WorldWideScience

Sample records for maximum exposure rates

  1. Maximum entropy production rate in quantum thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Beretta, Gian Paolo, E-mail: beretta@ing.unibs.i [Universita di Brescia, via Branze 38, 25123 Brescia (Italy)

    2010-06-01

    In the framework of the recent quest for well-behaved nonlinear extensions of the traditional Schroedinger-von Neumann unitary dynamics that could provide fundamental explanations of recent experimental evidence of loss of quantum coherence at the microscopic level, a recent paper [Gheorghiu-Svirschevski 2001 Phys. Rev. A 63 054102] reproposes the nonlinear equation of motion proposed by the present author [see Beretta G P 1987 Found. Phys. 17 365 and references therein] for quantum (thermo)dynamics of a single isolated indivisible constituent system, such as a single particle, qubit, qudit, spin or atomic system, or a Bose-Einstein or Fermi-Dirac field. As already proved, such nonlinear dynamics entails a fundamental unifying microscopic proof and extension of Onsager's reciprocity and Callen's fluctuation-dissipation relations to all nonequilibrium states, close and far from thermodynamic equilibrium. In this paper we propose a brief but self-contained review of the main results already proved, including the explicit geometrical construction of the equation of motion from the steepest-entropy-ascent ansatz and its exact mathematical and conceptual equivalence with the maximal-entropy-generation variational-principle formulation presented in Gheorghiu-Svirschevski S 2001 Phys. Rev. A 63 022105. Moreover, we show how it can be extended to the case of a composite system to obtain the general form of the equation of motion, consistent with the demanding requirements of strong separability and of compatibility with general thermodynamics principles. The irreversible term in the equation of motion describes the spontaneous attraction of the state operator in the direction of steepest entropy ascent, thus implementing the maximum entropy production principle in quantum theory. The time rate at which the path of steepest entropy ascent is followed has so far been left unspecified. As a step towards the identification of such rate, here we propose a possible

  2. 7 CFR 3565.210 - Maximum interest rate.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Maximum interest rate. 3565.210 Section 3565.210... AGRICULTURE GUARANTEED RURAL RENTAL HOUSING PROGRAM Loan Requirements § 3565.210 Maximum interest rate. The interest rate for a guaranteed loan must not exceed the maximum allowable rate specified by the Agency in...

  3. Fumigant dosages below maximum label rate control some soilborne pathogens

    Directory of Open Access Journals (Sweden)

    Shachaf Triky-Dotan

    2016-08-01

    Full Text Available The activity of commercial soil fumigants on some key soilborne pathogens was assessed in sandy loam soil under controlled conditions. Seven soil fumigants that are registered in California or are being or have been considered for registration were used in this study: dimethyl disulfide (DMDS mixed with chloropicrin (Pic (79% DMDS and 21% Pic, Tri-Con (50% methyl bromide and 50% Pic, Midas Gold (33% methyl iodide [MI] and 67% Pic, Midas Bronze (50% MI and 50% Pic, Midas (MI, active ingredient [a.i.] 97.8%, Pic (a.i. 99% trichloronitromethane and Pic-Clor 60 (57% Pic and 37% 1,3-dichloropropene [1–3,D]. Dose-response models were calculated for pathogen mortality after 24 hours of exposure to fumigants. Overall, the tested fumigants achieved good efficacy with dosages below the maximum label rate against the tested pathogens. In this study, Pythium ultimum and citrus nematode were sensitive to all the fumigants and Verticillium dahliae was resistant. For most fumigants, California regulations restrict application rates to less than the maximum (federal label rate, meaning that it is possible that the fumigants may not control major plant pathogens. This research provides information on the effectiveness of these alternatives at these lower application rates. The results from this study will help growers optimize application rates for registered fumigants (such as Pic and 1,3-D and will help accelerate the adoption of new fumigants (such as DMDS if they are registered in California.

  4. 5 CFR 531.221 - Maximum payable rate rule.

    Science.gov (United States)

    2010-01-01

    ... before the reassignment. (ii) If the rate resulting from the geographic conversion under paragraph (c)(2... previous rate (i.e., the former special rate after the geographic conversion) with the rates on the current... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Maximum payable rate rule. 531.221...

  5. The calculation of maximum permissible exposure levels for laser radiation

    International Nuclear Information System (INIS)

    Tozer, B.A.

    1979-01-01

    The maximum permissible exposure data of the revised standard BS 4803 are presented as a set of decision charts which ensure that the user automatically takes into account such details as pulse length and pulse pattern, limiting angular subtense, combinations of multiple wavelength and/or multiple pulse lengths, etc. The two decision charts given are for the calculation of radiation hazards to skin and eye respectively. (author)

  6. Application of maximum radiation exposure values and monitoring of radiation exposure

    International Nuclear Information System (INIS)

    1996-01-01

    The guide presents the principles to be applied in calculating the equivalent dose and the effective dose, instructions on application of the maximum values for radiation exposure, and instruction on monitoring of radiation exposure. In addition, the measurable quantities to be used in monitoring the radiation exposure are presented. (2 refs.)

  7. Maximum organic carbon limits at different melter feed rates (U)

    International Nuclear Information System (INIS)

    Choi, A.S.

    1995-01-01

    This report documents the results of a study to assess the impact of varying melter feed rates on the maximum total organic carbon (TOC) limits allowable in the DWPF melter feed. Topics discussed include: carbon content; feed rate; feed composition; melter vapor space temperature; combustion and dilution air; off-gas surges; earlier work on maximum TOC; overview of models; and the results of the work completed

  8. Dinosaur Metabolism and the Allometry of Maximum Growth Rate

    OpenAIRE

    Myhrvold, Nathan P.

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth...

  9. 44 CFR 208.12 - Maximum Pay Rate Table.

    Science.gov (United States)

    2010-10-01

    ...) Physicians. DHS uses the latest Special Salary Rate Table Number 0290 for Medical Officers (Clinical... Personnel, in which case the Maximum Pay Rate Table would not apply. (3) Compensation for Sponsoring Agency... organizations, e.g., HMOs or medical or engineering professional associations, under the revised definition of...

  10. Dinosaur Metabolism and the Allometry of Maximum Growth Rate.

    Science.gov (United States)

    Myhrvold, Nathan P

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth rates of extant groups are found to have a great deal of overlap, including between groups with endothermic and ectothermic metabolism. Dinosaur growth rates show similar overlap, matching the rates found for mammals, reptiles and fish. The allometric scaling of growth rate with mass is found to have curvature (on a log-log scale) for many groups, contradicting the prevailing view that growth rate allometry follows a simple power law. Reanalysis shows that no correlation between growth rate and basal metabolic rate (BMR) has been demonstrated. These findings drive a conclusion that growth rate allometry studies to date cannot be used to determine dinosaur metabolism as has been previously argued.

  11. Dinosaur Metabolism and the Allometry of Maximum Growth Rate

    Science.gov (United States)

    Myhrvold, Nathan P.

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth rates of extant groups are found to have a great deal of overlap, including between groups with endothermic and ectothermic metabolism. Dinosaur growth rates show similar overlap, matching the rates found for mammals, reptiles and fish. The allometric scaling of growth rate with mass is found to have curvature (on a log-log scale) for many groups, contradicting the prevailing view that growth rate allometry follows a simple power law. Reanalysis shows that no correlation between growth rate and basal metabolic rate (BMR) has been demonstrated. These findings drive a conclusion that growth rate allometry studies to date cannot be used to determine dinosaur metabolism as has been previously argued. PMID:27828977

  12. Considerations on the establishment of maximum permissible exposure of man

    International Nuclear Information System (INIS)

    Jacobi, W.

    1974-01-01

    An attempt is made in the information lecture to give a quantitative analysis of the somatic radiation risk and to illustrate a concept to fix dose limiting values. Of primary importance is the limiting values. Of primary importance is the limiting value of the radiation exposure to the whole population. By consequential application of the risk concept, the following points are considered: 1) Definition of the risk for radiation late damages (cancer, leukemia); 2) relationship between radiation dose and thus caused radiation risk; 3) radiation risk and the dose limiting values at the time; 4) criteria for the maximum acceptable radiation risk; 5) limiting value which can be expected at the time. (HP/LH) [de

  13. Application of maximum radiation exposure values and monitoring of radiation exposure

    International Nuclear Information System (INIS)

    1993-01-01

    According to the Section 32 of the Radiation Act (592/91) the Finnish Centre for Radiation and Nuclear Safety gives instructions concerning the monitoring of the radiation exposure and the application of the dose limits in Finland. The principles to be applied to calculating the equivalent and the effective doses are presented in the guide. Also the detailed instructions on the application of the maximum exposure values for the radiation work and for the natural radiation as well as the instructions on the monitoring of the exposures are given. Quantities and units for assessing radiation exposure are presented in the appendix of the guide

  14. Maximum discharge rate of liquid-vapor mixtures from vessels

    International Nuclear Information System (INIS)

    Moody, F.J.

    1975-09-01

    A discrepancy exists in theoretical predictions of the two-phase equilibrium discharge rate from pipes attached to vessels. Theory which predicts critical flow data in terms of pipe exit pressure and quality severely overpredicts flow rates in terms of vessel fluid properties. This study shows that the discrepancy is explained by the flow pattern. Due to decompression and flashing as fluid accelerates into the pipe entrance, the maximum discharge rate from a vessel is limited by choking of a homogeneous bubbly mixture. The mixture tends toward a slip flow pattern as it travels through the pipe, finally reaching a different choked condition at the pipe exit

  15. Analysis of reaction schemes using maximum rates of constituent steps

    Science.gov (United States)

    Motagamwala, Ali Hussain; Dumesic, James A.

    2016-01-01

    We show that the steady-state kinetics of a chemical reaction can be analyzed analytically in terms of proposed reaction schemes composed of series of steps with stoichiometric numbers equal to unity by calculating the maximum rates of the constituent steps, rmax,i, assuming that all of the remaining steps are quasi-equilibrated. Analytical expressions can be derived in terms of rmax,i to calculate degrees of rate control for each step to determine the extent to which each step controls the rate of the overall stoichiometric reaction. The values of rmax,i can be used to predict the rate of the overall stoichiometric reaction, making it possible to estimate the observed reaction kinetics. This approach can be used for catalytic reactions to identify transition states and adsorbed species that are important in controlling catalyst performance, such that detailed calculations using electronic structure calculations (e.g., density functional theory) can be carried out for these species, whereas more approximate methods (e.g., scaling relations) are used for the remaining species. This approach to assess the feasibility of proposed reaction schemes is exact for reaction schemes where the stoichiometric coefficients of the constituent steps are equal to unity and the most abundant adsorbed species are in quasi-equilibrium with the gas phase and can be used in an approximate manner to probe the performance of more general reaction schemes, followed by more detailed analyses using full microkinetic models to determine the surface coverages by adsorbed species and the degrees of rate control of the elementary steps. PMID:27162366

  16. Exercise-induced maximum metabolic rate scaled to body mass by ...

    African Journals Online (AJOL)

    Exercise-induced maximum metabolic rate scaled to body mass by the fractal ... rate scaling is that exercise-induced maximum aerobic metabolic rate (MMR) is ... muscle stress limitation, and maximized oxygen delivery and metabolic rates.

  17. The mechanics of granitoid systems and maximum entropy production rates.

    Science.gov (United States)

    Hobbs, Bruce E; Ord, Alison

    2010-01-13

    A model for the formation of granitoid systems is developed involving melt production spatially below a rising isotherm that defines melt initiation. Production of the melt volumes necessary to form granitoid complexes within 10(4)-10(7) years demands control of the isotherm velocity by melt advection. This velocity is one control on the melt flux generated spatially just above the melt isotherm, which is the control valve for the behaviour of the complete granitoid system. Melt transport occurs in conduits initiated as sheets or tubes comprising melt inclusions arising from Gurson-Tvergaard constitutive behaviour. Such conduits appear as leucosomes parallel to lineations and foliations, and ductile and brittle dykes. The melt flux generated at the melt isotherm controls the position of the melt solidus isotherm and hence the physical height of the Transport/Emplacement Zone. A conduit width-selection process, driven by changes in melt viscosity and constitutive behaviour, operates within the Transport Zone to progressively increase the width of apertures upwards. Melt can also be driven horizontally by gradients in topography; these horizontal fluxes can be similar in magnitude to vertical fluxes. Fluxes induced by deformation can compete with both buoyancy and topographic-driven flow over all length scales and results locally in transient 'ponds' of melt. Pluton emplacement is controlled by the transition in constitutive behaviour of the melt/magma from elastic-viscous at high temperatures to elastic-plastic-viscous approaching the melt solidus enabling finite thickness plutons to develop. The system involves coupled feedback processes that grow at the expense of heat supplied to the system and compete with melt advection. The result is that limits are placed on the size and time scale of the system. Optimal characteristics of the system coincide with a state of maximum entropy production rate. This journal is © 2010 The Royal Society

  18. 78 FR 13999 - Maximum Interest Rates on Guaranteed Farm Loans

    Science.gov (United States)

    2013-03-04

    ..., cost-plus, flat-rate, or market based) to price guaranteed loans, provided the rates do not exceed the... (LIBOR) or the 5-year Treasury note rate, unless the lender uses a formal written risk-based pricing... cost in the form of a lower interest rate than the borrower would otherwise receive. Therefore, the FSA...

  19. The tropical lapse rate steepened during the Last Glacial Maximum

    NARCIS (Netherlands)

    Loomis, S.E.; Russell, J.M.; Verschuren, D.; Morrill, C.; De Cort, G.; Sinninghe Damsté, J.S.; Olago, D.; Eggermont, H.; Street-Perrott, F.A.; Kelly, M.A.

    2017-01-01

    The gradient of air temperature with elevation (the temperature lapse rate) in the tropics is predicted to become lesssteep during the coming century as surface temperature rises, enhancing the threat of warming in high-mountainenvironments. However, the sensitivity of the lapse rate to climate

  20. The tropical lapse rate steepened during the Last Glacial Maximum

    NARCIS (Netherlands)

    Loomis, Shannon E; Russell, James M; Verschuren, Dirk; Morrill, Carrie; De Cort, Gijs; Sinninghe Damsté, Jaap S; Olago, Daniel; Eggermont, Hilde; Street-Perrott, F Alayne; Kelly, Meredith A

    The gradient of air temperature with elevation (the temperature lapse rate) in the tropics is predicted to become less steep during the coming century as surface temperature rises, enhancing the threat of warming in high-mountain environments. However, the sensitivity of the lapse rate to climate

  1. The foreign exchange rate rate exposure of nations

    OpenAIRE

    Entorf, Horst; Moebert, Jochen; Sonderhof, Katja

    2007-01-01

    Following the well-known approach by Adler and Dumas (1984) we evaluate the foreign exchange rate exposure of nations. Results based on data from 27 countries show that national foreign exchange rate exposures are significantly related to the current trade balance variables of corresponding economies.

  2. The Foreign Exchange Rate Exposure of Nations

    OpenAIRE

    Entorf, Horst; Moebert, Jochen; Sonderhof, Katja

    2007-01-01

    Following the well-known approach by Adler and Dumas (1984), we evaluate the foreign exchange rate exposure of nations. Results based on data from 27 countries show that national foreign exchange rate exposures are significantly related to the current trade balance variables of corresponding economies.

  3. Multiple Maximum Exposure Rates in Computerized Adaptive Testing

    Science.gov (United States)

    Ramon Barrada, Juan; Veldkamp, Bernard P.; Olea, Julio

    2009-01-01

    Computerized adaptive testing is subject to security problems, as the item bank content remains operative over long periods and administration time is flexible for examinees. Spreading the content of a part of the item bank could lead to an overestimation of the examinees' trait level. The most common way of reducing this risk is to impose a…

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

    Science.gov (United States)

    Werner, Jan; Griebeler, Eva Maria

    2014-01-01

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

  5. Allometries of maximum growth rate versus body mass at maximum growth indicate that non-avian dinosaurs had growth rates typical of fast growing ectothermic sauropsids.

    Science.gov (United States)

    Werner, Jan; Griebeler, Eva Maria

    2014-01-01

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

  6. Allometries of maximum growth rate versus body mass at maximum growth indicate that non-avian dinosaurs had growth rates typical of fast growing ectothermic sauropsids.

    Directory of Open Access Journals (Sweden)

    Jan Werner

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

  7. Application of maximum values for radiation exposure and principles for the calculation of radiation doses

    International Nuclear Information System (INIS)

    2007-08-01

    The guide presents the definitions of equivalent dose and effective dose, the principles for calculating these doses, and instructions for applying their maximum values. The limits (Annual Limit on Intake and Derived Air Concentration) derived from dose limits are also presented for the purpose of monitoring exposure to internal radiation. The calculation of radiation doses caused to a patient from medical research and treatment involving exposure to ionizing radiation is beyond the scope of this ST Guide

  8. 5 CFR 9901.312 - Maximum rates of base salary and adjusted salary.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Maximum rates of base salary and adjusted salary. 9901.312 Section 9901.312 Administrative Personnel DEPARTMENT OF DEFENSE HUMAN RESOURCES....312 Maximum rates of base salary and adjusted salary. (a) Subject to § 9901.105, the Secretary may...

  9. 47 CFR 1.1507 - Rulemaking on maximum rates for attorney fees.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Rulemaking on maximum rates for attorney fees... § 1.1507 Rulemaking on maximum rates for attorney fees. (a) If warranted by an increase in the cost of... types of proceedings), the Commission may adopt regulations providing that attorney fees may be awarded...

  10. The scaling of maximum and basal metabolic rates of mammals and birds

    Science.gov (United States)

    Barbosa, Lauro A.; Garcia, Guilherme J. M.; da Silva, Jafferson K. L.

    2006-01-01

    Allometric scaling is one of the most pervasive laws in biology. Its origin, however, is still a matter of dispute. Recent studies have established that maximum metabolic rate scales with an exponent larger than that found for basal metabolism. This unpredicted result sets a challenge that can decide which of the concurrent hypotheses is the correct theory. Here, we show that both scaling laws can be deduced from a single network model. Besides the 3/4-law for basal metabolism, the model predicts that maximum metabolic rate scales as M, maximum heart rate as M, and muscular capillary density as M, in agreement with data.

  11. Studies on the establishment of maximum permissible exposure dose for reference Korean

    International Nuclear Information System (INIS)

    Kim, Y.J.; Lee, K.S.; Chun, K.C.; Kim, C.B.; Chung, K.H.; Kim, S.L.; Kim, M.J.

    1981-01-01

    In order to establish the Reference Korean and maximum permissible exposure dose of Reference Korean, for the first year a total of 9,758 males and 7,019 females were surveyed for the height, weight, a body surface area, and a total of 879 individuals of 180 households located in different 30 localities were analyzed for food consumption and a total of radioactive substances (β-ray) contained in food per capita per day. In this report the external and internal exposure dose were also estimated on the basis of data mostly published in other country as well as in Korea in part

  12. 13 CFR 107.845 - Maximum rate of amortization on Loans and Debt Securities.

    Science.gov (United States)

    2010-01-01

    ... ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES Financing of Small Businesses by Licensees Structuring Licensee's Financing of An Eligible Small Business: Terms and Conditions of Financing § 107.845 Maximum... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Maximum rate of amortization on...

  13. [The maximum heart rate in the exercise test: the 220-age formula or Sheffield's table?].

    Science.gov (United States)

    Mesquita, A; Trabulo, M; Mendes, M; Viana, J F; Seabra-Gomes, R

    1996-02-01

    To determine in the maximum cardiac rate in exercise test of apparently healthy individuals may be more properly estimated through 220-age formula (Astrand) or the Sheffield table. Retrospective analysis of clinical history and exercises test of apparently healthy individuals submitted to cardiac check-up. Sequential sampling of 170 healthy individuals submitted to cardiac check-up between April 1988 and September 1992. Comparison of maximum cardiac rate of individuals studied by the protocols of Bruce and modified Bruce, in interrupted exercise test by fatigue, and with the estimated values by the formulae: 220-age versus Sheffield table. The maximum cardiac heart rate is similar with both protocols. This parameter in normal individuals is better predicted by the 220-age formula. The theoretic maximum cardiac heart rate determined by 220-age formula should be recommended for a healthy, and for this reason the Sheffield table has been excluded from our clinical practice.

  14. New England observed and predicted August stream/river temperature maximum daily rate of change points

    Data.gov (United States)

    U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted August stream/river temperature maximum negative rate of change in New England based on a...

  15. High exposure rate hardware ALARA plan

    International Nuclear Information System (INIS)

    Nellesen, A.L.

    1996-10-01

    This as low as reasonably achievable review provides a description of the engineering and administrative controls used to manage personnel exposure and to control contamination levels and airborne radioactivity concentrations. HERH waste is hardware found in the N-Fuel Storage Basin, which has a contact dose rate greater than 1 R/hr and used filters. This waste will be collected in the fuel baskets at various locations in the basins

  16. Maximum production rate optimization for sulphuric acid decomposition process in tubular plug-flow reactor

    International Nuclear Information System (INIS)

    Wang, Chao; Chen, Lingen; Xia, Shaojun; Sun, Fengrui

    2016-01-01

    A sulphuric acid decomposition process in a tubular plug-flow reactor with fixed inlet flow rate and completely controllable exterior wall temperature profile and reactants pressure profile is studied in this paper by using finite-time thermodynamics. The maximum production rate of the aimed product SO 2 and the optimal exterior wall temperature profile and reactants pressure profile are obtained by using nonlinear programming method. Then the optimal reactor with the maximum production rate is compared with the reference reactor with linear exterior wall temperature profile and the optimal reactor with minimum entropy generation rate. The result shows that the production rate of SO 2 of optimal reactor with the maximum production rate has an increase of more than 7%. The optimization of temperature profile has little influence on the production rate while the optimization of reactants pressure profile can significantly increase the production rate. The results obtained may provide some guidelines for the design of real tubular reactors. - Highlights: • Sulphuric acid decomposition process in tubular plug-flow reactor is studied. • Fixed inlet flow rate and controllable temperature and pressure profiles are set. • Maximum production rate of aimed product SO 2 is obtained. • Corresponding optimal temperature and pressure profiles are derived. • Production rate of SO 2 of optimal reactor increases by 7%.

  17. LASER: A Maximum Likelihood Toolkit for Detecting Temporal Shifts in Diversification Rates From Molecular Phylogenies

    Directory of Open Access Journals (Sweden)

    Daniel L. Rabosky

    2006-01-01

    Full Text Available Rates of species origination and extinction can vary over time during evolutionary radiations, and it is possible to reconstruct the history of diversification using molecular phylogenies of extant taxa only. Maximum likelihood methods provide a useful framework for inferring temporal variation in diversification rates. LASER is a package for the R programming environment that implements maximum likelihood methods based on the birth-death process to test whether diversification rates have changed over time. LASER contrasts the likelihood of phylogenetic data under models where diversification rates have changed over time to alternative models where rates have remained constant over time. Major strengths of the package include the ability to detect temporal increases in diversification rates and the inference of diversification parameters under multiple rate-variable models of diversification. The program and associated documentation are freely available from the R package archive at http://cran.r-project.org.

  18. Exercise-induced maximum metabolic rate scaled to body mass by ...

    African Journals Online (AJOL)

    user

    2016-10-27

    Oct 27, 2016 ... maximum aerobic metabolic rate (MMR) is proportional to the fractal extent ... metabolic rate with body mass can be obtained by taking body .... blood takes place. ..... MMR and BMR is that MMR is owing mainly to respiration in skeletal .... the spectra of surface area scaling strategies of cells and organisms:.

  19. Estimation of maximum credible atmospheric radioactivity concentrations and dose rates from nuclear tests

    International Nuclear Information System (INIS)

    Telegadas, K.

    1979-01-01

    A simple technique is presented for estimating maximum credible gross beta air concentrations from nuclear detonations in the atmosphere, based on aircraft sampling of radioactivity following each Chinese nuclear test from 1964 to 1976. The calculated concentration is a function of the total yield and fission yield, initial vertical radioactivity distribution, time after detonation, and rate of horizontal spread of the debris with time. calculated maximum credible concentrations are compared with the highest concentrations measured during aircraft sampling. The technique provides a reasonable estimate of maximum air concentrations from 1 to 10 days after a detonation. An estimate of the whole-body external gamma dose rate corresponding to the maximum credible gross beta concentration is also given. (author)

  20. Maximum Acceptable Vibrato Excursion as a Function of Vibrato Rate in Musicians and Non-musicians

    DEFF Research Database (Denmark)

    Vatti, Marianna; Santurette, Sébastien; Pontoppidan, Niels H.

    2014-01-01

    and, in most listeners, exhibited a peak at medium vibrato rates (5–7 Hz). Large across-subject variability was observed, and no significant effect of musical experience was found. Overall, most listeners were not solely sensitive to the vibrato excursion and there was a listener-dependent rate...... for which larger vibrato excursions were favored. The observed interaction between maximum excursion thresholds and vibrato rate may be due to the listeners’ judgments relying on cues provided by the rate of frequency changes (RFC) rather than excursion per se. Further studies are needed to evaluate......Human vibrato is mainly characterized by two parameters: vibrato extent and vibrato rate. These parameters have been found to exhibit an interaction both in physical recordings of singers’ voices and in listener’s preference ratings. This study was concerned with the way in which the maximum...

  1. On the equivalence between the minimum entropy generation rate and the maximum conversion rate for a reactive system

    International Nuclear Information System (INIS)

    Bispo, Heleno; Silva, Nilton; Brito, Romildo; Manzi, João

    2013-01-01

    Highlights: • Minimum entropy generation (MEG) principle improved the reaction performance. • MEG rate and the maximum conversion equivalence have been analyzed. • Temperature and residence time are used to the domain establishment of MEG. • Satisfying the temperature and residence time relationship results a optimal performance. - Abstract: The analysis of the equivalence between the minimum entropy generation (MEG) rate and the maximum conversion rate for a reactive system is the main purpose of this paper. While being used as a strategy of optimization, the minimum entropy production was applied to the production of propylene glycol in a Continuous Stirred-Tank Reactor (CSTR) with a view to determining the best operating conditions, and under such conditions, a high conversion rate was found. The effects of the key variables and restrictions on the validity domain of MEG were investigated, which raises issues that are included within a broad discussion. The results from simulations indicate that from the chemical reaction standpoint a maximum conversion rate can be considered as equivalent to MEG. Such a result can be clearly explained by examining the classical Maxwell–Boltzmann distribution, where the molecules of the reactive system under the condition of the MEG rate present a distribution of energy with reduced dispersion resulting in a better quality of collision between molecules with a higher conversion rate

  2. Low reproducibility of maximum urinary flow rate determined by portable flowmetry

    NARCIS (Netherlands)

    Sonke, G. S.; Kiemeney, L. A.; Verbeek, A. L.; Kortmann, B. B.; Debruyne, F. M.; de la Rosette, J. J.

    1999-01-01

    To evaluate the reproducibility in maximum urinary flow rate (Qmax) in men with lower urinary tract symptoms (LUTSs) and to determine the number of flows needed to obtain a specified reliability in mean Qmax, 212 patients with LUTSs (mean age, 62 years) referred to the University Hospital Nijmegen,

  3. 19 CFR 212.07 - Rulemaking on maximum rates for attorney fees.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Rulemaking on maximum rates for attorney fees. 212.07 Section 212.07 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT General Provisions...

  4. 7 CFR 4290.845 - Maximum rate of amortization on Loans and Debt Securities.

    Science.gov (United States)

    2010-01-01

    ...) RURAL BUSINESS-COOPERATIVE SERVICE AND RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE RURAL BUSINESS INVESTMENT COMPANY (âRBICâ) PROGRAM Financing of Enterprises by RBICs Structuring Rbic Financing of Eligible Enterprises-Types of Financings § 4290.845 Maximum rate of amortization on Loans and Debt Securities. The...

  5. 30 CFR 75.601-3 - Short circuit protection; dual element fuses; current ratings; maximum values.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection; dual element fuses... Trailing Cables § 75.601-3 Short circuit protection; dual element fuses; current ratings; maximum values. Dual element fuses having adequate current-interrupting capacity shall meet the requirements for short...

  6. Disentangling the effects of alternation rate and maximum run length on judgments of randomness

    Directory of Open Access Journals (Sweden)

    Sabine G. Scholl

    2011-08-01

    Full Text Available Binary sequences are characterized by various features. Two of these characteristics---alternation rate and run length---have repeatedly been shown to influence judgments of randomness. The two characteristics, however, have usually been investigated separately, without controlling for the other feature. Because the two features are correlated but not identical, it seems critical to analyze their unique impact, as well as their interaction, so as to understand more clearly what influences judgments of randomness. To this end, two experiments on the perception of binary sequences orthogonally manipulated alternation rate and maximum run length (i.e., length of the longest run within the sequence. Results show that alternation rate consistently exerts a unique effect on judgments of randomness, but that the effect of alternation rate is contingent on the length of the longest run within the sequence. The effect of maximum run length was found to be small and less consistent. Together, these findings extend prior randomness research by integrating literature from the realms of perception, categorization, and prediction, as well as by showing the unique and joint effects of alternation rate and maximum run length on judgments of randomness.

  7. Conifers in cold environments synchronize maximum growth rate of tree-ring formation with day length.

    Science.gov (United States)

    Rossi, Sergio; Deslauriers, Annie; Anfodillo, Tommaso; Morin, Hubert; Saracino, Antonio; Motta, Renzo; Borghetti, Marco

    2006-01-01

    Intra-annual radial growth rates and durations in trees are reported to differ greatly in relation to species, site and environmental conditions. However, very similar dynamics of cambial activity and wood formation are observed in temperate and boreal zones. Here, we compared weekly xylem cell production and variation in stem circumference in the main northern hemisphere conifer species (genera Picea, Pinus, Abies and Larix) from 1996 to 2003. Dynamics of radial growth were modeled with a Gompertz function, defining the upper asymptote (A), x-axis placement (beta) and rate of change (kappa). A strong linear relationship was found between the constants beta and kappa for both types of analysis. The slope of the linear regression, which corresponds to the time at which maximum growth rate occurred, appeared to converge towards the summer solstice. The maximum growth rate occurred around the time of maximum day length, and not during the warmest period of the year as previously suggested. The achievements of photoperiod could act as a growth constraint or a limit after which the rate of tree-ring formation tends to decrease, thus allowing plants to safely complete secondary cell wall lignification before winter.

  8. Does Interest rate Exposure explain the Low-Volatility Anomaly?

    NARCIS (Netherlands)

    Driessen, Joost; Kuiper, Ivo; Beilo, R.

    We show that part of the outperformance of low-volatility stocks can be explained by a premium for interest rate exposure. Low-volatility stock portfolios have negative exposure to interest rates, whereas the more volatile stocks have positive exposure. Incorporating an interest rate premium

  9. Application of maximum values for radiation exposure and principles for the calculation of radiation dose

    International Nuclear Information System (INIS)

    2000-01-01

    The guide sets out the mathematical definitions and principles involved in the calculation of the equivalent dose and the effective dose, and the instructions concerning the application of the maximum values of these quantities. further, for monitoring the dose caused by internal radiation, the guide defines the limits derived from annual dose limits (the Annual Limit on Intake and the Derived Air Concentration). Finally, the guide defines the operational quantities to be used in estimating the equivalent dose and the effective dose, and also sets out the definitions of some other quantities and concepts to be used in monitoring radiation exposure. The guide does not include the calculation of patient doses carried out for the purposes of quality assurance

  10. Application of maximum values for radiation exposure and principles for the calculation of radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The guide sets out the mathematical definitions and principles involved in the calculation of the equivalent dose and the effective dose, and the instructions concerning the application of the maximum values of these quantities. further, for monitoring the dose caused by internal radiation, the guide defines the limits derived from annual dose limits (the Annual Limit on Intake and the Derived Air Concentration). Finally, the guide defines the operational quantities to be used in estimating the equivalent dose and the effective dose, and also sets out the definitions of some other quantities and concepts to be used in monitoring radiation exposure. The guide does not include the calculation of patient doses carried out for the purposes of quality assurance.

  11. Determination of Measurement Points in Urban Environments for Assessment of Maximum Exposure to EMF Associated with a Base Station

    Directory of Open Access Journals (Sweden)

    Agostinho Linhares

    2014-01-01

    Full Text Available A base station (BS antenna operates in accordance with the established exposure limits if the values of electromagnetic fields (EMF measured in points of maximum exposure are below these limits. In the case of BS in open areas, the maximum exposure to EMF probably occurs in the antenna’s boresight direction, from a few tens to a few hundred meters away. This is not a typical scenery for urban environments. However, in the line of sight (LOS situation, the region of maximum exposure can still be analytically estimated with good results. This paper presents a methodology for the choice of measurement points in urban areas in order to assess compliance with the limits for exposure to EMF.

  12. Rate maximum calculation of Dpa in CNA-II pressure vessel

    International Nuclear Information System (INIS)

    Mascitti, J. A

    2012-01-01

    The maximum dpa rate was calculated for the reactor in the following state: fresh fuel, no Xenon, a Boron concentration of 15.3 ppm, critical state, its control rods in the criticality position, hot, at full power (2160 MW). It was determined that the maximum dpa rate under such conditions is 3.54(2)x10 12 s -1 and it is located in the positions corresponding to θ=210 o in the azimuthal direction, and z=20 cm and -60 cm respectively in the axial direction, considering the calculation mesh centered at half height of the fuel element (FE) active length. The dpa rate spectrum was determined as well as the contribution to it for 4 energy groups: a thermal group, two epithermal groups and a fast one. The maximum dpa rate considering the photo-neutrons production from (γ, n) reaction in the heavy water of coolant and moderator was 3.93(4)x10 12 s -1 that is 11% greater than the obtained without photo-neutrons. This verified significant difference between both cases, suggest that photo-neutrons in large heavy water reactors such as CNA-II should not be ignored. The maximum DPA rate in the first mm of the reactor pressure vessel was calculated too and it was obtained a value of 4.22(6)x10 12 s -1 . It should be added that the calculation was carried out with the reactor complete accurate model, with no approximations in spatial or energy variables. Each value has, between parentheses, a percentage relative error representing the statistical uncertainty due to the probabilistic Monte Carlo method used to estimate it. More representative values may be obtained with this method if equilibrium burn-up distribution is used (author)

  13. Biological bases of the maximum permissible exposure levels of the UK laser standard BS 4803: 1983

    International Nuclear Information System (INIS)

    McKinlay, A.F.; Harlen, F.

    1983-10-01

    The use of lasers has increased greatly over the past 15 years or so, to the extent that they are now used routinely in many occupational and public situations. There has been an increasing awareness of the potential hazards presented by lasers and substantial efforts have been made to formulate safety standards. In the UK the relevant Safety Standard is the British Standards Institution Standard BS 4803. This Standard was originally published in 1972 and a revision has recently been published (BS 4803: 1983). The revised standard has been developed using the American National Standards Institute Standard, ANSI Z136.1 (1973 onwards), as a model. In other countries, national standards have been similarly formulated, resulting in a large measure of international agreement through participation in the work of the International Electrotechnical Commission (IEC). The bases of laser safety standards are biophysical data on threshold injury effects, particularly on the retina, and the development of theoretical models of damage mechanisms. This report deals in some detail with the mechanisms of injury from over exposure to optical radiations, in particular with the dependency of the type and degree of damage on wavelength, image size and pulse duration. The maximum permissible exposure levels recommended in BS 4803: 1983 are compared with published data for damage thresholds and the adequacy of the standard is discussed. (author)

  14. Fast maximum likelihood estimation of mutation rates using a birth-death process.

    Science.gov (United States)

    Wu, Xiaowei; Zhu, Hongxiao

    2015-02-07

    Since fluctuation analysis was first introduced by Luria and Delbrück in 1943, it has been widely used to make inference about spontaneous mutation rates in cultured cells. Under certain model assumptions, the probability distribution of the number of mutants that appear in a fluctuation experiment can be derived explicitly, which provides the basis of mutation rate estimation. It has been shown that, among various existing estimators, the maximum likelihood estimator usually demonstrates some desirable properties such as consistency and lower mean squared error. However, its application in real experimental data is often hindered by slow computation of likelihood due to the recursive form of the mutant-count distribution. We propose a fast maximum likelihood estimator of mutation rates, MLE-BD, based on a birth-death process model with non-differential growth assumption. Simulation studies demonstrate that, compared with the conventional maximum likelihood estimator derived from the Luria-Delbrück distribution, MLE-BD achieves substantial improvement on computational speed and is applicable to arbitrarily large number of mutants. In addition, it still retains good accuracy on point estimation. Published by Elsevier Ltd.

  15. Methodological aspects of crossover and maximum fat-oxidation rate point determination.

    Science.gov (United States)

    Michallet, A-S; Tonini, J; Regnier, J; Guinot, M; Favre-Juvin, A; Bricout, V; Halimi, S; Wuyam, B; Flore, P

    2008-11-01

    Indirect calorimetry during exercise provides two metabolic indices of substrate oxidation balance: the crossover point (COP) and maximum fat oxidation rate (LIPOXmax). We aimed to study the effects of the analytical device, protocol type and ventilatory response on variability of these indices, and the relationship with lactate and ventilation thresholds. After maximum exercise testing, 14 relatively fit subjects (aged 32+/-10 years; nine men, five women) performed three submaximum graded tests: one was based on a theoretical maximum power (tMAP) reference; and two were based on the true maximum aerobic power (MAP). Gas exchange was measured concomitantly using a Douglas bag (D) and an ergospirometer (E). All metabolic indices were interpretable only when obtained by the D reference method and MAP protocol. Bland and Altman analysis showed overestimation of both indices with E versus D. Despite no mean differences between COP and LIPOXmax whether tMAP or MAP was used, the individual data clearly showed disagreement between the two protocols. Ventilation explained 10-16% of the metabolic index variations. COP was correlated with ventilation (r=0.96, P<0.01) and the rate of increase in blood lactate (r=0.79, P<0.01), and LIPOXmax correlated with the ventilation threshold (r=0.95, P<0.01). This study shows that, in fit healthy subjects, the analytical device, reference used to build the protocol and ventilation responses affect metabolic indices. In this population, and particularly to obtain interpretable metabolic indices, we recommend a protocol based on the true MAP or one adapted to include the transition from fat to carbohydrate. The correlation between metabolic indices and lactate/ventilation thresholds suggests that shorter, classical maximum progressive exercise testing may be an alternative means of estimating these indices in relatively fit subjects. However, this needs to be confirmed in patients who have metabolic defects.

  16. The Exchange Rate Exposure of Danish Non-Financial Companies

    DEFF Research Database (Denmark)

    Aabo, Tom

    1999-01-01

    of the extra-market exchange rate exposure of individual companies. As such, only a minority of companies has significant exposures when using the effective Danish exchange rate in an OLS regression analysis while half of the companies have significant exposures when using five main exchange rates. A GARCH(1......A shortcut to measuring exchange rate exposure at the company level can be to exploit the information content in the stock prices. A regression analysis is conducted for the main Danish non-financial companies. The use of one all-comprising exchange rate indicator fails to address the complexity......,1) regression analysis is shown to further improve the detection of exposures. The success in identifying exposures for Danish non-financial companies is in contrast to earlier US studies and is relevant in a European context....

  17. Clinical evaluation of a simple uroflowmeter for categorization of maximum urinary flow rate

    Directory of Open Access Journals (Sweden)

    Simon Pridgeon

    2007-01-01

    Full Text Available Objective: To evaluate the accuracy and diagnostic usefulness of a disposable flowmeter consisting of a plastic funnel with a spout divided into three chambers. Materials and Methods: Men with lower urinary tract symptoms (LUTS voided sequentially into a standard flowmeter and the funnel device recording maximum flow rate (Q max and voided volume (V void . The device was precalibrated such that filling of the bottom, middle and top chambers categorized maximum input flows as 15 ml s -1 respectively. Subjects who agreed to use the funnel device at home obtained readings of flow category and V void twice daily for seven days. Results: A single office reading in 46 men using the device showed good agreement with standard measurement of Q max for V void > 150 ml (Kappa = 0.68. All 14 men whose void reached the top chamber had standard Q max > 15 ml s -1 (PPV = 100%, NPV = 72% whilst eight of 12 men whose void remained in the bottom chamber had standard Q max < 10 ml s -1 (PPV = 70%, NPV = 94%. During multiple home use by 14 men the device showed moderate repeatability (Kappa = 0.58 and correctly categorized Q max in comparison to standard measurement for 12 (87% men. Conclusions: This study suggests that the device has sufficient accuracy and reliability for initial flow rate assessment in men with LUTS. The device can provide a single measurement or alternatively multiple home measurements to categorize men with Q max < 15 ml s -1 .

  18. Maximum heart rate in brown trout (Salmo trutta fario) is not limited by firing rate of pacemaker cells.

    Science.gov (United States)

    Haverinen, Jaakko; Abramochkin, Denis V; Kamkin, Andre; Vornanen, Matti

    2017-02-01

    Temperature-induced changes in cardiac output (Q̇) in fish are largely dependent on thermal modulation of heart rate (f H ), and at high temperatures Q̇ collapses due to heat-dependent depression of f H This study tests the hypothesis that firing rate of sinoatrial pacemaker cells sets the upper thermal limit of f H in vivo. To this end, temperature dependence of action potential (AP) frequency of enzymatically isolated pacemaker cells (pacemaker rate, f PM ), spontaneous beating rate of isolated sinoatrial preparations (f SA ), and in vivo f H of the cold-acclimated (4°C) brown trout (Salmo trutta fario) were compared under acute thermal challenges. With rising temperature, f PM steadily increased because of the acceleration of diastolic depolarization and shortening of AP duration up to the break point temperature (T BP ) of 24.0 ± 0.37°C, at which point the electrical activity abruptly ceased. The maximum f PM at T BP was much higher [193 ± 21.0 beats per minute (bpm)] than the peak f SA (94.3 ± 6.0 bpm at 24.1°C) or peak f H (76.7 ± 2.4 at 15.7 ± 0.82°C) (P brown trout in vivo. Copyright © 2017 the American Physiological Society.

  19. Improving Bayesian credibility intervals for classifier error rates using maximum entropy empirical priors.

    Science.gov (United States)

    Gustafsson, Mats G; Wallman, Mikael; Wickenberg Bolin, Ulrika; Göransson, Hanna; Fryknäs, M; Andersson, Claes R; Isaksson, Anders

    2010-06-01

    Successful use of classifiers that learn to make decisions from a set of patient examples require robust methods for performance estimation. Recently many promising approaches for determination of an upper bound for the error rate of a single classifier have been reported but the Bayesian credibility interval (CI) obtained from a conventional holdout test still delivers one of the tightest bounds. The conventional Bayesian CI becomes unacceptably large in real world applications where the test set sizes are less than a few hundred. The source of this problem is that fact that the CI is determined exclusively by the result on the test examples. In other words, there is no information at all provided by the uniform prior density distribution employed which reflects complete lack of prior knowledge about the unknown error rate. Therefore, the aim of the study reported here was to study a maximum entropy (ME) based approach to improved prior knowledge and Bayesian CIs, demonstrating its relevance for biomedical research and clinical practice. It is demonstrated how a refined non-uniform prior density distribution can be obtained by means of the ME principle using empirical results from a few designs and tests using non-overlapping sets of examples. Experimental results show that ME based priors improve the CIs when employed to four quite different simulated and two real world data sets. An empirically derived ME prior seems promising for improving the Bayesian CI for the unknown error rate of a designed classifier. Copyright 2010 Elsevier B.V. All rights reserved.

  20. Maximum type 1 error rate inflation in multiarmed clinical trials with adaptive interim sample size modifications.

    Science.gov (United States)

    Graf, Alexandra C; Bauer, Peter; Glimm, Ekkehard; Koenig, Franz

    2014-07-01

    Sample size modifications in the interim analyses of an adaptive design can inflate the type 1 error rate, if test statistics and critical boundaries are used in the final analysis as if no modification had been made. While this is already true for designs with an overall change of the sample size in a balanced treatment-control comparison, the inflation can be much larger if in addition a modification of allocation ratios is allowed as well. In this paper, we investigate adaptive designs with several treatment arms compared to a single common control group. Regarding modifications, we consider treatment arm selection as well as modifications of overall sample size and allocation ratios. The inflation is quantified for two approaches: a naive procedure that ignores not only all modifications, but also the multiplicity issue arising from the many-to-one comparison, and a Dunnett procedure that ignores modifications, but adjusts for the initially started multiple treatments. The maximum inflation of the type 1 error rate for such types of design can be calculated by searching for the "worst case" scenarios, that are sample size adaptation rules in the interim analysis that lead to the largest conditional type 1 error rate in any point of the sample space. To show the most extreme inflation, we initially assume unconstrained second stage sample size modifications leading to a large inflation of the type 1 error rate. Furthermore, we investigate the inflation when putting constraints on the second stage sample sizes. It turns out that, for example fixing the sample size of the control group, leads to designs controlling the type 1 error rate. © 2014 The Author. Biometrical Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Maximum permissible body burdens and maximum permissible concentrations of radionuclides in air and in water for occupational exposure. Recommendations of the National Committee on Radiation Protection. Handbook 69

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1959-06-05

    The present Handbook and its predecessors stem from the Second International Congress of Radiology, held in Stockholm in 1928. At that time, under the auspices of the Congress, the International Commission on Radiological Protection (ICRP) was organized to deal initially with problems of X-ray protection and later with radioactivity protection. At that time 'permissible' doses of X-rays were estimated primarily in terms of exposures which produced erythema, the amount of exposure which would produce a defined reddening of the skin. Obviously a critical problem in establishing criteria for radiation protection was one of developing useful standards and techniques of physical measurement. For this reason two of the organizations in this country with a major concern for X-ray protection, the American Roentgen Ray Society and the Radiology Society of North America, suggested that the National Bureau of Standards assume responsibility for organizing representative experts to deal with the problem. Accordingly, early in 1929, an Advisory Committee on X-ray and Radium Protection was organized to develop recommendations on the protection problem within the United States and to formulate United States points of view for presentation to the International Commission on Radiological Protection. The organization of the U.S. Advisory Committee included experts from both the medical and physical science fields. The recommendations of this Handbook take into consideration the NCRP statement entitled 'Maximum Permissible Radiation Exposures to Man', published as an addendum to Handbook 59 on April 15, 1958. As noted above this study was carried out jointly by the ICRP and the NCRP, and the complete report is more extensive than the material contained in this Handbook.

  2. Maximum permissible body burdens and maximum permissible concentrations of radionuclides in air and in water for occupational exposure. Recommendations of the National Committee on Radiation Protection. Handbook 69

    International Nuclear Information System (INIS)

    1959-01-01

    The present Handbook and its predecessors stem from the Second International Congress of Radiology, held in Stockholm in 1928. At that time, under the auspices of the Congress, the International Commission on Radiological Protection (ICRP) was organized to deal initially with problems of X-ray protection and later with radioactivity protection. At that time 'permissible' doses of X-rays were estimated primarily in terms of exposures which produced erythema, the amount of exposure which would produce a defined reddening of the skin. Obviously a critical problem in establishing criteria for radiation protection was one of developing useful standards and techniques of physical measurement. For this reason two of the organizations in this country with a major concern for X-ray protection, the American Roentgen Ray Society and the Radiology Society of North America, suggested that the National Bureau of Standards assume responsibility for organizing representative experts to deal with the problem. Accordingly, early in 1929, an Advisory Committee on X-ray and Radium Protection was organized to develop recommendations on the protection problem within the United States and to formulate United States points of view for presentation to the International Commission on Radiological Protection. The organization of the U.S. Advisory Committee included experts from both the medical and physical science fields. The recommendations of this Handbook take into consideration the NCRP statement entitled 'Maximum Permissible Radiation Exposures to Man', published as an addendum to Handbook 59 on April 15, 1958. As noted above this study was carried out jointly by the ICRP and the NCRP, and the complete report is more extensive than the material contained in this Handbook

  3. Petroleum production at Maximum Efficient Rate Naval Petroleum Reserve No. 1 (Elk Hills), Kern County, California

    International Nuclear Information System (INIS)

    1993-07-01

    This document provides an analysis of the potential impacts associated with the proposed action, which is continued operation of Naval Petroleum Reserve No. I (NPR-1) at the Maximum Efficient Rate (MER) as authorized by Public law 94-258, the Naval Petroleum Reserves Production Act of 1976 (Act). The document also provides a similar analysis of alternatives to the proposed action, which also involve continued operations, but under lower development scenarios and lower rates of production. NPR-1 is a large oil and gas field jointly owned and operated by the federal government and Chevron U.SA Inc. (CUSA) pursuant to a Unit Plan Contract that became effective in 1944; the government's interest is approximately 78% and CUSA's interest is approximately 22%. The government's interest is under the jurisdiction of the United States Department of Energy (DOE). The facility is approximately 17,409 acres (74 square miles), and it is located in Kern County, California, about 25 miles southwest of Bakersfield and 100 miles north of Los Angeles in the south central portion of the state. The environmental analysis presented herein is a supplement to the NPR-1 Final Environmental Impact Statement of that was issued by DOE in 1979 (1979 EIS). As such, this document is a Supplemental Environmental Impact Statement (SEIS)

  4. Maximum Evaporation Rates of Water Droplets Approaching Obstacles in the Atmosphere Under Icing Conditions

    Science.gov (United States)

    Lowell, H. H.

    1953-01-01

    When a closed body or a duct envelope moves through the atmosphere, air pressure and temperature rises occur ahead of the body or, under ram conditions, within the duct. If cloud water droplets are encountered, droplet evaporation will result because of the air-temperature rise and the relative velocity between the droplet and stagnating air. It is shown that the solution of the steady-state psychrometric equation provides evaporation rates which are the maximum possible when droplets are entrained in air moving along stagnation lines under such conditions. Calculations are made for a wide variety of water droplet diameters, ambient conditions, and flight Mach numbers. Droplet diameter, body size, and Mach number effects are found to predominate, whereas wide variation in ambient conditions are of relatively small significance in the determination of evaporation rates. The results are essentially exact for the case of movement of droplets having diameters smaller than about 30 microns along relatively long ducts (length at least several feet) or toward large obstacles (wings), since disequilibrium effects are then of little significance. Mass losses in the case of movement within ducts will often be significant fractions (one-fifth to one-half) of original droplet masses, while very small droplets within ducts will often disappear even though the entraining air is not fully stagnated. Wing-approach evaporation losses will usually be of the order of several percent of original droplet masses. Two numerical examples are given of the determination of local evaporation rates and total mass losses in cases involving cloud droplets approaching circular cylinders along stagnation lines. The cylinders chosen were of 3.95-inch (10.0+ cm) diameter and 39.5-inch 100+ cm) diameter. The smaller is representative of icing-rate measurement cylinders, while with the larger will be associated an air-flow field similar to that ahead of an airfoil having a leading-edge radius

  5. Long-term reduction in infrared autofluorescence caused by infrared light below the maximum permissible exposure.

    Science.gov (United States)

    Masella, Benjamin D; Williams, David R; Fischer, William S; Rossi, Ethan A; Hunter, Jennifer J

    2014-05-20

    Many retinal imaging instruments use infrared wavelengths to reduce the risk of light damage. However, we have discovered that exposure to infrared illumination causes a long-lasting reduction in infrared autofluorescence (IRAF). We have characterized the dependence of this effect on radiant exposure and investigated its origin. A scanning laser ophthalmoscope was used to obtain IRAF images from two macaques before and after exposure to 790-nm light (15-450 J/cm(2)). Exposures were performed with either raster-scanning or uniform illumination. Infrared autofluorescence images also were obtained in two humans exposed to 790-nm light in a separate study. Humans were assessed with direct ophthalmoscopy, Goldmann visual fields, multifocal ERG, and photopic microperimetry to determine whether these measures revealed any effects in the exposed locations. A significant decrease in IRAF after exposure to infrared light was seen in both monkeys and humans. In monkeys, the magnitude of this reduction increased with retinal radiant exposure. Partial recovery was seen at 1 month, with full recovery within 21 months. Consistent with a photochemical origin, IRAF decreases caused by either raster-scanning or uniform illumination were not significantly different. We were unable to detect any effect of the light exposure with any measure other than IRAF imaging. We cannot exclude the possibility that changes could be detected with more sensitive tests or longer follow-up. This long-lasting effect of infrared illumination in both humans and monkeys occurs at exposure levels four to five times below current safety limits. The photochemical basis for this phenomenon remains unknown. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  6. New England observed and predicted August stream/river temperature maximum positive daily rate of change points

    Data.gov (United States)

    U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted August stream/river temperature maximum positive daily rate of change in New England based on a...

  7. New England observed and predicted July stream/river temperature maximum positive daily rate of change points

    Data.gov (United States)

    U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted July stream/river temperature maximum positive daily rate of change in New England based on a...

  8. New England observed and predicted July maximum negative stream/river temperature daily rate of change points

    Data.gov (United States)

    U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted July stream/river temperature maximum negative daily rate of change in New England based on a...

  9. Monitoring method for an ambient Gamma exposure rate and its measurement analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mo Sung [Cheongju Univ., Cheongju (Korea, Republic of); Woo, Jong Kwan [University of Seoul, Seoul (Korea, Republic of)

    2006-12-15

    Daily and seasonal variations of the ambient gamma ray exposure rates were measured by using a pressurized ion chamber from January 2003 to December 2005 in the Cheongju Regional Radiation Monitoring Post and the patterns of the distributions were studied. The annual average of the daily variation of the exposure rate was {approx}0.17 {mu}R/h. The exposure rate was found to be maximum during 8:00 am to 9:00 am and minimum during 8:00 pm to 10:00 pm. For the annual data, the exposure rate was the minimum during the month of February. The exposure rate increased from February to mid-October (except during the period from May to July with no change) and decreased from October to February. The seasonal variation was found to be about 1 {mu}R/h. Most of the measured values (96%) of the exposure rates fell under the normal distribution with a deviation of less than 4.8% and the remaining 4% had large fluctuations caused mainly by the rainfalls.

  10. Design And Measurement Of Radiation Exposure Rates At An X-Ray Diagnostic Radiological Unit

    International Nuclear Information System (INIS)

    Tito-Sutjipto

    2003-01-01

    Every radiation employees suffers radiation exposure risk while doing his job. It is important therefore to investigate the occupational health and safety of radiation employees on its relationship with the design and measurement of radiation exposure rates at an X-ray diagnostic radiological unit in this work, a case study was held on the radiological unit at BP-4 Yogyakarta for patient diagnostics, This research armed to investigate the relationship between the design of radiological unit for X-ray diagnostics and the location of the X-ray machine, based on the distance variable and radiation exposure rate during patient diagnostics. This was performed using radiological unit design data for X-ray diagnostics and the measurement of radiation exposure rates throughout patient diagnostics. The design data can then be used for determining the requirement of primary and secondary shielding materials for radiological unit as well as a calculation basis of radiation exposure rates during patient diagnostics. From the result of the research, it can be concluded that from the occupational health and safety point of view, radiation exposure around the X-ray machines are fairly good, both for the shielding materials in each X-ray room and the radiation exposures received by the workers, because they are far beyond the maximum permittable average limit (16.67 m R/days). (author)

  11. Sun Protection Preferences and Behaviors among Young Adult Males during Maximum Ultraviolet Radiation Exposure Activities

    Science.gov (United States)

    Wickenheiser, Marilyn; Baker, Mary Kate; Gaber, Rikki; Blatt, Hanz; Robinson, June K.

    2013-01-01

    This study explores sun protection attitudes, preferences, and behaviors among young adult males participating in an open-field activity with extreme ultraviolet radiation exposure. Male drum corps members (n = 137) responded to survey questions regarding their behavior and willingness to engage in sun protection and barriers to sunscreen usage. A subset of members (n = 31) participated in cognitive interviews exploring various sunscreen products and intervention techniques. Participants were knowledgeable about health risks and protection benefits regarding sun exposure. Generally, males had positive attitudes and normative beliefs about using sunscreen. A barrier to sunscreen re-application was lack of adequate time to reapply sunscreen during the open field activity. Males preferred a towelette application method, but were unfamiliar with its efficacy and proper use. Thus, they were more likely to use the more familiar sunscreen spray. To increase sun protection behaviors and lower skin cancer risk for males participating in open-field activities, breaks must be allotted every 2 h and have sufficient time to allow sunscreen application. Future development and research into delivery systems that rapidly and evenly apply sunscreen may help lower exposure in this population. PMID:23912201

  12. Sun Protection Preferences and Behaviors among Young Adult Males during Maximum Ultraviolet Radiation Exposure Activities

    Directory of Open Access Journals (Sweden)

    June K. Robinson

    2013-07-01

    Full Text Available This study explores sun protection attitudes, preferences, and behaviors among young adult males participating in an open-field activity with extreme ultraviolet radiation exposure. Male drum corps members (n = 137 responded to survey questions regarding their behavior and willingness to engage in sun protection and barriers to sunscreen usage. A subset of members (n = 31 participated in cognitive interviews exploring various sunscreen products and intervention techniques. Participants were knowledgeable about health risks and protection benefits regarding sun exposure. Generally, males had positive attitudes and normative beliefs about using sunscreen. A barrier to sunscreen re-application was lack of adequate time to reapply sunscreen during the open field activity. Males preferred a towelette application method, but were unfamiliar with its efficacy and proper use. Thus, they were more likely to use the more familiar sunscreen spray. To increase sun protection behaviors and lower skin cancer risk for males participating in open-field activities, breaks must be allotted every 2 h and have sufficient time to allow sunscreen application. Future development and research into delivery systems that rapidly and evenly apply sunscreen may help lower exposure in this population.

  13. Prediction of gamma exposure rates in large nuclear craters

    Energy Technology Data Exchange (ETDEWEB)

    Tami, Thomas M; Day, Walter C [U.S. Army Engineer Nuclear Cratering Group, Lawrence Radiation Laboratory, Livermore, CA (United States)

    1970-05-15

    In many civil engineering applications of nuclear explosives there is the need to reenter the crater and lip area as soon as possible after the detonation to carry out conventional construction activities. These construction activities, however, must be delayed until the gamma dose rate, or exposure rate, in and around the crater decays to acceptable levels. To estimate the time of reentry for post-detonation construction activities, the exposure rate in the crater and lip areas must be predicted as a function of time after detonation. An accurate prediction permits a project planner to effectively schedule post-detonation activities.

  14. Asymmetric Exchange Rate Exposure - Research in Southeast Asian Countries

    Directory of Open Access Journals (Sweden)

    Minh Thi Hong Le

    2017-04-01

    Full Text Available The study aims to analyse the impact of exchange rate exposure on stock returns in six countries representative of Southeast Asia, including Indonesia, Malaysia, Philippines, Singapore, Thailand and Vietnam from 2009 to 2014. Both nominal and real exchange rates are taken into account for evaluating exchange rate fluctuations via panel data. In order to achieve this goal, a panel regressive estimation approach is proposed in which a GLS model is firstly used to treat heteroscedasticity in the panel data and, then, a GMM estimator is employed to ensure the consistency of the estimates. The results point out that the exchange rate exposure of these countries is asymmetric. At market level, for a rise in the exchange rate (or local currency depreciates, the average stock returns tend to decrease. However, due to the favourable impact of currency depreciation on the net export position, the reduction speed of stock returns is faster than the rising speed of the exchange rate.

  15. Asymmetric Exchange Rate Exposure - Research in Southeast Asian Countries

    OpenAIRE

    Minh Thi Hong Le; Ha Thi Cam Huynh; Hong Thi Thu Dinh

    2017-01-01

    The study aims to analyse the impact of exchange rate exposure on stock returns in six countries representative of Southeast Asia, including Indonesia, Malaysia, Philippines, Singapore, Thailand and Vietnam from 2009 to 2014. Both nominal and real exchange rates are taken into account for evaluating exchange rate fluctuations via panel data. In order to achieve this goal, a panel regressive estimation approach is proposed in which a GLS model is firstly used to treat heteroscedasticity in the...

  16. Digital Intraoral Imaging Re-Exposure Rates of Dental Students.

    Science.gov (United States)

    Senior, Anthea; Winand, Curtis; Ganatra, Seema; Lai, Hollis; Alsulfyani, Noura; Pachêco-Pereira, Camila

    2018-01-01

    A guiding principle of radiation safety is ensuring that radiation dosage is as low as possible while yielding the necessary diagnostic information. Intraoral images taken with conventional dental film have a higher re-exposure rate when taken by dental students compared to experienced staff. The aim of this study was to examine the prevalence of and reasons for re-exposure of digital intraoral images taken by third- and fourth-year dental students in a dental school clinic. At one dental school in Canada, the total number of intraoral images taken by third- and fourth-year dental students, re-exposures, and error descriptions were extracted from patient clinical records for an eight-month period (September 2015 to April 2016). The data were categorized to distinguish between digital images taken with solid-state sensors or photostimulable phosphor plates (PSP). The results showed that 9,397 intraoral images were made, and 1,064 required re-exposure. The most common error requiring re-exposure for bitewing images was an error in placement of the receptor too far mesially or distally (29% for sensors and 18% for PSP). The most common error requiring re-exposure for periapical images was inadequate capture of the periapical area (37% for sensors and 6% for PSP). A retake rate of 11% was calculated, and the common technique errors causing image deficiencies were identified. Educational intervention can now be specifically designed to reduce the retake rate and radiation dose for future patients.

  17. A firm-specific exposure analyis of the exchange-rate exposure of Dutch firms

    NARCIS (Netherlands)

    de Jong, A.; Ligterink, J.; Macrae, V.

    2006-01-01

    We examine the relationship between exchange-rate changes and stock returns for a sample of Dutch firms over 1994-1998. We find that over 50 per cent of the firms are significantly exposed to exchange-rate risk. Furthermore, all firms with significant exchange-rate exposure benefit from a

  18. Exchange Rate Exposure Management: "Speculation" in Non-Financial Companies

    DEFF Research Database (Denmark)

    Aabo, Tom

    "Speculation" in non-financial companies in relation to exchange rate exposure management constitutes one of the contributing factors behind corporate (or more widespread) crises. Deviations from benchmark positions constitute speculation. An empirical study of Danish non-financial companies finds...... that the larger the company (ability) and the larger its relative sale on foreign markets (relevance), the more likely the company will be to benchmark its exchange rate exposures. However, at the same time the very same factors (size and foreign sale) lead to more extensive speculation. Financial solvency (value...

  19. E-Commerce and Exchange Rate Exposure Management

    DEFF Research Database (Denmark)

    Aabo, Tom

    2001-01-01

    The aim of this paper is to address the impact of E-commerce on the balance between real hedging and financial hedging in the context of exchange rate exposure management in non-financial companies. A cross-case study of industrial companies highlights the inadequacy in taking a partial and static...... financial approach when managing exchange rate exposures. The paper argues that the emergence of E-commerce - by reducing the cost of obtaining, analyzing and allocating information - affects the dynamics of the markets and the dynamics of the company in such a way that a general tilt towards real hedging...

  20. Calculation of gamma ray exposure rates from uranium ore bodies

    International Nuclear Information System (INIS)

    Thomson, J.E.; Wilson, O.J.

    1980-02-01

    The planning of operations associated with uranium mines often requires that estimates be made of the exposure rates from various ore bodies. A straight-forward method of calculating the exposure rate from an arbitrarily shaped body is presented. Parameters for the calculation are evaluated under the assumption of secular equilibrium of uranium with its daughters and that the uranium is uniformly distributed throughout an average soil mixture. The spectral distribution of the emitted gamma rays and the effect of air attenuation are discussed. Worked examples are given of typical situations encountered in uranium mines

  1. Self-reported sleep disturbances due to railway noise: exposure-response relationships for nighttime equivalent and maximum noise levels.

    Science.gov (United States)

    Aasvang, Gunn Marit; Moum, Torbjorn; Engdahl, Bo

    2008-07-01

    The objective of the present survey was to study self-reported sleep disturbances due to railway noise with respect to nighttime equivalent noise level (L(p,A,eq,night)) and maximum noise level (L(p,A,max)). A sample of 1349 people in and around Oslo in Norway exposed to railway noise was studied in a cross-sectional survey to obtain data on sleep disturbances, sleep problems due to noise, and personal characteristics including noise sensitivity. Individual noise exposure levels were determined outside of the bedroom facade, the most-exposed facade, and inside the respondents' bedrooms. The exposure-response relationships were analyzed by using logistic regression models, controlling for possible modifying factors including the number of noise events (train pass-by frequency). L(p,A,eq,night) and L(p,A,max) were significantly correlated, and the proportion of reported noise-induced sleep problems increased as both L(p,A,eq,night) and L(p,A,max) increased. Noise sensitivity, type of bedroom window, and pass-by frequency were significant factors affecting noise-induced sleep disturbances, in addition to the noise exposure level. Because about half of the study population did not use a bedroom at the most-exposed side of the house, the exposure-response curve obtained by using noise levels for the most-exposed facade underestimated noise-induced sleep disturbance for those who actually have their bedroom at the most-exposed facade.

  2. 75 FR 52947 - Maximum Per Diem Rates for the Continental United States (CONUS)

    Science.gov (United States)

    2010-08-30

    ... per diem rate setting process enhances the government's ability to obtain policy-compliant lodging where it is needed. In conjunction with the annual lodging study, GSA identified five new non-standard... diem localities and updates the standard CONUS rate. The CONUS per diem rates prescribed in Bulletin 11...

  3. Mercury Exposure and Heart Rate Variability: A Systematic Review

    Science.gov (United States)

    Gribble, Matthew O.; Cheng, Alan; Berger, Ronald D.; Rosman, Lori; Guallar, Eliseo

    2015-01-01

    Background Mercury affects the nervous system and has been implicated in altering heart rhythm and function. We sought to better define its role in modulating heart rate variability, a well-known marker of cardiac autonomic function. Design Systematic review. Methods We searched PubMed, Embase, TOXLINE and DART databases without language restriction. We report findings as a qualitative systematic review because heterogeneity in study design and assessment of exposures and outcomes across studies, as well as other methodological limitations of the literature, precluded a quantitative meta-analysis. Results We identified 12 studies of mercury exposure and heart rate variability in human populations (10 studies involving primarily environmental methylmercury exposure and two studies involving occupational exposure to inorganic mercury) conducted in Japan, the Faroe Islands, Canada, Korea, French Polynesia, Finland and Egypt. The association of prenatal mercury exposure with lower high-frequency band scores (thought to reflect parasympathetic activity) in several studies, in particular the inverse association of cord blood mercury levels with the coefficient of variation of the R-R intervals and with low frequency and high frequency bands at 14 years of age in the Faroe Islands birth cohort study, suggests that early mercury exposure could have a long-lasting effect on cardiac parasympathetic activity. Studies with later environmental exposures to mercury in children or in adults were heterogeneous and did not show consistent associations. Conclusions The evidence was too limited to draw firm causal inferences. Additional research is needed to elucidate the effects of mercury on cardiac autonomic function, particularly as early-life exposures might have lasting impacts on cardiac parasympathetic function. PMID:26231507

  4. Activity, exposure rate and spectrum prediction with Java programming

    International Nuclear Information System (INIS)

    Sahin, D.; Uenlue, K.

