEC-RAS model data. The HEC-RAS model hydrodynamic input data were used to simulate 52 scenarios covering a broad range of flows and water temperatures with the eggs at risk of hatching ranging from 0 to 93% depending on river conditions. FluEgg simulations depict the highest percentage of eggs at risk of hatching occurs at the lowest discharge and at peak water temperatures. Analysis of these scenarios illustrates how the interactive relation among river length, hydrodynamics, and water temperature influence egg transport and hatching risk. An improved version of FluEgg, which more realistically simulates dispersion and egg development, is presented. Also presented is a graphical user interface that facilitates the use of FluEgg and provides a set of post-processing analysis tools to support management decision-making regarding the prevention and control of Asian carp reproduction in rivers with or without Asian carp populations.

  10. Comparative study analysing women's childbirth satisfaction and obstetric outcomes across two different models of maternity care

    OpenAIRE

    Conesa Ferrer, Ma Belén; Canteras Jordana, Manuel; Ballesteros Meseguer, Carmen; Carrillo García, César; Martínez Roche, M Emilia

    2016-01-01

    Objectives To describe the differences in obstetrical results and women's childbirth satisfaction across 2 different models of maternity care (biomedical model and humanised birth). Setting 2 university hospitals in south-eastern Spain from April to October 2013. Design A correlational descriptive study. Participants A convenience sample of 406 women participated in the study, 204 of the biomedical model and 202 of the humanised model. Results The differences in obstetrical results were (biom...

  11. Will Coral Islands maintain their growth over the next century? A deterministic model of sediment availability at Lady Elliot Island, Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Sarah Hamylton

    Full Text Available A geomorphic assessment of reef system calcification is conducted for past (3200 Ka to present, present and future (2010-2100 time periods. Reef platform sediment production is estimated at 569 m3 yr-1 using rate laws that express gross community carbonate production as a function of seawater aragonite saturation, community composition and rugosity and incorporating estimates of carbonate removal from the reef system. Key carbonate producers including hard coral, crustose coralline algae and Halimeda are mapped accurately (mean R2 = 0.81. Community net production estimates correspond closely to independent census-based estimates made in-situ (R2 = 0.86. Reef-scale outputs are compared with historic rates of production generated from (i radiocarbon evidence of island deposition initiation around 3200 years ago, and (ii island volume calculated from a high resolution island digital elevation model. Contemporary carbonate production rates appear to be remarkably similar to historical values of 573 m3 yr-1. Anticipated future seawater chemistry parameters associated with an RCP8.5 emissions scenario are employed to model rates of net community calcification for the period 2000-2100 on the basis of an inorganic aragonite precipitation law, under the assumption of constant benthic community character. Simulations indicate that carbonate production will decrease linearly to a level of 118 m3 yr-1 by 2100 and that by 2150 aragonite saturation levels may no longer support the positive budgetary status necessary to sustain island accretion. Novel aspects of this assessment include the development of rate law parameters to realistically represent the variable composition of coral reef benthic carbonate producers, incorporation of three dimensional rugosity of the entire reef platform and the coupling of model outputs with both historical radiocarbon dating evidence and forward hydrochemical projections to conduct an assessment of island evolution

  12. Will Coral Islands maintain their growth over the next century? A deterministic model of sediment availability at Lady Elliot Island, Great Barrier Reef.

    Science.gov (United States)

    Hamylton, Sarah

    2014-01-01

    A geomorphic assessment of reef system calcification is conducted for past (3200 Ka to present), present and future (2010-2100) time periods. Reef platform sediment production is estimated at 569 m3 yr-1 using rate laws that express gross community carbonate production as a function of seawater aragonite saturation, community composition and rugosity and incorporating estimates of carbonate removal from the reef system. Key carbonate producers including hard coral, crustose coralline algae and Halimeda are mapped accurately (mean R2 = 0.81). Community net production estimates correspond closely to independent census-based estimates made in-situ (R2 = 0.86). Reef-scale outputs are compared with historic rates of production generated from (i) radiocarbon evidence of island deposition initiation around 3200 years ago, and (ii) island volume calculated from a high resolution island digital elevation model. Contemporary carbonate production rates appear to be remarkably similar to historical values of 573 m3 yr-1. Anticipated future seawater chemistry parameters associated with an RCP8.5 emissions scenario are employed to model rates of net community calcification for the period 2000-2100 on the basis of an inorganic aragonite precipitation law, under the assumption of constant benthic community character. Simulations indicate that carbonate production will decrease linearly to a level of 118 m3 yr-1 by 2100 and that by 2150 aragonite saturation levels may no longer support the positive budgetary status necessary to sustain island accretion. Novel aspects of this assessment include the development of rate law parameters to realistically represent the variable composition of coral reef benthic carbonate producers, incorporation of three dimensional rugosity of the entire reef platform and the coupling of model outputs with both historical radiocarbon dating evidence and forward hydrochemical projections to conduct an assessment of island evolution through time

