Reference ranges for blood concentrations of eosinophils and monocytes during the neonatal period defined from over 63 000 records in a multihospital health-care system.

Science.gov (United States)

Christensen, R D; Jensen, J; Maheshwari, A; Henry, E

2010-08-01

Blood concentrations of eosinophils and monocytes are part of the complete blood count. Reference ranges for these concentrations during the neonatal period, established by very large sample sizes and modern methods, are needed for identifying abnormally low or high values. We constructed reference ranges for eosinophils per microl and monocytes per microl among neonates of 22 to 42 weeks of gestation, on the day of birth, and also during 28 days after birth. Data were obtained from archived electronic records over an eight and one-half-year period in a multihospital health-care system. In keeping with the reference range concept, values were excluded from neonates with a diagnosis of infection or necrotizing enterocolitis (NEC). Eosinophils and monocytes per microl of blood were electronically retrieved from 96 162 records, of which 63 371 that lacked a diagnosis of infection or NEC were included in this reference range report. The mean value for eosinophils per microl on the day of birth increased linearly between 22 and 42 weeks of gestation, as did the 5 and 95% values. The reference range at 40 weeks was 140 to 1300 microl(-1) (mean 550 microl(-1)). Similarly, the mean value for monocytes increased linearly over this interval, with a reference range at 40 weeks of 300 to 3300 microl(-1) (mean 1400 microl(-1)). Over the first 4 weeks after birth, no appreciable change was observed in 5% limit and mean eosinophil count, with a slight increase in the 95% limit in week 4. A slight increase in monocyte count was observed during the first 2 weeks after birth. The results of this analysis describe reference ranges for blood concentrations of eosinophils and monocytes during the neonatal period. Additional study is needed for determining the relevance of values falling outside the reference range.

Unsupervised Ensemble Anomaly Detection Using Time-Periodic Packet Sampling

Science.gov (United States)

Uchida, Masato; Nawata, Shuichi; Gu, Yu; Tsuru, Masato; Oie, Yuji

We propose an anomaly detection method for finding patterns in network traffic that do not conform to legitimate (i.e., normal) behavior. The proposed method trains a baseline model describing the normal behavior of network traffic without using manually labeled traffic data. The trained baseline model is used as the basis for comparison with the audit network traffic. This anomaly detection works in an unsupervised manner through the use of time-periodic packet sampling, which is used in a manner that differs from its intended purpose — the lossy nature of packet sampling is used to extract normal packets from the unlabeled original traffic data. Evaluation using actual traffic traces showed that the proposed method has false positive and false negative rates in the detection of anomalies regarding TCP SYN packets comparable to those of a conventional method that uses manually labeled traffic data to train the baseline model. Performance variation due to the probabilistic nature of sampled traffic data is mitigated by using ensemble anomaly detection that collectively exploits multiple baseline models in parallel. Alarm sensitivity is adjusted for the intended use by using maximum- and minimum-based anomaly detection that effectively take advantage of the performance variations among the multiple baseline models. Testing using actual traffic traces showed that the proposed anomaly detection method performs as well as one using manually labeled traffic data and better than one using randomly sampled (unlabeled) traffic data.

Dispersion of the intrinsic neuronal periods affects the relationship of the entrainment range to the coupling strength in the suprachiasmatic nucleus

Science.gov (United States)

Gu, Changgui; Yang, Huijie; Wang, Man

2017-11-01

Living beings on the Earth are subjected to and entrained (synchronized) to the natural 24-h light-dark cycle. Interestingly, they can also be entrained to an external artificial cycle of non-24-h periods. The range of these periods is called the entrainment range and it differs among species. In mammals, the entrainment range is regulated by a main clock located in the suprachiasmatic nucleus (SCN) which is composed of 10 000 neurons in the brain. Previous works have found that the entrainment range depends on the cellular coupling strength in the SCN. In particular, the entrainment range decreases with the increase of the cellular coupling strength, provided that all the neuronal oscillators are identical. However, the SCN neurons differ in the intrinsic periods that follow a normal distribution in a range from 22 to 28 h. In the present study, taking the dispersion of the intrinsic neuronal periods into account, we examined the relationship between the entrainment range and the coupling strength. Results from numerical simulations and theoretical analyses both show that the relationship is altered to be paraboliclike if the intrinsic neuronal periods are nonidentical, and the maximal entrainment range is obtained with a suitable coupling strength. Our results shed light on the role of the cellular coupling in the entrainment ability of the SCN network.

Wuchereria bancrofti in Tanzania: microfilarial periodicity and effect of blood sampling time on microfilarial intensities

DEFF Research Database (Denmark)

Simonsen, Poul Erik; Niemann, L.; Meyrowitsch, Dan Wolf

1997-01-01

The circadian periodicity of Wuchereria bancrofti microfilarial (mf) intensities in peripheral blood was analysed in a group of infected individuals from an endemic community in north-eastern Tanzania. The mf density was quantified at two-hourly intervals for 24 hours. A clear nocturnal periodic...... of blood sampling before peak time is discussed, and the importance of taking sampling time into consideration when analysing data from epidemiological studies is emphasized. A simple method is devised which can be used to adjust for the influence of time on mf intensities, in studies where accurate...... information on mf intensities is necessary, and where it is impossible to obtain all samples at peak time....

Sensitivity Range Analysis of Infrared (IR) Transmitter and Receiver Sensor to Detect Sample Position in Automatic Sample Changer

International Nuclear Information System (INIS)

Syirrazie Che Soh; Nolida Yussup; Nur Aira Abdul Rahman; Maslina Ibrahim

2016-01-01

Sensitivity range of IR Transmitter and Receiver Sensor influences the effectiveness of the sensor to detect position of a sample. Then the purpose of this analysis is to determine the suitable design and specification the electronic driver of the sensor to gain appropriate sensitivity range for required operation. The related activities to this analysis cover electronic design concept and specification, calibration of design specification and evaluation on design specification for required application. (author)

Radon exhalation rates from slate stone samples in Aravali Range in Haryana

International Nuclear Information System (INIS)

Upadhyay, S.B.; Kant, K.; Chakarvarti, S.K.

2012-01-01

The slate stone tiles are very popular in covering the walls of the rooms. Radon is released into ambient air from slate stones due to ubiquitous uranium and radium in them, thus increasing the airborne radon concentration. The radioactivity in slates stones is related to radioactivity in the rocks from which the slate stone tiles are formed. In the present investigation, the radon emanated from slate stone samples collected from different slate mines in Aravali range of hills in the Haryana state of Northern India has been estimated. For the measurement of radon concentration emanated from these samples, alpha-sensitive LR-115 type II plastic track detectors have been used. The alpha particles emitted from the radon form tracks in these detectors. After chemical etching the track density of registered tracks is used to calculate radon concentration and exhalation rates of radon using required formulae. The measurements indicate normal to some higher levels of radon concentration emanated from the slat stone samples collected from Aravali range of hills in north India. The results will be discussed in full paper. (author)

Representative process sampling - in practice

DEFF Research Database (Denmark)

Esbensen, Kim; Friis-Pedersen, Hans Henrik; Julius, Lars Petersen

2007-01-01

Didactic data sets representing a range of real-world processes are used to illustrate "how to do" representative process sampling and process characterisation. The selected process data lead to diverse variogram expressions with different systematics (no range vs. important ranges; trends and....../or periodicity; different nugget effects and process variations ranging from less than one lag to full variogram lag). Variogram data analysis leads to a fundamental decomposition into 0-D sampling vs. 1-D process variances, based on the three principal variogram parameters: range, sill and nugget effect...

Rescaled Range Analysis and Detrended Fluctuation Analysis: Finite Sample Properties and Confidence Intervals

Czech Academy of Sciences Publication Activity Database

Krištoufek, Ladislav

4/2010, č. 3 (2010), s. 236-250 ISSN 1802-4696 R&D Projects: GA ČR GD402/09/H045; GA ČR GA402/09/0965 Grant - others:GA UK(CZ) 118310 Institutional research plan: CEZ:AV0Z10750506 Keywords : rescaled range analysis * detrended fluctuation analysis * Hurst exponent * long-range dependence Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2010/E/kristoufek-rescaled range analysis and detrended fluctuation analysis finite sample properties and confidence intervals.pdf

Event Processing and Variable Part of Sample Period Determining in Combined Systems Using GA

Science.gov (United States)

Strémy, Maximilián; Závacký, Pavol; Jedlička, Martin

2011-01-01

This article deals with combined dynamic systems and usage of modern techniques in dealing with these systems, focusing particularly on sampling period design, cyclic processing tasks and related processing algorithms in the combined event management systems using genetic algorithms.

Measuring modulated luminescence using non-modulated stimulation: Ramping the sample period

DEFF Research Database (Denmark)

Poolton, N.R.J.; Bøtter-Jensen, L.; Andersen, C.E.

2003-01-01

. Directly analogous results to LM-OSL can, however, be achieved with non-modulated excitation sources, by ramping the sample period (RSP) of luminescence detection. RSP-OSL has the distinct advantage over LM-OSL in that, since the excitation remains at full power, data accumulation times (that can...... be considerable) can be reduced by typically 50%. RSP methods are universally applicable and can be employed, for example, where the excitation source is constant heat, rather than light: here, iso-thermal decay of phosphorescence becomes recorded as a sequence of peaks, corresponding to de-trapping of charge...

Unambiguous range-Doppler LADAR processing using 2 giga-sample-per-second noise waveforms

International Nuclear Information System (INIS)

Cole, Z.; Roos, P.A.; Berg, T.; Kaylor, B.; Merkel, K.D.; Babbitt, W.R.; Reibel, R.R.

2007-01-01

We demonstrate sub-nanosecond range and unambiguous sub-50-Hz Doppler resolved laser radar (LADAR) measurements using spectral holographic processing in rare-earth ion doped crystals. The demonstration utilizes pseudo-random-noise 2 giga-sample-per-second baseband waveforms modulated onto an optical carrier

Unambiguous range-Doppler LADAR processing using 2 giga-sample-per-second noise waveforms

Energy Technology Data Exchange (ETDEWEB)

Cole, Z. [S2 Corporation, 2310 University Way 4-1, Bozeman, MT 59715 (United States)]. E-mail: cole@s2corporation.com; Roos, P.A. [Spectrum Lab, Montana State University, P.O. Box 173510, Bozeman, MT 59717 (United States); Berg, T. [S2 Corporation, 2310 University Way 4-1, Bozeman, MT 59715 (United States); Kaylor, B. [S2 Corporation, 2310 University Way 4-1, Bozeman, MT 59715 (United States); Merkel, K.D. [S2 Corporation, 2310 University Way 4-1, Bozeman, MT 59715 (United States); Babbitt, W.R. [Spectrum Lab, Montana State University, P.O. Box 173510, Bozeman, MT 59717 (United States); Reibel, R.R. [S2 Corporation, 2310 University Way 4-1, Bozeman, MT 59715 (United States)

2007-11-15

We demonstrate sub-nanosecond range and unambiguous sub-50-Hz Doppler resolved laser radar (LADAR) measurements using spectral holographic processing in rare-earth ion doped crystals. The demonstration utilizes pseudo-random-noise 2 giga-sample-per-second baseband waveforms modulated onto an optical carrier.

Long-range correlations and asymmetry in the Bitcoin market

Science.gov (United States)

Alvarez-Ramirez, J.; Rodriguez, E.; Ibarra-Valdez, C.

2018-02-01

This work studies long-range correlations and informational efficiency of the Bitcoin market for the period from June 30, 2013 to June 3rd, 2017. To this end, the detrended fluctuation analysis (DFA) was implemented over sliding windows to estimate long-range correlations for price returns. It was found that the Bitcoin market exhibits periods of efficiency alternating with periods where the price dynamics are driven by anti-persistence. The pattern is replicated by prices samples at day, hour and second frequencies. The Bitcoin market also presents asymmetric correlations with respect to increasing and decreasing price trending, with the former trend linked to anti-persistence of returns dynamics.

Spacecraft Trajectory Estimation Using a Sampled-Data Extended Kalman Filter with Range-Only Measurements

National Research Council Canada - National Science Library

Erwin, R. S; Bernstein, Dennis S

2005-01-01

.... In this paper we use a sampled-data extended Kalman Filter to estimate the trajectory or a target satellite when only range measurements are available from a constellation or orbiting spacecraft...

Values Education in Ottoman Empire in the Second Constitutional Period: A Sample Lesson

Science.gov (United States)

Oruc, Sahin; Ilhan, Genc Osman

2015-01-01

Values education holds a significant place in an education environment and many studies are carried out about this new subject area. The aim of this study is to define how the subject of "values education" is handled in a sample lesson designed in the period of Constitution II in the Ottoman Empire. In this study, the lesson plan in the…

Study of uranium mineralization in rock samples from marwat range bannu basin by fission track analysis technique

International Nuclear Information System (INIS)

Qureshi, A.Z.; Ullah, K.; Ullah, N.; Akram, M.

2004-07-01

The Geophysics Division, Atomic Energy Minerals Centre (AEMC), Lahore has planned a uranium exploration program in Marwat Range, Bannu Basin. In this connection 30 thin sections of rock samples, collected from four areas; namely, Darra Tang, Simukili, Karkanwal and Sheikhillah from Marwat Range, and one from Salt Range were provided to Nuclear Geology Group of Physics Research Division, PINSTECH for the study of nature and mechanism of uranium mineralization These studies are aimed to help in designing uranium exploration strategy by providing the loci of uranium sources in the Marwat and Salt Ranges. The samples have been studied using fission track analysis technique. (author)

Estimating the sample mean and standard deviation from the sample size, median, range and/or interquartile range

OpenAIRE

Wan, Xiang; Wang, Wenqian; Liu, Jiming; Tong, Tiejun

2014-01-01

Background In systematic reviews and meta-analysis, researchers often pool the results of the sample mean and standard deviation from a set of similar clinical trials. A number of the trials, however, reported the study using the median, the minimum and maximum values, and/or the first and third quartiles. Hence, in order to combine results, one may have to estimate the sample mean and standard deviation for such trials. Methods In this paper, we propose to improve the existing literature in ...

Revisiting random walk based sampling in networks: evasion of burn-in period and frequent regenerations.

Science.gov (United States)

Avrachenkov, Konstantin; Borkar, Vivek S; Kadavankandy, Arun; Sreedharan, Jithin K

2018-01-01

In the framework of network sampling, random walk (RW) based estimation techniques provide many pragmatic solutions while uncovering the unknown network as little as possible. Despite several theoretical advances in this area, RW based sampling techniques usually make a strong assumption that the samples are in stationary regime, and hence are impelled to leave out the samples collected during the burn-in period. This work proposes two sampling schemes without burn-in time constraint to estimate the average of an arbitrary function defined on the network nodes, for example, the average age of users in a social network. The central idea of the algorithms lies in exploiting regeneration of RWs at revisits to an aggregated super-node or to a set of nodes, and in strategies to enhance the frequency of such regenerations either by contracting the graph or by making the hitting set larger. Our first algorithm, which is based on reinforcement learning (RL), uses stochastic approximation to derive an estimator. This method can be seen as intermediate between purely stochastic Markov chain Monte Carlo iterations and deterministic relative value iterations. The second algorithm, which we call the Ratio with Tours (RT)-estimator, is a modified form of respondent-driven sampling (RDS) that accommodates the idea of regeneration. We study the methods via simulations on real networks. We observe that the trajectories of RL-estimator are much more stable than those of standard random walk based estimation procedures, and its error performance is comparable to that of respondent-driven sampling (RDS) which has a smaller asymptotic variance than many other estimators. Simulation studies also show that the mean squared error of RT-estimator decays much faster than that of RDS with time. The newly developed RW based estimators (RL- and RT-estimators) allow to avoid burn-in period, provide better control of stability along the sample path, and overall reduce the estimation time. Our

Simulation of electron transport in GaAs/AlAs superlattices with a small number of periods for the THz frequency range

International Nuclear Information System (INIS)

Pavelyev, D. G.; Vasilev, A. P.; Kozlov, V. A.; Koschurinov, Yu. I.; Obolenskaya, E. S.; Obolensky, S. V.; Ustinov, V. M.

2016-01-01

The electron transport in superlattices based on GaAs/AlAs heterostructures with a small number of periods (6 periods) is calculated by the Monte Carlo method. These superlattices are used in terahertz diodes for the frequency stabilization of quantum cascade lasers in the range up to 4.7 THz. The band structure of superlattices with different numbers of AlAs monolayers is considered and their current–voltage characteristics are calculated. The calculated current–voltage characteristics are compared with the experimental data. The possibility of the efficient application of these superlattices in the THz frequency range is established both theoretically and experimentally.

Periodic long-range transport in a large volume dc glow discharge dusty plasma

International Nuclear Information System (INIS)

Thomas, Edward Jr.; Amatucci, William E.; Compton, Christopher; Christy, Brian; Jackson, Jon David

2003-01-01

In an earlier paper, the authors reported on observations of a variety of particle transport phenomena observed in DUPLEX--the DUsty PLasma EXperiment at the Naval Research Laboratory [E. Thomas, Jr., W. E. Amatucci, C. Compton, and B. Christy, Phys. Plasmas 9, 3154 (2002)]. DUPLEX is a large, transparent polycarbonate cylinder that is 40 cm in radius and 80 cm in height. dc glow discharge argon plasmas are generated in DUPLEX. In this paper, the authors expand upon one particular feature of particle transport in DUPLEX, the long-range (i.e., greater than 15 cm), periodic (T∼2.5 min) transport of suspended alumina particles through the plasma. A detailed description of this particle motion through the plasma is presented. Finally, a qualitative model describing the phenomena that lead to this transport is also given

Automated Sampling and Extraction of Krypton from Small Air Samples for Kr-85 Measurement Using Atom Trap Trace Analysis

International Nuclear Information System (INIS)

Hebel, S.; Hands, J.; Goering, F.; Kirchner, G.; Purtschert, R.

2015-01-01

Atom-Trap-Trace-Analysis (ATTA) provides the capability of measuring the Krypton-85 concentration in microlitre amounts of krypton extracted from air samples of about 1 litre. This sample size is sufficiently small to allow for a range of applications, including on-site spot sampling and continuous sampling over periods of several hours. All samples can be easily handled and transported to an off-site laboratory for ATTA measurement, or stored and analyzed on demand. Bayesian sampling methodologies can be applied by blending samples for bulk measurement and performing in-depth analysis as required. Prerequisite for measurement is the extraction of a pure krypton fraction from the sample. This paper introduces an extraction unit able to isolate the krypton in small ambient air samples with high speed, high efficiency and in a fully automated manner using a combination of cryogenic distillation and gas chromatography. Air samples are collected using an automated smart sampler developed in-house to achieve a constant sampling rate over adjustable time periods ranging from 5 minutes to 3 hours per sample. The smart sampler can be deployed in the field and operate on battery for one week to take up to 60 air samples. This high flexibility of sampling and the fast, robust sample preparation are a valuable tool for research and the application of Kr-85 measurements to novel Safeguards procedures. (author)

Sampling and instrumentation requirements for long-range D and D activities at INEL

International Nuclear Information System (INIS)

Ahlquist, A.J.

1985-01-01

Assistance was requested to help determine sampling and instrumentation requirements for the long-range decontamination and decommissioning activities at the Idaho National Engineering Laboratory. Through a combination of literature review, visits to other DOE contractors, and a determination of the needs for the INEL program, a draft report has been prepared that is now under review. The final report should be completed in FY 84

Maintaining continuity of knowledge on safeguards samples

International Nuclear Information System (INIS)

Franssen, F.; Islam, A.B.M.N.; Sonnier, C.; Schoeneman, J.L.; Baumann, M.

1992-01-01

The conclusions of the vulnerability test on VOPAN (verification of Operator's Analysis) as conducted at Safeguards Analytical Laboratory (ASA) at Seibersdorf, Austria in October 1990 and documented in STR-266, indicate that ''whenever samples are taken for safeguards purposes extreme care must be taken to ensure that they have not been interfered with during the sample taking, transportation, storage or sample preparation process.'' Indeed there exist a number of possibilities to alter the content of a safeguards sample vial from the moment of sampling up to the arrival of the treated (or untreated) sample at SAL. The time lapse between these two events can range from a few days up to months. The sample history over this period can be subdivided into three main sub-periods: (1) the period from when the sampling activities are commenced up to the treatment in the operator's laboratory, (2) during treatment of samples in the operator's laboratory, and finally, (3) the period between that treatment and the arrival of the sample at SAL. A combined effort between the Agency and the United States Support Program to the Agency (POTAS) has resulted in two active tasks and one proposed task to investigate improving the maintenance of continuity of knowledge on safeguards samples during the entire period of their existence. This paper describes the use of the Sample Vial Secure Container (SVSC), of the Authenticated Secure Container System (ASCS), and of the Secure Container for Storage and Transportation of samples (SCST) to guarantee that a representative portion of the solution sample will be received at SAL

Measurement of peak impact loads differ between accelerometers - Effects of system operating range and sampling rate.

Science.gov (United States)

Ziebart, Christina; Giangregorio, Lora M; Gibbs, Jenna C; Levine, Iris C; Tung, James; Laing, Andrew C

2017-06-14

A wide variety of accelerometer systems, with differing sensor characteristics, are used to detect impact loading during physical activities. The study examined the effects of system characteristics on measured peak impact loading during a variety of activities by comparing outputs from three separate accelerometer systems, and by assessing the influence of simulated reductions in operating range and sampling rate. Twelve healthy young adults performed seven tasks (vertical jump, box drop, heel drop, and bilateral single leg and lateral jumps) while simultaneously wearing three tri-axial accelerometers including a criterion standard laboratory-grade unit (Endevco 7267A) and two systems primarily used for activity-monitoring (ActiGraph GT3X+, GCDC X6-2mini). Peak acceleration (gmax) was compared across accelerometers, and errors resulting from down-sampling (from 640 to 100Hz) and range-limiting (to ±6g) the criterion standard output were characterized. The Actigraph activity-monitoring accelerometer underestimated gmax by an average of 30.2%; underestimation by the X6-2mini was not significant. Underestimation error was greater for tasks with greater impact magnitudes. gmax was underestimated when the criterion standard signal was down-sampled (by an average of 11%), range limited (by 11%), and by combined down-sampling and range-limiting (by 18%). These effects explained 89% of the variance in gmax error for the Actigraph system. This study illustrates that both the type and intensity of activity should be considered when selecting an accelerometer for characterizing impact events. In addition, caution may be warranted when comparing impact magnitudes from studies that use different accelerometers, and when comparing accelerometer outputs to osteogenic impact thresholds proposed in literature. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

A Hybrid Algorithm for Period Analysis from Multiband Data with Sparse and Irregular Sampling for Arbitrary Light-curve Shapes

Science.gov (United States)

Saha, Abhijit; Vivas, A. Katherina

2017-12-01

Ongoing and future surveys with repeat imaging in multiple bands are producing (or will produce) time-spaced measurements of brightness, resulting in the identification of large numbers of variable sources in the sky. A large fraction of these are periodic variables: compilations of these are of scientific interest for a variety of purposes. Unavoidably, the data sets from many such surveys not only have sparse sampling, but also have embedded frequencies in the observing cadence that beat against the natural periodicities of any object under investigation. Such limitations can make period determination ambiguous and uncertain. For multiband data sets with asynchronous measurements in multiple passbands, we wish to maximally use the information on periodicity in a manner that is agnostic of differences in the light-curve shapes across the different channels. Given large volumes of data, computational efficiency is also at a premium. This paper develops and presents a computationally economic method for determining periodicity that combines the results from two different classes of period-determination algorithms. The underlying principles are illustrated through examples. The effectiveness of this approach for combining asynchronously sampled measurements in multiple observables that share an underlying fundamental frequency is also demonstrated.

Coherent Phonon Dynamics in Short-Period InAs/GaSb Superlattices

OpenAIRE

Noe, G. T.; Haugan, H. J.; Brown, G. J.; Sanders, G. D.; Stanton, C. J.; Kono, J.

2011-01-01

We have performed ultrafast pump-probe spectroscopy studies on a series of InAs/GaSb-based short-period superlattice (SL) samples with periods ranging from 46 \\AA to 71 \\AA. We observe two types of oscillations in the differential reflectivity with fast ($\\sim$ 1- 2 ps) and slow ($\\sim$ 24 ps) periods. The period of the fast oscillations changes with the SL period and can be explained as coherent acoustic phonons generated from carriers photoexcited within the SL. This mode provides an accura...

Analytical Values for Mushroom Compost, Poultry Deep Litter and Poultry Slurry Samples over a 5 Year Period 1978-82

OpenAIRE

Gormley, T. R. (Thomas Ronan); Staunton, L.

1984-01-01

Data are presented on the analysis of mushroom compost, poultry deep litter and poultry slurry samples over the period 1978-82. There was no difference in the dry matter (DM) content of compost samples between years either at time of filling or spawning, with mean values of 32 and 29%, respectively. The DM values were highest in the April-September period. Nitrogen (N) values were not different on an annual or quarterly basis, with means of 2.21 and 1.99%, on a DM basis, at spawning and filli...

Reducing the sampling periods required in protocols for establishing ammonia emissions from pig fattening buildings using measurements and modelling

NARCIS (Netherlands)

Mosquera Losada, J.; Ogink, N.W.M.

2011-01-01

Ammonia (NH(3)) emission factors for animal housing systems in the Netherlands are based on measurements using standardised measurement protocols. Both the original Green Label (GL) protocol and the newly developed multi-site sampling protocol are based on year-round sampling periods. The objective

FPGA based computation of average neutron flux and e-folding period for start-up range of reactors

International Nuclear Information System (INIS)

Ram, Rajit; Borkar, S.P.; Dixit, M.Y.; Das, Debashis

2013-01-01

Pulse processing instrumentation channels used for reactor applications, play a vital role to ensure nuclear safety in startup range of reactor operation and also during fuel loading and first approach to criticality. These channels are intended for continuous run time computation of equivalent reactor core neutron flux and e-folding period. This paper focuses only the computational part of these instrumentation channels which is implemented in single FPGA using 32-bit floating point arithmetic engine. The computations of average count rate, log of average count rate, log rate and reactor period are done in VHDL using digital circuit realization approach. The computation of average count rate is done using fully adaptive window size moving average method, while Taylor series expansion for logarithms is implemented in FPGA to compute log of count rate, log rate and reactor e-folding period. This paper describes the block diagrams of digital logic realization in FPGA and advantage of fully adaptive window size moving average technique over conventional fixed size moving average technique for pulse processing of reactor instrumentations. (author)

Sensitivity of hepatitis C virus core antigen and antibody combination assays in a global panel of window period samples

Science.gov (United States)

Laperche, Syria; Nubling, C. Micha; Stramer, Susan L.; Brojer, Ewa; Grabarczyk, Piotr; Yoshizawa, Hiroshi; Kalibatas, Vytenis; El Elkyabi, Magdy; Moftah, Faten; Girault, Annie; van Drimmelen, Harry; Busch, Michael P.; Lelie, Nico

2016-01-01

BACKGROUND Hepatitis C virus (HCV) antigen and antibody combination assays have been launched as a cost-effective alternative to nucleic acid testing (NAT) for reducing the antibody-negative window period (WP). Later, a HCV antigen chemiluminescence immunoassay (CLIA) became available. STUDY DESIGN AND METHODS A panel composed of 337 HCV NAT–yield samples that were characterized for viral load (VL) and genotype was used to compare the sensitivity of two combination enzyme-linked immunosorbent assays (Monolisa, Bio-Rad; and Murex, formerly Abbott) and a HCV antigen CLIA (Abbott). Analytic sensitivity was compared with HCV RNA detection using Ultrio (Grifols) by testing serial dilutions of 10 genotype (gt)1 to gt4 samples. RESULTS HCV antigen CLIA detected 92.4% of samples, whereas Monolisa and Murex detected 38.3 and 47.5%, respectively. In the HCV RNA VL range of 105 to 107 IU/mL, Monolisa and Murex detected 38% to 56% of gt1, 85% to 78% of gt2, and 21% to 37% of gt3. The overall geometric mean 50% limit of detection (range) of Ultrio on gt1 to gt4 dilution series was 3.5 (1.2–7.7) copies/mL, compared to 3.3 × 106 (4.4 × 105-2.7 × 107), 3.4 × 106 (2.2 × 105–4.2 × 107), and 2728 (415–7243) copies/mL for Monolisa, Murex, and HCV antigen CLIA, respectively. CONCLUSION Analytical sensitivity of NAT was on average 1 million- and 780-fold higher than combination assays and HCV antigen CLIA, respectively. Relative sensitivities of combination assays differed for genotypes with Murex being more sensitive for gt1 and gt3 and Monolisa more sensitive for gt2. Although being less sensitive than NAT, combination assays could be considered in resource-limited settings since they detect 38% to 47% of seronegative WP donations. PMID:26013970

Systemic range shift lags among a pollinator species assemblage following rapid climate change

DEFF Research Database (Denmark)

Bedford, Felicity E.; Whittaker, Robert J.; Kerr, Jeremy T.

2012-01-01

Contemporary climate change is driving widespread geographical range shifts among many species. If species are tracking changing climate successfully, then leading populations should experience similar climatic conditions through time as new populations establish beyond historical range margins....... Here, we investigate geographical range shifts relative to changing climatic conditions among a particularly well-sampled assemblage of butterflies in Canada. We assembled observations of 81 species and measured their latitudinal displacement between two periods: 1960–1975 (a period of little climate...... change) and 1990–2005 (a period with large climate change). We find an unexpected trend for species’ northern borders to shift progressively less relative to increasing minimum winter temperatures in northern Canada. This study demonstrates a novel, systemic latitudinal gradient in lags among a large...

Broad-Range Bacterial Capture from Fluid-Samples: Implications for Amplification-Free Contamination Detection

Directory of Open Access Journals (Sweden)

Monika WEBER

2016-08-01

Full Text Available Fluid-Screen, Inc. presents a bacterial concentration and filtration method based on dielectrophoresis and alternating current kinetics. Dielectrophoresis has been previously shown to induce particle motion; however, bacterial capture efficiency and reproducibility have consistently been low, reducing its potential for practical applications. In this study, we introduce a novel, patent-pending electrode system optimized to simultaneously capture a wide range of bacterial species from a variety of aqueous solutions. Specifically, we show that the method of dielectrophoresis used induces responses in both characteristic Gram- negative Escherichia coli and Gram-positive Enterococcus faecalis bacteria, as well as with Bacillus subtilis and Aestuariimicrobium kwangyangense. We have adapted the electrode design to create a bacterial sample preparatio unit, termed the sample sorter, that is able to capture multiple bacterial species and release them simultaneously for bacterial concentration and exchange from complex matrices to defined buffer media. This technology can be used on its own or in conjunction with standard bacterial detection methods such as mass spectroscopy. The Fluid-Screen product will dramatically improve testing and identification of bacterial contaminants in various industrial settings by eliminating the need for amplification of samples and by reducing the time to identification.

Studies on radioimmunoassay diagnosis of cow pregnancy at an early period by milk sample communication

International Nuclear Information System (INIS)

Wu Meiwen

1986-01-01

Cow pregancy was diagnosed at an early period by milk sample communication and radioimmunoassay (RIA). Liquid milk samples were converted into solid forms on filter paper and mailed to the laboratory from appointed locations, and concentrations of progesterone in milk samples were then determined by RIA method. Milks were sampled 19 and 23 days after mating. Criterion used for the judgement of cow pregnancy was as follows: When the progesterone content in milk was 5 ng/ml or less, the cow was not pregnant; when progesterone content was between 5-11 ng/ml, it was doubtful; when progesterone content was 11 ng/ml or more, it was pregnant. According to this criterion, among 215 cows, 131 were pregnant, 73 were not pregnant, and 11 were doubtful. The results were further checked by palpation 3 months after inseminations. The unpregnancy and pregnancy accuracies were 97.6% and 89.2%, respectively. Forther milk samples were collected on 44 days for above cows that had been diagnosed on 19 and 23 days showing pregnancy to diagnose embryo forming. Among 91 cows, 74 had embryo. 7 had none, and the other 10 were doubtful. The embryo and unembryo accuracies were 94.6% and 100% respectively checking by palpation 3 months after inseminations

Radioactivity measurements of soil samples in the Region Vranje (Bratoselce Village) for the period 2001-2004

International Nuclear Information System (INIS)

Eremic-savkovic, M.; Pantelic, G.; Tanaskovic, I.; Vuletic, V.; Javorina, L.

2006-01-01

Systematic examination of radioactive contamination of soil samples was established at the Institute for Occupational and Radiological Health. With the bombing of our country (Spring 1999) the monitoring of radioactivity has changed. We also measured the activities of uranium and it descendants. This paper presents the results of radioactivity monitoring of the soil in small area 700 m near village Bratoselce in region Vranje during the period 2001 - 2004. From 2001 to 2004, we collected different samples from this fenced area as well as outside this area assuming not to be contaminated, before, during and after decontamination. Some soil samples were made as a mix of small samples from a large area of location. Other samples were taken at the points formerly designated as contaminated or from shell-craters seen on the fenced area surface. All samples were analyzed by gamma spectrometry and measurements of alpha and beta activity. On the basis of measurements of soil activities, analysis of 238 U and 235 U, as well as in comparison with natural activity ratio being 21.4, it may be concluded that depleted uranium contamination was present both in the fenced area and outside it, because this ratio in the samples of soil was found to be 34 to 73. Natural activity in soil samples was slightly higher in relation to mean soil activity in Serbia. (authors)

Extraordinary tunable dynamic range of electrochemical aptasensor for accurate detection of ochratoxin A in food samples

Directory of Open Access Journals (Sweden)

Lin Cheng

2017-06-01

Full Text Available We report the design of a sensitive, electrochemical aptasensor for detection of ochratoxin A (OTA with an extraordinary tunable dynamic sensing range. This electrochemical aptasensor is constructed based on the target induced aptamer-folding detection mechanism and the recognition between OTA and its aptamers results in the conformational change of the aptamer probe and thus signal changes for measurement. The dynamic sensing range of the electrochemical aptasensor is successfully tuned by introduction of free assistant aptamer probes in the sensing system. Our electrochemical aptasensor shows an extraordinary dynamic sensing range of 11-order magnitude of OTA concentration from 10−8 to 102 ng/g. Of great significance, the signal response in all OTA concentration ranges is at the same current scale, demonstrating that our sensing protocol in this research could be applied for accurate detections of OTA in a broad range without using any complicated treatment of signal amplification. Finally, OTA spiked red wine and maize samples in different dynamic sensing ranges are determined with the electrochemical aptasensor under optimized sensing conditions. This tuning strategy of dynamic sensing range may offer a promising platform for electrochemical aptasensor optimizations in practical applications.

Prevalence and sources of Campylobacter spp. contamination in free-range broiler production in the southern part of Belgium

Directory of Open Access Journals (Sweden)

Vandeplas, S.

2010-01-01

Full Text Available A one year epidemiological study was carried out between February 2005 and February 2006 in the southern part of Belgium to assess the Campylobacter prevalence in free-range broiler production. Three successive broiler flocks from six Belgian farms were investigated for the presence of Campylobacter spp. during the rearing period. Each flock was visited four times, before and after the outdoor rearing period. During each visit, samples were taken in the broiler house (litter, cecal droppings, water-lines, feed, anteroom as well as from the outer rearing environment (open-air range. The Campylobacter detection in all samples was carried out according to the ISO 10272 standard. Identification was based on colonial morphology, microscopic examination, and biochemical tests. PCR multiplex was used for genetic confirmation. Campylobacter jejuni was the main species isolated from all contaminated samples. Overall, mixed infections C. jejuni / Campylobacter coli represented 40.6%, while C. jejuni and C. coli represented 46.9% and 12.5% of chicken samples respectively. A 100% flock contamination was observed in the 6 farms during the summer-autumn period, whereas only 66.7% and 33.3% of the flocks became Campylobacter-positive in spring and winter respectively, at the end of the rearing period. Half of contaminated flocks were infected before chickens have access to the open-air range. Environmental samples, especially the open-air range soil, were found to be Campylobacter-positive before flock infection. The other potential sources of contamination were delivery tray, anteroom floor and water-lines. Other animal productions like cattle on the farm, no applied rodent control, no cleaning and disinfection of water-lines between flocks, no detergent used for cleaning and thinning were recorded as risk factors. In conclusion, the contact with the environment, particularly the access to an open-air range, appeared to be the major way of Campylobacter

Systematic Sampling and Cluster Sampling of Packet Delays

OpenAIRE

Lindh, Thomas

2006-01-01

Based on experiences of a traffic flow performance meter this papersuggests and evaluates cluster sampling and systematic sampling as methods toestimate average packet delays. Systematic sampling facilitates for exampletime analysis, frequency analysis and jitter measurements. Cluster samplingwith repeated trains of periodically spaced sampling units separated by randomstarting periods, and systematic sampling are evaluated with respect to accuracyand precision. Packet delay traces have been ...

Are symptom features of depression during pregnancy, the postpartum period and outside the peripartum period distinct? Results from a nationally representative sample using item response theory (IRT).

Science.gov (United States)

Hoertel, Nicolas; López, Saioa; Peyre, Hugo; Wall, Melanie M; González-Pinto, Ana; Limosin, Frédéric; Blanco, Carlos

2015-02-01

Whether there are systematic differences in depression symptom expression during pregnancy, the postpartum period and outside these periods (i.e., outside the peripartum period) remains debated. The aim of this study was to use methods based on item response theory (IRT) to examine, after equating for depression severity, differences in the likelihood of reporting DSM-IV symptoms of major depressive episode (MDE) in women of childbearing age (i.e., aged 18-50) during pregnancy, the postpartum period and outside the peripartum period. We conducted these analyses using a large, nationally representative sample of women of childbearing age from the United States (n = 11,256) who participated in the second wave of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). The overall 12-month prevalence of all depressive criteria (except for worthlessness/guilt) was significantly lower in pregnant women than in women of childbearing age outside the peripartum period, whereas the prevalence of all symptoms (except for "psychomotor symptoms") was not significantly different between the postpartum and the nonperipartum group. There were no clinically significant differences in the endorsement rates of symptoms of MDE by pregnancy status when equating for levels of depression severity. This study suggests that the clinical presentation of depressive symptoms in women of childbearing age does not differ during pregnancy, the postpartum period and outside the peripartum period. These findings do not provide psychometric support for the inclusion of the peripartum onset specifier for major depressive disorder in the DSM-5. © 2014 Wiley Periodicals, Inc.

Evaluation of personal air sampling pumps

International Nuclear Information System (INIS)

Ritter, P.D.; Novick, V.J.; Alvarez, J.L.; Huntsman, B.L.

1987-01-01

Personal air samplers are used to more conveniently obtain breathing zone samples from individuals over periods of several hours. Personal air sampling pumps must meet minimum performance levels under all working conditions to be suitable for use in radiation protection programs. In addition, the pumps should be simple to operate and as comfortable to wear as possible. Ten models of personal air sampling pumps were tested to evaluate their mechanical performance and physical characteristics. The pumps varied over a wide range in basic performance and operating features. Some of the pumps were found to have adequate performance for use in health physics air sampling applications. 3 references, 2 figures, 5 tables

Changes According to Incubation Periods in Some Microbiological Characteristics at Soil Samples of Some Soil Series from the Gelemen Agricultural Administration

OpenAIRE

KARA, Emine Erman

1998-01-01

Changes according to incubation periods in some microbiological characteristics at soil samples of soil series from Gelemen Agricultural Administraction were investigated in this study. The results show that bacteria, actinomycet had values in the first periods of incubation (30ºC and field capacity) and in the following periods increased. However, fungus population changed depending upon series properties and reached maximum values 24th and 32th days after the beginning of incubation. During...

Automated combustion accelerator mass spectrometry for the analysis of biomedical samples in the low attomole range.

Science.gov (United States)

van Duijn, Esther; Sandman, Hugo; Grossouw, Dimitri; Mocking, Johannes A J; Coulier, Leon; Vaes, Wouter H J

2014-08-05

The increasing role of accelerator mass spectrometry (AMS) in biomedical research necessitates modernization of the traditional sample handling process. AMS was originally developed and used for carbon dating, therefore focusing on a very high precision but with a comparably low sample throughput. Here, we describe the combination of automated sample combustion with an elemental analyzer (EA) online coupled to an AMS via a dedicated interface. This setup allows direct radiocarbon measurements for over 70 samples daily by AMS. No sample processing is required apart from the pipetting of the sample into a tin foil cup, which is placed in the carousel of the EA. In our system, up to 200 AMS analyses are performed automatically without the need for manual interventions. We present results on the direct total (14)C count measurements in <2 μL human plasma samples. The method shows linearity over a range of 0.65-821 mBq/mL, with a lower limit of quantification of 0.65 mBq/mL (corresponding to 0.67 amol for acetaminophen). At these extremely low levels of activity, it becomes important to quantify plasma specific carbon percentages. This carbon percentage is automatically generated upon combustion of a sample on the EA. Apparent advantages of the present approach include complete omission of sample preparation (reduced hands-on time) and fully automated sample analysis. These improvements clearly stimulate the standard incorporation of microtracer research in the drug development process. In combination with the particularly low sample volumes required and extreme sensitivity, AMS strongly improves its position as a bioanalysis method.

Photolysis of Periodate and Periodic Acid in Aqueous Solution

DEFF Research Database (Denmark)

Sehested, Knud; Kläning, U. K.

1978-01-01

The photochemistry of periodate and periodic acid in aqueous solution was studied (i) by quantum yield measurements at low light intensity (ii) by flash photolysis, and (iii) by photolysis of glassy samples at 77 K. The photochemical studies were supplemented with pulse radiolysis studies...... of aqueous periodate solutions and with kinetic studies using stopped-flow technique. In strongly alkaline solution the photodecomposition of periodate proceeds via formation of O– and IVI. At pH solution O3 P is formed in a small...

Evaluation of FASP, SP3, and iST Protocols for Proteomic Sample Preparation in the Low Microgram Range.

Science.gov (United States)

Sielaff, Malte; Kuharev, Jörg; Bohn, Toszka; Hahlbrock, Jennifer; Bopp, Tobias; Tenzer, Stefan; Distler, Ute

2017-11-03

Efficient and reproducible sample preparation is a prerequisite for any robust and sensitive quantitative bottom-up proteomics workflow. Here, we performed an independent comparison between single-pot solid-phase-enhanced sample preparation (SP3), filter-aided sample preparation (FASP), and a commercial kit based on the in-StageTip (iST) method. We assessed their performance for the processing of proteomic samples in the low μg range using varying amounts of HeLa cell lysate (1-20 μg of total protein). All three workflows showed similar performances for 20 μg of starting material. When handling sample sizes below 10 μg, the number of identified proteins and peptides as well as the quantitative reproducibility and precision drastically dropped in case of FASP. In contrast, SP3 and iST provided high proteome coverage even in the low μg range. Even when digesting 1 μg of starting material, both methods still enabled the identification of over 3000 proteins and between 25 000 and 30 000 peptides. On average, the quantitative reproducibility between experimental replicates was slightly higher in case of SP3 (R 2 = 0.97 (SP3); R 2 = 0.93 (iST)). Applying SP3 toward the characterization of the proteome of FACS-sorted tumor-associated macrophages in the B16 tumor model enabled the quantification of 2965 proteins and revealed a "mixed" M1/M2 phenotype.

Earth Noise in the 20- to 100-Second Period Range

Science.gov (United States)

1975-09-09

instruments were incapable of following fluctuations of shorter periods.) Gretener (1967) obtained similar results. Both of these workers...found indica- tions that the convection eddies believed to exist were comparable to the hole diameter in vertical extent. Both Gretener (1967...Heat flow in Western Canada: geoph. J., v. 6, p. 245-261. Gretener , P. E., 1967, On the thermal instability of large diameter wells: geophysics, J32

Imaging using long range dipolar field effects

International Nuclear Information System (INIS)

Gutteridge, Sarah

2002-01-01

The work in this thesis has been undertaken by the author, except where indicated in reference, within the Magnetic Resonance Centre, at the University of Nottingham during the period from October 1998 to March 2001. This thesis details the different characteristics of the long range dipolar field and its application to magnetic resonance imaging. The long range dipolar field is usually neglected in nuclear magnetic resonance experiments, as molecular tumbling decouples its effect at short distances. However, in highly polarised samples residual long range components have a significant effect on the evolution of the magnetisation, giving rise to multiple spin echoes and unexpected quantum coherences. Three applications utilising these dipolar field effects are documented in this thesis. The first demonstrates the spatial sensitivity of the signal generated via dipolar field effects in structured liquid state samples. The second utilises the signal produced by the dipolar field to create proton spin density maps. These maps directly yield an absolute value for the water content of the sample that is unaffected by relaxation and any RF inhomogeneity or calibration errors in the radio frequency pulses applied. It has also been suggested that the signal generated by dipolar field effects may provide novel contrast in functional magnetic resonance imaging. In the third application, the effects of microscopic susceptibility variation on the signal are studied and the relaxation rate of the signal is compared to that of a conventional spin echo. (author)

Compressive laser ranging.

Science.gov (United States)

Babbitt, Wm Randall; Barber, Zeb W; Renner, Christoffer

2011-12-15

Compressive sampling has been previously proposed as a technique for sampling radar returns and determining sparse range profiles with a reduced number of measurements compared to conventional techniques. By employing modulation on both transmission and reception, compressive sensing in ranging is extended to the direct measurement of range profiles without intermediate measurement of the return waveform. This compressive ranging approach enables the use of pseudorandom binary transmit waveforms and return modulation, along with low-bandwidth optical detectors to yield high-resolution ranging information. A proof-of-concept experiment is presented. With currently available compact, off-the-shelf electronics and photonics, such as high data rate binary pattern generators and high-bandwidth digital optical modulators, compressive laser ranging can readily achieve subcentimeter resolution in a compact, lightweight package.

Outdoor stocking density in free-range laying hens: radio-frequency identification of impacts on range use.

Science.gov (United States)

Campbell, D L M; Hinch, G N; Dyall, T R; Warin, L; Little, B A; Lee, C

2017-01-01

The number and size of free-range laying hen (Gallus gallus domesticus) production systems are increasing within Australia in response to consumer demand for perceived improvement in hen welfare. However, variation in outdoor stocking density has generated consumer dissatisfaction leading to the development of a national information standard on free-range egg labelling by the Australian Consumer Affairs Ministers. The current Australian Model Code of Practice for Domestic Poultry states a guideline of 1500 hens/ha, but no maximum density is set. Radio-frequency identification (RFID) tracking technology was used to measure daily range usage by individual ISA Brown hens housed in six small flocks (150 hens/flock - 50% of hens tagged), each with access to one of three outdoor stocking density treatments (two replicates per treatment: 2000, 10 000, 20 000 hens/ha), from 22 to 26, 27 to 31 and 32 to 36 weeks of age. There was some variation in range usage across the sampling periods and by weeks 32 to 36 individual hens from the lowest stocking density on average used the range for longer each day (Prange with 2% of tagged hens in each treatment never venturing outdoors and a large proportion that accessed the range daily (2000 hens/ha: 80.5%; 10 000 hens/ha: 66.5%; 20 000 hens/ha: 71.4%). On average, 38% to 48% of hens were seen on the range simultaneously and used all available areas of all ranges. These results of experimental-sized flocks have implications for determining optimal outdoor stocking densities for commercial free-range laying hens but further research would be needed to determine the effects of increased range usage on hen welfare.

Forward Period Analysis Method of the Periodic Hamiltonian System.

Directory of Open Access Journals (Sweden)

Pengfei Wang

Full Text Available Using the forward period analysis (FPA, we obtain the period of a Morse oscillator and mathematical pendulum system, with the accuracy of 100 significant digits. From these results, the long-term [0, 1060] (time unit solutions, ranging from the Planck time to the age of the universe, are computed reliably and quickly with a parallel multiple-precision Taylor series (PMT scheme. The application of FPA to periodic systems can greatly reduce the computation time of long-term reliable simulations. This scheme provides an efficient way to generate reference solutions, against which long-term simulations using other schemes can be tested.

Short-range order in alloys of nickel with the elements of group VIII of the periodic table

International Nuclear Information System (INIS)

Khwaja, F.A.

1981-08-01

Experimental measurements of the diffuse X-ray scattering intensity were performed on alloys of Ni with Rh and Os. The atomic short-range order (SRO) parameters αsub(i) and the size-effect parameters βsub(i) were calculated from these measurements. It is established that SRO and size-effect exist in Ni-Rh and Ni-Os alloys analogously as in a few other alloys of Ni with the elements of group VIII of the periodic table. The experimental data was interpreted theoretically by calculating the interaction energies from the pseudo-potentials and the effective valencies of the individual components of the systems studied. It was found that theoretically calculated values of the interaction energies for these alloys are inconsistent with the experimentally determined sign of the SRO parameter. (author)

Long-range dependence in returns and volatility of global gold market amid financial crises

Science.gov (United States)

Omane-Adjepong, Maurice; Boako, Gideon

2017-04-01

Using sampled historical daily gold market data from 07-03-1985 to 06-01-2015, and building on a related work by Bentes (2016), this paper examines the presence of long-range dependence (LRD) in the world's gold market returns and volatility, accounting for structural breaks. The sampled gold market data was divided into subsamples based on four global crises: the September 1992 collapse of the European Exchange Rate Mechanism (ERM), the Asian financial crisis of mid-1997, the Subprime meltdown of 2007, and the recent European sovereign debt crisis, which hit the world's market with varying effects. LRD test was carried-out on the full-sample and subsample periods using three semiparametric methods-before and after adjusting for structural breaks. The results show insignificant evidence of LRD in gold returns. However, very diminutive evidence is found for periods characterized by financial/economic shocks, with no significant detections for post-shock periods. Collectively, this is indicative that the gold market is less speculative, and hence could be somehow less risky for hedging and portfolio diversification.

k0-INAA for APM samples collected in period of June 2004 - March 2005 and some marine certified reference materials

International Nuclear Information System (INIS)

Dung, Ho Manh; Vu, Cao Dong; Y, Truong; Sy, Nguyen Thi

2006-01-01

The airborne particulate matter (APM) samples have been collected in 2004 using two types of polycarbonate membrane filter PM 2.5 and PM 2.5-10 at two sites of industrial (Ho Chi Mihn City) and rural (Dateh) regions in south of Vietnam. Three marine certified reference materials have been selected to establish a k0-NAA procedure for marine samples. The concentration of trace multi-element in the samples has been determined by the k 0 -INAA procedure using K o -DALAT software developed in Dalat NRI. About 28 elements in 224 APM samples collected at two areas of Dateh and HCMC of Vietnam in period from June, 2004 to March, 2005 were presented in report. The statistical analysis was applied to the data set to investigate the pollution source at sampling sites. The results proved that the k 0 -NAA on the Dalat research reactor is a reliable and effective analytical technique for characterization of trace multi-element in APM and marine samples for air and marine environmental pollution study in Vietnam. (author)

Free-ranging farm cats: home range size and predation on a livestock unit in Northwest Georgia.

Science.gov (United States)

Kitts-Morgan, Susanna E; Caires, Kyle C; Bohannon, Lisa A; Parsons, Elizabeth I; Hilburn, Katharine A

2015-01-01

This study's objective was to determine seasonal and diurnal vs. nocturnal home range size, as well as predation for free-ranging farm cats at a livestock unit in Northwest Georgia. Seven adult cats were tracked with attached GPS units for up to two weeks for one spring and two summer seasons from May 2010 through August 2011. Three and five cats were tracked for up to two weeks during the fall and winter seasons, respectively. Feline scat was collected during this entire period. Cats were fed a commercial cat food daily. There was no seasonal effect (P > 0.05) on overall (95% KDE and 90% KDE) or core home range size (50% KDE). Male cats tended (P = 0.08) to have larger diurnal and nocturnal core home ranges (1.09 ha) compared to female cats (0.64 ha). Reproductively intact cats (n = 2) had larger (P ranges as compared to altered cats. Feline scat processing separated scat into prey parts, and of the 210 feline scats collected during the study, 75.24% contained hair. Of these 158 scat samples, 86 contained non-cat hair and 72 contained only cat hair. Other prey components included fragments of bone in 21.43% of scat and teeth in 12.86% of scat. Teeth were used to identify mammalian prey hunted by these cats, of which the Hispid cotton rat (Sigmodon hispidus) was the primary rodent. Other targeted mammals were Peromyscus sp., Sylvilagus sp. and Microtus sp. Invertebrates and birds were less important as prey, but all mammalian prey identified in this study consisted of native animals. While the free-ranging farm cats in this study did not adjust their home range seasonally, sex and reproductive status did increase diurnal and nocturnal home range size. Ultimately, larger home ranges of free-ranging cats could negatively impact native wildlife.

Ensemble Sampling

OpenAIRE

Lu, Xiuyuan; Van Roy, Benjamin

2017-01-01

Thompson sampling has emerged as an effective heuristic for a broad range of online decision problems. In its basic form, the algorithm requires computing and sampling from a posterior distribution over models, which is tractable only for simple special cases. This paper develops ensemble sampling, which aims to approximate Thompson sampling while maintaining tractability even in the face of complex models such as neural networks. Ensemble sampling dramatically expands on the range of applica...

Wide-range bipolar pulse conductance instrument employing current and voltage modes with sampled or integrated signal acquisition

Energy Technology Data Exchange (ETDEWEB)

Calhoun, R K; Holler, F J [Kentucky Univ., Lexington, KY (United States). Dept. of Chemistry; Geiger, jr, R F; Nieman, T A [Illinois Univ., Urbana, IL (United States). Dept. of Chemistry; Caserta, K J [Procter and Gamble Co., Cincinnati, OH (United States)

1991-11-05

An instrument for measuring solution conductance using the bipolar pulse technique is described. The instrument is capable of measuring conductances in the range of 5x10{sup -9}-10{Omega}{sup -1} with 1% accuracy or better in as little as 32 {mu}s. Accuracy of 0.001-0.01% is achievable over the range 1x10{sup -6}-1{Omega}{sup -1}. Circuitry and software are described that allow the instrument to adjust automatically the pulse height, pulse duration, excitation mode (current or voltage pulse) and data acquisition mode (sampled or integrated) to acquire data of optimum accuracy and precision. The urease-catalyzed decomposition of urea is used to illustrate the versality of the instrument, and other applications are cited. (author). 60 refs.; 7 figs.; 2 tabs.

Free-Ranging Farm Cats: Home Range Size and Predation on a Livestock Unit In Northwest Georgia

Science.gov (United States)

Kitts-Morgan, Susanna E.; Caires, Kyle C.; Bohannon, Lisa A.; Parsons, Elizabeth I.; Hilburn, Katharine A.

2015-01-01

This study’s objective was to determine seasonal and diurnal vs. nocturnal home range size, as well as predation for free-ranging farm cats at a livestock unit in Northwest Georgia. Seven adult cats were tracked with attached GPS units for up to two weeks for one spring and two summer seasons from May 2010 through August 2011. Three and five cats were tracked for up to two weeks during the fall and winter seasons, respectively. Feline scat was collected during this entire period. Cats were fed a commercial cat food daily. There was no seasonal effect (P > 0.05) on overall (95% KDE and 90% KDE) or core home range size (50% KDE). Male cats tended (P = 0.08) to have larger diurnal and nocturnal core home ranges (1.09 ha) compared to female cats (0.64 ha). Reproductively intact cats (n = 2) had larger (P cats. Feline scat processing separated scat into prey parts, and of the 210 feline scats collected during the study, 75.24% contained hair. Of these 158 scat samples, 86 contained non-cat hair and 72 contained only cat hair. Other prey components included fragments of bone in 21.43% of scat and teeth in 12.86% of scat. Teeth were used to identify mammalian prey hunted by these cats, of which the Hispid cotton rat (Sigmodon hispidus) was the primary rodent. Other targeted mammals were Peromyscus sp., Sylvilagus sp. and Microtus sp. Invertebrates and birds were less important as prey, but all mammalian prey identified in this study consisted of native animals. While the free-ranging farm cats in this study did not adjust their home range seasonally, sex and reproductive status did increase diurnal and nocturnal home range size. Ultimately, larger home ranges of free-ranging cats could negatively impact native wildlife. PMID:25894078

Serosurvey of viral infections in free-ranging Namibian cheetahs (Acinonyx jubatus).

