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Sample records for geiger muller counting

  1. Geiger-Muller (GM) counters. Associated circuits and counting techniques; Les compteurs de Geiger-Muller (GM). Les circuits associes et techniques de comptage

    Energy Technology Data Exchange (ETDEWEB)

    Benoit, A.; Picard, E. [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay (France)

    1954-07-01

    This article presents the Geiger-Muller counters which present the great benefit of being simple and steady in comparison with other known sensors. The authors propose an overview of problems related to the use of Geiger-Muller counters (GM counters). They first describe their operation (discharge initiation, discharge propagation, collection of positive ions and current in the counter). They discuss their limitations which are related to the migration delay of primary electrons and positive ions. They describe the operation circuit for counters with organic vapour, and for counters associated with counters using halogens. They address the main properties of GM counters, and the different factors to be taken into account when using them to count radioactive sources. The main types of GM counters are then described (they are used to measure different types of radiation). Measurement techniques are discussed for beta radiation (relationship between the number of disintegrations and the noticed counting rate, case of backscattering, absorption and diffusion in the counter window and in the air, influence of absorption and backscattering in the source), for alpha radiation, and for gamma radiation.

  2. Beta, gamma contamination analysis of thermo luminescence dosimeter cassettes using Geiger Muller counting set up and gamma spectrometry techniques

    International Nuclear Information System (INIS)

    Prasad, S.K.; Sudheer, T.S.; Sahoo, L.; Vinayagam, Bhakti; Kamble, Mahesh; Khuspe, R.R.; Anilkumar, Rekha; Verma, K.K.

    2009-01-01

    Β-γ contamination cheek up of TLD cassettes were carried out and the isotopes found were 137 Cs, 106 Ru, 60 Co, 64 Cu, 144 Ce and 95 Nb with activity per square cm varying from 0.05-4.70 Bq/cm 2 with median value 1.3. The assessed dose in TLD was in the range of 2.10 mSv to 22.05 mSv for beta, 0.05 mSv to 5.25 mSv for gamma. The beta doses have median value of 6.19 mSv. This contamination may be due to active water contamination on TLD's of personnel working for irradiated fuel handling or work in fuel rod (under water) storage area. This gives a method to estimate skin exposure of personnel due to skin contamination during work. Chances of getting TLD's contaminated due to various reasons were studied. Contamination was found maximum inside the cassette box having area 16 cm 2 . In case of plastic pouch of TLD disc contamination was detected in three cases. Contamination level on TLD cassettes using GM counter was found in the range of 0.30-3.6 Bq/cm 2 for cassettes. By opening the window of the surveymeter contamination and field of these cassettes in closed condition were found to increase by 20% due to the measurement of beta dose. With the same condition contamination of TLD cassette in open condition was found five times more. This is due to the a-contamination which is five times more than a contamination, The most prominent isotope 137 Cs in common chemical forms are soluble in water and if inhaled or ingested are rapidly and completely absorbed in the lungs and across the gastrointestinal tract. Thus a skin contamination of most prominent isotope 137 Cs can lead to intake in addition to skin dose. Fading studies of contamination of TLD cassettes were carried out. It was found negligible after counting with GM counting set up after a period of 3 months. But one of the TLD cassettes was showing an 80% reduction of contamination after 3 months with GM counting set up, the contaminants being 141 Ce, 103 Ru and 95 Nb. The gamma peaks in the external exposure

  3. Geiger-Muller with a mica window halogen quenched counters aspects

    International Nuclear Information System (INIS)

    Gorski, M.S.; Bruzinga, W.A.

    1990-09-01

    We present the development of a model of a Geiger-Muller with likeness the model ZP 1410 Phillips. The prototype has a cylindrical shape with 37mm of effective length and a mica window of 1,5 to 2,0mg/cm sup(2) thickness with a useful diam of 19,8mm. For the window preparation and special cutting technique was developed Basically two types of quenching agents, bromine and chlorine were studied. Due to the high corrosive nature of these gases, we work with treatment of surface of the cathode through electropolishment, chemical passiveness, hard chrome and nickel coating. Out main objective was to get a Geiger-Muller detector with an operational plateau over 200V, working voltage above 600V and a sensivity of 320 counts/sec at 10 sup(-1) m Gy/h. (author)

  4. Geiger Muller (GM) detector as online monitor: an experimental study

    International Nuclear Information System (INIS)

    Jayan, M.P.; Pawar, V.J.; Krishnakumar, P.; Sureshkumar, M.

    2014-01-01

    Monitoring the inadvertent release of radioactivity into otherwise inactive liquid streams is a common requirement in nuclear industry. In addition to conventional off-line sampling and measurement methods, nuclear facilities usually uses online methods to get real-time detection of activity contents in process cooling water lines and steam condensate lines. Due to its simplicity, ruggedness and cost effectiveness, Geiger Muller counter is obviously the first choice for online application. Though GM based monitors for such online application were in industrial use for a long time, practical data on the response of the detector with respect low level activities in the effluents is scarce in literature. This work was carried out to fill this information gap. The data generated in these experiments may be useful in giving a realistic interpretation of the response of the existing monitors and setting up their alarm limits

  5. Statistical analysis of natural radiation levels inside the UNICAMP campus through the use of Geiger-Muller counter; Analise estatistica dos niveis de radiacao natural dentro da UNICAMP atraves do uso de contador Geiger-Muller

    Energy Technology Data Exchange (ETDEWEB)

    Fontolan, Juliana A.; Biral, Antonio Renato P., E-mail: fontolanjuliana@gmail.com.br, E-mail: biral@ceb.unicamp.br [Hospital das Clinicas (CEB/UNICAMP), Campinas, SP (Brazil). Centro de Engenharia Biomedica

    2013-07-01

    It is known that the distribution at time intervals of random and unrelated events leads to the Poisson distribution . This work aims to study the distribution in time intervals of events resulting from radioactive decay of atoms present in the UNICAMP where activities involving the use of ionizing radiation are performed environments . The proposal is that the distribution surveys at intervals of these events in different locations of the university are carried out through the use of a Geiger-Mueller tube . In a next step , the evaluation of distributions obtained by using non- parametric statistics (Chi- square and Kolmogorov Smirnoff) will be taken . For analyzes involving correlations we intend to use the ANOVA (Analysis of Variance) statistical tool . Measured in six different places within the Campinas , with the use of Geiger- Muller its count mode and a time window of 20 seconds was performed . Through statistical tools chi- square and Kolmogorov Smirnoff tests, using the EXCEL program , it was observed that the distributions actually refer to a Poisson distribution. Finally, the next step is to perform analyzes involving correlations using the statistical tool ANOVA.

  6. Statistical analysis of natural radiation levels inside the UNICAMP campus through the use of Geiger-Muller counter

    International Nuclear Information System (INIS)

    Fontolan, Juliana A.; Biral, Antonio Renato P.

    2013-01-01

    It is known that the distribution at time intervals of random and unrelated events leads to the Poisson distribution . This work aims to study the distribution in time intervals of events resulting from radioactive decay of atoms present in the UNICAMP where activities involving the use of ionizing radiation are performed environments . The proposal is that the distribution surveys at intervals of these events in different locations of the university are carried out through the use of a Geiger-Mueller tube . In a next step , the evaluation of distributions obtained by using non- parametric statistics (Chi- square and Kolmogorov Smirnoff) will be taken . For analyzes involving correlations we intend to use the ANOVA (Analysis of Variance) statistical tool . Measured in six different places within the Campinas , with the use of Geiger- Muller its count mode and a time window of 20 seconds was performed . Through statistical tools chi- square and Kolmogorov Smirnoff tests, using the EXCEL program , it was observed that the distributions actually refer to a Poisson distribution. Finally, the next step is to perform analyzes involving correlations using the statistical tool ANOVA

  7. Performances of Dose Measurement of Commercial Electronic Dosimeters using Geiger Muller Tube and PIN Diode

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hyunjun; Kim, Chankyu; Kim, Yewon; Kim, Giyoon; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    There are two categories in personal dosimeters, one is passive type dosimeter such as TLD (thermoluminescence dosimeter) and the other is active type dosimeter such as electronic dosimeter can show radiation dose immediately while TLD needs long time to readout its data by heating process. For improving the reliability of measuring dose for any energy of radiations, electronic dosimeter uses energy filter by metal packaging its detector using aluminum or copper, but measured dose of electronic dosimeter with energy filter cannot be completely compensated in wide radiation energy region. So, in this paper, we confirmed the accuracy of dose measurement of two types of commercial EPDs using Geiger Muller tube and PIN diode with CsI(Tl) scintillator in three different energy of radiation field. The experiment results for Cs-137 was almost similar with calculation value in the results of both electronic dosimeters, but, the other experiment values with Na-22 and Co-60 had higher error comparing with Cs-137. These results were caused by optimization of their energy filters. The optimization was depending on its thickness of energy filter. So, the electronic dosimeters have to optimizing the energy filter for increasing the accuracy of dose measurement or the electronic dosimeter using PIN diode with CsI(Tl) scintillator uses the multi-channel discriminator for using its energy information.

  8. As the crack in the Geiger counter came. Historical scientific analysis and didactic aspects of the Geiger-Mueller counting tube

    International Nuclear Information System (INIS)

    Korff, Sebastian

    2014-01-01

    This thesis studies the creation and establishment history of this instrument called first electron counting tube in the years 1928 and 1929. It deals thereby with the last two years of the common work of Hans Geiger and Walter Mueller, from which the measuring instrument later renamed to Geiger-Mueller counting tube. The results of this scientific case study are didactically worked out and made usable for the teaching of physics in the school.

  9. As the crack in the Geiger counter came. Historical scientific analysis and didactic aspects of the Geiger-Mueller counting tube; Wie das Knacken in den Geigerzaehler kam. Wissenschaftshistorische Analyse und fachdidaktische Aspekte des Geiger-Mueller Zaehlrohrs

    Energy Technology Data Exchange (ETDEWEB)

    Korff, Sebastian

    2014-11-10

    This thesis studies the creation and establishment history of this instrument called first electron counting tube in the years 1928 and 1929. It deals thereby with the last two years of the common work of Hans Geiger and Walter Mueller, from which the measuring instrument later renamed to Geiger-Mueller counting tube. The results of this scientific case study are didactically worked out and made usable for the teaching of physics in the school.

  10. The performance of photon counting imaging with a Geiger mode silicon avalanche photodiode

    International Nuclear Information System (INIS)

    Qu, Hui-Ming; Zhang, Yi-Fan; Ji, Zhong-Jie; Chen, Qian

    2013-01-01

    In principle, photon counting imaging can detect a photon. With the development of low-level-light image intensifier techniques and low-level-light detection devices, photon counting imaging can now detect photon images under extremely low illumination. Based on a Geiger mode silicon avalanche photodiode single photon counter, an experimental system for photon counting imaging was built through two-dimensional scanning of a SPAD (single photon avalanche diode) detector. The feasibility of the imaging platform was validated experimentally. Two images with different characteristics, namely, the USAF 1951 resolution test panel and the image of Lena, were chosen to evaluate the imaging performance of the experimental system. The results were compared and analysed. The imaging properties under various illumination and scanning steps were studied. The lowest illumination limit of the SPAD photon counting imaging was determined. (letter)

  11. Reduction of the duration of the natural dead time of a 4 {pi} gas ionization counter operating in geiger-muller; Reduction de la duree de l'etat d'insensibilite naturelle d'un compteur a ionisation gazeuse de geometrie 4 {pi} travaillant en regime de Geiger-Muller

    Energy Technology Data Exchange (ETDEWEB)

    Becker, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, Departement d' Electronique Generale, Laboratoire de Mesure des Radioelements

    1967-07-01

    It Is only possible to benefit from the 100 per cent efficiency of a 4 {pi} gas-ionisation detector operating in the Geiger-Muller regime (an efficiency which always appears difficult to attain in other detectors) if, one is able: - on the one hand to reduce considerably - on the other hand to fix very precisely the length at the real dead time of the system operating in the above conditions. Taking into account both the phenomena characteristic of the discharge in the regime under consideration, phenomena whose properties are described, and the geometrical conditions depending on the operation over a solid angle of 4 {pi}, it is shown that with an exterior electronic system for cutting off the discharge for example in 30 nanoseconds, absolute 4 {pi} G.M. measurements would become competitive with those now carried out almost in proportional conditions. Measurement results on sources of 5 x 10{sup 3} emissions per second maximum obtained by the use of a system for which the interval between the passage of a particle and the moment when the device has been made insensitive is still 60 nanoseconds have made it possible to confirm these statements. (author) [French] De l'efficacite de 100 pour cent du detecteur a ionisation gazeuse travaillant en regime de Geiger-Muller en geometrie 4 {pi} (efficacite toujours difficile a atteindre par d'autres detecteurs semble-t-il) on ne peut cependant beneficier que si l'on est capable: - d'une part, de reduire considerablement - d'autre part, de fixer de maniere tres precise la duree d'insensibilite reelle du systeme travaillant dans les conditions ci-dessus. Tenant compte des phenomenes propres a la decharge, dans le regime en question, phenomenes dont on rappeUto quelques caracteristiques, et des conditions geometriques propres a une detection dans un angle solide de 4 {pi} on montre qu'avec un systeme electronique de coupure externe de la decharge qui arreterait cette derniere en 30 nanosecondes par exemple, des mesures

  12. Reduction of the duration of the natural dead time of a 4 {pi} gas ionization counter operating in geiger-muller; Reduction de la duree de l'etat d'insensibilite naturelle d'un compteur a ionisation gazeuse de geometrie 4 {pi} travaillant en regime de Geiger-Muller

    Energy Technology Data Exchange (ETDEWEB)

    Becker, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, Departement d' Electronique Generale, Laboratoire de Mesure des Radioelements

    1967-07-01

    It Is only possible to benefit from the 100 per cent efficiency of a 4 {pi} gas-ionisation detector operating in the Geiger-Muller regime (an efficiency which always appears difficult to attain in other detectors) if, one is able: - on the one hand to reduce considerably - on the other hand to fix very precisely the length at the real dead time of the system operating in the above conditions. Taking into account both the phenomena characteristic of the discharge in the regime under consideration, phenomena whose properties are described, and the geometrical conditions depending on the operation over a solid angle of 4 {pi}, it is shown that with an exterior electronic system for cutting off the discharge for example in 30 nanoseconds, absolute 4 {pi} G.M. measurements would become competitive with those now carried out almost in proportional conditions. Measurement results on sources of 5 x 10{sup 3} emissions per second maximum obtained by the use of a system for which the interval between the passage of a particle and the moment when the device has been made insensitive is still 60 nanoseconds have made it possible to confirm these statements. (author) [French] De l'efficacite de 100 pour cent du detecteur a ionisation gazeuse travaillant en regime de Geiger-Muller en geometrie 4 {pi} (efficacite toujours difficile a atteindre par d'autres detecteurs semble-t-il) on ne peut cependant beneficier que si l'on est capable: - d'une part, de reduire considerablement - d'autre part, de fixer de maniere tres precise la duree d'insensibilite reelle du systeme travaillant dans les conditions ci-dessus. Tenant compte des phenomenes propres a la decharge, dans le regime en question, phenomenes dont on rappeUto quelques caracteristiques, et des conditions geometriques propres a une detection dans un angle solide de 4 {pi} on montre qu'avec un systeme electronique de coupure externe de la decharge qui arreterait cette derniere en 30

  13. Geiger-Mueller haloid counter dead time dependence on counting rate

    International Nuclear Information System (INIS)

    Onishchenko, A.M.; Tsvetkov, A.A.

    1980-01-01

    The experimental dependences of the dead time of Geiger counters (SBM-19, SBM-20, SBM-21 and SGM-19) on the loading, are presented. The method of two sources has been used to determine the dead time counters of increased stability. The counters are switched on according to the usually used circuit of discrete counting with loading resistance of 50 MOhm and the separating capacity of 10 pF. Voltage pulses are given to the counting device with the time of resolution of 100 ns, discrimenation threshold 3 V, input resistance 3.6 Ω and the input capacity-15 pF. The time constant of the counter RC-circuit is 50 μs

  14. Potassium analysis by beta counting using a Geiger-Mueller system

    International Nuclear Information System (INIS)

    Espana, E.; Beneitez, P.; Calderon, T.

    1993-01-01

    A technique for quantitative analysis of different soils, ceramics, feldspars and natural halide samples is presented, based on the measurement of β-activities using a Geiger-Mueller system. The system was calibrated with KCl, KC 8 H 5 O 4 , KNO 3 and K 2 SO 4 standards and a potassium content of 1% yields a net β-count rate (background subtracted) of about 55 cph. Precision values of less than ±0.4% K can be achieved in counting times of about 4 hours. The results agree with those obtained by means of other more common analytical methods such as flame photometry, atomic absorption and γ-spectrometry. In comparison with these methods, this approach is direct, precise and non-destructive, because the samples do not require prior treatment. (author) 16 refs.; 2 figs.; 6 tabs

  15. Lifetime characteristics of Gaiger-Muller counters

    Directory of Open Access Journals (Sweden)

    Kartalović Nenad M.

    2016-01-01

    Full Text Available This paper discusses the process of functional aging of Geiger-Muller counters. Two types of Geiger-Muller counter chambers were characterized in an experiment using a combined constant voltage. Chamber A had a coaxial geometry and chamber B had a plan-parallel geometry. The experimental results indicate that the aging process was faster in the case of chambers with a coaxial geometry. The results are explained based on the process of electrical discharges in gasses.

  16. Readout electronics for low dark count pixel detectors based on Geiger mode avalanche photodiodes fabricated in conventional CMOS technologies for future linear colliders

    International Nuclear Information System (INIS)

    Vilella, E.; Arbat, A.; Comerma, A.; Trenado, J.; Alonso, O.; Gascon, D.; Vila, A.; Garrido, L.; Dieguez, A.

    2011-01-01

    High sensitivity and excellent timing accuracy of the Geiger mode avalanche photodiodes make them ideal sensors as pixel detectors for particle tracking in high energy physics experiments to be performed in future linear colliders. Nevertheless, it is well known that these sensors suffer from dark counts and afterpulsing noise, which induce false hits (indistinguishable from event detection) as well as an increase in the necessary area of the readout system. In this work, we present a comparison between APDs fabricated in a high voltage 0.35 μm and a high integration 0.13 μm commercially available CMOS technologies that has been performed to determine which of them best fits the particle collider requirements. In addition, a readout circuit that allows low noise operation is introduced. Experimental characterization of the proposed pixel is also presented in this work.

  17. Characteristics and fabrication of Geiger-Mueller counters with thin walls made of treated magnesium - Note about the use of araldite; Caracteristiques et fabrication des compteurs Geiger-Muller a paroi mince en magnesium traite - Note sur l'utilisation de l'araldite

    Energy Technology Data Exchange (ETDEWEB)

    Charbonnel, A

    1949-03-01

    This report describes, first, the advantage of magnesium for the manufacturing of Geiger-Mueller counters: suitable for machining and polishing, but strong reactivity with the counter atmosphere in the case of magnesium-rich alloys. Thus, the inside wall of the counter (cylinder of 20 mm diameter and 6 cm length) requires a non-reactive protective coating with excellent sealing properties. The synthetic resin 'araldite' fulfills all these conditions. The second part of the report describes the different steps of the fabrication of magnesium wall counters: lathe work, machining down and chemical polishing of hulls, assembly, tight sealing, pumping, filling-up and control tests. The average service life of these counters is of about 4 months. A note about the use and properties (hardening, mechanical properties, resistance..) of araldite is given in appendix. (J.S.)

  18. Characteristics and fabrication of Geiger-Mueller counters with thin walls made of treated magnesium - Note about the use of araldite; Caracteristiques et fabrication des compteurs Geiger-Muller a paroi mince en magnesium traite - Note sur l'utilisation de l'araldite

    Energy Technology Data Exchange (ETDEWEB)

    Charbonnel, A

    1949-03-01

    This report describes, first, the advantage of magnesium for the manufacturing of Geiger-Mueller counters: suitable for machining and polishing, but strong reactivity with the counter atmosphere in the case of magnesium-rich alloys. Thus, the inside wall of the counter (cylinder of 20 mm diameter and 6 cm length) requires a non-reactive protective coating with excellent sealing properties. The synthetic resin 'araldite' fulfills all these conditions. The second part of the report describes the different steps of the fabrication of magnesium wall counters: lathe work, machining down and chemical polishing of hulls, assembly, tight sealing, pumping, filling-up and control tests. The average service life of these counters is of about 4 months. A note about the use and properties (hardening, mechanical properties, resistance..) of araldite is given in appendix. (J.S.)

  19. Construction techniques and operation principles of Geiger-Mueller counters using external cathode (Mazetype)

    International Nuclear Information System (INIS)

    Sevegnani, F.X.

    1988-01-01

    The construction techniques for external cathode (Maze) and internal cathode Geiger-Muller counters are described, showing the operation principles and the used material nature. More than 200 counter types were evaluated analysing their characteristics. The influence of several types of guard-rings was studied, for optimizing counter operation conditions. Plateaus of the order of 700 V with slope of 0,3%/100 V for the net counting rate, and 1400 V with a slope of 0,8/100 V for total counts using total pressure of 10 cmHg, were obtained. A counter for β detection, using blown glass window in one of the edges of the cylinder was constructed. Counters of long life using materials such as, mica, adhesive glues, etc., were obtained. The results shown that the best counter operation occurs when it is empty in a vacuum of 10 -5 mmHg. (M.C.K.) [pt

  20. Determination of some fundamental characteristics of Geiger-Mueller counters. Applications to the study of delayed particles from cosmic-ray shower; Sur la determination de quelques caracteristiques fondamentales de compteurs de geiger-muller applications a l'etude des particules retardees des gerbes atmospheriques du rayonnement cosmique

    Energy Technology Data Exchange (ETDEWEB)

    Picard, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1954-06-15

    After some historic recalls, the different phases of discharge of a Geiger-Mueller counter is studied. It measures, by oscillograph method, the time between the flow of a particle through a determined area of the counter and the response of the associated amplifier. This time length is composed by the latency period and the delay itself which depends on the amplifier sensitivity. The selection of particles which generate a discharge in the studied counter is obtained with a two coincidence counters telescope in which the aperture is limited by four counters in anticoincidence with the first two counters. The measures have been done with different distance values and an overvoltage V{sub s} which was applied to the counter. The dead time of a GM counter is also measured with a delayed coincidences method. The counter pulses which supply the coincidence circuit are delivered directly or with a known and variable delay. This method allows also to study the spurious pulses which are due to the positive ions impact on the counter cathode. Results for counters working in different conditions are given. It describes the system to limit the discharge which induces the increase of the life working of a counter, the decrease of its dead time and the reduction of the number of spurious pulses. In a second part, it describes the system to study the time correlation between different particles of the cosmic ray. An experiment concerning the presence of delayed particles in cosmic showers has permitted to specify the superior limit of this phenomena which is directly connected to the presence of heavy nuclear particles in the cosmic shower. (M.P.)

  1. Advanced digital counting rate meter for gamma ray logging

    International Nuclear Information System (INIS)

    Kannan, S.; Meenakshi Sundari, A.; Rai, A.K.

    2013-01-01

    A compact, hand held controller based Advanced Digital Count Rate Meter (ADCRM) as a replacement of bulky Count Rate (analog) Meters (SBL-2A) was designed, developed and fabricated to carry out Gamma-Ray borehole logging with Geiger Muller (GM) tubes and Scintillation (SC) detectors. In the hardware the functionality of analog meter simulation, digital counting of gamma events and auto reference adjustment to use different length of armour cable winches were implemented. The in-built software evaluates grade in ppm and at the end of logging, the reports are prepared automatically. ADCRM was developed in-house to assist the uranium mineral exploration in AMD. (author)

  2. Didactic counter unit with Geiger-Muller tubes

    International Nuclear Information System (INIS)

    Campos, A.

    1981-01-01

    At this paper a prototype of these instruments is search for a didactic application. A block diagram to instrument, well as an operation process of it, is developed. A description of each one blocks, mentioning the characteristics, advantages and, to compare some possible solutions, is also presented. (author)

  3. Optical Communications With A Geiger Mode APD Array

    Science.gov (United States)

    2016-02-09

    practical performance of a Geiger mode avalanche photodiode ( GM -APD, or Geiger mode APD) array for use in optical com- munications systems. I designed and...signal quality in the first half of the frame. These shorter reset times also did not offer any advantage in the maximum number of counts able to be...pattern was advantageous for the modifications being made in post-processing on the benchmark data. In particular, this allowed post-processing results

  4. Geiger counters of gamma rays with a bismuth cathode

    International Nuclear Information System (INIS)

    Meunier, R.; Legrand, J.P.

    1953-01-01

    Geiger Muller counters present a lake of efficiency of some per cent, for the γ radiations. In the region 0,3 - 1 MeV, a substantial growth of their output can be obtained by a special construction of their cathode. In accordance with previous works, we constructed some counter of formed cathode by a pleated copper wire fencing covered of Bi by electrolysis. The successive modifications brought to a cylindrical conventional cathode in sheet metal of copper, that succeeds to this type of cathode, drive to an improvement of the output. (M.B.) [fr

  5. In Memoriam Dr. J. Muller

    NARCIS (Netherlands)

    Kalkman, C.

    1984-01-01

    At the age of 61, Jan Muller died on 5 October 1983, after a very short illness which only some weeks earlier had been detected. His rapid decline but also his courage during the last few weeks, have made a deep impression on all who have witnessed them. Jan Muller was born on 15 October 1921 at

  6. Geiger counters of gamma rays with a bismuth cathode; Compteurs de geiger a rayons gamma a cathode de bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Meunier, R; Legrand, J P [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

    1953-07-01

    Geiger Muller counters present a lake of efficiency of some per cent, for the {gamma} radiations. In the region 0,3 - 1 MeV, a substantial growth of their output can be obtained by a special construction of their cathode. In accordance with previous works, we constructed some counter of formed cathode by a pleated copper wire fencing covered of Bi by electrolysis. The successive modifications brought to a cylindrical conventional cathode in sheet metal of copper, that succeeds to this type of cathode, drive to an improvement of the output. (M.B.) [French] Les compteurs de Geiger Muller presentent une efficacite assez faible de l'ordre de quelques pour cent, pour les rayonnements {gamma}. Dans la region 0,3 - 1 MeV, un accroissement substantiel de leur rendement peut etre obtenu par une construction speciale de leur cathode. Conformement a des travaux anterieurs, nous avons construit des compteurs a cathode formee par un grillage de cuivre plisse recouvert de Bi par electrolyse. Les modifications successives apportees a une cathode conventionnelle cylindrique en tole de cuivre, qui aboutissent a ce type de cathode, conduisent a une amelioration du rendement. (M.B.)

  7. Description of the manufacture of a Geiger-Muller counter with window; Descripcion de la fabricacion de un contador Geiger-Muller con ventana

    Energy Technology Data Exchange (ETDEWEB)

    Granados, C E

    1959-07-01

    Total details about the manufacture elements in counter fabrication and the way of obtention are described as well as total indications useful in the installation process and filling of the counter. The appropriate materials and precautions that might be adopted in order to obtain counters with uniform operation and good characteristics, are described. Counters are of brass, with thin mica or aluminium windows and operate at 1100 V approximately with a slope lower than 5 % 1100 V. (Author)

  8. Geiger mode avalanche photodiodes for microarray systems

    Science.gov (United States)

    Phelan, Don; Jackson, Carl; Redfern, R. Michael; Morrison, Alan P.; Mathewson, Alan

    2002-06-01

    New Geiger Mode Avalanche Photodiodes (GM-APD) have been designed and characterized specifically for use in microarray systems. Critical parameters such as excess reverse bias voltage, hold-off time and optimum operating temperature have been experimentally determined for these photon-counting devices. The photon detection probability, dark count rate and afterpulsing probability have been measured under different operating conditions. An active- quench circuit (AQC) is presented for operating these GM- APDs. This circuit is relatively simple, robust and has such benefits as reducing average power dissipation and afterpulsing. Arrays of these GM-APDs have already been designed and together with AQCs open up the possibility of having a solid-state microarray detector that enables parallel analysis on a single chip. Another advantage of these GM-APDs over current technology is their low voltage CMOS compatibility which could allow for the fabrication of an AQC on the same device. Small are detectors have already been employed in the time-resolved detection of fluorescence from labeled proteins. It is envisaged that operating these new GM-APDs with this active-quench circuit will have numerous applications for the detection of fluorescence in microarray systems.

  9. Applications Geiger-Muller detectors monitor the level of radioactivity in the human body

    International Nuclear Information System (INIS)

    Gunarwan Prayitno

    2008-01-01

    Nuclear technology is the technology high risk, because of an application and implementation have to support by human skill. The support facility has to complete and up to date, or modern. It means if the accident occurs in mistake have to do or delayed something, they can solved that problem. So the probability the risk of accident can be minimized. The specific problem is in the implementation nuclear technology on the human safety which is works in the radiation field or in the environment where they are working. The pointer that the problems have to design the tools monitor to monitoring the value radiation maximum was allowed. The tools monitor design is giving the information signal, if the radiation level maximum have over limit. Whereas the high and low level radiation can be just depend on the needed. (author)

  10. Description of the manufacture of a Geiger-Muller counter with window

    International Nuclear Information System (INIS)

    Granados, C. E.

    1959-01-01

    Total details about the manufacture elements in counter fabrication and the way of obtention are described as well as total indications useful in the installation process and filling of the counter. The appropriate materials and precautions that might be adopted in order to obtain counters with uniform operation and good characteristics, are described. Counters are of brass, with thin mica or aluminium windows and operate at 1100 V approximately with a slope lower than 5 % 1100 V. (Author)

  11. Playing Muller Games in a Hurry

    Directory of Open Access Journals (Sweden)

    John Fearnley

    2010-06-01

    Full Text Available This work studies the following question: can plays in a Muller game be stopped after a finite number of moves and a winner be declared. A criterion to do this is sound if Player 0 wins an infinite-duration Muller game if and only if she wins the finite-duration version. A sound criterion is presented that stops a play after at most 3^n moves, where n is the size of the arena. This improves the bound (n!+1^n obtained by McNaughton and the bound n!+1 derived from a reduction to parity games.

  12. Playing Muller Games in a Hurry

    OpenAIRE

    Fearnley, John; Zimmermann, Martin

    2010-01-01

    This work studies the following question: can plays in a Muller game be stopped after a finite number of moves and a winner be declared. A criterion to do this is sound if Player 0 wins an infinite-duration Muller game if and only if she wins the finite-duration version. A sound criterion is presented that stops a play after at most 3^n moves, where n is the size of the arena. This improves the bound (n!+1)^n obtained by McNaughton and the bound n!+1 derived from a reduction to parity games.

  13. ASIC Readout Circuit Architecture for Large Geiger Photodiode Arrays

    Science.gov (United States)

    Vasile, Stefan; Lipson, Jerold

    2012-01-01

    The objective of this work was to develop a new class of readout integrated circuit (ROIC) arrays to be operated with Geiger avalanche photodiode (GPD) arrays, by integrating multiple functions at the pixel level (smart-pixel or active pixel technology) in 250-nm CMOS (complementary metal oxide semiconductor) processes. In order to pack a maximum of functions within a minimum pixel size, the ROIC array is a full, custom application-specific integrated circuit (ASIC) design using a mixed-signal CMOS process with compact primitive layout cells. The ROIC array was processed to allow assembly in bump-bonding technology with photon-counting infrared detector arrays into 3-D imaging cameras (LADAR). The ROIC architecture was designed to work with either common- anode Si GPD arrays or common-cathode InGaAs GPD arrays. The current ROIC pixel design is hardwired prior to processing one of the two GPD array configurations, and it has the provision to allow soft reconfiguration to either array (to be implemented into the next ROIC array generation). The ROIC pixel architecture implements the Geiger avalanche quenching, bias, reset, and time to digital conversion (TDC) functions in full-digital design, and uses time domain over-sampling (vernier) to allow high temporal resolution at low clock rates, increased data yield, and improved utilization of the laser beam.

  14. Hermann Muller and Mutations in Drosophila

    Science.gov (United States)

    dropdown arrow Site Map A-Z Index Menu Synopsis Hermann Muller and Mutations in Drosophila Resources with University of Texas. In Austin his experiments on fruit flies (Drosophila) first showed that exposure to September to spend a year at the only Drosophila laboratory in Europe which was doing parallel work

  15. Application of a background-compensated Geiger-Mueller counter to a survey meter

    International Nuclear Information System (INIS)

    Mori, C.; Kumanomido, H.; Watanabe, T.

    1984-01-01

    A background-compensated Geiger-Mueller counter was used as a probe for a GM survey meter to obtain a net count rate of β-rays from a radioactive source in a quick survey. Although a background counting ratio between the two parts in the counter, front and rear, varied somewhat depending on the incident direction of background γ-rays, it was possible to compensate the background counts by subtracting a part of the rear counts, which were background counts, from the front counts, which contained β-ray counts and background counts. Undesirable small pulses generated during the recovering time after a full Geiger discharge were eliminated by an anticoincidence gating method. The survey meter with this counter and a differential ratemeter is useful for obtaining a net count rate of β-rays emitted from a surface radioactive-contamination or from a source being put near the window of the counter with nearly the same accuracy in half the measuring time as compared with conventional GM counters. (orig.)

  16. Cosmic rays with portable Geiger counters: from sea level to airplane cruise altitudes

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, Francesco; La Rocca, Paola; Riggi, Francesco [Department of Physics and Astronomy, University of Catania, Via S. Sofia 64, I-95123 Catania (Italy)], E-mail: Francesco.Riggi@ct.infn.it

    2009-07-15

    Cosmic ray count rates with a set of portable Geiger counters were measured at different altitudes on the way to a mountain top and aboard an aircraft, between sea level and cruise altitude. Basic measurements may constitute an educational activity even with high school teams. For the understanding of the results obtained, simulations of extensive air showers induced by high-energy primary protons in the atmosphere were also carried out, involving undergraduate and graduate teaching levels.

  17. Detection and counting systems

    International Nuclear Information System (INIS)

    Abreu, M.A.N. de

    1976-01-01

    Detection devices based on gaseous ionization are analysed, such as: electroscopes ionization chambers, proportional counters and Geiger-Mueller counters. Scintillation methods are also commented. A revision of the basic concepts in electronics is done and the main equipment for counting is detailed. In the study of gama spectrometry, scintillation and semiconductor detectors are analysed [pt

  18. Radiation intensity counting system

    International Nuclear Information System (INIS)

    Peterson, R.J.

    1982-01-01

    A method is described of excluding the natural dead time of the radiation detector (or eg Geiger-Mueller counter) in a ratemeter counting circuit, thus eliminating the need for dead time corrections. Using a pulse generator an artificial dead time is introduced which is longer than the natural dead time of the detector. (U.K.)

  19. An Inexpensive Coincidence Circuit for the Pasco Geiger Sensors

    CERN Document Server

    Fichera, F; Librizzi, F; Riggi, F

    2005-01-01

    A simple coincidence circuit was devised to carry out educational coincidence experiments involving the use of Geiger counters. The system was tested by commercially available Geiger sensors from PASCO, and is intended to be used in collaboration with high school students and teachers

  20. Construction techniques and working principles of external cathode Geiger-Mueller counters

    International Nuclear Information System (INIS)

    Sevegnani, Francisco Xavier

    1996-01-01

    In this paper, the construction technique and working principles of the external cathode Geiger-Mueller counter are described in detail. During the analysis of the behavior of these counters a new phenomena was observed, related to an increase int he background rate with the applied voltage. The experiments have also shown that the pulse amplitude of those counters decreases exponentially with the counting rate. The counters built with the techniques described in this paper has shown plateaus of about 1400 V with slope of 0,8%/100 V. (author)

  1. Rare beneficial mutations can halt Muller's ratchet

    Science.gov (United States)

    Balick, Daniel; Goyal, Sidhartha; Jerison, Elizabeth; Neher, Richard; Shraiman, Boris; Desai, Michael

    2012-02-01

    In viral, bacterial, and other asexual populations, the vast majority of non-neutral mutations are deleterious. This motivates the application of models without beneficial mutations. Here we show that the presence of surprisingly few compensatory mutations halts fitness decay in these models. Production of deleterious mutations is balanced by purifying selection, stabilizing the fitness distribution. However, stochastic vanishing of fitness classes can lead to slow fitness decay (i.e. Muller's ratchet). For weakly deleterious mutations, production overwhelms purification, rapidly decreasing population fitness. We show that when beneficial mutations are introduced, a stable steady state emerges in the form of a dynamic mutation-selection balance. We argue this state is generic for all mutation rates and population sizes, and is reached as an end state as genomes become saturated by either beneficial or deleterious mutations. Assuming all mutations have the same magnitude selective effect, we calculate the fraction of beneficial mutations necessary to maintain the dynamic balance. This may explain the unexpected maintenance of asexual genomes, as in mitochondria, in the presence of selection. This will affect in the statistics of genetic diversity in these populations.

  2. Radiation damage of multipixel Geiger-mode avalanche photodiodes irradiated with low-energy γ's and electrons

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Y.; Yun, Y. B. [Yonsei University, Seoul (Korea, Republic of); Ha, J. M. [Yonsei University, Seoul (Korea, Republic of); Electronics and Telecommunications Research Institute, Daejeon (Korea, Republic of); Lee, J. S.; Yoon, Y. S. [Electronics and Telecommunications Research Institute, Daejeon (Korea, Republic of); Eun, J. W. [Namseoul University, Cheonan (Korea, Republic of)

    2012-05-15

    A few types of multipipixel Geiger-mode avalanche photodiodes (also referred to as silicon photomultipliers SiPMs) are irradiated with 1 to 2.5 MeV γ's and electrons. We characterize radiation damage effects appearing in the reverse bias current, the dark current and count rate, the pixel gain, and the photon detection efficiency of the devices. An interesting observation on the dark current and count rate is made and linked to the specific damage caused by the irradiation.

  3. Multipixel geiger-mode photon detectors for ultra-weak light sources

    International Nuclear Information System (INIS)

    Campisi, A.; Cosentino, L.; Finocchiaro, P.; Pappalardo, A.; Musumeci, F.; Privitera, S.; Scordino, A.; Tudisco, S.; Fallica, G.; Sanfilippo, D.; Mazzillo, M.; Condorelli, G.; Piazza, A.; Valvo, G.; Lombardo, S.; Sciacca, E.; Bonanno, G.; Belluso, M.

    2007-01-01

    Arrays of Single Photon Avalanche Detectors (SPAD) are considered today as a possible alternative to PMTs and other semiconductor devices in several applications, like physics research, bioluminescence, Positron Emission Tomography (PET) systems, etc. We have developed and characterized a first prototype array produced by STMicroelectronics in silicon planar technology and working at low voltage (30-40 V) in Geiger mode operation. The single cell structure (size down to 20 μm) and the geometrical arrangement give rise to appealing intrinsic characteristics of the device, such as photon detection efficiency, dark count map, cross-talk effects, timing and energy resolution. New prototypes are under construction with a higher number of pixels that have a common output signal to obtain a so-called SiPM (Silicon PhotoMultiplier) configuration

  4. Improvements to the power supply and control systems of Geiger-Mueller counter tubes

    International Nuclear Information System (INIS)

    Gavin, Gerard; Amberny, Philippe.

    1977-01-01

    This invention aims to provide a power supply and control system for Geiger-Mueller counter tubes requiring only one high voltage output, corresponding to the 'active' phase voltage. With this in view, the invention proposes, inter alia, a system comprising a high voltage source connected to the anode of the GM tube whose cathode is connected to a determination and counting circuit, featuring a cathode connected to the source via an electronic switch and to earth by a component for holding the potential difference at a given level and by another electronic switch, placed in series. The switches are controlled in turn so as alternately to bring the cathode to a first voltage, enabling the tube to function, and to a second voltage, causing the blocking of the tube, this second voltage being set by the component creating the voltage difference [fr

  5. Characterisation of Geiger-mode avalanche photodiodes for medical imaging applications

    Energy Technology Data Exchange (ETDEWEB)

    Britvitch, I. [Swiss Federal Institute of Technology, CH-8092 Zurich (Switzerland)]. E-mail: Ilia.britvitch@psi.ch; Johnson, I. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Renker, D. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Stoykov, A. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Lorenz, E. [Swiss Federal Institute of Technology, CH-8092 Zurich (Switzerland); Max Planck Institute for Physics, 80805 Munich (Germany)

    2007-02-01

    Recently developed multipixel Geiger-mode avalanche photodiodes (G-APDs) are very promising candidates for the detection of light in medical imaging instruments (e.g. positron emission tomography) as well as in high-energy physics experiments and astrophysical applications. G-APDs are especially well suited for morpho-functional imaging (multimodality PET/CT, SPECT/CT, PET/MRI, SPECT/MRI). G-APDs have many advantages compared to conventional photosensors such as photomultiplier tubes because of their compact size, low-power consumption, high quantum efficiency and insensitivity to magnetic fields. Compared to avalanche photodiodes and PIN diodes, they are advantageous because of their high gain, reduced sensitivity to pick up and the so-called nuclear counter effect and lower noise. We present measurements of the basic G-APD characteristics: photon detection efficiency, gain, inter-cell crosstalk, dynamic range, recovery time and dark count rate.

  6. Characterisation of Geiger-mode avalanche photodiodes for medical imaging applications

    International Nuclear Information System (INIS)

    Britvitch, I.; Johnson, I.; Renker, D.; Stoykov, A.; Lorenz, E.

    2007-01-01

    Recently developed multipixel Geiger-mode avalanche photodiodes (G-APDs) are very promising candidates for the detection of light in medical imaging instruments (e.g. positron emission tomography) as well as in high-energy physics experiments and astrophysical applications. G-APDs are especially well suited for morpho-functional imaging (multimodality PET/CT, SPECT/CT, PET/MRI, SPECT/MRI). G-APDs have many advantages compared to conventional photosensors such as photomultiplier tubes because of their compact size, low-power consumption, high quantum efficiency and insensitivity to magnetic fields. Compared to avalanche photodiodes and PIN diodes, they are advantageous because of their high gain, reduced sensitivity to pick up and the so-called nuclear counter effect and lower noise. We present measurements of the basic G-APD characteristics: photon detection efficiency, gain, inter-cell crosstalk, dynamic range, recovery time and dark count rate

  7. Improvements to the power supply and control systems of Geiger-Mueller counter tubes

    Energy Technology Data Exchange (ETDEWEB)

    Gavin, G; Amberny, P

    1977-10-19

    This invention aims to provide a power supply and control system for Geiger-Mueller counter tubes requiring only one high voltage output, corresponding to the 'active' phase voltage. With this in view, the invention proposes, inter alia, a system comprising a high voltage source connected to the anode of the GM tube whose cathode is connected to a determination and counting circuit, featuring a cathode connected to the source via an electronic switch and to earth by a component for holding the potential difference at a given level and by another electronic switch, placed in series. The switches are controlled in turn so as alternately to bring the cathode to a first voltage, enabling the tube to function, and to a second voltage, causing the blocking of the tube, this second voltage being set by the component creating the voltage difference.

  8. Was Muller's 1946 Nobel Prize research for radiation-induced gene mutations peer-reviewed?

    Science.gov (United States)

    Calabrese, Edward J

    2018-06-06

    This historical analysis indicates that it is highly unlikely that the Nobel Prize winning research of Hermann J. Muller was peer-reviewed. The published paper of Muller lacked a research methods section, cited no references, and failed to acknowledge and discuss the work of Gager and Blakeslee (PNAS 13:75-79, 1927) that claimed to have induced gene mutation via ionizing radiation six months prior to Muller's non-data Science paper (Muller, Science 66(1699):84-87, 1927a). Despite being well acclimated into the scientific world of peer-review, Muller choose to avoid the peer-review process on his most significant publication. It appears that Muller's actions were strongly influenced by his desire to claim primacy for the discovery of gene mutation. The actions of Muller have important ethical lessons and implications today, when self-interest trumps one's obligations to society and the scientific culture that supports the quest for new knowledge and discovery.

  9. General Roy S. Geiger, USMC: Marine Aviator, Joint Force Commander

    Science.gov (United States)

    2007-06-01

    This is a strong assertion, given the significant and better-known contributions of great Marines such as John Lejeune, Smedley Butler, Alexander...While stationed in Panama, Geiger made a favorable impression on Major Smedley Butler, who later earned the Medal of Honor twice and became a...fifth Naval Aviator. 43 Johnson, 5. 44 Robert Sherrod, History of Marine Corps Aviation in World War II (Baltimore, MD: The Nautical and Aviation

  10. Analysis and modeling of optical crosstalk in InP-based Geiger-mode avalanche photodiode FPAs

    Science.gov (United States)

    Chau, Quan; Jiang, Xudong; Itzler, Mark A.; Entwistle, Mark; Piccione, Brian; Owens, Mark; Slomkowski, Krystyna

    2015-05-01

    Optical crosstalk is a major factor limiting the performance of Geiger-mode avalanche photodiode (GmAPD) focal plane arrays (FPAs). This is especially true for arrays with increased pixel density and broader spectral operation. We have performed extensive experimental and theoretical investigations on the crosstalk effects in InP-based GmAPD FPAs for both 1.06-μm and 1.55-μm applications. Mechanisms responsible for intrinsic dark counts are Poisson processes, and their inter-arrival time distribution is an exponential function. In FPAs, intrinsic dark counts and cross talk events coexist, and the inter-arrival time distribution deviates from purely exponential behavior. From both experimental data and computer simulations, we show the dependence of this deviation on the crosstalk probability. The spatial characteristics of crosstalk are also demonstrated. From the temporal and spatial distribution of crosstalk, an efficient algorithm to identify and quantify crosstalk is introduced.

  11. Science and Society in the Eugenic Thought of H. J. Muller

    Science.gov (United States)

    Allen, Garland E.

    1970-01-01

    Traces the growth of theories of eugenics during the twentieth century, focussing on the work of H. J. Muller. Concludes that "Muller's lasting contribution was to write the hereditarian attitudes associated with traditional eugenics and the environmentalist's viewpoint associated with modern sociology to obtain a humane and reasoned approach to…

  12. Construction and operating characteristics of flexible Geiger counters; Caracteristiques de construction et d'utilisation de compteurs Geiger flexibles; Konstruktsionnaya i operativnaya kharakteristiki gibkikh schetchikov Gejgera; Construccion y caracteristicas de funcionamiento de contadores Geiger flexibles

    Energy Technology Data Exchange (ETDEWEB)

    Richter, H G; Ballard, L F [Research Triangle Institute, Durham, NC (United States)

    1962-04-15

    A method has been developed for constructing flexible Geiger counters in a wide range of lengths and diameters. The counters are quite flexible: a 3-cm diam. counter can be bent to a circle of 5 cm radius. Using Q-gas (98.3% helium, 1.7% n-butane) as the counting medium, plateaux are several hundred volts long with 3% slopes and are independent of the counter configuration. Counters are constructed from tubing having a polyvinyl-chloride formulation (PVC-744 - Alpha Wire Corp.). Short segments of the plastic tubing (length {approx} 3 times the tube diameter) are slipped over a coarsely threaded aluminium mandrel. Wire is wrapped tightly in the threads and the whole is placed in a 110{sup o}C oven for 20 min. After cooling, the corrugated plastic segment is removed from the mandrel. This corrugation prevents the collapse of the tubing when it is coiled. A polystyrene disk, perforated with relatively large holes near the periphery for gas flow and having a 0.6-mm hole in the centre for the anode, is fastened in one end of each segment. By threading the segments thus prepared on a 3-mil tungsten anode and slipping one end of each segment over the adjacent segment and securing them with an adhesive, a counter of any desired length can be built up. Glass end-pieces for attaching the anode ends and for admitting and exhausting the flow gas are attached. A bare copper wire spiralled in the grooves of the counter makes a satisfactory external cathode which operates in the manner observed by MAZE. A 3-cm diam. counter, 1 m long, either linear or coiled, has a plateau beginning at 1400 V and extending beyond 1750 V with a 2.9% slope. Counting rates in excess of 300000 counts/min with little coincidence loss have been observed. Since the counter is actually a series of short Geiger counters and the discharge does not spread beyond the polystyrene spacer disks, adjacent counter segments operate independently. Pulse heights are greater than 50 mV. (author) [French] On a mis au

  13. Application of Geiger-mode photosensors in Cherenkov detectors

    Energy Technology Data Exchange (ETDEWEB)

    Gamal, Ahmed, E-mail: gamal.ahmed@assoc.oeaw.ac.a [Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, Vienna (Austria); Al-Azhar University, Faculty of Science, Physics Department, Cairo (Egypt); Paul, Buehler; Michael, Cargnelli [Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, Vienna (Austria); Roland, Hohler [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Johann, Marton [Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, Vienna (Austria); Herbert, Orth [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Ken, Suzuki [Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, Vienna (Austria)

    2011-05-21

    Silicon-based photosensors (SiPMs) working in the Geiger-mode represent an elegant solution for the readout of particle detectors working at low-light levels like Cherenkov detectors. Especially the insensitivity to magnetic fields makes this kind of sensors suitable for modern detector systems in subatomic physics which are usually employing magnets for momentum resolution. We are characterizing SiPMs of different manufacturers for selecting sensors and finding optimum operating conditions for given applications. Recently we designed and built a light concentrator prototype with 8x8 cells to increase the active photon detection area of an 8x8 SiPM (Hamamatsu MPPC S10931-100P) array. Monte Carlo studies, measurements of the collection efficiency, and tests with the MPPC were carried out. The status of these developments are presented.

  14. Adaptive aperture for Geiger mode avalanche photodiode flash ladar systems

    Science.gov (United States)

    Wang, Liang; Han, Shaokun; Xia, Wenze; Lei, Jieyu

    2018-02-01

    Although the Geiger-mode avalanche photodiode (GM-APD) flash ladar system offers the advantages of high sensitivity and simple construction, its detection performance is influenced not only by the incoming signal-to-noise ratio but also by the absolute number of noise photons. In this paper, we deduce a hyperbolic approximation to estimate the noise-photon number from the false-firing percentage in a GM-APD flash ladar system under dark conditions. By using this hyperbolic approximation function, we introduce a method to adapt the aperture to reduce the number of incoming background-noise photons. Finally, the simulation results show that the adaptive-aperture method decreases the false probability in all cases, increases the detection probability provided that the signal exceeds the noise, and decreases the average ranging error per frame.

  15. Wolfgang Geiger (17 July 1921 - 3 July 2000

    Directory of Open Access Journals (Sweden)

    Renata Boucher-Rodoni

    2000-08-01

    Full Text Available Wolfgang Geiger died on the 3rd July 2000, at the age of 79. He was born on July 17th 1921 in Biel; his mother died at his birth. His childhood was spent with his father, a well-known artist, partly in Ligerz, on Lake Biel, and partly in Porto Ronco in Ticino, on Lago Maggiore. After high school in Biel, he began his University studies, first at the Swiss Federal Institute of Technology in Zürich, then in Basel, where he studied under Professor A. Portmann. During his PhD a grant from the Janggen-Pöhn foundation enabled him to work for some months at the Institut des Pêches maritimes du Maroc, in Casablanca, with Dr. J .Furnestin. In 1953 he completed his PhD on teleost fish brain. His career as a biologist began in Bern at the Eidgenossische Inspektion für Fortwesen, Jagd und Fischerei. In 1962 he was appointed head assistant (chef des travaux at the University of Geneva, in the comparative anatomy and physiology laboratory (Dr H. J. Huggel, where he discovered the joys and the limitations of teaching. He was highly regarded as a lecturer and taught in a relaxed atmosphere of mutual respect and trust, much appreciated by his students. Professor Geiger was also the main organiser of field trips to Sète, on the French Mediterranean coast, where he was in his element living on the water. He went out on the trawlers with the students and introduced them enthusiastically to the marvels of sea fauna. He was happy during those field trips and had the knack of communicating his happiness to the students.

  16. Single ion implantation for single donor devices using Geiger mode detectors

    International Nuclear Information System (INIS)

    Bielejec, E; Seamons, J A; Carroll, M S

    2010-01-01

    Electronic devices that are designed to use the properties of single atoms such as donors or defects have become a reality with recent demonstrations of donor spectroscopy, single photon emission sources, and magnetic imaging using defect centers in diamond. Ion implantation, an industry standard for atom placement in materials, requires augmentation for single ion capability including a method for detecting a single ion arrival. Integrating single ion detection techniques with the single donor device construction region allows single ion arrival to be assured. Improving detector sensitivity is linked to improving control over the straggle of the ion as well as providing more flexibility in lay-out integration with the active region of the single donor device construction zone by allowing ion sensing at potentially greater distances. Using a remotely located passively gated single ion Geiger mode avalanche diode (SIGMA) detector we have demonstrated 100% detection efficiency at a distance of >75 μm from the center of the collecting junction. This detection efficiency is achieved with sensitivity to ∼600 or fewer electron-hole pairs produced by the implanted ion. Ion detectors with this sensitivity and integrated with a thin dielectric, for example a 5 nm gate oxide, using low energy Sb implantation would have an end of range straggle of -1 and 10 -4 for operation temperatures of ∼300 K and ∼77 K, respectively. Low temperature operation and reduced false, 'dark', counts are critical to achieving high confidence in single ion arrival. For the device performance in this work, the confidence is calculated as a probability of >98% for counting one and only one ion for a false count probability of 10 -4 at an average ion number per gated window of 0.015.

  17. Linear LIDAR versus Geiger-mode LIDAR: impact on data properties and data quality

    Science.gov (United States)

    Ullrich, A.; Pfennigbauer, M.

    2016-05-01

    LIDAR has become the inevitable technology to provide accurate 3D data fast and reliably even in adverse measurement situations and harsh environments. It provides highly accurate point clouds with a significant number of additional valuable attributes per point. LIDAR systems based on Geiger-mode avalanche photo diode arrays, also called single photon avalanche photo diode arrays, earlier employed for military applications, now seek to enter the commercial market of 3D data acquisition, advertising higher point acquisition speeds from longer ranges compared to conventional techniques. Publications pointing out the advantages of these new systems refer to the other category of LIDAR as "linear LIDAR", as the prime receiver element for detecting the laser echo pulses - avalanche photo diodes - are used in a linear mode of operation. We analyze the differences between the two LIDAR technologies and the fundamental differences in the data they provide. The limitations imposed by physics on both approaches to LIDAR are also addressed and advantages of linear LIDAR over the photon counting approach are discussed.

  18. Development of a measurement device, using a Geiger-Mueller type detector, for the determination of the activity in a 99mTc generator prototype

    International Nuclear Information System (INIS)

    Urquizo, Rafael; Gago, Javier; Mendoza, Pablo; Cruz-Saco, Cesar; Rojas, Jorge

    2014-01-01

    This article presents the implementation of a measurement system using a Geiger-Mueller detector (GM) in order to adapt it into a 99m Tc generator prototype. The response signal of the measurement system designed in terms of count rate is linearly proportional to the variation of the activity measured between 280 and 170 mCi of 99m Tc with a relative error of ± 2,8 %. However, further tests are needed to evaluate the correlation for an activity level lower than 20 mCi in order to obtain an adequate range of use. (authors).

  19. Geiger-Nuttall Law for Nuclei in Strong Electromagnetic Fields

    Science.gov (United States)

    Delion, D. S.; Ghinescu, S. A.