    2009-01-01

    In order to envision the radiation exposure during Neutron Activation Analysis (NAA) experiments, a software called Activity Predictor is developed using Java TM programming language. The Activity Predictor calculates activities, exposure rates and gamma spectra of activated samples for NAA experiments performed at Radiation Science and Engineering Center (RSEC), Penn State Breazeale Reactor (PSBR). The calculation procedure for predictions involves both analytical and Monte Carlo methods. The Activity Predictor software is validated with a series of activation experiments. It has been found that Activity Predictor software calculates the activities and exposure rates precisely. The software also predicts gamma spectrum for each measurement. The predicted spectra agreed partially with measured spectra. The error in net photo peak areas varied from 4.8 to 51.29%, which is considered to be due to simplistic modeling, statistical fluctuations and unknown contaminants in the samples. (author)

  5. Race, Exposure, and Initial Affective Ratings in Interpersonal Attraction.

    Science.gov (United States)

    Nikels, Kenneth W.; Hamm, Norman H.

    To test the mere exposure hypothesis, subjects were exposed to 20 slides of black and white stimulus persons. Based upon pre-experimental ratings, each slide had been initially assigned to one of four groups: high favorable black, high favorable white, low favorable black, and low favorable white. The experimental group, consisting of 25 white…

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

    Science.gov (United States)

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

  7. Effective dose rate coefficients for exposure to contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Veinot, K.G. [Easterly Scientific, Knoxville, TN (United States); Y-12 National Security Complex, Oak Ridge, TN (United States); Eckerman, K.F.; Easterly, C.E. [Easterly Scientific, Knoxville, TN (United States); Bellamy, M.B.; Hiller, M.M.; Dewji, S.A. [Oak Ridge National Laboratory, Center for Radiation Protection Knowledge, Oak Ridge, TN (United States); Hertel, N.E. [Oak Ridge National Laboratory, Center for Radiation Protection Knowledge, Oak Ridge, TN (United States); Georgia Institute of Technology, Atlanta, GA (United States); Manger, R. [University of California San Diego, Department of Radiation Medicine and Applied Sciences, La Jolla, CA (United States)

    2017-08-15

    The Oak Ridge National Laboratory Center for Radiation Protection Knowledge has undertaken calculations related to various environmental exposure scenarios. A previous paper reported the results for submersion in radioactive air and immersion in water using age-specific mathematical phantoms. This paper presents age-specific effective dose rate coefficients derived using stylized mathematical phantoms for exposure to contaminated soils. Dose rate coefficients for photon, electron, and positrons of discrete energies were calculated and folded with emissions of 1252 radionuclides addressed in ICRP Publication 107 to determine equivalent and effective dose rate coefficients. The MCNP6 radiation transport code was used for organ dose rate calculations for photons and the contribution of electrons to skin dose rate was derived using point-kernels. Bremsstrahlung and annihilation photons of positron emission were evaluated as discrete photons. The coefficients calculated in this work compare favorably to those reported in the US Federal Guidance Report 12 as well as by other authors who employed voxel phantoms for similar exposure scenarios. (orig.)

  8. Maximum rates of climate change are systematically underestimated in the geological record.

    Science.gov (United States)

    Kemp, David B; Eichenseer, Kilian; Kiessling, Wolfgang

    2015-11-10

    Recently observed rates of environmental change are typically much higher than those inferred for the geological past. At the same time, the magnitudes of ancient changes were often substantially greater than those established in recent history. The most pertinent disparity, however, between recent and geological rates is the timespan over which the rates are measured, which typically differ by several orders of magnitude. Here we show that rates of marked temperature changes inferred from proxy data in Earth history scale with measurement timespan as an approximate power law across nearly six orders of magnitude (10(2) to >10(7) years). This scaling reveals how climate signals measured in the geological record alias transient variability, even during the most pronounced climatic perturbations of the Phanerozoic. Our findings indicate that the true attainable pace of climate change on timescales of greatest societal relevance is underestimated in geological archives.

  9. Allometric equations for maximum filtration rate in blue mussels Mytilus edulis and importance of condition index

    DEFF Research Database (Denmark)

    Riisgård, Hans Ulrik; Larsen, Poul Scheel; Pleissner, Daniel

    2014-01-01

    rate (F, l h-1), W (g), and L (mm) as described by the equations: FW = aWb and FL = cLd, respectively. This is done by using available and new experimental laboratory data on M. edulis obtained by members of the same research team using different methods and controlled diets of cultivated algal cells...

  10. 76 FR 53134 - Maximum Per Diem Rates for the Continental United States (CONUS)

    Science.gov (United States)

    2011-08-25

    ... in the per diem rate setting process enhances the Government's ability to obtain policy-compliant...-standard area (NSA): Alexandria/Leesville/Natchitoches, Louisiana (Allen, Jefferson Davis, Natchitoches... the standard CONUS designation in FY 2011. Of those locations, the following areas will once again...

  11. Maximum inflation of the type 1 error rate when sample size and allocation rate are adapted in a pre-planned interim look.

    Science.gov (United States)

    Graf, Alexandra C; Bauer, Peter

    2011-06-30

    We calculate the maximum type 1 error rate of the pre-planned conventional fixed sample size test for comparing the means of independent normal distributions (with common known variance) which can be yielded when sample size and allocation rate to the treatment arms can be modified in an interim analysis. Thereby it is assumed that the experimenter fully exploits knowledge of the unblinded interim estimates of the treatment effects in order to maximize the conditional type 1 error rate. The 'worst-case' strategies require knowledge of the unknown common treatment effect under the null hypothesis. Although this is a rather hypothetical scenario it may be approached in practice when using a standard control treatment for which precise estimates are available from historical data. The maximum inflation of the type 1 error rate is substantially larger than derived by Proschan and Hunsberger (Biometrics 1995; 51:1315-1324) for design modifications applying balanced samples before and after the interim analysis. Corresponding upper limits for the maximum type 1 error rate are calculated for a number of situations arising from practical considerations (e.g. restricting the maximum sample size, not allowing sample size to decrease, allowing only increase in the sample size in the experimental treatment). The application is discussed for a motivating example. Copyright © 2011 John Wiley & Sons, Ltd.

  12. Outpacing the Anthropocene: New Constraints for the Rate of Carbon Release at the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Wright, J. D.; Schaller, M. F.

    2012-12-01

    The Paleocene/Eocene Thermal Maximum (PETM) Carbon Isotope Excursion (CIE) is linked to benthic foraminiferal extinction and excursion taxa in planktonic foraminifera and calcareous nannofossils. Previous studies have used integrated bio-magneto-stratigraphies, cycle counting, and extraterrestrial 3He accumulation rates to produce a range of estimates for the duration of the initial onset of the PETM CIE between 750 years to 30 kyr. Durations for the total release time (onset to initiation of recovery) range from 45 to 95 kyr. Uncertainty in the timing of the onset of the PETM CIE prevents the identification of a causal mechanism, and hence understanding the biological responses. Recent work on the Paleocene/Eocene Marlboro Clay has unveiled the presence of regular couplets (~2 cm) expressed in multiple cores and exposures throughout the Atlantic Coastal Plain. Specifically, the Millville and newly recovered Wilson Lake B cores contain 750 and 660 layers through the CIE, respectively. These couplets have corresponding oxygen stable isotope cycles, arguing for a climatic origin. Orbital and millennial periodicities are far too long to explain the ~750 layers identified in the Millville core. Seasonal insolation is the only regular climate cycle that can plausibly account for the observed δ18O amplitudes (~1‰, with some cycles up to 2‰) and layer counts. Seasonal freshwater input can also augment the cyclic oscillations in δ18O, but the majority of the variability is most plausibly ascribed to temperature. Wilson Lake B and Millville have total δ13C excursions of -5 and -4.5‰ respectively, as well as highly expanded sections of the PETM CIE. In the Millville core, high-resolution, bulk stable isotope records show a 3.5‰ δ13C decrease over 12 layers across the PETM CIE onset. Concomitant with this δ13C decrease is a sharp drop in CaCO3. Decreases in both proxies require a large, sudden release of isotopically light carbon. The couplet chronology indicates

  13. A novel approach to estimating potential maximum heavy metal exposure to ship recycling yard workers in Alang, India

    Energy Technology Data Exchange (ETDEWEB)

    Deshpande, Paritosh C.; Tilwankar, Atit K.; Asolekar, Shyam R., E-mail: asolekar@iitb.ac.in

    2012-11-01

    The 180 ship recycling yards located on Alang-Sosiya beach in the State of Gujarat on the west coast of India is the world's largest cluster engaged in dismantling. Yearly 350 ships have been dismantled (avg. 10,000 ton steel/ship) with the involvement of about 60,000 workers. Cutting and scrapping of plates or scraping of painted metal surfaces happens to be the commonly performed operation during ship breaking. The pollutants released from a typical plate-cutting operation can potentially either affect workers directly by contaminating the breathing zone (air pollution) or can potentially add pollution load into the intertidal zone and contaminate sediments when pollutants get emitted in the secondary working zone and gets subjected to tidal forces. There was a two-pronged purpose behind the mathematical modeling exercise performed in this study. First, to estimate the zone of influence up to which the effect of plume would extend. Second, to estimate the cumulative maximum concentration of heavy metals that can potentially occur in ambient atmosphere of a given yard. The cumulative maximum heavy metal concentration was predicted by the model to be between 113 {mu}g/Nm{sup 3} and 428 {mu}g/Nm{sup 3} (at 4 m/s and 1 m/s near-ground wind speeds, respectively). For example, centerline concentrations of lead (Pb) in the yard could be placed between 8 and 30 {mu}g/Nm{sup 3}. These estimates are much higher than the Indian National Ambient Air Quality Standards (NAAQS) for Pb (0.5 {mu}g/Nm{sup 3}). This research has already become the critical science and technology inputs for formulation of policies for eco-friendly dismantling of ships, formulation of ideal procedure and corresponding health, safety, and environment provisions. The insights obtained from this research are also being used in developing appropriate technologies for minimizing exposure to workers and minimizing possibilities of causing heavy metal pollution in the intertidal zone of ship recycling

  14. A novel approach to estimating potential maximum heavy metal exposure to ship recycling yard workers in Alang, India

    International Nuclear Information System (INIS)

    Deshpande, Paritosh C.; Tilwankar, Atit K.; Asolekar, Shyam R.

    2012-01-01

    The 180 ship recycling yards located on Alang–Sosiya beach in the State of Gujarat on the west coast of India is the world's largest cluster engaged in dismantling. Yearly 350 ships have been dismantled (avg. 10,000 ton steel/ship) with the involvement of about 60,000 workers. Cutting and scrapping of plates or scraping of painted metal surfaces happens to be the commonly performed operation during ship breaking. The pollutants released from a typical plate-cutting operation can potentially either affect workers directly by contaminating the breathing zone (air pollution) or can potentially add pollution load into the intertidal zone and contaminate sediments when pollutants get emitted in the secondary working zone and gets subjected to tidal forces. There was a two-pronged purpose behind the mathematical modeling exercise performed in this study. First, to estimate the zone of influence up to which the effect of plume would extend. Second, to estimate the cumulative maximum concentration of heavy metals that can potentially occur in ambient atmosphere of a given yard. The cumulative maximum heavy metal concentration was predicted by the model to be between 113 μg/Nm 3 and 428 μg/Nm 3 (at 4 m/s and 1 m/s near-ground wind speeds, respectively). For example, centerline concentrations of lead (Pb) in the yard could be placed between 8 and 30 μg/Nm 3 . These estimates are much higher than the Indian National Ambient Air Quality Standards (NAAQS) for Pb (0.5 μg/Nm 3 ). This research has already become the critical science and technology inputs for formulation of policies for eco-friendly dismantling of ships, formulation of ideal procedure and corresponding health, safety, and environment provisions. The insights obtained from this research are also being used in developing appropriate technologies for minimizing exposure to workers and minimizing possibilities of causing heavy metal pollution in the intertidal zone of ship recycling yards in India. -- Highlights

  15. Studying DDT Susceptibility at Discriminating Time Intervals Focusing on Maximum Limit of Exposure Time Survived by DDT Resistant Phlebotomus argentipes (Diptera: Psychodidae): an Investigative Report.

    Science.gov (United States)

    Rama, Aarti; Kesari, Shreekant; Das, Pradeep; Kumar, Vijay

    2017-07-24

    Extensive application of routine insecticide i.e., dichlorodiphenyltrichloroethane (DDT) to control Phlebotomus argentipes (Diptera: Psychodidae), the proven vector of visceral leishmaniasis in India, had evoked the problem of resistance/tolerance against DDT, eventually nullifying the DDT dependent strategies to control this vector. Because tolerating an hour-long exposure to DDT is not challenging enough for the resistant P. argentipes, estimating susceptibility by exposing sand flies to insecticide for just an hour becomes a trivial and futile task.Therefore, this bioassay study was carried out to investigate the maximum limit of exposure time to which DDT resistant P. argentipes can endure the effect of DDT for their survival. The mortality rate of laboratory-reared DDT resistant strain P. argentipes exposed to DDT was studied at discriminating time intervals of 60 min and it was concluded that highly resistant sand flies could withstand up to 420 min of exposure to this insecticide. Additionally, the lethal time for female P. argentipes was observed to be higher than for males suggesting that they are highly resistant to DDT's toxicity. Our results support the monitoring of tolerance limit with respect to time and hence points towards an urgent need to change the World Health Organization's protocol for susceptibility identification in resistant P. argentipes.

  16. Maximum Likelihood based comparison of the specific growth rates for P. aeruginosa and four mutator strains

    DEFF Research Database (Denmark)

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo; Mandsberg, Lotte Frigaard

    2008-01-01

    with an exponentially decaying function of the time between observations is suggested. A model with a full covariance structure containing OD-dependent variance and an autocorrelation structure is compared to a model with variance only and with no variance or correlation implemented. It is shown that the model...... are used for parameter estimation. The data is log-transformed such that a linear model can be applied. The transformation changes the variance structure, and hence an OD-dependent variance is implemented in the model. The autocorrelation in the data is demonstrated, and a correlation model...... that best describes data is a model taking into account the full covariance structure. An inference study is made in order to determine whether the growth rate of the five bacteria strains is the same. After applying a likelihood-ratio test to models with a full covariance structure, it is concluded...

  17. Modeling emission rates and exposures from outdoor cooking

    Science.gov (United States)

    Edwards, Rufus; Princevac, Marko; Weltman, Robert; Ghasemian, Masoud; Arora, Narendra K.; Bond, Tami

    2017-09-01

    Approximately 3 billion individuals rely on solid fuels for cooking globally. For a large portion of these - an estimated 533 million - cooking is outdoors, where emissions from cookstoves pose a health risk to both cooks and other household and village members. Models that estimate emissions rates from stoves in indoor environments that would meet WHO air quality guidelines (AQG), explicitly don't account for outdoor cooking. The objectives of this paper are to link health based exposure guidelines with emissions from outdoor cookstoves, using a Monte Carlo simulation of cooking times from Haryana India coupled with inverse Gaussian dispersion models. Mean emission rates for outdoor cooking that would result in incremental increases in personal exposure equivalent to the WHO AQG during a 24-h period were 126 ± 13 mg/min for cooking while squatting and 99 ± 10 mg/min while standing. Emission rates modeled for outdoor cooking are substantially higher than emission rates for indoor cooking to meet AQG, because the models estimate impact of emissions on personal exposure concentrations rather than microenvironment concentrations, and because the smoke disperses more readily outdoors compared to indoor environments. As a result, many more stoves including the best performing solid-fuel biomass stoves would meet AQG when cooking outdoors, but may also result in substantial localized neighborhood pollution depending on housing density. Inclusion of the neighborhood impact of pollution should be addressed more formally both in guidelines on emissions rates from stoves that would be protective of health, and also in wider health impact evaluation efforts and burden of disease estimates. Emissions guidelines should better represent the different contexts in which stoves are being used, especially because in these contexts the best performing solid fuel stoves have the potential to provide significant benefits.

  18. A rotation-symmetric, position-sensitive annular detector for maximum counting rates

    International Nuclear Information System (INIS)

    Igel, S.

    1993-12-01

    The Germanium Wall is a semiconductor detector system containing up to four annular position sensitive ΔE-detectors from high purity germanium (HPGe) planned to complement the BIG KARL spectrometer in COSY experiments. The first diode of the system, the Quirl-detector, has a two dimensional position sensitive structure defined by 200 Archimedes' spirals on each side with opposite orientation. In this way about 40000 pixels are defined. Since each spiral element detects almost the same number of events in an experiment the whole system can be optimized for maximal counting rates. This paper describes a test setup for a first prototype of the Quirl-detector and the results of test measurements with an α-source. The detector current and the electrical separation of the spiral elements were measured. The splitting of signals due to the spread of charge carriers produced by an incident ionizing particle on several adjacent elements was investigated in detail and found to be twice as high as expected from calculations. Its influence on energy and position resolution is discussed. Electronic crosstalk via signal wires and the influence of noise from the magnetic spectrometer has been tested under experimental conditions. Additionally, vacuum feedthroughs based on printed Kapton foils pressed between Viton seals were fabricated and tested successfully concerning their vacuum and thermal properties. (orig.)

  19. Late development of homoeothermy in mink (Mustela vison) kits - a strategy for maximum survival rate

    DEFF Research Database (Denmark)

    Tauson, A-H; Chwalibog, André; Tygesen, M P

    2006-01-01

    and after the experiments and evaporative water losses (EWL) were calculated. When exposed to L temperature, single kits responded with a very low HE until 29 days of age, and groups of kits until 14 days of age. It was not until they reached an age of approximately 6 weeks that single kits showed a clear...... thermoregulatory response to the L temperature by increased HE, whereas groups of kits showed increased HE from 29th day onwards. When kept at H temperature, HE was low initially, but all kits showed elevated HE at 8 days of age, and the metabolic rate was similar for single kits and kits huddling in groups....... Evaporative water losses was higher among single than among groups of kits and slightly lower but more variable for animals at L than at H temperature. It was concluded that mink kits develop functional homoeothermy at an age of close to 6 weeks and that the failure of very young kits to thermoregulate...

  20. Gamma exposure rates in the Steel Creek and Little Hell landing areas

    International Nuclear Information System (INIS)

    Marter, W.L.

    1975-01-01

    Aeroradiographic and ground transect γ surveys in the summer of 1974 were conducted to determine the degree of offsite radioactive contamination in an area immediately below the Savannah River plant boundary. Since it is recognized that mechanisms in the biosphere tend to cause nonhomogenous distribution and redistribution of radionuclides released to the environment, a plan was developed to continually evaluate the radioactivity of the offsite area. As part of this plan, a 1300-foot-long section of offsite swamp (42.9 acres) adjacent to the SRP boundary was surveyed in the latter half of October 1974 on a 10-foot grid pattern. The results of this survey show that 6.6 of the 42.9 acres surveyed in detail has γ exposure rates exceeding 57 μR/hr (approximately 500 mR/yr). The maximum exposure rate found at a single grid point was 120 μR/hr. Approximately 5.8 Ci of 137 Cs was deposited in the 42.9-acre 10-foot grid survey area. It was calculated a hypothetical person residing continuously in the location of highest exposure rate when the swamp is not flooded (77 percent of the time each year) could receive an annual dose of about 809 mR. Previous surveys of this area indicated a maximum external annual dose of 357 mR under the same residency conditions. Even with the higher exposure rates detected in the 10-foot grid survey, the more probable incremental radiation dose (above background) to hunters and fishermen who spend a few hours to a few hundred hours in this section of swamp would range from less than 1 mR to a few tens of mR per year

  1. Is there a maximum star formation rate in high-redshift galaxies? , , ,

    International Nuclear Information System (INIS)

    Barger, A. J.; Cowie, L. L.; Chen, C.-C.; Casey, C. M.; Lee, N.; Sanders, D. B.; Williams, J. P.; Owen, F. N.; Wang, W.-H.

    2014-01-01

    We use the James Clerk Maxwell Telescope's SCUBA-2 camera to image a 400 arcmin 2 area surrounding the GOODS-N field. The 850 μm rms noise ranges from a value of 0.49 mJy in the central region to 3.5 mJy at the outside edge. From these data, we construct an 850 μm source catalog to 2 mJy containing 49 sources detected above the 4σ level. We use an ultradeep (11.5 μJy at 5σ) 1.4 GHz image obtained with the Karl G. Jansky Very Large Array together with observations made with the Submillimeter Array to identify counterparts to the submillimeter galaxies. For most cases of multiple radio counterparts, we can identify the correct counterpart from new and existing Submillimeter Array data. We have spectroscopic redshifts for 62% of the radio sources in the 9' radius highest sensitivity region (556/894) and 67% of the radio sources in the GOODS-N region (367/543). We supplement these with a modest number of additional photometric redshifts in the GOODS-N region (30). We measure millimetric redshifts from the radio to submillimeter flux ratios for the unidentified submillimeter sample, assuming an Arp 220 spectral energy distribution. We find a radio-flux-dependent K – z relation for the radio sources, which we use to estimate redshifts for the remaining radio sources. We determine the star formation rates (SFRs) of the submillimeter sources based on their radio powers and their submillimeter fluxes and find that they agree well. The radio data are deep enough to detect star-forming galaxies with SFRs >2000 M ☉ yr –1 to z ∼ 6. We find galaxies with SFRs up to ∼6000 M ☉ yr –1 over the redshift range z = 1.5-6, but we see evidence for a turn-down in the SFR distribution function above 2000 M ☉ yr –1 .

  2. Is There a Maximum Star Formation Rate in High-redshift Galaxies?

    Science.gov (United States)

    Barger, A. J.; Cowie, L. L.; Chen, C.-C.; Owen, F. N.; Wang, W.-H.; Casey, C. M.; Lee, N.; Sanders, D. B.; Williams, J. P.

    2014-03-01

    We use the James Clerk Maxwell Telescope's SCUBA-2 camera to image a 400 arcmin2 area surrounding the GOODS-N field. The 850 μm rms noise ranges from a value of 0.49 mJy in the central region to 3.5 mJy at the outside edge. From these data, we construct an 850 μm source catalog to 2 mJy containing 49 sources detected above the 4σ level. We use an ultradeep (11.5 μJy at 5σ) 1.4 GHz image obtained with the Karl G. Jansky Very Large Array together with observations made with the Submillimeter Array to identify counterparts to the submillimeter galaxies. For most cases of multiple radio counterparts, we can identify the correct counterpart from new and existing Submillimeter Array data. We have spectroscopic redshifts for 62% of the radio sources in the 9' radius highest sensitivity region (556/894) and 67% of the radio sources in the GOODS-N region (367/543). We supplement these with a modest number of additional photometric redshifts in the GOODS-N region (30). We measure millimetric redshifts from the radio to submillimeter flux ratios for the unidentified submillimeter sample, assuming an Arp 220 spectral energy distribution. We find a radio-flux-dependent K - z relation for the radio sources, which we use to estimate redshifts for the remaining radio sources. We determine the star formation rates (SFRs) of the submillimeter sources based on their radio powers and their submillimeter fluxes and find that they agree well. The radio data are deep enough to detect star-forming galaxies with SFRs >2000 M ⊙ yr-1 to z ~ 6. We find galaxies with SFRs up to ~6000 M ⊙ yr-1 over the redshift range z = 1.5-6, but we see evidence for a turn-down in the SFR distribution function above 2000 M ⊙ yr-1. The James Clerk Maxwell Telescope is operated by the Joint Astronomy Centre on behalf of the Science and Technology Facilities Council of the United Kingdom, the National Research Council of Canada, and (until 2013 March 31) the Netherlands Organisation for Scientific

  3. ReplacementMatrix: a web server for maximum-likelihood estimation of amino acid replacement rate matrices.

    Science.gov (United States)

    Dang, Cuong Cao; Lefort, Vincent; Le, Vinh Sy; Le, Quang Si; Gascuel, Olivier

    2011-10-01

    Amino acid replacement rate matrices are an essential basis of protein studies (e.g. in phylogenetics and alignment). A number of general purpose matrices have been proposed (e.g. JTT, WAG, LG) since the seminal work of Margaret Dayhoff and co-workers. However, it has been shown that matrices specific to certain protein groups (e.g. mitochondrial) or life domains (e.g. viruses) differ significantly from general average matrices, and thus perform better when applied to the data to which they are dedicated. This Web server implements the maximum-likelihood estimation procedure that was used to estimate LG, and provides a number of tools and facilities. Users upload a set of multiple protein alignments from their domain of interest and receive the resulting matrix by email, along with statistics and comparisons with other matrices. A non-parametric bootstrap is performed optionally to assess the variability of replacement rate estimates. Maximum-likelihood trees, inferred using the estimated rate matrix, are also computed optionally for each input alignment. Finely tuned procedures and up-to-date ML software (PhyML 3.0, XRATE) are combined to perform all these heavy calculations on our clusters. http://www.atgc-montpellier.fr/ReplacementMatrix/ olivier.gascuel@lirmm.fr Supplementary data are available at http://www.atgc-montpellier.fr/ReplacementMatrix/

  4. Exposure rates from concrete covered cylindrical units containing radioactive waste

    International Nuclear Information System (INIS)

    Hedemann Jensen, P.

    1983-03-01

    Exposure rates from cylindrical waste units containing the nuclides 60 Co, 134 Cs and 137 Cs homogeneously mixed in a solidification product have been calculated. Analyses have been made for single drums and for two disposal geometries, one with the units placed below ground near the surface in a circular geometry, and one with the units placed on the ground in a pile behind a concrete wall. Due to self-shielding of the units, the exposure rate from the two geometries will be a factor of only 10 - 20 higher than from a single unit, even without soil or wall shielding. With one meter of soil above the circular pile below ground, a reduction factor of 5.10 3 to 5.10 4 can be achieved, depending on the nuclide considered. Placing a one-meter concrete wall in front of the drum pile on the ground gives rise to a reduction factor in the range of 5.10 5 to 2.10 7 . (author)

  5. Maximum permissible continuous release rates of phosphorus-32 and sulphur-35 to atmosphere in a milk producing area

    Energy Technology Data Exchange (ETDEWEB)

    Bryant, P M

    1963-01-01

    A method is given for calculating, for design purposes, the maximum permissible continuous release rates of phosphorus-32 and sulphur-35 to atmosphere with respect to milk contamination. In the absence of authoritative advice from the Medical Research Council, provisional working levels for the concentration of phosphorus-32 and sulphur-35 in milk are derived, and details are given of the agricultural assumptions involved in the calculation of the relationship between the amount of the nuclide deposited on grassland and that to be found in milk. The agricultural and meteorological conditions assumed are applicable as an annual average to England and Wales. The results (in mc/day) for phosphorus-32 and sulphur-35 for a number of stack heights and distances are shown graphically; typical values, quoted in a table, include 20 mc/day of phosphorus-32 and 30 mc/day of sulfur-35 as the maximum permissible continuous release rates with respect to ground level releases at a distance of 200 metres from pastureland.

  6. Maximum type I error rate inflation from sample size reassessment when investigators are blind to treatment labels.

    Science.gov (United States)

    Żebrowska, Magdalena; Posch, Martin; Magirr, Dominic

    2016-05-30

    Consider a parallel group trial for the comparison of an experimental treatment to a control, where the second-stage sample size may depend on the blinded primary endpoint data as well as on additional blinded data from a secondary endpoint. For the setting of normally distributed endpoints, we demonstrate that this may lead to an inflation of the type I error rate if the null hypothesis holds for the primary but not the secondary endpoint. We derive upper bounds for the inflation of the type I error rate, both for trials that employ random allocation and for those that use block randomization. We illustrate the worst-case sample size reassessment rule in a case study. For both randomization strategies, the maximum type I error rate increases with the effect size in the secondary endpoint and the correlation between endpoints. The maximum inflation increases with smaller block sizes if information on the block size is used in the reassessment rule. Based on our findings, we do not question the well-established use of blinded sample size reassessment methods with nuisance parameter estimates computed from the blinded interim data of the primary endpoint. However, we demonstrate that the type I error rate control of these methods relies on the application of specific, binding, pre-planned and fully algorithmic sample size reassessment rules and does not extend to general or unplanned sample size adjustments based on blinded data. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

  7. Exposure-rate calibration using large-area calibration pads

    International Nuclear Information System (INIS)

    Novak, E.F.

    1988-09-01

    The US Department of Energy (DOE) Office of Remedial Action and Waste Technology established the Technical Measurements Center (TMC) at the DOE Grand Junction Projects Office (GJPO) in Grand Junction, Colorado, to standardize, calibrate, and compare measurements made in support of DOE remedial action programs. A set of large-area, radioelement-enriched concrete pads was constructed by the DOE in 1978 at the Walker Field Airport in Grand Junction for use as calibration standards for airborne gamma-ray spectrometer systems. The use of these pads was investigated by the TMC as potential calibration standards for portable scintillometers employed in measuring gamma-ray exposure rates at Uranium Mill Tailings Remedial Action (UMTRA) project sites. Data acquired on the pads using a pressurized ionization chamber (PIC) and three scintillometers are presented as an illustration of an instrumental calibration. Conclusions and recommended calibration procedures are discussed, based on the results of these data

  8. Releasable activity and maximum permissible leakage rate within a transport cask of Tehran Research Reactor fuel samples

    Directory of Open Access Journals (Sweden)

    Rezaeian Mahdi

    2015-01-01

    Full Text Available Containment of a transport cask during both normal and accident conditions is important to the health and safety of the public and of the operators. Based on IAEA regulations, releasable activity and maximum permissible volumetric leakage rate within the cask containing fuel samples of Tehran Research Reactor enclosed in an irradiated capsule are calculated. The contributions to the total activity from the four sources of gas, volatile, fines, and corrosion products are treated separately. These calculations are necessary to identify an appropriate leak test that must be performed on the cask and the results can be utilized as the source term for dose evaluation in the safety assessment of the cask.

  9. Effects of adipose tissue distribution on maximum lipid oxidation rate during exercise in normal-weight women.

    Science.gov (United States)

    Isacco, L; Thivel, D; Duclos, M; Aucouturier, J; Boisseau, N

    2014-06-01

    Fat mass localization affects lipid metabolism differently at rest and during exercise in overweight and normal-weight subjects. The aim of this study was to investigate the impact of a low vs high ratio of abdominal to lower-body fat mass (index of adipose tissue distribution) on the exercise intensity (Lipox(max)) that elicits the maximum lipid oxidation rate in normal-weight women. Twenty-one normal-weight women (22.0 ± 0.6 years, 22.3 ± 0.1 kg.m(-2)) were separated into two groups of either a low or high abdominal to lower-body fat mass ratio [L-A/LB (n = 11) or H-A/LB (n = 10), respectively]. Lipox(max) and maximum lipid oxidation rate (MLOR) were determined during a submaximum incremental exercise test. Abdominal and lower-body fat mass were determined from DXA scans. The two groups did not differ in aerobic fitness, total fat mass, or total and localized fat-free mass. Lipox(max) and MLOR were significantly lower in H-A/LB vs L-A/LB women (43 ± 3% VO(2max) vs 54 ± 4% VO(2max), and 4.8 ± 0.6 mg min(-1)kg FFM(-1)vs 8.4 ± 0.9 mg min(-1)kg FFM(-1), respectively; P normal-weight women, a predominantly abdominal fat mass distribution compared with a predominantly peripheral fat mass distribution is associated with a lower capacity to maximize lipid oxidation during exercise, as evidenced by their lower Lipox(max) and MLOR. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  10. TU-FG-209-03: Exploring the Maximum Count Rate Capabilities of Photon Counting Arrays Based On Polycrystalline Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Liang, A K; Koniczek, M; Antonuk, L E; El-Mohri, Y; Zhao, Q [University of Michigan, Ann Arbor, MI (United States)

    2016-06-15

    Purpose: Photon counting arrays (PCAs) offer several advantages over conventional, fluence-integrating x-ray imagers, such as improved contrast by means of energy windowing. For that reason, we are exploring the feasibility and performance of PCA pixel circuitry based on polycrystalline silicon. This material, unlike the crystalline silicon commonly used in photon counting detectors, lends itself toward the economic manufacture of radiation tolerant, monolithic large area (e.g., ∼43×43 cm2) devices. In this presentation, exploration of maximum count rate, a critical performance parameter for such devices, is reported. Methods: Count rate performance for a variety of pixel circuit designs was explored through detailed circuit simulations over a wide range of parameters (including pixel pitch and operating conditions) with the additional goal of preserving good energy resolution. The count rate simulations assume input events corresponding to a 72 kVp x-ray spectrum with 20 mm Al filtration interacting with a CZT detector at various input flux rates. Output count rates are determined at various photon energy threshold levels, and the percentage of counts lost (e.g., due to deadtime or pile-up) is calculated from the ratio of output to input counts. The energy resolution simulations involve thermal and flicker noise originating from each circuit element in a design. Results: Circuit designs compatible with pixel pitches ranging from 250 to 1000 µm that allow count rates over a megacount per second per pixel appear feasible. Such rates are expected to be suitable for radiographic and fluoroscopic imaging. Results for the analog front-end circuitry of the pixels show that acceptable energy resolution can also be achieved. Conclusion: PCAs created using polycrystalline silicon have the potential to offer monolithic large-area detectors with count rate performance comparable to those of crystalline silicon detectors. Further improvement through detailed circuit

  11. Maximum standard metabolic rate corresponds with the salinity of maximum growth in hatchlings of the estuarine northern diamondback terrapin (Malaclemys terrapin terrapin): Implications for habitat conservation

    Science.gov (United States)

    Rowe, Christopher L.

    2018-01-01

    I evaluated standard metabolic rates (SMR) of hatchling northern diamondback terrapins (Malaclemys terrapin terrapin) across a range of salinities (salinity = 1.5, 4, 8, 12, and 16 psu) that they may encounter in brackish habitats such as those in the Maryland portion of the Chesapeake Bay, U.S.A. Consumption of O2 and production of CO2 by resting, unfed animals served as estimates of SMR. A peak in SMR occurred at 8 psu which corresponds closely with the salinity at which hatchling growth was previously shown to be maximized (salinity ∼ 9 psu). It appears that SMR is influenced by growth, perhaps reflecting investments in catabolic pathways that fuel anabolism. This ecophysiological information can inform environmental conservation and management activities by identifying portions of the estuary that are bioenergetically optimal for growth of hatchling terrapins. I suggest that conservation and restoration efforts to protect terrapin populations in oligo-to mesohaline habitats should prioritize protection or creation of habitats in regions where average salinity is near 8 psu and energetic investments in growth appear to be maximized.

  12. To the elementary theory of critical (maximum) flow rate of two-phase mixture in channels with various sections

    International Nuclear Information System (INIS)

    Nigmatulin, B.I.; Soplenkov, K.I.

    1978-01-01

    On the basis of the concepts of two-phase dispersive flow with various structures (bubble, vapour-drop etc) in the framework of the two-speed and two-temperature one-dimension stationary model of the current with provision for phase transitions the conditions, under which a critical (maximum) flow rate of two-phase mixture is achieved during its outflowing from a channel with the pre-set geometry, have been determined. It is shown, that for the choosen set of two-phase flow equations with the known parameters of deceleration and structure one of the critical conditions is satisfied: either solution of the set of equations corresponding a critical flow rate is a special one, i.e. passes through a special point locating between minimum and outlet channel sections where the carrying phase velocity approaches the value of decelerated sound speed in the mixture or the determinator of the initial set of equations equals zero for the outlet channel sections, i.e. gradients of the main flow parameters tend to +-infinity in this section, and carrying phase velocity also approaches the value of the decelerated sound velocity in the mixture

  13. Estimation of the players maximum heart rate in real game situations in team sports: a practical propose

    Directory of Open Access Journals (Sweden)

    Jorge Cuadrado Reyes

    2011-05-01

    Full Text Available Abstract   This  research developed a logarithms  for calculating the maximum heart rate (max. HR for players in team sports in  game situations. The sample was made of  thirteen players (aged 24 ± 3   to a  Division Two Handball team. HR was initially measured by Course Navette test.  Later, twenty one training sessions were conducted  in which HR and Rate of Perceived Exertion (RPE, were  continuously monitored, in each task. A lineal regression analysis was done  to help find a max. HR prediction equation from the max. HR of the three highest intensity sessions. Results from  this equation correlate significantly with data obtained in the Course Navette test and with those obtained by other indirect methods. The conclusion of this research is that this equation provides a very useful and easy way to measure the max. HR in real game situations, avoiding non-specific analytical tests and, therefore laboratory testing..   Key words: workout control, functional evaluation, prediction equation.

  14. Test-Retest Reliability of Rating of Perceived Exertion and Agreement With 1-Repetition Maximum in Adults.

    Science.gov (United States)

    Bove, Allyn M; Lynch, Andrew D; DePaul, Samantha M; Terhorst, Lauren; Irrgang, James J; Fitzgerald, G Kelley

    2016-09-01

    Study Design Clinical measurement. Background It has been suggested that rating of perceived exertion (RPE) may be a useful alternative to 1-repetition maximum (1RM) to determine proper resistance exercise dosage. However, the test-retest reliability of RPE for resistance exercise has not been determined. Additionally, prior research regarding the relationship between 1RM and RPE is conflicting. Objectives The purpose of this study was to (1) determine test-retest reliability of RPE related to resistance exercise and (2) assess agreement between percentages of 1RM and RPE during quadriceps resistance exercise. Methods A sample of participants with and without knee pathology completed a series of knee extension exercises and rated the perceived difficulty of each exercise on a 0-to-10 RPE scale, then repeated the procedure 1 to 2 weeks later for test-retest reliability. To determine agreement between RPE and 1RM, participants completed knee extension exercises at various percentages of their 1RM (10% to 130% of predicted 1RM) and rated the perceived difficulty of each exercise on a 0-to-10 RPE scale. Percent agreement was calculated between the 1RM and RPE at each resistance interval. Results The intraclass correlation coefficient indicated excellent test-retest reliability of RPE for quadriceps resistance exercises (intraclass correlation coefficient = 0.895; 95% confidence interval: 0.866, 0.918). Overall percent agreement between RPE and 1RM was 60%, but agreement was poor within the ranges that would typically be used for training (50% 1RM for muscle endurance, 70% 1RM and greater for strength). Conclusion Test-retest reliability of perceived exertion during quadriceps resistance exercise was excellent. However, agreement between the RPE and 1RM was poor, especially in common training zones for knee extensor strengthening. J Orthop Sports Phys Ther 2016;46(9):768-774. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6498.

  15. Theoretical determination of spectrum-exposure rate conversion operator of HPGe detector and its application to the measurement of environmental gamma-ray exposure rate

    International Nuclear Information System (INIS)

    Park, Ch.M.; Choi, B.I.; Kwak, S.S.; Ji, P.K.; Kim, T.W.; Park, Y.W.; Yoon, B.K.

    1993-01-01

    A conversion operator between spectrum and exposure rate, using a portable HPGe detector for environmental radiation monitoring, was determined theoretically under the assumption of uniform distribution of radiation source on the ground surface. The measurement results were compared with those of a pressurized ionization chamber. The results obtained with the HPGe detector were slightly lower. The method can be easily applied to any gamma ray detector to obtain a spectrum - exposure-rate conversion factor for computing the exposure rate of environmental gamma radiation. (N.T.) 15 refs.; 6 figs.; 3 tabs

  16. Influence of the most important data on the calculation of the maximum radiation exposure in the vicinity of nuclear facilities

    International Nuclear Information System (INIS)

    Schmidtlein, P.; Bonka, H.; Hesel, D.; Horn, H.G.

    1980-01-01

    Analysis of radiation exposure due to radionuclides released from nuclear facilities is discussed in relation to the demands of the Radiation Protection Oridinance in the Federal Republic of Germany. The results of the following estimations are presented as examples:- 1) The contribution of relevant radionuclides to the radiation exposure of an adult via the air pathway. 2) Contribution of relevant radionuclides to the radiation exposure of an adult via the water pathway. 3) Doses to lung and bone due to inhalation of 90 Sr aerosols with various particle diameters. 4) The influence of the plant-, milk- and meat transfer factors on the ingestion dose. 5) Accumulation factors in fish, in relation to consumption. 6) Variation of ground concentration due to loss of radionuclides via washing out into lower soil layers and harvest. (U.K.)

  17. Estimating Exchange Rate Exposure over Various Return Horizons: Focusing on Major Countries in East Asia

    Directory of Open Access Journals (Sweden)

    Jeong Wook Lee

    2016-12-01

    Full Text Available In this paper, we estimate the exchange rate exposure, indicating the effect of exchange rate movements on firm values, for a sample of 1,400 firms in seven East Asian countries. The exposure estimates based on various exchange rate variables, return horizons and a control variable are compared. A key result from our analysis is that the long term effect of exchange rate movements on firm values is greater than the short term effect. And we find very similar results from using other exchange rate variables such as the U.S. dollar exchange rate, etc. Second, we add exchange rate volatility as a control variable and find that the extent of exposure is not much changed. Third, we examine the changes in exposure to exchange rate volatility with an increase in return horizon. Consequently the ratio of firms with significant exposures increases with the return horizons. Interestingly, the increase of exposure with the return horizons is faster for exposure to volatility than for exposure to exchange rate itself. Taken as a whole, our findings suggest that the so-called "exposure puzzle" may be a matter of the methodology used to measure exposure.

  18. Relationship between visual prostate score (VPSS and maximum flow rate (Qmax in men with urinary tract symptoms

    Directory of Open Access Journals (Sweden)

    Mazhar A. Memon

    2016-04-01

    Full Text Available ABSTRACT Objective: To evaluate correlation between visual prostate score (VPSS and maximum flow rate (Qmax in men with lower urinary tract symptoms. Material and Methods: This is a cross sectional study conducted at a university Hospital. Sixty-seven adult male patients>50 years of age were enrolled in the study after signing an informed consent. Qmax and voided volume recorded at uroflowmetry graph and at the same time VPSS were assessed. The education level was assessed in various defined groups. Pearson correlation coefficient was computed for VPSS and Qmax. Results: Mean age was 66.1±10.1 years (median 68. The mean voided volume on uroflowmetry was 268±160mL (median 208 and the mean Qmax was 9.6±4.96mLs/sec (median 9.0. The mean VPSS score was 11.4±2.72 (11.0. In the univariate linear regression analysis there was strong negative (Pearson's correlation between VPSS and Qmax (r=848, p<0.001. In the multiple linear regression analyses there was a significant correlation between VPSS and Qmax (β-http://www.blogapaixonadosporviagens.com.br/p/caribe.html after adjusting the effect of age, voided volume (V.V and level of education. Multiple linear regression analysis done for independent variables and results showed that there was no significant correlation between the VPSS and independent factors including age (p=0.27, LOE (p=0.941 and V.V (p=0.082. Conclusion: There is a significant negative correlation between VPSS and Qmax. The VPSS can be used in lieu of IPSS score. Men even with limited educational background can complete VPSS without assistance.

  19. Evaluation of selected parameters on exposure rates in Westinghouse designed nuclear power plants

    International Nuclear Information System (INIS)

    Bergmann, C.A.

    1989-01-01

    During the past ten years, Westinghouse under EPRI contract and independently, has performed research and evaluation of plant data to define the trends of ex-core component exposure rates and the effects of various parameters on the exposure rates. The effects of the parameters were evaluated using comparative analyses or empirical techniques. This paper updates the information presented at the Fourth Bournemouth Conference and the conclusions obtained from the effects of selected parameters namely, coolant chemistry, physical changes, use of enriched boric acid, and cobalt input on plant exposure rates. The trends of exposure rates and relationship to doses is also presented. (author)

  20. MEMS pressure sensor with maximum performances by using novel back-side direct-exposure concept featuring through glass vias

    Science.gov (United States)

    Mukhopadhyay, B.; Fritz, M.; Mackowiak, P.; Vu, T. C.; Ehrmann, O.; Lang, K.-D.; Ngo, H.-D.

    2013-05-01

    Design, simulation, fabrication, and characterization of novel MEMS pressure sensors with new back-side-direct-exposure packaging concept are presented. The sensor design is optimized for harsh environments e.g. space, military, offshore and medical applications. Unbreakable connection between the active side of the Si-sensor and the protecting glass capping was realized by anodic bonding using a thin layer of metal. To avoid signal corruption of the measured pressure caused by an encapsulation system, the media has direct contact to the backside of the Si membrane and can deflect it.

  1. Energy and rate dependence of diagnostic x-ray exposure meters

    International Nuclear Information System (INIS)

    Wagner, L.K.; Cerra, F.; Conway, B.; Fewell, T.R.; Ohlhaber, T.R.

    1988-01-01

    Variations in x-ray exposure measurements among a variety of contemporary diagnostic exposure meters are investigated. Variations may result from systematic errors due to calibration, beam-quality dependence and exposure-rate dependence. It is concluded that the majority of general purpose diagnostic meters will agree to within 10% of each other if exposure rates are below 1.3 mC kg-1S-1 of air (5 R s-1) and beam qualities are typical for general purpose radiology, excluding mammography. For exposure rates comparable to those in barium enema radiography the variations can range up to 25% or more. Variations up to 40% were observed among general purpose exposure meters at mammographic beam qualities. In the mammographic range, mammographic (thin window) exposure meters varied by no more than 2%

  2. Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario

    International Nuclear Information System (INIS)

    Chen, Xi Lin; De Santis, Valerio; Umenei, Aghuinyue Esai

    2014-01-01

    In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates. (paper)

  3. Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario.

    Science.gov (United States)

    Chen, Xi Lin; De Santis, Valerio; Umenei, Aghuinyue Esai

    2014-07-07

    In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates.

  4. Exchange Rate Exposures and Strategies of Industrial Companies: An Empirical Study

    DEFF Research Database (Denmark)

    Aabo, Tom

    2001-01-01

    This article investigates empirically the potential and actual exchange rate exposure strategies of industrial companies in relation to identifying and quantifying the neutral financial positions in an optimal hedging strategy.......This article investigates empirically the potential and actual exchange rate exposure strategies of industrial companies in relation to identifying and quantifying the neutral financial positions in an optimal hedging strategy....

  5. Study of tourists exposure rate in Mahallat hot Spring Region

    International Nuclear Information System (INIS)

    Tavakoli, H. M.B.; Fallah, M.G.; Ghiasinejad, M.

    2006-01-01

    Introduction: High level radiation areas have been recognized on various parts of the earth. Some of these areas include: Brasilia, India, and Iran. Mahallat hot spring region in the central part of Iran is also one of these areas. Study of exposure in these areas could be helpful in investigating the effects of ionizing radiation. Materials and Methods: In addition to several seasonal springs, Mahallat hot spring region contains five permanent springs named: Soleimani, Shafa, Dombe, Romatism and Sauda. Internal exposure (due to inhalation of radon gas and drinking water) and external exposure (due to cosmic rays and radioactive elements in the ground) to the tourists was studied. Used materials and apparatus include: RSS -112 ionizing chamber for environmental gamma rays exposure measurement, highly pure germanium detector for measuring radioactive elements in the ground, liquid scintillation counter for measuring 222 Rn gas concentration in water samples, Bubbler chamber and Locus cells for Rn concentration measurements (Emanation method) and Alfa guard detector for 226 Ra concentration measurements. Conclusions and Discussion: A total of 270 visitors are included in this study. Considering residual durations of the studied group in open and closed environment of bathrooms, hotel and inn rooms, obtained annual external effective dose is 75.4±8.7μSv and 138.3±11.8μSv for natives and travelers respectively. EEC coefficients has been used for calculating annual internal effective dose due to radon gas inhalation. Annual internal effective dose, in this path, is 0.9 and 2.1 mSv in open and closed environment for native and visitors respectively. Annual internal effective dose due to drinking water, is 0.43 and 0.09μSv for natives people and travelers, respectively. Measurements show that more than 90% of the received dose in the studied groups is due to radon gas inhalation. External and internal dose summation is 0.98 mSv for natives and 2.2 mSv for for

  6. Study of tourists exposure rate in Mahallat hot Spring Region

    Energy Technology Data Exchange (ETDEWEB)

    Tavakoli, H. M.B. [Isfahan Univ. of Medical Sciences, Isfahan (Iran, Islamic Republic of); Fallah, M.G. [Isfahan University of Medical Sciences (Iran, Islamic Republic of); Ghiasinejad, M. [Iran Atomic Energy Organization, Tehran (Iran, Islamic Republic of)

    2006-07-01

    Introduction: High level radiation areas have been recognized on various parts of the earth. Some of these areas include: Brasilia, India, and Iran. Mahallat hot spring region in the central part of Iran is also one of these areas. Study of exposure in these areas could be helpful in investigating the effects of ionizing radiation. Materials and Methods: In addition to several seasonal springs, Mahallat hot spring region contains five permanent springs named: Soleimani, Shafa, Dombe, Romatism and Sauda. Internal exposure (due to inhalation of radon gas and drinking water) and external exposure (due to cosmic rays and radioactive elements in the ground) to the tourists was studied. Used materials and apparatus include: RSS -112 ionizing chamber for environmental gamma rays exposure measurement, highly pure germanium detector for measuring radioactive elements in the ground, liquid scintillation counter for measuring {sup 222}Rn gas concentration in water samples, Bubbler chamber and Locus cells for Rn concentration measurements (Emanation method) and Alfa guard detector for {sup 226}Ra concentration measurements. Conclusions and Discussion: A total of 270 visitors are included in this study. Considering residual durations of the studied group in open and closed environment of bathrooms, hotel and inn rooms, obtained annual external effective dose is 75.4{+-}8.7{mu}Sv and 138.3{+-}11.8{mu}Sv for natives and travelers respectively. EEC coefficients has been used for calculating annual internal effective dose due to radon gas inhalation. Annual internal effective dose, in this path, is 0.9 and 2.1 mSv in open and closed environment for native and visitors respectively. Annual internal effective dose due to drinking water, is 0.43 and 0.09{mu}Sv for natives people and travelers, respectively. Measurements show that more than 90% of the received dose in the studied groups is due to radon gas inhalation. External and internal dose summation is 0.98 mSv for natives and 2

  7. Asymmetric Exchange Rate Exposures: A Search for the Effect of Real Options

    DEFF Research Database (Denmark)

    Aabo, Tom

    2001-01-01

    Real options like the ability to reallocate production resources can lead to an asymmetric exchange rate exposure. Using a stock market approach in which the exchange rate exposure is derived from the information content in the stock prices this study examines the extra-market exchange rate...... exposures of a group of blue chip, industrial companies listed on the Copenhagen Stock Exchange. In these companies the existence of real options is an integrated part of the exchange rate exposure management process. The result of the stock market approach is mixed. Statistically significant asymmetric...... exchange rate exposures are identified successfully but the asymmetries can only to a limited extent be explained by the existence of real options. Financial options and pricing to market are competing explanations. Omitted variable bias further blurs the picture. These problems and the concept of path...

  8. The effect of exposure rate of the growth of soybean seedlings grown from gamma irradiated seeds

    International Nuclear Information System (INIS)

    Mohd Yusof, A.; Grunewald, R.

    1981-01-01

    The effect of the gamma ( 137 Cs) total exposure rate of 25 kR delivered at three different exposure rates (887 R/min, 159 R/min and 48 R/min) on soybean seeds was studied by measuring seedling height, cotyledon area, fresh weight, dry weight, Co 2 fixation and RuDP carboxylase activity. The dry weight, CO 2 fixation and irradiated imbibed groups did not show any correlation with exposure rate. Exposure rate effect was shown for the first stage out, no further correlation was observed in the subsequent stages, probably due to the recovery and repair mechanisms that take place as the seedling increases with age. The absence of an exposure rate effect on irradiated imbibed group may be explained in terms of non-detectable damage at a very high dose, since these seedlings exhibited effects that are similar to the effects of seeds exposed to an acute radiation dose. (author)

  9. Influence of phase separation on the anaerobic digestion of glucose: maximum COD turnover rate during continuous operation

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, A; Van Andel, J G; Breure, A M; Van Deursen, A

    1980-01-01

    A mineral medium containing 1% of glucose as the main carbon source was subjected to one-phase and two-phase anaerobic digestion processes under comparable conditions. The one-phase system combined acidogenic and methanogenic populations allowing a complete conversion of the carbon source into gaseous end products and biomass. The two-phase system consists of an acid reactor and a methane reactor connected in series allowing sequential acidogenesis and methanogenesis. Performance of the one-phase system is compared with that of the two-phase system. Maximum turnover of COD was determined for each system. Maximum specific sludge loading of the two-phase system was more than three times higher than that of the one-phase system. Effects of overloading each system were determined. The eco-physiological significance of phase separation is discussed briefly. (2 diagrams, 5 graphs, 41 references, 5 tables)

  10. Evaluation of adaptation to visually induced motion sickness based on the maximum cross-correlation between pulse transmission time and heart rate

    Directory of Open Access Journals (Sweden)

    Chiba Shigeru

    2007-09-01

    Full Text Available Abstract Background Computer graphics and virtual reality techniques are useful to develop automatic and effective rehabilitation systems. However, a kind of virtual environment including unstable visual images presented to wide field screen or a head mounted display tends to induce motion sickness. The motion sickness induced in using a rehabilitation system not only inhibits effective training but also may harm patients' health. There are few studies that have objectively evaluated the effects of the repetitive exposures to these stimuli on humans. The purpose of this study is to investigate the adaptation to visually induced motion sickness by physiological data. Methods An experiment was carried out in which the same video image was presented to human subjects three times. We evaluated changes of the intensity of motion sickness they suffered from by a subjective score and the physiological index ρmax, which is defined as the maximum cross-correlation coefficient between heart rate and pulse wave transmission time and is considered to reflect the autonomic nervous activity. Results The results showed adaptation to visually-induced motion sickness by the repetitive presentation of the same image both in the subjective and the objective indices. However, there were some subjects whose intensity of sickness increased. Thus, it was possible to know the part in the video image which related to motion sickness by analyzing changes in ρmax with time. Conclusion The physiological index, ρmax, will be a good index for assessing the adaptation process to visually induced motion sickness and may be useful in checking the safety of rehabilitation systems with new image technologies.

  11. The effects of pre-natal-, early-life- and indirectly-initiated exposures to maximum adversities on the course of schizophrenia.

    Science.gov (United States)

    Levine, Stephen Z; Levav, Itzhak; Yoffe, Rinat; Pugachova, Inna

    2014-09-01

    The effects of pre-natal-, early-life- and indirectly-initiated exposures to protracted maximum adversity on the course of schizophrenia are unknown. To compare the aforementioned Holocaust directly exposed subgroups with an indirectly exposed subgroup on the course of schizophrenia. The study population were: Israeli Jews in-uterus or born in Nazi-occupied or dominated European nations by the end of the persecution of the Jews, who were alive in 1950, and who had a last discharge diagnosis of schizophrenia in the Israel National Psychiatric Case Registry by 2013 (N=4933). The population was disaggregated into subgroups who (1) migrated after WWII and who had (1a) pre-natal (n=584, 11.8%) and (1b) early-life (n=3709, 75.2%) initiated exposures to the maximum adversities of the Holocaust, and (2) indirectly exposed individuals to the Holocaust who migrated before the Nazi-era persecution begun (n=640, 13%). Recurrent event survival analyses were computed to examine the psychiatric re-hospitalization risk of the study subgroups, unadjusted and adjusted for age of onset of the disorder and sex. The pre-natal initiated exposure subgroup had a significantly (pPoland-born individuals, the years 1922 and 1935; and followed at least 10 years and to the year 2000. Pre-natal initiated exposure to the maximal adversity of the holocaust constitutes a consistent risk factor for a worse course of schizophrenia, a possible byproduct of neurodevelopment disruptions induced by maternal stress and/or famine and/or infections. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Joint analysis of French and Czech uranium miners: lung cancer risk at low radon exposure rates and modifying effects of time since exposure and age at exposure

    International Nuclear Information System (INIS)

    Ladislav Tomasek; Agnes Rogel; Margot Tirmarche; Dominique Laurier

    2006-01-01

    The present analysis was conducted in the frame of European project 'Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiologic and experimental data'. The overall goal of the project related to uranium miners was the evaluation of lung cancer dose-response relationship and of dose rate effects among European uranium miners exposed to low doses and low dose rates of radon decay products. In addition, modifying factors like attained age, age at exposure and time since exposure were investigated. The joint analysis of French and Czech uranium miners was conducted mainly in order to increase the statistical power and to allow a more detailed description of the variation of dose-response relationship in time. (N.C.)

  13. Joint analysis of French and Czech uranium miners: lung cancer risk at low radon exposure rates and modifying effects of time since exposure and age at exposure

    Energy Technology Data Exchange (ETDEWEB)

    Ladislav Tomasek [National Radiation Protection Institute, Prague (Czech Republic); Agnes Rogel; Margot Tirmarche; Dominique Laurier [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France)

    2006-07-01

    The present analysis was conducted in the frame of European project 'Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiologic and experimental data'. The overall goal of the project related to uranium miners was the evaluation of lung cancer dose-response relationship and of dose rate effects among European uranium miners exposed to low doses and low dose rates of radon decay products. In addition, modifying factors like attained age, age at exposure and time since exposure were investigated. The joint analysis of French and Czech uranium miners was conducted mainly in order to increase the statistical power and to allow a more detailed description of the variation of dose-response relationship in time. (N.C.)

  14. The relationship between the parameters (Heart rate, Ejection fraction and BMI) and the maximum enhancement time of ascending aorta

    International Nuclear Information System (INIS)

    Jang, Young Ill; June, Woon Kwan; Dong, Kyeong Rae

    2007-01-01

    In this study, Bolus Tracking method was used to investigate the parameters affecting the time when contrast media is reached at 100 HU (T 100 ) and studied the relationship between parameters and T 100 because the time which is reached at aorta through antecubital vein after injecting contrast media is different from person to person. Using 64 MDCT, Cadiac CT, the data were obtained from 100 patients (male: 50, female: 50, age distribution: 21⁓81, average age: 57.5) during July and September, 2007 by injecting the contrast media at 4 ml∙sec -1 through their antecubital vein except having difficulties in stopping their breath and having arrhythmia. Using Somatom Sensation Cardiac 64 Siemens, patients’ height and weight were measured to know their mean Heart rate and BMI. Ejection Fraction was measured using Argus Program at Wizard Workstation. Variances of each parameter were analyzed depending on T 100 ’s variation with multiple comparison and the correlation of Heart rate, Ejection Fraction and BMI were analyzed, as well. According to T 100 ’s variation caused by Heart rate, Ejection Fraction and BMI variations, the higher patients’ Heart Rate and Ejection Fraction were, the faster T 100 ’s variations caused by Heart Rate and Ejection Fraction were. The lower their Heart Rate and Ejection Fraction were, the slower T 100 ’s variations were, but T 100 ’s variations caused by BMI were not affected. In the correlation between T 100 and parameters, Heart Rate (p⁄0.01) and Ejection Fraction (p⁄0.05) were significant, but BMI was not significant (p¤0.05). In the Heart Rate, Ejection Fraction and BMI depending on Fast (17 sec and less), Medium (18⁓21 sec), Slow (22 sec and over) Heart Rate was significant at Fast and Slow and Ejection Fraction was significant Fast and Slow as well as Medium and Slow (p⁄0.05), but BMI was not statistically significant. Of the parameters (Heart Rate, Ejection Fraction and BMI) which would affect T 100 , Heart

  15. Exposure reduces negative bias in self-rated performance in public speaking fearful participants.

    Science.gov (United States)

    Cheng, Joyce; Niles, Andrea N; Craske, Michelle G

    2017-03-01

    Individuals with public speaking anxiety (PSA) under-rate their performance compared to objective observers. The present study examined whether exposure reduces the discrepancy between self and observer performance ratings and improved observer-rated performance in individuals with PSA. PSA participants gave a speech in front of a small audience and rated their performance using a questionnaire before and after completing repeated exposures to public speaking. Non-anxious control participants gave a speech and completed the questionnaire one time only. Objective observers watched videos of the speeches and rated performance using the same questionnaire. PSA participants underrated their performance to a greater degree than did controls prior to exposure, but also performed significantly more poorly than did controls when rated objectively. Bias significantly decreased and objective-rated performance significantly increased following completion of exposure in PSA participants, and on one performance measure, anxious participants no longer showed a greater discrepancy between self and observer performance ratings compared to controls. The study employed non-clinical student sample, but the results should be replicated in clinical anxiety samples. These findings indicate that exposure alone significantly reduces negative performance bias among PSA individuals, but additional exposure or additional interventions may be necessary to fully correct bias and performance deficits. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. A new approach to hierarchical data analysis: Targeted maximum likelihood estimation for the causal effect of a cluster-level exposure.

    Science.gov (United States)

    Balzer, Laura B; Zheng, Wenjing; van der Laan, Mark J; Petersen, Maya L

    2018-01-01

    We often seek to estimate the impact of an exposure naturally occurring or randomly assigned at the cluster-level. For example, the literature on neighborhood determinants of health continues to grow. Likewise, community randomized trials are applied to learn about real-world implementation, sustainability, and population effects of interventions with proven individual-level efficacy. In these settings, individual-level outcomes are correlated due to shared cluster-level factors, including the exposure, as well as social or biological interactions between individuals. To flexibly and efficiently estimate the effect of a cluster-level exposure, we present two targeted maximum likelihood estimators (TMLEs). The first TMLE is developed under a non-parametric causal model, which allows for arbitrary interactions between individuals within a cluster. These interactions include direct transmission of the outcome (i.e. contagion) and influence of one individual's covariates on another's outcome (i.e. covariate interference). The second TMLE is developed under a causal sub-model assuming the cluster-level and individual-specific covariates are sufficient to control for confounding. Simulations compare the alternative estimators and illustrate the potential gains from pairing individual-level risk factors and outcomes during estimation, while avoiding unwarranted assumptions. Our results suggest that estimation under the sub-model can result in bias and misleading inference in an observational setting. Incorporating working assumptions during estimation is more robust than assuming they hold in the underlying causal model. We illustrate our approach with an application to HIV prevention and treatment.

  17. Investigation of the Maximum Spin-Up Coefficients of Friction Obtained During Tests of a Landing Gear Having a Static-Load Rating of 20,000 Pounds

    Science.gov (United States)

    Batterson, Sidney A.

    1959-01-01

    An experimental investigation was made at the Langley landing loads track to obtain data on the maximum spin-up coefficients of friction developed by a landing gear having a static-load rating of 20,000 pounds. The forward speeds ranged from 0 to approximately 180 feet per second and the sinking speeds, from 2.7 feet per second to 9.4 feet per second. The results indicated the variation of the maximum spin-up coefficient of friction with forward speed and vertical load. Data obtained during this investigation are also compared with some results previously obtained for nonrolling tires to show the effect of forward speed.

  18. Probabilistic estimation of residential air exchange rates for population-based human exposure modeling

    Science.gov (United States)

    Residential air exchange rates (AERs) are a key determinant in the infiltration of ambient air pollution indoors. Population-based human exposure models using probabilistic approaches to estimate personal exposure to air pollutants have relied on input distributions from AER meas...

  19. Rates and Psychological Effects of Exposure to Family Violence among Sri Lankan University Students

    Science.gov (United States)

    Haj-Yahia, Muhammad M.; de Zoysa, Piyanjli

    2008-01-01

    Objectives: The study had two objectives: to examine the rates of exposure to family violence among students in a non-Western society, with Sri Lanka as a case study and to examine the psychological effects of their exposure. Method: Four hundred seventy six medical students in Sri Lanka were surveyed. A self-administered questionnaire was…

  20. A Firm-Specific Analysis of the Exchange-Rate Exposure of Dutch Firms

    NARCIS (Netherlands)

    A. de Jong (Abe); J. Ligterink; V. Macrae

    2002-01-01

    textabstractWe examine the relationship between exchange-rate changes and stock returns for a sample of Dutch firms over 1994-1998. We find that over 50% of the firms are significantly exposed to exchange-rate risk. Furthermore, all firms with significant exchange-rate exposure benefit from a

  1. 9 CFR 381.67 - Young chicken and squab slaughter inspection rate maximums under traditional inspection procedure.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Young chicken and squab slaughter... INSPECTION REGULATIONS Operating Procedures § 381.67 Young chicken and squab slaughter inspection rate... inspector per minute under the traditional inspection procedure for the different young chicken and squab...

  2. Comparison of hurricane exposure methods and associations with county fetal death rates, adjusting for environmental quality

    Science.gov (United States)

    Adverse effects of hurricanes are increasing as coastal populations grow and events become more severe. Hurricane exposure during pregnancy can influence fetal death rates through mechanisms related to healthcare, infrastructure disruption, nutrition, and injury. Estimation of hu...

  3. Injury of the blood-testies barrier after low-dose-rate chronic radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Young Hoon; Bae Min Ji; Lee, Chang Geun; Yang, Kwang Mo; Jur, Kyu; Kim, Jong Sun [Dongnam Institute of Radiological and Medical Science, Busan (Korea, Republic of)

    2014-04-15

    The systemic effect of radiation increases in proportionally with the dose and dose rate. Little is known concerning the relationships between harmful effects and accumulated dose, which is derived from continuous low-dose rate radiation exposure. Recent our studies show that low-dose-rate chronic radiation exposure (3.49 mGy/h) causes adverse effects in the testis at a dose of 2 Gy (6 mGy/h). However, the mechanism of the low-dose-rate 2 Gy irradiation induced testicular injury remains unclear. The present results indicate that low-dose rate chronic radiation might affect the BTB permeability, possibly by decreasing levels of ZO-1, Occludin-1, and NPC-2. Furthermore, our results suggest that there is a risk of male infertility through BTB impairment even with low-dose-rate radiation if exposure is continuous.

  4. THIDA: code system for calculation of the exposure dose rate around a fusion device

    International Nuclear Information System (INIS)

    Iida, Hiromasa; Igarashi, Masahito.

