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Sample records for inverse seasonal peak

  1. Validation of inverse seasonal peak mortality in medieval plagues, including the Black Death, in comparison to modern Yersinia pestis-variant diseases.

    Science.gov (United States)

    Welford, Mark R; Bossak, Brian H

    2009-12-22

    Recent studies have noted myriad qualitative and quantitative inconsistencies between the medieval Black Death (and subsequent "plagues") and modern empirical Y. pestis plague data, most of which is derived from the Indian and Chinese plague outbreaks of A.D. 1900+/-15 years. Previous works have noted apparent differences in seasonal mortality peaks during Black Death outbreaks versus peaks of bubonic and pneumonic plagues attributed to Y. pestis infection, but have not provided spatiotemporal statistical support. Our objective here was to validate individual observations of this seasonal discrepancy in peak mortality between historical epidemics and modern empirical data. We compiled and aggregated multiple daily, weekly and monthly datasets of both Y. pestis plague epidemics and suspected Black Death epidemics to compare seasonal differences in mortality peaks at a monthly resolution. Statistical and time series analyses of the epidemic data indicate that a seasonal inversion in peak mortality does exist between known Y. pestis plague and suspected Black Death epidemics. We provide possible explanations for this seasonal inversion. These results add further evidence of inconsistency between historical plagues, including the Black Death, and our current understanding of Y. pestis-variant disease. We expect that the line of inquiry into the disputed cause of the greatest recorded epidemic will continue to intensify. Given the rapid pace of environmental change in the modern world, it is crucial that we understand past lethal outbreaks as fully as possible in order to prepare for future deadly pandemics.

  2. Validation of inverse seasonal peak mortality in medieval plagues, including the Black Death, in comparison to modern Yersinia pestis-variant diseases.

    Directory of Open Access Journals (Sweden)

    Mark R Welford

    Full Text Available BACKGROUND: Recent studies have noted myriad qualitative and quantitative inconsistencies between the medieval Black Death (and subsequent "plagues" and modern empirical Y. pestis plague data, most of which is derived from the Indian and Chinese plague outbreaks of A.D. 1900+/-15 years. Previous works have noted apparent differences in seasonal mortality peaks during Black Death outbreaks versus peaks of bubonic and pneumonic plagues attributed to Y. pestis infection, but have not provided spatiotemporal statistical support. Our objective here was to validate individual observations of this seasonal discrepancy in peak mortality between historical epidemics and modern empirical data. METHODOLOGY/PRINCIPAL FINDINGS: We compiled and aggregated multiple daily, weekly and monthly datasets of both Y. pestis plague epidemics and suspected Black Death epidemics to compare seasonal differences in mortality peaks at a monthly resolution. Statistical and time series analyses of the epidemic data indicate that a seasonal inversion in peak mortality does exist between known Y. pestis plague and suspected Black Death epidemics. We provide possible explanations for this seasonal inversion. CONCLUSIONS/SIGNIFICANCE: These results add further evidence of inconsistency between historical plagues, including the Black Death, and our current understanding of Y. pestis-variant disease. We expect that the line of inquiry into the disputed cause of the greatest recorded epidemic will continue to intensify. Given the rapid pace of environmental change in the modern world, it is crucial that we understand past lethal outbreaks as fully as possible in order to prepare for future deadly pandemics.

  3. Forecasting Cool Season Daily Peak Winds at Kennedy Space Center and Cape Canaveral Air Force Station

    Science.gov (United States)

    Barrett, Joe, III; Short, David; Roeder, William

    2008-01-01

    The expected peak wind speed for the day is an important element in the daily 24-Hour and Weekly Planning Forecasts issued by the 45th Weather Squadron (45 WS) for planning operations at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The morning outlook for peak speeds also begins the warning decision process for gusts ^ 35 kt, ^ 50 kt, and ^ 60 kt from the surface to 300 ft. The 45 WS forecasters have indicated that peak wind speeds are a challenging parameter to forecast during the cool season (October-April). The 45 WS requested that the Applied Meteorology Unit (AMU) develop a tool to help them forecast the speed and timing of the daily peak and average wind, from the surface to 300 ft on KSC/CCAFS during the cool season. The tool must only use data available by 1200 UTC to support the issue time of the Planning Forecasts. Based on observations from the KSC/CCAFS wind tower network, surface observations from the Shuttle Landing Facility (SLF), and CCAFS upper-air soundings from the cool season months of October 2002 to February 2007, the AMU created multiple linear regression equations to predict the timing and speed of the daily peak wind speed, as well as the background average wind speed. Several possible predictors were evaluated, including persistence, the temperature inversion depth, strength, and wind speed at the top of the inversion, wind gust factor (ratio of peak wind speed to average wind speed), synoptic weather pattern, occurrence of precipitation at the SLF, and strongest wind in the lowest 3000 ft, 4000 ft, or 5000 ft. Six synoptic patterns were identified: 1) surface high near or over FL, 2) surface high north or east of FL, 3) surface high south or west of FL, 4) surface front approaching FL, 5) surface front across central FL, and 6) surface front across south FL. The following six predictors were selected: 1) inversion depth, 2) inversion strength, 3) wind gust factor, 4) synoptic weather pattern, 5) occurrence of

  4. Four Weeks of Off-Season Training Improves Peak Oxygen Consumption in Female Field Hockey Players

    OpenAIRE

    Lindsey T. Funch; Erik Lind; Larissa True; Deborah Van Langen; John T. Foley; James F. Hokanson

    2017-01-01

    The purpose of the study was to examine the changes in peak oxygen consumption ( V ˙O2peak) and running economy (RE) following four-weeks of high intensity training and concurrent strength and conditioning during the off-season in collegiate female field hockey players. Fourteen female student-athletes (age 19.29 ± 0.91 years) were divided into two training groups, matched from baseline V ˙O2peak: High Intensity Training (HITrun; n = 8) and High Intensity Interval Training (HIIT; ...

  5. Seasonal variations in house dust mite influence the circadian peak expiratory flow amplitude

    NARCIS (Netherlands)

    Postma, DS; vanderHeide, S; deReus, DM; Koeter, GH; vanAalderen, WMC; Meijer, G.

    1996-01-01

    The aim of the study was to investigate whether seasonal differences in house dust mite (HDM) allergen exposure influence the circadian peak expiratory flow (PEF) amplitude in asthmatic children. Asthmatic children (n = 25) with a solitary allergy to HDM were studied in spring and in autumn. All

  6. Shifts of growing-season precipitation peaks decrease soil respiration in a semiarid grassland.

    Science.gov (United States)

    Ru, Jingyi; Zhou, Yaqiong; Hui, Dafeng; Zheng, Mengmei; Wan, Shiqiang

    2018-03-01

    Changing precipitation regimes could have profound influences on carbon (C) cycle in the biosphere. However, how soil C release from terrestrial ecosystems responds to changing seasonal distribution of precipitation remains unclear. A field experiment was conducted for 4 years (2013-2016) to examine the effects of altered precipitation distributions in the growing season on soil respiration in a temperate steppe in the Mongolian Plateau. Over the 4 years, both advanced and delayed precipitation peaks suppressed soil respiration, and the reductions mainly occurred in August. The decreased soil respiration could be primarily attributable to water stress and subsequently limited plant growth (community cover and belowground net primary productivity) and soil microbial activities in the middle growing season, suggesting that precipitation amount in the middle growing season is more important than that in the early, late, or whole growing seasons in regulating soil C release in grasslands. The observations of the additive effects of advanced and delayed precipitation peaks indicate semiarid grasslands will release less C through soil respiratory processes under the projected seasonal redistribution of precipitation in the future. Our findings highlight the potential role of intra-annual redistribution of precipitation in regulating ecosystem C cycling in arid and semiarid regions. © 2017 John Wiley & Sons Ltd.

  7. Peak season plant activity shift towards spring is reflected by increasing carbon uptake by extratropical ecosystems.

    Science.gov (United States)

    Gonsamo, Alemu; Chen, Jing M; Ooi, Ying W

    2018-05-01

    Climate change is lengthening the growing season of the Northern Hemisphere extratropical terrestrial ecosystems, but little is known regarding the timing and dynamics of the peak season of plant activity. Here, we use 34-year satellite normalized difference vegetation index (NDVI) observations and atmospheric CO 2 concentration and δ 13 C isotope measurements at Point Barrow (Alaska, USA, 71°N) to study the dynamics of the peak of season (POS) of plant activity. Averaged across extratropical (>23°N) non-evergreen-dominated pixels, NDVI data show that the POS has advanced by 1.2 ± 0.6 days per decade in response to the spring-ward shifts of the start (1.0 ± 0.8 days per decade) and end (1.5 ± 1.0 days per decade) of peak activity, and the earlier onset of the start of growing season (1.4 ± 0.8 days per decade), while POS maximum NDVI value increased by 7.8 ± 1.8% for 1982-2015. Similarly, the peak day of carbon uptake, based on calculations from atmospheric CO 2 concentration and δ 13 C data, is advancing by 2.5 ± 2.6 and 4.3 ± 2.9 days per decade, respectively. POS maximum NDVI value shows strong negative relationships (p POS days. Given that the maximum solar irradiance and day length occur before the average POS day, the earlier occurrence of peak plant activity results in increased plant productivity. Both the advancing POS day and increasing POS vegetation greenness are consistent with the shifting peak productivity towards spring and the increasing annual maximum values of gross and net ecosystem productivity simulated by coupled Earth system models. Our results further indicate that the decline in autumn NDVI is contributing the most to the overall browning of the northern high latitudes (>50°N) since 2011. The spring-ward shift of peak season plant activity is expected to disrupt the synchrony of biotic interaction and exert strong biophysical feedbacks on climate by modifying the surface albedo and energy budget. © 2017

  8. Four Weeks of Off-Season Training Improves Peak Oxygen Consumption in Female Field Hockey Players

    Directory of Open Access Journals (Sweden)

    Lindsey T. Funch

    2017-11-01

    Full Text Available The purpose of the study was to examine the changes in peak oxygen consumption ( V ˙O2peak and running economy (RE following four-weeks of high intensity training and concurrent strength and conditioning during the off-season in collegiate female field hockey players. Fourteen female student-athletes (age 19.29 ± 0.91 years were divided into two training groups, matched from baseline V ˙O2peak: High Intensity Training (HITrun; n = 8 and High Intensity Interval Training (HIIT; n = 6. Participants completed 12 training sessions. HITrun consisted of 30 min of high-intensity running, while HIIT consisted of a series of whole-body high intensity Tabata-style intervals (75–85% of age predicted maximum heart rate for a total of four minutes. In addition to the interval training, the off-season training included six resistance training sessions, three team practices, and concluded with a team scrimmage. V ˙O2peak was measured pre- and post-training to determine the effectiveness of the training program. A two-way mixed (group × time ANOVA showed a main effect of time with a statistically significant difference in V ˙O2peak from pre- to post-testing, F(1, 12 = 12.657, p = 0.004, partial η2 = 0.041. Average (±SD V ˙O2peak increased from 44.64 ± 3.74 to 47.35 ± 3.16 mL·kg−1·min−1 for HIIT group and increased from 45.39 ± 2.80 to 48.22 ± 2.42 mL·kg−1·min−1 for HITrun group. Given the similar improvement in aerobic power, coaches and training staff may find the time saving element of HIIT-type conditioning programs attractive.

  9. Linear relationship between peak and season-long abundances in insects.

    Directory of Open Access Journals (Sweden)

    Ksenia S Onufrieva

    Full Text Available An accurate quantitative relationship between key characteristics of an insect population, such as season-long and peak abundances, can be very useful in pest management programs. To the best of our knowledge, no such relationship has yet been established. Here we establish a predictive linear relationship between insect catch Mpw during the week of peak abundance, the length of seasonal flight period, F (number of weeks and season-long cumulative catch (abundance A = 0.41MpwF. The derivation of the equation is based on several general assumptions and does not involve fitting to experimental data, which implies generality of the result. A quantitative criterion for the validity of the model is presented. The equation was tested using extensive data collected on captures of male gypsy moths Lymantria dispar (L. (Lepidoptera: Erebidae in pheromone-baited traps during 15 years. The model was also tested using trap catch data for two species of mosquitoes, Culex pipiens (L. (Diptera: Culicidae and Aedes albopictus (Skuse (Diptera: Culicidae, in Gravid and BG-sentinel mosquito traps, respectively. The simple, parameter-free equation approximates experimental data points with relative error of 13% and R2 = 0.997, across all of the species tested. For gypsy moth, we also related season-long and weekly trap catches to the daily trap catches during peak flight. We describe several usage scenarios, in which the derived relationships are employed to help link results of small-scale field studies to the operational pest management programs.

  10. Tool for Forecasting Cool-Season Peak Winds Across Kennedy Space Center and Cape Canaveral Air Force Station

    Science.gov (United States)

    Barrett, Joe H., III; Roeder, William P.

    2010-01-01

    The expected peak wind speed for the day is an important element in the daily morning forecast for ground and space launch operations at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The 45th Weather Squadron (45 WS) must issue forecast advisories for KSC/CCAFS when they expect peak gusts for >= 25, >= 35, and >= 50 kt thresholds at any level from the surface to 300 ft. In Phase I of this task, the 45 WS tasked the Applied Meteorology Unit (AMU) to develop a cool-season (October - April) tool to help forecast the non-convective peak wind from the surface to 300 ft at KSC/CCAFS. During the warm season, these wind speeds are rarely exceeded except during convective winds or under the influence of tropical cyclones, for which other techniques are already in use. The tool used single and multiple linear regression equations to predict the peak wind from the morning sounding. The forecaster manually entered several observed sounding parameters into a Microsoft Excel graphical user interface (GUI), and then the tool displayed the forecast peak wind speed, average wind speed at the time of the peak wind, the timing of the peak wind and the probability the peak wind will meet or exceed 35, 50 and 60 kt. The 45 WS customers later dropped the requirement for >= 60 kt wind warnings. During Phase II of this task, the AMU expanded the period of record (POR) by six years to increase the number of observations used to create the forecast equations. A large number of possible predictors were evaluated from archived soundings, including inversion depth and strength, low-level wind shear, mixing height, temperature lapse rate and winds from the surface to 3000 ft. Each day in the POR was stratified in a number of ways, such as by low-level wind direction, synoptic weather pattern, precipitation and Bulk Richardson number. The most accurate Phase II equations were then selected for an independent verification. The Phase I and II forecast methods were

  11. Magnitudes and timing of seasonal peak snowpack water equivalents in Arizona: A preliminary study of the possible effects of recent climatic change

    Science.gov (United States)

    Peter F. Ffolliott; Gerald J. Gottfried

    2010-01-01

    Field measurements and computer-based predictions suggest that the magnitudes of seasonal peak snowpack water equivalents are becoming less and the timing of these peaks is occurring earlier in the snowmelt-runoff season of the western United States. These changes in peak snowpack conditions have often been attributed to a warming of the regional climate. To determine...

  12. Seasonal spring peaks of suicide in victims with and without prior history of hospitalization for mood disorders.

    Science.gov (United States)

    Postolache, Teodor T; Mortensen, Preben B; Tonelli, Leonardo H; Jiao, Xiaolong; Frangakis, Constantin; Soriano, Joseph J; Qin, Ping

    2010-02-01

    Seasonal spring peaks of suicide are highly replicated, but their origin is poorly understood. As the peak of suicide in spring could be a consequence of decompensation of mood disorders in spring, we hypothesized that prior history of mood disorders is predictively associated with suicide in spring. We analyzed the monthly rates of suicide based upon all 37,987 suicide cases in the Danish Cause of Death Registry from 1970 to 2001. History of mood disorder was obtained from the Danish Psychiatric Central Register and socioeconomical data from the Integrated Database for Labour Market Research. The monthly rate ratio of suicide relative to December was estimated using a Poisson regression. Seasonality of suicide between individuals with versus without hospitalization for mood disorders was compared using conditional logistic regression analyses with adjustment for income, marital status, place of residence, and method of suicide. A statistically significant spring peak in suicide was observed in both groups. A history of mood disorders was associated with an increased risk of suicide in spring (for males: RR=1.18, 95% CI 1.07-1.31; for females: RR=1.20, 95% CI 1.10-1.32). History of axis II disorders was not analyzed. Danish socioeconomical realities have only limited generalizability. The results support the need to further investigate if exacerbation of mood disorders in spring triggers seasonal peaks of suicide. Identifying triggers for seasonal spring peaks in suicide may lead to uncovering novel risk factors and therapeutic targets for suicide prevention. 2009 Elsevier B.V. All rights reserved.

  13. Regional Atmospheric CO2 Inversion Reveals Seasonal and Geographic Differences in Amazon Net Biome Exchange

    Science.gov (United States)

    Alden, Caroline B.; Miller, John B.; Gatti, Luciana V.; Gloor, Manuel M.; Guan, Kaiyu; Michalak, Anna M.; van der Laan-Luijkx, Ingrid; Touma, Danielle; Andrews, Arlyn; Basso, Luana G.; hide

    2016-01-01

    Understanding tropical rainforest carbon exchange and its response to heat and drought is critical for quantifying the effects of climate change on tropical ecosystems, including global climate carbon feedbacks. Of particular importance for the global carbon budget is net biome exchange of CO2 with the atmosphere (NBE), which represents nonfire carbon fluxes into and out of biomass and soils. Subannual and sub-Basin Amazon NBE estimates have relied heavily on process-based biosphere models, despite lack of model agreement with plot-scale observations. We present a new analysis of airborne measurements that reveals monthly, regional-scale (Approx.1-8 x 10(exp -6) km2) NBE variations. We develop a regional atmospheric CO2 inversion that provides the first analysis of geographic and temporal variability in Amazon biosphere-atmosphere carbon exchange and that is minimally influenced by biosphere model-based first guesses of seasonal and annual mean fluxes. We find little evidence for a clear seasonal cycle in Amazon NBE but do find NBE sensitivity to aberrations from long-term mean climate. In particular, we observe increased NBE (more carbon emitted to the atmosphere) associated with heat and drought in 2010, and correlations between wet season NBE and precipitation (negative correlation) and temperature (positive correlation). In the eastern Amazon, pulses of increased NBE persisted through 2011, suggesting legacy effects of 2010 heat and drought. We also identify regional differences in postdrought NBE that appear related to long-term water availability. We examine satellite proxies and find evidence for higher gross primary productivity (GPP) during a pulse of increased carbon uptake in 2011, and lower GPP during a period of increased NBE in the 2010 dry season drought, but links between GPP and NBE changes are not conclusive. These results provide novel evidence of NBE sensitivity to short-term temperature and moisture extremes in the Amazon, where monthly and sub

  14. Inversions

    Science.gov (United States)

    Brown, Malcolm

    2009-01-01

    Inversions are fascinating phenomena. They are reversals of the normal or expected order. They occur across a wide variety of contexts. What do inversions have to do with learning spaces? The author suggests that they are a useful metaphor for the process that is unfolding in higher education with respect to education. On the basis of…

  15. Attribution of Large-Scale Climate Patterns to Seasonal Peak-Flow and Prospects for Prediction Globally

    Science.gov (United States)

    Lee, Donghoon; Ward, Philip; Block, Paul

    2018-02-01

    Flood-related fatalities and impacts on society surpass those from all other natural disasters globally. While the inclusion of large-scale climate drivers in streamflow (or high-flow) prediction has been widely studied, an explicit link to global-scale long-lead prediction is lacking, which can lead to an improved understanding of potential flood propensity. Here we attribute seasonal peak-flow to large-scale climate patterns, including the El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), and Atlantic Multidecadal Oscillation (AMO), using streamflow station observations and simulations from PCR-GLOBWB, a global-scale hydrologic model. Statistically significantly correlated climate patterns and streamflow autocorrelation are subsequently applied as predictors to build a global-scale season-ahead prediction model, with prediction performance evaluated by the mean squared error skill score (MSESS) and the categorical Gerrity skill score (GSS). Globally, fair-to-good prediction skill (20% ≤ MSESS and 0.2 ≤ GSS) is evident for a number of locations (28% of stations and 29% of land area), most notably in data-poor regions (e.g., West and Central Africa). The persistence of such relevant climate patterns can improve understanding of the propensity for floods at the seasonal scale. The prediction approach developed here lays the groundwork for further improving local-scale seasonal peak-flow prediction by identifying relevant global-scale climate patterns. This is especially attractive for regions with limited observations and or little capacity to develop flood early warning systems.

  16. The phase differences of the interdecadal variabilities of tropical cyclone activity in the peak and late seasons over the western North Pacific

    Science.gov (United States)

    Fan, Tingting; Xu, Shibin; Huang, Fei; Zhao, Jinping

    2018-04-01

    This study compares the interdecadal variations in tropical cyclone (TC) activities over the western North Pacific (WNP) basin during the peak season (July-September) and late season (October-December) of 1955-2014 and explores the possible physical mechanisms behind the variations. Both the peak- and late-season tropical storm (TS) days show distinct interdecadal variations, while the late-season TS days lead the peak-season TS days by approximately 4 years on an interdecadal time scale. The late-season TC activity is related to the east-west sea surface temperature (SST) gradient across the equatorial Pacific. The westerly winds induced by the SST gradient can reduce the vertical wind shear and increase the low-level vorticity, which favors TC genesis over the TC genesis region. The peak-season TC activity appears to relate to the SST gradient between the Indian Ocean and the Central Pacific. The westerly wind induced by the SST gradient can reduce the vertical wind shear and increase the mid-level relative humidity, thereby enhancing the TC activity. The full picture of the interdecadal variation in the WNP TC activity during the peak and late seasons revealed in this study provides a new perspective on the seasonal TC forecasts and future projections.

  17. Tool for Forecasting Cool-Season Peak Winds Across Kennedy Space Center and Cape Canaveral Air Force Station (CCAFS)

    Science.gov (United States)

    Barrett, Joe H., III; Roeder, William P.

    2010-01-01

    Peak wind speed is important element in 24-Hour and Weekly Planning Forecasts issued by 45th Weather Squadron (45 WS). Forecasts issued for planning operations at KSC/CCAFS. 45 WS wind advisories issued for wind gusts greater than or equal to 25 kt. 35 kt and 50 kt from surface to 300 ft. AMU developed cool-season (Oct - Apr) tool to help 45 WS forecast: daily peak wind speed, 5-minute average speed at time of peak wind, and probability peak speed greater than or equal to 25 kt, 35 kt, 50 kt. AMU tool also forecasts daily average wind speed from 30 ft to 60 ft. Phase I and II tools delivered as a Microsoft Excel graphical user interface (GUI). Phase II tool also delivered as Meteorological Interactive Data Display System (MIDDS) GUI. Phase I and II forecast methods were compared to climatology, 45 WS wind advisories and North American Mesoscale model (MesoNAM) forecasts in a verification data set.

  18. Satellite Phenology Observations Inform Peak Season of Allergenic Grass Pollen Aerobiology across Two Continents

    Science.gov (United States)

    Huete, A. R.; Devadas, R.; Davies, J.

    2015-12-01

    Pollen exposure and prevalence of allergenic diseases have increased in many parts of the world during the last 30 years, with exposure to aeroallergen grass pollen expected to intensify with climate change, raising increased concerns for allergic diseases. The primary contributing factors to higher allergenic plant species presence are thought to be climate change, land conversion, and biotic mixing of species. Conventional methods for monitoring airborne pollen are hampered by a lack of sampling sites and heavily rely on meteorology with less attention to land cover updates and monitoring of key allergenic species phenology stages. Satellite remote sensing offers an alternative method to overcome the restrictive coverage afforded by in situ pollen networks by virtue of its synoptic coverage and repeatability of measurements that enable timely updates of land cover and land use information and monitoring landscape dynamics and interactions with human activity and climate. In this study, we assessed the potential of satellite observations of urban/peri-urban environments to directly inform landscape conditions conducive to pollen emissions. We found satellite measurements of grass cover phenological evolution to be highly correlated with in situ aerobiological grass pollen concentrations in five urban centres located across two hemispheres (Australia and France). Satellite greenness data from the Moderate Resolution Imaging Spectroradiometer (MODIS) were found to be strongly synchronous with grass pollen aerobiology in both temperate grass dominated sites (France and Melbourne), as well as in Sydney, where multiple pollen peaks coincided with the presence of subtropical grasses. Employing general additive models (GAM), the satellite phenology data provided strong predictive capabilities to inform airborne pollen levels and forecast periods of grass pollen emissions at all five sites. Satellite phenology offer promising opportunities of improving public health risk

  19. Optimizing Photosynthetic and Respiratory Parameters Based on the Seasonal Variation Pattern in Regional Net Ecosystem Productivity Obtained from Atmospheric Inversion

    Science.gov (United States)

    Chen, Z.; Chen, J.; Zheng, X.; Jiang, F.; Zhang, S.; Ju, W.; Yuan, W.; Mo, G.

    2014-12-01

    In this study, we explore the feasibility of optimizing ecosystem photosynthetic and respiratory parameters from the seasonal variation pattern of the net carbon flux. An optimization scheme is proposed to estimate two key parameters (Vcmax and Q10) by exploiting the seasonal variation in the net ecosystem carbon flux retrieved by an atmospheric inversion system. This scheme is implemented to estimate Vcmax and Q10 of the Boreal Ecosystem Productivity Simulator (BEPS) to improve its NEP simulation in the Boreal North America (BNA) region. Simultaneously, in-situ NEE observations at six eddy covariance sites are used to evaluate the NEE simulations. The results show that the performance of the optimized BEPS is superior to that of the BEPS with the default parameter values. These results have the implication on using atmospheric CO2 data for optimizing ecosystem parameters through atmospheric inversion or data assimilation techniques.

  20. A modular approach to inverse modelling of a district heating facility with seasonal thermal energy storage

    DEFF Research Database (Denmark)

    Tordrup, Karl Woldum; Poulsen, Uffe Vestergaard; Nielsen, Carsten

    2017-01-01

    We use a modular approach to develop a TRNSYS model for a district heating facility by applying inverse modelling to one year of operational data for individual components. We assemble the components into a single TRNSYS model for the full system using the accumulation tanks as a central hub conn...

  1. Aerosol optical properties and radiative effects over Manora Peak in the Himalayan foothills: seasonal variability and role of transported aerosols

    International Nuclear Information System (INIS)

    Srivastava, A.K.; Ram, K.; Singh, Sachchidanand; Kumar, Sanjeev; Tiwari, S.

    2015-01-01

    The higher altitude regions of Himalayas and Tibetan Plateau are influenced by the dust and black carbon (BC) aerosols from the emissions and long-range transport from the adjoining areas. In this study, we present impacts of advection of polluted air masses of natural and anthropogenic emissions, on aerosol optical and radiative properties at Manora Peak (∼ 2000 m amsl) in central Himalaya over a period of more than two years (February 2006–May 2008). We used the most updated and comprehensive data of chemical and optical properties available in one of the most climatically sensitive region, the Himalaya, to estimate atmospheric radiative forcing and heating rate. Aerosol optical depth (AOD) was found to vary from 0.04 to 0.45 with significantly higher values in summer mainly due to an increase in mineral dust and biomass burning aerosols due to transport. In contrast, single scattering albedo (SSA) varied from 0.74 to 0.88 with relatively lower values during summer, suggesting an increase in absorbing BC and mineral dust aerosols. As a result, a large positive atmospheric radiative forcing (about 28 ± 5 Wm −2 ) and high values of corresponding heating rate (0.80 ± 0.14 Kday −1 ) has been found during summer. During the entire observation period, radiative forcing at the top of the atmosphere varied from − 2 to + 14 Wm −2 and from − 3 to − 50 Wm −2 at the surface whereas atmospheric forcing was in the range of 3 to 65 Wm −2 resulting in a heating rate of 0.1–1.8 Kday −1 . - Highlights: • Aerosol chemical and optical properties at Manora Peak, in central Himalaya, were significantly affected by dust and black carbon (BC) aerosols from the emissions and long-range transport from the adjoining areas. • Elevated AOD and lower SSA values were observed at Manora Peak during summer. • Enhancement in absorbing aerosols was observed during summer. • Large aerosol radiative forcing and heating rate was observed over the station in the

  2. Aerosol optical properties and radiative effects over Manora Peak in the Himalayan foothills: seasonal variability and role of transported aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, A.K. [Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi (India); Ram, K. [Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi (India); Singh, Sachchidanand, E-mail: ssingh@nplindia.org [Radio and Atmospheric Sciences Division, CSIR-National Physical Laboratory, New Delhi (India); Kumar, Sanjeev [Radio and Atmospheric Sciences Division, CSIR-National Physical Laboratory, New Delhi (India); Tiwari, S. [Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi (India)

    2015-01-01

    The higher altitude regions of Himalayas and Tibetan Plateau are influenced by the dust and black carbon (BC) aerosols from the emissions and long-range transport from the adjoining areas. In this study, we present impacts of advection of polluted air masses of natural and anthropogenic emissions, on aerosol optical and radiative properties at Manora Peak (∼ 2000 m amsl) in central Himalaya over a period of more than two years (February 2006–May 2008). We used the most updated and comprehensive data of chemical and optical properties available in one of the most climatically sensitive region, the Himalaya, to estimate atmospheric radiative forcing and heating rate. Aerosol optical depth (AOD) was found to vary from 0.04 to 0.45 with significantly higher values in summer mainly due to an increase in mineral dust and biomass burning aerosols due to transport. In contrast, single scattering albedo (SSA) varied from 0.74 to 0.88 with relatively lower values during summer, suggesting an increase in absorbing BC and mineral dust aerosols. As a result, a large positive atmospheric radiative forcing (about 28 ± 5 Wm{sup −2}) and high values of corresponding heating rate (0.80 ± 0.14 Kday{sup −1}) has been found during summer. During the entire observation period, radiative forcing at the top of the atmosphere varied from − 2 to + 14 Wm{sup −2} and from − 3 to − 50 Wm{sup −2} at the surface whereas atmospheric forcing was in the range of 3 to 65 Wm{sup −2} resulting in a heating rate of 0.1–1.8 Kday{sup −1}. - Highlights: • Aerosol chemical and optical properties at Manora Peak, in central Himalaya, were significantly affected by dust and black carbon (BC) aerosols from the emissions and long-range transport from the adjoining areas. • Elevated AOD and lower SSA values were observed at Manora Peak during summer. • Enhancement in absorbing aerosols was observed during summer. • Large aerosol radiative forcing and heating rate was observed

  3. Annual Survey of Horsehair Worm Cysts in Northern Taiwan, with Notes on a Single Seasonal Infection Peak in Chironomid Larvae (Diptera: Chironomidae).

    Science.gov (United States)

    Chiu, Ming-Chung; Huang, Chin-Gi; Wu, Wen-Jer; Shiao, Shiuh-Feng

    2016-06-01

    The life cycle of the freshwater horsehair worm typically includes a free-living phase (adult, egg, larva) and a multiple-host parasitic phase (aquatic paratenic host, terrestrial definitive host). Such a life cycle involving water and land can improve energy flow in riparian ecosystems; however, its temporal dynamics in nature have rarely been investigated. This study examined seasonal infection with cysts in larval Chironominae (Diptera: Chironomidae) in northern Taiwan. In the larval chironomids, cysts of 3 horsehair worm species were identified. The cysts of the dominant species were morphologically similar to those of Chordodes formosanus. Infection with these cysts increased suddenly and peaked 2 mo after the reproductive season of the adult horsehair worms. Although adult C. formosanus emerged several times in a year, only 1 distinct infection peak was detected in September in the chironomid larvae. Compared with the subfamily Chironominae, samples from the subfamilies Tanypodinae and Orthocladiinae were less parasitized. This indicates that the feeding behavior of the chironomid host likely affects horsehair worm cyst infections; however, bioconcentration in predatory chironomids was not detected.

  4. Use of post-thaw semen quality parameters to predict fertility of water buffalo (Bubalus bubalis) bull during peak breeding season.

    Science.gov (United States)

    Ahmed, H; Andrabi, S M H; Anwar, M; Jahan, S

    2017-05-01

    This study was designed to predict the fertility of water buffalo bull using post-thaw semen quality parameters during peak breeding season. Thirty ejaculates were collected from five bulls with artificial vagina and cryopreserved. At post-thaw, semen was analysed for motility parameters, velocity distribution, kinematics, DNA integrity/fragmentation, viability, mitochondrial transmembrane potential, morphology, plasma membrane and acrosome integrity. Data of 514 inseminations were collected for estimation of in vivo fertility. Pearson's correlation coefficients showed that progressive motility (PM), rapid velocity, average path velocity, straight line velocity, straightness, supravital plasma membrane integrity, viable spermatozoon with intact acrosome or with high mitochondrial activity were correlated with in vivo fertility (r = .81, p fertility was PM. However, combinations of semen quality parameters to predict fertility were better as compared to single parameter. In conclusion, fertility of buffalo bull can be predicted through some of the post-thaw in vitro semen quality tests during peak breeding season. © 2016 Blackwell Verlag GmbH.

  5. Late Noachian Icy Highlands climate model: Exploring the possibility of transient melting and fluvial/lacustrine activity through peak annual and seasonal temperatures

    Science.gov (United States)

    Palumbo, Ashley M.; Head, James W.; Wordsworth, Robin D.

    2018-01-01

    The nature of the Late Noachian climate of Mars remains one of the outstanding questions in the study of the evolution of martian geology and climate. Despite abundant evidence for flowing water (valley networks and open/closed basin lakes), climate models have had difficulties reproducing mean annual surface temperatures (MAT) > 273 K in order to generate the ;warm and wet; climate conditions presumed to be necessary to explain the observed fluvial and lacustrine features. Here, we consider a ;cold and icy; climate scenario, characterized by MAT ∼225 K and snow and ice distributed in the southern highlands, and ask: Does the formation of the fluvial and lacustrine features require continuous ;warm and wet; conditions, or could seasonal temperature variation in a ;cold and icy; climate produce sufficient summertime ice melting and surface runoff to account for the observed features? To address this question, we employ the 3D Laboratoire de Météorologie Dynamique global climate model (LMD GCM) for early Mars and (1) analyze peak annual temperature (PAT) maps to determine where on Mars temperatures exceed freezing in the summer season, (2) produce temperature time series at three valley network systems and compare the duration of the time during which temperatures exceed freezing with seasonal temperature variations in the Antarctic McMurdo Dry Valleys (MDV) where similar fluvial and lacustrine features are observed, and (3) perform a positive-degree-day analysis to determine the annual volume of meltwater produced through this mechanism, estimate the necessary duration that this process must repeat to produce sufficient meltwater for valley network formation, and estimate whether runoff rates predicted by this mechanism are comparable to those required to form the observed geomorphology of the valley networks. When considering an ambient CO2 atmosphere, characterized by MAT ∼225 K, we find that: (1) PAT can exceed the melting point of water (>273 K) in

  6. Blooming rhythms of cactus Cereus peruvianus with nocturnal peak at full moon during seasons of prolonged daytime photoperiod.

    Science.gov (United States)

    Ben-Attia, Mossadok; Reinberg, Alain; Smolensky, Michael H; Gadacha, Wafa; Khedaier, Achraf; Sani, Mamane; Touitou, Yvan; Boughamni, Néziha Ghanem

    2016-01-01

    Cereus peruvianus (Peruvian apple cactus) is a large erect and thorny succulent cactus characterized by column-like (cereus [L]: column), that is, candle-shaped, appendages. For three successive years (1100 days), between early April and late November, we studied the flowering patterns of eight cacti growing in public gardens and rural areas of north and central Tunisia, far from nighttime artificial illumination, in relation to natural environmental light, temperature, relative humidity and precipitation parameters. Flower blooming was assessed nightly between 23:00 h and until at least 02:00 h, and additionally around-the-clock at ~1 h intervals for 30 consecutive days during the late summer of each year of study to quantify both nyctohemeral (day-night) and lunar patterns. During the summer months of prolonged daytime photoperiod, flower blooming of C. peruvianus exhibited predictable-in-time variation as "waves" with average period of 29.5 days synchronized by the light of the full moon. The large-sized flower (~16 cm diameter) opens almost exclusively at night, between sunset and sunrise, as a 24 h rhythm during a specific 3-4-day span of the lunar cycle (full moon), with a strong correlation between moon phase and number and proportion of flowers in bloom (ranging from r = +0.59 to +0.91). Black, blue and red cotton sheets were used to filter specific spectral bands of nighttime moonlight from illuminating randomly selected plant appendages as a means to test the hypothesis of a "gating" 24 h rhythm phenomenon of photoreceptors at the bud level. Relative to control conditions (no light filtering), black sheet covering inhibited flower bud induction by 87.5%, red sheet covering by 46.6% and blue sheet covering by 34%, and the respective inhibiting effects on number of flowers in bloom were essentially 100%, ~81% and ~44%. C. peruvianus is a unique example of a terrestrial plant that exhibits a circadian flowering rhythm (peak ~00:00 h) "gated" by 24 h, lunar

  7. Malaria prevalence defined by microscopy, antigen detection, DNA amplification and total nucleic acid amplification in a malaria-endemic region during the peak malaria transmission season.

    Science.gov (United States)

    Waitumbi, John N; Gerlach, Jay; Afonina, Irina; Anyona, Samuel B; Koros, Joseph N; Siangla, Joram; Ankoudinova, Irina; Singhal, Mitra; Watts, Kate; Polhemus, Mark E; Vermeulen, Nicolaas M; Mahoney, Walt; Steele, Matt; Domingo, Gonzalo J

    2011-07-01

    To determine the malaria prevalence by microscopy, antigen detection and nucleic acid detection in a defined subpopulation in a Plasmodium falciparum-endemic region during the peak transmission season. Blood specimens were collected in a cross-sectional study involving children aged 5-10 years (n = 195) presenting with acute fever to two clinics in Western Kenya. All specimens underwent microscopy, HRP2 and aldolase antigen detection by enzyme immunoassay (EIA), parasite-specific DNA and total nucleic acid (RNA and DNA) by real-time PCR (qPCR) and reverse-transcriptase PCR (qRT-PCR). Microscopy detected 65/195 cases of malaria infection [95% confidence interval (CI) 52-78]. HRP2 and aldolase EIA had similar sensitivity levels detecting antigen in 65/195 (95% CI, 52-78) and 57/195 (95% CI, 45-70) cases. Discordants in antigen detection vs. microscopy occurred at Detection of total nucleic acid allowed a 3 log lower limit of detection than just DNA detection by real-time PCR in vitro. In clinical specimens, 114/195 (95% CI, 100-127) were qPCR positive (DNA), and 187/195 (95% CI, 179-191) were qRT-PCR positive (DNA plus RNA). The prevalence of submicroscopic malaria infection was significantly higher when detecting total nucleic acid than just DNA in this outpatient population during the high transmission season. Defining standards for submicroscopic infection will be important for control programmes, diagnostics development efforts and molecular epidemiology studies. © 2011 Blackwell Publishing Ltd.

  8. Spatial Patterns in Biogeochemical Processes During Peak Growing Season in Oiled and Unoiled Louisiana Salt Marshes: A Multi-Year Analysis

    Science.gov (United States)

    Chelsky, A.; Marton, J. M.; Bernhard, A. E.; Giblin, A. E.; Setta, S. P.; Hill, T. D.; Roberts, B. J.

    2016-02-01

    Louisiana salt marshes are important sites for carbon and nitrogen cycling because they can mitigate fluxes of nutrients and carbon to the Gulf of Mexico where a large hypoxic zone develops annually. The aim of this study was to investigate spatial and temporal patterns of biogeochemical processes in Louisiana coastal wetlands during peak growing season, and to investigate whether the Deepwater Horizon oil spill resulted in persistent changes to these rates. We measured nitrification potential and sediment characteristics at two pairs of oiled/unoiled marshes in three regions across the Louisiana coast (Terrebonne and east and west Barataria Bay) in July from 2012 to 2015, with plots along a gradient from the salt marsh edge to the interior. Rates of nitrification potential across the coast (overall mean of 901 ± 115 nmol gdw-1 d-1 from 2012-2014) were high compared to other published rates for salt marshes but displayed high variability at the plot level (4 orders of magnitude). Within each region interannual means varied by factors of 2-5. Nitrification potential did not differ with oiling history, but did display consistent spatial patterns within each region that corresponded to changes in relative elevation and inundation, which influence patterns of soil properties and microbial communities. In 2015, we also measured greenhouse gas (CO2, N2O and CH4) production and denitrification enzyme activity rates in addition to nitrification potential across the region to investigate spatial relationships between these processes.

  9. Acute effects of particulate matter and black carbon from seasonal fires on peak expiratory flow of schoolchildren in the Brazilian Amazon.

    Directory of Open Access Journals (Sweden)

    Ludmilla da Silva Viana Jacobson

    Full Text Available BACKGROUND: Panel studies have shown adverse effects of air pollution from biomass burning on children's health. This study estimated the effect of current levels of outdoor air pollution in the Amazonian dry season on peak expiratory flow (PEF. METHODS: A panel study with 234 schoolchildren from 6 to 15 years old living in the municipality of Tangará da Serra, Brazil was conducted. PEF was measured daily in the dry season in 2008. Mixed-effects models and unified modelling repeated for every child were applied. Time trends, temperature, humidity, and subject characteristics were regarded. Inhalable particulate matter (PM10, fine particulate matter (PM2.5, and black carbon (BC effects were evaluated based on 24-hour exposure lagged by 1 to 5 days and the averages of 2 or 3 days. Polynomial distributed lag models (PDLM were also applied. RESULTS: The analyses revealed reductions in PEF for PM10 and PM2.5 increases of 10 µg/m(3 and 1 µg/m(3 for BC. For PM10, the reductions varied from 0.15 (confidence interval (CI95%: -0.29; -0.01 to 0.25 l/min (CI95%: -0.40; -0.10. For PM2.5, they ranged from 0.46 (CI95%: -0.86 to -0.06 to 0.54 l/min (CI95%:-0.95; -0.14. As for BC, the reduction was approximately 1.40 l/min. In relation to PDLM, adverse effects were noticed in models based on the exposure on the current day through the previous 3 days (PDLM 0-3 and on the current day through the previous 5 days (PDLM 0-5, specially for PM10. For all children, for PDLM 0-5 the global effect was important for PM10, with PEF reduction of 0.31 l/min (CI95%: -0.56; -0.05. Also, reductions in lags 3 and 4 were observed. These associations were stronger for children between 6 and 8 years old. CONCLUSION: Reductions in PEF were associated with air pollution, mainly for lagged exposures of 3 to 5 days and for younger children.

  10. High Resolution Atmospheric Inversion of Urban CO2 Emissions During the Dormant Season of the Indianapolis Flux Experiment (INFLUX)

    Science.gov (United States)

    Lauvaux, Thomas; Miles, Natasha L.; Deng, Aijun; Richardson, Scott J.; Cambaliza, Maria O.; Davis, Kenneth J.; Gaudet, Brian; Gurney, Kevin R.; Huang, Jianhua; O'Keefe, Darragh; hide

    2016-01-01

    Urban emissions of greenhouse gases (GHG) represent more than 70% of the global fossil fuel GHG emissions. Unless mitigation strategies are successfully implemented, the increase in urban GHG emissions is almost inevitable as large metropolitan areas are projected to grow twice as fast as the world population in the coming 15 years. Monitoring these emissions becomes a critical need as their contribution to the global carbon budget increases rapidly. In this study, we developed the first comprehensive monitoring systems of CO2 emissions at high resolution using a dense network of CO2 atmospheric measurements over the city of Indianapolis. The inversion system was evaluated over a 8-month period and showed an increase compared to the Hestia CO2 emission estimate, a state-of-the-art building-level emission product, with a 20% increase in the total emissions over the area (from 4.5 to 5.7 Metric Megatons of Carbon +/- 0.23 Metric Megatons of Carbon). However, several key parameters of the inverse system need to be addressed to carefully characterize the spatial distribution of the emissions and the aggregated total emissions.We found that spatial structures in prior emission errors, mostly undetermined, affect significantly the spatial pattern in the inverse solution, as well as the carbon budget over the urban area. Several other parameters of the inversion were sufficiently constrained by additional observations such as the characterization of the GHG boundary inflow and the introduction of hourly transport model errors estimated from the meteorological assimilation system. Finally, we estimated the uncertainties associated with remaining systematic errors and undetermined parameters using an ensemble of inversions. The total CO2 emissions for the Indianapolis urban area based on the ensemble mean and quartiles are 5.26 - 5.91 Metric Megatons of Carbon, i.e. a statistically significant difference compared to the prior total emissions of 4.1 to 4.5 Metric Megatons of

  11. Space based inverse modeling of seasonal variations of anthropogenic and natural emissions of nitrogen oxides over China and effects of uncertainties in model meteorology and chemistry

    Science.gov (United States)

    Lin, J.

    2011-12-01

    Nitrogen oxides (NOx ≡ NO + NO2) are important atmospheric constituents affecting the tropospheric chemistry, surface air quality and climatic forcing. They are emitted both from anthropogenic and from natural (soil, lightning, biomass burning, etc.) sources, which can be estimated inversely from satellite remote sensing of the vertical column densities (VCDs) of nitrogen dioxide (NO2) in the troposphere. Based on VCDs of NO2 retrieved from OMI, a novel approach is developed in this study to separate anthropogenic emissions of NOx from natural sources over East China for 2006. It exploits the fact that anthropogenic and natural emissions vary with seasons with distinctive patterns. The global chemical transport model (CTM) GEOS-Chem is used to establish the relationship between VCDs of NO2 and emissions of NOx for individual sources. Derived soil emissions are compared to results from a newly developed bottom-up approach. Effects of uncertainties in model meteorology and chemistry over China, an important source of errors in the emission inversion, are evaluated systematically for the first time. Meteorological measurements from space and the ground are used to analyze errors in meteorological parameters driving the CTM.

  12. Influenza activity in Europe during eight seasons (1999–2007: an evaluation of the indicators used to measure activity and an assessment of the timing, length and course of peak activity (spread across Europe

    Directory of Open Access Journals (Sweden)

    Meijer Adam

    2007-11-01

    Full Text Available Abstract Background The European Influenza Surveillance Scheme (EISS has collected clinical and virological data on influenza since 1996 in an increasing number of countries. The EISS dataset was used to characterise important epidemiological features of influenza activity in Europe during eight winters (1999–2007. The following questions were addressed: 1 are the sentinel clinical reports a good measure of influenza activity? 2 how long is a typical influenza season in Europe? 3 is there a west-east and/or south-north course of peak activity ('spread' of influenza in Europe? Methods Influenza activity was measured by collecting data from sentinel general practitioners (GPs and reports by national reference laboratories. The sentinel reports were first evaluated by comparing them to the laboratory reports and were then used to assess the timing and spread of influenza activity across Europe during eight seasons. Results We found a good match between the clinical sentinel data and laboratory reports of influenza collected by sentinel physicians (overall match of 72% for +/- 1 week difference. We also found a moderate to good match between the clinical sentinel data and laboratory reports of influenza from non-sentinel sources (overall match of 60% for +/- 1 week. There were no statistically significant differences between countries using ILI (influenza-like illness or ARI (acute respiratory disease as case definition. When looking at the peak-weeks of clinical activity, the average length of an influenza season in Europe was 15.6 weeks (median 15 weeks; range 12–19 weeks. Plotting the peak weeks of clinical influenza activity reported by sentinel GPs against the longitude or latitude of each country indicated that there was a west-east spread of peak activity (spread of influenza across Europe in four winters (2001–2002, 2002–2003, 2003–2004 and 2004–2005 and a south-north spread in three winters (2001–2002, 2004–2005 and 2006

  13. Do seasonal changes in light availability influence the inverse leafing phenology of the neotropical dry forest understory shrub Bonellia nervosa (Theophrastaceae?

    Directory of Open Access Journals (Sweden)

    Oscar M Chaves

    2008-03-01

    Full Text Available In tropical dry forests most plants are deciduous during the dry season and flush leaves with the onset of the rains. In Costa Rica, the only species displaying the opposite pattern is Bonellia nervosa. To determine if seasonal changes in light availability are associated with the leaf and reproductive phenology of this species, we monitored leaf production, survival, and life span, as well as flower and fruit production from April 2000 to October 2001 in Santa Rosa National Park. Leaf flushing and flower bud production took place shortly after the autumnal equinox when day length starts to decrease. Leaves began expansion at the end of the wet season, and plants reached 70 % of their maximum leaf area at the beginning of the dry season, maintaining their foliage throughout the entire dry period. Leaf shedding occurred gradually during the first three months of the wet season. Leaf flushing and shedding showed high synchrony, with leaf numbers being related to light availability. Maximum leaf production coincided with peaks in radiation during the middle of the dry season. Decreasing day length induces highly synchronous flower bud emergence in dry forest species, but this is the first study indicating induction of leaf flushing by declining day length. Rev. Biol. Trop. 56 (1: 257-268. Epub 2008 March 31.En los bosques tropicales secos la mayoría de las plantas pierden sus hojas durante la estación seca y las producen con el inicio de las lluvias. En Costa Rica la única especie que muestra el patrón fenológico inverso es Bonellia nervosa. Para determinar si los cambios estacionales en la disponibilidad de luz estaban asociados con la fenología foliar y reproductiva en esta especie, monitoreamos la producción y sobrevivencia de hojas, así como la producción de flores y frutos de abril del 2000 a octubre del 2001 en el Parque Nacional Santa Rosa. La producción de hojas y botones florales ocurrió poco después del equinoccio de oto

  14. Changes in Allergy Symptoms and Depression Scores Are Positively Correlated In Patients With Recurrent Mood Disorders Exposed to Seasonal Peaks in Aeroallergens

    Directory of Open Access Journals (Sweden)

    Teodor T. Postolache

    2007-01-01

    Full Text Available Although growing evidence supports an association between allergy, allergens and depression, it remains unknown if this relationship is between “states” (possible triggers or “traits” (possible vulnerabilities. We hypothesized that patients with recurrent mood disorders who are sensitized to tree pollen (as determined by allergen specific IgE antibodies, in comparison to those who are not sensitized, would report larger negative changes in mood during exposure to tree pollen in spring. We also hypothesized that differences between high and low tree pollen periods in self reported allergy symptoms would correlate positively with differences in self reported depression scores. We present 1-year preliminary data on the first 51 patients with unipolar or bipolar disorder (age: 19-63 years, 65% female, twelve patients were tree-pollen IgE positive. Ratings of mood and allergic disease status were performed once during the peak airborne pollen counts and once during the period of low airborne pollen counts, as reported by two local pollen counting stations. Linear regression models were developed to examine associations of changes in depression scores (dependent variable with tree pollen sensitization, changes in the allergy symptom severity score, adjusted for gender and order of testing. We did not confirm the hypothesized relationship between a specific tree pollen sensitization and changes in mood during tree pollen exposure. We did confirm the hypothesized positive relationship between the changes in allergy symptoms and changes in subjects' depression scores (adjusted p<0.05. This result is consistent with previous epidemiological evidence connecting allergy with depression, as well as our recent reports of increased expression of cytokines in the prefrontal cortex in victims of suicide and in experimental animals sensitized and exposed to tree pollen. A relationship between changes in allergy symptom scores and changes in depression

  15. 'Peak oil' or 'peak demand'?

    International Nuclear Information System (INIS)

    Chevallier, Bruno; Moncomble, Jean-Eudes; Sigonney, Pierre; Vially, Rolland; Bosseboeuf, Didier; Chateau, Bertrand

    2012-01-01

    This article reports a workshop which addressed several energy issues like the objectives and constraints of energy mix scenarios, the differences between the approaches in different countries, the cost of new technologies implemented for this purposes, how these technologies will be developed and marketed, which will be the environmental and societal acceptability of these technical choices. Different aspects and issues have been more precisely presented and discussed: the peak oil, development of shale gases and their cost (will non conventional hydrocarbons modify the peak oil and be socially accepted?), energy efficiency (its benefits, its reality in France and other countries, its position in front of the challenge of energy transition), and strategies in the transport sector (challenges for mobility, evolution towards a model of sustainable mobility)

  16. First Ground-Based Infrared Solar Absorption Measurements of Free Tropospheric Methanol (CH3OH): Multidecade Infrared Time Series from Kitt Peak (31.9 deg N 111.6 deg W): Trend, Seasonal Cycle, and Comparison with Previous Measurements

    Science.gov (United States)

    Rinsland, Curtis P.; Mahieu, Emmanuel; Chiou, Linda; Herbin, Herve

    2009-01-01

    Atmospheric CH3OH (methanol) free tropospheric (2.09-14-km altitude) time series spanning 22 years has been analyzed on the basis of high-spectral resolution infrared solar absorption spectra of the strong vs band recorded from the U.S. National Solar Observatory on Kitt Peak (latitude 31.9degN, 111.6degW, 2.09-km altitude) with a 1-m Fourier transform spectrometer (FTS). The measurements span October 1981 to December 2003 and are the first long time series of CH3OH measurements obtained from the ground. The results were analyzed with SFIT2 version 3.93 and show a factor of three variations with season, a maximum at the beginning of July, a winter minimum, and no statistically significant long-term trend over the measurement time span.

  17. Impact of temperature inversions on SST evolution in the South-Eastern Arabian Sea during the pre-summer monsoon season

    Digital Repository Service at National Institute of Oceanography (India)

    Durand, F.; Shetye, S.R.; Vialard, J.; Shankar, D.; Shenoi, S.S.C.; Ethe, C.; Madec, G.

    Temperature inversions are known to occur in the near-surface ocean regime where salinity stratification is large enough to influence the density field. However, they have not been known as features that alter near-surface processes significantly...

  18. Influence of Media on Seasonal Influenza Epidemic Curves.

    Science.gov (United States)

    Saito, Satoshi; Saito, Norihiro; Itoga, Masamichi; Ozaki, Hiromi; Kimura, Toshiyuki; Okamura, Yuji; Murakami, Hiroshi; Kayaba, Hiroyuki

    2016-09-01

    Theoretical investigations predicting the epidemic curves of seasonal influenza have been demonstrated so far; however, there is little empirical research using ever accumulated epidemic curves. The effects of vaccine coverage and information distribution on influenza epidemics were evaluated. Four indices for epidemics (i.e., onset-peak duration, onset-end duration, ratio of the onset-peak duration to onset-end duration and steepness of epidemic curves) were defined, and the correlations between these indices and anti-flu drug prescription dose, vaccine coverage, the volume of media and search trend on influenza through internet were analyzed. Epidemiological data on seasonal influenza epidemics from 2002/2003 to 2013/2014 excluding 2009/2010 season were collected from National Institute of Infectious Diseases of Japan. The onset-peak duration and its ratio to onset-end duration correlated inversely with the volume of anti-flu drug prescription. Onset-peak duration correlated positively with media information volume on influenza. The steepness of the epidemic curve, and anti-flu drug prescription dose inversely correlated with the volume of media information. Pre-epidemic search trend and media volume on influenza correlated with the vaccine coverage in the season. Vaccine coverage had no strong effect on epidemic curve. Education through media has an effect on the epidemic curve of seasonal influenza. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  19. Lidar measurements of mesospheric temperature inversion at a low latitude

    Energy Technology Data Exchange (ETDEWEB)

    Siva Kumar, V.; Bhavani Kumar, Y.; Raghunath, K.; Rao, P.B. [National MST Radar Facility, Tirupati (India); Krishnaiah, M. [Sri Venkateswara Univ., Tirupati (India). Dept. of Physics; Mizutani, K.; Aoki, T.; Yasui, M.; Itabe, T. [Communication Research Lab., Tokyo (Japan)

    2001-08-01

    The Rayleigh lidar data collected on 119 nights from March 1998 to February 2000 were used to study the statistical characteristics of the low latitude mesospheric temperature inversion observed over Gadanki (13.5 N, 79.2 E), India. The occurrence frequency of the inversion showed semiannual variation with maxima in the equinoxes and minima in the summer and winter, which was quite different from that reported for the mid-latitudes. The peak of the inversion layer was found to be confined to the height range of 73 to 79 km with the maximum occurrence centered around 76 km, with a weak seasonal dependence that fits well to an annual cycle with a maximum in June and a minimum in December. The magnitude of the temperature deviation associated with the inversion was found to be as high as 32 K, with the most probable value occurring at about 20 K. Its seasonal dependence seems to follow an annual cycle with a maximum in April and a minimum in October. The observed characteristics of the inversion layer are compared with that of the mid-latitudes and discussed in light of the current understanding of the source mechanisms. (orig.)

  20. Lidar measurements of mesospheric temperature inversion at a low latitude

    Directory of Open Access Journals (Sweden)

    V. Siva Kumar

    2001-08-01

    Full Text Available The Rayleigh lidar data collected on 119 nights from March 1998 to February 2000 were used to study the statistical characteristics of the low latitude mesospheric temperature inversion observed over Gadanki (13.5° N, 79.2° E, India. The occurrence frequency of the inversion showed semiannual variation with maxima in the equinoxes and minima in the summer and winter, which was quite different from that reported for the mid-latitudes. The peak of the inversion layer was found to be confined to the height range of 73 to 79 km with the maximum occurrence centered around 76 km, with a weak seasonal dependence that fits well to an annual cycle with a maximum in June and a minimum in December. The magnitude of the temperature deviation associated with the inversion was found to be as high as 32 K, with the most probable value occurring at about 20 K. Its seasonal dependence seems to follow an annual cycle with a maximum in April and a minimum in October. The observed characteristics of the inversion layer are compared with that of the mid-latitudes and discussed in light of the current understanding of the source mechanisms.Key words. Atmospheric composition and structure (pressure, density and temperature. Meterology and atmospheric dynamics (climatology

  1. Lidar measurements of mesospheric temperature inversion at a low latitude

    Directory of Open Access Journals (Sweden)

    V. Siva Kumar

    Full Text Available The Rayleigh lidar data collected on 119 nights from March 1998 to February 2000 were used to study the statistical characteristics of the low latitude mesospheric temperature inversion observed over Gadanki (13.5° N, 79.2° E, India. The occurrence frequency of the inversion showed semiannual variation with maxima in the equinoxes and minima in the summer and winter, which was quite different from that reported for the mid-latitudes. The peak of the inversion layer was found to be confined to the height range of 73 to 79 km with the maximum occurrence centered around 76 km, with a weak seasonal dependence that fits well to an annual cycle with a maximum in June and a minimum in December. The magnitude of the temperature deviation associated with the inversion was found to be as high as 32 K, with the most probable value occurring at about 20 K. Its seasonal dependence seems to follow an annual cycle with a maximum in April and a minimum in October. The observed characteristics of the inversion layer are compared with that of the mid-latitudes and discussed in light of the current understanding of the source mechanisms.

    Key words. Atmospheric composition and structure (pressure, density and temperature. Meterology and atmospheric dynamics (climatology

  2. Inverse photoemission

    International Nuclear Information System (INIS)

    Namatame, Hirofumi; Taniguchi, Masaki

    1994-01-01

    Photoelectron spectroscopy is regarded as the most powerful means since it can measure almost perfectly the occupied electron state. On the other hand, inverse photoelectron spectroscopy is the technique for measuring unoccupied electron state by using the inverse process of photoelectron spectroscopy, and in principle, the similar experiment to photoelectron spectroscopy becomes feasible. The development of the experimental technology for inverse photoelectron spectroscopy has been carried out energetically by many research groups so far. At present, the heightening of resolution of inverse photoelectron spectroscopy, the development of inverse photoelectron spectroscope in which light energy is variable and so on are carried out. But the inverse photoelectron spectroscope for vacuum ultraviolet region is not on the market. In this report, the principle of inverse photoelectron spectroscopy and the present state of the spectroscope are described, and the direction of the development hereafter is groped. As the experimental equipment, electron guns, light detectors and so on are explained. As the examples of the experiment, the inverse photoelectron spectroscopy of semimagnetic semiconductors and resonance inverse photoelectron spectroscopy are reported. (K.I.)

  3. Inverse Limits

    CERN Document Server

    Ingram, WT

    2012-01-01

    Inverse limits provide a powerful tool for constructing complicated spaces from simple ones. They also turn the study of a dynamical system consisting of a space and a self-map into a study of a (likely more complicated) space and a self-homeomorphism. In four chapters along with an appendix containing background material the authors develop the theory of inverse limits. The book begins with an introduction through inverse limits on [0,1] before moving to a general treatment of the subject. Special topics in continuum theory complete the book. Although it is not a book on dynamics, the influen

  4. Peak Wind Tool for General Forecasting

    Science.gov (United States)

    Barrett, Joe H., III

    2010-01-01

    The expected peak wind speed of the day is an important forecast element in the 45th Weather Squadron's (45 WS) daily 24-Hour and Weekly Planning Forecasts. The forecasts are used for ground and space launch operations at the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The 45 WS also issues wind advisories for KSC/CCAFS when they expect wind gusts to meet or exceed 25 kt, 35 kt and 50 kt thresholds at any level from the surface to 300 ft. The 45 WS forecasters have indicated peak wind speeds are challenging to forecast, particularly in the cool season months of October - April. In Phase I of this task, the Applied Meteorology Unit (AMU) developed a tool to help the 45 WS forecast non-convective winds at KSC/CCAFS for the 24-hour period of 0800 to 0800 local time. The tool was delivered as a Microsoft Excel graphical user interface (GUI). The GUI displayed the forecast of peak wind speed, 5-minute average wind speed at the time of the peak wind, timing of the peak wind and probability the peak speed would meet or exceed 25 kt, 35 kt and 50 kt. For the current task (Phase II ), the 45 WS requested additional observations be used for the creation of the forecast equations by expanding the period of record (POR). Additional parameters were evaluated as predictors, including wind speeds between 500 ft and 3000 ft, static stability classification, Bulk Richardson Number, mixing depth, vertical wind shear, temperature inversion strength and depth and wind direction. Using a verification data set, the AMU compared the performance of the Phase I and II prediction methods. Just as in Phase I, the tool was delivered as a Microsoft Excel GUI. The 45 WS requested the tool also be available in the Meteorological Interactive Data Display System (MIDDS). The AMU first expanded the POR by two years by adding tower observations, surface observations and CCAFS (XMR) soundings for the cool season months of March 2007 to April 2009. The POR was expanded

  5. Inverse Kinematics

    Directory of Open Access Journals (Sweden)

    Joel Sereno

    2010-01-01

    Full Text Available Inverse kinematics is the process of converting a Cartesian point in space into a set of joint angles to more efficiently move the end effector of a robot to a desired orientation. This project investigates the inverse kinematics of a robotic hand with fingers under various scenarios. Assuming the parameters of a provided robot, a general equation for the end effector point was calculated and used to plot the region of space that it can reach. Further, the benefits obtained from the addition of a prismatic joint versus an extra variable angle joint were considered. The results confirmed that having more movable parts, such as prismatic points and changing angles, increases the effective reach of a robotic hand.