    2017-11-01

    We investigate the influence of a strong laser electromagnetic field on the α -decay rate by using the Hennenberger frame of reference. We introduce an adimensional parameter D =S0/R0, where R0 is the geometrical nuclear radius and S0˜√{I }/ω2 is a length parameter depending on the laser intensity I and frequency ω . We show that the barrier penetrability has a strong increase for intensities corresponding to D >Dcrit=1 , due to the fact that the resulting Coulomb potential becomes strongly anisotropic even for spherical nuclei. As a consequence, the contribution of the monopole term increases the barrier penetrability by 2 orders of magnitude, while the total contribution has an effect of 6 orders of magnitude at D ˜3 Dcrit. In the case of deformed nuclei, the electromagnetic field increases the penetrability by an additional order of magnitude for a quadrupole deformation β2˜0.3 . The influence of the electromagnetic field can be expressed in terms of a shifted Geiger-Nuttal law by a term depending on S0 and deformation.

  20. A time averaged background compensator for Geiger-Mueller counters

    International Nuclear Information System (INIS)

    Bhattacharya, R.C.; Ghosh, P.K.

    1983-01-01

    The GM tube compensator described stores background counts to cancel an equal number of pulses from the measuring channel providing time averaged compensation. The method suits portable instruments. (orig.)

  1. Characterization of new hexagonal large area Geiger Avalanche Photodiodes

    International Nuclear Information System (INIS)

    Boccone, V.; Aguilar, J.A.; Della Volpe, D.; Christov, A.; Montaruli, T.; Rameez, M.; Basili, A.

    2013-06-01

    Photomultipliers (PMTs) are the standard detector for construction of the current generation of imaging Atmospheric Cherenkov Telescopes (IACTs). Despite impressive improvements in QE and reliability in the last years, these devices suffer from the limitation of being unable to operate in the partially illuminated sky (during full or partial moon periods) as the excess light leads to a significant increase in the rate of ageing of the devices themselves and consequently limit the life of the camera. A viable alternative is the large area Geiger-mode avalanche photodiodes (G-APDs also known as Silicon Photomultipliers or SiPMs) that are commercially available from different producers in various types and dimensions. The sufficiency of the maturity of this technology for application to Cherenkov Astronomy has already been demonstrated by the FACT telescope. One of the camera designs under study for the 4 m Davies Cotton Telescope foresees the utilization of a large area G-APDs coupled to non imaging light concentrators. In collaboration with Hamamatsu and deriving from their current technology, we have designed a new hexagonal shaped large area G-APD HEX S12516 which when coupled to a Winston cone of 24 degrees cutting angle allows for a pixel angular resolution of 0.25 degrees for a f/D 1.4 telescope with a diameter of 4 m. The device, available in 2 different cell size configurations (50 μm and 100 μm), is divided into 4 different channels powered in common cathode mode. A temperature sensor was included for a better temperature evaluation in the characterization phase. The first 3 prototypes were fully characterized and the results are compared to the larger area devices commercially available such as the S10985-050C (2x2 array of 3x3 mm 2 G-APDs). The photo-detection efficiency is measured applying the Poisson statistics method using pulsed LED at 7 different wavelengths from 355 to 670 nm and for different bias over-voltages (V ov ). Optical crosstalk and

  2. Geiger-mueller radiation detector with means for detecting and indicating the existence of radiation overload

    International Nuclear Information System (INIS)

    Kovacs, T.; Mills, A.P.; Pfeiffer, L.N.

    1981-01-01

    When subjected to radiation overload existing geiger-mueller counters may give an erroneously low reading, resulting in possible hazard to personnel. The instant invention discloses simple and inexpensive apparatus to remedy this dangerous shortcoming. Depending on the geometry of the detector tube, two possible failure modes have been identified, and circuitry is disclosed to detect the existence of these respective failure modes. The disclosed apparatus indicates the absence of an overload condition, in addition to signaling, by both visible and audible means, the existence of excessive radiation that might result in erroneously low reading of the geiger-mueller counter

  3. Turning randomness into meaning at the molecular level using Muller's morphs.

    Science.gov (United States)

    Henson, Kathleen; Cooper, Melanie M; Klymkowsky, Michael W

    2012-04-15

    While evolutionary theory follows from observable facts and logical inferences (Mayr, 1985), historically, the origin of novel inheritable variations was a major obstacle to acceptance of natural selection (Bowler, 1992; Bowler, 2005). While molecular mechanisms address this issue (Jablonka and Lamb, 2005), analysis of responses to the Biological Concept Inventory (BCI) (Klymkowsky et al., 2010), revealed that molecular biology majors rarely use molecular level ideas in their discourse, implying that they do not have an accessible framework within which to place evolutionary variation. We developed a "Socratic tutorial" focused on Muller's categorization of mutations' phenotypic effects (Muller, 1932). Using a novel vector-based method to analyzed students' essay responses, we found that a single interaction with this tutorial led to significant changes in thinking toward a clearer articulation of the effects of mutational change. We suggest that Muller's morphs provides an effective framework for facilitating student learning about mutational effects and evolutionary mechanisms.

  4. Turning randomness into meaning at the molecular level using Muller's morphs

    Directory of Open Access Journals (Sweden)

    Kathleen Henson

    2012-02-01

    While evolutionary theory follows from observable facts and logical inferences (Mayr, 1985, historically, the origin of novel inheritable variations was a major obstacle to acceptance of natural selection (Bowler, 1992; Bowler, 2005. While molecular mechanisms address this issue (Jablonka and Lamb, 2005, analysis of responses to the Biological Concept Inventory (BCI (Klymkowsky et al., 2010, revealed that molecular biology majors rarely use molecular level ideas in their discourse, implying that they do not have an accessible framework within which to place evolutionary variation. We developed a “Socratic tutorial” focused on Muller's categorization of mutations' phenotypic effects (Muller, 1932. Using a novel vector-based method to analyzed students' essay responses, we found that a single interaction with this tutorial led to significant changes in thinking toward a clearer articulation of the effects of mutational change. We suggest that Muller's morphs provides an effective framework for facilitating student learning about mutational effects and evolutionary mechanisms.

  5. A Low-Level Geiger-Counter for Tritium; Compteur Geiger a faible mouvement propre pour le tritium; Schetchik Gejgera s nizkim urovnem dlya tritiya; Contador Geiger de baja actividad de fondo para tritio

    Energy Technology Data Exchange (ETDEWEB)

    Von Buttlar, H; Stahl, W [Technische Hochschule, Darmstadt (Germany)

    1962-01-15

    A cylindrical counter tube of volume 11 l was constructed which contains a number of anticoincidence wires surrounding a 2.9 l effective-volume centre-counter. The centre counter is separated from the anticoincidence section by a thin aluminized Hostaphan foil. Details of the construction are given. The counter filling gas consists of 30 mm ethylene, 40 mm argon and up to 700 mm sample hydrogen. An external quenching circuit with a 7 msec dead time effectively eliminates after-pulses. In a 30 cm iron shield, the counting rates of the centre counter with dead hydrogen gas are 350 counts/min without and about 3 counts/min with the anticoincidence circuit in operation. If it is assumed that 1 count/min above background is significant, a T/H ratio of as low as 10{sup -16} can be measured without isotope enrichment. Experiments are in progress to check the longtime stability of the arrangement. (author) [French] Les auteurs ont monte un tube compteur cylindrique d'un volume de 11 litres qui contient un certain nombre de conducteurs d'anticoincidence entourant un compteur central d'un volume reel de 2,9 litres. Ce compteur central est separe de la zone d'anticoincidence par une feuille mince d' ''Hostaphan'' recouverte d'aluminium. Les auteurs donnent des details sur le montage de l'appareil. Le melange gazeux remplissant le compteur se compose d'ethylene (30 mm), d'argon (40 mm) et de l'echantillon d'hydrogene (jusqu' a 700 mm). Un circuit coupeur externe ayant un temps mort de 7 ms elimine efficacement les impulsions retardees. Avec une protection de fer de 30 cm, les taux de comptage du compteur central, rempli d'hydrogene inerte, sont de 350 coups par minute et d'environ 3 coups par minute, selon que le circuit d'anticoincidence fonctionne ou non. Si l'on suppose qu'un coup par minute au-dessus du bruit de fond est significatif, on peut mesurer des rapports T/H jusqu' a 10{sup -16} sans avoir a proceder a un enrichissement. On effectue actuellement des experiences

  6. Geiger-Mueller counter for mixed neutron-gamma beam dosimetry

    International Nuclear Information System (INIS)

    McDonald, J.C.; Ma, I.-C.

    1978-01-01

    A Geiger-Mueller (G-M) dosimeter has been constructed and employed to measure the gamma-ray component of absorbed dose in a cyclotron produced fast neutron field. This instrument is waterproof for measurements in a liquid medium, and read-out is accompanied with any standard scaler. (Auth.)

  7. Updated world map of the Köppen-Geiger climate classification

    Directory of Open Access Journals (Sweden)

    M. C. Peel

    2007-10-01

    Full Text Available Although now over 100 years old, the classification of climate originally formulated by Wladimir Köppen and modified by his collaborators and successors, is still in widespread use. It is widely used in teaching school and undergraduate courses on climate. It is also still in regular use by researchers across a range of disciplines as a basis for climatic regionalisation of variables and for assessing the output of global climate models. Here we have produced a new global map of climate using the Köppen-Geiger system based on a large global data set of long-term monthly precipitation and temperature station time series. Climatic variables used in the Köppen-Geiger system were calculated at each station and interpolated between stations using a two-dimensional (latitude and longitude thin-plate spline with tension onto a 0.1°×0.1° grid for each continent. We discuss some problems in dealing with sites that are not uniquely classified into one climate type by the Köppen-Geiger system and assess the outcomes on a continent by continent basis. Globally the most common climate type by land area is BWh (14.2%, Hot desert followed by Aw (11.5%, Tropical savannah. The updated world Köppen-Geiger climate map is freely available electronically in the Supplementary Material Section.

  8. Geiger-Mode Avalanche Photodiode Arrays Integrated to All-Digital CMOS Circuits.

    Science.gov (United States)

    Aull, Brian

    2016-04-08

    This article reviews MIT Lincoln Laboratory's work over the past 20 years to develop photon-sensitive image sensors based on arrays of silicon Geiger-mode avalanche photodiodes. Integration of these detectors to all-digital CMOS readout circuits enable exquisitely sensitive solid-state imagers for lidar, wavefront sensing, and passive imaging.

  9. Quantifying the threat of extinction from Muller's ratchet in the diploid Amazon molly (Poecilia formosa

    Directory of Open Access Journals (Sweden)

    Loewe Laurence

    2008-03-01

    Full Text Available Abstract Background The Amazon molly (Poecilia formosa is a small unisexual fish that has been suspected of being threatened by extinction from the stochastic accumulation of slightly deleterious mutations that is caused by Muller's ratchet in non-recombining populations. However, no detailed quantification of the extent of this threat is available. Results Here we quantify genomic decay in this fish by using a simple model of Muller's ratchet with the most realistic parameter combinations available employing the evolution@home global computing system. We also describe simple extensions of the standard model of Muller's ratchet that allow us to deal with selfing diploids, triploids and mitotic recombination. We show that Muller's ratchet creates a threat of extinction for the Amazon molly for many biologically realistic parameter combinations. In most cases, extinction is expected to occur within a time frame that is less than previous estimates of the age of the species, leading to a genomic decay paradox. Conclusion How then does the Amazon molly survive? Several biological processes could individually or in combination solve this genomic decay paradox, including paternal leakage of undamaged DNA from sexual sister species, compensatory mutations and many others. More research is needed to quantify the contribution of these potential solutions towards the survival of the Amazon molly and other (ancient asexual species.

  10. Regulation of Taurine transporter activity in cultured rat retinal ganglion cells and rat retinal Muller Cells

    International Nuclear Information System (INIS)

    Eissa, Laila A.; Smith, Sylvia B.; El-sherbeny, Amira A.

    2006-01-01

    Diabetic retinopathy is one of the most common complications of diabetes. The amino acid taurine is believed to play an antioxidant protective role in diabetic retinopathy through the scavenging of the reactive species. It is not well established whether taurine uptake is altered in retina cells during diabetic conditions. Thus, the present study was designed to investigate the changes in taurine transport in cultures of rat retinal Muller cells and rat retinal ganglion cells under conditions associated with diabetes. Taurine was abundantly taken up by retinal Muller cells and rat retinal ganglion cells under normal glycemic condition. Taurine was actively transported to rat Muller cells and rat retinal ganglion cells in a Na and Cl dependant manner. Taurine uptake further significantly elevated in both type of cells after the incubation with high glucose concentration. This effect could be attributed to the increase in osmolarity. Because Nitric Oxide (NO) is a molecule implicated in the pathogenesis of diabetes, we also determined the activity of taurine transporter in cultured rat retinal Muller cells and rat retinal ganglion cells in the presence of the NO donors, SIN-1 and SNAP. Taurine uptake was elevated above control value after 24-h incubation with low concentration of NO donors. We finally investigated the ability of neurotoxic glutamate to change taurine transporter activity in both types of cells. Uptake of taurine was significantly increased in rat retinal ganglion cells when only incubated with high concentration of glutamate. Our data provide evidence that taurine transporter is present in cultured rat retinal ganglion and Muller cells and is regulated by hyperosmolarity. The data are relevant to disease such as diabetes and neuronal degeneration where retinal cell volume may dramatically change. (author)

  11. RBC count

    Science.gov (United States)

    ... by kidney disease) RBC destruction ( hemolysis ) due to transfusion, blood vessel injury, or other cause Leukemia Malnutrition Bone ... slight risk any time the skin is broken) Alternative Names Erythrocyte count; Red blood cell count; Anemia - RBC count Images Blood test ...

  12. Counting carbohydrates

    Science.gov (United States)

    Carb counting; Carbohydrate-controlled diet; Diabetic diet; Diabetes-counting carbohydrates ... Many foods contain carbohydrates (carbs), including: Fruit and fruit juice Cereal, bread, pasta, and rice Milk and milk products, soy milk Beans, legumes, ...

  13. Generation efficiency of single-photon current pulses in the Geiger mode of silicon avalanche photodiodes

    International Nuclear Information System (INIS)

    Verkhovtseva, A. V.; Gergel, V. A.

    2009-01-01

    Statistical fluctuations of the avalanche's multiplication efficiency were studied as applied to the single-photon (Geiger) mode of avalanche photodiodes. The distribution function of partial multiplication factors with an anomalously wide (of the order of the average) dispersion was obtained. Expressions for partial feedback factors were derived in terms of the average gain and the corresponding dependences on the diode's overvoltage were calculated. Final expressions for the photon-electric pulse's conversion were derived by averaging corresponding formulas over the coordinate of initiating photoelectron generation using the functions of optical photon absorption in silicon.

  14. Amplitude and timing properties of a Geiger discharge in a SiPM cell

    Energy Technology Data Exchange (ETDEWEB)

    Popova, E., E-mail: elenap73@mail.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Kashirskoe Shosse 31 (Russian Federation); Buzhan, P.; Pleshko, A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Kashirskoe Shosse 31 (Russian Federation); Vinogradov, S. [University of Liverpool and Cockcroft Institute, Sci-Tech Daresbury, Keckwick Lane, Warrington WA4 4AD, Cheshire (United Kingdom); P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Leninskiy Prospect 53, Moscow 119991 (Russian Federation); Stifutkin, A.; Ilyin, A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Kashirskoe Shosse 31 (Russian Federation); Besson, D. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Kashirskoe Shosse 31 (Russian Federation); Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045-2151 (United States); Mirzoyan, R. [Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 München (Germany)

    2015-07-01

    The amplitude and timing properties of a Geiger discharge in a stand-alone SiPM cell have been investigated in detail. Use of a single stand-alone SiPM cell allows us to perform measurements with better accuracy than the multicell structure of conventional SiPMs. We have studied the dependence of the output charge and amplitude from an SiPM cell illuminated by focused light vs the number of primary photoelectrons. We propose a SPICE model which explains the amplitude over saturation (when the SiPM's amplitude is greater than the sum over all cells) characteristics of SiPM signals for more than one initial photoelectrons. The time resolutions of a SiPM cell have been measured for the case of single (SPTR) and multiphoton light pulses. The Full Width Half Max (FWHM) for SPTR has been found to be at the level of 30 ps for focused and 40 ps for unfocused light (100 μm cell size). - Highlights: • A stand-alone SiPM cell has been investigated in detail. • Amplitude and time properties have been measured with femtosecond 660 nm laser. • SPICE model for a Geiger discharge development has been proposed. • SPTR for a stand-alone 100 μm size SiPM cell has been found to be 40 ps FWHM.

  15. "ON ALGEBRAIC DECODING OF Q-ARY REED-MULLER AND PRODUCT REED-SOLOMON CODES"

    Energy Technology Data Exchange (ETDEWEB)

    SANTHI, NANDAKISHORE [Los Alamos National Laboratory

    2007-01-22

    We consider a list decoding algorithm recently proposed by Pellikaan-Wu for q-ary Reed-Muller codes RM{sub q}({ell}, m, n) of length n {le} q{sup m} when {ell} {le} q. A simple and easily accessible correctness proof is given which shows that this algorithm achieves a relative error-correction radius of {tau} {le} (1-{radical}{ell}q{sup m-1}/n). This is an improvement over the proof using one-point Algebraic-Geometric decoding method given in. The described algorithm can be adapted to decode product Reed-Solomon codes. We then propose a new low complexity recursive aJgebraic decoding algorithm for product Reed-Solomon codes and Reed-Muller codes. This algorithm achieves a relative error correction radius of {tau} {le} {Pi}{sub i=1}{sup m} (1 - {radical}k{sub i}/q). This algorithm is then proved to outperform the Pellikaan-Wu algorithm in both complexity and error correction radius over a wide range of code rates.

  16. Fault-tolerant conversion between adjacent Reed-Muller quantum codes based on gauge fixing

    Science.gov (United States)

    Quan, Dong-Xiao; Zhu, Li-Li; Pei, Chang-Xing; Sanders, Barry C.

    2018-03-01

    We design forward and backward fault-tolerant conversion circuits, which convert between the Steane code and the 15-qubit Reed-Muller quantum code so as to provide a universal transversal gate set. In our method, only seven out of a total 14 code stabilizers need to be measured, and we further enhance the circuit by simplifying some stabilizers; thus, we need only to measure eight weight-4 stabilizers for one round of forward conversion and seven weight-4 stabilizers for one round of backward conversion. For conversion, we treat random single-qubit errors and their influence on syndromes of gauge operators, and our novel single-step process enables more efficient fault-tolerant conversion between these two codes. We make our method quite general by showing how to convert between any two adjacent Reed-Muller quantum codes \\overline{\\textsf{RM}}(1,m) and \\overline{\\textsf{RM}}≤ft(1,m+1\\right) , for which we need only measure stabilizers whose number scales linearly with m rather than exponentially with m obtained in previous work. We provide the explicit mathematical expression for the necessary stabilizers and the concomitant resources required.

  17. Counting cormorants

    DEFF Research Database (Denmark)

    Bregnballe, Thomas; Carss, David N; Lorentsen, Svein-Håkon

    2013-01-01

    This chapter focuses on Cormorant population counts for both summer (i.e. breeding) and winter (i.e. migration, winter roosts) seasons. It also explains differences in the data collected from undertaking ‘day’ versus ‘roost’ counts, gives some definitions of the term ‘numbers’, and presents two...

  18. Radiation level measured by a portable Geiger-Mueller counter at the altitude of commercial air routes

    International Nuclear Information System (INIS)

    Araki, Takashi

    1995-01-01

    The background intensities of naturally occurring radiation were measured aboard scheduled commercial airplanes using a newly developed Geiger-Mueller counter with a pocket computer. The preliminary results show that the radiation at the cruising altitude of a commercial airplane on a transcontinental flight is 40 times higher than the ground-level. (author)

  19. Evaluation of single photon and Geiger mode Lidar for the 3D Elevation Program

    Science.gov (United States)

    Stoker, Jason M.; Abdullah, Qassim; Nayegandhi, Amar; Winehouse, Jayna

    2016-01-01

    Data acquired by Harris Corporation’s (Melbourne, FL, USA) Geiger-mode IntelliEarth™ sensor and Sigma Space Corporation’s (Lanham-Seabrook, MD, USA) Single Photon HRQLS sensor were evaluated and compared to accepted 3D Elevation Program (3DEP) data and survey ground control to assess the suitability of these new technologies for the 3DEP. While not able to collect data currently to meet USGS lidar base specification, this is partially due to the fact that the specification was written for linear-mode systems specifically. With little effort on part of the manufacturers of the new lidar systems and the USGS Lidar specifications team, data from these systems could soon serve the 3DEP program and its users. Many of the shortcomings noted in this study have been reported to have been corrected or improved upon in the next generation sensors.

  20. Tower counts

    Science.gov (United States)

    Woody, Carol Ann; Johnson, D.H.; Shrier, Brianna M.; O'Neal, Jennifer S.; Knutzen, John A.; Augerot, Xanthippe; O'Neal, Thomas A.; Pearsons, Todd N.

    2007-01-01

    Counting towers provide an accurate, low-cost, low-maintenance, low-technology, and easily mobilized escapement estimation program compared to other methods (e.g., weirs, hydroacoustics, mark-recapture, and aerial surveys) (Thompson 1962; Siebel 1967; Cousens et al. 1982; Symons and Waldichuk 1984; Anderson 2000; Alaska Department of Fish and Game 2003). Counting tower data has been found to be consistent with that of digital video counts (Edwards 2005). Counting towers do not interfere with natural fish migration patterns, nor are fish handled or stressed; however, their use is generally limited to clear rivers that meet specific site selection criteria. The data provided by counting tower sampling allow fishery managers to determine reproductive population size, estimate total return (escapement + catch) and its uncertainty, evaluate population productivity and trends, set harvest rates, determine spawning escapement goals, and forecast future returns (Alaska Department of Fish and Game 1974-2000 and 1975-2004). The number of spawning fish is determined by subtracting subsistence, sport-caught fish, and prespawn mortality from the total estimated escapement. The methods outlined in this protocol for tower counts can be used to provide reasonable estimates ( plus or minus 6%-10%) of reproductive salmon population size and run timing in clear rivers. 

  1. Description and phylogeny of a new microsporidium from the elm leaf beetle, Xanthogaleruca luteola Muller, 1766 (Coleoptera: Chrysomelidae)

    Science.gov (United States)

    This study describes a new genus and species of microsporidia which is a pathogen of the elm leaf beetle, Xanthogaleruca luteola Muller, 1776 (Coleoptera: Chrysomelidae). The beetles were collected from Istanbul in Turkey. All developmental stages are uninucleate and in direct contact with the host ...

  2. On locality of Generalized Reed-Muller codes over the broadcast erasure channel

    KAUST Repository

    Alloum, Amira

    2016-07-28

    One to Many communications are expected to be among the killer applications for the currently discussed 5G standard. The usage of coding mechanisms is impacting broadcasting standard quality, as coding is involved at several levels of the stack, and more specifically at the application layer where Rateless, LDPC, Reed Slomon codes and network coding schemes have been extensively studied, optimized and standardized in the past. Beyond reusing, extending or adapting existing application layer packet coding mechanisms based on previous schemes and designed for the foregoing LTE or other broadcasting standards; our purpose is to investigate the use of Generalized Reed Muller codes and the value of their locality property in their progressive decoding for Broadcast/Multicast communication schemes with real time video delivery. Our results are meant to bring insight into the use of locally decodable codes in Broadcasting. © 2016 IEEE.

  3. Antifeedant compounds from three species of Apiaceae active against the field slug, Deroceras reticulatum (Muller).

    Science.gov (United States)

    Birkett, Michael A; Dodds, Catherine J; Henderson, Ian F; Leake, Lucy D; Pickett, John A; Selby, Martin J; Watson, Peter

    2004-03-01

    Extracts of volatiles from foliage of three plants in the Apiaceae, Conium maculatum L. (hemlock), Coriandrum sativum L. (coriander), and Petroselinum crispum Mill. (Nym.) (parsley), previously shown to exhibit antifeedant activity in assays with the field slug, Deroceras reticulatum (Muller) (Limacidae: Pulmonata), were studied further to identify the active components. Coupled gas chromatography-mass spectrometry (GC-MS) and neurophysiological assays using tentacle nerve preparations resulted in the identification of 11 active compounds from the three extracts. Wheat flour feeding bioassays were used to determine which of these compounds had the highest antifeedant activity. One of the most active compounds was the alkaloid gamma-coniceine, from C. maculatum. The role of potentially toxic alkaloids as semiochemicals and the potential for using such compounds as crop protection agents to prevent slug feeding damage is discussed.

  4. Tear function and ocular surface after Muller muscle-conjunctival resection.

    Science.gov (United States)

    Uğurbaş, Suat Hayri; Alpay, Atilla; Bahadır, Burak; Uğurbaş, Sılay Cantürk

    2014-05-01

    Muller muscle-conjunctival resection (MCR) is a surgical technique to correct mild and moderate ptosis. In this study, tear function tests and ocular surface are evaluated in patients who underwent unilateral surgery. Sixteen patients with normal preoperative tear function who underwent unilateral MCR were evaluated prospectively. The fellow eyes of the patients were taken as the control group. A dry eye assessment questionnaire, Schirmer testing, tear film break-up time, fluorescein stain, Rose-Bengal stain, and conjunctival impression cytology were used to assess the tear film functions and ocular surface changes in the operated and non-operated eyes. There was no statistically significant difference in the tear function tests and goblet cell densities between the operated and non-operated eyes. The results indicate that an MCR procedure has no apparent effect on tear function tests and goblet cell density in patients with normal preoperative tear function.

  5. On the absolute measure of Beta activities

    International Nuclear Information System (INIS)

    Sanchez del Rio, C.; Jimenez Reynaldo, O.; Rodriguez Mayquez, E.

    1956-01-01

    A new method for absolute beta counting of solid samples is given. The mea surements is made with an inside Geiger-Muller tube of new construction. The backscattering correction when using an infinite thick mounting is discussed and results for different materials given. (Author)

  6. On the absolute measure of Beta activities; Sobre la medida absoluta de actividades Beta

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez del Rio, C; Jimenez Reynaldo, O; Rodriguez Mayquez, E

    1956-07-01

    A new method for absolute beta counting of solid samples is given. The measurements is made with an inside Geiger-Muller tube of new construction. The backscattering correction when using an infinite thick mounting is discussed and results for different materials given. (Author)

  7. Hydrological Climate Classification: Can We Improve on Köppen-Geiger?

    Science.gov (United States)

    Knoben, W.; Woods, R. A.; Freer, J. E.

    2017-12-01

    Classification is essential in the study of complex natural systems, yet hydrology so far has no formal way to structure the climate forcing which underlies hydrologic response. Various climate classification systems can be borrowed from other disciplines but these are based on different organizing principles than a hydrological classification might use. From gridded global data we calculate a gridded aridity index, an aridity seasonality index and a rain-vs-snow index, which we use to cluster global locations into climate groups. We then define the membership degree of nearly 1100 catchments to each of our climate groups based on each catchment's climate and investigate the extent to which streamflow responses within each climate group are similar. We compare this climate classification approach with the often-used Köppen-Geiger classification, using statistical tests based on streamflow signature values. We find that three climate indices are sufficient to distinguish 18 different climate types world-wide. Climates tend to change gradually in space and catchments can thus belong to multiple climate groups, albeit with different degrees of membership. Streamflow responses within a climate group tend to be similar, regardless of the catchments' geographical proximity. A Wilcoxon two-sample test based on streamflow signature values for each climate group shows that the new classification can distinguish different flow regimes using this classification scheme. The Köppen-Geiger approach uses 29 climate classes but is less able to differentiate streamflow regimes. Climate forcing exerts a strong control on typical hydrologic response and both change gradually in space. This makes arbitrary hard boundaries in any classification scheme difficult to defend. Any hydrological classification should thus acknowledge these gradual changes in forcing. Catchment characteristics (soil or vegetation type, land use, etc) can vary more quickly in space than climate does, which

  8. Study of multi-pixel Geiger-mode avalanche photodiodes as a read-out for PET

    CERN Document Server

    Musienko, Yuri; Lecoq, Paul; Reucroft, Stephen; Swain, John; Trummer, Julia

    2007-01-01

    We have studied the performance of two multi-pixel Geiger-mode APDs (recently developed by the Centre of Perspective Technologies and Apparatus (CPTA) in Moscow) with 1×1 mm2 and 3×3 mm2 sensitive area as a readout for LSO and LYSO scintillator crystals. Energy and timing spectra were measured using a 22Na γ-source. The results of this study allow us to conclude that this photodetector is a very promising candidate for PET applications.

  9. Study and realization of pixelated APD Geiger photodetectors of very high sensitivity for Very High Energy gamma astronomy

    International Nuclear Information System (INIS)

    Jradi, K.

    2010-07-01

    Very High Energy gamma ray astronomy uses till now exclusively as detector the Photomultiplier Tube (PMT) to collect weak light flux of atmospheric showers. But an alternative is now emerging: Avalanche Photodiodes polarized in Geiger mode called 'Geiger-APD'. The PMT is a detector designed in the 70's which presents many advantages but also suffers from several drawbacks: size, weight, cost, sensitivity to magnetic field but especially difficulty to realize its pixelation in matrix. Geiger-APDs are semi-conductor devices made of PN junction integrated in a special technology to detect very low light flux, thanks to the polarization beyond the avalanche voltage. Geiger-APD presents very high photoelectron gain (∼106) strongly dependant on the polarization voltage beyond avalanche. These photodiodes present many advantages with respect to PMT, mainly as concerns miniaturization for applications based on imaging, such as the detection of Cerenkov flashes in gamma ray astronomy. In this thesis, we present the study, the design and the realization of a technological structure, based on Silicon. This structure has shown reliability to detect weak luminous flux with breakdown voltage at 12 V and dark current below 10 pA at breakdown. We also developed several models, physical and electrical, necessary to the technological optimization, as well to the development of control and readout circuits, i.e. the basis of any imaging technology. The work presented here consists in the study, the design and the realization of a matrix of high sensitivity pixels. A project of a Cerenkov telescope based on this innovative technology is also presented. (author)

  10. Counting probe

    International Nuclear Information System (INIS)

    Matsumoto, Haruya; Kaya, Nobuyuki; Yuasa, Kazuhiro; Hayashi, Tomoaki

    1976-01-01

    Electron counting method has been devised and experimented for the purpose of measuring electron temperature and density, the most fundamental quantities to represent plasma conditions. Electron counting is a method to count the electrons in plasma directly by equipping a probe with the secondary electron multiplier. It has three advantages of adjustable sensitivity, high sensitivity of the secondary electron multiplier, and directional property. Sensitivity adjustment is performed by changing the size of collecting hole (pin hole) on the incident front of the multiplier. The probe is usable as a direct reading thermometer of electron temperature because it requires to collect very small amount of electrons, thus it doesn't disturb the surrounding plasma, and the narrow sweep width of the probe voltage is enough. Therefore it can measure anisotropy more sensitively than a Langmuir probe, and it can be used for very low density plasma. Though many problems remain on anisotropy, computer simulation has been carried out. Also it is planned to provide a Helmholtz coil in the vacuum chamber to eliminate the effect of earth magnetic field. In practical experiments, the measurement with a Langmuir probe and an emission probe mounted to the movable structure, the comparison with the results obtained in reverse magnetic field by using a Helmholtz coil, and the measurement of ionic sound wave are scheduled. (Wakatsuki, Y.)

  11. The final spawning ground of Tachypleus gigas (Muller, 1785) on the east Peninsular Malaysia is at risk: A call for action.

    Digital Repository Service at National Institute of Oceanography (India)

    Nelson, B.R.; Satyanarayan, B.; Moh, J.H.Z.; Ikhwanuddin, M.; Chatterji, A.; Shaharom, F.

    Tanjung Selongor and Pantai Balok (State Pahang) are the only two places known for spawning activity of the Malaysian horseshoe crab - Tachypleus gigas (Muller, 1785) on the east coast of Peninsular Malaysia. While the former beach has been...

  12. In-situ stabilization of the Geiger (C and M Oil) Superfund Site

    International Nuclear Information System (INIS)

    Andromalos, K.B.; Ameel, M.E.

    1994-01-01

    The Geiger (C and M Oil) Superfund Site is the first US Army Corps of Engineers managed soil remediation project which utilized the in-situ stabilization/solidification technique to remediate the soil. This project involved the remediation of approximately 23,000 cubic yards of contaminated soil. Contaminants of concern included chromium, lead, PCB'S, toluene, benzene, and other organic compounds. Clean-up criteria for the stabilized material was equal to the National Primary Drinking Water Regulations, when tested using the TCLP leachate extraction method. Chromium, lead, and toluene were the main contaminants of concern, with TCLP clean-up goals of 150, 15 and 1,000 parts per billion (ppb), respectively. This National Priorities List (NPL) site is located near Charleston, SC and was an abandoned old waste oil facility that utilized unlined shallow trenches for the storage of waste oil. This paper summarizes the initial testing programs and the final production work at the site. Extensive testing was performed throughout all phases of the project. This testing was performed for the purpose of mix optimization, quality assurance, and verification testing. Specific parameters tested included: TCLP testing of organics, metals and PCBs, permeability testing, and unconfirmed compression strength

  13. André B. Muller (25.9.1918-1.4.2006)

    Science.gov (United States)

    West, R. M.

    2006-06-01

    With great sadness, we have learned about the death of André Muller on 1 April, at the age of 87. Living in retirement in his native Holland since 1983, he was one of ESOs true pioneers, an outstanding representative of the select group of European astronomers who succeeded in steering ESO through the difficult initial phases. André was close-ly associated with the entire process, from the first site monitoring programmes in South Africa to the subsequent search in Chile, the decision in favour of the La Silla site, as well as the management of ESOs early activities in Chile, includ-ing the construction of the headquarters and observatory and the installation of the first generation of ESO telescopes. Few persons, if any, have been so inti-mately connected to the setting-up of ESOs facilities and it would be impossible to list in detail all of the services André performed for the organisation with such great expertise and zeal during his long career.

  14. Clonal interference and Muller's ratchet in spatial habitats

    International Nuclear Information System (INIS)

    Otwinowski, Jakub; Krug, Joachim

    2014-01-01

    Competition between independently arising beneficial mutations is enhanced in spatial populations due to the linear rather than exponential growth of clones. Recent theoretical studies have pointed out that the resulting fitness dynamics is analogous to a surface growth process, where new layers nucleate and spread stochastically, leading to the build up of scale-invariant roughness. This scenario differs qualitatively from the standard view of adaptation in that the speed of adaptation becomes independent of population size while the fitness variance does not. Here we exploit recent progress in the understanding of surface growth processes to obtain precise predictions for the universal, non-Gaussian shape of the fitness distribution for one-dimensional habitats, which are verified by simulations. When the mutations are deleterious rather than beneficial the problem becomes a spatial version of Muller's ratchet. In contrast to the case of well-mixed populations, the rate of fitness decline remains finite even in the limit of an infinite habitat, provided the ratio U d /s 2 between the deleterious mutation rate and the square of the (negative) selection coefficient is sufficiently large. Using, again, an analogy to surface growth models we show that the transition between the stationary and the moving state of the ratchet is governed by directed percolation. (paper)

  15. Counting Possibilia

    Directory of Open Access Journals (Sweden)

    Alfredo Tomasetta

    2010-06-01

    Full Text Available Timothy Williamson supports the thesis that every possible entity necessarily exists and so he needs to explain how a possible son of Wittgenstein’s, for example, exists in our world:he exists as a merely possible object (MPO, a pure locus of potential. Williamson presents a short argument for the existence of MPOs: how many knives can be made by fitting together two blades and two handles? Four: at the most two are concrete objects, the others being merely possible knives and merely possible objects. This paper defends the idea that one can avoid reference and ontological commitment to MPOs. My proposal is that MPOs can be dispensed with by using the notion of rules of knife-making. I first present a solution according to which we count lists of instructions - selected by the rules - describing physical combinations between components. This account, however, has its own difficulties and I eventually suggest that one can find a way out by admitting possible worlds, entities which are more commonly accepted - at least by philosophers - than MPOs. I maintain that, in answering Williamson’s questions, we count classes of physically possible worlds in which the same instance of a general rule is applied.

  16. The Measurement of Natural Tritium Levels in Geiger Counters; Determination quantitative du tritium naturel par compteurs Geiger; Izmerenie urovnej estestvennogo tritiya v schetchikakh Gejgera; Medicion de concentraciones naturales de tritio mediante contadores Geiger

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, B J [Institute of Nuclear Sciences, Gracefield (New Zealand)

    1962-01-15

    A method for the counting of tritium in a 300 ml gas counter with internal quenching gases is described. Originally a system with ethylene-argon as a quenching gas was used in conjunction with an anticoincidence ring. The anticoincidence count-rate plateau characteristics were unsatisfactory at low count rates because of unsatisfactory quenching, and a search was made for more efficient quenching gases. The source of the background count-rate plateau slope is discussed, and the properties required of a suitable quenching gas for hydrogen counting are given. Results of a study made of the counting characteristics of hydrogen quenched with benzene, ethyl-bromide, ethyl-ether, isopropyl amine, hexane, ethylamine and isoprene are given. Ethylamine and ether in particular gave very satisfactory quenching characteristics. A counting system with a counter filled with 40 cm of hydrogen and quenchcd with ethylamine is described. The background rate is 3 cpm with a comparatively flat background plateau. (author) [French] L'auteur decrit une methode de dosage du tritium au moyen d'un compteur de 300 ml dans lequel on utilise des gaz de coupage internes. Il avait tout d'abord utilise, comme gaz de coupage, un melange d'ethylene et d'argon avec un anneau d'anticoincidence . Mais pour les taux de comptage faibles, les caracteristiques du palier, avec un montage en anticoincidence, n'etaient pas satisfaisantes en raison de l'insuffisance du coupage, et l'auteur a cherche un melange plus efficace. Il analyse la cause de la pente du palier de la courbe du bruit de fond et enumere les proprietes que devrait presenter un gaz de coupage efficace pour le comptage de l'hydrogene. Il donne ensuite les resultats obtenus, au point de vue des caracteristiques du comptage de l'hydrogene, avec les substances de coupage suivantes : benzene, bromure d'ethyle, ether ethylique, isopropylamine, hexane, ethylamine et isoprene. Avec l'ethylamine et l'ether ethylique, les caracteristiques de coupage

  17. Geiger-mode APD camera system for single-photon 3D LADAR imaging

    Science.gov (United States)

    Entwistle, Mark; Itzler, Mark A.; Chen, Jim; Owens, Mark; Patel, Ketan; Jiang, Xudong; Slomkowski, Krystyna; Rangwala, Sabbir

    2012-06-01

    The unparalleled sensitivity of 3D LADAR imaging sensors based on single photon detection provides substantial benefits for imaging at long stand-off distances and minimizing laser pulse energy requirements. To obtain 3D LADAR images with single photon sensitivity, we have demonstrated focal plane arrays (FPAs) based on InGaAsP Geiger-mode avalanche photodiodes (GmAPDs) optimized for use at either 1.06 μm or 1.55 μm. These state-of-the-art FPAs exhibit excellent pixel-level performance and the capability for 100% pixel yield on a 32 x 32 format. To realize the full potential of these FPAs, we have recently developed an integrated camera system providing turnkey operation based on FPGA control. This system implementation enables the extremely high frame-rate capability of the GmAPD FPA, and frame rates in excess of 250 kHz (for 0.4 μs range gates) can be accommodated using an industry-standard CameraLink interface in full configuration. Real-time data streaming for continuous acquisition of 2 μs range gate point cloud data with 13-bit time-stamp resolution at 186 kHz frame rates has been established using multiple solid-state storage drives. Range gate durations spanning 4 ns to 10 μs provide broad operational flexibility. The camera also provides real-time signal processing in the form of multi-frame gray-scale contrast images and single-frame time-stamp histograms, and automated bias control has been implemented to maintain a constant photon detection efficiency in the presence of ambient temperature changes. A comprehensive graphical user interface has been developed to provide complete camera control using a simple serial command set, and this command set supports highly flexible end-user customization.

  18. Design of a decade scaler prototype

    International Nuclear Information System (INIS)

    Rill Isaris; Widodo Priyodiprojo.

    1976-01-01

    A prototype of a simple decade scaler made of devices and components available in the local market, is described. The constituents of the system, consisting of an amplifier, pulse shaper, counting system, low voltage and high voltage supply, are also described. The number of pulses counted are indicated on six digits, varying to a maximum of 999999 counts, using LED device. This apparatus may be interconnected with scintillation and Geiger Muller detectors. (author)

  19. Retrotransposons Are the Major Contributors to the Expansion of the Drosophila ananassae Muller F Element.

    Science.gov (United States)

    Leung, Wilson; Shaffer, Christopher D; Chen, Elizabeth J; Quisenberry, Thomas J; Ko, Kevin; Braverman, John M; Giarla, Thomas C; Mortimer, Nathan T; Reed, Laura K; Smith, Sheryl T; Robic, Srebrenka; McCartha, Shannon R; Perry, Danielle R; Prescod, Lindsay M; Sheppard, Zenyth A; Saville, Ken J; McClish, Allison; Morlock, Emily A; Sochor, Victoria R; Stanton, Brittney; Veysey-White, Isaac C; Revie, Dennis; Jimenez, Luis A; Palomino, Jennifer J; Patao, Melissa D; Patao, Shane M; Himelblau, Edward T; Campbell, Jaclyn D; Hertz, Alexandra L; McEvilly, Maddison F; Wagner, Allison R; Youngblom, James; Bedi, Baljit; Bettincourt, Jeffery; Duso, Erin; Her, Maiye; Hilton, William; House, Samantha; Karimi, Masud; Kumimoto, Kevin; Lee, Rebekah; Lopez, Darryl; Odisho, George; Prasad, Ricky; Robbins, Holly Lyn; Sandhu, Tanveer; Selfridge, Tracy; Tsukashima, Kara; Yosif, Hani; Kokan, Nighat P; Britt, Latia; Zoellner, Alycia; Spana, Eric P; Chlebina, Ben T; Chong, Insun; Friedman, Harrison; Mammo, Danny A; Ng, Chun L; Nikam, Vinayak S; Schwartz, Nicholas U; Xu, Thomas Q; Burg, Martin G; Batten, Spencer M; Corbeill, Lindsay M; Enoch, Erica; Ensign, Jesse J; Franks, Mary E; Haiker, Breanna; Ingles, Judith A; Kirkland, Lyndsay D; Lorenz-Guertin, Joshua M; Matthews, Jordan; Mittig, Cody M; Monsma, Nicholaus; Olson, Katherine J; Perez-Aragon, Guillermo; Ramic, Alen; Ramirez, Jordan R; Scheiber, Christopher; Schneider, Patrick A; Schultz, Devon E; Simon, Matthew; Spencer, Eric; Wernette, Adam C; Wykle, Maxine E; Zavala-Arellano, Elizabeth; McDonald, Mitchell J; Ostby, Kristine; Wendland, Peter; DiAngelo, Justin R; Ceasrine, Alexis M; Cox, Amanda H; Docherty, James E B; Gingras, Robert M; Grieb, Stephanie M; Pavia, Michael J; Personius, Casey L; Polak, Grzegorz L; Beach, Dale L; Cerritos, Heaven L; Horansky, Edward A; Sharif, Karim A; Moran, Ryan; Parrish, Susan; Bickford, Kirsten; Bland, Jennifer; Broussard, Juliana; Campbell, Kerry; Deibel, Katelynn E; Forka, Richard; Lemke, Monika C; Nelson, Marlee B; O'Keeffe, Catherine; Ramey, S Mariel; Schmidt, Luke; Villegas, Paola; Jones, Christopher J; Christ, Stephanie L; Mamari, Sami; Rinaldi, Adam S; Stity, Ghazal; Hark, Amy T; Scheuerman, Mark; Silver Key, S Catherine; McRae, Briana D; Haberman, Adam S; Asinof, Sam; Carrington, Harriette; Drumm, Kelly; Embry, Terrance; McGuire, Richard; Miller-Foreman, Drew; Rosen, Stella; Safa, Nadia; Schultz, Darrin; Segal, Matt; Shevin, Yakov; Svoronos, Petros; Vuong, Tam; Skuse, Gary; Paetkau, Don W; Bridgman, Rachael K; Brown, Charlotte M; Carroll, Alicia R; Gifford, Francesca M; Gillespie, Julie Beth; Herman, Susan E; Holtcamp, Krystal L; Host, Misha A; Hussey, Gabrielle; Kramer, Danielle M; Lawrence, Joan Q; Martin, Madeline M; Niemiec, Ellen N; O'Reilly, Ashleigh P; Pahl, Olivia A; Quintana, Guadalupe; Rettie, Elizabeth A S; Richardson, Torie L; Rodriguez, Arianne E; Rodriguez, Mona O; Schiraldi, Laura; Smith, Joanna J; Sugrue, Kelsey F; Suriano, Lindsey J; Takach, Kaitlyn E; Vasquez, Arielle M; Velez, Ximena; Villafuerte, Elizabeth J; Vives, Laura T; Zellmer, Victoria R; Hauke, Jeanette; Hauser, Charles R; Barker, Karolyn; Cannon, Laurie; Parsamian, Perouza; Parsons, Samantha; Wichman, Zachariah; Bazinet, Christopher W; Johnson, Diana E; Bangura, Abubakarr; Black, Jordan A; Chevee, Victoria; Einsteen, Sarah A; Hilton, Sarah K; Kollmer, Max; Nadendla, Rahul; Stamm, Joyce; Fafara-Thompson, Antoinette E; Gygi, Amber M; Ogawa, Emmy E; Van Camp, Matt; Kocsisova, Zuzana; Leatherman, Judith L; Modahl, Cassie M; Rubin, Michael R; Apiz-Saab, Susana S; Arias-Mejias, Suzette M; Carrion-Ortiz, Carlos F; Claudio-Vazquez, Patricia N; Espada-Green, Debbie M; Feliciano-Camacho, Marium; Gonzalez-Bonilla, Karina M; Taboas-Arroyo, Mariela; Vargas-Franco, Dorianmarie; Montañez-Gonzalez, Raquel; Perez-Otero, Joseph; Rivera-Burgos, Myrielis; Rivera-Rosario, Francisco J; Eisler, Heather L; Alexander, Jackie; Begley, Samatha K; Gabbard, Deana; Allen, Robert J; Aung, Wint Yan; Barshop, William D; Boozalis, Amanda; Chu, Vanessa P; Davis, Jeremy S; Duggal, Ryan N; Franklin, Robert; Gavinski, Katherine; Gebreyesus, Heran; Gong, Henry Z; Greenstein, Rachel A; Guo, Averill D; Hanson, Casey; Homa, Kaitlin E; Hsu, Simon C; Huang, Yi; Huo, Lucy; Jacobs, Sarah; Jia, Sasha; Jung, Kyle L; Wai-Chee Kong, Sarah; Kroll, Matthew R; Lee, Brandon M; Lee, Paul F; Levine, Kevin M; Li, Amy S; Liu, Chengyu; Liu, Max Mian; Lousararian, Adam P; Lowery, Peter B; Mallya, Allyson P; Marcus, Joseph E; Ng, Patrick C; Nguyen, Hien P; Patel, Ruchik; Precht, Hashini; Rastogi, Suchita; Sarezky, Jonathan M; Schefkind, Adam; Schultz, Michael B; Shen, Delia; Skorupa, Tara; Spies, Nicholas C; Stancu, Gabriel; Vivian Tsang, Hiu Man; Turski, Alice L; Venkat, Rohit; Waldman, Leah E; Wang, Kaidi; Wang, Tracy; Wei, Jeffrey W; Wu, Dennis Y; Xiong, David D; Yu, Jack; Zhou, Karen; McNeil, Gerard P; Fernandez, Robert W; Menzies, Patrick Gomez; Gu, Tingting; Buhler, Jeremy; Mardis, Elaine R; Elgin, Sarah C R

    2017-08-07

    The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in Drosophila melanogaster , but it is substantially larger (>18.7 Mb) in D. ananassae To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors to this expansion (78.6%), while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%). Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes ( e.g. , larger coding spans, larger introns, more coding exons, and lower codon bias), but these differences are exaggerated in D. ananassae Compared to D. melanogaster , the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5' ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2), while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains. Copyright © 2017 Leung et al.

  20. Retrotransposons Are the Major Contributors to the Expansion of the Drosophila ananassae Muller F Element

    Directory of Open Access Journals (Sweden)

    Wilson Leung

    2017-08-01

    Full Text Available The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (>18.7 Mb in D. ananassae. To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons are major contributors to this expansion (78.6%, while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%. Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes (e.g., larger coding spans, larger introns, more coding exons, and lower codon bias, but these differences are exaggerated in D. ananassae. Compared to D. melanogaster, the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5′ ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2, while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains.

  1. Retrotransposons Are the Major Contributors to the Expansion of the Drosophila ananassae Muller F Element

    Science.gov (United States)

    Shaffer, Christopher D.; Chen, Elizabeth J.; Quisenberry, Thomas J.; Ko, Kevin; Braverman, John M.; Giarla, Thomas C.; Mortimer, Nathan T.; Reed, Laura K.; Smith, Sheryl T.; Robic, Srebrenka; McCartha, Shannon R.; Perry, Danielle R.; Prescod, Lindsay M.; Sheppard, Zenyth A.; Saville, Ken J.; McClish, Allison; Morlock, Emily A.; Sochor, Victoria R.; Stanton, Brittney; Veysey-White, Isaac C.; Revie, Dennis; Jimenez, Luis A.; Palomino, Jennifer J.; Patao, Melissa D.; Patao, Shane M.; Himelblau, Edward T.; Campbell, Jaclyn D.; Hertz, Alexandra L.; McEvilly, Maddison F.; Wagner, Allison R.; Youngblom, James; Bedi, Baljit; Bettincourt, Jeffery; Duso, Erin; Her, Maiye; Hilton, William; House, Samantha; Karimi, Masud; Kumimoto, Kevin; Lee, Rebekah; Lopez, Darryl; Odisho, George; Prasad, Ricky; Robbins, Holly Lyn; Sandhu, Tanveer; Selfridge, Tracy; Tsukashima, Kara; Yosif, Hani; Kokan, Nighat P.; Britt, Latia; Zoellner, Alycia; Spana, Eric P.; Chlebina, Ben T.; Chong, Insun; Friedman, Harrison; Mammo, Danny A.; Ng, Chun L.; Nikam, Vinayak S.; Schwartz, Nicholas U.; Xu, Thomas Q.; Burg, Martin G.; Batten, Spencer M.; Corbeill, Lindsay M.; Enoch, Erica; Ensign, Jesse J.; Franks, Mary E.; Haiker, Breanna; Ingles, Judith A.; Kirkland, Lyndsay D.; Lorenz-Guertin, Joshua M.; Matthews, Jordan; Mittig, Cody M.; Monsma, Nicholaus; Olson, Katherine J.; Perez-Aragon, Guillermo; Ramic, Alen; Ramirez, Jordan R.; Scheiber, Christopher; Schneider, Patrick A.; Schultz, Devon E.; Simon, Matthew; Spencer, Eric; Wernette, Adam C.; Wykle, Maxine E.; Zavala-Arellano, Elizabeth; McDonald, Mitchell J.; Ostby, Kristine; Wendland, Peter; DiAngelo, Justin R.; Ceasrine, Alexis M.; Cox, Amanda H.; Docherty, James E.B.; Gingras, Robert M.; Grieb, Stephanie M.; Pavia, Michael J.; Personius, Casey L.; Polak, Grzegorz L.; Beach, Dale L.; Cerritos, Heaven L.; Horansky, Edward A.; Sharif, Karim A.; Moran, Ryan; Parrish, Susan; Bickford, Kirsten; Bland, Jennifer; Broussard, Juliana; Campbell, Kerry; Deibel, Katelynn E.; Forka, Richard; Lemke, Monika C.; Nelson, Marlee B.; O'Keeffe, Catherine; Ramey, S. Mariel; Schmidt, Luke; Villegas, Paola; Jones, Christopher J.; Christ, Stephanie L.; Mamari, Sami; Rinaldi, Adam S.; Stity, Ghazal; Hark, Amy T.; Scheuerman, Mark; Silver Key, S. Catherine; McRae, Briana D.; Haberman, Adam S.; Asinof, Sam; Carrington, Harriette; Drumm, Kelly; Embry, Terrance; McGuire, Richard; Miller-Foreman, Drew; Rosen, Stella; Safa, Nadia; Schultz, Darrin; Segal, Matt; Shevin, Yakov; Svoronos, Petros; Vuong, Tam; Skuse, Gary; Paetkau, Don W.; Bridgman, Rachael K.; Brown, Charlotte M.; Carroll, Alicia R.; Gifford, Francesca M.; Gillespie, Julie Beth; Herman, Susan E.; Holtcamp, Krystal L.; Host, Misha A.; Hussey, Gabrielle; Kramer, Danielle M.; Lawrence, Joan Q.; Martin, Madeline M.; Niemiec, Ellen N.; O'Reilly, Ashleigh P.; Pahl, Olivia A.; Quintana, Guadalupe; Rettie, Elizabeth A.S.; Richardson, Torie L.; Rodriguez, Arianne E.; Rodriguez, Mona O.; Schiraldi, Laura; Smith, Joanna J.; Sugrue, Kelsey F.; Suriano, Lindsey J.; Takach, Kaitlyn E.; Vasquez, Arielle M.; Velez, Ximena; Villafuerte, Elizabeth J.; Vives, Laura T.; Zellmer, Victoria R.; Hauke, Jeanette; Hauser, Charles R.; Barker, Karolyn; Cannon, Laurie; Parsamian, Perouza; Parsons, Samantha; Wichman, Zachariah; Bazinet, Christopher W.; Johnson, Diana E.; Bangura, Abubakarr; Black, Jordan A.; Chevee, Victoria; Einsteen, Sarah A.; Hilton, Sarah K.; Kollmer, Max; Nadendla, Rahul; Stamm, Joyce; Fafara-Thompson, Antoinette E.; Gygi, Amber M.; Ogawa, Emmy E.; Van Camp, Matt; Kocsisova, Zuzana; Leatherman, Judith L.; Modahl, Cassie M.; Rubin, Michael R.; Apiz-Saab, Susana S.; Arias-Mejias, Suzette M.; Carrion-Ortiz, Carlos F.; Claudio-Vazquez, Patricia N.; Espada-Green, Debbie M.; Feliciano-Camacho, Marium; Gonzalez-Bonilla, Karina M.; Taboas-Arroyo, Mariela; Vargas-Franco, Dorianmarie; Montañez-Gonzalez, Raquel; Perez-Otero, Joseph; Rivera-Burgos, Myrielis; Rivera-Rosario, Francisco J.; Eisler, Heather L.; Alexander, Jackie; Begley, Samatha K.; Gabbard, Deana; Allen, Robert J.; Aung, Wint Yan; Barshop, William D.; Boozalis, Amanda; Chu, Vanessa P.; Davis, Jeremy S.; Duggal, Ryan N.; Franklin, Robert; Gavinski, Katherine; Gebreyesus, Heran; Gong, Henry Z.; Greenstein, Rachel A.; Guo, Averill D.; Hanson, Casey; Homa, Kaitlin E.; Hsu, Simon C.; Huang, Yi; Huo, Lucy; Jacobs, Sarah; Jia, Sasha; Jung, Kyle L.; Wai-Chee Kong, Sarah; Kroll, Matthew R.; Lee, Brandon M.; Lee, Paul F.; Levine, Kevin M.; Li, Amy S.; Liu, Chengyu; Liu, Max Mian; Lousararian, Adam P.; Lowery, Peter B.; Mallya, Allyson P.; Marcus, Joseph E.; Ng, Patrick C.; Nguyen, Hien P.; Patel, Ruchik; Precht, Hashini; Rastogi, Suchita; Sarezky, Jonathan M.; Schefkind, Adam; Schultz, Michael B.; Shen, Delia; Skorupa, Tara; Spies, Nicholas C.; Stancu, Gabriel; Vivian Tsang, Hiu Man; Turski, Alice L.; Venkat, Rohit; Waldman, Leah E.; Wang, Kaidi; Wang, Tracy; Wei, Jeffrey W.; Wu, Dennis Y.; Xiong, David D.; Yu, Jack; Zhou, Karen; McNeil, Gerard P.; Fernandez, Robert W.; Menzies, Patrick Gomez; Gu, Tingting; Buhler, Jeremy; Mardis, Elaine R.; Elgin, Sarah C.R.

