Science.gov

Sample records for 5-ppbv reporting cutoff

  1. 15 CFR 70.3 - Effect of boundary changes occurring or reported after the cutoff dates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE CUTOFF DATES FOR RECOGNITION OF BOUNDARY CHANGES FOR THE 2010 CENSUS § 70.3 Effect of boundary changes occurring or reported after the cutoff dates. The Bureau of the Census will not recognize changes in boundaries that...

  2. 15 CFR 70.3 - Effect of boundary changes occurring or reported after the cutoff dates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE CUTOFF DATES FOR RECOGNITION OF BOUNDARY CHANGES FOR THE 2010 CENSUS § 70.3 Effect of boundary changes occurring or reported after the cutoff dates. The Bureau of the Census will not recognize changes in boundaries that...

  3. 15 CFR 70.3 - Effect of boundary changes occurring or reported after the cutoff dates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE CUTOFF DATES FOR RECOGNITION OF BOUNDARY CHANGES FOR THE 2010 CENSUS § 70.3 Effect of boundary changes occurring or reported after the cutoff dates. The Bureau of the Census will not recognize changes in boundaries that...

  4. 15 CFR 70.3 - Effect of boundary changes occurring or reported after the cutoff dates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE CUTOFF DATES FOR RECOGNITION OF BOUNDARY CHANGES FOR THE 2010 CENSUS § 70.3 Effect of boundary changes occurring or reported after the cutoff dates. The Bureau of the Census will not recognize changes in boundaries that...

  5. 15 CFR 70.3 - Effect of boundary changes occurring or reported after the cutoff dates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE CUTOFF DATES FOR RECOGNITION OF BOUNDARY CHANGES FOR THE 2010 CENSUS § 70.3 Effect of boundary changes occurring or reported after the cutoff dates. The Bureau of the Census will not recognize changes in boundaries that...

  6. STS-114 Engine Cut-off Sensor Anomaly Technical Consultation Report

    NASA Technical Reports Server (NTRS)

    Wilson, Timmy R.; Kichak, Robert A.; Ungar, Eugene K.; Cherney, Robert; Rickman, Steve L.

    2009-01-01

    The NESC consultation team participated in real-time troubleshooting of the Main Propulsion System (MPS) Engine Cutoff (ECO) sensor system failures during STS-114 launch countdown. The team assisted with External Tank (ET) thermal and ECO Point Sensor Box (PSB) circuit analyses, and made real-time inputs to the Space Shuttle Program (SSP) problem resolution teams. Several long-term recommendations resulted. One recommendation was to conduct cryogenic tests of the ECO sensors to validate, or disprove, the theory that variations in circuit impedance due to cryogenic effects on swaged connections within the sensor were the root cause of STS-114 failures.

  7. Epidemiologic Behavior and Estimation of an Optimal Cut-Off Point for Homeostasis Model Assessment-2 Insulin Resistance: A Report from a Venezuelan Population

    PubMed Central

    Bermúdez, Valmore; Martínez, María Sofía; Apruzzese, Vanessa; Chávez-Castillo, Mervin; Gonzalez, Robys; Torres, Yaquelín; Bello, Luis; Añez, Roberto; Chacín, Maricarmen; Toledo, Alexandra; Cabrera, Mayela; Mengual, Edgardo; Ávila, Raquel; López-Miranda, José

    2014-01-01

    Background. Mathematical models such as Homeostasis Model Assessment have gained popularity in the evaluation of insulin resistance (IR). The purpose of this study was to estimate the optimal cut-off point for Homeostasis Model Assessment-2 Insulin Resistance (HOMA2-IR) in an adult population of Maracaibo, Venezuela. Methods. Descriptive, cross-sectional study with randomized, multistaged sampling included 2,026 adult individuals. IR was evaluated through HOMA2-IR calculation in 602 metabolically healthy individuals. For cut-off point estimation, two approaches were applied: HOMA2-IR percentile distribution and construction of ROC curves using sensitivity and specificity for selection. Results. HOMA2-IR arithmetic mean for the general population was 2.21 ± 1.42, with 2.18 ± 1.37 for women and 2.23 ± 1.47 for men (P = 0.466). When calculating HOMA2-IR for the healthy reference population, the resulting p75 was 2.00. Using ROC curves, the selected cut-off point was 1.95, with an area under the curve of 0.801, sensibility of 75.3%, and specificity of 72.8%. Conclusions. We propose an optimal cut-off point of 2.00 for HOMA2-IR, offering high sensitivity and specificity, sufficient for proper assessment of IR in the adult population of our city, Maracaibo. The determination of population-specific cut-off points is needed to evaluate risk for public health problems, such as obesity and metabolic syndrome. PMID:27379332

  8. Overview of Cotinine Cutoff Values for Smoking Status Classification

    PubMed Central

    Kim, Sungroul

    2016-01-01

    While cotinine is commonly used as a biomarker to validate self-reported smoking status, the selection of an optimal cotinine cutoff value for distinguishing true smokers from true nonsmokers shows a lack of standardization among studies. This review describes how the cutoff values have been derived, and explains the issues involved in the generalization of a cutoff value. In this study, we conducted an English-language literature search in PubMed using the keywords “cotinine” and “cutoff” or “self-reported” and “smoking status” and “validation” for the years 1985–2014. We obtained 104 articles, 32 of which provided (1) sensitivity and specificity of a cutoff value and (2) determination methods for the given cutoff value. We found that the saliva cotinine cutoff value range of 10–25 ng/mL, serum and urine cotinine cutoff of 10–20 ng/mL and 50–200 ng/mL, respectively, have been commonly used to validate self-reported smoking status using a 2 × 2 table or a receiver operating characteristics (ROC) curve. We also found that recent large population-based studies in the U.S. and UK reported lower cutoff values for cotinine in serum (3 ng/mL) and saliva (12 ng/mL), compared to the traditionally accepted ones (15 and 14 ng/mg, respectively). PMID:27983665

  9. Entropy-Driven Cutoff Phenomena

    NASA Astrophysics Data System (ADS)

    Lancia, Carlo; Nardi, Francesca R.; Scoppola, Benedetto

    2012-10-01

    In this paper we present, in the context of Diaconis' paradigm, a general method to detect the cutoff phenomenon. We use this method to prove cutoff in a variety of models, some already known and others not yet appeared in literature, including a non-reversible random walk on a cylindrical lattice. All the given examples clearly indicate that a drift towards the opportune quantiles of the stationary measure could be held responsible for this phenomenon. In the case of birth-and-death chains this mechanism is fairly well understood; our work is an effort to generalize this picture to more general systems, such as systems having stationary measure spread over the whole state space or systems in which the study of the cutoff may not be reduced to a one-dimensional problem. In those situations the drift may be looked for by means of a suitable partitioning of the state space into classes; using a statistical mechanics language it is then possible to set up a kind of energy-entropy competition between the weight and the size of the classes. Under the lens of this partitioning one can focus the mentioned drift and prove cutoff with relative ease.

  10. The cutoff phenomenon in finite Markov chains.

    PubMed Central

    Diaconis, P

    1996-01-01

    Natural mixing processes modeled by Markov chains often show a sharp cutoff in their convergence to long-time behavior. This paper presents problems where the cutoff can be proved (card shuffling, the Ehrenfests' urn). It shows that chains with polynomial growth (drunkard's walk) do not show cutoffs. The best general understanding of such cutoffs (high multiplicity of second eigenvalues due to symmetry) is explored. Examples are given where the symmetry is broken but the cutoff phenomenon persists. PMID:11607633

  11. A Cutoff for Blackbody Radiation

    NASA Astrophysics Data System (ADS)

    Cahill, M.

    2000-05-01

    An analysis of the statistical mechanics of spherical star clusters and the simpler case of monatomic ideal gases is known to reveal that the Michie-King globular cluster energy cutoff can be written as \\varepsilonc ln ( N ) /line\\varepsilon where \\varepsilonc is the cutoff energy, /line=\\varepsilon is the average energy, the masses are assumed identical and where the number of cluster stars or gas particles, N, is large. The statistical methods leading to this result are shown to work for a photon gas. The usual method of dividing phase space into cells each with Λ quantum compartments to which Bose-Einstein statistics apply is used. The resulting distribution law is D (Λ -1+Λ ρ ) -D ( Λ ρ ) =\\varepsilon/ \\varepsilono where D is the logarithmic derivative of the factorial function, \\varepsilon and \\varepsilon o are respectively the energy variable and an energy constant characterising the distribution and where ρ is the quantum compartment particle number density ρ =h3dn/dω , with\\ dω being the phase space volume element. The distributions ρ ( \\varepsilon /\\varrepsilono, Λ ) are shown to be a one parameter family of distributions which approach the Planck law as Λ approaches ∞ . For large Λ , the photon density falls to 0, where it is cut off, at \\varepsilon = \\varepsilonc ln ( Λ ) /line\\varrepsilon. If the energy of a photon gas is finite, there must be a frequency cutoff since photon energy is proportional to frequency. It follows that Λ is finite, it is shown that Λ N, and that the Planck law is an excellent approximation for its distribution except in the tail region. Also the last 2 equations imply equation 1 holds for the photon gas.

  12. Prevalence of swallowing and speech problems in daily life after chemoradiation for head and neck cancer based on cut-off scores of the patient-reported outcome measures SWAL-QOL and SHI.

    PubMed

    Rinkel, Rico N; Verdonck-de Leeuw, Irma M; Doornaert, Patricia; Buter, Jan; de Bree, Remco; Langendijk, Johannes A; Aaronson, Neil K; Leemans, C René

    2016-07-01

    The objective of this study is to assess swallowing and speech outcome after chemoradiation therapy for head and neck cancer, based on the patient-reported outcome measures Swallowing Quality of Life Questionnaire (SWAL-QOL) and Speech Handicap Index (SHI), both provided with cut-off scores. This is a cross-sectional study. Department of Otolaryngology/Head and Neck Surgery of a University Medical Center. Sixty patients, 6 months to 5 years after chemoradiation for head and neck squamous cell carcinoma. Swallowing Quality of Life Questionnaire (SWAL-QOL) and SHI, both validated in Dutch and provided with cut-off scores. Associations were tested between the outcome measures and independent variables (age, gender, tumor stage and site, and radiotherapy technique, time since treatment, comorbidity and food intake). Fifty-two patients returned the SWAL-QOL and 47 the SHI (response rate 87 and 78 %, respectively). Swallowing and speech problems were present in 79 and 55 %, respectively. Normal food intake was noticed in 45, 35 % had a soft diet and 20 % tube feeding. Patients with soft diet and tube feeding reported more swallowing problems compared to patients with normal oral intake. Tumor subsite was significantly associated with swallowing outcome (less problems in larynx/hypopharynx compared to oral/oropharynx). Radiation technique was significantly associated with psychosocial speech problems (less problems in patients treated with IMRT). Swallowing and (to a lesser extent) speech problems in daily life are frequently present after chemoradiation therapy for head and neck cancer. Future prospective studies will give more insight into the course of speech and swallowing problems after chemoradiation and into efficacy of new radiation techniques and swallowing and speech rehabilitation programs.

  13. A Review of Cutoffs for Nutritional Biomarkers.

    PubMed

    Raghavan, Ramkripa; Ashour, Fayrouz Sakr; Bailey, Regan

    2016-01-01

    The nutritional status of an individual or population needs to be assessed through valid and reliable biomarkers. Cutoffs generally have an underlying relation to health status and are one of the important quantitative criteria against which biomarker outputs are compared. For this reason, cutoffs are integral for surveys, surveillance, screening, interventions, monitoring, and evaluation. Despite their importance, nutritional biomarker cutoffs have not been adequately addressed in the literature. Furthermore, the field has not reached a consensus on which cutoff to use for each biomarker, and different cutoffs are often used for the same biomarkers in published studies. This review provides a comprehensive overview of cutoffs related to nutritional biomarkers and highlights some of the high-priority research gaps and challenges of using micronutrient case studies.

  14. Supplemental Summary of Cutoff Rigidities Calculated Using the International Geomagnetic Reference Field for Various Epochs.

    DTIC Science & Technology

    1982-11-01

    Rigidities Calculated Using the International -Geomagnetic Reference Field for Various Epochs M.A. SHEA D.F. SMART 1 NOVEMBER 1982 Approved for publie...SUMMARY OF CUTOFF Scientific. Interim. RIGIDITIES CALCULATED USING THE INTER -_ _________ NATIONAL GEOMAGNETIC REFERENCE FIELD 6 PERFORMING 01G. REPORT...n-b.’I Cosmic rays Cutoff rigidities Geomagnetic field 20 ABSTRACT (ContinuC0 e o, sid. it ---. 0, -,d id- 5,.- 550,5- Tables of cosmic-ray cutoff

  15. On Saturnian cosmic ray cutoff rigidities

    NASA Astrophysics Data System (ADS)

    Sauer, H. H.

    1980-03-01

    It has been determined that Saturn possesses a relatively pure dipolar magnetic field through magnetometer measurements made by Ness et al. (1979, private comm.) and Smith et al. (1979). The paper briefly outlines the dipole geomagnetic cutoff theory and demonstrates the scaling required for its applicability to energetic particle measurements in the vicinity of Saturn. Since the cutoff rigidity is a function of viewing direction, the effective cutoff rigidity must be determined as an integration over the finite viewing angle of a physical detector.

  16. Speed of pulled fronts with a cutoff.

    PubMed

    Benguria, R D; Depassier, M C

    2007-05-01

    We study the effect of a small cutoff epsilon on the velocity of a pulled front in one dimension by means of a variational principle. We obtain a lower bound on the speed dependent on the cutoff, for which the two leading order terms correspond to the Brunet-Derrida expression. To do so we cast a known variational principle for the speed of propagation of fronts in different variables which makes it more suitable for applications.

  17. Speed of pulled fronts with a cutoff

    NASA Astrophysics Data System (ADS)

    Benguria, R. D.; Depassier, M. C.

    2007-05-01

    We study the effect of a small cutoff γ on the velocity of a pulled front in one dimension by means of a variational principle. We obtain a lower bound on the speed dependent on the cutoff, for which the two leading order terms correspond to the Brunet-Derrida expression. To do so we cast a known variational principle for the speed of propagation of fronts in different variables which makes it more suitable for applications.

  18. Using Empirical Data to Set Cutoff Scores.

    ERIC Educational Resources Information Center

    Hills, John R.

    Six experimental approaches to the problems of setting cutoff scores and choosing proper test length are briefly mentioned. Most of these methods share the premise that a test is a random sample of items, from a domain associated with a carefully specified objective. Each item is independent and is scored zero or one, with no provision for…

  19. CMEs and frequency cutoff of solar bursts

    NASA Astrophysics Data System (ADS)

    Stanislavsky, Al.; Konovalenko, Al.; Koval, Ar.; Volvach, Y.; Zarka, P.

    2016-05-01

    Radio observations of solar bursts with high-frequency cutoff by the radio telescope UTR-2 (near Kharkiv, Ukraine) at 8-33 MHz on 17-19 August 2012 are presented. Such cutoff may be attributed to the emergence of the burst sources behind limb of the Sun with respect to an observer on the Earth. The events are strongly associated with solar eruptions occurred in a new active region. Ray tracing simulations show that the CMEs play a constructive role for the behind-limb bursts to be detected in ground-based observations. Likely, due to tunnel-like cavities with low density in CMEs, the radio emission of behind-limb solar bursts can be directed towards the Earth.

  20. Cutoff lensing: predicting catalytic sites in enzymes

    NASA Astrophysics Data System (ADS)

    Aubailly, Simon; Piazza, Francesco

    2015-10-01

    Predicting function-related amino acids in proteins with unknown function or unknown allosteric binding sites in drug-targeted proteins is a task of paramount importance in molecular biomedicine. In this paper we introduce a simple, light and computationally inexpensive structure-based method to identify catalytic sites in enzymes. Our method, termed cutoff lensing, is a general procedure consisting in letting the cutoff used to build an elastic network model increase to large values. A validation of our method against a large database of annotated enzymes shows that optimal values of the cutoff exist such that three different structure-based indicators allow one to recover a maximum of the known catalytic sites. Interestingly, we find that the larger the structures the greater the predictive power afforded by our method. Possible ways to combine the three indicators into a single figure of merit and into a specific sequential analysis are suggested and discussed with reference to the classic case of HIV-protease. Our method could be used as a complement to other sequence- and/or structure-based methods to narrow the results of large-scale screenings.

  1. Cutoff lensing: predicting catalytic sites in enzymes.

    PubMed

    Aubailly, Simon; Piazza, Francesco

    2015-10-08

    Predicting function-related amino acids in proteins with unknown function or unknown allosteric binding sites in drug-targeted proteins is a task of paramount importance in molecular biomedicine. In this paper we introduce a simple, light and computationally inexpensive structure-based method to identify catalytic sites in enzymes. Our method, termed cutoff lensing, is a general procedure consisting in letting the cutoff used to build an elastic network model increase to large values. A validation of our method against a large database of annotated enzymes shows that optimal values of the cutoff exist such that three different structure-based indicators allow one to recover a maximum of the known catalytic sites. Interestingly, we find that the larger the structures the greater the predictive power afforded by our method. Possible ways to combine the three indicators into a single figure of merit and into a specific sequential analysis are suggested and discussed with reference to the classic case of HIV-protease. Our method could be used as a complement to other sequence- and/or structure-based methods to narrow the results of large-scale screenings.

  2. Cutoff lensing: predicting catalytic sites in enzymes

    PubMed Central

    Aubailly, Simon; Piazza, Francesco

    2015-01-01

    Predicting function-related amino acids in proteins with unknown function or unknown allosteric binding sites in drug-targeted proteins is a task of paramount importance in molecular biomedicine. In this paper we introduce a simple, light and computationally inexpensive structure-based method to identify catalytic sites in enzymes. Our method, termed cutoff lensing, is a general procedure consisting in letting the cutoff used to build an elastic network model increase to large values. A validation of our method against a large database of annotated enzymes shows that optimal values of the cutoff exist such that three different structure-based indicators allow one to recover a maximum of the known catalytic sites. Interestingly, we find that the larger the structures the greater the predictive power afforded by our method. Possible ways to combine the three indicators into a single figure of merit and into a specific sequential analysis are suggested and discussed with reference to the classic case of HIV-protease. Our method could be used as a complement to other sequence- and/or structure-based methods to narrow the results of large-scale screenings. PMID:26445900

  3. Optimal cut-off values and population means of waist circumference in different populations.

    PubMed

    Wang, Zhiqiang; Ma, Jun; Si, Damin

    2010-12-01

    Abdominal obesity is a risk factor for cardiometabolic disease, and has become a major public health problem in the world. Waist circumference is generally used as a simple surrogate marker to define abdominal obesity for population screening. An increasing number of publications solely rely on the method that maximises sensitivity and specificity to define 'optimal' cut-off values. It is well documented that the optimal cut-off values of waist circumference vary across different ethnicities. However, it is not clear if the variation in cut-off values is a true biological phenomenon or an artifact of the method for identifying optimal cut-off points. The objective of the present review was to assess the relationship between optimal cut-offs and population waist circumference levels. Among sixty-one research papers, optimal cut-off values ranged from 65·5 to 101·2 cm for women and 72·5 to 103·0 cm for men. Reported optimal cut-off values were highly correlated with population means (correlation coefficient: 0·91 for men and 0·93 for women). Such a strong association was independent of waist circumference measurement techniques or the health outcomes (dyslipidaemia, hypertension or hyperglycaemia), and existed in some homogeneous populations such as the Chinese and Japanese. Our findings raised some concerns about applying the sensitivity and specificity approach to determine cut-off values. Further research is needed to understand whether the differences among populations in waist circumference were genetically or environmentally determined, and to understand whether using region-specific cut-off points can identify individuals with the same absolute risk levels of metabolic and cardiovascular outcomes among different populations.

  4. 49 CFR 229.93 - Safety cut-off device.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Safety cut-off device. 229.93 Section 229.93 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Equipment § 229.93 Safety cut-off device. The fuel line shall have a safety cut-off device that— (a)...

  5. 49 CFR 229.93 - Safety cut-off device.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Safety cut-off device. 229.93 Section 229.93 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Equipment § 229.93 Safety cut-off device. The fuel line shall have a safety cut-off device that— (a)...

  6. Power Analysis of Cutoff-Based Randomized Clinical Trials.

    ERIC Educational Resources Information Center

    Cappelleri, Joseph C.; And Others

    1994-01-01

    A statistical power algorithm based on the Fisher Z method is developed for cutoff-based random clinical trials and the single cutoff-point (regression-discontinuity) design that has no randomization. This article quantifies power and sample size estimates for various levels of power and cutoff-based assignment. (Author/SLD)

  7. Anesthesia cutoff phenomenon: Interfacial hydrogen bonding

    SciTech Connect

    Chiou, J.S.; Ma, S.M.; Kamaya, H.; Ueda, I. )

    1990-05-04

    Anesthesia cutoff refers to the phenomenon of loss of anesthetic potency in a homologous series of alkanes and their derivatives when their sizes become too large. In this study, hydrogen bonding of 1-alkanol series (ethanol to eicosanol) to dipalmitoyl-L-alpha-phosphatidylcholine (DPPC) was studied by Fourier transform infrared spectroscopy (FTIR) in DPPC-D2O-in-CCl4 reversed micelles. The alkanols formed hydrogen bonds with the phosphate moiety of DPPC and released the DPPC-bound deuterated water, evidenced by increases in the bound O-H stretching signal of the alkanol-DPPC complex and also in the free O-D stretching band of unbound D2O. These effects increased according to the elongation of the carbon chain of 1-alkanols from ethanol (C2) to 1-decanol (C10), but suddenly almost disappeared at 1-tetradecanol (C14). Anesthetic potencies of these alkanols, estimated by the activity of brine shrimps, were linearly related to hydrogen bond-breaking activities below C10 and agreed with the FTIR data in the cutoff at C10.

  8. Cutoff nonlinearities in the low-temperature vibrations of glasses and crystals

    NASA Astrophysics Data System (ADS)

    Mizuno, Hideyuki; Silbert, Leonardo E.; Sperl, Matthias; Mossa, Stefano; Barrat, Jean-Louis

    2016-04-01

    We present a computer simulation study of glassy and crystalline states using the standard Lennard-Jones interaction potential that is truncated at a finite cutoff distance, as is typical of many computer simulations. We demonstrate that the discontinuity at the cutoff distance in the first derivative of the potential (corresponding to the interparticle force) leads to the appearance of cutoff nonlinearities. These cutoff nonlinearities persist into the very-low-temperature regime thereby affecting low-temperature thermal vibrations, which leads to a breakdown of the harmonic approximation for many eigenmodes, particularly for low-frequency vibrational modes. Furthermore, while expansion nonlinearities which are due to higher order terms in the Taylor expansion of the interaction potential are usually ignored at low temperatures and show up as the temperature increases, cutoff nonlinearities can become most significant at the lowest temperatures. Anharmonic effects readily show up in the elastic moduli which not only depend on the eigenfrequencies, but are crucially sensitive to the eigenvectors of the normal modes. In contrast, those observables that rely mainly on static structural information or just the eigenfrequencies, such as the vibrational density of states, total potential energy, and specific heat, show negligible dependence on the presence of the cutoff. Similar aspects of nonlinear behavior have recently been reported in model granular materials, where the constituent particles interact through finite-range, purely repulsive potentials. These nonlinearities have been ascribed to the nature of the sudden cutoff at contact in the force law. As a consequence, we demonstrate that cutoff nonlinearities emerge as a general feature of ordered and disordered solid state systems interacting through truncated potentials.

  9. Aid cutoff threatens condom program in Pakistan.

    PubMed

    Barron, T

    1991-01-01

    The Pressler Amendment, a law prohibiting US assistance to any country that does not sign the UN Nuclear Nonproliferation Treaty, is forcing USAID to shut down its highly successful Social Marketing of Contraceptives (SMC) program in Pakistan. Adopted in 1985, the amendment calls for an end of funding for projects in Pakistan as of fiscal year 1991, since the country has refused to sign the treaty. Only previously committed funds have kept SMC running, but it may soon have a close shop. The cutoff comes at an especially inopportune time--just when SMC had begun to make an impact. Introduced 5 years ago, Sathi condoms (the project's main product) account for 2/3 of all condoms used in Pakistan. Sales jumped from 30 million in 1978 to 74 million last year. SMC administrators explain that the country has a vast potential for social marketing. But because of the cutoff in aid, the program will exhaust its supply of condoms by March 1992. The end of the SMC program will mean a serious setback for Pakistan, which already has the 2nd largest population in southern Asia, and which has double the fertility of the most populous country in the region, India. Only 7% of the women in Pakistan rely on a modern method of contraception, compared to 42% in India and 26% in Bangladesh. USAID officials explain that the organization is working with the Pakistani government to find ways to continue funding the program after US funds run out. They add that this development will provide Pakistani Prime Minister Nawaz Sharif an opportunity to demonstrate his stated commitment to curb population growth.

  10. Concentrated coal plant wastes contained with concrete cutoff

    SciTech Connect

    Not Available

    1984-03-01

    A 3-mile concrete cutoff wall around a huge scrubber-waste-disposal basin is being constructed in southeastern Montana. The $25-million cutoff is designed to seal highly pervious layers of baked shale surrounding the pond, protecting scarce groundwater reserves from the scrubber slurry generated by a power station 3 miles away. Groundwater contamination concerns led to the decision for the cutoff, which is made from interlocking concrete panels.

  11. High-Frequency Cutoff in Type III Bursts

    NASA Astrophysics Data System (ADS)

    Stanislavsky, A. A.; Konovalenko, A. A.; Volvach, Ya. S.; Koval, A. A.

    In this article we report about a group of solar bursts with high-frequency cutoff, observed on 19 August of 2012 near 8:23 UT, simultaneously by three different radio telescopes: the Ukrainian decameter radio telescope (8-33 MHz), the French Nancay Decametric Array (10-70 MHz) and the Italian San Vito Solar Observatory of RSTN (25-180 MHz). Morphologically the bursts are very similar to the type III bursts. The solar activity is connected with the emergency of a new group of solar spots on the far side of the Sun with respect to observers on Earth. The solar bursts accompany many moderate flares over eastern limb. The refraction of the behind-limb radio bursts towards the Earth is favorable, if CMEs generate low-density cavities in solar corona.

  12. Geomagnetic cutoffs: a review for space dosimetry applications.

    PubMed

    Smart, D F; Shea, M A

    1994-10-01

    The earth's magnetic field acts as a shield against charged particle radiation from interplanetary space, technically described as the geomagnetic cutoff. The cutoff rigidity problem (except for the dipole special case) has "no solution in closed form". The dipole case yields the Stormer equation which has been repeatedly applied to the earth in hopes of providing useful approximations of cutoff rigidities. Unfortunately the earth's magnetic field has significant deviations from dipole geometry, and the Stormer cutoffs are not adequate for most applications. By application of massive digital computer power it is possible to determine realistic geomagnetic cutoffs derived from high order simulation of the geomagnetic field. Using this technique, "world-grids" of directional cutoffs for the earth's surface and for a limited number of satellite altitudes have been derived. However, this approach is so expensive and time consuming it is impractical for most spacecraft orbits, and approximations must be used. The world grids of cutoff rigidities are extensively used as lookup tables, normalization points and interpolation aids to estimate the effective geomagnetic cutoff rigidity of a specific location in space. We review the various options for estimating the cutoff rigidity for earth-orbiting satellites.

  13. 49 CFR 40.87 - What are the cutoff concentrations for drug tests?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Codeine 2000 ng/mL. Morphine 2000 ng/mL. 6-Acetylmorphine 10 ng/mL 6-Acetylmorphine 10 ng/mL...-tetrahydrocannabinol-9-carboxylic acid (THCA). 2 Morphine is the target analyte for codeine/morphine testing. 3 Either... the cutoff concentration as confirmed positive. (d) You must report quantitative values for...

  14. 49 CFR 40.87 - What are the cutoff concentrations for drug tests?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Codeine 2000 ng/mL. Morphine 2000 ng/mL. 6-Acetylmorphine 10 ng/mL 6-Acetylmorphine 10 ng/mL...-tetrahydrocannabinol-9-carboxylic acid (THCA). 2 Morphine is the target analyte for codeine/morphine testing. 3 Either... the cutoff concentration as confirmed positive. (d) You must report quantitative values for...

  15. 49 CFR 40.87 - What are the cutoff concentrations for drug tests?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Codeine 2000 ng/mL. Morphine 2000 ng/mL. 6-Acetylmorphine 10 ng/mL 6-Acetylmorphine 10 ng/mL...-tetrahydrocannabinol-9-carboxylic acid (THCA). 2 Morphine is the target analyte for codeine/morphine testing. 3 Either... the cutoff concentration as confirmed positive. (d) You must report quantitative values for...

  16. 49 CFR 40.87 - What are the cutoff concentrations for drug tests?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Codeine 2000 ng/mL. Morphine 2000 ng/mL. 6-Acetylmorphine 10 ng/mL 6-Acetylmorphine 10 ng/mL...-tetrahydrocannabinol-9-carboxylic acid (THCA). 2 Morphine is the target analyte for codeine/morphine testing. 3 Either... the cutoff concentration as confirmed positive. (d) You must report quantitative values for...

  17. 49 CFR 40.87 - What are the cutoff concentrations for drug tests?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Codeine 2000 ng/mL. Morphine 2000 ng/mL. 6-Acetylmorphine 10 ng/mL 6-Acetylmorphine 10 ng/mL...-tetrahydrocannabinol-9-carboxylic acid (THCA). 2 Morphine is the target analyte for codeine/morphine testing. 3 Either... the cutoff concentration as confirmed positive. (d) You must report quantitative values for...

  18. Geomagnetic Cutoff Rigidity Computer Program: Theory, Software Description and Example

    NASA Technical Reports Server (NTRS)

    Smart, D. F.; Shea, M. A.

    2001-01-01

    The access of charged particles to the earth from space through the geomagnetic field has been of interest since the discovery of the cosmic radiation. The early cosmic ray measurements found that cosmic ray intensity was ordered by the magnetic latitude and the concept of cutoff rigidity was developed. The pioneering work of Stoermer resulted in the theory of particle motion in the geomagnetic field, but the fundamental mathematical equations developed have 'no solution in closed form'. This difficulty has forced researchers to use the 'brute force' technique of numerical integration of individual trajectories to ascertain the behavior of trajectory families or groups. This requires that many of the trajectories must be traced in order to determine what energy (or rigidity) a charged particle must have to penetrate the magnetic field and arrive at a specified position. It turned out the cutoff rigidity was not a simple quantity but had many unanticipated complexities that required many hundreds if not thousands of individual trajectory calculations to solve. The accurate calculation of particle trajectories in the earth's magnetic field is a fundamental problem that limited the efficient utilization of cosmic ray measurements during the early years of cosmic ray research. As the power of computers has improved over the decades, the numerical integration procedure has grown more tractable, and magnetic field models of increasing accuracy and complexity have been utilized. This report is documentation of a general FORTRAN computer program to trace the trajectory of a charged particle of a specified rigidity from a specified position and direction through a model of the geomagnetic field.

  19. 14 CFR § 1214.1103 - Application cutoff date.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Application cutoff date. § 1214.1103 Section § 1214.1103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1103 Application cutoff date. (a) The...

  20. 14 CFR 1214.1103 - Application cutoff date.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Application cutoff date. 1214.1103 Section 1214.1103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1103 Application cutoff date. (a) The...

  1. 14 CFR 1214.1103 - Application cutoff date.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Application cutoff date. 1214.1103 Section 1214.1103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1103 Application cutoff date. (a) The...

  2. 14 CFR 1214.1103 - Application cutoff date.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Application cutoff date. 1214.1103 Section 1214.1103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1103 Application cutoff date. (a) The...

  3. 14 CFR 1214.1103 - Application cutoff date.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Application cutoff date. 1214.1103 Section 1214.1103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1103 Application cutoff date. (a) The...

  4. LOOKING DOWNSTREAM FROM KACHESS DAM CREST, 1910 RIVER CUTOFF CHANNEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOOKING DOWNSTREAM FROM KACHESS DAM CREST, 1910 RIVER CUTOFF CHANNEL WITH CRIB STRUCTURE IN CENTER. BRIDGE FOOTING CRIB STRUCTURE AT RIGHT (Upstream face of Kachess Dam in foreground) - Kachess Dam, Cutoff Channel and Crib Structures, Kachess River, 1.5 miles north of Interstate 90, Easton, Kittitas County, WA

  5. Quasi-chemical theory with a soft cutoff

    SciTech Connect

    Chempath, Shaji; Pratt, Lawrence R; Paulaitis, Michael E

    2008-01-01

    In view of the wide success of molecular quasichemical theory of liquids, this paper develops the soft-cutoff version of that theory. This development allows molecular dynamics simulations to be used for the calculation of solvation free energy, whereas the hard-cutoff version of the theory needs Monte Carlo simulations. This development also shows how fluids composed of molecules with smooth repulsive interactions can be treated analogously to the molecular-field theory of the hard-sphere fluid. In the treatment of liquid water, quasichemical theory with soft-cutoff conditioning does not change the fundamental convergence characteristics of the theory using hard-cutoff conditioning. In fact, hard cutoffs are found here to work better than softer ones in that case.

  6. Measurement of electron density using reactance cutoff probe

    NASA Astrophysics Data System (ADS)

    You, K. H.; You, S. J.; Kim, D. W.; Na, B. K.; Seo, B. H.; Kim, J. H.; Seong, D. J.; Chang, H. Y.

    2016-05-01

    This paper proposes a new measurement method of electron density using the reactance spectrum of the plasma in the cutoff probe system instead of the transmission spectrum. The highly accurate reactance spectrum of the plasma-cutoff probe system, as expected from previous circuit simulations [Kim et al., Appl. Phys. Lett. 99, 131502 (2011)], was measured using the full two-port error correction and automatic port extension methods of the network analyzer. The electron density can be obtained from the analysis of the measured reactance spectrum, based on circuit modeling. According to the circuit simulation results, the reactance cutoff probe can measure the electron density more precisely than the previous cutoff probe at low densities or at higher pressure. The obtained results for the electron density are presented and discussed for a wide range of experimental conditions, and this method is compared with previous methods (a cutoff probe using the transmission spectrum and a single Langmuir probe).

  7. Gauge invariance in the presence of a cutoff

    SciTech Connect

    Kvinikhidze, A. N.; Blankleider, B.; Epelbaum, E.; Hanhart, C.; Valderrama, M. Pavon

    2009-10-15

    We use the method of gauging equations to construct the electromagnetic current operator for the two-nucleon system in a theory with a finite cutoff. The employed formulation ensures that the two-nucleon T-matrix and corresponding five-point function, in the cutoff theory, are identical to the ones formally defined by a reference theory without a cutoff. A feature of our approach is that it effectively introduces a cutoff into the reference theory in a way that maintains the long-range part of the exchange current operator; for applications to effective field theory (EFT), this property is usually sufficient to guarantee the predictive power of the resulting cutoff theory. In addition, our approach leads to Ward-Takahashi (WT) identities that are linear in the interactions. From the point of view of EFT's where such a WT identity is satisfied in the reference theory, this ensures that gauge invariance in the cutoff theory is maintained order by order in the expansion.

  8. Caregivers feeding styles questionnaire. Establishing cutoff points

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Researchers use the Caregiver's Feeding Styles Questionnaire (CFSQ) to categorize parent feeding into authoritative, authoritarian, indulgent, and uninvolved styles. The CFSQ assesses self-reported feeding and classifies parents using median splits which are used in a substantial body of parenting l...

  9. Determination of Phenotypic Resistance Cutoffs From Routine Clinical Data

    PubMed Central

    Walter, Hauke; Pfeifer, Nico; Knops, Elena; Lübke, Nadine; Büch, Joachim; Di Giambenedetto, Simona; Kaiser, Rolf; Lengauer, Thomas

    2017-01-01

    Background: HIV-1 drug resistance can be measured with phenotypic drug-resistance tests. However, the output of these tests, the resistance factor (RF), requires interpretation with respect to the in vivo activity of the tested variant. Specifically, the dynamic range of the RF for each drug has to be divided into a suitable number of clinically meaningful intervals. Methods: We calculated a susceptible-to-intermediate and an intermediate-to-resistant cutoff per drug for RFs predicted by geno2pheno[resistance]. Probability densities for therapeutic success and failure were estimated from 10,444 treatment episodes. The density estimation procedure corrects for the activity of the backbone drug compounds and for therapy failure without drug resistance. For estimating the probability of therapeutic success given an RF, we fit a sigmoid function. The cutoffs are given by the roots of the third derivative of the sigmoid function. Results: For performance assessment, we used geno2pheno[resistance] RF predictions and the cutoffs for predicting therapeutic success in 2 independent sets of therapy episodes. HIVdb was used for performance comparison. On one test set (n = 807), our cutoffs and HIVdb performed equally well receiver operating characteristic curve [(ROC)–area under the curve (AUC): 0.68]. On the other test set (n = 917), our cutoffs (ROC–AUC: 0.63) and HIVdb (ROC–AUC: 0.65) performed comparatively well. Conclusions: Our method can be used for calculating clinically relevant cutoffs for (predicted) RFs. The method corrects for the activity of the backbone drug compounds and for therapy failure without drug resistance. Our method's performance is comparable with that of HIVdb. RF cutoffs for the latest version of geno2pheno[resistance] have been estimated with this method. PMID:27787339

  10. Chute cutoff as a morphological response to stream reconstruction: The possible role of backwater

    NASA Astrophysics Data System (ADS)

    Eekhout, J. P. C.; Hoitink, A. J. F.

    2015-05-01

    Stream restoration efforts often aim at creating new unconstrained meandering channels without weirs and bank revetments. In reconstructed streams, the initial morphological response of the new streams is often rapid, until a dynamic equilibrium is reached. Here we report on a chute cutoff that occurred within 3 months after realization of a stream restoration project, caused by a plug bar that formed in response to a backwater effect. The temporal evolution of the morphology of both the new and the old channels was monitored over a period of nearly 8 months, including precutoff conditions. The observations can be separated into three stages. Stage 1 is the initial period leading to cutoff vulnerability, stage 2 is the actual cutoff, and stage 3 is the morphological adjustment in response to the cutoff. In stage 1, a plug bar was deposited in one of the channel bends. Hydrodynamic model results show the location of the plug bar coincides with a region where bed shear stress decreased in downstream direction due to backwater. Longitudinal channel bed profiles show that the channel slope decreased soon after channel reconstruction. Hence, sediment from upstream was available to form the plug bar. After the plug bar was deposited, an embayment formed in the floodplain at a location where the former channel was located (stage 2). The former channel was filled with sediment prior to channel construction. It is likely that the sediment at this location was less consolidated, and therefore, prone to erosion. The chute channel continued to incise and widen into the floodplain and, after 6 months, acted as the main channel, conveying the discharge during the majority of time (stage 3). The cutoff channel gradually continued to fill with sediment, from the moment the plug bar formed until the chute channel incised into the floodplain. Sedimentary successions of the deposited material show upward fining, which is in agreement with observations of chute cutoffs in rivers

  11. Information-theoretic natural ultraviolet cutoff for spacetime.

    PubMed

    Kempf, Achim

    2009-12-04

    Fields in spacetime could be simultaneously discrete and continuous, in the same way that information can. It has been shown that the amplitudes phi(x(n)) that a field takes at a generic discrete set of points x(n) can be sufficient to reconstruct the field phi(x) for all x, namely, if there exists a certain type of natural ultraviolet (UV) cutoff in nature, and if the average spacing of the sample points is at the UV-cutoff scale. Here, we generalize this information-theoretic framework to spacetimes themselves. We show that samples taken at a generic discrete set of points of a Euclidean-signature spacetime can allow one to reconstruct the shape of that spacetime everywhere, down to the cutoff scale. The resulting methods could be useful in various approaches to quantum gravity.

  12. Treatment of amitriptyline intoxications by extended high cut-off dialysis.

    PubMed

    Schmidt, Julius J; Bertram, Anna; Kühn-Velten, W Nikolaus; Suhling, Hendrik; Wiesner, Olaf; Schneider, Andrea; Kielstein, Jan T

    2015-12-01

    Antidepressants, especially amitriptyline, are among the most frequent drug classes involved in intoxications. Despite its small molecular weight, amitriptyline is not considered to be eliminated by extracorporeal treatment methods due to its high protein binding and large volume of distribution. New high cut-off dialysers have so far not been used for removal of amitriptyline. We report two cases of amitriptyline poisoning in which we measured the amitriptyline elimination using extended high cut-off (HCO) dialysis. Despite dialyser clearances of 33 and 58 mL/min, resulting in the reduction of initial serum concentrations by ∼30%, only 211 and 920 µg of amitryptilin, respectively, (<3% of the ingested amount) could be recovered in the total collected dialysate. Hence, due to the high volume of distribution of amitriptyline, even HCO dialysis does not contribute substantially to the extracorporeal removal of amitryptilin.

  13. Treatment of amitriptyline intoxications by extended high cut-off dialysis

    PubMed Central

    Schmidt, Julius J.; Bertram, Anna; Kühn-Velten, W. Nikolaus; Suhling, Hendrik; Wiesner, Olaf; Schneider, Andrea; Kielstein, Jan T.

    2015-01-01

    Antidepressants, especially amitriptyline, are among the most frequent drug classes involved in intoxications. Despite its small molecular weight, amitriptyline is not considered to be eliminated by extracorporeal treatment methods due to its high protein binding and large volume of distribution. New high cut-off dialysers have so far not been used for removal of amitriptyline. We report two cases of amitriptyline poisoning in which we measured the amitriptyline elimination using extended high cut-off (HCO) dialysis. Despite dialyser clearances of 33 and 58 mL/min, resulting in the reduction of initial serum concentrations by ∼30%, only 211 and 920 µg of amitryptilin, respectively, (<3% of the ingested amount) could be recovered in the total collected dialysate. Hence, due to the high volume of distribution of amitriptyline, even HCO dialysis does not contribute substantially to the extracorporeal removal of amitryptilin. PMID:26613042

  14. Cut-off proposal for the detection of ketamine in hair.

    PubMed

    Salomone, A; Gerace, E; Diana, P; Romeo, M; Malvaso, V; Di Corcia, D; Vincenti, M

    2015-03-01

    Ketamine is a powerful anesthetic drug used in both human and veterinary surgery, but it is also commonly misused because of its psychotropic properties. Since the abuse of this drug has been reported in many countries worldwide, its determination in hair samples is offered as a specialist test by hundreds of laboratories. However, unlike other common drugs of abuse, a cut-off level for ketamine in hair has not been fixed yet. Therefore, aim of this study is to propose a concentration value for ketamine in hair analysis, in order to discriminate between chronic and occasional use, and between active use and external contamination. After considering the chemical properties of this molecule, and the experimental data collected in our laboratory or reported in several other published studies, we propose a cut-off level of 0.5ng/mg, as indicative of repeated exposure to ketamine. Additionally, we suggest that the detection of the metabolite norketamine should be mandatory to prove active intake and exclude false positive result from external contamination. Thus, a reasonable cut-off value for norketamine could be fixed at 0.1ng/mg, while the minimal concentration ratio norketamine/ketamine may be positively established at 0.05.

  15. 6. VIEW OF CONSTRUCTION PLANT AND EXCAVATION FOR CUTOFF TRENCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF CONSTRUCTION PLANT AND EXCAVATION FOR CUTOFF TRENCH FROM EAST SIDE OF APRON EXCAVATION, FACING WEST. October 1926 - Cushman No. 1 Hydroelectric Power Plant, Spillway, North Fork of Skokomish River, 5 miles West of Hood Canal, Hoodsport, Mason County, WA

  16. Re-evaluation of cosmic ray cutoff terminology

    NASA Technical Reports Server (NTRS)

    Cooke, D. J.; Humble, J. E.; Shea, M. A.; Smart, D. F.; Lund, N.; Rasmussen, I. L.; Byrnak, B.; Goret, P.; Petrou, N.

    1985-01-01

    The study of cosmic ray access to locations inside the geomagnetic field has evolved in a manner that has led to some misunderstanding and misapplication of the terminology originally developed to describe particle access. This paper presents what is believed to be a useful set of definitions for cosmic ray cutoff terminology for use in theoretical and experimental cosmic ray studies.

  17. Suburban Legend: School Cutoff Dates and the Timing of Births

    ERIC Educational Resources Information Center

    Dickert-Conlin, Stacy; Elder, Todd

    2010-01-01

    Many states require children to reach age 5 by a specified date in the calendar year in order to begin kindergarten. We use birth certificate records from 1999 to 2004 to assess whether parents systematically time childbirth before these eligibility cutoff dates to capture the option value of sending their child to school at a relatively young…

  18. Scaling limit of quantum electrodynamics with spatial cutoffs

    SciTech Connect

    Takaesu, Toshimitsu

    2011-02-15

    In this paper, the Hamiltonian of quantum electrodynamics with spatial cutoffs is investigated. A scaled total Hamiltonian is introduced and its asymptotic behavior is investigated. In the main theorem, it is shown that the scaled total Hamiltonian converges to a self-adjoint operator in the strong resolvent sense, and the effective potential of the Dirac field is derived.

  19. Modes and cutoff frequencies of crossed rectangular waveguides

    NASA Technical Reports Server (NTRS)

    Tham, Q. C.

    1977-01-01

    One complete solution is presented for determining the electromagnetic field of a generalized crossed rectangular waveguide. The method adopted is that of partial regions. Cutoff frequencies of symmetrical crossed waveguides are presented as an example. The results, even for low-order approximations, correspond well with the only experimental results available in the literature.

  20. 2. VIEW OF SWITCHBACKS IN FORESTA ROAD (OLD DAVIS CUTOFF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF SWITCHBACKS IN FORESTA ROAD (OLD DAVIS CUT-OFF ROAD). NOTE FORESTA ROAD BRIDGE IN LOWER LEFT. ROAD CURVE HIDDEN IN TREES AT CENTER. NOTE ROAD CUT AT LEFT. LOOKING SSW. GIS: N-37"40'47.4"/W-119"47'22.2 - Foresta Road, Yosemite Village, Mariposa County, CA

  1. Galactomannan Assay and Invasive Pulmonary Aspergillosis - Comparison of the Test Performance at an in-house and the Kit Cut-off

    PubMed Central

    Menon, Nikhilesh Ravikumar; Sudharma, Arun Ramachandran; Jairaj, Vinutha; Mathew, Joshila

    2016-01-01

    Introduction Invasive Pulmonary Aspergillosis (IPA) is an important opportunistic infection with a high degree of mortality and morbidity. Galactomannan assay (GM assay) is found to be useful for diagnosis of IPA in patients with neutropenia. However the utility of this assay has not been evaluated in a mixed patient population with other co-morbid conditions. Though a kit cut-off of 0.5 has been recommended for the diagnosis of IPA, studies have reported a higher sensitivity with cut-offs more than 0.5. Aim To establish an in-house cut-off and compare its utility with the kit cut-off to diagnose and categorize IPA as proven, probable and possible in patients with varied underlying risk factors. Materials and Methods This observational study was done in St John’s Medical College, Bangalore, Karnataka, India from January 2013-December 2014. GM assay was performed on 25 each of healthy controls and clinically diagnosed cases of IPA. The in-house cut-off was calculated by plotting the Receiver Operating Characteristic Curve (ROC). Results The in-house cut-off was calculated to be 0.52. Using this and the kit cut-off (0.5), the Sensitivity, Specificity, Positive Predictive Value (PPV) and the Negative Predictive Value (NPV) were found to be 75%, 79%, 76%, 82% and 79%, 71%, 77%, 82% respectively. Diabetes mellitus was found to be associated with more than 50% of the patients. Conclusion The established in house cut-off using healthy controls and patients with clinical diagnosis of IPA was not significantly different from that of the kit cut-off. Using either of these cut-offs, we could re-categorize two of the possible IPA cases in the probable group. This study helped to understand the clinical utility of this assay even in a mixed patient population with multiple co-morbidities. PMID:27656435

  2. Determination of hair ketamine cut-off value from Hong Kong ketamine users by LC-MS/MS analysis.

    PubMed

    Leung, K Wing; Wong, Zack C F; Ho, Janet Y M; Yip, Ada W S; Ng, Jenny S C; Ip, Stanley P H; Ng, Winki Y Y; Ho, Karen K L; Duan, Ran; Zhu, Kevin Y; Tsim, Karl W K

    2016-02-01

    Ketamine is one of the most frequent abused drugs in Hong Kong and South-East Asia, and the cases of ketamine abused have been reported worldwide. Hair has been commonly used as a specimen for the proof of chronic drug abused because of its non-invasiveness and long detection windows. The determinations of ketamine in hair with varieties of state-of-the-art instruments and detection methods have been developed in the past decade; however, the cut-off value for ketamine abuser has not been developed according to the international guidelines. The aim of this study is to propose a cut-off value for ketamine in hair by analyzing ketamine and its metabolite norketamine by LC-MS/MS method in a population of ketamine users in Hong Kong. The limit of detection (LOD) and limit of quantification (LOQ) for ketamine and norketamine were 20pg/mg and 100pg/mg, respectively. From 977 ketamine abusers, the cut-off value for ketamine in hair was proposed to be 400pg/mg of hair. This proposed cut-off value is the concentration of hair ketamine when over 90% of samples are being detected with the presence of norketamine, which is a proof of ketamine abuse. This value could be applied as a screening or occupational cut-off for reference.

  3. Agreement between two cutoff points for physical activity and associated factors in young individuals☆

    PubMed Central

    Coledam, Diogo Henrique Constantino; Ferraiol, Philippe Fanelli; Pires, Raymundo; Ribeiro, Edinéia Aparecida Gomes; Ferreira, Marco Antonio Cabral; de Oliveira, Arli Ramos

    2014-01-01

    Objective: To analyze the agreement between two cutoff points for physical activity (300 and 420 minutes/week) and associated factors in youth. Methods: The study enrolled 738 adolescents of Londrina city, Paraná, Southern Brazil. The following variables were collected by a self report questionnaire: presence of moderate to vigorous physical activity, gender, age, father and mother education level, with whom the adolescent lives, number of siblings, physical activity perception, participation in Physical Education classes, facilities available to physical activity practice and sedentary behavior. Prevalence of physical activity between criterions were compared using McNemar test and the agreement was analysed by Kappa index. Multivariate analysis was performed using Poisson regression with robust variance adjustment was applied. Results: The prevalence for physical activity was significantly different: 22,3% for 300 minutes/week and 12,8% for 420 minutes/week (p<0,05), but the agreement was strong (k=0,82, p<0,001). The variables gender, father education, physical activity perception and sedentary behavior were associated to physical activity in both analyzed criteria. Participation in Physical Education class and facilities available to physical activity practice were associated to physical activity only with 300 minutes/week cutoff point. Conclusion: Caution is suggested regarding cutoffs use for physical activity in epidemiological studies, considering they can result in differences in prevalence of physical activity and its associated factors. PMID:25479852

  4. Cut-off point for WHOQOL-bref as a measure of quality of life of older adults.

    PubMed

    Silva, Patrícia Aparecida Barbosa; Soares, Sônia Maria; Santos, Joseph Fabiano Guimarães; Silva, Líliam Barbosa

    2014-06-01

    OBJECTIVE To propose a cut-off for the World Health Organization Quality of Life-Bref (WHOQOL-bref) as a predictor of quality of life in older adults.METHODS Cross-sectional study with 391 older adults registered in the Northwest Health District in Belo Horizonte, MG, Southeastern Brazil, between October 8, 2010 and May 23, 2011. The older adults' quality of life was measured using the WHOQOL-bref. The analysis was rationalized by outlining two extreme and simultaneous groups according to perceived quality of life and satisfaction with health (quality of life good/satisfactory - good or very good self-reported quality of life and being satisfied or very satisfied with health - G5; and poor/very poor quality of life - poor or very poor self-reported quality of life and feeling dissatisfied or very dissatisfied with health - G6). A Receiver-Operating Characteristic curve (ROC) was created to assess the diagnostic ability of different cut-off points of the WHOQOL-bref.RESULTS ROC curve analysis indicated a critical value 60 as the optimal cut-off point for assessing perceived quality of life and satisfaction with health. The area under the curve was 0.758, with a sensitivity of 76.8% and specificity of 63.8% for a cut-off of ≥ 60 for overall quality of life (G5) and sensitivity 95.0% and specificity of 54.4% for a cut-off of < 60 for overall quality of life (G6).CONCLUSIONS Diagnostic interpretation of the ROC curve revealed that cut-off < 60 for overall quality of life obtained excellent sensitivity and negative predictive value for tracking older adults with probable worse quality of life and dissatisfied with health.

  5. Cut-off point for WHOQOL-bref as a measure of quality of life of older adults

    PubMed Central

    Silva, Patrícia Aparecida Barbosa; Soares, Sônia Maria; Santos, Joseph Fabiano Guimarães; Silva, Líliam Barbosa

    2014-01-01

    OBJECTIVE To propose a cut-off for the World Health Organization Quality of Life-Bref (WHOQOL-bref) as a predictor of quality of life in older adults. METHODS Cross-sectional study with 391 older adults registered in the Northwest Health District in Belo Horizonte, MG, Southeastern Brazil, between October 8, 2010 and May 23, 2011. The older adults’ quality of life was measured using the WHOQOL-bref. The analysis was rationalized by outlining two extreme and simultaneous groups according to perceived quality of life and satisfaction with health (quality of life good/satisfactory – good or very good self-reported quality of life and being satisfied or very satisfied with health – G5; and poor/very poor quality of life – poor or very poor self-reported quality of life and feeling dissatisfied or very dissatisfied with health – G6). A Receiver-Operating Characteristic curve (ROC) was created to assess the diagnostic ability of different cut-off points of the WHOQOL-bref. RESULTS ROC curve analysis indicated a critical value 60 as the optimal cut-off point for assessing perceived quality of life and satisfaction with health. The area under the curve was 0.758, with a sensitivity of 76.8% and specificity of 63.8% for a cut-off of ≥ 60 for overall quality of life (G5) and sensitivity 95.0% and specificity of 54.4% for a cut-off of < 60 for overall quality of life (G6). CONCLUSIONS Diagnostic interpretation of the ROC curve revealed that cut-off < 60 for overall quality of life obtained excellent sensitivity and negative predictive value for tracking older adults with probable worse quality of life and dissatisfied with health. PMID:25119934

  6. Environmental sampling: Issues for the cut-off regime

    SciTech Connect

    Fearey, B.L.

    1995-09-01

    The fissile material cut-off treaty (FMCT) initiative under the Conference on Disarmament mandate is envisioned to include certain aspects of environmental sampling and monitoring. One of the intents of this treaty is to bring certain non-NPT signatories (e.g., threshold states) under this treaty agreement along with the nuclear weapon states (NWSs). This paper provides a brief overview of some of the relevant issues that may be involved in the implementation and use of environmental monitoring for (1) verification of the cut-off regime declarations, (2) the detection of undeclared activities, and, (3) application in non-routine inspections. The intent is to provide backstopping information important for treaty negotiators. Specific issues addressed within this paper include signature sampling, differences in the proposed detection regime, potential signature integrators, specific examples and spoofing concerns. Many of these issues must be carefully considered and weighed in order to create a credibly verifiable inspection regime. Importantly, the cut-off treaty must enable nondiscriminatory implementation, while carefully assuring that nonproliferation treaty requirements are maintained (i.e., preventing unintentional release of critical weapons design information--potentially through environmental sampling and analysis).

  7. Computational characterization of cutoff probe system for the measurement of electron density

    SciTech Connect

    Na, Byung-Keun; Kim, Dae-Woong; Kwon, Jun-Hyuk; Chang, Hong-Young; Kim, Jung-Hyung; You, Shin-Jae

    2012-05-15

    The wave cutoff probe, a precise measurement method for measuring the electron density, was recently proposed. To characterize the cutoff probe system, in this paper, the microwave simulations of a cutoff probe system were performed at various configurations of the cutoff probe system. The influence of the cutoff probe spectrum stemming from numerous parametric elements such as the probe tip length, probe tip distance, probe tip plane orientation, chamber volume/geometry, and coaxial cable length is presented and discussed. This article is expected to provide qualitative and quantitative insight into cutoff probe systems and its optimization process.

  8. Meander cutoffs nonlocally accelerate upstream and downstream migration and channel widening

    NASA Astrophysics Data System (ADS)

    Schwenk, Jon; Foufoula-Georgiou, Efi

    2016-12-01

    The hydrologic and sediment dynamics within and near cutoffs have long been studied, establishing them as effective agents of rapid local geomorphic change. However, the morphodynamic impact of individual cutoffs at the reachwide scale remains unknown, mainly due to insufficient observations of channel adjustments over large areal extents and at high temporal frequency. Here we show via annually resolved, Landsat-derived channel masks of the dynamic meandering Ucayali River in Peru that cutoffs act as perturbations that nonlocally accelerate river migration and drive channel widening both upstream and downstream of the cutoff locations. By tracking planform changes of individual meander bends near cutoffs, we find that the downstream distance of cutoff influence scales linearly with the length of the removed reach. The discovery of nonlocal cutoff influence supports the hypothesis of "avalanche"-type behavior in meander cutoff dynamics and presents new challenges in modeling and prediction of rivers' self-adjusting responses to perturbations.

  9. Magnetospheric effects of cosmic rays. 1. Long-term changes in the geomagnetic cutoff rigidities for the stations of the global network of neutron monitors

    NASA Astrophysics Data System (ADS)

    Gvozdevskii, B. B.; Abunin, A. A.; Kobelev, P. G.; Gushchina, R. T.; Belov, A. V.; Eroshenko, E. A.; Yanke, V. G.

    2016-07-01

    Vertical geomagnetic cutoff rigidities are obtained for the stations of the global network of neutron monitors via trajectory calculations for each year of the period from 1950 to 2020. Geomagnetic cutoff rigidities are found from the model of the Earth's main field International Geomagnetic Reference Field (IGRF) for 1950-2015, and the forecast until 2020 is provided. In addition, the geomagnetic cutoff rigidities for the same period are obtained by Tsyganenko model T89 (Tsyganenko, 1989) with the average annual values of the Kp-index. In each case, the penumbra is taken into account in the approximation of the flat and power spectra of variations of cosmic rays. The calculation results show an overall decrease in geomagnetic cutoff rigidities, which is associated with the overall decrease and restructuring of the geomagnetic field during the reporting period, at almost all points.

  10. Energetics of southeastern Pacific cut-off lows

    NASA Astrophysics Data System (ADS)

    Gan, Manoel Alonso; Piva, Everson Dal

    2016-06-01

    The existence of cut-off lows (COLs) over South Pacific and South America is often associated with adverse weather events such as intense precipitation over the central region of South America, frost episodes in southern Brazil and the development of Andes lee cyclones and intense cyclones over the southern coast of Brazil. Despite this importance, the formation and maintenance mechanisms of the COLs are not well understood. To detail the significant variability in terms of the eddy kinetic energy equation for fifty cases of COLs that formed over the southeastern Pacific Ocean is the aim of this study. Only the cases of COLs that formed over the ocean and remained there during most of their life were chosen. The main terms of the equation [ageostrophic flux convergence (AFC), baroclinic conversion (BRC) and barotropic conversion (BRT)] were calculated using the 6-hourly gridded data from the National Centers for Environmental Prediction/Department of Energy reanalysis. The formation mechanism of the COLs was associated with BRC and AFC. During the midlife period, the BRC term converted eddy kinetic energy to eddy potential energy and the AFC had a positive contribution until 6 h after the midlife point. In the dissipation phase, the BRC term remained positive and AFC became negative. The BRT extracted kinetic energy from the COL during the entire life cycle. The AFC term was the most important in all phases of the cut-off lifetime, and it was the responsible for extending the cut-off lifetime while the others terms were negatives.

  11. Corotation torques in the solar nebula - The cutoff function

    NASA Technical Reports Server (NTRS)

    Ward, William R.

    1989-01-01

    The behavior of high-order corotation resonances in a disk of finite thickness is examined. The torque exerted at an mth-order resonance is determined by employing a vertically averaged disturbing function, and the ratio of this torque to that exerted on a cold, two-dimensional disk is identified as the so-called torque cutoff function. This function is then used to calculate contributions from the corotation torques to eccentricity variations of a perturber's orbit assumed orbiting in the disk.

  12. 49 CFR 40.95 - What are the adulterant cutoff concentrations for initial and confirmation tests?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false What are the adulterant cutoff concentrations for... Laboratories § 40.95 What are the adulterant cutoff concentrations for initial and confirmation tests? (a) As a laboratory, you must use the cutoff concentrations for the initial and confirmation adulterant testing...

  13. 49 CFR 40.95 - What are the adulterant cutoff concentrations for initial and confirmation tests?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false What are the adulterant cutoff concentrations for... Laboratories § 40.95 What are the adulterant cutoff concentrations for initial and confirmation tests? (a) As a laboratory, you must use the cutoff concentrations for the initial and confirmation adulterant testing...

  14. 49 CFR 40.95 - What are the adulterant cutoff concentrations for initial and confirmation tests?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false What are the adulterant cutoff concentrations for... Laboratories § 40.95 What are the adulterant cutoff concentrations for initial and confirmation tests? (a) As a laboratory, you must use the cutoff concentrations for the initial and confirmation adulterant testing...

  15. 49 CFR 40.95 - What are the adulterant cutoff concentrations for initial and confirmation tests?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false What are the adulterant cutoff concentrations for... Laboratories § 40.95 What are the adulterant cutoff concentrations for initial and confirmation tests? (a) As a laboratory, you must use the cutoff concentrations for the initial and confirmation adulterant testing...

  16. 49 CFR 40.95 - What are the adulterant cutoff concentrations for initial and confirmation tests?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false What are the adulterant cutoff concentrations for... Laboratories § 40.95 What are the adulterant cutoff concentrations for initial and confirmation tests? (a) As a laboratory, you must use the cutoff concentrations for the initial and confirmation adulterant testing...

  17. 10 CFR 26.133 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Cutoff levels for drugs and drug metabolites. 26.133... § 26.133 Cutoff levels for drugs and drug metabolites. Subject to the provisions of § 26.31(d)(3)(iii), licensees and other entities may specify more stringent cutoff levels for drugs and drug metabolites...

  18. 10 CFR 26.133 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Cutoff levels for drugs and drug metabolites. 26.133... § 26.133 Cutoff levels for drugs and drug metabolites. Subject to the provisions of § 26.31(d)(3)(iii), licensees and other entities may specify more stringent cutoff levels for drugs and drug metabolites...

  19. 10 CFR 26.133 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Cutoff levels for drugs and drug metabolites. 26.133... § 26.133 Cutoff levels for drugs and drug metabolites. Subject to the provisions of § 26.31(d)(3)(iii), licensees and other entities may specify more stringent cutoff levels for drugs and drug metabolites...

  20. 10 CFR 26.163 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Cutoff levels for drugs and drug metabolites. 26.163... the Department of Health and Human Services § 26.163 Cutoff levels for drugs and drug metabolites. (a) Initial drug testing. (1) HHS-certified laboratories shall apply the following cutoff levels for...

  1. 10 CFR 26.133 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Cutoff levels for drugs and drug metabolites. 26.133... § 26.133 Cutoff levels for drugs and drug metabolites. Subject to the provisions of § 26.31(d)(3)(iii), licensees and other entities may specify more stringent cutoff levels for drugs and drug metabolites...

  2. 10 CFR 26.163 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Cutoff levels for drugs and drug metabolites. 26.163... the Department of Health and Human Services § 26.163 Cutoff levels for drugs and drug metabolites. (a) Initial drug testing. (1) HHS-certified laboratories shall apply the following cutoff levels for...

  3. 10 CFR 26.133 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Cutoff levels for drugs and drug metabolites. 26.133... § 26.133 Cutoff levels for drugs and drug metabolites. Subject to the provisions of § 26.31(d)(3)(iii), licensees and other entities may specify more stringent cutoff levels for drugs and drug metabolites...

  4. 10 CFR 26.163 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Cutoff levels for drugs and drug metabolites. 26.163... the Department of Health and Human Services § 26.163 Cutoff levels for drugs and drug metabolites. (a) Initial drug testing. (1) HHS-certified laboratories shall apply the following cutoff levels for...

  5. 10 CFR 26.163 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Cutoff levels for drugs and drug metabolites. 26.163... the Department of Health and Human Services § 26.163 Cutoff levels for drugs and drug metabolites. (a) Initial drug testing. (1) HHS-certified laboratories shall apply the following cutoff levels for...

  6. 10 CFR 26.163 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Cutoff levels for drugs and drug metabolites. 26.163... the Department of Health and Human Services § 26.163 Cutoff levels for drugs and drug metabolites. (a) Initial drug testing. (1) HHS-certified laboratories shall apply the following cutoff levels for...

  7. 76 FR 33161 - Installation and Use of Engine Cut-off Switches on Recreational Vessels

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... SECURITY Coast Guard 33 CFR Parts 175 and 183 RIN 1625-AB34 Installation and Use of Engine Cut-off Switches... on whether it should require engine cut-off switches as a standard safety feature on propulsion... whether it should require operators of these recreational vessels to use engine cut-off switches....

  8. High Operating Temperature Barrier Infrared Detector with Tailorable Cutoff Wavelength

    NASA Technical Reports Server (NTRS)

    Ting, David Z. (Inventor); Hill, Cory J. (Inventor); Seibel, Alexander (Inventor); Bandara, Sumith Y. (Inventor); Gunapala, Sarath D. (Inventor)

    2015-01-01

    A barrier infrared detector with absorber materials having selectable cutoff wavelengths and its method of manufacture is described. A GaInAsSb absorber layer may be grown on a GaSb substrate layer formed by mixing GaSb and InAsSb by an absorber mixing ratio. A GaAlAsSb barrier layer may then be grown on the barrier layer formed by mixing GaSb and AlSbAs by a barrier mixing ratio. The absorber mixing ratio may be selected to adjust a band gap of the absorber layer and thereby determine a cutoff wavelength for the barrier infrared detector. The absorber mixing ratio may vary along an absorber layer growth direction. Various contact layer architectures may be used. In addition, a top contact layer may be isolated into an array of elements electrically isolated as individual functional detectors that may be used in a detector array, imaging array, or focal plane array.

  9. Permeability porosity relationships (K, Phi cut-off)

    SciTech Connect

    Djettou, F.; Reda, H.