  6. Multidimensional inversion

    International Nuclear Information System (INIS)

    Desesquelles, P.

    1997-01-01

    Computer Monte Carlo simulations occupy an increasingly important place between theory and experiment. This paper introduces a global protocol for the comparison of model simulations with experimental results. The correlated distributions of the model parameters are determined using an original recursive inversion procedure. Multivariate analysis techniques are used in order to optimally synthesize the experimental information with a minimum number of variables. This protocol is relevant in all fields if physics dealing with event generators and multi-parametric experiments. (authors)

  7. Large-scale control of the Arabian Sea monsoon inversion in August

    Science.gov (United States)

    Wu, Chi-Hua; Wang, S.-Y. Simon; Hsu, Huang-Hsiung

    2017-12-01

    The summer monsoon inversion in the Arabian Sea is characterized by a large amount of low clouds and August as the peak season. Atmospheric stratification associated with the monsoon inversion has been considered a local system influenced by the advancement of the India-Pakistan monsoon. Empirical and numerical evidence from this study suggests that the Arabian Sea monsoon inversion is linked to a broader-scale monsoon evolution across the African Sahel, South Asia, and East Asia-Western North Pacific (WNP), rather than being a mere byproduct of the India-Pakistan monsoon progression. In August, the upper-tropospheric anticyclone in South Asia extends sideways corresponding with the enhanced precipitation in the subtropical WNP, equatorial Indian Ocean, and African Sahel while the middle part of this anticyclone weakens over the Arabian Sea. The increased heating in the adjacent monsoon systems creates a suppression effect on the Arabian Sea, suggesting an apparent competition among the Africa-Asia-WNP monsoon subsystems. The peak Sahel rainfall in August, together with enhanced heating in the equatorial Indian Ocean, produces a critical effect on strengthening the Arabian Sea thermal inversion. By contrast, the WNP monsoon onset which signifies the eastward expansion of the subtropical Asian monsoon heating might play a secondary or opposite role in the Arabian Sea monsoon inversion.

  8. Peak Experience Project

    Science.gov (United States)

    Scott, Daniel G.; Evans, Jessica

    2010-01-01

    This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

  9. Peak-interviewet

    DEFF Research Database (Denmark)

    Raalskov, Jesper; Warming-Rasmussen, Bent

    Peak-interviewet er en særlig effektiv metode til at gøre ubevidste menneskelige ressourcer bevidste. Fokuspersonen (den interviewede) interviewes om en selvvalgt, personlig succesoplevelse. Terapeuten/coachen (intervieweren) spørger ind til processen, som ledte hen til denne succes. Herved afdæk...... fokuspersonen ønsker at tage op (nye mål eller nye processer). Nærværende workingpaper beskriver, hvad der menes med et peak-interview, peakinterviwets teoretiske fundament samt metodikken til at foretage et tillidsfuldt og effektiv peak-interview....

  10. Peak power ratio generator

    Science.gov (United States)

    Moyer, R.D.

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  11. Peak Oil, Peak Coal and Climate Change

    Science.gov (United States)

    Murray, J. W.

    2009-05-01

    Research on future climate change is driven by the family of scenarios developed for the IPCC assessment reports. These scenarios create projections of future energy demand using different story lines consisting of government policies, population projections, and economic models. None of these scenarios consider resources to be limiting. In many of these scenarios oil production is still increasing to 2100. Resource limitation (in a geological sense) is a real possibility that needs more serious consideration. The concept of 'Peak Oil' has been discussed since M. King Hubbert proposed in 1956 that US oil production would peak in 1970. His prediction was accurate. This concept is about production rate not reserves. For many oil producing countries (and all OPEC countries) reserves are closely guarded state secrets and appear to be overstated. Claims that the reserves are 'proven' cannot be independently verified. Hubbert's Linearization Model can be used to predict when half the ultimate oil will be produced and what the ultimate total cumulative production (Qt) will be. US oil production can be used as an example. This conceptual model shows that 90% of the ultimate US oil production (Qt = 225 billion barrels) will have occurred by 2011. This approach can then be used to suggest that total global production will be about 2200 billion barrels and that the half way point will be reached by about 2010. This amount is about 5 to 7 times less than assumed by the IPCC scenarios. The decline of Non-OPEC oil production appears to have started in 2004. Of the OPEC countries, only Saudi Arabia may have spare capacity, but even that is uncertain, because of lack of data transparency. The concept of 'Peak Coal' is more controversial, but even the US National Academy Report in 2007 concluded only a small fraction of previously estimated reserves in the US are actually minable reserves and that US reserves should be reassessed using modern methods. British coal production can be

  12. Field evaluation of a PfHRP-2/pLDH rapid diagnostic test and light microscopy for diagnosis and screening of falciparum malaria during the peak seasonal transmission in an endemic area in Yemen.

    Science.gov (United States)

    Alareqi, Lina M Q; Mahdy, Mohammed A K; Lau, Yee-Ling; Fong, Mun-Yik; Abdul-Ghani, Rashad; Ali, Arwa A; Cheong, Fei-Wen; Tawfek, Rehab; Mahmud, Rohela

    2016-01-28

    Malaria is a public health threat in Yemen, with 149,451 cases being reported in 2013. Of these, Plasmodium falciparum represents 99%. Prompt diagnosis by light microscopy (LM) and rapid diagnostic tests (RTDs) is a key element in the national strategy of malaria control. The heterogeneous epidemiology of malaria in the country necessitates the field evaluation of the current diagnostic strategies, especially RDTs. Thus, the present study aimed to evaluate LM and an RDT, combining both P. falciparum histidine-rich protein-2 (PfHRP-2) and Plasmodium lactate dehydrogenase (pLDH), for falciparum malaria diagnosis and survey in a malaria-endemic area during the transmission season against nested polymerase chain reaction (PCR) as the reference method. A household-based, cross-sectional malaria survey was conducted in Mawza District, a malaria-endemic area in Taiz governorate. A total of 488 participants were screened using LM and PfHRP-2/pLDH RDT. Positive samples (160) and randomly selected negative samples (52) by both RDT and LM were further analysed using 18S rRNA-based nested PCR. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the RDT were 96.0% (95% confidence interval (CI): 90.9-98.3), 56.0% (95% CI: 44.7-66.8), 76.3% (95% CI: 69.0-82.3), and 90.4% (95% CI: 78.8-96.8), respectively. On the other hand, LM showed sensitivity of 37.6% (95% CI: 29.6-46.3), specificity of 97.6% (95% CI: 91.7-99.7), PPV of 95.9% (95% CI: 86.3-98.9), and NPV of 51.3% (95% CI: 43.2-59.2). The sensitivity of LM dropped to 8.5% for detecting asymptomatic malaria. Malaria prevalence was 32.8% (32.1 and 37.5% for ≥10 and <10 years, respectively) with the RDT compared with 10.7% (10.8 and 9.4% for age groups of ≥10 and <10 years, respectively) with LM. Among asymptomatic malaria individuals, LM and RDT-based prevalence rates were 1.6 and 25.6%, respectively. However, rates of 88.2 and 94.1% of infection with P. falciparum were found

  13. Peak regulation right

    International Nuclear Information System (INIS)

    Gao, Z. |; Ren, Z.; Li, Z.; Zhu, R.

    2005-01-01

    A peak regulation right concept and corresponding transaction mechanism for an electricity market was presented. The market was based on a power pool and independent system operator (ISO) model. Peak regulation right (PRR) was defined as a downward regulation capacity purchase option which allowed PRR owners to buy certain quantities of peak regulation capacity (PRC) at a specific price during a specified period from suppliers. The PRR owner also had the right to decide whether or not they would buy PRC from suppliers. It was the power pool's responsibility to provide competitive and fair peak regulation trading markets to participants. The introduction of PRR allowed for unit capacity regulation. The PRR and PRC were rated by the supplier, and transactions proceeded through a bidding process. PRR suppliers obtained profits by selling PRR and PRC, and obtained downward regulation fees regardless of whether purchases are made. It was concluded that the peak regulation mechanism reduced the total cost of the generating system and increased the social surplus. 6 refs., 1 tab., 3 figs

  14. Make peak flow a habit

    Science.gov (United States)

    Asthma - make peak flow a habit; Reactive airway disease - peak flow; Bronchial asthma - peak flow ... 2014:chap 55. National Asthma Education and Prevention Program website. How to use a peak flow meter. ...

  15. Automated asteroseismic peak detections

    DEFF Research Database (Denmark)

    de Montellano, Andres Garcia Saravia Ortiz; Hekker, S.; Themessl, N.

    2018-01-01

    Space observatories such as Kepler have provided data that can potentially revolutionize our understanding of stars. Through detailed asteroseismic analyses we are capable of determining fundamental stellar parameters and reveal the stellar internal structure with unprecedented accuracy. However......, such detailed analyses, known as peak bagging, have so far been obtained for only a small percentage of the observed stars while most of the scientific potential of the available data remains unexplored. One of the major challenges in peak bagging is identifying how many solar-like oscillation modes are visible...... of detected oscillation modes. The algorithm presented here opens the possibility for detailed and automated peak bagging of the thousands of solar-like oscillators observed by Kepler....

  16. Automated asteroseismic peak detections

    Science.gov (United States)

    García Saravia Ortiz de Montellano, Andrés; Hekker, S.; Themeßl, N.

    2018-05-01

    Space observatories such as Kepler have provided data that can potentially revolutionize our understanding of stars. Through detailed asteroseismic analyses we are capable of determining fundamental stellar parameters and reveal the stellar internal structure with unprecedented accuracy. However, such detailed analyses, known as peak bagging, have so far been obtained for only a small percentage of the observed stars while most of the scientific potential of the available data remains unexplored. One of the major challenges in peak bagging is identifying how many solar-like oscillation modes are visible in a power density spectrum. Identification of oscillation modes is usually done by visual inspection that is time-consuming and has a degree of subjectivity. Here, we present a peak-detection algorithm especially suited for the detection of solar-like oscillations. It reliably characterizes the solar-like oscillations in a power density spectrum and estimates their parameters without human intervention. Furthermore, we provide a metric to characterize the false positive and false negative rates to provide further information about the reliability of a detected oscillation mode or the significance of a lack of detected oscillation modes. The algorithm presented here opens the possibility for detailed and automated peak bagging of the thousands of solar-like oscillators observed by Kepler.

  17. Seasonality of Suicidal Behavior

    Science.gov (United States)

    Woo, Jong-Min; Okusaga, Olaoluwa; Postolache, Teodor T.

    2012-01-01

    A seasonal suicide peak in spring is highly replicated, but its specific cause is unknown. We reviewed the literature on suicide risk factors which can be associated with seasonal variation of suicide rates, assessing published articles from 1979 to 2011. Such risk factors include environmental determinants, including physical, chemical, and biological factors. We also summarized the influence of potential demographic and clinical characteristics such as age, gender, month of birth, socioeconomic status, methods of prior suicide attempt, and comorbid psychiatric and medical diseases. Comprehensive evaluation of risk factors which could be linked to the seasonal variation in suicide is important, not only to identify the major driving force for the seasonality of suicide, but also could lead to better suicide prevention in general. PMID:22470308

  18. Daily Nigerian peak load forecasting using artificial neural network ...

    African Journals Online (AJOL)

    A daily peak load forecasting technique that uses artificial neural network with seasonal indices is presented in this paper. A neural network of relatively smaller size than the main prediction network is used to predict the daily peak load for a period of one year over which the actual daily load data are available using one ...

  19. Peak reading detector circuit

    International Nuclear Information System (INIS)

    Courtin, E.; Grund, K.; Traub, S.; Zeeb, H.

    1975-01-01

    The peak reading detector circuit serves for picking up the instants during which peaks of a given polarity occur in sequences of signals in which the extreme values, their time intervals, and the curve shape of the signals vary. The signal sequences appear in measuring the foetal heart beat frequence from amplitude-modulated ultrasonic, electrocardiagram, and blood pressure signals. In order to prevent undesired emission of output signals from, e. g., disturbing intermediate extreme values, the circuit consists of the series connections of a circuit to simulate an ideal diode, a strong unit, a discriminator for the direction of charging current, a time-delay circuit, and an electronic switch lying in the decharging circuit of the storage unit. The time-delay circuit thereby causes storing of a preliminary maximum value being used only after a certain time delay for the emission of the output signal. If a larger extreme value occurs during the delay time the preliminary maximum value is cleared and the delay time starts running anew. (DG/PB) [de

  20. Seasonal reproduction of vampire bats and its relation to seasonality of bovine rabies.

    Science.gov (United States)

    Lord, R D

    1992-04-01

    Studies of pregnancy and lactation in vampire bats (Desmodus rotundus) in northern Argentina over a 4 yr period showed an inverse relationship between prevalence of pregnancy and lactation, the consequence of birth and onset of lactation, which was correlated with the wet season. The seasonal influx of young susceptibles into the vampire population in the wet season coincided with the well known increase in vampire transmitted rabies in that season.

  1. Inverse problems of geophysics

    International Nuclear Information System (INIS)

    Yanovskaya, T.B.

    2003-07-01

    This report gives an overview and the mathematical formulation of geophysical inverse problems. General principles of statistical estimation are explained. The maximum likelihood and least square fit methods, the Backus-Gilbert method and general approaches for solving inverse problems are discussed. General formulations of linearized inverse problems, singular value decomposition and properties of pseudo-inverse solutions are given

  2. Superconductivity in Pb inverse opal

    International Nuclear Information System (INIS)

    Aliev, Ali E.; Lee, Sergey B.; Zakhidov, Anvar A.; Baughman, Ray H.

    2007-01-01

    Type-II superconducting behavior was observed in highly periodic three-dimensional lead inverse opal prepared by infiltration of melted Pb in blue (D = 160 nm), green (D = 220 nm) and red (D = 300 nm) opals and followed by the extraction of the SiO 2 spheres by chemical etching. The onset of a broad phase transition (ΔT = 0.3 K) was shifted from T c = 7.196 K for bulk Pb to T c = 7.325 K. The upper critical field H c2 (3150 Oe) measured from high-field hysteresis loops exceeds the critical field for bulk lead (803 Oe) fourfold. Two well resolved peaks observed in the hysteresis loops were ascribed to flux penetration into the cylindrical void space that can be found in inverse opal structure and into the periodic structure of Pb nanoparticles. The red inverse opal shows pronounced oscillations of magnetic moment in the mixed state at low temperatures, T 0.9T c has been observed for all of the samples studied. The magnetic field periodicity of resistivity modulation is in good agreement with the lattice parameter of the inverse opal structure. We attribute the failure to observe pronounced modulation in magneto-resistive measurement to difficulties in the precision orientation of the sample along the magnetic field

  3. Inverse Cerenkov experiment

    International Nuclear Information System (INIS)

    Kimura, W.D.

    1993-01-01

    The final report describes work performed to investigate inverse Cherenkov acceleration (ICA) as a promising method for laser particle acceleration. In particular, an improved configuration of ICA is being tested in a experiment presently underway on the Accelerator Test Facility (ATF). In the experiment, the high peak power (∼ 10 GW) linearly polarized ATF CO 2 laser beam is converted to a radially polarized beam. This is beam is focused with an axicon at the Cherenkov angle onto the ATF 50-MeV e-beam inside a hydrogen gas cell, where the gas acts as the phase matching medium of the interaction. An energy gain of ∼12 MeV is predicted assuming a delivered laser peak power of 5 GW. The experiment is divided into two phases. The Phase I experiments, which were completed in the spring of 1992, were conducted before the ATF e-beam was available and involved several successful tests of the optical systems. Phase II experiments are with the e-beam and laser beam, and are still in progress. The ATF demonstrated delivery of the e-beam to the experiment in Dec. 1992. A preliminary ''debugging'' run with the e-beam and laser beam occurred in May 1993. This revealed the need for some experimental modifications, which have been implemented. The second run is tentatively scheduled for October or November 1993. In parallel to the experimental efforts has been ongoing theoretical work to support the experiment and investigate improvement and/or offshoots. One exciting offshoot has been theoretical work showing that free-space laser acceleration of electrons is possible using a radially-polarized, axicon-focused laser beam, but without any phase-matching gas. The Monte Carlo code used to model the ICA process has been upgraded and expanded to handle different types of laser beam input profiles

  4. Effect of seasonal flooding cycle on litterfall production in alluvial rainforest on the middle Xingu River (Amazon basin, Brazil).

    Science.gov (United States)

    Camargo, M; Giarrizzo, T; Jesus, A J S

    2015-08-01

    The assumption for this study was that litterfall in floodplain environments of the middle Xingu river follows a pattern of seasonal variation. According to this view, litterfall production (total and fractions) was estimated in four alluvial rainforest sites on the middle Xingu River over an annual cycle, and examined the effect of seasonal flooding cycle. The sites included two marginal flooded forests of insular lakes (Ilha Grande and Pimentel) and two flooded forests on the banks of the Xingu itself (Boa Esperança and Arroz Cru). Total litterfall correlated with rainfall and river levels, but whereas the leaf and fruit fractions followed this general pattern, the flower fraction presented an inverse pattern, peaking in the dry season. The litterfall patterns recorded in the present study were consistent with those recorded at other Amazonian sites, and in some other tropical ecosystems.

  5. Sources and Dynamic Processes Controlling Background and Peak Concentrations of TGM in Nanjing, China

    Directory of Open Access Journals (Sweden)

    Casey B. Hall

    2014-03-01

    Full Text Available Total gaseous mercury (TGM data from urban Nanjing, at the western edge of the Yangtze River Delta (YRD region in China, over nine months, were analyzed for peak and background mercury concentrations. The background concentration of TGM was found to be 2.2 ng∙m−3. In examining episodic influences of free tropospheric air masses on the surface TGM concentrations in Nanjing, we hypothesize heterogeneity in the global distribution of TGM concentrations in the free troposphere. The nine-month averaged diurnal cycles of TGM indicate a strong co-emission with SO2 and an underestimation of greater than 80% TGM emissions in current inventories. Regular peak concentrations of mercury were investigated and the major causes were YRD emissions, transport from rural areas, and monsoonal transport. Transport of rural emissions is hypothesized to be from illegal artisanal small-scale gold mining that are currently missing in the emission inventories. Enhancement of TGM associated with summer monsoon contributed to a maximum TGM concentration in mid-May–early June, an inverse seasonality in comparison to most other observations in China, North America, and Europe.

  6. LHC Report: 2 inverse femtobarns!

    CERN Multimedia

    Mike Lamont for the LHC Team

    2011-01-01

    The LHC is enjoying a confluence of twos. This morning (Friday 5 August) we passed 2 inverse femtobarns delivered in 2011; the peak luminosity is now just over 2 x1033 cm-2s-1; and recently fill 2000 was in for nearly 22 hours and delivered around 90 inverse picobarns, almost twice 2010's total.   In order to increase the luminosity we can increase of number of bunches, increase the number of particles per bunch, or decrease the transverse beam size at the interaction point. The beam size can be tackled in two ways: either reduce the size of the injected bunches or squeeze harder with the quadrupole magnets situated on either side of the experiments. Having increased the number of bunches to 1380, the maximum possible with a 50 ns bunch spacing, a one day meeting in Crozet decided to explore the other possibilities. The size of the beams coming from the injectors has been reduced to the minimum possible. This has brought an increase in the peak luminosity of about 50% and the 2 x 1033 cm...

  7. Convex blind image deconvolution with inverse filtering

    Science.gov (United States)

    Lv, Xiao-Guang; Li, Fang; Zeng, Tieyong

    2018-03-01

    Blind image deconvolution is the process of estimating both the original image and the blur kernel from the degraded image with only partial or no information about degradation and the imaging system. It is a bilinear ill-posed inverse problem corresponding to the direct problem of convolution. Regularization methods are used to handle the ill-posedness of blind deconvolution and get meaningful solutions. In this paper, we investigate a convex regularized inverse filtering method for blind deconvolution of images. We assume that the support region of the blur object is known, as has been done in a few existing works. By studying the inverse filters of signal and image restoration problems, we observe the oscillation structure of the inverse filters. Inspired by the oscillation structure of the inverse filters, we propose to use the star norm to regularize the inverse filter. Meanwhile, we use the total variation to regularize the resulting image obtained by convolving the inverse filter with the degraded image. The proposed minimization model is shown to be convex. We employ the first-order primal-dual method for the solution of the proposed minimization model. Numerical examples for blind image restoration are given to show that the proposed method outperforms some existing methods in terms of peak signal-to-noise ratio (PSNR), structural similarity (SSIM), visual quality and time consumption.

  8. Peak capacity and peak capacity per unit time in capillary and microchip zone electrophoresis.

    Science.gov (United States)

    Foley, Joe P; Blackney, Donna M; Ennis, Erin J

    2017-11-10

    The origins of the peak capacity concept are described and the important contributions to the development of that concept in chromatography and electrophoresis are reviewed. Whereas numerous quantitative expressions have been reported for one- and two-dimensional separations, most are focused on chromatographic separations and few, if any, quantitative unbiased expressions have been developed for capillary or microchip zone electrophoresis. Making the common assumption that longitudinal diffusion is the predominant source of zone broadening in capillary electrophoresis, analytical expressions for the peak capacity are derived, first in terms of migration time, diffusion coefficient, migration distance, and desired resolution, and then in terms of the remaining underlying fundamental parameters (electric field, electroosmotic and electrophoretic mobilities) that determine the migration time. The latter expressions clearly illustrate the direct square root dependence of peak capacity on electric field and migration distance and the inverse square root dependence on solute diffusion coefficient. Conditions that result in a high peak capacity will result in a low peak capacity per unit time and vice-versa. For a given symmetrical range of relative electrophoretic mobilities for co- and counter-electroosmotic species (cations and anions), the peak capacity increases with the square root of the electric field even as the temporal window narrows considerably, resulting in a significant reduction in analysis time. Over a broad relative electrophoretic mobility interval [-0.9, 0.9], an approximately two-fold greater amount of peak capacity can be generated for counter-electroosmotic species although it takes about five-fold longer to do so, consistent with the well-known bias in migration time and resolving power for co- and counter-electroosmotic species. The optimum lower bound of the relative electrophoretic mobility interval [μ r,Z , μ r,A ] that provides the maximum

  9. Acute puerperal uterine inversion

    International Nuclear Information System (INIS)

    Hussain, M.; Liaquat, N.; Noorani, K.; Bhutta, S.Z; Jabeen, T.

    2004-01-01

    Objective: To determine the frequency, causes, clinical presentations, management and maternal mortality associated with acute puerperal inversion of the uterus. Materials and Methods: All the patients who developed acute puerperal inversion of the uterus either in or outside the JPMC were included in the study. Patients of chronic uterine inversion were not included in the present study. Abdominal and vaginal examination was done to confirm and classify inversion into first, second or third degrees. Results: 57036 deliveries and 36 acute uterine inversions occurred during the study period, so the frequency of uterine inversion was 1 in 1584 deliveries. Mismanagement of third stage of labour was responsible for uterine inversion in 75% of patients. Majority of the patients presented with shock, either hypovolemic (69%) or neurogenic (13%) in origin. Manual replacement of the uterus under general anaesthesia with 2% halothane was successfully done in 35 patients (97.5%). Abdominal hysterectomy was done in only one patient. There were three maternal deaths due to inversion. Conclusion: Proper education and training regarding placental delivery, diagnosis and management of uterine inversion must be imparted to the maternity care providers especially to traditional birth attendants and family physicians to prevent this potentially life-threatening condition. (author)

  10. Upper limit of peak area

    International Nuclear Information System (INIS)

    Helene, O.A.M.

    1982-08-01

    The determination of the upper limit of peak area in a multi-channel spectra, with a known significance level is discussed. This problem is specially important when the peak area is masked by the background statistical fluctuations. The problem is exactly solved and, thus, the results are valid in experiments with small number of events. The results are submitted to a Monte Carlo test and applied to the 92 Nb beta decay. (Author) [pt

  11. Inverse logarithmic potential problem

    CERN Document Server

    Cherednichenko, V G

    1996-01-01

    The Inverse and Ill-Posed Problems Series is a series of monographs publishing postgraduate level information on inverse and ill-posed problems for an international readership of professional scientists and researchers. The series aims to publish works which involve both theory and applications in, e.g., physics, medicine, geophysics, acoustics, electrodynamics, tomography, and ecology.

  12. Inverse Kinematics using Quaternions

    DEFF Research Database (Denmark)

    Henriksen, Knud; Erleben, Kenny; Engell-Nørregård, Morten

    In this project I describe the status of inverse kinematics research, with the focus firmly on the methods that solve the core problem. An overview of the different methods are presented Three common methods used in inverse kinematics computation have been chosen as subject for closer inspection....

  13. Peak Oil and other threatening peaks-Chimeras without substance

    International Nuclear Information System (INIS)

    Radetzki, Marian

    2010-01-01

    The Peak Oil movement has widely spread its message about an impending peak in global oil production, caused by an inadequate resource base. On closer scrutiny, the underlying analysis is inconsistent, void of a theoretical foundation and without support in empirical observations. Global oil resources are huge and expanding, and pose no threat to continuing output growth within an extended time horizon. In contrast, temporary or prolonged supply crunches are indeed plausible, even likely, on account of growing resource nationalism denying access to efficient exploitation of the existing resource wealth.

  14. Electricity Portfolio Management: Optimal Peak / Off-Peak Allocations

    OpenAIRE

    Huisman, Ronald; Mahieu, Ronald; Schlichter, Felix

    2007-01-01

    textabstractElectricity purchasers manage a portfolio of contracts in order to purchase the expected future electricity consumption profile of a company or a pool of clients. This paper proposes a mean-variance framework to address the concept of structuring the portfolio and focuses on how to allocate optimal positions in peak and off-peak forward contracts. It is shown that the optimal allocations are based on the difference in risk premiums per unit of day-ahead risk as a measure of relati...

  15. Ultrasonic Transducer Peak-to-Peak Optical Measurement

    Directory of Open Access Journals (Sweden)

    Pavel Skarvada

    2012-01-01

    Full Text Available Possible optical setups for measurement of the peak-to-peak value of an ultrasonic transducer are described in this work. The Michelson interferometer with the calibrated nanopositioner in reference path and laser Doppler vibrometer were used for the basic measurement of vibration displacement. Langevin type of ultrasonic transducer is used for the purposes of Electro-Ultrasonic Nonlinear Spectroscopy (EUNS. Parameters of produced mechanical vibration have to been well known for EUNS. Moreover, a monitoring of mechanical vibration frequency shift with a mass load and sample-transducer coupling is important for EUNS measurement.

  16. Peaking-factor of PWR

    International Nuclear Information System (INIS)

    Morioka, Noboru; Kato, Yasuji; Yokoi, M.

    1975-01-01

    Output peaking factor often plays an important role in the safety and operation of nuclear reactors. The meaning of the peaking factor of PWRs is categorized into two features or the peaking factor in core (FQ-core) and the peaking factor on the basis of accident analysis (or FQ-limit). FQ-core is the actual peaking factor realized in nuclear core at the time of normal operation, and FQ-limit should be evaluated from loss of coolant accident and other abnormal conditions. If FQ-core is lower than FQ-limit, the reactor may be operated at full load, but if FQ-core is larger than FQ-limit, reactor output should be controlled lower than FQ-limit. FQ-core has two kinds of values, or the one on the basis of nuclear design, and the other actually measured in reactor operation. The first FQ-core should be named as FQ-core-design and the latter as FQ-core-measured. The numerical evaluation of FQ-core-design is as follows; FQ-core-design of three-dimensions is synthesized with FQ-core horizontal value (X-Y) and FQ-core vertical value, the former one is calculated with ASSY-CORE code, and the latter one with one dimensional diffusion code. For the evaluation of FQ-core-measured, on-site data observation from nuclear reactor instrumentation or off-site data observation is used. (Iwase, T.)

  17. How to use your peak flow meter

    Science.gov (United States)

    ... meter - how to use; Asthma - peak flow meter; Reactive airway disease - peak flow meter; Bronchial asthma - peak ... 2014:chap 55. National Asthma Education and Prevention Program website. How to use a peak flow meter. ...

  18. Gravity inversion code

    International Nuclear Information System (INIS)

    Burkhard, N.R.

    1979-01-01

    The gravity inversion code applies stabilized linear inverse theory to determine the topography of a subsurface density anomaly from Bouguer gravity data. The gravity inversion program consists of four source codes: SEARCH, TREND, INVERT, and AVERAGE. TREND and INVERT are used iteratively to converge on a solution. SEARCH forms the input gravity data files for Nevada Test Site data. AVERAGE performs a covariance analysis on the solution. This document describes the necessary input files and the proper operation of the code. 2 figures, 2 tables

  19. Peak effect in twinned superconductors

    International Nuclear Information System (INIS)

    Larkin, A.I.; Marchetti, M.C.; Vinokur, V.M.

    1995-01-01

    A sharp maximum in the critical current J c as a function of temperature just below the melting point of the Abrikosov flux lattice has recently been observed in both low- and high-temperature superconductors. This peak effect is strongest in twinned crystals for fields aligned with the twin planes. We propose that this peak signals the breakdown of the collective pinning regime and the crossover to strong pinning of single vortices on the twin boundaries. This crossover is very sharp and can account for the steep drop of the differential resistivity observed in experiments. copyright 1995 The American Physical Society

  20. Sharp spatially constrained inversion

    DEFF Research Database (Denmark)

    Vignoli, Giulio G.; Fiandaca, Gianluca G.; Christiansen, Anders Vest C A.V.C.

    2013-01-01

    We present sharp reconstruction of multi-layer models using a spatially constrained inversion with minimum gradient support regularization. In particular, its application to airborne electromagnetic data is discussed. Airborne surveys produce extremely large datasets, traditionally inverted...... by using smoothly varying 1D models. Smoothness is a result of the regularization constraints applied to address the inversion ill-posedness. The standard Occam-type regularized multi-layer inversion produces results where boundaries between layers are smeared. The sharp regularization overcomes...... inversions are compared against classical smooth results and available boreholes. With the focusing approach, the obtained blocky results agree with the underlying geology and allow for easier interpretation by the end-user....

  1. Inverse planning IMRT

    International Nuclear Information System (INIS)

    Rosenwald, J.-C.

    2008-01-01

    The lecture addressed the following topics: Optimizing radiotherapy dose distribution; IMRT contributes to optimization of energy deposition; Inverse vs direct planning; Main steps of IMRT; Background of inverse planning; General principle of inverse planning; The 3 main components of IMRT inverse planning; The simplest cost function (deviation from prescribed dose); The driving variable : the beamlet intensity; Minimizing a 'cost function' (or 'objective function') - the walker (or skier) analogy; Application to IMRT optimization (the gradient method); The gradient method - discussion; The simulated annealing method; The optimization criteria - discussion; Hard and soft constraints; Dose volume constraints; Typical user interface for definition of optimization criteria; Biological constraints (Equivalent Uniform Dose); The result of the optimization process; Semi-automatic solutions for IMRT; Generalisation of the optimization problem; Driving and driven variables used in RT optimization; Towards multi-criteria optimization; and Conclusions for the optimization phase. (P.A.)

  2. Hubbert's Peak -- A Physicist's View

    Science.gov (United States)

    McDonald, Richard

    2011-04-01

    Oil, as used in agriculture and transportation, is the lifeblood of modern society. It is finite in quantity and will someday be exhausted. In 1956, Hubbert proposed a theory of resource production and applied it successfully to predict peak U.S. oil production in 1970. Bartlett extended this work in publications and lectures on the finite nature of oil and its production peak and depletion. Both Hubbert and Bartlett place peak world oil production at a similar time, essentially now. Central to these analyses are estimates of total ``oil in place'' obtained from engineering studies of oil reservoirs as this quantity determines the area under the Hubbert's Peak. Knowing the production history and the total oil in place allows us to make estimates of reserves, and therefore future oil availability. We will then examine reserves data for various countries, in particular OPEC countries, and see if these data tell us anything about the future availability of oil. Finally, we will comment on synthetic oil and the possibility of carbon-neutral synthetic oil for a sustainable future.

  3. Objective mapping of observed sub-surface mesoscale cold core eddy in the Bay of Bengal by stochastic inverse technique with tomographically simulated travel times

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, T.V.R.; Rao, M.M.M.; Sadhuram, Y.; Sridevi, B.; Maneesha, K.; SujithKumar, S.; Prasanna, P.L.; Murthy, K.S.R.

    of Bengal during south-west monsoon season and explore possibility to reconstruct the acoustic profile of the eddy by Stochastic Inverse Technique. A simulation experiment on forward and inverse problems for observed sound velocity perturbation field has...

  4. Flu season and trehalose

    Directory of Open Access Journals (Sweden)

    Robbins RA

    2018-01-01

    Full Text Available Most of us who are practicing medicine know that we are in a very active flu season. This was brought home to me when last week trying to admit a patient to the hospital from the office. She was a bone marrow transplant patient who had severe diarrhea and dehydration probably secondary to C. difficile. Hospital admissions said the patient had to be sent to the Emergency Room because the hospital was full due to the flu epidemic. Nationwide there has been a dramatic increase in the number of hospitalizations due to influenza over the past week from 13.7 to 22.7 per 100,000 (1. Influenza A(H3N2 has been the most common form of influenza reported this season. These viruses are often linked to more severe illness, especially in children and people age 65 years and older. Fortunately, the CDC also says that the flu cases may be peaking. However, at ...

  5. SPANISH PEAKS PRIMITIVE AREA, MONTANA.

    Science.gov (United States)

    Calkins, James A.; Pattee, Eldon C.

    1984-01-01

    A mineral survey of the Spanish Peaks Primitive Area, Montana, disclosed a small low-grade deposit of demonstrated chromite and asbestos resources. The chances for discovery of additional chrome resources are uncertain and the area has little promise for the occurrence of other mineral or energy resources. A reevaluation, sampling at depth, and testing for possible extensions of the Table Mountain asbestos and chromium deposit should be undertaken in the light of recent interpretations regarding its geologic setting.

  6. Neurofeedback training for peak performance

    OpenAIRE

    Marek Graczyk; Maria Pąchalska; Artur Ziółkowski; Grzegorz Mańko; Beata Łukaszewska; Kazimierz Kochanowicz; Andrzej Mirski; Iurii D. Kropotov

    2014-01-01

    [b]aim[/b]. One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneou...

  7. Power peaking nuclear reliability factors

    International Nuclear Information System (INIS)

    Hassan, H.A.; Pegram, J.W.; Mays, C.W.; Romano, J.J.; Woods, J.J.; Warren, H.D.

    1977-11-01

    The Calculational Nuclear Reliability Factor (CNRF) assigned to the limiting power density calculated in reactor design has been determined. The CNRF is presented as a function of the relative power density of the fuel assembly and its radial local. In addition, the Measurement Nuclear Reliability Factor (MNRF) for the measured peak hot pellet power in the core has been evaluated. This MNRF is also presented as a function of the relative power density and radial local within the fuel assembly

  8. Evaluation of concurrent peak responses

    International Nuclear Information System (INIS)

    Wang, P.C.; Curreri, J.; Reich, M.

    1983-01-01

    This report deals with the problem of combining two or more concurrent responses which are induced by dynamic loads acting on nuclear power plant structures. Specifically, the acceptability of using the square root of the sum of the squares (SRSS) value of peak values as the combined response is investigated. Emphasis is placed on the establishment of a simplified criterion that is convenient and relatively easy to use by design engineers

  9. Finding two-dimensional peaks

    International Nuclear Information System (INIS)

    Silagadze, Z.K.

    2007-01-01

    Two-dimensional generalization of the original peak finding algorithm suggested earlier is given. The ideology of the algorithm emerged from the well-known quantum mechanical tunneling property which enables small bodies to penetrate through narrow potential barriers. We merge this 'quantum' ideology with the philosophy of Particle Swarm Optimization to get the global optimization algorithm which can be called Quantum Swarm Optimization. The functionality of the newborn algorithm is tested on some benchmark optimization problems

  10. Drivers of peak sales for pharmaceutical brands

    NARCIS (Netherlands)

    Fischer, Marc; Leeflang, Peter S. H.; Verhoef, Peter C.

    2010-01-01

    Peak sales are an important metric in the pharmaceutical industry. Specifically, managers are focused on the height-of-peak-sales and the time required achieving peak sales. We analyze how order of entry and quality affect the level of peak sales and the time-to-peak-sales of pharmaceutical brands.

  11. RFDR with Adiabatic Inversion Pulses: Application to Internuclear Distance Measurements

    International Nuclear Information System (INIS)

    Leppert, Joerg; Ohlenschlaeger, Oliver; Goerlach, Matthias; Ramachandran, Ramadurai

    2004-01-01

    In the context of the structural characterisation of biomolecular systems via MAS solid state NMR, the potential utility of homonuclear dipolar recoupling with adiabatic inversion pulses has been assessed via numerical simulations and experimental measurements. The results obtained suggest that it is possible to obtain reliable estimates of internuclear distances via an analysis of the initial cross-peak intensity buildup curves generated from two-dimensional adiabatic inversion pulse driven longitudinal magnetisation exchange experiments

  12. Limits to Nonlinear Inversion

    DEFF Research Database (Denmark)

    Mosegaard, Klaus

    2012-01-01

    For non-linear inverse problems, the mathematical structure of the mapping from model parameters to data is usually unknown or partly unknown. Absence of information about the mathematical structure of this function prevents us from presenting an analytical solution, so our solution depends on our......-heuristics are inefficient for large-scale, non-linear inverse problems, and that the 'no-free-lunch' theorem holds. We discuss typical objections to the relevance of this theorem. A consequence of the no-free-lunch theorem is that algorithms adapted to the mathematical structure of the problem perform more efficiently than...... pure meta-heuristics. We study problem-adapted inversion algorithms that exploit the knowledge of the smoothness of the misfit function of the problem. Optimal sampling strategies exist for such problems, but many of these problems remain hard. © 2012 Springer-Verlag....

  13. Inverse scale space decomposition

    DEFF Research Database (Denmark)

    Schmidt, Marie Foged; Benning, Martin; Schönlieb, Carola-Bibiane

    2018-01-01

    We investigate the inverse scale space flow as a decomposition method for decomposing data into generalised singular vectors. We show that the inverse scale space flow, based on convex and even and positively one-homogeneous regularisation functionals, can decompose data represented...... by the application of a forward operator to a linear combination of generalised singular vectors into its individual singular vectors. We verify that for this decomposition to hold true, two additional conditions on the singular vectors are sufficient: orthogonality in the data space and inclusion of partial sums...... of the subgradients of the singular vectors in the subdifferential of the regularisation functional at zero. We also address the converse question of when the inverse scale space flow returns a generalised singular vector given that the initial data is arbitrary (and therefore not necessarily in the range...

  14. Generalized inverses theory and computations

    CERN Document Server

    Wang, Guorong; Qiao, Sanzheng

    2018-01-01

    This book begins with the fundamentals of the generalized inverses, then moves to more advanced topics. It presents a theoretical study of the generalization of Cramer's rule, determinant representations of the generalized inverses, reverse order law of the generalized inverses of a matrix product, structures of the generalized inverses of structured matrices, parallel computation of the generalized inverses, perturbation analysis of the generalized inverses, an algorithmic study of the computational methods for the full-rank factorization of a generalized inverse, generalized singular value decomposition, imbedding method, finite method, generalized inverses of polynomial matrices, and generalized inverses of linear operators. This book is intended for researchers, postdocs, and graduate students in the area of the generalized inverses with an undergraduate-level understanding of linear algebra.

  15. Some results on inverse scattering

    International Nuclear Information System (INIS)

    Ramm, A.G.

    2008-01-01

    A review of some of the author's results in the area of inverse scattering is given. The following topics are discussed: (1) Property C and applications, (2) Stable inversion of fixed-energy 3D scattering data and its error estimate, (3) Inverse scattering with 'incomplete' data, (4) Inverse scattering for inhomogeneous Schroedinger equation, (5) Krein's inverse scattering method, (6) Invertibility of the steps in Gel'fand-Levitan, Marchenko, and Krein inversion methods, (7) The Newton-Sabatier and Cox-Thompson procedures are not inversion methods, (8) Resonances: existence, location, perturbation theory, (9) Born inversion as an ill-posed problem, (10) Inverse obstacle scattering with fixed-frequency data, (11) Inverse scattering with data at a fixed energy and a fixed incident direction, (12) Creating materials with a desired refraction coefficient and wave-focusing properties. (author)

  16. Spatial peak-load pricing

    International Nuclear Information System (INIS)

    Arellano, M. Soledad; Serra, Pablo

    2007-01-01

    This article extends the traditional electricity peak-load pricing model to include transmission costs. In the context of a two-node, two-technology electric power system, where suppliers face inelastic demand, we show that when the marginal plant is located at the energy-importing center, generators located away from that center should pay the marginal capacity transmission cost; otherwise, consumers should bear this cost through capacity payments. Since electric power transmission is a natural monopoly, marginal-cost pricing does not fully cover costs. We propose distributing the revenue deficit among users in proportion to the surplus they derive from the service priced at marginal cost. (Author)

  17. Influenza Seasonal Summary, 2014-2015 Season

    Science.gov (United States)

    2015-08-14

    Influenza Seasonal Summarv 2014-2015 Season EpiData Center Department Communicable Disease Division NMCPHC-EDC-TR-394-2015 REPORT DOCUMENTATION... Influenza Seasonal Summary, 2014-2015 Season Sb. GRANT NUMBER $c. PROGRAM ELEMENT NUMBER 6. AUTHORjS) Sd. PROJECT NUMBER Ashleigh K McCabe, Kristen R...SUPPLEMENTARY NOTES 1<l. ABSTRACT This report summartzes influenza activity among Department of Navy (DON) and Depar1ment of Defense (DOD

  18. Seasonality, mobility, and livability.

    Science.gov (United States)

    2012-01-31

    Signature project 4a, Seasonality, Mobility, and Livability investigated the effects of weather, season, built environment, community amenities, attitudes, and demographics on mobility and quality of life (QOL). A four season panel survey exami...

  19. Economic effects of peak oil

    International Nuclear Information System (INIS)

    Lutz, Christian; Lehr, Ulrike; Wiebe, Kirsten S.

    2012-01-01

    Assuming that global oil production peaked, this paper uses scenario analysis to show the economic effects of a possible supply shortage and corresponding rise in oil prices in the next decade on different sectors in Germany and other major economies such as the US, Japan, China, the OPEC or Russia. Due to the price-inelasticity of oil demand the supply shortage leads to a sharp increase in oil prices in the second scenario, with high effects on GDP comparable to the magnitude of the global financial crises in 2008/09. Oil exporting countries benefit from high oil prices, whereas oil importing countries are negatively affected. Generally, the effects in the third scenario are significantly smaller than in the second, showing that energy efficiency measures and the switch to renewable energy sources decreases the countries' dependence on oil imports and hence reduces their vulnerability to oil price shocks on the world market. - Highlights: ► National and sectoral economic effects of peak oil until 2020 are modelled. ► The price elasticity of oil demand is low resulting in high price fluctuations. ► Oil shortage strongly affects transport and indirectly all other sectors. ► Global macroeconomic effects are comparable to the 2008/2009 crisis. ► Country effects depend on oil imports and productivity, and economic structures.

  20. A new record peak luminosity for the LHC

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Two weeks of dedicated machine development paid off last weekend when the LHC ran for physics with three nominal intensity (∼1011 protons) bunches in each beam.   This brought a new record peak luminosity of around 8×1029 cm-2 s-1, and allowed the LHC to double the integrated luminosity delivered to the experiments since 30 March from 16 to 32 inverse nanobarns over the weekend. After a few more fills in this configuration, the number of bunches will be raised to six per beam, which will in turn allow the peak luminosity to break the 1030 cm-2 s-1 barrier for the first time, well on the way to achieving the 2010 objective of 1032 cm-2 s-1. This peak luminosity goal requires 800 nominal bunches per beam squeezed to a beta of 3.5 metres. The plan for 2011 is to run the LHC in this configuration over about 10 months, thus achieving the objective of recording one inverse femtobarn of data in total. The machine development period also allowed the TOTEM detectors to be set up with 45...

  1. Inversion assuming weak scattering

    DEFF Research Database (Denmark)

    Xenaki, Angeliki; Gerstoft, Peter; Mosegaard, Klaus

    2013-01-01

    due to the complex nature of the field. A method based on linear inversion is employed to infer information about the statistical properties of the scattering field from the obtained cross-spectral matrix. A synthetic example based on an active high-frequency sonar demonstrates that the proposed...

  2. Bayesian seismic AVO inversion

    Energy Technology Data Exchange (ETDEWEB)

    Buland, Arild

    2002-07-01

    A new linearized AVO inversion technique is developed in a Bayesian framework. The objective is to obtain posterior distributions for P-wave velocity, S-wave velocity and density. Distributions for other elastic parameters can also be assessed, for example acoustic impedance, shear impedance and P-wave to S-wave velocity ratio. The inversion algorithm is based on the convolutional model and a linearized weak contrast approximation of the Zoeppritz equation. The solution is represented by a Gaussian posterior distribution with explicit expressions for the posterior expectation and covariance, hence exact prediction intervals for the inverted parameters can be computed under the specified model. The explicit analytical form of the posterior distribution provides a computationally fast inversion method. Tests on synthetic data show that all inverted parameters were almost perfectly retrieved when the noise approached zero. With realistic noise levels, acoustic impedance was the best determined parameter, while the inversion provided practically no information about the density. The inversion algorithm has also been tested on a real 3-D dataset from the Sleipner Field. The results show good agreement with well logs but the uncertainty is high. The stochastic model includes uncertainties of both the elastic parameters, the wavelet and the seismic and well log data. The posterior distribution is explored by Markov chain Monte Carlo simulation using the Gibbs sampler algorithm. The inversion algorithm has been tested on a seismic line from the Heidrun Field with two wells located on the line. The uncertainty of the estimated wavelet is low. In the Heidrun examples the effect of including uncertainty of the wavelet and the noise level was marginal with respect to the AVO inversion results. We have developed a 3-D linearized AVO inversion method with spatially coupled model parameters where the objective is to obtain posterior distributions for P-wave velocity, S

  3. Calculation of the inverse data space via sparse inversion

    KAUST Repository

    Saragiotis, Christos

    2011-01-01

    The inverse data space provides a natural separation of primaries and surface-related multiples, as the surface multiples map onto the area around the origin while the primaries map elsewhere. However, the calculation of the inverse data is far from trivial as theory requires infinite time and offset recording. Furthermore regularization issues arise during inversion. We perform the inversion by minimizing the least-squares norm of the misfit function by constraining the $ell_1$ norm of the solution, being the inverse data space. In this way a sparse inversion approach is obtained. We show results on field data with an application to surface multiple removal.

  4. Inversion of Solid Earth's Varying Shape 2: Using Self-Consistency to Infer Static Ocean Topography

    Science.gov (United States)

    Blewitt, G.; Clarke, P. J.

    2002-12-01

    We have developed a spectral approach to invert for the redistribution of mass on the Earth's surface given precise global geodetic measurements of the solid Earth's geometrical shape. We used the elastic load Love number formalism to characterize the redistributed mass as a spherical harmonic expansion, truncated at some degree and order n. [Clarke and Blewitt, this meeting]. Here we incorporate the additional physical constraint that the sea surface in hydrostatic equilibrium corresponds to an equipotential surface, to infer the non-steric component of static ocean topography. Our model rigorously accounts for self-gravitation of the ocean, continental surface mass, and the deformed solid Earth, such that the sea surface adopts a new equipotential surface consistent with ocean-land mass exchange, deformation of the geoid, deformation of the sea floor, and the geographical configuration of the oceans and continents. We develop a self-consistent spectral inversion method to solve for the distribution of continental surface mass that would generate geographic variations in relative mean sea level such that the total (ocean plus continental) mass distribution agrees with the original geodetic estimates to degree and order n. We apply this theory to study the contribution of seasonal inter-hemispheric (degree-1) mass transfer to seasonal variation in static ocean topography, using a published empirical seasonal model for degree-1 surface loading derived using GPS coordinate time series from the global IGS network [Blewitt et al., Science 294, 2,342-2,345, 2001]. The resulting predictions of seasonal variations of relative sea level strongly depend on location, with peak variations ranging from 3 mm to 19 mm. The largest peak variations are predicted in mid-August around Antarctica and the southern hemisphere in general; the lowest variations are predicted in the northern hemisphere. Corresponding maximum continental loading occurs in Canada and Siberia at the water

  5. Preparing for the Season (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    Flu season starts in the fall and goes through the spring, typically peaking between January and March in the United States. In this podcast, Dr. Joe Bresee discusses the importance of getting vaccinated against the flu every year.

  6. Peaking for optimal performance: Research limitations and future directions.

    Science.gov (United States)

    Pyne, David B; Mujika, Iñigo; Reilly, Thomas

    2009-02-01

    A key element of the physical preparation of athletes is the taper period in the weeks immediately preceding competition. Existing research has defined the taper, identified various forms used in contemporary sport, and examined the prescription of training volume, load, intensity, duration, and type (progressive or step). Current limitations include: the lack of studies on team, combative, racquet, and precision (target) sports; the relatively small number of randomized controlled trials; the narrow focus on a single competition (single peak) compared with multiple peaking for weekly, multi-day or multiple events; and limited understanding of the physiological, neuromuscular, and biomechanical basis of the taper. Future research should address these limitations, together with the influence of prior training on optimal tapering strategies, and the interactions between the taper and long-haul travel, heat, and altitude. Practitioners seek information on how to prescribe tapers from season to season during an athlete's career, or a team's progression through a domestic league season, or multi-year Olympic or World Cup cycle. Practical guidelines for planning effective tapers for the Vancouver 2010 and London 2012 Olympics will evolve from both experimental investigations and modelling of successful tapers currently employed in a wide range of sports.

  7. Enhanced vegetation growth peak and its key mechanisms

    Science.gov (United States)

    Huang, K.; Xia, J.; Wang, Y.; Ahlström, A.; Schwalm, C.; Huntzinger, D. N.; Chen, J.; Cook, R. B.; Fang, Y.; Fisher, J. B.; Jacobson, A. R.; Michalak, A.; Schaefer, K. M.; Wei, Y.; Yan, L.; Luo, Y.

    2017-12-01

    It remains unclear that whether and how the vegetation growth peak has been shifted globally during the past three decades. Here we used two global datasets of gross primary productivity (GPP) and a satellite-derived Normalized Difference Vegetation Index (NDVI) to characterize recent changes in seasonal peak vegetation growth. The attribution of changes in peak growth to their driving factors was examined with several datasets. We demonstrated that the growth peak of global vegetation has been linearly increasing during the past three decades. About 65% of this trend is evenly explained by the expanding croplands (21%), rising atmospheric [CO2] (22%), and intensifying nitrogen deposition (22%). The contribution of expanding croplands to the peak growth trend was substantiated by measurements from eddy-flux towers, sun-induced chlorophyll fluorescence and a global database of plant traits, all of which demonstrated that croplands have a higher photosynthetic capacity than other vegetation types. The contribution of rising atmospheric [CO2] and nitrogen deposition are consistent with the positive response of leaf growth to elevated [CO2] (25%) and nitrogen addition (8%) from 346 manipulated experiments. The positive effect of rising atmospheric [CO2] was also well captured by 15 terrestrial biosphere models. However, most models underestimated the contributions of land-cover change and nitrogen deposition, but overestimated the positive effect of climate change.

  8. Electrochemically driven emulsion inversion

    Science.gov (United States)

    Johans, Christoffer; Kontturi, Kyösti

    2007-09-01

    It is shown that emulsions stabilized by ionic surfactants can be inverted by controlling the electrical potential across the oil-water interface. The potential dependent partitioning of sodium dodecyl sulfate (SDS) was studied by cyclic voltammetry at the 1,2-dichlorobenzene|water interface. In the emulsion the potential control was achieved by using a potential-determining salt. The inversion of a 1,2-dichlorobenzene-in-water (O/W) emulsion stabilized by SDS was followed by conductometry as a function of added tetrapropylammonium chloride. A sudden drop in conductivity was observed, indicating the change of the continuous phase from water to 1,2-dichlorobenzene, i.e. a water-in-1,2-dichlorobenzene emulsion was formed. The inversion potential is well in accordance with that predicted by the hydrophilic-lipophilic deviation if the interfacial potential is appropriately accounted for.

  9. Influence of peak flow changes on the macroinvertebrate drift downstream of a Brazilian hydroelectric dam.

    Science.gov (United States)

    Castro, D M P; Hughes, R M; Callisto, M

    2013-11-01

    Successive daily peak flows from hydropower plants can disrupt aquatic ecosystems and alter the composition and structure of macroinvertebrates downstream. We evaluated the influence of peak flow changes on macroinvertebrate drift downstream of a hydroelectric plant as a basis for determining ecological flows that might reduce the disturbance of aquatic biota. The aim of this study was to assess the influence of flow fluctuations on the seasonal and daily drift patterns of macroinvertebrates. We collected macroinvertebrates during fixed flow rates (323 m3.s-1 in the wet season and 111 m3.s-1 in the dry season) and when peak flows fluctuated (378 to 481 m3.s-1 in the wet season, and 109 to 173 m3.s-1 in the dry season) in 2010. We collected 31,924 organisms belonging to 46 taxa in the four sampling periods. Taxonomic composition and densities of drifting invertebrates differed between fixed and fluctuating flows, in both wet and dry seasons, but family richness varied insignificantly. We conclude that macroinvertebrate assemblages downstream of dams are influenced by daily peak flow fluctuations. When making environmental flow decisions for dams, it would be wise to consider drifting macroinvertebrates because they reflect ecological changes in downstream biological assemblages.

  10. Channelling versus inversion

    DEFF Research Database (Denmark)

    Gale, A.S.; Surlyk, Finn; Anderskouv, Kresten

    2013-01-01

    Evidence from regional stratigraphical patterns in Santonian−Campanian chalk is used to infer the presence of a very broad channel system (5 km across) with a depth of at least 50 m, running NNW−SSE across the eastern Isle of Wight; only the western part of the channel wall and fill is exposed. W......−Campanian chalks in the eastern Isle of Wight, involving penecontemporaneous tectonic inversion of the underlying basement structure, are rejected....

  11. Reactivity in inverse micelles

    International Nuclear Information System (INIS)

    Brochette, Pascal

    1987-01-01

    This research thesis reports the study of the use of micro-emulsions of water in oil as reaction support. Only the 'inverse micelles' domain of the ternary mixing (water/AOT/isooctane) has been studied. The main addressed issues have been: the micro-emulsion disturbance in presence of reactants, the determination of reactant distribution and the resulting kinetic theory, the effect of the interface on electron transfer reactions, and finally protein solubilization [fr

  12. Inverse transition radiation

    International Nuclear Information System (INIS)

    Steinhauer, L.C.; Romea, R.D.; Kimura, W.D.

    1997-01-01

    A new method for laser acceleration is proposed based upon the inverse process of transition radiation. The laser beam intersects an electron-beam traveling between two thin foils. The principle of this acceleration method is explored in terms of its classical and quantum bases and its inverse process. A closely related concept based on the inverse of diffraction radiation is also presented: this concept has the significant advantage that apertures are used to allow free passage of the electron beam. These concepts can produce net acceleration because they do not satisfy the conditions in which the Lawson-Woodward theorem applies (no net acceleration in an unbounded vacuum). Finally, practical aspects such as damage limits at optics are employed to find an optimized set of parameters. For reasonable assumptions an acceleration gradient of 200 MeV/m requiring a laser power of less than 1 GW is projected. An interesting approach to multi-staging the acceleration sections is also presented. copyright 1997 American Institute of Physics

  13. Intersections, ideals, and inversion

    International Nuclear Information System (INIS)

    Vasco, D.W.

    1998-01-01

    Techniques from computational algebra provide a framework for treating large classes of inverse problems. In particular, the discretization of many types of integral equations and of partial differential equations with undetermined coefficients lead to systems of polynomial equations. The structure of the solution set of such equations may be examined using algebraic techniques.. For example, the existence and dimensionality of the solution set may be determined. Furthermore, it is possible to bound the total number of solutions. The approach is illustrated by a numerical application to the inverse problem associated with the Helmholtz equation. The algebraic methods are used in the inversion of a set of transverse electric (TE) mode magnetotelluric data from Antarctica. The existence of solutions is demonstrated and the number of solutions is found to be finite, bounded from above at 50. The best fitting structure is dominantly one dimensional with a low crustal resistivity of about 2 ohm-m. Such a low value is compatible with studies suggesting lower surface wave velocities than found in typical stable cratons

  14. Intersections, ideals, and inversion

    Energy Technology Data Exchange (ETDEWEB)

    Vasco, D.W.

    1998-10-01

    Techniques from computational algebra provide a framework for treating large classes of inverse problems. In particular, the discretization of many types of integral equations and of partial differential equations with undetermined coefficients lead to systems of polynomial equations. The structure of the solution set of such equations may be examined using algebraic techniques.. For example, the existence and dimensionality of the solution set may be determined. Furthermore, it is possible to bound the total number of solutions. The approach is illustrated by a numerical application to the inverse problem associated with the Helmholtz equation. The algebraic methods are used in the inversion of a set of transverse electric (TE) mode magnetotelluric data from Antarctica. The existence of solutions is demonstrated and the number of solutions is found to be finite, bounded from above at 50. The best fitting structure is dominantly onedimensional with a low crustal resistivity of about 2 ohm-m. Such a low value is compatible with studies suggesting lower surface wave velocities than found in typical stable cratons.

  15. Testing earthquake source inversion methodologies

    KAUST Repository

    Page, Morgan T.; Mai, Paul Martin; Schorlemmer, Danijel

    2011-01-01

    Source Inversion Validation Workshop; Palm Springs, California, 11-12 September 2010; Nowadays earthquake source inversions are routinely performed after large earthquakes and represent a key connection between recorded seismic and geodetic data

  16. Differences in Influenza Seasonality by Latitude, Northern India

    Science.gov (United States)

    Broor, Shobha; Saha, Siddhartha; Barnes, John; Smith, Catherine; Shaw, Michael; Chadha, Mandeep; Lal, Renu B.

    2014-01-01

    The seasonality of influenza in the tropics complicates vaccination timing. We investigated influenza seasonality in northern India and found influenza positivity peaked in Srinagar (34.09°N) in January–March but peaked in New Delhi (28.66°N) in July–September. Srinagar should consider influenza vaccination in October–November, but New Delhi should vaccinate in May–June. PMID:25279651

  17. Establishment of peak bone mass.

    Science.gov (United States)

    Mora, Stefano; Gilsanz, Vicente

    2003-03-01

    Among the main areas of progress in osteoporosis research during the last decade or so are the general recognition that this condition, which is the cause of so much pain in the elderly population, has its antecedents in childhood and the identification of the structural basis accounting for much of the differences in bone strength among humans. Nevertheless, current understanding of the bone mineral accrual process is far from complete. The search for genes that regulate bone mass acquisition is ongoing, and current results are not sufficient to identify subjects at risk. However, there is solid evidence that BMD measurements can be helpful for the selection of subjects that presumably would benefit from preventive interventions. The questions regarding the type of preventive interventions, their magnitude, and duration remain unanswered. Carefully designed controlled trials are needed. Nevertheless, previous experience indicates that weight-bearing activity and possibly calcium supplements are beneficial if they are begun during childhood and preferably before the onset of puberty. Modification of unhealthy lifestyles and increments in exercise or calcium assumption are logical interventions that should be implemented to improve bone mass gains in all children and adolescents who are at risk of failing to achieve an optimal peak bone mass.

  18. Neurofeedback training for peak performance

    Directory of Open Access Journals (Sweden)

    Marek Graczyk

    2014-11-01

    Full Text Available [b]aim[/b]. One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneous EEG and event related potentials (ERPs. [b]case study[/b]. The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by error measurement were observed in the patient. [b]conclusion[/b]. Neurofeedback training in the subject under study increased the amplitude of the monitoring component of ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex. Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance.

  19. Reactor power peaking information display

    International Nuclear Information System (INIS)

    Book, T.L.; Kochendarfer, R.A.

    1986-01-01

    This patent describes a system for monitoring operating conditions within a nuclear reactor. The system consists of a method for measuring the operating parameters within the nuclear reactor, including the position of axial power shaping rods and regulating control rod. It also includes a method for determining from the operating parameters the operating limits before a power peaking condition exists within the nuclear reactor, and a method for displaying the operating limits which consists of a visual display permitting the continuous monitoring of the operating conditions within the nuclear reactor as a graph of the shaping rod position vs the regulating rod position having a permissible area and a restricted area. The permissible area is further divided into a recommended operating area for steady state operation and a cursor located on the graph to indicate the present operating condition of the nuclear reactor to allow an operator to view any need for corrective action based on the movement of the cursor out of the recommended operating area and to take any corrective transient action within the permissible area

  20. Neurofeedback training for peak performance.

    Science.gov (United States)

    Graczyk, Marek; Pąchalska, Maria; Ziółkowski, Artur; Mańko, Grzegorz; Łukaszewska, Beata; Kochanowicz, Kazimierz; Mirski, Andrzej; Kropotov, Iurii D

    2014-01-01

    One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneous EEG and event related potentials (ERPs). The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by error measurement were observed in the patient. Neurofeedback training in the subject under study increased the amplitude of the monitoring component of ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex. Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance.