    2017-01-01

    The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (>18.7 Mb) in D. ananassae. To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors to this expansion (78.6%), while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%). Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes (e.g., larger coding spans, larger introns, more coding exons, and lower codon bias), but these differences are exaggerated in D. ananassae. Compared to D. melanogaster, the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5′ ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2), while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains. PMID:28667019

  2. Cytogenetic mapping of the Muller F element genes in Drosophila willistoni group.

    Science.gov (United States)

    Pita, Sebastián; Panzera, Yanina; Lúcia da Silva Valente, Vera; de Melo, Zilpa das Graças Silva; Garcia, Carolina; Garcia, Ana Cristina Lauer; Montes, Martín Alejandro; Rohde, Claudia

    2014-10-01

    Comparative genomics in Drosophila began in 1940, when Muller stated that the ancestral haploid karyotype of this genus is constituted by five acrocentric chromosomes and one dot chromosome, named A to F elements. In some species of the willistoni group such as Drosophila willistoni and D. insularis, the F element, instead of a dot chromosome, has been incorporated into the E element, forming chromosome III (E + F fusion). The aim of this study was to investigate the scope of the E + F fusion in the willistoni group, evaluating six other species. Fluorescent in situ hybridization was used to locate two genes of the F element previously studied-cubitus interruptus (ci) and eyeless (ey)-in species of the willistoni and bocainensis subgroups. Moreover, polytene chromosome photomaps corresponding to the F element (basal portion of chromosome III) were constructed for each species studied. In D. willistoni, D. paulistorum and D. equinoxialis, the ci gene was located in subSectction 78B and the ey gene in 78C. In D. tropicalis, ci was located in subSection 76B and ey in 76C. In species of the bocainensis subgroup, ci and ey were localized, respectively, at subsections 76B and 76C in D. nebulosa and D. capricorni, and 76A and 76C in D. fumipennis. Despite the differences in the subsection numbers, all species showed the same position for ci and ey. The results confirm the synteny of E + F fusion in willistoni and bocainensis subgroups, and allow estimating the occurrence of this event at 15 Mya, at least.

  3. Categorical counting.

    Science.gov (United States)

    Fetterman, J Gregor; Killeen, P Richard

    2010-09-01

    Pigeons pecked on three keys, responses to one of which could be reinforced after a few pecks, to a second key after a somewhat larger number of pecks, and to a third key after the maximum pecking requirement. The values of the pecking requirements and the proportion of trials ending with reinforcement were varied. Transits among the keys were an orderly function of peck number, and showed approximately proportional changes with changes in the pecking requirements, consistent with Weber's law. Standard deviations of the switch points between successive keys increased more slowly within a condition than across conditions. Changes in reinforcement probability produced changes in the location of the psychometric functions that were consistent with models of timing. Analyses of the number of pecks emitted and the duration of the pecking sequences demonstrated that peck number was the primary determinant of choice, but that passage of time also played some role. We capture the basic results with a standard model of counting, which we qualify to account for the secondary experiments. Copyright 2010 Elsevier B.V. All rights reserved.

  4. A novel camera type for very high energy gamma-ray astronomy based on Geiger-mode avalanche photodiodes

    International Nuclear Information System (INIS)

    Anderhub, H; Biland, A; Boller, A; Braun, I; Commichau, S; Commichau, V; Dorner, D; Gendotti, A; Grimm, O; Gunten, H von; Hildebrand, D; Horisberger, U; Kraehenbuehl, T; Kranich, D; Lorenz, E; Lustermann, W; Backes, M; Neise, D; Bretz, T; Mannheim, K

    2009-01-01

    Geiger-mode avalanche photodiodes (G-APD) are promising new sensors for light detection in atmospheric Cherenkov telescopes. In this paper, the design and commissioning of a 36-pixel G-APD prototype camera is presented. The data acquisition is based on the Domino Ring Sampling (DRS2) chip. A sub-nanosecond time resolution has been achieved. Cosmic-ray induced air showers have been recorded using an imaging mirror setup, in a self-triggered mode. This is the first time that such measurements have been carried out with a complete G-APD camera.

  5. Das Thema “Altern” in Arno Geigers Roman «Alles über Sally»

    Directory of Open Access Journals (Sweden)

    Meike Dackweiler

    2013-11-01

    Full Text Available Alles über Sally (All about Sally is the fifth novel of the successful Austrian author Arno Geiger. While it was both praised and criticized for being a contemporary adaption of the adultery novel, little importance was attached to the theme of ageing, which pervades the whole novel. Moreover, adulterous female characters over fifty are rare in contemporary German literature. Given these premises, this essay examines the composition of the ageing characters in the novel and provides a discussion of the social construction of images of ageing.

  6. [Corrected count].

    Science.gov (United States)

    1991-11-27

    The data of the 1991 census indicated that the population count of Brazil fell short of a former estimate by 3 million people. The population reached 150 million people with an annual increase of 2%, while projections in the previous decade expected an increase of 2.48% to 153 million people. This reduction indicates more widespread use of family planning (FP) and control of fertility among families of lower social status as more information is being provided to them. However, the Ministry of Health ordered an investigation of foreign family planning organizations because it was suspected that women were forced to undergo tubal ligation during vaccination campaigns. A strange alliance of left wing politicians and the Roman Catholic Church alleges a conspiracy of international FP organizations receiving foreign funds. The FP strategies of Bemfam and Pro-Pater offer women who have little alternative the opportunity to undergo tubal ligation or to receive oral contraceptives to control fertility. The ongoing government program of distributing booklets on FP is feeble and is not backed up by an education campaign. Charges of foreign interference are leveled while the government hypocritically ignores the grave problem of 4 million abortions a year. The population is expected to continue to grow until the year 2040 and then to stabilize at a low growth rate of .4%. In 1980, the number of children per woman was 4.4 whereas the 1991 census figures indicate this has dropped to 3.5. The excess population is associated with poverty and a forsaken caste in the interior. The population actually has decreased in the interior and in cities with 15,000 people. The phenomenon of the drop of fertility associated with rural exodus is contrasted with cities and villages where the population is 20% less than expected.

  7. High-Speed Soft-Decision Decoding of Two Reed-Muller Codes

    Science.gov (United States)

    Lin, Shu; Uehara, Gregory T.

    1996-01-01

    In his research, we have proposed the (64, 40, 8) subcode of the third-order Reed-Muller (RM) code to NASA for high-speed satellite communications. This RM subcode can be used either alone or as an inner code of a concatenated coding system with the NASA standard (255, 233, 33) Reed-Solomon (RS) code as the outer code to achieve high performance (or low bit-error rate) with reduced decoding complexity. It can also be used as a component code in a multilevel bandwidth efficient coded modulation system to achieve reliable bandwidth efficient data transmission. This report will summarize the key progress we have made toward achieving our eventual goal of implementing a decoder system based upon this code. In the first phase of study, we investigated the complexities of various sectionalized trellis diagrams for the proposed (64, 40, 8) RNI subcode. We found a specific 8-trellis diagram for this code which requires the least decoding complexity with a high possibility of achieving a decoding speed of 600 M bits per second (Mbps). The combination of a large number of states and a hi ch data rate will be made possible due to the utilization of a high degree of parallelism throughout the architecture. This trellis diagram will be presented and briefly described. In the second phase of study which was carried out through the past year, we investigated circuit architectures to determine the feasibility of VLSI implementation of a high-speed Viterbi decoder based on this 8-section trellis diagram. We began to examine specific design and implementation approaches to implement a fully custom integrated circuit (IC) which will be a key building block for a decoder system implementation. The key results will be presented in this report. This report will be divided into three primary sections. First, we will briefly describe the system block diagram in which the proposed decoder is assumed to be operating and present some of the key architectural approaches being used to

  8. on the Population Growth of the Cladoceran Ceriodaphnia quadrangula (O. F. Muller, 1785.

    Directory of Open Access Journals (Sweden)

    Sevgi Savaş

    2015-12-01

    Full Text Available Cladoceran Ceriodaphnia quadrangula (O.F. Muller, 1785’nın populasyon artışı üzerine sıcaklık ve besin (Scenedesmus acuminatus (von Lagerheim R. H. Chodat yoğunluğunun etkisi. Bu çalışmada, Ceriodaphnia quadrangula’nın populasyon artışı üzerine sıcaklık (20, 25 ve 30 ºC ve farklı besin (Scenedesmus acuminatus yoğunluğunun (15,30,45, 60 ve75x104 h/ml etkisi incelenmiştir. Deneme 16 aydınlık:8 saat karanlık ışık uygulamasında gerçekleştirilmiştir. Deneme başında, farklı besin yoğunlukları içeren her bir tüpe 1 adet 24 saatten genç birey konulmuş, birey sayısı ve büyüme hızı 25 gün süre ile belirlenmiştir. En yüksek birey sayısı (21,433±0,750 birey/ml ve büyüme hızı (0,240±0,004 25 ºC’de 45x104 h/ml’de belirlenmiştir. Besin yoğunluğunun artması, Ceriodaphnia quadrangula’nın birey sayısı ve büyüme hızını arttırmıştır. Farklı besin yoğunluklarının birey sayısına etkisi istatistiki olarak önemli (P0,05 olduğu bulunmuştur

  9. Studies on the Edible Terrestrial Snails Helix aspersa Muller Food Conversion Ratio in a Confined Microclimate System

    Directory of Open Access Journals (Sweden)

    Adrian Toader-Williams

    2010-05-01

    Full Text Available Terrestrial edible snail breeding is an agricultural activity that finds itself at pioneering stage in Romania. One of the species used in snail farming is Helix aspersa Muller. In order to accelerate their growth, farmers feed the snails with pumpkins as well as concentrated forage consisting of mix of flours to which calcium carbonate is added in order to supplement snails need for shell’s development. In a controlled microclimate environment we measured the average growth of six weeks old Helix aspersa Muller snails placed in four different plastic enclosures. The consumption of different type of foods within 24 hours period was measured. The wheat (60%, corn flour (20% and calcium carbonate (20% mix had a superior food conversion ratio (FCR of 4.80, whereas the second FCR registered 6.04 in the case of 53% pumpkin and 47% flour mix served in the same time followed by the pure fresh vegetable mix accounting for a FCR of 8.00 and by 19.02 when only the pumpkin has been administrated as meal. During the experiments the snails did not have access to soil, being known that soil is an integral part of their diet.

  10. Multiple-Event, Single-Photon Counting Imaging Sensor

    Science.gov (United States)

    Zheng, Xinyu; Cunningham, Thomas J.; Sun, Chao; Wang, Kang L.

    2011-01-01

    The single-photon counting imaging sensor is typically an array of silicon Geiger-mode avalanche photodiodes that are monolithically integrated with CMOS (complementary metal oxide semiconductor) readout, signal processing, and addressing circuits located in each pixel and the peripheral area of the chip. The major problem is its single-event method for photon count number registration. A single-event single-photon counting imaging array only allows registration of up to one photon count in each of its pixels during a frame time, i.e., the interval between two successive pixel reset operations. Since the frame time can t be too short, this will lead to very low dynamic range and make the sensor merely useful for very low flux environments. The second problem of the prior technique is a limited fill factor resulting from consumption of chip area by the monolithically integrated CMOS readout in pixels. The resulting low photon collection efficiency will substantially ruin any benefit gained from the very sensitive single-photon counting detection. The single-photon counting imaging sensor developed in this work has a novel multiple-event architecture, which allows each of its pixels to register as more than one million (or more) photon-counting events during a frame time. Because of a consequently boosted dynamic range, the imaging array of the invention is capable of performing single-photon counting under ultra-low light through high-flux environments. On the other hand, since the multiple-event architecture is implemented in a hybrid structure, back-illumination and close-to-unity fill factor can be realized, and maximized quantum efficiency can also be achieved in the detector array.

  11. An application of high vacuum technique: fabrication of Geiger - Mueller counters and measurements of fallout radioactivity in Rio de Janeiro, Brazil, between 1950 and 1960

    International Nuclear Information System (INIS)

    Gross, B.

    1986-01-01

    The initial development of vacuum technology, in Brazil, is described. Special attention is given to the fabrication of Geiger-Mueller counters in the period between 1950-1960, abd the results obtained by its use in measurements of radioactivity produced by hydrogen weapons explosions in the atmosphere. (M.C.K.) [pt

  12. Geiger-Mode Avalanche Photodiode Arrays Integrated to All-Digital CMOS Circuits

    Science.gov (United States)

    2016-01-20

    important in photon‐starved applications, such as night vision or high‐temporal‐resolution imaging. Interest in such scenarios lead to Lincoln’s...information of interest. Lincoln Laboratory’s long-term vision is to merge these functions, so that the work of information extraction is carried...M. Boroson, David O. Caplan, Constantine J. Digenis, David R. Hearn, and Ryan C. Shoup, "Design of an Optical Photon Counting Array Receiver System

  13. Drosophila Muller F Elements Maintain a Distinct Set of Genomic Properties Over 40 Million Years of Evolution

    Science.gov (United States)

    Leung, Wilson; Shaffer, Christopher D.; Reed, Laura K.; Smith, Sheryl T.; Barshop, William; Dirkes, William; Dothager, Matthew; Lee, Paul; Wong, Jeannette; Xiong, David; Yuan, Han; Bedard, James E. J.; Machone, Joshua F.; Patterson, Seantay D.; Price, Amber L.; Turner, Bryce A.; Robic, Srebrenka; Luippold, Erin K.; McCartha, Shannon R.; Walji, Tezin A.; Walker, Chelsea A.; Saville, Kenneth; Abrams, Marita K.; Armstrong, Andrew R.; Armstrong, William; Bailey, Robert J.; Barberi, Chelsea R.; Beck, Lauren R.; Blaker, Amanda L.; Blunden, Christopher E.; Brand, Jordan P.; Brock, Ethan J.; Brooks, Dana W.; Brown, Marie; Butzler, Sarah C.; Clark, Eric M.; Clark, Nicole B.; Collins, Ashley A.; Cotteleer, Rebecca J.; Cullimore, Peterson R.; Dawson, Seth G.; Docking, Carter T.; Dorsett, Sasha L.; Dougherty, Grace A.; Downey, Kaitlyn A.; Drake, Andrew P.; Earl, Erica K.; Floyd, Trevor G.; Forsyth, Joshua D.; Foust, Jonathan D.; Franchi, Spencer L.; Geary, James F.; Hanson, Cynthia K.; Harding, Taylor S.; Harris, Cameron B.; Heckman, Jonathan M.; Holderness, Heather L.; Howey, Nicole A.; Jacobs, Dontae A.; Jewell, Elizabeth S.; Kaisler, Maria; Karaska, Elizabeth A.; Kehoe, James L.; Koaches, Hannah C.; Koehler, Jessica; Koenig, Dana; Kujawski, Alexander J.; Kus, Jordan E.; Lammers, Jennifer A.; Leads, Rachel R.; Leatherman, Emily C.; Lippert, Rachel N.; Messenger, Gregory S.; Morrow, Adam T.; Newcomb, Victoria; Plasman, Haley J.; Potocny, Stephanie J.; Powers, Michelle K.; Reem, Rachel M.; Rennhack, Jonathan P.; Reynolds, Katherine R.; Reynolds, Lyndsey A.; Rhee, Dong K.; Rivard, Allyson B.; Ronk, Adam J.; Rooney, Meghan B.; Rubin, Lainey S.; Salbert, Luke R.; Saluja, Rasleen K.; Schauder, Taylor; Schneiter, Allison R.; Schulz, Robert W.; Smith, Karl E.; Spencer, Sarah; Swanson, Bryant R.; Tache, Melissa A.; Tewilliager, Ashley A.; Tilot, Amanda K.; VanEck, Eve; Villerot, Matthew M.; Vylonis, Megan B.; Watson, David T.; Wurzler, Juliana A.; Wysocki, Lauren M.; Yalamanchili, Monica; Zaborowicz, Matthew A.; Emerson, Julia A.; Ortiz, Carlos; Deuschle, Frederic J.; DiLorenzo, Lauren A.; Goeller, Katie L.; Macchi, Christopher R.; Muller, Sarah E.; Pasierb, Brittany D.; Sable, Joseph E.; Tucci, Jessica M.; Tynon, Marykathryn; Dunbar, David A.; Beken, Levent H.; Conturso, Alaina C.; Danner, Benjamin L.; DeMichele, Gabriella A.; Gonzales, Justin A.; Hammond, Maureen S.; Kelley, Colleen V.; Kelly, Elisabeth A.; Kulich, Danielle; Mageeney, Catherine M.; McCabe, Nikie L.; Newman, Alyssa M.; Spaeder, Lindsay A.; Tumminello, Richard A.; Revie, Dennis; Benson, Jonathon M.; Cristostomo, Michael C.; DaSilva, Paolo A.; Harker, Katherine S.; Jarrell, Jenifer N.; Jimenez, Luis A.; Katz, Brandon M.; Kennedy, William R.; Kolibas, Kimberly S.; LeBlanc, Mark T.; Nguyen, Trung T.; Nicolas, Daniel S.; Patao, Melissa D.; Patao, Shane M.; Rupley, Bryan J.; Sessions, Bridget J.; Weaver, Jennifer A.; Goodman, Anya L.; Alvendia, Erica L.; Baldassari, Shana M.; Brown, Ashley S.; Chase, Ian O.; Chen, Maida; Chiang, Scott; Cromwell, Avery B.; Custer, Ashley F.; DiTommaso, Tia M.; El-Adaimi, Jad; Goscinski, Nora C.; Grove, Ryan A.; Gutierrez, Nestor; Harnoto, Raechel S.; Hedeen, Heather; Hong, Emily L.; Hopkins, Barbara L.; Huerta, Vilma F.; Khoshabian, Colin; LaForge, Kristin M.; Lee, Cassidy T.; Lewis, Benjamin M.; Lydon, Anniken M.; Maniaci, Brian J.; Mitchell, Ryan D.; Morlock, Elaine V.; Morris, William M.; Naik, Priyanka; Olson, Nicole C.; Osterloh, Jeannette M.; Perez, Marcos A.; Presley, Jonathan D.; Randazzo, Matt J.; Regan, Melanie K.; Rossi, Franca G.; Smith, Melanie A.; Soliterman, Eugenia A.; Sparks, Ciani J.; Tran, Danny L.; Wan, Tiffany; Welker, Anne A.; Wong, Jeremy N.; Sreenivasan, Aparna; Youngblom, Jim; Adams, Andrew; Alldredge, Justin; Bryant, Ashley; Carranza, David; Cifelli, Alyssa; Coulson, Kevin; Debow, Calise; Delacruz, Noelle; Emerson, Charlene; Farrar, Cassandra; Foret, Don; Garibay, Edgar; Gooch, John; Heslop, Michelle; Kaur, Sukhjit; Khan, Ambreen; Kim, Van; Lamb, Travis; Lindbeck, Peter; Lucas, Gabi; Macias, Elizabeth; Martiniuc, Daniela; Mayorga, Lissett; Medina, Joseph; Membreno, Nelson; Messiah, Shady; Neufeld, Lacey; Nguyen, San Francisco; Nichols, Zachary; Odisho, George; Peterson, Daymon; Rodela, Laura; Rodriguez, Priscilla; Rodriguez, Vanessa; Ruiz, Jorge; Sherrill, Will; Silva, Valeria; Sparks, Jeri; Statton, Geeta; Townsend, Ashley; Valdez, Isabel; Waters, Mary; Westphal, Kyle; Winkler, Stacey; Zumkehr, Joannee; DeJong, Randall J.; Hoogewerf, Arlene J.; Ackerman, Cheri M.; Armistead, Isaac O.; Baatenburg, Lara; Borr, Matthew J.; Brouwer, Lindsay K.; Burkhart, Brandon J.; Bushhouse, Kelsey T.; Cesko, Lejla; Choi, Tiffany Y. Y.; Cohen, Heather; Damsteegt, Amanda M.; Darusz, Jess M.; Dauphin, Cory M.; Davis, Yelena P.; Diekema, Emily J.; Drewry, Melissa; Eisen, Michelle E. M.; Faber, Hayley M.; Faber, Katherine J.; Feenstra, Elizabeth; Felzer-Kim, Isabella T.; Hammond, Brandy L.; Hendriksma, Jesse; Herrold, Milton R.; Hilbrands, Julia A.; Howell, Emily J.; Jelgerhuis, Sarah A.; Jelsema, Timothy R.; Johnson, Benjamin K.; Jones, Kelly K.; Kim, Anna; Kooienga, Ross D.; Menyes, Erika E.; Nollet, Eric A.; Plescher, Brittany E.; Rios, Lindsay; Rose, Jenny L.; Schepers, Allison J.; Scott, Geoff; Smith, Joshua R.; Sterling, Allison M.; Tenney, Jenna C.; Uitvlugt, Chris; VanDyken, Rachel E.; VanderVennen, Marielle; Vue, Samantha; Kokan, Nighat P.; Agbley, Kwabea; Boham, Sampson K.; Broomfield, Daniel; Chapman, Kayla; Dobbe, Ali; Dobbe, Ian; Harrington, William; Ibrahem, Marwan; Kennedy, Andre; Koplinsky, Chad A.; Kubricky, Cassandra; Ladzekpo, Danielle; Pattison, Claire; Ramirez, Roman E.; Wande, Lucia; Woehlke, Sarah; Wawersik, Matthew; Kiernan, Elizabeth; Thompson, Jeffrey S.; Banker, Roxanne; Bartling, Justina R.; Bhatiya, Chinmoy I.; Boudoures, Anna L.; Christiansen, Lena; Fosselman, Daniel S.; French, Kristin M.; Gill, Ishwar S.; Havill, Jessen T.; Johnson, Jaelyn L.; Keny, Lauren J.; Kerber, John M.; Klett, Bethany M.; Kufel, Christina N.; May, Francis J.; Mecoli, Jonathan P.; Merry, Callie R.; Meyer, Lauren R.; Miller, Emily G.; Mullen, Gregory J.; Palozola, Katherine C.; Pfeil, Jacob J.; Thomas, Jessica G.; Verbofsky, Evan M.; Spana, Eric P.; Agarwalla, Anant; Chapman, Julia; Chlebina, Ben; Chong, Insun; Falk, I.N.; Fitzgibbons, John D.; Friedman, Harrison; Ighile, Osagie; Kim, Andrew J.; Knouse, Kristin A.; Kung, Faith; Mammo, Danny; Ng, Chun Leung; Nikam, Vinayak S.; Norton, Diana; Pham, Philip; Polk, Jessica W.; Prasad, Shreya; Rankin, Helen; Ratliff, Camille D.; Scala, Victoria; Schwartz, Nicholas U.; Shuen, Jessica A.; Xu, Amy; Xu, Thomas Q.; Zhang, Yi; Rosenwald, Anne G.; Burg, Martin G.; Adams, Stephanie J.; Baker, Morgan; Botsford, Bobbi; Brinkley, Briana; Brown, Carter; Emiah, Shadie; Enoch, Erica; Gier, Chad; Greenwell, Alyson; Hoogenboom, Lindsay; Matthews, Jordan E.; McDonald, Mitchell; Mercer, Amanda; Monsma, Nicholaus; Ostby, Kristine; Ramic, Alen; Shallman, Devon; Simon, Matthew; Spencer, Eric; Tomkins, Trisha; Wendland, Pete; Wylie, Anna; Wolyniak, Michael J.; Robertson, Gregory M.; Smith, Samuel I.; DiAngelo, Justin R.; Sassu, Eric D.; Bhalla, Satish C.; Sharif, Karim A.; Choeying, Tenzin; Macias, Jason S.; Sanusi, Fareed; Torchon, Karvyn; Bednarski, April E.; Alvarez, Consuelo J.; Davis, Kristen C.; Dunham, Carrie A.; Grantham, Alaina J.; Hare, Amber N.; Schottler, Jennifer; Scott, Zackary W.; Kuleck, Gary A.; Yu, Nicole S.; Kaehler, Marian M.; Jipp, Jacob; Overvoorde, Paul J.; Shoop, Elizabeth; Cyrankowski, Olivia; Hoover, Betsy; Kusner, Matt; Lin, Devry; Martinov, Tijana; Misch, Jonathan; Salzman, Garrett; Schiedermayer, Holly; Snavely, Michael; Zarrasola, Stephanie; Parrish, Susan; Baker, Atlee; Beckett, Alissa; Belella, Carissa; Bryant, Julie; Conrad, Turner; Fearnow, Adam; Gomez, Carolina; Herbstsomer, Robert A.; Hirsch, Sarah; Johnson, Christen; Jones, Melissa; Kabaso, Rita; Lemmon, Eric; Vieira, Carolina Marques dos Santos; McFarland, Darryl; McLaughlin, Christopher; Morgan, Abbie; Musokotwane, Sepo; Neutzling, William; Nietmann, Jana; Paluskievicz, Christina; Penn, Jessica; Peoples, Emily; Pozmanter, Caitlin; Reed, Emily; Rigby, Nichole; Schmidt, Lasse; Shelton, Micah; Shuford, Rebecca; Tirasawasdichai, Tiara; Undem, Blair; Urick, Damian; Vondy, Kayla; Yarrington, Bryan; Eckdahl, Todd T.; Poet, Jeffrey L.; Allen, Alica B.; Anderson, John E.; Barnett, Jason M.; Baumgardner, Jordan S.; Brown, Adam D.; Carney, Jordan E.; Chavez, Ramiro A.; Christgen, Shelbi L.; Christie, Jordan S.; Clary, Andrea N.; Conn, Michel A.; Cooper, Kristen M.; Crowley, Matt J.; Crowley, Samuel T.; Doty, Jennifer S.; Dow, Brian A.; Edwards, Curtis R.; Elder, Darcie D.; Fanning, John P.; Janssen, Bridget M.; Lambright, Anthony K.; Lane, Curtiss E.; Limle, Austin B.; Mazur, Tammy; McCracken, Marly R.; McDonough, Alexa M.; Melton, Amy D.; Minnick, Phillip J.; Musick, Adam E.; Newhart, William H.; Noynaert, Joseph W.; Ogden, Bradley J.; Sandusky, Michael W.; Schmuecker, Samantha M.; Shipman, Anna L.; Smith, Anna L.; Thomsen, Kristen M.; Unzicker, Matthew R.; Vernon, William B.; Winn, Wesley W.; Woyski, Dustin S.; Zhu, Xiao; Du, Chunguang; Ament, Caitlin; Aso, Soham; Bisogno, Laura Simone; Caronna, Jason; Fefelova, Nadezhda; Lopez, Lenin; Malkowitz, Lorraine; Marra, Jonathan; Menillo, Daniella; Obiorah, Ifeanyi; Onsarigo, Eric Nyabeta; Primus, Shekerah; Soos, Mahdi; Tare, Archana; Zidan, Ameer; Jones, Christopher J.; Aronhalt, Todd; Bellush, James M.; Burke, Christa; DeFazio, Steve; Does, Benjamin R.; Johnson, Todd D.; Keysock, Nicholas; Knudsen, Nelson H.; Messler, James; Myirski, Kevin; Rekai, Jade Lea; Rempe, Ryan Michael; Salgado, Michael S.; Stagaard, Erica; Starcher, Justin R.; Waggoner, Andrew W.; Yemelyanova, Anastasia K.; Hark, Amy T.; Bertolet, Anne; Kuschner, Cyrus E.; Parry, Kesley; Quach, Michael; Shantzer, Lindsey; Shaw, Mary E.; Smith, Mary A.; Glenn, Omolara; Mason, Portia; Williams, Charlotte; Key, S. Catherine Silver; Henry, Tyneshia C. P.; Johnson, Ashlee G.; White, Jackie X.; Haberman, Adam; Asinof, Sam; Drumm, Kelly; Freeburg, Trip; Safa, Nadia; Schultz, Darrin; Shevin, Yakov; Svoronos, Petros; Vuong, Tam; Wellinghoff, Jules; Hoopes, Laura L. M.; Chau, Kim M.; Ward, Alyssa; Regisford, E. Gloria C.; Augustine, LaJerald; Davis-Reyes, Brionna; Echendu, Vivienne; Hales, Jasmine; Ibarra, Sharon; Johnson, Lauriaun; Ovu, Steven; Braverman, John M.; Bahr, Thomas J.; Caesar, Nicole M.; Campana, Christopher; Cassidy, Daniel W.; Cognetti, Peter A.; English, Johnathan D.; Fadus, Matthew C.; Fick, Cameron N.; Freda, Philip J.; Hennessy, Bryan M.; Hockenberger, Kelsey; Jones, Jennifer K.; King, Jessica E.; Knob, Christopher R.; Kraftmann, Karen J.; Li, Linghui; Lupey, Lena N.; Minniti, Carl J.; Minton, Thomas F.; Moran, Joseph V.; Mudumbi, Krishna; Nordman, Elizabeth C.; Puetz, William J.; Robinson, Lauren M.; Rose, Thomas J.; Sweeney, Edward P.; Timko, Ashley S.; Paetkau, Don W.; Eisler, Heather L.; Aldrup, Megan E.; Bodenberg, Jessica M.; Cole, Mara G.; Deranek, Kelly M.; DeShetler, Megan; Dowd, Rose M.; Eckardt, Alexandra K.; Ehret, Sharon C.; Fese, Jessica; Garrett, Amanda D.; Kammrath, Anna; Kappes, Michelle L.; Light, Morgan R.; Meier, Anne C.; O’Rouke, Allison; Perella, Mallory; Ramsey, Kimberley; Ramthun, Jennifer R.; Reilly, Mary T.; Robinett, Deirdre; Rossi, Nadine L.; Schueler, Mary Grace; Shoemaker, Emma; Starkey, Kristin M.; Vetor, Ashley; Vrable, Abby; Chandrasekaran, Vidya; Beck, Christopher; Hatfield, Kristen R.; Herrick, Douglas A.; Khoury, Christopher B.; Lea, Charlotte; Louie, Christopher A.; Lowell, Shannon M.; Reynolds, Thomas J.; Schibler, Jeanine; Scoma, Alexandra H.; Smith-Gee, Maxwell T.; Tuberty, Sarah; Smith, Christopher D.; Lopilato, Jane E.; Hauke, Jeanette; Roecklein-Canfield, Jennifer A.; Corrielus, Maureen; Gilman, Hannah; Intriago, Stephanie; Maffa, Amanda; Rauf, Sabya A.; Thistle, Katrina; Trieu, Melissa; Winters, Jenifer; Yang, Bib; Hauser, Charles R.; Abusheikh, Tariq; Ashrawi, Yara; Benitez, Pedro; Boudreaux, Lauren R.; Bourland, Megan; Chavez, Miranda; Cruz, Samantha; Elliott, GiNell; Farek, Jesse R.; Flohr, Sarah; Flores, Amanda H.; Friedrichs, Chelsey; Fusco, Zach; Goodwin, Zane; Helmreich, Eric; Kiley, John; Knepper, John Mark; Langner, Christine; Martinez, Megan; Mendoza, Carlos; Naik, Monal; Ochoa, Andrea; Ragland, Nicolas; Raimey, England; Rathore, Sunil; Reza, Evangelina; Sadovsky, Griffin; Seydoux, Marie-Isabelle B.; Smith, Jonathan E.; Unruh, Anna K.; Velasquez, Vicente; Wolski, Matthew W.; Gosser, Yuying; Govind, Shubha; Clarke-Medley, Nicole; Guadron, Leslie; Lau, Dawn; Lu, Alvin; Mazzeo, Cheryl; Meghdari, Mariam; Ng, Simon; Pamnani, Brad; Plante, Olivia; Shum, Yuki Kwan Wa; Song, Roy; Johnson, Diana E.; Abdelnabi, Mai; Archambault, Alexi; Chamma, Norma; Gaur, Shailly; Hammett, Deborah; Kandahari, Adrese; Khayrullina, Guzal; Kumar, Sonali; Lawrence, Samantha; Madden, Nigel; Mandelbaum, Max; Milnthorp, Heather; Mohini, Shiv; Patel, Roshni; Peacock, Sarah J.; Perling, Emily; Quintana, Amber; Rahimi, Michael; Ramirez, Kristen; Singhal, Rishi; Weeks, Corinne; Wong, Tiffany; Gillis, Aubree T.; Moore, Zachary D.; Savell, Christopher D.; Watson, Reece; Mel, Stephanie F.; Anilkumar, Arjun A.; Bilinski, Paul; Castillo, Rostislav; Closser, Michael; Cruz, Nathalia M.; Dai, Tiffany; Garbagnati, Giancarlo F.; Horton, Lanor S.; Kim, Dongyeon; Lau, Joyce H.; Liu, James Z.; Mach, Sandy D.; Phan, Thu A.; Ren, Yi; Stapleton, Kenneth E.; Strelitz, Jean M.; Sunjed, Ray; Stamm, Joyce; Anderson, Morgan C.; Bonifield, Bethany Grace; Coomes, Daniel; Dillman, Adam; Durchholz, Elaine J.; Fafara-Thompson, Antoinette E.; Gross, Meleah J.; Gygi, Amber M.; Jackson, Lesley E.; Johnson, Amy; Kocsisova, Zuzana; Manghelli, Joshua L.; McNeil, Kylie; Murillo, Michael; Naylor, Kierstin L.; Neely, Jessica; Ogawa, Emmy E.; Rich, Ashley; Rogers, Anna; Spencer, J. Devin; Stemler, Kristina M.; Throm, Allison A.; Van Camp, Matt; Weihbrecht, Katie; Wiles, T. Aaron; Williams, Mallory A.; Williams, Matthew; Zoll, Kyle; Bailey, Cheryl; Zhou, Leming; Balthaser, Darla M.; Bashiri, Azita; Bower, Mindy E.; Florian, Kayla A.; Ghavam, Nazanin; Greiner-Sosanko, Elizabeth S.; Karim, Helmet; Mullen, Victor W.; Pelchen, Carly E.; Yenerall, Paul M.; Zhang, Jiayu; Rubin, Michael R.; Arias-Mejias, Suzette M.; Bermudez-Capo, Armando G.; Bernal-Vega, Gabriela V.; Colon-Vazquez, Mariela; Flores-Vazquez, Arelys; Gines-Rosario, Mariela; Llavona-Cartagena, Ivan G.; Martinez-Rodriguez, Javier O.; Ortiz-Fuentes, Lionel; Perez-Colomba, Eliezer O.; Perez-Otero, Joseph; Rivera, Elisandra; Rodriguez-Giron, Luke J.; Santiago-Sanabria, Arnaldo J.; Senquiz-Gonzalez, Andrea M.; delValle, Frank R. 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    2015-01-01

    The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25–50%) than euchromatic reference regions (3–11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11–27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4–3.6 vs. 8.4–8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu. PMID:25740935

  14. Drosophila muller f elements maintain a distinct set of genomic properties over 40 million years of evolution.

    Science.gov (United States)

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Braverman, John M; Bahr, Thomas J; Caesar, Nicole M; Campana, Christopher; Cassidy, Daniel W; Cognetti, Peter A; English, Johnathan D; Fadus, Matthew C; Fick, Cameron N; Freda, Philip J; Hennessy, Bryan M; Hockenberger, Kelsey; Jones, Jennifer K; King, Jessica E; Knob, Christopher R; Kraftmann, Karen J; Li, Linghui; Lupey, Lena N; Minniti, Carl J; Minton, Thomas F; Moran, Joseph V; Mudumbi, Krishna; Nordman, Elizabeth C; Puetz, William J; Robinson, Lauren M; Rose, Thomas J; Sweeney, Edward P; Timko, Ashley S; Paetkau, Don W; Eisler, Heather L; Aldrup, Megan E; Bodenberg, Jessica M; Cole, Mara G; Deranek, Kelly M; DeShetler, Megan; Dowd, Rose M; Eckardt, Alexandra K; Ehret, Sharon C; Fese, Jessica; Garrett, Amanda D; Kammrath, Anna; Kappes, Michelle L; Light, Morgan R; Meier, Anne C; O'Rouke, Allison; Perella, Mallory; Ramsey, Kimberley; Ramthun, Jennifer R; Reilly, Mary T; Robinett, Deirdre; Rossi, Nadine L; Schueler, Mary Grace; Shoemaker, Emma; Starkey, Kristin M; Vetor, Ashley; Vrable, Abby; Chandrasekaran, Vidya; Beck, Christopher; Hatfield, Kristen R; Herrick, Douglas A; Khoury, Christopher B; Lea, Charlotte; Louie, Christopher A; Lowell, Shannon M; Reynolds, Thomas J; Schibler, Jeanine; Scoma, Alexandra H; Smith-Gee, Maxwell T; Tuberty, Sarah; Smith, Christopher D; Lopilato, Jane E; Hauke, Jeanette; Roecklein-Canfield, Jennifer A; Corrielus, Maureen; Gilman, Hannah; Intriago, Stephanie; Maffa, Amanda; Rauf, Sabya A; Thistle, Katrina; Trieu, Melissa; Winters, Jenifer; Yang, Bib; Hauser, Charles R; Abusheikh, Tariq; Ashrawi, Yara; Benitez, Pedro; Boudreaux, Lauren R; Bourland, Megan; Chavez, Miranda; Cruz, Samantha; Elliott, GiNell; Farek, Jesse R; Flohr, Sarah; Flores, Amanda H; Friedrichs, Chelsey; Fusco, Zach; Goodwin, Zane; Helmreich, Eric; Kiley, John; Knepper, John Mark; Langner, Christine; Martinez, Megan; Mendoza, Carlos; Naik, Monal; Ochoa, Andrea; Ragland, Nicolas; Raimey, England; Rathore, Sunil; Reza, Evangelina; Sadovsky, Griffin; Seydoux, Marie-Isabelle B; Smith, Jonathan E; Unruh, Anna K; Velasquez, Vicente; Wolski, Matthew W; Gosser, Yuying; Govind, Shubha; Clarke-Medley, Nicole; Guadron, Leslie; Lau, Dawn; Lu, Alvin; Mazzeo, Cheryl; Meghdari, Mariam; Ng, Simon; Pamnani, Brad; Plante, Olivia; Shum, Yuki Kwan Wa; Song, Roy; Johnson, Diana E; Abdelnabi, Mai; Archambault, Alexi; Chamma, Norma; Gaur, Shailly; Hammett, Deborah; Kandahari, Adrese; Khayrullina, Guzal; Kumar, Sonali; Lawrence, Samantha; Madden, Nigel; Mandelbaum, Max; Milnthorp, Heather; Mohini, Shiv; Patel, Roshni; Peacock, Sarah J; Perling, Emily; Quintana, Amber; Rahimi, Michael; Ramirez, Kristen; Singhal, Rishi; Weeks, Corinne; Wong, Tiffany; Gillis, Aubree T; Moore, Zachary D; Savell, Christopher D; Watson, Reece; Mel, Stephanie F; Anilkumar, Arjun A; Bilinski, Paul; Castillo, Rostislav; Closser, Michael; Cruz, Nathalia M; Dai, Tiffany; Garbagnati, Giancarlo F; Horton, Lanor S; Kim, Dongyeon; Lau, Joyce H; Liu, James Z; Mach, Sandy D; Phan, Thu A; Ren, Yi; Stapleton, Kenneth E; Strelitz, Jean M; Sunjed, Ray; Stamm, Joyce; Anderson, Morgan C; Bonifield, Bethany Grace; Coomes, Daniel; Dillman, Adam; Durchholz, Elaine J; Fafara-Thompson, Antoinette E; Gross, Meleah J; Gygi, Amber M; Jackson, Lesley E; Johnson, Amy; Kocsisova, Zuzana; Manghelli, Joshua L; McNeil, Kylie; Murillo, Michael; Naylor, Kierstin L; Neely, Jessica; Ogawa, Emmy E; Rich, Ashley; Rogers, Anna; Spencer, J Devin; Stemler, Kristina M; Throm, Allison A; Van Camp, Matt; Weihbrecht, Katie; Wiles, T Aaron; Williams, Mallory A; Williams, Matthew; Zoll, Kyle; Bailey, Cheryl; Zhou, Leming; Balthaser, Darla M; Bashiri, Azita; Bower, Mindy E; Florian, Kayla A; Ghavam, Nazanin; Greiner-Sosanko, Elizabeth S; Karim, Helmet; Mullen, Victor W; Pelchen, Carly E; Yenerall, Paul M; Zhang, Jiayu; Rubin, Michael R; Arias-Mejias, Suzette M; Bermudez-Capo, Armando G; Bernal-Vega, Gabriela V; Colon-Vazquez, Mariela; Flores-Vazquez, Arelys; Gines-Rosario, Mariela; Llavona-Cartagena, Ivan G; Martinez-Rodriguez, Javier O; Ortiz-Fuentes, Lionel; Perez-Colomba, Eliezer O; Perez-Otero, Joseph; Rivera, Elisandra; Rodriguez-Giron, Luke J; Santiago-Sanabria, Arnaldo J; Senquiz-Gonzalez, Andrea M; delValle, Frank R Soto; Vargas-Franco, Dorianmarie; Velázquez-Soto, Karla I; Zambrana-Burgos, Joan D; Martinez-Cruzado, Juan Carlos; Asencio-Zayas, Lillyann; Babilonia-Figueroa, Kevin; Beauchamp-Pérez, Francis D; Belén-Rodríguez, Juliana; Bracero-Quiñones, Luciann; Burgos-Bula, Andrea P; Collado-Méndez, Xavier A; Colón-Cruz, Luis R; Correa-Muller, Ana I; Crooke-Rosado, Jonathan L; Cruz-García, José M; Defendini-Ávila, Marianna; Delgado-Peraza, Francheska M; Feliciano-Cancela, Alex J; Gónzalez-Pérez, Valerie M; Guiblet, Wilfried; Heredia-Negrón, Aldo; Hernández-Muñiz, Jennifer; Irizarry-González, Lourdes N; Laboy-Corales, Ángel L; Llaurador-Caraballo, Gabriela A; Marín-Maldonado, Frances; Marrero-Llerena, Ulises; Martell-Martínez, Héctor A; Martínez-Traverso, Idaliz M; Medina-Ortega, Kiara N; Méndez-Castellanos, Sonya G; Menéndez-Serrano, Krizia C; Morales-Caraballo, Carol I; Ortiz-DeChoudens, Saryleine; Ortiz-Ortiz, Patricia; Pagán-Torres, Hendrick; Pérez-Afanador, Diana; Quintana-Torres, Enid M; Ramírez-Aponte, Edwin G; Riascos-Cuero, Carolina; Rivera-Llovet, Michelle S; Rivera-Pagán, Ingrid T; Rivera-Vicéns, Ramón E; Robles-Juarbe, Fabiola; Rodríguez-Bonilla, Lorraine; Rodríguez-Echevarría, Brian O; Rodríguez-García, Priscila M; Rodríguez-Laboy, Abneris E; Rodríguez-Santiago, Susana; Rojas-Vargas, Michael L; Rubio-Marrero, Eva N; Santiago-Colón, Albeliz; Santiago-Ortiz, Jorge L; Santos-Ramos, Carlos E; Serrano-González, Joseline; Tamayo-Figueroa, Alina M; Tascón-Peñaranda, Edna P; Torres-Castillo, José L; Valentín-Feliciano, Nelson A; Valentín-Feliciano, Yashira M; Vargas-Barreto, Nadyan M; Vélez-Vázquez, Miguel; Vilanova-Vélez, Luis R; Zambrana-Echevarría, Cristina; MacKinnon, Christy; Chung, Hui-Min; Kay, Chris; Pinto, Anthony; Kopp, Olga R; Burkhardt, Joshua; Harward, Chris; Allen, Robert; Bhat, Pavan; Chang, Jimmy Hsiang-Chun; Chen, York; Chesley, Christopher; Cohn, Dara; DuPuis, David; Fasano, Michael; Fazzio, Nicholas; Gavinski, Katherine; Gebreyesus, Heran; Giarla, Thomas; Gostelow, Marcus; Greenstein, Rachel; Gunasinghe, Hashini; Hanson, Casey; Hay, Amanda; He, Tao Jian; Homa, Katie; Howe, Ruth; Howenstein, Jeff; Huang, Henry; Khatri, Aaditya; Kim, Young Lu; Knowles, Olivia; Kong, Sarah; Krock, Rebecca; Kroll, Matt; Kuhn, Julia; Kwong, Matthew; Lee, Brandon; Lee, Ryan; Levine, Kevin; Li, Yedda; Liu, Bo; Liu, Lucy; Liu, Max; Lousararian, Adam; Ma, Jimmy; Mallya, Allyson; Manchee, Charlie; Marcus, Joseph; McDaniel, Stephen; Miller, Michelle L; Molleston, Jerome M; Diez, Cristina Montero; Ng, Patrick; Ngai, Natalie; Nguyen, Hien; Nylander, Andrew; Pollack, Jason; Rastogi, Suchita; Reddy, Himabindu; Regenold, Nathaniel; Sarezky, Jon; Schultz, Michael; Shim, Jien; Skorupa, Tara; Smith, Kenneth; Spencer, Sarah J; Srikanth, Priya; Stancu, Gabriel; Stein, Andrew P; Strother, Marshall; Sudmeier, Lisa; Sun, Mengyang; Sundaram, Varun; Tazudeen, Noor; Tseng, Alan; Tzeng, Albert; Venkat, Rohit; Venkataram, Sandeep; Waldman, Leah; Wang, Tracy; Yang, Hao; Yu, Jack Y; Zheng, Yin; Preuss, Mary L; Garcia, Angelica; Juergens, Matt; Morris, Robert W; Nagengast, Alexis A; Azarewicz, Julie; Carr, Thomas J; Chichearo, Nicole; Colgan, Mike; Donegan, Megan; Gardner, Bob; Kolba, Nik; Krumm, Janice L; Lytle, Stacey; MacMillian, Laurell; Miller, Mary; Montgomery, Andrew; Moretti, Alysha; Offenbacker, Brittney; Polen, Mike; Toth, John; Woytanowski, John; Kadlec, Lisa; Crawford, Justin; Spratt, Mary L; Adams, Ashley L; Barnard, Brianna K; Cheramie, Martin N; Eime, Anne M; Golden, Kathryn L; Hawkins, Allyson P; Hill, Jessica E; Kampmeier, Jessica A; Kern, Cody D; Magnuson, Emily E; Miller, Ashley R; Morrow, Cody M; Peairs, Julia C; Pickett, Gentry L; Popelka, Sarah A; Scott, Alexis J; Teepe, Emily J; TerMeer, Katie A; Watchinski, Carmen A; Watson, Lucas A; Weber, Rachel E; Woodard, Kate A; Barnard, Daron C; Appiah, Isaac; Giddens, Michelle M; McNeil, Gerard P; Adebayo, Adeola; Bagaeva, Kate; Chinwong, Justina; Dol, Chrystel; George, Eunice; Haltaufderhyde, Kirk; Haye, Joanna; Kaur, Manpreet; Semon, Max; Serjanov, Dmitri; Toorie, Anika; Wilson, Christopher; Riddle, Nicole C; Buhler, Jeremy; Mardis, Elaine R; Elgin, Sarah C R

    2015-03-04

    The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25-50%) than euchromatic reference regions (3-11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11-27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4-3.6 vs. 8.4-8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu. Copyright © 2015 Leung et al.

  15. Determining random counts in liquid scintillation counting

    International Nuclear Information System (INIS)

    Horrocks, D.L.

    1979-01-01

    During measurements involving coincidence counting techniques, errors can arise due to the detection of chance or random coincidences in the multiple detectors used. A method and the electronic circuits necessary are here described for eliminating this source of error in liquid scintillation detectors used in coincidence counting. (UK)

  16. HgCdTe APD-based linear-mode photon counting components and ladar receivers

    Science.gov (United States)

    Jack, Michael; Wehner, Justin; Edwards, John; Chapman, George; Hall, Donald N. B.; Jacobson, Shane M.

    2011-05-01

    Linear mode photon counting (LMPC) provides significant advantages in comparison with Geiger Mode (GM) Photon Counting including absence of after-pulsing, nanosecond pulse to pulse temporal resolution and robust operation in the present of high density obscurants or variable reflectivity objects. For this reason Raytheon has developed and previously reported on unique linear mode photon counting components and modules based on combining advanced APDs and advanced high gain circuits. By using HgCdTe APDs we enable Poisson number preserving photon counting. A metric of photon counting technology is dark count rate and detection probability. In this paper we report on a performance breakthrough resulting from improvement in design, process and readout operation enabling >10x reduction in dark counts rate to ~10,000 cps and >104x reduction in surface dark current enabling long 10 ms integration times. Our analysis of key dark current contributors suggest that substantial further reduction in DCR to ~ 1/sec or less can be achieved by optimizing wavelength, operating voltage and temperature.

  17. Clean Hands Count

    Medline Plus

    Full Text Available ... Like this video? Sign in to make your opinion count. Sign in 131 2 Don't like this video? Sign in to make your opinion count. Sign in 3 Loading... Loading... Transcript The ...

  18. The Big Pumpkin Count.

    Science.gov (United States)

    Coplestone-Loomis, Lenny

    1981-01-01

    Pumpkin seeds are counted after students convert pumpkins to jack-o-lanterns. Among the activities involved, pupils learn to count by 10s, make estimates, and to construct a visual representation of 1,000. (MP)

  19. Advance in radioactive decontamination

    International Nuclear Information System (INIS)

    Basteris M, J. A.; Farrera V, R.

    2010-09-01

    The objective of the present work was to determine if the application of the Na hypochlorite has some utility in the radioactive decontamination, in comparison with the water, detergent and alcohol. Several methods were compared for decontaminate the iodine 131 and technetium 99, the work table and the skin it was carried out an initial count with the Geiger Muller. Later on, in a single occasion, the areas were washed with abundant water, alcohol, clothes detergent and sodium hypochlorite (used commercially as domestic bleacher) without diluting. Observing that the percentage in the decrease of the counted radioactivity by the Geiger Muller, decreased in the following way: It was demonstrated that the Na hypochlorite presents the highest index of radioactive decontamination with 100% of effectiveness. The Na hypochlorite is an excellent substance that can be used with effectiveness and efficiency like decontamination element in the accident cases of radioactive contamination in the clinical laboratories of nuclear medicine. (Author)

  20. Advance in radioactive decontamination; Avances en descontaminacion radiactiva

    Energy Technology Data Exchange (ETDEWEB)

    Basteris M, J. A. [Universidad Autonoma de Yucatan, Facultad de Medicina, Departamento de Diagnostico por Laboratorio y Gabinete, Av. Cupules No. 232, Col. Garcia Gineres, 97070 Merida, Yucatan (Mexico); Farrera V, R., E-mail: basteris@prodigy.net.m [Hospital de Especialidades de la UMAE, Centro Medico Nacional Ignacio Garcia Tellez, Departamento de Medicina Nuclear, Calle 34 x 41, Exterrenos el Fenix s/n, Col. Industrial, 91750 Merida, Yucatan (Mexico)

    2010-09-15

    The objective of the present work was to determine if the application of the Na hypochlorite has some utility in the radioactive decontamination, in comparison with the water, detergent and alcohol. Several methods were compared for decontaminate the iodine 131 and technetium 99, the work table and the skin it was carried out an initial count with the Geiger Muller. Later on, in a single occasion, the areas were washed with abundant water, alcohol, clothes detergent and sodium hypochlorite (used commercially as domestic bleacher) without diluting. Observing that the percentage in the decrease of the counted radioactivity by the Geiger Muller, decreased in the following way: It was demonstrated that the Na hypochlorite presents the highest index of radioactive decontamination with 100% of effectiveness. The Na hypochlorite is an excellent substance that can be used with effectiveness and efficiency like decontamination element in the accident cases of radioactive contamination in the clinical laboratories of nuclear medicine. (Author)

  1. Propagation velocity of an avalanche along the anode wire in a Geiger-Mueller counter filled with Q-gas at 1 ATM

    International Nuclear Information System (INIS)

    Matsuda, Kazunori; Sanada, Junpei

    1990-01-01

    Simple methods were applied to investigate the characteristics of a Geiger-Mueller counter with Q-gas flowing at 1 atm. The propagation velocity of the photon-aided avalanche along the anode wire depends linearly on the strength of the electric field in the counter. Its fluctuation (FWHM) as a function of distance between the source position and the end point is discussed. (orig.)

  2. A discrete model of the development and relaxation of a local microbreakdown in silicon avalanche photodiodes operating in the Geiger mode

    International Nuclear Information System (INIS)

    Vanyushin, I. V.; Gergel, V. A.; Gontar', V. M.; Zimoglyad, V. A.; Tishin, Yu. I.; Kholodnov, V. A.; Shcheleva, I. M.

    2007-01-01

    A new discrete theoretical model of the development and relaxation of a local microbreakdown in silicon avalanche photodiodes operating in the Geiger mode is developed. It is shown that the spreading resistance in the substrate profoundly affects both the amplitude of a single-photon electrical pulse and the possibility of attaining the steady-state form of the avalanche breakdown excluding the Geiger mode of the photodiode's operation. The model is employed to interpret the experimental data obtained using test single-photon cells of avalanche photodiodes fabricated on the basis of the 0.25-μm silicon technology with the use of deep implantation to form the region of avalanche multiplication for the charge carriers. Excellent functional properties of the studied type of the single-photon (Geiger) cell are noted. A typical amplitude characteristic of the cell for optical radiation with the wavelength λ = 0.56 μm in the irradiance range of 10 -3 -10 2 lx is presented; this characteristic indicates that the quantum efficiency of photoconversion is extremely high

  3. Opposing Actions of Fgf8a on Notch Signaling Distinguish Two Muller Glial Cell Populations that Contribute to Retina Growth and Regeneration

    Directory of Open Access Journals (Sweden)

    Jin Wan

    2017-04-01

    Full Text Available The teleost retina grows throughout life and exhibits a robust regenerative response following injury. Critical to both these events are Muller glia (or, Muller glial cells; MGs, which produce progenitors for retinal growth and repair. We report that Fgf8a may be an MG niche factor that acts through Notch signaling to regulate spontaneous and injury-dependent MG proliferation. Remarkably, forced Fgf8a expression inhibits Notch signaling and stimulates MG proliferation in young tissue but increases Notch signaling and suppresses MG proliferation in older tissue. Furthermore, cessation of Fgf8a signaling enhances MG proliferation in both young and old retinal tissue. Our study suggests that multiple MG populations contribute to retinal growth and regeneration, and it reveals a previously unappreciated role for Fgf8a and Notch signaling in regulating MG quiescence, activation, and proliferation.