    1978-12-01

    A code system THIDA has been developed for calculation of the exposure dose rates around a fusion device. It consists of the following: one- and two-dimensional discrete ordinate transport codes; induced activity calculation code; activation chain, activation cross section, radionuclide gamma-ray energy/intensity and gamma-ray group constant files; and gamma ray flux to exposure dose rate conversion coefficients. (author)

  5. Measurements of indoor and outdoor natural radiation exposure rates in model houses

    International Nuclear Information System (INIS)

    Matsuda, Hideharu; Fukaya, Mitsuharu; Minato, Susumu

    1990-01-01

    Natural gamma-ray and cosmic-ray exposure rates were measured indoors and outdoors for 94 model houses of four housing centers in Nagoya to obtain basic data for estimation of the population dose. Influence of the structure of houses on indoor exposure rates and relationship between indoor and outdoor natural gamma-ray exposure rates were studied. Exposure rates were measured with a 1.5'' φ x 4'' NaI (Tl) scintillation counter and a 6''φ spherical plastic scintillation counter. The mean indoor natural gamma-ray exposure rate in ferro-concrete buildings was about 40% higher than that in fireproof wooden houses, about 60% higher than that in light-weight steel-framed buildings, in fireproof wooden houses, it was also about 10% higher than in light-weight steel-framed building. The ratio of indoor to outdoor natural gamma-ray exposure rate was found to be about 0.95±0.15, 0.77±0.10, and 0.72±0.13 for ferro-concrete buildings, fireproof wooden houses and light-weight steel-framed buildings, respectively. The mean indoor cosmic-ray exposure rate in ferro-concrete buildings was 2.8 μR/h, about 18% lower than the outdoors. The indoor cosmic-ray exposure rate in fireproof wooden houses and light-weight steel-framed buildings were 3.2 μR/h, about 6% lower than the outdoors. (author)

  6. Measurements of natural radiation exposure rates in various living environment, (2)

    International Nuclear Information System (INIS)

    Matsuda, Hideharu

    1991-01-01

    Natural gamma-ray and cosmic-ray exposure rates were measured indoors and outdoors for 94 model houses of housing exhibition centers in Nagoya to obtain basic data for estimation of the population dose. Influence of the structure of houses on indoor exposure rates and relationship between indoor and outdoor natural gamma-ray exposure rates were studied. Exposure rates were measured with a 1.5''φ x 4''NaI(Tl) scintillation counter and a 6''φ spherical plastic scintillation counter. The mean indoor natural gamma-ray exposure rate in ferro-concrete buildings was about 40 % higher than that in fire-proof wooden houses and about 60 % higher than that in light weight steel framed buildings; that in fire-proof wooden houses was about 10 % higher than that in light weight steel framed buildings. The ratio of indoor to outdoor natural gamma-ray exposure rate was found to be 0.95 ± 0.15, 0.77 ± 0.10 and 0.72 ± 0.13 for ferro-concrete buildings, fire-proof wooden houses and light weight steel framed buildings, respectively. The mean indoor cosmic-ray exposure rate in ferro-concrete buildings was 2.8 μR/h, which was about 18 % lower than the outdoor value. The indoor cosmic-ray exposure rate both in fire-proof wooden houses and in light weight steel framed buildings were about 3.2 μR/h, which was 6 % lower than the outdoor value. (author)

  7. Measurement of exposure dose rate by TLD in 60Co garden

    International Nuclear Information System (INIS)

    Fan Chengfang; Li Pinfang; Wu Maoliang; Zhao Quan

    1987-01-01

    The use of TLD method to measure exposure dose rate in 60 Co garden is described. As compared with chemical dosimetry, the relative deviation of measurement would not exceed 10%. The good repeatability has been proved by comparing the measurements of different times and distances with correction of decay law and 1/1 2 law. Besides, the distribution of exposure dose rate was influenced by scattering of the living plants

  8. THE EFFECT OF HYPOXIA ON THE MAXIMUM MATABOLIC RATE AND SPECIFIC DYNAMIC ACTION IN ATLANTIC COD Gadus morhua

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2010-01-01

    John Fleng Steffensen' and Anders Drud Jordan Aquaculture 2010 - San Diego - Physiological Insights Towards Improving Fish Culture. Hypoxia is an increasing problem in coastal near areas and estuaries. Hypoxia can also be a problem in aquaculture systems with a high degree of recirculating water...... reduced the Scope for Activity by 55 % in nonnoxia. In hypoxia the effect was more pronounced with a 69 % reduction of the scope for activity. In conclusion hypoxia prolong the postabsorptive state of fi sh by limiting the peak metabolic rate, causing that less food is assimilated over a certain period...

  9. Calculation of dose-rate conversion factors for external exposure to photons and electrons

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1978-01-01

    Methods are presented for the calculation of dose-rate conversion factors for external exposure to photon and electron radiation from radioactive decay. A dose-rate conversion factor is defined as the dose-equivalent rate per unit radionuclide concentration. Exposure modes considered are immersion in contaminated air, immersion in contaminated water, and irradiation from a contaminated ground surface. For each radiation type and exposure mode, dose-rate conversion factors are derived for tissue-equivalent material at the body surface of an exposed individual. In addition, photon dose-rate conversion factors are estimated for 22 body organs. The calculations are based on the assumption that the exposure medium is infinite in extent and that the radionuclide concentration is uniform. The dose-rate conversion factors for immersion in contaminated air and water then follow from the requirement that all of the energy emitted in the radioactive decay is absorbed in the infinite medium. Dose-rate conversion factors for ground-surface exposure are calculated at a reference location above a smooth, infinite plane using the point-kernel integration method and known specific absorbed fractions for photons and electrons in air

  10. Calculation on cosmic-ray muon exposure rate in non-walled concrete buildings

    International Nuclear Information System (INIS)

    Fujitaka, Kazunobu; Abe, Siro

    1984-01-01

    Computer simulations on the exposure indoors from cosmic ray muons were practiced in the framework of non-scattering and non-cascade assumptions. The model buildings were two-dimensional, rectangular, and were made of a normal concrete. A stratified structure was assumed in each building, where no mezzanine was considered. Walls were not taken into account yet. The distributions of the exposure rates in 26-story buildings were illustrated in contour maps for various sets of parameters. All of them gave basically archlike patterns. Analyses of the results showed that the exposure rate is affected most largely by the floor board thickness. The ceiling height would be an insignificant factor for short buildings. The min/max ratio of the muon exposure rate in a moderate size building was estimated to be more than 0.7. (author)

  11. Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiological and experimental data

    International Nuclear Information System (INIS)

    Timarche, M.

    2004-03-01

    Radon is a radioactive gas produced during the decay of uranium 238 that is present in soil. It was classified as a human lung carcinogen in 1988, based on evidence both from animal studies and from human studies of miners with high levels of radon exposure. Radon is present everywhere; therefore the quantification of the risk associated with exposure to it is a key public health issue. The project aimed to analyse the risk associated with radon inhalation at low doses and at low rates of exposure. It involved researchers from three different fields: epidemiology, animal experiments and mechanistic modelling and provided a unique opportunity to study the influence of dose rate, mainly in the range of low daily exposures over long periods, by analysing in parallel results from both animal and epidemiological studies. The project comprised 6 work packages (W.P.). Firstly, the partners involved in epidemiology and animal experiments worked on the validation and the analysis of the data. Secondly, the data from W.P.1 and W.P.4 were transferred to the partners involved in W.P.5 for the application of mechanistic models. In the final step a synthesis of the results was prepared. (N.C)

  12. Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiological and experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Timarche, M

    2004-03-15

    Radon is a radioactive gas produced during the decay of uranium 238 that is present in soil. It was classified as a human lung carcinogen in 1988, based on evidence both from animal studies and from human studies of miners with high levels of radon exposure. Radon is present everywhere; therefore the quantification of the risk associated with exposure to it is a key public health issue. The project aimed to analyse the risk associated with radon inhalation at low doses and at low rates of exposure. It involved researchers from three different fields: epidemiology, animal experiments and mechanistic modelling and provided a unique opportunity to study the influence of dose rate, mainly in the range of low daily exposures over long periods, by analysing in parallel results from both animal and epidemiological studies. The project comprised 6 work packages (W.P.). Firstly, the partners involved in epidemiology and animal experiments worked on the validation and the analysis of the data. Secondly, the data from W.P.1 and W.P.4 were transferred to the partners involved in W.P.5 for the application of mechanistic models. In the final step a synthesis of the results was prepared. (N.C)

  13. Should measurement of maximum urinary flow rate and residual urine volume be a part of a "minimal care" assessment programme in female incontinence?

    DEFF Research Database (Denmark)

    Sander, Pia; Mouritsen, L; Andersen, J Thorup

    2002-01-01

    OBJECTIVE: The aim of this study was to evaluate the value of routine measurements of urinary flow rate and residual urine volume as a part of a "minimal care" assessment programme for women with urinary incontinence in detecting clinical significant bladder emptying problems. MATERIAL AND METHODS....... Twenty-six per cent had a maximum flow rate less than 15 ml/s, but only 4% at a voided volume > or =200 ml. Residual urine more than 149 ml was found in 6%. Two women had chronic retention with overflow incontinence. Both had typical symptoms with continuous leakage, stranguria and chronic cystitis...

  14. Formal comment on: Myhrvold (2016) Dinosaur metabolism and the allometry of maximum growth rate. PLoS ONE; 11(11): e0163205.

    Science.gov (United States)

    Griebeler, Eva Maria; Werner, Jan

    2018-01-01

    In his 2016 paper, Myhrvold criticized ours from 2014 on maximum growth rates (Gmax, maximum gain in body mass observed within a time unit throughout an individual's ontogeny) and thermoregulation strategies (ectothermy, endothermy) of 17 dinosaurs. In our paper, we showed that Gmax values of similar-sized extant ectothermic and endothermic vertebrates overlap. This strongly questions a correct assignment of a thermoregulation strategy to a dinosaur only based on its Gmax and (adult) body mass (M). Contrary, Gmax separated similar-sized extant reptiles and birds (Sauropsida) and Gmax values of our studied dinosaurs were similar to those seen in extant similar-sized (if necessary scaled-up) fast growing ectothermic reptiles. Myhrvold examined two hypotheses (H1 and H2) regarding our study. However, we did neither infer dinosaurian thermoregulation strategies from group-wide averages (H1) nor were our results based on that Gmax and metabolic rate (MR) are related (H2). In order to assess whether single dinosaurian Gmax values fit to those of extant endotherms (birds) or of ectotherms (reptiles), we already used a method suggested by Myhrvold to avoid H1, and we only discussed pros and cons of a relation between Gmax and MR and did not apply it (H2). We appreciate Myhrvold's efforts in eliminating the correlation between Gmax and M in order to statistically improve vertebrate scaling regressions on maximum gain in body mass. However, we show here that his mass-specific maximum growth rate (kC) replacing Gmax (= MkC) does not model the expected higher mass gain in larger than in smaller species for any set of species. We also comment on, why we considered extant reptiles and birds as reference models for extinct dinosaurs and why we used phylogenetically-informed regression analysis throughout our study. Finally, we question several arguments given in Myhrvold in order to support his results.

  15. Heart Rate, Stress, and Occupational Noise Exposure among Electronic Waste Recycling Workers.

    Science.gov (United States)

    Burns, Katrina N; Sun, Kan; Fobil, Julius N; Neitzel, Richard L

    2016-01-19

    Electronic waste (e-waste) is a growing occupational and environmental health issue around the globe. E-waste recycling is a green industry of emerging importance, especially in low-and middle-income countries where much of this recycling work is performed, and where many people's livelihoods depend on this work. The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana. We interviewed 57 workers and continuously monitored their individual noise exposures and heart rates for up to 24 h. More than 40% of workers had noise exposures that exceeded recommended occupational (85 dBA) and community (70 dBA) noise exposure limits, and self-reported hearing difficulties were common. Workers also had moderate to high levels of perceived stress as measured via Cohen's Perceived Stress Scale, and reported a variety of symptoms that could indicate cardiovascular disease. Noise exposures were moderately and significantly correlated with heart rate (Spearman's ρ 0.46, p stress, and unfavorable physical working conditions. These findings suggest that occupational and non-occupational noise exposure is associated with elevations in average heart rate, which may in turn predict potential cardiovascular damage.

  16. Multi-rate Poisson tree processes for single-locus species delimitation under maximum likelihood and Markov chain Monte Carlo.

    Science.gov (United States)

    Kapli, P; Lutteropp, S; Zhang, J; Kobert, K; Pavlidis, P; Stamatakis, A; Flouri, T

    2017-06-01

    In recent years, molecular species delimitation has become a routine approach for quantifying and classifying biodiversity. Barcoding methods are of particular importance in large-scale surveys as they promote fast species discovery and biodiversity estimates. Among those, distance-based methods are the most common choice as they scale well with large datasets; however, they are sensitive to similarity threshold parameters and they ignore evolutionary relationships. The recently introduced "Poisson Tree Processes" (PTP) method is a phylogeny-aware approach that does not rely on such thresholds. Yet, two weaknesses of PTP impact its accuracy and practicality when applied to large datasets; it does not account for divergent intraspecific variation and is slow for a large number of sequences. We introduce the multi-rate PTP (mPTP), an improved method that alleviates the theoretical and technical shortcomings of PTP. It incorporates different levels of intraspecific genetic diversity deriving from differences in either the evolutionary history or sampling of each species. Results on empirical data suggest that mPTP is superior to PTP and popular distance-based methods as it, consistently yields more accurate delimitations with respect to the taxonomy (i.e., identifies more taxonomic species, infers species numbers closer to the taxonomy). Moreover, mPTP does not require any similarity threshold as input. The novel dynamic programming algorithm attains a speedup of at least five orders of magnitude compared to PTP, allowing it to delimit species in large (meta-) barcoding data. In addition, Markov Chain Monte Carlo sampling provides a comprehensive evaluation of the inferred delimitation in just a few seconds for millions of steps, independently of tree size. mPTP is implemented in C and is available for download at http://github.com/Pas-Kapli/mptp under the GNU Affero 3 license. A web-service is available at http://mptp.h-its.org . : paschalia.kapli@h-its.org or

  17. Effect of daily noise exposure monitoring on annual rates of hearing loss in industrial workers.

    Science.gov (United States)

    Rabinowitz, Peter M; Galusha, Deron; Kirsche, Sharon R; Cullen, Mark R; Slade, Martin D; Dixon-Ernst, Christine

    2011-06-01

    Occupational noise-induced hearing loss (NIHL) is prevalent, yet evidence on the effectiveness of preventive interventions is lacking. The effectiveness of a new technology allowing workers to monitor daily at-ear noise exposure was analysed. Workers in the hearing conservation program of an aluminium smelter were recruited because of accelerated rates of hearing loss. The intervention consisted of daily monitoring of at-ear noise exposure and regular feedback on exposures from supervisors. The annual rate of change in high frequency hearing average at 2, 3 and 4 KHz before intervention (2000-2004) and 4 years after intervention (2006-2009) was determined. Annual rates of loss were compared between 78 intervention subjects and 234 controls in other company smelters matched for age, gender and high frequency hearing threshold level in 2005. Individuals monitoring daily noise exposure experienced on average no further worsening of high frequency hearing (average rate of hearing change at 2, 3 and 4 KHz = -0.5 dB/year). Matched controls also showed decelerating hearing loss, the difference in rates between the two groups being significant (p hearing loss showed a similar trend but the difference was not statistically significant (p = 0.06). Monitoring daily occupational noise exposure inside hearing protection with ongoing administrative feedback apparently reduces the risk of occupational NIHL in industrial workers. Longer follow-up of these workers will help determine the significance of the intervention effect. Intervention studies for the prevention of NIHL need to include appropriate control groups.

  18. Emesis as a Screening Diagnostic for Low Dose Rate (LDR) Total Body Radiation Exposure.

    Science.gov (United States)

    Camarata, Andrew S; Switchenko, Jeffrey M; Demidenko, Eugene; Flood, Ann B; Swartz, Harold M; Ali, Arif N

    2016-04-01

    Current radiation disaster manuals list the time-to-emesis (TE) as the key triage indicator of radiation dose. The data used to support TE recommendations were derived primarily from nearly instantaneous, high dose-rate exposures as part of variable condition accident databases. To date, there has not been a systematic differentiation between triage dose estimates associated with high and low dose rate (LDR) exposures, even though it is likely that after a nuclear detonation or radiologic disaster, many surviving casualties would have received a significant portion of their total exposure from fallout (LDR exposure) rather than from the initial nuclear detonation or criticality event (high dose rate exposure). This commentary discusses the issues surrounding the use of emesis as a screening diagnostic for radiation dose after LDR exposure. As part of this discussion, previously published clinical data on emesis after LDR total body irradiation (TBI) is statistically re-analyzed as an illustration of the complexity of the issue and confounding factors. This previously published data includes 107 patients who underwent TBI up to 10.5 Gy in a single fraction delivered over several hours at 0.02 to 0.04 Gy min. Estimates based on these data for the sensitivity of emesis as a screening diagnostic for the low dose rate radiation exposure range from 57.1% to 76.6%, and the estimates for specificity range from 87.5% to 99.4%. Though the original data contain multiple confounding factors, the evidence regarding sensitivity suggests that emesis appears to be quite poor as a medical screening diagnostic for LDR exposures.

  19. Last Glacial Maximum and Lateglacial in the Polish High Tatra Mountains - Revised deglaciation chronology based on the 10Be exposure age dating

    Science.gov (United States)

    Makos, Michał; Rinterknecht, Vincent; Braucher, Régis; Tołoczko-Pasek, Anna; Arnold, Maurice; Aumaître, Georges; Bourlès, Didier; Keddadouche, Karim; Aster Team

    2018-05-01

    Deglaciation chronology of the Polish High Tatra Mountains has been reconstructed based on 10Be exposure age dating. Fifty-seven rock samples were collected from boulders located on the terminal and lateral moraines that limit the horizontal extent of the LGM and the Lateglacial glaciers in the Biała Woda and Sucha Woda catchments. The uncertainty-weighted mean age of 21.5 ± 2.5 ka obtained for the maximum terminal moraine in the Sucha Woda Valley indicates that the oldest preserved moraines were formed during the global LGM. The age population ranges between 15.1 ± 1.0 and 28.3 ± 2.0 ka, and suggests that glaciers reached their maximum position (LGM I) as early as 28-25 ka and the final stabilization of the form occurred much later possibly after melting of buried dead ice. The younger glacial oscillation (LGM II) occurred no later than 20.5 ka and is represented by well-preserved termino-lateral moraine systems in the Pańszczyca Valley. The first Lateglacial stage (LG1) in the study area is documented in the Rybi Potok Valley at the RP1 moraine (1300 m a.s.l.), which was stable at around 16.6 ± 0.3 ka. The younger LG2 stage has no defined absolute age, however, it is constrained between 16.5 and 15.5 ka by the timing of the LG3 stage. This cold event is represented by well-formed moraines in the Roztoka/Pięć Stawów Polskich, Rybi Potok and Pańszczyca valleys of which exposure age indicates their deposition between 15.0 ± 0.5 and 15.6 ± 0.1 ka. The LG1, LG2 and LG3 stages likely occurred during the Oldest Dryas cold stage (Greenland Stadial 2.1a) related to the North Atlantic cooling Heinrich Event 1. The youngest glacial oscillation is evidenced by moraines in the Pusta and Pańszczyca valleys. These moraines are composed of very large granitic blocks of which exposure ages often exhibit isotope inheritance. This is reflected by the youngest P3 moraine in the Pańszczyca Valley with a mean age of deposition close to the LGM. The R4 moraine system in

  20. Exchange Rate Exposure and Its Determinants: A Firm and Industry Analysis of the UK Companies

    OpenAIRE

    He, Jiao

    2010-01-01

    This study assesses whether the unexpected exchange rate movements volatilize the UK firms’ stock return based on the firm- and industry-level analysis, and examines whether the magnitude of the exchange rate exposure is determined by the firm-specific factors. Using a sample of 244 UK companies listed in the FTSE 350 during the test period between December 1999 and December 2009, the result documents that the exchange rate fluctuation does affect the firm value. Among the five introduced ex...

  1. Heart Rate, Stress, and Occupational Noise Exposure among Electronic Waste Recycling Workers

    Directory of Open Access Journals (Sweden)

    Katrina N. Burns

    2016-01-01

    Full Text Available Electronic waste (e-waste is a growing occupational and environmental health issue around the globe. E-waste recycling is a green industry of emerging importance, especially in low-and middle-income countries where much of this recycling work is performed, and where many people’s livelihoods depend on this work. The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana. We interviewed 57 workers and continuously monitored their individual noise exposures and heart rates for up to 24 h. More than 40% of workers had noise exposures that exceeded recommended occupational (85 dBA and community (70 dBA noise exposure limits, and self-reported hearing difficulties were common. Workers also had moderate to high levels of perceived stress as measured via Cohen’s Perceived Stress Scale, and reported a variety of symptoms that could indicate cardiovascular disease. Noise exposures were moderately and significantly correlated with heart rate (Spearman’s ρ 0.46, p < 0.001. A mixed effects linear regression model indicated that a 1 dB increase in noise exposure was associated with a 0.17 increase in heart rate (p-value = 0.01 even after controlling for work activities, age, smoking, perceived stress, and unfavorable physical working conditions. These findings suggest that occupational and non-occupational noise exposure is associated with elevations in average heart rate, which may in turn predict potential cardiovascular damage.

  2. Radiation exposure rate and liquid level measurement inside a high level liquid waste (HLLW) storage tank

    International Nuclear Information System (INIS)

    Sur, B.; Yue, S.; Thekkevarriam, A.

    2007-01-01

    An instrument based on an inexpensive, small silicon diode has been developed and used to measure, for the first time, the gamma radiation exposure rate profile inside a 6.4 mm diameter reentrant thermo-well tube, immersed in the highly radioactive liquid solution in an HLLW storage tank. The measurement agrees with previous calculations of exposure rate, and provides confirmation for safe and effective radiation work plans and material selection for investigations and remediation of the storage tank facility. The measured radiation exposure rate profile is also used to confirm that the position of tank internal structures have not changed because of aging and corrosion, and to obtain, within a few mm, the level of liquid inside the tank. (author)

  3. Dose-rate effects of ethylene oxide exposure on developmental toxicity.

    Science.gov (United States)

    Weller, E; Long, N; Smith, A; Williams, P; Ravi, S; Gill, J; Henessey, R; Skornik, W; Brain, J; Kimmel, C; Kimmel, G; Holmes, L; Ryan, L

    1999-08-01

    In risk assessment, evaluating a health effect at a duration of exposure that is untested involves assuming that equivalent multiples of concentration (C) and duration (T) of exposure have the same effect. The limitations of this approach (attributed to F. Haber, Zur Geschichte des Gaskrieges [On the history of gas warfare], in Funf Vortrage aus den Jahren 1920-1923 [Five lectures from the years 1920-1923], 1924, Springer, Berlin, pp. 76-92), have been noted in several studies. The study presented in this paper was designed to specifically look at dose-rate (C x T) effects, and it forms an ideal case study to implement statistical models and to examine the statistical issues in risk assessment. Pregnant female C57BL/6J mice were exposed, on gestational day 7, to ethylene oxide (EtO) via inhalation for 1.5, 3, or 6 h at exposures that result in C x T multiples of 2100 or 2700 ppm-h. EtO was selected because of its short half-life, documented developmental toxicity, and relevance to exposures that occur in occupational settings. Concurrent experiments were run with animals exposed to air for similar periods. Statistical analysis using models developed to assess dose-rate effects revealed significant effects with respect to fetal death and resorptions, malformations, crown-to-rump length, and fetal weight. Animals exposed to short, high exposures of EtO on day 7 of gestation were found to have more adverse effects than animals exposed to the same C x T multiple but at longer, lower exposures. The implication for risk assessment is that applying Haber's Law could potentially lead to an underestimation of risk at a shorter duration of exposure and an overestimation of risk at a longer duration of exposure. Further research, toxicological and statistical, are required to understand the mechanism of the dose-rate effects, and how to incorporate the mechanistic information into the risk assessment decision process.

  4. E-Commerce and Exchange Rate Exposure Management: A Tilt towards Real Hedging

    DEFF Research Database (Denmark)

    Aabo, Tom

    2001-01-01

    The aim of this paper is to address the impact of E-commerce on the balance between real hedging and financial hedging in the context of exchange rate exposure management in non-financial companies. A cross-case study of industrial companies highlights the inadequacy in taking a partial and static...... financial approach when managing exchange rate exposures. The paper argues that the emergence of E-commerce - by reducing the cost of obtaining, analyzing and allocating information - affects the dynamics of the markets and the dynamics of the company in such a way that a general tilt towards real hedging...

  5. Influence of radon daughter exposure rate, unattachment fraction, and disequilibrium on occurrence of lung tumours

    International Nuclear Information System (INIS)

    Cross, F.T.; Palmer, R.F.; Dagle, G.E.; Busch, R.H.; Buschbom, R.L.

    1984-01-01

    Groups of male, specific-pathogen-free (SPF), Wistar rats were exposed to several concentrations of radon daughters and uranium ore dust to clarify the roles of exposure rate, unattached RaA daughters, and the degree of radon daughter disequilibrium, in the development of respiratory system disease. Modelled, human dosimetric data indicate that the dose to sensitive tissues of the respiratory tract increases with increasing radon daughter unattachment fraction and degree of disequilibrium. Data bearing on these developments as well as updated results of experiments designed to test the role of radon daughter exposure rate on lung tumour incidence are reported. (author)

  6. Measurement of environmental radiation exposure rates from Vernita, Hanford Reach, and Richland area shores. Addendum 1

    International Nuclear Information System (INIS)

    Cooper, A.T.

    1995-02-01

    Environmental radiation exposure rate measurements are taken on and around the Hanford Site for Pacific Northwest Laboratory's Hanford Site Surface Environmental Surveillance Project. In 1992, environmental radiation exposure rate measurements were taken from shoreline and island areas ranging from Vernita, along the Hanford Reach, down to the Richland Pumphouse. Measurements were taken primarily at locations known or expected to have elevated exposure rates as determined by examination of aerial photographs depicting radiation exposure measurements. Results from the 1992 survey indicated radiation exposure rates taken from the Hanford Reach area were elevated in comparison to the measurements taken from the Vernita area with ranges of 8 to 28 μR/hr and 4 to 11 μR/hr, respectively. In January 1994, additional shoreline radiation exposure rate measurements were taken from the Vernita, Hanford Reach, and Richland areas to determine the relationship of radiation exposure rates along the Richland area shores when compared to Vernita and Hanford Reach area exposure rates (measurements along the Richland area were not collected during the 1992 survey). This report discusses the 1994 results and is an addendum to the report that discussed the 1992 survey. An analysis of variance indicated a significant location interaction at a p-value of 0.0014. To determine differences between paried locations a post-hoc comparison of location means was performed on log transformed data using the Scheffacute e's F-test. This test indicated a significant difference between Hanford Reach and Richland area means with a mean difference of 0.075 /μR/hr and a p-value of 0.0014. No significant difference was found between Hanford Reach and Vernita area means: The mean difference was 0.031 μR/hr and the p-value was 0.3138. No significant difference was found between Vernita and Richland area means with a mean difference of 0.044 μR/hr and a p-value of 0.1155

  7. The last generation of contamination and exposure rate meters and monitors designed in Boris Kidric Institute

    International Nuclear Information System (INIS)

    Koturovic, A.M.; Sobajic, M.V.; Smelcerovic, M.A.; Damljanovic, D.D.; Drndarevic, V.R.

    1989-01-01

    The last generation of contamination and exposure rate meters and monitors designed and produced in Boris Kidric Institute, presented in this paper, are digital survey instruments. The common principle of these instruments is the 'simple precision' concept, i.e. predetermined time pulse counting. This principle is discussed and basic structure of these instruments is shown with their possibilities and features (author)

  8. The Importance of Corporate Foreign Debt in Managing Exchange Rate Exposure in Non-Financial Companies

    DEFF Research Database (Denmark)

    Aabo, Tom

    2006-01-01

    This empirical study of the exchange rate exposure management of Danish non-financial firms listed on the Copenhagen Stock Exchange shows that debt denominated in foreign currency (foreign debt) is a very important alternative to the use of currency derivatives. The results show that the relative...

  9. Determination of x-radiation exposure rates from color television sets

    International Nuclear Information System (INIS)

    Campos, L.L.; Caldas, L.V.E.

    1988-05-01

    The exposure rates of low energy X-rays emitted from color televisions were determined by thermoluminescence using CaSO 4 :Dy + Teflon pellets. The measurements were taken at the distances of 5 cm, 2 and 3 m in front of the screens. The results were compared with those obtained for video display terminals at the same experimental conditions. (author) [pt

  10. A simulation study of Linsley's approach to infer elongation rate and fluctuations of the EAS maximum depth from muon arrival time distributions

    International Nuclear Information System (INIS)

    Badea, A.F.; Brancus, I.M.; Rebel, H.; Haungs, A.; Oehlschlaeger, J.; Zazyan, M.

    1999-01-01

    The average depth of the maximum X m of the EAS (Extensive Air Shower) development depends on the energy E 0 and the mass of the primary particle, and its dependence from the energy is traditionally expressed by the so-called elongation rate D e defined as change in the average depth of the maximum per decade of E 0 i.e. D e = dX m /dlog 10 E 0 . Invoking the superposition model approximation i.e. assuming that a heavy primary (A) has the same shower elongation rate like a proton, but scaled with energies E 0 /A, one can write X m = X init + D e log 10 (E 0 /A). In 1977 an indirect approach studying D e has been suggested by Linsley. This approach can be applied to shower parameters which do not depend explicitly on the energy of the primary particle, but do depend on the depth of observation X and on the depth X m of shower maximum. The distribution of the EAS muon arrival times, measured at a certain observation level relatively to the arrival time of the shower core reflect the pathlength distribution of the muon travel from locus of production (near the axis) to the observation locus. The basic a priori assumption is that we can associate the mean value or median T of the time distribution to the height of the EAS maximum X m , and that we can express T = f(X,X m ). In order to derive from the energy variation of the arrival time quantities information about elongation rate, some knowledge is required about F i.e. F = - ∂ T/∂X m ) X /∂(T/∂X) X m , in addition to the variations with the depth of observation and the zenith-angle (θ) dependence, respectively. Thus ∂T/∂log 10 E 0 | X = - F·D e ·1/X v ·∂T/∂secθ| E 0 . In a similar way the fluctuations σ(X m ) of X m may be related to the fluctuations σ(T) of T i.e. σ(T) = - σ(X m )· F σ ·1/X v ·∂T/∂secθ| E 0 , with F σ being the corresponding scaling factor for the fluctuation of F. By simulations of the EAS development using the Monte Carlo code CORSIKA the energy and angle

  11. A review of air exchange rate models for air pollution exposure assessments.

    Science.gov (United States)

    Breen, Michael S; Schultz, Bradley D; Sohn, Michael D; Long, Thomas; Langstaff, John; Williams, Ronald; Isaacs, Kristin; Meng, Qing Yu; Stallings, Casson; Smith, Luther

    2014-11-01

    A critical aspect of air pollution exposure assessments is estimation of the air exchange rate (AER) for various buildings where people spend their time. The AER, which is the rate of exchange of indoor air with outdoor air, is an important determinant for entry of outdoor air pollutants and for removal of indoor-emitted air pollutants. This paper presents an overview and critical analysis of the scientific literature on empirical and physically based AER models for residential and commercial buildings; the models highlighted here are feasible for exposure assessments as extensive inputs are not required. Models are included for the three types of airflows that can occur across building envelopes: leakage, natural ventilation, and mechanical ventilation. Guidance is provided to select the preferable AER model based on available data, desired temporal resolution, types of airflows, and types of buildings included in the exposure assessment. For exposure assessments with some limited building leakage or AER measurements, strategies are described to reduce AER model uncertainty. This review will facilitate the selection of AER models in support of air pollution exposure assessments.

  12. Potential radiological exposure rates resulting from hypothetical dome failure at Tank W-10

    International Nuclear Information System (INIS)

    1994-07-01

    The main plant area at Oak Ridge National Laboratory (ORNL) contains 12 buried Gunite tanks that were used for the storage and transfer of liquid radioactive waste. Although the tanks are no longer in use, they are known to contain some residual contaminated sludges and liquids. In the event of an accidental tank dome failure, however unlikely, the liquids, sludges, and radioactive contaminants within the tank walls themselves could create radiation fields and result in above-background exposures to workers nearby. This Technical Memorandum documents a series of calculations to estimate potential radiological exposure rates and total exposures to workers in the event of a hypothetical collapse of a Gunite tank dome. Calculations were performed specifically for tank W-10 because it contains the largest radioactivity inventory (approximately half of the total activity) of all the Gunite tanks. These calculations focus only on external, direct gamma exposures for prescribed, hypothetical exposure scenarios and do not address other possible tank failure modes or routes of exposure. The calculations were performed with established, point-kernel gamma ray modeling codes

  13. Exposure Time Distributions reveal Denitrification Rates along Groundwater Flow Path of an Agricultural Unconfined Aquifer

    Science.gov (United States)

    Kolbe, T.; Abbott, B. W.; Thomas, Z.; Labasque, T.; Aquilina, L.; Laverman, A.; Babey, T.; Marçais, J.; Fleckenstein, J. H.; Peiffer, S.; De Dreuzy, J. R.; Pinay, G.

    2016-12-01

    Groundwater contamination by nitrate is nearly ubiquitous in agricultural regions. Nitrate is highly mobile in groundwater and though it can be denitrified in the aquifer (reduced to inert N2 gas), this process requires the simultaneous occurrence of anoxia, an electron donor (e.g. organic carbon, pyrite), nitrate, and microorganisms capable of denitrification. In addition to this the ratio of the time groundwater spent in a denitrifying environment (exposure time) to the characteristic denitrification reaction time plays an important role, because denitrification can only occur if the exposure time is longer than the characteristic reaction time. Despite a long history of field studies and numerical models, it remains exceedingly difficult to measure or model exposure times in the subsurface at the catchment scale. To approach this problem, we developed a unified modelling approach combining measured environmental proxies with an exposure time based reactive transport model. We measured groundwater age, nitrogen and sulfur isotopes, and water chemistry from agricultural wells in an unconfined aquifer in Brittany, France, to quantify changes in nitrate concentration due to dilution and denitrification. Field data showed large differences in nitrate concentrations among wells, associated with differences in the exposure time distributions. By constraining a catchment-scale characteristic reaction time for denitrification with water chemistry proxies and exposure times, we were able to assess rates of denitrification along groundwater flow paths. This unified modeling approach is transferable to other catchments and could be further used to investigate how catchment structure and flow dynamics interact with biogeochemical processes such as denitrification.

  14. Potential radiological exposure rates resulting from hypothetical dome failure at Tank W-10

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The main plant area at Oak Ridge National Laboratory (ORNL) contains 12 buried Gunite tanks that were used for the storage and transfer of liquid radioactive waste. Although the tanks are no longer in use, they are known to contain some residual contaminated sludges and liquids. In the event of an accidental tank dome failure, however unlikely, the liquids, sludges, and radioactive contaminants within the tank walls themselves could create radiation fields and result in above-background exposures to workers nearby. This Technical Memorandum documents a series of calculations to estimate potential radiological exposure rates and total exposures to workers in the event of a hypothetical collapse of a Gunite tank dome. Calculations were performed specifically for tank W-10 because it contains the largest radioactivity inventory (approximately half of the total activity) of all the Gunite tanks. These calculations focus only on external, direct gamma exposures for prescribed, hypothetical exposure scenarios and do not address other possible tank failure modes or routes of exposure. The calculations were performed with established, point-kernel gamma ray modeling codes.

  15. Air pollution and heart rate variability: effect modification by chronic lead exposure.

    Science.gov (United States)

    Park, Sung Kyun; O'Neill, Marie S; Vokonas, Pantel S; Sparrow, David; Wright, Robert O; Coull, Brent; Nie, Huiling; Hu, Howard; Schwartz, Joel

    2008-01-01

    Outdoor air pollution and lead exposure can disturb cardiac autonomic function, but the effects of both these exposures together have not been studied. We examined whether higher cumulative lead exposures, as measured by bone lead, modified cross-sectional associations between air pollution and heart rate variability among 384 elderly men from the Normative Aging Study. We used linear regression, controlling for clinical, demographic, and environmental covariates. We found graded, significant reductions in both high-frequency and low-frequency powers of heart rate variability in relation to ozone and sulfate across the quartiles of tibia lead. Interquartile range increases in ozone and sulfate were associated respectively, with 38% decrease (95% confidence interval = -54.6% to -14.9%) and 22% decrease (-40.4% to 1.6%) in high frequency, and 38% decrease (-51.9% to -20.4%) and 12% decrease (-28.6% to 9.3%) in low frequency, in the highest quartile of tibia lead after controlling for potential confounders. We observed similar but weaker effect modification by tibia lead adjusted for education and cumulative traffic (residuals of the regression of tibia lead on education and cumulative traffic). Patella lead modified only the ozone effect on heart rate variability. People with long-term exposure to higher levels of lead may be more sensitive to cardiac autonomic dysfunction on high air pollution days. Efforts to understand how environmental exposures affect the health of an aging population should consider both current levels of pollution and history of lead exposure as susceptibility factors.

  16. In-situ real time measurements of net erosion rates of copper during hydrogen plasma exposure

    Science.gov (United States)

    Kesler, Leigh; Wright, Graham; Peterson, Ethan; Whyte, Dennis

    2013-10-01

    In order to properly understand the dynamics of net erosion/deposition in fusion reactors, such as tokamaks, a diagnostic measuring the real time rates of net erosion/deposition during plasma exposure is necessary. The DIONISOS experiment produces real time measurements of net erosion/deposition by using Rutherford backscattering spectroscopy (RBS) ion beam analysis simultaneously with plasma exposure from a helicon plasma source. This in-situ method improves on ex-situ weight loss measurements by allowing measurement of possible synergistic effects of high ion implantation rates and net erosion rate and by giving a real time response to changes in plasma parameters. Previous work has validated this new technique for measuring copper (Cu) erosion from helium (He) plasma ion bombardment. This technique is now extended to measure copper erosion due to deuterium and hydrogen plasma ion exposure. Targets used were a 1.5 μm Cu layer on an aluminum substrate. Cu layer thickness is tracked in real time using 1.2 MeV proton RBS. Measured erosion rates will be compared to results from literature and He erosion rates. Supported by US DoE award DE-SC00-02060.

  17. Measurements of national radiation exposure rates on train lines in Tokai area

    International Nuclear Information System (INIS)

    Matsuda, Hideharu

    1996-01-01

    For data accumulation of natural radiation exposure rate derived from gamma-ray and cosmic-ray to evaluate population dose, the author measured the rate in the running vehicles of 12 JR Tokai lines, 17 Nagoya Railway lines, 4 Kinkinippon Railway lines and 1 line of Nagoya City Bus. A portable gamma spectrometer equipped with 3' in diameter x 3' NaI (Tl) scintillation detector was placed on the seat of the vehicle for measurement in the period of December, 1992-August, 1995. Gamma-ray and cosmic-ray exposure rates in air were assessed separately as reported before and expressed in Gy/h. The average exposure rate of gamma-ray in JR Tokai lines was 19.8 nGy/h and of cosmic-ray, 28.5 nGy/h, both of which were markedly varied from line to line. The average rates of gamma-and cosmic-ray were 21.6 nGy/h and 29.0 nGy/h, respectively, in Nagoya Railway lines and 20.9 nGy/h and 28.7 nGy/h, respectively, in Kinkinippon lines. In the city bus, the respective rates were 27.2 nGy/h and 27.0 nGy/h. Thus, the average rates of gamma-ray (about 20 nGy/h) and cosmic-ray (about 29 nGy/h) were not so different between JR and other private railway lines. In the bus, the former rate was slightly lower and the latter, slightly higher. However, the total rates of both rays were in the range of about 50-55 nGy/h in all vehicles examined. (H.O.)

  18. Water requirements and drinking rates of homing pigeons: A consideration for exposure risk of migratory birds.

    Science.gov (United States)

    Perez, Cristina R; Moye, John K; Pritsos, Chris A

    2017-09-01

    Access to water along a bird's migratory flyway is essential during the vital process of migration. Because of the scarcity of water in some environments, there is potential for migratory birds to encounter and drink from contaminated bodies of water. Ingestion of contaminated water may cause injury and compromise flying ability, leading to a disruption of migration. To determine injury to birds from potential exposure, it is essential to know not only the concentration of a given contaminant in the water but also the quantity and rate of water consumption by the birds. Homing pigeons (Columba livia) were used in a series of experiments to determine differences in drinking behavior after various flights and after periods of resting. Results from the present study demonstrate that homing pigeons' water consumption is dramatically different when assessed according to activity, flight distance, and time elapsed after flight. This suggests that the drinking rates of birds during migration are extremely important and much greater than estimated using traditional exposure assessment procedures. Thus, exposure to contaminants via drinking water may be greatly underestimated, and the rate of water consumption should be considered when estimating potential exposure risk to avian species. Integr Environ Assess Manag 2017;13:870-876. © 2017 SETAC. © 2017 SETAC.

  19. The effects of exposure to environmental factors on Heart Rate Variability: An ecological perspective

    International Nuclear Information System (INIS)

    Schnell, Izhak; Potchter, Oded; Epstein, Yoram; Yaakov, Yaron; Hermesh, Hagai; Brenner, Shmuel; Tirosh, Emanuel

    2013-01-01

    The impact of human exposure to environmental factors on Heart Rate Variability (HRV) was examined in the urban space of Tel-Aviv-Jaffa. Four environmental factors were investigated: thermal and social loads; CO concentrations and noise. Levels of HRV are explained mainly by subjective social stresses, noise and CO. The most interesting result is the fact that while subjective social stress and noise increase HRV, low levels of CO are reducing HRV to some extent moderating the impact of subjective social stress and noise. Beyond the poisoning effect of CO and the fact that extremely low levels of HRV associated with high dozes of CO increase risk for life, low levels of CO may have a narcotic effect, as it is measured by HRV. The effects of thermal loads on HRV are negligible probably due to the use of behavioral means in order to neutralize heat and cold effects. -- Highlights: ► The impact of human exposure to environmental factors on Heart Rate Variability (HRV) was examined. ► Previous studies measured human exposure to pollution by fixed monitoring stations. ► This study measured actual personal exposure by mini sensors. ► High level of subjective social load and noise increase HRV. ► Low levels of CO may have a narcotic effect, as it is measured by HRV. -- The research focuses on the effects of environmental factors; noise, subjective social stress, thermal load and CO on Heart Rate Variability

  20. Dose-rate models for human survival after exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Jones, T.D.; Morris, M.D.; Young, R.W.

    1987-01-01

    This paper reviews new estimates of the LD 50 in man by Mole and by Rotblat, the biological processes contributing to hematologic death, the collection of animal experiments dealing with hematologic death, and the use of regression analysis to make new estimates of human mortality based on all relevant animal studies. Regression analysis of animal mortality data has shown that mortality is dependent strongly on dose rate, species, body weight, and time interval over which the exposure is delivered. The model has predicted human LD 50 s of 194, 250, 310, and 360 rad to marrow when the exposure time is a minute, an hour, a day, and a week, respectively

  1. Estimation of exposure to 222Rn from the excretion rates of 21πPb

    International Nuclear Information System (INIS)

    Holtzman, R.B.; Rundo, J.

    1981-01-01

    A model is proposed with which estimates of exposure to 227 Rn and its daughter products may be made from urinary excretion rates of 210 Pb. It is assumed that 20% of all the 210 Pb inhaled reaches the blood and that 50% of the endogenous excretion is through the urine. The estimates from the model are compared with the results of measurements on a subject residing in a house with high levels of radon. Whole body radioactivity and excretion data were consistent with the model, but the estimates of exposure (WL) were higher than those measured with an Environmental Working Level Monitor

  2. Dose-rate models for human survival after exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Jones, T.D.; Morris, M.D.; Young, R.W.

    1986-01-01

    This paper reviews new estimates of the L 50 in man by Mole and by Rotblat, the biological processes contributing to hematologic death, the collection of animal experiments dealing with hematologic death, and the use of regression analysis to make new estimates of human mortality based on all relevant animal studies. Regression analysis of animal mortality data has shown that mortality is dependent strongly on dose rate, species, body weight, and time interval over which the exposure is delivered. The model has predicted human LD 50 s of 194, 250, 310, and 360 rad to marrow when the exposure time is a minute, an hour, a day, and a week, respectively

  3. Measuring maximum and standard metabolic rates using intermittent-flow respirometry: a student laboratory investigation of aerobic metabolic scope and environmental hypoxia in aquatic breathers.

    Science.gov (United States)

    Rosewarne, P J; Wilson, J M; Svendsen, J C

    2016-01-01

    Metabolic rate is one of the most widely measured physiological traits in animals and may be influenced by both endogenous (e.g. body mass) and exogenous factors (e.g. oxygen availability and temperature). Standard metabolic rate (SMR) and maximum metabolic rate (MMR) are two fundamental physiological variables providing the floor and ceiling in aerobic energy metabolism. The total amount of energy available between these two variables constitutes the aerobic metabolic scope (AMS). A laboratory exercise aimed at an undergraduate level physiology class, which details the appropriate data acquisition methods and calculations to measure oxygen consumption rates in rainbow trout Oncorhynchus mykiss, is presented here. Specifically, the teaching exercise employs intermittent flow respirometry to measure SMR and MMR, derives AMS from the measurements and demonstrates how AMS is affected by environmental oxygen. Students' results typically reveal a decline in AMS in response to environmental hypoxia. The same techniques can be applied to investigate the influence of other key factors on metabolic rate (e.g. temperature and body mass). Discussion of the results develops students' understanding of the mechanisms underlying these fundamental physiological traits and the influence of exogenous factors. More generally, the teaching exercise outlines essential laboratory concepts in addition to metabolic rate calculations, data acquisition and unit conversions that enhance competency in quantitative analysis and reasoning. Finally, the described procedures are generally applicable to other fish species or aquatic breathers such as crustaceans (e.g. crayfish) and provide an alternative to using higher (or more derived) animals to investigate questions related to metabolic physiology. © 2016 The Fisheries Society of the British Isles.

  4. Evaluation of the external radiation exposure dosimetry and calculation of maximum permissible concentration values for airborne materials containing 18F, 15O, 13N, 11C and 133Xe

    International Nuclear Information System (INIS)

    Piltingsrud, H.V.; Gels, G.L.

    1985-01-01

    To better understand the dose equivalent (D.E.) rates produced by airborne releases of gaseous positron-emitting radionuclides under various conditions of cloud size, a study of the external radiation exposure dosimetry of these radionuclides, as well as negatron, gamma and x-ray emitting 133Xe, was undertaken. This included a calculation of the contributions to D.E. as a function of cloud radii, at tissue depths of 0.07 mm (skin), 3 mm (lens of eye) and 10 mm (whole body) from both the particulate and photon radiations emitted by these radionuclides. Estimates of maximum permissible concentration (MPC) values were also calculated based on the calculated D.E. rates and current regulations for personnel radiation protection (CFR84). Three continuous air monitors, designed for use with 133Xe, were evaluated for applications in monitoring air concentrations of the selected positron emitters. The results indicate that for a given radionuclide and for a cloud greater than a certain radius, personnel radiation dosimeters must respond acceptably to only the photon radiations emitted by the radionuclide to provide acceptable personnel dosimetry. For clouds under that radius, personnel radiation dosimeters must also respond acceptably to the positron or negatron radiations to provide acceptable personnel dosimetry. It was found that two out of the three air concentration monitors may be useful for monitoring air concentrations of the selected positron emitters

  5. Rating the Raters: Legal Exposure of Trustmark Authorities in the Context of Consumer Health Informatics

    Science.gov (United States)

    2000-01-01

    There are three areas of potential legal exposure for an organization such as a trustmark authority involved in e-health quality rating. First, an e-health provider may make a complaint about negative or impliedly negative ratings rendered by the ratings body (false negative). Typically, a negative ratings complaint would rely on defamation or product disparagement causes of action. In some cases such complaints could be defended on the basis of absence of malice (US). Second, the rating body might render a positive rating on e-health data that a third party allegedly relied upon and suffered injury (false positive). While the primary cause of action would be against the e-health data provider, questions may arise as to the possible liability of the trustmark authority. For example, some US liability exposure is possible based on cases involving the potential liability of product warrantors, trade associations, and certifiers or endorsers. Third, a ratings body may face public law liability for its own web misfeasance. Several risk management approaches are possible and would not necessarily be mutually exclusive. These approaches will require careful investigation to assess their risk reduction potential and, in some cases, the introduction of legislation. PMID:11720941

  6. Rating the "Raters": Legal Exposure of Trustmark Authorities in the Context of Consumer Health Informatics

    Science.gov (United States)

    Terry, Nicolas P

    2000-01-01

    There are three areas of potential legal exposure for an organization such as a trustmark authority involved in ehealth quality rating. First, an ehealth provider may make a complaint about negative or impliedly negative ratings rendered by the ratings body (false negative). Typically, a negative ratings complaint would rely on defamation or product disparagement causes of action. In some cases such complaints could be defended on the basis of absence of malice (US). Second, the rating body might render a positive rating on ehealth data that a third party allegedly relied upon and suffered injury (false positive). While the primary cause of action would be against the ehealth data provider, questions may arise as to possible liability of the trustmark authority. For example, some US liability exposure is possible based on cases involving the potential liability of product warrantors, trade associations and certifiers or endorsers. Third, a ratings body may face public law liability for its own web misfeasance. Several risk management approaches are possible and would not necessarily be mutually exclusive. These approaches will require careful investigation to assess their risk reduction potential and, in some cases, legislation.

  7. Association of arsenic exposure with lung cancer incidence rates in the United States.

    Directory of Open Access Journals (Sweden)

    Joseph J Putila

    Full Text Available Although strong exposure to arsenic has been shown to be carcinogenic, its contribution to lung cancer incidence in the United States is not well characterized. We sought to determine if the low-level exposures to arsenic seen in the U.S. are associated with lung cancer incidence after controlling for possible confounders, and to assess the interaction with smoking behavior.Measurements of arsenic stream sediment and soil concentration obtained from the USGS National Geochemical Survey were combined, respectively, with 2008 BRFSS estimates on smoking prevalence and 2000 U.S. Census county level income to determine the effects of these factors on lung cancer incidence, as estimated from respective state-wide cancer registries and the SEER database. Poisson regression was used to determine the association between each variable and age-adjusted county-level lung cancer incidence. ANOVA was used to assess interaction effects between covariates.Sediment levels of arsenic were significantly associated with an increase in incident cases of lung cancer (P<0.0001. These effects persisted after controlling for smoking and income (P<0.0001. Across the U.S., exposure to arsenic may contribute to up to 5,297 lung cancer cases per year. There was also a significant interaction between arsenic exposure levels and smoking prevalence (P<0.05.Arsenic was significantly associated with lung cancer incidence rates in the U.S. after controlling for smoking and income, indicating that low-level exposure to arsenic is responsible for excess cancer cases in many parts of the U.S. Elevated county smoking prevalence strengthened the association between arsenic exposure and lung cancer incidence rate, an effect previously unseen on a population level.

  8. Exposure rate measurements and radiation control in post therapy with I131

    International Nuclear Information System (INIS)

    Vazquez A, M.; Castillo D, C.; Flores U, H.; Cespedes C, L.; Morgan N, C.; Sifuentes D, Y.; Marin R, K.

    2015-10-01

    During hyperthyroidism treatment, 131 I activities from 111 MBq up to 296 MBq are used. In the aim to determine if the 131 I uptake by the patient is a radiological risk to family members and public around the patient exposure rate measurements were carried out, using a limit 1.8 m R/h. Measurements were carried out in the Nuclear Medicine department of Almenara hospital in Lima, Peru. The exposure rate was measured to 0.3, 0.6, and 1.0 m from the patient from 0 to 11 days after post-administrated dose (Pda). In this study measurements were carried out in 21 hyperthyroid patients. Measurements to 1 meter, along 2-4 (16/16), 5-7 (15/15), and 8-11 (14/14) days after Pda, indicate the dose rate around 100% of patients is ≤ 1.8 m R /h. Measurements to 0.6 meters along 2-4 (16/16), 5 -7 (15/15), and 8-11 (14/14) days after Pda, indicate that the dose rate around 44% (7/16), 93% (14/15), and 100% (14/14) of patients is ≤ 1.8 m R h. On the other hand, dose rate measurements to 0.3 meters, along 2-4 (16/16), 5-7 (15/15), and 8 -11 (14/14) days after Pda, indicate that de dose rate is 13% (2/16), 6% (1/15), and 43% (6/14) of patients is ≤ 1.8 m R/h. Measured exposure rates are alike to values reported in the literature, and were used to define radiation control recommendations. (Author)

  9. Lung cancer incidence after exposure of rats to low doses of radon: influence of dose rate

    Energy Technology Data Exchange (ETDEWEB)

    Morlier, J.P.; Morin, M.; Monchaux, G.; Fritsch, P.; Lafuma, J.; Masse, R. [CEA Centre d`Etudes Nucleaires de Fontenay-aux-Roses, 92 (France). Dept. de Protection Technique; Pineau, J.F. [ALGADE, Bessines (France); Chameaud, J. [Compagnie Generale des Matieres Nucleaires (COGEMA), 87 - Razes (France)

    1994-12-31

    To study the effect on lung cancer incidence of a long exposure to low levels of radon, 500 male 3-months-old Sprague-Dawley rats, were exposed to a cumulative dose of 25 WLM of radon and its daughters, 6 hours a day, 5 days a week, during 18 months. Exposure conditions were controlled in order to maintain a defined PAEC: 42 x 10{sup 6} J.m{sup -3} (2 WL), in the range of domestic and environmental exposures. Animals were kept until they died or given euthanasia when moribund. Mean survival times were similar in both irradiated and control groups: 828 days (SD = 169) and 830 days (SD = 137), as well as lung cancer incidence, 0.60% at 25 WLM and 0.63% for controls. The incidence of lung lesions was compared statistically with controls and those previously obtained at cumulative exposures of 25 and 50 WLM delivered over a 4-6 month period, inducing a significant increase of lung cancer, 2.2% and 3.8% respectively. Such a comparison showed a decreased lung cancer incidence related to a decrease in the dose rate for low levels of radon exposure. (author).

  10. Lung cancer incidence after exposure of rats to low doses of radon: influence of dose rate

    International Nuclear Information System (INIS)

    Morlier, J.P.; Morin, M.; Monchaux, G.; Fritsch, P.; Lafuma, J.; Masse, R.; Chameaud, J.

    1994-01-01

    To study the effect on lung cancer incidence of a long exposure to low levels of radon, 500 male 3-months-old Sprague-Dawley rats, were exposed to a cumulative dose of 25 WLM of radon and its daughters, 6 hours a day, 5 days a week, during 18 months. Exposure conditions were controlled in order to maintain a defined PAEC: 42 x 10 6 J.m -3 (2 WL), in the range of domestic and environmental exposures. Animals were kept until they died or given euthanasia when moribund. Mean survival times were similar in both irradiated and control groups: 828 days (SD = 169) and 830 days (SD = 137), as well as lung cancer incidence, 0.60% at 25 WLM and 0.63% for controls. The incidence of lung lesions was compared statistically with controls and those previously obtained at cumulative exposures of 25 and 50 WLM delivered over a 4-6 month period, inducing a significant increase of lung cancer, 2.2% and 3.8% respectively. Such a comparison showed a decreased lung cancer incidence related to a decrease in the dose rate for low levels of radon exposure. (author)

  11. Derivation of pulse height to exposure rate conversion functions for aerial radiological surveys

    International Nuclear Information System (INIS)

    Artuso, J.F.

    1985-01-01

    A method is described for deriving conversion functions that can be used to convert pulse height spectra taken at altitude to the exposure rate at the 1-m level. An integral equation is set up which involves the integration of a calculated pulse height spectrum multiplied by an unknown conversion function and then set equal to the exposure rate at ground level. This equation is then solved for the conversion function by assuming as a solution a three-term polynomial. Conversion functions have been derived for various source distributions, including surface, uniform, and exponentially distributed sources. These conversion functions are independent of source energy, which means that a conversion can be made without any knowledge of the isotopic content of the source. In the case of a uniform distribution, these conversion functions provide conversions that agree to within 10% with ground truth measurements

  12. Consequences of the exposure at low dose rates-contribution of animal experimentation

    International Nuclear Information System (INIS)

    Masse, R.

    1990-01-01

    The exposure of laboratory animals to the various types of radiations will induce cancers in relation with the tissue absorbed doses. The shape of the dose-effet relationship is most variable. It is important to distinguish which tumours are comparable to human tumours. Those showing more analogies answer but seldom to the classical lineo-quadratic relationship; however, a strong attenuation of induction is demonstrated at low dose rates. Quasi-threshold relationships are seen after the exposure of some tissues to high-LET radiations. These observations question the validity of generalizing the radiobiologists' dual action theory, setting the origin of the dose-effect relationship in the induction of events within the DNA molecule. There is an alternative in the cellular collaboration events; it assumes that the effectiveness per dose unit decreases constantly as an inverse function of the dose rate [fr

  13. Influence of random daughter exposure rate, unattachment fraction, and disequilibrium on occurrence of lung tumors

    International Nuclear Information System (INIS)

    Cross, F.T.; Palmer, R.F.; Dagle, G.E.; Busch, R.H.; Buschbom, R.L.

    1983-10-01

    Groups of male, specific-pathogen-free (SPF), Wistar rats were exposed to several concentrations of radon daughters and uranium ore dust to clarify the roles of exposure rate, unattached RaA daughters, and the degree of radon daughter disequilibrium, in the development of respiratory system disease. Modeled, human-dosimetric data indicate that the dose to sensitive tissues of the respiratory tract increases with increasing radon-daughter unattachment fraction and degree of disequilibrium. Experimental verification of these dose-effect relationships is needed to protect the health of workers and of the public exposed to radon-daughter environments. Data bearing on these relationships as well as updated results of experiments designed to test the role of radon-daughter exposure rate on lung-tumor incidence are reported. 13 references, 3 tables

  14. Addressing the recovery of feeding rates in post-exposure feeding bioassays: Cyathura carinata as a case study

    Energy Technology Data Exchange (ETDEWEB)

    Pais-Costa, Antonia Juliana [IMAR—Institute of Marine Research, MARE—Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra (Portugal); Acevedo, Pelayo [SaBio IREC, Instituto de Investigación en Recursos Cinegéticos (UCLM-CSIC-JCCM), Ciudad Real 13005 (Spain); Marques, João Carlos [IMAR—Institute of Marine Research, MARE—Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra (Portugal); Martinez-Haro, Mónica, E-mail: monica.martinezharo@gmail.com [IMAR—Institute of Marine Research, MARE—Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra (Portugal)

    2015-02-15

    Post-exposure bioassays are used in environmental assessment as a cost-effective tool, but the effects of organism's recovery after exposure to pollutant has not yet been addressed in detail. The recoveries of post-exposure feeding rates after being exposed to two sublethal concentrations of cadmium during two different exposure periods (48 h and 96 h) were evaluated under laboratory conditions using the estuarine isopod Cyathura carinata. Results showed that feeding depression was a stable endpoint up to 24 h after cadmium exposure, which is useful for ecotoxicological bioassays. - Highlights: • We studied recovery of post-exposure feeding rates 48–96 h after cadmium exposure. • The assay is based on the isopod Cyathura carinata. • Post-exposure feeding inhibition is a stable sublethal endpoint.

  15. Exposure rate measurements on TV monitors LiF:Mg, Cu, P (GR- 200A) chips

    International Nuclear Information System (INIS)

    Sanaye, S.S.; Sadagopan, Geetha; Bhatt, B.C.

    2004-01-01

    For measuring exposure rate on black and white TV monitor screen, LiF:Mg,Cu,P (GR-200A) TLD chips were used. The samples were kept on TV monitor screen and exposed for 560 hrs with TV in 'ON' condition. The exposure rate on TV monitor screen was determined from integrated TL measurements and it varied from 0.081μGy/hr to 0.106 μGy/hr. Thus it was observed that the exposure levels were well below the prescribed limits (i.e. 5 μGy/h at 5 cm from the surface). LiF:Mg,Cu,P (GR-200A) TLD discs were also used to estimate the dose level on the surface of two types of TV monitors. The samples were kept at five different locations on the two (14 C PT AND 20 C PT) models of TV monitors and exposed for 622 hrs. From the measurement of TL, integrated dose on the screen were in the range 3.86 mR to 12.34 mR, the corresponding dose rate being 6.206 mR/hr to 19.839 mR/hr. This ensures that doses were well below the recommended limit of 0.5 mR/hr at 5cm. (author)

  16. n-Order and maximum fuzzy similarity entropy for discrimination of signals of different complexity: Application to fetal heart rate signals.

    Science.gov (United States)

    Zaylaa, Amira; Oudjemia, Souad; Charara, Jamal; Girault, Jean-Marc

    2015-09-01

    This paper presents two new concepts for discrimination of signals of different complexity. The first focused initially on solving the problem of setting entropy descriptors by varying the pattern size instead of the tolerance. This led to the search for the optimal pattern size that maximized the similarity entropy. The second paradigm was based on the n-order similarity entropy that encompasses the 1-order similarity entropy. To improve the statistical stability, n-order fuzzy similarity entropy was proposed. Fractional Brownian motion was simulated to validate the different methods proposed, and fetal heart rate signals were used to discriminate normal from abnormal fetuses. In all cases, it was found that it was possible to discriminate time series of different complexity such as fractional Brownian motion and fetal heart rate signals. The best levels of performance in terms of sensitivity (90%) and specificity (90%) were obtained with the n-order fuzzy similarity entropy. However, it was shown that the optimal pattern size and the maximum similarity measurement were related to intrinsic features of the time series. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Petroleum production at Maximum Efficient Rate Naval Petroleum Reserve No. 1 (Elk Hills), Kern County, California. Final Supplemental Environmental Impact Statement

    Energy Technology Data Exchange (ETDEWEB)

    1993-07-01

    This document provides an analysis of the potential impacts associated with the proposed action, which is continued operation of Naval Petroleum Reserve No. I (NPR-1) at the Maximum Efficient Rate (MER) as authorized by Public law 94-258, the Naval Petroleum Reserves Production Act of 1976 (Act). The document also provides a similar analysis of alternatives to the proposed action, which also involve continued operations, but under lower development scenarios and lower rates of production. NPR-1 is a large oil and gas field jointly owned and operated by the federal government and Chevron U.SA Inc. (CUSA) pursuant to a Unit Plan Contract that became effective in 1944; the government`s interest is approximately 78% and CUSA`s interest is approximately 22%. The government`s interest is under the jurisdiction of the United States Department of Energy (DOE). The facility is approximately 17,409 acres (74 square miles), and it is located in Kern County, California, about 25 miles southwest of Bakersfield and 100 miles north of Los Angeles in the south central portion of the state. The environmental analysis presented herein is a supplement to the NPR-1 Final Environmental Impact Statement of that was issued by DOE in 1979 (1979 EIS). As such, this document is a Supplemental Environmental Impact Statement (SEIS).

  18. Exposure to Fine Particulate Matter Leads to Rapid Heart Rate Variability Changes

    Directory of Open Access Journals (Sweden)

    Michael Riediker

    2018-01-01

    Full Text Available Introduction: Heart Rate Variability (HRV reflects the adaptability of the heart to internal and external stimuli. Reduced HRV is a predictor of post-infarction mortality. We previously found in road maintenance workers HRV-increases several hours after exposure to fine particulate matter (PM2.5. This seemed to conflict with studies where PM-exposure acutely reduced HRV. We therefore assessed whether time from exposure to HRV-assessment could explain the differences observed.Methods: On five non-consecutive days, workers carried nephelometers providing 1-min-interval PM2.5-exposure. Five-min HRV-intervals of SDNN (Standard Deviation of Normal to Normal beat intervals and pNN50 (Percentage of the interval differences exceeding 50 ms were extracted from 24-h electrocardiograms (ECGs. Following 60 min PM2.5-exposure, changes in HRV-parameters were assessed during 120-min visually and by regression analysis with control for time at work, at home, and during the night using autoregressive integrating moving average (ARIMA models to account for autocorrelation of the time-series. Additional controls included changing the time windows and including body mass index (BMI and age in the models.Result: Pattern analysis of 12,669 data points showed high modulation of mean, standard deviation (SD, and time trend of HRV (SDNN and pNN50 at low, and much reduced modulation at high PM2.5-exposures. The time trend following exposure was highly symmetrical, resembling a funnel plot. Regression analysis showed significant associations of decreasing SDNN and pNN50 (average, SD, and absolute value of time trend with increasing PM2.5-exposure, which remained significant when controlling for activity phases. Changing time windows did not change the pattern of response. Including BMI and age did not change the results.Conclusions: The reduced modulation of HRV following PM2.5-exposure is striking. It suggests strong interference with homeostatic controls. Such an

  19. Analysis of time series exposure rates obtained at a monitoring station around nuclear power stations

    International Nuclear Information System (INIS)

    Urabe, I.; Ogawa, Y.; Kimura, Y.; Honda, Y.; Nakashima, Y.; Yoshimoto, T.; Tsujimoto, T.

    1991-01-01

    From the investigation on the variation of AAD rates monitored in the natural environment around nuclear power station, it may be concluded; (1) Differences between monthly averaged air absorbed dose rates (AAD rates) given by all data obtained and those obtained in fine weather become larger in winter (from Dec. to Feb.) (2) Cummulative frequency distributions of AAD rates are very different among four seasons. Remarkably high AAD rates are observed by heavy rains in summer and snow falls or rains in winter. (3) Though the hypothesis that the frequency distribution of AAD rates fit to the lognormal distribution can not be accepted by chi-square test, higher part of the frequency distribution of AAD rates agree approximately with the lognormal one. (4) Identification of AAD rates due to plume exposure may be possible by statistical analysis assuming lognormal distribution of AAD rates as well as the discrimination method based on the reference standard using mean values and standard deviations of the data obtained in fine weather. (author)

  20. Interest Rate Demands and Television Viewing-Is a Single Exposure More Influential Than Routine Viewing?

    Science.gov (United States)

    Hetsroni, Amir; Reizer, Abira; Ben Zion, Uri

    2017-04-01

    This study examined the impact of media consumption, and particularly exposure to television, on decisions regarding interest rate demands. One hundred and fifty-four participants were randomly divided into two groups: in the manipulation group, participants were exposed to a news clip about an Iranian nuclear attack on Israel, whereas in the control group, the participants were not exposed to the film. Both groups filled a questionnaires regarding their interest rate requirements in different situations, their media conception behaviors, and demographic questionnaires. Frequent routine viewing increased the interest rate demands only among participants in the manipulation group, but the manipulation itself did not have a significant effect on interest rate demands. The results are explained in terms of cultivation theory.

  1. Impact of heart rate and rhythm on radiation exposure in prospectively ECG triggered computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Luecke, Christian, E-mail: neep@gmx.de [University of Leipzig – Heart Center, Department of Diagnostic and Interventional Radiology, Strümpellstrasse 39, D-04289, Leipzig (Germany); Andres, Claudia; Foldyna, Borek [University of Leipzig – Heart Center, Department of Diagnostic and Interventional Radiology, Strümpellstrasse 39, D-04289, Leipzig (Germany); Nagel, Hans Dieter [Wissenschaft and Technik für die Radiologie, Buchhholz i.d.N (Germany); Hoffmann, Janine; Grothoff, Matthias; Nitzsche, Stefan; Gutberlet, Matthias; Lehmkuhl, Lukas [University of Leipzig – Heart Center, Department of Diagnostic and Interventional Radiology, Strümpellstrasse 39, D-04289, Leipzig (Germany)

    2012-09-15

    Purpose: To evaluate the influence of different heart rates and arrhythmias on scanner performance, image acquisition and applied radiation exposure in prospectively ECG triggered computed tomography (pCT). Materials and methods: An ECG simulator (EKG Phantom 320, Müller and Sebastiani Elektronik GmbH, Munich, Germany) was used to generate different heart rhythms and arrhythmias: sinus rhythm (SR) at 45, 60, 75, 90 and 120/min, supraventricular arrhythmias (e.g. sinus arrhythmia, atrial fibrillation) and ventricular arrhythmias (e.g. ventricular extrasystoles), pacemaker-ECGs, ST-changes and technical artifacts. The analysis of the image acquisition process was performed on a 64-row multidetector CT (Brilliance, Philips Medical Systems, Cleveland, USA). A prospectively triggered scan protocol as used for routine was applied (120 kV; 150 mA s; 0.4 s rotation and exposure time per scan; image acquisition predominantly in end-diastole at 75% R-R-interval, in arrythmias with a mean heart rate above 80/min in systole at 45% of the R-R-interval; FOV 25 cm). The mean dose length product (DLP) and its percentage increase from baseline (SR at 60/min) were determined. Result: Radiation exposure can increase significantly when the heart rhythm deviates from sinus rhythm. ECG-changes leading to a significant DLP increase (p < 0.05) were bifocal pacemaker (61%), pacemaker dysfunction (22%), SVES (20%), ventricular salvo (20%), and atrial fibrillation (14%). Significantly (p < 0.05) prolonged scan time (>8 s) could be observed in bifocal pacemaker (12.8 s), pacemaker dysfunction (10.7 s), atrial fibrillation (10.3 s) and sinus arrhythmia (9.3 s). Conclusion: In prospectively ECG triggered CT, heart rate and rhythm can provoke different types of scanner performance, which can significantly alter radiation exposure and scan time. These results might have an important implication for indication, informed consent and contrast agent injection protocols.