  13. How users experience great products

    NARCIS (Netherlands)

    Ortiz Nicolas, J.C.; Aurisicchio, M.; Desmet, P.M.A.

    2013-01-01

    This study reports qualitative research about how users experience great products. Eighteen interviews were conducted in which participants were asked to bring along a ‘great’ product that they own. During the interviews participants explained why they consider a product great and how they experienc

  14. Great Explorers to the East.

    Science.gov (United States)

    Baker, Rosalie F., Ed.; Baker, Charles F. III, Ed.

    1990-01-01

    This issue of "Calliope," a world history magazine for young people is devoted to "Great Explorers of the East" and features articles on famous explorers of the eastern hemisphere. The following articles are included: "Ancient Egyptian Mariners"; "Alexander: The Great Reconciler"; "Marco Polo:…

  15. What Caused the Great Depression?

    Science.gov (United States)

    Caldwell, Jean; O'Driscoll, Timothy G.

    2007-01-01

    Economists and historians have struggled for almost 80 years to account for the American Great Depression, which began in 1929 and lasted until the early years of World War II. In this article, the authors discuss three major schools of thought on the causes of the Great Depression and the long failure of the American economy to return to full…

  16. Great Explorers to the East.

    Science.gov (United States)

    Baker, Rosalie F., Ed.; Baker, Charles F. III, Ed.

    1990-01-01

    This issue of "Calliope," a world history magazine for young people is devoted to "Great Explorers of the East" and features articles on famous explorers of the eastern hemisphere. The following articles are included: "Ancient Egyptian Mariners"; "Alexander: The Great Reconciler"; "Marco Polo: Describing the World"; "By Water to India";…

  17. Rethinking China's new great wall

    National Research Council Canada - National Science Library

    Ma, Zhijun; Melville, David S; Liu, Jianguo; Chen, Ying; Yang, Hongyan; Ren, Wenwei; Zhang, Zhengwang; Piersma, Theunis; Li, Bo

    2014-01-01

    ... enclosed by thousands of kilometers of seawalls, whose length exceeds that of China’s famous ancient “Great Wall” (see photos and map). This new “Great Wall,” covering 60% of the total length of coast-line along mainland China...

  18. Great Lakes rivermouths: a primer for managers

    Science.gov (United States)

    Pebbles, Victoria; Larson, James; Seelbach, Paul; Pebbles, Victoria; Larson, James; Seelbach, Paul

    2013-01-01

    Between the North American Great Lakes and their tributaries are the places where the confluence of river and lake waters creates a distinct ecosystem: the rivermouth ecosystem. Human development has often centered around these rivermouths, in part, because they provide a rich array of ecosystem services. Not surprisingly, centuries of intense human activity have led to substantial pressures on, and alterations to, these ecosystems, often diminishing or degrading their ecological functions and associated ecological services. Many Great Lakes rivermouths are the focus of intense restoration efforts. For example, 36 of the active Great Lakes Areas of Concern (AOCs) are rivermouths or areas that include one or more rivermouths. Historically, research of rivermouth ecosystems has been piecemeal, focused on the Great Lakes proper or on the upper reaches of tributaries, with little direct study of the rivermouth itself. Researchers have been divided among disciplines, agencies and institutions; and they often work independently and use disparate venues to communicate their work. Management has also been fragmented with a focus on smaller, localized, sub-habitat units and socio-political or economic elements, rather than system-level consideration. This Primer presents the case for a more holistic approach to rivermouth science and management that can enable restoration of ecosystem services with multiple benefits to humans and the Great Lakes ecosystem. A conceptual model is presented with supporting text that describes the structures and processes common to all rivermouths, substantiating the case for treating these ecosystems as an identifiable class.1 Ecological services provided by rivermouths and changes in how humans value those services over time are illustrated through case studies of two Great Lakes rivermouths—the St. Louis River and the Maumee River. Specific ecosystem services are identified in italics throughout this Primer and follow definitions described

