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Sample records for models spotted owl

  1. Modeling of site occupancy dynamics for northern spotted owls, with emphasis on the effects of barred owls

    Science.gov (United States)

    Olson, Gail S.; Anthony, Robert G.; Forsman, Eric D.; Ackers, Steven H.; Loschl, Peter J.; Reid, Janice A.; Dugger, Katie M.; Glenn, Elizabeth M.; Ripple, William J.

    2005-01-01

    Northern spotted owls (Strix occidentalis caurina) have been studied intensively since their listing as a threatened species by the U.S. Fish and Wildlife Service in 1990. Studies of spotted owl site occupancy have used various binary response measures, but most of these studies have made the assumption that detectability is perfect, or at least high and not variable. Further, previous studies did not consider temporal variation in site occupancy. We used relatively new methods for open population modeling of site occupancy that incorporated imperfect and variable detectability of spotted owls and allowed modeling of temporal variation in site occupancy, extinction, and colonization probabilities. We also examined the effects of barred owl (S. varia) presence on these parameters. We used spotted owl survey data from 1990 to 2002 for 3 study areas in Oregon, USA, and we used program MARK to develop and analyze site occupancy models. We found per visit detection probabilities averaged variable among study years and study areas. Site occupancy probabilities for owl pairs declined greatly on 1 study area and slightly on the other 2 areas. For all owls, including singles and pairs, site occupancy was mostly stable through time. Barred owl presence had a negative effect on spotted owl detection probabilities, and it had either a positive effect on local-extinction probabilities or a negative effect on colonization probabilities. We conclude that further analyses of spotted owls must account for imperfect and variable detectability and barred owl presence to properly interpret results. Further, because barred owl presence is increasing within the range of northern spotted owls, we expect to see further declines in the proportion of sites occupied by spotted owls.

  2. Modeling co-occurrence of northern spotted and barred owls: accounting for detection probability differences

    Science.gov (United States)

    Bailey, Larissa L.; Reid, Janice A.; Forsman, Eric D.; Nichols, James D.

    2009-01-01

    Barred owls (Strix varia) have recently expanded their range and now encompass the entire range of the northern spotted owl (Strix occidentalis caurina). This expansion has led to two important issues of concern for management of northern spotted owls: (1) possible competitive interactions between the two species that could contribute to population declines of northern spotted owls, and (2) possible changes in vocalization behavior and detection probabilities of northern spotted owls induced by presence of barred owls. We used a two-species occupancy model to investigate whether there was evidence of competitive exclusion between the two species at study locations in Oregon, USA. We simultaneously estimated detection probabilities for both species and determined if the presence of one species influenced the detection of the other species. Model selection results and associated parameter estimates provided no evidence that barred owls excluded spotted owls from territories. We found strong evidence that detection probabilities differed for the two species, with higher probabilities for northern spotted owls that are the object of current surveys. Non-detection of barred owls is very common in surveys for northern spotted owls, and detection of both owl species was negatively influenced by the presence of the congeneric species. Our results suggest that analyses directed at hypotheses of barred owl effects on demographic or occupancy vital rates of northern spotted owls need to deal adequately with imperfect and variable detection probabilities for both species.

  3. Demographic response of northern spotted owls to barred owl removal

    Science.gov (United States)

    Diller, V. Lowell; Hamm, Keith A; Early, Desiree A; Lamphear, David W; Dugger, Katie M.; Yackulic, Charles B.; Schwarz, Carl J.; Carlson, Peter C.; McDonald, Trent L.

    2016-01-01

    Federally listed as threatened in 1990 primarily because of habitat loss, the northern spotted owl (Strix occidentalis caurina) has continued to decline despite conservation efforts resulting in forested habitat being reserved throughout its range. Recently, there is growing evidence the congeneric invasive barred owl (Strix varia) may be responsible for the continued decline primarily by excluding spotted owls from their preferred habitat. We used a long-term demographic study for spotted owls in coastal northern California as the basis for a pilot barred owl removal experiment. Our demography study used capture–recapture, reproductive output, and territory occupancy data collected from 1990 to 2013 to evaluate trends in vital rates and populations. We used a classic before-after-control-impact (BACI) experimental design to investigate the demographic response of northern spotted owls to the lethal removal of barred owls. According to the best 2-species dynamic occupancy model, there was no evidence of differences in barred or northern spotted owl occupancy prior to the initiation of the treatment (barred owl removal). After treatment, barred owl occupancy was lower in the treated relative to the untreated areas and spotted owl occupancy was higher relative to the untreated areas. Barred owl removal decreased spotted owl territory extinction rates but did not affect territory colonization rates. As a result, spotted owl occupancy increased in the treated area and continued to decline in the untreated areas. Prior to and after barred owl removal, there was no evidence that average fecundity differed on the 2 study areas. However, the greater number of occupied spotted owl sites on the treated areas resulted in greater productivity in the treated areas based on empirical counts of fledged young. Prior to removal, survival was declining at a rate of approximately 0.2% per year for treated and untreated areas. Following treatment, estimated survival was 0.859 for

  4. Mapping sources, sinks, and connectivity using a simulation model of Northern Spotted Owls

    Science.gov (United States)

    This is a study of source-sink dynamics at a landscape scale. In conducting the study, we make use of a mature simulation model for the northern spotted owl (Strix occidentalis caurina) that was developed as part of the US Fish and Wildlife Service’s most recent recovery plannin...

  5. Models for mapping potential habitat at landscape scales: an example using northern spotted owls.

    Science.gov (United States)

    William C. McComb; Michael T. McGrath; Thomas A. Spies; David. Vesely

    2002-01-01

    We are assessing the potential for current and alternative policies in the Oregon Coast Range to affect habitat capability for a suite of forest resources. We provide an example of a spatially explicit habitat capability model for northern spotted owls (Strix occidentalis caurina)to illustrate the approach we are taking to assess potential changes...

  6. Managing emerging threats to spotted owls

    Science.gov (United States)

    Ho Yi Wan; Joseph L. Ganey; Christina D. Vojta; Samuel A. Cushman

    2018-01-01

    The 3 spotted owl (Strix occidentalis) subspecies in North America (i.e., northern spotted owl [S. o. caurina], California spotted owl [S. o. occidentalis], Mexican spotted owl [S. o. lucida]) have all experienced population declines over the past century due to habitat loss and fragmentation from logging. Now, the emerging influences of climate change, high-severity...

  7. Modeling demographic performance of northern spotted owls relative to forest habitat in Oregon

    Science.gov (United States)

    Olson, Gail S.; Glenn, Elizabeth M.; Anthony, Robert G.; Forsman, Eric D.; Reid, Janice A.; Loschl, Peter J.; Ripple, William J.

    2004-01-01

    Northern spotted owls (Strix occidentalis caurina) are known to be associated with late-successional forests in the Pacific Northwest of the United States, but the effects of habitat on their demographic performance are relatively unknown. We developed statistical models relating owl survival and productivity to forest cover types within the Roseburg Study Area in the Oregon Coast Range of Oregon, USA. We further combined these demographic parameters using a Leslie-type matrix to obtain an estimate of habitat fitness potential for each owl territory (n = 94). We used mark–recapture methods to develop models for survival and linear mixed models for productivity. We measured forest composition and landscape patterns at 3 landscape scales centered on nest and activity sites within owl territories using an aerial photo-based map and a Geographic Information System (GIS). We also considered additional covariates such as age, sex, and presence of barred owls (Strix varia), and seasonal climate variables (temperature and precipitation) in our models. We used Akaike's Information Criterion (AIC) to rank and compare models. Survival had a quadratic relationship with the amount of late- and mid-seral forests within 1,500 m of nesting centers. Survival also was influenced by the amount of precipitation during the nesting season. Only 16% of the variability in survival was accounted for by our best model, but 85% of this was due to the habitat variable. Reproductive rates fluctuated biennially and were positively related to the amount of edge between late- and mid-seral forests and other habitat classes. Reproductive rates also were influenced by parent age, amount of precipitation during nesting season, and presence of barred owls. Our best model accounted for 84% of the variability in productivity, but only 3% of that was due to the habitat variable. Estimates of habitat fitness potential (which may range from 0 to infinity) for the 94 territories ranged from 0.74 to 1

  8. Estimating inbreeding rates in Northern Spotted Owls: insights from pedigrees and spatio-demographic models

    Science.gov (United States)

    The federally-threatened Northern Spotted Owl (Strix occidentalis caurina) has a substantial influence on management of federal lands. Despite decades of investigation, important details about its status and habits remain unknown. In particular, determining the frequency of inbre...

  9. Competitive interactions and resource partitioning between northern spotted owls and barred owls in western Oregon

    Science.gov (United States)

    Wiens, J. David; Anthony, Robert G.; Forsman, Eric D.

    2014-01-01

    with minimal spatial overlap among core-use areas. We used an information-theoretic approach to rank discrete-choice models representing alternative hypotheses about the influence of forest conditions, topography, and interspecific interactions on species-specific patterns of nighttime resource selection. Spotted owls spent a disproportionate amount of time foraging on steep slopes in ravines dominated by old (>120 yr) conifer trees. Barred owls used available forest types more evenly than spotted owls, and were most strongly associated with patches of large hardwood and conifer trees that occupied relatively flat areas along streams. Spotted and barred owls differed in the relative use of old conifer forest (greater for spotted owls) and slope conditions (steeper slopes for spotted owls), but we found no evidence that the 2 species differed in their use of young, mature, and riparian-hardwood forest types. Mean overlap in proportional use of different forest types between individual spotted owls and barred owls in adjacent territories was 81% (range = 30–99%). The best model of habitat use for spotted owls indicated that the relative probability of a location being used was substantially reduced if the location was within or in close proximity to a core-use area of a barred owl. We used pellet analysis and measures of food-niche overlap to determine the potential for dietary competition between spatially associated pairs of spotted owls and barred owls. We identified 1,223 prey items from 15 territories occupied by spotted owls and 4,299 prey items from 24 territories occupied by barred owls. Diets of both species were dominated by nocturnal mammals, but diets of barred owls included many terrestrial, aquatic, and diurnal prey species that were rare or absent in diets of spotted owls. Northern flying squirrels (Glaucomys sabrinus), woodrats (Neotoma fuscipes, N. cinerea), and lagomorphs (Lepus americanus, Sylvilagus bachmani) were primary prey for both owl

  10. Multistate Models Reveal Long-Term Trends of Northern Spotted Owls in the Absence of a Novel Competitor.

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    Andrew J Kroll

    Full Text Available Quantifying spatial and temporal variability in population trends is a critical aspect of successful management of imperiled species. We evaluated territory occupancy dynamics of northern spotted owls (Strix occidentalis caurina, California, USA, 1990-2014. The study area possessed two unique aspects. First, timber management has occurred for over 100 years, resulting in dramatically different forest successional and structural conditions compared to other areas. Second, the barred owl (Strix varia, an exotic congener known to exert significant negative effects on spotted owls, has not colonized the study area. We used a Bayesian dynamic multistate model to evaluate if territory occupancy of reproductive spotted owls has declined as in other study areas. The state-space approach for dynamic multistate modeling imputes the number of territories for each nesting state and allows for the estimation of longer-term trends in occupied or reproductive territories from longitudinal studies. The multistate approach accounts for different detection probabilities by nesting state (to account for either inherent differences in detection or for the use of different survey methods for different occupancy states and reduces bias in state assignment. Estimated linear trends in the number of reproductive territories suggested an average loss of approximately one half territory per year (-0.55, 90% CRI: -0.76, -0.33, in one management block and a loss of 0.15 per year (-0.15, 90% CRI: -0.24, -0.07, in another management block during the 25 year observation period. Estimated trends in the third management block were also negative, but substantial uncertainty existed in the estimate (-0.09, 90% CRI: -0.35, 0.17. Our results indicate that the number of territories occupied by northern spotted owl pairs remained relatively constant over a 25 year period (-0.07, 90% CRI: -0.20, 0.05; -0.01, 90% CRI: -0.19, 0.16; -0.16, 90% CRI: -0.40, 0.06. However, we cannot exclude

  11. Multistate Models Reveal Long-Term Trends of Northern Spotted Owls in the Absence of a Novel Competitor.

    Science.gov (United States)

    Kroll, Andrew J; Jones, Jay E; Stringer, Angela B; Meekins, Douglas J

    2016-01-01

    Quantifying spatial and temporal variability in population trends is a critical aspect of successful management of imperiled species. We evaluated territory occupancy dynamics of northern spotted owls (Strix occidentalis caurina), California, USA, 1990-2014. The study area possessed two unique aspects. First, timber management has occurred for over 100 years, resulting in dramatically different forest successional and structural conditions compared to other areas. Second, the barred owl (Strix varia), an exotic congener known to exert significant negative effects on spotted owls, has not colonized the study area. We used a Bayesian dynamic multistate model to evaluate if territory occupancy of reproductive spotted owls has declined as in other study areas. The state-space approach for dynamic multistate modeling imputes the number of territories for each nesting state and allows for the estimation of longer-term trends in occupied or reproductive territories from longitudinal studies. The multistate approach accounts for different detection probabilities by nesting state (to account for either inherent differences in detection or for the use of different survey methods for different occupancy states) and reduces bias in state assignment. Estimated linear trends in the number of reproductive territories suggested an average loss of approximately one half territory per year (-0.55, 90% CRI: -0.76, -0.33), in one management block and a loss of 0.15 per year (-0.15, 90% CRI: -0.24, -0.07), in another management block during the 25 year observation period. Estimated trends in the third management block were also negative, but substantial uncertainty existed in the estimate (-0.09, 90% CRI: -0.35, 0.17). Our results indicate that the number of territories occupied by northern spotted owl pairs remained relatively constant over a 25 year period (-0.07, 90% CRI: -0.20, 0.05; -0.01, 90% CRI: -0.19, 0.16; -0.16, 90% CRI: -0.40, 0.06). However, we cannot exclude small

  12. 78 FR 57171 - Experimental Removal of Barred Owls To Benefit Threatened Northern Spotted Owls; Record of...

    Science.gov (United States)

    2013-09-17

    ... spotted owls in many portions of the northern spotted owl's range (Pearson and Livezey 2003, p. 272... populations. Barred owls displace spotted owls from high-quality habitat (Kelley et al. 2003, p. 51; Pearson... management intervention, it is reasonable to expect that competition from barred owls may cause extirpation...

  13. Blood parasites in Owls with conservation implications for the Spotted Owl (Strix occidentalis)

    Science.gov (United States)

    Ishak, H.D.; Dumbacher, J.P.; Anderson, N.L.; Keane, J.J.; Valkiunas, G.; Haig, S.M.; Tell, L.A.; Sehgal, R.N.M.

    2008-01-01

    The three subspecies of Spotted Owl (Northern, Strix occidentalis courina; California, S. o. occidentalis; and Mexican, S. o. lucida) are all threatened by habitat loss and range expansion of the Barred Owl (S. varia). An unaddressed threat is whether Barred Owls could be a source of novel strains of disease such as avian malaria (Plasmodium spp.) or other blood parasites potentially harmful for Spotted Owls. Although Barred Owls commonly harbor Plasmodium infections, these parasites have not been documented in the Spotted Owl. We screened 111 Spotted Owls, 44 Barred Owls, and 387 owls of nine other species for haemosporidian parasites (Leucocytozoon, Plasmodium, and Haemoproteus spp.). California Spotted Owls had the greatest number of simultaneous multi-species infections (44%). Additionally, sequencing results revealed that the Northern and California Spotted Owl subspecies together had the highest number of Leucocytozoon parasite lineages (n=17) and unique lineages (n=12). This high level of sequence diversity is significant because only one leucocytozoon species (L. danilewskyi) has been accepted as valid among all owls, suggesting that L. danilewskyi is a cryptic species. Furthermore, a Plasmodium parasite was documented in a Northern Spotted Owl for the first time. West Coast Barred Owls had a lower prevalence of infection (15%) when compared to sympatric Spotted Owls (S. o. caurina 52%, S. o. occidentalis 79%) and Barred Owls from the historic range (61%). Consequently, Barred Owls on the West Coast may have a competitive advantage over the potentially immune compromised Spotted Owls. ?? 2008 Ishak et al.

  14. 78 FR 44588 - Experimental Removal of Barred Owls To Benefit Threatened Northern Spotted Owls; Final...

    Science.gov (United States)

    2013-07-24

    ... spotted owl populations and to test the feasibility and efficiency of barred owl removal as a management... outnumber spotted owls in many portions of the northern spotted owl's range (Pearson and Livezey 2003, p.... 51; Pearson and Livezey 2003, p. 274; Courtney et al., pp. 7-27 through 7-31; Gremel 2005, pp. 9, 11...

  15. Application of Bayesian methods to habitat selection modeling of the northern spotted owl in California: new statistical methods for wildlife research

    Science.gov (United States)

    Howard B. Stauffer; Cynthia J. Zabel; Jeffrey R. Dunk

    2005-01-01

    We compared a set of competing logistic regression habitat selection models for Northern Spotted Owls (Strix occidentalis caurina) in California. The habitat selection models were estimated, compared, evaluated, and tested using multiple sample datasets collected on federal forestlands in northern California. We used Bayesian methods in interpreting...

  16. The effects of habitat, climate, and Barred Owls on long-term demography of Northern Spotted Owls

    Science.gov (United States)

    Dugger, Catherine; Forsman, Eric D.; Franklin, Alan B.; Davis, Raymond J.; White, Gary C.; Schwarz, Carl J.; Burnham, Kenneth P.; Nichols, James D.; Hines, James E.; Yackulic, Charles B.; Doherty, Paul F.; Bailey, Larissa; Clark, Darren A.; Ackers, Steven H.; Andrews, Lawrence S.; Augustine, Benjamin; Biswell, Brian L.; Blakesley, Jennifer; Carlson, Peter C.; Clement, Matthew J.; Diller, Lowell V.; Glenn, Elizabeth M.; Green, Adam; Gremel, Scott A.; Herter, Dale R.; Higley, J. Mark; Hobson, Jeremy; Horn, Rob B.; Huyvaert, Kathryn P.; McCafferty, Christopher; McDonald, Trent; McDonnell, Kevin; Olson, Gail S.; Reid, Janice A.; Rockweit, Jeremy; Ruiz, Viviana; Saenz, Jessica; Sovern, Stan G.

    2016-01-01

    Estimates of species' vital rates and an understanding of the factors affecting those parameters over time and space can provide crucial information for management and conservation. We used mark–recapture, reproductive output, and territory occupancy data collected during 1985–2013 to evaluate population processes of Northern Spotted Owls (Strix occidentalis caurina) in 11 study areas in Washington, Oregon, and northern California, USA. We estimated apparent survival, fecundity, recruitment, rate of population change, and local extinction and colonization rates, and investigated relationships between these parameters and the amount of suitable habitat, local and regional variation in meteorological conditions, and competition with Barred Owls (Strix varia). Data were analyzed for each area separately and in a meta-analysis of all areas combined, following a strict protocol for data collection, preparation, and analysis. We used mixed effects linear models for analyses of fecundity, Cormack-Jolly-Seber open population models for analyses of apparent annual survival (ϕ), and a reparameterization of the Jolly-Seber capture–recapture model (i.e. reverse Jolly-Seber; RJS) to estimate annual rates of population change (λRJS) and recruitment. We also modeled territory occupancy dynamics of Northern Spotted Owls and Barred Owls in each study area using 2-species occupancy models. Estimated mean annual rates of population change (λ) suggested that Spotted Owl populations declined from 1.2% to 8.4% per year depending on the study area. The weighted mean estimate of λ for all study areas was 0.962 (± 0.019 SE; 95% CI: 0.925–0.999), indicating an estimated range-wide decline of 3.8% per year from 1985 to 2013. Variation in recruitment rates across the range of the Spotted Owl was best explained by an interaction between total winter precipitation and mean minimum winter temperature. Thus, recruitment rates were highest when both total precipitation (29 cm) and

  17. The scientific basis for modeling Northern Spotted Owl habitat: A response to Loehle, Irwin, Manly, and Merrill

    Science.gov (United States)

    Jeffrey R. Dunk; Brian Woodbridge; Elizabeth M. Glenn; Raymond J. Davis; Katherine Fitzgerald; Paul Henson; David W. LaPlante; Bruce G. Marcot; Barry R. Noon; Martin G. Raphael; Nathan H. Schumaker; Brendan. White

    2015-01-01

    The U.S. Fish and Wildlife Service recently revised the recovery plan (USFWS, 2011) and designated Critical Habitat (USFWS, 2012a) for the Northern Spotted Owl (Strix occidentalis caurina). The Critical Habitat designation was based in part on a map of relative habitat suitability that was developed by USFWS (2011, 2012b) for this purpose. Loehle...

  18. Demography of Northern Spotted Owls in southwestern Oregon

    Science.gov (United States)

    Zabel, Cynthia J.; Salmons, Susan E.; Forsman, Eric D.; DeStefano, Stephen; Raphael, Martin G.; Gutierrez, R.J.

    1996-01-01

    Northern Spotted Owls (Strix occidentalis caurina) are associated with lower elevation, commercially valuable, late-successional coniferous forests in the Pacific Northwest. Meta-analyses of demographic parameters indicate that Northern Spotted Owl populations are declining throughout their range (Anderson and Burnham 1992, Burnham et al. this volume). Recent research has attempted to determine whether management activities have affected the viability of Spotted Owl populations, and results have led to development of conservation plans for the species (Dawson et al. 1987, Thomas et al. 1990, Murphy and Noon 1992, USDI 1992, Thomas et al. 1993b).In the Recovery Plan for the Northern Spotted Owl (USDI 1992b) threats to the species were identified as small population sizes, declining populations, limited amounts of habitat, continued loss and fragmentation of habitat, geographically isolated populations, and predation and competition from other avian species. Weather and fire are natural processes that also may affect reproductive success of Spotted Owls. Weather may be a factor in the high annual variability in fecundity of Spotted Owls, as has been suggested for other predatory bird species (Newton, 1979, 1986). However, these factors have not been addressed in previous studies of Spotted Owls.Our objectives were to estimate survival, fecundity, and annual rates of population change (l) for resident, territorial female Spotted Owls at two study areas in the coastal mountains of southwestern Oregon. We tested if the amount of rainfall was correlated with reproduction of Spotted Owls. While surveying for Spotted Owls, we documented the increased presence of Barred Owls (Strix varia), a potential competitor of Spotted Owls.

  19. Cover of tall trees best predicts California spotted owl habitat

    Science.gov (United States)

    Malcolm P. North; Jonathan T. Kane; Van R. Kane; Gregory P. Asner; William Berigan; Derek J. Churchill; Scott Conway; R.J. Gutiérrez; Sean Jeronimo; John Keane; Alexander Koltunov; Tina Mark; Monika Moskal; Thomas Munton; Zachary Peery; Carlos Ramirez; Rahel Sollmann; Angela White; Sheila Whitmore

    2017-01-01

    Restoration of western dry forests in the USA often focuses on reducing fuel loads. In the range of the spotted owl, these treatments may reduce canopy cover and tree density, which could reduce preferred habitat conditions for the owl and other sensitive species. In particular, high canopy cover (≥70%) has been widely reported to be an important feature of spotted owl...

  20. Food habits of Mexican Spotted Owls in Arizona

    Science.gov (United States)

    Joseph L. Ganey

    1992-01-01

    The Spotted Owl (Strix occidentalis) is most common in mature and old-growth coniferous forests throughout much of its range (Forsman et al. 1984, Laymon 1988, Ganey and Balda 1989a, Thomas et al. 1990). Proximate factors underlying habitat selection in Spotted Owls are understood poorly. Abundance and availability of food, however, may be a key...

  1. Population dynamics of spotted owls in the Sierra Nevada, California

    Science.gov (United States)

    Blakesley, J.A.; Seamans, M.E.; Conner, M.M.; Franklin, A.B.; White, Gary C.; Gutierrez, R.J.; Hines, J.E.; Nichols, J.D.; Munton, T.E.; Shaw, D.W.H.; Keane, J.J.; Steger, G.N.; McDonald, T.L.

    2010-01-01

    The California spotted owl (Strix occidentalis occidentalis) is the only spotted owl subspecies not listed as threatened or endangered under the United States Endangered Species Act despite petitions to list it as threatened. We conducted a meta-analysis of population data for 4 populations in the southern Cascades and Sierra Nevada, California, USA, from 1990 to 2005 to assist a listing evaluation by the United States Fish and Wildlife Service. Our study areas (from N to S) were on the Lassen National Forest (LAS), Eldorado National Forest (ELD), Sierra National Forest (SIE), and Sequoia and Kings Canyon National Parks (SKC). These study areas represented a broad spectrum of habitat and management conditions in these mountain ranges. We estimated apparent survival probability, reproductive output, and rate of population change for spotted owls on individual study areas and for all study areas combined (meta-analysis) using model selection or model-averaging based on maximum-likelihood estimation. We followed a formal protocol to conduct this analysis that was similar to other spotted owl meta-analyses. Consistency of field and analytical methods among our studies reduced confounding methodological effects when evaluating results. We used 991 marked spotted owls in the analysis of apparent survival. Apparent survival probability was higher for adult than for subadult owls. There was little difference in apparent survival between male and female owls. Model-averaged mean estimates of apparent survival probability of adult owls varied from 0.811 ?? 0.021 for females at LAS to 0.890 ?? 0.016 for males at SKC. Apparent survival increased over time for owls of all age classes at LAS and SIE, for adults at ELD, and for second-year subadults and adults at SKC. The meta-analysis of apparent survival, which included only adult owls, confirmed an increasing trend in survival over time. Survival rates were higher for owls on SKC than on the other study areas. We analyzed data

  2. Survival and reproduction of radio-marked adult spotted owls.

    Science.gov (United States)

    C.C. Foster; E.D. Forsman; E.C. Meslow; G.S. Miller; J.A. Reid; F.F. Wagner; A.B. Carey; J.B. Lint

    1992-01-01

    We compared survival, reproduction, and body mass of radio-marked and non radio-marked spotted owls (Strix occidentalis) to determine if backpack radios influenced reproduction or survival. In most study areas and years, there were no differences (P > 0.05) in survival of males and females or in survival of radio-marked versus banded owls. There...

  3. Methods and materials, for locating and studying spotted owls.

    Science.gov (United States)

    Eric D. Forsman

    1983-01-01

    Nocturnal calling surveys are the most effective and most frequently used technique for locating spotted owls. Roosts and general nest locations may be located during the day by calling in suspected roost or nest areas. Specific nest trees are located by: (1) baiting with a live mouse to induce owls to visit the nest, (2) calling in suspected nest areas to stimulate...

  4. Life-history tradeoffs and reproductive cycles in Spotted Owls

    Science.gov (United States)

    Stoelting, Ricka E.; Gutierrez, R.J.; Kendall, William L.; Peery, M. Zachariah

    2015-01-01

    The study of tradeoffs among life-history traits has long been key to understanding the evolution of life-history strategies. However, more recently, evolutionary ecologists have realized that reproductive costs have the potential to influence population dynamics. Here, we tested for costs of reproduction in the California Spotted Owl (Strix occidentalis occidentalis), and assessed whether costs of reproduction in year t − 1 on reproduction in year t could be responsible for regionally synchronized biennial cycles in reproductive output. Logistic regression analysis and multistate mark–recapture models with state uncertainty revealed that breeding reduced the likelihood of reproducing in the subsequent year by 16% to 38%, but had no influence on subsequent survival. We also found that costs of reproduction in year t − 1 were correlated with climatic conditions in year t, with evidence of higher costs during the dry phase of the El Niño–Southern Oscillation. Using a simulation-based population model, we showed that strong reproductive costs had the potential to create biennial cycles in population-level reproductive output; however, estimated costs of reproduction appeared to be too small to explain patterns observed in Spotted Owls. In the absence of strong reproductive costs, we hypothesize that observed natural cycles in the reproductive output of Spotted Owls are related to as-yet-unmeasured, regionally concordant fluctuations in environmental conditions or prey resources. Despite theoretical evidence for demographic effects, our analyses illustrate that linking tradeoffs to actual changes in population processes will be challenging because of the potential confounding effects of individual and environmental variation.

  5. Model Problems in Technologies for Interoperability: OWL Web Ontology Language for Services (OWL-S)

    National Research Council Canada - National Science Library

    Metcalf, Chris; Lewis, Grace A

    2006-01-01

    .... The OWL Web Ontology Language for Services (OWL-S) is a language to describe the properties and capabilities of Web Services in such a way that the descriptions can be interpreted by a computer system in an automated manner. This technical note presents the results of applying the model problem approach to examine the feasibility of using OWL-S to allow applications to automatically discover, compose, and invoke services in a dynamic services-oriented environment.

  6. Spotted owl roost and nest site selection in northwestern California

    Science.gov (United States)

    J.A. Blakesley; A.B. Franklin; R.J. Gutierrez

    1992-01-01

    We directly observed roost and nest site selection in a population of northern spotted owls (Strix occidentalis caurina) in northwestern California during 1985-89. Because of potential biases caused by use of radio telemetry in previous studies, we examined habitat use relative to habitat availability at a level not previously reported for spotted...

  7. Conflicting perspectives on spotted owls, wildfire, and forest restoration

    Science.gov (United States)

    Joseph L. Ganey; Ho Yi Wan; Samuel A. Cushman; Christina D. Vojta

    2017-01-01

    Evidence of increasing fire extent and severity in the western US in recent decades has raised concern over the effects of fire on threatened species such as the spotted owl (Strix occidentalis Xantus de Vesey), which nests in forests with large trees and high canopy cover that are vulnerable to high-severity wildfire. A dichotomy of views exists on the impact of high-...

  8. Diets of California spotted owls in the Sierra National Forest

    Science.gov (United States)

    Thomas E. Munton; Kenneth D. Johnson; George N. Steger; Gary P. Eberlein

    2002-01-01

    From May 1987 through October 1992 and from July through August 1998, we studied diets of California spotted owls (Strix occidentalis occidentalis). Regurgitated pellets were collected at roost and nest sites between 1,000 and 7,600 ft elevation in the Sierra National Forest and were examined for remnant bones, feathers, and insect exoskeletons....

  9. Association of weather and nest-site structure with reproductive success in California spotted owls

    Science.gov (United States)

    Malcolm North; George Steger; Renee Denton; Gary Eberlein; Tom Munton; Ken Johnson

    2000-01-01

    Although the spotted owl (Strix occidentalis) has been intensively studied, factors influencing its reproduction are not well understood. We examined a 9-year demographic study of 51-86 pairs of the California spotted owl (S. o. occidentalis), weather conditions, and forest structure at nest sites in oak (Quercus sp.) woodland and...

  10. Nest reuse by Northern Spotted Owls on the east slope of the Cascade Range, Washington

    Science.gov (United States)

    Stan G. Sovern; Margaret Taylor; Eric D. Forsman

    2011-01-01

    During a long-term demography study of Northern Spotted Owls (Strix occidentalis caurina) in the eastern Cascade Range of Washington State in 1989 to 2008, we documented 276 nests of Northern Spotted Owls at 73 different territories. Of these nests, 90.2% were on platforms, mostly in clumps of deformed limbs caused by dwarf mistletoe (primarily...

  11. Avian trichomonosis in spotted owls (Strix occidentalis: Indication of opportunistic spillover from prey

    Directory of Open Access Journals (Sweden)

    Krysta H. Rogers

    2016-12-01

    Full Text Available Avian trichomonosis, caused by the flagellated protozoan parasite Trichomonas gallinae, has variable pathogenicity among bird species ranging from asymptomatic infections to severe disease periodically manifesting in epidemic mortality. Traditionally, columbids are identified as highly susceptible to infection with occasional spillover into raptors that prey on infected birds. We identified avian trichomonosis in two dead California spotted owls (Strix occidentalis occidentalis and three dead northern spotted owls (S. o. caurina in California during 2011–2015; infection was confirmed in four owls by PCR. Pathologic lesions associated with trichomonosis in the owls included caseonecrotic lesions of the upper palate accompanied by oropharyngitis, cellulitis, myositis, and/or sinusitis. Spotted owls are known to mainly feed on small mammals; therefore, the source of infection as well as the significance of the disease in spotted owls is unclear. These owl trichomonosis cases coincided temporally and spatially with three trichomonosis epidemics in band-tailed pigeons (Patagioenas fasciata monilis. The same parasite, T. gallinae subtype A2, was isolated from the spotted owls and band-tailed pigeons, suggesting the owls became infected when opportunistically feeding on pigeons during mortality events. Avian trichomonosis is an important factor in the decline of the Pacific Coast band-tailed pigeon population with near-annual mortality events during the last 10 years and could have conservation implications for raptor species at risk, particularly those that are facing multiple threats.

  12. Effects of experimental removal of Barred Owls on population demography of Northern Spotted Owls in Washington and Oregon—2017 progress report

    Science.gov (United States)

    Wiens, J. David; Dugger, Katie M.; Lesmeister, Damon B.; Dilione, Krista E.; Simon, David C.

    2018-05-21

    Populations of Northern Spotted Owls (Strix occidentalis caurina; hereinafter referred to as Spotted Owl) are declining throughout this subspecies’ geographic range. Evidence indicates that competition with invading populations of Barred Owls (S. varia) has contributed significantly to those declines. A pilot study in California showed that localized removal of Barred Owls coupled with conservation of suitable forest conditions can slow or even reverse population declines of Spotted Owls. It remains unknown, however, whether similar results can be obtained in areas with different forest conditions, greater densities of Barred Owls, and fewer remaining Spotted Owls. During 2015–17, we initiated a before-after-control-impact (BACI) experiment at three study areas in Oregon and Washington to determine if removal of Barred Owls can improve population trends of Spotted Owls. Each study area had at least 20 years of pre-treatment demographic data on Spotted Owls, and represented different forest conditions occupied by the two owl species in the Pacific Northwest. This report describes research accomplishments and preliminary results from the first 2.5 years (March 2015–August 2017) of the planned 5-year experiment.

  13. Using detection dogs to conduct simultaneous surveys of northern spotted (Strix occidentalis caurina and barred owls (Strix varia.

    Directory of Open Access Journals (Sweden)

    Samuel K Wasser

    Full Text Available State and federal actions to conserve northern spotted owl (Strix occidentalis caurina habitat are largely initiated by establishing habitat occupancy. Northern spotted owl occupancy is typically assessed by eliciting their response to simulated conspecific vocalizations. However, proximity of barred owls (Strix varia-a significant threat to northern spotted owls-can suppress northern spotted owl responsiveness to vocalization surveys and hence their probability of detection. We developed a survey method to simultaneously detect both species that does not require vocalization. Detection dogs (Canis familiaris located owl pellets accumulated under roost sites, within search areas selected using habitat association maps. We compared success of detection dog surveys to vocalization surveys slightly modified from the U.S. Fish and Wildlife Service's Draft 2010 Survey Protocol. Seventeen 2 km × 2 km polygons were each surveyed multiple times in an area where northern spotted owls were known to nest prior to 1997 and barred owl density was thought to be low. Mitochondrial DNA was used to confirm species from pellets detected by dogs. Spotted owl and barred owl detection probabilities were significantly higher for dog than vocalization surveys. For spotted owls, this difference increased with number of site visits. Cumulative detection probabilities of northern spotted owls were 29% after session 1, 62% after session 2, and 87% after session 3 for dog surveys, compared to 25% after session 1, increasing to 59% by session 6 for vocalization surveys. Mean detection probability for barred owls was 20.1% for dog surveys and 7.3% for vocal surveys. Results suggest that detection dog surveys can complement vocalization surveys by providing a reliable method for establishing occupancy of both northern spotted and barred owl without requiring owl vocalization. This helps meet objectives of Recovery Actions 24 and 25 of the Revised Recovery Plan for the

  14. Comparative habitat use of sympatric Mexican spotted and great horned owls

    Science.gov (United States)

    Joseph L. Ganey; William M. Block; Jeffrey S. Jenness; Randolph A. Wilson

    1997-01-01

    To provide information on comparative habitat use, we studied radiotagged Mexican spotted owls (Strix occidentalis lucida: n = 13) and great horned owls (Bubo virginianus: n = 4) in northern Arizona. Home-range size (95% adaptive kernel estimate) did not differ significantly between species during either the breeding or nonbreeding...

  15. An indirect dispersal pathway for spotted knapweed seeds via deer mice and great-horned owls

    Science.gov (United States)

    Dean E. Pearson; Yvette K. Ortega

    2001-01-01

    Spotted Knapweed (Centaurea maculosa) seeds were found in the pellets of Great Horned Owls (Bubo virginianus). That apparently resulted from owls preying upon Deer Mice (Peromyscus maniculatus) which had incidentally consumed knapweed seeds while foraging for the larvae of biological control agents within...

  16. California Spotted Owl (Strix occidentalis occidentalis) habitat use patterns in a burned landscape

    Science.gov (United States)

    Eyes, Stephanie; Roberts, Susan L.; Johnson, Matthew D.

    2017-01-01

    Fire is a dynamic ecosystem process of mixed-conifer forests of the Sierra Nevada, but there is limited scientific information addressing wildlife habitat use in burned landscapes. Recent studies have presented contradictory information regarding the effects of stand-replacing wildfires on Spotted Owls (Strix occidentalis) and their habitat. While fire promotes heterogeneous forest landscapes shown to be favored by owls, high severity fire may create large canopy gaps that can fragment the closed-canopy habitat preferred by Spotted Owls. We used radio-telemetry to determine whether foraging California Spotted Owls (S. o. occidentalis) in Yosemite National Park, California, USA, showed selection for particular fire severity patch types within their home ranges. Our results suggested that Spotted Owls exhibited strong habitat selection within their home ranges for locations near the roost and edge habitats, and weak selection for lower fire severity patch types. Although owls selected high contrast edges with greater relative probabilities than low contrast edges, we did not detect a statistical difference between these probabilities. Protecting forests from stand-replacing fires via mechanical thinning or prescribed fire is a priority for management agencies, and our results suggest that fires of low to moderate severity can create habitat conditions within California Spotted Owls' home ranges that are favored for foraging.

  17. Metabolic rate and evaporative water loss of Mexican Spotted and Great Horned Owls

    Science.gov (United States)

    Joseph L. Ganey; Russell P. Balda; Rudy M. King

    1993-01-01

    We measured rates of oxygen consumption and evaporative water loss (EWL) of Mexican Spotted (Strix occidentalis lucida) and Great Horned (Bubo virginianus) owls in Arizona. Basal metabolic rate averaged 0.84 ccO2. g-1. h-1...

  18. The effects of habitat, climate, and Barred Owls on long-term demography of Northern Spotted Owls

    Science.gov (United States)

    Katie M. Dugger; Eric D. Forsman; Alan B. Franklin; Raymond J. Davis; Gary C. White; Carl J. Schwarz; Kenneth P. Burnham; James D. Nichols; James E. Hines; Charles B. Yackulic; Paul F. Doherty; Larissa Bailey; Darren A. Clark; Steven H. Ackers; Lawrence S. Andrews; Benjamin Augustine; Brian L. Biswell; Jennifer Blakesley; Peter C. Carlson; Matthew J. Clement; Lowell V. Diller; Elizabeth M. Glenn; Adam Green; Scott A. Gremel; Dale R. Herter; J. Mark Higley; Jeremy Hobson; Rob B. Horn; Kathryn P. Huyvaert; Christopher McCafferty; Trent McDonald; Kevin McDonnell; Gail S. Olson; Janice A. Reid; Jeremy Rockweit; Viviana Ruiz; Jessica Saenz; Stan G. Sovern

    2016-01-01

    Estimates of species’ vital rates and an understanding of the factors affecting those parameters over time and space can provide crucial information for management and conservation. We used mark–recapture, reproductive output, and territory occupancy data collected during 1985–2013 to evaluate population processes of Northern Spotted Owls (Strix occidentalis...

  19. Home range characteristics of Mexican Spotted Owls in the Rincon Mountains, Arizona

    Science.gov (United States)

    Willey, David W.; van Riper, Charles

    2014-01-01

    We studied a small isolated population of Mexican Spotted Owls (Strix occidentalis lucida) from 1996–1997 in the Rincon Mountains of Saguaro National Park, southeastern Arizona, USA. All mixed-conifer and pine-oak forest patches in the park were surveyed for Spotted Owls, and we located, captured, and radio-tagged 10 adult birds representing five mated pairs. Using radio-telemetry, we examined owl home range characteristics, roost habitat, and monitored reproduction within these five territories. Breeding season (Mar–Sep) home range size for 10 adult owls (95% adaptive kernel isopleths) averaged 267 ha (±207 SD), and varied widely among owls (range 34–652 ha). Mean home range size for owl pairs was 478 ha (±417 ha SD), and ranged from 70–1,160 ha. Owls that produced young used smaller home ranges than owls that had no young. Six habitat variables differed significantly between roost and random sites, including: percent canopy cover, number of trees, number of vegetation layers, average height of trees, average diameter of trees, and tree basal area. Radio-marked owls remained in their territories following small prescribed management fires within those territories, exhibiting no proximate effects to the presence of prescribed fire.

  20. Potential influences of climate and nest structure on spotted owl reproductive success: a biophysical approach.

    Directory of Open Access Journals (Sweden)

    Jeremy T Rockweit

    Full Text Available Many bird species do not make their own nests; therefore, selection of existing sites that provide adequate microclimates is critical. This is particularly true for owls in north temperate climates that often nest early in the year when inclement weather is common. Spotted owls use three main types of nest structures, each of which are structurally distinct and may provide varying levels of protection to the eggs or young. We tested the hypothesis that spotted owl nest configuration influences nest microclimate using both experimental and observational data. We used a wind tunnel to estimate the convective heat transfer coefficient (h(c of eggs in 25 potential nest configurations that mimicked 2 nest types (top-cavity and platform nests, at 3 different wind speeds. We then used the estimates of h(c in a biophysical heat transfer model to estimate how long it would take unattended eggs to cool from incubation temperature (~36 °C to physiological zero temperature (PZT; ~26 °C under natural environmental conditions. Our results indicated that the structural configuration of nests influences the cooling time of the eggs inside those nests, and hence, influences the nest microclimate. Estimates of time to PZT ranged from 10.6 minutes to 33.3 minutes. Nest configurations that were most similar to platform nests always had the fastest egg cooling times, suggesting that platform nests were the least protective of those nests we tested. Our field data coupled with our experimental results suggested that nest choice is important for the reproductive success of owls during years of inclement weather or in regions characterized by inclement weather during the nesting season.

  1. Effects of experimental removal of barred owls on population demography of northern spotted owls in Washington and Oregon—2015 progress report

    Science.gov (United States)

    Wiens, J. David; Dugger, Katie M.; Lewicki, Krista E.; Simon, David C.

    2016-03-14

    Evidence indicates that competition with newly established barred owls (Strix varia) is causing rapid declines in populations of northern spotted owls (Strix occidentalis caurina), and that the longterm persistence of spotted owls may be in question without additional management intervention. A pilot study in California showed that lethal removal of barred owls in combination with habitat conservation may be able to slow or even reverse population declines of spotted owls at local scales, but it remains unknown whether similar results can be obtained in larger areas with different forest conditions and where barred owls are more abundant. In 2015, we implemented a before-after-controlimpact (BACI) experimental design on two study areas in Oregon and Washington with at least 20 years of pre-treatment demographic data on spotted owls to determine if removal of barred owls can improve population trends of spatially associated spotted owls. Here we provide an overview of our research accomplishments and preliminary results in Oregon and Washington in 2015.

  2. Science verses political reality in delisting criteria for a threatened species: The Mexican spotted owl experience

    Science.gov (United States)

    Gary C. White; William M. Block; Joseph L. Ganey; William H. Moir; James P. Ward; Alan B. Franklin; Steven L. Spangle; Sarah E. Rinkevich; J. Robert Vahle; Frank P. Howe; James L. Dick

    1999-01-01

    The Mexican spotted owl (Strix occidentalis lucida) was listed as a threatened species under the Endangered Species Act (ESA) in April 1993 (USDI 1993). Concomitant with the listing of the owl, a recovery team was appointed to develop a plan to recover the owl, allowing for its removal from the list of threatened and endangered species. The recovery plan - "the...

  3. OWL references in ORM conceptual modelling

    Science.gov (United States)

    Matula, Jiri; Belunek, Roman; Hunka, Frantisek

    2017-07-01

    Object Role Modelling methodology is the fact-based type of conceptual modelling. The aim of the paper is to emphasize a close connection to OWL documents and its possible mutual cooperation. The definition of entities or domain values is an indispensable part of the conceptual schema design procedure defined by the ORM methodology. Many of these entities are already defined in OWL documents. Therefore, it is not necessary to declare entities again, whereas it is possible to utilize references from OWL documents during modelling of information systems.

  4. Modeling interactions betweenspotted owl and barred owl populations in fire-prone forests

    Science.gov (United States)

    Background / Question / Methods Efforts to conserve northern spotted owls (Strix occidentalis caurina) in the eastern Cascades of Washington must merge the challenges of providing sufficient structurally complex forest habitat in a fire-prone landscape with the limitations impos...

  5. Effects of post-fire logging on California spotted owl occupancy

    Directory of Open Access Journals (Sweden)

    Chad T. Hanson

    2018-01-01

    Full Text Available In fire-adapted forest ecosystems around the world, there has been growing concern about adverse impacts of post-fire logging on native biodiversity and ecological processes. This is also true in conifer forests of California, U.S.A. which are home to a rare and declining owl subspecies, the California spotted owl (Strix occidentalis occidentalis. While there has been recent concern about the California spotted owl occupancy in large fire areas where some territories have substantial high-severity fire effects, the influence of post-fire logging on the California spotted owl occupancy has been investigated very little, leading to some uncertainty about interpretation of conflicting results in different large fires. Research has found these owls preferentially select high-severity fire areas, characterised by high levels of snags and native shrubs, for foraging in forests that were not logged after fire, suggesting that removal of this foraging habitat might impact occupancy. The authors assessed the effect of post-fire logging and high-severity fire, on occupancy of this subspecies in eight large fire areas, within spotted owl sites with two different levels of high-severity fire effects. They found a significant adverse effect of such logging and no effect of high-severity fire alone. These results indicate it is post-fire logging, not large fires themselves, that poses a conservation threat to this imperilled species.

  6. A quantitative evaluation of the conservation umbrella of spotted owl management areas in the Sierra Nevada.

    Directory of Open Access Journals (Sweden)

    Ryan D Burnett

    Full Text Available Whether by design or default, single species management often serves as an umbrella for species with similar habitat requirements. In recent decades the focus of National Forest management in the Sierra Nevada of California has shifted towards increasing closed canopy mature forest conditions through the protection of areas occupied by the California Spotted Owl (Strix occidentalis occidentalis. To evaluate the implications of these habitat changes and the potential umbrella resulting from a system of owl reserves on the broader avian community, we estimated occupancy of birds inside and outside of Spotted Owl Home Range Core Areas in northeastern California. We used point count data in a multi-species hierarchical Bayesian model incorporating the detection history of 81 species over a two-year time period (2005-2006. A small set of vegetation cover and topography covariates were included in the model to account for broad differences in habitat conditions, as well as a term identifying whether or not a site was within a Core Area. Seventeen species had a negative Core Area effect, seven had a positive effect, and the rest were not significant. Estimated species richness was significantly different with 23.1 species per 100 m radius circle outside Core Areas and 21.7 inside Core Areas. The majority of the species negatively associated with Core Areas are tied to early successional and other disturbance-dependent habitats. Conservation and climate vulnerability rankings were mixed. On average we found higher scores (greater risk for the species positively associated with Core Areas, but a larger number of species with the highest scores were negatively associated with Core Areas. We discuss the implications for managing the Sierra Nevada ecosystem and illustrate the role of monitoring broader suites of species in guiding management of large complex ecosystems.

  7. Chapter 4: Northern spotted owl habitat and populations: Status and threats

    Science.gov (United States)

    Lesmeister, Damon B.; Davis, Ramond J; Singleton, Peter H; Wiens, David

    2018-01-01

    The northern spotted owl (Strix occidentalis caurina) was listed as threatened under the Endangered Species Act in 1990 (USFWS 1990). Providing adequate amounts of suitable forest cover to sustain the subspecies was a major component of the first recovery plan for northern spotted owls (USFWS 1992) and a driver in the basic reserve design and old-forest restoration under the Northwest Forest Plan (NWFP, or Plan) (USDA and USDI 1994). The reserve design included large contiguous blocks of late-successional forest, which was expected to be sufficient to provide habitat for many interacting pairs of northern spotted owls. As such, the selection of reserves generally favored areas with the highest quality old-growth

  8. Spotted owl ecology: theory and methodology—a reply to Rosenberg et al.

    Science.gov (United States)

    A.B. Carey

    1995-01-01

    In their remarks on the study of Spotted Owls (Strix occidentalis) by Carey et al. (1992). Rosenberg et al. (1994) questioned the appropriateness of certain analyses and methods, and specific interpretation of the results. Herein, I respond to the comments of Rosenberg et al. (1994), which are summarized in italics.Sample sizes were nor...

  9. Late-successional forests and northern spotted owls: how effective is the Northwest Forest Plan?

    Science.gov (United States)

    Miles Hemstrom; Martin G. Raphael

    2000-01-01

    This paper describes the late-successional and old-growth forest and the northern spotted owl effectiveness monitoring plans for the Northwest Forest Plan. The effectiveness monitoring plan for late-successional and old-growth forests will track changes in forest spatial distribution, and within-stand structure and composition, and it will predict future trends.

  10. 77 FR 50526 - Proposed Safe Harbor Agreement for the Northern Spotted Owl, Skamania, Klickitat, and Yakima...

    Science.gov (United States)

    2012-08-21

    ... possibly that spotted owls are not responding to traditional survey methods. As of 2011, only one site... the following methods. You may request hard copies or a CD-ROM of the documents. Email: [email protected] marginal habitat,'' if the conditions associated with that habitat are verified by surveys using...

  11. Abundance and population characteristics of Northern Spotted Owls (Strix occidentalis caurina) in Olympic National Park, Washington

    Science.gov (United States)

    D. Erran Seaman

    1997-01-01

    We monitored the threatened Northern Spotted Owl (Strix occidentalis caurina) in Olympic National Park from 1992 through 1996. We used a stratified random sampling scheme to survey 35 plots totaling 236 km?, approximately 10 percent of the forested area of the park.

  12. Management of the spotted owl: a case history in conservation biology

    Science.gov (United States)

    B.R. Noon; K.S. McKelvey

    1996-01-01

    Official conservation efforts for the northern spotted owl began in the United States in 1975 when it was declared “threatened” in the state of Oregon; efforts continued in a sporadic and unsystematic way through the 1980s. In 1989 the Interagency Scientific Committee (ISC) was established by Congress and charged with the development of a scientifically defensible...

  13. Developing and managing sustainable forest ecosystems for spotted owls in the Sierra Nevada

    Science.gov (United States)

    J. Verner; K.S. McKelvey

    1994-01-01

    Studies of the California spotted owl have revealed significant selection for habitats with large, old trees; relatively high basal areas of snags; and relatively high biomass in large, downed logs. Based on planning documents for national forests in the Sierra Nevada, we projected declining amounts of older-forest attributes. Region 5 has adopted measures to retain...

  14. Effects of new export rules, a spotted owl plan, and recession on timber prices and shipments from the Douglas-fir region.

    Science.gov (United States)

    Donald F. Flora; Wendy J. McGInnls

    1992-01-01

    Several recently emplaced and potential Northwest timber policies are causing considerable market turbulence. Estimated were price and volume changes induced by three supply-side policies (a state-log export embargo, forest replanning, and spotted owl reservations) and the demand slide of 1990-91. Impacts were gauged separately and together by using a four-sector model...

  15. Preliminary risk assessment of the Mexican Spotted Owl under a spatially-weighted foraging regime at the Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Gallegos, A.F.; Gonzales, G.J.; Bennett, K.D.; Pratt, L.E.

    1997-02-01

    The Record of Decision on the Dual Axis Radiographic Hydrodynamic Test Facility at the Los Alamos National Laboratory requires that the Department of Energy takes special precautions to protect the Mexican Spotted Owl (Strix occidentalis lucida). In order to do so, risk to the owl presented by radiological and nonradiological contaminants must be estimated. A preliminary risk assessment on the Mexican Spotted Owl in two Ecological Exposure Units (EEUs) was performed using a modified Environmental Protection Agency Quotient method, the FORTRAN model ECORSK4, and a geographic information system. Estimated doses to the owl under a spatially-weighted foraging regime were compared against toxicological reference doses generating hazard indices (HIs) and hazard quotients (HQs) for three risk source types. The average HI was 0.20 for EEU-21 and 0.0015 for EEU-40. Under the risk parameter assumptions made, hazard quotient results indicated no unacceptable risk to the owl, including a measure of cumulative effects from multiple contaminants that assumes a linear additive toxicity type. An HI of 1.0 was used as the evaluative criteria for determining the acceptability of risk. This value was exceeded (1.06) in only one of 200 simulated potential nest sites. Cesium-137, Ni, {sup 239}Pu, Al and {sup 234}U we`re among the constituents with the highest partial HQs. Improving model realism by weighting simulated owl foraging based on distance from potential nest sites decreased the estimated risk by 72% (0.5 HI units) for EEU-21 and by 97.6% (6.3E-02 HI units) for EEU-40. Information on risk by specific geographical location was generated, which can be used to manage contaminated areas, owl habitat, facility siting, and/or facility operations in order to maintain risk from contaminants at acceptably low levels.

  16. Preliminary risk assessment of the Mexican Spotted Owl under a spatially-weighted foraging regime at the Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Gallegos, A.F.; Gonzales, G.J.; Bennett, K.D.; Pratt, L.E.

    1997-02-01

    The Record of Decision on the Dual Axis Radiographic Hydrodynamic Test Facility at the Los Alamos National Laboratory requires that the Department of Energy takes special precautions to protect the Mexican Spotted Owl (Strix occidentalis lucida). In order to do so, risk to the owl presented by radiological and nonradiological contaminants must be estimated. A preliminary risk assessment on the Mexican Spotted Owl in two Ecological Exposure Units (EEUs) was performed using a modified Environmental Protection Agency Quotient method, the FORTRAN model ECORSK4, and a geographic information system. Estimated doses to the owl under a spatially-weighted foraging regime were compared against toxicological reference doses generating hazard indices (HIs) and hazard quotients (HQs) for three risk source types. The average HI was 0.20 for EEU-21 and 0.0015 for EEU-40. Under the risk parameter assumptions made, hazard quotient results indicated no unacceptable risk to the owl, including a measure of cumulative effects from multiple contaminants that assumes a linear additive toxicity type. An HI of 1.0 was used as the evaluative criteria for determining the acceptability of risk. This value was exceeded (1.06) in only one of 200 simulated potential nest sites. Cesium-137, Ni, 239 Pu, Al and 234 U we're among the constituents with the highest partial HQs. Improving model realism by weighting simulated owl foraging based on distance from potential nest sites decreased the estimated risk by 72% (0.5 HI units) for EEU-21 and by 97.6% (6.3E-02 HI units) for EEU-40. Information on risk by specific geographical location was generated, which can be used to manage contaminated areas, owl habitat, facility siting, and/or facility operations in order to maintain risk from contaminants at acceptably low levels

  17. Logistic quantile regression provides improved estimates for bounded avian counts: A case study of California Spotted Owl fledgling production

    Science.gov (United States)

    Cade, Brian S.; Noon, Barry R.; Scherer, Rick D.; Keane, John J.

    2017-01-01

    Counts of avian fledglings, nestlings, or clutch size that are bounded below by zero and above by some small integer form a discrete random variable distribution that is not approximated well by conventional parametric count distributions such as the Poisson or negative binomial. We developed a logistic quantile regression model to provide estimates of the empirical conditional distribution of a bounded discrete random variable. The logistic quantile regression model requires that counts are randomly jittered to a continuous random variable, logit transformed to bound them between specified lower and upper values, then estimated in conventional linear quantile regression, repeating the 3 steps and averaging estimates. Back-transformation to the original discrete scale relies on the fact that quantiles are equivariant to monotonic transformations. We demonstrate this statistical procedure by modeling 20 years of California Spotted Owl fledgling production (0−3 per territory) on the Lassen National Forest, California, USA, as related to climate, demographic, and landscape habitat characteristics at territories. Spotted Owl fledgling counts increased nonlinearly with decreasing precipitation in the early nesting period, in the winter prior to nesting, and in the prior growing season; with increasing minimum temperatures in the early nesting period; with adult compared to subadult parents; when there was no fledgling production in the prior year; and when percentage of the landscape surrounding nesting sites (202 ha) with trees ≥25 m height increased. Changes in production were primarily driven by changes in the proportion of territories with 2 or 3 fledglings. Average variances of the discrete cumulative distributions of the estimated fledgling counts indicated that temporal changes in climate and parent age class explained 18% of the annual variance in owl fledgling production, which was 34% of the total variance. Prior fledgling production explained as much of

  18. Demography of the California spotted owl in the Sierra National Forest and Sequoia/Kings Canyon National Parks

    Science.gov (United States)

    George N. Steger; Thomas E. Munton; Kenneth D. Johnson; Gary P. Eberlein

    2002-01-01

    Nine years (1990–1998) of demographic data on California spotted owls (Strix occidentalis occidentalis) in two study areas on the western slopes of the Sierra Nevada—one in the Sierra National Forest (SNF), the other in Sequoia/Kings Canyon National Parks (SNP)—are summarized. Numbers of territorial owls fluctuated from 85 to 50 in SNF and 80 to 58...

  19. Influence of primary prey on home-range size and habitat-use patterns of northern spotted owls (Strix occidentalis caurina)

    Science.gov (United States)

    Cynthia J. Zabel; Kevin S. McKelvey; James P. Ward

    1995-01-01

    Correlations between the home-range size of northern spotted owls (Strix occidentalis caurina) and proportion of their range in old-growth forest have been reported, but there are few data on the relationship between their home-range size and prey. The primary prey of spotted owls are wood rats and northern flying squirrels (Glaucomys sabrinus). Wood...

  20. Sexing young snowy owls

    Science.gov (United States)

    Seidensticker, M.T.; Holt, D.W.; Detienne, J.; Talbot, S.; Gray, K.

    2011-01-01

    We predicted sex of 140 Snowy Owl (Bubo scandiacus) nestlings out of 34 nests at our Barrow, Alaska, study area to develop a technique for sexing these owls in the field. We primarily sexed young, flightless owls (3844 d old) by quantifying plumage markings on the remiges and tail, predicting sex, and collecting blood samples to test our field predictions using molecular sexing techniques. We categorized and quantified three different plumage markings: two types of bars (defined as markings that touch the rachis) and spots (defined as markings that do not touch the rachis). We predicted sex in the field assuming that males had more spots than bars and females more bars than spots on the remiges and rectrices. Molecular data indicated that we correctly sexed 100% of the nestlings. We modeled the data using random forests and classification trees. Both models indicated that the number and type of markings on the secondary feathers were the most important in classifying nestling sex. The statistical models verified our initial qualitative prediction that males have more spots than bars and females more bars than spots on flight feathers P6P10 for both wings and tail feathers T1 and T2. This study provides researchers with an easily replicable and highly accurate method for sexing young Snowy Owls in the field, which should aid further studies of sex-ratios and sex-related variation in behavior and growth of this circumpolar owl species. ?? 2011 The Raptor Research Foundation, Inc.

  1. Multi-scale Mexican spotted owl (Strix occidentalis lucida) nest/roost habitat selection in Arizona and a comparison with single-scale modeling results

    Science.gov (United States)

    Brad C. Timm; Kevin McGarigal; Samuel A. Cushman; Joseph L. Ganey

    2016-01-01

    Efficacy of future habitat selection studies will benefit by taking a multi-scale approach. In addition to potentially providing increased explanatory power and predictive capacity, multi-scale habitat models enhance our understanding of the scales at which species respond to their environment, which is critical knowledge required to implement effective...

  2. Northern Spotted Owl (Strix occidentalis caurina) Genome: Divergence with the Barred Owl (Strix varia) and Characterization of Light-Associated Genes.

    Science.gov (United States)

    Hanna, Zachary R; Henderson, James B; Wall, Jeffrey D; Emerling, Christopher A; Fuchs, Jérôme; Runckel, Charles; Mindell, David P; Bowie, Rauri C K; DeRisi, Joseph L; Dumbacher, John P

    2017-10-01

    We report here the assembly of a northern spotted owl (Strix occidentalis caurina) genome. We generated Illumina paired-end sequence data at 90× coverage using nine libraries with insert lengths ranging from ∼250 to 9,600 nt and read lengths from 100 to 375 nt. The genome assembly is comprised of 8,108 scaffolds totaling 1.26 × 109 nt in length with an N50 length of 3.98 × 106 nt. We calculated the genome-wide fixation index (FST) of S. o. caurina with the closely related barred owl (Strix varia) as 0.819. We examined 19 genes that encode proteins with light-dependent functions in our genome assembly as well as in that of the barn owl (Tyto alba). We present genomic evidence for loss of three of these in S. o. caurina and four in T. alba. We suggest that most light-associated gene functions have been maintained in owls and their loss has not proceeded to the same extent as in other dim-light-adapted vertebrates. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  3. 76 FR 38575 - Endangered and Threatened Wildlife and Plants; Revised Recovery Plan for the Northern Spotted Owl...