Science.gov (United States)

Munson, Linda; Marker, Laurie; Dubovi, Edward; Spencer, Jennifer A; Evermann, James F; O'Brien, Stephen J

2004-01-01

Cheetahs (Acinonyx jubatus) in captivity have unusually high morbidity and mortality from infectious diseases, a trait that could be an outcome of population homogeneity or the immunomodulating effects of chronic stress. Free-ranging Namibian cheetahs share ancestry with captive cheetahs, but their susceptibility to infectious diseases has not been investigated. The largest remaining population of free-ranging cheetahs resides on Namibian farmlands, where they share habitat with domestic dogs and cats known to carry viruses that affect cheetah health. To assess the extent to which free-ranging cheetahs are exposed to feline and canine viruses, sera from 81 free-ranging cheetahs sampled between 1992 and 1998 were evaluated for antibodies against canine distemper virus (CDV), feline coronavirus (feline infectious peritonitis virus; FCoV/ FIPV), feline herpesvirus 1 (FHV1), feline panleukopenia virus (FPV), feline immunodeficiency virus (FIV), and feline calicivirus (FCV) and for feline leukemia virus (FeLV) antigens. Antibodies against CDV, FCoV/FIPV, FHV1, FPV, and FCV were detected in 24, 29, 12, 48, and 65% of the free-ranging population, respectively, although no evidence of viral disease was present in any animal at the time of sample collection. Neither FIV antibodies nor FeLV antigens were present in any free-ranging cheetah tested. Temporal variation in FCoV/FIPV seroprevalence during the study period suggested that this virus is not endemic in the free-ranging population. Antibodies against CDV were detected in cheetahs of all ages sampled between 1995 and 1998, suggesting the occurrence of an epidemic in Namibia during the time when CDV swept through other parts of sub-Saharan Africa. This evidence in free-ranging Namibian cheetahs of exposure to viruses that cause severe disease in captive cheetahs should direct future guidelines for translocations, including quarantine of seropositive cheetahs and preventing contact between cheetahs and domestic pets.

HATS-43b, HATS-44b, HATS-45b, and HATS-46b: Four Short-period Transiting Giant Planets in the Neptune–Jupiter Mass Range

Science.gov (United States)

Brahm, R.; Hartman, J. D.; Jordán, A.; Bakos, G. Á.; Espinoza, N.; Rabus, M.; Bhatti, W.; Penev, K.; Sarkis, P.; Suc, V.; Csubry, Z.; Bayliss, D.; Bento, J.; Zhou, G.; Mancini, L.; Henning, T.; Ciceri, S.; de Val-Borro, M.; Shectman, S.; Crane, J. D.; Arriagada, P.; Butler, P.; Teske, J.; Thompson, I.; Osip, D.; Díaz, M.; Schmidt, B.; Lázár, J.; Papp, I.; Sári, P.

2018-03-01

We report the discovery of four short-period extrasolar planets transiting moderately bright stars from photometric measurements of the HATSouth network coupled to additional spectroscopic and photometric follow-up observations. While the planet masses range from 0.26 to 0.90 {M}{{J}}, the radii are all approximately a Jupiter radii, resulting in a wide range of bulk densities. The orbital period of the planets ranges from 2.7 days to 4.7 days, with HATS-43b having an orbit that appears to be marginally non-circular (e = 0.173 ± 0.089). HATS-44 is notable for having a high metallicity ([{Fe}/{{H}}] = 0.320 ± 0.071). The host stars spectral types range from late F to early K, and all of them are moderately bright (13.3 Carnegie Institute is operated by PU in conjunction with PUC, the station at the High Energy Spectroscopic Survey (H.E.S.S.) site is operated in conjunction with MPIA, and the station at Siding Spring Observatory (SSO) is operated jointly with ANU. This paper includes data gathered with the MPG 2.2 m and ESO 3.6 m telescopes at the ESO Observatory in La Silla. This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile.

Effects of sample injection amount and time-of-flight mass spectrometric detection dynamic range on metabolome analysis by high-performance chemical isotope labeling LC-MS.

Science.gov (United States)

Zhou, Ruokun; Li, Liang

2015-04-06

The effect of sample injection amount on metabolome analysis in a chemical isotope labeling (CIL) liquid chromatography-mass spectrometry (LC-MS) platform was investigated. The performance of time-of-flight (TOF) mass spectrometers with and without a high-dynamic-range (HD) detection system was compared in the analysis of (12)C2/(13)C2-dansyl labeled human urine samples. An average of 1635 ± 21 (n = 3) peak pairs or putative metabolites was detected using the HD-TOF-MS, compared to 1429 ± 37 peak pairs from a conventional or non-HD TOF-MS. In both instruments, signal saturation was observed. However, in the HD-TOF-MS, signal saturation was mainly caused by the ionization process, while in the non-HD TOF-MS, it was caused by the detection process. To extend the MS detection range in the non-HD TOF-MS, an automated switching from using (12)C to (13)C-natural abundance peaks for peak ratio calculation when the (12)C peaks are saturated has been implemented in IsoMS, a software tool for processing CIL LC-MS data. This work illustrates that injecting an optimal sample amount is important to maximize the metabolome coverage while avoiding the sample carryover problem often associated with over-injection. A TOF mass spectrometer with an enhanced detection dynamic range can also significantly increase the number of peak pairs detected. In chemical isotope labeling (CIL) LC-MS, relative metabolite quantification is done by measuring the peak ratio of a (13)C2-/(12)C2-labeled peak pair for a given metabolite present in two comparative samples. The dynamic range of peak ratio measurement does not need to be very large, as only subtle changes of metabolite concentrations are encountered in most metabolomic studies where relative metabolome quantification of different groups of samples is performed. However, the absolute concentrations of different metabolites can be very different, requiring a technique to provide a wide detection dynamic range to allow the detection of as

Demonstration/Validation of Incremental Sampling at Two Diverse Military Ranges and Development of an Incremental Sampling Tool

Science.gov (United States)

2010-06-01

Sampling (MIS)? • Technique of combining many increments of soil from a number of points within exposure area • Developed by Enviro Stat (Trademarked...Demonstrating a reliable soil sampling strategy to accurately characterize contaminant concentrations in spatially extreme and heterogeneous...into a set of decision (exposure) units • One or several discrete or small- scale composite soil samples collected to represent each decision unit

A study on the ranges of low energy ions in biological samples and its mechanism of biological effects

International Nuclear Information System (INIS)

Lu Ting; Xie Liqing; Li Junping; Xia Ji

1993-01-01

The seeds of wheat and bean are irradiated by iron ion beam with energy 100 keV. The RBS spectra of the samples are observed and the ranges and distributions of the iron ions in the wheat and bean are calculated theoretically by means of Monte Carlo method. The results of theory and experiment are compared and the mechanism of biological effects induced by ion is discussed

Simulation of range imaging-based estimation of respiratory lung motion. Influence of noise, signal dimensionality and sampling patterns.

Science.gov (United States)

Wilms, M; Werner, R; Blendowski, M; Ortmüller, J; Handels, H

2014-01-01

A major problem associated with the irradiation of thoracic and abdominal tumors is respiratory motion. In clinical practice, motion compensation approaches are frequently steered by low-dimensional breathing signals (e.g., spirometry) and patient-specific correspondence models, which are used to estimate the sought internal motion given a signal measurement. Recently, the use of multidimensional signals derived from range images of the moving skin surface has been proposed to better account for complex motion patterns. In this work, a simulation study is carried out to investigate the motion estimation accuracy of such multidimensional signals and the influence of noise, the signal dimensionality, and different sampling patterns (points, lines, regions). A diffeomorphic correspondence modeling framework is employed to relate multidimensional breathing signals derived from simulated range images to internal motion patterns represented by diffeomorphic non-linear transformations. Furthermore, an automatic approach for the selection of optimal signal combinations/patterns within this framework is presented. This simulation study focuses on lung motion estimation and is based on 28 4D CT data sets. The results show that the use of multidimensional signals instead of one-dimensional signals significantly improves the motion estimation accuracy, which is, however, highly affected by noise. Only small differences exist between different multidimensional sampling patterns (lines and regions). Automatically determined optimal combinations of points and lines do not lead to accuracy improvements compared to results obtained by using all points or lines. Our results show the potential of multidimensional breathing signals derived from range images for the model-based estimation of respiratory motion in radiation therapy.

Direct quantification of PM2.5 fossil and biomass carbon within the Northern Front Range Air Quality Study's domain

International Nuclear Information System (INIS)

Klinedinst, D.B.; Currie, L.A.

1999-01-01

Radiocarbon ( 14 C) analyses of PM 2.5 (particulate matter with an aerodynamic diameter of 2.5 microm or less) of both ambient and source samples from the Northern Front Range Air Quality Study (NFRAQS) in Colorado were performed. The 14 C analyses were undertaken to provide direct fossil vs modern (biomass) carbon source discrimination data for a subset of summer and winter 1996--1997 samples collected within the Denver metropolitan area. Samples were prepared for 14 C accelerator mass spectrometry measurements using techniques specially developed for small samples, i.e., lt100 μg C. For the days and sampling periods analyzed the median and interquartile range of the winter blank corrected fraction of modern carbon was 23% (16--34%) at Welby and 27% (25--37%) at Brighton. The summer samples exhibited a more mixed signature with a median and interquartile range of 47% (9--70%). Source samples yielded 14 C signatures consistent with expectation. The authors conclude fossil-derived sources contribute substantially in both seasons and at both locations; however, the biomass carbon component dominates episodically in the summer

On the observed excess of retrograde orbits among long-period comets

International Nuclear Information System (INIS)

Fernandez, J.A.

1981-01-01

The distribution of orbital inclinations of the observed long-period comets is analysed. An excess of retrograde orbits is found which increases with the perihelion distance, except for the range 1.1 10 3 A U) has the same behaviour as the total sample. It is thus suggested that the excess of retrograde orbits among long-period comets is related to an already existent excess among the incoming new comets (i.e. comets driven into the planetary region by stellar perturbations). Using theoretical considerations and a numerical model it is proposed that an important fraction of the so-called new comets are actually repeating passages through the planetary region. Nearly a half of the new comets with q > 2 A U may be repeating passages. An important consequence of the presence of comets repeating passages among the new ones is the production of an excess of retrograde orbits in the whole sample. (author)

Choice of Sample Split in Out-of-Sample Forecast Evaluation

DEFF Research Database (Denmark)

Hansen, Peter Reinhard; Timmermann, Allan

, while conversely the power of forecast evaluation tests is strongest with long out-of-sample periods. To deal with size distortions, we propose a test statistic that is robust to the effect of considering multiple sample split points. Empirical applications to predictabil- ity of stock returns......Out-of-sample tests of forecast performance depend on how a given data set is split into estimation and evaluation periods, yet no guidance exists on how to choose the split point. Empirical forecast evaluation results can therefore be difficult to interpret, particularly when several values...... and inflation demonstrate that out-of-sample forecast evaluation results can critically depend on how the sample split is determined....

PERIODIC AND APERIODIC VARIABILITY IN THE MOLECULAR CLOUD ρ OPHIUCHUS

International Nuclear Information System (INIS)

Parks, J. Robert; Plavchan, Peter; Gee, Alan H.; White, Russel J.

2014-01-01

Presented are the results of a near-IR photometric survey of 1678 stars in the direction of the ρ Ophiuchus (ρ Oph) star forming region using data from the 2MASS Calibration Database. For each target in this sample, up to 1584 individual J-, H-, and K s -band photometric measurements with a cadence of ∼1 day are obtained over three observing seasons spanning ∼2.5 yr; it is the most intensive survey of stars in this region to date. This survey identifies 101 variable stars with ΔK s -band amplitudes from 0.044 to 2.31 mag and Δ(J – K s ) color amplitudes ranging from 0.053 to 1.47 mag. Of the 72 young ρ Oph star cluster members included in this survey, 79% are variable; in addition, 22 variable stars are identified as candidate members. Based on the temporal behavior of the K s time-series, the variability is distinguished as either periodic, long time-scale or irregular. This temporal behavior coupled with the behavior of stellar colors is used to assign a dominant variability mechanism. A new period-searching algorithm finds periodic signals in 32 variable stars with periods between 0.49 to 92 days. The chief mechanism driving the periodic variability for 18 stars is rotational modulation of cool starspots while 3 periodically vary due to accretion-induced hot spots. The time-series for six variable stars contains discrete periodic ''eclipse-like'' features with periods ranging from 3 to 8 days. These features may be asymmetries in the circumstellar disk, potentially sustained or driven by a proto-planet at or near the co-rotation radius. Aperiodic, long time-scale variations in stellar flux are identified in the time-series for 31 variable stars with time-scales ranging from 64 to 790 days. The chief mechanism driving long time-scale variability is variable extinction or mass accretion rates. The majority of the variable stars (40) exhibit sporadic, aperiodic variability over no discernable time-scale. No chief variability mechanism

PERIODIC AND APERIODIC VARIABILITY IN THE MOLECULAR CLOUD ρ OPHIUCHUS

Energy Technology Data Exchange (ETDEWEB)

Parks, J. Robert; Plavchan, Peter; Gee, Alan H. [Infrared Processing and Analysis Center, California Institute of Technology, Mail Code 100-22, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); White, Russel J., E-mail: parksj@chara.gsu.edu [Georgia State University, Department of Physics and Astronomy, 25 Park Place, Room 605, Atlanta, GA 30303 (United States)

2014-03-01

Presented are the results of a near-IR photometric survey of 1678 stars in the direction of the ρ Ophiuchus (ρ Oph) star forming region using data from the 2MASS Calibration Database. For each target in this sample, up to 1584 individual J-, H-, and K{sub s} -band photometric measurements with a cadence of ∼1 day are obtained over three observing seasons spanning ∼2.5 yr; it is the most intensive survey of stars in this region to date. This survey identifies 101 variable stars with ΔK{sub s} -band amplitudes from 0.044 to 2.31 mag and Δ(J – K{sub s} ) color amplitudes ranging from 0.053 to 1.47 mag. Of the 72 young ρ Oph star cluster members included in this survey, 79% are variable; in addition, 22 variable stars are identified as candidate members. Based on the temporal behavior of the K{sub s} time-series, the variability is distinguished as either periodic, long time-scale or irregular. This temporal behavior coupled with the behavior of stellar colors is used to assign a dominant variability mechanism. A new period-searching algorithm finds periodic signals in 32 variable stars with periods between 0.49 to 92 days. The chief mechanism driving the periodic variability for 18 stars is rotational modulation of cool starspots while 3 periodically vary due to accretion-induced hot spots. The time-series for six variable stars contains discrete periodic ''eclipse-like'' features with periods ranging from 3 to 8 days. These features may be asymmetries in the circumstellar disk, potentially sustained or driven by a proto-planet at or near the co-rotation radius. Aperiodic, long time-scale variations in stellar flux are identified in the time-series for 31 variable stars with time-scales ranging from 64 to 790 days. The chief mechanism driving long time-scale variability is variable extinction or mass accretion rates. The majority of the variable stars (40) exhibit sporadic, aperiodic variability over no discernable time-scale. No chief

Random-effects linear modeling and sample size tables for two special crossover designs of average bioequivalence studies: the four-period, two-sequence, two-formulation and six-period, three-sequence, three-formulation designs.

Science.gov (United States)

Diaz, Francisco J; Berg, Michel J; Krebill, Ron; Welty, Timothy; Gidal, Barry E; Alloway, Rita; Privitera, Michael

2013-12-01

Due to concern and debate in the epilepsy medical community and to the current interest of the US Food and Drug Administration (FDA) in revising approaches to the approval of generic drugs, the FDA is currently supporting ongoing bioequivalence studies of antiepileptic drugs, the EQUIGEN studies. During the design of these crossover studies, the researchers could not find commercial or non-commercial statistical software that quickly allowed computation of sample sizes for their designs, particularly software implementing the FDA requirement of using random-effects linear models for the analyses of bioequivalence studies. This article presents tables for sample-size evaluations of average bioequivalence studies based on the two crossover designs used in the EQUIGEN studies: the four-period, two-sequence, two-formulation design, and the six-period, three-sequence, three-formulation design. Sample-size computations assume that random-effects linear models are used in bioequivalence analyses with crossover designs. Random-effects linear models have been traditionally viewed by many pharmacologists and clinical researchers as just mathematical devices to analyze repeated-measures data. In contrast, a modern view of these models attributes an important mathematical role in theoretical formulations in personalized medicine to them, because these models not only have parameters that represent average patients, but also have parameters that represent individual patients. Moreover, the notation and language of random-effects linear models have evolved over the years. Thus, another goal of this article is to provide a presentation of the statistical modeling of data from bioequivalence studies that highlights the modern view of these models, with special emphasis on power analyses and sample-size computations.

Measurement of large asymptotic reactor periods from about 103 to 4.104 sec) to determine reactivity effects of small samples

International Nuclear Information System (INIS)

Grinevich, F.A.; Evchuk, A.I.; Klimentov, V.B.; Tyzh, A.V.; Churkin, Yu.I.; Yaroshevich, O.I.

1977-01-01

All investigation programs on fast reactor physics include measurements of low reactivity values (1-0.01)x10 -5 ΔK/K. An application of the pile oscillator technique for the purpose requires a special critical assembly for an installation of the oscillator. Thus it is of interest to develop relatively simple methods. In particular, one of such methods is the asymptotic period method which is widely used for low reactivity measurements. The description of the method and equipment developed for low reactivity measurements according to the measurements of the steady-state reactor period is presented. The equipment has been tested on the BTS-2 fast-thermal critical assembly. Measurement results on the reactivity effects of small samples in the fast zone centre are given. It is shown that the application of the method of measuring long steady-state periods and developed and tested equipment enables the reactivity of (1+-0.02)x10 -5 ΔK/K to be determined at the critical assembly power of 5 to 10 Wt. The disadvantage of the method presented is the time lost on reaching the steady-state period which results in greater sensitivity of the method to reactivity drifts

Energy dependence of relative abundances and periods of delayed neutron separate groups from neutron induced fission of 239Pu in the virgin neutron energy range 0.37-4.97 MeV

International Nuclear Information System (INIS)

Piksajkin, V.M.; Kazakov, L.E.; Isaev, S.T.; Korolev, G.G.; Roshchenko, V.A.; Tertychnyj, R.G.

2002-01-01

Relative yield and group period of delayed neutrons induced by the 239 Pu fission in the 0.37-4.97 MeV range were measured. Comparative analysis of experimental data was conducted in terms of middle period of half-life of delayed neutron nuclei-precursors. Character and scale of changing values of delayed neutron group parameters as changing excitation energy of fission compound-nucleus have been demonstrated for the first time. Considerable energy dependence of group parameters under the neutron induced 239 Pu fission that was expressed by the decreasing middle period of half-life of nuclei-precursors by 10 % in the 2.85 eV - 5 MeV range of virgin neutrons was detected [ru

Super-ranging. A new ranging strategy in European badgers.

Directory of Open Access Journals (Sweden)

Aoibheann Gaughran

Full Text Available We monitored the ranging of a wild European badger (Meles meles population over 7 years using GPS tracking collars. Badger range sizes varied seasonally and reached their maximum in June, July and August. We analysed the summer ranging behaviour, using 83 home range estimates from 48 individuals over 6974 collar-nights. We found that while most adult badgers (males and females remained within their own traditional social group boundaries, several male badgers (on average 22% regularly ranged beyond these traditional boundaries. These adult males frequently ranged throughout two (or more social group's traditional territories and had extremely large home ranges. We therefore refer to them as super-rangers. While ranging across traditional boundaries has been recorded over short periods of time for extraterritorial mating and foraging forays, or for pre-dispersal exploration, the animals in this study maintained their super-ranges from 2 to 36 months. This study represents the first time such long-term extra-territorial ranging has been described for European badgers. Holding a super-range may confer an advantage in access to breeding females, but could also affect local interaction networks. In Ireland & the UK, badgers act as a wildlife reservoir for bovine tuberculosis (TB. Super-ranging may facilitate the spread of disease by increasing both direct interactions between conspecifics, particularly across social groups, and indirect interactions with cattle in their shared environment. Understanding super-ranging behaviour may both improve our understanding of tuberculosis epidemiology and inform future control strategies.

Free-ranging farm cats: home range size and predation on a livestock unit in Northwest Georgia.

Directory of Open Access Journals (Sweden)

Susanna E Kitts-Morgan

Full Text Available This study's objective was to determine seasonal and diurnal vs. nocturnal home range size, as well as predation for free-ranging farm cats at a livestock unit in Northwest Georgia. Seven adult cats were tracked with attached GPS units for up to two weeks for one spring and two summer seasons from May 2010 through August 2011. Three and five cats were tracked for up to two weeks during the fall and winter seasons, respectively. Feline scat was collected during this entire period. Cats were fed a commercial cat food daily. There was no seasonal effect (P > 0.05 on overall (95% KDE and 90% KDE or core home range size (50% KDE. Male cats tended (P = 0.08 to have larger diurnal and nocturnal core home ranges (1.09 ha compared to female cats (0.64 ha. Reproductively intact cats (n = 2 had larger (P < 0.0001 diurnal and nocturnal home ranges as compared to altered cats. Feline scat processing separated scat into prey parts, and of the 210 feline scats collected during the study, 75.24% contained hair. Of these 158 scat samples, 86 contained non-cat hair and 72 contained only cat hair. Other prey components included fragments of bone in 21.43% of scat and teeth in 12.86% of scat. Teeth were used to identify mammalian prey hunted by these cats, of which the Hispid cotton rat (Sigmodon hispidus was the primary rodent. Other targeted mammals were Peromyscus sp., Sylvilagus sp. and Microtus sp. Invertebrates and birds were less important as prey, but all mammalian prey identified in this study consisted of native animals. While the free-ranging farm cats in this study did not adjust their home range seasonally, sex and reproductive status did increase diurnal and nocturnal home range size. Ultimately, larger home ranges of free-ranging cats could negatively impact native wildlife.

Assessment of Sampling Error Associated with Collection and Analysis of Soil Samples at a Firing Range Contaminated with HMX

National Research Council Canada - National Science Library

Jenkins, Thomas F

1997-01-01

Short-range and mid-range (grid size) spatial heterogeneity in explosives concentrations within surface soils was studied at an active antitank firing range at the Canadian Force Base-Valcartier, Val-Belair, Quebec...

Legacy K/Ar and 40Ar/39Ar geochronologic data from the Alaska-Aleutian Range batholith of south-central Alaska

Science.gov (United States)

Koeneman, Lisa L.; Wilson, Frederic H.

2018-04-06

Sample descriptions and analytical data for more than 200 K/Ar and 40Ar/39Ar analyses from rocks of the Alaska-Aleutian Range batholith of south-central Alaska are reported here. Samples were collected over a period of 20 years by Bruce R. Reed and Marvin A. Lanphere (both U.S. Geological Survey) as part of their studies of the batholith.

Urine sample collection protocols for bioassay samples

Energy Technology Data Exchange (ETDEWEB)

MacLellan, J.A.; McFadden, K.M.

1992-11-01

In vitro radiobioassay analyses are used to measure the amount of radioactive material excreted by personnel exposed to the potential intake of radioactive material. The analytical results are then used with various metabolic models to estimate the amount of radioactive material in the subject`s body and the original intake of radioactive material. Proper application of these metabolic models requires knowledge of the excretion period. It is normal practice to design the bioassay program based on a 24-hour excretion sample. The Hanford bioassay program simulates a total 24-hour urine excretion sample with urine collection periods lasting from one-half hour before retiring to one-half hour after rising on two consecutive days. Urine passed during the specified periods is collected in three 1-L bottles. Because the daily excretion volume given in Publication 23 of the International Commission on Radiological Protection (ICRP 1975, p. 354) for Reference Man is 1.4 L, it was proposed to use only two 1-L bottles as a cost-saving measure. This raised the broader question of what should be the design capacity of a 24-hour urine sample kit.

Urine sample collection protocols for bioassay samples

Energy Technology Data Exchange (ETDEWEB)

MacLellan, J.A.; McFadden, K.M.

1992-11-01

In vitro radiobioassay analyses are used to measure the amount of radioactive material excreted by personnel exposed to the potential intake of radioactive material. The analytical results are then used with various metabolic models to estimate the amount of radioactive material in the subject's body and the original intake of radioactive material. Proper application of these metabolic models requires knowledge of the excretion period. It is normal practice to design the bioassay program based on a 24-hour excretion sample. The Hanford bioassay program simulates a total 24-hour urine excretion sample with urine collection periods lasting from one-half hour before retiring to one-half hour after rising on two consecutive days. Urine passed during the specified periods is collected in three 1-L bottles. Because the daily excretion volume given in Publication 23 of the International Commission on Radiological Protection (ICRP 1975, p. 354) for Reference Man is 1.4 L, it was proposed to use only two 1-L bottles as a cost-saving measure. This raised the broader question of what should be the design capacity of a 24-hour urine sample kit.

Water born pollutants sampling using porous suction samples

International Nuclear Information System (INIS)

Baig, M.A.

1997-01-01

The common standard method of sampling water born pollutants in the vadoze zone is core sampling and it is followed by extraction of pore fluid. This method does not allow sampling at the same location next time and again later on. There is an alternative approach for sampling fluids (water born pollutants) from both saturated and unsaturated regions of vadose zone using porous suction samplers. There are three types of porous suction samplers, vacuum-operated, pressure-vacuum lysimeters, high pressure vacuum samples. The suction samples are operated in the range of 0-70 centi bars and usually consist of ceramic and polytetrafluorethylene (PTFE). The operation range of PTFE is higher than ceramic cups. These samplers are well suited for in situ and repeated sampling form the same location. This paper discusses the physical properties and operating condition of such samplers to the utilized under our environmental sampling. (author)

Note: long range and accurate measurement of deep trench microstructures by a specialized scanning tunneling microscope.

Science.gov (United States)

Ju, Bing-Feng; Chen, Yuan-Liu; Zhang, Wei; Zhu, Wule; Jin, Chao; Fang, F Z

2012-05-01

A compact but practical scanning tunneling microscope (STM) with high aspect ratio and high depth capability has been specially developed. Long range scanning mechanism with tilt-adjustment stage is adopted for the purpose of adjusting the probe-sample relative angle to compensate the non-parallel effects. A periodical trench microstructure with a pitch of 10 μm has been successfully imaged with a long scanning range up to 2.0 mm. More innovatively, a deep trench with depth and step height of 23.0 μm has also been successfully measured, and slope angle of the sidewall can approximately achieve 67°. The probe can continuously climb the high step and exploring the trench bottom without tip crashing. The new STM could perform long range measurement for the deep trench and high step surfaces without image distortion. It enables accurate measurement and quality control of periodical trench microstructures.

Temporal Variability of Upper-level Winds at the Eastern Range, Western Range and Wallops Flight Facility

Science.gov (United States)

Decker, Ryan; Barbre, Robert E.

2014-01-01

Space launch vehicles incorporate upper-level wind profiles to determine wind effects on the vehicle and for a commit to launch decision. These assessments incorporate wind profiles measured hours prior to launch and may not represent the actual wind the vehicle will fly through. Uncertainty in the upper-level winds over the time period between the assessment and launch can be mitigated by a statistical analysis of wind change over time periods of interest using historical data from the launch range. Five sets of temporal wind pairs at various times (.75, 1.5, 2, 3 and 4-hrs) at the Eastern Range, Western Range and Wallops Flight Facility were developed for use in upper-level wind assessments. Database development procedures as well as statistical analysis of temporal wind variability at each launch range will be presented.

A Range Correction for Icesat and Its Potential Impact on Ice-sheet Mass Balance Studies

Science.gov (United States)

Borsa, A. A.; Moholdt, G.; Fricker, H. A.; Brunt, Kelly M.

2014-01-01

We report on a previously undocumented range error in NASA's Ice, Cloud and land Elevation Satellite (ICESat) that degrades elevation precision and introduces a small but significant elevation trend over the ICESat mission period. This range error (the Gaussian-Centroid or 'G-C'offset) varies on a shot-to-shot basis and exhibits increasing scatter when laser transmit energies fall below 20 mJ. Although the G-C offset is uncorrelated over periods less than1 day, it evolves over the life of each of ICESat's three lasers in a series of ramps and jumps that give rise to spurious elevation trends of -0.92 to -1.90 cm yr(exp -1), depending on the time period considered. Using ICESat data over the Ross and Filchner-Ronne ice shelves we show that (1) the G-C offset introduces significant biases in ice-shelf mass balance estimates, and (2) the mass balance bias can vary between regions because of different temporal samplings of ICESat.We can reproduce the effect of the G-C offset over these two ice shelves by fitting trends to sample-weighted mean G-C offsets for each campaign, suggesting that it may not be necessary to fully repeat earlier ICESat studies to determine the impact of the G-C offset on ice-sheet mass balance estimates.

Periodic and almost periodic solutions for multi-valued differential equations in Banach spaces

Directory of Open Access Journals (Sweden)

E. Hanebaly

2000-03-01

Full Text Available It is known that for $omega$-periodic differential equations of monotonous type, in uniformly convex Banach spaces, the existence of a bounded solution on ${Bbb R}^+$ is equivalent to the existence of an omega-periodic solution (see Haraux [5] and Hanebaly [7, 10]. It is also known that if the Banach space is strictly convex and the equation is almost periodic and of monotonous type, then the existence of a continuous solution with a precompact range is equivalent to the existence of an almost periodic solution (see Hanebaly [8]. In this note we want to generalize the results above for multi-valued differential equations.

All-sky LIGO search for periodic gravitational waves in the early fifth-science-run data.

Science.gov (United States)

Abbott, B P; Abbott, R; Adhikari, R; Ajith, P; Allen, B; Allen, G; Amin, R S; Anderson, S B; Anderson, W G; Arain, M A; Araya, M; Armandula, H; Armor, P; Aso, Y; Aston, S; Aufmuth, P; Aulbert, C; Babak, S; Baker, P; Ballmer, S; Bantilan, H; Barish, B C; Barker, C; Barker, D; Barr, B; Barriga, P; Barsotti, L; Barton, M A; Bartos, I; Bassiri, R; Bastarrika, M; Behnke, B; Benacquista, M; Betzwieser, J; Beyersdorf, P T; Bilenko, I A; Billingsley, G; Biswas, R; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Bland, B; Bodiya, T P; Bogue, L; Bork, R; Boschi, V; Bose, S; Brady, P R; Braginsky, V B; Brau, J E; Brinkmann, M; Brooks, A F; Brown, D A; Brunet, G; Bullington, A; Buonanno, A; Burmeister, O; Byer, R L; Cadonati, L; Cagnoli, G; Camp, J B; Cannizzo, J; Cannon, K C; Cao, J; Cardenas, L; Cardoso, V; Caride, S; Casebolt, T; Castaldi, G; Caudill, S; Cavaglià, M; Cepeda, C; Chalkley, E; Charlton, P; Chatterji, S; Chelkowski, S; Chen, Y; Christensen, N; Clark, D; Clark, J; Clayton, J H; Cokelaer, T; Conte, R; Cook, D; Corbitt, T R C; Cornish, N; Coyne, D C; Creighton, J D E; Creighton, T D; Cruise, A M; Cumming, A; Cunningham, L; Cutler, R M; Danzmann, K; Daudert, B; Davies, G; Debra, D; Degallaix, J; Dergachev, V; Desai, S; Desalvo, R; Dhurandhar, S; Díaz, M; Dickson, J; Dietz, A; Donovan, F; Dooley, K L; Doomes, E E; Drever, R W P; Duke, I; Dumas, J-C; Dwyer, J; Echols, C; Edgar, M; Effler, A; Ehrens, P; Ely, G; Espinoza, E; Etzel, T; Evans, M; Evans, T; Fairhurst, S; Faltas, Y; Fan, Y; Fazi, D; Fejer, M M; Finn, L S; Flasch, K; Foley, S; Forrest, C; Fotopoulos, N; Franzen, A; Frei, Z; Freise, A; Frey, R; Fricke, T T; Fritschel, P; Frolov, V V; Fyffe, M; Garofoli, J A; Gholami, I; Giaime, J A; Giampanis, S; Giardina, K D; Goda, K; Goetz, E; Goggin, L M; González, G; Gossler, S; Gouaty, R; Grant, A; Gras, S; Gray, C; Gray, M; Greenhalgh, R J S; Gretarsson, A M; Grimaldi, F; Grosso, R; Grote, H; Grunewald, S; Guenther, M; Gustafson, E K; Gustafson, R; Hage, B; Hallam, J M; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harstad, E D; Haughian, E; Hayama, K; Hayler, T; Heefner, J; Heng, I S; Heptonstall, A; Hewitson, M; Hild, S; Hirose, E; Hoak, D; Holt, K; Hosken, D; Hough, J; Huttner, S H; Ingram, D; Ito, M; Ivanov, A; Johnson, B; Johnson, W W; Jones, D I; Jones, G; Jones, R; Ju, L; Kalmus, P; Kalogera, V; Kamat, S; Kanner, J; Kasprzyk, D; Katsavounidis, E; Kawabe, K; Kawamura, S; Kawazoe, F; Kells, W; Keppel, D G; Khalaidovski, A; Khalili, F Ya; Khan, R; Khazanov, E; King, P; Kissel, J S; Klimenko, S; Kocsis, B; Kokeyama, K; Kondrashov, V; Kopparapu, R; Koranda, S; Kozak, D; Kozhevatov, I; Krishnan, B; Kwee, P; Landry, M; Lantz, B; Lazzarini, A; Lei, M; Leonor, I; Li, C; Lin, H; Lindquist, P E; Littenberg, T B; Lockerbie, N A; Lodhia, D; Lormand, M; Lu, P; Lubinski, M; Lucianetti, A; Lück, H; Machenschalk, B; Macinnis, M; Mageswaran, M; Mailand, K; Mandel, I; Mandic, V; Márka, S; Márka, Z; Markosyan, A; Markowitz, J; Maros, E; Martin, I W; Martin, R M; Marx, J N; Mason, K; Matichard, F; Matone, L; Matzner, R; Mavalvala, N; McCarthy, R; McClelland, D E; McGuire, S C; McHugh, M; McIntyre, G; McKechan, D; McKenzie, K; Mehmet, M; Melissinos, A; Mendell, G; Mercer, R A; Meshkov, S; Messenger, C J; Meyers, D; Miller, A; Miller, J; Minelli, J; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Miyakawa, O; Moe, B; Mohanty, S D; Moreno, G; Mors, K; Mossavi, K; Mowlowry, C; Mueller, G; Muhammad, D; Mukherjee, S; Mukhopadhyay, H; Mullavey, A; Müller-Ebhardt, H; Munch, J; Murray, P G; Myers, E; Myers, J; Nash, T; Nelson, J; Newton, G; Nishizawa, A; Numata, K; Ochsner, E; O'Dell, J; Ogin, G; O'Reilly, B; O'Shaughnessy, R; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Pan, Y; Pankow, C; Papa, M A; Parameshwaraiah, V; Patel, P; Pedraza, M; Penn, S; Perraca, A; Petrie, T; Pinto, I M; Pitkin, M; Pletsch, H J; Plissi, M V; Postiglione, F; Principe, M; Prix, R; Quetschke, V; Raab, F J; Rabeling, D S; Radkins, H; Raffai, P; Rainer, N; Rakhmanov, M; Ramsunder, M; Reed, T; Rehbein, H; Reid, S; Reitze, D H; Riesen, R; Riles, K; Rivera, B; Robertson, N A; Robinson, C; Robinson, E L; Roddy, S; Rogan, A M; Rollins, J; Romano, J D; Romie, J H; Rowan, S; Rüdiger, A; Ruet, L; Russell, P; Ryan, K; Sakata, S; Sancho de la Jordana, L; Sandberg, V; Sannibale, V; Santamaria, L; Saraf, S; Sarin, P; Sathyaprakash, B S; Sato, S; Saulson, P R; Savage, R; Savov, P; Scanlan, M; Schediwy, S W; Schilling, R; Schnabel, R; Schofield, R; Schutz, B F; Schwinberg, P; Scott, J; Scott, S M; Searle, A C; Sears, B; Seifert, F; Sellers, D; Sengupta, A S; Sergeev, A; Shapiro, B; Shawhan, P; Shoemaker, D H; Sibley, A; Siemens, X; Sigg, D; Sinha, S; Sintes, A M; Slagmolen, B J J; Slutsky, J; Smith, J R; Smith, M R; Smith, N D; Somiya, K; Sorazu, B; Stein, L C; Strain, K A; Stuver, A; Summerscales, T Z; Sun, K-X; Sung, M; Sutton, P J; Takahashi, H; Tanner, D B; Taylor, R; Taylor, R; Thacker, J; Thorne, K A; Thorne, K S; Thüring, A; Tokmakov, K V; Torres, C; Torrie, C; Traylor, G; Trias, M; Ugolini, D; Urbanek, K; Vahlbruch, H; Van Den Broeck, C; van der Sluys, M V; van Veggel, A A; Vass, S; Vaulin, R; Vecchio, A; Veitch, J D; Veitch, P; Villar, A; Vorvick, C; Vyachanin, S P; Waldman, S J; Wallace, L; Ward, H; Ward, R L; Weinert, M; Weinstein, A J; Weiss, R; Wen, L; Wen, S; Wette, K; Whelan, J T; Whitcomb, S E; Whiting, B F; Wilkinson, C; Willems, P A; Williams, H R; Williams, L; Willke, B; Wilmut, I; Winkler, W; Wipf, C C; Wiseman, A G; Woan, G; Wooley, R; Worden, J; Wu, W; Yakushin, I; Yamamoto, H; Yan, Z; Yoshida, S; Zanolin, M; Zhang, J; Zhang, L; Zhao, C; Zotov, N; Zucker, M E; Zur Mühlen, H; Zweizig, J

2009-03-20

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1100 Hz and with the frequency's time derivative in the range -5 x 10{-9}-0 Hz s{-1}. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semicoherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 10{-24} are obtained over a 200-Hz band, and the sensitivity improvement over previous searches increases the spatial volume sampled by an average factor of about 100 over the entire search band. For a neutron star with nominal equatorial ellipticity of 10{-6}, the search is sensitive to distances as great as 500 pc.

Period Changes of 23 Field RR Lyrae Stars

Directory of Open Access Journals (Sweden)

Soo-Chang Rey

1994-12-01

Full Text Available The secular period behavior of 23 field RR Lyrae stars is studied in order to determine if the observed period changes could be attributed, at least in the mean, to stellar evolution. The sample of stars is subdivided into two Oosterhoff groups based on the metallicity and period-shift. Despite the small sample size, we found a distinct bias toward positive period changes in the group variables. The period changes of the group variables in globular clusters. This provides yet another support for the Lee, Demarque, and Zinn(1990 evolutionary models of RR Lyrae stars and their explanation of the Sandage period-shift effect.

Unsynchronized scanning with a low-cost laser range finder for real-time range imaging

Science.gov (United States)

Hatipoglu, Isa; Nakhmani, Arie

2017-06-01

Range imaging plays an essential role in many fields: 3D modeling, robotics, heritage, agriculture, forestry, reverse engineering. One of the most popular range-measuring technologies is laser scanner due to its several advantages: long range, high precision, real-time measurement capabilities, and no dependence on lighting conditions. However, laser scanners are very costly. Their high cost prevents widespread use in applications. Due to the latest developments in technology, now, low-cost, reliable, faster, and light-weight 1D laser range finders (LRFs) are available. A low-cost 1D LRF with a scanning mechanism, providing the ability of laser beam steering for additional dimensions, enables to capture a depth map. In this work, we present an unsynchronized scanning with a low-cost LRF to decrease scanning period and reduce vibrations caused by stop-scan in synchronized scanning. Moreover, we developed an algorithm for alignment of unsynchronized raw data and proposed range image post-processing framework. The proposed technique enables to have a range imaging system for a fraction of the price of its counterparts. The results prove that the proposed method can fulfill the need for a low-cost laser scanning for range imaging for static environments because the most significant limitation of the method is the scanning period which is about 2 minutes for 55,000 range points (resolution of 250x220 image). In contrast, scanning the same image takes around 4 minutes in synchronized scanning. Once faster, longer range, and narrow beam LRFs are available, the methods proposed in this work can produce better results.

Therapeutic efficiency of decimeter range waves and their effect on cerebral circulation in patients during recovery period after surgery performed on intracranial arteries

Energy Technology Data Exchange (ETDEWEB)

Danilova, D.P.; Strelkova, N.I.; Streltsova, E.N.

The goal of this work was to evaluate the therapeutic effect of an electromagnetic field in the decimeter range on focal neurologic symptoms and cerebral circulation in patients recovering from surgery on intracranial arteries. This treatment led to regression of focal neurologic symptoms and improved cerebral circulation in 86.3% of patients who tolerated this procedure rather well. This approach was recommended as a method of choice for rehabilitative treatment during the postsurgical period. 7 references, 1 figure.

A UV spectroscopic survey of periodic M dwarfs in the Hyades

Science.gov (United States)

Agueros, Marcel

2017-08-01

Because of its proximity, the 650-Myr-old Hyades open cluster is a unique resource for exploring the relationship between magnetic activity, rotation, and age in low-mass stars. While the cluster has been largely ignored in UV studies of the dependence of activity on rotation, we now have an extensive and growing set of complementary rotation period, Halpha, and X-ray measurements with which to examine in detail the rotation-activity relation at 650 Myr and to constrain theories of magnetic heating. We propose to measure Mg II line emission, the strongest NUV activity tracer, in COS spectra of 17 Hyads ranging in spectral type from M0 to M7 with known rotation periods and Halpha and X-ray measurements. These stars form a representative sample of M-dwarf Hyads with known periods and are a significant addition to, and expansion of, the sample of 20 mainly solar-mass rotators with existing (mostly low-resolution) International Ultravioled Explorer (IUE) NUV spectra. The Mg II measurements will contribute significantly to our goal of mapping out the rotation-activity relation star-by-star in this benchmark open cluster. This, in turn, will move us toward an improved understanding of the radiation environment and habitability of the exoplanets we continue to find around low-mass stars.

Impacts of visitor number on Kangaroos housed in free-range exhibits.

Science.gov (United States)

Sherwen, Sally L; Hemsworth, Paul H; Butler, Kym L; Fanson, Kerry V; Magrath, Michael J L

2015-01-01

Free range exhibits are becoming increasingly popular in zoos as a means to enhance interaction between visitors and animals. However very little research exists on the impacts of visitors on animal behaviour and stress in free range exhibits. We investigated the effects of visitor number on the behaviour and stress physiology of Kangaroo Island (KI) Kangaroos, Macropus fuliginosus fuliginosus, and Red Kangaroos, Macropus rufus, housed in two free range exhibits in Australian zoos. Behavioural observations were conducted on individual kangaroos at each site using instantaneous scan sampling to record activity (e.g., vigilance, foraging, resting) and distance from the visitor pathway. Individually identifiable faecal samples were collected at the end of each study day and analysed for faecal glucocorticoid metabolite (FGM) concentration. When visitor number increased, both KI Kangaroos and Red Kangaroos increased the time spent engaged in visitor-directed vigilance and KI Kangaroos also increased the time spent engaged in locomotion and decreased the time spent resting. There was no effect of visitor number on the distance kangaroos positioned themselves from the visitor pathway or FGM concentration in either species. While there are limitations in interpreting these results in terms of fear of visitors, there was no evidence of adverse effects animal welfare in these study groups based on avoidance behaviour or stress physiology under the range of visitor numbers that we studied. © 2015 Wiley Periodicals, Inc.

Work Sampling Study of an Engineering Professor during a Regular Contract Period

Science.gov (United States)

Brink, Jan; McDonald, Dale B.

2015-01-01

Work sampling is a technique that has been employed in industry and fields such as healthcare for some time. It is a powerful technique, and an alternative to conventional stop watch time studies, used by industrial engineers to focus upon random work sampling observations. This study applies work sampling to the duties performed by an individual…

Reliability of Serum Metabolites over a Two-Year Period: A Targeted Metabolomic Approach in Fasting and Non-Fasting Samples from EPIC

Science.gov (United States)

Achaintre, David; Sacerdote, Carlotta; Vineis, Paolo; Key, Timothy J.; Onland Moret, N. Charlotte; Scalbert, Augustin; Rinaldi, Sabina; Ferrari, Pietro

2015-01-01

Objective Although metabolic profiles have been associated with chronic disease risk, lack of temporal stability of metabolite levels could limit their use in epidemiological investigations. The present study aims to evaluate the reliability over a two-year period of 158 metabolites and compare reliability over time in fasting and non-fasting serum samples. Methods Metabolites were measured with the AbsolueIDQp180 kit (Biocrates, Innsbruck, Austria) by mass spectrometry and included acylcarnitines, amino acids, biogenic amines, hexoses, phosphatidylcholines and sphingomyelins. Measurements were performed on repeat serum samples collected two years apart in 27 fasting men from Turin, Italy, and 39 non-fasting women from Utrecht, The Netherlands, all participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Reproducibility was assessed by estimating intraclass correlation coefficients (ICCs) in multivariable mixed models. Results In fasting samples, a median ICC of 0.70 was observed. ICC values were fasting samples, the median ICC was 0.54. ICC values were fasting as compared to fasting samples, with a statistically significant difference for 19–36% of acylcarnitines, phosphatidylcholines and sphingomyelins. Conclusion A single measurement per individual may be sufficient for the study of 73% and 52% of the metabolites showing ICCs >0.50 in fasting and non-fasting samples, respectively. ICCs were higher in fasting samples that are preferable to non-fasting. PMID:26274920

Elemental analysis of size-fractionated particulate matter sampled in Goeteborg, Sweden

Energy Technology Data Exchange (ETDEWEB)

Wagner, Annemarie [Department of Chemistry, Atmospheric Science, Goeteborg University, SE-412 96 Goeteborg (Sweden)], E-mail: wagnera@chalmers.se; Boman, Johan [Department of Chemistry, Atmospheric Science, Goeteborg University, SE-412 96 Goeteborg (Sweden); Gatari, Michael J. [Institute of Nuclear Science and Technology, University of Nairobi, P.O. Box 30197-00100, Nairobi (Kenya)

2008-12-15

The aim of the study was to investigate the mass distribution of trace elements in aerosol samples collected in the urban area of Goeteborg, Sweden, with special focus on the impact of different air masses and anthropogenic activities. Three measurement campaigns were conducted during December 2006 and January 2007. A PIXE cascade impactor was used to collect particulate matter in 9 size fractions ranging from 16 to 0.06 {mu}m aerodynamic diameter. Polished quartz carriers were chosen as collection substrates for the subsequent direct analysis by TXRF. To investigate the sources of the analyzed air masses, backward trajectories were calculated. Our results showed that diurnal sampling was sufficient to investigate the mass distribution for Br, Ca, Cl, Cu, Fe, K, Sr and Zn, whereas a 5-day sampling period resulted in additional information on mass distribution for Cr and S. Unimodal mass distributions were found in the study area for the elements Ca, Cl, Fe and Zn, whereas the distributions for Br, Cu, Cr, K, Ni and S were bimodal, indicating high temperature processes as source of the submicron particle components. The measurement period including the New Year firework activities showed both an extensive increase in concentrations as well as a shift to the submicron range for K and Sr, elements that are typically found in fireworks. Further research is required to validate the quantification of trace elements directly collected on sample carriers.

Elemental analysis of size-fractionated particulate matter sampled in Goeteborg, Sweden

International Nuclear Information System (INIS)

Wagner, Annemarie; Boman, Johan; Gatari, Michael J.

2008-01-01

The aim of the study was to investigate the mass distribution of trace elements in aerosol samples collected in the urban area of Goeteborg, Sweden, with special focus on the impact of different air masses and anthropogenic activities. Three measurement campaigns were conducted during December 2006 and January 2007. A PIXE cascade impactor was used to collect particulate matter in 9 size fractions ranging from 16 to 0.06 μm aerodynamic diameter. Polished quartz carriers were chosen as collection substrates for the subsequent direct analysis by TXRF. To investigate the sources of the analyzed air masses, backward trajectories were calculated. Our results showed that diurnal sampling was sufficient to investigate the mass distribution for Br, Ca, Cl, Cu, Fe, K, Sr and Zn, whereas a 5-day sampling period resulted in additional information on mass distribution for Cr and S. Unimodal mass distributions were found in the study area for the elements Ca, Cl, Fe and Zn, whereas the distributions for Br, Cu, Cr, K, Ni and S were bimodal, indicating high temperature processes as source of the submicron particle components. The measurement period including the New Year firework activities showed both an extensive increase in concentrations as well as a shift to the submicron range for K and Sr, elements that are typically found in fireworks. Further research is required to validate the quantification of trace elements directly collected on sample carriers

Sampling Studies at an Air Force Live-Fire Bombing Range Impact Area

National Research Council Canada - National Science Library

Jenkins, Thomas F; Hewitt, Alan D; Ramsey, Charles A; Bjella, Kevin L; Bigl, Susan R; Lambert, Dennis J

2006-01-01

.... The main objective was to assess the effectiveness of using a systematic-random, multi-increment sampling strategy for the collection of representative surface soil samples in areas where bombing...

Lessons learned from a review of post-accident sampling systems, high range effluent monitors and high concentration particulate iodine samplers

International Nuclear Information System (INIS)

Hull, A.P.; Knox, W.H.; White, J.R.

1987-01-01

Post-accident sampling systems (PASS), high range gaseous effluent monitors and sampling systems for particulates and iodine in high concentrations have been reviewed at twenty-one licensee sites in Region I of the US Nuclear Regulatory Commission which includes fifteen BWR's and fourteen PWR's. Although most of the installed PASS met the criteria, the highest operational readiness was found in on-line systems that were also used for routine sampling and analysis. The detectors used in the gaseous effluent monitors included external ion chambers, GM tubes, organic scintillators and Cd-Te solid state crystals. Although all were found acceptable, each had its own inherent limitations in the conversion of detector output to the time varying concentration of a post-accident mixture of noble gases. None of the installed particulate and iodine samplers fully met all of the criteria. Their principal limitations included a lack of documentation showing that they could obtain a representative sample and that many of them would collect of an excessive amount of activity at the design criteria. 10 refs., 4 figs., 5 tabs

EXPLORING THE VARIABLE SKY WITH LINEAR. III. CLASSIFICATION OF PERIODIC LIGHT CURVES

Energy Technology Data Exchange (ETDEWEB)

Palaversa, Lovro; Eyer, Laurent; Rimoldini, Lorenzo [Observatoire Astronomique de l' Université de Genève, 51 chemin des Maillettes, CH-1290 Sauverny (Switzerland); Ivezić, Željko; Loebman, Sarah; Hunt-Walker, Nicholas; VanderPlas, Jacob; Westman, David; Becker, Andrew C. [Department of Astronomy, University of Washington, P.O. Box 351580, Seattle, WA 98195-1580 (United States); Ruždjak, Domagoj; Sudar, Davor; Božić, Hrvoje [Hvar Observatory, Faculty of Geodesy, Kačićeva 26, 10000 Zagreb (Croatia); Galin, Mario [Faculty of Geodesy, Kačićeva 26, 10000 Zagreb (Croatia); Kroflin, Andrea; Mesarić, Martina; Munk, Petra; Vrbanec, Dijana [Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, 10000 Zagreb (Croatia); Sesar, Branimir [Division of Physics, Mathematics, and Astronomy, Caltech, Pasadena, CA 91125 (United States); Stuart, J. Scott [Lincoln Laboratory, Massachusetts Institute of Technology, 244 Wood Street, Lexington, MA 02420-9108 (United States); Srdoč, Gregor, E-mail: lovro.palaversa@unige.ch [Saršoni 90, 51216 Viškovo (Croatia); and others

2013-10-01

We describe the construction of a highly reliable sample of ∼7000 optically faint periodic variable stars with light curves obtained by the asteroid survey LINEAR across 10,000 deg{sup 2} of the northern sky. The majority of these variables have not been cataloged yet. The sample flux limit is several magnitudes fainter than most other wide-angle surveys; the photometric errors range from ∼0.03 mag at r = 15 to ∼0.20 mag at r = 18. Light curves include on average 250 data points, collected over about a decade. Using Sloan Digital Sky Survey (SDSS) based photometric recalibration of the LINEAR data for about 25 million objects, we selected ∼200,000 most probable candidate variables with r < 17 and visually confirmed and classified ∼7000 periodic variables using phased light curves. The reliability and uniformity of visual classification across eight human classifiers was calibrated and tested using a catalog of variable stars from the SDSS Stripe 82 region and verified using an unsupervised machine learning approach. The resulting sample of periodic LINEAR variables is dominated by 3900 RR Lyrae stars and 2700 eclipsing binary stars of all subtypes and includes small fractions of relatively rare populations such as asymptotic giant branch stars and SX Phoenicis stars. We discuss the distribution of these mostly uncataloged variables in various diagrams constructed with optical-to-infrared SDSS, Two Micron All Sky Survey, and Wide-field Infrared Survey Explorer photometry, and with LINEAR light-curve features. We find that the combination of light-curve features and colors enables classification schemes much more powerful than when colors or light curves are each used separately. An interesting side result is a robust and precise quantitative description of a strong correlation between the light-curve period and color/spectral type for close and contact eclipsing binary stars (β Lyrae and W UMa): as the color-based spectral type varies from K4 to F5, the

Systematic sampling with errors in sample locations

DEFF Research Database (Denmark)

Ziegel, Johanna; Baddeley, Adrian; Dorph-Petersen, Karl-Anton

2010-01-01

analysis using point process methods. We then analyze three different models for the error process, calculate exact expressions for the variances, and derive asymptotic variances. Errors in the placement of sample points can lead to substantial inflation of the variance, dampening of zitterbewegung......Systematic sampling of points in continuous space is widely used in microscopy and spatial surveys. Classical theory provides asymptotic expressions for the variance of estimators based on systematic sampling as the grid spacing decreases. However, the classical theory assumes that the sample grid...... is exactly periodic; real physical sampling procedures may introduce errors in the placement of the sample points. This paper studies the effect of errors in sample positioning on the variance of estimators in the case of one-dimensional systematic sampling. First we sketch a general approach to variance...

Solar wind plasma periodicities observed at 1 AU by IMP 8

Science.gov (United States)

Paularena, K. I.; Szabo, A.; Lazarus, A. J.

1995-01-01

The IMP 8 spacecraft has been in Earth orbit since 1973, gathering plasma data over one complete 22-year solar cycle. These data are being examined to look for periodicities at time scales ranging from several hours to the entire span of the data set. A 1.3-year periodicity in the radial speed observed by IMP 8 and Voyager 2 has already been reported for the years from 1987 to 1993. The periodogram method, useful for unevenly sampled data such as the IMP 8 plasma data, has been used to search for other periods. It is interesting to note that the 13-year period is not present in the out-of-the-ecliptic component of the velocity (Vz), although a 1-year period is very obvious both visually and on the periodogram. Both components show a very strong peak associated with the 11-year solar cycle variation. This work will be extended to the thermal speed (a measure of the wind's temperature) and density, although the frequent correlations between these parameters and the velocity are expected to cause similar results. Additionally, the fine resolution data will be examined for shorter time periods than are visible using the hourly average data which are appropriate for longer periods. A comparison with periods observed at other spacecraft may also be made.

Multiscale periodicities in aerosol optical depth over India

International Nuclear Information System (INIS)

Ramachandran, S; Ghosh, Sayantan; Verma, Amit; Panigrahi, P K

2013-01-01

Aerosols exhibit periodic or cyclic variations depending on natural and anthropogenic sources over a region, which can become modulated by synoptic meteorological parameters such as winds, rainfall and relative humidity, and long-range transport. Information on periodicity and phase in aerosol properties assumes significance in prediction as well as examining the radiative and climate effects of aerosols including their association with changes in cloud properties and rainfall. Periodicity in aerosol optical depth, which is a columnar measure of aerosol distribution, is determined using continuous wavelet transform over 35 locations (capitals of states and union territories) in India. Continuous wavelet transform is used in the study because continuous wavelet transform is better suited to the extraction of the periodic and local modulations present in various frequency ranges when compared to Fourier transform. Monthly mean aerosol optical depths (AODs) from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Terra satellite at 1° × 1° resolution from January 2001 to December 2012 are used. Annual and quasi-biennial oscillations (QBOs) in AOD are evident in addition to the weak semi-annual (5–6 months) and quasi-triennial oscillations (∼40 months). The semi-annual and annual oscillations are consistent with the seasonal and yearly cycle of variations in AODs. The QBO type periodicity in AOD is found to be non-stationary while the annual period is stationary. The 40 month periodicity indicates the presence of long term correlations in AOD. The observed periodicities in MODIS Terra AODs are also evident in the ground-based AOD measurements made over Kanpur in the Indo-Gangetic Plain. The phase of the periodicity in AOD is stable in the mid-frequency range, while local disturbances in the high-frequency range and long term changes in the atmospheric composition give rise to unstable phases in the low-frequency range. The presence of phase

Is Young Adulthood a Critical Period for Suicidal Behavior among Sexual Minorities? Results from a US National Sample.