    1995-08-01

    Several reservoirs of Lower Devonian in Ghadames basin present porosities greater than 10 Pu, but during the test they are rather impermeable. It seems that this phenomena extends to BERKINE and Rhourd Messaoud areas. This seriously affect the estimation of recovery reserves. The best we can do is to study and try to understand reservoir problems. The method we choose is based on statistical analysis of test results and their comparison with core and log measurements. It concerns mainly cummulative curves of productive and non-productive tests (dry test). This involves about 20 wells where are can define: Siegenian with: Fine grained in BBK and ROM Coarse grained toward BRN - Emsian is rather homogeneous in the region. The sand cut-off porosity is greater than 11 Pu. However the reservoir can`t produce itself then we can not take account in reserve estimation. In conclusion, a sandy reservoir of Lower Devonian in Ghadames basin may be very porous (11-12%) and impermeable while in the other cases reservoirs can produce with porosity of 7 or 8 Po. However a HC definition based on cut-off porosity in Ghadames basin should be done before net pay an recovery reserves estimation.

  10. Cutoff for extensions of massive gravity and bi-gravity

    NASA Astrophysics Data System (ADS)

    Matas, Andrew

    2016-04-01

    Recently there has been interest in extending ghost-free massive gravity, bi-gravity, and multi-gravity by including non-standard kinetic terms and matter couplings. We first review recent proposals for this class of extensions, emphasizing how modifications of the kinetic and potential structure of the graviton and modifications of the coupling to matter are related. We then generalize existing no-go arguments in the metric language to the vielbein language in second-order form. We give an ADM argument to show that the most promising extensions to the kinetic term and matter coupling contain a Boulware-Deser ghost. However, as recently emphasized, we may still be able to view these extensions as effective field theories below some cutoff scale. To address this possibility, we show that there is a decoupling limit where a ghost appears for a wide class of matter couplings and kinetic terms. In particular, we show that there is a decoupling limit where the linear effective vielbein matter coupling contains a ghost. Using the insight we gain from this decoupling limit analysis, we place an upper bound on the cutoff for the linear effective vielbein coupling. This result can be generalized to new kinetic interactions in the vielbein language in second-order form. Combined with recent results, this provides a strong uniqueness argument on the form of ghost-free massive gravity, bi-gravity, and multi-gravity.

  11. Establishing Genotypic Cutoff Values To Measure Antimicrobial Resistance in Salmonella.

    PubMed

    Tyson, Gregory H; Zhao, Shaohua; Li, Cong; Ayers, Sherry; Sabo, Jonathan L; Lam, Claudia; Miller, Ron A; McDermott, Patrick F

    2017-03-01

    Whole-genome sequencing (WGS) has transformed our understanding of antimicrobial resistance, helping us to better identify and track the genetic mechanisms underlying phenotypic resistance. Previous studies have demonstrated high correlations between phenotypic resistance and the presence of known resistance determinants. However, there has never been a large-scale assessment of how well resistance genotypes correspond to specific MICs. We performed antimicrobial susceptibility testing and WGS of 1,738 nontyphoidal Salmonella strains to correlate over 20,000 MICs with resistance determinants. Using these data, we established what we term genotypic cutoff values (GCVs) for 13 antimicrobials against Salmonella For the drugs we tested, we define a GCV as the highest MIC of isolates in a population devoid of known acquired resistance mechanisms. This definition of GCV is distinct from epidemiological cutoff values (ECVs or ECOFFs), which currently differentiate wild-type from non-wild-type strains based on MIC distributions alone without regard to genetic information. Due to the large number of isolates involved, we observed distinct MIC distributions for isolates with different resistance gene alleles, including for ciprofloxacin and tetracycline, suggesting the potential to predict MICs based on WGS data alone.

  12. A HARD X-RAY POWER-LAW SPECTRAL CUTOFF IN CENTAURUS X-4

    SciTech Connect

    Chakrabarty, Deepto; Nowak, Michael A.; Tomsick, John A.; Boggs, Steven E.; Craig, William W.; Grefenstette, Brian W.; Fürst, Felix; Harrison, Fiona A.; Rana, Vikram; Psaltis, Dimitrios; Bachetti, Matteo; Barret, Didier; Christensen, Finn E.; Hailey, Charles J.; Kaspi, Victoria M.; Miller, Jon M.; Stern, Daniel; Wik, Daniel R.; Zhang, William W.; Wilms, Jörn

    2014-12-20

    The low-mass X-ray binary (LMXB) Cen X-4 is the brightest and closest (<1.2 kpc) quiescent neutron star transient. Previous 0.5-10 keV X-ray observations of Cen X-4 in quiescence identified two spectral components: soft thermal emission from the neutron star atmosphere and a hard power-law tail of unknown origin. We report here on a simultaneous observation of Cen X-4 with NuSTAR (3-79 keV) and XMM-Newton (0.3-10 keV) in 2013 January, providing the first sensitive hard X-ray spectrum of a quiescent neutron star transient. The 0.3-79 keV luminosity was 1.1×10{sup 33} D{sub kpc}{sup 2} erg s{sup –1}, with ≅60% in the thermal component. We clearly detect a cutoff of the hard spectral tail above 10 keV, the first time such a feature has been detected in this source class. We show that thermal Comptonization and synchrotron shock origins for the hard X-ray emission are ruled out on physical grounds. However, the hard X-ray spectrum is well fit by a thermal bremsstrahlung model with kT{sub e} = 18 keV, which can be understood as arising either in a hot layer above the neutron star atmosphere or in a radiatively inefficient accretion flow. The power-law cutoff energy may be set by the degree of Compton cooling of the bremsstrahlung electrons by thermal seed photons from the neutron star surface. Lower thermal luminosities should lead to higher (possibly undetectable) cutoff energies. We compare Cen X-4's behavior with PSR J1023+0038, IGR J18245–2452, and XSS J12270–4859, which have shown transitions between LMXB and radio pulsar modes at a similar X-ray luminosity.

  13. On the Phase-Averaged Spectrum of Pulsars and Shape of Their Cutoffs

    NASA Technical Reports Server (NTRS)

    Celik, O.; Thomas, T. J.

    2010-01-01

    All gamma ray pulsars exhibit an exponential cutoff in their spectra and for bright pulsars the statistics are sufficiently high to study the detailed shape of the cutoff. The phase averaged spectra of some pulsars exhibit a sub-exponential cutoff, not predicted by any single physical mechanism. Further studies clarified that (his gentler average cutoff is a consequence of having significant variations of the cutoff energy in the phase-resolved spectrum. In conclusion, the phase-averaged spectrum of a pulsar is not a physical quantity to test high-energy emission models.

  14. Different diagnostic cut-off values of urinary fractionated metanephrines according to sex for the diagnosis of pheochromocytoma in Korean subjects.

    PubMed

    Sohn, Seo Young; Park, Hyung Doo; Lee, Soo Youn; Kim, Jung Han; Jung, Byong Chang; Kim, Hye Jeong; Jang, Hye Won; Kim, Kwang Won; Lee, Moon Kyu; Min, Yong Ki; Kim, Jae Hyeon

    2012-01-01

    The diagnosis of pheochromocytoma depends on the documentation of catecholamine overproduction. The use of urinary fractionated metanephrines has recently become common for the diagnosis of pheochromocytoma. In order to avoid false positive and false negative results, optimal cut-off levels are necessary; however, there have been few published reports on whether different cut-off levels are needed to diagnose pheochromocytoma according to sex. We reviewed the medical records of 815 subjects (including 103 pheochromocytoma patients) whose of 24-h urinary fractionated metanephrine was measured using high-performance liquid chromatography methods and adrenal imaging at Samsung Medical Center. Receiver operating characteristic (ROC) curves were used to determine cut-off values according to sex. The upper limit values of fractionated metanephrine in healthy volunteers and the control group were significantly higher in male subjects compared with females. When we applied cut-off values according to sex, the diagnostic efficacies (defining a positive test as either metanephrine or normetanephrine levels above the cut-off value) were a sensitivity of 96% in male subjects and 98.1% in female subjects and a specificity of 88.6% in male subjects and 94.1% in female subjects. However, when we applied cut-off values without considering sex, the specificity decreased from 88.6% to 77.8% in male subjects. In this study, urinary fractionated metanephrines had a high level of sensitivity and specificity for the diagnosis of pheochromocytoma. However, diagnostic cut-off values were higher in male subjects than in female subjects. Therefore, different cut-off values may be needed according to sex to diagnose pheochromocytoma in Koreans.

  15. Flow Structure and Channel Change in Chute Cutoffs On Meandering Rivers

    NASA Astrophysics Data System (ADS)

    Zinger, J. A.; Rhoads, B. L.; Best, J. L.; Johnson, K. K.

    2011-12-01

    Freely meandering rivers typically exhibit complex, continuously evolving patterns of planform geometry involving elongation of the channel path through lateral migration and shorting of this path through bend cutoffs. Despite the importance of cutoffs in shaping the planform geometry of meandering rivers, the fluvial processes operative immediately after initiation of a cutoff are poorly understood. Two recent chute cutoff events on a single bend on the Wabash River, IL-IN, have provided an unprecedented opportunity to document the morphologic evolution and flow structure of chute cutoffs in a large, unregulated, meandering river. Here, we present results of ADCP measurements of three-dimensional flow velocity and bed topography at these cutoffs and describe a conceptual model for the morphodynamics of chute cutoffs prior to oxbow lake formation. Our results indicate that the flow structure at upstream and downstream ends of cutoff channels, prior to plugging of the entrance and exit of the abandoned bend with sediment, is analogous to flow through diffluence - confluence units. The interaction of this flow structure with an erodible bed and banks can cause rapid widening of the upstream end of the cutoff channel and bar development i) in the main channel where velocities are reduced, and ii) in the separation zone of the cutoff channel. Over time, these patterns of deposition and erosion will lead formation of an oxbow lake and complete capture of the flow by the cutoff channel.

  16. Cut-off analysis of 19-cell Yb-doped double-cladding rod-type photonic crystal fibers.

    PubMed

    Poli, F; Coscelli, E; Alkeskjold, T T; Passaro, D; Cucinotta, A; Leick, L; Broeng, J; Selleri, S

    2011-05-09

    Yb-doped double-cladding large mode area rod-type photonic crystal fibers are a key component for power scaling in fiber laser systems. Recently, designs with 19-cell core defect, that is with 19 missing air-holes in the center of the photonic crystal cladding, have been proposed, with reported core diameter up to 100 μm. In this paper an analysis of the cut-off wavelength of the first high-order mode in such low-NA fibers is reported, accounting for different approaches for the definition of the cladding effective index. Results have shown that taking into account the finite fiber cross-section and considering the first cladding mode of the actual fiber is mandatory to obtain a correct estimate of the cut-off wavelength.

  17. Are there standardized cutoff values for neutrophil-lymphocyte ratios in bacteremia or sepsis?

    PubMed

    Gürol, Gölnül; Çiftci, İhsan Hakki; Terizi, Huseyin Agah; Atasoy, Ali Rıza; Ozbek, Ahmet; Köroğlu, Mehmet

    2015-04-01

    Bacteremia and sepsis are common causes of morbidity and mortality worldwide, with incorrect or delayed diagnoses being associated with increased mortality. New tests or markers that allow a more rapid and less costly detection of bacteremia and sepsis have been investigated. The aim of this study was to clarify the cutoff value of the neutrophillymphocyte ratio (NLR) according to procalcitonin (PCT) level in the decision-making processes for bacteremia and sepsis. In addition, other white blood cell subgroup parameters, which are assessed in all hospitals, for bacteremia and sepsis were explored. This retrospective study included 1,468 patients with suspected bacteremia and sepsis. Patients were grouped according to the following PCT criteria: levels <0.05 ng/ml (healthy group), 0.05-0.5 ng/ml (local infection group), 0.5-2 ng/ml (systemic infection group), 2-10 ng/ml (sepsis group), and >10 ng/ml (sepsis shock group). One important finding of this study, which will serve as a baseline to measure future progress, is the presence of many gaps in the information on pathogens that constitute a major health risk. In addition, clinical decisions are generally not coordinated, compromising the ability to assess and monitor a situation. This report represents the first study to determine the limits of the use of NLR in the diagnosis of infection or sepsis using a cutoff value of <5 when sufficient exclusion criteria are used.

  18. Establishing a clinically relevant cutoff to the Dependency Scale from the dimensional clinical personality inventory.

    PubMed

    Carvalho, Lucas de F; Pianowski, Giselle; Filho, Nelson H

    2017-02-03

    The Clinical Dimensional Personality Inventory (IDCP) is a 163-item self-report tool developed for the assessment of 12 dimensions of personality pathology. One of the scales comprising the instrument-the Dependency scale-is intended to provide psychometric information on traits closely related to the Dependent Personality Disorder (DPD). In the present study, we used both Item Response Theory modeling and Receiver Operating Characteristic curve analysis to establishing a clinically meaningful cutoff for the IDCP Dependency Scale. Participants were 2.481 adults, comprised by outpatients diagnosed with DPD, outpatients diagnosed with other PDs, and adults from the general population. The Wright's item map graphing technique revealed that outpatients were located at the very high levels in the latent scale continuum of the Dependency Scale, with a very large effect size for the mean difference between patients and non-patients. The ROC curve analysis supported a cutoff at 2.3 points in the Dependency Scale, which yielded 0.86 of sensitivity and 0.79 of specificity. Findings from the present investigation suggest the IDCP Dependency Scale is useful as a screening tool of the core features of the DPD. We address potential clinical applications for the instrument, and discuss limitations from the present study.

  19. Scope and verification of a Fissile Material (Cutoff) Treaty

    SciTech Connect

    Hippel, Frank N. von

    2014-05-09

    A Fissile Material Cutoff Treaty (FMCT) would ban the production of fissile material - in practice highly-enriched uranium and separated plutonium - for weapons. It has been supported by strong majorities in the United Nations. After it comes into force, newly produced fissile materials could only be produced under international - most likely International Atomic Energy Agency - monitoring. Many non-weapon states argue that the treaty should also place under safeguards pre-existing stocks of fissile material in civilian use or declared excess for weapons so as to make nuclear-weapons reductions irreversible. This paper discusses the scope of the FMCT, the ability to detect clandestine production and verification challenges in the nuclear-weapons states.

  20. Parallelized Stochastic Cutoff Method for Long-Range Interacting Systems

    NASA Astrophysics Data System (ADS)

    Endo, Eishin; Toga, Yuta; Sasaki, Munetaka

    2015-07-01

    We present a method of parallelizing the stochastic cutoff (SCO) method, which is a Monte-Carlo method for long-range interacting systems. After interactions are eliminated by the SCO method, we subdivide a lattice into noninteracting interpenetrating sublattices. This subdivision enables us to parallelize the Monte-Carlo calculation in the SCO method. Such subdivision is found by numerically solving the vertex coloring of a graph created by the SCO method. We use an algorithm proposed by Kuhn and Wattenhofer to solve the vertex coloring by parallel computation. This method was applied to a two-dimensional magnetic dipolar system on an L × L square lattice to examine its parallelization efficiency. The result showed that, in the case of L = 2304, the speed of computation increased about 102 times by parallel computation with 288 processors.

  1. Polypharmacy Cut-Off for Gait and Cognitive Impairments

    PubMed Central

    Pothier, Kristell; Morello, Remy; Lelong-Boulouard, Véronique; Lescure, Pascale; Bocca, Marie-Laure; Marcelli, Christian; Descatoire, Pablo; Chavoix, Chantal

    2016-01-01

    Background: Polypharmacy is a well-established risk factor for falls, and these are one of the major health problems that affect the quality of life as people age. However, the risk of mobility and cognitive impairments consecutive to polypharmacy has been little addressed, despite the association between these adverse outcomes and falls. Moreover, the rare polypharmacy cut-offs were all but one arbitrarily determined. Objective: Studying relationships between polypharmacy and both mobility and cognitive impairments, and statistically determining a cut-off point in the number of medicinal molecule beyond which polypharmacy has deleterious consequences with respect to mobility and cognitive impairment. Methods: We enrolled 113 community-dwelling adults aged 55 years and older with a fall history, with or without injury, in the previous year. We carefully collected information about daily medicinal molecules taken. We assessed basic mobility and global cognition with the Time-Up-and-Go and the Montreal Cognitive Assessment (MoCA) test, respectively (clinicaltrials.gov NCT02292316). Results: Timed-Up and Go test and MoCA scores were both significantly correlated with the number of molecule, used. Receiver Operating Characteristic curves indicate, with high prediction (p < 0.002), that daily consumption of five or more molecules is associated with risk for both impaired mobility and global cognition. These relationships were independent of the number of comorbidities and of the pharmacological class. Conclusion: Community-dwelling adults aged 55 years and older who take five or more daily medicinal molecules are at high risk for both mobility and cognitive impairments. Physicians and patients should be aware of these new findings, especially when there are multiple prescribers involved in the care of the patient. PMID:27630572

  2. Extension of cutoff in high harmonic by using doubly charged ions in a laser-ablation plume

    SciTech Connect

    Suzuki, Masayuki; Baba, Motoyoshi; Kuroda, Hiroto; Ganeev, Rashid A.; Bom, Luc Bertrand Elouga; Ozaki, Tsuneyuki

    2007-11-15

    We report high-order harmonic generation from doubly charged ions in laser-ablation plasma produced by different prepulse intensities. At the prepulse intensity of 3.5x10{sup 10} W cm{sup -2}, harmonics up to the 63rd order (12.62 nm wavelength, 98.3 eV photon energy) were obtained by using a laser-ablation titanium plume. From analysis of the harmonics and visible radiation from the laser-ablation titanium plume at different prepulse intensities, we conclude that the highest harmonics near the cutoff region originated from doubly charged titanium ions. These studies show the effectiveness of using doubly charged ions to extend the cutoff energy of high-order harmonics.

  3. Prevalence of body mass index and body weight cut-off points for in vitro fertilization treatment at U.S. clinics and current clinic weight loss strategy recommendations.

    PubMed

    Turner-McGrievy, Gabrielle M; Grant, Breănna L

    2015-09-01

    The goal of this study was to determine how many clinics providing in vitro fertilization (IVF) in the United States require a body mass index (BMI) or body weight cut-off point to determine treatment eligibility. US clinics listed as members on the Society of Assisted Reproduction website in late 2013 were contacted by phone between January and March 2014. Clinic personnel were asked if a BMI or body weight cut-off points was used to determine IVF treatment eligibility and what strategies they recommended for their patients to achieve a healthy body weight. Of the 379 clinics contacted, 347 responded (92% response rate) and 35% (n = 120) reported using a BMI or body weight cut-off points to determine eligibility for IVF treatment. Mean BMI (± SD) cut-off points was 38.4 ± 5.2 kg/m(2) and mean body weight (± SD) cut-off points was 130.2 ± 14.8 kg. Of the clinics using a set cut-off points, half (46%) provided no weight loss recommendations for patients. A sizable portion of US IVF clinics report a required or preferred BMI or body weight cut-off points for treatment. Despite this, most clinics did not provide a recommended program or approach for weight loss with very few clinics reporting an in-house program.

  4. Effect of cut-off points on performance of laser fluorescence for detecting occlusal caries.

    PubMed

    Braga, Mariana M; Mendes, Fausto M; Imparato, José Carlos P; Rodrigues, Célia R M D

    2007-01-01

    This in vitro study aimed to evaluate the influence of cut-off points on the performance of laser fluorescence (LF) in detecting occlusal caries in permanent and primary teeth. The use of different cut-off points influenced the performance of LF device in detection of occlusal caries in both kind of teeth, but the performance in permanent teeth suffered more influence from variation of cut-off points scales than in primary group.

  5. Morphodynamics of neck cutoffs on elongate meander loops, White River, Arkansas, USA

    NASA Astrophysics Data System (ADS)

    Konsoer, K. M.

    2015-12-01

    Meander cutoff and oxbow lake formation are essential components of alluvial architecture and riverine habitat of meandering river floodplains. Yet, despite their ubiquitous presence within active floodplains, the detailed processes involved in the initiation of cutoffs and oxbow lakes remain incompletely understood, primarily due to the intermittent nature of such events. Furthermore, conceptual models of meander cutoff and oxbow lake formation have been primarily developed for chute cutoffs and relatively simple planform configurations. Less attention has been given to neck cutoff dynamics occurring on highly sinuous meandering rivers with complex planform morphology. During the formation of a neck cutoff on a compound elongate loop, the upstream and downstream limbs can become oriented roughly subparallel with flow in opposite directions separated by a narrow meander neck. Immediately following cutoff of this thin neck, flow from the upstream limb is sharply redirected into the downstream limb over a short distance. These conditions of tight bend flow should become more pronounced as the ratio of radius of curvature to channel width become smaller, leading to complex patterns of three-dimensional velocities that have implications for the evolution of the cutoff channel and the transformation of the abandoned bend into an oxbow lake. This paper investigates the process dynamics of neck cutoff and oxbow lake formation using detailed field measurements of three-dimensional flow velocities, channel bed topography and geotechnical analysis of the banks and floodplains from three neck cutoffs along the White River, Arkansas (USA), each representing a different stage in the morphologic evolution from cutoff to oxbow lake. Results from this study suggests that the planform geometry of neck cutoff on an elongate meander loop can influence the spatial pattern of sediment deposition within the abandoned loop leading to increased hydrologic connectivity to the main channel

  6. Percentile curves for body fatness and cut-offs to define malnutrition in Russians

    NASA Astrophysics Data System (ADS)

    Nikolaev, D. V.; Rudnev, S. G.; Starunova, O. A.; Eryukova, T. A.; Kolesnikov, V. A.; Ponomareva, E. G.; Soboleva, N. P.; Sterlikov, S. A.

    2013-04-01

    Here, we report first results of the large-scale ongoing bioelectrical impedance body composition study in Russians. By the end of 2012, 216 out of 800 Russian Health Centres submitted raw bioimpedance data on 844,221 adults and children aged 5-80 years, representing nearly 0.6% of the Russian population, who were accessed cross-sectionally using the same type of bioimpedance meter, ABC-01 Medas. Estimates of overweight, obesity, and normal weight obesity prevalence in the general population, as well as characteristics of diagnostic sensitivity and specificity of the conventional WHO BMI-based criteria of obesity depending on age are obtained. The smoothed reference centile curves for percentage fat mass are constructed, and localized cut-offs for fatness and thinness are provided that can be used both at the individual and epidemiological levels.

  7. Flow structure and channel morphodynamics of meander bend chute cutoffs: A case study of the Wabash River, USA

    NASA Astrophysics Data System (ADS)

    Zinger, Jessica A.; Rhoads, Bruce L.; Best, James L.; Johnson, Kevin K.

    2013-12-01

    paper documents the three-dimensional structure of flow and bed morphology of two developing chute cutoffs on a single meander bend on the lower Wabash River, USA, and relates the flow structure to patterns of morphologic change in the evolving cutoff channels. The upstream end of the cutoff channels is characterized by: (1) a zone of flow velocity reduction/stagnation and bar development in the main channel across from the cutoff entrance, (2) flow separation and bar development along the inner (left) bank of the cutoff channel immediately downstream from the cutoff entrance, and (3) helical motion and outward advection of flow momentum entering the cutoff channel, leading to erosion of the outer (right) bank of the cutoff channel. At the downstream end of the cutoff channels, the major hydrodynamic and morphologic features are: (1) flow stagnation along the bank of the main channel immediately upstream of the cutoff channel mouth, (2) convergence of flows from the cutoff and main channels, (3) helical motion of flow from the cutoff, (4) a zone of reduced velocity along the bank of the main channel immediately downstream from the cutoff channel mouth, and (5) development of a prominent bar complex that penetrates into the main channel and extends from the stagnation zone upstream to downstream of the cutoff mouth. These results provide the basis for a conceptual model of chute-cutoff dynamics in which the upstream and downstream ends of a cutoff channel are treated as a bifurcation and confluence, respectively.

  8. Accuracy of cutoff probe for measuring electron density: simulation and experiment

    NASA Astrophysics Data System (ADS)

    Kim, Dae-Woong; You, Shin-Jae; Kim, Si-June; Lee, Jang-Jae; Kim, Jung-Hyung; Oh, Wang-Yuhl

    2016-09-01

    The electron density has been used for characterizing the plasma for basic research as well as industrial application. To measure the exact electron density, various type of microwave probe has been developed and improved. The cutoff probe is a promising technique inferring the electron density from the plasma resonance peak on the transmission spectrum. In this study, we present the accuracy of electron density inferred from cutoff probe. The accuracy was investigated by electromagnetic simulation and experiment. The discrepancy between the electron densities from the cutoff probe and other sophisticated microwave probes were investigated and discussed. We found that the cutoff probe has good accuracy in inferred electron density. corresponding author.

  9. Flow, Morphology and Sedimentology of an Evolving Chute Cutoff on the Wabash River, IL-in.

    NASA Astrophysics Data System (ADS)

    Zinger, J. A.; Best, J.; Rhoads, B. L.; Larson, T. H.

    2014-12-01

    The development of chute cutoffs and the resulting abandonment of meander bends have a substantial influence on the sedimentary dynamics of floodplains. The incision of a chute cutoff channel can rapidly mobilize a large volume of floodplain sediment. On the other hand, bar formation during bend abandonment and the subsequent deposition of sediment within the oxbow lake are key processes in the production of a heterogeneous floodplain sedimentary architecture. This paper describes the evolution of two recent chute cutoffs on the Wabash River, IL-IN. We follow these cutoffs from their initial incision in 2008-2009 through the early stages of bend abandonment. The volume of floodplain sediment mobilized by erosion of the two cutoff channels is estimated using channel bankline positions determined from RTK-GPS surveys and aerial orthophotographs; this flux is then assessed within the context of the sediment mobilized by lateral migration of bends. Repeat bathymetric surveys and aerial photography capture the evolution of bar forms associated with the chute cutoff, and data from ground-penetrating radar reveal the subsurface structure of the complex assemblage of bars that developed as the chute cutoff system shifted from a predominantly erosional to a mixed depositional-erosional phase. These results are combined with knowledge of chute cutoff hydrodynamics to develop an understanding of the dynamics of sediment exchange between river channels and floodplains at evolving meander bend cutoffs.

  10. Beta shapefactor determinations by the cutoff energy yield method

    NASA Astrophysics Data System (ADS)

    Grau Carles, A.

    2005-10-01

    The measurement of spectral deformations due to the forbiddenness of β transitions is commonly resolved by fitting a Kurie plot to experimental data. However, the autoabsorption of the sample and the presence of electromagnetic interferences frequently modify the expected spectral shape, making the determination of the shapefactor function inaccurate in semiconductor and magnetic spectrometers. Although the problem of autoabsorption is not present in liquid-scintillation samples, the sum-coincidence process for pulses and the poor resolution of scintillation spectrometers complicate the deconvolution of the spectra. The goal of this paper is to measure shapefactor functions by making use of observables, such as the maximum point or the cutoff energy yield, which are invariant under resolution changes. As a test of the method, the shapefactor coefficients of the six β-emitters, 36Cl, 204Tl, 210Bi, 89Sr, 90Y and 32P are determined from the analysis of the liquid-scintillation pulse-height spectra. Although the results for 210Bi, 89Sr and 90Y are in good agreement with theory, the measured shapefactors for 36Cl and 204Tl exhibit similar deviations from theory than those referenced in the literature for the Kurie plots.

  11. CSF biomarkers cutoffs: the importance of coincident neuropathological diseases

    PubMed Central

    Toledo, Jon B.; Brettschneider, Johannes; Grossman, Murray; Arnold, Steven E.; Hu, William T.; Xie, Sharon X.; Lee, Virginia M.-Y.; Shaw, Leslie M.

    2012-01-01

    The effects of applying clinical versus neuropathological diagnosis and the inclusion of cases with coincident neuropathological diagnoses have not been assessed specifically when studying cerebrospinal fluid (CSF) biomarker classification cutoffs for patients with neurodegenerative diseases that cause dementia. Thus, 142 neuropathologically diagnosed neurodegenerative dementia patients [71 Alzheimer’s disease (AD), 29 frontotemporal lobar degeneration (FTLD), 3 amyotrophic lateral sclerosis, 7 dementia with Lewy bodies, 32 of which cases also had coincident diagnoses] were studied. 96 % had enzyme-linked immunosorbant assay (ELISA) CSF data and 77 % had Luminex CSF data, with 43 and 46 controls for comparison, respectively. Aβ42, total, and phosphorylated tau181 were measured. Clinical and neuropathological diagnoses showed an 81.4 % overall agreement. Both assays showed high sensitivity and specificity to classify AD subjects against FTLD subjects and controls, and moderate sensitivity and specificity for classifying FTLD subjects against controls. However, among the cases with neuropathological diagnoses of AD plus another pathology (26.8 % of the sample), 69.4 % (ELISA) and 96.4 % (Luminex) were classified as AD according to their biomarker profiles. Use of clinical diagnosis instead of neuropathological diagnosis led to a 14–17 % underestimation of the biomarker accuracy. These results show that while CSF Aβ and tau assays are useful for diagnosis of AD and neurodegenerative diseases even at MCI stages, CSF diagnostic analyte panels that establish a positive diagnosis of Lewy body disease and FTLD are also needed, and must be established based on neuropathological rather than clinical diagnoses. PMID:22526019

  12. Cutoff probe using Fourier analysis for electron density measurement

    SciTech Connect

    Na, Byung-Keun; You, Kwang-Ho; Kim, Dae-Woong; Chang, Hong-Young; You, Shin-Jae; Kim, Jung-Hyung

    2012-01-15

    This paper proposes a new method for cutoff probe using a nanosecond impulse generator and an oscilloscope, instead of a network analyzer. The nanosecond impulse generator supplies a radiating signal of broadband frequency spectrum simultaneously without frequency sweeping, while frequency sweeping method is used by a network analyzer in a previous method. The transmission spectrum (S21) was obtained through a Fourier analysis of the transmitted impulse signal detected by the oscilloscope and was used to measure the electron density. The results showed that the transmission frequency spectrum and the electron density obtained with a new method are very close to those obtained with a previous method using a network analyzer. And also, only 15 ns long signal was necessary for spectrum reconstruction. These results were also compared to the Langmuir probe's measurements with satisfactory results. This method is expected to provide not only fast measurement of absolute electron density, but also function in other diagnostic situations where a network analyzer would be used (a hairpin probe and an impedance probe) by replacing the network analyzer with a nanosecond impulse generator and an oscilloscope.

  13. Cut-off fuel exhaust mechanism in fuel injection pump

    SciTech Connect

    Ikeuchi, H.

    1988-08-23

    This patent describes a fuel injection pump having an exhaust means for exhausting fuel from the fuel pump at the time of cut-off of fuel flow through the pump, comprising: a pump body for positioning in a pump space for containing fuel to be pumped, the pump body having a fuel passage extending thereinto from the pump space and a valve means in the fuel passage; a plunger barrel mounted in the pump body and having a plunger bore therein and a fuel intake port extending through the plunger barrel from a position opposite the inner end of the fuel passage into the plunger bore; a plunger rotatably and slidably mounted in the plunger bore and defining a pressurizing chamber at the inner end of the plunger bore; the plunger barrel having an oil passage extending from the end within which the pressurizing chamber is defined to the periphery of the plunger barrel; the pump body having a lead hole therethrough from a position opposite the end of the oil passage at the periphery of the plunger barrel to the outside of the pump body, and further having an oil chamber extending thereinto from a position on the pump body near the end of the oil passage and an exhaust passage extending from the inner part of the oil chamber to the outside of the pump body and opening into the pump space; a valve housing mounted on the pump body over the end of the lead hole and the opening into the oil chamber and having a valve guide hole therein opening into the oil chamber and having a valve seat around the end thereof and having an oil induction hole therethrough from a position opposite the end of the lead hole and into the valve guide hole.

  14. GUIDANCE FOR STATISTICAL DETERMINATION OF APPROPRIATE PERCENT MINORITY AND PERCENT POVERTY DISTRIBUTIONAL CUTOFF VALUES USING CENSUS DATA FOR AND EPA REGION II ENVIRONMENTAL JUSTICE PROJECT

    EPA Science Inventory

    The purpose of this report is to assist Region H by providing a statistical analysis identifying the areas with minority and below poverty populations known as "Community of Concern" (COC). The aim was to find a cutoff value as a threshold to identify a COC using demographic data...

  15. 2.4 Micrometer Cutoff Wavelength AlGaAsSb/InGaAsSb Phototransistors

    NASA Technical Reports Server (NTRS)

    Sulima, O. V.; Swaminathan, K.; Refaat, T. F.; Faleev, N. N.; Semenov, A. N.; Solov'ev, V. A.; Ivanov, S. V.; Abedin, M. N.; Singh, U. N.; Prather, D.

    2006-01-01

    We report the first AlGaAsSb/InGaAsSb phototransistors with a cutoff wavelength (50% of peak responsivity) of 2.4 micrometers operating in a broad range of temperatures. These devices are also the first AlGaAsSb/InGaAsSb heterojunction phototransistors (HPT) grown by molecular beam epitaxy (MBE). This work is a continuation of a preceding study, which was carried out using LPE (liquid phase epitaxy)-grown AlGaAsSb/InGaAsSb/GaSb heterostructures. Although the LPE-related work resulted in the fabrication of an HPT with excellent parameters [1-4], the room temperature cutoff wavelength of these devices (approximately 2.15 micrometers) was determined by fundamental limitations implied by the close-to-equilibrium growth from Al-In-Ga-As-Sb melts. As the MBE technique is free from the above limitations, AlGaAsSb/InGaAsSb/GaSb heterostructures for HPT with a narrower bandgap of the InGaAsSb base and collector - and hence sensitivity at longer wavelengths (lambda) - were grown in this work. Moreover, MBE - compared to LPE - provides better control over doping levels, composition and width of the AlGaAsSb and InGaAsSb layers, compositional and doping profiles, especially with regard to abrupt heterojunctions. The new MBE-grown HPT exhibited both high responsivity R (up to 2334 A/W for lambda=2.05 micrometers at -20 deg C.) and specific detectivity D* (up to 2.1 x 10(exp 11) cmHz(exp 1/2)/W for lambda=2.05 micrometers at -20 deg C).

  16. 15 CFR 70.1 - Cutoff dates and effect on enumeration and data tabulation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Cutoff dates and effect on enumeration and data tabulation. 70.1 Section 70.1 Commerce and Foreign Trade Regulations Relating to Commerce and... CHANGES FOR THE 2010 CENSUS § 70.1 Cutoff dates and effect on enumeration and data tabulation. For...

  17. 15 CFR 70.1 - Cutoff dates and effect on enumeration and data tabulation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Cutoff dates and effect on enumeration and data tabulation. 70.1 Section 70.1 Commerce and Foreign Trade Regulations Relating to Commerce and... CHANGES FOR THE 2010 CENSUS § 70.1 Cutoff dates and effect on enumeration and data tabulation. For...

  18. 15 CFR 70.1 - Cutoff dates and effect on enumeration and data tabulation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Cutoff dates and effect on enumeration and data tabulation. 70.1 Section 70.1 Commerce and Foreign Trade Regulations Relating to Commerce and... CHANGES FOR THE 2010 CENSUS § 70.1 Cutoff dates and effect on enumeration and data tabulation. For...

  19. 15 CFR 70.1 - Cutoff dates and effect on enumeration and data tabulation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Cutoff dates and effect on enumeration and data tabulation. 70.1 Section 70.1 Commerce and Foreign Trade Regulations Relating to Commerce and... CHANGES FOR THE 2010 CENSUS § 70.1 Cutoff dates and effect on enumeration and data tabulation. For...

  20. 15 CFR 70.1 - Cutoff dates and effect on enumeration and data tabulation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Cutoff dates and effect on enumeration and data tabulation. 70.1 Section 70.1 Commerce and Foreign Trade Regulations Relating to Commerce and... CHANGES FOR THE 2010 CENSUS § 70.1 Cutoff dates and effect on enumeration and data tabulation. For...

  1. 10 CFR 26.131 - Cutoff levels for validity screening and initial validity tests.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Cutoff levels for validity screening and initial validity tests. 26.131 Section 26.131 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Licensee Testing Facilities § 26.131 Cutoff levels for validity screening and initial validity tests. (a)...

  2. 10 CFR 26.131 - Cutoff levels for validity screening and initial validity tests.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Cutoff levels for validity screening and initial validity tests. 26.131 Section 26.131 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Licensee Testing Facilities § 26.131 Cutoff levels for validity screening and initial validity tests. (a)...

  3. 10 CFR 26.131 - Cutoff levels for validity screening and initial validity tests.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Cutoff levels for validity screening and initial validity tests. 26.131 Section 26.131 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Licensee Testing Facilities § 26.131 Cutoff levels for validity screening and initial validity tests. (a)...

  4. 10 CFR 26.131 - Cutoff levels for validity screening and initial validity tests.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Cutoff levels for validity screening and initial validity tests. 26.131 Section 26.131 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Licensee Testing Facilities § 26.131 Cutoff levels for validity screening and initial validity tests. (a)...

  5. 10 CFR 26.131 - Cutoff levels for validity screening and initial validity tests.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Cutoff levels for validity screening and initial validity tests. 26.131 Section 26.131 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Licensee Testing Facilities § 26.131 Cutoff levels for validity screening and initial validity tests. (a)...

  6. Extreme sediment pulses generated by bend cutoffs along a large meandering river

    NASA Astrophysics Data System (ADS)

    Zinger, Jessica A.; Rhoads, Bruce L.; Best, James L.

    2011-10-01

    In meandering rivers, bend cutoffs have long been recognized as an important mechanism of change in the path of the channel. Meander bend cutoffs can develop by the progressive migration of an elongated bend onto itself, which forms a neck cutoff, or by the erosion of a new channel across the neck of the bend, which is known as a chute cutoff. River cutoffs affect channel navigation, and form meander scars and oxbow lakes in river floodplains, which are important habitats for riparian ecosystems. The importance of cutoff processes in meander dynamics is well established, but the effects of cutoffs on overall sediment flux are poorly characterized. Here we use aerial imagery, global positioning system mapping and measurements of channel bathymetry to estimate the amount of sediment released by two chute cutoffs on the Wabash River in the Midwestern USA. We find that each event triggered the rapid delivery of sediment into the river, at rates that are one to five orders of magnitude larger than those produced by lateral migration of individual bends. We find that much of this material was deposited immediately downstream, at the confluence of the Wabash and Ohio rivers, which led to significant changes in channel morphology. This sedimentation ultimately impeded barge traffic and necessitated extensive dredging.

  7. Water surface and channel bed morphology change before and after a laboratory meander neck cutoff

    NASA Astrophysics Data System (ADS)

    Han, B.; Endreny, T. A.

    2012-12-01

    Meander evolution of narrowing point bars ultimately forms a straight reach and an associated oxbow lake after meand bend cutoff. Observing the water surface and bed topography change during the meander cutoff process allows scientists and engineers to better understand flow mechanisms in meandering rivers, predict river behavior following cutoff, and minimize damage to life and property. Theoretical river evolution model indicates that head loss between the upstream and downstream meander neck increases during meander evolution, and this leads to an increasing hydraulic gradient and intensification of the cutoff. Yet no detailed observations are available to support the theory. In this research, we establish a physical model of a meander cutoff in a 1.8 m * 3.7 m laboratory river table using 0.18 mm median diameter sand and river discharge of 100 mL/s. The initial meander is a highly curved meander with a sinuosity of 5.6. Erosion is initiated by stream flow and the meander goes through the cutoff process. Water surface elevation along the river, river bed topography, and groundwater head in the intra-meander zone are precisely measured with an accuracy of up to 0.4 mm using a close range photogrammetry technique and ultrasonic sensors. The measurements are taken every 5 hours before the cutoff, immediately after the cutoff, and 1 hour, 5 hours after the cutoff respectively. Our results show that hydraulic gradient gradually steepens crossing the meander neck before the cutoff. River bed elevation gradients crossing the meander neck are enlarged due to the continuous deposition at the upstream neck and erosion at the downstream neck. However, the river bed elevation differences is counter balanced by the water depth which is smaller at the upstream and larger at the downstream, and the head loss across the neck remains nearly the same during cutoff. Immediately after the meander cutoff, a cascade emerges, and then rapidly dissipates into the new channel during

  8. Symptom-dependent cut-offs of urine metanephrines improve diagnostic accuracy for detecting pheochromocytomas in two separate cohorts, compared to symptom-independent cut-offs.

    PubMed

    Cho, Yoon Young; Song, Kee-Ho; Kim, Young Nam; Ahn, Seong Hee; Kim, Hyeonmok; Park, Sooyoun; Suh, Sunghwan; Kim, Beom-Jun; Lee, Soo-Youn; Chun, Sail; Koh, Jung-Min; Lee, Seung Hun; Kim, Jae Hyeon

    2016-10-01

    The development of advanced imaging techniques has increased the detection of subclinical pheochromocytomas. Because of the substantial proportions of subclinical pheochromocytomas, measurement of urine metanephrine concentrations is crucial due to detect or exclude pheochromocytoma. Although urine metanephrines are elevated in symptomatic subjects, diagnostic cut-offs according to the presence of adrenergic symptoms have not been studied. Pheochromocytomas patients who underwent adrenalectomy at Samsung Medical Center and a control group were compared to determine cut-off concentrations of urine metanephrines. An independent population was analyzed for urine metanephrines with different kits to validate the improvement in diagnostic accuracy using adjusted cut-offs. Symptom-dependent cut-offs of urine metanephrines were higher for symptomatic patients (307 μg/day in males, 235 μg/day in females for urine metanephrine, and 1,045 μg/day in males and 457 μg/day in females for urine normetanephrine) than for asymptomatic patients (206 μg/day in males, 199 μg/day in females for urine metanephrine, and 489 μg/day in males and 442 μg/day in females for urine normetanephrine). Symptom-dependent cut-offs of urine metanephrines improved a specificity from 92.7 % to 96.3 % and a high sensitivity of 97.8 % was maintained. Using the Symptom-dependent cut-offs raised diagnostic accuracy by 5.5 % (p <0.001). Similar trend was also observed in an independent population using different hormone kits. Using symptom-dependent cut-offs of urine metanephrines in symptomatic patients for pheochromocytomas resulted in a significant improvement in diagnostic accuracy in two separate cohorts.

  9. Diagnostics principle of microwave cut-off probe for measuring absolute electron density

    SciTech Connect

    Jun, Hyun-Su

    2014-08-15

    A generalized diagnostics principle of microwave cut-off probe is presented with a full analytical solution. In previous studies on the microwave cut-off measurement of weakly ionized plasmas, the cut-off frequency ω{sub c} of a given electron density is assumed to be equal to the plasma frequency ω{sub p} and is predicted using electromagnetic simulation or electric circuit model analysis. However, for specific plasma conditions such as highly collisional plasma and a very narrow probe tip gap, it has been found that ω{sub c} and ω{sub p} are not equal. To resolve this problem, a generalized diagnostics principle is proposed by analytically solving the microwave cut-off condition Re[ε{sub r,eff}(ω = ω{sub c})] = 0. In addition, characteristics of the microwave cut-off condition are theoretically tested for correct measurement of the absolute electron density.

  10. Surface Tension of Methanol as a Function of cut-off Radius and Temperature Controllers

    NASA Astrophysics Data System (ADS)

    Obeidat, Abdalla; Jaradat, Adnan; Hamdan, Bushra

    Molecular dynamics is used to calculate the surface tension of van Leeuwen methanol. The van Leeuwen model of methanol is chosen over other models of methanol, since this model is widely used to study nucleation at low temperature. Usually, scientists use the cut-off radius to be three order of magnitude of segment diameter. In this study, we varied the cut-off radius to estimate the best cut-off at which the surface tension reaches its plateau. After deciding the best cut-off radius for van der Waals and Coulomb interactions (CUT-OFF and PME were used for Coulomb interaction), we varied the temperature controller (van-Housen, Berendsen, and v-rescale) to decide the best temperature controller to be used to study methanol. In all simulations, Gromacs is used at T =200-300K with periodic boundary conditions in all dimensions. JUST.

  11. Meander cutoff and the controls on the production of oxbow lakes

    NASA Astrophysics Data System (ADS)

    Constantine, José Antonio; Dunne, Thomas

    2008-01-01

    Using satellite images archived by Google EarthTM, we measuredchannel and oxbow-lake characteristics of 30 large meanderingrivers to identify the controls on the production of oxbow lakesby meander cutoff. Cutoff produced lognormal distributions oflake lengths within the studied reaches, and the geometric meanlake length of each population correlated positively and exponentiallywith sinuosity, due to more highly sinuous reaches being comprisedof longer meanders and to cutoff removing longer segments ofmore sinuous channels. We successfully predicted the size-frequencydistributions of lakes stored within the flood-plains of fivefreely meandering reaches using only channel sinuosity and anassumption of the variance about the geometric mean lake length,a variable that did not significantly vary between the studiedreaches. While the river's sinuosity remains steady, the temporalrate of cutoff can be estimated using channel sinuosity, thefraction by which cutoff reduces channel length, and the rateat which the reach lengthens by meander growth.

  12. Mach Cutoff Analysis and Results from NASA's Farfield Investigation of No-Boom Thresholds

    NASA Technical Reports Server (NTRS)

    Cliatt, Larry J., II; Hill, Michael A.; Haering, Edward A., Jr.

    2016-01-01

    In support of the ongoing effort by the National Aeronautics and Space Administration (NASA) to bring supersonic commercial travel to the public, the NASA Armstrong Flight Research Center and the NASA Langley Research Center, in partnership with other industry organizations and academia, conducted a flight research experiment to analyze acoustic propagation in the Mach cutoff shadow zone. The effort was conducted in the fall of 2012 and named the Farfield Investigation of No-boom Thresholds (FaINT). The test helped to build a dataset that will go toward further understanding of the unique acoustic propagation characteristics below Mach cutoff altitude. FaINT was able to correlate sonic boom noise levels measured below cutoff altitude with precise airplane flight conditions, potentially increasing the accuracy over previous studies. A NASA F-18B airplane made supersonic passes such that its Mach cutoff caustic would be at varying distances above a linear 60-microphone, 7375-ft (2247.9 m) long array. A TG-14 motor glider equipped with a microphone on its wing-tip also attempted to capture the same sonic boom waves above ground, but below the Mach cutoff altitude. This paper identified an appropriate metric for sonic boom waveforms in the Mach cutoff shadow zone called Perceived Sound Exposure Level; derived an empirical relationship between Mach cutoff flight conditions and noise levels in the shadow zone; validated a safe cutoff altitude theory presented by previous studies; analyzed the sensitivity of flight below Mach cutoff to unsteady atmospheric conditions and realistic aircraft perturbations; and demonstrated the ability to record sonic boom measurements over 5000 ft (1524.0 m) above ground level, but below Mach cutoff altitude.

  13. Estimation of Saliva Cotinine Cut-Off Points for Active and Passive Smoking during Pregnancy-Polish Mother and Child Cohort (REPRO_PL).

    PubMed

    Polanska, Kinga; Krol, Anna; Kaluzny, Pawel; Ligocka, Danuta; Mikolajewska, Karolina; Shaheen, Seif; Walton, Robert; Hanke, Wojciech

    2016-12-08

    A reliable assessment of smoking status has significant public health implications and is essential for research purposes. The aim of this study was to determine optimal saliva cotinine cut-off values for smoking during pregnancy. The analyses were based on data from 1771 women from the Polish Mother and Child Cohort. Saliva cotinine concentrations were assessed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-ESI + MS/MS). The saliva cotinine cut-off value for active smoking was established at 10 ng/mL (sensitivity 96%, specificity 95%) and for passive smoking at 1.5 ng/mL (sensitivity 63%, specificity 71%). About 5% of the self-reported non-smoking women were classified as smokers based on the cotinine cut-off value. Significantly more younger, single, and less educated self-reported non-smokers had a cotinine concentration higher than 10 ng/mL compared to those who were older, married, and who had a university degree. Close to 30% of the non-smokers who indicated that smoking was not allowed in their home could be classified as exposed to passive smoking based on the cut-off value. The study suggests that self-reported smoking status is a valid measure of active smoking, whereas in the case of passive smoking, a combination of questionnaire data and biomarker verification may be required.

  14. Estimation of Saliva Cotinine Cut-Off Points for Active and Passive Smoking during Pregnancy—Polish Mother and Child Cohort (REPRO_PL)

    PubMed Central

    Polanska, Kinga; Krol, Anna; Kaluzny, Pawel; Ligocka, Danuta; Mikolajewska, Karolina; Shaheen, Seif; Walton, Robert; Hanke, Wojciech

    2016-01-01

    A reliable assessment of smoking status has significant public health implications and is essential for research purposes. The aim of this study was to determine optimal saliva cotinine cut-off values for smoking during pregnancy. The analyses were based on data from 1771 women from the Polish Mother and Child Cohort. Saliva cotinine concentrations were assessed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-ESI + MS/MS). The saliva cotinine cut-off value for active smoking was established at 10 ng/mL (sensitivity 96%, specificity 95%) and for passive smoking at 1.5 ng/mL (sensitivity 63%, specificity 71%). About 5% of the self-reported non-smoking women were classified as smokers based on the cotinine cut-off value. Significantly more younger, single, and less educated self-reported non-smokers had a cotinine concentration higher than 10 ng/mL compared to those who were older, married, and who had a university degree. Close to 30% of the non-smokers who indicated that smoking was not allowed in their home could be classified as exposed to passive smoking based on the cut-off value. The study suggests that self-reported smoking status is a valid measure of active smoking, whereas in the case of passive smoking, a combination of questionnaire data and biomarker verification may be required. PMID:27941658

  15. Age-related differences in recommended anthropometric cut-off point validity to identify cardiovascular risk factors in ostensibly healthy women

    PubMed Central

    Björkelund, Cecilia; Guo, Xinxin; Skoog, Ingmar; Bosaeus, Ingvar; Lissner, Lauren

    2014-01-01

    Aim: To investigate validity of widely recommended anthropometric and total fat percentage cut-off points in screening for cardiovascular risk factors in women of different ages. Methods: A population-based sample of 1002 Swedish women aged 38, 50, 75 (younger, middle-aged and elderly, respectively) underwent anthropometry, health examinations and blood tests. Total fat was estimated (bioimpedance) in 670 women. Sensitivity, specificity of body mass index (BMI; ≥25 and ≥30), waist circumference (WC; ≥80 cm and ≥88 cm) and total fat percentage (TF; ≥35%) cut-off points for cardiovascular risk factors (dyslipidaemias, hypertension and hyperglycaemia) were calculated for each age. Cut-off points yielding high sensitivity together with modest specificity were considered valid. Women reporting hospital admission for cardiovascular disease were excluded. Results: The sensitivity of WC ≥80 cm for one or more risk factors was ~60% in younger and middle-aged women, and 80% in elderly women. The specificity of WC ≥80 cm for one or more risk factors was 69%, 57% and 40% at the three ages (p < .05 for age trends). WC ≥80 cm yielded ~80% sensitivity for two or more risk factors across all ages. However, specificity decreased with increasing age (p < .0001), being 33% in elderly. WC ≥88 cm provided better specificity in elderly women. BMI and TF % cut-off points were not better than WC. Conclusions: Validity of recommended anthropometric cut-off points in screening asymptomatic women varies with age. In younger and middle-age, WC ≥80 cm yielded high sensitivity and modest specificity for two or more risk factors, however, sensitivity for one or more risk factor was less than optimal. WC ≥88 cm showed better validity than WC ≥80 cm in elderly. Our results support age-specific screening cut-off points for women. PMID:25294689

  16. Upper and lower bounds for the speed of pulled fronts with a cut-off

    NASA Astrophysics Data System (ADS)

    Benguria, R. D.; Depassier, M. C.; Loss, M.

    2008-02-01

    We establish rigorous upper and lower bounds for the speed of pulled fronts with a cut-off. For all reaction terms of KPP type a simple analytic upper bound is given. The lower bounds however depend on details of the reaction term. For a small cut-off parameter the two leading order terms in the asymptotic expansion of the upper and lower bounds coincide and correspond to the Brunet-Derrida formula. For large cut-off parameters the bounds do not coincide and permit a simple estimation of the speed of the front.

  17. Integrated optical isolator based on nonreciprocal-mode cut-off.

    PubMed

    Hemme, H; Dötsch, H; Hertel, P

    1990-06-20

    A concept of an integrated optical isolator is presented which uses the TM(0) mode propagating perpendicular to the in-plane magnetization of a planar magnetooptical waveguide. The cut-off thickness of the waveguide depends on the propagation direction. If the magnetic film has a strong Faraday rotation and is weakly guiding, the cut-off thicknesses for forward and backward propagation differ markedly. Operating close to cut-off yields a large difference between coupling efficiencies to the waveguide for forward and backward propagation.

  18. The operation cutoff frequency of high electron mobility transistor measured by terahertz method

    SciTech Connect

    Zhu, Y. M. Zhuang, S. L.

    2014-07-07

    Commonly, the cutoff frequency of high electron mobility transistor (HEMT) can be measured by vector network analyzer (VNA), which can only measure the sample exactly in low frequency region. In this paper, we propose a method to evaluate the cutoff frequency of HEMT by terahertz (THz) technique. One example shows the cutoff frequency of our HEMT is measured at ∼95.30 GHz, which is reasonable agreement with that estimated by VNA. It is proved THz technology a potential candidate for the substitution of VNA for the measurement of high-speed devices even up to several THz.

  19. The Development of a Dynamic Geomagnetic Cutoff Rigidity Model for the International Space Station

    NASA Technical Reports Server (NTRS)

    Smart, D. F.; Shea, M. A.

    1999-01-01

    We have developed a computer model of geomagnetic vertical cutoffs applicable to the orbit of the International Space Station. This model accounts for the change in geomagnetic cutoff rigidity as a function of geomagnetic activity level. This model was delivered to NASA Johnson Space Center in July 1999 and tested on the Space Radiation Analysis Group DEC-Alpha computer system to ensure that it will properly interface with other software currently used at NASA JSC. The software was designed for ease of being upgraded as other improved models of geomagnetic cutoff as a function of magnetic activity are developed.

  20. Measurement of effective sheath width around cutoff probe in low-pressure plasmas

    SciTech Connect

    Kim, D. W.; Oh, W. Y.; You, S. J. Kim, J. H.; Chang, H. Y.

    2014-05-15

    Previous studies indicated that the measurement results of microwave probes can be improved by applying the adequate sheath width to their measurement models, and consequently the sheath width around the microwave probe tips has become very important information for microwave probe diagnostics. In this paper, we propose a method for measuring the argon plasma sheath width around the cutoff probe tips by applying the circuit model to the cutoff probe phase spectrum. The measured sheath width of the cutoff probe was found to be in good agreement with the floated sheath width calculated from the Child-Langmuir sheath law. The physical reasons for a discrepancy between the two measurements are also discussed.

  1. Cutoff frequencies and cross fingerings in baroque, classical, and modern flutes

    NASA Astrophysics Data System (ADS)

    Wolfe, Joe; Smith, John

    2003-10-01

    Baroque, classical, and modern flutes have successively more and larger tone holes. This paper reports measurements of the standing waves in the bores of instruments representing these three classes. It presents the frequency dependence of propagation of standing waves in lattices of open tone holes and compares these measurements with the cutoff frequency: the frequency at which, in an idealized system, the standing waves propagate without loss in such a lattice. It also reports the dependence of the sound field in the bore of the instrument as a function of both frequency and position along the bore for both simple and ``cross fingerings'' (configurations in which one or more tone holes are closed below an open hole). These measurements show how ``cross fingerings'' produce a longer standing wave, a technique used to produce the nondiatonic notes on instruments with a small number of tone holes closed only by the unaided fingers. They also show why the changes from baroque to classical to modern gave the instruments a louder, brighter sound and a greater range.

  2. Cutoff frequencies and cross fingerings in baroque, classical, and modern flutes.

    PubMed

    Wolfe, Joe; Smith, John

    2003-10-01

    Baroque, classical, and modern flutes have successively more and larger tone holes. This paper reports measurements of the standing waves in the bores of instruments representing these three classes. It presents the frequency dependence of propagation of standing waves in lattices of open tone holes and compares these measurements with the cutoff frequency: the frequency at which, in an idealized system, the standing waves propagate without loss in such a lattice. It also reports the dependence of the sound field in the bore of the instrument as a function of both frequency and position along the bore for both simple and "cross fingerings" (configurations in which one or more tone holes are closed below an open hole). These measurements show how "cross fingerings" produce a longer standing wave, a technique used to produce the nondiatonic notes on instruments with a small number of tone holes closed only by the unaided fingers. They also show why the changes from baroque to classical to modern gave the instruments a louder, brighter sound and a greater range.

  3. Tumor Budding in Colorectal Carcinoma: Confirmation of Prognostic Significance and Histologic Cutoff in a Population-based Cohort

    PubMed Central

    Graham, Rondell P.; Vierkant, Robert A.; Tillmans, Lori S.; Wang, Alice H.; Laird, Peter W; Weisenberger, Daniel J.; Lynch, Charles F.; French, Amy J.; Slager, Susan L.; Raissian, Yassaman; Garcia, Joaquin J.; Kerr, Sarah E.; Lee, Hee Eun; Thibodeau, Stephen N.; Cerhan, James R.; Limburg, Paul J.; Smyrk, Thomas C.

    2015-01-01

    Tumor budding in colorectal carcinoma has been associated with poor outcome in multiple studies, but the absence of an established histologic cutoff for “high” tumor budding, heterogeneity in study populations and varying methods for assessing tumor budding have hindered widespread incorporation of this parameter in clinical reports. We used an established scoring system in a population-based cohort to determine a histologic cutoff for “high” tumor budding and confirm its prognostic significance. We retrieved hematoxylin and eosin-stained sections from 553 incident colorectal carcinoma cases. Each case was previously characterized for select molecular alterations and survival data. Interobserver agreement was assessed between two GI pathologists and a group of four general surgical pathologists. High budding (≥10 tumor buds in a 20× objective field) was present in 32% of cases, low budding in 46% and no budding in 22%. High tumor budding was associated with advanced pathologic stage (p<0.001), microsatellite stability (p=0.005), KRAS mutation (p=0.010) and on multivariate analysis with a greater than two times risk of cancer-specific death (HR=2.57 (1.27, 5.19)). After multivariate adjustment, via penalized smoothing splines, we found increasing tumor bud counts from 5 upward to be associated with an increasingly shortened cancer-specific survival. By this method, a tumor bud count of 10 corresponded to approximately 2.5 times risk of cancer –specific death. The interobserver agreement was good with weighted kappa of 0.70 for two GI pathologists over 121 random cases and 0.72 between all six pathologists for 20 random cases. Using an established method to assess budding on routine histologic stains, we have shown a cutoff of 10 for high tumor budding is independently associated with a significantly worse prognosis. The reproducibility data provide support for the routine widespread implementation of tumor budding in clinical reports. PMID:26200097

  4. Flow Characteristics with Variations of Cut-Off Angle of Multi-Blade Fan for Ventilation

    NASA Astrophysics Data System (ADS)

    Kang, Kyung Jun; Park, Jun Geon; Shin, You Hwan; Kim, Kwang Ho

    2010-06-01

    This study investigated on details of flow characteristics of a multi-blade fan for domestic ventilation. Experiments and analysis were carried out to describe on flow pattern with variations of cut-off angle near the scroll-housing throat, which were performed by PIV measurement for the flow field and by total pressure probes. The stagnation point at cut-off region of the fan moves to the exit of the scroll housing as cut-off angle increases. The movement of stagnation point and the variation of throat area of the scroll housing influence to the distribution of velocity magnitude at the exit of the fan. Furthermore, a large distortion of the velocity distribution at the scroll exit causes to increase mixing loss along the flow path. The improvement of the fan design on cut-off is expected through understanding the flow pattern.

  5. THE ACOUSTIC CUTOFF FREQUENCY OF THE SUN AND THE SOLAR MAGNETIC ACTIVITY CYCLE

    SciTech Connect

    Jimenez, A.; Palle, P. L.; Garcia, R. A.

    2011-12-20

    The acoustic cutoff frequency-the highest frequency for acoustic solar eigenmodes-is an important parameter of the solar atmosphere as it determines the upper boundary of the p-mode resonant cavities. At frequencies beyond this value, acoustic disturbances are no longer trapped but are traveling waves. Interference among them gives rise to higher-frequency peaks-the pseudomodes-in the solar acoustic spectrum. The pseudomodes are shifted slightly in frequency with respect to p-modes, making possible the use of pseudomodes to determine the acoustic cutoff frequency. Using data from the GOLF and VIRGO instruments on board the Solar and Heliospheric Observatory spacecraft, we calculate the acoustic cutoff frequency using the coherence function between both the velocity and intensity sets of data. By using data gathered by these instruments during the entire lifetime of the mission (1996 until the present), a variation in the acoustic cutoff frequency with the solar magnetic activity cycle is found.

  6. Variation of Acoustic Cutoff Period with Height in the Solar Atmosphere: Theory versus Observations

    NASA Astrophysics Data System (ADS)

    Murawski, K.; Musielak, Z. E.; Konkol, P.; Wiśniewska, A.

    2016-08-01

    Recently Wiśniewska et al. demonstrated observationally how the acoustic cutoff frequency varies with height in the solar atmosphere including the upper photosphere and the lower and middle chromosphere, and showed that the observational results cannot be accounted for by the existing theoretical formulas for the acoustic cutoff. In order to reproduce the observed variation of the cutoff with atmospheric height, numerical simulations of impulsively generated acoustic waves in the solar atmosphere are performed, and the spectral analysis of temporal wave profiles is used to compute numerically changes of the acoustic cutoff with height. Comparison of the numerical results with the observational data shows good agreement, which clearly indicates that the obtained results may be used to determine the structure of the background solar atmosphere.

  7. Doping-Spike PtSi Schottky Infrared Detectors with Extended Cutoff Wavelengths

    NASA Technical Reports Server (NTRS)

    Lin, T. L.; Park, J. S.; Gunapala, S. D.; Jones, E. W.; Castillo, H. M. Del

    1994-01-01

    A technique incorporating a p+ doping spike at the silicide/Si interface to reduce the effective Schottky barrier of the silicide infrared detectors and thus extend the cutoff wavelength has been developed.

  8. Single-mode waveguide optical isolator based on direction-dependent cutoff frequency.

    PubMed

    Tang, Lingling; Drezdzon, Samuel M; Yoshie, Tomoyuki

    2008-09-29

    A single-mode-waveguide optical isolator based on propagation direction dependent cut-off frequency is proposed. The isolation bandwidth is the difference between the cut-off frequencies of the lowest forward and backward propagating modes. Perturbation theory is used for analyzing the correlation between the material distribution and the bandwidth. The mode profile determines an appropriate distribution of non-reciprocal materials.

  9. Routine inspection effort required for verification of a nuclear material production cutoff convention

    SciTech Connect

    Fishbone, L.G.; Sanborn, J.

    1995-08-01

    Preliminary estimates of the inspection effort to verify a Nuclear Material Cutoff Convention are presented. The estimates are based on a database of about 650 facilities in a total of eight states, the five nuclear-weapons states and three ``threshold`` states plus facility-specific inspection requirements. Typical figures for inspection requirements for specific facility types derive from IAEA experience, where applicable. Alternative estimates of inspection effort are used in cutoff options where full IAEA safeguards are not stipulated.

  10. Global warming precipitation accumulation increases above the current-climate cutoff scale

    PubMed Central

    Sahany, Sandeep; Stechmann, Samuel N.; Bernstein, Diana N.

    2017-01-01

    Precipitation accumulations, integrated over rainfall events, can be affected by both intensity and duration of the storm event. Thus, although precipitation intensity is widely projected to increase under global warming, a clear framework for predicting accumulation changes has been lacking, despite the importance of accumulations for societal impacts. Theory for changes in the probability density function (pdf) of precipitation accumulations is presented with an evaluation of these changes in global climate model simulations. We show that a simple set of conditions implies roughly exponential increases in the frequency of the very largest accumulations above a physical cutoff scale, increasing with event size. The pdf exhibits an approximately power-law range where probability density drops slowly with each order of magnitude size increase, up to a cutoff at large accumulations that limits the largest events experienced in current climate. The theory predicts that the cutoff scale, controlled by the interplay of moisture convergence variance and precipitation loss, tends to increase under global warming. Thus, precisely the large accumulations above the cutoff that are currently rare will exhibit increases in the warmer climate as this cutoff is extended. This indeed occurs in the full climate model, with a 3 °C end-of-century global-average warming yielding regional increases of hundreds of percent to >1,000% in the probability density of the largest accumulations that have historical precedents. The probabilities of unprecedented accumulations are also consistent with the extension of the cutoff. PMID:28115693

  11. Adapting the D-dimer cutoff for thrombosis detection in elderly outpatients.

    PubMed

    Andro, Marion; Righini, Marc; Le Gal, Grégoire

    2013-06-01

    D-dimer measurement is an important step in diagnostic strategies for venous thromboembolism. It allows the safe ruling out of the diagnosis with no need for imaging tests in approximately 30% of outpatients. However, the usefulness of d-dimer is limited in elderly patients; the likelihood of a negative d-dimer strongly decreases with age, making physicians reluctant to order the test. Several attempts to improve the performance of D-dimer in elderly patients have been pursued. Recently, an age-adjusted cutoff was derived; the optimal cutoff value (in µg/l) appears to be equal to the patient's age (in years) multiplied by ten in patients over 50 years of age with a low pretest clinical risk of venous thromboembolism. This age-adjusted cutoff value has been extensively and externally validated in retrospective studies that included mostly outpatients with suspected deep vein thrombosis or pulmonary embolism and used various quantitative D-dimer assays. All available studies confirmed the increased usefulness and similar safety of the age-adjusted cutoff compared with the conventional cutoff, the most important benefit being obtained in elderly patients. However, before any recommendation for clinical practice can be made, a prospective diagnostic management outcome study is lacking, in which all low clinical risk patients with D-dimer levels below their age-adjusted cutoff would be left untreated with no further diagnostic testing.

  12. Global warming precipitation accumulation increases above the current-climate cutoff scale

    NASA Astrophysics Data System (ADS)

    Neelin, J. David; Sahany, Sandeep; Stechmann, Samuel N.; Bernstein, Diana N.