    Science.gov (United States)

    2011-07-01

    ... document availability: revised recovery plan. SUMMARY: We, the U.S. Fish and Wildlife Service, announce the... concluded that the integrity of the agency decisionmaking process for the spotted owl recovery plan was... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [FWS-R1-ES-2011-N020; 10120...

  4. Food habits of the Northern Spotted Owl (Strix occidentalis caurina) at six nest sites in Washington?s east Cascades

    Science.gov (United States)

    Kenneth R. Bevis; Jo Ellen Richards; Gina M. King; Eric E. Hanson

    1997-01-01

    This paper reports on 245 pellet samples containing 479 identified prey items collected at six Northern Spotted Owl (Strix occidentalis caurina) breeding sites in the eastern portion of its range. The majority of prey (biomass) came from four species; northern flying squirrels (Glaucomys sabrinus), bushy-tailed woodrats (...

  5. Tutorial on Modeling VAT Rules Using OWL-DL

    DEFF Research Database (Denmark)

    Nielsen, Morten Ib; Simonsen, Jakob Grue; Larsen, Ken Friis

    . In an ERP setting such a model could reduce the Total Cost of Ownership (TCO) and increase the quality of the system. We have selected OWL-DL because we believe that description logic is suited for modeling VAT rules due to the decidability of important inference problems that are key to the way we plan...... to use the model and because OWL-DL is relatively intuitive to use....

  6. Semantically-Rigorous Systems Engineering Modeling Using Sysml and OWL

    Science.gov (United States)

    Jenkins, J. Steven; Rouquette, Nicolas F.

    2012-01-01

    The Systems Modeling Language (SysML) has found wide acceptance as a standard graphical notation for the domain of systems engineering. SysML subsets and extends the Unified Modeling Language (UML) to define conventions for expressing structural, behavioral, and analytical elements, and relationships among them. SysML-enabled modeling tools are available from multiple providers, and have been used for diverse projects in military aerospace, scientific exploration, and civil engineering. The Web Ontology Language (OWL) has found wide acceptance as a standard notation for knowledge representation. OWL-enabled modeling tools are available from multiple providers, as well as auxiliary assets such as reasoners and application programming interface libraries, etc. OWL has been applied to diverse projects in a wide array of fields. While the emphasis in SysML is on notation, SysML inherits (from UML) a semantic foundation that provides for limited reasoning and analysis. UML's partial formalization (FUML), however, does not cover the full semantics of SysML, which is a substantial impediment to developing high confidence in the soundness of any conclusions drawn therefrom. OWL, by contrast, was developed from the beginning on formal logical principles, and consequently provides strong support for verification of consistency and satisfiability, extraction of entailments, conjunctive query answering, etc. This emphasis on formal logic is counterbalanced by the absence of any graphical notation conventions in the OWL standards. Consequently, OWL has had only limited adoption in systems engineering. The complementary strengths and weaknesses of SysML and OWL motivate an interest in combining them in such a way that we can benefit from the attractive graphical notation of SysML and the formal reasoning of OWL. This paper describes an approach to achieving that combination.

  7. The contribution of federal and nonfederal habitat to persistence of the northern spotted owl on the Olympic Peninsula, Washington: report of the reanalysis team.

    Science.gov (United States)

    Richard S. Holthausen; Martin G. Raphael; Kevin S. McKelvey; Eric D. Forsman; Edward E. Starkey; D. Erran. Seaman

    1995-01-01

    We analyzed likely patterns of distribution and persistence of northern spotted owls (Strix occidentalis caurina) on the Olympic Peninsula. Analysis focused on the effects of Federal habitat under provisions of the Northwest Forest Plan; additional benefits to the owl population of different levels of habitat retention on non-Federal lands; effects of establishing a...

  8. Effects of forest management on California Spotted Owls: implications for reducing wildfire risk in fire‐prone forests.

    Science.gov (United States)

    Tempel, Douglas J; Gutiérrez, R J; Whitmore, Sheila A; Reetz, Matthew J; Stoelting, Ricka E; Berigan, William J; Seamans, Mark E; Zachariah Peery, M

    Management of many North American forests is challenged by the need to balance the potentially competing objectives of reducing risks posed by high-severity wildfires and protecting threatened species. In the Sierra Nevada, California, concern about high-severity fires has increased in recent decades but uncertainty exists over the effects of fuel-reduction treatments on species associated with older forests, such as the California Spotted Owl (Strix occidentalis occidentalis). Here, we assessed the effects of forest conditions, fuel reductions, and wildfire on a declining population of Spotted Owls in the central Sierra Nevada using 20 years of demographic data collected at 74 Spotted Owl territories. Adult survival and territory colonization probabilities were relatively high, while territory extinction probability was relatively low, especially in territories that had relatively large amounts of high canopy cover (≥70%) forest. Reproduction was negatively associated with the area of medium-intensity timber harvests characteristic of proposed fuel treatments. Our results also suggested that the amount of edge between older forests and shrub/sapling vegetation and increased habitat heterogeneity may positively influence demographic rates of Spotted Owls. Finally, high-severity fire negatively influenced the probability of territory colonization. Despite correlations between owl demographic rates and several habitat variables, life stage simulation (sensitivity) analyses indicated that the amount of forest with high canopy cover was the primary driver of population growth and equilibrium occupancy at the scale of individual territories. Greater than 90% of medium-intensity harvests converted high-canopy-cover forests into lower-canopy-cover vegetation classes, suggesting that landscape-scale fuel treatments in such stands could have short-term negative impacts on populations of California Spotted Owls. Moreover, high-canopy-cover forests declined by an average of

  9. Derivation of Event-B Models from OWL Ontologies

    Directory of Open Access Journals (Sweden)

    Alkhammash Eman H.

    2016-01-01

    Full Text Available The derivation of formal specifications from large and complex requirements is a key challenge in systems engineering. In this paper we present an approach that aims to address this challenge by building formal models from OWL ontologies. An ontology is used in the field of knowledge representation to capture a clear view of the domain and to produce a concise and unambiguous set of domain requirements. We harness the power of ontologies to handle inconsistency of domain requirements and produce clear, concise and unambiguous set of domain requirements for Event-B modelling. The proposed approach works by generating Attempto Controlled English (ACE from the OWL ontology and then maps the ACE requirements to develop Event-B models. ACE is a subset of English that can be unambiguously translated into first-order logic. There is an injective mapping between OWL ontology and a subset of ACE. ACE is a suitable interlingua for producing the mapping between OWL and Event-B models for many reasons. Firstly, ACE is easy to learn and understand, it hides the math of OWL and would be natural to use by everybody. Secondly ACE has a parser that converts ACE texts into Discourse Representation Structures (DRS. Finally, ACE can be extended to target a richer syntactic subset of Event-B which ultimately would facilitate the translation of ACE requirements to Event-B.

  10. Fatal spirochetosis due to a relapsing fever-like Borrelia sp. in northern spotted owl

    Science.gov (United States)

    Thomas, N.J.; Bunikis, J.; Barbour, A.G.; Wolcott, M.J.

    2002-01-01

    Acute septicemic spirochetosis was diagnosed in an adult male northern spotted owl (Strix occidentalis caurina) found dead in Kittitas County, Washington, USA. Gross necropsy findings included marked enlargement of the liver and spleen and serofibrinous deposits on the serous membranes lining the body cavities and the pericardial and perihepatic sacs. Microscopic observations included macrophage infiltration in the liver and spleen with mild thrombosis and multifocal necrosis, as well as hemorrhage and acute inflammation in the choroid plexus of the brain. No viruses or pathogenic bacteria were isolated from brain, liver, or spleen, and no parasites were found in blood smears or impression smears of the liver. Chlamydial culture attempts were unsuccessful and no chlamydial antibodies were detected in serum. In silver-stained microscopic sections and by transmission electron microscopy of liver, numerous long, thin, spiral-shaped bacteria were seen in the liver, spleen, cerebral ventricles, and within blood vessels in many organs. The organism was identified as a member of the Borrelia genus by sequence analysis of the PCR-amplified 16S rRNA gene. The most closely related species is B. hermsii, an agent of relapsing fever in humans in the western United States. This is the first report of a relapsing fever-related Borrelia in a wild bird.

  11. Meta-analysis of California Spotted Owl (Strix occidentalis occidentalis) territory occupancy in the Sierra Nevada: habitat associations and their implications for forest management

    Science.gov (United States)

    Douglas J. Tempel; John J. Keane; R. J. Gutierrez; Jared D. Wolfe; Gavin M. Jones; Alexander Koltunov; Carlos M. Ramirez; William J. Berigan; Claire V. Gallagher; Thomas E. Munton; Paula A. Shaklee; Sheila A. Whitmore; M. Zachariah Peery

    2016-01-01

    We assessed the occupancy dynamics of 275 California Spotted Owl (Strix occidentalis occidentalis) territories in 4 study areas in the Sierra Nevada, California, USA, from 1993 to 2011. We used Landsat data to develop maps of canopy cover for each study area, which we then used to quantify annual territory-specific habitat...

  12. Relative abundance of small mammals in nest core areas and burned wintering areas of Mexican spotted owls in the Sacramento Mountains, New Mexico

    Science.gov (United States)

    Joseph L. Ganey; Sean C. Kyle; Todd A. Rawlinson; Darrell L. Apprill; James P Ward

    2014-01-01

    Mexican Spotted Owls (Strix occidentalis lucida) are common in older forests within their range but also persist in many areas burned by wildfire and may selectively forage in these areas. One hypothesis explaining this pattern postulates that prey abundance increases in burned areas following wildfire. We observed movement to wintering areas within areas burned by...

  13. Simulating high spatial resolution high severity burned area in Sierra Nevada forests for California Spotted Owl habitat climate change risk assessment and management.

    Science.gov (United States)

    Keyser, A.; Westerling, A. L.; Jones, G.; Peery, M. Z.

    2017-12-01

    Sierra Nevada forests have experienced an increase in very large fires with significant areas of high burn severity, such as the Rim (2013) and King (2014) fires, that have impacted habitat of endangered species such as the California spotted owl. In order to support land manager forest management planning and risk assessment activities, we used historical wildfire histories from the Monitoring Trends in Burn Severity project and gridded hydroclimate and land surface characteristics data to develope statistical models to simulate the frequency, location and extent of high severity burned area in Sierra Nevada forest wildfires as functions of climate and land surface characteristics. We define high severity here as BA90 area: the area comprising patches with ninety percent or more basal area killed within a larger fire. We developed a system of statistical models to characterize the probability of large fire occurrence, the probability of significant BA90 area present given a large fire, and the total extent of BA90 area in a fire on a 1/16 degree lat/lon grid over the Sierra Nevada. Repeated draws from binomial and generalized pareto distributions using these probabilities generated a library of simulated histories of high severity fire for a range of near (50 yr) future climate and fuels management scenarios. Fuels management scenarios were provided by USFS Region 5. Simulated BA90 area was then downscaled to 30 m resolution using a statistical model we developed using Random Forest techniques to estimate the probability of adjacent 30m pixels burning with ninety percent basal kill as a function of fire size and vegetation and topographic features. The result is a library of simulated high resolution maps of BA90 burned areas for a range of climate and fuels management scenarios with which we estimated conditional probabilities of owl nesting sites being impacted by high severity wildfire.

  14. Barred Owl [ds8

    Data.gov (United States)

    California Natural Resource Agency — These data define the current range of Barred and hybrid Barred/Spotted Owls in California. The current range includes the coastal mountains of northern California...

  15. Models of spots and flares

    International Nuclear Information System (INIS)

    Mullan, D.J.

    1983-01-01

    Laboratory experiments in recent years have shown that there are many more ways to drive a plasma out of equilibrium than to preserve equilibrium. In that sense, it is perhaps easier to understand why flares should occur in a stellar atmosphere than why a long-lived feature such as a dark spot should persist. The author summarizes work on the equilibrium structure of cool spots in the sun and stars. Since spots involve complex interactions between convective flows and magnetic fields, he needs to refer to observations for help in identifying the dominant processes which should enter into the modelling. His summary therefore begins by discussing certain relevant properties of spots in the solar atmosphere. The next sections deal with the magnetic fields in spots, the stability of spots, spot cooling and missing flux. The author concludes that spots should be viewed not simply as cool areas, but rather as engines which do the work of converting the energy of convective flows into flare-compatible form. (Auth.)

  16. The evolution of mapping habitat for northern spotted owls (Strix occidentalis caurina): A comparison of photo-interpreted, Landsat-based, and lidar-based habitat maps

    Science.gov (United States)

    Ackers, Steven H.; Davis, Raymond J.; Olsen, K.; Dugger, Catherine

    2015-01-01

    Wildlife habitat mapping has evolved at a rapid pace over the last few decades. Beginning with simple, often subjective, hand-drawn maps, habitat mapping now involves complex species distribution models (SDMs) using mapped predictor variables derived from remotely sensed data. For species that inhabit large geographic areas, remote sensing technology is often essential for producing range wide maps. Habitat monitoring for northern spotted owls (Strix occidentalis caurina), whose geographic covers about 23 million ha, is based on SDMs that use Landsat Thematic Mapper imagery to create forest vegetation data layers using gradient nearest neighbor (GNN) methods. Vegetation data layers derived from GNN are modeled relationships between forest inventory plot data, climate and topographic data, and the spectral signatures acquired by the satellite. When used as predictor variables for SDMs, there is some transference of the GNN modeling error to the final habitat map.Recent increases in the use of light detection and ranging (lidar) data, coupled with the need to produce spatially accurate and detailed forest vegetation maps have spurred interest in its use for SDMs and habitat mapping. Instead of modeling predictor variables from remotely sensed spectral data, lidar provides direct measurements of vegetation height for use in SDMs. We expect a SDM habitat map produced from directly measured predictor variables to be more accurate than one produced from modeled predictors.We used maximum entropy (Maxent) SDM modeling software to compare predictive performance and estimates of habitat area between Landsat-based and lidar-based northern spotted owl SDMs and habitat maps. We explored the differences and similarities between these maps, and to a pre-existing aerial photo-interpreted habitat map produced by local wildlife biologists. The lidar-based map had the highest predictive performance based on 10 bootstrapped replicate models (AUC = 0.809 ± 0.011), but the

  17. On-line leak detection method for OWL-1 loop by ARX modeling using dewpoint signals

    International Nuclear Information System (INIS)

    Oguma, Ritsuo; Hayashi, Koji; Kitajima, Toshio.

    1981-01-01

    Model identification technique based on ARX (autoregressive model with exogenous variable) process was applied to dewpoint data recorded at OWL-1 (Oarai Water Loop No. 1) loop cubicle in JMTR (Japan Materials Testing Reactor) and the dynamical interrelationship between the supply and exhaust dewpoints in the ventilation system of the cubicle was empirically determined. It was shown that the information so derived on the dewpoint dynamics can assist to enhance the sensitivity of leak detection, if it was incorporated into a leak monitoring system for the OWL-1 loop. A simple digital filter incorporating the dewpoint dynamics was designed in an attempt to develop an efficient leak monitor for the OWL-1 loop. This filter was applied to the dewpoint data recordings during an abnormal leak that had occurred at the OWL-1 loop in the 43 rd cycle of JMTR operation, which demonstrated the effectiveness of the present method for leak detection at its early stage. (author)

  18. Modeling seasonal detection patterns for burrowing owl surveys

    Science.gov (United States)

    Quresh S. Latif; Kathleen D. Fleming; Cameron Barrows; John T. Rotenberry

    2012-01-01

    To guide monitoring of burrowing owls (Athene cunicularia) in the Coachella Valley, California, USA, we analyzed survey-method-specific seasonal variation in detectability. Point-based call-broadcast surveys yielded high early season detectability that then declined through time, whereas detectability on driving surveys increased through the season. Point surveys...

  19. Meta-replication reveals nonstationarity in multi-scale habitat selection of Mexican Spotted Owl

    Science.gov (United States)

    Ho Yi Wan; Kevin McGarigal; Joseph L. Ganey; Valentin Lauret; Brad C. Timm; Samuel A. Cushman

    2017-01-01

    Anthropogenic environmental changes are leading to habitat loss and degradation, driving many species to extinction. In this context, habitat models become increasingly important for effective species management and conservation. However, most habitat studies lack replicated study areas and do not properly address the role of nonstationarity and spatial scales in...

  20. Sexual dimorphism of four owl species in South Africa | Ansara-Ross ...

    African Journals Online (AJOL)

    Owl Tyto capensis, Barn Owl T. alba, Marsh Owl Asio capensis and Spotted Eagle-Owl Bubo africanus) by examining specimens of intact owl carcasses found killed by vehicles along a national road in Gauteng province, South Africa. Females ...

  1. Transformation of standardized clinical models based on OWL technologies: from CEM to OpenEHR archetypes.

    Science.gov (United States)

    Legaz-García, María del Carmen; Menárguez-Tortosa, Marcos; Fernández-Breis, Jesualdo Tomás; Chute, Christopher G; Tao, Cui

    2015-05-01

    The semantic interoperability of electronic healthcare records (EHRs) systems is a major challenge in the medical informatics area. International initiatives pursue the use of semantically interoperable clinical models, and ontologies have frequently been used in semantic interoperability efforts. The objective of this paper is to propose a generic, ontology-based, flexible approach for supporting the automatic transformation of clinical models, which is illustrated for the transformation of Clinical Element Models (CEMs) into openEHR archetypes. Our transformation method exploits the fact that the information models of the most relevant EHR specifications are available in the Web Ontology Language (OWL). The transformation approach is based on defining mappings between those ontological structures. We propose a way in which CEM entities can be transformed into openEHR by using transformation templates and OWL as common representation formalism. The transformation architecture exploits the reasoning and inferencing capabilities of OWL technologies. We have devised a generic, flexible approach for the transformation of clinical models, implemented for the unidirectional transformation from CEM to openEHR, a series of reusable transformation templates, a proof-of-concept implementation, and a set of openEHR archetypes that validate the methodological approach. We have been able to transform CEM into archetypes in an automatic, flexible, reusable transformation approach that could be extended to other clinical model specifications. We exploit the potential of OWL technologies for supporting the transformation process. We believe that our approach could be useful for international efforts in the area of semantic interoperability of EHR systems. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Outrageous Owls

    Science.gov (United States)

    Walkup, Nancy

    2007-01-01

    The author's encounter with a live owl and her purchase of a Peruvian folk art gourd inspired a new interdisciplinary experience for the author's fourth grade students. In this article, she describes how her students explored owls through clay sculpture. (Contains 2 resources and 1 online resource.)

  3. Aerodynamic robustness in owl-inspired leading-edge serrations: a computational wind-gust model.

    Science.gov (United States)

    Rao, Chen; Liu, Hao

    2018-06-08

    Owls are a master to achieve silent flight in gliding and flapping flights under natural turbulent environments owing to their unique wing morphologies. While the leading-edge serrations are recently revealed, as a passive flow control micro-device, to play a crucial role in aerodynamic force production and sound suppression [25], the characteristics of wind-gust rejection associated with leading-edge serrations remain unclear. Here we address a large-eddy simulation (LES)-based study of aerodynamic robustness in owl-inspired leading-edge serrations, which is conducted with clean and serrated wing models through mimicking wind-gusts under a longitudinal fluctuation in free-stream inflow and a lateral fluctuation in pitch angle over a broad range of angles of attack (AoAs) over 0° ≤ Φ ≤ 20°. Our results show that the leading-edge serration-based passive flow control mechanisms associated with laminar-turbulent transition work effectively under fluctuated inflow and wing pitch, indicating that the leading-edge serrations are of potential gust fluctuation rejection or robustness in aerodynamic performance. Moreover, it is revealed that the tradeoff between turbulent flow control (i.e., aero-acoustic suppression) and force production in the serrated model holds independently to the wind-gust environments: poor at lower AoAs but capable of achieving equivalent aerodynamic performance at higher AoAs > 15o compared to the clean model. Our results reveal that the owl-inspired leading-edge serrations can be a robust micro-device for aero-acoustic control coping with unsteady and complex wind environments in biomimetic rotor designs for various fluid machineries. © 2018 IOP Publishing Ltd.

  4. Electricity spot price dynamics: Beyond financial models

    International Nuclear Information System (INIS)

    Guthrie, Graeme; Videbeck, Steen

    2007-01-01

    We reveal properties of electricity spot prices that cannot be captured by the statistical models, commonly used to model financial asset prices, that are increasingly used to model electricity prices. Using more than eight years of half-hourly spot price data from the New Zealand Electricity Market, we find that the half-hourly trading periods fall naturally into five groups corresponding to the overnight off-peak, the morning peak, daytime off-peak, evening peak, and evening off-peak. The prices in different trading periods within each group are highly correlated with each other, yet the correlations between prices in different groups are lower. Models, adopted from the modeling of security prices, that are currently applied to electricity spot prices are incapable of capturing this behavior. We use a periodic autoregression to model prices instead, showing that shocks in the peak periods are larger and less persistent than those in off-peak periods, and that they often reappear in the following peak period. In contrast, shocks in the off-peak periods are smaller, more persistent, and die out (perhaps temporarily) during the peak periods. Current approaches to modeling spot prices cannot capture this behavior either. (author)

  5. 77 FR 14036 - Draft Environmental Impact Statement for Experimental Removal of Barred Owls to Benefit...

    Science.gov (United States)

    2012-03-08

    ... whether to move forward with future management of barred owls. The action alternatives vary by the number... now outnumber spotted owls in many portions of the northern spotted owl's range (Pearson and Livezey..., p. 51; Pearson and Livezey 2003, p. 274; Courtney et al., pp. 7-27 through 7-31; Gremel 2005, pp. 9...

  6. Requirements for UML and OWL Integration Tool for User Data Consistency Modeling and Testing

    DEFF Research Database (Denmark)

    Nytun, J. P.; Jensen, Christian Søndergaard; Oleshchuk, V. A.

    2003-01-01

    The amount of data available on the Internet is continuously increasing, consequentially there is a growing need for tools that help to analyse the data. Testing of consistency among data received from different sources is made difficult by the number of different languages and schemas being used....... In this paper we analyze requirements for a tool that support integration of UML models and ontologies written in languages like the W3C Web Ontology Language (OWL). The tool can be used in the following way: after loading two legacy models into the tool, the tool user connects them by inserting modeling......, an important part of this technique is attaching of OCL expressions to special boolean class attributes that we call consistency attributes. The resulting integration model can be used for automatic consistency testing of two instances of the legacy models by automatically instantiate the whole integration...

  7. ER2OWL: Generating OWL Ontology from ER Diagram

    Science.gov (United States)

    Fahad, Muhammad

    Ontology is the fundamental part of Semantic Web. The goal of W3C is to bring the web into (its full potential) a semantic web with reusing previous systems and artifacts. Most legacy systems have been documented in structural analysis and structured design (SASD), especially in simple or Extended ER Diagram (ERD). Such systems need up-gradation to become the part of semantic web. In this paper, we present ERD to OWL-DL ontology transformation rules at concrete level. These rules facilitate an easy and understandable transformation from ERD to OWL. The set of rules for transformation is tested on a structured analysis and design example. The framework provides OWL ontology for semantic web fundamental. This framework helps software engineers in upgrading the structured analysis and design artifact ERD, to components of semantic web. Moreover our transformation tool, ER2OWL, reduces the cost and time for building OWL ontologies with the reuse of existing entity relationship models.

  8. Potential trophic cascades triggered by the barred owl range expansion

    Science.gov (United States)

    Holm, Samantha R.; Noon, Barry R.; Wiens, David; Ripple, William J.

    2016-01-01

    Recently, the barred owl (Strix varia) has expanded its range into the Pacific Northwest of the United States resulting in pronounced effects on the demography and behavior of the northern spotted owl (S. occidentalis caurina). The range expansion has brought together historically allopatric species, creating the potential for significant changes in the avian predator community with possible cascading effects on food-web dynamics. The adverse effects of the barred owl on the behavior and demography of the northern spotted owl are well-documented, but little is known about the immediate and long-term effects changes in the predator community may have on native species composition and ecosystem processes. Based on northern spotted owl and barred owl selection for diet and habitat resources, there is a potential for trophic cascades within the region's predator and prey communities, differing responses by their shared and unique prey species, and possible direct and indirect effects on ecosystem processes. We explored the possible ecological consequences of the barred owl range expansion to wildlife communities of the Pacific Northwest based on the theoretical underpinnings of predator–prey relationships, interspecific competition, intraguild predation, and potential cascading trophic interactions. Negative effects on fitness of northern spotted owls because of interspecific competition with barred owls are strong selection forces that may contribute to the regional extinction of the northern spotted owl. In addition, we posit that shared prey species and those uniquely consumed by barred owls, along with other competing native predators, may experience changes in behavior, abundance, and distribution as a result of increased rates of predation by rapidly expanding populations of barred owls.

  9. A hybrid model for electricity spot prices

    International Nuclear Information System (INIS)

    Anderson, C.L.D.

    2004-01-01

    Electricity prices were highly regulated prior to the deregulation of the electric power industry. Prices were predictable, allowing generators and wholesalers to calculate their production costs and revenues. With deregulation, electricity has become the most volatile of all commodities. Electricity must be consumed as soon as it is generated due to the inability to store it in any sufficient quantity. Economic uncertainty exists because the supply of electricity cannot shift as quickly as the demand, which is highly variable. When demand increases quickly, the price must respond. Therefore, price spikes occur that are orders of magnitude higher than the base electricity price. This paper presents a robust and realistic model for spot market electricity prices used to manage risk in volatile markets. The model is a hybrid of a top down data driven method commonly used for financial applications, and a bottom up system driven method commonly used in regulated electricity markets. The advantage of the model is that it incorporates primary system drivers and demonstrates their effects on final prices. The 4 primary modules of the model are: (1) a model for forced outages, (2) a model for maintenance outages, (3) an electrical load model, and (4) a price model which combines the results of the previous 3 models. The performance of each model was tested. The forced outage model is the first of its kind to simulate the system on an aggregate basis using Weibull distributions. The overall spot price model was calibrated to, and tested with, data from the electricity market in Pennsylvania, New Jersey and Maryland. The model performed well in simulated market prices and adapted readily to changing system conditions and new electricity markets. This study examined the pricing of derivative contracts on electrical power. It also compared a range of portfolio scenarios using a Cash Flow at Risk approach

  10. A hybrid model for electricity spot prices

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, C.L.D.

    2004-07-01

    Electricity prices were highly regulated prior to the deregulation of the electric power industry. Prices were predictable, allowing generators and wholesalers to calculate their production costs and revenues. With deregulation, electricity has become the most volatile of all commodities. Electricity must be consumed as soon as it is generated due to the inability to store it in any sufficient quantity. Economic uncertainty exists because the supply of electricity cannot shift as quickly as the demand, which is highly variable. When demand increases quickly, the price must respond. Therefore, price spikes occur that are orders of magnitude higher than the base electricity price. This paper presents a robust and realistic model for spot market electricity prices used to manage risk in volatile markets. The model is a hybrid of a top down data driven method commonly used for financial applications, and a bottom up system driven method commonly used in regulated electricity markets. The advantage of the model is that it incorporates primary system drivers and demonstrates their effects on final prices. The 4 primary modules of the model are: (1) a model for forced outages, (2) a model for maintenance outages, (3) an electrical load model, and (4) a price model which combines the results of the previous 3 models. The performance of each model was tested. The forced outage model is the first of its kind to simulate the system on an aggregate basis using Weibull distributions. The overall spot price model was calibrated to, and tested with, data from the electricity market in Pennsylvania, New Jersey and Maryland. The model performed well in simulated market prices and adapted readily to changing system conditions and new electricity markets. This study examined the pricing of derivative contracts on electrical power. It also compared a range of portfolio scenarios using a Cash Flow at Risk approach.

  11. Parameter estimation of electricity spot models from futures prices

    NARCIS (Netherlands)

    Aihara, ShinIchi; Bagchi, Arunabha; Imreizeeq, E.S.N.; Walter, E.

    We consider a slight perturbation of the Schwartz-Smith model for the electricity futures prices and the resulting modified spot model. Using the martingale property of the modified price under the risk neutral measure, we derive the arbitrage free model for the spot and futures prices. We estimate

  12. Turbulent Spot Pressure Fluctuation Wave Packet Model

    Energy Technology Data Exchange (ETDEWEB)

    Dechant, Lawrence J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    Wave packet analysis provides a connection between linear small disturbance theory and subsequent nonlinear turbulent spot flow behavior. The traditional association between linear stability analysis and nonlinear wave form is developed via the method of stationary phase whereby asymptotic (simplified) mean flow solutions are used to estimate dispersion behavior and stationary phase approximation are used to invert the associated Fourier transform. The resulting process typically requires nonlinear algebraic equations inversions that can be best performed numerically, which partially mitigates the value of the approximation as compared to a more complete, e.g. DNS or linear/nonlinear adjoint methods. To obtain a simpler, closed-form analytical result, the complete packet solution is modeled via approximate amplitude (linear convected kinematic wave initial value problem) and local sinusoidal (wave equation) expressions. Significantly, the initial value for the kinematic wave transport expression follows from a separable variable coefficient approximation to the linearized pressure fluctuation Poisson expression. The resulting amplitude solution, while approximate in nature, nonetheless, appears to mimic many of the global features, e.g. transitional flow intermittency and pressure fluctuation magnitude behavior. A low wave number wave packet models also recover meaningful auto-correlation and low frequency spectral behaviors.

  13. Space-time modeling of electricity spot prices

    DEFF Research Database (Denmark)

    Abate, Girum Dagnachew; Haldrup, Niels

    In this paper we derive a space-time model for electricity spot prices. A general spatial Durbin model that incorporates the temporal as well as spatial lags of spot prices is presented. Joint modeling of space-time effects is necessarily important when prices and loads are determined in a network...... in the spot price dynamics. Estimation of the spatial Durbin model show that the spatial lag variable is as important as the temporal lag variable in describing the spot price dynamics. We use the partial derivatives impact approach to decompose the price impacts into direct and indirect effects and we show...... that price effects transmit to neighboring markets and decline with distance. In order to examine the evolution of the spatial correlation over time, a time varying parameters spot price spatial Durbin model is estimated using recursive estimation. It is found that the spatial correlation within the Nord...

  14. Modeling deflagration waves out of hot spots

    Science.gov (United States)

    Partom, Yehuda

    2017-01-01

    It is widely accepted that shock initiation and detonation of heterogeneous explosives comes about by a two-step process known as ignition and growth. In the first step a shock sweeping through an explosive cell (control volume) creates hot spots that become ignition sites. In the second step, deflagration waves (or burn waves) propagate out of those hot spots and transform the reactant in the cell into reaction products. The macroscopic (or average) reaction rate of the reactant in the cell depends on the speed of those deflagration waves and on the average distance between neighboring hot spots. Here we simulate the propagation of deflagration waves out of hot spots on the mesoscale in axial symmetry using a 2D hydrocode, to which we add heat conduction and bulk reaction. The propagation speed of the deflagration waves may depend on both pressure and temperature. It depends on pressure for quasistatic loading near ambient temperature, and on temperature at high temperatures resulting from shock loading. From the simulation we obtain deflagration fronts emanating out of the hot spots. For 8 to 13 GPa shocks, the emanating fronts propagate as deflagration waves to consume the explosive between hot spots. For higher shock levels deflagration waves may interact with the sweeping shock to become detonation waves on the mesoscale. From the simulation results we extract average deflagration wave speeds.

  15. Modelling energy spot prices by Lévy semistationary processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Benth, Fred Espen; Veraart, Almut

    This paper introduces a new modelling framework for energy spot prices based on Lévy semistationary processes. Lévy semistationary processes are special cases of the general class of ambit processes. We provide a detailed analysis of the probabilistic properties of such models and we show how...... they are able to capture many of the stylised facts observed in energy markets. Furthermore, we derive forward prices based on our spot price model. As it turns out, many of the classical spot models can be embedded into our novel modelling framework....

  16. TEVA-SPOT-GUI - Containing Preliminary Flow Model

    Data.gov (United States)

    U.S. Environmental Protection Agency — This ZIP file contains the developmental, test version of TEVA-SPOT-GUI's Flow Model. The Flow Model is a new, event based water quality algorithm for EPANET. The...

  17. Implementing OWL Defaults

    National Research Council Canada - National Science Library

    Kolovski, Vladimir; Parsia, Bijan; Katz, Yarden

    2006-01-01

    ...) have often requested some form of non-monotonic reasoning. In this paper, we present preliminary optimizations and an implementation of a restricted version of Reiter's default logic as an extension to the description logic fragment of OWL, OWL DL...

  18. A keyword spotting model using perceptually significant energy features

    Science.gov (United States)

    Umakanthan, Padmalochini

    The task of a keyword recognition system is to detect the presence of certain words in a conversation based on the linguistic information present in human speech. Such keyword spotting systems have applications in homeland security, telephone surveillance and human-computer interfacing. General procedure of a keyword spotting system involves feature generation and matching. In this work, new set of features that are based on the psycho-acoustic masking nature of human speech are proposed. After developing these features a time aligned pattern matching process was implemented to locate the words in a set of unknown words. A word boundary detection technique based on frame classification using the nonlinear characteristics of speech is also addressed in this work. Validation of this keyword spotting model was done using widely acclaimed Cepstral features. The experimental results indicate the viability of using these perceptually significant features as an augmented feature set in keyword spotting.

  19. Models and methods for hot spot safety work

    DEFF Research Database (Denmark)

    Vistisen, Dorte

    2002-01-01

    Despite the fact that millions DKK each year are spent on improving roadsafety in Denmark, funds for traffic safety are limited. It is therefore vital to spend the resources as effectively as possible. This thesis is concerned with the area of traffic safety denoted "hot spot safety work", which...... is the task of improving road safety through alterations of the geometrical and environmental characteristics of the existing road network. The presently applied models and methods in hot spot safety work on the Danish road network were developed about two decades ago, when data was more limited and software...... and statistical methods less developed. The purpose of this thesis is to contribute to improving "State of the art" in Denmark. Basis for the systematic hot spot safety work are the models describing the variation in accident counts on the road network. In the thesis hierarchical models disaggregated on time...

  20. EXPLANATORY MODEL OF SPOT PRICE OF IRON ORE

    Directory of Open Access Journals (Sweden)

    Juan Enrique Villalva A.

    2015-11-01

    Full Text Available The objective of this study was to construct an explanatory model of the spot price of iron ore in the international market. For this, the method of multiple linear regressions was used. As a dependent variable, the spot price of iron ore (62% Fe China Tianjin port was taken, between 2010 and 2013. As independents variables were taken seven variables of international iron ore market. The resulting model includes variables: Iron ore inventory in Chinese ports, Baltic Dry Index (BDI, Iron ore exports from Brazil & Australia and Chinese Rebar Steel Price, as explanatory variables of the behavior of the spot price of iron ore in the international market. The model has an adjusted coefficient of determination R2 of 0.90, and was validated by comparing its predictions vs. known values of 2014.

  1. Modelling of a proton spot scanning system using MCNP6

    International Nuclear Information System (INIS)

    Ardenfors, O; Gudowska, I; Dasu, A; Kopeć, M

    2017-01-01

    The aim of this work was to model the characteristics of a clinical proton spot scanning beam using Monte Carlo simulations with the code MCNP6. The proton beam was defined using parameters obtained from beam commissioning at the Skandion Clinic, Uppsala, Sweden. Simulations were evaluated against measurements for proton energies between 60 and 226 MeV with regard to range in water, lateral spot sizes in air and absorbed dose depth profiles in water. The model was also used to evaluate the experimental impact of lateral signal losses in an ionization chamber through simulations using different detector radii. Simulated and measured distal ranges agreed within 0.1 mm for R 90 and R 80 , and within 0.2 mm for R 50 . The average absolute difference of all spot sizes was 0.1 mm. The average agreement of absorbed dose integrals and Bragg-peak heights was 0.9%. Lateral signal losses increased with incident proton energy with a maximum signal loss of 7% for 226 MeV protons. The good agreement between simulations and measurements supports the assumptions and parameters employed in the presented Monte Carlo model. The characteristics of the proton spot scanning beam were accurately reproduced and the model will prove useful in future studies on secondary neutrons. (paper)

  2. Modelling the benchmark spot curve for the Serbian

    Directory of Open Access Journals (Sweden)

    Drenovak Mikica

    2010-01-01

    Full Text Available The objective of this paper is to estimate Serbian benchmark spot curves using the Svensson parametric model. The main challenges that we tackle are: sparse data, different currency denominations of short and longer term maturities, and infrequent transactions in the short-term market segment vs daily traded medium and long-term market segment. We find that the model is flexible enough to account for most of the data variability. The model parameters are interpreted in economic terms.

  3. Multiresolution Network Temporal and Spatial Scheduling Model of Scenic Spot

    Directory of Open Access Journals (Sweden)

    Peng Ge

    2013-01-01

    Full Text Available Tourism is one of pillar industries of the world economy. Low-carbon tourism will be the mainstream direction of the scenic spots' development, and the ω path of low-carbon tourism development is to develop economy and protect environment simultaneously. However, as the tourists' quantity is increasing, the loads of scenic spots are out of control. And the instantaneous overload in some spots caused the image phenomenon of full capacity of the whole scenic spot. Therefore, realizing the real-time schedule becomes the primary purpose of scenic spot’s management. This paper divides the tourism distribution system into several logically related subsystems and constructs a temporal and spatial multiresolution network scheduling model according to the regularity of scenic spots’ overload phenomenon in time and space. It also defines dynamic distribution probability and equivalent dynamic demand to realize the real-time prediction. We define gravitational function between fields and takes it as the utility of schedule, after resolving the transportation model of each resolution, it achieves hierarchical balance between demand and capacity of the system. The last part of the paper analyzes the time complexity of constructing a multiresolution distribution system.

  4. Model for calculation of spot prices and uncertainties integration; Modelo de calculo de precos spot e integracao de incertezas

    Energy Technology Data Exchange (ETDEWEB)

    Saraiva, J. Tome [Instituto de Engenharia de Sistemas e Computadores (INESC), Porto (Portugal). E-mail: jsaraiva@inescn.pt

    1999-07-01

    This paper presents a model for systematic and structured impact evaluation of the uncertainties existent in the load powers, on the spot prices on the various bars of a electric power system. The application developed allows the specification of load power as inaccurate trapezoidal numbers and adopts the DC model for the representation of system exploration conditions. Considering the influence of the loss power on the formulation of a spot prices spatial distribution, the model allows the inclusion of transmission network loss estimation. The results correspond to appurtenance functions of spot prices in each barm, consisting of a discrete set of ordered pais which integrates the spot price values and the appurtenance or compatibility level, in accordance with Fuzzy Sets.

  5. Logistic quantile regression provides improved estimates for bounded avian counts: a case study of California Spotted Owl fledgling production

    Science.gov (United States)

    Brian S. Cade; Barry R. Noon; Rick D. Scherer; John J. Keane

    2017-01-01

    Counts of avian fledglings, nestlings, or clutch size that are bounded below by zero and above by some small integer form a discrete random variable distribution that is not approximated well by conventional parametric count distributions such as the Poisson or negative binomial. We developed a logistic quantile regression model to provide estimates of the empirical...

  6. The evolution of mapping habitat for northern spotted owls (Strix occidentalis caurina): A comparison of photo-interpreted, Landsat-based, and lidar-based habitat maps

    Science.gov (United States)

    Steven H. Ackers; Raymond J. Davis; Keith A. Olsen; Katie M. Dugger

    2015-01-01

    Wildlife habitat mapping has evolved at a rapid pace over the last fewdecades. Beginning with simple, often subjective, hand-drawn maps, habitat mapping now involves complex species distribution models (SDMs) using mapped predictor variables derived from remotely sensed data. For species that inhabit large geographic areas, remote sensing technology is often...

  7. A rough multi-factor model of electricity spot prices

    International Nuclear Information System (INIS)

    Bennedsen, Mikkel

    2017-01-01

    We introduce a new continuous-time mathematical model of electricity spot prices which accounts for the most important stylized facts of these time series: seasonality, spikes, stochastic volatility, and mean reversion. Empirical studies have found a possible fifth stylized fact, roughness, and our approach explicitly incorporates this into the model of the prices. Our setup generalizes the popular Ornstein–Uhlenbeck-based multi-factor framework of and allows us to perform statistical tests to distinguish between an Ornstein–Uhlenbeck-based model and a rough model. Further, through the multi-factor approach we account for seasonality and spikes before estimating – and making inference on – the degree of roughness. This is novel in the literature and we present simulation evidence showing that these precautions are crucial for accurate estimation. Lastly, we estimate our model on recent data from six European energy exchanges and find statistical evidence of roughness in five out of six markets. As an application of our model, we show how, in these five markets, a rough component improves short term forecasting of the prices. - Highlights: • Statistical modeling of electricity spot prices • Multi-factor decomposition • Roughness • Electricity price forecasting

  8. High-Density Spot Seeding for Tissue Model Formation

    Science.gov (United States)

    Marquette, Michele L. (Inventor); Sognier, Marguerite A. (Inventor)

    2016-01-01

    A model of tissue is produced by steps comprising seeding cells at a selected concentration on a support to form a cell spot, incubating the cells to allow the cells to partially attach, rinsing the cells to remove any cells that have not partially attached, adding culture medium to enable the cells to proliferate at a periphery of the cell spot and to differentiate toward a center of the cell spot, and further incubating the cells to form the tissue. The cells may be C2C12 cells or other subclones of the C2 cell line, H9c2(2-1) cells, L6 cells, L8 cells, QM7 cells, Sol8 cells, G-7 cells, G-8 cells, other myoblast cells, cells from other tissues, or stem cells. The selected concentration is in a range from about 1 x 10(exp 5) cells/ml to about 1 x 10(exp 6) cells/ml. The tissue formed may be a muscle tissue or other tissue depending on the cells seeded.

  9. The Best of All Possible Worlds: Applying the Model Driven Architecture Approach to a JC3IEDM OWL Ontology Modeled in UML

    Science.gov (United States)

    2014-06-01

    from the ODM standard. Leveraging SPARX EA’s Java application programming interface (API), the team built a tool called OWL2EA that can ingest an OWL...server MySQL creates the physical schema that enables a user to store and retrieve data conforming to the vocabulary of the JC3IEDM. 6. GENERATING AN

  10. SPOTting model parameters using a ready-made Python package

    Science.gov (United States)

    Houska, Tobias; Kraft, Philipp; Breuer, Lutz

    2015-04-01

    The selection and parameterization of reliable process descriptions in ecological modelling is driven by several uncertainties. The procedure is highly dependent on various criteria, like the used algorithm, the likelihood function selected and the definition of the prior parameter distributions. A wide variety of tools have been developed in the past decades to optimize parameters. Some of the tools are closed source. Due to this, the choice for a specific parameter estimation method is sometimes more dependent on its availability than the performance. A toolbox with a large set of methods can support users in deciding about the most suitable method. Further, it enables to test and compare different methods. We developed the SPOT (Statistical Parameter Optimization Tool), an open source python package containing a comprehensive set of modules, to analyze and optimize parameters of (environmental) models. SPOT comes along with a selected set of algorithms for parameter optimization and uncertainty analyses (Monte Carlo, MC; Latin Hypercube Sampling, LHS; Maximum Likelihood, MLE; Markov Chain Monte Carlo, MCMC; Scuffled Complex Evolution, SCE-UA; Differential Evolution Markov Chain, DE-MCZ), together with several likelihood functions (Bias, (log-) Nash-Sutcliff model efficiency, Correlation Coefficient, Coefficient of Determination, Covariance, (Decomposed-, Relative-, Root-) Mean Squared Error, Mean Absolute Error, Agreement Index) and prior distributions (Binomial, Chi-Square, Dirichlet, Exponential, Laplace, (log-, multivariate-) Normal, Pareto, Poisson, Cauchy, Uniform, Weibull) to sample from. The model-independent structure makes it suitable to analyze a wide range of applications. We apply all algorithms of the SPOT package in three different case studies. Firstly, we investigate the response of the Rosenbrock function, where the MLE algorithm shows its strengths. Secondly, we study the Griewank function, which has a challenging response surface for

  11. Identifying traffic accident black spots with Poisson-Tweedie models

    DEFF Research Database (Denmark)

    Debrabant, Birgit; Halekoh, Ulrich; Bonat, Wagner Hugo

    2018-01-01

    This paper aims at the identification of black spots for traffic accidents, i.e. locations with accident counts beyond what is usual for similar locations, using spatially and temporally aggregated hospital records from Funen, Denmark. Specifically, we apply an autoregressive Poisson-Tweedie model...... considered calendar years and calculated by simulations a probability of p=0.03 for these to be chance findings. Altogether, our results recommend these sites for further investigation and suggest that our simple approach could play a role in future area based traffic accident prevention planning....

  12. PyTranSpot: A tool for multiband light curve modeling of planetary transits and stellar spots

    Science.gov (United States)

    Juvan, Ines G.; Lendl, M.; Cubillos, P. E.; Fossati, L.; Tregloan-Reed, J.; Lammer, H.; Guenther, E. W.; Hanslmeier, A.

    2018-02-01

    Several studies have shown that stellar activity features, such as occulted and non-occulted starspots, can affect the measurement of transit parameters biasing studies of transit timing variations and transmission spectra. We present PyTranSpot, which we designed to model multiband transit light curves showing starspot anomalies, inferring both transit and spot parameters. The code follows a pixellation approach to model the star with its corresponding limb darkening, spots, and transiting planet on a two dimensional Cartesian coordinate grid. We combine PyTranSpot with a Markov chain Monte Carlo framework to study and derive exoplanet transmission spectra, which provides statistically robust values for the physical properties and uncertainties of a transiting star-planet system. We validate PyTranSpot's performance by analyzing eleven synthetic light curves of four different star-planet systems and 20 transit light curves of the well-studied WASP-41b system. We also investigate the impact of starspots on transit parameters and derive wavelength dependent transit depth values for WASP-41b covering a range of 6200-9200 Å, indicating a flat transmission spectrum.

  13. OWL: A code for the two-center shell model with spherical Woods-Saxon potentials

    Science.gov (United States)

    Diaz-Torres, Alexis

    2018-03-01

    A Fortran-90 code for solving the two-center nuclear shell model problem is presented. The model is based on two spherical Woods-Saxon potentials and the potential separable expansion method. It describes the single-particle motion in low-energy nuclear collisions, and is useful for characterizing a broad range of phenomena from fusion to nuclear molecular structures.

  14. Semantic web for the working ontologist effective modeling in RDFS and OWL

    CERN Document Server

    Allemang, Dean

    2011-01-01

    Semantic Web models and technologies provide information in machine-readable languages that enable computers to access the Web more intelligently and perform tasks automatically without the direction of users. These technologies are relatively recent and advancing rapidly, creating a set of unique challenges for those developing applications. Semantic Web for the Working Ontologist is the essential, comprehensive resource on semantic modeling, for practitioners in health care, artificial intelligence, finance, engineering, military intelligence, enterprise architecture, and more. Focused on

  15. Transition Heat Transfer Modeling Based on the Characteristics of Turbulent Spots

    Science.gov (United States)

    Simon, Fred; Boyle, Robert

    1998-01-01

    While turbulence models are being developed which show promise for simulating the transition region on a turbine blade or vane, it is believed that the best approach with the greatest potential for practical use is the use of models which incorporate the physics of turbulent spots present in the transition region. This type of modeling results in the prediction of transition region intermittency which when incorporated in turbulence models give a good to excellent prediction of the transition region heat transfer. Some models are presented which show how turbulent spot characteristics and behavior can be employed to predict the effect of pressure gradient and Mach number on the transition region. The models predict the spot formation rate which is needed, in addition to the transition onset location, in the Narasimha concentrated breakdown intermittency equation. A simplified approach is taken for modeling turbulent spot growth and interaction in the transition region which utilizes the turbulent spot variables governing transition length and spot generation rate. The models are expressed in terms of spot spreading angle, dimensionless spot velocity, dimensionless spot area, disturbance frequency and Mach number. The models are used in conjunction with a computer code to predict the effects of pressure gradient and Mach number on the transition region and compared with VKI experimental turbine data.

  16. Conceptual Model Formalization in a Semantic Interoperability Service Framework: Transforming Relational Database Schemas to OWL.

    Science.gov (United States)

    Bravo, Carlos; Suarez, Carlos; González, Carolina; López, Diego; Blobel, Bernd

    2014-01-01

    Healthcare information is distributed through multiple heterogeneous and autonomous systems. Access to, and sharing of, distributed information sources are a challenging task. To contribute to meeting this challenge, this paper presents a formal, complete and semi-automatic transformation service from Relational Databases to Web Ontology Language. The proposed service makes use of an algorithm that allows to transform several data models of different domains by deploying mainly inheritance rules. The paper emphasizes the relevance of integrating the proposed approach into an ontology-based interoperability service to achieve semantic interoperability.

  17. Spotted star light curve numerical modeling technique and its application to HII 1883 surface imaging

    Science.gov (United States)

    Kolbin, A. I.; Shimansky, V. V.

    2014-04-01

    We developed a code for imaging the surfaces of spotted stars by a set of circular spots with a uniform temperature distribution. The flux from the spotted surface is computed by partitioning the spots into elementary areas. The code takes into account the passing of spots behind the visible stellar limb, limb darkening, and overlapping of spots. Modeling of light curves includes the use of recent results of the theory of stellar atmospheres needed to take into account the temperature dependence of flux intensity and limb darkening coefficients. The search for spot parameters is based on the analysis of several light curves obtained in different photometric bands. We test our technique by applying it to HII 1883.

  18. Modeling Hot-Spot Contributions in Shocked High Explosives at the Mesoscale

    Energy Technology Data Exchange (ETDEWEB)

    Harrier, Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-12

    When looking at performance of high explosives, the defects within the explosive become very important. Plastic bonded explosives, or PBXs, contain voids of air and bonder between the particles of explosive material that aid in the ignition of the explosive. These voids collapse in high pressure shock conditions, which leads to the formation of hot spots. Hot spots are localized high temperature and high pressure regions that cause significant changes in the way the explosive material detonates. Previously hot spots have been overlooked with modeling, but now scientists are realizing their importance and new modeling systems that can accurately model hot spots are underway.

  19. Modeling of the fracture behavior of spot welds using advanced micro-mechanical damage models

    International Nuclear Information System (INIS)

    Sommer, Silke

    2010-01-01

    This paper presents the modeling of deformation and fracture behavior of resistance spot welded joints in DP600 steel sheets. Spot welding is still the most commonly used joining technique in automotive engineering. In overloading situations like crash joints are often the weakest link in a structure. For those reasons, crash simulations need reliable and applicable tools to predict the load bearing capacity of spot welded components. Two series of component tests with different spot weld diameters have shown that the diameter of the weld nugget is the main influencing factor affecting fracture mode (interfacial or pull-out fracture), load bearing capacity and energy absorption. In order to find a correlation between nugget diameter, load bearing capacity and fracture mode, the spot welds are simulated with detailed finite element models containing base metal, heat affected zone and weld metal in lap-shear loading conditions. The change in fracture mode from interfacial to pull-out or peel-out fracture with growing nugget diameter under lap-shear loading was successfully modeled using the Gologanu-Leblond model in combination with the fracture criteria of Thomason and Embury. A small nugget diameter is identified to be the main cause for interfacial fracture. In good agreement with experimental observations, the calculated pull-out fracture initiates in the base metal at the boundary to the heat affected zone.

  20. Dynamic fracture and hot-spot modeling in energetic composites

    Science.gov (United States)

    Grilli, Nicolò; Duarte, Camilo A.; Koslowski, Marisol

    2018-02-01

    Defects such as cracks, pores, and particle-matrix interface debonding affect the sensitivity of energetic materials by reducing the time-to-ignition and the threshold pressure to initiate an explosion. Frictional sliding of preexisting cracks is considered to be one of the most important causes of localized heating. Therefore, understanding the dynamic fracture of crystalline energetic materials is of extreme importance to assess the reliability and safety of polymer-bonded explosives. Phase field damage model simulations, based on the regularization of the crack surface as a diffuse delta function, are used to describe crack propagation in cyclotetramethylene-tetranitramine crystals embedded in a Sylgard matrix. A thermal transport model that includes heat generation by friction at crack interfaces is coupled to the solution of crack propagation. 2D and 3D dynamic compression simulations are performed with different boundary velocities and initial distributions of cracks and interface defects to understand their effect on crack propagation and heat generation. It is found that, at an impact velocity of 400 m/s, localized damage at the particle-binder interface is of key importance and that the sample reaches temperatures high enough to create a hot-spot that will lead to ignition. At an impact velocity of 10 m/s, preexisting cracks advanced inside the particle, but the increase of temperature will not cause ignition.

  1. Stochastic factor model for electricity spot price-the case of the Nordic market

    International Nuclear Information System (INIS)

    Vehvilaeinen, Iivo; Pyykkoenen, Tuomas

    2005-01-01

    This paper presents a stochastic factor based approach to mid-term modeling of spot prices in deregulated electricity markets. The fundamentals affecting the spot price are modeled independently and a market equilibrium model combines them to form spot price. Main advantage of the model is the transparency of the generated prices because each underlying factor and the dynamics between factors can be modeled and studied in detail. Paper shows realistic numerical examples on the forerunner Scandinavian electricity market. The model is used to price an exotic electricity derivative

  2. Stochastic factor model for electricity spot price - the case of the Nordic market

    International Nuclear Information System (INIS)

    Vehvilainen, I.; Pyykkoenen, T.

    2005-01-01

    This paper presents a stochastic factor based approach to mid-term modeling of spot prices in deregulated electricity markets. The fundamentals affecting the spot price are modeled independently and a market equilibrium model combines them to form spot price. Main advantage of the model is the transparency of the generated prices because each underlying factor and the dynamics between factors can be modeled and studied in detail. Paper shows realistic numerical examples on the forerunner Scandinavian electricity market. The model is used to price an exotic electricity derivative. (author)

  3. Transportation conformity particulate matter hot-spot air quality modeling.

    Science.gov (United States)

    2013-07-01

    In light of the new development in particulate matter (PM) hot-spot regulations and Illinois Department : of Transportation (IDOT)s National Environmental Policy Act (NEPA) documentation requirements, : this project is intended to (1) perform and ...

  4. Ductile shear failure or plug failure of spot welds modelled by modified Gurson model

    DEFF Research Database (Denmark)

    Nielsen, Kim Lau; Tvergaard, Viggo

    2010-01-01

    For resistance spot welded shear-lab specimens, interfacial failure under ductile shearing or ductile plug failure are analyzed numerically, using a shear modified Gurson model. The interfacial shear failure occurs under very low stress triaxiality, where the original Gurson model would predict...

  5. Modeling spot markets for electricity and pricing electricity derivatives

    Science.gov (United States)

    Ning, Yumei

    Spot prices for electricity have been very volatile with dramatic price spikes occurring in restructured market. The task of forecasting electricity prices and managing price risk presents a new challenge for market players. The objectives of this dissertation are: (1) to develop a stochastic model of price behavior and predict price spikes; (2) to examine the effect of weather forecasts on forecasted prices; (3) to price electricity options and value generation capacity. The volatile behavior of prices can be represented by a stochastic regime-switching model. In the model, the means of the high-price and low-price regimes and the probabilities of switching from one regime to the other are specified as functions of daily peak load. The probability of switching to the high-price regime is positively related to load, but is still not high enough at the highest loads to predict price spikes accurately. An application of this model shows how the structure of the Pennsylvania-New Jersey-Maryland market changed when market-based offers were allowed, resulting in higher price spikes. An ARIMA model including temperature, seasonal, and weekly effects is estimated to forecast daily peak load. Forecasts of load under different assumptions about weather patterns are used to predict changes of price behavior given the regime-switching model of prices. Results show that the range of temperature forecasts from a normal summer to an extremely warm summer cause relatively small increases in temperature (+1.5%) and load (+3.0%). In contrast, the increases in prices are large (+20%). The conclusion is that the seasonal outlook forecasts provided by NOAA are potentially valuable for predicting prices in electricity markets. The traditional option models, based on Geometric Brownian Motion are not appropriate for electricity prices. An option model using the regime-switching framework is developed to value a European call option. The model includes volatility risk and allows changes

  6. Development of the RETRAN hot spot model for KSNP

    International Nuclear Information System (INIS)

    Kim, Yo Han; Kim, Yong Deog; Lee, Chang Sup

    2004-01-01

    Under the funding of Ministry of Commerce, Industry and Energy, Korea Electric Power Research Institute (KEPRI), the research center of Korea Electric Power Corporation (KEPCO), has been developed the in-house non-loss-of-coolant accident (non-LOCA) analysis methodology for Korea Standard Nuclear Power Plants (KSNP). To develop the methodology, the related documents of EPRI and vendors were examined and the methodologies of some foreign utilities were reviewed also to compensate for lack of capabilities. In fact, one of the major goals of the project is to build the code and methodology systems to replace the restricted codes by U. S. Government mentioned in the Technical Transfer Agreement between KEPCO and ABB-CE. To achieve the goal, KEPRI has developed the methodology based on general-purpose system codes, such as RETRAN, RELAP and MASTER. Despite the efforts, some functional weaks were raised from the users. So, KEPRI has developed the RETRAN hot spot model (HSM) to compensate some functions used for the estimation of the fuel temperature and enthalpy, cladding surface temperature, etc. In current methodology for KSNP, the parameters are calculated with STRIKIN-II code, which is one of the restricted codes. In this paper the development of HSM is described. And to estimate the feasibility of the model, the rod ejection accident (REA) was analyzed and the results were compared with those calculated by STRIKIN-II code. Through the feasibility study, it was concluded that the developed model showed the acceptable results and could be used further works

  7. A Process for the Representation of openEHR ADL Archetypes in OWL Ontologies.

    Science.gov (United States)

    Porn, Alex Mateus; Peres, Leticia Mara; Didonet Del Fabro, Marcos

    2015-01-01

    ADL is a formal language to express archetypes, independent of standards or domain. However, its specification is not precise enough in relation to the specialization and semantic of archetypes, presenting difficulties in implementation and a few available tools. Archetypes may be implemented using other languages such as XML or OWL, increasing integration with Semantic Web tools. Exchanging and transforming data can be better implemented with semantics oriented models, for example using OWL which is a language to define and instantiate Web ontologies defined by W3C. OWL permits defining significant, detailed, precise and consistent distinctions among classes, properties and relations by the user, ensuring the consistency of knowledge than using ADL techniques. This paper presents a process of an openEHR ADL archetypes representation in OWL ontologies. This process consists of ADL archetypes conversion in OWL ontologies and validation of OWL resultant ontologies using the mutation test.

  8. THE INFORMATION CONTENT IN ANALYTIC SPOT MODELS OF BROADBAND PRECISION LIGHT CURVES

    Energy Technology Data Exchange (ETDEWEB)

    Walkowicz, Lucianne M. [Department of Astrophysical Sciences, Princeton University, Peyton Hall, 4 Ivy Lane, Princeton, NJ 08534 (United States); Basri, Gibor [Astronomy Department, University of California at Berkeley, Hearst Field Annex, Berkeley, CA 94720 (United States); Valenti, Jeff A. [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States)

    2013-04-01

    We present the results of numerical experiments to assess degeneracies in light curve models of starspots. Using synthetic light curves generated with the Cheetah starspot modeling code, we explore the extent to which photometric light curves constrain spot model parameters, including spot latitudes and stellar inclination. We also investigate the effects of spot parameters and differential rotation on one's ability to correctly recover rotation periods and differential rotation in the Kepler light curves. We confirm that in the absence of additional constraints on the stellar inclination, such as spectroscopic measurements of vsin i or occultations of starspots by planetary transits, the spot latitude and stellar inclination are difficult to determine uniquely from the photometry alone. We find that for models with no differential rotation, spots that appear on opposite hemispheres of the star may cause one to interpret the rotation period to be half of the true period. When differential rotation is included, the changing longitude separation between spots breaks the symmetry of the hemispheres and the correct rotation period is more likely to be found. The dominant period found via periodogram analysis is typically that of the largest spot. Even when multiple spots with periods representative of the star's differential rotation exist, if one spot dominates the light curve the signal of differential rotation may not be detectable from the periodogram alone. Starspot modeling is applicable to stars with a wider range of rotation rates than other surface imaging techniques (such as Doppler imaging), allows subtle signatures of differential rotation to be measured, and may provide valuable information on the distribution of stellar spots. However, given the inherent degeneracies and uncertainty present in starspot models, caution should be exercised in their interpretation.