Science.gov (United States)

Fish, Jessica N; Rice, Cara E; Lanza, Stephanie T; Russell, Stephen T

2018-03-29

The developmental timing of suicide-related disparities between heterosexuals and sexual minorities (i.e., lesbian/gay and bisexual (LGB) people) is an understudied area that has critical prevention implications. In addition to developmentally situated experiences that shape risk for suicidality in the general population, sexual minorities also experience unique social stressors (e.g., anti-LGB stigma) that may alter their risk for suicidal behavior at different ages. Using a nationally representative US sample of adults, we assessed age-varying rates of suicidal behavior among heterosexuals and sexual minorities ages 18 to 60 and the age-varying association between anti-LGB discrimination and suicidal behavior. We also tested whether these age-varying prevalences and associations differed for men and women and for sexual minorities who did and did not endorse a sexual minority identity. Results indicate a critical period for suicide behavior risk for sexual minorities during young adulthood, with the highest rates of risk at age 18 followed by a steady decline until the early 40s. Disparities were particularly robust for sexual minorities who identified as lesbian, gay, or bisexual. This pattern was present for both men and women, though sexual minority women in their 30s were more likely to report suicidal behavior than heterosexuals and sexual minority men. Sexual minorities who experienced anti-LGB discrimination were more likely to report suicidal behavior, but the significance of this association was limited to those under 30. The effect of discrimination on suicidal behavior was stronger among young adult sexual minority men, relative to sexual minority women, but was present for a wider age range for sexual minority women (until age 30) relative to sexual minority men (until age 25).

Remote sampling of process fluids in radiochemical plants

International Nuclear Information System (INIS)

Sengar, P.B.; Bhattacharya, R.; Ozarde, P. D.; Rana, D.S.

1990-01-01

Sampling of process fluids, continuous or periodic, is an essential requirement in any chemical process plant, so as to keep a control on process variables. In a radiochemical plant the task of taking and conveying the samples is a very tricky affair. This is due to the fact that neither the vessels/equipment containing radioactive effluents can be approached for manual sampling nor sampled fluids can be handled directly. The problems become more accute with higher levels of radioactivity. As such, inovative systems have to be devised to obtain and handle the raioactive samples employing remote operations. The remote sampling system developed in this Division has some of the unique features such as taking only requisite amount of samples in microlitre range, practically maintenance free design, avoidence of excess radioactive fluids coming out of process systems, etc. The paper describes in detail the design of remote sampling system and compares the same with existing systems. The design efforts are towards simplicity in operation, obtaining homogenised representative samples and highly economical on man-rem expenditure. The performance of a prototype system has also been evaluated. (author). 3 refs

Medium Range Forecasts Representation (and Long Range Forecasts?)

Science.gov (United States)

Vincendon, J.-C.

2009-09-01

The progress of the numerical forecasts urges us to interest us in more and more distant ranges. We thus supply more and more forecasts with term of some days. Nevertheless, precautions of use are necessary to give the most reliable and the most relevant possible information. Available in a TV bulletin or on quite other support (Internet, mobile phone), the interpretation and the representation of a medium range forecast (5 - 15 days) must be different from those of a short range forecast. Indeed, the "foresee-ability” of a meteorological phenomenon decreases gradually in the course of the ranges, it decreases all the more quickly that the phenomenon is of small scale. So, at the end of some days, the probability character of a forecast becomes very widely dominating. That is why in Meteo-France the forecasts of D+4 to D+7 are accompanied with a confidence index since around ten years. It is a figure between 1 and 5: the more we approach 5, the more the confidence in the supplied forecast is good. In the practice, an indication is supplied for period D+4 / D+5, the other one for period D+6 / D+7, every day being able to benefit from a different forecast, that is be represented in a independent way. We thus supply a global tendency over 24 hours with less and less precise symbols as the range goes away. Concrete examples will be presented. From now on two years, we also publish forecasts to D+8 / J+9, accompanied with a sign of confidence (" good reliability " or " to confirm "). These two days are grouped together on a single map because for us, the described tendency to this term is relevant on a duration about 48 hours with a spatial scale slightly superior to the synoptic scale. So, we avoid producing more than two zones of types of weather over France and we content with giving an evolution for the temperatures (still, in increase or in decline). Newspapers began to publish this information, it should soon be the case of televisions. It is particularly

An improved test for periodicity

International Nuclear Information System (INIS)

Davies, S.R.

1990-01-01

I discuss two widely used methods of testing for periodicity, phase dispersion minimization and epoch-folding. Using an analysis of variance approach, I demonstrate the close relationship between these two methods. I also show that the significance test sometimes used in phase dispersion minimization is statistically inaccurate, and that the test used in epoch-folding is an approximation valid only for large sample sizes. I propose a new test statistic, applicable to either epoch-folding or PDM, which is statistically sound for all sample sizes, and which is also more sensitive to periodicity than the test statistics previously used with these two methods. (author)

Individualized Sampling Parameters for Behavioral Observations: Enhancing the Predictive Validity of Competing Stimulus Assessments

Science.gov (United States)

DeLeon, Iser G.; Toole, Lisa M.; Gutshall, Katharine A.; Bowman, Lynn G.

2005-01-01

Recent studies have used pretreatment analyses, termed competing stimulus assessments, to identify items that most effectively displace the aberrant behavior of individuals with developmental disabilities. In most studies, there appeared to have been no systematic basis for selecting the sampling period (ranging from 30 s to 10 min) in which items…

Microprocessor controlled digital period meter

International Nuclear Information System (INIS)

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

1980-01-01

A microprocessor controlled digital period meter has been developed and tested operationally on a reactor at Argonne National Laboratory. The principle of operation is the mathematical relationship between asymptotic periods and pulse counting circuitry. This relationship is used to calculate and display the reactor periods over a range of /plus or minus/1 second to /plus or minus/999 seconds. The time interval required to update each measurement automatically varies from 8 seconds at the lowest counting rates to 2 seconds at higher counting rates. The paper will describe hardware and software design details and show the advantages of this type of Period Meter over the conventional circuits. 1 ref

Indirect spectrophotometric determination of arbutin, whitening agent through oxidation by periodate and complexation with ferric chloride

Science.gov (United States)

Barsoom, B. N.; Abdelsamad, A. M. E.; Adib, N. M.

2006-07-01

A simple and accurate spectrophotometric method for the determination of arbutin (glycosylated hydroquinone) is described. It is based on the oxidation of arbutin by periodate in presence of iodate. Excess periodate causes liberation of iodine at pH 8.0. The unreacted periodate is determined by measurement of the liberated iodine spectrophotometrically in the wavelength range (300-500 nm). A calibration curve was constructed for more accurate results and the correlation coefficient of linear regression analysis was -0.9778. The precision of this method was better than 6.17% R.S.D. ( n = 3). Regression analysis of Bear-Lambert plot shows good correlation in the concentration range 25-125 ug/ml. The identification limit was determined to be 25 ug/ml a detailed study of the reaction conditions was carried out, including effect of changing pH, time, temperature and volume of periodate. Analyzing pure and authentic samples containing arbutin tested the validity of the proposed method which has an average percent recovery of 100.86%. An alternative method is also proposed which involves a complexation reaction between arbutin and ferric chloride solution. The produced complex which is yellowish-green in color was determined spectophotometrically.

Psychostimulant use among college students during periods of high and low stress: an interdisciplinary approach utilizing both self-report and unobtrusive chemical sample data.

Science.gov (United States)

Moore, David R; Burgard, Daniel A; Larson, Ramsey G; Ferm, Mikael

2014-05-01

This study quantified psychostimulant use patterns over periods of high and low stress from both self-report measures and chemical wastewater analyses and identified possible predictors of psychostimulant abuse on a college campus. Self-report data were collected at three times of varying stress levels throughout one college semester: during the first week of school (N=676), midterms (N=468), and shortly before final exams (N=400). Campus wastewater samples were collected over 72-hour periods during the same time frames as the surveys. The metabolites of Adderall and Ritalin were quantified through solid phase extraction and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples were normalized with creatinine. Evidence was found to suggest an increase in psychostimulant use during periods of stress, with significant differences found from self-report data between the first week and midterms and from chemical data between these same two assessment periods as well as between the first week of classes and finals. Key predictors of lifetime non-prescriptive psychostimulant use included self-reported procrastination and poor time-management, use of other substances (especially nicotine/tobacco, alcohol, and cocaine), and students' perception of non-prescriptive psychostimulant use as normative on campus. The findings shed further light on psychostimulant use patterns among college students, particularly as a function of stress; the study also highlights the benefit of utilizing an interdisciplinary approach that uses both subjective and objective empirical data. The results have implications for prevention/intervention programs on college campuses designed to reduce stress and facilitate healthier coping. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impact of Continuous Cropping on the Diurnal Range of Dew Point Temperature during the Foliar Expansion Period of Annual Crops on the Canadian Prairies

Directory of Open Access Journals (Sweden)

Bharat M. Shrestha

2016-01-01

Full Text Available It is important to increase our knowledge of the role of land use in changing the regional climate. This study asked, “Has the increase in continuous cropping over the past 50 years on the Canadian Prairies influenced the daily mean and range of morning dew point temperatures (Td during the foliar expansion period (from mid-June to mid-July of annual field crops?” We found that there has been a general increase in the decadal average of mean daily Td and in the range of morning Td from the 1960s to the 2000s. The increase in the observed range of Td between the daily minimum value, which typically occurs near sunrise, and the late morning peak was found to be related to the increase in annual crop acreage and consequent decrease in summerfallow area. The relationship was more significant in the subhumid climatic zone than in the semiarid climatic zone, and it was influenced by whether the region was experiencing either wet, normal, or dry conditions.

Modeling calcification periods of Cytheridella ilosvayi from Florida based on isotopic signatures and hydrological data

Directory of Open Access Journals (Sweden)

J. Meyer

2017-11-01

Full Text Available The isotopic signatures of ostracod shells are the result of the temperature and composition of their host water and the phenology and ecology of the target species. Investigations addressing the influence of site-specific environmental variations on the isotopic ranges of ostracod shells are still rare but can provide important information on habitat-dependent variations and may signify a seasonally restricted timing of calcification periods. Here we present isotopic signatures (δ18Oostr, δ13Costr of living Cytheridella ilosvayi (Ostracoda and physical, chemical, and isotopic (δD, δ18Owater, δ13CDIC compositions of 14 freshwater habitats (rivers, lakes, canals, marshes, sinkholes in South Florida from winter 2013 and summer 2014. We also present instrumental data of river temperatures and δ18O of precipitation (δ18Oprec from this region. The physicochemical and isotopic compositions of the selected sites characterize the different habitats and show the influence of the source water, biological activity, and duration of exposure to the surface. Mean δ18Oostr and δ13Costr signatures of C. ilosvayi shells correlate well with the isotopic composition of their host waters. Within-sample variabilities in repeated isotopic measurements of single ostracod shells reflect habitat-dependent ranges. The similarly high range of ostracod δ18O in rivers and one marsh sample indicates that both temperature and δ18Oprec are responsible for their variation in the whole study area. Rivers and canals, which are predominantly influenced by the input and mixing of inorganic carbon from the catchment, show smaller δ13Costr ranges than the marsh dominated by local fluctuations in biological activities. Based on these observations, background data of water temperatures and δ18Oprec were used to calculate monthly δ18O variations in a theoretical calcite formed in rivers in Florida assuming a direct reaction on precipitation changes. The calculated values

ROTATION PERIODS OF YOUNG BROWN DWARFS: K2 SURVEY IN UPPER SCORPIUS

Energy Technology Data Exchange (ETDEWEB)

Scholz, Alexander [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Kostov, Veselin [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Jayawardhana, Ray [Faculty of Science, York University, 355 Lumbers Building, 4700 Keele Street, Toronto, ON M3J 1P2 (Canada); Mužić, Koraljka, E-mail: as110@st-andrews.ac.uk [Nucleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejercito 441, Santiago (Chile)

2015-08-20

We report rotational periods for 16 young brown dwarfs in the nearby Upper Scorpius association, based on 72 days of high-cadence, high-precision photometry from the Keplerspace telescope’s K2 mission. The periods range from a few hours to two days (plus one outlier at five days), with a median just above one day, confirming that brown dwarfs, except at the very youngest ages, are fast rotators. Interestingly, four of the slowest rotators in our sample exhibit mid-infrared excess emission from disks; at least two also show signs of disk eclipses and accretion in the light curves. Comparing these new periods with those for two other young clusters and simple angular momentum evolution tracks, we find little or no rotational braking in brown dwarfs between 1–10 Myr, in contrast to low-mass stars. Our findings show that disk braking, while still at work, is inefficient in the substellar regime, thus providing an important constraint on the mass dependence of the braking mechanism.

ROTATION PERIODS OF YOUNG BROWN DWARFS: K2 SURVEY IN UPPER SCORPIUS

International Nuclear Information System (INIS)

Scholz, Alexander; Kostov, Veselin; Jayawardhana, Ray; Mužić, Koraljka

2015-01-01

We report rotational periods for 16 young brown dwarfs in the nearby Upper Scorpius association, based on 72 days of high-cadence, high-precision photometry from the Keplerspace telescope’s K2 mission. The periods range from a few hours to two days (plus one outlier at five days), with a median just above one day, confirming that brown dwarfs, except at the very youngest ages, are fast rotators. Interestingly, four of the slowest rotators in our sample exhibit mid-infrared excess emission from disks; at least two also show signs of disk eclipses and accretion in the light curves. Comparing these new periods with those for two other young clusters and simple angular momentum evolution tracks, we find little or no rotational braking in brown dwarfs between 1–10 Myr, in contrast to low-mass stars. Our findings show that disk braking, while still at work, is inefficient in the substellar regime, thus providing an important constraint on the mass dependence of the braking mechanism

Range-efficient consistent sampling and locality-sensitive hashing for polygons

DEFF Research Database (Denmark)

Gudmundsson, Joachim; Pagh, Rasmus

2017-01-01

Locality-sensitive hashing (LSH) is a fundamental technique for similarity search and similarity estimation in high-dimensional spaces. The basic idea is that similar objects should produce hash collisions with probability significantly larger than objects with low similarity. We consider LSH for...... or union of a set of preprocessed polygons. Curiously, our consistent sampling method uses transformation to a geometric problem....

Sampling of ore

International Nuclear Information System (INIS)

Boehme, R.C.; Nicholas, B.L.

1987-01-01

This invention relates to a method of an apparatus for ore sampling. The method includes the steps of periodically removing a sample of the output material of a sorting machine, weighing each sample so that each is of the same weight, measuring a characteristic such as the radioactivity, magnetivity or the like of each sample, subjecting at least an equal portion of each sample to chemical analysis to determine the mineral content of the sample and comparing the characteristic measurement with desired mineral content of the chemically analysed portion of the sample to determine the characteristic/mineral ratio of the sample. The apparatus includes an ore sample collector, a deflector for deflecting a sample of ore particles from the output of an ore sorter into the collector and means for moving the deflector from a first position in which it is clear of the particle path from the sorter to a second position in which it is in the particle path at predetermined time intervals and for predetermined time periods to deflect the sample particles into the collector. The apparatus conveniently includes an ore crusher for comminuting the sample particle, a sample hopper means for weighing the hopper, a detector in the hopper for measuring a characteristic such as radioactivity, magnetivity or the like of particles in the hopper, a discharge outlet from the hopper and means for feeding the particles from the collector to the crusher and then to the hopper

Sampling and examination methods used for TMI-2 samples

International Nuclear Information System (INIS)

Marley, A.W.; Akers, D.W.; McIsaac, C.V.

1988-01-01

The purpose of this paper is to summarize the sampling and examination techniques that were used in the collection and analysis of TMI-2 samples. Samples ranging from auxiliary building air to core debris were collected and analyzed. Handling of the larger samples and many of the smaller samples had to be done remotely and many standard laboratory analytical techniques were modified to accommodate the extremely high radiation fields associated with these samples. The TMI-2 samples presented unique problems with sampling and the laboratory analysis of prior molten fuel debris. 14 refs., 8 figs

Adult Hematology and Clinical Chemistry Laboratory Reference Ranges in a Zimbabwean Population.

Science.gov (United States)

Samaneka, Wadzanai P; Mandozana, Gibson; Tinago, Willard; Nhando, Nehemiah; Mgodi, Nyaradzo M; Bwakura-Dangarembizi, Mutsawashe F; Munjoma, Marshall W; Gomo, Zvenyika A R; Chirenje, Zvavahera M; Hakim, James G

2016-01-01

Laboratory reference ranges used for clinical care and clinical trials in various laboratories in Zimbabwe were derived from textbooks and research studies conducted more than ten years ago. Periodic verification of these ranges is essential to track changes over time. The purpose of this study was to establish hematology and chemistry laboratory reference ranges using more rigorous methods. A community-based cross-sectional study was carried out in Harare, Chitungwiza, and Mutoko. A multistage sampling technique was used. Samples were transported from the field for analysis at the ISO15189 certified University of Zimbabwe-University of California San Francisco Central Research Laboratory. Hematology and clinical chemistry reference ranges lower and upper reference limits were estimated at the 2.5th and 97.5th percentiles respectively. A total of 769 adults (54% males) aged 18 to 55 years were included in the analysis. Median age was 28 [IQR: 23-35] years. Males had significantly higher red cell counts, hemoglobin, hematocrit, and mean corpuscular hemoglobin compared to females. Females had higher white cell counts, platelets, absolute neutrophil counts, and absolute lymphocyte counts compared to males. There were no gender differences in eosinophils, monocytes, and absolute basophil count. Males had significantly higher levels of urea, sodium, potassium, calcium, creatinine, amylase, total protein, albumin and liver enzymes levels compared to females. Females had higher cholesterol and lipase compared with males. There are notable differences in the white cell counts, neutrophils, cholesterol, and creatinine kinase when compared with the currently used reference ranges. Data from this study provides new country specific reference ranges which should be immediately adopted for routine clinical care and accurate monitoring of adverse events in research studies.

Hardware test program for evaluation of baseline range/range rate sensor concept

Science.gov (United States)

Pernic, E.

1985-01-01

The test program Phase II effort provides additional design information in terms of range and range rate (R/R) sensor performance when observing and tracking a typical spacecraft target. The target used in the test program was a one-third scale model of the Hubble Space Telescope (HST) available at the MSFC test site where the tests were performed. A modified Bendix millimeter wave radar served as the R/R sensor test bed for evaluation of range and range rate tracking performance, and generation of radar signature characteristics of the spacecraft target. A summary of program test results and conclusions are presented along with detailed description of the Bendix test bed radar with accompaning instrumentation. The MSFC test site and facilities are described. The test procedures used to establish background levels, and the calibration procedures used in the range accuracy tests and RCS (radar cross section) signature measurements, are presented and a condensed version of the daily log kept during the 5 September through 17 September test period is also presented. The test program results are given starting with the RCS signature measurements, then continuing with range measurement accuracy test results and finally the range and range rate tracking accuracy test results.

The influence of incommensurability on the long-range periodicity of the Pd(100)-(√{ 5 } ×√{ 5 })R27°-PdO(101)

Science.gov (United States)

Shipilin, Mikhail; Stierle, Andreas; Merte, Lindsay R.; Gustafson, Johan; Hejral, Uta; Martin, Natalia M.; Zhang, Chu; Franz, Dirk; Kilic, Volkan; Lundgren, Edvin

2017-06-01

The structural model of the (√{ 5 } ×√{ 5 })R27°-PdO(101) surface oxide grown on Pd(100) has been proposed and refined by a number of authors over more than a decade. In the current contribution we discuss the long-range periodicity of this structure arising along one of the crystallographic directions due to its incommensurability with the substrate. Analyzing the results of surface sensitive diffraction studies, we determined a slight distortion of the previously reported perfect (√{ 5 } ×√{ 5 })R27° surface oxide unit cell. Considering it, we were able to achieve both qualitatively and quantitatively better fit to the experimental diffraction data than it was possible for the perfect structure. Further, taking into account the experimentally obtained scanning tunneling microscopy data and closely examining high-resolution patterns recorded by means of high-energy surface X-ray diffraction, we developed a qualitative structural model based on a larger non-orthogonal surface unit cell to shed more light on the long-range order of the PdO(101) surface oxide. The model comprises a shift of the atoms of the PdO perpendicularly to the direction of the incommensurability to correct for it. This structural model reproduces the fine details of the high-resolution diffraction patterns and qualitatively explains the periodic stripes of structural distortion observed in the images recorded by a scanning tunneling microscope.

Post mortem concentrations of endogenous gamma hydroxybutyric acid (GHB) and in vitro formation in stored blood and urine samples.

Science.gov (United States)

Busardò, Francesco Paolo; Bertol, Elisabetta; Vaiano, Fabio; Baglio, Giovanni; Montana, Angelo; Barbera, Nunziata; Zaami, Simona; Romano, Guido

2014-10-01

Gamma-hydroxybutyrate (GHB) is a central nervous system depressant, primarily used as a recreational drug of abuse with numerous names. It has also been involved in various instances of drug-facilitated sexual assault due to its potential incapacitating effects. The first aim of this paper is to measure the post-mortem concentration of endogenous GHB in whole blood and urine samples of 30 GHB free-users, who have been divided according to the post-mortem interval (PMI) in three groups (first group: 24-36h; second group: 37-72h; third group: 73-192h), trying to evaluate the role of PMI in affecting post mortem levels. Second, the Authors have evaluated the new formation of GHB in vitro in blood and urine samples of the three groups, which have been stored at -20°C, 4°C and 20°C over a period of one month. The concentrations were measured by GC-MS after liquid-liquid extraction according to the method validated and published by Elliot (For. Sci. Int., 2003). For urine samples, GHB concentrations were creatinine-normalized. In the first group the GHB mean concentration measured after autopsy was: 2.14mg/L (range 0.54-3.21mg/L) in blood and 3.90mg/g (range 0.60-4.81mg/g) in urine; in the second group it was: 5.13mg/L (range 1.11-9.60mg/L) in blood and 3.93mg/g (range 0.91-7.25mg/g) in urine; in the third group it was: 11.8mg/L (range 3.95-24.12mg/L) in blood and 9.83mg/g (range 3.67-21.90mg/g) in urine. The results obtained in blood and urine samples showed a statistically significant difference among groups (pblood and urine samples a mean difference at 20°C compared to -20°C not statistically significant at the 10% level. These findings allow us to affirm that the PMI strongly affects the post mortem production of GHB in blood and urine samples. Regarding the new formation of GHB in vitro both in blood and urine samples of the three groups, which have been stored at -20°C, 4°C and 20°C over a period of one month, although there was no significant increases of

Ranging Behaviour of Commercial Free-Range Laying Hens.

Science.gov (United States)

Chielo, Leonard Ikenna; Pike, Tom; Cooper, Jonathan

2016-04-26

In this study, the range use and behaviour of laying hens in commercial free-range flocks was explored. Six flocks were each visited on four separate days and data collected from their outdoor area (divided into zones based on distance from shed and available resources). These were: apron (0-10 m from shed normally without cover or other enrichments); enriched belt (10-50 m from shed where resources such as manmade cover, saplings and dust baths were provided); and outer range (beyond 50 m from shed with no cover and mainly grass pasture). Data collection consisted of counting the number of hens in each zone and recording behaviour, feather condition and nearest neighbour distance (NND) of 20 birds per zone on each visit day. In addition, we used techniques derived from ecological surveys to establish four transects perpendicular to the shed, running through the apron, enriched belt and outer range. Number of hens in each 10 m × 10 m quadrat was recorded four times per day as was the temperature and relative humidity of the outer range. On average, 12.5% of hens were found outside. Of these, 5.4% were found in the apron; 4.3% in the enriched zone; and 2.8% were in the outer range. This pattern was supported by data from quadrats, where the density of hens sharply dropped with increasing distance from shed. Consequently, NND was greatest in the outer range, least in the apron and intermediate in the enriched belt. Hens sampled in outer range and enriched belts had better feather condition than those from the apron. Standing, ground pecking, walking and foraging were the most commonly recorded activities with standing and pecking most likely to occur in the apron, and walking and foraging more common in the outer range. Use of the outer range declined with lower temperatures and increasing relative humidity, though use of apron and enriched belt was not affected by variation in these measures. These data support previous findings that outer range areas tend to be

ROTATION PERIODS AND AGES OF SOLAR ANALOGS AND SOLAR TWINS REVEALED BY THE KEPLER MISSION

International Nuclear Information System (INIS)

Do Nascimento Jr, J.-D.; Meibom, S.; García, R. A.; Salabert, D.; Ceillier, T.; Mathur, S.; Anthony, F.; Da Costa, J. S.; Castro, M.; Barnes, S. A.

2014-01-01

A new sample of solar analogs and twin candidates has been constructed and studied, paying particular attention to their light curves from NASA's Kepler mission. This Letter aims to assess their evolutionary status, derive their rotation and ages, and identify those which are solar analogs or solar twin candidates. We separate out the subgiants that compose a large fraction of the asteroseismic sample, and which show an increase in the average rotation period as the stars ascend the subgiant branch. The rotation periods of the dwarfs, ranging from 6 to 30 days and averaging 19 days, allow us to assess their individual evolutionary states on the main sequence and to derive their ages using gyrochronology. These ages are found to be in agreement with a correlation coefficient of r = 0.79 with independent asteroseismic ages, where available. As a result of this investigation, we are able to identify 34 stars as solar analogs and 22 of them as solar twin candidates

ROTATION PERIODS AND AGES OF SOLAR ANALOGS AND SOLAR TWINS REVEALED BY THE KEPLER MISSION

Energy Technology Data Exchange (ETDEWEB)

Do Nascimento Jr, J.-D.; Meibom, S. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); García, R. A.; Salabert, D.; Ceillier, T. [Laboratoire AIM, CEA/DSM,CNRS, Univ. Paris Diderot-IRFU/SAp, Centre de Saclay, F-91191 Gif-sur-Yvette Cedex (France); Mathur, S. [Space Science Institute, 4750 Walnut Street Suite 205, Boulder CO 80301 (United States); Anthony, F.; Da Costa, J. S.; Castro, M. [Universidade Federal do Rio Grande do Norte, UFRN, Dep. de Física Teórica e Experimental, DFTE, CP 1641, 59072-970 Natal, RN (Brazil); Barnes, S. A., E-mail: jdonascimento@cfa.harvard.edu [Leibniz-Institute for Astrophysics, Potsdam D-14467 (Germany)

2014-08-01

A new sample of solar analogs and twin candidates has been constructed and studied, paying particular attention to their light curves from NASA's Kepler mission. This Letter aims to assess their evolutionary status, derive their rotation and ages, and identify those which are solar analogs or solar twin candidates. We separate out the subgiants that compose a large fraction of the asteroseismic sample, and which show an increase in the average rotation period as the stars ascend the subgiant branch. The rotation periods of the dwarfs, ranging from 6 to 30 days and averaging 19 days, allow us to assess their individual evolutionary states on the main sequence and to derive their ages using gyrochronology. These ages are found to be in agreement with a correlation coefficient of r = 0.79 with independent asteroseismic ages, where available. As a result of this investigation, we are able to identify 34 stars as solar analogs and 22 of them as solar twin candidates.

Enhancing the Frequency Adaptability of Periodic Current Controllers with a Fixed Sampling Rate for Grid-Connected Power Converters

DEFF Research Database (Denmark)

Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede

2016-01-01

Grid-connected power converters should employ advanced current controllers, e.g., Proportional Resonant (PR) and Repetitive Controllers (RC), in order to produce high-quality feed-in currents that are required to be synchronized with the grid. The synchronization is actually to detect...... of the resonant controllers and by approximating the fractional delay using a Lagrange interpolating polynomial for the RC, respectively, the frequency-variation-immunity of these periodic current controllers with a fixed sampling rate is improved. Experiments on a single-phase grid-connected system are presented...... the instantaneous grid information (e.g., frequency and phase of the grid voltage) for the current control, which is commonly performed by a Phase-Locked-Loop (PLL) system. Hence, harmonics and deviations in the estimated frequency by the PLL could lead to current tracking performance degradation, especially...

Periodontal diseases at the transition from the late antique to the early mediaeval period in Croatia.

Science.gov (United States)

Vodanović, Marin; Peroš, Kristina; Zukanović, Amila; Knežević, Marjana; Novak, Mario; Slaus, Mario; Brkić, Hrvoje

2012-10-01

We tested the hypothesis that the transition from the late antique to the early mediaeval period in Croatia had a negative impact on the periodontal health. 1118 skulls were examined for dental calculus, alveolar bone resorption, fenestrations, dehiscences and root furcation involvement. The prevalence of teeth with calculus varied from 40.7% in the LA sample of continental parts of Croatia to 50.3% in the LA sample of Adriatic Croatia. The prevalence of alveolar bone resorption ranged between 21.2% in the EM sample from continental Croatia and 32.3% in the LA sample from Adriatic Croatia. The prevalence of individuals with alveolar bone dehiscences varied from 8.6% in the LA sample from continental Croatia up to 15.0% in the EM sample from Adriatic Croatia. The prevalence of individuals with alveolar bone fenestrations varied from 21.5% in the LA sample from Adriatic Croatia up to 36.2% in the LA sample from continental Croatia. The prevalence of individuals with exposed root bifurcations or trifurcations varied from 9.0% in the EM sample from Adriatic Croatia up to 20.7% in the EM sample from continental Croatia. Statistically significant differences were found between samples. The transition from the late antique to the early mediaeval period in Croatia did not have a negative impact on periodontal health. Studies of periodontal health of ancient populations should be performed to provide a better and more reliable reconstruction of living conditions in the past. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hot sample archiving. Revision 3

International Nuclear Information System (INIS)

McVey, C.B.

1995-01-01

This Engineering Study revision evaluated the alternatives to provide tank waste characterization analytical samples for a time period as recommended by the Tank Waste Remediation Systems Program. The recommendation of storing 40 ml segment samples for a period of approximately 18 months (6 months past the approval date of the Tank Characterization Report) and then composite the core segment material in 125 ml containers for a period of five years. The study considers storage at 222-S facility. It was determined that the critical storage problem was in the hot cell area. The 40 ml sample container has enough material for approximately 3 times the required amount for a complete laboratory re-analysis. The final result is that 222-S can meet the sample archive storage requirements. During the 100% capture rate the capacity is exceeded in the hot cell area, but quick, inexpensive options are available to meet the requirements

Populations and home range relationships of the box turtle, Terrapene carolina (Linnaeus)

Science.gov (United States)

Stickel, L.F.

1949-01-01

A population study of Terrapene carolina (Linnaeus) was made at the Patuxent Research Refuge, Maryland, from 1944 to 1947. A thirty acre area in bottomland forest was selected for intensive study. Turtles were marked by filing notches in marginal scutes according to a code. Turtles make extensive use of brushy shelter during the day as well.as at night. Gully banks and woods openings are used for sunning. Nights are usually spent in a 'form,' constructed by the turtle in leaves, debris, or earth. A form may be used once or it may be used repeatedly by the same or different turtles. Weather conditions most favorable to turtle activity are high humidity, warm sunny days, and frequent rains. Periods of activity are alternated with periods of quiet, even in favorable weather. There is no evidence for territorialism. Ranges of turtles of all ages and both sexes overlap grossly. Turtles are frequently found near each other but no antagonistic behavior has been observed. Adult turtles occupy specific home ranges which they maintain from year to year. Turtles retained their ranges even though a flood that completely covered the study area. Maximum home range diameters were determined by measurements of the mapped ranges of individual turtles. There was no significant difference between sizes of male and female ranges: males 33O+ 26 feet, females 37O+29 feet. A trail-laying device was used in following travel routes for 456 turtle days. Normal movements within the home range are characterized by (1) turns, doublings, detours, and criss-crossing paths, (2) interspersion of fairly direct traverses of the home range, (3) frequently repeated travels over certain routes. Maximum limits of the home range are ordinarily reached within a few days or weeks, although some turtles cover only one portion of the range at a time. Some turtles have two home ranges. One of these turtles was followed with a trailer for 161 days in 1946 and 1947. Trips outside the home range are made by

Optimal sampling strategies for detecting zoonotic disease epidemics.

Directory of Open Access Journals (Sweden)

Jake M Ferguson

2014-06-01

Full Text Available The early detection of disease epidemics reduces the chance of successful introductions into new locales, minimizes the number of infections, and reduces the financial impact. We develop a framework to determine the optimal sampling strategy for disease detection in zoonotic host-vector epidemiological systems when a disease goes from below detectable levels to an epidemic. We find that if the time of disease introduction is known then the optimal sampling strategy can switch abruptly between sampling only from the vector population to sampling only from the host population. We also construct time-independent optimal sampling strategies when conducting periodic sampling that can involve sampling both the host and the vector populations simultaneously. Both time-dependent and -independent solutions can be useful for sampling design, depending on whether the time of introduction of the disease is known or not. We illustrate the approach with West Nile virus, a globally-spreading zoonotic arbovirus. Though our analytical results are based on a linearization of the dynamical systems, the sampling rules appear robust over a wide range of parameter space when compared to nonlinear simulation models. Our results suggest some simple rules that can be used by practitioners when developing surveillance programs. These rules require knowledge of transition rates between epidemiological compartments, which population was initially infected, and of the cost per sample for serological tests.

Optimal sampling strategies for detecting zoonotic disease epidemics.

Science.gov (United States)

Ferguson, Jake M; Langebrake, Jessica B; Cannataro, Vincent L; Garcia, Andres J; Hamman, Elizabeth A; Martcheva, Maia; Osenberg, Craig W

2014-06-01

The early detection of disease epidemics reduces the chance of successful introductions into new locales, minimizes the number of infections, and reduces the financial impact. We develop a framework to determine the optimal sampling strategy for disease detection in zoonotic host-vector epidemiological systems when a disease goes from below detectable levels to an epidemic. We find that if the time of disease introduction is known then the optimal sampling strategy can switch abruptly between sampling only from the vector population to sampling only from the host population. We also construct time-independent optimal sampling strategies when conducting periodic sampling that can involve sampling both the host and the vector populations simultaneously. Both time-dependent and -independent solutions can be useful for sampling design, depending on whether the time of introduction of the disease is known or not. We illustrate the approach with West Nile virus, a globally-spreading zoonotic arbovirus. Though our analytical results are based on a linearization of the dynamical systems, the sampling rules appear robust over a wide range of parameter space when compared to nonlinear simulation models. Our results suggest some simple rules that can be used by practitioners when developing surveillance programs. These rules require knowledge of transition rates between epidemiological compartments, which population was initially infected, and of the cost per sample for serological tests.

Intratypic differentiation of polioviruses isolated from suspected cases of poliomyelitis in Brazil during the period of 1990 to 1993

Directory of Open Access Journals (Sweden)

A. M. B. de Filippis

1994-12-01

Full Text Available This study analyzed 3129 fecal samples derived from 1626 patients with sudden onset acute flaccid paralysis clinically compatible with poliomyelitis. The samples were collected in the period ranging from January 1990 to September 1993 in all regions of Brazil. Among the 1626 cases studied, 196 had isolation of poliovirus. Nevertheless, it was observed that some factors influenced the isolation rate and the intratypic characterization of these polioviruses. No cases of acute flaccid paralysis has been found to be etiologically related with wild polioviruses.

Periodic Recurrence Patterns In X-Ray Solar Flare Appearances

Science.gov (United States)

Gyenge, N.; Erdélyi, R.

2018-06-01

The temporal recurrence of micro-flare events is studied for a time interval before and after of major solar flares. Our sample is based on the X-ray flare observations by the Geostationary Operational Environmental Satellite (GOES) and Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The analyzed data contain 1330/301 M-class and X-class GOES/RHESSI energetic solar flares and 4062/4119 GOES/RHESSI micro-flares covering the period elapse since 2002. The temporal analysis of recurrence, by Fast Fourier Transform, of the micro-flares, shows multiple significant periods. Based on the GOES and RHESSI data, the temporal analysis also demonstrates that multiple periods manifest simultaneously in both statistical samples without any significant shift over time. In the GOES sample, the detected significant periods are: 11.33, 5.61, 3.75, 2.80, and 2.24 minutes. The RHESSI data show similar significant periods at 8.54, 5.28, 3.66, 2.88, and 2.19 minutes. The periods are interpreted as signatures of standing oscillations, with the longest period (P 1) being the fundamental and others being higher harmonic modes. The period ratio of the fundamental and higher harmonics (P 1/P N ) is also analyzed. The standing modes may be signatures of global oscillations of the entire solar atmosphere encompassing magnetized plasma from the photosphere to the corona in active regions.

Slow-light dynamics in nonlinear periodic waveguides couplers

DEFF Research Database (Denmark)

Sukhorukov, A.A.; Ha, S.; Powell, D.A.

2009-01-01

We predict pulse switching and reshaping through nonlinear mixing of two slow-light states with different phase velocities in the same frequency range, and report on the first experimental observation of slow-light tunneling between coupled periodic waveguides.......We predict pulse switching and reshaping through nonlinear mixing of two slow-light states with different phase velocities in the same frequency range, and report on the first experimental observation of slow-light tunneling between coupled periodic waveguides....

Fluctuation microscopy: a probe of medium range order

International Nuclear Information System (INIS)

Treacy, M M J; Gibson, J M; Fan, L; Paterson, D J; McNulty, I

2005-01-01

Fluctuation microscopy is a hybrid diffraction-imaging technique that detects medium range order in amorphous materials by examining spatial fluctuations in coherent scattering. These fluctuations appear as speckle in images and diffraction patterns. The volume of material contributing to the speckle is determined by the point-spread function (the resolution) of the imaging optics and the sample thickness. The spatial periodicities being probed are related to the diffraction vector. Statistical analysis of the speckle allows the random and non-random (ordered) contributions to be discriminated. The image resolution that gives the maximum speckle contrast, as determined by the normalized variance of the image intensity, is determined by the characteristic length scale of the ordering. Because medium range ordering length scales can extend out to about the tenth coordination shell, fluctuation microscopy tends to be a low image resolution technique. This review presents the kinematical scattering theory underpinning fluctuation microscopy and a description of fluctuation electron microscopy as it has been employed in the transmission electron microscope for studying amorphous materials. Recent results using soft x-rays for studying nanoscale materials are also presented. We summarize outstanding issues and point to possible future directions for fluctuation microscopy as a technique

Adult Hematology and Clinical Chemistry Laboratory Reference Ranges in a Zimbabwean Population.

Directory of Open Access Journals (Sweden)

Wadzanai P Samaneka

Full Text Available Laboratory reference ranges used for clinical care and clinical trials in various laboratories in Zimbabwe were derived from textbooks and research studies conducted more than ten years ago. Periodic verification of these ranges is essential to track changes over time. The purpose of this study was to establish hematology and chemistry laboratory reference ranges using more rigorous methods.A community-based cross-sectional study was carried out in Harare, Chitungwiza, and Mutoko. A multistage sampling technique was used. Samples were transported from the field for analysis at the ISO15189 certified University of Zimbabwe-University of California San Francisco Central Research Laboratory. Hematology and clinical chemistry reference ranges lower and upper reference limits were estimated at the 2.5th and 97.5th percentiles respectively.A total of 769 adults (54% males aged 18 to 55 years were included in the analysis. Median age was 28 [IQR: 23-35] years. Males had significantly higher red cell counts, hemoglobin, hematocrit, and mean corpuscular hemoglobin compared to females. Females had higher white cell counts, platelets, absolute neutrophil counts, and absolute lymphocyte counts compared to males. There were no gender differences in eosinophils, monocytes, and absolute basophil count. Males had significantly higher levels of urea, sodium, potassium, calcium, creatinine, amylase, total protein, albumin and liver enzymes levels compared to females. Females had higher cholesterol and lipase compared with males. There are notable differences in the white cell counts, neutrophils, cholesterol, and creatinine kinase when compared with the currently used reference ranges.Data from this study provides new country specific reference ranges which should be immediately adopted for routine clinical care and accurate monitoring of adverse events in research studies.

Ranging Behaviour of Commercial Free-Range Laying Hens

Directory of Open Access Journals (Sweden)

Leonard Ikenna Chielo

2016-04-01

Full Text Available In this study, the range use and behaviour of laying hens in commercial free-range flocks was explored. Six flocks were each visited on four separate days and data collected from their outdoor area (divided into zones based on distance from shed and available resources. These were: apron (0–10 m from shed normally without cover or other enrichments; enriched belt (10–50 m from shed where resources such as manmade cover, saplings and dust baths were provided; and outer range (beyond 50 m from shed with no cover and mainly grass pasture. Data collection consisted of counting the number of hens in each zone and recording behaviour, feather condition and nearest neighbour distance (NND of 20 birds per zone on each visit day. In addition, we used techniques derived from ecological surveys to establish four transects perpendicular to the shed, running through the apron, enriched belt and outer range. Number of hens in each 10 m × 10 m quadrat was recorded four times per day as was the temperature and relative humidity of the outer range. On average, 12.5% of hens were found outside. Of these, 5.4% were found in the apron; 4.3% in the enriched zone; and 2.8% were in the outer range. This pattern was supported by data from quadrats, where the density of hens sharply dropped with increasing distance from shed. Consequently, NND was greatest in the outer range, least in the apron and intermediate in the enriched belt. Hens sampled in outer range and enriched belts had better feather condition than those from the apron. Standing, ground pecking, walking and foraging were the most commonly recorded activities with standing and pecking most likely to occur in the apron, and walking and foraging more common in the outer range. Use of the outer range declined with lower temperatures and increasing relative humidity, though use of apron and enriched belt was not affected by variation in these measures. These data support previous findings that outer range

Complementary periodic diffracting metallic nanohole and nanodipole arrays in the mid-infrared range

Science.gov (United States)

Ye, Yong-Hong; Zhang, Jia-Yu; Feng Ma, Hui; Yao, Jie; Wang, Xudong

2012-10-01

Metallic nanohole arrays and metallic nanodipole arrays are fabricated and experimentally characterized. A complementary response is observed in both transmission and reflection. For the metallic nanohole arrays, a peak (dip) in transmission (reflection) is observed at resonance whereas the metallic nanodipole arrays display a dip (peak) in transmission (reflection). The resonant frequency of both the metallic nanohole arrays and the nanodipole arrays depends on the dipole arm length, the incident angle, and the period. The resonant position of the nanohole arrays matches that of its complement, which means that Babinet's principle nearly holds for these structures in the mid-infrared region.

Volume higher; spot price ranges widen

International Nuclear Information System (INIS)

Anon.

1994-01-01

This article is the October 1994 uranium market summary. During this reporting period, volume on the spot concentrates market doubled. Twelve deals took place: three in the spot concentrates market, one in the medium and long-term market, four in the conversion market, and four in the enrichment market. The restricted price range widened due to higher prices at the top end of the range, while the unrestricted price range widened because of lower prices at the bottom end. Spot conversion prices were higher, and enrichment prices were unchanged

Real space method of powder diffraction for non-periodic and nearly periodic materials

International Nuclear Information System (INIS)

Egami, T.; Toby, B.H.; Dmowski, W.; Janot, C.; Jorgensen, J.D.

1990-01-01

The use of high-energy neutrons from pulsed or hot sources allows the method of atomic pair distribution analysis to be applied to the structural determination of crystalline as well as amorphous solids. This method complements the standard crystallographic methods in studying non-periodic aspects of solids with or without long range order

The Properties of Long Period Variables in the LMC from MACHO

Energy Technology Data Exchange (ETDEWEB)

Fraser, O J; Hawley, S L; Cook, K H

2008-05-06

We present a new analysis of the long period variables in the Large Magellanic Cloud from the MACHO Variable Star Catalog. Three-quarters of our sample of evolved, variable stars have periodic light curves. We characterize the stars in our sample using the multiple periods found in their frequency spectra. Additionally, we use single-epoch 2MASS measurements to construct the average infrared light curves for different groups of these stars. Comparison with evolutionary models shows that stars on the RGB or the Early AGB often show non-periodic variability, but begin to pulsate with periods on the two shortest period-luminosity sequences (1 & 2) when they brighten to K{sub s} {approx} 13. The stars on the Thermally Pulsing AGB are more likely to pulsate with longer periods that lie on the next two P-L sequences (3 & 4), including the sequence associated with the Miras in the LMC. The Petersen diagram and its variants show that multi-periodic stars on each pair of these sequences (3 & 4, and 1 & 2), typically pulsate with periods associated only with that pair. The periods in these multi-periodic stars become longer and stronger as the star evolves. We further constrain the mechanism behind the long secondary periods (LSPs) seen in half of our sample, and find that there is a close match between the luminosity functions of the LSP stars and all of the stars in our sample, and that these star's pulsation amplitudes are relatively wavelength independent. Although this is characteristic of stellar multiplicity, the large number of these variables is problematic for that explanation.

Quantitative Analysis of Range Image Patches by NEB Method

Directory of Open Access Journals (Sweden)

Wang Wen

2017-01-01

Full Text Available In this paper we analyze sampled high dimensional data with the NEB method from a range image database. Select a large random sample of log-valued, high contrast, normalized, 8×8 range image patches from the Brown database. We make a density estimator and we establish 1-dimensional cell complexes from the range image patch data. We find topological properties of 8×8 range image patches, prove that there exist two types of subsets of 8×8 range image patches modelled as a circle.

Microbiological quality of air in free-range and box-stall stable horse keeping systems.

Science.gov (United States)

Wolny-Koładka, Katarzyna

2018-04-07

The aim of this study was to assess the microbiological quality of air in three horse riding centers differing in the horse keeping systems. The air samples were collected in one facility with free-range horse keeping system and two with box stalls of different sizes. The samples were collected over a period of 3 years (2015-2017), four times per year (spring, summer, autumn, winter) to assess the effect of seasonal changes. The prevalence of aerobic mesophilic bacteria, mold fungi, actinomycetes, Staphylococcus spp., and Escherichia coli was determined by the air collision method on Petri dishes with appropriate microbiological media. At the same time, air temperature, relative humidity, and particulate matter concentration (PM 10 , PM 2.5 ) were measured. It was found that the horse keeping system affects the occurrence of the examined airborne microorganisms. Over the 3-year period of study, higher temperature and humidity, as well as particulate matter concentration-which notoriously exceeded limit values-were observed in the facilities with the box-stall system. The air sampled from the largest horse riding center, with the largest number of horses and the box-stall system of horse keeping, was also characterized by the heaviest microbiological contamination. Among others, bacteria from the following genera: Staphylococcus spp., Streptococcus spp., Bacillus spp., and E. coli and fungi from the genera Aspergillus, Fusarium, Mucor, Rhizopus, Penicillium, Trichothecium, Cladosporium, and Alternaria were identified in the analyzed samples.

Standardization of proton-induced x-ray emission technique for analysis of thick samples

Science.gov (United States)

Ali, Shad; Zeb, Johar; Ahad, Abdul; Ahmad, Ishfaq; Haneef, M.; Akbar, Jehan

2015-09-01

This paper describes the standardization of the proton-induced x-ray emission (PIXE) technique for finding the elemental composition of thick samples. For the standardization, three different samples of standard reference materials (SRMs) were analyzed using this technique and the data were compared with the already known data of these certified SRMs. These samples were selected in order to cover the maximum range of elements in the periodic table. Each sample was irradiated for three different values of collected beam charges at three different times. A proton beam of 2.57 MeV obtained using 5UDH-II Pelletron accelerator was used for excitation of x-rays from the sample. The acquired experimental data were analyzed using the GUPIXWIN software. The results show that the SRM data and the data obtained using the PIXE technique are in good agreement.

Periodicity in extinction and the problem of catastrophism in the history of life

Science.gov (United States)

Sepkoski, J. J. Jr; Sepkoski JJ, J. r. (Principal Investigator)

1989-01-01

The hypothesis that extinction events have recurred periodically over the last quarter billion years is greatly strengthened by new data on the stratigraphic ranges of marine animal genera. In the interval from the Permian to Recent, these data encompass some 13,000 generic extinctions, providing a more sensitive indicator of species-level extinctions than previously used familial data. Extinction time series computed from the generic data display nine strong peaks that are nearly uniformly spaced at 26 Ma intervals over the last 270 Ma. Most of these peaks correspond to extinction events recognized in more detailed, if limited, biostratigraphic studies. These new data weaken or negate most arguments against periodicity, which have involved criticisms of the taxonomic data base, sampling intervals, chronometric time scales, and statistical methods used in previous analyses. The criticisms are reviewed in some detail and various new calculations and simulations, including one assessing the effects of paraphyletic taxa, are presented. Although the new data strengthen the case for periodicity, they offer little new insight into the deriving mechanism behind the pattern. However, they do suggest that many of the periodic events may not have been catastrophic, occurring instead over several stratigraphic stages or substages.

Long-period and short-period variations of ionospheric parameters studied from complex observations performed on Cuba

Energy Technology Data Exchange (ETDEWEB)

Laso, B; Lobachevskii, L A; Potapova, N I; Freizon, I A; Shapiro, B S

1980-09-01

Cuban data from 1978 are used to study long-period (i.e., diurnal) variations of Doppler shift on a 3000 km path at frequencies of 10 and 15 MHz these variations are related to variations of parameters on the ionospheric path. Short-period variations were also studied on the basis of Doppler shift data and vertical sounding data in the 0.000111-0.00113 Hz frequency range. The relation between the observed variations and internal gravity waves are discussed.

A highly specific test for periodicity

International Nuclear Information System (INIS)

Ansmann, Gerrit

2015-01-01

We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely, that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic time-continuous dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincaré sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its runtime grows asymptotically linear with the length of the time series

A highly specific test for periodicity

Energy Technology Data Exchange (ETDEWEB)

Ansmann, Gerrit, E-mail: gansmann@uni-bonn.de [Department of Epileptology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Helmholtz Institute for Radiation and Nuclear Physics, University of Bonn, Nussallee 14–16, 53115 Bonn (Germany); Interdisciplinary Center for Complex Systems, University of Bonn, Brühler Straße 7, 53175 Bonn (Germany)

2015-11-15

We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely, that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic time-continuous dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincaré sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its runtime grows asymptotically linear with the length of the time series.

Real-time method of powder diffraction for non-periodic and nearly periodic materials

International Nuclear Information System (INIS)

Egami, T.; Toby, B.H.; Dmowski, T.W.; Jorgensen, J.D.

1989-12-01

The use of high-energy neutrons from pulsed or hot sources allows the method of atomic pair distribution analysis to be applied to the structural determination of crystalline as well as amorphous solids. This method complements the standard crystallographic methods in studying non-periodic aspects of solids with or without long range order. 14 refs., 3 figs

Ranging Behaviour of Commercial Free-Range Broiler Chickens 1: Factors Related to Flock Variability.

Science.gov (United States)

Taylor, Peta S; Hemsworth, Paul H; Groves, Peter J; Gebhardt-Henrich, Sabine G; Rault, Jean-Loup

2017-07-20

Little is known about the ranging behaviour of chickens. Understanding ranging behaviour is required to improve management and shed and range design to ensure optimal ranging opportunities. Using Radio Frequency Identification technology, we tracked 300 individual broiler chickens in each of four mixed sex ROSS 308 flocks on one commercial farm across two seasons. Ranging behaviour was tracked from the first day of range access (21 days of age) until 35 days of age in winter and 44 days of age in summer. Range use was higher than previously reported from scan sampling studies. More chickens accessed the range in summer (81%) than winter (32%; p range use was greater in summer flocks (4.4 ± 0.1 visits for a total of 26.3 ± 0.8 min/day) than winter flocks (3.2 ± 0.2 visits for a total of 7.9 ± 1.0 min/day). Seasonal differences were only marginally explained by weather conditions and may reflect the reduction in range exposure between seasons (number of days, hours per day, and time of day). Specific times of the day ( p ranging and external factors that may explain ranging preferences.

Blubber cortisol: a potential tool for assessing stress response in free-ranging dolphins without effects due to sampling.

Directory of Open Access Journals (Sweden)

Nicholas M Kellar

Full Text Available When paired with dart biopsying, quantifying cortisol in blubber tissue may provide an index of relative stress levels (i.e., activation of the hypothalamus-pituitary-adrenal axis in free-ranging cetacean populations while minimizing the effects of the act of sampling. To validate this approach, cortisol was extracted from blubber samples collected from beach-stranded and bycaught short-beaked common dolphins using a modified blubber steroid isolation technique and measured via commercially available enzyme immunoassays. The measurements exhibited appropriate quality characteristics when analyzed via a bootstraped stepwise parallelism analysis (observed/expected = 1.03, 95%CI: 99.6 - 1.08 and showed no evidence of matrix interference with increasing sample size across typical biopsy tissue masses (75-150 mg; r(2 = 0.012, p = 0.78, slope = 0.022 ng(cortisol deviation/ul(tissue extract added. The relationships between blubber cortisol and eight potential cofactors namely, 1 fatality type (e.g., stranded or bycaught, 2 specimen condition (state of decomposition, 3 total body length, 4 sex, 5 sexual maturity state, 6 pregnancy status, 7 lactation state, and 8 adrenal mass, were assessed using a Bayesian generalized linear model averaging technique. Fatality type was the only factor correlated with blubber cortisol, and the magnitude of the effect size was substantial: beach-stranded individuals had on average 6.1-fold higher cortisol levels than those of bycaught individuals. Because of the difference in conditions surrounding these two fatality types, we interpret this relationship as evidence that blubber cortisol is indicative of stress response. We found no evidence of seasonal variation or a relationship between cortisol and the remaining cofactors.

Distribution of Parasites Detected in Stool Samples of Patients Admitted to Our Parasitology Laboratory during a Three-Year Period between 2012 and 2014.

Science.gov (United States)

Selek, Mehmet Burak; Bektöre, Bayhan; Karagöz, Ergenekon; Baylan, Orhan; Özyurt, Mustafa

2016-09-01

Parasitic diseases are among the major public health issues worldwide. A number of tests are available for diagnosis, but the sentivity and specifity of these tests are assumed to be insufficient. Nevertheless, the most common diagnostic method is microscopic examination. In this study, we aimed to introduce the distribution of parasites detected in stool samples of patients admitted to our laboratory on the basis of parameters such as, age, and gender during a 3-year period between 2012 and 2014. In total, 6757 stool samples were included in the study. After macroscopic examination, wet mounts of all samples were examined under a light microscope using ×100 and ×400 magnification lenses. Wet mounts were prepared with physiological saline and Lugol's iodine. Parasites were detected in 3.7% (252) of the samples, while no parasites were detected in 96.3% (6505) of the samples. The distribution of intestinal parasites was as follows: Blastocystis hominis (63.5%), Giardia intestinalis (26.2%), Taenia sp. (4.8%), Enterobius vermicularis (2.4%), Entamoeba histolytica/dispar (1.6%), and Hymenolepis nana (1.6%). When the burden of intestinal parasites on public health is considered, they are still a major health issue in Turkey. The frequency of parasitic diseases can be reduced by the education of individuals and implementation of effective diagnostic methods, treatments, and preventive measures.

Atmospheric and surface water pollution interpretation in the Gdansk beltway impact range by the use of multivariate analysis

Energy Technology Data Exchange (ETDEWEB)

Dubiella-Jackowska, Aleksandra; Polkowska, Zaneta; Kudlak, Blazej; Namiesnik, Jacek [Chemical Faculty, Department of Analytical Chemistry, Gdansk University of Technology, Gdansk (Poland); Astel, Aleksander [Environmental Chemistry Research Unit, Institute of Biology and Environmental Protection, Pomeranian Academy, Slupsk (Poland); Staszek, Wojciech [Faculty of Physical Geography and Environmental Management, University of Gdansk, Gdansk (Poland)

2010-09-15

The present study deals with the application of the hierarchical cluster analysis and non-parametric tests in order to interpret the Gdansk Beltway impact range. The data set represents concentration values for major inorganic ions (Na{sup +}, NH{sub 4}{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, F{sup -}, Cl{sup -}, NO{sub 3}{sup -}, and SO{sub 4}{sup 2-}) as well as electrolytic conductivity and pH measured in various water samples [precipitation, throughfall water, road runoff, and surface water (drainage ditches, surface water reservoirs, and spring water)] collected in the vicinity of the beltway. Several similarity groups were discovered both in the objects and in the variables modes according to the water sample. In the majority of cases clear anthropogenic (fertilizers usage and transport, road salting in winter) and semi-natural (sea salt aerosols, erosion of construction materials) impacts were discovered. Spatial variation was discovered for road runoff samples and samples collected from surface water reservoirs and springs. Surprisingly no clear seasonal variability was discovered for precipitation chemistry, while some evidences for existing of summer and winter specific chemical profile was discovered for road runoff samples. In general, limited range of the Gdansk Beltway impact was proven. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Transient periodic x-ray source in Taurus, A0535+26

International Nuclear Information System (INIS)

Bradt, H.; Mayer, W.; Buff, J.; Clark, G.W.; Doxsey, R.; Hearn, D.; Jernigan, G.; Joss, P.C.; Laufer, B.; Lewin, W.; Li, F.; Matilsky, T.; McClintock, J.; Primini, F.; Rappaport, S.; Schnopper, H.