  4. Radiation counting statistics

    Energy Technology Data Exchange (ETDEWEB)

    Suh, M. Y.; Jee, K. Y.; Park, K. K.; Park, Y. J.; Kim, W. H

    1999-08-01

    This report is intended to describe the statistical methods necessary to design and conduct radiation counting experiments and evaluate the data from the experiment. The methods are described for the evaluation of the stability of a counting system and the estimation of the precision of counting data by application of probability distribution models. The methods for the determination of the uncertainty of the results calculated from the number of counts, as well as various statistical methods for the reduction of counting error are also described. (Author). 11 refs., 8 tabs., 8 figs.

  5. Radiation counting statistics

    Energy Technology Data Exchange (ETDEWEB)

    Suh, M. Y.; Jee, K. Y.; Park, K. K. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-08-01

    This report is intended to describe the statistical methods necessary to design and conduct radiation counting experiments and evaluate the data from the experiments. The methods are described for the evaluation of the stability of a counting system and the estimation of the precision of counting data by application of probability distribution models. The methods for the determination of the uncertainty of the results calculated from the number of counts, as well as various statistical methods for the reduction of counting error are also described. 11 refs., 6 figs., 8 tabs. (Author)

  6. Radiation counting statistics

    International Nuclear Information System (INIS)

    Suh, M. Y.; Jee, K. Y.; Park, K. K.; Park, Y. J.; Kim, W. H.

    1999-08-01

    This report is intended to describe the statistical methods necessary to design and conduct radiation counting experiments and evaluate the data from the experiment. The methods are described for the evaluation of the stability of a counting system and the estimation of the precision of counting data by application of probability distribution models. The methods for the determination of the uncertainty of the results calculated from the number of counts, as well as various statistical methods for the reduction of counting error are also described. (Author). 11 refs., 8 tabs., 8 figs

  7. Magnetic Random Access Memory based non-volatile asynchronous Muller cell for ultra-low power autonomous applications

    Science.gov (United States)

    Di Pendina, G.; Zianbetov, E.; Beigne, E.

    2015-05-01

    Micro and nano electronic integrated circuit domain is today mainly driven by the advent of the Internet of Things for which the constraints are strong, especially in terms of power consumption and autonomy, not only during the computing phases but also during the standby or idle phases. In such ultra-low power applications, the circuit has to meet new constraints mainly linked to its changing energetic environment: long idle phases, automatic wake up, data back-up when the circuit is sporadically turned off, and ultra-low voltage power supply operation. Such circuits have to be completely autonomous regarding their unstable environment, while remaining in an optimum energetic configuration. Therefore, we propose in this paper the first MRAM-based non-volatile asynchronous Muller cell. This cell has been simulated and characterized in a very advanced 28 nm CMOS fully depleted silicon-on-insulator technology, presenting good power performance results due to an extremely efficient body biasing control together with ultra-wide supply voltage range from 160 mV up to 920 mV. The leakage current can be reduced to 154 pA thanks to reverse body biasing. We also propose an efficient standard CMOS bulk version of this cell in order to be compatible with different fabrication processes.

  8. Magnetic Random Access Memory based non-volatile asynchronous Muller cell for ultra-low power autonomous applications

    Energy Technology Data Exchange (ETDEWEB)

    Di Pendina, G., E-mail: gregory.dipendina@cea.fr, E-mail: eldar.zianbetov@cea.fr, E-mail: edith.beigne@cea.fr; Zianbetov, E., E-mail: gregory.dipendina@cea.fr, E-mail: eldar.zianbetov@cea.fr, E-mail: edith.beigne@cea.fr [Univ. Grenoble Alpes, INAC-SPINTEC, F-38000 Grenoble (France); CNRS, SPINTEC, F-38000 Grenoble (France); CEA, INAC-SPINTEC, F-38000 Grenoble (France); Beigne, E., E-mail: gregory.dipendina@cea.fr, E-mail: eldar.zianbetov@cea.fr, E-mail: edith.beigne@cea.fr [Univ. Grenoble Alpes, CEA, LETI, F-38000 Grenoble (France)

    2015-05-07

    Micro and nano electronic integrated circuit domain is today mainly driven by the advent of the Internet of Things for which the constraints are strong, especially in terms of power consumption and autonomy, not only during the computing phases but also during the standby or idle phases. In such ultra-low power applications, the circuit has to meet new constraints mainly linked to its changing energetic environment: long idle phases, automatic wake up, data back-up when the circuit is sporadically turned off, and ultra-low voltage power supply operation. Such circuits have to be completely autonomous regarding their unstable environment, while remaining in an optimum energetic configuration. Therefore, we propose in this paper the first MRAM-based non-volatile asynchronous Muller cell. This cell has been simulated and characterized in a very advanced 28 nm CMOS fully depleted silicon-on-insulator technology, presenting good power performance results due to an extremely efficient body biasing control together with ultra-wide supply voltage range from 160 mV up to 920 mV. The leakage current can be reduced to 154 pA thanks to reverse body biasing. We also propose an efficient standard CMOS bulk version of this cell in order to be compatible with different fabrication processes.

  9. Magnetic Random Access Memory based non-volatile asynchronous Muller cell for ultra-low power autonomous applications

    International Nuclear Information System (INIS)

    Di Pendina, G.; Zianbetov, E.; Beigne, E.

    2015-01-01

    Micro and nano electronic integrated circuit domain is today mainly driven by the advent of the Internet of Things for which the constraints are strong, especially in terms of power consumption and autonomy, not only during the computing phases but also during the standby or idle phases. In such ultra-low power applications, the circuit has to meet new constraints mainly linked to its changing energetic environment: long idle phases, automatic wake up, data back-up when the circuit is sporadically turned off, and ultra-low voltage power supply operation. Such circuits have to be completely autonomous regarding their unstable environment, while remaining in an optimum energetic configuration. Therefore, we propose in this paper the first MRAM-based non-volatile asynchronous Muller cell. This cell has been simulated and characterized in a very advanced 28 nm CMOS fully depleted silicon-on-insulator technology, presenting good power performance results due to an extremely efficient body biasing control together with ultra-wide supply voltage range from 160 mV up to 920 mV. The leakage current can be reduced to 154 pA thanks to reverse body biasing. We also propose an efficient standard CMOS bulk version of this cell in order to be compatible with different fabrication processes

  10. Modelization, fabrication and evaluation avalanche photodiodes polarized in Geiger mode for the single photon in astrophysics applications; Modelisation, fabrication et evaluation des photodiodes a avalanche polarisees en mode Geiger pour la detection du photon unique dans les applications Astrophysiques

    Energy Technology Data Exchange (ETDEWEB)

    Pellion, D

    2008-12-15

    The genesis of the work presented in this this is in the field of very high energy astrophysics. One century ago, scientists identified a new type of messenger coming from space: cosmic rays. This radiation consists of particles (photons or other) of very high energy which bombard the Earth permanently. The passage of cosmic radiations in the Earth's atmosphere results in the creation of briefs luminous flashes (5 ns) of very low intensity (1 pW), a Cherenkov flash, and then becomes visible on the ground. In the current state of the art the best detector of light today is the Photomultiplier tube (PMT), thanks to its characteristics of sensitivity and speed. But there are some drawbacks: low quantum efficiency, cost, weight etc. We present in this thesis a new alternative technology: silicon photon counters, made of photodiodes polarized in Geiger mode. This operating mode makes it possible to obtain an effect of multiplication comparable to that of the PMT. A physical and electrical model was developed to reproduce the behaviour of this detector. We then present in this thesis work an original technological process allowing the realization of these devices in the Center of Technology of LAAS-CNRS, with the simulation of each operation of the process. We developed a scheme for the electric characterization of the device, from the static mode to the dynamic mode, in order to check conformity with SILVACO simulations and to the initial model. Results are already excellent, given this is only a first prototype step, and comparable with the results published in the literature. These silicon devices can intervene in all the applications where there is a photomultiplier and replace it. The applications are thus very numerous and the growth of the market of these detectors is very fast. We present a first astrophysical experiment installed at the 'Pic du Midi' site which has detected Cherenkov flashes from cosmic rays with this new semiconductor technology

  11. Modelization, fabrication and evaluation avalanche photodiodes polarized in Geiger mode for the single photon in astrophysics applications

    International Nuclear Information System (INIS)

    Pellion, D.

    2008-12-01

    The genesis of the work presented in this this is in the field of very high energy astrophysics. One century ago, scientists identified a new type of messenger coming from space: cosmic rays. This radiation consists of particles (photons or other) of very high energy which bombard the Earth permanently. The passage of cosmic radiations in the Earth's atmosphere results in the creation of briefs luminous flashes (5 ns) of very low intensity (1 pW), a Cherenkov flash, and then becomes visible on the ground. In the current state of the art the best detector of light today is the Photomultiplier tube (PMT), thanks to its characteristics of sensitivity and speed. But there are some drawbacks: low quantum efficiency, cost, weight etc. We present in this thesis a new alternative technology: silicon photon counters, made of photodiodes polarized in Geiger mode. This operating mode makes it possible to obtain an effect of multiplication comparable to that of the PMT. A physical and electrical model was developed to reproduce the behaviour of this detector. We then present in this thesis work an original technological process allowing the realization of these devices in the Center of Technology of LAAS-CNRS, with the simulation of each operation of the process. We developed a scheme for the electric characterization of the device, from the static mode to the dynamic mode, in order to check conformity with SILVACO simulations and to the initial model. Results are already excellent, given this is only a first prototype step, and comparable with the results published in the literature. These silicon devices can intervene in all the applications where there is a photomultiplier and replace it. The applications are thus very numerous and the growth of the market of these detectors is very fast. We present a first astrophysical experiment installed at the 'Pic du Midi' site which has detected Cherenkov flashes from cosmic rays with this new semiconductor technology. (author)

  12. Implementation of human thermal comfort information in Köppen-Geiger climate classification—the example of China

    Science.gov (United States)

    Yang, Shi-Qi; Matzarakis, Andreas

    2016-11-01

    Köppen-Geiger climate classification (KGC) is accepted and applied worldwide. The climatic parameters utilised in KGC, however, cannot indicate human thermal comfort (HTC) conditions or air humidity (AH) conditions directly, because they are originally based on climatic effects on vegetation, instead of that on human body directly. In addition, HTC is driven by meteorological parameters together. Thus, the objective of this study is to preliminarily implement the HTC information and the AH information in KGC. Physiologically equivalent temperature (PET) has been chosen as the HTC index, and vapour pressure (VP) is for the quantification of AH conditions. In this preliminary study, 12 Chinese cities in total have been taken into account as the assumed representatives of 11 climate types. Basic meteorological data of each city with 3-h resolution in 2000-2012 has been analysed. RayMan model has been applied to calculate PET within the same time period. Each climate type has been described by frequencies of PET and frequencies of VP. For example, the Aw (Sanya) has the most frequent occurrence of thermally stressful conditions compared to other climate types: PET in 22 % points in time of the year was above 35 °C. The driest AH conditions existed in Dwc (Lhasa) and Dfb (Urumqi) with VP rarely above 18 hPa in the wettest month. Implementation of the HTC information and the additional AH information in each climate type of KGC can be helpful for the topics of human health, energy consumption, tourism, as well as urban planning.

  13. Implementation of human thermal comfort information in Köppen-Geiger climate classification-the example of China.

    Science.gov (United States)

    Yang, Shi-Qi; Matzarakis, Andreas

    2016-11-01

    Köppen-Geiger climate classification (KGC) is accepted and applied worldwide. The climatic parameters utilised in KGC, however, cannot indicate human thermal comfort (HTC) conditions or air humidity (AH) conditions directly, because they are originally based on climatic effects on vegetation, instead of that on human body directly. In addition, HTC is driven by meteorological parameters together. Thus, the objective of this study is to preliminarily implement the HTC information and the AH information in KGC. Physiologically equivalent temperature (PET) has been chosen as the HTC index, and vapour pressure (VP) is for the quantification of AH conditions. In this preliminary study, 12 Chinese cities in total have been taken into account as the assumed representatives of 11 climate types. Basic meteorological data of each city with 3-h resolution in 2000-2012 has been analysed. RayMan model has been applied to calculate PET within the same time period. Each climate type has been described by frequencies of PET and frequencies of VP. For example, the Aw (Sanya) has the most frequent occurrence of thermally stressful conditions compared to other climate types: PET in 22 % points in time of the year was above 35 °C. The driest AH conditions existed in Dwc (Lhasa) and Dfb (Urumqi) with VP rarely above 18 hPa in the wettest month. Implementation of the HTC information and the additional AH information in each climate type of KGC can be helpful for the topics of human health, energy consumption, tourism, as well as urban planning.

  14. Shared Reed-Muller Decision Diagram Based Thermal-Aware AND-XOR Decomposition of Logic Circuits

    Directory of Open Access Journals (Sweden)

    Apangshu Das

    2016-01-01

    Full Text Available The increased number of complex functional units exerts high power-density within a very-large-scale integration (VLSI chip which results in overheating. Power-densities directly converge into temperature which reduces the yield of the circuit. An adverse effect of power-density reduction is the increase in area. So, there is a trade-off between area and power-density. In this paper, we introduce a Shared Reed-Muller Decision Diagram (SRMDD based on fixed polarity AND-XOR decomposition to represent multioutput Boolean functions. By recursively applying transformations and reductions, we obtained a compact SRMDD. A heuristic based on Genetic Algorithm (GA increases the sharing of product terms by judicious choice of polarity of input variables in SRMDD expansion and a suitable area and power-density trade-off has been enumerated. This is the first effort ever to incorporate the power-density as a measure of temperature estimation in AND-XOR expansion process. The results of logic synthesis are incorporated with physical design in CADENCE digital synthesis tool to obtain the floor-plan silicon area and power profile. The proposed thermal-aware synthesis has been validated by obtaining absolute temperature of the synthesized circuits using HotSpot tool. We have experimented with 29 benchmark circuits. The minimized AND-XOR circuit realization shows average savings up to 15.23% improvement in silicon area and up to 17.02% improvement in temperature over the sum-of-product (SOP based logic minimization.

  15. Platelet Count and Plateletcrit

    African Journals Online (AJOL)

    strated that neonates with late onset sepsis (bacteremia after 3 days of age) had a dramatic increase in MPV and. PDW18. We hypothesize that as the MPV and PDW increase and platelet count and PCT decrease in sick children, intui- tively, the ratio of MPV to PCT; MPV to Platelet count,. PDW to PCT, PDW to platelet ...

  16. EcoCount

    Directory of Open Access Journals (Sweden)

    Phillip P. Allen

    2014-05-01

    Full Text Available Techniques that analyze biological remains from sediment sequences for environmental reconstructions are well established and widely used. Yet, identifying, counting, and recording biological evidence such as pollen grains remain a highly skilled, demanding, and time-consuming task. Standard procedure requires the classification and recording of between 300 and 500 pollen grains from each representative sample. Recording the data from a pollen count requires significant effort and focused resources from the palynologist. However, when an adaptation to the recording procedure is utilized, efficiency and time economy improve. We describe EcoCount, which represents a development in environmental data recording procedure. EcoCount is a voice activated fully customizable digital count sheet that allows the investigator to continuously interact with a field of view during the data recording. Continuous viewing allows the palynologist the opportunity to remain engaged with the essential task, identification, for longer, making pollen counting more efficient and economical. EcoCount is a versatile software package that can be used to record a variety of environmental evidence and can be installed onto different computer platforms, making the adoption by users and laboratories simple and inexpensive. The user-friendly format of EcoCount allows any novice to be competent and functional in a very short time.

  17. Clean Hands Count

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  18. Counting It Twice.

    Science.gov (United States)

    Schattschneider, Doris

    1991-01-01

    Provided are examples from many domains of mathematics that illustrate the Fubini Principle in its discrete version: the value of a summation over a rectangular array is independent of the order of summation. Included are: counting using partitions as in proof by pictures, combinatorial arguments, indirect counting as in the inclusion-exclusion…

  19. A new approach to beta-gamma coincidence counting. Advance report on the Samar electronic system

    International Nuclear Information System (INIS)

    Carlos, J. E. de; Granados, C. E.

    1972-01-01

    In 4π β-γ coincidence measurements, precision on the evaluation of coincidence counting losses is made difficult because of complex overlapping effects between theβ--and γ-side dead times due to pre cursive counted events. In this context the SAMAR electronic system is aimed to give a precise way of automatic counting and reduce the need for calculated corrections. This report describes its configuration and basic features. The SAMAR has been conceived in such a manner that both beta and gamma chains are sharing a common and non extending dead-time which is simultaneously applied to both channels. The shared dead time is made to be the only one inserted throughout the chains. Overlapping effects vanish and the three counting channels have identical transmission ratios. A new dead-time circuit based on fast linear gates as blocking elements has been developed. Application of the two-oscillator Muller's method evidences a fully non-extending character. Automatism is implemented by using a live timer corrective channel controlling the counting scalers. (Author) 21 refs

  20. Clean Hands Count

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  1. Clean Hands Count

    Medline Plus

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  2. Housing Inventory Count

    Data.gov (United States)

    Department of Housing and Urban Development — This report displays the data communities reported to HUD about the nature of their dedicated homeless inventory, referred to as their Housing Inventory Count (HIC)....

  3. Scintillation counting apparatus

    International Nuclear Information System (INIS)

    Noakes, J.E.

    1978-01-01

    Apparatus is described for the accurate measurement of radiation by means of scintillation counters and in particular for the liquid scintillation counting of both soft beta radiation and gamma radiation. Full constructional and operating details are given. (UK)

  4. Allegheny County Traffic Counts

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Traffic sensors at over 1,200 locations in Allegheny County collect vehicle counts for the Pennsylvania Department of Transportation. Data included in the Health...

  5. Counting Knights and Knaves

    Science.gov (United States)

    Levin,Oscar; Roberts, Gerri M.

    2013-01-01

    To understand better some of the classic knights and knaves puzzles, we count them. Doing so reveals a surprising connection between puzzles and solutions, and highlights some beautiful combinatorial identities.

  6. Clean Hands Count

    Medline Plus

    Full Text Available ... why Close Clean Hands Count Centers for Disease Control and Prevention (CDC) Loading... Unsubscribe from Centers for Disease Control and Prevention (CDC)? Cancel Unsubscribe Working... Subscribe Subscribed ...

  7. Clean Hands Count

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  8. A vegetal Geiger counter

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    In order to study the Chernobyl accident impact on ecosystems, Ukrainian and Swiss scientists have used a plant: the Arabidopsis thaliana. They have introduced in its genome a gene coding an enzyme called β-glucuronidase. This substance, when it is expressed, colours vegetal cells blue. In fact the introduced gene is divided between 2 paired chromosomes. When the plant is placed on a nuclear contaminated soil, radiation damaged chromosomes exchange fragments and the 2 parts of the enzyme gene may recombine, the enzyme can then be expressed. For low and medium contamination ( 2 ) biologists have found a correlation between the number of blue spots on the plant and the irradiation rate. (A.C.)

  9. Geiger Counter Technique

    Science.gov (United States)

    1942-01-01

    ONLY; ADMINISTRATIVE/OPERATIONAL USE; 03 MAR 1999. OTHER REQUESTS SHALL BE REFERRED THROUGH COMMANDING OFFICER, NAVAL RESEARCH LAB , WASHINGTON, DC 20375...Used as Glow Tube Voltage + " -- -+a...... .-..... . .... . . . . . .. . . Plate 41. Tar of aCotrolust Voltaep with Gas Pressure lab A-gtarator of’ Plate...construation cf vapor comatera. Acst Lay metal wll menru as cathode aterial, but oxidiste copper Lad bras han given beest res-ts. fe ride choice of

  10. The Kruskal Count

    OpenAIRE

    Lagarias, Jeffrey C.; Rains, Eric; Vanderbei, Robert J.

    2001-01-01

    The Kruskal Count is a card trick invented by Martin J. Kruskal in which a magician "guesses" a card selected by a subject according to a certain counting procedure. With high probability the magician can correctly "guess" the card. The success of the trick is based on a mathematical principle related to coupling methods for Markov chains. This paper analyzes in detail two simplified variants of the trick and estimates the probability of success. The model predictions are compared with simula...

  11. Low White Blood Cell Count

    Science.gov (United States)

    Symptoms Low white blood cell count By Mayo Clinic Staff A low white blood cell count (leukopenia) is a decrease ... of white blood cell (neutrophil). The definition of low white blood cell count varies from one medical ...

  12. Differential occurrence of chromosome inversion polymorphisms among Muller's elements in three species of the tripunctata group of Drosophila, including a species with fast chromosomal evolution.

    Science.gov (United States)

    Brianti, Mitsue T; Ananina, Galina; Klaczko, Louis B

    2013-01-01

    Detailed chromosome maps with reliable homologies among chromosomes of different species are the first step to study the evolution of the genetic architecture in any set of species. Here, we present detailed photo maps of the polytene chromosomes of three closely related species of the tripunctata group (subgenus Drosophila): Drosophila mediopunctata, D. roehrae, and D. unipunctata. We identified Muller's elements in each species, using FISH, establishing reliable chromosome homologies among species and D. melanogaster. The simultaneous analysis of chromosome inversions revealed a distribution pattern for the inversion polymorphisms among Muller's elements in the three species. Element E is the most polymorphic, with many inversions in each species. Element C follows; while the least polymorphic elements are B and D. While interesting, it remains to be determined how general this pattern is among species of the tripunctata group. Despite previous studies showing that D. mediopunctata and D. unipunctata are phylogenetically closer to each other than to D. roehrae, D. unipunctata shows rare karyotypic changes. It has two chromosome fusions: an additional heterochromatic chromosome pair and a pericentric inversion in the X chromosome. This especial conformation suggests a fast chromosomal evolution that deserves further study.

  13. The threshold vs LNT showdown: Dose rate findings exposed flaws in the LNT model part 1. The Russell-Muller debate

    Energy Technology Data Exchange (ETDEWEB)

    Calabrese, Edward J., E-mail: edwardc@schoolph.umass.edu

    2017-04-15

    This paper assesses the discovery of the dose-rate effect in radiation genetics and how it challenged fundamental tenets of the linear non-threshold (LNT) dose response model, including the assumptions that all mutational damage is cumulative and irreversible and that the dose-response is linear at low doses. Newly uncovered historical information also describes how a key 1964 report by the International Commission for Radiological Protection (ICRP) addressed the effects of dose rate in the assessment of genetic risk. This unique story involves assessments by two leading radiation geneticists, Hermann J. Muller and William L. Russell, who independently argued that the report's Genetic Summary Section on dose rate was incorrect while simultaneously offering vastly different views as to what the report's summary should have contained. This paper reveals occurrences of scientific disagreements, how conflicts were resolved, which view(s) prevailed and why. During this process the Nobel Laureate, Muller, provided incorrect information to the ICRP in what appears to have been an attempt to manipulate the decision-making process and to prevent the dose-rate concept from being adopted into risk assessment practices. - Highlights: • The discovery of radiation dose rate challenged the scientific basis of LNT. • Radiation dose rate occurred in males and females. • The dose rate concept supported a threshold dose-response for radiation.

  14. The threshold vs LNT showdown: Dose rate findings exposed flaws in the LNT model part 1. The Russell-Muller debate

    International Nuclear Information System (INIS)

    Calabrese, Edward J.

    2017-01-01

    This paper assesses the discovery of the dose-rate effect in radiation genetics and how it challenged fundamental tenets of the linear non-threshold (LNT) dose response model, including the assumptions that all mutational damage is cumulative and irreversible and that the dose-response is linear at low doses. Newly uncovered historical information also describes how a key 1964 report by the International Commission for Radiological Protection (ICRP) addressed the effects of dose rate in the assessment of genetic risk. This unique story involves assessments by two leading radiation geneticists, Hermann J. Muller and William L. Russell, who independently argued that the report's Genetic Summary Section on dose rate was incorrect while simultaneously offering vastly different views as to what the report's summary should have contained. This paper reveals occurrences of scientific disagreements, how conflicts were resolved, which view(s) prevailed and why. During this process the Nobel Laureate, Muller, provided incorrect information to the ICRP in what appears to have been an attempt to manipulate the decision-making process and to prevent the dose-rate concept from being adopted into risk assessment practices. - Highlights: • The discovery of radiation dose rate challenged the scientific basis of LNT. • Radiation dose rate occurred in males and females. • The dose rate concept supported a threshold dose-response for radiation.

  15. Alpha scintillation radon counting

    International Nuclear Information System (INIS)

    Lucas, H.F. Jr.

    1977-01-01

    Radon counting chambers which utilize the alpha-scintillation properties of silver activated zinc sulfide are simple to construct, have a high efficiency, and, with proper design, may be relatively insensitive to variations in the pressure or purity of the counter filling. Chambers which were constructed from glass, metal, or plastic in a wide variety of shapes and sizes were evaluated for the accuracy and the precision of the radon counting. The principles affecting the alpha-scintillation radon counting chamber design and an analytic system suitable for a large scale study of the 222 Rn and 226 Ra content of either air or other environmental samples are described. Particular note is taken of those factors which affect the accuracy and the precision of the method for monitoring radioactivity around uranium mines

  16. Principles of correlation counting

    International Nuclear Information System (INIS)

    Mueller, J.W.

    1975-01-01

    A review is given of the various applications which have been made of correlation techniques in the field of nuclear physics, in particular for absolute counting. Whereas in most cases the usual coincidence method will be preferable for its simplicity, correlation counting may be the only possible approach in such cases where the two radiations of the cascade cannot be well separated or when there is a longliving intermediate state. The measurement of half-lives and of count rates of spurious pulses is also briefly discussed. The various experimental situations lead to different ways the correlation method is best applied (covariance technique with one or with two detectors, application of correlation functions, etc.). Formulae are given for some simple model cases, neglecting dead-time corrections

  17. Interpretation of galaxy counts

    International Nuclear Information System (INIS)

    Tinsely, B.M.

    1980-01-01

    New models are presented for the interpretation of recent counts of galaxies to 24th magnitude, and predictions are shown to 28th magnitude for future comparison with data from the Space Telescope. The results supersede earlier, more schematic models by the author. Tyson and Jarvis found in their counts a ''local'' density enhancement at 17th magnitude, on comparison with the earlier models; the excess is no longer significant when a more realistic mixture of galaxy colors is used. Bruzual and Kron's conclusion that Kron's counts show evidence for evolution at faint magnitudes is confirmed, and it is predicted that some 23d magnitude galaxies have redshifts greater than unity. These may include spheroidal systems, elliptical galaxies, and the bulges of early-type spirals and S0's, seen during their primeval rapid star formation

  18. Computerized radioautographic grain counting

    International Nuclear Information System (INIS)

    McKanna, J.A.; Casagrande, V.A.

    1985-01-01

    In recent years, radiolabeling techniques have become fundamental assays in physiology and biochemistry experiments. They also have assumed increasingly important roles in morphologic studies. Characteristically, radioautographic analysis of structure has been qualitative rather than quantitative, however, microcomputers have opened the door to several methods for quantifying grain counts and density. The overall goal of this chapter is to describe grain counting using the Bioquant, an image analysis package based originally on the Apple II+, and now available for several popular microcomputers. The authors discuss their image analysis procedures by applying them to a study of development in the central nervous system

  19. Rainflow counting revisited

    Energy Technology Data Exchange (ETDEWEB)

    Soeker, H [Deutsches Windenergie-Institut (Germany)

    1996-09-01

    As state of the art method the rainflow counting technique is presently applied everywhere in fatigue analysis. However, the author feels that the potential of the technique is not fully recognized in wind energy industries as it is used, most of the times, as a mere data reduction technique disregarding some of the inherent information of the rainflow counting results. The ideas described in the following aim at exploitation of this information and making it available for use in the design and verification process. (au)

  20. Direct photon-counting scintillation detector readout using an SSPM

    International Nuclear Information System (INIS)

    Stapels, Christopher J.; Squillante, Michael R.; Lawrence, William G.; Augustine, Frank L.; Christian, James F.

    2007-01-01

    Gamma-ray detector technologies, capable of providing adequate energy information, use photomultiplier tubes (PMTs) or silicon avalanche photodiodes to detect the light pulse from a scintillation crystal. A new approach to detect the light from scintillation materials is to use an array of small photon counting detectors, or a 'detector-on-a-chip' based on a novel 'Solid-state Photomultiplier' (SSPM) concept. A CMOS SSPM coupled to a scintillation crystal uses an array of CMOS Geiger photodiode (GPD) pixels to collect light and produce a signal proportional to the energy of the radiation. Each pixel acts as a binary photon detector, but the summed output is an analog representation of the total photon intensity. We have successfully fabricated arrays of GPD pixels in a CMOS environment, which makes possible the production of miniaturized arrays integrated with the detector electronics in a small silicon chip. This detector technology allows for a substantial cost reduction while preserving the energy resolution needed for radiological measurements. In this work, we compare designs for the SSPM detector. One pixel design achieves maximum detection efficiency (DE) for 632-nm photons approaching 30% with a room temperature dark count rate (DCR) of less than 1 kHz for a 30-μm-diameter pixel. We characterize after pulsing and optical cross talk and discuss their effects on the performance of the SSPM. For 30-μm diameter, passively quenched CMOS GPD pixels, modeling suggests that a pixel spacing of approximately 90 μm optimizes the SSPM performance with respect to DE and cross talk

  1. Clean Hands Count

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  12. Clean Hands Count

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  15. Reticulocyte Count Test

    Science.gov (United States)

    ... htm. (2004 Summer). Immature Reticulocyte Fraction(IRF). The Pathology Center Newsletter v9(1). [On-line information]. Available ... Company, Philadelphia, PA [18th Edition]. Levin, M. (2007 March 8, Updated). Reticulocyte Count. MedlinePlus Medical Encyclopedia [On- ...

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  18. Calorie count - fast food

    Science.gov (United States)

    ... GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Calorie count - fast food URL of this page: //medlineplus.gov/ency/patientinstructions/ ...

  19. Fast counting electronics for neutron coincidence counting

    International Nuclear Information System (INIS)

    Swansen, J.E.

    1987-01-01

    This patent describes a high speed circuit for accurate neutron coincidence counting comprising: neutron detecting means for providing an above-threshold signal upon neutron detection; amplifying means inputted by the neutron detecting means for providing a pulse output having a pulse width of about 0.5 microseconds upon the input of each above threshold signal; digital processing means inputted by the pulse output of the amplifying means for generating a pulse responsive to each input pulse from the amplifying means and having a pulse width of about 50 nanoseconds effective for processing an expected neutron event rate of about 1 Mpps: pulse stretching means inputted by the digital processing means for producing a pulse having a pulse width of several milliseconds for each pulse received form the digital processing means; visual indicating means inputted by the pulse stretching means for producing a visual output for each pulse received from the digital processing means; and derandomizing means effective to receive the 50 ns neutron event pulses from the digital processing means for storage at a rate up to the neutron event rate of 1 Mpps and having first counter means for storing the input neutron event pulses

  20. Characteristics and fabrication of Geiger-Mueller counters with thin walls made of treated magnesium - Note about the use of araldite

    International Nuclear Information System (INIS)

    Charbonnel, A.

    1949-03-01

    This report describes, first, the advantage of magnesium for the manufacturing of Geiger-Mueller counters: suitable for machining and polishing, but strong reactivity with the counter atmosphere in the case of magnesium-rich alloys. Thus, the inside wall of the counter (cylinder of 20 mm diameter and 6 cm length) requires a non-reactive protective coating with excellent sealing properties. The synthetic resin 'araldite' fulfills all these conditions. The second part of the report describes the different steps of the fabrication of magnesium wall counters: lathe work, machining down and chemical polishing of hulls, assembly, tight sealing, pumping, filling-up and control tests. The average service life of these counters is of about 4 months. A note about the use and properties (hardening, mechanical properties, resistance..) of araldite is given in appendix. (J.S.)

  1. Mapping Weathering and Alteration Minerals in the Comstock and Geiger Grade Areas using Visible to Thermal Infrared Airborne Remote Sensing Data

    Science.gov (United States)

    Vaughan, Greg R.; Calvin, Wendy M.

    2005-01-01

    To support research into both precious metal exploration and environmental site characterization a combination of high spatial/spectral resolution airborne visible, near infrared, short wave infrared (VNIR/SWIR) and thermal infrared (TIR) image data were acquired to remotely map hydrothermal alteration minerals around the Geiger Grade and Comstock alteration regions, and map the mineral by-products of weathered mine dumps in Virginia City. Remote sensing data from the Airborne Visible Infrared Imaging Spectrometer (AVIRIS), SpecTIR Corporation's airborne hyperspectral imager (HyperSpecTIR), the MODIS-ASTER airborne simulator (MASTER), and the Spatially Enhanced Broadband Array Spectrograph System (SEBASS) were acquired and processed into mineral maps based on the unique spectral signatures of image pixels. VNIR/SWIR and TIR field spectrometer data were collected for both calibration and validation of the remote data sets, and field sampling, laboratory spectral analyses and XRD analyses were made to corroborate the surface mineralogy identified by spectroscopy. The resulting mineral maps show the spatial distribution of several important alteration minerals around each study area including alunite, quartz, pyrophyllite, kaolinite, montmorillonite/muscovite, and chlorite. In the Comstock region the mineral maps show acid-sulfate alteration, widespread propylitic alteration and extensive faulting that offsets the acid-sulfate areas, in contrast to the larger, dominantly acid-sulfate alteration exposed along Geiger Grade. Also, different mineral zones within the intense acid-sulfate areas were mapped. In the Virginia City historic mining district the important weathering minerals mapped include hematite, goethite, jarosite and hydrous sulfate minerals (hexahydrite, alunogen and gypsum) located on mine dumps. Sulfate minerals indicate acidic water forming in the mine dump environment. While there is not an immediate threat to the community, there are clearly sources of

  2. Comparação dos caldos selenito cistina, tetrationato Muller-Kauffmann e Rappaport-Vassiliadis no isolamento de Salmonella Typhimurium

    Directory of Open Access Journals (Sweden)

    L.G. Ávila

    2012-06-01

    Full Text Available Three selective enrichment broths - selenite cystine (SC, Muller-Kauffmann tetrathionate (MKT and Rappaport-Vassiliadis (RV - were compared, for Salmonella Typhimurium isolation from rectal swabs of a calf experimentally infected. The bacteriological procedure involved pre-enrichment in Hajna-GN broth (only for the samples inoculated in RV broth, selective enrichment (SC, MKT and RV broths, culture in modified brilliant green agar (BGA, presumptive biochemistry tests (using triple-sugar-iron agar and lysine-agar and slide agglutination test with poli-O and poli-H Salmonella antisera. SC and MKT broths were more efficient in the isolation of Salmonella Typhimurium (12 positive samples, whereas RV broth had a lower efficiency in the microbiological isolation (ten positive samples.

  3. CalCOFI Egg Counts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish egg counts and standardized counts for eggs captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets], and...

  4. Counting statistics in radioactivity measurements

    International Nuclear Information System (INIS)

    Martin, J.

    1975-01-01

    The application of statistical methods to radioactivity measurement problems is analyzed in several chapters devoted successively to: the statistical nature of radioactivity counts; the application to radioactive counting of two theoretical probability distributions, Poisson's distribution law and the Laplace-Gauss law; true counting laws; corrections related to the nature of the apparatus; statistical techniques in gamma spectrometry [fr

  5. Do your syringes count?

    International Nuclear Information System (INIS)

    Brewster, K.

    2002-01-01

    Full text: This study was designed to investigate anecdotal evidence that residual Sestamibi (MIBI) activity vaned in certain situations. For rest studies different brands of syringes were tested to see if the residuals varied. The period of time MIBI doses remained in the syringe between dispensing and injection was also considered as a possible source of increased residual counts. Stress Mibi syringe residual activities were measured to assess if the method of stress test affected residual activity. MIBI was reconstituted using 13 Gbq of Technetium in 3mls of normal saline then boiled for 10 minutes. Doses were dispensed according to department protocol and injected via cannula. Residual syringes were collected for three syringe types. In each case the barrel and plunger were measured separately. As the syringe is flushed during the exercise stress test and not the pharmacological stress test the chosen method was recorded. No relationship was demonstrated between the time MIBI remained in a syringe prior to injection and residual activity. Residual activity was not affected by method of stress test used. Actual injected activity can be calculated if the amount of activity remaining in the syringe post injection is known. Imaging time can be adjusted for residual activity to optimise count statistics. Preliminary results in this study indicate there is no difference in residual activity between syringe brands.Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  6. Nuclear accident dosimetry: the calibration of Geiger-Mueller and 2π proportional counters for sulphur and gold

    International Nuclear Information System (INIS)

    Delafield, H.J.; Reading, A.H.

    1981-10-01

    A reference, 2π precision counter was set up at Harwell and absolutely calibrated for the measurement of sulphur discs ( 32 P) and gold foils ( 198 Au) used in the UK personnel criticality dosimeter. Sample sulphur discs and gold foils were irradiated in the GLEEP reactor at Harwell, counted in the 2π counter, and their activities absolutely assayed by the National Physical Laboratory. The 2π counter was then used to intercalibrate the GM counters used routinely for the assessment of the criticality dosimeter. The mean measured efficiencies of the GM counters were found to be for 32 P in sulphur discs within +- 4%, and for gold ( 198 Au) within +- 6% of the values given by previous calibrations. (author)

  7. Modal Logics with Counting

    Science.gov (United States)

    Areces, Carlos; Hoffmann, Guillaume; Denis, Alexandre

    We present a modal language that includes explicit operators to count the number of elements that a model might include in the extension of a formula, and we discuss how this logic has been previously investigated under different guises. We show that the language is related to graded modalities and to hybrid logics. We illustrate a possible application of the language to the treatment of plural objects and queries in natural language. We investigate the expressive power of this logic via bisimulations, discuss the complexity of its satisfiability problem, define a new reasoning task that retrieves the cardinality bound of the extension of a given input formula, and provide an algorithm to solve it.

  8. Digital coincidence counting

    International Nuclear Information System (INIS)

    Buckman, S.M.; Ius, D.

    1996-01-01

    This paper reports on the development of a digital coincidence-counting system which comprises a custom-built data acquisition card and associated PC software. The system has been designed to digitise the pulse-trains from two radiation detectors at a rate of 20 MSamples/s with 12-bit resolution. Through hardware compression of the data, the system can continuously record both individual pulse-shapes and the time intervals between pulses. Software-based circuits are used to process the stored pulse trains. These circuits are constructed simply by linking together icons representing various components such as coincidence mixers, time delays, single-channel analysers, deadtimes and scalers. This system enables a pair of pulse trains to be processed repeatedly using any number of different methods. Some preliminary results are presented in order to demonstrate the versatility and efficiency of this new method. (orig.)

  9. Digital coincidence counting

    Science.gov (United States)

    Buckman, S. M.; Ius, D.

    1996-02-01

    This paper reports on the development of a digital coincidence-counting system which comprises a custom-built data acquisition card and associated PC software. The system has been designed to digitise the pulse-trains from two radiation detectors at a rate of 20 MSamples/s with 12-bit resolution. Through hardware compression of the data, the system can continuously record both individual pulse-shapes and the time intervals between pulses. Software-based circuits are used to process the stored pulse trains. These circuits are constructed simply by linking together icons representing various components such as coincidence mixers, time delays, single-channel analysers, deadtimes and scalers. This system enables a pair of pulse trains to be processed repeatedly using any number of different methods. Some preliminary results are presented in order to demonstrate the versatility and efficiency of this new method.

  10. Range walk error correction and modeling on Pseudo-random photon counting system

    Science.gov (United States)

    Shen, Shanshan; Chen, Qian; He, Weiji

    2017-08-01

    Signal to noise ratio and depth accuracy are modeled for the pseudo-random ranging system with two random processes. The theoretical results, developed herein, capture the effects of code length and signal energy fluctuation are shown to agree with Monte Carlo simulation measurements. First, the SNR is developed as a function of the code length. Using Geiger-mode avalanche photodiodes (GMAPDs), longer code length is proven to reduce the noise effect and improve SNR. Second, the Cramer-Rao lower bound on range accuracy is derived to justify that longer code length can bring better range accuracy. Combined with the SNR model and CRLB model, it is manifested that the range accuracy can be improved by increasing the code length to reduce the noise-induced error. Third, the Cramer-Rao lower bound on range accuracy is shown to converge to the previously published theories and introduce the Gauss range walk model to range accuracy. Experimental tests also converge to the presented boundary model in this paper. It has been proven that depth error caused by the fluctuation of the number of detected photon counts in the laser echo pulse leads to the depth drift of Time Point Spread Function (TPSF). Finally, numerical fitting function is used to determine the relationship between the depth error and the photon counting ratio. Depth error due to different echo energy is calibrated so that the corrected depth accuracy is improved to 1cm.

  11. Photon-counting monolithic avalanche photodiode arrays for the super collider

    International Nuclear Information System (INIS)

    Ishaque, A.N.; Castleberry, D.E.; Rougeot, H.M.

    1994-01-01

    In fiber tracking, calorimetry, and other high energy and nuclear physics experiments, the need arises to detect an optical signal consisting of a few photons (in some cases a single photoelectron) with a detector insensitive to magnetic fields. Previous attempts to detect a single photoelectron have involved avalanche photodiodes (APDs) operated in the Geiger mode, the visible light photon counter, and a photomultiplier tube with an APD as the anode. In this paper it is demonstrated that silicon APDs, biased below the breakdown voltage, can be used to detect a signal of a few photons with conventional pulse counting circuitry at room temperature. Moderate cooling, it is further argued, could make it possible to detect a single photoelectron. Monolithic arrays of silicon avalanche photodiodes fabricated by Radiation Monitoring Devices, Inc. (RMD) were evaluated for possible use in the Super Collider detector systems. Measurements on 3 element x 3 element (2 mm pitch) APD arrays, using pulse counting circuitry with a charge sensitive amplifier (CSA) and a Gaussian filter, are reported and found to conform to a simple noise model. The model is used to obtain the optimal operating point. Experimental results are described in Section II, modeling results in Section III, and the conclusions are summarized in Section IV

  12. Counting statistics in low level radioactivity measurements fluctuating counting efficiency

    International Nuclear Information System (INIS)

    Pazdur, M.F.

    1976-01-01

    A divergence between the probability distribution of the number of nuclear disintegrations and the number of observed counts, caused by counting efficiency fluctuation, is discussed. The negative binominal distribution is proposed to describe the probability distribution of the number of counts, instead of Poisson distribution, which is assumed to hold for the number of nuclear disintegrations only. From actual measurements the r.m.s. amplitude of counting efficiency fluctuation is estimated. Some consequences of counting efficiency fluctuation are investigated and the corresponding formulae are derived: (1) for detection limit as a function of the number of partial measurements and the relative amplitude of counting efficiency fluctuation, and (2) for optimum allocation of the number of partial measurements between sample and background. (author)

  13. Let's Make Data Count

    Science.gov (United States)

    Budden, A. E.; Abrams, S.; Chodacki, J.; Cruse, P.; Fenner, M.; Jones, M. B.; Lowenberg, D.; Rueda, L.; Vieglais, D.

    2017-12-01

    The impact of research has traditionally been measured by citations to journal publications and used extensively for evaluation and assessment in academia, but this process misses the impact and reach of data and software as first-class scientific products. For traditional publications, Article-Level Metrics (ALM) capture the multitude of ways in which research is disseminated and used, such as references and citations within social media and other journal articles. Here we present on the extension of usage and citation metrics collection to include other artifacts of research, namely datasets. The Make Data Count (MDC) project will enable measuring the impact of research data in a manner similar to what is currently done with publications. Data-level metrics (DLM) are a multidimensional suite of indicators measuring the broad reach and use of data as legitimate research outputs. By making data metrics openly available for reuse in a number of different ways, the MDC project represents an important first step on the path towards the full integration of data metrics into the research data management ecosystem. By assuring researchers that their contributions to scholarly progress represented by data corpora are acknowledged, data level metrics provide a foundation for streamlining the advancement of knowledge by actively promoting desirable best practices regarding research data management, publication, and sharing.

  14. LAWRENCE RADIATION LABORATORY COUNTING HANDBOOK

    Energy Technology Data Exchange (ETDEWEB)

    Group, Nuclear Instrumentation

    1966-10-01

    The Counting Handbook is a compilation of operational techniques and performance specifications on counting equipment in use at the Lawrence Radiation Laboratory, Berkeley. Counting notes have been written from the viewpoint of the user rather than that of the designer or maintenance man. The only maintenance instructions that have been included are those that can easily be performed by the experimenter to assure that the equipment is operating properly.

  15. SUMS Counts-Related Projects

    Data.gov (United States)

    Social Security Administration — Staging Instance for all SUMs Counts related projects including: Redeterminations/Limited Issue, Continuing Disability Resolution, CDR Performance Measures, Initial...

  16. Compton suppression gamma-counting: The effect of count rate

    Science.gov (United States)

    Millard, H.T.

    1984-01-01

    Past research has shown that anti-coincidence shielded Ge(Li) spectrometers enhanced the signal-to-background ratios for gamma-photopeaks, which are situated on high Compton backgrounds. Ordinarily, an anti- or non-coincidence spectrum (A) and a coincidence spectrum (C) are collected simultaneously with these systems. To be useful in neutron activation analysis (NAA), the fractions of the photopeak counts routed to the two spectra must be constant from sample to sample to variations must be corrected quantitatively. Most Compton suppression counting has been done at low count rate, but in NAA applications, count rates may be much higher. To operate over the wider dynamic range, the effect of count rate on the ratio of the photopeak counts in the two spectra (A/C) was studied. It was found that as the count rate increases, A/C decreases for gammas not coincident with other gammas from the same decay. For gammas coincident with other gammas, A/C increases to a maximum and then decreases. These results suggest that calibration curves are required to correct photopeak areas so quantitative data can be obtained at higher count rates. ?? 1984.

  17. Comparative Study on the Adaptation and Growth Dynamics of the Helix pomatia and Helix aspersa Muller Terrestrial Snails Under Different Feeding Regimes

    Directory of Open Access Journals (Sweden)

    Adrian Toader-Williams

    2010-05-01

    Full Text Available We used Helix pomatia and Helix aspersa species and measure their growth as the snails were approaching the hibernation season. Helix pomatia 2yo shown a decrease in weight while being raised in enclosed parcels of 4sqm the younger Helix pomatia 1yo as well as Helix aspersa Muller demonstrated the ability to adapt relatively fast to the same conditions. We established 5 experimental lots in a Helix pomatia farm, GPS coordinates N46.606040 E23.599950. Control lot contained Taraxacum officinales, Sonchus oleraceus, Equisetum arvense and Atriplex hortensis, wild flora found within the farm. The other lots contained the same plants as the control lot plus different combinations of imported plants from other areals. The H. pomatia 2yo weight decreased in the control lot by a mean of -3.86% while H. aspersa 1yo marked an increase of +16.89% in the same lot during the same period. The lot containing lupinus polyphyllus delivered snails with weight gain of +24.66% for H. pomatia 2yo and an increase of only +1.98% for H. aspersa 1yo. As a contrast, H. pomatia 2yo gained only +7.72% while H. aspersa 1yo gained +28.89%, in the lot containing Lavanda officinalis, Foeniculum vulgare and Hyssopus officinalis among the other plants.

  18. Track counting in radon dosimetry

    International Nuclear Information System (INIS)

    Fesenbeck, Ingo; Koehler, Bernd; Reichert, Klaus-Martin

    2013-01-01

    The newly developed, computer-controlled track counting system is capable of imaging and analyzing the entire area of nuclear track detectors. The high optical resolution allows a new analysis approach for the process of automated counting using digital image processing technologies. This way, higher exposed detectors can be evaluated reliably by an automated process as well. (orig.)

  19. Galaxy number counts: Pt. 2

    International Nuclear Information System (INIS)

    Metcalfe, N.; Shanks, T.; Fong, R.; Jones, L.R.

    1991-01-01

    Using the Prime Focus CCD Camera at the Isaac Newton Telescope we have determined the form of the B and R galaxy number-magnitude count relations in 12 independent fields for 21 m ccd m and 19 m ccd m 5. The average galaxy count relations lie in the middle of the wide range previously encompassed by photographic data. The field-to-field variation of the counts is small enough to define the faint (B m 5) galaxy count to ±10 per cent and this variation is consistent with that expected from galaxy clustering considerations. Our new data confirm that the B, and also the R, galaxy counts show evidence for strong galaxy luminosity evolution, and that the majority of the evolving galaxies are of moderately blue colour. (author)

  20. Hanford whole body counting manual

    International Nuclear Information System (INIS)

    Palmer, H.E.; Brim, C.P.; Rieksts, G.A.; Rhoads, M.C.

    1987-05-01

    This document, a reprint of the Whole Body Counting Manual, was compiled to train personnel, document operation procedures, and outline quality assurance procedures. The current manual contains information on: the location, availability, and scope of services of Hanford's whole body counting facilities; the administrative aspect of the whole body counting operation; Hanford's whole body counting facilities; the step-by-step procedure involved in the different types of in vivo measurements; the detectors, preamplifiers and amplifiers, and spectroscopy equipment; the quality assurance aspect of equipment calibration and recordkeeping; data processing, record storage, results verification, report preparation, count summaries, and unit cost accounting; and the topics of minimum detectable amount and measurement accuracy and precision. 12 refs., 13 tabs

  1. A new approach to beta-gamma coincidence counting. Advance report on the Samar electronic system; Informe preliminar del sistema Samar sistema automatico de medidas absolutas de Radionucleidos

    Energy Technology Data Exchange (ETDEWEB)

    Carlos, J E. de; Granados, C E

    1972-07-01

    In 4{pi} {beta}-{gamma} coincidence measurements, precision on the evaluation of coincidence counting losses is made difficult because of complex overlapping effects between the{beta}--and {gamma}-side dead times due to pre cursive counted events. In this context the SAMAR electronic system is aimed to give a precise way of automatic counting and reduce the need for calculated corrections. This report describes its configuration and basic features. The SAMAR has been conceived in such a manner that both beta and gamma chains are sharing a common and non extending dead-time which is simultaneously applied to both channels. The shared dead time is made to be the only one inserted throughout the chains. Overlapping effects vanish and the three counting channels have identical transmission ratios. A new dead-time circuit based on fast linear gates as blocking elements has been developed. Application of the two-oscillator Muller's method evidences a fully non-extending character. Automatism is implemented by using a live timer corrective channel controlling the counting scalers. (Author) 21 refs.

  2. A new approach to beta-gamma coincidence counting. Advance report on the Samar electronic system; Informe preliminar del sistema Samar sistema automatico de medidas absolutas de Radionucleidos

    Energy Technology Data Exchange (ETDEWEB)

    Carlos, J. E. de; Granados, C. E.

    1972-07-01

    In 4{pi} {beta}-{gamma} coincidence measurements, precision on the evaluation of coincidence counting losses is made difficult because of complex overlapping effects between the{beta}--and {gamma}-side dead times due to pre cursive counted events. In this context the SAMAR electronic system is aimed to give a precise way of automatic counting and reduce the need for calculated corrections. This report describes its configuration and basic features. The SAMAR has been conceived in such a manner that both beta and gamma chains are sharing a common and non extending dead-time which is simultaneously applied to both channels. The shared dead time is made to be the only one inserted throughout the chains. Overlapping effects vanish and the three counting channels have identical transmission ratios. A new dead-time circuit based on fast linear gates as blocking elements has been developed. Application of the two-oscillator Muller's method evidences a fully non-extending character. Automatism is implemented by using a live timer corrective channel controlling the counting scalers. (Author) 21 refs.

  3. In vivo counting of uranium

    International Nuclear Information System (INIS)

    Palmer, H.E.

    1985-03-01

    A state-of-the-art radiation detector system consisting of six individually mounted intrinsic germanium planar detectors, each 20 cm 2 by 13 mm thick, mounted together such that the angle of the whole system can be changed to match the slope of the chest of the person being counted, is described. The sensitivity of the system for counting uranium and plutonium in vivo and the precedures used in calibrating the system are also described. Some results of counts done on uranium mill workers are presented. 15 figs., 2 tabs

  4. Portable counter for geological research

    Energy Technology Data Exchange (ETDEWEB)

    Russell, O J

    1949-05-01

    A portable counter which has been developed for prospecting for radio-active uranium and thorium minerals, for general geological investigations, and as an ultra-sensitive detector of lost or mislaid radium, is described. The aforementioned general usage includes the identification of changes in strata by means of the investigation of the slight amount of residual activity pressent in most minerals. The apparatus, which consists essentially of a scaled-down version of a standard laboratory Geiger-Muller counter, is highly sensitive since a variation equivalent to 4% of the cosmic ray background can be detected by a three-minute count.

  5. Characterization and determination of efficiency of GM detectors for KCl standards

    International Nuclear Information System (INIS)

    Priyal, M.R.; Thilagam, L.; Mohapatra, D.K.

    2018-01-01

    Characterization of Geiger Muller (GM) based beta counters are carried out to determine the main parameters such as plateau slope and efficiency for various slit locations 1 to 10, that are available to keep the sources at different distances away from the detector. Additionally, the disc shaped potassium chloride (KCl) beta standards of various 40 K activities are prepared with variable mass and estimated for the efficiencies of GM tube detectors. The activity of 40K, the counts per second and the efficiency of GM tubes are studied as a function of mass of KCl standards

  6. Evaluation of Accessory Lacrimal Gland in Muller's Muscle Conjunctival Resection Specimens for Precursor Cell Markers and Biological Markers of Dry Eye Disease.

    Science.gov (United States)

    Ali, Marwan; Shah, Dhara; Pasha, Zeeshan; Jassim, Sarmad H; Jassim Jaboori, Assraa; Setabutr, Pete; Aakalu, Vinay K

    2017-04-01

    The accessory lacrimal glands (ALGs) are an understudied component of the tear functional unit, even though they are important in the development of dry eye syndrome (DES). To advance our understanding of aging changes, regenerative potential, and histologic correlates to human characteristics, we investigated human ALG tissue from surgical samples to determine the presence or absence of progenitor cell markers and lacrimal epithelial markers and to correlate marker expression to relevant patient characteristics. ALG tissues obtained from Muller's muscle conjunctival resection (MMCR) specimens were created using tissue microarrays (TMAs). Immunofluorescence staining of MMCR sections was performed using primary antibodies specific to cell protein markers. Cell marker localization in TMAs was then assessed by two blinded observers using a standardized scoring system. Patient characteristics including age, race, and status of ocular surface health were then compared against expression of stem cell markers. Human ALG expressed a number of epithelial markers, and in particular, histatin-1 was well correlated with the expression of epithelial markers and was present in most acini. In addition, we noted the presence of precursor cell markers nestin, ABCG2, and CD90 in ALG tissue. There was a decrease in precursor cell marker expression with increasing age. Finally, we noted that a negative association was present between histatin-1 expression and DES. Thus, we report for the first time that human ALG tissues contain precursor marker-positive cells and that this marker expression may decrease with increasing age. Moreover, histatin-1 expression may be decreased in DES. Future studies will be performed to use these cell markers to isolate and culture lacrimal epithelial cells from heterogeneous tissues, determine the relevance of histatin-1 expression to DES, and isolate candidate precursor cells from ALG tissue.