  9. THE INFORMATION CONTENT IN ANALYTIC SPOT MODELS OF BROADBAND PRECISION LIGHT CURVES

    International Nuclear Information System (INIS)

    Walkowicz, Lucianne M.; Basri, Gibor; Valenti, Jeff A.

    2013-01-01

    We present the results of numerical experiments to assess degeneracies in light curve models of starspots. Using synthetic light curves generated with the Cheetah starspot modeling code, we explore the extent to which photometric light curves constrain spot model parameters, including spot latitudes and stellar inclination. We also investigate the effects of spot parameters and differential rotation on one's ability to correctly recover rotation periods and differential rotation in the Kepler light curves. We confirm that in the absence of additional constraints on the stellar inclination, such as spectroscopic measurements of vsin i or occultations of starspots by planetary transits, the spot latitude and stellar inclination are difficult to determine uniquely from the photometry alone. We find that for models with no differential rotation, spots that appear on opposite hemispheres of the star may cause one to interpret the rotation period to be half of the true period. When differential rotation is included, the changing longitude separation between spots breaks the symmetry of the hemispheres and the correct rotation period is more likely to be found. The dominant period found via periodogram analysis is typically that of the largest spot. Even when multiple spots with periods representative of the star's differential rotation exist, if one spot dominates the light curve the signal of differential rotation may not be detectable from the periodogram alone. Starspot modeling is applicable to stars with a wider range of rotation rates than other surface imaging techniques (such as Doppler imaging), allows subtle signatures of differential rotation to be measured, and may provide valuable information on the distribution of stellar spots. However, given the inherent degeneracies and uncertainty present in starspot models, caution should be exercised in their interpretation.

  10. A feature-based approach to modeling protein-protein interaction hot spots.

    Science.gov (United States)

    Cho, Kyu-il; Kim, Dongsup; Lee, Doheon

    2009-05-01

    Identifying features that effectively represent the energetic contribution of an individual interface residue to the interactions between proteins remains problematic. Here, we present several new features and show that they are more effective than conventional features. By combining the proposed features with conventional features, we develop a predictive model for interaction hot spots. Initially, 54 multifaceted features, composed of different levels of information including structure, sequence and molecular interaction information, are quantified. Then, to identify the best subset of features for predicting hot spots, feature selection is performed using a decision tree. Based on the selected features, a predictive model for hot spots is created using support vector machine (SVM) and tested on an independent test set. Our model shows better overall predictive accuracy than previous methods such as the alanine scanning methods Robetta and FOLDEF, and the knowledge-based method KFC. Subsequent analysis yields several findings about hot spots. As expected, hot spots have a larger relative surface area burial and are more hydrophobic than other residues. Unexpectedly, however, residue conservation displays a rather complicated tendency depending on the types of protein complexes, indicating that this feature is not good for identifying hot spots. Of the selected features, the weighted atomic packing density, relative surface area burial and weighted hydrophobicity are the top 3, with the weighted atomic packing density proving to be the most effective feature for predicting hot spots. Notably, we find that hot spots are closely related to pi-related interactions, especially pi . . . pi interactions.

  11. Charge-Spot Model for Electrostatic Forces in Simulation of Fine Particulates

    Science.gov (United States)

    Walton, Otis R.; Johnson, Scott M.

    2010-01-01

    The charge-spot technique for modeling the static electric forces acting between charged fine particles entails treating electric charges on individual particles as small sets of discrete point charges, located near their surfaces. This is in contrast to existing models, which assume a single charge per particle. The charge-spot technique more accurately describes the forces, torques, and moments that act on triboelectrically charged particles, especially image-charge forces acting near conducting surfaces. The discrete element method (DEM) simulation uses a truncation range to limit the number of near-neighbor charge spots via a shifted and truncated potential Coulomb interaction. The model can be readily adapted to account for induced dipoles in uncharged particles (and thus dielectrophoretic forces) by allowing two charge spots of opposite signs to be created in response to an external electric field. To account for virtual overlap during contacts, the model can be set to automatically scale down the effective charge in proportion to the amount of virtual overlap of the charge spots. This can be accomplished by mimicking the behavior of two real overlapping spherical charge clouds, or with other approximate forms. The charge-spot method much more closely resembles real non-uniform surface charge distributions that result from tribocharging than simpler approaches, which just assign a single total charge to a particle. With the charge-spot model, a single particle may have a zero net charge, but still have both positive and negative charge spots, which could produce substantial forces on the particle when it is close to other charges, when it is in an external electric field, or when near a conducting surface. Since the charge-spot model can contain any number of charges per particle, can be used with only one or two charge spots per particle for simulating charging from solar wind bombardment, or with several charge spots for simulating triboelectric charging

  12. Spot counting on fluorescence in situ hybridization in suspension images using Gaussian mixture model

    Science.gov (United States)

    Liu, Sijia; Sa, Ruhan; Maguire, Orla; Minderman, Hans; Chaudhary, Vipin

    2015-03-01

    Cytogenetic abnormalities are important diagnostic and prognostic criteria for acute myeloid leukemia (AML). A flow cytometry-based imaging approach for FISH in suspension (FISH-IS) was established that enables the automated analysis of several log-magnitude higher number of cells compared to the microscopy-based approaches. The rotational positioning can occur leading to discordance between spot count. As a solution of counting error from overlapping spots, in this study, a Gaussian Mixture Model based classification method is proposed. The Akaike information criterion (AIC) and Bayesian information criterion (BIC) of GMM are used as global image features of this classification method. Via Random Forest classifier, the result shows that the proposed method is able to detect closely overlapping spots which cannot be separated by existing image segmentation based spot detection methods. The experiment results show that by the proposed method we can obtain a significant improvement in spot counting accuracy.

  13. Enhancing the ifcOWL ontology with an alternative representation for geometric data

    NARCIS (Netherlands)

    Pauwels, P.; Krijnen, T.; Terkaj, W.; Beetz, J.

    2017-01-01

    Over the past few years, several suggestions have been made of how to convert an EXPRESS schema into an OWL ontology. The conversion from EXPRESS to OWL is of particular use to the architectural design and construction industry, because one of the key data models in this domain, namely the Industry

  14. Burrowing Owls, Pulex irritans, and Plague.

    Science.gov (United States)

    Belthoff, James R; Bernhardt, Scott A; Ball, Christopher L; Gregg, Michael; Johnson, David H; Ketterling, Rachel; Price, Emily; Tinker, Juliette K

    2015-09-01

    Western Burrowing Owls (Athene cunicularia hypugaea) are small, ground-dwelling owls of western North America that frequent prairie dog (Cynomys spp.) towns and other grasslands. Because they rely on rodent prey and occupy burrows once or concurrently inhabited by fossorial mammals, the owls often harbor fleas. We examined the potential role of fleas found on burrowing owls in plague dynamics by evaluating prevalence of Yersinia pestis in fleas collected from burrowing owls and in owl blood. During 2012-2013, fleas and blood were collected from burrowing owls in portions of five states with endemic plague-Idaho, Oregon, Washington, Colorado, and South Dakota. Fleas were enumerated, taxonomically identified, pooled by nest, and assayed for Y. pestis using culturing and molecular (PCR) approaches. Owl blood underwent serological analysis for plague antibodies and nested PCR for detection of Y. pestis. Of more than 4750 fleas collected from owls, Pulex irritans, a known plague vector in portions of its range, comprised more than 99.4%. However, diagnostic tests for Y. pestis of flea pools (culturing and PCR) and owl blood (PCR and serology) were negative. Thus, even though fleas were prevalent on burrowing owls and the potential for a relationship with burrowing owls as a phoretic host of infected fleas exists, we found no evidence of Y. pestis in sampled fleas or in owls that harbored them. We suggest that studies similar to those reported here during plague epizootics will be especially useful for confirming these results.

  15. Forecasting electricity spot-prices using linear univariate time-series models

    International Nuclear Information System (INIS)

    Cuaresma, Jesus Crespo; Hlouskova, Jaroslava; Kossmeier, Stephan; Obersteiner, Michael

    2004-01-01

    This paper studies the forecasting abilities of a battery of univariate models on hourly electricity spot prices, using data from the Leipzig Power Exchange. The specifications studied include autoregressive models, autoregressive-moving average models and unobserved component models. The results show that specifications, where each hour of the day is modelled separately present uniformly better forecasting properties than specifications for the whole time-series, and that the inclusion of simple probabilistic processes for the arrival of extreme price events can lead to improvements in the forecasting abilities of univariate models for electricity spot prices. (Author)

  16. Albinism in the Great Gray Owl (Strix nebulosa) and other owls

    Science.gov (United States)

    Pentti Alaja; Heimo Mikkola

    1997-01-01

    An incomplete albino Great Gray Owl (Strix nebulosa) was observed in Vesanto and Kajaani, Finland, 1994-1995. The literature pertaining to albinism in owls indicates that total and incomplete albinism has only been reported in 13 different owl species, the Great Gray Owl being the only species with more than five records. Thus six to seven incomplete...

  17. Modeling characterization of the National Ignition Facility focal spot

    International Nuclear Information System (INIS)

    Williams, W.H.

    1998-01-01

    The predicted focal spot size of the National Ignition Facility laser is parameterized against the finish quality of the optics in the system. Results are reported from simulations which include static optics aberrations, as well as pump-induced distortions, beam self-focusing, and the effect of an adaptive optic. The simulations do not include contributions from optics mounting errors, residual thermal noise in laser slabs from previous shots, air turbulence, a kinoform phase plate, or smoothing by spectral dispersion (SSD). Consequently, these results represent ''first shot of the day'', without-SSD, predictions

  18. Breakdown of hot-spot model in determining convective amplification in large homogeneous systems

    International Nuclear Information System (INIS)

    Mounaix, Philippe; Divol, Laurent

    2004-01-01

    Convective amplification in large homogeneous systems is studied, both analytically and numerically, in the case of a linear diffraction-free stochastic amplifier. Overall amplification does not result from successive amplifications in small scale high intensity hot spots, but from a single amplification in a delocalized mode of the driver field spreading over the whole interaction length. For this model, the hot-spot approach is found to systematically underestimate the gain factor by more than 50%

  19. A feature-based approach to modeling protein–protein interaction hot spots

    Science.gov (United States)

    Cho, Kyu-il; Kim, Dongsup; Lee, Doheon

    2009-01-01

    Identifying features that effectively represent the energetic contribution of an individual interface residue to the interactions between proteins remains problematic. Here, we present several new features and show that they are more effective than conventional features. By combining the proposed features with conventional features, we develop a predictive model for interaction hot spots. Initially, 54 multifaceted features, composed of different levels of information including structure, sequence and molecular interaction information, are quantified. Then, to identify the best subset of features for predicting hot spots, feature selection is performed using a decision tree. Based on the selected features, a predictive model for hot spots is created using support vector machine (SVM) and tested on an independent test set. Our model shows better overall predictive accuracy than previous methods such as the alanine scanning methods Robetta and FOLDEF, and the knowledge-based method KFC. Subsequent analysis yields several findings about hot spots. As expected, hot spots have a larger relative surface area burial and are more hydrophobic than other residues. Unexpectedly, however, residue conservation displays a rather complicated tendency depending on the types of protein complexes, indicating that this feature is not good for identifying hot spots. Of the selected features, the weighted atomic packing density, relative surface area burial and weighted hydrophobicity are the top 3, with the weighted atomic packing density proving to be the most effective feature for predicting hot spots. Notably, we find that hot spots are closely related to π–related interactions, especially π · · · π interactions. PMID:19273533

  20. On a new Owl from Liberia

    NARCIS (Netherlands)

    Büttikofer, J.

    1889-01-01

    Amongst the last birds received from Mr. Stampfli, there was a very peculiar new Owl, which I propose to name Bubo lettii, after its discoverer Mr. Lett, our former landlord and huntsman at Schieffelinsville. This Owl shows no affinity to any of the Owls at present known from the old world, but

  1. Chapter 17. Information needs: Great gray owls

    Science.gov (United States)

    Gregory D. Hayward

    1994-01-01

    Current understanding of great gray owl biology and ecology is based on studies of less than five populations. In an ideal world, a strong conservation strategy would require significant new information. However, current knowledge suggests that conservation of this forest owl should involve fewer conflicts than either the boreal or flammulated owl. The mix of forest...

  2. The choice between cooled tubular reactor models: analysis of the hot spot

    NARCIS (Netherlands)

    Westerink, E.J.; Koster, N.; Westerterp, K.R.

    1990-01-01

    The applicability of the one-dimensional pseudo-homogeneous model of the cooled tubular reactor is studied. Using the two-dimensional model as the more accurate one we compared both models by studying the influence of the design and operating variables on the conditions in the hot spot of the

  3. Probabilistic modelling of the high-pressure arc cathode spot displacement dynamic

    International Nuclear Information System (INIS)

    Coulombe, Sylvain

    2003-01-01

    A probabilistic modelling approach for the study of the cathode spot displacement dynamic in high-pressure arc systems is developed in an attempt to interpret the observed voltage fluctuations. The general framework of the model allows to define simple, probabilistic displacement rules, the so-called cathode spot dynamic rules, for various possible surface states (un-arced metal, arced, contaminated) and to study the resulting dynamic of the cathode spot displacements over one or several arc passages. The displacements of the type-A cathode spot (macro-spot) in a magnetically rotating arc using concentric electrodes made up of either clean or contaminated metal surfaces is considered. Experimental observations for this system revealed a 1/f -tilde1 signature in the frequency power spectrum (FPS) of the arc voltage for anchoring arc conditions on the cathode (e.g. clean metal surface), while it shows a 'white noise' signature for conditions favouring a smooth movement (e.g. oxide-contaminated cathode surface). Through an appropriate choice of the local probabilistic displacement rules, the model is able to correctly represent the dynamic behaviours of the type-A cathode spot, including the FPS for the arc elongation (i.e. voltage) and the arc erosion trace formation. The model illustrates that the cathode spot displacements between re-strikes can be seen as a diffusion process with a diffusion constant which depends on the surface structure. A physical interpretation for the jumping probability associated with the re-strike event is given in terms of the electron emission processes across dielectric contaminants present on the cathode surface

  4. Insights from ecological niche modeling on the taxonomic distinction and niche differentiation between the black-spotted and red-spotted tokay geckoes (Gekko gecko).

    Science.gov (United States)

    Zhang, Yueyun; Chen, Chongtao; Li, Li; Zhao, Chengjian; Chen, Weicai; Huang, Yong

    2014-09-01

    The black-spotted tokay and the red-spotted tokay are morphologically distinct and have largely allopatric distributions. The black-spotted tokay is characterized by a small body size and dark skin with sundry spots, while the red-spotted tokay has a relatively large body size and red spots. Based on morphological, karyotypic, genetic, and distribution differences, recent studies suggested their species status; however, their classifications remain controversial, and additional data such as ecological niches are necessary to establish firm hypotheses regarding their taxonomic status. We reconstructed their ecological niches models using climatic and geographic data. We then performed niche similarity tests (niche identity and background tests) and point-based analyses to explore whether ecological differentiation has occurred, and whether such differences are sufficient to explain the maintenance of their separate segments of environmental ranges. We found that both niche models of the black- and the red-spotted tokay had a good fit and a robust performance, as indicated by the high area under the curve (AUC) values ("black" = 0.982, SD = ± 0.002, "red" = 0.966 ± 0.02). Significant ecological differentiation across the entire geographic range was found, indicating that the involvement of ecological differentiation is important for species differentiation. Divergence along the environmental axes is highly associated with climatic conditions, with isothermality being important for the "black" form, while temperature seasonality, precipitation of warmest quarter, and annual temperature range together being important for the "red" form. These factors are likely important factors in niche differentiation between the two forms, which result in morphological replacement. Overall, beside morphological and genetic differentiation information, our results contribute to additional insights into taxonomic distinction and niche differentiation between the black- and the red-spotted

  5. Robust model-based analysis of single-particle tracking experiments with Spot-On

    Science.gov (United States)

    Grimm, Jonathan B; Lavis, Luke D

    2018-01-01

    Single-particle tracking (SPT) has become an important method to bridge biochemistry and cell biology since it allows direct observation of protein binding and diffusion dynamics in live cells. However, accurately inferring information from SPT studies is challenging due to biases in both data analysis and experimental design. To address analysis bias, we introduce ‘Spot-On’, an intuitive web-interface. Spot-On implements a kinetic modeling framework that accounts for known biases, including molecules moving out-of-focus, and robustly infers diffusion constants and subpopulations from pooled single-molecule trajectories. To minimize inherent experimental biases, we implement and validate stroboscopic photo-activation SPT (spaSPT), which minimizes motion-blur bias and tracking errors. We validate Spot-On using experimentally realistic simulations and show that Spot-On outperforms other methods. We then apply Spot-On to spaSPT data from live mammalian cells spanning a wide range of nuclear dynamics and demonstrate that Spot-On consistently and robustly infers subpopulation fractions and diffusion constants. PMID:29300163

  6. Cross: an OWL wrapper for teasoning on relational databases

    NARCIS (Netherlands)

    Champin, P.A.; Houben, G.J.P.M.; Thiran, Ph.; Parent, C.; Schewe, K.D.; Storey, V.C.; Thalheim, B.

    2007-01-01

    One of the challenges of the Semantic Web is to integrate the huge amount of information already available on the standard Web, usually stored in relational databases. In this paper, we propose a formalization of a logic model of relational databases, and a transformation of that model into OWL, a

  7. A model-based approach to preplanting risk assessment for gray leaf spot of maize.

    Science.gov (United States)

    Paul, P A; Munkvold, G P

    2004-12-01

    ABSTRACT Risk assessment models for gray leaf spot of maize, caused by Cercospora zeae-maydis, were developed using preplanting site and maize genotype data as predictors. Disease severity at the dough/dent plant growth stage was categorized into classes and used as the response variable. Logistic regression and classification and regression tree (CART) modeling approaches were used to predict severity classes as a function of planting date (PD), amount of maize soil surface residue (SR), cropping sequence, genotype maturity and gray leaf spot resistance (GLSR) ratings, and longitude (LON). Models were development using 332 cases collected between 1998 and 2001. Thirty cases collected in 2002 were used to validate the models. Preplanting data showed a strong relationship with late-season gray leaf spot severity classes. The most important predictors were SR, PD, GLSR, and LON. Logistic regression models correctly classified 60 to 70% of the validation cases, whereas the CART models correctly classified 57 to 77% of these cases. Cases misclassified by the CART models were mostly due to overestimation, whereas the logistic regression models tended to misclassify cases by underestimation. Both the CART and logistic regression models have potential as management decision-making tools. Early quantitative assessment of gray leaf spot risk would allow for more sound management decisions being made when warranted.

  8. Validity of urinary monoamine assay sales under the "spot baseline urinary neurotransmitter testing marketing model".

    Science.gov (United States)

    Hinz, Marty; Stein, Alvin; Uncini, Thomas

    2011-01-01

    Spot baseline urinary monoamine assays have been used in medicine for over 50 years as a screening test for monoamine-secreting tumors, such as pheochromocytoma and carcinoid syndrome. In these disease states, when the result of a spot baseline monoamine assay is above the specific value set by the laboratory, it is an indication to obtain a 24-hour urine sample to make a definitive diagnosis. There are no defined applications where spot baseline urinary monoamine assays can be used to diagnose disease or other states directly. No peer-reviewed published original research exists which demonstrates that these assays are valid in the treatment of individual patients in the clinical setting. Since 2001, urinary monoamine assay sales have been promoted for numerous applications under the "spot baseline urinary neurotransmitter testing marketing model". There is no published peer-reviewed original research that defines the scientific foundation upon which the claims for these assays are made. On the contrary, several articles have been published that discredit various aspects of the model. To fill the void, this manuscript is a comprehensive review of the scientific foundation and claims put forth by laboratories selling urinary monoamine assays under the spot baseline urinary neurotransmitter testing marketing model.

  9. Periodic Seasonal Reg-ARFIMA-GARCH Models for Daily Electricity Spot Prices

    NARCIS (Netherlands)

    Ooms, M.; Koopman, S.J.; Carnero, A.M.

    2007-01-01

    Novel periodic extensions of dynamic long-memory regression models with autoregressive conditional heteroscedastic errors are considered for the analysis of daily electricity spot prices. The parameters of the model with mean and variance specifications are estimated simultaneously by the method of

  10. Prediction of hot spots in protein interfaces using a random forest model with hybrid features.

    Science.gov (United States)

    Wang, Lin; Liu, Zhi-Ping; Zhang, Xiang-Sun; Chen, Luonan

    2012-03-01

    Prediction of hot spots in protein interfaces provides crucial information for the research on protein-protein interaction and drug design. Existing machine learning methods generally judge whether a given residue is likely to be a hot spot by extracting features only from the target residue. However, hot spots usually form a small cluster of residues which are tightly packed together at the center of protein interface. With this in mind, we present a novel method to extract hybrid features which incorporate a wide range of information of the target residue and its spatially neighboring residues, i.e. the nearest contact residue in the other face (mirror-contact residue) and the nearest contact residue in the same face (intra-contact residue). We provide a novel random forest (RF) model to effectively integrate these hybrid features for predicting hot spots in protein interfaces. Our method can achieve accuracy (ACC) of 82.4% and Matthew's correlation coefficient (MCC) of 0.482 in Alanine Scanning Energetics Database, and ACC of 77.6% and MCC of 0.429 in Binding Interface Database. In a comparison study, performance of our RF model exceeds other existing methods, such as Robetta, FOLDEF, KFC, KFC2, MINERVA and HotPoint. Of our hybrid features, three physicochemical features of target residues (mass, polarizability and isoelectric point), the relative side-chain accessible surface area and the average depth index of mirror-contact residues are found to be the main discriminative features in hot spots prediction. We also confirm that hot spots tend to form large contact surface areas between two interacting proteins. Source data and code are available at: http://www.aporc.org/doc/wiki/HotSpot.

  11. Research on spot power market equilibrium model considering the electric power network characteristics

    International Nuclear Information System (INIS)

    Wang, Chengmin; Jiang, Chuanwen; Chen, Qiming

    2007-01-01

    Equilibrium is the optimum operational condition for the power market by economics rule. A realistic spot power market cannot achieve the equilibrium condition due to network losses and congestions. The impact of the network losses and congestion on spot power market is analyzed in this paper in order to establish a new equilibrium model considering the network loss and transmission constraints. The OPF problem formulated according to the new equilibrium model is solved by means of the equal price principle. A case study on the IEEE-30-bus system is provided in order to prove the effectiveness of the proposed approach. (author)

  12. A Monte Carlo model for mean glandular dose evaluation in spot compression mammography.

    Science.gov (United States)

    Sarno, Antonio; Dance, David R; van Engen, Ruben E; Young, Kenneth C; Russo, Paolo; Di Lillo, Francesca; Mettivier, Giovanni; Bliznakova, Kristina; Fei, Baowei; Sechopoulos, Ioannis

    2017-07-01

    To characterize the dependence of normalized glandular dose (DgN) on various breast model and image acquisition parameters during spot compression mammography and other partial breast irradiation conditions, and evaluate alternative previously proposed dose-related metrics for this breast imaging modality. Using Monte Carlo simulations with both simple homogeneous breast models and patient-specific breasts, three different dose-related metrics for spot compression mammography were compared: the standard DgN, the normalized glandular dose to only the directly irradiated portion of the breast (DgNv), and the DgN obtained by the product of the DgN for full field irradiation and the ratio of the mid-height area of the irradiated breast to the entire breast area (DgN M ). How these metrics vary with field-of-view size, spot area thickness, x-ray energy, spot area and position, breast shape and size, and system geometry was characterized for the simple breast model and a comparison of the simple model results to those with patient-specific breasts was also performed. The DgN in spot compression mammography can vary considerably with breast area. However, the difference in breast thickness between the spot compressed area and the uncompressed area does not introduce a variation in DgN. As long as the spot compressed area is completely within the breast area and only the compressed breast portion is directly irradiated, its position and size does not introduce a variation in DgN for the homogeneous breast model. As expected, DgN is lower than DgNv for all partial breast irradiation areas, especially when considering spot compression areas within the clinically used range. DgN M underestimates DgN by 6.7% for a W/Rh spectrum at 28 kVp and for a 9 × 9 cm 2 compression paddle. As part of the development of a new breast dosimetry model, a task undertaken by the American Association of Physicists in Medicine and the European Federation of Organizations of Medical Physics

  13. Probabilistic modelling of the high-pressure arc cathode spot displacement dynamic

    CERN Document Server

    Coulombe, S

    2003-01-01

    A probabilistic modelling approach for the study of the cathode spot displacement dynamic in high-pressure arc systems is developed in an attempt to interpret the observed voltage fluctuations. The general framework of the model allows to define simple, probabilistic displacement rules, the so-called cathode spot dynamic rules, for various possible surface states (un-arced metal, arced, contaminated) and to study the resulting dynamic of the cathode spot displacements over one or several arc passages. The displacements of the type-A cathode spot (macro-spot) in a magnetically rotating arc using concentric electrodes made up of either clean or contaminated metal surfaces is considered. Experimental observations for this system revealed a 1/f sup - sup t sup i sup l sup d sup e sup 1 signature in the frequency power spectrum (FPS) of the arc voltage for anchoring arc conditions on the cathode (e.g. clean metal surface), while it shows a 'white noise' signature for conditions favouring a smooth movement (e.g. ox...

  14. Gravity model improvement using the DORIS tracking system on the SPOT 2 satellite

    Science.gov (United States)

    Nerem, R. S.; Lerch, F. J.; Williamson, R. G.; Klosko, S. M.; Robbins, J. W.; Patel, G. B.

    1994-01-01

    A high-precision radiometric satellite tracking system, Doppler Orbitography and Radio-positioning Integrated by Satellite system (DORIS), has recently been developed by the French space agency, Centre National d'Etudes Spatiales (CNES). DORIS was designed to provide tracking support for missions such as the joint United States/French TOPEX/Poseidon. As part of the flight testing process, a DORIS package was flown on the French SPOT 2 satellite. A substantial quantity of geodetic quality tracking data was obtained on SPOT 2 from an extensive international DORIS tracking network. These data were analyzed to assess their accuracy and to evaluate the gravitational modeling enhancements provided by these data in combination with the Goddard Earth Model-T3 (GEM-T3) gravitational model. These observations have noise levels of 0.4 to 0.5 mm/s, with few residual systematic effects. Although the SPOT 2 satellite experiences high atmospheric drag forces, the precision and global coverage of the DORIS tracking data have enabled more extensive orbit parameterization to mitigate these effects. As a result, the SPOT 2 orbital errors have been reduced to an estimated radial accuracy in the 10-20 cm RMS range. The addition of these data, which encompass many regions heretofore lacking in precision satellite tracking, has significantly improved GEM-T3 and allowed greatly improved orbit accuracies for Sun-synchronous satellites like SPOT 2 (such as ERS 1 and EOS). Comparison of the ensuing gravity model with other contemporary fields (GRIM-4C2, TEG2B, and OSU91A) provides a means to assess the current state of knowledge of the Earth's gravity field. Thus, the DORIS experiment on SPOT 2 has provided a strong basis for evaluating this new orbit tracking technology and has demonstrated the important contribution of the DORIS network to the success of the TOPEX/Poseidon mission.

  15. 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).

  16. HMM filtering and parameter estimation of an electricity spot price model

    International Nuclear Information System (INIS)

    Erlwein, Christina; Benth, Fred Espen; Mamon, Rogemar

    2010-01-01

    In this paper we develop a model for electricity spot price dynamics. The spot price is assumed to follow an exponential Ornstein-Uhlenbeck (OU) process with an added compound Poisson process. In this way, the model allows for mean-reversion and possible jumps. All parameters are modulated by a hidden Markov chain in discrete time. They are able to switch between different economic regimes representing the interaction of various factors. Through the application of reference probability technique, adaptive filters are derived, which in turn, provide optimal estimates for the state of the Markov chain and related quantities of the observation process. The EM algorithm is applied to find optimal estimates of the model parameters in terms of the recursive filters. We implement this self-calibrating model on a deseasonalised series of daily spot electricity prices from the Nordic exchange Nord Pool. On the basis of one-step ahead forecasts, we found that the model is able to capture the empirical characteristics of Nord Pool spot prices. (author)

  17. Analysis of Sensitivity and Uncertainty in an Individual-Based Model of a Threatened Wildlife Species

    Science.gov (United States)

    We present a multi-faceted sensitivity analysis of a spatially explicit, individual-based model (IBM) (HexSim) of a threatened species, the Northern Spotted Owl (Strix occidentalis caurina) on a national forest in Washington, USA. Few sensitivity analyses have been conducted on ...

  18. Finite Element Method Based Modeling of Resistance Spot-Welded Mild Steel

    Directory of Open Access Journals (Sweden)

    Miloud Zaoui

    Full Text Available Abstract This paper deals with Finite Element refined and simplified models of a mild steel spot-welded specimen, developed and validated based on quasi-static cross-tensile experimental tests. The first model was constructed with a fine discretization of the metal sheet and the spot weld was defined as a special geometric zone of the specimen. This model provided, in combination with experimental tests, the input data for the development of the second model, which was constructed with respect to the mesh size used in the complete car finite element model. This simplified model was developed with coarse shell elements and a spring-type beam element was used to model the spot weld behavior. The global accuracy of the two models was checked by comparing simulated and experimental load-displacement curves and by studying the specimen deformed shapes and the plastic deformation growth in the metal sheets. The obtained results show that both fine and coarse finite element models permit a good prediction of the experimental tests.

  19. Analysis and Modelling of Electrode Wear in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Madsen, Anders; Pedersen, Kim; Friis, Kasper Storgaard

    2010-01-01

    A model describing electrode wear as a function of weld number, initial tip diameter, truncated cone angle, welding current and electrode force is proposed. Excellent agreement between the model and experimental results is achieved, showing that the model can describe the change in electrode tip...... diameter with increasing weld number at different weld settings. Furthermore a method for measuring the worn tip diameter in a fast and robust manner is developed. The method relies on a well-known technique for capturing the electrode tip area by the use of carbon imprints and a new developed image...... a central cavity is formed and one where smaller pits are formed randomly across the electrode face. The influence of these two types of surface pits on the nugget size are investigated using the FE code SORPAS, revealing ring welds and undersized weld nuggets....

  20. Physicists spot a wobble in the subatomic model

    CERN Multimedia

    Glanz, J

    2001-01-01

    In an experiment where muons were injected into a powerful magnetic field at the Alternating Gradient Synchrotron, the measurements differ from those predicted by the Standard Model. The results are a possible confirmation of the alternative theory of supersymmetry (1 page).

  1. SPOTting Model Parameters Using a Ready-Made Python Package.

    Directory of Open Access Journals (Sweden)

    Tobias Houska

    Full Text Available The choice for specific parameter estimation methods is often more dependent on its availability than its performance. We developed SPOTPY (Statistical Parameter Optimization Tool, an open source python package containing a comprehensive set of methods typically used to calibrate, analyze and optimize parameters for a wide range of ecological models. SPOTPY currently contains eight widely used algorithms, 11 objective functions, and can sample from eight parameter distributions. SPOTPY has a model-independent structure and can be run in parallel from the workstation to large computation clusters using the Message Passing Interface (MPI. We tested SPOTPY in five different case studies to parameterize the Rosenbrock, Griewank and Ackley functions, a one-dimensional physically based soil moisture routine, where we searched for parameters of the van Genuchten-Mualem function and a calibration of a biogeochemistry model with different objective functions. The case studies reveal that the implemented SPOTPY methods can be used for any model with just a minimal amount of code for maximal power of parameter optimization. They further show the benefit of having one package at hand that includes number of well performing parameter search methods, since not every case study can be solved sufficiently with every algorithm or every objective function.

  2. Active estimation of motivational spots for modeling dynamic interactions

    NARCIS (Netherlands)

    Olier Jauregui, J.S.; Campo, D.; Marcenaro, L.; Barakova, E.I.; Rauterberg, G.W.M.; Regazzoni, C.

    2017-01-01

    To understand the behavior of moving entities in a given environment, one should be capable of predicting their motion, that is, to model their dynamics. In a setting where different behaviors can arise, one can assume that each of them corresponds to different motivational states of observed

  3. Experiences with Aber-OWL, an Ontology Repository with OWL EL Reasoning

    KAUST Repository

    Slater, Luke; Rodriguez-Garcia, Miguel Angel; O’ Shea, Keiron; Schofield, Paul N.; Gkoutos, Georgios V.; Hoehndorf, Robert

    2016-01-01

    expressed in the Web Ontology Language (OWL). Computational access to the knowledge contained within them relies on the use of automated reasoning. We have developed Aber-OWL, an ontology repository that provides OWL EL reasoning to answer queries and verify

  4. Liver spots

    Science.gov (United States)

    ... skin changes - liver spots; Senile or solar lentigines; Skin spots - aging; Age spots ... Liver spots are changes in skin color that occur in older skin. The coloring may be due to aging, exposure to the sun ...

  5. tOWL: a temporal Web Ontology Language.

    Science.gov (United States)

    Milea, Viorel; Frasincar, Flavius; Kaymak, Uzay

    2012-02-01

    Through its interoperability and reasoning capabilities, the Semantic Web opens a realm of possibilities for developing intelligent systems on the Web. The Web Ontology Language (OWL) is the most expressive standard language for modeling ontologies, the cornerstone of the Semantic Web. However, up until now, no standard way of expressing time and time-dependent information in OWL has been provided. In this paper, we present a temporal extension of the very expressive fragment SHIN(D) of the OWL Description Logic language, resulting in the temporal OWL language. Through a layered approach, we introduce three extensions: 1) concrete domains, which allow the representation of restrictions using concrete domain binary predicates; 2) temporal representation , which introduces time points, relations between time points, intervals, and Allen's 13 interval relations into the language; and 3) timeslices/fluents, which implement a perdurantist view on individuals and allow for the representation of complex temporal aspects, such as process state transitions. We illustrate the expressiveness of the newly introduced language by using an example from the financial domain.

  6. Time-series photometric spot modeling. 2: Fifteen years of photometry of the bright RS CVn binary HR 7275

    Science.gov (United States)

    Strassmeier, K. G.; Hall, D. S.; Henry, G. W.

    1994-01-01

    We present a time-dependent spot modeling analysis of 15 consecutive years of V-band photometry of the long-period (P(sub orb) = 28.6 days) RS CVn binary HR 7275. This baseline in time is one of the longest, uninterrupted intervals a spotted star has been observed. The spot modeling analysis yields a total of 20 different spots throughout the time span of our observations. The distribution of the observed spot migration rates is consistent with solar-type differential rotation and suggests a lower limit of the differential-rotation coefficient of 0.022 +/-0.004. The observed, maximum lifetime of a single spot (or spot group) is 4.5 years, the minimum lifetime is approximately one year, but an average spot lives for 2.2 years. If we assume that the mechanical shear by differential rotation sets the upper limit to the spot lifetime, the observed maximum lifetime in turn sets an upper limit to the differential-rotation coefficient, namely 0.04 +/- 0.01. This would be differential rotation just 5 to 8 times less than the solar value and one of the strongest among active binaries. We found no conclusive evidence for the existence of a periodic phenomenon that could be attributed to a stellar magnetic cycle.

  7. Secondary poisoning of owls by anticoagulant rodenticides

    Science.gov (United States)

    Mendenhall, Vivian M.; Pank, L.F.

    1980-01-01

    Anticoagulants-compounds that prevent clotting of the blood-are extensively used for control of small mammal pests. The potential secondary hazards of 6 anticoagulant rodenticides to birds of prey were examined in this study. Whole rats or mice were killed with each anticoagulant and were fed to 1-3 species of owls. Owls died of hemorrhaging after feeding on rats killed with bromadiolone, brodifacoum, or diphacinone; sublethal hemorrhaging occurred in owls fed rats killed with difenacoum. These results demonstrate potential secondary hazards of 4 anticoagulants to avian predators. No abnormalities were observed in owls fed rats killed with fumarin and chlorophacinone

  8. Importance of agricultural landscapes to nesting burrowing owls in the Northern Great Plains, USA

    Science.gov (United States)

    Restani, M.; Davies, J.M.; Newton, W.E.

    2008-01-01

    Anthropogenic habitat loss and fragmentation are the principle factors causing declines of grassland birds. Declines in burrowing owl (Athene cunicularia) populations have been extensive and have been linked to habitat loss, primarily the decline of black-tailed prairie dog (Cynomys ludovicianus) colonies. Development of habitat use models is a research priority and will aid conservation of owls inhabiting human-altered landscapes. From 2001 to 2004 we located 160 burrowing owl nests on prairie dog colonies on the Little Missouri National Grassland in North Dakota. We used multiple linear regression and Akaike's Information Criterion to estimate the relationship between cover type characteristics surrounding prairie dog colonies and (1) number of owl pairs per colony and (2) reproductive success. Models were developed for two spatial scales, within 600 m and 2,000 m radii of nests for cropland, crested wheatgrass (Agropyron cristatum), grassland, and prairie dog colonies. We also included number of patches as a metric of landscape fragmentation. Annually, fewer than 30% of prairie dog colonies were occupied by owls. None of the models at the 600 m scale explained variation in number of owl pairs or reproductive success. However, models at the 2,000 m scale did explain number of owl pairs and reproductive success. Models included cropland, crested wheatgrass, and prairie dog colonies. Grasslands were not included in any of the models and had low importance values, although percentage grassland surrounding colonies was high. Management that protects prairie dog colonies bordering cropland and crested wheatgrass should be implemented to maintain nesting habitat of burrowing owls. ?? 2008 Springer Science+Business Media B.V.

  9. Enhanced processing of SPOT multispectral satellite imagery for environmental monitoring and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Clark, B.

    2010-07-01

    The Taita Hills in southeastern Kenya form the northernmost part of Africa's Eastern Arc Mountains, which have been identified by Conservation International as one of the top ten biodiversity hotspots on Earth. As with many areas of the developing world, over recent decades the Taita Hills have experienced significant population growth leading to associated major changes in land use and land cover (LULC), as well as escalating land degradation, particularly soil erosion. Multi-temporal medium resolution multispectral optical satellite data, such as imagery from the SPOT HRV, HRVIR, and HRG sensors, provides a valuable source of information for environmental monitoring and modelling at a landscape level at local and regional scales. However, utilization of multi-temporal SPOT data in quantitative remote sensing studies requires the removal of atmospheric effects and the derivation of surface reflectance factor (rho{sub s}). Furthermore, for areas of rugged terrain, such as the Taita Hills, topographic correction is necessary to derive comparable (rho{sub s}) throughout a SPOT scene. Reliable monitoring of LULC change over time and modelling of land degradation and human population distribution and abundance are of crucial importance to sustainable development, natural resource management, biodiversity conservation, and understanding and mitigating climate change and its impacts. The main purpose of this thesis was to develop and validate enhanced processing of SPOT satellite imagery for use in environmental monitoring and modelling at a landscape level, in regions of the developing world with limited ancillary data availability. The Taita Hills formed the application study site, whilst the Helsinki metropolitan region was used as a control site for validation and assessment of the applied atmospheric correction techniques, where multiangular (rho{sub s}) field measurements were taken and where horizontal visibility meteorological data concurrent with image

  10. A Generalized Schwartz Model for Energy Spot Prices - Estimation using a Particle MCMC Method

    DEFF Research Database (Denmark)

    Lunde, Asger; Brix, Anne Floor; Wei, Wei

    structure. Instead of using various filtering techniques for splitting the two factors, as often found in the literature, we estimate the model in one step using an adaptive MCMC method with a Rao-Blackwellized particle filter. We fit the model to UK natural gas spot prices and investigate the importance......We propose an energy spot price model featuring a two-factor price process and a two-component stochastic volatility process. The first factor in the price process captures the normal variations; the second accounts for spikes. The two-component volatility allows for a flexible autocorrelation...... of spikes and stochastic volatility. We find that the inclusion of stochastic volatility is crucial and that it strongly impacts the jump intensity in the spike process. Furthermore, our estimation method enables us to consider both continuous and purely jump-driven volatility processes, and thereby assess...

  11. Predicting failure response of spot welded joints using recent extensions to the Gurson model

    DEFF Research Database (Denmark)

    Nielsen, Kim Lau

    2010-01-01

    The plug failure modes of resistance spot welded shear-lab and cross-tension test specimens are studied, using recent extensions to the Gurson model. A comparison of the predicted mechanical response is presented when using either: (i) the Gurson-Tvergaard-Needleman model (GTN-model), (ii...... is presented. The models are applied to predict failure of specimens containing a fully intact weld nugget as well as a partly removed weld nugget to address the problems of shrinkage voids or larger weld defects. All analysis are carried out by full 3D finite element modelling....

  12. SPOT Program

    Science.gov (United States)

    Smith, Jason T.; Welsh, Sam J.; Farinetti, Antonio L.; Wegner, Tim; Blakeslee, James; Deboeck, Toni F.; Dyer, Daniel; Corley, Bryan M.; Ollivierre, Jarmaine; Kramer, Leonard; hide

    2010-01-01

    A Spacecraft Position Optimal Tracking (SPOT) program was developed to process Global Positioning System (GPS) data, sent via telemetry from a spacecraft, to generate accurate navigation estimates of the vehicle position and velocity (state vector) using a Kalman filter. This program uses the GPS onboard receiver measurements to sequentially calculate the vehicle state vectors and provide this information to ground flight controllers. It is the first real-time ground-based shuttle navigation application using onboard sensors. The program is compact, portable, self-contained, and can run on a variety of UNIX or Linux computers. The program has a modular objec-toriented design that supports application-specific plugins such as data corruption remediation pre-processing and remote graphics display. The Kalman filter is extensible to additional sensor types or force models. The Kalman filter design is also strong against data dropouts because it uses physical models from state and covariance propagation in the absence of data. The design of this program separates the functionalities of SPOT into six different executable processes. This allows for the individual processes to be connected in an a la carte manner, making the feature set and executable complexity of SPOT adaptable to the needs of the user. Also, these processes need not be executed on the same workstation. This allows for communications between SPOT processes executing on the same Local Area Network (LAN). Thus, SPOT can be executed in a distributed sense with the capability for a team of flight controllers to efficiently share the same trajectory information currently being computed by the program. SPOT is used in the Mission Control Center (MCC) for Space Shuttle Program (SSP) and International Space Station Program (ISSP) operations, and can also be used as a post -flight analysis tool. It is primarily used for situational awareness, and for contingency situations.

  13. Experiences with Aber-OWL, an Ontology Repository with OWL EL Reasoning

    KAUST Repository

    Slater, Luke

    2016-04-19

    Ontologies are widely used in biology and biomedicine for the annotation and integration of data, and hundreds of ontologies have been developed for this purpose. These ontologies also constitute large volumes of formalized domain knowledge, usually expressed in the Web Ontology Language (OWL). Computational access to the knowledge contained within them relies on the use of automated reasoning. We have developed Aber-OWL, an ontology repository that provides OWL EL reasoning to answer queries and verify the consistency of ontologies. Aber-OWL also provides a set of web services which provide ontology-based access to scientific literature in Pubmed and Pubmed Central, SPARQL query expansion to retrieve linked data, and integration with Bio2RDF. Here, we report on our experiences with Aber-OWL and outline a roadmap for future development. Aber-OWL is freely available at http://aber-owl.net.

  14. OWL model of multi-agent Smart-system of distance learning for people with vision disabilities

    Directory of Open Access Journals (Sweden)

    Galina A. Samigulina

    2017-01-01

    Full Text Available The aim of the study is to develop an ontological model of multiagent smart-system of distance learning for visually impaired people based on Java Agent Development Framework for obtaining high-quality engineering education in laboratories of join use on modern equipment.Materials and methods of research. In developing multi-agent smart-system of distance learning, using various agents based on cognitive, ontological, statistical and intellectual methods is important. It is more convenient to implement this task in the form of software using multi-agent approach and Java Agent Development Framework. The main advantages of the platform are stability of operation, clear interface, simplicity of creating agents and extensive user database. In multi-agent systems, the solution is obtained automatically as result of interaction of many independent, purposeful agents. Each agent can perform certain tasks and pursue specified goals. Intellectual multi-agent systems and practical applications in distance learning based on them are considered.Results. The structural diagram of functioning of smart system distance learning for visually impaired people using various agents based on the system approach and the multi-agent platform Java Agent Development Framework is developed. The complex approach of distance learning of visually impaired people for obtaining highquality engineering education in laboratories of joint use on modern equipment is offered.The ontological model of multi-agent smart-system with a detailed description of the functions of following agents is created: personal, manager, ontological, cognitive, statistical, intellectual, shared laboratory agent, health agent, assistant to the agent and state agent. These agents execute their individual functions and provide a quality environment for learning.Conclusion. Thus, the proposed smart-system of distance learning for visually impaired people can significantly improve effectiveness and

  15. Insights from ecological niche modeling on the taxonomic distinction and niche differentiation between the black-spotted and red-spotted tokay geckoes (Gekko gecko)

    OpenAIRE

    Zhang, Yueyun; Chen, Chongtao; Li, Li; Zhao, Chengjian; Chen, Weicai; Huang, Yong

    2014-01-01

    The black-spotted tokay and the red-spotted tokay are morphologically distinct and have largely allopatric distributions. The black-spotted tokay is characterized by a small body size and dark skin with sundry spots, while the red-spotted tokay has a relatively large body size and red spots. Based on morphological, karyotypic, genetic, and distribution differences, recent studies suggested their species status; however, their classifications remain controversial, and additional data such as e...

  16. Chapter 3. Current management situation: Flammulated owls

    Science.gov (United States)

    Jon Verner

    1994-01-01

    The flammulated owl (Otus flammeolus) is a western mountain species associated mainly with ponderosa (Pinus ponderosa) and Jeffrey pine (Pinus jefferyi) forests in the United States and Canada (see Chapter 4). As a neotropical migrant, this small forest owl occurs on national forests in the United States during...

  17. Chapter 8. Current management situation: Boreal owls

    Science.gov (United States)

    Jon Verner

    1994-01-01

    The range of boreal owls (Aegolius funereus) in the United States includes Alaska, the mountains of the western United States, and the northern tier states from the Atlantic to Pacific (see Chapter 9). Based on the species' documented distribution (see National Geographic Society 1987, Hayward et al. 1987, Johnsgard 1988, and others) the owl may...

  18. Viscoelastic Characterization of Long-Eared Owl Flight Feather Shaft and the Damping Ability Analysis

    Directory of Open Access Journals (Sweden)

    Jia-li Gao

    2014-01-01

    Full Text Available Flight feather shaft of long-eared owl is characterized by a three-parameter model for linear viscoelastic solids to reveal its damping ability. Uniaxial tensile tests of the long-eared owl, pigeon, and golden eagle flight feather shaft specimens were carried out based on Instron 3345 single column material testing system, respectively, and viscoelastic response of their stress and strain was described by the standard linear solid model. Parameter fitting result obtained from the tensile tests shows that there is no significant difference in instantaneous elastic modulus for the three birds’ feather shafts, but the owl shaft has the highest viscosity, implying more obvious viscoelastic performance. Dynamic mechanical property was characterized based on the tensile testing results. Loss factor (tanδ of the owl flight feather shaft was calculated to be 1.609 ± 0.238, far greater than those of the pigeon (0.896 ± 0.082 and golden eagle (1.087 ± 0.074. It is concluded that the long-eared owl flight feather has more outstanding damping ability compared to the pigeon and golden eagle flight feather shaft. Consequently, the long-eared owl flight feathers can dissipate the vibration energy more effectively during the flying process based on the principle of damping mechanism, for the purpose of vibration attenuation and structure radiated noise reduction.

  19. An empirical comparison of alternate regime-switching models for electricity spot prices

    Energy Technology Data Exchange (ETDEWEB)

    Janczura, Joanna [Hugo Steinhaus Center, Institute of Mathematics and Computer Science, Wroclaw University of Technology, 50-370 Wroclaw (Poland); Weron, Rafal [Institute of Organization and Management, Wroclaw University of Technology, 50-370 Wroclaw (Poland)

    2010-09-15

    One of the most profound features of electricity spot prices are the price spikes. Markov regime-switching (MRS) models seem to be a natural candidate for modeling this spiky behavior. However, in the studies published so far, the goodness-of-fit of the proposed models has not been a major focus. While most of the models were elegant, their fit to empirical data has either been not examined thoroughly or the signs of a bad fit ignored. With this paper we want to fill the gap. We calibrate and test a range of MRS models in an attempt to find parsimonious specifications that not only address the main characteristics of electricity prices but are statistically sound as well. We find that the best structure is that of an independent spike 3-regime model with time-varying transition probabilities, heteroscedastic diffusion-type base regime dynamics and shifted spike regime distributions. Not only does it allow for a seasonal spike intensity throughout the year and consecutive spikes or price drops, which is consistent with market observations, but also exhibits the 'inverse leverage effect' reported in the literature for spot electricity prices. (author)

  20. The Red Queen model of recombination hot-spot evolution: a theoretical investigation.

    Science.gov (United States)

    Latrille, Thibault; Duret, Laurent; Lartillot, Nicolas

    2017-12-19

    In humans and many other species, recombination events cluster in narrow and short-lived hot spots distributed across the genome, whose location is determined by the Zn-finger protein PRDM9. To explain these fast evolutionary dynamics, an intra-genomic Red Queen model has been proposed, based on the interplay between two antagonistic forces: biased gene conversion, mediated by double-strand breaks, resulting in hot-spot extinction, followed by positive selection favouring new PRDM9 alleles recognizing new sequence motifs. Thus far, however, this Red Queen model has not been formalized as a quantitative population-genetic model, fully accounting for the intricate interplay between biased gene conversion, mutation, selection, demography and genetic diversity at the PRDM9 locus. Here, we explore the population genetics of the Red Queen model of recombination. A Wright-Fisher simulator was implemented, allowing exploration of the behaviour of the model (mean equilibrium recombination rate, diversity at the PRDM9 locus or turnover rate) as a function of the parameters (effective population size, mutation and erosion rates). In a second step, analytical results based on self-consistent mean-field approximations were derived, reproducing the scaling relations observed in the simulations. Empirical fit of the model to current data from the mouse suggests both a high mutation rate at PRDM9 and strong biased gene conversion on its targets.This article is part of the themed issue 'Evolutionary causes and consequences of recombination rate variation in sexual organisms'. © 2017 The Authors.

  1. An empirical comparison of alternate regime-switching models for electricity spot prices

    International Nuclear Information System (INIS)

    Janczura, Joanna; Weron, Rafal

    2010-01-01

    One of the most profound features of electricity spot prices are the price spikes. Markov regime-switching (MRS) models seem to be a natural candidate for modeling this spiky behavior. However, in the studies published so far, the goodness-of-fit of the proposed models has not been a major focus. While most of the models were elegant, their fit to empirical data has either been not examined thoroughly or the signs of a bad fit ignored. With this paper we want to fill the gap. We calibrate and test a range of MRS models in an attempt to find parsimonious specifications that not only address the main characteristics of electricity prices but are statistically sound as well. We find that the best structure is that of an independent spike 3-regime model with time-varying transition probabilities, heteroscedastic diffusion-type base regime dynamics and shifted spike regime distributions. Not only does it allow for a seasonal spike intensity throughout the year and consecutive spikes or price drops, which is consistent with market observations, but also exhibits the 'inverse leverage effect' reported in the literature for spot electricity prices. (author)

  2. Technical Note: Using experimentally determined proton spot scanning timing parameters to accurately model beam delivery time.

    Science.gov (United States)

    Shen, Jiajian; Tryggestad, Erik; Younkin, James E; Keole, Sameer R; Furutani, Keith M; Kang, Yixiu; Herman, Michael G; Bues, Martin

    2017-10-01

    To accurately model the beam delivery time (BDT) for a synchrotron-based proton spot scanning system using experimentally determined beam parameters. A model to simulate the proton spot delivery sequences was constructed, and BDT was calculated by summing times for layer switch, spot switch, and spot delivery. Test plans were designed to isolate and quantify the relevant beam parameters in the operation cycle of the proton beam therapy delivery system. These parameters included the layer switch time, magnet preparation and verification time, average beam scanning speeds in x- and y-directions, proton spill rate, and maximum charge and maximum extraction time for each spill. The experimentally determined parameters, as well as the nominal values initially provided by the vendor, served as inputs to the model to predict BDTs for 602 clinical proton beam deliveries. The calculated BDTs (T BDT ) were compared with the BDTs recorded in the treatment delivery log files (T Log ): ∆t = T Log -T BDT . The experimentally determined average layer switch time for all 97 energies was 1.91 s (ranging from 1.9 to 2.0 s for beam energies from 71.3 to 228.8 MeV), average magnet preparation and verification time was 1.93 ms, the average scanning speeds were 5.9 m/s in x-direction and 19.3 m/s in y-direction, the proton spill rate was 8.7 MU/s, and the maximum proton charge available for one acceleration is 2.0 ± 0.4 nC. Some of the measured parameters differed from the nominal values provided by the vendor. The calculated BDTs using experimentally determined parameters matched the recorded BDTs of 602 beam deliveries (∆t = -0.49 ± 1.44 s), which were significantly more accurate than BDTs calculated using nominal timing parameters (∆t = -7.48 ± 6.97 s). An accurate model for BDT prediction was achieved by using the experimentally determined proton beam therapy delivery parameters, which may be useful in modeling the interplay effect and patient throughput. The model may

  3. Identifying spikes and seasonal components in electricity spot price data: A guide to robust modeling

    International Nuclear Information System (INIS)

    Janczura, Joanna; Trück, Stefan; Weron, Rafał; Wolff, Rodney C.

    2013-01-01

    An important issue in fitting stochastic models to electricity spot prices is the estimation of a component to deal with trends and seasonality in the data. Unfortunately, estimation routines for the long-term and short-term seasonal pattern are usually quite sensitive to extreme observations, known as electricity price spikes. Improved robustness of the model can be achieved by (a) filtering the data with some reasonable procedure for outlier detection, and then (b) using estimation and testing procedures on the filtered data. In this paper we examine the effects of different treatments of extreme observations on model estimation and on determining the number of spikes (outliers). In particular we compare results for the estimation of the seasonal and stochastic components of electricity spot prices using either the original or filtered data. We find significant evidence for a superior estimation of both the seasonal short-term and long-term components when the data have been treated carefully for outliers. Overall, our findings point out the substantial impact the treatment of extreme observations may have on these issues and, therefore, also on the pricing of electricity derivatives like futures and option contracts. An added value of our study is the ranking of different filtering techniques used in the energy economics literature, suggesting which methods could be and which should not be used for spike identification. - Highlights: • First comprehensive study on the impact of spikes on seasonal pattern estimation • The effects of different treatments of spikes on model estimation are examined. • Cleaning spot prices for outliers yields superior estimates of the seasonal pattern. • Removing outliers provides better parameter estimates for the stochastic process. • Rankings of filtering techniques suggested in the literature are provided

  4. Improving Stiffness-to-weight Ratio of Spot-welded Structures based upon Nonlinear Finite Element Modelling

    Science.gov (United States)

    Zhang, Shengyong

    2017-07-01

    Spot welding has been widely used for vehicle body construction due to its advantages of high speed and adaptability for automation. An effort to increase the stiffness-to-weight ratio of spot-welded structures is investigated based upon nonlinear finite element analysis. Topology optimization is conducted for reducing weight in the overlapping regions by choosing an appropriate topology. Three spot-welded models (lap, doubt-hat and T-shape) that approximate “typical” vehicle body components are studied for validating and illustrating the proposed method. It is concluded that removing underutilized material from overlapping regions can result in a significant increase in structural stiffness-to-weight ratio.

  5. Coherent and incoherent J /ψ photonuclear production in an energy-dependent hot-spot model

    Science.gov (United States)

    Cepila, J.; Contreras, J. G.; Krelina, M.

    2018-02-01

    In a previous publication, we have presented a model for the photoproduction of J /ψ vector mesons off protons, where the proton structure in the impact-parameter plane is described by an energy-dependent hot-spot profile. Here we extend this model to study the photonuclear production of J /ψ vector mesons in coherent and incoherent interactions of heavy nuclei. We study two methods to extend the model to the nuclear case: using the standard Glauber-Gribov formalism and using geometric scaling to obtain the nuclear saturation scale. We find that the incoherent cross section changes sizably with the inclusion of subnucleonic hot spots and that this change is energy dependent. We propose to search for this behavior by measuring the ratio of the incoherent to coherent cross sections at different energies. We compare the results of our model to results from the Relativistic Heavy-Ion Collider (RHIC) and from run 1 at the Large Hadron Collider (LHC), finding satisfactory agreement. We also present predictions for the LHC at the new energies reached in run 2. The predictions include J /ψ production in ultraperipheral collisions, as well as the recently observed photonuclear production in peripheral collisions.

  6. Rough electricity: a new fractal multi-factor model of electricity spot prices

    DEFF Research Database (Denmark)

    Bennedsen, Mikkel

    We introduce a new mathematical model of electricity spot prices which accounts for the most important stylized facts of these time series: seasonality, spikes, stochastic volatility and mean reversion. Empirical studies have found a possible fifth stylized fact, fractality, and our approach...... explicitly incorporates this into the model of the prices. Our setup generalizes the popular Ornstein Uhlenbeck-based multi-factor framework of Benth et al. (2007) and allows us to perform statistical tests to distinguish between an Ornstein Uhlenbeck-based model and a fractal model. Further, through...... the multi-factor approach we account for seasonality and spikes before estimating - and making inference on - the degree of fractality. This is novel in the literature and we present simulation evidence showing that these precautions are crucial to accurate estimation. Lastly, we estimate our model...

  7. Dose-response model of Rocky Mountain spotted fever (RMSF) for human.

    Science.gov (United States)

    Tamrakar, Sushil B; Haas, Charles N

    2011-10-01

    Rickettsia rickettsii is the causative agent of Rocky Mountain spotted fever (RMSF) and is the prototype bacterium in the spotted fever group of rickettsiae, which is found in North, Central, and South America. The bacterium is gram negative and an obligate intracellular pathogen. The disease is transmitted to humans and vertebrate host through tick bites; however, some cases of aerosol transmission also have been reported. The disease can be difficult to diagnose in the early stages, and without prompt and appropriate treatment, it can be fatal. This article develops dose-response models of different routes of exposure for RMSF in primates and humans. The beta-Poisson model provided the best fit to the dose-response data of aerosol-exposed rhesus monkeys, and intradermally inoculated humans (morbidity as end point of response). The average 50% infectious dose among (ID₅₀) exposed human population, N₅₀, is 23 organisms with 95% confidence limits of 1 to 89 organisms. Similarly, ID₁₀ and ID₂₀ are 2.2 and 5.0, respectively. Moreover, the data of aerosol-exposed rhesus monkeys and intradermally inoculated humans could be pooled. This indicates that the dose-response models fitted to different data sets are not significantly different and can be described by the same relationship. © 2011 Society for Risk Analysis.

  8. Map-Based Repowering and Reorganization of a Wind Resource Area to Minimize Burrowing Owl and Other Bird Fatalities

    Directory of Open Access Journals (Sweden)

    Lee Neher

    2009-10-01

    Full Text Available Wind turbines in the Altamont Pass Wind Resource Area (Alameda/Contra Costa Counties, California, USA generate about 730 GWh of electricity annually, but have been killing thousands of birds each year, including >2,000 raptors and hundreds of burrowing owls. We have developed collision hazard maps and hazard ratings of wind turbines to guide relocation of existing wind turbines and careful repowering to modern turbines to reduce burrowing owl fatalities principally, and other birds secondarily. Burrowing owls selected burrow sites lower on slopes and on smaller, shallower slopes than represented by the average 10 × 10 m2 grid cell among 187,908 grid cells sampled from 2,281,169 grid cells comprising a digital elevation model (DEM of the study area. Fuzzy logic and discriminant function analysis produced likelihood surfaces encompassing most burrowing owl burrows within a fraction of the study area, and the former corresponded with burrowing owl fatalities and the latter with other raptor fatalities. Our ratings of wind turbine hazard were more predictive of burrowing owl fatalities, but would be more difficult to implement. Careful repowering to modern wind turbines would most reduce fatalities of burrowing owls and other birds while adding about 1,000 GWh annually toward California’s 33% Renewable Portfolio Standard.