  1. Recent Changes in the Arctic Melt Season

    Science.gov (United States)

    Stroeve, Julienne; Markus, Thorsten; Meier, Walter N.; Miller, Jeff

    2007-01-01

    Melt-season duration, melt-onset and freeze-up dates are derived from satellite passive microwave data and analyzed from 1979 to 2005 over Arctic sea ice. Results indicate a shift towards a longer melt season, particularly north of Alaska and Siberia, corresponding to large retreats of sea ice observed in these regions. Although there is large interannual and regional variability in the length of the melt season, the Arctic is experiencing an overall lengthening of the melt season at a rate of about 2 weeks decade(sup -1). In fact, all regions in the Arctic (except for the central Arctic) have statistically significant (at the 99% level or higher) longer melt seasons by greater than 1 week decade(sup -1). The central Arctic shows a statistically significant trend (at the 98% level) of 5.4 days decade(sup -1). In 2005 the Arctic experienced its longest melt season, corresponding with the least amount of sea ice since 1979 and the warmest temperatures since the 1880s. Overall, the length of the melt season is inversely correlated with the lack of sea ice seen in September north of Alaska and Siberia, with a mean correlation of -0.8.

  2. Research Opportunities at Storm Peak Laboratory

    Science.gov (United States)

    Hallar, A. G.; McCubbin, I. B.

    2006-12-01

    The Desert Research Institute (DRI) operates a high elevation facility, Storm Peak Laboratory (SPL), located on the west summit of Mt. Werner in the Park Range near Steamboat Springs, Colorado at an elevation of 3210 m MSL (Borys and Wetzel, 1997). SPL provides an ideal location for long-term research on the interactions of atmospheric aerosol and gas- phase chemistry with cloud and natural radiation environments. The ridge-top location produces almost daily transition from free tropospheric to boundary layer air which occurs near midday in both summer and winter seasons. Long-term observations at SPL document the role of orographically induced mixing and convection on vertical pollutant transport and dispersion. During winter, SPL is above cloud base 25% of the time, providing a unique capability for studying aerosol-cloud interactions (Borys and Wetzel, 1997). A comprehensive set of continuous aerosol measurements was initiated at SPL in 2002. SPL includes an office-type laboratory room for computer and instrumentation setup with outside air ports and cable access to the roof deck, a cold room for precipitation and cloud rime ice sample handling and ice crystal microphotography, a 150 m2 roof deck area for outside sampling equipment, a full kitchen and two bunk rooms with sleeping space for nine persons. The laboratory is currently well equipped for aerosol and cloud measurements. Particles are sampled from an insulated, 15 cm diameter manifold within approximately 1 m of its horizontal entry point through an outside wall. The 4 m high vertical section outside the building is capped with an inverted can to exclude large particles.

  3. Signature of inverse Compton emission from blazars

    Science.gov (United States)

    Gaur, Haritma; Mohan, Prashanth; Wierzcholska, Alicja; Gu, Minfeng

    2018-01-01

    Blazars are classified into high-, intermediate- and low-energy-peaked sources based on the location of their synchrotron peak. This lies in infra-red/optical to ultra-violet bands for low- and intermediate-peaked blazars. The transition from synchrotron to inverse Compton emission falls in the X-ray bands for such sources. We present the spectral and timing analysis of 14 low- and intermediate-energy-peaked blazars observed with XMM-Newton spanning 31 epochs. Parametric fits to X-ray spectra help constrain the possible location of transition from the high-energy end of the synchrotron to the low-energy end of the inverse Compton emission. In seven sources in our sample, we infer such a transition and constrain the break energy in the range 0.6-10 keV. The Lomb-Scargle periodogram is used to estimate the power spectral density (PSD) shape. It is well described by a power law in a majority of light curves, the index being flatter compared to general expectation from active galactic nuclei, ranging here between 0.01 and 1.12, possibly due to short observation durations resulting in an absence of long-term trends. A toy model involving synchrotron self-Compton and external Compton (EC; disc, broad line region, torus) mechanisms are used to estimate magnetic field strength ≤0.03-0.88 G in sources displaying the energy break and infer a prominent EC contribution. The time-scale for variability being shorter than synchrotron cooling implies steeper PSD slopes which are inferred in these sources.

  4. Introduction to Schroedinger inverse scattering

    International Nuclear Information System (INIS)

    Roberts, T.M.

    1991-01-01

    Schroedinger inverse scattering uses scattering coefficients and bound state data to compute underlying potentials. Inverse scattering has been studied extensively for isolated potentials q(x), which tend to zero as vertical strokexvertical stroke→∞. Inverse scattering for isolated impurities in backgrounds p(x) that are periodic, are Heaviside steps, are constant for x>0 and periodic for x<0, or that tend to zero as x→∞ and tend to ∞ as x→-∞, have also been studied. This paper identifies literature for the five inverse problems just mentioned, and for four other inverse problems. Heaviside-step backgrounds are discussed at length. (orig.)

  5. Contribution to performing gas solutions and the complementarity of energies to address electric peak consumptions

    International Nuclear Information System (INIS)

    2015-01-01

    This article aims at outlining the contribution that gas-based solutions may have for the reduction of the seasonal electricity peak consumption. After having recalled the principles related to electricity peak consumption (daily peak in summer and in winter due to the use of various equipment which lasts few hours, seasonal peak in winter due to the use of electric heating which may last several weeks) and the associated evolution of electricity consumptions over the last years, this article describes the main challenges related to the electric peak consumption: how to maintain the balance in real time between production and consumption. In France, the network manager must use, beside nuclear power stations, thermal productions (gas or coal-based) which result in higher CO 2 emissions. Electricity imports from Germany also degrade the French carbon footprint. Thus, the management of daily and seasonal peaks can be based on three levers of action: to act on supply by developing capacities to face the residual peak, to act on demand by smoothing the load curve by controlling the load of electric equipment, or to act on demand by a global reduction of the thermo-sensitive consumption of electricity

  6. Seasonal cycles of pelagic production and consumption

    Science.gov (United States)

    Longhurst, Alan

    Comprehensive seasonal cycles of production and consumption in the pelagial require the ocean to be partitioned. This can be done rationally at two levels: into four primary ecological domains (three oceanic and one coastal), or about fifty biogeochemical provinces. The domains differ in their characteristic seasonal cycles of stability, nutrient supply and illumination, while provinces are defined by ocean currents, fronts, topography and recurrent features in the sea surface chlorophyll field. For each of these compartments, seasonal cycles of photic depth, primary production and accumulation (or loss) of algal biomass were obtained from the climatological CZCS chlorophyll field and other data and these, together with mixed layer depths, rendered characteristic seasonal cycles of production and consumption, which can be grouped into eight models: i - polar irradiance-mediated production peak; ii - nutrient-limited spring production peak; iii - winter-spring production with nutrient limitation; iv - small amplitude response to trade wind seasonality; v - large amplitude response to monsoon reversal; vi - canonical spring-fall blooms of mid-latitude continental shelves; vii - topography-forced summer production; viii - intermittent production at coastal divergences. For higher latitudes, these models suggest that the observed late-summer ‘blooms’ result not from a renewal of primary production rate, but from a relaxation of grazing pressure; in mid-latitudes, the observed ‘winter’ bloom represents chlorophyll accumulation at a season when loss terms are apparently smaller than during the period of peak primary production rate which occurs later, in spring. Where an episodic seasonal increase in rate of primary production occurs, as in the Arabian Sea, algal biomass accumulation may brief, lasting only until consumption is fully re-established. Only in the low latitude oligotrophic ocean are production and consumption perennially and closely coupled.

  7. Inverse carbon dioxide flux estimates for the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Meesters, A.G.C.A.; Tolk, L.F.; Dolman, A.J. [Faculty of Earth and Life Sciences, VU University, Amsterdam (Netherlands); Peters, W.; Hutjes, R.W.A.; Vellinga, O.S.; Elbers, J.A. [Department Meteorology and Air Quality, Wageningen University and Research Centre, Wageningen (Netherlands); Vermeulen, A.T. [Biomass, Coal and Environmental Research, Energy research Center of the Netherlands ECN, Petten (Netherlands); Van der Laan, S.; Neubert, R.E.M.; Meijer, H.A.J. [Centre for Isotope Research, Energy and Sustainability Research Institute Groningen, University of Groningen, Groningen (Netherlands)

    2012-10-26

    CO2 fluxes for the Netherlands and surroundings are estimated for the year 2008, from concentration measurements at four towers, using an inverse model. The results are compared to direct CO2 flux measurements by aircraft, for 6 flight tracks over the Netherlands, flown multiple times in each season. We applied the Regional Atmospheric Mesoscale Modeling system (RAMS) coupled to a simple carbon flux scheme (including fossil fuel), which was run at 10 km resolution, and inverted with an Ensemble Kalman Filter. The domain had 6 eco-regions, and inversions were performed for the four seasons separately. Inversion methods with pixel-dependent and -independent parameters for each eco-region were compared. The two inversion methods, in general, yield comparable flux averages for each eco-region and season, whereas the difference from the prior flux may be large. Posterior fluxes co-sampled along the aircraft flight tracks are usually much closer to the observations than the priors, with a comparable performance for both inversion methods, and with best performance for summer and autumn. The inversions showed more negative CO2 fluxes than the priors, though the latter are obtained from a biosphere model optimized using the Fluxnet database, containing observations from more than 200 locations worldwide. The two different crop ecotypes showed very different CO2 uptakes, which was unknown from the priors. The annual-average uptake is practically zero for the grassland class and for one of the cropland classes, whereas the other cropland class had a large net uptake, possibly because of the abundance of maize there.

  8. Inverse Faraday Effect Revisited

    Science.gov (United States)

    Mendonça, J. T.; Ali, S.; Davies, J. R.

    2010-11-01

    The inverse Faraday effect is usually associated with circularly polarized laser beams. However, it was recently shown that it can also occur for linearly polarized radiation [1]. The quasi-static axial magnetic field by a laser beam propagating in plasma can be calculated by considering both the spin and the orbital angular momenta of the laser pulse. A net spin is present when the radiation is circularly polarized and a net orbital angular momentum is present if there is any deviation from perfect rotational symmetry. This orbital angular momentum has recently been discussed in the plasma context [2], and can give an additional contribution to the axial magnetic field, thus enhancing or reducing the inverse Faraday effect. As a result, this effect that is usually attributed to circular polarization can also be excited by linearly polarized radiation, if the incident laser propagates in a Laguerre-Gauss mode carrying a finite amount of orbital angular momentum.[4pt] [1] S. ALi, J.R. Davies and J.T. Mendonca, Phys. Rev. Lett., 105, 035001 (2010).[0pt] [2] J. T. Mendonca, B. Thidé, and H. Then, Phys. Rev. Lett. 102, 185005 (2009).

  9. Secular trends in seasonal variation in birth weight

    DEFF Research Database (Denmark)

    Jensen, Camilla Bjørn; Gamborg, M; Raymond, K

    2015-01-01

    and phase of the yearly cycles to change. RESULTS: There was a clear seasonal pattern in BW which, however, changed gradually across the study period. The highest BWs were seen during fall (September - October) from 1936 to 1963, but a new peak gradually grew from the early 1940s during early summer (May...... again. Sunshine did not explain the seasonal variation in BW. CONCLUSION: There was a clear seasonal pattern in BW in Denmark 1936-1989, which however changed across the study period. Throughout the study period we observed a peak in BW during the fall, but gradually, starting in the early 1940s...

  10. Sorting Out Seasonal Allergies

    Science.gov (United States)

    ... Close ‹ Back to Healthy Living Sorting Out Seasonal Allergies Sneezing, runny nose, nasal congestion. Symptoms of the ... How do I know if I have seasonal allergies? According to Dr. Georgeson, the best way to ...

  11. Seasonal variability in CDOM absorption and fluorescence properties in the Barataria Basin, Louisiana, USA.

    Science.gov (United States)

    Singh, Shatrughan; D'Sa, Eurico; Swenson, Erick

    2010-01-01

    Absorption and fluorescence properties of chromophoric dissolved organic matter (CDOM) along a 124 km transect in the Barataria Basin, a large estuary located in Louisiana, USA, were investigated during high and low flow periods of the Mississippi River in the spring and winter of 2008-2009. Mean CDOM absorption at 355 nm from the marine to the freshwater end member stations ranged from (3.25 +/- 0.56) to (20.76 +/- 2.43) m(-1) for the three month high flow period whereas it varied from (1.48 +/- 1.08) to (25.45 +/- 7.03) m(-1) for the same stations during low flow period. Corresponding salinity values at these stations indicated the influence of river and shelf exchanges in the lower basin and precipitation and runoff in the upper basin. An inverse relationship of CDOM absorbance and fluorescence with salinity observed in the basin could be a useful indicator of salinity. CDOM fluorescence also varied over a large range showing an approximately 8 to 12-fold increase between the marine and freshwater end members for the two flow seasons. Excitation-emission matrix spectral plots indicated the presence of various fluorescence components with highest being the A-peak, lowest the T-peak, and the C and M-peaks showing similar trends along the transect. During low flow season the A/C ratio were well correlated with station locations indicating increased terrestrial influence towards the upper basin. CDOM absorption and fluorescence at 355 nm were highly correlated and independent of CDOM sources suggesting that fluorescence could be used to characterize CDOM in the basin.

  12. Seasonal Allergies (Hay Fever)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Seasonal Allergies (Hay Fever) KidsHealth / For Parents / Seasonal Allergies (Hay ... español Alergia estacional (fiebre del heno) About Seasonal Allergies "Achoo!" It's your son's third sneezing fit of ...

  13. Seasonal Variation in Epidemiology

    Science.gov (United States)

    Marrero, Osvaldo

    2013-01-01

    Seasonality analyses are important in medical research. If the incidence of a disease shows a seasonal pattern, then an environmental factor must be considered in its etiology. We discuss a method for the simultaneous analysis of seasonal variation in multiple groups. The nuts and bolts are explained using simple trigonometry, an elementary…

  14. Inverse fusion PCR cloning.

    Directory of Open Access Journals (Sweden)

    Markus Spiliotis

    Full Text Available Inverse fusion PCR cloning (IFPC is an easy, PCR based three-step cloning method that allows the seamless and directional insertion of PCR products into virtually all plasmids, this with a free choice of the insertion site. The PCR-derived inserts contain a vector-complementary 5'-end that allows a fusion with the vector by an overlap extension PCR, and the resulting amplified insert-vector fusions are then circularized by ligation prior transformation. A minimal amount of starting material is needed and experimental steps are reduced. Untreated circular plasmid, or alternatively bacteria containing the plasmid, can be used as templates for the insertion, and clean-up of the insert fragment is not urgently required. The whole cloning procedure can be performed within a minimal hands-on time and results in the generation of hundreds to ten-thousands of positive colonies, with a minimal background.

  15. Inverse plasma equilibria

    International Nuclear Information System (INIS)

    Hicks, H.R.; Dory, R.A.; Holmes, J.A.

    1983-01-01

    We illustrate in some detail a 2D inverse-equilibrium solver that was constructed to analyze tokamak configurations and stellarators (the latter in the context of the average method). To ensure that the method is suitable not only to determine equilibria, but also to provide appropriately represented data for existing stability codes, it is important to be able to control the Jacobian, tilde J is identical to delta(R,Z)/delta(rho, theta). The form chosen is tilde J = J 0 (rho)R/sup l/rho where rho is a flux surface label, and l is an integer. The initial implementation is for a fixed conducting-wall boundary, but the technique can be extended to a free-boundary model

  16. Short-term community dynamics in seasonal and hyperseasonal cerrados

    Directory of Open Access Journals (Sweden)

    MV. Cianciaruso

    Full Text Available In South America, the largest seasonal savanna region is the Brazilian cerrado. Our aim was to study temporal changes in some community descriptors, such as floristic composition, richness, species density, plant density, and cylindrical volume, in a seasonal cerrado, comparing it to a nearby hyperseasonal cerrado. In four different seasons, we placed randomly ten 1 m² quadrats in each vegetation form and sampled all the vascular plants. Seasonal changes in floristic composition, species density, and plant density were less pronounced in the seasonal than in the hyperseasonal cerrado. Floristic similarity between the vegetation forms was lower when the hyperseasonal cerrado was waterlogged. Richness and species density were higher in the seasonal cerrado, which reached its biomass peak at mid rainy season. The hyperseasonal cerrado, in turn, reached its biomass peak at early rainy season and, despite the waterlogging, maintained it until late rainy season. In the hyperseasonal cerrado, waterlogging acts as an environmental filter restricting the number of cerrado species able to withstand it. The seasonal cerrado community was more stable than the hyperseasonal one. Our results corroborated the idea that changes in the environmental filters will affect floristic composition and community structure in savannas.

  17. Transmuted Generalized Inverse Weibull Distribution

    OpenAIRE

    Merovci, Faton; Elbatal, Ibrahim; Ahmed, Alaa

    2013-01-01

    A generalization of the generalized inverse Weibull distribution so-called transmuted generalized inverse Weibull dis- tribution is proposed and studied. We will use the quadratic rank transmutation map (QRTM) in order to generate a flexible family of probability distributions taking generalized inverse Weibull distribution as the base value distribution by introducing a new parameter that would offer more distributional flexibility. Various structural properties including explicit expression...

  18. Determination of adsorption isotherms of chlorinated hydrocarbons on halloysite adsorbent by inverse gas chromatography.

    Science.gov (United States)

    Czech, K; Słomkiewicz, P M

    2013-05-03

    Inverse gas chromatographic methods of isotherm determination peak maximum (PM) and peak division (PD) were compared. These methods were applied to determine adsorption isotherms of dichloroethylene, trichloroethylene and tetrachloroethylene on acid-activated halloysite and adsorption enthalpy. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Calculation of the inverse data space via sparse inversion

    KAUST Repository

    Saragiotis, Christos; Doulgeris, Panagiotis C.; Verschuur, Dirk Jacob Eric

    2011-01-01

    The inverse data space provides a natural separation of primaries and surface-related multiples, as the surface multiples map onto the area around the origin while the primaries map elsewhere. However, the calculation of the inverse data is far from

  20. Inverse feasibility problems of the inverse maximum flow problems

    Indian Academy of Sciences (India)

    199–209. c Indian Academy of Sciences. Inverse feasibility problems of the inverse maximum flow problems. ADRIAN DEACONU. ∗ and ELEONOR CIUREA. Department of Mathematics and Computer Science, Faculty of Mathematics and Informatics, Transilvania University of Brasov, Brasov, Iuliu Maniu st. 50,. Romania.

  1. Seasonal Nitrogen Cycles on Pluto

    Science.gov (United States)

    Hansen, Candice J.; Paige, David A.

    1996-01-01

    A thermal model, developed to predict seasonal nitrogen cycles on Triton, has been modified and applied to Pluto. The model was used to calculate the partitioning of nitrogen between surface frost deposits and the atmosphere, as a function of time for various sets of input parameters. Volatile transport was confirmed to have a significant effect on Pluto's climate as nitrogen moved around on a seasonal time scale between hemispheres, and sublimed into and condensed out of the atmosphere. Pluto's high obliquity was found to have a significant effect on the distribution of frost on its surface. Conditions that would lead to permanent polar caps on Triton were found to lead to permanent zonal frost bands on Pluto. In some instances, frost sublimed from the middle of a seasonal cap outward, resulting in a "polar bald spot". Frost which was darker than the substrate did not satisfy observables on Pluto, in contrast to our findings for Triton. Bright frost (brighter than the substrate) came closer to matching observables. Atmospheric pressure varied seasonally. The amplitudes, and to a lesser extent the phase, of the variation depended significantly on frost and substrate properties. Atmospheric pressure was found to be determined both by Pluto's distance from the sun and by the subsolar latitude. In most cases two peaks in atmospheric pressure were observed annually: a greater one associated with the sublimation of the north polar cap just as Pluto receded from perihelion, and a lesser one associated with the sublimation of the south polar cap as Pluto approached perihelion. Our model predicted frost-free dark substrate surface temperatures in the 50 to 60 K range, while frost temperatures typically ranged between 30 to 40 K. Temporal changes in frost coverage illustrated by our results, and changes in the viewing geometry of Pluto from the Earth, may be important for interpretation of ground-based measurements of Pluto's thermal emission.

  2. Passive radio frequency peak power multiplier

    Science.gov (United States)

    Farkas, Zoltan D.; Wilson, Perry B.

    1977-01-01

    Peak power multiplication of a radio frequency source by simultaneous charging of two high-Q resonant microwave cavities by applying the source output through a directional coupler to the cavities and then reversing the phase of the source power to the coupler, thereby permitting the power in the cavities to simultaneously discharge through the coupler to the load in combination with power from the source to apply a peak power to the load that is a multiplication of the source peak power.

  3. Season of sampling and season of birth influence serotonin metabolite levels in human cerebrospinal fluid.

    Directory of Open Access Journals (Sweden)

    Jurjen J Luykx

    Full Text Available BACKGROUND: Animal studies have revealed seasonal patterns in cerebrospinal fluid (CSF monoamine (MA turnover. In humans, no study had systematically assessed seasonal patterns in CSF MA turnover in a large set of healthy adults. METHODOLOGY/PRINCIPAL FINDINGS: Standardized amounts of CSF were prospectively collected from 223 healthy individuals undergoing spinal anesthesia for minor surgical procedures. The metabolites of serotonin (5-hydroxyindoleacetic acid, 5-HIAA, dopamine (homovanillic acid, HVA and norepinephrine (3-methoxy-4-hydroxyphenylglycol, MPHG were measured using high performance liquid chromatography (HPLC. Concentration measurements by sampling and birth dates were modeled using a non-linear quantile cosine function and locally weighted scatterplot smoothing (LOESS, span = 0.75. The cosine model showed a unimodal season of sampling 5-HIAA zenith in April and a nadir in October (p-value of the amplitude of the cosine = 0.00050, with predicted maximum (PC(max and minimum (PC(min concentrations of 173 and 108 nmol/L, respectively, implying a 60% increase from trough to peak. Season of birth showed a unimodal 5-HIAA zenith in May and a nadir in November (p = 0.00339; PC(max = 172 and PC(min = 126. The non-parametric LOESS showed a similar pattern to the cosine in both season of sampling and season of birth models, validating the cosine model. A final model including both sampling and birth months demonstrated that both sampling and birth seasons were independent predictors of 5-HIAA concentrations. CONCLUSION: In subjects without mental illness, 5-HT turnover shows circannual variation by season of sampling as well as season of birth, with peaks in spring and troughs in fall.

  4. Practical load management - Peak shaving using photovoltaics

    International Nuclear Information System (INIS)

    Berger, W.

    2009-01-01

    This article takes a look at how photovoltaic (PV) power generation can be used in a practical way to meet peak demands for electricity. Advice is provided on how photovoltaics can provide peak load 'shaving' through the correlation between its production and the peak loads encountered during the day. The situation regarding feed-in tariffs in Italy is discussed, as are further examples of installations in Germany and Austria. Further, an initiative of the American Southern California Edison utility is discussed which foresees the installation of large PV plant on the roofs of commercial premises to provide local generation of peak energy and thus relieve demands on their power transportation network.

  5. The geomorphic structure of the runoff peak

    Directory of Open Access Journals (Sweden)

    R. Rigon

    2011-06-01

    Full Text Available This paper develops a theoretical framework to investigate the core dependence of peak flows on the geomorphic properties of river basins. Based on the theory of transport by travel times, and simple hydrodynamic characterization of floods, this new framework invokes the linearity and invariance of the hydrologic response to provide analytical and semi-analytical expressions for peak flow, time to peak, and area contributing to the peak runoff. These results are obtained for the case of constant-intensity hyetograph using the Intensity-Duration-Frequency (IDF curves to estimate extreme flow values as a function of the rainfall return period. Results show that, with constant-intensity hyetographs, the time-to-peak is greater than rainfall duration and usually shorter than the basin concentration time. Moreover, the critical storm duration is shown to be independent of rainfall return period as well as the area contributing to the flow peak. The same results are found when the effects of hydrodynamic dispersion are accounted for. Further, it is shown that, when the effects of hydrodynamic dispersion are negligible, the basin area contributing to the peak discharge does not depend on the channel velocity, but is a geomorphic propriety of the basin. As an example this framework is applied to three watersheds. In particular, the runoff peak, the critical rainfall durations and the time to peak are calculated for all links within a network to assess how they increase with basin area.

  6. [A peak recognition algorithm designed for chromatographic peaks of transformer oil].

    Science.gov (United States)

    Ou, Linjun; Cao, Jian

    2014-09-01

    In the field of the chromatographic peak identification of the transformer oil, the traditional first-order derivative requires slope threshold to achieve peak identification. In terms of its shortcomings of low automation and easy distortion, the first-order derivative method was improved by applying the moving average iterative method and the normalized analysis techniques to identify the peaks. Accurate identification of the chromatographic peaks was realized through using multiple iterations of the moving average of signal curves and square wave curves to determine the optimal value of the normalized peak identification parameters, combined with the absolute peak retention times and peak window. The experimental results show that this algorithm can accurately identify the peaks and is not sensitive to the noise, the chromatographic peak width or the peak shape changes. It has strong adaptability to meet the on-site requirements of online monitoring devices of dissolved gases in transformer oil.

  7. Face inversion increases attractiveness.

    Science.gov (United States)

    Leder, Helmut; Goller, Juergen; Forster, Michael; Schlageter, Lena; Paul, Matthew A

    2017-07-01

    Assessing facial attractiveness is a ubiquitous, inherent, and hard-wired phenomenon in everyday interactions. As such, it has highly adapted to the default way that faces are typically processed: viewing faces in upright orientation. By inverting faces, we can disrupt this default mode, and study how facial attractiveness is assessed. Faces, rotated at 90 (tilting to either side) and 180°, were rated on attractiveness and distinctiveness scales. For both orientations, we found that faces were rated more attractive and less distinctive than upright faces. Importantly, these effects were more pronounced for faces rated low in upright orientation, and smaller for highly attractive faces. In other words, the less attractive a face was, the more it gained in attractiveness by inversion or rotation. Based on these findings, we argue that facial attractiveness assessments might not rely on the presence of attractive facial characteristics, but on the absence of distinctive, unattractive characteristics. These unattractive characteristics are potentially weighed against an individual, attractive prototype in assessing facial attractiveness. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Inverse problem in hydrogeology

    Science.gov (United States)

    Carrera, Jesús; Alcolea, Andrés; Medina, Agustín; Hidalgo, Juan; Slooten, Luit J.

    2005-03-01

    The state of the groundwater inverse problem is synthesized. Emphasis is placed on aquifer characterization, where modelers have to deal with conceptual model uncertainty (notably spatial and temporal variability), scale dependence, many types of unknown parameters (transmissivity, recharge, boundary conditions, etc.), nonlinearity, and often low sensitivity of state variables (typically heads and concentrations) to aquifer properties. Because of these difficulties, calibration cannot be separated from the modeling process, as it is sometimes done in other fields. Instead, it should be viewed as one step in the process of understanding aquifer behavior. In fact, it is shown that actual parameter estimation methods do not differ from each other in the essence, though they may differ in the computational details. It is argued that there is ample room for improvement in groundwater inversion: development of user-friendly codes, accommodation of variability through geostatistics, incorporation of geological information and different types of data (temperature, occurrence and concentration of isotopes, age, etc.), proper accounting of uncertainty, etc. Despite this, even with existing codes, automatic calibration facilitates enormously the task of modeling. Therefore, it is contended that its use should become standard practice. L'état du problème inverse des eaux souterraines est synthétisé. L'accent est placé sur la caractérisation de l'aquifère, où les modélisateurs doivent jouer avec l'incertitude des modèles conceptuels (notamment la variabilité spatiale et temporelle), les facteurs d'échelle, plusieurs inconnues sur différents paramètres (transmissivité, recharge, conditions aux limites, etc.), la non linéarité, et souvent la sensibilité de plusieurs variables d'état (charges hydrauliques, concentrations) des propriétés de l'aquifère. A cause de ces difficultés, le calibrage ne peut êtreséparé du processus de modélisation, comme c'est le

  9. Multiples waveform inversion

    KAUST Repository

    Zhang, Dongliang

    2013-01-01

    To increase the illumination of the subsurface and to eliminate the dependency of FWI on the source wavelet, we propose multiples waveform inversion (MWI) that transforms each hydrophone into a virtual point source with a time history equal to that of the recorded data. These virtual sources are used to numerically generate downgoing wavefields that are correlated with the backprojected surface-related multiples to give the migration image. Since the recorded data are treated as the virtual sources, knowledge of the source wavelet is not required, and the subsurface illumination is greatly enhanced because the entire free surface acts as an extended source compared to the radiation pattern of a traditional point source. Numerical tests on the Marmousi2 model show that the convergence rate and the spatial resolution of MWI is, respectively, faster and more accurate then FWI. The potential pitfall with this method is that the multiples undergo more than one roundtrip to the surface, which increases attenuation and reduces spatial resolution. This can lead to less resolved tomograms compared to conventional FWI. The possible solution is to combine both FWI and MWI in inverting for the subsurface velocity distribution.

  10. An interpretation of signature inversion

    International Nuclear Information System (INIS)

    Onishi, Naoki; Tajima, Naoki

    1988-01-01

    An interpretation in terms of the cranking model is presented to explain why signature inversion occurs for positive γ of the axially asymmetric deformation parameter and emerges into specific orbitals. By introducing a continuous variable, the eigenvalue equation can be reduced to a one dimensional Schroedinger equation by means of which one can easily understand the cause of signature inversion. (author)

  11. Inverse problems for Maxwell's equations

    CERN Document Server

    Romanov, V G

    1994-01-01

    The Inverse and Ill-Posed Problems Series is a series of monographs publishing postgraduate level information on inverse and ill-posed problems for an international readership of professional scientists and researchers. The series aims to publish works which involve both theory and applications in, e.g., physics, medicine, geophysics, acoustics, electrodynamics, tomography, and ecology.

  12. Algebraic properties of generalized inverses

    CERN Document Server

    Cvetković‐Ilić, Dragana S

    2017-01-01

    This book addresses selected topics in the theory of generalized inverses. Following a discussion of the “reverse order law” problem and certain problems involving completions of operator matrices, it subsequently presents a specific approach to solving the problem of the reverse order law for {1} -generalized inverses. Particular emphasis is placed on the existence of Drazin invertible completions of an upper triangular operator matrix; on the invertibility and different types of generalized invertibility of a linear combination of operators on Hilbert spaces and Banach algebra elements; on the problem of finding representations of the Drazin inverse of a 2x2 block matrix; and on selected additive results and algebraic properties for the Drazin inverse. In addition to the clarity of its content, the book discusses the relevant open problems for each topic discussed. Comments on the latest references on generalized inverses are also included. Accordingly, the book will be useful for graduate students, Ph...

  13. Observed Seasonal Variations of the Upper Ocean Structure and Air-Sea Interactions in the Andaman Sea

    Science.gov (United States)

    Liu, Yanliang; Li, Kuiping; Ning, Chunlin; Yang, Yang; Wang, Haiyuan; Liu, Jianjun; Skhokiattiwong, Somkiat; Yu, Weidong

    2018-02-01

    The Andaman Sea (AS) is a poorly observed basin, where even the fundamental physical characteristics have not been fully documented. Here the seasonal variations of the upper ocean structure and the air-sea interactions in the central AS were studied using a moored surface buoy. The seasonal double-peak pattern of the sea surface temperature (SST) was identified with the corresponding mixed layer variations. Compared with the buoys in the Bay of Bengal (BOB), the thermal stratification in the central AS was much stronger in the winter to spring, when a shallower isothermal layer and a thinner barrier layer were sustained. The temperature inversion was strongest from June to July because of substantial surface heat loss and subsurface prewarming. The heat budget analysis of the mixed layer showed that the net surface heat fluxes dominated the seasonal SST cycle. Vertical entrainment was significant from April to July. It had a strong cooling effect from April to May and a striking warming effect from June to July. A sensitivity experiment highlighted the importance of salinity. The AS warmer surface water in the winter was associated with weak heat loss caused by weaker longwave radiation and latent heat losses. However, the AS latent heat loss was larger than the BOB in summer due to its lower relative humidity.

  14. What controls the seasonal cycle of columnar methane observed by GOSAT over different regions in India?

    Science.gov (United States)

    Chandra, Naveen; Hayashida, Sachiko; Saeki, Tazu; Patra, Prabir K.

    2017-10-01

    upper troposphere. The lower tropospheric region contributes up to 60 % in the XCH4 seasonal enhancement over the Southern Peninsula and oceanic region. These differences arise due to the complex atmospheric transport mechanisms caused by the seasonally varying monsoon. The CH4 enriched air mass is uplifted from a high-emission region of the Gangetic Plain by the SW monsoon circulation and deep cumulus convection and then confined by anticyclonic wind in the upper tropospheric heights ( ˜ 200 hPa). The anticyclonic confinement of surface emission over a wider South Asia region leads to a strong contribution of the upper troposphere in the formation of the XCH4 peak over northern India, including the semi-arid regions with extremely low CH4 emissions. Based on this analysis, we suggest that a link between surface emissions and higher levels of XCH4 is not always valid over Asian monsoon regions, although there is often a fair correlation between surface emissions and XCH4. The overall validity of ACTM simulation for capturing GOSAT observed seasonal and spatial XCH4 variability will allow us to perform inverse modeling of XCH4 emissions in the future using XCH4 data.

  15. Employer Attitudes towards Peak Hour Avoidance

    NARCIS (Netherlands)

    Vonk Noordegraaf, D.M.; Annema, J.A.

    2012-01-01

    Peak Hour Avoidance is a relatively new Dutch mobility management measure. To reduce congestion frequent car drivers are given a financial reward for reducing the proportion of trips that they make during peak hours on a specific motorway section. Although previous studies show that employers are

  16. Employer attitudes towards peak hour avoidance

    NARCIS (Netherlands)

    Noordegraaf, D.M.V.; Annema, J.A.

    2012-01-01

    Peak Hour Avoidance is a relatively new Dutch mobility management measure. To reduce congestion frequent car drivers are given a financial reward for reducing the proportion of trips that they make during peak hours on a specific motorway section. Although previous studies show that employers are

  17. Peak load pricing lowers generation costs

    International Nuclear Information System (INIS)

    Lande, R.H.

    1980-01-01

    Before a utility implements peak load pricing for different classes of consumers, the costs and the benefits should be compared. The methodology described enables a utility to determine whether peak load pricing should be introduced for specific users. Cost-benefit analyses for domestic consumers and commercial/industrial consumers, showing break-even points are presented. (author)

  18. Peak Shaving Considering Streamflow Uncertainties | Iwuagwu ...

    African Journals Online (AJOL)

    The main thrust of this paper is peak shaving with a Stochastic hydro model. In peak sharing, the amount of hydro energy scheduled may be a minimum but it serves to replace less efficient thermal units. The sample system is die Kainji hydro plant and the thermal units of the National Electric Power Authority. The random ...

  19. Methane emissions from a dairy feedlot during the fall and winter seasons in Northern China

    Energy Technology Data Exchange (ETDEWEB)

    Gao Zhiling, E-mail: zhilinggao@hebau.edu.cn [College of Resources and Environmental Sciences, Agricultural University of Hebei, Baoding 071000 (China); Yuan Huijun; Ma Wenqi [College of Resources and Environmental Sciences, Agricultural University of Hebei, Baoding 071000 (China); Liu Xuejun [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Desjardins, R.L. [Agriculture and Agri-Food Canada, Research Branch, Ottawa, K1A 0C6 (Canada)

    2011-05-15

    Accurately determining methane emission factors of dairy herd in China is imperative because of China's large population of dairy cattle. An inverse dispersion technique in conjunction with open-path lasers was used to quantify methane emissions from a dairy feedlot during the fall and winter seasons in 2009-2010. The methane emissions had a significant diurnal pattern during both periods with three emission peaks corresponding to the feeding schedule. A 10% greater emission rate in the fall season was obtained most likely by the higher methane emission from manure during that period. An annual methane emission rate of 109 {+-} 6.7 kg CH{sub 4} yr{sup -1} characterized with a methane emission intensity of 32.3 {+-} 1.59 L CH{sub 4} L{sup -1} of milk and a methane conversion factor (Y{sub m}) of 7.3 {+-} 0.38% for mature cattle was obtained, indicating the high methane emission intensity and low milk productivity in Northern China. - Highlights: > CH{sub 4} emission from the feedlot in China was associated with clear diurnal pattern. > Methane conversion factor for mature cows in this feedlot was about 7.3%. > This feedlot was characterized with relatively high methane emission intensity. - High methane emission intensity and low milk productivity of Chinese dairy production are indicated.

  20. The peak in neutron powder diffraction

    International Nuclear Information System (INIS)

    Laar, B. van; Yelon, W.B.

    1984-01-01

    For the application of Rietveld profile analysis to neutron powder diffraction data a precise knowledge of the peak profile, in both shape and position, is required. The method now in use employs a Gaussian shaped profile with a semi-empirical asymmetry correction for low-angle peaks. The integrated intensity is taken to be proportional to the classical Lorentz factor calculated for the X-ray case. In this paper an exact expression is given for the peak profile based upon the geometrical dimensions of the diffractometer. It is shown that the asymmetry of observed peaks is well reproduced by this expression. The angular displacement of the experimental profile with respect to the nominal Bragg angle value is larger than expected. Values for the correction to the classical Lorentz factor for the integrated intensity are given. The exact peak profile expression has been incorporated into a Rietveld profile analysis refinement program. (Auth.)

  1. Peak tree: a new tool for multiscale hierarchical representation and peak detection of mass spectrometry data.

    Science.gov (United States)

    Zhang, Peng; Li, Houqiang; Wang, Honghui; Wong, Stephen T C; Zhou, Xiaobo

    2011-01-01

    Peak detection is one of the most important steps in mass spectrometry (MS) analysis. However, the detection result is greatly affected by severe spectrum variations. Unfortunately, most current peak detection methods are neither flexible enough to revise false detection results nor robust enough to resist spectrum variations. To improve flexibility, we introduce peak tree to represent the peak information in MS spectra. Each tree node is a peak judgment on a range of scales, and each tree decomposition, as a set of nodes, is a candidate peak detection result. To improve robustness, we combine peak detection and common peak alignment into a closed-loop framework, which finds the optimal decomposition via both peak intensity and common peak information. The common peak information is derived and loopily refined from the density clustering of the latest peak detection result. Finally, we present an improved ant colony optimization biomarker selection method to build a whole MS analysis system. Experiment shows that our peak detection method can better resist spectrum variations and provide higher sensitivity and lower false detection rates than conventional methods. The benefits from our peak-tree-based system for MS disease analysis are also proved on real SELDI data.

  2. Multiscale peak detection in wavelet space.

    Science.gov (United States)

    Zhang, Zhi-Min; Tong, Xia; Peng, Ying; Ma, Pan; Zhang, Ming-Jin; Lu, Hong-Mei; Chen, Xiao-Qing; Liang, Yi-Zeng

    2015-12-07

    Accurate peak detection is essential for analyzing high-throughput datasets generated by analytical instruments. Derivatives with noise reduction and matched filtration are frequently used, but they are sensitive to baseline variations, random noise and deviations in the peak shape. A continuous wavelet transform (CWT)-based method is more practical and popular in this situation, which can increase the accuracy and reliability by identifying peaks across scales in wavelet space and implicitly removing noise as well as the baseline. However, its computational load is relatively high and the estimated features of peaks may not be accurate in the case of peaks that are overlapping, dense or weak. In this study, we present multi-scale peak detection (MSPD) by taking full advantage of additional information in wavelet space including ridges, valleys, and zero-crossings. It can achieve a high accuracy by thresholding each detected peak with the maximum of its ridge. It has been comprehensively evaluated with MALDI-TOF spectra in proteomics, the CAMDA 2006 SELDI dataset as well as the Romanian database of Raman spectra, which is particularly suitable for detecting peaks in high-throughput analytical signals. Receiver operating characteristic (ROC) curves show that MSPD can detect more true peaks while keeping the false discovery rate lower than MassSpecWavelet and MALDIquant methods. Superior results in Raman spectra suggest that MSPD seems to be a more universal method for peak detection. MSPD has been designed and implemented efficiently in Python and Cython. It is available as an open source package at .

  3. Timing of Seasonal Sales.

    OpenAIRE

    Courty, Pascal; Li, Hao

    1999-01-01

    We present a model of timing of seasonal sales where stores choose several designs at the beginning of the season without knowing wich one, if any, will be fashionable. Fashionable designs have a chance to fetch high prices in fashion markets while non-fashionable ones must be sold in a discount market. In the beginning of the season, stores charge high prices in the hope of capturing their fashion market. As the end of the season approaches with goods still on the shelves, stores adjust down...

  4. Indium oxide inverse opal films synthesized by structure replication method

    Science.gov (United States)

    Amrehn, Sabrina; Berghoff, Daniel; Nikitin, Andreas; Reichelt, Matthias; Wu, Xia; Meier, Torsten; Wagner, Thorsten

    2016-04-01

    We present the synthesis of indium oxide (In2O3) inverse opal films with photonic stop bands in the visible range by a structure replication method. Artificial opal films made of poly(methyl methacrylate) (PMMA) spheres are utilized as template. The opal films are deposited via sedimentation facilitated by ultrasonication, and then impregnated by indium nitrate solution, which is thermally converted to In2O3 after drying. The quality of the resulting inverse opal film depends on many parameters; in this study the water content of the indium nitrate/PMMA composite after drying is investigated. Comparison of the reflectance spectra recorded by vis-spectroscopy with simulated data shows a good agreement between the peak position and calculated stop band positions for the inverse opals. This synthesis is less complex and highly efficient compared to most other techniques and is suitable for use in many applications.

  5. Numerical modeling of Harmonic Imaging and Pulse Inversion fields

    Science.gov (United States)

    Humphrey, Victor F.; Duncan, Tracy M.; Duck, Francis

    2003-10-01

    Tissue Harmonic Imaging (THI) and Pulse Inversion (PI) Harmonic Imaging exploit the harmonics generated as a result of nonlinear propagation through tissue to improve the performance of imaging systems. A 3D finite difference model, that solves the KZK equation in the frequency domain, is used to investigate the finite amplitude fields produced by rectangular transducers driven with short pulses and their inverses, in water and homogeneous tissue. This enables the characteristic of the fields and the effective PI field to be calculated. The suppression of the fundamental field in PI is monitored, and the suppression of side lobes and a reduction in the effective beamwidth for each field are calculated. In addition, the differences between the pulse and inverse pulse spectra resulting from the use of very short pulses are noted, and the differences in the location of the fundamental and second harmonic spectral peaks observed.

  6. A Generalization of the Spherical Inversion

    Science.gov (United States)

    Ramírez, José L.; Rubiano, Gustavo N.

    2017-01-01

    In the present article, we introduce a generalization of the spherical inversion. In particular, we define an inversion with respect to an ellipsoid, and prove several properties of this new transformation. The inversion in an ellipsoid is the generalization of the elliptic inversion to the three-dimensional space. We also study the inverse images…

  7. Nine years of global hydrocarbon emissions based on source inversion of OMI formaldehyde observations

    Directory of Open Access Journals (Sweden)

    M. Bauwens

    2016-08-01

    Full Text Available As formaldehyde (HCHO is a high-yield product in the oxidation of most volatile organic compounds (VOCs emitted by fires, vegetation, and anthropogenic activities, satellite observations of HCHO are well-suited to inform us on the spatial and temporal variability of the underlying VOC sources. The long record of space-based HCHO column observations from the Ozone Monitoring Instrument (OMI is used to infer emission flux estimates from pyrogenic and biogenic volatile organic compounds (VOCs on the global scale over 2005–2013. This is realized through the method of source inverse modeling, which consists in the optimization of emissions in a chemistry-transport model (CTM in order to minimize the discrepancy between the observed and modeled HCHO columns. The top–down fluxes are derived in the global CTM IMAGESv2 by an iterative minimization algorithm based on the full adjoint of IMAGESv2, starting from a priori emission estimates provided by the newly released GFED4s (Global Fire Emission Database, version 4s inventory for fires, and by the MEGAN-MOHYCAN inventory for isoprene emissions. The top–down fluxes are compared to two independent inventories for fire (GFAS and FINNv1.5 and isoprene emissions (MEGAN-MACC and GUESS-ES. The inversion indicates a moderate decrease (ca. 20 % in the average annual global fire and isoprene emissions, from 2028 Tg C in the a priori to 1653 Tg C for burned biomass, and from 343 to 272 Tg for isoprene fluxes. Those estimates are acknowledged to depend on the accuracy of formaldehyde data, as well as on the assumed fire emission factors and the oxidation mechanisms leading to HCHO production. Strongly decreased top–down fire fluxes (30–50 % are inferred in the peak fire season in Africa and during years with strong a priori fluxes associated with forest fires in Amazonia (in 2005, 2007, and 2010, bushfires in Australia (in 2006 and 2011, and peat burning in Indonesia (in 2006 and 2009, whereas

  8. Trends in land surface phenology and atmospheric CO2 seasonality in the Northern Hemisphere terrestrial ecosystems

    Science.gov (United States)

    Gonsamo, A.; Chen, J. M.

    2017-12-01

    Northern terrestrial ecosystems have shown global warming-induced advances in start, delays in end, and thus increased lengths of growing season and gross photosynthesis in recent decades. The tradeoffs between seasonal dynamics of two opposing fluxes, CO2 uptake through photosynthesis and release through respiration, determine the influence of the terrestrial ecosystems on the atmospheric CO2 concentration and 13C/12C isotope ratio seasonality. Atmospheric CO2 and 13C/12C seasonality is controlled by vegetation phenology, but is not identical because growth will typically commence some time before and terminate some time after the net carbon exchange changes sign in spring and autumn, respectively. Here, we use 34-year satellite normalized difference vegetation index (NDVI) observations to determine how changes in vegetation productivity and phenology affect both the atmospheric CO2 and 13C/12C seasonality. Differences and similarities in recent trends of CO2 and 13C/12C seasonality and vegetation phenology will be discussed. Furthermore, we use the NDVI observations, and atmospheric CO2 and 13C/12C data to show the trends and variability of the timing of peak season plant activity. Preliminary results show that the peak season plant activity of the Northern Hemisphere extra-tropical terrestrial ecosystems is shifting towards spring, largely in response to the warming-induced advance of the start of growing season. Besides, the spring-ward shift of the peak plant activity is contributing the most to the increasing peak season productivity. In other words, earlier start of growing season is highly linked to earlier arrival of peak of season and higher NDVI. Changes in the timing of peak season plant activity are expected to disrupt the synchrony of biotic interaction and exert strong biophysical feedbacks on climate by modifying the surface albedo and energy budget.

  9. Red photoluminescent property and modification of WO3:Eu3+ inverse opal for blue light converted LEDs

    Science.gov (United States)

    Ruan, Jiufeng; Yang, Zhengwen; Huang, Anjun; Chai, Zhuangzhuang; Qiu, Jianbei; Song, Zhiguo

    2018-01-01

    Blue light converted light-emitting diodes is of great significance as a candidate for next generation lighting. In this work, the WO3:Eu3+ inverse opal photonic crystals were prepared and their luminescence properties were studied. The results demonstrated that the main excitation peak of WO3:Eu3+ inverse opals were located at 465 nm. The red luminescence peak at the 613 nm was observed in the WO3:Eu3+ inverse opal upon 465 nm excitation, exhibiting better red color purity. The influence of photonic band gap on the photoluminescence of WO3:Eu3+ inverse opal was obtained. When the red luminescence peak is in the regions of the photonic band gap and the edge of the band-gap, the red luminescence suppression and enhancement was observed respectively. The WO3:Eu3+ inverse opals may be a promising candidate for the blue light converted LEDs.

  10. Spectral solution of the inverse Mie problem

    Science.gov (United States)

    Romanov, Andrey V.; Konokhova, Anastasiya I.; Yastrebova, Ekaterina S.; Gilev, Konstantin V.; Strokotov, Dmitry I.; Chernyshev, Andrei V.; Maltsev, Valeri P.; Yurkin, Maxim A.

    2017-10-01

    We developed a fast method to determine size and refractive index of homogeneous spheres from the power Fourier spectrum of their light-scattering patterns (LSPs), measured with the scanning flow cytometer. Specifically, we used two spectral parameters: the location of the non-zero peak and zero-frequency amplitude, and numerically inverted the map from the space of particle characteristics (size and refractive index) to the space of spectral parameters. The latter parameters can be reliably resolved only for particle size parameter greater than 11, and the inversion is unique only in the limited range of refractive index with upper limit between 1.1 and 1.25 (relative to the medium) depending on the size parameter and particular definition of uniqueness. The developed method was tested on two experimental samples, milk fat globules and spherized red blood cells, and resulted in accuracy not worse than the reference method based on the least-square fit of the LSP with the Mie theory. Moreover, for particles with significant deviation from the spherical shape the spectral method was much closer to the Mie-fit result than the estimated uncertainty of the latter. The spectral method also showed adequate results for synthetic LSPs of spheroids with aspect ratios up to 1.4. Overall, we present a general framework, which can be used to construct an inverse algorithm for any other experimental signals.

  11. Isotope resolution of the iron peak

    International Nuclear Information System (INIS)

    Henke, R.P.; Benton, E.V.

    1977-01-01

    A stack of Lexan detectors from the Apollo 17 mission has been analyzed to obtain Z measurements of sufficient accuracy to resolve the iron peak into its isotopic components. Within this distribution several peaks are present. With the centrally located, most populated peak assumed to be 56 Fe, the measurements imply that the abundances of 54 Fe and 58 Fe are appreciable fractions of the 56 Fe abundance. This result is in agreement with those of Webber et al. and Siegman et al. but in disagreement with the predictions of Tsao et al. (Auth.)

  12. Peak load arrangements : Assessment of Nordel guidelines

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    Two Nordic countries, Sweden and Finland, have legislation that empowers the TSO to acquire designated peak load resources to mitigate the risk for shortage situations during the winter. In Denmark, the system operator procures resources to maintain a satisfactory level of security of supply. In Norway the TSO has set up a Regulation Power Option Market (RKOM) to secure a satisfactory level of operational reserves at all times, also in winter with high load demand. Only the arrangements in Finland and Sweden fall under the heading of Peak Load Arrangements defined in Nordel Guidelines. NordREG has been invited by the Electricity Market Group (EMG) to evaluate Nordel's proposal for 'Guidelines for transitional Peak Load Arrangements'. The EMG has also financed a study made by EC Group to support NordREG in the evaluation of the proposal. The study has been taken into account in NordREG's evaluation. In parallel to the EMG task, the Swedish regulator, the Energy Markets Inspectorate, has been given the task by the Swedish government to investigate a long term solution of the peak load issue. The Swedish and Finnish TSOs have together with Nord Pool Spot worked on finding a harmonized solution for activation of the peak load reserves in the market. An agreement accepted by the relevant authorities was reached in early January 2009, and the arrangement has been implemented since 19th January 2009. NordREG views that the proposed Nordel guidelines have served as a starting point for the presently agreed procedure. However, NordREG does not see any need to further develop the Nordel guidelines for peak load arrangements. NordREG agrees with Nordel that the market should be designed to solve peak load problems through proper incentives to market players. NordREG presumes that the relevant authorities in each country will take decisions on the need for any peak load arrangement to ensure security of supply. NordREG proposes that such decisions should be

  13. Automated Peak Picking and Peak Integration in Macromolecular NMR Spectra Using AUTOPSY

    Science.gov (United States)

    Koradi, Reto; Billeter, Martin; Engeli, Max; Güntert, Peter; Wüthrich, Kurt

    1998-12-01

    A new approach for automated peak picking of multidimensional protein NMR spectra with strong overlap is introduced, which makes use of the program AUTOPSY (automatedpeak picking for NMRspectroscopy). The main elements of this program are a novel function for local noise level calculation, the use of symmetry considerations, and the use of lineshapes extracted from well-separated peaks for resolving groups of strongly overlapping peaks. The algorithm generates peak lists with precise chemical shift and integral intensities, and a reliability measure for the recognition of each peak. The results of automated peak picking of NOESY spectra with AUTOPSY were tested in combination with the combined automated NOESY cross peak assignment and structure calculation routine NOAH implemented in the program DYANA. The quality of the resulting structures was found to be comparable with those from corresponding data obtained with manual peak picking.

  14. Objective mapping of temperature field by stochastic inverse method using acoustic tomography experimental data of eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, T.V.R.; Rao, M.M.M.; Sadhuram, Y.

    . The data are revisited for objective mapping of the temperature fields using Stochastic Inverse Method. Hourly reciprocal transmissions were carried with time lag of 30 minutes between each direction. From the multipath arrival patterns, significant peaks...

  15. Modelling of peak temperature during friction stir processing of magnesium alloy AZ91

    Science.gov (United States)

    Vaira Vignesh, R.; Padmanaban, R.

    2018-02-01

    Friction stir processing (FSP) is a solid state processing technique with potential to modify the properties of the material through microstructural modification. The study of heat transfer in FSP aids in the identification of defects like flash, inadequate heat input, poor material flow and mixing etc. In this paper, transient temperature distribution during FSP of magnesium alloy AZ91 was simulated using finite element modelling. The numerical model results were validated using the experimental results from the published literature. The model was used to predict the peak temperature obtained during FSP for various process parameter combinations. The simulated peak temperature results were used to develop a statistical model. The effect of process parameters namely tool rotation speed, tool traverse speed and shoulder diameter of the tool on the peak temperature was investigated using the developed statistical model. It was found that peak temperature was directly proportional to tool rotation speed and shoulder diameter and inversely proportional to tool traverse speed.

  16. Statistical perspectives on inverse problems

    DEFF Research Database (Denmark)

    Andersen, Kim Emil

    of the interior of an object from electrical boundary measurements. One part of this thesis concerns statistical approaches for solving, possibly non-linear, inverse problems. Thus inverse problems are recasted in a form suitable for statistical inference. In particular, a Bayesian approach for regularisation...... problem is given in terms of probability distributions. Posterior inference is obtained by Markov chain Monte Carlo methods and new, powerful simulation techniques based on e.g. coupled Markov chains and simulated tempering is developed to improve the computational efficiency of the overall simulation......Inverse problems arise in many scientific disciplines and pertain to situations where inference is to be made about a particular phenomenon from indirect measurements. A typical example, arising in diffusion tomography, is the inverse boundary value problem for non-invasive reconstruction...

  17. Size Estimates in Inverse Problems

    KAUST Repository

    Di Cristo, Michele

    2014-01-01

    Detection of inclusions or obstacles inside a body by boundary measurements is an inverse problems very useful in practical applications. When only finite numbers of measurements are available, we try to detect some information on the embedded

  18. Wave-equation dispersion inversion

    KAUST Repository

    Li, Jing; Feng, Zongcai; Schuster, Gerard T.

    2016-01-01

    We present the theory for wave-equation inversion of dispersion curves, where the misfit function is the sum of the squared differences between the wavenumbers along the predicted and observed dispersion curves. The dispersion curves are obtained

  19. Testing earthquake source inversion methodologies

    KAUST Repository

    Page, Morgan T.

    2011-01-01

    Source Inversion Validation Workshop; Palm Springs, California, 11-12 September 2010; Nowadays earthquake source inversions are routinely performed after large earthquakes and represent a key connection between recorded seismic and geodetic data and the complex rupture process at depth. The resulting earthquake source models quantify the spatiotemporal evolution of ruptures. They are also used to provide a rapid assessment of the severity of an earthquake and to estimate losses. However, because of uncertainties in the data, assumed fault geometry and velocity structure, and chosen rupture parameterization, it is not clear which features of these source models are robust. Improved understanding of the uncertainty and reliability of earthquake source inversions will allow the scientific community to use the robust features of kinematic inversions to more thoroughly investigate the complexity of the rupture process and to better constrain other earthquakerelated computations, such as ground motion simulations and static stress change calculations.

  20. Parameter estimation and inverse problems

    CERN Document Server

    Aster, Richard C; Thurber, Clifford H

    2005-01-01

    Parameter Estimation and Inverse Problems primarily serves as a textbook for advanced undergraduate and introductory graduate courses. Class notes have been developed and reside on the World Wide Web for faciliting use and feedback by teaching colleagues. The authors'' treatment promotes an understanding of fundamental and practical issus associated with parameter fitting and inverse problems including basic theory of inverse problems, statistical issues, computational issues, and an understanding of how to analyze the success and limitations of solutions to these probles. The text is also a practical resource for general students and professional researchers, where techniques and concepts can be readily picked up on a chapter-by-chapter basis.Parameter Estimation and Inverse Problems is structured around a course at New Mexico Tech and is designed to be accessible to typical graduate students in the physical sciences who may not have an extensive mathematical background. It is accompanied by a Web site that...

  1. Inversion Therapy: Can It Relieve Back Pain?

    Science.gov (United States)

    Inversion therapy: Can it relieve back pain? Does inversion therapy relieve back pain? Is it safe? Answers from Edward R. Laskowski, M.D. Inversion therapy doesn't provide lasting relief from back ...

  2. Bayesian Peak Picking for NMR Spectra

    KAUST Repository

    Cheng, Yichen

    2014-02-01

    Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  3. Peak-Seeking Control for Trim Optimization

    Data.gov (United States)

    National Aeronautics and Space Administration — Innovators have developed a peak-seeking algorithm that can reduce drag and improve performance and fuel efficiency by optimizing aircraft trim in real time. The...

  4. Circadian activity of Lutzomyia shannoni (Diptera: Psychodidae) during late season population peaks.

    Science.gov (United States)

    Minter, Logan M; Brown, Grayson C

    2010-12-01

    The phlebotomine sand fly, Lutzomyia shannoni (Dyar), is considered both zoophillic and anthropophillic and may be a potential vector of human and livestock pathogens. While the known range of this species in North America has recently been expanded, many aspects of its natural history, which are fundamental components for assessments of disease risk or development of integrated pest management programs for the vector, remain unclear. One is the time of day when individuals are active and searching for blood meals. Through the use of a rotating trap mechanism, male L. shannoni were found to be active earlier in the evening (1-4 h after sunset), whereas the majority of female activity occurred after midnight.

  5. Thermal measurements and inverse techniques

    CERN Document Server

    Orlande, Helcio RB; Maillet, Denis; Cotta, Renato M

    2011-01-01

    With its uncommon presentation of instructional material regarding mathematical modeling, measurements, and solution of inverse problems, Thermal Measurements and Inverse Techniques is a one-stop reference for those dealing with various aspects of heat transfer. Progress in mathematical modeling of complex industrial and environmental systems has enabled numerical simulations of most physical phenomena. In addition, recent advances in thermal instrumentation and heat transfer modeling have improved experimental procedures and indirect measurements for heat transfer research of both natural phe

  6. Computation of inverse magnetic cascades

    International Nuclear Information System (INIS)

    Montgomery, D.

    1981-10-01

    Inverse cascades of magnetic quantities for turbulent incompressible magnetohydrodynamics are reviewed, for two and three dimensions. The theory is extended to the Strauss equations, a description intermediate between two and three dimensions appropriate to tokamak magnetofluids. Consideration of the absolute equilibrium Gibbs ensemble for the system leads to a prediction of an inverse cascade of magnetic helicity, which may manifest itself as a major disruption. An agenda for computational investigation of this conjecture is proposed

  7. Genomic Evidence for Adaptive Inversion Clines in Drosophila melanogaster.

    Science.gov (United States)

    Kapun, Martin; Fabian, Daniel K; Goudet, Jérôme; Flatt, Thomas

    2016-05-01

    Clines in chromosomal inversion polymorphisms-presumably driven by climatic gradients-are common but there is surprisingly little evidence for selection acting on them. Here we address this long-standing issue in Drosophila melanogaster by using diagnostic single nucleotide polymorphism (SNP) markers to estimate inversion frequencies from 28 whole-genome Pool-seq samples collected from 10 populations along the North American east coast. Inversions In(3L)P, In(3R)Mo, and In(3R)Payne showed clear latitudinal clines, and for In(2L)t, In(2R)NS, and In(3R)Payne the steepness of the clinal slopes changed between summer and fall. Consistent with an effect of seasonality on inversion frequencies, we detected small but stable seasonal fluctuations of In(2R)NS and In(3R)Payne in a temperate Pennsylvanian population over 4 years. In support of spatially varying selection, we observed that the cline in In(3R)Payne has remained stable for >40 years and that the frequencies of In(2L)t and In(3R)Payne are strongly correlated with climatic factors that vary latitudinally, independent of population structure. To test whether these patterns are adaptive, we compared the amount of genetic differentiation of inversions versus neutral SNPs and found that the clines in In(2L)t and In(3R)Payne are maintained nonneutrally and independent of admixture. We also identified numerous clinal inversion-associated SNPs, many of which exhibit parallel differentiation along the Australian cline and reside in genes known to affect fitness-related traits. Together, our results provide strong evidence that inversion clines are maintained by spatially-and perhaps also temporally-varying selection. We interpret our data in light of current hypotheses about how inversions are established and maintained. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. EDITORIAL: Inverse Problems in Engineering

    Science.gov (United States)

    West, Robert M.; Lesnic, Daniel

    2007-01-01

    Presented here are 11 noteworthy papers selected from the Fifth International Conference on Inverse Problems in Engineering: Theory and Practice held in Cambridge, UK during 11-15 July 2005. The papers have been peer-reviewed to the usual high standards of this journal and the contributions of reviewers are much appreciated. The conference featured a good balance of the fundamental mathematical concepts of inverse problems with a diverse range of important and interesting applications, which are represented here by the selected papers. Aspects of finite-element modelling and the performance of inverse algorithms are investigated by Autrique et al and Leduc et al. Statistical aspects are considered by Emery et al and Watzenig et al with regard to Bayesian parameter estimation and inversion using particle filters. Electrostatic applications are demonstrated by van Berkel and Lionheart and also Nakatani et al. Contributions to the applications of electrical techniques and specifically electrical tomographies are provided by Wakatsuki and Kagawa, Kim et al and Kortschak et al. Aspects of inversion in optical tomography are investigated by Wright et al and Douiri et al. The authors are representative of the worldwide interest in inverse problems relating to engineering applications and their efforts in producing these excellent papers will be appreciated by many readers of this journal.