    2017-02-01

    Precipitation accumulations, integrated over rainfall events, can be affected by both intensity and duration of the storm event. Thus, although precipitation intensity is widely projected to increase under global warming, a clear framework for predicting accumulation changes has been lacking, despite the importance of accumulations for societal impacts. Theory for changes in the probability density function (pdf) of precipitation accumulations is presented with an evaluation of these changes in global climate model simulations. We show that a simple set of conditions implies roughly exponential increases in the frequency of the very largest accumulations above a physical cutoff scale, increasing with event size. The pdf exhibits an approximately power-law range where probability density drops slowly with each order of magnitude size increase, up to a cutoff at large accumulations that limits the largest events experienced in current climate. The theory predicts that the cutoff scale, controlled by the interplay of moisture convergence variance and precipitation loss, tends to increase under global warming. Thus, precisely the large accumulations above the cutoff that are currently rare will exhibit increases in the warmer climate as this cutoff is extended. This indeed occurs in the full climate model, with a 3 °C end-of-century global-average warming yielding regional increases of hundreds of percent to >1,000% in the probability density of the largest accumulations that have historical precedents. The probabilities of unprecedented accumulations are also consistent with the extension of the cutoff.

  13. Global warming precipitation accumulation increases above the current-climate cutoff scale.

    PubMed

    Neelin, J David; Sahany, Sandeep; Stechmann, Samuel N; Bernstein, Diana N

    2017-02-07

    Precipitation accumulations, integrated over rainfall events, can be affected by both intensity and duration of the storm event. Thus, although precipitation intensity is widely projected to increase under global warming, a clear framework for predicting accumulation changes has been lacking, despite the importance of accumulations for societal impacts. Theory for changes in the probability density function (pdf) of precipitation accumulations is presented with an evaluation of these changes in global climate model simulations. We show that a simple set of conditions implies roughly exponential increases in the frequency of the very largest accumulations above a physical cutoff scale, increasing with event size. The pdf exhibits an approximately power-law range where probability density drops slowly with each order of magnitude size increase, up to a cutoff at large accumulations that limits the largest events experienced in current climate. The theory predicts that the cutoff scale, controlled by the interplay of moisture convergence variance and precipitation loss, tends to increase under global warming. Thus, precisely the large accumulations above the cutoff that are currently rare will exhibit increases in the warmer climate as this cutoff is extended. This indeed occurs in the full climate model, with a 3 °C end-of-century global-average warming yielding regional increases of hundreds of percent to >1,000% in the probability density of the largest accumulations that have historical precedents. The probabilities of unprecedented accumulations are also consistent with the extension of the cutoff.

  14. The Fate of Oxbow Lakes Determined by Mechanisms of Meander Cutoff

    NASA Astrophysics Data System (ADS)

    Constantine, José; Dieras, Pauline; Hales, Tristram; Piégay, Hervé

    2016-04-01

    Oxbow lakes are some of the most widespread and distinctive landforms along meandering rivers, but their persistence as aquatic habitat may depend on the mechanisms of their formation. Based on an archive of historical aerial photographs and maps of seven meandering rivers, we use changes in water-surface area as a proxy for alluviation to demonstrate that oxbows and abandoned channels created by neck cutoff can persist in the floodplain for centuries, whereas the oxbows and abandoned channels created by chute cutoff appear to undergo rapid alluviation following their formation. Differences in the persistence of the thirty-seven oxbows and abandoned channels under study are due to differences in the planform characteristics that are associated with each cutoff mechanism. Using theoretical and empirical relations that describe the conditions required for the conveyance of riverbed sediment, we show that neck cutoff results in the successful transition of persistent oxbows because they lack the planform characteristics required for sustaining the flows needed to prevent plug formation. The angle by which flow is diverted and the magnitude by which the river is locally steepened is significantly greater for channels created by neck cutoff than for those created by chute cutoff.

  15. Identification of cutoff points for Homeostatic Model Assessment for Insulin Resistance index in adolescents: systematic review

    PubMed Central

    de Andrade, Maria Izabel Siqueira; Oliveira, Juliana Souza; Leal, Vanessa Sá; da Lima, Niedja Maria Silva; Costa, Emília Chagas; de Aquino, Nathalia Barbosa; de Lira, Pedro Israel Cabral

    2016-01-01

    Abstract Objective: To identify cutoff points of the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index established for adolescents and discuss their applicability for the diagnosis of insulin resistance in Brazilian adolescents. Data source: A systematic review was performed in the PubMed, Lilacs and SciELO databases, using the following descriptors: "adolescents", "insulin resistance" and "Receiver Operating Characteristics Curve". Original articles carried out with adolescents published between 2005 and 2015 in Portuguese, English or Spanish languages, which included the statistical analysis using Receiver Operating Characteristics Curve to determine the index cutoff (HOMA-IR) were included. Data synthesis: A total of 184 articles were identified and after the study phases were applied, seven articles were selected for the review. All selected studies established their cutoffs using a Receiver Operating Characteristics Curve, with the lowest observed cutoff of 1.65 for girls and 1.95 for boys and the highest of 3.82 for girls and 5.22 for boys. Of the studies analyzed, one proposed external validity, recommending the use of the HOMA-IR cutoff>2.5 for both genders. Conclusions: The HOMA-IR index constitutes a reliable method for the detection of insulin resistance in adolescents, as long as it uses cutoffs that are more adequate for the reality of the study population, allowing early diagnosis of insulin resistance and enabling multidisciplinary interventions aiming at health promotion of this population. PMID:26559605

  16. A wide range of activity duration cutoffs provided unbiased estimates of exposure to computer use.

    PubMed

    Chang, Che-Hsu; Johnson, Peter W; Dennerlein, Jack T

    2008-12-01

    Integrative computer usage monitors have become widely used in epidemiologic studies to investigate the exposure-response relationship of computer-related musculoskeletal disorders. These software programs typically estimate the exposure duration of computer use by summing precisely recorded durations of input device activities and durations of inactivity periods shorter than a predetermined activity duration cutoff value, usually 30 or 60 sec. The goal of this study was to systematically compare the validity of a wide range of cutoff values. Computer use activity of 20 office workers was observed for 4 consecutive hours using both a video camera and a usage monitor. Video recordings from the camera were analyzed using specific observational criteria to determine computer use duration. This observed duration then served as the reference and was compared with 238 estimates of computer use duration calculated from the usage monitor data using activity duration cutoffs ranging from 3 to 240 sec in 1-sec increments. Estimates calculated with cutoffs ranging from 28 to 60 sec were highly correlated with the observed duration (Spearman's correlation 0.87 to 0.92) and had nearly ideal linear relationships with the observed duration (slopes and r-squares close to one, and intercepts close to zero). For the same range of cutoff values, when the observed and estimated durations were compared for dichotomous exposure classification across participants, minimal exposure misclassification was observed. It is concluded that activity duration cutoffs ranging from 28 to 60 sec provided unbiased estimates of computer use duration.

  17. Environmental Effects of Tennessee-Tombigbee Project Cutoff Bendways.

    DTIC Science & Technology

    1982-08-01

    34 Fisheries Management, John Wiley and Sons, New York, pp 265-295. Patriarch, M. H., and Campbell, R. S . 1958. "The Development of the Fish Population in...34Effects of By-pass Canals on Fish Populations of the Lower Alabama River," Contract Report No. DACW01- 73-C-0017, U. S . Army Engineer District, Mobile...Miscellaneous Paper E-82-4 11,/ d / - 4. TITLE (ad &ShfItle) S . TYPE OF REPORT & PERIOD COVERED ENVIRONMENTAL EFFECTS OF TENNESSEE-TOMBIGBEE Final

  18. Prevalence of the metabolic syndrome and determination of optimal cut-off values of waist circumference in university employees from Angola

    PubMed Central

    Magalhães, Pedro; Capingana, Daniel P; Mill, José G

    2014-01-01

    Summary Background Estimates of the prevalence of the metabolic syndrome in Africans may be inconsistent due to lack of African-specific cut-off values of waist circumference (WC). This study determined the prevalence of the metabolic syndrome and defined optimal values of WC in Africans. Methods This cross-sectional study collected demographic, anthropometric and clinical data of 615 Universitary employees, in Luanda, Angola. The metabolic syndrome was defined using the third report of the National Cholesterol Education Program Adult Treatment Panel (ATPIII) and the Joint Interim Statement (JIS) criteria. Receiver operating characteristics curves were constructed to assess cut-off values of WC. Results The crude prevalence of the metabolic syndrome was higher with the JIS definition (27.8%, age-standardised 14.1%) than with the ATP III definition (17.6%, age-standardised 8.7%). Optimal cut-off values of WC were 87.5 and 80.5 cm in men and women, respectively. Conclusions There was a high prevalence of the metabolic syndrome among our African subjects. Our data suggest different WC cut-off values for Africans in relation to other populations. PMID:24626517

  19. Upper cut-off rigidity for corotation anisotropy during solar activity cycles 20 and 21

    NASA Technical Reports Server (NTRS)

    Ahluwalia, H. S.; Riker, J. F.

    1985-01-01

    At the Eleventh International Conference on Cosmic Rays in 1969, the results of a study of the solar diurnal variations of solar rays observed during the ascending phase of solar activity cycle twenty was discussed. The diurnal variation, observed underground during 1965-68 period, and results from an extraterrestrial anisotropy having a continuously increasing upper cut-off rigidity R sub c were reported. However, the coupling functions applicable to underground telescopes were controversial then. This situation has improved now. Those results wsere re-examined and extended to cover the period 1965-78. The coupling functions given by Murakami et al. for underground muons and those given by Lockwood and Weber for neutron monitors were used showed that a great deal of care should be exercised in the value of R sub c was calculated. Although numerical values of R sub c are a little different, the trend for 1965-68 period remains unchanged. Highest value of R sub c occur in 1970 and the lowest value occurs in 1976.

  20. Mechanically robust 39 GHz cut-off frequency graphene field effect transistors on flexible substrates.

    PubMed

    Wei, Wei; Pallecchi, Emiliano; Haque, Samiul; Borini, Stefano; Avramovic, Vanessa; Centeno, Alba; Amaia, Zurutuza; Happy, Henri

    2016-08-07

    Graphene has been regarded as a promising candidate channel material for flexible devices operating at radio-frequency (RF). In this work we fabricated and fully characterized double bottom-gate graphene field effect transistors on flexible polymer substrates for high frequency applications. We report a record high as-measured current gain cut-off frequency (ft) of 39 GHz. The corresponding maximum oscillation frequency (fmax) is 13.5 GHz. These state of the art high frequency performances are stable against bending, with a typical variation of around 10%, for a bending radius of up to 12 mm. To demonstrate the reliability of our devices, we performed a fatigue stress test for RF-GFETs which were dynamically bend tested 1000 times at 1 Hz. The devices are mechanically robust, and performances are stable with typical variations of 15%. Finally we investigate thermal dissipation, which is a critical parameter for flexible electronics. We show that at the optimum polarization the normalized power dissipated by the GFETs is about 0.35 mW μm(-2) and that the substrate temperature is around 200 degree centigrade. At a higher power, irreversible degradations of the performances are observed. Our study on state of the art flexible GFETs demonstrates mechanical robustness and stability upon heating, two important elements to assess the potential of GFETs for flexible electronics.

  1. The Economic Benefits of Personnel Selection Using Ability Tests: A State of the Art Review Including a Detailed Analysis of the Dollar Benefit of U.S. Employment Service Placements and a Critique of the Low-Cutoff Method of Test Use. USES Test Research Report No. 47.

    ERIC Educational Resources Information Center

    Hunter, John E.

    The economic impact of optimal selection using ability tests is far higher than is commonly known. For small organizations, dollar savings from higher productivity can run into millions of dollars a year. This report estimates the potential savings to the Federal Government as an employer as being 15.61 billion dollars per year if tests were given…

  2. Resistive magneto-hydrodynamical cut-off of Alfvén wave in fully ionized plasmas

    SciTech Connect

    Vranjes, J.; Kono, M.

    2014-01-15

    The term cut-off in the theory of the Alfvén wave is used to describe several different phenomena. In this work, the cut-off due to magnetohydrodynamic resistive damping in fully ionized plasmas is revisited. This cut-off requires short enough wavelengths, it is routinely discussed in numerous works, and graphs depicting it are available even in textbooks. We show that this cut-off is hardly ever possible in real plasmas. This is due to the fact that some essential criteria and conditions become strongly violated in order to achieve the cut-off.

  3. Experience with a urine opiate screening and confirmation cutoff of 2000 ng/mL.

    PubMed

    Fraser, A D; Worth, D

    1999-10-01

    Until recently, most laboratories used an opiate immunoassay screening and confirmation cutoff value of 300 ng/mL for codeine and morphine detection by gas chromatography-mass spectrometry (GC-MS). The cutoff value for opiates was increased to 2000 ng/mL or higher in various laboratories because of concerns that small doses of codeine and foods containing poppy seeds would give a positive opiate-screening result. Workplace drug-testing programs in the U.S. raised the opiate cutoff value to 2000 ng/mL on 30 November 1998. The objective of this study is to describe the results of opiate testing of 8600 urine specimens collected over 24 months with a 2000-ng/mL screening and confirmation (codeine and morphine) cutoff value. Specimens were screened by the EMITdau opiate assay using an in-house 2000-ng/mL morphine calibrator. Presumptive positive findings (N = 621) were analyzed quantitatively by GC-MS for codeine and morphine. One hundred and eighty six urine specimens were positive for codeine and morphine (> 2000 ng/mL), 298 specimens were positive for codeine only (> 2000 ng/mL) and 26 specimens were positive for morphine only (> 2000 ng/mL). All remaining specimens had codeine and morphine values < 2000 ng/mL. The codeine and morphine confirmation rate in this program reduced from 7.1% in 1994-1996 (300-ng/mL cutoff) to 2.1% in 1997-1998 with a 2000-ng/mL cutoff value. The codeine-only confirmation rate lowered from 6.6% (300-ng/mL cutoff) to 3.4% (2000-ng/mL cutoff). It was concluded that increasing opiate screening and codeine and morphine confirmation cutoff values led to > 300% reduction in the confirmed-positive rate for codeine and morphine and a 47% reduction in codeine-only confirmations in a urine drug-testing program where codeine was the major opiate used.

  4. The critical wave speed for the Fisher Kolmogorov Petrowskii Piscounov equation with cut-off

    NASA Astrophysics Data System (ADS)

    Dumortier, Freddy; Popovic, Nikola; Kaper, Tasso J.

    2007-04-01

    The Fisher-Kolmogorov-Petrowskii-Piscounov (FKPP) equation with cut-off was introduced in (Brunet and Derrida 1997 Shift in the velocity of a front due to a cut-off Phys. Rev. E 56 2597-604) to model N-particle systems in which concentrations less than ɛ = 1/N are not attainable. It was conjectured that the cut-off function, which sets the reaction terms to zero if the concentration is below the small threshold ɛ, introduces a substantial shift in the propagation speed of the corresponding travelling waves. In this paper, we prove the conjecture of Brunet and Derrida, showing that the speed of propagation is given by c_crit(\\varepsilon)=2-{\\pi^2}/{(\\ln\\varepsilon)^2}+\\cal{O}((\\ln\\varepsilon)^{-3}) , as ɛ → 0, for a large class of cut-off functions. Moreover, we extend this result to a more general family of scalar reaction-diffusion equations with cut-off. The main mathematical techniques used in our proof are the geometric singular perturbation theory and the blow-up method, which lead naturally to the identification of the reasons for the logarithmic dependence of ccrit on ɛ as well as for the universality of the corresponding leading-order coefficient (π2).

  5. Flood duration and chute cutoff formation in a wandering gravel-bed river

    NASA Astrophysics Data System (ADS)

    Sawyer, A.; Wilcox, A. C.

    2015-12-01

    Chute cutoffs occur when a bypass or "chute" channel incises across a bar or low floodplain area, re-distributing water and sediment. Cutoffs result from a setup and a triggering event, typically during overbank flow, but the combined effect of magnitude and duration on potential erosion in in-channel and overbank areas is still poorly constrained. Here we investigated how overbank flow duration impacts cutoff formation and spatiotemporal shear stress patterns in a wandering gravel-bed river. We applied a two-dimensional hydraulic model to a recently reconstructed reach of the Clark Fork River in western Montana that experienced chute cutoffs during a long-duration flood in 2011. Hydrographs with increasing durations exceeding overbank were simulated; for each magnitude-duration combination, various metrics were quantified for in-channel and overbank areas separately. We confirm the hypothesized importance of floodplain elevation, vegetation presence, chute-channel inlet entrance location, and high overbank shear stress zones at bend apexes on cutoff occurrence. Floodplain width plays an important role in controlling unit discharge such that overbank areas are more competent in a narrower floodplain conveyance corridor. Duration controls cumulative flow exceeding sediment mobility thresholds, having the largest effect in overbank areas. Side channels at the reconstructed study site act like naturally formed incipient chutes. This work describes a complex floodplain system characteristic of wandering gravel-bed rivers with implications for understanding morphodynamic evolution, river restoration, and flow management in regulated rivers.

  6. PAMELA's measurements of geomagnetic cutoff variations during the 14 December 2006 storm

    NASA Astrophysics Data System (ADS)

    Adriani, O.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Boezio, M.; Bogomolov, E. A.; Bongi, M.; Bonvicini, V.; Bottai, S.; Bruno, A.; Cafagna, F.; Campana, D.; Carlson, P.; Casolino, M.; Castellini, G.; De Donato, C.; Nolfo, G. A.; De Santis, C.; De Simone, N.; Di Felice, V.; Galper, A. M.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S.; Krutkov, S. Y.; Kvashnin, A. N.; Leonov, A.; Malakhov, V.; Marcelli, L.; Martucci, M.; Mayorov, A. G.; Menn, W.; Mergé, M.; Mikhailov, V. V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Munini, R.; Osteria, G.; Palma, F.; Panico, B.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S. B.; Sarkar, R.; Scotti, V.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stozhkov, Y. I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.

    2016-03-01

    Data from the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) satellite experiment were used to measure the geomagnetic cutoff for high-energy (≳ 80MeV) protons during the 14 December 2006 geomagnetic storm. The variations of the cutoff latitude as a function of rigidity were studied on relatively short timescales, corresponding to spacecraft orbital periods (˜94 min). Estimated cutoff values were compared with those obtained by means of a trajectory-tracing approach based on a dynamical empirical modeling of the Earth's magnetosphere. We found significant variations in the cutoff latitude, with a maximum suppression of ˜7° at lowest rigidities during the main phase of the storm. The observed reduction in the geomagnetic shielding and its temporal evolution were related to the changes in the magnetospheric configuration, investigating the role of interplanetary magnetic field, solar wind, and geomagnetic parameters. PAMELA's results represent the first direct measurement of geomagnetic cutoffs for protons with kinetic energies in the sub-GeV and GeV region.

  7. Waist circumference cutoff points for central obesity in the Korean elderly population.

    PubMed

    So, Eun Sun; Yoo, Kwang Soo

    2015-02-01

    The aim is to determine the appropriate cutoff values of waist circumference (WC) for an increased risk of the metabolic syndrome in the Korean elderly population. We analyzed the WC cutoff values of four groups divided according to sex and age with a total of 2,224 elderly participants aged 65 years old and above from the Fourth Korean National Health and Nutrition Examination Survey using the receiver operating characteristic curve and multiple logistic regression. The WC cutoff values associated with an increased risk of metabolic syndrome were 89.6 cm for men and 90.5 cm for women for those who were 65 to 74 years old, and 89.9 cm for men and 87.9 cm for women for those who were 75 years old or older. WC cutoff points for estimating metabolic risk are similar in elderly men and women. Age-specific optimal WC cutoff points should be considered especially for elderly women in screening for metabolic syndrome.

  8. Epidemiological cut-off values for Flavobacterium psychrophilum MIC data generated by a standard test protocol.

    PubMed

    Smith, P; Endris, R; Kronvall, G; Thomas, V; Verner-Jeffreys, D; Wilhelm, C; Dalsgaard, I

    2016-02-01

    Epidemiological cut-off values were developed for application to antibiotic susceptibility data for Flavobacterium psychrophilum generated by standard CLSI test protocols. The MIC values for ten antibiotic agents against Flavobacterium psychrophilum were determined in two laboratories. For five antibiotics, the data sets were of sufficient quality and quantity to allow the setting of valid epidemiological cut-off values. For these agents, the cut-off values, calculated by the application of the statistically based normalized resistance interpretation method, were ≤16 mg L(-1) for erythromycin, ≤2 mg L(-1) for florfenicol, ≤0.025 mg L(-1) for oxolinic acid (OXO), ≤0.125 mg L(-1) for oxytetracycline and ≤20 (1/19) mg L(-1) for trimethoprim/sulphamethoxazole. For ampicillin and amoxicillin, the majority of putative wild-type observations were 'off scale', and therefore, statistically valid cut-off values could not be calculated. For ormetoprim/sulphadimethoxine, the data were excessively diverse and a valid cut-off could not be determined. For flumequine, the putative wild-type data were extremely skewed, and for enrofloxacin, there was inadequate separation in the MIC values for putative wild-type and non-wild-type strains. It is argued that the adoption of OXO as a class representative for the quinolone group would be a valid method of determining susceptibilities to these agents.

  9. Calculating broad neutron resonances in a cut-off Woods-Saxon potential

    NASA Astrophysics Data System (ADS)

    Baran, Á.; Noszály, Cs.; Salamon, P.; Vertse, T.

    2015-07-01

    In a cut-off Woods-Saxon (CWS) potential with realistic depth S -matrix poles being far from the imaginary wave number axis form a sequence where the distances of the consecutive resonances are inversely proportional with the cut-off radius value, which is an unphysical parameter. Other poles lying closer to the imaginary wave number axis might have trajectories with irregular shapes as the depth of the potential increases. Poles being close repel each other, and their repulsion is responsible for the changes of the directions of the corresponding trajectories. The repulsion might cause that certain resonances become antibound and later resonances again when they collide on the imaginary axis. The interaction is extremely sensitive to the cut-off radius value, which is an apparent handicap of the CWS potential.

  10. Mass-number and excitation-energy dependence of the spin cutoff parameter

    SciTech Connect

    Grimes, S. M.; Voinov, A. V.; Massey, T. N.

    2016-07-12

    Here, the spin cutoff parameter determining the nuclear level density spin distribution ρ(J) is defined through the spin projection as < J2z > 1/2 or equivalently for spherical nuclei, (< J(J+1) >/3)1/2. It is needed to divide the total level density into levels as a function of J. To obtain the total level density at the neutron binding energy from the s-wave resonance count, the spin cutoff parameter is also needed. The spin cutoff parameter has been calculated as a function of excitation energy and mass with a super-conducting Hamiltonian. Calculations have been compared with two commonly used semiempirical formulas. A need for further measurements is also observed. Some complications for deformed nuclei are discussed. The quality of spin cut off parameter data derived from isomeric ratio measurement is examined.

  11. Mass-number and excitation-energy dependence of the spin cutoff parameter

    DOE PAGES

    Grimes, S. M.; Voinov, A. V.; Massey, T. N.

    2016-07-12

    Here, the spin cutoff parameter determining the nuclear level density spin distribution ρ(J) is defined through the spin projection as < J2z > 1/2 or equivalently for spherical nuclei, (< J(J+1) >/3)1/2. It is needed to divide the total level density into levels as a function of J. To obtain the total level density at the neutron binding energy from the s-wave resonance count, the spin cutoff parameter is also needed. The spin cutoff parameter has been calculated as a function of excitation energy and mass with a super-conducting Hamiltonian. Calculations have been compared with two commonly used semiempirical formulas.more » A need for further measurements is also observed. Some complications for deformed nuclei are discussed. The quality of spin cut off parameter data derived from isomeric ratio measurement is examined.« less

  12. Quantifying flood duration controls on chute cutoff formation in a wandering gravel-bed river

    NASA Astrophysics Data System (ADS)

    Sawyer, A.; Wilcox, A. C.

    2014-12-01

    Chute cutoffs, which occur when a bypass or "chute" channel incises across a point or braid bar, distribute water and sediment, regulate sinuosity, and create off-channel habitat in wandering gravel-bed rivers. Cutoffs have been hypothesized to occur by progressive migration preparing a bend for cutoff, after which overbank flow events provide a trigger to excavate new channels. This trigger may depend on the magnitude and duration of floods and their associated sediment fluxes. Here we investigated how overbank flow duration impacts cutoff formation in a wandering gravel-bed river. To explore this, we applied a two-dimensional hydrodynamic model to a recently reconstructed reach of the Clark Fork River in western Montana that experienced chute cutoffs during a long-duration flood event in 2011. Hydrographs exceeding bankfull and with varying durations were simulated to constrain the role of overbank flow duration on erosional work in chute cutoff channels. For each magnitude-frequency-duration combination, cumulative excess shear stress (i.e., above the threshold of sediment mobilization) was quantified for in-channel and overbank areas. Locations of shear stress divergence associated with morphological change were identified along chute pathways. Preliminary results suggest that overbank areas containing concentrated flowpaths such as swales follow cumulative excess shear stress curve patterns similar to in-channel areas. This work describes a dynamic system characteristic of wandering gravel-bed rivers in the Pacific Northwest, and has implications for understanding morphodynamic evolution, river restoration targeting off-channel habitat for fish, and geomorphic flow regime management in regulated rivers.

  13. Mechanically robust 39 GHz cut-off frequency graphene field effect transistors on flexible substrates

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Pallecchi, Emiliano; Haque, Samiul; Borini, Stefano; Avramovic, Vanessa; Centeno, Alba; Amaia, Zurutuza; Happy, Henri

    2016-07-01

    Graphene has been regarded as a promising candidate channel material for flexible devices operating at radio-frequency (RF). In this work we fabricated and fully characterized double bottom-gate graphene field effect transistors on flexible polymer substrates for high frequency applications. We report a record high as-measured current gain cut-off frequency (ft) of 39 GHz. The corresponding maximum oscillation frequency (fmax) is 13.5 GHz. These state of the art high frequency performances are stable against bending, with a typical variation of around 10%, for a bending radius of up to 12 mm. To demonstrate the reliability of our devices, we performed a fatigue stress test for RF-GFETs which were dynamically bend tested 1000 times at 1 Hz. The devices are mechanically robust, and performances are stable with typical variations of 15%. Finally we investigate thermal dissipation, which is a critical parameter for flexible electronics. We show that at the optimum polarization the normalized power dissipated by the GFETs is about 0.35 mW μm-2 and that the substrate temperature is around 200 degree centigrade. At a higher power, irreversible degradations of the performances are observed. Our study on state of the art flexible GFETs demonstrates mechanical robustness and stability upon heating, two important elements to assess the potential of GFETs for flexible electronics.Graphene has been regarded as a promising candidate channel material for flexible devices operating at radio-frequency (RF). In this work we fabricated and fully characterized double bottom-gate graphene field effect transistors on flexible polymer substrates for high frequency applications. We report a record high as-measured current gain cut-off frequency (ft) of 39 GHz. The corresponding maximum oscillation frequency (fmax) is 13.5 GHz. These state of the art high frequency performances are stable against bending, with a typical variation of around 10%, for a bending radius of up to 12 mm. To

  14. Cutoff-mesa isolated rib optical waveguide for III-V heterostructure photonic integrated circuits

    DOEpatents

    Vawter, G.A.; Smith, R.E.

    1998-04-28

    A cutoff mesa rib waveguide provides single-mode performance regardless of any deep etches that might be used for electrical isolation between integrated electrooptic devices. Utilizing a principle of a cutoff slab waveguide with an asymmetrical refractive index profile, single mode operation is achievable with a wide range of rib widths and does not require demanding etch depth tolerances. This new waveguide design eliminates reflection effects, or self-interference, commonly seen when conventional rib waveguides are combined with deep isolation etches and thereby reduces high order mode propagation and crosstalk compared to the conventional rib waveguides. 7 figs.

  15. Gyrotron with a sectioned cavity based on excitation of a far-from-cutoff operating mode

    SciTech Connect

    Bandurkin, I. V.; Kalynov, Yu. K.; Osharin, I. V.; Savilov, A. V.

    2016-01-15

    A typical problem of weakly relativistic low-power gyrotrons (especially in the case of operation at high cyclotron harmonics) is the use of long cavities ensuring extremely high diffraction Q-factors for the operating near-cutoff waves. As a result, a great share of the rf power radiated by electrons is spent in Ohmic losses. In this paper, we propose to use a sectioned cavity with π-shifts of the wave phase between sections. In such a cavity, a far-from-cutoff axial mode of the operating cavity having a decreased diffraction Q-factor is excited by the electron beam in a gyrotron-like regime.

  16. Elongation cutoff technique armed with quantum fast multipole method for linear scaling.

    PubMed

    Korchowiec, Jacek; Lewandowski, Jakub; Makowski, Marcin; Gu, Feng Long; Aoki, Yuriko

    2009-11-30

    A linear-scaling implementation of the elongation cutoff technique (ELG/C) that speeds up Hartree-Fock (HF) self-consistent field calculations is presented. The cutoff method avoids the known bottleneck of the conventional HF scheme, that is, diagonalization, because it operates within the low dimension subspace of the whole atomic orbital space. The efficiency of ELG/C is illustrated for two model systems. The obtained results indicate that the ELG/C is a very efficient sparse matrix algebra scheme.

  17. Mach Cutoff Analysis and Results from NASA's Farfield Investigation of No-Boom Thresholds

    NASA Technical Reports Server (NTRS)

    Cliatt, Larry J., II; Hill, Michael A.; Haering, Edward A, Jr.

    2016-01-01

    In support of the ongoing effort by the National Aeronautics and Space Administration (NASA) to bring supersonic commercial travel to the public, the NASA Armstrong Flight Research Center and the NASA Langley Research Center,in partnership with other industry organizations and academia, conducted a flight research experiment to analyze acoustic propagation in the Mach cutoff shadow zone. The effort was conducted in fall of 2012 and named the Farfield Investigation of No-boom Thresholds (FaINT). The test helped to build a data set that will go toward further understanding of the unique acoustic propagation characteristics below Mach cutoff altitude.

  18. Maximizing the yield and cutoff of high-order harmonic generation from plasma plume

    SciTech Connect

    Ganeev, Rashid A.; Elouga Bom, Luc B.; Ozaki, Tsuneyuki; Redkin, Pavel V.

    2007-11-15

    We study high-order harmonic generation (HHG) from various lowly ionized laser plasmas. We study harmonic generation from targets of Al (Z=13) to Bi (Z=83). Varying the wavelength, chirp, and pulse duration of the femtosecond pump laser resulted in the change in the harmonic distribution, cutoff, and conversion efficiency of HHG. We also study the use of doubly charged ions, and resonances for some materials. We were able to obtain high HHG conversion efficiency and harmonic cutoff by implementing the above approaches and by observing the time-resolved spectra of the laser plasma.

  19. Cutoff-mesa isolated rib optical waveguide for III-V heterostructure photonic integrated circuits

    DOEpatents

    Vawter, Gregory A.; Smith, Robert E.

    1998-01-01

    A cutoff mesa rib waveguide provides single-mode performance regardless of any deep etches that might be used for electrical isolation between integrated electrooptic devices. Utilizing a principle of a cutoff slab waveguide with an asymmetrical refractive index profile, single mode operation is achievable with a wide range of rib widths and does not require demanding etch depth tolerances. This new waveguide design eliminates reflection effects, or self-interference, commonly seen when conventional rib waveguides are combined with deep isolation etches and thereby reduces high order mode propagation and crosstalk compared to the conventional rib waveguides.

  20. The Effects of Low- and High-Energy Cutoffs on Solar Flare Microwave and Hard X-Ray Spectra

    NASA Technical Reports Server (NTRS)

    Holman, G. D.; Oegerle, William (Technical Monitor)

    2002-01-01

    Microwave and hard x-ray spectra provide crucial information about energetic electrons and their environment in solar flares. These spectra are becoming better determined with the Owens Valley Solar Array (OVSA) and the recent launch of the Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The proposed Frequency Agile Solar Radiotelescope (FASR) promises even greater advances in radio observations of solar flares. Both microwave and hard x-ray spectra are sensitive to cutoffs in the electron distribution function. The determination of the high-energy cutoff from these spectra establishes the highest electron energies produced by the acceleration mechanism, while determination of the low-energy cutoff is crucial to establishing the total energy in accelerated electrons. This paper will show computations of the effects of both high- and low-energy cutoffs on microwave and hard x-ray spectra. The optically thick portion of a microwave spectrum is enhanced and smoothed by a low-energy cutoff, while a hard x-ray spectrum is flattened below the cutoff energy. A high-energy cutoff steepens the microwave spectrum and increases the wavelength at which the spectrum peaks, while the hard x-ray spectrum begins to steepen at photon energies roughly an order of magnitude below the electron cutoff energy. This work discusses how flare microwave and hard x-ray spectra can be analyzed together to determine these electron cutoff energies. This work is supported in part by the NASA Sun-Earth Connection Program.

  1. Quantum Čerenkov Radiation: Spectral Cutoffs and the Role of Spin and Orbital Angular Momentum

    NASA Astrophysics Data System (ADS)

    Kaminer, Ido; Mutzafi, Maor; Levy, Amir; Harari, Gal; Herzig Sheinfux, Hanan; Skirlo, Scott; Nemirovsky, Jonathan; Joannopoulos, John D.; Segev, Mordechai; Soljačić, Marin

    2016-01-01

    We show that the well-known Čerenkov effect contains new phenomena arising from the quantum nature of charged particles. The Čerenkov transition amplitudes allow coupling between the charged particle and the emitted photon through their orbital angular momentum and spin, by scattering into preferred angles and polarizations. Importantly, the spectral response reveals a discontinuity immediately below a frequency cutoff that can occur in the optical region. Near this cutoff, the intensity of the conventional Čerenkov radiation (ČR) is very small but still finite, while our quantum calculation predicts exactly zero intensity above the cutoff. Below that cutoff, with proper shaping of electron beams (ebeams), we predict that the traditional ČR angle splits into two distinctive cones of photonic shockwaves. One of the shockwaves can move along a backward cone, otherwise considered impossible for conventional ČR in ordinary matter. Our findings are observable for ebeams with realistic parameters, offering new applications including novel quantum optics sources, and opening a new realm for Čerenkov detectors involving the spin and orbital angular momentum of charged particles.

  2. Comment on ''Insensitivity of Hawking radiation to an invariant Planck-scale cutoff''

    SciTech Connect

    Helfer, Adam D.

    2010-05-15

    I point out that the cutoff introduced by Agulloet al.[I. Agullo, J. Navarro-Salas, G. J. Olmo, and ?>L. Parker, Phys. Rev. D 80, 047503 (2009)] has little impact on the trans-Planckian problem as it is usually understood; it excludes only a small fraction of the problematic modes.

  3. A New Regularization Mechanism for the Boltzmann Equation Without Cut-Off

    NASA Astrophysics Data System (ADS)

    Silvestre, Luis

    2016-11-01

    We apply recent results on regularity for general integro-differential equations to derive a priori estimates in Hölder spaces for the space homogeneous Boltzmann equation in the non cut-off case. We also show an a priori estimate in {L^∞} which applies in the space inhomogeneous case as well, provided that the macroscopic quantities remain bounded.

  4. Approximation to cutoffs of higher modes of Rayleigh waves for a layered earth model

    USGS Publications Warehouse

    Xu, Y.; Xia, J.; Miller, R.D.

    2009-01-01

    A cutoff defines the long-period termination of a Rayleigh-wave higher mode and, therefore is a key characteristic of higher mode energy relationship to several material properties of the subsurface. Cutoffs have been used to estimate the shear-wave velocity of an underlying half space of a layered earth model. In this study, we describe a method that replaces the multilayer earth model with a single surface layer overlying the half-space model, accomplished by harmonic averaging of velocities and arithmetic averaging of densities. Using numerical comparisons with theoretical models validates the single-layer approximation. Accuracy of this single-layer approximation is best defined by values of the calculated error in the frequency and phase velocity estimate at a cutoff. Our proposed method is intuitively explained using ray theory. Numerical results indicate that a cutoffs frequency is controlled by the averaged elastic properties within the passing depth of Rayleigh waves and the shear-wave velocity of the underlying half space. ?? Birkh??user Verlag, Basel 2009.

  5. The Search for "Optimal" Cutoff Properties: Fit Index Criteria in Structural Equation Modeling

    ERIC Educational Resources Information Center

    Sivo, Stephen A.; Xitao, Fan; Witta, E. Lea; Willse, John T.

    2006-01-01

    This study is a partial replication of L. Hu and P. M. Bentler's (1999) fit criteria work. The purpose of this study was twofold: (a) to determine whether cut-off values vary according to which model is the true population model for a dataset and (b) to identify which of 13 fit indexes behave optimally by retaining all of the correct models while…

  6. Infinite-Cutoff Renormalization of the Chiral Nucleon-Nucleon Interaction up to N3LO

    NASA Astrophysics Data System (ADS)

    Zeoli, Ch.; Machleidt, R.; Entem, D. R.

    2013-12-01

    Naively, the "best" method of renormalization is the one where a momentum cutoff is taken to infinity while maintaining stable results due to a cutoff-dependent adjustment of counterterms. We have applied this renormalization method in the non-perturbative calculation of phase-shifts for nucleon-nucleon ( NN) scattering using chiral NN potentials up to next-to-next-to-next-to-leading order (N3LO). For lower partial waves, we find that there is either no convergence with increasing order or, if convergence occurs, the results do not always converge to the empirical values. For higher partial waves, we always observe convergence to the empirical phase shifts (except for the 3G5 state). Furthermore, no matter what the order is, one can use only one or no counterterm per partial wave, creating a rather erratic scheme of power counting that does not allow for a systematic order-by-order improvement of the predictions. The conclusion is that infinite-cutoff renormalization is inappropriate for chiral NN interactions, which should not come as a surprise, since the chiral effective field theory (chiral EFT), these interactions are based upon, is designed for momenta below the chiral-symmetry breaking scale of about 1 GeV. Therefore, this value for the hard scale should also be perceived as the appropriate upper limit for the momentum cutoff.

  7. Synchrotron X-ray diagnostics of cutoff shape of nonthermal electron spectrum at young supernova remnants

    NASA Astrophysics Data System (ADS)

    Yamazaki, Ryo; Ohira, Yutaka; Sawada, Makoto; Bamba, Aya

    2014-02-01

    Synchrotron X-rays can be a useful tool to investigate electron acceleration at young supernova remnants (SNRs). At present, since the magnetic field configuration around the shocks of SNRs is uncertain, it is not clear whether electron acceleration is limited by SNR age, synchrotron cooling, or even escape from the acceleration region. We study whether the acceleration mechanism can be constrained by the cutoff shape of the electron spectrum around the maximum energy. We derive analytical formulae of the cutoff shape in each case where the maximum electron energy is determined by SNR age, synchrotron cooling and escape from the shock. They are related to the energy dependence of the electron diffusion coefficient. Next, we discuss whether information on the cutoff shape can be provided by observations in the near future which will simply give the photon indices and the flux ratios in the soft and hard X-ray bands. We find that if the power-law index of the electron spectrum is independently determined by other observations, then we can constrain the cutoff shape by comparing theoretical predictions of the photon indices and/or the flux ratios with observed data which will be measured by NuSTAR and/or ASTRO-H. Such study is helpful in understanding the acceleration mechanism. In particular, it will supply another independent constraint on the magnetic field strength around the shocks of SNRs.

  8. Special nuclear materials cutoff exercise: Issues and lessons learned, Volume 2 of 3: Appendixes A - C

    SciTech Connect

    Libby, R.A.; Davis, C.; Segal, J.E.; Stanbro, W.D.

    1995-08-01

    This document is the 2nd volume of the three volume set from the Special Nuclear Materials Cutoff Exercise held at Hanford in 1994. Volume 2 contains Appendices A-C, with Appendices A and B containing a discussion of the design of the PUREX process and Appendix C containing a discussion of the safeguards measures for the PUREX facility.

  9. How to Set Cutoff Scores for Knowledge Tests Used in Promotion, Training, Certification, and Licensing.

    ERIC Educational Resources Information Center

    Biddle, Richard E.

    1993-01-01

    Suggests a process for setting a cutoff score on knowledge tests for promotion, certification, and licensing: a modified Angoff method, in which a competency estimate is determined by subject matter experts, is combined with analysis of potential impact on any groups protected by the Civil Rights Act. (SK)

  10. Science and Art of Setting Performance Standards and Cutoff Scores in Kinesiology

    ERIC Educational Resources Information Center

    Zhu, Weimo

    2013-01-01

    Setting standards and cutoff scores is essential to any measurement and evaluation practice. Two evaluation frameworks, norm-referenced (NR) and criterion-referenced (CR), have often been used for setting standards. Although setting fitness standards based on the NR evaluation is relatively easy as long as a nationally representative sample can be…

  11. The INTEGRAL high energy cut-off distribution of Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Malizia, Angela; Ubertini, Pietro; Bird, Antony; Bazzano, Angela; Stephen, John; Molina, Manuela; Bassani, Loredana

    We present the primary continuum parameters, the photon index and the high energy cut-off, of Seyfert galaxies extracted from the INTEGRAL complete sample of AGN. We performed a broad band (0.3-100 keV) spectral analysis by fitting simultaneously the soft and hard X-ray spectra obtained by XMM and INTEGRAL/IBIS-Swift/BAT respectively in order to investigate the general properties of these parameters in particular their distribution and mean values. We present the mean photon index for the t type 1 and type 2 objects of the whole sample as well as their mean high energy cut-off. This is the first time that the cut-off energy is constrained in a such large number of AGN. Using the main parameters of the primary continuum, we are able to obtain the actual physical parameters of the Comptonizing region i.e. the plasma temperature kTe the optical depth tau. Finally, with the high S/N spectra starting to come from NuSTAR it will soon be possible to better constrain the cut-off values in many AGN, allowing the determination of more physical models and so to better understand the continuum emission and geometry of the region surrounding black holes.

  12. 76 FR 35378 - Installation and Use of Engine Cut-Off Switches on Recreational Vehicles

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Parts 175 and 183 RIN 1825-AB34 Installation and Use of Engine Cut-Off Switches on Recreational Vehicles Correction Proposed Rule document 2011-14140 was inadvertently published...

  13. Special nuclear materials cutoff exercise: Issues and lessons learned. Volume 3

    SciTech Connect

    Libby, R.A.; Segal, J.E.; Stanbro, W.D.; Davis, C.

    1995-08-01

    This document is appendices D-J for the Special Nuclear Materials Cutoff Exercise: Issues and Lessons Learned. Included are discussions of the US IAEA Treaty, safeguard regulations for nuclear materials, issue sheets for the PUREX process, and the LANL follow up activity for reprocessing nuclear materials.

  14. Detailed river stage mapping and head gradient analysis during meander cutoff in a laboratory river

    NASA Astrophysics Data System (ADS)

    Han, Bangshuai; Endreny, Theodore A.

    2014-02-01

    Analytical models of river evolution predict meander narrowing and elongation which creates sinuosity-driven hyporheic exchange across the meander neck, by decreasing flow distance and increasing head loss. We used a laboratory river table and close range photogrammetry to map and analyze sinuosity as a driver of head gradients and hyporheic exchange during cutoff. The river valley had relatively high slopes (1.8%) and moderately cohesive sediment (10% talc, 90% sand) to facilitate cutoff, and ratios of horizontal to vertical scaling were distorted to achieve dynamic similitude (Re = 3200). Incipient to cutoff, the head gradient across the neck increased due to a narrowing neck, upstream aggradation, and downstream degradation. Longitudinal and transverse river surface slopes around the meander bend increased as the meander approached cutoff. The steep head gradient across the moderately cohesive meander neck generated seepage erosion and scour that formed a low-sinuosity avulsion. Sediment-rich flow in the avulsed channel aggraded the downstream bed and separated the active channel and oxbow lake. The limitation in geometric and dynamic similitude in the river table limits extrapolation to natural rivers, yet river evolution may involve aggradation and degradation induced channel head loss and turnover hyporheic exchange as well as seepage-induced meander neck erosion. Our submillimeter maps of meander morphology and water stage provide data to parameterize river evolution and hyporheic exchange models, and may inform analysis and mapping of field sites.

  15. Accuracy of Body Mass Index Cutoffs for Classifying Obesity in Chilean Children and Adolescents

    PubMed Central

    Gómez-Campos, Rossana; David Langer, Raquel; de Fátima Guimarães, Roseane; Contiero San Martini, Mariana; Cossio-Bolaños, Marco; de Arruda, Miguel; Guerra-Júnior, Gil; Moreira Gonçalves, Ezequiel

    2016-01-01

    Objective: To determine the accuracy of two international Body Mass Index (BMI) cut-offs for classifying obesity compared to the percentage of fat mass (%FM) assessed by Dual-Energy X-ray Absorptiometry (DXA) in a Chilean sample of children and adolescents; Material and Methods: The subjects studied included 280 children and adolescents (125 girls and 155 boys) aged 8 to 17 years. Weight and height were measured. The BMI was calculated. Two international references (IOFT and WHO) were used as cut-off points. The %FM was assessed by DXA. The receiver operating characteristic (ROC) curve was used to assess the performance of BMI in detecting obesity on the basis of %FM; Results: A high correlation was observed between the %FM measured by the DXA and the Z-scores of IOTF and WHO scores in the Chilean adolescents separated by sex (r = 0.78–0.80). Differences occurred in both references (IOFT and WHO) in relation to the criteria (p < 0.001). Both references demonstrated a good ability to predict sensitivity (between 84% and 93%) and specificity (between 83% and 88%) in both sexes of children and adolescents; Conclusions: A high correlation was observed between the Z-score of the BMI with the percentage of fat determined by the DXA. Despite this, the classifications using the different BMI cut-off points showed discrepancies. This suggests that the cut-off points selected to predict obesity in this sample should be viewed with caution. PMID:27164119

  16. The Generalized Regression Discontinuity Design: Using Multiple Assignment Variables and Cutoffs to Estimate Treatment Effects

    ERIC Educational Resources Information Center

    Wong, Vivian C.; Steiner, Peter M.; Cook, Thomas D.

    2009-01-01

    This paper introduces a generalization of the regression-discontinuity design (RDD). Traditionally, RDD is considered in a two-dimensional framework, with a single assignment variable and cutoff. Treatment effects are measured at a single location along the assignment variable. However, this represents a specialized (and straight-forward)…

  17. High sensitivity of p-modes near the acoustic cutoff frequency to solar model parameters

    NASA Technical Reports Server (NTRS)

    Guenther, D. B.

    1991-01-01

    The p-mode frequencies of low l have been calculated for solar models with initial helium mass fraction varying from Y = 0.2753-0.2875. The differences in frequency of the p-modes in the frequency range, 2500-4500 microHz, do not exceed 1-5 microHz among the models. But in the vicinity of the acoustic cutoff frequency, near 5000 microHz the p-mode frequency differences are enhanced by a factor of 4. The enhanced sensitivity of p-modes near the acoustic cutoff frequency was further tested by calculating and comparing p-mode frequencies of low l for two solar models one incorporating the Eddington T-tau relation and the other the Krishna Swamy T-tau relation. Again, it is found that p-modes with frequencies near the acoustic cutoff frequency show a significant increase in sensitivity to the different T-tau relations, compared to lower frequency p-modes. It is noted that frequencies above the acoustic cutoff frequency are complex, hence, cannot be modeled by the adiabatic pulsation code (assumes real eigenfrequencies) used in these calculations.

  18. Construction Foundation Report. Mud Mountain Dam Seepage Control Cutoff Wall, White River, Washington

    DTIC Science & Technology

    1991-08-01

    slickensides, no gouge 8L Primary Blue clay and crushed oxidized gouge in zone 0.2’ to 1.5’ wide. In adit 0.2’ to 0.8’ oxidized gouge 9L Primary 0.2’ to...5’ wide gouge and fractured crushed rock, variable 10L Secondary 0.2’ oxidized gouge An exploration adit was driven along fault 8L on the left canyon...wall. Within the adit , inclination of fault 8L was measured at 32 degrees and the fault walls were found to be highly polished. Fault width varied

  19. Starting the polypill: the use of a single age cut-off in males and females.

    PubMed

    Wald, Nicholas J; Luteijn, Johannes M; Morris, Joan K

    2017-03-01

    Objective Age screening and preventive medication for future myocardial infarction and stroke has been previously described. We aimed to ascertain whether different age cut-offs are needed for males and females. Methods We determined five parameters for each sex according to age cut-off: detection rate (sensitivity), false-positive rate, proportion of the population eligible for treatment with a polypill, proportion who benefit from taking a polypill (simvastatin 20 mg, losartan 25 mg, hydrochlorothiazide 12.5 mg, amlodipine 2.5 mg), and among these, years of life gained without a first myocardial infarction or stroke. Results Approximately one-third benefit, regardless of the age cut-off. For males and females combined, using ages 40 and 80, the detection rates are 98% and 52%, false-positive rates are 51% and 7%, population percentages eligible for treatment are 52% and 7%, and years of life gained without a first myocardial infarction or stroke are 8.4 and 3.6. Using age 50, detection rates are 93% (males) 98% (females), false-positive rates 37% (males) 40% (females), percentage of the population eligible for treatment 38% (males) 41% (females), percentage who benefit 35% (males) 33% (females), and years of life gained without an event 8.5 (males) 7.0 (females). At a given age cut-off, the sex differences are relatively small. Conclusion A single age cut-off can be used for both sexes.

  20. Starting the polypill: the use of a single age cut-off in males and females

    PubMed Central

    Luteijn, Johannes M; Morris, Joan K

    2016-01-01

    Objective Age screening and preventive medication for future myocardial infarction and stroke has been previously described. We aimed to ascertain whether different age cut-offs are needed for males and females. Methods We determined five parameters for each sex according to age cut-off: detection rate (sensitivity), false-positive rate, proportion of the population eligible for treatment with a polypill, proportion who benefit from taking a polypill (simvastatin 20 mg, losartan 25 mg, hydrochlorothiazide 12.5 mg, amlodipine 2.5 mg), and among these, years of life gained without a first myocardial infarction or stroke. Results Approximately one-third benefit, regardless of the age cut-off. For males and females combined, using ages 40 and 80, the detection rates are 98% and 52%, false-positive rates are 51% and 7%, population percentages eligible for treatment are 52% and 7%, and years of life gained without a first myocardial infarction or stroke are 8.4 and 3.6. Using age 50, detection rates are 93% (males) 98% (females), false-positive rates 37% (males) 40% (females), percentage of the population eligible for treatment 38% (males) 41% (females), percentage who benefit 35% (males) 33% (females), and years of life gained without an event 8.5 (males) 7.0 (females). At a given age cut-off, the sex differences are relatively small. Conclusion A single age cut-off can be used for both sexes. PMID:27072544

  1. Multiple Sclerosis Questionnaire for Job Difficulties (MSQ-Job): definition of the cut-off score.

    PubMed

    Schiavolin, Silvia; Giovannetti, Ambra Mara; Leonardi, Matilde; Brenna, Greta; Brambilla, Laura; Confalonieri, Paolo; Frangiamore, Rita; Mantegazza, Renato; Moscatelli, Marco; Clerici, Valentina Torri; Cortese, Francesca; Covelli, Venusia; Ponzio, Michela; Zaratin, Paola; Raggi, Alberto

    2016-05-01

    Multiple Sclerosis (MS) mainly affects people of working age. The Multiple Sclerosis Questionnaire for Job Difficulties (MSQ-Job) was designed to measure difficulties in work-related tasks. Our aim is to define cut-off score of MSQ-Job to identify potential critical situations that might require specific attention. A sample of patients with MS completed the MSQ-Job, WHODAS 2.0 and MSQOL-54 respectively for work difficulties, disability and health-related quality of life (HRQoL) evaluation. K-means Cluster Analysis was used to divide the sample in three groups on the basis of HRQoL and disability. ANOVA test was performed to compare the response pattern between these groups. The cut-off score was defined using the receiver operating characteristic (ROC) curve analyses for MSQ-Job total and count of MSQ-Job items scores ≥3: a score value corresponding to the maximum of the sensitivity-to-specificity ratio was chosen as the cut-off. Out of 180 patients enrolled, twenty were clustered in the higher severity group. The area under the ROC curve was 0.845 for the MSQ-Job total and 0.859 for the count of MSQ-Job items scores ≥3 while the cut-off score was 15.8 for MSQ-Job total and 8 for count of items scored ≥3. We recommend the use of MSQ-Job with this calculation as cut-off for identifying critical situations, e.g. in vocational rehabilitation services, where work-related difficulties have a significant impact in terms of lower quality of life and higher disability.

  2. Defining the cutoff value of MGMT gene promoter methylation and its predictive capacity in glioblastoma.

    PubMed

    Brigliadori, Giovanni; Foca, Flavia; Dall'Agata, Monia; Rengucci, Claudia; Melegari, Elisabetta; Cerasoli, Serenella; Amadori, Dino; Calistri, Daniele; Faedi, Marina

    2016-06-01

    Despite advances in the treatment of glioblastoma (GBM), median survival is 12-15 months. O6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation status is acknowledged as a predictive marker for temozolomide (TMZ) treatment. When MGMT promoter values fall into a "methylated" range, a better response to chemotherapy is expected. However, a cutoff that discriminates between "methylated" and "unmethylated" status has yet to be defined. We aimed to identify the best cutoff value and to find out whether variability in methylation profiles influences the predictive capacity of MGMT promoter methylation. Data from 105 GBM patients treated between 2008 and 2013 were analyzed. MGMT promoter methylation status was determined by analyzing 10 CpG islands by pyrosequencing. Patients were treated with radiotherapy followed by TMZ. MGMT promoter methylation status was classified into unmethylated 0-9 %, methylated 10-29 % and methylated 30-100 %. Statistical analysis showed that an assumed methylation cutoff of 9 % led to an overestimation of responders. All patients in the 10-29 % methylation group relapsed before the 18-month evaluation. Patients with a methylation status ≥30 % showed a median overall survival of 25.2 months compared to 15.2 months in all other patients, confirming this value as the best methylation cutoff. Despite wide variability among individual profiles, single CpG island analysis did not reveal any correlation between single CpG island methylation values and relapse or death. Specific CpG island methylation status did not influence the predictive value of MGMT. The predictive role of MGMT promoter methylation was maintained only with a cutoff value ≥30 %.

  3. Spatial and temporal variability in sedimentation rates associated with cutoff channel infill deposits: Ain River, France

    USGS Publications Warehouse

    Piegay, H.; Hupp, C.R.; Citterio, A.; Dufour, S.; Moulin, B.; Walling, D.E.

    2008-01-01

    Floodplain development is associated with lateral accretion along stable channel geometry. Along shifting rivers, the floodplain sedimentation is more complex because of changes in channel position but also cutoff channel presence, which exhibit specific overflow patterns. In this contribution, the spatial and temporal variability of sedimentation rates in cutoff channel infill deposits is related to channel changes of a shifting gravel bed river (Ain River, France). The sedimentation rates estimated from dendrogeomorphic analysis are compared between and within 14 cutoff channel infills. Detailed analyses along a single channel infill are performed to assess changes in the sedimentation rates through time by analyzing activity profiles of the fallout radionuclides 137Cs and unsupported 210Pb. Sedimentation rates are also compared within the channel infills with rates in other plots located in the adjacent floodplain. Sedimentation rates range between 0.65 and 2.4 cm a -1 over a period of 10 to 40 years. The data provide additional information on the role of distance from the bank, overbank flow frequency, and channel geometry in controlling the sedimentation rate. Channel infills, lower than adjacent floodplains, exhibit higher sedimentation rates and convey overbank sediment farther away within the floodplain. Additionally, channel degradation, aggradation, and bank erosion, which reduce or increase the distance between the main channel and the cutoff channel aquatic zone, affect local overbank flow magnitude and frequency and therefore sedimentation rates, thereby creating a complex mosaic of sedimentation zones within the floodplain and along the cutoff channel infills. Last, the dendrogeomorphic and 137Cs approaches are cross validated for estimating the sedimentation rate within a channel infill. Copyright 2008 by the American Geophysical Union.

  4. THE INTEGRAL HIGH-ENERGY CUT-OFF DISTRIBUTION OF TYPE 1 ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Malizia, A.; Molina, M.; Bassani, L.; Stephen, J. B.; Bazzano, A.; Ubertini, P.; Bird, A. J.

    2014-02-20

    In this Letter we present the primary continuum parameters, the photon index Γ, and the high-energy cut-off E {sub c} of 41 type-1 Seyfert galaxies extracted from the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) complete sample of active galactic nuclei (AGNs). We performed broadband (0.3-100 keV) spectral analysis by simultaneously fitting the soft and hard X-ray spectra obtained by XMM and INTEGRAL/IBIS-Swift/BAT, respectively, in order to investigate the general properties of these parameters, in particular their distribution and mean values. We find a mean photon index of 1.73 with a standard deviation of 0.17 and a mean high-energy cut-off of 128 keV with a standard deviation of 46 keV for the whole sample. This is the first time that the cut-off energy is constrained in such a large number of AGNs. We have 26 measurements of the cut-off, which corresponds to 63% of the entire sample, distributed between 50 and 200 keV. There are a further 11 lower limits mostly below 300 keV. Using the main parameters of the primary continuum, we have been able to obtain the actual physical parameters of the Comptonizing region, i.e., the plasma temperature kT {sub e} from 20 to 100 keV and the optical depth τ < 4. Finally, with the high signal-to-noise ratio spectra starting to come from NuSTAR it will soon be possible to better constrain the cut-off values in many AGNs, allowing the determination of more physical models and thus better understand the continuum emission and geometry of the region surrounding black holes.

  5. How Mechanical Ventilation Measurement, Cutoff and Duration Affect Rapid Shallow Breathing Index Accuracy: A Randomized Trial

    PubMed Central

    Goncalves, Elaine Cristina; Lago, Alessandra Fabiane; Silva, Elaine Caetano; de Almeida, Marcelo Barros; Basile-Filho, Anibal; Gastaldi, Ada Clarice

    2017-01-01

    Background Decreased accuracy of the rapid shallow breathing index (RSBI) can stem from 1) the method used to obtain this index, 2) duration of mechanical ventilation (MV), and 3) the established cutoff point. The objective was to evaluate the values of RSBI determined by three different methods, using distinct MV times and cutoff points. Methods This prospective study included 40 subjects. Before extubation, three different methods were employed to measure RSBI: pressure support ventilator (PSV) (PSV = 5 - 8 cm H2O; positive end-expiratory pressure (PEEP) = 5 cm H2O) (RSBI_MIN), automatic tube compensation (ATC) (PSV = 0, PEEP = 5 cm H2O, and 100% tube compensation) (RSBI_ATC), and disconnected MV (RSBI_SP). The results were analyzed according to the MV period (less than or over 72 h) and to the outcome of extubation (< 72 h, successful and failed; > 72 h successful and failed). The accuracy of each method was determined at different cutoff points (105, 78, and 50 cycles/min/L). Results The RSBI_MIN, RSBI_ATC, and RSBI_SP values in the group < 72 h were 38 ± 18, 45 ± 26 and 55 ± 22; in the group > 72 h, RSBI_SP value was higher than those of RSBI_ATC and RSBI_MIN (78 ± 29, 51 ± 19 and 39 ± 14) (P < 0.001). For patients with MV > 72 h who failed in removing MV, the RSBI_SP was higher (93 ± 28, 58 ± 18 and 41 ± 10) (P < 0.000), with greater accuracy at cutoff of 78. Conclusion RSBI_SP associated with cutoff point < 78 cycles/min/L seems to be the best strategy to identify failed extubation in subjects with MV for over 72 h. PMID:28270888

  6. [Mini Mental State Examination (MMSE): determination of cutoff scores according to age and educational level].

    PubMed

    Solias, A; Skapinakis, P; Degleris, N; Pantoleon, M; Katirtzoglou, E; Politis, A

    2014-01-01

    For the last 38 years, Mini Mental State Examination (MMSE) has been widely used as a dementia screening measure in everyday clinical practice as well as in both cohort and cross-sectional studies. Its validity and reliability for the Greek population has explicitly been documented. However, the effect of age and education on the subject's performance makes it necessary to reckon them in the estimation of the "cutoff score". The purpose of this study is to estimate the prevalence of dementia in Greek population and determine the "cutoff score" by age and education-corrected norms. Cross sectional study of 630 patients older than 55 years, who live independently in Ilion and Helioupolis Municipalities was conducted, 27.3% of the subjects tested in the study were diagnosed with memory disorder according to their MMSE scores and the validation for the Greek population. The effect of age and education to the subjects' performance was statistically significant (p=.000). The use of standard "cutoff score" was not proved to be useful for the personalized interpretation of the results, as documented by the fact that older individuals with lower education had a poorer performance relatively to younger, highly educated subjects. Comparatively to the group age of 55-60 years, the odds ratio after the age of 75 years varies from 2.58 to 4.91. Regarding the variable factor of education, the odds ratio for the first degree education graduates decreases from 1.43 to 3.19 for the third degree education graduates in comparison with the group of illiterates. In conclusion, the use of the "cutoff score" algorithm and the simultaneous estimation of age and education effect on MMSE score may prove useful for the proper evaluation of MMSE performance. According to the age and education of examine candidates in the community and the primary care, we propose the use of the 25th percentile as a more useful cutoff score in order to decrease the false positive results.

  7. The INTEGRAL High-energy Cut-off Distribution of Type 1 Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Malizia, A.; Molina, M.; Bassani, L.; Stephen, J. B.; Bazzano, A.; Ubertini, P.; Bird, A. J.

    2014-02-01

    In this Letter we present the primary continuum parameters, the photon index Γ, and the high-energy cut-off E c of 41 type-1 Seyfert galaxies extracted from the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) complete sample of active galactic nuclei (AGNs). We performed broadband (0.3-100 keV) spectral analysis by simultaneously fitting the soft and hard X-ray spectra obtained by XMM and INTEGRAL/IBIS-Swift/BAT, respectively, in order to investigate the general properties of these parameters, in particular their distribution and mean values. We find a mean photon index of 1.73 with a standard deviation of 0.17 and a mean high-energy cut-off of 128 keV with a standard deviation of 46 keV for the whole sample. This is the first time that the cut-off energy is constrained in such a large number of AGNs. We have 26 measurements of the cut-off, which corresponds to 63% of the entire sample, distributed between 50 and 200 keV. There are a further 11 lower limits mostly below 300 keV. Using the main parameters of the primary continuum, we have been able to obtain the actual physical parameters of the Comptonizing region, i.e., the plasma temperature kT e from 20 to 100 keV and the optical depth τ < 4. Finally, with the high signal-to-noise ratio spectra starting to come from NuSTAR it will soon be possible to better constrain the cut-off values in many AGNs, allowing the determination of more physical models and thus better understand the continuum emission and geometry of the region surrounding black holes.

  8. Proposed Cutoff for Identifying Adult Smokeless Tobacco Users With Urinary Total 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanonol: An Aggregated Analysis of NHANES 2007–2010 Data

    PubMed Central

    Vardavas, Constantine I.; Connolly, Gregory

    2013-01-01

    Introduction: NNAL [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanonol] is a valid biomarker of tobacco use. However; no study has assessed its use in distinguishing current smokeless tobacco (SLT) users from nonusers. Therefore, this study used aggregated data from the 2007–2008 and 2009–2010 waves of the National Health and Nutrition Examination Survey to determine an optimal threshold for identifying SLT users with NNAL. Methods: Optimal urinary total NNAL concentrations for discriminating SLT-only users from nonusers of any tobacco were determined using receiver operating characteristic analysis. Percentage agreement between self-reported SLT use status and NNAL levels was calculated overall and by sociodemographic characteristics. All analyses were weighted and performed with Stata, Version 11, and MedCalc for Windows, Version 9.5.0.0. Results: In total, 264 individuals reported exclusively using SLT (and no other combustible tobacco product) within the past 5 days, whereas 14,824 were self-reported nonusers of any combustible or smokeless tobacco product. The optimal NNAL cutoff point was 34.0 pg/ml, which was associated with a high sensitivity (95.2%), specificity (93.4%), and overall correct classification rate (93.5%). The area under the curve was 98.3% and the corresponding Youden’s Index was 88.7%. There was high agreement between the proposed NNAL cutoff point and self-reported SLT-only use (95.6%) and self-reported SLT nonuse (93.9%). Conclusion: The proposed cutoff point of 34.0 pg/ml had high sensitivity and specificity and may be used by clinicians and researchers to verify or detect recent SLT use. This study also indicated that self-reported SLT use among adults is a reliable measure and has high agreement with biochemical assessment. PMID:23956252

  9. Cutoffs, Norms, and Patterns of Comorbid Difficulties in Children with Developmental Disabilities on the Baby and Infant Screen for Children with aUtIsm Traits (BISCUIT-Part 2)

    ERIC Educational Resources Information Center

    Matson, Johnny L.; Fodstad, Jill C.; Mahan, Sara

    2009-01-01

    Behavioral symptoms of comorbid psychopathology of 651 children 17-37 months of age who were at risk for developmental disabilities were studied using the BISCUIT-Part 2. In Study 1, norms and cutoff scores were established for this new scale on this sample. In Study 2, frequency of response on the 52 items measured was reported. Problems in…

  10. High-Operating-Temperature Barrier Infrared Detector with Tailorable Cutoff Wavelength

    NASA Technical Reports Server (NTRS)

    Ting, David Z.; Hill, Cory, J.; Soibel, Alexander; Bandara, Sumith V.; Gunapala, Sarath D.

    2011-01-01

    A mid-wavelength infrared (MWIR) barrier photodetector is capable of operating at higher temperature than the prevailing MWIR detectors based on InSb. The standard high-operating-temperature barrier infrared detector (HOT-BIRD) is made with an InAsSb infrared absorber that is lattice-matched to a GaSb substrate, and has a cutoff wavelength of approximately 4 microns. To increase the versatility and utility of the HOT-BIRD, it is implemented with IR absorber materials with customizable cutoff wavelengths. The HOT-BIRD can be built with the quaternary alloy GaInAsSb as the absorber, GaAlSbAs as the barrier, on a lattice-matching GaSb substrate. The cutoff wavelength of the GaInAsSb can be tailored by adjusting the alloy composition. To build a HOT-BIRD requires a matching pair of absorber and barrier materials with the following properties: (1) their valence band edges must be approximately the same to allow unimpeded hole flow, while their conduction band edges should have a large difference to form an electron barrier; and (2) the absorber and the barrier must be respectively lattice-matched and closely lattice-matched to the substrate to ensure high material quality and low defect density. To make a HOT-BIRD with cutoff wavelength shorter than 4 microns, a GaInAsSb quaternary alloy was used as the absorber, and a matching GaAlSbAs quaternary alloy as the barrier. By changing the alloy composition, the band gap of the quaternary alloy absorber can be continuously adjusted with cutoff wavelength ranging from 4 microns down to the short wavelength infrared (SWIR). By carefully choosing the alloy composition of the barrier, a HOT-BIRD structure can be formed. With this method, a HOT-BIRD can be made with continuously tailorable cutoff wavelengths from 4 microns down to the SWIR. The HOT-BIRD detector technology is suitable for making very-large-format MWIR/SWIR focal plane arrays that can be operated by passive cooling from low Earth orbit. High-operating temperature

  11. 40 CFR 53.53 - Test for flow rate accuracy, regulation, measurement accuracy, and cut-off.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... measurement accuracy, coefficient of variability measurement accuracy, and the flow rate cut-off function. The... flow measurements are made at intervals not to exceed 5 minutes. The flow rate cut-off test, conducted... definitions. (1) Sample flow rate means the quantitative volumetric flow rate of the air stream caused by...