  9. Map-based repowering and reorganization of a wind resource area to minimize burrowing owl and other bird fatalities

    Energy Technology Data Exchange (ETDEWEB)

    Smallwood, K. S. [Research Ecologist, 3108 Finch Street, Davis, CA 95616 (United States); Neher, L. [Gis Specialist, Neher Consulting, 7241 34th Street, North Highlands, CA 95660 (United States); Bell, D. A. [East Bay Regional Park District, 2950 Peralta Oaks Court, Oakland, CA 94605-0381 (United States)

    2009-07-01

    Wind turbines in the Altamont Pass Wind Resource Area (Alameda/Contra Costa Counties, California, USA) generate about 730 GWh of electricity annually, but have been killing thousands of birds each year, including >2,000 raptors and hundreds of burrowing owls. We have developed collision hazard maps and hazard ratings of wind turbines to guide relocation of existing wind turbines and careful repowering to modern turbines to reduce burrowing owl fatalities principally, and other birds secondarily. Burrowing owls selected burrow sites lower on slopes and on smaller, shallower slopes than represented by the average 10 x 10 m{sup 2} grid cell among 187,908 grid cells sampled from 2,281,169 grid cells comprising a digital elevation model (DEM) of the study area. Fuzzy logic and discriminant function analysis produced likelihood surfaces encompassing most burrowing owl burrows within a fraction of the study area, and the former corresponded with burrowing owl fatalities and the latter with other raptor fatalities. Our ratings of wind turbine hazard were more predictive of burrowing owl fatalities, but would be more difficult to implement. Careful repowering to modern wind turbines would most reduce fatalities of burrowing owls and other birds while adding about 1,000 GWh annually toward California's 33% Renewable Portfolio Standard. (author)

  10. Visual-auditory integration for visual search: a behavioral study in barn owls

    Directory of Open Access Journals (Sweden)

    Yael eHazan

    2015-02-01

    Full Text Available Barn owls are nocturnal predators that rely on both vision and hearing for survival. The optic tectum of barn owls, a midbrain structure involved in selective attention, has been used as a model for studying visual- auditory integration at the neuronal level. However, behavioral data on visual- auditory integration in barn owls are lacking. The goal of this study was to examine if the integration of visual and auditory signals contributes to the process of guiding attention towards salient stimuli. We attached miniature wireless video cameras on barn owls' heads (OwlCam to track their target of gaze. We first provide evidence that the area centralis (a retinal area with a maximal density of photoreceptors is used as a functional fovea in barn owls. Thus, by mapping the projection of the area centralis on the OwlCam's video frame, it is possible to extract the target of gaze. For the experiment, owls were positioned on a high perch and four food items were scattered in a large arena on the floor. In addition, a hidden loudspeaker was positioned in the arena. The positions of the food items and speaker were changed every session. Video sequences from the OwlCam were saved for offline analysis while the owls spontaneously scanned the room and the food items with abrupt gaze shifts (head saccades. From time to time during the experiment, a brief sound was emitted from the speaker. The fixation points immediately following the sounds were extracted and the distances between the gaze position and the nearest items and loudspeaker were measured. The head saccades were rarely towards the location of the sound source but to salient visual features in the room, such as the door knob or the food items. However, among the food items, the one closest to the loudspeaker had the highest probability of attracting a gaze shift. This result supports the notion that auditory signals are integrated with visual information for the selection of the next visual search

  11. Burrowing Owl - Palo Verde Valley [ds197

    Data.gov (United States)

    California Natural Resource Agency — These burrowing owl observations were collected during the spring and early summer of 1976 in the Palo Verde Valley, eastern Riverside County, California. This is an...

  12. Regression and artificial neural network modeling for the prediction of gray leaf spot of maize.

    Science.gov (United States)

    Paul, P A; Munkvold, G P

    2005-04-01

    ABSTRACT Regression and artificial neural network (ANN) modeling approaches were combined to develop models to predict the severity of gray leaf spot of maize, caused by Cercospora zeae-maydis. In all, 329 cases consisting of environmental, cultural, and location-specific variables were collected for field plots in Iowa between 1998 and 2002. Disease severity on the ear leaf at the dough to dent plant growth stage was used as the response variable. Correlation and regression analyses were performed to select potentially useful predictor variables. Predictors from the best 9 of 80 regression models were used to develop ANN models. A random sample of 60% of the cases was used to train the networks, and 20% each for testing and validation. Model performance was evaluated based on coefficient of determination (R(2)) and mean square error (MSE) for the validation data set. The best models had R(2) ranging from 0.70 to 0.75 and MSE ranging from 174.7 to 202.8. The most useful predictor variables were hours of daily temperatures between 22 and 30 degrees C (85.50 to 230.50 h) and hours of nightly relative humidity >/=90% (122 to 330 h) for the period between growth stages V4 and V12, mean nightly temperature (65.26 to 76.56 degrees C) for the period between growth stages V12 and R2, longitude (90.08 to 95.14 degrees W), maize residue on the soil surface (0 to 100%), planting date (in day of the year; 112 to 182), and gray leaf spot resistance rating (2 to 7; based on a 1-to-9 scale, where 1 = most susceptible to 9 = most resistant).

  13. The effects of forest structure on occurrence and abundance of three owl species (Aves: Strigidae in the Central Amazon forest

    Directory of Open Access Journals (Sweden)

    Obed G. Barros

    2009-03-01

    Full Text Available We investigated how forest structure affects the occurrence and abundance of three owl species: the crested owl Lophostrix cristata Daudin, 1800, the Amazon pygmy owl Glaucidium hardyi Vielliard, 1990, and the tawny-bellied screech owl Megascops watsonii Cassin, 1849. We surveyed the owls mostly between 07:00 and 11:00 pm from July 2001 to April 2002, in eighteen 8 km transects along trails at the Ducke Reserve, Manaus, Central Amazon, Brazil. We staked out 50 x 50 m plots where the presence and absence of the owls were recorded. We compared some components of the forest structure between plots where owls were present and plots where they were absent. The spatial variation in these components were related to the occurrence and abundance of the owls using models of multiple logistic and multiple linear regressions analysis, respectively. Lophostrix cristata is rare in many other areas of the Amazon forest, but it was the most abundant in our study area. Lophostrix cristata and G. hardyi were more concentrated along the uplands (central plateau, which divide the reserve into two drainage water-basins. Megascops watsonii was distributed mainly in the southeastern part of the reserve. Glaucidium hardyi was more often found in areas with larger canopy openness. In areas with higher abundance of snags, there was significantly higher occurrence of L. cristata and M. watsonii. Megascops watsonii was also more abundant in areas with higher abundance of forest trees and in areas bearing shallower leaf litter on the forest floor. This study is the first to analyze at large spatial scale the effects of forest structure on neotropical forest top predator nocturnal birds. The results indicate that forest structure can affect the occurrence and abundance of owls in the Amazon forest.

  14. Paraconsistent Reasoning for OWL 2

    Science.gov (United States)

    Ma, Yue; Hitzler, Pascal

    A four-valued description logic has been proposed to reason with description logic based inconsistent knowledge bases. This approach has a distinct advantage that it can be implemented by invoking classical reasoners to keep the same complexity as under the classical semantics. However, this approach has so far only been studied for the basic description logic mathcal{ALC}. In this paper, we further study how to extend the four-valued semantics to the more expressive description logic mathcal{SROIQ} which underlies the forthcoming revision of the Web Ontology Language, OWL 2, and also investigate how it fares when adapted to tractable description logics including mathcal{EL++}, DL-Lite, and Horn-DLs. We define the four-valued semantics along the same lines as for mathcal{ALC} and show that we can retain most of the desired properties.

  15. Predicting favorable conditions for early leaf spot of peanut using output from the Weather Research and Forecasting (WRF) model

    Science.gov (United States)

    Olatinwo, Rabiu O.; Prabha, Thara V.; Paz, Joel O.; Hoogenboom, Gerrit

    2012-03-01

    Early leaf spot of peanut ( Arachis hypogaea L.), a disease caused by Cercospora arachidicola S. Hori, is responsible for an annual crop loss of several million dollars in the southeastern United States alone. The development of early leaf spot on peanut and subsequent spread of the spores of C. arachidicola relies on favorable weather conditions. Accurate spatio-temporal weather information is crucial for monitoring the progression of favorable conditions and determining the potential threat of the disease. Therefore, the development of a prediction model for mitigating the risk of early leaf spot in peanut production is important. The specific objective of this study was to demonstrate the application of the high-resolution Weather Research and Forecasting (WRF) model for management of early leaf spot in peanut. We coupled high-resolution weather output of the WRF, i.e. relative humidity and temperature, with the Oklahoma peanut leaf spot advisory model in predicting favorable conditions for early leaf spot infection over Georgia in 2007. Results showed a more favorable infection condition in the southeastern coastline of Georgia where the infection threshold were met sooner compared to the southwestern and central part of Georgia where the disease risk was lower. A newly introduced infection threat index indicates that the leaf spot threat threshold was met sooner at Alma, GA, compared to Tifton and Cordele, GA. The short-term prediction of weather parameters and their use in the management of peanut diseases is a viable and promising technique, which could help growers make accurate management decisions, and lower disease impact through optimum timing of fungicide applications.

  16. Determining Time-Varying Drivers of Spot Oil Price in a Dynamic Model Averaging Framework

    Directory of Open Access Journals (Sweden)

    Krzysztof Drachal

    2018-05-01

    Full Text Available This article presents results from modelling spot oil prices by Dynamic Model Averaging (DMA. First, based on a literature review and availability of data, the following oil price drivers have been selected: stock prices indices, stock prices volatility index, exchange rates, global economic activity, interest rates, supply and demand indicators and inventories level. Next, they have been included as explanatory variables in various DMA models with different initial parameters. Monthly data between January 1986 and December 2015 has been analyzed. Several variations of DMA models have been constructed, because DMA requires the initial setting of certain parameters. Interestingly, DMA has occurred to be robust to setting different values to these parameters. It has also occurred that the quality of prediction is the highest for the model with the drivers solely connected with the stock markets behavior. Drivers connected with macroeconomic fundamental indicators have not been found so important. This observation can serve as an argument favoring the hypothesis of the increasing financialization of the oil market, at least in the short-term period. The predictions from other, slightly different modelling variations based on DMA methodology, have happened to be consistent with each other in general. Many constructed models have outperformed alternative forecasting methods. It has also been found that normalization of the initial data, although not necessary for DMA from the theoretical point of view, significantly improves the quality of prediction.

  17. "Rickettsia amblyommii" induces cross protection against lethal Rocky Mountain spotted fever in a guinea pig model.

    Science.gov (United States)

    Blanton, Lucas S; Mendell, Nicole L; Walker, David H; Bouyer, Donald H

    2014-08-01

    Rocky Mountain spotted fever (RMSF) is a severe illness caused by Rickettsia rickettsii for which there is no available vaccine. We hypothesize that exposure to the highly prevalent, relatively nonpathogenic "Rickettsia amblyommii" protects against R. rickettsii challenge. To test this hypothesis, guinea pigs were inoculated with "R. amblyommii." After inoculation, the animals showed no signs of illness. When later challenged with lethal doses of R. rickettsii, those previously exposed to "R. amblyommii" remained well, whereas unimmunized controls developed severe illness and died. We conclude that "R. amblyommii" induces an immune response that protects from illness and death in the guinea pig model of RMSF. These results provide a basis for exploring the use of low-virulence rickettsiae as a platform to develop live attenuated vaccine candidates to prevent severe rickettsioses.

  18. Comparative food niche analysis of Strix Owls in Belarus

    Science.gov (United States)

    Alexey K. Tishechkin

    1997-01-01

    Three Strix species breed sympatrically in Belarus. The Tawny Owl (Strix aluco) is one of two commonest owl species in the country, and is distributed throughout the whole territory. Its' range overlaps widely with two other species, the Ural Owl (S. uralensis) which is common in the forests of the northern part and the Great...

  19. Ignition conditions relaxation for central hot-spot ignition with an ion-electron non-equilibrium model

    Science.gov (United States)

    Fan, Zhengfeng; Liu, Jie

    2016-10-01

    We present an ion-electron non-equilibrium model, in which the hot-spot ion temperature is higher than its electron temperature so that the hot-spot nuclear reactions are enhanced while energy leaks are considerably reduced. Theoretical analysis shows that the ignition region would be significantly enlarged in the hot-spot rhoR-T space as compared with the commonly used equilibrium model. Simulations show that shocks could be utilized to create and maintain non-equilibrium conditions within the hot spot, and the hot-spot rhoR requirement is remarkably reduced for achieving self-heating. In NIF high-foot implosions, it is observed that the x-ray enhancement factors are less than unity, which is not self-consistent and is caused by assuming Te =Ti. And from this non-consistency, we could infer that ion-electron non-equilibrium exists in the high-foot implosions and the ion temperature could be 9% larger than the equilibrium temperature.

  20. Modelling price and volatility inter-relationships in the Australian wholesale spot electricity markets

    International Nuclear Information System (INIS)

    Higgs, Helen

    2009-01-01

    This paper examines the inter-relationships of wholesale spot electricity prices among the four regional electricity markets in the Australian National Electricity Market (NEM): namely, New South Wales, Queensland, South Australia and Victoria using the constant conditional correlation and Tse and Tsui's (Tse, Y.K., Tsui, A.K.C., 2002. A multivariate generalised autoregressive conditional heteroscedasticity model with time-varying correlations. Journal of Business and Economic Statistics 20 (3), 351-362.) and Engle's (Engle, R., 2002. Dynamic conditional correlation: a sample class of multivariate generalized autoregressive conditional heteroskedasticity models. Journal of Business and Economic Statistics 20 (3), 339-350.) dynamic conditional correlation multivariate GARCH models. Tse and Tsui's (Tse, Y.K., Tsui, A.K.C., 2002. A multivariate generalised autoregressive conditional heteroscedasticity model with time-varying correlations. Journal of Business and Economic Statistics 20 (3), 351-362.) dynamic conditional correlation multivariate GARCH model which takes account of the Student t specification produces the best results. At the univariate GARCH(1,1) level, the mean equations indicate the presence of positive own mean spillovers in all four markets and little evidence of mean spillovers from the other lagged markets. In the dynamic conditional correlation equation, the highest conditional correlations are evident between the well-connected markets indicating the presence of strong interdependence between these markets with weaker interdependence between the not so well-interconnected markets. (author)

  1. Particle-in-cell studies of laser-driven hot spots and a statistical model for mesoscopic properties of Raman backscatter

    International Nuclear Information System (INIS)

    Albright, B.J.; Yin, L.; Bowers, K.J.; Kline, J.L.; Montgomery, D.S.; Fernandez, J.C.; Daughton, W.

    2006-01-01

    The authors use explicit particle-in-cell simulations to model stimulated scattering processes in media with both solitary and multiple laser hot spots. These simulations indicate coupling among hot spots, whereby scattered light, plasma waves, and hot electrons generated in one laser hot spot may propagate to neighboring hot spots, which can be destabilized to enhanced backscatter. A nonlinear statistical model of a stochastic beam exhibiting this coupled behavior is described here. Calibration of the model using particle-in-cell simulations is performed, and a threshold is derived for 'detonation' of the beam to high reflectivity. (authors)

  2. THE PERIOD VARIATION OF AND A SPOT MODEL FOR THE ECLIPSING BINARY AR BOOTIS

    International Nuclear Information System (INIS)

    Lee, Jae Woo; Youn, Jae-Hyuck; Lee, Chung-Uk; Kim, Seung-Lee; Koch, Robert H.

    2009-01-01

    New CCD photometric observations of the eclipsing system AR Boo were obtained from 2006 February to 2008 April. The star's photometric properties are derived from detailed studies of the period variability and of all available light curves. We find that over about 56 yr the orbital period of the system has varied due to a combination of an upward parabola and a sinusoid rather than in a monotonic fashion. Mass transfer from the less massive primary to the more massive secondary component is likely responsible for at least a significant part of the secular period change. The cyclical variation with a period of 7.57 yr and a semi-amplitude of 0.0015 d can be produced either by a light-travel-time effect due to an unseen companion with a scaled mass of M 3 sin i 3 = 0.081 M sun or by a magnetic period modulation in the secondary star. Historical light curves of AR Boo, as well as our own, display season-to-season light variability, which are best modeled by including both a cool spot and a hot one on the secondary star. We think that the spots express magnetic dynamo-related activity and offer limited support for preferring the magnetic interpretation of the 7.57 yr cycle over the third-body interpretation. Our solutions confirm that AR Boo belongs to the W-subtype contact binary class, consisting of a hotter, less massive primary star with a spectral type of G9 and a companion of spectral type K1.

  3. A No-Arbitrage Fractional Cointegration Model for Futures and Spot Daily Ranges

    DEFF Research Database (Denmark)

    Rossi, Eduardo; Santucci de Magistris, Paolo

    2013-01-01

    The no-arbitrage relation between futures and spot prices implies an analogous relation between futures and spot daily ranges. The long-memory features of the range-based volatility estimators are analyzed, and fractional cointegration is tested in a semi-parametric framework. In particular, the no...

  4. WEIBULL MULTIPLICATIVE MODEL AND MACHINE LEARNING MODELS FOR FULL-AUTOMATIC DARK-SPOT DETECTION FROM SAR IMAGES

    Directory of Open Access Journals (Sweden)

    A. Taravat

    2013-09-01

    Full Text Available As a major aspect of marine pollution, oil release into the sea has serious biological and environmental impacts. Among remote sensing systems (which is a tool that offers a non-destructive investigation method, synthetic aperture radar (SAR can provide valuable synoptic information about the position and size of the oil spill due to its wide area coverage and day/night, and all-weather capabilities. In this paper we present a new automated method for oil-spill monitoring. A new approach is based on the combination of Weibull Multiplicative Model and machine learning techniques to differentiate between dark spots and the background. First, the filter created based on Weibull Multiplicative Model is applied to each sub-image. Second, the sub-image is segmented by two different neural networks techniques (Pulsed Coupled Neural Networks and Multilayer Perceptron Neural Networks. As the last step, a very simple filtering process is used to eliminate the false targets. The proposed approaches were tested on 20 ENVISAT and ERS2 images which contained dark spots. The same parameters were used in all tests. For the overall dataset, the average accuracies of 94.05 % and 95.20 % were obtained for PCNN and MLP methods, respectively. The average computational time for dark-spot detection with a 256 × 256 image in about 4 s for PCNN segmentation using IDL software which is the fastest one in this field at present. Our experimental results demonstrate that the proposed approach is very fast, robust and effective. The proposed approach can be applied to the future spaceborne SAR images.

  5. Weibull Multiplicative Model and Machine Learning Models for Full-Automatic Dark-Spot Detection from SAR Images

    Science.gov (United States)

    Taravat, A.; Del Frate, F.

    2013-09-01

    As a major aspect of marine pollution, oil release into the sea has serious biological and environmental impacts. Among remote sensing systems (which is a tool that offers a non-destructive investigation method), synthetic aperture radar (SAR) can provide valuable synoptic information about the position and size of the oil spill due to its wide area coverage and day/night, and all-weather capabilities. In this paper we present a new automated method for oil-spill monitoring. A new approach is based on the combination of Weibull Multiplicative Model and machine learning techniques to differentiate between dark spots and the background. First, the filter created based on Weibull Multiplicative Model is applied to each sub-image. Second, the sub-image is segmented by two different neural networks techniques (Pulsed Coupled Neural Networks and Multilayer Perceptron Neural Networks). As the last step, a very simple filtering process is used to eliminate the false targets. The proposed approaches were tested on 20 ENVISAT and ERS2 images which contained dark spots. The same parameters were used in all tests. For the overall dataset, the average accuracies of 94.05 % and 95.20 % were obtained for PCNN and MLP methods, respectively. The average computational time for dark-spot detection with a 256 × 256 image in about 4 s for PCNN segmentation using IDL software which is the fastest one in this field at present. Our experimental results demonstrate that the proposed approach is very fast, robust and effective. The proposed approach can be applied to the future spaceborne SAR images.

  6. Moonlight Makes Owls More Chatty

    Science.gov (United States)

    Penteriani, Vincenzo; Delgado, María del Mar; Campioni, Letizia; Lourenço, Rui

    2010-01-01

    Background Lunar cycles seem to affect many of the rhythms, temporal patterns and behaviors of living things on Earth. Ambient light is known to affect visual communication in animals, with the conspicuousness of visual signals being largely determined by the light available for reflection by the sender. Although most previous studies in this context have focused on diurnal light, moonlight should not be neglected from the perspective of visual communication among nocturnal species. We recently discovered that eagle owls Bubo bubo communicate with conspecifics using a patch of white throat plumage that is repeatedly exposed during each call and is only visible during vocal displays. Methodology/Principal Findings Here we provide evidence that this species uses moonlight to increase the conspicuousness of this visual signal during call displays. We found that call displays are directly influenced by the amount of moonlight, with silent nights being more frequent during periods with no-moonlight than moonlight. Furthermore, high numbers of calling bouts were more frequent at moonlight. Finally, call posts were located on higher positions on moonlit nights. Conclusions/Significance Our results support the idea that moon phase affects the visual signaling behavior of this species, and provide a starting point for examination of this method of communication by nocturnal species. PMID:20098700

  7. Moonlight makes owls more chatty.

    Directory of Open Access Journals (Sweden)

    Vincenzo Penteriani

    2010-01-01

    Full Text Available Lunar cycles seem to affect many of the rhythms, temporal patterns and behaviors of living things on Earth. Ambient light is known to affect visual communication in animals, with the conspicuousness of visual signals being largely determined by the light available for reflection by the sender. Although most previous studies in this context have focused on diurnal light, moonlight should not be neglected from the perspective of visual communication among nocturnal species. We recently discovered that eagle owls Bubo bubo communicate with conspecifics using a patch of white throat plumage that is repeatedly exposed during each call and is only visible during vocal displays.Here we provide evidence that this species uses moonlight to increase the conspicuousness of this visual signal during call displays. We found that call displays are directly influenced by the amount of moonlight, with silent nights being more frequent during periods with no-moonlight than moonlight. Furthermore, high numbers of calling bouts were more frequent at moonlight. Finally, call posts were located on higher positions on moonlit nights.Our results support the idea that moon phase affects the visual signaling behavior of this species, and provide a starting point for examination of this method of communication by nocturnal species.

  8. Analysis of M-stationary points to an EPEC modeling oligopolistic competition in an electricity spot market

    Czech Academy of Sciences Publication Activity Database

    Henrion, R.; Outrata, Jiří; Surowiec, T.

    2012-01-01

    Roč. 18, č. 2 (2012), s. 295-317 ISSN 1292-8119 R&D Projects: GA ČR GA201/09/1957 Institutional support: RVO:67985556 Keywords : Equilibrium problems with equilibrium constraints * EPEC * M-stationary solutions * electricity spot market * calmness Subject RIV: BA - General Mathematics Impact factor: 1.282, year: 2012 http://library.utia.cas.cz/separaty/2012/MTR/outrata-analysis of m-stationary points to an epec modeling oligopolistic competition in an electricity spot market.pdf

  9. F-OWL: An Inference Engine for Semantic Web

    Science.gov (United States)

    Zou, Youyong; Finin, Tim; Chen, Harry

    2004-01-01

    Understanding and using the data and knowledge encoded in semantic web documents requires an inference engine. F-OWL is an inference engine for the semantic web language OWL language based on F-logic, an approach to defining frame-based systems in logic. F-OWL is implemented using XSB and Flora-2 and takes full advantage of their features. We describe how F-OWL computes ontology entailment and compare it with other description logic based approaches. We also describe TAGA, a trading agent environment that we have used as a test bed for F-OWL and to explore how multiagent systems can use semantic web concepts and technology.

  10. Towards Self-managed Pervasive Middleware using OWL/SWRL ontologies

    DEFF Research Database (Denmark)

    Zhang, Weishan; Hansen, Klaus Marius

    2008-01-01

    Self-management for pervasive middleware is important to realize the Ambient Intelligence vision. In this paper, we present an OWL/SWRL context ontologies based self-management approach for pervasive middleware where OWL ontology is used as means for context modeling. The context ontologies....../SWRL context ontologies based self-management approach with the self-diagnosis in Hydra middleware, using device state machine and other dynamic context information, for example web service calls. The evaluations in terms of extensibility, performance and scalability show that this approach is effective...

  11. Modeling of electric and heat processes in spot resistance welding of cross-wire steel bars

    Science.gov (United States)

    Iatcheva, Ilona; Darzhanova, Denitsa; Manilova, Marina

    2018-03-01

    The aim of this work is the modeling of coupled electric and heat processes in a system for spot resistance welding of cross-wire reinforced steel bars. The real system geometry, dependences of material properties on the temperature, and changes of contact resistance and released power during the welding process have been taken into account in the study. The 3D analysis of the coupled AC electric and transient thermal field distributions is carried out using the finite element method. The novel feature is that the processes are modeled for several successive time stages, corresponding to the change of contact area, related contact resistance, and reduction of the released power, occurring simultaneously with the creation of contact between the workpieces. The values of contact resistance and power changes have been determined on the basis of preliminary experimental and theoretical investigations. The obtained results present the electric and temperature field distributions in the system. Special attention has been paid to the temperature evolution at specified observation points and lines in the contact area. The obtained information could be useful for clarification of the complicated nature of interrelated electric, thermal, mechanical, and physicochemical welding processes. Adequate modeling is also an opportunity for proper control and improvement of the system.

  12. Morphometric characterisation of wing feathers of the barn owl Tyto alba pratincola and the pigeon Columba livia

    Directory of Open Access Journals (Sweden)

    Klaas Michael

    2007-11-01

    description of the feathers and the specific structures of owl feathers can be used as a model for the construction of a biomimetic airplane wing or, in general, as a source for noise-reducing applications on any surfaces subjected to flow fields.

  13. Bier spots

    OpenAIRE

    Ahu Yorulmaz,; Seray Kulcu Cakmak; Esra Ar?; Ferda Artuz

    2015-01-01

    Also called as physiologic anemic macules, Bier spots are small, hypopigmented irregularly shaped macules against a background of diffuse erythema, which creates an appearance of speckled vascular mottling of the skin. Bier spots most commonly appear on distal portions of the limbs though there are case reports describing diffuse involvement, which also affect trunk and mucous membranes of the patient. Although the exact pathophysiological mechanisms underlying Bier spots still need to be elu...

  14. Light-Curve Diagnosis of a Hot Spot for Accretion-Disk Models

    OpenAIRE

    FUKUE, Jun

    2003-01-01

    Light curves of a hot spot rotating in a relativistic Keplerian disk were found to be periodic with typically two peaks, originating from a gravitational focusing effect and a Doppler boost. On the other hand, we found that light curves of a hot spot spirally infalling in a sub-Keplerian advective disk are aperiodic with typically a single peak, originating from a gravitational focusing effect or a Doppler boost. Such a difference in the light curves of a hot spot can discriminate background ...

  15. Stochastic price modeling of high volatility, mean-reverting, spike-prone commodities: The Australian wholesale spot electricity market

    International Nuclear Information System (INIS)

    Higgs, Helen; Worthington, Andrew

    2008-01-01

    It is commonly known that wholesale spot electricity markets exhibit high price volatility, strong mean-reversion and frequent extreme price spikes. This paper employs a basic stochastic model, a mean-reverting model and a regime-switching model to capture these features in the Australian national electricity market (NEM), comprising the interconnected markets of New South Wales, Queensland, South Australia and Victoria. Daily spot prices from 1 January 1999 to 31 December 2004 are employed. The results show that the regime-switching model outperforms the basic stochastic and mean-reverting models. Electricity prices are also found to exhibit stronger mean-reversion after a price spike than in the normal period, and price volatility is more than fourteen times higher in spike periods than in normal periods. The probability of a spike on any given day ranges between 5.16% in NSW and 9.44% in Victoria

  16. Charge and current orders in the spin-fermion model with overlapping hot spots

    Science.gov (United States)

    Volkov, Pavel A.; Efetov, Konstantin B.

    2018-04-01

    Experiments carried over the last years on the underdoped cuprates have revealed a variety of symmetry-breaking phenomena in the pseudogap state. Charge-density waves, breaking of C4 rotational symmetry as well as time-reversal symmetry breaking have all been observed in several cuprate families. In this regard, theoretical models where multiple nonsuperconducting orders emerge are of particular interest. We consider the recently introduced [Volkov and Efetov, Phys. Rev. B 93, 085131 (2016), 10.1103/PhysRevB.93.085131] spin-fermion model with overlapping `hot spots' on the Fermi surface. Focusing on the particle-hole instabilities we obtain a rich phase diagram with the chemical potential relative to the dispersion at (0 ,π );(π ,0 ) and the Fermi surface curvature in the antinodal regions being the control parameters. We find evidence for d-wave Pomeranchuk instability, d-form factor charge density waves, as well as commensurate and incommensurate staggered bond current phases similar to the d-density wave state. The current orders are found to be promoted by the curvature. Considering the appropriate parameter range for the hole-doped cuprates, we discuss the relation of our results to the pseudogap state and incommensurate magnetic phases of the cuprates.

  17. Geometry modeling of single track cladding deposited by high power diode laser with rectangular beam spot

    Science.gov (United States)

    Liu, Huaming; Qin, Xunpeng; Huang, Song; Hu, Zeqi; Ni, Mao

    2018-01-01

    This paper presents an investigation on the relationship between the process parameters and geometrical characteristics of the sectional profile for the single track cladding (STC) deposited by High Power Diode Laser (HPDL) with rectangle beam spot (RBS). To obtain the geometry parameters, namely cladding width Wc and height Hc of the sectional profile, a full factorial design (FFD) of experiment was used to conduct the experiments with a total of 27. The pre-placed powder technique has been employed during laser cladding. The influence of the process parameters including laser power, powder thickness and scanning speed on the Wc and Hc was analyzed in detail. A nonlinear fitting model was used to fit the relationship between the process parameters and geometry parameters. And a circular arc was adopted to describe the geometry profile of the cross-section of STC. The above models were confirmed by all the experiments. The results indicated that the geometrical characteristics of the sectional profile of STC can be described as the circular arc, and the other geometry parameters of the sectional profile can be calculated only using Wc and Hc. Meanwhile, the Wc and Hc can be predicted through the process parameters.

  18. Hot spot model of MagLIF implosions: Nernst term effect on magnetic flux losses

    Science.gov (United States)

    Garcia Rubio, Fernando; Sanz Recio, Javier; Betti, Riccardo

    2016-10-01

    An analytical model of a collisional plasma being compressed by a cylindrical liner is proposed and solved in a magnetized liner inertial fusion-like context. The implosion is assumed to be isobaric, and the magnetic diffusion is confined to a thin layer near the liner. Both unmagnetized and magnetized plasma cases are considered. The model reduces to a system of two partial differential equations for temperature and magnetic field. Special attention is given to the effect of the Nernst term on the evolution of the magnetic field. Scaling laws for temperature, magnetic field, hot spot mass increase and magnetic field losses are obtained. The temperature and magnetic field spatial profiles tend to a self-similar state. It is found that when the Nernst term is taken into account, the magnetic field is advected towards the liner, and the magnetic flux losses are independent of the magnetic Lewis number. Research supported by the Spanish Ministerio de Economía y Competitividad, Project No. ENE2014-54960R. Acknowledgements to the Laboratory of Laser Energetics (Rochester) for its hospitality.

  19. OWL Reasoning Framework over Big Biological Knowledge Network

    Science.gov (United States)

    Chen, Huajun; Chen, Xi; Gu, Peiqin; Wu, Zhaohui; Yu, Tong

    2014-01-01

    Recently, huge amounts of data are generated in the domain of biology. Embedded with domain knowledge from different disciplines, the isolated biological resources are implicitly connected. Thus it has shaped a big network of versatile biological knowledge. Faced with such massive, disparate, and interlinked biological data, providing an efficient way to model, integrate, and analyze the big biological network becomes a challenge. In this paper, we present a general OWL (web ontology language) reasoning framework to study the implicit relationships among biological entities. A comprehensive biological ontology across traditional Chinese medicine (TCM) and western medicine (WM) is used to create a conceptual model for the biological network. Then corresponding biological data is integrated into a biological knowledge network as the data model. Based on the conceptual model and data model, a scalable OWL reasoning method is utilized to infer the potential associations between biological entities from the biological network. In our experiment, we focus on the association discovery between TCM and WM. The derived associations are quite useful for biologists to promote the development of novel drugs and TCM modernization. The experimental results show that the system achieves high efficiency, accuracy, scalability, and effectivity. PMID:24877076

  20. Turbulent Spot Characterization and the Modeling of Transitional Heat Transfer in Turbines

    National Research Council Canada - National Science Library

    LaGraff, John

    2001-01-01

    .... The purpose of this research is to obtain more information on the generation. propagation and coalescence of turbulent spots in a transitional boundary layer and examine the effects of free stream turbulence pressure gradient and cross flow...

  1. Modeling Hot Spot Motor Vehicle Theft Crime in Relation to Landuse and Settlement Patterns

    Directory of Open Access Journals (Sweden)

    Djaka Marwasta

    2004-01-01

    Full Text Available The crowd of Yogyakarta urban has impacted its surrounding area, including Depok sub district, which is indicated by the rising of physical development, for example education facilities and settlements. The progress does not only bring positive impact, but also negative impact for instance the rising of crime number i.e. motor vehicle robbery. The aims of this research are 1 mapping motor vehicle robbery data as the distribution map and identifying motor vehicle robbery hot spot base on distrbution map; and 2 studying the correlation of motor vehicle robbery hot spot with physical environment phenomena, i.e. land use type and settlement pattern. The research method consists of two parts; they are motor vehicle robbery cluster analysis and the relation of motor vehicle robbery and physical environment analysis. Motor vehicle robbery cluster analysis is using distribution data, which analyzes the distribution into motor vehicle robbery hot spot with nearest neighbor tehnique. Contingency coefficient and frequency distribution analysis is used to analyze the correlation of motor vehicle robbery hot spot and physical environment. Contingency coefficient is used to study the relation of motor vehicle robbery hot spot polygon with physical environment condition, whereas frequency distribution is used to study the distribution of motor vehicle robbery in the hot spot with physical environment condition. Physical environment which consists of land use type, housing density, house regularity pattern, and the average of building size, are obtained from interpretation of black and white panchromatic aerial photograph year 2000, in the scale 1 : 20.000. the most motor vehicle robbery hot spot is found on the settlement area, 68,3% from 378 motor vehicle robbery cases in the hot spot. The seond level is found on the education area (16.4%. The most motor vehicle hot spot in the settlement is found on the hight density and irregular settlement, which have big

  2. A Model to Measure Tourist Preference toward Scenic Spots Based on Social Media Data: A Case of Dapeng in China

    Directory of Open Access Journals (Sweden)

    Yao Sun

    2017-12-01

    Full Text Available Research on tourist preference toward different tourism destinations has been a hot topic for decades in the field of tourism development. Tourist preference is mostly measured with small group opinion-based methods through introducing indicator systems in previous studies. In the digital age, e-tourism makes it possible to collect huge volumes of social data produced by tourists from the internet, to establish a new way of measuring tourist preference toward a close group of tourism destinations. This paper introduces a new model using social media data to quantitatively measure the market trend of a group of scenic spots from the angle of tourists’ demand, using three attributes: tourist sentiment orientation, present tourist market shares, and potential tourist awareness. Through data mining, cleaning, and analyzing with the framework of Machine Learning, the relative tourist preference toward 34 scenic spots closely located in the Dapeng Peninsula is calculated. The results not only provide a reliable “A-rating” system to gauge the popularity of different scenic spots, but also contribute an innovative measuring model to support scenic spots planning and policy making in the regional context.

  3. Spot markets vs. long-term contracts - modelling tools for regional electricity generating utilities

    International Nuclear Information System (INIS)

    Grohnheit, P.E.

    1999-01-01

    A properly organised market for electricity requires that some information will be available for all market participants. Also a range of generally available modelling tools are necessary. This paper describes a set of simple models based on published data for analyses of the long-term revenues of regional utilities with combined heat and power generation (CHP), who will operate a competitive international electricity market and a local heat market. The future revenues from trade on the spot market is analysed using a load curve model, in which marginal costs are calculated on the basis of short-term costs of the available units and chronological hourly variations in the demands for electricity and heat. Assumptions on prices, marginal costs and electricity generation by the different types of generating units are studied for selected types of local electricity generators. The long-term revenue requirements to be met by long-term contracts are analysed using a traditional techno-economic optimisation model focusing on technology choice and competition among technologies over 20.30 years. A possible conclusion from this discussion is that it is important for the economic and environmental efficiency of the electricity market that local or regional generators of CHP, who are able to react on price signals, do not conclude long-term contracts that include fixed time-of-day tariff for sale of electricity. Optimisation results for a CHP region (represented by the structure of the Danish electricity and CHP market in 1995) also indicates that a market for CO 2 tradable permits is unlikely to attract major non-fossil fuel technologies for electricity generation, e.g. wind power. (au)

  4. System Response Analysis of Rod Ejection Accident for APR1400 Using KNAP Hot Spot Model

    International Nuclear Information System (INIS)

    Kim, Yo-Han; Ha, Sang-Jun; Jun, Hwang-Yong

    2006-01-01

    Korea Electric Power Research Institute (KEPRI) has been developed the non-loss-of-coolant accident (non- LOCA) analysis methodology, called as the Korea Non- LOCA Analysis Package (KNAP), for the typical Optimized Power Reactor 1000 (OPR1000) plants. Considering current licensing methodology conducted by ABB-CE, however, the KNAP could be applied to Advanced Power Reactor 1400 (APR1400) also. In spite of some difference in design concepts of two plant types, there is a close resemblance between their nuclear steam supply systems (NSSS). So, in this study, the rod ejection accident (REA) event was analyzed using KNAP hot spot model (HSM) for APR1400 to estimate the feasibility of the application and the results were compared with those given in APR1400 Standard Safety Analysis Report (SSAR), which were calculated using the CESEC-III and STRIKIN-II code of ABB-CE. Through the study, it was concluded that the KNAP could be applicable to APR1400 on the view point of REA

  5. SU-D-BRE-03: Dosimetric Impact of In-Air Spot Size Variations for Commissioning a Room-Matched Beam Model for Pencil Beam Scanning Proton Therapy

    International Nuclear Information System (INIS)

    Zhang, Y; Giebeler, A; Mascia, A; Piskulich, F; Perles, L; Lepage, R; Dong, L

    2014-01-01

    Purpose: To quantitatively evaluate dosimetric consequence of spot size variations and validate beam-matching criteria for commissioning a pencil beam model for multiple treatment rooms. Methods: A planning study was first conducted by simulating spot size variations to systematically evaluate dosimetric impact of spot size variations in selected cases, which was used to establish the in-air spot size tolerance for beam matching specifications. A beam model in treatment planning system was created using in-air spot profiles acquired in one treatment room. These spot profiles were also acquired from another treatment room for assessing the actual spot size variations between the two treatment rooms. We created twenty five test plans with targets of different sizes at different depths, and performed dose measurement along the entrance, proximal and distal target regions. The absolute doses at those locations were measured using ionization chambers at both treatment rooms, and were compared against the calculated doses by the beam model. Fifteen additional patient plans were also measured and included in our validation. Results: The beam model is relatively insensitive to spot size variations. With an average of less than 15% measured in-air spot size variations between two treatment rooms, the average dose difference was −0.15% with a standard deviation of 0.40% for 55 measurement points within target region; but the differences increased to 1.4%±1.1% in the entrance regions, which are more affected by in-air spot size variations. Overall, our single-room based beam model in the treatment planning system agreed with measurements in both rooms < 0.5% within the target region. For fifteen patient cases, the agreement was within 1%. Conclusion: We have demonstrated that dosimetrically equivalent machines can be established when in-air spot size variations are within 15% between the two treatment rooms

  6. Extraocular muscle architecture in hawks and owls.

    Science.gov (United States)

    Plochocki, Jeffrey H; Segev, Tamar; Grow, Wade; Hall, Margaret I

    2018-02-06

    A complete and accurate understanding of extraocular muscle function is important to the veterinary care of the avian eye. This is especially true for birds of prey, which rely heavily on vision for survival and yet are prone to ocular injury and disease. To better understand the function of extraocular muscles in birds of prey, we studied extraocular muscle architecture grossly and histologically. This sample was composed of two each of the following species: red-tailed hawk (Buteo jamaicensis), Harris's hawk (Parabuteo unicinctus), great horned owl (Bubo virginianus), and barn owl (Tyto alba). All extraocular muscles were dissected and weighed. To analyze muscle fiber architecture, the superior oblique and quadratus muscles were dissected, weighed, and sectioned at 5 μm thickness in the transverse plane. We calculated the physiologic cross-sectional area and the ratio of muscle mass to predicted effective maximum tetanic tension. Hawk and owl extraocular muscles exhibit significant physiological differences that play roles in ocular movements and closure of the nictitating membrane. Owls, which do not exhibit extraocular movement, have muscle architecture suited to stabilize the position of a massive, tubular eye that protrudes significantly from the orbit. Hawks, which have a more globose eye that is largely contained within the orbit, do not require as much muscular stability and instead have muscle architecture that facilitates rapid eye movement. © 2018 American College of Veterinary Ophthalmologists.

  7. 3D modelling of plug failure in resistance spot welded shear-lab specimens (DP600-steel)

    DEFF Research Database (Denmark)

    Nielsen, Kim Lau

    2008-01-01

    are based on uni-axial tensile testing of the basis material, while the modelled tensile response of the shear-lab specimens is compared to experimental results for the case of a ductile failure near the heat affected zone (HAZ). A parametric study for a range of weld diameters is carried out, which makes......Ductile plug failure of resistance spot welded shear-lab specimens is studied by full 3D finite element analysis, using an elastic-viscoplastic constitutive relation that accounts for nucleation and growth of microvoids to coalescence (The Gurson model). Tensile properties and damage parameters...... it possible to numerically relate the weld diameter to the tensile shear force (TSF) and the associated displacement, u (TSF) , respectively. Main focus in the paper is on modelling the localization of plastic flow and the corresponding damage development in the vicinity of the spot weld, near the HAZ...

  8. Owl's eye appearance: a case report

    International Nuclear Information System (INIS)

    Mathur, Mukul; Asha, P.

    2010-01-01

    Full text: Hyper-functioning thyroid nodule may present various scintigraphic appearances on thyroid scans. Autonomously hyper functioning thyroid nodules often show degenerative changes. These changes may give rise to peripheral photopenic areas on a thyroid scan. In this report we present a case of hyper functioning nodule showing appearance of an owl's eye. Although rare, such pattern can be seen in a variety of benign and malignant thyroid conditions. A 42-year-old man presented with a solitary thyroid nodule in the right lobe and weight loss for four months. The thyroid hormone profile confirmed hyperthyroidism. Thyroid function testing revealed T4=136.8 nmol/l (Normal = 66.0-181.0 nmol/L) and Thyroid Stimulating Hormone (TSH) = 0.283 (Normal =0.27- 4.2 μIU/ml). Antithyroglobulin antibodies and antimicrosmal antibodies were negative. The patient was referred for thyroid scan and uptake. A Thyroid scan was obtained after the intravenous injection of 5 mCi (185MBq) of 99m Tc pertechnetate. Anterior view obtained using a parallel hole collimator. The scan showed peripheral photopenic area with a central focal area of increased uptake giving the appearance of 'Owl's eye'. 99m Tc-pertechnetate uptake was increased. A scintigraphic 'Owl's eye' sign has been described in thyroid cyst, benign autonomous nodule and papillary carcinoma of the thyroid gland. This Owl's eye pattern appears to be caused by a focus of functioning tissue overlapping a large cold area in a nodule that has cystic,degenerative and necrotic changes in the middle of a benign and malignant pathology. Hyper functioning nodules may scintigraphically show Owl's eye pattern due to intra nodular degeneration, with residual hyper functioning tissue within or overlapping the degenerative area

  9. Comparison of the Diet of Two Desert-living Owls, the Long-eared Owl ( Asio otus and Little Owl ( Athene noctua from Southern Mongolia

    Directory of Open Access Journals (Sweden)

    Dawn M. Scott

    2005-06-01

    Full Text Available The diet of two sympatric owl species, the long-eared owl ( Asio otus and the little owl ( Athene noctua was investigated in an arid area of southern Mongolia using pellet analysis. In total 334 pellets of long-eared owl and 52 pellets of little owl were analysed, revealing the presence of five small mammal species (Dipodidae, three Muridae and one Soricidae, small birds and invertebrate fragments. Accumulative composition plots indicated a batch size of 35 - 60 pellets was sufficient to reveal representative diet composition. Small mammals comprised the largest component of the diet of long- eared owls with four species recorded, Phodopus was the most frequently occurring (85 %, followed by Meriones (33 %. Bird and invertebrate remains were also found in long-eared owl pellets but comprised less than 2 %. In contrast, invertebrates were the highest occurring component of the diet of little owls (35 %, with small mammals occurring in only 40 % of pellets. Meriones was the most frequently recorded small mammal in little owl pellets (23 % and contributed the greatest in terms of overall rodent biomass. There was a highly statistically significant difference in the diet of the two species (÷ 2 = 2043, d.f. = 4, P < 0.001. Levin’s measure of niche breadth was greater for little owls (0.71 than long-eared owls (0.51, but overall the two species had low niche overlap using Levin’s index (0.22. These results are discussed in relation to previous findings of these two species.

  10. Analytical modeling of the temporal evolution of hot spot temperatures in silicon solar cells

    Science.gov (United States)

    Wasmer, Sven; Rajsrima, Narong; Geisemeyer, Ino; Fertig, Fabian; Greulich, Johannes Michael; Rein, Stefan

    2018-03-01

    We present an approach to predict the equilibrium temperature of hot spots in crystalline silicon solar cells based on the analysis of their temporal evolution right after turning on a reverse bias. For this end, we derive an analytical expression for the time-dependent heat diffusion of a breakdown channel that is assumed to be cylindrical. We validate this by means of thermography imaging of hot spots right after turning on a reverse bias. The expression allows to be used to extract hot spot powers and radii from short-term measurements, targeting application in inline solar cell characterization. The extracted hot spot powers are validated at the hands of long-term dark lock-in thermography imaging. Using a look-up table of expected equilibrium temperatures determined by numerical and analytical simulations, we utilize the determined hot spot properties to predict the equilibrium temperatures of about 100 industrial aluminum back-surface field solar cells and achieve a high correlation coefficient of 0.86 and a mean absolute error of only 3.3 K.

  11. Bier spots

    Directory of Open Access Journals (Sweden)

    Ahu Yorulmaz,

    2015-10-01

    Full Text Available Also called as physiologic anemic macules, Bier spots are small, hypopigmented irregularly shaped macules against a background of diffuse erythema, which creates an appearance of speckled vascular mottling of the skin. Bier spots most commonly appear on distal portions of the limbs though there are case reports describing diffuse involvement, which also affect trunk and mucous membranes of the patient. Although the exact pathophysiological mechanisms underlying Bier spots still need to be elucidated, Bier spots have been suggested to be a vascular anomaly caused by vasoconstriction of small vessels. In addition, several diseases have been proposed to be associated with Bier spots, including scleroderma renal crisis, cryoglobulinemia, Peutz-Jeghers syndrome, alopecia areata and hypoplasia of the aorta, although it has not been shown whether these associations are casual or coincidental. The clinical presentation of Bier spots is quite typical. These tiny whitish macules easily become prominent when the affected limb is placed in a dependent position and fade away when the limb is raised. Here we report a case of Bier spots in a 32-year-old male patient with characteristical clinical manifestations.

  12. Optimal Prediction of Moving Sound Source Direction in the Owl.

    Directory of Open Access Journals (Sweden)

    Weston Cox

    2015-07-01

    Full Text Available Capturing nature's statistical structure in behavioral responses is at the core of the ability to function adaptively in the environment. Bayesian statistical inference describes how sensory and prior information can be combined optimally to guide behavior. An outstanding open question of how neural coding supports Bayesian inference includes how sensory cues are optimally integrated over time. Here we address what neural response properties allow a neural system to perform Bayesian prediction, i.e., predicting where a source will be in the near future given sensory information and prior assumptions. The work here shows that the population vector decoder will perform Bayesian prediction when the receptive fields of the neurons encode the target dynamics with shifting receptive fields. We test the model using the system that underlies sound localization in barn owls. Neurons in the owl's midbrain show shifting receptive fields for moving sources that are consistent with the predictions of the model. We predict that neural populations can be specialized to represent the statistics of dynamic stimuli to allow for a vector read-out of Bayes-optimal predictions.

  13. Comparison of Food Habits of the Northern Saw-whet Owl (Aegolius acadicus) and the Western Screech-owl (Otus kennicottii) in Southwestern Idaho

    Science.gov (United States)

    Charlotte Rains

    1997-01-01

    I compared the breeding-season diets of Northern Saw-whet Owls (Aegolius acadicus) and Western Screech-owls (Otus kennicottii). Prey items were obtained from regurgitated pellets collected from saw-whet owl and screech-owl nests found in nest boxes in the Snake River Birds of Prey National Conservation Area in southwestern Idaho....

  14. MODELADO DEL PRECIO SPOT DE LA ELECTRICIDAD EN BRASIL USANDO UNA RED NEURONAL AUTORREGRESIVA ELECTRICITY SPOT PRICE MODELLING IN BRASIL USING AN AUTOREGRESSIVE NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    Juan D Velásquez

    2008-12-01

    Full Text Available Una red neuronal autorregresiva es estimada para el precio mensual brasileño de corto plazo de la electricidad, la cual describe mejor la dinámica de los precios que un modelo lineal autorregresivo y que un perceptrón multicapa clásico que usan las mismas entradas y neuronas en la capa oculta. El modelo propuesto es especificado usando un procedimiento estadístico basado en el contraste del radio de verosimilitud. El modelo pasa una batería de pruebas de diagnóstico. El procedimiento de especificación propuesto permite seleccionar el número de unidades en la capa oculta y las entradas a la red neuronal, usando pruebas estadísticas que tienen en cuenta la cantidad de los datos y el ajuste del modelo a la serie de precios. La especificación del modelo final demuestra que el precio para el próximo mes es una función no lineal del precio actual, de la energía afluente actual y de la energía almacenada en el embalse equivalente en el mes actual y dos meses atrás.An autoregressive neural network model is estimated for the monthly Brazilian electricity spot price, which describes the prices dynamics better than a linear autoregressive model and a classical multilayer perceptron using the same input and neurons in the hidden layer. The proposed model is specified using a statistical procedure based on a likelihood ratio test. The model passes a battery of diagnostic tests. The proposed specification procedure allows us to select the number of units in hidden layer and the inputs to the neural network based on statistical tests, taking into account the number of data and the model fitting to the price time series. The final model specification demonstrates that the price for the next month is a nonlinear function of the current price, the current energy inflow, and the energy saved in the equivalent reservoir in the current month and two months ago.

  15. Age Spots

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Age Spots Treatment Options Learn more about treatment ...

  16. Spotted inflation

    International Nuclear Information System (INIS)

    Matsuda, Tomohiro

    2010-01-01

    We describe new scenarios for generating curvature perturbations when inflaton (curvaton) has significant interactions. We consider a ''spot'', which arises from interactions associated with an enhanced symmetric point (ESP) on the trajectory. Our first example uses the spot to induce a gap in the field equation. We observe that the gap in the field equation may cause generation of curvature perturbation if it does not appear simultaneous in space. The mechanism is similar to the scenario of inhomogeneous phase transition. Then we observe that the spot interactions may initiate warm inflation in the cold Universe. Creation of cosmological perturbation is discussed in relation to the inflaton dynamics and the modulation associated with the spot interactions

  17. Energy stability of droplets and dry spots in a thin film model of hanging drops

    Science.gov (United States)

    Cheung, Ka-Luen; Chou, Kai-Seng

    2017-10-01

    The 2-D thin film equation describing the evolution of hang drops is studied. All radially symmetric steady states are classified, and their energy stability is determined. It is shown that the droplet with zero contact angle is the only global energy minimizer and the dry spot with zero contact angle is a strict local energy minimizer.

  18. Does petroleum development affect burrowing owl nocturnal space-use?

    Energy Technology Data Exchange (ETDEWEB)

    Scobie, Corey; Wellicome, Troy; Bayne, Erin [Department of Biological Sciences, University of Alberta (Canada)], email: cscobie@ualberta.ca, email: tiw@ualberta.ca, email: bayne@ualberta.ca

    2011-07-01

    Decline all over Canada in the population of burrowing owls, a federally listed endangered species, has raised concerns about the possible influence of petroleum infrastructure development on owl nocturnal space-use while foraging. Roads, wells, pipelines and sound-producing facilities related to petroleum development change the landscape and can influence the owls' mortality risk. For 3 years, 27 breeding adult male burrowing owls with nests close to different petroleum infrastructures were captured and fitted with a miniature GPS datalogger in order to track their nocturnal foraging. Data from these GPS devices were fed into a geographical information system and showed that pipelines and wells did not alter the foraging habits of the owls. Dirt and gravel roads, with little traffic, were preferentially selected by the owls, conceivably because of higher owl mortality risk along paved roads. Sound-producing facilities did not change owls' foraging behaviour, implying that sound may not affect their nocturnal space-use. Traffic data and sound power measurements will be used in further studies in an effort to better understand burrowing owls' nocturnal foraging habits.

  19. A dry-spot model for the prediction of critical heat flux in water boiling in bubbly flow regime

    International Nuclear Information System (INIS)

    Ha, Sang Jun; No, Hee Cheon

    1997-01-01

    This paper presents a prediction of critical heat flux (CHF) in bubbly flow regime using dry-spot model proposed recently by authors for pool and flow boiling CHF and existing correlations for forced convective heat transfer coefficient, active site density and bubble departure diameter in nucleate boiling region. Without any empirical constants always present in earlier models, comparisons of the model predictions with experimental data for upward flow of water in vertical, uniformly-heated round tubes are performed and show a good agreement. The parametric trends of CHF have been explored with respect to variation in pressure, tube diameter and length, mass flux and inlet subcooling

  20. OWL-based reasoning methods for validating archetypes.

    Science.gov (United States)

    Menárguez-Tortosa, Marcos; Fernández-Breis, Jesualdo Tomás

    2013-04-01

    Some modern Electronic Healthcare Record (EHR) architectures and standards are based on the dual model-based architecture, which defines two conceptual levels: reference model and archetype model. Such architectures represent EHR domain knowledge by means of archetypes, which are considered by many researchers to play a fundamental role for the achievement of semantic interoperability in healthcare. Consequently, formal methods for validating archetypes are necessary. In recent years, there has been an increasing interest in exploring how semantic web technologies in general, and ontologies in particular, can facilitate the representation and management of archetypes, including binding to terminologies, but no solution based on such technologies has been provided to date to validate archetypes. Our approach represents archetypes by means of OWL ontologies. This permits to combine the two levels of the dual model-based architecture in one modeling framework which can also integrate terminologies available in OWL format. The validation method consists of reasoning on those ontologies to find modeling errors in archetypes: incorrect restrictions over the reference model, non-conformant archetype specializations and inconsistent terminological bindings. The archetypes available in the repositories supported by the openEHR Foundation and the NHS Connecting for Health Program, which are the two largest publicly available ones, have been analyzed with our validation method. For such purpose, we have implemented a software tool called Archeck. Our results show that around 1/5 of archetype specializations contain modeling errors, the most common mistakes being related to coded terms and terminological bindings. The analysis of each repository reveals that different patterns of errors are found in both repositories. This result reinforces the need for making serious efforts in improving archetype design processes. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Technical Note: Validation of halo modeling for proton pencil beam spot scanning using a quality assurance test pattern

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Liyong, E-mail: linl@uphs.upenn.edu; Huang, Sheng; Kang, Minglei; Solberg, Timothy D.; McDonough, James E.; Ainsley, Christopher G. [Department of Radiation Oncology, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania 19104 (United States)

    2015-09-15

    Purpose: The purpose of this paper is to demonstrate the utility of a comprehensive test pattern in validating calculation models that include the halo component (low-dose tails) of proton pencil beam scanning (PBS) spots. Such a pattern has been used previously for quality assurance purposes to assess spot shape, position, and dose. Methods: In this study, a scintillation detector was used to measure the test pattern in air at isocenter for two proton beam energies (115 and 225 MeV) of two IBA universal nozzles (UN #1 and UN #2). Planar measurements were compared with calculated dose distributions based on the weighted superposition of location-independent (UN #1) or location-dependent (UN #2) spot profiles, previously measured using a pair-magnification method and between two nozzles. Results: Including the halo component below 1% of the central dose is shown to improve the gamma-map comparison between calculation and measurement from 94.9% to 98.4% using 2 mm/2% criteria for the 115 MeV proton beam of UN #1. In contrast, including the halo component below 1% of the central dose does not improve the gamma agreement for the 115 MeV proton beam of UN #2, due to the cutoff of the halo component at off-axis locations. When location-dependent spot profiles are used for calculation instead of spot profiles at central axis, the gamma agreement is improved from 98.0% to 99.5% using 2 mm/2% criteria. The two nozzles clearly have different characteristics, as a direct comparison of measured data shows a passing rate of 89.7% for the 115 MeV proton beam. At 225 MeV, the corresponding gamma comparisons agree better between measurement and calculation, and between measurements in the two nozzles. Conclusions: In addition to confirming the primary component of individual PBS spot profiles, a comprehensive test pattern is useful for the validation of the halo component at off-axis locations, especially for low energy protons.

  2. Inferring ontology graph structures using OWL reasoning

    KAUST Repository

    Rodriguez-Garcia, Miguel Angel

    2018-01-05

    Ontologies are representations of a conceptualization of a domain. Traditionally, ontologies in biology were represented as directed acyclic graphs (DAG) which represent the backbone taxonomy and additional relations between classes. These graphs are widely exploited for data analysis in the form of ontology enrichment or computation of semantic similarity. More recently, ontologies are developed in a formal language such as the Web Ontology Language (OWL) and consist of a set of axioms through which classes are defined or constrained. While the taxonomy of an ontology can be inferred directly from the axioms of an ontology as one of the standard OWL reasoning tasks, creating general graph structures from OWL ontologies that exploit the ontologies\\' semantic content remains a challenge.We developed a method to transform ontologies into graphs using an automated reasoner while taking into account all relations between classes. Searching for (existential) patterns in the deductive closure of ontologies, we can identify relations between classes that are implied but not asserted and generate graph structures that encode for a large part of the ontologies\\' semantic content. We demonstrate the advantages of our method by applying it to inference of protein-protein interactions through semantic similarity over the Gene Ontology and demonstrate that performance is increased when graph structures are inferred using deductive inference according to our method. Our software and experiment results are available at http://github.com/bio-ontology-research-group/Onto2Graph .Onto2Graph is a method to generate graph structures from OWL ontologies using automated reasoning. The resulting graphs can be used for improved ontology visualization and ontology-based data analysis.

  3. Inferring ontology graph structures using OWL reasoning.

    Science.gov (United States)

    Rodríguez-García, Miguel Ángel; Hoehndorf, Robert

    2018-01-05

    Ontologies are representations of a conceptualization of a domain. Traditionally, ontologies in biology were represented as directed acyclic graphs (DAG) which represent the backbone taxonomy and additional relations between classes. These graphs are widely exploited for data analysis in the form of ontology enrichment or computation of semantic similarity. More recently, ontologies are developed in a formal language such as the Web Ontology Language (OWL) and consist of a set of axioms through which classes are defined or constrained. While the taxonomy of an ontology can be inferred directly from the axioms of an ontology as one of the standard OWL reasoning tasks, creating general graph structures from OWL ontologies that exploit the ontologies' semantic content remains a challenge. We developed a method to transform ontologies into graphs using an automated reasoner while taking into account all relations between classes. Searching for (existential) patterns in the deductive closure of ontologies, we can identify relations between classes that are implied but not asserted and generate graph structures that encode for a large part of the ontologies' semantic content. We demonstrate the advantages of our method by applying it to inference of protein-protein interactions through semantic similarity over the Gene Ontology and demonstrate that performance is increased when graph structures are inferred using deductive inference according to our method. Our software and experiment results are available at http://github.com/bio-ontology-research-group/Onto2Graph . Onto2Graph is a method to generate graph structures from OWL ontologies using automated reasoning. The resulting graphs can be used for improved ontology visualization and ontology-based data analysis.

  4. Geographical assemblages of European raptors and owls

    Science.gov (United States)

    López-López, Pascual; Benavent-Corai, José; García-Ripollés, Clara

    2008-09-01

    In this work we look for geographical structure patterns in European raptors (Order: Falconiformes) and owls (Order: Strigiformes). For this purpose we have conducted our research using freely available tools such as statistical software and databases. To perform the study, presence-absence data for the European raptors and owl species (Class Aves) were downloaded from the BirdLife International website. Using the freely available "pvclust" R-package, we applied similarity Jaccard index and cluster analysis in order to delineate biogeographical relationships for European countries. According to the cluster of similarity, we found that Europe is structured into two main geographical assemblages. The larger length branch separated two main groups: one containing Iceland, Greenland and the countries of central, northern and northwestern Europe, and the other group including the countries of eastern, southern and southwestern Europe. Both groups are divided into two main subgroups. According to our results, the European raptors and owls could be considered structured into four meta-communities well delimited by suture zones defined by Remington (1968) [Remington, C.L., 1968. Suture-zones of hybrid interaction between recently joined biotas. Evol. Biol. 2, 321-428]. Climatic oscillations during the Quaternary Ice Ages could explain at least in part the modern geographical distribution of the group.