  9. Instream flow needs below peaking hydroelectric projects

    International Nuclear Information System (INIS)

    Milhous, R.T.

    1991-01-01

    This paper reports on a method developed to assist in the determination of instream flow needs below hydroelectric projects operated in a peaking mode. Peaking hydroelectric projects significantly change streamflow over a short period of time; consequently, any instream flow methodology must consider the dual flows associated with peaking projects. The dual flows are the lowest flow and the maximum generation flow of a peaking cycle. The methodology is based on elements of the Physical Habitat Simulation System of the U.S. Fish and Wildlife Service and uses habitat, rather than fish numbers or biomas, as at basic response variable. All aquatic animals are subject to the rapid changes in streamflow which cause rapid swings in habitat quality. Some aquatic organisms are relatively fixed in location in the stream while others can move when flows change. The habitat available from a project operated in peaking mode is considered to be the minimum habitat occurring during a cycle of habitat change. The methodology takes in to consideration that some aquatic animals can move and others cannot move during a peaking cycle

  10. Seasonal prolactin secretion and its role in seasonal reproduction: a review.

    Science.gov (United States)

    Curlewis, J D

    1992-01-01

    The majority of seasonally breeding mammals show a seasonal pattern of prolactin secretion with peak concentrations in spring or summer and a nadir in autumn or winter. Photoperiod influences prolactin secretion via its effects on the secretion of the pineal hormone melatonin. Preliminary evidence suggests that the effects of melatonin on both prolactin and gonadotrophin secretion are via a common target area, possibly within the anterior hypothalamus, and that differences in response to photoperiod may be due to differences in the processing and/or interpretation of the melatonin signal. In contrast to seasonal gonadotrophin secretion, the seasonal changes in prolactin are not due to changes in the sensitivity of a feedback loop and so must be due to direct effects on the hypothalamic pathways that control prolactin secretion. Little else can be said with confidence about the neuroendocrine mechanisms that lead to the seasonal changes in prolactin secretion. Dopamine and noradrenaline turnover in the arcuate nucleus and median eminence decrease under short daylength. If catecholamine turnover in these structures is positively correlated with catecholamine concentrations in the long or short hypophysial portal vessels, it is unlikely that the decrease in prolactin concentration in winter is due to the effects of increased concentrations of dopamine or noradrenaline in the portal vessels. There is, however, evidence for increased pituitary sensitivity to dopamine under short daylength, so increased dopamine concentrations may not be required for suppression of prolactin secretion at this time. In addition to the diminished secretion of prolactin under short daylength, rate of prolactin synthesis and pituitary content of prolactin also decline although the mechanisms that regulate these changes are poorly understood. Although all seasonal breeders show a seasonal change in prolactin secretion, there are continuously breeding species in which prolactin secretion is

  11. Relationships among peak power output, peak bar velocity, and mechanomyographic amplitude during the free-weight bench press exercise.

    Science.gov (United States)

    Stock, Matt S; Beck, Travis W; Defreitas, Jason M; Dillon, Michael A

    2010-10-01

    The purpose of this study was to examine the relationships among mechanomyographic (MMG) amplitude, power output, and bar velocity during the free-weight bench press exercise. Twenty-one resistance-trained men [one-repetition maximum (1-RM) bench press = 125.4+18.4 kg] performed bench press muscle actions as explosively as possible from 10% to 90% of the 1-RM while peak power output and peak bar velocity were assessed with a TENDO Weightlifting Analyzer. During each muscle action, surface MMG signals were detected from the right and left pectoralis major and triceps brachii, and the concentric portion of the range of motion was selected for analysis. Results indicated that power output increased from 10% to 50% 1-RM, followed by decreases from 50% to 90% 1-RM, but MMG amplitude for each of the muscles increased from 10 to 80% 1-RM. The results of this study indicate that during the free-weight bench press exercise, MMG amplitude was not related to power output, but was inversely related to bar velocity and directly related to the external load being lifted. In future research, coaches and sport scientists may be able to estimate force/torque production from individual muscles during multi-joint, dynamic constant external resistance muscle actions.

  12. Inverse modeling and mapping US air quality influences of inorganic PM2.5 precursor emissions using the adjoint of GEOS-Chem

    Science.gov (United States)

    Henze, D. K.; Seinfeld, J. H.; Shindell, D. T.

    2009-08-01

    Influences of specific sources of inorganic PM2.5 on peak and ambient aerosol concentrations in the US are evaluated using a combination of inverse modeling and sensitivity analysis. First, sulfate and nitrate aerosol measurements from the IMPROVE network are assimilated using the four-dimensional variational (4D-Var) method into the GEOS-Chem chemical transport model in order to constrain emissions estimates in four separate month-long inversions (one per season). Of the precursor emissions, these observations primarily constrain ammonia (NH3). While the net result is a decrease in estimated US~NH3 emissions relative to the original inventory, there is considerable variability in adjustments made to NH3 emissions in different locations, seasons and source sectors, such as focused decreases in the midwest during July, broad decreases throughout the US~in January, increases in eastern coastal areas in April, and an effective redistribution of emissions from natural to anthropogenic sources. Implementing these constrained emissions, the adjoint model is applied to quantify the influences of emissions on representative PM2.5 air quality metrics within the US. The resulting sensitivity maps display a wide range of spatial, sectoral and seasonal variability in the susceptibility of the air quality metrics to absolute emissions changes and the effectiveness of incremental emissions controls of specific source sectors. NH3 emissions near sources of sulfur oxides (SOx) are estimated to most influence peak inorganic PM2.5 levels in the East; thus, the most effective controls of NH3 emissions are often disjoint from locations of peak NH3 emissions. Controls of emissions from industrial sectors of SOx and NOx are estimated to be more effective than surface emissions, and changes to NH3 emissions in regions dominated by natural sources are disproportionately more effective than regions dominated by anthropogenic sources. NOx controls are most effective in northern states in

  13. Inverse modelling of European CH4 emissions during 2006-2012 using different inverse models and reassessed atmospheric observations

    Science.gov (United States)

    Bergamaschi, Peter; Karstens, Ute; Manning, Alistair J.; Saunois, Marielle; Tsuruta, Aki; Berchet, Antoine; Vermeulen, Alexander T.; Arnold, Tim; Janssens-Maenhout, Greet; Hammer, Samuel; Levin, Ingeborg; Schmidt, Martina; Ramonet, Michel; Lopez, Morgan; Lavric, Jost; Aalto, Tuula; Chen, Huilin; Feist, Dietrich G.; Gerbig, Christoph; Haszpra, László; Hermansen, Ove; Manca, Giovanni; Moncrieff, John; Meinhardt, Frank; Necki, Jaroslaw; Galkowski, Michal; O'Doherty, Simon; Paramonova, Nina; Scheeren, Hubertus A.; Steinbacher, Martin; Dlugokencky, Ed

    2018-01-01

    We present inverse modelling (top down) estimates of European methane (CH4) emissions for 2006-2012 based on a new quality-controlled and harmonised in situ data set from 18 European atmospheric monitoring stations. We applied an ensemble of seven inverse models and performed four inversion experiments, investigating the impact of different sets of stations and the use of a priori information on emissions. The inverse models infer total CH4 emissions of 26.8 (20.2-29.7) Tg CH4 yr-1 (mean, 10th and 90th percentiles from all inversions) for the EU-28 for 2006-2012 from the four inversion experiments. For comparison, total anthropogenic CH4 emissions reported to UNFCCC (bottom up, based on statistical data and emissions factors) amount to only 21.3 Tg CH4 yr-1 (2006) to 18.8 Tg CH4 yr-1 (2012). A potential explanation for the higher range of top-down estimates compared to bottom-up inventories could be the contribution from natural sources, such as peatlands, wetlands, and wet soils. Based on seven different wetland inventories from the Wetland and Wetland CH4 Inter-comparison of Models Project (WETCHIMP), total wetland emissions of 4.3 (2.3-8.2) Tg CH4 yr-1 from the EU-28 are estimated. The hypothesis of significant natural emissions is supported by the finding that several inverse models yield significant seasonal cycles of derived CH4 emissions with maxima in summer, while anthropogenic CH4 emissions are assumed to have much lower seasonal variability. Taking into account the wetland emissions from the WETCHIMP ensemble, the top-down estimates are broadly consistent with the sum of anthropogenic and natural bottom-up inventories. However, the contribution of natural sources and their regional distribution remain rather uncertain. Furthermore, we investigate potential biases in the inverse models by comparison with regular aircraft profiles at four European sites and with vertical profiles obtained during the Infrastructure for Measurement of the European Carbon

  14. Limitation of peak fitting and peak shape methods for determination of activation energy of thermoluminescence glow peaks

    CERN Document Server

    Sunta, C M; Piters, T M; Watanabe, S

    1999-01-01

    This paper shows the limitation of general order peak fitting and peak shape methods for determining the activation energy of the thermoluminescence glow peaks in the cases in which retrapping probability is much higher than the recombination probability and the traps are filled up to near saturation level. Right values can be obtained when the trap occupancy is reduced by using small doses or by post-irradiation partial bleaching. This limitation in the application of these methods has not been indicated earlier. In view of the unknown nature of kinetics in the experimental samples, it is recommended that these methods of activation energy determination should be applied only at doses well below the saturation dose.

  15. Seasonality in the Austrian Economy: Common Seasonals and Forecasting

    OpenAIRE

    Kunst, Robert M.

    1992-01-01

    Abstract: Seasonal cointegration generalizes the idea of cointegration to processes with unit roots at frequencies different from 0. Here, also the dual notion of common trends, "common seasonals", is adopted for the seasonal case. Using a five-variable macroeconomic core system of the Austrian economy, it is demonstrated how common seasonals and seasonal cointegrating vectors look in practice. Statistical tests provide clear evidence on seasonal cointegration in the system. However, it is sh...

  16. Statistics of peaks of Gaussian random fields

    International Nuclear Information System (INIS)

    Bardeen, J.M.; Bond, J.R.; Kaiser, N.; Szalay, A.S.; Stanford Univ., CA; California Univ., Berkeley; Cambridge Univ., England; Fermi National Accelerator Lab., Batavia, IL)

    1986-01-01

    A set of new mathematical results on the theory of Gaussian random fields is presented, and the application of such calculations in cosmology to treat questions of structure formation from small-amplitude initial density fluctuations is addressed. The point process equation is discussed, giving the general formula for the average number density of peaks. The problem of the proper conditional probability constraints appropriate to maxima are examined using a one-dimensional illustration. The average density of maxima of a general three-dimensional Gaussian field is calculated as a function of heights of the maxima, and the average density of upcrossing points on density contour surfaces is computed. The number density of peaks subject to the constraint that the large-scale density field be fixed is determined and used to discuss the segregation of high peaks from the underlying mass distribution. The machinery to calculate n-point peak-peak correlation functions is determined, as are the shapes of the profiles about maxima. 67 references

  17. Peak Oil, threat or energy worlds' phantasm?

    International Nuclear Information System (INIS)

    Favennec, Jean-Pierre

    2011-01-01

    The concept of Peak Oil is based on the work of King Hubbert, a petroleum geologist who worked for Shell in the USA in the 1960's. Based on the fact that discoveries in America reached a maximum in the 1930's, he announced that American production would reach a maximum in 1969, which did actually occur. Geologists members of the Association for the Study of Peak Oil have extrapolated this result to a worldwide scale and, since oil discoveries reached a peak in the 1960's, argued that production will peak in the very near future. It is clear that hydrocarbon reserves are finite and therefore exhaustible. But little is known regarding the level of ultimate (i.e. total existing) reserves. There are probably very large reserves of non conventional oil in addition to the reserves of conventional oil. An increasing number of specialists put maximum production at less than 100 Mb/d more for geopolitical than physical reasons. Attainable peak production will probably vary from year to year and will depend on how crude oil prices develop

  18. Electric peak power forecasting by year 2025

    International Nuclear Information System (INIS)

    Alsayegh, O.A.; Al-Matar, O.A.; Fairouz, F.A.; Al-Mulla Ali, A.

    2005-01-01

    Peak power demand in Kuwait up to the year 2025 was predicted using an artificial neural network (ANN) model. The aim of the study was to investigate the effect of air conditioning (A/C) units on long-term power demand. Five socio-economic factors were selected as inputs for the simulation: (1) gross national product, (2) population, (3) number of buildings, (4) imports of A/C units, and (5) index of industrial production. The study used socio-economic data from 1978 to 2000. Historical data of the first 10 years of the studied time period were used to train the ANN. The electrical network was then simulated to forecast peak power for the following 11 years. The calculated error was then used for years in which power consumption data were not available. The study demonstrated that average peak power rates increased by 4100 MW every 5 years. Various scenarios related to changes in population, the number of buildings, and the quantity of A/C units were then modelled to estimate long-term peak power demand. Results of the study demonstrated that population had the strongest impact on future power demand, while the number of buildings had the smallest impact. It was concluded that peak power growth can be controlled through the use of different immigration policies, increased A/C efficiency, and the use of vertical housing. 7 refs., 2 tabs., 6 figs

  19. Electric peak power forecasting by year 2025

    Energy Technology Data Exchange (ETDEWEB)

    Alsayegh, O.A.; Al-Matar, O.A.; Fairouz, F.A.; Al-Mulla Ali, A. [Kuwait Inst. for Scientific Research, Kuwait City (Kuwait). Div. of Environment and Urban Development

    2005-07-01

    Peak power demand in Kuwait up to the year 2025 was predicted using an artificial neural network (ANN) model. The aim of the study was to investigate the effect of air conditioning (A/C) units on long-term power demand. Five socio-economic factors were selected as inputs for the simulation: (1) gross national product, (2) population, (3) number of buildings, (4) imports of A/C units, and (5) index of industrial production. The study used socio-economic data from 1978 to 2000. Historical data of the first 10 years of the studied time period were used to train the ANN. The electrical network was then simulated to forecast peak power for the following 11 years. The calculated error was then used for years in which power consumption data were not available. The study demonstrated that average peak power rates increased by 4100 MW every 5 years. Various scenarios related to changes in population, the number of buildings, and the quantity of A/C units were then modelled to estimate long-term peak power demand. Results of the study demonstrated that population had the strongest impact on future power demand, while the number of buildings had the smallest impact. It was concluded that peak power growth can be controlled through the use of different immigration policies, increased A/C efficiency, and the use of vertical housing. 7 refs., 2 tabs., 6 figs.

  20. Projected change in characteristics of near surface temperature inversions for southeast Australia

    Science.gov (United States)

    Ji, Fei; Evans, Jason Peter; Di Luca, Alejandro; Jiang, Ningbo; Olson, Roman; Fita, Lluis; Argüeso, Daniel; Chang, Lisa T.-C.; Scorgie, Yvonne; Riley, Matt

    2018-05-01

    Air pollution has significant impacts on human health. Temperature inversions, especially near surface temperature inversions, can amplify air pollution by preventing convective movements and trapping pollutants close to the ground, thus decreasing air quality and increasing health issues. This effect of temperature inversions implies that trends in their frequency, strength and duration can have important implications for air quality. In this study, we evaluate the ability of three reanalysis-driven high-resolution regional climate model (RCM) simulations to represent near surface inversions at 9 sounding sites in southeast Australia. Then we use outputs of 12 historical and future RCM simulations (each with three time periods: 1990-2009, 2020-2039, and 2060-2079) from the NSW/ACT (New South Wales/Australian Capital Territory) Regional Climate Modelling (NARCliM) project to investigate changes in near surface temperature inversions. The results show that there is a substantial increase in the strength of near surface temperature inversions over southeast Australia which suggests that future inversions may intensify poor air quality events. Near surface inversions and their future changes have clear seasonal and diurnal variations. The largest differences between simulations are associated with the driving GCMs, suggesting that the large-scale circulation plays a dominant role in near surface inversion strengths.

  1. Seasonal Affective Disorder

    Science.gov (United States)

    ... than any non-seasonal depressions. Symptoms of Major Depression Feeling depressed most of the day, nearly every ... Bethesda, MD 20892-9663 Follow Us Facebook Twitter YouTube Google Plus NIMH Newsletter NIMH RSS Feed NIMH ...

  2. CCAA seasonal forecasting

    International Development Research Centre (IDRC) Digital Library (Canada)

    Integrating meteorological and indigenous knowledge-based seasonal climate forecasts in ..... Explanation is based on spiritual and social values. Taught by .... that provided medicine and food became the subject of strict rules and practices ...

  3. SPANISH PEAKS WILDERNESS STUDY AREA, COLORADO.

    Science.gov (United States)

    Budding, Karin E.; Kluender, Steven E.

    1984-01-01

    A geologic and geochemical investigation and a survey of mines and prospects were conducted to evaluate the mineral-resource potential of the Spanish Peaks Wilderness Study Area, Huerfano and Las Animas Counties, in south-central Colorado. Anomalous gold, silver, copper, lead, and zinc concentrations in rocks and in stream sediments from drainage basins in the vicinity of the old mines and prospects on West Spanish Peak indicate a substantiated mineral-resource potential for base and precious metals in the area surrounding this peak; however, the mineralized veins are sparse, small in size, and generally low in grade. There is a possibility that coal may underlie the study area, but it would be at great depth and it is unlikely that it would have survived the intense igneous activity in the area. There is little likelihood for the occurrence of oil and gas because of the lack of structural traps and the igneous activity.

  4. Analysis of fuel end-temperature peaking

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z.; Jiang, Q.; Lai, L.; Shams, M. [CANDU Energy Inc., Fuel Engineering Dept., Mississauga, Ontario (Canada)

    2013-07-01

    During normal operation and refuelling of CANDU® fuel, fuel temperatures near bundle ends will increase due to a phenomenon called end flux peaking. Similar phenomenon would also be expected to occur during a postulated large break LOCA event. The end flux peaking in a CANDU fuel element is due to the fact that neutron flux is higher near a bundle end, in contact with a neighbouring bundle or close to heavy water coolant, than in the bundle mid-plane, because of less absorption of thermal neutrons by Zircaloy or heavy water than by the UO{sub 2} material. This paper describes Candu Energy experience in analysing behaviour of bundle due to end flux peaking using fuel codes FEAT, ELESTRES and ELOCA. (author)

  5. Seasonal variation in human reproduction: environmental factors.

    Science.gov (United States)

    Bronson, F H

    1995-06-01

    Almost all human populations exhibit seasonal variation in births, owing mostly to seasonal variation in the frequency of conception. This review focuses on the degree to which environmental factors like nutrition, temperature and photoperiod contribute to these seasonal patterns by acting directly on the reproductive axis. The reproductive strategy of humans is basically that of the apes: Humans have the capacity to reproduce continuously, albeit slowly, unless inhibited by environmental influences. Two, and perhaps three, environmental factors probably act routinely as seasonal inhibitors in some human populations. First, it seems likely that ovulation is regulated seasonally in populations experiencing seasonal variation in food availability. More specifically, it seems likely that inadequate food intake or the increased energy expenditure required to obtain food, or both, can delay menarche, suppress the frequency of ovulation in the nonlactating adult, and prolong lactational amenorrhea in these populations on a seasonal basis. This action is most easily seen in tropical subsistence societies where food availability often varies greatly owing to seasonal variation in rainfall; hence births in these populations often correlate with rainfall. Second, it seems likely that seasonally high temperatures suppress spermatogenesis enough to influence the incidence of fertilization in hotter latitudes, but possibly only in males wearing clothing that diminishes scrotal cooling. Since most of our knowledge about this phenomenon comes from temperate latitudes, the sensitivity of spermatogenesis in both human and nonhuman primates to heat in the tropics needs further study. It is quite possible that high temperatures suppress ovulation and early embryo survival seasonally in some of these same populations. Since we know less than desired about the effect of heat stress on ovulation and early pregnancy in nonhuman mammals, and nothing at all about it in humans or any of the

  6. Inverse source problems in elastodynamics

    Science.gov (United States)

    Bao, Gang; Hu, Guanghui; Kian, Yavar; Yin, Tao

    2018-04-01

    We are concerned with time-dependent inverse source problems in elastodynamics. The source term is supposed to be the product of a spatial function and a temporal function with compact support. We present frequency-domain and time-domain approaches to show uniqueness in determining the spatial function from wave fields on a large sphere over a finite time interval. The stability estimate of the temporal function from the data of one receiver and the uniqueness result using partial boundary data are proved. Our arguments rely heavily on the use of the Fourier transform, which motivates inversion schemes that can be easily implemented. A Landweber iterative algorithm for recovering the spatial function and a non-iterative inversion scheme based on the uniqueness proof for recovering the temporal function are proposed. Numerical examples are demonstrated in both two and three dimensions.

  7. Inversion of the star transform

    International Nuclear Information System (INIS)

    Zhao, Fan; Schotland, John C; Markel, Vadim A

    2014-01-01

    We define the star transform as a generalization of the broken ray transform introduced by us in previous work. The advantages of using the star transform include the possibility to reconstruct the absorption and the scattering coefficients of the medium separately and simultaneously (from the same data) and the possibility to utilize scattered radiation which, in the case of conventional x-ray tomography, is discarded. In this paper, we derive the star transform from physical principles, discuss its mathematical properties and analyze numerical stability of inversion. In particular, it is shown that stable inversion of the star transform can be obtained only for configurations involving odd number of rays. Several computationally-efficient inversion algorithms are derived and tested numerically. (paper)

  8. Inverse comptonization vs. thermal synchrotron

    International Nuclear Information System (INIS)

    Fenimore, E.E.; Klebesadel, R.W.; Laros, J.G.

    1983-01-01

    There are currently two radiation mechanisms being considered for gamma-ray bursts: thermal synchrotron and inverse comptonization. They are mutually exclusive since thermal synchrotron requires a magnetic field of approx. 10 12 Gauss whereas inverse comptonization cannot produce a monotonic spectrum if the field is larger than 10 11 and is too inefficient relative to thermal synchrotron unless the field is less than 10 9 Gauss. Neither mechanism can explain completely the observed characteristics of gamma-ray bursts. However, we conclude that thermal synchrotron is more consistent with the observations if the sources are approx. 40 kpc away whereas inverse comptonization is more consistent if they are approx. 300 pc away. Unfortunately, the source distance is still not known and, thus, the radiation mechanism is still uncertain

  9. Inverse photoemission of uranium oxides

    International Nuclear Information System (INIS)

    Roussel, P.; Morrall, P.; Tull, S.J.

    2009-01-01

    Understanding the itinerant-localised bonding role of the 5f electrons in the light actinides will afford an insight into their unusual physical and chemical properties. In recent years, the combination of core and valance band electron spectroscopies with theoretic modelling have already made significant progress in this area. However, information of the unoccupied density of states is still scarce. When compared to the forward photoemission techniques, measurements of the unoccupied states suffer from significantly less sensitivity and lower resolution. In this paper, we report on our experimental apparatus, which is designed to measure the inverse photoemission spectra of the light actinides. Inverse photoemission spectra of UO 2 and UO 2.2 along with the corresponding core and valance electron spectra are presented in this paper. UO 2 has been reported previously, although through its inclusion here it allows us to compare and contrast results from our experimental apparatus to the previous Bremsstrahlung Isochromat Spectroscopy and Inverse Photoemission Spectroscopy investigations

  10. Optimization for nonlinear inverse problem

    International Nuclear Information System (INIS)

    Boyadzhiev, G.; Brandmayr, E.; Pinat, T.; Panza, G.F.

    2007-06-01

    The nonlinear inversion of geophysical data in general does not yield a unique solution, but a single model, representing the investigated field, is preferred for an easy geological interpretation of the observations. The analyzed region is constituted by a number of sub-regions where the multi-valued nonlinear inversion is applied, which leads to a multi-valued solution. Therefore, combining the values of the solution in each sub-region, many acceptable models are obtained for the entire region and this complicates the geological interpretation of geophysical investigations. In this paper are presented new methodologies, capable to select one model, among all acceptable ones, that satisfies different criteria of smoothness in the explored space of solutions. In this work we focus on the non-linear inversion of surface waves dispersion curves, which gives structural models of shear-wave velocity versus depth, but the basic concepts have a general validity. (author)

  11. Some Phenomena on Negative Inversion Constructions

    Science.gov (United States)

    Sung, Tae-Soo

    2013-01-01

    We examine the characteristics of NDI (negative degree inversion) and its relation with other inversion phenomena such as SVI (subject-verb inversion) and SAI (subject-auxiliary inversion). The negative element in the NDI construction may be" not," a negative adverbial, or a negative verb. In this respect, NDI has similar licensing…

  12. The Inverse of Banded Matrices

    Science.gov (United States)

    2013-01-01

    indexed entries all zeros. In this paper, generalizing a method of Mallik (1999) [5], we give the LU factorization and the inverse of the matrix Br,n (if it...r ≤ i ≤ r, 1 ≤ j ≤ r, with the remaining un-indexed entries all zeros. In this paper generalizing a method of Mallik (1999) [5...matrices and applications to piecewise cubic approximation, J. Comput. Appl. Math. 8 (4) (1982) 285–288. [5] R.K. Mallik , The inverse of a lower

  13. Size Estimates in Inverse Problems

    KAUST Repository

    Di Cristo, Michele

    2014-01-06

    Detection of inclusions or obstacles inside a body by boundary measurements is an inverse problems very useful in practical applications. When only finite numbers of measurements are available, we try to detect some information on the embedded object such as its size. In this talk we review some recent results on several inverse problems. The idea is to provide constructive upper and lower estimates of the area/volume of the unknown defect in terms of a quantity related to the work that can be expressed with the available boundary data.

  14. -Dimensional Fractional Lagrange's Inversion Theorem

    Directory of Open Access Journals (Sweden)

    F. A. Abd El-Salam

    2013-01-01

    Full Text Available Using Riemann-Liouville fractional differential operator, a fractional extension of the Lagrange inversion theorem and related formulas are developed. The required basic definitions, lemmas, and theorems in the fractional calculus are presented. A fractional form of Lagrange's expansion for one implicitly defined independent variable is obtained. Then, a fractional version of Lagrange's expansion in more than one unknown function is generalized. For extending the treatment in higher dimensions, some relevant vectors and tensors definitions and notations are presented. A fractional Taylor expansion of a function of -dimensional polyadics is derived. A fractional -dimensional Lagrange inversion theorem is proved.

  15. Darwin's "strange inversion of reasoning".

    Science.gov (United States)

    Dennett, Daniel

    2009-06-16

    Darwin's theory of evolution by natural selection unifies the world of physics with the world of meaning and purpose by proposing a deeply counterintuitive "inversion of reasoning" (according to a 19th century critic): "to make a perfect and beautiful machine, it is not requisite to know how to make it" [MacKenzie RB (1868) (Nisbet & Co., London)]. Turing proposed a similar inversion: to be a perfect and beautiful computing machine, it is not requisite to know what arithmetic is. Together, these ideas help to explain how we human intelligences came to be able to discern the reasons for all of the adaptations of life, including our own.

  16. Inverse transport theory and applications

    International Nuclear Information System (INIS)

    Bal, Guillaume

    2009-01-01

    Inverse transport consists of reconstructing the optical properties of a domain from measurements performed at the domain's boundary. This review concerns several types of measurements: time-dependent, time-independent, angularly resolved and angularly averaged measurements. We review recent results on the reconstruction of the optical parameters from such measurements and the stability of such reconstructions. Inverse transport finds applications e.g. in medical imaging (optical tomography, optical molecular imaging) and in geophysical imaging (remote sensing in the Earth's atmosphere). (topical review)

  17. Inverse Interval Matrix: A Survey

    Czech Academy of Sciences Publication Activity Database

    Rohn, Jiří; Farhadsefat, R.

    2011-01-01

    Roč. 22, - (2011), s. 704-719 E-ISSN 1081-3810 R&D Projects: GA ČR GA201/09/1957; GA ČR GC201/08/J020 Institutional research plan: CEZ:AV0Z10300504 Keywords : interval matrix * inverse interval matrix * NP-hardness * enclosure * unit midpoint * inverse sign stability * nonnegative invertibility * absolute value equation * algorithm Subject RIV: BA - General Mathematics Impact factor: 0.808, year: 2010 http://www.math.technion.ac.il/iic/ ela / ela -articles/articles/vol22_pp704-719.pdf

  18. Climate-related variation in plant peak biomass and growth phenology across Pacific Northwest tidal marshes

    Science.gov (United States)

    Buffington, Kevin J.; Dugger, Bruce D.; Thorne, Karen M.

    2018-01-01

    The interannual variability of tidal marsh plant phenology is largely unknown and may have important ecological consequences. Marsh plants are critical to the biogeomorphic feedback processes that build estuarine soils, maintain marsh elevation relative to sea level, and sequester carbon. We calculated Tasseled Cap Greenness, a metric of plant biomass, using remotely sensed data available in the Landsat archive to assess how recent climate variation has affected biomass production and plant phenology across three maritime tidal marshes in the Pacific Northwest of the United States. First, we used clipped vegetation plots at one of our sites to confirm that tasseled cap greenness provided a useful measure of aboveground biomass (r2 = 0.72). We then used multiple measures of biomass each growing season over 20–25 years per study site and developed models to test how peak biomass and the date of peak biomass varied with 94 climate and sea-level metrics using generalized linear models and Akaike Information Criterion (AIC) model selection. Peak biomass was positively related to total annual precipitation, while the best predictor for date of peak biomass was average growing season temperature, with the peak 7.2 days earlier per degree C. Our study provides insight into how plants in maritime tidal marshes respond to interannual climate variation and demonstrates the utility of time-series remote sensing data to assess ecological responses to climate stressors.

  19. Climate-related variation in plant peak biomass and growth phenology across Pacific Northwest tidal marshes

    Science.gov (United States)

    Buffington, Kevin J.; Dugger, Bruce D.; Thorne, Karen M.

    2018-03-01

    The interannual variability of tidal marsh plant phenology is largely unknown and may have important ecological consequences. Marsh plants are critical to the biogeomorphic feedback processes that build estuarine soils, maintain marsh elevation relative to sea level, and sequester carbon. We calculated Tasseled Cap Greenness, a metric of plant biomass, using remotely sensed data available in the Landsat archive to assess how recent climate variation has affected biomass production and plant phenology across three maritime tidal marshes in the Pacific Northwest of the United States. First, we used clipped vegetation plots at one of our sites to confirm that tasseled cap greenness provided a useful measure of aboveground biomass (r2 = 0.72). We then used multiple measures of biomass each growing season over 20-25 years per study site and developed models to test how peak biomass and the date of peak biomass varied with 94 climate and sea-level metrics using generalized linear models and Akaike Information Criterion (AIC) model selection. Peak biomass was positively related to total annual precipitation, while the best predictor for date of peak biomass was average growing season temperature, with the peak 7.2 days earlier per degree C. Our study provides insight into how plants in maritime tidal marshes respond to interannual climate variation and demonstrates the utility of time-series remote sensing data to assess ecological responses to climate stressors.

  20. Osteoporosis: Peak Bone Mass in Women

    Science.gov (United States)

    ... bone density are seen even during childhood and adolescence. Hormonal factors. The hormone estrogen has an effect on peak bone mass. For example, women who had their first menstrual cycle at an early age and those who use oral contraceptives, which contain estrogen, often have high bone mineral ...

  1. Facility Location with Double-peaked Preferences

    DEFF Research Database (Denmark)

    Filos-Ratsikas, Aris; Li, Minming; Zhang, Jie

    2015-01-01

    ; this makes the problem essentially more challenging. As our main contribution, we present a simple truthful-in-expectation mechanism that achieves an approximation ratio of 1+b=c for both the social and the maximum, cost, where b is the distance of the agent from the peak and c is the minimum cost...

  2. Robust Peak Recognition in Intracranial Pressure Signals

    Directory of Open Access Journals (Sweden)

    Bergsneider Marvin

    2010-10-01

    Full Text Available Abstract Background The waveform morphology of intracranial pressure pulses (ICP is an essential indicator for monitoring, and forecasting critical intracranial and cerebrovascular pathophysiological variations. While current ICP pulse analysis frameworks offer satisfying results on most of the pulses, we observed that the performance of several of them deteriorates significantly on abnormal, or simply more challenging pulses. Methods This paper provides two contributions to this problem. First, it introduces MOCAIP++, a generic ICP pulse processing framework that generalizes MOCAIP (Morphological Clustering and Analysis of ICP Pulse. Its strength is to integrate several peak recognition methods to describe ICP morphology, and to exploit different ICP features to improve peak recognition. Second, it investigates the effect of incorporating, automatically identified, challenging pulses into the training set of peak recognition models. Results Experiments on a large dataset of ICP signals, as well as on a representative collection of sampled challenging ICP pulses, demonstrate that both contributions are complementary and significantly improve peak recognition performance in clinical conditions. Conclusion The proposed framework allows to extract more reliable statistics about the ICP waveform morphology on challenging pulses to investigate the predictive power of these pulses on the condition of the patient.

  3. Liquid waste processing at Comanche Peak

    International Nuclear Information System (INIS)

    Hughes-Edwards, L.M.; Edwards, J.M.

    1996-01-01

    This article describes the radioactive waste processing at Comanche Peak Steam Electric Station. Topics covered are the following: Reduction of liquid radioactive discharges (system leakage, outage planning); reduction of waste resin generation (waste stream segregation, processing methodology); reduction of activity released and off-site dose. 8 figs., 2 tabs

  4. Avoiding the False Peaks in Correlation Discrimination

    International Nuclear Information System (INIS)

    Awwal, A.S.

    2009-01-01

    Fiducials imprinted on laser beams are used to perform video image based alignment of the 192 laser beams in the National Ignition Facility (NIF) of Lawrence Livermore National Laboratory. In many video images, matched filtering is used to detect the location of these fiducials. Generally, the highest correlation peak is used to determine the position of the fiducials. However, when the signal to-be-detected is very weak compared to the noise, this approach totally breaks down. The highest peaks act as traps for false detection. The active target images used for automatic alignment in the National Ignition Facility are examples of such images. In these images, the fiducials of interest exhibit extremely low intensity and contrast, surrounded by high intensity reflection from metallic objects. Consequently, the highest correlation peaks are caused by these bright objects. In this work, we show how the shape of the correlation is exploited to isolate the valid matches from hundreds of invalid correlation peaks, and therefore identify extremely faint fiducials under very challenging imaging conditions

  5. Hubbert's Peak: the Impending World oil Shortage

    Science.gov (United States)

    Deffeyes, K. S.

    2004-12-01

    Global oil production will probably reach a peak sometime during this decade. After the peak, the world's production of crude oil will fall, never to rise again. The world will not run out of energy, but developing alternative energy sources on a large scale will take at least 10 years. The slowdown in oil production may already be beginning; the current price fluctuations for crude oil and natural gas may be the preamble to a major crisis. In 1956, the geologist M. King Hubbert predicted that U.S. oil production would peak in the early 1970s.1 Almost everyone, inside and outside the oil industry, rejected Hubbert's analysis. The controversy raged until 1970, when the U.S. production of crude oil started to fall. Hubbert was right. Around 1995, several analysts began applying Hubbert's method to world oil production, and most of them estimate that the peak year for world oil will be between 2004 and 2008. These analyses were reported in some of the most widely circulated sources: Nature, Science, and Scientific American.2 None of our political leaders seem to be paying attention. If the predictions are correct, there will be enormous effects on the world economy. Even the poorest nations need fuel to run irrigation pumps. The industrialized nations will be bidding against one another for the dwindling oil supply. The good news is that we will put less carbon dioxide into the atmosphere. The bad news is that my pickup truck has a 25-gallon tank.

  6. Seasonal varability of the Canary Current

    Science.gov (United States)

    Vélez-Belchí, P.; Hernandez-Guerra, A.; Pérez-Hernández, M. D.

    2016-02-01

    The Atlantic meridional overturning circulation (AMOC) is recognized as an important component of the climate system, contributing to the relatively mild climate of northwest Europe. Due to its importance, the strength of the AMOC is continually monitored along 26ºN with several moorings, east of the Bahamas, in the Middle Atlantic Ridge and south of the Canary islands, known as the RAPID array. The measurements of the RAPID array show a 6 Sv seasonal cycle for the AMOC, and recent studies have pointed out the dynamics of the eastern Atlantic as the main driver for this seasonal cycle, specifically, rossby waves excited south of the Canary Islands.Due to the important role of the eastern Atlantic, in this study we describe the seasonal cycle of the Canary Current (CC) and the Canary Upwelling Current (CUC), using hydrographic data from two cruises carried out in a box around the Canary Islands, the region where the eastern component of the RAPID array is placed. CTD, VMADCP and LADCP data were combined with inverse modeling in order to determine absolute geostrophic transports in the Canary Islands region in fall and spring. During spring, the overall transport of Canary Current and the CUC was southward. In the Lanzarote Passage (LP), between the Canary Islands and Africa, the CUC transported 0.6±0.20 Sv southward, while the Canary Current transported 1.0±0.40 Sv in the oceanic waters of the Canary Islands Archipelago. During fall, the CUC transported 2.8±0.4Sv northward, while the CC transported 2.9±0.60 Sv southward in the oceanic waters of the Canary Islands Archipelago. The seasonal cycle observed has and amplitude of 3.4Sv for the CUC and 1.9Sv for the CC. Data from a mooring in the LP and the hydrographic data was used to calibrate geostrophic transport estimated using altimetry data. The amplitude of the seasonal cycle of the geostrophic transport obtained using the calibrated altimetry data (Figure 1) was quite similar to the seasonal cycle of the

  7. Seasonal cycle of the Canary Current.

    Science.gov (United States)

    Vélez-Belchí, P.; Hernandez-Guerra, A.; Pérez-Hernández, M. D.

    2015-12-01

    The Atlantic meridional overturning circulation (AMOC) is recognized as an important component of the climate system, contributing to the relatively mild climate of northwest Europe. Due to its importance, the strength of the AMOC is continually monitored along 26ºN with several moorings east of the Bahamas, in the Middle Atlantic Ridge and south of the Canary islands, known as the RAPID array. The measurements of the RAPID array show a 6 Sv seasonal cycle for the AMOC, and recent studies have pointed out the dynamics of the eastern Atlantic as the main driver for this seasonal cycle, specifically, rossby waves excited south of the Canary Islands. Due to the important role of the eastern Atlantic, in this study we describe the seasonal cycle of the Canary Current (CC) and the Canary Upwelling Current (CUC) using hydrographic data from two cruises carried out in a box around the Canary Islands, the region where the eastern component of the RAPID array is placed. CTD, VMADCP and LADCP data were combined with inverse modeling in order to determine absolute geostrophic transports in the Canary Islands region in fall and spring. During spring, the overall transport of Canary Current and the CUC was southward. In the Lanzarote Passage (LP), between the Canary Islands and Africa, the CUC transported 0.6±0.20 Sv southward, while the Canary Current transported 1.0±0.40 Sv in the oceanic waters of the Canary Islands Archipelago. During fall, the CUC transported 2.8±0.4Sv northward, while the CC transported 2.9±0.60 Sv southward in the oceanic waters of the Canary Islands Archipelago. The seasonal cycle observed has an amplitude of 3.4Sv for the CUC and 1.9Sv for the CC. Data from a mooring in the LP and the hydrographic data was used to calibrate geostrophic transport estimated using altimetry data. The amplitude of the seasonal cycle of the geostrophic transport obtained using the calibrated altimetry data (Figure 1) was quite similar to the seasonal cycle of the

  8. Isomorphs in the phase diagram of a model liquid without inverse power law repulsion

    DEFF Research Database (Denmark)

    Veldhorst, Arnold Adriaan; Bøhling, Lasse; Dyre, J. C.

    2012-01-01

    scattering function are calculated. The results are shown to reflect a hidden scale invariance; despite its exponential repulsion the Buckingham potential is well approximated by an inverse power-law plus a linear term in the region of the first peak of the radial distribution function. As a consequence...... the dynamics of the viscous Buckingham liquid is mimicked by a corresponding model with purely repulsive inverse-power-law interactions. The results presented here closely resemble earlier results for Lennard-Jones type liquids, demonstrating that the existence of strong correlations and isomorphs does...... not depend critically on the mathematical form of the repulsion being an inverse power law....

  9. A thermally tunable inverse opal photonic crystal for monitoring glass transition.

    Science.gov (United States)

    Sun, Liguo; Xie, Zhuoying; Xu, Hua; Xu, Ming; Han, Guozhi; Wang, Cheng; Bai, Xuduo; Gu, ZhongZe

    2012-03-01

    An optical method was developed to monitor the glass transition of the polymer by taking advantage of reflection spectrum change of the thermally tunable inverse opal photonic crystal. The thermally tunable photonic bands of the polymer inverse opal photonic crystal were traceable to the segmental motion of macromolecules, and the segmental motion was temperature dependent. By observing the reflection spectrum change of the polystyrene inverse opal photonic crystal during thermal treatment, the glass transition temperature of polystyrene was gotten. Both changes of the position and intensity of the reflection peak were observed during the glass transition process of the polystyrene inverse opal photonic crystal. The optical change of inverse opal photonic crystal was so large that the glass transition temperature could even be estimated by naked eyes. The glass transition temperature derived from this method was consistent with the values measured by differential scanning calorimeter.

  10. Prediction of peak overlap in NMR spectra

    International Nuclear Information System (INIS)

    Hefke, Frederik; Schmucki, Roland; Güntert, Peter

    2013-01-01

    Peak overlap is one of the major factors complicating the analysis of biomolecular NMR spectra. We present a general method for predicting the extent of peak overlap in multidimensional NMR spectra and its validation using both, experimental data sets and Monte Carlo simulation. The method is based on knowledge of the magnetization transfer pathways of the NMR experiments and chemical shift statistics from the Biological Magnetic Resonance Data Bank. Assuming a normal distribution with characteristic mean value and standard deviation for the chemical shift of each observable atom, an analytic expression was derived for the expected overlap probability of the cross peaks. The analytical approach was verified to agree with the average peak overlap in a large number of individual peak lists simulated using the same chemical shift statistics. The method was applied to eight proteins, including an intrinsically disordered one, for which the prediction results could be compared with the actual overlap based on the experimentally measured chemical shifts. The extent of overlap predicted using only statistical chemical shift information was in good agreement with the overlap that was observed when the measured shifts were used in the virtual spectrum, except for the intrinsically disordered protein. Since the spectral complexity of a protein NMR spectrum is a crucial factor for protein structure determination, analytical overlap prediction can be used to identify potentially difficult proteins before conducting NMR experiments. Overlap predictions can be tailored to particular classes of proteins by preparing statistics from corresponding protein databases. The method is also suitable for optimizing recording parameters and labeling schemes for NMR experiments and improving the reliability of automated spectra analysis and protein structure determination.

  11. The peak in anomalous magnetic viscosity

    International Nuclear Information System (INIS)

    Collocott, S.J.; Watterson, P.A.; Tan, X.H.; Xu, H.

    2014-01-01

    Anomalous magnetic viscosity, where the magnetization as a function of time exhibits non-monotonic behaviour, being seen to increase, reach a peak, and then decrease, is observed on recoil lines in bulk amorphous ferromagnets, for certain magnetic prehistories. A simple geometrical approach based on the motion of the state line on the Preisach plane gives a theoretical framework for interpreting non-monotonic behaviour and explains the origin of the peak. This approach gives an expression for the time taken to reach the peak as a function of the applied (or holding) field. The theory is applied to experimental data for bulk amorphous ferromagnet alloys of composition Nd 60−x Fe 30 Al 10 Dy x , x = 0, 1, 2, 3 and 4, and it gives a reasonable description of the observed behaviour. The role played by other key magnetic parameters, such as the intrinsic coercivity and fluctuation field, is also discussed. When the non-monotonic behaviour of the magnetization of a number of alloys is viewed in the context of the model, features of universal behaviour emerge, that are independent of alloy composition. - Highlights: • Development of a simple geometrical model based on the Preisach model which gives a complete explanation of the peak in the magnetic viscosity. • Geometrical approach is extended by considering equations that govern the motion of the state line. • The model is used to deduce the relationship between the holding field and the time it takes to reach the peak. • The model is tested with experimental results for a range of Nd–Fe–Al–Dy bulk amorphous ferromagnets. • There is good agreement between the model and the experimental data

  12. The spatial resolution of epidemic peaks.

    Directory of Open Access Journals (Sweden)

    Harriet L Mills

    2014-04-01

    Full Text Available The emergence of novel respiratory pathogens can challenge the capacity of key health care resources, such as intensive care units, that are constrained to serve only specific geographical populations. An ability to predict the magnitude and timing of peak incidence at the scale of a single large population would help to accurately assess the value of interventions designed to reduce that peak. However, current disease-dynamic theory does not provide a clear understanding of the relationship between: epidemic trajectories at the scale of interest (e.g. city; population mobility; and higher resolution spatial effects (e.g. transmission within small neighbourhoods. Here, we used a spatially-explicit stochastic meta-population model of arbitrary spatial resolution to determine the effect of resolution on model-derived epidemic trajectories. We simulated an influenza-like pathogen spreading across theoretical and actual population densities and varied our assumptions about mobility using Latin-Hypercube sampling. Even though, by design, cumulative attack rates were the same for all resolutions and mobilities, peak incidences were different. Clear thresholds existed for all tested populations, such that models with resolutions lower than the threshold substantially overestimated population-wide peak incidence. The effect of resolution was most important in populations which were of lower density and lower mobility. With the expectation of accurate spatial incidence datasets in the near future, our objective was to provide a framework for how to use these data correctly in a spatial meta-population model. Our results suggest that there is a fundamental spatial resolution for any pathogen-population pair. If underlying interactions between pathogens and spatially heterogeneous populations are represented at this resolution or higher, accurate predictions of peak incidence for city-scale epidemics are feasible.

  13. Timing of floods in southeastern China: Seasonal properties and potential causes

    Science.gov (United States)

    Zhang, Qiang; Gu, Xihui; Singh, Vijay P.; Shi, Peijun; Luo, Ming

    2017-09-01

    Flood hazards and flood risks in southeastern China have been causing increasing concerns due to dense population and highly-developed economy. This study attempted to address changes of seasonality, timing of peak floods and variability of occurrence date of peak floods using circular statistical methods and the modified Mann-Kendall trend detection method. The causes of peak flood changes were also investigated. Results indicated that: (1) floods were subject to more seasonality and temporal clustering when compared to precipitation extremes. However, seasonality of floods and extreme precipitation was subject to spatial heterogeneity in northern Guangdong. Similar changing patterns of peak floods and extreme precipitation were found in coastal regions; (2) significant increasing/decreasing seasonality, but no confirmed spatial patterns, were observed for peak floods and extreme precipitation. Peak floods in northern Guangdong province had decreasing variability, but had larger variability in coastal regions; (3) tropical cyclones had remarkable impacts on extreme precipitation changes in coastal regions of southeastern China, and peak floods as well. The landfalling of tropical cyclones was decreasing and concentrated during June-September; this is the major reason for earlier but enhanced seasonality of peak floods in coastal regions. This study sheds new light on flood behavior in coastal regions in a changing environment.

  14. A prospective population study of resting heart rate and peak oxygen uptake (the HUNT Study, Norway.

    Directory of Open Access Journals (Sweden)

    Javaid Nauman

    Full Text Available OBJECTIVES: We assessed the prospective association of resting heart rate (RHR at baseline with peak oxygen uptake (VO(2peak 23 years later, and evaluated whether physical activity (PA could modify this association. BACKGROUND: Both RHR and VO(2peak are strong and independent predictors of cardiovascular morbidity and mortality. However, the association of RHR with VO(2peak and modifying effect of PA have not been prospectively assessed in population studies. METHODS: In 807 men and 810 women free from cardiovascular disease both at baseline (1984-86 and follow-up 23 years later, RHR was recorded at both occasions, and VO(2peak was measured by ergospirometry at follow-up. We used Generalized Linear Models to assess the association of baseline RHR with VO(2peak, and to study combined effects of RHR and self-reported PA on later VO(2peak. RESULTS: There was an inverse association of RHR at baseline with VO(2peak (p<0.01. Men and women with baseline RHR greater than 80 bpm had 4.6 mL.kg(-1.min(-1 (95% confidence interval [CI], 2.8 to 6.3 and 1.4 mL.kg(-1.min(-1 (95% CI, -0.4 to 3.1 lower VO(2peak at follow-up compared with men and women with RHR below 60 bpm at baseline. We found a linear association of change in RHR with VO(2peak (p=0.03, suggesting that a decrease in RHR over time is likely to be beneficial for cardiovascular fitness. Participants with low RHR and high PA at baseline had higher VO(2peak than inactive people with relatively high RHR. However, among participants with relatively high RHR and high PA at baseline, VO(2peak was similar to inactive people with relatively low RHR. CONCLUSION: RHR is an important predictor of VO(2peak, and serial assessments of RHR may provide useful and inexpensive information on cardiovascular fitness. The results suggest that high levels of PA may compensate for the lower VO(2peak associated with a high RHR.

  15. Seasonal and age-related changes in the micro-anatomy of the ...

    African Journals Online (AJOL)

    Peak prostate mass, alveoli diameter and secretory cell height indi- cate that ... Recently. attention was accorded to the seasonal reproductive cycle of male fur seals ... The sam- pling procedure was selective to include all age groups. Body.

  16. Variation of respiratory syncytial virus and the relation with meteorological factors in different winter seasons.

    NARCIS (Netherlands)

    Meerhoff, T.J.; Paget, W.J.; Kimpen, J.L.; Schellevis, F.

    2009-01-01

    Background: Respiratory syncytial virus (RSV) is the most important viral agent causing severe respiratory disease in infants and children. In temperate climates, RSV activity typically peaks during winter. We have described the seasonal variation in RSV activity and investigated which

  17. Seasonal variability in penaeid prawn larval abundance in the Mandovi and Zuari estuaries, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Goswami, U.

    more in the bottom samples. Based on larval density, M. dobsoni appeared to be a continuous breeder. The active spawning periods in other species were during the late postmonsoon and premonsoon seasons varying with the species. Peak recruitment...

  18. Inverse problem of solar oscillations

    International Nuclear Information System (INIS)

    Sekii, T.; Shibahashi, H.

    1987-01-01

    The authors present some preliminary results of numerical simulation to infer the sound velocity distribution in the solar interior from the oscillation data of the Sun as the inverse problem. They analyze the acoustic potential itself by taking account of some factors other than the sound velocity, and infer the sound velocity distribution in the deep interior of the Sun

  19. Wave-equation dispersion inversion

    KAUST Repository

    Li, Jing

    2016-12-08

    We present the theory for wave-equation inversion of dispersion curves, where the misfit function is the sum of the squared differences between the wavenumbers along the predicted and observed dispersion curves. The dispersion curves are obtained from Rayleigh waves recorded by vertical-component geophones. Similar to wave-equation traveltime tomography, the complicated surface wave arrivals in traces are skeletonized as simpler data, namely the picked dispersion curves in the phase-velocity and frequency domains. Solutions to the elastic wave equation and an iterative optimization method are then used to invert these curves for 2-D or 3-D S-wave velocity models. This procedure, denoted as wave-equation dispersion inversion (WD), does not require the assumption of a layered model and is significantly less prone to the cycle-skipping problems of full waveform inversion. The synthetic and field data examples demonstrate that WD can approximately reconstruct the S-wave velocity distributions in laterally heterogeneous media if the dispersion curves can be identified and picked. The WD method is easily extended to anisotropic data and the inversion of dispersion curves associated with Love waves.

  20. Meteorological Influences on the Seasonality of Lyme Disease in the United States

    Science.gov (United States)

    Moore, Sean M.; Eisen, Rebecca J.; Monaghan, Andrew; Mead, Paul

    2014-01-01

    Lyme disease (Borrelia burgdorferi infection) is the most common vector-transmitted disease in the United States. The majority of human Lyme disease (LD) cases occur in the summer months, but the timing of the peak occurrence varies geographically and from year to year. We calculated the beginning, peak, end, and duration of the main LD season in 12 highly endemic states from 1992 to 2007 and then examined the association between the timing of these seasonal variables and several meteorological variables. An earlier beginning to the LD season was positively associated with higher cumulative growing degree days through Week 20, lower cumulative precipitation, a lower saturation deficit, and proximity to the Atlantic coast. The timing of the peak and duration of the LD season were also associated with cumulative growing degree days, saturation deficit, and cumulative precipitation, but no meteorological predictors adequately explained the timing of the end of the LD season. PMID:24470565

  1. Novel Method of Weighting Cumulative Helmet Impacts Improves Correlation with Brain White Matter Changes After One Football Season of Sub-concussive Head Blows.

    Science.gov (United States)

    Merchant-Borna, Kian; Asselin, Patrick; Narayan, Darren; Abar, Beau; Jones, Courtney M C; Bazarian, Jeffrey J

    2016-12-01

    One football season of sub-concussive head blows has been shown to be associated with subclinical white matter (WM) changes on diffusion tensor imaging (DTI). Prior research analyses of helmet-based impact metrics using mean and peak linear and rotational acceleration showed relatively weak correlations to these WM changes; however, these analyses failed to account for the emerging concept that neuronal vulnerability to successive hits is inversely related to the time between hits (TBH). To develop a novel method for quantifying the cumulative effects of sub-concussive head blows during a single season of collegiate football by weighting helmet-based impact measures for time between helmet impacts. We further aim to compare correlations to changes in DTI after one season of collegiate football using weighted cumulative helmet-based impact measures to correlations using non-weighted cumulative helmet-based impact measures and non-cumulative measures. We performed a secondary analysis of DTI and helmet impact data collected on ten Division III collegiate football players during the 2011 season. All subjects underwent diffusion MR imaging before the start of the football season and within 1 week of the end of the football season. Helmet impacts were recorded at each practice and game using helmet-mounted accelerometers, which computed five helmet-based impact measures for each hit: linear acceleration (LA), rotational acceleration (RA), Gadd Severity Index (GSI), Head Injury Criterion (HIC 15 ), and Head Impact Technology severity profile (HITsp). All helmet-based impact measures were analyzed using five methods of summary: peak and mean (non-cumulative measures), season sum-totals (cumulative unweighted measures), and season sum-totals weighted for time between hits (TBH), the interval of time from hit to post-season DTI assessment (TUA), and both TBH and TUA combined. Summarized helmet-based impact measures were correlated to statistically significant changes in

  2. Workflows for Full Waveform Inversions

    Science.gov (United States)

    Boehm, Christian; Krischer, Lion; Afanasiev, Michael; van Driel, Martin; May, Dave A.; Rietmann, Max; Fichtner, Andreas

    2017-04-01

    Despite many theoretical advances and the increasing availability of high-performance computing clusters, full seismic waveform inversions still face considerable challenges regarding data and workflow management. While the community has access to solvers which can harness modern heterogeneous computing architectures, the computational bottleneck has fallen to these often manpower-bounded issues that need to be overcome to facilitate further progress. Modern inversions involve huge amounts of data and require a tight integration between numerical PDE solvers, data acquisition and processing systems, nonlinear optimization libraries, and job orchestration frameworks. To this end we created a set of libraries and applications revolving around Salvus (http://salvus.io), a novel software package designed to solve large-scale full waveform inverse problems. This presentation focuses on solving passive source seismic full waveform inversions from local to global scales with Salvus. We discuss (i) design choices for the aforementioned components required for full waveform modeling and inversion, (ii) their implementation in the Salvus framework, and (iii) how it is all tied together by a usable workflow system. We combine state-of-the-art algorithms ranging from high-order finite-element solutions of the wave equation to quasi-Newton optimization algorithms using trust-region methods that can handle inexact derivatives. All is steered by an automated interactive graph-based workflow framework capable of orchestrating all necessary pieces. This naturally facilitates the creation of new Earth models and hopefully sparks new scientific insights. Additionally, and even more importantly, it enhances reproducibility and reliability of the final results.

  3. Design flood hydrographs from the relationship between flood peak and volume

    Directory of Open Access Journals (Sweden)

    L. Mediero

    2010-12-01

    Full Text Available Hydrological frequency analyses are usually focused on flood peaks. Flood volumes and durations have not been studied as extensively, although there are many practical situations, such as when designing a dam, in which the full hydrograph is of interest. A flood hydrograph may be described by a multivariate function of the peak, volume and duration. Most standard bivariate and trivariate functions do not produce univariate three-parameter functions as marginal distributions, however, three-parameter functions are required to fit highly skewed data, such as flood peak and flood volume series. In this paper, the relationship between flood peak and hydrograph volume is analysed to overcome this problem. A Monte Carlo experiment was conducted to generate an ensemble of hydrographs that maintain the statistical properties of marginal distributions of the peaks, volumes and durations. This ensemble can be applied to determine the Design Flood Hydrograph (DFH for a reservoir, which is not a unique hydrograph, but rather a curve in the peak-volume space. All hydrographs on that curve have the same return period, which can be understood as the inverse of the probability to exceed a certain water level in the reservoir in any given year. The procedure can also be applied to design the length of the spillway crest in terms of the risk of exceeding a given water level in the reservoir.

  4. Does team lifting increase the variability in peak lumbar compression in ironworkers?

    Science.gov (United States)

    Faber, Gert; Visser, Steven; van der Molen, Henk F; Kuijer, P Paul F M; Hoozemans, Marco J M; Van Dieën, Jaap H; Frings-Dresen, Monique H W

    2012-01-01

    Ironworkers frequently perform heavy lifting tasks in teams of two or four workers. Team lifting could potentially lead to a higher variation in peak lumbar compression forces than lifts performed by one worker, resulting in higher maximal peak lumbar compression forces. This study compared single-worker lifts (25-kg, iron bar) to two-worker lifts (50-kg, two iron bars) and to four-worker lifts (100-kg, iron lattice). Inverse dynamics was used to calculate peak lumbar compression forces. To assess the variability in peak lumbar loading, all three lifting tasks were performed six times. Results showed that the variability in peak lumbar loading was somewhat higher in the team lifts compared to the single-worker lifts. However, despite this increased variability, team lifts did not result in larger maximum peak lumbar compression forces. Therefore, it was concluded that, from a biomechanical point of view, team lifting does not result in an additional risk for low back complaints in ironworkers.

  5. Seasonal variability of physico–chemical characteristics of the ...

    Indian Academy of Sciences (India)

    Salinity varied spatially and temporally and seasonally during ebb and flood tide conditions. ... The tidal varia- tion at the mouth is from 6.1 m at springs to 0.22 m at neaps. The fresh water discharge ranges from a peak value of 4250m3 s−1 to almost zero in the ...... National Conference on Harbour and Ocean Engineer-.

  6. Preparing for the Season (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2016-12-08

    Flu season starts in the fall and goes through the spring, typically peaking between January and March in the United States. In this podcast, Dr. Joe Bresee discusses the importance of getting vaccinated against the flu every year.  Created: 12/8/2016 by MMWR.   Date Released: 12/8/2016.

  7. Seasonal succession in zooplankton feeding traits reveals trophic trait coupling

    DEFF Research Database (Denmark)

    Kenitz, Kasia; Visser, Andre; Mariani, Patrizio

    2017-01-01

    non-motile cells flourishing in spring and motile community dominating during summer. The zooplankton community is dominated by active feeding-current feeders with peak biomass in the late spring declining during summer. The model reveals how zooplankton grazing reinforces protist plankton seasonal...

  8. Blue Oak Canopy Effect on Seasonal Forage Production and Quality

    Science.gov (United States)

    William E. Frost; Neil K. McDougald; Montague W. Demment

    1991-01-01

    Forage production and forage quality were measured seasonally beneath the canopy of blue oak (Quercus douglasii) and in open grassland at the San Joaquin Experimental Range. At the March and peak standing crop sampling dates forage production was significantly greater (p=.05) beneath blue oak compared to open grassland. At most sampling dates, the...

  9. Wave-equation Qs Inversion of Skeletonized Surface Waves

    KAUST Repository

    Li, Jing

    2017-02-08

    We present a skeletonized inversion method that inverts surface-wave data for the Qs quality factor. Similar to the inversion of dispersion curves for the S-wave velocity model, the complicated surface-wave arrivals are skeletonized as simpler data, namely the amplitude spectra of the windowed Rayleigh-wave arrivals. The optimal Qs model is the one that minimizes the difference in the peak frequencies of the predicted and observed Rayleigh wave arrivals using a gradient-based wave-equation optimization method. Solutions to the viscoelastic wave-equation are used to compute the predicted Rayleigh-wave arrivals and the misfit gradient at every iteration. This procedure, denoted as wave-equation Qs inversion (WQs), does not require the assumption of a layered model and tends to have fast and robust convergence compared to full waveform inversion (FWI). Numerical examples with synthetic and field data demonstrate that the WQs method can accurately invert for a smoothed approximation to the subsurface Qs distribution as long as the Vs model is known with sufficient accuracy.

  10. Wave-equation Qs Inversion of Skeletonized Surface Waves

    KAUST Repository

    Li, Jing; Dutta, Gaurav; Schuster, Gerard T.

    2017-01-01

    We present a skeletonized inversion method that inverts surface-wave data for the Qs quality factor. Similar to the inversion of dispersion curves for the S-wave velocity model, the complicated surface-wave arrivals are skeletonized as simpler data, namely the amplitude spectra of the windowed Rayleigh-wave arrivals. The optimal Qs model is the one that minimizes the difference in the peak frequencies of the predicted and observed Rayleigh wave arrivals using a gradient-based wave-equation optimization method. Solutions to the viscoelastic wave-equation are used to compute the predicted Rayleigh-wave arrivals and the misfit gradient at every iteration. This procedure, denoted as wave-equation Qs inversion (WQs), does not require the assumption of a layered model and tends to have fast and robust convergence compared to full waveform inversion (FWI). Numerical examples with synthetic and field data demonstrate that the WQs method can accurately invert for a smoothed approximation to the subsurface Qs distribution as long as the Vs model is known with sufficient accuracy.