  12. 40 CFR 53.53 - Test for flow rate accuracy, regulation, measurement accuracy, and cut-off.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... measurement accuracy, coefficient of variability measurement accuracy, and the flow rate cut-off function. The... flow measurements are made at intervals not to exceed 5 minutes. The flow rate cut-off test, conducted... definitions. (1) Sample flow rate means the quantitative volumetric flow rate of the air stream caused by...

  13. 40 CFR 53.53 - Test for flow rate accuracy, regulation, measurement accuracy, and cut-off.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... measurement accuracy, coefficient of variability measurement accuracy, and the flow rate cut-off function. The... flow measurements are made at intervals not to exceed 5 minutes. The flow rate cut-off test, conducted... definitions. (1) Sample flow rate means the quantitative volumetric flow rate of the air stream caused by...

  14. 40 CFR 53.53 - Test for flow rate accuracy, regulation, measurement accuracy, and cut-off.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... measurement accuracy, coefficient of variability measurement accuracy, and the flow rate cut-off function. The... flow measurements are made at intervals not to exceed 5 minutes. The flow rate cut-off test, conducted... definitions. (1) Sample flow rate means the quantitative volumetric flow rate of the air stream caused by...

  15. 40 CFR 53.53 - Test for flow rate accuracy, regulation, measurement accuracy, and cut-off.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... measurement accuracy, coefficient of variability measurement accuracy, and the flow rate cut-off function. The... flow measurements are made at intervals not to exceed 5 minutes. The flow rate cut-off test, conducted... definitions. (1) Sample flow rate means the quantitative volumetric flow rate of the air stream caused by...

  16. Fatty acid ethyl esters in hair as alcohol markers: estimating a reliable cut-off point by evaluation of 1,057 autopsy cases.

    PubMed

    Hastedt, Martin; Bossers, Lydia; Krumbiegel, Franziska; Herre, Sieglinde; Hartwig, Sven

    2013-06-01

    Alcohol abuse is a widespread problem, especially in Western countries. Therefore, it is important to have markers of alcohol consumption with validated cut-off points. For many years research has focused on analysis of hair for alcohol markers, but data on the performance and reliability of cut-off values are still lacking. Evaluating 1,057 cases from 2005 to 2011, included a large sample group for the estimation of an applicable cut-off value when compared to earlier studies on fatty acid ethyl esters (FAEEs) in hair. The FAEEs concentrations in hair, police investigation reports, medical history, and the macroscopic and microscopic alcohol-typical results from autopsy, such as liver, pancreas, and cardiac findings, were taken into account in this study. In 80.2 % of all 1,057 cases pathologic findings that may be related to alcohol abuse were reported. The cases were divided into social drinkers (n = 168), alcohol abusers (n = 502), and cases without information on alcohol use. The median FAEEs concentration in the group of social drinkers was 0.302 ng/mg (range 0.008-14.3 ng/mg). In the group of alcohol abusers a median of 1.346 ng/mg (range 0.010-83.7 ng/mg) was found. Before June 2009 the hair FAEEs test was routinely applied to a proximal hair segment of 0-6 cm, changing to a routinely investigated hair length of 3 cm after 2009, as proposed by the Society of Hair Testing (SoHT). The method showed significant differences between the groups of social drinkers and alcoholics, leading to an improvement in the postmortem detection of alcohol abuse. Nevertheless, the performance of the method was rather poor, with an area under the curve calculated from receiver operating characteristic (ROC curve AUC) of 0.745. The optimum cut-off value for differentiation between social and chronic excessive drinking calculated for hair FAEEs was 1.08 ng/mg, with a sensitivity of 56 % and a specificity of 80 %. In relation to the "Consensus on Alcohol Markers 2012

  17. Mobilization of Floodplain Sediments by Chute Cutoffs on a Large River: Lower Wabash River, Illinois-Indiana

    NASA Astrophysics Data System (ADS)

    Zinger, J. A.; Rhoads, B. L.; Best, J.; Engel, F.; Konsoer, K. M.

    2010-12-01

    Bend cutoffs are a common mechanism of morphologic change in all scales of meandering rivers worldwide. Cutoffs can develop either by progressive migration of an elongated bend onto itself, forming a neck cutoff, or by erosion of a new channel across the neck of a bend, producing a chute cutoff. In contrast to the slow processes of “shaving” of the floodplain by outer bank erosion or formation of neck cutoffs by lateral channel migration, the sudden development of a chute cutoff channel can rapidly introduce a large volume of floodplain sediment into the downstream river channel. Formation of a chute cutoff channel also occurs on much shorter timescales than infilling of the subsequent oxbow lake. The asynchronous nature of such floodplain sediment release and storage resulting from cutoffs has important implications for longer-term floodplain sediment balance and the accurate modeling of floodplain evolution and architecture. In this study, using aerial photography and ground survey, we quantified the quantity of floodplain sediment mobilized by two chute cutoff events on Mackey Bend, a large, elongated meander of the lower Wabash River, IL-IN, located just upstream of the Ohio River confluence. A chute cutoff channel on this bend developed during flooding in June 2008 and was followed by formation of a second cutoff channel in July 2009. Here, we compare the volume of sediment released by these cutoff events to the background flux of sediment generated by lateral migration of the bend in the previous 78 years. Our study also explores the influence of these cutoff events on the morphology of the Wabash-Ohio confluence immediately downstream of the evolving chute cutoff channels. We found that, in just over two years, these cutoffs released c. 3. 6 million cubic meters of floodplain sediment, which is comparable to 4.6% of the annual sediment load of the Mississippi River. According to our calculations, it would take over 60 years of lateral migration of Mackey

  18. Edge plasmons and cut-off behavior of graphene nano-ribbon waveguides

    NASA Astrophysics Data System (ADS)

    Hou, Haowen; Teng, Jinghua; Palacios, Tomás; Chua, Soojin

    2016-07-01

    Graphene nano-ribbon waveguides with ultra-short plasmon wavelength are a promising candidate for nanoscale photonic applications. Graphene edge plasmons are the fundamental and lowest losses mode. Through finite element method, edge plasmons show large effective refractive index and strong field confinement on nanoscale ribbons. The edge plasmons follow a k1/2 dispersion relation. The wavelengths of the edge plasmons and center plasmons differ by a fixed factor. The width of edge plasmon is inversely proportional to wave vector of edge plasmon kedge. Edge defects associate with graphene nano-ribbon induce extra losses and reduce the propagation length. Cut-off width of edge plasmons reduces with increasing frequency. Cut-off width of center plasmon is enlarged by edge component but the enlargement effect diminishing with the increase of kedge. The results are important for the application of graphene plasmon towards ultra-compact photonic devices.

  19. "Cut-off" effect of antioxidants and/or probes of variable lipophilicity in microheterogeneous media.

    PubMed

    Aliaga, Carolina; López de Arbina, Amaia; Rezende, Marcos Caroli

    2016-09-01

    The activities of two hydrophilic (ascorbic acid and Trolox) and two hydrophobic (α-tocopherol and BHT) antioxidants were measured by reaction with a series of 4-alkanoyloxyTEMPO radical probes 1 in buffered (pH 7), aqueous, micellar solutions of reduced Triton-X 100. In all cases, a cut-off effect was observed, in line with previous observations of the same effect for the partitioning of probe series 1 in this medium. These results support an interpretation of the cut-off effect in food emulsions, based on the "amphiphobic" nature of either the antioxidants or probes: competition between two molecular moieties, for the micellar hydrophobic core, tends to expose a reacting fragment differently to a more hydrophilic microenvironment, as the probe or antioxidant hydrophobicity increases.

  20. 13 micron cutoff HgCdTe detector arrays for space and ground-based astronomy

    NASA Astrophysics Data System (ADS)

    McMurtry, Craig W.; Cabrera, Mario S.; Dorn, Meghan L.; Pipher, Judith L.; Forrest, William J.

    2016-07-01

    With the recent success of our development of 10 micron HgCdTe infrared (IR) detector arrays,1,2 we have used what we learned and extended the cutoff wavelength to 13 microns. These 13 micron HgCdTe detector arrays can operate at higher temperatures than Si:As, e.g. in a properly designed spacecraft with passive cooling, the 13 micron IR array will work well at temperatures around 30K. We present the initial measurements of dark current, noise and quantum efficiency for the first deliveries of 13 micron HgCdTe detector arrays from Teledyne Imaging Sensors. We also discuss our plans to develop 15 micron cutoff HgCdTe detector arrays which would facilitate the detection of the broad CO2 absorption feature in the atmospheres of exoplanets, particularly those in the habitable zone of their host star.

  1. Scanning Superfluid-Turbulence Cascade by its Low-Temperature Cutoff

    SciTech Connect

    Kozik, Evgeny; Svistunov, Boris

    2008-05-16

    On the basis of a recently proposed scenario of the transformation of the Kolmogorov cascade into the Kelvin-wave cascade, we develop a theory of low-temperature cutoff. The theory predicts a specific behavior of the quantized vortex line density, L, controlled by the frictional coefficient, {alpha}(T)<<1, responsible for the cutoff. The curve ln L(ln{alpha}) is found to directly reflect the structure of the cascade, revealing four qualitatively distinct wave number regions. Excellent agreement with a recent experiment by Walmsley et al. [Phys. Rev. Lett. 99, 265302 (2007)]--in which L(T) has been measured down to T{approx}0.08 K--implies that the scenario of low-temperature superfluid turbulence is now experimentally validated and allows to quantify the Kelvin-wave cascade spectrum.

  2. Implication of the Observable Spectral Cutoff Energy Evolution in XTE J1550-564

    NASA Technical Reports Server (NTRS)

    Titarchuk, Lev; Shaposhnikov, Nikolai

    2010-01-01

    The physical mechanisms responsible for production of the non-thermal emission in accreting black holes should be imprinted in the observational appearances of the power law tails in the X-ray spectra from these objects. Variety of spectral states observed from galactic black hole binaries by it Rossi X-ray Timing Explorer (RXTE) allow examination of the photon upscattering under different accretion regimes. We revisit of RXTE data collected from the black hole X-ray binary XTE J1550-564 during two periods of X-ray activity in 1998 and 2000 focusing on the behavior of the high energy cutoff of the power law part of the spectrum. For the 1998 outburst the Iran- sition from the low-hard state to the intermediate state was accompanied by a gradual decrease in the cutoff energy which then showed a sharp reversal to a clear increasing trend during the further evolution towards the very high and high-soft states. However, the 2000 outburst showed only the decreasing part of this pattern. Notably, the photon indexes corresponding to the cutoff increase for the 1998 event are much higher than the index values reached during the 2000 rise transition. We attribute this difference in the cutoff' energy behav- for to the different partial contributions of the thermal and non-thermal (bulk motion) Comptonization in photon upscattering. Namely, during the 1998 event the higher accretion rate presumably provided more cooling to the Comptonizing media and thus reducing the effectiveness of the thermal upscattering process. Under these conditions the bulk motion takes a leading role in boosting the input soft photons. Monte Carlo simulations of the The physical mechanisms responsible for production of the non-thermal emission in accreting black holes should be imprinted in the observational apperances of the power law tails in the X-ray spectra from these objects. Variety of spectral states observed from galactic black hole binaries by it Rossi X-ray Timing Explorer (RXTE) allow

  3. Set up of cutoff thresholds for kinship determination using SNP loci.

    PubMed

    Cho, Sohee; Shin, Eun Soon; Yu, Hyung Jin; Lee, Ji Hyun; Seo, Hee Jin; Kim, Moon Young; Lee, Soong Deok

    2017-03-08

    The usefulness of single nucleotide polymorphism (SNP) loci for kinship testing has been demonstrated in many case works, and suggested as a promising marker for relationship identification. For interpreting results based on the calculation of the likelihood ratio (LR) in kinship testing, it is important to prepare cutoffs for respective relatives which are dependent on genetic relatedness. For this, analysis using true pedigree data is significant and reliable as it reflects the actual frequencies of markers in the population. In this study, the kinship index was explored through 1209 parent-child pairs, 1373 full sibling pairs, and 247 uncle-nephew pairs using 136 SNP loci. The cutoffs for LR were set up using different numbers of SNP loci with accuracy, sensitivity, and specificity. It is expected that this study can support the application of SNP loci-based kinship testing for various relationships.

  4. Evolution of cutoffs across meander necks in Powder River, Montana, USA

    USGS Publications Warehouse

    Gay, G.R.; Gay, H.H.; Gay, W.H.; Martinson, H.A.; Meade, R.H.; Moody, J.A.

    1998-01-01

    Over a period of several decades, gullies have been observed in various stages of forming, growing and completing the cutoff of meander necks in Powder River. During one episode of overbank flow, water flowing over the down-stream bank of the neck forms a headctu. The headcut migrates up-valley, forming a gully in its wake, until it has traversed the entire neck, cutting off the meander. The river then follows the course of the gully, which is subsequently enlarged as the river develops its new channel. The complete process usually requires several episodes of high water: in only one of the five cases described herein was a meander cutoff initiated and completed during a single large flood.

  5. Shift in the velocity of a front due to a cutoff

    NASA Astrophysics Data System (ADS)

    Brunet, Eric; Derrida, Bernard

    1997-09-01

    We consider the effect of a small cutoff ɛ on the velocity of a traveling wave in one dimension. Simulations done over more than ten orders of magnitude as well as a simple theoretical argument indicate that the effect of the cutoff ɛ is to select a single velocity that converges when ɛ-->0 to the one predicted by the marginal stability argument. For small ɛ, the shift in velocity has the form K(lnɛ)-2 and our prediction for the constant K agrees very well with the results of our simulations. A very similar logarithmic shift appears in more complicated situations, in particular in finite-size effects of some microscopic stochastic systems. Our theoretical approach can also be extended to give a simple way of deriving the shift in position due to initial conditions in the Fisher-Kolmogorov or similar equations.

  6. Synthesis of Two-Color Laser Pulses for the Harmonic Cutoff Extension

    NASA Astrophysics Data System (ADS)

    Wang, Guo-Li; Zhou, Li-Hua; Zhao, Song-Feng; Zhou, Xiao-Xin

    2016-05-01

    Increasing simultaneously both the cutoff energy and efficiency is a big challenge to all applications of high-order harmonic generation (HHG). For this purpose, the shaping of the waveform of driving pulse is an alternative approach. Here, we show that the harmonic cutoff can be extended by about two times without reducing harmonic yield after considering macroscopic propagation effects, by adopting a practical way to synthesize two-color fields with fixed energy. Our results, combined with the experimental techniques, show the great potential of HHG as a tabletop light source. Supported by the National Natural Science Foundation of China under Grant Nos. 11264036, 11164025, 11364038, the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20116203120001, and the Basic Scientific Research Foundation for Institution of Higher Learning of Gansu Province

  7. Boundary value problem for the solution of magnetic cutoff rigidities and some special applications

    NASA Technical Reports Server (NTRS)

    Edmonds, Larry

    1987-01-01

    Since a planet's magnetic field can sometimes provide a spacecraft with some protection against cosmic ray and solar flare particles, it is important to be able to quantify this protection. This is done by calculating cutoff rigidities. An alternate to the conventional method (particle trajectory tracing) is introduced, which is to treat the problem as a boundary value problem. In this approach trajectory tracing is only needed to supply boundary conditions. In some special cases, trajectory tracing is not needed at all because the problem can be solved analytically. A differential equation governing cutoff rigidities is derived for static magnetic fields. The presense of solid objects, which can block a trajectory and other force fields are not included. A few qualititative comments, on existence and uniqueness of solutions, are made which may be useful when deciding how the boundary conditions should be set up. Also included are topics on axially symmetric fields.

  8. Measurement and interpretation of current transmission in a crossed-field diode below cutoff

    SciTech Connect

    Vanderberg, B.H.; Eninger, J.E.

    1997-02-01

    Measurements on the current-voltage-magnetic field characteristics of a space-charge-limited cylindrical cross-field diode below cutoff are presented. The measured current is found to be lower than predicted by simple cold-fluid theory. This reduction combined with observed oscillations in the current can be explained by secondary electron emission from the anode, leading to an increase of space charge in the diode. {copyright} {ital 1997 American Institute of Physics.}

  9. Determination of Cutoff of ELISA and Immunofluorescence Assay for Scrub Typhus

    PubMed Central

    Gupta, Nitin; Chaudhry, Rama; Thakur, Chandan Kumar

    2016-01-01

    Background: The most common method employed for diagnosis of scrub typhus is serology. It is widely known that demonstration of ≥4-fold rise in titers of antibody in paired sera is required for diagnosis. However, for guidance of initial treatment, there is a need for rapid diagnosis at the time of admission. Therefore, there is a need for standardized region specific cutoff titers at the time of admission. Materials and Methods: A total of 258 patients of all age groups with clinically suspected scrub typhus over a period of 24 months (October 2013-October 2015) were enrolled. Serum samples of these patients were subjected to immunofluorescent antibody (IFA) for immunoglobulin M (IgM) (Fuller Labs, USA) with dilutions of 1:64, 1:128, 1:256, and 1:512. Serum samples of all 258 patients were subjected to IgM ELISA (Inbios Inc., USA). Any patient with response to antibiotics within 48 h accompanied by either presence of an eschar or positivity by polymerase chain reaction was taken as positive. Receiver operating characteristic (ROC) curve was drawn to generate cutoff for these tests. Results: A total of 20 patients were diagnosed as cases of scrub typhus. The ROC curve analysis revealed a cutoff optical density value of 0.87 with sensitivity and specificity of 100% and 94.12%, respectively. ROC curve analysis of IFA revealed sensitivity and specificity of 100% and 93.5%, respectively at 1:64 dilution. Conclusion: Considering cost constraints, centers in and around New Delhi region can use the cutoffs we determined for the diagnosis of scrub typhus. PMID:27621559

  10. Solutions to the 1d Klein Gordon equation with cut-off Coulomb potentials

    NASA Astrophysics Data System (ADS)

    Hall, Richard L.

    2007-12-01

    In a recent paper by Barton [G. Barton, J. Phys. A: Math. Gen. 40 (2007) 1011], the 1-dimensional Klein Gordon equation was solved analytically for the non-singular Coulomb-like potential V(|x|)=-α/(|x|+a). In the present Letter, these results are completely confirmed by a numerical formulation that also allows a solution for an alternative cut-off Coulomb potential V(|x|)=-α/|x|, |x|>a, and otherwise V(|x|)=-α/a.

  11. STS-47 Pilot Brown on OV-105's flight deck ten minutes after SSME cutoff

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-47 Pilot Curtis L. Brown, Jr, is photographed at Endeavour's, Orbiter Vehicle (OV) 105's, pilot station about ten minutes after space shuttle main engine (SSME) cutoff on launch day. Brown smiles from inside the launch and entry suit (LES) and launch and entry helmet (LEH). In the background are the flight mirror assembly silhouetted against forward window W5, control panels, and a checklist.

  12. Low-Cutoff, High-Pass Digital Filtering of Neural Signals

    NASA Technical Reports Server (NTRS)

    Mojarradi,Mohammad; Johnson, Travis; Ortiz, Monico; Cunningham, Thomas; Andersen, Richard

    2004-01-01

    The figure depicts the major functional blocks of a system, now undergoing development, for conditioning neural signals acquired by electrodes implanted in a brain. The overall functions to be performed by this system can be summarized as preamplification, multiplexing, digitization, and high-pass filtering. Other systems under development for recording neural signals typically contain resistor-capacitor analog low-pass filters characterized by cutoff frequencies in the vicinity of 100 Hz. In the application for which this system is being developed, there is a requirement for a cutoff frequency of 5 Hz. Because the resistors needed to obtain such a low cutoff frequency would be impractically large, it was decided to perform low-pass filtering by use of digital rather than analog circuitry. In addition, it was decided to timemultiplex the digitized signals from the multiple input channels into a single stream of data in a single output channel. The signal in each input channel is first processed by a preamplifier having a voltage gain of approximately 50. Embedded in each preamplifier is a low-pass anti-aliasing filter having a cutoff frequency of approximately 10 kHz. The anti-aliasing filters make it possible to couple the outputs of the preamplifiers to the input ports of a multiplexer. The output of the multiplexer is a single stream of time-multiplexed samples of analog signals. This stream is processed by a main differential amplifier, the output of which is sent to an analog-to-digital converter (ADC). The output of the ADC is sent to a digital signal processor (DSP).

  13. Cutoff radius effect of the isotropic periodic sum method in homogeneous system. II. Water.

    PubMed

    Takahashi, Kazuaki; Narumi, Tetsu; Yasuoka, Kenji

    2010-07-07

    Molecular dynamics simulation has been applied for water to compare the isotropic periodic sum (IPS) method [X. Wu and B. R. Brooks, J. Chem. Phys. 122, 044107 (2005)] with the Ewald sum based on the diffusion coefficient and liquid structure. The IPS method gives a good estimation for the self-diffusion coefficient at a cutoff radius, r(c), greater than 2.2 nm; however, the radial distribution function g(r) has a notable deviation. The peak of this deviation appears at specific intermolecular distances which are near each cutoff radius and decrease in proportion to the inverse of the cube of r(c). Thus the deviation becomes insignificant (less than 1%) at r(c) greater than 2.2 nm. The distance dependent Kirkwood factor G(k)(r) was also calculated, and since the truncation of a long-range interaction of the cutofflike method (such as cutoff with or without the switch function and the reaction field) shows serious shortcomings for dipole-dipole correlations in bulk water systems, this was observed by comparing the shape to that of the Ewald sum [Y. Yonetani, J. Chem. Phys. 124, 204501 (2006); D. van der Spoel and P. J. van Maaren, J. Chem. Theory Comput. 2, 1 (2006)]. The G(k)(r) of cutofflike method greatly deviate from that of the Ewald sum. However, the discrepancy of G(k)(r) for the IPS method was found to be much less than that of other typical cutofflike methods. In conclusion, the IPS method is an adequately accurate technique for estimating transport coefficients and the liquid structure of water in a homogeneous system at long cutoff distances.

  14. Super-radiant effects in electron oscillators with near-cutoff operating waves

    SciTech Connect

    Bandurkin, I. V.; Savilov, A. V.

    2015-06-15

    Super-radiant regimes in electron oscillators can be attractive for applications requiring powerful and relatively short pulses of microwave radiation, since the peak power of the super-radiant pulse can exceed the power of the operating electron beam. In this paper, possibilities for realization of the super-radiant regimes are studied in various schemes of electron oscillators based on excitation of near-cutoff operating waves (gyrotron and orotron)

  15. Measurement and interpretation of current transmission in a crossed-field diode below cutoff

    NASA Astrophysics Data System (ADS)

    Vanderberg, Bo H.; Eninger, Jan E.

    1997-02-01

    Measurements on the current-voltage-magnetic field characteristics of a space-charge-limited cylindrical cross-field diode below cutoff are presented. The measured current is found to be lower than predicted by simple cold-fluid theory. This reduction combined with observed oscillations in the current can be explained by secondary electron emission from the anode, leading to an increase of space charge in the diode.

  16. Optimization of the cutoff value for a commercial anti-dengue virus IgG immunoassay.

    PubMed

    Marrero-Santos, Karla M; Beltrán, Manuela; Carrión-Lebrón, Jessica; Sanchez-Vegas, Carolina; Hamer, Davidson H; Barnett, Elizabeth D; Santiago, Luis M; Hunsperger, Elizabeth A

    2013-03-01

    A commercial anti-dengue virus (anti-DENV) indirect IgG enzyme-linked immunosorbent assay (ELISA) for serological diagnosis was evaluated for its utility in determining previous DENV exposure in U.S. travelers. The Boston Area Travel Medicine Network clinics used Focus Diagnostics anti-DENV IgG ELISA to measure anti-DENV IgG antibodies in 591 pretravel specimens from U.S. residents who had traveled to countries where dengue is endemic. When using the manufacturer's index cutoff value for this ELISA, false-positive results were observed that overestimated the perceived past DENV exposure in U.S. travelers. Validation of 121 of these anti-DENV IgG results by plaque reduction neutralization test (PRNT) was used for receiver operating characteristic (ROC) curve optimization of the index cutoff value from 1 to 3.0, improving the specificity of the anti-DENV IgG ELISA from 24% to 95.7%. Additionally, previous vaccination with yellow fever virus contributed to 52.8% of the false-positive rate in the anti-DENV IgG ELISA results. Optimization of the cutoff value of the anti-DENV IgG ELISA provided better interpretation and confidence in the results and eliminated the need for confirmation by PRNT. The travel history of U.S. travelers was also useful for categorizing these travelers into groups for analysis of previous DENV exposure.

  17. Estimating the temporal cutoff-rigidity variations and their implication on manned space missions

    NASA Astrophysics Data System (ADS)

    Herbst, K.; Labrenz, J.; Kopp, A.; Heber, B.; Burmeister, S.; Berger, T.

    2014-12-01

    Using the PLANETOCOSMICS code the vertical cutoff rigidity or equivalently the minimum energy a particle must have in order to reach a given location on Earth is calculated. The program allows investigations that depend on the Earth's magnetic field strength and geometry as a function of time. Today it is well known that the magnetic field is the subject of temporal variations on long as well as short time-scales which reflects itself, e.g., in the global vertical cutoff-rigidity distribution at 20 km altitude (see Herbst et al., 2013). Focusing on the changes during the era of manned space missions (1961-2014) we extend our analysis of the vertical cutoff rigidity variations to about 450 km i.e. to the International Space Station (ISS) orbit. The outcome of this analysis will be compared to measurements of the DOSimetry TELescope (DOSTEL), an instrument that has been operational for several time periods onboard the ISS, allowing to determine the response function of the instrument. Using the Force-Field parameter derived from neutron monitors (see Usoskin et al., 2011) we will present maps of DOSTEL measurements for more than 50 years that are caused by galactic cosmic ray variations along hypothetical ISS orbits.

  18. Risk preferences: consequences for test and treatment thresholds and optimal cutoffs.

    PubMed

    Felder, Stefan; Mayrhofer, Thomas

    2014-01-01

    Risk attitudes include risk aversion as well as higher-order risk preferences such as prudence and temperance. This article analyzes the effects of such preferences on medical test and treatment decisions, represented either by test and treatment thresholds or-when the test result is not given-by optimal cutoff values for diagnostic tests. For a risk-averse decision maker, effective treatment is a risk-reducing strategy since it prevents the low health outcome of forgoing treatment in the sick state. Compared with risk neutrality, risk aversion thus lowers both the test and the treatment threshold and decreases the optimal test cutoff value. Risk vulnerability, which combines risk aversion, prudence, and temperance, is relevant if there is a comorbidity risk: thresholds and optimal cutoff values decrease even more. Since common utility functions imply risk vulnerability, our findings suggest that diagnostics in low prevalence settings (e.g., screening) may be considered more beneficial when risk preferences are taken into account.

  19. Effective meson masses in nuclear matter based on a cutoff field theory

    SciTech Connect

    Nakano, M.; Noda, N.; Mitsumori, T.; Koide, K.; Kouno, H.; Hasegawa, A.

    1997-02-01

    Effective masses of {sigma}, {omega}, {pi}, and {rho} mesons in nuclear matter are calculated based on a cutoff field theory. Instead of the traditional density-Feynman representation, we adopt the particle-hole-antiparticle representation for nuclear propagators so that unphysical components are not included in the meson self-energies. For an estimation of the contribution from the divergent particle-antiparticle excitations, i.e., vacuum polarization in nuclear matter, the idea of the renormalization group method is adopted. In this cutoff field theory, all the counterterms are finite and calculated numerically. It is shown that the predicted meson masses converge even if the cutoff {Lambda} is changed as long as {Lambda} is sufficiently large and that the prescription works well also for so-called nonrenormalized mesons such as {pi} and {rho}. According to this method, it is concluded that meson masses in nuclear matter have a weak dependence on the baryon density. {copyright} {ital 1997} {ital The American Physical Society}

  20. Evaluation of Novel Large Cut-Off Ultrafiltration Membranes for Adenovirus Serotype 5 (Ad5) Concentration

    PubMed Central

    Peixoto, Cristina; Roederstein, Susanne; Schleuss, Tobias; Alves, Paula M.; Mota, José P. B.; Carrondo, Manuel J. T.

    2014-01-01

    The purification of virus particles and viral vectors for vaccine and gene therapy applications is gaining increasing importance in order to deliver a fast, efficient, and reliable production process. Ultrafiltration (UF) is a widely employed unit operation in bioprocessing and its use is present in several steps of the downstream purification train of biopharmaceuticals. However, to date few studies have thoroughly investigated the performance of several membrane materials and cut-offs for virus concentration/diafiltration. The present study aimed at developing a novel class of UF cassettes for virus concentration/diafiltration. A detailed study was conducted to evaluate the effects of (i) membrane materials, namely polyethersulfone (PES), regenerated cellulose (RC), and highly cross-linked RC (xRC), (ii) nominal cut-off, and (iii) UF device geometry at different production scales. The results indicate that the xRC cassettes with a cut-off of approximately 500 kDa are able to achieve a 10-fold concentration factor with 100% recovery of particles with a process time twice as fast as that of a commercially available hollow fiber. DNA and host cell protein clearances, as well as hydraulic permeability and fouling behavior, were also assessed. PMID:25546428

  1. Clustered star formation as a natural explanation for the Halpha cut-off in disk galaxies.

    PubMed

    Pflamm-Altenburg, Jan; Kroupa, Pavel

    2008-10-02

    The rate of star formation in a galaxy is often determined by the observation of emission in the Halpha line, which is related to the presence of short-lived massive stars. Disk galaxies show a strong cut-off in Halpha radiation at a certain galactocentric distance, which has led to the conclusion that star formation is suppressed in the outer regions of disk galaxies. This is seemingly in contradiction to recent observations in the ultraviolet which imply that disk galaxies have star formation beyond the Halpha cut-off, and that the star-formation-rate surface density is linearly related to the underlying gas surface density, which is a shallower relationship than that derived from Halpha luminosities. In a galaxy-wide formulation, the clustered nature of star formation has recently led to the insight that the total galactic Halpha luminosity is nonlinearly related to the galaxy-wide star formation rate. Here we show that a local formulation of the concept of clustered star formation naturally leads to a steeper radial decrease in the Halpha surface luminosity than in the star-formation-rate surface density, in quantitative agreement with the observations, and that the observed Halpha cut-off arises naturally.

  2. Is it all about cutoffs? Can DIC scores predict bleeding in APL?

    PubMed

    Chang, Hung

    2013-01-01

    Predicting outcome with a scoring system should be interpreted with caution. In the application of the disseminated intravascular coagulation (DIC) scoring system, a key point is to use well-established cutoff values for the variables. In the article by Mitrovic et al., activated partial thromboplastin time was presented by seconds, while prothrombin time (PT) was expressed as percentage. Such expressions appear confusing and contradictory. In the DIC scoring system, scoring of PT is determined by prolongation in seconds. I cannot see the reason to use the percentage of PT in this article. Furthermore, the PT cutoff was defined as 50%, which may be entirely arbitrary. We had conducted an investigation in our hospital cohort. We had analyzed our cohort by the chi-square method to determine the correlation between DIC scores and bleeding events. We found no relationship between scores and events of bleeding or fatal bleeding. However, reanalysis using a cutoff DIC ≧6 revealed a marginally significant difference in bleeding risk between high-score and low-score patients (P = 0.046). The difference was insignificant for life-threatening bleeding. While our experience appears to support authors' conclusion that DIC score ≧6 is associated with bleeding in acute promyelocytic leukemia patients, we remain skeptical in regard to such manipulations. We believe subsequent studies on a large-scale basis or more accumulated data critically reviewed by experts are needed to shed lights on this important issue.

  3. Capacity, cutoff rate, and coding for a direct-detection optical channel

    NASA Technical Reports Server (NTRS)

    Massey, J. L.

    1980-01-01

    It is shown that Pierce's pulse position modulation scheme with 2 to the L pulse positions used on a self-noise-limited direct detection optical communication channel results in a 2 to the L-ary erasure channel that is equivalent to the parallel combination of L completely correlated binary erasure channels. The capacity of the full channel is the sum of the capacities of the component channels, but the cutoff rate of the full channel is shown to be much smaller than the sum of the cutoff rates. An interpretation of the cutoff rate is given that suggests a complexity advantage in coding separately on the component channels. It is shown that if short-constraint-length convolutional codes with Viterbi decoders are used on the component channels, then the performance and complexity compare favorably with the Reed-Solomon coding system proposed by McEliece for the full channel. The reasons for this unexpectedly fine performance by the convolutional code system are explored in detail, as are various facets of the channel structure.

  4. Optimal waist circumference cutoff values for the diagnosis of abdominal obesity in korean adults.

    PubMed

    Yoon, Yeong Sook; Oh, Sang Woo

    2014-12-29

    Abdominal obesity is associated closely with insulin resistance, diabetes, and cardiovascular disease. Waist circumference (WC) is a useful surrogate marker commonly used for abdominal adiposity. The determination of WC cutoff levels is important in the prevention and treatment of obesity, type 2 diabetes, and related cardiovascular diseases. Recent epidemiological evidence suggested that appropriate optimal cutoffs for Koreans ranged over 80 to 89.8 cm in males and 76.1 to 86.5 cm in females. We analyzed the data from two large cohorts using receiver operating characteristic curve analysis with the incidences of diabetes, hypertension, dyslipidemia, cerebrovascular disease, myocardial infarct, angina, coronary artery disease, and multiple metabolic risk factors as outcome variables. Optimal WC cutoff points for Koreans were 85 cm in males and 80 cm in females. However, considering the prevalence of abdominal obesity and the health costs for its prevention and management, 90 cm in males and 85 cm in females are probably more appropriate thresholds for abdominal obesity. These values may be modified once better research is performed through prospective studies using representative populations, common health outcomes, and proper analytical approaches.

  5. Captures, Cutoffs, and Autogenic Drainage Basin Reorganization from Bedrock River Meandering in the Oregon Coast Range

    NASA Astrophysics Data System (ADS)

    Johnson, K. N.; Finnegan, N. J.

    2015-12-01

    Meandering bedrock channels in the Oregon Coast Range (OCR), USA, have lateral migration rates far in excess of vertical incision rates. Consequently, the sweeping of trunk streams through this landscape can locally exert a much stronger influence on tributary channel long profiles than far-field tectonic forcing of base-level. Here, we use LiDAR-data to explore the influence of lateral channel mobility on the evolution of tributaries to the Smith River, in the OCR. We focus on two processes that dramatically and instantaneously change tributary long profiles: 1) Capture of tributaries by growing meander bends, and 2) Meander bend neck cutoffs on the main-stem that leave tributaries disconnected from base-level lowering. We focus on these two types of events because they provide clear examples of autogenic drivers of landscape disequilibrium at the sub-watershed scale in a landscape that is commonly argued to reflect steady tectonic forcing of base-level. We show that tributary streams are significantly more likely to flow into the leading edge of meander bends, testifying to the repeated capture of tributaries by growing bends. Examples of eminent captures by migrating bends, and examples with large knick points along recently captured tributaries suggest that the autogenic capture of tributaries by growing bends is a fundamental cause of transience in tributary channels in this landscape. To demonstrate the influence of the process of meander bend neck cutoff on tributary long profile evolution, we compare the long profiles of 34 tributaries that were hung above the main-stem of the Smith River following neck cutoff events. These stagnated tributary channels typically exhibit large convexities that record ongoing lowering of the trunk stream. Measured heights of these hanging tributaries implies that the timescale of adjustment for tributaries following cutoff events is ~ 105-106 years. The timescale of adjustment of tributary channels following meander cutoff

  6. Utilization of a detection level of 25ng/mL for cannabinoids in urine using a CEDIA THCPLUS immunoassay: application of this cut-off to urines of school children.

    PubMed

    Madhavaram, Hima; Couch, Ronald A F

    2010-05-20

    Cannabis is the most widely used illicit drug in New Zealand. About 4 years ago schools in New Zealand began introducing drug programmes in order ascertain a pupil's likely cannabinoid use. Our toxicology laboratory screened such specimens for the presence of cannabinoids, using CEDIA immunoassay, at a cut-off of 50ng/mL as directed by the AS/NZS 4308:2001 standard. However, the consequent result that we reported, as not detected (<50ng/mL), in many cases did not parallel the pupil's confessed cannabis use. Our laboratory has therefore used a lower cut-off of 25ng/mL, by this immunoassay. We use this cut-off only for non-evidential analyses. Stored specimens were analysed over two time periods. Initially 2359 urine samples were screened for cannabinoids. 130 of these specimens had a value between 25 and 49ng/mL and 60 of this group were randomly selected for confirmation by GC-MS. In all the 60 specimens, the presence of THCCOOH was confirmed. A further 760 specimens were collected over a later time period. Of these, 48 specimens had an immunoassay value of 25-49ng/mL and all 48 specimens were confirmed positive for THCCOOH by GC-MS. This study indicates that the CEDIA THCPLUS immunoassay can be used to screen for the presence of urinary cannabinoids using a 25ng/mL cut-off. Use of such a cut-off will limit the occurrence of false negative cannabinoid screening results. For school children a lower cut-off may be important, as consequent remedial action, following a positive immunoassay result, may limit the adverse outcomes such as dependence and impairment of achievements as suggested in a New Zealand study by Fergusson and Joseph.

  7. Flow and sediment processes in a cutoff meander of the Danube Delta during 100-year recurrent flood

    NASA Astrophysics Data System (ADS)

    Jugaru Tiron, L.; Le Coz, J.; Provansal, M.; Dutu, F.

    2009-04-01

    River training operations, such as meander cutoff, initiated for navigational purposes often lead to dramatic changes in the streamwise profiles (Hooke, 1986, Kesel, 2003; Kiss et al., 2007). Meander correction affects both the hydraulic and morphodynamical behavior of the modified branches that sedimentation occurs in time, while newly built canals usually experience degradation (Jugaru et. al, 2006). This study reports and analyzes new data on the hydrological and sedimentary processes at work during a morphogenic flood in a large modified meander (the Mahmudia meander) of the St. George branch, the southern branch of the Danube Delta. The 100-year recurrent flood that occurred in 2006 offered an exceptional opportunity for scanning different cross sections of the Mahmudia meander system by means of the emerging Doppler profiler (aDcp) technology in order to analyze the impact on sedimentation and dynamic processes in the study area. The Mahmudia study site corresponds to a vast natural meander which was cut off in 1984-1988 by an artificial canal opened to shipping. The meander correction accelerated fluxes through the artificial canal and dramatically enhanced deposition in the former meander. After his formation, the cutoff meander acted as sediment storage locations, essentially removing channel and point bar sediments from the active sediment budget of the main channel (Popa, 1997). During the one-hundred-year recurrent flood in April 2006, bathymetry, flow velocity and discharge data were acquired across several sections of both natural and artificial channels with an acoustic Doppler current profiler (aDcp Workhorse Sentinel 600 kHz, Teledyne RDI) in order to investigate the distribution of the flow and sediment and his impact on sedimentation in a channelized reach and its adjacent cutoff. The contrasting hydro-sedimentary processes at work in both channels and bifurcation/confluence nodal points are analyzed from the measured flux distribution

  8. Defining a BMI Cut-Off Point for the Iranian Population: The Shiraz Heart Study

    PubMed Central

    Babai, Mohammad Ali; Arasteh, Peyman; Hadibarhaghtalab, Maryam; Naghizadeh, Mohammad Mehdi; Salehi, Alireza; Askari, Alireza; Homayounfar, Reza

    2016-01-01

    In this study we evaluated and redefined the optimum body mass index (BMI) cut-off point for the Iranian population based on metabolic syndrome (MeS) risk factors. We further evaluated BMI cut-off points with and without waist circumference (WC) as a cofactor of risk and compared the differences. This study is part of the largest surveillance programs conducted in Shiraz, Iran, termed the Shiraz Heart study. Our study sample included subjects between the ages of 20 to 65 years old. After excluding pregnant women, those with missing data and those with comorbid disease, a total of 12283 made up the study population. The participants underwent a series of tests and evaluations by trained professionals in accordance with WHO recommendations. Hypertension, abnormal fasting blood sugar (FBS), triglyceride (TG) and high density lipoprotein cholesterol (HDL) (in the context of the definition of metabolic syndrome) were prevalent among 32.4%, 27.6%, 42.1 and 44.2% of our participants, respectively. Women displayed higher rates of overall obesity compared to men (based on the definition by the WHO as higher than 30 kg/m2). Regarding MeS, 38.9% of our population had the all symptoms of MeS which was more prevalent among women (41.5% vs. 36%). When excluding WC in the definition of MeS, results showed that males tend to show a higher rate of metabolic risk factors (19.2% vs. 15.6%). Results of multivariate analysis showed that parallel to an increase in BMI, the odds ratio (OR) for acquiring each component of the metabolic syndrome increased (OR = 1.178; CI: 1.166–1.190). By excluding WC, the previous OR decreased (OR = 1.105; CI: 1.093–1.118). Receiver Operating Characteristic (ROC) curve analysis showed that the optimum BMI cut-off point for predicting metabolic syndrome was 26.1 kg/m2 and 26.2 kg/m2 [Accuracy (Acc) = 69% and 61%, respectively)] for males and females, respectively. The overall BMI cut-off for both sexes was 26.2 kg/m2 (Acc = 65%) with sensitivity and

  9. A review of the cut-off points for the diagnosis of vitamin B12 deficiency in the general population.

    PubMed

    Aparicio-Ugarriza, Raquel; Palacios, Gonzalo; Alder, Monika; González-Gross, Marcela

    2015-07-01

    Vitamin B12 deficit is one of the most common vitamin deficiencies. However, there is no consensus on the cut-off points for vitamin B12 and its co-markers, such as folate, holotranscobalamin, methylmalonic acid and homocysteine. In order to establish the state of the art about cut-off points used to determine vitamin B12 deficiency in the last decades, the database MEDLINE was used for searching studies published in adults between December 1992 and May 2014 (69 articles), using search terms like 'vitamin B12', 'cobalamin', 'cut-off', 'deficiency' alone or in combinations. Broad ranges of cut-off points for vitamin B12 and its biomarkers were identified: vitamin B12 ranged between 100 pmol/L and 350 pmol/L, holotranscobalamin 20-50 pmol/L, methylmalonic acid 0.210-0.470 μmol/L, homocysteine 10-21.6 μmol/L, serum folate 3.7-15.9 nmol/L and red blood cell 124-397 nmol/L. For the majority of studies, the potential influence of age, analytical methods, gender and fortified food consumption was not taken in account when choosing cut-off values. This could explain the discrepancies between studies on vitamin B12 and folate deficiency prevalences. We conclude that there is inconsistency in the literature regarding vitamin B12 cut-offs. It would be necessary to establish different reference cut-offs according to age, considering the analytical methods used.

  10. The Optimal Ethnic-Specific Waist-Circumference Cut-Off Points of Metabolic Syndrome among Low-Income Rural Uyghur Adults in Far Western China and Implications in Preventive Public Health

    PubMed Central

    He, Jia; Ma, Rulin; Liu, Jiaming; Zhang, Mei; Ding, Yusong; Guo, Heng; Mu, Lati; Zhang, Jingyu; Wei, Bin; Yan, Yizhong; Ma, Jiaolong; Pang, Hongrui; Li, Shugang; Guo, Shuxia

    2017-01-01

    Background: Metabolic syndrome is pandemic; however, the cut-off values for waist circumference (WC) vary widely depending on the ethnic groups studied and the criteria applied for WC measurement. Previous studies for defining optimal WC cut-off points included high-income and urban settings, and did not cover low-income, rural settings, especially for ethnic minorities. This study aimed at defining optimal ethnic-specific WC cut-off points in a low-income, rural population comprising the largest inhabitant minority group residing in far Western China. Methods: Questionnaire-based surveys, physical examinations, and blood testing of 3542 individuals were conducted in 2010, using a stratified cluster random sampling method in rural Uyghur residents (≥18 years old) from 12 villages in Xinjiang, China, approximately 4407 km away from the capital city, Beijing. Metabolic syndrome was defined according to the International Diabetes Federation (IDF) criteria. Optimal, ethnic-specific WC cut-off values for diagnosing metabolic syndrome were determined using receiver operator characteristic (ROC) curve analysis. Results: As WC increased, there was a significant, increasing trend of detection and risk in rural Uyghur adults, regardless of the presence of ≥1 or ≥2 components of metabolic syndrome by IDF criteria. The optimal ethnic-specific WC cut-off point to predict the presence of metabolic syndrome was 85 cm for men and 82 cm for women. With these cut-off points, the prevalence rates of metabolic syndrome among men, women, and overall population in Uyghur adults were 19.5%, 23.0%, and 21.3%, respectively. Conclusions: We report a high prevalence of metabolic syndrome, especially in women, among rural Uyghurs in Western China. A WC cut-off of 85 cm in men and 82 cm in women was the best predictor of metabolic syndrome in this population. Because of the cost-effectiveness in measuring WC, we recommend that these WC cut-off points be integrated into local preventive

  11. The Optimal Ethnic-Specific Waist-Circumference Cut-Off Points of Metabolic Syndrome among Low-Income Rural Uyghur Adults in Far Western China and Implications in Preventive Public Health.

    PubMed

    He, Jia; Ma, Rulin; Liu, Jiaming; Zhang, Mei; Ding, Yusong; Guo, Heng; Mu, Lati; Zhang, Jingyu; Wei, Bin; Yan, Yizhong; Ma, Jiaolong; Pang, Hongrui; Li, Shugang; Guo, Shuxia

    2017-02-08

    Background: Metabolic syndrome is pandemic; however, the cut-off values for waist circumference (WC) vary widely depending on the ethnic groups studied and the criteria applied for WC measurement. Previous studies for defining optimal WC cut-off points included high-income and urban settings, and did not cover low-income, rural settings, especially for ethnic minorities. This study aimed at defining optimal ethnic-specific WC cut-off points in a low-income, rural population comprising the largest inhabitant minority group residing in far Western China. Methods: Questionnaire-based surveys, physical examinations, and blood testing of 3542 individuals were conducted in 2010, using a stratified cluster random sampling method in rural Uyghur residents (≥18 years old) from 12 villages in Xinjiang, China, approximately 4407 km away from the capital city, Beijing. Metabolic syndrome was defined according to the International Diabetes Federation (IDF) criteria. Optimal, ethnic-specific WC cut-off values for diagnosing metabolic syndrome were determined using receiver operator characteristic (ROC) curve analysis. Results: As WC increased, there was a significant, increasing trend of detection and risk in rural Uyghur adults, regardless of the presence of ≥1 or ≥2 components of metabolic syndrome by IDF criteria. The optimal ethnic-specific WC cut-off point to predict the presence of metabolic syndrome was 85 cm for men and 82 cm for women. With these cut-off points, the prevalence rates of metabolic syndrome among men, women, and overall population in Uyghur adults were 19.5%, 23.0%, and 21.3%, respectively. Conclusions: We report a high prevalence of metabolic syndrome, especially in women, among rural Uyghurs in Western China. A WC cut-off of 85 cm in men and 82 cm in women was the best predictor of metabolic syndrome in this population. Because of the cost-effectiveness in measuring WC, we recommend that these WC cut-off points be integrated into local preventive

  12. IMPLICATION OF THE OBSERVED SPECTRAL CUTOFF ENERGY EVOLUTION IN XTE J1550-564

    SciTech Connect

    Titarchuk, Lev; Shaposhnikov, Nikolai E-mail: lev.titarchuk@nrl.navy.mi

    2010-12-01

    The physical mechanisms responsible for the production of non-thermal emission in accreting black holes (BHs) should be imprinted in the observational appearances of the power-law tails in the X-ray spectra from these objects. Phenomenology of different spectral states exhibited by galactic BH binaries allows us to establish the physics of the photon upscattering under different accretion regimes. We revisit the data collected by the Rossi X-ray Timing Explorer from the BH X-ray binary XTE J1550-564 during two periods of X-ray activity in 1998 and 2000 focusing on the behavior of the high-energy cutoff of the power-law part of the spectrum. For the 1998 outburst, the transition from the low-hard state to the intermediate state was accompanied by a gradual decrease in the cutoff energy. This was followed by an extended minimum which then showed an abrupt reversal to a clear increasing trend as the source evolved to the very high and high-soft states. The 2000 outburst showed only the decreasing and extended minimum portions of this pattern. We attribute this difference in the cutoff energy behavior to the different partial contributions of the thermal and non-thermal (bulk motion) Comptonization. Namely, during the 1998 event the higher accretion rate presumably provided more cooling to the Comptonizing media and thus reducing the effectiveness of the thermal upscattering process. Under these conditions, the bulk motion takes a leading role in boosting the input soft photons. Recent Monte Carlo simulations by Laurent and Titarchuk strongly support this scenario.

  13. Diagnostic Cutoff Value for Ultrasonography of the Common Fibular Neuropathy at the Fibular Head

    PubMed Central

    2016-01-01

    Objective To establish the diagnostic cutoff value of ultrasonographic measurement for common fibular neuropathy (CFN) at the fibular head (FH). Methods Twenty patients with electrodiagnostically diagnosed CFN at the FH and 30 healthy controls were included in the study. The cross-sectional area (CSA) of sciatic nerve at mid-thigh level, common fibular nerve at popliteal fossa (PF), and common fibular (CF) nerve at FH were measured. Additionally, the difference of CF nerve CSA at the FH between symptomatic side and asymptomatic side (ΔSx–Asx), the ratio of CF nerve CSA at FH to at PF (FH/PF), and the ratio of CF nerve CSA at the FH symptomatic side to asymptomatic side (Ratio Sx–Asx) were calculated. Results CSA at the FH, FH/PF, ΔSx–Asx, and Ratio Sx–Asx showed significant differences between the patient and control groups. The cutoff value for diagnosing CFN at the FH was 11.7 mm2 for the CSA at the FH (sensitivity 85.0%, specificity 90.0%), 1.70 mm2 for the ΔSx–Asx (sensitivity 83.3%, specificity 97.0%), 1.11 for the FH/PF (sensitivity 47.1%, specificity 93.3%), and 1.24 for the Ratio Sx–Asx (sensitivity 72.2%, specificity 96.7%). Conclusion The ultrasonographic measurement and cutoff value could be a valuable reference in diagnosing CFN at the FH and improving diagnostic reliability and efficacy. PMID:28119836

  14. Interstellar Flow Longitude from the Symmetry of the Pickup Ion Cut-off at 1 AU

    NASA Astrophysics Data System (ADS)

    Möbius, E.; Lee, M. A.; Drews, C.

    2015-12-01

    We provide a proof of concept that the pickup ion (PUI) cutoff speed variation with ecliptic longitude can provide the interstellar neutral (ISN) flow longitude {λ }{ISN∞ } outside the heliosphere with a precision of the order of 0.°1. We compare 2007-2014 STEREO A PLASTIC observations in the solar wind frame with a simple analytical cutoff model and perform a Pearson correlation of the cutoff as a function of longitude with those values mirrored about a location λM that slides in longitude. The resulting maximum correlation at λM = 255.°21 ± 0.°04 reflects the ISN upwind direction with a purely statistical uncertainty. This result is consistent with recent ISN flow longitude values, but a precision determination requires the evaluation of underlying systematic effects. Obtaining a precision ISN flow longitude is highly complementary to the IBEX ISN observations, which return a narrow tube in the ISN parameter space that couples flow speed and longitude tightly, but leaves a substantially larger error bar along the tube. The ISN flow provides one cardinal axis of the heliosphere, with a strong leverage on the plane subtended by the ISN velocity and the interstellar magnetic field vector, which controls the shape of the heliosphere and its interaction with the interstellar medium. In addition, a discussion about potential temporal variations of the ISN flow has started. Both issues require a precision determination of the ISN flow velocity over decade-long time intervals. ACE SWICS, STEREO PLASTIC, and SOHO CTOF PUI data allow such long-term studies over almost two decades.

  15. Asymmetrical Changes in Hydraulic Gradient Along Valley and River Transects During Meander Cutoff Evolution

    NASA Astrophysics Data System (ADS)

    Han, B.; Endreny, T.

    2009-05-01

    This work is motivated by the uncertainty about the presence and rate of steepening in river and valley hydraulic gradients bounding meander bends during meander cutoff, and how these gradients may affect river restoration designs. Our science question is whether the river and valley hydraulic gradients are equal and unchanging during meander cutoff. Laboratory investigations are underway prior to field experiments and model simulations. The laboratory physical model is a 2.1m x 0.9m EmRiver Process Simulator, running approximately 20 minutes per simulation, using particulate matter with a specific gravity of 1.6, a flow rate of 45ml/s, an initial river cross-section averaging 24cm2, and a range of radius of curvature from 15cm to 18cm. We calculated gradient using river water surface and valley watertable measurements, and their separation along a fixed orientation parallel to the valley slope, not along the thalweg. Measurements were taken with auto level, rod, and tape, and orthoimagery was captured to refine estimates of channel geometry. The ERDAS Leica Photogrammetry Suite processes digital images to generate digital elevation models (DEM) of the system. Initial results have confirmed a steepening of the river hydraulic gradient, from 4% to 5.5% for initial radius of curvature of 15cm, and from 7.7% to 10.9% for curvature of 18cm. The valley watertable gradient has a slight reduction or flattening of about 0.4%. Changes in channel geometry during cutoff include adjustments to cross-sectional area and increasing meander wavelength and sinuosity.

  16. Special nuclear materials cutoff exercise: Issues and lessons learned. Volume 1: Summary of exercise

    SciTech Connect

    Libby, R.A.; Davis, C.; Segal, J.E.; Stanbro, W.D.

    1995-08-01

    In a September 1993 address to the United Nations General Assembly, President Clinton announced a new nonproliferation and export control policy that established a framework for US efforts to prevent the proliferation of weapons of mass destruction. The new policy proposed that the US undertake a comprehensive approach to the growing accumulation of fissile material. One of the key elements was for the US to support a special nuclear materials (SNM) multilateral convention prohibiting the production of highly enriched uranium (HEU) or plutonium for nuclear explosives purposes or outside of international safeguards. This policy is often referred to as the President`s Cutoff Initiative or the Fissile Material Cutoff Treaty (FMCT). Because both the US Department of Energy (DOE) and foreign reprocessing facilities similar to PUREX will likely to be inspected under a FMCT, the DOE Office of Arms Control and Nonproliferation, Negotiations and Analysis Division (DOE/NN-41) tasked Pacific Northwest Laboratory (PNL) to perform an information gathering exercise, the PUREX Exercise, using the Plutonium-Uranium Extraction (PUREX) Plant located on the Hanford Site in Washington State. PUREX is a former production reactor fuel reprocessing plant currently undergoing a transition to a ``decontamination and decommissioning (D&D) ready`` mode. The PUREX Exercise was conducted March 29--30, 1994, to examine aspects of the imposition of several possible cutoff regimes and to study verification of non-production of SNM for nuclear weapons purposes or outside of safeguards. A follow-up activity to further examine various additional verification regimes was held at Los Alamos National Laboratory (LANL) on May 10, 1994.

  17. Cosmic Ray Modulation Observed by the Princess Sirindhorn Neutron Monitor at High Rigidity Cutoff

    NASA Astrophysics Data System (ADS)

    Mangeard, Pierre-Simon; Pyle, Roger; Evenson, Paul; Ruffolo, David; Saiz, Alejandro; Clem, John; Madlee, Suttiwat; Nutaro, Tanin

    2016-07-01

    Neutron monitors (NMs) are the premier instruments for precisely tracking time variations in the Galactic cosmic ray (GCR) flux at the GV-range. For more than 60 years, the worldwide NM network has provided continuous measurements of the solar induced variations of the GCR flux impinging Earth and the data cover about six 11-year solar cycles. The recent rise of space exploration, with PAMELA and AMS-02 spacecraft, brings new energy sensitive measurements of GCR fluxes. Moreover since late 2007, the range of sensitivity of the worldwide NM network has been increased with the installation of the Princess Sirindhorn Neutron Monitor (PSNM), at the summit of Doi Inthanon, Thailand's highest mountain (2565 m altitude). PSNM records the GCR flux with the world's highest vertical rigidity cutoff for a fixed station, 16.8 GV. PSNM data now cover the period from the last solar minimum to the recent solar maximum and give us the opportunity to study the effect of the solar modulation at such high rigidity for the first time. We present here the observations of PSNM since 2007. The observed solar modulation is much weaker than predicted by the force field model with φ inferred from NM data at low cutoff. We compare measurements with those from NMs located at low rigidity cutoff and with spacecraft data. We discuss the solar modulation at high rigidity. Partially supported by a postdoctoral fellowship from Mahidol University, the Thailand Research Fund (BRG 5880009), the Science Achievement Scholarship of Thailand, and US National Science Foundation awards PLR-1341562, PLR-1245939, and their predecessors.

  18. Enhanced trans-Himalaya pollution transport to the Tibetan Plateau by cut-off low systems

    NASA Astrophysics Data System (ADS)

    Zhang, Ruixiong; Wang, Yuhang; He, Qiusheng; Chen, Laiguo; Zhang, Yuzhong; Qu, Hang; Smeltzer, Charles; Li, Jianfeng; Alvarado, Leonardo M. A.; Vrekoussis, Mihalis; Richter, Andreas; Wittrock, Folkard; Burrows, John P.

    2017-02-01

    Long-range transport followed by deposition of black carbon on glaciers of Tibet is one of the key issues of climate research as it induces changes on radiative forcing and subsequently impacting the melting of glaciers. The transport mechanism, however, is not well understood. In this study, we use short-lived reactive aromatics as proxies to diagnose transport of pollutants to Tibet. In situ observations of short-lived reactive aromatics across the Tibetan Plateau are analyzed using a regional chemistry and transport model. The model performance using the current emission inventories over the region is poor due to problems in the inventories and model transport. Top-down emissions constrained by satellite observations of glyoxal are a factor of 2-6 higher than the a priori emissions over the industrialized Indo-Gangetic Plain. Using the top-down emissions, agreement between model simulations and surface observations of aromatics improves. We find enhancements of reactive aromatics over Tibet by a factor of 6 on average due to rapid transport from India and nearby regions during the presence of a high-altitude cut-off low system. Our results suggest that the cut-off low system is a major pathway for long-range transport of pollutants such as black carbon. The modeling analysis reveals that even the state-of-the-science high-resolution reanalysis cannot simulate this cut-off low system accurately, which probably explains in part the underestimation of black carbon deposition over Tibet in previous modeling studies. Another model deficiency of underestimating pollution transport from the south is due to the complexity of terrain, leading to enhanced transport. It is therefore challenging for coarse-resolution global climate models to properly represent the effects of long-range transport of pollutants on the Tibetan environment and the subsequent consequence for regional climate forcing.

  19. Cut-off values of blessed dementia rating scale and its clinical application in elderly Taiwanese.

    PubMed

    Yang, Yuan-Han; Lai, Chiou-Lian; Lin, Ruey-Tay; Tai, Chih-Ta; Liu, Ching-Kuan

    2006-08-01

    Although the Blessed Dementia Rating Scale (BDRS), a clinical screening instrument, has been applied extensively, no suitable cut-off values and clinical application have been proposed, particularly in mild cognitive impairment (MCI), the precursor of dementia. The BDRS, Mini Mental State Examination (MMSE), and Clinical Dementia Rating Scale (CDR) were administrated in people aged 65 years and above, who were enrolled from southern Taiwan with multistep stratified random sampling and followed-up for 2 years. All subjects (total number = 3,027), with new onset of MCI (defined as CDR = 0.5) in the first year and dementia (defined as CDR > or = 1) in the second and third years were subjected to statistical analysis. In distinguishing normal from MCI, except in the literate group aged 65-74 years, MMSE was superior to BDRS, with cut-off values of 1 in both literate groups aged 65-74 years and > or = 75 years, and 1.5 and 2 in less educated groups aged 65-74 and > or = 75 years, respectively. In distinguishing MCI from dementia, BDRS had cut-off values of 2.5 in both literate groups aged 65-74 and > or = 75 years, and 2.5 and 3 in less educated groups aged 65-74 and > or = 75 years, respectively. These values were better than those for MMSE in all groups. BDRS might be considered as a better tool than MMSE to screen for MCI and dementia in the increasing proportion of literate elderly aged 65-74 years in the aging population.

  20. Revisiting AdS/CFT at a finite radial cut-off

    NASA Astrophysics Data System (ADS)

    Mandal, Gautam; Nayak, Pranjal

    2016-12-01

    We revisit AdS/CFT at a finite radial cut-off, specifically in the context of double trace perturbations, O_n=O(x){({partial}^2)}^nO(x) , with arbitrary powers n. As well-known, the standard GKPW prescription, applied to a finite radial cut-off, leads to contact terms in correlators. de Haro et al. [1] introduced bulk counterterms to remove these. This prescription, however, yields additional terms in the correlator corresponding to spurious double trace deformations. Further, if we view the GKPW prescription coupled with the prescription in [1], in terms of a boundary wavefunction, we find that it is incompatible with radial Schrödinger evolution (in the spirit of holographic Wilsonian RG). We consider a more general wavefunction satisfying the Schrödinger equation, and find that generically such wavefunctions generate both (a) double trace deformations and (b) contact terms. However, we find that there exist special choices of these wavefunctions, amounting to a new AdS/CFT prescription at a finite cut-off, so that both (a) and (b) are removed and we obtain a pure power law behaviour for the correlator. We compare these special wavefunctions with a specific RG scheme in field theory. We give a geometric interpretation of these wavefunctions; these correspond to some specific smearing of boundary points in the Witten diagrams. We present a comprehensive calculation of exact double-trace beta-functions for all couplings O_n and match with a holographic computation using the method described above. The matching works with a mapping between the field theory and bulk couplings; such a map is highly constrained because the beta-functions are quadratic and exact on both sides. Our discussions include a generalization of the standard double-trace Wilson-Fisher flow to the space of the infinite number of couplings.

  1. An Empirical Evaluation of the Use of Fixed Cutoff Points in RMSEA Test Statistic in Structural Equation Models

    PubMed Central

    Chen, Feinian; Curran, Patrick J.; Bollen, Kenneth A.; Kirby, James; Paxton, Pamela

    2009-01-01

    This article is an empirical evaluation of the choice of fixed cutoff points in assessing the root mean square error of approximation (RMSEA) test statistic as a measure of goodness-of-fit in Structural Equation Models. Using simulation data, the authors first examine whether there is any empirical evidence for the use of a universal cutoff, and then compare the practice of using the point estimate of the RMSEA alone versus that of using it jointly with its related confidence interval. The results of the study demonstrate that there is little empirical support for the use of .05 or any other value as universal cutoff values to determine adequate model fit, regardless of whether the point estimate is used alone or jointly with the confidence interval. The authors' analyses suggest that to achieve a certain level of power or Type I error rate, the choice of cutoff values depends on model specifications, degrees of freedom, and sample size. PMID:19756246

  2. Cut-off effect of radical TEMPO derivatives in olive oil-in-water emulsions.

    PubMed

    Lopez de Arbina, Amaia; Rezende, Marcos Caroli; Aliaga, Carolina

    2017-06-01

    Three oil-in-water emulsions were prepared from mixtures of olive oil and Tween 20 in water. The effectiveness of a series of radical 2,2,6,6-tetramethylpiperidinoxyl (TEMPO) derivatives of variable lipophilicity in reactions with antioxidant Trolox, and as pyrene-fluorescence quenchers, was compared in the three emulsions. A "cut-off" effect was observed for the pyrene quenching by the probes, but not for their reaction with Trolox. The results were rationalized in terms of the amphiphobic nature of the probes, and the different locations of probe, pyrene and Trolox in the three-phase microheterogeneous systems.

  3. Insensitivity of Hawking radiation to an invariant Planck-scale cutoff

    SciTech Connect

    Agullo, Ivan; Navarro-Salas, Jose; Olmo, Gonzalo J.; Parker, Leonard

    2009-08-15

    A disturbing aspect of Hawking's derivation of black hole radiance is the need to invoke extreme conditions for the quantum field that originates the emitted quanta. It is widely argued that the derivation requires the validity of the conventional relativistic field theory to arbitrarily high, trans-Planckian scales. We stress in this note that this is not necessarily the case if the question is presented in a covariant way. We point out that Hawking radiation is immediately robust against an invariant Planck-scale cutoff. This important feature of Hawking radiation is relevant for a quantum gravity theory that preserves, in some way, the Lorentz symmetry.

  4. Simulation of reflectometry Bragg backscattering spectral responses in the absence of a cutoff layer

    SciTech Connect

    Silva, F. da; Graca, S. da; Conway, G. D.; Collaboration: ASDEX Upgrade Team

    2010-10-15

    Experimental reflectometry signals obtained in the absence of a cutoff layer, with the possibility of interferometric operation excluded, show a coherent and recurrent frequency spectrum signature similar to an Alfven cascade signature. A possible explanation resides in the modulation of a resonant Bragg backscattering response by an Alfven mode structure located at the center of the plasma whose frequency of oscillation modulates the backscattered signal in a conformable way. This situation is modeled and simulated using an O-mode full-wave Maxwell finite-difference time-domain code and the resulting signatures are discussed.

  5. Interstellar Flow Longitude from Pickup Ion Cut-off Observations at 1 AU

    NASA Astrophysics Data System (ADS)

    Moebius, E.; Lee, M. A.; Gloeckler, G.; Drews, C.