  5. Time-series photometric spot modeling. I - Parameter study and application to HD 17433 = VY Arietis

    Science.gov (United States)

    Strassmeier, K. G.; Bopp, B. W.

    1992-01-01

    New UBVRI photometry of the active chromosphere binary HD 17433 (VY) Ari from 1987 through 1991 is presented, and the long-term and short-term spot behavior is studied. A 0.2 mag variation of the mean brightness and a maximum wave amplitude of up to 0.4 mag in 1988 are found. The newly measured photometric period of 16.42 d suggests asynchronous rotation of the primary component by about 30 percent.

  6. A dry-spot model of critical heat flux and transition boiling in pool and subcooled forced convection boiling

    International Nuclear Information System (INIS)

    Ha, Sang Jun

    1998-02-01

    A new dry-spot model for critical heat flux (CHF) is proposed. The new concept for dry area formation based on Poisson distribution of active nucleation sites and the critical active site number is introduced. The model is based on the boiling phenomena observed in nucleate boiling such as Poisson distribution of active nucleation sites and formation of dry spots on the heating surface. It is hypothesized that when the number of bubbles surrounding one bubble exceeds a critical number, the surrounding bubbles restrict the feed of liquid to the microlayer under the bubble. Then a dry spot of vapor will form on the heated surface. As the surface temperature is raised, more and more bubbles will have a population of surrounding active sites over the critical number. Consequently, the number of the spots will increase and the size of dry areas will increase due to merger of several dry spots. If this trend continues, the number of effective sites for heat transport through the wall will diminish, and CHF and transition boiling occur. The model is applicable to pool and subcooled forced convection boiling conditions, based on the common mechanism that CHF and transition boiling are caused by the accumulation and coalescences of dry spots. It is shown that CHF and heat flux in transition boiling can be determined without any empirical parameter based on information on the boiling parameters such as active site density and bubble diameter, etc., in nucleate boiling. It is also shown that the present model well represents actual phenomena on CHF and transition boiling and explains the mechanism on how parameters such as flow modes (pool or flow) and surface wettability influence CHF and transition boiling. Validation of the present model for CHF and transition boiling is achieved without any tuning parameter always present in earlier models. It is achieved by comparing the predictions of CHF and heat flux in transition boiling using measured boiling parameters in nucleate

  7. Owl: A General-Purpose Numerical Library in OCaml

    OpenAIRE

    Wang, Liang

    2017-01-01

    Owl is a new numerical library developed in the OCaml language. It focuses on providing a comprehensive set of high-level numerical functions so that developers can quickly build up data analytical applications. In this abstract, we will present Owl's design, core components, and its key functionality.

  8. Flammulated Owls (Otus flammeolus) breeding in deciduous forests

    Science.gov (United States)

    Carl D. Marti

    1997-01-01

    The first studies of nesting Flammulated Owls (Otus flammeolus) established the idea that the species needs ponderosa pine (Pinus ponderosa) forests for breeding. In northern Utah, Flammulated Owls nested in montane deciduous forests dominated by quaking aspen (Populus tremuloides). No pines were present but...

  9. in the diet of Verreaux's Eagle Owl Bubo lacteus

    African Journals Online (AJOL)

    two different species from the family Molossidae, and one individual of Lander's. Horseshoe Bat Rhinolophus landeri (Rhinolophidae). Bats are common prey items of owls, not surprising considering that both these animal groups are nocturnal (Marks et al. 1999). However, the proportion of bats in owls' diets varies between ...

  10. Predator facilitation or interference: a game of vipers and owls.

    Science.gov (United States)

    Embar, Keren; Raveh, Ashael; Hoffmann, Ishai; Kotler, Burt P

    2014-04-01

    In predator-prey foraging games, the prey's reaction to one type of predator may either facilitate or hinder the success of another predator. We ask, do different predator species affect each other's patch selection? If the predators facilitate each other, they should prefer to hunt in the same patch; if they interfere, they should prefer to hunt alone. We performed an experiment in a large outdoor vivarium where we presented barn owls (Tyto alba) with a choice of hunting greater Egyptian gerbils (Gerbillus pyramidum) in patches with or without Saharan horned vipers (Cerastes cerastes). Gerbils foraged on feeding trays set under bushes or in the open. We monitored owl location, activity, and hunting attempts, viper activity and ambush site location, and the foraging behavior of the gerbils in bush and open microhabitats. Owls directed more attacks towards patches with vipers, and vipers were more active in the presence of owls. Owls and vipers facilitated each other's hunting through their combined effect on gerbil behavior, especially on full moon nights when vipers are more active. Owls forced gerbils into the bushes where vipers preferred to ambush, while viper presence chased gerbils into the open where they were exposed to owls. Owls and vipers took advantage of their indirect positive effect on each other. In the foraging game context, they improve each other's patch quality and hunting success.

  11. Protozoal hepatitis in a western burrowing owl (Athene cunicularia hypugaea)

    Science.gov (United States)

    Franson, J. Christian

    2017-01-01

    A western burrowing owl (Athene cunicularia hypugaea) found dead in southern California had many light-colored lesions visible grossly on its liver, and histopathology revealed extensive necrosis throughout the hepatic parenchyma. Single-celled organisms were seen in clear spaces within the areas of necrosis. The owl was diagnosed with protozoal hepatitis.

  12. The Spotting Distribution of Wildfires

    Directory of Open Access Journals (Sweden)

    Jonathan Martin

    2016-06-01

    Full Text Available In wildfire science, spotting refers to non-local creation of new fires, due to downwind ignition of brands launched from a primary fire. Spotting is often mentioned as being one of the most difficult problems for wildfire management, because of its unpredictable nature. Since spotting is a stochastic process, it makes sense to talk about a probability distribution for spotting, which we call the spotting distribution. Given a location ahead of the fire front, we would like to know how likely is it to observe a spot fire at that location in the next few minutes. The aim of this paper is to introduce a detailed procedure to find the spotting distribution. Most prior modelling has focused on the maximum spotting distance, or on physical subprocesses. We will use mathematical modelling, which is based on detailed physical processes, to derive a spotting distribution. We discuss the use and measurement of this spotting distribution in fire spread, fire management and fire breaching. The appendix of this paper contains a comprehensive review of the relevant underlying physical sub-processes of fire plumes, launching fire brands, wind transport, falling and terminal velocity, combustion during transport, and ignition upon landing.

  13. Comparison of extended mean-reversion and time series models for electricity spot price simulation considering negative prices

    International Nuclear Information System (INIS)

    Keles, Dogan; Genoese, Massimo; Möst, Dominik; Fichtner, Wolf

    2012-01-01

    This paper evaluates different financial price and time series models, such as mean reversion, autoregressive moving average (ARMA), integrated ARMA (ARIMA) and general autoregressive conditional heteroscedasticity (GARCH) process, usually applied for electricity price simulations. However, as these models are developed to describe the stochastic behaviour of electricity prices, they are extended by a separate data treatment for the deterministic components (trend, daily, weekly and annual cycles) of electricity spot prices. Furthermore price jumps are considered and implemented within a regime-switching model. Since 2008 market design allows for negative prices at the European Energy Exchange, which also occurred for several hours in the last years. Up to now, only a few financial and time series approaches exist, which are able to capture negative prices. This paper presents a new approach incorporating negative prices. The evaluation of the different approaches presented points out that the mean reversion and the ARMA models deliver the lowest mean root square error between simulated and historical electricity spot prices gained from the European Energy Exchange. These models posses also lower mean average errors than GARCH models. Hence, they are more suitable to simulate well-fitting price paths. Furthermore it is shown that the daily structure of historical price curves is better captured applying ARMA or ARIMA processes instead of mean-reversion or GARCH models. Another important outcome of the paper is that the regime-switching approach and the consideration of negative prices via the new proposed approach lead to a significant improvement of the electricity price simulation. - Highlights: ► Considering negative prices improves the results of time-series and financial models for electricity prices. ► Regime-switching approach captures the jumps and base prices quite well. ► Removing and separate modelling of deterministic annual, weekly and daily

  14. Increase in distribution records of owl species in Manitoba based on a volunteer nocturnal survey using Boreal Owl (Aegolius funereus) and Great Gray Owl (Strix nebulosa) playback

    Science.gov (United States)

    James R. Duncan; Patricia A. Duncan

    1997-01-01

    From 1991 through 1995, extensive owl surveys were conducted in late March and early April in Manitoba. Prior to these surveys, distribution records of owls covered only 16-71 per cent of their expected range in Manitoba. The degree to which the survey increased the documented range varied from no increase (6 of 12 species) up to an 88 per cent increase for the...

  15. OWLS as platform technology in OPTOS satellite

    Science.gov (United States)

    Rivas Abalo, J.; Martínez Oter, J.; Arruego Rodríguez, I.; Martín-Ortega Rico, A.; de Mingo Martín, J. R.; Jiménez Martín, J. J.; Martín Vodopivec, B.; Rodríguez Bustabad, S.; Guerrero Padrón, H.

    2017-12-01

    The aim of this work is to show the Optical Wireless Link to intraSpacecraft Communications (OWLS) technology as a platform technology for space missions, and more specifically its use within the On-Board Communication system of OPTOS satellite. OWLS technology was proposed by Instituto Nacional de Técnica Aeroespacial (INTA) at the end of the 1990s and developed along 10 years through a number of ground demonstrations, technological developments and in-orbit experiments. Its main benefits are: mass reduction, flexibility, and simplification of the Assembly, Integration and Tests phases. The final step was to go from an experimental technology to a platform one. This step was carried out in the OPTOS satellite, which makes use of optical wireless links in a distributed network based on an OLWS implementation of the CAN bus. OPTOS is the first fully wireless satellite. It is based on the triple configuration (3U) of the popular Cubesat standard, and was completely built at INTA. It was conceived to procure a fast development, low cost, and yet reliable platform to the Spanish scientific community, acting as a test bed for space born science and technology. OPTOS presents a distributed OBDH architecture in which all satellite's subsystems and payloads incorporate a small Distributed On-Board Computer (OBC) Terminal (DOT). All DOTs (7 in total) communicate between them by means of the OWLS-CAN that enables full data sharing capabilities. This collaboration allows them to perform all tasks that would normally be carried out by a centralized On-Board Computer.

  16. Porcine skin visible lesion thresholds for near-infrared lasers including modeling at two pulse durations and spot sizes.

    Science.gov (United States)

    Cain, C P; Polhamus, G D; Roach, W P; Stolarski, D J; Schuster, K J; Stockton, K L; Rockwell, B A; Chen, Bo; Welch, A J

    2006-01-01

    With the advent of such systems as the airborne laser and advanced tactical laser, high-energy lasers that use 1315-nm wavelengths in the near-infrared band will soon present a new laser safety challenge to armed forces and civilian populations. Experiments in nonhuman primates using this wavelength have demonstrated a range of ocular injuries, including corneal, lenticular, and retinal lesions as a function of pulse duration. American National Standards Institute (ANSI) laser safety standards have traditionally been based on experimental data, and there is scant data for this wavelength. We are reporting minimum visible lesion (MVL) threshold measurements using a porcine skin model for two different pulse durations and spot sizes for this wavelength. We also compare our measurements to results from our model based on the heat transfer equation and rate process equation, together with actual temperature measurements on the skin surface using a high-speed infrared camera. Our MVL-ED50 thresholds for long pulses (350 micros) at 24-h postexposure are measured to be 99 and 83 J cm(-2) for spot sizes of 0.7 and 1.3 mm diam, respectively. Q-switched laser pulses of 50 ns have a lower threshold of 11 J cm(-2) for a 5-mm-diam top-hat laser pulse.

  17. Experimental analysis and modeling of the IV characteristics of photovoltaic solar cells under solar spectrum spot illumination

    Energy Technology Data Exchange (ETDEWEB)

    Munji, M.K., E-mail: mathew.munji@nmmu.ac.z [Department of Physics, Nelson Mandela Metropolitan University, PO Box 7700 Port Elizabeth 6031 (South Africa); Dyk, E.E. van; Vorster, F.J. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 7700 Port Elizabeth 6031 (South Africa)

    2009-12-01

    In this paper, some models that have been put forward to explain the characteristics of a photovoltaic solar cell device under solar spot-illumination are investigated. In the experimental procedure, small areas of the cell were selected and illuminated at different solar intensities. The solar cell open circuit voltage (V{sub oc}) and short circuit current (I{sub sc}) obtained at different illumination intensities was used to determine the solar cell ideality factor. By varying the illuminated area on the solar cell, changes in the ideality factor were studied. The ideality factor obtained increases with decreasing illumination surface ratio. The photo-generated current at the illuminated part of the cell is assumed to act as a dc source that injects charge carriers into the p-n junction of the whole solar cell while the dark region of the solar cell operates in a low space charge recombination regime with small diffusion currents. From this analysis, a different model of a spot illuminated cell that uses the variation of ideality factor with the illuminated area is proposed.

  18. Experimental analysis and modeling of the IV characteristics of photovoltaic solar cells under solar spectrum spot illumination

    International Nuclear Information System (INIS)

    Munji, M.K.; Dyk, E.E. van; Vorster, F.J.

    2009-01-01

    In this paper, some models that have been put forward to explain the characteristics of a photovoltaic solar cell device under solar spot-illumination are investigated. In the experimental procedure, small areas of the cell were selected and illuminated at different solar intensities. The solar cell open circuit voltage (V oc ) and short circuit current (I sc ) obtained at different illumination intensities was used to determine the solar cell ideality factor. By varying the illuminated area on the solar cell, changes in the ideality factor were studied. The ideality factor obtained increases with decreasing illumination surface ratio. The photo-generated current at the illuminated part of the cell is assumed to act as a dc source that injects charge carriers into the p-n junction of the whole solar cell while the dark region of the solar cell operates in a low space charge recombination regime with small diffusion currents. From this analysis, a different model of a spot illuminated cell that uses the variation of ideality factor with the illuminated area is proposed.

  19. A dry-spot model for the prediction of critical heat flux in water boiling in bubbly flow regime

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Sang Jun; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    This paper presents a prediction of critical heat flux (CHF) in bubbly flow regime using dry-spot model proposed recently by authors for pool and flow boiling CHF and existing correlations for forced convective heat transfer coefficient, active site density and bubble departure diameter in nucleate boiling region. Without any empirical constants always present in earlier models, comparisons of the model predictions with experimental data for upward flow of water in vertical, uniformly-heated round tubes are performed and show a good agreement. The parametric trends of CHF have been explored with respect to variations in pressure, tube diameter and length, mass flux and inlet subcooling. 16 refs., 6 figs., 1 tab. (Author)

  20. A dry-spot model for the prediction of critical heat flux in water boiling in bubbly flow regime

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Sang Jun; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-12-31

    This paper presents a prediction of critical heat flux (CHF) in bubbly flow regime using dry-spot model proposed recently by authors for pool and flow boiling CHF and existing correlations for forced convective heat transfer coefficient, active site density and bubble departure diameter in nucleate boiling region. Without any empirical constants always present in earlier models, comparisons of the model predictions with experimental data for upward flow of water in vertical, uniformly-heated round tubes are performed and show a good agreement. The parametric trends of CHF have been explored with respect to variations in pressure, tube diameter and length, mass flux and inlet subcooling. 16 refs., 6 figs., 1 tab. (Author)

  1. Distributional changes in the western Burrowing Owl (Athene cunicularia hypugaea) in North America from 1967 to 2008

    Science.gov (United States)

    Macias-Duarte, Alberto; Conway, Courtney J.

    2015-01-01

    The quantification of shifts in bird distributions in response to climate change provides an opportunity to gain a deeper understanding of the processes that influence species persistence. We used data from the North American Breeding Bird Survey (BBS) to document changes in the distributional limits of the western Burrowing Owl (Athene cunicularia hypugaea) from 1967 to 2008. We used logistic regression to model presence probability (p) as a function of longitude, latitude, and year. We modeled a linear trend in logit(p) through time with slope and intercept modeled as a double Fourier series of longitude and latitude. We found that the western Burrowing Owl has experienced an intriguing southward shift in the northern half of its breeding range, contrary to what is predicted by most species niche models and what has been observed for many other species in North America. The breeding range of the Burrowing Owl has been shrinking near its northern, western, and eastern edges. Our model detected the population declines that were observed in California and eastern Washington, in locations where maps based on route-specific estimating equations had predicted significant population increases. We suggest that the northern boundary of the breeding distribution of the western Burrowing Owl has contracted southward and the southern boundary of the species' breeding distribution has expanded southward into areas of northern Mexico that were formerly used only by wintering migrants.

  2. Validation of the openEHR archetype library by using OWL reasoning.

    Science.gov (United States)

    Menárguez-Tortosa, Marcos; Fernández-Breis, Jesualdo Tomás

    2011-01-01

    Electronic Health Record architectures based on the dual model architecture use archetypes for representing clinical knowledge. Therefore, ensuring their correctness and consistency is a fundamental research goal. In this work, we explore how an approach based on OWL technologies can be used for such purpose. This method has been applied to the openEHR archetype repository, which is the largest available one nowadays. The results of this validation are also reported in this study.

  3. XQOWL: An Extension of XQuery for OWL Querying and Reasoning

    Directory of Open Access Journals (Sweden)

    Jesús M. Almendros-Jiménez

    2015-01-01

    Full Text Available One of the main aims of the so-called Web of Data is to be able to handle heterogeneous resources where data can be expressed in either XML or RDF. The design of programming languages able to handle both XML and RDF data is a key target in this context. In this paper we present a framework called XQOWL that makes possible to handle XML and RDF/OWL data with XQuery. XQOWL can be considered as an extension of the XQuery language that connects XQuery with SPARQL and OWL reasoners. XQOWL embeds SPARQL queries (via Jena SPARQL engine in XQuery and enables to make calls to OWL reasoners (HermiT, Pellet and FaCT++ from XQuery. It permits to combine queries against XML and RDF/OWL resources as well as to reason with RDF/OWL data. Therefore input data can be either XML or RDF/OWL and output data can be formatted in XML (also using RDF/OWL XML serialization.

  4. Three-dimensional modeling of one-eighth of confined five- and nine-spot patterns

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Kassem, J.H.; Ertekin, T. (Pennsylvania State Univ., University Park, PA (USA)); Lutchmansingh, P.M. (Marietta Coll., OH (USA))

    1991-02-01

    The design and construction of the smallest element of symmetry of a confined flood pattern, in reservoir simulation, requires the use of modifiers for the flow terms in the equations of all boundary blocks in that element. These modifiers are necessary to describe the appropriate block volume, production rate, well productivity index, transmissibility in the x-, y-, and z-directions, and others depending on the recovery process. While modifiers for block volume and production rate are straightforward, those for other terms of importance in the flow equation are not. Even though a limited number of researchers and users may be aware of these modifiers, evidence abounds that the majority of researchers and practicing engineers are not aware of such. This fact is not surprising since information about these modifiers has not been published in the literature. A comprehensive catalogue is presented of all modifiers necessary to simulate 1/8 of confined five- and nine-spot patterns. These modifiers are provided for all possible block configurations including triangular half-, quarter-, and one-eighth blocks and rectangular half- and quarter-blocks. The derivation of these modifiers has sound theoretical basis and is general in that it can be applied to other food patterns or to the formulation of other recovery processes. Also the validity is investigated of a commonly used 1/8 of a confined five-spot pattern where the apex cells at the three corners are combined with the blocks adjoining them. It is found that while the simulation of 1/8 of a confined pattern produces exactly the same performance as that based on the whole pattern, the commonly used 1/8 of a confined pattern does not. Furthermore, the simulation of the smallest element of symmetry is an order of magnitude more cost-effective than the simulation of 1/4 or 1/2 confined pattern. 11 figs., 19 refs., 3 tabs.

  5. Semantic Web Services with Web Ontology Language (OWL-S) - Specification of Agent-Services for DARPA Agent Markup Language (DAML)

    National Research Council Canada - National Science Library

    Sycara, Katia P

    2006-01-01

    CMU did research and development on semantic web services using OWL-S, the semantic web service language under the Defense Advanced Research Projects Agency- DARPA Agent Markup Language (DARPA-DAML) program...

  6. Mapping between the OBO and OWL ontology languages.

    Science.gov (United States)

    Tirmizi, Syed Hamid; Aitken, Stuart; Moreira, Dilvan A; Mungall, Chris; Sequeda, Juan; Shah, Nigam H; Miranker, Daniel P

    2011-03-07

    Ontologies are commonly used in biomedicine to organize concepts to describe domains such as anatomies, environments, experiment, taxonomies etc. NCBO BioPortal currently hosts about 180 different biomedical ontologies. These ontologies have been mainly expressed in either the Open Biomedical Ontology (OBO) format or the Web Ontology Language (OWL). OBO emerged from the Gene Ontology, and supports most of the biomedical ontology content. In comparison, OWL is a Semantic Web language, and is supported by the World Wide Web consortium together with integral query languages, rule languages and distributed infrastructure for information interchange. These features are highly desirable for the OBO content as well. A convenient method for leveraging these features for OBO ontologies is by transforming OBO ontologies to OWL. We have developed a methodology for translating OBO ontologies to OWL using the organization of the Semantic Web itself to guide the work. The approach reveals that the constructs of OBO can be grouped together to form a similar layer cake. Thus we were able to decompose the problem into two parts. Most OBO constructs have easy and obvious equivalence to a construct in OWL. A small subset of OBO constructs requires deeper consideration. We have defined transformations for all constructs in an effort to foster a standard common mapping between OBO and OWL. Our mapping produces OWL-DL, a Description Logics based subset of OWL with desirable computational properties for efficiency and correctness. Our Java implementation of the mapping is part of the official Gene Ontology project source. Our transformation system provides a lossless roundtrip mapping for OBO ontologies, i.e. an OBO ontology may be translated to OWL and back without loss of knowledge. In addition, it provides a roadmap for bridging the gap between the two ontology languages in order to enable the use of ontology content in a language independent manner.

  7. Semantic Web Services with Web Ontology Language (OWL-S) - Specification of Agent-Services for DARPA Agent Markup Language (DAML)

    Science.gov (United States)

    2006-08-01

    Sycara, and T. Nishimura, "Towards a Semantic Web Ecommerce ," in Proceedings of 6th Conference on Business Information Systems (BIS2003), Colorado...the ontology used is the fictitious ontology http://fly.com/Onto. The advantage of using concepts from Web-addressable ontologies, rather than XML...the advantage of the OWL-S approach compared with other approaches, namely BPEL4WS and WS-CDL, is that OWL-S allows the flexibility to change the

  8. Bionic Design of Wind Turbine Blade Based on Long-Eared Owl's Airfoil.

    Science.gov (United States)

    Tian, Weijun; Yang, Zhen; Zhang, Qi; Wang, Jiyue; Li, Ming; Ma, Yi; Cong, Qian

    2017-01-01

    The main purpose of this paper is to demonstrate a bionic design for the airfoil of wind turbines inspired by the morphology of Long-eared Owl's wings. Glauert Model was adopted to design the standard blade and the bionic blade, respectively. Numerical analysis method was utilized to study the aerodynamic characteristics of the airfoils as well as the blades. Results show that the bionic airfoil inspired by the airfoil at the 50% aspect ratio of the Long-eared Owl's wing gives rise to a superior lift coefficient and stalling performance and thus can be beneficial to improving the performance of the wind turbine blade. Also, the efficiency of the bionic blade in wind turbine blades tests increases by 12% or above (up to 44%) compared to that of the standard blade. The reason lies in the bigger pressure difference between the upper and lower surface which can provide stronger lift.

  9. The stability and slow dynamics of spot patterns in the 2D Brusselator model: The effect of open systems and heterogeneities

    Science.gov (United States)

    Tzou, J. C.; Ward, M. J.

    2018-06-01

    Spot patterns, whereby the activator field becomes spatially localized near certain dynamically-evolving discrete spatial locations in a bounded multi-dimensional domain, is a common occurrence for two-component reaction-diffusion (RD) systems in the singular limit of a large diffusivity ratio. In previous studies of 2-D localized spot patterns for various specific well-known RD systems, the domain boundary was assumed to be impermeable to both the activator and inhibitor, and the reaction-kinetics were assumed to be spatially uniform. As an extension of this previous theory, we use formal asymptotic methods to study the existence, stability, and slow dynamics of localized spot patterns for the singularly perturbed 2-D Brusselator RD model when the domain boundary is only partially impermeable, as modeled by an inhomogeneous Robin boundary condition, or when there is an influx of inhibitor across the domain boundary. In our analysis, we will also allow for the effect of a spatially variable bulk feed term in the reaction kinetics. By applying our extended theory to the special case of one-spot patterns and ring patterns of spots inside the unit disk, we provide a detailed analysis of the effect on spot patterns of these three different sources of heterogeneity. In particular, when there is an influx of inhibitor across the boundary of the unit disk, a ring pattern of spots can become pinned to a ring-radius closer to the domain boundary. Under a Robin condition, a quasi-equilibrium ring pattern of spots is shown to exhibit a novel saddle-node bifurcation behavior in terms of either the inhibitor diffusivity, the Robin constant, or the ambient background concentration. A spatially variable bulk feed term, with a concentrated source of "fuel" inside the domain, is shown to yield a saddle-node bifurcation structure of spot equilibria, which leads to qualitatively new spot-pinning behavior. Results from our asymptotic theory are validated from full numerical

  10. Relative effects of road risk, habitat suitability, and connectivity on wildlife roadkills: the case of tawny owls (Strix aluco).

    Science.gov (United States)

    Santos, Sara M; Lourenço, Rui; Mira, António; Beja, Pedro

    2013-01-01

    Despite its importance for reducing wildlife-vehicle collisions, there is still incomplete understanding of factors responsible for high road mortality. In particular, few empirical studies examined the idea that spatial variation in roadkills is influenced by a complex interplay between road-related factors, and species-specific habitat quality and landscape connectivity. In this study we addressed this issue, using a 7-year dataset of tawny owl (Strix aluco) roadkills recorded along 37 km of road in southern Portugal. We used a multi-species roadkill index as a surrogate of intrinsic road risk, and we used a Maxent distribution model to estimate habitat suitability. Landscape connectivity was estimated from least-cost paths between tawny owl territories, using habitat suitability as a resistance surface. We defined 10 alternative scenarios to compute connectivity, based on variation in potential movement patterns according to territory quality and dispersal distance thresholds. Hierarchical partitioning of a regression model indicated that independent variation in tawny owl roadkills was explained primarily by the roadkill index (70.5%) and, to a much lesser extent, by landscape connectivity (26.2%), while habitat suitability had minor effects (3.3%). Analysis of connectivity scenarios suggested that owl roadkills were primarily related to short range movements (habitat quality and landscape connectivity are globally high for the study species. Nevertheless, the study supported the view that functional connectivity should be incorporated whenever possible in roadkill models, as it may greatly increase their power to predict the location of roadkill hotspots.

  11. CLUSTER MODEL FOR EXTENSIVE GIANT TIGER SHRIMP (Penaeus monodon Fab. TO PREVENT TRANSMISSION OF WHITE SPOT SYNDROME VIRUS

    Directory of Open Access Journals (Sweden)

    Arief Taslihan

    2015-06-01

    Full Text Available White spot syndrome virus (WSSV has become epidemic in Indonesia and affecting shrimp aquaculture interm of its production. White spot syndrome virus is transmitted from one to other ponds, through crustacean, included planktonic copepode as carrier for WSSV and through water from affected shrimp pond. A cluster model, consist of shrimp grow out ponds surrounded by non-shrimp pond as a role of biosecurity has been developed. The model aimed to prevent white spot virus transmission in extensive giant tiger shrimp pond. The study was conducted in two sites at Demak District, Central Java Province. As the treatment, a cluster consist of three shrimp ponds in site I, and two shrimp ponds in site II, each was surrounded by buffer ponds rearing only finfish. As the control, five extensive shrimp grow out ponds in site I and three shrimp grow out ponds in site II, with shrimp pond has neither applied biosecurity nor surrounded by non-shrimp pond as biosecurity as well considered as control ponds. The results found that treatment of cluster shrimp ponds surrounded by non-shrimp ponds could hold shrimp at duration of culture in the grow out pond (DOC 105.6±4.5 days significantly much longer than that of control that harvested at 60.9±16.0 days due to WSSV outbreak. Survival rate in trial ponds was 77.6±3.6%, significantly higher than that of control at 22.6±15.8%. Shrimp production in treatment ponds has total production of 425.1±146.6 kg/ha significantly higher than that of control that could only produced 54.5±47.6 kg/ha. Implementation of Better Management Practices (BMP by arranging shrimp ponds in cluster and surrounding by non-shrimp ponds proven effectively prevent WSSV transmission from traditional shrimp ponds in surrounding area.

  12. OWL2 benchmarking for the evaluation of knowledge based systems.

    Directory of Open Access Journals (Sweden)

    Sher Afgun Khan

    Full Text Available OWL2 semantics are becoming increasingly popular for the real domain applications like Gene engineering and health MIS. The present work identifies the research gap that negligible attention has been paid to the performance evaluation of Knowledge Base Systems (KBS using OWL2 semantics. To fulfil this identified research gap, an OWL2 benchmark for the evaluation of KBS is proposed. The proposed benchmark addresses the foundational blocks of an ontology benchmark i.e. data schema, workload and performance metrics. The proposed benchmark is tested on memory based, file based, relational database and graph based KBS for performance and scalability measures. The results show that the proposed benchmark is able to evaluate the behaviour of different state of the art KBS on OWL2 semantics. On the basis of the results, the end users (i.e. domain expert would be able to select a suitable KBS appropriate for his domain.

  13. Several required OWL features for indigenous knowledge management systems

    CSIR Research Space (South Africa)

    Alberts, R

    2012-05-01

    Full Text Available This paper describes the features required of OWL (Web Ontology Language) to realise and enhance Indigenous Knowledge (IK) digital repositories. Several needs for Indigenous Knowledge management systems (IKMSs) are articulated, based on extensive...

  14. Muscular Arrangement and Muscle Attachment Sites in the Cervical Region of the American Barn Owl (Tyto furcata pratincola.

    Directory of Open Access Journals (Sweden)

    Mark L L M Boumans

    Full Text Available Owls have the largest head rotation capability amongst vertebrates. Anatomical knowledge of the cervical region is needed to understand the mechanics of these extreme head movements. While data on the morphology of the cervical vertebrae of the barn owl have been provided, this study is aimed to provide an extensive description of the muscle arrangement and the attachment sites of the muscles on the owl's head-neck region. The major cervical muscles were identified by gross dissection of cadavers of the American barn owl (Tyto furcata pratincola, and their origin, courses, and insertion were traced. In the head-neck region nine superficial larger cervical muscles of the craniocervical, dorsal and ventral subsystems were selected for analysis, and the muscle attachment sites were illustrated in digital models of the skull and cervical vertebrae of the same species as well as visualised in a two-dimensional sketch. In addition, fibre orientation and lengths of the muscles and the nature (fleshy or tendinous of the attachment sites were determined. Myological data from this study were combined with osteological data of the same species. This improved the anatomical description of the cervical region of this species. The myological description provided in this study is to our best knowledge the most detailed documentation of the cervical muscles in a strigiform species presented so far. Our results show useful information for researchers in the field of functional anatomy, biomechanical modelling and for evolutionary and comparative studies.

  15. A 3D model of the membrane protein complex formed by the white spot syndrome virus structural proteins.

    Directory of Open Access Journals (Sweden)

    Yun-Shiang Chang

    Full Text Available BACKGROUND: Outbreaks of white spot disease have had a large negative economic impact on cultured shrimp worldwide. However, the pathogenesis of the causative virus, WSSV (whit spot syndrome virus, is not yet well understood. WSSV is a large enveloped virus. The WSSV virion has three structural layers surrounding its core DNA: an outer envelope, a tegument and a nucleocapsid. In this study, we investigated the protein-protein interactions of the major WSSV structural proteins, including several envelope and tegument proteins that are known to be involved in the infection process. PRINCIPAL FINDINGS: In the present report, we used coimmunoprecipitation and yeast two-hybrid assays to elucidate and/or confirm all the interactions that occur among the WSSV structural (envelope and tegument proteins VP51A, VP19, VP24, VP26 and VP28. We found that VP51A interacted directly not only with VP26 but also with VP19 and VP24. VP51A, VP19 and VP24 were also shown to have an affinity for self-interaction. Chemical cross-linking assays showed that these three self-interacting proteins could occur as dimers. CONCLUSIONS: From our present results in conjunction with other previously established interactions we construct a 3D model in which VP24 acts as a core protein that directly associates with VP26, VP28, VP38A, VP51A and WSV010 to form a membrane-associated protein complex. VP19 and VP37 are attached to this complex via association with VP51A and VP28, respectively. Through the VP26-VP51C interaction this envelope complex is anchored to the nucleocapsid, which is made of layers of rings formed by VP664. A 3D model of the nucleocapsid and the surrounding outer membrane is presented.

  16. The role of envelope shape in the localization of multiple sound sources and echoes in the barn owl.

    Science.gov (United States)

    Baxter, Caitlin S; Nelson, Brian S; Takahashi, Terry T

    2013-02-01

    Echoes and sounds of independent origin often obscure sounds of interest, but echoes can go undetected under natural listening conditions, a perception called the precedence effect. How does the auditory system distinguish between echoes and independent sources? To investigate, we presented two broadband noises to barn owls (Tyto alba) while varying the similarity of the sounds' envelopes. The carriers of the noises were identical except for a 2- or 3-ms delay. Their onsets and offsets were also synchronized. In owls, sound localization is guided by neural activity on a topographic map of auditory space. When there are two sources concomitantly emitting sounds with overlapping amplitude spectra, space map neurons discharge when the stimulus in their receptive field is louder than the one outside it and when the averaged amplitudes of both sounds are rising. A model incorporating these features calculated the strengths of the two sources' representations on the map (B. S. Nelson and T. T. Takahashi; Neuron 67: 643-655, 2010). The target localized by the owls could be predicted from the model's output. The model also explained why the echo is not localized at short delays: when envelopes are similar, peaks in the leading sound mask corresponding peaks in the echo, weakening the echo's space map representation. When the envelopes are dissimilar, there are few or no corresponding peaks, and the owl localizes whichever source is predicted by the model to be less masked. Thus the precedence effect in the owl is a by-product of a mechanism for representing multiple sound sources on its map.

  17. Mapping forest functional type in a forest-shrubland ecotone using SPOT imagery and predictive habitat distribution modelling

    Science.gov (United States)

    Assal, Timothy J.; Anderson, Patrick J.; Sibold, Jason

    2015-01-01

    The availability of land cover data at local scales is an important component in forest management and monitoring efforts. Regional land cover data seldom provide detailed information needed to support local management needs. Here we present a transferable framework to model forest cover by major plant functional type using aerial photos, multi-date Système Pour l’Observation de la Terre (SPOT) imagery, and topographic variables. We developed probability of occurrence models for deciduous broad-leaved forest and needle-leaved evergreen forest using logistic regression in the southern portion of the Wyoming Basin Ecoregion. The model outputs were combined into a synthesis map depicting deciduous and coniferous forest cover type. We evaluated the models and synthesis map using a field-validated, independent data source. Results showed strong relationships between forest cover and model variables, and the synthesis map was accurate with an overall correct classification rate of 0.87 and Cohen’s kappa value of 0.81. The results suggest our method adequately captures the functional type, size, and distribution pattern of forest cover in a spatially heterogeneous landscape.

  18. Surveillance test of OWL-2 inpile tube

    International Nuclear Information System (INIS)

    Shimizu, Masatsugu; Itoh, Noboru

    1976-08-01

    A series of irradiation surveillance tests performed in integrity evaluation of an inpile tube for the test loop OWL-2 are described. Specimens were exposed to the neutron fluences from 1 x 10 20 to 3.4 x 10 21 n/cm 2 (>1 MeV), and subjected to post-irradiation tensile test at room temperature and service temperature 285 0 C. The strength increased and the ductility decreased with increasing neutron fluence. The reduction in fracture ductility due to neutron irradiation in the fluence range was insignificant, and the elongation of 33% was retained even for the maximum neutron fluence at 285 0 C. Little decrease of the ductility with fluence indicates that the tube would be in service for long time, ie to the integral fluence of 3.4 x 10 21 n/cm 2 . (auth.)

  19. Owl-inspired leading-edge serrations play a crucial role in aerodynamic force production and sound suppression.

    Science.gov (United States)

    Rao, Chen; Ikeda, Teruaki; Nakata, Toshiyuki; Liu, Hao

    2017-07-04

    Owls are widely known for silent flight, achieving remarkably low noise gliding and flapping flights owing to their unique wing morphologies, which are normally characterized by leading-edge serrations, trailing-edge fringes and velvet-like surfaces. How these morphological features affect aerodynamic force production and sound suppression or noise reduction, however, is still not well known. Here we address an integrated study of owl-inspired single feather wing models with and without leading-edge serrations by combining large-eddy simulations (LES) with particle-image velocimetry (PIV) and force measurements in a low-speed wind tunnel. With velocity and pressure spectra analysis, we demonstrate that leading-edge serrations can passively control the laminar-turbulent transition over the upper wing surface, i.e. the suction surface at all angles of attack (0°    15° where owl wings often reach in flight. Our results indicate that the owl-inspired leading-edge serrations may be a useful device for aero-acoustic control in biomimetic rotor designs for wind turbines, aircrafts, multi-rotor drones as well as other fluid machinery.

  20. OWL representation of the geologic timescale implementing stratigraphic best practice

    Science.gov (United States)

    Cox, S. J.

    2011-12-01

    The geologic timescale is a cornerstone of the earth sciences. Versions are available from many sources, with the following being of particular interest: (i) The official International Stratigraphic Chart (ISC) is maintained by the International Commission for Stratigraphy (ICS), following principles developed over the last 40 years. ICS provides the data underlying the chart as part of a specialized software package, and the chart itself as a PDF using the standard colours; (ii) ITC Enschede has developed a representation of the timescale as a thesaurus in SKOS, used in a Web Map Service delivery system; (iii) JPL's SWEET ontology includes a geologic timescale. This takes full advantage of the capabilities of OWL. However, each of these has limitations - The ISC falls down because of incompatibility with web technologies; - While SKOS supports multilingual labelling, SKOS does not adequately support timescale semantics, in particular since it does not include ordering relationships; - The SWEET version (as of version 2) is not fully aligned to the model used by ICS, in particular not recognizing the role of the Global Boundary Stratotype Sections and Point (GSSP). Furthermore, it is distributed as static documents, rather than through a dynamic API using SPARQL. The representation presented in this paper overcomes all of these limitations as follows: - the timescale model is formulated as an OWL ontology - the ontology is directly derived from the UML representation of the ICS best practice proposed by Cox & Richard [2005], and subsequently included as the Geologic Timescale package in GeoSciML (http://www.geosciml.org); this includes links to GSSPs as per the ICS process - key properties in the ontology are also asserted to be subProperties of SKOS properties (topConcept and broader/narrower relations) in order to support SKOS-based queries; SKOS labelling is used to support multi-lingual naming and synonyms - the International Stratigraphic Chart is implemented

  1. Option Price Decomposition in Spot-Dependent Volatility Models and Some Applications

    Directory of Open Access Journals (Sweden)

    Raúl Merino

    2017-01-01

    Full Text Available We obtain a Hull and White type option price decomposition for a general local volatility model. We apply the obtained formula to CEV model. As an application we give an approximated closed formula for the call option price under a CEV model and an approximated short term implied volatility surface. These approximated formulas are used to estimate model parameters. Numerical comparison is performed for our new method with exact and approximated formulas existing in the literature.

  2. Rocky Mountain spotted fever

    Science.gov (United States)

    ... spotted fever on the foot Rocky Mountain spotted fever, petechial rash Antibodies Deer and dog tick References McElligott SC, Kihiczak GG, Schwartz RA. Rocky Mountain spotted fever and other rickettsial infections. In: Lebwohl MG, Heymann ...

  3. Ecotoxicological suitability of floodplain habitats in The Netherlands for the little owl (Athene noctua vidalli)

    International Nuclear Information System (INIS)

    Brink, N.W. van den; Groen, N.M.; Jonge, J. de; Bosveld, A.T.C.

    2003-01-01

    PCBs pose a risk to little owls from floodplain habitats. - This study describes the actual risks of exposure to contaminants, which little owls (Athene noctua vidalli) face in Dutch river floodplains. The results indicate that PCBs pose a risk: not only are levels in little owls from floodplains higher than levels found in little owls from a reference site but the PCB patterns in owls from the floodplains also indicate induction of hepatic cytochrome P450 enzymes by dioxin like compounds, possibly PCBs. Of the heavy metals, only cadmium is thought to pose a risk in certain conditions, for example, when little owls are feeding only on earthworms over a prolonged period of time. The results do not indicate any effects on the occurrence of prey items of the little owl like for instance earthworm, beetles and shrews. Hence, it is not expected that little owls will be affected by diminishing prey availability due to contamination

  4. Ecotoxicological suitability of floodplain habitats in The Netherlands for the little owl (Athene noctua vidalli)

    Energy Technology Data Exchange (ETDEWEB)

    Brink, N.W. van den; Groen, N.M.; Jonge, J. de; Bosveld, A.T.C

    2003-03-01

    PCBs pose a risk to little owls from floodplain habitats. - This study describes the actual risks of exposure to contaminants, which little owls (Athene noctua vidalli) face in Dutch river floodplains. The results indicate that PCBs pose a risk: not only are levels in little owls from floodplains higher than levels found in little owls from a reference site but the PCB patterns in owls from the floodplains also indicate induction of hepatic cytochrome P450 enzymes by dioxin like compounds, possibly PCBs. Of the heavy metals, only cadmium is thought to pose a risk in certain conditions, for example, when little owls are feeding only on earthworms over a prolonged period of time. The results do not indicate any effects on the occurrence of prey items of the little owl like for instance earthworm, beetles and shrews. Hence, it is not expected that little owls will be affected by diminishing prey availability due to contamination.

  5. Parental investment and its sensitivity to corticosterone is linked to melanin-based coloration in barn owls.

    Science.gov (United States)

    Almasi, Bettina; Roulin, Alexandre; Jenni-Eiermann, Susanne; Jenni, Lukas

    2008-06-01

    Behavioral and physiological responses to unpredictable changes in environmental conditions are, in part, mediated by glucocorticoids (corticosterone in birds). In polymorphic species, individuals of the same sex and age display different heritable melanin-based color morphs, associated with physiological and reproductive parameters and possibly alternative strategies to cope with variation in environmental conditions. We examined whether the role of corticosterone in resolving the trade-off between self-maintenance and reproductive activities covaries with the size of melanin-based spots displayed on the ventral body side of male barn owls. Administration of corticosterone to simulate physiological stress in males revealed pronounced changes in their food-provisioning rates to nestlings compared to control males. Corticosterone-treated males with small eumelanic spots reduced nestling provisioning rates as compared to controls, and also to a greater degree than did corticosterone-treated males with large spots. Large-spotted males generally exhibited lower parental provisioning and appear insensitive to exogenous corticosterone suggesting that the size of the black spots on the breast feathers predicts the ability to cope with stressful situations. The reduced provisioning rate of corticosterone-treated males caused a temporary reduction in nestling growth rates but, did not affect fledgling success. This suggests that moderately elevated corticosterone levels are not inhibitory to current reproduction but rather trigger behavioral responses to maximize lifetime reproductive success.

  6. Comparative value of blood and skin samples for diagnosis of spotted fever group rickettsial infection in model animals.

    Science.gov (United States)

    Levin, Michael L; Snellgrove, Alyssa N; Zemtsova, Galina E

    2016-07-01

    The definitive diagnosis of spotted fever group (SFG) rickettsioses in humans is challenging due to the retrospective nature and cross reactivity of the serological methods and the absence of reliable and consistent samples for molecular diagnostics. Existing data indicate the transient character of bacteremia in experimentally infected animals. The ability of arthropod vectors to acquire rickettsial infection from the laboratory animals in the absence of systemic infection and known tropism of rickettsial agents to endothelial cells of peripheral blood vessels underline the importance of local infection and consequently the diagnostic potential of skin samples. In order to evaluate the diagnostic sensitivity of rickettsial DNA detection in blood and skin samples, we compared results of PCR testing in parallel samples collected from model laboratory animals infected with Rickettsia rickettsii, Rickettsia parkeri and Rickettsia slovaca-like agent at different time points after infection. Skin samples were collected from ears - away from the site of tick placement and without eschars. Overall, testing of skin samples resulted in a higher proportion of positive results than testing of blood samples. Presented data from model animals demonstrates that testing of skin samples from sites of rickettsial proliferation can provide definitive molecular diagnosis of up to 60-70% of tick-borne SFG rickettsial infections during the acute stage of illness. Detection of pathogen DNA in cutaneous samples is a valuable alternative to blood-PCR at least in model animals. Published by Elsevier GmbH.

  7. Are owl pellets good estimators of prey abundance?

    Directory of Open Access Journals (Sweden)

    Analia Andrade

    2016-07-01

    Full Text Available Some ecologists have been skeptics about the use of owl pellets to estimate small mammal’s fauna. This is due to the assumptions required by this method: (a that owls hunt at random, and (b that pellets represent a random sample from the environment. We performed statistical analysis to test these assumptions and to assess the effectiveness of Barn owl pellets as a useful estimator of field abundances of its preys. We used samples collected in the arid Extra-Andean Patagonia along an altitudinal environmental gradient from lower Monte ecoregion to upper Patagonian steppe ecoregion, with a mid-elevation ecotone. To test if owls hunt at random, we estimated expected pellet frequency by creating a distribution of random pellets, which we compared with data using a simulated chi-square. To test if pellets represent a random sample from the environment, differences between ecoregions were evaluated by PERMANOVAs with Bray–Curtis dissimilarities. We did not find evidence that owls foraged non-randomly. Therefore, we can assume that the proportions of the small mammal’s species in the diet are representative of the proportions of the species in their communities. Only Monte is different from other ecoregions. The ecotone samples are grouped with those of Patagonian steppes. There are no real differences between localities in the small mammal’s abundances in each of these ecoregions and/or Barn owl pellets cannot detect patterns at a smaller spatial scale. Therefore, we have no evidence to invalidate the use of owl pellets at an ecoregional scale.

  8. "An Asymptotic Expansion Approach to Currency Options with a Market Model of Interest Rates under Stochastic Volatility Processes of Spot Exchange Rates"

    OpenAIRE

    Akihiko Takahashi; Kohta Takehara

    2007-01-01

    This paper proposes an asymptotic expansion scheme of currency options with a libor market model of interest rates and stochastic volatility models of spot exchange rates. In particular, we derive closed-form approximation formulas for the density functions of the underlying assets and for pricing currency options based on the third order asymptotic expansion scheme; we do not model a foreign exchange rate's variance such as in Heston[1993], but its volatility that follows a general time-inho...

  9. A combined modeling approach for wind power feed-in and electricity spot prices

    International Nuclear Information System (INIS)

    Keles, Dogan; Genoese, Massimo; Möst, Dominik; Ortlieb, Sebastian; Fichtner, Wolf

    2013-01-01

    Wind power generation and its impacts on electricity prices has strongly increased in the EU. Therefore, appropriate mark-to-market evaluation of new investments in wind power and energy storage plants should consider the fluctuant generation of wind power and uncertain electricity prices, which are affected by wind power feed-in (WPF). To gain the input data for WPF and electricity prices, simulation models, such as econometric models, can serve as a data basis. This paper describes a combined modeling approach for the simulation of WPF series and electricity prices considering the impacts of WPF on prices based on an autoregressive approach. Thereby WPF series are firstly simulated for each hour of the year and integrated in the electricity price model to generate an hourly resolved price series for a year. The model results demonstrate that the WPF model delivers satisfying WPF series and that the extended electricity price model considering WPF leads to a significant improvement of the electricity price simulation compared to a model version without WPF effects. As the simulated series of WPF and electricity prices also contain the correlation between both series, market evaluation of wind power technologies can be accurately done based on these series. - Highlights: • Wind power feed-in can be directly simulated with stochastic processes. • Non-linear relationship between wind power feed-in and electricity prices. • Price reduction effect of wind power feed-in depends on the actual load. • Considering wind power feed-in effects improves the electricity price simulation. • Combined modeling of both parameters delivers a data basis for evaluation tools

  10. Impacts of subsidized renewable electricity generation on spot market prices in Germany: evidence from a Garch model with panel data

    International Nuclear Information System (INIS)

    Pham, Thao; Lemoine, Killian

    2015-01-01

    Electricity generated by renewable energy sources creates a downward pressure on wholesale prices through - the so-called 'merit order effect'. This effect tends to lower average power prices and average market revenue that renewables producers should have received, making integration costs of renewables very high at large penetration rate. It is therefore crucial to determine the amplitude of this merit order effect particularly in the context of increasing burden of renewable support policies borne by final consumers. Using hourly data for the period 2009-2012 in German electricity wholesale market for GARCH model under panel data framework, we find that wind and solar power generation injected into German electricity network during this period induces a decrease of electricity spot prices and a slight increase of their volatility. The model-based results suggest that the merit-order effect created by renewable production ranges from 3.86 to 8.34 euro/MWh which implies to the annual volume of consumers' surplus from 1.89 to 3.92 billion euros. However this surplus has not been re-distributed equally among different types of electricity consumers. (authors)

  11. Chapter 16. Conservation status of great gray owls in the United States

    Science.gov (United States)

    Gregory D. Hayward

    1994-01-01

    Previous chapters outlined the biology and ecology of great gray owls as well as the ecology of this species in the western United States. That technical review provides the basis to assess the current conservation status of great gray owls in the United States. Are populations of great gray owls in the United States currently threatened? Are current land management...

  12. Habitat selection by owls in a seasonal semi-deciduous forest in southern Brazil

    Directory of Open Access Journals (Sweden)

    W. Menq

    Full Text Available Abstract This paper tested the hypothesis that the structural components of vegetation have impact over the distribution of owl species in a fragment of a semi-deciduous seasonal forest. This paper also determined which vegetation variables contributed to the spatial distribution of owl species. It was developed in the Perobas Biological Reserve (PBR between September and December 2011. To conduct the owl census, a playback technique was applied at hearing points distributed to cover different vegetation types in the study area. A total of 56 individual owls of six species were recorded: Tropical Screech-Owl (Megascops choliba, Black-capped Screech-Owl (Megascops atricapilla, Tawny-browed Owl (Pulsatrix koeniswaldiana, Ferruginous Pygmy-Owl (Glaucidium brasilianum, Mottled Owl (Strix virgata and Stygian Owl (Asio stygius. The results suggest that the variables of vegetation structure have impact on the occurrence of owls. The canopy height, the presence of hollow trees, fallen trees and glades are the most important structural components influencing owl distribution in the sampled area.

  13. Book review: Peeters, H. 2007. Field guide to owls of California and the West

    Science.gov (United States)

    Eric D. Forsman

    2010-01-01

    Field Guide to Owls of California and the West. Written primarily for nonprofessionals,this little field guide is a treasure trove of published and unpublished information on the natural history and distribution of owls in the western United States. It covers just about everything you could want to know about owls, from why they take dust baths, to facultative...

  14. Biology and conservation of owls of the Northern Hemisphere: 2nd International symposium

    Science.gov (United States)

    James R. Duncan; David H. Johnson; Thomas H. Nicholls

    1997-01-01

    The proceeding contains 91 papers authored by 143 people from 13 countries covering biology, ecology, monitoring, habitat-use, status conservation, education, genetics, toxicology, diet, migration, mortality and related topics concerning owls of the Northern Hemisphere. Thirty-three owl species are discussed. Information presented will be useful in owl conservation,...

  15. Predictive Models for Tomato Spotted Wilt Virus Spread Dynamics, Considering Frankliniella occidentalis Specific Life Processes as Influenced by the Virus.

    Directory of Open Access Journals (Sweden)

    Pamella Akoth Ogada

    Full Text Available Several models have been studied on predictive epidemics of arthropod vectored plant viruses in an attempt to bring understanding to the complex but specific relationship between the three cornered pathosystem (virus, vector and host plant, as well as their interactions with the environment. A large body of studies mainly focuses on weather based models as management tool for monitoring pests and diseases, with very few incorporating the contribution of vector's life processes in the disease dynamics, which is an essential aspect when mitigating virus incidences in a crop stand. In this study, we hypothesized that the multiplication and spread of tomato spotted wilt virus (TSWV in a crop stand is strongly related to its influences on Frankliniella occidentalis preferential behavior and life expectancy. Model dynamics of important aspects in disease development within TSWV-F. occidentalis-host plant interactions were developed, focusing on F. occidentalis' life processes as influenced by TSWV. The results show that the influence of TSWV on F. occidentalis preferential behaviour leads to an estimated increase in relative acquisition rate of the virus, and up to 33% increase in transmission rate to healthy plants. Also, increased life expectancy; which relates to improved fitness, is dependent on the virus induced preferential behaviour, consequently promoting multiplication and spread of the virus in a crop stand. The development of vector-based models could further help in elucidating the role of tri-trophic interactions in agricultural disease systems. Use of the model to examine the components of the disease process could also boost our understanding on how specific epidemiological characteristics interact to cause diseases in crops. With this level of understanding we can efficiently develop more precise control strategies for the virus and the vector.

  16. Model of liquid-metal splashing in the cathode spot of a vacuum arc discharge

    International Nuclear Information System (INIS)

    Gashkov, M. A.; Zubarev, N. M.; Zubareva, O. V.; Mesyats, G. A.; Uimanov, I. V.

    2016-01-01

    The formation of microjets is studied during the extrusion of a melted metal by the plasma pressure from craters formed on a cathode in a burning vacuum arc. An analytic model of liquid-metal splashing that includes two stages is proposed. At the first stage, the liquid motion has the axial symmetry and a liquid-metal wall surrounding the crater is formed. At the second stage, the axial symmetry is broken due to the development of the Plateau–Rayleigh instability in the upper part of the wall. The wall breakup process is shown to have a threshold. The minimal plasma pressure and the minimal electric current flowing through the crater required for obtaining the liquid-metal splashing regime are found. The basic spatial and temporal characteristics of the jet formation process are found using the analytic model.

  17. Electricity demand and spot price forecasting using evolutionary computation combined with chaotic nonlinear dynamic model

    International Nuclear Information System (INIS)

    Unsihuay-Vila, C.; Zambroni de Souza, A.C.; Marangon-Lima, J.W.; Balestrassi, P.P.

    2010-01-01

    This paper proposes a new hybrid approach based on nonlinear chaotic dynamics and evolutionary strategy to forecast electricity loads and prices. The main idea is to develop a new training or identification stage in a nonlinear chaotic dynamic based predictor. In the training stage five optimal parameters for a chaotic based predictor are searched through an optimization model based on evolutionary strategy. The objective function of the optimization model is the mismatch minimization between the multi-step-ahead forecasting of predictor and observed data such as it is done in identification problems. The first contribution of this paper is that the proposed approach is capable of capturing the complex dynamic of demand and price time series considered resulting in a more accuracy forecasting. The second contribution is that the proposed approach run on-line manner, i.e. the optimal set of parameters and prediction is executed automatically which can be used to prediction in real-time, it is an advantage in comparison with other models, where the choice of their input parameters are carried out off-line, following qualitative/experience-based recipes. A case study of load and price forecasting is presented using data from New England, Alberta, and Spain. A comparison with other methods such as autoregressive integrated moving average (ARIMA) and artificial neural network (ANN) is shown. The results show that the proposed approach provides a more accurate and effective forecasting than ARIMA and ANN methods. (author)

  18. A comparison between Poisson and zero-inflated Poisson regression models with an application to number of black spots in Corriedale sheep

    Directory of Open Access Journals (Sweden)

    Rodrigues-Motta Mariana

    2008-07-01

    Full Text Available Abstract Dark spots in the fleece area are often associated with dark fibres in wool, which limits its competitiveness with other textile fibres. Field data from a sheep experiment in Uruguay revealed an excess number of zeros for dark spots. We compared the performance of four Poisson and zero-inflated Poisson (ZIP models under four simulation scenarios. All models performed reasonably well under the same scenario for which the data were simulated. The deviance information criterion favoured a Poisson model with residual, while the ZIP model with a residual gave estimates closer to their true values under all simulation scenarios. Both Poisson and ZIP models with an error term at the regression level performed better than their counterparts without such an error. Field data from Corriedale sheep were analysed with Poisson and ZIP models with residuals. Parameter estimates were similar for both models. Although the posterior distribution of the sire variance was skewed due to a small number of rams in the dataset, the median of this variance suggested a scope for genetic selection. The main environmental factor was the age of the sheep at shearing. In summary, age related processes seem to drive the number of dark spots in this breed of sheep.

  19. Mutual mortality of great horned owl and southern black racer: a potential risk of raptors preying on snakes

    Science.gov (United States)

    Roger W. Perry; Raymond E. Brown; D. Craig Rudolph

    2001-01-01

    We encountered a dead southern black racer snake (Coluber constrictor priapus) coiled around a dead Great Horned Owl (Bubo virginianus). We suggest the owl was strangled by the snake before the snake did of wounds inflicted by the owl. There are previous reports of intense physical struggle between Great Horned Owls (and...

  20. Habitat use and movements of breeding male Boreal Owls (Aegolius funereus) in northeast Minnesota as determined by radio telemetry

    Science.gov (United States)

    William H. Lane; David E. Andersen; Thomas H. Nicholls

    1997-01-01

    To determine habitat use and movements of male Boreal Owls (Aegolius funereus) in northeast Minnesota, we monitored 10 radio-equipped owls from 1990-1992. We used mist nets, bal-chartris, and the taped playback recording of the primary song of the male Boreal Owl to trap territorial male owls during the springtime breeding season.

  1. Estimating and mapping forest biomass using regression models and Spot-6 images (case study: Hyrcanian forests of north of Iran).

    Science.gov (United States)

    Motlagh, Mohadeseh Ghanbari; Kafaky, Sasan Babaie; Mataji, Asadollah; Akhavan, Reza

    2018-05-21

    Hyrcanian forests of North of Iran are of great importance in terms of various economic and environmental aspects. In this study, Spot-6 satellite images and regression models were applied to estimate above-ground biomass in these forests. This research was carried out in six compartments in three climatic (semi-arid to humid) types and two altitude classes. In the first step, ground sampling methods at the compartment level were used to estimate aboveground biomass (Mg/ha). Then, by reviewing the results of other studies, the most appropriate vegetation indices were selected. In this study, three indices of NDVI, RVI, and TVI were calculated. We investigated the relationship between the vegetation indices and aboveground biomass measured at sample-plot level. Based on the results, the relationship between aboveground biomass values and vegetation indices was a linear regression with the highest level of significance for NDVI in all compartments. Since at the compartment level the correlation coefficient between NDVI and aboveground biomass was the highest, NDVI was used for mapping aboveground biomass. According to the results of this study, biomass values were highly different in various climatic and altitudinal classes with the highest biomass value observed in humid climate and high-altitude class.

  2. Optimization and modeling of spot welding parameters with simultaneous multiple response consideration using multi objective Taguchi method and RSM

    Energy Technology Data Exchange (ETDEWEB)

    Muhammad, Nora Siah; Manurung Yupiter HP; Hafidzi, Moham Mad; Abas, Sun Haji Kiyai; Tham, Ghalib; Haru Man, Esa [Universiti Teknologi MARA (UiTM), Selangor (Malaysia)

    2012-08-15

    This paper presents an alternative method to optimize process parameters of resistance spot welding (RSW) towards weld zone development. The optimization approach attempts to consider simultaneously the multiple quality characteristics, namely weld nugget and heat affected zone (HAZ), using multi objective Taguchi method (MTM). The experimental study was conducted for plate thickness of 1.5mm under different welding current, weld time and hold time. The optimum welding parameters were investigated using the Taguchi method with L9 orthogonal array. The optimum value was analyzed by means of MTM, which involved the calculation of total normalized quality loss (TNQL) and multi signal to noise ratio (MSNR). A significant level of the welding parameters was further obtained by using analysis of variance (ANOVA). Furthermore, the first order model for predicting the weld zone development is derived by using response surface methodology (RSM). Based on the experimental confirmation test, the proposed method can be effectively applied to estimate the size of weld zone, which can be used to enhance and optimized the welding performance in RSW or other application.