  11. Stereotactic Bragg peak proton radiosurgery method

    International Nuclear Information System (INIS)

    Kjellberg, R.N.

    1979-01-01

    A brief description of the technical aspects of a stereotactic Bragg peak proton radiosurgical method for the head is presented. The preparatory radiographic studies are outlined and the stereotactic instrument and positioning of the patient are described. The instrument is so calibrated that after corrections for soft tissue and bone thickness, the Bragg peak superimposes upon the intracranial target. The head is rotated at specific intervals to allow predetermined portals of access for the beam path, all of which converge on the intracranial target. Normally, portals are arranged to oppose and overlap from both sides of the head. Using a number of beams (in sequence) on both sides of the head, the target dose is far greater than the path dose. The procedure normally takes 3/2-2 hours, following which the patient can walk away. (Auth./C.F.)

  12. Central peaking of magnetized gas discharges

    International Nuclear Information System (INIS)

    Chen, Francis F.; Curreli, Davide

    2013-01-01

    Partially ionized gas discharges used in industry are often driven by radiofrequency (rf) power applied at the periphery of a cylinder. It is found that the plasma density n is usually flat or peaked on axis even if the skin depth of the rf field is thin compared with the chamber radius a. Previous attempts at explaining this did not account for the finite length of the discharge and the boundary conditions at the endplates. A simple 1D model is used to focus on the basic mechanism: the short-circuit effect. It is found that a strong electric field (E-field) scaled to electron temperature T e , drives the ions inward. The resulting density profile is peaked on axis and has a shape independent of pressure or discharge radius. This “universal” profile is not affected by a dc magnetic field (B-field) as long as the ion Larmor radius is larger than a

  13. Peak Oil, Food Systems, and Public Health

    Science.gov (United States)

    Parker, Cindy L.; Kirschenmann, Frederick L.; Tinch, Jennifer; Lawrence, Robert S.

    2011-01-01

    Peak oil is the phenomenon whereby global oil supplies will peak, then decline, with extraction growing increasingly costly. Today's globalized industrial food system depends on oil for fueling farm machinery, producing pesticides, and transporting goods. Biofuels production links oil prices to food prices. We examined food system vulnerability to rising oil prices and the public health consequences. In the short term, high food prices harm food security and equity. Over time, high prices will force the entire food system to adapt. Strong preparation and advance investment may mitigate the extent of dislocation and hunger. Certain social and policy changes could smooth adaptation; public health has an essential role in promoting a proactive, smart, and equitable transition that increases resilience and enables adequate food for all. PMID:21778492

  14. Hanford Site peak gust wind speeds

    International Nuclear Information System (INIS)

    Ramsdell, J.V.

    1998-01-01

    Peak gust wind data collected at the Hanford Site since 1945 are analyzed to estimate maximum wind speeds for use in structural design. The results are compared with design wind speeds proposed for the Hanford Site. These comparisons indicate that design wind speeds contained in a January 1998 advisory changing DOE-STD-1020-94 are excessive for the Hanford Site and that the design wind speeds in effect prior to the changes are still appropriate for the Hanford Site

  15. Commodity hydrogen from off-peak electricity

    Energy Technology Data Exchange (ETDEWEB)

    Darrow, K.; Biederman, N.; Konopka, A.

    1977-01-01

    This paper considers the use of off-peak electrical power as an energy source for the electrolytic production of hydrogen. The present industrial uses for hydrogen are examined to determine if hydrogen produced in this fashion would be competitive with the industry's onsite production or existing hydrogen prices. The paper presents a technical and economic feasibility analysis of the various components required and of the operation of the system as a whole including production, transmission, storage, and markets.

  16. Some practical aspects of peak kilovoltage measurements

    International Nuclear Information System (INIS)

    Irfan, A.Y.; Pugh, V.I.; Jeffery, C.D.

    1985-01-01

    The peak kilovoltage (kVsub(p)) across the X-ray tube electrodes in diagnostic X-ray machines is a most important parameter, affecting both radiation output and beam quality. Four commercially available non-invasive devices used for kVsub(p) measurement were tested using a selection of generator waveforms. The majority of the devices provided satisfactory measurements of the kVsub(p) to within approximately +- kV provided certain operating conditions are observed. (U.K.)

  17. METing SUSY on the Z peak

    Energy Technology Data Exchange (ETDEWEB)

    Barenboim, G.; Bernabeu, J.; Vives, O. [Universitat de Valencia, Departament de Fisica Teorica, Burjassot (Spain); Universitat de Valencia-CSIC, Parc Cientific U.V., IFIC, Paterna (Spain); Mitsou, V.A.; Romero, E. [Universitat de Valencia-CSIC, Parc Cientific U.V., IFIC, Paterna (Spain)

    2016-02-15

    Recently the ATLAS experiment announced a 3 σ excess at the Z-peak consisting of 29 pairs of leptons together with two or more jets, E{sub T}{sup miss} > 225 GeV and HT > 600 GeV, to be compared with 10.6 ± 3.2 expected lepton pairs in the Standard Model. No excess outside the Z-peak was observed. By trying to explain this signal with SUSY we find that only relatively light gluinos, m{sub g} or similar 400 GeV decaying predominantly to Z-boson plus a light gravitino, such that nearly every gluino produces at least one Z-boson in its decay chain, could reproduce the excess. We construct an explicit general gauge mediation model able to reproduce the observed signal overcoming all the experimental limits. Needless to say, more sophisticated models could also reproduce the signal, however, any model would have to exhibit the following features: light gluinos, or heavy particles with a strong production cross section, producing at least one Z-boson in its decay chain. The implications of our findings for the Run II at LHC with the scaling on the Z peak, as well as for the direct search of gluinos and other SUSY particles, are pointed out. (orig.)

  18. Acquisition of peak responding: what is learned?

    Science.gov (United States)

    Balci, Fuat; Gallistel, Charles R; Allen, Brian D; Frank, Krystal M; Gibson, Jacqueline M; Brunner, Daniela

    2009-01-01

    We investigated how the common measures of timing performance behaved in the course of training on the peak procedure in C3H mice. Following fixed interval (FI) pre-training, mice received 16 days of training in the peak procedure. The peak time and spread were derived from the average response rates while the start and stop times and their relative variability were derived from a single-trial analysis. Temporal precision (response spread) appeared to improve in the course of training. This apparent improvement in precision was, however, an averaging artifact; it was mediated by the staggered appearance of timed stops, rather than by the delayed occurrence of start times. Trial-by-trial analysis of the stop times for individual subjects revealed that stops appeared abruptly after three to five sessions and their timing did not change as training was prolonged. Start times and the precision of start and stop times were generally stable throughout training. Our results show that subjects do not gradually learn to time their start or stop of responding. Instead, they learn the duration of the FI, with robust temporal control over the start of the response; the control over the stop of response appears abruptly later.

  19. METing SUSY on the Z peak

    International Nuclear Information System (INIS)

    Barenboim, G.; Bernabeu, J.; Vives, O.; Mitsou, V.A.; Romero, E.

    2016-01-01

    Recently the ATLAS experiment announced a 3 σ excess at the Z-peak consisting of 29 pairs of leptons together with two or more jets, E T miss > 225 GeV and HT > 600 GeV, to be compared with 10.6 ± 3.2 expected lepton pairs in the Standard Model. No excess outside the Z-peak was observed. By trying to explain this signal with SUSY we find that only relatively light gluinos, m g or similar 400 GeV decaying predominantly to Z-boson plus a light gravitino, such that nearly every gluino produces at least one Z-boson in its decay chain, could reproduce the excess. We construct an explicit general gauge mediation model able to reproduce the observed signal overcoming all the experimental limits. Needless to say, more sophisticated models could also reproduce the signal, however, any model would have to exhibit the following features: light gluinos, or heavy particles with a strong production cross section, producing at least one Z-boson in its decay chain. The implications of our findings for the Run II at LHC with the scaling on the Z peak, as well as for the direct search of gluinos and other SUSY particles, are pointed out. (orig.)

  20. Monitoring device for local power peaking coefficients

    International Nuclear Information System (INIS)

    Mihashi, Ishi

    1987-01-01

    Purpose: To determine and monitor the local power peaking coefficients by a method not depending on the combination of fuel types. Constitution: Representative values for the local power distribution can be obtained by determining corresponding burn-up degrees based on the burn-up degree of each of fuel assembly segments obtained in a power distribution monitor and by the interpolation and extrapolation of void coefficients. The typical values are multiplied with compensation coefficients for the control rod effect and coefficients for compensating the effect of adjacent fuel assemblies in a calculation device to obtain typical values for the present local power distribution compensated with all of the effects. Further, the calculation device compares them with typical values of the present local power distribution to obtain an aimed local power peaking coefficient as the maximum value thereof. According to the present invention, since the local power peaking coefficients can be determined not depending on the combination of the kind of fuels, if the combination of fuel assemblies is increased upon fuel change, the amount of operation therefor is not increased. (Kamimura, M.)

  1. Secondary ozone peaks in the troposphere over the Himalayas

    Directory of Open Access Journals (Sweden)

    N. Ojha

    2017-06-01

    Full Text Available Layers with strongly enhanced ozone concentrations in the middle–upper troposphere, referred to as secondary ozone peaks (SOPs, have been observed in different regions of the world. Here we use the global ECHAM5/MESSy atmospheric chemistry model (EMAC to (i investigate the processes causing SOPs, (ii explore both their frequency of occurrence and seasonality, and (iii assess their effects on the tropospheric ozone budget over the Himalayas. The vertical profiles of potential vorticity (PV and a stratospheric ozone tracer (O3s in EMAC simulations, in conjunction with the structure of SOPs, suggest that SOPs over the Himalayas are formed by stratosphere-to-troposphere transport (STT of ozone. The spatial distribution of O3s further shows that such effects are in general most pronounced in the northern part of India. Model simulated ozone distributions and backward air trajectories show that ozone rich air masses, associated with STT, originate as far as northern Africa and the North Atlantic Ocean, the Middle East, as well as in nearby regions in Afghanistan and Pakistan, and are rapidly (within 2–3 days transported to the Himalayas. Analysis of a 15-year (2000–2014 EMAC simulation shows that the frequency of SOPs is highest during the pre-monsoon season (e.g. 11 % of the time in May, while no intense SOP events are found during the July–October period. The SOPs are estimated to enhance the tropospheric column ozone (TCO over the central Himalayas by up to 21 %.

  2. Seasonal Patterns of Gastrointestinal Illness and Streamflow along the Ohio River

    Directory of Open Access Journals (Sweden)

    Elena N. Naumova

    2012-05-01

    Full Text Available Waterborne gastrointestinal (GI illnesses demonstrate seasonal increases associated with water quality and meteorological characteristics. However, few studies have been conducted on the association of hydrological parameters, such as streamflow, and seasonality of GI illnesses. Streamflow is correlated with biological contamination and can be used as proxy for drinking water contamination. We compare seasonal patterns of GI illnesses in the elderly (65 years and older along the Ohio River for a 14-year period (1991–2004 to seasonal patterns of streamflow. Focusing on six counties in close proximity to the river, we compiled weekly time series of hospitalizations for GI illnesses and streamflow data. Seasonal patterns were explored using Poisson annual harmonic regression with and without adjustment for streamflow. GI illnesses demonstrated significant seasonal patterns with peak timing preceding peak timing of streamflow for all six counties. Seasonal patterns of illness remain consistent after adjusting for streamflow. This study found that the time of peak GI illness precedes the peak of streamflow, suggesting either an indirect relationship or a more direct path whereby pathogens enter water supplies prior to the peak in streamflow. Such findings call for interdisciplinary research to better understand associations among streamflow, pathogen loading, and rates of gastrointestinal illnesses.

  3. Chinese emissions peak: Not when, but how

    International Nuclear Information System (INIS)

    Spencer, Thomas; Colombier, Michel; Wang, Xin; Sartor, Oliver; Waisman, Henri

    2016-07-01

    It seems highly likely that China will overachieve its 2020 and 2030 targets, and peak its emissions before 2030 and possibly at a lower level than often assumed. This paper argues that the debate on the timing of the peak is misplaced: what matters is not when by why. For the peak to be seen as a harbinger of deep transformation, it needs to be based on significant macro-economic reform and restructuring, with attendant improvement in energy intensity. The Chinese economic model has been extraordinarily investment and resource intensive, and has driven the growth in GHG emissions. That model is no longer economically or environmentally sustainable. Therefore Chinese policy-makers are faced with a trade-off between slower short-term growth and economic reform, versus supporting short-term growth but slowing economic reform. The outcome will be crucial for the transition to a low-carbon economy. Overall, the 13. FYP (2016-2020) gives the impression of a cautious reflection of the new normal paradigm on the economic front, and a somewhat conservative translation of this shift into the energy and climate targets. Nonetheless, the 13. FYP targets set China well on the way to overachieving its 2020 pledge undertaken at COP15 in Copenhagen, and to potentially overachieving its INDC. It thus seems likely that China will achieve its emissions peak before 2030. However, the crucial question is not when China peaks, but whether the underlying transformation of the Chinese economy and energy system lays the basis for deep decarbonization thereafter. Thorough assessments of the implications of the 'new normal' for Chinese emissions and energy system trajectories, taking into account the link with the Chinese macro-economy, are needed. Scenarios provide a useful framework and should focus on a number of short-term uncertainties. Most energy system and emissions scenarios published today assume a continuity of trends between 2010-2015 and 2015-2020, which is at odds with clear

  4. Reducing the threat of wildlife-vehicle collisions during peak tourism periods using a Roadside Animal Detection System.

    Science.gov (United States)

    Grace, Molly K; Smith, Daniel J; Noss, Reed F

    2017-12-01

    Roadside Animal Detection Systems (RADS) aim to reduce the frequency of wildlife-vehicle collisions. Unlike fencing and wildlife passages, RADS do not attempt to keep animals off the road; rather, they attempt to modify driver behavior by detecting animals near the road and warning drivers with flashing signs. A RADS was installed in Big Cypress National Park (Florida, USA) in 2012 in response to an increased number of Florida panther mortalities. To assess driver response, we measured the speed of individual cars on the road when the RADS was active (flashing) and inactive (not flashing) during the tourist season (November-March) and the off-season (April-October), which vary dramatically in traffic volume. We also used track beds and camera traps to assess whether roadside activity of large mammal species varied between seasons. In the tourist season, the activation of the RADS caused a significant reduction in vehicle speed. However, this effect was not observed in the off-season. Track and camera data showed that the tourist season coincided with peak periods of activity for several large mammals of conservation interest. Drivers in the tourist season generally drove faster than those in the off-season, so a reduction in speed in response to the RADS is more beneficial in the tourist season. Because traffic volume and roadside activity of several species of conservation interest both peak during the tourist season, our study indicates that the RADS has the potential to reduce the number of accidents during this period of heightened risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Seasonal Influenza: An Overview

    Science.gov (United States)

    Li, Christina; Freedman, Marian

    2009-01-01

    Seasonal influenza is a major cause of morbidity and mortality in the United States. It also has major social and economic consequences in the form of high rates of absenteeism from school and work as well as significant treatment and hospitalization costs. In fact, annual influenza epidemics and the resulting deaths and lost days of productivity…

  6. Seasonal atmospheric extinction

    International Nuclear Information System (INIS)

    Mikhail, J.S.

    1979-01-01

    Mean monochromatic extinction coefficients at various wavelengths at the Kottamia Observatory site have shown the existence of a seasonal variation of atmospheric extinction. The extinction of aerosol compontnts with wavelengths at winter represent exceedingly good conditions. Spring gives the highest extinction due to aerosol. (orig.)

  7. Seasonality of Rural Finance

    OpenAIRE

    Khandker, Shahidur R.; Samad, Hussain A.; Badruddoza, Syed

    2017-01-01

    Simultaneity of borrowing, withdrawal of savings, and loan defaults due to the pronounced seasonality of agriculture often leads to investment failure of rural financial institutions. Lack of borrowing leads to lack of in-come- and consumption-smoothing, and in turn, causes inefficient resource allocation by rural households. Financial institutions that are active in rural areas take diffe...

  8. The Hungry Season

    African Journals Online (AJOL)

    start to go some way towards addressing this fundamental question. A delightful animation of The Hungry Season, commissioned by Leonie Joubert and funded by the University of Cape Town's Criminology. Department and the Embassy of Finland, is available online at http://www.youtube.com/ watch?v=iX77NZttLKo.

  9. Antiviral Drugs: Seasonal Flu

    Centers for Disease Control (CDC) Podcasts

    2010-09-29

    In this podcast, Dr. Joe Bresee explains the nature of antiviral drugs and how they are used for seasonal flu.  Created: 9/29/2010 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 9/29/2010.

  10. Warning Signs: Seasonal Flu

    Centers for Disease Control (CDC) Podcasts

    2010-09-29

    In this podcast, Dr. Joe Bresee describes the main symptoms of seasonal flu and when it is serious enough to seek medical help.  Created: 9/29/2010 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 9/29/2010.

  11. Take Three: Seasonal Flu

    Centers for Disease Control (CDC) Podcasts

    2010-09-29

    In this podcast, Dr. Joe Bresee describes how to keep from getting seasonal flu and spreading it to others by taking these three steps.  Created: 9/29/2010 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 9/29/2010.

  12. Aspects of Seasonal and Long-term Trends in Fisheries and ...

    African Journals Online (AJOL)

    ... Schilbe moebiusii and Hydrocynus tanzaniae. A distinct seasonal pattern in fish catches was found, where more fish were landed in the dry months (June, July, August and September) and less during peak of the rainy season (March to May). Reduction of fishing effort, crop farming and inaccessibility of fish landing sites ...

  13. Extended duration of parturition season in North American elk (Cervus elaphus)

    Science.gov (United States)

    Barbara J. Keller; Amy D. Bleisch; Joshua J. Millspaugh; Chad P. Lehman; Jackie J. Kragel; Lonnie P. Hansen; Jason Sumners; Mark A. Rumble; Gary C. Brundige

    2015-01-01

    The timing of births in ungulates has significant implications for juvenile survival and population growth. For North American elk (Cervus elaphus), typical parturition season ranges from late May to early Jun., and juveniles born outside of this peak characteristically exhibit lowered survival. We observed abnormally long parturition seasons in free-ranging elk...

  14. The timing of birds' breeding seasons : the Perrins hypothesis revisited especially for migrants

    NARCIS (Netherlands)

    Drent, Rudolf H.

    2006-01-01

    Perrins (1970) galvanized thinking on the timing of birds' breeding seasons by pointing out that most individuals laid too late for the offspring to profit fully from the seasonal peak of food abundance, and suggested that the proximate cause was a shortage of food for the female when forming the

  15. Between Two Worlds: Twin Peaks and the Film/Television Divide

    Directory of Open Access Journals (Sweden)

    Siobhan Lyons

    2017-04-01

    Full Text Available In 1992, the year David Lynch’s cult television series 'Twin Peaks' was pulled off air, Lynch released the film 'Twin Peaks: Fire Walk with Me', a prequel to the television series which filled in some of the gaps left from the series finale cliff-hanger. The film was received with unanimously negative reviews from critics and fans alike, condemning both its subtle and obvious deviations from the series and its inclusion of the character Laura Palmer, whose absence was a crucial narrative device at the centre of 'Twin Peaks'. In film form, the 'Twin Peaks' narrative suffers from thematic inconsistencies and aesthetic deviations. The scope of 'Twin Peaks' seems much more capable in the setting of television and its gradual, episodic set-up. In recent years, however, with the announcement of a revival of the series, retrospective analysis of 'Fire Walk with Me' has become more positive, and the film has also become an integral part of the overall 'Twin Peaks' canon. Nevertheless, the transition from television to film in the case of 'Twin Peaks' has remained a point of fan and scholarly controversy, with issues of continuity, narrative and aesthetics between the two different mediums continually being addressed and compared. In light of the news that the new season of 'Twin Peaks' is set to be released in 2017, this article examines the significance of 'Fire Walk with Me' as a cinematic counterpart and prequel to the original series, and how this has helped shape – whether positively or not – the overall narrative of 'Twin Peaks'.

  16. Inverse photon-photon processes

    International Nuclear Information System (INIS)

    Carimalo, C.; Crozon, M.; Kesler, P.; Parisi, J.

    1981-12-01

    We here consider inverse photon-photon processes, i.e. AB → γγX (where A, B are hadrons, in particular protons or antiprotons), at high energies. As regards the production of a γγ continuum, we show that, under specific conditions the study of such processes might provide some information on the subprocess gg γγ, involving a quark box. It is also suggested to use those processes in order to systematically look for heavy C = + structures (quarkonium states, gluonia, etc.) showing up in the γγ channel. Inverse photon-photon processes might thus become a new and fertile area of investigation in high-energy physics, provided the difficult problem of discriminating between direct photons and indirect ones can be handled in a satisfactory way

  17. Analysis of RAE-1 inversion

    Science.gov (United States)

    Hedland, D. A.; Degonia, P. K.

    1974-01-01

    The RAE-1 spacecraft inversion performed October 31, 1972 is described based upon the in-orbit dynamical data in conjunction with results obtained from previously developed computer simulation models. The computer simulations used are predictive of the satellite dynamics, including boom flexing, and are applicable during boom deployment and retraction, inter-phase coast periods, and post-deployment operations. Attitude data, as well as boom tip data, were analyzed in order to obtain a detailed description of the dynamical behavior of the spacecraft during and after the inversion. Runs were made using the computer model and the results were analyzed and compared with the real time data. Close agreement between the actual recorded spacecraft attitude and the computer simulation results was obtained.

  18. Seasonality of fire weather strongly influences fire regimes in South Florida savanna-grassland landscapes.

    Directory of Open Access Journals (Sweden)

    William J Platt

    Full Text Available Fire seasonality, an important characteristic of fire regimes, commonly is delineated using seasons based on single weather variables (rainfall or temperature. We used nonparametric cluster analyses of a 17-year (1993-2009 data set of weather variables that influence likelihoods and spread of fires (relative humidity, air temperature, solar radiation, wind speed, soil moisture to explore seasonality of fire in pine savanna-grassland landscapes at the Avon Park Air Force Range in southern Florida. A four-variable, three-season model explained more variation within fire weather variables than models with more seasons. The three-season model also delineated intra-annual timing of fire more accurately than a conventional rainfall-based two-season model. Two seasons coincided roughly with dry and wet seasons based on rainfall. The third season, which we labeled the fire season, occurred between dry and wet seasons and was characterized by fire-promoting conditions present annually: drought, intense solar radiation, low humidity, and warm air temperatures. Fine fuels consisting of variable combinations of pyrogenic pine needles, abundant C4 grasses, and flammable shrubs, coupled with low soil moisture, and lightning ignitions early in the fire season facilitate natural landscape-scale wildfires that burn uplands and across wetlands. We related our three season model to fires with different ignition sources (lightning, military missions, and prescribed fires over a 13-year period with fire records (1997-2009. Largest wildfires originate from lightning and military ignitions that occur within the early fire season substantially prior to the peak of lightning strikes in the wet season. Prescribed ignitions, in contrast, largely occur outside the fire season. Our delineation of a pronounced fire season provides insight into the extent to which different human-derived fire regimes mimic lightning fire regimes. Delineation of a fire season associated with

  19. Seasonality of Fire Weather Strongly Influences Fire Regimes in South Florida Savanna-Grassland Landscapes

    Science.gov (United States)

    Platt, William J.; Orzell, Steve L.; Slocum, Matthew G.

    2015-01-01

    Fire seasonality, an important characteristic of fire regimes, commonly is delineated using seasons based on single weather variables (rainfall or temperature). We used nonparametric cluster analyses of a 17-year (1993–2009) data set of weather variables that influence likelihoods and spread of fires (relative humidity, air temperature, solar radiation, wind speed, soil moisture) to explore seasonality of fire in pine savanna-grassland landscapes at the Avon Park Air Force Range in southern Florida. A four-variable, three-season model explained more variation within fire weather variables than models with more seasons. The three-season model also delineated intra-annual timing of fire more accurately than a conventional rainfall-based two-season model. Two seasons coincided roughly with dry and wet seasons based on rainfall. The third season, which we labeled the fire season, occurred between dry and wet seasons and was characterized by fire-promoting conditions present annually: drought, intense solar radiation, low humidity, and warm air temperatures. Fine fuels consisting of variable combinations of pyrogenic pine needles, abundant C4 grasses, and flammable shrubs, coupled with low soil moisture, and lightning ignitions early in the fire season facilitate natural landscape-scale wildfires that burn uplands and across wetlands. We related our three season model to fires with different ignition sources (lightning, military missions, and prescribed fires) over a 13-year period with fire records (1997–2009). Largest wildfires originate from lightning and military ignitions that occur within the early fire season substantially prior to the peak of lightning strikes in the wet season. Prescribed ignitions, in contrast, largely occur outside the fire season. Our delineation of a pronounced fire season provides insight into the extent to which different human-derived fire regimes mimic lightning fire regimes. Delineation of a fire season associated with timing of

  20. Inverse problem in nuclear physics

    International Nuclear Information System (INIS)

    Zakhariev, B.N.

    1976-01-01

    The method of reconstruction of interaction from the scattering data is formulated in the frame of the R-matrix theory in which the potential is determined by position of resonance Esub(lambda) and their reduced widths γ 2 lambda. In finite difference approximation for the Schroedinger equation this new approach allows to make the logics of the inverse problem IP more clear. A possibility of applications of IP formalism to various nuclear systems is discussed. (author)

  1. An Inverse Free-Electron-Laser accelerator

    International Nuclear Information System (INIS)

    Fisher, A.S.; Gallardo, J.C.; van Steenbergen, A.; Ulc, S.; Woodle, M.; Sandweiss, J.; Fang, Jyan-Min

    1993-01-01

    Recent work at BNL on electron acceleration using the Inverse Free-Electron Laser (IFEL) has considered a low-energy, high-gradient, multi-stage linear accelerator. Experiments are planned at BNL's Accelerator Test Facility using its 50-MeV linac and 100-GW CO 2 laser. We have built and tested a fast-excitation wiggler magnet with constant field, tapered period, and overall length of 47 cm. Vanadium-Permendur ferromagnetic laminations are stacked in alternation with copper, eddy-current-induced, field reflectors to achieve a 1.4-T peak field with a 4-mm gap and a typical period of 3 cm. The laser beam will pass through the wiggler in a low-loss, dielectric-coated stainless-steel, rectangular waveguide. The attenuation and transverse mode has been measured in waveguide sections of various lengths, with and without the dielectric. Results of 1-D and 3-D IFEL simulations, including wiggler errors, will be presented for several cases: the initial, single-module experiment with ΔE = 39 MeV, a four-module design giving ΔE = 100 MeV in a total length of 2 m, and an eight-module IFEL with ΔE = 210 MeV

  2. The LLNL/UCLA high gradient inverse free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Moody, J. T.; Musumeci, P.; Anderson, G.; Anderson, S.; Betts, S.; Fisher, S.; Gibson, D.; Tremaine, A.; Wu, S. [Department of Physics and Astronomy, UCLA, Los Angeles California, 90095 (United States); Lawrence Livermore National Laboratory (United States)

    2012-12-21

    We describe the Inverse Free Electron Accelerator currently under construction at Lawrence Livermore National Lab. Upon completion of this accelerator, high brightness electrons generated in the photoinjector blowout regime and accelerated to 50 MeV by S-band accelerating sections will interact with > 4 TW peak power Ti:Sapphire laser in a highly tapered 50 cm undulator and experience an acceleration gradient of > 200 MeV/m. We present the final design of the accelerator as well as the results of start-to-end simulations investigating preservation of beam quality and tolerances involved with this accelerator.

  3. Improving estimates of N2O emissions for western and central Europe using a Bayesian inversion approach

    Science.gov (United States)

    Thompson, R. L.; Gerbig, C.; Roedenbeck, C.; Heimann, M.

    2009-04-01

    The nitrous oxide (N2O) mixing ratio has been increasing in the atmosphere since the industrial revolution, from 270 ppb in 1750 to 320 ppb in 2007 with a steady growth rate of around 0.26% since the early 1980's. The increase in N2O is worrisome for two main reasons. First, it is a greenhouse gas; this means that its atmospheric increase translates to an enhancement in radiative forcing of 0.16 ± 0.02 Wm-2 making it currently the fourth most important long-lived greenhouse gas and is predicted to soon overtake CFC's to become the third most important. Second, it plays an important role in stratospheric ozone chemistry. Human activities are the primary cause of the atmospheric N2O increase. The largest anthropogenic source of N2O is from the use of N-fertilizers in agriculture but fossil fuel combustion and industrial processes, such as adipic and nitric acid production, are also important. We present a Bayesian inversion approach for estimating N2O fluxes over central and western Europe using high frequency in-situ concentration data from the Ochsenkopf tall tower (50 °01′N, 11 °48′, 1022 masl). For the inversion, we employ a Lagrangian-type transport model, STILT, which provides source-receptor relationships at 10 km using ECMWF meteorological data. The a priori flux estimates used were from IER, for anthropogenic, and GEIA, for natural fluxes. N2O fluxes were retrieved monthly at 2 x 2 degree spatial resolution for 2007. The retrieved N2O fluxes showed significantly more spatial heterogeneity than in the a priori field and considerable seasonal variability. The timing of peak emissions was different for different regions but in general the months with the strongest emissions were May and August. Overall, the retrieved flux (anthropogenic and natural) was lower than in the a priori field.

  4. Elastic reflection waveform inversion with variable density

    KAUST Repository

    Li, Yuanyuan; Li, Zhenchun; Alkhalifah, Tariq Ali; Guo, Qiang

    2017-01-01

    Elastic full waveform inversion (FWI) provides a better description of the subsurface than those given by the acoustic assumption. However it suffers from a more serious cycle skipping problem compared with the latter. Reflection waveform inversion

  5. Use of an iterative convolution approach for qualitative and quantitative peak analysis in low resolution gamma-ray spectra

    International Nuclear Information System (INIS)

    Gardner, Robin P.; Ai Xianyun; Peeples, Cody R.; Wang, Jiaxin; Lee, Kyoung; Peeples, Johanna L.; Calderon, Adan

    2011-01-01

    In many applications, low resolution gamma-ray spectrometers, such as sodium iodide scintillation detectors, are widely used primarily due to their relatively low cost and high detection efficiency. There is widespread interest in improved methods for analyzing spectral data acquired with such devices, using inverse analysis. Peak means and peak areas in gamma- and X-ray spectra are needed for both qualitative and quantitative analysis. This paper introduces the PEAKSI code package that was developed at the Center for Engineering Applications of Radioisotopes (CEAR). The basic approach described here is to use accurate forward models and iterative convolution instead of direct deconvolution. Rather than smoothing and differentiation a combination of linear regression and non-linear searching is used to minimize the reduced chi-square, since this approach retains the capability of establishing uncertainties in the estimated peak parameters. The PEAKSI package uses a Levenberg-Marquardt (LM) non-linear search method combined with multiple linear regression (MLR) to minimize the reduced chi-square value for fitting single or multiple overlapping peaks to determine peak parameters, including peak means, peak standard deviations or full width at half maximum (FWHM), net peak counts, and background counts of peaks in experimental gamma-ray spectra. This approach maintains the natural error structure so that parameter uncertainties can be estimated. The plan is to release this code to the public in the near future.

  6. Particle creation by peak electric field

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, T.C. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Gavrilov, S.P. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Herzen State Pedagogical University of Russia, Department of General and Experimental Physics, St. Petersburg (Russian Federation); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); P. N. Lebedev Physical Institute, Moscow (Russian Federation); University of Sao Paulo, Institute of Physics, CP 66318, Sao Paulo, SP (Brazil)

    2016-08-15

    The particle creation by the so-called peak electric field is considered. The latter field is a combination of two exponential parts, one exponentially increasing and another exponentially decreasing. We find exact solutions of the Dirac equation with the field under consideration with appropriate asymptotic conditions and calculate all the characteristics of particle creation effect, in particular, differential mean numbers of created particle, total number of created particles, and the probability for a vacuum to remain a vacuum. Characteristic asymptotic regimes are discussed in detail and a comparison with the pure asymptotically decaying field is considered. (orig.)

  7. Octant vectorcardiography - the evaluation by peaks.

    Science.gov (United States)

    Laufberger, V

    1982-01-01

    From the Frank lead potentials a computer prints out an elementary table. Therein, the electrical space of left ventricle depolarization is divided into eight spatial parts labelled by numbers 1-8 and called octants. Within these octants six peaks are determined labelled with letters ALPR-IS. Their localization is described by six-digit topograms characteristic for each patient. From 300 cases of patients after myocardial infarction, three data bases were compiled enabling every case to be classified into classes, subclasses and types. The follow up of patients according to these principles gives an objective and detailed image about the progress of coronary artery disease.

  8. Energy peaks: A high energy physics outlook

    Science.gov (United States)

    Franceschini, Roberto

    2017-12-01

    Energy distributions of decay products carry information on the kinematics of the decay in ways that are at the same time straightforward and quite hidden. I will review these properties and discuss their early historical applications, as well as more recent ones in the context of (i) methods for the measurement of masses of new physics particle with semi-invisible decays, (ii) the characterization of Dark Matter particles produced at colliders, (iii) precision mass measurements of Standard Model particles, in particular of the top quark. Finally, I will give an outlook of further developments and applications of energy peak method for high energy physics at colliders and beyond.

  9. Method and apparatus for current-output peak detection

    Science.gov (United States)

    De Geronimo, Gianluigi

    2017-01-24

    A method and apparatus for a current-output peak detector. A current-output peak detector circuit is disclosed and works in two phases. The peak detector circuit includes switches to switch the peak detector circuit from the first phase to the second phase upon detection of the peak voltage of an input voltage signal. The peak detector generates a current output with a high degree of accuracy in the second phase.

  10. Incorporating modelled subglacial hydrology into inversions for basal drag

    Directory of Open Access Journals (Sweden)

    C. P. Koziol

    2017-12-01

    Full Text Available A key challenge in modelling coupled ice-flow–subglacial hydrology is initializing the state and parameters of the system. We address this problem by presenting a workflow for initializing these values at the start of a summer melt season. The workflow depends on running a subglacial hydrology model for the winter season, when the system is not forced by meltwater inputs, and ice velocities can be assumed constant. Key parameters of the winter run of the subglacial hydrology model are determined from an initial inversion for basal drag using a linear sliding law. The state of the subglacial hydrology model at the end of winter is incorporated into an inversion of basal drag using a non-linear sliding law which is a function of water pressure. We demonstrate this procedure in the Russell Glacier area and compare the output of the linear sliding law with two non-linear sliding laws. Additionally, we compare the modelled winter hydrological state to radar observations and find that it is in line with summer rather than winter observations.

  11. On a complete topological inverse polycyclic monoid

    Directory of Open Access Journals (Sweden)

    S. O. Bardyla

    2016-12-01

    Full Text Available We give sufficient conditions when a topological inverse $\\lambda$-polycyclic monoid $P_{\\lambda}$ is absolutely $H$-closed in the class of topological inverse semigroups. For every infinite cardinal $\\lambda$ we construct the coarsest semigroup inverse topology $\\tau_{mi}$ on $P_\\lambda$ and give an example of a topological inverse monoid $S$ which contains the polycyclic monoid $P_2$ as a dense discrete subsemigroup.

  12. Temperature dependence of mobility in silicon (100) inversion layers at low temperatures

    International Nuclear Information System (INIS)

    Kawaguchi, Y.; Suzuki, T.; Kawaji, S.

    1982-01-01

    Electron mobility of Si(100) n-inversion layers in MOSFETs having μsub(peak) (4.2 K) = 4000.6500 and 12000 cm 2 /V x s has been measured at temperatures between 1 and 80 K. The carrier concentration dependence of the mobility extrapolated to T = O and the temperature dependent part of the scattering probability are investigated. (orig.)

  13. Inversion: A Most Useful Kind of Transformation.

    Science.gov (United States)

    Dubrovsky, Vladimir

    1992-01-01

    The transformation assigning to every point its inverse with respect to a circle with given radius and center is called an inversion. Discusses inversion with respect to points, circles, angles, distances, space, and the parallel postulate. Exercises related to these topics are included. (MDH)

  14. Probabilistic Geoacoustic Inversion in Complex Environments

    Science.gov (United States)

    2015-09-30

    Probabilistic Geoacoustic Inversion in Complex Environments Jan Dettmer School of Earth and Ocean Sciences, University of Victoria, Victoria BC...long-range inversion methods can fail to provide sufficient resolution. For proper quantitative examination of variability, parameter uncertainty must...project aims to advance probabilistic geoacoustic inversion methods for complex ocean environments for a range of geoacoustic data types. The work is

  15. Computation of peak discharge at culverts

    Science.gov (United States)

    Carter, Rolland William

    1957-01-01

    Methods for computing peak flood flow through culverts on the basis of a field survey of highwater marks and culvert geometry are presented. These methods are derived from investigations of culvert flow as reported in the literature and on extensive laboratory studies of culvert flow. For convenience in computation, culvert flow has been classified into six types, according to the location of the control section and the relative heights of the head-water and tail-water levels. The type of flow which occurred at any site can be determined from the field data and the criteria given in this report. A discharge equation has been developed for each flow type by combining the energy and continuity equations for the distance between an approach section upstream from the culvert and a terminal section within the culvert barrel. The discharge coefficient applicable to each flow type is listed for the more common entrance geometries. Procedures for computing peak discharge through culverts are outlined in detail for each of the six flow types.

  16. Comparison of five portable peak flow meters.

    Science.gov (United States)

    Takara, Glaucia Nency; Ruas, Gualberto; Pessoa, Bruna Varanda; Jamami, Luciana Kawakami; Di Lorenzo, Valéria Amorim Pires; Jamami, Mauricio

    2010-05-01

    To compare the measurements of spirometric peak expiratory flow (PEF) from five different PEF meters and to determine if their values are in agreement. Inaccurate equipment may result in incorrect diagnoses of asthma and inappropriate treatments. Sixty-eight healthy, sedentary and insufficiently active subjects, aged from 19 to 40 years, performed PEF measurements using Air Zone, Assess, Galemed, Personal Best and Vitalograph peak flow meters. The highest value recorded for each subject for each device was compared to the corresponding spirometric values using Friedman's test with Dunn's post-hoc (pmeters were 428 (263-688 L/min), 450 (350-800 L/min), 420 (310-720 L/min), 380 (300-735 L/min), 400 (310-685 L/min) and 415 (335-610 L/min), respectively. Significant differences were found when the spirometric values were compared to those recorded by the Air Zone(R) (pmeters. There was no agreement between the spirometric values and the five PEF meters. The results suggest that the values recorded from Galemed meters may underestimate the actual value, which could lead to unnecessary interventions, and that Air Zone meters overestimate spirometric values, which could obfuscate the need for intervention. These findings must be taken into account when interpreting both devices' results in younger people. These differences should also be considered when directly comparing values from different types of PEF meters.

  17. Monitoring device for local power peaking coefficient

    International Nuclear Information System (INIS)

    Mitsuhashi, Ishi

    1987-01-01

    Purpose: To monitor the local power peaking coefficients obtained by the method not depending on the combination of fuel types. Method: A plurality of representative values for the local power distribution determined by the nuclear constant calculation for one fuel assembly are memorized regarding each of the burn-up degree and the void coefficient on every positions and fuel types in fuel rod assemblies. While on the other hand, the representative values for the local power distribution as described above are compensated by a compensation coefficient considering the effect of adjacent segments and a control rod compensation coefficient considering the effect due to the control rod insertion relative to the just-mentioned compensation coefficient. Then, the maximum value among them is selected to determine the local power peaking coefficient at each of the times and each of the segments, which is monitored. According to this system, the calculation and the working required for the fitting work depending on the combination of fuel types are no more required at all to facilitate the maintenance as well. (Horiuchi, T.)

  18. Seasonal variation in diurnal atmospheric grass pollen concentration profiles

    DEFF Research Database (Denmark)

    Peel, Robert George; Ørby, Pia Viuf; Skjøth, Carsten Ambelas

    2014-01-01

    the time of day when peak concentrations are most likely to occur using seasonally averaged diurnal profiles. Atmospheric pollen loads are highly dependent upon emissions, and different species of grass are known to flower and emit pollen at different times of the day and during different periods......In this study, the diurnal atmospheric grass pollen concentration profile within the Danish city of Aarhus was shown to change in a systematic manner as the pollen season progressed. Although diurnal grass pollen profiles can differ greatly from day-to-day, it is common practice to establish...... of the pollen season. Pollen concentrations are also influenced by meteorological factors - directly through those parameters that govern pollen dispersion and transport, and indirectly through the weather-driven flowering process. We found that three different profiles dominated the grass pollen season...

  19. Fermi liquid character in the photoemission/inverse photoemission spectra of highly correlated electron systems

    International Nuclear Information System (INIS)

    Riseborough, P.S.

    1990-01-01

    We calculate the photoemission/inverse photoemission spectrum for an N-fold degenerate Hubbard model, in the 1/N approximation. The spectra are broadened, and for sufficiently large Coulomb interaction strengths the spectra show satellites both in the photoemission and the brehmstrahlung isochromat spectroscopy portions of the spectra. The intensity of the spectra at the fermi level are equal to the noninteracting values, in accordance with Luttinger's theorem. We show that this can result in a temperature-dependent peak at the Fermi level; the width of the peak is governed by the quasi-particle lifetime. We relate the temperature dependent peak to the Fermi-liquid properties

  20. Vaccination against seasonal flu

    CERN Multimedia

    2015-01-01

    The Medical Service once again recommends you to get your annual flu vaccination for the year.   Vaccination is the most effective way of avoiding the illness and any serious consequences and protecting those around you. The flu can have especially serious consequences for people with chronic conditions (diabetes, cardio-vascular disease, etc.), pregnant women, infants, and people over 65 years of age. Remember, anyone working on the CERN site who wishes to be vaccinated against seasonal flu should go to the Infirmary (Building 57, ground floor) with their vaccine. The Medical Service will issue a prescription on the day of the vaccination for the purposes of reimbursement by UNIQA. NB: The Medical Service cannot provide this vaccination service for family members or retired members of the personnel. For more information: • The "Seasonal flu" flyer by the Medical Service • Recommendations of the Swiss Federal Office of Public...

  1. Vaccination against seasonal influenza

    CERN Multimedia

    DG Unit

    2009-01-01

    As every year, the Medical Service is taking part in the campaign to promote vaccination against seasonal influenza. Vaccination against seasonal influenza is especially recommended for people suffering from chronic lung, cardio-vascular or kidney conditions or diabetes, for those recovering from a serious illness or surgical operation and for everyone over the age of 65. The influenza virus is transmitted by air and contact with contaminated surfaces, hence the importance of washing hands regularly with soap and / or disinfection using a hydro-alcoholic solution. From the onset of symptoms (fever> 38°, chills, cough, muscle aches and / or joint pain, fatigue) you are strongly recommended to stay at home to avoid spreading the virus. In the present context of the influenza A (H1N1) pandemic, it is important to dissociate these two illnesses and emphasise that the two viruses and the vaccines used to combat them are quite different and that protection against one will not pr...

  2. Sensitivity of peak flow to the change of rainfall temporal pattern due to warmer climate

    Science.gov (United States)

    Fadhel, Sherien; Rico-Ramirez, Miguel Angel; Han, Dawei

    2018-05-01

    The widely used design storms in urban drainage networks has different drawbacks. One of them is that the shape of the rainfall temporal pattern is fixed regardless of climate change. However, previous studies have shown that the temporal pattern may scale with temperature due to climate change, which consequently affects peak flow. Thus, in addition to the scaling of the rainfall volume, the scaling relationship for the rainfall temporal pattern with temperature needs to be investigated by deriving the scaling values for each fraction within storm events, which is lacking in many parts of the world including the UK. Therefore, this study analysed rainfall data from 28 gauges close to the study area with a 15-min resolution as well as the daily temperature data. It was found that, at warmer temperatures, the rainfall temporal pattern becomes less uniform, with more intensive peak rainfall during higher intensive times and weaker rainfall during less intensive times. This is the case for storms with and without seasonal separations. In addition, the scaling values for both the rainfall volume and the rainfall fractions (i.e. each segment of rainfall temporal pattern) for the summer season were found to be higher than the corresponding results for the winter season. Applying the derived scaling values for the temporal pattern of the summer season in a hydrodynamic sewer network model produced high percentage change of peak flow between the current and future climate. This study on the scaling of rainfall fractions is the first in the UK, and its findings are of importance to modellers and designers of sewer systems because it can provide more robust scenarios for flooding mitigation in urban areas.

  3. Summer season | Cafeteria closures

    CERN Multimedia

    2013-01-01

    Please note the following cafeteria closures over the summer season: Bldg. 54 closed from 29/07/2013 to 06/09/2013. Bldg. 13: closed from 13/07/2013 to 06/09/2013. Restaurant No. 2, table service (brasserie and restaurant): closed from 01/08/2013 to 06/09/2013. Bldg. 864: closed from 29/07/2013 to 06/09/2013. Bldg. 865: closed from 29/07/2013 to 06/09/2013.

  4. Direct contamination - seasonality

    International Nuclear Information System (INIS)

    Aarkrog, A.

    1994-01-01

    Direct contamination is the primary pathway to terrestrial vegetation in the first period after an activity release to the atmosphere. All radionuclides are able to be transferred via this pathway. Deposition, interception and retention are the three processes involved in direct contamination of crops. Wet deposition is more important than dry deposition in temperature regions. Resuspension and rainsplash both belong to secondary direct deposition and became evident for e.g. radiocaesium after the Chernobyl accident. Seasonality is the varying response to radioactive contamination of crops according to the time of the year when the contamination occurs. Shortlived radionuclides (as 131 I) and those that mainly enter the foodchain by direct contamination (e.g. 137 Cs) are especially important in this connection. In particular, the contamination of cereal crops is influenced by seasonality. As a result of seasonality the impact of the Chernobyl accident on the radioactive contamination of human diet was for the same deposition density higher in southern than in northern Europe. (orig.)

  5. Vaccination against seasonal influenza

    CERN Multimedia

    GS Department

    2010-01-01

    This year, as usual, the Medical Service is helping to promote vaccination against seasonal influenza. Vaccination against seasonal flu is especially recommended for anyone who suffers from chronic pulmonary, cardio-vascular or kidney disease or diabetes, is recovering from a serious illness or major surgery, or is over 65 years of age. The flu virus is transmitted through the air and through contact with contaminated surfaces, so frequent hand-washing with soap and/or an antiseptic hand wash is of great importance. As soon as the first symptoms appear (fever above 38°, shivering, coughing, muscle and/or joint pains, generalised weakness), you are strongly recommended to stay at home to avoid spreading the virus. Anyone working on the CERN site who wishes to be vaccinated against seasonal flu should go to the Infirmary (Building 57, ground floor), with their dose of vaccine. The Medical Service will issue a prescription on the day of the vaccination for the purposes of reimbursement through UNIQA...

  6. Did medieval trade activity and a viral etiology control the spatial extent and seasonal distribution of Black Death mortality?

    Science.gov (United States)

    Bossak, Brian H; Welford, Mark R

    2009-06-01

    Recent research into the world's greatest recorded epidemic, the Medieval Black Death (MBD), has cast doubt on Bubonic Plague as the etiologic agent. Prior research has recently culminated in outstanding advances in our understanding of the spatio-temporal pattern of MBD mortality, and a characterization of the incubation, latent, infectious, and symptomatic periods of the MBD. However, until now, several mysteries remained unexplained, including perhaps the biggest quandary of all: why did the MBD exhibit inverse seasonal peaks in mortality from diseases recorded in modern times, such as seasonal Influenza or the Indian Plague Epidemics of the early 1900 s? Although some have argued that climate changes likely explain the observed differences between modern clinical Bubonic Plague seasonality and MBD mortality accounts, we believe that another factor explains these dissimilarities. Here, we provide a synthetic hypothesis which builds upon previous theories developed in the last ten years or so. Our all-encompassing theory explains the causation, dissemination, and lethality of the MBD. We theorize that the MBD was a human-to-human transmitted virus, originating in East-Central Asia and not Africa (as some recent work has proposed), and that its areal extent during the first great epidemic wave of 1347-1350 was controlled hierarchically by proximity to trade routes. We also propose that the seasonality of medieval trade controlled the warm-weather mortality peaks witnessed during 1347-1350; during the time of greatest market activity, traders, fairgoers, and religious pilgrims served as unintentional vectors of a lethal virus with an incubation period of approximately 32 days, including a largely asymptomatic yet infectious period of roughly three weeks. We include a description of the rigorous research agenda that we have proposed in order to subject our theory to scientific scrutiny and a description of our plans to generate the first publicly available

  7. Flublok Seasonal Influenza (Flu) Vaccination

    Science.gov (United States)

    ... type="submit" value="Submit" /> Archived Flu Emails Influenza Types Seasonal Avian Swine Variant Pandemic Other Flublok Seasonal Influenza (Flu) Vaccine Questions & Answers Language: English (US) Español ...

  8. Spatial Interpolation of Historical Seasonal Rainfall Indices over Peninsular Malaysia

    Directory of Open Access Journals (Sweden)

    Hassan Zulkarnain

    2018-01-01

    Full Text Available The inconsistency in inter-seasonal rainfall due to climate change will cause a different pattern in the rainfall characteristics and distribution. Peninsular Malaysia is not an exception for this inconsistency, in which it is resulting extreme events such as flood and water scarcity. This study evaluates the seasonal patterns in rainfall indices such as total amount of rainfall, the frequency of wet days, rainfall intensity, extreme frequency, and extreme intensity in Peninsular Malaysia. 40 years (1975-2015 data records have been interpolated using Inverse Distance Weighted method. The results show that the formation of rainfall characteristics are significance during the Northeast monsoon (NEM, as compared to Southwest monsoon (SWM. Also, there is a high rainfall intensity and frequency related to extreme over eastern coasts of Peninsula during the NEM season.

  9. Spatial Interpolation of Historical Seasonal Rainfall Indices over Peninsular Malaysia

    Science.gov (United States)

    Hassan, Zulkarnain; Haidir, Ahmad; Saad, Farah Naemah Mohd; Ayob, Afizah; Rahim, Mustaqqim Abdul; Ghazaly, Zuhayr Md.

    2018-03-01

    The inconsistency in inter-seasonal rainfall due to climate change will cause a different pattern in the rainfall characteristics and distribution. Peninsular Malaysia is not an exception for this inconsistency, in which it is resulting extreme events such as flood and water scarcity. This study evaluates the seasonal patterns in rainfall indices such as total amount of rainfall, the frequency of wet days, rainfall intensity, extreme frequency, and extreme intensity in Peninsular Malaysia. 40 years (1975-2015) data records have been interpolated using Inverse Distance Weighted method. The results show that the formation of rainfall characteristics are significance during the Northeast monsoon (NEM), as compared to Southwest monsoon (SWM). Also, there is a high rainfall intensity and frequency related to extreme over eastern coasts of Peninsula during the NEM season.

  10. Emissions Scenarios and Fossil-fuel Peaking

    Science.gov (United States)

    Brecha, R.

    2008-12-01

    Intergovernmental Panel on Climate Change (IPCC) emissions scenarios are based on detailed energy system models in which demographics, technology and economics are used to generate projections of future world energy consumption, and therefore, of greenhouse gas emissions. Built into the assumptions for these scenarios are estimates for ultimately recoverable resources of various fossil fuels. There is a growing chorus of critics who believe that the true extent of recoverable fossil resources is much smaller than the amounts taken as a baseline for the IPCC scenarios. In a climate optimist camp are those who contend that "peak oil" will lead to a switch to renewable energy sources, while others point out that high prices for oil caused by supply limitations could very well lead to a transition to liquid fuels that actually increase total carbon emissions. We examine a third scenario in which high energy prices, which are correlated with increasing infrastructure, exploration and development costs, conspire to limit the potential for making a switch to coal or natural gas for liquid fuels. In addition, the same increasing costs limit the potential for expansion of tar sand and shale oil recovery. In our qualitative model of the energy system, backed by data from short- and medium-term trends, we have a useful way to gain a sense of potential carbon emission bounds. A bound for 21st century emissions is investigated based on two assumptions: first, that extractable fossil-fuel resources follow the trends assumed by "peak oil" adherents, and second, that little is done in the way of climate mitigation policies. If resources, and perhaps more importantly, extraction rates, of fossil fuels are limited compared to assumptions in the emissions scenarios, a situation can arise in which emissions are supply-driven. However, we show that even in this "peak fossil-fuel" limit, carbon emissions are high enough to surpass 550 ppm or 2°C climate protection guardrails. Some

  11. Temporal and spatial PM10 concentration distribution using an inverse distance weighted method in Klang Valley, Malaysia

    Science.gov (United States)

    Tarmizi, S. N. M.; Asmat, A.; Sumari, S. M.

    2014-02-01

    PM10 is one of the air contaminants that can be harmful to human health. Meteorological factors and changes of monsoon season may affect the distribution of these particles. The objective of this study is to determine the temporal and spatial particulate matter (PM10) concentration distribution in Klang Valley, Malaysia by using the Inverse Distance Weighted (IDW) method at different monsoon season and meteorological conditions. PM10 and meteorological data were obtained from the Malaysian Department of Environment (DOE). Particles distribution data were added to the geographic database on a seasonal basis. Temporal and spatial patterns of PM10 concentration distribution were determined by using ArcGIS 9.3. The higher PM10 concentrations are observed during Southwest monsoon season. The values are lower during the Northeast monsoon season. Different monsoon seasons show different meteorological conditions that effect PM10 distribution.

  12. Temporal and spatial PM10 concentration distribution using an inverse distance weighted method in Klang Valley, Malaysia

    International Nuclear Information System (INIS)

    Tarmizi, S N M; Asmat, A; Sumari, S M

    2014-01-01

    PM 10 is one of the air contaminants that can be harmful to human health. Meteorological factors and changes of monsoon season may affect the distribution of these particles. The objective of this study is to determine the temporal and spatial particulate matter (PM 10 ) concentration distribution in Klang Valley, Malaysia by using the Inverse Distance Weighted (IDW) method at different monsoon season and meteorological conditions. PM 10 and meteorological data were obtained from the Malaysian Department of Environment (DOE). Particles distribution data were added to the geographic database on a seasonal basis. Temporal and spatial patterns of PM 10 concentration distribution were determined by using ArcGIS 9.3. The higher PM 10 concentrations are observed during Southwest monsoon season. The values are lower during the Northeast monsoon season. Different monsoon seasons show different meteorological conditions that effect PM 10 distribution

  13. Inverse Compton gamma-rays from pulsars

    International Nuclear Information System (INIS)

    Morini, M.

    1983-01-01

    A model is proposed for pulsar optical and gamma-ray emission where relativistic electrons beams: (i) scatter the blackbody photons from the polar cap surface giving inverse Compton gamma-rays and (ii) produce synchrotron optical photons in the light cylinder region which are then inverse Compton scattered giving other gamma-rays. The model is applied to the Vela pulsar, explaining the first gamma-ray pulse by inverse Compton scattering of synchrotron photons near the light cylinder and the second gamma-ray pulse partly by inverse Compton scattering of synchrotron photons and partly by inverse Compton scattering of the thermal blackbody photons near the star surface. (author)

  14. Point-source inversion techniques

    Science.gov (United States)

    Langston, Charles A.; Barker, Jeffrey S.; Pavlin, Gregory B.

    1982-11-01

    A variety of approaches for obtaining source parameters from waveform data using moment-tensor or dislocation point source models have been investigated and applied to long-period body and surface waves from several earthquakes. Generalized inversion techniques have been applied to data for long-period teleseismic body waves to obtain the orientation, time function and depth of the 1978 Thessaloniki, Greece, event, of the 1971 San Fernando event, and of several events associated with the 1963 induced seismicity sequence at Kariba, Africa. The generalized inversion technique and a systematic grid testing technique have also been used to place meaningful constraints on mechanisms determined from very sparse data sets; a single station with high-quality three-component waveform data is often sufficient to discriminate faulting type (e.g., strike-slip, etc.). Sparse data sets for several recent California earthquakes, for a small regional event associated with the Koyna, India, reservoir, and for several events at the Kariba reservoir have been investigated in this way. Although linearized inversion techniques using the moment-tensor model are often robust, even for sparse data sets, there are instances where the simplifying assumption of a single point source is inadequate to model the data successfully. Numerical experiments utilizing synthetic data and actual data for the 1971 San Fernando earthquake graphically demonstrate that severe problems may be encountered if source finiteness effects are ignored. These techniques are generally applicable to on-line processing of high-quality digital data, but source complexity and inadequacy of the assumed Green's functions are major problems which are yet to be fully addressed.

  15. Inversion of GPS meteorology data

    Directory of Open Access Journals (Sweden)

    K. Hocke

    Full Text Available The GPS meteorology (GPS/MET experiment, led by the Universities Corporation for Atmospheric Research (UCAR, consists of a GPS receiver aboard a low earth orbit (LEO satellite which was launched on 3 April 1995. During a radio occultation the LEO satellite rises or sets relative to one of the 24 GPS satellites at the Earth's horizon. Thereby the atmospheric layers are successively sounded by radio waves which propagate from the GPS satellite to the LEO satellite. From the observed phase path increases, which are due to refraction of the radio waves by the ionosphere and the neutral atmosphere, the atmospheric parameter refractivity, density, pressure and temperature are calculated with high accuracy and resolution (0.5–1.5 km. In the present study, practical aspects of the GPS/MET data analysis are discussed. The retrieval is based on the Abelian integral inversion of the atmospheric bending angle profile into the refractivity index profile. The problem of the upper boundary condition of the Abelian integral is described by examples. The statistical optimization approach which is applied to the data above 40 km and the use of topside bending angle profiles from model atmospheres stabilize the inversion. The retrieved temperature profiles are compared with corresponding profiles which have already been calculated by scientists of UCAR and Jet Propulsion Laboratory (JPL, using Abelian integral inversion too. The comparison shows that in some cases large differences occur (5 K and more. This is probably due to different treatment of the upper boundary condition, data runaways and noise. Several temperature profiles with wavelike structures at tropospheric and stratospheric heights are shown. While the periodic structures at upper stratospheric heights could be caused by residual errors of the ionospheric correction method, the periodic temperature fluctuations at heights below 30 km are most likely caused by atmospheric waves (vertically

  16. Peak Electric Load Relief in Northern Manhattan

    Directory of Open Access Journals (Sweden)

    Hildegaard D. Link

    2014-08-01

    Full Text Available The aphorism “Think globally, act locally,” attributed to René Dubos, reflects the vision that the solution to global environmental problems must begin with efforts within our communities. PlaNYC 2030, the New York City sustainability plan, is the starting point for this study. Results include (a a case study based on the City College of New York (CCNY energy audit, in which we model the impacts of green roofs on campus energy demand and (b a case study of energy use at the neighborhood scale. We find that reducing the urban heat island effect can reduce building cooling requirements, peak electricity loads stress on the local electricity grid and improve urban livability.

  17. Tim Peake and Britain's road to space

    CERN Document Server

    Seedhouse, Erik

    2017-01-01

    This book puts the reader in the flight suit of Britain’s first male astronaut, Tim Peake. It chronicles his life, along with the Principia mission and the down-to-the-last-bolt descriptions of life aboard the ISS, by way of the hurdles placed by the British government and the rigors of training at Russia’s Star City military base. In addition, this book discusses the learning curves required in astronaut and mission training and the complexity of the technologies required to launch an astronaut and keep them alive for months on end. This book underscores the fact that technology and training, unlike space, do not exist in a vacuum; complex technical systems, like the ISS, interact with the variables of human personality, and the cultural background of the astronauts. .

  18. Complex behavior of elevators in peak traffic

    Science.gov (United States)

    Nagatani, Takashi

    2003-08-01

    We study the dynamical behavior of elevators in the morning peak traffic. We present a stochastic model of the elevators to take into account the interactions between elevators through passengers. The dynamics of the elevators is expressed in terms of a coupled nonlinear map with noises. The number of passengers carried by an elevator and the time-headway between elevators exhibit the complex behavior with varying elevator trips. It is found that the behavior of elevators exhibits a deterministic chaos even if there are no noises. The chaotic motion depends on the loading parameter, the maximum capacity of an elevator, and the number of elevators. When the loading parameter is superior to the threshold, each elevator carries a full load of passengers throughout its trip. The dependence of the threshold (transition point) on the elevator capacity is clarified.

  19. Equivalence principle and the baryon acoustic peak

    Science.gov (United States)

    Baldauf, Tobias; Mirbabayi, Mehrdad; Simonović, Marko; Zaldarriaga, Matias

    2015-08-01

    We study the dominant effect of a long wavelength density perturbation δ (λL) on short distance physics. In the nonrelativistic limit, the result is a uniform acceleration, fixed by the equivalence principle, and typically has no effect on statistical averages due to translational invariance. This same reasoning has been formalized to obtain a "consistency condition" on the cosmological correlation functions. In the presence of a feature, such as the acoustic peak at ℓBAO, this naive expectation breaks down for λLexplicitly applied to the one-loop calculation of the power spectrum. Finally, the success of baryon acoustic oscillation reconstruction schemes is argued to be another empirical evidence for the validity of the results.