  2. Impact of heart rate and rhythm on radiation exposure in prospectively ECG triggered computed tomography

    International Nuclear Information System (INIS)

    Luecke, Christian; Andres, Claudia; Foldyna, Borek; Nagel, Hans Dieter; Hoffmann, Janine; Grothoff, Matthias; Nitzsche, Stefan; Gutberlet, Matthias; Lehmkuhl, Lukas

    2012-01-01

    Purpose: To evaluate the influence of different heart rates and arrhythmias on scanner performance, image acquisition and applied radiation exposure in prospectively ECG triggered computed tomography (pCT). Materials and methods: An ECG simulator (EKG Phantom 320, Müller and Sebastiani Elektronik GmbH, Munich, Germany) was used to generate different heart rhythms and arrhythmias: sinus rhythm (SR) at 45, 60, 75, 90 and 120/min, supraventricular arrhythmias (e.g. sinus arrhythmia, atrial fibrillation) and ventricular arrhythmias (e.g. ventricular extrasystoles), pacemaker-ECGs, ST-changes and technical artifacts. The analysis of the image acquisition process was performed on a 64-row multidetector CT (Brilliance, Philips Medical Systems, Cleveland, USA). A prospectively triggered scan protocol as used for routine was applied (120 kV; 150 mA s; 0.4 s rotation and exposure time per scan; image acquisition predominantly in end-diastole at 75% R-R-interval, in arrythmias with a mean heart rate above 80/min in systole at 45% of the R-R-interval; FOV 25 cm). The mean dose length product (DLP) and its percentage increase from baseline (SR at 60/min) were determined. Result: Radiation exposure can increase significantly when the heart rhythm deviates from sinus rhythm. ECG-changes leading to a significant DLP increase (p 8 s) could be observed in bifocal pacemaker (12.8 s), pacemaker dysfunction (10.7 s), atrial fibrillation (10.3 s) and sinus arrhythmia (9.3 s). Conclusion: In prospectively ECG triggered CT, heart rate and rhythm can provoke different types of scanner performance, which can significantly alter radiation exposure and scan time. These results might have an important implication for indication, informed consent and contrast agent injection protocols

  3. Suicide Rates and State Laws Regulating Access and Exposure to Handguns.

    Science.gov (United States)

    Anestis, Michael D; Anestis, Joye C

    2015-10-01

    Using previous research, we examined the impact of 4 handgun laws (waiting periods, universal background checks, gun locks, and open carrying regulations) on suicide rates. We used publicly available databases to collect information on statewide laws, suicide rates, and demographic characteristics for 2013. Each law was associated with significantly lower firearm suicide rates and the proportion of suicides resulting from firearms. In addition, each law, except for that which required a waiting period, was associated with a lower overall suicide rate. Follow-up analyses showed a significant indirect effect on overall suicide rates through the proportion of suicides by firearms, indicating that the reduced overall suicide rate was attributable to fewer suicide attempts, fewer handguns in the home, suicide attempts using less lethal means, or a combination of these factors. States that implemented any of these laws saw a decreased suicide rate in subsequent years, whereas the only state that repealed 1 of these laws saw an increased suicide rate. Our results were supportive of a potentially vital role in suicide prevention for state legislation that limits access and exposure to handguns.

  4. Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems.

    Science.gov (United States)

    Blok, Chris; Jackson, Brian E; Guo, Xianfeng; de Visser, Pieter H B; Marcelis, Leo F M

    2017-01-01

    Growing on rooting media other than soils in situ -i.e., substrate-based growing- allows for higher yields than soil-based growing as transport rates of water, nutrients, and oxygen in substrate surpass those in soil. Possibly water-based growing allows for even higher yields as transport rates of water and nutrients in water surpass those in substrate, even though the transport of oxygen may be more complex. Transport rates can only limit growth when they are below a rate corresponding to maximum plant uptake. Our first objective was to compare Chrysanthemum growth performance for three water-based growing systems with different irrigation. We compared; multi-point irrigation into a pond (DeepFlow); one-point irrigation resulting in a thin film of running water (NutrientFlow) and multi-point irrigation as droplets through air (Aeroponic). Second objective was to compare press pots as propagation medium with nutrient solution as propagation medium. The comparison included DeepFlow water-rooted cuttings with either the stem 1 cm into the nutrient solution or with the stem 1 cm above the nutrient solution. Measurements included fresh weight, dry weight, length, water supply, nutrient supply, and oxygen levels. To account for differences in radiation sum received, crop performance was evaluated with Radiation Use Efficiency (RUE) expressed as dry weight over sum of Photosynthetically Active Radiation. The reference, DeepFlow with substrate-based propagation, showed the highest RUE, even while the oxygen supply provided by irrigation was potentially growth limiting. DeepFlow with water-based propagation showed 15-17% lower RUEs than the reference. NutrientFlow showed 8% lower RUE than the reference, in combination with potentially limiting irrigation supply of nutrients and oxygen. Aeroponic showed RUE levels similar to the reference and Aeroponic had non-limiting irrigation supply of water, nutrients, and oxygen. Water-based propagation affected the subsequent

  5. Exposure to Discrimination and Heart Rate Variability Reactivity to Acute Stress among Women with Diabetes.

    Science.gov (United States)

    Wagner, Julie; Lampert, Rachel; Tennen, Howard; Feinn, Richard

    2015-08-01

    Exposure to racial discrimination has been linked to physiological reactivity. This study investigated self-reported exposure to racial discrimination and parasympathetic [high-frequency heart rate variability (HF-HRV)] and sympathetic (norepinephrine and cortisol) activity at baseline and then again after acute laboratory stress. Lifetime exposure to racial discrimination was measured with the Schedule of Racist Events scale. Thirty-two women (16 Black and 16 White) with type 2 diabetes performed a public speaking stressor. Beat-to-beat intervals were recorded on electrocardiograph recorders, and HF-HRV was calculated using spectral analysis and natural log transformed. Norepinephrine and cortisol were measured in blood. Higher discrimination predicted lower stressor HF-HRV, even after controlling for baseline HF-HRV. When race, age, A1c and baseline systolic blood pressure were also controlled, racial discrimination remained a significant independent predictor of stressor HF-HRV. There was no association between lifetime discrimination and sympathetic markers. In conclusion, preliminary data suggest that among women with type 2 diabetes mellitus (T2DM), exposure to racial discrimination is adversely associated with parasympathetic, but not sympathetic, reactivity. Copyright © 2013 John Wiley & Sons, Ltd.

  6. Does chronic occupational exposure to volatile anesthetic agents influence the rate of neutrophil apoptosis?

    LENUS (Irish Health Repository)

    Goto, Y

    2012-02-03

    PURPOSE: The purpose of this preliminary investigation was to determine whether the rate of neutrophil apoptosis in health care workers is influenced by exposure to volatile anesthetic agents. METHODS: Percentage neutrophil apoptosis (Annexin-V FITC assay) was measured in health care workers (n = 20) and unexposed volunteers (n = 10). For the health care workers, time weighted personal exposure monitoring to N2O, sevoflurane and isoflurane was carried out. RESULTS: The sevoflurane and isoflurane concentrations to which health care workers were exposed were less than recommended levels in all 20 cases. Percent apoptosis was less at 24 (but not at one and 12) hr culture in health care workers [50.5 (9.7)%; P = 0.008] than in unexposed volunteers [57.3 (5.1)%]. CONCLUSION: Inhibition of neutrophil apoptosis at 24 hr culture was demonstrated in health care workers chronically exposed to volatile anesthetic agents. Exposure was well below recommended levels in the both scavenged and unscavenged work areas in which the study was carried out. Further study is required to assess the effect of greater degrees of chronic exposure to volatile anesthetic agents on neutrophil apoptosis.

  7. GAS SURFACE DENSITY, STAR FORMATION RATE SURFACE DENSITY, AND THE MAXIMUM MASS OF YOUNG STAR CLUSTERS IN A DISK GALAXY. II. THE GRAND-DESIGN GALAXY M51

    International Nuclear Information System (INIS)

    González-Lópezlira, Rosa A.; Pflamm-Altenburg, Jan; Kroupa, Pavel

    2013-01-01

    We analyze the relationship between maximum cluster mass and surface densities of total gas (Σ gas ), molecular gas (Σ H 2 ), neutral gas (Σ H I ), and star formation rate (Σ SFR ) in the grand-design galaxy M51, using published gas data and a catalog of masses, ages, and reddenings of more than 1800 star clusters in its disk, of which 223 are above the cluster mass distribution function completeness limit. By comparing the two-dimensional distribution of cluster masses and gas surface densities, we find for clusters older than 25 Myr that M 3rd ∝Σ H I 0.4±0.2 , whereM 3rd is the median of the five most massive clusters. There is no correlation withΣ gas ,Σ H2 , orΣ SFR . For clusters younger than 10 Myr, M 3rd ∝Σ H I 0.6±0.1 and M 3rd ∝Σ gas 0.5±0.2 ; there is no correlation with either Σ H 2 orΣ SFR . The results could hardly be more different from those found for clusters younger than 25 Myr in M33. For the flocculent galaxy M33, there is no correlation between maximum cluster mass and neutral gas, but we have determined M 3rd ∝Σ gas 3.8±0.3 , M 3rd ∝Σ H 2 1.2±0.1 , and M 3rd ∝Σ SFR 0.9±0.1 . For the older sample in M51, the lack of tight correlations is probably due to the combination of strong azimuthal variations in the surface densities of gas and star formation rate, and the cluster ages. These two facts mean that neither the azimuthal average of the surface densities at a given radius nor the surface densities at the present-day location of a stellar cluster represent the true surface densities at the place and time of cluster formation. In the case of the younger sample, even if the clusters have not yet traveled too far from their birth sites, the poor resolution of the radio data compared to the physical sizes of the clusters results in measuredΣ that are likely quite diluted compared to the actual densities relevant for the formation of the clusters.

  8. SAROTA: application of specific absorption rate (SAR) and over-the-air (OTA) data for the characterization of the real-life exposure due to mobile phones

    International Nuclear Information System (INIS)

    Monebhurrun, Vikass

    2013-01-01

    The RF exposure level of a mobile phone is quantified by the measurement of the specific absorption rate (SAR) under laboratory conditions. The SAR which is measured while the mobile phone is operated at maximum power level does not reflect the real-life exposure scenario since the mobile phone typically re-adjusts its power level and frequency depending on the quality of the communication link with the nearest base station. The choice of a low RF exposure device based on the comparison of the relative SAR values of mobile phones can be misleading. The real-life RF exposure also depends on the over-the-air (OTA) performance of the mobile phone. Taken independently, the two sets of data do not allow a straightforward comparison of the global RF performance amongst mobile phones. A unique and simple parameter denoted as the SAROTA index is proposed for the characterization of mobile phones with regard to both RF exposure and OTA performance. The SAROTA index provides the real-life exposure index of the mobile phone.

  9. Influence of radiation exposure rate on somatic mutation frequency and loss of reproductive integrity in tradescantia stamen hairs

    International Nuclear Information System (INIS)

    Ichikawa, S.; Nauman, C.H.; Sparrow, A.H.; Takahashi, C.S.

    1978-01-01

    Inflorescences of Tradescantia clone 02 (2n=12), hetero- or hemi-zygous for flower color, were exposed to a series of γ-ray exposures at two different exposure rates, 29.3 R/min and 0.026-0.52 R/min. Pink mutation-response curves, and survival curves based on reproductive integrity, were constructed for each of the exposure rates. Loss of reproductive integrity was also assessed at high (256 R/min) and low (0.52-4.17 R/min) γ-ray exposure rates in T. blossfeldiana (2n=72). All observations were made on stamen hairs. The higher exposure rate was 1.3-1.7 times more effective in inducing pink mutations in clone 02. A greater efficiency of the higher exposure rate was also found for both taxa at the loss of reproductive integrity endpoint. The D 0 values obtained at the higher exposure rates, 154 R for clone 02 and 720 R for T. blossfeldiana, were significantly lower than the corresponding values of 270 R and 1880 R obtained at the lower exposure rates. These D 0 's differ by factors of 1.75 and 2.61 for clone 02 and T. blossfeldiana, respectively. D 0 's for the two taxa were found to be inversely correlated with their interphase chromosome volumes. (Auth.)

  10. Dose-rate models for human survival after exposure to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jones, T.D.; Morris, M.D.; Young, R.W.

    1986-01-01

    This paper reviews new estimates of the L/sub 50/ in man by Mole and by Rotblat, the biological processes contributing to hematologic death, the collection of animal experiments dealing with hematologic death, and the use of regression analysis to make new estimates of human mortality based on all relevant animal studies. Regression analysis of animal mortality data has shown that mortality is dependent strongly on dose rate, species, body weight, and time interval over which the exposure is delivered. The model has predicted human LD/sub 50/s of 194, 250, 310, and 360 rad to marrow when the exposure time is a minute, an hour, a day, and a week, respectively.

  11. Fragile-to-fragile liquid transition at Tg and stable-glass phase nucleation rate maximum at the Kauzmann temperature TK

    International Nuclear Information System (INIS)

    Tournier, Robert F.

    2014-01-01

    An undercooled liquid is unstable. The driving force of the glass transition at T g is a change of the undercooled-liquid Gibbs free energy. The classical Gibbs free energy change for a crystal formation is completed including an enthalpy saving. The crystal growth critical nucleus is used as a probe to observe the Laplace pressure change Δp accompanying the enthalpy change −V m ×Δp at T g where V m is the molar volume. A stable glass–liquid transition model predicts the specific heat jump of fragile liquids at T≤T g , the Kauzmann temperature T K where the liquid entropy excess with regard to crystal goes to zero, the equilibrium enthalpy between T K and T g , the maximum nucleation rate at T K of superclusters containing magic atom numbers, and the equilibrium latent heats at T g and T K . Strong-to-fragile and strong-to-strong liquid transitions at T g are also described and all their thermodynamic parameters are determined from their specific heat jumps. The existence of fragile liquids quenched in the amorphous state, which do not undergo liquid–liquid transition during heating preceding their crystallization, is predicted. Long ageing times leading to the formation at T K of a stable glass composed of superclusters containing up to 147 atom, touching and interpenetrating, are evaluated from nucleation rates. A fragile-to-fragile liquid transition occurs at T g without stable-glass formation while a strong glass is stable after transition

  12. Organ and effective dose rate coefficients for submersion exposure in occupational settings

    International Nuclear Information System (INIS)

    Veinot, K.G.; Dewji, S.A.; Hiller, M.M.; Eckerman, K.F.; Easterly, C.E.

    2017-01-01

    External dose coefficients for environmental exposure scenarios are often computed using assumption on infinite or semi-infinite radiation sources. For example, in the case of a person standing on contaminated ground, the source is assumed to be distributed at a given depth (or between various depths) and extending outwards to an essentially infinite distance. In the case of exposure to contaminated air, the person is modeled as standing within a cloud of infinite, or semi-infinite, source distribution. However, these scenarios do not mimic common workplace environments where scatter off walls and ceilings may significantly alter the energy spectrum and dose coefficients. In this paper, dose rate coefficients were calculated using the International Commission on Radiological Protection (ICRP) reference voxel phantoms positioned in rooms of three sizes representing an office, laboratory, and warehouse. For each room size calculations using the reference phantoms were performed for photons, electrons, and positrons as the source particles to derive mono-energetic dose rate coefficients. Since the voxel phantoms lack the resolution to perform dose calculations at the sensitive depth for the skin, a mathematical phantom was developed and calculations were performed in each room size with the three source particle types. Coefficients for the noble gas radionuclides of ICRP Publication 107 (e.g., Ne, Ar, Kr, Xe, and Rn) were generated by folding the corresponding photon, electron, and positron emissions over the mono-energetic dose rate coefficients. Results indicate that the smaller room sizes have a significant impact on the dose rate per unit air concentration compared to the semi-infinite cloud case. For example, for Kr-85 the warehouse dose rate coefficient is 7% higher than the office dose rate coefficient while it is 71% higher for Xe-133. (orig.)

  13. Organ and effective dose rate coefficients for submersion exposure in occupational settings

    Energy Technology Data Exchange (ETDEWEB)

    Veinot, K.G. [Easterly Scientific, Knoxville, TN (United States); Y-12 National Security Complex, Oak Ridge, TN (United States); Dewji, S.A.; Hiller, M.M. [Center for Radiation Protection Knowledge, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Eckerman, K.F.; Easterly, C.E. [Easterly Scientific, Knoxville, TN (United States)

    2017-11-15

    External dose coefficients for environmental exposure scenarios are often computed using assumption on infinite or semi-infinite radiation sources. For example, in the case of a person standing on contaminated ground, the source is assumed to be distributed at a given depth (or between various depths) and extending outwards to an essentially infinite distance. In the case of exposure to contaminated air, the person is modeled as standing within a cloud of infinite, or semi-infinite, source distribution. However, these scenarios do not mimic common workplace environments where scatter off walls and ceilings may significantly alter the energy spectrum and dose coefficients. In this paper, dose rate coefficients were calculated using the International Commission on Radiological Protection (ICRP) reference voxel phantoms positioned in rooms of three sizes representing an office, laboratory, and warehouse. For each room size calculations using the reference phantoms were performed for photons, electrons, and positrons as the source particles to derive mono-energetic dose rate coefficients. Since the voxel phantoms lack the resolution to perform dose calculations at the sensitive depth for the skin, a mathematical phantom was developed and calculations were performed in each room size with the three source particle types. Coefficients for the noble gas radionuclides of ICRP Publication 107 (e.g., Ne, Ar, Kr, Xe, and Rn) were generated by folding the corresponding photon, electron, and positron emissions over the mono-energetic dose rate coefficients. Results indicate that the smaller room sizes have a significant impact on the dose rate per unit air concentration compared to the semi-infinite cloud case. For example, for Kr-85 the warehouse dose rate coefficient is 7% higher than the office dose rate coefficient while it is 71% higher for Xe-133. (orig.)

  14. Upper arm elevation and repetitive shoulder movements: a general population job exposure matrix based on expert ratings and technical measurements.

    Science.gov (United States)

    Dalbøge, Annett; Hansson, Gert-Åke; Frost, Poul; Andersen, Johan Hviid; Heilskov-Hansen, Thomas; Svendsen, Susanne Wulff

    2016-08-01

    We recently constructed a general population job exposure matrix (JEM), The Shoulder JEM, based on expert ratings. The overall aim of this study was to convert expert-rated job exposures for upper arm elevation and repetitive shoulder movements to measurement scales. The Shoulder JEM covers all Danish occupational titles, divided into 172 job groups. For 36 of these job groups, we obtained technical measurements (inclinometry) of upper arm elevation and repetitive shoulder movements. To validate the expert-rated job exposures against the measured job exposures, we used Spearman rank correlations and the explained variance[Formula: see text] according to linear regression analyses (36 job groups). We used the linear regression equations to convert the expert-rated job exposures for all 172 job groups into predicted measured job exposures. Bland-Altman analyses were used to assess the agreement between the predicted and measured job exposures. The Spearman rank correlations were 0.63 for upper arm elevation and 0.64 for repetitive shoulder movements. The expert-rated job exposures explained 64% and 41% of the variance of the measured job exposures, respectively. The corresponding calibration equations were y=0.5%time+0.16×expert rating and y=27°/s+0.47×expert rating. The mean differences between predicted and measured job exposures were zero due to calibration; the 95% limits of agreement were ±2.9% time for upper arm elevation >90° and ±33°/s for repetitive shoulder movements. The updated Shoulder JEM can be used to present exposure-response relationships on measurement scales. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  15. Effects of chronic occupational exposure to anaesthetic gases on the rate of neutrophil apoptosis among anaesthetists.

    LENUS (Irish Health Repository)

    Tyther, R

    2012-02-03

    BACKGROUND AND OBJECTIVE: Volatile anaesthetic agents are known to influence neutrophil function. The aim was to determine the effect of chronic occupational exposure to volatile anaesthetic agents on the rate of neutrophil apoptosis among anaesthetists. To test this hypothesis, we compared the rate of neutrophil apoptosis in anaesthetists who had been chronically exposed to volatile anaesthetic agents with that in unexposed volunteers. METHODS: Venous blood (20 mL) was withdrawn from 24 ASA I-II volunteers, from which neutrophils were isolated, and maintained in culture. At 1, 12 and 24 h in culture, the percentage of neutrophil apoptosis was assessed by dual staining with annexin V-FITC and propidium iodide. RESULTS: At 1 h (but not at 12 and 24 h) in culture, the rate of neutrophil apoptosis was significantly less in the anaesthetists--13.8 (12.9%) versus 34.4 (12.1%) (P = 0.001). CONCLUSIONS: Chronic occupational exposure to volatile anaesthetic agents may inhibit neutrophil apoptosis. This may have implications for anaesthetists and similarly exposed healthcare workers in terms of the adequacy of their inflammatory response.

  16. Set of programs for determining exposure and dose rates from selected sources of gamma radiation

    International Nuclear Information System (INIS)

    Hep, J.; Kralovcova, E.; Smutny, V.; Valenta, V.

    1982-01-01

    The programs are described for the determination of exposure and dose rate of gamma radiation from point, surface, linear and volume sources with and without shielding. The computation is conducted using the classical method taking into consideration the buildup factor. For the computation of the buildup factor in heterogeneous shielding the Broder and Kitazuma formulas are used. Kitazuma's alpha coefficients were calculated recurrently using a new semi-empirical method. Taylor's approximation was used for the calculation of the buildup factor in a single layer

  17. Determination of correction and conversion factor of exposure rate generated Gamma spectrometer GR-320 to Victoreen data

    International Nuclear Information System (INIS)

    Supardjo-AS; Mappa, Djody-Rachim; Nasrun-Syamsul; Syamsul-Hadi

    2000-01-01

    Exposure rate data of Muria Peninsula were generated from Victoreen-491 measurement and calculation of radioelement content in soil which were measured by Exploranium GR-320, using IAEA formula. However those data are not be comparable so the exposure rate calculated from Gamma Spectrometer data necessarily to be corrected. The correction factor was determinate by measuring the exposure rate of at the NMDC's back yard selected location using Victoreen-491 and Gamma Spectrometer Exploranium GR-320 . Correction factor was created by comparing mean exposure rate data that calculated from 30 data measured by Gamma Spectrometer instrument and to those Victoreen's exposure rate. Conversion factor was gained from comparing of total count data of Gamma Spectrometer Exploranium GR-320 to Victoreen's exposure rate data. The correction factor of Exploranium GR-320's exposure rate is 0.34 μR/hours, and the conversion factor of total count is 0.0092 μR/hours per c/m. Deviation Victoreen 491 = 4.7 % and Gamma Spectrometer Exploranium GR-320 8.6 %

  18. Effect of dose rate and exposure time on the stimulation effect of tube growth of Pinus sylvestris pollen

    International Nuclear Information System (INIS)

    Zelles, L.; Fendrik, I.; Technische Univ. Hannover

    1975-01-01

    The stimulating effect of ionizing radiation in respect to dose rate and exposure time was studied using the tube growth of Pinus silvestris pollen. Stimulation was registered with a small dose (50 rad) supplied at low dose rates (0.5; 1.0; 3.0 and 5.0 rad/sec) and with higher doses (300; 800 and 1,400 rad) supplied at higher dose rates (10; 40 and 50 rad/sec). This suggests that only the exposure time is of importance for radiation-induced stimulation provided that the exposure time does not exceed 100 sec. (orig.) [de

  19. Investigation of exposure rates and radionuclide and trace metal distributions along the Hanford Reach of the Columbia River

    International Nuclear Information System (INIS)

    Cooper, A.T.; Woodruff, R.K.

    1993-09-01

    Studies have been conducted to investigate exposure rates, and radionuclide and trace metal distributions along the Columbia River where it borders the Hanford Site. The last major field study was conducted in 1979. With recently renewed interest in various land use and resource protection alternatives, it is important to have data that represent current conditions. Radionuclides and trace metals were surveyed in Columbia River shoreline soils along the Hanford Site (Hanford Reach). The work was conducted as part of the Surface Environmental Surveillance Project, Pacific Northwest Laboratory. The survey consisted of taking exposure rate measurements and soil samples primarily at locations known or expected to have elevated exposure rates

  20. Bacterial Community Dynamics and Biodegradation Rates in Untreated and Oily Soils During PAH Exposure

    International Nuclear Information System (INIS)

    Zakaria, A.E.M.

    2008-01-01

    The approach taken in this study represents an attempt to address the possible selective effects of Polycyclic aromatic hydrocarbons (PAH) on the bacterial community structure of an untreated garden soil (S) and a chronically contaminated oily soil (CS). Untreated and chronically hydrocarbon polluted soils, collected from Egypt were enriched in shaking flasks containing 50 mg/l anthracene as a sole source of carbon over a period of 15 days. Bacterial communities in each soil were profiled by denaturing gradient gel electrophoresis (DGGE) analysis of the PCR amplified 16 S r DNA gene fragments after 0, 5, 10, and 15 days. Culture able biodegrading bacterial counts on minerals- Silica gel- Oil (MSD) plates as well as anthracene degradation for both soils were followed up at the same time intervals. Nine bacterial species were found to be dominant in the pristine soil before enrichment with the model polycyclic aromatic hydrocarbon (PAH), eight of them disappeared after live days of enrichment with the domination of one new species. It stayed dominant in soil until 15 days - exposure to anthracene. Therefore it can be used as a bio marker for PAH pollution. The chronically contaminated soil revealed a remarkable increase in the diversity directly after 5 days exposure to PAH HPLC analysis of the extracted anthracene remained in the biodegradation flasks after different degradation periods revealed that a higher biodegradation rates were accomplished by the oily soil consortium rather than by the pristine one. Before exposure to PAH, counts of culture able biodegrading bacteria were found to be higher in the untreated soil rather than in the oily one. After exposure the situation has been a bit altered as the counts in the untreated soil revealed a temporary suppression with a prolongation of the time required for growth as a result of the hydrocarbon stress

  1. Exchange Rate Exposure Management: An Empirical Study into the Strategies of Industrial Companies

    DEFF Research Database (Denmark)

    Aabo, Tom

    1999-01-01

    that major reasons behind this focus are the dynamic development of the competitive environment and the ability of the specific company to counter unfavorable changes in exchange rates by the exercise of real options (e.g. reallocation of production resources). As such, the study shows the in adequacy......This cross-case study of eight blue-chip industrial companies extends previous studies of why exchange rate exposure management is done the way it is. While hedging should not be pursued unless it creates value, the operational objectives differ among companies. Avoiding financial distress...... is considered one of the most important ways of adding value by hedging. However, reducing stakeholders perceived risk and improving the ability to pursue investment plans and make value adding investments do also get some attention. While the overall objective is to add value, the dominating object...

  2. Modelling radiation exposure in homes from siporex blocks by using exhalation rates of radon

    Directory of Open Access Journals (Sweden)

    Nikolić Mladen D.

    2015-01-01

    Full Text Available Building materials are the second major source of indoor radon, after soil. The contribution of building materials to indoor radon amount depends upon the radium content and exhalation rates, which can be used as a primary index for radon levels in the dwellings. This paper presents the results of using the experimentally determined exhalation rates of siporex blocks and concrete plates, to assess the radiation exposure in dwellings built of siporex blocks. The annual doses in rooms have been estimated depending on the established modes of ventilation. Realistic scenario was created to predict an annual effective dose for an old person, a housewife, a student, and an employed tenant, who live in the same apartment, spending different periods of time in it. The results indicate the crucial importance of good ventilation of the living space.

  3. Regional Inversion of the Maximum Carboxylation Rate (Vcmax) through the Sunlit Light Use Efficiency Estimated Using the Corrected Photochemical Reflectance Ratio Derived from MODIS Data

    Science.gov (United States)

    Zheng, T.; Chen, J. M.

    2016-12-01

    The maximum carboxylation rate (Vcmax), despite its importance in terrestrial carbon cycle modelling, remains challenging to obtain for large scales. In this study, an attempt has been made to invert the Vcmax using the gross primary productivity from sunlit leaves (GPPsun) with the physiological basis that the photosynthesis rate for leaves exposed to high solar radiation is mainly determined by the Vcmax. Since the GPPsun can be calculated through the sunlit light use efficiency (ɛsun), the main focus becomes the acquisition of ɛsun. Previous studies using site level reflectance observations have shown the ability of the photochemical reflectance ratio (PRR, defined as the ratio between the reflectance from an effective band centered around 531nm and a reference band) in tracking the variation of ɛsun for an evergreen coniferous stand and a deciduous broadleaf stand separately and the potential of a NDVI corrected PRR (NPRR, defined as the product of NDVI and PRR) in producing a general expression to describe the NPRR-ɛsun relationship across different plant function types. In this study, a significant correlation (R2 = 0.67, p<0.001) between the MODIS derived NPRR and the site level ɛsun calculated using flux data for four Canadian flux sites has been found for the year 2010. For validation purpose, the ɛsun in 2009 for the same sites are calculated using the MODIS NPRR and the expression from 2010. The MODIS derived ɛsun matches well with the flux calculated ɛsun (R2 = 0.57, p<0.001). Same expression has then been applied over a 217 × 193 km area in Saskatchewan, Canada to obtain the ɛsun and thus GPPsun for the region during the growing season in 2008 (day 150 to day 260). The Vcmax for the region is inverted using the GPPsun and the result is validated at three flux sites inside the area. The results show that the approach is able to obtain good estimations of Vcmax values with R2 = 0.68 and RMSE = 8.8 μmol m-2 s-1.

  4. Comparison of gamma-ray exposure rate measurements at Bikini Atoll

    International Nuclear Information System (INIS)

    Gudiksen, P.H.; Crites, T.R.

    1975-01-01

    A radiological survey of Bikini and Eneu Islands of the Bikini Atoll was conducted during June 1975 to assess the potential radiation doses that may be received by the returning Bikinians. Bikini Atoll was one of the U.S. nuclear weapons testing sites in the Pacific. An integral part of the survey included measurements of the gamma-ray exposure rates at 1 m above the ground with portable NaI instruments at nearly 2700 locations on the two islands. For comparison purposes, similar measurements were made with a pressurized ion chamber at approximately 200 locations, and with LiF and CaF 2 :Dy thermoluminescent dosimeters (TLDs) at 80 locations. The results indicate that the NaI scintillators overresponded because of their nonlinear energy characteristics. The responses of the LiF dosimeters and the pressurized ion chamber agreed to within 13 percent. Attenuation studies with LiF TLDs indicated that roughly 25 percent of the total free air exposure rate at 1 m was due to beta radiation

  5. External exposure rates from terrestrial radiation at Guarapari and Meaipe in Brazil

    International Nuclear Information System (INIS)

    Fujinami, N.; Koga, T.; Morishima, H.

    2000-01-01

    Recently epidemiological and cytogenetic studies on inhabitants living in high background radiation areas have been carried out in order to examine health effects of exposure to low dose radiation. Guarapari and Meaipe are towns built on the monazite sand region along the Atlantic coast in Brazil, which is one of the widely known high background radiation areas in the world. As an initial step toward studies on health effects of high background radiation on inhabitants living in Guarapari and Meaipe, we surveyed absorbed dose rates in air in these towns with a portable NaI(Tl) scintillation detector in September 1998. Sand and soil were also sampled there so as to determine the concentrations of Th-232 and Ra-226 in them. In Guarapari and Meaipe, dose rates in the streets ranged from 0.1 to 0.4 μ Gy/h except for a few places such as near the Areia Preta beach and Meaipe beach. Dose rates inside houses were lower than 0.2 μ Gy/h except that two houses attained a dose rate of 0.4 μ Gy/h. Our effective dose rate from external terrestrial irradiation (outdoors and indoors) was 0.17 μ Sv/h on the average, during the period of our three day stay in Guarapari and Meaipe. From comparison of our present values with those observed in the 1960s, which were cited in UNSCEAR reports, it is indicated that dose rate levels have decreased clearly in downtown, while the levels have scarcely changed in beaches and unpaved beach streets which have not been developed yet. This fact suggests that the natural radiation environment of Guarapari and Meaipe has varied with urbanization which brought paved streets, and changes in the structure and building materials of houses. A detailed survey is necessary in order to evaluate present absorbed dose rates in air in this area. (author)

  6. Acute myeloid leukemia induction in CBA/H mice by irradiation with fission neutrons as a function of exposure rate

    International Nuclear Information System (INIS)

    Huiskamp, R.

    1991-01-01

    Radiation-induced acute myeloid leukemia (AML) in male CBA/H mice was used as a model for investigation of the effect of reduced fast fission neutron exposure rates on radiation-induced carcinogenesis. Groups of about 90 male CBA/H mice were irradiated or sham-irradiated at the age of 15-20 weeks. The animals were exposed to 400 mGy fast fission neutrons at exposure rates of 2, 10 or 100 mGy/min. The investigation clearly showed that reducing the exposure rate of high-LET fast fission neutrons had no influence on the incidence of AML or on the survival of the irradiated mice. In contrast, a higher incidence of lymphosarcomas was observed in mice irradiated with higher exposure rates. (orig./MG)

  7. Acute myeloid leukemia induction in CBA/H mice by irradiation with fission neutrons as a function of exposure rate

    Energy Technology Data Exchange (ETDEWEB)

    Huiskamp, R [Stichting Energieonderzoek Centrum Nederland, Petten (Netherlands). Radiobiology and Radio-Ecology Unit

    1991-06-01

    Radiation-induced acute myeloid leukemia (AML) in male CBA/H mice was used as a model for investigation of the effect of reduced fast fission neutron exposure rates on radiation-induced carcinogenesis. Groups of about 90 male CBA/H mice were irradiated or sham-irradiated at the age of 15-20 weeks. The animals were exposed to 400 mGy fast fission neutrons at exposure rates of 2, 10 or 100 mGy/min. The investigation clearly showed that reducing the exposure rate of high-LET fast fission neutrons had no influence on the incidence of AML or on the survival of the irradiated mice. In contrast, a higher incidence of lymphosarcomas was observed in mice irradiated with higher exposure rates. (orig./MG).

  8. The calculation of individual radiation exposure rates arising from routine discharges of activity into an estuary or sea

    International Nuclear Information System (INIS)

    Maul, P.R.

    1982-03-01

    Simple methods are described which enable assessments to be made of exposure rates to individuals arising from the release of activity into an estuary or sea. These methods are based in the main on those employed by the Ministry of Agriculture Fisheries and Food together with models developed by the author. The exposure routes considered are the ingestion of seafood and external exposure from β and γ emitters arising from occupancy over contaminated sediments or beaches and the handling of fishing gear. These routes are generally the most important, but for any chosen site it will also be necessary to determine whether any other exposure routes are significant. (author)

  9. The calculation of individual radiation exposure rates arising from routine discharges of activity into an estuary or sea

    International Nuclear Information System (INIS)

    Maul, P.R.

    1982-11-01

    Simple methods are described which enable assessments to be made of exposure rates to individuals arising from the release of activity into an estuary or sea. These methods are based in the main on those employed by the Ministry of Agriculture Fisheries and Food together with models developed by the author. The exposure routes considered are the ingestion of seafood and external exposure from ν and ν emitters arising from occupancy over contaminated sediments or beaches and the handling of fishing gear. These routes are generally the most important, but for any chosen site it will also be necessary to determine whether any other exposure routes are significant. (author)

  10. Exposure assessment and heart rate variability monitoring in workers handling titanium dioxide particles: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Ichihara, Sahoko [Mie University, Graduate School of Regional Innovation Studies (Japan); Li, Weihua [WHO Collaborating Centre for Research in Human Reproduction, Shanghai Institute of Planned Parenthood Research (China); Omura, Seiichi [Tokyo Institute of Technology (Japan); Fujitani, Yuji [National Institute for Environmental Studies (Japan); Liu, Ying; Wang, Qiangyi [WHO Collaborating Centre for Research in Human Reproduction, Shanghai Institute of Planned Parenthood Research (China); Hiraku, Yusuke [Mie University Graduate School of Medicine, Department of Environmental and Molecular Medicine (Japan); Hisanaga, Naomi [Aichi Gakusen University, Faculty of Human Science and Design (Japan); Wakai, Kenji [Nagoya University Graduate School of Medicine, Department of Preventive Medicine (Japan); Ding, Xuncheng [WHO Collaborating Centre for Research in Human Reproduction, Shanghai Institute of Planned Parenthood Research (China); Kobayashi, Takahiro, E-mail: takakoba@airies.or.jp [Association for International Research Initiatives for Environmental Studies (Japan); Ichihara, Gaku, E-mail: gak@rs.tus.ac.jp [Tokyo University of Science, Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences (Japan)

    2016-03-15

    Titanium dioxide (TiO{sub 2}) particles are used for surface coating and in a variety of products such as inks, fibers, food, and cosmetics. The present study investigated possible respiratory and cardiovascular effects of TiO{sub 2} particles in workers exposed to this particle at high concentration in a factory in China. The diameter of particles collected on filters was measured by scanning electron microscopy. Real-time size-dependent particle number concentration was monitored in the nostrils of four workers using condensation particle counter and optical particle counter. Electrocardiogram was recorded using Holter monitors for the same four workers to record heart rate variability. Sixteen workers underwent assessment of the respiratory and cardiovascular systems. Mass-based individual exposure levels were also measured with personal cascade impactors. The primary particle diameter ranged from 46 to 562 nm. Analysis of covariance of the pooled data of the four workers showed that number of particles with a diameter <300 nm was associated positively with total number of N–N and negatively with total number of increase or decrease in successive RR intervals greater than 50 ms (RR50+/−) or percentage of RR 50+/− that were parameters of parasympathetic function. The total mass concentration was 9.58–30.8 mg/m{sup 3} during work, but significantly less before work (0.36 mg/m{sup 3}). The clear abnormality in respiratory function was not observed in sixteen workers who had worked for 10 months to 13 years in the factory. The study showed that exposure to particles with a diameter <300 nm might affect HRV in workers handling TiO{sub 2} particles. The results highlight the need to investigate the possible impact of exposure to nano-scaled particles on the autonomic nervous system.

  11. The Relationship of Practice Exposure and Injury Rate on Game Performance and Season Success in Professional Male Basketball

    Directory of Open Access Journals (Sweden)

    Toni Caparrós, Eduard Alentorn-Geli, Gregory D. Myer, Lluís Capdevila, Kristian Samuelsson, Bruce Hamilton, Gil Rodas

    2016-09-01

    Full Text Available The objectives of this study were to determine the relationship among game performance, injury rate, and practice exposure in a professional male basketball team. A retroospective analysis of prospective collected data was conducted over seven consecutive seasons (2007/2008 to 2013/2014. Data collection included sports performance during competition (statistical evaluation, injury rate, and total exposure (games and practices. Over the surveillance period, 162 injuries (91 practice; 71 matches occurred over 32,668 hours of exposure (556 games and 2005 practices. There was a strong positive correlation between: 1 exposure (total number of practices and hours of exposure and the total number of injuries (r = 0.77; p = 0.04; 2 exposure (total hours of exposure and total hours of practice exposure and performance (total team ranking (r = 0.77 and p = 0.04, and r = 0.8 and p = 0.03, respectively; and 3 total number of injuries and performance (total team ranking (r = 0.84; p = 0.02. While increasing practice and competition time is related to greater team performance, it also increases the number of injuries. However, higher injury rates were not associated with worse overall team performance. Efforts to reduce high-risk activity during practice, optimally replaced with injury prevention training, might help to reduce injury risk.

  12. Combined methodology for estimating dose rates and health effects from exposure to radioactive pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, D.E. Jr.; Leggett, R.W.; Yalcintas, M.G.

    1980-12-01

    The work described in the report is basically a synthesis of two previously existing computer codes: INREM II, developed at the Oak Ridge National Laboratory (ORNL); and CAIRD, developed by the Environmental Protection Agency (EPA). The INREM II code uses contemporary dosimetric methods to estimate doses to specified reference organs due to inhalation or ingestion of a radionuclide. The CAIRD code employs actuarial life tables to account for competing risks in estimating numbers of health effects resulting from exposure of a cohort to some incremental risk. The combined computer code, referred to as RADRISK, estimates numbers of health effects in a hypothetical cohort of 100,000 persons due to continuous lifetime inhalation or ingestion of a radionuclide. Also briefly discussed in this report is a method of estimating numbers of health effects in a hypothetical cohort due to continuous lifetime exposure to external radiation. This method employs the CAIRD methodology together with dose conversion factors generated by the computer code DOSFACTER, developed at ORNL; these dose conversion factors are used to estimate dose rates to persons due to radionuclides in the air or on the ground surface. The combination of the life table and dosimetric guidelines for the release of radioactive pollutants to the atmosphere, as required by the Clean Air Act Amendments of 1977.

  13. Estimating dose rates to organs as a function of age following internal exposure to radionuclides

    International Nuclear Information System (INIS)

    Leggett, R.W.; Eckerman, K.F.; Dunning, D.E. Jr.; Cristy, M.; Crawford-Brown, D.J.; Williams, L.R.

    1984-03-01

    The AGEDOS methodology allows estimates of dose rates, as a function of age, to radiosensitive organs and tissues in the human body at arbitrary times during or after internal exposure to radioactive material. Presently there are few, if any, radionuclides for which sufficient metabolic information is available to allow full use of all features of the methodology. The intention has been to construct the methodology so that optimal information can be gained from a mixture of the limited amount of age-dependent, nuclide-specific data and the generally plentiful age-dependent physiological data now available. Moreover, an effort has been made to design the methodology so that constantly accumulating metabolic information can be incorporated with minimal alterations in the AGEDOS computer code. Some preliminary analyses performed by the authors, using the AGEDOS code in conjunction with age-dependent risk factors developed from the A-bomb survivor data and other studies, has indicated that the doses and subsequent risks of eventually experiencing radiogenic cancers may vary substantially with age for some exposure scenarios and may be relatively invariant with age for other scenarios. We believe that the AGEDOS methodology provides a convenient and efficient means for performing the internal dosimetry

  14. The evaluation the magnitude radiation exposure dose rate in digital radiography room design

    Science.gov (United States)

    Dwiyanto, Agung; Setia Budi, Wahyu; Hardiman, Gagoek

    2017-12-01

    This study discusses the dose rate in digital radiography room, buit according to meet the provisions of KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation of BAPETEN No. 8 / 2011. The provisions primary concern of radiation safety, not comfort, by considering the space design. There are five aspects to consider in designing the space: functionality, comfort, security, movement activities and aesthetics. However provisions only met three aspects of the design, which are a function, security and movement activity. Therefore, it is necessary to evaluate digital radiography room in terms of its ability to control external radiation exposure to be safe and comfortable The dose rate is measured by the range of primary and secondary radiation in the observation points by using Surveymeter. All data are obtained by the preliminary survey prior to the study. Furthermore, the review of digital radiography room is done based on architectural design theory. The dose rate for recommended improvement room is recalculated using the same method as the actual room with the help of computer modeling. The result of dose rate calculation at the inner and outer part of digital radiography observation room shows that in-room dose for a week at each measuring point exceeds the allowable dose limit both for staff and public. During a week of observation, the outdoor dose at some measuring points exceeds the dose limit set by the KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation BEPETEN No 8/2011. Meanwhile, the result of dose rate calculation in the inner and outer part of the improved digital radiography room can meet the applicable regulations better.

  15. Breathing rates and daily activities: parameters of exposure to inhaled substances

    International Nuclear Information System (INIS)

    Roy, M.; Malarbet, J.L.; Courtay, C.

    1993-01-01

    The intake of inhaled toxic substances is based upon the air volumes breathed every day by people under exposure to gases and aerosols. On the occasion of the revision of the respiratory tract model by the International Commission on Radiological Protection (ICRP), modern standards have been assessed for average inspired air volumes according to age and sex. Recent data of breathing rates as a function of physical activity have been recorded, and economical surveys recently published by the National Institute of Statistics and Economical studies (INSEE) provided time budgets and activities of specific categories of the population. The results were calculated for adults and children, 3 months, 1, 5, 10 and 15 years old. These values are slightly different from those formerly published by ICRP and the United Nations scientific committee on the effects of atomic radiation (UNSCEAR). (author). 27 refs., 6 tabs

  16. Features of working in fields with high values of exposure dose rate

    International Nuclear Information System (INIS)

    Samojlenko, Yu.N.

    1989-01-01

    Features of working in fields with the exposure dose rate (EDR) ∼ 1000-7000 R/h are described. Data on the performed operations concerning initial decontamination of the Chernobyl-3 reactor roof during 10.07.86-03.10.86 are presented. It is marked that the methodical recommendations on working in fields with high values of EDR are absent in our country and abroad and it is necessary to develop them on the basis of obtained experience. Moreover, there are no protective means (protective clotting). Main principles of its creation are the protection of critical organ groups and comfort in working. Personnel should be specially trained and get phychologically ready. 2 figs., 1 tab

  17. Gamma exposure rate estimation in irradiation facilities of nuclear research reactors

    International Nuclear Information System (INIS)

    Daoud, Adrian

    2009-01-01

    There are experimental situations in the nuclear field, in which dose estimations due to energy-dependent radiation fields are required. Nuclear research reactors provide such fields under normal operation or due to radioactive disintegration of fission products and structural materials activation. In such situations, it is necessary to know the exposure rate of gamma radiation the different materials under experimentation are subject to. Detectors of delayed reading are usually used for this purpose. Direct evaluation methods using portable monitors are not always possible, because in some facilities the entrance with such devices is often impracticable and also unsafe. Besides, these devices only provide information of the place where the measurement was performed, but not of temporal and spatial fluctuations the radiation fields could have. In this work a direct evaluation method was developed for the 'in-situ' gamma exposure rate for the irradiation facilities of the RA-1 reactor. This method is also applicable in any similar installation, and may be complemented by delayed evaluations without problem. On the other hand, it is well known that the residual effect of radiation modifies some properties of the organic materials used in reactors, such as density, colour, viscosity, oxidation level, among others. In such cases, a correct dosimetric evaluation enables in service estimation of material duration with preserved properties. This evaluation is for instance useful when applied to lubricating oils for the primary circuit pumps in nuclear power plants, thus minimizing waste generation. In this work the necessary elements required to estimate in-situ time and space integrated dose are also established for a gamma irradiated sample in an irradiation channel of a nuclear facility with zero neutron flux. (author)

  18. Study of radiation exposure rate on the measurement points in Kartini reactor hall as based to determine operation safety parameters (KBO)

    International Nuclear Information System (INIS)

    Mahrus Salam; Elisabeth Supriyatni; Fajar Panuntun

    2016-01-01

    In the operation of nuclear facility there are safety parameters, which is the value of the conservatively maximum limit to ensure that all of the uncertainty in the analysis of facility operations safety have been considered, such as uncertainty of measurement, response time and uncertainty calculation tool, and is get a long to others value of normal operating condition limits, in other words, there are still allowed or permitted. Calculation of the radiation exposure rate on five measurement points (50 cm above the water surface of reactor pool, above interim storage (bulk shielding), reactor deck, thermal column and sub critical facility) and to be compared to the operation safety parameters (KBO) of Kartini reactor. The exposure rate value is obtained by calculating the source term of radioactivity on the core, attenuation resulting from the radiation shielding and measurement distance. From the calculation obtained that the value of gamma exposure rate of 50 cm above the water surface of reactor pool is 96.91 mR/hr (KBO<100 mR/hr), on the deck of Bulk Shielding amounted to 1.70 mR/h (KBO<2.5 mR/hr), on the reactor deck amounted to 5.73 mR/hr (KBO<10 mR/hr), on the Thermal Column amounted to 2.73 mR/hr (KBO<10 mR/hr) and on the sub critical facility amounted to 1.148 mR/hr (KBO<2.5 mR/hr). The value of gamma exposure rate at 5 locations measurements are still less than the operation safety parameters (KBO), it means that the reactor is safe to be operated. (author)

  19. A Monte Carlo program to calculate the exposure rate from airborne radioactive gases inside a nuclear reactor containment building.

    Science.gov (United States)

    Sherbini, S; Tamasanis, D; Sykes, J; Porter, S W

    1986-12-01

    A program was developed to calculate the exposure rate resulting from airborne gases inside a reactor containment building. The calculations were performed at the location of a wall-mounted area radiation monitor. The program uses Monte Carlo techniques and accounts for both the direct and scattered components of the radiation field at the detector. The scattered component was found to contribute about 30% of the total exposure rate at 50 keV and dropped to about 7% at 2000 keV. The results of the calculations were normalized to unit activity per unit volume of air in the containment. This allows the exposure rate readings of the area monitor to be used to estimate the airborne activity in containment in the early phases of an accident. Such estimates, coupled with containment leak rates, provide a method to obtain a release rate for use in offsite dose projection calculations.

  20. Investigation of the Effect of Occupational Noise Exposure on Blood Pressure and Heart Rate of Steel Industry Workers

    Science.gov (United States)

    Zamanian, Zahra; Rostami, Reza; Hasanzadeh, Jafar; Hashemi, Hassan

    2013-01-01

    Background and Objectives. This study aimed to investigate the effect of noise exposure on blood pressure and heart rate of steel industry workers. Materials and Methods. In the present cross-sectional study, 50 workers were selected from a steel company in Fars province, Iran, and exposed to 85, 95, and 105 dB noise levels for 5 minutes. The participants' blood pressure and heart rate were measured using Beurer BC16 pulse meter both before and after the exposure. Results. The study results showed no significant difference in blood pressure and heart rate before and after the exposure. However, the workers' systolic blood pressure had increased compared to before the exposure; of course, the difference was not statistically significant (P > 0.05). Besides, although the subjects' heart rate had reduced in comparison to before the exposure, the difference was not statistically significant (P > 0.05). Conclusion. No significant change was observed in blood pressure and heart rate after acute exposure to 85, 95, and 105 dB noise levels. PMID:23781252

  1. Investigation of the effect of occupational noise exposure on blood pressure and heart rate of steel industry workers.

    Science.gov (United States)

    Zamanian, Zahra; Rostami, Reza; Hasanzadeh, Jafar; Hashemi, Hassan

    2013-01-01

    This study aimed to investigate the effect of noise exposure on blood pressure and heart rate of steel industry workers. In the present cross-sectional study, 50 workers were selected from a steel company in Fars province, Iran, and exposed to 85, 95, and 105 dB noise levels for 5 minutes. The participants' blood pressure and heart rate were measured using Beurer BC16 pulse meter both before and after the exposure. The study results showed no significant difference in blood pressure and heart rate before and after the exposure. However, the workers' systolic blood pressure had increased compared to before the exposure; of course, the difference was not statistically significant (P > 0.05). Besides, although the subjects' heart rate had reduced in comparison to before the exposure, the difference was not statistically significant (P > 0.05). No significant change was observed in blood pressure and heart rate after acute exposure to 85, 95, and 105 dB noise levels.

  2. Time Course of Heart Rate Variability Response to PM2.5 Exposure from Secondhand Smoke.

    Directory of Open Access Journals (Sweden)

    Jennifer L Garza

    Full Text Available Exposure to secondhand smoke (SHS has been associated with decreased heart rate variability (HRV. However, the time course of this association is unclear. Therefore, the objective of this study was to investigate the association between 15-240 minute SHS-related fine particulate matter (PM2.5 moving averages and indices of HRV.With a panel study design, we used personal monitors to continuously measure PM2.5 and HRV of 35 participants who were exposed to SHS for approximately 6 hours.We observed negative, significant associations between 5-minute HRV indices and 15 minute PM2.5 moving averages and 240 minute PM2.5 moving averages: there was a significant (p<0.01 7.5% decrease in the 5-minute square root of the mean squared differences of successive normal heart beats associated with (RMSSD, and a significant (p<0.01 14.7% decrease in the 5-minute high frequency (HF power associated with the 15 minute PM2.5 moving averages; there was also a significant (p<0.01 46.9% decrease in the 5-minute RMSSD, and a significant (p<0.01 77.7% decrease in the 5-minute high frequency (HF power associated with the 240 minute PM2.5 moving averages.Our findings that exposure to SHS related PM2.5 was associated with HRV support the hypothesis that SHS can affect the cardiovascular system. The negative associations reported between short and longer term PM2.5 and HRV indicate adverse effects of SHS on the cardiovascular system.

  3. Symbolic Analysis of Heart Rate Variability During Exposure to Musical Auditory Stimulation.

    Science.gov (United States)

    Vanderlei, Franciele Marques; de Abreu, Luiz Carlos; Garner, David Matthew; Valenti, Vitor Engrácia

    2016-01-01

    In recent years, the application of nonlinear methods for analysis of heart rate variability (HRV) has increased. However, studies on the influence of music on cardiac autonomic modulation in those circumstances are rare. The research team aimed to evaluate the acute effects on HRV of selected auditory stimulation by 2 musical styles, measuring the results using nonlinear methods of analysis: Shannon entropy, symbolic analysis, and correlation-dimension analysis. Prospective control study in which the volunteers were exposed to music and variables were compared between control (no auditory stimulation) and during exposure to music. All procedures were performed in a sound-proofed room at the Faculty of Science and Technology at São Paulo State University (UNESP), São Paulo, Brazil. Participants were 22 healthy female students, aged between 18 and 30 y. Prior to the actual intervention, the participants remained at rest for 20 min, and then they were exposed to one of the selected types of music, either classical baroque (64-84 dB) or heavy-metal (75-84 dB). Each musical session lasted a total of 5 min and 15 s. At a point occurring up to 1 wk after that day, the participants listened to the second type of music. The 2 types of music were delivered in a random sequence that depended on the group to which the participant was assigned. The study analyzed the following HRV indices through Shannon entropy; symbolic analysis-0V%, 1V%, 2LV%, and 2ULV%; and correlation-dimension analysis. During exposure to auditory stimulation by heavy-metal or classical baroque music, the study established no statistically significant variations regarding the indices for the Shannon entropy; the symbolic analysis-0V%, 1V%, and 2ULV%; and the correlation-dimension analysis. However, during heavy-metal music, the 2LV% index in the symbolic analysis was reduced compared with the controls. Auditory stimulation with the heavy-metal music reduced the parasympathetic modulation of HRV

  4. Toxicokinetics of fumonisin B1 in turkey poults and tissue persistence after exposure to a diet containing the maximum European tolerance for fumonisins in avian feeds.

    Science.gov (United States)

    Tardieu, Didier; Bailly, Jean-Denis; Skiba, Fabien; Grosjean, François; Guerre, Philippe

    2008-09-01

    The kinetic of fumonisin B1 (FB1) after a single IV and oral dose, and FB1 persistence in tissue were investigated in turkey poults by HPLC after purification of samples on columns. After IV administration (single-dose: 10mg FB1/kg bw), serum concentration-time curves were best described by a three-compartment open model. Elimination half-life and mean residence time of FB1 were 85 and 52min, respectively. After oral administration (single-dose: 100mg FB1/kg bw) bioavailability was 3.2%; elimination half-life and mean residence time were 214 and 408min, respectively. Clearance of FB1 was 7.6 and 7.5ml/min/kg for IV and oral administration, respectively. Twenty-four hours after the administration of FB1 by the intravenous route, liver and kidney contained the highest levels of FB1 in tissues, level in muscle was low or below the limit of detection (LD, 13microg/kg). The persistence of FB1 in tissue was also studied after administration for 9 weeks of a feed that contained 5, 10 and 20mg FB1+FB2/kg diet. Eight hours after the last intake of 20mg FB1+FB2/kg feed (maximum recommended concentration of fumonisins established by the EU for avian feed), hepatic and renal FB1 concentrations were 119 and 22microg/kg, level in muscles was below the LD.

  5. Simulation of short-term fluctuations in gamma exposure rate due to radioactive cloud released from nuclear power plant

    International Nuclear Information System (INIS)

    Ichikawa, Yoichi; Shikata, Hiroshi; Ishida, Kenji; Ohba, Tachimori.

    1981-01-01

    The measured γ-exposure rate around nuclear power plants is due mainly to natural causes and radioactive clouds emitted from the plants. An exposure calculation method based on puff model has been already proposed to identify the plant contributions and to estimate values in response to short-term fluctuations of meteorological condition and the release rate. However, the calculation method by this model consumes a lot of computer time, since the calculation requires a three-dimensional integration of the distribution of the concentration from each puff. Hence, we propose a simplified method using approximate polynominal equations and interpolations. The computer time needed for the calculation with the simplified method is reduced to 1/30 of that required by the previous method. The calculation results by simplified method are compared with those by the previous method and with the measured exposure rate less natural background. The results of two different methods are in good agreement. The calculated exposure rate is within the range from half to twice as much as the measured exposure rate less background. (author)

  6. Expression of cytoskeletal and matrix genes following exposure to ionizing radiation: Dose-rate effects and protein synthesis requirements

    International Nuclear Information System (INIS)

    Woloschak, G.E.

    1994-01-01

    Experiments were designed to examine the effects Of radiation dose-rate and of the protein synthesis inhibitor cycloheximide on expression of cytoskeletal elements (γ- and β-actin and α-tubulin) and matrix elements (fibronectin) in Syrian hamster embryo cells. Past work from our laboratory had already demonstrated optimum time points and doses for examination of radiation effects on accumulation of specific transcripts. Our results here demonstrated little effect of dose-rate for JANUS fission spectrum neutrons when comparing expression of either α-tubulin or fibronectin genes. Past work had already documented similar results for expression of actin transcripts. Effects of cycloheximide revealed that cycloheximide repressed accumulation of α-tubulin following exposure to high dose-rate neutrons or γ rays; this did not occur following similar low dose-rate exposure. (2) Cycloheximide did not affect accumulation of MRNA for actin genes; and that cycloheximide abrogated the moderate induction of fibronectin-mRNA which occurred following exposure to γ rays and high dose-rate neutrons. These results suggest a role for labile proteins in the maintenance of α-tubulin and fibronectin MRNA accumulation following exposure to ionizing radiation. in addition, they suggest that the cellular/molecular response to low dose-rate neutrons may be different from the response to high dose-rate neutrons

  7. Expression of cytoskeletal and matrix genes following exposure to ionizing radiation: Dose-rate effects and protein synthesis requirements

    International Nuclear Information System (INIS)

    Woloschak, G.E.; Felcher, P.; Chang-Liu, Chin-Mei

    1992-01-01

    Experiments were designed to examine the effects of radiation dose-rate and of the protein synthesis inhibitor cycloheximide on expression of cytoskeletal elements (γ- and β-actin and α-tubulin) and matrix elements (fibronectin) in Syrian hamster embryo cells. Past work from our laboratory had already demonstrated optimum time points and doses for examination of radiation effects on accumulation of specific transcripts. Our results here demonstrated little effect of dose-rate for JANUS fission spectrum neutrons when comparing expression of either α-tubulin or fibronectin genes. Past work had already documented similar results for expression of actin transcripts. Effects of cycloheximide, however, revealed several interesting and novel findings: (1) Cycloheximide repressed accumulation of α-tubulin following exposure to high dose-rate neutrons or γ rays; this did not occur following similar low dose-rate exposure (2) Cycloheximide did not affect accumulation of mRNA for actin genes. Cycloheximide abrogated the moderate induction of fibronectin-mRNA which occurred following exposure to γ rays and high dose-rate neutrons. These results suggest a role for labile proteins in the maintenance of α-tubulin and fibronectin mRNA accumulation following exposure to ionizing radiation. In addition, they suggest that the cellular/molecular response to low dose-rate neutrons may be different from the response to high dose-rate neutrons

  8. Using a network-based approach and targeted maximum likelihood estimation to evaluate the effect of adding pre-exposure prophylaxis to an ongoing test-and-treat trial.

    Science.gov (United States)

    Balzer, Laura; Staples, Patrick; Onnela, Jukka-Pekka; DeGruttola, Victor

    2017-04-01

    Several cluster-randomized trials are underway to investigate the implementation and effectiveness of a universal test-and-treat strategy on the HIV epidemic in sub-Saharan Africa. We consider nesting studies of pre-exposure prophylaxis within these trials. Pre-exposure prophylaxis is a general strategy where high-risk HIV- persons take antiretrovirals daily to reduce their risk of infection from exposure to HIV. We address how to target pre-exposure prophylaxis to high-risk groups and how to maximize power to detect the individual and combined effects of universal test-and-treat and pre-exposure prophylaxis strategies. We simulated 1000 trials, each consisting of 32 villages with 200 individuals per village. At baseline, we randomized the universal test-and-treat strategy. Then, after 3 years of follow-up, we considered four strategies for targeting pre-exposure prophylaxis: (1) all HIV- individuals who self-identify as high risk, (2) all HIV- individuals who are identified by their HIV+ partner (serodiscordant couples), (3) highly connected HIV- individuals, and (4) the HIV- contacts of a newly diagnosed HIV+ individual (a ring-based strategy). We explored two possible trial designs, and all villages were followed for a total of 7 years. For each village in a trial, we used a stochastic block model to generate bipartite (male-female) networks and simulated an agent-based epidemic process on these networks. We estimated the individual and combined intervention effects with a novel targeted maximum likelihood estimator, which used cross-validation to data-adaptively select from a pre-specified library the candidate estimator that maximized the efficiency of the analysis. The universal test-and-treat strategy reduced the 3-year cumulative HIV incidence by 4.0% on average. The impact of each pre-exposure prophylaxis strategy on the 4-year cumulative HIV incidence varied by the coverage of the universal test-and-treat strategy with lower coverage resulting in a larger

  9. Seasonal variations of indoor microbial exposures and their relation to temperature, relative humidity, and air exchange rate.

    Science.gov (United States)

    Frankel, Mika; Bekö, Gabriel; Timm, Michael; Gustavsen, Sine; Hansen, Erik Wind; Madsen, Anne Mette

    2012-12-01

    Indoor microbial exposure has been related to adverse pulmonary health effects. Exposure assessment is not standardized, and various factors may affect the measured exposure. The aim of this study was to investigate the seasonal variation of selected microbial exposures and their associations with temperature, relative humidity, and air exchange rates in Danish homes. Airborne inhalable dust was sampled in five Danish homes throughout the four seasons of 1 year (indoors, n = 127; outdoors, n = 37). Measurements included culturable fungi and bacteria, endotoxin, N-acetyl-beta-d-glucosaminidase, total inflammatory potential, particles (0.75 to 15 μm), temperature, relative humidity, and air exchange rates. Significant seasonal variation was found for all indoor microbial exposures, excluding endotoxin. Indoor fungi peaked in summer (median, 235 CFU/m(3)) and were lowest in winter (median, 26 CFU/m(3)). Indoor bacteria peaked in spring (median, 2,165 CFU/m(3)) and were lowest in summer (median, 240 CFU/m(3)). Concentrations of fungi were predominately higher outdoors than indoors, whereas bacteria, endotoxin, and inhalable dust concentrations were highest indoors. Bacteria and endotoxin correlated with the mass of inhalable dust and number of particles. Temperature and air exchange rates were positively associated with fungi and N-acetyl-beta-d-glucosaminidase and negatively with bacteria and the total inflammatory potential. Although temperature, relative humidity, and air exchange rates were significantly associated with several indoor microbial exposures, they could not fully explain the observed seasonal variations when tested in a mixed statistical model. In conclusion, the season significantly affects indoor microbial exposures, which are influenced by temperature, relative humidity, and air exchange rates.

  10. Maximum power point tracking

    International Nuclear Information System (INIS)

    Enslin, J.H.R.

    1990-01-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

  11. Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems

    NARCIS (Netherlands)

    Blok, Chris; Jackson, Brian E.; Guo, Xianfeng; Visser, De Pieter H.B.; Marcelis, Leo F.M.

    2017-01-01

    Growing on rooting media other than soils in situ -i.e., substrate-based growing- allows for higher yields than soil-based growing as transport rates of water, nutrients, and oxygen in substrate surpass those in soil. Possibly water-based growing allows for even higher yields as transport rates of

  12. Effects of Moxa (Folium Artemisiae argyi Smoke Exposure on Heart Rate and Heart Rate Variability in Healthy Young Adults: A Randomized, Controlled Human Study

    Directory of Open Access Journals (Sweden)

    Yingxue Cui

    2013-01-01

    Full Text Available Objective. To determine the effects of the moxa smoke on human heart rate (HR and heart rate variability (HRV. Methods. Fifty-five healthy young adults were randomly divided into experimental (n=28 and control (n=27 groups. Experimental subjects were exposed to moxa smoke (2.5 ± 0.5 mg/m3 twice for 25 minutes in one week. ECG monitoring was performed before, during, and after exposure. Control subjects were exposed to normal indoor air in a similar environment and similarly monitored. Followup was performed the following week. Short-term (5 min HRV parameters were analyzed with HRV analysis software. SPSS software was used for statistical analysis. Results. During and after the first exposure, comparison of percentage changes or changes in all parameters between groups showed no significant differences. During the second exposure, percentage decrease in HR, percentage increases in lnTP, lnHF, lnLF, and RMSSD, and increase in PNN50 were significantly greater in the experimental group than in control. Conclusion. No significant adverse HRV effects were associated with this clinically routine 25-minute exposure to moxa smoke, and the data suggests that short-term exposure to moxa smoke might have positive regulating effects on human autonomic function. Further studies are warranted to confirm these findings.

  13. Changes in respiration rates and biomass attributes of epilithon due to extended exposure to zinc

    International Nuclear Information System (INIS)

    Colwell, F.S.

    1986-01-01

    The purpose of this research was to determine the influence of extended dosing of zinc on the carbon cycling and biomass characteristics of freshwater epilithon. Experiments were conducted in artificial streams continuously dosed with 0.00, 0.05, or 1.00 mg Zn liter -1 for 20 to 30 days during summer and fall, 1984 and 1985. Repeated measurement of epilithon structure and function included estimates of 14 C-glucose respiration, 14 C-glutamate respiration, O 2 and CO 2 flux rates, ash-free dry weight (AFDW), protein, carbohydrate, and algal pigment concentrations, and total and zinc-tolerant colony forming units. An increase in epilithic glucose respiration per unit biomass consistently occurred 5 to 10 days after dosing with 1.0 mg Zn liter -1 was started. At the same time significantly lower epilithon biomass occurred in the high dosed streams relative to controls in 3 out of 4 studies. Although algal pigment concentrations were lowest in the high dose streams at the midpoint of the studies, the chlorophyll a-to-pheophytin a ratio remained high, indicating that the minimal algal population was not senescing in situ. After 30 days, the epilithon dosed with 1.0 mg Zn liter -1 had higher AFDW, protein, and carbohydrate concentrations than the other treatments. The development of unique epilithon communities that are acclimated to prolonged zinc exposure is evident in the eventual recolonization of the artificial surfaces, glucose respiration rates that are comparable to controls, and presence of zinc-tolerant heterotrophs

  14. Readiness evaluation report -- High-exposure rate hardware removal resumption of activities

    International Nuclear Information System (INIS)

    Volkman, C.L.