  3. Optimization and modeling of spot welding parameters with simultaneous multiple response consideration using multi objective Taguchi method and RSM

    International Nuclear Information System (INIS)

    Muhammad, Nora Siah; Manurung Yupiter HP; Hafidzi, Moham Mad; Abas, Sun Haji Kiyai; Tham, Ghalib; Haru Man, Esa

    2012-01-01

    This paper presents an alternative method to optimize process parameters of resistance spot welding (RSW) towards weld zone development. The optimization approach attempts to consider simultaneously the multiple quality characteristics, namely weld nugget and heat affected zone (HAZ), using multi objective Taguchi method (MTM). The experimental study was conducted for plate thickness of 1.5mm under different welding current, weld time and hold time. The optimum welding parameters were investigated using the Taguchi method with L9 orthogonal array. The optimum value was analyzed by means of MTM, which involved the calculation of total normalized quality loss (TNQL) and multi signal to noise ratio (MSNR). A significant level of the welding parameters was further obtained by using analysis of variance (ANOVA). Furthermore, the first order model for predicting the weld zone development is derived by using response surface methodology (RSM). Based on the experimental confirmation test, the proposed method can be effectively applied to estimate the size of weld zone, which can be used to enhance and optimized the welding performance in RSW or other application

  4. Quench evolution and hot spot temperature in the ATLAS B0 model coil

    CERN Document Server

    Dudarev, A; Boxman, H; Broggi, F; Dolgetta, N; Juster, F P; Tetteroo, M; ten Kate, H H J

    2004-01-01

    The 9-m long superconducting model coil B0 was built to verify design parameters and exercise the construction of the Barrel Toroid magnet of ATLAS Detector. The model coil has been successfully tested at CERN. An intensive test program to study quench propagation through the coil windings as well as the temperature distribution has been carried out. The coil is well equipped with pickup coils, voltage taps, superconducting quench detectors and temperature sensors. The current is applied up to 24 kA and about forty quenches have been induced by firing internal heaters. Characteristic numbers at full current of 24 kA are a normal zone propagation of 15 m/s in the conductor leading to a turn-to-turn propagation of 0.1 m/s, the entire coil in normal state within 5.5 s and a safe peak temperature in the windings of 85 K. The paper summarizes the quench performance of the B0 coil. Based on this experience the full-size coils are now under construction and first test results are awaited by early 2004. 7 Refs.

  5. Hot-spots of primary productivity: An Alternative interpretation to Conventional upwelling models

    Science.gov (United States)

    van Ruth, Paul D.; Ganf, George G.; Ward, Tim M.

    2010-12-01

    The eastern Great Australian Bight (EGAB) forms part of the Southern and Indian Oceans and is an area of high ecological and economic importance. Although it supports a commercial fishery, quantitative estimates of the primary productivity underlying this industry are open to debate. Estimates range from 500 mg C m -2 day -1. Part of this variation may be due to the unique upwelling circulation of shelf waters in summer/autumn (November-April), which shares some similarities with highly productive eastern boundary current upwelling systems, but differs due to the influence of a northern boundary current, the Flinders current, and a wide continental shelf. This study examines spatial variations in primary productivity in the EGAB during the upwelling seasons of 2005 and 2006. Daily integral productivity calculated using the vertically generalised production model (VGPM) showed a high degree of spatial variation. Productivity was low (modelled with the VGPM, which uses surface measures of phytoplankton biomass to calculate productivity. Macro-nutrient concentrations could not be used to explain the difference in the low and high productivities (silica > 1 μmol L -1, nitrate/nitrite > 0.4 μmol L -1, phosphate > 0.1 μmol L -1). Mixing patterns or micro-nutrient concentrations are possible explanations for spatial variations in primary productivity in the EGAB. On a global scale, daily rates of primary productivity of the EGAB lie between the highly productive eastern boundary current upwelling systems, and less productive coastal regions of western and south eastern Australia, and the oligotrophic ocean. However, daily productivity rates in the upwelling hotspots of the EGAB rival productivities in Benguela and Humboldt currents.

  6. Nocturnal raptors (owls: contributions to study of its popularity

    Directory of Open Access Journals (Sweden)

    Maria Lindelia Rincón Hernández

    2017-01-01

    Full Text Available This research characterizes the nocturnal birds of prey on the campus of Universidad Pedagógica y Tecnológica de Colombia (UPTC; in English, Pedagogical and Technological University of Colombia, in addition to the contribution to the study of its popularity, with students in fifth grade from two educational institutions, one, of the urban context, and other, of the rural context. The study involved the implementation of the didactic component to promote recognition of their biological significance in elementary school students. Among the findings two species of nocturnal birds of prey were identified: common currucutú owl (Tropical Screech Owl, Megascops choliba and the barn owl (Tyto alba, with a relative abundance of 12 individuals and 10 individuals, respectively. It also includes changes in perception from students regarding beliefs and superstitions about such species, which favors the recognition of the biological role in the ecosystem and the need for its conservation.

  7. Laser beam induced nanoscale spot through nonlinear “thick” samples: A multi-layer thin lens self-focusing model

    International Nuclear Information System (INIS)

    Wei, Jingsong; Yan, Hui

    2014-01-01

    Self-focusing is a well-researched phenomenon. Nanoscale spots can be achieved through self-focusing, which is an alternative method for achieving high-density data storage, high-resolution light imaging, and maskless nanolithography. Several research groups have observed that self-focusing spots can be reduced to nanoscale levels via incident laser power manipulation. Self-focusing spots can be analyzed by solving the nonlinear Schrödinger equation and the finite difference time domain method. However, both procedures are complex and time-consuming. In the present work, a multi-layer thin-lens self-focusing model that considers diffraction effects and changes of refractive index along the radial and film thickness directions is proposed to analyze the self-focusing behavior and traveling process of light beams intuitively. The self-focusing behaviors of As 2 S 3 are simulated, and results show that a nanoscale self-focusing spot with a radius of about 0.12 μm can be formed at the bottom of nonlinear sample when the incident laser power exceeds 4.25 mW. Our findings are basically consistent with experimental reports and provide a good method for analyzing and understanding the self-focusing process. An appropriate application schematic design is also provided

  8. Morphological Variations of Leading-Edge Serrations in Owls (Strigiformes.

    Directory of Open Access Journals (Sweden)

    Matthias Weger

    Full Text Available Owls have developed serrations, comb-like structures, along the leading edge of their wings. Serrations were investigated from a morphological and a mechanical point of view, but were not yet quantitatively compared for different species. Such a comparative investigation of serrations from species of different sizes and activity patterns may provide new information about the function of the serrations.Serrations on complete wings and on tenth primary remiges of seven owl species were investigated. Small, middle-sized, and large owl species were investigated as well as species being more active during the day and owls being more active during the night. Serrations occurred at the outer parts of the wings, predominantly at tenth primary remiges, but also on further wing feathers in most species. Serration tips were oriented away from the feather rachis so that they faced into the air stream during flight. The serrations of nocturnal owl species were higher developed as demonstrated by a larger inclination angle (the angle between the base of the barb and the rachis, a larger tip displacement angle (the angle between the tip of the serration and the base of the serration and a longer length. Putting the measured data into a clustering algorithm yielded dendrograms that suggested a strong influence of activity pattern, but only a weak influence of size on the development of the serrations.Serrations are supposed to be involved in noise reduction during flight and also depend on the aerodynamic properties that in turn depend on body size. Since especially nocturnal owls have to rely on hearing during prey capture, the more pronounced serrations of nocturnal species lend further support to the notion that serrations have an important function in noise reduction. The differences in shape of the serrations investigated indicate that a silent flight requires well-developed serrations.

  9. Socialization of adult owl monkeys (Aotus sp.) in Captivity.

    Science.gov (United States)

    Williams, Lawrence E; Coke, C S; Weed, J L

    2017-01-01

    Social housing has often been recommended as one-way to address the psychological well-being of captive non-human primates. Published reports have examined methods to socialize compatible animals by forming pairs or groups. Successful socialization rates vary depending on the species, gender, and environment. This study presents a retrospective look at pairing attempts in two species of owl monkeys, Aotus nancymaae and A. azarae, which live in monogamous pairs in the wild. The results of 477 pairing attempt conducted with captive, laboratory housed owl monkeys and 61 hr of behavioral observations are reported here. The greatest success pairing these owl monkeys occurred with opposite sex pairs, with an 82% success rate. Opposite sex pairs were more successful when females were older than males. Female-female pairs were more successful than male-male (MM) pairs (62% vs 40%). Successful pairs stayed together between 3 and 7 years before the animals were separated due to social incompatibility. Vigilance, eating, and sleeping during introductions significantly predicted success, as did the performance of the same behavior in both animals. The results of this analysis show that it is possible to give captive owl monkeys a social alternative even if species appropriate social partners (i.e., opposite sex partners) are not available. The focus of this report is a description of one potential way to enhance the welfare of a specific new world primate, the owl monkey, under laboratory conditions. More important is how the species typical social structure of owl monkeys in nature affects the captive management of this genus. Am. J. Primatol. 79:e22521, 2017. © 2015 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. Morphological Variations of Leading-Edge Serrations in Owls (Strigiformes)

    Science.gov (United States)

    Weger, Matthias; Wagner, Hermann

    2016-01-01

    Background Owls have developed serrations, comb-like structures, along the leading edge of their wings. Serrations were investigated from a morphological and a mechanical point of view, but were not yet quantitatively compared for different species. Such a comparative investigation of serrations from species of different sizes and activity patterns may provide new information about the function of the serrations. Results Serrations on complete wings and on tenth primary remiges of seven owl species were investigated. Small, middle-sized, and large owl species were investigated as well as species being more active during the day and owls being more active during the night. Serrations occurred at the outer parts of the wings, predominantly at tenth primary remiges, but also on further wing feathers in most species. Serration tips were oriented away from the feather rachis so that they faced into the air stream during flight. The serrations of nocturnal owl species were higher developed as demonstrated by a larger inclination angle (the angle between the base of the barb and the rachis), a larger tip displacement angle (the angle between the tip of the serration and the base of the serration) and a longer length. Putting the measured data into a clustering algorithm yielded dendrograms that suggested a strong influence of activity pattern, but only a weak influence of size on the development of the serrations. Conclusions Serrations are supposed to be involved in noise reduction during flight and also depend on the aerodynamic properties that in turn depend on body size. Since especially nocturnal owls have to rely on hearing during prey capture, the more pronounced serrations of nocturnal species lend further support to the notion that serrations have an important function in noise reduction. The differences in shape of the serrations investigated indicate that a silent flight requires well-developed serrations. PMID:26934104

  11. Aber-OWL: a framework for ontology-based data access in biology

    KAUST Repository

    Hoehndorf, Robert

    2015-01-28

    Background: Many ontologies have been developed in biology and these ontologies increasingly contain large volumes of formalized knowledge commonly expressed in the Web Ontology Language (OWL). Computational access to the knowledge contained within these ontologies relies on the use of automated reasoning. Results: We have developed the Aber-OWL infrastructure that provides reasoning services for bio-ontologies. Aber-OWL consists of an ontology repository, a set of web services and web interfaces that enable ontology-based semantic access to biological data and literature. Aber-OWL is freely available at http://aber-owl.net. Conclusions: Aber-OWL provides a framework for automatically accessing information that is annotated with ontologies or contains terms used to label classes in ontologies. When using Aber-OWL, access to ontologies and data annotated with them is not merely based on class names or identifiers but rather on the knowledge the ontologies contain and the inferences that can be drawn from it.

  12. Established Companies meet Start-ups : Case: A service to research developing business models in start-up hot spots around the globe

    OpenAIRE

    Eisenblätter, Simon

    2016-01-01

    This thesis presents a business model with the aim to improve conversation between traditional companies and newly established start-ups. The assumption that such conversation can be facilitated by scouting for innovation in start-up hot spots around the world, will be discussed throughout the paper. The purpose of this work is to lay out a plan which can be presented to a first range of possible customers, with the goal of negotiating a trial cooperation. Before introducing the busi...

  13. Building A Simulation Model For The Prediction Of Temperature Distribution In Pulsed Laser Spot Welding Of Dissimilar Low Carbon Steel 1020 To Aluminum Alloy 6061

    International Nuclear Information System (INIS)

    Yousef, Adel K. M.; Taha, Ziad A.; Shehab, Abeer A.

    2011-01-01

    This paper describes the development of a computer model used to analyze the heat flow during pulsed Nd: YAG laser spot welding of dissimilar metal; low carbon steel (1020) to aluminum alloy (6061). The model is built using ANSYS FLUENT 3.6 software where almost all the environments simulated to be similar to the experimental environments. A simulation analysis was implemented based on conduction heat transfer out of the key hole where no melting occurs. The effect of laser power and pulse duration was studied.Three peak powers 1, 1.66 and 2.5 kW were varied during pulsed laser spot welding (keeping the energy constant), also the effect of two pulse durations 4 and 8 ms (with constant peak power), on the transient temperature distribution and weld pool dimension were predicated using the present simulation. It was found that the present simulation model can give an indication for choosing the suitable laser parameters (i.e. pulse durations, peak power and interaction time required) during pulsed laser spot welding of dissimilar metals.

  14. SpotADAPT

    DEFF Research Database (Denmark)

    Kaulakiene, Dalia; Thomsen, Christian; Pedersen, Torben Bach

    2015-01-01

    by Amazon Web Services (AWS). The users aiming for the spot market are presented with many instance types placed in multiple datacenters in the world, and thus it is difficult to choose the optimal deployment. In this paper, we propose the framework SpotADAPT (Spot-Aware (re-)Deployment of Analytical...... of typical analytical workloads and real spot price traces. SpotADAPT's suggested deployments are comparable to the theoretically optimal ones, and in particular, it shows good cost benefits for the budget optimization -- on average SpotADAPT is at most 0.3% more expensive than the theoretically optimal...

  15. Trust but Verify: a spot check for the new stratified model of upper mantle anisotropy beneath North America

    Science.gov (United States)

    Levin, V. L.; Yuan, H.

    2011-12-01

    (Palisades, NY; Standing Stone, PA), suggesting a presence of a regional anisotropic feature. Both the depth and the orientation of anisotropy show reasonable agreement with the "spot" values in the new 3D model. Preliminary modeling of shear-wave splitting observations using the cross-convolution method (Menke et al. 2003; Yuan et al. 2008) shows a strong preference for a stratified two-layer anisotropic domain beneath HRV. At the same time, specific parameters (depth, symmetry axes direction, strength of anisotropy) appear to be sensitive to both data selection and to modeling strategy. Inverting a set of core-refracted phases (SKS and SKKS) with the help of a ray-based algorithm that neglects multiples we converge on models that differ considerably from Levin et al. (1999) results, and also from values in the Yuan et al. (2011) model. Use of a reflectivity algorithm leads to results more consistent with past finding and the model. In the presentation we will explore the relative importance of synthetic seismogram algorithms, data set (e.g., inclusion of deep-focus S waves), and overall assumptions about the anisotropy distribution (e.g., vertical vs. lateral variation).

  16. Using a cross-model loadings plot to identify protein spots causing 2-DE gels to become outliers in PCA

    DEFF Research Database (Denmark)

    Kristiansen, Luise Cederkvist; Jacobsen, Susanne; Jessen, Flemming

    2010-01-01

    The multivariate method PCA is an exploratory tool often used to get an overview of multivariate data, such as the quantified spot volumes of digitized 2-DE gels. PCA can reveal hidden structures present in the data, and thus enables identification of potential outliers and clustering. Based on PCA...

  17. Spot protein-creatinine ratio and spot albumin-creatinine ratio in the assessment of pre-eclampsia: a diagnostic accuracy study with decision-analytic model-based economic evaluation and acceptability analysis.

    Science.gov (United States)

    Waugh, Jason; Hooper, Richard; Lamb, Edmund; Robson, Stephen; Shennan, Andrew; Milne, Fiona; Price, Christopher; Thangaratinam, Shakila; Berdunov, Vladislav; Bingham, Jenn

    2017-10-01

    The National Institute for Health and Care Excellence (NICE) guidelines highlighted the need for 'large, high-quality prospective studies comparing the various methods of measuring proteinuria in women with new-onset hypertensive disorders during pregnancy'. The primary objective was to evaluate quantitative assessments of spot protein-creatinine ratio (SPCR) and spot albumin-creatinine ratio (SACR) in predicting severe pre-eclampsia (PE) compared with 24-hour urine protein measurement. The secondary objectives were to investigate interlaboratory assay variation, to evaluate SPCR and SACR thresholds in predicting adverse maternal and fetal outcomes and to assess the cost-effectiveness of these models. This was a prospective diagnostic accuracy cohort study, with decision-analytic modelling and a cost-effectiveness analysis. The setting was 36 obstetric units in England, UK. Pregnant women (aged ≥ 16 years), who were at > 20 weeks' gestation with confirmed gestational hypertension and trace or more proteinuria on an automated dipstick urinalysis. Women provided a spot urine sample for protein analysis (the recruitment sample) and were asked to collect a 24-hour urine sample, which was stored for secondary analysis. A further spot sample of urine was taken immediately before delivery. Outcome data were collected from hospital records. There were four index tests on a spot sample of urine: (1) SPCR test (conducted at the local laboratory); (2) SPCR test [conducted at the central laboratory using the benzethonium chloride (BZC) assay]; (3) SPCR test [conducted at the central laboratory using the pyrogallol red (PGR) assay]; and (4) SACR test (conducted at the central laboratory using an automated chemistry analyser). The comparator tests on 24-hour urine collection were a central test using the BZC assay and a central test using the PGR assay. The primary reference standard was the NICE definition of severe PE. Secondary reference standards were a clinician

  18. Chapter 13. Current management situation: Great gray owls

    Science.gov (United States)

    Jon Verner

    1994-01-01

    The breeding range of great gray owls (Strix nebulosa) in the United States includes portions of Alaska, mountains in the western United States including portions of the Cascades and Sierra Nevada ranges and the northern Rockies, and portions of Minnesota, Michigan, Wisconsin, and New York (see Chapter 14 and Map 3). The species is sometimes observed...

  19. Conflict Resolution in Partially Ordered OWL DL Ontologies

    NARCIS (Netherlands)

    Ji, Q.; Gao, Z.; Huang, Z.

    2014-01-01

    Inconsistency handling in OWL DL ontologies is an important problem because an ontology can easily be inconsistent when it is generated or modified. Current approaches to dealing with inconsistent ontologies often assume that there exists a total order over axioms and use such an order to select

  20. Representing chemicals using OWL, description graphs and rules

    CSIR Research Space (South Africa)

    Hastings, J

    2010-06-01

    Full Text Available OWL, Description Graphs and Rules Janna Hastings1;2;3?, Michel Dumontier4, Duncan Hull1, Matthew Horridge5, Christoph Steinbeck1, Ulrike Sattler5, Robert Stevens5, Tertia H orne2, and Katarina Britz2;3 1 European Bioinformatics Institute, UK 2...

  1. Visual search in barn owls: Task difficulty and saccadic behavior.

    Science.gov (United States)

    Orlowski, Julius; Ben-Shahar, Ohad; Wagner, Hermann

    2018-01-01

    How do we find what we are looking for? A target can be in plain view, but it may be detected only after extensive search. During a search we make directed attentional deployments like saccades to segment the scene until we detect the target. Depending on difficulty, the search may be fast with few attentional deployments or slow with many, shorter deployments. Here we study visual search in barn owls by tracking their overt attentional deployments-that is, their head movements-with a camera. We conducted a low-contrast feature search, a high-contrast orientation conjunction search, and a low-contrast orientation conjunction search, each with set sizes varying from 16 to 64 items. The barn owls were able to learn all of these tasks and showed serial search behavior. In a subsequent step, we analyzed how search behavior of owls changes with search complexity. We compared the search mechanisms in these three serial searches with results from pop-out searches our group had reported earlier. Saccade amplitude shortened and fixation duration increased in difficult searches. Also, in conjunction search saccades were guided toward items with shared target features. These data suggest that during visual search, barn owls utilize mechanisms similar to those that humans use.

  2. Brominated flame retardants in Belgian little owl (Athene noctua) eggs

    Energy Technology Data Exchange (ETDEWEB)

    Jaspers, V.; Covaci, A.; Maervoet, J.; Dauwe, T.; Schepens, P.; Eens, M. [Antwerp Univ. (Belgium)

    2004-09-15

    Since the 1960s, polybrominated diphenylethers (PBDEs), a class of brominated flame retardants (BFRs), are widely used in textiles, plastics, electronic equipment and other materials. Their massive use has led to the ubiquitous presence of PBDEs in the environment and in biota in which the PBDE levels seem to increase rapidly. High concentrations of some congeners may cause adverse effects in both wildlife and in human populations1 and this has led to the growing concern of scientists over the last decade and to the need for more data on environmental levels of PBDEs. The little owl (Athene noctua) is a small sedentary predator, which makes it a very suitable biomonitoring species. This owl species feeds on a variety of preys, including small mammals and birds, reptiles, amphibians, earthworms and beetles, depending on the season and the local circumstances. Because very limited information is available about contamination levels in the little owl, a study was conducted to determine the concentrations of PBDEs, polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in deserted or addled eggs of little owls in Belgium. Eggs have been used successfully as a monitoring tool for persistent organic pollutants (POPs) in several studies. Although the analysis of POPs in deserted or addled eggs has clear limitations, these can be partially avoided by analysing only highly persistent components, for which the original composition will not change due to 'posthatching' microbiological degradation.

  3. Variation in working effort in Danish Little Owls Athene noctua

    DEFF Research Database (Denmark)

    Holsegård-Rasmussen, Miriam H.; Sunde, Peter; Thorup, K.

    2009-01-01

    with extinction. The study is based on 143 one-hour surveys of breeding and 274 surveys of non-breeding Little Owls (27 territorial individuals on 14 territories). Working effort is calculated as the total linear distance between all observed consecutive telemetry fixes during one-hour surveys (Minimum Flight...

  4. DIP: A defeasible-inference platform for OWL ontologies

    CSIR Research Space (South Africa)

    Meyer, T

    2014-07-01

    Full Text Available unpublished. We present a defeasible-reasoning system for OWL ontologies demonstrating that we need not devise new decision procedures for certain preferential DLs. Our reasoning procedures are composed purely of classical DL decision steps which allows us...

  5. Methods and materials for capturing and monitoring flammulated owls

    Science.gov (United States)

    Richard T. Reynolds; Brian D. Linkhart

    1984-01-01

    Techniques for locating, capturing, and monitoring activities and movements of Flammulated Owls were developed during four years of study. Adults responded to imitated territorial song throughout the nesting season. Nests were found by noting vocalizations and behaviors associated with courtship-feeding and food transfers between the sexes. After fledging, broods were...

  6. New Eimeria species from the snowy owl (Nyctea scandiaca)

    Czech Academy of Sciences Publication Activity Database

    Volf, J.; Koudela, Břetislav; Modrý, D.

    1998-01-01

    Roč. 45, č. 1 (1998), s. 8 ISSN 1066-5234. [New Eimeria species from the snowy owl (Nyctea scandiaca). 01.01.1998-02.01.1998, Praha] R&D Projects: GA MŠk 8111231 Subject RIV: fp - Other Medical Disciplines

  7. Reproductive working effort in Danish little owl (Athene noctua)

    DEFF Research Database (Denmark)

    Holsegård-Rasmussen, M.; Sunde, P.; Thorup, K.

    Reduced reproductive success, caused by energy constraints during breeding, is suspected to be one of the reasons for an ongoing decline in the Danish population of little owls (Athene noctua). To measure any food stress during the breeding period, working effort was defined as the minimum flight...... distance (the linear distance between consecutive telemetry fixes) during one-hour surveys of radio tagged individuals....

  8. Poisson's spot and Gouy phase

    Science.gov (United States)

    da Paz, I. G.; Soldati, Rodolfo; Cabral, L. A.; de Oliveira, J. G. G.; Sampaio, Marcos

    2016-12-01

    Recently there have been experimental results on Poisson spot matter-wave interferometry followed by theoretical models describing the relative importance of the wave and particle behaviors for the phenomenon. We propose an analytical theoretical model for Poisson's spot with matter waves based on the Babinet principle, in which we use the results for free propagation and single-slit diffraction. We take into account effects of loss of coherence and finite detection area using the propagator for a quantum particle interacting with an environment. We observe that the matter-wave Gouy phase plays a role in the existence of the central peak and thus corroborates the predominantly wavelike character of the Poisson's spot. Our model shows remarkable agreement with the experimental data for deuterium (D2) molecules.

  9. Rocky Mountain Spotted Fever

    Science.gov (United States)

    ... with facebook share with twitter share with linkedin Rocky Mountain Spotted Fever Credit: CDC A male cayenne tick, Amblyomma cajennense, ... and New Mexico. Why Is the Study of Rocky Mountain Spotted Fever a Priority for NIAID? Tickborne diseases are becoming ...

  10. Using population viability analysis, genomics, and habitat suitability to forecast future population patterns of Little Owl Athene noctua across Europe.

    Science.gov (United States)

    Andersen, Line Holm; Sunde, Peter; Pellegrino, Irene; Loeschcke, Volker; Pertoldi, Cino

    2017-12-01

    The agricultural scene has changed over the past decades, resulting in a declining population trend in many species. It is therefore important to determine the factors that the individual species depend on in order to understand their decline. The landscape changes have also resulted in habitat fragmentation, turning once continuous populations into metapopulations. It is thus increasingly important to estimate both the number of individuals it takes to create a genetically viable population and the population trend. Here, population viability analysis and habitat suitability modeling were used to estimate population viability and future prospects across Europe of the Little Owl Athene noctua , a widespread species associated with agricultural landscapes. The results show a high risk of population declines over the coming 100 years, especially toward the north of Europe, whereas populations toward the southeastern part of Europe have a greater probability of persistence. In order to be considered genetically viable, individual populations must count 1,000-30,000 individuals. As Little Owl populations of several countries count <30,000, and many isolated populations in northern Europe count <1,000 individuals, management actions resulting in exchange of individuals between populations or even countries are probably necessary to prevent losing <1% genetic diversity over a 100-year period. At a continental scale, a habitat suitability analysis suggested Little Owl to be affected positively by increasing temperatures and urban areas, whereas an increased tree cover, an increasing annual rainfall, grassland, and sparsely vegetated areas affect the presence of the owl negatively. However, the low predictive power of the habitat suitability model suggests that habitat suitability might be better explained at a smaller scale.

  11. Barn Owl (Tyto alba) and Long-Eared Owl (Asio otus) mortality along motorways in Bourgogne-Champagne: report and suggestions

    Science.gov (United States)

    Hugues Baudvin

    1997-01-01

    The purpose of the study was to find where and why two species of owls were killed by traffic along motorways. Three different factors have an important influence on the mortality of the two owl species: the biotops crossed by motorways, the road elevation and the presence of small rodents, the Common Vole (Microtus arvalis) being most numerous. In...

  12. 77 FR 12985 - Proposed Revised Habitat for the Spotted Owl: Minimizing Regulatory Burdens

    Science.gov (United States)

    2012-03-05

    ... enhance forest resilience. In order to avoid unnecessary costs and burdens and to advance the principles... activity in areas of critical habitat, in accordance with the scientific principles of active forestry... science and economics, including those comments that suggest potential methods for minimizing regulatory...

  13. Realized population change for long-term monitoring: California spotted owl case study

    Science.gov (United States)

    Mary M. Conner; John J. Keane; Claire V. Gallagher; Gretchen Jehle; Thomas E. Munton; Paula A. Shaklee; Ross A. Gerrard

    2013-01-01

    The annual rate of population change (λt) is a good metric for evaluating population performance because it summarizes survival and recruitment rates and can be used for open populations. Another measure of population performance, realized population change (Δt...

  14. Ecological responses by Mexican spotted owls to environmental variation in the Sacramento Mountains, New Mexico

    Science.gov (United States)

    James P. Ward

    2001-01-01

    Understanding the influence of environmental variation on population processes is a fundamental requisite for devising strategies that conserve species. A common tactic for conserving raptor populations is to maintain or manipulate habitat conditions that maintain or increase availability of prey species. A primary purpose of this investigation was to...

  15. 76 FR 37141 - Notice of Availability for Comment: Draft Recovery Plan, First Revision; Mexican Spotted Owl

    Science.gov (United States)

    2011-06-24

    ....gov/recovery/index.html#plans . Alternatively, you may contact the Arizona Ecological Services Office... Ecological Services Office at the above address; Fax: (602) 242-2513; or E-mail: http://www.fws.gov/southwest.... SUPPLEMENTARY INFORMATION: Background Recovery of endangered or threatened animals and plants to the point where...

  16. 77 FR 74688 - Final Recovery Plan, First Revision; Mexican Spotted Owl

    Science.gov (United States)

    2012-12-17

    ... Arizona, Colorado, New Mexico, Texas, and Utah, and south through the Sierra Madre Occidental and Sierra... plants. ADDRESSES: If you wish to view the recovery plan, you may obtain a copy by any one of the... recovery plan. Background Recovery of endangered or threatened animals and plants to the point where they...

  17. Thinning effects on spotted owl prey and other forest-dwelling small mammals

    Science.gov (United States)

    Todd M. Willson; Eric D. Forsman

    2013-01-01

    Th inning has been promoted as a method for accelerating the development of late-seral habitat and improving the overall health and function of young forests in the Pacifi c Northwest. Population studies have shown early and positive responses to thinning by some small forest-floor mammals (primarily mice, terrestrial voles, and shrews). However, thinning reduces the...

  18. SERS Assay for Copper(II) Ions Based on Dual Hot-Spot Model Coupling with MarR Protein: New Cu2+-Specific Biorecognition Element.

    Science.gov (United States)

    Wang, Yulong; Su, Zhenhe; Wang, Limin; Dong, Jinbo; Xue, Juanjuan; Yu, Jiao; Wang, Yuan; Hua, Xiude; Wang, Minghua; Zhang, Cunzheng; Liu, Fengquan

    2017-06-20

    We have developed a rapid and ultrasensitive surface-enhanced Raman scattering (SERS) assay for Cu 2+ detection using the multiple antibiotic resistance regulator (MarR) as specific bridging molecules in a SERS hot-spot model. In the assay, Cu 2+ induces formation of MarR tetramers, which provide Au nanoparticle (NP)-AuNP bridges, resulting in the formation of SERS hot spots. 4-Mercaptobenzoic acid (4-MBA) was used as a Raman reporter. The addition of Cu 2+ increased the Raman intensity of 4-MBA. Use of a dual hot-spot signal-amplification strategy based on AuNP-AgNP heterodimers combined through antigen-antibody reactions increased the sensitivity of the sensing platform by 50-fold. The proposed method gave a linear response for Cu 2+ detection in the range of 0.5-1000 nM, with a detection limit of 0.18 nM, which is 5 orders of magnitude lower than the U.S. Environmental Protection Agency limit for Cu 2+ in drinking water (20 μM). In addition, all analyses can be completed in less than 15 min. The high sensitivity, high specificity, and rapid detection capacity of the SERS assay therefore provide a combined advantage over current assays.

  19. The Harry Potter effect: The rise in trade of owls as pets in Java and Bali, Indonesia

    Directory of Open Access Journals (Sweden)

    Vincent Nijman

    2017-07-01

    Full Text Available Hundreds of species of wild-caught birds are offered for sale in the bird markets of Java and Bali, Indonesia, to meet the demand for the largely-domestic pet and songbird trade. In the past, owls were offered only in very small numbers in these bird markets but since the release of the Harry Potter series in Indonesia in the early 2000s their popularity as pets has increased. Whereas in the past owls were collective known as Burung Hantu (“Ghost birds”, in the bird markets they are now commonly referred to as Burung Harry Potter (“Harry Potter birds”. We made a retrospective quantitative assessment of the abundance of owls in the bird markets (1979–2010 and conducted 109 surveys in 20 bird markets in 2012–2016 to quantify owls in trade. In the 1980s, 1990s and early 2000s owls were rarely recorded in Indonesia's bird markets, typically one or two and up to five per survey, and frequently no owls were recorded at all. The trade was largely confined to small scops owls. In the late 2000s more species were offered for sale, including barn and bay owls, and larger owl species such as wood-owls, eagle-owls and fish-owls; typically 10 + owls were observed per survey. In recent years, the number of owl species increased even more, and on average we recorded 17 owls per survey, yielding a total of 1810 owls, and in >90% of the surveys owls were present. In the larger bird markets in Jakarta and Bandung typically 30 to 60 owls are on offer of up to 8 species at a time. The number of owls as a proportion of all birds in the markets increased from 0.43% post 2008, suggesting a delayed Harry Potter effect. Over this period, common species have become cheaper and less common ones have become more expensive. The owls are largely, if not exclusively, wild-caught and are sold into the domestic pet market. The release of Harry Potter films and novels in Indonesia coincided with the rise of the Internet and social media and, with some delay, the

  20. Effects of radiotransmitter necklaces on behaviors of adult male western burrowing owls

    Science.gov (United States)

    Chipman, E.D.; McIntyre, N.E.; Ray, J.D.; Wallace, M.C.; Boal, C.W.

    2007-01-01

    We studied the behavioral effects of necklace-style radiotransmitters on breeding male western burrowing owls (Athene cunicularia hypugaea) in 2 areas of northwestern Texas, USA, in 2004 and 2005. We tested the hypothesis that transmittered owls would spend time interacting with their necklaces and as a result spend less time in vigilance and resting activities than would nontransmittered owls. Nontransmittered owls (n = 6) spent significantly more time being vigilant (P = 0.007) than did transmittered owls (n = 3) in 2004, who spent significant amounts of time interacting with their necklaces. In 2005, behaviors of transmittered owls (n = 8) were significantly different (P of time interacting with their necklaces, they appeared to habituate to the presence of the transmitters within a relatively short period (<1 week), and necklaces did not affect survivorship or fitness in the short-term.

  1. Burrowing owl nesting productivity: A comparison between artificial and natural burrows on and off golf courses

    Science.gov (United States)

    Smith, M.D.; Conway, C.J.; Ellis, L.A.

    2005-01-01

    Burrowing owl (Athene cunicularia) populations are declining in many portions of their range, and lack of suitable nesting burrows is thought to be one reason for observed declines. Burrowing owls are attracted to golf courses because the birds generally nest and forage in short-grass, open areas, yet golf courses seldom have suitable nesting burrows. We examined the efficacy of installing artificial nesting burrows on golf courses as a way to help restore local burrowing owl populations. From 2001-2004 we monitored over 175 natural burrows off golf courses, 14 natural burrows on golf courses, 86 artificial burrows off golf courses, and 130 artificial burrows on golf courses. Owls located and used 8 of the 130 artificial burrows installed on golf courses (4 were used as nests). Owls selected burrows that were closer to existing natural burrows, farther from maintained areas (areas receiving turf maintenance by golf course staff), and farther from sprinkler heads. All 4 of the artificial burrows used as nests successfully fledged young, and annual site fidelity for owls nesting on golf courses was higher than for owls nesting off golf courses. However, annual fecundity of owls nesting on golf courses was lower than that of owls nesting off golf courses. If golf courses have sufficiently large nonmaintained areas and there are nesting owls nearby, course managers potentially can help in restoring local burrowing owl populations by installing artificial nesting burrows on the periphery of the course. However, the low fecundity on golf courses reported here should be more thoroughly examined before artificial burrows are used to attract owls to golf courses.

  2. Integrating reasoning and clinical archetypes using OWL ontologies and SWRL rules.

    Science.gov (United States)

    Lezcano, Leonardo; Sicilia, Miguel-Angel; Rodríguez-Solano, Carlos

    2011-04-01

    Semantic interoperability is essential to facilitate the computerized support for alerts, workflow management and evidence-based healthcare across heterogeneous electronic health record (EHR) systems. Clinical archetypes, which are formal definitions of specific clinical concepts defined as specializations of a generic reference (information) model, provide a mechanism to express data structures in a shared and interoperable way. However, currently available archetype languages do not provide direct support for mapping to formal ontologies and then exploiting reasoning on clinical knowledge, which are key ingredients of full semantic interoperability, as stated in the SemanticHEALTH report [1]. This paper reports on an approach to translate definitions expressed in the openEHR Archetype Definition Language (ADL) to a formal representation expressed using the Ontology Web Language (OWL). The formal representations are then integrated with rules expressed with Semantic Web Rule Language (SWRL) expressions, providing an approach to apply the SWRL rules to concrete instances of clinical data. Sharing the knowledge expressed in the form of rules is consistent with the philosophy of open sharing, encouraged by archetypes. Our approach also allows the reuse of formal knowledge, expressed through ontologies, and extends reuse to propositions of declarative knowledge, such as those encoded in clinical guidelines. This paper describes the ADL-to-OWL translation approach, describes the techniques to map archetypes to formal ontologies, and demonstrates how rules can be applied to the resulting representation. We provide examples taken from a patient safety alerting system to illustrate our approach. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. A Numerical Study of Aerodynamic Performance and Noise of a Bionic Airfoil Based on Owl Wing

    Directory of Open Access Journals (Sweden)

    Xiaomin Liu

    2014-08-01

    Full Text Available Noise reduction and efficiency enhancement are the two important directions in the development of the multiblade centrifugal fan. In this study, we attempt to develop a bionic airfoil based on the owl wing and investigate its aerodynamic performance and noise-reduction mechanism at the relatively low Reynolds number. Firstly, according to the geometric characteristics of the owl wing, a bionic airfoil is constructed as the object of study at Reynolds number of 12,300. Secondly, the large eddy simulation (LES with the Smagorinsky model is adopted to numerically simulate the unsteady flow fields around the bionic airfoil and the standard NACA0006 airfoil. And then, the acoustic sources are extracted from the unsteady flow field data, and the Ffowcs Williams-Hawkings (FW-H equation based on Lighthill's acoustic theory is solved to predict the propagation of these acoustic sources. The numerical results show that the lift-to-drag ratio of bionic airfoil is higher than that of the traditional NACA 0006 airfoil because of its deeply concave lower surface geometry. Finally, the sound field of the bionic airfoil is analyzed in detail. The distribution of the A-weighted sound pressure levels, the scaled directivity of the sound, and the distribution of dP/dt on the airfoil surface are provided so that the characteristics of the acoustic sources could be revealed.

  4. Spatial behaviour of little owls (Athene noctua) in a decreasing farmland population in Denmark

    DEFF Research Database (Denmark)

    Sunde, P.; Thorup, K.; Jacobsen, L. B.

    We describe basic spatial behaviour and social organisation in the small and declining Danish population of little owls. The behaviour was mainly studied using radio tracking during 2005-2007 of 14 pairs of little owls, representing a total of 29 individuals.......We describe basic spatial behaviour and social organisation in the small and declining Danish population of little owls. The behaviour was mainly studied using radio tracking during 2005-2007 of 14 pairs of little owls, representing a total of 29 individuals....

  5. Short-eared Owl (Asio flammeus surveys in the North American Intermountain West: utilizing citizen scientists to conduct monitoring across a broad geographic scale

    Directory of Open Access Journals (Sweden)

    Robert A. Miller

    2016-06-01

    Full Text Available The Short-eared Owl (Asio flammeus is an open-country species breeding in the northern United States and Canada, and has likely experienced a long-term, range-wide, and substantial decline. However, the cause and magnitude of the decline is not well understood. We set forth to address the first two of six previously proposed conservation priorities to be addressed for this species: (1 better define habitat use and (2 improve population monitoring. We recruited 131 volunteers to survey over 6.2 million ha within the state of Idaho for Short-eared Owls during the 2015 breeding season. We surveyed 75 transects, 71 of which were surveyed twice, and detected Short-eared Owls on 27 transects. We performed multiscale occupancy modeling to identify habitat associations, and performed multiscale abundance modeling to generate a state-wide population estimate. Our results suggest that within the state of Idaho, Short-eared Owls are more often found in areas with marshland or riparian habitat or areas with greater amounts of sagebrush habitat at the 1750 ha transect scale. At the 50 ha point scale, Short-eared Owls tend to associate positively with fallow and bare dirt agricultural land and negatively with grassland. Cropland was not chosen at the broader transect scale suggesting that Short-eared Owls may prefer more heterogeneous landscapes. On the surface our results may seem contradictory to the presumed land use by a "grassland" species; however, the grasslands of the Intermountain West, consisting largely of invasive cheatgrass (Bromus tectorum, lack the complex structure shown to be preferred by these owls. We suggest the local adaptation to agriculture represents the next best habitat to their historical native habitat preferences. Regardless, we have confirmed regional differences that should be considered in conservation planning for this species. Last, our results demonstrate the feasibility, efficiency, and effectiveness of utilizing public

  6. SU-D-BRE-06: Modeling the Dosimetric Effects of Volumetric and Layer-Based Repainting Strategies in Spot Scanning Proton Treatment Plans

    International Nuclear Information System (INIS)

    Johnson, J E; Beltran, C; Herman, M G; Kruse, J J

    2014-01-01

    Purpose: To compare multiple repainting techniques as strategies for mitigating the interplay effect in free-breathing, spot scanning proton plans. Methods: An analytic routine modeled three-dimensional dose distributions of pencil-beam proton plans delivered to a moving target. The interplay effect was studied in subsequent calculations by modeling proton delivery from a clinical synchrotron based spot scanning system and respiratory target motion, patterned from surrogate breathing traces from clinical 4DCT scans and normalized to nominal 0.5 and 1 cm amplitudes. Two distinct repainting strategies were modeled. In idealized volumetric repainting, the plan is divided up and delivered multiple times successively, with each instance only delivering a fraction of the total MU. Maximum-MU repainting involves delivering a fixed number of MU per spot and repeating a given energy layer until the prescribed MU are reached. For each of 13 patient breathing traces, the dose was computed for up to four volumetric repaints and an array of maximum-MU values. Delivery strategies were inter-compared based on target coverage, dose homogeneity, and delivery time. Results: Increasing levels of repainting generally improved plan quality and reduced dosimetric variability at the expense of longer delivery time. Motion orthogonal to the scan direction yielded substantially greater dose deviations than motion parallel to the scan direction. For a fixed delivery time, maximum-MU repainting was most effective relative to idealized volumetric repainting at small maximum-MU values. For 1 cm amplitude motion orthogonal to the scan direction, the average homogeneity metric (D5 – D95)[%] of 23.4% was reduced to 7.6% with a 168 s delivery using volumetric repainting compared with 8.7% in 157.2 s for maximum-MU repainting. The associated static target homogeneity metric was 2.5%. Conclusion: Maximum-MU repainting can provide a reasonably effective alternative to volumetric repainting for

  7. Reproduction in eastern screech-owls fed selenium

    Science.gov (United States)

    Wiemeyer, Stanley N.; Hoffman, D.J.

    1996-01-01

    Raptors are occasionally exposed to excessive selenium from contaminated prey, but the effects of this exposure on reproduction are unknown. Therefore, we fed captive eastern screech-owls (Otus asio) diets containing 0, 4.4, or 13.2 ppm (wet wt) added selenium in the form of seleno-DL-methionine. Adult mass at sacrifice and reproductive success of birds receiving 13.2 ppm selenium were depressed (P biochemistries indicative of oxidative stress were affected (P < 0.05) in 5-day-old nestlings from parents fed 4.4 ppm selenium and included a 19% increase in glutathione peroxidase activity, a 43% increase in the ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH), and a 17% increase in lipid peroxidation. Based on reproductive effects relative to dietary exposure, sensitivity of eastern screech-owls to selenium was similar to that of black-crowned night-herons (Nycticorax nycticorax) but less than that of mallards (Anas platyrhynchos).

  8. Airborne ocean water lidar (OWL) real time processor (RTP)

    Science.gov (United States)

    Hryszko, M.

    1995-03-01

    The Hyperflo Real Time Processor (RTP) was developed by Pacific-Sierra Research Corporation as a part of the Naval Air Warfare Center's Ocean Water Lidar (OWL) system. The RTP was used for real time support of open ocean field tests at Barbers Point, Hawaii, in March 1993 (EMERALD I field test), and Jacksonville, Florida, in July 1994 (EMERALD I field test). This report describes the system configuration, and accomplishments associated with the preparation and execution of these exercises. This document is intended to supplement the overall test reports and provide insight into the development and use of the PTP. A secondary objective is to provide basic information on the capabilities, versatility and expandability of the Hyperflo RTP for possible future projects. It is assumed herein that the reader has knowledge of the OWL system, field test operations, general lidar processing methods, and basic computer architecture.

  9. Monte Carlo modeling of small photon fields: Quantifying the impact of focal spot size on source occlusion and output factors, and exploring miniphantom design for small-field measurements

    International Nuclear Information System (INIS)

    Scott, Alison J. D.; Nahum, Alan E.; Fenwick, John D.

    2009-01-01

    The accuracy with which Monte Carlo models of photon beams generated by linear accelerators (linacs) can describe small-field dose distributions depends on the modeled width of the electron beam profile incident on the linac target. It is known that the electron focal spot width affects penumbra and cross-field profiles; here, the authors explore the extent to which source occlusion reduces linac output for smaller fields and larger spot sizes. A BEAMnrc Monte Carlo linac model has been used to investigate the variation in penumbra widths and small-field output factors with electron spot size. A formalism is developed separating head scatter factors into source occlusion and flattening filter factors. Differences between head scatter factors defined in terms of in-air energy fluence, collision kerma, and terma are explored using Monte Carlo calculations. Estimates of changes in kerma-based source occlusion and flattening filter factors with field size and focal spot width are obtained by calculating doses deposited in a narrow 2 mm wide virtual ''milliphantom'' geometry. The impact of focal spot size on phantom scatter is also explored. Modeled electron spot sizes of 0.4-0.7 mm FWHM generate acceptable matches to measured penumbra widths. However the 0.5 cm field output factor is quite sensitive to electron spot width, the measured output only being matched by calculations for a 0.7 mm spot width. Because the spectra of the unscattered primary (Ψ Π ) and head-scattered (Ψ Σ ) photon energy fluences differ, miniphantom-based collision kerma measurements do not scale precisely with total in-air energy fluence Ψ=(Ψ Π +Ψ Σ ) but with (Ψ Π +1.2Ψ Σ ). For most field sizes, on-axis collision kerma is independent of the focal spot size; but for a 0.5 cm field size and 1.0 mm spot width, it is reduced by around 7% mostly due to source occlusion. The phantom scatter factor of the 0.5 cm field also shows some spot size dependence, decreasing by 6% (relative) as

  10. Evaluation of the influence of double and triple Gaussian proton kernel models on accuracy of dose calculations for spot scanning technique.

    Science.gov (United States)

    Hirayama, Shusuke; Takayanagi, Taisuke; Fujii, Yusuke; Fujimoto, Rintaro; Fujitaka, Shinichiro; Umezawa, Masumi; Nagamine, Yoshihiko; Hosaka, Masahiro; Yasui, Keisuke; Omachi, Chihiro; Toshito, Toshiyuki

    2016-03-01

    The main purpose in this study was to present the results of beam modeling and how the authors systematically investigated the influence of double and triple Gaussian proton kernel models on the accuracy of dose calculations for spot scanning technique. The accuracy of calculations was important for treatment planning software (TPS) because the energy, spot position, and absolute dose had to be determined by TPS for the spot scanning technique. The dose distribution was calculated by convolving in-air fluence with the dose kernel. The dose kernel was the in-water 3D dose distribution of an infinitesimal pencil beam and consisted of an integral depth dose (IDD) and a lateral distribution. Accurate modeling of the low-dose region was important for spot scanning technique because the dose distribution was formed by cumulating hundreds or thousands of delivered beams. The authors employed a double Gaussian function as the in-air fluence model of an individual beam. Double and triple Gaussian kernel models were also prepared for comparison. The parameters of the kernel lateral model were derived by fitting a simulated in-water lateral dose profile induced by an infinitesimal proton beam, whose emittance was zero, at various depths using Monte Carlo (MC) simulation. The fitted parameters were interpolated as a function of depth in water and stored as a separate look-up table. These stored parameters for each energy and depth in water were acquired from the look-up table when incorporating them into the TPS. The modeling process for the in-air fluence and IDD was based on the method proposed in the literature. These were derived using MC simulation and measured data. The authors compared the measured and calculated absolute doses at the center of the spread-out Bragg peak (SOBP) under various volumetric irradiation conditions to systematically investigate the influence of the two types of kernel models on the dose calculations. The authors investigated the difference

  11. Thermal adaptiveness of plumage color in screech owls

    Science.gov (United States)

    Mosher, James A.; Henny, Charles J.

    1976-01-01

    Clinal variation in the relative proportions of red and gray plum- age phases in Screech Owls (Otus asio) was analyzed by Owen (1963) and Marshall (1967). This variation was well known prior to Owen's work, but was misinterpreted (Baird, et al. 1874, Hasbrouck 1893, Allen 1893).]Laurel VanCamp and Charles Henny (MS) have 30 years of data on a northern Ohio Screech Owl population. They observed an over- winter decline (from about 25% to 15%) in the proportion of red phase birds in the winter of 1951-52. This decline was correlated with a severe winter of above normal snowfall and below average temperatures. They examined banding and recovery data and found overwinter survival of red and gray birds to be the same except for this one severe winter when 44% more red phase birds were lost than grays (VanCamp and Henny MS). Differential mortality was reported by Gullion and Marshall (1968) for red and gray phase Ruffed Grouse (Bonasa umbellus) where snow conditions for roosting is apparently the critical factor for grouse overwinter survival and is related to predation. Snow- roosting has not, to our knowledge, been observed in Screech Owls. VanCamp and Henny (MS) discuss the observations of Ruffed Grouse and Screech Owls and suggest that possible thermoregulatory differences between red and gray phase birds could account for differential overwinter survival.Our objective was to test for differences between color phase in oxygen uptake at several ambient temperatures. We hypothesized that oxygen uptake would be greater by red phase birds, especially at lower temperatures.

  12. Barn Owl Productivity Response to Variability of Vole Populations.

    Directory of Open Access Journals (Sweden)

    Petr Pavluvčík

    Full Text Available We studied the response of the barn owl annual productivity to the common vole population numbers and variability to test the effects of environmental stochasticity on their life histories. Current theory predicts that temporal environmental variability can affect long-term nonlinear responses (e.g., production of young both positively and negatively, depending on the shape of the relationship between the response and environmental variables. At the level of the Czech Republic, we examined the shape of the relationship between the annual sum of fledglings (annual productivity and vole numbers in both non-detrended and detrended data. At the districts' level, we explored whether the degree of synchrony (measured by the correlation coefficient and the strength of the productivity response increase (measured by the regression coefficient in areas with higher vole population variability measured by the s-index. We found that the owls' annual productivity increased linearly with vole numbers in the Czech Republic. Furthermore, based on district data, we also found that synchrony between dynamics in owls' reproductive output and vole numbers increased with vole population variability. However, the strength of the response was not affected by the vole population variability. Additionally, we have shown that detrending remarkably increases the Taylor's exponent b relating variance to mean in vole time series, thereby reversing the relationship between the coefficient of variation and the mean. This shift was not responsible for the increased synchrony with vole population variability. Instead, we suggest that higher synchrony could result from high food specialization of owls on the common vole in areas with highly fluctuating vole populations.

  13. ANALYSIS OF A COLLECTION OF BARN OWL TYTO ALBA ...

    African Journals Online (AJOL)

    1969/70, birds made up 1,13 % of the total biomass, and in 1971, 4,75 %. Two birds, P loceus velatus and Que/ea quelea made up 4,55 % of the total biomass. .... Rate o/pellet casting. Table 3 gives the number of pellets collected at the roost and the number of owls present at the roost. TABLE 3. MEAN NUMBER OF ...

  14. Plasma parameters of the cathode spot explosive electron emission cell obtained from the model of liquid-metal jet tearing and electrical explosion

    Science.gov (United States)

    Tsventoukh, M. M.

    2018-05-01

    A model has been developed for the explosive electron emission cell pulse of a vacuum discharge cathode spot that describes the ignition and extinction of the explosive pulse. The pulse is initiated due to hydrodynamic tearing of a liquid-metal jet which propagates from the preceding cell crater boundary and draws the ion current from the plasma produced by the preceding explosion. Once the jet neck has been resistively heated to a critical temperature (˜1 eV), the plasma starts expanding and decreasing in density, which corresponds to the extinction phase. Numerical and analytical solutions have been obtained that describe both the time behavior of the pulse plasma parameters and their average values. For the cell plasma, the momentum per transferred charge has been estimated to be some tens of g cm/(s C), which is consistent with the known measurements of ion velocity, ion erosion rate, and specific recoil force. This supports the model of the pressure-gradient-driven plasma acceleration mechanism for the explosive cathode spot cells. The ohmic electric field within the explosive current-carrying plasma has been estimated to be some tens of kV/cm, which is consistent with the known experimental data on cathode potential fall and explosive cell plasma size. This supports the model that assumes the ohmic nature of the cathode potential fall in a vacuum discharge.

  15. A dominance hierarchy of auditory spatial cues in barn owls.

    Directory of Open Access Journals (Sweden)

    Ilana B Witten

    2010-04-01

    Full Text Available Barn owls integrate spatial information across frequency channels to localize sounds in space.We presented barn owls with synchronous sounds that contained different bands of frequencies (3-5 kHz and 7-9 kHz from different locations in space. When the owls were confronted with the conflicting localization cues from two synchronous sounds of equal level, their orienting responses were dominated by one of the sounds: they oriented toward the location of the low frequency sound when the sources were separated in azimuth; in contrast, they oriented toward the location of the high frequency sound when the sources were separated in elevation. We identified neural correlates of this behavioral effect in the optic tectum (OT, superior colliculus in mammals, which contains a map of auditory space and is involved in generating orienting movements to sounds. We found that low frequency cues dominate the representation of sound azimuth in the OT space map, whereas high frequency cues dominate the representation of sound elevation.We argue that the dominance hierarchy of localization cues reflects several factors: 1 the relative amplitude of the sound providing the cue, 2 the resolution with which the auditory system measures the value of a cue, and 3 the spatial ambiguity in interpreting the cue. These same factors may contribute to the relative weighting of sound localization cues in other species, including humans.

  16. CLINICAL EFFECT OF HEMOPARASITE INFECTIONS IN SNOWY OWLS ( BUBO SCANDIACUS).

    Science.gov (United States)

    Baker, Kendra C; Rettenmund, Christy L; Sander, Samantha J; Rivas, Anne E; Green, Kaitlin C; Mangus, Lisa; Bronson, Ellen

    2018-03-01

    Vector-borne hemoparasites are commonly found in avian species. Plasmodium spp., the causative agent of avian malaria, are intraerythrocytic parasites that can cause signs ranging from subclinical infection to severe acute disease. In raptor species, most hemoparasites are associated with subclinical infection and are generally not treated when seen on blood evaluation. This case series reviews five cases of hemoparasite infection in snowy owls ( Bubo scandiacus). These animals were infected with a variety of hemoparasites, including Plasmodium, Haemoproteus, and Leukocytozoon spp. Death of one of these birds due to hemoparasite burden led to a change in the monitoring for and treatment of subclinical hemoparasitic infections in this species. Three subsequently infected snowy owls have been treated with primaquine and chloroquine. The birds that were treated survived infection, and parasite burdens in peripheral blood diminished. Postulated reasons for increased morbidity and mortality associated with hemoparasitic infections in captive snowy owls, as opposed to other raptor species, include stress, concurrent disease, novel pathogen exposure, and elevated environmental temperatures.

  17. The cervical spine of the American barn owl (Tyto furcata pratincola: I. Anatomy of the vertebrae and regionalization in their S-shaped arrangement.

    Directory of Open Access Journals (Sweden)

    Markus Krings

    Full Text Available BACKGROUND: Owls possess an extraordinary neck and head mobility. To understand this mobility it is necessary to have an anatomical description of cervical vertebrae with an emphasis on those criteria that are relevant for head positioning. No functional description specific to owls is available. METHODOLOGY/PRINCIPAL FINDINGS: X-ray films and micro-CT scans were recorded from American barn owls (Tyto furcata pratincola and used to obtain three-dimensional head movements and three-dimensional models of the 14 cervical vertebrae (C1-C14. The diameter of the vertebral canal, the zygapophyseal protrusion, the distance between joint centers, and the pitching angle were quantified. Whereas the first two variables are purely osteological characteristics of single vertebrae, the latter two take into account interactions between vertebrae. These variables change in characteristic ways from cranial to caudal. The vertebral canal is wide in the cranial and caudal neck regions, but narrow in the middle, where both the zygapophyseal protrusion and the distance between joint centers are large. Pitching angles are more negative in the cranial and caudal neck regions than in the middle region. Cluster analysis suggested a complex regionalization. Whereas the borders (C1 and C13/C14 formed stable clusters, the other cervical vertebrae were sorted into 4 or 5 additional clusters. The borders of the clusters were influenced by the variables analyzed. CONCLUSIONS/SIGNIFICANCE: A statistical analysis was used to evaluate the regionalization of the cervical spine in the barn owl. While earlier measurements have shown that there appear to be three regions of flexibility of the neck, our indicators suggest 3-7 regions. These many regions allow a high degree of flexibility, potentially facilitating the large head turns that barn owls are able to make. The cervical vertebral series of other species should also be investigated using statistical criteria to further

  18. Observations of wintering Snowy Owls (Nyctea scandiaca) at Logan Airport, East Boston, Massachusetts from 1981-1997

    Science.gov (United States)

    Norman Smith

    1997-01-01

    Snowy Owls (Nyctea scandiaca) wintering at Logan International Airport were studied over the 15-year period of 1981-1997. Two-hundred twenty-seven Snowy Owls were banded and color-marked to examine the length of time individual birds stayed at this location and to track the movements elsewhere. Fifty-six owls were re-observed outside of the airport...

  19. West Nile virus and hemoparasites in captive snowy owls (Bubo scandiacus)--management strategies to optimize survival.

    Science.gov (United States)

    Harasym, Carol A

    2008-11-01

    In August 2005, 2 members of a group of 6 captive snowy owls (Bubo scandiacus) in central Saskatchewan died of West Nile virus infection. One of these owls and 3 of the remaining owls had significant numbers of circulating hemoparasites. Management strategies are suggested to reduce morbidity and mortality.

  20. West Nile virus and hemoparasites in captive snowy owls (Bubo scandiacus) — management strategies to optimize survival

    Science.gov (United States)

    Harasym, Carol A.

    2008-01-01

    In August 2005, 2 members of a group of 6 captive snowy owls (Bubo scandiacus) in central Saskatchewan died of West Nile virus infection. One of these owls and 3 of the remaining owls had significant numbers of circulating hemoparasites. Management strategies are suggested to reduce morbidity and mortality. PMID:19183740

  1. West Nile virus and hemoparasites in captive snowy owls (Bubo scandiacus) — management strategies to optimize survival

    OpenAIRE

    Harasym, Carol A.

    2008-01-01

    In August 2005, 2 members of a group of 6 captive snowy owls (Bubo scandiacus) in central Saskatchewan died of West Nile virus infection. One of these owls and 3 of the remaining owls had significant numbers of circulating hemoparasites. Management strategies are suggested to reduce morbidity and mortality.

  2. Flexible Generation of Pervasive Web Services using OSGi Declarative Services and OWL Ontologies

    DEFF Research Database (Denmark)

    Hansen, Klaus Marius; Zhang, Weishan; Fernandes, Joao

    2008-01-01

    There is a growing trend to deploy web services in pervasive computing environments. Implementing web services on networked, embedded devices leads to a set of challenges, including productivity of development, efficiency of web services, and handling of variability and dependencies of hardware...... and software platforms. To address these challenges, we developed a web service compiler called Limbo, in which Web Ontology Language (OWL) ontologies are used to make the Limbo compiler aware of its compilation context such as device hardware and software details, platform dependencies, and resource....../power consumption. The ontologies are used to configure Limbo for generating resource-efficient web service code. The architecture of Limbo follows the Blackboard architectural style and Limbo is implemented using the OSGi Declarative Services component model. The component model provides high flexibility...

  3. A Korean Space Situational Awareness Program : OWL Network

    Science.gov (United States)

    Park, J.; Choi, Y.; Jo, J.; Moon, H.; Im, H.; Park, J.