    2015-12-01

    The precise determination of the interstellar neutral (ISN) flow direction is important in several different ways. As a cardinal axis of the heliosphere it has strong leverage on the plane subtended by the ISN velocity and interstellar magnetic field vector, which controls the shape of the heliosphere and its interaction with the interstellar medium. The observation of the ISN flow through the heliosphere for several decades has initiated a discussion about potential temporal variations in the ISN flow. To tackle these questions, a precision measurement of the ISN flow velocity vector is needed over a long time period. Recent efforts to obtain a consistent ISN vector and temperature with Ulysses and IBEX point to remaining uncertainties and potential systematic effects. In particular, IBEX measurements provide a very precise relation between ISN flow longitude and speed via the hyperbolic trajectory equation, but they contain larger uncertainties separately for longitude and speed. Pickup ion (PUI) observations of the ISN flow pattern at 1 AU can provide a complementary determination of the flow longitude with high precision. The interstellar PUI cut-off speed is a function of the ratio of the radial ISN flow component and the solar wind speed at the observer location [Möbius et al., 1999, GRL, 26, 3181]. We have compared STEREO A PLASTIC observations with a simple analytic model of the cut-off and performed a Pearson correlation analysis of the cut-off as a function of ecliptic longitude with its mirrored function. The two complementary approaches demonstrate that the ISN flow longitude can be obtained with a precision on the order of 0.1o. The cut-off speed is much less sensitive to systematic effects on PUIs, such as variations in the solar wind parameters, ionization, and transport. ACE SWICS, STEREO PLASTIC, and SOHO CTOF data are available that span almost two decades, which will allow long term studies with high precision. The availability of O and Ne PUI

  6. Development of megapixel HgCdTe detector arrays with 15 micron cutoff

    NASA Astrophysics Data System (ADS)

    Forrest, William J.; McMurtry, Craig W.; Dorn, Meghan L.; Pipher, Judith; Cabrera, Mario S.

    2016-06-01

    I. HistoryHgCdTe is a versatile II-VI semiconductor with a direct-bandgap tunable via the Hg:Cd ratio. Hg:Cd ratio = 53:47 (2.5 micron cutoff) was used on the NICMOS instrument on HST and the 2MASS. Increasing Hg:Cd ratio to 70:30 leads to a 5.4 micron cutoff, utilized in NEOWISE and many JWST instruments. Bailey, Wu et al. (1998) motivated extending this technology to 10 microns and beyond. Bacon, McMurtry et al. (2003, 2004) indicated significant progress toward this longwave (LW) goal.Warm-Spitzer has pioneered passive cooling to below 30 K in space, enabling the JWST mission.II. CurrentNASA's proposed NEOcam mission selected HgCdTe with a 10.6 micron cutoff because it promises natural Zodiacal background limited sensitivity with modest cooling (40 K). Teledyne Imaging Systems (TIS) is producing megapixel arrays with excellent performance (McMurtry, Lee, Dorn et al. (2013)) for this mission.III. FutureModest cooling requirements (circa 30 K) coupled with megapixel arrays and LW sensitivity in the thermal IR make HgCdTe attractive for many infrared instruments. For instance, the spectral signature of a terrestrial planet orbiting in the habitable zone of a nearby star will be the deep and wide absorption by CO_2 centered at 15 microns (Seager and Deming, 2010). LW instruments can enhance Solar System missions, such as exploration of the Enceladus geysers (Spencer, Buratti et al. 2006). Passive cooling will be adequate for these missions. Modern ground-based observatories will benefit from infrared capability out to the N band (7.5-13.6 microns). The required detector temperatures (30-40 K) are easily achievable using commercially available mechanical cryo-coolers (refrigerators).IV. Progress to dateTIS is developing megapixel HgCdTe arrays sensitive out to 15 microns under the direction of the University of Rochester. As a first step, we have produced arrays with a 13 micron cutoff. The initial measurements indicate very promising performance. We will present the

  7. Development of megapixel HgCdTe detector arrays with 15 micron cutoff

    NASA Astrophysics Data System (ADS)

    Forrest, William J.; McMurtry, Craig W.; Dorn, Meghan; Pipher, Judith; Cabrera, Mario S.

    2016-10-01

    I. HistoryHgCdTe is a versatile II-VI semiconductor with a direct-bandgap tunable via the Hg:Cd ratio. Hg:Cd ratio = 53:47 (2.5 micron cutoff) was used on the NICMOS instrument on HST and the 2MASS. Increasing Hg:Cd ratio to 70:30 leads to a 5.4 micron cutoff, utilized in NEOWISE and many JWST instruments. Bailey, Wu et al. (1998) motivated extending this technology to 10 microns and beyond. Bacon, McMurtry et al. (2003, 2004) indicated significant progress toward this longwave (LW) goal.Warm-Spitzer has pioneered passive cooling to below 30 K in space, enabling the JWST mission.II. CurrentNASA's proposed NEOcam mission selected HgCdTe with a 10.6 micron cutoff because it promises natural Zodiacal background limited sensitivity with modest cooling (40 K). Teledyne Imaging Systems (TIS) is producing megapixel arrays with excellent performance (McMurtry, Lee, Dorn et al. (2013)) for this mission.III. FutureModest cooling requirements (circa 30 K) coupled with megapixel arrays and LW sensitivity in the thermal IR make HgCdTe attractive for many infrared instruments. For instance, the spectral signature of a terrestrial planet orbiting in the habitable zone of a nearby star will be the deep and wide absorption by CO_2 centered at 15 microns (Seager and Deming, 2010). LW instruments can enhance Solar System missions, such as exploration of the Enceladus geysers (Spencer, Buratti et al. 2006). Passive cooling will be adequate for these missions. Modern ground-based observatories will benefit from infrared capability out to the N band (7.5-13.6 microns). The required detector temperatures (30-40 K) are easily achievable using commercially available mechanical cryo-coolers (refrigerators).IV. Progress to dateTIS is developing megapixel HgCdTe arrays sensitive out to 15 microns under the direction of the University of Rochester. As a first step, we have produced arrays with a 13 micron cutoff. The initial measurements indicate very promising performance. We will present the

  8. A rack-mounted precision waveguide-below-cutoff attenuator with an absolute electronic readout

    NASA Technical Reports Server (NTRS)

    Cook, C. C.

    1974-01-01

    A coaxial precision waveguide-below-cutoff attenuator is described which uses an absolute (unambiguous) electronic digital readout of displacement in inches in addition to the usual gear driven mechanical counter-dial readout in decibels. The attenuator is rack-mountable and has the input and output RF connectors in a fixed position. The attenuation rate for 55, 50, and 30 MHz operation is given along with a discussion of sources of errors. In addition, information is included to aid the user in making adjustments on the attenuator should it be damaged or disassembled for any reason.

  9. Nonet meson properties in the Nambu-Jona-Lasinio model with dimensional versus cutoff regularization

    SciTech Connect

    Inagaki, T.; Kimura, D.; Kohyama, H.; Kvinikhidze, A.

    2011-02-01

    The Nambu-Jona-Lasinio model with a Kobayashi-Maskawa-'t Hooft term is one low energy effective theory of QCD which includes the U{sub A}(1) anomaly. We investigate nonet meson properties in this model with three flavors of quarks. We employ two types of regularizations, the dimensional and sharp cutoff ones. The model parameters are fixed phenomenologically for each regularization. Evaluating the kaon decay constant, the {eta} meson mass and the topological susceptibility, we show the regularization dependence of the results and discuss the applicability of the Nambu-Jona-Lasinio model.

  10. Measure Valued Solutions to the Spatially Homogeneous Boltzmann Equation Without Angular Cutoff

    NASA Astrophysics Data System (ADS)

    Morimoto, Yoshinori; Wang, Shuaikun; Yang, Tong

    2016-12-01

    A uniform approach is introduced to study the existence of measure valued solutions to the homogeneous Boltzmann equation for both hard potential with finite energy, and soft potential with finite or infinite energy, by using Toscani metric. Under the non-angular cutoff assumption on the cross-section, the solutions obtained are shown to be in the Schwartz space in the velocity variable as long as the initial data is not a single Dirac mass without any extra moment condition for hard potential, and with the boundedness on moments of any order for soft potential.

  11. Level density inputs in nuclear reaction codes and the role of the spin cutoff parameter

    SciTech Connect

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Burger, A.; Gorgen, A.; Guttormsen, M.; Larsen, A. C.; Massey, T. N.; Siem, S.

    2014-09-03

    Here, the proton spectrum from the 57Fe(α,p) reaction has been measured and analyzed with the Hauser-Feshbach model of nuclear reactions. Different input level density models have been tested. It was found that the best description is achieved with either Fermi-gas or constant temperature model functions obtained by fitting them to neutron resonance spacing and to discrete levels and using the spin cutoff parameter with much weaker excitation energy dependence than it is predicted by the Fermi-gas model.

  12. Level density inputs in nuclear reaction codes and the role of the spin cutoff parameter

    DOE PAGES

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; ...

    2014-09-03

    Here, the proton spectrum from the 57Fe(α,p) reaction has been measured and analyzed with the Hauser-Feshbach model of nuclear reactions. Different input level density models have been tested. It was found that the best description is achieved with either Fermi-gas or constant temperature model functions obtained by fitting them to neutron resonance spacing and to discrete levels and using the spin cutoff parameter with much weaker excitation energy dependence than it is predicted by the Fermi-gas model.

  13. Optimal Cutoffs of Obesity Measures in Relation to Cancer Risk in Postmenopausal Women in the Women's Health Initiative Study

    PubMed Central

    Kabat, Geoffrey C.; Strickler, Howard D.; Lin, Juan; Hou, Lifang; Stefanick, Marcia L.; Anderson, Garnet L.; Rohan, Thomas E.

    2015-01-01

    Abstract Background: Obesity is a risk factor for several cancers in postmenopausal women. We attempted to determine cutoffs of adiposity measures in relation to risk of obesity-related cancers among postmenopausal women and to examine the effects of hormone therapy (HT) use on the cutoffs, neither of which has been broadly studied. Methods: We used data from the Women's Health Initiative cohort (n=144,701) and applied Cox-proportional hazards regressions to each combination of 17 cancer types and 6 anthropometric measures (weight, body mass index [BMI], weight to height ratio, waist circumference, waist to hip ratio [WHR], and waist to height ratio). Interactions between the anthropometric measures and HT use were also examined. Cutoffs were determined by applying a grid search followed by a two-fold cross validation method. Survival ROC analysis of 5- and 10-year incidence followed. Results: Breast, colorectal, colon, endometrium, kidney, and all cancers combined were significantly positively associated with all six anthropometric measures, whereas lung cancer among ever smokers was significantly inversely associated with all measures except WHR. The derived cutoffs of each obesity measure varied across cancers (e.g., BMI cutoffs for breast and endometrium cancers were 30 kg/m2 and 34 kg/m2, respectively), and also depended on HT use. The Youden indices of the cutoffs for predicting 5- and 10-year cancer incidence were higher among HT never users. Conclusion: Using a panel of different anthropometric measures, we derived optimal cut-offs categorizing populations into high- and low-risk groups, which differed by cancer type and HT use. Although the discrimination abilities of these risk categories were generally poor, the results of this study could serve as a starting point from which to determine adiposity cutoffs for inclusion in risk prediction models for specific cancer types. PMID:25587642

  14. Cut-off wavenumber of Alfvén waves in partially ionized plasmas of the solar atmosphere

    NASA Astrophysics Data System (ADS)

    Zaqarashvili, T. V.; Carbonell, M.; Ballester, J. L.; Khodachenko, M. L.

    2012-08-01

    Context. Alfvén wave dynamics in partially ionized plasmas of the solar atmosphere shows that there is indeed a cut-off wavenumber, i.e. the Alfvén waves with wavenumbers higher than the cut-off value are evanescent. The cut-off wavenumber appears in single-fluid magnetohydrodynamic (MHD) approximation but it is absent in a multi-fluid approach. Up to now, an explanation for the existence of the cut-off wavenumber is still missing. Aims: The aim of this paper is to point out the reason for the appearance of a cut-off wavenumber in single-fluid MHD. Methods: Beginning with three-fluid equations (with electrons, protons and neutral hydrogen atoms), we performed consecutive approximations until we obtained the usual single-fluid description. We solved the dispersion relation of linear Alfvén waves at each step and sought the approximation responsible of the cut-off wavenumber appearance. Results: We have found that neglecting inertial terms significantly reduces the real part of the Alfvén frequency although it never becomes zero. Therefore, the cut-off wavenumber does not exist at this stage. However, when the inertial terms together with the Hall term in the induction equation are neglected, the real part of the Alfvén frequency becomes zero. Conclusions: The appearance of a cut-off wavenumber, when Alfvén waves in partially ionized regions of the solar atmosphere are studied, is the result of neglecting inertial and Hall terms, therefore it has no physical origin.

  15. Comparing Approaches to Optimize Cut-off Scores for Short Cognitive Screening Instruments in Mild Cognitive Impairment and Dementia

    PubMed Central

    O’Caoimh, Rónán; Gao, Yang; Svendovski, Anton; Gallagher, Paul; Eustace, Joseph; Molloy, D. William

    2017-01-01

    Background: Although required to improve the usability of cognitive screening instruments (CSIs), the use of cut-off scores is controversial yet poorly researched. Objective: To explore cut-off scores for two short CSIs: the Standardized Mini-Mental State Examination (SMMSE) and Quick Mild Cognitive Impairment (Qmci) screen, describing adjustments in scores for diagnosis (MCI or dementia), age (≤, >75 years), and education (<, ≥12 years), comparing two methods: the maximal accuracy approach, derived from receiver operating characteristic curves, and Youden’s Index. Methods: Pooled analysis of assessments from patients attending memory clinics in Canada between 1999–2010 : 766 with mild cognitive impairment (MCI) and 1,746 with dementia, and 875 normal controls. Results: The Qmci was more accurate than the SMMSE in differentiating controls from MCI or cognitive impairment (MCI and dementia). Employing the maximal accuracy approach, the optimal SMMSE cut-off for cognitive impairment was <28/30 (AUC 0.86, sensitivity 74%, specificity 88%) versus <63/100 for the Qmci (AUC 0.93, sensitivity 85%, specificity 85%). Using Youden’s Index, the optimal SMMSE cut-off remained <28/30 but fell slightly to <62/100 for the Qmci (sensitivity 83%, specificity 87%). The optimal cut-off for MCI was <29/30 for the SMMSE and <67/100 for the Qmci, irrespective of technique. The maximal accuracy approach generally produced higher Qmci cut-offs than Youden’s Index, both requiring adjustment for age and education. There were no clinically meaningful differences in SMMSE cut-off scores by age and education or method employed. Conclusion: Caution should be exercised selecting cut-offs as these differ by age, education, and method of derivation, with the extent of adjustment varying between CSIs. PMID:28222528

  16. Cognitive Characteristics of Children with Mathematics Learning Disability (MLD) Vary as a Function of the Cutoff Criterion Used to Define MLD

    ERIC Educational Resources Information Center

    Murphy, Melissa M.; Mazzocco, Michele M. M.; Hanich, Laurie B.; Early, Martha C.

    2007-01-01

    Researchers of mathematics learning disability (MLD) commonly use cutoff scores to determine which participants have MLD. Some researchers apply more restrictive cutoffs than others (e.g., performance below the 10th vs. below the 35th percentile). Different cutoffs may lead to groups of children that differ in their profile of math and related…

  17. Impact of Different Cutoff Criteria on Rate of (Central) Auditory Processing Disorders Diagnosis Using the Central Test Battery

    PubMed Central

    Shaikh, Mohsin Ahmed; Fox-Thomas, Lisa; Tucker, Denise

    2016-01-01

    The purpose of this study was to quantify how the use of two different cutoff criteria affects the test failure rate and potential diagnosis of central auditory processing disorder ([C]APD) in a sample of children subjected to central auditory processing ([C]AP) assessment. Test failure rates for the central test battery (CTB) using two different cutoff criteria (1 and 2 SDs below the mean) were measured retrospectively for 98 children who completed (C)AP assessment. The rates of potential (C)APD diagnosis ranged from 86.8% [when a 1 standard deviation (SD) cutoff was used] to 66.2% (when a 2 SD cutoff was used). The current use of two different cutoffs for the CTB has a large impact on the diagnostic rate for (C)APD. These findings have clinical implications for the diagnosis of (C)APD due to the widespread use of the CTB in the United States for the assessment of (C)APD in children. Thus, it is important to create awareness among audiologists that use of the 2 SDs cutoff criterion is recommended for reducing false positives (error). PMID:27942373

  18. Optimised cut-off function for Tersoff-like potentials for a BN nanosheet: a molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Kumar, Rajesh; Rajasekaran, G.; Parashar, Avinash

    2016-02-01

    In this article, molecular dynamics based simulations were carried out to study the tensile behaviour of boron nitride nanosheets (BNNSs). Four different sets of Tersoff potential parameters were used in the simulations for estimating the interatomic interactions between boron and nitrogen atoms. Modifications were incorporated in the Tersoff cut-off function to improve the accuracy of results with respect to fracture stress, fracture strain and Young’s modulus. In this study, the original cut-off function was optimised in such a way that small and large cut-off distances were made equal, and hence a single cut-off distance was used with all sets of Tersoff potential parameters. The single value of cut-off distance for the Tersoff potential was chosen after analysing the potential energy and bond forces experienced by boron and nitrogen atoms subjected to bond stretching. The simulations performed with the optimised cut-off function help in identifying the Tersoff potential parameters that reproduce the experimentally evaluated mechanical behaviour of BNNSs.

  19. Removal of methadone by extended dialysis using a high cut-off dialyzer: implications for the treatment of overdose and for pain management in patients undergoing light chain removal.

    PubMed

    Arelin, Viktor; Schmidt, Julius J; Kayser, Nathalie; Kühn-Velten, W Nikolaus; Suhling, Hendrik; Eden, Gabriele; Kielstein, Jan T

    2016-06-01

    The synthetic opioid methadone hydrochloride has a low molecular weight of 346 D, a high volume of distribution (4 - 7 L/kg), and is lipophilic. It is used as an analgesic and for the maintenance treatment of opiate dependence. In drug addicts, methadone is frequently involved in mixed intoxications that can lead to death. Here we present the case of a drug addict in whom a high cut-off dialysis membrane together with extended dialysis was used in the setting of suspected overdose and acute kidney injury. Although the observed dialyzer plasma clearance (31.5 mL/min) and reduction ratio (38%) were higher than previously reported for standard hemodialysis, the total amount of methadone in the spent dialysate after 1 extended dialysis session was quite low. Hence, even extended dialysis with a high cut-off membrane does not seem to offer a clinically relevant benefit in the setting of overdose for enhanced methadone removal. On the other hand, in patients undergoing high cut-off dialysis for the removal of light chains, methadone could still be used as an analgesic without an additional dose after high cut-off hemodialysis.

  20. Transaminase abnormalities and adaptations of the liver lobule manifest at specific cut-offs of steatosis

    PubMed Central

    Hall, Andrew; Covelli, Claudia; Manuguerra, Roberta; Luong, Tu Vinh; Buzzetti, Elena; Tsochatzis, Emmanuel; Pinzani, Massimo; Dhillon, Amar Paul

    2017-01-01

    There is little documented evidence suggesting that liver fat is responsible for liver injury in the absence of other disease processes. We investigated the relationships between liver fat, aminotransferases and hepatic architecture in liver biopsies with simple steatosis. We identified 136 biopsies with simple steatosis from the Royal Free Hospital Archives with both clinical data and sufficient material. Digital image analysis was employed to measure fat proportionate area (mFPA). Hepatocyte area (HA) and lobule radius (LR) were also measured. There were significant increases in ALT (p < 0.001) and AST (p = 0.013) with increased fat content and evidence to suggest both 5% and 20% mFPA as a cut-off for raised ALT. In liver with increased fat content there were significant increases in HA (p < 0.001). LR also increased as mFPA increased to 10% (p < 0.001), at which point the lobule ceased to expand further and was counterbalanced with a decrease in the number of hepatocytes per lobule (p = 0.029). Consequently there are mechanisms of adaption in the liver architecture to accommodate the accumulation of fat and these are accompanied by significant increases in transaminases. These results support the generally accepted cut-off of 5% fat for steatosis and indicate 20% as a threshold of more severe liver injury. PMID:28106158

  1. The effect of electron beams on cyclotron maser emission excited by lower-energy cutoffs

    NASA Astrophysics Data System (ADS)

    Zhao, G. Q.; Feng, H. Q.; Wu, D. J.

    2016-05-01

    Electron-cyclotron maser (ECM) is one of the most important emission mechanisms in astrophysics and can be excited efficiently by lower-energy cutoffs of power-law electrons. These non-thermal electrons probably propagate as a directed collimated beam along ambient magnetic fields. This paper investigates the ECM, in which the effect of electron beams is emphasized. Results show the dependence of emission properties of the ECM on the beam feature. The maximum growth rate of the extraordinary mode (X2) rapidly decreases as the beam momentum increases, while the growth rate of the ordinary mode (O1) changes slightly. In particular, the ordinary mode can overcome the extraordinary mode and becomes the fastest growth mode once the beam momentum is large enough. This research presents an extension of the conventional studies on ECM driven by lower-energy cutoffs and may be helpful to understand better the emission process of solar type I radio bursts, which are dominated by the ordinary mode emission.

  2. Excitation of parasitic waves near cutoff in forward-wave amplifiers

    SciTech Connect

    Nusinovich, Gregory S.; Sinitsyn, Oleksandr V.; Antonsen, Thomas M. Jr.

    2010-10-15

    In this paper, excitation of parasitic waves near cutoff in forward-wave amplifiers is studied in a rather general form. This problem is important for developing high-power sources of coherent, phase controlled short-wavelength electromagnetic radiation because just the waves which can be excited near cutoff have low group velocities. Since the wave coupling to an electron beam is inversely proportional to the group velocity, these waves are the most dangerous parasitic waves preventing stable amplification of desired signal waves. Two effects are analyzed in the paper. The first one is the effect of signal wave parameters on the self-excitation conditions of such parasitic waves. The second effect is the role of the beam geometry on excitation of these parasitic waves in forward-wave amplifiers with spatially extended interaction space, such as sheet-beam devices. It is shown that a large-amplitude signal wave can greatly influence the self-excitation conditions of the parasitic waves which define stability of operation. Therefore the effect described is important for accurate designing of high-power amplifiers of electromagnetic waves.

  3. Cut-Off Values of Visceral Adiposity to Predict NAFLD in Brazilian Obese Adolescents

    PubMed Central

    Grotti Clemente, Ana Paula; Molin Netto, Bárbara Dal; Ganen, Aline di Piano; Tock, Lian; Arisa Caranti, Danielle; de Mello, Marco Túlio; Tufik, Sergio; Dâmaso, Ana R.

    2013-01-01

    Objectives. The present study aimed at determining cut-off points of visceral fat to predict NAFLD and analyzed metabolic disorders of obese adolescents. Methods. Cross-sectional study involved 165 obese adolescents ranged in age from 15 to 19 years. Glycemia, hepatic transaminases, lipid profile, and insulin resistance were analyzed. Visceral and subcutaneous fat were measured by ultrasound and body composition by plesthysmography. Results. The NAFLD adolescents had significantly higher values for body mass, BMI-for-age, BMI, total fat, waist circumference, and visceral fat when compared with non-NAFLD obese adolescents in both genders. Moreover, there were significant positive correlations between visceral fat with the variables BMI-for-age (r = 0.325,), TG (r = 0.277), AST (r = 0.509), ALT (r = 0.519), WC (r = 0.390), and visceral/subcutaneous ratio (r = 0.790) for NAFLD group. Total fat, triglycerides, and visceral fat were the independent predictors to NAFLD. Analysis of the ROC curves revealed cut-off points of visceral fat of 4.47 cm for girls and 4.21 cm for boys. Conclusions. The results may suggest that abdominal ultrasonography procedure may be a safe alternative method of assessing visceral adiposity aiming to be considered to the development of preventive and treatment strategies in obese individuals. This clinial trial is registered with ClinicalTrial.gov (NCT01358773). PMID:24381750

  4. NSVS4484038, A contact binary system at the short-period cutoff

    SciTech Connect

    Zhang, X. B.; Deng, L. C.; Wang, K.; Yan, Z. Z.; Tian, J. F.; Peng, Y. J.; Pan, Y.; Luo, Z. Q.; Sun, J. J.; Liu, Q. L.; Xin, H. Q.; Zhou, Q.

    2014-09-01

    We present a photometric study of the short-period eclipsing binary NSVS4484038. Time-series CCD photometry of the star in the B and V band was carried out. An orbital period of 0.218551 days was determined for the eclipsing binary and a revised linear ephemeris was given. The first photometric solution of the binary system was detected through light-curve synthesis using the Wilson-Devinney method. It reveals an overcontact configuration for the system with a filling-out factor of about 10%. The mass ratio was determined to be 2.74 with an inclination of 72.°1. The less massive secondary component is found to have a higher surface temperature than the primary by about 90 K, indicating that NSVS4484038 could be a contact system of W subtype. The star is then identified to be a new member of W UMa systems at the short-period cutoff. Comparisons with known contact binaries at the short-period cutoff, the properties, and the evolutionary status of the binary system are discussed.

  5. Using whole-genome sequencing to determine appropriate streptomycin epidemiological cutoffs for Salmonella and Escherichia coli.

    PubMed

    Tyson, Gregory H; Li, Cong; Ayers, Sherry; McDermott, Patrick F; Zhao, Shaohua

    2016-02-01

    For Enterobacteriaceae such as Salmonella spp. and Escherichia coli, no unified interpretive resistance criteria exist for streptomycin, an epidemiologically important antibiotic. As part of the National Antimicrobial Resistance Monitoring System, we had previously used a minimum inhibitory concentration of ≥ 64 μg mL(-1) as an epidemiological cutoff value (ECV) to define non-wild-type isolates. To identify whether this ECV correlated with genetic determinants of resistance, we performed whole-genome sequencing of 463 Salmonella and E. coli isolates to identify streptomycin resistance genotypes. From this analysis, we found that using a streptomycin resistance breakpoint of ≥ 64 μg mL(-1) classified over 20% of strains possessing aadA or strA/strB resistance genes as wild-type. Therefore, to improve the concordance between genotypic and phenotypic data, we propose reducing the phenotypic cutoff values to ≥ 32 μg mL(-1) for both Salmonella and E. coli, to be used widely as ECVs to categorize non-wild-type isolates.

  6. Migration and cutoff of meanders in the hyperarid environment of the middle Tarim River, northwestern China

    NASA Astrophysics Data System (ADS)

    Li, Zhiwei; Yu, Guo-An; Brierley, Gary John; Wang, Zhaoyin; Jia, Yanhong

    2017-01-01

    A meandering channel has developed in the middle Tarim River, the longest inland river flowing through a hyperarid environment in northwestern China. Although the drainage basin of the Tarim River extends over 1 million km2, flow in downstream reaches is largely restricted to summer months, and irrigation pressures have made the flood season increasingly short. The planform morphology, lateral migration rate, and cutoffs of 105 meanders were analysed using multiperiod remote sensing images and field survey analyses of channel bed and bank properties and of riparian vegetation cover. Results show that planform attributes of the meandering Tarim River are similar to those found in other environments. The ratio of the channel centreline length to the neck channel width of meanders ranges between 1.2 and 8.1, the bend curvature (ratio of bend radius to channel width) ranges between 0.30 and 2.8, and the average deflection angle of the bend apexes is 79.9°. Meander migration rates range from 1.4 to 96.7 m y- 1. From 2000 to 2013, 45 cutoffs occurred along the 400-km-long reach. As the riparian vegetation cover is sparse because of limited precipitation and because banks are comprised of dense roots, fine sand and silt materials, but lack clay, bank strength is limited and presents limited constraints upon bend movement.

  7. Cutoff frequency of sound velocities for a multi-slab Bose-Einstein condensate

    NASA Astrophysics Data System (ADS)

    Rodríguez, O. A.; Solís, M. A.

    2015-03-01

    An inhomogeneous multi-slab 3D Bose gas is produced by applying to the gas a Kronig-Penney potential in one direction, while the bosons are free to move in the other two directions. The variable density produces a dispersive effect over the sound waves, making the phase and group sound velocities frequency dependent. Below the critical temperature the dispersion relation between wavenumber and frequency ω (k) is determined by a constant factor called the curvature of the density, within the Klein-Gordon equation which describes the sound wave propagation in the condensate. Since the curvature of the density profiles between and inside the barriers are completely different, the sound velocities are distinct too. More importantly, in the region occupied by the slabs waves propagate only if their frequencies are greater than a cutoff frequency, otherwise evanescent waves arise. We show the density profile, the phase and group sound velocities and we give the curvature dependent cutoff frequency as obtained from the group velocity equation for the region occupied by the barriers. For high frequencies both phase and group velocities approach to that of a homogeneous gas at the same temperature. We acknowledge partial support from PAPIIT IN111613.

  8. Characterization of thermal cut-off mechanisms in prismatic lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Venugopal, Ganesh

    Lithium-ion (Li-ion) cells that are subjected to electrical abuse, overcharge and external short-circuit in particular, exhibit a rapid increase in cell temperature that could potentially lead to catastrophic disassembly of the cell. For this reason these cells are integrated or combined with one or more safety components that are designed to restrict or even prevent current flow through the cell under abusive conditions. In this work, the characteristics of these components in several prismatic Li-ion cells are studied by monitoring the impedance ( Z) at 1 kHz and the open circuit voltage (OCV) of the discharged cells as a function of temperature. All the cells studied were found to use polyethylene-based shutdown (SD) separators that were irreversibly activated within a narrow temperature range between 130 and 135°C. In some cells irreversible cut-off was also provided by a current interrupt device (CID) or a thermal fuse. Both these devices had a circuit-breaker effect, causing the impedance of the cell to rise infinitely and the OCV to drop to zero. In addition to these irreversible cut-off mechanisms, some cells also contained internal or external positive-temperature-coefficient (PTC) devices that could provide current-limiting capability over a very wide temperature range. The interdependence of the thermal behavior of these components on each other and on other thermally dependant processes like cell venting, separator meltdown and weld joint failure are also discussed.

  9. High density quark matter in the Nambu-Jona-Lasinio model with dimensional versus cutoff regularization

    SciTech Connect

    Fujihara, T.; Kimura, D.; Inagaki, T.; Kvinikhidze, A.

    2009-05-01

    We investigate color superconducting phase at high density in the extended Nambu-Jona-Lasinio model for two-flavor quarks. Because of the nonrenormalizability of the model, physical observables may depend on the regularization procedure; that is why we apply two types of regularization, the cutoff and the dimensional one to evaluate the phase structure, the equation of state, and the relationship between the mass and the radius of a dense star. To obtain the phase structure we evaluate the minimum of the effective potential at finite temperature and chemical potential. The stress tensor is calculated to derive the equation of state. Solving the Tolman-Oppenheimer-Volkoff equation, we show the relationship between the mass and the radius of a dense star. The dependence on the regularization is found not to be small, interestingly. The dimensional regularization predicts color superconductivity phase at rather large values of {mu} (in agreement with perturbative QCD in contrast to the cutoff regularization), in the larger temperature interval, the existence of heavier and larger quark stars.

  10. Effects of Cutoffs on Galactic Cosmic-Ray Interactions in Solar-System Matter

    NASA Technical Reports Server (NTRS)

    Kim, K. J.; Reedy, R. C.; Masarik, J.

    2005-01-01

    The energetic particles in the galactic cosmic rays (GCR) induce many interactions in a variety of solar-system matter. Cosmogenic nuclides are used to study the histories of meteorites and lunar samples. Gamma rays and neutrons are used to map the compositions of planetary surfaces, such as Mars, the Moon, and asteroids. In almost all of these cases, the spectra of incident GCR particles are fairly similar, with only some modulation by the Sun over an 11-year cycle. Strong magnetic fields can seriously affect the energy spectrum of GCR particles hitting the surface of objects inside the magnetic fields. The Earth s geomagnetic field is strong enough that only GCR particles with magnetic rigidities above approx. 17 GV (a proton energy of approx. 17 GeV) reach the atmosphere over certain regions near the equator. This effect of removing lower-energy GCR particles is called a cutoff. The jovian magnetic fields are so strong that the fluxes of GCR particles hitting the 4 large Galilean satellites are similarly affected. The cutoff at Europa is estimated to be similar to or a little higher than at the Earth s equator.

  11. Extension of harmonic cutoff in a multicycle chirped pulse combined with a chirp-free pulse

    SciTech Connect

    Xu Junjie; Zeng Bin; Yu Yongli

    2010-11-15

    We demonstrate high-order harmonic generation in a wave form synthesized by a multicycle 800-nm chirped laser pulse and a chirp-free laser pulse. Compared with the case of using only a chirped pulse, both the harmonic cutoff and the extreme ultraviolet supercontinuum can be extended when a weak chirp-free pulse is combined with the chirped pulse. When chirp-free pulse intensity grows, the cutoff energy and bandwidth of the supercontinuum grow as well. It is found that the broad supercontinuum can be achieved for a driving pulse with long duration even though the driving pulse reaches 10 optical cycles. An isolated attosecond pulse with duration of about 59 as is obtained, and after appropriate phase compensation with a duration of about 11 as. In addition, by performing time-frequency analyses and the classical trajectory simulation, the difference in supercontinuum generation between the preceding wave form and a similar wave form synthesized by an 800-nm fundamental pulse and a 1600-nm subharmonic pulse is investigated.

  12. Cutoff Point of HbA1c for Diagnosis of Diabetes Mellitus in Chinese Individuals

    PubMed Central

    Liu, Ming-Chuan; Li, Xin-Yu; Liu, Xu-Han; Feng, Qiu-Xia; Lu, Lu; Zhu, Zhu; Liu, Ying-Shu; Zhao, Wei; Gao, Zheng-Nan

    2016-01-01

    Background The purpose of the present study was to find the optimal threshold of glycated hemoglobin (HbA1c) for diagnosis of diabetes mellitus in Chinese individuals. Methods A total of 8 391 subjects (including 2 133 men and 6 258 women) aged 40–90 years with gradable retinal photographs were recruited. The relationship between HbA1c and diabetic retinopathy (DR) was examined. Receiver operating characteristic (ROC) curves were used to find the optimal threshold of HbA1c in screening DR and diagnosing diabetes. Results HbA1c values in patients with DR were significantly higher than in those with no DR. The ROC curve for HbA1c had an area under the curve of 0.881 (95%CI 0.857–0.905; P = 0.000). HbA1c at a cutoff of 6.5% had a high sensitivity (80.6%) and specificity (86.9%) for detecting DR. Conclusions HbA1c can be used to diagnose diabetes in a Chinese population, and the optimal HbA1c cutoff point for diagnosis is 6.5%. PMID:27861599

  13. Determination of cutoff frequencies of simple waveguides using finite difference method

    NASA Astrophysics Data System (ADS)

    Kolagani, Sridhar

    Waveguides are used to transfer electromagnetic energy from one location to another. Within many electronic circles, waveguides are commonly used for microwave RF signals; the same principle can be used for many forms of waves from sound to light. They have been used in many technologies like acoustic waveguide speaker technology, high-performance passive waveguide technologies for remote sensing and communication, optical computing, robotic-vision, biochemical sensing and many more. Modern waveguide technology employs a variety of waveguides with different cross sections and perturbations, the cutoff frequencies and mode shapes of many of these waveguides are ill-suited for determination by an analytical method. In this thesis, we solve this type of waveguides by employing the numerical procedure of finite difference method. By adopting finite difference approach with an application of eigenvalue method, we discuss about few different types of these waveguides in determining the cutoff frequencies of supported modes, and extracting the possible degenerate modes and their field distributions. To validate the method and its accuracy, it is applied to the two well known rectangular waveguides, viz. PEC Rectangular Waveguide and Artificial Rectangular Waveguide (consists of PEC and PMC walls) and compared with the analytical solutions.

  14. Design Dependent Cutoff Frequency of Nanotransistors Near the Ultimate Performance Limit

    NASA Astrophysics Data System (ADS)

    Kordrostami, Zoheir; Sheikhi, M. Hossein; Zarifkar, Abbas

    2012-12-01

    We have studied the effect of different structural designs of double gate MOSFETs (DG-MOSFETs) and carbon nanotube field effect transistors (CNTFETs) on the cutoff frequency (fT). The effects of metallic contacts with Schottky barriers, gate work function, dual material gate (DMG), halo doped channel and lightly doped drain and source (LDDS) architectures on the fT have been investigated for DG-MOSFETs and CNTFETs and the design dependent fT for both types of transistors has been studied for the first time. The simulations are based on the Schrödinger-Poisson solvers developed for each nanotransistor separately. The ballistic limit has been studied as the ultimate performance limit of the DG-MOSFETs and CNTFETs. The results of this paper, for the first time, show how some designations used for modification of short channel effects or current-voltage characteristics affect the fT. The results revealed that the cutoff frequencies of both types of the transistors exhibit the same behavior with changing design parameters. We have shown that the Schottky barriers, parasitic capacitances and halo doping reduce the fT and have proposed the DMG and LDDS artchitectures as ways to increase the fT for DG-MOSFETs and CNTFETs for the first time.

  15. Gravitational-wave cutoff frequencies of tidally disruptive neutron star-black hole binary mergers

    NASA Astrophysics Data System (ADS)

    Pannarale, Francesco; Berti, Emanuele; Kyutoku, Koutarou; Lackey, Benjamin D.; Shibata, Masaru

    2015-10-01

    Tidal disruption has a dramatic impact on the outcome of neutron star-black hole mergers. The phenomenology of these systems can be divided in three classes: nondisruptive, mildly disruptive, and disruptive. The cutoff frequency of the gravitational radiation produced during the merger (which is potentially measurable by interferometric detectors) is very different in each regime, and when the merger is disruptive it carries information on the neutron star equation of state. Here we use semianalytical tools to derive a formula for the critical binary mass ratio Q =MBH/MNS below which mergers are disruptive as a function of the stellar compactness C =MNS/RNS and the dimensionless black hole spin χ . We then employ a new gravitational waveform amplitude model, calibrated to 134 general relativistic numerical simulations of binaries with black hole spin (anti-)aligned with the orbital angular momentum, to obtain a fit to the gravitational-wave cutoff frequency in the disruptive regime as a function of C , Q , and χ . Our findings are important to build gravitational-wave template banks, to determine whether neutron star-black hole mergers can emit electromagnetic radiation (thus helping multimessenger searches), and to improve event rate calculations for these systems.

  16. Usefulness of the CAPE-P15 for detecting people at ultra-high risk for psychosis: Psychometric properties and cut-off values.

    PubMed

    Bukenaite, Akvile; Stochl, Jan; Mossaheb, Nilufar; Schäfer, Miriam R; Klier, Claudia M; Becker, Jana; Schloegelhofer, Monika; Papageorgiou, Konstantinos; Montejo, Angel L; Russo, Debra A; Jones, Peter B; Perez, Jesus; Amminger, G Paul

    2017-02-26

    A need for a brief, easy to complete self-report questionnaire to detect people at ultra-high risk for psychosis (UHR) in busy clinical settings has been recognised. Our aim was to explore whether the Community Assessment of Psychic Experiences - Positive 15-items Scale (CAPE-P15) could be used as a screening tool to identify people at UHR in a clinical setting. Our objectives were to confirm the CAPE-P15 factorial structure as well as its reliability and determine cut-off values for the detection of such individuals using the Comprehensive Assessment of At-Risk Mental States (CAARMS), a commonly used clinical interview for the detection of UHR. 165 participants aged between 13 and 18 referred to the General Hospital of Vienna were included in the analysis. 50.9% of the sample were "CAARMS-positive" and 49.1% "CAARMS-negative". The Youden method determined CAPE-P15 cut-off values for UHR detection of 1.47 for both frequency of and distress associated with psychotic experiences. The cut-off value of 1.47 for frequency showed sensitivity of 77%, specificity of 58%, a positive predictive value of 66% and a negative predictive value of 71%; whilst for distress it showed sensitivity of 73%, specificity of 63%, a positive predictive value of 69% and a negative predictive value of 66%. Good reliability and the previously suggested three-correlated factor model as well as an alternative bi-factor model of the CAPE-P15 were confirmed. The CAPE-P15 seems to be a promising screening tool for identifying people who might be at UHR in busy clinical settings.

  17. DAS28-CRP and DAS28-ESR cut-offs for high disease activity in rheumatoid arthritis are not interchangeable

    PubMed Central

    Fleischmann, Roy M; van der Heijde, Désirée; Gardiner, Philip V; Szumski, Annette; Marshall, Lisa; Bananis, Eustratios

    2017-01-01

    Background In most patients with rheumatoid arthritis (RA), Disease Activity Score 28-joint count C reactive protein (DAS28-CRP) is lower than DAS28 erythrocyte sedimentation rate (DAS28-ESR), suggesting that use of the DAS28-ESR cut-off to assess high disease activity (HDA) with DAS28-CRP may underestimate the number of patients with HDA. We determined the DAS28-CRP value corresponding to the validated DAS28-ESR cut-off for HDA. Methods Baseline data were pooled from 2 clinical studies evaluating etanercept (ETN) plus methotrexate (MTX) or MTX in early RA; DAS28-CRP and DAS28-ESR were obtained, allowing the determination of the DAS28-CRP HDA value best corresponding to the DAS28-ESR cut-off of >5.1. Results At baseline, as expected, fewer patients had HDA by DAS28-CRP than DAS28-ESR; DAS28-CRP>5.1 and DAS28-ESR>5.1 had only modest agreement (κ coefficients 0.45–0.54). Mean DAS28-CRP and DAS28-ESR were 5.7 and 6.2, respectively, in the ETN+MTX group (n=571), and 6.0 and 6.5 in the MTX group (n=262). A DAS28-CRP cut-off of 4.6 corresponded to a DAS28-ESR cut-off of 5.1. Conclusions We have shown that a DAS28-CRP of 4.6 corresponds to 5.1 for DAS28-ESR. Since this is substantially lower than the DAS28-ESR cut-off of 5.1, using 5.1 as the cut-off for DAS28-CRP underestimates disease activity in RA. Trial registration number NCT00195494; NCT00913458. PMID:28255449

  18. A cutoff phenomenon in accelerated stochastic simulations of chemical kinetics via flow averaging (FLAVOR-SSA)

    NASA Astrophysics Data System (ADS)

    Bayati, Basil; Owhadi, Houman; Koumoutsakos, Petros

    2010-12-01

    We present a simple algorithm for the simulation of stiff, discrete-space, continuous-time Markov processes. The algorithm is based on the concept of flow averaging for the integration of stiff ordinary and stochastic differential equations and ultimately leads to a straightforward variation of the the well-known stochastic simulation algorithm (SSA). The speedup that can be achieved by the present algorithm [flow averaging integrator SSA (FLAVOR-SSA)] over the classical SSA comes naturally at the expense of its accuracy. The error of the proposed method exhibits a cutoff phenomenon as a function of its speed-up, allowing for optimal tuning. Two numerical examples from chemical kinetics are provided to illustrate the efficiency of the method.

  19. A cutoff phenomenon in accelerated stochastic simulations of chemical kinetics via flow averaging (FLAVOR-SSA).

    PubMed

    Bayati, Basil; Owhadi, Houman; Koumoutsakos, Petros

    2010-12-28

    We present a simple algorithm for the simulation of stiff, discrete-space, continuous-time Markov processes. The algorithm is based on the concept of flow averaging for the integration of stiff ordinary and stochastic differential equations and ultimately leads to a straightforward variation of the the well-known stochastic simulation algorithm (SSA). The speedup that can be achieved by the present algorithm [flow averaging integrator SSA (FLAVOR-SSA)] over the classical SSA comes naturally at the expense of its accuracy. The error of the proposed method exhibits a cutoff phenomenon as a function of its speed-up, allowing for optimal tuning. Two numerical examples from chemical kinetics are provided to illustrate the efficiency of the method.

  20. Distribution of {Omega}{sub k} from the scale-factor cutoff measure

    SciTech Connect

    De Simone, Andrea; Salem, Michael P.

    2010-04-15

    Our Universe may be contained in one among a diverging number of bubbles that nucleate within an eternally inflating multiverse. A promising measure to regulate the diverging spacetime volume of such a multiverse is the scale-factor cutoff, one feature of which is bubbles are not rewarded for having a longer duration of slow-roll inflation. Thus, depending on the landscape distribution of the number of e-folds of inflation among bubbles like ours, we might hope to measure spatial curvature. We study a recently proposed cartoon model of inflation in the landscape and find a reasonable chance (about 10%) that the curvature in our Universe is well above the value expected from cosmic variance. Anthropic selection does not strongly select for curvature as small as is observed (relative somewhat larger values), meaning the observational bound on curvature can be used to rule out landscape models that typically give too little inflation.

  1. Arctic Cut-Off High Drives the Poleward Shift of a New Greenland Melting Record

    NASA Technical Reports Server (NTRS)

    Tedesco, M.; Mote, T.; Fettweis, X.; Hanna, E.; Jeyaratnam, J.; Booth, J. F.; Datta, R.; Briggs, K.

    2016-01-01

    Large-scale atmospheric circulation controls the mass and energy balance of the Greenland ice sheet through its impact on radiative budget, runoff and accumulation. Here, using reanalysis data and the outputs of a regional climate model, we show that the persistence of an exceptional atmospheric ridge, centered over the Arctic Ocean, was responsible for a poleward shift of runoff, albedo and surface temperature records over the Greenland during the summer of 2015. New records of monthly mean zonal winds at 500 hPa and of the maximum latitude of ridge peaks of the 5,700+/-50 m isohypse over the Arctic were associated with the formation and persistency of a cutoff high. The unprecedented (1948-2015) and sustained atmospheric conditions promoted enhanced runoff, increased the surface temperatures and decreased the albedo in northern Greenland, while inhibiting melting in the south, where new melting records were set over the past decade. Subject terms: Earth sciences Atmospheric science Climate science

  2. From Newton's Law to the Linear Boltzmann Equation Without Cut-Off

    NASA Astrophysics Data System (ADS)

    Ayi, Nathalie

    2017-03-01

    We provide a rigorous derivation of the linear Boltzmann equation without cut-off starting from a system of particles interacting via a potential with infinite range as the number of particles N goes to infinity under the Boltzmann-Grad scaling. More particularly, we will describe the motion of a tagged particle in a gas close to global equilibrium. The main difficulty in our context is that, due to the infinite range of the potential, a non-integrable singularity appears in the angular collision kernel, making no longer valid the single-use of Lanford's strategy. Our proof relies then on a combination of Lanford's strategy, of tools developed recently by Bodineau, Gallagher and Saint-Raymond to study the collision process, and of new duality arguments to study the additional terms associated with the long-range interaction, leading to some explicit weak estimates.

  3. Determination of the shape factor of (90)Sr by means of the cutoff energy yield method.

    PubMed

    Grau Carles, A; Kossert, K; Grau Malonda, A

    2008-01-01

    Usually, Kurie plots are used to analyze beta-spectra shape-factor functions measured by means of semiconductor and magnetic spectrometers. A drawback of these techniques is the occurrence of self-absorption within the samples through which the emission spectrum is altered. In liquid-scintillation samples self-absorption does not occur, but the poor energy resolution makes the analysis of the spectra difficult. To overcome this problem, two resolution-invariant observables are used for determining the shape-factor function of (90)Sr: (1) the maximum point energy and (2) the cutoff energy yield. The measured shape-factor function of (90)Sr agrees with the one which is predicted by theory for the first-forbidden unique transition.

  4. Arctic cut-off high drives the poleward shift of a new Greenland melting record.

    PubMed

    Tedesco, M; Mote, T; Fettweis, X; Hanna, E; Jeyaratnam, J; Booth, J F; Datta, R; Briggs, K

    2016-06-09

    Large-scale atmospheric circulation controls the mass and energy balance of the Greenland ice sheet through its impact on radiative budget, runoff and accumulation. Here, using reanalysis data and the outputs of a regional climate model, we show that the persistence of an exceptional atmospheric ridge, centred over the Arctic Ocean, was responsible for a poleward shift of runoff, albedo and surface temperature records over the Greenland during the summer of 2015. New records of monthly mean zonal winds at 500 hPa and of the maximum latitude of ridge peaks of the 5,700±50 m isohypse over the Arctic were associated with the formation and persistency of a cutoff high. The unprecedented (1948-2015) and sustained atmospheric conditions promoted enhanced runoff, increased the surface temperatures and decreased the albedo in northern Greenland, while inhibiting melting in the south, where new melting records were set over the past decade.

  5. Arctic cut-off high drives the poleward shift of a new Greenland melting record

    NASA Astrophysics Data System (ADS)

    Tedesco, M.; Mote, T.; Fettweis, X.; Hanna, E.; Jeyaratnam, J.; Booth, J. F.; Datta, R.; Briggs, K.

    2016-06-01

    Large-scale atmospheric circulation controls the mass and energy balance of the Greenland ice sheet through its impact on radiative budget, runoff and accumulation. Here, using reanalysis data and the outputs of a regional climate model, we show that the persistence of an exceptional atmospheric ridge, centred over the Arctic Ocean, was responsible for a poleward shift of runoff, albedo and surface temperature records over the Greenland during the summer of 2015. New records of monthly mean zonal winds at 500 hPa and of the maximum latitude of ridge peaks of the 5,700+/-50 m isohypse over the Arctic were associated with the formation and persistency of a cutoff high. The unprecedented (1948-2015) and sustained atmospheric conditions promoted enhanced runoff, increased the surface temperatures and decreased the albedo in northern Greenland, while inhibiting melting in the south, where new melting records were set over the past decade.

  6. Extraordinary transmission beyond the cut-off through sub- λ annular aperture arrays

    NASA Astrophysics Data System (ADS)

    Baida, Fadi I.; Poujet, Yannick; Salvi, Jérôme; Labeke, Daniel Van; Guizal, Brahim

    2009-04-01

    It was recently established that coaxial nano-aperture arrays perforated in optically thick silver films exhibit an extraordinary transmission in the visible range thanks to a guided mode. However this mode has a cut-off wavelength beyond which the transmission dramatically decreases. We propose here a cascaded structure that is shown to act as a high quality spectral filter in the visible range (finesse up to 200). It is also found that the transmission is enhanced by a factor of 150 for specific wavelengths. This kind of cascaded nano-structured metallic layers offers many promising applications in nano-photonics such as the integration of functionalities for optical signal processing. It opens up the path for the conception of a new generation of integrated components based on metallo-dielectric structures that can be easily tailored as tunable devices.

  7. Arctic cut-off high drives the poleward shift of a new Greenland melting record

    PubMed Central

    Tedesco, M.; Mote, T.; Fettweis, X.; Hanna, E.; Jeyaratnam, J.; Booth, J. F.; Datta, R.; Briggs, K.

    2016-01-01

    Large-scale atmospheric circulation controls the mass and energy balance of the Greenland ice sheet through its impact on radiative budget, runoff and accumulation. Here, using reanalysis data and the outputs of a regional climate model, we show that the persistence of an exceptional atmospheric ridge, centred over the Arctic Ocean, was responsible for a poleward shift of runoff, albedo and surface temperature records over the Greenland during the summer of 2015. New records of monthly mean zonal winds at 500 hPa and of the maximum latitude of ridge peaks of the 5,700±50 m isohypse over the Arctic were associated with the formation and persistency of a cutoff high. The unprecedented (1948–2015) and sustained atmospheric conditions promoted enhanced runoff, increased the surface temperatures and decreased the albedo in northern Greenland, while inhibiting melting in the south, where new melting records were set over the past decade. PMID:27277547

  8. Viscous holographic dark energy universe with Nojiri-Odintsov cut-off

    NASA Astrophysics Data System (ADS)

    Khurshudyan, Martiros

    2016-12-01

    In this paper we consider a toy model of large scale universe, when one of the dark components is a generalized holographic DE with a Nojiri-Odintsov cut-off. On the other hand, we made another assumption concerning to the companion of considered DE model due to impossibility of exact parameterization of dark side of the large scale universe. In particular, we assume an inhomogeneous viscous dark fluid discussed in literature very actively, to be possible candidate for the companion. In addition to cosmographic analysis we discuss the results from Om and two point Om analysis and estimated present day values of statefinder parameters (r,s) and (ω^' }_{de}, ω_{de}). Moreover, validity of generalized second law of thermodynamics is studied showing that theoretical results are well consistent with observational data. Constraints on cosmological parameters are due to Planck 2015 experiments.

  9. From Newton's Law to the Linear Boltzmann Equation Without Cut-Off

    NASA Astrophysics Data System (ADS)

    Ayi, Nathalie

    2017-01-01

    We provide a rigorous derivation of the linear Boltzmann equation without cut-off starting from a system of particles interacting via a potential with infinite range as the number of particles N goes to infinity under the Boltzmann-Grad scaling. More particularly, we will describe the motion of a tagged particle in a gas close to global equilibrium. The main difficulty in our context is that, due to the infinite range of the potential, a non-integrable singularity appears in the angular collision kernel, making no longer valid the single-use of Lanford's strategy. Our proof relies then on a combination of Lanford's strategy, of tools developed recently by Bodineau, Gallagher and Saint-Raymond to study the collision process, and of new duality arguments to study the additional terms associated with the long-range interaction, leading to some explicit weak estimates.

  10. DETERMINATION OF LOW-ENERGY CUTOFFS AND TOTAL ENERGY OF NONTHERMAL ELECTRONS IN A SOLAR FLARE ON 2002 APRIL 15

    NASA Technical Reports Server (NTRS)

    Sui, Linhui; Holman, Gordon D.; Dennis, Brian R.

    2005-01-01

    The determination of the low-energy cutoff to the spectrum of accelerated electrons is decisive for the estimation of the total nonthermal energy in solar flares. Because thermal bremsstrahlung dominates the low-energy part of flare X-ray spectra, this cutoff energy is difficult to determine with spectral fitting alone. We have used anew method that combines spatial, spectral, and temporal analysis to determine the cutoff energy for the M1.2 flare observed with RHESSI on 2002 April 15. A low-energy cutoff of 24 +/- 2 keV is required to ensure that the assumed thermal emissions always dominate over nonthermal emissions at low energies (<20 keV) and that the spectral fitting results are consistent with the RHESSI light curves and images. With this cutoff energy, we obtain a total nonthermal energy in electrons of (1.6 +/- 1) x 10(exp 30) ergs that is comparable to the peak energy in the thermal plasma, estimated from RHESSI observations to be (6 +/- 0.6) x 10(exp 29) ergs assuming a filling factor of 1.

  11. The Cut-off Values of Triglycerides and Glucose Index for Metabolic Syndrome in American and Korean Adolescents

    PubMed Central

    2017-01-01

    The aim of this study was to establish ethnic- and gender-specific cut-off values of triglycerides and glucose index (TyG index) for clinical usefulness in a representative sample of Mexican American, Non-Hispanic White, Non-Hispanic Black, and Korean adolescents. The data were collected from datasets of the National Health and Nutrition Examination Survey between 1999 and 2012, and the Korean National Health and Nutrition Examination Survey between 2005 and 2013. Receiver operating characteristic curve analysis was used to find valid cut-off values of the TyG index for metabolic syndrome. The total number of eligible participants was 3,164 in the US and 4,873 in Korea. The optimal cut-off value with the Cook et al. definition revealed 8.55 in Mexican American, 8.55 in Non-Hispanic White, 8.35 in Non-Hispanic Black, and 8.45 in Korean, respectively. The cut-off value with the de Ferranti et al. definition was 8.45, 8.45, 8.15, and 8.35, and the cut-off value with the International Diabetes Federation definition was 8.65, 8.65, 8.15, and 8.55, respectively. These findings may be clinically useful for evaluating insulin resistance for determining metabolic abnormalities in adolescents. PMID:28145645

  12. Cut-off characterisation of energy spectra of bright fermi sources: Current instrument limits and future possibilities

    NASA Astrophysics Data System (ADS)

    Romoli, C.; Taylor, A. M.; Aharonian, F.

    2017-02-01

    In this paper some of the brightest GeV sources observed by the Fermi-LAT were analysed, focusing on their spectral cut-off region. The sources chosen for this investigation were the brightest blazar flares of 3C 454.3 and 3C 279 and the Vela pulsar with a reanalysis with the latest Fermi-LAT software. For the study of the spectral cut-off we first explored the Vela pulsar spectrum, whose statistics in the time interval of the 3FGL catalog allowed strong constraints to be obtained on the parameters. We subsequently performed a new analysis of the flaring blazar SEDs. For these sources we obtained constraints on the cut-off parameters under the assumption that their underlying spectral distribution is described by a power-law with a stretched exponential cut-off. We then highlighted the significant potential improvements on such constraints by observations with next generation ground based Cherenkov telescopes, represented in our study by the Cherenkov Telescope Array (CTA). Adopting currently available simulations for this future observatory, we demonstrate the considerable improvement in cut-off constraints achievable by observations with this new instrument when compared with that achievable by satellite observations.

  13. The Cut-off Values of Triglycerides and Glucose Index for Metabolic Syndrome in American and Korean Adolescents.

    PubMed

    Moon, Shinje; Park, Joon Sung; Ahn, Youhern

    2017-03-01

    The aim of this study was to establish ethnic- and gender-specific cut-off values of triglycerides and glucose index (TyG index) for clinical usefulness in a representative sample of Mexican American, Non-Hispanic White, Non-Hispanic Black, and Korean adolescents. The data were collected from datasets of the National Health and Nutrition Examination Survey between 1999 and 2012, and the Korean National Health and Nutrition Examination Survey between 2005 and 2013. Receiver operating characteristic curve analysis was used to find valid cut-off values of the TyG index for metabolic syndrome. The total number of eligible participants was 3,164 in the US and 4,873 in Korea. The optimal cut-off value with the Cook et al. definition revealed 8.55 in Mexican American, 8.55 in Non-Hispanic White, 8.35 in Non-Hispanic Black, and 8.45 in Korean, respectively. The cut-off value with the de Ferranti et al. definition was 8.45, 8.45, 8.15, and 8.35, and the cut-off value with the International Diabetes Federation definition was 8.65, 8.65, 8.15, and 8.55, respectively. These findings may be clinically useful for evaluating insulin resistance for determining metabolic abnormalities in adolescents.

  14. Holographic dark energy in the DGP braneworld with Granda-Oliveros cutoff

    NASA Astrophysics Data System (ADS)

    Ghaffari, S.; Dehghani, M. H.; Sheykhi, A.

    2014-06-01

    We consider the holographic dark energy (HDE) model in the framework of the DGP braneworld with Granda-Oliveros infrared (IR) cutoff, L =(αH˙+βH2)-1/2. With this choice for IR cutoff, we are able to derive evolution of the cosmological parameters such as the equation of state and the deceleration parameters, w and q, as the functions of the redshift parameter z. As far as we know, most previous models of HDE presented in the literature, do not give analytically ω =ω(z) and q=q(z). We plot the evolution of these parameters versus z and discuss that the results are compatible with the recent observations. With suitably choosing the parameters, this model can exhibit a transition from deceleration to the acceleration around z≈0.6. Then we suggest a correspondence between the quintessence and tachyon scalar fields and HDE in the framework of the DGP braneworld. This correspondence allows us to reconstruct the evolution of the scalar fields and the scalar potentials. We also investigate the stability of the presented model by calculating the squared sound speed, vs2, whose sign determines the stability of the model. Our study shows that vs2 could be positive provided the parameters of the model are chosen suitably. In particular, for α>1, β>0, and α<1, β<0, we have vs2>0 during the history of the Universe, and so the stable dark-energy-dominated universe can be achieved. This is in contrast to the HDE in standard cosmology, which is unstable against background perturbations and so cannot lead to a stable dark- energy-dominated universe.

  15. High performance type II superlattice focal plane array with 6μm cutoff wavelength

    NASA Astrophysics Data System (ADS)

    Miura, Kouhei; Machinaga, Ken-ichi; Balasekaran, Sundararajan; Kawahara, Takahiko; Migita, Masaki; Inada, Hiroshi; Iguchi, Yasuhiro; Sakai, Michito; Murooka, Junpei; Katayama, Haruyoshi; Kimata, Masafumi

    2016-05-01

    The cutoff wavelength of 6μm is preferable for the full usage of the atmospheric window in the mid-wavelength region. An InAs/GaSb type-II superlattice (T2SL) is the only known infrared material that has a theoretically predicted high performance and also the cutoff wavelength can be easily controlled by changing the thickness of InAs and GaSb. In this study, we used a p-i-n structure with InAs/GaSb T2SL absorber and also barrier layers which was grown on a Tedoped GaSb substrate by molecular beam epitaxy. A mesa-type focal plane array (FPA) with 320×256 pixels and 30μm pixel pitch was fabricated. Mesa structures were formed by inductively coupled plasma reactive ion etching with halogen gas mixture. Prior to the deposition of the SiO2 passivation film, N2 plasma treatment was applied for reducing the dark currents. Measured dark current of the sensor was 4x10-7A/cm2 at temperature of 77K and reverse bias of -20mV. The quantum efficiency was 0.35 and the detectivity was 4.1x1012cm/Hz1/2W. The sensor array was hybridized with the commercially available readout integrated circuit using indium bumps. The noise equivalent differential temperature measured with F/2.3 optics was 31mK at 77K. The operability was over 99%. This FPA is suitable for full usage of the atmospheric window in the mid-wavelength region.

  16. Effects of membrane molecular weight cutoff on performance of a novel bioartificial liver.

    PubMed

    Shi, Xiao-lei; Zhang, Yue; Han, Bing; Gu, Jin-yang; Chu, Xue-hui; Xiao, Jiang-qiang; Ren, Hao-zhen; Tan, Jiao-jun; Ding, Yi-tao

    2011-03-01

    Immunoisolation using semipermeable membranes has been incorporated into bioartificial liver (BAL) devices to separate cellular components of the recipient's immune system from the cells within the BAL device. This study was designed to explore the influence of membrane molecular weight cutoff on performance of the multilayer radial-flow BAL using porcine hepatocytes cocultured with mesenchymal stem cells. In this study, healthy beagles underwent 6-h treatment with a BAL containing membrane with 200 kDa retention rating or 1200 kDa retention rating. Functional markers of BAL performance were monitored before and after treatment, as well as cytotoxic immune response to BAL therapy. The results showed that hepatocyte performance levels such as albumin secretion, urea synthesis, and viability were all significantly higher in 200 kDa retention rating group compared with the 1200 kDa retention rating group after treatment (P <  0.05). Significant levels of canine proteins were detected in BAL medium from the 1200 kDa retention rating group. Fluorescence microscopy further verified that heavy deposition of canine IgG, IgM, and complement (C3) on coculture cells was obtained after BAL treatment in the 1200 kDa retention rating group. However, only trace deposits of canine immunoproteins were observed on coculture cells obtained from BAL in the 200 kDa retention rating group. Small membrane molecular weight cutoff of the BAL could reduce the transfer of xenoreactive antibodies into the BAL medium and improve the performance of the BAL.

  17. The Epidemiologic and Pharmacodynamic Cutoff Values of Tilmicosin against Haemophilus parasuis

    PubMed Central

    Zhang, Peng; Hao, Haihong; Li, Jun; Ahmad, Ijaz; Cheng, Guyue; Chen, Dongmei; Tao, Yanfei; Huang, Lingli; Wang, Yulian; Dai, Menghong; Liu, Zhenli; Yuan, Zonghui

    2016-01-01

    The aim of this study was to establish antimicrobial susceptibility breakpoints for tilmicosin against Haemophilus parasuis, which is an important pathogen of respiratory tract infections. The minimum inhibitory concentrations (MICs) of 103 H. parasuis isolates were determined by the agar dilution method. The wild type (WT) distribution and epidemiologic cutoff value (ECV) were evaluated by statistical analysis. The new bronchoaveolar lavage was used to establish intrapulmonary pharmacokinetic (PK) model in swine. The pharmacokinetic (PK) parameters of tilmicosin, both in pulmonary epithelial lining fluid (PELF) and in plasma, were determined using high performance liquid chromatography method and WinNonlin software. The pharmacodynamic cutoff (COPD) was calculated using Monte Carlo simulation. Our results showed that 100% of WT isolates were covered when the ECV was set at 16 μg/mL. The tilmicosin had concentration-dependent activity against H. parasuis. The PK data indicated that tilmicosin concentrations in PELF was rapidly increased to high levels at 4 h and kept stable until 48 h after drug administration, while the tilmicosin concentration in plasma reached maximum levels at 4 h and continued to decrease during 4–72 h. Using Monte Carlo simulation, COPD was defined as 1 μg/mL. Conclusively, the ECV and COPD of tilmicosin against H. parasuis were established for the first time based on the MIC distribution and PK-PD analysis in the target tissue, respectively. These values are of great importance for detection of tilmicosin-resistant H. parasuis and for effective treatment of clinical intrapulmonary infection caused by H. parasuis. PMID:27047487

  18. Development and Validation of a High-Volume, Low-Cutoff Inertial Impactor.

    PubMed

    Kavouras, I G; Ferguson, S T; Wolfson, J M; Koutrakis, P

    2000-01-01

    A low-cutoff, high-volume conventional impactor has been designed. This sampler uses a slit-shaped acceleration jet and operates at 1100 L/min. The impaction substrate is polyurethane foam (PUF). The impactor collection efficiency was characterized using polydisperse particles, and the 50% size cutoff point was 0.12 ¡m. Losses within the sampler were also characterized and were less than 10%. The use of polyurethane foam (PUF) as a substrate has the following advantages: (I) PUF has a very high particle collection efficiency over a large range of particle sizes, even under conditions of heavy particle loading, as compared to other impaction substrates, such as flat plates and less porous membranes, which typically are subject to significant bounce-off and reentrainment; (2) no oil or grease coating is required, so potential interferences of impurities within such coatings are avoided when chemical, biological, and toxicological tests are performed on the collected particles; (3) PUF itself is chemically inert, minimizing interference with any of these tests; (4) because of the high flow rate of 1100 L/min, a large amount of particles can be collected in a short period of time on a relatively small surface of substrate, facilitating recovery of the collected particles for the different tests; and (5) a large amount of particles can be collected on a relatively small collection surface and easily extracted with small amounts of water or organic solvents. This method will be suitable for the collection of large amounts for toxicological studies and analysis of organic aerosols, which is not possible with other high-volume samplers that utilize large filtration surfaces.

  19. Interpolating moving least-squares methods for fitting potential-energy surfaces: further improvement of efficiency via cutoff strategies.

    PubMed

    Kawano, Akio; Tokmakov, Igor V; Thompson, Donald L; Wagner, Albert F; Minkoff, Michael

    2006-02-07

    In standard applications of interpolating moving least squares (IMLS) for fitting a potential-energy surface (PES), all available ab initio points are used. Because remote ab initio points negligibly influence IMLS accuracy and increase IMLS time-to-solution, we present two methods to locally restrict the number of points included in a particular fit. The fixed radius cutoff (FRC) method includes ab initio points within a hypersphere of fixed radius. The density adaptive cutoff (DAC) method includes points within a hypersphere of variable radius depending on the point density. We test these methods by fitting a six-dimensional analytical PES for hydrogen peroxide. Both methods reduce the IMLS time-to-solution by about an order of magnitude relative to that when no cutoff method is used. The DAC method is more robust and efficient than the FRC method.