1976-01-01

Light curves of the 104 s periodicity in the transient X-ray source in Taurus (A0535+26) are presented for six energy intervals in the range 1-35 keV for the period 1975 May 30-June 2. The pulse structure ranges from an apparently simple modulation at higher energies to a very complex pattern at lower energies. No Doppler shift is observed in the 104 s pulse period during the three days of observations. This places severe constraints upon possible binary orbital motion. Upper limits on the power at other periodicities are approximately-less-than10 percent for 2 ms-2s and approximately-less-than2 percent for 2 s-2000 s

Sampling free energy surfaces as slices by combining umbrella sampling and metadynamics.

Science.gov (United States)

Awasthi, Shalini; Kapil, Venkat; Nair, Nisanth N

2016-06-15

Metadynamics (MTD) is a very powerful technique to sample high-dimensional free energy landscapes, and due to its self-guiding property, the method has been successful in studying complex reactions and conformational changes. MTD sampling is based on filling the free energy basins by biasing potentials and thus for cases with flat, broad, and unbound free energy wells, the computational time to sample them becomes very large. To alleviate this problem, we combine the standard Umbrella Sampling (US) technique with MTD to sample orthogonal collective variables (CVs) in a simultaneous way. Within this scheme, we construct the equilibrium distribution of CVs from biased distributions obtained from independent MTD simulations with umbrella potentials. Reweighting is carried out by a procedure that combines US reweighting and Tiwary-Parrinello MTD reweighting within the Weighted Histogram Analysis Method (WHAM). The approach is ideal for a controlled sampling of a CV in a MTD simulation, making it computationally efficient in sampling flat, broad, and unbound free energy surfaces. This technique also allows for a distributed sampling of a high-dimensional free energy surface, further increasing the computational efficiency in sampling. We demonstrate the application of this technique in sampling high-dimensional surface for various chemical reactions using ab initio and QM/MM hybrid molecular dynamics simulations. Further, to carry out MTD bias reweighting for computing forward reaction barriers in ab initio or QM/MM simulations, we propose a computationally affordable approach that does not require recrossing trajectories. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

77 FR 73452 - Grace Period Study

Science.gov (United States)

2012-12-10

... survey may be distributed in waves for convenience. The Grace Period Study survey will be an electronic... information that is used for sampling purposes will be maintained in a separate file from the quantitative...

Validated sampling strategy for assessing contaminants in soil stockpiles

International Nuclear Information System (INIS)

Lame, Frank; Honders, Ton; Derksen, Giljam; Gadella, Michiel

2005-01-01

Dutch legislation on the reuse of soil requires a sampling strategy to determine the degree of contamination. This sampling strategy was developed in three stages. Its main aim is to obtain a single analytical result, representative of the true mean concentration of the soil stockpile. The development process started with an investigation into how sample pre-treatment could be used to obtain representative results from composite samples of heterogeneous soil stockpiles. Combining a large number of random increments allows stockpile heterogeneity to be fully represented in the sample. The resulting pre-treatment method was then combined with a theoretical approach to determine the necessary number of increments per composite sample. At the second stage, the sampling strategy was evaluated using computerised models of contaminant heterogeneity in soil stockpiles. The now theoretically based sampling strategy was implemented by the Netherlands Centre for Soil Treatment in 1995. It was applied to all types of soil stockpiles, ranging from clean to heavily contaminated, over a period of four years. This resulted in a database containing the analytical results of 2570 soil stockpiles. At the final stage these results were used for a thorough validation of the sampling strategy. It was concluded that the model approach has indeed resulted in a sampling strategy that achieves analytical results representative of the mean concentration of soil stockpiles. - A sampling strategy that ensures analytical results representative of the mean concentration in soil stockpiles is presented and validated

Magnetic cycles and rotation periods of late-type stars from photometric time series

Science.gov (United States)

Suárez Mascareño, A.; Rebolo, R.; González Hernández, J. I.

2016-10-01

Aims: We investigate the photometric modulation induced by magnetic activity cycles and study the relationship between rotation period and activity cycle(s) in late-type (FGKM) stars. Methods: We analysed light curves, spanning up to nine years, of 125 nearby stars provided by the All Sky Automated Survey (ASAS). The sample is mainly composed of low-activity, main-sequence late-A to mid-M-type stars. We performed a search for short (days) and long-term (years) periodic variations in the photometry. We modelled the light curves with combinations of sinusoids to measure the properties of these periodic signals. To provide a better statistical interpretation of our results, we complement our new results with results from previous similar works. Results: We have been able to measure long-term photometric cycles of 47 stars, out of which 39 have been derived with false alarm probabilities (FAP) of less than 0.1 per cent. Rotational modulation was also detected and rotational periods were measured in 36 stars. For 28 stars we have simultaneous measurements of activity cycles and rotational periods, 17 of which are M-type stars. We measured both photometric amplitudes and periods from sinusoidal fits. The measured cycle periods range from 2 to 14 yr with photometric amplitudes in the range of 5-20 mmag. We found that the distribution of cycle lengths for the different spectral types is similar, as the mean cycle is 9.5 yr for F-type stars, 6.7 yr for G-type stars, 8.5 yr for K-type stars, 6.0 yr for early M-type stars, and 7.1 yr for mid-M-type stars. On the other hand, the distribution of rotation periods is completely different, trending to longer periods for later type stars, from a mean rotation of 8.6 days for F-type stars to 85.4 days in mid-M-type stars. The amplitudes induced by magnetic cycles and rotation show a clear correlation. A trend of photometric amplitudes with rotation period is also outlined in the data. The amplitudes of the photometric variability

Seismic isolation of two dimensional periodic foundations

International Nuclear Information System (INIS)

Yan, Y.; Mo, Y. L.; Laskar, A.; Cheng, Z.; Shi, Z.; Menq, F.; Tang, Y.

2014-01-01

Phononic crystal is now used to control acoustic waves. When the crystal goes to a larger scale, it is called periodic structure. The band gaps of the periodic structure can be reduced to range from 0.5 Hz to 50 Hz. Therefore, the periodic structure has potential applications in seismic wave reflection. In civil engineering, the periodic structure can be served as the foundation of upper structure. This type of foundation consisting of periodic structure is called periodic foundation. When the frequency of seismic waves falls into the band gaps of the periodic foundation, the seismic wave can be blocked. Field experiments of a scaled two dimensional (2D) periodic foundation with an upper structure were conducted to verify the band gap effects. Test results showed the 2D periodic foundation can effectively reduce the response of the upper structure for excitations with frequencies within the frequency band gaps. When the experimental and the finite element analysis results are compared, they agree well with each other, indicating that 2D periodic foundation is a feasible way of reducing seismic vibrations.

Prediction of Vibration Transmission within Periodic Bar Structures

DEFF Research Database (Denmark)

Domadiya, Parthkumar Gandalal; Andersen, Lars Vabbersgaard; Sorokin, Sergey

2012-01-01

The present analysis focuses on vibration transmission within semi-infinite bar structure. The bar is consisting of two different materials in a periodic manner. A periodic bar model is generated using two various methods: The Finite Element method (FEM) and a Floquet theory approach. A parameter...... study is carried out regarding the influence of the number of periods at various frequencies within a semi-infinite bar, stop bands are illustrated at certain periodic intervals within the structure. The computations are carried out in frequency domain in the range below 500 Hz. Results from both...

Optimization of sampling pattern and the design of Fourier ptychographic illuminator.

Science.gov (United States)

Guo, Kaikai; Dong, Siyuan; Nanda, Pariksheet; Zheng, Guoan

2015-03-09

Fourier ptychography (FP) is a recently developed imaging approach that facilitates high-resolution imaging beyond the cutoff frequency of the employed optics. In the original FP approach, a periodic LED array is used for sample illumination, and therefore, the scanning pattern is a uniform grid in the Fourier space. Such a uniform sampling scheme leads to 3 major problems for FP, namely: 1) it requires a large number of raw images, 2) it introduces the raster grid artefacts in the reconstruction process, and 3) it requires a high-dynamic-range detector. Here, we investigate scanning sequences and sampling patterns to optimize the FP approach. For most biological samples, signal energy is concentrated at low-frequency region, and as such, we can perform non-uniform Fourier sampling in FP by considering the signal structure. In contrast, conventional ptychography perform uniform sampling over the entire real space. To implement the non-uniform Fourier sampling scheme in FP, we have designed and built an illuminator using LEDs mounted on a 3D-printed plastic case. The advantages of this illuminator are threefold in that: 1) it reduces the number of image acquisitions by at least 50% (68 raw images versus 137 in the original FP setup), 2) it departs from the translational symmetry of sampling to solve the raster grid artifact problem, and 3) it reduces the dynamic range of the captured images 6 fold. The results reported in this paper significantly shortened acquisition time and improved quality of FP reconstructions. It may provide new insights for developing Fourier ptychographic imaging platforms and find important applications in digital pathology.

Establishment of gastro-intestinal helminth infections in free-range chickens: a longitudinal on farm study.

Science.gov (United States)

Wongrak, Kalyakorn; Daş, Gürbüz; Moors, Eva; Sohnrey, Birgit; Gauly, Matthias

2014-01-01

The objective of this study was to monitor establishment and development of gastro-intestinal helminth infections in chickens over two production years (PY) on a free-range farm in Lower Saxony, Germany. The data were collected between July 2010 and June 2011 (PY1) and July 2011 and January 2013 (PY2), respectively. During PY1, Lohmann Brown classic (LB classic, N = 450) was tested, while in PY2 two different genotypes (230 LB classic, 230 LB plus) were used. The hens were kept in two mobile stalls that were moved to a new position at regular intervals. In both PY1 and PY2, 20 individual faecal samples per stall were randomly collected at monthly intervals in order to calculate the number of internal parasite eggs per gram of faeces (EPG). At the end of the laying periods, approximately 10% (N = 42) or more than 50% (N = 265) of hens were subjected to post-mortem parasitological examinations in PY1 and PY2, respectively. No parasite eggs were found in the faecal samples during PY1, whereas almost all of the hens (97.6%) were infected with Heterakis gallinarum (36 worms/hen) at the end of the period. In PY2, nematode eggs in faeces were found from the third month onwards at a low level, increasing considerably towards the final three months. There was no significant difference between the two genotypes of brown hens neither for EPG (P = 0.456) or for overall prevalence (P = 0.177). Mortality rate ranged from 18.3 to 27.4% but did not differ significantly between genotypes or production years. Average worm burden was 207 worms/hen in PY2. The most prevalent species were H. gallinarum (98.5%) followed by Ascaridia galli (96.2%) and Capillaria spp. (86.1%). Furthermore, three Capillaria species, C. obsignata, C. bursata and C. caudinflata were differentiated. In conclusion chickens kept on free-range farms are exposed to high risks of nematode infections and have high mortality rates with no obvious link to parasite infections. Once the farm environment is contaminated

Note: A wide temperature range MOKE system with annealing capability.

Science.gov (United States)

Chahil, Narpinder Singh; Mankey, G J

2017-07-01

A novel sample stage integrated with a longitudinal MOKE system has been developed for wide temperature range measurements and annealing capabilities in the temperature range 65 K temperatures without adversely affecting the cryostat and minimizes thermal drift in position. In this system the hysteresis loops of magnetic samples can be measured simultaneously while annealing the sample in a magnetic field.

Respondent-Driven Sampling – Testing Assumptions: Sampling with Replacement

Directory of Open Access Journals (Sweden)

Barash Vladimir D.

2016-03-01

Full Text Available Classical Respondent-Driven Sampling (RDS estimators are based on a Markov Process model in which sampling occurs with replacement. Given that respondents generally cannot be interviewed more than once, this assumption is counterfactual. We join recent work by Gile and Handcock in exploring the implications of the sampling-with-replacement assumption for bias of RDS estimators. We differ from previous studies in examining a wider range of sampling fractions and in using not only simulations but also formal proofs. One key finding is that RDS estimates are surprisingly stable even in the presence of substantial sampling fractions. Our analyses show that the sampling-with-replacement assumption is a minor contributor to bias for sampling fractions under 40%, and bias is negligible for the 20% or smaller sampling fractions typical of field applications of RDS.

Time-Varying Periodicity in Intraday Volatility

DEFF Research Database (Denmark)

Andersen, Torben Gustav; Thyrsgaard, Martin; Todorov, Viktor

We develop a nonparametric test for deciding whether return volatility exhibits time-varying intraday periodicity using a long time-series of high-frequency data. Our null hypothesis, commonly adopted in work on volatility modeling, is that volatility follows a stationary process combined...... with a constant time-of-day periodic component. We first construct time-of-day volatility estimates and studentize the high-frequency returns with these periodic components. If the intraday volatility periodicity is invariant over time, then the distribution of the studentized returns should be identical across...... with estimating volatility moments through their sample counterparts. Critical values are computed via easy-to-implement simulation. In an empirical application to S&P 500 index returns, we find strong evidence for variation in the intraday volatility pattern driven in part by the current level of volatility...

Inferring probabilistic stellar rotation periods using Gaussian processes

Science.gov (United States)

Angus, Ruth; Morton, Timothy; Aigrain, Suzanne; Foreman-Mackey, Daniel; Rajpaul, Vinesh

2018-02-01

Variability in the light curves of spotted, rotating stars is often non-sinusoidal and quasi-periodic - spots move on the stellar surface and have finite lifetimes, causing stellar flux variations to slowly shift in phase. A strictly periodic sinusoid therefore cannot accurately model a rotationally modulated stellar light curve. Physical models of stellar surfaces have many drawbacks preventing effective inference, such as highly degenerate or high-dimensional parameter spaces. In this work, we test an appropriate effective model: a Gaussian Process with a quasi-periodic covariance kernel function. This highly flexible model allows sampling of the posterior probability density function of the periodic parameter, marginalizing over the other kernel hyperparameters using a Markov Chain Monte Carlo approach. To test the effectiveness of this method, we infer rotation periods from 333 simulated stellar light curves, demonstrating that the Gaussian process method produces periods that are more accurate than both a sine-fitting periodogram and an autocorrelation function method. We also demonstrate that it works well on real data, by inferring rotation periods for 275 Kepler stars with previously measured periods. We provide a table of rotation periods for these and many more, altogether 1102 Kepler objects of interest, and their posterior probability density function samples. Because this method delivers posterior probability density functions, it will enable hierarchical studies involving stellar rotation, particularly those involving population modelling, such as inferring stellar ages, obliquities in exoplanet systems, or characterizing star-planet interactions. The code used to implement this method is available online.

Hematology and serum chemistry reference ranges of free-ranging moose (Alces alces) in Norway.

Science.gov (United States)

Rostal, Melinda K; Evans, Alina L; Solberg, Erling J; Arnemo, Jon M

2012-07-01

Baseline reference ranges of serum chemistry and hematology data can be important indicators for the status of both individuals or populations of wild animals that are affected by emerging pathogens, toxicants, or other causes of disease. Frequently, reference ranges for these values are not available for wildlife species or subspecies. We present hematologic and serum chemistry reference ranges for moose (Alces alces) adults, yearlings, and calves in Norway sampled from 1992-2000. Additionally, we demonstrated that both induction time and chase time were correlated with initial rectal temperature, although they were not significantly correlated with cortisol, aspartate aminotransferase, glucose, or creatine kinase. Overall, the reference ranges given here are similar to those given for American moose, with a few differences that can be attributed to environment, testing methodology, or subspecies or species status. This is the first report, to our knowledge, of reference ranges for moose in Norway.

Dielectric characterization of materials at microwave frequency range

Directory of Open Access Journals (Sweden)

J. de los Santos

2003-01-01

Full Text Available In this study a coaxial line was used to connect a microwave-frequency Network Analyzer and a base moving sample holder for dielectric characterization of ferroelectric materials in the microwave range. The main innovation of the technique is the introduction of a special sample holder that eliminates the air gap effect by pressing sample using a fine pressure system control. The device was preliminary tested with alumina (Al2O3 ceramics and validated up to 2 GHz. Dielectric measurements of lanthanum and manganese modified lead titanate (PLTM ceramics were carried out in order to evaluate the technique for a high permittivity material in the microwave range. Results showed that such method is very useful for materials with high dielectric permittivities, which is generally a limiting factor of other techniques in the frequency range from 50 MHz to 2 GHz.

Out-of-range international normalized ratio values and healthcare cost among new warfarin patients with non-valvular atrial fibrillation.

Science.gov (United States)

Nelson, Winnie W; Wang, Li; Baser, Onur; Damaraju, C V; Schein, Jeffrey R

2015-05-01

Patients with out-of-range international normalized ratio (INR) values 3.0 have been associated with increased risk of thromboembolic and bleeding events. INR monitoring is costly, because of associated physician and nurse time, laboratory resource use, and dose adjustments. This study assessed the healthcare cost burden associated with out-of-range INR among warfarin initiator patients diagnosed with non-valvular atrial fibrillation (NVAF) in the US Veterans Health Administration (VHA) population. Adult NVAF patients (≥18 years) initiating warfarin were selected from the VHA dataset for the study period October 1, 2007-September 30, 2012. Only valid INR measurements (0.5 ≤ INR ≤ 20) were examined for the follow-up period, from the index date (warfarin initiation date) until the end of warfarin exposure or death. All-cause healthcare costs within 30 days were measured starting from the second month (31 days post-index date) to the end of the study period. Costs for inpatient stays, emergency room, outpatient facility, physician office visits, and other services were computed separately. Multiple regression was performed using the generalized linear model for overall cost analysis. In total, 29,463 patients were included in the study sample. Mean costs for out-of-range INR ranged from $3419 to $5126. Inpatient, outpatient, outpatient pharmacy, and total costs were significantly higher after patients experienced out-of-range results (INR  3), compared with in-range INR (2 ≤ INR ≤ 3). When exposed to out-of-range INR, patients also incurred higher mean total costs within 2-6 months ($3840-$5820) than after the first 6 months ($2789-$3503) of warfarin therapy. In the VHA population, INR measures outside of the 2-3 range were associated with significantly higher healthcare costs. Increased costs were especially apparent when INR values were below 2, although INR measures above 3 were also associated with higher costs relative to in-range

Dynamics of Salmonella Shedding and Welfare of Hens in Free-Range Egg Production Systems

Science.gov (United States)

Gole, Vaibhav C.; Woodhouse, Rebecca; Caraguel, Charles; Moyle, Talia; Rault, Jean-Loup; Sexton, Margaret

2016-01-01

ABSTRACT The current study investigated the effect of environmental stressors (i.e., weather changes) on Salmonella shedding in free-range production systems and the correlations with behavioral and physiological measures (i.e., fecal glucocorticoid metabolites). This involved longitudinal and point-in-time surveys of Salmonella shedding and environmental contamination on four commercial free-range layer farms. The shedding of Salmonella was variable across free-range farms and in different seasons. There was no significant effect of season on the Salmonella prevalence during this investigation. In this study, the combined Salmonella most probable number (MPN) counts in environmental (including feces, egg belt, dust, nest box, and ramp) samples were highest in samples collected during the summer season (4th sampling, performed in February). The predominant serovars isolated during this study were Salmonella enterica serovar Mbandaka and Salmonella enterica serovar Typhimurium phage types 135 and 135a. These two phage types were involved in several egg product-related Salmonella outbreaks in humans. Multilocus variable-number tandem-repeat analysis (MLVA) results indicated that MLVA types detected from human food poisoning cases exhibited MLVA patterns similar to the strains isolated during this study. All Salmonella isolates (n = 209) were tested for 15 different genes involved in adhesion, invasion, and survival of Salmonella spp. We also observed variations for sopA, ironA, and misL. There were no positive correlations between fecal corticosterone metabolite (FCM) and Salmonella prevalence and/or shedding in feces. Also, there were no positive correlations between Salmonella prevalence and Salmonella count (log MPN) and any of the other welfare parameters. IMPORTANCE In this study, the welfare of laying hens and Salmonella shedding were compared over a prolonged period of time in field conditions. This study investigated the long-term shedding of Salmonella

Dynamics of Salmonella Shedding and Welfare of Hens in Free-Range Egg Production Systems.

Science.gov (United States)

Gole, Vaibhav C; Woodhouse, Rebecca; Caraguel, Charles; Moyle, Talia; Rault, Jean-Loup; Sexton, Margaret; Chousalkar, Kapil

2017-03-01

The current study investigated the effect of environmental stressors (i.e., weather changes) on Salmonella shedding in free-range production systems and the correlations with behavioral and physiological measures (i.e., fecal glucocorticoid metabolites). This involved longitudinal and point-in-time surveys of Salmonella shedding and environmental contamination on four commercial free-range layer farms. The shedding of Salmonella was variable across free-range farms and in different seasons. There was no significant effect of season on the Salmonella prevalence during this investigation. In this study, the combined Salmonella most probable number (MPN) counts in environmental (including feces, egg belt, dust, nest box, and ramp) samples were highest in samples collected during the summer season (4th sampling, performed in February). The predominant serovars isolated during this study were Salmonella enterica serovar Mbandaka and Salmonella enterica serovar Typhimurium phage types 135 and 135a. These two phage types were involved in several egg product-related Salmonella outbreaks in humans. Multilocus variable-number tandem-repeat analysis (MLVA) results indicated that MLVA types detected from human food poisoning cases exhibited MLVA patterns similar to the strains isolated during this study. All Salmonella isolates ( n = 209) were tested for 15 different genes involved in adhesion, invasion, and survival of Salmonella spp. We also observed variations for sopA , ironA , and misL There were no positive correlations between fecal corticosterone metabolite (FCM) and Salmonella prevalence and/or shedding in feces. Also, there were no positive correlations between Salmonella prevalence and Salmonella count (log MPN) and any of the other welfare parameters. IMPORTANCE In this study, the welfare of laying hens and Salmonella shedding were compared over a prolonged period of time in field conditions. This study investigated the long-term shedding of Salmonella serovars in

Periodic and secular changes in SS 433

International Nuclear Information System (INIS)

Collins, G.W.; Newsom, G.H.

1983-01-01

The recent history of SS 433 is reviewed with particular attention being given to the discovery of the periodic phenomena displayed by this object. Several periods ranging from days to months are established as being present in the spectrum of the ''moving'' lines as well as in other aspects of the emission from the object. In addition evidence for secular change in some of the defining parameters of the system is presented. Although these secular changes may eventually prove to be periodic on a rather long time scale, some interpretation of both the periodic and secular phenomena is possible. It is shown that it is possible to interpret all the known periodic phenomena in terms of a processing object responding to the time-varying torques that one would expect in a binary system

Relationships between processing delay and microbial load of broiler neck skin samples.

Science.gov (United States)

Lucianez, A; Holmes, M A; Tucker, A W

2010-01-01

The measurable microbial load on poultry carcasses during processing is determined by a number of factors including farm or origin, processing hygiene, and external temperature. This study investigated associations between carcass microbial load and progressive delays to processing. A total of 30 carcasses were delayed immediately after defeathering and before evisceration in a commercial abattoir in groups of five, and were held at ambient temperature for 1, 2, 3, 4, 6, and 8 h. Delayed carcasses were reintroduced to the processing line, and quantitative assessment of total viable count, coliforms, Staphylococcus aureus, and Pseudomonas spp. was undertaken on neck skin flap samples collected after carcass chilling and then pooled for each group. Sampling was repeated on 5 separate days, and the data were combined. Significant increases in total viable count (P = 0.001) and coliforms (P = 0.004), but not for S. aureus or Pseudomonas loads, were observed across the 8-h period of delay. In line with previous studies, there was significant variation in microbiological data according to sampling day. In conclusion, there is a significant and measurable decline in microbiological status of uneviscerated but defeathered poultry carcasses after an 8-h delay, but the variability of sampling results, reflecting the wide range of factors that impact microbial load, means that it is not possible to determine maximum or minimum acceptable periods of processing delay based on this criterion alone.

A comparison of geochemical exploration techniques and sample media within accretionary continental margins: an example from the Pacific Border Ranges, Southern Alaska, U.S.A.

Science.gov (United States)

Sutley, S.J.; Goldfarb, R.J.; O'Leary, R. M.; Tripp, R.B.

1990-01-01

The Pacific Border Ranges of the southern Alaskan Cordillera are composed of a number of allochthonous tectonostratigraphic terranes. Within these terranes are widespread volcanogenic, massive sulfide deposits in and adjacent to portions of accreted ophiolite complexes, bands and disseminations of chromite in accreted island-arc ultramafic rocks, and epigenetic, gold-bearing quartz veins in metamorphosed turbidite sequences. A geochemical pilot study was undertaken to determine the most efficient exploration strategy for locating these types of mineral deposits within the Pacific Border Ranges and other typical convergent continental margin environments. High-density sediment sampling was carried out in first- and second-order stream channels surrounding typical gold, chromite and massive sulfide occurrences. At each site, a stream-sediment and a panned-concentrate sample were collected. In the laboratory, the stream sediments were sieved into coarse-sand, fine- to medium-sand, and silt- to clay-size fractions prior to analysis. One split of the panned concentrates was retained for analysis; a second split was further concentrated by gravity separation in heavy liquids and then divided into magnetic, weakly magnetic and nonmagnetic fractions for analysis. A number of different techniques including atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry and semi-quantitative emission spectrography were used to analyze the various sample media. Comparison of the various types of sample media shows that in this tectonic environment it is most efficient to include a silt- to clay-size sediment fraction and a panned-concentrate sample. Even with the relatively low detection limits for many elements by plasma spectrometry and atomic absorption spectrometry, anomalies reflecting the presence of gold veins could not be identified in any of the stream-sediment fractions. Unseparated panned-concentrate samples should be analyzed by emission

Lineages that cheat death: surviving the squeeze on range size.

Science.gov (United States)

Waldron, Anthony

2010-08-01

Evolutionary lineages differ greatly in their net diversification rates, implying differences in rates of extinction and speciation. Lineages with a large average range size are commonly thought to have reduced extinction risk (although linking low extinction to high diversification has proved elusive). However, climate change cycles can dramatically reduce the geographic range size of even widespread species, and so most species may be periodically reduced to a few populations in small, isolated remnants of their range. This implies a high and synchronous extinction risk for the remaining populations, and so for the species as a whole. Species will only survive through these periods if their individual populations are "threat tolerant," somehow able to persist in spite of the high extinction risk. Threat tolerance is conceptually different from classic extinction resistance, and could theoretically have a stronger relationship with diversification rates than classic resistance. I demonstrate that relationship using primates as a model. I also show that narrowly distributed species have higher threat tolerance than widespread ones, confirming that tolerance is an unusual form of resistance. Extinction resistance may therefore operate by different rules during periods of adverse global environmental change than in more benign periods.

Radioactivity measurements of soil samples in the Republic of Serbia for the period 1999-2001

International Nuclear Information System (INIS)

Eremic Savkovic, M.; Pantelic, G.; Javorina, L.; Tanaskovic, I.; Vuletic, V.

2002-01-01

The soil is the basic environment of migration of radionuclides into plants, from which they reach the people and animals through food. The type of soil affects the distribution of radionuclides in the soil itself and their transfer into plants, respectively. Systemic testing of radioactivity of soils is performed on specific locations in the Federal Republic of Yugoslavia, in particular time periods according to methods defined by regulations. As result of NATO aggression and use of ammunition with depleted uranium in 1999, the existing radioactivity monitoring program of Yugoslavia was modified. Besides measurement of activity of artificial radionuclides, that were present in living environment after Chernobyl accident in 1986, the testing of activity of natural radionuclides, especially of uranium, was carried out as well. Uranium in Serbia derives from natural sources, considering the geological composition of rocks and geochemical composition of soil, and their concentrations as well as the concentrations of its descendants represent the significant component of natural sources of ionizing irradiation. In Serbia, the major uranium sources are igneous, carbonic and sedimentary rocks, and granite. According to perennial geological investigation of uranium in our country, several geological regions have been found to have uranium in higher or lower concentration. The uranium concentration in these regions ranged from 0.003g/t for ultra basic rocks to 3.5g/t for igneous, sedimentary rocks and granite. One of considerable uranium sources is specific technological procedure in industry such as production and combustion of coal in thermal plants, production of phosphate mineral fertilizers, production of phosphoric acid, phosphoric plaster, etc

Extended Range Intercept Technology

Science.gov (United States)

1991-09-01

1988). Desert bighorn ewes with lambs show a stronger response than do groups of only rams, only ewes, or mixed groups of adults (Miller and Smith...1985). While all startle events may affect desert bighorns, those occurring during the lambing period (February-April) would represent the highest...35807 U.S. Army Pueblo Depot Activity SDSTE-PU-EE Pueblo, CO 81001-5000 U.S. Army White Sands Missile Range STEWS -EL-N White Sands, NM 88002-5076

An algorithm to improve sampling efficiency for uncertainty propagation using sampling based method

International Nuclear Information System (INIS)

Campolina, Daniel; Lima, Paulo Rubens I.; Pereira, Claubia; Veloso, Maria Auxiliadora F.

2015-01-01

Sample size and computational uncertainty were varied in order to investigate sample efficiency and convergence of the sampling based method for uncertainty propagation. Transport code MCNPX was used to simulate a LWR model and allow the mapping, from uncertain inputs of the benchmark experiment, to uncertain outputs. Random sampling efficiency was improved through the use of an algorithm for selecting distributions. Mean range, standard deviation range and skewness were verified in order to obtain a better representation of uncertainty figures. Standard deviation of 5 pcm in the propagated uncertainties for 10 n-samples replicates was adopted as convergence criterion to the method. Estimation of 75 pcm uncertainty on reactor k eff was accomplished by using sample of size 93 and computational uncertainty of 28 pcm to propagate 1σ uncertainty of burnable poison radius. For a fixed computational time, in order to reduce the variance of the uncertainty propagated, it was found, for the example under investigation, it is preferable double the sample size than double the amount of particles followed by Monte Carlo process in MCNPX code. (author)

How Do Earth-Sized, Short-Period Planets Form?

Science.gov (United States)

Kohler, Susanna

2017-08-01

Matching theory to observation often requires creative detective work. In a new study, scientists have used a clever test to reveal clues about the birth of speedy, Earth-sized planets.Former Hot Jupiters?Artists impression of a hot Jupiter with an evaporating atmosphere. [NASA/Ames/JPL-Caltech]Among the many different types of exoplanets weve observed, one unusual category is that of ultra-short-period planets. These roughly Earth-sized planets speed around their host stars at incredible rates, with periods of less than a day.How do planets in this odd category form? One popular theory is that they were previously hot Jupiters, especially massive gas giants orbiting very close to their host stars. The close orbit caused the planets atmospheres to be stripped away, leaving behind only their dense cores.In a new study, a team of astronomers led by Joshua Winn (Princeton University) has found a clever way to test this theory.Planetary radius vs. orbital period for the authors three statistical samples (colored markers) and the broader sample of stars in the California Kepler Survey. [Winn et al. 2017]Testing MetallicitiesStars hosting hot Jupiters have an interesting quirk: they typically have metallicities that are significantly higher than an average planet-hosting star. It is speculated that this is because planets are born from the same materials as their host stars, and hot Jupiters require the presence of more metals to be able to form.Regardless of the cause of this trend, if ultra-short-period planets are in fact the solid cores of former hot Jupiters, then the two categories of planets should have hosts with the same metallicity distributions. The ultra-short-period-planet hosts should therefore also be weighted to higher metallicities than average planet-hosting stars.To test this, the authors make spectroscopic measurements and gather data for a sample of stellar hosts split into three categories:64 ultra-short-period planets (orbital period shorter than a

Realized range-based estimation of integrated variance

DEFF Research Database (Denmark)

Christensen, Kim; Podolskij, Mark

2007-01-01

We provide a set of probabilistic laws for estimating the quadratic variation of continuous semimartingales with the realized range-based variance-a statistic that replaces every squared return of the realized variance with a normalized squared range. If the entire sample path of the process is a...

The period-luminosity relation for Cepheids

International Nuclear Information System (INIS)

Brodie, J.P.

1980-01-01

Numerical simulations of the empirical determination of the period-luminosity-colour relation for classical Cepheids are presented. In this study the quantitative effects of random errors, reddening, sample size and the presence of both colour and period cut-offs (imposed by the finite extent of the instability strip) on the observational redetermination of the original relation are evaluated. Both random errors in the photometry and correlated errors in the reddening corrections are shown to have systematic effects. Especially sensitive to these errors is the colour coefficient in the period-luminosity-colour relation, where the ratio of the error to the width of the instability strip is the determining factor. With present observations only broad confidence limits can be placed on present knowledge of the intrinsic period-luminosity-colour relation and/or its variations from galaxy to galaxy. (author)

A sensitive LC-MS/MS method for measurement of organophosphorus pesticides and their oxygen analogs in air sampling matrices.

Science.gov (United States)

Armstrong, Jenna L; Dills, Russell L; Yu, Jianbo; Yost, Michael G; Fenske, Richard A

2014-01-01

A rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for determination of levels of the organophosphorus (OP) pesticides chlorpyrifos (CPF), azinphos methyl (AZM), and their oxygen analogs chlorpyrifos-oxon (CPF-O) and azinphos methyl-oxon (AZM-O) on common active air sampling matrices. XAD-2 resin and polyurethane foam (PUF) matrices were extracted with acetonitrile containing stable-isotope labeled internal standards (ISTD). Analysis was accomplished in Multiple Reaction Monitoring (MRM) mode, and analytes in unknown samples were identified by retention time (±0.1 min) and qualifier ratio (±30% absolute) as compared to the mean of calibrants. For all compounds, calibration linearity correlation coefficients were ≥0.996. Limits of detection (LOD) ranged from 0.15-1.1 ng/sample for CPF, CPF-O, AZM, and AZM-O on active sampling matrices. Spiked fortification recoveries were 78-113% from XAD-2 active air sampling tubes and 71-108% from PUF active air sampling tubes. Storage stability tests also yielded recoveries ranging from 74-94% after time periods ranging from 2-10 months. The results demonstrate that LC-MS/MS is a sensitive method for determining these compounds from two different matrices at the low concentrations that can result from spray drift and long range transport in non-target areas following agricultural applications. In an inter-laboratory comparison, the limit of quantification (LOQ) for LC-MS/MS was 100 times lower than a typical gas chromatography-mass spectrometry (GC-MS) method.

Reproducibility of Serum Potassium Values in Serum From Blood Samples Stored for Increasing Times Prior to Centrifugation and Analysis.

Science.gov (United States)

Harper, Aaron; Lu, Chuanyong; Sun, Yi; Garcia, Rafael; Rets, Anton; Alexis, Herol; Saad, Heba; Eid, Ikram; Harris, Loretta; Marshall, Barbara; Tafani, Edlira; Pincus, Matthew R

2016-05-01

The goal of this work was to determine if immediate versus postponed centrifugation of samples affects the levels of serum potassium. Twenty participants donated normal venous blood that was collected in four serum separator tubes per donor, each of which was analyzed at 0, 1, 2, or 4 hr on the Siemens Advia 1800 autoanalyzer. Coefficients of variation (CVs) for potassium levels ranged from 0% to 7.6% with a mean of 3 ± 2%. ANOVA testing of the means for all 20 samples showed a P-value of 0.72 (>0.05) indicating that there was no statistically significant difference between the means of the samples at the four time points. Sixteen samples were found to have CVs that were ≤5%. Two samples showed increases of potassium from the reference range to levels higher than the upper reference limit, one of which had a 4-hr value that was within the reference or normal range (3.5-5 mEq/l). Overall, most samples were found to have reproducible levels of serum potassium. Serum potassium levels from stored whole blood collected in serum separator tubes are, for the most part, stable at room temperature for at least 4 hr prior to analysis. However, some samples can exhibit significant fluctuations of values. © 2015 Wiley Periodicals, Inc.

Three dimensional periodic foundations for base seismic isolation

International Nuclear Information System (INIS)

Yan, Y; Mo, Y L; Cheng, Z; Shi, Z; Menq, F; Tang, Y

2015-01-01

Based on the concept of phononic crystals, periodic foundations made of periodic materials are investigated in this paper. The periodic foundations can provide low frequency band gaps, which cover the main frequency ranges of seismic waves. Therefore, the periodic foundations are able to protect the upper structures during earthquake events. In this paper, the basic theory of three dimensional periodic foundations is studied and the finite element method was used to conduct the sensitivity study. A simplified three-dimensional periodic foundation with a superstructure was tested in the field and the feasibility of three dimensional periodic foundations was proved. The test results showed that the response of the upper structure with the three dimensional periodic foundation was reduced under excitation waves with the main frequency falling in the attenuation zones. The finite element analysis results are consistent with the experimental data, indicating that three dimensional periodic foundations are a feasible way of reducing seismic vibrations. (paper)

Estimation of plant sampling uncertainty: an example based on chemical analysis of moss samples.

Science.gov (United States)

Dołęgowska, Sabina

2016-11-01

In order to estimate the level of uncertainty arising from sampling, 54 samples (primary and duplicate) of the moss species Pleurozium schreberi (Brid.) Mitt. were collected within three forested areas (Wierna Rzeka, Piaski, Posłowice Range) in the Holy Cross Mountains (south-central Poland). During the fieldwork, each primary sample composed of 8 to 10 increments (subsamples) was taken over an area of 10 m 2 whereas duplicate samples were collected in the same way at a distance of 1-2 m. Subsequently, all samples were triple rinsed with deionized water, dried, milled, and digested (8 mL HNO 3 (1:1) + 1 mL 30 % H 2 O 2 ) in a closed microwave system Multiwave 3000. The prepared solutions were analyzed twice for Cu, Fe, Mn, and Zn using FAAS and GFAAS techniques. All datasets were checked for normality and for normally distributed elements (Cu from Piaski, Zn from Posłowice, Fe, Zn from Wierna Rzeka). The sampling uncertainty was computed with (i) classical ANOVA, (ii) classical RANOVA, (iii) modified RANOVA, and (iv) range statistics. For the remaining elements, the sampling uncertainty was calculated with traditional and/or modified RANOVA (if the amount of outliers did not exceed 10 %) or classical ANOVA after Box-Cox transformation (if the amount of outliers exceeded 10 %). The highest concentrations of all elements were found in moss samples from Piaski, whereas the sampling uncertainty calculated with different statistical methods ranged from 4.1 to 22 %.

Application of Back Trajectory Model to Predict Long Range Transport of Pollutant

International Nuclear Information System (INIS)

Shamsiah Abdul Rahman; Mohd Suhaimi Hamzah; Mohd Suhaimi Elias

2011-01-01

Trans-boundary haze pollution in Malaysia has become an issue that created a public attention over the past several years. The presence of haze not only caused by internal and external sources but it sometime coincided with the El Nino phenomenon which prolonged the dry season during the southwest monsoon in May to September. In this study fine particulate data (PM 2.5) of Klang Valley region covering the period from 1997 to 2008 were used to investigate the source location that responsible for the long range transport of pollutant. Back trajectory model the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) was used to calculate the air mass backward trajectories up to 120 hours (5 days) for the days when fine particle were sampled. (author)

Cure of tuberculosis despite serum concentrations of antituberculosis drugs below published reference ranges.

Science.gov (United States)

Meloni, Monica; Corti, Natascia; Müller, Daniel; Henning, Lars; Gutteck, Ursula; von Braun, Amrei; Weber, Rainer; Fehr, Jan

2015-01-01

Therapeutic target serum concentrations of first-line antituberculosis drugs have not been well defined in clinical studies in tuberculosis (TB) patients. We retrospectively investigated the estimated maximum serum concentrations (eC max) of antituberculosis drugs and clinical outcome of TB patients with therapeutic drug monitoring performed between 2010-2012 at our institution, and follow-up until March 2014. The eC max was defined as the highest serum concentration during a sampling period (2, 4 and 6 hours after drug ingestion). We compared the results with published eC max values, and categorised them as either "within reference range", "low eC max", or "very low eC max".Low/very low eC max-levels were defined as follows: isoniazid 2-3/max levels were classified as "low" or "very low". The eC max was below the relevant reference range in 80% of isoniazid, 95% of rifampicin, 30% of pyrazinamide, and 30% of ethambutol measurements. All but one patient were cured of tuberculosis. Although many antituberculosis drug serum concentrations were below the widely used reference ranges, 16 of 17 patients were cured of tuberculosis. These results challenge the use of the published reference ranges for therapeutic drug monitoring.

Fluid sample collection and distribution system. [qualitative analysis of aqueous samples from several points

Science.gov (United States)

Brooks, R. L. (Inventor)

1979-01-01

A multipoint fluid sample collection and distribution system is provided wherein the sample inputs are made through one or more of a number of sampling valves to a progressive cavity pump which is not susceptible to damage by large unfiltered particles. The pump output is through a filter unit that can provide a filtered multipoint sample. An unfiltered multipoint sample is also provided. An effluent sample can be taken and applied to a second progressive cavity pump for pumping to a filter unit that can provide one or more filtered effluent samples. The second pump can also provide an unfiltered effluent sample. Means are provided to periodically back flush each filter unit without shutting off the whole system.

Sampling maternal care behaviour in domestic dogs: What's the best approach?

Science.gov (United States)

Czerwinski, Veronika H; Smith, Bradley P; Hynd, Philip I; Hazel, Susan J

2017-07-01

Our understanding of the frequency and duration of maternal care behaviours in the domestic dog during the first two postnatal weeks is limited, largely due to the inconsistencies in the sampling methodologies that have been employed. In order to develop a more concise picture of maternal care behaviour during this period, and to help establish the sampling method that represents these behaviours best, we compared a variety of time sampling methods Six litters were continuously observed for a total of 96h over postnatal days 3, 6, 9 and 12 (24h per day). Frequent (dam presence, nursing duration, contact duration) and infrequent maternal behaviours (anogenital licking duration and frequency) were coded using five different time sampling methods that included: 12-h night (1800-0600h), 12-h day (0600-1800h), one hour period during the night (1800-0600h), one hour period during the day (0600-1800h) and a one hour period anytime. Each of the one hour time sampling method consisted of four randomly chosen 15-min periods. Two random sets of four 15-min period were also analysed to ensure reliability. We then determined which of the time sampling methods averaged over the three 24-h periods best represented the frequency and duration of behaviours. As might be expected, frequently occurring behaviours were adequately represented by short (oneh) sampling periods, however this was not the case with the infrequent behaviour. Thus, we argue that the time sampling methodology employed must match the behaviour of interest. This caution applies to maternal behaviour in altricial species, such as canids, as well as all systematic behavioural observations utilising time sampling methodology. Copyright © 2017. Published by Elsevier B.V.

Engineering of spatial solitons in two-period QPM structures

DEFF Research Database (Denmark)

Johansen, Steffen Kjær; Carrasco, Silvia; Torner, Lluis

2002-01-01

We report on a scheme which might make it practically possible to engineer the effective competing nonlinearities that on average govern the light propagation in quasi-phase-matching (QPM) gratings. Modulation of the QPM period with a second longer period, introduces an extra degree of freedom...... relative lengths of the two periods and we consider the effect on solitons and the bandwidth for their generation. We derive an expression for the bandwidth of multicolor soliton generation in two-period QPM samples and we predict and confirm numerically that the bandwidth is broader in the two-period QPM...

Evolution of periodicity in periodical cicadas.

Science.gov (United States)

Ito, Hiromu; Kakishima, Satoshi; Uehara, Takashi; Morita, Satoru; Koyama, Takuya; Sota, Teiji; Cooley, John R; Yoshimura, Jin

2015-09-14

Periodical cicadas (Magicicada spp.) in the USA are famous for their unique prime-numbered life cycles of 13 and 17 years and their nearly perfectly synchronized mass emergences. Because almost all known species of cicada are non-periodical, periodicity is assumed to be a derived state. A leading hypothesis for the evolution of periodicity in Magicicada implicates the decline in average temperature during glacial periods. During the evolution of periodicity, the determinant of maturation in ancestral cicadas is hypothesized to have switched from size dependence to time (period) dependence. The selection for the prime-numbered cycles should have taken place only after the fixation of periodicity. Here, we build an individual-based model of cicadas under conditions of climatic cooling to explore the fixation of periodicity. In our model, under cold environments, extremely long juvenile stages lead to extremely low adult densities, limiting mating opportunities and favouring the evolution of synchronized emergence. Our results indicate that these changes, which were triggered by glacial cooling, could have led to the fixation of periodicity in the non-periodical ancestors.

Scattering analysis of periodic structures using finite-difference time-domain

CERN Document Server

ElMahgoub, Khaled; Elsherbeni, Atef Z

2012-01-01

Periodic structures are of great importance in electromagnetics due to their wide range of applications such as frequency selective surfaces (FSS), electromagnetic band gap (EBG) structures, periodic absorbers, meta-materials, and many others. The aim of this book is to develop efficient computational algorithms to analyze the scattering properties of various electromagnetic periodic structures using the finite-difference time-domain periodic boundary condition (FDTD/PBC) method. A new FDTD/PBC-based algorithm is introduced to analyze general skewed grid periodic structures while another algor

Heart rate, multiple body temperature, long-range and long-life telemetry system for free-ranging animals

Science.gov (United States)

Lund, G. F.; Westbrook, R. M.; Fryer, T. B.

1980-01-01

The design details and rationale for a versatile, long-range, long-life telemetry data acquisition system for heart rates and body temperatures at multiple locations from free-ranging animals are presented. The design comprises an implantable transmitter for short to medium range transmission, a receiver retransmitter collar to be worn for long-range transmission, and a signal conditioner interface circuit to assist in signal discrimination and demodulation of receiver or tape-recorded audio outputs. Implanted electrodes are used to obtain an ECG, from which R-wave characteristics are selected to trigger a short RF pulse. Pulses carrying heart rate information are interrupted periodically by a series of pulse interval modulated RF pulses conveying temperature information sensed at desired locations by thermistors. Pulse duration and pulse sequencing are used to discriminate between heart rate and temperature pulses as well as radio frequency interference. The implanted transmitter may be used alone for medium and short-range tracking, or with a receiver-transmitter collar that employs commercial tracking equipment for transmissions of up to 12 km. A system prototype has been tested on a dog.

Seventy years of stream‐fish collections reveal invasions and native range contractions in an Appalachian (USA) watershed

Science.gov (United States)

Buckwalter, Joseph D.; Frimpong, Emmanuel A.; Angermeier, Paul L.; Barney, Jacob N.

2018-01-01

AimKnowledge of expanding and contracting ranges is critical for monitoring invasions and assessing conservation status, yet reliable data on distributional trends are lacking for most freshwater species. We developed a quantitative technique to detect the sign (expansion or contraction) and functional form of range‐size changes for freshwater species based on collections data, while accounting for possible biases due to variable collection effort. We applied this technique to quantify stream‐fish range expansions and contractions in a highly invaded river system.LocationUpper and middle New River (UMNR) basin, Appalachian Mountains, USA.MethodsWe compiled a 77‐year stream‐fish collections dataset partitioned into ten time periods. To account for variable collection effort among time periods, we aggregated the collections into 100 watersheds and expressed a species’ range size as detections per watershed (HUC) sampled (DPHS). We regressed DPHS against time by species and used an information‐theoretic approach to compare linear and nonlinear functional forms fitted to the data points and to classify each species as spreader, stable or decliner.ResultsWe analysed changes in range size for 74 UMNR fishes, including 35 native and 39 established introduced species. We classified the majority (51%) of introduced species as spreaders, compared to 31% of natives. An exponential functional form fits best for 84% of spreaders. Three natives were among the most rapid spreaders. All four decliners were New River natives.Main conclusionsOur DPHS‐based approach facilitated quantitative analyses of distributional trends for stream fishes based on collections data. Partitioning the dataset into multiple time periods allowed us to distinguish long‐term trends from population fluctuations and to examine nonlinear forms of spread. Our framework sets the stage for further study of drivers of stream‐fish invasions and declines in the UMNR and is widely transferable to

Ranging Patterns of Critically Endangered Colobine, Presbytis chrysomelas chrysomelas

Directory of Open Access Journals (Sweden)

Ahmad Ampeng

2012-01-01

Full Text Available Presbytis chrysomelas chrysomelas endemic only in Sarawak and Kalimantan was categorized by IUCN as a critically endangered primate that require special attention from research and conservation perspectives. A qualitative study on ranging patterns of P. c. chrysomelas was conducted in the Samunsam Wildlife Sanctuary, Sarawak. The study was conducted over a period of 13 months from December 2004 to December 2005 with 213 days of observation. Behavioural observation covered 17 groups with special emphasis on two main groups and 1 subadult group. Scanning and focal sampling were employed as the observation methods. Results indicated that P. c. chrysomelas had vertical, straight horizontal, and cross-horizontal types of movement patterns. P. c. chrysomelas was recorded to have a short movement distance (31.8–54.3 m. Distribution, abundance types, and food resources might be the factors that shaped the patterns of movement and distance in P. c. chrysomelas.

Sampling Methodologies for Epidemiologic Surveillance of Men Who Have Sex with Men and Transgender Women in Latin America: An Empiric Comparison of Convenience Sampling, Time Space Sampling, and Respondent Driven Sampling

OpenAIRE

Clark, J. L.; Konda, K. A.; Silva-Santisteban, A.; Peinado, J.; Lama, J. R.; Kusunoki, L.; Perez-Brumer, A.; Pun, M.; Cabello, R.; Sebastian, J. L.; Suarez-Ognio, L.; Sanchez, J.

2014-01-01

Alternatives to convenience sampling (CS) are needed for HIV/STI surveillance of most-at-risk populations in Latin America. We compared CS, time space sampling (TSS), and respondent driven sampling (RDS) for recruitment of men who have sex with men (MSM) and transgender women (TW) in Lima, Peru. During concurrent 60-day periods from June-August, 2011, we recruited MSM/TW for epidemiologic surveillance using CS, TSS, and RDS. A total of 748 participants were recruited through CS, 233 through T...

The effects of model complexity and calibration period on groundwater recharge simulations

Science.gov (United States)

Moeck, Christian; Van Freyberg, Jana; Schirmer, Mario

2017-04-01

A significant number of groundwater recharge models exist that vary in terms of complexity (i.e., structure and parametrization). Typically, model selection and conceptualization is very subjective and can be a key source of uncertainty in the recharge simulations. Another source of uncertainty is the implicit assumption that model parameters, calibrated over historical periods, are also valid for the simulation period. To the best of our knowledge there is no systematic evaluation of the effect of the model complexity and calibration strategy on the performance of recharge models. To address this gap, we utilized a long-term recharge data set (20 years) from a large weighting lysimeter. We performed a differential split sample test with four groundwater recharge models that vary in terms of complexity. They were calibrated using six calibration periods with climatically contrasting conditions in a constrained Monte Carlo approach. Despite the climatically contrasting conditions, all models performed similarly well during the calibration. However, during validation a clear effect of the model structure on model performance was evident. The more complex, physically-based models predicted recharge best, even when calibration and prediction periods had very different climatic conditions. In contrast, more simplistic soil-water balance and lumped model performed poorly under such conditions. For these models we found a strong dependency on the chosen calibration period. In particular, our analysis showed that this can have relevant implications when using recharge models as decision-making tools in a broad range of applications (e.g. water availability, climate change impact studies, water resource management, etc.).

Comparative study of optical properties of the one-dimensional multilayer Period-Doubling and Thue-Morse quasi-periodic photonic crystals

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Y. Bouazzi

2012-10-01

Full Text Available The last decades have witnessed the growing interest in the use of photonic crystal as a new material that can be used to control electromagnetic wave. Actually, not only the periodic structures but also the quasi-periodic systems have become significant structures of photonic crystals. This work deals with optical properties of dielectric Thue-Morse multilayer and Period-Doubling multilayer. We use the so-called Transfer Matrix Method (TMM to determine the transmission spectra of the structures. Based on the representation of the transmittance spectra in the visible range a comparative analysis depending on the iteration number, number of layers and incidence angle is presented.

Image Sampling with Quasicrystals

Directory of Open Access Journals (Sweden)

Mark Grundland

2009-07-01

Full Text Available We investigate the use of quasicrystals in image sampling. Quasicrystals produce space-filling, non-periodic point sets that are uniformly discrete and relatively dense, thereby ensuring the sample sites are evenly spread out throughout the sampled image. Their self-similar structure can be attractive for creating sampling patterns endowed with a decorative symmetry. We present a brief general overview of the algebraic theory of cut-and-project quasicrystals based on the geometry of the golden ratio. To assess the practical utility of quasicrystal sampling, we evaluate the visual effects of a variety of non-adaptive image sampling strategies on photorealistic image reconstruction and non-photorealistic image rendering used in multiresolution image representations. For computer visualization of point sets used in image sampling, we introduce a mosaic rendering technique.

Eggshell apex abnormalities in a free-range hen farm with mycoplasma synoviae and infectious bronchitis virus in Rio de Janeiro state, Brazil

Directory of Open Access Journals (Sweden)

FC dos Santos

2014-06-01

Full Text Available A farm with 3,000 free-range hens between 24 and 65 weeks of age was investigated. These hens were separated in small flocks of 400 to 700 birds, presenting 10 to 23% egg production reduction. Twenty serum samples were collected during the period of drop in egg production and three weeks later for the investigation of Mycoplasma synoviae (MS, M. gallisepticum (MG and Infectious Bronchitis Virus (IBV antibodies using ELISA. At the time of the second collection, egg production had resumed to normal levels; however, with 10.23% of the eggs showed eggshell abnormalities limited to the apex. Eggshell strength was significantly different between normal and those with eggshell apex abnormalities, but not other egg-quality parameters. ELISA tests showed that MS and IBV titers increased during the evaluated period. MS infection was confirmed by culture and by PCR of tracheal swabs. All samples were negative for MG by ELISA and PCR. Further studies with larger samples to ensure the occurrence of this disease in industrial layer flocks in Brazil are under way.

Isolation of Uncultured Bacteria from Antarctica Using Long Incubation Periods and Low Nutritional Media

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Andre A. Pulschen

2017-07-01

Full Text Available Uncultured microorganisms comprise most of the microbial diversity existing on our planet. Despite advances in environmental sequencing and single-cell genomics, in-depth studies about bacterial metabolism and screening of novel bioproducts can only be assessed by culturing microbes in the laboratory. Here we report uncultured, or recalcitrant, microorganisms from an Antarctic soil sample, using relatively simple methods: oligotrophic media, extended incubation periods, observation under stereo microscopy, and selection of slow-growing bacteria. We managed to isolate several rare microorganisms belonging to infrequently isolated or recently described genera, for example Lapillicoccus, Flavitalea, Quadrisphaera, Motilibacter, and Polymorphobacter. Additionally, we obtained isolates presenting 16S rRNA sequence similarity ranging from 92.08 to 94.46% with any other known cultured species, including two distinct isolates from the class Thermoleophilia, that although common in Antarctic soils (as identified by metagenomics, was never reported to be isolated from such samples. Our data indicates that simple methods are still useful for cultivating recalcitrant microorganisms, even when dealing with samples from extreme environments.

Elevated PCDD/F levels and distinctive PCDD/F congener profiles in free range eggs.

Science.gov (United States)

Hsu, Jing-Fang; Chen, Chun; Liao, Pao-Chi

2010-07-14

Chicken eggs are one of the most important foods in the human diet all over the world, and the demand for eggs from free range hens has steadily increased. Congener-specific analyses of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were performed on 6 free range and 12 caged chicken egg samples collected in Taiwan. The mean level of PCDD/Fs in the free range egg samples was 5.7 (1.79/0.314) times higher than those in the caged egg samples. Principle component analysis revealed that at least three characteristic patterns of PCDD/F congener were observed among the 18 egg samples. The different PCDD/F congener patterns between free range and caged egg samples may reflect distinctive exposure scenarios among the free range and caged hens. We suggest that the differences of PCDD/F levels and congener patterns between free range and caged egg samples give rise to the issues related to the safety of eating free range chicken eggs. The present data may provide useful information for further investigation of the possible PCDD/F sources in the contaminated free range eggs.

Periodic variations of cosmic ray intensity with period of -37 minute observed on April 25th, 1984

International Nuclear Information System (INIS)

Sakai, Takasuke; Kato, Masahito; Takei, Ryoji; Tamai, Eiji

1985-01-01

Existence of cosmic ray variation with period ranging from a few hours to seconds during geomagnetically quiet and perturb period at different altitude with different detector, was reported previously. As short period variation is thought to be transient with small amplitude fluctuation, consequently high counting rate of cosmic ray and appropriate method for finding short periodicity, is required. Further, there is similar phenomenon in which short variation, followed by storm sudden commencement (SSC) and/or Forbush decrease (FD) occurs. In 1979, Kato et al. used 3 minutes data at Mt. Norikura and obtained -6 x 10 5 count/min, and tried to find out short periodicity of cosmic ray around SSC, but no clear conclusion was obtained. T. Sakai, et al., used plastic scintillation counter of Akeno observatory, following their preceding work. The counter has an area about 154 m 2 . High counting rate of -2 x 10 6 counts/min. was observed at Akeno which revealed the existence of -37 minute periodical oscillation with an amplitude of 0.1 % in p-p during the time period of 1300 - 1900 UT on April 25th 1984, one day before FD. Observed periodical oscillation of cosmic ray counting rate may be the result of the changes in magnetic field. But, it must be noted that there remains possibility of oscillation of cosmic ray intensity in the interplanetary space during the period, independent of geomagnetic field. (author)

Elegant grapheme-phoneme correspondence: a periodic chart and singularity generalization unify decoding.