  7. Complete Blood Count (For Parents)

    Science.gov (United States)

    ... Kids Deal With Injections and Blood Tests Blood Culture Anemia Blood Test: Basic Metabolic Panel (BMP) Blood Test: Hemoglobin Basic Blood Chemistry Tests Word! Complete Blood Count (CBC) Medical Tests and Procedures ( ...

  8. Make My Trip Count 2015

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Make My Trip Count (MMTC) commuter survey, conducted in September and October 2015 by GBA, the Pittsburgh 2030 District, and 10 other regional transportation...

  9. Counting Triangles to Sum Squares

    Science.gov (United States)

    DeMaio, Joe

    2012-01-01

    Counting complete subgraphs of three vertices in complete graphs, yields combinatorial arguments for identities for sums of squares of integers, odd integers, even integers and sums of the triangular numbers.

  10. Counting Word Frequencies with Python

    Directory of Open Access Journals (Sweden)

    William J. Turkel

    2012-07-01

    Full Text Available Your list is now clean enough that you can begin analyzing its contents in meaningful ways. Counting the frequency of specific words in the list can provide illustrative data. Python has an easy way to count frequencies, but it requires the use of a new type of variable: the dictionary. Before you begin working with a dictionary, consider the processes used to calculate frequencies in a list.

  11. Liquid scintillation counting of chlorophyll

    International Nuclear Information System (INIS)

    Fric, F.; Horickova, B.; Haspel-Horvatovic, E.

    1975-01-01

    A precise and reproducible method of liquid scintillation counting was worked out for measuring the radioactivity of 14 C-labelled chlorophyll a and chlorophyll b solutions without previous bleaching. The spurious count rate caused by luminescence of the scintillant-chlorophyll system is eliminated by using a suitable scintillant and by measuring the radioactivity at 4 to 8 0 C after an appropriate time of dark adaptation. Bleaching of the chlorophyll solutions is necessary only for measuring of very low radioactivity. (author)

  12. Standardization of 241Am by digital coincidence counting, liquid scintillation counting and defined solid angle counting

    International Nuclear Information System (INIS)

    Balpardo, C.; Capoulat, M.E.; Rodrigues, D.; Arenillas, P.

    2010-01-01

    The nuclide 241 Am decays by alpha emission to 237 Np. Most of the decays (84.6%) populate the excited level of 237 Np with energy of 59.54 keV. Digital coincidence counting was applied to standardize a solution of 241 Am by alpha-gamma coincidence counting with efficiency extrapolation. Electronic discrimination was implemented with a pressurized proportional counter and the results were compared with two other independent techniques: Liquid scintillation counting using the logical sum of double coincidences in a TDCR array and defined solid angle counting taking into account activity inhomogeneity in the active deposit. The results show consistency between the three methods within a limit of a 0.3%. An ampoule of this solution will be sent to the International Reference System (SIR) during 2009. Uncertainties were analysed and compared in detail for the three applied methods.

  13. Hanford whole body counting manual

    International Nuclear Information System (INIS)

    Palmer, H.E.; Rieksts, G.A.; Lynch, T.P.

    1990-06-01

    This document describes the Hanford Whole Body Counting Program as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy--Richland Operations Office (DOE-RL) and its Hanford contractors. Program services include providing in vivo measurements of internally deposited radioactivity in Hanford employees (or visitors). Specific chapters of this manual deal with the following subjects: program operational charter, authority, administration, and practices, including interpreting applicable DOE Orders, regulations, and guidance into criteria for in vivo measurement frequency, etc., for the plant-wide whole body counting services; state-of-the-art facilities and equipment used to provide the best in vivo measurement results possible for the approximately 11,000 measurements made annually; procedures for performing the various in vivo measurements at the Whole Body Counter (WBC) and related facilities including whole body counts; operation and maintenance of counting equipment, quality assurance provisions of the program, WBC data processing functions, statistical aspects of in vivo measurements, and whole body counting records and associated guidance documents. 16 refs., 48 figs., 22 tabs

  14. Temporal trends in sperm count

    DEFF Research Database (Denmark)

    Levine, Hagai; Jørgensen, Niels; Martino-Andrade, Anderson

    2017-01-01

    a predefined protocol 7518 abstracts were screened and 2510 full articles reporting primary data on SC were reviewed. A total of 244 estimates of SC and TSC from 185 studies of 42 935 men who provided semen samples in 1973-2011 were extracted for meta-regression analysis, as well as information on years.......006, respectively). WIDER IMPLICATIONS: This comprehensive meta-regression analysis reports a significant decline in sperm counts (as measured by SC and TSC) between 1973 and 2011, driven by a 50-60% decline among men unselected by fertility from North America, Europe, Australia and New Zealand. Because......BACKGROUND: Reported declines in sperm counts remain controversial today and recent trends are unknown. A definitive meta-analysis is critical given the predictive value of sperm count for fertility, morbidity and mortality. OBJECTIVE AND RATIONALE: To provide a systematic review and meta-regression...

  15. Photon-counting image sensors

    CERN Document Server

    Teranishi, Nobukazu; Theuwissen, Albert; Stoppa, David; Charbon, Edoardo

    2017-01-01

    The field of photon-counting image sensors is advancing rapidly with the development of various solid-state image sensor technologies including single photon avalanche detectors (SPADs) and deep-sub-electron read noise CMOS image sensor pixels. This foundational platform technology will enable opportunities for new imaging modalities and instrumentation for science and industry, as well as new consumer applications. Papers discussing various photon-counting image sensor technologies and selected new applications are presented in this all-invited Special Issue.

  16. Liquid scintillation, counting, and compositions

    International Nuclear Information System (INIS)

    Sena, E.A.; Tolbert, B.M.; Sutula, C.L.

    1975-01-01

    The emissions of radioactive isotopes in both aqueous and organic samples can be measured by liquid scintillation counting in micellar systems. The micellar systems are made up of scintillation solvent, scintillation solute and a mixture of surfactants, preferably at least one of which is relatively oil-soluble water-insoluble and another which is relatively water-soluble oil-insoluble

  17. Phase space quark counting rule

    International Nuclear Information System (INIS)

    Wei-gin, C.; Lo, S.

    1980-01-01

    A simple quark counting rule based on phase space consideration suggested before is used to fit all 39 recent experimental data points on inclusive reactions. Parameter free relations are found to agree with experiments. Excellent detail fits are obtained for 11 inclusive reactions

  18. Counting a Culture of Mealworms

    Science.gov (United States)

    Ashbrook, Peggy

    2007-01-01

    Math is not the only topic that will be discussed when young children are asked to care for and count "mealworms," a type of insect larvae (just as caterpillars are the babies of butterflies, these larvae are babies of beetles). The following activity can take place over two months as the beetles undergo metamorphosis from larvae to adults. As the…

  19. Counting problems for number rings

    NARCIS (Netherlands)

    Brakenhoff, Johannes Franciscus

    2009-01-01

    In this thesis we look at three counting problems connected to orders in number fields. First we study the probability that for a random polynomial f in Z[X] the ring Z[X]/f is the maximal order in Q[X]/f. Connected to this is the probability that a random polynomial has a squarefree

  20. On Counting the Rational Numbers

    Science.gov (United States)

    Almada, Carlos

    2010-01-01

    In this study, we show how to construct a function from the set N of natural numbers that explicitly counts the set Q[superscript +] of all positive rational numbers using a very intuitive approach. The function has the appeal of Cantor's function and it has the advantage that any high school student can understand the main idea at a glance…

  1. Logistic regression for dichotomized counts.

    Science.gov (United States)

    Preisser, John S; Das, Kalyan; Benecha, Habtamu; Stamm, John W

    2016-12-01

    Sometimes there is interest in a dichotomized outcome indicating whether a count variable is positive or zero. Under this scenario, the application of ordinary logistic regression may result in efficiency loss, which is quantifiable under an assumed model for the counts. In such situations, a shared-parameter hurdle model is investigated for more efficient estimation of regression parameters relating to overall effects of covariates on the dichotomous outcome, while handling count data with many zeroes. One model part provides a logistic regression containing marginal log odds ratio effects of primary interest, while an ancillary model part describes the mean count of a Poisson or negative binomial process in terms of nuisance regression parameters. Asymptotic efficiency of the logistic model parameter estimators of the two-part models is evaluated with respect to ordinary logistic regression. Simulations are used to assess the properties of the models with respect to power and Type I error, the latter investigated under both misspecified and correctly specified models. The methods are applied to data from a randomized clinical trial of three toothpaste formulations to prevent incident dental caries in a large population of Scottish schoolchildren. © The Author(s) 2014.

  2. Vote Counting as Mathematical Proof

    DEFF Research Database (Denmark)

    Schürmann, Carsten; Pattinson, Dirk

    2015-01-01

    then consists of a sequence (or tree) of rule applications and provides an independently checkable certificate of the validity of the result. This reduces the need to trust, or otherwise verify, the correctness of the vote counting software once the certificate has been validated. Using a rule...

  3. Counting SET-free sets

    OpenAIRE

    Harman, Nate

    2016-01-01

    We consider the following counting problem related to the card game SET: How many $k$-element SET-free sets are there in an $n$-dimensional SET deck? Through a series of algebraic reformulations and reinterpretations, we show the answer to this question satisfies two polynomiality conditions.

  4. Repeatability of differential goat bulk milk culture and associations with somatic cell count, total bacterial count, and standard plate count

    OpenAIRE

    Koop, G.; Dik, N.; Nielen, M.; Lipman, L.J.A.

    2010-01-01

    The aims of this study were to assess how different bacterial groups in bulk milk are related to bulk milk somatic cell count (SCC), bulk milk total bacterial count (TBC), and bulk milk standard plate count (SPC) and to measure the repeatability of bulk milk culturing. On 53 Dutch dairy goat farms, 3 bulk milk samples were collected at intervals of 2 wk. The samples were cultured for SPC, coliform count, and staphylococcal count and for the presence of Staphylococcus aureus. Furthermore, SCC ...

  5. Theory of photoelectron counting statistics

    International Nuclear Information System (INIS)

    Blake, J.

    1980-01-01

    The purpose of the present essay is to provide a detailed analysis of those theoretical aspects of photoelectron counting which are capable of experimental verification. Most of our interest is in the physical phenomena themselves, while part is in the mathematical techniques. Many of the mathematical methods used in the analysis of the photoelectron counting problem are generally unfamiliar to physicists interested in the subject. For this reason we have developed the essay in such a fashion that, although primary interest is focused on the physical phenomena, we have also taken pains to carry out enough of the analysis so that the reader can follow the main details. We have chosen to present a consistently quantum mechanical version of the subject, in that we follow the Glauber theory throughout. (orig./WL)

  6. Bayesian Kernel Mixtures for Counts.

    Science.gov (United States)

    Canale, Antonio; Dunson, David B

    2011-12-01

    Although Bayesian nonparametric mixture models for continuous data are well developed, there is a limited literature on related approaches for count data. A common strategy is to use a mixture of Poissons, which unfortunately is quite restrictive in not accounting for distributions having variance less than the mean. Other approaches include mixing multinomials, which requires finite support, and using a Dirichlet process prior with a Poisson base measure, which does not allow smooth deviations from the Poisson. As a broad class of alternative models, we propose to use nonparametric mixtures of rounded continuous kernels. An efficient Gibbs sampler is developed for posterior computation, and a simulation study is performed to assess performance. Focusing on the rounded Gaussian case, we generalize the modeling framework to account for multivariate count data, joint modeling with continuous and categorical variables, and other complications. The methods are illustrated through applications to a developmental toxicity study and marketing data. This article has supplementary material online.

  7. Card counting in continuous time

    OpenAIRE

    Andersson, Patrik

    2012-01-01

    We consider the problem of finding an optimal betting strategy for a house-banked casino card game that is played for several coups before reshuffling. The sampling without replacement makes it possible to take advantage of the changes in the expected value as the deck is depleted, making large bets when the game is advantageous. Using such a strategy, which is easy to implement, is known as card counting. We consider the case of a large number of decks, making an approximat...

  8. Monitoring Milk Somatic Cell Counts

    Directory of Open Access Journals (Sweden)

    Gheorghe Şteţca

    2014-11-01

    Full Text Available The presence of somatic cells in milk is a widely disputed issue in milk production sector. The somatic cell counts in raw milk are a marker for the specific cow diseases such as mastitis or swollen udder. The high level of somatic cells causes physical and chemical changes to milk composition and nutritional value, and as well to milk products. Also, the mastitic milk is not proper for human consumption due to its contribution to spreading of certain diseases and food poisoning. According to these effects, EU Regulations established the maximum threshold of admitted somatic cells in raw milk to 400000 cells / mL starting with 2014. The purpose of this study was carried out in order to examine the raw milk samples provided from small farms, industrial type farms and milk processing units. There are several ways to count somatic cells in milk but the reference accepted method is the microscopic method described by the SR EN ISO 13366-1/2008. Generally samples registered values in accordance with the admissible limit. By periodical monitoring of the somatic cell count, certain technological process issues are being avoided and consumer’s health ensured.

  9. Repeatability of differential goat bulk milk culture and associations with somatic cell count, total bacterial count, and standard plate count

    NARCIS (Netherlands)

    Koop, G.; Dik, N.; Nielen, M.; Lipman, L.J.A.

    2010-01-01

    The aims of this study were to assess how different bacterial groups in bulk milk are related to bulk milk somatic cell count (SCC), bulk milk total bacterial count (TBC), and bulk milk standard plate count (SPC) and to measure the repeatability of bulk milk culturing. On 53 Dutch dairy goat farms,

  10. Nearest neighbors by neighborhood counting.

    Science.gov (United States)

    Wang, Hui

    2006-06-01

    Finding nearest neighbors is a general idea that underlies many artificial intelligence tasks, including machine learning, data mining, natural language understanding, and information retrieval. This idea is explicitly used in the k-nearest neighbors algorithm (kNN), a popular classification method. In this paper, this idea is adopted in the development of a general methodology, neighborhood counting, for devising similarity functions. We turn our focus from neighbors to neighborhoods, a region in the data space covering the data point in question. To measure the similarity between two data points, we consider all neighborhoods that cover both data points. We propose to use the number of such neighborhoods as a measure of similarity. Neighborhood can be defined for different types of data in different ways. Here, we consider one definition of neighborhood for multivariate data and derive a formula for such similarity, called neighborhood counting measure or NCM. NCM was tested experimentally in the framework of kNN. Experiments show that NCM is generally comparable to VDM and its variants, the state-of-the-art distance functions for multivariate data, and, at the same time, is consistently better for relatively large k values. Additionally, NCM consistently outperforms HEOM (a mixture of Euclidean and Hamming distances), the "standard" and most widely used distance function for multivariate data. NCM has a computational complexity in the same order as the standard Euclidean distance function and NCM is task independent and works for numerical and categorical data in a conceptually uniform way. The neighborhood counting methodology is proven sound for multivariate data experimentally. We hope it will work for other types of data.

  11. CalCOFI Egg Counts Positive Tows

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish egg counts and standardized counts for eggs captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets], and...

  12. CalCOFI Larvae Counts Positive Tows

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for eggs captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  13. Alaska Steller Sea Lion Pup Count Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This database contains counts of Steller sea lion pups on rookeries in Alaska made between 1961 and 2015. Pup counts are conducted in late June-July. Pups are...

  14. Demountable 4 {pi} Geiger Counters for Standardization and the Assay of Low-Activity Samples; Compteurs 4 {pi} GM demontables pour l'etalonnage et l'essai d'echantillons de faible activite; S'emnye schetchiki Gejgera na 4 {pi} dlya standartizatsii i otsenki prob nizkoj aktivnosti; Condatores GM 4 {pi} para la normalizacion de patrones radiactivos con baja actividad

    Energy Technology Data Exchange (ETDEWEB)

    Trott, N G; Bentley, R E; Burton, L K [Physics Department, Institute of Cancer Research, Royal Cancer Hospital, London, S. W. 3 (United Kingdom)

    1960-06-15

    Some developments in the design of 4 {pi} GM counters are reported and applications of these counters in the measurements of radioactive standards, in relation to radiological work, are discussed. In the two types of 4 {pi} GM counter described the anode wires can be easily removed thereby facilitating cleaning. One type has been used successfully for several years in the standardization of {beta}-emitting radioactive nuclides and some results of intercomparison s of standards with other laboratories are presented. These counters have also been applied, in conjunction with a {gamma} ionization system, in determinations of the specific {gamma}-ray emission (k-factor) for Fe{sup 59}, Cs{sup 137} and Ir{sup 192}. The second type is a smaller low-background version of the above counter, constructed in stainless steel and designed primarily for the assay of small amounts of radioactivity in biological materials. It can also be adapted for the absolute measurement of radioactive sources at low counting rates {<=} 100 counts per minute) since, when shielded with cosmic-ray counters in anti-coincidence, a stable background of between 1 and 2 counts per minute can be obtained. (author) [French] Les auteurs decrivent certains perfectionnement s dans la construction de compteurs 4 {pi} GM et discutent les utilisations de ces compteurs pour la mesure d'etalons radioactifs, en relation avec les recherches radiologiques. Les filaments anodiques des deux types de compteurs 4 {pi} GM decrits peuvent etre facilement enleves, ce qui facilite le nettoyage. L'un des types a ete utilise avec succes durant plusieures annees pour l'etalonnage de nuclides {beta} actifs; les auteurs presentent les resultats des comparaisons d'etalons faites avec d'autres laboratoires. Ce type de compteur a ete egalement utilise pour la determination du facteur k (emission {gamma} specifique) de Fe{sup 59}, Cs{sup 137} et Ir{sup 182}. Le second type de compteurs est une version reduite, a faible mouvement

  15. SPERM COUNT DISTRIBUTIONS IN FERTILE MEN

    Science.gov (United States)

    Sperm concentration and count are often used as indicators of environmental impacts on male reproductive health. Existing clinical databases may be biased towards subfertile men with low sperm counts and less is known about expected sperm count distributions in cohorts of fertil...

  16. Platelet counting using the Coulter electronic counter.

    Science.gov (United States)

    Eggleton, M J; Sharp, A A

    1963-03-01

    A method for counting platelets in dilutions of platelet-rich plasm using the Coulter electronic counter is described.(1) The results obtained show that such platelet counts are at least as accurate as the best methods of visual counting. The various technical difficulties encountered are discussed.

  17. Count-doubling time safety circuit

    International Nuclear Information System (INIS)

    Keefe, D.J.; McDowell, W.P.; Rusch, G.K.

    1981-01-01

    There is provided a nuclear reactor count-factor-increase time monitoring circuit which includes a pulse-type neutron detector, and means for counting the number of detected pulses during specific time periods. Counts are compared and the comparison is utilized to develop a reactor scram signal, if necessary

  18. Count-doubling time safety circuit

    Science.gov (United States)

    Rusch, Gordon K.; Keefe, Donald J.; McDowell, William P.

    1981-01-01

    There is provided a nuclear reactor count-factor-increase time monitoring circuit which includes a pulse-type neutron detector, and means for counting the number of detected pulses during specific time periods. Counts are compared and the comparison is utilized to develop a reactor scram signal, if necessary.

  19. DC KIDS COUNT e-Databook Indicators

    Science.gov (United States)

    DC Action for Children, 2012

    2012-01-01

    This report presents indicators that are included in DC Action for Children's 2012 KIDS COUNT e-databook, their definitions and sources and the rationale for their selection. The indicators for DC KIDS COUNT represent a mix of traditional KIDS COUNT indicators of child well-being, such as the number of children living in poverty, and indicators of…

  20. How much do women count if they not counted?

    Directory of Open Access Journals (Sweden)

    Federica Taddia

    2006-01-01

    Full Text Available The condition of women throughout the world is marked by countless injustices and violations of the most fundamental rights established by the Universal Declaration of human rights and every culture is potentially prone to commit discrimination against women in various forms. Women are worse fed, more exposed to physical violence, more exposed to diseases and less educated; they have less access to, or are excluded from, vocational training paths; they are the most vulnerable among prisoners of conscience, refugees and immigrants and the least considered within ethnic minorities; from their very childhood, women are humiliated, undernourished, sold, raped and killed; their work is generally less paid compared to men’s work and in some countries they are victims of forced marriages. Such condition is the result of old traditions that implicit gender-differentiated education has long promoted through cultural models based on theories, practices and policies marked by discrimination and structured differentially for men and women. Within these cultural models, the basic educational institutions have played and still play a major role in perpetuating such traditions. Nevertheless, if we want to overcome inequalities and provide women with empowerment, we have to start right from the educational institutions and in particular from school, through the adoption of an intercultural approach to education: an approach based on active pedagogy and on methods of analysis, exchange and enhancement typical of socio-educational animation. The intercultural approach to education is attentive to promote the realisation of each individual and the dignity and right of everyone to express himself/herself in his/her own way. Such an approach will give women the opportunity to become actual agents of collective change and to get the strength and wellbeing necessary to count and be counted as human beings entitled to freedom and equality, and to have access to all

  1. Radon counting statistics - a Monte Carlo investigation

    International Nuclear Information System (INIS)

    Scott, A.G.

    1996-01-01

    Radioactive decay is a Poisson process, and so the Coefficient of Variation (COV) of open-quotes nclose quotes counts of a single nuclide is usually estimated as 1/√n. This is only true if the count duration is much shorter than the half-life of the nuclide. At longer count durations, the COV is smaller than the Poisson estimate. Most radon measurement methods count the alpha decays of 222 Rn, plus the progeny 218 Po and 214 Po, and estimate the 222 Rn activity from the sum of the counts. At long count durations, the chain decay of these nuclides means that every 222 Rn decay must be followed by two other alpha decays. The total number of decays is open-quotes 3Nclose quotes, where N is the number of radon decays, and the true COV of the radon concentration estimate is 1/√(N), √3 larger than the Poisson total count estimate of 1/√3N. Most count periods are comparable to the half lives of the progeny, so the relationship between COV and count time is complex. A Monte-Carlo estimate of the ratio of true COV to Poisson estimate was carried out for a range of count periods from 1 min to 16 h and three common radon measurement methods: liquid scintillation, scintillation cell, and electrostatic precipitation of progeny. The Poisson approximation underestimates COV by less than 20% for count durations of less than 60 min

  2. Discrete calculus methods for counting

    CERN Document Server

    Mariconda, Carlo

    2016-01-01

    This book provides an introduction to combinatorics, finite calculus, formal series, recurrences, and approximations of sums. Readers will find not only coverage of the basic elements of the subjects but also deep insights into a range of less common topics rarely considered within a single book, such as counting with occupancy constraints, a clear distinction between algebraic and analytical properties of formal power series, an introduction to discrete dynamical systems with a thorough description of Sarkovskii’s theorem, symbolic calculus, and a complete description of the Euler-Maclaurin formulas and their applications. Although several books touch on one or more of these aspects, precious few cover all of them. The authors, both pure mathematicians, have attempted to develop methods that will allow the student to formulate a given problem in a precise mathematical framework. The aim is to equip readers with a sound strategy for classifying and solving problems by pursuing a mathematically rigorous yet ...

  3. Counting paths with Schur transitions

    Energy Technology Data Exchange (ETDEWEB)

    Díaz, Pablo [Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta, T1K 3M4 (Canada); Kemp, Garreth [Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park 2006 (South Africa); Véliz-Osorio, Alvaro, E-mail: aveliz@gmail.com [Mandelstam Institute for Theoretical Physics, University of the Witwatersrand, WITS 2050, Johannesburg (South Africa); School of Physics and Astronomy, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)

    2016-10-15

    In this work we explore the structure of the branching graph of the unitary group using Schur transitions. We find that these transitions suggest a new combinatorial expression for counting paths in the branching graph. This formula, which is valid for any rank of the unitary group, reproduces known asymptotic results. We proceed to establish the general validity of this expression by a formal proof. The form of this equation strongly hints towards a quantum generalization. Thus, we introduce a notion of quantum relative dimension and subject it to the appropriate consistency tests. This new quantity finds its natural environment in the context of RCFTs and fractional statistics; where the already established notion of quantum dimension has proven to be of great physical importance.

  4. Mass counting of radioactivity samples

    International Nuclear Information System (INIS)

    Oesterlin, D.L.; Obrycki, R.F.

    1977-01-01

    A method and apparatus for concurrently counting a plurality of radioactive samples is claimed. The position sensitive circuitry of a scintillation camera is employed to sort electrical pulses resulting from scintillations according to the geometrical locations of scintillations causing those pulses. A scintillation means, in the form of a scintillating crystal material or a liquid scintillator, is positioned proximate to an array of radioactive samples. Improvement in the accuracy of pulse classification may be obtained by employing collimating means. If a plurality of scintillation crystals are employed to measure the iodine-125 content of samples, a method and means are provided for correcting for variations in crystal light transmission properties, sample volume, and sample container radiation absorption. 2 claims, 7 drawing figures

  5. Equipment used in nuclear medicine

    International Nuclear Information System (INIS)

    Das, B.K.; Noreen Norfaraheen Lee Abdullah

    2012-01-01

    Detection of radiation is the common purpose of all equipment's and instruments used in radioisotope laboratories. The first and most important instrument that was used in nuclear medicine was Geiger tube developed by H.W. Geiger as early in 1908. He in association with Mueller developed the so called Geiger-Muller tube (GM tube) which could be used to detect beta and gamma radiations. In spite of its severe limitations, GM tube remained the only external counting device until 1949. In 1948, Kallman reported that the scintillations can be detected and amplified with the help of photomultiplier tubes (PMTs). In comparison with gas filled detectors, scintillation detectors have two principal advantages that augment their use in nuclear medicine. Firstly, they are capable of much higher counting rates because of fast resolving times and secondly, because they are much more efficient for gamma ray detection. The scintillation detector is the most basic block of any modern radioisotope detection instrument like rate meter, counter, scanner, gamma camera or single photon emission computed tomography. (author)

  6. Counting Zero: Rethinking Feminist Epistemologies

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2017-10-01

    Full Text Available This article concerns feminist engagements with epistemologies. Feminist epistemologies have revealed and challenged the exclusions and denigrations at work in knowledge production processes. And yet, the emphasis on the partiality of knowledge and the non-innocence of any subject position also cast doubt on the possibility of feminist political communities. In view of this, it has been argued that the very parameter of epistemology poses limitations for feminism, for it leads to either political paralysis or prescriptive politics that in fact undoes the political of politics. From a different perspective, decolonial feminists argue for radical epistemic disobedience and delinking the move beyond the confines of Western systems of knowledge and its extractive knowledge economy. Nevertheless, the oppositional logic informs both feminist epistemologies and its critiques, which I argue is symptomatic of the epistemic habits of academic feminism. This article ends with a preliminary reconsideration of the question of origin through the figure of zero. It asks whether it might be possible to conceive of feminist epistemologies as performing the task of counting zero – accounting for origin, wholeness, and universality – that takes into account specificities without forfeiting coalition and claims to knowledge.

  7. Heterogeneous counting on filter support media

    International Nuclear Information System (INIS)

    Long, E.; Kohler, V.; Kelly, M.J.

    1976-01-01

    Many investigators in the biomedical research area have used filter paper as the support for radioactive samples. This means that a heterogeneous counting of sample sometimes results. The count rate of a sample on a filter will be affected by positioning, degree of dryness, sample application procedure, the type of filter, and the type of cocktail used. Positioning of the filter (up or down) in the counting vial can cause a variation of 35% or more when counting tritiated samples on filter paper. Samples of varying degrees of dryness when added to the counting cocktail can cause nonreproducible counts if handled improperly. Count rates starting at 2400 CPM initially can become 10,000 CPM in 24 hours for 3 H-DNA (deoxyribonucleic acid) samples dried on standard cellulose acetate membrane filters. Data on cellulose nitrate filters show a similar trend. Sample application procedures in which the sample is applied to the filter in a small spot or on a large amount of the surface area can cause nonreproducible or very low counting rates. A tritiated DNA sample, when applied topically, gives a count rate of 4,000 CPM. When the sample is spread over the whole filter, 13,400 CPM are obtained with a much better coefficient of variation (5% versus 20%). Adding protein carrier (bovine serum albumin-BSA) to the sample to trap more of the tritiated DNA on the filter during the filtration process causes a serious beta absorption problem. Count rates which are one-fourth the count rate applied to the filter are obtained on calibrated runs. Many of the problems encountered can be alleviated by a proper choice of filter and the use of a liquid scintillation cocktail which dissolves the filter. Filter-Solv has been used to dissolve cellulose nitrate filters and filters which are a combination of cellulose nitrate and cellulose acetate. Count rates obtained for these dissolved samples are very reproducible and highly efficient

  8. Leveraging multiple datasets for deep leaf counting

    OpenAIRE

    Dobrescu, Andrei; Giuffrida, Mario Valerio; Tsaftaris, Sotirios A

    2017-01-01

    The number of leaves a plant has is one of the key traits (phenotypes) describing its development and growth. Here, we propose an automated, deep learning based approach for counting leaves in model rosette plants. While state-of-the-art results on leaf counting with deep learning methods have recently been reported, they obtain the count as a result of leaf segmentation and thus require per-leaf (instance) segmentation to train the models (a rather strong annotation). Instead, our method tre...

  9. Resonance ionization spectroscopy: Counting noble gas atoms

    International Nuclear Information System (INIS)

    Hurst, G.S.; Payne, M.G.; Chen, C.H.; Willis, R.D.; Lehmann, B.E.; Kramer, S.D.

    1981-01-01

    The purpose of this paper is to describe new work on the counting of noble gas atoms, using lasers for the selective ionization and detectors for counting individual particles (electrons or positive ions). When positive ions are counted, various kinds of mass analyzers (magnetic, quadrupole, or time-of-flight) can be incorporated to provide A selectivity. We show that a variety of interesting and important applications can be made with atom-counting techniques which are both atomic number (Z) and mass number (A) selective. (orig./FKS)

  10. Performance of the latest MPPCs with reduced dark counts and improved photon detection efficiency

    International Nuclear Information System (INIS)

    Tsujikawa, T.; Funamoto, H.; Kataoka, J.; Fujita, T.; Nishiyama, T.; Kurei, Y.; Sato, K.; Yamamura, K.; Nakamura, S.

    2014-01-01

    We have tested the performance of two types of the latest Multi-Pixel Photon Counters (MPPCs; measuring 3×3 mm 2 in size) developed by Hamamatsu Photonics K.K. The new S12572-050C is a successor to the S10362-33-050C (i.e., conventional 3×3-mm 2 pixel MPPC of 50 μm pitch), comprises 3600 Geiger mode avalanche photodiodes (APDs), and also features high gain (up to 1.25×10 6 ), a low dark count (up to 10 6 cps), and improved photon detection efficiency (PDE) by up to 30%. The S12572-015C is a new type of fine-pitch (15 μm) MPPC featuring a wide dynamic range and fast timing response. This paper first presents the detailed performance of these latest MPPCs as photon counting devices. It then describes our fabrication of a prototype detector consisting of a MPPC optically coupled with a Ce:GAGG scintillator. We obtained average FWHM energy resolutions of 7.3% (15 μm) and 6.7% (new-50 μm), as compared to 6.9% (old-50 μm) for 662-keV gamma rays from the 137 Cs source, as measured at 20 °C. Moreover, the number of fired pixels for 662-keV gamma rays increased by 30% for the new-50 μm (as compared to the old-50 μm). We confirmed that the low energy threshold improved from 10 keV to 4 keV, when using the latest MPPC device (new-50 μm). We also confirmed that the timing resolution of the new MPPC is 50 ps or even better, as compared to 89 ps of the old MPPC. The results thus confirm that these new types of MPPCs are promising for various applications as scintillation detectors. - Highlights: • We tested the performance of the latest MPPC. • We confirmed that the new MPPC is superior to the old MPPC. • We plan to apply the new MPPC for a next-generation PET and a handy Compton camera

  11. Performance of the latest MPPCs with reduced dark counts and improved photon detection efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Tsujikawa, T., E-mail: takayuki-t.w@asagi.waseda.jp [Research Institute for Science and Engineering, Waseda University, 3-4-1, Ohkubo, Shinjuku, Tokyo (Japan); Funamoto, H.; Kataoka, J.; Fujita, T.; Nishiyama, T.; Kurei, Y. [Research Institute for Science and Engineering, Waseda University, 3-4-1, Ohkubo, Shinjuku, Tokyo (Japan); Sato, K.; Yamamura, K.; Nakamura, S. [Solid State Division, Hamamatsu Photonics K. K., 1126-1, Ichino-cho, Hamamatsu, Shizuoka (Japan)

    2014-11-21

    We have tested the performance of two types of the latest Multi-Pixel Photon Counters (MPPCs; measuring 3×3 mm{sup 2} in size) developed by Hamamatsu Photonics K.K. The new S12572-050C is a successor to the S10362-33-050C (i.e., conventional 3×3-mm{sup 2} pixel MPPC of 50 μm pitch), comprises 3600 Geiger mode avalanche photodiodes (APDs), and also features high gain (up to 1.25×10{sup 6}), a low dark count (up to 10{sup 6} cps), and improved photon detection efficiency (PDE) by up to 30%. The S12572-015C is a new type of fine-pitch (15 μm) MPPC featuring a wide dynamic range and fast timing response. This paper first presents the detailed performance of these latest MPPCs as photon counting devices. It then describes our fabrication of a prototype detector consisting of a MPPC optically coupled with a Ce:GAGG scintillator. We obtained average FWHM energy resolutions of 7.3% (15 μm) and 6.7% (new-50 μm), as compared to 6.9% (old-50 μm) for 662-keV gamma rays from the {sup 137}Cs source, as measured at 20 °C. Moreover, the number of fired pixels for 662-keV gamma rays increased by 30% for the new-50 μm (as compared to the old-50 μm). We confirmed that the low energy threshold improved from 10 keV to 4 keV, when using the latest MPPC device (new-50 μm). We also confirmed that the timing resolution of the new MPPC is 50 ps or even better, as compared to 89 ps of the old MPPC. The results thus confirm that these new types of MPPCs are promising for various applications as scintillation detectors. - Highlights: • We tested the performance of the latest MPPC. • We confirmed that the new MPPC is superior to the old MPPC. • We plan to apply the new MPPC for a next-generation PET and a handy Compton camera.

  12. Whole-body counting 1990

    International Nuclear Information System (INIS)

    Strand, P.; Selnaes, T.D.

    1990-01-01

    In order to determine the doses from radiocesium in foods after the Chernobyl accident, four groups were chosen in 1987. Two groups, presumed to have a large consumption of food items with a high radiocesium content, were selected. These were Lapp reindeer breeders from central parts of Norway, and hunters a.o. from the municipality of Oeystre Slidre. Two other groups were randomly selected, one from the municipality of Sel, and one from Oslo. The persons in these two groups were presumed to have an average diet. The fall-out in Sel was fairly large (100 kBq/m 2 ), whereas in Oslo the fall-out level was low (2 kBq/m 2 ). The persons in each group were monitored once a year with whole-body counters, and in connection with these countings dietary surveys were preformed. In 1990 the Sel-group and the Lapps in central parts of Norway were followed. Average whole-body activity in each group is compared to earlier years's results, and an average yearly effective dose equivalent is computed. The Sel-group has an average whole-body activity of 2800 Bq for men, and 690 Bq for women. Compared to earlier years, there is a steady but slow decrease in whole-body activities. Yearly dose is calculated to 0.06 mSv for 1990. The Lapps in central parts of Norway have an average whole-body content of 23800 Bq for men and 13600 Bq for women. This results in an average yearly dose of 0.9 mSv for the individuals in the group. Compared to earlier years, the Lapp group show a decrease in whole-body contents since 1988. This decrease is larger among men than women. 5 refs., 8 figs., 6 tabs

  13. System and method of liquid scintillation counting

    International Nuclear Information System (INIS)

    Rapkin, E.

    1977-01-01

    A method of liquid scintillation counting utilizing a combustion step to overcome quenching effects comprises novel features of automatic sequential introduction of samples into a combustion zone and automatic sequential collection and delivery of combustion products into a counting zone. 37 claims, 13 figures

  14. Is It Counting, or Is It Adding?

    Science.gov (United States)

    Eisenhardt, Sara; Fisher, Molly H.; Thomas, Jonathan; Schack, Edna O.; Tassell, Janet; Yoder, Margaret

    2014-01-01

    The Common Core State Standards for Mathematics (CCSSI 2010) expect second grade students to "fluently add and subtract within 20 using mental strategies" (2.OA.B.2). Most children begin with number word sequences and counting approximations and then develop greater skill with counting. But do all teachers really understand how this…

  15. Current status of liquid scintillation counting

    International Nuclear Information System (INIS)

    Klingler, G.W.

    1981-01-01

    Scintillation counting of alpha particles has been used since the turn of the century. The advent of pulse shape discrimination has made this method of detection accurate and reliable. The history, concepts and development of scintillation counting and pulse shape discrimination are discussed. A brief look at the ongoing work in the consolidation of components now used for pulse shape discrimination is included

  16. Lazy reference counting for the Microgrid

    NARCIS (Netherlands)

    Poss, R.; Grelck, C.; Herhut, S.; Scholz, S.-B.

    2012-01-01

    This papers revisits non-deferred reference counting, a common technique to ensure that potentially shared large heap objects can be reused safely when they are both input and output to computations. Traditionally, thread-safe reference counting exploit implicit memory-based communication of counter

  17. A Word Count of Modern Arabic Prose.

    Science.gov (United States)

    Landau, Jacob M.

    This book presents a word count of Arabic prose based on 60 twentieth-century Egyptian books. The text is divided into an alphabetical list and a word frequency list. This word count is intended as an aid in the: (1) writing of primers and the compilation of graded readers, (2) examination of the vocabulary selection of primers and readers…

  18. 2013 Kids Count in Colorado! Community Matters

    Science.gov (United States)

    Colorado Children's Campaign, 2013

    2013-01-01

    "Kids Count in Colorado!" is an annual publication of the Children's Campaign, providing state and county level data on child well-being factors including child health, education, and economic status. Since its first release 20 years ago, "Kids Count in Colorado!" has become the most trusted source for data and information on…

  19. Standardization of {sup 241}Am by digital coincidence counting, liquid scintillation counting and defined solid angle counting

    Energy Technology Data Exchange (ETDEWEB)

    Balpardo, C., E-mail: balpardo@cae.cnea.gov.a [Laboratorio de Metrologia de Radioisotopos, CNEA, Buenos Aires (Argentina); Capoulat, M.E.; Rodrigues, D.; Arenillas, P. [Laboratorio de Metrologia de Radioisotopos, CNEA, Buenos Aires (Argentina)

    2010-07-15

    The nuclide {sup 241}Am decays by alpha emission to {sup 237}Np. Most of the decays (84.6%) populate the excited level of {sup 237}Np with energy of 59.54 keV. Digital coincidence counting was applied to standardize a solution of {sup 241}Am by alpha-gamma coincidence counting with efficiency extrapolation. Electronic discrimination was implemented with a pressurized proportional counter and the results were compared with two other independent techniques: Liquid scintillation counting using the logical sum of double coincidences in a TDCR array and defined solid angle counting taking into account activity inhomogeneity in the active deposit. The results show consistency between the three methods within a limit of a 0.3%. An ampoule of this solution will be sent to the International Reference System (SIR) during 2009. Uncertainties were analysed and compared in detail for the three applied methods.

  20. An Adaptive Smoother for Counting Measurements

    International Nuclear Information System (INIS)

    Kondrasovs Vladimir; Coulon Romain; Normand Stephane

    2013-06-01

    Counting measurements associated with nuclear instruments are tricky to carry out due to the stochastic process of the radioactivity. Indeed events counting have to be processed and filtered in order to display a stable count rate value and to allow variations monitoring in the measured activity. Smoothers (as the moving average) are adjusted by a time constant defined as a compromise between stability and response time. A new approach has been developed and consists in improving the response time while maintaining count rate stability. It uses the combination of a smoother together with a detection filter. A memory of counting data is processed to calculate several count rate estimates using several integration times. These estimates are then sorted into the memory from short to long integration times. A measurement position, in terms of integration time, is then chosen into this memory after a detection test. An inhomogeneity into the Poisson counting process is detected by comparison between current position estimate and the other estimates contained into the memory in respect with the associated statistical variance calculated with homogeneous assumption. The measurement position (historical time) and the ability to forget an obsolete data or to keep in memory a useful data are managed using the detection test result. The proposed smoother is then an adaptive and a learning algorithm allowing an optimization of the response time while maintaining measurement counting stability and converging efficiently to the best counting estimate after an effective change in activity. This algorithm has also the specificity to be low recursive and thus easily embedded into DSP electronics based on FPGA or micro-controllers meeting 'real life' time requirements. (authors)

  1. The effect of volume and quenching on estimation of counting efficiencies in liquid scintillation counting

    International Nuclear Information System (INIS)

    Knoche, H.W.; Parkhurst, A.M.; Tam, S.W.

    1979-01-01

    The effect of volume on the liquid scintillation counting performance of 14 C-samples has been investigated. A decrease in counting efficiency was observed for samples with volumes below about 6 ml and those above about 18 ml when unquenched samples were assayed. Two quench-correction methods, sample channels ratio and external standard channels ratio, and three different liquid scintillation counters, were used in an investigation to determine the magnitude of the error in predicting counting efficiencies when small volume samples (2 ml) with different levels of quenching were assayed. The 2 ml samples exhibited slightly greater standard deviations of the difference between predicted and determined counting efficiencies than did 15 ml samples. Nevertheless, the magnitude of the errors indicate that if the sample channels ratio method of quench correction is employed, 2 ml samples may be counted in conventional counting vials with little loss in counting precision. (author)

  2. Radiation Counting System Software Using Visual Basic

    International Nuclear Information System (INIS)

    Nanda Nagara; Didi Gayani

    2009-01-01

    It has been created a Gamma Radiation Counting System using interface card, which paired with Personal Computer (PC) and operated by the Visual Basic program. The program was set through varied menu selections such as ”Multi Counting” , ”Counting and Record” and ”View Data”. An interface card for data acquisition was formed by using AMD9513 components as a counter and timer which can be programmed. This counting system was tested and used in waste facility in PTNBR and the result is quite good. (author)

  3. Algorithm for counting large directed loops

    Energy Technology Data Exchange (ETDEWEB)

    Bianconi, Ginestra [Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy); Gulbahce, Natali [Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, NM 87545 (United States)

    2008-06-06

    We derive a Belief-Propagation algorithm for counting large loops in a directed network. We evaluate the distribution of the number of small loops in a directed random network with given degree sequence. We apply the algorithm to a few characteristic directed networks of various network sizes and loop structures and compare the algorithm with exhaustive counting results when possible. The algorithm is adequate in estimating loop counts for large directed networks and can be used to compare the loop structure of directed networks and their randomized counterparts.

  4. Counts and colors of faint galaxies

    International Nuclear Information System (INIS)

    Kron, R.G.

    1980-01-01

    The color distribution of faint galaxies is an observational dimension which has not yet been fully exploited, despite the important constraints obtainable for galaxy evolution and cosmology. Number-magnitude counts alone contain very diluted information about the state of things because galaxies from a wide range in redshift contribute to the counts at each magnitude. The most-frequently-seen type of galaxy depends on the luminosity function and the relative proportions of galaxies of different spectral classes. The addition of color as a measured quantity can thus considerably sharpen the interpretation of galaxy counts since the apparent color depends on the redshift and rest-frame spectrum. (Auth.)

  5. A measurement technique for counting processes

    International Nuclear Information System (INIS)

    Cantoni, V.; Pavia Univ.; De Lotto, I.; Valenziano, F.

    1980-01-01

    A technique for the estimation of first and second order properties of a stationary counting process is presented here which uses standard instruments for analysis of a continuous stationary random signal. (orig.)

  6. Why calories count: from science to politics

    National Research Council Canada - National Science Library

    Nestle, Marion; Nesheim, Malden C

    2012-01-01

    .... They are also hard to understand. In Why Calories Count, Marion Nestle and Malden Nesheim explain in clear and accessible language what calories are and how they work, both biologically and politically...

  7. CoC Housing Inventory Count Reports

    Data.gov (United States)

    Department of Housing and Urban Development — Continuum of Care (CoC) Homeless Assistance Programs Housing Inventory Count Reports are a snapshot of a CoC’s housing inventory, available at the national and state...

  8. White Blood Cell Counts and Malaria

    National Research Council Canada - National Science Library

    McKenzie, F. E; Prudhomme, Wendy A; Magill, Alan J; Forney, J. R; Permpanich, Barnyen; Lucas, Carmen; Gasser, Jr., Robert A; Wongsrichanalai, Chansuda

    2005-01-01

    White blood cells (WBCs) were counted in 4697 individuals who presented to outpatient malaria clinics in Maesod, Tak Province, Thailand, and Iquitos, Peru, between 28 May and 28 August 1998 and between 17 May and 9 July 1999...

  9. VSRR Provisional Drug Overdose Death Counts

    Data.gov (United States)

    U.S. Department of Health & Human Services — This data contains provisional counts for drug overdose deaths based on a current flow of mortality data in the National Vital Statistics System. National...

  10. Low white blood cell count and cancer

    Science.gov (United States)

    ... gov/ency/patientinstructions/000675.htm Low white blood cell count and cancer To use the sharing features on this page, please enable JavaScript. White blood cells (WBCs) fight infections from bacteria, viruses, fungi, and ...

  11. Regression Models For Multivariate Count Data.

    Science.gov (United States)

    Zhang, Yiwen; Zhou, Hua; Zhou, Jin; Sun, Wei

    2017-01-01

    Data with multivariate count responses frequently occur in modern applications. The commonly used multinomial-logit model is limiting due to its restrictive mean-variance structure. For instance, analyzing count data from the recent RNA-seq technology by the multinomial-logit model leads to serious errors in hypothesis testing. The ubiquity of over-dispersion and complicated correlation structures among multivariate counts calls for more flexible regression models. In this article, we study some generalized linear models that incorporate various correlation structures among the counts. Current literature lacks a treatment of these models, partly due to the fact that they do not belong to the natural exponential family. We study the estimation, testing, and variable selection for these models in a unifying framework. The regression models are compared on both synthetic and real RNA-seq data.

  12. Count rate effect in proportional counters

    International Nuclear Information System (INIS)

    Bednarek, B.

    1980-01-01

    A new concept is presented explaining changes in spectrometric parameters of proportional counters which occur due to varying count rate. The basic feature of this concept is that the gas gain of the counter remains constant in a wide range of count rate and that the decrease in the pulse amplitude and the detorioration of the energy resolution observed are the results of changes in the shape of original current pulses generated in the active volume of the counter. In order to confirm the validity of this statement, measurements of the gas amplification factor have been made in a wide count rate range. It is shown that above a certain critical value the gas gain depends on both the operating voltage and the count rate. (author)

  13. Atom counting with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Kutschera, Walter

    1995-01-01

    A brief review of the current status and some recent applications of accelerator mass spectrometry (AMS) are presented. Some connections to resonance ionization mass spectroscopy (RIS) as the alternate atom counting method are discussed

  14. Internal dosimetry by whole body counting techniques

    International Nuclear Information System (INIS)

    Sharma, R.C.

    1995-01-01

    Over decades, whole body counting and bioassay - the two principal methods of internal dosimetry have been most widely used to assess, limit and control the intakes of radioactive materials and the consequent internal doses by the workers in nuclear industry. This paper deals with the whole body counting techniques. The problems inherent in the interpretation of monitoring data and likely future directions of development in the assessments of internal doses by direct methods are outlined. (author). 14 refs., 9 figs., 1 tab

  15. How to count an introduction to combinatorics

    CERN Document Server

    Allenby, RBJT

    2010-01-01

    What's It All About? What Is Combinatorics? Classic Problems What You Need to Know Are You Sitting Comfortably? Permutations and Combinations The Combinatorial Approach Permutations CombinationsApplications to Probability Problems The Multinomial Theorem Permutations and Cycles Occupancy Problems Counting the Solutions of Equations New Problems from Old A ""Reduction"" Theorem for the Stirling Numbers The Inclusion-Exclusion Principle Double Counting Derangements A Formula for the Stirling NumbersStirling and Catalan Numbers Stirling Numbers Permutations and Stirling Numbers Catalan Numbers Pa

  16. Accuracy and precision in activation analysis: counting

    International Nuclear Information System (INIS)

    Becker, D.A.

    1974-01-01

    Accuracy and precision in activation analysis was investigated with regard to counting of induced radioactivity. The various parameters discussed include configuration, positioning, density, homogeneity, intensity, radioisotopic purity, peak integration, and nuclear constants. Experimental results are presented for many of these parameters. The results obtained indicate that counting errors often contribute significantly to the inaccuracy and imprecision of analyses. The magnitude of these errors range from less than 1 percent to 10 percent or more in many cases

  17. Remote system for counting of nuclear pulses

    International Nuclear Information System (INIS)

    Nieves V, J.A.; Garcia H, J.M.; Aguilar B, M.A.

    1999-01-01

    In this work, it is describe technically the remote system for counting of nuclear pulses, an integral system of the project radiological monitoring in a petroleum distillation tower. The system acquires the counting of incident nuclear particles in a nuclear detector which process this information and send it in serial form, using the RS-485 toward a remote receiver, which can be a Personal computer or any other device capable to interpret the communication protocol. (Author)

  18. Digital Survey Meter based on PIC16F628 Microcontroller

    International Nuclear Information System (INIS)

    Al-Mohamad, A.; Shliwitt, J.

    2010-01-01

    A Digital Survey Meter based on PIC16F628 Microcontroller was designed using simple Geiger-Muller Counter ZP1320 made by Centronic in the UK as detector. The sensitivity of this tube is about 9 counts/s at 10μGy/h. It is sensitive to gamma and beta particles over 0.25 MeV. It has a sensitive length of 28mm. Count rate versus dose rate is quite linear up to about 10 4 counts/s. Indication is given by a speaker which emits one click for each count. In addition to the acoustic alarm, the meter works according one of three different measurement modes selected using appropriate 3 states switch: 1- Measurement of Dose rate ( in μGy/h) and counting rate ( in CPS) , for High counting rates. 2- Measurement of Dose rate ( in μGy/h) and counting rate ( in CPM), for Low counting rates. 3- Accumulated Counting with continues display for No. of Counts and Counting Time with a period of 2 Sec. The results are Displayed on an Alphanumerical LCD Display, and the circuit will give many hours of operation from a single 9V PP3 battery. The design of the circuit combines between accuracy, simplicity and low power consumption. We built 2 Models of this design, the first only with an internal detector, and the second is equipped with an External Detector. (author)

  19. Recursive algorithms for phylogenetic tree counting.

    Science.gov (United States)

    Gavryushkina, Alexandra; Welch, David; Drummond, Alexei J

    2013-10-28

    In Bayesian phylogenetic inference we are interested in distributions over a space of trees. The number of trees in a tree space is an important characteristic of the space and is useful for specifying prior distributions. When all samples come from the same time point and no prior information available on divergence times, the tree counting problem is easy. However, when fossil evidence is used in the inference to constrain the tree or data are sampled serially, new tree spaces arise and counting the number of trees is more difficult. We describe an algorithm that is polynomial in the number of sampled individuals for counting of resolutions of a constraint tree assuming that the number of constraints is fixed. We generalise this algorithm to counting resolutions of a fully ranked constraint tree. We describe a quadratic algorithm for counting the number of possible fully ranked trees on n sampled individuals. We introduce a new type of tree, called a fully ranked tree with sampled ancestors, and describe a cubic time algorithm for counting the number of such trees on n sampled individuals. These algorithms should be employed for Bayesian Markov chain Monte Carlo inference when fossil data are included or data are serially sampled.

  20. Preverbal and verbal counting and computation.

    Science.gov (United States)

    Gallistel, C R; Gelman, R

    1992-08-01

    We describe the preverbal system of counting and arithmetic reasoning revealed by experiments on numerical representations in animals. In this system, numerosities are represented by magnitudes, which are rapidly but inaccurately generated by the Meck and Church (1983) preverbal counting mechanism. We suggest the following. (1) The preverbal counting mechanism is the source of the implicit principles that guide the acquisition of verbal counting. (2) The preverbal system of arithmetic computation provides the framework for the assimilation of the verbal system. (3) Learning to count involves, in part, learning a mapping from the preverbal numerical magnitudes to the verbal and written number symbols and the inverse mappings from these symbols to the preverbal magnitudes. (4) Subitizing is the use of the preverbal counting process and the mapping from the resulting magnitudes to number words in order to generate rapidly the number words for small numerosities. (5) The retrieval of the number facts, which plays a central role in verbal computation, is mediated via the inverse mappings from verbal and written numbers to the preverbal magnitudes and the use of these magnitudes to find the appropriate cells in tabular arrangements of the answers. (6) This model of the fact retrieval process accounts for the salient features of the reaction time differences and error patterns revealed by experiments on mental arithmetic. (7) The application of verbal and written computational algorithms goes on in parallel with, and is to some extent guided by, preverbal computations, both in the child and in the adult.

  1. Seed counting system evaluation using arduino microcontroller

    Directory of Open Access Journals (Sweden)

    Paulo Fernando Escobar Paim

    2018-01-01

    Full Text Available The development of automated systems has been highlighted in the most diverse productive sectors, among them, the agricultural sector. These systems aim to optimize activities by increasing operational efficiency and quality of work. In this sense, the present work has the objective of evaluating a prototype developed for seed count in laboratory, using Arduino microcontroller. The prototype of the system for seed counting was built using a dosing mechanism commonly used in seeders, electric motor, Arduino Uno, light dependent resistor and light emitting diode. To test the prototype, a completely randomized design (CRD was used in a two-factorial scheme composed of three groups defined according to the number of seeds (500, 1000 and 1500 seeds tested, three speeds of the dosing disc that allowed the distribution in 17, 21 and 32 seeds per second, with 40 repetitions evaluating the seed counting prototype performance in different speeds. The prototype of the bench counter showed a moderate variability of seed number of counted within the nine tests and a high precision in the seed count on the distribution speeds of 17 and 21 seeds per second (s-1 up to 1500 seeds tested. Therefore, based on the observed results, the developed prototype presents itself as an excellent tool for counting seeds in laboratory.

  2. Photon counting and fluctuation of molecular movement

    International Nuclear Information System (INIS)

    Inohara, Koichi

    1978-01-01

    The direct measurement of the fluctuation of molecular motions, which provides with useful information on the molecular movement, was conducted by introducing photon counting method. The utilization of photon counting makes it possible to treat the molecular system consisting of a small number of molecules like a radioisotope in the detection of a small number of atoms, which are significant in biological systems. This method is based on counting the number of photons of the definite polarization emitted in a definite time interval from the fluorescent molecules excited by pulsed light, which are bound to the marked large molecules found in a definite spatial region. Using the probability of finding a number of molecules oriented in a definite direction in the definite spatial region, the probability of counting a number of photons in a definite time interval can be calculated. Thus the measurable count rate of photons can be related with the fluctuation of molecular movement. The measurement was carried out under the condition, in which the probability of the simultaneous arrival of more than two photons at a detector is less than 1/100. As the experimental results, the resolving power of photon-counting apparatus, the frequency distribution of the number of photons of some definite polarization counted for 1 nanosecond are shown. In the solution, the variance of the number of molecules of 500 on the average is 1200, which was estimated from the experimental data by assuming normal distribution. This departure from the Poisson distribution means that a certain correlation does exist in molecular movement. In solid solution, no significant deviation was observed. The correlation existing in molecular movement can be expressed in terms of the fluctuation of the number of molecules. (Nakai, Y.)