  20. Quantification of Massive Seasonal Aggregations of Blacktip Sharks (Carcharhinus limbatus) in Southeast Florida.

    Science.gov (United States)

    Kajiura, Stephen M; Tellman, Shari L

    2016-01-01

    Southeast Florida witnesses an enormous seasonal influx of upper trophic level marine predators each year as massive aggregations of migrating blacktip sharks (Carcharhinus limbatus) overwinter in nearshore waters. The narrow shelf and close proximity of the Gulf Stream current to the Palm Beach County shoreline drive tens of thousands of sharks to the shallow, coastal environment. This natural bottleneck provides a unique opportunity to estimate relative abundance. Over a four year period from 2011-2014, an aerial survey was flown approximately biweekly along the length of Palm Beach County. A high definition video camera and digital still camera mounted out of the airplane window provided a continuous record of the belt transect which extended 200 m seaward from the shoreline between Boca Raton Inlet and Jupiter Inlet. The number of sharks within the survey transect was directly counted from the video. Shark abundance peaked in the winter (January-March) with a maximum in 2011 of 12,128 individuals counted within the 75.6 km(-2) belt transect. This resulted in a maximum density of 803.2 sharks km(-2). By the late spring (April-May), shark abundance had sharply declined to 1.1% of its peak, where it remained until spiking again in January of the following year. Shark abundance was inversely correlated with water temperature and large numbers of sharks were found only when water temperatures were less than 25 °C. Shark abundance was also correlated with day of the year but not with barometric pressure. Although shark abundance was not correlated with photoperiod, the departure of the sharks from southeast Florida occurred around the vernal equinox. The shark migration along the United States eastern seaboard corresponds spatially and temporally with the spawning aggregations of various baitfish species. These baseline abundance data can be compared to future studies to determine if shark population size is changing and if sharks are restricting their southward

  1. Comparison of five portable peak flow meters

    Directory of Open Access Journals (Sweden)

    Glaucia Nency Takara

    2010-01-01

    Full Text Available OBJECTIVE: To compare the measurements of spirometric peak expiratory flow (PEF from five different PEF meters and to determine if their values are in agreement. Inaccurate equipment may result in incorrect diagnoses of asthma and inappropriate treatments. METHODS: Sixty-eight healthy, sedentary and insufficiently active subjects, aged from 19 to 40 years, performed PEF measurements using Air Zone®, Assess®, Galemed®, Personal Best® and Vitalograph® peak flow meters. The highest value recorded for each subject for each device was compared to the corresponding spirometric values using Friedman's test with Dunn's post-hoc (p<0.05, Spearman's correlation test and Bland-Altman's agreement test. RESULTS: The median and interquartile ranges for the spirometric values and the Air Zone®, Assess®, Galemed®, Personal Best® and Vitalograph® meters were 428 (263-688 L/min, 450 (350-800 L/min, 420 (310-720 L/min, 380 (300-735 L/min, 400 (310-685 L/min and 415 (335-610 L/min, respectively. Significant differences were found when the spirometric values were compared to those recorded by the Air Zone® (p<0.001 and Galemed ® (p<0.01 meters. There was no agreement between the spirometric values and the five PEF meters. CONCLUSIONS: The results suggest that the values recorded from Galemed® meters may underestimate the actual value, which could lead to unnecessary interventions, and that Air Zone® meters overestimate spirometric values, which could obfuscate the need for intervention. These findings must be taken into account when interpreting both devices' results in younger people. These differences should also be considered when directly comparing values from different types of PEF meters.

  2. GNBP domain of Anopheles darlingi: are polymorphic inversions and gene variation related to adaptive evolution?

    Science.gov (United States)

    Bridi, L C; Rafael, M S

    2016-02-01

    Anopheles darlingi is the main malaria vector in humans in South America. In the Amazon basin, it lives along the banks of rivers and lakes, which responds to the annual hydrological cycle (dry season and rainy season). In these breeding sites, the larvae of this mosquito feed on decomposing organic and microorganisms, which can be pathogenic and trigger the activation of innate immune system pathways, such as proteins Gram-negative binding protein (GNBP). Such environmental changes affect the occurrence of polymorphic inversions especially at the heterozygote frequency, which confer adaptative advantage compared to homozygous inversions. We mapped the GNBP probe to the An. darlingi 2Rd inversion by fluorescent in situ hybridization (FISH), which was a good indicator of the GNBP immune response related to the chromosomal polymorphic inversions and adaptative evolution. To better understand the evolutionary relations and time of divergence of the GNBP of An. darlingi, we compared it with nine other mosquito GNBPs. The results of the phylogenetic analysis of the GNBP sequence between the species of mosquitoes demonstrated three clades. Clade I and II included the GNBPB5 sequence, and clade III the sequence of GNBPB1. Most of these sequences of GNBP analyzed were homologous with that of subfamily B, including that of An. gambiae (87 %), therefore suggesting that GNBP of An. darling belongs to subfamily B. This work helps us understand the role of inversion polymorphism in evolution of An. darlingi.

  3. NEW SEASON NEW HOPES: OFF-SEASON OPTIMISM

    Directory of Open Access Journals (Sweden)

    Oguz Ersan

    2017-12-01

    Full Text Available While literature on the relation between on-field sports performance and stock returns is ample, there is very limited evidence on off-season stage. Constituting around 3 months, off-seasons do not only occupy a significant part of the year but also represent totally different characteristics than on-seasons. They lack the periodic, unambiguous news events in on-seasons (match results, instead they are associated with highly uncertain transfer news and rumors. We show that this distinction has several impacts on the stock market performances of soccer clubs. Most notably, off-seasons generate substantially higher (excess returns. After controlling for other variables, the estimated effect of off-season periods is as high as 38.75%, annually. In line with several seminal studies, we link this fact to increased optimism and betting behavior through uncertain periods; and periods prior to the start of a new calendar (in our case, new season. For all of the examined 7 clubs (3 from Italy and 4 from Turkey, mean excess returns over the market are positive (negative in off-seasons (on-seasons. On-seasons are associated with increased trading activity due to more frequent news. Stocks of Italian clubs are evidently more volatile through off-seasons while volatility results for the stocks of Turkish clubs are not consistent.

  4. Enhancing Seasonal Water Outlooks: Needs and Opportunities in the Critical Runoff Season

    Science.gov (United States)

    Ray, A. J.; Barsugli, J. J.; Yocum, H.; Stokes, M.; Miskus, D.

    2017-12-01

    The runoff season is a critical period for the management of water supply in the western U.S., where in many places over 70% of the annual runoff occurs in the snowmelt period. Managing not only the volume, but the intra-seasonal timing of the runoff is important for optimizing storage, as well as achieving other goals such as mitigating flood risk, and providing peak flows for riparian habitat management, for example, for endangered species. Western river forecast centers produce volume forecasts for western reservoirs that are key input into many water supply decisions, and also short term river forecasts out to 10 days. The early volume forecasts each year typically begin in December, and are updated throughout the winter and into the runoff season (April-July for many areas, but varies). This presentation will discuss opportunities for enhancing this existing suite of RFC water outlooks, including the needs for and potential use for "intraseasonal" products beyond those provided by the Ensemble Streamflow Prediction system and the volume forecasts. While precipitation outlooks have little skill for many areas and seasons, and may not contribute significantly to the outlook, late winter and spring temperature forecasts have meaningful skill in certain areas and sub-seasonal to seasonal time scales. This current skill in CPC temperature outlooks is an opportunity to translate these products into information about the snowpack and potential runoff timing, even where the skill in precipitation is low. Temperature is important for whether precipitation falls as snow or rain, which is critical for streamflow forecasts, especially in the melt season in snowpack-dependent watersheds. There is a need for better outlooks of the evolution of snowpack, conditions influencing the April-July runoff, and the timing of spring peak or shape of the spring hydrograph. The presentation will also discuss a our work with stakeholders of the River Forecast Centers and the NIDIS

  5. Analyzing seasonality of tuberculosis across Indian states and union territories

    Directory of Open Access Journals (Sweden)

    Pankaj Narula

    2015-12-01

    Full Text Available A significant seasonal variation in tuberculosis (TB is observed in north India during 2006–2011, particularly in states like Himachal Pradesh, Haryana and Rajasthan. To quantify the seasonal variation, we measure average amplitude (peak to trough distance across seasons in smear positive cases of TB and observe that it is maximum for Himachal Pradesh (40.01% and minimum for Maharashtra (3.87%. In north India, smear positive cases peak in second quarter (April–June and reach a trough in fourth quarter (October–December, however low seasonal variation is observed in southern region of the country. The significant correlations as 0.64 (p-value < 0.001, 0.54 (p-value < 0.01 and 0.42 (p-value < 0.05 are observed between minimum temperature and seasonality of TB at lag-1 in north, central and northeast India respectively. However, in south India, this correlation is not significant.

  6. Population level evidence for seasonality of the human microbiome.

    Science.gov (United States)

    Korownyk, Christina; Liu, Fangwei; Garrison, Scott

    2018-04-01

    The objective of this study is to determine whether human body odors undergo seasonal modulation. We utilized google trends search volume from the United States of America from January 1, 2010 to June 24, 2017 for a number of predetermined body odors. Regression modeling of time series data was completed. Our primary outcome was to determine the proportion of the variability in Internet searches for each unpleasant odor (about the mean) that is explained by a seasonal model. We determined that the seasonal (sinusoidal) model provided a significantly better fit than the null model (best straight line fit) for all searches relating to human body odors (P odor, 60% of the variability in search volume for foot odor, and 58% of the variability in search volume for bad breath. Flatulence and bad breath tended to peak in January, foot odor in February, and Axillary odor in July. We conclude that searching by the general public for information on unpleasant body odors undergoes substantial seasonal variation, with the timing of peaks and troughs varying with the body part involved. The symptom burden of such smells may have a similar seasonal variation, as might the composition of the commensal bacterial microflora that play a role in creating them.

  7. Cognitive Resilience and Psychological Responses across a Collegiate Rowing Season.

    Science.gov (United States)

    Shields, Morgan R; Brooks, M Alison; Koltyn, Kelli F; Kim, Jee-Seon; Cook, Dane B

    2017-11-01

    Student-athletes face numerous challenges across their competitive season. Although mood states have been previously studied, little is known about adaptations in other psychological responses, specifically cognition. The purpose of this study was to characterize cognitive function, mood, sleep, and stress responses at select time points of a season in collegiate rowers. It was hypothesized that during baseline, typical training, and recovery, athletes would show positive mental health profiles, in contrast to decreases in cognition with increases in negative mood and measurements of stress during peak training. Male and female Division I rowers (N = 43) and healthy controls (N = 23) were enrolled and assessed at baseline, typical training, peak training, and recovery. At each time point, measures of cognitive performance (Stroop color-naming task), academic and exercise load, perceived cognitive deficits, mood states, sleep, and stress (via self-report and salivary cortisol) were recorded. Repeated-measures ANOVA revealed significant group-time interactions for perceived exercise load, cognitive deficits, mood states, and perceived stress (P cognitive deficits was positively correlated with mood disturbance (r = 0.54, P Cognitive performance did not change over the course of the season for either group. Cortisol and sleepiness changed over the course of the season but no significant interactions were observed. These results demonstrate that various psychological responses change over the course of a season, but they also highlight adaptation indicative of cognitive resilience among student-athletes.

  8. Inverse problems in systems biology

    International Nuclear Information System (INIS)

    Engl, Heinz W; Lu, James; Müller, Stefan; Flamm, Christoph; Schuster, Peter; Kügler, Philipp

    2009-01-01

    Systems biology is a new discipline built upon the premise that an understanding of how cells and organisms carry out their functions cannot be gained by looking at cellular components in isolation. Instead, consideration of the interplay between the parts of systems is indispensable for analyzing, modeling, and predicting systems' behavior. Studying biological processes under this premise, systems biology combines experimental techniques and computational methods in order to construct predictive models. Both in building and utilizing models of biological systems, inverse problems arise at several occasions, for example, (i) when experimental time series and steady state data are used to construct biochemical reaction networks, (ii) when model parameters are identified that capture underlying mechanisms or (iii) when desired qualitative behavior such as bistability or limit cycle oscillations is engineered by proper choices of parameter combinations. In this paper we review principles of the modeling process in systems biology and illustrate the ill-posedness and regularization of parameter identification problems in that context. Furthermore, we discuss the methodology of qualitative inverse problems and demonstrate how sparsity enforcing regularization allows the determination of key reaction mechanisms underlying the qualitative behavior. (topical review)

  9. The seismic reflection inverse problem

    International Nuclear Information System (INIS)

    Symes, W W

    2009-01-01

    The seismic reflection method seeks to extract maps of the Earth's sedimentary crust from transient near-surface recording of echoes, stimulated by explosions or other controlled sound sources positioned near the surface. Reasonably accurate models of seismic energy propagation take the form of hyperbolic systems of partial differential equations, in which the coefficients represent the spatial distribution of various mechanical characteristics of rock (density, stiffness, etc). Thus the fundamental problem of reflection seismology is an inverse problem in partial differential equations: to find the coefficients (or at least some of their properties) of a linear hyperbolic system, given the values of a family of solutions in some part of their domains. The exploration geophysics community has developed various methods for estimating the Earth's structure from seismic data and is also well aware of the inverse point of view. This article reviews mathematical developments in this subject over the last 25 years, to show how the mathematics has both illuminated innovations of practitioners and led to new directions in practice. Two themes naturally emerge: the importance of single scattering dominance and compensation for spectral incompleteness by spatial redundancy. (topical review)

  10. Inversion theory and conformal mapping

    CERN Document Server

    Blair, David E

    2000-01-01

    It is rarely taught in an undergraduate or even graduate curriculum that the only conformal maps in Euclidean space of dimension greater than two are those generated by similarities and inversions in spheres. This is in stark contrast to the wealth of conformal maps in the plane. The principal aim of this text is to give a treatment of this paucity of conformal maps in higher dimensions. The exposition includes both an analytic proof in general dimension and a differential-geometric proof in dimension three. For completeness, enough complex analysis is developed to prove the abundance of conformal maps in the plane. In addition, the book develops inversion theory as a subject, along with the auxiliary theme of circle-preserving maps. A particular feature is the inclusion of a paper by Carath�odory with the remarkable result that any circle-preserving transformation is necessarily a M�bius transformation, not even the continuity of the transformation is assumed. The text is at the level of advanced undergr...

  11. Inverse design of multicomponent assemblies

    Science.gov (United States)

    Piñeros, William D.; Lindquist, Beth A.; Jadrich, Ryan B.; Truskett, Thomas M.

    2018-03-01

    Inverse design can be a useful strategy for discovering interactions that drive particles to spontaneously self-assemble into a desired structure. Here, we extend an inverse design methodology—relative entropy optimization—to determine isotropic interactions that promote assembly of targeted multicomponent phases, and we apply this extension to design interactions for a variety of binary crystals ranging from compact triangular and square architectures to highly open structures with dodecagonal and octadecagonal motifs. We compare the resulting optimized (self- and cross) interactions for the binary assemblies to those obtained from optimization of analogous single-component systems. This comparison reveals that self-interactions act as a "primer" to position particles at approximately correct coordination shell distances, while cross interactions act as the "binder" that refines and locks the system into the desired configuration. For simpler binary targets, it is possible to successfully design self-assembling systems while restricting one of these interaction types to be a hard-core-like potential. However, optimization of both self- and cross interaction types appears necessary to design for assembly of more complex or open structures.

  12. Instrument developments for inverse photoemission

    International Nuclear Information System (INIS)

    Brenac, A.

    1987-02-01

    Experimental developments principally concerning electron sources for inverse photoemission are presented. The specifications of the electron beam are derived from experiment requirements, taking into account the limitations encountered (space charge divergence). For a wave vector resolution of 0.2 A -1 , the maximum current is 25 microA at 20 eV. The design of a gun providing such a beam in the range 5 to 50 eV is presented. Angle-resolved inverse photoemission experiments show angular effects at 30 eV. For an energy of 10 eV, angular effects should be stronger, but the low efficiency of the spectrometer in this range makes the experiments difficult. The total energy resolution of 0.3 eV is the result mainly of electron energy spread, as expected. The electron sources are based on field effect electron emission from a cathode consisting of a large number of microtips. The emission arises from a few atomic cells for each tip. The ultimate theoretical energy spread is 0.1 eV. This value is not attained because of an interface resistance problem. A partial solution of this problem allows measurement of an energy spread of 0.9 eV for a current of 100 microA emitted at 60 eV. These cathodes have a further advantage in that emission can occur at a low temperature [fr

  13. Seasonal rhythms of seed rain and seedling emergence in two tropical rain forests in southern Brazil.

    Science.gov (United States)

    Marques, M C M; Oliveira, P E A M

    2008-09-01

    Seasonal tropical forests show rhythms in reproductive activities due to water stress during dry seasons. If both seed dispersal and seed germination occur in the best environmental conditions, mortality will be minimised and forest regeneration will occur. To evaluate whether non-seasonal forests also show rhythms, for 2 years we studied the seed rain and seedling emergence in two sandy coastal forests (flooded and unflooded) in southern Brazil. In each forest, one 100 x 30-m grid was marked and inside it 30 stations comprising two seed traps (0.5 x 0.5 m each) and one plot (2 x 2 m) were established for monthly monitoring of seed rain and a seedling emergence study, respectively. Despite differences in soil moisture and incident light on the understorey, flooded and unflooded forests had similar dispersal and germination patterns. Seed rain was seasonal and bimodal (peaks at the end of the wetter season and in the less wet season) and seedling emergence was seasonal and unimodal (peaking in the wetter season). Approximately 57% of the total species number had seedling emergence 4 or more months after dispersal. Therefore, both seed dormancy and the timing of seed dispersal drive the rhythm of seedling emergence in these forests. The peak in germination occurs in the wetter season, when soil fertility is higher and other phenological events also occur. The strong seasonality in these plant communities, even in this weakly seasonal climate, suggests that factors such as daylength, plant sensitivity to small changes in the environment (e.g. water and nutrient availability) or phylogenetic constraints cause seasonal rhythms in the plants.

  14. Inverse problems and inverse scattering of plane waves

    CERN Document Server

    Ghosh Roy, Dilip N

    2001-01-01

    The purpose of this text is to present the theory and mathematics of inverse scattering, in a simple way, to the many researchers and professionals who use it in their everyday research. While applications range across a broad spectrum of disciplines, examples in this text will focus primarly, but not exclusively, on acoustics. The text will be especially valuable for those applied workers who would like to delve more deeply into the fundamentally mathematical character of the subject matter.Practitioners in this field comprise applied physicists, engineers, and technologists, whereas the theory is almost entirely in the domain of abstract mathematics. This gulf between the two, if bridged, can only lead to improvement in the level of scholarship in this highly important discipline. This is the book''s primary focus.

  15. Norwegian hydropower a valuable peak power source

    Energy Technology Data Exchange (ETDEWEB)

    Brekke, Hermod

    2010-07-01

    given on a possible increase of the Norwegian hydropower peak power production to meet the growing the European demand for peak power caused by the growing non stationary production from wind mills and ocean energy from waves and sea current. Also building of reversible pump turbine power plants will be discussed even if approximately 10% power will be consumed by loss in the pumping phase compared to direct use of the water from reservoirs. (Author)

  16. Can You Hear That Peak? Utilization of Auditory and Visual Feedback at Peak Limb Velocity

    Science.gov (United States)

    Loria, Tristan; de Grosbois, John; Tremblay, Luc

    2016-01-01

    Purpose: At rest, the central nervous system combines and integrates multisensory cues to yield an optimal percept. When engaging in action, the relative weighing of sensory modalities has been shown to be altered. Because the timing of peak velocity is the critical moment in some goal-directed movements (e.g., overarm throwing), the current study…

  17. OccuPeak: ChIP-Seq peak calling based on internal background modelling

    NARCIS (Netherlands)

    de Boer, Bouke A.; van Duijvenboden, Karel; van den Boogaard, Malou; Christoffels, Vincent M.; Barnett, Phil; Ruijter, Jan M.

    2014-01-01

    ChIP-seq has become a major tool for the genome-wide identification of transcription factor binding or histone modification sites. Most peak-calling algorithms require input control datasets to model the occurrence of background reads to account for local sequencing and GC bias. However, the

  18. Forecasting monthly peak demand of electricity in India—A critique

    International Nuclear Information System (INIS)

    Rallapalli, Srinivasa Rao; Ghosh, Sajal

    2012-01-01

    The nature of electricity differs from that of other commodities since electricity is a non-storable good and there have been significant seasonal and diurnal variations of demand. Under such condition, precise forecasting of demand for electricity should be an integral part of the planning process as this enables the policy makers to provide directions on cost-effective investment and on scheduling the operation of the existing and new power plants so that the supply of electricity can be made adequate enough to meet the future demand and its variations. Official load forecasting in India done by Central Electricity Authority (CEA) is often criticized for being overestimated due to inferior techniques used for forecasting. This paper tries to evaluate monthly peak demand forecasting performance predicted by CEA using trend method and compare it with those predicted by Multiplicative Seasonal Autoregressive Integrated Moving Average (MSARIMA) model. It has been found that MSARIMA model outperforms CEA forecasts both in-sample static and out-of-sample dynamic forecast horizons in all five regional grids in India. For better load management and grid discipline, this study suggests employing sophisticated techniques like MSARIMA for peak load forecasting in India. - Highlights: ► This paper evaluates monthly peak demand forecasting performance by CEA. ► Compares CEA forecasts it with those predicted by MSARIMA model. ► MSARIMA model outperforms CEA forecasts in all five regional grids in India. ► Opportunity exists to improve the performance of CEA forecasts.

  19. Hydroclimatology of Dual Peak Cholera Incidence in Bengal Region: Inferences from a Spatial Explicit Model

    Science.gov (United States)

    Bertuzzo, E.; Mari, L.; Righetto, L.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2010-12-01

    The seasonality of cholera and its relation with environmental drivers are receiving increasing interest and research efforts, yet they remain unsatisfactorily understood. A striking example is the observed annual cycle of cholera incidence in the Bengal region which exhibits two peaks despite the main environmental drivers that have been linked to the disease (air and sea surface temperature, zooplankton density, river discharge) follow a synchronous single-peak annual pattern. A first outbreak, mainly affecting the coastal regions, occurs in spring and it is followed, after a period of low incidence during summer, by a second, usually larger, peak in autumn also involving regions situated farther inland. A hydroclimatological explanation for this unique seasonal cycle has been recently proposed: the low river spring flows favor the intrusion of brackish water (the natural environment of the causative agent of the disease) which, in turn, triggers the first outbreak. The summer rising river discharges have a temporary dilution effect and prompt the repulsion of contaminated water which lowers the disease incidence. However, the monsoon flooding, together with the induced crowding of the population and the failure of the sanitation systems, can possibly facilitate the spatial transmission of the disease and promote the autumn outbreak. We test this hypothesis using a mechanistic, spatially explicit model of cholera epidemic. The framework directly accounts for the role of the river network in transporting and redistributing cholera bacteria among human communities as well as for the annual fluctuation of the river flow. The model is forced with the actual environmental drivers of the region, namely river flow and temperature. Our results show that these two drivers, both having a single peak in the summer, can generate a double peak cholera incidence pattern. Besides temporal patterns, the model is also able to qualitatively reproduce spatial patterns characterized

  20. Quantifying seasonal velocity at Khumbu Glacier, Nepal

    Science.gov (United States)

    Miles, E.; Quincey, D. J.; Miles, K.; Hubbard, B. P.; Rowan, A. V.

    2017-12-01

    While the low-gradient debris-covered tongues of many Himalayan glaciers exhibit low surface velocities, quantifying ice flow and its variation through time remains a key challenge for studies aimed at determining the long-term evolution of these glaciers. Recent work has suggested that glaciers in the Everest region of Nepal may show seasonal variability in surface velocity, with ice flow peaking during the summer as monsoon precipitation provides hydrological inputs and thus drives changes in subglacial drainage efficiency. However, satellite and aerial observations of glacier velocity during the monsoon are greatly limited due to cloud cover. Those that do exist do not span the period over which the most dynamic changes occur, and consequently short-term (i.e. daily) changes in flow, as well as the evolution of ice dynamics through the monsoon period, remain poorly understood. In this study, we combine field and remote (satellite image) observations to create a multi-temporal, 3D synthesis of ice deformation rates at Khumbu Glacier, Nepal, focused on the 2017 monsoon period. We first determine net annual and seasonal surface displacements for the whole glacier based on Landsat-8 (OLI) panchromatic data (15m) processed with ImGRAFT. We integrate inclinometer observations from three boreholes drilled by the EverDrill project to determine cumulative deformation at depth, providing a 3D perspective and enabling us to assess the role of basal sliding at each site. We additionally analyze high-frequency on-glacier L1 GNSS data from three sites to characterize variability within surface deformation at sub-seasonal timescales. Finally, each dataset is validated against repeat-dGPS observations at gridded points in the vicinity of the boreholes and GNSS dataloggers. These datasets complement one another to infer thermal regime across the debris-covered ablation area of the glacier, and emphasize the seasonal and spatial variability of ice deformation for glaciers in High

  1. Prediction of iodine activity peak during refuelling

    International Nuclear Information System (INIS)

    Hozer, Z.; Vajda, N.

    2001-01-01

    The increase of fission product activities in the primary circuit of a nuclear power plant indicates the existence of defects in some fuel rods. The power change leads to the cooling down of the fuel and results in the fragmentation of the UO 2 pellets, which facilitates the release of fission products from the intergranular regions. Furthermore the injection of boric acid after shutdown will increase the primary activity, due to the solution of deposited fission products from the surface of the core components. The calculation of these phenomena usually is based on the evaluation of activity measurements and power plant data. The estimation of iodine spiking peak during reactor transients is based on correlation with operating parameters, such as reactor power and primary pressure. The approach used in the present method was applied for CANDU reactors. The VVER-440 specific correlations were determined using the activity measurements of the Paks NPP and the data provided by the Russian fuel supplier. The present method is used for the evaluation of the iodine isotopes, as well as the noble gases. A numerical model has been developed for iodine spiking simulation and has been validated against several shutdown transients, measured at Paks NPP. (R.P.)

  2. Fast clustering using adaptive density peak detection.

    Science.gov (United States)

    Wang, Xiao-Feng; Xu, Yifan

    2017-12-01

    Common limitations of clustering methods include the slow algorithm convergence, the instability of the pre-specification on a number of intrinsic parameters, and the lack of robustness to outliers. A recent clustering approach proposed a fast search algorithm of cluster centers based on their local densities. However, the selection of the key intrinsic parameters in the algorithm was not systematically investigated. It is relatively difficult to estimate the "optimal" parameters since the original definition of the local density in the algorithm is based on a truncated counting measure. In this paper, we propose a clustering procedure with adaptive density peak detection, where the local density is estimated through the nonparametric multivariate kernel estimation. The model parameter is then able to be calculated from the equations with statistical theoretical justification. We also develop an automatic cluster centroid selection method through maximizing an average silhouette index. The advantage and flexibility of the proposed method are demonstrated through simulation studies and the analysis of a few benchmark gene expression data sets. The method only needs to perform in one single step without any iteration and thus is fast and has a great potential to apply on big data analysis. A user-friendly R package ADPclust is developed for public use.

  3. Transient thermal hydraulic analysis of the IAEA 10 MW MTR reactor during Loss of Flow Accident to investigate the flow inversion

    International Nuclear Information System (INIS)

    AL-Yahia, Omar S.; Albati, Mohammad A.; Park, Jonghark; Chae, Heetaek; Jo, Daeseong

    2013-01-01

    Highlights: • Transient analyses of a slow and fast LOFA were investigated. • A reactor kinetic and thermal hydraulic coupled model was developed. • Based on force balance, the flow rate during flow inversion was determined. • Flow inversion in a hot channel occurred earlier than in an average channel. • Two temperature peaks were observed during both slow and fast LOFA. - Abstract: Transient analyses of the IAEA 10 MW MTR reactor are investigated during a fast and slow Loss of Flow Accident (LOFA) with a neutron kinetic and thermal hydraulic coupling model. A spatial-dependent thermal hydraulic technique is adopted for analyzing the local thermal hydraulic parameters and hotspot location during a flow inversion. The flow rate through the channel is determined in terms of a balance between driving and preventing forces. Friction and buoyancy forces act as resistance of the flow before a flow inversion while buoyancy force becomes the driving force after a flow inversion. By taking into account the buoyancy effect to determine the flow rate, the difference in the flow inversion time between hot and average channels is investigated: a flow inversion occurs earlier in the hot channel than in an average channel. Furthermore, the movement of the hotspot location before and after a flow inversion is investigated for a slow and fast LOFA. During a flow inversion, two temperature peaks are observed: (1) the first temperature peak is at the initiation of the LOFA, and (2) the second temperature peak is when a flow inversion occurs. The maximum temperature of the cladding is found at the second temperature peak for both LOFA analyses, and is lower than the saturation temperature

  4. Price, environment and security: Exploring multi-modal motivation in voluntary residential peak demand response

    International Nuclear Information System (INIS)

    Gyamfi, Samuel; Krumdieck, Susan

    2011-01-01

    Peak demand on electricity grids is a growing problem that increases costs and risks to supply security. Residential sector loads often contribute significantly to seasonal and daily peak demand. Demand response projects aim to manage peak demand by applying price signals and automated load shedding technologies. This research investigates voluntary load shedding in response to information about the security of supply, the emission profile and the cost of meeting critical peak demand in the customers' network. Customer willingness to change behaviour in response to this information was explored through mail-back survey. The diversified demand modelling method was used along with energy audit data to estimate the potential peak load reduction resulting from the voluntary demand response. A case study was conducted in a suburb of Christchurch, New Zealand, where electricity is the main source for water and space heating. On this network, all water heating cylinders have ripple-control technology and about 50% of the households subscribe to differential day/night pricing plan. The survey results show that the sensitivity to supply security is on par with price, with the emission sensitivity being slightly weaker. The modelling results show potential 10% reduction in critical peak load for aggregate voluntary demand response. - Highlights: → Multiple-factor behaviour intervention is necessarily for effective residential demand response. → Security signals can achieve result comparable to price. → The modelling results show potential 10% reduction in critical peak load for aggregate voluntary demand response. → New Zealand's energy policy should include innovation and development of VDR programmes and technologies.

  5. Season and preterm birth in Norway: A cautionary tale.

    Science.gov (United States)

    Weinberg, Clarice R; Shi, Min; DeRoo, Lisa A; Basso, Olga; Skjærven, Rolv

    2015-06-01

    Preterm birth is a common, costly and dangerous pregnancy complication. Seasonality of risk would suggest modifiable causes. We examine seasonal effects on preterm birth, using data from the Medical Birth Registry of Norway (2,321,652 births), and show that results based on births are misleading and a fetuses-at-risk approach is essential. In our harmonic-regression Cox proportional hazards model we consider fetal risk of birth between 22 and 37 completed weeks of gestation. We examine effects of both day of year of conception (for early effects) and day of ongoing gestation (for seasonal effects on labour onset) as modifiers of gestational-age-based risk. Naïve analysis of preterm rates across days of birth shows compelling evidence for seasonality (P distribution of the fetal population at risk. When we instead properly treat fetuses as the individuals at risk, restrict analysis to pregnancies with relatively accurate ultrasound-based assessment of gestational age (available since 1998) and adjust for socio-demographic factors and maternal smoking, we find modest effects of both time of year of conception and time of year at risk, with peaks for early preterm near early January and early July. Analyses of seasonal effects on preterm birth are demonstrably vulnerable to confounding by seasonality of conception, measurement error in conception dating, and socio-demographic factors. The seasonal variation based on fetuses reveals two peaks for early preterm, coinciding with New Year's Day and the early July beginning of Norway's summer break, and may simply reflect a holiday-related pattern of unintended conception. Published by Oxford University Press on behalf of the International Epidemiological Association 2015. This work is written by a US Government employee and is in the public domain in the US.

  6. Music season coming soon

    CERN Multimedia

    CERN Bulletin in collaboration with Julio Rosenfeld

    2012-01-01

    On 16 June, CERN’s music season will open with Music on the Lawn. The event is the CERN Music Club’s contribution to the Fete de la Musique and will take place on the terrace of Restaurant 1 from 2 p.m. to 8 p.m. The Hardronic Festival, CERN’s long-running rock festival, will be held on the evenings of 20 and 21 July in Prévessin, on the terrace behind Restaurant 3. If you would like to help with the organisation, please contact the Music Club by e-mail: music.club@cern.ch.   The Canettes Blues Band during the 2011 Hardronic Festival. (© Christoph Balle, 2010). Summer is coming, and along with it comes the music season. CERN will be hosting its two annual rock music concerts: Music on the Lawn and the Hardronic Festival. The two events are organised by the CERN Music Club, which has been sharing the enjoyment of good music with its numerous fans for many years. “Music on the Lawn was originally created so that the members of the Mus...

  7. Vaccination against seasonal influenza

    CERN Multimedia

    SC Unit

    2009-01-01

    As every year, the Medical Service is taking part in the campaign to promote vaccination against seasonal influenza. Vaccination against seasonal influenza is especially recommended for people suffering from chronic lung, cardio-vascular or kidney conditions or diabetes, for those recovering from a serious illness or surgical operation and for everyone over the age of 65. The influenza virus is transmitted by air and contact with contaminated surfaces, hence the importance of washing hands regularly with soap and / or disinfection using a hydro-alcoholic solution. From the onset of symptoms (fever> 38°, chills, cough, muscle aches and / or joint pain, fatigue) you are strongly recommended to stay at home to avoid spreading the virus. In the present context of the influenza A (H1N1) pandemic, it is important to dissociate these two illnesses and emphasise that the two viruses and the vaccines used to combat them are quite different and that protection against one will not provide protection against the...

  8. Wake Vortex Inverse Model User's Guide

    Science.gov (United States)

    Lai, David; Delisi, Donald

    2008-01-01

    NorthWest Research Associates (NWRA) has developed an inverse model for inverting landing aircraft vortex data. The data used for the inversion are the time evolution of the lateral transport position and vertical position of both the port and starboard vortices. The inverse model performs iterative forward model runs using various estimates of vortex parameters, vertical crosswind profiles, and vortex circulation as a function of wake age. Forward model predictions of lateral transport and altitude are then compared with the observed data. Differences between the data and model predictions guide the choice of vortex parameter values, crosswind profile and circulation evolution in the next iteration. Iterations are performed until a user-defined criterion is satisfied. Currently, the inverse model is set to stop when the improvement in the rms deviation between the data and model predictions is less than 1 percent for two consecutive iterations. The forward model used in this inverse model is a modified version of the Shear-APA model. A detailed description of this forward model, the inverse model, and its validation are presented in a different report (Lai, Mellman, Robins, and Delisi, 2007). This document is a User's Guide for the Wake Vortex Inverse Model. Section 2 presents an overview of the inverse model program. Execution of the inverse model is described in Section 3. When executing the inverse model, a user is requested to provide the name of an input file which contains the inverse model parameters, the various datasets, and directories needed for the inversion. A detailed description of the list of parameters in the inversion input file is presented in Section 4. A user has an option to save the inversion results of each lidar track in a mat-file (a condensed data file in Matlab format). These saved mat-files can be used for post-inversion analysis. A description of the contents of the saved files is given in Section 5. An example of an inversion input

  9. Inverse diffusion theory of photoacoustics

    International Nuclear Information System (INIS)

    Bal, Guillaume; Uhlmann, Gunther

    2010-01-01

    This paper analyzes the reconstruction of diffusion and absorption parameters in an elliptic equation from knowledge of internal data. In the application of photoacoustics, the internal data are the amount of thermal energy deposited by high frequency radiation propagating inside a domain of interest. These data are obtained by solving an inverse wave equation, which is well studied in the literature. We show that knowledge of two internal data based on well-chosen boundary conditions uniquely determines two constitutive parameters in diffusion and Schrödinger equations. Stability of the reconstruction is guaranteed under additional geometric constraints of strict convexity. No geometric constraints are necessary when 2n internal data for well-chosen boundary conditions are available, where n is spatial dimension. The set of well-chosen boundary conditions is characterized in terms of appropriate complex geometrical optics solutions

  10. Action understanding as inverse planning.

    Science.gov (United States)

    Baker, Chris L; Saxe, Rebecca; Tenenbaum, Joshua B

    2009-12-01

    Humans are adept at inferring the mental states underlying other agents' actions, such as goals, beliefs, desires, emotions and other thoughts. We propose a computational framework based on Bayesian inverse planning for modeling human action understanding. The framework represents an intuitive theory of intentional agents' behavior based on the principle of rationality: the expectation that agents will plan approximately rationally to achieve their goals, given their beliefs about the world. The mental states that caused an agent's behavior are inferred by inverting this model of rational planning using Bayesian inference, integrating the likelihood of the observed actions with the prior over mental states. This approach formalizes in precise probabilistic terms the essence of previous qualitative approaches to action understanding based on an "intentional stance" [Dennett, D. C. (1987). The intentional stance. Cambridge, MA: MIT Press] or a "teleological stance" [Gergely, G., Nádasdy, Z., Csibra, G., & Biró, S. (1995). Taking the intentional stance at 12 months of age. Cognition, 56, 165-193]. In three psychophysical experiments using animated stimuli of agents moving in simple mazes, we assess how well different inverse planning models based on different goal priors can predict human goal inferences. The results provide quantitative evidence for an approximately rational inference mechanism in human goal inference within our simplified stimulus paradigm, and for the flexible nature of goal representations that human observers can adopt. We discuss the implications of our experimental results for human action understanding in real-world contexts, and suggest how our framework might be extended to capture other kinds of mental state inferences, such as inferences about beliefs, or inferring whether an entity is an intentional agent.

  11. Circadian and seasonal variation of migraine attacks in children.

    Science.gov (United States)

    Soriani, Stefano; Fiumana, Elisa; Manfredini, Roberto; Boari, Benedetta; Battistella, Pier Antonio; Canetta, Elisabetta; Pedretti, Stefania; Borgna-Pignatti, Caterina

    2006-01-01

    To investigate the rhythmicity of migraine episodes without aura in a pediatric population. Time of occurrence of 2517 migraine attacks in 115 children was recorded, by means of a diary, both by hourly and monthly intervals. A significant circadian variation, characterized by a peak in the afternoon (P < .001) and one in the early morning (P= .002) was found. A seasonal peak was also observed between November and January, while a nadir was observed in July. The clustering of attacks in the morning and midday and in autumn-winter, with a minimum frequency in July, suggests that school activities may represent an important cause of migraine.

  12. Optimization and inverse problems in electromagnetism

    CERN Document Server

    Wiak, Sławomir

    2003-01-01

    From 12 to 14 September 2002, the Academy of Humanities and Economics (AHE) hosted the workshop "Optimization and Inverse Problems in Electromagnetism". After this bi-annual event, a large number of papers were assembled and combined in this book. During the workshop recent developments and applications in optimization and inverse methodologies for electromagnetic fields were discussed. The contributions selected for the present volume cover a wide spectrum of inverse and optimal electromagnetic methodologies, ranging from theoretical to practical applications. A number of new optimal and inverse methodologies were proposed. There are contributions related to dedicated software. Optimization and Inverse Problems in Electromagnetism consists of three thematic chapters, covering: -General papers (survey of specific aspects of optimization and inverse problems in electromagnetism), -Methodologies, -Industrial Applications. The book can be useful to students of electrical and electronics engineering, computer sci...

  13. Reverse Universal Resolving Algorithm and inverse driving

    DEFF Research Database (Denmark)

    Pécseli, Thomas

    2012-01-01

    Inverse interpretation is a semantics based, non-standard interpretation of programs. Given a program and a value, an inverse interpreter finds all or one of the inputs, that would yield the given value as output with normal forward evaluation. The Reverse Universal Resolving Algorithm is a new...... variant of the Universal Resolving Algorithm for inverse interpretation. The new variant outperforms the original algorithm in several cases, e.g., when unpacking a list using inverse interpretation of a pack program. It uses inverse driving as its main technique, which has not been described in detail...... before. Inverse driving may find application with, e.g., supercompilation, thus suggesting a new kind of program inverter....

  14. Relativistic jet feedback - II. Relationship to gigahertz peak spectrum and compact steep spectrum radio galaxies

    Science.gov (United States)

    Bicknell, Geoffrey V.; Mukherjee, Dipanjan; Wagner, Alexander Y.; Sutherland, Ralph S.; Nesvadba, Nicole P. H.

    2018-04-01

    We propose that Gigahertz Peak Spectrum (GPS) and Compact Steep Spectrum (CSS) radio sources are the signposts of relativistic jet feedback in evolving galaxies. Our simulations of relativistic jets interacting with a warm, inhomogeneous medium, utilizing cloud densities and velocity dispersions in the range derived from optical observations, show that free-free absorption can account for the ˜ GHz peak frequencies and low-frequency power laws inferred from the radio observations. These new computational models replace a power-law model for the free-free optical depth a more fundamental model involving disrupted log-normal distributions of warm gas. One feature of our new models is that at early stages, the low-frequency spectrum is steep but progressively flattens as a result of a broader distribution of optical depths, suggesting that the steep low-frequency spectra discovered by Callingham et al. may possibly be attributed to young sources. We also investigate the inverse correlation between peak frequency and size and find that the initial location on this correlation is determined by the average density of the warm ISM. The simulated sources track this correlation initially but eventually fall below it, indicating the need for a more extended ISM than presently modelled. GPS and CSS sources can potentially provide new insights into the phenomenon of AGN feedback since their peak frequencies and spectra are indicative of the density, turbulent structure, and distribution of gas in the host galaxy.

  15. Peak MSC—Are We There Yet?

    Directory of Open Access Journals (Sweden)

    Timothy R. Olsen

    2018-06-01

    Full Text Available Human mesenchymal stem cells (hMSCs are a critical raw material for many regenerative medicine products, including cell-based therapies, engineered tissues, or combination products, and are on the brink of radically changing how the world of medicine operates. Their unique characteristics, potential to treat many indications, and established safety profile in more than 800 clinical trials have contributed to their current consumption and will only fuel future demand. Given the large target patient populations with typical dose sizes of 10's to 100's of millions of cells per patient, and engineered tissues being constructed with 100's of millions to billions of cells, an unprecedented demand has been created for hMSCs. The fulfillment of this demand faces an uphill challenge in the limited availability of large quantities of pharmaceutical grade hMSCs for the industry—fueling the need for parallel rapid advancements in the biomanufacturing of this living critical raw material. Simply put, hMSCs are no different than technologies like transistors, as they are a highly technical and modular product that requires stringent control over manufacturing that can allow for high quality and consistent performance. As hMSC manufacturing processes are optimized, it predicts a future time of abundance for hMSCs, where scientists and researchers around the world will have access to a consistent and readily available supply of high quality, standardized, and economical pharmaceutical grade product to buy off the shelf for their applications and drive product development—this is “Peak MSC.”

  16. Inverse kinematics of OWI-535 robotic arm

    OpenAIRE

    DEBENEC, PRIMOŽ

    2015-01-01

    The thesis aims to calculate the inverse kinematics for the OWI-535 robotic arm. The calculation of the inverse kinematics determines the joint parameters that provide the right pose of the end effector. The pose consists of the position and orientation, however, we will focus only on the second one. Due to arm limitations, we have created our own type of the calculation of the inverse kinematics. At first we have derived it only theoretically, and then we have transferred the derivation into...

  17. Automatic Flight Controller With Model Inversion

    Science.gov (United States)

    Meyer, George; Smith, G. Allan

    1992-01-01

    Automatic digital electronic control system based on inverse-model-follower concept being developed for proposed vertical-attitude-takeoff-and-landing airplane. Inverse-model-follower control places inverse mathematical model of dynamics of controlled plant in series with control actuators of controlled plant so response of combination of model and plant to command is unity. System includes feedback to compensate for uncertainties in mathematical model and disturbances imposed from without.

  18. Lectures on the inverse scattering method

    International Nuclear Information System (INIS)

    Zakharov, V.E.

    1983-06-01

    In a series of six lectures an elementary introduction to the theory of inverse scattering is given. The first four lectures contain a detailed theory of solitons in the framework of the KdV equation, together with the inverse scattering theory of the one-dimensional Schroedinger equation. In the fifth lecture the dressing method is described, while the sixth lecture gives a brief review of the equations soluble by the inverse scattering method. (author)

  19. Forecasted Flood Depth Grids Providing Early Situational Awareness to FEMA during the 2017 Atlantic Hurricane Season

    Science.gov (United States)

    Jones, M.; Longenecker, H. E., III

    2017-12-01

    The 2017 hurricane season brought the unprecedented landfall of three Category 4 hurricanes (Harvey, Irma and Maria). FEMA is responsible for coordinating the federal response and recovery efforts for large disasters such as these. FEMA depends on timely and accurate depth grids to estimate hazard exposure, model damage assessments, plan flight paths for imagery acquisition, and prioritize response efforts. In order to produce riverine or coastal depth grids based on observed flooding, the methodology requires peak crest water levels at stream gauges, tide gauges, high water marks, and best-available elevation data. Because peak crest data isn't available until the apex of a flooding event and high water marks may take up to several weeks for field teams to collect for a large-scale flooding event, final observed depth grids are not available to FEMA until several days after a flood has begun to subside. Within the last decade NOAA's National Weather Service (NWS) has implemented the Advanced Hydrologic Prediction Service (AHPS), a web-based suite of accurate forecast products that provide hydrograph forecasts at over 3,500 stream gauge locations across the United States. These forecasts have been newly implemented into an automated depth grid script tool, using predicted instead of observed water levels, allowing FEMA access to flood hazard information up to 3 days prior to a flooding event. Water depths are calculated from the AHPS predicted flood stages and are interpolated at 100m spacing along NHD hydrolines within the basin of interest. A water surface elevation raster is generated from these water depths using an Inverse Distance Weighted interpolation. Then, elevation (USGS NED 30m) is subtracted from the water surface elevation raster so that the remaining values represent the depth of predicted flooding above the ground surface. This automated process requires minimal user input and produced forecasted depth grids that were comparable to post

  20. Data and modelling requirements for CO2 inversions using high-frequency data

    International Nuclear Information System (INIS)

    Law, R.M.; Rayner, P.J.; Steele, L.P.; Enting, I.G.

    2003-01-01

    We explore the future possibilities for CO 2 source estimation from atmospheric concentration data by performing synthetic data experiments. Synthetic data are used to test seasonal CO 2 inversions using high-frequency data. Monthly CO 2 sources over the Australian region are calculated for inversions with data at 4-hourly frequency and averaged over 1 d, 2.5 d, 5 d, 12.17 d and 1 month. The inversion quality, as determined by bias and uncertainty, is degraded when averaging over longer periods. This shows the value of the strong but relatively short-lived signals present in high-frequency records that are removed in averaged and particularly filtered records. Sensitivity tests are performed in which the synthetic data are 'corrupted' to simulate systematic measurement errors such as intercalibration differences or to simulate transport modelling errors. The inversion is also used to estimate the effect of calibration offsets between sites. We find that at short data-averaging periods the inversion is reasonably robust to measurement-type errors. For transport-type errors, the best results are achieved for synoptic (2-5 d) timescales. Overall the tests indicate that improved source estimates should be possible by incorporating continuous measurements into CO 2 inversions

  1. Bayesian approach to inverse statistical mechanics

    Science.gov (United States)

    Habeck, Michael

    2014-05-01

    Inverse statistical mechanics aims to determine particle interactions from ensemble properties. This article looks at this inverse problem from a Bayesian perspective and discusses several statistical estimators to solve it. In addition, a sequential Monte Carlo algorithm is proposed that draws the interaction parameters from their posterior probability distribution. The posterior probability involves an intractable partition function that is estimated along with the interactions. The method is illustrated for inverse problems of varying complexity, including the estimation of a temperature, the inverse Ising problem, maximum entropy fitting, and the reconstruction of molecular interaction potentials.

  2. Time-reversal and Bayesian inversion

    Science.gov (United States)

    Debski, Wojciech

    2017-04-01

    Probabilistic inversion technique is superior to the classical optimization-based approach in all but one aspects. It requires quite exhaustive computations which prohibit its use in huge size inverse problems like global seismic tomography or waveform inversion to name a few. The advantages of the approach are, however, so appealing that there is an ongoing continuous afford to make the large inverse task as mentioned above manageable with the probabilistic inverse approach. One of the perspective possibility to achieve this goal relays on exploring the internal symmetry of the seismological modeling problems in hand - a time reversal and reciprocity invariance. This two basic properties of the elastic wave equation when incorporating into the probabilistic inversion schemata open a new horizons for Bayesian inversion. In this presentation we discuss the time reversal symmetry property, its mathematical aspects and propose how to combine it with the probabilistic inverse theory into a compact, fast inversion algorithm. We illustrate the proposed idea with the newly developed location algorithm TRMLOC and discuss its efficiency when applied to mining induced seismic data.

  3. Inverse Kinematics of a Serial Robot

    Directory of Open Access Journals (Sweden)

    Amici Cinzia

    2016-01-01

    Full Text Available This work describes a technique to treat the inverse kinematics of a serial manipulator. The inverse kinematics is obtained through the numerical inversion of the Jacobian matrix, that represents the equation of motion of the manipulator. The inversion is affected by numerical errors and, in different conditions, due to the numerical nature of the solver, it does not converge to a reasonable solution. Thus a soft computing approach is adopted to mix different traditional methods to obtain an increment of algorithmic convergence.

  4. Pre-"peak water" time in the southwest Yukon: when cryospheric changes trigger hydrological regime shifts

    Science.gov (United States)

    Baraer, M.; Chesnokova, A.; Huh, K. I.; Laperriere-Robillard, T.

    2017-12-01

    Saint-Elias Mountains host numerous cryospheric systems such as glaciers, seasonal and perennial snow cover, permafrost, aufeis, and different forms of buried ice. Those systems are very sensitive to climate changes and exhibit ongoing reduction in extent and/or changes in formation/ablation times. Because they highly influence the hydrological regimes of rivers, cryospheric changes raise concerns about consequences for regional water resources and ecosystems. The present study combines historical data analysis and hydrological modeling in order to estimate how cryospheric changes impact hydrological regimes at eight watersheds of different glacier cover (0- 30%) in the southwest Yukon. Methods combine traditional hydrograph analysis techniques and more advance techniques such as Fast Fourier Transform filters used to isolate significant trends in discharge properties from noise or climatic oscillations. Measured trends in discharge variables are connected to cryospheric changes by using a water balance / peak water model (Baraer et al., 2012), here adapted to the main cryospheric systems that characterize the southwest Yukon.Results show three distinct hydrological regimes for (1) non glacierized, (2) glacierized, and (3) major lakes hosting catchments. The studied glacierized catchments have not passed the "peak water" yet and still exhibit increases in yearly and late summer discharges and a decrease in runoff variability. All watersheds show an increase in winter discharge and a snowmelt-driven shift of yearly peak discharge toward earlier in the season. The study suggests that, in a couple of decades, water resources and dependent ecosystems will face the combined effects of (A) a shift in the contribution trend from declining perennial cryospheric systems and (B) continuing alteration of the contribution from the seasonal cryospheric systems.

  5. Peak-valley-peak pattern of histone modifications delineates active regulatory elements and their directionality

    DEFF Research Database (Denmark)

    Pundhir, Sachin; Bagger, Frederik Otzen; Lauridsen, Felicia Kathrine Bratt

    2016-01-01

    Formation of nucleosome free region (NFR) accompanied by specific histone modifications at flanking nucleosomes is an important prerequisite for enhancer and promoter activity. Due to this process, active regulatory elements often exhibit a distinct shape of histone signal in the form of a peak......-valley-peak (PVP) pattern. However, different features of PVP patterns and their robustness in predicting active regulatory elements have never been systematically analyzed. Here, we present PARE, a novel computational method that systematically analyzes the H3K4me1 or H3K4me3 PVP patterns to predict NFRs. We show...... four ENCODE cell lines and four hematopoietic differentiation stages, we identified several enhancers whose regulatory activity is stage specific and correlates positively with the expression of proximal genes in a particular stage. In conclusion, our results demonstrate that PVP patterns delineate...

  6. Seasonal soybean crop reflectance

    Science.gov (United States)

    Lemaster, E. W. (Principal Investigator); Chance, J. E.

    1983-01-01

    Data are presented from field measurements of 1980 including 5 acquisitions of handheld radiometer reflectance measurements, 7 complete sets of parameters for implementing the Suits mode, and other biophysical parameters to characterize the soybean canopy. LANDSAT calculations on the simulated Brazilian soybean reflectance are included along with data collected during the summer and fall on 1981 on soybean single leaf optical parameters for three irrigation treatments. Tests of the Suits vegetative canopy reflectance model for the full hemisphere of observer directions as well as the nadir direction show moderate agreement for the visible channels of the MSS and poor agreement in the near infrared channel. Temporal changes in the spectral characteristics of the single leaves were seen to occur as a function of maturity which demonstrates that the absorptance of a soybean single leaf is more a function of thetransmittancee characteristics than the seasonally consistent single leaf reflectance.

  7. Analysis of a spectrum of a positron annihilation half life through inverse problem studies

    International Nuclear Information System (INIS)

    Monteiro, Roberto Pellacani G.; Viterbo, Vanessa C.; Braga, Joao Pedro; Magalhaes, Wellington F. de; Braga, A.P.

    2002-01-01

    Inversion of positron annihilation lifetime spectroscopy, based on a neural network Hopfield model and singular value decomposition (SVD) associated to Tikhonov regularization is presented in this work. From a previous reported density function for lysozyme in water a simulated spectrum, without spectrometer resolution effects, was generated. The precision of the inverted density function was analyzed taking into account the number of neurons and the learning time of the Hopfield network and the maximum position and areas for the spectral peaks in the SVD method considering noise and noiseless data. A fair agreement was obtained when comparing the inversion results with direct exact results. (author)

  8. STORMVEX: The Storm Peak Lab Cloud Property Validation Experiment Science and Operations Plan

    Energy Technology Data Exchange (ETDEWEB)

    Mace, J; Matrosov, S; Shupe, M; Lawson, P; Hallar, G; McCubbin, I; Marchand, R; Orr, B; Coulter, R; Sedlacek, A; Avallone, L; Long, C

    2010-09-29

    During the Storm Peak Lab Cloud Property Validation Experiment (STORMVEX), a substantial correlative data set of remote sensing observations and direct in situ measurements from fixed and airborne platforms will be created in a winter season, mountainous environment. This will be accomplished by combining mountaintop observations at Storm Peak Laboratory and the airborne National Science Foundation-supported Colorado Airborne Multi-Phase Cloud Study campaign with collocated measurements from the second ARM Mobile Facility (AMF2). We describe in this document the operational plans and motivating science for this experiment, which includes deployment of AMF2 to Steamboat Springs, Colorado. The intensive STORMVEX field phase will begin nominally on 1 November 2010 and extend to approximately early April 2011.

  9. Laterally constrained inversion for CSAMT data interpretation

    Science.gov (United States)

    Wang, Ruo; Yin, Changchun; Wang, Miaoyue; Di, Qingyun

    2015-10-01

    Laterally constrained inversion (LCI) has been successfully applied to the inversion of dc resistivity, TEM and airborne EM data. However, it hasn't been yet applied to the interpretation of controlled-source audio-frequency magnetotelluric (CSAMT) data. In this paper, we apply the LCI method for CSAMT data inversion by preconditioning the Jacobian matrix. We apply a weighting matrix to Jacobian to balance the sensitivity of model parameters, so that the resolution with respect to different model parameters becomes more uniform. Numerical experiments confirm that this can improve the convergence of the inversion. We first invert a synthetic dataset with and without noise to investigate the effect of LCI applications to CSAMT data, for the noise free data, the results show that the LCI method can recover the true model better compared to the traditional single-station inversion; and for the noisy data, the true model is recovered even with a noise level of 8%, indicating that LCI inversions are to some extent noise insensitive. Then, we re-invert two CSAMT datasets collected respectively in a watershed and a coal mine area in Northern China and compare our results with those from previous inversions. The comparison with the previous inversion in a coal mine shows that LCI method delivers smoother layer interfaces that well correlate to seismic data, while comparison with a global searching algorithm of simulated annealing (SA) in a watershed shows that though both methods deliver very similar good results, however, LCI algorithm presented in this paper runs much faster. The inversion results for the coal mine CSAMT survey show that a conductive water-bearing zone that was not revealed by the previous inversions has been identified by the LCI. This further demonstrates that the method presented in this paper works for CSAMT data inversion.

  10. Characteristic of 120 degree C thermoluminescence peak of iceland spar

    International Nuclear Information System (INIS)

    Lu Xinwei; Han Jia

    2006-01-01

    The basic characteristic of 120 degree C thermoluminescence peak of iceland spar was studied. The experimental result indicates the longevity of 120 degree C thermoluminescence peak of iceland spar is about 2 h under 30 degree C. The thermoluminescence peak moves to the high temperature when the heating speed increasing. The intensity of 120 degree C thermoluminescence peak of iceland spar is directly proportional to radiation dose under 15 Gy. (authors)

  11. Global atmospheric carbon budget: results from an ensemble of atmospheric CO2 inversions

    Directory of Open Access Journals (Sweden)

    P. Peylin

    2013-10-01

    Full Text Available Atmospheric CO2 inversions estimate surface carbon fluxes from an optimal fit to atmospheric CO2 measurements, usually including prior constraints on the flux estimates. Eleven sets of carbon flux estimates are compared, generated by different inversions systems that vary in their inversions methods, choice of atmospheric data, transport model and prior information. The inversions were run for at least 5 yr in the period between 1990 and 2010. Mean fluxes for 2001–2004, seasonal cycles, interannual variability and trends are compared for the tropics and northern and southern extra-tropics, and separately for land and ocean. Some continental/basin-scale subdivisions are also considered where the atmospheric network is denser. Four-year mean fluxes are reasonably consistent across inversions at global/latitudinal scale, with a large total (land plus ocean carbon uptake in the north (−3.4 Pg C yr−1 (±0.5 Pg C yr−1 standard deviation, with slightly more uptake over land than over ocean, a significant although more variable source over the tropics (1.6 ± 0.9 Pg C yr−1 and a compensatory sink of similar magnitude in the south (−1.4 ± 0.5 Pg C yr−1 corresponding mainly to an ocean sink. Largest differences across inversions occur in the balance between tropical land sources and southern land sinks. Interannual variability (IAV in carbon fluxes is larger for land than ocean regions (standard deviation around 1.06 versus 0.33 Pg C yr−1 for the 1996–2007 period, with much higher consistency among the inversions for the land. While the tropical land explains most of the IAV (standard deviation ~ 0.65 Pg C yr−1, the northern and southern land also contribute (standard deviation ~ 0.39 Pg C yr−1. Most inversions tend to indicate an increase of the northern land carbon uptake from late 1990s to 2008 (around 0.1 Pg C yr−1, predominantly in North Asia. The mean seasonal cycle appears to be well constrained by the atmospheric data over

  12. Assessing peak aerobic capacity in Dutch law enforcement officers

    NARCIS (Netherlands)

    Wittink, Harriet; Takken, Tim; de Groot, Janke; Reneman, Michiel; Peters, Roelof; Vanhees, Luc

    2015-01-01

    Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report

  13. Determination of the upper limit of a peak area

    International Nuclear Information System (INIS)

    Helene, O.

    1990-03-01

    This paper reports the procedure to extract an upper limit of a peak area in a multichannel spectrum. This procedure takes into account the finite shape of the peak and the uncertanties in the background and in the expected position of the peak. (author) [pt

  14. PEAK TRACKING WITH A NEURAL NETWORK FOR SPECTRAL RECOGNITION

    NARCIS (Netherlands)

    COENEGRACHT, PMJ; METTING, HJ; VANLOO, EM; SNOEIJER, GJ; DOORNBOS, DA

    1993-01-01

    A peak tracking method based on a simulated feed-forward neural network with back-propagation is presented. The network uses the normalized UV spectra and peak areas measured in one chromatogram for peak recognition. It suffices to train the network with only one set of spectra recorded in one

  15. Assessing peak aerobic capacity in Dutch law enforcement officers.

    NARCIS (Netherlands)

    Wittink, H.; Takken, T.; Groot, J.F. de; Reneman, M.; Peters, R.; Vanhees, L.

    2015-01-01

    Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report

  16. 7 CFR 457.163 - Nursery peak inventory endorsement.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Nursery peak inventory endorsement. 457.163 Section... CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.163 Nursery peak inventory endorsement. Nursery Crop Insurance Peak Inventory Endorsement This endorsement is not continuous and must be...

  17. Bayesian approach for peak detection in two-dimensional chromatography

    NARCIS (Netherlands)

    Vivó-Truyols, G.

    2012-01-01

    A new method for peak detection in two-dimensional chromatography is presented. In a first step, the method starts with a conventional one-dimensional peak detection algorithm to detect modulated peaks. In a second step, a sophisticated algorithm is constructed to decide which of the individual

  18. Determination of the upper limit of a peak area

    International Nuclear Information System (INIS)

    Helene, O.

    1991-01-01

    This article reports the procedure to extract an upper limit of a peak area in a multichannel spectrum. This procedure takes into account the finite shape of the peak and the uncertainties both in the background and in the expected position of the peak. (orig.)

  19. Assessment of end-use electricity consumption and peak demand by Townsville's housing stock

    International Nuclear Information System (INIS)

    Ren, Zhengen; Paevere, Phillip; Grozev, George; Egan, Stephen; Anticev, Julia

    2013-01-01

    We have developed a comprehensive model to estimate annual end-use electricity consumption and peak demand of housing stock, considering occupants' use of air conditioning systems and major appliances. The model was applied to analyse private dwellings in Townsville, Australia's largest tropical city. For the financial year (FY) 2010–11 the predicted results agreed with the actual electricity consumption with an error less than 10% for cooling thermostat settings at the standard setting temperature of 26.5 °C and at 1.0 °C higher than the standard setting. The greatest difference in monthly electricity consumption in the summer season between the model and the actual data decreased from 21% to 2% when the thermostat setting was changed from 26.5 °C to 27.5 °C. Our findings also showed that installation of solar panels in Townville houses could reduce electricity demand from the grid and would have a minor impact on the yearly peak demand. A key new feature of the model is that it can be used to predict probability distribution of energy demand considering (a) that appliances may be used randomly and (b) the way people use thermostats. The peak demand for the FY estimated from the probability distribution tracked the actual peak demand at 97% confidence level. - Highlights: • We developed a model to estimate housing stock energy consumption and peak demand. • Appliances used randomly and thermostat settings for space cooling were considered. • On-site installation of solar panels was also considered. • Its' results agree well with the actual electricity consumption and peak demand. • It shows the model could provide the probability distribution of electricity demand

  20. Empirical model for the electron density peak height disturbance in response to solar wind conditions

    Science.gov (United States)

    Blanch, E.; Altadill, D.