    2012-09-01

    We are going to present a brief introduction to the OWL (Optical Wide-field patroL) network, one of Korean space situational awareness facilities. Primary objectives of the OWL network are 1) to obtain orbital information of Korean domestic LEOs using optical method, 2) to monitor GEO-belt over territory of Korea, and 3) to alleviate collisional risks posed to Korean satellites from space debris. For these purposes, we are planning to build a global network of telescopes which consists of five small wide-field telescopes and one 2m class telescope. The network of small telescopes will be dedicated mainly to the observation of domestic LEOs, but many slots will be open to other scientific programs such as GRB follow-up observations. Main targets of 2m telescope not only include artificial objects such as GEO debris and LEO debris with low inclination and high eccentricity, but also natural objects such as near Earth asteroids. We expect to monitor space objects down to 10cm in size in GEO using the 2m telescope system. Main research topics include size distribution and evolution of space debris. We also expect to utilize this facility for physical characterization and population study of near Earth asteroids. The aperture size of the small telescope system is 0.5m with Rechey-Cretian configuration and its field of view is 1.75 deg x 1.75 deg. It is equipped with 4K CCD with 9um pixel size, and its plate scale is 1.3 arcsec/pixel. A chopper wheel is employed to maximize astrometric solutions in a single CCD frame, and a de-rotator is used to compensate field rotation of the alt-az type mount. We have designed a compact end unit in which three rotating parts (chopper wheel, filter wheel, de-rotator) and a CCD camera are integrated, and dedicated telescope/site control boards for the OWL network. The design of 2m class telescope is still under discussion yet is expected to be fixed in the first half of 2013 at the latest. The OWL network will be operated in a fully

  4. Crack imaging by pulsed laser spot thermography

    International Nuclear Information System (INIS)

    Li, T; Almond, D P; Rees, D A S; Weekes, B

    2010-01-01

    A surface crack close to a spot heated by a laser beam impedes lateral heat flow and produces alterations to the shape of the thermal image of the spot that can be monitored by thermography. A full 3D simulation has been developed to simulate heat flow from a laser heated spot in the proximity of a crack. The modelling provided an understanding of the ways that different parameters affect the thermal images of laser heated spots. It also assisted in the development of an efficient image processing strategy for extracting the scanned cracks. Experimental results show that scanning pulsed laser spot thermography has considerable potential as a remote, non-contact crack imaging technique.

  5. Flammulated, boreal, and great gray owls in the United States: A technical conservation assessment

    Science.gov (United States)

    G. D. Hayward; J. Verner

    1994-01-01

    Flammulated (Otus flammeolus), boreal (Aegolius funereus), and great gray (Strix nebulosa) owls occur over a broad portion of North America and each is designated as a "sensitive species" in four or more USDA Forest Service regions. The insectivorous flammulated owl is a neotropical migrant requiring...

  6. Chapter 11. Conservation status of boreal owls in the United States

    Science.gov (United States)

    Gregory D. Hayward

    1994-01-01

    Previous chapters outlined the biology and ecology of boreal owls as well as the ecology of important vegetation communities based on literature from North America and Europe. That technical review provides the basis to assess the current conservation status of boreal owls in the United States. By conservation status, we mean the demographic condition of the species as...

  7. Detecting West Nile virus in owls and raptors by an antigen-capture assay.

    Science.gov (United States)

    Gancz, Ady Y; Campbell, Douglas G; Barker, Ian K; Lindsay, Robbin; Hunter, Bruce

    2004-12-01

    We evaluated a rapid antigen-capture assay (VecTest) for detection of West Nile virus in oropharyngeal and cloacal swabs, collected at necropsy from owls (N = 93) and raptors (N = 27). Sensitivity was 93.5%-95.2% for northern owl species but raptors.

  8. Estimation of food consumption from pellets cast by captive Ural Owls (Strix uralensis)

    Science.gov (United States)

    Aki Higuchi; Manabu T. Abe

    1997-01-01

    There is considerable data in the literature on the diet of the Ural Owl (Strix uralensis) based on pellet analysis. Though it is possible to identify prey items by this method, the volume of food consumption is still unknown. The population of Ural Owls in Japan is declining due to the reduction of old-growth forest and the concurrent loss of...

  9. Using C-OWL for the Alignment and Merging of Medical Ontologies

    NARCIS (Netherlands)

    Stuckenschmidt, Heiner; van Harmelen, Frank; Serafini, Luciano; Bouquet, Paolo; Giunchiglia, Fausto

    2004-01-01

    A number of sophisticated medical ontologies have been created over the past years. With their de-velopment the need for supporting the alignment of different ontologies is gaining importance. We proposed C-OWL, an extension of the Web Ontology Language OWL that supports alignment mappings between

  10. Distribution, abundance, and habitat use of territorial male Boreal Owls (Aegolius funereus) in northeast Minnesota

    Science.gov (United States)

    William H. Lane; David E. Andersen; Thomas H. Nicholls

    1997-01-01

    We conducted nocturnal auditory surveys from 1987-1992 to determine the distribution, abundance, and habitat use of Boreal Owls (Aegolius funereus) in northeast Minnesota. We concentrated our efforts in areas where documented nesting attempts by the owls had occurred, along roadways maintained for winter-time access by motor vehicles, and by...

  11. Aber-OWL: a framework for ontology-based data access in biology

    KAUST Repository

    Hoehndorf, Robert; Slater, Luke; Schofield, Paul N; Gkoutos, Georgios V

    2015-01-01

    these ontologies relies on the use of automated reasoning. Results: We have developed the Aber-OWL infrastructure that provides reasoning services for bio-ontologies. Aber-OWL consists of an ontology repository, a set of web services and web interfaces that enable

  12. Reintroduction of captive-bred African Grass-Owls Tyto capensis ...

    African Journals Online (AJOL)

    This study represents the first attempt to determine post-release survival of a captive-bred owl in Africa. We released six captive-bred African Grass-Owls Tyto capensis into suitable habitat and, using radio telemetry, determined their daytime roost sites. One bird left the study area soon after release and did not yield data.

  13. Detecting West Nile Virus in Owls and Raptors by an Antigen-capture Assay

    OpenAIRE

    Gancz, Ady Y.; Campbell, Douglas G.; Barker, Ian K.; Lindsay, Robbin; Hunter, Bruce

    2004-01-01

    We evaluated a rapid antigen-capture assay (VecTest) for detection of West Nile virus in oropharyngeal and cloacal swabs, collected at necropsy from owls (N = 93) and raptors (N = 27). Sensitivity was 93.5%–95.2% for northern owl species but

  14. "Not in the Middle Ages"?: Alan Garner's "The Owl Service" and the Literature of Adolescence.

    Science.gov (United States)

    Hardwick, Paul

    2000-01-01

    Discusses connecting with the Middle Ages in adolescent fiction. Discusses how, in "The Owl Service," Garner addresses a relationship between adolescence in the late twentieth century and an aspect of the past--specifically the Middle Ages. Considers how "The Owl Service" is a story energized by myth, concerning the…

  15. Hot spot manifestation in eclipsing dwarf nova HT Cassiopeiae

    OpenAIRE

    Bakowska, K.; Olech, A.

    2014-01-01

    We report the detection of the hot spot in light curves of the eclipsing dwarf nova HT Cassiopeiae during its superoutburst in 2010 November. Analysis of eight reconstructed light curves of the hot spot eclipses showed directly that the brightness of the hot spot was changing significantly during the superoutburst. Thereby, detected hot spot manifestation in HT Cas is the newest observational evidence for the EMT model for dwarf novae.

  16. Spot market for uranium

    International Nuclear Information System (INIS)

    Colhoun, C.

    1982-01-01

    The spot market is always quoted for the price of uranium because little information is available about long-term contracts. A review of the development of spot market prices shows the same price curve swings that occur with all raw materials. Future long-term contracts will probably be lower to reflect spot market prices, which are currently in the real-value range of $30-$35. An upswing in the price of uranium could come in the next few months as utilities begin making purchases and trading from stockpiles. The US, unlike Europe and Japan, has already reached a supply and demand point where the spot market share is increasing. Forecasters cannot project the market price, they can only predict the presence of an oscillating spot or a secondary market. 5 figures

  17. Improved simulation method of automotive spot weld failure with an account of the mechanical properties of spot welds

    Science.gov (United States)

    Wu, H.; Meng, X. M.; Fang, R.; Huang, Y. F.; Zhan, S.

    2017-12-01

    In this paper, the microstructure and mechanical properties of spot weld were studied, the hardness of nugget and heat affected zone (HAZ) were also tested by metallographic microscope and microhardness tester. The strength of the spot weld with the different parts' area has been characterized. According to the experiments result, CAE model of spot weld with HAZ structure was established, and simulation results of different lap-shear CAE models were analyzed. The results show that the spot weld model which contained the HAZ has good performance and more suitable for engineering application in spot weld simulation.

  18. The influence of hunger on meal to pellet intervals in barred owls

    Science.gov (United States)

    Duke, G.E.; Fuller, M.R.; Huberty, B.J.

    1980-01-01

    1. Barred owls fed at a sub-maintenance (SM) level had significantly (P < 0.01) longer meal to pellet intervals (MPI)/g eaten/kg body weight (BW) than those fed at an above maintenance (AM) level; MPI/g per kg for owls fed at a maintenance (M) level was intermediate but significantly (P < 0.01) different from both SM and AM.2. During SM feeding, MPI/g per kg gradually increased.3. The proportion of a meal occurring in a pellet was less in “hungry” owls whether losing weight (SM) or gaining (AM) as compared to owls maintaining their normal body weight (M).4. SM fed owls appear to be able to increase digestion time as well as thoroughness of digestion.

  19. A Risk Assessment Model for Bacterial Leaf Spot of Pepper (Capsicum annuum), Caused by Xanthomonas euvesicatoria, Based on Concentrations of Macronutrients, Micronutrients, and Micronutrient Ratios.

    Science.gov (United States)

    Dutta, B; Langston, D B; Luo, X; Carlson, S; Kichler, J; Gitaitis, R

    2017-11-01

    The phytopathogenic bacterium Xanthomonas euvesicatoria causes bacterial leaf spot (BLS) of pepper and has a worldwide distribution. BLS is difficult to control and an integrated management strategy that incorporates crop rotation, use of clean seed and clean plants, weed control, resistant varieties, applications of bactericides, biocontrol agents, and systemic acquired resistance (SAR) inducers is generally recommended. However, even with that arsenal of weapons, BLS can still be responsible for severe losses under favorable environmental conditions. Thus, additional tools need to be added to an overall integrated management strategy to combat BLS. In this article, we developed several models from 2012 to 2014 that were based on how macronutrients, micronutrients, and micronutrient ratios affect BLS severity. Factors used to select a model for validation included highly significant P values, high adjusted R 2 values, low variance inflation factor values (macronutrient and micronutrient concentrations affect plant disease resistance genes in the SAR pathway.

  20. Selective predation of tawny owls (Strix aluco) on yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus)

    DEFF Research Database (Denmark)

    Sunde, Peter; Forsom, Heidi Malene; Al-Sabi, Mohammad Nafi Solaiman

    2012-01-01

    years by comparing prey from owl nests with live-trapped individuals. The owls killed significantly more male M.g. (73%) than females, but not more than expected from traps (57%). For A.f., owls selected adults in favour of subadults, and for adults, individuals with longer femurs. Adult males of A.......f. killed by owls had significantly heavier testes in relation their size than the trapped males. Prey selection did not correlate with size-adjusted body or spleen mass. Owl-killed A.f. had higher prevalences of the intestinal helminth Heligmosomoides sp. than trapped individuals, but hosted similar...

  1. An RDF/OWL knowledge base for query answering and decision support in clinical pharmacogenetics.

    Science.gov (United States)

    Samwald, Matthias; Freimuth, Robert; Luciano, Joanne S; Lin, Simon; Powers, Robert L; Marshall, M Scott; Adlassnig, Klaus-Peter; Dumontier, Michel; Boyce, Richard D

    2013-01-01

    Genetic testing for personalizing pharmacotherapy is bound to become an important part of clinical routine. To address associated issues with data management and quality, we are creating a semantic knowledge base for clinical pharmacogenetics. The knowledge base is made up of three components: an expressive ontology formalized in the Web Ontology Language (OWL 2 DL), a Resource Description Framework (RDF) model for capturing detailed results of manual annotation of pharmacogenomic information in drug product labels, and an RDF conversion of relevant biomedical datasets. Our work goes beyond the state of the art in that it makes both automated reasoning as well as query answering as simple as possible, and the reasoning capabilities go beyond the capabilities of previously described ontologies.

  2. Using Assertion Capabilities of an OWL-Based Ontology for Query Formulation

    CERN Document Server

    Munir, Kamran; Bloodsworth, Peter; McClatchey, Richard

    2008-01-01

    This paper reports on the development of a framework to assist users in formulating relational queries without requiring a complete knowledge of the information structure and access mechanisms to underlying data sources. The emphasis here is on exploiting the semantic relationships and assertion capabilities of OWL ontologies to assist clinicians in writing complex queries. This has been achieved using both a bottom-up and top-down approaches to build an ontology model to be the repository for complex end user queries. Relational database schemas are mapped into the newly generated ontology schema to reinforce the current domain ontology being developed. One of the key merits of this approach is that it does not require storing data interpretation, with the added advantage of even not storing database instances as part of the domain ontology, especially for systems with huge volume of data.

  3. Hyper-functioning Thyroid Nodule with Scintigraphic Owl's Eye Appearance

    International Nuclear Information System (INIS)

    Al-Kordi, R.S.; Elgazzar, A.H.

    2006-01-01

    Hyper-functioning thyroid nodules may produce various scintigraphic appearances on thyroid scans. Autonomously hyper functioning thyroid nodules invariably demonstrate degenerative changes. These changes may give rise to central or less commonly peripheral photopenic areas on a thyroid scan within otherwise a hot nodule. In this report we present a case of hyper functioning autonomous nodule with peripheral degeneration and residual central functioning tissue giving the appearance of an owl's eye. Although rare, this pattern can be seen in a variety of benign and malignant thyroid conditions. (author)

  4. Bootstrap Score Tests for Fractional Integration in Heteroskedastic ARFIMA Models, with an Application to Price Dynamics in Commodity Spot and Futures Markets

    DEFF Research Database (Denmark)

    Cavaliere, Giuseppe; Nielsen, Morten Ørregaard; Taylor, A.M. Robert

    Empirical evidence from time series methods which assume the usual I(0)/I(1) paradigm suggests that the efficient market hypothesis, stating that spot and futures prices of a commodity should cointegrate with a unit slope on futures prices, does not hold. However, these statistical methods...... fractionally integrated model we are able to find a body of evidence in support of the efficient market hypothesis for a number of commodities. Our new tests are wild bootstrap implementations of score-based tests for the order of integration of a fractionally integrated time series. These tests are designed...... principle do. A Monte Carlo simulation study demonstrates that very significant improvements infinite sample behaviour can be obtained by the bootstrap vis-à-vis the corresponding asymptotic tests in both heteroskedastic and homoskedastic environments....

  5. Mononucleosis spot test

    Science.gov (United States)

    Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...

  6. Arc cathode spots

    International Nuclear Information System (INIS)

    Schrade, H.O.

    1989-01-01

    Arc spots are usually highly unstable and jump statistically over the cathode surface. In a magnetic field parallel to the surface, preferably they move in the retrograde direction; i.e., opposite to the Lorentzian rule. If the field is inclined with respect to the surface, the spots drift away at a certain angle with respect to the proper retrograde direction (Robson drift motion). These well-known phenomena are explained by one stability theory

  7. Effects of radiotransmitter necklaces on behaviors of adult male western burrowing owls

    Science.gov (United States)

    Chipman, E.D.; McIntyre, N.E.; Ray, J.D.; Wallace, M.C.; Boal, C.W.

    2007-01-01

    We studied the behavioral effects of necklace-style radiotransmitters on breeding male western burrowing owls (Athene cunicularia hypugaea) in 2 areas of northwestern Texas, USA, in 2004 and 2005. We tested the hypothesis that transmittered owls would spend time interacting with their necklaces and as a result spend less time in vigilance and resting activities than would nontransmittered owls. Nontransmittered owls (n = 6) spent significantly more time being vigilant (P = 0.007) than did transmittered owls (n = 3) in 2004, who spent significant amounts of time interacting with their necklaces. In 2005, behaviors of transmittered owls (n = 8) were significantly different (P < 0.001) from control individuals (n = 4), but behaviors did not vary consistently by treatment period (prenecklace vs. necklace vs. postnecklace periods). Behavioral activity budgets varied considerably among individuals. Although the owls spent a significant amount of time interacting with their necklaces, they appeared to habituate to the presence of the transmitters within a relatively short period (<1 week), and necklaces did not affect survivorship or fitness in the short-term.

  8. Exploiting Semantic Web Technologies to Develop OWL-Based Clinical Practice Guideline Execution Engines.

    Science.gov (United States)

    Jafarpour, Borna; Abidi, Samina Raza; Abidi, Syed Sibte Raza

    2016-01-01

    Computerizing paper-based CPG and then executing them can provide evidence-informed decision support to physicians at the point of care. Semantic web technologies especially web ontology language (OWL) ontologies have been profusely used to represent computerized CPG. Using semantic web reasoning capabilities to execute OWL-based computerized CPG unties them from a specific custom-built CPG execution engine and increases their shareability as any OWL reasoner and triple store can be utilized for CPG execution. However, existing semantic web reasoning-based CPG execution engines suffer from lack of ability to execute CPG with high levels of expressivity, high cognitive load of computerization of paper-based CPG and updating their computerized versions. In order to address these limitations, we have developed three CPG execution engines based on OWL 1 DL, OWL 2 DL and OWL 2 DL + semantic web rule language (SWRL). OWL 1 DL serves as the base execution engine capable of executing a wide range of CPG constructs, however for executing highly complex CPG the OWL 2 DL and OWL 2 DL + SWRL offer additional executional capabilities. We evaluated the technical performance and medical correctness of our execution engines using a range of CPG. Technical evaluations show the efficiency of our CPG execution engines in terms of CPU time and validity of the generated recommendation in comparison to existing CPG execution engines. Medical evaluations by domain experts show the validity of the CPG-mediated therapy plans in terms of relevance, safety, and ordering for a wide range of patient scenarios.

  9. Spatial behaviour of little owls (Athene noctua) in a declining low-density population in Denmark

    DEFF Research Database (Denmark)

    Sunde, Peter; Thorup, Kasper; Jacobsen, Lars Bo

    2009-01-01

    Knowledge of a species' spatial behaviour is essential for understanding its behavioural ecology and a prerequisite to planning of conservation strategies. The little owl has shown a substantial decline in North-western Europe and is on the road of extinction in Denmark. To quantify relevant...... aspects of spatial behaviour in the last remaining Danish population, we followed 27 radio-tagged owls representing 14 territories during a period of 2 years. Mated owls were resident at nesting sites year-round with half of all nocturnal locations found within 125 m. Nightly distance from roosts peaked...

  10. A novel word spotting method based on recurrent neural networks.

    Science.gov (United States)

    Frinken, Volkmar; Fischer, Andreas; Manmatha, R; Bunke, Horst

    2012-02-01

    Keyword spotting refers to the process of retrieving all instances of a given keyword from a document. In the present paper, a novel keyword spotting method for handwritten documents is described. It is derived from a neural network-based system for unconstrained handwriting recognition. As such it performs template-free spotting, i.e., it is not necessary for a keyword to appear in the training set. The keyword spotting is done using a modification of the CTC Token Passing algorithm in conjunction with a recurrent neural network. We demonstrate that the proposed systems outperform not only a classical dynamic time warping-based approach but also a modern keyword spotting system, based on hidden Markov models. Furthermore, we analyze the performance of the underlying neural networks when using them in a recognition task followed by keyword spotting on the produced transcription. We point out the advantages of keyword spotting when compared to classic text line recognition.

  11. Modeling methods for GenCo bidding strategy optimization in the liberalized electricity spot market-A state-of-the-art review

    International Nuclear Information System (INIS)

    Li, Gong; Shi, Jing; Qu, Xiuli

    2011-01-01

    The electricity market has since 1980s been gradually evolving from a monopoly market into a liberalized one for encouraging competition and improving efficiency. This brings the opportunity for generation companies (GenCos) to make more profits while embracing more risks of not being dispatched. Therefore, it has become a core interest for the GenCos to develop optimal bidding strategies to maximize the profits and minimize the risks while participating in such a competitive market. The literature pertaining to this issue has grown rapidly in recent years, and many different modeling approaches, such as mathematical programming, game theory, and agent-based models, have been investigated under the liberalized market environment. Meanwhile, along with the increasing penetration of renewable energy, the electricity market is facing more complexity and stochasticity from both uncertain generation and dynamic demands. The intermittent and unsteady nature of these renewable power sources motivates the GenCos to further optimize their bidding strategy by considering the new constraints. This paper presents a comprehensive literature analysis on the state-of-the-art research of bidding strategy modeling methods. -- Highlights: → Publications on bidding in electricity spot markets are comprehensively reviewed. → Insights on the evolution of solution methodologies of recent 10 years are provided. → The pros and cons of these solution approaches are also discussed. → Future research directions, with renewable energy participations, are pointed out.

  12. Demographic data on the Little Owl (Athene noctua in Upper-Kiskunság (Hungary

    Directory of Open Access Journals (Sweden)

    Hámori Dániel

    2017-12-01

    Full Text Available This study focused on the clutch size and age-specific apparent survival rate of the Little Owl (Athene noctua population in Upper-Kiskunság, Hungary. Between May 2005 and April 2017, 640 individuals were captured and ringed in a total of 746 capture-recapture occasions. Artificial nest boxes were installed in the study area, breeding birds and pulli were captured for ringing/recaptured in these boxes (from March to May, or at the close neighbourhood of those (max. 168 m. Jolly-Seber’s open population method was applied to model the survival rate. The candidate model set included models incorporating age, year-effect, and the combination of those. AICc value was used to compare models in a selection approach. The final model was constructed via model averaging based on the models with significant explanatory power. The average number and SD of pullus/breeding pair was 3.78 ± 0.76. The average apparent annual survival rate (which does not differentiate between mortality and permanent emigration for the period between pullus stage and the time of the first breeding was estimated as 9.47% ± 2.99% SE, whereas the annual survival rate of adults was 82.74% ± 8.46% SE. The effect of sex on the survival rate of adults was not investigated due to female-biased sample, as the probability of capturing females is significantly higher in late spring months. Our experience reveals that during February and March it is possible to capture both sexes in the nest boxes, and it does not influence negatively the breeding success. Based on our results, the population of the Little Owl is stable in Upper-Kiskunság. A slight increase in estimated population size is observable even if we make no difference between mortality and permanent emigration. The high occupancy rate of the installed nest boxes reveals that nest site availability is an important limiting factor in the studied population.

  13. Influence of vegetation on the nocturnal foraging behaviors and vertebrate prey capture by endangered Burrowing Owls

    Directory of Open Access Journals (Sweden)

    Alan Marsh

    2014-06-01

    Full Text Available Restrictions in technology have limited past habitat selection studies for many species to the home-range level, as a finer-scale understanding was often not possible. Consequently, these studies may not identify the true mechanism driving habitat selection patterns, which may influence how such results are applied in conservation. We used GPS dataloggers with digital video recorders to identify foraging modes and locations in which endangered Burrowing Owls (Athene cunicularia captured prey. We measured the coarse and fine-scale characteristics of vegetation at locations in which owls searched for, versus where they caught, vertebrate prey. Most prey items were caught using hover-hunting. Burrowing Owls searched for, and caught, vertebrate prey in all cover types, but were more likely to kill prey in areas with sparse and less dense vegetative cover. Management strategies designed to increase Burrowing Owl foraging success in the Canadian prairies should try to ensure a mosaic of vegetation heights across cover types.

  14. Exposure affects the risk of an owl being mobbed - experimental evidence

    DEFF Research Database (Denmark)

    Hendrichsen, Ditte Katrine; Christiansen, Peter; Nielsen, Elsemarie K.

    2006-01-01

    Mobbing is a widespread anti-predator strategy in birds, and predators are generally expected to avoid mobbing. For example, observational studies suggest that the cryptic roosting behaviour of nocturnal predators, such as many owls, may be a strategy to limit mobbing. In this paper, we present...... the results of the first experimental study investigating to what degree roost exposure influences the risk of being mobbed, and the intensity of a mobbing incidence once initiated. To determine these factors, we used an experimental setup with taxidermic mounts of tawny owls Strix aluco in Grib Skov forest......, Denmark. The risk of an owl being mobbed during a 50 min morning survey period increased with the exposure of its roosting position, from 24% when hidden to 85% when openly exposed. The corresponding increase in the afternoon was from 6% to 36%. This suggests that an owl may minimize the mobbing rate...

  15. Breeding-season food habits of burrowing owls (Athene cunicularia) in southwestern Dominican Republic

    Science.gov (United States)

    Wiley, J.W.

    1998-01-01

    Diet data from 20 Burrowing Owl (Athene cunicularia) nests were collected in southwestern Dominican Republic in 1976, 1982, and 1996. Invertebrates (53.3%) comprised the most numerous prey items (N = 396) delivered to nests by adult owls, but vertebrates (46.7%) were much better represented than in other studies of Burrowing Owl diet. Among vertebrates, birds (28.3% of all items) and reptiles (14.9%) were most important, whereas mammals (1.0%) and amphibians (2.5%) were less commonly delivered to nests. Vertebrates, however, comprised more than twice (69.2%) of the total biomass as invertebrates (30.8%), with birds (50.4%) and reptiles (12.8%) the most important of the vertebrate prey classes. A positive relationship was observed between bird species abundance and number of individuals taken as prey by Burrowing Owls.

  16. Improvement of directionality and sound-localization by internal ear coupling in barn owls

    DEFF Research Database (Denmark)

    Wagner, Hermann; Christensen-Dalsgaard, Jakob; Kettler, Lutz

    Mark Konishi was one of the first to quantify sound-localization capabilities in barn owls. He showed that frequencies between 3 and 10 kHz underlie precise sound localization in these birds, and that they derive spatial information from processing interaural time and interaural level differences....... However, despite intensive research during the last 40 years it is still unclear whether and how internal ear coupling contributes to sound localization in the barn owl. Here we investigated ear directionality in anesthetized birds with the help of laser vibrometry. Care was taken that anesthesia...... time difference in the low-frequency range, barn owls hesitate to approach prey or turn their heads when only low-frequency auditory information is present in a stimulus they receive. Thus, the barn-owl's sound localization system seems to be adapted to work best in frequency ranges where interaural...

  17. Barred Owl Habitat and Prey: A Review and Synthesis of the Literature

    OpenAIRE

    Livezey, Kent B.

    2007-01-01

    Barred Owls (Strix varia) historically inhabited the forests of eastern North America. During the last century, they expanded their range to include forests throughout the southern provinces of Canada, southeastern Alaska, British Columbia, Washington, Oregon, and northern California. To date, there has been no synthesis of the varied habitats or prey used by Barred Owls in their expanded range. Here I review and synthesize studies concerning habitat (N  =  114) and prey (N  =  43) of Barred ...

  18. Optical Waveguide Lightmode Spectroscopy (OWLS) as a Sensor for Thin Film and Quantum Dot Corrosion

    OpenAIRE

    Yu, Hao; Eggleston, Carrick M.; Chen, Jiajun; Wang, Wenyong; Dai, Qilin; Tang, Jinke

    2012-01-01

    Optical waveguide lightmode spectroscopy (OWLS) is usually applied as a biosensor system to the sorption-desorption of proteins to waveguide surfaces. Here, we show that OWLS can be used to monitor the quality of oxide thin film materials and of coatings of pulsed laser deposition synthesized CdSe quantum dots (QDs) intended for solar energy applications. In addition to changes in data treatment and experimental procedure, oxide- or QD-coated waveguide sensors must be synthesized. We synthesi...

  19. Modelling spatial concordance between Rocky Mountain spotted fever disease incidence and habitat probability of its vector Dermacentor variabilis (American dog tick).

    Science.gov (United States)

    Atkinson, Samuel F; Sarkar, Sahotra; Aviña, Aldo; Schuermann, Jim A; Williamson, Phillip

    2012-11-01

    The spatial distribution of Dermacentor variabilis, the most commonly identified vector of the bacterium Rickettsia rickettsii which causes Rocky Mountain spotted fever (RMSF) in humans, and the spatial distribution of RMSF, have not been previously studied in the south central United States of America, particularly in Texas. From an epidemiological perspective, one would tend to hypothesise that there would be a high degree of spatial concordance between the habitat suitability for the tick and the incidence of the disease. Both maximum-entropy modelling of the tick's habitat suitability and spatially adaptive filters modelling of the human incidence of RMSF disease provide reliable portrayals of the spatial distributions of these phenomenons. Even though rates of human cases of RMSF in Texas and rates of Dermacentor ticks infected with Rickettsia bacteria are both relatively low in Texas, the best data currently available allows a preliminary indication that the assumption of high levels of spatial concordance would not be correct in Texas (Kappa coefficient of agreement = 0.17). It will take substantially more data to provide conclusive findings, and to understand the results reported here, but this study provides an approach to begin understanding the discrepancy.

  20. Modelling spatial concordance between Rocky Mountain spotted fever disease incidence and habitat probability of its vector Dermacentor variabilis (American dog tick

    Directory of Open Access Journals (Sweden)

    Samuel F. Atkinson

    2012-11-01

    Full Text Available The spatial distribution of Dermacentor variabilis, the most commonly identified vector of the bacterium Rickettsia rickettsii which causes Rocky Mountain spotted fever (RMSF in humans, and the spatial distribution of RMSF, have not been previously studied in the south central United States of America, particularly in Texas. From an epidemiological perspective, one would tend to hypothesise that there would be a high degree of spatial concordance between the habitat suitability for the tick and the incidence of the disease. Both maximum-entropy modelling of the tick’s habitat suitability and spatially adaptive filters modelling of the human incidence of RMSF disease provide reliable portrayals of the spatial distributions of these phenomenons. Even though rates of human cases of RMSF in Texas and rates of Dermacentor ticks infected with Rickettsia bacteria are both relatively low in Texas, the best data currently available allows a preliminary indication that the assumption of high levels of spatial concordance would not be correct in Texas (Kappa coefficient of agreement = 0.17. It will take substantially more data to provide conclusive findings, and to understand the results reported here, but this study provides an approach to begin understanding the discrepancy.

  1. The effect of hot spots upon swelling of Zircaloy cladding as modelled by the code CANSWEL-2

    International Nuclear Information System (INIS)

    Haste, T.J.; Gittus, J.H.

    1980-12-01

    The code CANSWEL-2 models cladding creep deformation under conditions relevant to a loss-of-coolant accident (LOCA) in a pressurised-water reactor (PWR). It can treat azimuthal non-uniformities in cladding thickness and temperature, and model the mechanical restraint imposed by the nearest neighbouring rods, including situations where cladding is forced into non-circular shapes. The physical and mechanical models used in the code are presented. Applications of the code are described, both as a stand-alone version and as part of the PWR LOCA code MABEL-2. Comparison with a limited number of relevant out-of-reactor creep strain experiments has generally shown encouraging agreement with the data. (author)

  2. Unblinding the dark matter blind spots

    International Nuclear Information System (INIS)

    Han, Tao; Kling, Felix

    2017-01-01

    The dark matter (DM) blind spots in the Minimal Supersymmetric Standard Model (MSSM) refer to the parameter regions where the couplings of the DM particles to the Z-boson or the Higgs boson are almost zero, leading to vanishingly small signals for the DM direct detections. In this paper, we carry out comprehensive analyses for the DM searches under the blind-spot scenarios in MSSM. Guided by the requirement of acceptable DM relic abundance, we explore the complementary coverage for the theory parameters at the LHC, the projection for the future underground DM direct searches, and the indirect searches from the relic DM annihilation into photons and neutrinos. We find that (i) the spin-independent (SI) blind spots may be rescued by the spin-dependent (SD) direct detection in the future underground experiments, and possibly by the indirect DM detections from IceCube and SuperK neutrino experiments; (ii) the detection of gamma rays from Fermi-LAT may not reach the desirable sensitivity for searching for the DM blind-spot regions; (iii) the SUSY searches at the LHC will substantially extend the discovery region for the blind-spot parameters. As a result, the dark matter blind spots thus may be unblinded with the collective efforts in future DM searches.

  3. Sweet Spot Supersymmetry and Composite Messengers

    International Nuclear Information System (INIS)

    Ibe, Masahiro; Kitano, Ryuichiro

    2007-01-01

    Sweet spot supersymmetry is a phenomenologically and cosmologically perfect framework to realize a supersymmetric world at short distance. We discuss a class of dynamical models of supersymmetry breaking and its mediation whose low-energy effective description falls into this framework. Hadron fields in the dynamical models play a role of the messengers of the supersymmetry breaking. As is always true in the models of the sweet spot supersymmetry, the messenger scale is predicted to be 10 5 GeV ∼ mess ∼ 10 GeV. Various values of the effective number of messenger fields N mess are possible depending on the choice of the gauge group

  4. In-pile loop OWL-2 and irradiation tests done with it

    International Nuclear Information System (INIS)

    Suzuki, Shinobu; Ikeshima, Yoshiaki; Kawano, Masakatsu; Watanabe, Hiroyuki; Sato, Hitoshi; Tanaka, Isao

    1990-11-01

    The OWL-2 which was built in the JMTR as the biggest water loop in Japan has been operating for irradiation service since February 1972. The desired objective of the OWL-2, contributing to the development of various nuclear fuels and materials for the light water power reactor and to reactor engineering, has been so fully achieved that the OWL-2 is planned to be dismantled. After the dismantling, a loop, needed for the research and development of the breeding blanket for the fusion reactor, is going to be installed in place of the OWL-2 as a part of the JMTR Modification Program. This paper deals with the history of the OWL-2 with an emphasis on the technical affairs taken into consideration when designing the OWL-2, the irradiation tests, development of the turbine flowmeter, results of the surveillance test of the material of the in-reactor tube, the knowledge gained in the course of the investigation into the cause of transgranular stress corrosion cracking (TGSCC) which developed in the wall of the in-reactor tube, and countermeasures taken to prevent TGSCC from recurring. (author)

  5. Examining Atmospheric and Ecological Drivers of Wildfires, Modeling Wildfire Occurrence in the Southwest United States, and Using Atmospheric Sounding Observations to Verify National Weather Service Spot Forecasts

    Science.gov (United States)

    Nauslar, Nicholas J.

    This dissertation is comprised of three different papers that all pertain to wildland fire applications. The first paper performs a verification analysis on mixing height, transport winds, and Haines Index from National Weather Service spot forecasts across the United States. The final two papers, which are closely related, examine atmospheric and ecological drivers of wildfire for the Southwest Area (SWA) (Arizona, New Mexico, west Texas, and Oklahoma panhandle) to better equip operational fire meteorologists and managers to make informed decisions on wildfire potential in this region. The verification analysis here utilizes NWS spot forecasts of mixing height, transport winds and Haines Index from 2009-2013 issued for a location within 50 km of an upper sounding location and valid for the day of the fire event. Mixing height was calculated from the 0000 UTC sounding via the Stull, Holzworth, and Richardson methods. Transport wind speeds were determined by averaging the wind speed through the boundary layer as determined by the three mixing height methods from the 0000 UTC sounding. Haines Index was calculated at low, mid, and high elevation based on the elevation of the sounding and spot forecast locations. Mixing height forecasts exhibited large mean absolute errors and biased towards over forecasting. Forecasts of transport wind speeds and Haines Index outperformed mixing height forecasts with smaller errors relative to their respective means. The rainfall and lightning associated with the North American Monsoon (NAM) can vary greatly intra- and inter-annually and has a large impact on wildfire activity across the SWA by igniting or suppressing wildfires. NAM onset thresholds and subsequent dates are determined for the SWA and each Predictive Service Area (PSA), which are sub-regions used by operational fire meteorologists to predict wildfire potential within the SWA, April through September from 1995-2013. Various wildfire activity thresholds using the number

  6. Neighborhood and habitat effects on vital rates: expansion of the Barred Owl in the Oregon Coast Ranges

    Science.gov (United States)

    Yackulic, Charles B.; Reid, Janice; Davis, Raymond; Hines, James E.; Nichols, James D.; Forsman, Eric

    2012-01-01

    In this paper, we modify dynamic occupancy models developed for detection-nondetection data to allow for the dependence of local vital rates on neighborhood occupancy, where neighborhood is defined very flexibly. Such dependence of occupancy dynamics on the status of a relevant neighborhood is pervasive, yet frequently ignored. Our framework permits joint inference about the importance of neighborhood effects and habitat covariates in determining colonization and extinction rates. Our specific motivation is the recent expansion of the Barred Owl (Strix varia) in western Oregon, USA, over the period 1990-2010. Because the focal period was one of dramatic range expansion and local population increase, the use of models that incorporate regional occupancy (sources of colonists) as determinants of dynamic rate parameters is especially appropriate. We began our analysis of 21 years of Barred Owl presence/nondetection data in the Tyee Density Study Area (TDSA) by testing a suite of six models that varied only in the covariates included in the modeling of detection probability. We then tested whether models that used regional occupancy as a covariate for colonization and extinction outperformed models with constant or year-specific colonization or extinction rates. Finally we tested whether habitat covariates improved the AIC of our models, focusing on which habitat covariates performed best, and whether the signs of habitat effects are consistent with a priori hypotheses. We conclude that all covariates used to model detection probability lead to improved AIC, that regional occupancy influences colonization and extinction rates, and that habitat plays an important role in determining extinction and colonization rates. As occupancy increases from low levels toward equilibrium, colonization increases and extinction decreases, presumably because there are more and more dispersing juveniles. While both rates are affected, colonization increases more than extinction decreases

  7. Spatiotemporal chaos of self-replicating spots in reaction-diffusion systems.

    Science.gov (United States)

    Wang, Hongli; Ouyang, Qi

    2007-11-23

    The statistical properties of self-replicating spots in the reaction-diffusion Gray-Scott model are analyzed. In the chaotic regime of the system, the spots that dominate the spatiotemporal chaos grow and divide in two or decay into the background randomly and continuously. The rates at which the spots are created and decay are observed to be linearly dependent on the number of spots in the system. We derive a probabilistic description of the spot dynamics based on the statistical independence of spots and thus propose a characterization of the spatiotemporal chaos dominated by replicating spots.

  8. Occurrence of the saw-whet owl in Florida

    Science.gov (United States)

    Lesser, F.H.; Stickley, A.R.

    1967-01-01

    On 31 October 1965 at 1000 hours we observed and collected a Saw-whet Owl (Aegolius acadicus) in adult plumage and in apparently good physical condition at Ponte Vedra, St. Johns County, Florida. The bird flew from beneath a truck to a cross beam in a garage adjoining a large, fresh-water, wooded swamp dominated by cabbage palms (Sabal palmetto). We found a regurgitated pellet and a freshly killed, partially eaten cotton mouse (Peromyscus gossypinus) beneath the truck. The bird was sent to Henry M. Stevenson for deposit in Florida State University Museum, Tallahassee (specimen no. 4092b). Dr. Stevenson found that the skull had been shattered and the gonads destroyed in collecting. Total length (before skinning) was 210 mm.

  9. Dyscoria associated with herpesvirus infection in owl monkeys (Aotus nancymae)

    Energy Technology Data Exchange (ETDEWEB)

    Gozalo, Alfonso S.; Montoya, Enrique J.; Weller, Richard E.

    2008-08-16

    Abstract Dyscoria was observed in a female owl monkey and her two offspring. A third offspring was found dead with necrohemorrhagic encephalitis. Two males paired with the female died, one of which showed oral ulcers at necropsy. Histologic examination of the oral ulcers revealed syncytia and eosinophilic intranuclear inclusion bodies in epithelial cells. Ocular examination revealed posterior synechia associated with the dyscoria in all three animals. Serum samples from the female and her offspring were positive for Herpesvirus simplex antibodies by enzyme-linked immunosorbent assay. The clinical history, gross and microscopic lesions, and serology results suggests a herpesviral etiology, possibly, H. simplex or H. saimiri-1. This report underscores the risks associated with introducing animals into breeding or research colonies that were previously kept as pets or those from unknown origin that could carry asymptomatic pathogenic Herpesvirus infections. In addition, herpesviral infection should be considered among the differential diagnoses if dyscoria is observed in nonhuman primates.

  10. An analysis of Apulian micromammal populations by studying owl's pellets

    Directory of Open Access Journals (Sweden)

    Michele Bux

    2000-09-01

    Full Text Available Abstract The study contains data from 3302 preys found in Barn owl pellets from 15 sites within the Provinces of Foggia and Bari (Apulia, Southern Italy. Eleven micromammal species were identified. Microtus savii and Apodemus sylvaticus were the most frequents preys. No specimen of Clethrionomys glareolus and Apodemus flavicollis were found which is probably due to the habitat typology examined (all thermoxerophilous phytocoenosis. The Sorensen Index showed a high faunistic affinity among all the sites studied and other localities of Apulia. However, by applying the index of biocenotic differences (Renkonen a difference in some localities, in relation to Microtus savii and Insectivores abundance, was found.

  11. The fractal nature of vacuum arc cathode spots

    International Nuclear Information System (INIS)

    Anders, Andre

    2005-01-01

    Cathode spot phenomena show many features of fractals, for example self-similar patterns in the emitted light and arc erosion traces. Although there have been hints on the fractal nature of cathode spots in the literature, the fractal approach to spot interpretation is underutilized. In this work, a brief review of spot properties is given, touching the differences between spot type 1 (on cathodes surfaces with dielectric layers) and spot type 2 (on metallic, clean surfaces) as well as the known spot fragment or cell structure. The basic properties of self-similarity, power laws, random colored noise, and fractals are introduced. Several points of evidence for the fractal nature of spots are provided. Specifically power laws are identified as signature of fractal properties, such as spectral power of noisy arc parameters (ion current, arc voltage, etc) obtained by fast Fourier transform. It is shown that fractal properties can be observed down to the cutoff by measurement resolution or occurrence of elementary steps in physical processes. Random walk models of cathode spot motion are well established: they go asymptotically to Brownian motion for infinitesimal step width. The power spectrum of the arc voltage noise falls as 1/f 2 , where f is frequency, supporting a fractal spot model associated with Brownian motion

  12. Hot Spot Temperature and Grey Target Theory-Based Dynamic Modelling for Reliability Assessment of Transformer Oil-Paper Insulation Systems: A Practical Case Study

    Directory of Open Access Journals (Sweden)

    Lefeng Cheng

    2018-01-01

    Full Text Available This paper develops a novel dynamic correction method for the reliability assessment of large oil-immersed power transformers. First, with the transformer oil-paper insulation system (TOPIS as the target of evaluation and the winding hot spot temperature (HST as the core point, an HST-based static ageing failure model is built according to the Weibull distribution and Arrhenius reaction law, in order to describe the transformer ageing process and calculate the winding HST for obtaining the failure rate and life expectancy of TOPIS. A grey target theory based dynamic correction model is then developed, combined with the data of Dissolved Gas Analysis (DGA in power transformer oil, in order to dynamically modify the life expectancy calculated by the built static model, such that the corresponding relationship between the state grade and life expectancy correction coefficient of TOPIS can be built. Furthermore, the life expectancy loss recovery factor is introduced to correct the life expectancy of TOPIS again. Lastly, a practical case study of an operating transformer has been undertaken, in which the failure rate curve after introducing dynamic corrections can be obtained for the reliability assessment of this transformer. The curve shows a better ability of tracking the actual reliability level of transformer, thus verifying the validity of the proposed method and providing a new way for transformer reliability assessment. This contribution presents a novel model for the reliability assessment of TOPIS, in which the DGA data, as a source of information for the dynamic correction, is processed based on the grey target theory, thus the internal faults of power transformer can be diagnosed accurately as well as its life expectancy updated in time, ensuring that the dynamic assessment values can commendably track and reflect the actual operation state of the power transformers.

  13. Non-dimensional characterization of the friction stir/spot welding process using a simple Couette flow model part I: Constant property Bingham plastic solution

    International Nuclear Information System (INIS)

    Buck, Gregory A.; Langerman, Michael

    2004-01-01

    A simplified model for the material flow created during a friction stir/spot welding process has been developed using a boundary driven cylindrical Couette flow model with a specified heat flux at the inner cylinder for a Bingham plastic material. Non-dimensionalization of the constant property governing equations identified three parameters that influence the velocity and temperature fields. Analytic solutions to these equations are presented and some representative results from a parametric study (parameters chosen and varied over ranges expected for the welding of a wide variety of metals) are discussed. The results also provide an expression for the critical radius (location of vanishing material velocity) as functions of the relevant non-dimensional parameters. A final study was conducted in which values for the non-dimensional heat flux parameter were chosen to produce peak dimensional temperatures on the order of 80% of the melting temperature for a typical 2000 series aluminum. Under these conditions it was discovered that the ratio of the maximum rate of shear work within the material (viscous dissipation) to the rate of energy input at the boundary due to frictional heating, ranged from about 0.0005% for the lowest pin tool rotation rate, to about 1.3% for the highest tool rotation rate studied. Curve fits to previous Gleeble data taken for a number of aluminum alloys provide reasonable justification for the Bingham plastic constitutive model, and although these fits indicate a strong temperature dependence for critical flow stress and viscosity, this work provides a simple tool for more sophisticated model validation. Part II of this study will present numerical solutions for velocity and temperature fields resulting from the non-linear coupling of the momentum and energy equations created by temperature dependent transport properties

  14. TV spots' impact.

    Science.gov (United States)

    El-bakly, S

    1994-09-01

    The Information, Education and Communication (IEC) Center of the State Information Service was established in 1979 for the purpose of providing information to the people on the population issue. The Ministry of Information has accorded the State Information Service free TV and radio air time for family planning dramas and spots. In the early years information campaigns were organized to make people aware of the population problem by slogans, songs, and cartoons. Around 1984 misconceptions about family planning and contraceptives were attacked through a number of TV and radio spots. A few years later 21 spots on specific contraceptive methods were broadcast which were aired for three years over 3000 times. They were extremely successful. The impact of these TV spots was one of the major reasons why the contraceptive prevalence rate increased from 30% in 1984 to 38% in 1988 and 47% in 1992. Spots were also broadcast about the social implications of large families. The TV soap opera "And The Nile Flows On", with the family planning message interwoven into it, was very well received by the target audience. A program entitled "Wedding of the Month" features couples who know family planning well. The most successful radio program is a 15-20 minute long quiz show for residents of the villages where the Select Villages Project is being implemented. The State Information Service has 60 local information centers in the 26 governorates of Egypt that make plans for the family planning campaign. In 1992 the Minya Initiative, a family planning project was implemented in the Minya Governorate. As a result, the contraceptive prevalence rate rose from 22% to 30% over 18 months. A new project, the Select Village Project, was developed in 1993 that replicates the Minya Initiative on the village level in other governorates. This new project that was implemented in sixteen governorates.

  15. To dare or not to dare? Risk management by owls in a predator-prey foraging game.

    Science.gov (United States)

    Embar, Keren; Raveh, Ashael; Burns, Darren; Kotler, Burt P

    2014-07-01

    In a foraging game, predators must catch elusive prey while avoiding injury. Predators manage their hunting success with behavioral tools such as habitat selection, time allocation, and perhaps daring-the willingness to risk injury to increase hunting success. A predator's level of daring should be state dependent: the hungrier it is, the more it should be willing to risk injury to better capture prey. We ask, in a foraging game, will a hungry predator be more willing to risk injury while hunting? We performed an experiment in an outdoor vivarium in which barn owls (Tyto alba) were allowed to hunt Allenby's gerbils (Gerbillus andersoni allenbyi) from a choice of safe and risky patches. Owls were either well fed or hungry, representing the high and low state, respectively. We quantified the owls' patch use behavior. We predicted that hungry owls would be more daring and allocate more time to the risky patches. Owls preferred to hunt in the safe patches. This indicates that owls manage risk of injury by avoiding the risky patches. Hungry owls doubled their attacks on gerbils, but directed the added effort mostly toward the safe patch and the safer, open areas in the risky patch. Thus, owls dared by performing a risky action-the attack maneuver-more times, but only in the safest places-the open areas. We conclude that daring can be used to manage risk of injury and owls implement it strategically, in ways we did not foresee, to minimize risk of injury while maximizing hunting success.

  16. Integrating sustainable hunting in biodiversity protection in Central Africa: hot spots, weak spots, and strong spots.

    Directory of Open Access Journals (Sweden)

    John E Fa

    Full Text Available Wild animals are a primary source of protein (bushmeat for people living in or near tropical forests. Ideally, the effect of bushmeat harvests should be monitored closely by making regular estimates of offtake rate and size of stock available for exploitation. However, in practice, this is possible in very few situations because it requires both of these aspects to be readily measurable, and even in the best case, entails very considerable time and effort. As alternative, in this study, we use high-resolution, environmental favorability models for terrestrial mammals (N = 165 in Central Africa to map areas of high species richness (hot spots and hunting susceptibility. Favorability models distinguish localities with environmental conditions that favor the species' existence from those with detrimental characteristics for its presence. We develop an index for assessing Potential Hunting Sustainability (PHS of each species based on their ecological characteristics (population density, habitat breadth, rarity and vulnerability, weighted according to restrictive and permissive assumptions of how species' characteristics are combined. Species are classified into five main hunting sustainability classes using fuzzy logic. Using the accumulated favorability values of all species, and their PHS values, we finally identify weak spots, defined as high diversity regions of especial hunting vulnerability for wildlife, as well as strong spots, defined as high diversity areas of high hunting sustainability potential. Our study uses relatively simple models that employ easily obtainable data of a species' ecological characteristics to assess the impacts of hunting in tropical regions. It provides information for management by charting the geography of where species are more or less likely to be at risk of extinction from hunting.

  17. SPOTTED STAR LIGHT CURVES WITH ENHANCED PRECISION

    International Nuclear Information System (INIS)

    Wilson, R. E.

    2012-01-01

    The nearly continuous timewise coverage of recent photometric surveys is free of the large gaps that compromise attempts to follow starspot growth and decay as well as motions, thereby giving incentive to improve computational precision for modeled spots. Due to the wide variety of star systems in the surveys, such improvement should apply to light/velocity curve models that accurately include all the main phenomena of close binaries and rotating single stars. The vector fractional area (VFA) algorithm that is introduced here represents surface elements by small sets of position vectors so as to allow accurate computation of circle-triangle overlap by spherical geometry. When computed by VFA, spots introduce essentially no noticeable scatter in light curves at the level of one part in 10,000. VFA has been put into the Wilson-Devinney light/velocity curve program and all logic and mathematics are given so as to facilitate entry into other such programs. Advantages of precise spot computation include improved statistics of spot motions and aging, reduced computation time (intrinsic precision relaxes needs for grid fineness), noise-free illustration of spot effects in figures, and help in guarding against false positives in exoplanet searches, where spots could approximately mimic transiting planets in unusual circumstances. A simple spot growth and decay template quantifies time profiles, and specifics of its utilization in differential corrections solutions are given. Computational strategies are discussed, the overall process is tested in simulations via solutions of synthetic light curve data, and essential simulation results are described. An efficient time smearing facility by Gaussian quadrature can deal with Kepler mission data that are in 30 minute time bins.

  18. Roth spots in pernicious anaemia

    OpenAIRE

    Macauley, Mavin; Nag, Satyajit

    2011-01-01

    Roth spots are white-centred retinal haemorrhages, previously thought to be pathognomonic for subacute bacterial endocarditis. A number of other conditions can be associated with Roth spots. In this case, the authors describe the association of Roth spots and pernicious anaemia. This association has been rarely described in the medical literature. Correct diagnosis and treatment with intramuscular vitamin B12 injections resulted in complete resolution of the anaemia and Roth spots. The author...

  19. Poisson Spot with Magnetic Levitation

    Science.gov (United States)

    Hoover, Matthew; Everhart, Michael; D'Arruda, Jose

    2010-01-01

    In this paper we describe a unique method for obtaining the famous Poisson spot without adding obstacles to the light path, which could interfere with the effect. A Poisson spot is the interference effect from parallel rays of light diffracting around a solid spherical object, creating a bright spot in the center of the shadow.

  20. Dystrophin Hot-Spot Mutants Leading to Becker Muscular Dystrophy Insert More Deeply into Membrane Models than the Native Protein.

    Science.gov (United States)

    Ameziane-Le Hir, Sarah; Paboeuf, Gilles; Tascon, Christophe; Hubert, Jean-François; Le Rumeur, Elisabeth; Vié, Véronique; Raguénès-Nicol, Céline

    2016-07-26

    Dystrophin (DYS) is a membrane skeleton protein whose mutations lead to lethal Duchenne muscular dystrophy or to the milder Becker muscular dystrophy (BMD). One third of BMD "in-frame" exon deletions are located in the region that codes for spectrin-like repeats R16 to R21. We focused on four prevalent mutated proteins deleted in this area (called RΔ45-47, RΔ45-48, RΔ45-49, and RΔ45-51 according to the deleted exon numbers), analyzing protein/membrane interactions. Two of the mutants, RΔ45-48 and RΔ45-51, led to mild pathologies and displayed a similar triple coiled-coil structure as the full-length DYS R16-21, whereas the two others, RΔ45-47 and RΔ45-49, induced more severe pathologies and showed "fractional" structures unrelated to the normal one. To explore lipid packing, small unilamellar liposomes (SUVs) and planar monolayers were used at various initial surface pressures. The dissociation constants determined by microscale thermophoresis (MST) were much higher for the full-length DYS R161-21 than for the mutants; thus the wild type protein has weaker SUV binding. Comparing surface pressures after protein adsorption and analysis of atomic force microscopy images of mixed protein/lipid monolayers revealed that the mutants insert more into the lipid monolayer than the wild type does. In fact, in both models every deletion mutant showed more interactions with membranes than the full-length protein did. This means that mutations in the R16-21 part of dystrophin disturb the protein's molecular behavior as it relates to membranes, regardless of whether the accompanying pathology is mild or severe.

  1. On the Spot: Oceans

    OpenAIRE

    Male, Alan; Butterfield, Moira

    2000-01-01

    This a children's non-fiction, knowledge bearing picture book that is part of a Reader's Digest series called 'On the Spot'. The series deals with a range of topics related to the natural world and this one introduces its young audience to the ecosystems of the oceans. \\ud The publication was illustrated and designed by the author (Alan Male) and is technically described as a board book with interactive 'pop up' features, specifically conceived to engage children's discovery and learning thro...

  2. El spot electoral negativo

    Directory of Open Access Journals (Sweden)

    Palma Peña-Jiménez

    2011-01-01

    Full Text Available l spot político tiene durante la campaña un objetivo final inequívoco: la consecución del voto favorable. Se dirige al cuerpo electoral a través de la televisión y de Internet, y presenta, en muchos casos, un planteamiento negativo, albergando mensajes destinados a la crítica frontal contra el adversario, más que a la exposición de propuestas propias. Este artículo se centra en el análisis del spot electoral negativo, en aquellas producciones audiovisuales construidas sin más causa que la reprobación del contrincante. Se trata de vídeos que, lejos de emplearse en difundir las potencialidades de la organización y las virtudes de su candidato –además de su programa electoral–, consumen su tiempo en descalificar al oponente mediante la transmisión de mensajes, muchas veces, ad hominem. Repasamos el planteamiento negativo del spot electoral desde su primera manifestación, que en España data de 1996, año de emisión del conocido como vídeo del dóberman, sin olvidar otros ejemplos que completan el objeto de estudio.

  3. Spot: A Programming Language for Verified Flight Software

    Science.gov (United States)

    Bocchino, Robert L., Jr.; Gamble, Edward; Gostelow, Kim P.; Some, Raphael R.

    2014-01-01

    The C programming language is widely used for programming space flight software and other safety-critical real time systems. C, however, is far from ideal for this purpose: as is well known, it is both low-level and unsafe. This paper describes Spot, a language derived from C for programming space flight systems. Spot aims to maintain compatibility with existing C code while improving the language and supporting verification with the SPIN model checker. The major features of Spot include actor-based concurrency, distributed state with message passing and transactional updates, and annotations for testing and verification. Spot also supports domain-specific annotations for managing spacecraft state, e.g., communicating telemetry information to the ground. We describe the motivation and design rationale for Spot, give an overview of the design, provide examples of Spot's capabilities, and discuss the current status of the implementation.

  4. Roth spots in pernicious anaemia.

    Science.gov (United States)

    Macauley, Mavin; Nag, Satyajit

    2011-04-19

    Roth spots are white-centred retinal haemorrhages, previously thought to be pathognomonic for subacute bacterial endocarditis. A number of other conditions can be associated with Roth spots. In this case, the authors describe the association of Roth spots and pernicious anaemia. This association has been rarely described in the medical literature. Correct diagnosis and treatment with intramuscular vitamin B(12) injections resulted in complete resolution of the anaemia and Roth spots. The authors hope to alert clinicians to think of various differentials of Roth spots, and initiate prompt investigation and management.

  5. Spot Weight Adaptation for Moving Target in Spot Scanning Proton Therapy.

    Science.gov (United States)

    Morel, Paul; Wu, Xiaodong; Blin, Guillaume; Vialette, Stéphane; Flynn, Ryan; Hyer, Daniel; Wang, Dongxu

    2015-01-01

    This study describes a real-time spot weight adaptation method in spot-scanning proton therapy for moving target or moving patient, so that the resultant dose distribution closely matches the planned dose distribution. The method proposed in this study adapts the weight (MU) of the delivering pencil beam to that of the target spot; it will actually hit during patient/target motion. The target spot that a certain delivering pencil beam may hit relies on patient monitoring and/or motion modeling using four-dimensional (4D) CT. After the adapted delivery, the required total weight [Monitor Unit (MU)] for this target spot is then subtracted from the planned value. With continuous patient motion and continuous spot scanning, the planned doses to all target spots will eventually be all fulfilled. In a proof-of-principle test, a lung case was presented with realistic temporal and motion parameters; the resultant dose distribution using spot weight adaptation was compared to that without using this method. The impact of the real-time patient/target position tracking or prediction was also investigated. For moderate motion (i.e., mean amplitude 0.5 cm), D95% to the planning target volume (PTV) was only 81.5% of the prescription (RX) dose; with spot weight adaptation PTV D95% achieves 97.7% RX. For large motion amplitude (i.e., 1.5 cm), without spot weight adaptation PTV D95% is only 42.9% of RX; with spot weight adaptation, PTV D95% achieves 97.7% RX. Larger errors in patient/target position tracking or prediction led to worse final target coverage; an error of 3 mm or smaller in patient/target position tracking is preferred. The proposed spot weight adaptation method was able to deliver the planned dose distribution and maintain target coverage when patient motion was involved. The successful implementation of this method would rely on accurate monitoring or prediction of patient/target motion.

  6. Spot Weight Adaptation for Moving Target in Spot Scanning Proton Therapy

    Directory of Open Access Journals (Sweden)

    Paul eMorel

    2015-05-01

    Full Text Available Purpose: This study describes a real-time spot weight adaptation method in spot-scanning proton therapy for moving target or moving patient, so that the resultant dose distribution closely matches the planned dose distribution. Materials and Methods: The method proposed in this study adapts the weight (MU of the delivering pencil beam to that of the target spot it will actually hit during patient/target motion. The target spot a certain delivering pencil beam may hit relies on patient monitoring and/or motion modeling using four-dimensional (4D CT. After the adapted delivery, the required total weight (MU for this target spot is then subtracted from the planned value. With continuous patient motion and continuous spot scanning, the planned doses to all target spots will eventually be all fulfilled. In a proof-of-principle test, a lung case was presented with realistic temporal and motion parameters; the resultant dose distribution using spot weight adaptation was compared to that without using this method. The impact of the real-time patient/target position tracking or prediction was also investigated.Results: For moderate motion (i.e., mean amplitude 0.5 cm, D95% to the planning target volume (PTV was only 81.5% of the prescription (RX dose; with spot weight adaptation PTV D95% achieves 97.7%RX. For large motion amplitude (i.e., 1.5 cm, without spot weight adaptation PTV D95% is only 42.9% of RX; with spot weight adaptation, PTV D95% achieves 97.7%RX. Larger errors in patient/target position tracking or prediction led to worse final target coverage; an error of 3mm or smaller in patient/target position tracking is preferred. Conclusion: The proposed spot weight adaptation method was able to deliver the planned dose distribution and maintain target coverage when patient motion was involved. The successful implementation of this method would rely on accurate monitoring or prediction of patient/target motion.

  7. Spatial, road geometric, and biotic factors associated with Barn Owl mortality along an interstate highway

    Science.gov (United States)

    Arnold, Erin M.; Hanser, Steven E.; Regan, Tempe; Thompson, Jeremy; Lowe, Melinda; Kociolek, Angela; Belthoff, James R.