  3. Noun Countability; Count Nouns and Non-count Nouns, What are the Syntactic Differences Between them?

    Directory of Open Access Journals (Sweden)

    Azhar A. Alkazwini

    2016-11-01

    Full Text Available Words that function as the subjects of verbs, objects of verbs or prepositions and which can have a plural form and possessive ending are known as nouns. They are described as referring to persons, places, things, states, or qualities and might also be used as an attributive modifier. In this paper, classes and subclasses of nouns shall be presented, then, noun countability branching into count and non-count nous shall be discussed. A number of present examples illustrating differences between count and non-count nouns and this includes determiner-head-co-occurrence restrictions of number, subject-verb agreement, in addition to some exceptions to this agreement rule shall be discussed. Also, the lexically inherent number in nouns and how inherently plural nouns are classified in terms of (+/- count are illustrated. This research will discuss partitive construction of count and non-count nouns, nouns as attributive modifier and, finally, conclude with the fact that there are syntactic difference between count and non-count in the English Language.

  4. Benjamin Thompson, Count Rumford Count Rumford on the nature of heat

    CERN Document Server

    Brown, Sanborn C

    1967-01-01

    Men of Physics: Benjamin Thompson - Count Rumford: Count Rumford on the Nature of Heat covers the significant contributions of Count Rumford in the fields of physics. Count Rumford was born with the name Benjamin Thompson on March 23, 1753, in Woburn, Massachusetts. This book is composed of two parts encompassing 11 chapters, and begins with a presentation of Benjamin Thompson's biography and his interest in physics, particularly as an advocate of an """"anti-caloric"""" theory of heat. The subsequent chapters are devoted to his many discoveries that profoundly affected the physical thought

  5. Blood Count Tests: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish WBC count (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Blood Count Tests ... WBC count Show More Show Less Related Health Topics Bleeding Disorders Blood Laboratory Tests National Institutes of ...

  6. It counts who counts: an experimental evaluation of the importance of observer effects on spotlight count estimates

    DEFF Research Database (Denmark)

    Sunde, Peter; Jessen, Lonnie

    2013-01-01

    observers with respect to their ability to detect and estimate distance to realistic animal silhouettes at different distances. Detection probabilities were higher for observers experienced in spotlighting mammals than for inexperienced observers, higher for observers with a hunting background compared...... with non-hunters and decreased as function of age but were independent of sex or educational background. If observer-specific detection probabilities were applied to real counting routes, point count estimates from inexperienced observers without a hunting background would only be 43 % (95 % CI, 39...

  7. Protecting count queries in study design.

    Science.gov (United States)

    Vinterbo, Staal A; Sarwate, Anand D; Boxwala, Aziz A

    2012-01-01

    Today's clinical research institutions provide tools for researchers to query their data warehouses for counts of patients. To protect patient privacy, counts are perturbed before reporting; this compromises their utility for increased privacy. The goal of this study is to extend current query answer systems to guarantee a quantifiable level of privacy and allow users to tailor perturbations to maximize the usefulness according to their needs. A perturbation mechanism was designed in which users are given options with respect to scale and direction of the perturbation. The mechanism translates the true count, user preferences, and a privacy level within administrator-specified bounds into a probability distribution from which the perturbed count is drawn. Users can significantly impact the scale and direction of the count perturbation and can receive more accurate final cohort estimates. Strong and semantically meaningful differential privacy is guaranteed, providing for a unified privacy accounting system that can support role-based trust levels. This study provides an open source web-enabled tool to investigate visually and numerically the interaction between system parameters, including required privacy level and user preference settings. Quantifying privacy allows system administrators to provide users with a privacy budget and to monitor its expenditure, enabling users to control the inevitable loss of utility. While current measures of privacy are conservative, this system can take advantage of future advances in privacy measurement. The system provides new ways of trading off privacy and utility that are not provided in current study design systems.

  8. Delta count-rate monitoring system

    International Nuclear Information System (INIS)

    Van Etten, D.; Olsen, W.A.

    1985-01-01

    A need for a more effective way to rapidly search for gamma-ray contamination over large areas led to the design and construction of a very sensitive gamma detection system. The delta count-rate monitoring system was installed in a four-wheel-drive van instrumented for environmental surveillance and accident response. The system consists of four main sections: (1) two scintillation detectors, (2) high-voltage power supply amplifier and single-channel analyzer, (3) delta count-rate monitor, and (4) count-rate meter and recorder. The van's 6.5-kW generator powers the standard nuclear instrument modular design system. The two detectors are mounted in the rear corners of the van and can be run singly or jointly. A solid-state bar-graph count-rate meter mounted on the dashboard can be read easily by both the driver and passenger. A solid-state strip chart recorder shows trends and provides a permanent record of the data. An audible alarm is sounded at the delta monitor and at the dashboard count-rate meter if a detected radiation level exceeds the set background level by a predetermined amount

  9. BMI in relation to sperm count

    DEFF Research Database (Denmark)

    Sermondade, N; Faure, C; Fezeu, L

    2013-01-01

    BACKGROUND The global obesity epidemic has paralleled a decrease in semen quality. Yet, the association between obesity and sperm parameters remains controversial. The purpose of this report was to update the evidence on the association between BMI and sperm count through a systematic review...... with meta-analysis. METHODS A systematic review of available literature (with no language restriction) was performed to investigate the impact of BMI on sperm count. Relevant studies published until June 2012 were identified from a Pubmed and EMBASE search. We also included unpublished data (n = 717 men...... studies were included in the meta-analysis, resulting in a sample of 13 077 men from the general population and attending fertility clinics. Data were stratified according to the total sperm count as normozoospermia, oligozoospermia and azoospermia. Standardized weighted mean differences in sperm...

  10. Multiple sample, radioactive particle counting apparatus

    International Nuclear Information System (INIS)

    Reddy, R.R.V.; Kelso, D.M.

    1978-01-01

    An apparatus is described for determining the respective radioactive particle sample count being emitted from radioactive particle containing samples. It includes means for modulating the information on the radioactive particles being emitted from the samples, coded detecting means for sequentially detecting different respective coded combinations of the radioactive particles emitted from more than one but less than all of the samples, and processing the modulated information to derive the sample count for each sample. It includes a single light emitting crystal next to a number of samples, an encoder belt sequentially movable between the crystal and the samples. The encoder belt has a coded array of apertures to provide corresponding modulated light pulses from the crystal, and a photomultiplier tube to convert the modulated light pulses to decodable electrical signals for deriving the respective sample count

  11. CERN_DxCTA counting mode chip

    CERN Document Server

    Moraes, D; Nygård, E

    2008-01-01

    This ASIC is a counting mode front-end electronic optimized for the readout of CdZnTe/CdTe and silicon sensors, for possible use in applications where the flux of ionizing radiation is high. The chip is implemented in 0.25 μm CMOS technology. The circuit comprises 128 channels equipped with a transimpedance amplifier followed by a gain shaper stage with 21 ns peaking time, two discriminators and two 18-bit counters. The channel architecture is optimized for the detector characteristics in order to achieve the best energy resolution at counting rates of up to 5 M counts/second. The amplifier shows a linear sensitivity of 118 mV/fC and an equivalent noise charge of about 711 e−, for a detector capacitance of 5 pF. Complete evaluation of the circuit is presented using electronic pulses and pixel detectors.

  12. CERNDxCTA counting mode chip

    International Nuclear Information System (INIS)

    Moraes, D.; Kaplon, J.; Nygard, E.

    2008-01-01

    This ASIC is a counting mode front-end electronic optimized for the readout of CdZnTe/CdTe and silicon sensors, for possible use in applications where the flux of ionizing radiation is high. The chip is implemented in 0.25 μm CMOS technology. The circuit comprises 128 channels equipped with a transimpedance amplifier followed by a gain shaper stage with 21 ns peaking time, two discriminators and two 18-bit counters. The channel architecture is optimized for the detector characteristics in order to achieve the best energy resolution at counting rates of up to 5 M counts/second. The amplifier shows a linear sensitivity of 118 mV/fC and an equivalent noise charge of about 711 e - , for a detector capacitance of 5 pF. Complete evaluation of the circuit is presented using electronic pulses and pixel detectors

  13. Detection limits for radioanalytical counting techniques

    International Nuclear Information System (INIS)

    Hartwell, J.K.

    1975-06-01

    In low-level radioanalysis it is usually necessary to test the sample net counts against some ''Critical Level'' in order to determine if a given result indicates detection. This is an interpretive review of the work by Nicholson (1963), Currie (1968) and Gilbert (1974). Nicholson's evaluation of three different computational formulas for estimation of the ''Critical Level'' is discussed. The details of Nicholson's evaluation are presented along with a basic discussion of the testing procedures used. Recommendations are presented for calculation of confidence intervals, for reporting of analytical results, and for extension of the derived formula to more complex cases such as multiple background counts, multiple use of a single background count, and gamma spectrometric analysis

  14. Effects of plutonium redistribution on lung counting

    International Nuclear Information System (INIS)

    Swinth, K.L.

    1976-01-01

    Early counts of Pu deposition in lungs will tend to overestimate lung contents since calibrations are performed with a uniform distribution and since a more favorable geometry exists in contaminated subjects because the activity is closer to the periphery of the lungs. Although the concentration into the outer regions of the lungs continues as evidenced by the autopsy studies, the counts performed by L X-rays will probably underestimate the lung content; because, simplistically, the geometry several years after exposure consists of a spherical shell with a point of activity in the center. This point of activity represents concentration in the lymph nodes from which the 60 keV gamma of 241 Am will be counted, but from which few of the L X-rays will be counted (this is an example of interorgan distribution). When a correction is made to the L X-ray intensity, the lymph node contribution will tend to increase the amount subtracted while correcting for 241 Am X-rays. It is doubtful that the relative increase in X-ray intensity by concentration in the pleural and sub-pleural regions will compensate for this effect. This will make the plutonium burden disappear while the 241 Am can still be detected. This effect has been observed in a case where counts with an intraesophageal probe indicated a substantial lymph node burden. In order to improve the accuracy of in vivo plutonium measurements, an improved understanding of pulmonary distribution and of distribution effects on in vivo counting are required

  15. Count-to-count time interval distribution analysis in a fast reactor

    International Nuclear Information System (INIS)

    Perez-Navarro Gomez, A.

    1973-01-01

    The most important kinetic parameters have been measured at the zero power fast reactor CORAL-I by means of the reactor noise analysis in the time domain, using measurements of the count-to-count time intervals. (Author) 69 refs

  16. Compositions and process for liquid scintillation counting

    International Nuclear Information System (INIS)

    1974-01-01

    Liquid scintillation counting compositions which include certain polyethoxylated poly(oxypropylene) emulsifiers allow stable dispersion of aqueous or other samples merely by shaking. Preferred are mixtures of such emulsifiers which give homogeneous monophasic-appearing dispersions over wide ranges of temperature and aqueous sample content. Certain of these emulsifiers, without being mixed, are of particular advantage when used in analysis of samples obtained through radioimmunoassay techniques which are extremely difficult to disperse. Certain of these emulsifiers, also without being mixed, uniformly give homogeneous monophasic-appearing aqueous counting samples over much wider ranges of aqueous sample content and temperature than prior sample emulsifiers

  17. Counting dyons in N=4 string theory

    CERN Document Server

    Dijkgraaf, R; Verlinde, Herman L

    1997-01-01

    We present a microscopic index formula for the degeneracy of dyons in four-dimensional N=4 string theory. This counting formula is manifestly symmetric under the duality group, and its asymptotic growth reproduces the macroscopic Bekenstein-Hawking entropy. We give a derivation of this result in terms of the type II five-brane compactified on K3, by assuming that its fluctuations are described by a closed string theory on its world-volume. We find that the degeneracies are given in terms of the denominator of a generalized super Kac-Moody algebra. We also discuss the correspondence of this result with the counting of D-brane states.

  18. Isospectral discrete and quantum graphs with the same flip counts and nodal counts

    Science.gov (United States)

    Juul, Jonas S.; Joyner, Christopher H.

    2018-06-01

    The existence of non-isomorphic graphs which share the same Laplace spectrum (to be referred to as isospectral graphs) leads naturally to the following question: what additional information is required in order to resolve isospectral graphs? It was suggested by Band, Shapira and Smilansky that this might be achieved by either counting the number of nodal domains or the number of times the eigenfunctions change sign (the so-called flip count) (Band et al 2006 J. Phys. A: Math. Gen. 39 13999–4014 Band and Smilansky 2007 Eur. Phys. J. Spec. Top. 145 171–9). Recent examples of (discrete) isospectral graphs with the same flip count and nodal count have been constructed by Ammann by utilising Godsil–McKay switching (Ammann private communication). Here, we provide a simple alternative mechanism that produces systematic examples of both discrete and quantum isospectral graphs with the same flip and nodal counts.

  19. Machine for checking the radioactive contamination of clothing (1961); Machine a controler le linge du point de vue de sa contamination radioactive (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Mimaud, R; Cottignies, S [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1961-07-01

    This machine is designed to check working clothes after decontamination treatment. It checks automatically for {alpha} and {beta} {gamma} The clothing is carried on a moving belt under a rack of Geiger-Muller counters followed by zinc sulphide scintillators linked to photomultipliers. During its passage under these probes two separate counting systems count the {beta} {gamma} and the {alpha} activities. If a certain fixed rate is reached, a basket reserved for contaminated linen moves into position in front of the belt to collect the clothing; if this rate is not attained the linen is collected in another basket. The starting and stopping of counting, and the return to zero, are controlled by means of 3 photoelectric cells which detect the arrival of the clothing before and after scanning, and its delivery into the baskets. (authors) [French] Cette machine est destinee a controler les vetements de travail apres le traitement de decontamination. Elle effectue automatiquement un controle en {alpha} et en {beta} {gamma}. Le linge entraine par un tapis roulant passe sous une rampe de compteurs Geiger-Muller puis sous des scintillateurs au sulfure de zinc associes a des photomultiplicateurs. Pendant son passage sous ces sondes, deux chaines de comptage distinctes comptent l'activite {beta} {gamma} et l'activite {alpha}. Si un certain taux fixe est atteint, un panier reserve au linge contamine se positionne devant le tapis pour recueillir le linge; dans le cas contraire, le linge est recueilli dans un autre panier. Les operations de debut de comptage, arret de comptage et remise a zero de l'ensemble sont commandees a l'aide de 3 cellules photoelectriques qui detectent l'arrivee du linge avant et apres les sondes, ainsi que sa retombee dans les paniers. (auteurs)

  20. Nevada Kids Count Data Book, 1997.

    Science.gov (United States)

    We Can, Inc., Las Vegas, NV.

    This Kids Count data book is the first to examine statewide indicators of the well being of Nevada's children. The statistical portrait is based on 15 indicators of child well being: (1) percent low birth-weight babies; (2) infant mortality rate; (3) percent of children in poverty; (4) percent of children in single-parent families; (5) percent of…

  1. Isospectral graphs with identical nodal counts

    International Nuclear Information System (INIS)

    Oren, Idan; Band, Ram

    2012-01-01

    According to a recent conjecture, isospectral objects have different nodal count sequences (Gnutzmann et al 2005 J. Phys. A: Math. Gen. 38 8921–33). We study generalized Laplacians on discrete graphs, and use them to construct the first non-trivial counterexamples to this conjecture. In addition, these examples demonstrate a surprising connection between isospectral discrete and quantum graphs. (paper)

  2. Phase-space quark counting rule

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Gin, Chao; Lo, Shui-Yin [Academia Sinica, Beijing (China). Inst. of High Energy Physics

    1981-05-21

    A simple quark counting rule based on the phase-space consideration suggested before is used to fit all 39 recent experimental data points on inclusive reactions. Parameter-free relations are found to agree with experiments. Excellent detail fits are obtained for 11 inclusive reactions.

  3. Statistical tests to compare motif count exceptionalities

    Directory of Open Access Journals (Sweden)

    Vandewalle Vincent

    2007-03-01

    Full Text Available Abstract Background Finding over- or under-represented motifs in biological sequences is now a common task in genomics. Thanks to p-value calculation for motif counts, exceptional motifs are identified and represent candidate functional motifs. The present work addresses the related question of comparing the exceptionality of one motif in two different sequences. Just comparing the motif count p-values in each sequence is indeed not sufficient to decide if this motif is significantly more exceptional in one sequence compared to the other one. A statistical test is required. Results We develop and analyze two statistical tests, an exact binomial one and an asymptotic likelihood ratio test, to decide whether the exceptionality of a given motif is equivalent or significantly different in two sequences of interest. For that purpose, motif occurrences are modeled by Poisson processes, with a special care for overlapping motifs. Both tests can take the sequence compositions into account. As an illustration, we compare the octamer exceptionalities in the Escherichia coli K-12 backbone versus variable strain-specific loops. Conclusion The exact binomial test is particularly adapted for small counts. For large counts, we advise to use the likelihood ratio test which is asymptotic but strongly correlated with the exact binomial test and very simple to use.

  4. Photon counting with small pore microchannel plates

    International Nuclear Information System (INIS)

    Martindale, A.; Lapington, J.S.; Fraser, G.W.

    2007-01-01

    We describe the operation of microchannel plates (MCPs) with 3.2μm diameter channels as photon counting detectors of soft X-rays. Gain and temporal resolution measurements are compared with theoretical scaling laws for channel diameter. A minimum pulse width of 264ps is observed for a two stage multiplier at a total bias voltage of ∼1930V

  5. Alabama Kids Count 2002 Data Book.

    Science.gov (United States)

    Curtis, Apreill; Bogie, Don

    This Kids Count data book examines statewide trends in well-being of Alabamas children. The statistical portrait is based on 18 indicators in the areas of child health, education, safety, and security: (1) infant mortality rate; (2) low weight births; (3) child health index; (4) births to unmarried teens; (5) first grade retention; (6) school…

  6. Alabama Kids Count 2001 Data Book.

    Science.gov (United States)

    Curtis, Apreill; Bogie, Don

    This Kids Count data book examines statewide trends in well-being for Alabama's children. The statistical portrait is based on 17 indicators in the areas of health, education, safety, and security. The indicators are: (1) infant mortality rate; (2) low weight births; (3) child health index; (4) births to unmarried teens; (5) first grade retention;…

  7. Spontaneous Non-verbal Counting in Toddlers

    Science.gov (United States)

    Sella, Francesco; Berteletti, Ilaria; Lucangeli, Daniela; Zorzi, Marco

    2016-01-01

    A wealth of studies have investigated numerical abilities in infants and in children aged 3 or above, but research on pre-counting toddlers is sparse. Here we devised a novel version of an imitation task that was previously used to assess spontaneous focusing on numerosity (i.e. the predisposition to grasp numerical properties of the environment)…

  8. Stalking the count. Dracula, Fandom and Tourism

    NARCIS (Netherlands)

    S.L. Reijnders (Stijn)

    2011-01-01

    textabstractLarge numbers of tourists travel to Transylvania every year, looking for traces of Count Dracula. This article investigates why people feel the need to connect fictional stories, such as Dracula, with identifiable physical locations, and why they subsequently want to visit these

  9. Liquid scintillation counting (LSC) - an overview

    International Nuclear Information System (INIS)

    Ravi, S.; Mathew, K.M.

    2005-01-01

    In Liquid Scintillation Counting, the amount of light produced is proportional to the amount of radiation present in the sample and the energy of the light produced is proportional to the energy of the radiation that is present in the sample. This makes LSC a very convenient tool to measure radioactivity

  10. Counting Women's Work in Vietnam | IDRC - International ...

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

    2017-07-31

    Jul 31, 2017 ... These gender equality indicators are shedding light on girls' and women's ... Young people do a tremendous amount of unpaid care work at the ages when ... Read the report "Counting Women's Work in Vietnam" · View the ...

  11. Going Online to Make Learning Count

    Science.gov (United States)

    Brigham, Cathy; Klein-Collins, Rebecca

    2011-01-01

    Adult students often come to higher education with college-level learning that they have acquired outside of the classroom--from the workplace, military service, self-study, or hobbies. For decades, many forward-thinking colleges and universities have been offering services to evaluate that learning and award it college credit that counts towards…

  12. Health Advocacy--Counting the Costs

    Science.gov (United States)

    Dyall, Lorna; Marama, Maria

    2010-01-01

    Access to, and delivery of, safe and culturally appropriate health services is increasingly important in New Zealand. This paper will focus on counting the costs of health advocacy through the experience of a small non government charitable organisation, the Health Advocates Trust, (HAT) which aimed to provide advocacy services for a wide range of…

  13. The Fallacy of Word-Counts.

    Science.gov (United States)

    Engels, L.K.

    1968-01-01

    The greatest fallacy of word counts, the author maintains, lies in the fact that advocates of frequency lists stress the high percentage without telling the whole truth. It has become common to pretend that a frequency list of 3,000 words covers 95 percent of the language, that it enables a person to speak and understand a foreign language by…

  14. Differential white cell count by centrifugal microfluidics.

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Gregory Jon; Tentori, Augusto M.; Schaff, Ulrich Y.

    2010-07-01

    We present a method for counting white blood cells that is uniquely compatible with centrifugation based microfluidics. Blood is deposited on top of one or more layers of density media within a microfluidic disk. Spinning the disk causes the cell populations within whole blood to settle through the media, reaching an equilibrium based on the density of each cell type. Separation and fluorescence measurement of cell types stained with a DNA dye is demonstrated using this technique. The integrated signal from bands of fluorescent microspheres is shown to be proportional to their initial concentration in suspension. Among the current generation of medical diagnostics are devices based on the principle of centrifuging a CD sized disk functionalized with microfluidics. These portable 'lab on a disk' devices are capable of conducting multiple assays directly from a blood sample, embodied by platforms developed by Gyros, Samsung, and Abaxis. [1,2] However, no centrifugal platform to date includes a differential white blood cell count, which is an important metric complimentary to diagnostic assays. Measuring the differential white blood cell count (the relative fraction of granulocytes, lymphocytes, and monocytes) is a standard medical diagnostic technique useful for identifying sepsis, leukemia, AIDS, radiation exposure, and a host of other conditions that affect the immune system. Several methods exist for measuring the relative white blood cell count including flow cytometry, electrical impedance, and visual identification from a stained drop of blood under a microscope. However, none of these methods is easily incorporated into a centrifugal microfluidic diagnostic platform.

  15. Counting Subspaces of a Finite Vector Space

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 11. Counting Subspaces of a Finite Vector Space – 1. Amritanshu Prasad. General Article Volume 15 Issue 11 November 2010 pp 977-987. Fulltext. Click here to view fulltext PDF. Permanent link:

  16. More accurate thermal neutron coincidence counting technique

    International Nuclear Information System (INIS)

    Baron, N.

    1978-01-01

    Using passive thermal neutron coincidence counting techniques, the accuracy of nondestructive assays of fertile material can be improved significantly using a two-ring detector. It was shown how the use of a function of the coincidence count rate ring-ratio can provide a detector response rate that is independent of variations in neutron detection efficiency caused by varying sample moderation. Furthermore, the correction for multiplication caused by SF- and (α,n)-neutrons is shown to be separable into the product of a function of the effective mass of 240 Pu (plutonium correction) and a function of the (α,n) reaction probability (matrix correction). The matrix correction is described by a function of the singles count rate ring-ratio. This correction factor is empirically observed to be identical for any combination of PuO 2 powder and matrix materials SiO 2 and MgO because of the similar relation of the (α,n)-Q value and (α,n)-reaction cross section among these matrix nuclei. However the matrix correction expression is expected to be different for matrix materials such as Na, Al, and/or Li. Nevertheless, it should be recognized that for comparison measurements among samples of similar matrix content, it is expected that some function of the singles count rate ring-ratio can be defined to account for variations in the matrix correction due to differences in the intimacy of mixture among the samples. Furthermore the magnitude of this singles count rate ring-ratio serves to identify the contaminant generating the (α,n)-neutrons. Such information is useful in process control

  17. Project and construction of counting system for neutron probe

    International Nuclear Information System (INIS)

    Monteiro, W.P.

    1985-01-01

    A counting system was developed for coupling neutron probe aiming to register pulses produced by slow neutron interaction in the detector. The neutron probe consists of fast neutron source, thermal neutron detector, amplifier circuit and pulse counting circuit. The counting system is composed by counting circuit, timer and signal circuit. (M.C.K.)

  18. Correlation between total lymphocyte count, hemoglobin, hematocrit and CD4 count in HIV patients in Nigeria.

    Science.gov (United States)

    Emuchay, Charles Iheanyichi; Okeniyi, Shemaiah Olufemi; Okeniyi, Joshua Olusegun

    2014-04-01

    The expensive and technology limited setting of CD4 count testing is a major setback to the initiation of HAART in a resource limited country like Nigeria. Simple and inexpensive tools such as Hemoglobin (Hb) measurement and Total Lymphocyte Count (TLC) are recommended as substitute marker. In order to assess the correlations of these parameters with CD4 count, 100 "apparently healthy" male volunteers tested HIV positive aged ≥ 20 years but ≤ 40 years were recruited and from whom Hb, Hct, TLC and CD4 count were obtained. The correlation coefficients, R, the Nash-Sutcliffe Coefficient of Efficiency (CoE) and the p-values of the ANOVA model of Hb, Hct and TLC with CD4 count were assessed. The assessments show that there is no significant relationship of any of these parameters with CD4 count and the correlation coefficients are very weak. This study shows that Hb, Hct and TLC cannot be substitute for CD4 count as this might lead to certain individuals' deprivation of required treatment.

  19. A counting-card circuit based on PCI bus

    International Nuclear Information System (INIS)

    Shi Jing; Li Yong; Chinese Academy of Sciences, Lanzhou; Su Hong; Dong Chengfu; Li Xiaogang; Ma Xiaoli

    2004-01-01

    A counting-card circuit based on PCI bus that we developed recently used for advanced personal computer will be introduced in this paper briefly. The maximum count capacity of this counting-card is 10 9 -1, ranging from 0 to 999 999 999, the maximum counting time range, 1 x 10 6 s, can be set in 1 cycle, the maximum counting rate is 20 MHz for positive input. (authors)

  20. PEP-4 geiger-mode hexagonal calorimeter

    International Nuclear Information System (INIS)

    Wenzel, W.A.

    1982-01-01

    The design and performance of the calorimeter are briefly described. Design aspects include illustrations of the active volume of the detector, edge connections, module assembly and analog electronics. Performance data for cosmic rays and radiation sources, including efficiency and channel sensitivity are discussed

  1. National pattern for the realization of the unit of the dose speed absorbed in air for beta radiation. (Method: Ionometer, cavity of Bragg-Gray implemented in an extrapolation chamber with electrodes of variable separation, exposed to a field of beta radiation of {sup 90}Sr/{sup 90}Y); Patron Nacional para la realizacion de la unidad de la rapidez de dosis absorbida en aire para radiacion beta. (Metodo: Ionometrico, cavidad de Bragg-Gray implementada en una camara de extrapolacion con electrodos de separacion variable, expuesta a un campo de radiacion beta de {sup 90}Sr/{sup 90}Y)

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, M T; Morales P, J R [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2001-01-15

    From the year of 1987 the Department of Metrology of the ININ, in their Secondary Laboratory of Calibration Dosimetric, has a patron group of sources of radiation beta and an extrapolation chamber of electrodes of variable separation.Their objective is to carry out of the unit of the dose speed absorbed in air for radiation beta. It uses the ionometric method, cavity Bragg-Gray in the extrapolation chamber with which it counts. The services that offers are: i) it Calibration : Radioactive Fuentes of radiation beta, isotopes: {sup 90}Sr/{sup 90}Y; Ophthalmic applicators {sup 9}0{sup S}r/{sup 90}Y; Instruments for detection of beta radiation with to the radiological protection: Ionization chambers, Geiger-Muller, etc.; Personal Dosemeters. ii) Irradiation with beta radiation of materials to the investigation. (Author)

  2. Annular shape silver lined proportional counter for on-line pulsed neutron yield measurement

    International Nuclear Information System (INIS)

    Dighe, P.M.; Das, D.

    2015-01-01

    An annular shape silver lined proportional counter is developed to measure pulsed neutron radiation. The detector has 314 mm overall length and 235 mm overall diameter. The central cavity of 150 mm diameter and 200 mm length is used for placing the neutron source. Because of annular shape the detector covers >3π solid angle of the source. The detector has all welded construction. The detector is developed in two halves for easy mounting and demounting. Each half is an independent detector. Both the halves together give single neutron pulse calibration constant of 4.5×10 4 neutrons/shot count. The detector operates in proportional mode which gives enhanced working conditions in terms of dead time and operating range compared to Geiger Muller based neutron detectors

  3. National pattern for the realization of the unit of the dose speed absorbed in air for beta radiation. (Method: Ionometer, cavity of Bragg-Gray implemented in an extrapolation chamber with electrodes of variable separation, exposed to a field of beta radiation of 90Sr/90Y)

    International Nuclear Information System (INIS)

    Alvarez R, M. T.; Morales P, J. R.

    2001-01-01

    From the year of 1987 the Department of Metrology of the ININ, in their Secondary Laboratory of Calibration Dosimetric, has a patron group of sources of radiation beta and an extrapolation chamber of electrodes of variable separation.Their objective is to carry out of the unit of the dose speed absorbed in air for radiation beta. It uses the ionometric method, cavity Bragg-Gray in the extrapolation chamber with which it counts. The services that offers are: i) it Calibration : Radioactive Fuentes of radiation beta, isotopes: 90 Sr/ 90 Y; Ophthalmic applicators 9 0 S r/ 90 Y; Instruments for detection of beta radiation with to the radiological protection: Ionization chambers, Geiger-Muller, etc.; Personal Dosemeters. ii) Irradiation with beta radiation of materials to the investigation. (Author)

  4. Arduino based radiation survey meter

    International Nuclear Information System (INIS)

    Rahman, Nur Aira Abd; Lombigit, Lojius; Abdullah, Nor Arymaswati; Azman, Azraf; Dolah, Taufik; Jaafar, Zainudin; Mohamad, Glam Hadzir Patai; Ramli, Abd Aziz Mhd; Zain, Rasif Mohd; Said, Fazila; Khalid, Mohd Ashhar; Taat, Muhamad Zahidee; Muzakkir, Amir

    2016-01-01

    This paper presents the design of new digital radiation survey meter with LND7121 Geiger Muller tube detector and Atmega328P microcontroller. Development of the survey meter prototype is carried out on Arduino Uno platform. 16-bit Timer1 on the microcontroller is utilized as external pulse counter to produce count per second or CPS measurement. Conversion from CPS to dose rate technique is also performed by Arduino to display results in micro Sievert per hour (μSvhr −1 ). Conversion factor (CF) value for conversion of CPM to μSvhr −1 determined from manufacturer data sheet is compared with CF obtained from calibration procedure. The survey meter measurement results are found to be linear for dose rates below 3500 µSv/hr

  5. Radiation dose rate meter

    International Nuclear Information System (INIS)

    Kronenberg, S.; Siebentritt, C.R.

    1981-01-01

    A combined dose rate meter and charger unit therefor which does not require the use of batteries but on the other hand produces a charging potential by means of a piezoelectric cylinder which is struck by a manually triggered hammer mechanism. A tubular type electrometer is mounted in a portable housing which additionally includes a geiger-muller (Gm) counter tube and electronic circuitry coupled to the electrometer for providing multi-mode operation. In one mode of operation, an rc circuit of predetermined time constant is connected to a storage capacitor which serves as a timed power source for the gm tube, providing a measurement in terms of dose rate which is indicated by the electrometer. In another mode, the electrometer indicates individual counts

  6. Arduino based radiation survey meter

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Nur Aira Abd, E-mail: nur-aira@nm.gov.my; Lombigit, Lojius; Abdullah, Nor Arymaswati; Azman, Azraf; Dolah, Taufik; Jaafar, Zainudin; Mohamad, Glam Hadzir Patai; Ramli, Abd Aziz Mhd; Zain, Rasif Mohd; Said, Fazila; Khalid, Mohd Ashhar; Taat, Muhamad Zahidee [Malaysian Nuclear Agency, 43000, Bangi, Selangor (Malaysia); Muzakkir, Amir [Sinaran Utama Teknologi Sdn Bhd, 43650, Bandar Baru Bangi, Selangor (Malaysia)

    2016-01-22

    This paper presents the design of new digital radiation survey meter with LND7121 Geiger Muller tube detector and Atmega328P microcontroller. Development of the survey meter prototype is carried out on Arduino Uno platform. 16-bit Timer1 on the microcontroller is utilized as external pulse counter to produce count per second or CPS measurement. Conversion from CPS to dose rate technique is also performed by Arduino to display results in micro Sievert per hour (μSvhr{sup −1}). Conversion factor (CF) value for conversion of CPM to μSvhr{sup −1} determined from manufacturer data sheet is compared with CF obtained from calibration procedure. The survey meter measurement results are found to be linear for dose rates below 3500 µSv/hr.

  7. TasselNet: counting maize tassels in the wild via local counts regression network.

    Science.gov (United States)

    Lu, Hao; Cao, Zhiguo; Xiao, Yang; Zhuang, Bohan; Shen, Chunhua

    2017-01-01

    Accurately counting maize tassels is important for monitoring the growth status of maize plants. This tedious task, however, is still mainly done by manual efforts. In the context of modern plant phenotyping, automating this task is required to meet the need of large-scale analysis of genotype and phenotype. In recent years, computer vision technologies have experienced a significant breakthrough due to the emergence of large-scale datasets and increased computational resources. Naturally image-based approaches have also received much attention in plant-related studies. Yet a fact is that most image-based systems for plant phenotyping are deployed under controlled laboratory environment. When transferring the application scenario to unconstrained in-field conditions, intrinsic and extrinsic variations in the wild pose great challenges for accurate counting of maize tassels, which goes beyond the ability of conventional image processing techniques. This calls for further robust computer vision approaches to address in-field variations. This paper studies the in-field counting problem of maize tassels. To our knowledge, this is the first time that a plant-related counting problem is considered using computer vision technologies under unconstrained field-based environment. With 361 field images collected in four experimental fields across China between 2010 and 2015 and corresponding manually-labelled dotted annotations, a novel Maize Tassels Counting ( MTC ) dataset is created and will be released with this paper. To alleviate the in-field challenges, a deep convolutional neural network-based approach termed TasselNet is proposed. TasselNet can achieve good adaptability to in-field variations via modelling the local visual characteristics of field images and regressing the local counts of maize tassels. Extensive results on the MTC dataset demonstrate that TasselNet outperforms other state-of-the-art approaches by large margins and achieves the overall best counting

  8. TasselNet: counting maize tassels in the wild via local counts regression network

    Directory of Open Access Journals (Sweden)

    Hao Lu

    2017-11-01

    Full Text Available Abstract Background Accurately counting maize tassels is important for monitoring the growth status of maize plants. This tedious task, however, is still mainly done by manual efforts. In the context of modern plant phenotyping, automating this task is required to meet the need of large-scale analysis of genotype and phenotype. In recent years, computer vision technologies have experienced a significant breakthrough due to the emergence of large-scale datasets and increased computational resources. Naturally image-based approaches have also received much attention in plant-related studies. Yet a fact is that most image-based systems for plant phenotyping are deployed under controlled laboratory environment. When transferring the application scenario to unconstrained in-field conditions, intrinsic and extrinsic variations in the wild pose great challenges for accurate counting of maize tassels, which goes beyond the ability of conventional image processing techniques. This calls for further robust computer vision approaches to address in-field variations. Results This paper studies the in-field counting problem of maize tassels. To our knowledge, this is the first time that a plant-related counting problem is considered using computer vision technologies under unconstrained field-based environment. With 361 field images collected in four experimental fields across China between 2010 and 2015 and corresponding manually-labelled dotted annotations, a novel Maize Tassels Counting (MTC dataset is created and will be released with this paper. To alleviate the in-field challenges, a deep convolutional neural network-based approach termed TasselNet is proposed. TasselNet can achieve good adaptability to in-field variations via modelling the local visual characteristics of field images and regressing the local counts of maize tassels. Extensive results on the MTC dataset demonstrate that TasselNet outperforms other state-of-the-art approaches by large

  9. Double hard scattering without double counting

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Markus [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Gaunt, Jonathan R. [VU Univ. Amsterdam (Netherlands). NIKHEF Theory Group; Schoenwald, Kay [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2017-02-15

    Double parton scattering in proton-proton collisions includes kinematic regions in which two partons inside a proton originate from the perturbative splitting of a single parton. This leads to a double counting problem between single and double hard scattering. We present a solution to this problem, which allows for the definition of double parton distributions as operator matrix elements in a proton, and which can be used at higher orders in perturbation theory. We show how the evaluation of double hard scattering in this framework can provide a rough estimate for the size of the higher-order contributions to single hard scattering that are affected by double counting. In a numeric study, we identify situations in which these higher-order contributions must be explicitly calculated and included if one wants to attain an accuracy at which double hard scattering becomes relevant, and other situations where such contributions may be neglected.

  10. Process to Obtain Quick Counts from PREP

    Directory of Open Access Journals (Sweden)

    Martínez–Cruz M.Á.

    2011-10-01

    Full Text Available Considering the Preliminary Electoral Results Program (PERP as a database of the federal elections for president of the Mexican Republic, a methodology was developed in order to find representative samples of ballot boxes installed in the election’s day (quick count in different hours, due to its characteristics of gathering of information, the PREP in the first hours forms a non-representative sample of data. In a particular way, in the election of July 2, 2006, after 3 hours of opening the PREP, it was observed that the accuracy of the process of the quick counts was better than the one obtained by the IFE. Among other things, this allows to lower the cost, to increase the confidentiality of the ballot boxes used in the sampling and to distinguish in a precise moment the winning candidate long before PREP finishes.

  11. Frontal subregions mediating Elevator Counting task performance.

    Science.gov (United States)

    MacPherson, Sarah E; Turner, Martha S; Bozzali, Marco; Cipolotti, Lisa; Shallice, Tim

    2010-10-01

    Deficits in sustained attention may lead to action slips in everyday life as irrelevant action sequences are inappropriately triggered internally or by the environment. While deficits in sustained attention have been associated with damage to the frontal lobes of the brain, little is known about the role of the frontal lobes in the Elevator Counting subtest of the Test of Everyday Attention. In the current study, 55 frontal patients subdivided into medial, orbital and lateral subgroups, 18 patients with posterior lesions and 82 healthy controls performed the Elevator Counting task. The results revealed that patients with medial and left lateral prefrontal lesions were significantly impaired on the task compared to healthy controls. Research suggests that patients with medial lesions are susceptible to competition from task irrelevant schema; whereas the left lateral group in the current study may fail to keep track of the tones already presented. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. How fast can quantum annealers count?

    International Nuclear Information System (INIS)

    Hen, Itay

    2014-01-01

    We outline an algorithm for the quantum counting problem using adiabatic quantum computation (AQC). We show that the mechanism of quantum-adiabatic evolution may be utilized toward estimating the number of solutions to a problem, and not only to find them. Using local adiabatic evolution, a process in which the adiabatic procedure is performed at a variable rate, the problem of counting the number of marked items in an unstructured database is solved quadratically faster than the corresponding classical algorithm. The above algorithm provides further evidence for the potentially powerful capabilities of AQC as a paradigm for more efficient problem solving on a quantum computer, and may be used as the basis for solving more sophisticated problems. (paper)

  13. Scintillation counting: an extrapolation into the future

    International Nuclear Information System (INIS)

    Ross, H.H.

    1983-01-01

    Progress in scintillation counting is intimately related to advances in a variety of other disciplines such as photochemistry, photophysics, and instrumentation. And while there is steady progress in the understanding of luminescent phenomena, there is a virtual explosion in the application of semiconductor technology to detectors, counting systems, and data processing. The exponential growth of this technology has had, and will continue to have, a profound effect on the art of scintillation spectroscopy. This paper will review key events in technology that have had an impact on the development of scintillation science (solid and liquid) and will attempt to extrapolate future directions based on existing and projected capability in associated fields. Along the way there have been occasional pitfalls and several false starts; these too will be discussed as a reminder that if you want the future to be different than the past, study the past

  14. Going Online to Make Learning Count

    Directory of Open Access Journals (Sweden)

    Cathy Brigham

    2011-01-01

    Full Text Available Adult students often come to higher education with college-level learning that they have acquired outside of the classroom – from the workplace, military service, self-study, or hobbies. For decades, many forward-thinking colleges and universities have been offering services to evaluate that learning and award it college credit that counts towards a degree. However, for a range of reasons, not every institution can offer prior learning assessment (PLA in every discipline or for every student. With funding from several U.S. philanthropic organizations, the Council for Adult and Experiential Learning (CAEL is launching Learning Counts, a national online service that will offer students a range of opportunities to have their learning evaluated for college credit. This online service will expand the capacity of institutions offering PLA to students and provide an efficient and scalable delivery mechanism for the awarding of credit through PLA.

  15. Liquid scintillation counting analysis of cadmium-109

    International Nuclear Information System (INIS)

    Robinson, M.K.; Barfuss, D.W.

    1991-01-01

    Recently the authors have used radiolabled cadmium-109 to measure the transport of inorganic cadmium in renal proximal tubules. An anomaly discovered in the liquid scintillation counting analysis of Cd-109 which is not attributable to normal decay; it consists of a significant decrease in the measured count rate of small amounts of sample. The objective is to determine whether the buffer solution used in the membrane transport studies is causing precipitation of the cadmium or whether cadmium is being adsorbed by the glass. It was important to determine whether the procedure could be modified to correct this problem. The problem does not appear to be related to the use of the buffer or to adsorption of Cd onto glass. Correction based on using triated L-glucose in all of these experiments and calculating a correction factor for the concentration of cadmium

  16. Double hard scattering without double counting

    International Nuclear Information System (INIS)

    Diehl, Markus; Gaunt, Jonathan R.

    2017-02-01

    Double parton scattering in proton-proton collisions includes kinematic regions in which two partons inside a proton originate from the perturbative splitting of a single parton. This leads to a double counting problem between single and double hard scattering. We present a solution to this problem, which allows for the definition of double parton distributions as operator matrix elements in a proton, and which can be used at higher orders in perturbation theory. We show how the evaluation of double hard scattering in this framework can provide a rough estimate for the size of the higher-order contributions to single hard scattering that are affected by double counting. In a numeric study, we identify situations in which these higher-order contributions must be explicitly calculated and included if one wants to attain an accuracy at which double hard scattering becomes relevant, and other situations where such contributions may be neglected.

  17. Recent progress with digital coincidence counting

    International Nuclear Information System (INIS)

    Butcher, K.S.A.; Watt, G.C.; Alexiev, D.

    1999-01-01

    Digital Coincidence Counting (DCC) is a new technique, based on the older method of analogue coincidence counting. It has been developed by ANSTO as a faster more reliable means of determining the activity of ionising radiation samples. The technique employs a dual channel analogue to digital converter acquisition system for collecting pulse information from a 4Π beta detector and a NaI(Tl) gamma detector. The digitised pulse information is stored on a high speed hard disk and timing information for both channels is also stored. The data may subsequently be recalled and analysed using software based algorithms. The system is operational and results are now being routinely collected and analysed. Some of the early work is presented for Co-60, Na-22 and Sm-153

  18. Inventory verification measurements using neutron multiplicity counting

    International Nuclear Information System (INIS)

    Ensslin, N.; Foster, L.A.; Harker, W.C.; Krick, M.S.; Langner, D.G.

    1998-01-01

    This paper describes a series of neutron multiplicity measurements of large plutonium samples at the Los Alamos Plutonium Facility. The measurements were corrected for bias caused by neutron energy spectrum shifts and nonuniform multiplication, and are compared with calorimetry/isotopics. The results show that multiplicity counting can increase measurement throughput and yield good verification results for some inventory categories. The authors provide recommendations on the future application of the technique to inventory verification

  19. Counting graphene layers with very slow electrons

    Czech Academy of Sciences Publication Activity Database

    Frank, Luděk; Mikmeková, Eliška; Müllerová, Ilona; Lejeune, M.

    2015-01-01

    Roč. 106, 09 JAN (2015), 013117:1-5 ISSN 0003-6951 R&D Projects: GA TA ČR(CZ) TE01020118; GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : graphene * ultralow energy STEM * counting graphene layers * clean ing of graphene * 2D crystals Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.142, year: 2015

  20. Optimal Planar Orthogonal Skyline Counting Queries

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Larsen, Kasper Green

    2014-01-01

    counting queries, i.e. given a query rectangle R to report the size of the skyline of P\\cap R. We present a data structure for storing n points with integer coordinates having query time O(lg n/lglg n) and space usage O(n). The model of computation is a unit cost RAM with logarithmic word size. We prove...

  1. Total bacterial count and somatic cell count in refrigerated raw milk stored in communal tanks

    Directory of Open Access Journals (Sweden)

    Edmar da Costa Alves

    2014-09-01

    Full Text Available The current industry demand for dairy products with extended shelf life has resulted in new challenges for milk quality maintenance. The processing of milk with high bacterial counts compromises the quality and performance of industrial products. The study aimed to evaluate the total bacteria counts (TBC and somatic cell count (SCC in 768 samples of refrigerated raw milk, from 32 communal tanks. Samples were collected in the first quarter of 2010, 2011, 2012 and 2013 and analyzed by the Laboratory of Milk Quality - LQL. Results showed that 62.5%, 37.5%, 15.6% and 27.1% of the means for TBC in 2010, 2011, 2012 and 2013, respectively, were above the values established by legislation. However, we observed a significant reduction in the levels of total bacterial count (TBC in the studied periods. For somatic cell count, 100% of the means indicated values below 600.000 cells/mL, complying with the actual Brazilian legislation. The values found for the somatic cell count suggests the adoption of effective measures for the sanitary control of the herd. However, the results must be considered with caution as it highlights the need for quality improvements of the raw material until it achieves reliable results effectively.

  2. Bayesian analysis of energy and count rate data for detection of low count rate radioactive sources.

    Science.gov (United States)

    Klumpp, John; Brandl, Alexander

    2015-03-01

    A particle counting and detection system is proposed that searches for elevated count rates in multiple energy regions simultaneously. The system analyzes time-interval data (e.g., time between counts), as this was shown to be a more sensitive technique for detecting low count rate sources compared to analyzing counts per unit interval (Luo et al. 2013). Two distinct versions of the detection system are developed. The first is intended for situations in which the sample is fixed and can be measured for an unlimited amount of time. The second version is intended to detect sources that are physically moving relative to the detector, such as a truck moving past a fixed roadside detector or a waste storage facility under an airplane. In both cases, the detection system is expected to be active indefinitely; i.e., it is an online detection system. Both versions of the multi-energy detection systems are compared to their respective gross count rate detection systems in terms of Type I and Type II error rates and sensitivity.

  3. Metal ion levels and lymphocyte counts

    DEFF Research Database (Denmark)

    Penny, Jeannette Ø; Varmarken, Jens-Erik; Ovesen, Ole

    2013-01-01

    BACKGROUND AND PURPOSE: Wear particles from metal-on-metal arthroplasties are under suspicion for adverse effects both locally and systemically, and the DePuy ASR Hip Resurfacing System (RHA) has above-average failure rates. We compared lymphocyte counts in RHA and total hip arthroplasty (THA) an....../ppb. INTERPRETATION: Circulating T-lymphocyte levels may decline after surgery, regardless of implant type. Metal ions-particularly cobalt-may have a general depressive effect on T- and B-lymphocyte levels. Registered with ClinicalTrials.gov under # NCT01113762.......BACKGROUND AND PURPOSE: Wear particles from metal-on-metal arthroplasties are under suspicion for adverse effects both locally and systemically, and the DePuy ASR Hip Resurfacing System (RHA) has above-average failure rates. We compared lymphocyte counts in RHA and total hip arthroplasty (THA....... RESULTS: The T-lymphocyte counts for both implant types declined over the 2-year period. This decline was statistically significant for CD3(+)CD8(+) in the THA group, with a regression coefficient of -0.04 × 10(9)cells/year (95% CI: -0.08 to -0.01). Regression analysis indicated a depressive effect...

  4. Accuracy in activation analysis: count rate effects

    International Nuclear Information System (INIS)

    Lindstrom, R.M.; Fleming, R.F.

    1980-01-01

    The accuracy inherent in activation analysis is ultimately limited by the uncertainty of counting statistics. When careful attention is paid to detail, several workers have shown that all systematic errors can be reduced to an insignificant fraction of the total uncertainty, even when the statistical limit is well below one percent. A matter of particular importance is the reduction of errors due to high counting rate. The loss of counts due to random coincidence (pulse pileup) in the amplifier and to digitization time in the ADC may be treated as a series combination of extending and non-extending dead times, respectively. The two effects are experimentally distinct. Live timer circuits in commercial multi-channel analyzers compensate properly for ADC dead time for long-lived sources, but not for pileup. Several satisfactory solutions are available, including pileup rejection and dead time correction circuits, loss-free ADCs, and computed corrections in a calibrated system. These methods are sufficiently reliable and well understood that a decaying source can be measured routinely with acceptably small errors at a dead time as high as 20 percent

  5. Automatic vehicle counting system for traffic monitoring

    Science.gov (United States)

    Crouzil, Alain; Khoudour, Louahdi; Valiere, Paul; Truong Cong, Dung Nghy

    2016-09-01

    The article is dedicated to the presentation of a vision-based system for road vehicle counting and classification. The system is able to achieve counting with a very good accuracy even in difficult scenarios linked to occlusions and/or presence of shadows. The principle of the system is to use already installed cameras in road networks without any additional calibration procedure. We propose a robust segmentation algorithm that detects foreground pixels corresponding to moving vehicles. First, the approach models each pixel of the background with an adaptive Gaussian distribution. This model is coupled with a motion detection procedure, which allows correctly location of moving vehicles in space and time. The nature of trials carried out, including peak periods and various vehicle types, leads to an increase of occlusions between cars and between cars and trucks. A specific method for severe occlusion detection, based on the notion of solidity, has been carried out and tested. Furthermore, the method developed in this work is capable of managing shadows with high resolution. The related algorithm has been tested and compared to a classical method. Experimental results based on four large datasets show that our method can count and classify vehicles in real time with a high level of performance (>98%) under different environmental situations, thus performing better than the conventional inductive loop detectors.

  6. Passive hand movements disrupt adults’ counting strategies

    Directory of Open Access Journals (Sweden)

    Ineke eImbo

    2011-09-01

    Full Text Available In the present study, we experimentally tested the role of hand motor circuits in simple-arithmetic strategies. Educated adults solved simple additions (e.g., 8+3 or simple subtractions (e.g., 11–3 while they were required to retrieve the answer from long-term memory (e.g., knowing that 8+3 = 11, to transform the problem by making an intermediate step (e.g., 8+3 = 8+2+1 = 10+1 = 11 or to count one-by-one (e.g., 8+3 = 8…9…10…11. During the process of solving the arithmetic problems, the experimenter did or did not move the participants’ hand on a 4-point matrix. The results show that passive hand movements disrupted the counting strategy while leaving the other strategies unaffected. This pattern of results is in agreement with a procedural account, showing that the involvement of hand motor circuits in adults’ mathematical abilities is reminiscent of finger counting during childhood.

  7. Passive hand movements disrupt adults' counting strategies.

    Science.gov (United States)

    Imbo, Ineke; Vandierendonck, André; Fias, Wim

    2011-01-01

    In the present study, we experimentally tested the role of hand motor circuits in simple-arithmetic strategies. Educated adults solved simple additions (e.g., 8 + 3) or simple subtractions (e.g., 11 - 3) while they were required to retrieve the answer from long-term memory (e.g., knowing that 8 + 3 = 11), to transform the problem by making an intermediate step (e.g., 8 + 3 = 8 + 2 + 1 = 10 + 1 = 11) or to count one-by-one (e.g., 8 + 3 = 8…9…10…11). During the process of solving the arithmetic problems, the experimenter did or did not move the participants' hand on a four-point matrix. The results show that passive hand movements disrupted the counting strategy while leaving the other strategies unaffected. This pattern of results is in agreement with a procedural account, showing that the involvement of hand motor circuits in adults' mathematical abilities is reminiscent of finger counting during childhood.

  8. Decay counting in the age of AMS

    International Nuclear Information System (INIS)

    Arnold, J.R.

    1987-01-01

    Up to the advent of AMS, all the accomplishments of 14 C dating, and the studies of 10 Be and other long-lived radionuclides, were made by low-level decay counting, the technique pioneered by W.F. Libby. It will hardly be news to people at this conference that, while much was accomplished in the three decades when counting prevailed, the world has now changed decisively. I will try to give an account of where low-level counting was 'before the revolution', and of what its usefulness is today. There are still some remarkable examples of its application, the best being the neutrino experiment of Raymond Davis, and its potential successors. Some cosmogenic nuclides, whose half-lives are less than 10 3 yr, are still best measured by decay; this will continue unless the overall ion yield of AMS systems rises markedly from present levels. One long-lived nuclide, 53 Mn, is still best measured by neutron activation as 312-day 54 Mn, but this may not continue. (orig.)

  9. Theory and application of Cerenkov counting

    Energy Technology Data Exchange (ETDEWEB)

    Ross, H.H.

    1976-01-01

    The production of Cherenkov radiation by charged particles moving through a transparent medium (the Cherenkov generator) is a strictly physical process that is virtually independent of the chemistry of the medium. Thus, it is possible to calculate easily all of the important parameters of the Cherenkov process such as excitation threshold, emission intensity, spectral distribution, directional characteristics, and time response. The results of many of these physical effects are unknown in conventional liquid scintillation spectroscopy and, therefore, many unique assay techniques have been developed as a result of their consideration. This paper discusses the theoretical basis of the Cherenkov process, explores the unusual characteristics of the phenomenon, and demonstrates how these unusual characteristics can be used to develop equally unusual counting methodologies. Particular emphasis is directed toward an analysis of published data (obtained with conventional liquid scintillation instrumentation) that would be difficult or impossible to obtain with other counting techniques. Also discussed is a new type of sample vial that uses an isolated waveshifting system. The device was specifically designed for Cherenkov counting.

  10. Decay counting in the age of AMS

    International Nuclear Information System (INIS)

    Arnold, J.R.

    1987-01-01

    Up to the advent of AMS, all the accomplishments of 14 C dating, and the studies of 10 Be and other long-lived radionuclides, were made by low-level decay counting, the technique pioneered by W.F. Libby. It will hardly be news to people at this conference that, while much was accomplished in the three decades when counting prevailed, the world has now changed decisively. He will try to give an account of where low-level counting was before the revolution, and of what its usefulness is today. There are still some remarkable examples of its application, the best being the neutrino experiment of Raymond Davis, and its potential successors. Some cosmogenic nuclides, whose half-lives are less than 10 3 yr, are still best measured by decay; this will continue unless the overall ion yield of AMS systems rises markedly from present levels. One long-lived nuclide, 53 Mn, is still best measured by neutron activation as 312-day 54 Mn, but this may not continue

  11. Manifold-Based Visual Object Counting.

    Science.gov (United States)

    Wang, Yi; Zou, Yuexian; Wang, Wenwu

    2018-07-01

    Visual object counting (VOC) is an emerging area in computer vision which aims to estimate the number of objects of interest in a given image or video. Recently, object density based estimation method is shown to be promising for object counting as well as rough instance localization. However, the performance of this method tends to degrade when dealing with new objects and scenes. To address this limitation, we propose a manifold-based method for visual object counting (M-VOC), based on the manifold assumption that similar image patches share similar object densities. Firstly, the local geometry of a given image patch is represented linearly by its neighbors using a predefined patch training set, and the object density of this given image patch is reconstructed by preserving the local geometry using locally linear embedding. To improve the characterization of local geometry, additional constraints such as sparsity and non-negativity are also considered via regularization, nonlinear mapping, and kernel trick. Compared with the state-of-the-art VOC methods, our proposed M-VOC methods achieve competitive performance on seven benchmark datasets. Experiments verify that the proposed M-VOC methods have several favorable properties, such as robustness to the variation in the size of training dataset and image resolution, as often encountered in real-world VOC applications.