    1996-11-01

    In August 1996, N Basin Project Management proactively ceased activities in the N Basin after noting several radiological control anomalies occurring during the performance of the high exposure rate hardware removal activity. The HERH is one of several activities that will be accomplished to complete deactivation of N Basin. Three project critiques were performed to identify causes and several corrective actions were identified. To ensure the true causes of the events were identified the N Basin Project Manager requested that a root cause analysis be performed for the events covered by the three critiques. The intent was to identify recurring events and evaluate the effectiveness of corrective action implementation. These three review elements were used by the project to develop a corrective action plan (CAP) which consisted of both project unique and programmatic items. The N Basin Project is using this BHI Readiness Evaluation (RE) process as a mechanism to independently verify that corrective actions identified from the CAP have been completed and that no changes have been made during the stand down that affect the resumption of the HERH activities. A readiness evaluation (RE) plan (Attachment 3) was prepared. The completed Readiness Evaluation Records which documents the results of the team member evaluations are in attachment 1. The independent readiness evaluation team identified 5 deficiencies of which two are post startup and three are pre startup. All deficiencies are in the area of training. These findings are explained in detail in Attachment 2

  15. Evaluating terrain based criteria for snow avalanche exposure ratings using GIS

    Science.gov (United States)

    Delparte, Donna; Jamieson, Bruce; Waters, Nigel

    2010-05-01

    Snow avalanche terrain in backcountry regions of Canada is increasingly being assessed based upon the Avalanche Terrain Exposure Scale (ATES). ATES is a terrain based classification introduced in 2004 by Parks Canada to identify "simple", "challenging" and "complex" backcountry areas. The ATES rating system has been applied to well over 200 backcountry routes, has been used in guidebooks, trailhead signs and maps and is part of the trip planning component of the AVALUATOR™, a simple decision-support tool for backcountry users. Geographic Information Systems (GIS) offers a means to model and visualize terrain based criteria through the use of digital elevation model (DEM) and land cover data. Primary topographic variables such as slope, aspect and curvature are easily derived from a DEM and are compatible with the equivalent evaluation criteria in ATES. Other components of the ATES classification are difficult to extract from a DEM as they are not strictly terrain based. An overview is provided of the terrain variables that can be generated from DEM and land cover data; criteria from ATES which are not clearly terrain based are identified for further study or revision. The second component of this investigation was the development of an algorithm for inputting suitable ATES criteria into a GIS, thereby mimicking the process avalanche experts use when applying the ATES classification to snow avalanche terrain. GIS based classifications were compared to existing expert assessments for validity. The advantage of automating the ATES classification process through GIS is to assist avalanche experts with categorizing and mapping remote backcountry terrain.

  16. High strain rate mechanical response of buttress-grooved tensile specimens which have undergone environmental exposure

    International Nuclear Information System (INIS)

    Weirick, L.J.

    1976-07-01

    The purpose of the corrosion compatibility program was to identify the effect of corrosion on the mechanical performance of the buttress-grooved section of the 105-mm penetrator, a section which must sustain a load during launch. It is important that the environment not deteriorate the mechanical integrity of these grooves during long-term storage. Both coated and uncoated test specimens which simulate both geometrical shape and residual stress patterns were exposed to corrosive environments of moist air, distilled water, and salt water. Some of these tests also incorporated the galvanic coupling caused by the aluminum sabot. After exposure to the corrosive environments, the specimens were pulled on a high strain rate tensile machine which simulated launch conditions. Results show that the galvanic coupling due to the aluminum sabot caused no deterioration of mechanical properties. Results do indicate that the coating applied caused a significant reduction in the fracture load. There was a dichotomy in the results as affected by the environment. Uncoated test specimens showed no change in fracture load with increasing severity of corrosion environment, whereas the coated specimens indicated a trend of decreasing load-bearing ability with increasing corrosion

  17. Association of soil arsenic and nickel exposure with cancer mortality rates, a town-scale ecological study in Suzhou, China.

    Science.gov (United States)

    Chen, Kai; Liao, Qi Lin; Ma, Zong Wei; Jin, Yang; Hua, Ming; Bi, Jun; Huang, Lei

    2015-04-01

    Heavy metals and arsenic are well-known carcinogens. However, few studies have examined whether soil heavy metals and arsenic concentrations associate with cancer in the general population. In this ecological study, we aimed to evaluate the association of heavy metals and arsenic in soil with cancer mortality rates during 2005-2010 in Suzhou, China, after controlling for education and smoking prevalence. In 2005, a total of 1683 soil samples with a sampling density of one sample every 4 km(2) were analyzed. Generalized linear model with a quasi-Poisson regression was applied to evaluate the association between town-scale cancer mortality rates and soil heavy metal concentrations. Results showed that soil arsenic exposure had a significant relationship with colon, gastric, kidney, lung, and nasopharyngeal cancer mortality rates and soil nickel exposure was significantly associated with liver and lung cancer. The associations of soil arsenic and nickel exposure with colon, gastric, kidney, and liver cancer in male were higher than those in female. The observed associations of soil arsenic and nickel with cancer mortality rates were less sensitive to alternative exposure metrics. Our findings would contribute to the understanding of the carcinogenic effect of soil arsenic and nickel exposure in general population.

  18. Secondhand tobacco smoke exposure and heart rate variability and inflammation among non-smoking construction workers: a repeated measures study.

    Science.gov (United States)

    Zhang, Jinming; Fang, Shona C; Mittleman, Murray A; Christiani, David C; Cavallari, Jennifer M

    2013-10-02

    Although it has been well recognized that exposure to secondhand tobacco smoke (SHS) is associated with cardiovascular mortality, the mechanisms and time course by which SHS exposure may lead to cardiovascular effects are still being explored. Non-smoking workers were recruited from a local union and monitored inside a union hall while exposed to SHS over approximately 6 hours. Participants were fitted with a continuous electrocardiographic monitor upon enrollment which was removed at the end of a 24-hr monitoring period. A repeated measures study design was used where resting ECGs and blood samples were taken from individuals before SHS exposure (baseline), immediately following SHS exposure (post) and the morning following SHS exposure (next-morning).Inflammatory markers, including high sensitivity C-reactive protein (CRP) and white blood cell count (WBC) were analyzed. Heart rate variability (HRV) was analyzed from the ECG recordings in time (SDNN, rMSSD) and frequency (LF, HF) domain parameters over 5-minute periods. SHS exposure was quantified using a personal fine particulate matter (PM2.5) monitor.Linear mixed effects regression models were used to examine within-person changes in inflammatory and HRV parameters across the 3 time periods. Exposure-response relationships with PM2.5 were examined using mixed effects models. All models were adjusted for age, BMI and circadian variation. A total of 32 male non-smokers were monitored between June 2010 and June 2012. The mean PM2.5 from SHS exposure was 132 μg/m3. Immediately following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with declines in HRV (7.8% [standard error (SE) =3%] SDNN, 8.0% (SE = 3.9%) rMSSD, 17.2% (SE = 6.3%) LF, 29.0% (SE = 10.1%) HF) and increases in WBC count 0.42 (SE = 0.14) k/μl. Eighteen hours following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with 24.2% higher CRP levels. Our study suggest that short-term SHS exposure is associated

  19. Advanced Computational Approaches for Characterizing Stochastic Cellular Responses to Low Dose, Low Dose Rate Exposures

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Bobby, R., Ph.D.

    2003-06-27

    applications of NEOTRANS2, indicate that nonlinear threshold-type, dose-response relationships for excess stochastic effects (problematic nonlethal mutations, neoplastic transformation) should be expected after exposure to low linear energy transfer (LET) gamma rays or gamma rays in combination with high-LET alpha radiation. Similar thresholds are expected for low-dose-rate low-LET beta irradiation. We attribute the thresholds to low-dose, low-LET radiation induced protection against spontaneous mutations and neoplastic transformations. The protection is presumed mainly to involve selective elimination of problematic cells via apoptosis. Low-dose, low-LET radiation is presumed to trigger wide-area cell signaling, which in turn leads to problematic bystander cells (e.g., mutants, neoplastically transformed cells) selectively undergoing apoptosis. Thus, this protective bystander effect leads to selective elimination of problematic cells (a tissue cleansing process in vivo). However, this protective bystander effects is a different process from low-dose stimulation of the immune system. Low-dose, low-LET radiation stimulation of the immune system may explain why thresholds for inducing excess cancer appear much larger (possibly more than 100-fold larger) than thresholds for inducing excess mutations and neoplastic transformations, when the dose rate is low. For ionizing radiation, the current risk assessment paradigm is such that the relative risk (RR) is always ¡Ý 1, no matter how small the dose. Our research results indicate that for low-dose or low-dose-rate, low-LET irradiation, RR < 1 may be more the rule than the exception. Directly tied to the current RR paradigm are the billion-dollar cleanup costs for radionuclide-contaminated DOE sites. Our research results suggest that continued use of the current RR paradigm for which RR ¡Ý 1 could cause more harm than benefit to society (e.g., by spreading unwarranted fear about phantom excess risks associated with low-dose low

  20. Exposure to Sexist Humor and Rape Proclivity: The Moderator Effect of Aversiveness Ratings

    Science.gov (United States)

    Romero-Sanchez, Monica; Duran, Mercedes; Carretero-Dios, Hugo; Megias, Jesus L.; Moya, Miguel

    2010-01-01

    The aim of this study is to explore the effect of exposure to sexist humor about women on men's self-reported rape proclivity. Earlier studies have shown that exposure to this type of humor increases rape proclivity and that funniness responses to jokes are a key element to consider. However, the role of aversiveness responses has not been…

  1. Dealing with consumer differences in liking during repeated exposure to food; typical dynamics in rating behavior

    NARCIS (Netherlands)

    Horst, ter G.J.; Renken, R.; Nanneti, L.; Dalenberg, J.R.; Wijk, de R.A.

    2014-01-01

    Consumers show high interindividual variability in food liking during repeated exposure. To investigate consumer liking during repeated exposure, data is often interpreted on a product level by averaging results over all consumers. However, a single product may elicit inconsistent behaviors in

  2. Dealing with Consumer Differences in Liking during Repeated Exposure to Food; Typical Dynamics in Rating Behavior

    NARCIS (Netherlands)

    Dalenberg, Jelle R.; Nanetti, Luca; Renken, Remco J.; de Wijk, Rene A.; ter Horst, Gert J.

    2014-01-01

    Consumers show high interindividual variability in food liking during repeated exposure. To investigate consumer liking during repeated exposure, data is often interpreted on a product level by averaging results over all consumers. However, a single product may elicit inconsistent behaviors in

  3. N Basin deactivation high exposure rate hardware container offgassing final report

    International Nuclear Information System (INIS)

    Day, R.S.; Palmer, D.L.; Pisarcik, D.J.; Vail, S.W.

    1996-11-01

    The N Reactor's 105-N Basin (N Basin) and the methods of packaging high-exposure rate hardware (HERH) were inspected, and gas bubbles were observed rising from the top surface of the third monolith prepared, Monolith No. 3. The HERH packaging was discontinued until the gas and the source could be explained and the safety of continued operation was verified. This report documents the investigation and the conclusions that support decisions regarding N Basin water removal, future storage, shipping, and Monolith No. 3 burial. Samples indicate that the gas emitted from Monolith No. 3 is almost exclusively hydrogen, containing some air and trace quantities of stable xenon. Gamma-energy analysis indicated trace amounts of 85 Kr in the samples. The literature review and the laboratory test results support the conclusion that aluminum is the only potentially grouted metal capable of corroding rapidly enough to generate the quantities of hydrogen gas that are observed. Based on aluminum components known to be found in the N Basin, the likely source of the aluminum is a used aluminum rupture can. All gas pockets in Monolith No. 3 caused by offgassing should be vented to the surface of the monolith. The peak offgas pressure within Monolith No. 3 (after it is removed from the N Basin water) should be approximately 0.62 psi above atmospheric pressure. Sufficient testing and analysis has been completed to remove Monolith No. 3 from the N Basin water and place the monolith in temporary storage until arrangements have been made for its shipment and disposition

  4. Effect of contraction mode of slow-speed resistance training on the maximum rate of force development in the human quadriceps

    DEFF Research Database (Denmark)

    Blazevich, Anthony J; Horne, Sara; Cannavan, Dale

    2008-01-01

    This study examined the effects of slow-speed resistance training involving concentric (CON, n = 10) versus eccentric (ECC, n = 11) single-joint muscle contractions on contractile rate of force development (RFD) and neuromuscular activity (EMG), and its maintenance through detraining. Isokinetic...

  5. Voluntary drive-dependent changes in vastus lateralis motor unit firing rates during a sustained isometric contraction at 50% of maximum knee extension force.

    NARCIS (Netherlands)

    de Ruiter, C.J.; Elzinga, M.J.; Verdijk, PW; van Mechelen, W.; de Haan, A.

    2004-01-01

    The purpose of the present study was to relate the expected inter-subject variability in voluntary drive of the knee extensor muscles during a sustained isometric contraction to the changes in firing rates of single motor units. Voluntary activation, as established with super-imposed electrical

  6. Evaluation of the contribution of contamination of radiotherapy room surfaces in the measure of exposure rate of radioiodine therapy patients

    International Nuclear Information System (INIS)

    Campos, Rafael Ferreira

    2015-01-01

    The contamination of radiotherapy room surfaces is significant and the measures of patient exposure rate are held on the fourth dependencies, relevant questions are raised: the background radiation of the room stay high due to surface contamination, may interfere with the rate of patient exposure at the time of its release? The monitoring site is important to determine whether the patient will be released? The value of the deal activity and the clinical condition of the patient may increase the contamination, influencing the monitoring results? This paper aims to conduct a quantitative analysis of surface contamination of the contribution of therapeutic room at the time is monitored exposure rate from inpatient. Measurements were made regarding the hospitalization of 32 patients with different doses administered activity, age and of both genders. The measurements were performed in the therapeutic rooms at the hospital Brotherhood Santa Casa de Misericordia de Sao Paulo. Exposure rate measurements were performed at the center of the room at 1 meter of the patient on the day of its release. After his release and prior to decontamination, measurements were performed at predetermined landmarks within the therapeutic room. The results revealed that on average background radiation, high due to surface contamination contributes only 2% of the patient dose rate. It can be considered that even with influence of contamination of surfaces, this is insignificant to determine if the patient may or may not be released. This study suggests that the site in which monitoring occurs exposure rate of the patient should not be decisive for liberation thereof. (author)

  7. Development of the town data base: Estimates of exposure rates and times of fallout arrival near the Nevada Test Site

    International Nuclear Information System (INIS)

    Thompson, C.B.; McArthur, R.D.; Hutchinson, S.W.

    1994-09-01

    As part of the U.S. Department of Energy's Off-Site Radiation Exposure Review Project, the time of fallout arrival and the H+12 exposure rate were estimated for populated locations in Arizona, California, Nevada, and Utah that were affected by fallout from one or more nuclear tests at the Nevada Test Site. Estimates of exposure rate were derived from measured values recorded before and after each test by fallout monitors in the field. The estimate for a given location was obtained by retrieving from a data base all measurements made in the vicinity, decay-correcting them to H+12, and calculating an average. Estimates were also derived from maps produced after most events that show isopleths of exposure rate and time of fallout arrival. Both sets of isopleths on these maps were digitized, and kriging was used to interpolate values at the nodes of a 10-km grid covering the pattern. The values at any location within the grid were then estimated from the values at the surrounding grid nodes. Estimates of dispersion (standard deviation) were also calculated. The Town Data Base contains the estimates for all combinations of location and nuclear event for which the estimated mean H+12 exposure rate was greater than three times background. A listing of the data base is included as an appendix. The information was used by other project task groups to estimate the radiation dose that off-site populations and individuals may have received as a result of exposure to fallout from Nevada nuclear tests

  8. Estimated effective dose rates from radon exposure in workplaces and residences within Los Alamos county in New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, Jeffrey J [Los Alamos National Laboratory; Mcnaughton, Michael [Los Alamos National Laboratory

    2009-01-01

    Many millions of office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the workplace are lacking. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were then used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about nine times greater exposure at home than while in the office (691 mrem yr{sup -1} versus 78 mrem yr{sup -1}). The estimated effective dose rate for a more homebound person was 896 mrem yr{sup -1}. These effective dose rates are contrasted against the 100 mrem yr{sup -1} threshold for regulation of a 'radiological worker' defined in the Department of Energy regulations occupational exposure and the 10 mrem yr{sup -1} air pathway effective public dose limit regulated by the Environmental Protection Agency.

  9. The importance of corporate foreign debt as an alternative to currency derivatives in actual management of exchange rate exposures

    DEFF Research Database (Denmark)

    Aabo, Tom

    This empirical study of the exchange rate exposure management of Danish non-financial firms listed on the Copenhagen Stock Exchange shows that debt denominated in foreign currency ("foreign debt") is a very important alternative to the use of currency derivatives. The results show that the relati...

  10. Isopleths of surface concentration and surface exposure rate due to a radioactive cloud released from a stack

    International Nuclear Information System (INIS)

    Kobayashi, Hideo; Yabuta, Hajimu; Katagiri, Hiroshi; Obata, Kazuichi; Kokubu, Morinobu

    1982-03-01

    Various calculations are made to estimate the distributions of concentration and γ-exposure rate due to a radioactive cloud released from a point source to the atmosphere. In this report, the isopleths of concentration and γ-exposure rate which were calculated are given in graphs to enable rapid prediction of the influence of released radioactive material in the emergency situation. Recently there are facilities which are equipped with a system to display the calculation results on CRT; but such practice is rather rare. By placing the calculated isopleths of reduction scale 1/25000 or 1/50000 on the usual map, any facilities without the CRT system can readily estimate the influence of an accidental release. The graphs of isopleths are given with the release height (11 values of 0 to 200 m at about 20 m intervals) and the atmospheric stability (6 classes) as parameters. Calculations of γ-exposure rates were made using the computer code GAMPUL developed by T. Hayashi and T. Shiraishi. In the calculation of radioactive concentrations and γ-exposure rates, the vertical diffusion depths, σsub(z), exceeding 1000 m are taken to be 1000 m according to the Meteorological Guide for the Safety Analysis of Power Reactor (J.AEC). The comparison between with and without this limitation in σsub(z) is made in the case of downwind axial surface distributions. (author)

  11. ESTIMATED RATE OF FATAL AUTOMOBILE ACCIDENTS ATTRIBUTABLE TO ACUTE SOLVENT EXPOSURE AT LOW INHALED CONCENTRATIONS

    Science.gov (United States)

    Acute solvent exposures may contribute to automobile accidents because they increase reaction time and decrease attention, in addition to impairing other behaviors. These effects resemble those of ethanol consumption, both with respect to behavioral effects and neurological mecha...

  12. Changes in Extreme Maximum Temperature Events and Population Exposure in China under Global Warming Scenarios of 1.5 and 2.0°C: Analysis Using the Regional Climate Model COSMO-CLM

    Science.gov (United States)

    Zhan, Mingjin; Li, Xiucang; Sun, Hemin; Zhai, Jianqing; Jiang, Tong; Wang, Yanjun

    2018-02-01

    We used daily maximum temperature data (1986-2100) from the COSMO-CLM (COnsortium for Small-scale MOdeling in CLimate Mode) regional climate model and the population statistics for China in 2010 to determine the frequency, intensity, coverage, and population exposure of extreme maximum temperature events (EMTEs) with the intensity-area-duration method. Between 1986 and 2005 (reference period), the frequency, intensity, and coverage of EMTEs are 1330-1680 times yr-1, 31.4-33.3°C, and 1.76-3.88 million km2, respectively. The center of the most severe EMTEs is located in central China and 179.5-392.8 million people are exposed to EMTEs annually. Relative to 1986-2005, the frequency, intensity, and coverage of EMTEs increase by 1.13-6.84, 0.32-1.50, and 15.98%-30.68%, respectively, under 1.5°C warming; under 2.0°C warming, the increases are 1.73-12.48, 0.64-2.76, and 31.96%-50.00%, respectively. It is possible that both the intensity and coverage of future EMTEs could exceed the most severe EMTEs currently observed. Two new centers of EMTEs are projected to develop under 1.5°C warming, one in North China and the other in Southwest China. Under 2.0°C warming, a fourth EMTE center is projected to develop in Northwest China. Under 1.5 and 2.0°C warming, population exposure is projected to increase by 23.2%-39.2% and 26.6%-48%, respectively. From a regional perspective, population exposure is expected to increase most rapidly in Southwest China. A greater proportion of the population in North, Northeast, and Northwest China will be exposed to EMTEs under 2.0°C warming. The results show that a warming world will lead to increases in the intensity, frequency, and coverage of EMTEs. Warming of 2.0°C will lead to both more severe EMTEs and the exposure of more people to EMTEs. Given the probability of the increased occurrence of more severe EMTEs than in the past, it is vitally important to China that the global temperature increase is limited within 1.5°C.

  13. Measurement and monitoring of entrance exposure dose rate in X-ray image intensifier television with dose rate control

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J [Bezirkskrankenhaus Brandenburg (German Democratic Republic)

    1981-03-01

    For X-ray image intensifier television operation very low entrance dose rates (about 5.2 nA/kg) are stated and demanded, respectively. These required values are often manifold exceeded in practice so that a check seems to be necessary. It is shown and proved how these measurements can be performed with simple, generally available means of measurement in the radiological practice. For ZnCdS-image intensifiers should be considered that about 13 nA/kg for the large entrance size are not to be exceeded; for the CsI type lower values (factor 1.5) are practicable because of the twofold quantum absorption efficiency. Furthermore, some tests for a semiquantitative function check of the automatic dose rate control are proposed.

  14. The Hanford Site's Gable Mountain structure: A comparison of the recurrence of design earthquakes based on fault slip rates and a probabilistic exposure model

    International Nuclear Information System (INIS)

    Rohay, A.C.

    1991-01-01

    Gable Mountain is a segment of the Umtanum Ridge-Gable Mountain structural trend, an east-west trending series of anticlines, one of the major geologic structures on the Hanford Site. A probabilistic seismic exposure model indicates that Gable Mountain and two adjacent segments contribute significantly to the seismic hazard at the Hanford Site. Geologic measurements of the uplift of initially horizontal (11-12 Ma) basalt flows indicate that a broad, continuous, primary anticline grew at an average rate of 0.009-0.011 mm/a, and narrow, segmented, secondary anticlines grew at rates of 0.009 mm/a at Gable Butte and 0.018 mm/a at Gable Mountain. The buried Southeast Anticline appears to have a different geometry, consisting of a single, intermediate-width anticline with an estimated growth rate of 0.007 mm/a. The recurrence rate and maximum magnitude of earthquakes for the fault models were used to estimate the fault slip rate for each of the fault models and to determine the implied structural growth rate of the segments. The current model for Gable Mountain-Gable Butte predicts 0.004 mm/a of vertical uplift due to primary faulting and 0.008 mm/a due to secondary faulting. These rates are roughly half the structurally estimated rates for Gable Mountain, but the model does not account for the smaller secondary fold at Gable Butte. The model predicted an uplift rate for the Southeast Anticline of 0.006 mm/a, caused by the low open-quotes fault capabilityclose quotes weighting rather than a different fault geometry. The effects of previous modifications to the fault models are examined and potential future modifications are suggested. For example, the earthquake recurrence relationship used in the current exposure model has a b-value of 1.15, compared to a previous value of 0.85. This increases the implied deformation rates due to secondary fault models, and therefore supports the use of this regionally determined b-value to this fault/fold system

  15. Publicizing Your Web Resources for Maximum Exposure.

    Science.gov (United States)

    Smith, Kerry J.

    2001-01-01

    Offers advice to librarians for marketing their Web sites on Internet search engines. Advises against relying solely on spiders and recommends adding metadata to the source code and delivering that information directly to the search engines. Gives an overview of metadata and typical coding for meta tags. Includes Web addresses for a number of…

  16. Determination of gamma-ray exposure rate from short-lived fission products under criticality accident conditions

    International Nuclear Information System (INIS)

    Yanagisawa, Hiroshi; Ohno, Akio; Aizawa, Eijyu

    2002-01-01

    For the assessment of γ-ray doses from short-lived fission products (FPs) under criticality accident conditions, γ-ray exposure rates varying with time were experimentally determined in the Transient Experiment Critical Facility (TRACY). The data were obtained by reactivity insertion in the range of 1.50 to 2.93$. It was clarified from the experiments that the contribution of γ-ray from short-lived FPs to total exposure during the experiments was evaluated to be 15 to 17%. Hence, the contribution cannot be neglected for the assessment of γ-ray doses under criticality accident conditions. Computational analyses also indicated that γ-ray exposure rates from short-lived FPs calculated with the Monte Carlo code, MCNP4B, and photon sources based on the latest FP decay data, the JENDL FP Decay Data File 2000, well agreed with the experimental results. The exposure rates were, however, extremely underestimated when the photon sources were obtained by the ORIGEN2 code. The underestimation is due to lack of energy-dependent photon emission data for major short-lived FP nuclides in the photon database attached to the ORIGEN2 code. It was also confirmed that the underestimation arose in 1,000 or less of time lapse after an initial power burst. (author)

  17. Two Mechanisms: The Role of Social Capital and Industrial Pollution Exposure in Explaining Racial Disparities in Self-Rated Health.

    Science.gov (United States)

    Ard, Kerry; Colen, Cynthia; Becerra, Marisol; Velez, Thelma

    2016-10-19

    This study provides an empirical test of two mechanisms (social capital and exposure to air pollution) that are theorized to mediate the effect of neighborhood on health and contribute to racial disparities in health outcomes. To this end, we utilize the Social Capital Benchmark Study, a national survey of individuals nested within communities in the United States, to estimate how multiple dimensions of social capital and exposure to air pollution, explain racial disparities in self-rated health. Our main findings show that when controlling for individual-confounders, and nesting within communities, our indicator of cognitive bridging, generalized trust, decreases the gap in self-rated health between African Americans and Whites by 84%, and the gap between Hispanics and Whites by 54%. Our other indicator of cognitive social capital, cognitive linking as represented by engagement in politics, decreases the gap in health between Hispanics and Whites by 32%, but has little impact on African Americans. We also assessed whether the gap in health was explained by respondents' estimated exposure to toxicity-weighted air pollutants from large industrial facilities over the previous year. Our results show that accounting for exposure to these toxins has no effect on the racial gap in self-rated health in these data. This paper contributes to the neighborhood effects literature by examining the impact that estimated annual industrial air pollution, and multiple measures of social capital, have on explaining the racial gap in health in a sample of individuals nested within communities across the United States.

  18. The measurement of exposure rate and absorbed dose for photons of 6 to 7 MeV

    International Nuclear Information System (INIS)

    Birchall, I.

    1978-01-01

    Using the 16 N source at the Universities Reactor Centre, which provides a source of high energy photons of 6 and 7 MeV, experiments have been carried out to provide a calibration point for secondary standard and general survey instruments. The source was designed primarily for shielding experiments and suffers from a number of disadvantages if precise dose or exposure data are required. In particular the exposure rate is low, the source is physically large and the energy spectrum is contaminated with lower energy photons. A summary of the basic techniques is given because of the inherent difficulties in dose measurements particularly for high energy photons. (author)

  19. Maximum Urine Flow Rate of Less than 15ml/Sec Increasing Risk of Urine Retention and Prostate Surgery among Patients with Alpha-1 Blockers: A 10-Year Follow Up Study.

    Directory of Open Access Journals (Sweden)

    Hsin-Ho Liu

    Full Text Available The aim of this study was to determine the subsequent risk of acute urine retention and prostate surgery in patients receiving alpha-1 blockers treatment and having a maximum urinary flow rate of less than 15ml/sec.We identified patients who were diagnosed with benign prostate hyperplasia (BPH and had a maximum uroflow rate of less than 15ml/sec between 1 January, 2002 to 31 December, 2011 from Taiwan's National Health Insurance Research Database into study group (n = 303. The control cohort included four BPH/LUTS patients without 5ARI used for each study group, randomly selected from the same dataset (n = 1,212. Each patient was monitored to identify those who subsequently developed prostate surgery and acute urine retention.Prostate surgery and acute urine retention are detected in 5.9% of control group and 8.3% of study group during 10-year follow up. Compared with the control group, there was increase in the risk of prostate surgery and acute urine retention in the study group (HR = 1.83, 95% CI: 1.16 to 2.91 after adjusting for age, comorbidities, geographic region and socioeconomic status.Maximum urine flow rate of less than 15ml/sec is a risk factor of urinary retention and subsequent prostate surgery in BPH patients receiving alpha-1 blocker therapy. This result can provide a reference for clinicians.

  20. Characterization of the heart rate curve during a maximum incremental test on a treadmill. DOI: 10.5007/1980-0037.2011v13n4p285

    Directory of Open Access Journals (Sweden)

    Eduardo Marcel Fernandes Nascimento

    2011-08-01

    Full Text Available The objective of this study was to analyze the heart rate (HR profile plotted against incremental workloads (IWL during a treadmill test using three mathematical models [linear, linear with 2 segments (Lin2, and sigmoidal], and to determine the best model for the identification of the HR threshold that could be used as a predictor of ventilatory thresholds (VT1 and VT2. Twenty-two men underwent a treadmill incremental test (retest group: n=12 at an initial speed of 5.5 km.h-1, with increments of 0.5 km.h-1 at 1-min intervals until exhaustion. HR and gas exchange were continuously measured and subsequently converted to 5-s and 20-s averages, respectively. The best model was chosen based on residual sum of squares and mean square error. The HR/IWL ratio was better fitted with the Lin2 model in the test and retest groups (p0.05. During a treadmill incremental test, the HR/IWL ratio seems to be better fitted with a Lin2 model, which permits to determine the HR threshold that coincides with VT1.

  1. Influence of radon-daughter exposure rate and uranium ore dust concentration on occurrence of lung tumors

    International Nuclear Information System (INIS)

    Cross, F.T.; Palmer, R.F.; Busch, R.H.

    1980-01-01

    Groups of male SPF Wistar rats were exposed concurrently to several levels of radon daughters and uranium ore dust to study the effect of these variables on pulmonary disease states. Clinical pathology data at 1 yr postexposure indicate no significant differences among exposed animals when compared with controls. Preliminary histopathologic data suggest a trend toward increasing lung tumor risk as the exposure rate is decreased (constant total dose), but the differences are not statistically significant at the 0.05 level. A similar trend occurs with decrease in ore dust concentration (except for the 2560-WLM exposure group), but these differences are also not significant at the 0.05 level. The tumor risk is significantly (0.05 level) increased as the exposure level increases from approximately 320 and 640 WLM to 2560 WLM at the high ore dust concentration

  2. Clear as Mud: Changes in Paleoshelf Environments and Deposition Rates at Medford, New Jersey during the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Podrecca, L.; Miller, K. G.; Wright, J. D.; Browning, J. V.; Emge, T.

    2017-12-01

    The Paleocene-Eocene boundary marks a time of swift global climatic change. Constraining the timeframe of this event is a first order question necessary for ascertaining the origin of the event and the potential for its use as an analog for modern climate change. The New Jersey shelf sediments of the Marlboro Formation records this time period with exceptionally thick (5-15m) records of the period of global low carbon isotopic values ("the core") which requires minimum sedimentation rates of 10's cm/kyr. Rhythmic layers have been previously reported from Wilson Lake & Millville, NJ (IODP Leg 174AX). These structures coined "laminae couplets" consist of semi-periodic 1-2mm thick raised laminations separated by matrix of varying width (averaging 1.8cm). These have been dismissed as artifacts of drilling "biscuits". We report here on a series of shallow auger cores drilled on a transect at Medford, NJ, without using drilling fluid. These cores also show a similar set of structures on the 2cm scale verifying that they are primary depositional features. The mm width laminae in the auger core show remarkable swelling within minutes of splitting. XRD, XRF, bulk carbonate geochemistry, and grain size analysis have been determined at regular depth intervals throughout the core. We have analyzed differences in these parameters between the laminae and interbedded matrix material, as well as across the transect as a whole. In general, the Marlboro formation at this updip location consists of micaceous, lignitic, very clayey silt (mean size 6 micrometers) with occasional organic debris indicating proximal deposition from a fluvial system. Paleodepth of 40m and normal marine salinities are estimated using a paleoslope model and the presence of common though not abundant planktonic foraminifera. We discuss a model of deposition for the Marlboro Formation as fluid mud (nearbed suspension flows) associated with the "Appalachian Amazon" alluding toward the finer grained inter

  3. Hepatitis B Virus Infection and Immunizations among Asian American College Students: Infection, Exposure, and Immunity Rates

    Science.gov (United States)

    Lee, Haeok; Kiang, Peter; Watanabe, Paul; Halon, Patricia; Shi, Ling; Church, Daniel R.

    2013-01-01

    Objectives: To evaluate the prevalence of hepatitis B virus (HBV) infection, exposure, and immunity among Asian American college students as a basis for evaluating HBV screening and vaccination policy. Participants and Methods: Self-identified Asian American college students aged 18 years or older were examined. Serological tests of HBV surface…

  4. Electron dose-rate conversion factors for external exposure of the skin from uniformly deposited activity on the body surface

    International Nuclear Information System (INIS)

    Kocher, D.C.; Eckerman, K.F.

    1987-01-01

    Dose-rate conversion factors have been calculated for external exposure of the skin from electrons emitted by sources that are deposited uniformly on the body surface. The dose-rate factors are obtained from electron scaled point kernels developed by Berger. The dose-rate factors are calculated at depths of 4, 8, and 40 mg cm-2 below the body surface as recommended by Whitton, and at a depth of 7 mg cm-2 as recommended in ICRP Publication 26 (ICRP77). The dependence of the dose-rate factors at selected depths on the energy of the emitted electrons is displayed. The dose-rate factors for selected radionuclides of potential importance in radiological assessments are tabulated

  5. Physiological Responses, Growth Rate and Blood Metabolites Under Feed Restriction and Thermal Exposure in Kids

    Directory of Open Access Journals (Sweden)

    O.K. Hooda

    2014-05-01

    Full Text Available The study was carried out to study the cumulative effect of thermal stress and feed restriction in kids. Twelve kids of Alpine x Beetle cross were divided into two groups. Group 1 served as control and group 2 was put on restricted feeding and exposed at 40, 42 and 44oC. Body weights of both groups were similar before thermal exposure and feed restriction. Body weight of group 1 increased significantly and were higher than group 2 throughout the experiment. Body weight gain, average daily gain and feed conversion efficiency were comparable in both groups after removal of thermal stress and switching over to ad libitum feeding (42-63 days. Body weights of group 2 remained lower than group 1, the losses in body weights of group 2 could not be compensated and there was approximately 25% loss in body weight at the end of experiment. Physiological responses of group 2 were significantly lower before exposure to high temperature but increased significantly after exposure at temperature 40, 42 and 44oC and the increase was in commensurate with the increase in exposure temperature. Blood glucose, total protein, albumin and serum enzymes decreased significantly on exposure at higher temperature and differences were higher in feed restricted group. T3, T4 and cortisol concentration were similar in both groups before feed restriction and thermal stress. T3, T4 concentration decreased while cortisol concentration increased significantly after exposure to high temperature. Variations in plasma enzymes, acid phosphatase, alkaline phosphatase, SGOT and SGPT were not significant before feed restriction and thermal stress. The activities of acid phosphatase and alkaline phosphatase decreased whereas that of SGOT and SGPT increased significantly on exposure at temperature 40oC and subsequent changes at temperature 42 and 44oC were not significant. The study indicated that animals of group 2 experienced more stress as observed by significant alteration in body

  6. PM2.5 metal exposures and nocturnal heart rate variability: a panel study of boilermaker construction workers

    Directory of Open Access Journals (Sweden)

    Herrick Robert F

    2008-07-01

    Full Text Available Abstract Background To better understand the mechanism(s of particulate matter (PM associated cardiovascular effects, research priorities include identifying the responsible PM characteristics. Evidence suggests that metals play a role in the cardiotoxicity of fine PM (PM2.5 and in exposure-related decreases in heart rate variability (HRV. We examined the association between daytime exposure to the metal content of PM2.5 and night HRV in a panel study of boilermaker construction workers exposed to metal-rich welding fumes. Methods Twenty-six male workers were monitored by ambulatory electrocardiogram (ECG on a workday while exposed to welding fume and a non-workday (baseline. From the ECG, rMSSD (square root of the mean squared differences of successive intervals was summarized over the night (0:00–7:00. Workday, gravimetric PM2.5 samples were analyzed by x-ray fluorescence to determine metal content. We used linear mixed effects models to assess the associations between night rMSSD and PM2.5 metal exposures both with and without adjustment for total PM2.5. Matched ECG measurements from the non-workday were used to control for individual cardiac risk factors and models were also adjusted for smoking status. To address collinearity between PM2.5 and metal content, we used a two-step approach that treated the residuals from linear regression models of each metal on PM2.5 as surrogates for the differential effects of metal exposures in models for night rMSSD. Results The median PM2.5 exposure was 650 μg/m3; median metal exposures for iron, manganese, aluminum, copper, zinc, chromium, lead, and nickel ranged from 226 μg/m3 to non-detectable. We found inverse linear associations in exposure-response models with increased metal exposures associated with decreased night rMSSD. A statistically significant association for manganese was observed, with a decline of 0.130 msec (95% CI: -0.162, -0.098 in night rMSSD for every 1 μg/m3 increase in

  7. Computational modeling and statistical analyses on individual contact rate and exposure to disease in complex and confined transportation hubs

    Science.gov (United States)

    Wang, W. L.; Tsui, K. L.; Lo, S. M.; Liu, S. B.

    2018-01-01

    Crowded transportation hubs such as metro stations are thought as ideal places for the development and spread of epidemics. However, for the special features of complex spatial layout, confined environment with a large number of highly mobile individuals, it is difficult to quantify human contacts in such environments, wherein disease spreading dynamics were less explored in the previous studies. Due to the heterogeneity and dynamic nature of human interactions, increasing studies proved the importance of contact distance and length of contact in transmission probabilities. In this study, we show how detailed information on contact and exposure patterns can be obtained by statistical analyses on microscopic crowd simulation data. To be specific, a pedestrian simulation model-CityFlow was employed to reproduce individuals' movements in a metro station based on site survey data, values and distributions of individual contact rate and exposure in different simulation cases were obtained and analyzed. It is interesting that Weibull distribution fitted the histogram values of individual-based exposure in each case very well. Moreover, we found both individual contact rate and exposure had linear relationship with the average crowd densities of the environments. The results obtained in this paper can provide reference to epidemic study in complex and confined transportation hubs and refine the existing disease spreading models.

  8. Heart rate variability and the relationship between trauma exposure age, and psychopathology in a post-conflict setting.

    Science.gov (United States)

    Liddell, Belinda J; Kemp, Andrew H; Steel, Zachary; Nickerson, Angela; Bryant, Richard A; Tam, Natalino; Tay, Alvin Kuowei; Silove, Derrick

    2016-05-10

    Cumulative exposure to potentially traumatic events (PTEs) increases risk for mental distress in conflict-affected settings, but the psychophysiological mechanisms that mediate this dose-response relationship are unknown. We investigated diminished heart rate variability (HRV) - an index of vagus nerve function and a robust predictor of emotion regulation capacity - as a vulnerability marker that potentially mediates the association between PTE exposure, age and symptoms of posttraumatic stress disorder (PTSD), psychological distress and aggressive behavior, in a community sample from Timor-Leste - a post-conflict country with a history of mass violence. Resting state heart rate data was recorded from 45 cases of PTSD, depression and intermittent explosive disorder (IED); and 29 non-case controls. Resting HRV was significantly reduced in the combined case group compared with non-cases (p = .021; Cohen's d = 0.5). A significant mediation effect was also observed, whereby a sequence of increased age, reduced HRV and elevated PTSD symptoms mediated the association between PTE exposure and distress (B = .06, SE = .05, 95% CI = [.00-.217]) and aggression (B = .02, SE = .02, 95% CI = [.0003-.069])). The findings demonstrate an association between diminished resting HRV and psychopathology. Moreover, age-related HRV reductions emerged as a potential psychophysiological mechanism that underlies enhanced vulnerability to distress and aggression following cumulative PTE exposure.

  9. Cash Flows versus Accounting Earnings in Managing Exchange Rate Exposures: An Empirical Study of Non-Financial Companies

    DEFF Research Database (Denmark)

    Aabo, Tom

    Financial theory argues that companies should manage cash flows and not accounting earnings when they hedge exchange rate exposures. Still, empirical evidence shows that a number of companies choose to manage accounting earnings. This empirical study of Danish, non-financial companies finds (1......) that when hedging the majority of companies expect to add value to their company by avoiding financial distress (reduce down side risk), (2) that when hedging managing cash flows versus managing accounting earnings as a first priority splits the companies in two, (3) a lack of difference (except...... for profitability) in company characteristics between the group of companies that manage cash flows versus the group of companies that manage accounting earnings as a first priority. The decision in real business on whether to manage cash flows or accounting earnings when hedging exchange rate exposures seems...

  10. Measurement of the exposure rate due to low energy x-rays emitted from video display terminals

    International Nuclear Information System (INIS)

    Campos, L.L.

    1988-01-01

    Thermoluminescent dosimeters of CaSO 4 :Dy have been used to measure the low energy x-rays emitted from Video Display Terminals (VDTs). For each terminal, three points were measured with five dosimeters at each point. The points were at distances of 5 and 50 cm in front of the screen and at 65 cm with an angle of approximately 50 0 . The last two positions approximate to positions of the lenses of the eye and the gonads respectively. A survey of 50 VDTs at a distance of 5 cm from the screen resulted in exposure rates nearly fifteen times below the exposure rate of 0.5 mR h -1 (0.129 μC kg -1 h -1 ) which is the limit recommended by the International Atomic Energy Agency (IAEA), Safety Series No. 9 (1967) Basic Safety Standards for Radiation Protection. (author)

  11. Foreign exchange risk management : how are the largest non-financial companies in Norway managing their foreign exchange rate exposure?

    OpenAIRE

    Eriksen, Krister; Wedøe, Ola

    2010-01-01

    The purpose of this thesis is to investigate how the largest non-financial companies in Norway manage their foreign exchange rate exposure. This is investigated through the use of a survey distributed to a sample the largest non-financial firms in Norway. According to our results, the largest non-financial companies in Norway have a predefined strategy for managing foreign exchange risk, which is defined by the board of directors or by the management in the organisation. The companies’ mai...

  12. Non-tectonic exposure Rates along Bedrock Fault Scarps in an active Mountain Belt of the central Apennines

    Science.gov (United States)

    Kastelic, Vanja; Burrato, Pierfrancesco; Carafa, Michele M. C.; Basili, Roberto

    2017-04-01

    The central Apennines (Italy) are a mountain chain affected by post-collisional active extension along NW-SE striking normal faults and well-documented regional-scale uplift. Moderate to strong earthquakes along the seismogenically active extensional faults are frequent in this area, thus a good knowledge on the characteristics of the hosting faults is necessary for realistic seismic hazard models. The studied bedrock fault surfaces are generally located at various heights on mountain fronts above the local base level of glacio-fluvial valleys and intermountain fluvio-lacustrine basins and are laterally confined to the extent of related mountain fronts. In order to investigate the exposure of the bedrock fault scarps from under their slope-deposit cover, a process that has often been exclusively attributed to co-seismic earthquake slip and used as proxy for tectonic slip rates and earthquake recurrence estimations, we have set up a measurement experiment along various such structures. In this experiment we measure the relative position of chosen markers on the bedrock surface and the material found directly at the contact with its hanging wall. We present the results of monitoring the contact between the exposed fault surfaces and slope deposits at 23 measurement points on 12 different faults over 3.4 year-long observation period. We detected either downward or upward movements of the slope deposit with respect to the fault surface between consecutive measurements. During the entire observation period all points, except one, registered a net downward movement in the 2.9 - 25.6 mm/yr range, resulting in the progressive exposure of the fault surface. During the monitoring period no major earthquakes occurred in the region, demonstrating the measured exposure process is disconnected from seismic activity. We do however observe a positive correlation between the higher exposure in respect to higher average temperatures. Our results indicate that the fault surface

  13. Particulate metals and organic compounds from electronic and tobacco-containing cigarettes: comparison of emission rates and secondhand exposure.

    Science.gov (United States)

    Saffari, Arian; Daher, Nancy; Ruprecht, Ario; De Marco, Cinzia; Pozzi, Paolo; Boffi, Roberto; Hamad, Samera H; Shafer, Martin M; Schauer, James J; Westerdahl, Dane; Sioutas, Constantinos

    2014-01-01

    In recent years, electronic cigarettes have gained increasing popularity as alternatives to normal (tobacco-containing) cigarettes. In the present study, particles generated by e-cigarettes and normal cigarettes have been analyzed and the degree of exposure to different chemical agents and their emission rates were quantified. Despite the 10-fold decrease in the total exposure to particulate elements in e-cigarettes compared to normal cigarettes, specific metals (e.g. Ni and Ag) still displayed a higher emission rate from e-cigarettes. Further analysis indicated that the contribution of e-liquid to the emission of these metals is rather minimal, implying that they likely originate from other components of the e-cigarette device or other indoor sources. Organic species had lower emission rates during e-cigarette consumption compared to normal cigarettes. Of particular note was the non-detectable emission of polycyclic aromatic hydrocarbons (PAHs) from e-cigarettes, while substantial emission of these species was observed from normal cigarettes. Overall, with the exception of Ni, Zn, and Ag, the consumption of e-cigarettes resulted in a remarkable decrease in secondhand exposure to all metals and organic compounds. Implementing quality control protocols on the manufacture of e-cigarettes would further minimize the emission of metals from these devices and improve their safety and associated health effects.

  14. Breast cancer incidence following low-dose rate environmental exposure: Techa River Cohort, 1956–2004

    Science.gov (United States)

    Ostroumova, E; Preston, D L; Ron, E; Krestinina, L; Davis, F G; Kossenko, M; Akleyev, A

    2008-01-01

    In the 1950s, the Mayak nuclear weapons facility in Russia discharged liquid radioactive wastes into the Techa River causing exposure of riverside residents to protracted low-to-moderate doses of radiation. Almost 10 000 women received estimated doses to the stomach of up to 0.47 Gray (Gy) (mean dose=0.04 Gy) from external γ-exposure and 137Cs incorporation. We have been following this population for cancer incidence and mortality and as in the general Russian population, we found a significant temporal trend of breast cancer incidence. A significant linear radiation dose–response relationship was observed (P=0.01) with an estimated excess relative risk per Gray (ERR/Gy) of 5.00 (95% confidence interval (CI), 0.80, 12.76). We estimated that approximately 12% of the 109 observed cases could be attributed to radiation. PMID:19002173

  15. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

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

    2010-01-01

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

  16. Estimated dose rates to members of the public from external exposure to patients with {sup 131}I thyroid treatment

    Energy Technology Data Exchange (ETDEWEB)

    Dewji, S., E-mail: dewjisa@ornl.gov; Bellamy, M.; Leggett, R.; Eckerman, K. [Oak Ridge National Laboratory, 1 Bethel Valley Road, MS-6335, Oak Ridge, Tennessee 37831 (United States); Hertel, N. [Oak Ridge National Laboratory, 1 Bethel Valley Road, MS-6335, Oak Ridge, Tennessee 37831 and Georgia Institute of Technology, 770 State Street, Atlanta, Georgia 30332-0745 (United States); Sherbini, S.; Saba, M. [United States Nuclear Regulatory Commission, Washington, DC 20555-0001 (United States)

    2015-04-15

    Purpose: Estimated dose rates that may result from exposure to patients who had been administered iodine-131 ({sup 131}I) as part of medical therapy were calculated. These effective dose rate estimates were compared with simplified assumptions under United States Nuclear Regulatory Commission Regulatory Guide 8.39, which does not consider body tissue attenuation nor time-dependent redistribution and excretion of the administered {sup 131}I. Methods: Dose rates were estimated for members of the public potentially exposed to external irradiation from patients recently treated with {sup 131}I. Tissue attenuation and iodine biokinetics were considered in the patient in a larger comprehensive effort to improve external dose rate estimates. The external dose rate estimates are based on Monte Carlo simulations using the Phantom with Movable Arms and Legs (PIMAL), previously developed by Oak Ridge National Laboratory and the United States Nuclear Regulatory Commission. PIMAL was employed to model the relative positions of the {sup 131}I patient and members of the public in three exposure scenarios: (1) traveling on a bus in a total of six seated or standing permutations, (2) two nursing home cases where a caregiver is seated at 30 cm from the patient’s bedside and a nursing home resident seated 250 cm away from the patient in an adjacent bed, and (3) two hotel cases where the patient and a guest are in adjacent rooms with beds on opposite sides of the common wall, with the patient and guest both in bed and either seated back-to-back or lying head to head. The biokinetic model predictions of the retention and distribution of {sup 131}I in the patient assumed a single voiding of urinary bladder contents that occurred during the trip at 2, 4, or 8 h after {sup 131}I administration for the public transportation cases, continuous first-order voiding for the nursing home cases, and regular periodic voiding at 4, 8, or 12 h after administration for the hotel room cases. Organ

  17. Estimated dose rates to members of the public from external exposure to patients with 131I thyroid treatment

    International Nuclear Information System (INIS)

    Dewji, S.; Bellamy, M.; Leggett, R.; Eckerman, K.; Hertel, N.; Sherbini, S.; Saba, M.

    2015-01-01

    Purpose: Estimated dose rates that may result from exposure to patients who had been administered iodine-131 ( 131 I) as part of medical therapy were calculated. These effective dose rate estimates were compared with simplified assumptions under United States Nuclear Regulatory Commission Regulatory Guide 8.39, which does not consider body tissue attenuation nor time-dependent redistribution and excretion of the administered 131 I. Methods: Dose rates were estimated for members of the public potentially exposed to external irradiation from patients recently treated with 131 I. Tissue attenuation and iodine biokinetics were considered in the patient in a larger comprehensive effort to improve external dose rate estimates. The external dose rate estimates are based on Monte Carlo simulations using the Phantom with Movable Arms and Legs (PIMAL), previously developed by Oak Ridge National Laboratory and the United States Nuclear Regulatory Commission. PIMAL was employed to model the relative positions of the 131 I patient and members of the public in three exposure scenarios: (1) traveling on a bus in a total of six seated or standing permutations, (2) two nursing home cases where a caregiver is seated at 30 cm from the patient’s bedside and a nursing home resident seated 250 cm away from the patient in an adjacent bed, and (3) two hotel cases where the patient and a guest are in adjacent rooms with beds on opposite sides of the common wall, with the patient and guest both in bed and either seated back-to-back or lying head to head. The biokinetic model predictions of the retention and distribution of 131 I in the patient assumed a single voiding of urinary bladder contents that occurred during the trip at 2, 4, or 8 h after 131 I administration for the public transportation cases, continuous first-order voiding for the nursing home cases, and regular periodic voiding at 4, 8, or 12 h after administration for the hotel room cases. Organ specific activities of 131 I

  18. X-ray equipment for dental diagnostics with a dose-rate controller influencing the exposure voltage

    International Nuclear Information System (INIS)

    Franke, K.

    1980-01-01

    If a synoptic picture is taken of teeth or jaw the X-ray tube and the film carrier with the film and a radiation detector are moving around the patient's head. The detector signal is connected to the input of the actual value of the dose-rate controller containing a scanning and stop circuit with a storing time roughly corresponding to the exposure of three teeth. After the shot the actual value of the dose rate is adjusted to the desired value, thus a constant quality of the following pictures being achieved. (RW) [de

  19. Maximum permissible dose

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

  20. Effects of Oral Exposure Duration and Gastric Energy Content on Appetite Ratings and Energy Intake in Lean Men

    Directory of Open Access Journals (Sweden)

    Anne G. M. Wijlens

    2016-01-01

    Full Text Available Studies show that longer oral exposure to food leads to earlier satiation and lowers energy intake. Moreover, higher energy content of food has been shown to lead to higher satiety. Up to now, it has not been studied systematically how oral exposure duration and gastric energy content interact in satiety regulation. Thirty-seven men (22 ± 4 years, 22 ± 2 kg/m2 participated in a randomized cross-over trial, in which we independently manipulated: (1 oral exposure duration by modified sham feeding (MSF for 1 or 8 min; and (2 energy content of gastric load (GL by a nasogastric tube: 100 kcal/500 mL or 700 kcal/500 mL. Outcome measures were appetite ratings and subsequent energy intake from an ad libitum meal. Energy intake was 35% lower after the GLs with 700 kcal than with 100kcal (p < 0.0001. All appetite ratings were lower in the 700 kcal than in the 100 kcal treatments (area under the curve (AUC; p-values ≤ 0.002; fullness was higher and prospective consumption was lower in the 8 min than in the 1 min MSF treatments (AUC; p-values ≤ 0.02. In conclusion, the current showed that a GL of 700 kcal/500 mL vs. 100 kcal/500 mL increased satiety and lowered energy intake. No additional effects of oral exposure duration could be observed, presumably due to the high contrast in energy between the manipulations. Future research should also focus on the role of oral exposure as such and not only the duration.

  1. Effects of Oral Exposure Duration and Gastric Energy Content on Appetite Ratings and Energy Intake in Lean Men.

    Science.gov (United States)

    Wijlens, Anne G M; de Graaf, Cees; Erkner, Alfrun; Mars, Monica

    2016-01-26

    Studies show that longer oral exposure to food leads to earlier satiation and lowers energy intake. Moreover, higher energy content of food has been shown to lead to higher satiety. Up to now, it has not been studied systematically how oral exposure duration and gastric energy content interact in satiety regulation. Thirty-seven men (22 ± 4 years, 22 ± 2 kg/m²) participated in a randomized cross-over trial, in which we independently manipulated: (1) oral exposure duration by modified sham feeding (MSF) for 1 or 8 min; and (2) energy content of gastric load (GL) by a nasogastric tube: 100 kcal/500 mL or 700 kcal/500 mL. Outcome measures were appetite ratings and subsequent energy intake from an ad libitum meal. Energy intake was 35% lower after the GLs with 700 kcal than with 100 kcal (p < 0.0001). All appetite ratings were lower in the 700 kcal than in the 100 kcal treatments (area under the curve (AUC); p-values ≤ 0.002); fullness was higher and prospective consumption was lower in the 8 min than in the 1 min MSF treatments (AUC; p-values ≤ 0.02). In conclusion, the current showed that a GL of 700 kcal/500 mL vs. 100 kcal/500 mL increased satiety and lowered energy intake. No additional effects of oral exposure duration could be observed, presumably due to the high contrast in energy between the manipulations. Future research should also focus on the role of oral exposure as such and not only the duration.

  2. Seasonal Variations of Indoor Microbial Exposures and Their Relation to Temperature, Relative Humidity, and Air Exchange Rate

    DEFF Research Database (Denmark)

    Frankel, Mika; Bekö, Gabriel; Timm, Michael

    2012-01-01

    with temperature, relative humidity, and air exchange rates in Danish homes. Airborne inhalable dust was sampled in five Danish homes throughout the four seasons of 1 year (indoors, n = 127; outdoors, n = 37). Measurements included culturable fungi and bacteria, endotoxin, N-acetyl-beta-d-glucosaminidase, total...... inflammatory potential, particles (0.75 to 15 μm), temperature, relative humidity, and air exchange rates. Significant seasonal variation was found for all indoor microbial exposures, excluding endotoxin. Indoor fungi peaked in summer (median, 235 CFU/m3) and were lowest in winter (median, 26 CFU/m3). Indoor...... of inhalable dust and number of particles. Temperature and air exchange rates were positively associated with fungi and N-acetyl-beta-d-glucosaminidase and negatively with bacteria and the total inflammatory potential. Although temperature, relative humidity, and air exchange rates were significantly...

  3. Time- and dose rate-related effects of internal 177Lu exposure on gene expression in mouse kidney tissue

    International Nuclear Information System (INIS)

    Schüler, Emil; Rudqvist, Nils; Parris, Toshima Z.; Langen, Britta; Spetz, Johan; Helou, Khalil; Forssell-Aronsson, Eva

    2014-01-01

    Introduction: The kidneys are the dose-limiting organs in some radionuclide therapy regimens. However, the biological impact of internal exposure from radionuclides is still not fully understood. The aim of this study was to examine the effects of dose rate and time after i.v. injection of 177 LuCl 3 on changes in transcriptional patterns in mouse kidney tissue. Methods: To investigate the effect of dose rate, female Balb/c nude mice were i.v. injected with 11, 5.6, 1.6, 0.8, 0.30, and 0 MBq of 177 LuCl 3 , and killed at 3, 6, 24, 48, 168, and 24 hours after injection, respectively. Furthermore, the effect of time after onset of exposure was analysed using mice injected with 0.26, 2.4, and 8.2 MBq of 177 LuCl 3 , and killed at 45, 90, and 140 days after injection. Global transcription patterns of irradiated kidney cortex and medulla were assessed and enriched biological processes were determined from the regulated gene sets using Gene Ontology terms. Results: The average dose rates investigated were 1.6, 0.84, 0.23, 0.11 and 0.028 mGy/min, with an absorbed dose of 0.3 Gy. At 45, 90 and 140 days, the absorbed doses were estimated to 0.3, 3, and 10 Gy. In general, the number of differentially regulated transcripts increased with time after injection, and decreased with absorbed dose for both kidney cortex and medulla. Differentially regulated transcripts were predominantly involved in metabolic and stress response-related processes dependent on dose rate, as well as transcripts associated with metabolic and cellular integrity at later time points. Conclusion: The observed transcriptional response in kidney tissue was diverse due to difference in absorbed dose, dose rate and time after exposure. Nevertheless, several transcripts were significantly regulated in all groups despite differences in exposure parameters, which may indicate potential biomarkers for exposure of kidney tissue

  4. Metabolism and Aging : Effects of Cold Exposure on Metabolic Rate, Body Composition, and Longevity in Mice

    NARCIS (Netherlands)

    Vaanholt, Lobke M.; Daan, Serge; Schubert, Kristin A.; Visser, G. Henk

    2009-01-01

    The proposition that increased energy expenditure shortens life has a long history. The rate-of-living theory ( Pearl 1928) states that life span and average mass-specific metabolic rate are inversely proportional. Originally based on interspecific allometric comparisons between species of mammals,

  5. Early growth rates and their relationships to mortalities of five breeds of chickens following exposure to acute gamma radiation stress

    International Nuclear Information System (INIS)

    Latimer, B.E.; Brisbin, I.L. Jr.

    1987-01-01

    Growth and mortality responses were recorded for 541 chicks, representing five different breeds of chickens, following acute exposures to gamma radiation stress at two days of age. Although there were no statistically significant differences in the LD50/30 of the five breeds studied, Cobb broilers showed the highest (1580R) and White Leghorn bantams the lowest (980R) levels, respectively. Other breeds studied included the standard White Leghorn, Athens Randombreds and a strain of feral bantam. Growth rates of body weights were proportionately more depressed by radiation stress than were body sizes, as measured by the lengths of the culmen, tarsus, middle toe and longest primary wing feather of all 32 day-old survivors. Among these structures, the length of the culmen seemed to be the least affected by radiation stress in all of the breeds studied. Feral bantams were able to tolerate the greatest depression in weight gain before exhibiting mortality at exposures below their LD50/30' while Cobb broilers tolerated the greatest depression of weight gain at higher exposure levels. There was a suggestion that those characteristics which were strongly selected for in the course of a particular breed's development were those which experienced the greatest proportional depressions following exposure to gamma radiation stress

  6. Maximal metabolic rates during voluntary exercise, forced exercise, and cold exposure in house mice selectively bred for high wheel-running.

    Science.gov (United States)

    Rezende, Enrico L; Chappell, Mark A; Gomes, Fernando R; Malisch, Jessica L; Garland, Theodore

    2005-06-01

    Selective breeding for high wheel-running activity has generated four lines of laboratory house mice (S lines) that run about 170% more than their control counterparts (C lines) on a daily basis, mostly because they run faster. We tested whether maximum aerobic metabolic rates (V(O2max)) have evolved in concert with wheel-running, using 48 females from generation 35. Voluntary activity and metabolic rates were measured on days 5+6 of wheel access (mimicking conditions during selection), using wheels enclosed in metabolic chambers. Following this, V(O2max) was measured twice on a motorized treadmill and twice during cold-exposure in a heliox atmosphere (HeO2). Almost all measurements, except heliox V(O2max), were significantly repeatable. After accounting for differences in body mass (S running speeds on the treadmill. However, running speeds and V(O2max) during voluntary exercise were significantly higher in S lines. Nevertheless, S mice never voluntarily achieved the V(O2max) elicited during their forced treadmill trials, suggesting that aerobic capacity per se is not limiting the evolution of even higher wheel-running speeds in these lines. Our results support the hypothesis that S mice have genetically higher motivation for wheel-running and they demonstrate that behavior can sometimes evolve independently of performance capacities. We also discuss the possible importance of domestication as a confounding factor to extrapolate results from this animal model to natural populations.

  7. Effects of pre- and postnatal polychlorinated biphenyl exposure on metabolic rate and thyroid hormones of white-footed mice

    Science.gov (United States)

    French, J.B.; Voltura, M.B.; Tomasi, T.E.

    2001-01-01

    Energy budgets have proven to be a valuable tool for predicting life history from physiological data in terrestrial vertebrates, yet these concepts have not been applied to the physiological effects of contaminants. Contaminants might affect energy budgets by imposing an additional metabolic cost or by reducing the overall amount of energy taken in; either process will reduce the energy available for production (i.e., growth or reproduction). This study examined whole animal energetic effects of polychlorinated biphenyl (PCB) exposure in white-footed mice (Peromyscus leucopus). Exposure to PCBs is known to reduce concentrations of plasma thyroid hormones, and thyroid hormones exert strong control over the rate of energy metabolism in mammals. Peromyscus leucopus that were proven breeders were fed PCBs in their food at 0, 10, and 25 ppm. Through lactation, offspring were exposed to PCB from conception and were maintained on the maternal diet to adulthood. No effects were seen on energy metabolism (O-2 consumption, measured in adulthood) or on growth, but there were large dose-dependent decreases in thyroid hormone concentrations, particularly T-4. The apparent disparity in our data between unchanged metabolic rates and 50% reductions in T-4 concentrations can be rationalized by noting that free T-3 (the fraction not bound to plasma protein) in treated mice was not significantly different from controls and that metabolism is most strongly influenced by free T-3. Overall, this study did not demonstrate any energetic consequences of PCB exposure in P. leucopus at dietary concentrations up to 25 ppm.

  8. Dealing with consumer differences in liking during repeated exposure to food; typical dynamics in rating behavior.

    Science.gov (United States)

    Dalenberg, Jelle R; Nanetti, Luca; Renken, Remco J; de Wijk, René A; Ter Horst, Gert J

    2014-01-01

    Consumers show high interindividual variability in food liking during repeated exposure. To investigate consumer liking during repeated exposure, data is often interpreted on a product level by averaging results over all consumers. However, a single product may elicit inconsistent behaviors in consumers; averaging will mix and hide possible subgroups of consumer behaviors, leading to a misinterpretation of the results. To deal with the variability in consumer liking, we propose to use clustering on data from consumer-product combinations to investigate the nature of the behavioral differences within the complete dataset. The resulting behavioral clusters can then be used to describe product acceptance. To test this approach we used two independent data sets in which young adults were repeatedly exposed to drinks and snacks, respectively. We found that five typical consumer behaviors existed in both datasets. These behaviors differed both in the average level of liking as well as its temporal dynamics. By investigating the distribution of a single product across typical consumer behaviors, we provide more precise insight in how consumers divide in subgroups based on their product liking (i.e. product modality). This work shows that taking into account and using interindividual differences can unveil information about product acceptance that would otherwise be ignored.

  9. Modeling for Dose Rate Calculation of the External Exposure to Gamma Emitters in Soil

    International Nuclear Information System (INIS)

    Allam, K. A.; El-Mongy, S. A.; El-Tahawy, M. S.; Mohsen, M. A.

    2004-01-01

    Based on the model proposed and developed in Ph.D thesis of the first author of this work, the dose rate conversion factors (absorbed dose rate in air per specific activity of soil in nGy.hr - 1 per Bq.kg - 1) are calculated 1 m above the ground for photon emitters of natural radionuclides uniformly distributed in the soil. This new and simple dose rate calculation software was used for calculation of the dose rate in air 1 m above the ground. Then the results were compared with those obtained by five different groups. Although the developed model is extremely simple, the obtained results of calculations, based on this model, show excellent agreement with those obtained by the above-mentioned models specially that one adopted by UNSCEAR. (authors)

  10. Dataset for Probabilistic estimation of residential air exchange rates for population-based exposure modeling

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset provides the city-specific air exchange rate measurements, modeled, literature-based as well as housing characteristics. This dataset is associated with...

  11. γ-ray induced chromosome aberration in rabbit peripheral blood lymphocytes irradiated in partial and whole body and decline of aberration rate with time post-exposure

    International Nuclear Information System (INIS)

    Zhang Lianzhen; Deng Zhicheng; Wang Haiyan

    1997-01-01

    Te author presents the results of study on 60 Co γ-ray induced chromosome aberration in rabbits peripheral blood lymphocytes irradiated in partial and whole body and the aberration rate decrease with the time of post-exposure. The experiments included 5 groups, it was whole-body exposure group, partial-body exposure (abdomen and pelvic cavity) group, blood irradiation group in vitro and control group respectively. Radiation dose was 3.0 Gy delivered at rate of 0.5 Gy/min. The results show that it was no significant differences between whole body and in blood irradiation group. The chromosome aberration yield in whole body exposure group was higher than that in partial-body group and in the abdomen exposure group was higher than in that in the pelvic cavity irradiation; The chromosome aberration rate decreased with the time of post-exposure in partial and whole body by γ-ray irradiation

  12. Polycyclic aromatic hydrocarbons (PAHs) skin permeation rates change with simultaneous exposures to solar ultraviolet radiation (UV-S).