Science.gov (United States)

Gates, Louis

2017-12-11

The accompanying article introduces highly transparent grapheme-phoneme relationships embodied within a Periodic table of decoding cells, which arguably presents the quintessential transparent decoding elements. The study then folds these cells into one highly transparent but simply stated singularity generalization-this generalization unifies the decoding cells (97% transparency). Deeper, the periodic table and singularity generalization together highlight the connectivity of the periodic cells. Moreover, these interrelated cells, coupled with the singularity generalization, clarify teaching targets and enable efficient learning of the letter-sound code. This singularity generalization, in turn, serves as a model for creating unified but easily stated subordinate generalizations for any one of the transparent cells or groups of cells shown within the tables. The article then expands the periodic cells into two tables of teacher-ready sample word lists-one table includes sample words for the basic and phonogram vowel cells, and the other table embraces word samples for the transparent consonant cells. The paper concludes with suggestions for teaching the cellular transparency embedded within reoccurring isolated words and running text to promote decoding automaticity of the periodic cells.

Actinide concentrations in tissues from cattle grazing a contaminated range

International Nuclear Information System (INIS)

Smith, D.D.; Bernhardt, D.E.

1977-01-01

Actinide concentrations in the tissues of beef animals periodically sacrificed and sampled during a 3-year grazing study on a plutonium-contaminated range of the Nevada Test Site are discussed. Actinide concentrations in the skeletons of the cows originally introduced into the study areas showed little increase with increased time of exposure, while those of animals born in the study areas showed a continued upward trend with time. Plutonium-239/americium-241 ratios in tissues and ingesta suggest little differentiation in the uptake of these radionuclides. However, the plutonium-239/plutonium-238 ratios indicate that plutonium-238 is more readily absorbed. The gonadal concentrations of the actinides were significantly higher than those of blood and muscle and approached those of bone. These data indicate that consideration should be given to the plutonium-239 dose to gonads as well as that to bone, liver, and lungs of man

Bioaccessibility of selected trace metals in urban PM{sub 2.5} and PM{sub 10} samples: a model study

Energy Technology Data Exchange (ETDEWEB)

Falta, Thomas; Koellensperger, Gunda; Hann, Stephan [University of Natural Resources and Applied Life Sciences, Division of Analytical Chemistry, Vienna (Austria); Limbeck, Andreas [Vienna University of Technology, Institute of Chemical Technologies and Analytics, Vienna (Austria)

2008-02-15

Bioaccessibility of trace metals originating from urban particulate matter was assessed in a worst case scenario to evaluate the uptake and thus the hazardous potential of these metals via gastric juice. Sampling was performed over a period of about two months at the Getreidemarkt in downtown Vienna. Concentrations of the assayed trace metals (Ti, Cr, Mn, Co, Ni, Cu, Zn, Mo, Ag, Cd, Sn, Sb, Tl and Pb) were determined in PM{sub 2.5} and PM{sub 10} samples by ICP-MS. The metal concentrations in sampled air were in the low picogram to high nanogram per cubic metre range. The concentrations in PM{sub 2.5} samples were generally lower than those in PM{sub 10} samples. The average daily intake of these metals by inhalation for a healthy adult was estimated to be in the range of <1 ng (Tl) to >1,000 ng (Zn). To estimate the accessibility of the inhaled and subsequently ingested metals (i.e. after lung clearance had taken place) in the size range from 2.5- to 10-{mu}m aerodynamic equivalent diameter, a batch-extraction with synthetic gastric juice was performed. The data were used to calculate the bioaccessibility of the investigated trace metals. Extractable fractions ranged from 2.10% (Ti in PM{sub 2.5}) to 91.0% (Cd in PM{sub 2.5}), thus yielding bioaccessible fractions (PM{sub 2.5-10}) from 0.16 ng (Ag) to 178 ng (Cu). (orig.)

Total and non-seasalt sulfate and chloride measured in bulk precipitation samples from the Kilauea Volcano area, Hawaii

Science.gov (United States)

Scholl, M.A.; Ingebritsen, S.E.

1995-01-01

Six-month cumulative precipitation samples provide estimates of bulk deposition of sulfate and chloride for the southeast part of the Island of Hawaii during four time periods: August 1991 to February 1992, February 1992 to September 1992, March 1993 to September 1993, and September 1993 to February 1994. Total estimated bulk deposition rates for sulfate ranged from 0.12 to 24 grams per square meter per 180 days, and non-seasalt sulfate deposition ranged from 0.06 to 24 grams per square meter per 180 days. Patterns of non-seasalt sulfate deposition were generally related to prevailing wind directions and the proximity of the collection site to large sources of sulfur gases, namely Kilauea Volcano's summit and East Rift Zone eruption. Total chloride deposition from bulk precipitation samples ranged from 0.01 to 17 grams per square meter per 180 days. Chloride appeared to be predominantly from oceanic sources, as non- seasalt chloride deposition was near zero for most sites.

Prevalence of pathogens in milk samples of dairy cows with clinical mastitis and in heifers at first parturition.

Science.gov (United States)

Tenhagen, Bernd-Alois; Hansen, Inken; Reinecke, Annette; Heuwieser, Wolfgang

2009-05-01

Prevalence of mastitis pathogens in milk samples from dairy cows and heifers was studied over a period of 1 year (Aug 2005-Aug 2006) in ten dairy herds in Germany. Milk samples (n=8240) were collected from heifers without clinical mastitis at parturition (n=6915), from primiparous cows with clinical mastitis (n=751) and from older cows with clinical mastitis (n=574). Coagulase negative staphylococci (CNS) were the predominant group of bacteria isolated (46.8% of samples) from clinically healthy quarters of primiparous cows around parturition, followed by streptococci (12.6%), coliforms (4.7%) and Staphylococcus aureus (4.0%). Thirty-three percent of samples were negative on culture (range on farm level, 12.0-46.4%). In cases of clinical mastitis in primiparous and older cows, streptococci were the predominant finding (32.1 and 39.2%) followed by CNS (27.4 and 16.4%), coliforms (10.3 and 13.1%) and Staph. aureus (10.0 and 11.7%). Negative results were obtained from 21.3% (range, 0.0-30.6%) and 19.5% (range, 0.0-32.6%) of these samples. Results indicated substantial differences in the prevalence of pathogens among herds. There was a positive within-herd correlation between the monthly prevalences for Streptococcus dysgalactiae between the three groups of samples. This correlation was also found between clinical samples of primiparous and older cows for Staph. aureus. These correlations were not found for the other pathogens. Besides herd, prevalence of pathogens was influenced by parity, type of sample and season.

Fiber optics frequency comb enabled linear optical sampling with operation wavelength range extension.

Science.gov (United States)

Liao, Ruolin; Wu, Zhichao; Fu, Songnian; Zhu, Shengnan; Yu, Zhe; Tang, Ming; Liu, Deming

2018-02-01

Although the linear optical sampling (LOS) technique is powerful enough to characterize various advanced modulation formats with high symbol rates, the central wavelength of a pulsed local oscillator (LO) needs to be carefully set according to that of the signal under test, due to the coherent mixing operation. Here, we experimentally demonstrate wideband LOS enabled by a fiber optics frequency comb (FOFC). Meanwhile, when the broadband FOFC acts as the pulsed LO, we propose a scheme to mitigate the enhanced sampling error arising in the non-ideal response of a balanced photodetector. Finally, precise characterizations of arbitrary 128 Gbps PDM-QPSK wavelength channels from 1550 to 1570 nm are successfully achieved, when a 101.3 MHz frequency spaced comb with a 3 dB spectral power ripple of 20 nm is used.

1-Hydroxypyrene Levels in Blood Samples of Rats After Exposure to Generator Fumes

Science.gov (United States)

Ifegwu, Clinton; Igwo-Ezikpe, Miriam N.; Anyakora, Chimezie; Osuntoki, Akinniyi; Oseni, Kafayat A.; Alao, Eragbae O.

2013-01-01

Polynuclear Aromatic Hydrocarbons (PAHs) are a major component of fuel generator fumes. Carcinogenicity of these compounds has long been established. In this study, 37 Swiss albino rats were exposed to generator fumes at varied distances for 8 hours per day for a period of 42 days and the level of 1-hydroxypyrene in their blood was evaluated. This study also tried to correlate the level of blood 1-hyroxypyrene with the distance from the source of pollution. Plasma was collected by centrifuging the whole blood sample followed by complete hydrolysis of the conjugated 1-hydroxypyrene glucuronide to yield the analyte of interest, 1-hydroxypyrene, which was achieved using beta glucuronidase. High performance liquid chromatography (HPLC) with UV detector was used to determine the 1-hydroxypyrene concentrations in the blood samples. The mobile phase was water:methanol (12:88 v/v) isocratic run at the flow rate of 1.2 mL/min with CI8 stationary phase at 250 nm. After 42 days of exposure, blood concentration level of 1-hydroxypyrene ranged from 34 μg/mL to 26.29 μg/mL depending on the distance from source of exposure. The control group had no 1-hydroxypyrene in their blood. After the period of exposure, percentage of death correlated with the distance from the source of exposure. Percentage of death ranged from 56% to zero depending on the proximity to source of pollution. PMID:24179393

A persisting secondhand smoke hazard in urban public places: results from fine particulate (PM2.5) air sampling.

Science.gov (United States)

Wilson, Nick; Edwards, Richard; Parry, Rhys

2011-03-04

To assess the need for additional smokefree settings, by measuring secondhand smoke (SHS) in a range of public places in an urban setting. Measurements were made in Wellington City during the 6-year period after the implementation of legislation that made indoor areas of restaurants and bars/pubs smokefree in December 2004, and up to 20 years after the 1990 legislation making most indoor workplaces smokefree. Fine particulate levels (PM2.5) were measured with a portable real-time airborne particle monitor. We collated data from our previously published work involving random sampling, purposeful sampling and convenience sampling of a wide range of settings (in 2006) and from additional sampling of selected indoor and outdoor areas (in 2007-2008 and 2010). The "outdoor" smoking areas of hospitality venues had the highest particulate levels, with a mean value of 72 mcg/m3 (range of maximum values 51-284 mcg/m3) (n=20 sampling periods). These levels are likely to create health hazards for some workers and patrons (i.e., when considered in relation to the WHO air quality guidelines). National survey data also indicate that these venues are the ones where SHS exposure is most frequently reported by non-smokers. Areas inside bars that were adjacent to "outdoor" smoking areas also had high levels, with a mean of 54 mcg/m3 (range of maximum values: 18-239 mcg/m3, for n=13 measurements). In all other settings mean levels were lower (means: 2-22 mcg/m3). These other settings included inside traditional style pubs/sports bars (n=10), bars (n=18), restaurants (n=9), cafes (n=5), inside public buildings (n=15), inside transportation settings (n=15), and various outdoor street/park settings (n=22). During the data collection in all settings made smokefree by law, there was only one occasion of a person observed smoking. The results suggest that compliance in pubs/bars and restaurants has remained extremely high in this city in the nearly six years since implementation of the

A Microfluidic Long-Period Fiber Grating Sensor Platform for Chloride Ion Concentration Measurement

Directory of Open Access Journals (Sweden)

Jian-Neng Wang

2011-09-01

Full Text Available Optical fiber sensors based on waveguide technology are promising and attractive in chemical, biotechnological, agronomy, and civil engineering applications. A microfluidic system equipped with a long-period fiber grating (LPFG capable of measuring chloride ion concentrations of several sample materials is presented. The LPFG-based microfluidic platform was shown to be effective in sensing very small quantities of samples and its transmitted light signal could easily be used as a measurand. The investigated sample materials included reverse osmosis (RO water, tap water, dilute aqueous sample of sea sand soaked in RO water, aqueous sample of sea sand soaked in RO water, dilute seawater, and seawater. By employing additionally a chloride ion-selective electrode sensor for the calibration of chloride-ion concentration, a useful correlation (R2 = 0.975 was found between the separately-measured chloride concentration and the light intensity transmitted through the LPFG at a wavelength of 1,550 nm. Experimental results show that the sensitivity of the LPFG sensor by light intensity interrogation was determined to be 5.0 × 10−6 mW/mg/L for chloride ion concentrations below 2,400 mg/L. The results obtained from the analysis of data variations in time-series measurements for all sample materials show that standard deviations of output power were relatively small and found in the range of 7.413 × 10−5–2.769 × 10−3 mW. In addition, a fairly small coefficients of variations were also obtained, which were in the range of 0.03%–1.29% and decreased with the decrease of chloride ion concentrations of sample materials. Moreover, the analysis of stability performance of the LPFG sensor indicated that the random walk coefficient decreased with the increase of the chloride ion concentration, illustrating that measurement stability using the microfluidic platform was capable of measuring transmitted optical power with accuracy in the range of −0

Proteomic Challenges: Sample Preparation Techniques for Microgram-Quantity Protein Analysis from Biological Samples

Directory of Open Access Journals (Sweden)

Peter Feist

2015-02-01

Full Text Available Proteins regulate many cellular functions and analyzing the presence and abundance of proteins in biological samples are central focuses in proteomics. The discovery and validation of biomarkers, pathways, and drug targets for various diseases can be accomplished using mass spectrometry-based proteomics. However, with mass-limited samples like tumor biopsies, it can be challenging to obtain sufficient amounts of proteins to generate high-quality mass spectrometric data. Techniques developed for macroscale quantities recover sufficient amounts of protein from milligram quantities of starting material, but sample losses become crippling with these techniques when only microgram amounts of material are available. To combat this challenge, proteomicists have developed micro-scale techniques that are compatible with decreased sample size (100 μg or lower and still enable excellent proteome coverage. Extraction, contaminant removal, protein quantitation, and sample handling techniques for the microgram protein range are reviewed here, with an emphasis on liquid chromatography and bottom-up mass spectrometry-compatible techniques. Also, a range of biological specimens, including mammalian tissues and model cell culture systems, are discussed.

Proteomic Challenges: Sample Preparation Techniques for Microgram-Quantity Protein Analysis from Biological Samples

Science.gov (United States)

Feist, Peter; Hummon, Amanda B.

2015-01-01

Proteins regulate many cellular functions and analyzing the presence and abundance of proteins in biological samples are central focuses in proteomics. The discovery and validation of biomarkers, pathways, and drug targets for various diseases can be accomplished using mass spectrometry-based proteomics. However, with mass-limited samples like tumor biopsies, it can be challenging to obtain sufficient amounts of proteins to generate high-quality mass spectrometric data. Techniques developed for macroscale quantities recover sufficient amounts of protein from milligram quantities of starting material, but sample losses become crippling with these techniques when only microgram amounts of material are available. To combat this challenge, proteomicists have developed micro-scale techniques that are compatible with decreased sample size (100 μg or lower) and still enable excellent proteome coverage. Extraction, contaminant removal, protein quantitation, and sample handling techniques for the microgram protein range are reviewed here, with an emphasis on liquid chromatography and bottom-up mass spectrometry-compatible techniques. Also, a range of biological specimens, including mammalian tissues and model cell culture systems, are discussed. PMID:25664860

Proteomic challenges: sample preparation techniques for microgram-quantity protein analysis from biological samples.

Science.gov (United States)

Feist, Peter; Hummon, Amanda B

2015-02-05

Proteins regulate many cellular functions and analyzing the presence and abundance of proteins in biological samples are central focuses in proteomics. The discovery and validation of biomarkers, pathways, and drug targets for various diseases can be accomplished using mass spectrometry-based proteomics. However, with mass-limited samples like tumor biopsies, it can be challenging to obtain sufficient amounts of proteins to generate high-quality mass spectrometric data. Techniques developed for macroscale quantities recover sufficient amounts of protein from milligram quantities of starting material, but sample losses become crippling with these techniques when only microgram amounts of material are available. To combat this challenge, proteomicists have developed micro-scale techniques that are compatible with decreased sample size (100 μg or lower) and still enable excellent proteome coverage. Extraction, contaminant removal, protein quantitation, and sample handling techniques for the microgram protein range are reviewed here, with an emphasis on liquid chromatography and bottom-up mass spectrometry-compatible techniques. Also, a range of biological specimens, including mammalian tissues and model cell culture systems, are discussed.

Discovery of a 115 Day Orbital Period in the Ultraluminous X-ray Source NGC 5408 X-1

Science.gov (United States)

Strohmayer, Tod E.

2009-01-01

We report the detection of a 115 day periodicity in SWIFT/XRT monitoring data from the ultraluminous X-ray source (ULX) NGC 5408 X-1. Our o ngoing campaign samples its X-ray flux approximately twice weekly and has now achieved a temporal baseline of ti 485 days. Periodogram ana lysis reveals a significant periodicity with a period of 115.5 +/- 4 days. The modulation is detected with a significance of 3.2 x 10(exp -4) . The fractional modulation amplitude decreases with increasing e nergy, ranging from 0.13 +/- 0.02 above 1 keV to 0.24 +/- 0.02 below 1 keV. The shape of the profile evolves as well, becoming less sharply peaked at higher energies. The periodogram analysis is consistent wi th a periodic process, however, continued monitoring is required to c onfirm the coherent nature of the modulation. Spectral analysis indic ates that NGC 5408 X-1 can reach 0.3 - 10 keV luminosities of approxi mately 2 x 10 40 ergs/s . We suggest that, like the 62 day period of the ULX in M82 (X41.4-1-60), the periodicity detected in NGC 5408 X-1 represents the orbital period of the black hole binary containing the ULX. If this is true then the secondary can only be a giant or super giant star.

Modelling Quasi-Periodic Pulsations in Solar and Stellar Flares

Science.gov (United States)

McLaughlin, J. A.; Nakariakov, V. M.; Dominique, M.; Jelínek, P.; Takasao, S.

2018-02-01

Solar flare emission is detected in all EM bands and variations in flux density of solar energetic particles. Often the EM radiation generated in solar and stellar flares shows a pronounced oscillatory pattern, with characteristic periods ranging from a fraction of a second to several minutes. These oscillations are referred to as quasi-periodic pulsations (QPPs), to emphasise that they often contain apparent amplitude and period modulation. We review the current understanding of quasi-periodic pulsations in solar and stellar flares. In particular, we focus on the possible physical mechanisms, with an emphasis on the underlying physics that generates the resultant range of periodicities. These physical mechanisms include MHD oscillations, self-oscillatory mechanisms, oscillatory reconnection/reconnection reversal, wave-driven reconnection, two loop coalescence, MHD flow over-stability, the equivalent LCR-contour mechanism, and thermal-dynamical cycles. We also provide a histogram of all QPP events published in the literature at this time. The occurrence of QPPs puts additional constraints on the interpretation and understanding of the fundamental processes operating in flares, e.g. magnetic energy liberation and particle acceleration. Therefore, a full understanding of QPPs is essential in order to work towards an integrated model of solar and stellar flares.

Wide range noble gas radiation monitor

International Nuclear Information System (INIS)

Kuhlman, H.S. III; Wyvill, J.R.

1984-01-01

The present invention contemplates providing a sample system for effluent from a nuclear process wherein the effluent in a first mode passes through a sample chamber whose noble gases are quantitatively detected. The sample of the first mode is continued until the detector count rate reaches a predetermined maximum. The detector establishes a control signal which is applied to terminate the first mode effluent flow to the chamber, evacuate the chamber to a predetermined value of vacuum and connect the effluent into the sample chamber with a predetermined mode of flow rate different from the rate of the first mode to establish a sample concentration in the chamber within the range of the detector. A subsequent predetermined minimum rate will generate a signal to reconnect the sample chamber to the first mode connection and thereby cycle the system back to its first mode of operation

Fission products in National Atmospheric Deposition Program—Wet deposition samples prior to and following the Fukushima Dai-Ichi Nuclear Power Plant incident, March 8?April 5, 2011

Science.gov (United States)

Wetherbee, Gregory A.; Debey, Timothy M.; Nilles, Mark A.; Lehmann, Christopher M.B.; Gay, David A.

2012-01-01

Radioactive isotopes I-131, Cs-134, or Cs-137, products of uranium fission, were measured at approximately 20 percent of 167 sampled National Atmospheric Deposition Program monitoring sites in North America (primarily in the contiguous United States and Alaska) after the Fukushima Dai-Ichi Nuclear Power Plant incident on March 12, 2011. Samples from the National Atmospheric Deposition Program were analyzed for the period of March 8-April 5, 2011. Calculated 1- or 2-week radionuclide deposition fluxes at 35 sites from Alaska to Vermont ranged from 0.47 to 5,100 Becquerels per square meter during the sampling period of March 15-April 5, 2011. No fission-product isotopes were measured in National Atmospheric Deposition Program samples obtained during March 8-15, 2011, prior to the arrival of contaminated air in North America.

Metrological large range scanning probe microscope

International Nuclear Information System (INIS)

Dai Gaoliang; Pohlenz, Frank; Danzebrink, Hans-Ulrich; Xu Min; Hasche, Klaus; Wilkening, Guenter

2004-01-01

We describe a metrological large range scanning probe microscope (LR-SPM) with an Abbe error free design and direct interferometric position measurement capability, aimed at versatile traceable topographic measurements that require nanometer accuracy. A dual-stage positioning system was designed to achieve both a large measurement range and a high measurement speed. This dual-stage system consists of a commercially available stage, referred to as nanomeasuring machine (NMM), with a motion range of 25 mmx25 mmx5 mm along x, y, and z axes, and a compact z-axis piezoelectric positioning stage (compact z stage) with an extension range of 2 μm. The metrological LR-SPM described here senses the surface using a stationary fixed scanning force microscope (SFM) head working in contact mode. During operation, lateral scanning of the sample is performed solely by the NMM. Whereas the z motion, controlled by the SFM signal, is carried out by a combination of the NMM and the compact z stage. In this case the compact z stage, with its high mechanical resonance frequency (greater than 20 kHz), is responsible for the rapid motion while the NMM simultaneously makes slower movements over a larger motion range. To reduce the Abbe offset to a minimum the SFM tip is located at the intersection of three interferometer measurement beams orientated in x, y, and z directions. To improve real time performance two high-end digital signal processing (DSP) systems are used for NMM positioning and SFM servocontrol. Comprehensive DSP firmware and Windows XP-based software are implemented, providing a flexible and user-friendly interface. The instrument is able to perform large area imaging or profile scanning directly without stitching small scanned images. Several measurements on different samples such as flatness standards, nanostep height standards, roughness standards as well as sharp nanoedge samples and 1D gratings demonstrate the outstanding metrological capabilities of the instrument

The new Chalk River AMS ion source, sample changer and external sample magazine

International Nuclear Information System (INIS)

Koslowsky, V.T.; Bray, N.; Imahori, Y.; Andrews, H.R.; Davies, W.G.

1997-01-01

A new sample magazine, sample changer and ion source have been developed and are in routine use at Chalk River. The system features a readily accessible 40-sample magazine at ground potential that is external to the ion source and high-voltage cage. The samples are held in an inert atmosphere and can be individually examined or removed; they can be exchanged en masse as a complete magazine concurrent with an AMS measurement. On-line sample changing is done with a pneumatic rabbit transfer system employing two stages of differential pumping. At Chalk River this is routinely performed across a 200 kV potential. Sample positioning is precise, and hundreds of 36 Cl and 129 I samples have been measured over a period of several days without interruption or alteration of ion source operating conditions. (author)

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the northeastern Alaska Range, Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska

Science.gov (United States)

Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

2015-01-01

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 670 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the northeastern Alaska Range, in the Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical

Variability and reliability of POP concentrations in multiple breast milk samples collected from the same mothers.

Science.gov (United States)

Kakimoto, Risa; Ichiba, Masayoshi; Matsumoto, Akiko; Nakai, Kunihiko; Tatsuta, Nozomi; Iwai-Shimada, Miyuki; Ishiyama, Momoko; Ryuda, Noriko; Someya, Takashi; Tokumoto, Ieyasu; Ueno, Daisuke

2018-01-13

Risk assessment of infant using a realistic persistent organic pollutant (POP) exposure through breast milk is essential to devise future regulation of POPs. However, recent investigations have demonstrated that POP levels in breast milk collected from the same mother showed a wide range of variation daily and monthly. To estimate the appropriate sample size of breast milk from the same mother to obtain reliable POP concentrations, breast milk samples were collected from five mothers living in Japan from 2006 to 2012. Milk samples from each mother were collected 3 to 6 times a day through 3 to 7 days consecutively. Food samples as the duplicated method were collected from two mothers during the period of breast milk sample collection. Those were employed for POP (PCBs, DDTs, chlordanes, and HCB) analysis. PCB concentrations detected in breast milk samples showed a wide range of variation which was maximum 63 and 60% of relative standard deviation (RSD) in lipid and wet weight basis, respectively. The time course trend of those variations among the mothers did not show any typical pattern. A larger amount of PCB intake through food seemed to affect 10 h after those concentrations in breast milk in lipid weight basis. Intraclass correlation coefficient (ICC) analyses indicated that the appropriate sample size for good reproducibility of POP concentrations in breast milk required at least two samples for lipid and wet weight basis.

The Gogebic Iron Range - A Sample of the Northern Margin of the Penokean Fold and Thrust Belt

Science.gov (United States)

Cannon, William F.; LaBerge, Gene L.; Klasner, John S.; Schulz, Klaus J.

2008-01-01

The Gogebic iron range is an elongate belt of Paleoproterozoic strata extending from the west shore of Lake Gogebic in the upper peninsula of Michigan for about 125 km westward into northern Wisconsin. It is one of six major informally named iron ranges in the Lake Superior region and produced about 325 million tons of direct-shipping ore between 1887 and 1967. A significant resource of concentrating-grade ore remains in the western and eastern parts of the range. The iron range forms a broad, gently southward-opening arc where the central part of the range exposes rocks that were deposited somewhat north of the eastern and western parts. A fundamental boundary marking both the tectonic setting of deposition and the later deformation within the Penokean orogen lies fortuitously in an east-west direction along the range so that the central part of the range preserves sediments deposited north of that boundary, whereas the eastern and western parts of the range were deposited south of the boundary. Thus, the central part of the range provides a record of sedimentation and very mild deformation in a part of the Penokean orogen farthest from the interior of the orogen to the south. The eastern and western parts of the range, in contrast, exhibit a depositional and deformational style typical of parts closer to the interior of the orogen. A second fortuitous feature of the iron range is that the entire area was tilted from 40° to 90° northward by Mesoproterozoic deformation so that the map view offers an oblique cross section of the Paleoproterozoic sedimentary sequence and structures. Together, these features make the Gogebic iron range a unique area in which to observe (1) the lateral transition from deposition on a stable platform to deposition in a tectonically and volcanically active region, and (2) the transition from essentially undeformed Paleoproterozoic strata to their folded and faulted equivalents.Paleoproterozoic strata in the Gogebic iron range are part

Pesticide Residues, Results from the period 2004-2011

DEFF Research Database (Denmark)

Petersen, Annette; Jensen, Bodil Hamborg; Andersen, Jens Hinge

The present report presents the results from the 2004-2011 period of the monitoring programmes conducted by The Danish Veterinary and Food Administration. The programmes included commodities of fruit, vegetable, cereals and animal origin using random sampling from food on the Danish market. Since...... the beginning of the 1960, Denmark has monitored fruit and vegetables for pesticides residues. For the periods 1993-1997 and 1998-2003, results were collated and the dietary exposure was calculated. In this report data for the analyses carried out in the period 2004-2011 are reported as well as the exposure...

Resonant Quasi-Optical Systems with Multi-Row Periodic Structures

DEFF Research Database (Denmark)

Oleksandr, Rybalko; Rybalko, Yu A.; Buriak, I. A.

2017-01-01

Selective properties of resonant quasi-optical systems with periodical multi-row structures in millimeter wavelength range are described. The possibility of selection fluctuations in the volume of open resonator using double-row periodic elements was shown in the experiment at 70-80 GHz. Advantages...... and possibility of control the energy characteristics of such structures are also described. The obtained experimental data is used to confirm the results of computational analysis previously described in the literature. Implementation of resonant quasi-optical systems with multi-row periodic structures...

Reduction of Friction of Metals Using Laser-Induced Periodic Surface Nanostructures

OpenAIRE

Zhuo Wang; Quanzhong Zhao; Chengwei Wang

2015-01-01

We report on the effect of femtosecond-laser-induced periodic surface structures (LIPSS) on the tribological properties of stainless steel. Uniform periodic nanostructures were produced on AISI 304L (American Iron and Steel Institute steel grade) steel surfaces using an 800-nm femtosecond laser. The spatial periods of LIPSS measured by field emission scanning electron microscopy ranged from 530 to 570 nm. The tribological properties of smooth and textured surfaces with periodic nanostructures...

Gestation period and twinning in chimpanzees.

Science.gov (United States)

PEACOCK, L J; ROGERS, C M

1959-04-10

The length of the gestation period in 118 births in a colony of chimpanzees was found to be 226.8 days, with a standard deviation of 13.3 and a range of 196 to 260 days. Six pairs of twins were born in 120 parturitions; thus the apparent twinning rate is higher than that in man.

Forecasting with periodic autoregressive time series models

NARCIS (Netherlands)

Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)

1999-01-01

textabstractThis paper is concerned with forecasting univariate seasonal time series data using periodic autoregressive models. We show how one should account for unit roots and deterministic terms when generating out-of-sample forecasts. We illustrate the models for various quarterly UK consumption

Short period tidal variations of earth rotation

Science.gov (United States)

Yoder, C. F.; Williams, J. G.; Parke, M. E.; Dickey, J. O.

1981-01-01

It is explained that the tidal deformation of the earth's polar moment of inertia by the moon and sun cause periodic variations in rotation. The short period oscillations give rise to a meter-sized, diurnal signature in the lunar laser ranging data obtained at McDonald Observatory. A solution is given for the scale parameter k/C at fortnightly and monthly tidal frequencies. The results are compared with those obtained by other investigators and with a theoretical estimate which includes the effect of oceans and a decoupled fluid core.

Sample Handling Considerations for a Europa Sample Return Mission: An Overview

Science.gov (United States)

Fries, M. D.; Calaway, M. L.; Evans, C. A.; McCubbin, F. M.

2015-01-01

The intent of this abstract is to provide a basic overview of mission requirements for a generic Europan plume sample return mission, based on NASA Curation experience in NASA sample return missions ranging from Apollo to OSIRIS-REx. This should be useful for mission conception and early stage planning. We will break the mission down into Outbound and Return legs and discuss them separately.

A technique to detect periodic and non-periodic ultra-rapid flux time variations with standard radio-astronomical data

Science.gov (United States)

Borra, Ermanno F.; Romney, Jonathan D.; Trottier, Eric

2018-06-01

We demonstrate that extremely rapid and weak periodic and non-periodic signals can easily be detected by using the autocorrelation of intensity as a function of time. We use standard radio-astronomical observations that have artificial periodic and non-periodic signals generated by the electronics of terrestrial origin. The autocorrelation detects weak signals that have small amplitudes because it averages over long integration times. Another advantage is that it allows a direct visualization of the shape of the signals, while it is difficult to see the shape with a Fourier transform. Although Fourier transforms can also detect periodic signals, a novelty of this work is that we demonstrate another major advantage of the autocorrelation, that it can detect non-periodic signals while the Fourier transform cannot. Another major novelty of our work is that we use electric fields taken in a standard format with standard instrumentation at a radio observatory and therefore no specialized instrumentation is needed. Because the electric fields are sampled every 15.625 ns, they therefore allow detection of very rapid time variations. Notwithstanding the long integration times, the autocorrelation detects very rapid intensity variations as a function of time. The autocorrelation could also detect messages from Extraterrestrial Intelligence as non-periodic signals.

Comparison of POCIS passive samplers vs. composite water sampling: A case study.

Science.gov (United States)

Criquet, Justine; Dumoulin, David; Howsam, Michael; Mondamert, Leslie; Goossens, Jean-François; Prygiel, Jean; Billon, Gabriel

2017-12-31

The relevance of Polar Organic Chemical Integrative Samplers (POCIS) was evaluated for the assessment of concentrations of 46 pesticides and 19 pharmaceuticals in a small, peri-urban river with multi-origin inputs. Throughout the period of POCIS deployment, 24h-average water samples were collected automatically, and showed the rapid temporal evolution of concentrations of several micropollutants, as well as permitting the calculation of average concentrations in the water phase for comparison with those estimated from POCIS passive samplers. In the daily water samples, cyproconazol, epoxyconazol and imidacloprid showed high temporal variations with concentrations ranging from under the limit of detection up to several hundreds of ngL -1 . Erythromycin, cyprofloxacin and iopromide also increased rapidly up to tens of ngL -1 within a few days. Conversely, atrazine, caffeine, diclofenac, and to a lesser extent carbamazepine and sucralose, were systematically present in the water samples and showed limited variation in concentrations. For most of the substances studied here, the passive samplers gave reliable average concentrations between the minimal and maximal daily concentrations during the time of deployment. For pesticides, a relatively good correlation was clearly established (R 2 =0.89) between the concentrations obtained by POCIS and those gained from average water samples. A slight underestimation of the concentration by POCIS can be attributed to inappropriate sampling rates extracted from the literature and for our system, and new values are proposed. Considering the all data set, 75% of the results indicate a relatively good agreement between the POCIS and the average water samples concentration (values of the ratio ranging between 0,33 and 3). Note further that this agreement between these concentrations remains valid considering different sampling rates extracted from the literature. Copyright © 2017 Elsevier B.V. All rights reserved.

Quasi-periodic Fibonacci and periodic one-dimensional hypersonic phononic crystals of porous silicon: Experiment and simulation

Energy Technology Data Exchange (ETDEWEB)

Aliev, Gazi N., E-mail: g.aliev@bath.ac.uk; Goller, Bernhard [Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom)

2014-09-07

A one-dimensional Fibonacci phononic crystal and a distributed Bragg reflector were constructed from porous silicon. The structures had the same number of layers and similar acoustic impedance mismatch, and were electrochemically etched in highly boron doped silicon wafers. The thickness of the individual layers in the stacks was approximately 2 μm. Both types of hypersonic band gap structure were studied by direct measurement of the transmittance of longitudinal acoustic waves in the 0.1–2.6 GHz range. Acoustic band gaps deeper than 50 dB were detected in both structures. The experimental results were compared with model calculations employing the transfer matrix method. The acoustic properties of periodic and quasi-periodic structures in which half-wave retarding bi-layers do not consist of two quarter-wave retarding layers are discussed. The strong correlation between width and depth of gaps in the transmission spectra is demonstrated. The dominant mechanisms of acoustic losses in porous multilayer structures are discussed. The elastic constants remain proportional over our range of porosity, and hence, the Grüneisen parameter is constant. This simplifies the expression for the porosity dependence of the Akhiezer damping.

Detection and zoonotic potential of Trichinella spp. from free-range pig farming in Greece.

Science.gov (United States)

Papatsiros, V G; Boutsini, S; Ntousi, D; Stougiou, D; Mintza, D; Bisias, A

2012-06-01

Trichinellosis is a serious parasitic zoonosis, which is widely distributed around the world. Pork meat is still the predominant source of outbreaks of human trichinellosis in many countries. The aim of this study is to examine the impact of Trichinella spp. as an important risk factor on the free-range pig farming sector in Greece. In 2009, during routine testing for the detection of Trichinella larvae at slaughterhouses and the National Reference Laboratory for Parasites (NRL), a total of 826,426 pigs were tested with the magnetic stirrer method for Trichinella spp. at slaughterhouses, including 2,892 samples from free-range pigs. Two positive samples were detected: one positive for Trichinella britovi and one positive for Trichinella spp. (unspecified) in the samples from wild farmed free-range pigs. It is alarming that one of these cases was connected with clinical signs of trichinellosis in five persons of the same family in northeastern Greece, who consumed undercooked pork meat from a free-range pig farm. During 2010, a total number of 1,295,034 pigs were tested with same method, including 4,159 samples from free-range pig farms. Five positive samples for Trichinella spp. (unspecified) were detected from 4,159 free-range pigs tested by the Greek NRL. Moreover, 363 serum samples from free-range pigs were serologically tested with enzyme-linked immunosorbent assay (ELISA). Moreover, 363 serum samples from farmed free-range pigs were serologically tested with ELISA, and 15 samples were found positive. Finally, the present study is the first report of detection of T. britovi in Greece. In conclusion, based on the results of the present study, Trichinella spp. is a high-risk factor for the free-range pig farming in Greece.

The long-range correlation and evolution law of centennial-scale temperatures in Northeast China.

Science.gov (United States)

Zheng, Xiaohui; Lian, Yi; Wang, Qiguang

2018-01-01

This paper applies the detrended fluctuation analysis (DFA) method to investigate the long-range correlation of monthly mean temperatures from three typical measurement stations at Harbin, Changchun, and Shenyang in Northeast China from 1909 to 2014. The results reveal the memory characteristics of the climate system in this region. By comparing the temperatures from different time periods and investigating the variations of its scaling exponents at the three stations during these different time periods, we found that the monthly mean temperature has long-range correlation, which indicates that the temperature in Northeast China has long-term memory and good predictability. The monthly time series of temperatures over the past 106 years also shows good long-range correlation characteristics. These characteristics are also obviously observed in the annual mean temperature time series. Finally, we separated the centennial-length temperature time series into two time periods. These results reveal that the long-range correlations at the Harbin station over these two time periods have large variations, whereas no obvious variations are observed at the other two stations. This indicates that warming affects the regional climate system's predictability differently at different time periods. The research results can provide a quantitative reference point for regional climate predictability assessment and future climate model evaluation.

Effects of regrowth period, season and harvesting frequency on the ...

African Journals Online (AJOL)

Effects of regrowth period, season and harvesting frequency on the yield and nutritive value of Chloris gayana in the southern highlands of Tanzania. ... In vitro dry matter digestibility (IVDMD) and metabolisable energy (ME) declined faster with increasing periods of growth in the early than in the late wet season. ME ranged ...

Design and construction of an adiabatic calorimeter for samples of less than 1 cm3 in the temperature range T = 15 K to T = 350 K

International Nuclear Information System (INIS)

Lang, Brian E.; Boerio-Goates, Juliana; Woodfield, Brian F.

2006-01-01

A small-scale adiabatic calorimeter has been constructed as part of a larger project to study the thermodynamics of nanomaterials and to facilitate heat capacity measurements on samples of insufficient quantity to run on our current large-scale adiabatic apparatus. This calorimeter is designed to measure the heat capacity of samples whose volume is less than 0.8 cm 3 over a temperature range of T = 13 K to T = 350 K. Heat capacity results on copper, sapphire, and benzoic acid show the accuracy of the measurements to be better than ±0.4% for temperatures higher than T = 50 K. The reproducibility of these measurements is generally better than ±0.25%

Erosion of an ancient mountain range, the Great Smoky Mountains, North Carolina and Tennessee

Science.gov (United States)

Matmon, A.; Bierman, P.R.; Larsen, J.; Southworth, S.; Pavich, M.; Finkel, R.; Caffee, M.

2003-01-01

Analysis of 10Be and 26Al in bedrock (n=10), colluvium (n=5 including grain size splits), and alluvial sediments (n=59 including grain size splits), coupled with field observations and GIS analysis, suggest that erosion rates in the Great Smoky Mountains are controlled by subsurface bedrock erosion and diffusive slope processes. The results indicate rapid alluvial transport, minimal alluvial storage, and suggest that most of the cosmogenic nuclide inventory in sediments is accumulated while they are eroding from bedrock and traveling down hill slopes. Spatially homogeneous erosion rates of 25 - 30 mm Ky-1 are calculated throughout the Great Smoky Mountains using measured concentrations of cosmogenic 10Be and 26Al in quartz separated from alluvial sediment. 10Be and 26Al concentrations in sediments collected from headwater tributaries that have no upstream samples (n=18) are consistent with an average erosion rate of 28 ?? 8 mm Ky-1, similar to that of the outlet rivers (n=16, 24 ?? 6 mm Ky-1), which carry most of the sediment out of the mountain range. Grain-size-specific analysis of 6 alluvial sediment samples shows higher nuclide concentrations in smaller grain sizes than in larger ones. The difference in concentrations arises from the large elevation distribution of the source of the smaller grains compared with the narrow and relatively low source elevation of the large grains. Large sandstone clasts disaggregate into sand-size grains rapidly during weathering and downslope transport; thus, only clasts from the lower parts of slopes reach the streams. 26Al/10Be ratios do not suggest significant burial periods for our samples. However, alluvial samples have lower 26Al/10Be ratios than bedrock and colluvial samples, a trend consistent with a longer integrated cosmic ray exposure history that includes periods of burial during down-slope transport. The results confirm some of the basic ideas embedded in Davis' geographic cycle model, such as the reduction of relief

Residues of 2, 4-D in air samples from Saskatchewan: 1966-1975.

Science.gov (United States)

Grover, R; Kerr, L A; Wallace, K; Yoshida, K; Maybank, J

1976-01-01

Residues of 2,4-D (2,4-dichlorophenoxyacetic acid) in air samples from several sampling sites in central and southern Saskatchewan during the spraying seasons in the 1966-68 and 1970-75 periods were determined by gas-liquid chromatographic techniques. Initially, individual esters of 2,4-D were characterized by retention times and confirmed further by co-injection and dual column procedures. Since 1973, however, only total 2,4-D acid levels in air samples have been determined after esterification to the methyl ester and confirmed by gc/ms techniques whenever possible. Up to 50% of the daily samples collected during the spraying season at any of the locations and during any given year contained 2,4-D, with butyl esters being found most frequently. The daily 24-hr mean atmospheric concentrations of 2,4-D ranged from 0.01 to 1.22 mug/m3, 0.01 to 13.50 mug/m3, and 0.05 to 0.59 mug/m3 for the iso-propyl, mixed butyl and iso-octyl esters, respectively. Even when the samples were analysed for the total 2,4-D content, i.e. from 1973 onwards, the maximum level of the total acid reached only 23.14 mug/m3. In any given year and at any of the sampling sites, about 30% of the samples contained less than 0.01 mug/m3 of 2,4-D. In another 40% of the samples, the levels of 2,4-D ranged from 0.01 to 0.099 mug/m3. Only about 30% of the samples contained 2,4-D concentrations higher than 0.1 mug/m3, with only 10% or less exceeding 1 mug/m3. None of the samples, obtained with the high volume particulate sampler, showed any detectable levels of 2,4-D, indicating little or no transport of 2,4-D adsorbed on dust particles or as crystals of amine salts.

Lead pollution of shooting range soils | Sehube | South African ...

African Journals Online (AJOL)

Atotal of eight military shooting ranges were used for this study. Soil samples were collected at each of the eight shooting ranges at the berm, target line, 50 and 100 m from berm. In all of the shooting ranges investigated the highest total lead (Pb) concentrations were found in the bermsoils. Elevated Pb concentrations of 38 ...

Quasi-periodic luminosity variations in dwarf novae

International Nuclear Information System (INIS)

Robinson, E.L.; Nather, R.E.

1979-01-01

We have identified quasi-periodic oscillations in the light curves of five dwarf novae--U Gem, SS Cyg, RU Peg, KT Per, and VW Hyi-- and in the light curve of the quasi-periodic X-ray source Sco X-1. The mean periods of the quasi-periodic oscillations range from 32 s in SS Cyg to 147 s in KT Per and 165 s in Sco X-l. Their amplitudes are typically 0.005--0.0l mag. The properties of the quasi-periodic oscillations are represented well by a second-order autoregressive process. Use of this representation shows that the length of time over which the quasi-periodic oscillations maintain coherence is very short, typically 3--5 cycles of the oscillations. Thus the quasi-periodic oscillations can be distinguished from the short-period coherent oscillations in dwarf novae, which are usually interpreted as white dwarf pulsations, because t the periods of the quasi-periodic oscillations are 3--4 times longer and their coherence time is much shorter. The quasi-periodic oscillations occur in dwarf novae only during their eruptions and occur in Sco X-l only when the system is bright. The presence of the oscillations does not depend on the subclass to which a dwarf nova belongs or on the morphology of the individual eruptions. We argue that their short periods, their short coherence times, and their presence in Sco X-l require that the quasi-periodic oscillations be produced by the accretion disk, and not by the stars or by the boundary between the a accretion disk and its central star

Failure Probability Estimation Using Asymptotic Sampling and Its Dependence upon the Selected Sampling Scheme

Directory of Open Access Journals (Sweden)

Martinásková Magdalena

2017-12-01

Full Text Available The article examines the use of Asymptotic Sampling (AS for the estimation of failure probability. The AS algorithm requires samples of multidimensional Gaussian random vectors, which may be obtained by many alternative means that influence the performance of the AS method. Several reliability problems (test functions have been selected in order to test AS with various sampling schemes: (i Monte Carlo designs; (ii LHS designs optimized using the Periodic Audze-Eglājs (PAE criterion; (iii designs prepared using Sobol’ sequences. All results are compared with the exact failure probability value.

Periodic Boundary Conditions in the ALEGRA Finite Element Code

International Nuclear Information System (INIS)

Aidun, John B.; Robinson, Allen C.; Weatherby, Joe R.

1999-01-01

This document describes the implementation of periodic boundary conditions in the ALEGRA finite element code. ALEGRA is an arbitrary Lagrangian-Eulerian multi-physics code with both explicit and implicit numerical algorithms. The periodic boundary implementation requires a consistent set of boundary input sets which are used to describe virtual periodic regions. The implementation is noninvasive to the majority of the ALEGRA coding and is based on the distributed memory parallel framework in ALEGRA. The technique involves extending the ghost element concept for interprocessor boundary communications in ALEGRA to additionally support on- and off-processor periodic boundary communications. The user interface, algorithmic details and sample computations are given

Sample-based engine noise synthesis using an enhanced pitch-synchronous overlap-and-add method.

Science.gov (United States)

Jagla, Jan; Maillard, Julien; Martin, Nadine

2012-11-01

An algorithm for the real time synthesis of internal combustion engine noise is presented. Through the analysis of a recorded engine noise signal of continuously varying engine speed, a dataset of sound samples is extracted allowing the real time synthesis of the noise induced by arbitrary evolutions of engine speed. The sound samples are extracted from a recording spanning the entire engine speed range. Each sample is delimitated such as to contain the sound emitted during one cycle of the engine plus the necessary overlap to ensure smooth transitions during the synthesis. The proposed approach, an extension of the PSOLA method introduced for speech processing, takes advantage of the specific periodicity of engine noise signals to locate the extraction instants of the sound samples. During the synthesis stage, the sound samples corresponding to the target engine speed evolution are concatenated with an overlap and add algorithm. It is shown that this method produces high quality audio restitution with a low computational load. It is therefore well suited for real time applications.

Light Curve Periodic Variability of Cyg X-1 using Jurkevich Method

Indian Academy of Sciences (India)

The Jurkevich method is a useful method to explore periodicity in the unevenly sampled observational data. In this work, we adopted the method to the light curve of Cyg X-1 from 1996 to 2012, and found that there is an interesting period of 370 days, which appears in both low/hard and high/soft states. That period may be ...

Verification of the effects of Schumann frequency range electromagnetic fields on the human cardiovascular system

Science.gov (United States)

Tuzhilkin, D. A.; Borodin, A. S.

2017-11-01

The results of the study of variations in the electromagnetic background parameters of the Schumann resonator frequency range and the variability indices of the human heart period during its free activity are presented on the basis of 24-hour synchronous monitoring data. It is shown that the integral evaluation of the conjugacy of the heart rate variability indices from the Schumann resonance parameters is extremely weak. In this case, the differential evaluation of this dependence with separation into characteristic time intervals of the day, characterized by different motor activity of the subjects, becomes significantly higher. The number of volunteers whose conjugacy is characterized by a strong correlation in some cases reaches 35 percent of the sample.

Periodic and uniform nanogratings formed on cemented carbide by femtosecond laser scanning

International Nuclear Information System (INIS)

Lian, Yunsong; Deng, Jianxin; Xing, Youqiang; Lei, Shuting; Yu, Xiaoming

2013-01-01

Periodic and uniform nanogratings are fabricated by femtosecond laser scanning on cemented carbide. Specifically, three experiments are designed to study the influence of single pulse energy, scanning speed, and scanning spacing on the period and the uniformity of the formed nanogratings. The results show that the sample with single pulse energy of 2 μJ, scanning speed of 1000 μm/s, and scanning spacing of 5 μm shows the best quality of nanogratings among all the tested samples at different processing parameters. The uniformity of the nanogratings is largely determined by single pulse energy, scanning speed, and scanning spacing. Single pulse energy and scanning speed significantly affect the period of the nanogratings, whereas the period of the nanogratings maintains a fixed value under different scanning spacings. The period of the nanogratings increases gradually with the decrease of the single pulse energy and the increase of the scanning speed, respectively.

Studies on 129I and 14C in environmental samples by AMS

International Nuclear Information System (INIS)

Muramatsu, Yasuyuki

2010-01-01

and 127 I in soil were also studied. In order to know the secular variation of 14 C concentrations in the atmosphere, we have determined 14 C/ 12 C ratios in a Yaku cedar (age: 1632 year-old) from Yaku-Island (Kagoshima Prefecture, Japan), where there are many old cedar trees. Selected annual tree ring samples during 560-800 A.D. were used. In this period, there is very little data about secular variation of radiocarbon contents measured for Japanese samples. In the analysis, we have developed an apparatus (glass vacuum line) for purifying carbon from samples of single rings to make graphite targets for AMS. Using a small sample size (about 0.03g of cellulose sample), we could measure 14 C/ 12 C ratios with reasonable precision and accuracy by AMS at MALT, University of Tokyo. Results obtained in this study agreed with a 14 C pattern reported by IntCal04. However, if we see details, our data showed a wide range and a short term trend of the variation. This is because resolution of our data (single tree ring measurement) is higher than those of IntCal04 in which tree rings of ten years were combined. Around 700 A.D., Δ 14 C maximum is observed. It is interesting to note that there was a cold period around this age, suggesting possible relationships between the solar activity and the climate. Our data should also be useful in Japanese calibration data for the dating of archaeological findings in the above mentioned period. (author)

Unified Digital Periodic Signal Filters for Power Converter Systems

DEFF Research Database (Denmark)

Yang, Yongheng; Xin, Zhen; Zhou, Keliang

2017-01-01

Periodic signal controllers like repetitive and resonant controllers have demonstrated much potential in the control of power electronic converters, where periodic signals (e.g., ac voltages and currents) can be precisely regulated to follow references. Beyond the control of periodic signals, ac...... signal processing (e.g., in synchronization and pre-filtering) is also very important for power converter systems. Hence, this paper serves to unify digital periodic signal filters so as to maximize their roles in power converter systems (e.g., enhance the control of ac signals). The unified digital...... periodic signal filters behave like a comb filter, but it can also be configured to selectively filter out the harmonics of interest (e.g., the odd-order harmonics in single-phase power converter systems). Moreover, a virtual variable-sampling-frequency unit delay that enables frequency adaptive periodic...

Critical current measurements of high-temperature superconducting short samples at a wide range of temperatures and magnetic fields

Science.gov (United States)

Ma, Hongjun; Liu, Huajun; Liu, Fang; Zhang, Huahui; Ci, Lu; Shi, Yi; Lei, Lei

2018-01-01

High-Temperature Superconductors (HTS) are potential materials for high-field magnets, low-loss transmission cables, and Superconducting Magnetic Energy Storage (SMES) due to their high upper critical magnetic field (Hc2) and critical temperature (Tc). The critical current (Ic) of HTS, which is one of the most important parameters for superconductor application, depends strongly on the magnetic fields and temperatures. A new Ic measurement system that can carry out accurate Ic measurement for HTS short samples with various temperatures (4.2-80 K), magnetic fields (0-14 T), and angles of the magnetic field (0°-90°) has been developed. The Ic measurement system mainly consists of a measurement holder, temperature-control system, background magnet, test cryostat, data acquisition system, and DC power supply. The accuracy of temperature control is better than ±0.1 K over the 20-80 K range and ±0.05 K when measured below 20 K. The maximum current is over 1000 A with a measurement uncertainty of 1%. The system had been successfully used for YBa2Cu3O7-x(YBCO) tapes Ic determination with different temperatures and magnetic fields.

Critical current measurements of high-temperature superconducting short samples at a wide range of temperatures and magnetic fields.

Science.gov (United States)

Ma, Hongjun; Liu, Huajun; Liu, Fang; Zhang, Huahui; Ci, Lu; Shi, Yi; Lei, Lei

2018-01-01

High-Temperature Superconductors (HTS) are potential materials for high-field magnets, low-loss transmission cables, and Superconducting Magnetic Energy Storage (SMES) due to their high upper critical magnetic field (H c2 ) and critical temperature (T c ). The critical current (I c ) of HTS, which is one of the most important parameters for superconductor application, depends strongly on the magnetic fields and temperatures. A new I c measurement system that can carry out accurate I c measurement for HTS short samples with various temperatures (4.2-80 K), magnetic fields (0-14 T), and angles of the magnetic field (0°-90°) has been developed. The I c measurement system mainly consists of a measurement holder, temperature-control system, background magnet, test cryostat, data acquisition system, and DC power supply. The accuracy of temperature control is better than ±0.1 K over the 20-80 K range and ±0.05 K when measured below 20 K. The maximum current is over 1000 A with a measurement uncertainty of 1%. The system had been successfully used for YBa 2 Cu 3 O 7-x (YBCO) tapes I c determination with different temperatures and magnetic fields.

A novel small-period wiggler for free-electron lasers

International Nuclear Information System (INIS)

Feng Bibo; Wang Mingchang; Wang Zhijiang

1992-01-01

A novel small-period wiggler configuration constructed by sheet of bifilar-helix with ferro-core for free-electron lasers is proposed. The performance characteristics of the wiggler prototype with 10 mm period are measured. The field as high as 500 G to 1 kG have been obtained. The amplifier designs for operation at 190 GHz using modest electron beam energies in the range of 400-500 keV are presented

10.23  Mcps laser pseudo-code ranging system with 0.33  mm (1σ) pseudo-range measurement precision.

Science.gov (United States)

Yu, Xiaonan; Tong, Shoufeng; Zhang, Lei; Dong, Yan; Zhao, Xin; Qiao, Yue

2017-07-01

The inter-satellite laser link is the backbone of the next inter-satellite information network, and ranging and communication are the main functions of the inter-satellite laser link. This study focuses on the inter-satellite laser ranging based on the pseudo-code correlation technology. In this paper, several typical laser-ranging methods have been compared and we determined that the laser pseudo-code ranging architecture is more suitable for the inter-satellite laser communication link. The pseudo-code ranging system is easy to combine with a digital communication system, and we used it to calculate integer ambiguity by modulating the time information. The main challenge of the ranging system is range precision, which is the main focus of this paper. First, the framework of the pseudo-code ranging system is introduced; the ranging architecture of dual one-way ranging is used to eliminate the clock error between the two transceivers, and then the uncertainty of the phase detector is analyzed. In the analysis, the carrier to noise ratio and the ranging code rate are constrained by the laser communication link margin and the electronic hardware limitation. Therefore, the relationship between the sampling depth and the phase detector uncertainty is verified. A series of optical fiber channel laser pseudo-code ranging experiments demonstrated the effects of sampling depth on the ranging precision. By adjusting the depth of storage, such as the depth of 1.6 Mb, we obtained a pseudo-range measurement precision of 0.33 mm (1σ), which is equivalent to 0.0001 times code subdivision of 10.23 Mcps pseudo-code. This paper has achieved high precision in a pseudo-range measurements, which is the foundation of the inter-satellite laser link.

Periodic depuration of anthracene metabolites by rainbow trout

International Nuclear Information System (INIS)

Linder, G.; Bergman, H.L.

1984-01-01

Rainbow trout Salmo gairdneri, statically exposed to 36 μg/liter anthracene (including 9- 14 C-C anthracene), bioconcentrated the polynuclear aromatic hydrocarbon 200 times the exposure concentration over 18 hours. Then, during a 96-hour clearance periods, mass-balance analysis of fish and water samples indicated that anthracene was rapidly converted to polar metabolites(s), then eliminated periodically. Maximum depuration occurred during the dark phase of a 16-hour-light: 8-hour-dark photocycle. Of the 2-3% contribution of 14 C metabolites(s) to the total 14 C residue, nearly half came from the bile. This periodic depuration may be circadian, although this requires confirmation by further work; to the extent it affects metabolic fate of bioconcentrated organics, periodic depuration undoubtedly contributes to differences between predicted and observed bioconcentration factors

Prevalence and Characteristics of Salmonella Isolated from Free-Range Chickens in Shandong Province, China.