  12. A mind you can count on: validating breath counting as a behavioral measure of mindfulness

    Directory of Open Access Journals (Sweden)

    Daniel B Levinson

    2014-10-01

    Full Text Available Mindfulness practice of present moment awareness promises many benefits, but has eluded rigorous behavioral measurement. To date, research has relied on self-reported mindfulness or heterogeneous mindfulness trainings to infer skillful mindfulness practice and its effects. In four independent studies with over 400 total participants, we present the first construct validation of a behavioral measure of mindfulness, breath counting. We found it was reliable, correlated with self-reported mindfulness, differentiated long-term meditators from age-matched controls, and was distinct from sustained attention and working memory measures. In addition, we employed breath counting to test the nomological network of mindfulness. As theorized, we found skill in breath counting associated with more meta-awareness, less mind wandering, better mood, and greater nonattachment (i.e. less attentional capture by distractors formerly paired with reward. We also found in a randomized online training study that 4 weeks of breath counting training improved mindfulness and decreased mind wandering relative to working memory training and no training controls. Together, these findings provide the first evidence for breath counting as a behavioral measure of mindfulness.

  13. Determination of the flux per electron-volt at the resonance energy of gold by means op thick gold detectors (1962); Determination des flux par electron-volt a l'energie de resonance de l'or a l'aide de detecteurs d'or epais. (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Brisbois, J; Fogagnolo, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1962-07-01

    We calculated the coefficients which allow determining a neutron flux at 5 eV by means of 2/10 mm thick gold detectors on Geiger-Muller counter assemblies. These coefficients were obtained comparing the thick detectors with the thin ones. (authors) [French] Nous avons calcule les coefficients permettant de determiner le flux de neutrons a 5 eV a partir de comptages de detecteurs d'or de 2/10 mm d'epaisseur sur des groupes a compteur de Geiger-Muller. Ces coefficients ont ete obtenus en comparant les detecteurs epais avec des detecteurs minces. (auteurs)

  14. Short communication: Repeatability of differential goat bulk milk culture and associations with somatic cell count, total bacterial count, and standard plate count.

    Science.gov (United States)

    Koop, G; Dik, N; Nielen, M; Lipman, L J A

    2010-06-01

    The aims of this study were to assess how different bacterial groups in bulk milk are related to bulk milk somatic cell count (SCC), bulk milk total bacterial count (TBC), and bulk milk standard plate count (SPC) and to measure the repeatability of bulk milk culturing. On 53 Dutch dairy goat farms, 3 bulk milk samples were collected at intervals of 2 wk. The samples were cultured for SPC, coliform count, and staphylococcal count and for the presence of Staphylococcus aureus. Furthermore, SCC (Fossomatic 5000, Foss, Hillerød, Denmark) and TBC (BactoScan FC 150, Foss) were measured. Staphylococcal count was correlated to SCC (r=0.40), TBC (r=0.51), and SPC (r=0.53). Coliform count was correlated to TBC (r=0.33), but not to any of the other variables. Staphylococcus aureus did not correlate to SCC. The contribution of the staphylococcal count to the SPC was 31%, whereas the coliform count comprised only 1% of the SPC. The agreement of the repeated measurements was low. This study indicates that staphylococci in goat bulk milk are related to SCC and make a significant contribution to SPC. Because of the high variation in bacterial counts, repeated sampling is necessary to draw valid conclusions from bulk milk culturing. 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. Quantitative clinical uptake measurements using conjugate counting

    International Nuclear Information System (INIS)

    Lathrop, K.A.; Bartlett, R.D.; Chen, C.T.; Chou, J.S.; Faulhaber, P.F.; Harper, P.V.; Stark, V.J.

    1986-01-01

    While the use of conjugate counting for determination of organ uptake in human subjects has been extensively described, in the present study the determination of the organ uptake of ortho-iodohippurate presented several opportunities for validation of the in vivo counting data. Ortho-iodohippurate is distributed in the extracellular space, is largely extracted on each pass through the kidneys, and is not significantly deiodinated in vivo. Thus, the kidney uptake rate should be proportional to the blood level, the appearance rate of activity in the bladder is equal to the disappearance rate from the kidneys, and direct measurement of activity in the urine after voiding provides an internal standard for imaging measurements of bladder activity. Since the activity levels in the kidneys, bladder, and remainder of the body changed fairly rapidly, especially in the first 20 to 30 minutes following injection, posterior images of the trunk including kidneys and bladder were obtained continuously using a gamma camera fitted with a diverging collimator for 30 minutes and then at intervals for several hours. Simultaneous conjugate counting determinations were made using a whole body scanning system previously described at these meetings. Imaging data corrected for decay and adjacent background were fitted by least squares methods to curves representing a sum of exponentials, and the curves were normalized to the conjugate uptake measurements. The uptake curves of the kidneys and bladder matched well with the direct measurements of the urinary excretion. Data were collected in 16 normal subjects, and the estimated absorbed dose was calculated for the kidneys, the bladder and the remainder of the body for seven radioisotopes of iodine. 4 references, 6 figures, 2 tables

  16. Performance of gamma spectrometry counting system

    International Nuclear Information System (INIS)

    Yii Mei Wo; Maziah Mahmud

    2007-01-01

    Gamma spectrometry counting system widely used as tool to measure qualitative and quantitative gamma-ray emitters in a sample. Container size, sample to detector distance, sample volume are well known factors that affecting the quality of measurement. However, factor such as the age of the system was not been reported. Therefore, the objective of this study is to find out how the age factor affecting the quality of the measurement. From this study, it is found that when the age of the system increased, the system tends to have higher lower limit of detection and poorer linearity showing that age factor do affecting the quality of measurement. (Author)

  17. Statistical Methods for Unusual Count Data

    DEFF Research Database (Denmark)

    Guthrie, Katherine A.; Gammill, Hilary S.; Kamper-Jørgensen, Mads

    2016-01-01

    microchimerism data present challenges for statistical analysis, including a skewed distribution, excess zero values, and occasional large values. Methods for comparing microchimerism levels across groups while controlling for covariates are not well established. We compared statistical models for quantitative...... microchimerism values, applied to simulated data sets and 2 observed data sets, to make recommendations for analytic practice. Modeling the level of quantitative microchimerism as a rate via Poisson or negative binomial model with the rate of detection defined as a count of microchimerism genome equivalents per...

  18. Applications of low level liquid scintillation counting

    International Nuclear Information System (INIS)

    Noakes, J.E.

    1983-01-01

    Low level liquid scintillation counting is reviewed in terms of its present use and capabilities for measuring low activity samples. New areas of application of the method are discussed with special interest directed to the food industry and environmental monitoring. Advantages offered in the use of a low background liquid scintillation counter for the nuclear power industry and nuclear navy are discussed. Attention is drawn to the need for commercial development of such instrumentation to enable wider use of the method. A user clientele is suggested as is the required technology to create such a counter

  19. Neutron coincidence counting with digital signal processing

    International Nuclear Information System (INIS)

    Bagi, Janos; Dechamp, Luc; Dransart, Pascal; Dzbikowicz, Zdzislaw; Dufour, Jean-Luc; Holzleitner, Ludwig; Huszti, Joseph; Looman, Marc; Marin Ferrer, Montserrat; Lambert, Thierry; Peerani, Paolo; Rackham, Jamie; Swinhoe, Martyn; Tobin, Steve; Weber, Anne-Laure; Wilson, Mark

    2009-01-01

    Neutron coincidence counting is a widely adopted nondestructive assay (NDA) technique used in nuclear safeguards to measure the mass of nuclear material in samples. Nowadays, most neutron-counting systems are based on the original-shift-register technology, like the (ordinary or multiplicity) Shift-Register Analyser. The analogue signal from the He-3 tubes is processed by an amplifier/single channel analyser (SCA) producing a train of TTL pulses that are fed into an electronic unit that performs the time- correlation analysis. Following the suggestion of the main inspection authorities (IAEA, Euratom and the French Ministry of Industry), several research laboratories have started to study and develop prototypes of neutron-counting systems with PC-based processing. Collaboration in this field among JRC, IRSN and LANL has been established within the framework of the ESARDA-NDA working group. Joint testing campaigns have been performed in the JRC PERLA laboratory, using different equipment provided by the three partners. One area of development is the use of high-speed PCs and pulse acquisition electronics that provide a time stamp (LIST-Mode Acquisition) for every digital pulse. The time stamp data can be processed directly during acquisition or saved on a hard disk. The latter method has the advantage that measurement data can be analysed with different values for parameters like predelay and gate width, without repeating the acquisition. Other useful diagnostic information, such as die-away time and dead time, can also be extracted from this stored data. A second area is the development of 'virtual instruments.' These devices, in which the pulse-processing system can be embedded in the neutron counter itself and sends counting data to a PC, can give increased data-acquisition speeds. Either or both of these developments could give rise to the next generation of instrumentation for improved practical neutron-correlation measurements. The paper will describe the

  20. Applied categorical and count data analysis

    CERN Document Server

    Tang, Wan; Tu, Xin M

    2012-01-01

    Introduction Discrete Outcomes Data Source Outline of the BookReview of Key Statistical ResultsSoftwareContingency Tables Inference for One-Way Frequency TableInference for 2 x 2 TableInference for 2 x r TablesInference for s x r TableMeasures of AssociationSets of Contingency Tables Confounding Effects Sets of 2 x 2 TablesSets of s x r TablesRegression Models for Categorical Response Logistic Regression for Binary ResponseInference about Model ParametersGoodness of FitGeneralized Linear ModelsRegression Models for Polytomous ResponseRegression Models for Count Response Poisson Regression Mode

  1. Compositions and process for liquid scintillation counting

    International Nuclear Information System (INIS)

    Kauffman, J.M.

    1976-01-01

    Liquid scintillation counting compositions which include certain polyethoxylated poly(oxypropylene) emulsifiers allow stable dispersion of aqueous or other samples merely by shaking. Preferred are mixtures of such emulsifiers, which give homogeneous, monophasic-appearing dispersions over wide ranges of temperature and aqueous sample content. Certain of these emulsifiers, without being mixed, are of particular advantage when used in analysis of samples obtained through radioimmunoassay techniques, which are extremely difficult to disperse. Certain of these emulsifiers, also without being mixed, uniformly give homogeneous, monophasic appearing aqueous couting samples over much wider ranges of aqueous sample content and temperature than prior sample emulsifiers

  2. Compositions and process for liquid scintillation counting

    International Nuclear Information System (INIS)

    Kauffman, J.M.

    1978-01-01

    Liquid scintillation compositions which include certain polyethoxylated poly(oxypropylene) emulsifiers allow stable dispersion of aqueous or other samples merely by shaking. Preferred are mixtures of such emulsifiers, which give homogeneous, monophasic-appearing dispersions over wide ranges of temperature and aqueous sample content. Certain of these emulsifiers, without being mixed, are of particular advantage when used in analysis of samples obtained through radioimmunoassay techniques, which are extremely difficult to disperse. Certain of these emulsifiers, also without being mixed, uniformly give homogeneous, monophasic appearing aqueous counting samples over much wider ranges of aqueous sample content and temperature than prior sample emulsifiers

  3. Statistical data filtration in neutron coincidence counting

    International Nuclear Information System (INIS)

    Beddingfield, D.H.; Menlove, H.O.

    1992-11-01

    We assessed the effectiveness of statistical data filtration to minimize the contribution of matrix materials in 200-ell drums to the nondestructive assay of plutonium. Those matrices were examined: polyethylene, concrete, aluminum, iron, cadmium, and lead. Statistical filtration of neutron coincidence data improved the low-end sensitivity of coincidence counters. Spurious data arising from electrical noise, matrix spallation, and geometric effects were smoothed in a predictable fashion by the statistical filter. The filter effectively lowers the minimum detectable mass limit that can be achieved for plutonium assay using passive neutron coincidence counting

  4. Strange Curves, Counting Rabbits, & Other Mathematical Explorations

    CERN Document Server

    Ball, Keith

    2011-01-01

    How does mathematics enable us to send pictures from space back to Earth? Where does the bell-shaped curve come from? Why do you need only 23 people in a room for a 50/50 chance of two of them sharing the same birthday? In Strange Curves, Counting Rabbits, and Other Mathematical Explorations, Keith Ball highlights how ideas, mostly from pure math, can answer these questions and many more. Drawing on areas of mathematics from probability theory, number theory, and geometry, he explores a wide range of concepts, some more light-hearted, others central to the development of the field and used dai

  5. Particle Count Limits Recommendation for Aviation Fuel

    Science.gov (United States)

    2015-10-05

    Particle Counter Methodology • Particle counts are taken utilizing calibration methodologies and standardized cleanliness code ratings – ISO 11171 – ISO...Limits Receipt Vehicle Fuel Tank Fuel Injector Aviation Fuel DEF (AUST) 5695B 18/16/13 Parker 18/16/13 14/10/7 Pamas / Parker / Particle Solutions 19/17...12 U.S. DOD 19/17/14/13* Diesel Fuel World Wide Fuel Charter 5th 18/16/13 DEF (AUST) 5695B 18/16/13 Caterpillar 18/16/13 Detroit Diesel 18/16/13 MTU

  6. CalCOFI Larvae Counts, Scientific Names CI to CO

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  7. CalCOFI Larvae Counts, Scientific Names DH to EC

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  8. CalCOFI Larvae Counts, Scientific Names TF to U

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  9. CalCOFI Larvae Counts, Scientific Names HJ to ID

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  10. CalCOFI Larvae Counts, Scientific Names AN to AR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  11. CalCOFI Larvae Counts, Scientific Names SJ to ST

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  12. CalCOFI Larvae Counts, Scientific Names CP to DE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  13. CalCOFI Larvae Counts, Scientific Names C to CE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  14. CalCOFI Larvae Counts, Scientific Names EV to GN

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  15. CalCOFI Larvae Counts, Scientific Names V to Z

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  16. CalCOFI Larvae Counts, Scientific Names ED to EU

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  17. CalCOFI Larvae Counts, Scientific Names SD to SI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  18. CalCOFI Larvae Counts, Scientific Names MB to MO

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  19. CalCOFI Larvae Counts, Scientific Names LJ to MA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  20. CalCOFI Larvae Counts, Scientific Names AS to BA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  1. CalCOFI Larvae Counts, Scientific Names SB to SC

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  2. CalCOFI Larvae Counts, Scientific Names MP to NA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  3. CalCOFI Larvae Counts, Scientific Names SU to TE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  4. CalCOFI Larvae Counts, Scientific Names PL to PO

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  5. CalCOFI Larvae Counts, Scientific Names IE to LA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  6. CalCOFI Larvae Counts, Scientific Names A to AM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  7. CalCOFI Larvae Counts, Scientific Names HB to HI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  8. CalCOFI Larvae Counts, Scientific Names OM to OX

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  9. CalCOFI Larvae Counts, Scientific Names Q to SA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  10. CalCOFI Larvae Counts, Scientific Names PP to PZ

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  11. CalCOFI Larvae Counts, Scientific Names GO to HA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  12. CalCOFI Larvae Counts, Scientific Names NB to OL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  13. CalCOFI Larvae Counts, Scientific Names LB to LI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  14. CalCOFI Larvae Counts, Scientific Names BCE to BZ

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  15. CalCOFI Larvae Counts, Scientific Names CD to CH

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  16. Alaska Steller sea lion Count Database (Non-pups)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This database contains counts of adult and juvenile (non-pup) Steller sea lions on rookeries and haulouts in Alaska made between 1904 and 2015. Non-pup counts have...

  17. Change-Point Methods for Overdispersed Count Data

    National Research Council Canada - National Science Library

    Wilken, Brian A

    2007-01-01

    .... Although the Poisson model is often used to model count data, the two-parameter gamma-Poisson mixture parameterization of the negative binomial distribution is often a more adequate model for overdispersed count data...

  18. CalCOFI Larvae Counts, Scientific Names OY to PI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  19. Genome Replikin Count Predicts Increased Infectivity/Lethality of Viruses

    OpenAIRE

    Samuel Bogoch; Elenore S. Bogoch

    2012-01-01

    The genomes of all groups of viruses whose sequences are listed on Pubmed, specimens since 1918, analyzed by a software from Bioradar UK Ltd., contain Replikins which range in concentration from a Replikin Count (number of Replikins per 100 amino acids) of less than 1 to 30 (see accompanying communications for higher Counts in tuberculosis, malaria, and cancer, associated with higher lethality). Counts of less than 4.0 were found in ‘resting’ virus states; Counts greater than 4....

  20. Determining Gate Count Reliability in a Library Setting

    OpenAIRE

    Jeffrey Phillips

    2016-01-01

    Objective – Patron counts are a common form of measurement for library assessment. To develop accurate library statistics, it is necessary to determine any differences between various counting devices. A yearlong comparison between card reader turnstiles and laser gate counters in a university library sought to offer a standard percentage of variance and provide suggestions to increase the precision of counts. Methods – The collection of library exit counts identified the differences be...

  1. Automated vehicle counting using image processing and machine learning

    Science.gov (United States)

    Meany, Sean; Eskew, Edward; Martinez-Castro, Rosana; Jang, Shinae

    2017-04-01

    Vehicle counting is used by the government to improve roadways and the flow of traffic, and by private businesses for purposes such as determining the value of locating a new store in an area. A vehicle count can be performed manually or automatically. Manual counting requires an individual to be on-site and tally the traffic electronically or by hand. However, this can lead to miscounts due to factors such as human error A common form of automatic counting involves pneumatic tubes, but pneumatic tubes disrupt traffic during installation and removal, and can be damaged by passing vehicles. Vehicle counting can also be performed via the use of a camera at the count site recording video of the traffic, with counting being performed manually post-recording or using automatic algorithms. This paper presents a low-cost procedure to perform automatic vehicle counting using remote video cameras with an automatic counting algorithm. The procedure would utilize a Raspberry Pi micro-computer to detect when a car is in a lane, and generate an accurate count of vehicle movements. The method utilized in this paper would use background subtraction to process the images and a machine learning algorithm to provide the count. This method avoids fatigue issues that are encountered in manual video counting and prevents the disruption of roadways that occurs when installing pneumatic tubes

  2. Differences in meristic counts of the genus Clarias (pisces: clariidae ...

    African Journals Online (AJOL)

    Specific differences in meristic counts were exhibited in both the anal fin ray count and the vertebral count in the clariids of Anambra rver, Nigeria. There was a close numerical relationship between the number of anal fin rays and the number of vertebrae. The present study further justifies the taxonomic importance of anal fin ...

  3. Point Count Length and Detection of Forest Neotropical Migrant Birds

    Science.gov (United States)

    Deanna K. Dawson; David R. Smith; Chandler S. Robbins

    1995-01-01

    Comparisons of bird abundances among years or among habitats assume that the rates at which birds are detected and counted are constant within species. We use point count data collected in forests of the Mid-Atlantic states to estimate detection probabilities for Neotropical migrant bird species as a function of count length. For some species, significant differences...

  4. Analysis of Parasite and Other Skewed Counts

    Science.gov (United States)

    Alexander, Neal

    2012-01-01

    Objective To review methods for the statistical analysis of parasite and other skewed count data. Methods Statistical methods for skewed count data are described and compared, with reference to those used over a ten year period of Tropical Medicine and International Health. Two parasitological datasets are used for illustration. Results Ninety papers were identified, 89 with descriptive and 60 with inferential analysis. A lack of clarity is noted in identifying measures of location, in particular the Williams and geometric mean. The different measures are compared, emphasizing the legitimacy of the arithmetic mean for skewed data. In the published papers, the t test and related methods were often used on untransformed data, which is likely to be invalid. Several approaches to inferential analysis are described, emphasizing 1) non-parametric methods, while noting that they are not simply comparisons of medians, and 2) generalized linear modelling, in particular with the negative binomial distribution. Additional methods, such as the bootstrap, with potential for greater use are described. Conclusions Clarity is recommended when describing transformations and measures of location. It is suggested that non-parametric methods and generalized linear models are likely to be sufficient for most analyses. PMID:22943299

  5. Counted Sb donors in Si quantum dots

    Science.gov (United States)

    Singh, Meenakshi; Pacheco, Jose; Bielejec, Edward; Perry, Daniel; Ten Eyck, Gregory; Bishop, Nathaniel; Wendt, Joel; Luhman, Dwight; Carroll, Malcolm; Lilly, Michael

    2015-03-01

    Deterministic control over the location and number of donors is critical for donor spin qubits in semiconductor based quantum computing. We have developed techniques using a focused ion beam and a diode detector integrated next to a silicon MOS single electron transistor to gain such control. With the diode detector operating in linear mode, the numbers of ions implanted have been counted and single ion implants have been detected. Poisson statistics in the number of ions implanted have been observed. Transport measurements performed on samples with counted number of implants have been performed and regular coulomb blockade and charge offsets observed. The capacitances to various gates are found to be in agreement with QCAD simulations for an electrostatically defined dot. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. The work was supported by Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  6. Gauge invariance and degree of freedom count

    International Nuclear Information System (INIS)

    Henneaux, M.; Universite Libre de Bruxelles; Teitelboim, C.; Texas Univ., Austin; Zanelli, J.; Chile Univ., Santiago. Dept. de Fisica)

    1990-01-01

    The precise relation between the gauge transformations in lagrangian and hamiltonian form is derived for any gauge theory. It is found that in order to define a lagrangian gauge symmetry, the coefficients of the first class constraints in the hamiltonian generator of gauge transformations must obey a set of differential equations. Those equations involve, in general, the Lagrange multipliers. Their solution contains as many arbitrary functions of time as there are primary first class constraints. If n is the number of generations of constraints (primary, secondary, tertiary...), the arbitrary functions appear in the general solution together with their successive time derivatives up to order n-1. The analysis yields as by-products: (i) a systematic way to derive all the gauge symmetries of a given lagrangian; (ii) a precise criterion for counting the physical degrees of freedom of a gauge theory directly from the form of gauge transformations in lagrangian form. This last part is illustrated by means of examples. The BRST analog of the counting of physical degrees of freedom is also discussed. (orig.)

  7. Robustifying Bayesian nonparametric mixtures for count data.

    Science.gov (United States)

    Canale, Antonio; Prünster, Igor

    2017-03-01

    Our motivating application stems from surveys of natural populations and is characterized by large spatial heterogeneity in the counts, which makes parametric approaches to modeling local animal abundance too restrictive. We adopt a Bayesian nonparametric approach based on mixture models and innovate with respect to popular Dirichlet process mixture of Poisson kernels by increasing the model flexibility at the level both of the kernel and the nonparametric mixing measure. This allows to derive accurate and robust estimates of the distribution of local animal abundance and of the corresponding clusters. The application and a simulation study for different scenarios yield also some general methodological implications. Adding flexibility solely at the level of the mixing measure does not improve inferences, since its impact is severely limited by the rigidity of the Poisson kernel with considerable consequences in terms of bias. However, once a kernel more flexible than the Poisson is chosen, inferences can be robustified by choosing a prior more general than the Dirichlet process. Therefore, to improve the performance of Bayesian nonparametric mixtures for count data one has to enrich the model simultaneously at both levels, the kernel and the mixing measure. © 2016, The International Biometric Society.

  8. Data process of liquid scintillation counting

    International Nuclear Information System (INIS)

    Ishikawa, Hiroaki; Kuwajima, Susumu.

    1975-01-01

    The use of liquid scintillation counting system has been significantly spread because automatic sample changers and printers have recently come to be incorporated. However, the system will be systematized completely if automatic data processing and the sample preparation of radioactive materials to be measured are realized. Dry or wet oxidation method is applied to the sample preparation when radioactive materials are hard to dissolve into scintillator solution. Since these several years, the automatic sample combustion system, in which the dry oxidation is automated, has been rapidly spread and serves greatly to labor saving. Since the printers generally indicate only counted number, data processing system has been developed, and speeded up calculating process, which automatically corrects quenching of samples for obtaining the final radioactivity required. The data processing system is roughly divided into on-line and off-line systems according to whether computers are connected directly or indirectly, while its hardware is classified to input, calculating and output devices. Also, the calculation to determine sample activity by external standard method is explained. (Wakatsuki, Y.)

  9. Language and counting: Some recent results

    Science.gov (United States)

    Bell, Garry

    1990-02-01

    It has long been recognised that the language of mathematics is an important variable in the learning of mathematics, and there has been useful work in isolating and describing the linkage. Steffe and his co-workers at Georgia, for example, (Steffe, von Glasersfeld, Richardson and Cobb, 1983) have suggested that young children may construct verbal countable items to count objects which are hidden from their view. Although there has been a surge of research interest in counting and early childhood mathematics, and in cultural differences in mathematics attainment, there has been little work reported on the linkage between culture as exemplified by language, and initial concepts of numeration. This paper reports on some recent clinical research with kindergarten children of European and Asian background in Australia and America. The research examines the influence that number naming grammar appears to have on young children's understandings of two-digit numbers and place value. It appears that Transparent Standard Number Word Sequences such as Japanese, Chinese and Vietnamese which follow the numerical representation pattern by naming tens and units in order ("two tens three"), may be associated with distinctive place value concepts which may support sophisticated mental algorithms.

  10. Photon Counting Using Edge-Detection Algorithm

    Science.gov (United States)

    Gin, Jonathan W.; Nguyen, Danh H.; Farr, William H.

    2010-01-01

    New applications such as high-datarate, photon-starved, free-space optical communications require photon counting at flux rates into gigaphoton-per-second regimes coupled with subnanosecond timing accuracy. Current single-photon detectors that are capable of handling such operating conditions are designed in an array format and produce output pulses that span multiple sample times. In order to discern one pulse from another and not to overcount the number of incoming photons, a detection algorithm must be applied to the sampled detector output pulses. As flux rates increase, the ability to implement such a detection algorithm becomes difficult within a digital processor that may reside within a field-programmable gate array (FPGA). Systems have been developed and implemented to both characterize gigahertz bandwidth single-photon detectors, as well as process photon count signals at rates into gigaphotons per second in order to implement communications links at SCPPM (serial concatenated pulse position modulation) encoded data rates exceeding 100 megabits per second with efficiencies greater than two bits per detected photon. A hardware edge-detection algorithm and corresponding signal combining and deserialization hardware were developed to meet these requirements at sample rates up to 10 GHz. The photon discriminator deserializer hardware board accepts four inputs, which allows for the ability to take inputs from a quadphoton counting detector, to support requirements for optical tracking with a reduced number of hardware components. The four inputs are hardware leading-edge detected independently. After leading-edge detection, the resultant samples are ORed together prior to deserialization. The deserialization is performed to reduce the rate at which data is passed to a digital signal processor, perhaps residing within an FPGA. The hardware implements four separate analog inputs that are connected through RF connectors. Each analog input is fed to a high-speed 1

  11. Improving EWMA Plans for Detecting Unusual Increases in Poisson Counts

    Directory of Open Access Journals (Sweden)

    R. S. Sparks

    2009-01-01

    adaptive exponentially weighted moving average (EWMA plan is developed for signalling unusually high incidence when monitoring a time series of nonhomogeneous daily disease counts. A Poisson transitional regression model is used to fit background/expected trend in counts and provides “one-day-ahead” forecasts of the next day's count. Departures of counts from their forecasts are monitored. The paper outlines an approach for improving early outbreak data signals by dynamically adjusting the exponential weights to be efficient at signalling local persistent high side changes. We emphasise outbreak signals in steady-state situations; that is, changes that occur after the EWMA statistic had run through several in-control counts.

  12. Validity of total leucocytes count and neutrophil count (differential leucocytes) in diagnosing suspected acute appendicitis

    International Nuclear Information System (INIS)

    Anwar, M.W.; Abid, I.

    2012-01-01

    Objective: To compare the diagnostic accuracy of Total Leucocytes Count (TLC) with Neutrophil count; Differential Leucocytes Count (DLC) in diagnosing cases of suspected acute appendicitis. Study design: Validation study. Place and duration of the study: Department of Surgery, Combined Military Hospital (CMH) Rawalpindi, from April 2008 to October 2008. Method: A total of 100 patients of Pain right iliac fossae who underwent appendicectomy were included. Detailed history of all the patients was taken for pain in right lower abdomen, its severity, its nature, relieving or provoking factors. Clinical examination was done in detail. Total and Differential Leucocytes Count was done. Every patient's appendix was examined grossly after appendicectomy for evidence of appendicitis. Diagnostic measures of TLC and DLC were calculated by standard formulas. Results: Sensitivity and specificity of TLC is 86.9% and 81.25% respectively and that of DLC is 82% and 68.75% respectively. Accuracy was 86% for TLC and 80% for DLC. Conclusion: TLC is more sensitive, specific and accurate test as compared to DLC and it should be used as diagnostic aid for suspected acute appendicitis cases. (author)

  13. Modeling Repeated Count Data : Some Extensions of the Rasch Poisson Counts Model

    NARCIS (Netherlands)

    van Duijn, M.A.J.; Jansen, Margo

    1995-01-01

    We consider data that can be summarized as an N X K table of counts-for example, test data obtained by administering K tests to N subjects. The cell entries y(ij) are assumed to be conditionally independent Poisson-distributed random variables, given the NK Poisson intensity parameters mu(ij). The

  14. Analysis of General Power Counting Rules in Effective Field Theory

    CERN Document Server

    Gavela, B M; Manohar, A V; Merlo, L

    2016-01-01

    We derive the general counting rules for a quantum effective field theory (EFT) in $\\mathsf{d}$ dimensions. The rules are valid for strongly and weakly coupled theories, and predict that all kinetic energy terms are canonically normalized. They determine the energy dependence of scattering cross sections in the range of validity of the EFT expansion. The size of cross sections is controlled by the $\\Lambda$ power counting of EFT, not by chiral counting, even for chiral perturbation theory ($\\chi$PT). The relation between $\\Lambda$ and $f$ is generalized to $\\mathsf{d}$ dimensions. We show that the naive dimensional analysis $4\\pi$ counting is related to $\\hbar$ counting. The EFT counting rules are applied to $\\chi$PT, to Standard Model EFT and to the non-trivial case of Higgs EFT, which combines the $\\Lambda$ and chiral counting rules within a single theory.

  15. Design and development of multiple sample counting setup

    International Nuclear Information System (INIS)

    Rath, D.P.; Murali, S.; Babu, D.A.R.

    2010-01-01

    Full text: The analysis of active samples on regular basis for ambient air activity and floor contamination from radio chemical lab accounts for major chunk of the operational activity in Health Physicist's responsibility. The requirement for daily air sample analysis on immediate counting and delayed counting from various labs in addition to samples of smear swipe check of lab led to the urge for development of system that could cater multiple sample analysis in a time programmed manner on a single sample loading. A multiple alpha/beta counting system for counting was designed and fabricated. It has arrangements for loading 10 samples in slots in order, get counted in a time programmed manner with results displayed and records maintained in PC. The paper describes the design and development of multiple sample counting setup presently in use at the facility has resulted in reduction of man-hour consumption in counting and recording of the results

  16. Correction for decay during counting in gamma spectrometry

    International Nuclear Information System (INIS)

    Nir-El, Y.

    2013-01-01

    A basic result in gamma spectrometry is the count rate of a relevant peak. Correction for decay during counting and expressing the count rate at the beginning of the measurement can be done by a multiplicative factor that is derived from integrating the count rate over time. The counting time substituted in this factor must be the live time, whereas the use of the real-time is an error that underestimates the count rate by about the dead-time (DT) (in percentage). This error of underestimation of the count rate is corroborated in the measurement of a nuclide with a high DT. The present methodology is not applicable in systems that include a zero DT correction function. (authors)

  17. Relationship between salivary flow rates and Candida albicans counts.

    Science.gov (United States)

    Navazesh, M; Wood, G J; Brightman, V J

    1995-09-01

    Seventy-one persons (48 women, 23 men; mean age, 51.76 years) were evaluated for salivary flow rates and Candida albicans counts. Each person was seen on three different occasions. Samples of unstimulated whole, chewing-stimulated whole, acid-stimulated parotid, and candy-stimulated parotid saliva were collected under standardized conditions. An oral rinse was also obtained and evaluated for Candida albicans counts. Unstimulated and chewing-stimulated whole flow rates were negatively and significantly (p Candida counts. Unstimulated whole saliva significantly (p Candida counts of 0 versus or = 500 count. Differences in stimulated parotid flow rates were not significant among different levels of Candida counts. The results of this study reveal that whole saliva is a better predictor than parotid saliva in identification of persons with high Candida albicans counts.

  18. Equivalence of truncated count mixture distributions and mixtures of truncated count distributions.

    Science.gov (United States)

    Böhning, Dankmar; Kuhnert, Ronny

    2006-12-01

    This article is about modeling count data with zero truncation. A parametric count density family is considered. The truncated mixture of densities from this family is different from the mixture of truncated densities from the same family. Whereas the former model is more natural to formulate and to interpret, the latter model is theoretically easier to treat. It is shown that for any mixing distribution leading to a truncated mixture, a (usually different) mixing distribution can be found so that the associated mixture of truncated densities equals the truncated mixture, and vice versa. This implies that the likelihood surfaces for both situations agree, and in this sense both models are equivalent. Zero-truncated count data models are used frequently in the capture-recapture setting to estimate population size, and it can be shown that the two Horvitz-Thompson estimators, associated with the two models, agree. In particular, it is possible to achieve strong results for mixtures of truncated Poisson densities, including reliable, global construction of the unique NPMLE (nonparametric maximum likelihood estimator) of the mixing distribution, implying a unique estimator for the population size. The benefit of these results lies in the fact that it is valid to work with the mixture of truncated count densities, which is less appealing for the practitioner but theoretically easier. Mixtures of truncated count densities form a convex linear model, for which a developed theory exists, including global maximum likelihood theory as well as algorithmic approaches. Once the problem has been solved in this class, it might readily be transformed back to the original problem by means of an explicitly given mapping. Applications of these ideas are given, particularly in the case of the truncated Poisson family.

  19. Counting and Arithmetic of the Inca

    Directory of Open Access Journals (Sweden)

    Ximena Catepillán

    2012-08-01

    Full Text Available The Inca Empire - the greatest pre-Columbian empire on the American continent - extended from Ecuador to central Chile for more than five thousand miles. Its capital was Cuzco established in the high Peruvian Andes. This highly advanced civilization developed a counting system used to run the empire - in particular, to build the 14,000 mile road structure and monumental architecture. Some of the algorithms believed to be used by the Inca to do computations using a yupana, an ancient calculating device, will be presented, as well as classroom activities for the course “Mathematics in Non-European Cultures” for non Mathematics and Science majors offered at Millersville University of Pennsylvania.

  20. Robust small area prediction for counts.

    Science.gov (United States)

    Tzavidis, Nikos; Ranalli, M Giovanna; Salvati, Nicola; Dreassi, Emanuela; Chambers, Ray

    2015-06-01

    A new semiparametric approach to model-based small area prediction for counts is proposed and used for estimating the average number of visits to physicians for Health Districts in Central Italy. The proposed small area predictor can be viewed as an outlier robust alternative to the more commonly used empirical plug-in predictor that is based on a Poisson generalized linear mixed model with Gaussian random effects. Results from the real data application and from a simulation experiment confirm that the proposed small area predictor has good robustness properties and in some cases can be more efficient than alternative small area approaches. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  1. Advanced photon counting applications, methods, instrumentation

    CERN Document Server

    Kapusta, Peter; Erdmann, Rainer

    2015-01-01

    This volume focuses on Time-Correlated Single Photon Counting (TCSPC), a powerful tool allowing luminescence lifetime measurements to be made with high temporal resolution, even on single molecules. Combining spectrum and lifetime provides a "fingerprint" for identifying such molecules in the presence of a background. Used together with confocal detection, this permits single-molecule spectroscopy and microscopy in addition to ensemble measurements, opening up an enormous range of hot life science applications such as fluorescence lifetime imaging (FLIM) and measurement of Förster Resonant Energy Transfer (FRET) for the investigation of protein folding and interaction. Several technology-related chapters present both the basics and current state-of-the-art, in particular of TCSPC electronics, photon detectors and lasers. The remaining chapters cover a broad range of applications and methodologies for experiments and data analysis, including the life sciences, defect centers in diamonds, super-resolution micr...

  2. A generalized model for coincidence counting

    International Nuclear Information System (INIS)

    Lu, Ming-Shih; Teichmann, T.

    1992-01-01

    The aim of this paper is to provide a description of the multiplicative processes associated with coincidence counting techniques, for example in the NDA of plutonium bearing materials. The model elucidates both the physical processes and the underlying mathematical formalism in a relatively simple but comprehensive way. In particular, it includes the effect of absorption by impurities or poisons, as well as that of neutron leakage on a parallel basis to the treatment of induced fission itself. The work thus parallels and generalizes the methods of Boehnel of Hage and Cifarelli, and more recently of Yanjushkin. This paper introduces the concept of a dual probability generating function to account for both the basic physical multiplication phenomena, as well as the detection phenomena. The underlying approach extends the idea of a simple probability generating function, due to De Moivre. The basic mathematical background may be found, for example, in Feller 1966

  3. Optics study of liquid scintillation counting systems

    International Nuclear Information System (INIS)

    Duran Ramiro, M. T.; Garcia-Torano, E.

    2005-01-01

    Optics is a key issue in the development of any liquid scintillation counting (LSC) system. Light emission in the scintillating solution, transmission through the vial and reflector design are some aspects that need to be considered in detail. This paper describes measurements and calculations carried out to optimise these factors for the design of a new family of LSC counters. Measurements of the light distribution emitted by a scintillation vial were done by autoradiographs of cylindrical vials made of various materials and results were compared to those obtained by direct measurements of the light distribution made by scanning the vial with a photomultiplier tube. Calculations were also carried out to study the light transmission in the vial and the optimal design of the reflector for a system with one photomultiplier tube. (Author)

  4. Upgradation of automatic liquid scintillation counting system

    International Nuclear Information System (INIS)

    Bhattacharya, Sadhana; Behere, Anita; Sonalkar, S.Y.; Vaidya, P.P.

    2001-01-01

    This paper describes the upgradation of Microprocessor based Automatic Liquid Scintillation Counting systems (MLSC). This system was developed in 1980's and subsequently many systems were manufactured and supplied to Environment Survey labs at various Nuclear Power Plants. Recently this system has been upgraded to a more sophisticated one by using PC add-on hardware and developing Windows based software. The software implements more intuitive graphical user interface and also enhances the features making it comparable with commercially available systems. It implements data processing using full spectrum analysis as against channel ratio method adopted earlier, improving the accuracy of the results. Also it facilitates qualitative as well as quantitative analysis of the β-spectrum. It is possible to analyze a sample containing an unknown β-source. (author)

  5. Total lymphocyte count and subpopulation lymphocyte counts in relation to dietary intake and nutritional status of peritoneal dialysis patients.

    Science.gov (United States)

    Grzegorzewska, Alicja E; Leander, Magdalena

    2005-01-01

    Dietary deficiency causes abnormalities in circulating lymphocyte counts. For the present paper, we evaluated correlations between total and subpopulation lymphocyte counts (TLC, SLCs) and parameters of nutrition in peritoneal dialysis (PD) patients. Studies were carried out in 55 patients treated with PD for 22.2 +/- 11.4 months. Parameters of nutritional status included total body mass, lean body mass (LBM), body mass index (BMI), and laboratory indices [total protein, albumin, iron, ferritin, and total iron binding capacity (TIBC)]. The SLCs were evaluated using flow cytometry. Positive correlations were seen between TLC and dietary intake of niacin; TLC and CD8 and CD16+56 counts and energy delivered from protein; CD4 count and beta-carotene and monounsaturated fatty acids 17:1 intake; and CD19 count and potassium, copper, vitamin A, and beta-carotene intake. Anorexia negatively influenced CD19 count. Serum albumin showed correlations with CD4 and CD19 counts, and LBM with CD19 count. A higher CD19 count was connected with a higher red blood cell count, hemoglobin, and hematocrit. Correlations were observed between TIBC and TLC and CD3 and CD8 counts, and between serum Fe and TLC and CD3 and CD4 counts. Patients with a higher CD19 count showed a better clinical-laboratory score, especially less weakness. Patients with a higher CD4 count had less expressed insomnia. Quantities of ingested vitamins and minerals influence lymphocyte counts in the peripheral blood of PD patients. Evaluation of TLC and SLCs is helpful in monitoring the effectiveness of nutrition in these patients.

  6. Counting OCR errors in typeset text

    Science.gov (United States)

    Sandberg, Jonathan S.

    1995-03-01

    Frequently object recognition accuracy is a key component in the performance analysis of pattern matching systems. In the past three years, the results of numerous excellent and rigorous studies of OCR system typeset-character accuracy (henceforth OCR accuracy) have been published, encouraging performance comparisons between a variety of OCR products and technologies. These published figures are important; OCR vendor advertisements in the popular trade magazines lead readers to believe that published OCR accuracy figures effect market share in the lucrative OCR market. Curiously, a detailed review of many of these OCR error occurrence counting results reveals that they are not reproducible as published and they are not strictly comparable due to larger variances in the counts than would be expected by the sampling variance. Naturally, since OCR accuracy is based on a ratio of the number of OCR errors over the size of the text searched for errors, imprecise OCR error accounting leads to similar imprecision in OCR accuracy. Some published papers use informal, non-automatic, or intuitively correct OCR error accounting. Still other published results present OCR error accounting methods based on string matching algorithms such as dynamic programming using Levenshtein (edit) distance but omit critical implementation details (such as the existence of suspect markers in the OCR generated output or the weights used in the dynamic programming minimization procedure). The problem with not specifically revealing the accounting method is that the number of errors found by different methods are significantly different. This paper identifies the basic accounting methods used to measure OCR errors in typeset text and offers an evaluation and comparison of the various accounting methods.

  7. Enhanced counting efficiency of Cerenkov radiation from bismuth-210

    International Nuclear Information System (INIS)

    Peck, G.A.; Smith, J.D.

    1998-01-01

    This paper describes the measurement of 210 Bi by Cerenkov counting in a commercial liquid scintillation counter. The counting efficiency in water is 0.17 counts per second per Becquerel (17%). When the enhancers Triton X-100 (15% v/v) and sodium salicylate (1% m/v) are added to the solution the counting efficiency for 210 Bi increases from 17% to 75%. The 210 Po daughter of 210 Bi causes interference of 0.85 counts per second per Becquerel in the presence of the enhancers but not in water. When 210 Bi and 210 Po are present in secular equilibrium the total counting efficiency is 160%. When 210 Bi and 210 Po are not in secular equilibrium the 210 Po can be removed immediately before counting by plating onto silver foil. The use of the enhancers gives a substantial increase in counting efficiency compared to counting in water. Compared with solutions used in liquid scintillation counting the enhancer solution is inexpensive and can be disposed of without environmental hazard. (author)

  8. Standardization of Ga-68 by coincidence measurements, liquid scintillation counting and 4πγ counting.

    Science.gov (United States)

    Roteta, Miguel; Peyres, Virginia; Rodríguez Barquero, Leonor; García-Toraño, Eduardo; Arenillas, Pablo; Balpardo, Christian; Rodrígues, Darío; Llovera, Roberto

    2012-09-01

    The radionuclide (68)Ga is one of the few positron emitters that can be prepared in-house without the use of a cyclotron. It disintegrates to the ground state of (68)Zn partially by positron emission (89.1%) with a maximum energy of 1899.1 keV, and partially by electron capture (10.9%). This nuclide has been standardized in the frame of a cooperation project between the Radionuclide Metrology laboratories from CIEMAT (Spain) and CNEA (Argentina). Measurements involved several techniques: 4πβ-γ coincidences, integral gamma counting and Liquid Scintillation Counting using the triple to double coincidence ratio and the CIEMAT/NIST methods. Given the short half-life of the radionuclide assayed, a direct comparison between results from both laboratories was excluded and a comparison of experimental efficiencies of similar NaI detectors was used instead. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Cascaded systems analysis of photon counting detectors.

    Science.gov (United States)

    Xu, J; Zbijewski, W; Gang, G; Stayman, J W; Taguchi, K; Lundqvist, M; Fredenberg, E; Carrino, J A; Siewerdsen, J H

    2014-10-01

    Photon counting detectors (PCDs) are an emerging technology with applications in spectral and low-dose radiographic and tomographic imaging. This paper develops an analytical model of PCD imaging performance, including the system gain, modulation transfer function (MTF), noise-power spectrum (NPS), and detective quantum efficiency (DQE). A cascaded systems analysis model describing the propagation of quanta through the imaging chain was developed. The model was validated in comparison to the physical performance of a silicon-strip PCD implemented on an experimental imaging bench. The signal response, MTF, and NPS were measured and compared to theory as a function of exposure conditions (70 kVp, 1-7 mA), detector threshold, and readout mode (i.e., the option for coincidence detection). The model sheds new light on the dependence of spatial resolution, charge sharing, and additive noise effects on threshold selection and was used to investigate the factors governing PCD performance, including the fundamental advantages and limitations of PCDs in comparison to energy-integrating detectors (EIDs) in the linear regime for which pulse pileup can be ignored. The detector exhibited highly linear mean signal response across the system operating range and agreed well with theoretical prediction, as did the system MTF and NPS. The DQE analyzed as a function of kilovolt (peak), exposure, detector threshold, and readout mode revealed important considerations for system optimization. The model also demonstrated the important implications of false counts from both additive electronic noise and charge sharing and highlighted the system design and operational parameters that most affect detector performance in the presence of such factors: for example, increasing the detector threshold from 0 to 100 (arbitrary units of pulse height threshold roughly equivalent to 0.5 and 6 keV energy threshold, respectively), increased the f50 (spatial-frequency at which the MTF falls to a value of

  10. Cascaded systems analysis of photon counting detectors

    International Nuclear Information System (INIS)

    Xu, J.; Zbijewski, W.; Gang, G.; Stayman, J. W.; Taguchi, K.; Carrino, J. A.; Lundqvist, M.; Fredenberg, E.; Siewerdsen, J. H.

    2014-01-01

    Purpose: Photon counting detectors (PCDs) are an emerging technology with applications in spectral and low-dose radiographic and tomographic imaging. This paper develops an analytical model of PCD imaging performance, including the system gain, modulation transfer function (MTF), noise-power spectrum (NPS), and detective quantum efficiency (DQE). Methods: A cascaded systems analysis model describing the propagation of quanta through the imaging chain was developed. The model was validated in comparison to the physical performance of a silicon-strip PCD implemented on an experimental imaging bench. The signal response, MTF, and NPS were measured and compared to theory as a function of exposure conditions (70 kVp, 1–7 mA), detector threshold, and readout mode (i.e., the option for coincidence detection). The model sheds new light on the dependence of spatial resolution, charge sharing, and additive noise effects on threshold selection and was used to investigate the factors governing PCD performance, including the fundamental advantages and limitations of PCDs in comparison to energy-integrating detectors (EIDs) in the linear regime for which pulse pileup can be ignored. Results: The detector exhibited highly linear mean signal response across the system operating range and agreed well with theoretical prediction, as did the system MTF and NPS. The DQE analyzed as a function of kilovolt (peak), exposure, detector threshold, and readout mode revealed important considerations for system optimization. The model also demonstrated the important implications of false counts from both additive electronic noise and charge sharing and highlighted the system design and operational parameters that most affect detector performance in the presence of such factors: for example, increasing the detector threshold from 0 to 100 (arbitrary units of pulse height threshold roughly equivalent to 0.5 and 6 keV energy threshold, respectively), increased the f 50 (spatial-frequency at

  11. Cascaded systems analysis of photon counting detectors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.; Zbijewski, W.; Gang, G.; Stayman, J. W. [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Taguchi, K.; Carrino, J. A. [Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Lundqvist, M.; Fredenberg, E. [Philips Healthcare, Solna 171 41 (Sweden); Siewerdsen, J. H., E-mail: jeff.siewerdsen@jhu.edu [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21205 (United States)

    2014-10-15

    Purpose: Photon counting detectors (PCDs) are an emerging technology with applications in spectral and low-dose radiographic and tomographic imaging. This paper develops an analytical model of PCD imaging performance, including the system gain, modulation transfer function (MTF), noise-power spectrum (NPS), and detective quantum efficiency (DQE). Methods: A cascaded systems analysis model describing the propagation of quanta through the imaging chain was developed. The model was validated in comparison to the physical performance of a silicon-strip PCD implemented on an experimental imaging bench. The signal response, MTF, and NPS were measured and compared to theory as a function of exposure conditions (70 kVp, 1–7 mA), detector threshold, and readout mode (i.e., the option for coincidence detection). The model sheds new light on the dependence of spatial resolution, charge sharing, and additive noise effects on threshold selection and was used to investigate the factors governing PCD performance, including the fundamental advantages and limitations of PCDs in comparison to energy-integrating detectors (EIDs) in the linear regime for which pulse pileup can be ignored. Results: The detector exhibited highly linear mean signal response across the system operating range and agreed well with theoretical prediction, as did the system MTF and NPS. The DQE analyzed as a function of kilovolt (peak), exposure, detector threshold, and readout mode revealed important considerations for system optimization. The model also demonstrated the important implications of false counts from both additive electronic noise and charge sharing and highlighted the system design and operational parameters that most affect detector performance in the presence of such factors: for example, increasing the detector threshold from 0 to 100 (arbitrary units of pulse height threshold roughly equivalent to 0.5 and 6 keV energy threshold, respectively), increased the f{sub 50} (spatial

  12. The lost castle of Count Rodrigo Gonzalez

    Directory of Open Access Journals (Sweden)

    Ehrlich, Michael

    2015-12-01

    Full Text Available This article suggests that a castle called Toron built in 1137 by Count Rodrigo of Lara, and granted to the Templar Order was in Summil, where remains of a Crusader castles are still visible (ca. 25 km from Ascalon, in south west Israel. This opinion opposes a consensual view that the castle built by Count Rodrigo was in Latrun, midway between Tel-Aviv and Jerusalem. This identifi cation is based on names’ similarity and on the universal opinion that Latrun was a Templar castle. In this article it is demonstrated that the geographic setting of Summil fi ts the Count’s castle, whereas Latrun does not; that Toron was a common name in the Crusader Kingdom; and, moreover, it is not certain that Latrun was a Templar castle. The article also suggest that there was a village near the castle, called Casale Sancti Salvatoris, and also discusses Frankish fortifi cation and settlement policy during the twelfth century.Este artículo sugiere que un castillo llamado Toron, construido el año 1137 por el conde Rodrigo González de Lara, y que fue luego otorgado a la orden del Temple, estaba en Summil, donde todavía permanecen las ruinas de un castillo de los cruzados (a unos 25 km de Ascalon, en el sudoeste de Israel. Esta opinión se contrapone a la tesis general que sostiene que el castillo construido por el conde estuvo situado en Latrun, a medio camino entre Tel-Aviv y Jerusalén. Una identificación basada en la similitud de nombres y en la común opinión que Latrun era un castillo templario. En este estudio se demuestra que la ubicación geográfica de Summil encaja con la del castillo del conde, mientras que Latrun no lo hace; que Toron fue un nombre habitual en el reino cruzado y que, por otra parte, no es cierto que Latrun fuera un castillo templario. Se sugiere también que cerca del castillo de Summil existía un pueblo llamado casale Sancti Salvatoris, analizándose asimismo la política de fortificación y colonización llevada a cabo por

  13. Fitting a distribution to miccrobial counts: making sense of zeros

    DEFF Research Database (Denmark)

    Ribeiro Duarte, Ana Sofia; Stockmarr, Anders; Nauta, Maarten

    and standard deviation) and the prevalence of contaminated food units (one minus the proportion of “true zeros”) from a set of microbial counts. By running the model with in silico generated concentration and count data, we could evaluate the performance of this method in terms of estimation of the three......Non-detects or left-censored results are inherent to the traditional methods of microbial enumeration in foods. Typically, a low concentration of microorganisms in a food unit goes undetected in plate counts or most probable number (MPN) counts, and produces “artificial zeros”. However......, these “artificial zeros” are only a share of the total number of zero counts resulting from a sample, as their number adds up to the number of “true zeros” resulting from uncontaminated units. In the process of fitting a probability distribution to microbial counts, “artificial” and “true” zeros are usually...

  14. Automated uranium analysis by delayed-neutron counting

    International Nuclear Information System (INIS)

    Kunzendorf, H.; Loevborg, L.; Christiansen, E.M.

    1980-10-01

    Automated uranium analysis by fission-induced delayed-neutron counting is described. A short description is given of the instrumentation including transfer system, process control, irradiation and counting sites, and computer operations. Characteristic parameters of the facility (sample preparations, background, and standards) are discussed. A sensitivity of 817 +- 22 counts per 10 -6 g U is found using irradiation, delay, and counting times of 20 s, 5 s, and 10 s, respectively. Presicion is generally less than 1% for normal geological samples. Critical level and detection limits for 7.5 g samples are 8 and 16 ppb, respectively. The importance of some physical and elemental interferences are outlined. Dead-time corrections of measured count rates are necessary and a polynomical expression is used for count rates up to 10 5 . The presence of rare earth elements is regarded as the most important elemental interference. A typical application is given and other areas of application are described. (auther)

  15. Atmospheric mold spore counts in relation to meteorological parameters

    Science.gov (United States)

    Katial, R. K.; Zhang, Yiming; Jones, Richard H.; Dyer, Philip D.

    Fungal spore counts of Cladosporium, Alternaria, and Epicoccum were studied during 8 years in Denver, Colorado. Fungal spore counts were obtained daily during the pollinating season by a Rotorod sampler. Weather data were obtained from the National Climatic Data Center. Daily averages of temperature, relative humidity, daily precipitation, barometric pressure, and wind speed were studied. A time series analysis was performed on the data to mathematically model the spore counts in relation to weather parameters. Using SAS PROC ARIMA software, a regression analysis was performed, regressing the spore counts on the weather variables assuming an autoregressive moving average (ARMA) error structure. Cladosporium was found to be positively correlated (Pmodel was derived for Cladosporium spore counts using the annual seasonal cycle and significant weather variables. The model for Alternaria and Epicoccum incorporated the annual seasonal cycle. Fungal spore counts can be modeled by time series analysis and related to meteorological parameters controlling for seasonallity; this modeling can provide estimates of exposure to fungal aeroallergens.

  16. Tutorial on Using Regression Models with Count Outcomes Using R

    Directory of Open Access Journals (Sweden)

    A. Alexander Beaujean

    2016-02-01

    Full Text Available Education researchers often study count variables, such as times a student reached a goal, discipline referrals, and absences. Most researchers that study these variables use typical regression methods (i.e., ordinary least-squares either with or without transforming the count variables. In either case, using typical regression for count data can produce parameter estimates that are biased, thus diminishing any inferences made from such data. As count-variable regression models are seldom taught in training programs, we present a tutorial to help educational researchers use such methods in their own research. We demonstrate analyzing and interpreting count data using Poisson, negative binomial, zero-inflated Poisson, and zero-inflated negative binomial regression models. The count regression methods are introduced through an example using the number of times students skipped class. The data for this example are freely available and the R syntax used run the example analyses are included in the Appendix.