    2009-04-01

    Geomagnetic storms disturb the quiet behaviour of the ionosphere, its electron density and the electron density peak height, hmF2. Many works have been done to predict the variations of the electron density but few efforts have been dedicated to predict the variations the hmF2 under disturbed helio-geomagnetic conditions. We present the results of the analyses of the F2 layer peak height disturbances occurred during intense geomagnetic storms for one solar cycle. The results systematically show a significant peak height increase about 2 hours after the beginning of the main phase of the geomagnetic storm, independently of both the local time position of the station at the onset of the storm and the intensity of the storm. An additional uplift is observed in the post sunset sector. The duration of the uplift and the height increase are dependent of the intensity of the geomagnetic storm, the season and the local time position of the station at the onset of the storm. An empirical model has been developed to predict the electron density peak height disturbances in response to solar wind conditions and local time which can be used for nowcasting and forecasting the hmF2 disturbances for the middle latitude ionosphere. This being an important output for EURIPOS project operational purposes.

  1. Inverse problem in radionuclide transport

    International Nuclear Information System (INIS)

    Yu, C.

    1988-01-01

    The disposal of radioactive waste must comply with the performance objectives set forth in 10 CFR 61 for low-level waste (LLW) and 10 CFR 60 for high-level waste (HLW). To determine probable compliance, the proposed disposal system can be modeled to predict its performance. One of the difficulties encountered in such a study is modeling the migration of radionuclides through a complex geologic medium for the long term. Although many radionuclide transport models exist in the literature, the accuracy of the model prediction is highly dependent on the model parameters used. The problem of using known parameters in a radionuclide transport model to predict radionuclide concentrations is a direct problem (DP); whereas the reverse of DP, i.e., the parameter identification problem of determining model parameters from known radionuclide concentrations, is called the inverse problem (IP). In this study, a procedure to solve IP is tested, using the regression technique. Several nonlinear regression programs are examined, and the best one is recommended. 13 refs., 1 tab

  2. Inversion based on computational simulations

    International Nuclear Information System (INIS)

    Hanson, K.M.; Cunningham, G.S.; Saquib, S.S.

    1998-01-01

    A standard approach to solving inversion problems that involve many parameters uses gradient-based optimization to find the parameters that best match the data. The authors discuss enabling techniques that facilitate application of this approach to large-scale computational simulations, which are the only way to investigate many complex physical phenomena. Such simulations may not seem to lend themselves to calculation of the gradient with respect to numerous parameters. However, adjoint differentiation allows one to efficiently compute the gradient of an objective function with respect to all the variables of a simulation. When combined with advanced gradient-based optimization algorithms, adjoint differentiation permits one to solve very large problems of optimization or parameter estimation. These techniques will be illustrated through the simulation of the time-dependent diffusion of infrared light through tissue, which has been used to perform optical tomography. The techniques discussed have a wide range of applicability to modeling including the optimization of models to achieve a desired design goal

  3. MODEL SELECTION FOR SPECTROPOLARIMETRIC INVERSIONS

    International Nuclear Information System (INIS)

    Asensio Ramos, A.; Manso Sainz, R.; Martínez González, M. J.; Socas-Navarro, H.; Viticchié, B.; Orozco Suárez, D.

    2012-01-01

    Inferring magnetic and thermodynamic information from spectropolarimetric observations relies on the assumption of a parameterized model atmosphere whose parameters are tuned by comparison with observations. Often, the choice of the underlying atmospheric model is based on subjective reasons. In other cases, complex models are chosen based on objective reasons (for instance, the necessity to explain asymmetries in the Stokes profiles) but it is not clear what degree of complexity is needed. The lack of an objective way of comparing models has, sometimes, led to opposing views of the solar magnetism because the inferred physical scenarios are essentially different. We present the first quantitative model comparison based on the computation of the Bayesian evidence ratios for spectropolarimetric observations. Our results show that there is not a single model appropriate for all profiles simultaneously. Data with moderate signal-to-noise ratios (S/Ns) favor models without gradients along the line of sight. If the observations show clear circular and linear polarization signals above the noise level, models with gradients along the line are preferred. As a general rule, observations with large S/Ns favor more complex models. We demonstrate that the evidence ratios correlate well with simple proxies. Therefore, we propose to calculate these proxies when carrying out standard least-squares inversions to allow for model comparison in the future.

  4. Inverse transport theory of photoacoustics

    International Nuclear Information System (INIS)

    Bal, Guillaume; Jollivet, Alexandre; Jugnon, Vincent

    2010-01-01

    We consider the reconstruction of optical parameters in a domain of interest from photoacoustic data. Photoacoustic tomography (PAT) radiates high-frequency electromagnetic waves into the domain and measures acoustic signals emitted by the resulting thermal expansion. Acoustic signals are then used to construct the deposited thermal energy map. The latter depends on the constitutive optical parameters in a nontrivial manner. In this paper, we develop and use an inverse transport theory with internal measurements to extract information on the optical coefficients from knowledge of the deposited thermal energy map. We consider the multi-measurement setting in which many electromagnetic radiation patterns are used to probe the domain of interest. By developing an expansion of the measurement operator into singular components, we show that the spatial variations of the intrinsic attenuation and the scattering coefficients may be reconstructed. We also reconstruct coefficients describing anisotropic scattering of photons, such as the anisotropy coefficient g(x) in a Henyey–Greenstein phase function model. Finally, we derive stability estimates for the reconstructions

  5. Inverse Problems and Uncertainty Quantification

    KAUST Repository

    Litvinenko, Alexander

    2014-01-06

    In a Bayesian setting, inverse problems and uncertainty quantification (UQ) - the propagation of uncertainty through a computational (forward) modelare strongly connected. In the form of conditional expectation the Bayesian update becomes computationally attractive. This is especially the case as together with a functional or spectral approach for the forward UQ there is no need for time- consuming and slowly convergent Monte Carlo sampling. The developed sampling- free non-linear Bayesian update is derived from the variational problem associated with conditional expectation. This formulation in general calls for further discretisa- tion to make the computation possible, and we choose a polynomial approximation. After giving details on the actual computation in the framework of functional or spectral approximations, we demonstrate the workings of the algorithm on a number of examples of increasing complexity. At last, we compare the linear and quadratic Bayesian update on the small but taxing example of the chaotic Lorenz 84 model, where we experiment with the influence of different observation or measurement operators on the update.

  6. Inverse Problems and Uncertainty Quantification

    KAUST Repository

    Litvinenko, Alexander; Matthies, Hermann G.

    2014-01-01

    In a Bayesian setting, inverse problems and uncertainty quantification (UQ) - the propagation of uncertainty through a computational (forward) modelare strongly connected. In the form of conditional expectation the Bayesian update becomes computationally attractive. This is especially the case as together with a functional or spectral approach for the forward UQ there is no need for time- consuming and slowly convergent Monte Carlo sampling. The developed sampling- free non-linear Bayesian update is derived from the variational problem associated with conditional expectation. This formulation in general calls for further discretisa- tion to make the computation possible, and we choose a polynomial approximation. After giving details on the actual computation in the framework of functional or spectral approximations, we demonstrate the workings of the algorithm on a number of examples of increasing complexity. At last, we compare the linear and quadratic Bayesian update on the small but taxing example of the chaotic Lorenz 84 model, where we experiment with the influence of different observation or measurement operators on the update.

  7. Inverse Free Electron Laser accelerator

    International Nuclear Information System (INIS)

    Fisher, A.; Gallardo, J.; van Steenbergen, A.; Sandweiss, J.

    1992-09-01

    The study of the INVERSE FREE ELECTRON LASER, as a potential mode of electron acceleration, is being pursued at Brookhaven National Laboratory. Recent studies have focussed on the development of a low energy, high gradient, multi stage linear accelerator. The elementary ingredients for the IFEL interaction are the 50 MeV Linac e - beam and the 10 11 Watt CO 2 laser beam of BNL's Accelerator Test Facility (ATF), Center for Accelerator Physics (CAP) and a wiggler. The latter element is designed as a fast excitation unit making use of alternating stacks of Vanadium Permendur (VaP) ferromagnetic laminations, periodically interspersed with conductive, nonmagnetic laminations, which act as eddy current induced field reflectors. Wiggler parameters and field distribution data will be presented for a prototype wiggler in a constant period and in a ∼ 1.5 %/cm tapered period configuration. The CO 2 laser beam will be transported through the IFEL interaction region by means of a low loss, dielectric coated, rectangular waveguide. Short waveguide test sections have been constructed and have been tested using a low power cw CO 2 laser. Preliminary results of guide attenuation and mode selectivity will be given, together with a discussion of the optical issues for the IFEL accelerator. The IFEL design is supported by the development and use of 1D and 3D simulation programs. The results of simulation computations, including also wiggler errors, for a single module accelerator and for a multi-module accelerator will be presented

  8. Inverse problems and uncertainty quantification

    KAUST Repository

    Litvinenko, Alexander

    2013-12-18

    In a Bayesian setting, inverse problems and uncertainty quantification (UQ)— the propagation of uncertainty through a computational (forward) model—are strongly connected. In the form of conditional expectation the Bayesian update becomes computationally attractive. This is especially the case as together with a functional or spectral approach for the forward UQ there is no need for time- consuming and slowly convergent Monte Carlo sampling. The developed sampling- free non-linear Bayesian update is derived from the variational problem associated with conditional expectation. This formulation in general calls for further discretisa- tion to make the computation possible, and we choose a polynomial approximation. After giving details on the actual computation in the framework of functional or spectral approximations, we demonstrate the workings of the algorithm on a number of examples of increasing complexity. At last, we compare the linear and quadratic Bayesian update on the small but taxing example of the chaotic Lorenz 84 model, where we experiment with the influence of different observation or measurement operators on the update.

  9. Third Harmonic Imaging using a Pulse Inversion

    DEFF Research Database (Denmark)

    Rasmussen, Joachim; Du, Yigang; Jensen, Jørgen Arendt

    2011-01-01

    The pulse inversion (PI) technique can be utilized to separate and enhance harmonic components of a waveform for tissue harmonic imaging. While most ultrasound systems can perform pulse inversion, only few image the 3rd harmonic component. PI pulse subtraction can isolate and enhance the 3rd...

  10. Resolution analysis in full waveform inversion

    NARCIS (Netherlands)

    Fichtner, A.; Trampert, J.

    2011-01-01

    We propose a new method for the quantitative resolution analysis in full seismic waveform inversion that overcomes the limitations of classical synthetic inversions while being computationally more efficient and applicable to any misfit measure. The method rests on (1) the local quadratic

  11. Abel inverse transformation applied to plasma diagnostics

    International Nuclear Information System (INIS)

    Zhu Shiyao

    1987-01-01

    Two methods of Abel inverse transformation are applied to two different test profiles. The effects of random errors of input data, position uncertainty and number of points of input data on the accuracy of inverse transformation have been studied. The two methods are compared in each other

  12. Global Seasonality of Rotavirus Disease

    Science.gov (United States)

    Patel, Manish M.; Pitzer, Virginia; Alonso, Wladimir J.; Vera, David; Lopman, Ben; Tate, Jacqueline; Viboud, Cecile; Parashar, Umesh D.

    2012-01-01

    Background A substantial number of surveillance studies have documented rotavirus prevalence among children admitted for dehydrating diarrhea. We sought to establish global seasonal patterns of rotavirus disease before widespread vaccine introduction. Methods We reviewed studies of rotavirus detection in children with diarrhea published since 1995. We assessed potential relationships between seasonal prevalence and locality by plotting the average monthly proportion of diarrhea cases positive for rotavirus according to geography, country development, and latitude. We used linear regression to identify variables that were potentially associated with the seasonal intensity of rotavirus. Results Among a total of 99 studies representing all six geographical regions of the world, patterns of year-round disease were more evident in low- and low-middle income countries compared with upper-middle and high income countries where disease was more likely to be seasonal. The level of country development was a stronger predictor of strength of seasonality (P=0.001) than geographical location or climate. However, the observation of distinctly different seasonal patterns of rotavirus disease in some countries with similar geographical location, climate and level of development indicate that a single unifying explanation for variation in seasonality of rotavirus disease is unlikely. Conclusion While no unifying explanation emerged for varying rotavirus seasonality globally, the country income level was somewhat more predictive of the likelihood of having seasonal disease than other factors. Future evaluation of the effect of rotavirus vaccination on seasonal patterns of disease in different settings may help understand factors that drive the global seasonality of rotavirus disease. PMID:23190782

  13. Seasonality of alcohol-related phenomena in Estonia

    Science.gov (United States)

    Silm, Siiri; Ahas, Rein

    2005-03-01

    We studied alcohol consumption and its consequences as a seasonal phenomenon in Estonia and analysed the social and environmental factors that may cause its seasonal rhythm. There are two important questions when researching the seasonality of human activities: (1) whether it is caused by natural or social factors, and (2) whether the impact of the factors is direct or indirect. Often the seasonality of social phenomena is caused by social factors, but the triggering mechanisms are related to environmental factors like temperature, precipitation, and radiation via the circannual calendar. The indicators of alcohol consumption in the current paper are grouped as: (1) pre-consumption phenomena, i.e. production, tax and excise, sales (beer, wine and vodka are analysed separately), and (2) post-consumption phenomena, i.e. alcohol-related crime and traffic accidents and the number of people detained in lockups and admitted to alcohol treatment clinics. In addition, seasonal variability in the amount of alcohol advertising has been studied, and a survey has been carried out among 87 students of Tartu University. The analysis shows that different phenomena related to alcohol have a clear seasonal rhythm in Estonia. The peak period of phenomena related to beer is in the summer, from June to August and the low point is during the first months of the year. Beer consumption correlates well with air temperature. The consumption of vodka increases sharply at the end of the year and in June; the production of vodka does not have a significant correlation with negative temperatures. The consumption of wine increases during summer and in December. The consequences of alcohol consumption, expressed as the rate of traffic accidents or the frequency of medical treatment, also show seasonal variability. Seasonal variability of alcohol consumption in Estonia is influenced by natural factors (temperature, humidity, etc.) and by social factors (celebrations, vacations, etc.). However

  14. Peak-by-peak correction of Ge(Li) gamma-ray spectra for photopeaks from background

    International Nuclear Information System (INIS)

    Cutshall, N.H.; Larsen, I.L.

    1980-01-01

    Background photopeaks can interfere with accurate measurement of low levels of radionuclides by gamma-ray spectrometry. A flowchart for peak-by-peak correction of sample spectra to produce accurate results is presented. (orig.)

  15. Peak-by-peak correction of Ge(Li) gamma-ray spectra for photopeaks from background

    Energy Technology Data Exchange (ETDEWEB)

    Cutshall, N H; Larsen, I L [Oak Ridge National Lab., TN (USA)

    1980-12-01

    Background photopeaks can interfere with accurate measurement of low levels of radionuclides by gamma-ray spectrometry. A flowchart for peak-by-peak correction of sample spectra to produce accurate results is presented.

  16. Forward modeling. Route to electromagnetic inversion

    Energy Technology Data Exchange (ETDEWEB)

    Groom, R; Walker, P [PetRos EiKon Incorporated, Ontario (Canada)

    1996-05-01

    Inversion of electromagnetic data is a topical subject in the literature, and much time has been devoted to understanding the convergence properties of various inverse methods. The relative lack of success of electromagnetic inversion techniques is partly attributable to the difficulties in the kernel forward modeling software. These difficulties come in two broad classes: (1) Completeness and robustness, and (2) convergence, execution time and model simplicity. If such problems exist in the forward modeling kernel, it was demonstrated that inversion can fail to generate reasonable results. It was suggested that classical inversion techniques, which are based on minimizing a norm of the error between data and the simulated data, will only be successful when these difficulties in forward modeling kernels are properly dealt with. 4 refs., 5 figs.

  17. Stochastic Gabor reflectivity and acoustic impedance inversion

    Science.gov (United States)

    Hariri Naghadeh, Diako; Morley, Christopher Keith; Ferguson, Angus John

    2018-02-01

    To delineate subsurface lithology to estimate petrophysical properties of a reservoir, it is possible to use acoustic impedance (AI) which is the result of seismic inversion. To change amplitude to AI, removal of wavelet effects from the seismic signal in order to get a reflection series, and subsequently transforming those reflections to AI, is vital. To carry out seismic inversion correctly it is important to not assume that the seismic signal is stationary. However, all stationary deconvolution methods are designed following that assumption. To increase temporal resolution and interpretation ability, amplitude compensation and phase correction are inevitable. Those are pitfalls of stationary reflectivity inversion. Although stationary reflectivity inversion methods are trying to estimate reflectivity series, because of incorrect assumptions their estimations will not be correct, but may be useful. Trying to convert those reflection series to AI, also merging with the low frequency initial model, can help us. The aim of this study was to apply non-stationary deconvolution to eliminate time variant wavelet effects from the signal and to convert the estimated reflection series to the absolute AI by getting bias from well logs. To carry out this aim, stochastic Gabor inversion in the time domain was used. The Gabor transform derived the signal’s time-frequency analysis and estimated wavelet properties from different windows. Dealing with different time windows gave an ability to create a time-variant kernel matrix, which was used to remove matrix effects from seismic data. The result was a reflection series that does not follow the stationary assumption. The subsequent step was to convert those reflections to AI using well information. Synthetic and real data sets were used to show the ability of the introduced method. The results highlight that the time cost to get seismic inversion is negligible related to general Gabor inversion in the frequency domain. Also

  18. Inverse m-matrices and ultrametric matrices

    CERN Document Server

    Dellacherie, Claude; San Martin, Jaime

    2014-01-01

    The study of M-matrices, their inverses and discrete potential theory is now a well-established part of linear algebra and the theory of Markov chains. The main focus of this monograph is the so-called inverse M-matrix problem, which asks for a characterization of nonnegative matrices whose inverses are M-matrices. We present an answer in terms of discrete potential theory based on the Choquet-Deny Theorem. A distinguished subclass of inverse M-matrices is ultrametric matrices, which are important in applications such as taxonomy. Ultrametricity is revealed to be a relevant concept in linear algebra and discrete potential theory because of its relation with trees in graph theory and mean expected value matrices in probability theory. Remarkable properties of Hadamard functions and products for the class of inverse M-matrices are developed and probabilistic insights are provided throughout the monograph.

  19. Recurrent Neural Network for Computing Outer Inverse.

    Science.gov (United States)

    Živković, Ivan S; Stanimirović, Predrag S; Wei, Yimin

    2016-05-01

    Two linear recurrent neural networks for generating outer inverses with prescribed range and null space are defined. Each of the proposed recurrent neural networks is based on the matrix-valued differential equation, a generalization of dynamic equations proposed earlier for the nonsingular matrix inversion, the Moore-Penrose inversion, as well as the Drazin inversion, under the condition of zero initial state. The application of the first approach is conditioned by the properties of the spectrum of a certain matrix; the second approach eliminates this drawback, though at the cost of increasing the number of matrix operations. The cases corresponding to the most common generalized inverses are defined. The conditions that ensure stability of the proposed neural network are presented. Illustrative examples present the results of numerical simulations.

  20. Fast wavelet based sparse approximate inverse preconditioner

    Energy Technology Data Exchange (ETDEWEB)

    Wan, W.L. [Univ. of California, Los Angeles, CA (United States)

    1996-12-31

    Incomplete LU factorization is a robust preconditioner for both general and PDE problems but unfortunately not easy to parallelize. Recent study of Huckle and Grote and Chow and Saad showed that sparse approximate inverse could be a potential alternative while readily parallelizable. However, for special class of matrix A that comes from elliptic PDE problems, their preconditioners are not optimal in the sense that independent of mesh size. A reason may be that no good sparse approximate inverse exists for the dense inverse matrix. Our observation is that for this kind of matrices, its inverse entries typically have piecewise smooth changes. We can take advantage of this fact and use wavelet compression techniques to construct a better sparse approximate inverse preconditioner. We shall show numerically that our approach is effective for this kind of matrices.

  1. Regional-seasonal weather forecasting

    Energy Technology Data Exchange (ETDEWEB)

    Abarbanel, H.; Foley, H.; MacDonald, G.; Rothaus, O.; Rudermann, M.; Vesecky, J.

    1980-08-01

    In the interest of allocating heating fuels optimally, the state-of-the-art for seasonal weather forecasting is reviewed. A model using an enormous data base of past weather data is contemplated to improve seasonal forecasts, but present skills do not make that practicable. 90 references. (PSB)

  2. Developments in inverse photoemission spectroscopy

    International Nuclear Information System (INIS)

    Sheils, W.; Leckey, R.C.G.; Riley, J.D.

    1996-01-01

    In the 1950's and 1960's, Photoemission Spectroscopy (PES) established itself as the major technique for the study of the occupied electronic energy levels of solids. During this period the field divided into two branches: X-ray Photoemission Spectroscopy (XPS) for photon energies greater than ∼l000eV, and Ultra-violet Photoemission Spectroscopy (UPS) for photon energies below ∼100eV. By the 1970's XPS and UPS had become mature techniques. Like XPS, BIS (at x-ray energies) does not have the momentum-resolving ability of UPS that has contributed much to the understanding of the occupied band structures of solids. BIS moved into a new energy regime in 1977 when Dose employed a Geiger-Mueller tube to obtain density of unoccupied states data from a tantalum sample at a photon energy of ∼9.7eV. At similar energies, the technique has since become known as Inverse Photoemission Spectroscopy (IPS), in acknowledgment of its complementary relationship to UPS and to distinguish it from the higher energy BIS. Drawing on decades of UPS expertise, IPS has quickly moved into areas of interest where UPS has been applied; metals, semiconductors, layer compounds, adsorbates, ferromagnets, and superconductors. At La Trobe University an IPS facility has been constructed. This presentation reports on developments in the experimental and analytical techniques of IPS that have been made there. The results of a study of the unoccupied bulk and surface bands of GaAs are presented

  3. Automatic Peak Selection by a Benjamini-Hochberg-Based Algorithm

    KAUST Repository

    Abbas, Ahmed; Kong, Xin-Bing; Liu, Zhi; Jing, Bing-Yi; Gao, Xin

    2013-01-01

    A common issue in bioinformatics is that computational methods often generate a large number of predictions sorted according to certain confidence scores. A key problem is then determining how many predictions must be selected to include most of the true predictions while maintaining reasonably high precision. In nuclear magnetic resonance (NMR)-based protein structure determination, for instance, computational peak picking methods are becoming more and more common, although expert-knowledge remains the method of choice to determine how many peaks among thousands of candidate peaks should be taken into consideration to capture the true peaks. Here, we propose a Benjamini-Hochberg (B-H)-based approach that automatically selects the number of peaks. We formulate the peak selection problem as a multiple testing problem. Given a candidate peak list sorted by either volumes or intensities, we first convert the peaks into p-values and then apply the B-H-based algorithm to automatically select the number of peaks. The proposed approach is tested on the state-of-the-art peak picking methods, including WaVPeak [1] and PICKY [2]. Compared with the traditional fixed number-based approach, our approach returns significantly more true peaks. For instance, by combining WaVPeak or PICKY with the proposed method, the missing peak rates are on average reduced by 20% and 26%, respectively, in a benchmark set of 32 spectra extracted from eight proteins. The consensus of the B-H-selected peaks from both WaVPeak and PICKY achieves 88% recall and 83% precision, which significantly outperforms each individual method and the consensus method without using the B-H algorithm. The proposed method can be used as a standard procedure for any peak picking method and straightforwardly applied to some other prediction selection problems in bioinformatics. The source code, documentation and example data of the proposed method is available at http://sfb.kaust.edu.sa/pages/software.aspx. © 2013

  4. Automatic Peak Selection by a Benjamini-Hochberg-Based Algorithm

    KAUST Repository

    Abbas, Ahmed

    2013-01-07

    A common issue in bioinformatics is that computational methods often generate a large number of predictions sorted according to certain confidence scores. A key problem is then determining how many predictions must be selected to include most of the true predictions while maintaining reasonably high precision. In nuclear magnetic resonance (NMR)-based protein structure determination, for instance, computational peak picking methods are becoming more and more common, although expert-knowledge remains the method of choice to determine how many peaks among thousands of candidate peaks should be taken into consideration to capture the true peaks. Here, we propose a Benjamini-Hochberg (B-H)-based approach that automatically selects the number of peaks. We formulate the peak selection problem as a multiple testing problem. Given a candidate peak list sorted by either volumes or intensities, we first convert the peaks into p-values and then apply the B-H-based algorithm to automatically select the number of peaks. The proposed approach is tested on the state-of-the-art peak picking methods, including WaVPeak [1] and PICKY [2]. Compared with the traditional fixed number-based approach, our approach returns significantly more true peaks. For instance, by combining WaVPeak or PICKY with the proposed method, the missing peak rates are on average reduced by 20% and 26%, respectively, in a benchmark set of 32 spectra extracted from eight proteins. The consensus of the B-H-selected peaks from both WaVPeak and PICKY achieves 88% recall and 83% precision, which significantly outperforms each individual method and the consensus method without using the B-H algorithm. The proposed method can be used as a standard procedure for any peak picking method and straightforwardly applied to some other prediction selection problems in bioinformatics. The source code, documentation and example data of the proposed method is available at http://sfb.kaust.edu.sa/pages/software.aspx. © 2013

  5. Simulation of atmospheric temperature inversions over greater cairo using the MM5 Meso-Scale atmospheric model

    International Nuclear Information System (INIS)

    Kandil, H.A.; Elhadidi, B.M.; Kader, A. A.; Moaty, A.A.; Sherif, A.O.

    2006-01-01

    Air pollution episodes have been recorded in Cairo, during the fall season, since 1999, as a result of specific meteorological conditions combined with large quantity of pollutants created by several ground-based sources. The main reason for the smog-like episodes (black clouds) is adverse weather conditions with low and variable winds, high humidity and strong temperature inversions in the few-hundred meters above the ground. The two important types of temperature inversion affecting the air pollution are surface or ground (radiation) inversion and subsidence (elevated) inversion. The surface temperature inversion is associated with a rapid decrease in the ground surface temperature with the simultaneous existence of warm air in the lower troposphere. The inversion develops at dusk and continues until the surface warms again the following day. Pollutants emitted during the night are caught under this i nversion lid. S ubsidence inversion forms when warm air masses move over colder air masses. The inversion develops with a stagnating high-pressure system (generally associated with fair weather). Under these conditions, the pressure gradient becomes progressively weaker so that winds become light. These light winds greatly reduce the horizontal transport and dispersion of pollutants. At the same time, the subsidence inversion acts as a barrier to the vertical dispersion of the pollutants. In this study, the Penn State/NCAR meso -scale model (MM5) is used to simulate the temperature inversion phenomenon over Greater Cairo region during the fall season of 2004. Accurate computations of the heat transfer at the surface are needed to capture this phenomenon. This can only be achieved by high-resolution simulations in both horizontal and vertical directions. Hence, for accurate simulation of the temperature inversion over Greater Cairo, four nested domains of resolutions of 27 km, 9 km, 3 km and 1 km, respectively, were used in the horizontal planes. Furthermore, 42

  6. Statistical Short-Range Guidance for Peak Wind Speed Forecasts on Kennedy Space Center/Cape Canaveral Air Force Station: Phase I Results

    Science.gov (United States)

    Lambert, Winifred C.; Merceret, Francis J. (Technical Monitor)

    2002-01-01

    This report describes the results of the ANU's (Applied Meteorology Unit) Short-Range Statistical Forecasting task for peak winds. The peak wind speeds are an important forecast element for the Space Shuttle and Expendable Launch Vehicle programs. The Keith Weather Squadron and the Spaceflight Meteorology Group indicate that peak winds are challenging to forecast. The Applied Meteorology Unit was tasked to develop tools that aid in short-range forecasts of peak winds at tower sites of operational interest. A 7 year record of wind tower data was used in the analysis. Hourly and directional climatologies by tower and month were developed to determine the seasonal behavior of the average and peak winds. In all climatologies, the average and peak wind speeds were highly variable in time. This indicated that the development of a peak wind forecasting tool would be difficult. Probability density functions (PDF) of peak wind speed were calculated to determine the distribution of peak speed with average speed. These provide forecasters with a means of determining the probability of meeting or exceeding a certain peak wind given an observed or forecast average speed. The climatologies and PDFs provide tools with which to make peak wind forecasts that are critical to safe operations.

  7. Identification of polymorphic inversions from genotypes

    Directory of Open Access Journals (Sweden)

    Cáceres Alejandro

    2012-02-01

    Full Text Available Abstract Background Polymorphic inversions are a source of genetic variability with a direct impact on recombination frequencies. Given the difficulty of their experimental study, computational methods have been developed to infer their existence in a large number of individuals using genome-wide data of nucleotide variation. Methods based on haplotype tagging of known inversions attempt to classify individuals as having a normal or inverted allele. Other methods that measure differences between linkage disequilibrium attempt to identify regions with inversions but unable to classify subjects accurately, an essential requirement for association studies. Results We present a novel method to both identify polymorphic inversions from genome-wide genotype data and classify individuals as containing a normal or inverted allele. Our method, a generalization of a published method for haplotype data 1, utilizes linkage between groups of SNPs to partition a set of individuals into normal and inverted subpopulations. We employ a sliding window scan to identify regions likely to have an inversion, and accumulation of evidence from neighboring SNPs is used to accurately determine the inversion status of each subject. Further, our approach detects inversions directly from genotype data, thus increasing its usability to current genome-wide association studies (GWAS. Conclusions We demonstrate the accuracy of our method to detect inversions and classify individuals on principled-simulated genotypes, produced by the evolution of an inversion event within a coalescent model 2. We applied our method to real genotype data from HapMap Phase III to characterize the inversion status of two known inversions within the regions 17q21 and 8p23 across 1184 individuals. Finally, we scan the full genomes of the European Origin (CEU and Yoruba (YRI HapMap samples. We find population-based evidence for 9 out of 15 well-established autosomic inversions, and for 52 regions

  8. Seasonal trends in sleep-disordered breathing: evidence from Internet search engine query data.

    Science.gov (United States)

    Ingram, David G; Matthews, Camilla K; Plante, David T

    2015-03-01

    The primary aim of the current study was to test the hypothesis that there is a seasonal component to snoring and obstructive sleep apnea (OSA) through the use of Google search engine query data. Internet search engine query data were retrieved from Google Trends from January 2006 to December 2012. Monthly normalized search volume was obtained over that 7-year period in the USA and Australia for the following search terms: "snoring" and "sleep apnea". Seasonal effects were investigated by fitting cosinor regression models. In addition, the search terms "snoring children" and "sleep apnea children" were evaluated to examine seasonal effects in pediatric populations. Statistically significant seasonal effects were found using cosinor analysis in both USA and Australia for "snoring" (p search term in Australia (p = 0.13). Seasonal patterns for "snoring children" and "sleep apnea children" were observed in the USA (p = 0.002 and p search volume to examine these search terms in Australia. All searches peaked in the winter or early spring in both countries, with the magnitude of seasonal effect ranging from 5 to 50 %. Our findings indicate that there are significant seasonal trends for both snoring and sleep apnea internet search engine queries, with a peak in the winter and early spring. Further research is indicated to determine the mechanisms underlying these findings, whether they have clinical impact, and if they are associated with other comorbid medical conditions that have similar patterns of seasonal exacerbation.

  9. Radiation Source Mapping with Bayesian Inverse Methods

    Science.gov (United States)

    Hykes, Joshua Michael

    We present a method to map the spectral and spatial distributions of radioactive sources using a small number of detectors. Locating and identifying radioactive materials is important for border monitoring, accounting for special nuclear material in processing facilities, and in clean-up operations. Most methods to analyze these problems make restrictive assumptions about the distribution of the source. In contrast, the source-mapping method presented here allows an arbitrary three-dimensional distribution in space and a flexible group and gamma peak distribution in energy. To apply the method, the system's geometry and materials must be known. A probabilistic Bayesian approach is used to solve the resulting inverse problem (IP) since the system of equations is ill-posed. The probabilistic approach also provides estimates of the confidence in the final source map prediction. A set of adjoint flux, discrete ordinates solutions, obtained in this work by the Denovo code, are required to efficiently compute detector responses from a candidate source distribution. These adjoint fluxes are then used to form the linear model to map the state space to the response space. The test for the method is simultaneously locating a set of 137Cs and 60Co gamma sources in an empty room. This test problem is solved using synthetic measurements generated by a Monte Carlo (MCNP) model and using experimental measurements that we collected for this purpose. With the synthetic data, the predicted source distributions identified the locations of the sources to within tens of centimeters, in a room with an approximately four-by-four meter floor plan. Most of the predicted source intensities were within a factor of ten of their true value. The chi-square value of the predicted source was within a factor of five from the expected value based on the number of measurements employed. With a favorable uniform initial guess, the predicted source map was nearly identical to the true distribution

  10. A Joint Method of Envelope Inversion Combined with Hybrid-domain Full Waveform Inversion

    Science.gov (United States)

    CUI, C.; Hou, W.

    2017-12-01

    Full waveform inversion (FWI) aims to construct high-precision subsurface models by fully using the information in seismic records, including amplitude, travel time, phase and so on. However, high non-linearity and the absence of low frequency information in seismic data lead to the well-known cycle skipping problem and make inversion easily fall into local minima. In addition, those 3D inversion methods that are based on acoustic approximation ignore the elastic effects in real seismic field, and make inversion harder. As a result, the accuracy of final inversion results highly relies on the quality of initial model. In order to improve stability and quality of inversion results, multi-scale inversion that reconstructs subsurface model from low to high frequency are applied. But, the absence of very low frequencies (time domain and inversion in the frequency domain. To accelerate the inversion, we adopt CPU/GPU heterogeneous computing techniques. There were two levels of parallelism. In the first level, the inversion tasks are decomposed and assigned to each computation node by shot number. In the second level, GPU multithreaded programming is used for the computation tasks in each node, including forward modeling, envelope extraction, DFT (discrete Fourier transform) calculation and gradients calculation. Numerical tests demonstrated that the combined envelope inversion + hybrid-domain FWI could obtain much faithful and accurate result than conventional hybrid-domain FWI. The CPU/GPU heterogeneous parallel computation could improve the performance speed.

  11. Seasonal variation and natural infection of Lutzomyia antunesi (Diptera: Psychodidae: Phlebotominae, an endemic species in the Orinoquia region of Colombia

    Directory of Open Access Journals (Sweden)

    Adolfo Vasquez Trujillo

    2013-06-01

    Full Text Available Lutzomyia antunesi has been commonly reported in outbreaks of cutaneous leishmaniasis (CL in the Orinoquia region of Colombia. The bionomics of this species were studied in the municipality of Villavicencio (Meta, Colombia. Sandflies were captured over the course of one week per month for one year in intradomiciliary, peridomiciliary and extradomiciliary housing areas. The captures were performed from 06:00 pm-06:00 am using CDC light traps and the females were processed for polymerase chain reaction (PCR to detect Leishmania spp. A total of 22,097 specimens and 19 species were captured of which Lu. antunesi (89% and Lutzomyia walkeri (5% were the most abundant. Other species recognised as anthropophilic (Lutzomyia panamensis, Lutzomyia gomezi, Lutzomyia flaviscutellata and Lutzomyia fairtigi were present in very low abundance (< 2%. Natural infection with Leishmania spp was detected using PCR in Lu. antunesi, Lu. panamensis and Lu. flavicutellata, showing infection rates of 1%, 4.8% and 7.5%, respectively. The present paper provides information on various ecological aspects of Lu. antunesi. An analysis of seasonality shows that this species increases in abundance in the hottest months (December, January and February, directly correlating with the maximum temperature and inversely correlating with precipitation. The natural infection rate is associated with the peaks of highest abundance.

  12. Seasonal variation and natural infection of Lutzomyia antunesi (Diptera: Psychodidae: Phlebotominae), an endemic species in the Orinoquia region of Colombia.

    Science.gov (United States)

    Vásquez Trujillo, Adolfo; González Reina, Angélica E; Góngora Orjuela, Agustín; Prieto Suárez, Edgar; Palomares, Jairo Enrique; Buitrago Alvarez, Luz Stella

    2013-06-01

    Lutzomyia antunesi has been commonly reported in outbreaks of cutaneous leishmaniasis (CL) in the Orinoquia region of Colombia. The bionomics of this species were studied in the municipality of Villavicencio (Meta, Colombia). Sandflies were captured over the course of one week per month for one year in intradomiciliary, peridomiciliary and extradomiciliary housing areas. The captures were performed from 06:00 pm-06:00 am using CDC light traps and the females were processed for polymerase chain reaction (PCR) to detect Leishmania spp. A total of 22,097 specimens and 19 species were captured of which Lu. antunesi (89%) and Lutzomyia walkeri (5%) were the most abundant. Other species recognised as anthropophilic (Lutzomyia panamensis, Lutzomyia gomezi, Lutzomyia flaviscutellata and Lutzomyia fairtigi) were present in very low abundance (< 2%). Natural infection with Leishmania spp was detected using PCR in Lu. antunesi, Lu. panamensis and Lu. flavicutellata, showing infection rates of 1%, 4.8% and 7.5%, respectively. The present paper provides information on various ecological aspects of Lu. antunesi. An analysis of seasonality shows that this species increases in abundance in the hottest months (December, January and February), directly correlating with the maximum temperature and inversely correlating with precipitation. The natural infection rate is associated with the peaks of highest abundance.

  13. Research on Double Price Regulations and Peak Shaving Reserve Mechanism in Coal-Electricity Supply Chain

    Directory of Open Access Journals (Sweden)

    Hongjun Peng

    2013-01-01

    Full Text Available The game models were used to study the mechanism of coal-electricity price conflict under conditions of double price regulations of coal and electricity. Based on this, the peak shaving reserve mechanism was designed to probe into the countermeasures against the coal-electricity price conflicts. The study revealed that in the boom seasons of coal demand, the initiatives of the coal enterprises to supply thermal coal and the electricity enterprises to order thermal coal are reduced under conditions of double price regulations. However, under the circumstances of coal price marketization, in the boom seasons of coal demand the thermal coal price may go up obviously, the initiatives of the coal enterprises to supply thermal coal are increased, and meanwhile the initiatives of the power enterprises to order thermal coal are decreased dramatically. The transportation capacity constraint of coal supply leads to the evident decrease of the initiatives of coal enterprises for the thermal coal supply. The mechanism of peak shaving reserve of thermal coal may not only reduce the price of coal market but also increase the enthusiasm of the power enterprises to order more thermal coal and the initiatives of the coal enterprises to supply more thermal coal.

  14. MULTI-LINE STOKES INVERSION FOR PROMINENCE MAGNETIC-FIELD DIAGNOSTICS

    International Nuclear Information System (INIS)

    Casini, R.; Lopez Ariste, A.; Paletou, F.; Leger, L.

    2009-01-01

    We present test results on the simultaneous inversion of the Stokes profiles of the He I lines at 587.6 nm (D 3 ) and 1083.0 nm in prominences (90 deg. scattering). We created data sets of synthetic Stokes profiles for the case of quiescent prominences (B -3 of the peak intensity for the polarimetric sensitivity of the simulated observations. In this work, we focus on the error analysis for the inference of the magnetic field vector, under the usual assumption that the prominence can be assimilated to a slab of finite optical thickness with uniform magnetic and thermodynamic properties. We find that the simultaneous inversion of the two lines significantly reduces the errors on the inference of the magnetic field vector, with respect to the case of single-line inversion. These results provide a solid justification for current and future instrumental efforts with multi-line capabilities for the observations of solar prominences and filaments.

  15. Theory of peak coalescence in Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Boldin, Ivan A; Nikolaev, Eugene N

    2009-10-01

    Peak coalescence, i.e. the merging of two close peaks in a Fourier transform ion cyclotron resonance (FTICR) mass spectrum at a high number of ions, plays an important role in various FTICR experiments. In order to describe the coalescence phenomenon we would like to propose a new theory of motion for ion clouds with close mass-to-charge ratios, driven by a uniform magnetic field and Coulomb interactions between the clouds. We describe the motion of the ion clouds in terms of their averaged drift motion in crossed magnetic and electric fields. The ion clouds are considered to be of constant size and their motion is studied in two dimensions. The theory deals with the first-order approximation of the equations of motion in relation to dm/m, where dm is the mass difference and m is the mass of a single ion. The analysis was done for an arbitrary inter-cloud interaction potential, which makes it possible to analyze finite-size ion clouds of any shape. The final analytical expression for the condition of the onset of coalescence is found for the case of uniformly charged spheres. An algorithm for finding this condition for an arbitrary interaction potential is proposed. The critical number of ions for the peak coalescence to take place is shown to depend quadratically on the magnetic field strength and to be proportional to the cyclotron radius and inversely proportional to the ion masses. Copyright (c) 2009 John Wiley & Sons, Ltd.

  16. Support minimized inversion of acoustic and elastic wave scattering

    International Nuclear Information System (INIS)

    Safaeinili, A.

    1994-01-01

    This report discusses the following topics on support minimized inversion of acoustic and elastic wave scattering: Minimum support inversion; forward modelling of elastodynamic wave scattering; minimum support linearized acoustic inversion; support minimized nonlinear acoustic inversion without absolute phase; and support minimized nonlinear elastic inversion

  17. Gamma-Ray Peak Integration: Accuracy and Precision

    International Nuclear Information System (INIS)

    Richard M. Lindstrom

    2000-01-01

    The accuracy of singlet gamma-ray peak areas obtained by a peak analysis program is immaterial. If the same algorithm is used for sample measurement as for calibration and if the peak shapes are similar, then biases in the integration method cancel. Reproducibility is the only important issue. Even the uncertainty of the areas computed by the program is trivial because the true standard uncertainty can be experimentally assessed by repeated measurements of the same source. Reproducible peak integration was important in a recent standard reference material certification task. The primary tool used for spectrum analysis was SUM, a National Institute of Standards and Technology interactive program to sum peaks and subtract a linear background, using the same channels to integrate all 20 spectra. For comparison, this work examines other peak integration programs. Unlike some published comparisons of peak performance in which synthetic spectra were used, this experiment used spectra collected for a real (though exacting) analytical project, analyzed by conventional software used in routine ways. Because both components of the 559- to 564-keV doublet are from 76 As, they were integrated together with SUM. The other programs, however, deconvoluted the peaks. A sensitive test of the fitting algorithm is the ratio of reported peak areas. In almost all the cases, this ratio was much more variable than expected from the reported uncertainties reported by the program. Other comparisons to be reported indicate that peak integration is still an imperfect tool in the analysis of gamma-ray spectra

  18. Relationships between electroencephalographic spectral peaks across frequency bands

    Directory of Open Access Journals (Sweden)

    Sacha Jennifer Van Albada

    2013-03-01

    Full Text Available The degree to which electroenencephalographic (EEG spectral peaks are independent, and the relationships between their frequencies have been debated. A novel fitting method was used to determine peak parameters in the range 2–35 Hz from a large sample of eyes-closed spectra, and their interrelationships were investigated. Findings were compared with a mean-field model of thalamocortical activity, which predicts near-harmonic relationships between peaks. The subject set consisted of 1424 healthy subjects from the Brain Resource International Database. Peaks in the theta range occurred on average near half the alpha peak frequency, while peaks in the beta range tended to occur near twice and three times the alpha peak frequency on an individual-subject basis. Moreover, for the majority of subjects, alpha peak frequencies were significantly positively correlated with frequencies of peaks in the theta and low and high beta ranges. Such a harmonic progression agrees semiquantitatively with theoretical predictions from the mean-field model. These findings indicate a common or analogous source for different rhythms, and help to define appropriate individual frequency bands for peak identification.

  19. Relationships between Electroencephalographic Spectral Peaks Across Frequency Bands

    Science.gov (United States)

    van Albada, S. J.; Robinson, P. A.

    2013-01-01

    The degree to which electroencephalographic spectral peaks are independent, and the relationships between their frequencies have been debated. A novel fitting method was used to determine peak parameters in the range 2–35 Hz from a large sample of eyes-closed spectra, and their interrelationships were investigated. Findings were compared with a mean-field model of thalamocortical activity, which predicts near-harmonic relationships between peaks. The subject set consisted of 1424 healthy subjects from the Brain Resource International Database. Peaks in the theta range occurred on average near half the alpha peak frequency, while peaks in the beta range tended to occur near twice and three times the alpha peak frequency on an individual-subject basis. Moreover, for the majority of subjects, alpha peak frequencies were significantly positively correlated with frequencies of peaks in the theta and low and high beta ranges. Such a harmonic progression agrees semiquantitatively with theoretical predictions from the mean-field model. These findings indicate a common or analogous source for different rhythms, and help to define appropriate individual frequency bands for peak identification. PMID:23483663

  20. Particle in cell simulation of peaking switch for breakdown evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Umbarkar, Sachin B.; Bindu, S.; Mangalvedekar, H.A.; Saxena, A.; Singh, N.M., E-mail: sachin.b.umbarkar@gmail.com [Department of Electric Engineering, Veermata Jijabai Technological Institute, Mumbai (India); Sharma, Archana; Saroj, P.C.; Mittal, K.C. [Accelerator Pulse Power Division, Bhabha Atomic Research Centre, Mumbai (India)

    2014-07-01

    Marx generator connected to peaking capacitor and peaking switch can generate Ultra-Wideband (UWB) radiation. A new peaking switch is designed for converting the existing nanosecond Marx generator to a UWB source. The paper explains the particle in cell (PIC) simulation for this peaking switch, using MAGIC 3D software. This peaking switch electrode is made up of copper tungsten material and is fixed inside the hermitically sealed derlin material. The switch can withstand a gas pressure up to 13.5 kg/cm{sup 2}. The lower electrode of the switch is connected to the last stage of the Marx generator. Initially Marx generator (without peaking stage) in air; gives the output pulse with peak amplitude of 113.75 kV and pulse rise time of 25 ns. Thus, we design a new peaking switch to improve the rise time of output pulse and to pressurize this peaking switch separately (i.e. Marx and peaking switch is at different pressure). The PIC simulation gives the particle charge density, current density, E counter plot, emitted electron current, and particle energy along the axis of gap between electrodes. The charge injection and electric field dependence on ionic dissociation phenomenon are briefly analyzed using this simulation. The model is simulated with different gases (N{sub 2}, H{sub 2}, and Air) under different pressure (2 kg/cm{sup 2}, 5 kg/cm{sup 2}, 10 kg/cm{sup 2}). (author)

  1. QRS peak detection for heart rate monitoring on Android smartphone

    Science.gov (United States)

    Pambudi Utomo, Trio; Nuryani, Nuryani; Darmanto

    2017-11-01

    In this study, Android smartphone is used for heart rate monitoring and displaying electrocardiogram (ECG) graph. Heart rate determination is based on QRS peak detection. Two methods are studied to detect the QRS complex peak; they are Peak Threshold and Peak Filter. The acquisition of ECG data is utilized by AD8232 module from Analog Devices, three electrodes, and Microcontroller Arduino UNO R3. To record the ECG data from a patient, three electrodes are attached to particular body’s surface of a patient. Patient’s heart activity which is recorded by AD8232 module is decoded by Arduino UNO R3 into analog data. Then, the analog data is converted into a voltage value (mV) and is processed to get the QRS complex peak. Heart rate value is calculated by Microcontroller Arduino UNO R3 uses the QRS complex peak. Voltage, heart rate, and the QRS complex peak are sent to Android smartphone by Bluetooth HC-05. ECG data is displayed as the graph by Android smartphone. To evaluate the performance of QRS complex peak detection method, three parameters are used; they are positive predictive, accuracy and sensitivity. Positive predictive, accuracy, and sensitivity of Peak Threshold method is 92.39%, 70.30%, 74.62% and for Peak Filter method are 98.38%, 82.47%, 83.61%, respectively.

  2. Seasonal changes in plant-water relations influence patterns of leaf display in Miombo woodlands: evidence of water conservative strategies.

    Science.gov (United States)

    Vinya, Royd; Malhi, Yadvinder; Brown, Nick D; Fisher, Joshua B; Brodribb, Timothy; Aragão, Luiz E O C

    2018-06-15

    Water availability has frequently been linked to seasonal leaf display in seasonally dry ecosystems, but there have been few ecohydrological investigations of this link. Miombo woodland is a dominant seasonally dry tropical forest ecosystem type in southern Africa; however, there are few data on the relationship between seasonal dynamics in plant-water relations and patterns of leaf display for Miombo woodland. Here we investigate this relationship among nine key Miombo woodland tree species differing in drought tolerance ability and leaf phenology. Results of this study showed that seasonal patterns of leaf phenology varied significantly with seasonal changes in stem water relations among the nine species. Leaf shedding coincided with the attainment of seasonal minimum stem water potential. Leaf flush occurred following xylem rehydration at the peak of the dry season suggesting that endogenous plant factors play a pivotal role in seasonal leaf display in this forest type. Drought-tolerant deciduous species suffered significantly higher seasonal losses in xylem hydraulic conductivity than the drought-intolerant semi-evergreen tree species (P water stress in seasonally dry tropical forests selects for water conservative traits that protect the vulnerable xylem transport system. Therefore, seasonal rhythms in xylem transport dictate patterns of leaf display in seasonally dry tropical forests.

  3. Seasonal patterns of periphyton nitrogen fixation in calcareous wetlands

    Science.gov (United States)

    Liao, X.; Inglett, P.

    2011-12-01

    Periphyton mats are an ecologically important component of the Everglades ecosystem and plays various vital ecological functions. However, nitrogen fixation of periphyton, has received little attention throughout much of the Everglades system. The objective of this study was to characterize the seasonal pattern of periphyton N2 fixation in the Hole-in-the-Donut (HID) of Florida Everglades, where farmed marl prairie wetlands have been restored through complete soil removal (CSR) to reduce nutrient levels. Two restored areas (i.e., cleared in 2000 and 2003) and a reference (natural and unfarmed) marl prairie wetland sites were selected in the HID. Seven times of sampling were performed across the wet and dry season during the 2010 and 2011. The annual fixed nitrogen was approximately 0.4gN m-2 yr-1 in the restored sites which was higher in the reference site (~0.2gN m-2 yr-1). All the three sites showed similar seasonal patterns of N2 fixation that is higher values were observed in the wet season; but the peak value was one month later in reference sits (i.e., September) comparing to the restored areas (i.e., July). The peak of periphyton AR rates in the 2000- and 2003-restored areas appeared in July (i.e., wet season) within the range of 20-79 nmols g-1dw h-1 and 31-53nmols g-1dw h-1, respectively. In contrast, the peak of reference site was observed in September with the range of 2-5 nmols g-1dw h-1. Stable N isotopic ratios (i.e., δ15N) also varied with time but didn't show consistent seasonal pattern as nitrogen fixation. N2 fixation positively correlated with periphyton total phosphorus (TP) and negatively correlated with total nitrogen and phosphorus molar ratios (TN:TP), indicating that N2 fixation would be a indicator of nutrient limitation. In general, δ15N was negatively correlated with nitrogenase activity but the correlation became weakened in the wet season, especially in the flooded July and September, which would be explained by other environmental

  4. Statistics of lower tropospheric inversions over the continental United States

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.H.; Zhang, S.D.; Yi, F. [Wuhan Univ., Hubei (China). School of Electronic Information; Ministry of Education, Wuhan, Hubei (China). Key Lab. of Geospace Environment and Geodesy; State Observatory for Atmospheric Remote Sensing, Wuhan (China); Chen, Z.Y. [Chinese Academy of Sciences, Beijing (China). Inst. of Atmospheric Sciences

    2011-07-01

    The basic structure parameters of lower tropospheric inversions (LTIs) have been derived from 10 years (1998-2007) of high vertical resolution ({proportional_to}50 m) radiosonde observations over 56 United States stations. Seasonal and longitudinal variability of these parameters are presented and the formation mechanisms of LTI are also discussed. It is found that LTI seems to be a common feature over the continental United States. The LTI occurrence rates (defined as the fraction of measurements with LTI, which is calculated from the number of LTI cases divided by the number of measurements of the whole 10 years) at these 56 stations vary from 3.7% to 14.5%; the averaged base heights of LTI have a range of 3-5 km above mean sea level (a.m.s.l.); the averaged thicknesses and temperature jump ranges from 420-465m and 1.9-2.2 K, respectively. These parameters have an obvious seasonal variation. In winter, all the occurrence rates, thicknesses and temperature jumps of LTI have much larger values than those in summer. LTI occurrence rate shows an obvious west-east increasing trend in all 4 seasons. Detailed analyses reveal that dynamical instability induced by strong zonal wind shear is responsible for LTI in winter, spring and autumn; the frontal system tends to generate LTI in summer. Since the higher occurrence rate, larger temperature jump and larger thickness of LTI occur in winter, we believe strong zonal wind shear plays a more important role in the formation of LTI. (orig.)

  5. Statistics of lower tropospheric inversions over the continental United States

    Directory of Open Access Journals (Sweden)

    Y. H. Zhang

    2011-02-01

    Full Text Available The basic structure parameters of lower tropospheric inversions (LTIs have been derived from 10 years (1998–2007 of high vertical resolution (~50 m radiosonde observations over 56 United States stations. Seasonal and longitudinal variability of these parameters are presented and the formation mechanisms of LTI are also discussed. It is found that LTI seems to be a common feature over the continental United States. The LTI occurrence rates (defined as the fraction of measurements with LTI, which is calculated from the number of LTI cases divided by the number of measurements of the whole 10 years at these 56 stations vary from 3.7% to 14.5%; the averaged base heights of LTI have a range of 3–5 km above mean sea level (a.m.s.l.; the averaged thicknesses and temperature jump ranges from 420–465 m and 1.9–2.2 K, respectively. These parameters have an obvious seasonal variation. In winter, all the occurrence rates, thicknesses and temperature jumps of LTI have much larger values than those in summer. LTI occurrence rate shows an obvious west-east increasing trend in all 4 seasons. Detailed analyses reveal that dynamical instability induced by strong zonal wind shear is responsible for LTI in winter, spring and autumn; the frontal system tends to generate LTI in summer. Since the higher occurrence rate, larger temperature jump and larger thickness of LTI occur in winter, we believe strong zonal wind shear plays a more important role in the formation of LTI.

  6. Cold water immersion of the ankle decreases neuromuscular response of lower limb after inversion movement

    OpenAIRE

    Macedo, Christiane S. G.; Alonso, Carolina S.; Liporaci, Rogério F.; Vieira, Fernando; Guirro, Rinaldo R. J.

    2014-01-01

    BACKGROUND: Cryotherapy has been associated with a significant decrease in nerve conduction velocity and muscle contraction with possible effects on exercise and physical training. OBJECTIVES: To quantify the electromyographic response of the lateral gastrocnemius, tibialis anterior, fibularis longus, rectus femoris and gluteus medius to ankle inversion following cold water immersion. METHOD: The peak values of the root mean square (RMS) were obtained from 35 healthy and active univ...

  7. The thermodynamic spin magnetization of strongly correlated 2d electrons in a silicon inversion layer

    OpenAIRE

    Prus, O.; Yaish, Y.; Reznikov, M.; Sivan, U.; Pudalov, V.

    2002-01-01

    A novel method invented to measure the minute thermodynamic spin magnetization of dilute two dimensional fermions is applied to electrons in a silicon inversion layer. Interplay between the ferromagnetic interaction and disorder enhances the low temperature susceptibility up to 7.5 folds compared with the Pauli susceptibility of non-interacting electrons. The magnetization peaks in the vicinity of the density where transition to strong localization takes place. At the same density, the suscep...

  8. Seasonal Variations in Color Preference.

    Science.gov (United States)

    Schloss, Karen B; Nelson, Rolf; Parker, Laura; Heck, Isobel A; Palmer, Stephen E

    2017-08-01

    We investigated how color preferences vary according to season and whether those changes could be explained by the ecological valence theory (EVT). To do so, we assessed the same participants' preferences for the same colors during fall, winter, spring, and summer in the northeastern United States, where there are large seasonal changes in environmental colors. Seasonal differences were most pronounced between fall and the other three seasons. Participants liked fall-associated dark-warm colors-for example, dark-red, dark-orange (brown), dark-yellow (olive), and dark-chartreuse-more during fall than other seasons. The EVT could explain these changes with a modified version of Palmer and Schloss' (2010) weighted affective valence estimate (WAVE) procedure that added an activation term to the WAVE equation. The results indicate that color preferences change according to season, as color-associated objects become more/less activated in the observer. These seasonal changes in color preferences could not be characterized by overall shifts in weights along cone-contrast axes. Copyright © 2016 Cognitive Science Society, Inc.

  9. 3rd Annual Workshop on Inverse Problem

    CERN Document Server

    2015-01-01

    This proceeding volume is based on papers presented on the Third Annual Workshop on Inverse Problems which was organized by the Department of Mathematical Sciences, Chalmers University of Technology and University of Gothenburg, and took place in May 2013 in Stockholm. The purpose of this workshop was to present new analytical developments and numerical techniques for solution of inverse problems for a wide range of applications in acoustics, electromagnetics, optical fibers, medical imaging, geophysics, etc. The contributions in this volume reflect these themes and will be beneficial to researchers who are working in the area of applied inverse problems.

  10. Inverse problems in the Bayesian framework

    International Nuclear Information System (INIS)

    Calvetti, Daniela; Somersalo, Erkki; Kaipio, Jari P

    2014-01-01

    The history of Bayesian methods dates back to the original works of Reverend Thomas Bayes and Pierre-Simon Laplace: the former laid down some of the basic principles on inverse probability in his classic article ‘An essay towards solving a problem in the doctrine of chances’ that was read posthumously in the Royal Society in 1763. Laplace, on the other hand, in his ‘Memoirs on inverse probability’ of 1774 developed the idea of updating beliefs and wrote down the celebrated Bayes’ formula in the form we know today. Although not identified yet as a framework for investigating inverse problems, Laplace used the formalism very much in the spirit it is used today in the context of inverse problems, e.g., in his study of the distribution of comets. With the evolution of computational tools, Bayesian methods have become increasingly popular in all fields of human knowledge in which conclusions need to be drawn based on incomplete and noisy data. Needless to say, inverse problems, almost by definition, fall into this category. Systematic work for developing a Bayesian inverse problem framework can arguably be traced back to the 1980s, (the original first edition being published by Elsevier in 1987), although articles on Bayesian methodology applied to inverse problems, in particular in geophysics, had appeared much earlier. Today, as testified by the articles in this special issue, the Bayesian methodology as a framework for considering inverse problems has gained a lot of popularity, and it has integrated very successfully with many traditional inverse problems ideas and techniques, providing novel ways to interpret and implement traditional procedures in numerical analysis, computational statistics, signal analysis and data assimilation. The range of applications where the Bayesian framework has been fundamental goes from geophysics, engineering and imaging to astronomy, life sciences and economy, and continues to grow. There is no question that Bayesian

  11. NLSE: Parameter-Based Inversion Algorithm

    Science.gov (United States)

    Sabbagh, Harold A.; Murphy, R. Kim; Sabbagh, Elias H.; Aldrin, John C.; Knopp, Jeremy S.

    Chapter 11 introduced us to the notion of an inverse problem and gave us some examples of the value of this idea to the solution of realistic industrial problems. The basic inversion algorithm described in Chap. 11 was based upon the Gauss-Newton theory of nonlinear least-squares estimation and is called NLSE in this book. In this chapter we will develop the mathematical background of this theory more fully, because this algorithm will be the foundation of inverse methods and their applications during the remainder of this book. We hope, thereby, to introduce the reader to the application of sophisticated mathematical concepts to engineering practice without introducing excessive mathematical sophistication.

  12. Inverse problems for the Boussinesq system

    International Nuclear Information System (INIS)

    Fan, Jishan; Jiang, Yu; Nakamura, Gen

    2009-01-01

    We obtain two results on inverse problems for a 2D Boussinesq system. One is that we prove the Lipschitz stability for the inverse source problem of identifying a time-independent external force in the system with observation data in an arbitrary sub-domain over a time interval of the velocity and the data of velocity and temperature at a fixed positive time t 0 > 0 over the whole spatial domain. The other one is that we prove a conditional stability estimate for an inverse problem of identifying the two initial conditions with a single observation on a sub-domain

  13. Population inversion in a stationary recombining plasma

    International Nuclear Information System (INIS)

    Otsuka, M.

    1980-01-01

    Population inversion, which occurs in a recombining plasma when a stationary He plasma is brought into contact with a neutral gas, is examined. With hydrogen as a contact gas, noticeable inversion between low-lying levels of H as been found. The overpopulation density is of the order of 10 8 cm -3 , which is much higher then that (approx. =10 5 cm -3 ) obtained previously with He as a contact gas. Relations between these experimental results and the conditions for population inversion are discussed with the CR model

  14. Inverse Raman effect: applications and detection techniques

    International Nuclear Information System (INIS)

    Hughes, L.J. Jr.

    1980-08-01

    The processes underlying the inverse Raman effect are qualitatively described by comparing it to the more familiar phenomena of conventional and stimulated Raman scattering. An experession is derived for the inverse Raman absorption coefficient, and its relationship to the stimulated Raman gain is obtained. The power requirements of the two fields are examined qualitatively and quantitatively. The assumption that the inverse Raman absorption coefficient is constant over the interaction length is examined. Advantages of the technique are discussed and a brief survey of reported studies is presented

  15. Inverse Raman effect: applications and detection techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, L.J. Jr.

    1980-08-01

    The processes underlying the inverse Raman effect are qualitatively described by comparing it to the more familiar phenomena of conventional and stimulated Raman scattering. An experession is derived for the inverse Raman absorption coefficient, and its relationship to the stimulated Raman gain is obtained. The power requirements of the two fields are examined qualitatively and quantitatively. The assumption that the inverse Raman absorption coefficient is constant over the interaction length is examined. Advantages of the technique are discussed and a brief survey of reported studies is presented.