  20. Extension of High Harmonic Generation Cutoff via Coherent Control of Intense Few-Cycle Chirped Laser Pulses

    NASA Astrophysics Data System (ADS)

    Carrera, Juan J.; Chu, Shih-I.

    2007-06-01

    We present an ab initio quantum investigation of the high-order harmonic generation (HHG) cutoff extension using intense few-cycle chirped laser pulses. For few-cycle chirped driving laser pulse, it is shown that significant cutoff extension can be achieved through the optimization of the chirping rate parameters. The HHG power spectrum is calculated by solving accurately and efficiently the time-dependent Schr"odinger equation by means of the time-dependent generalized pseudospectral method. The time-frequency characteristics of the HHG power spectrum are analyzed in details by means of the wavelet transform of the time-dependent induced dipole acceleration. In addition, we perform classical trajectory simulation of the strong-field electron dynamics and electron return map. It is found that the quantum and classical results provide complementary and consistent information regarding the underlying mechanisms responsible for the substantial extension of the cutoff region.

  1. The limitations of using vertical cutoff rigidities determined from the IGRF magnetic field models for computing aircraft radiation dose.

    PubMed

    Smart, D F; Shea, M A

    2003-01-01

    Vertical cutoff rigidities derived from the International Geomagnetic Reference Fields (IGRF) are normally used to compute the radiation dose at a specific location and to organize the radiation dose measurements acquired at aircraft altitudes. This paper presents some of the usually ignored limits on the accuracy of the vertical cutoff rigidity models and describes some of the computational artifacts present in these models. It is noted that recent aircraft surveys of the radiation dose experienced along specific flight paths is sufficiently precise that the secular variation of the geomagnetic field is observable.

  2. Shear avalanches in metallic glasses under nanoindentation: Deformation units and rate dependent strain burst cut-off

    SciTech Connect

    Bian, X. L.; Wang, G.; Gao, Y. L.; Zhai, Q. J.; Chan, K. C.; Ren, J. L.

    2013-09-02

    Indented metallic glasses at the nanoscale deform via strain bursts. Conventional continuum descriptions are not appropriate for such highly stochastic, intermittent deformations. In this study, after a statistical analysis of strain bursts in five metallic glasses, the dependence of the cut-off of the strain burst size on deformation units and loading rate is established. For soft metallic glasses with smaller deformation units, cut-off of the strain burst size truncates the scale-free behavior at larger strain burst sizes. For hard metallic glasses, scale-free behavior occurs in a wide range of strain burst sizes.

  3. Definition of advanced age in HIV infection: looking for an age cut-off.

    PubMed

    Blanco, José R; Jarrín, Inmaculada; Vallejo, Manuel; Berenguer, Juan; Solera, Carmen; Rubio, Rafael; Pulido, Federico; Asensi, Victor; del Amo, Julia; Moreno, Santiago

    2012-09-01

    The age of 50 has been considered as a cut-off to discriminate older subjects within HIV-infected people according to the Centers for Disease Control and Prevention (CDC). However, the International AIDS Society (IAS) mentions 60 years of age and the Department of Health and Human Services (DHHS) makes no consideration. We aimed to establish an age cut-off that could differentiate response to highly active antiretroviral therapy (HAART) and, therefore, help to define advanced age in HIV-infected patients. CoRIS is an open, prospective, multicenter cohort of HIV adults naive to HAART at entry (January 2004 to October 2009). Survival, immunological response (IR) (CD4 increase of more than 100 cell/ml), and virological response (VR) (HIV RNA less than 50 copies/ml) were compared among 5-year age intervals at start of HAART using Cox proportional hazards models, stratified by hospital and adjusted for potential confounders. Among 5514 patients, 2726 began HAART. During follow-up, 2164 (79.4%) patients experienced an IR, 1686 (61.8%) a VR, and 54 (1.9%) died. Compared with patients aged <25 years at start of HAART, those aged 50-54, 55-59, 60-64, 65-59, and 70 or older were 32% (aHR: 0.68, 95% CI: 0.52-0.87), 29% (aHR: 0.71, 95% CI: 0.53-0.96), 34% (aHR: 0.66, 95% CI: 0.46-0.95), 39% (aHR: 0.61, 95% CI: 0.37-1.00), and 43% (aHR: 0.57, 95% CI: 0.31-1.04) less likely to experience an IR. The VR was similar across all age groups. Finally, patients aged 50-59 showed a 3-fold increase (aHR: 3.58; 95% CI: 1.07-11.99) in their risk of death compared to those aged <30 years. In HIV infection, patients aged ≥50 years have a poorer immunological response to HAART and a poorer survival. This age could be used to define medically advanced age in HIV-infected people.

  4. Definition of Advanced Age in HIV Infection: Looking for an Age Cut-Off

    PubMed Central

    Jarrín, Inmaculada; Vallejo, Manuel; Berenguer, Juan; Solera, Carmen; Rubio, Rafael; Pulido, Federico; Asensi, Victor; del Amo, Julia; Moreno, Santiago

    2012-01-01

    Abstract The age of 50 has been considered as a cut-off to discriminate older subjects within HIV-infected people according to the Centers for Disease Control and Prevention (CDC). However, the International AIDS Society (IAS) mentions 60 years of age and the Department of Health and Human Services (DHHS) makes no consideration. We aimed to establish an age cut-off that could differentiate response to highly active antiretroviral therapy (HAART) and, therefore, help to define advanced age in HIV-infected patients. CoRIS is an open, prospective, multicenter cohort of HIV adults naive to HAART at entry (January 2004 to October 2009). Survival, immunological response (IR) (CD4 increase of more than 100 cell/ml), and virological response (VR) (HIV RNA less than 50 copies/ml) were compared among 5-year age intervals at start of HAART using Cox proportional hazards models, stratified by hospital and adjusted for potential confounders. Among 5514 patients, 2726 began HAART. During follow-up, 2164 (79.4%) patients experienced an IR, 1686 (61.8%) a VR, and 54 (1.9%) died. Compared with patients aged <25 years at start of HAART, those aged 50–54, 55–59, 60–64, 65–59, and 70 or older were 32% (aHR: 0.68, 95% CI: 0.52–0.87), 29% (aHR: 0.71, 95% CI: 0.53–0.96), 34% (aHR: 0.66, 95% CI: 0.46–0.95), 39% (aHR: 0.61, 95% CI: 0.37–1.00), and 43% (aHR: 0.57, 95% CI: 0.31–1.04) less likely to experience an IR. The VR was similar across all age groups. Finally, patients aged 50–59 showed a 3-fold increase (aHR: 3.58; 95% CI: 1.07–11.99) in their risk of death compared to those aged <30 years. In HIV infection, patients aged ≥50 years have a poorer immunological response to HAART and a poorer survival. This age could be used to define medically advanced age in HIV-infected people. PMID:22607516

  5. The female sexual function index (FSFI): cross-validation and development of clinical cutoff scores.

    PubMed

    Wiegel, Markus; Meston, Cindy; Rosen, Raymond

    2005-01-01

    The Female Sexual Function Index (FSFI) is a brief multidimensional scale for assessing sexual function in women. The scale has received initial psychometric evaluation, including studies of reliability, convergent validity, and discriminant validity (Meston, 2003; Rosen et al., 2000). The present study was designed to crossvalidate the FSFI in several samples of women with mixed sexual dysfunctions (N = 568) and to develop diagnostic cut-off scores for potential classification of women's sexual dysfunction. Some of these samples were drawn from our previous validation studies (N = 414), and some were added for purposes of the present study (N = 154). The combined data set consisted of multiple samples of women with sexual dysfunction diagnoses (N = 307), including female sexual arousal disorder (FSAD), hypoactive sexual desire disorder (HSDD), female sexual orgasm disorder (FSOD), dyspareunia/vaginismus (pain), and multiple sexual dysfunctions, in addition to a large sample of nondysfunctional controls (n = 261). We conducted analyses on the individual and combined samples, including replicating the original factor structure using principal components analysis with varimax rotation. We assessed Cronbach's alpha (internal reliability) and interdomain correlations and tested discriminant validity by means of a MANOVA (multivariate analysis of variance; dysfunction diagnosis x FSFI domain), with Bonferroni-corrected post hoc comparisons. We developed diagnostic cut off scores by means of standard receiver operating characteristics-curves and the CART (Classification and Regression Trees) procedure. Principal components analysis replicated the original five-factor structure, including desire/arousal, lubrication, orgasm, pain, and satisfaction. We found the internal reliability for the total FSFI and six domain scores to be good to excellent, with Cronbach alpha's >0.9 for the combined sample and above 0.8 for the sexually dysfunctional and nondysfunctional samples

  6. Establishing pathological cut-offs of brain atrophy rates in multiple sclerosis

    PubMed Central

    De Stefano, Nicola; Stromillo, Maria Laura; Giorgio, Antonio; Bartolozzi, Maria Letizia; Battaglini, Marco; Baldini, Mariella; Amato, Maria Pia; Sormani, Maria Pia

    2016-01-01

    Objective To assess whether it is feasible to establish specific cut-off values able to discriminate ‘physiological’ or ‘pathological’ brain volume rates in patients with multiple sclerosis (MS). Methods The study was based on the analysis of longitudinal MRI data sets of patients with MS (n=206, 87% relapsing–remitting, 7% secondary progressive and 6% primary progressive) and healthy controls (HC; n=35). Brain atrophy rates were computed over a mean follow-up of 7.5 years (range 1–12) for patients with MS and 6.3 years (range 1–12.5) for HC with the SIENA software and expressed as annualised per cent brain volume change (PBVC/y). A weighted (on the follow-up length) receiver operating characteristic analysis and the area under the curve (AUC) were used for statistics. Results The weighted PBVC/y was −0.51±0.27% in patients with MS and −0.27±0.15% in HC (p<0.0001). There was a significant age-related difference in PBVC/y between HC older and younger than 35 years of age (p=0.02), but not in patients with MS (p=0.8). The cut-off of PBVC/y, as measured by SIENA that could maximise the accuracy in discriminating patients with MS from HC, was −0.37%, with 67% sensitivity and 80% specificity. According to the observed distribution, values of PBVC/y as measured by SIENA that could define a pathological range were above −0.52% with 95% specificity, above −0.46% with 90% specificity and above −0.40% with 80% specificity. Conclusions Our evidence-based criteria provide values able to discriminate the presence or absence of ‘pathological’ brain volume loss in MS with high specificity. Such results could be of great value in a clinical setting, particularly in assessing treatment efficacy in MS. PMID:25904813

  7. Further performance evaluation of 5.3 μm cut-off Hawaii-2RG detectors

    NASA Astrophysics Data System (ADS)

    Ives, Derek; Beckmann, Udo; Alvarez, Domingo; Finger, Gert; Geimer, Christoph; Heininger, Matthias; Mehrgan, Leander; Tulloch, Simon

    2016-07-01

    ESO has now delivered or tested in-house, four new 5.3 μm cut-off H2RG detectors, for various projects, such as MATISSE for the VLTI and the upgrade project for CRIRES, the cryogenic high-resolution infrared echelle spectrograph for the VLT. The specified instruments have required the implementation of some of the more unusual read out options for these detectors, which may have already been used by other groups, for example, the line-reset-read and line-read-reset modes rather than the standard global reset mode. The detectors are also offered with both output speed options, that is, the standard slow, low noise readout and the faster, higher noise readout, where > 10 frames/s are possible. In the process of building these detector systems and implementing these new options we have delved deeper into some of the lesser known features of these detectors and tried to characterize them more fully. It is important that these characteristics are well understood before delivery of the next generation of detectors for the ELTs where high speed and windowing options are required. We obtain very good performance at 2 Mpixel/s pixel speeds with less than 40 e- rms read noise, in all other aspects such as linearity, noise versus number of non-destructive reads and cross talk then the performance of the outputs is the same as slow speed operation. However, the high speed output stages are quite complex to operate, they need to be very well tuned and are prone to oscillation, if not set correctly. We will report on the best bias options to optimize their performance. Some stability issues are also seen with the slow outputs and this is also reported. Likewise we have observed differences between global reset and line reset for the detectors, manifested in a significant increase in detector full well for the line reset option, this also will be reported on. We have also determined that there may be signal induced by the detector readout clocking process for certain detector

  8. Measuring extended red sensitivity in a 1.7μm-cutoff HgCdTe detector array

    NASA Astrophysics Data System (ADS)

    Terrien, Ryan C.; Monson, Andrew J.; Mahadevan, Suvrath; Bender, Chad; Halverson, Samuel P.; Ramsey, Larry

    2016-08-01

    Infrared detectors with cutoff wavelengths of 1.7 μm have much lower sensitivity to thermal background contamination than those with longer cutoff wavelengths. This low sensitivity offers the attractive possibility of reducing the need for fully cryogenic systems for YJH-band work, offering the potential for "warm-pupil" instrumentation that nonetheless reduces detected thermal background to the level of dark current. However, residual sensitivity beyond the cutoff wavelength is not well characterized, and may preclude the implementation of such warm-pupil instruments. We describe an experiment to evaluate the long-wavelength sensitivity tail of a 1.7 µm-cutoff HAWAII-2RG array using a thermal blocking filter. Our results suggest the possibility of measurable red sensitivity beyond 2 μm. Ongoing improvements will confirm and refine this measurement. The thermal blocking filter offers the prospect of warm-pupil NIR instrument operation, which is particularly valuable for cost-effective and efficient testing systems: it has facilitated NIR detector characterization and will enable crucial laboratory tests of laser frequency comb calibration systems and other NIR calibration sources.

  9. Intense, Narrow-band THz Emission from a Current Source Immersed in Cut-off of Plasma-like Media

    NASA Astrophysics Data System (ADS)

    Hur, Min Sup; Ersfeld, Bernhard; Noble, Adam; Suk, Hyyong; Jaroszynski, Dino

    2016-10-01

    Recently we found an interesting behavior of the electromagnetic radiation emerging from cut-off condition of a plasma-like medium, when it is driven by a current source. Differently from conventional total reflection of the incident wave at the cut-off, we found a spatially diffusing and temporally growing electromagnetic field from the current source. Direct result of such diffusion-growth is the selectively enhanced emission (SEE) at the cut-off frequency from a generally broadband current oscillation. We demonstrate examples demonstrating the SEE. One is the two-color-driven THz emission from field ionization of the gas slab located in a tapered waveguide. The emission propagating through the waveguide exhibits a significantly enhanced spectral density at the cut-off frequency. The other example is the THz emission from a magnetized plasma driven by two colliding ultra-short laser pulses. Since a very narrow-band emission can be selectively enhanced from a broadband radiation source, the SEE concept can be used for conversion of a general broadband THz source to a narrow-band one by locating it in a meta-structure such as the waveguide or a plasma-like medium. We discuss other possible systems to which SEE can be applied.

  10. On determining the most appropriate test cut-off value: the case of tests with continuous results

    PubMed Central

    Habibzadeh, Parham; Yadollahie, Mahboobeh

    2016-01-01

    There are several criteria for determination of the most appropriate cut-off value in a diagnostic test with continuous results. Mostly based on receiver operating characteristic (ROC) analysis, there are various methods to determine the test cut-off value. The most common criteria are the point on ROC curve where the sensitivity and specificity of the test are equal; the point on the curve with minimum distance from the left-upper corner of the unit square; and the point where the Youden’s index is maximum. There are also methods mainly based on Bayesian decision analysis. Herein, we show that a proposed method that maximizes the weighted number needed to misdiagnose, an index of diagnostic test effectiveness we previously proposed, is the most appropriate technique compared to the aforementioned ones. For determination of the cut-off value, we need to know the pretest probability of the disease of interest as well as the costs incurred by misdiagnosis. This means that even for a certain diagnostic test, the cut-off value is not universal and should be determined for each region and for each disease condition. PMID:27812299

  11. Conversion of Proportion-Correct Standard-Setting Judgments to Cutoff Scores on the Item Response Theory Theta Scale

    ERIC Educational Resources Information Center

    Hurtz, Gregory M.; Jones, J. Patrick; Jones, Christian N.

    2008-01-01

    This study compares the efficacy of different strategies for translating item-level, proportion-correct standard-setting judgments into a theta-metric test cutoff score for use with item response theory (IRT) scoring, using Monte Carlo methods. Simulated Angoff-type ratings, consisting of 1,000 independent 75 Item x13 Rater matrices, were…

  12. 26 CFR 1.585-7 - Elective cut-off method of changing from the reserve method of section 585.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... loans. (d) Effect of disposing of loans—(1) In general. Except as provided in paragraphs (d)(2) and (d... into the shoes of the transferor in the section 381(a) transaction with respect to using the cut-off...) received in the transaction, the acquiror does not step into the shoes of the transferor with respect...

  13. 26 CFR 1.585-7 - Elective cut-off method of changing from the reserve method of section 585.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... loans. (d) Effect of disposing of loans—(1) In general. Except as provided in paragraphs (d)(2) and (d... into the shoes of the transferor in the section 381(a) transaction with respect to using the cut-off...) received in the transaction, the acquiror does not step into the shoes of the transferor with respect...

  14. 26 CFR 1.585-7 - Elective cut-off method of changing from the reserve method of section 585.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... loans. (d) Effect of disposing of loans—(1) In general. Except as provided in paragraphs (d)(2) and (d... into the shoes of the transferor in the section 381(a) transaction with respect to using the cut-off...) received in the transaction, the acquiror does not step into the shoes of the transferor with respect...

  15. 26 CFR 1.585-7 - Elective cut-off method of changing from the reserve method of section 585.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... loans. (d) Effect of disposing of loans—(1) In general. Except as provided in paragraphs (d)(2) and (d... into the shoes of the transferor in the section 381(a) transaction with respect to using the cut-off...) received in the transaction, the acquiror does not step into the shoes of the transferor with respect...

  16. 26 CFR 1.585-7 - Elective cut-off method of changing from the reserve method of section 585.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... loans. (d) Effect of disposing of loans—(1) In general. Except as provided in paragraphs (d)(2) and (d... into the shoes of the transferor in the section 381(a) transaction with respect to using the cut-off...) received in the transaction, the acquiror does not step into the shoes of the transferor with respect...

  17. Dynamic monitoring of menopause hormone therapy and defining the cut-off value of endometrial thickness during uterine bleeding

    PubMed Central

    Sheng, Qiu; Yang, Jun; Zhao, Qiaoling; Li, Fen

    2016-01-01

    Abstract The aim of this study was to evaluate the effects of low-dose tibolone therapy on ovarian area, uterine volume and endometrial thickness, and define the cut-off value of endometrial thickness for curettage during uterine bleeding. We followed 619 postmenopausal women, aged 40-60 years, for two years. There were 301 subjects in the low-dose tibolone treatment group and 318 subjects in the control group. The ovarian area, uterine volume and endometrial thickness in all participants were measured by transvaginal ultrasound prior to, one and two years post enrollment, respectively. Endometrial specimens were collected from all subjects with abnormal uterine bleeding during the follow-up period. We found that the uterine volume in the treatment group was greater than that in the control group, and the difference was significant (P<0.05), but there were no significant differences in ovarian area and endometrial thickness between the two groups (P>0.05). When the cut-off value for endometrial thickness was 7.35 mm, the sensitivity and specificity were 100% and 79.07%, respectively, and 85.71% and 93.02% when 7.55 mm was set as the cut-off during tibolone therapy. The results indicate that low-dose tibolone therapy may postpone uterine atrophy and the cut-off value of endometrial thickness may be appropriately adjusted for curettage. PMID:27533929

  18. A simple numerical method for the cutoff frequency of a single-mode fiber with an arbitrary index-profile

    NASA Astrophysics Data System (ADS)

    Sharma, A.; Ghatak, A. K.

    1981-06-01

    A simple numerical method for calculating the cutoff frequency of single-mode operation in optical fibers with an arbitrary index-profile is presented. The method does not involve any approximation other than the scalar approximation and is applicable even to numerical data from index-profile measurements. The calculations are simple and can be carried out even on a programmable calculator.

  19. Shortened questionnaires to assess anxiety and depression during in-hospital rehabilitation: clinical validation and cutoff scores

    PubMed Central

    Bertolotti, Giorgio; Moroni, Loretta; Burro, Roberto; Spanevello, Antonio; Pedretti, Roberto FE; Giorgetti, Giandomenico

    2016-01-01

    Background A postacute phase needs reliable routine screening instruments in order to identify the patients to be referred for a clinical interview with a psychologist. The aim of this study was to estimate the clinical cutoff scores of the anxiety and depression questionnaires and their clinical validity using a gold standard. Methods The study involved 177 patients with pulmonary, cardiac, or neurological disease undergoing in-hospital rehabilitation. Receiver operating characteristic curves were used to determine the best concordance between questionnaire’s scores and the gold standards. Results There was a significant difference (P<0.001) between clinically anxious and depressed patients and nonclinical subjects. The receiver operating characteristic curve for anxiety indicated that the best area under the curve for State Anxiety Inventory is obtained with a cutoff point of 21 for males and 25 for females; for depression scores, the highest area under the curve for Depression Questionnaire-Reduced Form is obtained with a cutoff point of six for males and eight for females. Conclusion Using appropriate cutoff values, the State Anxiety Inventory and Depression Questionnaire-Reduced Form allow psychologists to optimize early clinical intervention strategies selecting patients with significant needs. PMID:27789951

  20. Empirically Derived Combinations of Tools and Clinical Cutoffs: An Illustrative Case with a Sample of Culturally/Linguistically Diverse Children

    ERIC Educational Resources Information Center

    Oetting, Janna B.; Cleveland, Lesli H.; Cope, Robert F., III

    2008-01-01

    Purpose: Using a sample of culturally/linguistically diverse children, we present data to illustrate the value of empirically derived combinations of tools and cutoffs for determining eligibility in child language impairment. Method: Data were from 95 4- and 6-year-olds (40 African American, 55 White; 18 with language impairment, 77 without) who…

  1. Jet grouting for a groundwater cutoff wall in difficult glacial soil deposits

    SciTech Connect

    Flanagan, R.F.; Pepe, F. Jr.

    1997-12-31

    Jet grouting is being used as part of a groundwater cutoff wall system in a major New York City subway construction project to limit drawdowns in an adjacent PCB contamination plume. A circular test shaft of jet grout columns was conducted during the design phase to obtain wall installation parameters. The test program also included shaft wall mapping, and measurements of; inflows, piezometric levels, ground heave and temperature, and jet grout hydraulic conductivity. An axisymmetric finite element method groundwater model was established to back calculate the in-situ hydraulic conductivities of both the surrounding glacial soils and the jet grout walls by matching observed inflows and piezometric levels. The model also verified the use of packer permeability test as a tool in the field to evaluate the hydraulic conductivities of jet grout columns. Both the test program and analytic studies indicated that adjustments to the construction procedures would be required to obtain lower hydraulic conductivities of the jet grout walls for construction. A comparison is made with the conductivities estimated from the test program/analytic studies with those from the present construction.

  2. EFFECTS OF THE TEMPERATURE ANISOTROPY ON THE MASER INSTABILITY EXCITED BY LOWER ENERGY CUTOFF BEHAVIOR

    SciTech Connect

    Tang, J. F.; Wu, D. J.; Yan, Y. H. E-mail: djwu@pmo.ac.cn

    2011-02-01

    The electron-cyclotron maser (ECM) conventionally driven by velocity anisotropies of energetic electrons trapped in magnetic fields is one of the most important radio-emission mechanisms in astrophysics. Recently, Wu and Tang proposed that a proper lower energy cutoff behavior of power-law electrons can effectively excite the ECM emission. This paper considers effects of temperature anisotropy on this new ECM mechanism. The results show that the growth rates of the ECM emissions increase with {beta}{sub perpendicular0} and {beta}{sub ||0}, where {beta}{sub perpendicular0} and {beta}{sub ||0} are the perpendicular and parallel velocity spreads (in units of the light velocity c) of the energetic electron beam, respectively. Moreover, the growth rates of O1 and X2 modes both sensitively depend on the ratio of the electron-cyclotron frequency to the plasma frequency {Omega} and reach their extremum values at {Omega} {approx_equal} 1.5 for the O1 mode and at {Omega} {approx_equal} 1.0 for the X2 mode. Meanwhile, as the mean velocity of the electron beam {beta}{sub s} (in units of c) increases, the growth rate of the O1 mode remains approximately constant and that of the X2 mode decreases considerably.

  3. Susceptibility profile and epidemiological cut-off values of Cryptococcus neoformans species complex from Argentina.

    PubMed

    Córdoba, Susana; Isla, Maria G; Szusz, Wanda; Vivot, Walter; Altamirano, Rodrigo; Davel, Graciela

    2016-06-01

    Epidemiological cut-off values (ECVs) based on minimal inhibitory concentration (MIC) distribution have been recently proposed for some antifungal drug/Cryptococcus neoformans combinations. However, these ECVs vary according to the species studied, being serotypes and the geographical origin of strains, variables to be considered. The aims were to define the wild-type (WT) population of the C. neoformans species complex (C. neoformans) isolated from patients living in Argentina, and to propose ECVs for six antifungal drugs. A total of 707 unique C. neoformans isolates obtained from HIV patients suffering cryptococcal meningitis were studied. The MIC of amphotericin B, flucytosine, fluconazole, itraconazole, voriconazole and posaconazole was determined according to the EDef 7.2 (EUCAST) reference document. The MIC distribution, MIC50 , MIC90 and ECV for each of these drugs were calculated. The highest ECV, which included ≥95% of the WT population modelled, was observed for flucytosine and fluconazole (32 μg ml(-1) each). For amphotericin B, itraconazole, voriconazole and posaconazole, the ECVs were: 0.5, 0.5, 0.5 and 0.06 μg ml(-1) respectively. The ECVs determined in this study may aid in identifying the C. neoformans strains circulating in Argentina with decreased susceptibility to the antifungal drugs tested.

  4. Studies in support of an SNM cutoff agreement: The PUREX exercise

    SciTech Connect

    Stanbro, W.D.; Libby, R.; Segal, J.

    1995-07-01

    On September 23, 1993, President Clinton, in a speech before the United Nations General Assembly, called for an international agreement banning the production of plutonium and highly enriched uranium for nuclear explosive purposes. A major element of any verification regime for such an agreement would probably involve inspections of reprocessing plants in Nuclear Nonproliferation Treaty weapons states. Many of these are large facilities built in the 1950s with no thought that they would be subject to international inspection. To learn about some of the problems that might be involved in the inspection of such large, old facilities, the Department of Energy, Office of Arms Control and Nonproliferation, sponsored a mock inspection exercise at the PUREX plant on the Hanford Site. This exercise examined a series of alternatives for inspections of the PUREX as a model for this type of facility at other locations. A series of conclusions were developed that can be used to guide the development of verification regimes for a cutoff agreement at reprocessing facilities.

  5. Control system optimization studies. Volume 2: High frequency cutoff filter analysis

    NASA Technical Reports Server (NTRS)

    Fong, M. H.

    1972-01-01

    The problem of digital implementation of a cutoff filter is approached with consideration to word length, sampling rate, accuracy requirements, computing time and hardware restrictions. Computing time and hardware requirements for four possible programming forms for the linear portions of the filter are determined. Upper bounds for the steady state system output error due to quantization for digital control systems containing a digital network programmed both in the direct form and in the canonical form are derived. This is accomplished by defining a set of error equations in the z domain and then applying the final value theorem to the solution. Quantization error was found to depend upon the digital word length, sampling rate, and system time constants. The error bound developed may be used to estimate the digital word length and sampling rate required to achieve a given system specification. From the quantization error accumulation, computing time and hardware point of view, and the fact that complex poles and zeros must be realized, the canonical form of programming seems preferable.

  6. Boltzmann brains and the scale-factor cutoff measure of the multiverse

    NASA Astrophysics Data System (ADS)

    de Simone, Andrea; Guth, Alan H.; Linde, Andrei; Noorbala, Mahdiyar; Salem, Michael P.; Vilenkin, Alexander

    2010-09-01

    To make predictions for an eternally inflating “multiverse,” one must adopt a procedure for regulating its divergent spacetime volume. Recently, a new test of such spacetime measures has emerged: normal observers—who evolve in pocket universes cooling from hot big bang conditions—must not be vastly outnumbered by “Boltzmann brains”—freak observers that pop in and out of existence as a result of rare quantum fluctuations. If the Boltzmann brains prevail, then a randomly chosen observer would be overwhelmingly likely to be surrounded by an empty world, where all but vacuum energy has redshifted away, rather than the rich structure that we observe. Using the scale-factor cutoff measure, we calculate the ratio of Boltzmann brains to normal observers. We find the ratio to be finite, and give an expression for it in terms of Boltzmann brain nucleation rates and vacuum decay rates. We discuss the conditions that these rates must obey for the ratio to be acceptable, and we discuss estimates of the rates under a variety of assumptions.

  7. Accuracy of Cameriere's cut-off value for third molar in assessing 18 years of age.

    PubMed

    De Luca, S; Biagi, R; Begnoni, G; Farronato, G; Cingolani, M; Merelli, V; Ferrante, L; Cameriere, R

    2014-02-01

    Due to increasingly numerous international migrations, estimating the age of unaccompanied minors is becoming of enormous significance for forensic professionals who are required to deliver expert opinions. The third molar tooth is one of the few anatomical sites available for estimating the age of individuals in late adolescence. This study verifies the accuracy of Cameriere's cut-off value of the third molar index (I3M) in assessing 18 years of age. For this purpose, a sample of orthopantomographs (OPTs) of 397 living subjects aged between 13 and 22 years (192 female and 205 male) was analyzed. Age distribution gradually decreases as I3M increases in both males and females. The results show that the sensitivity of the test was 86.6%, with a 95% confidence interval of (80.8%, 91.1%), and its specificity was 95.7%, with a 95% confidence interval of (92.1%, 98%). The proportion of correctly classified individuals was 91.4%. Estimated post-test probability, p was 95.6%, with a 95% confidence interval of (92%, 98%). Hence, the probability that a subject positive on the test (i.e., I3M<0.08) was 18 years of age or older was 95.6%.

  8. Lessons Learned from the Space Shuttle Engine Cutoff System (ECO) Anomalies

    NASA Technical Reports Server (NTRS)

    Martinez, Hugo E.; Welzyn, Ken

    2011-01-01

    The Space Shuttle Orbiter's main engine cutoff (ECO) system first failed ground checkout in April, 2005 during a first tanking test prior to Return-to-Flight. Despite significant troubleshooting and investigative efforts that followed, the root cause could not be found and intermittent anomalies continued to plague the Program. By implementing hardware upgrades, enhancing monitoring capability, and relaxing the launch rules, the Shuttle fleet was allowed to continue flying in spite of these unexplained failures. Root cause was finally determined following the launch attempts of STS-122 in December, 2007 when the anomalies repeated, which allowed drag-on instrumentation to pinpoint the fault (the ET feedthrough connector). The suspect hardware was removed and provided additional evidence towards root cause determination. Corrective action was implemented and the system has performed successfully since then. This white paper presents the lessons learned from the entire experience, beginning with the anomalies since Return-to-Flight through discovery and correction of the problem. To put these lessons in better perspective for the reader, an overview of the ECO system is presented first. Next, a chronological account of the failures and associated investigation activities is discussed. Root cause and corrective action are summarized, followed by the lessons learned.

  9. Azole susceptibility of Malassezia pachydermatis and Malassezia furfur and tentative epidemiological cut-off values.

    PubMed

    Cafarchia, Claudia; Iatta, Roberta; Immediato, Davide; Puttilli, Maria Rita; Otranto, Domenico

    2015-09-01

    This study aims to determine the minimal inhibitory concentration (MIC) distribution and the epidemiological cut-off values (ECVs) of Malassezia pachydermatis and Malassezia furfur isolates for fluconazole (FLZ), itraconazole (ITZ), posaconazole (POS), and voriconazole (VOR). A total of 62 M. pachydermatis strains from dogs with dermatitis and 78 M. furfur strains from humans with bloodstream infections (BSI) were tested by a modified broth microdilution Clinical and Laboratory Standards Institute (CLSI) method. ITZ and POS displayed lower MICs than VOR and FLZ, regardless of the Malassezia species. The MIC data for azoles of M. pachydermatis were four two-fold dilutions lower than those of M. furfur. Based on the ECVs, about 94% of Malassezia strains might be categorized within susceptible population for all azoles, except for FLZ, and azole cross-resistance was detected in association with FLZ in M. pachydermatis but not in M. furfur.The study proposes, for the first time, tentative azole ECVs for M. pachydermatis and M. furfur for monitoring the emergence of isolates with decreased susceptibilities and shows that the azole MIC distribution varied according to the Malassezia species tested, thus suggesting the usefulness of determining the susceptibility profile for effective treatment of each species.

  10. Calibration of Thomson scattering systems using electron cyclotron emission cutoff data

    SciTech Connect

    Zhurovich, K.; Mossessian, D.A.; Hughes, J.W.; Hubbard, A.E.; Irby, J.H.; Marmar, E.S.

    2005-05-15

    An alternative method of absolute calibration of Thomson scattering (TS) systems is described. The method is based on the measurements of electron cyclotron emission (ECE) from the plasma. If the plasma density reaches some critical value the emission at some frequencies is cut off and an abrupt loss of signal is registered by the ECE diagnostic. These critical values are calculated from the frequencies of the ECE channels in which cutoffs are observed, using the dispersion relation for the wave propagation. The radial positions of the ECE channels are bound to the measured magnetic field in the tokamak and, therefore, are known. The derived critical density values at certain positions in plasma are used to calculate absolute calibration coefficients for the core TS system. For that data points from the TS diagnostic are interpolated in time and space to these critical density values. This calibration technique is implemented in situ on the Alcator C-Mod tokamak during plasma operation. We use a nine-channel ECE diagnostic to calibrate the eight-channel core TS system. The uncertainty of the TS density calibration is {<=}10%, which is less than that from the gas scattering calibrations. Good agreement exists between TS density profiles and measurements from the visible continuum diagnostic and interferometry. Given the wide availability of ECE diagnostics on most tokamaks and other fusion devices, this technique should be suitable on many other experiments.

  11. Two-Stage Adaptive Cutoff (TACO) Design for Building and Validating a Prognostic Biomarker Signature

    PubMed Central

    Polley, Mei-Yin C.; Polley, Eric C.; Huang, Erich P.; Freidlin, Boris; Simon, Richard

    2014-01-01

    Cancer biomarkers are frequently evaluated using archived specimens collected from previously conducted therapeutic trials. Routine collection and banking of high quality specimens is an expensive and time-consuming process. Therefore, care should be taken to preserve these precious resources. Here we propose a novel two-stage adaptive cutoff (TACO) design that affords the possibility to stop the biomarker study early if an evaluation of the model performance is unsatisfactory at an early stage, thereby allowing one to preserve the remaining specimens for future research. In addition, our design integrates important elements necessary to meet statistical rigor and practical demands for developing and validating a prognostic biomarker signature, including maintaining strict separation between the datasets used to build and evaluate the model and producing a locked-down signature to facilitate future validation. We conduct simulation studies to evaluate the operating characteristics of the proposed design. We show that under the null hypothesis when the model performance is deemed undesirable, the proposed design maintains type I error at the nominal level, has high probabilities of terminating the study early, and results in substantial savings in specimens. Under the alternative hypothesis, power is generally high when the total sample size and the targeted degree of improvement in prediction accuracy are reasonably large. We illustrate the use of the procedure with a dataset in patients with diffuse large-B-cell lymphoma. The practical aspects of the proposed designs are discussed. PMID:25263614

  12. Routine inspection effort required for verification of a nuclear material production cutoff convention

    SciTech Connect

    Dougherty, D.; Fainberg, A.; Sanborn, J.; Allentuck, J.; Sun, C.

    1996-11-01

    On 27 September 1993, President Clinton proposed {open_quotes}... a multilateral convention prohibiting the production of highly enriched uranium or plutonium for nuclear explosives purposes or outside of international safeguards.{close_quotes} The UN General Assembly subsequently adopted a resolution recommending negotiation of a non-discriminatory, multilateral, and internationally and effectively verifiable treaty (hereinafter referred to as {open_quotes}the Cutoff Convention{close_quotes}) banning the production of fissile material for nuclear weapons. The matter is now on the agenda of the Conference on Disarmament, although not yet under negotiation. This accord would, in effect, place all fissile material (defined as highly enriched uranium and plutonium) produced after entry into force (EIF) of the accord under international safeguards. {open_quotes}Production{close_quotes} would mean separation of the material in question from radioactive fission products, as in spent fuel reprocessing, or enrichment of uranium above the 20% level, which defines highly enriched uranium (HEU). Facilities where such production could occur would be safeguarded to verify that either such production is not occurring or that all material produced at these facilities is maintained under safeguards.

  13. The cutoff values of indirect indices for measuring insulin resistance for metabolic syndrome in Korean children and adolescents

    PubMed Central

    Kim, Jun Woo; Park, Sang Hoo; Kim, Yoojin; Im, Minji

    2016-01-01

    Purpose The prevalence rates of metabolic syndrome (MetS) and percentile distribution of insulin resistance (IR) among Korean children and adolescents were investigated. The cutoff values of IR were calculated to identify high-risk MetS groups. Methods Data from 3,313 Korean subjects (1,756 boys and 1,557 girls, aged 10–18 years) were included from the Korean National Health and Nutrition Examination Survey conducted during 2007–2010. Three different sets of criteria for MetS were used. Indirect measures of IR were homeostasis model assessment (HOMA-IR) and triglyceride and glucose (TyG) index. The cutoff values of the HOMA-IR and TyG index were obtained from the receiver operation characteristic curves. Results According to the MetS criteria of de Ferranti el al., Cook et al., and the International Diabetes Federation, the prevalence rates in males and females were 13.9% and 12.3%, 4.6% and 3.6%, and 1.4% and 1.8%, respectively. Uses these 3 criteria, the cutoff values of the HOMA-IR and TyG index were 2.94 and 8.41, 3.29 and 8.38, and 3.54 and 8.66, respectively. The cutoff values using each of the 3 criteria approximately corresponds to the 50th–75th, 75th, and 75th–90th percentiles of normal HOMA-IR and TyG index levels. Conclusion This study describes the prevalence rates of MetS in Korean children and adolescents, an index of IR, and the cutoff values for MetS with the aim of detecting high-risk groups. The usefulness of these criteria needs to be verified by further evaluation. PMID:27777906

  14. Extended characterization of a new class of membranes for blood purification: the high cut-off membranes.

    PubMed

    Boschetti-de-Fierro, Adriana; Voigt, Manuel; Storr, Markus; Krause, Bernd

    2013-07-01

    High cut-off membranes are a new class of blood purification membranes whose particular characteristics present challenges for commonly-used characterization methods. Dextran sieving curves for representative blood purification membranes of the high-flux and high cut-off types were measured and compared to curves for the glomerular filtration barrier (GFB). The performance was also determined after blood exposure for the most permeable synthetic membranes. High cut-off membranes were observed to be more open than the GFB before blood exposure, but become tighter and more selective after the exposure, keeping the permeation for low and middle molecules while restraining the filtration of large species. Based on dextran sieving experiments for a variety of commercially available blood purification membranes, we present a novel method for classifying blood purification membranes. By using a well-established technique and introducing a new characteristic parameter for the sieving curve--the molecular weight retention onset (MWRO)--a graph of molecular weight cut-off versus molecular weight retention onset provides the landscape of dialysis membrane types. This meaningful representation is based on only one in vitro method, and allows the membrane classification by indirectly considering two structural parameters: pore size and pore size distribution. In this way, the families of low-flux, high-flux, protein leaking, and high cut-off membranes are clearly differentiated. The differentiation allows for the definition of MWCO/MWRO regions for the different types, so that further classification of newly developed membranes can be easily achieved.

  15. Testing the role of meander cutoff in promoting gene flow across a riverine barrier in ground skinks (Scincella lateralis).

    PubMed

    Jackson, Nathan D; Austin, Christopher C

    2013-01-01

    Despite considerable attention, the long-term impact of rivers on species diversification remains uncertain. Meander loop cutoff (MLC) is one river phenomenon that may compromise a river's diversifying effects by passively transferring organisms from one side of the river to the other. However, the ability of MLC to promote gene flow across rivers has not been demonstrated empirically. Here, we test several predictions of MLC-mediated gene flow in populations of North American ground skinks (Scincella lateralis) separated by a well-established riverine barrier, the Mississippi River: 1) individuals collected from within meander cutoffs should be more closely related to individuals across the river than on the same side, 2) individuals within meander cutoffs should contain more immigrants than individuals away from meander cutoffs, 3) immigration rates estimated across the river should be highest in the direction of the cutoff event, and 4) the distribution of alleles native to one side of the river should be better predicted by the historical rather than current path of the river. To test these predictions we sampled 13 microsatellite loci and mitochondrial DNA from ground skinks collected near three ancient meander loops. These predictions were generally supported by genetic data, although support was stronger for mtDNA than for microsatellite data. Partial support for genetic divergence of samples within ancient meander loops also provides evidence for the MLC hypothesis. Although a role for MLC-mediated gene flow was supported here for ground skinks, the transient nature of river channels and morphologies may limit the long-term importance of MLC in stemming population divergence across major rivers.

  16. Testing the Role of Meander Cutoff in Promoting Gene Flow across a Riverine Barrier in Ground Skinks (Scincella lateralis)

    PubMed Central

    Jackson, Nathan D.; Austin, Christopher C.

    2013-01-01

    Despite considerable attention, the long-term impact of rivers on species diversification remains uncertain. Meander loop cutoff (MLC) is one river phenomenon that may compromise a river’s diversifying effects by passively transferring organisms from one side of the river to the other. However, the ability of MLC to promote gene flow across rivers has not been demonstrated empirically. Here, we test several predictions of MLC-mediated gene flow in populations of North American ground skinks (Scincella lateralis) separated by a well-established riverine barrier, the Mississippi River: 1) individuals collected from within meander cutoffs should be more closely related to individuals across the river than on the same side, 2) individuals within meander cutoffs should contain more immigrants than individuals away from meander cutoffs, 3) immigration rates estimated across the river should be highest in the direction of the cutoff event, and 4) the distribution of alleles native to one side of the river should be better predicted by the historical rather than current path of the river. To test these predictions we sampled 13 microsatellite loci and mitochondrial DNA from ground skinks collected near three ancient meander loops. These predictions were generally supported by genetic data, although support was stronger for mtDNA than for microsatellite data. Partial support for genetic divergence of samples within ancient meander loops also provides evidence for the MLC hypothesis. Although a role for MLC-mediated gene flow was supported here for ground skinks, the transient nature of river channels and morphologies may limit the long-term importance of MLC in stemming population divergence across major rivers. PMID:23658778

  17. Estimate of a predictive cut-off value for serum 25-hydroxyvitamin D reflecting abdominal obesity in Korean adolescents.

    PubMed

    Nam, Ga Eun; Kim, Do Hoon; Cho, Kyung Hwan; Park, Yong Gyu; Han, Kyung Do; Choi, Youn Seon; Kim, Seon Mee; Ko, Byung Joon; Kim, Yang Hyun; Lee, Kyung Shik

    2012-06-01

    Vitamin D deficiency is a serious global issue. Although the serum 25-hydroxyvitamin D [25(OH)D] test is generally the most accurate way to assess vitamin D levels, the optimal range of 25(OH)D has yet to be established. Moreover, the optimal level may vary according to race, region, and age. Suboptimal vitamin D status is associated with obesity and metabolic syndrome, which are the major risk factors for cardiovascular disorders; however, these relationships in children and adolescents have yet to be clearly determined. Therefore, we identified the best predictive cut-off value for reflecting abdominal obesity and, based on this value, we investigated the relationship between suboptimal 25(OH)D status and the risk for having abdominal obesity, being overweight or obese, and having metabolic syndrome in Korean adolescents. We performed a cross-sectional analysis of 713 Korean adolescents, between 12-19 years of age, and used data collected from the 2008 Korea National Health and Nutrition Examination Survey (KNHANES). Receiver operation characteristic curve analysis was used to identify the cut-off value that reflected abdominal obesity. The cut-off value of serum 25(OH)D that reflected abdominal obesity in Korean adolescents was 17.6 ng/mL. After making adjustments for gender, age, and regular physical exercise, the group that had lower levels of serum 25(OH)D compared to the cut-off value had a significantly higher risk for abdominal obesity, obesity, and metabolic syndrome than the group with 25(OH)D levels higher than the cut-off value. Suboptimal vitamin D status based on this value is associated with increased risk for abdominal obesity, obesity, and metabolic syndrome among Korean adolescents.

  18. A fully covariant information-theoretic ultraviolet cutoff for scalar fields in expanding Friedmann Robertson Walker spacetimes

    NASA Astrophysics Data System (ADS)

    Kempf, A.; Chatwin-Davies, A.; Martin, R. T. W.

    2013-02-01

    While a natural ultraviolet cutoff, presumably at the Planck length, is widely assumed to exist in nature, it is nontrivial to implement a minimum length scale covariantly. This is because the presence of a fixed minimum length needs to be reconciled with the ability of Lorentz transformations to contract lengths. In this paper, we implement a fully covariant Planck scale cutoff by cutting off the spectrum of the d'Alembertian. In this scenario, consistent with Lorentz contractions, wavelengths that are arbitrarily smaller than the Planck length continue to exist. However, the dynamics of modes of wavelengths that are significantly smaller than the Planck length possess a very small bandwidth. This has the effect of freezing the dynamics of such modes. While both wavelengths and bandwidths are frame dependent, Lorentz contraction and time dilation conspire to make the freezing of modes of trans-Planckian wavelengths covariant. In particular, we show that this ultraviolet cutoff can be implemented covariantly also in curved spacetimes. We focus on Friedmann Robertson Walker spacetimes and their much-discussed trans-Planckian question: The physical wavelength of each comoving mode was smaller than the Planck scale at sufficiently early times. What was the mode's dynamics then? Here, we show that in the presence of the covariant UV cutoff, the dynamical bandwidth of a comoving mode is essentially zero up until its physical wavelength starts exceeding the Planck length. In particular, we show that under general assumptions, the number of dynamical degrees of freedom of each comoving mode all the way up to some arbitrary finite time is actually finite. Our results also open the way to calculating the impact of this natural UV cutoff on inflationary predictions for the cosmic microwave background.

  19. Lateral Cutoff Analysis and Results from NASA's Farfield Investigation of No-Boom Thresholds

    NASA Technical Reports Server (NTRS)

    Cliatt, Larry J., II; Haering, Edward A., Jr.; Arnac, Sarah R.; Hill, Michael A.

    2016-01-01

    In support of the ongoing effort by the National Aeronautics and Space Administration (NASA) to bring supersonic commercial travel to the public, the NASA Armstrong Flight Research Center (AFRC) and the NASA Langley Research Center (LaRC), in partnership with other industry organizations and academia, conducted a flight research experiment to analyze acoustic propagation at the lateral edge of the sonic boom carpet. The name of the effort was the Farfield Investigation of No-boom Thresholds (FaINT). The test helped to build a dataset that will go toward further understanding of the unique acoustic propagation characteristics near the sonic boom carpet extremity. The FaINT was an effort that collected finely-space sonic boom data across the entire lateral cutoff transition region. A major objective of the effort was to investigate the acoustic phenomena that occur at the audible edge of a sonic boom carpet, including the transition and shadow zones. A NASA F-18B aircraft made supersonic passes such that its sonic boom carpet transition zone would intersect a linear 60-microphone, 7500-ft long array. A TG-14 motor glider equipped with a microphone on its wing also attempted to capture the same sonic boom rays that were measured on the ground, at altitudes of 3000 - 6000 ft above ground level. This paper determined an appropriate metric for sonic boom waveforms in the transition and shadow zones called Perceived Sound Exposure Level, and established a value of 65 dB as a limit for the acoustic levels defining the lateral extent of a sonic boom's noise region; analyzed the change in sonic boom levels as a function of distance from flight path both on the ground and 4500 ft above the ground; and compared between sonic boom measurements and numerical predictions.

  20. Metacognitive impairments in schizophrenia are arrested at extreme levels of psychopathy: The cut-off effect.

    PubMed

    Abu-Akel, Ahmad; Heinke, Dietmar; Gillespie, Steven M; Mitchell, Ian J; Bo, Sune

    2015-11-01

    Psychopathy and metacognitive difficulties have been associated with the occurrence of violence in schizophrenia. However, evidence suggests that nonschizophrenic psychopaths match or even outperform healthy controls on tests of metacognition. We hypothesize that the metacognitive difficulties associated with schizophrenia may be ameliorated by comorbid psychopathy. To this end, metacognition (using the Metacognition Assessment Scale-Abbreviated [MAS-A]) and psychopathy (using the Hare Psychopathy Checklist-Revised [PCL-R]) are assessed in 79 patients with schizophrenia with a history of criminal offending. Piecewise regression reveals that the association between metacognition and psychopathy changes from a negative to a positive association at a breakpoint corresponding to a score of 24 on the PCL-R. This score is within the range of the cut-off point used for the diagnosis of psychopathy in Europe, which corresponds to a score of 26 on the PCL-R. The patients scoring above 24 on the PCL-R demonstrated better overall metacognitive abilities, suggesting that these patients constitute a specific group in which schizophrenia has an attenuated impairing effect on metacognition. However, this effect was absent for the Mastery subscale of the MAS-A, which refers to the ability to use one's own mental states to solve social and psychological dilemmas. Our results suggest that the relative preservation of metacognitive abilities in schizophrenic patients with extreme levels of psychopathy may contribute to their offending behavior as it may enable them to understand how to manipulate and extort their victims. However, enhancing the Mastery domain of metacognition in these patients may attenuate this offending behavior.

  1. Age, Gender and Ethnic Differences in Prevalence of Overweight and Obesity in Asian American College Students and Their Parents Using Different BMI Cutoffs

    ERIC Educational Resources Information Center

    Wang, Li Hui; Chen, Ying Chang; Ka Chung, Angela; Poon, George; Lew, Polong; Tam, Chick F.

    2007-01-01

    The objective was to determine if the WHO global BMI (kg/m[squared]) cutoffs for determining overweight and obesity in the general populations are appropriate for Asian populations and to consider whether population-specific cutoffs would be warranted. A nonrandomized biased sampling of 227 Asian Americans were composed of 149 college students,…

  2. In Search of Golden Rules: Comment on Hypothesis-Testing Approaches to Setting Cutoff Values for Fit Indexes and Dangers in Overgeneralizing Hu and Bentler's (1999) Findings

    ERIC Educational Resources Information Center

    Marsh, Herbert W.; Hau, Kit-Tai; Wen, Zhonglin

    2004-01-01

    Goodness-of-fit (GOF) indexes provide "rules of thumb"?recommended cutoff values for assessing fit in structural equation modeling. Hu and Bentler (1999) proposed a more rigorous approach to evaluating decision rules based on GOF indexes and, on this basis, proposed new and more stringent cutoff values for many indexes. This article discusses…

  3. The Objective Borderline Method (OBM): A Probability-Based Model for Setting up an Objective Pass/Fail Cut-Off Score in Medical Programme Assessments

    ERIC Educational Resources Information Center

    Shulruf, Boaz; Turner, Rolf; Poole, Phillippa; Wilkinson, Tim

    2013-01-01

    The decision to pass or fail a medical student is a "high stakes" one. The aim of this study is to introduce and demonstrate the feasibility and practicality of a new objective standard-setting method for determining the pass/fail cut-off score from borderline grades. Three methods for setting up pass/fail cut-off scores were compared: the…

  4. Determining the optimal cutoff points for waist circumference and body mass index for identification of metabolic abnormalities and metabolic syndrome in urban Thai population.

    PubMed

    Worachartcheewan, Apilak; Dansethakul, Prabhop; Nantasenamat, Chanin; Pidetcha, Phannee; Prachayasittikul, Virapong

    2012-11-01

    This study describes the prevalence and optimal waist circumference (WC) and body mass index (BMI) cutoff point for metabolic abnormalities and metabolic syndrome (MS) from urban Thai population. The optimal BMI/WC cutoff has been used for identifying and evaluating metabolic abnormalities for screening individuals having risk factor of MS.

  5. [Receiver operating characteristic analysis and the cost--benefit analysis in determination of the optimal cut-off point].

    PubMed

    Vránová, J; Horák, J; Krátká, K; Hendrichová, M; Kovaírková, K

    2009-01-01

    An overview of the use of Receiver Operating Characteristic (ROC) analysis within medicine is provided. A survey of the theory behind the analysis is offered together with a presentation on how to create a ROC curve and how to use Cost--Benefit analysis to determine the optimal cut-off point or threshold. The use of ROC analysis is exemplified in the "Cost--Benefit analysis" section of the paper. In these examples, it can be seen that the determination of the optimal cut-off point is mainly influenced by the prevalence and the severity of the disease, by the risks and adverse events of treatment or the diagnostic testing, by the overall costs of treating true and false positives (TP and FP), and by the risk of deficient or non-treatment of false negative (FN) cases.

  6. Waist-to-Height Ratio Percentiles and Cutoffs for Obesity: A Cross-sectional Study in Brazilian Adolescents

    PubMed Central

    Zanetti Passos, Maria Aparecida; dos Santos, Luana Caroline; da Costa Machado, Helymar; Fisberg, Mauro

    2014-01-01

    ABSTRACT This study aimed to describe the distribution of waist-to-height ratio (WHtR) percentiles and cutoffs for obesity in Brazilian adolescents. A cross-sectional study including adolescents aged 10 to 15 years was conducted in the city of São Paulo, Brazil; anthropometric measurements (weight, height, and waist-circumference) were taken, and WHtRs were calculated and then divided into percentiles derived by using Least Median of Squares (LMS) regression. The receiver operating characteristic (ROC) curve was used in determining cutoffs for obesity (BMI ≥97th percentile) and Mann-Whitney and Kruskal-Wallis tests were used for comparing variables. The study included 8,019 adolescents from 43 schools, of whom 54.5% were female, and 74.8% attended public schools. Boys had higher mean WHtR than girls (0.45±0.06 vs 0.44±0.05; p=0.002) and higher WHtR at the 95th percentile (0.56 vs 0.54; p<0.05). The WHtR cutoffs according to the WHO criteria ranged from 0.467 to 0.506 and 0.463 to 0.496 among girls and boys respectively, with high sensitivity (82.8-95%) and specificity (84-95.5%). The WHtR was significantly associated with body adiposity measured by BMI. Its age-specific percentiles and cutoffs may be used as additional surrogate markers of central obesity and its co-morbidities. PMID:25395904

  7. Gestational Age-specific Cut-off Values Are Needed for Diagnosis of Subclinical Hypothyroidism in Early Pregnancy.

    PubMed

    Kim, Hye Sung; Kim, Byoung Jae; Oh, Sohee; Lee, Da Young; Hwang, Kyu Ri; Jeon, Hye Won; Lee, Seung Mi

    2015-09-01

    During the first trimester of pregnancy, thyroid-stimulating hormone (TSH) >2.5 mIU/L has been suggested as the universal criterion for subclinical hypothyroidism. However, TSH levels change continuously during pregnancy, even in the first trimester. Therefore the use of a fixed cut-off value for TSH may result in a different diagnosis rate of subclinical hypothyroidism according to gestational age. The objective of this study was to obtain the normal reference range of TSH during the first trimester in Korean gravida and to determine the diagnosis rate of subclinical hypothyroidism using the fixed cut-off value (TSH >2.5 mIU/L). The study population consisted of pregnant women who were measured for TSH during the first trimester of pregnancy (n=492) and nonpregnant women (n=984). Median concentration of TSH in pregnant women was lower than in non-pregnant women. There was a continuous decrease of median TSH concentration during the first trimester of pregnancy (median TSH concentration: 1.82 mIU/L for 3+0 to 6+6 weeks; 1.53 mIU/L for 7+0 to 7+6 weeks; and 1.05 mIU/L for 8+0 to 13+6 weeks). Using the fixed cut-off value of TSH >2.5 mIU/L, the diagnosis rate of subclinical hypothyroidism decreased significantly according to the gestational age (GA) at TSH (25% in 3+0 to 6+6 weeks, 13% in 7+0 to 7+6 weeks, and 9% for 8+0 to 13+6 weeks, P<0.001), whereas the diagnosis rate was 5% in all GA with the use of a GA-specific cut-off value (P=0.995). Therefore, GA-specific criteria might be more appropriate for the diagnosis of subclinical hypothyroidism.

  8. The Prevalence of Nocturia and Nocturnal Polyuria: Can New Cutoff Values Be Suggested According to Age and Sex?

    PubMed Central

    2016-01-01

    Purpose The aims of this study were to assess the prevalence of nocturia and nocturnal polyuria (NP) and to define new cutoff values according to age and sex for both conditions. Methods Data from a population-based prevalence survey conducted among a random sample of 2,128 adults were analyzed in this study. Participants were requested to fill out a questionnaire including the International Continence Society (ICS) definitions of lower urinary tract symptoms and the International Consultation on Incontinence Questionnaire - Short Form. Additionally, a 1-day bladder diary was given to each individual. The participants were divided into 5 age groups. The prevalence of nocturia was calculated based on definitions of nocturia as ≥1 voiding episodes, ≥2 episodes, and ≥3 episodes. NP was evaluated according to the ICS definition. The mean±standard errors and 95th percentile values were calculated in each group as new cutoff values for NP. Results The prevalence of nocturia was estimated as 28.4%, 17.6%, and 8.9% for ≥1, ≥2, and ≥3 voiding episodes each night, respectively. When nocturia was defined as 2 or more voiding episodes at night, the prevalence decreased significantly. The mean NP index was 29.4%±15.0% in men and 23.1%±11.8% in women. For the age groups of <50 years, 50–59 years, and ≥60 years, the new cutoff values for the diagnosis of NP were calculated as 48%, 69%, and 59% for men and 41%, 50%, and 42% for women, respectively. Conclusions We found that the definition of nocturia was still controversial and that waking up once for voiding might be within the normal spectrum of behavior. The definition of NP should be modified, and new cutoff values should be defined using the data presented in our study and in other forthcoming studies. PMID:28043108

  9. Grading the intensity of nondental orofacial pain: identification of cutoff points for mild, moderate, and severe pain

    PubMed Central

    Brailo, Vlaho; Zakrzewska, Joanna M

    2015-01-01

    Background When assessing pain in clinical practice, clinicians often label pain as mild, moderate, and severe. However, these categories are not distinctly defined, and are often used arbitrarily. Instruments for pain assessment use more sophisticated scales, such as a 0–10 numerical rating scale, and apart from pain intensity assess pain-related interference and disability. The aim of the study was to identify cutoff points for mild, moderate, and severe nondental orofacial pain using a numerical rating scale, a pain-related interference scale, and a disability measurement. Materials and methods A total of 245 patients referred to the Facial Pain Unit in London were included in the study. Intensity and pain-related interference were assessed by the Brief Pain Inventory. Pain-related disability was assessed by the Chronic Graded Pain Scale. Average pain intensity (0–10) was classified into nine schemes with varying cutoff points of mild, moderate, and severe pain. The scheme with the most significant intergroup difference, expressed by multivariate analysis of variance, provided the cutoffs between mild, moderate, and severe pain. Results The combination that showed the greatest intergroup differences for all patients was scheme 47 (mild 1–4, moderate 5–7, severe 8–10). The same combination provided the greatest intergroup differences in subgroups of patients with temporomandibular disorder and chronic idiopathic facial pain, respectively. Among the trigeminal neuralgia patients alone, the combination with the highest intergroup differences was scheme 48 (mild 1–4, moderate 5–8, severe 9–10). Conclusion The cutoff points established in this study can discriminate in pain intensity categories reasonably well, and showed a significant difference in most of the outcome measures used. PMID:25759597

  10. Cut-Off Value for Pain Sensitivity Questionnaire in Predicting Surgical Success in Patients with Lumbar Disc Herniation

    PubMed Central

    Azimi, Parisa; Benzel, Edward C.

    2016-01-01

    Various factors related to predict surgical success were studied; however, a standard cut-off point for the Pain Sensitivity Questionnaire (PSQ) measure has not yet been established for a favorable surgical outcome for lumbar disc herniation (LDH). This study was to find the optimal cut-off point on the PSQ to distinguish surgical success in patients with LDH. A total of 154 patients with LDH consecutively referred to our clinic were enrolled into this prospective study between February 2011 and January 2014. All participants completed the PSQ. Patients completed the Oswestry Disability Index (ODI) score before surgery, and at 2 years after surgery. Surgical success was defined as a 13-point improvement from the baseline ODI scores. The cut-off value for PSQ was determined by the receiver-operating characteristic curve (ROC). The mean age of patients was 49.3±9.6 years, and there were 80 women. The mean time for follow-up assessment was 31±5 months (range 24–35). Post-surgical success was 79.9% (n = 123) at 2 years follow up. The mean score for the total PSQ, PSQ-minor, and PSQ-moderate were 6.0 (SD = 1.6), 5.4 (SD = 1.9) and 6.5 (SD = 1.7), respectively. Total PSQ score was also significantly correlated with the total scores of the ODI. The optimal total PSQ cut-off point was determined as > 5.2 to predict surgical success in LDH patients, with 80.0% sensitivity and 75.6% specificity (AUC-0.814, 95% CI 0.703–0.926). This study showed that the PSQ could be considered a parameter for predicting surgical success in patients with LDH, and can be useful in clinical practice. PMID:27494617

  11. Archaeological Investigations at 3SF332: An Early Mississippian and Tenant Period Site on Cutoff Bayou, St. Francis County, Arkansas

    DTIC Science & Technology

    1991-06-01

    include Fifteenmile Bayou, Blackfish Bayou, and Cutoff Bayou, on which 3SF332 is located. SOILS The project area is situated on one of 10 major soil...on Big Creek (Dwyer 1978; LeeDecker 1979a; Klinger 1981, 1985; Klinger and Imhoff 1982; Kinger et al. 1983; McNeil 1984), Blackfish Bayou (LeeDecker...Memphis. Submitted to U.S. Army Corps of Engineers, Memphis District, Memphis. Arkansas Archeological Survey AMASDA Project File No. 682. 1979b Blackfish

  12. Calcification of thyroid nodules increases shear-wave speed (SWS) measurement: using multiple calcification-specific SWS cutoff values outperforms a single uniform cutoff value in diagnosing malignant thyroid nodules

    PubMed Central

    Chen, Bao-Ding; Xu, Hui-Xiong; Zhang, Yi-Feng; Liu, Bo-Ji; Guo, Le-Hang; Li, Dan-Dan; Zhao, Chong-Ke; Li, Xiao-Long; Wang, Dan; Zhao, Shuang-Shuang

    2016-01-01

    Conventional ultrasound cannot satisfactorily distinguish malignant and benign thyroid nodules. Shear-wave elastography (SWE) can evaluate tissue stiffness and complement conventional ultrasound in diagnosing malignant nodules. However, calcification of nodules may affect the results of SWE. The purposes of this study are to compare the differences of shear-wave speed (SWS) measurement among different calcification groups and compare the diagnostic performance between using a single uniform SWS cutoff value and multiple individual calcification-specific cutoff values using technique of point SWS measurement. We retrospectively identified 517 thyroid nodules (346 benign and 171 malignant nodules) examined by conventional ultrasound and point SWS measurement. There were 177 non-calcified, 159 micro-calcified and 181 macro-calcified nodules. The diagnostic performance was evaluated by receiver operating characteristic (ROC) curve and area under the curve (AUC) was computed. The mean SWS in malignant nodules more than doubled that of benign nodules (4.81±2.03 m/s vs. 2.29±0.99 m/s, p<0.001). The mean SWS of nodules progressively increased from the non-calcification (2.60±1.49 m/s), to micro-calcification (3.27±1.85 m/s) and to macro-calcification (3.68±2.26 m/s) groups (p<0.001), which was true in both the benign and malignant nodules. If we used individual SWS cutoff values for non- (SWS >2.42 m/s), micro- (SWS >2.88 m/s) and macro-calcification (SWS >3.59 m/s) nodules in the whole group, the AUC was 0.859 (95% confidence interval [CI], 0.826-0.888), which was significantly better than the AUC of 0.816 (95% CI, 0.780-0.848) if a single uniform cutoff value (SWS >2.72 m/s) was applied to all the nodules regardless of calcification status (p=0.011). The cutoff values of SWS for different calcified nodules warrant future prospective validation. PMID:27588492

  13. DEVELOPMENT AND VALIDATION OF A HIGH-VOLUME, LOW-CUTOFF INERTIAL IMPACTOR. (R825270)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  14. Some Factors Affecting the Reproducibility of Penetration and the Cut-Off of Oil Sprays for Fuel-injection Engines

    NASA Technical Reports Server (NTRS)

    Beardsley, E G

    1928-01-01

    This investigation was undertaken at the Langley Memorial Aeronautical Laboratory in connection with a general research on fuel-injection for aircraft. The purpose of the investigation was to determine the factors controlling the reproducibility of spray penetration and secondary discharges after cut-off. The development of single sprays from automatic injection valves was recorded by means of special high-speed photographic apparatus capable of taking 25 consecutive pictures of the moving spray at a rate of 4,000 per second. The effect of two types of injection valves, injection-valve tube length, initial pressure in the injection-valve tube, speed of the injection control mechanism, and time of spray cut-off, on the reproducibility of spray penetration, and on secondary discharges were investigated. It was found that neither type of injection valve materially affected spray reproducibility. The initial pressure in the injection-valve tube controlled the reproducibility of spray penetrations. An increase in the initial pressure or in the length of the injection-valve tube slightly increased the spray penetration within the limits of this investigation. The speed of the injection-control mechanism did not affect the penetration. Analysis of the results indicates that secondary discharges were caused in this apparatus by pressure waves initiated by the rapid opening of the cut-off valve. The secondary discharges were eliminated in this investigation by increasing the length of the injection-valve tube. (author)

  15. Cut-off values of blood mercury concentration in relation to increased body mass index and waist circumference in Koreans.

    PubMed

    Bae, Suhyun; Park, Soo-Jung; Yeum, Kyung-Jin; Choi, Beomhee; Kim, Young-Sang; Joo, Nam-Seok

    2016-04-01

    Blood mercury (methyl-mercury) from environmental exposure may be related to inflammation in our body. We investigated the cut-off values of blood mercury concentration in relation to increased body mass index (BMI) and waist circumference. On the basis of data obtained from the Korea National Health and Nutrition Examination Survey (KNHANES, 2008-2012), 11,159 subjects (5543 males and 5616 females) were analyzed cross-sectionally. Partial correlation, linear regression, and analysis of covariance (according to the mercury quartile) tests were performed to evaluate the relationship between blood mercury and BMI or waist circumference. In addition, we determined the cut-off values of blood mercury concentration in relation to increased BMI and waist circumference in both genders. Mean values of blood mercury concentration were 5.07 ± 0.07 μg/L in males and 3.59 ± 0.04 μg/L in females. After log transformation of blood mercury, significant (p < 0.001) correlation was found between blood mercury concentration and BMI or waist circumference. BMI and waist circumference showed a significant and gradual increase as mercury quartile increased in both genders. Blood mercury concentration was weakly but significantly (p < 0.001) associated with BMI and waist circumference. Cut-off values of blood mercury concentration correlated with increased BMI and waist circumference were around 3.95 μg/L in males and 3.40 μg/L in females.