  17. Set of counts by scintillations for atmospheric samplings

    International Nuclear Information System (INIS)

    Appriou, D.; Doury, A.

    1962-01-01

    The author reports the development of a scintillation-based counting assembly with the following characteristics: a photo-multiplier with a wide photo-cathode, a thin plastic scintillator for the counting of beta + alpha (and possibility of mounting an alpha scintillator), a relatively small own motion with respect to activities to be counted, a weakly varying efficiency. The authors discuss the counting objective, present equipment tests (counter, proportional amplifier and pre-amplifier, input drawer). They describe the apparatus operation, discuss the selection of scintillators, report the study of the own movement (electron-based background noise, total background noise, background noise reduction), discuss counts (influence of the external source, sensitivity to alpha radiations, counting homogeneity, minimum detectable activity) and efficiencies

  18. Total lymphocyte count as a substitute to cd4 count in management of hiv infected individuals in resource limited society

    International Nuclear Information System (INIS)

    Daud, M.Y.; Qazi, R.A.

    2015-01-01

    Pakistan is a resource limited society and gold standard parameters to monitor HIV disease activity are very costly. The objective of the study was to evaluate total lymphocyte count (TLC) as a surrogate to CD4 count to monitor disease activity in HIV/AIDS in resource limited society. Methods: This cross sectional study was carried out at HIV/AIDS treatment centre, Pakistan Institute of Medical Sciences (PIMS), Islamabad. A total of seven hundred and seventy four (774) HIV positive patients were enrolled in this study, and their CD4 count and total lymphocyte count were checked to find any correlation between the two by using Spearman ranked correlation coefficient. Results: The mean CD4 count was (434.30 ± 269.23), with minimum CD4 count of (9.00), and maximum of (1974.00). The mean total lymphocyte count (TLC) was (6764.0052 ± 2364.02) with minimum TLC (1200.00) and maximum TLC was (20200.00). Using the Pearson's correlation (r) there was a significant and positive correlation between TLC and CD4 count. (r2=0.127 and p=0.000) at 0.01 level. Conclusion: Our study showed a significant positive correlation between CD4 count and total lymphocyte count (TLC), so TLC can be used as a marker of disease activity in HIV infected patients. (author)

  19. Nuclear chemistry counting facilities: requirements definition

    International Nuclear Information System (INIS)

    O'Brien, D.W.; Baker, J.

    1979-01-01

    In an effort to upgrade outdated instrumentation and to take advantage of current and imminent technologies the Nuclear Chemistry Division at Lawrence Livermore Laboratory is about to undertake a major upgrade of their low level radiation counting and analysis facilities. It is expected that such a project will make a more coordinated data acquisition and data processing system, reduce manual data handling operations and speed up data processing throughput. Before taking on a systems design it is appropriate to establish a definition of the requirements of the facilities. This report examines why such a project is necessary in the context of the current and projected operations, needs, problems, risks and costs. The authors also address a functional specification as a prelude to a system design and the design constraints implicit in the systems implementation. Technical, operational and economic assessments establish necessary boundary conditions for this discussion. This report also establishes the environment in which the requirements definition may be considered valid. The validity of these analyses is contingent on known and projected technical, scientific and political conditions

  20. Photon counting arrays for AO wavefront sensors

    CERN Document Server

    Vallerga, J; McPhate, J; Mikulec, Bettina; Clark, Allan G; Siegmund, O; CERN. Geneva

    2005-01-01

    Future wavefront sensors for AO on large telescopes will require a large number of pixels and must operate at high frame rates. Unfortunately for CCDs, there is a readout noise penalty for operating faster, and this noise can add up rather quickly when considering the number of pixels required for the extended shape of a sodium laser guide star observed with a large telescope. Imaging photon counting detectors have zero readout noise and many pixels, but have suffered in the past with low QE at the longer wavelengths (>500 nm). Recent developments in GaAs photocathode technology, CMOS ASIC readouts and FPGA processing electronics have resulted in noiseless WFS detector designs that are competitive with silicon array detectors, though at ~40% the QE of CCDs. We review noiseless array detectors and compare their centroiding performance with CCDs using the best available characteristics of each. We show that for sub-aperture binning of 6x6 and greater that noiseless detectors have a smaller centroid error at flu...

  1. Quantum Biometrics with Retinal Photon Counting

    Science.gov (United States)

    Loulakis, M.; Blatsios, G.; Vrettou, C. S.; Kominis, I. K.

    2017-10-01

    It is known that the eye's scotopic photodetectors, rhodopsin molecules, and their associated phototransduction mechanism leading to light perception, are efficient single-photon counters. We here use the photon-counting principles of human rod vision to propose a secure quantum biometric identification based on the quantum-statistical properties of retinal photon detection. The photon path along the human eye until its detection by rod cells is modeled as a filter having a specific transmission coefficient. Precisely determining its value from the photodetection statistics registered by the conscious observer is a quantum parameter estimation problem that leads to a quantum secure identification method. The probabilities for false-positive and false-negative identification of this biometric technique can readily approach 10-10 and 10-4, respectively. The security of the biometric method can be further quantified by the physics of quantum measurements. An impostor must be able to perform quantum thermometry and quantum magnetometry with energy resolution better than 10-9ℏ , in order to foil the device by noninvasively monitoring the biometric activity of a user.

  2. High counting rate resistive-plate chamber

    International Nuclear Information System (INIS)

    Peskov, V.; Anderson, D.F.; Kwan, S.

    1993-05-01

    Parallel-plate avalanche chambers (PPAC) are widely used in physics experiments because they are fast ( 5 counts/mm 2 . A resistive-plate chamber (RPC) is similar to the PPAC in construction except that one or both of the electrodes are made from high resistivity (≥10 10 Ω·cm) materials. In practice RPCs are usually used in the spark mode. Resistive electrodes are charged by sparks, locally reducing the actual electric field in the gap. The size of the charged surface is about 10 mm 2 , leaving the rest of the detector unaffected. Therefore, the rate capability of such detectors in the spark mode is considerably higher than conventional spark counters. Among the different glasses tested the best results were obtained with electron type conductive glasses, which obey Ohm's law. Most of the work with such glasses was done with high pressure parallel-plate chambers (10 atm) for time-of-flight measurements. Resistive glasses have been expensive and produced only in small quantities. Now resistive glasses are commercially available, although they are still expensive in small scale production. From the positive experience of different groups working with the resistive glasses, it was decided to review the old idea to use this glass for the RPC. This work has investigated the possibility of using the RPC at 1 atm and in the avalanche mode. This has several advantages: simplicity of construction, high rate capability, low voltage operation, and the ability to work with non-flammable gases

  3. Color quench correction for low level Cherenkov counting.

    Science.gov (United States)

    Tsroya, S; Pelled, O; German, U; Marco, R; Katorza, E; Alfassi, Z B

    2009-05-01

    The Cherenkov counting efficiency varies strongly with color quenching, thus correction curves must be used to obtain correct results. The external (152)Eu source of a Quantulus 1220 liquid scintillation counting (LSC) system was used to obtain a quench indicative parameter based on spectra area ratio. A color quench correction curve for aqueous samples containing (90)Sr/(90)Y was prepared. The main advantage of this method over the common spectra indicators is its usefulness also for low level Cherenkov counting.

  4. An Automatic Car Counting System Using OverFeat Framework

    OpenAIRE

    Biswas, Debojit; Su, Hongbo; Wang, Chengyi; Blankenship, Jason; Stevanovic, Aleksandar

    2017-01-01

    Automatic car counting is an important component in the automated traffic system. Car counting is very important to understand the traffic load and optimize the traffic signals. In this paper, we implemented the Gaussian Background Subtraction Method and OverFeat Framework to count cars. OverFeat Framework is a combination of Convolution Neural Network (CNN) and one machine learning classifier (like Support Vector Machines (SVM) or Logistic Regression). With this study, we showed another poss...

  5. Absolute nuclear material assay using count distribution (LAMBDA) space

    Science.gov (United States)

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2012-06-05

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  6. Limits of reliability for the measurement of integral count

    International Nuclear Information System (INIS)

    Erbeszkorn, L.

    1979-01-01

    A method is presented for exact and approximate calculation of reliability limits of measured nuclear integral count. The formulae are applicable in measuring conditions which assure the Poisson distribution of the counts. The coefficients of the approximate formulae for 90, 95, 98 and 99 per cent reliability levels are given. The exact reliability limits for 90 per cent reliability level are calculated up to 80 integral counts. (R.J.)

  7. Men of physics Count Rumford on the nature of heat

    CERN Document Server

    Brown, Sanborn C

    2013-01-01

    Men of Physics: Benjamin Thompson—Count Rumford: Count Rumford on the Nature of Heat presents the life and works of Count Rumford, an American-born British physicist and inventor. This book is divided in two parts. The first part gives a biographical sketch of Count Rumford, Benjamin Thompson, who was born on March 23, 1753 and died in 1814. This part also discusses the contemporary caloric theory and the reason why Rumford disbelieved the theory. The second part presents his technical works, discoveries, and contributions in the field of physics. Some of which are his demonstration of the e

  8. Problems and precision of the alpha scintillation radon counting system

    International Nuclear Information System (INIS)

    Lucas, H.F.; Markuu, F.

    1985-01-01

    Variations in efficiency as large as 3% have been found for radon scintillation counting systems in which the photomultiplier tubes are sensitive to the thermoluminescent photons emitted by the scintillator after exposure to light or for which the resolution has deteriorated. The additional standard deviation caused by counting a radon chamber on multiple counting systems has been evaluated and the effect, if present, did not exceed about 0.1%. The chambers have been calibrated for the measurement of radon in air, and the standard deviation was equal to statistical counting error combined with a systematic error of 1.1%. 3 references, 2 figures, 2 tables

  9. A multiwire proportional counter for very high counting rates

    International Nuclear Information System (INIS)

    Barbosa, A.F.; Guedes, G.P.; Tamura, E.; Pepe, I.M.; Oliveira, N.B.

    1997-12-01

    Preliminary measurements in a proportional counter with two independently counting wires showed that counting rates up to 10 6 counts/s per wire can be reached without critical loss in the true versus measured linearity relation. Results obtained with a detector containing 30 active wires (2 mm pitch) are presented. To each wire is associated a fast pre-amplifier and a discriminator channel. Global counting rates in excess to 10 7 events/s are reported. Data acquisition systems are described for 1D (real time) and 2D (off-line) position sensitive detection systems. (author)

  10. Method of inspecting Raschig rings by neutron absorption counting

    International Nuclear Information System (INIS)

    Morris, R.N.; Murri, R.L.; Hume, M.W.

    1979-01-01

    A neutron counting method for inspecting borosilicate glass Raschig rings and an apparatus designed specifically for this method are discussed. The neutron count ratios for rings of a given thickness show a linear correlation to the boron oxide content of the rings. The count ratio also has a linear relationship to the thickness of rings of a given boron oxide content. Consequently, the experimentally-determined count ratio and physically-measured thickness of Raschig rings can be used to statistically predict their boron oxide content and determine whether or not they meet quality control acceptance criteria

  11. Development of a mobile application for manual traffic counts

    Directory of Open Access Journals (Sweden)

    Ghanim Mohammad

    2017-01-01

    Full Text Available The use of technology in performing traffic counts has become widely used by many transportation agencies and private sectors. Different technologies have been employed to perform such counts, such as inductive loops, image processing, Bluetooth technologies, and laser and infrared technologies. However, the use of these advanced technologies come with extra cost to develop, install, and maintain. While the use of advanced technologies provide reliable traffic counts and vehicle classifications data, the use of manual traffic is an inevitable task. Manual traffic counts can serve different purposes, such as performing quality control or conducting short-term traffic survey. Manual traffic counts are usually conducted with the use of the traditional paper-and-pencil approach or the use of hand-held devices that are specifically developed to assess performing manual traffic counts. In this paper, the development of a mobile app that can be used to assist those who need to perform manual traffic counts. The app can be used by many public agencies, private sectors, and college students to collect their traffic data. It also provides users with the capabilities of sharing their traffic counts instantly, where traffic counts can be extracted and processed quickly by other parties.

  12. A multiwire proportional counter for very high counting rates

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, A F; Guedes, G P [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Tamura, E [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil); Pepe, I M; Oliveira, N B [Bahia Univ., Salvador, BA (Brazil). Inst. de Fisica

    1997-12-01

    Preliminary measurements in a proportional counter with two independently counting wires showed that counting rates up to 10{sup 6} counts/s per wire can be reached without critical loss in the true versus measured linearity relation. Results obtained with a detector containing 30 active wires (2 mm pitch) are presented. To each wire is associated a fast pre-amplifier and a discriminator channel. Global counting rates in excess to 10{sup 7} events/s are reported. Data acquisition systems are described for 1D (real time) and 2D (off-line) position sensitive detection systems. (author) 13 refs., 6 figs.

  13. Big drop. [Decline in sperm counts from environmental pollution

    Energy Technology Data Exchange (ETDEWEB)

    Castleman, M.

    Statisticians at the University of Copenhagen have published a review of sperm-count studies carried out from 1938-1990. After controlling for such things as counting techniques and sexual activity, they found that average sperm counts have decreased 42% over the last 50 years. After eliminating possible causes such as heat and differences in counting techniques, the only plausible cause left was environmental pollution. This finding correlates with a study performed in 1979 which found abnormally high concentrations of such toxic pollutants as DDT and PCBs in semen. The Copenhagen study suggests that even at low levels of exposure, environmental pollution is having biological consequences.

  14. Counting skills intervention for low-performing first graders

    Directory of Open Access Journals (Sweden)

    Riikka Mononen

    2016-09-01

    Conclusion: A relatively short counting skills intervention that applied explicit teaching showed promising effects in improving low-performing children’s mathematical performance as a supplemental instruction.

  15. Improving global health: counting reasons why.

    Science.gov (United States)

    Selgelid, Michael J

    2008-08-01

    This paper examines cumulative ethical and self-interested reasons why wealthy developed nations should be motivated to do more to improve health care in developing countries. Egalitarian and human rights reasons why wealthy nations should do more to improve global health are that doing so would (1) promote equality of opportunity (2) improve the situation of the worst-off, (3) promote respect of the human right to have one's most basic needs met, and (4) reduce undeserved inequalities in well-being. Utilitarian reasons for improving global health are that this would (5) promote the greater good of humankind, and (6) achieve enormous benefits while requiring only small sacrifices. Libertarian reasons are that this would (7) amend historical injustices and (8) meet the obligation to amend injustices that developed world countries have contributed to. Self-interested reasons why wealthy nations should do more to improve global health are that doing so would (9) reduce the threat of infectious diseases to developed countries, (10) promote developed countries' economic interests, and (11) promote global security. All of these reasons count, and together they add up to make an overwhelmingly powerful case for change. Those opposed to wealthy government funding of developing world health improvement would most likely appeal, implicitly or explicitly to the idea that coercive taxation for redistributive purposes would violate the right of an individual to keep his hard-earned income. The idea that this reason not to improve global health should outweigh the combination of rights and values embodied in the eleven reasons enumerated above, however is implausibly extreme, morally repugnant and perhaps imprudent.

  16. Combining cluster number counts and galaxy clustering

    Energy Technology Data Exchange (ETDEWEB)

    Lacasa, Fabien; Rosenfeld, Rogerio, E-mail: fabien@ift.unesp.br, E-mail: rosenfel@ift.unesp.br [ICTP South American Institute for Fundamental Research, Instituto de Física Teórica, Universidade Estadual Paulista, São Paulo (Brazil)

    2016-08-01

    The abundance of clusters and the clustering of galaxies are two of the important cosmological probes for current and future large scale surveys of galaxies, such as the Dark Energy Survey. In order to combine them one has to account for the fact that they are not independent quantities, since they probe the same density field. It is important to develop a good understanding of their correlation in order to extract parameter constraints. We present a detailed modelling of the joint covariance matrix between cluster number counts and the galaxy angular power spectrum. We employ the framework of the halo model complemented by a Halo Occupation Distribution model (HOD). We demonstrate the importance of accounting for non-Gaussianity to produce accurate covariance predictions. Indeed, we show that the non-Gaussian covariance becomes dominant at small scales, low redshifts or high cluster masses. We discuss in particular the case of the super-sample covariance (SSC), including the effects of galaxy shot-noise, halo second order bias and non-local bias. We demonstrate that the SSC obeys mathematical inequalities and positivity. Using the joint covariance matrix and a Fisher matrix methodology, we examine the prospects of combining these two probes to constrain cosmological and HOD parameters. We find that the combination indeed results in noticeably better constraints, with improvements of order 20% on cosmological parameters compared to the best single probe, and even greater improvement on HOD parameters, with reduction of error bars by a factor 1.4-4.8. This happens in particular because the cross-covariance introduces a synergy between the probes on small scales. We conclude that accounting for non-Gaussian effects is required for the joint analysis of these observables in galaxy surveys.

  17. Factor V Leiden is associated with increased sperm count

    NARCIS (Netherlands)

    van Mens, T. E.; Joensen, U. N.; Bochdanovits, Z.; Takizawa, A.; Peter, J.; Jørgensen, N.; Szecsi, P. B.; Meijers, J. C. M.; Weiler, H.; Rajpert-de Meyts, E.; Repping, S.; Middeldorp, S.

    2017-01-01

    STUDY QUESTION: Is the thrombophilia mutation factor V Leiden (FVL) associated with an increased total sperm count? SUMMARY ANSWER: Carriers of FVL have a higher total sperm count than non-FVL-carriers, which could not be explained by genetic linkage or by observations in a FVL-mouse model. WHAT IS

  18. Analysis of spatial count data using Kalman smoothing

    DEFF Research Database (Denmark)

    Dethlefsen, Claus

    2007-01-01

    We consider spatial count data from an agricultural field experiment. Counts of weed plants in a field have been recorded in a project on precision farming. Interest is in mapping the weed intensity so that the dose of herbicide applied at any location can be adjusted to the amount of weed present...

  19. Liquid scintillation counting system with automatic gain correction

    International Nuclear Information System (INIS)

    Frank, R.B.

    1976-01-01

    An automatic liquid scintillation counting apparatus is described including a scintillating medium in the elevator ram of the sample changing apparatus. An appropriate source of radiation, which may be the external source for standardizing samples, produces reference scintillations in the scintillating medium which may be used for correction of the gain of the counting system

  20. Another Crisis Can We Count on the Reserves?

    Science.gov (United States)

    1994-05-16

    the " marshmallow " of volunteerism is something that is too soft of a concept to be counted upon. It only makes sense to develop a more well-defined...unrealistic. Involuntary activation has proven to be a hollow concept in practice, and planners are reluctant to count on the " marshmallow " of

  1. Counting efficiency formulae for two, three or four photomultiplier systems

    International Nuclear Information System (INIS)

    Grau Malonda, A.

    1993-01-01

    Counting efficiency formulae as a function of the non-detection probability and the electron distributions for systems with two, three or dour photomultipliers are obtained in this paper. It is assumed that the photocathode electron emission follows the Poisson distribution. The obtained formulae are basic to compute the counting efficiency in liquid scintillation spectrometers

  2. Evaluation of misplaced event count rate using a scintillation camera

    International Nuclear Information System (INIS)

    Yanagimoto, Shin-ichi; Tomomitsu, Tatsushi; Muranaka, Akira

    1985-01-01

    Misplaced event count rates were evaluated using an acryl scatter body of various thickness and a gamma camera. The count rate in the region of interest (ROI) within the camera view field, which was thought to represent part of the misplaced event count rate, increased as the thickness of the scatter body was increased to 5 cm, followed by a steep decline in the count rate. On the other hand, the ratio of the count rate in the ROI to the total count rate continuously increased as the thickness of the scatter body was increased. As the thickness of the scatter body was increased, the count rates increased, and the increments of increase were greater in the lower energy region of the photopeak than in the higher energy region. In ranges energy other than the photopeak, the influence of the scatter body on the count rate in the ROI was the greatest at 76 keV, which was the lowest energy we examined. (author)

  3. Changes in total and differential white cell counts, total lymphocyte ...

    African Journals Online (AJOL)

    Background: Published reports on the possible changes in the various immune cell populations, especially the total lymphocyte and CD4 cell counts, during the menstrual cycle in Nigerian female subjects are relatively scarce. Aim: To determine possible changes in the total and differential white blood cell [WBC] counts, ...

  4. Soil Characteristics, Microbial Compostion of Plot, Leaf Count and ...

    African Journals Online (AJOL)

    Soil Characteristics, Microbial Compostion of Plot, Leaf Count and Sprout Studies of Cocoyam ( Colocasia [Schott] and Xanthosoma [Schott], Araceae) Collected in Edo State, ... Science, Technology and Arts Research Journal ... Government Areas (LGA) in Edo state and describe them based on leaf count and sprout

  5. Fast pulse discriminator for photon counting at high photon densities

    International Nuclear Information System (INIS)

    Benoit, R.; Pedrini, A.

    1977-03-01

    A fast tunnel diode discriminator for photon counting up to 200MHz count frequency is described. The tunnel diode is operated on its apparent I.V. characteristics displayed when the diode is driven into its oscillating region. The pulse shaper-discriminator is completely D.C. coupled in order to avoid base-line shift at high pulse rates

  6. Baseline CD4 lymphocyte count among HIV patients in Kano ...

    African Journals Online (AJOL)

    kemrilib

    macrophages), the devastating effect of HIV on the immune system is not surprising. Given that HIV induced immunodeficiency is largely due to infection and gradual depletion of. CD4+ T-helper cells, CD4 count has become a useful indicator of immune function in infected patients. Hence CD4 count along with viral load ...

  7. Secure count query on encrypted genomic data.

    Science.gov (United States)

    Hasan, Mohammad Zahidul; Mahdi, Md Safiur Rahman; Sadat, Md Nazmus; Mohammed, Noman

    2018-05-01

    Human genomic information can yield more effective healthcare by guiding medical decisions. Therefore, genomics research is gaining popularity as it can identify potential correlations between a disease and a certain gene, which improves the safety and efficacy of drug treatment and can also develop more effective prevention strategies [1]. To reduce the sampling error and to increase the statistical accuracy of this type of research projects, data from different sources need to be brought together since a single organization does not necessarily possess required amount of data. In this case, data sharing among multiple organizations must satisfy strict policies (for instance, HIPAA and PIPEDA) that have been enforced to regulate privacy-sensitive data sharing. Storage and computation on the shared data can be outsourced to a third party cloud service provider, equipped with enormous storage and computation resources. However, outsourcing data to a third party is associated with a potential risk of privacy violation of the participants, whose genomic sequence or clinical profile is used in these studies. In this article, we propose a method for secure sharing and computation on genomic data in a semi-honest cloud server. In particular, there are two main contributions. Firstly, the proposed method can handle biomedical data containing both genotype and phenotype. Secondly, our proposed index tree scheme reduces the computational overhead significantly for executing secure count query operation. In our proposed method, the confidentiality of shared data is ensured through encryption, while making the entire computation process efficient and scalable for cutting-edge biomedical applications. We evaluated our proposed method in terms of efficiency on a database of Single-Nucleotide Polymorphism (SNP) sequences, and experimental results demonstrate that the execution time for a query of 50 SNPs in a database of 50,000 records is approximately 5 s, where each record

  8. Computed neutron coincidence counting applied to passive waste assay

    Energy Technology Data Exchange (ETDEWEB)

    Bruggeman, M.; Baeten, P.; De Boeck, W.; Carchon, R. [Nuclear Research Centre, Mol (Belgium)

    1997-11-01

    Neutron coincidence counting applied for the passive assay of fissile material is generally realised with dedicated electronic circuits. This paper presents a software based neutron coincidence counting method with data acquisition via a commercial PC-based Time Interval Analyser (TIA). The TIA is used to measure and record all time intervals between successive pulses in the pulse train up to count-rates of 2 Mpulses/s. Software modules are then used to compute the coincidence count-rates and multiplicity related data. This computed neutron coincidence counting (CNCC) offers full access to all the time information contained in the pulse train. This paper will mainly concentrate on the application and advantages of CNCC for the non-destructive assay of waste. An advanced multiplicity selective Rossi-alpha method is presented and its implementation via CNCC demonstrated. 13 refs., 4 figs., 2 tabs.

  9. Investigation of reduction in background counts of clover detector

    International Nuclear Information System (INIS)

    Kshetri, Ritesh

    2015-01-01

    The peak-to-total ratio can be improved by increasing the full energy peak (FEP) counts and/or by decreasing the background counts. It is notable that FEP counts will be effected by mode of operation, while background counts will be effected by both modes of operation and suppression cases. It would be interesting to know if the reduction in background is caused more by active suppression or by add back process. We introduce a simple formalism to investigate the reduction of background counts for different cases-single crystal or add back mode with active or passive suppression. A more sophisticated formalism for modeling a general composite detector had been presented in a series of six recent papers by the author

  10. Platelet count is associated with cardiovascular disease, cancer and mortality

    DEFF Research Database (Denmark)

    Vinholt, P J; Hvas, A M; Frederiksen, H

    2016-01-01

    count (100-450×10(9)/L) and mortality, development of future cardiovascular disease (myocardial infarction, ischaemic stroke, or peripheral vascular disease), venous thromboembolism, bleeding or cancer in the general population. MATERIAL AND METHODS: We conducted a register-based cohort study of 21......,252 adults (≥20years) from the Danish General Suburban Population Study (GESUS). Laboratory results from GESUS were linked to information from national registers regarding morbidity and death. Cox proportional hazard regression was conducted with adjustment for age, sex, smoking status, haemoglobin......, leukocyte count, C-reactive protein and Charlson comorbidity index. RESULTS: We found a U-shaped relationship between mortality and platelet count. Mortality was significantly increased for platelet count 300×10(9)/L. When categorizing platelet count using the interval 201-250×10(9)/L...

  11. Use of pliable bags in liquid scintillation counting

    International Nuclear Information System (INIS)

    Simonnet, G.; Jacquet, M.A.; Sharif, A.; Engler, R.

    1981-01-01

    Pliable plastic bags have been used to replace glass or plastic vials for liquid scintillation counting. The two major advantages of this method are the lower cost of the plastic bags and the fact that, per sample, the radioactive waste is significantly reduced. The following parameters have been checked: the impermeability of the bags to various scintillator mixtures and the fact that neither the irregular shape of the bags nor their position in the counting chamber had any effect on the results of the counting. The latter was also constant with time, at least over a period of 10 days. The technique has been used to count the radioactivity of 3 H-DNA precipitates prepared from bacteria and lymphocytes and deposited on filters impregnated with only 200 μl scintillator. It is a method that can be applied to the counting of any samples deposited on filters and insoluble in scintillator. (author)

  12. Computed neutron coincidence counting applied to passive waste assay

    International Nuclear Information System (INIS)

    Bruggeman, M.; Baeten, P.; De Boeck, W.; Carchon, R.

    1997-01-01

    Neutron coincidence counting applied for the passive assay of fissile material is generally realised with dedicated electronic circuits. This paper presents a software based neutron coincidence counting method with data acquisition via a commercial PC-based Time Interval Analyser (TIA). The TIA is used to measure and record all time intervals between successive pulses in the pulse train up to count-rates of 2 Mpulses/s. Software modules are then used to compute the coincidence count-rates and multiplicity related data. This computed neutron coincidence counting (CNCC) offers full access to all the time information contained in the pulse train. This paper will mainly concentrate on the application and advantages of CNCC for the non-destructive assay of waste. An advanced multiplicity selective Rossi-alpha method is presented and its implementation via CNCC demonstrated. 13 refs., 4 figs., 2 tabs

  13. An Automatic Car Counting System Using OverFeat Framework.

    Science.gov (United States)

    Biswas, Debojit; Su, Hongbo; Wang, Chengyi; Blankenship, Jason; Stevanovic, Aleksandar

    2017-06-30

    Automatic car counting is an important component in the automated traffic system. Car counting is very important to understand the traffic load and optimize the traffic signals. In this paper, we implemented the Gaussian Background Subtraction Method and OverFeat Framework to count cars. OverFeat Framework is a combination of Convolution Neural Network (CNN) and one machine learning classifier (like Support Vector Machines (SVM) or Logistic Regression). With this study, we showed another possible application area for the OverFeat Framework. The advantages and shortcomings of the Background Subtraction Method and OverFeat Framework were analyzed using six individual traffic videos with different perspectives, such as camera angles, weather conditions and time of the day. In addition, we compared the two algorithms above with manual counting and a commercial software called Placemeter. The OverFeat Framework showed significant potential in the field of car counting with the average accuracy of 96.55% in our experiment.

  14. Nuclear radiation detector. Realization and study of the G.M. counters with halogens, the multiples anodes

    International Nuclear Information System (INIS)

    Sekhavat, A.

    1975-01-01

    A substantial improvement of the halogene GEIGER-MULLER counters properties has been carried out by the research of new anode forms. This amelioration has been revealed by the comparison of the new counters with the classical ones, absolutely identical as to their size and production. The anodes alone are different

  15. Natural Sources of Radiation Exposure and the Teaching of Radioecology

    Science.gov (United States)

    Anjos, R. M.; Veiga, R.; Carvalho, C.; Sanches, N.; Estellita, L.; Zanuto, P.; Queiroz, E.; Macario, K.

    2008-01-01

    We have developed an experimental activity that introduces concepts of the natural ionizing radiation and its interaction with our contemporary environment that can be used with students from secondary to college level. The experiment is based on the use of traditional and cheap portable Geiger-Muller detectors as survey meters for "in situ"…

  16. Instrument evaluation no.14: Wallac laboratory contamination meter RD 11

    International Nuclear Information System (INIS)

    Burgess, P.H.; Iles, W.J.

    1979-01-01

    An instrument for measuring low level contamination and consisting of a detachable Geiger-Muller tube probe, connected to a rate meter by a coiled extensible tube is described. Facilities and controls, performance, electrical, environmental and mechanical characteristics are included. (UK)

  17. Detection systems for high energy particle producing gaseous ionization

    International Nuclear Information System (INIS)

    Martinez, L.; Duran, I.

    1985-01-01

    This report contains a review on the most used detectors based on the collection of the ionization produced by high energy particles: proportional counters, multiwire proportional chambers, Geiger-Muller counters and drift chambers. In six sections, the fundamental principles, the field configuration and useful gas mixtures, are discussed, most relevant devices are reported along 90 pages with 98 references. (Author) 98 refs

  18. Application of effective variance method for contamination monitor calibration

    International Nuclear Information System (INIS)

    Goncalez, O.L.; Freitas, I.S.M. de.

    1990-01-01

    In this report, the calibration of a thin window Geiger-Muller type monitor for alpha superficial contamination is presented. The calibration curve is obtained by the method of the least-squares fitting with effective variance. The method and the approach for the calculation are briefly discussed. (author)

  19. The assessment of external photon dose rate in the vicinity of nuclear power stations. An intercomparison of different monitoring systems

    DEFF Research Database (Denmark)

    Thompson, I.M.G.; Bøtter-Jensen, L.; Lauterbach, U.

    1993-01-01

    Four environmental dose rate instruments having different detectors, a high pressure ionisation chamber, a Geiger-Muller counter, a proportional counter and a scintillation counter, were used to make continuous measurements over a four month period of the air kerma rate at a location close to a n...

  20. Detection systems for high energy particle producing gaseous ionization; Sistemas de deteccion de particulas de alta energia mediante ionizacion gaseosa

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, L; Duran, I

    1985-07-01

    This report contains a review on the most used detectors based on the collection of the ionization produced by high energy particles: proportional counters, multiwire proportional chambers, Geiger-Muller counters and drift chambers. In six sections, the fundamental principles, the field configuration and useful gas mixtures, are discussed, most relevant devices are reported along 90 pages with 98 references. (Author) 98 refs.

  1. Proposals of counting method for bubble detectors and their intercomparisons

    International Nuclear Information System (INIS)

    Ramalho, Eduardo; Silva, Ademir X.; Bellido, Luis F.; Facure, Alessandro; Pereira, Mario

    2009-01-01

    The study of neutron's spectrometry and dosimetry has become significantly easier due to relatively new devices called bubble detectors. Insensitive to gamma rays and composed by superheated emulsions, they still are subjects of many researches in Radiation Physics and Nuclear Engineering. In bubble detectors, either exposed to more intense neutron fields or for a long time, when more bubbles are produced, the statistical uncertainty during the dosimetric and spectrometric processes is reduced. A proposal of this nature is set up in this work, which presents ways to perform counting processes for bubble detectors and an updated proceeding to get the irradiated detectors' images in order to make the manual counting easier. Twelve BDS detectors were irradiated by RDS111 cyclotron from IEN's (Instituto de Engenharia Nuclear) and photographed using an assembly specially designed for this experiment. Counting was proceeded manually in a first moment; simultaneously, ImagePro was used in order to perform counting automatically. The bubble counting values, either manual or automatic, were compared and the time to get them and their difficult levels as well. After the bubble counting, the detectors' standardizes responses were calculated in both cases, according to BDS's manual and they were also compared. Among the results, the counting on these devices really becomes very hard at a large number of bubbles, besides higher variations in counting of many bubbles. Because of the good agreement between manual counting and the custom program, the last one revealed a good alternative in practical and economical levels. Despite the good results, the custom program needs of more adjustments in order to achieve more accuracy on higher counting on bubble detectors for neutron measurement applications. (author)

  2. Standardization of Ga-68 by coincidence measurements, liquid scintillation counting and 4πγ counting

    International Nuclear Information System (INIS)

    Roteta, Miguel; Peyres, Virginia; Rodríguez Barquero, Leonor; García-Toraño, Eduardo; Arenillas, Pablo; Balpardo, Christian; Rodrígues, Darío; Llovera, Roberto

    2012-01-01

    The radionuclide 68 Ga is one of the few positron emitters that can be prepared in-house without the use of a cyclotron. It disintegrates to the ground state of 68 Zn partially by positron emission (89.1%) with a maximum energy of 1899.1 keV, and partially by electron capture (10.9%). This nuclide has been standardized in the frame of a cooperation project between the Radionuclide Metrology laboratories from CIEMAT (Spain) and CNEA (Argentina). Measurements involved several techniques: 4πβ−γ coincidences, integral gamma counting and Liquid Scintillation Counting using the triple to double coincidence ratio and the CIEMAT/NIST methods. Given the short half-life of the radionuclide assayed, a direct comparison between results from both laboratories was excluded and a comparison of experimental efficiencies of similar NaI detectors was used instead. - Highlights: ► We standardized the positron emitter Ga-68 in a bilateral cooperation. ► We used several techniques, as coincidence, integral gamma and liquid scintillation. ► An efficiency comparison replaced a direct comparison of reference materials.

  3. Bayesian analysis of energy and count rate data for detection of low count rate radioactive sources

    Energy Technology Data Exchange (ETDEWEB)

    Klumpp, John [Colorado State University, Department of Environmental and Radiological Health Sciences, Molecular and Radiological Biosciences Building, Colorado State University, Fort Collins, Colorado, 80523 (United States)

    2013-07-01

    We propose a radiation detection system which generates its own discrete sampling distribution based on past measurements of background. The advantage to this approach is that it can take into account variations in background with respect to time, location, energy spectra, detector-specific characteristics (i.e. different efficiencies at different count rates and energies), etc. This would therefore be a 'machine learning' approach, in which the algorithm updates and improves its characterization of background over time. The system would have a 'learning mode,' in which it measures and analyzes background count rates, and a 'detection mode,' in which it compares measurements from an unknown source against its unique background distribution. By characterizing and accounting for variations in the background, general purpose radiation detectors can be improved with little or no increase in cost. The statistical and computational techniques to perform this kind of analysis have already been developed. The necessary signal analysis can be accomplished using existing Bayesian algorithms which account for multiple channels, multiple detectors, and multiple time intervals. Furthermore, Bayesian machine-learning techniques have already been developed which, with trivial modifications, can generate appropriate decision thresholds based on the comparison of new measurements against a nonparametric sampling distribution. (authors)

  4. Application of PSD for low level alpha counting using liquid scintillation counting

    International Nuclear Information System (INIS)

    Krishnamachari, G.; Vaze, P.K.; Iyer, M.R.

    1989-01-01

    In the liquid scintillator the light produced by alpha particles decays differently than those produced by electrons. Pulse shape discrimination (PSD) methods are employed to estimate low levels of alpha emitting radionuclides by reducing the background due to either beta or gamma events. An attempt is being made to develop a liquid scintillation counting sytem using a simple PSD circuit to achieve a background of 0.01 counts/min. The PSD circuit is based on measuring zero cross over points to differentiate particle types. The input signal is first differentiated by a delay line and subsequently by a RC circuit. The width of the initial part of the doubly differentiated pulse is different for alpha and beta pulses. This width is converted to amplitude by a time-to-amplitude converter (TAC). The higher amplitude pulses from the TAC are due to alpha particles and they are separated by an integral discriminator. The output from the integral discriminator opens a linear gate to record the pulse height spectrum. The figure of merit of the PSD circuit and background in the alpha energy channel have been worked out using different scintillator types. (author). 4 figs

  5. You can count on the motor cortex: Finger counting habits modulate motor cortex activation evoked by numbers

    Science.gov (United States)

    Tschentscher, Nadja; Hauk, Olaf; Fischer, Martin H.; Pulvermüller, Friedemann

    2012-01-01

    The embodied cognition framework suggests that neural systems for perception and action are engaged during higher cognitive processes. In an event-related fMRI study, we tested this claim for the abstract domain of numerical symbol processing: is the human cortical motor system part of the representation of numbers, and is organization of numerical knowledge influenced by individual finger counting habits? Developmental studies suggest a link between numerals and finger counting habits due to the acquisition of numerical skills through finger counting in childhood. In the present study, digits 1 to 9 and the corresponding number words were presented visually to adults with different finger counting habits, i.e. left- and right-starters who reported that they usually start counting small numbers with their left and right hand, respectively. Despite the absence of overt hand movements, the hemisphere contralateral to the hand used for counting small numbers was activated when small numbers were presented. The correspondence between finger counting habits and hemispheric motor activation is consistent with an intrinsic functional link between finger counting and number processing. PMID:22133748

  6. Using DNA to test the utility of pellet-group counts as an index of deer counts

    Science.gov (United States)

    T. J. Brinkman; D. K. Person; W. Smith; F. Stuart Chapin; K. McCoy; M. Leonawicz; K. Hundertmark

    2013-01-01

    Despite widespread use of fecal pellet-group counts as an index of ungulate density, techniques used to convert pellet-group numbers to ungulate numbers rarely are based on counts of known individuals, seldom evaluated across spatial and temporal scales, and precision is infrequently quantified. Using DNA from fecal pellets to identify individual deer, we evaluated the...

  7. High Reproducibility of ELISPOT Counts from Nine Different Laboratories

    Directory of Open Access Journals (Sweden)

    Srividya Sundararaman

    2015-01-01

    Full Text Available The primary goal of immune monitoring with ELISPOT is to measure the number of T cells, specific for any antigen, accurately and reproducibly between different laboratories. In ELISPOT assays, antigen-specific T cells secrete cytokines, forming spots of different sizes on a membrane with variable background intensities. Due to the subjective nature of judging maximal and minimal spot sizes, different investigators come up with different numbers. This study aims to determine whether statistics-based, automated size-gating can harmonize the number of spot counts calculated between different laboratories. We plated PBMC at four different concentrations, 24 replicates each, in an IFN-γ ELISPOT assay with HCMV pp65 antigen. The ELISPOT plate, and an image file of the plate was counted in nine different laboratories using ImmunoSpot® Analyzers by (A Basic Count™ relying on subjective counting parameters set by the respective investigators and (B SmartCount™, an automated counting protocol by the ImmunoSpot® Software that uses statistics-based spot size auto-gating with spot intensity auto-thresholding. The average coefficient of variation (CV for the mean values between independent laboratories was 26.7% when counting with Basic Count™, and 6.7% when counting with SmartCount™. Our data indicates that SmartCount™ allows harmonization of counting ELISPOT results between different laboratories and investigators.

  8. Determining Gate Count Reliability in a Library Setting

    Directory of Open Access Journals (Sweden)

    Jeffrey Phillips

    2016-09-01

    Full Text Available Objective – Patron counts are a common form of measurement for library assessment. To develop accurate library statistics, it is necessary to determine any differences between various counting devices. A yearlong comparison between card reader turnstiles and laser gate counters in a university library sought to offer a standard percentage of variance and provide suggestions to increase the precision of counts. Methods – The collection of library exit counts identified the differences between turnstile and laser gate counter data. Statistical software helped to eliminate any inaccuracies in the collection of turnstile data, allowing this data set to be the base for comparison. Collection intervals were randomly determined and demonstrated periods of slow, average, and heavy traffic. Results – After analyzing 1,039,766 patron visits throughout a year, the final totals only showed a difference of .43% (.0043 between the two devices. The majority of collection periods did not exceed a difference of 3% between the counting instruments. Conclusion – Turnstiles card readers and laser gate counters provide similar levels of reliability when measuring patron activity. Each system has potential counting inaccuracies, but several methods exist to create more precise totals. Turnstile card readers are capable of offering greater detail involving patron identity, but their high cost makes them inaccessible for libraries with lower budgets. This makes laser gate counters an affordable alternative for reliable patron counting in an academic library.

  9. Tutorial on X-ray photon counting detector characterization.

    Science.gov (United States)

    Ren, Liqiang; Zheng, Bin; Liu, Hong

    2018-01-01

    Recent advances in photon counting detection technology have led to significant research interest in X-ray imaging. As a tutorial level review, this paper covers a wide range of aspects related to X-ray photon counting detector characterization. The tutorial begins with a detailed description of the working principle and operating modes of a pixelated X-ray photon counting detector with basic architecture and detection mechanism. Currently available methods and techniques for charactering major aspects including energy response, noise floor, energy resolution, count rate performance (detector efficiency), and charge sharing effect of photon counting detectors are comprehensively reviewed. Other characterization aspects such as point spread function (PSF), line spread function (LSF), contrast transfer function (CTF), modulation transfer function (MTF), noise power spectrum (NPS), detective quantum efficiency (DQE), bias voltage, radiation damage, and polarization effect are also remarked. A cadmium telluride (CdTe) pixelated photon counting detector is employed for part of the characterization demonstration and the results are presented. This review can serve as a tutorial for X-ray imaging researchers and investigators to understand, operate, characterize, and optimize photon counting detectors for a variety of applications.

  10. Machine for controlling band-type 'essuimatic' hand towels (1962); Machine a controler les essuie-mains en bande du type essuimatic (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Cottignies, S; Ortiz, J [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1962-07-01

    This machine is designed to control the band-towels in the form of 40 meters bands equipping the 'Essuimatic' distributors. It controls automatically the {alpha} and {beta}-{gamma} activity. The towel is driven by motors and passes under Geiger-Muller counters and then between zinc sulphide scintillators in conjunction with photomultipliers. Two distinct counting systems measure the total activity deposited on the cloth and, in order to give an idea of the distribution of this activity, count also the number of marks, that is, the number of times that the counting rate of the probes is above a certain value. After the passage of the cloth it is thus possible to know whether the count corresponding to the whole band is greater than that due to just the counter movement, and also whether this counting rate has not occasionally been greater than the average rate; it is thus possible to detect weak local contamination which could have been missed in an overall measurement of the cloth. (authors) [French] Cette machine est destinee a controler les linges essuie-mains sous forme de bande de 40 metres de longueur equipant les distributeurs 'ESSUIMATIC'. Elle effectue automatiquement un controle en {alpha} et en {beta}-{gamma}. Le linge entraine par un moteur passe. sous des compteurs Geiger-Muller, puis entre des scintillateurs au sulfure de zinc associes a des photomultiplicateurs. Deux chaines de comptage distinctes comptent l'activite totale deposee sur le linge et, en outre, pour donner une idee de la repartition de cette activite, elles comptent le nombre de taches, c'est-a-dire le nombre de fois que le taux de comptage des sondes est superieur a une certaine valeur. A la fin du passage du linge, il est donc possible de connaitre si le comptage correspondant a toute la bande est superieur a celui du au mouvement propre seul des compteurs et egalement de savoir si parfois ce taux de comptage n'a pas ete superieur au taux de comptage moyen, ce qui permet de detecter de

  11. Learning to count begins in infancy: evidence from 18 month olds' visual preferences.

    Science.gov (United States)

    Slaughter, Virginia; Itakura, Shoji; Kutsuki, Aya; Siegal, Michael

    2011-10-07

    We used a preferential looking paradigm to evaluate infants' preferences for correct versus incorrect counting. Infants viewed a video depicting six fish. In the correct counting sequence, a hand pointed to each fish in turn, accompanied by verbal counting up to six. In the incorrect counting sequence, the hand moved between two of the six fish while there was still verbal counting to six, thereby violating the one-to-one correspondence principle of correct counting. Experiment 1 showed that Australian 18 month olds, but not 15 month olds, significantly preferred to watch the correct counting sequence. In experiment 2, Australian infants' preference for correct counting disappeared when the count words were replaced by beeps or by Japanese count words. In experiment 3, Japanese 18 month olds significantly preferred the correct counting video only when counting was in Japanese. These results show that infants start to acquire the abstract principles governing correct counting prior to producing any counting behaviour.

  12. Application of RI-counting method for posttraumatic CSF rhinorrhea

    International Nuclear Information System (INIS)

    Itoh, Takahiko; Terai, Yoshinori; Fujimoto, Shunichiro; Kawauchi, Masamitsu.

    1987-01-01

    Numerous techniques and procedures have been reported for the evaluation of CSF fistulas. Especially metrizamide CT cisternography and radioisotope (RI) cisternography have been reported to be reliable for localizing the site of CSF leakage, however, it has been difficult to diagnose the existence and the site of CSF leakages in some cases. RI-counting method, measuring RI-count of intranasal cotton pledgets after the intrathecal injection of RI ( 111 In-DTPA) is thought to be the most reliable method for detecting the presence of CSF leakage in these cases. We used six cotton pledgets which were inserted into upper, middle, and lower meatuses on both side. Because the site of pledgets with ghest RI-count has anatomical relationship to the opening of the paranasal sinus, we can surmise the leakage of dural defect and CSF leakage. RI counting method was applied to two patients in whom it was difficult to diagnose the presence of CSF leakage with other procedures. The patients were free in position for four hours after the intrathecal injection of RI, and in the prone position for 30 minutes before RI-counting of intranasal cotton pledgets. After measuring the RI-counts of six pledgets, the counts were compared with each other. The cotton pledget inserted into left middle meatus showed the highest count in both cases. From this result and finding of conventional skull tomography we speculated the site of CSF leakage to be frontal sinus or ethmoid sinus. Operation demonstrated the opening of dura into the frontal sinus in one case, and ethmoid sinus in another case. As mentioned above, RI-counting method has the advantages of detecting the existence and the site of CSF leakage. (author)

  13. Study on advancement of in vivo counting using mathematical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kinase, Sakae [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-05-01

    To obtain an assessment of the committed effective dose, individual monitoring for the estimation of intakes of radionuclides is required. For individual monitoring of exposure to intakes of radionuclides, direct measurement of radionuclides in the body - in vivo counting- is very useful. To advance in a precision in vivo counting which fulfills the requirements of ICRP 1990 recommendations, some problems, such as the investigation of uncertainties in estimates of body burdens by in vivo counting, and the selection of the way to improve the precision, have been studied. In the present study, a calibration technique for in vivo counting application using Monte Carlo simulation was developed. The advantage of the technique is that counting efficiency can be obtained for various shapes and sizes that are very difficult to change for phantoms. To validate the calibration technique, the response functions and counting efficiencies of a whole-body counter installed in JAERI were evaluated using the simulation and measurements. Consequently, the calculations are in good agreement with the measurements. The method for the determination of counting efficiency curves as a function of energy was developed using the present technique and a physiques correction equation was derived from the relationship between parameters of correction factor and counting efficiencies of the JAERI whole-body counter. The uncertainties in body burdens of {sup 137}Cs estimated with the JAERI whole-body counter were also investigated using the Monte Carlo simulation and measurements. It was found that the uncertainties of body burdens estimated with the whole-body counter are strongly dependent on various sources of uncertainty such as radioactivity distribution within the body and counting statistics. Furthermore, the evaluation method of the peak efficiencies of a Ge semi-conductor detector was developed by Monte Carlo simulation for optimum arrangement of Ge semi-conductor detectors for

  14. Fast sequential Monte Carlo methods for counting and optimization

    CERN Document Server

    Rubinstein, Reuven Y; Vaisman, Radislav

    2013-01-01

    A comprehensive account of the theory and application of Monte Carlo methods Based on years of research in efficient Monte Carlo methods for estimation of rare-event probabilities, counting problems, and combinatorial optimization, Fast Sequential Monte Carlo Methods for Counting and Optimization is a complete illustration of fast sequential Monte Carlo techniques. The book provides an accessible overview of current work in the field of Monte Carlo methods, specifically sequential Monte Carlo techniques, for solving abstract counting and optimization problems. Written by authorities in the

  15. Exponential Martingales and Changes of Measure for Counting Processes

    DEFF Research Database (Denmark)

    Sokol, Alexander; Hansen, Niels Richard

    2015-01-01

    We give sufficient criteria for the Doléans-Dade exponential of a stochastic integral with respect to a counting process local martingale to be a true martingale. The criteria are adapted particularly to the case of counting processes and are sufficiently weak to be useful and verifiable, as we i...... illustrate by several examples. In particular, the criteria allow for the construction of for example nonexplosive Hawkes processes, counting processes with stochastic intensities depending on diffusion processes as well as inhomogeneous finite-state Markov processes....

  16. Red Blood Cell Count Automation Using Microscopic Hyperspectral Imaging Technology.

    Science.gov (United States)

    Li, Qingli; Zhou, Mei; Liu, Hongying; Wang, Yiting; Guo, Fangmin

    2015-12-01

    Red blood cell counts have been proven to be one of the most frequently performed blood tests and are valuable for early diagnosis of some diseases. This paper describes an automated red blood cell counting method based on microscopic hyperspectral imaging technology. Unlike the light microscopy-based red blood count methods, a combined spatial and spectral algorithm is proposed to identify red blood cells by integrating active contour models and automated two-dimensional k-means with spectral angle mapper algorithm. Experimental results show that the proposed algorithm has better performance than spatial based algorithm because the new algorithm can jointly use the spatial and spectral information of blood cells.

  17. The distribution of controlled drugs on banknotes via counting machines.

    Science.gov (United States)

    Carter, James F; Sleeman, Richard; Parry, Joanna

    2003-03-27

    Bundles of paper, similar to sterling banknotes, were counted in banks in England and Wales. Subsequent analysis showed that the counting process, both by machine and by hand, transferred nanogram amounts of cocaine to the paper. Crystalline material, similar to cocaine hydrochloride, could be observed on the surface of the paper following counting. The geographical distribution of contamination broadly followed Government statistics for cocaine usage within the UK. Diacetylmorphine, Delta(9)-tetrahydrocannabinol (THC) and 3,4-methylenedioxymethylamphetamine (MDMA) were not detected during this study.

  18. Flow cytometric bacterial cell counts challenge conventional heterotrophic plate counts for routine microbiological drinking water monitoring

    KAUST Repository

    Van Nevel, S.

    2017-02-08

    Drinking water utilities and researchers continue to rely on the century-old heterotrophic plate counts (HPC) method for routine assessment of general microbiological water quality. Bacterial cell counting with flow cytometry (FCM) is one of a number of alternative methods that challenge this status quo and provide an opportunity for improved water quality monitoring. After more than a decade of application in drinking water research, FCM methodology is optimised and established for routine application, supported by a considerable amount of data from multiple full-scale studies. Bacterial cell concentrations obtained by FCM enable quantification of the entire bacterial community instead of the minute fraction of cultivable bacteria detected with HPC (typically < 1% of all bacteria). FCM measurements are reproducible with relative standard deviations below 3% and can be available within 15 min of samples arriving in the laboratory. High throughput sample processing and complete automation are feasible and FCM analysis is arguably less expensive than HPC when measuring more than 15 water samples per day, depending on the laboratory and selected staining procedure(s). Moreover, many studies have shown FCM total (TCC) and intact (ICC) cell concentrations to be reliable and robust process variables, responsive to changes in the bacterial abundance and relevant for characterising and monitoring drinking water treatment and distribution systems. The purpose of this critical review is to initiate a constructive discussion on whether FCM could replace HPC in routine water quality monitoring. We argue that FCM provides a faster, more descriptive and more representative quantification of bacterial abundance in drinking water.

  19. Flow cytometric bacterial cell counts challenge conventional heterotrophic plate counts for routine microbiological drinking water monitoring

    KAUST Repository

    Van Nevel, S.; Koetzsch, S.; Proctor, C.R.; Besmer, M.D.; Prest, E.I.; Vrouwenvelder, Johannes S.; Knezev, A.; Boon, N.; Hammes, F.

    2017-01-01

    Drinking water utilities and researchers continue to rely on the century-old heterotrophic plate counts (HPC) method for routine assessment of general microbiological water quality. Bacterial cell counting with flow cytometry (FCM) is one of a number of alternative methods that challenge this status quo and provide an opportunity for improved water quality monitoring. After more than a decade of application in drinking water research, FCM methodology is optimised and established for routine application, supported by a considerable amount of data from multiple full-scale studies. Bacterial cell concentrations obtained by FCM enable quantification of the entire bacterial community instead of the minute fraction of cultivable bacteria detected with HPC (typically < 1% of all bacteria). FCM measurements are reproducible with relative standard deviations below 3% and can be available within 15 min of samples arriving in the laboratory. High throughput sample processing and complete automation are feasible and FCM analysis is arguably less expensive than HPC when measuring more than 15 water samples per day, depending on the laboratory and selected staining procedure(s). Moreover, many studies have shown FCM total (TCC) and intact (ICC) cell concentrations to be reliable and robust process variables, responsive to changes in the bacterial abundance and relevant for characterising and monitoring drinking water treatment and distribution systems. The purpose of this critical review is to initiate a constructive discussion on whether FCM could replace HPC in routine water quality monitoring. We argue that FCM provides a faster, more descriptive and more representative quantification of bacterial abundance in drinking water.

  20. A new programmable zone dosimeter for operational monitoring and measurement of external gamma radiation

    International Nuclear Information System (INIS)

    Toledo Acosta, Rene; Arteche Diaz, Raul; Mesa Perez, Guillermo; Fernandez Llanez, Sandra; Tamayo Garcia, Jose Antonio; Alonso Villanueva, Gilberto

    2010-01-01

    The detection and the measurement of the nuclear radiations have turn into an important item in the nuclear detectors application and specifically the Geiger Muller ones. Coming from theirs high detection sensibility, robust construction and relative simplicity of the associated circuit, the Geiger Tubes are still one of the most widely used detectors in all the application areas regarding physics and nuclear investigations A new design instrument is presented to be measures the ambient dose of external (gamma) radiation since 10 mSv/h. It consists of three elements: Geiger-Muller detector, the electronic board for the acquisition and control and the application software. The instrument communicates trough a USB interface to the Personal Computer only for adjust calibration parameters. The software was developed in the C programming language using PICC4, 08 compilers. (author)