  19. Comparing the Goodness of Different Statistical Criteria for Evaluating the Soil Water Infiltration Models

    Directory of Open Access Journals (Sweden)

    S. Mirzaee

    2016-02-01

    Full Text Available Introduction: The infiltration process is one of the most important components of the hydrologic cycle. Quantifying the infiltration water into soil is of great importance in watershed management. Prediction of flooding, erosion and pollutant transport all depends on the rate of runoff which is directly affected by the rate of infiltration. Quantification of infiltration water into soil is also necessary to determine the availability of water for crop growth and to estimate the amount of additional water needed for irrigation. Thus, an accurate model is required to estimate infiltration of water into soil. The ability of physical and empirical models in simulation of soil processes is commonly measured through comparisons of simulated and observed values. For these reasons, a large variety of indices have been proposed and used over the years in comparison of infiltration water into soil models. Among the proposed indices, some are absolute criteria such as the widely used root mean square error (RMSE, while others are relative criteria (i.e. normalized such as the Nash and Sutcliffe (1970 efficiency criterion (NSE. Selecting and using appropriate statistical criteria to evaluate and interpretation of the results for infiltration water into soil models is essential because each of the used criteria focus on specific types of errors. Also, descriptions of various goodness of fit indices or indicators including their advantages and shortcomings, and rigorous discussions on the suitability of each index are very important. The objective of this study is to compare the goodness of different statistical criteria to evaluate infiltration of water into soil models. Comparison techniques were considered to define the best models: coefficient of determination (R2, root mean square error (RMSE, efficiency criteria (NSEI and modified forms (such as NSEjI, NSESQRTI, NSElnI and NSEiI. Comparatively little work has been carried out on the meaning and

  20. Prediction of Pig Trade Movements in Different European Production Systems Using Exponential Random Graph Models.

    Science.gov (United States)

    Relun, Anne; Grosbois, Vladimir; Alexandrov, Tsviatko; Sánchez-Vizcaíno, Jose M; Waret-Szkuta, Agnes; Molia, Sophie; Etter, Eric Marcel Charles; Martínez-López, Beatriz

    2017-01-01

    In most European countries, data regarding movements of live animals are routinely collected and can greatly aid predictive epidemic modeling. However, the use of complete movements' dataset to conduct policy-relevant predictions has been so far limited by the massive amount of data that have to be processed (e.g., in intensive commercial systems) or the restricted availability of timely and updated records on animal movements (e.g., in areas where small-scale or extensive production is predominant). The aim of this study was to use exponential random graph models (ERGMs) to reproduce, understand, and predict pig trade networks in different European production systems. Three trade networks were built by aggregating movements of pig batches among premises (farms and trade operators) over 2011 in Bulgaria, Extremadura (Spain), and Côtes-d'Armor (France), where small-scale, extensive, and intensive pig production are predominant, respectively. Three ERGMs were fitted to each network with various demographic and geographic attributes of the nodes as well as six internal network configurations. Several statistical and graphical diagnostic methods were applied to assess the goodness of fit of the models. For all systems, both exogenous (attribute-based) and endogenous (network-based) processes appeared to govern the structure of pig trade network, and neither alone were capable of capturing all aspects of the network structure. Geographic mixing patterns strongly structured pig trade organization in the small-scale production system, whereas belonging to the same company or keeping pigs in the same housing system appeared to be key drivers of pig trade, in intensive and extensive production systems, respectively. Heterogeneous mixing between types of production also explained a part of network structure, whichever production system considered. Limited information is thus needed to capture most of the global structure of pig trade networks. Such findings will be useful

  1. Fluvial Transport Model from Spatial Distribution Analysis of Libyan Desert Glass Mass on the Great Sand Sea (Southwest Egypt: Clues to Primary Glass Distribution

    Directory of Open Access Journals (Sweden)

    Nancy Jimenez-Martinez

    2015-04-01

    Full Text Available Libyan Desert Glass (LDG is a natural silica-rich melted rock found as pieces scattered over the sand and bedrock of the Western Desert of Egypt, northeast of the Gilf Kebir. In this work, a population mixture analysis serves to relate the present spatial distribution of LDG mass density with the Late Oligocene–Early Miocene fluvial dynamics in the Western Desert of Egypt. This was verified from a spatial distribution model that was predicted from the log-normal kriging method using the LDG–mass-dependent transformed variable, Y(x. Both low- and high-density normal populations (–9.2 < Y(x < –3.5 and –3.8 < Y(x < 2.1, respectively were identified. The low-density population was the result of an ordinary fluvial LDG transport/deposition sequence that was active from the time of the melting process, and which lasted until the end of activity of the Gilf River. The surface distribution of the high-density population allowed us to restrict the source area of the melting process. We demonstrate the importance of this geostatistical study in unveiling the probable location of the point where the melting of surficial material occurred and the role of the Gilf River in the configuration of the observed strewn field.