Science.gov (United States)

Zhao, Xiaonan; Gao, Yanxia; Ye, Chaoqun; Yang, Lingling; Wang, Tao; Chang, Weishan

2016-01-01

Compared with chickens raised in intensively managed breeding farms, free-range chickens in China are quite popular due to lower breeding density and less antibiotics usage. However, investigations about Salmonella enterica from free-range chickens are quite rare. The aim of the present study was to investigate prevalence and characteristics of Salmonella in free-range chickens in Shandong province, China. During the period of August and November 2015, 300 fresh fecal swabs from different broilers in three free-range chicken farms (100 samples per farm) were collected to isolate Salmonella , and then these isolates were subjected to serotyping, antibiotic sensitivity testing, enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR), and multilocus sequence typing (ST). A total of 38 Salmonella isolates (38/300, 12.7%) were recovered. The most common serotype was Enteritidis (81.6%), followed by Indiana (13.2%) and Typhimurium (5.3%). Twenty-two out of 38 isolates (57.9%) were resistant to ampicillin, the highest resistance rate, but resistance rates to cefazolin, cefotaxime, and ceftazidime were only 7.9%. The multidrug resistance (MDR) rate was 26.3%. Additionally, the Salmonella isolates could be classified into 25 genotypes by ERIC-PCR and were divided into three ST types (ST11, ST17, and ST19), with ST11 the highest isolation rate (81.6%). In summary, as with other poultry, free-ranging chickens may also serve as potential reservoir for antibiotic resistant Salmonella , thereby posing a threat to public health.

5 CFR 534.403 - SES rate range.

Science.gov (United States)

2010-01-01

... first day of the first applicable pay period beginning on or after January 1, 2004, the minimum rate of basic pay of the SES rate range is set at an amount equal to the minimum rate of basic pay under 5 U.S.C... Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER OTHER SYSTEMS Pay and...

Survival period after tube feeding in bedridden older patients.

Science.gov (United States)

Kosaka, Yoichi; Nakagawa-Satoh, Takuma; Ohrui, Takashi; Fujii, Masahiko; Arai, Hiroyuki; Sasaki, Hidetada

2012-04-01

We prospectively studied survival periods after tube feeding. Participants were 163 bedridden older patients suffering from dysphagia. A wide range of survival periods after tube feeding were observed within half a year without tube feeding after being bedridden. After this initial period, survival periods after tube feeding were limited to approximately half a year. Survival periods after tube feeding were positively proportional to the length of time patients were free from pneumonia after tube feeding. After tube feeding, patients died from pneumonia within half a year, and the frequency of pneumonia was 3.1 ± 2.7 times (mean ± SD) before death. Survival periods after tube feeding for less than 1 year were primarily determined by being bedridden for more than half a year without tube feeding and once pneumonia occurred; patients who were tube fed did not survive for more than half a year. © 2012 Japan Geriatrics Society.

Variable Sampling Composite Observer Based Frequency Locked Loop and its Application in Grid Connected System

Directory of Open Access Journals (Sweden)

ARUN, K.

2016-05-01

Full Text Available A modified digital signal processing procedure is described for the on-line estimation of DC, fundamental and harmonics of periodic signal. A frequency locked loop (FLL incorporated within the parallel structure of observers is proposed to accommodate a wide range of frequency drift. The error in frequency generated under drifting frequencies has been used for changing the sampling frequency of the composite observer, so that the number of samples per cycle of the periodic waveform remains constant. A standard coupled oscillator with automatic gain control is used as numerically controlled oscillator (NCO to generate the enabling pulses for the digital observer. The NCO gives an integer multiple of the fundamental frequency making it suitable for power quality applications. Another observer with DC and second harmonic blocks in the feedback path act as filter and reduces the double frequency content. A systematic study of the FLL is done and a method has been proposed to design the controller. The performance of FLL is validated through simulation and experimental studies. To illustrate applications of the new FLL, estimation of individual harmonics from nonlinear load and the design of a variable sampling resonant controller, for a single phase grid-connected inverter have been presented.

Selective loads periodization attenuates biochemical disturbances and enhances performance in female futsal players during competitive season

Directory of Open Access Journals (Sweden)

Ricelli Endrigo Ruppel da Rocha

2015-06-01

Full Text Available This study evaluated the effect of selective loads periodization on physical performance and biochemical parameters in professional female futsal players during competitive season. Twelve elite female futsal players from Kindermann team (Brazil participated in the study. Variables of physical performance and erythrogram, leukogram, plasma cortisol, plasma immunoglobulin A (IgA in the beginning of the preparatory period (PP, in the competitive period (CP and in the final competitive period (FCP were evaluated. Using selective loads periodization, all variables of physical performance increased (p < .01 during CP and were maintained during FCP (p < .05. White blood cells did not modify during CP and the increase of FCP in 28% remained within normal ranges. Plasma cortisol also increased during CP (p < .01 and was within the normal ranges during FCP. Plasma IgA also was within the normal ranges during CP and FCP. Selective loads periodization is adequate and attends the requirements of the sport during competitive season in female futsal players.

Megadontia, striae periodicity and patterns of enamel secretion in Plio-Pleistocene fossil hominins.

Science.gov (United States)

Lacruz, Rodrigo S; Dean, M Christopher; Ramirez-Rozzi, Fernando; Bromage, Timothy G

2008-08-01

Early hominins formed large and thick-enamelled cheek-teeth within relatively short growth periods as compared with modern humans. To understand better the developmental basis of this process, we measured daily enamel increments, or cross striations, in 17 molars of Plio-Pleistocene hominins representing seven different species, including specimens attributed to early Homo. Our results show considerable variation across species, although all specimens conformed to the known pattern characterised by greater values in outer than inner enamel, and greater cuspal than cervical values. We then compared our results with the megadontia index, which represents tooth size in relation to body mass, for each species to assess the effect of daily growth rates on tooth size. Our results indicate that larger toothed (megadont) taxa display higher rates or faster forming enamel than smaller toothed hominins. By forming enamel quickly, large tooth crowns were able to develop within the constraints of shorter growth periods. Besides daily increments, many animals express long-period markings (striae of Retzius) in their enamel. We report periodicity values (number of cross striations between adjacent striae) in 14 new specimens of Australopithecus afarensis, Paranthropus aethiopicus, Paranthropus boisei, Homo habilis, Homo rudolfensis and Homo erectus, and show that long-period striae express a strong association with male and average male-female body mass. Our results for Plio-Pleistocene hominins show that the biological rhythms that give rise to long-period striae are encompassed within the range of variation known for modern humans, but show a lower mean and modal value of 7 days in australopithecines. In our sample of early Homo, mean and modal periodicity values were 8 days, and therefore similar to modern humans. These new data on daily rates of enamel formation and periodicity provide a better framework to interpret surface manifestations of internal growth markings on

Daily self-sampling for high-risk human papillomavirus (HR-HPV) testing.

Science.gov (United States)

Sanner, Karin; Wikström, Ingrid; Gustavsson, Inger; Wilander, Erik; Lindberg, Julia Hedlund; Gyllensten, Ulf; Olovsson, Matts

2015-12-01

Self-sampling for HPV as part of primary screening is a well-tolerated method for women not attending organized Pap smear screening and could increase coverage of cervical cancer screening. To investigate if the prevalence of HR-HPV varies from day to day in infected women and if one single sample is reliable for detecting an ongoing infection. This is a prospective cohort study on 12 premenopausal and 13 postmenopausal women performing daily self-sampling for HR-HPV testing. They were all HR-HPV-positive 1-3 months ago. Postmenopausal women were sampled for 28 days and premenopausal women sampled during bleeding-free days in one menstrual cycle. A possible difference in viral load between the estrogen-dominated proliferative phase and the progesterone-dominated secretory phase was analyzed. Consistent results throughout the sampling period were observed for 19 women, with either a daily presence of HPV (14 women) or no HPV at all during the sampling period (5 women). Of 607 samples from 25 women, 596 were consistently positive or negative for HPV during the sampling period and 11 were inconsistent (2%). There was no difference in HPV copy number between the estrogen dominated proliferative or progesterone dominated secretory menstrual cycle phases. The major finding was a high degree of consistency concerning HR-HPV positivity and negativity of HR-HPV in vaginal fluid during a sustained period of daily self-sampling. It does not appear to matter whether the sample is collected in the proliferative or secretory phase. Copyright © 2015 Elsevier B.V. All rights reserved.

Long-range correlation and market segmentation in bond market

Science.gov (United States)

Wang, Zhongxing; Yan, Yan; Chen, Xiaosong

2017-09-01

This paper investigates the long-range auto-correlations and cross-correlations in bond market. Based on Detrended Moving Average (DMA) method, empirical results present a clear evidence of long-range persistence that exists in one year scale. The degree of long-range correlation related to maturities has an upward tendency with a peak in short term. These findings confirm the expectations of fractal market hypothesis (FMH). Furthermore, we have developed a method based on a complex network to study the long-range cross-correlation structure and applied it to our data, and found a clear pattern of market segmentation in the long run. We also detected the nature of long-range correlation in the sub-period 2007-2012 and 2011-2016. The result from our research shows that long-range auto-correlations are decreasing in the recent years while long-range cross-correlations are strengthening.

Th and U in the Paleozoic and Mesozoic systems of Kitakami range (preliminary report)

International Nuclear Information System (INIS)

Katada, Masato; Kanaya, Hiroshi; Sato, Choji.

1984-01-01

The research of Th and U in Kitakami range was commenced during the period of late 1950s and early 1960s. Following the exploration, the studies on Th and U in sedimentary rocks in Kitakami have been continued systematically. The data of Th and U covered whole Kitakami range by the addition of the newly obtained analytical data of northern part. The behaviors of Th and U during deposition and their contents in source rocks were studied by the analytical data. 75 samples of mudstone, sandstone, the matrix of conglomerate and limestone from south Kitakami, and 180 samples of mudstone, cherty clay stone, limestone, chert and green rock from northern part of Kitakami were analyzed. U/K 2 O ratio was constant regardless of the stratigraphy in the samples of southern Kitakami. This suggests that the major portion of U was initially dissolved in seawater, adsorbed by sericite, which is the only K 2 O -bearing mineral of sediment, and deposited. The values of Th and U in the sedimentary rocks in southern Kitakami were nearly the same as those of common sedimentary rocks in the world. It is supposed that the formation of K 2 O-bearing mineral was small, and the contents in source rocks affected. On the contrary, the Th values of sedimentary rocks in northern Kitakami, were higher than those of south, and it is supposed that this is attributable to the felsitic nature of source rocks. The mudstone of Matsumae, Hokkaido, differed from that of Kitakami, which means that they were not in same sedimentary basin. (Ishimitsu, A.)

Infinte Periodic Structure of Lightweight Elements

DEFF Research Database (Denmark)

Domadiya, Parthkumar Gandalal; Andersen, Lars Vabbersgaard; Sorokin, Sergey

2013-01-01

Lightweight wooden structures have become more popular as a sustainable, environmental- friendly and cost-effective alternative to concrete, steel and masonry buildings. However, there are certain drawbacks regarding noise and vibration due to the smaller weight and stiffness of wooden buildings....... Furthermore, lightweight building elements are typically periodic structures that behave as filters for sound propagation within certain frequency ranges (stop bands), thus only allowing transmission within the pass bands. Hence, traditional methods based on statistical energy analysis cannot be used...... for proper dynamic assessment of lightweight buildings. Instead, this paper discusses and compares the use of finite element analysis and a wave approach based on Floquet theory. The present analysis has focus on the effect of periodicity on vibration transmission within semi-infinite beam structures. Two...

The effects of size and period of administration of gold nanoparticles on rheological parameters of blood plasma of rats over a wide range of shear rates: In vivo

Directory of Open Access Journals (Sweden)

Abdelhalim Mohamed Anwar K

2011-10-01

Full Text Available Abstract Background Blood viscosity appears to be independent predictor of stroke, carotid intima-media thickening, atherosclerosis and most cardiovascular diseases. In an attempt to understand the toxicity and the potential threat of GNPs therapeutic and diagnostic use, an array of rheological parameters were performed to quantify the blood plasma response to different sizes and administration periods of GNPs over a wide range of shear rates. Methods Healthy, thirty male Wistar-Kyoto rats, 8-12 weeks old (approximately 250 g body weight were divided into control group (NG: n = 10, group 1 (G1A: intraperitoneal infusion of 10 nm GNPs for 3 days, n = 5 and G1B: intraperitoneal infusion of 10 nm GNPs for 7 days, n = 5, group 2 (G2A: intraperitoneal infusion of 50 nm GNPs for 3 days, n = 5 and G2B: intraperitoneal infusion of 50 nm GNPs for 7 days, n = 5. Dose of 100 μl of GNPs was administered to the animals via intraperitoneal injection. Blood samples of nearly 1 ml were obtained from each rat. Various rheological parameters such as torque, shear stress, shear rate, viscosity, plastic velocity, yield stress, consistency index (k and flow index (n were measured in the blood plasma of rats after the intraperitoneal administration of 10 and 50 nm GNP for 3 and 7 days using Brookfield LVDV-III Programmable rheometer. Results The relationship between shear stress and shear rate for control, G1A, G1B, G2A and G2B was linearly related. The plastic viscosity and the yield stress values for G1A, G1B, G2A and G2B significantly (p Conclusions At these particular shear rates, the estimated rheological parameters are not influenced by GNPs size and shape, number of NPs, surface area and administration period of GNPs. This study demonstrates that the highly decrease in blood plasma viscosity was accompanied with the smaller 10 nm GNPs compared with the 50 nm GNPs. The decrease in blood plasma viscosity induced with 10 and 50 nm GNPs may be attributed to

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

Directory of Open Access Journals (Sweden)

J. V. Niemi

2006-01-01

Full Text Available Aerosol samples were collected at a rural background site in southern Finland in May 2004 during pollution episode (PM1~16 µg m−3, backward air mass trajectories from south-east, intermediate period (PM1~5 µg m−3, backtrajectories from north-east and clean period (PM1~2 µg m−3, backtrajectories from north-west/north. The elemental composition, morphology and mixing state of individual aerosol particles in three size fractions were studied using transmission electron microscopy (TEM coupled with energy dispersive X-ray (EDX microanalyses. The TEM/EDX results were complemented with the size-segregated bulk chemical measurements of selected ions and organic and elemental carbon. Many of the particles in PM0.2–1 and PM1–3.3 size fractions were strongly internally mixed with S, C and/or N. The major particle types in PM0.2–1 samples were 1 soot and 2 (ammoniumsulphates and their mixtures with variable amounts of C, K, soot and/or other inclusions. Number proportions of those two particle groups in PM0.2–1 samples were 0–12% and 83–97%, respectively. During the pollution episode, the proportion of Ca-rich particles was very high (26–48% in the PM1–3.3 and PM3.3–11 samples, while the PM0.2–1 and PM1–3.3 samples contained elevated proportions of silicates (22–33%, metal oxides/hydroxides (1–9% and tar balls (1–4%. These aerosols originated mainly from polluted areas of Eastern Europe, and some open biomass burning smoke was also brought by long-range transport. During the clean period, when air masses arrived from the Arctic Ocean, PM1–3.3 samples contained mainly sea salt particles (67–89% with a variable rate of Cl substitution (mainly by NO3−. During the intermediate period, the PM1–3.3 sample contained porous (sponge-like Na-rich particles (35% with abundant S, K and O. They might originate from the burning of wood pulp wastes of paper industry. The proportion of biological particles and C-rich fragments

Generalized synthesis of periodic surfactant/inorganic composite materials

NARCIS (Netherlands)

Huo, Q.; Margolese, D.I.; Ciesla, U.; Feng, P.; Gier, T.E.; Sieger, P.; Leon, R.; Petroff, P.M.; Schüth, F.; Stucky, G.D.

1994-01-01

THE recent synthesis of silica-based mesoporous materials by the cooperative assembly of periodic inorganic and surfactant-based structures has attracted great interest because it extends the range of molecular-sieve materials into the very-large-pore regime. If the synthetic approach can be

Screening of IAEA environmental samples for fissile material content

International Nuclear Information System (INIS)

Hembree, Doyle M. Jr.; Carter, Joel A.; Devault, Gerald L.; Whitaker, J. Michael; Glasgow, David

2001-01-01

neutrons' because they are emitted after a brief decay period following irradiation. Counting these delayed neutrons provides a simple method for determining the total fissile content in the sample. Neutron activation analysis is a nuclear technique, which means that the chemical bonding environment of a fissile atom has no effect on the measurement process. Therefore, NAA is virtually immune to the 'matrix' effects that complicate other methods. As a result, environmental samples such as pine needles, water, soil, sediments, or swipes can all be rapidly analyzed with little or no sample preparation. All of the sources of error in the NAA-delayed neutron counting experiment are known and can be accounted for. In addition, the method is nondestructive and does not require the use of a blank measurement. The neutrons counted as a result of 239 Pu fission cannot be easily discriminated from those arising from 235 U. Therefore, the delayed neutron method proposed for sample screening will provide total fissile content; not the quantities of individual radionuclides. However, for most IAEA samples, it can be assumed that uranium is the predominant fissile material, and the method can be usefully employed for screening using this assumption (data collected from a large number of environmental samples supports this contention). The method is fast (∼5 minutes per sample), very sensitive (3-10 pg 235 U), and very accurate. An initial assessment of the NAA method was conducted using 35 swipe samples. The uranium results using thermal ionization mass spectrometry (TIMS) ranged from less than blank values to 332 ng/sample. The comparison of results between TIMS and NAA was quite favorable; the average percent difference between the two methods for the 35 samples was less than 5%. The accuracy, large dynamic range, speed, and low cost of the NAA-DN technique make the method an excellent choice for properly screening environmental samples. (author)

Multimedia Based on Scientific Approach for Periodic System of Element

Science.gov (United States)

Sari, S.; Aryana, D. M.; Subarkah, C. Z.; Ramdhani, M. A.

2018-01-01

This study aims to describe the application of interactive multimedia on the concept of the periodic system of elements. The study was conducted by using the one-shot case study design. The subjects in this study were 35 high school students of class XI IPA. Results showed that the stages of observing, questioning, data collecting (experimenting), and communicating are all considered very good. This shows that multimedia can assist students in explaining the development of the periodic system of elements, ranging from Triade doberrainer, Newland Octarchic Law, Mendeleyev, and the modern periodic, as well as atomic radius, ionization energy, and electronegativity of an element in the periodic system.

Pulsations of the Free Oscillations of the Earth in an Hourly Period Range

Science.gov (United States)

Sobolev, G. A.; Zakrzhevskaya, N. A.; Akatova, K. N.

2018-05-01

The records from 161 identical broadband seismic stations located in different regions of the world after the strong earthquakes off Sumatra Island on December 26, 2004 with magnitude M = 9.1, in Chile on February 27, 2010 with M = 8.8, and the Tohoku earthquake in Japan on March 11, 2011 with M = 9.0 are studied. Oscillations with a period of 11 h are analyzed. They are observed as pulsations in the free radial oscillations of the Earth lasting more than one week. The stations located a few hundred kilometers apart from each other demonstrate identical records. As the distance between the stations becomes larger, the structure of the records becomes different. At interstation distances of about 3800 km, the records at the stations have opposite phases, and at distances of 7600 km, the phases coincide. This is reflected in the spatial structure of the areas of the positive and negative phases of the oscillations on the Earth's surface. This structure recurs at the same time instant after the three considered earthquakes, which indicates that this effect is independent of the properties of the sources. The spatial positions of the areas of positive and negative phases are also not correlated to the geological conditions in the vicinity of the stations which are located both in the subduction zone and within the platform. The structure of the pulsations and their spatial distribution differ from the variations of the Earth's tides.

Exploring the Relationship between Family Functioning and Psycho-Pathology in a Sample in the Pediatric Age.

Science.gov (United States)

Pepe, Silvia; Tortolani, Daniela; Gentile, Simonetta; Di Ciommo, Vincenzo M

2015-03-17

The purpose of this study was to investigate differences in family functioning between families with clinical subjects in paediatric age and families taken from the Italian population. To this aim we used the Family Adaptability and Cohesion Evaluation Scale (FACES). Participants were children diagnosed with a psychopathology, recruited into the psychiatry department in a Paediatric Hospital of Rome. A total of 106 families participated in the study. The non-pathological sample is composed by 2,543 parents in different age periods of the life-cycle. Results showed significant differences in family functioning between pathological and non-pathological samples. Specifically, families from the pathological sample (particularly the ones who experienced eating disorders) were more frequently located in extreme or mid-range regions of Olson's circumplex model (p families in a clinical setting. Critical aspects and clinical applications are discussed.

Use of Atlantic Forest protected areas by free-ranging dogs: estimating abundance and persistence of use

Science.gov (United States)

Paschoal, Ana Maria; Massara, Rodrigo; Bailey, Larissa L.; Kendall, William L.; Doherty, Paul F.; Hirsch, Andre; Chiarello, Adriano; Paglia, Adriano

2016-01-01

Worldwide, domestic dogs (Canis familiaris) are one of the most common carnivoran species in natural areas and their populations are still increasing. Dogs have been shown to impact wildlife populations negatively, and their occurrence can alter the abundance, behavior, and activity patterns of native species. However, little is known about abundance and density of the free-ranging dogs that use protected areas. Here, we used camera trap data with an open-robust design mark–recapture model to estimate the number of dogs that used protected areas in Brazilian Atlantic Forest. We estimated the time period these dogs used the protected areas, and explored factors that influenced the probability of continued use (e.g., season, mammal richness, proportion of forest), while accounting for variation in detection probability. Dogs in the studied system were categorized as rural free-ranging, and their abundance varied widely across protected areas (0–73 individuals). Dogs used protected areas near human houses for longer periods (e.g., >50% of sampling occasions) compared to more distant areas. We found no evidence that their probability of continued use varied with season or mammal richness. Dog detection probability decreased linearly among occasions, possibly due to the owners confining their dogs after becoming aware of our presence. Comparing our estimates to those for native carnivoran, we found that dogs were three to 85 times more abundant than ocelots (Leopardus pardalis), two to 25 times more abundant than puma (Puma concolor), and approximately five times more abundant than the crab-eating fox (Cerdocyon thous). Combining camera trapping data with modern mark–recapture methods provides important demographic information on free-ranging dogs that can guide management strategies to directly control dogs' abundance and ranging behavior.

Periodicity-induced effects and method in vibro-acoustics

DEFF Research Database (Denmark)

Sorokin, Sergey V.

2014-01-01

of the lecture is to illustrate these issues in simple examples and to discuss possible applications and generalisations. First, the eigenfrequency spectra of finite periodic structures are compared with the location of stop-bands for their infinite counterparts. This is done with the special attention being...... of the lecture is concerned with the numerical implementation of the Floquet theory and the experimental demonstration of periodicity effects. A brief exposition of the Wave Finite Element method and an assessment of its validity range in canonical benchmark problems are presented. The results of experimental...

Autonomous water sampling for long-term monitoring of trace metals in remote environments.

Science.gov (United States)

Kim, Hyojin; Bishop, James K B; Wood, Todd J; Fung, Inez Y

2012-10-16

A remotely controlled autonomous method for long-term high-frequency sampling of environmental waters in remote locations is described. The method which preserves sample integrity of dissolved trace metals and major ions for month-long periods employs a gravitational filtration system (GFS) that separates dissolved and particulate phases as samples are collected. The key elements of GFS are (1) a modified "air-outlet" filter holder to maximize filtration rate and thus minimize filtration artifacts; and (2) the direct delivery of filtrate to dedicated bottle sets for specific analytes. Depth and screen filter types were evaluated with depth filters showing best performance. GFS performance is validated using ground, stream, and estuary waters. Over 30 days of storage, samples with GFS treatment had average recoveries of 95 ± 19% and 105 ± 7% of Fe and Mn, respectively; without GFS treatment, average recoveries were only 16% and 18%. Dissolved major cations K, Mg, and Na were stable independent of collection methodology, whereas Ca in some groundwater samples decreased up to 42% without GFS due to CaCO(3) precipitation. In-field performance of GFS equipped autosamplers is demonstrated using ground and streamwater samples collected at the Angelo Coast Range Reserve, California from October 3 to November 4 2011.

Are fish outside their usual ranges early indicators of climate-driven range shifts?

Science.gov (United States)

Fogarty, Hannah E; Burrows, Michael T; Pecl, Gretta T; Robinson, Lucy M; Poloczanska, Elvira S

2017-05-01

Shifts in species ranges are a global phenomenon, well known to occur in response to a changing climate. New species arriving in an area may become pest species, modify ecosystem structure, or represent challenges or opportunities for fisheries and recreation. Early detection of range shifts and prompt implementation of any appropriate management strategies is therefore crucial. This study investigates whether 'first sightings' of marine species outside their normal ranges could provide an early warning of impending climate-driven range shifts. We examine the relationships between first sightings and marine regions defined by patterns of local climate velocities (calculated on a 50-year timescale), while also considering the distribution of observational effort (i.e. number of sampling days recorded with biological observations in global databases). The marine trajectory regions include climate 'source' regions (areas lacking connections to warmer areas), 'corridor' regions (areas where moving isotherms converge), and 'sink' regions (areas where isotherms locally disappear). Additionally, we investigate the latitudinal band in which first sightings were recorded, and species' thermal affiliations. We found that first sightings are more likely to occur in climate sink and 'divergent' regions (areas where many rapid and diverging climate trajectories pass through) indicating a role of temperature in driving changes in marine species distributions. The majority of our fish first sightings appear to be tropical and subtropical species moving towards high latitudes, as would be expected in climate warming. Our results indicate that first sightings are likely related to longer-term climatic processes, and therefore have potential use to indicate likely climate-driven range shifts. The development of an approach to detect impending range shifts at an early stage will allow resource managers and researchers to better manage opportunities resulting from range

Effect of sample size on bias correction performance

Science.gov (United States)

Reiter, Philipp; Gutjahr, Oliver; Schefczyk, Lukas; Heinemann, Günther; Casper, Markus C.

2014-05-01

The output of climate models often shows a bias when compared to observed data, so that a preprocessing is necessary before using it as climate forcing in impact modeling (e.g. hydrology, species distribution). A common bias correction method is the quantile matching approach, which adapts the cumulative distribution function of the model output to the one of the observed data by means of a transfer function. Especially for precipitation we expect the bias correction performance to strongly depend on sample size, i.e. the length of the period used for calibration of the transfer function. We carry out experiments using the precipitation output of ten regional climate model (RCM) hindcast runs from the EU-ENSEMBLES project and the E-OBS observational dataset for the period 1961 to 2000. The 40 years are split into a 30 year calibration period and a 10 year validation period. In the first step, for each RCM transfer functions are set up cell-by-cell, using the complete 30 year calibration period. The derived transfer functions are applied to the validation period of the respective RCM precipitation output and the mean absolute errors in reference to the observational dataset are calculated. These values are treated as "best fit" for the respective RCM. In the next step, this procedure is redone using subperiods out of the 30 year calibration period. The lengths of these subperiods are reduced from 29 years down to a minimum of 1 year, only considering subperiods of consecutive years. This leads to an increasing number of repetitions for smaller sample sizes (e.g. 2 for a length of 29 years). In the last step, the mean absolute errors are statistically tested against the "best fit" of the respective RCM to compare the performances. In order to analyze if the intensity of the effect of sample size depends on the chosen correction method, four variations of the quantile matching approach (PTF, QUANT/eQM, gQM, GQM) are applied in this study. The experiments are further

Evolutionary dynamics of incubation periods.

Science.gov (United States)

Ottino-Loffler, Bertrand; Scott, Jacob G; Strogatz, Steven H

2017-12-21

The incubation period for typhoid, polio, measles, leukemia and many other diseases follows a right-skewed, approximately lognormal distribution. Although this pattern was discovered more than sixty years ago, it remains an open question to explain its ubiquity. Here, we propose an explanation based on evolutionary dynamics on graphs. For simple models of a mutant or pathogen invading a network-structured population of healthy cells, we show that skewed distributions of incubation periods emerge for a wide range of assumptions about invader fitness, competition dynamics, and network structure. The skewness stems from stochastic mechanisms associated with two classic problems in probability theory: the coupon collector and the random walk. Unlike previous explanations that rely crucially on heterogeneity, our results hold even for homogeneous populations. Thus, we predict that two equally healthy individuals subjected to equal doses of equally pathogenic agents may, by chance alone, show remarkably different time courses of disease.

A novel approach of periodate oxidation coupled with HPLC-FLD for the quantitative determination of 3-chloro-1,2-propanediol in water and vegetable oil.

Science.gov (United States)

Hu, Zhixiong; Cheng, Peng; Guo, Mingli; Zhang, Weinong; Qi, Yutang

2013-07-10

A novel approach of periodate oxidation coupled with high-performance liquid chromatography (HPLC)-fluorescence detection (FLD) for the quantitative determination of 3-chloro-1,2-propanediol (3-MCPD) has been established. The essence of this approach lies in the production of chloroacetaldehyde by the oxidization cleavage of 3-MCPD with sodium periodate and the HPLC analysis of chloroacetaldehyde monitored by an FLD detector after fluorescence derivatization with adenine. The experimental parameters relating to the efficiency of the derivative reaction such as concentration of adenine, chloroacetaldehyde reaction temperature, and time were studied. Under the optimized conditions, the proposed method can provide high sensitivity, good linearity (r(2) = 0.999), and repeatability (percent relative standard deviations between 2.57% and 3.44%), the limits of detection and quantification were 0.36 and 1.20 ng/mL, respectively, and the recoveries obtained for water samples were in the range 93.39-97.39%. This method has been successfully applied to the analysis of real water samples. Also this method has been successfully used for the analysis of vegetable oil samples after pretreatment with liquid-liquid extraction; the recoveries obtained by a spiking experiment with soybean oil ranged from 96.27% to 102.42%. In comparison with gas chromatography or gas chromatography-mass spectrometry, the proposed method can provide the advantages of simple instrumental requirement, easy operation, low cost, and high efficiency, thus making this approach another good choice for the sensitive determination of 3-MCPD.

Nonadiabatic transition path sampling

International Nuclear Information System (INIS)

Sherman, M. C.; Corcelli, S. A.

2016-01-01

Fewest-switches surface hopping (FSSH) is combined with transition path sampling (TPS) to produce a new method called nonadiabatic path sampling (NAPS). The NAPS method is validated on a model electron transfer system coupled to a Langevin bath. Numerically exact rate constants are computed using the reactive flux (RF) method over a broad range of solvent frictions that span from the energy diffusion (low friction) regime to the spatial diffusion (high friction) regime. The NAPS method is shown to quantitatively reproduce the RF benchmark rate constants over the full range of solvent friction. Integrating FSSH within the TPS framework expands the applicability of both approaches and creates a new method that will be helpful in determining detailed mechanisms for nonadiabatic reactions in the condensed-phase.

Effect of sampling site, repeated sampling, pH, and PCO2 on plasma lactate concentration in healthy dogs.

Science.gov (United States)

Hughes, D; Rozanski, E R; Shofer, F S; Laster, L L; Drobatz, K J

1999-04-01

To characterize the variation in plasma lactate concentration among samples from commonly used blood sampling sites in conscious, healthy dogs. 60 healthy dogs. Cross-sectional study using a replicated Latin square design. Each dog was assigned to 1 of 6 groups (n = 10) representing all possible orders for 3 sites (cephalic vein, jugular vein, and femoral artery) used to obtain blood. Samples were analyzed immediately, by use of direct amperometry for pH, PO2, Pco2, glucose, and lactate concentration. Significant differences in plasma lactate concentrations were detected among blood samples from the cephalic vein (highest), femoral artery, and jugular vein (lowest). Mean plasma lactate concentration in the first sample obtained, irrespective of sampling site, was lower than in subsequent samples. Covariation was identified among plasma lactate concentration, pH, and PCO2, but correlation coefficients were low. Plasma lactate concentrations differed among blood samples from various sites. A reference range for plasma lactate concentration was 0.3 to 2.5 mmol/L. Differences in plasma lactate concentrations among samples from various sites and with repeated sampling, in healthy dogs, are small. Use of the reference range may facilitate the clinical use of plasma lactate concentration in dogs.

Level and origin of {sup 129}I and {sup 137}Cs in lichen samples (Cladonia alpestris) in central Sweden

Energy Technology Data Exchange (ETDEWEB)

Gomez-Guzman, J.M., E-mail: jm_gomez@us.e [Centro Nacional de Aceleradores (CNA), Accelerator Mass Spectrometry Unit, Avd. Tomas Alva Edison 7, Isla de Cartuja, Seville 41092 (Spain); Lopez-Gutierrez, J.M. [Centro Nacional de Aceleradores (CNA), Accelerator Mass Spectrometry Unit, Avd. Tomas Alva Edison 7, Isla de Cartuja, Seville 41092 (Spain); Department of Applied Physics, University of Seville, C. Virgen de Africa 7, Seville 41011 (Spain); Holm, E. [Norwegian Radiation Protection Authority, Grini Naearingspark 13, P.O. Box 55, 1332 Osteras (Norway); Pinto-Gomez, A.R. [Centro Nacional de Aceleradores (CNA), Accelerator Mass Spectrometry Unit, Avd. Tomas Alva Edison 7, Isla de Cartuja, Seville 41092 (Spain)

2011-02-15

Lichen is a symbiosis between algae and fungi. They have for decades been used as bioindicators for atmospheric deposition of heavy metals, organic compounds and radioactive elements. Especially the species Cladonia alpestris and Cladonia rangiferina are important for the food chain lichen-reindeer-man. The concentration of {sup 129}I was determined in lichen samples (Cladonia alpestris) contaminated by fallout from atmospheric nuclear tests explosions and the Chernobyl accident. The samples were collected at Lake Rogen District (62.3{sup o}N, 12.4{sup o}E) in central Sweden in the periods 1961-1975 and 1987-1998, and analysed with accelerator mass spectrometry (AMS) at CNA (Seville) to study its distribution in different layers. Data on the {sup 137}Cs activity measured previously were also included in this study. The {sup 129}I concentration ranged from (0.95 {+-} 0.13) x 10{sup 8} at g{sup -1} in 1961 in the uppermost layer to (14.2 {+-} 0.5) x 10{sup 8} at g{sup -1} in 1987 in deepest layer. The {sup 129}I/{sup 137}Cs atom ratio ranged between 0.12 and 0.27 for lichen samples collected in the period 1961-1975, indicating weapons tests fallout. For lichen samples collected between 1987 and 1998 the behaviour of {sup 137}Cs concentrations reflected Chernobyl fallout. The concentrations of the two radionuclides followed each other quite well in the profile, reflecting the same origin for both. From the point of view of the spatial distribution in the lichen, it appears that {sup 129}I was predominantly accumulated in the lowest layer, the opposite to {sup 137}Cs for which the highest amounts were detected systematically in the topmost layer of lichen. This vertical distribution is important for radioecology because lichen is the initial link in the food chain lichen-reindeer-man, and reindeer only graze the upper parts of lichen carpets. - Research highlights: {yields} This work shows the results for {sup 129}I in lichens collected in 1961-1975 and 1987

Spatial Sampling of Weather Data for Regional Crop Yield Simulations

Science.gov (United States)

Van Bussel, Lenny G. J.; Ewert, Frank; Zhao, Gang; Hoffmann, Holger; Enders, Andreas; Wallach, Daniel; Asseng, Senthold; Baigorria, Guillermo A.; Basso, Bruno; Biernath, Christian;

Scheduling sampling to maximize information about time dependence in experiments with limited resources

DEFF Research Database (Denmark)

Græsbøll, Kaare; Christiansen, Lasse Engbo

2013-01-01

Looking for periodicity in sampled data requires that periods (lags) of different length are represented in the sampling plan. We here present a method to assist in planning of temporal studies with sparse resources, which optimizes the number of observed time lags for a fixed amount of samples w...

Specified assurance level sampling procedure

International Nuclear Information System (INIS)

Willner, O.

1980-11-01

In the nuclear industry design specifications for certain quality characteristics require that the final product be inspected by a sampling plan which can demonstrate product conformance to stated assurance levels. The Specified Assurance Level (SAL) Sampling Procedure has been developed to permit the direct selection of attribute sampling plans which can meet commonly used assurance levels. The SAL procedure contains sampling plans which yield the minimum sample size at stated assurance levels. The SAL procedure also provides sampling plans with acceptance numbers ranging from 0 to 10, thus, making available to the user a wide choice of plans all designed to comply with a stated assurance level

Comparison of Spot and Time Weighted Averaging (TWA Sampling with SPME-GC/MS Methods for Trihalomethane (THM Analysis

Directory of Open Access Journals (Sweden)

Don-Roger Parkinson

2016-02-01

Full Text Available Water samples were collected and analyzed for conductivity, pH, temperature and trihalomethanes (THMs during the fall of 2014 at two monitored municipal drinking water source ponds. Both spot (or grab and time weighted average (TWA sampling methods were assessed over the same two day sampling time period. For spot sampling, replicate samples were taken at each site and analyzed within 12 h of sampling by both Headspace (HS- and direct (DI- solid phase microextraction (SPME sampling/extraction methods followed by Gas Chromatography/Mass Spectrometry (GC/MS. For TWA, a two day passive on-site TWA sampling was carried out at the same sampling points in the ponds. All SPME sampling methods undertaken used a 65-µm PDMS/DVB SPME fiber, which was found optimal for THM sampling. Sampling conditions were optimized in the laboratory using calibration standards of chloroform, bromoform, bromodichloromethane, dibromochloromethane, 1,2-dibromoethane and 1,2-dichloroethane, prepared in aqueous solutions from analytical grade samples. Calibration curves for all methods with R2 values ranging from 0.985–0.998 (N = 5 over the quantitation linear range of 3–800 ppb were achieved. The different sampling methods were compared for quantification of the water samples, and results showed that DI- and TWA- sampling methods gave better data and analytical metrics. Addition of 10% wt./vol. of (NH42SO4 salt to the sampling vial was found to aid extraction of THMs by increasing GC peaks areas by about 10%, which resulted in lower detection limits for all techniques studied. However, for on-site TWA analysis of THMs in natural waters, the calibration standard(s ionic strength conditions, must be carefully matched to natural water conditions to properly quantitate THM concentrations. The data obtained from the TWA method may better reflect actual natural water conditions.

Do women's voices provide cues of the likelihood of ovulation? The importance of sampling regime.

Directory of Open Access Journals (Sweden)

Julia Fischer

Full Text Available The human voice provides a rich source of information about individual attributes such as body size, developmental stability and emotional state. Moreover, there is evidence that female voice characteristics change across the menstrual cycle. A previous study reported that women speak with higher fundamental frequency (F0 in the high-fertility compared to the low-fertility phase. To gain further insights into the mechanisms underlying this variation in perceived attractiveness and the relationship between vocal quality and the timing of ovulation, we combined hormone measurements and acoustic analyses, to characterize voice changes on a day-to-day basis throughout the menstrual cycle. Voice characteristics were measured from free speech as well as sustained vowels. In addition, we asked men to rate vocal attractiveness from selected samples. The free speech samples revealed marginally significant variation in F0 with an increase prior to and a distinct drop during ovulation. Overall variation throughout the cycle, however, precluded unequivocal identification of the period with the highest conception risk. The analysis of vowel samples revealed a significant increase in degree of unvoiceness and noise-to-harmonic ratio during menstruation, possibly related to an increase in tissue water content. Neither estrogen nor progestogen levels predicted the observed changes in acoustic characteristics. The perceptual experiments revealed a preference by males for voice samples recorded during the pre-ovulatory period compared to other periods in the cycle. While overall we confirm earlier findings in that women speak with a higher and more variable fundamental frequency just prior to ovulation, the present study highlights the importance of taking the full range of variation into account before drawing conclusions about the value of these cues for the detection of ovulation.

Improved optical ranging for space based gravitational wave detection

International Nuclear Information System (INIS)

Sutton, Andrew J; Shaddock, Daniel A; McKenzie, Kirk; Ware, Brent; De Vine, Glenn; Spero, Robert E; Klipstein, W

2013-01-01

The operation of 10 6  km scale laser interferometers in space will permit the detection of gravitational waves at previously unaccessible frequency regions. Multi-spacecraft missions, such as the Laser Interferometer Space Antenna (LISA), will use time delay interferometry to suppress the otherwise dominant laser frequency noise from their measurements. This is accomplished by performing sub-sample interpolation of the optical phase measurements recorded at each spacecraft for synchronization and cancellation of the otherwise dominant laser frequency noise. These sub-sample interpolation time shifts are dependent upon the inter-spacecraft range and will be measured using a pseudo-random noise ranging modulation upon the science laser. One limit to the ranging performance is mutual interference between the outgoing and incoming ranging signals upon each spacecraft. This paper reports on the demonstration of a noise cancellation algorithm which is shown to providing a factor of ∼8 suppression of the mutual interference noise. Demonstration of the algorithm in an optical test bed showed an rms ranging error of 0.06 m, improved from 0.19 m in previous results, surpassing the 1 m RMS LISA specification and potentially improving the cancellation of laser frequency noise. (paper)

The isotopic composition of methane in the stratosphere: high-altitude balloon sample measurements

Directory of Open Access Journals (Sweden)

T. Röckmann

2011-12-01

Full Text Available The isotopic composition of stratospheric methane has been determined on a large suite of air samples from stratospheric balloon flights covering subtropical to polar latitudes and a time period of 16 yr. 154 samples were analyzed for δ¹³C and 119 samples for δD, increasing the previously published dataset for balloon borne samples by an order of magnitude, and more than doubling the total available stratospheric data (including aircraft samples published to date. The samples also cover a large range in mixing ratio from tropospheric values near 1800 ppb down to only 250 ppb, and the strong isotope fractionation processes accordingly increase the isotopic composition up to δ¹³C = −14‰ and δD = +190‰, the largest enrichments observed for atmospheric CH₄ so far. When analyzing and comparing kinetic isotope effects (KIEs derived from single balloon profiles, it is necessary to take into account the residence time in the stratosphere in combination with the observed mixing ratio and isotope trends in the troposphere, and the range of isotope values covered by the individual profile. The isotopic composition of CH₄ in the stratosphere is affected by both chemical and dynamical processes. This severely hampers interpretation of the data in terms of the relative fractions of the three important sink mechanisms (reaction with OH, O(¹D and Cl. It is shown that a formal sink partitioning using the measured data severely underestimates the fraction removed by OH, which is likely due to the insensitivity of the measurements to the kinetic fractionation in the lower stratosphere. Full quantitative interpretation of the CH₄ isotope data in terms of the three sink reactions requires a global model.

Antimicrobial-resistant Klebsiella species isolated from free-range chicken samples in an informal settlement.

Science.gov (United States)

Fielding, Burtram C; Mnabisa, Amanda; Gouws, Pieter A; Morris, Thureyah

2012-02-29

Sub-therapeutic doses of antimicrobial agents are administered routinely to poultry to aid growth and to prevent disease, with prolonged exposure often resulting in bacterial resistance. Crossover of antibiotic resistant bacteria from poultry to humans poses a risk to human health. In this study, 17 chicken samples collected from a vendor operating in an informal settlement in the Cape Town Metropolitan area, South Africa were screened for antimicrobial-resistant Gram-negative bacilli using the Kirby Bauer disk diffusion assay. IN TOTAL, SIX ANTIBIOTICS WERE SCREENED: ampicillin, ciprofloxacin, gentamicin, nalidixic acid, tetracycline and trimethoprim. Surprisingly, Klebsiella ozaenae was identified in 96 and K. rhinoscleromatis in 6 (n=102) of the samples tested. Interestingly, ∼40% of the isolated Klebsiella spp. showed multiple resistance to at least three of the six antibiotics tested. Klebsiella ozaenae and K. rhinoscleromatis cause clinical chronic rhinitis and are almost exclusively associated with people living in areas of poor hygiene.

Digital reactor period meter type of NSSG-7

Energy Technology Data Exchange (ETDEWEB)

Glowacki, S W

1981-01-01

The paper presents the idea and electronic circuits of the Digital Reactor Period Meter. The instrument consists of a neutron ionisation chamber, the amplifier logarithming the output chamber current, the circuit taking two samples of the log amplifier output signal and subtracting them, the analog -to -digital dividing circuit and the scaler providing the final information of the reactor period value in seconds and in the digital form. Besides it, the instrument produces the acoustic signal in the case, when the rise-time of neutron flux exceeds the permitted value. The untypical construction of the reactor period meter has been developed to obtain both good measurement accuracy and the resistance against the electromagnetic background pulses interfering with the measuring process. The applied measuring system has been patented.

Mounting Thin Samples For Electrical Measurements

Science.gov (United States)

Matus, L. G.; Summers, R. L.

1988-01-01

New method for mounting thin sample for electrical measurements involves use of vacuum chuck to hold a ceramic mounting plate, which holds sample. Contacts on mounting plate establish electrical connection to sample. Used to make electrical measurements over temperature range from 77 to 1,000 K and does not introduce distortions into magnetic field during Hall measurements.

Electromagnetic Radiation of Electrons in Periodic Structures

CERN Document Server

Potylitsyn, Alexander Petrovich

2011-01-01

Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation a...

Parameters influencing the variation in mercury emissions from an Alberta power plant burning high inertinite coal over thirty-eight weeks period

Energy Technology Data Exchange (ETDEWEB)

Goodarzi, F.; Reyes, J. [Environmental Studies, Geological Survey of Canada-Calgary, 3303-33rd Street N.W., Calgary, Alberta (Canada T2L 2A7); Schulz, J.; Hollman, D. [EPCOR 10065 Jasper Ave Edmonton, Alberta (Canada T5J 3B1); Rose, D. [Air Pollution Prevention Directorate Environment Canada, 315 St-Joseph Blvd Hull, Quebec (Canada K1A 0H3)

2006-01-03

Feed coals and fly ashes from a coal-fired power station burning Alberta subbituminous coal were examined for a period of thirty-eight weeks to determine the variation in emitted mercury. Feed coal samples were analyzed for proximate, calorific value and Hg content, while fly ash samples were examined for C and Hg contents. The maceral content of the feed coal was also determined. The emitted mercury was calculated and compared to mercury emitted from the stack according to a mass-balance calculation from a previous study for the same station. Mercury contents ranged from 0.029 to 0.066 mg/kg for feed coal, and from 0.069 to 0.112 mg/kg for fly ash. The carbon/char in fly ash was separated into reactive (vitrinitic/bimacerate) and less reactive (inertinitic) chars using ZnBr{sub 2} at specific gravities of 1.7, 2.0, and 2.25 to 2.4. The result shows that there is a positive correlation between the carbon and mercury content of the fly ash. The reactive char particles in the fly ash may be responsible for the capture mercury in fly ash. The percentage of estimated captured mercury by fly ash increases with increasing carbon content (%) in fly ash. The percentage of emitted mercury for the period of 38 weeks is estimated to be within the range of 49% to 76% of the total input of mercury. (author)

Integrated sampling vs ion chromatography: Mathematical considerations

International Nuclear Information System (INIS)

Sundberg, L.L.

1992-01-01

This paper presents some general purpose considerations that can be utilized when comparisons are made between the results of integrated sampling over several hours or days, and ion chromatography where sample collection times are measured in minutes. The discussion is geared toward the measurement of soluble transition metal ions in BWR feedwater. Under steady-state conditions, the concentrations reported by both techniques should be in reasonable agreement. Transient operations effect both types of measurements. A simplistic model, applicable to both sampling techniques, is presented that demonstrates the effect of transients which occur during the acquisition of a steady-state sample. For a common set of conditions, the integrated concentration is proportional to the concentration and duration of the transient, and inversely proportional to the sample collection time. The adjustment of the collection period during a known transient allows an estimation of peak transient concentration. Though the probability of sampling a random transient with the integrated sampling technique is very high, the magnitude is severely diluted with long integration times. Transient concentrations are magnified with ion chromatography, but the probability of sampling a transient is significantly lower using normal ion chromatography operations. Various data averaging techniques are discussed for integrated sampling and IC determinations. The use of time-weighted averages appears to offer more advantages over arithmetic and geometric means for integrated sampling when the collection period is variable. For replicate steady-state ion chromatography determinations which bracket a transient sample, it may be advantageous to ignore the calculation of averages, and report the data as trending information only

Aerobot Sampling and Handling System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Honeybee Robotics proposes to: ?Derive and document the functional and technical requirements for Aerobot surface sampling and sample handling across a range of...

Effect of Myostatin SNP on muscle fiber properties in male Thoroughbred horses during training period.

Science.gov (United States)

Miyata, Hirofumi; Itoh, Rika; Sato, Fumio; Takebe, Naoya; Hada, Tetsuro; Tozaki, Teruaki

2017-10-20

Variants of the Myostatin gene have been shown to have an influence on muscle hypertrophy phenotypes in a wide range of mammalian species. Recently, a Thoroughbred horse with a C-Allele at the g.66493737C/T single-nucleotide polymorphism (SNP) has been reported to be suited to short-distance racing. In this study, we examined the effect of the Myostatin SNP on muscle fiber properties in young Thoroughbred horses during a training period. To investigate the effect of the Myostatin SNP on muscle fiber before training, several mRNA expressions were relatively quantified in biopsy samples from the middle gluteal muscle of 27 untrained male Thoroughbred horses (1.5 years old) using real-time RT-PCR analysis. The remaining muscle samples were used for immunohistochemical analysis to determine the population and area of each fiber type. All measurements were revaluated in biopsy samples of the same horses after a 5-month period of conventional training. Although the expressions of Myostatin mRNA decreased in all SNP genotypes, a significant decrease was found in only the C/C genotype after training. While, expression of VEGFa, PGC1α, and SDHa mRNAs, which relate to the biogenesis of mitochondria and capillaries, was significantly higher (54-82%) in the T/T than the C/C genotypes after training. It is suggested that hypertrophy of muscle fiber is directly associated with a decrease in Myostatin mRNA expression in the C/C genotype, and that increased expressions of VEGFa, PGC1α, and SDHa in the T/T genotype might be indirectly caused by the Myostatin SNP.

Ultrafast optical ranging using microresonator soliton frequency combs

Science.gov (United States)

Trocha, P.; Karpov, M.; Ganin, D.; Pfeiffer, M. H. P.; Kordts, A.; Wolf, S.; Krockenberger, J.; Marin-Palomo, P.; Weimann, C.; Randel, S.; Freude, W.; Kippenberg, T. J.; Koos, C.

2018-02-01

Light detection and ranging is widely used in science and industry. Over the past decade, optical frequency combs were shown to offer advantages in optical ranging, enabling fast distance acquisition with high accuracy. Driven by emerging high-volume applications such as industrial sensing, drone navigation, or autonomous driving, there is now a growing demand for compact ranging systems. Here, we show that soliton Kerr comb generation in integrated silicon nitride microresonators provides a route to high-performance chip-scale ranging systems. We demonstrate dual-comb distance measurements with Allan deviations down to 12 nanometers at averaging times of 13 microseconds along with ultrafast ranging at acquisition rates of 100 megahertz, allowing for in-flight sampling of gun projectiles moving at 150 meters per second. Combining integrated soliton-comb ranging systems with chip-scale nanophotonic phased arrays could enable compact ultrafast ranging systems for emerging mass applications.

Tree range expansion in eastern North America fails to keep pace with climate warming at northern range limits.

Science.gov (United States)

Sittaro, Fabian; Paquette, Alain; Messier, Christian; Nock, Charles A

2017-08-01

Rising global temperatures are suggested to be drivers of shifts in tree species ranges. The resulting changes in community composition may negatively impact forest ecosystem function. However, long-term shifts in tree species ranges remain poorly documented. We test for shifts in the northern range limits of 16 temperate tree species in Quebec, Canada, using forest inventory data spanning three decades, 15° of longitude and 7° of latitude. Range shifts were correlated with climate warming and dispersal traits to understand potential mechanisms underlying changes. Shifts were calculated as the change in the 95th percentile of latitudinal occurrence between two inventory periods (1970-1978, 2000-2012) and for two life stages: saplings and adults. We also examined sapling and adult range offsets within each inventory, and changes in the offset through time. Tree species ranges shifted predominantly northward, although species responses varied. As expected shifts were greater for tree saplings, 0.34 km yr -1 , than for adults, 0.13 km yr -1 . Range limits were generally further north for adults compared to saplings, but the difference diminished through time, consistent with patterns observed for range shifts within each life stage. This suggests caution should be exercised when interpreting geographic range offsets between life stages as evidence of range shifts in the absence of temporal data. Species latitudinal velocities were on average climate change and were mostly unrelated to dispersal traits. Finally, our results add to the body of evidence suggesting tree species are mostly limited in their capacity to track climate warming, supporting concerns that warming will negatively impact the functioning of forest ecosystems. © 2017 John Wiley & Sons Ltd.

Empirical mode decomposition and long-range correlation analysis of sunspot time series

International Nuclear Information System (INIS)

Zhou, Yu; Leung, Yee

2010-01-01

Sunspots, which are the best known and most variable features of the solar surface, affect our planet in many ways. The number of sunspots during a period of time is highly variable and arouses strong research interest. When multifractal detrended fluctuation analysis (MF-DFA) is employed to study the fractal properties and long-range correlation of the sunspot series, some spurious crossover points might appear because of the periodic and quasi-periodic trends in the series. However many cycles of solar activities can be reflected by the sunspot time series. The 11-year cycle is perhaps the most famous cycle of the sunspot activity. These cycles pose problems for the investigation of the scaling behavior of sunspot time series. Using different methods to handle the 11-year cycle generally creates totally different results. Using MF-DFA, Movahed and co-workers employed Fourier truncation to deal with the 11-year cycle and found that the series is long-range anti-correlated with a Hurst exponent, H, of about 0.12. However, Hu and co-workers proposed an adaptive detrending method for the MF-DFA and discovered long-range correlation characterized by H≈0.74. In an attempt to get to the bottom of the problem in the present paper, empirical mode decomposition (EMD), a data-driven adaptive method, is applied to first extract the components with different dominant frequencies. MF-DFA is then employed to study the long-range correlation of the sunspot time series under the influence of these components. On removing the effects of these periods, the natural long-range correlation of the sunspot time series can be revealed. With the removal of the 11-year cycle, a crossover point located at around 60 months is discovered to be a reasonable point separating two different time scale ranges, H≈0.72 and H≈1.49. And on removing all cycles longer than 11 years, we have H≈0.69 and H≈0.28. The three cycle-removing methods—Fourier truncation, adaptive detrending and the

Long-range dependence and sea level forecasting

CERN Document Server

Ercan, Ali; Abbasov, Rovshan K

2013-01-01

This study shows that the Caspian Sea level time series possess long range dependence even after removing linear trends, based on analyses of the Hurst statistic, the sample autocorrelation functions, and the periodogram of the series. Forecasting performance of ARMA, ARIMA, ARFIMA and Trend Line-ARFIMA (TL-ARFIMA) combination models are investigated. The forecast confidence bands and the forecast updating methodology, provided for ARIMA models in the literature, are modified for the ARFIMA models. Sample autocorrelation functions are utilized to estimate the differencing lengths of the ARFIMA

Light Curve Periodic Variability of Cyg X-1 using Jurkevich Method ...

Indian Academy of Sciences (India)

Abstract. The Jurkevich method is a useful method to explore periodic- ity in the unevenly sampled observational data. In this work, we adopted the method to the light curve of Cyg X-1 from 1996 to 2012, and found that there is an interesting period of 370 days, which appears in both low/hard and high/soft states.

Calibration device for wide range monitor

International Nuclear Information System (INIS)

Kodoku, Masaya; Sato, Toshifumi.

1989-01-01

The calibration device for a wide range monitor according to the present invention can continuously calibrate the entire counting regions of a wide range monitor. The wide range monitor detect the reactor power in the neutron source region by means of a pulse counting method and detects the reactor power in the intermediate region by means of a cambell method. A calibration signal outputting means is disposed for continuously outputting, as such calibration signals, pulse number varying signals in which the number of pulses per unit time varies depending on the reactor power in the neutron source region to be simulated and amplitude square means varying signal in which the mean square value of amplitude varies depending on the reactor power in the intermediate region to be simulated. By using both of the calibration signals, calibration can be conducted for the nuclear reactor power in the neutron source region and the intermediate region even if the calibration is made over two regions, further, calibration for the period present over the two region can be conducted easily as well. (I.S.)

Naphthalene, a polycyclic aromatic hydrocarbon, in the fish samples from the Bangsai river of Bangladesh by gas chromatograph–mass spectrometry

Directory of Open Access Journals (Sweden)

M. Amzad Hossain

2014-12-01

Full Text Available Naphthalene, a polycyclic aromatic hydrocarbon (PAH, was detected and quantified in the selected varieties of fishes collected from the Bangsai river, one of the contaminated rivers located at Savar near the Dhaka Export Processing Zone (DEPZ, Bangladesh, during the period October 2009. Naphthalene, a carcinogenic compound, was analyzed by GC–MS as it was in the mixture of dichloromethane–hexane (1:1 crude extract of the flesh of fish samples collected from the aforesaid river. A suitable and reliable procedure for the extraction of naphthalene from the fish sample has been developed. A multi-layer clean-up (silica gel column was used, followed by glass fiber filter (GFF paper to eliminate the interfering organic compounds as well as the lipids and fat. It was observed that PAHs deposition on the samples takes place in different morphological parts of the biological materials. The PAH, naphthalene, was found in almost all of the fish samples and the concentration of which was in the range 0.030–1.004 μg/g. Recovery studies with fortified samples indicated that the recovery efficiency for naphthalene was about 79.14%. This concentration is within the range of values reported for other comparable regions of the world.