  16. Ozone transport during a cut-off low event studied in the frame of the TOASTE program

    NASA Technical Reports Server (NTRS)

    Ancellet, G.; Beekmann, M.; Papayannis, A.; Megie, G.

    1994-01-01

    A study of ozone transfer to the troposphere has been performed during two phases of the evolution of a cut-off low using both ozone vertical profiles and objective analysis of the ECMWF to compute potential vorticity distributions and air mass trajectories. Ozone profiles were measured by a ground based lidar system at the Observatoire de Haute Provence (OHP, 43 deg 55 N, 5 deg 42 E). A stratospheric ozone transport into the troposphere has been observed during a tropopause fold which occurred at the beginning of the cut-off low formation and during the erosion phase of the cut-off low. From the estimate of the maximum ozone content transferred to the troposphere, both mechanisms have the same order of magnitude of influence on the ozone flux to the troposphere. On a time scale of a few days, the correlation is very good between the potential vorticity and the ozone time evolution in the vicinity of the upper level frontal system.

  17. Development of short-form and screening cutoff point of the Smartphone Addiction Inventory (SPAI-SF).

    PubMed

    Lin, Yu-Hsuan; Pan, Yuan-Chien; Lin, Sheng-Hsuan; Chen, Sue-Huei

    2016-09-23

    Smartphone addiction is considered a form of technological addiction that has attracted increasing attention. The present study developed and validated the short-form Smartphone Addiction Inventory (SPAI-SF) and established cutoff point for screening smartphone addiction based on diagnostic criteria established by psychiatric interview. A total of 268 participants completed an online survey that collected demographic data, smartphone use behaviours, and responses to the 26-item SPAI. Each participant also completed a psychiatric interview. Confirmatory factor analysis (CFA) revealed that the 10-item SPAI-SF replicated the structure of original 26-item SPAI accurately, yielding a four-factor model consisting of compulsive behaviour, functional impairment, withdrawal, and tolerance. For maximal diagnostic accuracy, a cutoff point of 24/25 best discriminated cases of smartphone addiction from diagnostic negatives. The present findings suggest that both the 26-item SPAI and SPAI-SF manifest the four constructs of behavioural addiction and the characteristics of smartphone addiction. The cutoff point determined by psychiatrists' diagnostic interview will be useful for clinical screening and epidemiologic research.

  18. Interstellar flow longitude from pickup ion cut-off observations at 1 AU with STEREO and ACE

    NASA Astrophysics Data System (ADS)

    Möbius, E.; Lee, M. A.; Gloeckler, G.; Drews, C.; Keilbach, D.

    2016-11-01

    A precision determination of the interstellar neutral (ISN) flow direction is important in several ways. As a cardinal axis of the heliosphere it has strong leverage on the plane subtended by the ISN velocity and interstellar magnetic field vector, which controls the shape of the heliosphere and its interaction with the interstellar medium. Continuing observations of the ISN flow through the heliosphere for several decades allow the search for potential temporal variations of the ISN flow and comparison with astronomical observations. Recent efforts to obtain a consistent ISN vector and temperature with Ulysses and IBEX neutral gas observations point to remaining uncertainties and potential systematic effects. In particular, IBEX measurements provide a very precise relation between ISN flow longitude and speed via the hyperbolic trajectory equation, but they contain larger uncertainties along the parameter tube defined by this relation. The pickup ion (PUI) cut-off variation with ecliptic longitude at 1 AU can provide a complementary determination of the ISN flow longitude with high precision. We compare STEREO PLASTIC and ACE SWICS observations with a simple analytical model of the cut-off. We perform a Pearson correlation analysis of the cut-off as a function of ecliptic longitude with its mirrored function and obtain the symmetry axis with a statistical uncertainty <0.1°. Here we test variations of this value due to Poisson fluctuations in the original data with simulations and due to systematic effects with multi year and location ACE SWICS and STEREO PLASTIC samples.

  19. Effects of azimuth-symmetric acceptance cutoffs on the measured asymmetry in unpolarized Drell-Yan fixed-target experiments

    NASA Astrophysics Data System (ADS)

    Bianconi, A.; Bussa, M. P.; Destefanis, M.; Ferrero, L.; Greco, M.; Maggiora, M.; Spataro, S.

    2013-04-01

    Fixed-target unpolarized Drell-Yan experiments often feature an acceptance depending on the polar angle of the lepton tracks in the laboratory frame. Typically leptons are detected in a defined angular range, with a dead zone in the forward region. If the cutoffs imposed by the angular acceptance are independent of the azimuth, at first sight they do not appear dangerous for a measurement of the cos(2 φ) asymmetry, which is relevant because of its association with the violation of the Lam-Tung rule and with the Boer-Mulders function. On the contrary, direct simulations show that up to 10 percent asymmetries are produced by these cutoffs. These artificial asymmetries present qualitative features that allow them to mimic the physical ones. They introduce some model dependence in the measurements of the cos(2 φ) asymmetry, since a precise reconstruction of the acceptance in the Collins-Soper frame requires a Monte Carlo simulation, that in turn requires some detailed physical input to generate event distributions. Although experiments in the eighties seem to have been aware of this problem, the possibility of using the Boer-Mulders function as an input parameter in the extraction of transversity has much increased the requirements of precision on this measurement. Our simulations show that the safest approach to these measurements is a strong cutoff on the Collins-Soper polar angle. This reduces statistics, but does not necessarily decrease the precision in a measurement of the Boer-Mulders function.

  20. Multi-aquifer pumping test to determine cutoff wall length for groundwater flow control during site excavation in Tokyo, Japan

    NASA Astrophysics Data System (ADS)

    Miyake, Noriharu; Kohsaka, Nobuaki; Ishikawa, Akira

    2008-08-01

    Multi-aquifer pumping tests, using a multi-screen pumping well and multi-level piezometers, were carried out for groundwater flow control in a large-scale excavation site in Tokyo, Japan. The site was underlain by multi-layered confined aquifers. In the tests, pumping was carried out using a multi-aquifer pumping well in which a screen depth was chosen arbitrarily. Changes in groundwater pressure heads in each aquifer were measured at each screen position of the multi-aquifer pumping well. Hydraulic conductivity ( K) and specific storage ( S s) of not only aquifers, but also for low permeability layers between the aquifers, were estimated using the Cooper-Jacob method, and calibrated by a finite element method (FEM) groundwater model. Four different cutoff wall lengths were assumed for final excavation depth, and correlations among wall length, pumping discharge and drawdown at the back of the cutoff wall were obtained from simulations using the K and S s parameters in the FEM model. Then, the most suitable wall length was selected based on the simulated correlations considering environmental condition, construction period and cost of the cutoff wall.

  1. Insulin sensitivity indices: a proposal of cut-off points for simple identification of insulin-resistant subjects.

    PubMed

    Radikova, Z; Koska, J; Huckova, M; Ksinantova, L; Imrich, R; Vigas, M; Trnovec, T; Langer, P; Sebokova, E; Klimes, I

    2006-05-01

    Demanding measurement of insulin sensitivity using clamp methods does not simplify the identification of insulin resistant subjects in the general population. Other approaches such as fasting- or oral glucose tolerance test-derived insulin sensitivity indices were proposed and validated with the euglycemic clamp. Nevertheless, a lack of reference values for these indices prevents their wider use in epidemiological studies and clinical practice. The aim of our study was therefore to define the cut-off points of insulin resistance indices as well as the ranges of the most frequently obtained values for selected indices. A standard 75 g oral glucose tolerance test was carried out in 1156 subjects from a Caucasian rural population with no previous evidence of diabetes or other dysglycemias. Insulin resistance/sensitivity indices (HOMA-IR, HOMA-IR2, ISI Cederholm, and ISI Matsuda) were calculated. The 75th percentile value as the cut-off point to define IR corresponded with a HOMA-IR of 2.29, a HOMA-IR2 of 1.21, a 25th percentile for ISI Cederholm, and ISI Matsuda of 57 and 5.0, respectively. For the first time, the cut-off points for selected indices and their most frequently obtained values were established for groups of subjects as defined by glucose homeostasis and BMI. Thus, insulin-resistant subjects can be identified using this simple approach.

  2. Amphetamines and 3,4-methylendioxymetamphetamine (MDMA): evaluation of KIMS (kinetic interaction of microparticles in solution) assay at two cut-off levels.

    PubMed

    Marchioro, Lucio; Bassetto, Flavia; Dall'Olio, Giuliano; Tedeschi, Luciano; Castagna, Franca; Plebani, Mario

    2004-05-01

    Two screening methods for the assay of amphetamines and their derivatives have been applied to the same analytical instrument for their evaluation. In addition to an assay at a cut-off of 1000 microg/l, a new specific reagent was evaluated for an ultra-sensitive assay of amphetamines and 3,4-methylendioxymetamphetamine with a cut-off of 300 microg/l. The assay confirmation was performed using high-performance liquid chromatography and gas chromatography/ mass spectrometry techniques. The results were positive for both screening methods, confirming the efficacy of two simultaneous methods with different cut-off levels.

  3. Aeromonas Diversity and Antimicrobial Susceptibility in Freshwater—An Attempt to Set Generic Epidemiological Cut-Off Values

    PubMed Central

    Baron, Sandrine; Granier, Sophie A.; Larvor, Emeline; Jouy, Eric; Cineux, Maelan; Wilhelm, Amandine; Gassilloud, Benoit; Le Bouquin, Sophie; Kempf, Isabelle; Chauvin, Claire

    2017-01-01

    The importance of the role of environment in the dissemination of antimicrobial resistant bacteria is now well recognized. Thus, bacterial indicators to monitor the phenomena are required. The Aeromonas genus is autochthonous in the aquatic environment and easy to detect in any water type, such as freshwater, or wastewater. These microorganisms are also causing infections in humans and animals (including fish). Furthermore, as Aeromonas spp. is able to acquire antimicrobial resistance mechanisms, it is candidate for indicator bacteria to follow antimicrobial resistance dissemination in aquatic environments. Unfortunately, to date, interpretation criteria for Aeromonas spp. for antimicrobial susceptibility tests are scarce in the literature. No epidemiological cut-off values for Aeromonas are currently available at EUCAST to interpret Minimum Inhibitory Concentrations (MIC). The only interpretation criteria available are clinical breakpoints from CLSI that are adapted from Enterobacteriaceae. Based on the results of MIC distributions obtained for a collection of environmental isolates of Aeromonas, this study aimed at proposing tentative epidemiological cut-off values (COWT) for Aeromonas spp. assessing whether the genus is an acceptable level of definition. Thus, 233 isolates collected from 16 rivers were identified at species level using Maldi-Tof (Bruker). Eleven different species were identified, the most abundant were A. bestiarum (n = 54), A. salmonicida (n = 45), A. sobria (n = 41), and A. eucrenophila (n = 37). 96-well micro-plates containing different concentrations of 15 antimicrobials, namely cefotaxime, ceftazidime, chloramphenicol, colistin, enrofloxacin, erythromycin, florfenicol, flumequine, gentamicin, nalidixic acid, oxolinic acid, streptomycin, temocillin, tetracycline, and trimethoprim-sulfamethoxazole, were prepared. The broth micro-dilution method was used to determine the antimicrobial susceptibility of each isolate. The estimation of COWT

  4. Bronchodilator response cut-off points and FEV 0.75 reference values for spirometry in preschoolers

    PubMed Central

    Burity, Edjane Figueiredo; Pereira, Carlos Alberto de Castro; Jones, Marcus Herbert; Sayão, Larissa Bouwman; de Andrade, Armèle Dornelas; de Britto, Murilo Carlos Amorim

    2016-01-01

    ABSTRACT Objective: To determine the cut-off points for FEV1, FEV0.75, FEV0.5, and FEF25-75% bronchodilator responses in healthy preschool children and to generate reference values for FEV0.75. Methods: This was a cross-sectional community-based study involving children 3-5 years of age. Healthy preschool children were selected by a standardized questionnaire. Spirometry was performed before and after bronchodilator use. The cut-off point of the response was defined as the 95th percentile of the change in each parameter. Results: We recruited 266 children, 160 (60%) of whom were able to perform acceptable, reproducible expiratory maneuvers before and after bronchodilator use. The mean age and height were 57.78 ± 7.86 months and 106.56 ± 6.43 cm, respectively. The success rate for FEV0.5 was 35%, 68%, and 70% in the 3-, 4-, and 5-year-olds, respectively. The 95th percentile of the change in the percentage of the predicted value in response to bronchodilator use was 11.6%, 16.0%, 8.5%, and 35.5% for FEV1, FEV0.75, FEV0.5, and FEF25-75%, respectively. Conclusions: Our results provide cut-off points for bronchodilator responsiveness for FEV1, FEV0.75, FEV0.5, and FEF25-75% in healthy preschool children. In addition, we proposed gender-specific reference equations for FEV0.75. Our findings could improve the physiological assessment of respiratory function in preschool children. PMID:27812631

  5. Correlation of Real Time PCR Cycle Threshold Cut-Off with Bordetella pertussis Clinical Severity.

    PubMed

    Bolotin, Shelly; Deeks, Shelley L; Marchand-Austin, Alex; Rilkoff, Heather; Dang, Vica; Walton, Ryan; Hashim, Ahmed; Farrell, David; Crowcroft, Natasha S

    2015-01-01

    Bordetella pertussis testing performed using real-time polymerase chain reaction (RT-PCR) is interpreted based on a cycle threshold (Ct) value. At Public Health Ontario Laboratories (PHOL), a Ct value <36 is reported as positive, and Ct values ≥36 and <40 are reported as indeterminate. PHOL reported indeterminate results to physicians and public health units until May 2012, after which these results were only reported to physicians. We investigated the association between Ct value and disease symptom and severity to examine the significance of indeterminate results clinically, epidemiologically and for public health reporting. B. pertussis positive and indeterminate RT-PCR results were linked to pertussis cases reported in the provincial Integrated Public Health Information System (iPHIS), using deterministic linkage. Patients with positive RT-PCR results had a lower median age of 10.8 years compared to 12.0 years for patients with indeterminate results (p = 0.24). Hospitalized patients had significantly lower Ct values than non-hospitalized patients (median Ct values of 20.7 vs. 31.6, p<0.001). The proportion of patients reporting the most indicative symptoms of pertussis did not differ between patients with positive vs. indeterminate RT-PCR results. Taking the most indicative symptoms of pertussis as the gold-standard, the positive predictive value of the RT-PCR test was 68.1%. RT-PCR test results should be interpreted in the context of the clinical symptoms, age, vaccination status, prevalence, and other factors. Further information on interpretation of indeterminate RT-PCR results may be needed, and the utility of reporting to public health practitioners should be re-evaluated.

  6. F-15 inlet/engine test techniques and distortion methodologies studies. Volume 5: Effect of filter cutoff frequency on turbulence plots

    NASA Technical Reports Server (NTRS)

    Stevens, C. H.; Spong, E. D.; Hammock, M. S.

    1978-01-01

    The effect of filter cutoff frequency on turbulence plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle.

  7. High frequency cut-off in 1/f conductivity noise of hole-doped La1-x Ca x MnO3 manganite single crystals

    NASA Astrophysics Data System (ADS)

    Przybytek, Jacek; Fink-Finowicki, Jan; Puźniak, Roman; Jung, Grzegorz

    2016-05-01

    High frequency bias and temperature-dependent Lorentzian cut-off has been observed in the 1/f spectra of the conductivity fluctuations in low hole-doped ferromagnetic insulating La1-x Ca x MnO3 manganite at low temperatures. The cut-off frequency depends on dc current bias and temperature. The high frequency cut-off has been tentatively associated with intrinsic limits of the appearance of 1/f noise in the hopping regime of the Coulomb glass state. The assumption is validated by the fact that the Efros-Shklovskii temperature {{T}\\text{ES}} , estimated from the fit of the model to the experimentally measured temperature dependence of the cut-off frequency, has the same value as the temperature {{T}\\text{ES}} evaluated independently from the temperature dependence of the resistivity in the corresponding temperature range.

  8. On-chip waveguide isolator based on bismuth iron garnet operating via nonreciprocal single-mode cutoff.

    PubMed

    Drezdzon, Samuel M; Yoshie, Tomoyuki

    2009-05-25

    We analyze an on-chip optical isolator based on direction dependent single-mode cutoff, which is described in 1D and 2D momentum space. Isolation is shown using 3D finite difference time domain (FDTD) where the magnetization is represented by imaginary off-diagonal permittivity tensor elements. The isolator designs are optimized using perturbation theory, which successfully predicts increased isolation for rib waveguides and structures with non-magnetic dielectric layers. Our isolators are based on bismuth iron garnet and its compatible substrates; an isolation ratio of 10.7 dB/mm is achieved for TM modes.

  9. Material-dependent high-frequency current fluctuations of cathodicvacuum arcs: Evidence for the ecton cutoff of the fractal model

    SciTech Connect

    Anders, Andre; Oks, Efim

    2005-12-22

    Current fluctuations of cathodic arcs were recorded withhigh analog bandwidth (up to 1 GHz) and fast digital sampling (up to 5Gsamples/sec). The power spectral density of the arc current wasdetermined by fast Fourier transform clearly showing material dependent,non-linear features in the frequency domain. These features can beassociated with the non-linear impedance of the conducting channelbetween cathode and anode, driven by the explosive nature of electronemission and plasma formation. The characteristic times of less than 100ns can be associated with individual explosive processes, "ectons," andtherefore represent the short-time physical cutoff for the fractal modelof cathodic arcs.

  10. Appropriate Body Mass Index and Waist Circumference Cutoff for Overweight and Central Obesity among Adults in Cambodia

    PubMed Central

    An, Yom; Yi, Siyan; Fitzpatrick, Annette; Gupta, Vinay; Prak, Piseth Raingsey; Oum, Sophal; LoGerfo, James P.

    2013-01-01

    Background Body mass index (BMI) and waist circumference (WC) are used in risk assessment for the development of non-communicable diseases (NCDs) worldwide. Within a Cambodian population, this study aimed to identify an appropriate BMI and WC cutoff to capture those individuals that are overweight and have an elevated risk of vascular disease. Methodology/Principal Findings We used nationally representative cross-sectional data from the STEP survey conducted by the Department of Preventive Medicine, Ministry of Health, Cambodia in 2010. In total, 5,015 subjects between age 25 and 64 years were included in the analyses. Chi-square, Fisher’s Exact test and Student t-test, and multiple logistic regression were performed. Of total, 35.6% (n = 1,786) were men, and 64.4% (n = 3,229) were women. Mean age was 43.0 years (SD = 11.2 years) and 43.6 years (SD = 10.9 years) for men and women, respectively. Significant association of subjects with hypertension and hypercholesterolemia was found in those with BMI ≥23.0 kg/m2 and with WC >80.0 cm in both sexes. The Area Under the Curve (AUC) from Receiver Operating Characteristic curves was significantly greater in both sexes (all p-values <0.001) when BMI of 23.0 kg/m2 was used as the cutoff point for overweight compared to that using WHO BMI classification for overweight (BMI ≥25.0 kg/m2) for detecting the three cardiovascular risk factors. Similarly, AUC was also significantly higher in men (p-value <0.001) when using WC of 80.0 cm as the cutoff point for central obesity compared to that recommended by WHO (WC ≥94.0 cm in men). Conclusion Lower cutoffs for BMI and WC should be used to identify of risks of hypertension, diabetes, and hypercholesterolemia for Cambodian aged between 25 and 64 years. PMID:24205019

  11. Improving the intrinsic cut-off frequency of gate-all-around quantum-wire transistors without channel length scaling

    NASA Astrophysics Data System (ADS)

    Benali, A.; Traversa, F. L.; Albareda, G.; Aghoutane, M.; Oriols, X.

    2013-04-01

    Progress in high-frequency transistors is based on reducing electron transit time, either by scaling their lengths or by introducing materials with higher electron mobility. For gate-all-around quantum-wire transistors with lateral dimensions similar or smaller than their length, a careful analysis of the displacement current reveals that a time shorter than the transit time controls their high-frequency performance. Monte Carlo simulations of such transistors with a self-consistent solution of the 3D Poisson equation clearly show an improvement of the intrinsic cut-off frequency when their lateral areas are reduced, without length scaling.

  12. Cut-Off Value of Total Adiponectin for Managing Risk of Developing Metabolic Syndrome in Male Japanese Workers

    PubMed Central

    Hata, Akiko; Yonemoto, Koji; Shikama, Yosuke; Aki, Nanako; Kosugi, Chisato; Tamura, Ayako; Ichihara, Takako; Minagawa, Takako; Kuwamura, Yumi; Miyoshi, Masashi; Nakao, Takayuki; Funaki, Makoto

    2015-01-01

    Aim To determine the optimal cut-off value of serum total adiponectin for managing the risk of developing metabolic syndrome (MetS) in male Japanese workers. Methods A total of 365 subjects without MetS aged 20–60 years were followed up prospectively for a mean of 3.1 years. The accelerated failure-time model was used to estimate time ratio (TR) and cut-off value for developing MetS. Results During follow-up, 45 subjects developed MetS. Age-adjusted TR significantly declined with decreasing total adiponectin level (≤ 4.9, 5.0–6.6, 6.7–8.8 and ≥ 8.9 μg/ml, P for trend = 0.003). In multivariate analyses, TR of MetS was 0.12 (95% CI 0.02–0.78; P = 0.03) in subjects with total adiponectin level of 5.0–6.6 μg/ml, and 0.15 (95% CI 0.02–0.97; P = 0.047) in subjects with total adiponectin level ≤ 4.9 μg/ml compared with those with total adiponectin level ≥ 8.9 μg/ml. The accelerated failure-time model showed that the optimal cut-off value of total adiponectin for managing the risk of developing MetS was 6.2 μg/ml. In the multivariate-adjusted model, the mean time to the development of MetS was 78% shorter for total adiponectin level ≤ 6.2 μg/ml compared with > 6.2 μg/ml (TR 0.22, 95% CI: 0.08–0.64, P = 0.005). Conclusion Our findings suggest that the cut-off value for managing the risk of developing MetS is 6.2 μg/ml in male Japanese workers. Subjects with total adiponectin level ≤ 6.2 μg/ml developed MetS more rapidly than did those with total adiponectin level > 6.2 μg/ml. PMID:25705909

  13. Elevated d-dimer cut-off values for computed tomography pulmonary angiography—d-dimer correlates with location of embolism

    PubMed Central

    Kubak, Mateuzs Piotr; Borthne, Arne; Ruud, Espen Asak; Ashraf, Haseem

    2016-01-01

    Background Acute pulmonary embolism (APE) is a potentially fatal condition, and making a timely diagnosis can be challenging. Computed tomography pulmonary angiography (CTPA) has become the modality of choice, and this contributes to the increasing load on emergency room CT scanners. Our purpose was to investigate whether an elevated d-dimer cut-off could reduce the demand for CTPA while maintaining a high sensitivity and negative predictive value (NPV). Methods We retrospectively reviewed all patients referred for CTPA with suspicion of APE in 2012, and collected d-dimer values and CTPA results. We investigated the diagnostic performance of d-dimer using a 0.5 mg/L cut-off and an age adjusted cut-off. We also evaluated a new and elevated cut-off. Cases were categorized according to their CTPA result into: no embolism, peripheral embolism, lobar embolism and central embolism. Finally we investigated a possible correlation between d-dimer values and location of embolism. Results We included 1,051 CTPAs, from which 216 (21%) showed pulmonary embolism. There were concomitant d-dimer analyses in 822 CTPA examinations. The current 0.5 mg/L cut-off achieved a sensitivity and NPV of 99%. The age-adjusted cut-off achieved a sensitivity and NPV of 98%, and our suggested cut-off of 0.9 mg/L achieved a sensitivity and NPV of 97%. Conclusions We conclude that the elevated d-dimer cut-off of 0.9 mg/L achieved a high sensitivity and NPV, while reducing the number of CTPA by 27%. The correlation between d-dimer values and location of embolisms supports the suggestion of an elevated d-dimer value. PMID:27386486

  14. A Method of Implementing Cutoff Conditions for Saturn V Lunar Missions Out of Earth Parking Orbit Assuming a Continuous Ground Launch Window

    NASA Technical Reports Server (NTRS)

    Cooper, F. D.

    1965-01-01

    A method of implementing Saturn V lunar missions from an earth parking orbit is presented. The ground launch window is assumed continuous over a four and one-half hour period. The iterative guidance scheme combined with a set of auxiliary equations that define suitable S-IVB cutoff conditions, is the approach taken. The four inputs to the equations that define cutoff conditions are represented as simple third-degree polynomials as a function of ignition time. Errors at lunar arrival caused by the separate and combined effects of the guidance equations, cutoff conditions, hypersurface errors, and input representations are shown. Vehicle performance variations and parking orbit injection errors are included as perturbations. Appendix I explains how aim vectors were computed for the cutoff equations. Appendix II presents all guidance equations and related implementation procedures. Appendix III gives the derivation of the auxiliary cutoff equations. No error at lunar arrival was large enough to require a midcourse correction greater than one meter per second assuming a transfer time of three days and the midcourse correction occurs five hours after injection. Since this result is insignificant when compared to expected hardware errors, the implementation procedures presented are adequate to define cutoff conditions for Saturn V lunar missions.

  15. Low-energy physics of the t -J model in d =∞ using extremely correlated Fermi liquid theory: Cutoff second-order equations

    NASA Astrophysics Data System (ADS)

    Shastry, B. Sriram; Perepelitsky, Edward

    2016-07-01

    We present the results for the low-energy properties of the infinite-dimensional t -J model with J =0 , using O (λ2) equations of the extremely correlated Fermi liquid formalism. The parameter λ ∈[0 ,1 ] is analogous to the inverse spin parameter 1 /(2 S ) in quantum magnets. The present analytical scheme allows us to approach the physically most interesting regime near the Mott insulating state n ≲1 . It overcomes the limitation to low densities n ≲0.7 of earlier calculations, by employing a variant of the skeleton graph expansion, and a high-frequency cutoff that is essential for maintaining the known high-T entropy. The resulting quasiparticle weight Z , the low ω ,T self-energy, and the resistivity are reported. These are quite close at all densities to the exact numerical results of the U =∞ Hubbard model, obtained using the dynamical mean field theory. The present calculation offers the advantage of generalizing to finite T rather easily, and allows the visualization of the loss of coherence of Fermi liquid quasiparticles by raising T . The present scheme is generalizable to finite dimensions and a nonvanishing J .

  16. Accelerating potential of mean force calculations for lipid membrane permeation: System size, reaction coordinate, solute-solute distance, and cutoffs

    NASA Astrophysics Data System (ADS)

    Nitschke, Naomi; Atkovska, Kalina; Hub, Jochen S.

    2016-09-01

    Molecular dynamics simulations are capable of predicting the permeability of lipid membranes for drug-like solutes, but the calculations have remained prohibitively expensive for high-throughput studies. Here, we analyze simple measures for accelerating potential of mean force (PMF) calculations of membrane permeation, namely, (i) using smaller simulation systems, (ii) simulating multiple solutes per system, and (iii) using shorter cutoffs for the Lennard-Jones interactions. We find that PMFs for membrane permeation are remarkably robust against alterations of such parameters, suggesting that accurate PMF calculations are possible at strongly reduced computational cost. In addition, we evaluated the influence of the definition of the membrane center of mass (COM), used to define the transmembrane reaction coordinate. Membrane-COM definitions based on all lipid atoms lead to artifacts due to undulations and, consequently, to PMFs dependent on membrane size. In contrast, COM definitions based on a cylinder around the solute lead to size-independent PMFs, down to systems of only 16 lipids per monolayer. In summary, compared to popular setups that simulate a single solute in a membrane of 128 lipids with a Lennard-Jones cutoff of 1.2 nm, the measures applied here yield a speedup in sampling by factor of ˜40, without reducing the accuracy of the calculated PMF.

  17. Active sources in the cutoff of centrifugal fans to reduce the blade tones at higher-order duct mode frequencies

    NASA Astrophysics Data System (ADS)

    Neise, W.; Koopmann, G. H.

    1991-01-01

    A previously developed (e.g., Neise and Koopmann, 1984; Koopmann et al., 1988) active noise control technique in which the unwanted acoustic signals from centrifugal fans are suppressed by placing two externally driven sources near the cutoff of the casing was applied to the frequency region where not only plane sound waves are propagational in the fan ducts but also higher-order acoustic modes. Using a specially designed fan noise testing facility, the performance of two fans (280-mm impeller diam and 508 mm diam) was monitored with static pressure taps mounted peripherally around the inlet nozzle. Experimental results show that the aerodynamically generated source pressure field around the cutoff is too complex to be successfully counterimaged by only two active sources introduced in this region. It is suggested that, for an efficient application of this noise control technique in the higher-order mode frequency regime, it is neccessary to use an active source involving larger number of individually driven loudspeakers.

  18. Kinetic Isotope Effects from QM/MM Subset Hessians: "Cut-Off" Analysis for SN2 Methyl Transfer in Solution.

    PubMed

    Williams, Ian H

    2012-02-14

    Isotopic partition-function ratios and kinetic isotope effects for reaction of S-adenosylmethionine with catecholate in water are evaluated using a subset of 324 atoms within its surrounding aqueous environment at the AM1/TIP3P level. Two alternative methods for treating motion in the six librational degrees of freedom of the subset atoms relative to their environment are compared. A series of successively smaller subset Hessians are generated by cumulative deletion of rows and columns from the initial 972 × 972 Hessian. We find that it is better to treat these librations as vibrations than as translations and rotations and that there is no need to invoke the Teller-Redlich product rule. The validity of "cut-off" procedures for computation of isotope effects with truncated atomic subsets is assessed: to ensure errors in ln(KIE) < 1% (or 2% for the quantum-corrected KIE) for all isotopic substitutions considered, it is necessary to use a less-restrictive procedure than is suggested by the familiar two-bond cutoff rule.

  19. Interstellar flow direction from pickup ion cut-off dependence on longitude, flow and solar wind speed

    NASA Astrophysics Data System (ADS)

    Möbius, Eberhard; Lee, Martin A.; Drews, Christian; Gloeckler, George

    2016-03-01

    The precise interstellar neutral (ISN) flow direction is important because of its strong leverage on the plane subtended by the ISN and magnetic field vectors, which controls the heliospheric shape and interaction with the interstellar medium. IBEX measurements provide a very precise relation between ISN flow longitude and speed via the hyperbolic trajectory equation, forming a 4-dimensional tube in the ISN parameter space, with substantially larger uncertainty along this tube and thus for the longitude alone. As demonstrated before, the interstellar pickup ion (PUI) cut-off speed is a function of the ratio of the radial ISN flow component and the solar wind speed at the observer location. The former is largest precisely upwind and decreases symmetrically with the angle from the upwind direction. Using this functional dependence and the observed solar wind speed, the PUI cut-off can be constructed solely as a function of the ISN flow longitude. From ACE SWICS and STEREO PLASTIC, data sets that span 18+ years are available. We will show, in particular, that by selecting observations for local interplanetary magnetic fields perpendicular to the solar wind and transforming the observed distributions into the solar wind frame, a comparison with data can be devised that is much less sensitive to PUI production and transport effects than methods that rely on pickup ion fluxes.

  20. An Evaluation of the Permittivity of Two Different Rock Types Using Microwave Resonator and Waveguide Cutoff Principles

    NASA Astrophysics Data System (ADS)

    Olkkonen, Martta-Kaisa; Eskelinen, Pekka; Huuskonen-Snicker, Eeva; Pellinen, Terhi; Olmos Martinez, Pablo

    2015-01-01

    Methods of measuring the complex permittivity of different rock types are demonstrated in the frequency range from 6 GHz to 17 GHz. The used methods are based on the cylindrical resonator and waveguide cutoff frequency principles. This study is part of a larger research project that aims to characterize the electrical properties of asphalt for road surveying purposes. The studied rock types are metavolcanic rock with intermediate composition and pegmatite. The permittivity values gained with the resonator method are 6.2 for the metavolcanic rock and 4.5 for the pegmatite rock type, whereas the imaginary parts are 0.04 and 0.02. The permittivity values gained with the cutoff frequency method are 6.17 and 4.76 respectively. A reference measurement was made only for the metavolcanic rock in a transmission configuration with two antennas and the permittivity result was 6.21. The three different methods provide consistent permittivity values and are suitable for reliable permittivity evaluation.

  1. Determination of the accuracy and optimal cut-off point for ELISA test in diagnosis of human brucellosis in Iran.

    PubMed

    Hasibi, Mehrdad; Jafari, Sirus; Mortazavi, Habibollah; Asadollahi, Marjan; Esmaeeli Djavid, Gholamreza

    2013-01-01

    In endemic area the most challenging problem for brucellosis is to find a reliable diagnostic method. In this case-control study, we investigated the accuracy of ELISA test for diagnosis of human brucellosis and determined the optimal cut-off value for ELISA results in Iran. The laboratory diagnosis of brucellosis was performed by blood isolation of Brucella organism with a BACTEC 9240 system and/or detection of Brucella antibodies by standard agglutination test (titer ≥ 1:160). Serum level of ELISA IgG and ELISA IgM from 56 confirmed cases of brucellosis and 126 controls were compared with each other by Box plot graph and Receiver Operating Characteristic (ROC) curve. Box plot graphs showed the high degree of dispersion for IgG and IgM data in patients compared with all controls. We observed partially overlapping for IgM data (not for IgG) between cases and controls in graphs. The area under ROC curve for distinguishing between cases and controls was larger for IgG compared to IgM. Based on results of this study, ELISA IgG test was more reliable than ELISA IgM test in diagnosis of human brucellosis in Iran. Using a cut-off of 10 IU/ml and 50 IU/ml had most sensitivity (92.9%) and most specificity (100%) for ELISA IgG test, respectively.

  2. Cut-off scaling of high-harmonic generation driven by a femtosecond visible optical parametric amplifier

    NASA Astrophysics Data System (ADS)

    Cirmi, Giovanni; Lai, Chien-Jen; Granados, Eduardo; Huang, Shu-Wei; Sell, Alexander; Hong, Kyung-Han; Moses, Jeffrey; Keathley, Phillip; Kärtner, Franz X.

    2012-10-01

    We studied high-harmonic generation (HHG) in Ar, Ne and He gas jets using a broadly tunable, high-energy optical parametric amplifier (OPA) in the visible wavelength range. We optimized the noncollinear OPA to deliver tunable, femtosecond pulses with 200-500 µJ energy at the 1 kHz repetition rate with excellent spatiotemporal properties, suitable for HHG experiments. By tuning the central wavelength of the OPA while keeping other parameters (energy, duration and beam size) constant, we experimentally studied the scaling law of cut-off energy with the driver wavelength in helium. Our measurements show a λ1.7 + 0.2 dependence of the HHG cut-off photon energy over the full visible range in agreement with previous experiments of near- and mid-IR wavelengths. By tuning the central wavelength of the driver source, the high-order harmonic spectra in the extreme ultraviolet cover the full range of photon energy between ˜25 and ˜100 eV. Due to the high coherence intrinsic in HHG, as well as the broad and continuous tunability in the extreme UV range, a high energy, high repetition rate version of this source might be an ideal seed for free electron lasers.

  3. A Cutoff in the X-Ray Fluctuation Power Density Spectrum of the Seyfert 1 Galaxy NGC 3516

    NASA Technical Reports Server (NTRS)

    Edelson, Rick; Nandra, Kirpal

    1999-01-01

    During 1997 March-July, RXTE observed the bright, strongly variable Seyfert 1 galaxy NGC 3516 once every approx. 12.8 hr for 4.5 months and nearly continuously (with interruptions due to SAA passage but not Earth occultation) for a 4.2 day period in the middle. These were followed by ongoing monitoring once every approx. 4.3 days. These data are used to construct the first well-determined X-ray fluctuation power density spectrum (PDS) of an active galaxy to span more than 4 decades of usable temporal frequency. The PDS shows no signs of any strict or quasi-periodicity, but does show a progressive flattening of the power-low slope from -1.74 at short time scales to -0.73 at longer time scales. This is the clearest observation to date of the long-predicted cutoff in the PDS. The characteristic variability time scale corresponding to this cutoff temporal frequency is approx. 1 month. Although it is unclear how this time scale may be interpreted in terms of a physical size or process, there are several promising candidate models. The PDS appears similar to those seen for Galactic black hole candidates such as Cyg X-1, suggesting that these two classes of objects with very different luminosities and putative black hole masses (differing by more than a factor of 10(exp 5)) may have similar X-ray generation processes and structures.

  4. STS-114: Engine Cut-Off Sensors Are a No-Go: Teaching Notes for NASA Case Study

    NASA Technical Reports Server (NTRS)

    Ransom, Khadijah S.; Johnson, Grace K.

    2013-01-01

    This case study format is intended to simulate the experience of facing the same difficult challenges and making the same critical decisions as managers, engineers, and scientists in the Space Shuttle Program. It has been designed for use in the classroom setting to help students develop skills related to decision-making. Students will read about the engine cut-off sensor anomaly which created challenges during the STS-114 mission and have the opportunity to make decisions as lead NASA engineers and Mission Management Team members. Included within this document are three case study presentation options - class discussion, group activity, and open-ended research. Please read the full case prior to in-class presentation to allow ample time for students' analysis and reflection, as well as to prepare additional questions. activities or exercises, material selection, etc. Depending upon the setting of your presentation and the number of participants, please choose at least one presentation format beforehand and plan accordingly. You may expect the following learning objectives by using the proposed formats. Learning Objectives: To enable students to experience the responsibilities of NASA management, engineers, and analysis; to discover possible procedures for investigating system anomalies; to become familiar with the liquid hydrogen low level engine cut-off sensor, including its function, connecting components, and location within the Space Shuttle; and to encourage critical analysis and stimulating discussion of Space Shuttle mission challenges.

  5. Clinical Applicability and Cutoff Values for an Unstructured Neuropsychological Assessment Protocol for Older Adults with Low Formal Education

    PubMed Central

    de Paula, Jonas Jardim; Bertola, Laiss; Ávila, Rafaela Teixeira; Moreira, Lafaiete; Coutinho, Gabriel; de Moraes, Edgar Nunes; Bicalho, Maria Aparecida Camargos; Nicolato, Rodrigo; Diniz, Breno Satler; Malloy-Diniz, Leandro Fernandes

    2013-01-01

    Background and Objectives The neuropsychological exam plays a central role in the assessment of elderly patients with cognitive complaints. It is particularly relevant to differentiate patients with mild dementia from those subjects with mild cognitive impairment. Formal education is a critical factor in neuropsychological performance; however, there are few studies that evaluated the psychometric properties, especially criterion related validity, neuropsychological tests for patients with low formal education. The present study aims to investigate the validity of an unstructured neuropsychological assessment protocol for this population and develop cutoff values for clinical use. Methods and Results A protocol composed by the Rey-Auditory Verbal Learning Test, Frontal Assessment Battery, Category and Letter Fluency, Stick Design Test, Clock Drawing Test, Digit Span, Token Test and TN-LIN was administered to 274 older adults (96 normal aging, 85 mild cognitive impairment and 93 mild Alzheimer`s disease) with predominantly low formal education. Factor analysis showed a four factor structure related to Executive Functions, Language/Semantic Memory, Episodic Memory and Visuospatial Abilities, accounting for 65% of explained variance. Most of the tests showed a good sensitivity and specificity to differentiate the diagnostic groups. The neuropsychological protocol showed a significant ecological validity as 3 of the cognitive factors explained 31% of the variance on Instrumental Activities of Daily Living. Conclusion The study presents evidence of the construct, criteria and ecological validity for this protocol. The neuropsychological tests and the proposed cutoff values might be used for the clinical assessment of older adults with low formal education. PMID:24066031

  6. Accuracy of cut-off value by measurement of third molar index: Study of a Colombian sample.

    PubMed

    De Luca, Stefano; Aguilar, Lina; Rivera, Marcela; Palacio, Luz Andrea Velandia; Riccomi, Giulia; Bestetti, Fiorella; Cameriere, Roberto

    2016-04-01

    The aim of this cross-sectional study was to test the accuracy of cut-off value of 0.08 by measurement of third molar index (I3M) in assessing legal adult age of 18 years in a sample of Colombian children and young adults. Digital orthopantomographs of 288 Colombian children and young adults (163 girls and 125 boys), aged between 13 and 22 years, were analysed. Concordance correlation coefficient (ρc) and κ statistics (Cohen's Kappa coefficient) showed that repeatability and reproducibility are high for both intra- and inter-observer error. κ statistics for intra- and inter-observer agreement in decision on adult or minor was 0.913 and 0.877, respectively. Age distribution gradually decreases as I3M increases in both girls and boys. For girls, the sensitivity test was 95.1% (95% CI 87.1%-95%) and specificity was 93.8% (95% CI 87.1%-98.8%). The proportion of correctly classified individuals was 95.1%. For boys, the sensitivity test was 91.7% (95% CI 85.1%-96.8%) and specificity was 90.6% (95% CI 82.1%-97.8%). The proportion of correctly classified individuals was 89.7%. The cut-off value of 0.08 is highly useful to determine if a subject is 18 years of age or older or not.

  7. Extending the high-order harmonic generation cutoff by means of self-phase-modulated chirped pulses

    NASA Astrophysics Data System (ADS)

    Neyra, E.; Videla, F.; Pérez-Hernández, J. A.; Ciappina, M. F.; Roso, L.; Torchia, G. A.

    2016-11-01

    In this letter we propose a complementary approach to extend the cutoff in high-order harmonic generation (HHG) spectra beyond the well established limits. Inspired by techniques normally used in the compression of ultrashort pulses and supercontinuum generation, we show this extension can be achieved by means of a nonlinear phenomenon known as self-phase-modulation (SPM). We demonstrated that relatively long optical pulses, around 100 fs full-width half maximum (FWHM), non linearly chirped by SPM, are able to produce a considerable extension in the HHG cutoff. We have also shown it is possible control this extension by setting the length of the nonlinear medium. Our study was supported by the numerical integration of the time-dependent Schrödinger equation joint with a complete classical analysis of the electron dynamic. Our approach can be considered as an alternative to the utilization of optical parametric amplification (OPA) and it can be easily implemented in usual facilities with femtosecond laser systems. This technique also preserves the harmonic yield in the zone of the plateau delimited by I p   +  3.17Up law, even when the driven pulses contain larger wavelength components.

  8. Identifying the cutoff score for the PCL-R scale (psychopathy checklist-revised) in a Brazilian forensic population.

    PubMed

    Morana, Hilda Clotilde Penteado; Arboleda-Flórez, Julio; Câmara, Fernando Portela

    2005-01-06

    This study introduces a Portuguese-language version of psychopathy checklist-revised (PCL-R) [Harv. Mental Health Lett. 12 (1995) 4] in the Brazilian penitentiary system. Hare's scale is used extensively in many other countries. In a forensic population sample of 56 male subjects classified as psychopaths and non-psychopaths [Manual for the Hare Psychopathy Checklist-Revised, Multi-Health System, Toronto, 1991], 33 correlated to global personality disorder (GPD) and 23 to partial personality disorder (PPD), respectively, subtypes of antisocial personality disorder [Manual for the Hare Psychopathy Checklist-Revised, Multi-Health System, Toronto, 1991]. Subjects were evaluated through psychiatric and neurological examinations, review of judicial records, Rorschach and PCL-R. A control group of 30 subjects without criminological or psychiatric history was also evaluated with the same instruments. PCL-R validation and identification of cutoff score for Psychopathy (GPD group) was assessed through the concurrent use of the Rorschach. PCL-R cutoff score for the Brazilian population was set at 23. Sensitivity was determined at 84.8%, and reliability was high (Kappa index = 0.87). GPD individuals were characterized as clearly psychopathic according to PCL-R criteria while PPD individuals can only be considered mildly psychopathic, with better chance of rehabilitation.

  9. Repair, Evaluation, Maintenance, and Rehabilitation Research Program: Plastic Concrete Cutoff Walls for Earth Dams

    DTIC Science & Technology

    1991-03-01

    During excavation, the panel is filled with a bentonite slurry which penetrates the adjacent soil and forms a filter cake on the sides of the...ment soil . PREFACE The work described in this report was authorized by Headquarters, US Army Corps of Engineers (HQUSACE), as part of the...Geotechnical ( Soil ) Problem Area of the Repair, Evaluation, Maintenance, and Rehabilitation (REMR) Research Program from October 1987 to November 1989. The work

  10. The cut-off values of anthropometric variables for predicting mild cognitive impairment in Malaysian older adults: a large population based cross-sectional study

    PubMed Central

    Won, Huiloo; Abdul, Manaf Zahara; Mat Ludin, Arimi Fitri; Omar, Mohd Azahadi; Razali, Rosdinom; Shahar, Suzana

    2017-01-01

    Purpose Older adults are at risk of mild cognitive impairment (MCI), and simple anthropometric measurements can be used to screen for this condition. Thus, the aim of this study was to explore the cut-off values of body mass index (BMI) and waist circumference (WC) for predicting the risk of MCI in older Malaysian adults. Methods A total of 2,240 Malaysian older adults aged ≥60 years were recruited using multistage random sampling in a population based cross-sectional study. Receiver operating characteristic (ROC) curve was used to determine the cut-off values of BMI and WC with optimum sensitivity and specificity for the detection of MCI. Age, gender, years of education, smoking habit, alcohol consumption, depression, and medical conditions were used as confounding factors in this analysis. Results A BMI cut-off value of 26 kg/m2 (area under the receiver operating characteristic curve [AUC] 0.725; sensitivity 90.5%; specificity 38.8%) was appropriate in identifying the risk of getting MCI in both men and women. The optimum WC cut-offs for likelihood of MCI were 90 cm (AUC 0.745; sensitivity 78.0%; specificity 59.8%) for men and 82 cm (AUC 0.714; sensitivity 84.3%; specificity 49.7%) for women. The optimum calf circumference (CC) cut-off values for identifying MCI were 29 cm (AUC 0.731; sensitivity 72.6%; specificity 61.1%) for men and 26 cm (AUC 0.598; sensitivity 79.1%; specificity 45.3%) for women. Conclusion The cut-off values could be advocated and used as part of the screening of MCI among older Malaysian adults. There is a need to further determine the predictive values of these cut-off points on outcomes through longitudinal study design. PMID:28223785

  11. Determination of Cutoff Values for DEXA-Based Body Composition Measurements for Determining Metabolic and Cardiovascular Health

    PubMed Central

    Lang, Pierre-Olivier; Trivalle, Christophe; Vogel, Thomas; Proust, Jacques; Papazyan, Jean-Pierre; Dramé, Moustapha

    2015-01-01

    Abstract The two components of the body weight (i.e., fat mass and muscle mass) appeared to be of high interest to consider in predicting metabolic health related risks. We aimed to determine cutoff values for fat mass index (FMI) and muscle mass index (MMI), FM/MM, and BMI for metabolic and cardiovascular health. This study was a cross-sectional analysis study conducted in a center of preventive medicine. It included 616 consecutive outpatients: mean age was 56.0±10.0 years (74.6% aged ≥50), and 61.4% were female. Fat and muscle mass were obtained with dual energy X-ray absorptiometry scan analyses. Metabolically unhealthy individuals were defined as people with biological features of dyslipidemia, hyperuricemia, diabetes, and/or hepatitis steatosis. Documented hypertension and/or atherosclerosis of at least one major artery defined individuals with cardiovascular complications. Receiver-operating characteristic curve analysis revealed that the cutoff values for MMI, FMI, and FM/MM were respectively 18.8kg/m2 (sensitivity [Se]=58%; specificity [Sp]=59%), 5.5kg/m2 (Se=61%; Sp=62%), and 0.31 (Se=62%; Sp=62%) in men; and 14.1kg/m2 (Se=52%; Sp=54%), 5.5kg/m2 (Se=65%; Sp=67%), 0.39 (Se=73%; Sp=73%) in women for predicting metabolic health. Values were 19.3kg/m2 (Se=58%; Sp=59%), 7.0kg/m2 (Se=61%; Sp=62%) and 0.49 (Se=62%; Sp=62%) in men; and 15.7kg/m2 (Se=58%; Sp=59%), 6.4kg/m2 (Se=61%; Sp=62%) and 0.35 (Se=62%; Sp=62%) in women for cardiovascular complications. Whatever the outcomes considered, the Youden indexes for BMI values were systematically below 25 kg/m2, except for cardiovascular complications in men, where the threshold for the best Se/Sp was 25.7 kg/m2. These cutoff values for FMI, MMI, and FM/MM could be of practical value for the clinical evaluation of a deficit in MM with or without excess of FM. They complement the classical concept of BMI in a more qualitative manner and extend the analysis of its impact on health outcomes to all BMI categories

  12. Determination of Cutoff Values for DEXA-Based Body Composition Measurements for Determining Metabolic and Cardiovascular Health.

    PubMed

    Lang, Pierre-Olivier; Trivalle, Christophe; Vogel, Thomas; Proust, Jacques; Papazyan, Jean-Pierre; Dramé, Moustapha

    2015-01-01

    The two components of the body weight (i.e., fat mass and muscle mass) appeared to be of high interest to consider in predicting metabolic health related risks. We aimed to determine cutoff values for fat mass index (FMI) and muscle mass index (MMI), FM/MM, and BMI for metabolic and cardiovascular health. This study was a cross-sectional analysis study conducted in a center of preventive medicine. It included 616 consecutive outpatients: mean age was 56.0±10.0 years (74.6% aged ≥50), and 61.4% were female. Fat and muscle mass were obtained with dual energy X-ray absorptiometry scan analyses. Metabolically unhealthy individuals were defined as people with biological features of dyslipidemia, hyperuricemia, diabetes, and/or hepatitis steatosis. Documented hypertension and/or atherosclerosis of at least one major artery defined individuals with cardiovascular complications. Receiver-operating characteristic curve analysis revealed that the cutoff values for MMI, FMI, and FM/MM were respectively 18.8kg/m(2) (sensitivity [Se]=58%; specificity [Sp]=59%), 5.5kg/m(2) (Se=61%; Sp=62%), and 0.31 (Se=62%; Sp=62%) in men; and 14.1kg/m(2) (Se=52%; Sp=54%), 5.5kg/m(2) (Se=65%; Sp=67%), 0.39 (Se=73%; Sp=73%) in women for predicting metabolic health. Values were 19.3kg/m(2) (Se=58%; Sp=59%), 7.0kg/m(2) (Se=61%; Sp=62%) and 0.49 (Se=62%; Sp=62%) in men; and 15.7kg/m(2) (Se=58%; Sp=59%), 6.4kg/m(2) (Se=61%; Sp=62%) and 0.35 (Se=62%; Sp=62%) in women for cardiovascular complications. Whatever the outcomes considered, the Youden indexes for BMI values were systematically below 25 kg/m(2), except for cardiovascular complications in men, where the threshold for the best Se/Sp was 25.7 kg/m(2). These cutoff values for FMI, MMI, and FM/MM could be of practical value for the clinical evaluation of a deficit in MM with or without excess of FM. They complement the classical concept of BMI in a more qualitative manner and extend the analysis of its impact on health outcomes to all BMI

  13. Would raising the total cholesterol diagnostic cut-off from 7.5 mmol/L to 9.3 mmol/L improve detection rate of patients with monogenic familial hypercholesterolaemia?

    PubMed Central

    Futema, M.; Kumari, M.; Boustred, C.; Kivimaki, M.; Humphries, S.E.

    2015-01-01

    A previous report suggested that 88% of individuals in the general population with total cholesterol (TC) > 9.3 mmol/L have familial hypercholesterolaemia (FH). We tested this hypothesis in a cohort of 4896 UK civil servants, mean (SD) age 44 (±6) years, using next generation sequencing to achieve a comprehensive genetic diagnosis. 25 (0.5%) participants (mean age 49.2 years) had baseline TC > 9.3 mmol/L, and overall we found an FH-causing mutation in the LDLR gene in seven (28%) subjects. The detection rate increased to 39% by excluding eight participants with triglyceride levels over 2.3 mmol/L, and reached 75% in those with TC > 10.4 mmol/L. By extrapolation, the detection rate would be ∼25% by including all participants with TC > 8.6 mmol/L (2.5 standard deviations from the mean). Based on the 1/500 FH frequency, 30% of all FH-cases in this cohort would be missed using the 9.3 mmol/L cut-off. Given that an overall detection rate of 25% is considered economically acceptable, these data suggest that a diagnostic TC cut-off of 8.6 mmol/L, rather than 9.3 mmol/L would be clinically useful for FH in the general population. PMID:25682026

  14. A Summary of the Lateral Cutoff Analysis and Results from Nasa's Farfield Investigation of No-Boom Thresholds

    NASA Technical Reports Server (NTRS)

    Cliatt, Larry J., II; Hill, Michael A.; Haering, Edward A., Jr.; Arnac, Sarah R.

    2015-01-01

    In support of the ongoing effort by the National Aeronautics and Space Administration (NASA) to bring supersonic commercial travel to the public, NASA, in partnership with other industry organizations, conducted a flight research experiment to analyze acoustic propagation at the lateral edge of the sonic boom carpet. The name of the effort was the Farfield Investigation of No-boom Thresholds (FaINT). The research from FaINT determined an appropriate metric for sonic boom waveforms in the transition and shadow zones called Perceived Sound Exposure Level, established a value of 65 dB as a limit for the acoustic lateral extent of a sonic boom's noise region, analyzed change in sonic boom levels near lateral cutoff, and compared between real sonic boom measurements and numerical predictions.

  15. Some consequences of the generalized uncertainty principle induced ultraviolet wave-vector cutoff in one-dimensional quantum mechanics

    NASA Astrophysics Data System (ADS)

    Sailer, K.; Péli, Z.; Nagy, S.

    2013-04-01

    A projection method is proposed to treat the one-dimensional Schrödinger equation for a single particle when the generalized uncertainty principle (GUP) generates an ultraviolet (UV) wave-vector cutoff. The existence of a unique coordinate representation called the naive one is derived from the one-parameter family of discrete coordinate representations. In this bandlimited quantum mechanics a continuous potential is reconstructed from discrete sampled values observed by means of a particle in maximally localized states. It is shown that bandlimitation modifies the speed of the center and the spreading time of a Gaussian wave packet moving in free space. Indication is found that GUP accompanied by bandlimitation may cause departures of the low-lying energy levels of a particle in a box from those in ordinary quantum mechanics to be much less suppressed than commonly thought when GUP without bandlimitation is at work.

  16. Epidemiologic cutoff values for triazole drugs in Cryptococcus gattii: correlation of molecular type and in vitro susceptibility.

    PubMed

    Lockhart, Shawn R; Iqbal, Naureen; Bolden, Carol B; DeBess, Emilio E; Marsden-Haug, Nicola; Worhle, Ron; Thakur, Rameshwari; Harris, Julie R

    2012-06-01

    Cryptococcus gattii causes infection in tropical and subtropical regions worldwide but has garnered increased attention since its 1999 emergence in North America. C. gattii can be divided into 4 molecular types that may represent cryptic species. Recent evidence has shown that azole antifungal MIC values differ among these molecular types. We tested a large collection of C. gattii isolates for susceptibility to 4 azole drugs. We found that isolates of molecular type VGII have the highest geometric mean (GM) fluconazole MIC values (8.6 μg/mL), while isolates of molecular type VGI have the lowest (1.7 μg/mL). For fluconazole, itraconazole, and voriconazole GM MIC values, VGI < VGIII < VGIV < VGII. The GM MIC values for posaconazole were similarly represented across molecular types, with the exception that VGII < VGIII and VGIV. We used the MIC values to establish preliminary epidemiologic cutoff values for each azole and molecular type of C. gattii.

  17. Psychometric properties and clinical cut-off scores of the Spanish version of the Social Anxiety Scale for Adolescents.

    PubMed

    Garcia-Lopez, Luis J; Inglés, Cándido J; García-Fernández, José M; Hidalgo, María D; Bermejo, Rosa; Puklek Levpušček, Melita

    2011-01-01

    This study examined the reliability and validity evidence drawn from the scores of the Spanish version of the Slovenian-developed Social Anxiety Scale for Adolescents (SASA; Puklek, 1997; Puklek & Vidmar, 2000) using a community sample (Study 1) and a clinical sample (Study 2). Confirmatory factor analysis in Study 1 replicated the 2-factor structure found by the original authors in a sample of Slovenian adolescents. Test-retest reliability was adequate. Furthermore, the SASA correlated significantly with other social anxiety scales, supporting concurrent validity evidence in Spanish adolescents. The results of Study 2 confirmed the correlations between the SASA and other social anxiety measures in a clinical sample. In addition, findings revealed that the SASA can effectively discriminate between adolescents with a clinical diagnosis of social anxiety disorder (SAD) and those without this disorder. Finally, cut-off scores for the SASA are provided for Spanish adolescents.

  18. Experimental differential cross sections, level densities, and spin cutoffs as a testing ground for nuclear reaction codes

    DOE PAGES

    Voinov, Alexander V.; Grimes, Steven M.; Brune, Carl R.; ...

    2013-11-08

    Proton double-differential cross sections from 59Co(α,p)62Ni, 57Fe(α,p)60Co, 56Fe(7Li,p)62Ni, and 55Mn(6Li,p)60Co reactions have been measured with 21-MeV α and 15-MeV lithium beams. Cross sections have been compared against calculations with the empire reaction code. Different input level density models have been tested. It was found that the Gilbert and Cameron [A. Gilbert and A. G. W. Cameron, Can. J. Phys. 43, 1446 (1965)] level density model is best to reproduce experimental data. Level densities and spin cutoff parameters for 62Ni and 60Co above the excitation energy range of discrete levels (in continuum) have been obtained with a Monte Carlo technique. Furthermore,more » excitation energy dependencies were found to be inconsistent with the Fermi-gas model.« less

  19. Italians do it worse. Montreal Cognitive Assessment (MoCA) optimal cut-off scores for people with probable Alzheimer's disease and with probable cognitive impairment.

    PubMed

    Bosco, Andrea; Spano, Giuseppina; Caffò, Alessandro O; Lopez, Antonella; Grattagliano, Ignazio; Saracino, Giuseppe; Pinto, Katia; Hoogeveen, Frans; Lancioni, Giulio E

    2017-02-02

    Montreal cognitive assessment (MoCA) is a test providing a brief screening for people with cognitive impairment due to aging or neurodegenerative syndromes. In Italy, as in the rest of the world, several validation studies of MoCA have been carried out. This study compared, for the first time in Italy, a sample of people with probable Alzheimer's Disease (AD) with healthy counterparts. The study also compared two community-dwelling groups of aged participants with and without probable cognitive impairment, as discriminated by two cut-off points of adjusted MMSE score. All the comparisons were carried out according to ROC statistics. Optimal cutoff for a diagnosis of probable AD was a MoCA score ≤14. Optimal cutoff for the discrimination of probable cognitive impairment was a MoCA score ≤17 (associated to MMSE cutoff of 23.8). Results confirm the substantial discrepancy in cut-off points existing between Italian and other international validation studies, showing that Italian performance on MoCA seems to be globally lower than that in other Countries. Characteristics of population might explain these results.

  20. The impact of an underground cut-off wall on nutrient dynamics in groundwater in the lower Wang River watershed, China.

    PubMed

    Kang, Pingping; Xu, Shiguo

    2017-03-01

    Underground cut-off walls in coastal regions are mainly used to prevent saltwater intrusion, but their impact on nutrient dynamics in groundwater is not clear. In this study, a combined analysis of multiple isotopes ([Formula: see text]) and nitrogen and phosphorus concentrations is used in order to assess the impact of the underground cut-off walls on the nutrient dynamics in groundwater in the lower Wang River watershed, China. Compared with the nitrogen and phosphorus concentrations in groundwater downstream of the underground cut-off walls, high [Formula: see text] and total dissolved nitrogen concentrations and similar concentration levels of [Formula: see text] and total dissolved phosphorus are found in groundwater upstream of the underground cut-off walls. The isotopic data indicated the probable occurrence of denitrification and nitrification processes in groundwater upstream, whereas the fingerprint of these processes was not shown in groundwater downstream. The management of fertilizer application is critical to control nitrogen concentrations in groundwater restricted by the underground cut-off walls.

  1. A cutoff point for arterial stiffness using the cardio-ankle vascular index based on carotid arteriosclerosis.

    PubMed

    Hu, Huaqing; Cui, Huan; Han, Weixing; Ye, Liangping; Qiu, Wenting; Yang, Hui; Zhang, Chuanwu; Guo, Xiaojuan; Mao, Guangyun

    2013-04-01

    The cardio-ankle vascular index (CAVI) has been widely accepted as a good indicator of arteriosclerosis. However, the lack of a reliable diagnostic criterion for CAVI hampers the proper clinical screening for arteriosclerosis using CAVI and impedes the prompt treatment of cardiovascular disease (CVD). There is an urgent need to determine a criterion for CAVI in arteriosclerosis prevention. We conducted a cross-sectional study to determine this criterion based on receiver operating characteristic (ROC) analyses in a Chinese population consisting of 328 participants. CAVI was measured in duplicate, and carotid ultrasound detection was performed in a quiet environment by well-trained physicians. After multivariate adjustment, CAVI was positively associated with the risk of carotid arteriosclerosis. Compared with participants in the lowest tertile of CAVI (5.15-7.40), those in the medium (7.41-8.65) and highest (8.66-13.60) tertiles had odds ratios (95% confidence interval) of 2.2 (1.0, 4.9) and 4.4 (1.5, 13.3), respectively, for developing carotid arteriosclerosis (P trend=0.007). The areas under the ROC curve (AUC) of the male, female and pooled populations were 0.789, 0.897 and 0.856, respectively. The cutoff point of CAVI≥8.0 resulted in the largest sensitivity and specificity. Furthermore, CAVI and age acted synergistically to increase the risk of carotid arteriosclerosis. CAVI≥8.0 may be an optimal cutoff point for carotid arteriosclerosis prediction. The older population with higher CAVI scores had a higher risk of carotid arteriosclerosis. Additional large prospective studies are needed to confirm our findings.

  2. Variation of the first cut-off frequency of the Earth-ionosphere waveguide observed by DEMETER

    NASA Astrophysics Data System (ADS)

    Toledo-Redondo, S.; Parrot, M.; Salinas, A.

    2012-04-01

    More than four years of VLF electric field data recorded by DEMETER have been analyzed, in order to monitor the first cut-off frequency (QTM1) of the Earth-ionosphere waveguide, at around 1.6-1.8 kHz. Since losses in a waveguide are maximized right at the cut-off frequency, DEMETER (˜700 km orbit) can detect the minimum of energy of the leaking fields coming from the waveguide. This measurement permits to draw a global map of its value (f1), which is directly related to the effective height of the ionosphere (h) by the relation f1 = c/2h (c is the speed of light). It enables the remote sensing of the D region, which is one of the less known layers of the ionosphere, because it is too low for satellites to orbit inside it and too high for balloons to reach it. The effective height depends mainly on the electron density (Ne) and neutral density (Nn) profiles, which determine the plasma frequency and the electron mobility. The effective height shifts downward 5-10 km in southern warm season in the South Pacific Ocean. Another effect is observed in the Indian and Atlantic Oceans; the effective height decreases its value twice a year, in the area of roughly ±15° from the geomagnetic equator. The main causes for the changes on the effective reflection height are the solar radiation and the thunderstorm activity. However, the observed shifts are more prominent over the oceans, and a possible explanation for this difference could be attributed to i) less polluted conditions above the oceans (aerosols change the atmospheric conductivity and then the global atmospheric electric circuit), ii) the effect of the current associated to the thunderclouds on the bottom of the ionosphere because thunderstorms are much more numerous above land, or iii) ionization by elves because their occurrence is larger above oceans.

  3. A new perspective of the climatological features of upper-level cut-off lows in the Southern Hemisphere

    NASA Astrophysics Data System (ADS)

    Pinheiro, Henri Rossi; Hodges, Kevin Ivan; Gan, Manoel Alonso; Ferreira, Nelson Jesuz

    2017-01-01

    This study presents a detailed view of the seasonal variability of upper-level cut-off lows (COLs) in the Southern Hemisphere. The COLs are identified and tracked using data from a 36-year period of the European Centre for Medium Range Weather Forecast reanalysis (ERA-Interim). The objective identification of the COLs uses a new approach, which is based on 300 hPa relative vorticity minima, and three restrictive criteria of the presence of a cold-core, stratospheric potential vorticity intrusion, and cut-off cyclonic circulation. The highest COL activity is in agreement with previous studies, located near three main continental areas (Australia, South America, and Africa), with maximum frequencies usually observed in the austral autumn. The COL mean intensity values show a marked seasonal and spatial variation, with maximum (minimum) values during the austral winter (summer), a unique feature that has not been observed previously in studies based on the geopotential. The link between intensity and lysis is examined, and finds that weaker systems are more susceptible to lysis in the vicinity of the Andes Cordillera, associated with the topographic Rossby wave. Lysis and genesis regions are close to each other, confirming that COLs are quasi-stationary systems. Also, COLs tend to move eastward and are faster over the higher latitudes. The mean growth/decay rates coincide with the major genesis and lysis density regions, such as the significant decay values across the Andes all year. As a consequence of using vorticity for the tracking method a longer lifetime of COLs is detected than in other studies, but this does not affect the total frequency of occurrence. Comparisons with other studies suggest that the differences in seasonality are due to uncertainties in the reanalyses and the methods used to identify COLs.

  4. Evaluation of a proper cutoff value on quantitative dual-energy perfusion CT for the assessment of acute pulmonary thromboembolism.