  16. Multiparameter Optimization for Electromagnetic Inversion Problem

    Directory of Open Access Journals (Sweden)

    M. Elkattan

    2017-10-01

    Full Text Available Electromagnetic (EM methods have been extensively used in geophysical investigations such as mineral and hydrocarbon exploration as well as in geological mapping and structural studies. In this paper, we developed an inversion methodology for Electromagnetic data to determine physical parameters of a set of horizontal layers. We conducted Forward model using transmission line method. In the inversion part, we solved multi parameter optimization problem where, the parameters are conductivity, dielectric constant, and permeability of each layer. The optimization problem was solved by simulated annealing approach. The inversion methodology was tested using a set of models representing common geological formations.

  17. Using movement behaviour to define biological seasons for woodland caribou

    Directory of Open Access Journals (Sweden)

    Tyler D. Rudolph

    2012-03-01

    Full Text Available Terrestrial mammals are strongly influenced by seasonal changes in environmental conditions. Studies of animal space use behaviour are therefore inherently seasonal in nature. We propose an individual-based quantitative method for identifying seasonal shifts in caribou movement behaviour and we demonstrate its use in determining the onset of the winter, spring dispersal, and calving seasons. Using pooled data for the population we demonstrate an alternate approach using polynomial regression with mixed effects. We then compare individual onset dates with population-based estimates and those adopted by expert consensus for our study area. Distributions of individual-based onset dates were normally distributed with prominent modes; however, there was considerable variation in individual onset times. Population-based estimates were closer to the peaks of individual estimates than were expert-based estimates, which fell outside the onetailed 90% and 95% sample quantiles of individually-fitted distributions for spring and winter, respectively. Both expertand population-based estimates were later for winter and earlier for both spring and calving than were individual-based estimates. We discuss the potential consequences of neglecting to corroborate conventionally used dates with observed seasonal trends in movement behaviour. In closing, we recommend researchers adopt an individual-based quantitative approach and a variable temporal window for data set extraction.

  18. Seasonality of dizziness and vertigo in a tropical region.

    Science.gov (United States)

    Pereira, Alcione Botelho; Almeida, Leonardo Alves Ferreira; Pereira, Nayara Gorette; Menezes, Patrícia Andrade Freitas de; Felipe, Lilian; Volpe, Fernando Madalena

    2015-06-01

    Vertigo and dizziness are among the most common medical complaints in the emergency room, and are associated with a considerable personal and health care burden. Scarce and conflicting reports indicate those symptoms may present a seasonal distribution. This study aimed at investigating the existence of a seasonal distribution of vertigo/dizziness in a tropical region, and the correlations of these findings with climatic variables. The charts of all patients consecutively admitted between 2009 and 2012 in the emergency room of a Brazilian general hospital were reviewed. A total of 4920 cases containing these terms were sorted from a sample of 276,076 emergency records. Seasonality was assessed using Cosinor Analysis. Pearson's correlations were performed between the incidence of consultations, considering separately dizziness and vertigo and each of the predictor climatic variables of that index month. Significant seasonal patterns were observed for dizziness and vertigo in the emergency room. Vertigo was more frequent in late winter-spring, negatively correlating to humidity (r = -0.374; p = 0.013) and rainfall (r = -0.334; p = 0.020). Dizziness peaked on summer months, and positively correlated to average temperatures (r = 0.520; p vertigo indicate possible distinct underlying mechanisms of how seasons may influence the occurrence of those symptoms.

  19. Seasonal variations in vertical migration of glacier lanternfish, Benthosema glaciale

    KAUST Repository

    Dypvik, Eivind; Rø stad, Anders; Kaartvedt, Stein

    2012-01-01

    The seasonal variations in glacier lanternfish (Benthosema glaciale) vertical distribution and diel vertical migration (DVM) were studied by use of a bottom-mounted upward-facing 38 kHz echo sounder deployed at 392 m depth and cabled to shore in Masfjorden (~6052?N, ~524?E), Norway. Acoustic data from July 2007-October 2008 were analyzed, and scattering layers below ~220 m during daytime were attributed to glacier lanternfish based on net sampling in this, and previous studies, as well as from analysis of the acoustic data. At these depths, three different diel behavioral strategies were apparent: normal diel vertical migration (NDVM), inverse DVM (IDVM), and no DVM (NoDVM). NoDVM was present all year, while IDVM was present in autumn and winter, and NDVM was present during spring and summer. The seasonal differences in DVM behavior seem to correlate with previously established seasonal distribution of prey. We hypothesize that in regions with seasonally migrating zooplankton, such as where calanoid copepods overwinter at depth, similar plasticity in DVM behavior might occur in other populations of lanternfishes. 2012 The Author(s).

  20. Seasonal variations in vertical migration of glacier lanternfish, Benthosema glaciale

    KAUST Repository

    Dypvik, Eivind

    2012-06-05

    The seasonal variations in glacier lanternfish (Benthosema glaciale) vertical distribution and diel vertical migration (DVM) were studied by use of a bottom-mounted upward-facing 38 kHz echo sounder deployed at 392 m depth and cabled to shore in Masfjorden (~6052?N, ~524?E), Norway. Acoustic data from July 2007-October 2008 were analyzed, and scattering layers below ~220 m during daytime were attributed to glacier lanternfish based on net sampling in this, and previous studies, as well as from analysis of the acoustic data. At these depths, three different diel behavioral strategies were apparent: normal diel vertical migration (NDVM), inverse DVM (IDVM), and no DVM (NoDVM). NoDVM was present all year, while IDVM was present in autumn and winter, and NDVM was present during spring and summer. The seasonal differences in DVM behavior seem to correlate with previously established seasonal distribution of prey. We hypothesize that in regions with seasonally migrating zooplankton, such as where calanoid copepods overwinter at depth, similar plasticity in DVM behavior might occur in other populations of lanternfishes. 2012 The Author(s).

  1. BOOK REVIEW: Inverse Problems. Activities for Undergraduates

    Science.gov (United States)

    Yamamoto, Masahiro

    2003-06-01

    This book is a valuable introduction to inverse problems. In particular, from the educational point of view, the author addresses the questions of what constitutes an inverse problem and how and why we should study them. Such an approach has been eagerly awaited for a long time. Professor Groetsch, of the University of Cincinnati, is a world-renowned specialist in inverse problems, in particular the theory of regularization. Moreover, he has made a remarkable contribution to educational activities in the field of inverse problems, which was the subject of his previous book (Groetsch C W 1993 Inverse Problems in the Mathematical Sciences (Braunschweig: Vieweg)). For this reason, he is one of the most qualified to write an introductory book on inverse problems. Without question, inverse problems are important, necessary and appear in various aspects. So it is crucial to introduce students to exercises in inverse problems. However, there are not many introductory books which are directly accessible by students in the first two undergraduate years. As a consequence, students often encounter diverse concrete inverse problems before becoming aware of their general principles. The main purpose of this book is to present activities to allow first-year undergraduates to learn inverse theory. To my knowledge, this book is a rare attempt to do this and, in my opinion, a great success. The author emphasizes that it is very important to teach inverse theory in the early years. He writes; `If students consider only the direct problem, they are not looking at the problem from all sides .... The habit of always looking at problems from the direct point of view is intellectually limiting ...' (page 21). The book is very carefully organized so that teachers will be able to use it as a textbook. After an introduction in chapter 1, sucessive chapters deal with inverse problems in precalculus, calculus, differential equations and linear algebra. In order to let one gain some insight

  2. The shifting nature of vegetation controls on peak snowpack with varying slope and aspect

    Science.gov (United States)

    Biederman, J. A.; Harpold, A. A.; Broxton, P. D.; Brooks, P. D.

    2012-12-01

    The controls on peak seasonal snowpack are known to shift between forested and open environments as well as with slope and aspect. Peak snowpack is predicted well by interception models under uniformly dense canopy, while topography, wind and radiation are strong predictors in open areas. However, many basins have complex mosaics of forest canopy and small gaps, where snowpack controls involve complex interactions among climate, topography and forest structure. In this presentation we use a new fully distributed tree-scale model to investigate vegetation controls on snowpack for a range of slope and aspect, and we evaluate the energy balance in forest canopy and gap environments. The model is informed by airborne LiDAR and ground-based observations of climate, vegetation and snowpack. It represents interception, snow distribution by wind, latent and sensible heat fluxes, and radiative fluxes above and below the canopy at a grid scale of 1 m square on an hourly time step. First, the model is minimally calibrated using continuous records of snow depth and snow water equivalent (SWE). Next, the model is evaluated using distributed observations at peak accumulation. Finally, the domain is synthetically altered to introduce ranges of slope and aspect. Northerly aspects accumulate greater peak SWE than southerly aspects (e.g. 275 mm vs. 250 mm at a slope of 28 %) but show lower spatial variability (e. g. CV = 0.14 vs. CV = 0.17 at slope of 28 %). On northerly aspects, most of the snowpack remains shaded by vegetation, whereas on southerly aspects the northern portions of gaps and southern forest edges receive direct insolation during late winter. This difference in net radiation makes peak SWE in forest gaps and adjacent forest edges more sensitive to topography than SWE in areas under dense canopy. Tree-scale modeling of snow dynamics over synthetic terrain offers extensive possibilities to test interactions among vegetation and topographic controls.

  3. Phenological synchrony and seasonality of understory Rubiaceae in the Atlantic Forest, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Heitor Scarpati Liuth

    2013-03-01

    Full Text Available In tropical forests with low seasonality, climatic variables generally exert a weak influence on the phenology of species. The seasonality of phenophases in closely related taxa can be controlled by phylogenetic constraints in such environments. In this study, our aim was to describe the phenology of Rubiaceae in the understory of the Atlantic Forest in the southern part of Bahia, Brazil, as well as to evaluate the seasonality and phenological synchrony of this family. For two years, we observed 90 individuals belonging to 13 species, in an area of 0.2 ha. Leaf flushing and leaf fall did not demonstrate any seasonality, were continuous for most species and correlated with few of the climatic variables. Flowering was seasonal and correlated positively with all climatic variables. Species exhibited seasonality for this phenophase with high flowering overlap among species of Psychotria, indicating an aggregated pattern for this genus. Fruiting was also seasonal and correlated with all the climatic variables, unripe fruit development peaking at the beginning of the season during which humidity is highest and fruit ripening peaking in the season during which humidity is slightly lower. The vegetative and flowering patterns observed in the study area are commonly seen in other tropical forests. The reproductive seasonality of this family can facilitate the attraction of biotic agents, as postulated in the facilitation hypothesis. Our results demonstrate that climatic variables influenced the phenological patterns observed here, although the high reproductive seasonality and interspecific synchrony, especially in congeneric species, raises the possibility that phylogenetic proximity plays a role in the pattern of the family Rubiaceae.

  4. Estimation of the peak factor based on watershed characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Gauthier, Jean; Nolin, Simon; Ruest, Benoit [BPR Inc., Quebec, (Canada)

    2010-07-01

    Hydraulic modeling and dam structure design require the river flood flow as a primary input. For a given flood event, the ratio of peak flow over mean daily flow defines the peak factor. The peak factor value is dependent on the watershed and location along the river. The main goal of this study consisted in finding a relationship between watershed characteristics and this peak factor. Regression analyses were carried out on 53 natural watersheds located in the southern part of the province of Quebec using data from the Centre d'expertise hydrique du Quebec (CEHQ). The watershed characteristics included in the analyses were the watershed area, the maximum flow length, the mean slope, the lake proportion and the mean elevation. The results showed that watershed area and length are the major parameters influencing the peak factor. Nine natural watersheds were also used to test the use of a multivariable model in order to determine the peak factor for ungauged watersheds.

  5. Evaluation of peak power prediction equations in male basketball players.

    Science.gov (United States)

    Duncan, Michael J; Lyons, Mark; Nevill, Alan M

    2008-07-01

    This study compared peak power estimated using 4 commonly used regression equations with actual peak power derived from force platform data in a group of adolescent basketball players. Twenty-five elite junior male basketball players (age, 16.5 +/- 0.5 years; mass, 74.2 +/- 11.8 kg; height, 181.8 +/- 8.1 cm) volunteered to participate in the study. Actual peak power was determined using a countermovement vertical jump on a force platform. Estimated peak power was determined using countermovement jump height and body mass. All 4 prediction equations were significantly related to actual peak power (all p jump prediction equations, 12% for the Canavan and Vescovi equation, and 6% for the Sayers countermovement jump equation. In all cases peak power was underestimated.

  6. Thermal-hydraulic modeling of flow inversion in a research reactor

    International Nuclear Information System (INIS)

    Kazeminejad, H.

    2008-01-01

    The course of loss of flow accident and flow inversion in a pool type research reactor, with scram enabled under natural circulation condition is numerically investigated. The analyses were performed by a lumped parameters approach for the coupled kinetic-thermal-hydraulics, with continuous feedback due to coolant and fuel temperature effects. A modified Runge-Kutta method was adopted for a better solution to the set of stiff differential equations. Transient thermal-hydraulics during the process of flow inversion and establishment of natural circulation were considered for a 10-MW IAEA research reactor. Some important parameters such as the peak temperatures for the hot channel were obtained for both high-enriched and low enriched fuel. The model prediction is also verified through comparison with other computer code results reported in the literature for detailed simulations of loss of flow accidents (LOFA) and the agreement between the results for the peak clad temperatures and key parameters has been satisfactory. It was found that the flow inversion and subsequent establishment of natural circulation keep the peak cladding surface temperature below the saturation temperature to avoid the escalation of clad temperature to the level of onset of nucleate boiling and sub-cooled void formation to ensure the safe operation of the reactor

  7. Seasonal variation of seismic ambient noise level at King Sejong Station, Antarctica

    Science.gov (United States)

    Lee, W.; Sheen, D.; Seo, K.; Yun, S.

    2009-12-01

    The generation of the secondary- or double-frequency (DF) microseisms with dominant frequencies between 0.1 and 0.5 Hz has been explained by nonlinear second-order pressure perturbations on the ocean bottom due to the interference of two ocean waves of equal wavelengths traveling in opposite directions. Korea Polar Research Institute (KOPRI) has been operating a broadband seismic station (KSJ1) at King George Island (KGI), Antarctica, since 2001. Examining the ambient seismic noise level for the period from 2006 to 2008 at KSJ1, we found a significant seasonal variation in the frequency range 0.1-0.5 Hz. Correlation of the DF peaks with significant ocean wave height and peak wave period models indicates that the oceanic infragravity waves in the Drake Passage is a possible source to excite the DF microseisms at KGI. Location of King Sejong Station, Antarctica Seasonal variations of DF peak, significant wave height, and peak wave period

  8. Peak experiences of psilocybin users and non-users.

    Science.gov (United States)

    Cummins, Christina; Lyke, Jennifer

    2013-01-01

    Maslow (1970) defined peak experiences as the most wonderful experiences of a person's life, which may include a sense of awe, well-being, or transcendence. Furthermore, recent research has suggested that psilocybin can produce experiences subjectively rated as uniquely meaningful and significant (Griffiths et al. 2006). It is therefore possible that psilocybin may facilitate or change the nature of peak experiences in users compared to non-users. This study was designed to compare the peak experiences of psilocybin users and non-users, to evaluate the frequency of peak experiences while under the influence of psilocybin, and to assess the perceived degree of alteration of consciousness during these experiences. Participants were recruited through convenience and snowball sampling from undergraduate classes and at a musical event. Participants were divided into three groups, those who reported a peak experience while under the influence of psilocybin (psilocybin peak experience: PPE), participants who had used psilocybin but reported their peak experiences did not occur while they were under the influence of psilocybin (non-psilocybin peak experience: NPPE), and participants who had never used psilocybin (non-user: NU). A total of 101 participants were asked to think about their peak experiences and complete a measure evaluating the degree of alteration of consciousness during that experience. Results indicated that 47% of psilocybin users reported their peak experience occurred while using psilocybin. In addition, there were significant differences among the three groups on all dimensions of alteration of consciousness. Future research is necessary to identify factors that influence the peak experiences of psilocybin users in naturalistic settings and contribute to the different characteristics of peak experiences of psilocybin users and non-users.

  9. Extragalactic Peaked-spectrum Radio Sources at Low Frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Callingham, J. R.; Gaensler, B. M.; Sadler, E. M.; Lenc, E. [Sydney Institute for Astronomy (SIfA), School of Physics, The University of Sydney, NSW 2006 (Australia); Ekers, R. D.; Bell, M. E. [CSIRO Astronomy and Space Science (CASS), Marsfield, NSW 2122 (Australia); Line, J. L. B.; Hancock, P. J.; Kapińska, A. D.; McKinley, B.; Procopio, P. [ARC Centre of Excellence for All-Sky Astrophysics (CAASTRO) (Australia); Hurley-Walker, N.; Tingay, S. J.; Franzen, T. M. O.; Morgan, J. [International Centre for Radio Astronomy Research (ICRAR), Curtin University, Bentley, WA 6102 (Australia); Dwarakanath, K. S. [Raman Research Institute (RRI), Bangalore 560080 (India); For, B.-Q. [International Centre for Radio Astronomy Research (ICRAR), The University of Western Australia, Crawley, WA 6009 (Australia); Hindson, L.; Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140 (New Zealand); Offringa, A. R., E-mail: joseph.callingham@sydney.edu.au [Netherlands Institute for Radio Astronomy (ASTRON), Dwingeloo (Netherlands); and others

    2017-02-20

    We present a sample of 1483 sources that display spectral peaks between 72 MHz and 1.4 GHz, selected from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. The GLEAM survey is the widest fractional bandwidth all-sky survey to date, ideal for identifying peaked-spectrum sources at low radio frequencies. Our peaked-spectrum sources are the low-frequency analogs of gigahertz-peaked spectrum (GPS) and compact-steep spectrum (CSS) sources, which have been hypothesized to be the precursors to massive radio galaxies. Our sample more than doubles the number of known peaked-spectrum candidates, and 95% of our sample have a newly characterized spectral peak. We highlight that some GPS sources peaking above 5 GHz have had multiple epochs of nuclear activity, and we demonstrate the possibility of identifying high-redshift ( z > 2) galaxies via steep optically thin spectral indices and low observed peak frequencies. The distribution of the optically thick spectral indices of our sample is consistent with past GPS/CSS samples but with a large dispersion, suggesting that the spectral peak is a product of an inhomogeneous environment that is individualistic. We find no dependence of observed peak frequency with redshift, consistent with the peaked-spectrum sample comprising both local CSS sources and high-redshift GPS sources. The 5 GHz luminosity distribution lacks the brightest GPS and CSS sources of previous samples, implying that a convolution of source evolution and redshift influences the type of peaked-spectrum sources identified below 1 GHz. Finally, we discuss sources with optically thick spectral indices that exceed the synchrotron self-absorption limit.

  10. The sharp peak-flat trough pattern and critical speculation

    OpenAIRE

    Roehner, B. M.; Sornette, D.

    1998-01-01

    We find empirically a characteristic sharp peak-flat trough pattern in a large set of commodity prices. We argue that the sharp peak structure reflects an endogenous inter-market organization, and that peaks may be seen as local ``singularities'' resulting from imitation and herding. These findings impose a novel stringent constraint on the construction of models. Intermittent amplification is not sufficient and nonlinear effects seem necessary to account for the observations.

  11. Gamma-ray peak shapes from cadmium zinc telluride detectors

    Energy Technology Data Exchange (ETDEWEB)

    Namboodiri, M.N.; Lavietes, A.D.; McQuaid, J.H.

    1996-09-01

    We report the results of a study of the peak shapes in the gamma spectra measured using several 5 x 5 x 5 mm{sup 3} cadmium zinc telluride (CZT) detectors. A simple parameterization involving a Gaussian and an exponential low energy tail describes the peak shapes sell. We present the variation of the parameters with gamma energy. This type of information is very useful in the analysis of complex gamma spectra consisting of many peaks.

  12. Statistics of peaks in cosmological nonlinear density fields

    International Nuclear Information System (INIS)

    Suginohara, Tatsushi; Suto, Yasushi.

    1990-06-01

    Distribution of the high-density peaks in the universe is examined using N-body simulations. Nonlinear evolution of the underlying density field significantly changes the statistical properties of the peaks, compared with the analytic results valid for the random Gaussian field. In particular, the abundances and correlations of the initial density peaks are discussed in the context of biased galaxy formation theory. (author)

  13. Environmental impacts of public transport. Why peak-period travellers cause a greater environmental burden than off-peak travellers

    International Nuclear Information System (INIS)

    Rietveld, P.

    2002-01-01

    Given the difference between peak and off-peak occupancy rates in public transport, emissions per traveller kilometre are lower in the peak than in the off-peak period, whereas the opposite pattern is observed for cars. It is argued that it is much more fruitful to analyse environmental effects in marginal terms. This calls for a careful analysis of capacity management policies of public transport suppliers that are facing increased demand during both peak and off-peak periods. A detailed analysis of capacity management by the Netherlands Railways (NS) revealed that off-peak capacity supply is mainly dictated by the demand levels during the peak period. The analysis included the effects of increased frequency and increased vehicle size on environmental impacts, while environmental economies of vehicle size were also taken into account. The main conclusion is that the marginal environmental burden during the peak hours is much higher than is usually thought, whereas it is almost zero during the off-peak period. This implies a pattern that is the precise opposite of the average environmental burden. Thus, an analysis of environmental effects of public transport based on average performance would yield misleading conclusions [nl

  14. Case-based reported mortality associated with laboratory-confirmed influenza A(H1N1 2009 virus infection in the Netherlands: the 2009-2010 pandemic season versus the 2010-2011 influenza season

    Directory of Open Access Journals (Sweden)

    Timen Aura

    2011-10-01

    Full Text Available Abstract Background In contrast to seasonal influenza epidemics, where the majority of deaths occur amongst elderly, a considerable part of the 2009 pandemic influenza related deaths concerned relatively young people. In the Netherlands, all deaths associated with laboratory-confirmed influenza A(H1N1 2009 virus infection had to be notified, both during the 2009-2010 pandemic season and the 2010-2011 influenza season. To assess whether and to what extent pandemic mortality patterns were reverting back to seasonal patterns, a retrospective analyses of all notified fatal cases associated with laboratory-confirmed influenza A(H1N1 2009 virus infection was performed. Methods The notification database, including detailed information about the clinical characteristics of all notified deaths, was used to perform a comprehensive analysis of all deceased patients with a laboratory-confirmed influenza A(H1N1 2009 virus infection. Characteristics of the fatalities with respect to age and underlying medical conditions were analysed, comparing the 2009-2010 pandemic and the 2010-2011 influenza season. Results A total of 65 fatalities with a laboratory-confirmed influenza A(H1N1 2009 virus infection were notified in 2009-2010 and 38 in 2010-2011. During the pandemic season, the population mortality rates peaked in persons aged 0-15 and 55-64 years. In the 2010-2011 influenza season, peaks in mortality were seen in persons aged 0-15 and 75-84 years. During the 2010-2011 influenza season, the height of first peak was lower compared to that during the pandemic season. Underlying immunological disorders were more common in the pandemic season compared to the 2010-2011 season (p = 0.02, and cardiovascular disorders were more common in the 2010-2011 season (p = 0.005. Conclusions The mortality pattern in the 2010-2011 influenza season still resembled the 2009-2010 pandemic season with a peak in relatively young age groups, but concurrently a clear shift toward

  15. Parametric optimization of inverse trapezoid oleophobic surfaces

    DEFF Research Database (Denmark)

    Cavalli, Andrea; Bøggild, Peter; Okkels, Fridolin

    2012-01-01

    In this paper, we introduce a comprehensive and versatile approach to the parametric shape optimization of oleophobic surfaces. We evaluate the performance of inverse trapezoid microstructures in terms of three objective parameters: apparent contact angle, maximum sustainable hydrostatic pressure...

  16. An inverse method for radiation transport

    Energy Technology Data Exchange (ETDEWEB)

    Favorite, J. A. (Jeffrey A.); Sanchez, R. (Richard)

    2004-01-01

    Adjoint functions have been used with forward functions to compute gradients in implicit (iterative) solution methods for inverse problems in optical tomography, geoscience, thermal science, and other fields, but only once has this approach been used for inverse solutions to the Boltzmann transport equation. In this paper, this approach is used to develop an inverse method that requires only angle-independent flux measurements, rather than angle-dependent measurements as was done previously. The method is applied to a simplified form of the transport equation that does not include scattering. The resulting procedure uses measured values of gamma-ray fluxes of discrete, characteristic energies to determine interface locations in a multilayer shield. The method was implemented with a Newton-Raphson optimization algorithm, and it worked very well in numerical one-dimensional spherical test cases. A more sophisticated optimization method would better exploit the potential of the inverse method.

  17. The Transmuted Generalized Inverse Weibull Distribution

    Directory of Open Access Journals (Sweden)

    Faton Merovci

    2014-05-01

    Full Text Available A generalization of the generalized inverse Weibull distribution the so-called transmuted generalized inverse Weibull distribution is proposed and studied. We will use the quadratic rank transmutation map (QRTM in order to generate a flexible family of probability distributions taking the generalized inverseWeibull distribution as the base value distribution by introducing a new parameter that would offer more distributional flexibility. Various structural properties including explicit expressions for the moments, quantiles, and moment generating function of the new distribution are derived. We propose the method of maximum likelihood for estimating the model parameters and obtain the observed information matrix. A real data set are used to compare the flexibility of the transmuted version versus the generalized inverse Weibull distribution.

  18. Parameterization analysis and inversion for orthorhombic media

    KAUST Repository

    Masmoudi, Nabil

    2018-01-01

    Accounting for azimuthal anisotropy is necessary for the processing and inversion of wide-azimuth and wide-aperture seismic data because wave speeds naturally depend on the wave propagation direction. Orthorhombic anisotropy is considered the most

  19. Wave-equation reflection traveltime inversion

    KAUST Repository

    Zhang, Sanzong; Schuster, Gerard T.; Luo, Yi

    2011-01-01

    The main difficulty with iterative waveform inversion using a gradient optimization method is that it tends to get stuck in local minima associated within the waveform misfit function. This is because the waveform misfit function is highly nonlinear

  20. Voxel inversion of airborne EM data

    DEFF Research Database (Denmark)

    Fiandaca, Gianluca G.; Auken, Esben; Christiansen, Anders Vest C A.V.C.

    2013-01-01

    We present a geophysical inversion algorithm working directly in a voxel grid disconnected from the actual measuring points, which allows for straightforward integration of different data types in joint inversion, for informing geological/hydrogeological models directly and for easier incorporation...... of prior information. Inversion of geophysical data usually refers to a model space being linked to the actual observation points. For airborne surveys the spatial discretization of the model space reflects the flight lines. Often airborne surveys are carried out in areas where other ground......-based geophysical data are available. The model space of geophysical inversions is usually referred to the positions of the measurements, and ground-based model positions do not generally coincide with the airborne model positions. Consequently, a model space based on the measuring points is not well suited...

  1. Deep controls on intraplate basin inversion

    DEFF Research Database (Denmark)

    Nielsen, S.B.; Stephenson, Randell Alexander; Schiffer, Christian

    2014-01-01

    Basin inversion is an intermediate-scale manifestation of continental intraplate deformation, which produces earthquake activity in the interior of continents. The sedimentary basins of central Europe, inverted in the Late Cretaceous– Paleocene, represent a classic example of this phenomenon....... It is known that inversion of these basins occurred in two phases: an initial one of transpressional shortening involving reverse activation of former normal faults and a subsequent one of uplift of the earlier developed inversion axis and a shift of sedimentary depocentres, and that this is a response...... to changes in the regional intraplate stress field. This European intraplate deformation is considered in thecontext of a new model of the present-day stress field of Europe (and the North Atlantic) caused by lithospheric potential energy variations. Stresses causingbasin inversion of Europe must have been...

  2. Multiscattering inversion for low-model wavenumbers

    KAUST Repository

    Alkhalifah, Tariq Ali; Wu, Zedong

    2016-01-01

    A successful full-waveform inversion implementation updates the low-wavenumber model components first for a proper description of the wavefield propagation and slowly adds the high wavenumber potentially scattering parts of the model. The low

  3. Full traveltime inversion in source domain

    KAUST Repository

    Liu, Lu; Guo, Bowen; Luo, Yi

    2017-01-01

    This paper presents a new method of source-domain full traveltime inversion (FTI). The objective of this study is automatically building near-surface velocity using the early arrivals of seismic data. This method can generate the inverted velocity

  4. On two-spectra inverse problems

    OpenAIRE

    Guliyev, Namig J.

    2018-01-01

    We consider a two-spectra inverse problem for the one-dimensional Schr\\"{o}dinger equation with boundary conditions containing rational Herglotz--Nevanlinna functions of the eigenvalue parameter and provide a complete solution of this problem.

  5. An inverse problem for evolution inclusions

    OpenAIRE

    Ton, Bui An

    2002-01-01

    An inverse problem, the determination of the shape and a convective coefficient on a part of the boundary from partial measurements of the solution, is studied using 2-person optimal control techniques.

  6. Hopping absorption edge in silicon inversion layers

    International Nuclear Information System (INIS)

    Kostadinov, I.Z.

    1983-09-01

    The low frequency gap observed in the absorption spectrum of silicon inversion layers is related to the AC variable range hopping. The frequency dependence of the absorption coefficient is calculated. (author)

  7. Full traveltime inversion in source domain

    KAUST Repository

    Liu, Lu

    2017-06-01

    This paper presents a new method of source-domain full traveltime inversion (FTI). The objective of this study is automatically building near-surface velocity using the early arrivals of seismic data. This method can generate the inverted velocity that can kinetically best match the reconstructed plane-wave source of early arrivals with true source in source domain. It does not require picking first arrivals for tomography, which is one of the most challenging aspects of ray-based tomographic inversion. Besides, this method does not need estimate the source wavelet, which is a necessity for receiver-domain wave-equation velocity inversion. Furthermore, we applied our method on one synthetic dataset; the results show our method could generate a reasonable background velocity even when shingling first arrivals exist and could provide a good initial velocity for the conventional full waveform inversion (FWI).

  8. The inverse square law of gravitation

    International Nuclear Information System (INIS)

    Cook, A.H.

    1987-01-01

    The inverse square law of gravitation is very well established over the distances of celestial mechanics, while in electrostatics the law has been shown to be followed to very high precision. However, it is only within the last century that any laboratory experiments have been made to test the inverse square law for gravitation, and all but one has been carried out in the last ten years. At the same time, there has been considerable interest in the possibility of deviations from the inverse square law, either because of a possible bearing on unified theories of forces, including gravitation or, most recently, because of a possible additional fifth force of nature. In this article the various lines of evidence for the inverse square law are summarized, with emphasis upon the recent laboratory experiments. (author)

  9. Neglected puerperal inversion of the uterus

    African Journals Online (AJOL)

    abp

    2012-07-27

    Jul 27, 2012 ... managed surgically with Haultain's operation and discharged after 5 ... Acute inversion generally occurs during or immediately after childbirth, while chronic ... is difficult unless the fundal depression can be palpated on rectal.

  10. n-Colour self-inverse compositions

    Indian Academy of Sciences (India)

    inverse composition. This introduces four new sequences which satisfy the same recurrence relation with different initial conditions like the famous Fibonacci and Lucas sequences. For these new sequences explicit formulas, recurrence relations ...

  11. Spatiotemporal phenological changes in fall foliage peak coloration in deciduous forest and the responses to climatic variation

    Science.gov (United States)

    Xie, Y.; Wilson, A. M.

    2017-12-01

    Plant phenology studies typically focus on the beginning and end of the growing season in temperate forests. We know too little about fall foliage peak coloration, which is a bioindicator of plant response in autumn to environmental changes, an important visual cue in fall associated with animal activities, and a key element in fall foliage ecotourism. Spatiotemporal changes in timing of fall foliage peak coloration of temperate forests and the associated environmental controls are not well understood. In this study, we examined multiple color indices to estimate Land Surface Phenology (LSP) of fall foliage peak coloration of deciduous forest in the northeastern USA using Moderate Resolution Imaging Spectroradiometer (MODIS) daily imagery from 2000 to 2015. We used long term phenology ground observations to validate our estimated LSP, and found that Visible Atmospherically Resistant Index (VARI) and Plant Senescence Reflectance Index (PSRI) were good metrics to estimate peak and end of leaf coloration period of deciduous forest. During the past 16 years, the length of period with peak fall foliage color of deciduous forest at southern New England and northern Appalachian forests regions became longer (0.3 7.7 days), mainly driven by earlier peak coloration. Northern New England, southern Appalachian forests and Ozark and Ouachita mountains areas had shorter period (‒0.2 ‒9.2 days) mainly due to earlier end of leaf coloration. Changes in peak and end of leaf coloration not only were associated with changing temperature in spring and fall, but also to drought and heat in summer, and heavy precipitation in both summer and fall. The associations between leaf peak coloration phenology and climatic variations were not consistent among ecoregions. Our findings suggested divergent change patterns in fall foliage peak coloration phenology in deciduous forests, and improved our understanding in the environmental control on timing of fall foliage color change.

  12. The European Market for Seasonal Gas Storage

    International Nuclear Information System (INIS)

    Mahan, A.

    2006-02-01

    European demand for gas will grow in the years to come. Simultaneously, gas production in Europe will decrease and imported gas will be needed to replace indigenous production. Gas demand is not constant during the year. There are variations in demand on different timescales ranging from seasonal to hourly. Variations in demand are characterised by two main parameters: working volume and deliverability. Working volume - the amount of gas that can be supplied above the baseload production volume during a long (cold) period- is primarily needed to cope with the summer-winter pattern of gas consumption. Most of the summer-winter pattern comes from the temperature sensitive gas consumption by households and service industries. Gas usage by industry and the power sector are more evenly spread throughout the year and need less working volume. Deliverability - the amount of gas per hour that can be generated on a (very) cold day above the baseload capacity - is the ability to produce large volumes during short periods, e.g. for extremely cold days, or during peak periods during a day. In this paper we argue that a large amount of additional working volume will be required over the coming years. First, flexible European production will be replaced by long-distance import gas, and second, the gas market is expected to grow further. Todays market appears focus mainly on cavems for storage volume. Cavems have little working volume but are ideal for trading purposes. Consequently, Europe may be facing a deficit in working volume, i.e. the ability to cope with seasonal changes in demand. This paper aims to widen the discussion of this matter and give rise to this concern by setting out a broad analysis, exploring the market drivers for seasonal storage and identifying the public interest issues for this market. Chapter 2 gives an overview of demand for and supply characteristics of gas flexibility. Chapter 3 describes the role of gas storage facilities in the gas market

  13. The dislocation-internal friction peak γ in tantalum

    International Nuclear Information System (INIS)

    Baur, J.; Benoit, W.; Schultz, H.

    1989-01-01

    Torsion-pendulum measurements were carried out on high-purity single crystal specimens of tantalum, having extremely low oxygen contents ( 2 peak, which appears close to γ is small traces of oxygen are presents. The γ 2 peak was formerly explained as a ''dislocation-enhanced Snoek peak''. The γ peak recovers at the peak temperature, whereas the γ 2 peak is more stable. On the basis of their results, and making use of earlier investigations of Rodrian and Schultz, the authors suggest that γ 2 is modified γ relaxation, related to screw-dislocation segments, stabilized by oxygen-decorated kinks. The stability of the γ 2 peak allows an accurate determination of the activation energy, found to be 1.00 +- 0.03 eV. This value is distinctly lower than the activation energy of the oxygen Snoek effect (1.10 eV) and is related here to the mechanism of ''kink-pair formation'' in screw dislocations, as the original γ peak. The numerical value is compatible with recent values derived from flow-stress measurements. The peak γ 2 shows increasing stability with increasing oxygen content. This is explained by single- and multi-decorated kinks

  14. Evaluation of peak-fitting software for gamma spectrum analysis

    International Nuclear Information System (INIS)

    Zahn, Guilherme S.; Genezini, Frederico A.; Moralles, Mauricio

    2009-01-01

    In all applications of gamma-ray spectroscopy, one of the most important and delicate parts of the data analysis is the fitting of the gamma-ray spectra, where information as the number of counts, the position of the centroid and the width, for instance, are associated with each peak of each spectrum. There's a huge choice of computer programs that perform this type of analysis, and the most commonly used in routine work are the ones that automatically locate and fit the peaks; this fit can be made in several different ways - the most common ways are to fit a Gaussian function to each peak or simply to integrate the area under the peak, but some software go far beyond and include several small corrections to the simple Gaussian peak function, in order to compensate for secondary effects. In this work several gamma-ray spectroscopy software are compared in the task of finding and fitting the gamma-ray peaks in spectra taken with standard sources of 137 Cs, 60 Co, 133 Ba and 152 Eu. The results show that all of the automatic software can be properly used in the task of finding and fitting peaks, with the exception of GammaVision; also, it was possible to verify that the automatic peak-fitting software did perform as well as - and sometimes even better than - a manual peak-fitting software. (author)

  15. Individual vision and peak distribution in collective actions

    Science.gov (United States)

    Lu, Peng

    2017-06-01

    People make decisions on whether they should participate as participants or not as free riders in collective actions with heterogeneous visions. Besides of the utility heterogeneity and cost heterogeneity, this work includes and investigates the effect of vision heterogeneity by constructing a decision model, i.e. the revised peak model of participants. In this model, potential participants make decisions under the joint influence of utility, cost, and vision heterogeneities. The outcomes of simulations indicate that vision heterogeneity reduces the values of peaks, and the relative variance of peaks is stable. Under normal distributions of vision heterogeneity and other factors, the peaks of participants are normally distributed as well. Therefore, it is necessary to predict distribution traits of peaks based on distribution traits of related factors such as vision heterogeneity and so on. We predict the distribution of peaks with parameters of both mean and standard deviation, which provides the confident intervals and robust predictions of peaks. Besides, we validate the peak model of via the Yuyuan Incident, a real case in China (2014), and the model works well in explaining the dynamics and predicting the peak of real case.

  16. Bayesian approach for peak detection in two-dimensional chromatography.

    Science.gov (United States)

    Vivó-Truyols, Gabriel

    2012-03-20

    A new method for peak detection in two-dimensional chromatography is presented. In a first step, the method starts with a conventional one-dimensional peak detection algorithm to detect modulated peaks. In a second step, a sophisticated algorithm is constructed to decide which of the individual one-dimensional peaks have been originated from the same compound and should then be arranged in a two-dimensional peak. The merging algorithm is based on Bayesian inference. The user sets prior information about certain parameters (e.g., second-dimension retention time variability, first-dimension band broadening, chromatographic noise). On the basis of these priors, the algorithm calculates the probability of myriads of peak arrangements (i.e., ways of merging one-dimensional peaks), finding which of them holds the highest value. Uncertainty in each parameter can be accounted by adapting conveniently its probability distribution function, which in turn may change the final decision of the most probable peak arrangement. It has been demonstrated that the Bayesian approach presented in this paper follows the chromatographers' intuition. The algorithm has been applied and tested with LC × LC and GC × GC data and takes around 1 min to process chromatograms with several thousands of peaks.

  17. Variability in surface inversion characteristics over India in winter ...

    Indian Academy of Sciences (India)

    inversion depth at most of the other stations show that shallow and moderate inversions occur more frequently than deep ..... processed and several checks were applied to ensure homogeneity ... simply inversions) is defined as the layer from ...

  18. Population inversion in recombining hydrogen plasma

    International Nuclear Information System (INIS)

    Furukane, Utaro; Yokota, Toshiaki; Oda, Toshiatsu.

    1978-11-01

    The collisional-radiative model is applied to a recombining hydrogen plasma in order to investigate the plasma condition in which the population inversion between the energy levels of hydrogen can be generated. The population inversion is expected in a plasma where the three body recombination has a large contribution to the recombining processes and the effective recombination rate is beyond a certain value for a given electron density and temperature. Calculated results are presented in figures and tables. (author)

  19. Inverse kinematic control of LDUA and TWRMS

    International Nuclear Information System (INIS)

    Yih, T.C.; Burks, B.L.; Kwon, Dong-Soo

    1995-01-01

    A general inverse kinematic analysis is formulated particularly for the redundant Light Duty Utility Arm (LDUA) and Tank Waste Retrieval Manipulator System (TWRMS). The developed approach is applicable to the inverse kinematic simulation and control of LDUA, TWRMS, and other general robot manipulators. The 4 x 4 homogeneous Cylindrical coordinates-Bryant angles (C-B) notation is adopted to model LDUA, TWRMS, and any robot composed of R (revolute), P (prismatic), and/or S (spherical) joints

  20. Approximation of Bayesian Inverse Problems for PDEs

    OpenAIRE

    Cotter, S. L.; Dashti, M.; Stuart, A. M.

    2010-01-01

    Inverse problems are often ill posed, with solutions that depend sensitively on data.n any numerical approach to the solution of such problems, regularization of some form is needed to counteract the resulting instability. This paper is based on an approach to regularization, employing a Bayesian formulation of the problem, which leads to a notion of well posedness for inverse problems, at the level of probability measures. The stability which results from this well posedness may be used as t...

  1. An Inversion Recovery NMR Kinetics Experiment

    OpenAIRE

    Williams, Travis J.; Kershaw, Allan D.; Li, Vincent; Wu, Xinping

    2011-01-01

    A convenient laboratory experiment is described in which NMR magnetization transfer by inversion recovery is used to measure the kinetics and thermochemistry of amide bond rotation. The experiment utilizes Varian spectrometers with the VNMRJ 2.3 software, but can be easily adapted to any NMR platform. The procedures and sample data sets in this article will enable instructors to use inversion recovery as a laboratory activity in applied NMR classes and provide research students with a conveni...

  2. Bayesian inversion of refraction seismic traveltime data

    Science.gov (United States)

    Ryberg, T.; Haberland, Ch

    2018-03-01

    We apply a Bayesian Markov chain Monte Carlo (McMC) formalism to the inversion of refraction seismic, traveltime data sets to derive 2-D velocity models below linear arrays (i.e. profiles) of sources and seismic receivers. Typical refraction data sets, especially when using the far-offset observations, are known as having experimental geometries which are very poor, highly ill-posed and far from being ideal. As a consequence, the structural resolution quickly degrades with depth. Conventional inversion techniques, based on regularization, potentially suffer from the choice of appropriate inversion parameters (i.e. number and distribution of cells, starting velocity models, damping and smoothing constraints, data noise level, etc.) and only local model space exploration. McMC techniques are used for exhaustive sampling of the model space without the need of prior knowledge (or assumptions) of inversion parameters, resulting in a large number of models fitting the observations. Statistical analysis of these models allows to derive an average (reference) solution and its standard deviation, thus providing uncertainty estimates of the inversion result. The highly non-linear character of the inversion problem, mainly caused by the experiment geometry, does not allow to derive a reference solution and error map by a simply averaging procedure. We present a modified averaging technique, which excludes parts of the prior distribution in the posterior values due to poor ray coverage, thus providing reliable estimates of inversion model properties even in those parts of the models. The model is discretized by a set of Voronoi polygons (with constant slowness cells) or a triangulated mesh (with interpolation within the triangles). Forward traveltime calculations are performed by a fast, finite-difference-based eikonal solver. The method is applied to a data set from a refraction seismic survey from Northern Namibia and compared to conventional tomography. An inversion test

  3. Inverse semigroups the theory of partial symmetries

    CERN Document Server

    Lawson, Mark V

    1998-01-01

    Symmetry is one of the most important organising principles in the natural sciences. The mathematical theory of symmetry has long been associated with group theory, but it is a basic premise of this book that there are aspects of symmetry which are more faithfully represented by a generalization of groups called inverse semigroups. The theory of inverse semigroups is described from its origins in the foundations of differential geometry through to its most recent applications in combinatorial group theory, and the theory tilings.

  4. Seasonal Allergies: Diagnosis, Treatment & Research

    Science.gov (United States)

    ... this page please turn JavaScript on. Feature: Seasonal Allergies Diagnosis, Treatment & Research Past Issues / Spring 2015 Table of Contents Diagnosis Testing for Allergies Knowing exactly what you are allergic to can ...

  5. 2012 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  6. Atmospheric inverse modeling via sparse reconstruction

    Science.gov (United States)

    Hase, Nils; Miller, Scot M.; Maaß, Peter; Notholt, Justus; Palm, Mathias; Warneke, Thorsten

    2017-10-01

    Many applications in atmospheric science involve ill-posed inverse problems. A crucial component of many inverse problems is the proper formulation of a priori knowledge about the unknown parameters. In most cases, this knowledge is expressed as a Gaussian prior. This formulation often performs well at capturing smoothed, large-scale processes but is often ill equipped to capture localized structures like large point sources or localized hot spots. Over the last decade, scientists from a diverse array of applied mathematics and engineering fields have developed sparse reconstruction techniques to identify localized structures. In this study, we present a new regularization approach for ill-posed inverse problems in atmospheric science. It is based on Tikhonov regularization with sparsity constraint and allows bounds on the parameters. We enforce sparsity using a dictionary representation system. We analyze its performance in an atmospheric inverse modeling scenario by estimating anthropogenic US methane (CH4) emissions from simulated atmospheric measurements. Different measures indicate that our sparse reconstruction approach is better able to capture large point sources or localized hot spots than other methods commonly used in atmospheric inversions. It captures the overall signal equally well but adds details on the grid scale. This feature can be of value for any inverse problem with point or spatially discrete sources. We show an example for source estimation of synthetic methane emissions from the Barnett shale formation.

  7. Inverse scattering problems with multi-frequencies

    International Nuclear Information System (INIS)

    Bao, Gang; Li, Peijun; Lin, Junshan; Triki, Faouzi

    2015-01-01

    This paper is concerned with computational approaches and mathematical analysis for solving inverse scattering problems in the frequency domain. The problems arise in a diverse set of scientific areas with significant industrial, medical, and military applications. In addition to nonlinearity, there are two common difficulties associated with the inverse problems: ill-posedness and limited resolution (diffraction limit). Due to the diffraction limit, for a given frequency, only a low spatial frequency part of the desired parameter can be observed from measurements in the far field. The main idea developed here is that if the reconstruction is restricted to only the observable part, then the inversion will become stable. The challenging task is how to design stable numerical methods for solving these inverse scattering problems inspired by the diffraction limit. Recently, novel recursive linearization based algorithms have been presented in an attempt to answer the above question. These methods require multi-frequency scattering data and proceed via a continuation procedure with respect to the frequency from low to high. The objective of this paper is to give a brief review of these methods, their error estimates, and the related mathematical analysis. More attention is paid to the inverse medium and inverse source problems. Numerical experiments are included to illustrate the effectiveness of these methods. (topical review)

  8. Regional inversion of CO2 ecosystem fluxes from atmospheric measurements. Reliability of the uncertainty estimates

    Energy Technology Data Exchange (ETDEWEB)

    Broquet, G.; Chevallier, F.; Breon, F.M.; Yver, C.; Ciais, P.; Ramonet, M.; Schmidt, M. [Laboratoire des Sciences du Climat et de l' Environnement, CEA-CNRS-UVSQ, UMR8212, IPSL, Gif-sur-Yvette (France); Alemanno, M. [Servizio Meteorologico dell' Aeronautica Militare Italiana, Centro Aeronautica Militare di Montagna, Monte Cimone/Sestola (Italy); Apadula, F. [Research on Energy Systems, RSE, Environment and Sustainable Development Department, Milano (Italy); Hammer, S. [Universitaet Heidelberg, Institut fuer Umweltphysik, Heidelberg (Germany); Haszpra, L. [Hungarian Meteorological Service, Budapest (Hungary); Meinhardt, F. [Federal Environmental Agency, Kirchzarten (Germany); Necki, J. [AGH University of Science and Technology, Krakow (Poland); Piacentino, S. [ENEA, Laboratory for Earth Observations and Analyses, Palermo (Italy); Thompson, R.L. [Max Planck Institute for Biogeochemistry, Jena (Germany); Vermeulen, A.T. [Energy research Centre of the Netherlands ECN, EEE-EA, Petten (Netherlands)

    2013-07-01

    The Bayesian framework of CO2 flux inversions permits estimates of the retrieved flux uncertainties. Here, the reliability of these theoretical estimates is studied through a comparison against the misfits between the inverted fluxes and independent measurements of the CO2 Net Ecosystem Exchange (NEE) made by the eddy covariance technique at local (few hectares) scale. Regional inversions at 0.5{sup 0} resolution are applied for the western European domain where {approx}50 eddy covariance sites are operated. These inversions are conducted for the period 2002-2007. They use a mesoscale atmospheric transport model, a prior estimate of the NEE from a terrestrial ecosystem model and rely on the variational assimilation of in situ continuous measurements of CO2 atmospheric mole fractions. Averaged over monthly periods and over the whole domain, the misfits are in good agreement with the theoretical uncertainties for prior and inverted NEE, and pass the chi-square test for the variance at the 30% and 5% significance levels respectively, despite the scale mismatch and the independence between the prior (respectively inverted) NEE and the flux measurements. The theoretical uncertainty reduction for the monthly NEE at the measurement sites is 53% while the inversion decreases the standard deviation of the misfits by 38 %. These results build confidence in the NEE estimates at the European/monthly scales and in their theoretical uncertainty from the regional inverse modelling system. However, the uncertainties at the monthly (respectively annual) scale remain larger than the amplitude of the inter-annual variability of monthly (respectively annual) fluxes, so that this study does not engender confidence in the inter-annual variations. The uncertainties at the monthly scale are significantly smaller than the seasonal variations. The seasonal cycle of the inverted fluxes is thus reliable. In particular, the CO2 sink period over the European continent likely ends later than

  9. An application of sparse inversion on the calculation of the inverse data space of geophysical data

    KAUST Repository

    Saragiotis, Christos

    2011-07-01

    Multiple reflections as observed in seismic reflection measurements often hide arrivals from the deeper target reflectors and need to be removed. The inverse data space provides a natural separation of primaries and surface-related multiples, as the surface multiples map onto the area around the origin while the primaries map elsewhere. However, the calculation of the inverse data is far from trivial as theory requires infinite time and offset recording. Furthermore regularization issues arise during inversion. We perform the inversion by minimizing the least-squares norm of the misfit function and by constraining the 1 norm of the solution, being the inverse data space. In this way a sparse inversion approach is obtained. We show results on field data with an application to surface multiple removal. © 2011 IEEE.

  10. Seasonal variation in internet keyword searches: a proxy assessment of sex mating behaviors.

    Science.gov (United States)

    Markey, Patrick M; Markey, Charlotte N

    2013-05-01

    The current study investigated seasonal variation in internet searches regarding sex and mating behaviors. Harmonic analyses were used to examine the seasonal trends of Google keyword searches during the past 5 years for topics related to pornography, prostitution, and mate-seeking. Results indicated a consistent 6-month harmonic cycle with the peaks of keyword searches related to sex and mating behaviors occurring most frequently during winter and early summer. Such results compliment past research that has found similar seasonal trends of births, sexually transmitted infections, condom sales, and abortions.

  11. Assessing peak aerobic capacity in Dutch law enforcement officers

    Directory of Open Access Journals (Sweden)

    Harriet Wittink

    2015-06-01

    Full Text Available Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report normative absolute and relative VO2peak values of a sample of law enforcement officers in the Netherlands. Material and Methods: The peak rate of oxygen consumption (ml×kg–1×min–1 was measured using a maximal incremental bicycle test in 1530 subjects, including 1068 male and 461 female police officers. Validity of the prediction equations for groups was assessed by comparing predicted VO2peak with measured VO2peak using paired t-tests. For individual differences limits of agreement (LoA were calculated. Equations were considered valid for individuals when the difference between measured and predicted VO2peak did not exceed ±1 metabolic equivalent (MET in 95% of individuals. Results: None of the equations met the validity criterion of 95% of individuals having ±1 MET difference or less than the measured value. Limits of agreement (LoAs were large in all predictions. At the individual level, none of the equations were valid predictors of VO2peak (ml×kg–1×min–1. Normative values for Dutch law enforcement officers were presented. Conclusions: Substantial differences between measured and predicted VO2peak (ml×kg–1×min–1 were found. Most tested equations were invalid predictors of VO2peak at group level and all were invalid at individual levels.

  12. Inverse planning of energy-modulated electron beams in radiotherapy

    International Nuclear Information System (INIS)

    Gentry, John R.; Steeves, Richard; Paliwal, Bhudatt A.

    2006-01-01

    The use of megavoltage electron beams often poses a clinical challenge in that the planning target volume (PTV) is anterior to other radiosensitive structures and has variable depth. To ensure that skin as well as the deepest extent of the PTV receives the prescribed dose entails prescribing to a point beyond the depth of peak dose for a single electron energy. This causes dose inhomogeneities and heightened potential for tissue fibrosis, scarring, and possible soft tissue necrosis. Use of bolus on the skin improves the entrant dose at the cost of decreasing the therapeutic depth that can be treated. Selection of a higher energy to improve dose homogeneity results in increased dose to structures beyond the PTV, as well as enlargement of the volume receiving heightened dose. Measured electron data from a linear accelerator was used as input to create an inverse planning tool employing energy and intensity modulation using bolus (e-IMRT TM ). Using tools readily available in a radiotherapy department, the applications of energy and intensity modulation on the central axis makes it possible to remove hot spots of 115% or more over the depths clinically encountered. The e-IMRT TM algorithm enables the development of patient-specific dose distributions with user-defined positions of peak dose, range, and reduced dose to points beyond the prescription point

  13. A regional high-resolution carbon flux inversion of North America for 2004

    Science.gov (United States)

    Schuh, A. E.; Denning, A. S.; Corbin, K. D.; Baker, I. T.; Uliasz, M.; Parazoo, N.; Andrews, A. E.; Worthy, D. E. J.

    2010-05-01

    . We perform the inversion with two independently derived boundary inflow conditions and calculate jackknife-based statistics to test the robustness of the model results. We then compare final results to estimates obtained from the CarbonTracker inversion system and at the Southern Great Plains flux site. Results are promising, showing the ability to correct carbon fluxes from the biosphere models over annual and seasonal time scales, as well as over the different GPP and ER components. Additionally, the correlation of an estimated sink of carbon in the South Central United States with regional anomalously high precipitation in an area of managed agricultural and forest lands provides interesting hypotheses for future work.

  14. UV hazard on Italian Apennines under different shading and ground cover conditions during peak tourist seasons of the year.

    Science.gov (United States)

    Grifoni, Daniele; Carreras, Giulia; Sabatini, Francesco; Zipoli, Gaetano

    2006-12-01

    In solar UV irradiance monitoring and forecasting services UV information is generally expressed in terms of its effect on erythema and referred to horizontal surface. In this work we define the UV radiative regime, in terms of biologically effective UV irradiance (UVBE) for skin and eye, under full sun and shaded conditions, over a mountainous tourist area of central Italy by means of two all-day measurements (summer and early spring) with different ground albedo (grass and snow cover respectively). UV irradiance was monitored on tilted surfaces (the most frequent for people standing and walking). Results show the significant contribution of ground albedo and sun position in determining the incident UVBE irradiance. On early spring days the UVBE irradiance measured on horizontal surface was much lower than on tilted ones; the opposite condition was observed in summer. The highest UVBE irradiance values, in particular conditions of sun elevation and ground cover, were reached in periods different from the summer both in full sun and shaded condition.

  15. Chromatid Painting for Chromosomal Inversion Detection, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a novel approach to the detection of chromosomal inversions. Transmissible chromosome aberrations (translocations and inversions) have profound genetic...

  16. Optimal enhancement in conversion efficiency of crystalline Si solar cells using inverse opal photonic crystals as back reflectors

    International Nuclear Information System (INIS)

    Chaouachi, A; M’nif, A; Hamzaoui, A H; Chtourou, R

    2015-01-01

    The effect of using inverse opal photonic crystals as back reflectors on the power conversion efficiency of c-Si solar cells is investigated. The reflection spectra of inverse opal photonic crystals with different diameters of air spheres are simulated using the finite difference time domain (FDTD) method. The reflection peaks are correlated with photonic band gaps present in the photonic band gap diagram. Significant improvement in the optical absorption of the crystalline silicon layer is recorded when inverse opal photonic crystals are considered. Physical mechanisms which may contribute to the enhancement of the light absorption are underlined. With higher short-circuit current enhancement possible, and with no corresponding degradation in open-circuit voltage V oc or the fill factor, the power conversion efficiency is increased significantly when inverse opal photonic crystals are used as back reflectors with optimized diameter of air spheres. (paper)

  17. Warm water temperatures and shifts in seasonality increase trout recruitment but only moderately decrease adult size in western North American tailwaters

    Science.gov (United States)

    Dibble, Kimberly L.; Yackulic, Charles B.; Kennedy, Theodore A.

    2018-01-01

    Dams throughout western North America have altered thermal regimes in rivers, creating cold, clear “tailwaters” in which trout populations thrive. Ongoing drought in the region has led to highly publicized reductions in reservoir storage and raised concerns about potential reductions in downstream flows. Large changes in riverine thermal regimes may also occur as reservoir water levels drop, yet this potential impact has received far less attention. We analyzed historic water temperature and fish population data to anticipate how trout may respond to future changes in the magnitude and seasonality of river temperatures. We found that summer temperatures were inversely related to reservoir water level, with warm temperatures associated with reduced storage and with dams operated as run-of-river units. Variation in rainbow trout (Oncorhynchus mykiss) recruitment was linked to water temperature variation, with a 5-fold increase in recruitment occurring at peak summer temperatures (18 °C vs. 7 °C) and a 2.5-fold increase in recruitment when peak temperatures occurred in summer rather than fall. Conversely, adult trout size was only moderately related to temperature. Rainbow and brown trout (Salmo trutta) size decreased by ~24 mm and 20 mm, respectively, as mean annual and peak summer temperatures increased. Further, rainbow trout size decreased by ~29 mm with an earlier onset of cold winter temperatures. While increased recruitment may be the more likely outcome of a warmer and drier climate, density-dependent growth constraints could exacerbate temperature-dependent growth reductions. As such, managers may consider implementing flows to reduce recruitment or altering infrastructure to maintain coldwater reservoir releases.

  18. The Gambia and Bangladesh: the seasons and diarrhoea.

    Science.gov (United States)

    Rowland, M G

    1986-09-01

    Climactic factors in the Gambia and Bangladesh have an important impact on the incidence of diarrheal disease. Both countries share some common characteristics in climate, including a cool dry winter of 3 months followed by a hot dry spring and hot wet summers of 5-7 months in length. The main difference is in the amount of rainfall. The Gambia may have 20-30 inches of rain each year; Bangladesh usually has up to 4-5 times this amount. In the Gambia, drought is a recurring problem; floods is the problem in Bangladesh. A study in the Gambia found a close link between the time of the annual peak in diarrhea in young children and the summer rains. A 2nd peak of diarrhea in the winter also was significant and was shown to coincide with a short period of intense transmission of rotavirus. Of the enteric infections of childhood, the enterotoxigenic "Escherichia coli" (ETEC), that is those producing heat-stable toxin (ST) were found to be the most important etiological agents of diarrhea in both countries, with a peak during the rains. In rural Gambia, water is obtained almost exclusively from surface wells, 15-20 meters deep. It was found that, although this water was fecally contaminated throughout the year, levels of contamination increased by up to 100 times with 1-2 days of the start of the rains because excreta is washed into the wells. It also was clear that contaminated water and domestic environment contribute to contamination of children's food. The high level of contamination of food during the summer coincided with the time of high diarrhea prevalence. In Bangladesh it was shown that the incidence of ETEC diarrhea in infants was positively correlated with the frequency of consumption of weaning foods contaminated with fecal coliforms. The seasonal peak of ETEC diarrhea coincided with the time when food was most contaminated due to higher bacterial growth caused by high temperatures. Cholera is endemic in many areas of Bangladesh but not in the Gambia. Though

  19. Constraining the shape of the CMB: A peak-by-peak analysis

    International Nuclear Information System (INIS)

    Oedman, Carolina J.; Hobson, Michael P.; Lasenby, Anthony N.; Melchiorri, Alessandro

    2003-01-01

    The recent measurements of the power spectrum of cosmic microwave background anisotropies are consistent with the simplest inflationary scenario and big bang nucleosynthesis constraints. However, these results rely on the assumption of a class of models based on primordial adiabatic perturbations, cold dark matter and a cosmological constant. In this paper we investigate the need for deviations from the Λ-CDM scenario by first characterizing the spectrum using a phenomenological function in a 15 dimensional parameter space. Using a Monte Carlo Markov chain approach to Bayesian inference and a low curvature model template we then check for the presence of new physics and/or systematics in the CMB data. We find an almost perfect consistency between the phenomenological fits and the standard Λ-CDM models. The curvature of the secondary peaks is weakly constrained by the present data, but they are well located. The improved spectral resolution expected from future satellite experiments is warranted for a definitive test of the scenario

  20. Analysis of reflection-peak wavelengths of sampled fiber Bragg gratings with large chirp.

    Science.gov (United States)

    Zou, Xihua; Pan, Wei; Luo, Bin

    2008-09-10

    The reflection-peak wavelengths (RPWs) in the spectra of sampled fiber Bragg gratings with large chirp (SFBGs-LC) are theoretically investigated. Such RPWs are divided into two parts, the RPWs of equivalent uniform SFBGs (U-SFBGs) and the wavelength shift caused by the large chirp in the grating period (CGP). We propose a quasi-equivalent transform to deal with the CGP. That is, the CGP is transferred into quasi-equivalent phase shifts to directly derive the Fourier transform of the refractive index modulation. Then, in the case of both the direct and the inverse Talbot effect, the wavelength shift is obtained from the Fourier transform. Finally, the RPWs of SFBGs-LC can be achieved by combining the wavelength shift and the RPWs of equivalent U-SFBGs. Several simulations are shown to numerically confirm these predicted RPWs of SFBGs-LC.