Influence of Sampling Season and Sampling Protocol on Detection of Legionella Pneumophila Contamination in Hot Water / Paraugu Ņemšanas Sezonalitātes Un Paraugu Ņemšanas Metodes Ietekme Uz Legionella Pneumophila Kontaminācijas Noteikšanu Karstajš Ūdenī

Directory of Open Access Journals (Sweden)

Pūle Daina

2016-08-01

Full Text Available Legionella pneumophila is an environmental pathogen of engineered water systems that can cause different forms of legionellosis - from mild fever to potentially lethal pneumonia. Low concentrations of legionellae in natural habitats can increase markedly in engineered hot water systems where water temperatures are below 55 °C. In the current study, we aimed to investigate the influence of sampling season, hot water temperature and sampling protocol on occurrence of L. pneumophila. A total of 120 hot water samples from 20 apartment buildings were collected in two sampling periods - winter 2014 (n = 60 and summer 2015 (n = 60. Significantly higher occurrence of L. pneumophila was observed in summer 2015. Significant differences in temperature for negative and positive samples were not observed, which can be explained by low water temperatures at the point of water consumption. Temperature above 55 °C was observed only once, for all other sampling events it ranged from 14 °C to 53 °C.

Preparation of samples for leaf architecture studies, a method for mounting cleared leaves.

Science.gov (United States)

Vasco, Alejandra; Thadeo, Marcela; Conover, Margaret; Daly, Douglas C

2014-09-01

Several recent waves of interest in leaf architecture have shown an expanding range of approaches and applications across a number of disciplines. Despite this increased interest, examination of existing archives of cleared and mounted leaves shows that current methods for mounting, in particular, yield unsatisfactory results and deterioration of samples over relatively short periods. Although techniques for clearing and staining leaves are numerous, published techniques for mounting leaves are scarce. • Here we present a complete protocol and recommendations for clearing, staining, and imaging leaves, and, most importantly, a method to permanently mount cleared leaves. • The mounting protocol is faster than other methods, inexpensive, and straightforward; moreover, it yields clear and permanent samples that can easily be imaged, scanned, and stored. Specimens mounted with this method preserve well, with leaves that were mounted more than 35 years ago showing no signs of bubbling or discoloration.

Low larval densities in northern populations reinforce range expansion by a Mediterranean damselfly

DEFF Research Database (Denmark)

Therry, Lieven; Swaegers, Janne; Dinh, Khuong Van

2016-01-01

indicated higher food availability at low conspecific densities. Interestingly, the initial density treatment had stronger effect than densities experienced at the time of quantification on survival during the pre-freezing winter period and body condition estimates at the end of the experiment, indicating...... also delayed effects of the initial density treatment. Survival throughout a freezing period indicated extreme winter conditions are not likely a limiting factor in the range expansion of this Mediterranean species. 4. The increased survival and individual growth rates (through causing shifts......1. Contemporary climate change triggers a poleward range shift in many species. A growing number of studies document evolutionary changes in traits accelerating range expansion (such as growth rate and dispersal-related traits). In contrast, the direct impact of decreasing conspecific densities...

Investigation of hidden periodic structures on SEM images of opal-like materials using FFT and IFFT.

Science.gov (United States)

Stephant, Nicolas; Rondeau, Benjamin; Gauthier, Jean-Pierre; Cody, Jason A; Fritsch, Emmanuel

2014-01-01

We have developed a method to use fast Fourier transformation (FFT) and inverse fast Fourier transformation (IFFT) to investigate hidden periodic structures on SEM images. We focused on samples of natural, play-of-color opals that diffract visible light and hence are periodically structured. Conventional sample preparation by hydrofluoric acid etch was not used; untreated, freshly broken surfaces were examined at low magnification relative to the expected period of the structural features, and, the SEM was adjusted to get a very high number of pixels in the images. These SEM images were treated by software to calculate autocorrelation, FFT, and IFFT. We present how we adjusted SEM acquisition parameters for best results. We first applied our procedure on an SEM image on which the structure was obvious. Then, we applied the same procedure on a sample that must contain a periodic structure because it diffracts visible light, but on which no structure was visible on the SEM image. In both cases, we obtained clearly periodic patterns that allowed measurements of structural parameters. We also investigated how the irregularly broken surface interfered with the periodic structure to produce additional periodicity. We tested the limits of our methodology with the help of simulated images. © 2014 Wiley Periodicals, Inc.

Frequency-Modulated Continuous Flow Analysis Electrospray Ionization Mass Spectrometry (FM-CFA-ESI-MS) for Sample Multiplexing.

Science.gov (United States)

Filla, Robert T; Schrell, Adrian M; Coulton, John B; Edwards, James L; Roper, Michael G

2018-02-20

A method for multiplexed sample analysis by mass spectrometry without the need for chemical tagging is presented. In this new method, each sample is pulsed at unique frequencies, mixed, and delivered to the mass spectrometer while maintaining a constant total flow rate. Reconstructed ion currents are then a time-dependent signal consisting of the sum of the ion currents from the various samples. Spectral deconvolution of each reconstructed ion current reveals the identity of each sample, encoded by its unique frequency, and its concentration encoded by the peak height in the frequency domain. This technique is different from other approaches that have been described, which have used modulation techniques to increase the signal-to-noise ratio of a single sample. As proof of concept of this new method, two samples containing up to 9 analytes were multiplexed. The linear dynamic range of the calibration curve was increased with extended acquisition times of the experiment and longer oscillation periods of the samples. Because of the combination of the samples, salt had little effect on the ability of this method to achieve relative quantitation. Continued development of this method is expected to allow for increased numbers of samples that can be multiplexed.

Magnitude of 14C/12C variations based on archaeological samples

International Nuclear Information System (INIS)

Kusumgar, S.; Agrawal, D.P.

1977-01-01

The magnitude of 14 C/ 12 C variations in the period A.D. 5O0 to 200 B.C. and 370 B.C. to 2900 B.C. is discussed. The 14 C dates of well-dated archaeological samples from India and Egypt do not show any significant divergence from the historical ages. On the other hand, the corrections based on dendrochronological samples show marked deviations for the same time period. A plea is, therefore, made to study old tree samples from Anatolia and Irish bogs and archaeological samples from west Asia to arrive at a more realistic calibration curve. (author)

Variability of cannabis potency in the Venice area (Italy): a survey over the period 2010-2012.

Science.gov (United States)

Zamengo, Luca; Frison, Giampietro; Bettin, Chiara; Sciarrone, Rocco

2014-01-01

Cannabis is the most widely used illicit substance globally, with an estimated annual prevalence in 2010 of 2.6-5.0% of the adult population. Concerns have been expressed about increases in the potency of cannabis products. A high tetrahydrocannabinol (THC) content can increase anxiety, depression, and psychotic symptoms, and can increase the risk of dependence and adverse effects on the respiratory and cardiovascular systems in regular users. The aim of this study was to report statistical data about the potency of cannabis products seized in the north-east of Italy, in a geographical area centred in Venice and extending for more than 10,000  km(2) with a population of more than two million, by investigating the variability observed in THC levels of about 4000 samples of cannabis products analyzed over the period 2010-2012. Overall median THC content showed an increasing trend over the study period from about 6.0% to 8.1% (6.2-8.9% for cannabis resin, 5.1-7.6% for herbal cannabis). The variation in the THC content of individual samples was very large, ranging from 0.3% to 31% for cannabis resin and from 0.1 to 19% for herbal cannabis. Median CBN:THC ratios showed a slightly decreasing trend over the study period, from 0.09 (2010) to 0.03 (2012), suggesting an increasing freshness of submitted materials. Median CBD:THC ratios also showed a decreasing trend over the study from about 0.52 (2010) to 0.18 (2012), likely due to the increase in submissions of materials from indoor and domestic cultivation with improved breeding methods. Copyright © 2013 John Wiley & Sons, Ltd.

Color measurement of tea leaves at different drying periods using hyperspectral imaging technique.

Science.gov (United States)

Xie, Chuanqi; Li, Xiaoli; Shao, Yongni; He, Yong

2014-01-01

This study investigated the feasibility of using hyperspectral imaging technique for nondestructive measurement of color components (ΔL*, Δa* and Δb*) and classify tea leaves during different drying periods. Hyperspectral images of tea leaves at five drying periods were acquired in the spectral region of 380-1030 nm. The three color features were measured by the colorimeter. Different preprocessing algorithms were applied to select the best one in accordance with the prediction results of partial least squares regression (PLSR) models. Competitive adaptive reweighted sampling (CARS) and successive projections algorithm (SPA) were used to identify the effective wavelengths, respectively. Different models (least squares-support vector machine [LS-SVM], PLSR, principal components regression [PCR] and multiple linear regression [MLR]) were established to predict the three color components, respectively. SPA-LS-SVM model performed excellently with the correlation coefficient (rp) of 0.929 for ΔL*, 0.849 for Δa*and 0.917 for Δb*, respectively. LS-SVM model was built for the classification of different tea leaves. The correct classification rates (CCRs) ranged from 89.29% to 100% in the calibration set and from 71.43% to 100% in the prediction set, respectively. The total classification results were 96.43% in the calibration set and 85.71% in the prediction set. The result showed that hyperspectral imaging technique could be used as an objective and nondestructive method to determine color features and classify tea leaves at different drying periods.

Color measurement of tea leaves at different drying periods using hyperspectral imaging technique.

Directory of Open Access Journals (Sweden)

Chuanqi Xie

Full Text Available This study investigated the feasibility of using hyperspectral imaging technique for nondestructive measurement of color components (ΔL*, Δa* and Δb* and classify tea leaves during different drying periods. Hyperspectral images of tea leaves at five drying periods were acquired in the spectral region of 380-1030 nm. The three color features were measured by the colorimeter. Different preprocessing algorithms were applied to select the best one in accordance with the prediction results of partial least squares regression (PLSR models. Competitive adaptive reweighted sampling (CARS and successive projections algorithm (SPA were used to identify the effective wavelengths, respectively. Different models (least squares-support vector machine [LS-SVM], PLSR, principal components regression [PCR] and multiple linear regression [MLR] were established to predict the three color components, respectively. SPA-LS-SVM model performed excellently with the correlation coefficient (rp of 0.929 for ΔL*, 0.849 for Δa*and 0.917 for Δb*, respectively. LS-SVM model was built for the classification of different tea leaves. The correct classification rates (CCRs ranged from 89.29% to 100% in the calibration set and from 71.43% to 100% in the prediction set, respectively. The total classification results were 96.43% in the calibration set and 85.71% in the prediction set. The result showed that hyperspectral imaging technique could be used as an objective and nondestructive method to determine color features and classify tea leaves at different drying periods.

Operating manual for Ford's Farm Range air samplers

International Nuclear Information System (INIS)

Glissmeyer, J.A.; Halverson, M.A.

1980-10-01

An air-sampling program was designed for a target enclosure at the Ford's Farm Range, Aberdeen Proving Ground, Maryland, where the Army test-fires tungsten and depleted-uranium armor penetrators. The primary potential particle inhalation hazard is depleted uranium. The sampling program includes workplace and filtered exhaust air sampling. Conventional isokinetic stack sampling was employed for the filtered exhaust air. Because of the need for rapid monitor response to concentration increases and decreases, conventional radioactive particle monitors were not used. Instead, real-time aerosol monitors employing a light-scattering technique were used for monitors requiring a fast response. For other monitoring functions, piezoelectric and beta-attenuation respirable-particle sampling techniques were used. The application of these technologies to the monitoring of airborne radioactive contaminants is addressed. Sampler installation and operation are detailed

Age-specific infectious period shapes dynamics of pneumonia in bighorn sheep.

Science.gov (United States)

Plowright, Raina K; Manlove, Kezia R; Besser, Thomas E; Páez, David J; Andrews, Kimberly R; Matthews, Patrick E; Waits, Lisette P; Hudson, Peter J; Cassirer, E Frances

2017-10-01

Superspreading, the phenomenon where a small proportion of individuals contribute disproportionately to new infections, has profound effects on disease dynamics. Superspreading can arise through variation in contacts, infectiousness or infectious periods. The latter has received little attention, yet it drives the dynamics of many diseases of critical public health, livestock health and conservation concern. Here, we present rare evidence of variation in infectious periods underlying a superspreading phenomenon in a free-ranging wildlife system. We detected persistent infections of Mycoplasma ovipneumoniae, the primary causative agent of pneumonia in bighorn sheep (Ovis canadensis), in a small number of older individuals that were homozygous at an immunologically relevant genetic locus. Interactions among age-structure, genetic composition and infectious periods may drive feedbacks in disease dynamics that determine the magnitude of population response to infection. Accordingly, variation in initial conditions may explain divergent population responses to infection that range from recovery to catastrophic decline and extirpation. © 2017 John Wiley & Sons Ltd/CNRS.

Periodic boundary conditions and the error-controlled fast multipole method

Energy Technology Data Exchange (ETDEWEB)

Kabadshow, Ivo

2012-08-22

The simulation of pairwise interactions in huge particle ensembles is a vital issue in scientific research. Especially the calculation of long-range interactions poses limitations to the system size, since these interactions scale quadratically with the number of particles. Fast summation techniques like the Fast Multipole Method (FMM) can help to reduce the complexity to O(N). This work extends the possible range of applications of the FMM to periodic systems in one, two and three dimensions with one unique approach. Together with a tight error control, this contribution enables the simulation of periodic particle systems for different applications without the need to know and tune the FMM specific parameters. The implemented error control scheme automatically optimizes the parameters to obtain an approximation for the minimal runtime for a given energy error bound.

Range expansion by Passer montanus in North America

Science.gov (United States)

Burnett, J.L.; Roberts, C.P.; Allen, Craig R.; Brown, M.B.; Moulton, M.P.

2017-01-01

Passer montanus became established in a small area of central North America following its introduction in 1870. P. montanus underwent minimal range expansion in the first 100 years following introduction. However, the North American population of P. montanus is now growing in size and expanding in geographic distribution, having expanded approximately 125 km to the north by 1970. We quantify the distance of spread by P. montanus from its introduction site in the greater St. Louis, Missouri-Illinois, USA area, using distributional (presence) data from the National Audubon Society Christmas Bird Count surveys for the period of 1951 to 2014. Linear regressions of the average annual range center of P. montanus confirmed significant shifts to the north at a rate of 3.3 km/year (P Linear regressions of the linear and angular distance of range center indicates significant northern movement (change in angle of mean range center; P < 0.001) since 1951. Our results quantify the extent of a northward range expansion, and suggesting a probable spread of this species northward.

Evidence for an approx.300 day period in Cygnus X-1

International Nuclear Information System (INIS)

Priedhorsky, W.C.; Terrell, J.; Holt, S.S.

1983-01-01

We present the time history of X-ray emission from Cyg X-1 over an 11 year period, with 10 day resolution. The data were obtained by experiments on the Vela 5B (1969--1979) and Ariel 5 (1974--1980) satellites. Cyg X-1 varies by approx.25% with a 294 +- 4 day period. This modulation is apparently unrelated to the known transitions between the source high and low states. Flux minima occur at 1974.05+nP. The observed period is within the possible range for the precession period of an accretion disk, or of the companion star HDE 226868, in the Cyg X-1 system

Long range transport of fine particle windblown soils and coal fired power station emissions into Hanoi between 2001 to 2008

Energy Technology Data Exchange (ETDEWEB)

Cohen, D.D.; Crawford, J.; Stelcer, E.; Vuong, T.B. [Australian Nuclear Science & Technology Organisation, Kirrawee DC, NSW (Australia)

2010-10-15

Fine particulate matter (PM2.5), source fingerprints and their contributions have been measured and reported previously at Hanoi, Vietnam, from 25 April 2001 to 31 December 2008. In this study back trajectories are used to identify long range transport into Hanoi for two of these sources, namely, windblown dust (Soil) from 12 major deserts in China and emissions from 33 coal fired power plants (Coal) in Vietnam and China. There were 28 days of extreme Soil events with concentrations greater than 6 {mu} g m{sup -3} and 25 days of extreme Coal with concentrations greater than 30 {mu} g m{sup -3} from a total of 748 sampling days during the study period. Through the use of back trajectories it was found that long range transport of soil from the Taklamakan and Gobi desert regions (more than 3000 km to the north west) accounted for 76% of the extreme events for Soil. The three local Vietnamese power stations contributed to 15% of the extreme Coal events, while four Chinese power stations between 300 km and 1700 km to the north-east of Hanoi contributed 50% of the total extreme Coal events measured at the Hanoi sampling site.

Development of a flow controller for long-term sampling of gases and vapors using evacuated canisters.

Science.gov (United States)

Rossner, Alan; Farant, Jean Pierre; Simon, Philippe; Wick, David P

2002-11-15

Anthropogenic activities contribute to the release of a wide variety of volatile organic compounds (VOC) into microenvironments. Developing and implementing new air sampling technologies that allow for the characterization of exposures to VOC can be useful for evaluating environmental and health concerns arising from such occurrences. A novel air sampler based on the use of a capillary flow controller connected to evacuated canisters (300 mL, 1 and 6 L) was designed and tested. The capillary tube, used to control the flow of air, is a variation on a sharp-edge orifice flow controller. It essentially controls the velocity of the fluid (air) as a function of the properties of the fluid, tube diameter and length. A model to predict flow rate in this dynamic system was developed. The mathematical model presented here was developed using the Hagen-Poiseuille equation and the ideal gas law to predict flow into the canisters used to sample for long periods of time. The Hagen-Poiseuille equation shows the relationship between flow rate, pressure gradient, capillary resistance, fluid viscosity, capillary length and diameter. The flow rates evaluated were extremely low, ranging from 0.05 to 1 mL min(-1). The model was compared with experimental results and was shown to overestimate the flow rate. Empirical equations were developed to more accurately predict flow for the 300 mL, 1 and 6 L canisters used for sampling periods ranging from several hours to one month. The theoretical and observed flow rates for different capillary geometries were evaluated. Each capillary flow controller geometry that was tested was found to generate very reproducible results, RSD gas chromatograph. The capillary flow controller was found to exceed the performance of the sorbent samplers in this comparison.

Context and meter enhance long-range planning in music performance

Directory of Open Access Journals (Sweden)

Brian eMathias

2015-01-01

Full Text Available Neural responses demonstrate evidence of resonance, or oscillation, during the production of periodic auditory events. Music contains periodic auditory events that give rise to a sense of beat, which in turn generates a sense of meter on the basis of multiple periodicities. Metrical hierarchies may aid memory for music by facilitating similarity-based associations among sequence events at different periodic distances that unfold in longer contexts. A fundamental question is how metrical associations arising from a musical context influence memory during music performance. Longer contexts may facilitate metrical associations at higher hierarchical levels more than shorter contexts, a prediction of the range model, a formal model of planning processes in music performance (Palmer and Pfordresher, 2003; Pfordresher et al., 2007. Serial ordering errors, in which intended sequence events are produced in incorrect sequence positions, were measured as skilled pianists performed musical pieces that contained excerpts embedded in long or short musical contexts. Pitch errors arose from metrically similar positions and further sequential distances more often when the excerpt was embedded in long contexts compared to short contexts. Musicians’ keystroke intensities and error rates also revealed influences of metrical hierarchies, which differed for performances in long and short contexts. The range model accounted for contextual effects and provided better fits to empirical findings when metrical associations between sequence events were included. Longer sequence contexts may facilitate planning during sequence production by increasing conceptual similarity between hierarchically associated events. These findings are consistent with the notion that neural oscillations at multiple periodicities may strengthen metrical associations across sequence events during planning.

Period meter output in response to terminated ramps of reactivity

Energy Technology Data Exchange (ETDEWEB)

Cummins, J D [Dynamics Group, Control and Instrumentation Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

1962-07-15

The time behaviour of the period meter output has been determined for a range of total reactivity injections and reactivity rates. Some results which are directly applicable to graphite gas cooled reactors are given. (author)

A short period undulator for MAX

International Nuclear Information System (INIS)

Ahola, H.; Meinander, T.

1992-01-01

A hybrid undulator for generation of high brilliance synchrotron radiation in the photon energy range of 60--600 eV at the 550 MeV electron storage ring MAX in Lund, Sweden has been designed and built at the Technical Research Centre of Finland in close collaboration with MAX-lab of Lund University. At the rather modest electron energy of MAX this photon energy range can be reached only by an undulator featuring a fairly short period and the smallest possible magnetic gap. Even then, higher harmonics (up to the 13th) of the radiation spectrum must be utilized. An optimization of the magnetic design resulted in a hybrid configuration of NdFeB magnets and soft iron poles with a period of 24 mm and a minimum magnetic gap of 7--10 mm. A variable-gap vacuum chamber allows reduction of the vacuum gap from a maximum of 20 mm, needed for injection, down to 6 mm during stored beam operation. A special design of this chamber permits a magnetic gap between pole tips that is only 1 mm larger than the vacuum gap. Adequate field uniformity was ensured by calibration of magnets to equal strength at their true operating point and verification of the homogeneity of their magnetization. Magnetic measurements included Hall probe scans of the undulator field and flip coil evaluations of the field integral

Turning the tide: comparison of tidal flow by periodic sea level fluctuation and by periodic bed tilting in scaled landscape experiments of estuaries

Science.gov (United States)

Kleinhans, Maarten G.; van der Vegt, Maarten; Leuven, Jasper; Braat, Lisanne; Markies, Henk; Simmelink, Arjan; Roosendaal, Chris; van Eijk, Arjan; Vrijbergen, Paul; van Maarseveen, Marcel

2017-11-01

Analogue models or scale experiments of estuaries and short tidal basins are notoriously difficult to create in the laboratory because of the difficulty to obtain currents strong enough to transport sand. Our recently discovered method to drive tidal currents by periodically tilting the entire flume leads to intense sediment transport in both the ebb and flood phase, causing dynamic channel and shoal patterns. However, it remains unclear whether tilting produces periodic flows with characteristic tidal properties that are sufficiently similar to those in nature for the purpose of landscape experiments. Moreover, it is not well understood why the flows driven by periodic sea level fluctuation, as in nature, are not sufficient for morphodynamic experiments. Here we compare for the first time the tidal currents driven by sea level fluctuations and by tilting. Experiments were run in a 20 × 3 m straight flume, the Metronome, for a range of tilting periods and with one or two boundaries open at constant head with free inflow and outflow. Also, experiments were run with flow driven by periodic sea level fluctuations. We recorded surface flow velocity along the flume with particle imaging velocimetry and measured water levels along the flume. We compared the results to a one-dimensional model with shallow flow equations for a rough bed, which was tested on the experiments and applied to a range of length scales bridging small experiments and large estuaries. We found that the Reynolds method results in negligible flows along the flume except for the first few metres, whereas flume tilting results in nearly uniform reversing flow velocities along the entire flume that are strong enough to move sand. Furthermore, tidal excursion length relative to basin length and the dominance of friction over inertia is similar in tidal experiments and reality. The sediment mobility converges between the Reynolds method and tilting for flumes hundreds of metres long, which is impractical

Turning the tide: comparison of tidal flow by periodic sea level fluctuation and by periodic bed tilting in scaled landscape experiments of estuaries

Directory of Open Access Journals (Sweden)

M. G. Kleinhans

2017-11-01

Full Text Available Analogue models or scale experiments of estuaries and short tidal basins are notoriously difficult to create in the laboratory because of the difficulty to obtain currents strong enough to transport sand. Our recently discovered method to drive tidal currents by periodically tilting the entire flume leads to intense sediment transport in both the ebb and flood phase, causing dynamic channel and shoal patterns. However, it remains unclear whether tilting produces periodic flows with characteristic tidal properties that are sufficiently similar to those in nature for the purpose of landscape experiments. Moreover, it is not well understood why the flows driven by periodic sea level fluctuation, as in nature, are not sufficient for morphodynamic experiments. Here we compare for the first time the tidal currents driven by sea level fluctuations and by tilting. Experiments were run in a 20  ×  3 m straight flume, the Metronome, for a range of tilting periods and with one or two boundaries open at constant head with free inflow and outflow. Also, experiments were run with flow driven by periodic sea level fluctuations. We recorded surface flow velocity along the flume with particle imaging velocimetry and measured water levels along the flume. We compared the results to a one-dimensional model with shallow flow equations for a rough bed, which was tested on the experiments and applied to a range of length scales bridging small experiments and large estuaries. We found that the Reynolds method results in negligible flows along the flume except for the first few metres, whereas flume tilting results in nearly uniform reversing flow velocities along the entire flume that are strong enough to move sand. Furthermore, tidal excursion length relative to basin length and the dominance of friction over inertia is similar in tidal experiments and reality. The sediment mobility converges between the Reynolds method and tilting for flumes hundreds of

Sample collection and documentation

International Nuclear Information System (INIS)

Cullings, Harry M.; Fujita, Shoichiro; Watanabe, Tadaaki; Yamashita, Tomoaki; Tanaka, Kenichi; Endo, Satoru; Shizuma, Kiyoshi; Hoshi, Masaharu; Hasai, Hiromi

2005-01-01

Beginning within a few weeks after the bombings and periodically during the intervening decades, investigators in Hiroshima and Nagasaki have collected samples of materials that were in the cities at the time of the bombings. Although some early efforts were not driven by specific measurement objectives, many others were. Even some of the very earliest samples collected in 1945 were based on carefully conceived research plans and detailed specifications for samples appropriate to particular retrospective measurements, i.e., of particular residual quantities remaining from exposure to the neutrons and gamma rays from the bombs. This chapter focuses mainly on the work of groups at two institutions that have actively collaborated since the 1980s in major collection efforts and have shared samples among themselves and with other investigators: the Radiation Effects Research Foundation (RERF) and its predecessor the Atomic Bomb Casualty Commission (ABCC), and Hiroshima University. In addition, a number of others are listed, who also contributed to the literature by their collection of samples. (J.P.N.)

Sampling plagues; vital aspect in rice comprehensive protection.

Directory of Open Access Journals (Sweden)

Rafael Meneses

2013-12-01

Full Text Available Food production must be carried out using and maximizing the knowledge and the available technologies, however, one of the main limiting factors of agricultural production and crop quality are the pests and the diseases that attack the cultures from which plants start to grow until their harvest, and even in storage. The periodic sampling in the field generate information regarding the presence of pests, their population density, culture conditions, climatic variables and the presence and activity of natural enemies. Sampling methods vary according to the crop and phenological stage, as well as pests to be sampled. Within the basic components of Integrated Pest Management (IPM is sampling or monitoring of pests, whose main objective is: "To determine when and what action should be made". The determination of the population of pests is a need for phytosanitary control program of any crop. Mechanical Compliance of phytosanitary measures at specified periods according to the needs always leads to wasteful spending, in work, instruments and environmental pollution.

Window period donations during primary cytomegalovirus infection and risk of transfusion-transmitted infections.

Science.gov (United States)

Ziemann, Malte; Heuft, Hans-Gert; Frank, Kerstin; Kraas, Sabine; Görg, Siegfried; Hennig, Holger

2013-05-01

Donors with short interdonation intervals (e.g., apheresis donors) have an increased risk of window period donations. The frequency of cytomegalovirus (CMV) window period donations is important information to decide whether selection of seronegative donors might be advantageous for patients at risk for transfusion-transmitted CMV infections (TT-CMV). CMV seroconversion in 93 donors with positive results in routine CMV antibody testing within at most 35 days after the last seronegative sample was evaluated by Western blot and/or a second antibody test. In donors with unconfirmed seroconversion, an additional later sample was tested. Concentration of CMV DNA was determined in pre- and postseroconversion samples. CMV seroconversion was confirmed in 12 donors (13%). Among these, the last seronegative sample was CMV DNA positive in three donors (25%, below 30 IU/mL). The first seropositive sample was CMV DNA positive in 10 donors (83%, maximum 1600 IU/mL). Both prevalence and median concentration of CMV DNA were higher in the first seropositive sample (p = 0.004 and p = 0.02), with maximum concentrations being reached about 2 weeks after seroconversion. No CMV DNA was detected in samples from donors with unconfirmed seroconversion. At least in donors with short interdonation intervals, most suspected CMV seroconversions are due to false-positive results of the screening test. As window period donations are rare and contain less CMV DNA than the first seropositive donation, avoidance of blood products from primarily seropositive donors is especially helpful to avoid TT-CMV if donors with short interdonation intervals are concerned. © 2013 American Association of Blood Banks.

Normal lactate concentration range in the neonatal brain.

Science.gov (United States)

Tomiyasu, Moyoko; Aida, Noriko; Shibasaki, Jun; Tachibana, Yasuhiko; Endo, Mamiko; Nozawa, Kumiko; Shimizu, Eiji; Tsuji, Hiroshi; Obata, Takayuki

2016-11-01

Lactate peaks are occasionally observed during in vivo magnetic resonance spectroscopy (MRS) scans of the neonatal brain, even in healthy patients. The purpose of this study was to investigate the normal range of neonatal brain lactate concentration, as a definitive normal range would be clinically valuable. Using a clinical 3T scanner (echo/repetition times, 30/5000ms), single-voxel MRS data were obtained from the basal ganglia (BG) and centrum semiovale (CS) in 48 healthy neonates (postconceptional age (PCA), 30-43weeks), nine infants (age, 1-12months old), and 20 children (age, 4-15years). Lactate concentrations were calculated using an MRS signal quantification program, LCModel. Correlations between regional lactate concentration and PCA (neonates), or age (all subjects) were investigated. Absolute lactate concentrations of the BG and CS were as follows: neonates, 0.77mM (0-2.02) [median (range)] and 0.77 (0-1.42), respectively; infants, 0.38 (0-0.79) and 0.49 (0.17-1.17); and children, 0.17 (0-0.76) and 0.22 (0-0.80). Overall, subjects' lactate concentrations decreased significantly with age (Spearman: BG, n=61, ρ=-0.38, p=0.003; CS, n=68, ρ=-0.57, p<0.001). However, during the neonatal period no correlations were detected between lactate concentration in either region and PCA. We determined normal ranges of neonatal lactate concentration, which may prove useful for diagnostic purposes. Further studies regarding changes in brain lactate concentration during development would help clarify the reasons for higher concentrations observed during the neonatal period, and contribute to improvements in diagnoses. Copyright © 2016 Elsevier Inc. All rights reserved.

Sampled-data and discrete-time H2 optimal control

NARCIS (Netherlands)

Trentelman, Harry L.; Stoorvogel, Anton A.

1993-01-01

This paper deals with the sampled-data H2 optimal control problem. Given a linear time-invariant continuous-time system, the problem of minimizing the H2 performance over all sampled-data controllers with a fixed sampling period can be reduced to a pure discrete-time H2 optimal control problem. This

Photonic bandgap structures for long-range surface plasmon polaritons

DEFF Research Database (Denmark)

Bozhevolnyi, Sergey I.; Boltasseva, Alexandra; Søndergaard, Thomas

2005-01-01

Propagation of long-range surface plasmon polaritons (LR-SPPs) along periodically thickness-modulated metal stripes embedded in dielectric is studied both theoretically and experimentally for light wavelengths in the telecom range. We demonstrate that symmetric (with respect to the film surface) nm......-size thickness variations result in the pronounced band gap effect, and obtain very good agreement between measured and simulated (transmission and reflection) spectra. This effect is exploited to realize a compact wavelength add-drop filter with the bandwidth of -20 nm centered at 1550 nm. The possibilities...

Netherlands Army Long Range Anti Armour Study - Status Report

OpenAIRE

Schagen, P.A.B. van

1989-01-01

At the end of the nineties the munition for the TOW weapon system in use at The Netherlands army, has to be replaced. The Life of Type of The Tow carrier ends in 2005. The long range anti armour study is to gain insight into the possibilities and limitations for the Netherlands army to deploy future (time period 1995-2000) weapon systems in the long range anti armour battle. The first study results are expected at the end of 1989. The study is sponsored by the Netherlands army and is carried ...

Periodic optical variability of radio-detected ultracool dwarfs

International Nuclear Information System (INIS)

Harding, L. K.; Golden, A.; Singh, Navtej; Sheehan, B.; Butler, R. F.; Hallinan, G.; Boyle, R. P.; Zavala, R. T.

2013-01-01

A fraction of very low mass stars and brown dwarfs are known to be radio active, in some cases producing periodic pulses. Extensive studies of two such objects have also revealed optical periodic variability, and the nature of this variability remains unclear. Here, we report on multi-epoch optical photometric monitoring of six radio-detected dwarfs, spanning the ∼M8-L3.5 spectral range, conducted to investigate the ubiquity of periodic optical variability in radio-detected ultracool dwarfs. This survey is the most sensitive ground-based study carried out to date in search of periodic optical variability from late-type dwarfs, where we obtained 250 hr of monitoring, delivering photometric precision as low as ∼0.15%. Five of the six targets exhibit clear periodicity, in all cases likely associated with the rotation period of the dwarf, with a marginal detection found for the sixth. Our data points to a likely association between radio and optical periodic variability in late-M/early-L dwarfs, although the underlying physical cause of this correlation remains unclear. In one case, we have multiple epochs of monitoring of the archetype of pulsing radio dwarfs, the M9 TVLM 513–46546, spanning a period of 5 yr, which is sufficiently stable in phase to allow us to establish a period of 1.95958 ± 0.00005 hr. This phase stability may be associated with a large-scale stable magnetic field, further strengthening the correlation between radio activity and periodic optical variability. Finally, we find a tentative spin-orbit alignment of one component of the very low mass binary, LP 349–25.

Periodic optical variability of radio-detected ultracool dwarfs

Energy Technology Data Exchange (ETDEWEB)

Harding, L. K.; Golden, A.; Singh, Navtej; Sheehan, B.; Butler, R. F. [Centre for Astronomy, National University of Ireland, Galway, University Road, Galway (Ireland); Hallinan, G. [Cahill Center for Astrophysics, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Boyle, R. P. [Vatican Observatory Research Group, Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Zavala, R. T., E-mail: lkh@astro.caltech.edu [United States Naval Observatory, Flagstaff Station, Flagstaff, AZ 86001 (United States)

2013-12-20

A fraction of very low mass stars and brown dwarfs are known to be radio active, in some cases producing periodic pulses. Extensive studies of two such objects have also revealed optical periodic variability, and the nature of this variability remains unclear. Here, we report on multi-epoch optical photometric monitoring of six radio-detected dwarfs, spanning the ∼M8-L3.5 spectral range, conducted to investigate the ubiquity of periodic optical variability in radio-detected ultracool dwarfs. This survey is the most sensitive ground-based study carried out to date in search of periodic optical variability from late-type dwarfs, where we obtained 250 hr of monitoring, delivering photometric precision as low as ∼0.15%. Five of the six targets exhibit clear periodicity, in all cases likely associated with the rotation period of the dwarf, with a marginal detection found for the sixth. Our data points to a likely association between radio and optical periodic variability in late-M/early-L dwarfs, although the underlying physical cause of this correlation remains unclear. In one case, we have multiple epochs of monitoring of the archetype of pulsing radio dwarfs, the M9 TVLM 513–46546, spanning a period of 5 yr, which is sufficiently stable in phase to allow us to establish a period of 1.95958 ± 0.00005 hr. This phase stability may be associated with a large-scale stable magnetic field, further strengthening the correlation between radio activity and periodic optical variability. Finally, we find a tentative spin-orbit alignment of one component of the very low mass binary, LP 349–25.

Concentration and characteristics of depleted uranium in water, air and biological samples collected in Serbia and Montenegro

International Nuclear Information System (INIS)

Jia Guogang; Belli, Maria; Sansone, Umberto; Rosamilia, Silvia; Gaudino, Stefania

2005-01-01

During the Balkan conflicts, in 1995 and 1999, depleted uranium (DU) rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Serbia and Montenegro, radiological surveys of DU in water, air and biological samples were carried out over the period 27 October-5 November 2001. The uranium isotopic concentrations in biological samples collected in Serbia and Montenegro, mainly lichens and barks, were found to be in the range of 0.67-704 Bq kg -1 for 238 U, 0.48-93.9 Bq kg -1 for 234 U and 0.02-12.2 Bq kg -1 for 235 U, showing uranium levels to be higher than in the samples collected at the control sites. Moreover, 236 U was detectable in some of the samples. The isotopic ratios of 234 U/ 238 U showed DU to be detectable in many biological samples at all examined sites, especially in Montenegro, indicating widespread ground-surface DU contamination, albeit at very low level. The uranium isotopic concentrations in air obtained from the air filter samples collected in Serbia and Montenegro were found to be in the range of 1.99-42.1 μBq m -3 for 238 U, 0.96-38.0 μBq m -3 for 234 U, and 0.05-1.83 μBq m -3 for 235 U, being in the typical range of natural uranium values. Thus said, most of the air samples are DU positive, this fact agreeing well with the widespread DU contamination detected in the biological samples. The uranium concentrations in water samples collected in Serbia and Montenegro were found to be in the range of 0.40-21.9 mBq l -1 for 238 U, 0.27-28.1 mBq l -1 for 234 U, and 0.01-0.88 mBq l -1 for 235 U, these values being much lower than those in mineral water found in central Italy and below the WHO guideline for drinking water. From a radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated sites in terms of

Concentration and characteristics of depleted uranium in water, air and biological samples collected in Serbia and Montenegro.

Science.gov (United States)

Jia, Guogang; Belli, Maria; Sansone, Umberto; Rosamilia, Silvia; Gaudino, Stefania

2005-09-01

During the Balkan conflicts, in 1995 and 1999, depleted uranium (DU) rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Serbia and Montenegro, radiological surveys of DU in water, air and biological samples were carried out over the period 27 October-5 November 2001. The uranium isotopic concentrations in biological samples collected in Serbia and Montenegro, mainly lichens and barks, were found to be in the range of 0.67-704 Bqkg(-1) for (238)U, 0.48-93.9 Bqkg(-1) for (234)U and 0.02-12.2 Bqkg(-1) for (235)U, showing uranium levels to be higher than in the samples collected at the control sites. Moreover, (236)U was detectable in some of the samples. The isotopic ratios of (234)U/(238)U showed DU to be detectable in many biological samples at all examined sites, especially in Montenegro, indicating widespread ground-surface DU contamination, albeit at very low level. The uranium isotopic concentrations in air obtained from the air filter samples collected in Serbia and Montenegro were found to be in the range of 1.99-42.1 microBqm(-3) for (238)U, 0.96-38.0 microBqm(-3) for (234)U, and 0.05-1.83 microBqm(-3) for (235)U, being in the typical range of natural uranium values. Thus said, most of the air samples are DU positive, this fact agreeing well with the widespread DU contamination detected in the biological samples. The uranium concentrations in water samples collected in Serbia and Montenegro were found to be in the range of 0.40-21.9 mBql(-1) for (238)U, 0.27-28.1 mBql(-1) for (234)U, and 0.01-0.88 mBql(-1) for (235)U, these values being much lower than those in mineral water found in central Italy and below the WHO guideline for drinking water. From a radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated

Subfossil markers of climate change during the Roman Warm Period of the late Holocene

Science.gov (United States)

Jach, Renata; Knutelski, Stanisław; Uchman, Alfred; Hercman, Helena; Dohnalik, Marek

2018-02-01

Abundant bog oak trunks occur in alluvial deposits of the Raba River in the village of Targowisko (southern Poland). Several of them contain galleries of the great capricorn beetle ( Cerambyx cerdo L.). A well-preserved subfossil larva and pupa, as well as adults of this species, are concealed in some of the galleries. These galleries co-occur with boring galleries of other insects such as ship-timber beetles (Lymexylidae) and metallic wood borers (Buprestidae). A dry larva of a stag beetle (Lucanidae) and a mite (Acari) have been found in the C. cerdo galleries. Selected samples of the trunks and a sample of the C. cerdo larva were dated, using radiocarbon and dendrochronological methods, to the period from 45 bc to ad 554; one sample was dated to the period from 799 to 700 bc. Accumulation of the channel alluvia containing the bog oak trunks is synchronous with the Roman Warm Period (late antiquity/Early Mediaeval times). The most recent part of this period correlates with massive accumulations of fallen oak trunks noted from various river valleys in the Carpathian region and dated to ad 450-570. The results indicate that C. cerdo was more abundant within the study area during the Roman Warm Period than it is today.

Reactivity and neutron emission measurements of highly burnt PWR fuel rod samples

International Nuclear Information System (INIS)

Murphy, M.F.; Jatuff, F.; Grimm, P.; Seiler, R.; Brogli, R.; Meier, G.; Berger, H.-D.; Chawla, R.

2006-01-01

Fuel rods with burnup values beyond 50 GWd/t are characterised by relatively large amounts of fission products and a high abundance of major and minor actinides. Of particular interest is the change in the reactivity of the fuel as a function of burnup and the capability of modern codes to predict this change. In addition, the neutron emission from burnt fuel has important implications for the design of transport and storage facilities. Measurements have been made of the reactivity effects and the neutron emission rates of highly burnt uranium oxide and mixed oxide fuel rod samples coming from a pressurised water reactor (PWR). The reactivity measurements have been made in a PWR lattice in the PROTEUS zero-energy reactor moderated in turn with: water, a water and heavy water mixture and water containing boron. A combined transport flask and sample changer was used to insert the 400 mm long burnt fuel rod segments into the reactor. Both control rod compensation and reactor period methods were used to determine the reactivities of the samples. For the range of burnup values investigated, an interesting exponential relationship has been found between the neutron emission rate and the measured reactivity

Period-dependent source rupture behavior of the 2011 Tohoku earthquake estimated by multi period-band Bayesian waveform inversion

Science.gov (United States)

Kubo, H.; Asano, K.; Iwata, T.; Aoi, S.

2014-12-01

Previous studies for the period-dependent source characteristics of the 2011 Tohoku earthquake (e.g., Koper et al., 2011; Lay et al., 2012) were based on the short and long period source models using different method. Kubo et al. (2013) obtained source models of the 2011 Tohoku earthquake using multi period-bands waveform data by a common inversion method and discussed its period-dependent source characteristics. In this study, to achieve more in detail spatiotemporal source rupture behavior of this event, we introduce a new fault surface model having finer sub-fault size and estimate the source models in multi period-bands using a Bayesian inversion method combined with a multi-time-window method. Three components of velocity waveforms at 25 stations of K-NET, KiK-net, and F-net of NIED are used in this analysis. The target period band is 10-100 s. We divide this period band into three period bands (10-25 s, 25-50 s, and 50-100 s) and estimate a kinematic source model in each period band using a Bayesian inversion method with MCMC sampling (e.g., Fukuda & Johnson, 2008; Minson et al., 2013, 2014). The parameterization of spatiotemporal slip distribution follows the multi-time-window method (Hartzell & Heaton, 1983). The Green's functions are calculated by the 3D FDM (GMS; Aoi & Fujiwara, 1999) using a 3D velocity structure model (JIVSM; Koketsu et al., 2012). The assumed fault surface model is based on the Pacific plate boundary of JIVSM and is divided into 384 subfaults of about 16 * 16 km^2. The estimated source models in multi period-bands show the following source image: (1) First deep rupture off Miyagi at 0-60 s toward down-dip mostly radiating relatively short period (10-25 s) seismic waves. (2) Shallow rupture off Miyagi at 45-90 s toward up-dip with long duration radiating long period (50-100 s) seismic wave. (3) Second deep rupture off Miyagi at 60-105 s toward down-dip radiating longer period seismic waves then that of the first deep rupture. (4) Deep

Radiocarbon analysis of BC and OC in PM10 aerosols at Cape Hedo, Okinawa, Japan, during long-range transport events from East Asian countries

International Nuclear Information System (INIS)

Handa, Daishi; Nakajima, Hitomi; Arakaki, Takemitsu; Kumata, Hidetoshi; Shibata, Yasuyuki; Uchida, Masao

2010-01-01

We determined the 14 C/ 12 C ratio and concentrations of black carbon (BC) and organic carbon (OC) in airborne particulate matter (APM) with diameter 10 ) collected in Okinawa, Japan, between March and June 2008. During Asian dust events in March and April, APM and OC concentrations in PM 10 aerosols were approximately threefold and twofold higher than those during the non-Asian-dust period in June. 'Refractory' BC concentrations (i.e., because of refraction, 10 aerosols collected during the Asian dust events (mean = 41.5% and 62.3%, respectively) than for those collected in the non-Asian-dust period (mean = 67.2% and 93.8%, respectively), indicating a strong influence of fossil-fuel-derived carbon during Asian dust events. One sample showed high OC concentration but relatively low BC concentration, suggesting formation during the long-range transport of biogenic organic compounds. The results suggest that not only fossil-fuel-derived air pollutants but also organic compounds derived from biomass in Asia should be considered to better characterize long-range transported aerosols.

Premature death of adult adoptees: analyses of a case-cohort sample.

Science.gov (United States)

Petersen, Liselotte; Andersen, Per Kragh; Sørensen, Thorkild I A

2005-05-01

Genetic and environmental influence on risk of premature death in adulthood was investigated by estimating the associations in total and cause-specific mortality of adult Danish adoptees and their biological and adoptive parents. Among all 14,425 non-familial adoptions formally granted in Denmark during the period 1924 through 1947, we selected the study population according to a case-cohort sampling design. As the case-control design, the case-cohort design has the advantage of economic data collection and little loss in statistical efficiency, but the case-cohort sample has the additional advantages that rate ratio estimates may be obtained, and re-use of the cohort sample in future studies of other outcomes is possible. Analyses were performed using Kalbfleisch and Lawless's estimator for hazard ratio, and robust estimation for variances. In the main analyses the sample was restricted to birth years of the adoptees 1924 and after, and age of transfer to the adoptive parents before 7 years, and age at death was restricted to 16 to 70 years. The results showed a higher mortality among adoptees, whose biological parents died in the age range of 16 to 70 years; this was significant for deaths from natural causes, vascular causes and all causes. No influence was seen from early death of adoptive parents, regardless of cause of death. (c) 2005 Wiley-Liss, Inc.

Field sampling, preparation procedure and plutonium analyses of large freshwater samples

International Nuclear Information System (INIS)

Straelberg, E.; Bjerk, T.O.; Oestmo, K.; Brittain, J.E.

2002-01-01

This work is part of an investigation of the mobility of plutonium in freshwater systems containing humic substances. A well-defined bog-stream system located in the catchment area of a subalpine lake, Oevre Heimdalsvatn, Norway, is being studied. During the summer of 1999, six water samples were collected from the tributary stream Lektorbekken and the lake itself. However, the analyses showed that the plutonium concentration was below the detection limit in all the samples. Therefore renewed sampling at the same sites was carried out in August 2000. The results so far are in agreement with previous analyses from the Heimdalen area. However, 100 times higher concentrations are found in the lowlands in the eastern part of Norway. The reason for this is not understood, but may be caused by differences in the concentrations of humic substances and/or the fact that the mountain areas are covered with snow for a longer period of time every year. (LN)

THEORETICAL CEPHEID PERIOD-LUMINOSITY AND PERIOD-COLOR RELATIONS IN SPITZER IRAC BANDS

International Nuclear Information System (INIS)

Ngeow, Chow-Choong; Marconi, Marcella; Musella, Ilaria; Cignoni, Michele; Kanbur, Shashsi M.

2012-01-01

In this paper, the synthetic period-luminosity (P-L) relations in Spitzer's IRAC bands, based on a series of theoretical pulsation models with varying metal and helium abundance, were investigated. Selected sets of these synthetic P-L relations were compared to the empirical IRAC band P-L relations recently determined from Galactic and Magellanic Clouds Cepheids. For the Galactic case, synthetic P-L relations from model sets with (Y = 0.26, Z = 0.01), (Y = 0.26, Z = 0.02), and (Y = 0.28, Z = 0.02) agree with the empirical Galactic P-L relations derived from the Hubble Space Telescope parallaxes. For Magellanic Cloud Cepheids, the synthetic P-L relations from model sets with (Y = 0.25, Z = 0.008) agree with both of the empirical Large Magellanic Cloud (LMC) and Small Magellanic Cloud P-L relations. Analysis of the synthetic P-L relations from all model sets suggested that the IRAC band P-L relations may not be independent of metallicity, as the P-L slopes and intercepts could be affected by the metallicity and/or helium abundance. We also derive the synthetic period-color (P-C) relations in the IRAC bands. Non-vanishing synthetic P-C relations were found for certain combinations of IRAC band filters and metallicity. However, the synthetic P-C relations disagreed with the [3.6]-[8.0] P-C relation recently found for the Galactic Cepheids. The synthetic [3.6]-[4.5] P-C slope from the (Y = 0.25, Z = 0.008) model set, on the other hand, is in excellent agreement to the empirical LMC P-C counterpart, if a period range 1.0 < log (P) < 1.8 is adopted.

Low-sampling-rate ultra-wideband channel estimation using equivalent-time sampling

KAUST Repository

Ballal, Tarig

2014-09-01

In this paper, a low-sampling-rate scheme for ultra-wideband channel estimation is proposed. The scheme exploits multiple observations generated by transmitting multiple pulses. In the proposed scheme, P pulses are transmitted to produce channel impulse response estimates at a desired sampling rate, while the ADC samples at a rate that is P times slower. To avoid loss of fidelity, the number of sampling periods (based on the desired rate) in the inter-pulse interval is restricted to be co-prime with P. This condition is affected when clock drift is present and the transmitted pulse locations change. To handle this case, and to achieve an overall good channel estimation performance, without using prior information, we derive an improved estimator based on the bounded data uncertainty (BDU) model. It is shown that this estimator is related to the Bayesian linear minimum mean squared error (LMMSE) estimator. Channel estimation performance of the proposed sub-sampling scheme combined with the new estimator is assessed in simulation. The results show that high reduction in sampling rate can be achieved. The proposed estimator outperforms the least squares estimator in almost all cases, while in the high SNR regime it also outperforms the LMMSE estimator. In addition to channel estimation, a synchronization method is also proposed that utilizes the same pulse sequence used for channel estimation. © 2014 IEEE.

Periodic feedback stabilization for linear periodic evolution equations

CERN Document Server

Wang, Gengsheng

2016-01-01

This book introduces a number of recent advances regarding periodic feedback stabilization for linear and time periodic evolution equations. First, it presents selected connections between linear quadratic optimal control theory and feedback stabilization theory for linear periodic evolution equations. Secondly, it identifies several criteria for the periodic feedback stabilization from the perspective of geometry, algebra and analyses respectively. Next, it describes several ways to design periodic feedback laws. Lastly, the book introduces readers to key methods for designing the control machines. Given its coverage and scope, it offers a helpful guide for graduate students and researchers in the areas of control theory and applied mathematics.

Influence of Sampling Effort on the Estimated Richness of Road-Killed Vertebrate Wildlife

Science.gov (United States)

Bager, Alex; da Rosa, Clarissa A.

2011-05-01

Road-killed mammals, birds, and reptiles were collected weekly from highways in southern Brazil in 2002 and 2005. The objective was to assess variation in estimates of road-kill impacts on species richness produced by different sampling efforts, and to provide information to aid in the experimental design of future sampling. Richness observed in weekly samples was compared with sampling for different periods. In each period, the list of road-killed species was evaluated based on estimates the community structure derived from weekly samplings, and by the presence of the ten species most subject to road mortality, and also of threatened species. Weekly samples were sufficient only for reptiles and mammals, considered separately. Richness estimated from the biweekly samples was equal to that found in the weekly samples, and gave satisfactory results for sampling the most abundant and threatened species. The ten most affected species showed constant road-mortality rates, independent of sampling interval, and also maintained their dominance structure. Birds required greater sampling effort. When the composition of road-killed species varies seasonally, it is necessary to take biweekly samples for a minimum of one year. Weekly or more-frequent sampling for periods longer than two years is necessary to provide a reliable estimate of total species richness.

Validation of single-sample doubly labeled water method

International Nuclear Information System (INIS)

Webster, M.D.; Weathers, W.W.

1989-01-01

We have experimentally validated a single-sample variant of the doubly labeled water method for measuring metabolic rate and water turnover in a very small passerine bird, the verdin (Auriparus flaviceps). We measured CO 2 production using the Haldane gravimetric technique and compared these values with estimates derived from isotopic data. Doubly labeled water results based on the one-sample calculations differed from Haldane values by less than 0.5% on average (range -8.3 to 11.2%, n = 9). Water flux computed by the single-sample method differed by -1.5% on average from results for the same birds based on the standard, two-sample technique (range -13.7 to 2.0%, n = 9)

Misleading prioritizations from modelling range shifts under climate change

Science.gov (United States)

Sofaer, Helen R.; Jarnevich, Catherine S.; Flather, Curtis H.

2018-01-01

AimConservation planning requires the prioritization of a subset of taxa and geographical locations to focus monitoring and management efforts. Integration of the threats and opportunities posed by climate change often relies on predictions from species distribution models, particularly for assessments of vulnerability or invasion risk for multiple taxa. We evaluated whether species distribution models could reliably rank changes in species range size under climate and land use change.LocationConterminous U.S.A.Time period1977–2014.Major taxa studiedPasserine birds.MethodsWe estimated ensembles of species distribution models based on historical North American Breeding Bird Survey occurrences for 190 songbirds, and generated predictions to recent years given c. 35 years of observed land use and climate change. We evaluated model predictions using standard metrics of discrimination performance and a more detailed assessment of the ability of models to rank species vulnerability to climate change based on predicted range loss, range gain, and overall change in range size.ResultsSpecies distribution models yielded unreliable and misleading assessments of relative vulnerability to climate and land use change. Models could not accurately predict range expansion or contraction, and therefore failed to anticipate patterns of range change among species. These failures occurred despite excellent overall discrimination ability and transferability to the validation time period, which reflected strong performance at the majority of locations that were either always or never occupied by each species.Main conclusionsModels failed for the questions and at the locations of greatest interest to conservation and management. This highlights potential pitfalls of multi-taxa impact assessments under global change; in our case, models provided misleading rankings of the most impacted species, and spatial information about range changes was not credible. As modelling methods and

STRUCTURE AND NUTRITIVE VALUE OF DEFERRED PASTURE OF BRACHIARIA DECUMBENS CV. BASILISK DURING THE GRAZING PERIOD

Directory of Open Access Journals (Sweden)

Manoel Eduardo Rozalino Santos

2011-07-01

Full Text Available The experiment aimed to understand the effect of grazing period on morphology and nutritive value of deferred Brachiaria decumbens cv. Basilisk pasture and on hand-plucking sample with cattle. Subdivided plots were used according to a randomized block design with two replicates. Four grazing periods (1, 31, 57 and 88 days and two forage samples (available in pasture (AP and obtained by hand-plucking (HP were studied. The live leaf laminae (LLL, potentially digestible neutral detergent fiber (PDNDF, potentially digestible dry matter (PDDM and crude protein (CP levels were higher and dead leaf laminae (DLL, and dead stem (DS, neutral detergent fiber (NDF and indigestible NDF percentages were lower in sample of HP in relation to forage AP. The grazing period decreased linearly the LLL, PDNDF, PDDM percentages, as well as increased linearly DS and indigestible NDF levels in forages. The potential selectivity indexes (PSI of LLL and indigestible NDF increased linearly with grazing period. The PSI of live stem was smaller and the PSI of CP was higher in interim periods of grazing. The reduction in deferring period results in B. decumbens with better morphological composition and nutritional value, which favors the animal selectivity.

Interval sampling methods and measurement error: a computer simulation.

Science.gov (United States)

Wirth, Oliver; Slaven, James; Taylor, Matthew A

2014-01-01

A simulation study was conducted to provide a more thorough account of measurement error associated with interval sampling methods. A computer program simulated the application of momentary time sampling, partial-interval recording, and whole-interval recording methods on target events randomly distributed across an observation period. The simulation yielded measures of error for multiple combinations of observation period, interval duration, event duration, and cumulative event duration. The simulations were conducted up to 100 times to yield measures of error variability. Although the present simulation confirmed some previously reported characteristics of interval sampling methods, it also revealed many new findings that pertain to each method's inherent strengths and weaknesses. The analysis and resulting error tables can help guide the selection of the most appropriate sampling method for observation-based behavioral assessments. © Society for the Experimental Analysis of Behavior.

Females' sampling strategy to comparatively evaluate prospective mates in the peacock blenny Salaria pavo

Science.gov (United States)

Locatello, Lisa; Rasotto, Maria B.