    2018-01-01

    Highway programs typically focus on reducing vehicle collisions with large mammals because of economic or safety reasons while overlooking the millions of birds that die annually from traffic. We studied wildlife‐vehicle collisions along an interstate highway in southern Idaho, USA, with among the highest reported rates of American Barn Owl Tyto furcata road mortality. Carcass data from systematic and ad hoc surveys conducted in 2004–2006 and 2013–2015 were used to explore the extent to which spatial, road geometric, and biotic factors explained Barn Owl‐vehicle collisions. Barn Owls outnumbered all other identified vertebrate species of roadkill and represented > 25% of individuals and 73.6% of road‐killed birds. At a 1‐km highway segment scale, the number of dead Barn Owls decreased with increasing numbers of human structures, cumulative length of secondary roads near the highway, and width of the highway median. Number of dead Barn Owls increased with higher commercial average annual daily traffic (CAADT), small mammal abundance index, and with grass rather than shrubs in the roadside verge. The small mammal abundance index was also greater in roadsides with grass versus mixed shrubs, suggesting that Barn Owls may be attracted to grassy portions of the highway with more abundant small mammals for hunting prey. When assessed at a 3‐km highway segment scale, the number of dead Barn Owls again increased with higher CAADT as well as with greater numbers of dairy farms. At a 5‐km scale, number of dead Barn Owls increased with greater percentage of cropland near the highway. While human conversion of the environment from natural shrub‐steppe to irrigated agriculture in this region of Idaho has likely enhanced habitat for Barns Owls, it simultaneously has increased risk for owl‐vehicle collisions where an interstate highway traverses the altered landscape. We review some approaches for highway mitigation and suggest that reducing wildlife

  8. Molecular and histological characterization of age spots

    Science.gov (United States)

    Choi, Wonseon; Yin, Lanlan; Smuda, Christoph; Batzer, Jan; Hearing, Vincent J.; Kolbe, Ludger

    2016-01-01

    Age spots, also called solar lentigines and lentigo senilis, are light brown to black pigmented lesions of various sizes that typically develop in chronically sun-exposed skin. It is well known that age spots are strongly related to chronic sun exposure and are associated with photodamage and an increased risk for skin cancer, however, the mechanism(s) underlying their development remain poorly understood. We used immunohistochemical analysis and microarray analysis to investigate the processes involved in their formation, focusing on specific markers associated with the functions and proliferation of melanocytes and keratinocytes. A total of 193 genes were differentially expressed in age spots but melanocyte pigment genes were not among them. The increased expression of keratins 5 and 10, markers of basal and suprabasal keratinocytes, respectively, in age spots suggests that the increased proliferation of basal keratinocytes combined with the decreased turnover of suprabasal keratinocytes leads to the exaggerated formation of rete ridges in lesional epidermis which in turn disrupts the normal processing of melanin upwards from the basal layer. Based on our results, we propose a model for the development of age spots that explains the accumulation of melanin and the development of extensive rete ridges in those hyperpigmented lesions. PMID:27621222

  9. Automating generation of textual class definitions from OWL to English.

    Science.gov (United States)

    Stevens, Robert; Malone, James; Williams, Sandra; Power, Richard; Third, Allan

    2011-05-17

    Text definitions for entities within bio-ontologies are a cornerstone of the effort to gain a consensus in understanding and usage of those ontologies. Writing these definitions is, however, a considerable effort and there is often a lag between specification of the main part of an ontology (logical descriptions and definitions of entities) and the development of the text-based definitions. The goal of natural language generation (NLG) from ontologies is to take the logical description of entities and generate fluent natural language. The application described here uses NLG to automatically provide text-based definitions from an ontology that has logical descriptions of its entities, so avoiding the bottleneck of authoring these definitions by hand. To produce the descriptions, the program collects all the axioms relating to a given entity, groups them according to common structure, realises each group through an English sentence, and assembles the resulting sentences into a paragraph, to form as 'coherent' a text as possible without human intervention. Sentence generation is accomplished using a generic grammar based on logical patterns in OWL, together with a lexicon for realising atomic entities. We have tested our output for the Experimental Factor Ontology (EFO) using a simple survey strategy to explore the fluency of the generated text and how well it conveys the underlying axiomatisation. Two rounds of survey and improvement show that overall the generated English definitions are found to convey the intended meaning of the axiomatisation in a satisfactory manner. The surveys also suggested that one form of generated English will not be universally liked; that intrusion of too much 'formal ontology' was not liked; and that too much explicit exposure of OWL semantics was also not liked. Our prototype tools can generate reasonable paragraphs of English text that can act as definitions. The definitions were found acceptable by our survey and, as a result, the

  10. Spot and Runway Departure Advisor

    Science.gov (United States)

    Jung, Yoon Chul

    2013-01-01

    The Spot and Runway Departure Advisor (SARDA) is a research prototype of a decision support tool for ATC tower controllers to assist in manging and controlling traffic on the surface of an airport. SARDA employs a scheduler to generate an optimal runway schedule and gate push-back - spot release sequence and schedule that improves efficiency of surface operations. The advisories for ATC tower controllers are displayed on an Electronic Flight Strip (EFS) system. The human-in-the-loop simulation of the SARDA tool was conducted for east operations of Dallas-Ft. Worth International Airport (DFW) to evaluate performance of the SARDA tool and human factors, such as situational awareness and workload. The results indicates noticeable taxi delay reduction and fuel savings by using the SARDA tool. Reduction in controller workload were also observed throughout the scenario runs. The future plan includes modeling and simulation of the ramp operations of the Charlotte International Airport, and develop a decision support tool for the ramp controllers.

  11. Glare Spot Phase Doppler Anemometry

    Science.gov (United States)

    Hespel, Camille; Ren, Kuanfang; Gréhan, Gérard; Onofri, Fabrice

    2007-06-01

    The Phase Doppler anemometry has been developed to measure simultaneously the velocity and the size of droplets. The measurement of the refractive index would be also interesting since it depends on the temperature and the composition of the particle and its measurement permits both to increase the quality of the diameter measurement and to obtain information on the temperature and/or the composition of the droplets. In this paper, we introduce a Glare Spot Phase Doppler Anemometry which uses two large beams. In this case, the images of the particle formed by the reflected and refracted light, known as glare spots, are separated in space. When a particle passes in the probe volume, the two parts in a signal obtained by a detector in forward direction are then separated in time. If two detectors are used the phase differences between two signals, the distance and the intensity ratio of reflected and refracted parts can be obtained and they provide rich information about the particle diameter and its refractive index, as well as its velocity. This paper is devoted to the numerical study of such a configuration with two theoretical models: geometrical optics and rigorous electromagnetism solution.

  12. Diet of the Tawny Owl Strix aluco in the area of Slovenske gorice (NE Slovenia

    Directory of Open Access Journals (Sweden)

    Janžekovič Franc

    2017-11-01

    Full Text Available The diet of Tawny Owl Strix aluco was studied in the area of Slovenske gorice - NE Slovenia. The analysis was carried out by examining pellets collected at ten locations in the period from 1984 to 2015. From the pellets, 2,121 prey units were isolated. The predominant prey were mammals (Mammalia, 84.8%, followed by birds (Aves, 8.3%, insects (Insecta, 4.7%, frogs (Anura, 1.6% and earthworms (Oligochaeta, 0.5%. Four orders of mammals were found: rodents (Rodentia, insectivores (Insectivora, bats (Chiroptera and carnivores (Carnivora. The most frequent prey in the owls’ diet were voles (Arvicolinae, 46.6% and mice (Murinae, 28.8%, while the number of shrews (Soricidae was low (4.5%. The obtained results are in concordance with the conclusions of other studies. In the area of Slovenske gorice, the Tawny Owl is an opportunistic predator of small mammals with an emphasis on voles and mice. Prey frequencies differ significantly among some localities. Variability in proportions of prey species among localities can also be the result of sampling carried out in different seasons and variability in the population dynamics of small mammals among years. Challenges for future research are to describe seasonal variability of the diet and to evaluate interspecific competition within the guild of night predators of small mammals: Tawny Owl, Long-eared Owl Asio otus, and Barn Owl Tyto alba, which are sympatric in this area.

  13. Owls may use faeces and prey feathers to signal current reproduction.

    Directory of Open Access Journals (Sweden)

    Vincenzo Penteriani

    Full Text Available BACKGROUND: Many animals communicate by marking focal elements of their home range with different kinds of materials. Visual signaling has been demonstrated to play a previously unrecognized role in the intraspecific communication of eagle owls (Bubo bubo, in both territorial and parent-offspring contexts. Visual signals may play a role in a variety of circumstances in this crepuscular and nocturnal species. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that a large amount of extremely visible white faeces and prey feathers appear during the breeding season on posts and plucking sites in proximity to the nest, potentially representing a way for eagle owls to mark their territory. We present descriptive and experimental evidence showing that faeces and prey remains could act as previously unrecognized visual signals in a nocturnal avian predator. This novel signaling behavior could indicate the owls' current reproductive status to potential intruders, such as other territorial owls or non-breeding floaters. Faeces and prey feather markings may also advertise an owl's reproductive status or function in mate-mate communication. CONCLUSIONS/SIGNIFICANCE: We speculate that faeces marks and plucking may represent an overlooked but widespread method for communicating current reproduction to conspecifics. Such marking behavior may be common in birds, and we may now be exploring other questions and mechanisms in territoriality.

  14. Initial Investigation on the Diet of Eastern Grass Owl (Tyto longimembris in Southern Taiwan

    Directory of Open Access Journals (Sweden)

    Wen-Loung Lin

    2007-03-01

    Full Text Available This investigation, undertaken in the two regions of Nanshi and Yujing in Tainan County over the period of 2001 to 2003, included three nests belonging to the Eastern Grass Owl (Tyto longimembris. From these, we collected a total of 157 owl pellets. Analysis and examination of the pellets revealed 329 prey items. More in-depth investigation determined that 95.1% of the Eastern Grass Owl pellets collected consisted of mammal remains, while the remaining 4.9% were made up of bird remains. Of the various types of mammals consumed, rats made up the highest proportion, with a total of 285 rats, accounting for 86.6%. This was followed by 27 shrews and moles, accounting for 8.2%. Hares and birds were seldom caught and consumed. The findings suggested that rats are the main food source of the Eastern Grass Owl, with the Spinus Country-rat (Rattus losea comprising the majority with 136 counted (41.3%, followed by the Formosan Mouse (Mus caroli with 96 counted (29.2%. Regarding biomass, the reversion method was used to calculate that owls at the three nests consumed approximately 22,987 grams of mammal and 480 grams of bird, accounting for 98.0% and 2.0%, respectively. The biomass consumed for each pellet was approximately 149.5 g.

  15. Owls may use faeces and prey feathers to signal current reproduction.

    Science.gov (United States)

    Penteriani, Vincenzo; Delgado, Maria del Mar

    2008-08-20

    Many animals communicate by marking focal elements of their home range with different kinds of materials. Visual signaling has been demonstrated to play a previously unrecognized role in the intraspecific communication of eagle owls (Bubo bubo), in both territorial and parent-offspring contexts. Visual signals may play a role in a variety of circumstances in this crepuscular and nocturnal species. Here, we report that a large amount of extremely visible white faeces and prey feathers appear during the breeding season on posts and plucking sites in proximity to the nest, potentially representing a way for eagle owls to mark their territory. We present descriptive and experimental evidence showing that faeces and prey remains could act as previously unrecognized visual signals in a nocturnal avian predator. This novel signaling behavior could indicate the owls' current reproductive status to potential intruders, such as other territorial owls or non-breeding floaters. Faeces and prey feather markings may also advertise an owl's reproductive status or function in mate-mate communication. We speculate that faeces marks and plucking may represent an overlooked but widespread method for communicating current reproduction to conspecifics. Such marking behavior may be common in birds, and we may now be exploring other questions and mechanisms in territoriality.

  16. Expert2OWL: A Methodology for Pattern-Based Ontology Development.

    Science.gov (United States)

    Tahar, Kais; Xu, Jie; Herre, Heinrich

    2017-01-01

    The formalization of expert knowledge enables a broad spectrum of applications employing ontologies as underlying technology. These include eLearning, Semantic Web and expert systems. However, the manual construction of such ontologies is time-consuming and thus expensive. Moreover, experts are often unfamiliar with the syntax and semantics of formal ontology languages such as OWL and usually have no experience in developing formal ontologies. To overcome these barriers, we developed a new method and tool, called Expert2OWL that provides efficient features to support the construction of OWL ontologies using GFO (General Formal Ontology) as a top-level ontology. This method allows a close and effective collaboration between ontologists and domain experts. Essentially, this tool integrates Excel spreadsheets as part of a pattern-based ontology development and refinement process. Expert2OWL enables us to expedite the development process and modularize the resulting ontologies. We applied this method in the field of Chinese Herbal Medicine (CHM) and used Expert2OWL to automatically generate an accurate Chinese Herbology ontology (CHO). The expressivity of CHO was tested and evaluated using ontology query languages SPARQL and DL. CHO shows promising results and can generate answers to important scientific questions such as which Chinese herbal formulas contain which substances, which substances treat which diseases, and which ones are the most frequently used in CHM.

  17. Genetic consequences of population decline in the Danish population of the little owl (Athene noctua)

    DEFF Research Database (Denmark)

    Pertoldi, Cino; Pellegrino, Irene; Cucco, Maroc

    2012-01-01

    Background: Danish populations of the little owl (Athene noctua) have experienced dramaticdeclines in size over the past century. Before 1960 the little owl population was abundantin Denmark (estimated N>2000), but between 1960 and 1980 the population declinedrapidly, and since 1980 the little ow...

  18. Current status, distribution, and conservation of the Burrowing Owl (Speotyto cunicularia) in midwestern and western North America

    Science.gov (United States)

    Steven R. Sheffield

    1997-01-01

    The Burrowing Owl (Speotyto cunicularia) inhabits open prairie grassland habitat in the midwestern and western US and Canada. For several years now, numbers of this species in North America have been declining at an alarming rate. Currently, Burrowing Owls are listed as endangered in Canada and threatened in Mexico. In the United States, the...

  19. Survey on birds of prey and owls Falconiformes and Strigiformes) on Java sea islands: correction and additions.

    NARCIS (Netherlands)

    Nijman, V.

    2005-01-01

    ): In Southeast Asia the short-eared owl Asio flammeus is a northern migrant and is normally not recorded south of Singapore and, rarely, northern Borneo. The occurrence of short-eared owl in the Kangean archipelago, Java Sea, has been noted in several publications, including a recent one in this

  20. On the barn owl's visual pre-attack behavior: 1. Structure of head movements and motion patterns

    NARCIS (Netherlands)

    Ohayon, S.; Willigen, R.F. van der; Wagner, H.; Katsman, I.; Rivlin, E.

    2006-01-01

    Barn owls exhibit a rich repertoire of head movements before taking off for prey capture. These movements occur mainly at light levels that allow for the visual detection of prey. To investigate these movements and their functional relevance, we filmed the pre-attack behavior of barn owls. Off-line

  1. Chapter 2: A historical perspective on the population decline of the cactus ferruginous pygmy-owl in Arizona

    Science.gov (United States)

    R. Roy Johnson; Jean-Luc E. Cartron; Lois T. Haight; Russell B. Duncan; Kenneth J. Kingsley

    2000-01-01

    The cactus ferruginous pygmy-owl (Glaucidium brasilianum cactorum) was discovered in the U.S. by Bendire in 1872 in the Tucson area (Coues 1872). During the next five decades, naturalists collected many specimens of this owl and typically described the subspecies as common or fairly common along some streams and rivers of central and southern Arizona...

  2. Prey selection of Tawny owls (Strix aluco) on Yellow necked mouse and Bank Vole

    DEFF Research Database (Denmark)

    Forsom, H. M.; Sunde, P.; Overskaug, K.

    As predators owls may have a strong impact on mortality of their favourite prey, and may therefore act as important selective agents on their prey species. Little is known, however, about whether owls choose prey randomly or if some prey items suffer a higher risk of predation due to certain life...

  3. Spots on AG Virginis - paradigm or panacea?

    International Nuclear Information System (INIS)

    Bell, S.A.; Rainger, P.P.; Hilditch, R.W.

    1990-01-01

    New photometric and spectroscopic observations of the eclipsing binary AG Vir are presented. Medium-resolution spectroscopy has allowed the measurement of velocities for the secondary component for the first time. The V light curve shows many of the features seen in previous studies of this system. A full analysis of the spectroscopic and photometric data has been made which suggests that the system is either in a marginal state of contact or a deep-contact configuration depending on the type of spot model invoked. AG Vir constitutes an excellent example of the expected manifestations of spot activity on a light curve. It also demonstrates the ease with which the spot phenomenon can be invoked to explain the appearance of a light curve and to provide conflicting results. (author)

  4. PREDICTING RELEVANT EMPTY SPOTS IN SOCIAL INTERACTION

    Institute of Scientific and Technical Information of China (English)

    Yoshiharu MAENO; Yukio OHSAWA

    2008-01-01

    An empty spot refers to an empty hard-to-fill space which can be found in the records of the social interaction, and is the clue to the persons in the underlying social network who do not appear in the records. This contribution addresses a problem to predict relevant empty spots in social interaction. Homogeneous and inhomogeneous networks are studied as a model underlying the social interaction. A heuristic predictor function method is presented as a new method to address the problem. Simulation experiment is demonstrated over a homogeneous network. A test data set in the form of market baskets is generated from the simulated communication. Precision to predict the empty spots is calculated to demonstrate the performance of the presented method.

  5. MASCEM: EPEX SPOT Day-Ahead market integration and simulation

    DEFF Research Database (Denmark)

    Santos, Gabriel; Fernandes, Ricardo; Pinto, Tiago

    2015-01-01

    . It is crucial to MASCEM to have the ability to simulate as many market models and player types as possible, thus enhancing the ability to recreate the electricity markets reality in its maximum possible extent. This paper presents the EPEX Spot Day-Ahead market integration in MASCEM. EPEX Spot SE's mission...

  6. weSPOT: Working Environment with Social and Personal Open Tools for inquiry based learning

    NARCIS (Netherlands)

    Rusman, Ellen; Firssova, Olga; Prinsen, Fleur; Specht, Marcus; Ternier, Stefaan

    2014-01-01

    Presentation of the weSPOT model for Inquiry based learning developed by a EC-funded Research weSPOT project, held at a potential testbed - Sint-Jans College in Hoensbroek, Netherlands on May 20, 2014

  7. Emerging hot spot analysis

    DEFF Research Database (Denmark)

    Reinau, Kristian Hegner

    Traditionally, focus in the transport field, both politically and scientifically, has been on private cars and public transport. Freight transport has been a neglected topic. Recent years has seen an increased focus upon congestion as a core issue across Europe, resulting in a great need for know...... speed data for freight. Secondly, the analytical methods used, space-time cubes and emerging hot spot analysis, are also new in the freight transport field. The analysis thus estimates precisely how fast freight moves on the roads in Northern Jutland and how this has evolved over time....

  8. You mob my owl, I'll mob yours: birds play tit-for-tat game

    Science.gov (United States)

    Krama, Tatjana; Vrublevska, Jolanta; Freeberg, Todd M.; Kullberg, Cecilia; Rantala, Markus J.; Krams, Indrikis

    2012-01-01

    Reciprocity is fundamental to cooperative behaviour and has been verified in theoretical models. However, there is still limited experimental evidence for reciprocity in non-primate species. Our results more decisively clarify that reciprocity with a tit-for-tat enforcement strategy can occur among breeding pied flycatchers Ficedula hypoleuca separate from considerations of byproduct mutualism. Breeding pairs living in close proximity (20–24 m) did exhibit byproduct mutualism and always assisted in mobbing regardless of their neighbours' prior actions. However, breeding pairs with distant neighbours (69–84 m) either assisted or refused to assist in mobbing a predatory owl based on whether or not the distant pair had previously helped them in their own nest defense against the predator. Clearly, these birds are aware of their specific spatial security context, remember their neighbours' prior behaviour, and choose a situation-specific strategic course of action, which could promote their longer-term security, a capacity previously thought unique to primates. PMID:23150772

  9. Multiple paternity in polyandrous barn owls (Tyto alba.

    Directory of Open Access Journals (Sweden)

    Isabelle Henry

    Full Text Available In polyandrous species females produce successive clutches with several males. Female barn owls (Tyto alba often desert their offspring and mate to produce a 2(nd annual brood with a second male. We tested whether copulating during chick rearing at the 1(st annual brood increases the male's likelihood to obtain paternity at the 2(nd annual breeding attempt of his female mate in case she deserts their brood to produce a second brood with a different male. Using molecular paternity analyses we found that 2 out of 26 (8% second annual broods of deserting females contained in total 6 extra-pair young out of 15 nestlings. These young were all sired by the male with whom the female had produced the 1(st annual brood. In contrast, none of the 49 1(st annual breeding attempts (219 offspring and of the 20 2(nd annual breeding attempts (93 offspring of non-deserting females contained extra-pair young. We suggest that female desertion can select male counter-strategies to increase paternity and hence individual fitness. Alternatively, females may copulate with the 1(st male to derive genetic benefits, since he is usually of higher quality than the 2(nd male which is commonly a yearling individual.

  10. Evaluation on the Emergency Capacity of the Mountain-type Scenic Spot based on Matter-units Analysis Model:A case study of Henan Yuantaishan Scenic spot%基于物元模型的山岳型景区应急能力评价研究*--以河南云台山景区为例

    Institute of Scientific and Technical Information of China (English)

    张永领; 张红

    2014-01-01

    山地灾害的破坏性和山地地形地貌特征给山岳型景区突发事件应急救援带来了巨大挑战,因此亟须对山岳型景区的应急能力进行评价,全面提高山岳型景区突发事件的应急救援能力。以应急管理周期理论和山地突发事件特征为基础,构建了山岳型景区应急能力评价指标体系,包括9个一级指标和29个二级指标;建立了以物元分析法为基础的山岳型应急能力评价模型,并以山岳型景区云台山为例进行评价,结果表明:基于物元分析法的山岳型景区应急能力评价模型,不仅能够科学评定应急能力的等级,而且还能揭示应急能力的发展和转化趋势,评估结果可为景区应急能力建设的科学决策提供参考。%Mountain-type scenic spots have emergency rescue difficulty because of devastation of mountain disasters and typical mountain topography characteristics,therefore it needs to evaluate the emergency capacity for emergent events and comprehen-sively improve the emergency response capabilities for the emergency capacity to emergent events.The assessment index system of emergency capacity for the mountain-type emergencies is constructed from 9 level indicators and 29 secondary indicators based on 4-stage emergency management and Mountain-type scenic spot characteristics;the emergency capacity evaluation model was established based on the matter-element analysis method.And emergency capacity was evaluated for the Yuntaishan scenic spot as a case study.The result shows that the emergency capacity assessment model based on matter-element analysis method not only can carry on the scientific evaluation to the emergency ability level,but also can reveal the emergency ability development and transformation trend,which can offer references to scientific decision-making of emergency capacity for the mountain-type scenic spots.

  11. The sweet spots in human communication.

    Science.gov (United States)

    Salem, Philip

    2011-07-01

    In baseball, the sweet spot is a special place on a bat where the batter can hit the ball with the most power. It is the place where the performances of the batter and pitcher collide with maximum effect. It is the place where the dynamic tension between opponents leads to transformation. The dynamic tension in all living systems is between similarity and difference. Chaos and complexity scholars recognized this tension as amounts of information. When the amounts of information were high, but not too high, the system moved to the edge of chaos, to the complexity regime, to strange attractors, or to chaos, depending on the model. The sweet spot is that range of relative variety, just the proper mix of similarity and difference, leading to transformation. This essay contains a model of human communication as an emergent social process with its own sweet spots. The essay also includes a description of current literature highlighting tensions between similarity and difference, and there is an exploration of the potential to move from one basin of attraction to another. The primary constraints on finding communication sweet spots are paradigmatic - adopting a process orientation, discovering the proper parameters, bracketing sequences to define initial conditions, and understanding the strengths and weaknesses of various modeling techniques.

  12. Using AberOWL for fast and scalable reasoning over BioPortal ontologies

    KAUST Repository

    Slater, Luke

    2016-08-08

    Background: Reasoning over biomedical ontologies using their OWL semantics has traditionally been a challenging task due to the high theoretical complexity of OWL-based automated reasoning. As a consequence, ontology repositories, as well as most other tools utilizing ontologies, either provide access to ontologies without use of automated reasoning, or limit the number of ontologies for which automated reasoning-based access is provided. Methods: We apply the AberOWL infrastructure to provide automated reasoning-based access to all accessible and consistent ontologies in BioPortal (368 ontologies). We perform an extensive performance evaluation to determine query times, both for queries of different complexity and for queries that are performed in parallel over the ontologies. Results and conclusions: We demonstrate that, with the exception of a few ontologies, even complex and parallel queries can now be answered in milliseconds, therefore allowing automated reasoning to be used on a large scale, to run in parallel, and with rapid response times.

  13. Seasonal survival rates and causes of mortality of Little Owls in Denmark

    DEFF Research Database (Denmark)

    Thorup, Kasper; Pedersen, Dorthe; Sunde, Peter

    2013-01-01

    Survival rate is an essential component of population dynamics; therefore, identification of variation in mortality rates and the factors that influence them might be of key importance in understanding why populations increase or decrease. In Denmark, the Little Owl Athene noctua, a species...... the causes of current survival rates, we estimated age- and season-specific survival rates and causes of mortality in Danish Little Owls on the basis of ringed birds 1920–2002, radio tagged adult and juveniles 2005–2008 and nest surveys 2006–2008. We estimate that 32 % of all eggs fledge and survive to 2...... the breeding season. In radio-tagged adults and fledged juveniles, accidents in buildings and other human infrastructures were responsible for two-thirds of all fatalities. Anthropogenic habitats currently comprise the nesting and roosting habitats for the last Danish Little Owls. The accidental deaths...

  14. Cosmicflows-3: Cold Spot Repeller?

    Energy Technology Data Exchange (ETDEWEB)

    Courtois, Hélène M.; Graziani, Romain; Dupuy, Alexandra [University of Lyon, UCB Lyon 1, CNRS/IN2P3, IPN, Lyon (France); Tully, R. Brent [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Hoffman, Yehuda [Racah Institute of Physics, Hebrew University, Jerusalem, 91904 (Israel); Pomarède, Daniel [Institut de Recherche sur les Lois Fondamentales de l’Univers, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)

    2017-09-20

    The three-dimensional gravitational velocity field within z ∼ 0.1 has been modeled with the Wiener filter methodology applied to the Cosmicflows-3 compilation of galaxy distances. The dominant features are a basin of attraction and two basins of repulsion. The major basin of attraction is an extension of the Shapley concentration of galaxies. One basin of repulsion, the Dipole Repeller, is located near the anti-apex of the cosmic microwave background dipole. The other basin of repulsion is in the proximate direction toward the “Cold Spot” irregularity in the cosmic microwave background. It has been speculated that a vast void might contribute to the amplitude of the Cold Spot from the integrated Sachs–Wolfe effect.

  15. 77 FR 14061 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Northern Spotted Owl

    Science.gov (United States)

    2012-03-08

    ... ranges from dry, fire-prone forests to moist old-growth conifer forest to a mix of conifers and hardwood trees. Thousands of species occur in these forest ecosystems, including other listed species with very... wildfires; hazard tree removal; removal of younger, shade-intolerant conifers to reduce competition with...

  16. Using MODIS NDVI phenoclasses and phenoclusters to characterize wildlife habitat: Mexican spotted owl as a case study

    Science.gov (United States)

    Serra J. Hoagland; Paul Beier; Danny Lee

    2018-01-01

    Most uses of remotely sensed satellite data to characterize wildlife habitat have used metrics such as mean NDVI (Normalized Difference Vegetation Index) in a year or season. These simple metrics do not take advantage of the temporal patterns in NDVI within and across years and the spatial arrangement of cells with various temporal NDVI signatures. Here we use 13 years...

  17. 77 FR 27010 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Northern Spotted Owl

    Science.gov (United States)

    2012-05-08

    ... Convention Center, 777 NE Martin Luther King Blvd., Portland, Oregon; 503-235-7575. Public Meetings: Public information meetings will be held at: University of Washington, Tacoma Campus, 1900 Commerce St., Jane Russell..., California 96001; 530-229-0036; Oregon Convention Center, Room C-120, 777 NE Martin Luther King Blvd...

  18. Post-fledging behaviour of juveniles in the little owl (Athene noctua)

    DEFF Research Database (Denmark)

    Pedersen, Dorthe; Thorup, Kasper; Sunde, Peter

    2013-01-01

    Before dispersal, social and spatial behaviour in owls has only been briefly studied. We used radio tracking to monitor age-influenced social and spatial behaviour in 10 juvenile Little Owls (Athene noctua) from nests in Northern Jutland, Denmark. On average, the post-fledging dependency period.......53 ha (mean ± SD) from fledging to independence and 3.25 ± 4.15 ha from independence to dispersal.Within the first 40 days after fledging, the nightly distance from the nest and the distance between siblings increased, and the frequency and intensity of begging calls decreased. These results were...

  19. KFC Server: interactive forecasting of protein interaction hot spots.

    Science.gov (United States)

    Darnell, Steven J; LeGault, Laura; Mitchell, Julie C

    2008-07-01

    The KFC Server is a web-based implementation of the KFC (Knowledge-based FADE and Contacts) model-a machine learning approach for the prediction of binding hot spots, or the subset of residues that account for most of a protein interface's; binding free energy. The server facilitates the automated analysis of a user submitted protein-protein or protein-DNA interface and the visualization of its hot spot predictions. For each residue in the interface, the KFC Server characterizes its local structural environment, compares that environment to the environments of experimentally determined hot spots and predicts if the interface residue is a hot spot. After the computational analysis, the user can visualize the results using an interactive job viewer able to quickly highlight predicted hot spots and surrounding structural features within the protein structure. The KFC Server is accessible at http://kfc.mitchell-lab.org.

  20. Intraday price dynamics in spot and derivatives markets

    Science.gov (United States)

    Kim, Jun Sik; Ryu, Doojin

    2014-01-01

    This study examines intraday relationships among the spot index, index futures, and the implied volatility index based on the VAR(1)-asymmetric BEKK-MGARCH model. Analysis of a high-frequency dataset from the Korean financial market confirms that there is a strong intraday market linkage between the spot index, KOSPI200 futures, and VKOSPI and that asymmetric volatility behaviour is clearly present in the Korean market. The empirical results indicate that the futures return shock affects the spot market more severely than the spot return shock affects the futures market, though there is a bi-directional causal relationship between the spot and futures markets. Our results, based on a high-quality intraday dataset, satisfy both the positive risk-return relationship and asymmetric volatility effect, which are not reconciled in the frameworks of previous studies.

  1. Black-spot poison ivy.

    Science.gov (United States)

    Schram, Sarah E; Willey, Andrea; Lee, Peter K; Bohjanen, Kimberly A; Warshaw, Erin M

    2008-01-01

    In black-spot poison ivy dermatitis, a black lacquerlike substance forms on the skin when poison ivy resin is exposed to air. Although the Toxicodendron group of plants is estimated to be the most common cause of allergic contact dermatitis in the United States, black-spot poison ivy dermatitis is relatively rare.

  2. Rocky Mountain spotted fever, Colombia.

    Science.gov (United States)

    Hidalgo, Marylin; Orejuela, Leonora; Fuya, Patricia; Carrillo, Pilar; Hernandez, Jorge; Parra, Edgar; Keng, Colette; Small, Melissa; Olano, Juan P; Bouyer, Donald; Castaneda, Elizabeth; Walker, David; Valbuena, Gustavo

    2007-07-01

    We investigated 2 fatal cases of Rocky Mountain spotted fever that occurred in 2003 and 2004 near the same locality in Colombia where the disease was first reported in the 1930s. A retrospective serosurvey of febrile patients showed that > 21% of the serum samples had antibodies aaainst spotted fever group rickettsiae.

  3. Advances in spot curing technology

    International Nuclear Information System (INIS)

    Burga, R.

    1999-01-01

    A brief review of spot curing technology was presented. The process which a spot of energy of a specific wavelength bandwidth and irradiance is used to cause a coating, encapsulant or adhesive to change from a liquid to a solid state

  4. The design of LMJ focal spots for indirect drive experiments

    International Nuclear Information System (INIS)

    Le Garrec, B J; Sajer, J M

    2008-01-01

    LMJ is a 240 high power laser beam facility for achieving laser matter interaction experiments, high energy density science, including the demonstration of fusion ignition through Inertial Confinement. The Laser Integration Line (LIL) facility is currently a 4-beam prototype for LMJ. The intensity I 0 at the focal spot centre drives hydrodynamic and plasma instabilities and the intensity in the wings must be low to go through the laser entrance Hohlraum. A simple model has been developed to compute the LMJ focal spot. The model gives the intensity at the centre as a function of the focal spot area at 3% of the maximum

  5. A telemetry study of the social organization of a tawny owl (Strix aluco) population

    DEFF Research Database (Denmark)

    Sunde, Peter; Bølstad, Mikkel S.

    2004-01-01

    The spatial dispersion and social interactions were studied in 11 neighbouring pairs of radio-tagged tawny owls Strix aluco in a deciduous wood in Denmark from 1998-2001. The numbers and shapes of territories were stable throughout the survey and similar to a mapping made 40 years earlier. The home...... involving one owl only from each pair. The dispute rate between neighbouring pairs correlated positively with home-range overlap. The total annual mortality was 21% (95% CI: 6-33%). Dead owners were usually replaced within 1-2 months. Two out of four cases of radio-tagged owls disappearing from...

  6. Modelling NOX concentrations through CFD-RANS in an urban hot-spot using high resolution traffic emissions and meteorology from a mesoscale model

    Science.gov (United States)

    Sanchez, Beatriz; Santiago, Jose Luis; Martilli, Alberto; Martin, Fernando; Borge, Rafael; Quaassdorff, Christina; de la Paz, David

    2017-08-01

    Air quality management requires more detailed studies about air pollution at urban and local scale over long periods of time. This work focuses on obtaining the spatial distribution of NOx concentration averaged over several days in a heavily trafficked urban area in Madrid (Spain) using a computational fluid dynamics (CFD) model. A methodology based on weighted average of CFD simulations is applied computing the time evolution of NOx dispersion as a sequence of steady-state scenarios taking into account the actual atmospheric conditions. The inputs of emissions are estimated from the traffic emission model and the meteorological information used is derived from a mesoscale model. Finally, the computed concentration map correlates well with 72 passive samplers deployed in the research area. This work reveals the potential of using urban mesoscale simulations together with detailed traffic emissions so as to provide accurate maps of pollutant concentration at microscale using CFD simulations.

  7. The tissue microarray OWL schema: An open-source tool for sharing tissue microarray data

    Directory of Open Access Journals (Sweden)

    Hyunseok P Kang

    2010-01-01

    Full Text Available Background: Tissue microarrays (TMAs are enormously useful tools for translational research, but incompatibilities in database systems between various researchers and institutions prevent the efficient sharing of data that could help realize their full potential. Resource Description Framework (RDF provides a flexible method to represent knowledge in triples, which take the form Subject- Predicate-Object. All data resources are described using Uniform Resource Identifiers (URIs, which are global in scope. We present an OWL (Web Ontology Language schema that expands upon the TMA data exchange specification to address this issue and assist in data sharing and integration. Methods: A minimal OWL schema was designed containing only concepts specific to TMA experiments. More general data elements were incorporated from predefined ontologies such as the NCI thesaurus. URIs were assigned using the Linked Data format. Results: We present examples of files utilizing the schema and conversion of XML data (similar to the TMA DES to OWL. Conclusion: By utilizing predefined ontologies and global unique identifiers, this OWL schema provides a solution to the limitations of XML, which represents concepts defined in a localized setting. This will help increase the utilization of tissue resources, facilitating collaborative translational research efforts.

  8. Chapter 6. Conservation status of flammulated owls in the United States

    Science.gov (United States)

    D. Archibald McCallum

    1994-01-01

    The status of the flammulated owl will be evaluated in this chapter by asking a series of critical questions about the species and its habitat. Answers to these questions will be used to reach one of the following conclusions: (1) populations in the United States are secure and will likely remain so given current land management practices; (2) populations are in peril...

  9. Brent goose colonies near snowy owls: Internest distances in relation to breeding arctic fox densities

    NARCIS (Netherlands)

    Kharitonov, S.P.; Ebbinge, B.S.; De Fouw, J.

    2013-01-01

    It was shown that in the years when the numbers of the Arctic foxes are high, even though the lemming numbers are high as well, Brent geese nest considerably closer to owls' nests than in the years with low Arctic fox numbers. At values of the Arctic fox densities greater than one breeding pair per

  10. Territories of flammulated owls (Otus flammeolus): Is occupancy a measure of habitat quality?

    Science.gov (United States)

    Brian D. Linkhart; Richard T. Reynolds

    1997-01-01

    Annual territory occupancy by Flammulated Owls (Otus flammeolus) in Colorado was evaluated from 1981-1996. Fourteen territories occurred within a 452 ha study area. Each year, three to six territories were occupied by breeding pairs and three to seven were occupied by unpaired males. Territories were occupied by breeding pairs a mean of 5.1 years (...

  11. Some Guides to Discovery About Elm Trees, Owls, Cockroaches, Earthworms, Cement and Concrete.

    Science.gov (United States)

    Busch, Phyllis S.

    The introduction emphasizes the need for environmental and conservation education, and advocates an inquiry approach. Outdoor resources available to every school are listed. Detailed suggestions are made for investigating cement and concrete, cockroaches, earthworms, elm trees, and owls. In each case general background information and a list of…

  12. 75 FR 63800 - Information Collection; Commercial Use of the Woodsy Owl Symbol

    Science.gov (United States)

    2010-10-18

    ... to collect royalty fees. Commercial use includes replicating Woodsy Owl symbol or logo on items, such... royalty fees. Information collected includes, but is not limited to, tenure of business or non-profit... Forest Service royalty fee. 5. Royalty fee due based on sales quantity and price. 6. Description and...

  13. Optical Waveguide Lightmode Spectroscopy (OWLS as a Sensor for Thin Film and Quantum Dot Corrosion

    Directory of Open Access Journals (Sweden)

    Jinke Tang

    2012-12-01

    Full Text Available Optical waveguide lightmode spectroscopy (OWLS is usually applied as a biosensor system to the sorption-desorption of proteins to waveguide surfaces. Here, we show that OWLS can be used to monitor the quality of oxide thin film materials and of coatings of pulsed laser deposition synthesized CdSe quantum dots (QDs intended for solar energy applications. In addition to changes in data treatment and experimental procedure, oxide- or QD-coated waveguide sensors must be synthesized. We synthesized zinc stannate (Zn2SnO4 coated (Si,TiO2 waveguide sensors, and used OWLS to monitor the relative mass of the film over time. Films lost mass over time, though at different rates due to variation in fluid flow and its physical effect on removal of film material. The Pulsed Laser Deposition (PLD technique was used to deposit CdSe QD coatings on waveguides. Sensors exposed to pH 2 solution lost mass over time in an expected, roughly exponential manner. Sensors at pH 10, in contrast, were stable over time. Results were confirmed with atomic force microscopy imaging. Limiting factors in the use of OWLS in this manner include limitations on the annealing temperature that maybe used to synthesize the oxide film, and limitations on the thickness of the film to be studied. Nevertheless, the technique overcomes a number of difficulties in monitoring the quality of thin films in-situ in liquid environments.

  14. Survival of male Tengmalm’s owls increases with cover of old forest in the territory

    NARCIS (Netherlands)

    Hakkarainen, H.; Korpimäki, E.; Laaksonen, T.; Nikula, A.; Suorsa, P.

    2008-01-01

    The loss and fragmentation of forest habitats have been considered to pose a worldwide threat to the viability of forest-dwelling animals, especially to species that occupy old forests. We investigated whether the annual survival of sedentary male Tengmalm’s owls Aegolius funereus was associated

  15. Low frequency eardrum directionality in the barn owl induced by sound transmission through the interaural canal

    DEFF Research Database (Denmark)

    Kettler, Lutz; Christensen-Dalsgaard, Jakob; Larsen, Ole Næsbye

    2016-01-01

    . Significant sound transmission across the interaural canal occurred at low frequencies. The sound transmission induces considerable eardrum directionality in a narrow band from 1.5 to 3.5 kHz. This is below the frequency range used by the barn owl for locating prey, but may conceivably be used for locating...

  16. Practical querying of temporal data via OWL 2 QL and SQL: 2011

    CSIR Research Space (South Africa)

    Klarman, S

    2013-12-01

    Full Text Available We develop a practical approach to querying temporal data stored in temporal SQL:2011 databases through the semantic layer of OWL 2 QL ontologies. An interval-based temporal query language (TQL), which we propose for this task, is defined via...

  17. Ecology and conservation of the cactus ferruginous pygmy-owl in Arizona

    Science.gov (United States)

    Jean-Luc E. Cartron; Deborah M. Finch

    2000-01-01

    This report is the result of a cooperative effort by the Rocky Mountain Research Station and the USDA Forest Service Region 3, with participation by the Arizona Game and Fish Department and the Bureau of Land Management. It assesses the state of knowledge related to the conservation status of the cactus ferruginous pygmy-owl in Arizona. The population decline of this...

  18. Chapter 6: Research needs for the conservation of the cactus ferruginous pygmy-owl in Arizona

    Science.gov (United States)

    Jean-Luc E. Cartron; W. Scott Richardson; Deborah M. Finch; David J. Krueper

    2000-01-01

    In this chapter, we describe research needs for the conservation of the cactus ferruginous pygmy-owl (Glaucidium brasilianum cactorum) in Arizona. Estimates of population size, structure, and dynamics, as well as demographic data, are needed for the recovery team to formulate sound population objectives. Habitat loss due to residential development...

  19. Comparison of reasoners for large ontologies in the OWL 2 EL profile

    NARCIS (Netherlands)

    Dentler, K.; Cornet, R.; ten Teije, A.C.M.; de Keizer, N.F.

    2011-01-01

    This paper provides a survey to and a comparison of state-of-the-art Semantic Web reasoners that succeed in classifying large ontologies expressed in the tractable OWL 2 EL profile. Reasoners are characterized along several dimensions: The first dimension comprises underlying reasoning

  20. High population density of Little Owl (Athene noctua) in Hortobagy National Park, Hungary, Central Europe

    Czech Academy of Sciences Publication Activity Database

    Šálek, Martin; Chrenková, M.; Kipson, M.

    2013-01-01

    Roč. 61, č. 1 (2013), s. 165-169 ISSN 1505-2249 Institutional support: RVO:68081766 Keywords : Little Owl * population density * distribution * breeding places * Hortobagy National Park * Hungary Subject RIV: EH - Ecology, Behaviour Impact factor: 0.554, year: 2013

  1. The Ecology of the Ural Owl at South-Western Border of Its Distribution (Slovenia

    Directory of Open Access Journals (Sweden)

    Al Vrezec

    2016-04-01

    Full Text Available In Slovenia the Ural Owl (Strix uralensis is on its south-western limit of distribution and belongs to the southern subspecies Strix uralensis macroura. Dark coloured owls are characteristic for this subspecies and represent between 5 to 15% of the population. Slovenian breeding population size is estimated at 400 to 700 pairs. The densities of territories ranges between 0.9 to 13.4 territories per 10 km2, and the highest are reached in mountain forests of southern Dinaric region. In the forests with dominant deciduous trees, e.g. Beech (Fagus sylvatica and Pedinculate Oak (Quercus robur, the breeding densities are significantly higher than in the forests with higher proportion of coniferous trees, e.g. Norway Spruce (Picea abies. The species does not select specific altitude and throughout Slovenia it occurs between 150 and 1600 m a.s.l.  The most of the nest found at natural nest-sites were in tree holes or semi-holes (56% and at the tree stumps (20%. Nest boxes were occupied less frequently in Slovenia with occupancy rate of 29%. At least in mountain regions breeding begins quite late, between 15 March to 21 June. Average clutch size is 3.3 ± 1.0 eggs per nest. About 80% of all nests are successful raising at least one young. The diet shifts significantly between breeding and non-breeding period due to the seasonality in prey availability. According to the biomass the most important prey in breeding period are mice (Muridae, voles (Arvicollidae and mole (Talpa europaea, but in the non-breeding period voles and dormice (Gliridae predominate. Large Fat Dormouse (Glis glis seems to have very important role in the post-breeding period, but not in the breeding period due to its dormancy. As a large forest-dwelling predator the Ural Owl shapes the raptor community in the forest by excluding mezopredator species, as Tawny Owl (Strix aluco, what allows smaller raptors, e.g. Boreal Owl (Aegolius funereus to expend their ranges to lower elevations

  2. Phenotypic and Functional Characterization of Peripheral Blood Lymphocytes from Various Age- and Sex-Specific Groups of Owl Monkeys (Aotus nancymaae).

    Science.gov (United States)

    Nehete, Pramod N; Nehete, Bharti P; Chitta, Sriram; Williams, Lawrence E; Abee, Christian R

    2017-02-01

    Owl monkeys (Aotus nancymaae) are New World NHP that serve an important role in vaccine development and as a model for human disease conditions such as malaria. Despite the past contributions of this animal model, limited information is available about the phenotype and functional properties of peripheral blood lymphocytes in reference to sex and age. Using a panel of human antibodies and a set of standardized human immune assays, we identified and characterized various peripheral blood lymphocyte subsets, evaluated the immune functions of T cells, and analyzed cytokines relative to sex and age in healthy owl monkeys. We noted age- and sex-dependent changes in CD28+ (an essential T cell costimulatory molecule) and CD95+ (an apoptotic surface marker) T cells and various levels of cytokines in the plasma. In immune assays of freshly isolated peripheral blood mononuclear cells, IFNγ and perforin responses were significantly higher in female than in male monkeys and in young adults than in juvenile and geriatric groups, despite similar lymphocyte (particularly T cell) populations in these groups. Our current findings may be useful in exploring Aotus monkeys as a model system for the study of aging, susceptibility to infectious diseases, and age-associated differences in vaccine efficacy, and other challenges particular to pediatric and geriatric patients.

  3. Spotting psychopaths using technology.

    Science.gov (United States)

    Hulbert, Sarah; Adeli, Hojjat

    2015-01-01

    For the past three and a half decades, the Psychopathy Checklist-Revised (PCL-R) and the self-report Psychopathic Personality Inventory-Revised (PPI-R) have been the standard measures for the diagnosis of psychopathy. Technological approaches can enhance these diagnostic methodologies. The purpose of this paper is to present a state-of-the-art review of various technological approaches for spotting psychopathy, such as electroencephalogram (EEG), magnetic resonance imaging (MRI), functional MRI (fMRI), transcranial magnetic stimulation (TMS), and other measures. Results of EEG event-related potential (ERP) experiments support the theory that impaired amygdala function may be responsible for abnormal fear processing in psychopathy, which can ultimately manifest as psychopathic traits, as outlined by the PCL-R or PPI-R. Imaging studies, in general, point to reduced fear processing capabilities in psychopathic individuals. While the human element, introduced through researcher/participant interactions, can be argued as unequivocally necessary for diagnosis, these purely objective technological approaches have proven to be useful in conjunction with the subjective interviewing and questionnaire methods for differentiating psychopaths from non-psychopaths. Furthermore, these technologies are more robust than behavioral measures, which have been shown to fail.

  4. Moonstruck primates: owl monkeys (Aotus need moonlight for nocturnal activity in their natural environment.

    Directory of Open Access Journals (Sweden)

    Eduardo Fernández-Duque

    2010-09-01

    Full Text Available Primates show activity patterns ranging from nocturnality to diurnality, with a few species showing activity both during day and night. Among anthropoids (monkeys, apes and humans, nocturnality is only present in the Central and South American owl monkey genus Aotus. Unlike other tropical Aotus species, the Azara's owl monkeys (A. azarai of the subtropics have switched their activity pattern from strict nocturnality to one that also includes regular diurnal activity. Harsher climate, food availability, and the lack of predators or diurnal competitors, have all been proposed as factors favoring evolutionary switches in primate activity patterns. However, the observational nature of most field studies has limited an understanding of the mechanisms responsible for this switch in activity patterns. The goal of our study was to evaluate the hypothesis that masking, namely the stimulatory and/or inhibitory/disinhibitory effects of environmental factors on synchronized circadian locomotor activity, is a key determinant of the unusual activity pattern of Azara's owl monkeys. We use continuous long-term (6-18 months 5-min-binned activity records obtained with actimeter collars fitted to wild owl monkeys (n =  10 individuals to show that this different pattern results from strong masking of activity by the inhibiting and enhancing effects of ambient luminance and temperature. Conclusive evidence for the direct masking effect of light is provided by data showing that locomotor activity was almost completely inhibited when moonlight was shadowed during three lunar eclipses. Temperature also negatively masked locomotor activity, and this masking was manifested even under optimal light conditions. Our results highlight the importance of the masking of circadian rhythmicity as a determinant of nocturnality in wild owl monkeys and suggest that the stimulatory effects of dim light in nocturnal primates may have been selected as an adaptive response to

  5. Crude oil spot market pricing: Pearsonian analysis of crude oil spot market prices

    International Nuclear Information System (INIS)

    Akinnusi, Ayo

    1994-01-01

    This paper presents a brief overview of crude oil pricing before describing a study of sets of 1991 spot market prices, and examining Pearson's model. Empirical distribution characteristics for 14 crude oils are tabulated, and skewness-kurtosis relationship and implication are considered. (UK)

  6. Multipurpose optimization models for high level waste vitrification

    International Nuclear Information System (INIS)

    Hoza, M.

    1994-08-01

    Optimal Waste Loading (OWL) models have been developed as multipurpose tools for high-level waste studies for the Tank Waste Remediation Program at Hanford. Using nonlinear programming techniques, these models maximize the waste loading of the vitrified waste and optimize the glass formers composition such that the glass produced has the appropriate properties within the melter, and the resultant vitrified waste form meets the requirements for disposal. The OWL model can be used for a single waste stream or for blended streams. The models can determine optimal continuous blends or optimal discrete blends of a number of different wastes. The OWL models have been used to identify the most restrictive constraints, to evaluate prospective waste pretreatment methods, to formulate and evaluate blending strategies, and to determine the impacts of variability in the wastes. The OWL models will be used to aid in the design of frits and the maximize the waste in the glass for High-Level Waste (HLW) vitrification

  7. Spot Welding of Honeycomb Structures

    Science.gov (United States)

    Cohal, V.

    2017-08-01

    Honeycomb structures are used to prepare meals water jet cutting machines for textile. These honeycomb structures are made of stainless steel sheet thickness of 0.1-0.2 mm. Corrugated sheet metal strips are between two gears with special tooth profile. Hexagonal cells for obtaining these strips are welded points between them. Spot welding device is three electrodes in the upper part, which carries three welding points across the width of the strip of corrugated sheet metal. Spot welding device filled with press and advance mechanisms. The paper presents the values of the regime for spot welding.

  8. On the relationships between electron spot size, focal spot size, and virtual source position in Monte Carlo simulations

    International Nuclear Information System (INIS)

    Sterpin, E.; Chen, Y.; Lu, W.; Mackie, T. R.; Olivera, G. H.; Vynckier, S.

    2011-01-01

    Purpose: Every year, new radiotherapy techniques including stereotactic radiosurgery using linear accelerators give rise to new applications of Monte Carlo (MC) modeling. Accurate modeling requires knowing the size of the electron spot, one of the few parameters to tune in MC models. The resolution of integrated megavoltage imaging systems, such as the tomotherapy system, strongly depends on the photon spot size which is closely related to the electron spot. The aim of this article is to clarify the relationship between the electron spot size and the photon spot size (i.e., the focal spot size) for typical incident electron beam energies and target thicknesses. Methods: Three electron energies (3, 5.5, and 18 MeV), four electron spot sizes (FWHM=0, 0.5, 1, and 1.5 mm), and two tungsten target thicknesses (0.15 and 1 cm) were considered. The formation of the photon beam within the target was analyzed through electron energy deposition with depth, as well as photon production at several phase-space planes placed perpendicular to the beam axis, where only photons recorded for the first time were accounted for. Photon production was considered for ''newborn'' photons intersecting a 45x45 cm 2 plane at the isocenter (85 cm from source). Finally, virtual source position and ''effective'' focal spot size were computed by backprojecting all the photons from the bottom of the target intersecting a 45x45 cm 2 plane. The virtual source position and focal spot size were estimated at the plane position where the latter is minimal. Results: In the relevant case of considering only photons intersecting the 45x45 cm 2 plane, the results unambiguously showed that the effective photon spot is created within the first 0.25 mm of the target and that electron and focal spots may be assumed to be equal within 3-4%. Conclusions: In a good approximation photon spot size equals electron spot size for high energy X-ray treatments delivered by linear accelerators.

  9. Forecasting European thermal coal spot prices

    Directory of Open Access Journals (Sweden)

    Alicja Krzemień

    2015-01-01

    Finally, in order to analyse the time series model performance a Generalized Regression Neural Network (GRNN was used and its performance compared against the whole AR(2 process. Empirical results obtained confirmed that there is no statistically significant difference between both methods. The GRNN analysis also allowed pointing out the main drivers that move the European Thermal Coal Spot prices: crude oil, USD/CNY change and supply side drivers.

  10. Design of a cost-effective laser spot tracker

    Science.gov (United States)

    Artan, Göktuǧ Gencehan; Sari, Hüseyin

    2017-05-01

    One of the most important aspects of guided systems is detection. The most convenient detection in the sense of precision can be achieved with a laser spot tracker. This study deals with a military grade, high performance and cost-effective laser spot tracker for a guided system. The aim is to develop a high field of view system that will detect a laser spot from a distance of 3 kilometers in which the target is designated from 3 kilometers with a laser. The study basically consists of the system design, modeling, producing and the conducting performance tests of the whole system.

  11. Event review: 1st Annual Outdoors Without Limits (OWL knap-in, Comer, Georgia, U.S.A.

    Directory of Open Access Journals (Sweden)

    Michael James Miller

    2014-09-01

    Full Text Available In June of 2014, Outdoors Without Limits (OWL, a national non-profit organization that promotes awareness and teamwork between disabled and non-disabled individuals, sponsored their first knap-in and primitive skills gathering.

  12. Research and in situ conservation of owl monkeys enhances environmental law enforcement at the Colombian-Peruvian border

    OpenAIRE

    Maldonado, Angela M; Peck, Mika R

    2014-01-01

    This study reports on impacts of illegal trade in owl monkeys (Aotus nancymaae, A. vociferans) for the biomedical research market in the Colombian-Peruvian Amazonian border. Through freedom of information requests and interviews with hunters we found that 912 owl monkeys, including A. nancymaae captured in Peru, were trapped over a 3-month period in 2012 to supply a malaria research facility based in Leticia, Colombia, which had trapping permits for the use of only 800 A. vociferans annually ...

  13. Damage tolerance reliability analysis of automotive spot-welded joints

    International Nuclear Information System (INIS)

    Mahadevan, Sankaran; Ni Kan

    2003-01-01

    This paper develops a damage tolerance reliability analysis methodology for automotive spot-welded joints under multi-axial and variable amplitude loading history. The total fatigue life of a spot weld is divided into two parts, crack initiation and crack propagation. The multi-axial loading history is obtained from transient response finite element analysis of a vehicle model. A three-dimensional finite element model of a simplified joint with four spot welds is developed for static stress/strain analysis. A probabilistic Miner's rule is combined with a randomized strain-life curve family and the stress/strain analysis result to develop a strain-based probabilistic fatigue crack initiation life prediction for spot welds. Afterwards, the fatigue crack inside the base material sheet is modeled as a surface crack. Then a probabilistic crack growth model is combined with the stress analysis result to develop a probabilistic fatigue crack growth life prediction for spot welds. Both methods are implemented with MSC/NASTRAN and MSC/FATIGUE software, and are useful for reliability assessment of automotive spot-welded joints against fatigue and fracture

  14. Great gray owls (Strix nebulosa) in Yosemite National Park: on the importance of food, forest structure, and human disturbance

    Science.gov (United States)

    van Riper, Charles; Fontaine, Joseph J.; van Wagtendonk, Jan W.

    2013-01-01

    We studied great gray owls (Strix nebulosa Forster) in Yosemite National Park, California, measuring variables that could potentially influence patterns of occurrence and conservation of this stateendangered species. We found that owl presence was closely tied to habitat (red fir (Abies magnified A. Murray) and the abundance of meadows), prey, and snags across the landscape. We also found that indicators of human recreational activities negatively influenced owl distribution and habitat use. Great gray owls appear to prefer mid-elevation red fir forest with meadows that are drier and more productive in terms of small mammal populations. That these areas also have the highest human activity presents a paradox, both for individual owls and for the future conservation and management of this California endangered species. The extent to which human recreation in natural areas affects animal behavior, species distribution, and productivity is a growing issue in natural area management. We present information that will allow land managers to better understand how existing natural resources, coupled with human recreation, influence the distribution and habitat use of the great gray owl.

  15. What do predators really want? The role of gerbil energetic state in determining prey choice by Barn Owls.

    Science.gov (United States)

    Embar, Keren; Mukherjee, Shomen; Kotler, Burt P

    2014-02-01

    In predator-prey foraging games, predators should respond to variations in prey state. The value of energy for the prey changes depending on season. Prey in a low energetic state and/or in a reproductive state should invest more in foraging and tolerate higher predation risk. This should make the prey more catchable, and thereby, more preferable to predators. We ask, can predators respond to prey state? How does season and state affect the foraging game from the predator's perspective? By letting owls choose between gerbils whose states we experimentally manipulated, we could demonstrate predator sensitivity to prey state and predator selectivity that otherwise may be obscured by the foraging game. During spring, owls invested more time and attacks in the patch with well-fed gerbils. During summer, owls attacked both patches equally, yet allocated more time to the patch with hungry gerbils. Energetic state per se does not seem to be the basis of owl choice. The owls strongly responded to these subtle differences. In summer, gerbils managed their behavior primarily for survival, and the owls equalized capture opportunities by attacking both patches equally.

  16. Seasonality in cocoa spot and forward markets: empirical evidence

    OpenAIRE

    Sarfo, S.; Geman, Hélyette

    2012-01-01

    This paper first describes the main features of supply and demand in cocoa spot markets. A state- variable model is proposed to describe the random evolution of cocoa forward curves over time, which essentially adapts to agricultural commodities, introduced by Borovkova and Geman (2006) for energy. In contrast to most of the literature on the subject, the first state variable is not the spot price, as it combines seasonal and stochastic features and may not be observable, instead, the average...

  17. Numerical optimisation in spot detector design

    NARCIS (Netherlands)

    van der Heijden, Ferdinand; Apperloo, W.; Spreeuwers, Lieuwe Jan

    1997-01-01

    Spots are image details resulting from objects, the projections of which are so small that the inner structure of these objects cannot be resolved from their image. Spot detectors are image operators aiming at the detection and localisation of spots in the image. Most spot detectors can be tuned

  18. 9 CFR 149.4 - Spot audit.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Spot audit. 149.4 Section 149.4... LIVESTOCK IMPROVEMENT VOLUNTARY TRICHINAE CERTIFICATION PROGRAM § 149.4 Spot audit. (a) In addition to regularly scheduled site audits, certified production sites will be subject to spot audits. (1) Random spot...

  19. On the origin of delta spots

    International Nuclear Information System (INIS)

    Tang, F.

    1983-01-01

    Mount Wilson sunspot drawings from 1966 through 1980 were used in conjunction with Hα filtergrams from Big Bear Solar Observatory to examine the origin of delta spots, spots with bipolar umbrae within one penumbra. Of the six cases we studied, five were formed by the union of non-paired spots. They are either shoved into one another by two neighboring growing bipoles or by a new spot born piggy-back style on an existing spot of opposite polarity. Proper motions of the growing spots take on curvilinear paths around one another to avoid a collision. This is the shear motion observed in delta spots (Tanaka, 1979). In the remaining case, the delta spot was formed by spots that emerged as a pair. Our findings indicate no intrinsic differences in the formation or the behavior between delta spots of normal magnetic configuration. (orig.)

  20. 40K, 137Cs, 90Sr, 238,239+240Pu and 241Am in mammals' skulls from owls' pellets and owl skeletons in Poland.

    Science.gov (United States)

    Gaca, Paweł; Mietelski, Jerzy W; Kitowski, Ignacy; Grabowska, Sylwia; Tomankiewicz, Ewa

    2005-01-01

    Skulls of small mammals belonging to two species of rodents and three species of insectivores collected in Eastern Poland were the subject of the present investigation. The skulls were separated from owl pellets. Activities of 40K, 137Cs, 90Sr, 238,239+240Pu and 241Am were determined by means of gamma spectrometry as well as liquid scintillation spectrometry or alpha spectrometry along with relevant radiochemical procedures. A detailed description of the procedures is provided. The research was supplied with the analysis of three skeletons of owls. No measurable difference between the skulls of rodents and insectivorous animals with regard to activity of any of the examined radionuclides was found. No accumulation effect in the owl skeletons was detected. Though measured activities of 137Cs and 40K for the skulls were of the same magnitude as those found previously for large wild herbivorous animals from typical locations in Poland, those for 90Sr were even lower than previously determined. A big difference was found for activities of plutonium and americium isotopes. Their mean activities were higher by an order of magnitude when compared to the examined previously values. The maximum 239+240Pu activity was equal to 97.5+/-7.7 mBq/kg, with 65% of it originating from global fallout. Relatively high content of transuranic elements found for rodents and insectivorous mammals seems to be unrelated to their feeding habits and should rather be attributed to the living conditions. It is suggested that small mammals, together with tiny soil particles present in mid-soil living tunnels, can inhale the transuranic elements.