    Science.gov (United States)

    Hopf, Nancy B; Spring, Philipp; Hirt-Burri, Nathalie; Jimenez, Silvia; Sutter, Benjamin; Vernez, David; Berthet, Aurelie

    2018-05-01

    Road construction workers are simultaneously exposed to two carcinogens; solar ultraviolet (UV-S) radiation and polycyclic aromatic hydrocarbons (PAHs) in bitumen emissions. The combined exposure may lead to photogenotoxicity and enhanced PAH skin permeation rates. Skin permeation rates (J) for selected PAHs in a mixture (PAH-mix) or in bitumen fume condensate (BFC) with and without UV-S co-exposures were measured with in vitro flow-through diffusion cells mounted with human viable skin and results compared. Possible biomarkers were explored. Js were greater with UV-S for naphthalene, anthracene, and pyrene in BFC (0.08-0.1 ng/cm 2 /h) compared to without (0.02-0.26 ng/cm 2 /h). This was true for anthracene, pyrene, and chrysene in the PAH-mix. Naphthalene and benzo(a)pyrene (BaP) in the PAH-mix had greater Js without (0.97-13.01 ng/cm 2 /h) compared to with UV-S (0.40-6.35 ng/cm 2 /h). Time until permeation (T lags ) in the PAH-mix were generally shorter compared to the BFC, and they ranged from 1 to 13 h. The vehicle matrix could potentially be the reason for this discrepancy as BFC contains additional not identified substances. Qualitative interpretation of p53 suggested a dose-response with UV-S, and somewhat with the co-exposures. MMP1, p65 and cKIT were not exploitable. Although not statistically different, PAHs permeate human viable skin faster with simultaneous exposures to UV. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Measurements of natural radiation exposure rates in various living environments. 4

    International Nuclear Information System (INIS)

    Matsuda, Hideharu

    1993-01-01

    The absorbed dose rates in air due to the terrestrial γ-ray and the cosmic rays were measured on five subway lines in Nagoya City and in the underground shopping malls in Sakae and The Nagoya Station areas as the basic data to estimate the population dose. The mean values of the γ-ray dose rates were 36.3 ± 7.3 nGy/h and 56.1 ± 6.4 nGy/h in the subway lines and in the underground shopping malls, respectively. It is inferred that the variation in the γ-ray dose rate is mainly due to the difference in the concentration of natural radionuclides contained in the building materials of the subway tunnels and of the ceilings of the underground malls. The cosmic ray dose rates lay in the range of ca. 1/2-1/3 of the ground level value due to the shielding effect of the materials covering over the subway tunnels or the underground shopping malls. The mean value of the total dose rate for the gamma and the cosmic rays in the subway lines was about 50% and that in the underground shopping malls was about 20% lower than the value (87.3 nGy/h) on the ground in Nagoya City. (author)

  14. Short-term association between personal exposure to noise and heart rate variability: The RECORD MultiSensor Study.

    Science.gov (United States)

    El Aarbaoui, Tarik; Méline, Julie; Brondeel, Ruben; Chaix, Basile

    2017-12-01

    Studies revealed long-term associations between noise exposure and cardiovascular health, but the underlying short-term mechanisms remain uncertain. To explore the concomitant and lagged short-term associations between personal exposure to noise and heart rate variability (HRV) in a real life setting in the Île-de-France region. The RECORD MultiSensor Study collected between July 2014 and June 2015 noise and heart rate data for 75 participants, aged 34-74 years, in their living environments for 7 days using a personal dosimeter and electrocardiography (ECG) sensor on the chest. HRV parameters and noise levels were calculated for 5-min windows. Short-term relationships between noise level and log-transformed HRV parameters were assessed using mixed effects models with a random intercept for participants and a temporal autocorrelation structure, adjusted for heart rate, physical activity (accelerometry), and short-term trends. An increase by one dB(A) of A-weighted equivalent sound pressure level (Leq) was associated with a 0.97% concomitant increase of the Standard deviation of normal to normal intervals (SDNN) (95% CI: 0.92, 1.02), of 2.08% of the Low frequency band power (LF) (95% CI: 1.97, 2.18), of 1.30% of the High frequency band power (HF) (95% CI: 1.17, 1.43), and of 1.16% of the LF/HF ratio (95% CI: 1.10, 1.23). The analysis of lagged exposures to noise adjusted for the concomitant exposure illustrates the dynamic of recovery of the autonomic nervous system. Non-linear associations were documented with all HRV parameters with the exception of HF. Piecewise regression revealed that the association was almost 6 times stronger below than above 65 Leq dB(A) for the SDNN and LF/HF ratio. Personal noise exposure was found to be related to a concomitant increase of the overall HRV, with evidence of imbalance of the autonomic nervous system towards sympathetic activity, a pathway to increased cardiovascular morbidity and mortality. Copyright © 2017 Elsevier Ltd

  15. Estimation of production rates for in-situ cosmogenic isotopes and application to surface exposure dating: certitudes and uncertainties

    International Nuclear Information System (INIS)

    Graham, I.J.

    1996-01-01

    Cosmogenic nuclides, produced in-situ in rocks by the action of cosmic rays on target nuclei, are increasingly being employed by earth scientists in a wide variety of applications. For example, surface exposure dating is used to determine erosion rates, the age of debris flows, alluvial fans, volcanic eruptions, meteoritic impact craters, and glacial deposits, and the timing of recent movement along faults and tectonic uplift. The technique can thus play a vital role in the study of potential hazards from geological processes, by establishing recurrence intervals between them, and establish chronologies and periodicities for major paleoclimatic events. Before surface exposure dating methods using cosmogenic isotopes can be applied even more widely, production rates of the main nuclides of interest must be better known, and their temporal and spatial variabilities determined. This paper summarises the present state of knowledge on production rates of the currently most useful nuclides ( 10 Be, 26 Al, 36 Cl, 14 C, 3 He and 21 Ne), discusses the main areas of concern, and makes suggestions for future improvement. (author). 83 refs., 7 tabs., 11 figs

  16. Discussion about the range of natural radiation exposure rate found in dwelling-houses in the Federal Republic of Germany and in Poland

    International Nuclear Information System (INIS)

    Schmier, H.; Pensko, J.; Wicke, A.

    1982-01-01

    In this paper the range of natural radiation exposure rate found in dwelling-houses is discussed. The source of this exposure are natural radionuclides 40 K, 226 Ra, 232 Th and their decay products widely distributed in soil and in building materials. The resulting whole body dose equivalent rate of gamma radiation is compared to the effective dose equivalent rate of alpha radiation originating from 222 Rn diffusing out of building materials and decaying to alpha emitting short living daughters. (Author) [de

  17. No impact of repeated extinction exposures on operant responding maintained by different reinforcer rates.

    Science.gov (United States)

    Bai, John Y H; Podlesnik, Christopher A

    2017-05-01

    Greater rates of intermittent reinforcement in the presence of discriminative stimuli generally produce greater resistance to extinction, consistent with predictions of behavioral momentum theory. Other studies reveal more rapid extinction with higher rates of reinforcers - the partial reinforcement extinction effect. Further, repeated extinction often produces more rapid decreases in operant responding due to learning a discrimination between training and extinction contingencies. The present study examined extinction repeatedly with training with different rates of intermittent reinforcement in a multiple schedule. We assessed whether repeated extinction would reverse the pattern of greater resistance to extinction with greater reinforcer rates. Counter to this prediction, resistance to extinction was consistently greater across twelve assessments of training followed by six successive sessions of extinction. Moreover, patterns of responding during extinction resembled those observed during satiation tests, which should not alter discrimination processes with repeated testing. These findings join others suggesting operant responding in extinction can be durable across repeated tests. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Survival rate of honeybee (Apis mellifera) workers after exposure to sublethal concentrations of imidacloprid

    NARCIS (Netherlands)

    Blacquiere, T.

    2010-01-01

    Imidacloprid is a commonly used systemic insecticide which can induce several sublethal effects. Previous research has not shown any increased mortality in bees that were fed with sublethal doses. However, there is very little research conducted with the focus on survival rate of honeybees in the

  19. Exposure testing of fasteners in preservative treated wood : gravimetric corrosion rates and corrosion product analyses

    Science.gov (United States)

    Samuel L. Zelinka; Rebecca J. Sichel; Donald S. Stone

    2010-01-01

    Research was conducted to determine the corrosion rates of metals in preservative treated wood and also understand the mechanism of metal corrosion in treated wood. Steel and hot-dip galvanized steel fasteners were embedded in wood treated with one of six preservative treatments and exposed to 27oC at 100% relative humidity for 1 year. The...

  20. Improving HIV post-exposure prophylaxis rates after pediatric acute sexual assault.

    Science.gov (United States)

    Schilling, Samantha; Deutsch, Stephanie A; Gieseker, Rebecca; Molnar, Jennifer; Lavelle, Jane M; Scribano, Philip V

    2017-07-01

    The purpose of our study was to increase the rate of children with appropriate HIV-PEP regimens among those diagnosed with sexual assault in The Children's Hospital of Philadelphia Emergency Department (ED). The outcome measure was the percent of patients receiving correct HIV-PEP. We retrospectively reviewed 97 charts over 31 months to define the baseline rate of children receiving appropriate HIV-PEP regimens (pre QI-implementation period: 2/2012-8/2014). Among children in which HIV-PEP was indicated following sexual assault, 40% received the recommended 28-day course. Root cause analysis indicated prescribing errors accounted for 87% of patients not receiving appropriate HIV-PEP. Process drivers included standardizing care coordination follow-up calls to elicit specific information about HIV-PEP, ED educational initiatives targeted at HIV-PEP prescribing, revision of the clinical pathway to specify indicated duration of HIV-PEP, and revision of the order set to auto-populate the number of days for the HIV-PEP prescription. During the QI-implementation period (9/2014-4/2015), the rate of appropriate HIV-PEP increased to 64% (median 60%) and the average number of days between incorrect HIV-PEP regimens was 24.5. Post QI-implementation (5/2015-3/2016), the rate of appropriate HIV-PEP increased to 84% (median 100%) and the average number of days between incorrect HIV-PEP regimens increased to 78.4. A multifaceted quality improvement process improved the rate of receipt of appropriate HIV-PEP regimens for pediatric victims of sexual assault. Decision support tools are instrumental in sustaining ideal care delivery, but require ongoing evaluation and improvement in order to remain optimally effective. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. In-situ buildup of cosmogenic isotopes at the earth`s surface: measurement of erosion rates and exposure times

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, L K; Allan, G L; Stone, J O.H.; Evans, J M; Cresswell, R G; Ophel, T R [Australian National Univ., Canberra, ACT (Australia)

    1994-12-31

    Cosmic rays produce a number of nuclides in rocks that can be used to determine the geomorphic history of surfaces. The most useful are the radioactive isotopes {sup 10}Be (t{sub 1/2} = 1.5Ma), {sup 26}Al (0.7Ma) and {sup 36}Cl (0.3Ma). Within the top 2m of the surface, these are produced principally by fast neutrons. At greater depths, production is dominated by the capture of negative muons. Measurements of a single nuclide produced in situ can be used to determine total exposure times or erosion rates. The use of multiple nuclides with different half-lives makes it possible to determine more complex histories, such as exposures interrupted by periods of burial. At the ANU, all three of the isotopes above are being used to study a variety of problems in geomorphology and paleoclimatology, although to date, most of the work has concentrated on {sup 36}Cl. The accumulation of cosmogenic {sup 36}Cl in calcite (CaCO{sub 3}) provides a means of measuring erosion rates on limestone surfaces. Sensitivity is achieved over a wide range of erosion rates due to the high production rate of {sup 36}Cl in calcite (typically greater than 30 atoms/g/yr) and a detection limit of ca. 5000 atoms/g attainable with the ANU AMS system. The method is simplified by the predominance of Ca reactions (principally spallation) over other sources of {sup 36}Cl in calcite, and the ease of sample preparation. This presentation discuss the results of measurements of {sup 36}Cl in calcite from limestone samples from Australia and Papua New Guinea. Erosion rates derived from these measurements range from 3 microns per year (Australia) to over 200 microns per year in the New Guinea highlands. 3 refs.

  2. In-situ buildup of cosmogenic isotopes at the earth's surface: measurement of erosion rates and exposure times

    International Nuclear Information System (INIS)

    Fifield, L.K.; Allan, G.L.; Stone, J.O.H.; Evans, J.M.; Cresswell, R.G.; Ophel, T.R.

    1993-01-01

    Cosmic rays produce a number of nuclides in rocks that can be used to determine the geomorphic history of surfaces. The most useful are the radioactive isotopes 10 Be (t 1/2 = 1.5Ma), 26 Al (0.7Ma) and 36 Cl (0.3Ma). Within the top 2m of the surface, these are produced principally by fast neutrons. At greater depths, production is dominated by the capture of negative muons. Measurements of a single nuclide produced in situ can be used to determine total exposure times or erosion rates. The use of multiple nuclides with different half-lives makes it possible to determine more complex histories, such as exposures interrupted by periods of burial. At the ANU, all three of the isotopes above are being used to study a variety of problems in geomorphology and paleoclimatology, although to date, most of the work has concentrated on 36 Cl. The accumulation of cosmogenic 36 Cl in calcite (CaCO 3 ) provides a means of measuring erosion rates on limestone surfaces. Sensitivity is achieved over a wide range of erosion rates due to the high production rate of 36 Cl in calcite (typically greater than 30 atoms/g/yr) and a detection limit of ca. 5000 atoms/g attainable with the ANU AMS system. The method is simplified by the predominance of Ca reactions (principally spallation) over other sources of 36 Cl in calcite, and the ease of sample preparation. This presentation discuss the results of measurements of 36 Cl in calcite from limestone samples from Australia and Papua New Guinea. Erosion rates derived from these measurements range from 3 microns per year (Australia) to over 200 microns per year in the New Guinea highlands. 3 refs

  3. In-situ buildup of cosmogenic isotopes at the earth`s surface: measurement of erosion rates and exposure times

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, L.K.; Allan, G.L.; Stone, J.O.H.; Evans, J.M.; Cresswell, R.G.; Ophel, T.R. [Australian National Univ., Canberra, ACT (Australia)

    1993-12-31

    Cosmic rays produce a number of nuclides in rocks that can be used to determine the geomorphic history of surfaces. The most useful are the radioactive isotopes {sup 10}Be (t{sub 1/2} = 1.5Ma), {sup 26}Al (0.7Ma) and {sup 36}Cl (0.3Ma). Within the top 2m of the surface, these are produced principally by fast neutrons. At greater depths, production is dominated by the capture of negative muons. Measurements of a single nuclide produced in situ can be used to determine total exposure times or erosion rates. The use of multiple nuclides with different half-lives makes it possible to determine more complex histories, such as exposures interrupted by periods of burial. At the ANU, all three of the isotopes above are being used to study a variety of problems in geomorphology and paleoclimatology, although to date, most of the work has concentrated on {sup 36}Cl. The accumulation of cosmogenic {sup 36}Cl in calcite (CaCO{sub 3}) provides a means of measuring erosion rates on limestone surfaces. Sensitivity is achieved over a wide range of erosion rates due to the high production rate of {sup 36}Cl in calcite (typically greater than 30 atoms/g/yr) and a detection limit of ca. 5000 atoms/g attainable with the ANU AMS system. The method is simplified by the predominance of Ca reactions (principally spallation) over other sources of {sup 36}Cl in calcite, and the ease of sample preparation. This presentation discuss the results of measurements of {sup 36}Cl in calcite from limestone samples from Australia and Papua New Guinea. Erosion rates derived from these measurements range from 3 microns per year (Australia) to over 200 microns per year in the New Guinea highlands. 3 refs.

  4. Monte Carlo calculation of dose rate conversion factors for external exposure to photon emitters in soil

    CERN Document Server

    Clouvas, A; Antonopoulos-Domis, M; Silva, J

    2000-01-01

    The dose rate conversion factors D/sub CF/ (absorbed dose rate in air per unit activity per unit of soil mass, nGy h/sup -1/ per Bq kg/sup -1/) are calculated 1 m above ground for photon emitters of natural radionuclides uniformly distributed in the soil. Three Monte Carlo codes are used: 1) The MCNP code of Los Alamos; 2) The GEANT code of CERN; and 3) a Monte Carlo code developed in the Nuclear Technology Laboratory of the Aristotle University of Thessaloniki. The accuracy of the Monte Carlo results is tested by the comparison of the unscattered flux obtained by the three Monte Carlo codes with an independent straightforward calculation. All codes and particularly the MCNP calculate accurately the absorbed dose rate in air due to the unscattered radiation. For the total radiation (unscattered plus scattered) the D/sub CF/ values calculated from the three codes are in very good agreement between them. The comparison between these results and the results deduced previously by other authors indicates a good ag...

  5. Exposure testing of fasteners in preservative treated wood: Gravimetric corrosion rates and corrosion product analyses

    Energy Technology Data Exchange (ETDEWEB)

    Zelinka, Samuel L., E-mail: szelinka@fs.fed.u [USDA Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI 53726 (United States); Sichel, Rebecca J. [College of Engineering, University of Wisconsin, Madison, WI 53706 (United States); Stone, Donald S. [Department of Materials Science and Engineering, College of Engineering, University of Wisconsin, Madison, WI 53706 (United States)

    2010-12-15

    Research highlights: {yields} The composition of the corrosion products was similar for the nail head and shank. {yields} Reduced copper was not detected on any of the fasteners. {yields} Measured corrosion rates were between 1 and 35 {mu}m year{sup -1}. - Abstract: Research was conducted to determine the corrosion rates of metals in preservative treated wood and also understand the mechanism of metal corrosion in treated wood. Steel and hot-dip galvanized steel fasteners were embedded in wood treated with one of six preservative treatments and exposed to 27 {sup o}C at 100% relative humidity for 1 year. The corrosion rate was determined gravimetrically and the corrosion products were analyzed with scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. Although the accepted mechanism of corrosion in treated wood involves the reduction of cupric ions from the wood preservative, no reduced copper was found on the corrosion surfaces. The galvanized corrosion products contained sulfates, whereas the steel corrosion products consisted of iron oxides and hydroxides. The possible implications and limitations of this research on fasteners used in building applications are discussed.

  6. The relationship between specific absorption rate and temperature elevation in anatomically based human body models for plane wave exposure from 30 MHz to 6 GHz.

    Science.gov (United States)

    Hirata, Akimasa; Laakso, Ilkka; Oizumi, Takuya; Hanatani, Ryuto; Chan, Kwok Hung; Wiart, Joe

    2013-02-21

    According to the international safety guidelines/standard, the whole-body-averaged specific absorption rate (Poljak et al 2003 IEEE Trans. Electromagn. Compat. 45 141-5) and the peak spatial average SAR are used as metrics for human protection from whole-body and localized exposures, respectively. The IEEE standard (IEEE 2006 IEEE C95.1) indicates that the upper boundary frequency, over which the whole-body-averaged SAR is deemed to be the basic restriction, has been reduced from 6 to 3 GHz, because radio-wave energy is absorbed around the body surface when the frequency is increased. However, no quantitative discussion has been provided to support this description especially from the standpoint of temperature elevation. It is of interest to investigate the maximum temperature elevation in addition to the core temperature even for a whole-body exposure. In the present study, using anatomically based human models, we computed the SAR and the temperature elevation for a plane-wave exposure from 30 MHz to 6 GHz, taking into account the thermoregulatory response. As the primary result, we found that the ratio of the core temperature elevation to the whole-body-averaged SAR is almost frequency independent for frequencies below a few gigahertz; the ratio decreases above this frequency. At frequencies higher than a few gigahertz, core temperature elevation for the same whole-body averaged SAR becomes lower due to heat convection from the skin to air. This lower core temperature elevation is attributable to skin temperature elevation caused by the power absorption around the body surface. Then, core temperature elevation even for whole-body averaged SAR of 4 W kg(-1) with the duration of 1 h was at most 0.8 °C, which is smaller than a threshold considered in the safety guidelines/standard. Further, the peak 10 g averaged SAR is correlated with the maximum body temperature elevations without extremities and pinna over the frequencies considered. These findings

  7. Dose-rate conversion factors for external exposure to photon and electron radiation from radionuclides occurring in routine releases from nuclear fuel cycle facilities

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1980-01-01

    Dose-rate conversion factors for external exposure to photon and electron radiation are calculated for 240 radionuclides of potential importance in routine releases from nuclear fuel cycle facilities. Exposure modes considered are immersion in contaminated air, immersion in contaminated water, and irradiation from a contaminated ground surface. For each exposure mode, dose-rate conversion factors for photons and electrons are calculated for tissue-equivalent material at the body surface of an exposed individual. Dose-rate conversion factors for photons only are calculated for 22 body organs. (author)

  8. Comparative response of dogs and monkeys to sublethal acute and continuous low dose-rate gamma-ray exposure

    International Nuclear Information System (INIS)

    Spalding, J.F.; Holland, L.M.; Johnson, O.S.; LaBauve, P.M.; London, J.E.; Prine, J.R.; Vigil, E.A.

    1977-02-01

    Monkeys (Macaca mulatta) and dogs (beagle) were given thirteen 100-rad gamma-ray doses at 28-day intervals. The comparative response (injury and recovery) of the hematopoietic system of the two species was observed at 7-day intervals during the exposure regime. At 84 days after the thirteenth gamma-ray dose, the 1300-rad conditioned and control dogs and monkeys were challenged continuously with 35 R/day until death to determine the amount of radiation-induced injury remaining in conditioned animals as a reduction in mean survival time. Dogs (50 percent) and monkeys (8 percent) died from injury incurred during the conditioning exposures. Thus, the comparative response of dogs and monkeys to dose protraction by acute dose fractionation was similar to what might be expected from a single acute dose. Mean survival times for nonconditioned dogs and monkeys during continuous exposure at 35 R/day were the same (approximately 1400 h). Thus, hematopoietic response of the two species by this method of dose protraction was not significantly different. Mean survival times of conditioned dogs and monkeys during the continuous 35 R/day gamma-ray challenge exposure were greater than for their control counterparts. Thus, the long-term radiation-induced injury was not measurable by this method. Conditioning doses of more than four times the acute LD 50 - 30 in dogs and approximately two times that of monkeys served only to increase both mean survival time and variance in a gamma-ray stress environment with a dose rate of 35 R/day

  9. Automatic exposure control at single- and dual-heartbeat CTCA on a 320-MDCT volume scanner: effect of heart rate, exposure phase window setting, and reconstruction algorithm.

    Science.gov (United States)

    Funama, Yoshinori; Utsunomiya, Daisuke; Taguchi, Katsuyuki; Oda, Seitaro; Shimonobo, Toshiaki; Yamashita, Yasuyuki

    2014-05-01

    To investigate whether electrocardiogram (ECG)-gated single- and dual-heartbeat computed tomography coronary angiography (CTCA) with automatic exposure control (AEC) yields images with uniform image noise at reduced radiation doses. Using an anthropomorphic chest CT phantom we performed prospectively ECG-gated single- and dual-heartbeat CTCA on a second-generation 320-multidetector CT volume scanner. The exposure phase window was set at 75%, 70-80%, 40-80%, and 0-100% and the heart rate at 60 or 80 or corr80 bpm; images were reconstructed with filtered back projection (FBP) or iterative reconstruction (IR, adaptive iterative dose reduction 3D). We applied AEC and set the image noise level to 20 or 25 HU. For each technique we determined the image noise and the radiation dose to the phantom center. With half-scan reconstruction at 60 bpm, a 70-80% phase window- and a 20-HU standard deviation (SD) setting, the imagenoise level and -variation along the z axis manifested similar curves with FBP and IR. With half-scan reconstruction, the radiation dose to the phantom center with 70-80% phase window was 18.89 and 12.34 mGy for FBP and 4.61 and 3.10 mGy for IR at an SD setting SD of 20 and 25 HU, respectively. At 80 bpm with two-segment reconstruction the dose was approximately twice that of 60 bpm at both SD settings. However, increasing radiation dose at corr80 bpm was suppressed to 1.39 times compared to 60 bpm. AEC at ECG-gated single- and dual-heartbeat CTCA controls the image noise at different radiation dose. Copyright © 2013 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  10. Effect of continuous exposure to very low dose rates of gamma rays on life span and neoplasia in mice

    International Nuclear Information System (INIS)

    Tanaka, I.B. III; Tanaka, Satoshi; Ichinohe, Kazuaki; Matsumoto, Tsuneya; Otsu, Hiroshi; Oghiso, Yoichi; Sato, Fumiaki; Matsushita, Satoru

    2008-01-01

    Late effects of continuous exposure to ionizing radiation are potential hazards to workers in radiation facilities as well as to the general public. In the recent years, low-dose-rate and low-dose effects have become a serious concern. Using a total of 4,000 mice, we studied the late biological effects of chronic exposure to low-dose-rate radiation on life span and neoplasia. Two thousand male and 2000 female 8-week-old specific pathogen free (SPF) B6C3F1 mice were randomly divided into 4 groups, one non-irradiated (control) and three irradiated. The irradiated groups were exposed to 137 Cs gamma rays at dose-rates of 21, 1.1 and 0.05 mGy day -1 for approximately 400 days with total doses equivalent to 8000, 400 and 20 mGy, respectively. All mice were kept under SPF conditions until natural death and pathological examination was performed to determine the cause of death. Statistical analyses showed that the life spans of mice of both sexes irradiated with 21 mGy day -1 (P -1 (P 86.7% of all deaths. Compared to the non-irradiated controls, incidences of lethal neoplasms were significantly increased for myeloid leukaemia and hemangiosarcoma in males, soft tissue neoplasms and malignant granulosa cell tumors in females exposed to 21 mGy day -1 . The number of multiple primary neoplasms per mouse was significantly increased in mice irradiated at 21 mGy day -1 . Our results suggest that life shortening in mice continuously exposed to low dose-rate gamma rays is due to early death from a variety of neoplasms and not from increased incidence of specific lethal neoplasms. (author)

  11. Assessment of natural radiation exposure and radon exhalation rates from the soil of Islamabad District of Pakistan

    International Nuclear Information System (INIS)

    Mujahid, S.A.

    2007-01-01

    Complete text of publication follows. The earth's crust is a main source of natural radionuclides in soils and rocks. The specific levels of background gamma radiation depend upon the geological composition of each lithologically separated area, and the content of the rock from which the soils originate the radioactive elements of 226Rn, 232Th and 40K. These naturally occurring radionuclides of terrestrial origin in soil can be a source of external radiation exposure through the gamma ray emission whereas internal exposure occurs through the inhalation of radon gas. The measurements of natural radioactivity and the assessment of radiological hazards in the soil samples of Islamabad district of Pakistan have been carried out using High Purity Germanium (HPGe) detector. The radon exhalation rates from these samples have also been estimated employing the 'closed-can' technique of passive dosimeters. The measured activities of 226Ra, 232Th and 40K were found in the range 14 - 30, 18 - 40 and 301 - 655 Bq.kg-1. The annual effective dose was calculated in the range 0.15 - 0.31 mSv. The values of external and internal hazard indices were less than 1. The radon exhalation rates these areas were found in the range 200 - 345 mBq.m-2h-1.

  12. The rate of DNA synthesis in normal human and ataxia telangiectasia cells after exposure to X-irradiation

    International Nuclear Information System (INIS)

    Wit, J. de; Bootsma, D.; Jaspers, N.G.J.; Rijksverdedigingsorganisatie TNO, Rijswijk

    1981-01-01

    The rate of DNA synthesis was studied in normal cell strains and in strains from patients suffering from the inherited disorder ataxia telangiectasia (AT). After exposure to relatively low doses of oxic X-rays (0- 4 krad) DNA synthesis was depressed in AT cell strains to a significantly lesser extent than in normal cells. This response was observed in both an excision-deficient and an excision-proficient strain. In contrast, there was no difference in DNA-synthesis inhibition between AT and normal cells after UV exposure. After X-irradiation of cells from patients with xeroderma pigmentosum, both complementation group A and XP variants, the observed rate of DNA synthesis was equal to that in normal cells. An exception was the strain XP3BR which has been shown to be X-ray-sensitive. This strain exhibited diminished DNA synthesis inhibition after X-ray doses below 1 krad. These data suggest a relationship between hypersensitivity to X-rays and diminished depression of DNA synthesis. (orig.)

  13. The rate of X-ray-induced DNA double-strand break repair in the embryonic mouse brain is unaffected by exposure to 50 Hz magnetic fields.

    Science.gov (United States)

    Woodbine, Lisa; Haines, Jackie; Coster, Margaret; Barazzuol, Lara; Ainsbury, Elizabeth; Sienkiewicz, Zenon; Jeggo, Penny

    2015-06-01

    Following in utero exposure to low dose radiation (10-200 mGy), we recently observed a linear induction of DNA double-strand breaks (DSB) and activation of apoptosis in the embryonic neuronal stem/progenitor cell compartment. No significant induction of DSB or apoptosis was observed following exposure to magnetic fields (MF). In the present study, we exploited this in vivo system to examine whether exposure to MF before and after exposure to 100 mGy X-rays impacts upon DSB repair rates. 53BP1 foci were quantified following combined exposure to radiation and MF in the embryonic neuronal stem/progenitor cell compartment. Embryos were exposed in utero to 50 Hz MF at 300 μT for 3 h before and up to 9 h after exposure to 100 mGy X-rays. Controls included embryos exposed to MF or X-rays alone plus sham exposures. Exposure to MF before and after 100 mGy X-rays did not impact upon the rate of DSB repair in the embryonic neuronal stem cell compartment compared to repair rates following radiation exposure alone. We conclude that in this sensitive system MF do not exert any significant level of DNA damage and do not impede the repair of X-ray induced damage.

  14. Germline mutation rates in mice following in utero exposure to diesel exhaust particles by maternal inhalation

    DEFF Research Database (Denmark)

    Ritz, Caitlin; Ruminski, Wojciech; Hougaard, Karin S.

    2011-01-01

    (PAPs) from industrial environments cause DNA damage and mutations in the sperm of adult male mice. Effects on the female and male germline during critical stages of development (in utero) are unknown. In mice, previous studies have shown that expanded simple tandem repeat (ESTR) loci exhibit high rates......The induction of inherited DNA sequence mutations arising in the germline (i.e., sperm or egg) of mice exposed in utero to diesel exhaust particles (DEPs) via maternal inhalation compared to unexposed controls was investigated in this study. Previous work has shown that particulate air pollutants...... of spontaneous mutation, making this endpoint a valuable tool for studying inherited mutation and genomic instability. In the present study, pregnant C57Bl/6 mice were exposed to 19mg/m3 DEP from gestational day 7 through 19, alongside air exposed controls. Male and female F1 offspring were raised to maturity...

  15. Rates of fetal polydrug exposures in methadone-maintained pregnancies from a high-risk population.

    Directory of Open Access Journals (Sweden)

    Kaitlyn Delano

    Full Text Available Methadone maintenance treatment (MMT is the standard of care during pregnancy for opioid-dependency, showing efficacy in improving prenatal care and reducing risk of relapse. By design, however, MMT is only intended to prevent withdrawal thus facilitating cognitive behavioural interventions. In order to maximize the benefits of MMT, it is essential that methadone is both properly prescribed and that additional addiction treatment is concurrently administered. This study aims to determine the effectiveness of MMT engagement in high-risk pregnant women in reducing polydrug use by objective laboratory examination of neonatal meconium.Over a 29-month period, the Motherisk Laboratory at the Hospital for Sick Children in Toronto analyzed meconium samples as per request by social services and hospitals for drugs of abuse.Of the 904 meconium samples received, 273 were tested for methadone with 164 positive and 109 negative for methadone. Almost half of the methadone positive samples (46.34% were also positive for at least one other opioid compound, which did not differ statistically from the methadone-negative control samples (46.79%; Chi square test, p=0.94. No differences were found between the methadone positive and negative groups in rates of concurrent amphetamines, cocaine, cannabis, and alcohol use indicating a similar risk of polydrug use between pregnant women taking or not taking methadone in this population.The high rates of additional opioid and other drug use in the MMT group, suggest that MMT is failing this population of patients. It is possible that methadone doses during pregnancy are not appropriately adjusted for changes in pharmacokinetic parameters (e.g. blood volume, renal function during the second and third trimesters. This may result in sub-therapeutic dosing creating withdrawal symptoms leading to additional substance use. Alternatively, these results may be demonstrating a substantial lack in delivery of addiction support

  16. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  17. Predictive analysis of the radiation exposure for the primary cooling system of the rated power operation of MONJU

    International Nuclear Information System (INIS)

    Matuo, Youichirou; Miyahara, Shinya; Hasegawa, Masanori; Maegawa, Yoshiharu

    2011-01-01

    Radioactive corrosion products (CP) are main source of personal radiation exposure during maintenance without fuel-failure accident in the Liquid-Metal Fast Breeder Reactor (LMFBR) plants. In order to establish the techniques of radiation dose estimation for personnel, program system 'DORE' has been developed. The DORE system is constructed by PSYCHE code and QAD code system. The density of each deposited CP of primary coolant system in MONJU was estimated by using the PSYCHE. Moreover, the QAD-CGGP2R code is applied to dose rate calculations for the primary coolant system in MONJU. The dose rate around primary piping system was visualized using AVS software. The predicted values were estimated to be saturated at 2-3 mSv/h in twenty years after the start of operation, and the dose rate reaches 4 mSv/h in domains near the IHX and the cold-leg piping. It has been assumed that the main radiation source is 54 Mn in the IHX, primary pump and cold-leg piping region. On the other hand, it was indicated that the contribution to dose rate of the 60 Co accounted for approximately 23% in the hot-leg piping region. (author)

  18. Results of calculations of external gamma radiation exposure rates from fallout and the related radionuclide compositions. Operation Tumbler-Snapper, 1952

    International Nuclear Information System (INIS)

    Hicks, H.G.

    1981-07-01

    This report presents data on calculated gamma radiation exposure rates and ground deposition of related radionuclides resulting from Events that deposited detectable radioactivity outside the Nevada Test Site complex

  19. Maximum Quantum Entropy Method

    OpenAIRE

    Sim, Jae-Hoon; Han, Myung Joon

    2018-01-01

    Maximum entropy method for analytic continuation is extended by introducing quantum relative entropy. This new method is formulated in terms of matrix-valued functions and therefore invariant under arbitrary unitary transformation of input matrix. As a result, the continuation of off-diagonal elements becomes straightforward. Without introducing any further ambiguity, the Bayesian probabilistic interpretation is maintained just as in the conventional maximum entropy method. The applications o...

  20. Maximum power demand cost

    International Nuclear Information System (INIS)

    Biondi, L.

    1998-01-01

    The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some [it

  1. Maximum Entropy in Drug Discovery

    Directory of Open Access Journals (Sweden)

    Chih-Yuan Tseng

    2014-07-01

    Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

  2. Quantitative extraction of the bedrock exposure rate based on unmanned aerial vehicle data and Landsat-8 OLI image in a karst environment

    Science.gov (United States)

    Wang, Hongyan; Li, Qiangzi; Du, Xin; Zhao, Longcai

    2017-12-01

    In the karst regions of southwest China, rocky desertification is one of the most serious problems in land degradation. The bedrock exposure rate is an important index to assess the degree of rocky desertification in karst regions. Because of the inherent merits of macro-scale, frequency, efficiency, and synthesis, remote sensing is a promising method to monitor and assess karst rocky desertification on a large scale. However, actual measurement of the bedrock exposure rate is difficult and existing remote-sensing methods cannot directly be exploited to extract the bedrock exposure rate owing to the high complexity and heterogeneity of karst environments. Therefore, using unmanned aerial vehicle (UAV) and Landsat-8 Operational Land Imager (OLI) data for Xingren County, Guizhou Province, quantitative extraction of the bedrock exposure rate based on multi-scale remote-sensing data was developed. Firstly, we used an object-oriented method to carry out accurate classification of UAVimages. From the results of rock extraction, the bedrock exposure rate was calculated at the 30 m grid scale. Parts of the calculated samples were used as training data; other data were used for model validation. Secondly, in each grid the band reflectivity of Landsat-8 OLI data was extracted and a variety of rock and vegetation indexes (e.g., NDVI and SAVI) were calculated. Finally, a network model was established to extract the bedrock exposure rate. The correlation coefficient of the network model was 0.855, that of the validation model was 0.677 and the root mean square error of the validation model was 0.073. This method is valuable for wide-scale estimation of bedrock exposure rate in karst environments. Using the quantitative inversion model, a distribution map of the bedrock exposure rate in Xingren County was obtained.

  3. The Exposure of Mortgage Borrowers to Interest Rate Risk, Income Risk and House Price Risk – Evidence from Swiss Loan Application Data

    OpenAIRE

    Guin, Benjamin; Brown, Martin

    2015-01-01

    We study the exposure of mortgage borrowers in Switzerland to interest rate, income and house price risks and examine how the households’ choice of risky mortgages is related to individual interest rate expectations and risk-aversion. Our analysis is based on a unique data set of household mortgage applications from September 2012 until January 2014. Our assessment of risk exposure among mortgage borrowers in Switzerland is highly sensitive to the underlying assumptions on mortgage costs, hou...

  4. Increased opercular rates of pink salmon (Oncorhynchus gorbuscha) fry after exposure to the eater-soluble fraction of Prudhoe Bay crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R E [Chico State Univ., CA; Rice, S D

    1976-01-01

    The opercular rates of pink salmon (Oncorhynchus gorbuscha) fry were measured during 24-h exposure to sublethal concentrations of the water-soluble fraction of Prudhoe Bay crude oil. Opercular rates increased significantly for as long as 9 and 12 h after exposure to water-soluble fractions prepared from oil-water solutions of 2.83 and 3.46 ppM. The increases in rates were proportional to increases in dose. Recording changes in opercular rates appears to be a suitable method for detecting sublethal physiological effects of stress, because the observed changes occurred at approximately 20 percent of the 96 h-LC50.

  5. Specific absorption rate variation in a brain phantom due to exposure by a 3G mobile phone: problems in dosimetry.

    Science.gov (United States)

    Behari, J; Nirala, Jay Prakash

    2013-12-01

    A specific absorption rate (SAR) measurements system has been developed for compliance testing of personal mobile phone in a brain phantom material contained in a Perspex box. The volume of the box has been chosen corresponding to the volume of a small rat and illuminated by a 3G mobile phone frequency (1718.5 MHz), and the emitted radiation directed toward brain phantom .The induced fields in the phantom material are measured. Set up to lift the plane carrying the mobile phone is run by a pulley whose motion is controlled by a stepper motor. The platform is made to move at a pre-determined rate of 2 degrees per min limited up to 20 degrees. The measured data for induced fields in various locations are used to compute corresponding SAR values and inter comparison obtained. These data are also compared with those when the mobile phone is placed horizontally with respect to the position of the animal. The SAR data is also experimentally obtained by measuring a rise in temperature due to this mobile exposures and data compared with those obtained in the previous set. To seek a comparison with the safety criteria same set of measurements are performed in 10 g phantom material contained in a cubical box. These results are higher than those obtained with the knowledge of induced field measurements. It is concluded that SAR values are sensitive to the angular position of the moving platform and are well below the safety criteria prescribed for human exposure. The data are suggestive of having a fresh look to understand the mode of electromagnetic field -bio interaction.

  6. A summary of the performance of exposure rate and dose rate instruments contained in instrument evaluation reports NRPB-IE1 to NRPB-IE13

    International Nuclear Information System (INIS)

    Burgess, P.H.; Iles, W.J.

    1979-06-01

    The various radiations encountered in radiological protection cover a wide range of energies and radiation measurements have to be carried out under an equally broad spectrum of environmental conditions. This report is one of a series intended to give information on the performance characteristics of radiological protection instruments, to assist in the selection of appropriate instruments for a given purpose, to interpret the results obtained with such instruments, and, in particular, to know the likely sources and magnitude of errors that might be associated with measurements in the field. The radiation, electrical and environmental characteristics of radiation protection instruments are considered together with those aspects of the construction which make an instrument convenient for routine use. To provide consistent criteria for instrument performance, the range of tests performed on any particular class of instrument, the test methods and the criteria of acceptable performance are based broadly on the appropriate Recommendations of the International Electrotechnical Commission. The radiations in the tests are, in general, selected from the range of reference radiations for instrument calibration being drawn up by the International Standards Organisation. Normally, each report deals with the capabilities and limitations of one model of instrument and no direct comparison with other instruments intended for similar purposes is made, since the significance of particular performance characteristics largely depends on the radiations and environmental conditions in which the instrument is to be used. The results quoted here have all been obtained from tests on instruments in routine production, with the appropriate measurements being made by the NRPB. This report provides a concise summary of measurements of the more important performance characteristics of radiation protection dose rate or exposure rate survey instruments which have been assessed by NRPB as part

  7. Maximum likely scale estimation

    DEFF Research Database (Denmark)

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo

    2005-01-01

    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

  8. Robust Maximum Association Estimators

    NARCIS (Netherlands)

    A. Alfons (Andreas); C. Croux (Christophe); P. Filzmoser (Peter)

    2017-01-01

    textabstractThe maximum association between two multivariate variables X and Y is defined as the maximal value that a bivariate association measure between one-dimensional projections αX and αY can attain. Taking the Pearson correlation as projection index results in the first canonical correlation

  9. Effect of exposure to good vs poor medical trainee performance on attending physician ratings of subsequent performances.

    Science.gov (United States)

    Yeates, Peter; O'Neill, Paul; Mann, Karen; Eva, Kevin W

    2012-12-05

    Competency-based models of education require assessments to be based on individuals' capacity to perform, yet the nature of human judgment may fundamentally limit the extent to which such assessment is accurately possible. To determine whether recent observations of the Mini Clinical Evaluation Exercise (Mini-CEX) performance of postgraduate year 1 physicians influence raters' scores of subsequent performances, consistent with either anchoring bias (scores biased similar to previous experience) or contrast bias (scores biased away from previous experience). Internet-based randomized, blinded experiment using videos of Mini-CEX assessments of postgraduate year 1 trainees interviewing new internal medicine patients. Participants were 41 attending physicians from England and Wales experienced with the Mini-CEX, with 20 watching and scoring 3 good trainee performances and 21 watching and scoring 3 poor performances. All then watched and scored the same 3 borderline video performances. The study was completed between July and November 2011. The primary outcome was scores assigned to the borderline videos, using a 6-point Likert scale (anchors included: 1, well below expectations; 3, borderline; 6, well above expectations). Associations were tested in a multivariable analysis that included participants' sex, years of practice, and the stringency index (within-group z score of initial 3 ratings). The mean rating scores assigned by physicians who viewed borderline video performances following exposure to good performances was 2.7 (95% CI, 2.4-3.0) vs 3.4 (95% CI, 3.1-3.7) following exposure to poor performances (difference of 0.67 [95% CI, 0.28-1.07]; P = .001). Borderline videos were categorized as consistent with failing scores in 33 of 60 assessments (55%) in those exposed to good performances and in 15 of 63 assessments (24%) in those exposed to poor performances (P performances compared with 25 of 63 assessments (39.5%) in those exposed to poor performances (P poor

  10. A single exposure to acrolein causes arrhythmogenesis, cardiac electrical dysfunction and decreased heart rate variability in hypertensive rats

    Science.gov (United States)

    Epidemiological studies demonstrate an association between cardiovascular morbidity, arrhythmias, and exposure to air toxicants such as acrolein. We hypothesized that a single exposure to acrolein would increase arrhythmias and cause changes in the electrocardiogram (ECG) of hype...

  11. EFFECTS OF SUBCHRONIC EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON ELECTROCARDIOGRAM AND HEART RATE VARIABILITY IN SPONTANEOUSLY HYPERTENSIVE RATS

    Science.gov (United States)

    Epidemiological studies have linked air pollution exposure to adverse respiratory health effects, especially in individuals with inflammatory airways disease. Symptomatic asthmatics appear to be at greatest risk. We previously demonstrated that exposure of rats to particulate...

  12. Radiation exposure reduction technologies for a Japanese Advanced BWR (Dose Rate Reduction Experience in Shika Unit 2)

    International Nuclear Information System (INIS)

    Saito, Takeshi; Ichikawa, Koji; Ishimaru, Hiroshi; Aizawa, Motohiro; Sato, Yoshiteru; Morita, Shoichi

    2012-09-01

    Operating experiences of the advanced boiling water reactor (ABWR) have been accumulated in Japan since the first ABWRs Kashiwazaki-Kariwa NPS unit 6 and 7 came into service. Shika NPS unit 2 (Shika-2) of Hokuriku Electric Power Co. is the fourth ABWR plant in Japan. Since ABWRs have no piping of the reactor recirculation system (RRS), which is the largest source of radiation in conventional BWRs, carbon steel piping of the reactor water cleanup system (RWCU) and residual heat removal system (RHR) are the largest source in ABWRs. Therefore we have focused on reduction methods of radioactive material on carbon steel surface in order to reduce the quantity of occupational exposure in Shika-2. In Shika-2 the following methods have been adopted. Before fuel loading, alkaline pre-filming process was applied to the RWCU piping during plant startup testing. After start of operation, the feed water iron concentration control (or nickel/iron ratio control) method was applied. Furthermore, during shutdown operation the RHR system was operated when the reactor water temperature was dropped to 120 degree C with the use of condenser heat sink cooling operation. These dose rate reduction methods worked well in Shika-2 as expected. The quantity of occupational exposure at the 3 rd outage in Shika-2 was approximately 0.35 person-Sv. On the basis of the results obtained thus far, the occupational dose expected at the outage after deposition amount of radioactivity reaching the equilibrium state has been estimated to be around 0.5 person-Sv. This value is considered to be in low level compared with the worldwide statistics. (authors)

  13. A Hubble Space Telescope Survey for Novae in M87. II. Snuffing out the Maximum Magnitude–Rate of Decline Relation for Novae as a Non-standard Candle, and a Prediction of the Existence of Ultrafast Novae

    Energy Technology Data Exchange (ETDEWEB)

    Shara, Michael M.; Doyle, Trisha; Zurek, David [Department of Astrophysics, American Museum of Natural History, Central Park West and 79th Street, New York, NY 10024-5192 (United States); Lauer, Tod R. [National Optical Astronomy Observatory, P.O. Box 26732, Tucson, AZ 85726 (United States); Baltz, Edward A. [KIPAC, SLAC, 2575 Sand Hill Road, M/S 29, Menlo Park, CA 94025 (United States); Kovetz, Attay [School of Physics and Astronomy, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv (Israel); Madrid, Juan P. [CSIRO, Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia); Mikołajewska, Joanna [N. Copernicus Astronomical Center, Polish Academy of Sciences, Bartycka 18, PL 00-716 Warsaw (Poland); Neill, J. D. [California Institute of Technology, 1200 East California Boulevard, MC 278-17, Pasadena CA 91125 (United States); Prialnik, Dina [Department of Geosciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978 (Israel); Welch, D. L. [Department of Physics and Astronomy, McMaster University, Hamilton, L8S 4M1, Ontario (Canada); Yaron, Ofer [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel)

    2017-04-20

    The extensive grid of numerical simulations of nova eruptions from the work of Yaron et al. first predicted that some classical novae might significantly deviate from the Maximum Magnitude–Rate of Decline (MMRD) relation, which purports to characterize novae as standard candles. Kasliwal et al. have announced the observational detection of a new class of faint, fast classical novae in the Andromeda galaxy. These objects deviate strongly from the MMRD relationship, as predicted by Yaron et al. Recently, Shara et al. reported the first detections of faint, fast novae in M87. These previously overlooked objects are as common in the giant elliptical galaxy M87 as they are in the giant spiral M31; they comprise about 40% of all classical nova eruptions and greatly increase the observational scatter in the MMRD relation. We use the extensive grid of the nova simulations of Yaron et al. to identify the underlying causes of the existence of faint, fast novae. These are systems that have accreted, and can thus eject, only very low-mass envelopes, of the order of 10{sup −7}–10{sup −8} M {sub ⊙}, on massive white dwarfs. Such binaries include, but are not limited to, the recurrent novae. These same models predict the existence of ultrafast novae that display decline times, t {sub 2,} to be as short as five hours. We outline a strategy for their future detection.

  14. Habitat reclamation plan to mitigate for the loss of habitat due to oil and gas production activities under maximum efficient rate, Naval Petroleum Reserve No. 1, Kern County, California

    International Nuclear Information System (INIS)

    Anderson, D.C.

    1994-11-01

    Activities associated with oil and gas development under the Maximum Efficiency Rate (MER) from 1975 to 2025 will disturb approximately 3,354 acres. Based on 1976 aerial photographs and using a dot grid methodology, the amount of land disturbed prior to MER is estimated to be 3,603 acres. Disturbances on Naval Petroleum Reserve No. 1 (NPR-1) were mapped using 1988 aerial photography and a geographical information system. A total of 6,079 acres were classified as disturbed as of June, 1988. The overall objective of this document is to provide specific information relating to the on-site habitat restoration program at NPRC. The specific objectives, which relate to the terms and conditions that must be met by DOE as a means of protecting the San Joaquin kit fox from incidental take are to: (1) determine the amount and location of disturbed lands on NPR-1 and the number of acres disturbed as a result of MER activities, (2) develop a long term (10 year) program to restore an equivalent on-site acres to that lost from prior project-related actions, and (3) examine alternative means to offset kit fox habitat loss

  15. Beyond Extinction: Prolonged Conditioning and Repeated Threat Exposure Abolish Contextual Renewal of Fear-Potentiated Startle Discrimination but Leave Expectancy Ratings Intact.

    Science.gov (United States)

    Leer, Arne; Haesen, Kim; Vervliet, Bram

    2018-01-01

    Extinction treatments decrease fear via repeated exposures to the conditioned stimulus (CS) and are associated with a return of fear. Alternatively, fear can be reduced via reductions in the perceived intensity of the unconditioned stimulus (US), e.g., through repeated exposures to the US. Promisingly, the few available studies show that repeated US exposures outperform standard extinction. US exposure treatments can decrease fear via two routes: (1) by weakening the CS-US association (extinction-like mechanism), and/or (2) by weakening the subjective US aversiveness (habituation-like mechanism). The current study further investigated the conditions under which US exposure treatment may reduce renewal, by adding a group in which CS-US pairings continued following fear acquisition. During acquisition, participants learned that one of two visual stimuli (CS+/CS-) predicted the occurrence of an aversive electrocutaneous stimulus (US). Next, the background context changed and participants received one of three interventions: repeated CS exposures, (2) repeated US exposures, or (3) continued CS-US pairings. Following repeated CS exposures, test presentations of the CSs in the original conditioning context revealed intact CS+/CS- differentiation in the fear-potentiated startle reflex, while the differentiation was abolished in the other two groups. Differential US expectancy ratings, on the other hand, were intact in all groups. Skin conductance data were inconclusive because standard context renewal following CS exposures did not occur. Unexpectedly, there was no evidence for a habituation-like process having taken place during US exposures or continued CS-US pairings. The results provide further evidence that US exposures outperform the standard extinction treatment and show that effects are similar when US exposures are part of CS-US pairings.

  16. A multi-nuclide approach to quantify long-term erosion rates and exposure history through multiple glacial-interglacial cycles

    DEFF Research Database (Denmark)

    Strunk, Astrid; Larsen, Nicolaj Krog; Knudsen, Mads Faurschou

    Cosmogenic nuclides are traditionally used to either determine the glaciation history or the denudation history of the most recent exposure period. A few studies use the cosmogenic nuclides to determine the cumulative exposure and burial durations of a sample. However, until now it has not been...... possible to resolve the complex pattern of exposure history under a fluctuating ice sheet. In this study, we quantify long-term erosion rates along with durations of multiple exposure periods in West Greenland by applying a novel Markov Chain Monte Carlo (MCMC) inversion approach to existing 10Be and 26Al....... The new MCMC approach allows us to constrain the most likely landscape history based on comparisons between simulated and measured cosmogenic nuclide concentrations. It is a fundamental assumption of the model that the exposure history at the site/location can be divided into two distinct regimes: i...

  17. Assessment of prescription opioid intentional exposures across the rural-urban continuum in the United States using both population and drug availability rates.

    Science.gov (United States)

    Le Lait, Marie-Claire; Martinez, Erin M; Severtson, Stevan G; Lavery, Sarah A; Bucher-Bartelson, Becki; Dart, Richard C

    2014-12-01

    Prescription opioid abuse and misuse are a serious problem in the U.S. today. Several studies have shown that the epidemic disproportionately affects rural areas. This paper uses three different rates to gain a more complete picture of opioid abuse in rural areas. This study examines prescription opioid intentional exposures using opioid classes tracked in the RADARS(®) System Poison Center Program. Intentional exposure rates were calculated adjusting for population and unique recipients of dispensed drug (URDD). These rates were analyzed using time (quarter) and the proportion of a three-digit zip code residing in a rural area as covariates. Additionally, the URDD per population rate was calculated to examine the proportion of the population filling prescriptions for opioids. After adjusting for population, intentional exposure cases significantly increased as the proportion of the population residing in a rural area increased. However, when adjusting for URDD, intentional exposure cases decreased with increasing rural population. The URDD per population increased as the proportion of people residing in a rural area increased. Using both population and URDD adjusted intentional exposure rates gives a more complete picture of opioid abuse in rural areas. Considering product availability can be used to develop opioid abuse prevention strategies and further the education of physicians serving rural areas about this epidemic. Copyright © 2014 John Wiley & Sons, Ltd.

  18. Modelling maximum canopy conductance and transpiration in ...

    African Journals Online (AJOL)

    There is much current interest in predicting the maximum amount of water that can be transpired by Eucalyptus trees. It is possible that industrial waste water may be applied as irrigation water to eucalypts and it is important to predict the maximum transpiration rates of these plantations in an attempt to dispose of this ...

  19. Tritium β-radiation induction of chromosomal damage: a calibration curve for low dose, low dose rate exposures of human cells to tritiated water

    International Nuclear Information System (INIS)

    Morrison, D.P.; Gale, K.L.; Lucas, J.N.

    1997-01-01

    Radiation exposures from tritium contribute to the occupational radiation exposures associated with CANDU reactors. Tritiated water is of particular interest since it is readily taken up by human cells and its elimination from the body, and, consequently, the radiation exposure of the cells, is spread over a period of days. Occupational exposures to tritiated water result in what are effectively chronic β-radiation exposures. The doses and dose rates ordinarily used in the definition of cellular responses to radiation in vitro, for use in biological dosimetry (the assessment of radiation exposures based on the observed levels of changes in the cells of exposed individuals), are usually much higher than for most occupational exposures and involve radiations other than tritium β-rays. As a result, their use in assessing the effects from tritiated water exposures may not be appropriate. We describe here an in vitro calibration curve for chronic tritium β-radiation induction of reciprocal chromosomal translocations in humn peripheral blood lymphocytes (PBLs) for use in biodosimetry. (author)

  20. Study on cancer induced by long-term exposure to low dose rate radiation and its treatment

    International Nuclear Information System (INIS)

    Takahashi, Shinji

    1980-01-01

    For the purpose of discovering measures to prevent carcinogenesis by exposure to low dose radiation, radiological and clinical studies were carried out on patients with previous thorotrast injection. X-ray findings of these patients were classified into 8 types; the amount of injected thorotrast was not proportional to the size of the liver or spleen. CT could visualize sites of lymph nodes where thorotrast was remained and intrahepatic distribution of thorotrast. CT was also useful for detecting hepatic carcinoma. The amounts of thorotrast in each organ were calculated from the measurement by the whole body counter, and interstitial thorotrast was identified by fluorescent x-ray analysis. Numerical chromosome aberrations were found in all 9 patients with thorotrast; structural chromosome aberrations were found in 3 of the 9 patients. The appearance rates of small nuclei and H-J bodies in the bone marrow were higher in these patients than in controls. When patients with thorotrast had liver failure, their conditions deteriorated rapidly. Amino acid transfusion by Fisher's description was effective for hepatic encephalopathy. Out of 170 necropsied cases with thorotrast, 112 had malignant tumors of the liver with statistically significance compared to the control population. (Tsunoda, M.)

  1. Study on cancer induced by long-term exposure to low dose rate radiation and its treatment

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, S. (Hamamatsu Univ. School of Medicine, Shizuoka (Japan))

    1980-06-01

    For the purpose of discovering measures to prevent carcinogenesis by exposure to low dose radiation, radiological and clinical studies were carried out on patients with previous thorotrast injection. X-ray findings of these patients were classified into 8 types; the amount of injected thorotrast was not proportional to the size of the liver or spleen. CT could visualize sites of lymph nodes where thorotrast was remained and intrahepatic distribution of thorotrast. CT was also useful for detecting hepatic carcinoma. The amounts of thorotrast in each organ were calculated from the measurement by the whole body counter, and interstitial thorotrast was identified by fluorescent x-ray analysis. Numerical chromosome aberrations were found in all 9 patients with thorotrast; structural chromosome aberrations were found in 3 of the 9 patients. The appearance rates of small nuclei and H-J bodies in the bone marrow were higher in these patients than in controls. When patients with thorotrast had liver failure, their conditions deteriorated rapidly. Amino acid transfusion by Fisher's description was effective for hepatic encephalopathy. Out of 170 necropsied cases with thorotrast, 112 had malignant tumors of the liver with statistically significance compared to the control population.

  2. The Effect of Exposure to High Noise Levels on the Performance and Rate of Error in Manual Activities.

    Science.gov (United States)

    Khajenasiri, Farahnaz; Zamanian, Alireza; Zamanian, Zahra

    2016-03-01

    Sound is among the significant environmental factors for people's health, and it has an important role in both physical and psychological injuries, and it also affects individuals' performance and productivity. The aim of this study was to determine the effect of exposure to high noise levels on the performance and rate of error in manual activities. This was an interventional study conducted on 50 students at Shiraz University of Medical Sciences (25 males and 25 females) in which each person was considered as its own control to assess the effect of noise on her or his performance at the sound levels of 70, 90, and 110 dB by using two factors of physical features and the creation of different conditions of sound source as well as applying the Two-Arm coordination Test. The data were analyzed using SPSS version 16. Repeated measurements were used to compare the length of performance as well as the errors measured in the test. Based on the results, we found a direct and significant association between the levels of sound and the length of performance. Moreover, the participant's performance was significantly different for different sound levels (at 110 dB as opposed to 70 and 90 dB, p < 0.05 and p < 0.001, respectively). This study found that a sound level of 110 dB had an important effect on the individuals' performances, i.e., the performances were decreased.

  3. Low-dose-rate radiation exposure leads to testicular damage with decreases in DNMT1 and HDAC1 in the murine testis

    International Nuclear Information System (INIS)

    Gong, Eun Ji; Son, Tae Gen; Yang, Kwangmo; Heo, Kyu; Kim, Joong Sun; Shin, In Sik

    2014-01-01

    This study examined the effects of continuous low-dose-rate radiation exposure (3.49 mGy/h) of gamma rays on mice testicles. C57BL/6 mice were divided into sham and radiation groups (n = 8 each), and were exposed to either sham irradiation or 2 Gy for 21 days, 0.2 Gy for 2 days, or 0.02 Gy for 6 h of low-dose-rate irradiation. Testicular weight, seminiferous tubular diameter, and seminiferous epithelial depth were significantly decreased in the mice irradiated with 2 Gy at 1 and 9 days after exposure. Moreover, the low-dose-rate radiation exposure induced an increase in malondialdehyde levels, and a decrease in superoxide dismutase activity in the testis of mice irradiated with 2 Gy at 1 and 9 days after exposure. The sperm count and motility in the epididymis also decreased in mice irradiated with 2 Gy at 1 and 9 days after exposure, whereas there was no significant effect on the proportion of abnormal sperm. The expressions of DNA methlytransferases-1 and histone deacetylases 1 in testes irradiated with 2 Gy were significantly decreased compared with the sham group. In conclusion, the damage exerted on the testes and epididymis largely depended on the total dose of low-dose-rate radiation. (author)

  4. Maximum entropy methods

    International Nuclear Information System (INIS)

    Ponman, T.J.

    1984-01-01

    For some years now two different expressions have been in use for maximum entropy image restoration and there has been some controversy over which one is appropriate for a given problem. Here two further entropies are presented and it is argued that there is no single correct algorithm. The properties of the four different methods are compared using simple 1D simulations with a view to showing how they can be used together to gain as much information as possible about the original object. (orig.)

  5. Freqüência cardíaca máxima em idosas brasileiras: uma comparação entre valores medidos e previstos Maximum heart rate in Brazilian elderly women: comparing measured and predicted values

    Directory of Open Access Journals (Sweden)

    Valter Abrantes Pereira da Silva

    2007-03-01

    Full Text Available OBJETIVO: O presente estudo objetivou comparar os valores de freqüência cardíaca máxima (FCmáx medidos durante um teste de esforço progressivo (TEP, com os obtidos através de equações de predição, em idosas brasileiras. MÉTODOS: Um TEP máximo sob o protocolo modificado de Bruce, realizado em esteira, foi utilizado para obtenção dos valores de referência da freqüência cardíaca máxima (FCmáx, em 93 mulheres idosas (67,1±5,16 anos. Os valores obtidos foram comparados aos estimados pelas equações "220 - idade" e a de Tanaka e cols., através da ANOVA, para amostras repetidas. A correlação e a concordância entre os valores medidos e os estimados foram testadas. Adicionalmente, a correlação entre os valores de FCmáx medidos e a idade das voluntárias foi examinada. RESULTADOS: Os resultados foram os seguintes: 1 a média da FCmáx atingida no TEP foi de 145,5±12,5 batimentos por minuto (bpm; 2 as equações "220 - idade" e a de Tanaka e cols. (2001 superestimaram significativamente (p OBJECTIVE: This study sought to compare maximum heart rate (HRmax values measured during a graded exercise test (GXT with those calculated from prediction equations in Brazilian elderly women. METHODS: A treadmill maximal graded exercise test in accordance with the modified Bruce protocol was used to obtain reference values for maximum heart rate (HRmax in 93 elderly women (mean age 67.1 ± 5.16. Measured values were compared with those estimated from the "220 - age" and Tanaka et al formulas using repeated-measures ANOVA. Correlation and agreement between measured and estimated values were tested. Also evaluated was the correlation between measured HRmax and volunteers’ age. RESULTS: Results were as follows: 1 mean HRmax reached during GXT was 145.5 ± 12,5 beats per minute (bpm; 2 both the "220 - age" and Tanaka et al (2001 equations significantly overestimated (p < 0.001 HRmax by a mean difference of 7.4 and 15.5 bpm, respectively; 3

  6. The last glacial maximum

    Science.gov (United States)

    Clark, P.U.; Dyke, A.S.; Shakun, J.D.; Carlson, A.E.; Clark, J.; Wohlfarth, B.; Mitrovica, J.X.; Hostetler, S.W.; McCabe, A.M.

    2009-01-01

    We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. Nearly all ice sheets were at their LGM positions from 26.5 ka to 19 to 20 ka, corresponding to minima in these forcings. The onset of Northern Hemisphere deglaciation 19 to 20 ka was induced by an increase in northern summer insolation, providing the source for an abrupt rise in sea level. The onset of deglaciation of the West Antarctic Ice Sheet occurred between 14 and 15 ka, consistent with evidence that this was the primary source for an abrupt rise in sea level ???14.5 ka.

  7. Determination of exposure rates from natural background radiation in Khartoum using LiF:Mg,Cu,P (GR-200) and CaSo4: Mn TLD chips

    International Nuclear Information System (INIS)

    Suliman, I.I.; Khangi, F.A.; Shaddad, I.A.; Suliman, I.A.; El Amin, O.I.

    2002-01-01

    The exposure rates from natural background radiation - including terrestrial gamma radiation and the ionizing component of cosmic rays - were measured for the first time in the city of khartoum using two types of TLD materials: LiF:Mg,Cu,P (GR-200) and CaSo 4 :Mn TLD chips. Measurements were performed at two sites simultaneously, one site was selected on land in the vicinity of the Sudan Atomic Energy Commission, for the purposes of the measurement of the total exposure rate outdoors, while the other site was located on a buoy anchored in the Blue Nile, and was selected to measure the exposure rate due to the ionizing component of cosmic rays. The investigations were conducted for periods of between 5 and 28 days. Calibration was performed on a selected number of dosimeters to determine the exposure rates at each site. The exposure rates from the ionizing component of cosmic rays in Khartoum were found to be respectively 33 nGy.h -1 and 30 nGy.h -1 , in the measurements performed within the scope of this work using GR-200 and CaSo 4 :Mn dosimeters, while the total values for exposure on land were found to be 45 nGy.h -1 and 42 nGy.h -1 respectively. These values compare reasonably well with other national averages reported in the UNSCEAR publication. The comparison of the results for the two dosimetric materials demonstrates both the sensitivity and suitability of GR-200 for the purposes of environmental monitoring (orig.)

  8. Maximum Entropy Fundamentals

    Directory of Open Access Journals (Sweden)

    F. Topsøe

    2001-09-01

    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  9. Does Temperature and UV Exposure History Modulate the Effects of Temperature and UV Stress on Symbiodinium Growth Rates?

    Science.gov (United States)

    Temperature and ultraviolet radiation (UV) alone or in combination are known to inhibit the growth of Symbiodinium isolates. This conclusion was drawn from a number of studies having widely different exposure scenarios. Here we have examined the effects of pre-exposure acclimat...

  10. Effects of oral exposure duration and gastric energy content on appetite ratings and energy intake in lean men

    NARCIS (Netherlands)

    Wijlens, Anne G.M.; Graaf, de Kees; Erkner, Alfrun; Mars, Monica

    2016-01-01

    Studies show that longer oral exposure to food leads to earlier satiation and lowers energy intake. Moreover, higher energy content of food has been shown to lead to higher satiety. Up to now, it has not been studied systematically how oral exposure duration and gastric energy content interact in

  11. Probable maximum flood control

    International Nuclear Information System (INIS)

    DeGabriele, C.E.; Wu, C.L.

    1991-11-01

    This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility

  12. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1988-01-01

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

  13. Solar maximum observatory

    International Nuclear Information System (INIS)

    Rust, D.M.

    1984-01-01

    The successful retrieval and repair of the Solar Maximum Mission (SMM) satellite by Shuttle astronauts in April 1984 permitted continuance of solar flare observations that began in 1980. The SMM carries a soft X ray polychromator, gamma ray, UV and hard X ray imaging spectrometers, a coronagraph/polarimeter and particle counters. The data gathered thus far indicated that electrical potentials of 25 MeV develop in flares within 2 sec of onset. X ray data show that flares are composed of compressed magnetic loops that have come too close together. Other data have been taken on mass ejection, impacts of electron beams and conduction fronts with the chromosphere and changes in the solar radiant flux due to sunspots. 13 references

  14. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1989-01-01

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

  15. Functional Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg

    2005-01-01

    MAF outperforms the functional PCA in concentrating the interesting' spectra/shape variation in one end of the eigenvalue spectrum and allows for easier interpretation of effects. Conclusions. Functional MAF analysis is a useful methods for extracting low dimensional models of temporally or spatially......Purpose. We aim at data where samples of an underlying function are observed in a spatial or temporal layout. Examples of underlying functions are reflectance spectra and biological shapes. We apply functional models based on smoothing splines and generalize the functional PCA in......\\verb+~+\\$\\backslash\\$cite{ramsay97} to functional maximum autocorrelation factors (MAF)\\verb+~+\\$\\backslash\\$cite{switzer85,larsen2001d}. We apply the method to biological shapes as well as reflectance spectra. {\\$\\backslash\\$bf Methods}. MAF seeks linear combination of the original variables that maximize autocorrelation between...

  16. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yunji; Jing, Bing-Yi; Gao, Xin

    2015-01-01

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  17. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  18. A re-evaluation of the 0-10 ka 10Be production rate for exposure dating obtained from the Koefels (Austria) landslide

    International Nuclear Information System (INIS)

    Kubik, Peter W.; Ivy-Ochs, Susan

    2004-01-01

    The sea level, high latitude 10 Be production rate for exposure dating obtained from the giant 9.8 ka landslide of Koefels (Austria) has been calculated based on a re-assessment of the contribution of the muonic cosmic ray component. The 0-10 ka production rate value is 5.44 ± 0.19 10 Be atoms/y g quartz

  19. Results of calculations of external gamma radiation exposure rates from local fallout and the related radionuclide compositions of two hypothetical 1-MT nuclear bursts. Final report

    International Nuclear Information System (INIS)

    Hicks, H.

    1984-12-01

    This report presents data on calculated gamma radiation exposure rates and local surface deposition of related radionuclides resulting from two hypothetical 1-Mt nuclear bursts. Calculations are made of the debris from two types of bombs: one containing 235 U as a fissionable material (designated oralloy), the other containing 238 U (designated tuballoy). 4 references

  20. Identifying Housing and Meteorological Conditions Influencing Residential Air Exchange Rates in the DEARS and RIOPA Studies: Development of Distributions for Human Exposure Modeling

    Science.gov (United States)

    Appropriate prediction of residential air exchange rate (AER) is important for estimating human exposures in the residential microenvironment, as AER drives the infiltration of outdoor-generated air pollutants indoors. AER differences among homes may result from a number of fact...

  1. Difference in the craniocaudal gradient of the maximum pixel value change rate between chronic obstructive pulmonary disease patients and normal subjects using sub-mGy dynamic chest radiography with a flat panel detector system.