2017-08-01

Emerging evidence suggests the occurrence of comparative decision-making processes in mate choice, questioning the traditional idea of female choice based on rules of absolute preference. In such a scenario, females are expected to use a typical best-of- n sampling strategy, being able to recall previous sampled males based on memory of their quality and location. Accordingly, the quality of preferred mate is expected to be unrelated to both the number and the sequence of female visits. We found support for these predictions in the peacock blenny, Salaria pavo, a fish where females have the opportunity to evaluate the attractiveness of many males in a short time period and in a restricted spatial range. Indeed, even considering the variability in preference among females, most of them returned to previous sampled males for further evaluations; thus, the preferred male did not represent the last one in the sequence of visited males. Moreover, there was no relationship between the attractiveness of the preferred male and the number of further visits assigned to the other males. Our results suggest the occurrence of a best-of- n mate sampling strategy in the peacock blenny.

Total nuclear photoabsorption cross section in the range 0.2-1.0 GeV for nuclei throughout the periodic table

International Nuclear Information System (INIS)

Terranova, M.L.; Tavares, O.A.P.

1994-01-01

An analysis of the total photoabsorption cross section for nuclei ranging from 4 He up to 238 U has been performed in the energy range 0.2-1.0 GeV. Mean total photoabsorption cross sections have been obtained by summing up the contributions from partial photoreactions, and found to follow an A 1 -dependence in the 0.2-1.0 GeV range. A review of the available total photoabsorption cross section data is also presented. Comparisons have been made with cross section values calculated by considering both the quasi-deuteron and π-meson photoproduction mechanism of primary nuclear photointeraction. (orig.)

Application of a UV-Vis submersible probe for capturing changes in DOC concentrations across a mire complex during the snowmelt and summer periods

Science.gov (United States)

Avagyan, Armine; Runkle, Benjamin; Kutzbach, Lars

2013-04-01

An accurate quantification of dissolved organic carbon (DOC) is crucial for understanding changes in water resources under the influence of climate, land use and urbanization. However, the conventionally used methods do not allow high frequency in situ analyses in remote or hostile environments (e.g., industrial wastewater or during environmental high-flow events, such as snowmelt or floods). In particular, missing measurements during the snowmelt period in landscapes of the boreal region can lead to significant miscalculations in regional carbon budgets. Therefore, the aim of the study was to test the performance of a portable, submersible UV-Vis spectrophotometer (spectro::lyser, s::can Messtechnik GmbH, Austria) during the snowmelt period in a boreal mire-forest catchment, and to provide a conceptual understanding of the spatial and temporal dynamics of DOC concentrations during and after snowmelt. During 2011, water samples were collected from the near-pristine Ust-Pojeg mire complex in northwestern Russia (61° 56'N, 50° 13'E). Sampling started during the spring snowmelt period and continued until late fall. The mire presented a mosaic of different landscape units. The mire consisted of minerogeous (fen), ombrogenous (bog), and transitional forest-mire (lagg) zones. Water samples were taken from the surface across the mire (22 points at 50-m intervals). DOC concentrations were analyzed directly at the study site using a portable, submersible UV-Vis spectrophotometer, which uses high-resolution absorbance measurements over the wavelength range 200-742.5 nm at 2.5-nm intervals as a proxy for DOC content. Because the DOC composition of fluids varies by site, a local calibration replaced the default settings of the spectro::lyser (Global Calibration) to enhance the accuracy of the measurements. To evaluate the local calibration and correct for drift, the same samples (n = 157) were additionally analyzed using the wet persulfate oxidation method (O

Solvent Hold Tank Sample Results for MCU-16-596-597-598: April 2016 Monthly Sample

Energy Technology Data Exchange (ETDEWEB)

Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL). Advanced Characterization and Processing; Jones, D. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL). Research Support

2016-07-12

Savannah River National Laboratory (SRNL) received one set of Solvent Hold Tank (SHT) samples (MCU-16-596-597-598), pulled on 04/30/2016 for analysis. The samples were combined and analyzed for composition. Analysis of the composite sample MCU-16-596-597-598 indicated the Isopar™L concentration is above its nominal level (102%). The modifier (CS-7SB) is 14% below its nominal concentration, while the TiDG and MaxCalix concentrations are at and above their nominal concentrations, respectively. This analysis confirms the solvent may require the addition of modifier. Based on the current monthly sample, the levels of TiDG, Isopar™L, MaxCalix, and modifier are sufficient for continuing operation but are expected to decrease with time. Periodic characterization and trimming additions to the solvent are recommended.

Three-dimensional range data compression using computer graphics rendering pipeline.

Science.gov (United States)

Zhang, Song

2012-06-20

This paper presents the idea of naturally encoding three-dimensional (3D) range data into regular two-dimensional (2D) images utilizing computer graphics rendering pipeline. The computer graphics pipeline provides a means to sample 3D geometry data into regular 2D images, and also to retrieve the depth information for each sampled pixel. The depth information for each pixel is further encoded into red, green, and blue color channels of regular 2D images. The 2D images can further be compressed with existing 2D image compression techniques. By this novel means, 3D geometry data obtained by 3D range scanners can be instantaneously compressed into 2D images, providing a novel way of storing 3D range data into its 2D counterparts. We will present experimental results to verify the performance of this proposed technique.

Direct analysis of radionuclides-96 samples simultaneously

International Nuclear Information System (INIS)

Kessler, M.J.

1991-01-01

Recently, there has been a tremendous interest in two areas of concern in nuclear counting and radioactivity waste disposal. The first is the reduction of radioactive waste, in particular the reduction in the amount of or the development of environmentally safe scintillation cocktails. The second is the development of a simple method of quantitating large numbers of samples (thousands/day) in a short period of time (minutes). These two areas of concern have been addressed with the development of the Matrix 96 direct beta counter. This new instrumental technique is capable of quantitating 96 samples simultaneously in the microplate format (8 x 12, 96 sample) on a solid support WITHOUT the use of any cocktails, vials, and is non-destructive to the sample. The use of this technique for the following biomedical applications, DNA dot blots, cell proliferation (3H thymidine), receptor binding, chromium cytotoxicity assays, and protein assays will be discussed in detail. The data from both the conventional beta and gamma counter will be correlated and compared to the new Matrix 96 direct beta counter. This new technique provides a convenient method of addressing the concerns of reducing radioactive waste and provides a method of quantitating a large number of samples, accurately in a short period of time (96 at a time)

Isotopes and ages in the northern Peninsular Ranges batholith, southern California

Science.gov (United States)

Kistler, Ronald W.; Wooden, Joseph L.; Morton, Douglas M.

2003-01-01

Strontium, oxygen and lead isotopic and rubidium-strontium geochronologic studies have been completed on Cretaceous and Jurassic (?) granitic rock samples from the northern Peninsular Ranges batholith in southern California. Many of these samples were collected systematically and studied chemically by A. K. Baird and colleagues (Baird and others, 1979). The distribution of these granitic rocks is shown in the Santa Ana, Perris, and San Jacinto Blocks, bounded by the Malibu Coast-Cucamonga, Banning, and San Andreas fault zones, and the Pacific Ocean on the map of the Peninsular Ranges batholith and surrounding area, southern California. The granitic rock names are by Baird and Miesch (1984) who used a modal mineral classification that Bateman and others (1963) used for granitic rocks in the Sierra Nevada batholith. In this classification, granitic rocks have at least 10% quartz. Boundaries between rock types are in terms of the ratio of alkali-feldspar to total feldspar: quartz diorite, 0-10%; granodiorite, 10-35%; quartz monzonite 35-65%; granite >65%. Gabbros have 0-10% quartz. Data for samples investigated are giv in three tables: samples, longitude, latitude, specific gravity and rock type (Table 1); rubidium and strontium data for granitic rocks of the northern Peninsular Ranges batholith, southern California (Table 2); U, Th, Pb concentrations, Pb and Sr initial isotopic compositions, and δ18O permil values for granitic rocks of the northern Peninsular Ranges batholith (table 3).

On-capillary sample cleanup method for the electrophoretic determination of carbohydrates in juice samples.

Science.gov (United States)

Morales-Cid, Gabriel; Simonet, Bartolomé M; Cárdenas, Soledad; Valcárcel, Miguel

2007-05-01

On many occasions, sample treatment is a critical step in electrophoretic analysis. As an alternative to batch procedures, in this work, a new strategy is presented with a view to develop an on-capillary sample cleanup method. This strategy is based on the partial filling of the capillary with carboxylated single-walled carbon nanotube (c-SWNT). The nanoparticles retain interferences from the matrix allowing the determination and quantification of carbohydrates (viz glucose, maltose and fructose). The precision of the method for the analysis of real samples ranged from 5.3 to 6.4%. The proposed method was compared with a method based on a batch filtration of the juice sample through diatomaceous earth and further electrophoretic determination. This method was also validated in this work. The RSD for this other method ranged from 5.1 to 6%. The results obtained by both methods were statistically comparable demonstrating the accuracy of the proposed methods and their effectiveness. Electrophoretic separation of carbohydrates was achieved using 200 mM borate solution as a buffer at pH 9.5 and applying 15 kV. During separation, the capillary temperature was kept constant at 40 degrees C. For the on-capillary cleanup method, a solution containing 50 mg/L of c-SWNTs prepared in 300 mM borate solution at pH 9.5 was introduced for 60 s into the capillary just before sample introduction. For the electrophoretic analysis of samples cleaned in batch with diatomaceous earth, it is also recommended to introduce into the capillary, just before the sample, a 300 mM borate solution as it enhances the sensitivity and electrophoretic resolution.

Inter comparison of 90Sr and 137Cs contents in biologic samples and natural U in soil samples

International Nuclear Information System (INIS)

Liu Jianfen; Zeng Guangjian; Lu Xuequan

2001-01-01

The results of the 90 Sr and 137 Cs contents in biologic samples and the natural U in soil samples obtained in a joint effort by fourteen environmental radiation laboratories in the Chinese environmental protection system were analyzed and compared. Two kinds of biologic samples and one kind of soil samples were used for inter comparison. Of which, one kind of biologic samples (biologic powder samples) and the soil samples came from the IAEA samples were environmental and the reference values were known. The another kind of biologic samples were environmental tea-leaf that were taken from a tea garden near Hangzhou. The mean values obtained by all the joined laboratories was used as the reference. The inter comparison results were expressed in terms of the deviation from the reference value. It was found that the deviation of the 90 Sr and 137 Cs contents of biologic powder samples ranged from -15.4% to 26.5% and -15.0% to 0.4%, respectively. The deviation of the natural U content ranged from -25.5% to 7.3% for the soil samples. For the tea-leaf, the 90 Sr deviation was -22.7% to 19.1%, and the 137 Cs data had a relative large scatter with a ratio of the maximum and the minimum values being about 7. It was pointed out that the analysis results offered by different laboratories might have involved system errors

Determining Sample Size with a Given Range of Mean Effects in One-Way Heteroscedastic Analysis of Variance

Science.gov (United States)

Shieh, Gwowen; Jan, Show-Li

2013-01-01

The authors examined 2 approaches for determining the required sample size of Welch's test for detecting equality of means when the greatest difference between any 2 group means is given. It is shown that the actual power obtained with the sample size of the suggested approach is consistently at least as great as the nominal power. However, the…

Polycyclic aromatic hydrocarbons in air samples of meat smokehouses

DEFF Research Database (Denmark)

Hansen, Åse Marie; Olsen, I L; Poulsen, O M

1992-01-01

In a screening programme nine Danish meat smokehouses were randomly selected for measurements on concentration of airborne polycyclic aromatic hydrocarbons (PAH). A total of 23 stationary air samples were collected during the entire working period of the kiln either above the kiln doors or approx......In a screening programme nine Danish meat smokehouses were randomly selected for measurements on concentration of airborne polycyclic aromatic hydrocarbons (PAH). A total of 23 stationary air samples were collected during the entire working period of the kiln either above the kiln doors...

Sampling Methodologies for Epidemiologic Surveillance of Men Who Have Sex with Men and Transgender Women in Latin America: An Empiric Comparison of Convenience Sampling, Time Space Sampling, and Respondent Driven Sampling

Science.gov (United States)

Clark, J. L.; Konda, K. A.; Silva-Santisteban, A.; Peinado, J.; Lama, J. R.; Kusunoki, L.; Perez-Brumer, A.; Pun, M.; Cabello, R.; Sebastian, J. L.; Suarez-Ognio, L.; Sanchez, J.

2014-01-01

Alternatives to convenience sampling (CS) are needed for HIV/STI surveillance of most-at-risk populations in Latin America. We compared CS, time space sampling (TSS), and respondent driven sampling (RDS) for recruitment of men who have sex with men (MSM) and transgender women (TW) in Lima, Peru. During concurrent 60-day periods from June–August, 2011, we recruited MSM/TW for epidemiologic surveillance using CS, TSS, and RDS. A total of 748 participants were recruited through CS, 233 through TSS, and 127 through RDS. The TSS sample included the largest proportion of TW (30.7 %) and the lowest percentage of subjects who had previously participated in HIV/STI research (14.9 %). The prevalence of newly diagnosed HIV infection, according to participants’ self-reported previous HIV diagnosis, was highest among TSS recruits (17.9 %) compared with RDS (12.6 %) and CS (10.2 %). TSS identified diverse populations of MSM/TW with higher prevalences of HIV/STIs not accessed by other methods. PMID:24362754

Sampling methodologies for epidemiologic surveillance of men who have sex with men and transgender women in Latin America: an empiric comparison of convenience sampling, time space sampling, and respondent driven sampling.

Science.gov (United States)

Clark, J L; Konda, K A; Silva-Santisteban, A; Peinado, J; Lama, J R; Kusunoki, L; Perez-Brumer, A; Pun, M; Cabello, R; Sebastian, J L; Suarez-Ognio, L; Sanchez, J

2014-12-01

Alternatives to convenience sampling (CS) are needed for HIV/STI surveillance of most-at-risk populations in Latin America. We compared CS, time space sampling (TSS), and respondent driven sampling (RDS) for recruitment of men who have sex with men (MSM) and transgender women (TW) in Lima, Peru. During concurrent 60-day periods from June-August, 2011, we recruited MSM/TW for epidemiologic surveillance using CS, TSS, and RDS. A total of 748 participants were recruited through CS, 233 through TSS, and 127 through RDS. The TSS sample included the largest proportion of TW (30.7 %) and the lowest percentage of subjects who had previously participated in HIV/STI research (14.9 %). The prevalence of newly diagnosed HIV infection, according to participants' self-reported previous HIV diagnosis, was highest among TSS recruits (17.9 %) compared with RDS (12.6 %) and CS (10.2 %). TSS identified diverse populations of MSM/TW with higher prevalences of HIV/STIs not accessed by other methods.

Investigation on cause of malfunction of wide range monitor (WRM) in high temperature engineering test reactor (HTTR). Sample tests and destructive tests

International Nuclear Information System (INIS)

Shinohara, Masanori; Saito, Kenji; Haga, Hiroyuki; Sasaki, Shinji; Katsuyama, Kozo; Motegi, Toshihiro; Takada, Kiyoshi; Higashimura, Keisuke; Fujii, Junichi; Ukai, Takayuki; Moriguchi, Yusuke

2012-11-01

An event, in which one of WRMs were disabled to detect the neutron flux in the reactor core, occurred during the period of reactor shut down of HTTR in March, 2010. The actual life time of WRM was unexpectedly shorter than the past developed life time. Investigation of the cause of the outage of WRM toward the recovery of the life time up to the past developed life is one of the issues to develop the technology basis of High Temperature Gas cooled Reactor (HTGR). Then, two experimental investigations were carried out to reveal the cause of the malfunction by specifying the damaged part causing the event in the WRM. One is an experiment using a mock-up sample test which strength degradation at assembly process and heat cycle to specify the damaged part in the WRM. The other is a destructive test in Fuels Monitoring Facility (FMF) to specify the damaged part in the WRM. This report summarized the results of the destructive test and the experimental investigation using the mock-up to reveal the cause of malfunction of WRM. (author)

Survey research with a random digit dial national mobile phone sample in Ghana: Methods and sample quality

Science.gov (United States)

Sefa, Eunice; Adimazoya, Edward Akolgo; Yartey, Emmanuel; Lenzi, Rachel; Tarpo, Cindy; Heward-Mills, Nii Lante; Lew, Katherine; Ampeh, Yvonne

2018-01-01

Introduction Generating a nationally representative sample in low and middle income countries typically requires resource-intensive household level sampling with door-to-door data collection. High mobile phone penetration rates in developing countries provide new opportunities for alternative sampling and data collection methods, but there is limited information about response rates and sample biases in coverage and nonresponse using these methods. We utilized data from an interactive voice response, random-digit dial, national mobile phone survey in Ghana to calculate standardized response rates and assess representativeness of the obtained sample. Materials and methods The survey methodology was piloted in two rounds of data collection. The final survey included 18 demographic, media exposure, and health behavior questions. Call outcomes and response rates were calculated according to the American Association of Public Opinion Research guidelines. Sample characteristics, productivity, and costs per interview were calculated. Representativeness was assessed by comparing data to the Ghana Demographic and Health Survey and the National Population and Housing Census. Results The survey was fielded during a 27-day period in February-March 2017. There were 9,469 completed interviews and 3,547 partial interviews. Response, cooperation, refusal, and contact rates were 31%, 81%, 7%, and 39% respectively. Twenty-three calls were dialed to produce an eligible contact: nonresponse was substantial due to the automated calling system and dialing of many unassigned or non-working numbers. Younger, urban, better educated, and male respondents were overrepresented in the sample. Conclusions The innovative mobile phone data collection methodology yielded a large sample in a relatively short period. Response rates were comparable to other surveys, although substantial coverage bias resulted from fewer women, rural, and older residents completing the mobile phone survey in

Survey research with a random digit dial national mobile phone sample in Ghana: Methods and sample quality.

Science.gov (United States)

L'Engle, Kelly; Sefa, Eunice; Adimazoya, Edward Akolgo; Yartey, Emmanuel; Lenzi, Rachel; Tarpo, Cindy; Heward-Mills, Nii Lante; Lew, Katherine; Ampeh, Yvonne

2018-01-01

Generating a nationally representative sample in low and middle income countries typically requires resource-intensive household level sampling with door-to-door data collection. High mobile phone penetration rates in developing countries provide new opportunities for alternative sampling and data collection methods, but there is limited information about response rates and sample biases in coverage and nonresponse using these methods. We utilized data from an interactive voice response, random-digit dial, national mobile phone survey in Ghana to calculate standardized response rates and assess representativeness of the obtained sample. The survey methodology was piloted in two rounds of data collection. The final survey included 18 demographic, media exposure, and health behavior questions. Call outcomes and response rates were calculated according to the American Association of Public Opinion Research guidelines. Sample characteristics, productivity, and costs per interview were calculated. Representativeness was assessed by comparing data to the Ghana Demographic and Health Survey and the National Population and Housing Census. The survey was fielded during a 27-day period in February-March 2017. There were 9,469 completed interviews and 3,547 partial interviews. Response, cooperation, refusal, and contact rates were 31%, 81%, 7%, and 39% respectively. Twenty-three calls were dialed to produce an eligible contact: nonresponse was substantial due to the automated calling system and dialing of many unassigned or non-working numbers. Younger, urban, better educated, and male respondents were overrepresented in the sample. The innovative mobile phone data collection methodology yielded a large sample in a relatively short period. Response rates were comparable to other surveys, although substantial coverage bias resulted from fewer women, rural, and older residents completing the mobile phone survey in comparison to household surveys. Random digit dialing of mobile

Survey research with a random digit dial national mobile phone sample in Ghana: Methods and sample quality.

Directory of Open Access Journals (Sweden)

Kelly L'Engle

Full Text Available Generating a nationally representative sample in low and middle income countries typically requires resource-intensive household level sampling with door-to-door data collection. High mobile phone penetration rates in developing countries provide new opportunities for alternative sampling and data collection methods, but there is limited information about response rates and sample biases in coverage and nonresponse using these methods. We utilized data from an interactive voice response, random-digit dial, national mobile phone survey in Ghana to calculate standardized response rates and assess representativeness of the obtained sample.The survey methodology was piloted in two rounds of data collection. The final survey included 18 demographic, media exposure, and health behavior questions. Call outcomes and response rates were calculated according to the American Association of Public Opinion Research guidelines. Sample characteristics, productivity, and costs per interview were calculated. Representativeness was assessed by comparing data to the Ghana Demographic and Health Survey and the National Population and Housing Census.The survey was fielded during a 27-day period in February-March 2017. There were 9,469 completed interviews and 3,547 partial interviews. Response, cooperation, refusal, and contact rates were 31%, 81%, 7%, and 39% respectively. Twenty-three calls were dialed to produce an eligible contact: nonresponse was substantial due to the automated calling system and dialing of many unassigned or non-working numbers. Younger, urban, better educated, and male respondents were overrepresented in the sample.The innovative mobile phone data collection methodology yielded a large sample in a relatively short period. Response rates were comparable to other surveys, although substantial coverage bias resulted from fewer women, rural, and older residents completing the mobile phone survey in comparison to household surveys. Random digit

Sampling soils for 137Cs using various field-sampling volumes

International Nuclear Information System (INIS)

Nyhan, J.W.; Schofield, T.G.; White, G.C.; Trujillo, G.

1981-10-01

The sediments from a liquid effluent receiving area at the Los Alamos National Laboratory and soils from intensive study area in the fallout pathway of Trinity were sampled for 137 Cs using 25-, 500-, 2500-, and 12 500-cm 3 field sampling volumes. A highly replicated sampling program was used to determine mean concentrations and inventories of 137 Cs at each site, as well as estimates of spatial, aliquoting, and counting variance components of the radionuclide data. The sampling methods were also analyzed as a function of soil size fractions collected in each field sampling volume and of the total cost of the program for a given variation in the radionuclide survey results. Coefficients of variation (CV) of 137 Cs inventory estimates ranged from 0.063 to 0.14 for Mortandad Canyon sediments, where CV values for Trinity soils were observed from 0.38 to 0.57. Spatial variance components of 137 Cs concentration data were usually found to be larger than either the aliquoting or counting variance estimates and were inversely related to field sampling volume at the Trinity intensive site. Subsequent optimization studies of the sampling schemes demonstrated that each aliquot should be counted once, and that only 2 to 4 aliquots out of an many as 30 collected need be assayed for 137 Cs. The optimization studies showed that as sample costs increased to 45 man-hours of labor per sample, the variance of the mean 137 Cs concentration decreased dramatically, but decreased very little with additional labor

Reduction of Friction of Metals Using Laser-Induced Periodic Surface Nanostructures

Directory of Open Access Journals (Sweden)

Zhuo Wang

2015-10-01

Full Text Available We report on the effect of femtosecond-laser-induced periodic surface structures (LIPSS on the tribological properties of stainless steel. Uniform periodic nanostructures were produced on AISI 304L (American Iron and Steel Institute steel grade steel surfaces using an 800-nm femtosecond laser. The spatial periods of LIPSS measured by field emission scanning electron microscopy ranged from 530 to 570 nm. The tribological properties of smooth and textured surfaces with periodic nanostructures were investigated using reciprocating ball-on-flat tests against AISI 440C balls under both dry and starved oil lubricated conditions. The friction coefficient of LIPSS covered surfaces has shown a lower value than that of the smooth surface. The induced periodic nanostructures demonstrated marked potential for reducing the friction coefficient compared with the smooth surface.

Preparation of Samples for Leaf Architecture Studies, A Method for Mounting Cleared Leaves

Directory of Open Access Journals (Sweden)

Alejandra Vasco

2014-09-01

Full Text Available Premise of the study: Several recent waves of interest in leaf architecture have shown an expanding range of approaches and applications across a number of disciplines. Despite this increased interest, examination of existing archives of cleared and mounted leaves shows that current methods for mounting, in particular, yield unsatisfactory results and deterioration of samples over relatively short periods. Although techniques for clearing and staining leaves are numerous, published techniques for mounting leaves are scarce. Methods and Results: Here we present a complete protocol and recommendations for clearing, staining, and imaging leaves, and, most importantly, a method to permanently mount cleared leaves. Conclusions: The mounting protocol is faster than other methods, inexpensive, and straightforward; moreover, it yields clear and permanent samples that can easily be imaged, scanned, and stored. Specimens mounted with this method preserve well, with leaves that were mounted more than 35 years ago showing no signs of bubbling or discoloration.

Target recognition of ladar range images using even-order Zernike moments.

Science.gov (United States)

Liu, Zheng-Jun; Li, Qi; Xia, Zhi-Wei; Wang, Qi

2012-11-01

Ladar range images have attracted considerable attention in automatic target recognition fields. In this paper, Zernike moments (ZMs) are applied to classify the target of the range image from an arbitrary azimuth angle. However, ZMs suffer from high computational costs. To improve the performance of target recognition based on small samples, even-order ZMs with serial-parallel backpropagation neural networks (BPNNs) are applied to recognize the target of the range image. It is found that the rotation invariance and classified performance of the even-order ZMs are both better than for odd-order moments and for moments compressed by principal component analysis. The experimental results demonstrate that combining the even-order ZMs with serial-parallel BPNNs can significantly improve the recognition rate for small samples.

Endoparasitic infections in free-ranging Asiatic elephants of Mudumalai and Anamalai Wildlife Sanctuary.

Science.gov (United States)

Vimalraj, P G; Jayathangaraj, M G

2015-09-01

Free-ranging Asiatic elephants dung samples from various forest divisions of Mudumalai Wildlife Sanctuary (MWLS) and Anamalai Wildlife Sanctuary (AWLS) were examined for identification of endoparasitic infection. The dung samples revealed 100 % endoparasitic infection, with a high prevalence of Strongyles (64 %) in MWLS and Anoplocephala sp. (46 %) in AWLS. Similarly, from the same samples egg per gram of feces was done to ascertain the individual parasitic load. The present research paper communicates the high parasitic prevalence of free-ranging Asian elephants in dry seasons of (February-June 2010) MWLS and AWLS.

All-periodically poled, high-power, continuous-wave, single-frequency tunable UV source.

Science.gov (United States)

Aadhi, A; Chaitanya N, Apurv; Jabir, M V; Singh, R P; Samanta, G K

2015-01-01

We report on experimental demonstration of an all-periodically poled, continuous-wave (CW), high-power, single-frequency, ultra-violet (UV) source. Based on internal second-harmonic-generation (SHG) of a CW singly resonant optical parametric oscillator (OPO) pumped in the green, the UV source provides tunable radiation across 398.94-417.08 nm. The compact source comprising of a 25-mm-long MgO-doped periodically poled stoichiometric lithium tantalate (MgO:sPPLT) crystal of period Λ(SLT)=8.5  μm for OPO and a 5-mm-long, multi-grating (Λ(KTP)=3.3, 3.4, 3.6 and 3.8 μm), periodically poled potassium titanium phosphate (PPKTP) for intra-cavity SHG, provides as much as 336 mW of UV power at 398.94 nm, corresponding to a green-to-UV conversion efficiency of ∼6.7%. In addition, the singly resonant OPO (SRO) provides 840 mW of idler at 1541.61 nm and substantial signal power of 108 mW at 812.33 nm transmitted through the high reflective cavity mirrors. UV source provides single-frequency radiation with instantaneous line-width of ∼18.3  MHz and power >100  mW in Gaussian beam profile (ellipticity >92%) across the entire tuning range. Access to lower UV wavelengths requires smaller grating periods to compensate high phase-mismatch resulting from high material dispersion in the UV wavelength range. Additionally, we have measured the normalized temperature and spectral acceptance bandwidth of PPKTP crystal in the UV wavelength range to be ∼2.25°C·cm and ∼0.15  nm·cm, respectively.

Long-period structures in gold-copper alloys; Structures a longues periodes dans les alliages or-cuivre

Energy Technology Data Exchange (ETDEWEB)

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

1965-07-01

We first proceed to reevaluation of the gold-copper equilibrium diagram for alloys between Au{sub 20}Cu{sub 80} and Au{sub 65}Cu{sub 35}. The identification of the various phases was performed by X-rays diffraction on quenched polycrystalline samples. We next study the structure of the phase AuCuII. X-ray data collected from bulk single crystals show that this long-period structure must be described with the help of two correlated periodic functions: an 'order function' and a 'displacement function'. The 'order function' conciliates the non-integer value of the period with its rigorous definition. The 'displacement function' accounts for the dis-symmetries of the observed intensities for the antiphase homologous reflections as the appearance of satellites around the fundamental reflections. These two functions are remarkably well defined at long distance in carefully annealed samples and, in some conditions, can be obtained independently. We observe that the improvement of the degree of order increases the 'modulation of position'. In the case of non stoichiometric alloys, the excess of gold atoms (gold rich alloys) is distributed at random whereas the excess of copper (copper rich alloys) is distributed in a preferential manner close to the antiphase boundaries. (author) [French] Nous procedons, tout d'abord, a une reevaluation du diagramme d'equilibre des alliages or-cuivre compris entre Au{sub 20}Cu{sub 80} et Au{sub 65}Cu{sub 35}. L'identification des differentes phases s'est faite par diffraction de rayons X sur des echantillons polycristallins trempes. Nous etudions ensuite, aux rayons X, la structure de la phase AuCuII. Les donnees rassemblees sur monocristaux massifs indiquent que cette structure a longue periode doit etre decrite a l'aide de deux fonctions periodiques correlees: une fonction d'ordre et une fonction de deplacement des atomes. La fonction d'ordre concilie le caractere non entier de la periode avec sa rigoureuse definition. La fonction de

Total nuclear photoabsorption cross section in the range 0.2 - 1.0 GeV for nuclei throughout the periodic table

International Nuclear Information System (INIS)

Terranova, M.L.; Tavares, O.A.P.

1993-01-01

An analysis of the total photoabsorption cross section for nuclei ranging from 4 He up to 238 U has been performed in the energy range 0.2-1.0 GeV. Mean total photoabsorption cross sections have been obtained by summing up the contributions from partial photo reactions, and found to follow an A l -dependence in the 0.2-1.0 GeV range. A review of the available total photoabsorption cross section data is also presented. Comparisons have been made with cross section values calculated by considering both the quasi-deuteron and π-meson photoproduction mechanism of primary nuclear photo interaction. (author)

Long-range volcanic ash transport and fallout during the 2008 eruption of Chaiten volcano, Chile

Science.gov (United States)

Durant, A. J.; Prata, A. J.; Villarosa, G.; Rose, W. I.; Delmelle, P.; Viramonte, J.

2012-04-01

The May 2008 eruption of Chaitén volcano, Chile, provided a rare opportunity to measure the long-range transport of volcanic emissions and characteristics of a widely-dispersed terrestrial ash deposit. Airborne ash mass, quantified using thermal infrared satellite remote sensing, ranged between 0.2-0.4 Tg during the period 3-7 May 2008. A high level of spatiotemporal correspondence was observed between cloud trajectories and changes in surface reflectivity, which was inferred to indicate ash deposition. The evolution of the deposit was mapped for the first time using satellite-based observations of surface reflectivity. The distal (>80 km) ash deposit was poorly sorted and fine grained, and mean particle size varied very little beyond a distance >300 km. There were 3 consistent particle size subpopulations in fallout at distances >300 km which suggests that aggregation influenced particle settling. Discrete temporal sampling and characterisation of fallout demonstrated contributions from specific eruptive phases. Some evidence for winnowing was identified through comparison of samples collected at the time of deposition to bulk samples collected months after deposition. X-Ray Photoelectron Spectroscopy (XPS) analyses revealed surface enrichments in Ca, Na and Fe and the presence of coatings of mixed Ca-, Na- and Fe-rich salts on ash particles prior to deposition. XPS analyses revealed strong surface Fe enrichments (in contrast to the results from bulk leachate analyses), which indicates that surface analysis techniques should be applied to investigate potential influences on ocean productivity in response to volcanic ash fallout over oceans. Low S:Cl ratios in leachates indicate that the eruption had a low S content, and high Cl:F ratios imply gas-ash interaction within a Cl-rich environment. We estimate that ash fallout had potential to scavenge ~42 % of total S released into the atmosphere prior to deposition.

A Wide Lock-Range Referenceless CDR with Automatic Frequency Acquisition

OpenAIRE

Seon-Kyoo Lee; Young-Sang Kim; Hong-June Park; Jae-Yoon Sim

2011-01-01

A wide lock-range referenceless CDR circuit is proposed with an automatic tracking of data rate. For efficient frequency acquisition, a DLL-based loop is used with a simple phase/frequency detector to extract 1-bit period of input data stream. The CDR, implemented in a 65 nm CMOS, shows a lock range of 650 Mb/s-to-8 Gb/s and BER of less than 10-12 at 8 Gb/s with low power consumption.

A Wide Lock-Range Referenceless CDR with Automatic Frequency Acquisition

Directory of Open Access Journals (Sweden)

Seon-Kyoo Lee

2011-01-01

Full Text Available A wide lock-range referenceless CDR circuit is proposed with an automatic tracking of data rate. For efficient frequency acquisition, a DLL-based loop is used with a simple phase/frequency detector to extract 1-bit period of input data stream. The CDR, implemented in a 65 nm CMOS, shows a lock range of 650 Mb/s-to-8 Gb/s and BER of less than 10-12 at 8 Gb/s with low power consumption.

Solvent hold tank sample results for MCU-16-1363-1365. November 2016 monthly sample

Energy Technology Data Exchange (ETDEWEB)

Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jones, D. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-03-22

Savannah River National Laboratory (SRNL) received one set of three Solvent Hold Tank (SHT) samples (MCU-16-1363-1364-1365), pulled on 11/15/2016 for analysis. The samples were combined and analyzed for composition. Analysis of the composite sample MCU-16-1363-1364-1365 indicated the Isopar™L concentration is at its nominal level (100%). The extractant (MaxCalix) and the modifier (CS- 7SB) are 8% and 2 % below their nominal concentrations. The suppressor (TiDG) is 7% below its nominal concentration. This analysis confirms the trim and Isopar™ additions to the solvent in November. This analysis also indicates the solvent did not require further additions. Based on the current monthly sample, the levels of TiDG, Isopar™L, MaxCalix, and modifier are sufficient for continuing operation but are expected to decrease with time. Periodic characterization and trimming additions to the solvent are recommended.

Range distributions in multiply implanted targets

International Nuclear Information System (INIS)

Kostic, S.; Jimenez-Rodriguez, J.J.; Karpuzov, D.S.; Armour, D.G.; Carter, G.; Salford Univ.

1984-01-01

Range distributions in inhomogeneous binary targets have been investigated both theoretically and experimentally. Silicon single crystal targets [(111) orientation] were implanted with 40 keV Pb + ions to fluences in the range from 5x10 14 to 7.5x10 16 cm -2 prior to bombardment with 80 keV Kr + ions to a fluence of 5x10 15 cm -2 . The samples were analysed using high resolution Rutherford backscattering before and after the krypton implantation in order to determine the dependence of the krypton distribution on the amount of lead previously implanted. The theoretical analysis was undertaken using the formalism developed in [1] and the computer simulation was based on the MARLOWE code. The agreement between the experimental, theoretical and computational krypton profiles is very good and the results indicate that accurate prediction of ranges profiles in inhomogeneous binary targets is possible using available theoretical and computational treatments. (orig.)

Sample size for morphological traits of pigeonpea

Directory of Open Access Journals (Sweden)

Giovani Facco

2015-12-01

Full Text Available The objectives of this study were to determine the sample size (i.e., number of plants required to accurately estimate the average of morphological traits of pigeonpea (Cajanus cajan L. and to check for variability in sample size between evaluation periods and seasons. Two uniformity trials (i.e., experiments without treatment were conducted for two growing seasons. In the first season (2011/2012, the seeds were sown by broadcast seeding, and in the second season (2012/2013, the seeds were sown in rows spaced 0.50 m apart. The ground area in each experiment was 1,848 m2, and 360 plants were marked in the central area, in a 2 m × 2 m grid. Three morphological traits (e.g., number of nodes, plant height and stem diameter were evaluated 13 times during the first season and 22 times in the second season. Measurements for all three morphological traits were normally distributed and confirmed through the Kolmogorov-Smirnov test. Randomness was confirmed using the Run Test, and the descriptive statistics were calculated. For each trait, the sample size (n was calculated for the semiamplitudes of the confidence interval (i.e., estimation error equal to 2, 4, 6, ..., 20% of the estimated mean with a confidence coefficient (1-? of 95%. Subsequently, n was fixed at 360 plants, and the estimation error of the estimated percentage of the average for each trait was calculated. Variability of the sample size for the pigeonpea culture was observed between the morphological traits evaluated, among the evaluation periods and between seasons. Therefore, to assess with an accuracy of 6% of the estimated average, at least 136 plants must be evaluated throughout the pigeonpea crop cycle to determine the sample size for the traits (e.g., number of nodes, plant height and stem diameter in the different evaluation periods and between seasons. 

High sensitivity high-resolution full range relaxometry using a fast mechanical sample shuttling device and a cryo-probe

Energy Technology Data Exchange (ETDEWEB)

Chou, Ching-Yu [Université Paris-Saclay, NIMBE, CEA, CNRS (France); Chu, Minglee [Academia Sinica, Institute of Physics (China); Chang, Chi-Fon [Academia Sinica, Genomics Research Center (China); Yu, Tsunai; Huang, Tai-huang, E-mail: bmthh@gate.sinica.edu.tw [Academia Sinica, Institute of Biomedical Science (China); Sakellariou, Dimitris, E-mail: dimitrios.sakellariou@cea.fr [Université Paris-Saclay, NIMBE, CEA, CNRS (France)

2016-11-15

Field-dependent NMR studies of bio-molecular systems using a sample shuttling hardware operating on a high-field NMR apparatus have provided valuable structural and dynamic information. We have recently published a design of a compact sample transportation device, called “field-cycler”, which was installed in a commercial spectrometer and which provided highly precise positioning and stability during high speed shuttling. In this communication, we demonstrate the first use of a sample shuttling device on a commercial high field standard bore NMR spectrometer, equipped with a commercial triple resonance cryogenically cooled NMR probe. The performance and robustness of the hardware operating in 1D and 2D field cycling experiments, as well as the impact of the sample shuttling time on the signal intensity are discussed.

Radiation hazards evaluation for selected sand samples from Camburi beach, Vitoria, Espirito Santo, Brazil

International Nuclear Information System (INIS)

Barros, Livia F.; Pecequilo, Brigitte R.S.

2013-01-01

In this work, a single location at Camburi beach, known to be a naturally high background region, was studied. Radiation hazards indexes and annual effective dose were evaluated from the 226 Ra, 232 Th and 40 K sands activities concentrations. Sand samples were monthly collected during 2011, dried, sealed in standard 100 mL HPDE polyethylene flasks and measured by high resolution gamma spectrometry after a 4 weeks in-growth period. The 226 Ra concentration was determined from the weighted average concentrations of 214 Pb and 214 Bi. The 232 Th concentration was determined from the weighted average concentrations of 228 Ac, 212 Pb and 212 Bi and the 4 0K from its single gamma transition. The results, considering samples gamma-rays self-attenuation, show activities concentrations in the range from 6 Bq kg -1 to 39 Bq kg -1 for 226 Ra, 13 Bq kg -1 to 161 Bq kg -1 for 232 Th, and 7 Bq kg -1 to 65 Bq kg -1 for 40 K. The radium equivalent activity for the studied samples ranged from 26 Bq kg -1 to 274 Bq kg - '1. The external and internal hazard indexes varied, respectively, from 0.07 to 0.74 and from 0.09 to 0.85. The annual effective dose values laid from 0.07 mSv.y -1 to 0.72 mSv.y - '1. All values obtained in this work are below the radiological protection recommended limits. (author)

Validity of the reduced-sample insulin modified frequently-sampled intravenous glucose tolerance test using the nonlinear regression approach.

Science.gov (United States)

Sumner, Anne E; Luercio, Marcella F; Frempong, Barbara A; Ricks, Madia; Sen, Sabyasachi; Kushner, Harvey; Tulloch-Reid, Marshall K

2009-02-01

The disposition index, the product of the insulin sensitivity index (S(I)) and the acute insulin response to glucose, is linked in African Americans to chromosome 11q. This link was determined with S(I) calculated with the nonlinear regression approach to the minimal model and data from the reduced-sample insulin-modified frequently-sampled intravenous glucose tolerance test (Reduced-Sample-IM-FSIGT). However, the application of the nonlinear regression approach to calculate S(I) using data from the Reduced-Sample-IM-FSIGT has been challenged as being not only inaccurate but also having a high failure rate in insulin-resistant subjects. Our goal was to determine the accuracy and failure rate of the Reduced-Sample-IM-FSIGT using the nonlinear regression approach to the minimal model. With S(I) from the Full-Sample-IM-FSIGT considered the standard and using the nonlinear regression approach to the minimal model, we compared the agreement between S(I) from the Full- and Reduced-Sample-IM-FSIGT protocols. One hundred African Americans (body mass index, 31.3 +/- 7.6 kg/m(2) [mean +/- SD]; range, 19.0-56.9 kg/m(2)) had FSIGTs. Glucose (0.3 g/kg) was given at baseline. Insulin was infused from 20 to 25 minutes (total insulin dose, 0.02 U/kg). For the Full-Sample-IM-FSIGT, S(I) was calculated based on the glucose and insulin samples taken at -1, 1, 2, 3, 4, 5, 6, 7, 8,10, 12, 14, 16, 19, 22, 23, 24, 25, 27, 30, 40, 50, 60, 70, 80, 90, 100, 120, 150, and 180 minutes. For the Reduced-Sample-FSIGT, S(I) was calculated based on the time points that appear in bold. Agreement was determined by Spearman correlation, concordance, and the Bland-Altman method. In addition, for both protocols, the population was divided into tertiles of S(I). Insulin resistance was defined by the lowest tertile of S(I) from the Full-Sample-IM-FSIGT. The distribution of subjects across tertiles was compared by rank order and kappa statistic. We found that the rate of failure of resolution of S(I) by

Isotope dilution analysis of environmental samples

International Nuclear Information System (INIS)

Tolgyessy, J.; Lesny, J.; Korenova, Z.; Klas, J.; Klehr, E.H.

1986-01-01

Isotope dilution analysis has been used for the determination of several trace elements - especially metals - in a variety of environmental samples, including aerosols, water, soils, biological materials and geological materials. Variations of the basic concept include classical IDA, substoichiometric IDA, and more recently, sub-superequivalence IDA. Each variation has its advantages and limitations. A periodic chart has been used to identify those elements which have been measured in environmental samples using one or more of these methods. (author)

Electromagnetic radiation of electrons in periodic structures

International Nuclear Information System (INIS)

Potylitsyn, Alexander Petrovich

2011-01-01

Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation and the Smith-Purcell effect. Characteristics of such radiation sources and perspectives of their usage are discussed. The recent experimental results as well as their interpretation are presented. (orig.)

Periodic differential equations an introduction to Mathieu, Lamé, and allied functions

CERN Document Server

Arscott, Felix M; Stark, M; Ulam, S

1964-01-01

Periodic Differential Equations: An Introduction to Mathieu, Lamé, and Allied Functions covers the fundamental problems and techniques of solution of periodic differential equations. This book is composed of 10 chapters that present important equations and the special functions they generate, ranging from Mathieu's equation to the intractable ellipsoidal wave equation.This book starts with a survey of the main problems related to the formation of periodic differential equations. The subsequent chapters deal with the general theory of Mathieu's equation, Mathieu functions of integral order, and

Detection of hot fallout on Taiwan in the period 1971-1975

International Nuclear Information System (INIS)

Weng, P.S.; Chu, T.C.; Hsu, C.N.; Su, S.J.

1977-01-01

The observation of fallout during the period of 1971-1975 is presented. Relatively high activity from nuclear tests at Lop Nor off mainland China was detected twice in this period. The gamma-ray spectrum of the hot fallout after the 11th nuclear test is given. The high activity peaks in the figures included are indicated with corresponding dates and sequence number of the tests for easy identification and comparison. The calibration of thermoluminescent dosimeters for the low exposure rates is presented. The gross beta activities are much more likely to build up in milk and surface water samples. Their intensity and duration are more significant than other foodstuff samples, and the timing of their appearance is more predictable. (author)

Air sampling with solid phase microextraction

Science.gov (United States)

Martos, Perry Anthony

There is an increasing need for simple yet accurate air sampling methods. The acceptance of new air sampling methods requires compatibility with conventional chromatographic equipment, and the new methods have to be environmentally friendly, simple to use, yet with equal, or better, detection limits, accuracy and precision than standard methods. Solid phase microextraction (SPME) satisfies the conditions for new air sampling methods. Analyte detection limits, accuracy and precision of analysis with SPME are typically better than with any conventional air sampling methods. Yet, air sampling with SPME requires no pumps, solvents, is re-usable, extremely simple to use, is completely compatible with current chromatographic equipment, and requires a small capital investment. The first SPME fiber coating used in this study was poly(dimethylsiloxane) (PDMS), a hydrophobic liquid film, to sample a large range of airborne hydrocarbons such as benzene and octane. Quantification without an external calibration procedure is possible with this coating. Well understood are the physical and chemical properties of this coating, which are quite similar to those of the siloxane stationary phase used in capillary columns. The log of analyte distribution coefficients for PDMS are linearly related to chromatographic retention indices and to the inverse of temperature. Therefore, the actual chromatogram from the analysis of the PDMS air sampler will yield the calibration parameters which are used to quantify unknown airborne analyte concentrations (ppb v to ppm v range). The second fiber coating used in this study was PDMS/divinyl benzene (PDMS/DVB) onto which o-(2,3,4,5,6- pentafluorobenzyl) hydroxylamine (PFBHA) was adsorbed for the on-fiber derivatization of gaseous formaldehyde (ppb v range), with and without external calibration. The oxime formed from the reaction can be detected with conventional gas chromatographic detectors. Typical grab sampling times were as small as 5 seconds

Quarterly RCRA Groundwater Monitoring Data for the Period April Through June 2006

Energy Technology Data Exchange (ETDEWEB)

Hartman, Mary J.

2006-11-01

This report provides information about RCRA groundwater monitoring for the period April through June 2006. Seventeen RCRA sites were sampled during the reporting quarter. Sampled sites include seven monitored under groundwater indicator evaluation (''detection'') programs, eight monitored under groundwater quality assessment programs, and two monitored under final-status programs.

Radioactivity monitoring of export/import samples - an update

International Nuclear Information System (INIS)

Shukla, V.K.; Murthy, M.V.R.; Sartandel, S.J.; Negi, B.S.; Sadasivan, S.

2001-01-01

137 Cs activity was measured in food samples exported from and imported into India during the period from 1993 to 2000. At present, on an average of about 1200 sample are estimated every year. Results showed no contamination of 137 Cs activity in samples that are exported from India. The few samples of diary products, imported in India during 1995 and 1996, showed low levels of 137 Cs activity. However, the levels were well with in the permissible values of Atomic Energy Regulatory Board (AERB). (author)

Periodic materials-based vibration attenuation in layered foundations: experimental validation

International Nuclear Information System (INIS)

Xiang, H J; Shi, Z F; Wang, S J; Mo, Y L

2012-01-01

Guided by the recent advances in solid-state research in periodic materials, a new type of layered periodic foundation consisting of concrete and rubber layers is experimentally investigated in this paper. The distinct feature of this new foundation is its frequency band gaps. When the frequency contents of a wave fall within the range of the frequency band gaps, the wave, and hence its energy, will be weakened or cannot propagate through the foundation, so the foundation itself can serve as a vibration isolator. Using the theory of elastodynamics and the Bloch–Floquet theorem, the mechanism of band gaps in periodic composites is presented, and a finite element model is built to show the isolation characteristic of a finite dimensional periodic foundation. Based on these analytical results, moreover, a scaled model frame and a periodic foundation were fabricated and shake table tests of the frame on the periodic foundation were performed. Ambient, strong and harmonic vibration attenuations are found when the exciting frequencies fall into the band gaps. (fast track communication)

Two-Phase Gas-Liquid Flow Structure Characteristics under Periodic Cross Forces Action

Directory of Open Access Journals (Sweden)

V. V. Perevezentsev

2015-01-01

Full Text Available The article presents a study of two-phase gas-liquid flow under the action of periodic cross forces. The work objective is to obtain experimental data for further analysis and have structure characteristics of the two-phase flow movement. For research, to obtain data without disturbing effect on the flow were used optic PIV (Particle Image Visualization methods because of their noninvasiveness. The cross forces influence was provided by an experimental stand design to change the angular amplitudes and the periods of channel movement cycle with two-phase flow. In the range of volume gas rates was shown a water flow rate versus the inclination angle of immovable riser section and the characteristic angular amplitudes and periods of riser section inclination cycle under periodic cross forces. Data on distribution of average water velocity in twophase flow in abovementioned cases were also obtained. These data allowed us to draw a conclusion that a velocity distribution depends on the angular amplitude and on the period of the riser section roll cycle. This article belongs to publications, which study two-phase flows with no disturbing effect on them. Obtained data give an insight into understanding a pattern of twophase gas-liquid flow under the action of periodic cross forces and can be used to verify the mathematical models of the CFD thermo-hydraulic codes. In the future, the work development expects taking measurements with more frequent interval in the ranges of angular amplitudes and periods of the channel movement cycle and create a mathematical model to show the action of periodic cross forces on two-phase gas-liquid flow.

THEORETICAL CEPHEID PERIOD-LUMINOSITY AND PERIOD-COLOR RELATIONS IN SPITZER IRAC BANDS

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Ngeow, Chow-Choong [Graduate Institute of Astronomy, National Central University, Jhongli City 32001, Taiwan (China); Marconi, Marcella; Musella, Ilaria [Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli (Italy); Cignoni, Michele [Department of Astronomy, Bologna University, via Ranzani 1, 40127 Bologna (Italy); Kanbur, Shashsi M. [Department of Physics, State University of New York at Oswego, Oswego, NY 13126 (United States)

2012-02-01

In this paper, the synthetic period-luminosity (P-L) relations in Spitzer's IRAC bands, based on a series of theoretical pulsation models with varying metal and helium abundance, were investigated. Selected sets of these synthetic P-L relations were compared to the empirical IRAC band P-L relations recently determined from Galactic and Magellanic Clouds Cepheids. For the Galactic case, synthetic P-L relations from model sets with (Y = 0.26, Z = 0.01), (Y = 0.26, Z = 0.02), and (Y = 0.28, Z = 0.02) agree with the empirical Galactic P-L relations derived from the Hubble Space Telescope parallaxes. For Magellanic Cloud Cepheids, the synthetic P-L relations from model sets with (Y = 0.25, Z = 0.008) agree with both of the empirical Large Magellanic Cloud (LMC) and Small Magellanic Cloud P-L relations. Analysis of the synthetic P-L relations from all model sets suggested that the IRAC band P-L relations may not be independent of metallicity, as the P-L slopes and intercepts could be affected by the metallicity and/or helium abundance. We also derive the synthetic period-color (P-C) relations in the IRAC bands. Non-vanishing synthetic P-C relations were found for certain combinations of IRAC band filters and metallicity. However, the synthetic P-C relations disagreed with the [3.6]-[8.0] P-C relation recently found for the Galactic Cepheids. The synthetic [3.6]-[4.5] P-C slope from the (Y = 0.25, Z = 0.008) model set, on the other hand, is in excellent agreement to the empirical LMC P-C counterpart, if a period range 1.0 < log (P) < 1.8 is adopted.

Measurements of short-range ordering in Ni3Al

International Nuclear Information System (INIS)

Okamoto, J.K.; Ahn, C.C.

1992-01-01

This paper reports on extended electron energy-loss fine structure (EXELFS) that has been used to measure short-range ordering in Ni 3 Al. Films of fcc Ni 3 Al with suppressed short-range order synthesized by vacuum evaporation of Ni 3 Al onto room temperature substrates. EXELFS data were taken from both Al K and Ni L 23 edges. The development of short-range order was observed after the samples were annealed for various times at temperatures below 350 degrees C. Upon comparison with ab initio planewave EXELFS calculations, it was found that the Warren-Cowley short-range order parameter a(1nn) changed by about -0.1 after 210 minutes of annealing at 150 degrees C

Results of groundwater monitoring and vegetation sampling at Everest, Kansas, in 2009 .

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, L. M.; Environmental Science Division

2010-05-13

In April 2008, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) conducted groundwater sampling for the analysis of volatile organic compounds (VOCs) in the existing network of monitoring points at Everest, Kansas (Argonne 2008). The objective of the 2008 investigation was to monitor the distribution of carbon tetrachloride contamination in groundwater previously identified in CCC/USDA site characterization and groundwater sampling studies at Everest in 2000-2006 (Argonne 2001, 2003, 2006a,b). The work at Everest is being undertaken on behalf of the CCC/USDA by Argonne National Laboratory, under the oversight of the Kansas Department of Health and Environment (KDHE). The findings of the 2008 investigation were as follows: (1) Measurements of groundwater levels obtained manually and through the use of automatic recorders demonstrated a consistent pattern of groundwater flow - and inferred contaminant migration - to the north-northwest from the former CCC/USDA facility toward the Nigh property, and then west-southwest from the Nigh property toward the intermittent creek that lies west of the former CCC/USDA facility and the Nigh property. (2) The range of concentrations and the areal distribution of carbon tetrachloride identified in the groundwater at Everest in April 2008 were generally consistent with previous results. The results of the 2008 sampling (reflecting the period from 2006 to 2008) and the earlier investigations at Everest (representing the period from 2000 to 2006) show that no significant downgradient extension of the carbon tetrachloride plume occurred from 2000 to 2008. (3) The slow contaminant migration indicated by the monitoring data is qualitatively consistent with the low groundwater flow rates in the Everest aquifer unit estimated previously on the basis of site-specific hydraulic testing (Argonne 2006a,b). (4) The April 2008 and earlier sampling results demonstrate that the limits of the plume have been

Reference Ranges of Serum Blood Urea Nitrogen, Creatinine Concentration and Ultrasonographic Measurement of the Kidneys in Term Healthy Newborns in the Neonatal Period

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Şebnem Kader

2017-12-01

Full Text Available Objective: Acute kidney injury is an important problem in neonates. We conducted a cross-sectional prospective study to determine normal serum blood urea nitrogen, creatinine reference ranges and ranges of ultrasonographic measurement of kidneys in healthy term newborns. Study Design: Blood samples were collected from total 357 healthy newborns at birth (n=45, 1st (n=30, 3rd (n=61, 7th (n=34, 10th (n=132, 14th (n=36, and 28th (n=19 days of life. Renal ultrasonographic was performed by the same two radiologists on 81 newborns aged 10 days. Results: Serum blood urea nitrogen and creatinine concentrations have reached to the highest level at the first day of life and have returned to cord level at the third day of life. There were gradually decrease in serum blood urea nitrogen and creatinine levels after the first day of life. There were significant difference in both right and left renal length, width, and volumes in terms of gender and these parameters were statistically higher in boys than girls (p<0.05. Birth weight of the boys (3548±539g was statistically higher than girls (3307±405 g (p=0.028. There was a positive correlation between birth weight and right (r=0.38, p=0.000 and left kidney volumes (r=0.44, p=0.000. Conclusion: Our findings showed that measured blood urea nitrogen and creatinine levels changed in accordance with postnatal days and there was a positive correlation between kidney volume and birth weight of newborns. We concluded that these findings are important for evaluation of acute kidney injury and for screening of for urinary tract anomalies in neonates

Formation of the Periotic Space During the Early Fetal Period in Humans.

Science.gov (United States)

Ishikawa, Aoi; Ohtsuki, Sae; Yamada, Shigehito; Uwabe, Chigako; Imai, Hirohiko; Matsuda, Tetsuya; Takakuwa, Tetsuya

2018-04-01

The inner ear is a very complicated structure, composed of a bony labyrinth (otic capsule; OC), membranous labyrinth, with a space between them, named the periotic labyrinth or periotic space. We investigated how periotic tissue fluid spaces covered the membranous labyrinth three-dimensionally, leading to formation of the periotic labyrinth encapsulated in the OC during human fetal development. Digital data sets from magnetic resonance images and phase-contrast X-ray tomography images of 24 inner ear organs from 24 human fetuses from the Kyoto Collection (fetuses in trimesters 1 and 2; crown-rump length: 14.4-197 mm) were analyzed. The membranous labyrinth was morphologically differentiated in samples at the end of the embryonic period (Carnegie stage 23), and had grown linearly to more than eight times in size during the observation period. The periotic space was first detected at the 35-mm samples, around the vestibule and basal turn of the cochlea, which elongated rapidly to the tip of the cochlea and semicircular ducts, successively, and almost covered the membranous labyrinth at the 115-mm CRL stage or later. In those samples, several ossification centers were detected around the space. This article thus demonstrated that formation of the membranous labyrinth, periotic space (labyrinth), and ossification of the OC occurs successively, according to an intricate timetable. Anat Rec, 301:563-570, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Portable Automation of Static Chamber Sample Collection for Quantifying Soil Gas Flux

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Davis, Morgan P.; Groh, Tyler A.; Parkin, Timothy B.; Williams, Ryan J.; Isenhart, Thomas M.; Hofmockel, Kirsten S.

2018-01-01