  2. Kansas environmental and resource study: A Great Plains model. [land use, image enhancement, winter wheat, agriculture, water resources, and pattern recognition

    Science.gov (United States)

    Haralick, R. M.; Kanemasu, E. T.; Morain, S. A.; Yarger, H. L.; Ulaby, F. T.; Davis, J. C. (Principal Investigator); Bosley, R. J.; Williams, D. L.; Mccauley, J. R.; Mcnaughton, J. L.

    1973-01-01

    The author has identified the following significant results. Improvement in the land use classification accuracy of ERTS-1 MSS multi-images over Kansas can be made using two distances between neighboring grey tone N-tuples instead of one distance. Much more information is contained texturally than spectrally on the Kansas image. Ground truth measurements indicate that reflectance ratios of the 545 and 655 nm wavebands provide an index of plant development and possibly physiological stress. Preliminary analysis of MSS 4 and 5 channels substantiate the ground truth interpretation. Results of the land use mapping experiment indicate that ERTS-1 imagery has major potential in regionalization. The ways in which land is utilized within these regions may then be studied more effectively than if no adequate regionalization is available. A model for estimating wheat yield per acre has been applied to acreage estimates derived from ERTS-1 imagery to project the 1973 wheat yields for a ten county area in southwest Kansas. The results are within 3% of the preharvest estimates for the same area prepared by the USDA. Visual identification of winter wheat is readily achieved by using a temporal sequence of images. Identification can be improve by stratifying the project area into subregions having more or less homogeneous agricultural practices and crop mixes.

  3. Modelling of human low frequency sound localization acuity demonstrates dominance of spatial variation of interaural time difference and suggests uniform just-noticeable differences in interaural time difference.

    Directory of Open Access Journals (Sweden)

    Rosanna C G Smith

    Full Text Available Sound source localization is critical to animal survival and for identification of auditory objects. We investigated the acuity with which humans localize low frequency, pure tone sounds using timing differences between the ears. These small differences in time, known as interaural time differences or ITDs, are identified in a manner that allows localization acuity of around 1° at the midline. Acuity, a relative measure of localization ability, displays a non-linear variation as sound sources are positioned more laterally. All species studied localize sounds best at the midline and progressively worse as the sound is located out towards the side. To understand why sound localization displays this variation with azimuthal angle, we took a first-principles, systemic, analytical approach to model localization acuity. We calculated how ITDs vary with sound frequency, head size and sound source location for humans. This allowed us to model ITD variation for previously published experimental acuity data and determine the distribution of just-noticeable differences in ITD. Our results suggest that the best-fit model is one whereby just-noticeable differences in ITDs are identified with uniform or close to uniform sensitivity across the physiological range. We discuss how our results have several implications for neural ITD processing in different species as well as development of the auditory system.

  4. Pitfalls in urinary stone identification using CT attenuation values: Are we getting the same information on different scanner models?

    Energy Technology Data Exchange (ETDEWEB)

    Grosjean, Romain, E-mail: r.grosjean@chu-nancy.fr [IADI Laboratory, INSERM-U947, Nancy-University, Allée du Morvan, 54500 Vandoeuvre-les-Nancy (France); Daudon, Michel, E-mail: michel.daudon@tnn.aphp.fr [IADI Laboratory, INSERM-U947, Nancy-University, Allée du Morvan, 54500 Vandoeuvre-les-Nancy (France); Chammas, Mario F., E-mail: mariochammas@usp.br [University of Sao Paulo – Division of Urology, Av. Dr. Enéas de Carvalho Aguiar, 255, 7" o Andar – s. 7123, São Paulo (Brazil); Claudon, Michel, E-mail: m.claudon@chu-nancy.fr [IADI Laboratory, INSERM-U947, Nancy-University, Allée du Morvan, 54500 Vandoeuvre-les-Nancy (France); Eschwege, Pascal, E-mail: peschwege@yahoo.com [Department of Urology, Brabois Hospital, University Hospital of Nancy, Allée du Morvan, 54511 Vandoeuvre-les-Nancy (France); Felblinger, Jacques, E-mail: j.felblinger@chu-nancy.fr [IADI Laboratory, INSERM-U947, Nancy-University, Allée du Morvan, 54500 Vandoeuvre-les-Nancy (France); Hubert, Jacques, E-mail: j.hubert@chu-nancy.fr [Department of Urology, Brabois Hospital, University Hospital of Nancy, Allée du Morvan, 54511 Vandoeuvre-les-Nancy (France)