    Science.gov (United States)

    Yamada, Yoshitake; Ueyama, Masako; Abe, Takehiko; Araki, Tetsuro; Abe, Takayuki; Nishino, Mizuki; Jinzaki, Masahiro; Hatabu, Hiroto; Kudoh, Shoji

    2017-07-01

    To compare the craniocaudal gradients of the maximum pixel value change rate (MPCR) during tidal breathing between chronic obstructive pulmonary disease (COPD) patients and normal subjects using dynamic chest radiography. This prospective study was approved by the institutional review board and all participants provided written informed consent. Forty-three COPD patients (mean age, 71.6±8.7 years) and 47 normal subjects (non-smoker healthy volunteers) (mean age, 54.8±9.8 years) underwent sequential chest radiographs during tidal breathing in a standing position using dynamic chest radiography with a flat panel detector system. We evaluated the craniocaudal gradient of MPCR. The results were analyzed using an unpaired t-test and the Tukey-Kramer method. The craniocaudal gradients of MPCR in COPD patients were significantly lower than those in normal subjects (right inspiratory phase, 75.5±48.1 vs. 108.9±42.0s -1 cm -1 , P<0.001; right expiratory phase, 66.4±40.6 vs. 89.8±31.6s -1 cm -1 , P=0.003; left inspiratory phase, 75.5±48.2 vs. 108.2±47.2s -1 cm -1 , P=0.002; left expiratory phase, 60.9±38.2 vs. 84.3±29.5s -1 cm -1 , P=0.002). No significant differences in height, weight, or BMI were observed between COPD and normal groups. In the sub-analysis, the gradients in severe COPD patients (global initiative for chronic obstructive lung disease [GOLD] 3 or 4, n=26) were significantly lower than those in mild COPD patients (GOLD 1 or 2, n=17) for both right and left inspiratory/expiratory phases (all P≤0.005). A decrease of the craniocaudal gradient of MPCR was observed in COPD patients. The craniocaudal gradient was lower in severe COPD patients than in mild COPD patients. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  2. Work to save dose: contrasting effective dose rates from radon exposure in workplaces and residences against the backdrop of public and occupational limits

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, Jeffrey J [Los Alamos National Laboratory; Mcnaughton, Michael W [Los Alamos National Laboratory

    2009-01-01

    Office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the non-mine workplaces are lacking. Additionally, there are few, if any, comparative analyses of radon exposures at more 'typical' workplace with residential exposures within the same county. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about 8 times greater exposure at home than while in the office (2.3 mSv yr-! versus 0.3 mSv yr-!). The estimated effective dose rate for a more homebound person was about 3 mSv yr-!. Estimating effective doses from background radon exposure in the same county as Los Alamos National Laboratory, with thousands of'radiological workers,' highlights interesting contrasts in radiation protection standards that span public and occupational settings. For example, the effective dose rate from background radon exposure in unregulated office spaces ranged up to 1.1 mSv yr-!, which is similar to the 1 mSv yr-! threshold for regulation ofa 'radiological worker,' as defined in the Department of Energy regulations for occupational exposure. Additionally, the estimated average effective dose total of> 3 mSv yf! from radon background exposure in homes stands in

  3. Work to save dose: contrasting effective dose rates from radon exposure in workplaces and residences against the backdrop of public and occupational limits

    International Nuclear Information System (INIS)

    Whicker, Jeffrey J.; Mcnaughton, Michael W.

    2009-01-01

    Office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the non-mine workplaces are lacking. Additionally, there are few, if any, comparative analyses of radon exposures at more 'typical' workplace with residential exposures within the same county. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about 8 times greater exposure at home than while in the office (2.3 mSv yr- versus 0.3 mSv yr-). The estimated effective dose rate for a more homebound person was about 3 mSv yr-. Estimating effective doses from background radon exposure in the same county as Los Alamos National Laboratory, with thousands of'radiological workers,' highlights interesting contrasts in radiation protection standards that span public and occupational settings. For example, the effective dose rate from background radon exposure in unregulated office spaces ranged up to 1.1 mSv yr-, which is similar to the 1 mSv yr- threshold for regulation ofa 'radiological worker,' as defined in the Department of Energy regulations for occupational exposure. Additionally, the estimated average effective dose total of> 3 mSv yf from radon background exposure in homes stands in contrast to the 0.1 mSv yr- air pathway

  4. Solar maximum mission

    International Nuclear Information System (INIS)

    Ryan, J.

    1981-01-01

    By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

  5. Effects of Acute Ozone Exposure and Methyl Jasmonate Treatment on White Pine Monoterpene and Sesquiterpene Emission Rates

    Science.gov (United States)

    Faiola, C. L.; Wagner, D.; Allwine, E.; Harley, P. C.; Vanreken, T. M.

    2010-12-01

    Biogenic volatile organic compounds (BVOCs) are produced by plants and include monoterpenes, sesquiterpenes, and their oxygenated derivatives. These BVOCs are one of the principal factors influencing the oxidative capacity of the atmosphere in forested regions, and impact both ozone concentration and secondary organic aerosol formation. Under unstressed conditions, the release of BVOCs to the atmosphere is primarily controlled by the vapor pressure of the relevant compounds within the plant tissue, which is in turn dependent on temperature as well as complex biochemical production processes. However, various natural and anthropogenic stressors can alter both the quantity and composition of the BVOCs emitted by plants. Many potential stressors are expected to become stronger as climate change effects escalate. The impacts of most stressors on BVOC emissions have not been well characterized, particularly in a field setting where changes in BVOC emissions could have influential feedbacks with climate. This study investigated the effects of two stressors on monoterpene and sesquiterpene emission rates at a field site in northern Michigan: acute ozone exposure and treatment with methyl jasmonate, an herbivory proxy. The study included six repetitions of the same experiment, each time using a new set of sub-canopy eastern white pine specimens. For each experiment, dynamic branch enclosures were simultaneously used on three specimens for sample collection: one ozone treatment tree, one methyl jasmonate treatment tree, and one control tree. Sampling lines were placed in each enclosure and VOCs were collected onto cartridges packed with Tenax GR adsorbent. Samples were collected several times per day for at least two days before treatment and for five days after treatment. Cartridges were analyzed via thermodesorption with an Agilent GC/MS/FID. This analysis allowed the identification and quantification of several monoterpene and sesquiterpene species in the samples

  6. The Effect of Heart Rate on Exposure Window and Best Phase for Stress Perfusion Computed Tomography: Lessons From the CORE320 Study.

    Science.gov (United States)

    Steveson, Chloe; Schuijf, Joanne D; Vavere, Andrea L; Mather, Richard T; Caton, Teresa; Mehra, Vishal; Betoko, Aisha; Cox, Christopher; Lima, Joao Ac; George, Richard T

    The aim of this study is to evaluate the effect of heart rate on exposure window, best phase, and image quality for stress computed tomography perfusion (CTP) in the CORE320 study. The CTP data sets were analyzed to determine the best phase for perfusion analysis. A predefined exposure window covering 75% to 95% of the R-R cycle was used. Of the 368 patients included in the analysis, 93% received oral β blockade before the rest scan. The median heart rate during the stress acquisition was 69 bpm (interquartile range [IQR], 60-77). The median best phase was 81% (IQR, 76-90), and length of exposure window was 22% (IQR, 19-24). The best phase was significantly later in the cardiac cycle with higher heart rates (P stress scan was 5.3 mSv (IQR, 3.8-6.1). Stress myocardial CTP imaging can be performed using prospective electrocardiography triggering, an exposure window of 75% to 95%, and β-blockade resulting in good or excellent image quality in the majority (80%) of patients while maintaining a low effective radiation dose.

  7. Lung cancer mortality (1950-80) in relation to radon daughter exposure in a cohort of workers at the Eldorado Port Radium uranium mine: possible modification of risk by exposure rate

    International Nuclear Information System (INIS)

    Howe, G.R.; Nair, R.C.; Newcombe, H.B.; Miller, A.B.; Burch, J.D.; Abbatt, J.D.

    1987-01-01

    A cohort study of 2103 workers employed between 1942 and 1960 at a uranium mine in the Northwest Territories, Canada, was conducted. A total of 57 lung cancer deaths was observed (expected = 24.73, P less than .0001). There was a highly significant linear relationship between exposure and increased risk of lung cancer, giving estimates for the relative and attributable risk coefficients of 0.27 per working level month (WLM) and 3.10 per WLM per 10(6) person-years. These risk coefficients were substantially less than those estimated from the experience of miners in the Beaverlodge mine, which have previously been reported. Any biases in the present estimates are likely to have been upward, and therefore they probably represent an upper limit. The major difference between the two mine cohorts is in the exposure rate, since the Port Radium miners were exposed to much greater concentrations of radon daughters than the Beaverlodge miners. It is postulated that risk of lung cancer from radon daughter exposure may be modified by exposure rate, for which hypothesis there is some support from other epidemiologic data

  8. Plutonium-aerosol emission rates and potential inhalation exposure during cleanup and treatment test at Area 11, Nevada Test Site

    International Nuclear Information System (INIS)

    Shinn, J.H.; Homan, D.N.

    1985-01-01

    A Cleanup and Treatment (CAT) test was conducted in 1981 at Area 11, Nevada Test Site. Its purpose was to evaluate the effectiveness of using a large truck-mounted vacuum cleaner similar to those used to clean paved streets for cleaning radiological contamination from the surface of desert soils. We found that four passes with the vehicle removed 97% of the alpha contamination and reduced resuspension by 99.3 to 99.7%. Potential exposure to cleanup workers was slight when compared to natural background exposure. 7 refs., 1 fig., 2 tabs

  9. Mimicking the effects of spaceflight on bone: Combined effects of disuse and chronic low-dose rate radiation exposure on bone mass in mice

    Science.gov (United States)

    Yu, Kanglun; Doherty, Alison H.; Genik, Paula C.; Gookin, Sara E.; Roteliuk, Danielle M.; Wojda, Samantha J.; Jiang, Zhi-Sheng; McGee-Lawrence, Meghan E.; Weil, Michael M.; Donahue, Seth W.

    2017-11-01

    During spaceflight, crewmembers are subjected to biomechanical and biological challenges including microgravity and radiation. In the skeleton, spaceflight leads to bone loss, increasing the risk of fracture. Studies utilizing hindlimb suspension (HLS) as a ground-based model of spaceflight often neglect the concomitant effects of radiation exposure, and even when radiation is accounted for, it is often delivered at a high-dose rate over a very short period of time, which does not faithfully mimic spaceflight conditions. This study was designed to investigate the skeletal effects of low-dose rate gamma irradiation (8.5 cGy gamma radiation per day for 20 days, amounting to a total dose of 1.7 Gy) when administered simultaneously to disuse from HLS. The goal was to determine whether continuous, low-dose rate radiation administered during disuse would exacerbate bone loss in a murine HLS model. Four groups of 16 week old female C57BL/6 mice were studied: weight bearing + no radiation (WB+NR), HLS + NR, WB + radiation exposure (WB+RAD), and HLS+RAD. Surprisingly, although HLS led to cortical and trabecular bone loss, concurrent radiation exposure did not exacerbate these effects. Our results raise the possibility that mechanical unloading has larger effects on the bone loss that occurs during spaceflight than low-dose rate radiation.

  10. Notifiable events in systems for fission of nuclear fuels - nuclear power plants and research reactors with maximum output exceeding 50 kW of thermal normal rating - in the Federal Republic of Germany. Quarterly report, 2nd quarter of 1996

    International Nuclear Information System (INIS)

    1996-01-01

    There were 32 notifiable events in nuclear power plants in Germany in the second quarter of 1996. The report lists and characterises all the 32 events notified in the reporting period. The events did not involve any radioactivity release exceeding the maximum permissible limits during this period, so that there were no radiation hazards to the population or the environment. One event was classified at level 1 of the INES event scale (Anomaly). Research reactor operators in Germany reported 5 notifiable events in the reporting period. The report lists and characterises these events. These events did not involve any radioactivity release exceeding the maximum permissible limits during this period, so that there were no radiation hazards to the population or the environment. All events notified were classified into the lowest categories of safety significance of the official event scales (N, or below scale). (orig./DG) [de

  11. Assessment of dietary exposure to flavouring substances via consumption of flavoured teas. Part II: transfer rates of linalool and linalyl esters into Earl Grey tea infusions.

    Science.gov (United States)

    Orth, Anne-Marie; Poplacean, Iulia; Fastowski, Oxana; Engel, Karl-Heinz

    2014-01-01

    The assessment of dietary exposure via the consumption of flavoured foods is a key element of the safety evaluation of flavouring substances. Linalyl acetate and linalool are the major flavouring substances in Earl Grey teas; the objective of this study was to determine their transfer rates from the tea leaves into the tea beverage upon preparation of a hot water infusion. Spiking experiments revealed a transfer rate of 66% for linalool. In contrast, the transfer rate for linalyl acetate was only 1.9%; in turn, the hydrolysis product linalool (17.0%) and a spectrum (19.9%) of degradation and rearrangement products (monoterpene alcohols, esters and hydrocarbons) were present in the tea beverage. The transfer rates were shown to be proportional to the length of the infusion. The impact of the hot water treatment on the enantiomeric compositions of linalyl acetate and linalool was determined, and structure-dependent experiments were performed by variation of the acyl and the alcohol moiety of the monoterpene ester. Comparative dietary exposure assessments demonstrated the need to take correction factors based on the experimentally determined transfer rates into account. Based on tea consumption data from the UK National Diet and Nutrition Survey (2000/2001), the exposure to linalyl acetate ranges from 0.2 mg day(-1) (average) to 1.8 mg day(-1) (high). The corresponding values for linalool are 4.2 mg day(-1) (average) and 46.6 mg day(-1) (high). The exposure of linalool via consumption of the tea beverage is approximately 26 times higher than that of linalyl acetate, although in the flavoured tea leaves the median content of linalyl acetate is approximately 1.8 times higher than that of linalool.

  12. Investigation of influence of 16-slice spiral CT electrocardiogram-controlled dose modulation on exposure dosage and image quality of cardiac CT imaging under simulated fluctuant heart rate

    International Nuclear Information System (INIS)

    Yin Yan; Chen Jie; Chai Weiming; Hua Jia; Gao Na; Xu Jianrong; Shen Yun

    2008-01-01

    Objective: To investigate the influence of electrocardiogram (ECG)-controlled dose modulation on exposure dosage and image quality of cardiac CT imaging in a cardiac phantom with simulated fluctuant heart rate. Methods: The basal heart rate of the cardiac pulsating phantom was set as 60 bpm, the experimental situations were divided as 6 groups according to different heart rates. The cardiac imaging was performed on the cardiac phantom when the ECG-controlled dose modulation was firstly turned off. The exposure dosage of each scan sequence was documented. The standard deviation of the CT values of the phantom was measured on the central slice after coronal reformation of the raw data. The quality of 2D and 3D images were scored. Then cardiac imaging was performed when ECG modulation was on and set as four groups according to different modulation parameters. All the data were documented as before. The results from the five groups with and without ECG modulation current were analyzed by F test and comparative rank sum test using the statistical software SPSS 10.0. Results: Statistical analysis showed no significant difference (P>0.05) between the SNR of images (SD value was 27.78 and 26.30) from the groups that full mA output at wide reconstruction phase (69%-99%) when the heart rate was fluctuant(≥7.5 bpm). There was also no significant difference (P>0.05) between the quality of the 2D and 3D images. But there was a significant difference (P 12.5 bpm, the exposure dosage would increase obviously (from 0.6 to 1.7 mSv). Conclusion: For cardiac imaging with 16-slice row CT, the application of ECG modulated current can effectively reduce the exposure dosage without compromising the image quality even if heart rate was fluctuant. (authors)

  13. Night-Time Decibel Hell: Mapping Noise Exposure Zones and Individual Annoyance Ratings in an Urban Environment in Ghana

    Directory of Open Access Journals (Sweden)

    Rachel N. Zakpala

    2014-01-01

    Full Text Available Although accumulating evidence over the past thirty years indicates that noise is an environmental stressor in residential settings, much of the data emanated from studies in high-intensity, noise impact zones around airports or major roads. Little is known about religious noise, especially at night, which is increasingly a growing concern for both the general public and policy-makers in sub-Saharan Africa. Using geographical information systems (GIS, this study measured and mapped exposure to religious noise in a rapidly urbanising municipality in Ghana. Quantitative noise risk assessment was used to evaluate the risk of religious noise-induced hearing loss to residents in the exposed neighbourhoods. The results show that all neighbourhoods where churches were situated had at least one location with significant risk of noise-induced hearing loss. However, there was no statistically significant relationship between neighbourhoods where religious noise exposure was the highest and where noise annoyance was the highest. The magnitude of the noise values for night-time exposure is remarkable particularly given that excessive night-time noise exposure has the greatest detrimental effect on public health. There is the need to focus on vulnerable groups, sensitive hours of the night, and possible confounding with air pollution in order to wholly address this potential hazard.

  14. Links between Self-Reported Media Violence Exposure and Teacher Ratings of Aggression and Prosocial Behavior among German Adolescents

    Science.gov (United States)

    Krahe, Barbara; Moller, Ingrid

    2011-01-01

    The relations between adolescents' habitual usage of media violence and their tendency to engage in aggressive and prosocial behavior in a school setting were examined in a cross-sectional study with 1688 7th and 8th graders in Germany who completed measures of violent media exposure and normative acceptance of aggression. For each participant,…

  15. Hurricane exposure and county fetal death rates, utilization of a county environmental quality index for confounding control.

    Science.gov (United States)

    The effects of natural disasters on public health are a rising concern, with increasing severity of disaster events. Many disaster studies utilize county-level analysis, however most do not control for county level environmental factors. Hurricane exposure during pregnancy could ...

  16. Effect of Ag additions on the lengthening rate of Ω plates and formation of σ phase in Al-Cu-Mg alloys during thermal exposure

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yaru; Liu, Zhiyi, E-mail: liuzhiyi@csu.edu.cn; Bai, Song; Ying, Puyou; Lin, Lianghua

    2017-01-15

    Effect of Ag additions on the mechanical properties and microstructures of the peak-aged Al-Cu-Mg alloys during prolonged thermal exposure at 150 °C, was investigated by tensile testing, conventional transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). The results showed that after exposure for 500 h, > 85% of the peak strength remained. Microstructure observations indicated that increasing the Ag content from 0.14 to 0.57% promoted the precipitation of a fine and uniform Ω phase and suppressed the formation of the θ′ phase, leading to a notable improvement of the strength properties and thermal stability of the studied alloys. Quantitative TEM analysis showed that the coarsening of Ω phase was predominated by plate lengthening rather than thickening, while its lengthening rate was independent of various Ag additions during exposure at 150 °C. In addition, an increase of Ag also facilitated the formation of a cubic σ phase, which was further supported by STEM results. - Highlights: •Increasing Ag improved strength properties and thermal stability of the alloys. •After exposure for 500 h, > 85% of the peak strength remained. •The lengthening rate of Ω plates remained constant as Ag increased at 150 °C. •Increasing Ag content facilitated the formation of σ phase.

  17. Is there a relationship between insect metabolic rate and mortality of mealworms Tenebrio molitor L. after insecticide exposure?

    OpenAIRE

    MALISZEWSKA, Justyna; TĘGOWSKA, Eugenia

    2016-01-01

    Pesticides are known to affect insects metabolic rate and CO2 release patterns. In the presented paper metabolic rate and mortality of mealworms Tenebrio molitor L. exposed to four different insecticides was evaluated, to find out whether there is a relationship between mealworms sensitivity to pesticides and their metabolic rate. Tenebrio molitor mortality was determined after intoxication with pyrethroid, oxadiazine, neonicotinoid and organophosphate. Metabolic rate before and after intoxic...

  18. Effects of inhibitors of DNA synthesis and protein synthesis on the rate of DNA synthesis after exposure of mammalian cells to ultraviolet light

    International Nuclear Information System (INIS)

    Griffiths, T.D.; Dahle, D.B.; Meechan, P.J.; Carpenter, J.G.

    1981-01-01

    Chinese hamster V-79 cells were treated with metabolic inhibitors of DNA or protein synthesis for various intervals of time after exposure of 3.0 or 5.0 J m -2 . After removal of the metabolic block(s) the rate of DNA synthesis was followed by measuring the incorporation of [ 14 C]thymidine into acid-insoluble material. A 2.5 or 5.0h incubation with cycloheximide or hydroxyurea was effective in delaying the onset of the recovery in the rate of DNA synthesis that normally becomes evident several hours after exposure to ultraviolet light. By using concentrations of cycloheximide or hydroxyurea that inhibit DNA synthesis by a similar amount (70%), but protein synthesis by vastly different amounts (95% for cycloheximide; 0% for hydroxyurea), it was apparent that the delay in recovery caused by the treatment of the cells with cycloheximide could be accounted for entirely by its inhibitory effect on DNA synthesis. This suggests that the recovery in DNA synthetic rates following exposure of V-79 cells to ultraviolet light does not appear to require de novo protein synthesis, and therefore does not appear to require the involvement of an inducible DNA repair process. (Auth.)

  19. Rates of preterm birth following antenatal exposure to severe life events: A population-based cohort study

    DEFF Research Database (Denmark)

    Khashan, Ali; McNamee, R.; Abel, Kathryn

    2009-01-01

    BACKGROUND: Preterm birth and other pregnancy complications have been linked to maternal stress during pregnancy. We investigated the association between maternal exposure to severe life events and risk of preterm birth. METHODS: Mothers of all singleton live births (n = 1.35 million births...... to estimate the effect of exposure on preterm birth, very preterm birth and extremely preterm birth. RESULTS: There were 58 626 (4.34%) preterm births (births and 3288 (0.24%) extremely preterm births in the study cohort. Severe life events in close relatives in the 6...... months before conception increased the risk of preterm birth by 16% (relative risk, RR = 1.16, [95% CI: 1.08-1.23]). Severe life events in older children in the 6 months before conception increased the risk of preterm birth by 23% (RR = 1.23, [95% CI: 1.02-1.49]) and the risk of very preterm birth by 59...

  20. Bovine spongiform encephalopathy: the effect of oral exposure dose on attack rate and incubation period in cattle ? an update

    OpenAIRE

    Konold, Timm; Arnold, Mark E; Austin, Anthony R; Cawthraw, Saira; Hawkins, Steve AC; Stack, Michael J; Simmons, Marion M; Sayers, A Robin; Dawson, Michael; Wilesmith, John W; Wells, Gerald AH

    2012-01-01

    Abstract Background To provide information on dose–response and aid in modelling the exposure dynamics of the BSE epidemic in the United Kingdom groups of cattle were exposed orally to a range of different doses of brainstem homogenate of known infectious titre from clinical cases of classical bovine spongiform encephalopathy (BSE). Interim data from this study was published in 2007. This communication documents additional BSE cases, which occurred subsequently, examines possible influence of...

  1. Biological effects of α-radiation exposure by 241Am in Arabidopsis thaliana seedlings are determined both by dose rate and 241Am distribution

    International Nuclear Information System (INIS)

    Biermans, Geert; Horemans, Nele; Vanhoudt, Nathalie; Vandenhove, Hildegarde; Saenen, Eline; Van Hees, May; Wannijn, Jean; Vangronsveld, Jaco; Cuypers, Ann

    2015-01-01

    Human activity has led to an increasing amount of radionuclides in the environment and subsequently to an increased risk of exposure of the biosphere to ionising radiation. Due to their high linear energy transfer, α-emitters form a threat to biota when absorbed or integrated in living tissue. Among these, 241 Am is of major concern due to high affinity for organic matter and high specific activity. This study examines the dose-dependent biological effects of α-radiation delivered by 241 Am at the morphological, physiological and molecular level in 14-day old seedlings of Arabidopsis thaliana after hydroponic exposure for 4 or 7 days. Our results show that 241 Am has high transfer to the roots but low translocation to the shoots. In the roots, we observed a transcriptional response of reactive oxygen species scavenging and DNA repair pathways. At the physiological and morphological level this resulted in a response which evolved from redox balance control and stable biomass at low dose rates to growth reduction, reduced transfer and redox balance decline at higher dose rates. This situation was also reflected in the shoots where, despite the absence of a transcriptional response, the control of photosynthesis performance and redox balance declined with increasing dose rate. The data further suggest that the effects in both organs were initiated in the roots, where the highest dose rates occurred, ultimately affecting photosynthesis performance and carbon assimilation. Though further detailed study of nutrient balance and 241 Am localisation is necessary, it is clear that radionuclide uptake and distribution is a major parameter in the global exposure effects on plant performance and health. - Highlights: • Arabidopsis thaliana was exposed hydroponically to a range of 241 Am concentrations. • Effects at molecular, morphological and physiological level were observed. • Effects were dependent on both dose rate and 241 Am distribution.

  2. Population growth rate and genetic variability of small and large populations of Red flour beetle (Tribolium castaneum) following multigenerational exposure to copper.

    Science.gov (United States)

    Laskowski, Ryszard; Radwan, Jacek; Kuduk, Katarzyna; Mendrok, Magdalena; Kramarz, Paulina

    2015-07-01

    We reared large (1000 individuals) and small (20 individuals) populations of Tribolium castaneum on diet contaminated with copper in order to determine if the size of a population affects its ability to adapt to adverse environmental conditions. After 10 generations, we used microsatellite markers to estimate and subsequently compare the genetic variability of the copper-treated populations with that of the control populations, which were reared on uncontaminated medium. Additionally, we conducted a full cross-factorial experiment which evaluated the effects of 10 generations of "pre-exposure" to copper on a population's fitness in control and copper-contaminated environments. In order to distinguish results potentially arising from genetic adaptation from those due to non-genetic effects associated to parental exposure to copper, we subjected also F11 generation, originating from parents not exposed to copper, to the same cross-factorial experiment. The effects of long-term exposure to copper depended on population size: the growth rates of small populations that were pre-exposed to copper were inhibited compared to those of small populations reared in uncontaminated environments. Large Cu-exposed populations had a higher growth rate in the F10 generation compared to the control groups, while the growth rate of the F11 generation was unaffected by copper exposure history. The only factor that had a significant effect on genetic variability was population size, but this was to be expected given the large difference in the number of individuals between large and small populations. Neither copper contamination nor its interaction with population size affected the number of microsatellite alleles retained in the F10 generation.

  3. Is there a relationship between insect metabolic rate and mortality of mealworms Tenebrio molitor L. after insecticide exposure?

    Directory of Open Access Journals (Sweden)

    Justyna MALISZEWSKA

    2016-09-01

    Full Text Available Pesticides are known to affect insects metabolic rate and CO2 release patterns. In the presented paper metabolic rate and mortality of mealworms Tenebrio molitor L. exposed to four different insecticides was evaluated, to find out whether there is a relationship between mealworms sensitivity to pesticides and their metabolic rate. Tenebrio molitor mortality was determined after intoxication with pyrethroid, oxadiazine, neonicotinoid and organophosphate. Metabolic rate before and after intoxication with insecticides was also determined. The highest CO2 production and mortality rate was observed after mealworms exposition to neonicotinoid insecticide. The results suggest that high CO2 release after intoxication is adequate to the intensity of the non-specific action of the xenobiotic (e.g. hyperactivity of neuromuscular system, rather than the intensity of detoxification processes, and it is correlated with mealworms mortality.

  4. Associations of baroreflex sensitivity, heart rate variability, and initial orthostatic hypotension with prenatal and recent postnatal methylmercury exposure in the Seychelles Child Development Study at age 19 years.

    Science.gov (United States)

    Périard, Daniel; Beqiraj, Bujar; Hayoz, Daniel; Viswanathan, Bharathi; Evans, Katie; Thurston, Sally W; Davidson, Philip W; Myers, Gary J; Bovet, Pascal

    2015-03-23

    A few studies have suggested an association between prenatal exposure to methylmercury and decreased heart rate variability (HRV) related to autonomic heart function, but no study has examined this association using baroreflex sensitivity (BRS). In this study we assessed the distribution of BRS and immediate orthostatic hypotension (IOH) in young Seychellois adults and their associations with exposure to prenatal and recent postnatal methylmercury. Subjects in the Seychelles Child Development Study (SCDS) main cohort were evaluated at age 19 years. Non-invasive beat-to-beat blood pressure (BP) monitoring (Finapres, Ohmeda) was performed at rest and during active standing in 95 consecutive subjects. Recent postnatal mercury exposure was measured in subjects' hair at the age of 19 years and prenatal exposure in maternal hair grown during pregnancy. BRS was estimated by sequence analysis to identify spontaneous ascending and descending BP ramps. HRV was estimated by the following markers: PNN50 (relative numbers of normal-to-normal intervals which are shorter by more than 50 ms than the immediately following normal-to-normal intervals); rMSSD (root mean of the squared sum of successive interval differences); LF/HF (low frequency/high frequency component ratio); ratio of the mean expiratory/inspiratory RR intervals (EI ratio); and the ratio between the longest RR interval 30 s after active standing and the shortest RR interval at 15 s (Max30/Min15). IOH was estimated by the deepest BP fall within the first 15 s after active standing up. Prenatal MeHg exposures were similar in boys and girls (6.7±4.3, 6.7±3.8 ng/g) but recent postnatal mercury levels were higher in males than females (11.2±5.8 vs 7.9±4.3 ng/g, p=0.003). Markers of autonomic heart rate control were within the normal range (BRS: 24.8±7 ms/mm Hg, PNN50: 24.9±6.8%, rMSSD: 68±22, LF/HF: 0.61±0.28) in both sexes. After standing, 51.4% of subjects had a transient systolic BP drop>40 mm Hg, but only 5

  5. Chronic Low Dose Rate Ionizing Radiation Exposure Induces Premature Senescence in Human Fibroblasts that Correlates with Up Regulation of Proteins Involved in Protection against Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Olga Loseva

    2014-07-01

    Full Text Available The risks of non-cancerous diseases associated with exposure to low doses of radiation are at present not validated by epidemiological data, and pose a great challenge to the scientific community of radiation protection research. Here, we show that premature senescence is induced in human fibroblasts when exposed to chronic low dose rate (LDR exposure (5 or 15 mGy/h of gamma rays from a 137Cs source. Using a proteomic approach we determined differentially expressed proteins in cells after chronic LDR radiation compared to control cells. We identified numerous proteins involved in protection against oxidative stress, suggesting that these pathways protect against premature senescence. In order to further study the role of oxidative stress for radiation induced premature senescence, we also used human fibroblasts, isolated from a patient with a congenital deficiency in glutathione synthetase (GS. We found that these GS deficient cells entered premature senescence after a significantly shorter time of chronic LDR exposure as compared to the GS proficient cells. In conclusion, we show that chronic LDR exposure induces premature senescence in human fibroblasts, and propose that a stress induced increase in reactive oxygen species (ROS is mechanistically involved.

  6. Effect of Short-Term Mobile Phone Base Station Exposure on Cognitive Performance, Body Temperature, Heart Rate and Blood Pressure of Malaysians.

    Science.gov (United States)

    Malek, F; Rani, K A; Rahim, H A; Omar, M H

    2015-08-19

    Individuals who report their sensitivity to electromagnetic fields often undergo cognitive impairments that they believe are due to the exposure of mobile phone technology. The aim of this study is to clarify whether short-term exposure at 1 V/m to the typical Global System for Mobile Communication and Universal Mobile Telecommunications System (UMTS) affects cognitive performance and physiological parameters (body temperature, blood pressure and heart rate). This study applies counterbalanced randomizing single blind tests to determine if sensitive individuals experience more negative health effects when they are exposed to base station signals compared with sham (control) individuals. The sample size is 200 subjects with 50.0% Idiopathic Environmental Intolerance attributed to electromagnetic fields (IEI-EMF) also known as sensitive and 50.0% (non-IEI-EMF). The computer-administered Cambridge Neuropsychological Test Automated Battery (CANTAB eclipse(TM)) is used to examine cognitive performance. Four tests are chosen to evaluate Cognitive performance in CANTAB: Reaction Time (RTI), Rapid Visual Processing (RVP), Paired Associates Learning (PAL) and Spatial Span (SSP). Paired sample t-test on the other hand, is used to examine the physiological parameters. Generally, in both groups, there is no statistical significant difference between the exposure and sham exposure towards cognitive performance and physiological effects (P's > 0.05).

  7. 22 CFR 201.67 - Maximum freight charges.

    Science.gov (United States)

    2010-04-01

    ..., commodity rate classification, quantity, vessel flag category (U.S.-or foreign-flag), choice of ports, and... the United States. (2) Maximum charter rates. (i) USAID will not finance ocean freight under any... owner(s). (4) Maximum liner rates. USAID will not finance ocean freight for a cargo liner shipment at a...

  8. Late biological effects of ionizing radiation as influenced by dose, dose rate, age at exposure, and genetic sensitivity to neoplastic transformation

    International Nuclear Information System (INIS)

    Spalding, J.F.; Prine, J.R.; Tietjen, G.L.

    1978-01-01

    A most comprehensive investigation is in progress at the Los Alamos Scientific Laboratory to study the late biological effects of whole-body exposure to gamma irradiation as they may be influenced by total dose, dose rate, age at exposure, and genetic background. Strain C57B1/6J mice of four age groups (newborn, 2, 6, and 15 months) were given five doses (20, 60, 180, 540, and 1620 rad) of gamma rays, with each dose being delivered at six dose rates (0.7, 2.1, 6.3, 18.9, 56.7 rad/day and 25 rad/min). Forty to sixty mice were used in each of the approximately 110 dose/dose-rate and age combinations. The study was done in two replications with an equal number of mice per replication. Strain RF/J mice were used in a companion study to investigate the influence of genetic background on the type and magnitude of effect. Results of the first and second replications of the 15-month-old age group and data on the influence of genetic background on biological response have been completed, and the results show no significant life shortening within the dose and dose-rate range used

  9. Late biological effects of ionizing radiation as influenced by dose, dose rate, age at exposure and genetic sensitivity to neoplastic transformation

    International Nuclear Information System (INIS)

    Spalding, J.F.; Prine, J.R.; Tietjen, G.L.

    1978-01-01

    A most comprehensive investigation is in progress at the Los Alamos Scientific Laboratory to study the late biological effects of whole-body exposure to gamma irradiation as they may be influenced by total dose, dose rate, age at exposure and genetic background. Strain C57B1/6J mice of four age groups (newborn, 2, 6 and l5 months) were given five doses (20, 60, 180, 540, and 1620 rads) of gamma rays, with each dose being delivered at six dose rates (0.7, 2.1, 6.3, 18.9, 56.7 rads/day and 25 rads/min). Forty to sixty mice were used in each of the approximately 119 dose/dose-rate and age combinations. The study was done in two replications with an equal number of mice per replicaton. Strain RF/J mice were used in a companion study to investigate the influence of genetic background on the type and magnitude of effect. Results of the first and second replications of the l5-month-old age group and data on the influence of genetic background on biological response have been completed, and the results show no significant life shortening within the dose and dose-rate range used. It was also concluded that radiaton-induced neoplastic transformaton was significantly greater in mice with a known genetic sensitivity to neoplastic disease than in mammals which do not normally have a significant incidence of tumours. (author)

  10. [Inhibition rate of gamma-aminolevulinic acid dehydratase activity in erythrocytes as a reliable index for individual workers of low lead exposure].

    Science.gov (United States)

    Hirano, H; Omichi, M; Ohishi, H; Ishikawa, K; Hirashima, N

    1983-09-01

    As the delta-aminolevulinic acid dehydratase (ALAD) activity in erythrocytes is decreased by lead exposure, we considered that a net reduction of ALAD activity by lead in blood should be the difference between the activity fully activated with zinc (Zn2+) and dithiothreitol (DTT) and that without activation. The optimal condition of activation of ALAD was found by addition of 0.25 mM of Zn2+ and 10 mM of DTT in the reaction mixture. Judging from our previous results that the amount of inhibition of ALAD activity can be represented as the rate of inhibition and is closely correlated with the dose of lead administered to rabbits, the inhibition rate of ALAD activity and lead content in blood (Pb-B) of lead workers were measured. The scatter diagram obtained from the inhibition rate and lead content in blood has two groups being divided at 50 micrograms/ml of Pb-B. In one group less than 50 micrograms/100 ml of Pb-B, the inhibition rate has been closely related to Pb-B., the regression equation being Y = 1.82 X + 11.7, and the correlation coefficient + 0.926. In another group more than 50 micrograms/100 ml of Pb-B the inhibition rate remained constant at the 90% level. Measurement of the inhibition rate suggests to have practical validity for monitoring lead exposure in workers, and by means of a nomograph lead content in blood can be estimated from the inhibition rate.

  11. Effect of field exposure to 38-year-old residual petroleum hydrocarbons on growth, condition index, and filtration rate of the ribbed mussel, Geukensia demissa

    International Nuclear Information System (INIS)

    Culbertson, Jennifer B.; Valiela, Ivan; Olsen, Ylva S.; Reddy, Christopher M.

    2008-01-01

    In September 1969, the Florida barge spilled 700,000 L of No. 2 fuel oil into the salt marsh sediments of Wild Harbor, MA. Today a substantial amount, approximately 100 kg, of moderately degraded petroleum remains within the sediment and along eroding creek banks. The ribbed mussels, Geukensia demissa, which inhabit the salt marsh creek bank, are exposed to the spilled oil. Examination of short-term exposure was done with transplantation of G. demissa from a control site, Great Sippewissett marsh, into Wild Harbor. We also examined the effects of long-term exposure with transplantation of mussels from Wild Harbor into Great Sippewissett. Both the short- and long-term exposure transplants exhibited slower growth rates, shorter mean shell lengths, lower condition indices, and decreased filtration rates. The results add new knowledge about long-term consequences of spilled oil, a dimension that should be included when assessing oil-impacted areas and developing management plans designed to restore, rehabilitate, or replace impacted areas. - Mussels exposed to petroleum in transplant and field experiments exhibited significant long-term effects

  12. Credal Networks under Maximum Entropy

    OpenAIRE

    Lukasiewicz, Thomas

    2013-01-01

    We apply the principle of maximum entropy to select a unique joint probability distribution from the set of all joint probability distributions specified by a credal network. In detail, we start by showing that the unique joint distribution of a Bayesian tree coincides with the maximum entropy model of its conditional distributions. This result, however, does not hold anymore for general Bayesian networks. We thus present a new kind of maximum entropy models, which are computed sequentially. ...

  13. The Influence of Puff Characteristics, Nicotine Dependence, and Rate of Nicotine Metabolism on Daily Nicotine Exposure in African American Smokers.

    Science.gov (United States)

    Ross, Kathryn C; Dempsey, Delia A; St Helen, Gideon; Delucchi, Kevin; Benowitz, Neal L

    2016-06-01

    African American (AA) smokers experience greater tobacco-related disease burden than Whites, despite smoking fewer cigarettes per day (CPD). Understanding factors that influence daily nicotine intake in AA smokers is an important step toward decreasing tobacco-related health disparities. One factor of interest is smoking topography, or the study of puffing behavior. (i) to create a model using puff characteristics, nicotine dependence, and nicotine metabolism to predict daily nicotine exposure, and (ii) to compare puff characteristics and nicotine intake from two cigarettes smoked at different times to ensure the reliability of the puff characteristics included in our model. Sixty AA smokers smoked their preferred brand of cigarette at two time points through a topography device. Plasma nicotine, expired CO, and changes in subjective measures were measured before and after each cigarette. Total nicotine equivalents (TNE) was measured from 24-hour urine collected during ad libitum smoking. In a model predicting daily nicotine exposure, total puff volume, CPD, sex, and menthol status were significant predictors (R(2) = 0.44, P smokers. Cancer Epidemiol Biomarkers Prev; 25(6); 936-43. ©2016 AACR. ©2016 American Association for Cancer Research.

  14. Late excretion rates of 226Ra and 210Pb following occupational or iatrogenic exposure. I. 226Ra

    International Nuclear Information System (INIS)

    Holtzman, R.B.; Sha, J.Y.; Markun, F.

    1982-01-01

    The urinary and fecal excretion rates of 226 Ra have been determined for 53 subjects who had been exposed to 226 Ra; 25 had been radium dial painters, 16 were iatrogenic (medical) cases and 12 were former radium chemists. The mean coefficient of elimination, CE (fraction of body content excreted annually), was significantly lower for the medical cases than for dial painters. The mean ratio of urinary-to-fecal excretion rates was 3.0 +- 0.7%

  15. Testing the effect of paraquat exposure on genomic recombination rates in queens of the western honey bee, Apis mellifera.

    Science.gov (United States)

    Langberg, Kurt; Phillips, Matthew; Rueppell, Olav

    2018-04-01

    The rate of genomic recombination displays evolutionary plasticity and can even vary in response to environmental factors. The western honey bee (Apis mellifera L.) has an extremely high genomic recombination rate but the mechanistic basis for this genome-wide upregulation is not understood. Based on the hypothesis that meiotic recombination and DNA damage repair share common mechanisms in honey bees as in other organisms, we predicted that oxidative stress leads to an increase in recombination rate in honey bees. To test this prediction, we subjected honey bee queens to oxidative stress by paraquat injection and measured the rates of genomic recombination in select genome intervals of offspring produced before and after injection. The evaluation of 26 genome intervals in a total of over 1750 offspring of 11 queens by microsatellite genotyping revealed several significant effects but no overall evidence for a mechanistic link between oxidative stress and increased recombination was found. The results weaken the notion that DNA repair enzymes have a regulatory function in the high rate of meiotic recombination of honey bees, but they do not provide evidence against functional overlap between meiotic recombination and DNA damage repair in honey bees and more mechanistic studies are needed.

  16. Influence of mercury exposure on blood pressure, resting heart rate and heart rate variability in French Polynesians: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Valera Beatriz

    2011-11-01

    Full Text Available Abstract Background Populations which diet is rich in seafood are highly exposed to contaminants such as mercury, which could affect cardiovascular risk factors Objective To assess the associations between mercury and blood pressure (BP, resting heart rate (HR and HR variability (HRV among French Polynesians Methods Data were collected among 180 adults (≥ 18 years and 101 teenagers (12-17 years. HRV was measured using a two-hour ambulatory electrocardiogram (Holter and BP was measured using a standardized protocol. The association between mercury and HRV and BP parameters was studied using analysis of variance (ANOVA and analysis of covariance (ANCOVA Results Among teenagers, the high frequency (HF decreased between the 2nd and 3rd tertile (380 vs. 204 ms2, p = 0.03 and a similar pattern was observed for the square root of the mean squared differences of successive R-R intervals (rMSSD (43 vs. 30 ms, p = 0.005 after adjusting for confounders. In addition, the ratio low/high frequency (LF/HF increased between the 2nd and 3rd tertile (2.3 vs. 3.0, p = 0.04. Among adults, the standard deviation of R-R intervals (SDNN tended to decrease between the 1st and 2nd tertile (84 vs. 75 ms, p = 0.069 after adjusting for confounders. Furthermore, diastolic BP tended to increase between the 2nd and 3rd tertile (86 vs. 91 mm Hg, p = 0.09. No significant difference was observed in resting HR or pulse pressure (PP Conclusions Mercury was associated with decreased HRV among French Polynesian teenagers while no significant association was observed with resting HR, BP, or PP among teenagers or adults

  17. Dietary intake rates during infancy and childhood: a data base for estimating human exposure to environmental pollutants

    International Nuclear Information System (INIS)

    Schwarz, G.; Kersting, M.

    1984-01-01

    A data base of food consumption rates for infants and children up to 14 years of age has been compiled for the purpose of evaluating the potential health hazard from ingestion of food containing various forms of environmental pollutants, e.g., radionuclides, heavy metals, and others. The analysis is based on a nutritional survey conducted in the city of Dortmund, FRG. The survey comprises data for 114 infants and 176 children. Within the framework of the study the data are discussed in terms of time-averaged daily consumption rates by individuals for various food categories, i.e., milk and milk products, meat, fish, cereals, vegetables, fruit, drinks, and related subgroups. Descriptive statistics of dietary intake rates by individuals have been tabulated for several age groups. (author)

  18. Egg Hatch Rate and Nymphal Survival of the Bed Bug (Hemiptera: Cimicidae) After Exposure to Insecticide Sprays.

    Science.gov (United States)

    Hinson, K R; Benson, E P; Zungoli, P A; Bridges, W C; Ellis, B R

    2016-12-01

    Few studies have addressed the efficacy of insecticides used against eggs and first-instar nymphs of the bed bug, Cimex lectularius L. (Hemiptera: Cimicidae). Insect eggs are often resistant to insecticides; therefore, information on which products are effective is important. We evaluated the efficacy of four commonly used insecticide sprays applied directly to bed bug eggs. We also evaluated the efficacy of these insecticides to first-instar nymphs exposed to residuals resulting from directly spraying eggs. Temprid SC (beta-cyfluthrin, imidacloprid) was the most effective insecticide at preventing egg hatch (13% hatch rate) for pyrethroid-resistant, field-strain (Jersey City) bed bugs compared with a control (water [99% hatch rate]), Bedlam (MGK-264, sumithrin [84% hatch rate]), Demand CS (lambda-cyhalothrin [91% hatch rate]), and Phantom SC (chlorfenapyr [95% hatch rate]). Demand CS and Temprid SC were most effective at preventing egg hatch (0%) for an insecticide-susceptible (Harold Harlan) strain, followed by Bedlam (28%). Phantom SC produced a hatch rate similar to the control (97% and 96%, respectively). Harold Harlan-strain nymphs showed 100% survival for the control but 0% survival for Bedlam and Phantom SC. Jersey City-strain nymphs showed 100% survival for the control, 99% survival for Bedlam, 0% survival for Demand CS, 4% survival for Phantom SC, and 38% survival for Temprid SC. Demand CS was less effective at preventing hatch (91% hatch rate) of Jersey City-strain nymphs but was the only product to kill all nymphs (0% survival). One of the least effective products for preventing Jersey City-strain egg hatch (Phantom SC, 95% hatch rate) was the second most effective at killing nymphs, leaving only six of 141 alive. These findings indicate that survival of directly sprayed eggs and residually exposed, first-instar nymphs varies by strain, life stage, and product used. © The Authors 2016. Published by Oxford University Press on behalf of Entomological

  19. Detection of low-level environmental exposure rates due to noble gas releases from the Muehleberg nuclear power plant

    International Nuclear Information System (INIS)

    Czarnecki, J.; Volkle, H.; Pretre, S.

    1980-01-01

    The increase of radiation doses in the vicinity of the Swiss Nuclear Power Stations due to airborne releases is generally expected to be below one mrem/year (about one percent of the natural radiation dose). To prove this expected rate, long term measurements with pressure ionization chambers in the vicinity of the Muhleberg plant (BWR) were conducted. Two of these chambers were installed at places where the greatest dose rates from the noble gas plumes were expected in the two prevailing wind directions. The local dose rates were continuously registered on magnetic tape to allow minicomputer evaluation. After the fuel change in the summer of 1976 the noble gas releases from Muhleberg dropped considerably. From that time the noble gas releases consisted of a very low continuous component and some rare short-time spike compoments resulting from turbine and reactor trips. The dose due to the low continuous component was determined by correlating the dose rates at the measuring points with the release measure--ments at the stack and with weather conditions, and by subtracting the natural background. The short noble gas spikes lasted from minutes to some hours and caused small dose rate increases which were easily measured with the ionization chambers, and usually amounted to doses of some microroentgens. By further correlating these dose peaks with wind direction and stack emission measurements, determination of short time atmospheric dilution factors for existing weather situations became possible. By this process, the very low annual environmental doses in the range of 1 mrem per year were determined. (author)

  20. Gamma exposure rate reduction and residual radium-226 concentrations resulting from decontamination activities conducted at the former uranium millsite in Shiprock, New Mexico

    International Nuclear Information System (INIS)

    Hans, J.M. Jr.; Hurst, T.L.

    1981-01-01

    Gamma radiation surveys and residual radium 226 soil samples were taken as part of the decontamination activities of the former Shiprock uranium mill site in New Mexico. In order to facilitate the decontamination activities, the mill site and its contaminated environs were divided into 6 major areas. Extensive data are presented in 2 appendices of the pre- and post-decontamination gamma ray exposure rates made on mill site, and of radium 226 concentrations in surface soil samples. A training program established on the mill site by the Navajo Engineering and Construction Authority is described

  1. The effect of low exposure-rate gamma irradiation on T and B lymphocyte function in the mouse

    International Nuclear Information System (INIS)

    McDermott, C.E.; Gengozian, N.

    1980-01-01

    The effect of chronic irradiation on T and B cell numbers and function was studied in mice. Cobalt 60 gamma radiation at 6 R/hour reduced the numbers of anti-SRBC PFC in the spleen, with minimal levels recorded after total exposures of 1000 to 2000 R. Recovery was incomplete after 1000 R, reaching only 40 to 50 per cent of normal in four months and remaining at that level for the animal's lifetime. The long-term deficiency in PFC formation was not due to a quantitative lack of T or B cells since normal cell numbers were observed in the spleen 60 to 144 days after 1000 R. Adoptive transfer studies with combinations of bone marrow and thymus cells, or of splenic T and B cells, from normal and irradiated mice, revealed functional defects in both cell compartments during the first two months. Normal and near normal function of T and B cells occurred 100 days postirradiation, a time when the splenic in vitro response was still only 50 per cent of the controls. The latter observation suggests that the microenvironment of the chronically irradiated spleen alters factors regulating T and B cell interactions in response to a T-dependent antigen. (author)

  2. Mutagenic potential scale developed for relative evaluation of biological system response to environments presenting different gamma exposure rates

    International Nuclear Information System (INIS)

    Nouailhetas, Yannick; Almeida, Carlos E. Bonacossa de; Mezrahi, Arnaldo; Shu, Jane; Xavier, Ana Maria

    1999-01-01

    The elaboration of a mutagenic potential scale (MPS) will be accomplished through the evaluation of the frequency of induced mutations in a plant biological system in different sites. The selection of these sites will be based on general public perception of risk to health. In this selection, it will include areas such ecological paradises and also neighborhoods of nuclear reactors and uranium mining and milling industry with potential radiological impact. The developed project foresees the contribution of other research groups that will also provide data from different sites. The referred scale will be built based on the response of the genetic system that gives color to the cells of Tradescantia (BNL 4430) stamen hair to mutagenic agents. Methodological improvements has been developed aiming the computerization of mutagenic events evaluation and statistical analysis of data that will significantly increase the efficiency of the system and obtention of results. Other biological systems of environmental quality are being added to the project, for future use. MPS should facilitate the general public and professionals of the nuclear area to understand risks, on a biological basis, of exposure from radiologically impacted environments. (author)

  3. Dose and dose rate extrapolation factors for malignant and non-malignant health endpoints after exposure to gamma and neutron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Van; Little, Mark P. [National Cancer Institute, Radiation Epidemiology Branch, Rockville, MD (United States)

    2017-11-15

    Murine experiments were conducted at the JANUS reactor in Argonne National Laboratory from 1970 to 1992 to study the effect of acute and protracted radiation dose from gamma rays and fission neutron whole body exposure. The present study reports the reanalysis of the JANUS data on 36,718 mice, of which 16,973 mice were irradiated with neutrons, 13,638 were irradiated with gamma rays, and 6107 were controls. Mice were mostly Mus musculus, but one experiment used Peromyscus leucopus. For both types of radiation exposure, a Cox proportional hazards model was used, using age as timescale, and stratifying on sex and experiment. The optimal model was one with linear and quadratic terms in cumulative lagged dose, with adjustments to both linear and quadratic dose terms for low-dose rate irradiation (<5 mGy/h) and with adjustments to the dose for age at exposure and sex. After gamma ray exposure there is significant non-linearity (generally with upward curvature) for all tumours, lymphoreticular, respiratory, connective tissue and gastrointestinal tumours, also for all non-tumour, other non-tumour, non-malignant pulmonary and non-malignant renal diseases (p < 0.001). Associated with this the low-dose extrapolation factor, measuring the overestimation in low-dose risk resulting from linear extrapolation is significantly elevated for lymphoreticular tumours 1.16 (95% CI 1.06, 1.31), elevated also for a number of non-malignant endpoints, specifically all non-tumour diseases, 1.63 (95% CI 1.43, 2.00), non-malignant pulmonary disease, 1.70 (95% CI 1.17, 2.76) and other non-tumour diseases, 1.47 (95% CI 1.29, 1.82). However, for a rather larger group of malignant endpoints the low-dose extrapolation factor is significantly less than 1 (implying downward curvature), with central estimates generally ranging from 0.2 to 0.8, in particular for tumours of the respiratory system, vasculature, ovary, kidney/urinary bladder and testis. For neutron exposure most endpoints, malignant and

  4. Influence of inocula with prior hydrocarbon exposure on biodegradation rates of diesel, synthetic diesel, and fish-biodiesel in soil.

    Science.gov (United States)

    Horel, Agota; Schiewer, Silke

    2014-08-01

    To achieve effective bioremediation within short warm seasons of cold climates, microbial adaptation periods to the contaminant should be brief. The current study investigated growth phases for soil spiked with diesel, Syntroleum, or fish biodiesel, using microbial inocula adapted to the specific substrates. For modeling hydrocarbon degradation, multi-phase first order kinetics was assumed, comparing linear regression with nonlinear parameter optimization of rate constants and phase durations. Lag phase periods of 5 to >28d were followed by short and intense exponential growth phases with high rate constants (e.g. from kFish=0.0013±0.0002 to kSyntr=0.015±0.001d(-1)). Hydrocarbon mineralization was highest for Syntroleum contamination, where up to three times higher cumulative CO2 production was achieved than for diesel fuel, with fish biodiesel showing initially the slowest degradation. The amount of hydrocarbons recovered from the soil by GC-MS decreased in the order fish biodiesel>diesel>Syntroleum. During initial weeks, biodegradation was higher for microbial inocula adapted to a specific fuel type, whereby the main effect of the inoculum was to shorten the lag phase duration; however, the inoculum's importance diminished after daily respiration peaked. In conclusion, addition of an inoculum to increase biodegradation rates was not necessary. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Exposure rates (versus time after administration), in relation with clinical factors, for thyroid carcinoma patients treated with Iodine-131

    International Nuclear Information System (INIS)

    Papadimitriou, D.; Oros, L.; Manetou, A.; Perris, A.; Molfetas, M.; Kottou, S.

    2002-01-01

    While the therapeutic use of iodine-131 for thyroid carcinoma patients offers enormous benefit to them, it contributes also significantly to the radiation exposure of individuals and population. A critical quantity for decisions relating radiation protection system based on restrictions recommended by authorities is the residual I-131 activity in patient's body. When this value is larger than a threshold level, it may keep the patient hospitalised for a short period of usually 2 to 3 days with an additional period of 7 days at home, where he must sleep separately and avoid close contact with other people. Essential for radiation protection issues is the careful collection of radioactive urine, radioactive waste and avoidance of any contaminations by perspiration and saliva. Longer hospital stay would increase the total cost of the treatment and limit the availability of the isolation room. So the patient has then to return home, having always in mind that in spite of the fast washout of the I-131 from his body, even the second week still contributes significantly to the total radiation burden to relatives and friends. Radiation hazards concerning relatives and friends can be kept to a truly negligible level (a small fraction of the annual dose limit of only 1mSv), only if it is provided that: a) reasonable standards of personal hygiene and cleanliness are followed, b) urine or saliva contaminations are avoided and c) patient's close contact with relatives or friends is kept to a minimum. These measures should be followed for a time period of 2-8 days after hospital discharge, a period that depends on administered and retained I-131 activity. This work tries to estimate the correlation between several clinical factors and the residual activity of I-131 in patient's body and proposes a method for a more simple measurement of the total body activity during patient's stay in the treatment centre - hospital

  6. Reduction of exposure to ultrafine particles by kitchen exhaust hoods: the effects of exhaust flow rates, particle size, and burner position.

    Science.gov (United States)

    Rim, Donghyun; Wallace, Lance; Nabinger, Steven; Persily, Andrew

    2012-08-15

    Cooking stoves, both gas and electric, are one of the strongest and most common sources of ultrafine particles (UFP) in homes. UFP have been shown to be associated with adverse health effects such as DNA damage and respiratory and cardiovascular diseases. This study investigates the effectiveness of kitchen exhaust hoods in reducing indoor levels of UFP emitted from a gas stove and oven. Measurements in an unoccupied manufactured house monitored size-resolved UFP (2 nm to 100 nm) concentrations from the gas stove and oven while varying range hood flow rate and burner position. The air change rate in the building was measured continuously based on the decay of a tracer gas (sulfur hexafluoride, SF(6)). The results show that range hood flow rate and burner position (front vs. rear) can have strong effects on the reduction of indoor levels of UFP released from the stove and oven, subsequently reducing occupant exposure to UFP. Higher range hood flow rates are generally more effective for UFP reduction, though the reduction varies with particle diameter. The influence of the range hood exhaust is larger for the back burner than for the front burner. The number-weighted particle reductions for range hood flow rates varying between 100 m(3)/h and 680 m(3)/h range from 31% to 94% for the front burner, from 54% to 98% for the back burner, and from 39% to 96% for the oven. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Near-term and late biological effects of acute and low-dose-rate continuous gamma-ray exposure in dogs and monkeys

    International Nuclear Information System (INIS)

    Spalding, J.F.; Holland, L.M.

    1979-07-01

    Monkeys (Macaca mulatta) and dogs (beagle) were given thirteen 100-rad gamma-ray doses at 28-day intervals. The comparative response (inury and recovery) of the hematopoietic system of the two species was observed at 7-day intervals during the exposure regime. At 84 days after the thirteenth gamma-ray dose, the 1300-rad conditioned and control dogs and monkeys were challenged continuously with gamma rays at 35 r/day until death to determine the amount of radiation-induced injry remaining in conditioned animals as a reduction in mean survival time. Dogs (50%) and monkeys (8%) died from injury incurred during conditioning exposures. Thus, the comparative response (in terms of lethality) of dogs and monkeys to dose protraction by acute dose fractionation was similar to what we would expect from a single acute dose. The mean survival times for nonconditioned dogs and monkeys during continuous exposure at 35 R/day were the same (approx. 1400 h). Thus, the hematopoietic response of the two species by this method of dose protraction was not significantly different. Mean survival times of conditioned dogs and monkeys during the continuous 35-R/day gamma-ray challenge exposure were greater (significant in dogs but not in monkeys) than for their control counterparts. Thus, long-term radiation-induced injury was not measurable by this method. Conditioning doses of more than 4 times the acute LD 50 30 in dogs and approximately 2 times that in monkeys served only to increase both mean survival time and variance in a gamma-ray stress environment with a dose rate of 35 Rat/day

  8. Does attenuated skin blood flow lower sweat rate and the critical environmental limit for heat balance during severe heat exposure?

    Science.gov (United States)

    Cramer, Matthew N; Gagnon, Daniel; Crandall, Craig G; Jay, Ollie

    2017-02-01

    What is the central question of this study? Does attenuated skin blood flow diminish sweating and reduce the critical environmental limit for heat balance, which indicates maximal heat loss potential, during severe heat stress? What is the main finding and its importance? Isosmotic hypovolaemia attenuated skin blood flow by ∼20% but did not result in different sweating rates, mean skin temperatures or critical environmental limits for heat balance compared with control and volume-infusion treatments, suggesting that the lower levels of skin blood flow commonly observed in aged and diseased populations may not diminish maximal whole-body heat dissipation. Attenuated skin blood flow (SkBF) is often assumed to impair core temperature (T c ) regulation. Profound pharmacologically induced reductions in SkBF (∼85%) lead to impaired sweating, but whether the smaller attenuations in SkBF (∼20%) more often associated with ageing and certain diseases lead to decrements in sweating and maximal heat loss potential is unknown. Seven healthy men (28 ± 4 years old) completed a 30 min equilibration period at 41°C and a vapour pressure (P a ) of 2.57 kPa followed by incremental steps in P a of 0.17 kPa every 6 min to 5.95 kPa. Differences in heat loss potential were assessed by identifying the critical vapour pressure (P crit ) at which an upward inflection in T c occurred. The following three separate treatments elicited changes in plasma volume to achieve three distinct levels of SkBF: control (CON); diuretic-induced isosmotic dehydration to lower SkBF (DEH); and continuous saline infusion to maintain SkBF (SAL). The T c , mean skin temperature (T sk ), heart rate, mean laser-Doppler flux (forearm and thigh; LDF mean ), mean local sweat rate (forearm and thigh; LSR mean ) and metabolic rate were measured. In DEH, a 14.2 ± 5.7% lower plasma volume resulted in a ∼20% lower LDF mean in perfusion units (PU) (DEH, 139 ± 23 PU; CON, 176 ± 22 PU; and SAL

  9. Assessment of exposure risk from hidden fungal growth by measurements of air change rates in construction cavities and living areas

    DEFF Research Database (Denmark)

    Knudsen, Sofie M; Møller, Eva B.; Gunnarsen, Lars Bo

    2017-01-01

    The transfer of particulate and gaseous pollution from hidden fungi growing on non-visible surfaces within the building envelope to occupied rooms is limited by the separating structure. Yet, growth, even in sealed construction cavities, is known to cause annoying smells and other more adverse...... health symptoms among the building occupants. This study analyses limitations of air change rate measurements in inaccessible construction cavities as well as analyses of the air exchange between living areas and accessible cavities such as crawl spaces and attics. It was necessary to invent a field...

  10. Effects of RF-EMF Exposure from GSM Mobile Phones on Proliferation Rate of Human Adipose-derived Stem Cells: An In-vitro Study

    Directory of Open Access Journals (Sweden)

    Shahbazi-Gahrouei D

    2016-12-01

    Full Text Available Background: As the use of mobile phones is increasing, public concern about the harmful effects of radiation emitted by these devices is also growing. In addition, protection questions and biological effects are among growing concerns which have remained largely unanswered. Stem cells are useful models to assess the effects of radiofrequency electromagnetic fields (RF-EMF on other cell lines. Stem cells are undifferentiated biological cells that can differentiate into specialized cells. Adipose tissue represents an abundant and accessible source of adult stem cells. The aim of this study is to investigate the effects of GSM 900 MHz on growth and proliferation of mesenchymal stem cells derived from adipose tissue within the specific distance and intensity. Materials and Methods: ADSCs were exposed to GSM mobile phones 900 MHz with intensity of 354.6 µW/cm2 square waves (217 Hz pulse frequency, 50% duty cycle, during different exposure times ranging from 6 to 21 min/day for 5 days at 20 cm distance from the antenna. MTT assay was used to determine the growth and metabolism of cells and trypan blue test was also done for cell viability. Statistical analyses were carried out using analysis of one way ANOVA. P<0.05 was considered to be statistically significant. Results: The proliferation rates of human ADSCs in all exposure groups were significantly lower than control groups (P<0.05 except in the group of 6 minutes/day which did not show any significant difference with control groups. Conclusion: The results show that 900 MHz RF signal radiation from antenna can reduce cell viability and proliferation rates of human ADSCs regarding the duration of exposure.

  11. Exposure to extremely low frequency (50 Hz electromagnetic field changes the survival rate and morphometric characteristics of neurosecretory neurons of the earthworm Eisenia foetida (Oligochaeta under illumination stress

    Directory of Open Access Journals (Sweden)

    Banovački Zorana

    2013-01-01

    Full Text Available An in vivo model was set up to establish the behavioral stress response (rate of survival and morphometric characteristics of A1 protocerebral neurosecretory neurons (cell size of Eisenia foetida (Oligochaeta as a result of the synergetic effect of extremely low frequency electromagnetic fields (ELF-EMF - 50 Hz, 50 μT, 17 V/m and 50 Hz, 150 μT, 17 V/m, respectively and constant illumination (420-450 lux. If combined, these two stressors significantly (p<0.05 increased the survival rate of E. foetida in the 150 μT-exposed animals, because of delayed caudal autotomy reflex, an indicator of stress response. In addition, morphometric analysis indicated that there were changes in the protocerebral neurosecretory cells after exposure to the ELF-EMF. The present data support the view that short-term ELF-EMF exposure in “windows” of intensity is likely to stimulate the immune and neuroendocrine response of E. foetida.

  12. Influence of the Sampling Rate and Noise Characteristics on Prediction of the Maximal Safe Laser Exposure in Human Skin Using Pulsed Photothermal Radiometry

    Science.gov (United States)

    Vidovič, L.; Milanič, M.; Majaron, B.

    2013-09-01

    Pulsed photothermal radiometry (PPTR) allows for noninvasive determination of the laser-induced temperature depth profile in strongly scattering samples, including human skin. In a recent experimental study, we have demonstrated that such information can be used to derive rather accurate predictions of the maximal safe radiant exposure on an individual patient basis. This has important implications for efficacy and safety of several laser applications in dermatology and aesthetic surgery, which are often compromised by risk of adverse side effects (e.g., scarring, and dyspigmentation) resulting from nonselective absorption of strong laser light in epidermal melanin. In this study, the differences between the individual maximal safe radiant exposure values as predicted from PPTR temperature depth profiling performed using a commercial mid-IR thermal camera (as used to acquire the original patient data) and our customized PPTR setup are analyzed. To this end, the latter has been used to acquire 17 PPTR records from three healthy volunteers, using 1 ms laser irradiation at 532 nm and a signal sampling rate of 20 000 . The laser-induced temperature profiles are reconstructed first from the intact PPTR signals, and then by binning the data to imitate the lower sampling rate of the IR camera (1000 fps). Using either the initial temperature profile in a dedicated numerical model of heat transfer or protein denaturation dynamics, the predicted levels of epidermal thermal damage and the corresponding are compared. A similar analysis is performed also with regard to the differences between noise characteristics of the two PPTR setups.

  13. The relationship of temperature rise to specific absorption rate and current in the human leg for exposure to electromagnetic radiation in the high frequency band

    International Nuclear Information System (INIS)

    Wainwright, P R

    2003-01-01

    Of the biological effects of human exposure to radiofrequency and microwave radiation, the best-established are those due to elevation of tissue temperature. To prevent harmful levels of heating, restrictions have been proposed on the specific absorption rate (SAR). However, the relationship between SAR and temperature rise is not an invariant, since not only the heat capacity but also the efficiency of heat dissipation varies between different tissues and exposure scenarios. For small enough SAR, the relationship is linear and may be characterized by a 'heating factor'. Under whole-body irradiation the SAR may be particularly high in the ankles due to the concentration of current flowing through a relatively small cross-sectional area. In a previous paper, the author has presented calculations of the SAR distribution in a human leg in the high frequency (HF) band. In this paper, the heating factor for this situation is derived using a finite element approximation of the Pennes bio-heat equation. The sensitivity of the results to different blood perfusion rates is investigated, and a simple local thermoregulatory model is applied. Both time-dependent and steady-state solutions are considered. Results confirm the appropriateness of the ICNIRP reference level of 100 mA on current through the leg, but suggest that at higher currents significant thermoregulatory adjustments to muscle blood flow will occur

  14. Natural terrestrial radiation exposure in Hong Kong. A survey on environmental gamma absorbed dose rate in air

    International Nuclear Information System (INIS)

    Wong, M.C.; Poon, H.T.; Chan, Y.K.; So, C.K.

    2000-01-01

    Hong Kong is a metropolitan city located on the southern coast of China with a population of some six million. About 90% of the population is concentrated in heavily built-up residential and commercial areas, which accounts for less than 50% of the total area in the territory. Hong Kong Observatory, 134A Nathan Road, Kowloon, Hong Kong, China. In order to understand the spatial variations in the environmental radiation levels in Hong Kong, the Hong Kong Observatory (HKO) in early 1999 conducted a study of the environmental gamma absorbed dose rate in air. The study combined data collected by the HKO radiation monitoring network (RMN) and data from a comprehensive territory-wide radiological survey conducted in January and February 1999. The RMN of ten stations each equipped with a Reuter-Stokes Model RSS-1013 HPIC has been in operation since 1987 to continuously monitor the environmental radiation levels over the territory as part of the emergency monitoring programme for response to nuclear accidents at a nearby nuclear power station. The terrestrial component of the environmental radiation field was estimated by subtracting from the measurements the cosmic contribution, which is determined to be about 39 nGy/h from measurements conducted over two large fresh water reservoirs. The RMN data with the long history was analysed to derive the seasonal variations in the environmental radiation levels. On average the environmental gamma absorbed dose rate in air in January and February is 1.03 times of the annual figure. This seasonal correction was applied to the results of the year 1999 survey. As the radiation field in the heavily built-up areas is enhanced by contribution from buildings, in the territory-wide survey measurements were made both in the open field and built-up areas. The territory of Hong Kong was divided into 42 grid boxes of 5 km x 5 km for open field and 61 grid boxes of 2.5 km x 2.5 km for built-up areas according to the population and land use. A

  15. Investigations of DNA damage induction and repair resulting from cellular exposure to high dose-rate pulsed proton beams

    International Nuclear Information System (INIS)

    Renis, M.; Malfa, G.; Tomasello, B.; Borghesi, M.; Schettino, G.; Favetta, M.; Romano, F.; Cirrone, G. A. P.; Manti, L.

    2013-01-01

    Studies regarding the radiobiological effects of low dose radiation, microbeam irradiation services have been developed in the world and today laser acceleration of protons and heavy ions may be used in radiation therapy. The application of different facilities is essential for studying bystander effects and relating signalling phenomena in different cells or tissues. In particular the use of ion beams results advantageous in cancer radiotherapy compared to more commonly used X-rays, since the ability of ions in delivering lethal amount of doses into the target tumour avoiding or limiting damage to the contiguous healthy tissues. At the INFN-LNS in Catania, a multidisciplinary radiobiology group is strategically structured aimed to develop radiobiological research, finalised to therapeutic applications, compatible with the use of high dose laser-driven ion beams. The characteristic non-continuous dose rates with several orders of magnitude of laser-driven ion beams makes this facility very interesting in the cellular systems' response to ultra-high dose rates with non-conventional pulse time intervals cellular studies. Our group have projected to examine the effect of high dose laser-driven ion beams on two cellular types: foetal fibroblasts (normal control cells) and DU145 (prostate cancer cells), studying the modulation of some different bio-molecular parameters, in particular cell proliferation and viability, DNA damage, redox cellular status, morphological alterations of both the cytoskeleton components and some cell organelles and the possible presence of apoptotic or necrotic cell death. Our group performed preliminary experiments with high energy (60 MeV), dose rate of 10 Gy/min, doses of 1, 2, 3 Gy and LET 1 keV/μm on human foetal fibroblasts (control cells). We observed that cell viability was not influenced by the characteristics of the beam, the irradiation conditions or the analysis time. Conversely, DNA damage was present at time 0, immediately

  16. Investigations of DNA damage induction and repair resulting from cellular exposure to high dose-rate pulsed proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Renis, M.; Malfa, G.; Tomasello, B. [Drug Sciences Department, University of Catania, Catania (Italy); Borghesi, M.; Schettino, G. [Queen' s University Belfast, Northern Ireland (United Kingdom); Favetta, M.; Romano, F.; Cirrone, G. A. P. [National Institute for Nuclear Physics (INFN-LNS), Catania (Italy); Manti, L. [Physics Science Department, University of Naples Federico II, Naples, and National Institute for Nuclear Physics (INFN), Naples (Italy)

    2013-07-26

    Studies regarding the radiobiological effects of low dose radiation, microbeam irradiation services have been developed in the world and today laser acceleration of protons and heavy ions may be used in radiation therapy. The application of different facilities is essential for studying bystander effects and relating signalling phenomena in different cells or tissues. In particular the use of ion beams results advantageous in cancer radiotherapy compared to more commonly used X-rays, since the ability of ions in delivering lethal amount of doses into the target tumour avoiding or limiting damage to the contiguous healthy tissues. At the INFN-LNS in Catania, a multidisciplinary radiobiology group is strategically structured aimed to develop radiobiological research, finalised to therapeutic applications, compatible with the use of high dose laser-driven ion beams. The characteristic non-continuous dose rates with several orders of magnitude of laser-driven ion beams makes this facility very interesting in the cellular systems' response to ultra-high dose rates with non-conventional pulse time intervals cellular studies. Our group have projected to examine the effect of high dose laser-driven ion beams on two cellular types: foetal fibroblasts (normal control cells) and DU145 (prostate cancer cells), studying the modulation of some different bio-molecular parameters, in particular cell proliferation and viability, DNA damage, redox cellular status, morphological alterations of both the cytoskeleton components and some cell organelles and the possible presence of apoptotic or necrotic cell death. Our group performed preliminary experiments with high energy (60 MeV), dose rate of 10 Gy/min, doses of 1, 2, 3 Gy and LET 1 keV/μm on human foetal fibroblasts (control cells). We observed that cell viability was not influenced by the characteristics of the beam, the irradiation conditions or the analysis time. Conversely, DNA damage was present at time 0, immediately

  17. Study and simulation of a multi-lithology stratigraphic model under maximum erosion rate constraint; Etude et simulation d'un modele statigraphique multi-lithologique sous contrainte de taux d'erosion maximal

    Energy Technology Data Exchange (ETDEWEB)

    Gervais, V.

    2004-11-01

    The subject of this report is the study and simulation of a model describing the infill of sedimentary basins on large scales in time and space. It simulates the evolution through time of the sediment layer in terms of geometry and rock properties. A parabolic equation is coupled to an hyperbolic equation by an input boundary condition at the top of the basin. The model also considers a unilaterality constraint on the erosion rate. In the first part of the report, the mathematical model is described and particular solutions are defined. The second part deals with the definition of numerical schemes and the simulation of the model. In the first chap-ter, finite volume numerical schemes are defined and studied. The Newton algorithm adapted to the unilateral constraint used to solve the schemes is given, followed by numerical results in terms of performance and accuracy. In the second chapter, a preconditioning strategy to solve the linear system by an iterative solver at each Newton iteration is defined, and numerical results are given. In the last part, a simplified model is considered in which a variable is decoupled from the other unknowns and satisfies a parabolic equation. A weak formulation is defined for the remaining coupled equations, for which the existence of a unique solution is obtained. The proof uses the convergence of a numerical scheme. (author)

  18. Bystander effects of exposure to low-dose-rate 125I seeds on human lung cancers cells in vitro

    International Nuclear Information System (INIS)

    Jia Rongfei; Chen Honghong; Yu Lei; Zhao Meijia; Shao Chunlin; Cheng Wenying

    2007-01-01

    The bystander effects induced by continuous low-dose-rate (LDR) 125 I seeds radiation on damage of human lung cancer cells were investigated. Human adenocarcinoma cell line A549 and human small cell lung cancer cell line NCI-H446, which have different sensitivities to high-dose rate (HDR) external irradiation, were exposed directly to 125 I seeds in vitro and co-cultured with unirradiated cells for 24 h. Using cytokinesis-blocking micronucleus method and γ H2AX fluorescence immunoassay, bystander effects induced by 2Gy and 4Gy 125 I seed irradiation on micronucleus formation and DNA double-strand breaks (DSBs) of human lung cancer cells were detected and evaluated. The results showed that irradiation with 125 I seeds can induce medium-mediated bystander effects in A549 cells and NCI-H446 cells, exhibiting that both micronuclei formation and γ H2AX focus formation in bystander cells were increased significantly compared with non-irradiated cells. The extent of DNA damage induced by bystander effects was correlated with accumulated radiation dose and radiosensitive of tumor cells. NCI-H446 cells that were sensitive to HDR γ irradiation were more sensitive to continuous LDR irradiation and bystander effects than A549. However, a comparison between the bystander effects and direct effects elicits the intensity of bystander responses of A549 cells was higher than that of NCI-H446 cells. A dose-related reduction in bystander responses was observed both in A549 cells and NCI-H446 cells, suggesting that the signaling factors involved in the bystander signaling pathways may decrease with the increase of cell damages. (authors)

  19. Associations of Baroreflex Sensitivity, Heart Rate Variability, and Initial Orthostatic Hypotension with Prenatal and Recent Postnatal Methylmercury Exposure in the Seychelles Child Development Study at Age 19 Years

    Directory of Open Access Journals (Sweden)

    Daniel Périard

    2015-03-01

    Full Text Available Background: A few studies have suggested an association between prenatal exposure to methylmercury and decreased heart rate variability (HRV related to autonomic heart function, but no study has examined this association using baroreflex sensitivity (BRS. In this study we assessed the distribution of BRS and immediate orthostatic hypotension (IOH in young Seychellois adults and their associations with exposure to prenatal and recent postnatal methylmercury. Methods: Subjects in the Seychelles Child Development Study (SCDS main cohort were evaluated at age 19 years. Non-invasive beat-to-beat blood pressure (BP monitoring (Finapres, Ohmeda was performed at rest and during active standing in 95 consecutive subjects. Recent postnatal mercury exposure was measured in subjects’ hair at the age of 19 years and prenatal exposure in maternal hair grown during pregnancy. BRS was estimated by sequence analysis to identify spontaneous ascending and descending BP ramps. HRV was estimated by the following markers: PNN50 (relative numbers of normal-to-normal intervals which are shorter by more than 50 ms than the immediately following normal-to-normal intervals; rMSSD (root mean of the squared sum of successive interval differences; LF/HF (low frequency/high frequency component ratio; ratio of the mean expiratory/inspiratory RR intervals (EI ratio; and the ratio between the longest RR interval 30 s after active standing and the shortest RR interval at 15 s (Max30/Min15. IOH was estimated by the deepest BP fall within the first 15 s after active standing up. Results: Prenatal MeHg exposures were similar in boys and girls (6.7 ± 4.3, 6.7 ± 3.8 ng/g but recent postnatal mercury levels were higher in males than females (11.2 ± 5.8 vs 7.9 ± 4.3 ng/g, p = 0.003. Markers of autonomic heart rate control were within the normal range (BRS: 24.8 ± 7 ms/mm Hg, PNN50: 24.9 ± 6.8%, rMSSD: 68 ± 22, LF/HF: 0.61 ± 0.28 in both sexes. After standing, 51.4% of subjects

  20. Associations of Baroreflex Sensitivity, Heart Rate Variability, and Initial Orthostatic Hypotension with Prenatal and Recent Postnatal Methylmercury Exposure in the Seychelles Child Development Study at Age 19 Years

    Science.gov (United States)

    Périard, Daniel; Beqiraj, Bujar; Hayoz, Daniel; Viswanathan, Bharathi; Evans, Katie; Thurston, Sally W.; Davidson, Philip W.; Myers, Gary J.; Bovet, Pascal

    2015-01-01

    Background: A few studies have suggested an association between prenatal exposure to methylmercury and decreased heart rate variability (HRV) related to autonomic heart function, but no study has examined this association using baroreflex sensitivity (BRS). In this study we assessed the distribution of BRS and immediate orthostatic hypotension (IOH) in young Seychellois adults and their associations with exposure to prenatal and recent postnatal methylmercury. Methods: Subjects in theSeychelles Child Development Study (SCDS) main cohort were evaluated at age 19 years. Non-invasive beat-to-beat blood pressure (BP) monitoring (Finapres, Ohmeda) was performed at rest and during active standing in 95 consecutive subjects. Recent postnatal mercury exposure was measured in subjects’ hair at the age of 19 years and prenatal exposure in maternal hair grown during pregnancy. BRS was estimated by sequence analysis to identify spontaneous ascending and descending BP ramps. HRV was estimated by the following markers: PNN50 (relative numbers of normal-to-normal intervals which are shorter by more than 50 ms than the immediately following normal-to-normal intervals); rMSSD (root mean of the squared sum of successive interval differences); LF/HF (low frequency/high frequency component ratio); ratio of the mean expiratory/inspiratory RR intervals (EI ratio); and the ratio between the longest RR interval 30 s after active standing and the shortest RR interval at 15 s (Max30/Min15). IOH was estimated by the deepest BP fall within the first 15 s after active standing up. Results: Prenatal MeHg exposures were similar in boys and girls (6.7 ± 4.3, 6.7 ± 3.8 ng/g) but recent postnatal mercury levels were higher in males than females (11.2 ± 5.8 vs 7.9 ± 4.3 ng/g, p = 0.003). Markers of autonomic heart rate control were within the normal range (BRS: 24.8 ± 7 ms/mm Hg, PNN50: 24.9 ± 6.8%, rMSSD: 68 ± 22, LF/HF: 0.61 ± 0.28) in both sexes. After standing, 51.4% of subjects had a

  1. Compilation of Published PM2.5 Emission Rates for Cooking, Candles and Incense for Use in Modeling of Exposures in Residences

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Tianchao [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Logue, Jennifer M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-08-01

    recent analysis of health impacts from air pollutant inhalation in homes found that PM2.5 is the most damaging at the population level. Chronic exposure to elevated PM2.5 has the potential to damage human respiratory systems, and may result in premature death. PM2.5 exposures in homes can be mitigated through various approaches including kitchen exhaust ventilation, filtration, indoor pollutant source reduction and designing ventilation systems to reduce the entry of PM2.5 from outdoors. Analysis of the potential benefits and costs of various approaches can be accomplished using computer codes that simulate the key physical processes including emissions, dilution and ventilation. The largest sources of PM2.5 in residences broadly are entry from outdoors and emissions from indoor combustion. The largest indoor sources are tobacco combustion (smoking), cooking and the burning of candles and incense. Data on the magnitude of PM2.5 and other pollutant emissions from these events and processes are required to conduct simulations for analysis. The goal of this study was to produce a database of pollutant emission rates associated with cooking and the burning of candles and incense. The target use of these data is for indoor air quality modeling.

  2. Distinct Effects of Nalmefene on Dopamine Uptake Rates and Kappa Opioid Receptor Activity in the Nucleus Accumbens Following Chronic Intermittent Ethanol Exposure

    Directory of Open Access Journals (Sweden)

    Jamie H. Rose

    2016-07-01

    Full Text Available The development of pharmacotherapeutics that reduce relapse to alcohol drinking in patients with alcohol dependence is of considerable research interest. Preclinical data support a role for nucleus accumbens (NAc κ opioid receptors (KOR in chronic intermittent ethanol (CIE exposure-induced increases in ethanol intake. Nalmefene, a high-affinity KOR partial agonist, reduces drinking in at-risk patients and relapse drinking in rodents, potentially due to its effects on NAc KORs. However, the effects of nalmefene on accumbal dopamine transmission and KOR function are poorly understood. We investigated the effects of nalmefene on dopamine transmission and KORs using fast scan cyclic voltammetry in NAc brain slices from male C57BL/6J mice following five weeks of CIE or air exposure. Nalmefene concentration-dependently reduced dopamine release similarly in air and CIE groups, suggesting that dynorphin tone may not be present in brain slices. Further, nalmefene attenuated dopamine uptake rates to a greater extent in brain slices from CIE-exposed mice, suggesting that dopamine transporter-KOR interactions may be fundamentally altered following CIE. Additionally, nalmefene reversed the dopamine-decreasing effects of a maximal concentration of a KOR agonist selectively in brain slices of CIE-exposed mice. It is possible that nalmefene may attenuate withdrawal-induced increases in ethanol consumption by modulation of dopamine transmission through KORs.

  3. Distinct Effects of Nalmefene on Dopamine Uptake Rates and Kappa Opioid Receptor Activity in the Nucleus Accumbens Following Chronic Intermittent Ethanol Exposure

    Science.gov (United States)

    Rose, Jamie H.; Karkhanis, Anushree N.; Steiniger-Brach, Björn; Jones, Sara R.

    2016-01-01

    The development of pharmacotherapeutics that reduce relapse to alcohol drinking in patients with alcohol dependence is of considerable research interest. Preclinical data support a role for nucleus accumbens (NAc) κ opioid receptors (KOR) in chronic intermittent ethanol (CIE) exposure-induced increases in ethanol intake. Nalmefene, a high-affinity KOR partial agonist, reduces drinking in at-risk patients and relapse drinking in rodents, potentially due to its effects on NAc KORs. However, the effects of nalmefene on accumbal dopamine transmission and KOR function are poorly understood. We investigated the effects of nalmefene on dopamine transmission and KORs using fast scan cyclic voltammetry in NAc brain slices from male C57BL/6J mice following five weeks of CIE or air exposure. Nalmefene concentration-dependently reduced dopamine release similarly in air and CIE groups, suggesting that dynorphin tone may not be present in brain slices. Further, nalmefene attenuated dopamine uptake rates to a greater extent in brain slices from CIE-exposed mice, suggesting that dopamine transporter-KOR interactions may be fundamentally altered following CIE. Additionally, nalmefene reversed the dopamine-decreasing effects of a maximal concentration of a KOR agonist selectively in brain slices of CIE-exposed mice. It is possible that nalmefene may attenuate withdrawal-induced increases in ethanol consumption by modulation of dopamine transmission through KORs. PMID:27472317

  4. The impacts of short-term exposure to noise and traffic-related air pollution on heart rate variability in young healthy adults.

    Science.gov (United States)

    Huang, Jing; Deng, Furong; Wu, Shaowei; Lu, Henry; Hao, Yu; Guo, Xinbiao

    2013-01-01

    Traffic-related air pollution and noise are associated with cardiovascular diseases, and alternation of heart rate variability (HRV), which reflects cardiac autonomic function, is one of the mechanisms. However, few studies considered the impacts of noise when exploring associations between air pollution and HRV. We explored whether noise modifies associations between short-term exposure to traffic-related air pollution and HRV in young healthy adults. In this randomized, crossover study, 40 young healthy adults stayed for 2 h in a traffic center and, on a separate occasion, in a park. Personal exposure to traffic-related air pollutants and noise were measured and ambulatory electrocardiogram was performed. Effects were estimated using mixed-effects regression models. Traffic-related air pollution and noise were both associated with HRV, and effects of air pollutants were amplified at high noise level (>65.6 A-weighted decibels (dB[A])) compared with low noise level (≤ 65.6 dB[A]). High frequency (HF) decreased by -4.61% (95% confidence interval, -6.75% to-2.42%) per 10 μg/m(3) increment in fine particle (PM2.5) at 5-min moving average, but effects became insignificant at low noise level (P>0.05). Similar effects modification was observed for black carbon (BC) and carbon monoxide (CO). We conclude that noise is an important factor influencing the effects of air pollution on HRV.

  5. Effect of high altitude exposure on the hemodynamics of the bidirectional Glenn physiology: modeling incremented pulmonary vascular resistance and heart rate.

    Science.gov (United States)

    Vallecilla, Carolina; Khiabani, Reza H; Sandoval, Néstor; Fogel, Mark; Briceño, Juan Carlos; Yoganathan, Ajit P

    2014-06-03

    The considerable blood mixing in the bidirectional Glenn (BDG) physiology further limits the capacity of the single working ventricle to pump enough oxygenated blood to the circulatory system. This condition is exacerbated under severe conditions such as physical activity or high altitude. In this study, the effect of high altitude exposure on hemodynamics and ventricular function of the BDG physiology is investigated. For this purpose, a mathematical approach based on a lumped parameter model was developed to model the BDG circulation. Catheterization data from 39 BDG patients at stabilized oxygen conditions was used to determine baseline flows and pressures for the model. The effect of high altitude exposure was modeled by increasing the pulmonary vascular resistance (PVR) and heart rate (HR) in increments up to 80% and 40%, respectively. The resulting differences in vascular flows, pressures and ventricular function parameters were analyzed. By simultaneously increasing PVR and HR, significant changes (p fails to overcome the increased preload and implied low oxygenation in BDG patients at higher altitudes, especially for those with high baseline PVRs. The presented mathematical model provides a framework to estimate the hemodynamic performance of BDG patients at different PVR increments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    60, No. 3. — journal of. March 2003 physics pp. 415–422. Maximum stellar iron core mass. F W GIACOBBE. Chicago Research Center/American Air Liquide ... iron core compression due to the weight of non-ferrous matter overlying the iron cores within large .... thermal equilibrium velocities will tend to be non-relativistic.

  7. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore. 11 refs., 4 figs

  8. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore

  9. A portable storage maximum thermometer

    International Nuclear Information System (INIS)

    Fayart, Gerard.

    1976-01-01

    A clinical thermometer storing the voltage corresponding to the maximum temperature in an analog memory is described. End of the measurement is shown by a lamp switch out. The measurement time is shortened by means of a low thermal inertia platinum probe. This portable thermometer is fitted with cell test and calibration system [fr

  10. Cumulative and current exposure to potentially nephrotoxic antiretrovirals and development of chronic kidney disease in HIV-positive individuals with a normal baseline estimated glomerular filtration rate

    DEFF Research Database (Denmark)

    Mocroft, Amanda; Lundgren, Jens D; Ross, Michael

    2016-01-01

    BACKGROUND: Whether or not the association between some antiretrovirals used in HIV infection and chronic kidney disease is cumulative is a controversial topic, especially in patients with initially normal renal function. In this study, we aimed to investigate the association between duration...... of exposure to antiretrovirals and the development of chronic kidney disease in people with initially normal renal function, as measured by estimated glomerular filtration rate (eGFR). METHODS: In this prospective international cohort study, HIV-positive adult participants (aged ≥16 years) from the D......:A:D study (based in Europe, the USA, and Australia) with first eGFR greater than 90 mL/min per 1·73 m(2) were followed from baseline (first eGFR measurement after Jan 1, 2004) until the occurrence of one of the following: chronic kidney disease; last eGFR measurement; Feb 1, 2014; or final visit plus 6...

  11. Neutron spectra unfolding with maximum entropy and maximum likelihood

    International Nuclear Information System (INIS)

    Itoh, Shikoh; Tsunoda, Toshiharu

    1989-01-01

    A new unfolding theory has been established on the basis of the maximum entropy principle and the maximum likelihood method. This theory correctly embodies the Poisson statistics of neutron detection, and always brings a positive solution over the whole energy range. Moreover, the theory unifies both problems of overdetermined and of underdetermined. For the latter, the ambiguity in assigning a prior probability, i.e. the initial guess in the Bayesian sense, has become extinct by virtue of the principle. An approximate expression of the covariance matrix for the resultant spectra is also presented. An efficient algorithm to solve the nonlinear system, which appears in the present study, has been established. Results of computer simulation showed the effectiveness of the present theory. (author)

  12. Estimates of Health Detriments and Tissue Weighting Factors for Hong Kong Populations from Low Dose, Low Dose Rate and Low LET Ionising Radiation Exposure

    International Nuclear Information System (INIS)

    Lee, S.K.

    1998-01-01

    The total health detriments and the tissue weighting factors for the Hong Kong populations from low dose, low dose rate and low LET ionising radiation exposure are obtained according to the methodology recommended in ICRP Publication 60. The probabilities of fatal cancers for the general (ages 0-90) and working (ages 20-64) populations due to lifetime exposure at low dose and low dose rate are 4.9 x 10 -2 Sv -1 and 3.6 x 10 -2 Sv -1 respectively, comparing with the ICRP 60 estimates of 5.0 x 10 -2 Sv -1 and 4.0 x 10 -2 Sv -1 . The corresponding total health detriments for the general and working populations are 6.9 x 10 -2 Sv -1 and 4.9 x 10 -2 Sv -1 respectively comparing with the ICRP 60 estimates of 7.3 x 10 -2 Sv -1 and 5.6 x 10 -2 Sv -1 . Tissue weighting factors for the general population are 0.01 (bone surface and skin), 0.02 (liver, oesophagus and thyroid), 0.04 (bladder and breast), 0.08 (remainder), 0.10 (stomach), 0.11 (bone marrow), 0.15 (colon), 0.19 (lung) and 0.21 (gonads) and for the working population are 0.01 (bone surface and skin), 0.03 (liver, oesophagus and thyroid), 0.04 (breast), 0.06 (remainder), 0.07 (bladder), 0.08 (colon), 0.14 (bone marrow and stomach), 0.16 (lung) and 0.20 (gonads). (author)

  13. The effects of fasting and cold exposure on metabolic rate and mitochondrial proton leak in liver and skeletal muscle of an amphibian, the cane toad Bufo marinus.

    Science.gov (United States)

    Trzcionka, M; Withers, K W; Klingenspor, M; Jastroch, M

    2008-06-01

    Futile cycling of protons across the mitochondrial inner membrane contributes significantly to standard metabolic rate in a variety of ectothermic and endothermic animals, but adaptations of the mitochondrial bioenergetics to different environmental conditions have rarely been studied in ectotherms. Changes in ambient temperature and nutritional status have a great effect on the physiological demands of ectothermic amphibians and may require the adjustment of mitochondrial efficiency. In order to investigate the effect of temperature and nutritional status on the mitochondrial level, we exposed male cane toads to either 10 degrees C or 30 degrees C and fasted half of the animals in each group. Cold exposure resulted in a fourfold reduction of the resting metabolic rate whereas nutritional status had only minor effects. The mitochondrial adjustments to each condition were observed by comparing the proton leak kinetics of isolated liver and skeletal muscle mitochondria at 25 degrees C. In response to cold exposure, liver mitochondria showed a decrease in proton conductance while skeletal muscle mitochondria were unchanged. Additional food deprivation had minor effects in skeletal muscle, but in liver we uncovered surprising differences in energy saving mechanisms between the acclimation temperatures: in warm-acclimated toads, fasting resulted in a decrease of the proton conductance whereas in cold-acclimated toads, the activity of the respiratory chain was reduced. To investigate the molecular mechanism underlying mitochondrial proton leakage, we determined the adenine-nucleotide transporter (ANT) content, which explained tissue-specific differences in the basal proton leak, but neither the ANT nor uncoupling protein (UCP) gene expression correlated with alterations of the proton leak in response to physiological stimuli.

  14. Ice-based altitude distribution of natural radiation annual exposure rate in the Antarctica zone over the latitude range 69 degrees S-77 degrees S using a pair-filter thermoluminescence method.

    Science.gov (United States)

    Nakajima, T; Kamiyama, T; Fujii, Y; Motoyama, H; Esumi, S

    1995-12-01

    Both ice-based altitude distributions of natural ionizing radiation exposure and the quasi-effective energy of natural radiation over Antartica over the latitude range 69 degrees S - 77 degrees S during approx. 500 days were measured using thermoluminescent dosimeters. The results shows that dependence on altitude above sea level of the exposure rate increases by almost three-fold with each increase of 2000 m of altitude, thus deviating from the general rule stating that the exposure rate should double with each 2000 m. Although the exposure rate shows a dependence on altitude, altitude dependence of the quasi-effective energy of natural radiation over Antartica is not observed. In the present study it is observed that natural radiation occurring over the ice base of Antartica consists mainly of cosmic rays.

  15. Ice-based altitude distribution of natural radiation annual exposure rate in the Antarctica zone over the latitude range 69 deg S-77 deg S using a pair-filter thermoluminescence method

    International Nuclear Information System (INIS)

    Nakajima, Toshiyuki; Kamiyama, Takayoshi; Fujii, Yoshiyuki; Motoyama, Hideaki; Esumi, Shuuichi

    1995-01-01

    Both ice-based altitude distributions of natural ionizing radiation exposure and the quasi-effective energy of natural radiation over Antarctica over the latitude range 69 o S-77 o S during approx. 500 days were measured using thermoluminescent dosimeters. The results shows that dependence on altitude above sea level of the exposure rate increases by almost three-fold with each increase of 2000 m of altitude, thus deviating from the general rule stating that the exposure rate should double with each 2000 m. Although the exposure rate shows a dependence on altitude, altitude dependence of the quasi-effective energy of natural radiation over Antarctica is not observed. In the present study it is observed that natural radiation occurring over the ice base of Antarctica consists mainly of cosmic rays. (Author)

  16. Nitric-glycolic flowsheet testing for maximum hydrogen generation rate

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site is developing for implementation a flowsheet with a new reductant to replace formic acid. Glycolic acid has been tested over the past several years and found to effectively replace the function of formic acid in the DWPF chemical process. The nitric-glycolic flowsheet reduces mercury, significantly lowers the chemical generation of hydrogen and ammonia, allows purge reduction in the Sludge Receipt and Adjustment Tank (SRAT), stabilizes the pH and chemistry in the SRAT and the Slurry Mix Evaporator (SME), allows for effective adjustment of the SRAT/SME rheology, and is favorable with respect to melter flammability. The objective of this work was to perform DWPF Chemical Process Cell (CPC) testing at conditions that would bound the catalytic hydrogen production for the nitric-glycolic flowsheet.

  17. veteran athletes exercise at higher maximum heart rates than

    African Journals Online (AJOL)

    HR responses in different sporting disciplines." All tests were performed in the ... blood pressure (BP) and HR were measured from the right arm while the subjects were in a supine and standing position. Diastolic BP (DBP) was defined as the ...

  18. On Maximum Entropy and Inference

    Directory of Open Access Journals (Sweden)

    Luigi Gresele

    2017-11-01

    Full Text Available Maximum entropy is a powerful concept that entails a sharp separation between relevant and irrelevant variables. It is typically invoked in inference, once an assumption is made on what the relevant variables are, in order to estimate a model from data, that affords predictions on all other (dependent variables. Conversely, maximum entropy can be invoked to retrieve the relevant variables (sufficient statistics directly from the data, once a model is identified by Bayesian model selection. We explore this approach in the case of spin models with interactions of arbitrary order, and we discuss how relevant interactions can be inferred. In this perspective, the dimensionality of the inference problem is not set by the number of parameters in the model, but by the frequency distribution of the data. We illustrate the method showing its ability to recover the correct model in a few prototype cases and discuss its application on a real dataset.

  19. Maximum Water Hammer Sensitivity Analysis

    OpenAIRE

    Jalil Emadi; Abbas Solemani

    2011-01-01

    Pressure waves and Water Hammer occur in a pumping system when valves are closed or opened suddenly or in the case of sudden failure of pumps. Determination of maximum water hammer is considered one of the most important technical and economical items of which engineers and designers of pumping stations and conveyance pipelines should take care. Hammer Software is a recent application used to simulate water hammer. The present study focuses on determining significance of ...

  20. Maximum Gene-Support Tree

    Directory of Open Access Journals (Sweden)

    Yunfeng Shan

    2008-01-01

    Full Text Available Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single gene trees of seven yeast species as well as single gene trees of nine baculovirus species using all the orthologous genes among the species compared. Homologous genes among seven known plants were used for validation of the finding. Four algorithms—maximum parsimony (MP, minimum evolution (ME, maximum likelihood (ML, and neighbor-joining (NJ—were used. Trees were reconstructed before and after weighting the DNA and protein sequence lengths among genes. Rarely a gene can always generate the “true tree” by all the four algorithms. However, the most frequent gene tree, termed “maximum gene-support tree” (MGS tree, or WMGS tree for the weighted one, in yeasts, baculoviruses, or plants was consistently found to be the “true tree” among the species. The results provide insights into the overall degree of divergence of orthologous genes of the genomes analyzed and suggest the following: 1 The true tree relationship among the species studied is still maintained by the largest group of orthologous genes; 2 There are usually more orthologous genes with higher similarities between genetically closer species than between genetically more distant ones; and 3 The maximum gene-support tree reflects the phylogenetic relationship among species in comparison.

  1. Study of the examination times using radiation equipments and the radiation exposure control

    Energy Technology Data Exchange (ETDEWEB)

    Koshida, Kichiro; Orito, Takeo; Maekawa, Ryuichi; Hiraki, Tatsunosuke [Kanazawa Univ. (Japan). School of Paramedicine; Koga, Sukehiko

    1985-01-01

    The relation between the examination time and the exposure to the personnel was investigated. In order to minimize radiation injury, special exposure dose-rate distribution curves were performed at the maximum exposure condition setting the phantom, and the examination times could be limited from the exprosure dose for the place where the personnel presented. The examination times are possible to be ten times by those with the Medical X-ray Protective Aprons.

  2. Study of the examination times using radiation equipments and the radiation exposure control

    International Nuclear Information System (INIS)

    Koshida, Kichiro; Orito, Takeo; Maekawa, Ryuichi; Hiraki, Tatsunosuke; Koga, Sukehiko.

    1985-01-01

    It was investigated for the relation between the examination times and the exposure to the personnel. At the purpose to minimize the radiation injury, the special exposure dose-rate distribution curves were performed at the maximum exposure condition setting the phantom, and the examination times could be limited from the exprosure dose for the place where the personnel presented. The examination times are possible to be ten times by those with the Medical X-ray Protective Aprons. (author)

  3. LCLS Maximum Credible Beam Power

    International Nuclear Information System (INIS)

    Clendenin, J.

    2005-01-01

    The maximum credible beam power is defined as the highest credible average beam power that the accelerator can deliver to the point in question, given the laws of physics, the beam line design, and assuming all protection devices have failed. For a new accelerator project, the official maximum credible beam power is determined by project staff in consultation with the Radiation Physics Department, after examining the arguments and evidence presented by the appropriate accelerator physicist(s) and beam line engineers. The definitive parameter becomes part of the project's safety envelope. This technical note will first review the studies that were done for the Gun Test Facility (GTF) at SSRL, where a photoinjector similar to the one proposed for the LCLS is being tested. In Section 3 the maximum charge out of the gun for a single rf pulse is calculated. In Section 4, PARMELA simulations are used to track the beam from the gun to the end of the photoinjector. Finally in Section 5 the beam through the matching section and injected into Linac-1 is discussed

  4. Transient receptor potential cation channel A1 (TRPA1) mediates changes in heart rate variability following a single exposure to acrolein in mice

    Science.gov (United States)

    The data show that a single exposure to acrolein causes autonomic imbalance in mice through the TRPA1 sensor and subsequent cardiac dysfunction. Human and animal studies have shown that short-term air pollution exposure causes...

  5. Acrolein-Induced Increases in Blood Pressure and Heart Rate Are Coupled with Decreased Blood Oxygen Levels During Exposure in Hypertensive Rats

    Science.gov (United States)

    Exposure to air pollution increases the risk of cardiovascular morbidity and mortality, especially in individuals with pre-existing cardiovascular disease. Recent studies link exposure to air pollution with reduced blood oxygen saturation suggesting that hypoxia is a potential me...

  6. New constraints on slip rates of the Fodongmiao-Hongyazi fault in the Northern Qilian Shan, NE Tibet, from the 10Be exposure dating of offset terraces

    Science.gov (United States)

    Yang, Haibo; Yang, Xiaoping; Huang, Xiongnan; Li, An; Huang, Weiliang; Zhang, Ling

    2018-01-01

    The Fodongmo-Hongyazi fault (FHF) is a major thrust of Northeastern Tibet, bounding the Qilian Shan. It accommodates crustal shortening across this region and has produced a strong historical earthquake. Until now the slip rate has been poorly constrained, limiting our understanding of its role in the accommodation of deformation across this region. In this paper, faulted terraces at two sites on the western and middle segments of the FHF were mapped with satellite imagery and field observations. Chronological constraints are placed on the ages of displaced river terraces at these sites using terrestrial cosmogenic nuclide (TCN) exposure dating. These ages combined with offsets measured from SPOT 6 DEM's yield average vertical slip rates of 1.3 ± 0.1 mm/yr for the western segment since ∼207 ka and 0.9 ± 0.1 mm/yr since ∼46 ka for the middle segment. These data suggest that the FHF accommodates ∼15-20% of the total shortening across the Qilian Shan (5.5-7 mm/yr). In addition, comparisons of our data with published slip rates along the Northern Qilian Thrust Fault Zone show that the fastest tectonic uplift occurs along the western portion of the Northern Qilian Shan. This is consistent with estimates deduced from geomorphology. The western portion of the Qilian Shan is mainly controlled by compressional deformation produced by the northward movement of the Northeastern Tibetan Plateau, while the eastern Qilian Shan is mainly controlled by the eastward extrusion of material along the left-lateral Haiyuan strike-slip Fault.

  7. Are radiosensitivity data derived from natural field conditions consistent with data from controlled exposures? A case study of Chernobyl wildlife chronically exposed to low dose rates.

    Science.gov (United States)

    Garnier-Laplace, J; Geras'kin, S; Della-Vedova, C; Beaugelin-Seiller, K; Hinton, T G; Real, A; Oudalova, A

    2013-07-01

    The discrepancy between laboratory or controlled conditions ecotoxicity tests and field data on wildlife chronically exposed to ionising radiation is presented for the first time. We reviewed the available chronic radiotoxicity data acquired in contaminated fields and used a statistical methodology to support the comparison with knowledge on inter-species variation of sensitivity to controlled external γ irradiation. We focus on the Chernobyl Exclusion Zone and effects data on terrestrial wildlife reported in the literature corresponding to chronic dose rate exposure situations (from background ~100 nGy/h up to ~10 mGy/h). When needed, we reconstructed the dose rate to organisms and obtained consistent unbiased data sets necessary to establish the dose rate-effect relationship for a number of different species and endpoints. Then, we compared the range of variation of radiosensitivity of species from the Chernobyl-Exclusion Zone with the statistical distribution established for terrestrial species chronically exposed to purely gamma external irradiation (or chronic Species radioSensitivity Distribution - SSD). We found that the best estimate of the median value (HDR50) of the distribution established for field conditions at Chernobyl (about 100 μGy/h) was eight times lower than the one from controlled experiments (about 850 μGy/h), suggesting that organisms in their natural environmental were more sensitive to radiation. This first comparison highlights the lack of mechanistic understanding and the potential confusion coming from sampling strategies in the field. To confirm the apparent higher sensitive of wildlife in the Chernobyl Exclusion Zone, we call for more a robust strategy in field, with adequate design to deal with confounding factors. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. The rate of repeating X-rays in the medical centers of Jenin District/Palestine and how to reduce patient exposure to radiation

    Science.gov (United States)

    Assi, Abed Al Nasser

    2018-03-01

    Reduction of the patient's received radiation dose to as low as reasonably achievable (ALARA) is based on recommendations of radiation protection organizations such as the International Commission on Radiological Protection (ICRP) and the National Radiological Protection Board (NRPB). The aim of this study was to explore the frequency and characteristics of rejected / repeated radiographic films in governmental and private centers in Jenin city. The radiological centers were chosen based on their high volume of radiographic studies. The evaluation was carried out over a period of four months. The collected data were compiled at the end of each week and entered into a computer for analysis at the end of study. Overall 5000 films (images) were performed in four months, The average repeat rate of radiographic images was 10% (500 films). Repetition rate was the same for both thoracic and abdominal images (42%). The main reason for repeating imaging was inadequate imaging quality (58.2%) and poor film processing (38%). Human error was the most likely reason necessitating the repetition of the radiographs (48 %). Infant and children groups comprised 85% of the patient population that required repetition of the radiographic studies. In conclusion, we have a higher repetition rate of imaging studies compared to the international standards (10% vs. 4-6%, respectively). This is especially noticeable in infants and children, and mainly attributed to human error in obtaining and processing images. This is an important issue that needs to be addressed on a national level due to the ill effects associated with excessive exposure to radiation especially in children, and to reduce cost of the care delivered.

  9. Respiratory effects of commuters' exposure to air pollution in traffic.

    Science.gov (United States)

    Zuurbier, Moniek; Hoek, Gerard; Oldenwening, Marieke; Meliefste, Kees; van den Hazel, Peter; Brunekreef, Bert

    2011-03-01

    Much time is spent in traffic, especially during rush hours, when air pollution concentrations on roads are relatively high. Controlled exposure studies have shown acute respiratory effects of short, high exposures to air pollution from motor vehicles. Acute health effects of lower real-life exposures in traffic are unclear. Exposures of 34 healthy, nonsmoking adult volunteers were repeatedly measured while commuting for 2 hours by bus, car, or bicycle. Particle number (PN), particulate matter (PM2.5 and PM10), and soot exposures were measured. Lung function and airway resistance were measured directly before, directly following, and 6 hours after exposure. Exhaled nitric oxide (NO) was measured directly before and 6 hours after exposure. Inhaled doses were estimated based on monitored heart rates. Mixed models were used to analyze effects of exposure on changes in health parameters after exposure compared with before. PN, PM10, and soot were associated with decreased peak expiratory flow directly following but not 6 hours after exposure. PN doses were associated with decreases in maximum midexpiratory flow and forced expiratory flow (FEV1) 6 hours after exposure, whereas PN and soot exposures were associated with increased maximum midexpiratory flow and FEV1 directly after exposure. PN and soot were associated with increased exhaled NO after car and bus but not bicycle trips. PN was also associated with an increase in airway resistance directly following exposure but not 6 hours later. We found modest effects of 2-hour in-traffic exposure to air pollutants on peak flow, exhaled NO, and airway resistance.

  10. Generic maximum likely scale selection

    DEFF Research Database (Denmark)

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

    2007-01-01

    in this work is on applying this selection principle under a Brownian image model. This image model provides a simple scale invariant prior for natural images and we provide illustrative examples of the behavior of our scale estimation on such images. In these illustrative examples, estimation is based......The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...

  11. ORIGINAL ARTICLES Surgical practice in a maximum security prison

    African Journals Online (AJOL)

    Prison Clinic, Mangaung Maximum Security Prison, Bloemfontein. F Kleinhans, BA (Cur) .... HIV positivity rate and the use of the rectum to store foreign objects. ... fruit in sunlight. Other positive health-promoting factors may also play a role,.

  12. A comparison of the diminution rates of lead in blood and lead mobilized by CaEDTA after termination of occupational exposure: a long-term observation in two lead workers.

    Science.gov (United States)

    Araki, S; Murata, K; Aono, H; Yanagihara, S; Ushio, K

    1983-07-01

    CaEDTA 20 mg/kg was administered weekly for 3.5 years after termination of occupational exposure to two lead workers. The diminution half-lives for lead in blood and urine lead mobilized by CaEDTA were 4.8 and 3.3 years respectively for subject 1 following 28 years exposure and 3.3 and 2.0 years respectively for subject 2 following 26 years exposure. The difference in the diminution rate between lead in blood and lead mobilized by CaEDTA was significant in subject 2 (p less than 0.05).

  13. Extreme Maximum Land Surface Temperatures.

    Science.gov (United States)

    Garratt, J. R.

    1992-09-01

    There are numerous reports in the literature of observations of land surface temperatures. Some of these, almost all made in situ, reveal maximum values in the 50°-70°C range, with a few, made in desert regions, near 80°C. Consideration of a simplified form of the surface energy balance equation, utilizing likely upper values of absorbed shortwave flux (1000 W m2) and screen air temperature (55°C), that surface temperatures in the vicinity of 90°-100°C may occur for dry, darkish soils of low thermal conductivity (0.1-0.2 W m1 K1). Numerical simulations confirm this and suggest that temperature gradients in the first few centimeters of soil may reach 0.5°-1°C mm1 under these extreme conditions. The study bears upon the intrinsic interest of identifying extreme maximum temperatures and yields interesting information regarding the comfort zone of animals (including man).

  14. Noise exposure alters long-term neural firing rates and synchrony in primary auditory and rostral belt cortices following bimodal stimulation.

    Science.gov (United States)

    Takacs, Joseph D; Forrest, Taylor J; Basura, Gregory J

    2017-12-01

    We previously demonstrated that bimodal stimulation (spinal trigeminal nucleus [Sp5] paired with best frequency tone) altered neural tone-evoked and spontaneous firing rates (SFRs) in primary auditory cortex (A1) 15 min after pairing in guinea pigs with and without noise-induced tinnitus. Neural responses were enhanced (+10 ms) or suppressed (0 ms) based on the bimodal pairing interval. Here we investigated whether bimodal stimulation leads to long-term (up to 2 h) changes in tone-evoked and SFRs and neural synchrony (correlate of tinnitus) and if the long-term bimodal effects are altered following noise exposure. To obviate the effects of permanent hearing loss on the results, firing rates and neural synchrony were measured three weeks following unilateral (left ear) noise exposure and a temporary threshold shift. Simultaneous extra-cellular single-unit recordings were made from contralateral (to noise) A1 and dorsal rostral belt (RB); an associative auditory cortical region thought to influence A1, before and after bimodal stimulation (pairing intervals of 0 ms; simultaneous Sp5-tone and +10 ms; Sp5 precedes tone). Sixty and 120 min after 0 ms pairing tone-evoked and SFRs were suppressed in sham A1; an effect only preserved 120 min following pairing in noise. Stimulation at +10 ms only affected SFRs 120 min after pairing in sham and noise-exposed A1. Within sham RB, pairing at 0 and +10 ms persistently suppressed tone-evoked and SFRs, while 0 ms pairing in noise markedly enhanced tone-evoked and SFRs up to 2 h. Together, these findings suggest that bimodal stimulation has long-lasting effects in A1 that also extend to the associative RB that is altered by noise and may have persistent implications for how noise damaged brains process multi-sensory information. Moreover, prior to bimodal stimulation, noise damage increased neural synchrony in A1, RB and between A1 and RB neurons. Bimodal stimulation led to persistent changes in neural synchrony in

  15. Cancer incidence among a cohort of subjects exposed to low-dose rate chronic radiation exposure in utero and after birth in the techa riverbank villages

    International Nuclear Information System (INIS)

    Ostroumova, E.V.; Akleyev, A.V.; Akleyev, A.V.; Hall, P.

    2003-01-01

    As a result of releases of liquid radioactive waste by the Mayak Production Association (PA) into the Techa River since 1949 till 1956 the population of the Riverside villages was exposed to a protracted effect of combined (external and internal) radiation. The 1-st-generation offspring of exposed residents born on 01.01.1950 and later were exposed both in utero and after birth. In all, 46 cancer cases, including 4 cases of leukemia, were registered among the study cohort members numbering 7,890 subjects born in the Techa Riverside villages in the Chelyabinsk province over the period since 1950 till 1998. No significant differences were noted in cancer incidence rates between men and women. Cancer incidence in the offspring's cohort was by 30-35% higher compared with the unexposed population of the USSR and Russia, the differences, however, are statistically insignificant. No influence of the parents total gonadal dose on cancer development in offspring was observed. The positive dose-effect dependence of cancer incidence on both antenatal and postnatal exposure was traced

  16. Concentration and chemical status of arsenic in the blood of pregnant hamsters during critical embryogenesis. 1. Subchronic exposure to arsenate utilizing constant rate administration

    Energy Technology Data Exchange (ETDEWEB)

    Hanlon, D.P.; Ferm, V.H.

    1986-08-01

    The concentration, availability, and chemical status of radiolabeled arsenic has been determined in the blood of pregnant hamsters at the beginning (morning of Day 8) and the end (morning of Day 9) of the critical period of embryogenesis. Hamster dams were exposed to teratogenic doses of arsenate by means of osmotic minipumps implanted on the morning of Day 6 of the gestation period. Whole blood arsenic concentrations were the same for 48 and 72 hr postimplant. The arsenic concentration of plasma equaled that of red cells. Plasma arsenic was not bound to macromolecules and had the same chemical status 48 and 72 hr postimplant. Arsenate was the dominant form (67% of the total). However, the presence of dimethylarsinic acid and arsenite indicates that the pentavalent species was metabolized. Red cell arsenic was bound to macromolecules in the cell sap. Seventy percent of red cell sap arsenic was dialyzable 48 hr postimplant, but only 56% 72 hr postimplant. Arsenate was the dominant dialyzable red cell species on Day 8 and arsenite was the major dialyzable form on Day 9. The authors findings demonstrate a relationship between the maternal blood concentration and chemical status of arsenic and the presence of malformations resulting from a constant rate exposure of pregnant hamsters to arsenate via the osmotic minipump.

  17. Concentration and chemical status of arsenic in the blood of pregnant hamsters during critical embryogenesis. 1. Subchronic exposure to arsenate utilizing constant rate administration

    International Nuclear Information System (INIS)

    Hanlon, D.P.; Ferm, V.H.

    1986-01-01

    The concentration, availability, and chemical status of radiolabeled arsenic has been determined in the blood of pregnant hamsters at the beginning (morning of Day 8) and the end (morning of Day 9) of the critical period of embryogenesis. Hamster dams were exposed to teratogenic doses of arsenate by means of osmotic minipumps implanted on the morning of Day 6 of the gestation period. Whole blood arsenic concentrations were the same for 48 and 72 hr postimplant. The arsenic concentration of plasma equaled that of red cells. Plasma arsenic was not bound to macromolecules and had the same chemical status 48 and 72 hr postimplant. Arsenate was the dominant form (67% of the total). However, the presence of dimethylarsinic acid and arsenite indicates that the pentavalent species was metabolized. Red cell arsenic was bound to macromolecules in the cell sap. Seventy percent of red cell sap arsenic was dialyzable 48 hr postimplant, but only 56% 72 hr postimplant. Arsenate was the dominant dialyzable red cell species on Day 8 and arsenite was the major dialyzable form on Day 9. The authors findings demonstrate a relationship between the maternal blood concentration and chemical status of arsenic and the presence of malformations resulting from a constant rate exposure of pregnant hamsters to arsenate via the osmotic minipump

  18. System for memorizing maximum values

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1992-08-01

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

  19. Remarks on the maximum luminosity

    Science.gov (United States)

    Cardoso, Vitor; Ikeda, Taishi; Moore, Christopher J.; Yoo, Chul-Moon

    2018-04-01

    The quest for fundamental limitations on physical processes is old and venerable. Here, we investigate the maximum possible power, or luminosity, that any event can produce. We show, via full nonlinear simulations of Einstein's equations, that there exist initial conditions which give rise to arbitrarily large luminosities. However, the requirement that there is no past horizon in the spacetime seems to limit the luminosity to below the Planck value, LP=c5/G . Numerical relativity simulations of critical collapse yield the largest luminosities observed to date, ≈ 0.2 LP . We also present an analytic solution to the Einstein equations which seems to give an unboundedly large luminosity; this will guide future numerical efforts to investigate super-Planckian luminosities.

  20. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-09-07

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  1. Scintillation counter, maximum gamma aspect

    International Nuclear Information System (INIS)

    Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  2. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yi; Zhao, Shiguang; Gao, Xin

    2014-01-01

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  3. Damage to the testes of a marine fish, the plaice (Pleuronectes platessa), induced by chronic exposure to low dose rate radiation

    International Nuclear Information System (INIS)

    Knowles, J.F.

    1999-01-01

    Although most authorised disposals of liquid radioactive waste are to the sea, effects of chronic radiation exposure on reproductive endpoints in a marine fish have not so far been investigated. For this reason we have carried out a series of experiments into effects of chronic radiation exposure on plaice, a commercially important marine food species which spends much of its life in contact with sea bed sediments where exposure from radioactive contaminants have been shown to be highest

  4. Very low frequency oscillations in the power spectra of heart rate variability during dry supine immersion and exposure to non-hypoxic hypobaria.

    Science.gov (United States)

    Tripathi, K K

    2011-06-01

    The origin of very low frequency (VLF) oscillations in the power spectra of heart rate variability (HRV) is controversial with possible mechanisms involving thermoregulation and/or renin-angiotensin-aldosterone system. Recently, a major contribution from vagal influences has been suggested. The present study investigated the behaviour of VLF (0.004-0.040 Hz) components of HRV power spectra in a group of healthy male volunteers during their exposure to (1) dry, supine, immersion in thermo-neutral water for 6 h (n = 7) and (2) non-hypoxic hypobaria (breathing 40-60% oxygen at 15,000' simulated in a decompression chamber) for 5 h (n = 15). The two manoeuvres are established to increase vagal outflow. During both the manoeuvres, all the frequency domain indices of HRV exhibited a significant increase. Increase in HRV was much more than that in the R-R interval. At 6 h of immersion, the R-R interval increased by ∼ 15% but the total power increased ∼ fourfold. Similarly, at 5 h of exposure to hypobaria, total power increased ∼ twofold with a very modest increase in an R-R of ∼ 9%. Increase in spectral power was appreciable even after normalization with mean R-R(2). Increase in VLF during immersion was more than reported during enalaprilat blockade of angiotensin convertase enzyme. Plasma renin activity did not vary during hypobaria. There was a significant increase in pNN50, an established marker of cardiac vagal activity. Centre frequencies of the spectra and slope (β) of the relation between log(PSD) and log(frequency) did not change. Results were supportive of the notion that the parasympathetic system is pre-potent to influence slower (than respiratory) frequency components in HRV spectrum. Additionally, such an effect was without a change in the time constant of effector responses or pacemaker frequencies of VLF and LF periodicities and HRV was not a simple linear surrogate for cardiac vagal effects. An invariance of spectral exponent (β) ruled out

  5. Monitoring Of Radiation Exposure Source In PPTA Serpong

    International Nuclear Information System (INIS)

    Th, Rina; M, Subiharto

    2000-01-01

    The radiation exposure in the of P PTA Serpone was measured by means of MCA micro nomad. The computer codes NAGABAT was used for analyzing the contribution of natural gamma rays to the exposure rate in the measuring locations. Measurement was taken for 14 locations, under conditions that the nuclear facilities are not in operation. The result showed that the exposure varieties, dependently on potassium, uranium and thorium contents in the environment matrix. The maximum of thorium, uranium and potassium are in amount of 5,269 ppm; 1,650 ppm; and respectively 0,72 %

  6. Maximum entropy and Bayesian methods

    International Nuclear Information System (INIS)

    Smith, C.R.; Erickson, G.J.; Neudorfer, P.O.

    1992-01-01

    Bayesian probability theory and Maximum Entropy methods are at the core of a new view of scientific inference. These 'new' ideas, along with the revolution in computational methods afforded by modern computers allow astronomers, electrical engineers, image processors of any type, NMR chemists and physicists, and anyone at all who has to deal with incomplete and noisy data, to take advantage of methods that, in the past, have been applied only in some areas of theoretical physics. The title workshops have been the focus of a group of researchers from many different fields, and this diversity is evident in this book. There are tutorial and theoretical papers, and applications in a very wide variety of fields. Almost any instance of dealing with incomplete and noisy data can be usefully treated by these methods, and many areas of theoretical research are being enhanced by the thoughtful application of Bayes' theorem. Contributions contained in this volume present a state-of-the-art overview that will be influential and useful for many years to come

  7. The power and robustness of maximum LOD score statistics.

    Science.gov (United States)

    Yoo, Y J; Mendell, N R

    2008-07-01

    The maximum LOD score statistic is extremely powerful for gene mapping when calculated using the correct genetic parameter value. When the mode of genetic transmission is unknown, the maximum of the LOD scores obtained using several genetic parameter values is reported. This latter statistic requires higher critical value than the maximum LOD score statistic calculated from a single genetic parameter value. In this paper, we compare the power of maximum LOD scores based on three fixed sets of genetic parameter values with the power of the LOD score obtained after maximizing over the entire range of genetic parameter values. We simulate family data under nine generating models. For generating models with non-zero phenocopy rates, LOD scores maximized over the entire range of genetic parameters yielded greater power than maximum LOD scores for fixed sets of parameter values with zero phenocopy rates. No maximum LOD score was consistently more powerful than the others for generating models with a zero phenocopy rate. The power loss of the LOD score maximized over the entire range of genetic parameters, relative to the maximum LOD score calculated using the correct genetic parameter value, appeared to be robust to the generating models.

  8. Evaluation of regulatory variation and theoretical health risk for pesticide maximum residue limits in food.

    Science.gov (United States)

    Li, Zijian

    2018-08-01

    To evaluate whether pesticide maximum residue limits (MRLs) can protect public health, a deterministic dietary risk assessment of maximum pesticide legal exposure was conducted to convert global MRLs to theoretical maximum dose intake (TMDI) values by estimating the average food intake rate and human body weight for each country. A total of 114 nations (58% of the total nations in the world) and two international organizations, including the European Union (EU) and Codex (WHO) have regulated at least one of the most currently used pesticides in at least one of the most consumed agricultural commodities. In this study, 14 of the most commonly used pesticides and 12 of the most commonly consumed agricultural commodities were identified and selected for analysis. A health risk analysis indicated that nearly 30% of the computed pesticide TMDI values were greater than the acceptable daily intake (ADI) values; however, many nations lack common pesticide MRLs in many commonly consumed foods and other human exposure pathways, such as soil, water, and air were not considered. Normality tests of the TMDI values set indicated that all distributions had a right skewness due to large TMDI clusters at the low end of the distribution, which were caused by some strict pesticide MRLs regulated by the EU (normally a default MRL of 0.01 mg/kg when essential data are missing). The Box-Cox transformation and optimal lambda (λ) were applied to these TMDI distributions, and normality tests of the transformed data set indicated that the power transformed TMDI values of at least eight pesticides presented a normal distribution. It was concluded that unifying strict pesticide MRLs by nations worldwide could significantly skew the distribution of TMDI values to the right, lower the legal exposure to pesticide, and effectively control human health risks. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Evaluation of the contribution of contamination of radiotherapy room surfaces in the measure of exposure rate of radioiodine therapy patients; Avaliacao da contribuicao da contaminacao de superficies do quarto terapeutico na medida da taxa de exposicao de pacientes de radioiodoterapia

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Rafael Ferreira

    2015-07-01

    The contamination of radiotherapy room surfaces is significant and the measures of patient exposure rate are held on the fourth dependencies, relevant questions are raised: the background radiation of the room stay high due to surface contamination, may interfere with the rate of patient exposure at the time of its release? The monitoring site is important to determine whether the patient will be released? The value of the deal activity and the clinical condition of the patient may increase the contamination, influencing the monitoring results? This paper aims to conduct a quantitative analysis of surface contamination of the contribution of therapeutic room at the time is monitored exposure rate from inpatient. Measurements were made regarding the hospitalization of 32 patients with different doses administered activity, age and of both genders. The measurements were performed in the therapeutic rooms at the hospital Brotherhood Santa Casa de Misericordia de Sao Paulo. Exposure rate measurements were performed at the center of the room at 1 meter of the patient on the day of its release. After his release and prior to decontamination, measurements were performed at predetermined landmarks within the therapeutic room. The results revealed that on average background radiation, high due to surface contamination contributes only 2% of the patient dose rate. It can be considered that even with influence of contamination of surfaces, this is insignificant to determine if the patient may or may not be released. This study suggests that the site in which monitoring occurs exposure rate of the patient should not be decisive for liberation thereof. (author)

  10. Are radiosensitivity data derived from natural field conditions consistent with data from controlled exposures? A case study of Chernobyl wildlife chronically exposed to low dose rates

    International Nuclear Information System (INIS)

    Garnier-Laplace, J.; Geras’kin, S.; Della-Vedova, C.; Beaugelin-Seiller, K.; Hinton, T.G.; Real, A.; Oudalova, A.

    2013-01-01

    The discrepancy between laboratory or controlled conditions ecotoxicity tests and field data on wildlife chronically exposed to ionising radiation is presented for the first time. We reviewed the available chronic radiotoxicity data acquired in contaminated fields and used a statistical methodology to support the comparison with knowledge on inter-species variation of sensitivity to controlled external γ irradiation. We focus on the Chernobyl Exclusion Zone and effects data on terrestrial wildlife reported in the literature corresponding to chronic dose rate exposure situations (from background∼100 nGy/h up to ∼10 mGy/h). When needed, we reconstructed the dose rate to organisms and obtained consistent unbiased data sets necessary to establish the dose rate–effect relationship for a number of different species and endpoints. Then, we compared the range of variation of radiosensitivity of species from the Chernobyl-Exclusion Zone with the statistical distribution established for terrestrial species chronically exposed to purely gamma external irradiation (or chronic Species radioSensitivity Distribution – SSD). We found that the best estimate of the median value (HDR 50 ) of the distribution established for field conditions at Chernobyl (about 100 μGy/h) was eight times lower than the one from controlled experiments (about 850 μGy/h), suggesting that organisms in their natural environmental were more sensitive to radiation. This first comparison highlights the lack of mechanistic understanding and the potential confusion coming from sampling strategies in the field. To confirm the apparent higher sensitive of wildlife in the Chernobyl Exclusion Zone, we call for more a robust strategy in field, with adequate design to deal with confounding factors. -- Highlights: ► Discrepancy between controlled tests and Chernobyl effects data on wildlife was examined. ► We proposed a method to correct the dosimetry used for Chernobyl wildlife. ► Wildlife from the

  11. Maximum entropy principal for transportation

    International Nuclear Information System (INIS)

    Bilich, F.; Da Silva, R.

    2008-01-01

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

  12. Exposure of ELF-EMF and RF-EMF Increase the Rate of Glucose Transport and TCA Cycle in Budding Yeast.

    Science.gov (United States)

    Lin, Kang-Wei; Yang, Chuan-Jun; Lian, Hui-Yong; Cai, Peng

    2016-01-01

    In this study, we investigated the transcriptional response to 50 Hz extremely low frequency electromagnetic field (ELF-EMF) and 2.0 GHz radio frequency electromagnetic field (RF-EMF) exposure by Illumina sequencing technology using budding yeast as the model organism. The transcription levels of 28 genes were upregulated and those of four genes were downregulated under ELF-EMF exposure, while the transcription levels of 29 genes were upregulated and those of 24 genes were downregulated under RF-EMF exposure. After validation by reverse transcription quantitative polymerase chain reaction (RT-qPCR), a concordant direction of change both in differential gene expression (DGE) and RT-qPCR was demonstrated for nine genes under ELF-EMF exposure and for 10 genes under RF-EMF exposure. The RT-qPCR results revealed that ELF-EMF and RF-EMF exposure can upregulate the expression of genes involved in glucose transportation and the tricarboxylic acid (TCA) cycle, but not the glycolysis pathway. Energy metabolism is closely related with the cell response to environmental stress including EMF exposure. Our findings may throw light on the mechanism underlying the biological effects of EMF.

  13. Controlled exposure to particulate matter from urban street air is associated with decreased vasodilation and heart rate variability in overweight and older adults

    DEFF Research Database (Denmark)

    Hemmingsen, Jette Gjerke; Rissler, Jenny; Lykkesfeldt, Jens

    2015-01-01

    , age 55 to 83 years, body mass index > 25 kg/m(2)) were included in a cross-over study with 5 hours of exposure to particle- or sham-filtered air from a busy street using an exposure-chamber. The sham- versus particle-filtered air had average particle number concentrations of ~23.000 versus ~1800/cm(3...... counts). RESULTS: Nitroglycerin-induced vasodilation was reduced by 12% [95% confidence interval: -22%; -1.0%] following PM exposure, whereas hyperemia-induced vasodilation was reduced by 5% [95% confidence interval: -11.6%; 1.6%]. Moreover, HRV measurements showed that the high and low frequency domains...

  14. Last Glacial Maximum Salinity Reconstruction

    Science.gov (United States)

    Homola, K.; Spivack, A. J.

    2016-12-01

    It has been previously demonstrated that salinity can be reconstructed from sediment porewater. The goal of our study is to reconstruct high precision salinity during the Last Glacial Maximum (LGM). Salinity is usually determined at high precision via conductivity, which requires a larger volume of water than can be extracted from a sediment core, or via chloride titration, which yields lower than ideal precision. It has been demonstrated for water column samples that high precision density measurements can be used to determine salinity at the precision of a conductivity measurement using the equation of state of seawater. However, water column seawater has a relatively constant composition, in contrast to porewater, where variations from standard seawater composition occur. These deviations, which affect the equation of state, must be corrected for through precise measurements of each ion's concentration and knowledge of apparent partial molar density in seawater. We have developed a density-based method for determining porewater salinity that requires only 5 mL of sample, achieving density precisions of 10-6 g/mL. We have applied this method to porewater samples extracted from long cores collected along a N-S transect across the western North Atlantic (R/V Knorr cruise KN223). Density was determined to a precision of 2.3x10-6 g/mL, which translates to salinity uncertainty of 0.002 gms/kg if the effect of differences in composition is well constrained. Concentrations of anions (Cl-, and SO4-2) and cations (Na+, Mg+, Ca+2, and K+) were measured. To correct salinities at the precision required to unravel LGM Meridional Overturning Circulation, our ion precisions must be better than 0.1% for SO4-/Cl- and Mg+/Na+, and 0.4% for Ca+/Na+, and K+/Na+. Alkalinity, pH and Dissolved Inorganic Carbon of the porewater were determined to precisions better than 4% when ratioed to Cl-, and used to calculate HCO3-, and CO3-2. Apparent partial molar densities in seawater were

  15. Maximum Parsimony on Phylogenetic networks

    Science.gov (United States)

    2012-01-01

    Background Phylogenetic networks are generalizations of phylogenetic trees, that are used to model evolutionary events in various contexts. Several different methods and criteria have been introduced for reconstructing phylogenetic trees. Maximum Parsimony is a character-based approach that infers a phylogenetic tree by minimizing the total number of evolutionary steps required to explain a given set of data assigned on the leaves. Exact solutions for optimizing parsimony scores on phylogenetic trees have been introduced in the past. Results In this paper, we define the parsimony score on networks as the sum of the substitution costs along all the edges of the network; and show that certain well-known algorithms that calculate the optimum parsimony score on trees, such as Sankoff and Fitch algorithms extend naturally for networks, barring conflicting assignments at the reticulate vertices. We provide heuristics for finding the optimum parsimony scores on networks. Our algorithms can be applied for any cost matrix that may contain unequal substitution costs of transforming between different characters along different edges of the network. We analyzed this for experimental data on 10 leaves or fewer with at most 2 reticulations and found that for almost all networks, the bounds returned by the heuristics matched with the exhaustively determined optimum parsimony scores. Conclusion The parsimony score we define here does not directly reflect the cost of the best tree in the network that displays the evolution of the character. However, when searching for the most parsimonious network that describes a collection of characters, it becomes necessary to add additional cost considerations to prefer simpler structures, such as trees over networks. The parsimony score on a network that we describe here takes into account the substitution costs along the additional edges incident on each reticulate vertex, in addition to the substitution costs along the other edges which are

  16. Larval exposure to field-realistic concentrations of clothianidin has no effect on development rate, over-winter survival or adult metabolic rate in a solitary bee, Osmia bicornis.

    Science.gov (United States)

    Nicholls, Elizabeth; Fowler, Robert; Niven, Jeremy E; Gilbert, James D; Goulson, Dave

    2017-01-01

    There is widespread concern regarding the effects of agro-chemical exposure on bee health, of which neonicotinoids, systemic insecticides detected in the pollen and nectar of both crops and wildflowers, have been the most strongly debated. The majority of studies examining the effect of neonicotinoids on bees have focussed on social species, namely honey bees and bumble bees. However, most bee species are solitary, their life histories differing considerably from these social species, and thus it is possible that their susceptibility to pesticides may be quite different. Studies that have included solitary bees have produced mixed results regarding the impact of neonicotinoid exposure on survival and reproductive success. While the majority of studies have focused on the effects of adult exposure, bees are also likely to be exposed as larvae via the consumption of contaminated pollen. Here we examined the effect of exposure of Osmia bicornis larvae to a range of field-realistic concentrations (0-10 ppb) of the neonicotinoid clothianidin, observing no effect on larval development time, overwintering survival or adult weight. Flow-through respirometry was used to test for latent effects of larval exposure on adult physiological function. We observed differences between male and female bees in the propensity to engage in discontinuous gas exchange; however, no effect of larval clothianidin exposure was observed. Our results suggest that previously reported adverse effects of neonicotinoids on O. bicornis are most likely mediated by impacts on adults.