    2013-08-15

    Introduction: Evaluate the capability of different Computed Tomography scanners to determine urinary stone compositions based on CT attenuation values and to evaluate potential differences between each model. Methods: 241 human urinary stones were obtained and their biochemical composition determined. Four different CT scanners (Siemens, Philips, GEMS and Toshiba) were evaluated. Mean CT-attenuation values and the standard deviation were recorded separately and compared with a t-paired test. Results: For all tested CT scanners, when the classification of the various types of stones was arranged according to the mean CT-attenuation values and to the confidence interval, large overlappings between stone types were highlighted. The t-paired test showed that most stone types could not be identified. Some types of stones presented mean CT attenuation values significantly different from one CT scanner to another. At 80 kV, the mean CT attenuation values obtained with the Toshiba Aquilion were significantly different from those obtained with the Siemens Sensation. On the other hand, mean values obtained with the Philips Brilliance were all significantly equal to those obtained with the Siemens Sensation and with the Toshiba Aquilion. At 120 kV mean CT attenuation values of uric acid, cystine and struvite stones obtained with the Philips model are significantly different from those obtained with the Siemens and the Toshiba but equal to those obtained with the GE 64. Conclusions: According to our study, there is a great variability when different brands and models of scanners are compared directly. Furthermore, the CT scan analysis and HU evaluation appears to gather insufficient information in order to characterize and identify the composition of renal stones.

  5. Comparison of Different GPP Models in China Using MODIS Image and ChinaFLUX Data

    Directory of Open Access Journals (Sweden)

    Zhengjia Liu

    2014-10-01

    Full Text Available Accurate quantification of gross primary production (GPP at regional and global scales is essential for carbon budgets and climate change studies. Five models, the vegetation photosynthesis model (VPM, the temperature and greenness model (TG, the alpine vegetation model (AVM, the greenness and radiation model (GR, and the MOD17 algorithm, were tested and calibrated at eight sites in China during 2003–2005. Results indicate that the first four models provide more reliable GPP estimation than MOD17 products/algorithm, although MODIS GPP products show better performance in grasslands, croplands, and mixed forest (MF. VPM and AVM produce better estimates in forest sites (R2 = 0.68 and 0.67, respectively; AVM and TG models show satisfactory GPP estimates for grasslands (R2 = 0.91 and 0.9, respectively. In general, the VPM model is the most suitable model for GPP estimation for all kinds of land cover types in China, with R2 higher than 0.34 and root mean square error (RMSE lower than 48.79%. The relationships between eddy CO2 flux and model parameters (Enhanced Vegetation Index (EVI, photosynthetically active radiation (PAR, land surface temperature (LST, air temperature, and Land Surface Water Index (LSWI are further analyzed to investigate the model’s application to various land cover types, which will be of great importance for studying the effects of climatic factors on ecosystem performances.

  6. Do Stochastic Traffic Assignment Models Consider Differences in Road Users Utility Functions?

    DEFF Research Database (Denmark)

    Nielsen, Otto Anker

    1996-01-01

    The early stochastic traffic assignment models (e.g. Dial, 1971) build on the assump-tion that different routes are independent (the logit-model concept). Thus, the models gave severe problems in networks with overlapping routes. Daganzo & Sheffi (1977) suggested to use probit based models...

  7. Three-Mode Models and Individual Differences in Semantic Differential Data.

    Science.gov (United States)

    Murakami, Takashi; Kroonenberg, Pieter M.

    2003-01-01

    Demonstrated how individual differences in semantic differential data can be modeled and assessed using three-mode models by studying the characterization of Chopin's "Preludes" by 38 Japanese college students. (SLD)