    PubMed

    Kunihiro, Yoshie; Okada, Munemasa; Matsunaga, Naofumi

    2017-01-01

    Background The cutoff value for assessing the severity of acute pulmonary thromboembolism (PTE) using relative volumetric evaluations of dual-energy perfusion computed tomography (DEpCT) is unclear. Purpose To determine the proper cutoff value for determining the severity of PTE using DEpCT volumetry. Material and Methods A total of 185 patients with venous thromboembolism were included in this study, of whom 61 were diagnosed with acute PTE. DEpCT images were three-dimensionally reconstructed at the following attenuation ranges: 1-2 HU (V2), 1-10 HU (V10), and 1-120 HU (V120). The ratios of low perfusion areas associated with each threshold range per V120 were also calculated, and the relative ratios were expressed as %V2 to %V10. These values were compared with factors indicating the severity of PTE, including the pulmonary arterial pressure, heart rate, CT angiographic obstruction index (CTOI), and right/left ventricular diameter ratio (RV/LV). Results The area under the curve (AUC) of %V2 was highest (0.783) among these values (95% confidence interval, 0.710-0.856) based on the presence of IPCs. The %V2 showed moderate correlations with CTOI (r = 0.36, P = 0.005) and RV/LV (r = 0.36, P = 0.004) in the patients with acute PTE. Conclusion Volumetric evaluations of DEpCT images using the lowest attenuation threshold range (1-2 HU) exhibit the best correlation with factors suggesting the severity of acute PTE.

  5. Use of the Azimuth Wavelength Cut-Off to Retrieve the Sea Surface Wind Speed from Sentinel 1 and COSMO-SkyMed SAR Data

    NASA Astrophysics Data System (ADS)

    Grieco, G.; Nirchio, F.; Montuori, A.; Migliaccio, M.; Lin, W.; Portabella, M.

    2016-08-01

    The dependency of the azimuth wavelength cut-off on the wind speed has been studied through a dataset of Sentinel-1 multi look SAR images co-located with wind speed measurements, significant wave height and mean wave direction from ECMWF operational output.A Geophysical Model Function (GMF) has been fitted and a retrieval exercise has been done comparing the results to a set of independent wind speed scatterometer measurements of the Chinese mission HY-2A. The preliminary results show that the dependency of the azimuth cut-off on the wind speed is linear only for fully developed sea states and that the agreement between the retrieved values and the measurements is good especially for high wind speed.A similar approach has been used to assess the dependency of the azimuth cut-off also for X-band COSMO-SkyMed data. The dataset is still incomplete but the preliminary results show a similar trend.

  6. Cut-Offs and Response Criteria for the Hospital Universitario La Princesa Index (HUPI) and Their Comparison to Widely-Used Indices of Disease Activity in Rheumatoid Arthritis

    PubMed Central

    Castrejón, Isabel; Ortiz, Ana M.; Toledano, Esther; Castañeda, Santos; García-Vadillo, Alberto; Carmona, Loreto

    2016-01-01

    Objective To estimate cut-off points and to establish response criteria for the Hospital Universitario La Princesa Index (HUPI) in patients with chronic polyarthritis. Methods Two cohorts, one of early arthritis (Princesa Early Arthritis Register Longitudinal [PEARL] study) and other of long-term rheumatoid arthritis (Estudio de la Morbilidad y Expresión Clínica de la Artritis Reumatoide [EMECAR]) including altogether 1200 patients were used to determine cut-off values for remission, and for low, moderate and high activity through receiver operating curve (ROC) analysis. The areas under ROC (AUC) were compared to those of validated indexes (SDAI, CDAI, DAS28). ROC analysis was also applied to establish minimal and relevant clinical improvement for HUPI. Results The best cut-off points for HUPI are 2, 5 and 9, classifying RA activity as remission if ≤2, low disease activity if >2 and ≤5), moderate if >5 and <9 and high if ≥9. HUPI’s AUC to discriminate between low-moderate activity was 0.909 and between moderate-high activity 0.887. DAS28’s AUCs were 0.887 and 0.846, respectively; both indices had higher accuracy than SDAI (AUCs: 0.832 and 0.756) and CDAI (AUCs: 0.789 and 0.728). HUPI discriminates remission better than DAS28-ESR in early arthritis, but similarly to SDAI. The HUPI cut-off for minimal clinical improvement was established at 2 and for relevant clinical improvement at 4. Response criteria were established based on these cut-off values. Conclusions The cut-offs proposed for HUPI perform adequately in patients with either early or long term arthritis. PMID:27603313

  7. Predictive capacity of a non-radioisotopic local lymph node assay using flow cytometry, LLNA:BrdU-FCM: Comparison of a cutoff approach and inferential statistics.

    PubMed

    Kim, Da-Eun; Yang, Hyeri; Jang, Won-Hee; Jung, Kyoung-Mi; Park, Miyoung; Choi, Jin Kyu; Jung, Mi-Sook; Jeon, Eun-Young; Heo, Yong; Yeo, Kyung-Wook; Jo, Ji-Hoon; Park, Jung Eun; Sohn, Soo Jung; Kim, Tae Sung; Ahn, Il Young; Jeong, Tae-Cheon; Lim, Kyung-Min; Bae, SeungJin

    2016-01-01

    In order for a novel test method to be applied for regulatory purposes, its reliability and relevance, i.e., reproducibility and predictive capacity, must be demonstrated. Here, we examine the predictive capacity of a novel non-radioisotopic local lymph node assay, LLNA:BrdU-FCM (5-bromo-2'-deoxyuridine-flow cytometry), with a cutoff approach and inferential statistics as a prediction model. 22 reference substances in OECD TG429 were tested with a concurrent positive control, hexylcinnamaldehyde 25%(PC), and the stimulation index (SI) representing the fold increase in lymph node cells over the vehicle control was obtained. The optimal cutoff SI (2.7≤cutoff <3.5), with respect to predictive capacity, was obtained by a receiver operating characteristic curve, which produced 90.9% accuracy for the 22 substances. To address the inter-test variability in responsiveness, SI values standardized with PC were employed to obtain the optimal percentage cutoff (42.6≤cutoff <57.3% of PC), which produced 86.4% accuracy. A test substance may be diagnosed as a sensitizer if a statistically significant increase in SI is elicited. The parametric one-sided t-test and non-parametric Wilcoxon rank-sum test produced 77.3% accuracy. Similarly, a test substance could be defined as a sensitizer if the SI means of the vehicle control, and of the low, middle, and high concentrations were statistically significantly different, which was tested using ANOVA or Kruskal-Wallis, with post hoc analysis, Dunnett, or DSCF (Dwass-Steel-Critchlow-Fligner), respectively, depending on the equal variance test, producing 81.8% accuracy. The absolute SI-based cutoff approach produced the best predictive capacity, however the discordant decisions between prediction models need to be examined further.

  8. Comparison of Interferon-γ Release Assay to Two Cut-Off Points of Tuberculin Skin Test to Detect Latent Mycobacterium tuberculosis Infection in Primary Health Care Workers

    PubMed Central

    de Souza, Fernanda Mattos; do Prado, Thiago Nascimento; Pinheiro, Jair dos Santos; Peres, Renata Lyrio; Lacerda, Thamy Carvalho; Loureiro, Rafaela Borge; Carvalho, Jose Américo; Fregona, Geisa; Dias, Elias Santos; Cosme, Lorrayne Beliqui; Rodrigues, Rodrigo Ribeiro; Riley, Lee Wood; Maciel, Ethel Leonor Noia

    2014-01-01

    Background An interferon-γ release assay, QuantiFERON-TB (QFT) test, has been introduced an alternative test for the diagnosis of latent Mycobacterium tuberculosis infection (LTBI). Here, we compared the performance of QFT with tuberculin skin test (TST) measured at two different cut-off points among primary health care work (HCW) in Brazil. Methods A cross-sectional study was carried out among HCWs in four Brazilian cities with a known history of high incidence of TB. Results of the QFT were compared to TST results based on both ≥5 mm and ≥10 mm as cut-off points. Results We enrolled 632 HCWs. When the cut-off value of ≥10 mm was used, agreement between QFT and TST was 69% (k = 0.31), and when the cut-off of ≥5 mm was chosen, the agreement was 57% (k = 0.22). We investigated possible factors of discordance of TST vs QFT. Compared to the TST−/QFT− group, risk factors for discordance in the TST+/QFT− group with TST cut-off of ≥5 mm included age between 41–45 years [OR = 2.70; CI 95%: 1.32–5.51] and 46–64 years [OR = 2.04; CI 95%: 1.05–3.93], BCG scar [OR = 2.72; CI 95%: 1.40–5.25], and having worked only in primary health care [OR = 2.30; CI 95%: 1.09–4.86]. On the other hand, for the cut-off of ≥10 mm, BCG scar [OR = 2.26; CI 95%: 1.03–4.91], being a household contact of a TB patient [OR = 1.72; CI 95%: 1.01–2.92] and having had a previous TST [OR = 1.66; CI 95%: 1.05–2.62], were significantly associated with the TST+/QFT− group. No statistically significant associations were found among the TST−/QFT+ discordant group with either TST cut-off value. Conclusions Although we identified BCG vaccination to contribute to the discordance at both TST cut-off measures, the current Brazilian recommendation for the initiation of LTBI treatment, based on information gathered from medical history, TST, chest radiograph and physical examination, should not be changed. PMID:25137040

  9. N-tuple topological/geometric cutoffs for 3D N-linear algebraic molecular codifications: variability, linear independence and QSAR analysis.

    PubMed

    García-Jacas, C R; Marrero-Ponce, Y; Barigye, S J; Hernández-Ortega, T; Cabrera-Leyva, L; Fernández-Castillo, A

    2016-12-01

    Novel N-tuple topological/geometric cutoffs to consider specific inter-atomic relations in the QuBiLS-MIDAS framework are introduced in this manuscript. These molecular cutoffs permit the taking into account of relations between more than two atoms by using (dis-)similarity multi-metrics and the concepts related with topological and Euclidean-geometric distances. To this end, the kth two-, three- and four-tuple topological and geometric neighbourhood quotient (NQ) total (or local-fragment) spatial-(dis)similarity matrices are defined, to represent 3D information corresponding to the relations between two, three and four atoms of the molecular structures that satisfy certain cutoff criteria. First, an analysis of a diverse chemical space for the most common values of topological/Euclidean-geometric distances, bond/dihedral angles, triangle/quadrilateral perimeters, triangle area and volume was performed in order to determine the intervals to take into account in the cutoff procedures. A variability analysis based on Shannon's entropy reveals that better distribution patterns are attained with the descriptors based on the cutoffs proposed (QuBiLS-MIDAS NQ-MDs) with regard to the results obtained when all inter-atomic relations are considered (QuBiLS-MIDAS KA-MDs - 'Keep All'). A principal component analysis shows that the novel molecular cutoffs codify chemical information captured by the respective QuBiLS-MIDAS KA-MDs, as well as information not captured by the latter. Lastly, a QSAR study to obtain deeper knowledge of the contribution of the proposed methods was carried out, using four molecular datasets (steroids (STER), angiotensin converting enzyme (ACE), thermolysin inhibitors (THER) and thrombin inhibitors (THR)) widely used as benchmarks in the evaluation of several methodologies. One to four variable QSAR models based on multiple linear regression were developed for each compound dataset following the original division into training and test sets. The

  10. Blood Lactate Levels Cutoff and Mortality Prediction in Sepsis—Time for a Reappraisal? a Retrospective Cohort Study

    PubMed Central

    Filho, Roberto Rabello; Rocha, Leonardo Lima; Corrêa, Thiago Domingos; Pessoa, Camila Menezes Souza; Colombo, Giancarlo; Assuncao, Murillo Santucci Cesar

    2016-01-01

    Abstract The objective of this study was to identify the initial value of blood lactate that best correlates with 28-day mortality in resuscitated septic shock patients. This was a retrospective cohort study including 443 patients admitted to an intensive care unit (ICU) with severe sepsis or septic shock from the emergency department. A receiver-operating characteristic (ROC) curve was drawn to obtain the best cutoff value for initial blood lactate associated with 28-day mortality. Patients were then dichotomized according to the chosen lactate cutoff, and sensitivity, specificity, and positive and negative predictive values were calculated. Baseline blood lactate level more than 2.5 mmol/L showed the largest area under the ROC curve to predict 28-day mortality (ROC area, 0.70; 95% confidence interval [CI], 0.62–0.79), with sensitivity, specificity, and negative predictive value of 67.4%, 61.7%, and 94.2%, respectively. Mortality at 28 days was 16.9% (31/183) in patients with initial lactate more than 2.5 mmol/L and 5.8% (15/260) in patients with initial lactate at most 2.5 mmol/L (relative risk, 2.93; 95% CI, 1.63–5.28; P < 0.001). Initial blood lactate levels more than 2.5 mmol/L (hazard ratio [HR], 2.86; 95% CI, 1.53–5.33; P = 0.001) and Sepsis-related Organ Failure Assessment score at ICU admission (HR, 1.18; 95% CI, 1.09–1.27; P < 0.001) were associated with increased 28-day mortality in the adjusted Cox regression. In this retrospective cohort study, a lactate level more than 2.5 mmol/L was the best threshold to predict 28-day mortality among severe sepsis and septic shock patients. Further prospective studies should address the impact on morbidity and mortality of this threshold as a trigger to resuscitation in this population of critically ill patients. PMID:27380535

  11. Evaluation of total body weight and body mass index cut-offs for increased cefazolin dose for surgical prophylaxis.

    PubMed

    Hites, Maya; Deprez, Guillaume; Wolff, Fleur; Ickx, Brigitte; Verleije, Anita; Closset, Jean; Loi, Patrizia; Prévost, Jessica; Taccone, Fabio S; Racapé, Judith; Cotton, Frédéric; Jacobs, Frédérique

    2016-12-01

    French and American guidelines recommend increased dosage regimens of cefazolin (CFZ) for surgical prophylaxis in patients with a body mass index (BMI) ≥ 35 kg/m(2) or with a total body weight (TBW) ≥ 120 kg. The objective of this study was to evaluate the accuracy of these cut-offs in identifying patients who require CFZ dose adjustment. A pharmacokinetic study was conducted in patients of varying TBW and BMI who received 2 g of CFZ intravenously for prophylaxis prior to digestive surgery. Adequacy of therapy, defined as a serum concentration of unbound CFZ (fCFZ) ≥ 4 mg/L, was evaluated 180 min (T180) and 240 min (T240) after the start of CFZ infusion. Possible factors associated with insufficient fCFZ levels were also assessed. A P-value of <0.05 was considered statistically significant. A total of 63 patients were included in the study, categorised according to BMI (<35 kg/m(2), 20 patients; and ≥35 kg/m(2), 43 patients) and TBW (<120 kg, 41 patients; and ≥120 kg, 22 patients). All patients had adequate drug levels at T180 but only 40/63 patients (63%) had adequate levels at T240. At T240, therapy was adequate in 15/20 patients (75%) and 25/43 patients (58%) with BMI <35 kg/m(2) and ≥35 kg/m(2), respectively (P = 0.20), and in 28/41 patients (68%) and 12/22 patients (55%) with TBW <120 kg and ≥120 kg, respectively (P = 0.28). No factor associated with insufficient fCFZ was identified. In conclusion, current BMI and TBW cut-offs are poor indicators of which patients could benefit from increased CFZ dosage regimens.

  12. Masking Misfit in Confirmatory Factor Analysis by Increasing Unique Variances: A Cautionary Note on the Usefulness of Cutoff Values of Fit Indices

    ERIC Educational Resources Information Center

    Heene, Moritz; Hilbert, Sven; Draxler, Clemens; Ziegler, Matthias; Buhner, Markus

    2011-01-01

    Fit indices are widely used in order to test the model fit for structural equation models. In a highly influential study, Hu and Bentler (1999) showed that certain cutoff values for these indices could be derived, which, over time, has led to the reification of these suggested thresholds as "golden rules" for establishing the fit or other aspects…

  13. Cosmological properties and reconstruction of scalar field models of the Holographic Dark Energy model with Granda-Oliveros cut-off in Kaluza-Klein cosmology

    NASA Astrophysics Data System (ADS)

    Pasqua, Antonio; Chattopadhyay, Surajit; Assaf, Khudhair A.; Salako, Ines G.

    2016-06-01

    In this paper, we study the properties of the Holographic Dark Energy (HDE) model in the context of Kaluza-Klein (KK) cosmology with infrared cut-off given by the recently proposed by Granda-Oliveros cut-off, which contains a term proportional to the time derivative of the Hubble parameter and one proportional to the Hubble parameter squared. Moreover, this cut-off is characterized by two free parameters which are the proportional constants of the two terms of the cut-off. We derive the expression of the Equation of State (EoS) parameter ωD and of the deceleration parameter q for both non-interacting and interacting Dark Sectors and in the limiting case of a flat Dark Dominated Universe. Moreover, we study the squared speed of the sound vs2 and the statefinder diagnostic \\{r,s\\} in order to understand the cosmological properties of the model considered. We also develop a correspondence between the model considered and three scalar field models: the tachyon, the k-essence and the quintessence ones.

  14. Derivation and Cross-Validation of Cutoff Scores for Patients With Schizophrenia Spectrum Disorders on WAIS-IV Digit Span-Based Performance Validity Measures.

    PubMed

    Glassmire, David M; Toofanian Ross, Parnian; Kinney, Dominique I; Nitch, Stephen R

    2016-06-01

    Two studies were conducted to identify and cross-validate cutoff scores on the Wechsler Adult Intelligence Scale-Fourth Edition Digit Span-based embedded performance validity (PV) measures for individuals with schizophrenia spectrum disorders. In Study 1, normative scores were identified on Digit Span-embedded PV measures among a sample of patients (n = 84) with schizophrenia spectrum diagnoses who had no known incentive to perform poorly and who put forth valid effort on external PV tests. Previously identified cutoff scores resulted in unacceptable false positive rates and lower cutoff scores were adopted to maintain specificity levels ≥90%. In Study 2, the revised cutoff scores were cross-validated within a sample of schizophrenia spectrum patients (n = 96) committed as incompetent to stand trial. Performance on Digit Span PV measures was significantly related to Full Scale IQ in both studies, indicating the need to consider the intellectual functioning of examinees with psychotic spectrum disorders when interpreting scores on Digit Span PV measures.

  15. Enhanced Narrow-band, Coherent Emission from a Current Source Immersed in Cut-off of a Plasma-like Medium

    NASA Astrophysics Data System (ADS)

    Hur, Min Sup; Ersfeld, Bernhard; Noble, Adam; Suk, Hyyong; Jaroszynski, Dino

    2016-10-01

    In plasma-like media sharing a similar dispersion relation, there exists a cut-off frequency to make the wave number zero. This particular situation has been understood classically in a way that the radiation impedance becomes infinite, resulting in a total reflection of an incident wave. However, in this framework of understanding the cut-off, a pure current source immersed in the cut-off region leads to infinite radiation power from Ohm's law. This is obviously unphysical and requires a different approach to address the problem. In this presentation, we show that by solving the driven time-dependent Schrödinger equation, the radiation at the cut-off frequency can be selectively enhanced by several times the pure vacuum-emission. Important question here is whether such current sources are available in practical systems. We find that quasi-current sources are actually ubiquitous as long as the conversion efficiency from the current driver to the radiation emission is low. We demonstrate two such cases by PIC simulations; THz radiation from a plasma driven by colliding laser pulses, and THz from two-color lasers enclosed by a tapered waveguide. We also discuss the previous experimental results in terms of this enhanced emission concept.

  16. Optimal Elasticity cut-off value for discriminating Healthy to Pathological Fibrotic patients employing Fuzzy C-Means automatic segmentation in Liver Shear Wave Elastography images

    NASA Astrophysics Data System (ADS)

    Gatos, Ilias; Tsantis, Stavros; Skouroliakou, Aikaterini; Theotokas, Ioannis; Zoumpoulis, Pavlos S.; Kagadis, George C.

    2015-09-01

    The aim of the present study is to determine an optimal elasticity cut-off value for discriminating Healthy from Pathological fibrotic patients by means of Fuzzy C-Means automatic segmentation and maximum participation cluster mean value employment in Shear Wave Elastography (SWE) images. The clinical dataset comprised 32 subjects (16 Healthy and 16 histological or Fibroscan verified Chronic Liver Disease). An experienced Radiologist performed SWE measurement placing a region of interest (ROI) on each subject's right liver lobe providing a SWE image for each patient. Subsequently Fuzzy C-Means clustering was performed on every SWE image utilizing 5 clusters. Mean Stiffness value and pixels number of each cluster were calculated. The mean stiffness value feature of the cluster with maximum pixels number was then fed as input for ROC analysis. The selected Mean Stiffness value feature an Area Under the Curve (AUC) of 0.8633 with Optimum Cut-off value of 7.5 kPa with sensitivity and specificity values of 0.8438 and 0.875 and balanced accuracy of 0.8594. Examiner's classification measurements exhibited sensitivity, specificity and balanced accuracy value of 0.8125 with 7.1 kPa cutoff value. A new promising automatic algorithm was implemented with more objective criteria of defining optimum elasticity cut-off values for discriminating fibrosis stages for SWE. More subjects are needed in order to define if this algorithm is an objective tool to outperform manual ROI selection.

  17. Metabolic Thresholds and Validated Accelerometer Cutoff Points for the Actigraph GT1M in Young Children Based on Measurements of Locomotion and Play Activities

    ERIC Educational Resources Information Center

    Jimmy, Gerda; Dossegger, Alain; Seiler, Roland; Mader, Urs

    2012-01-01

    The purpose of the current study was to determine metabolic thresholds and subsequent activity intensity cutoff points for the ActiGraph GT1M with various epochs spanning from 5 to 60 sec in young children. Twenty-two children, aged 4 to 9 years, performed 10 different activities including locomotion and play activities. Energy expenditure was…

  18. On a holographic dark energy model with a Nojiri-Odintsov cut-off in general relativity

    NASA Astrophysics Data System (ADS)

    Khurshudyan, Martiros

    2016-07-01

    In this paper we consider the models of the accelerated expanding large scale universe (according to general relativity) containing a generalized holographic dark energy with a Nojiri-Odintsov cut-off. The second component of the darkness is assumed to be the pressureless cold dark matter according to observed symmetries of the large scale universe. Moreover, we assume specific forms of the interaction between these two components and besides the cosmographic analysis, we discuss appropriate results from Om and Om3 analysis and organize a closer look to the models via the statefinder hierarchy analysis, too. In this way we study mainly impact of the interaction on the dynamics of the background of our universe (within specific forms of interaction). To complete the cosmographic analysis, the present day values of the statefinder parameters (r,s) and (ω^'_{de}, ω_{de}) has been estimated for all cases and the validity of the generalized second law of thermodynamics is demonstrated. Our study showed that theoretical results from considered phenomenological models are consistent with the available observational data and symmetries.

  19. Optimal Cut-Off Value of the Superior Articular Process Area as a Morphological Parameter to Predict Lumbar Foraminal Stenosis

    PubMed Central

    Lim, Tae-Ha; Choi, Soo Il; Cho, Hyung Rae; Kang, Keum Nae; Rhyu, Chang Joon; Chae, Eun Young; Lim, Young Su; Lee, Yongsoo

    2017-01-01

    Background. We devised a new morphological parameter called the superior articular process area (SAPA) to evaluate the connection between lumbar foraminal stenosis (LFS) and the superior articular process. Objective. We hypothesized that the SAPA is an important morphologic parameter in the diagnosis of LFS. Methods. All patients over 60 years of age were included. Data regarding the SAPA were collected from 137 patients with LFS. A total of 167 control subjects underwent lumbar magnetic resonance imaging (MRI) as part of a routine medical examination. We analyzed the cross-sectional area of the bone margin of the superior articular process at the level of L4-L5 facet joint in the axial plane. Results. The average SAPA was 96.3 ± 13.6 mm2 in the control group and 128.1 ± 17.2 mm2 in the LFS group. The LFS group was found to have significantly higher levels of SAPA (p < 0.001) in comparison to the control group. In the LFS group, the optimal cut-off value was 112.1 mm2, with 84.4% sensitivity, 83.9% specificity, and AUC of 0.94 (95% CI: 0.91–0.96). Conclusions. Higher SAPA values were associated with a higher possibility of LFS. These results are important in the evaluation of patients with LFS. PMID:28163566

  20. Atmospheric secondary charged cosmic radiation at a place of 11.5 GV geomagnetic cut-off

    NASA Astrophysics Data System (ADS)

    Azcarate, I. N.

    2002-04-01

    An experiment performed with a balloon-borne plastic scintillator is described. The detector system was transported by a stratospheric balloon, that was launched from Reconquista, province of Santa Fe, Argentina, on 24 February 1992. The geomagnetic cut-off of the site was 11.5 GV. The energy-loss spectra of both the atmospheric gamma radiation ( for E^γ>= 4.15 MeV) and the charged component of the secondary cosmic radiation were alternatively measured at different altitudes, during the ascent of the balloon, and at ceiling altitude. The author analyzed the atmospheric gamma-ray spectrum in a previous paper ( Azcárate, 2000). It was necessary to perform the computation of the response of the detector to the charged radiation in order to explain , at least qualitatively, the energy-loss spectrum in the detector produced by this type of radiation. It is argued that at ceiling altitude the observed feature in the spectrum is produced mainly by relativistic muons falling horizontally upon the detector. The growth curve for the counting rate below this feature and the intensity of relativistic μ-mesons were also obtained. References : Azcárate, I.N., Revista Mexicana de Astronomía y Astrofísica, 36, 81, 2000.

  1. The acid phosphatase test two minute cut-off: an insufficient time to detect some semen stains.

    PubMed

    Redhead, Paul; Brown, Melanie K

    2013-06-01

    The ability to detect semen in sexual offence cases is a crucial first step to locating stains which may be suitable for DNA profiling. Since the development of the acid phosphatase test in the late 1950s by Stuart S. Kind, the process undertaken to perform the test has gone largely unchanged. The method currently accepted by operational forensic science laboratories allows 2 min for a reaction to be obtained, and until relatively recently, this has not been challenged. In this research, samples of semen were obtained from three donors and a range of dilutions for each sample were prepared. Each dilution was subjected to acid phosphatase testing using both direct testing and the 'press test' method. The results showed that semen could be detected in excess of 15 min in dilutions up to 1 in 400 using the press test method and in dilutions up to 1 in 1000 using the direct method. Of further significance was the observation that using the press test method, the two minute cut-off was insufficient to detect the majority of stains and in some cases, semen stains as strong as 1 in 20 dilutions. This research provides compelling evidence for protocols currently utilised in forensic practice to be reviewed in order that forensic scientists do not overlook potential evidential material that may prove suitable for body fluid identification such as DNA STR profiling.

  2. RemoveYoung: A tool for the removal of the young stellar component in galaxies within an adjustable age cutoff

    NASA Astrophysics Data System (ADS)

    Gomes, J. M.; Papaderos, P.

    2016-10-01

    The optical morphology of galaxies holds the cumulative record of their assembly history, and techniques for its quantitative characterization offer a promising avenue toward understanding galaxy formation and evolution. However, the morphology of star-forming galaxies is generally dictated by the youngest stellar component, which can readily overshine faint structural/morphological features in the older underlying stellar background (e.g., relics from recent minor mergers) that could hold important insights into the galaxy build-up process. Stripping off galaxy images from the emission from stellar populations younger than an adjustable age cutoff tcut can therefore provide a valuable tool in extragalactic research. RemoveYoung (), a publicly available tool that is presented here, exploits the combined power of integral field spectroscopy (IFS) and spectral population synthesis (SPS) toward this goal. Two-dimensional (2D) post-processing of SPS models to IFS data cubes with permits computation of the spectral energy, surface brightness, and stellar surface density distribution of stellar populations older than a user-defined tcut. This suggests a variety of applications of star-forming galaxies, such as interacting or merging galaxy pairs and lower mass starburst galaxies near and far; these include blue compact and tidal dwarf galaxies.

  3. Determining Cutoff Point of Ensemble Trees Based on Sample Size in Predicting Clinical Dose with DNA Microarray Data

    PubMed Central

    Karabulut, Erdem; Alpar, Celal Reha

    2016-01-01

    Background/Aim. Evaluating the success of dose prediction based on genetic or clinical data has substantially advanced recently. The aim of this study is to predict various clinical dose values from DNA gene expression datasets using data mining techniques. Materials and Methods. Eleven real gene expression datasets containing dose values were included. First, important genes for dose prediction were selected using iterative sure independence screening. Then, the performances of regression trees (RTs), support vector regression (SVR), RT bagging, SVR bagging, and RT boosting were examined. Results. The results demonstrated that a regression-based feature selection method substantially reduced the number of irrelevant genes from raw datasets. Overall, the best prediction performance in nine of 11 datasets was achieved using SVR; the second most accurate performance was provided using a gradient-boosting machine (GBM). Conclusion. Analysis of various dose values based on microarray gene expression data identified common genes found in our study and the referenced studies. According to our findings, SVR and GBM can be good predictors of dose-gene datasets. Another result of the study was to identify the sample size of n = 25 as a cutoff point for RT bagging to outperform a single RT. PMID:28096893

  4. The Cutoff protein regulates piRNA cluster expression and piRNA production in the Drosophila germline

    PubMed Central

    Pane, Attilio; Jiang, Peng; Zhao, Dorothy Yanling; Singh, Mona; Schüpbach, Trudi

    2011-01-01

    In a broad range of organisms, Piwi-interacting RNAs (piRNAs) have emerged as core components of a surveillance system that protects the genome by silencing transposable and repetitive elements. A vast proportion of piRNAs is produced from discrete genomic loci, termed piRNA clusters, which are generally embedded in heterochromatic regions. The molecular mechanisms and the factors that govern their expression are largely unknown. Here, we show that Cutoff (Cuff), a Drosophila protein related to the yeast transcription termination factor Rai1, is essential for piRNA production in germline tissues. Cuff accumulates at centromeric/pericentromeric positions in germ-cell nuclei and strongly colocalizes with the major heterochromatic domains. Remarkably, we show that Cuff is enriched at the dual-strand piRNA cluster 1/42AB and is likely to be involved in regulation of transcript levels of similar loci dispersed in the genome. Consistent with this observation, Cuff physically interacts with the Heterochromatin Protein 1 (HP1) variant Rhino (Rhi). Our results unveil a link between Cuff activity, heterochromatin assembly and piRNA cluster expression, which is critical for stem-cell and germ-cell development in Drosophila. PMID:21952049

  5. Accuracy of a cut-off value based on the third molar index: Validation in an Australian population.

    PubMed

    Franklin, Daniel; Karkhanis, Shalmira; Flavel, Ambika; Collini, Federica; DeLuca, Stefano; Cameriere, Roberto

    2016-09-01

    According to Recommendation N°196 of the Australian Law Reform Commission (ALRC), the age at which a child reaches adulthood for the purposes of criminal law should be 18 years in all Australian jurisdictions. With specific reference to age at majority, the only tooth with development spanning adolescence (and thus the legally relevant 18 years of age) is the third molar, which limits the number of methods that can be applied from those available in the published literature. The aim of the present study is to test the accuracy of the third molar index (I3M=0.08), based on the correlation between chronological age and normalized measures of the open apices and height of the third mandibular molar, in order to assess the legal adult age of 18 years. Digital orthopantomographs of 143 living Australian subjects (72 boys and 71 girls) are analyzed. The results demonstrate that the sensitivity is 0.90 in boys and 0.90 in girls; associated specificity values are 0.85 and 0.87 respectively. We conclude that the cut-off value of I3M=0.08 is statistically robust and thus valid for forensic application in an Australian population.

  6. Sensitivity and Specificity Improvement in Abdominal Obesity Diagnosis Using Cluster Analysis during Waist Circumference Cut-Off Point Selection

    PubMed Central

    Bermúdez, Valmore; Añez, Roberto; Toledo, Alexandra; Bello, Luis; Apruzzese, Vanessa; González, Robys; Chacín, Maricarmen; Cabrera, Mayela; Cano, Clímaco; Velasco, Manuel; López-Miranda, José

    2015-01-01

    Introduction. The purpose of this study was to analyze the influence of metabolic phenotypes during the construction of ROC curves for waist circumference (WC) cutpoint selection. Materials and Methods. A total of 1,902 subjects of both genders were selected from the Maracaibo City Metabolic Syndrome Prevalence Study database. Two-Step Cluster Analysis (TSCA) was applied to select metabolically healthy and sick men and women. ROC curves were constructed to determine WC cutoff points by gender. Results. Through TSCA, metabolic phenotype predictive variables were selected: HOMA2-IR and HOMA2-βcell for women and HOMA2-IR, HOMA2-βcell, and TAG for men. Subjects were classified as healthy normal weight, metabolically obese normal weight, healthy and metabolically disturbed overweight, and healthy and metabolically disturbed obese. Final WC cutpoints were 91.50 cm for women (93.4% sensitivity, 93.7% specificity) and 98.15 cm for men (96% sensitivity, 99.5% specificity). Conclusions. TSCA in the selection of the groups used in ROC curves construction proved to be an important tool, aiding in the detection of MOWN and MHO which cannot be identified with WC alone. The resulting WC cutpoints were <91.00 cm for women and <98.00 cm for men. Furthermore, anthropometry is insufficient to determine healthiness, and, biochemical analysis is needed to properly filter subjects during classification. PMID:25945356

  7. Determination of low-pass filter cutoff frequencies for high-rate biomechanical signals obtained using videographic analysis.

    PubMed

    Fijalkowski, Ronald J; Ropella, Kristina M; Stemper, Brian D

    2009-05-01

    Diffuse brain injury (DBI) commonly results from blunt impact followed by sudden head rotation, wherein severity is a function of rotational kinematics. A noninvasive in vivo rat model was designed to further investigate this relationship. Due to brain mass differences between rats and humans, rotational acceleration magnitude indicative of rat DBI ( approximately 350 krad/s(2)) has been estimated as approximately 60 times greater than that of human DBI ( approximately 6 krad/s(2)). Prior experimental testing attempted to use standard transducers such as linear accelerometers to measure loading kinematics. However, such measurement techniques were intrusive to experimental model operation. Therefore, initial studies using this experimental model obtained rotational displacement data from videographic images and implemented a finite difference differentiation (FDD) method to obtain rotational velocity and acceleration. Unfortunately, this method amplified high-frequency, low-amplitude noise, which interfered with signal magnitude representation. Therefore, a coherent average technique was implemented to improve the measurement of rotational kinematics from videographic images, and its results were compared with those of the previous FDD method. Results demonstrated that the coherent method accurately determined a low-pass filter cutoff frequency specific to pulse characteristics. Furthermore, noise interference and signal attenuation were minimized compared with the FDD technique.

  8. Influence of temperature and upper cut-off voltage on the formation of lithium-ion cells

    NASA Astrophysics Data System (ADS)

    German, Florian; Hintennach, Andreas; LaCroix, Annette; Thiemig, Denny; Oswald, Steffen; Scheiba, Frieder; Hoffmann, Michael J.; Ehrenberg, Helmut

    2014-10-01

    The influences of temperature on the formation losses and subsequent electrical performance of Lix(Ni1/3Co1/3Mn1/3)yO2 (NCM)/graphite lithium-ion cells were investigated. It was shown that the total capacity loss during formation of a full cell at 25 °C consists of losses on the positive and negative electrode to about one half each. The losses of the negative electrode (ca. 10%) are due to solid electrolyte interphase (SEI) formation on graphite but are masked by the losses of the positive side (ca. 20%) which are mainly caused by a kinetic inhibition of NCM and are theoretically reversible when the cell is discharged to very low potentials. The total loss of a full cell fits with the loss of the positive electrode. With increased temperature the ratio of losses on positive and negative electrode decreases as the diffusion coefficient of lithium in NCM increases. In total, an elevated formation temperature leads to increased irreversible losses on both electrodes and significantly lower cell performance of graphite. The upper cut-off voltage has an influence on the positive electrode formation losses in a reversible manner. The constituents of the SEI identified via the combination of XPS and FTIR are mainly RCH2OCO2Li, RCOOLi and LiF for the outer SEI and mainly Li2CO3, Li2O and LiF for the inner SEI.

  9. Experimental differential cross sections, level densities, and spin cutoffs as a testing ground for nuclear reaction codes

    SciTech Connect

    Voinov, Alexander V.; Grimes, Steven M.; Brune, Carl R.; Burger, Alexander; Gorgen, Andreas; Guttormsen, Magne; Larsen, Ann -Cecilie; Massey, Thomas N.; Siem, Sunniva

    2013-11-08

    Proton double-differential cross sections from 59Co(α,p)62Ni, 57Fe(α,p)60Co, 56Fe(7Li,p)62Ni, and 55Mn(6Li,p)60Co reactions have been measured with 21-MeV α and 15-MeV lithium beams. Cross sections have been compared against calculations with the empire reaction code. Different input level density models have been tested. It was found that the Gilbert and Cameron [A. Gilbert and A. G. W. Cameron, Can. J. Phys. 43, 1446 (1965)] level density model is best to reproduce experimental data. Level densities and spin cutoff parameters for 62Ni and 60Co above the excitation energy range of discrete levels (in continuum) have been obtained with a Monte Carlo technique. Furthermore, excitation energy dependencies were found to be inconsistent with the Fermi-gas model.

  10. Urinary hepcidin identifies a serum ferritin cut-off for iron supplementation in young athletes: a pilot study.

    PubMed

    Borrione, P; Spaccamiglio, A; Rizzo, M; Termine, A; Chierto, E; Campostrini, N; Quaranta, F; Di Gianfrancesco, A; Pigozzi, F

    2011-01-01

    The use of iron supplements should be a judicious choice, primarily when considering the possible risks deriving from an unjustified treatment. In trained athletes, levels of ferritin between 15 and 30 microg/L are frequently observed. Within this ferritin range, the usefulness of iron supplementation is still controversial. The aim of the present study is to evaluate the clinical usefulness of hepcidin assessment in the analysis of the iron status of young non-anemic athletes. Fifty young athletes were enrolled. The subjects were divided into 4 groups according to their ferritin levels. No statistically significant difference was found regarding hepcidin levels between athletes with ferritin lower than 15 microg/L and those in the 15-30 microg/L range. Similarly, no difference was found between athletes with ferritin higher than 50 microg/L and those in the 30-50 microg/L range. On the contrary, statistically significant differences were found between athletes with ferritin levels ranging from 15 to 30 microg/L and those in the 30-50 microg/L range. The present study suggests that serum ferritin levels below 30 microg/L indicate an asymptomatic iron deficiency status inhibiting hepcidin expression and that 30 microg/L should be considered the ferritin cut-off when considering an iron supplementation in young athletes.

  11. Core-Cutoff Tool

    NASA Technical Reports Server (NTRS)

    Gheen, Darrell

    2007-01-01

    A tool makes a cut perpendicular to the cylindrical axis of a core hole at a predetermined depth to free the core at that depth. The tool does not damage the surrounding material from which the core was cut, and it operates within the core-hole kerf. Coring usually begins with use of a hole saw or a hollow cylindrical abrasive cutting tool to make an annular hole that leaves the core (sometimes called the plug ) in place. In this approach to coring as practiced heretofore, the core is removed forcibly in a manner chosen to shear the core, preferably at or near the greatest depth of the core hole. Unfortunately, such forcible removal often damages both the core and the surrounding material (see Figure 1). In an alternative prior approach, especially applicable to toxic or fragile material, a core is formed and freed by means of milling operations that generate much material waste. In contrast, the present tool eliminates the damage associated with the hole-saw approach and reduces the extent of milling operations (and, hence, reduces the waste) associated with the milling approach. The present tool (see Figure 2) includes an inner sleeve and an outer sleeve and resembles the hollow cylindrical tool used to cut the core hole. The sleeves are thin enough that this tool fits within the kerf of the core hole. The inner sleeve is attached to a shaft that, in turn, can be attached to a drill motor or handle for turning the tool. This tool also includes a cutting wire attached to the distal ends of both sleeves. The cutting wire is long enough that with sufficient relative rotation of the inner and outer sleeves, the wire can cut all the way to the center of the core. The tool is inserted in the kerf until its distal end is seated at the full depth. The inner sleeve is then turned. During turning, frictional drag on the outer core pulls the cutting wire into contact with the core. The cutting force of the wire against the core increases with the tension in the wire and, hence, with the frictional drag acting on the outer sleeve. As the wire cuts toward the center of the core, the inner sleeve rotates farther with respect to the outer sleeve. Once the wire has cut to the center of the core, the tool and the core can be removed from the hole. The proper choice of cutting wire depends on the properties of the core material. For a sufficiently soft core material, a nonmetallic monofilament can be used. For a rubber-like core material, a metal wire can be used. For a harder core material, it is necessary to use an abrasive wire, and the efficiency of the tool can be increased greatly by vacuuming away the particles generated during cutting. For a core material that can readily be melted or otherwise cut by use of heat, it could be preferable to use an electrically heated cutting wire. In such a case, electric current can be supplied to the cutting wire, from an electrically isolated source, via rotating contact rings mounted on the sleeves.

  12. Cut-off value of red-blood-cell-bound IgG for the diagnosis of Coombs-negative autoimmune hemolytic anemia.

    PubMed

    Kamesaki, Toyomi; Oyamada, Takashi; Omine, Mitsuhiro; Ozawa, Keiya; Kajii, Eiji

    2009-02-01

    Direct antiglobulin test (DAT)-negative autoimmune hemolytic anemia (Coombs-negative AIHA) is characterized by laboratory evidence of in vivo hemolysis, together with a negative DAT performed by conventional tube technique (CTT) in clinically suspected AIHA patients. The immunoradiometric assay (IRMA) for red-blood-cell-bound immunoglobulin G (RBC-IgG) can be used to diagnose patients in whom CTT does not detect low levels of red cell autoantibodies. We investigated the diagnostic cutoff value of the IRMA for RBC-IgG in Coombs-negative AIHA and calculated its sensitivity and specificity. Of the 140 patients with negative DAT by CTT referred to our laboratory with undiagnosed hemolytic anemia, AIHA was clinically diagnosed in 64 patients (Coombs-negative AIHA). The numbers of Coombs-negative AIHA and non-AIHA patients changed with age and gender. The cutoff values were determined from receiver operating characteristic (ROC) curve according to age and gender. The IRMA for RBC-IgG proved to be sensitive (71.4%) and specific (87.8%) when using these cutoffs. Using these cutoffs for 41 patients with negative DAT referred to our laboratory in 2006, all the pseudonegative cases were treated with steroids before the test. The 31 untreated cases could be grouped using one cutoff value of 78.5 and showed 100% sensitivity and 94% specificity, independent of gender and age. Results indicate that RBC-IgG could become a standard approach for the diagnosis of Coombs-negative AIHA, when measured before treatment.

  13. Cutoff value of thyroid uptake of (99m)Tc-pertechnetate to discriminate between Graves' disease and painless thyroiditis: a single center retrospective study.

    PubMed

    Uchida, Toyoyoshi; Suzuki, Ruriko; Kasai, Takatoshi; Onose, Hiroyuki; Komiya, Koji; Goto, Hiromasa; Takeno, Kageumi; Ishii, Shinya; Sato, Junko; Honda, Akira; Kawano, Yui; Himuro, Miwa; Yamada, Emiko; Yamada, Tetsu; Watada, Hirotaka

    2016-01-01

    Thyroid uptake of (99m)Tc-pertechnetate is a useful way to determine the cause of thyrotoxicosis. In daily clinical practice, (99m)Tc-pertechnetate uptake is used to discriminate between Graves' disease and painless thyroiditis when clinical information is not enough to make the distinction. However, since the optimal cutoff value of (99m)Tc-pertechnetate uptake has not yet been elucidated, our aim was to determine this value. We recruited patients with thyrotoxicosis in whom (99m)Tc-pertechnetate uptake was measured in clinical settings between 2009 and 2013. Three experienced endocrinologists (who were blinded to the value of (99m)Tc-pertechnetate uptake and initial treatment) diagnosed the cause of thyrotoxicosis based on thyrotropin, free triiodothyronine, free thyroxine, and thyrotropin receptor antibody levels, and by ultrasound findings and using images of thyroid uptake of (99m)Tc-pertechnetate without the actual values. Ninety-four patients diagnosed as having Graves' disease or painless thyroiditis were finally included. According to the diagnosis, the optimal cutoff value of (99m)Tc-pertechnetate uptake was determined by receiver operating characteristics analysis. A cutoff value of 1.0% provided optimal sensitivity and specificity of 96.6% and 97.1%, respectively. Then, its validity was confirmed in 78 patients with confirmed Graves' disease or painless thyroiditis diagnosed at another institute. Applying this cutoff value to the patients with thyrotoxicosis revealed positive and negative predictive values for Graves' disease of 100% and 88.9%, respectively. In conclusion, a cutoff value for (99m)Tc-pertechnetate uptake of 1.0% was useful to discriminate between Graves' disease and painless thyroiditis.

  14. Predicting Grade 3 Acute Diarrhea During Radiation Therapy for Rectal Cancer Using a Cutoff-Dose Logistic Regression Normal Tissue Complication Probability Model

    SciTech Connect

    Robertson, John M.; Soehn, Matthias; Yan Di

    2010-05-01

    Purpose: Understanding the dose-volume relationship of small bowel irradiation and severe acute diarrhea may help reduce the incidence of this side effect during adjuvant treatment for rectal cancer. Methods and Materials: Consecutive patients treated curatively for rectal cancer were reviewed, and the maximum grade of acute diarrhea was determined. The small bowel was outlined on the treatment planning CT scan, and a dose-volume histogram was calculated for the initial pelvic treatment (45 Gy). Logistic regression models were fitted for varying cutoff-dose levels from 5 to 45 Gy in 5-Gy increments. The model with the highest LogLikelihood was used to develop a cutoff-dose normal tissue complication probability (NTCP) model. Results: There were a total of 152 patients (48% preoperative, 47% postoperative, 5% other), predominantly treated prone (95%) with a three-field technique (94%) and a protracted venous infusion of 5-fluorouracil (78%). Acute Grade 3 diarrhea occurred in 21%. The largest LogLikelihood was found for the cutoff-dose logistic regression model with 15 Gy as the cutoff-dose, although the models for 20 Gy and 25 Gy had similar significance. According to this model, highly significant correlations (p <0.001) between small bowel volumes receiving at least 15 Gy and toxicity exist in the considered patient population. Similar findings applied to both the preoperatively (p = 0.001) and postoperatively irradiated groups (p = 0.001). Conclusion: The incidence of Grade 3 diarrhea was significantly correlated with the volume of small bowel receiving at least 15 Gy using a cutoff-dose NTCP model.

  15. Cut-off net acid generation pH in predicting acid-forming potential in mine spoils.

    PubMed

    Liao, B; Huang, L N; Ye, Z H; Lan, C Y; Shu, W S

    2007-01-01

    Acidification of mine wastes can lead to a series of environmental problems, such as acid drainage, heavy metal mobilization, and ecosystem degradation. Prediction of acid-forming potential is one of the key steps in management of sulfide-bearing mine wastes. In this paper, the acid-forming potential of 180 mine waste samples collected from 17 mine sites in China were studied using a net acid generation (NAG) method. The samples contained different contents of total sulfur (ranging from 0.6 to 200 g kg(-1)), pyritic sulfur (ranging from 0 to 100 g kg(-1)), and acid neutralization capacity (ANC, ranging from -41 to 274 kg H2SO4 t(-1)). Samples with high acid-forming potential are generally due to their high sulfur content or low acid neutralization capacity. After the samples were oxidized by H2O2, the amounts of acid generation and the final NAG pH were measured. Results indicated that the final NAG pH gave a well-defined demarcation between acid-forming and non-acid-forming materials. Samples with final NAG pH >or= 5 could be classified as non-acid-forming materials, while those with NAG pH 2.5, but < 5, had low risk of being acid-forming. The confirmation of cut-off NAG pH will be used as a rapid and cost-effective operational monitoring tool for the in-pit prediction of acid-forming potential of mine wastes and classification of waste types.

  16. Establishing New Cut-Off Limits for Galactose 1-Phosphate-Uridyltransferase Deficiency for the Dutch Newborn Screening Programme.

    PubMed

    Kemper, E A; Boelen, A; Bosch, A M; van Veen-Sijne, M; van Rijswijk, C N; Bouva, M J; Fingerhut, R; Schielen, P C J I

    2017-01-01

    Newborn screening for classical galactosemia in the Netherlands is performed by five laboratories and is based on the measurement of galactose 1-phosphate-uridyltransferase (GALT) activity and total galactose (TGAL) in heel prick blood spots. Unexpected problems with the GALT assay posed a challenge to switch to a new assay. The aim of this study was to make an analytical and clinical evaluation of GALT assays to replace the current assay and to establish new cut-off values (COVs).First, the manual assay from PerkinElmer (NG-1100) and the GSP assay were compared by analyzing 626 anonymous heel prick samples in parallel. Secondly, a manual GSP method was evaluated and 2,052 samples were compared with the automated GSP assay. Finally, a clinical evaluation was performed by collecting data from 93 referred newborns.No satisfactory correlation was observed between GALT activity measured with the manual NG-1100 assay and the automated GSP assay. An acceptable correlation was found between the manual and automated GSP assay. Intra- and inter-assay variation of the automated GSP were 1.8-10.0% and 3.1-13.9%, respectively. Evaluation of clinical data demonstrated that adjusting the COVs for GALT to 2.0 U/dl and TGAL to 1,100 μmol/l improved specificity of screening for classical galactosemia.An assay designed for automated processing to measure GALT activity in heel prick samples works equally well when processed manually. We therefore adopted both methods in the Dutch screening laboratories. As a result of this evaluation new COVs for GALT and TGAL have been introduced and are valid from July 2015.

  17. Prevalence of the metabolic syndrome in Spain using regional cutoff points for waist circumference: the di@bet.es study.

    PubMed

    Marcuello, Clara; Calle-Pascual, Alfonso L; Fuentes, Manuel; Runkle, Isabelle; Rubio, Miguel A; Montañez, Carmen; Rojo-Martinez, Gemma; Soriguer, Federico; Bordiu, Elena; Goday, Albert; Bosch-Comas, Anna; Carmena, Rafael; Casamitjana, Roser; Castaño, Luis; Castell, Conxa; Catalá, Miguel; Delgado, Elias; Franch, Josep; Gaztambide, Sonia; Girbés, Juan; Gomis, Ramon; Urrutia, Ines; López-Alba, Alfonso; Martínez-Larrad, Maria T; Menéndez, Eldelmiro; Mora-Peces, Inmaculada; Ortega, Emilio; Pascual-Manich, Gemma; Serrano-Rios, Manuel; Valdés, Sergio; Vázquez, Jose A; Vendrell, Joan

    2013-08-01

    The aim of the study is to assess the prevalence of metabolic syndrome (MetS) in Spain using specific cutoff points for waist circumference (WC) (>94.5 cm for men and >89.5 cm for women) and evaluating the influence of several socio-demographic and economic factors. Data on MetS were obtained from a national study of 4,727 subjects from 18 to 90 years of age, conducted in Spain between 2009 and 2010 (The di@bet.es study). MetS was defined applying the new Harmonized definition (evaluating the use of abdominal obesity (AO) as a obligatory criterion for MetS or not) as well as with other widely used criteria. Results were then compared with data from previous studies. Multiple logistic regression models were used to evaluate the influence of different social factors. The age-standardized MetS prevalence was 38.37 % (CI 35.74-40.99) in men and 29.62 % (CI 27.56-31.69) in women, when AO was required as a diagnostic criterion; 42.13 % (CI 39.37-44.89) and 32.31 % (CI 30.15-34.47) in men and women, respectively, if AO was not considered mandatory. Prevalence of MetS increased with age (p < 0.001 for trend). Women with a lower educational level were more likely to have MetS (OR 4.4; 95 % CI: 2.84-6.7) as compared with those with a higher educational level. Subjects with MetS had a worse physical quality of life. The combination of AO, hypertension and carbohydrate alterations was the most common MetS' pattern. A high prevalence of MetS was detected in the Spanish population especially in men, the elderly and women with a low educational level.

  18. Modelling the influence of high currents on the cutoff frequency in Si/SiGe/Si heterojunction transistors

    NASA Astrophysics Data System (ADS)

    Briggs, P. J.; Walker, A. B.; Herbert, D. C.

    1998-05-01

    A one-dimensional self-consistent bipolar Monte Carlo simulation code has been used to model carrier mobilities in strained doped SiGe and the base-collector region of Si/SiGe/Si and SiC/Si heterojunction bipolar transistors (HBTs) with wide collectors, to study the variation of the cutoff frequency 0268-1242/13/5/005/img6 with collector current density 0268-1242/13/5/005/img7. Our results show that while the presence of strain enhances the electron mobility, the scattering from alloy disorder and from ionized impurities reduces the electron mobility so much that it is less than that of Si at the same doping level, leading to larger base transit times 0268-1242/13/5/005/img8 and hence poorer 0268-1242/13/5/005/img6 performance for large 0268-1242/13/5/005/img7 for an Si/SiGe/Si HBT than for an SiC/Si HBT. At high values of 0268-1242/13/5/005/img7, we demonstrate the formation of a parasitic electron barrier at the base-collector interface which causes a sharp increase in 0268-1242/13/5/005/img8 and hence a dramatic reduction in 0268-1242/13/5/005/img6. Based on a comparison of the height of this parasitic barrier with estimates from an analytical model, we suggest a physical mechanism for base pushout after barrier formation that differs somewhat from that given for the analytical model.

  19. Combined Effect of an Atmospheric River and a Cut-off Low in Hiroshima Flooding Event on August 19, 2014

    NASA Astrophysics Data System (ADS)

    Takayabu, Y. N.; Hirota, N.; Kato, M.; Arakane, S.

    2015-12-01

    An extraordinary precipitation over 100 mmhr-1in Hiroshima on August 19, 2014, caused a flash flood which resulted in 74 fatalities and collapse of 330 houses. In order to examine the meteorological background of this flooding event, we carried out a detailed analysis utilizing rain gauge data, satellite precipitation dataset, and a meso scale and a global scale objective analyses provided from the Japan Meteorological Agency. Then, we performed numerical experiments using a nonhydrostatic compressible equation model called the Cloud-Resolving Storm Simulator (CReSS). As a result, a combined effect of an atmospheric river (AR) and a cut-off low (COL) in this flooding event was elucidated. During the event, a filamentary transport of moisture extending from the Indochina Peninsula to the Japanese Islands was observed along the southern side of the subtropical jet, forming an AR. This AR had a deep structure with an amount of free tropospheric moisture comparable to that of the boundary layer. Concurrently, there was a COL, detached from the Mid-Pacific Trough, moving northwestward toward the Japanese Archipelago. With various sensitivity experiments, we concluded that a mid-tropospheric instability associated with the cold core of the COL and a dynamical ascent induced in its foreside, collaboratively worked with the anomalous moisture in the free troposphere associated with the AR, to extraordinarily enhance the precipitation over Hiroshima region. An orographic effect to concentrate the precipitation in this region was also confirmed. An implication on a difference in effects of AR in this event with a climatologically moist boundary layer, from those in the US west coast with a very dry environment, was also obtained. Acknowledgment: This study is supported by the Environment Research and Technology Development Fund (2-1503) of the Ministry of the Environment, Japan, and by the Ministry of Education, Culture, Sports, Science and Technology, Japan.

  20. Detectability of small blood vessels with high-frequency power Doppler and selection of wall filter cut-off velocity for microvascular imaging.

    PubMed

    Pinter, Stephen Z; Lacefield, James C

    2009-07-01

    Power Doppler imaging of physiologic and pathologic angiogenesis is widely used in preclinical studies to track normal development, disease progression and treatment efficacy but can be challenging given the presence of small blood vessels and slow flow velocities. Power Doppler images can be plagued with false-positive color pixels or undetected vessels, thereby complicating the interpretation of vascularity metrics such as color pixel density (CPD). As an initial step toward improved microvascular quantification, flow-phantom experiments were performed to establish relationships between vessel detection and various combinations of vessel size (160, 200, 250, 300 and 360 microm), flow velocity (4, 3, 2, 1 and 0.5 mm/s) and transducer frequency (30 and 40 MHz) while varying the wall filter cut-off velocity. Receiver operating characteristic (ROC) curves and areas under ROC curves indicate that good vessel detection performance can be achieved with a 40-MHz transducer for flow velocities > or =2 mm/s and with a 30-MHz transducer for flow velocities > or =1 mm/s. In the second part of the analysis, CPD was plotted as a function of wall filter cut-off velocity for each flow-phantom data set. Three distinct regions were observed: overestimation of CPD at low cut-offs, underestimation of CPD at high cut-offs and a plateau at intermediate cut-offs. The CPD at the plateau closely matched the phantom's vascular volume fraction and the length of the plateau corresponded with the flow-detection performance of the Doppler system assessed using ROC analysis. Color pixel density vs. wall filter cut-off curves from analogous in vivo experiments exhibited the same shape, including a distinct CPD plateau. The similar shape of the flow-phantom and in vivo curves suggests that the presence of a plateau in vivo can be used to identify the best-estimate CPD value that can be treated as a quantitative vascularity metric. The ability to identify the best CPD estimate is expected to

  1. Body composition-derived BMI cut-offs for overweight and obesity in Indians and Creoles of Mauritius: comparison with Caucasians

    PubMed Central

    Hunma, S; Ramuth, H; Miles-Chan, J L; Schutz, Y; Montani, J-P; Joonas, N; Dulloo, A G

    2016-01-01

    Background and Aims: Global estimates of overweight and obesity prevalence are based on the World Health Organisation (WHO) body mass index (BMI) cut-off values of 25 and 30 kg m−2, respectively. To validate these BMI cut-offs for adiposity in the island population of Mauritius, we assessed the relationship between BMI and measured body fat mass in this population according to gender and ethnicity. Methods: In 175 young adult Mauritians (age 20-42 years) belonging to the two main ethnic groups—Indians (South Asian descent) and Creoles (African/Malagasy descent), body weight, height and waist circumference (WC) were measured, total body fat assessed by deuterium oxide (D2O) dilution and trunk (abdominal) fat by segmental bioimpedance analysis. Results: Compared to body fat% predicted from BMI using Caucasian-based equations, body fat% assessed by D2O dilution in Mauritians was higher by 3–5 units in Indian men and women as well as in Creole women, but not in Creole men. This gender-specific ethnic difference in body composition between Indians and Creoles is reflected in their BMI–Fat% relationships, as well as in their WC–Trunk Fat% relationships. Overall, WHO BMI cut-offs of 25 and 30 kg m−2 for overweight and obesity, respectively, seem valid only for Creole men (~24 and 29.5, respectively), but not for Creole women whose BMI cut-offs are 2–4 units lower (21–22 for overweight; 27–28 for obese) nor for Indian men and women whose BMI cut-offs are 3–4 units lower (21–22 for overweight; 26–27 for obese). Conclusions: The use of BMI cut-off points for classifying overweight and obesity need to take into account both ethnicity and gender to avoid gross adiposity status misclassification in this population known to be at high risk for type-2 diabetes and cardiovascular diseases. This is particularly of importance in obesity prevention strategies both in clinical medicine and public health. PMID:27698347

  2. Spectral properties and the effect on redshift cut-off of compact active galactic nuclei from the AT20G survey

    NASA Astrophysics Data System (ADS)

    Chhetri, R.; Ekers, R. D.; Mahony, E. K.; Jones, P. A.; Massardi, M.; Ricci, R.; Sadler, E. M.

    2012-05-01

    Spectral index has been traditionally used to separate extragalactic radio sources into compact and extended populations, with the spectral transition placed variably between -0.4 and -0.6. We use high angular resolution data, measured from visibility of sources at the longest baseline of 4500 m of the Australia Telescope Compact Array (ATCA), for the Australia Telescope 20 GHz (AT20G) survey to obtain angular size information for over 94 per cent of AT20G sources. We confirm the previous AT20G result that due to the high survey frequency of 20 GHz, the source population is strongly dominated by compact sources (79 per cent). At 0.15-arcsec angular resolution limit, we show a very strong correlation between the compact and extended sources with flat and steep-spectrum sources respectively for spectral indices obtained between 1 and 5 GHz. Thus, we provide a firm physical basis for the traditional spectral classification into flat and steep-spectrum sources to select compact and extended sources. We find that for spectral indices between 1 and 5 GHz, the cut-offs at -0.4 and -0.5 are quite similar to the optimum cut-off of -0.46 and, hence, recommend the continued use of -0.5 for future studies. We use the recently published redshift data to study the effect of spectral curvature on the redshift cut-off of compact active galactic nuclei (AGNs). Using spectral indices at different frequencies, we correct for the redshift effect and also produce rest-frame frequency spectra for compact sources for redshifts up to z˜ 5. We show that the spectra of most compact sources are flat to ˜30 GHz and then start to steepen. At higher frequencies, the spectra of both compact and extended sources are steep, so the use of spectral index does not separate the compact and extended source populations as well as in lower frequencies. We also find that due to spectral steepening at high frequencies, surveys of compact sources at higher frequencies (ν > 5 GHz) will have redshift cut-off

  3. Cut-off values of serum IgE (total and A. fumigatus -specific) and eosinophil count in differentiating allergic bronchopulmonary aspergillosis from asthma.

    PubMed

    Agarwal, Ritesh; Aggarwal, Ashutosh N; Garg, Mandeep; Saikia, Biman; Chakrabarti, Arunaloke

    2014-11-01

    The cut-off values of immunological tests employed in diagnosis of allergic bronchopulmonary aspergillosis (ABPA) have never been validated. Herein, we compare the immunological findings in patients with ABPA and asthma using receiver operating characteristic analysis. Consecutive asthmatic subjects underwent all the following investigations: Aspergillus skin test, IgE levels (total and A. fumigatus-specific), Aspergillus precipitins, eosinophil count, chest radiograph and CT chest. There were 372 subjects (179 men, mean age 35.9 years) with a mean asthma duration of 8 years. ABPA was diagnosed in 76 patients (64 bronchiectasis, 12 without bronchiectasis). ABPA was separated from asthma using the best cut-off values of total IgE, A. fumigatus IgE and total eosinophil count of 2347 IU ml(-1) , 1.91 kUA l(-1) and 507 cells per μl respectively. The sensitivity/specificity of these parameters were 87/81%; 99/87%; and, 79/76% respectively. The corresponding AUC values were 0.95, 0.90 and 0.82 respectively. The combination of these three tests at the aforementioned cut-offs provided 100% specificity. Our study provides evidence-based cut-off values of IgE (total and A. fumigatus-specific) and eosinophil counts in differentiating ABPA from asthma. As this is a single centre retrospective study, further studies from different centres are required, as these values could vary by ethnicity and environmental exposure.

  4. The impact of lowering the cut-off value on the sensitivity of the Platelia Elisa IgG (Bio-Rad) test for toxoplasmosis diagnosis

    PubMed Central

    Mouri, Oussama; Kendjo, Eric; Touafek, Feriel; Fekkar, Arnaud; Konte, Ousmane; Imbert, Sebastien; Courtin, Régis; Mazier, Dominique; Paris, Luc

    2015-01-01

    Determining specific immune status against Toxoplasma gondii is essential for assessing the risk of reactivation in immunocompromised patients or defining serological monitoring and appropriate prophylactic measures during pregnancy. In France, toxoplasmosis serological screening requires systematic testing for IgM and IgG antibodies. The Platelia Toxo IgG and IgM test (Bio-Rad) is one of the most widely used tests for anti-toxoplasmic antibody detection. We performed a study on 384 sera, including 123 IgG negative (<6 IU/mL) and 261 IgG equivocal (6–9 IU/mL) sera tested with Platelia Toxo IgG and collected during routine screening at Pitié-Salpêtrière Hospital, Paris, France to determine the best-performing IgG titer cut-off value. Out of these 383 sera, 298 were IgM negative by Platelia Toxo IgM and 86 were IgM positive. All sera were also tested against Toxo IgG II LD BIO western blot test as confirmation. Our results indicated that an IgG titer cut-off value of ≥4.4 IU/mL for the Platelia Toxo IgG met the definition of positivity, a value significantly lower than that indicated by the manufacturers. In the presence of IgM antibodies, the IgG titer cut-off decreased significantly to a value ≥0.2 IU/mL. This latter cut-off also allowed adequate diagnosis of proven toxoplasmosis seroconversion in 76.7% of cases (33/43). Our findings may improve toxoplasmosis care by reducing therapeutic intervention time and eliminating the need for further serological monitoring. PMID:26187780

  5. Cut-off points for mild, moderate, and severe pain on the visual analogue scale for pain in patients with chronic musculoskeletal pain.

    PubMed

    Boonstra, Anne M; Schiphorst Preuper, Henrica R; Balk, Gerlof A; Stewart, Roy E

    2014-12-01

    The aim of this study was to find the cut-off points on the visual analogue scale (VAS) to distinguish among mild, moderate, and severe pain, in relation to the following: pain-related interference with functioning; verbal description of the VAS scores; and latent class analysis for patients with chronic musculoskeletal pain. A total of 456 patients were included. Pain was assessed using the VAS and verbal rating scale; functioning was assessed using the domains of the Short Form (36) Health Survey (SF-36). Eight cut-off point schemes were tested using multivariate analysis of variance (MANOVA), ordinal logistic regression, and latent class analysis. The study results showed that VAS scores ⩽ 3.4 corresponded to mild interference with functioning, whereas 3.5 to 6.4 implied moderate interference, and ⩾ 6.5 implied severe interference. VAS scores ⩽ 3.4 were best described for patients with chronic musculoskeletal pain as mild pain, 3.5 to 7.4 as moderate pain, and ⩾ 7.5 as severe pain. Latent class analysis found that a 3-class solution fitted best, resulting in the classes 0.1 to 3.8, 3.9 to 5.7, and 5.8 to 10 cm. Findings from our study agree with those of some other studies, although many other studies found different optimal cut-off point schemes. As there appear to be no universally accepted cut-off points, and in view of the low-to-moderate associations between VAS scores and functioning and between VAS and verbal rating scale scores, the correct classification of VAS scores as mild, moderate. or severe in clinical practice seems doubtful.

  6. Different cutoff values for 10-m walking speed simply classification of walking independence in stroke patients with or without cognitive impairment

    PubMed Central

    Yoshimoto, Yoshinobu; Oyama, Yukitsuna; Tanaka, Mamoru

    2015-01-01

    [Purpose] The aim of this study was to determine the threshold for classifying walking independence in stroke patients with and without cognitive disorders. [Subjects] The subjects were 130 patients with initial stroke hemiplegia. [Methods] The following factors were analyzed for associations with walking independence: Brunnstrom stage, one-leg standing time on the paralytic side, one-leg standing time on the non-paralytic side, and 10-m walking speed. We classified the patients with Mini-Mental State Examination (MMSE) scores ≥24 points into the high-score group and those with MMSE scores of ≤23 points into the low-score group and examined the main factors and cutoff values associated with walking independence in each group. [Results] The high-score group included 69 subjects (53.1%), and the low-score group included 61 subjects (46.9%). The primary factor associated with high MMSE scores among the stroke patients was the 10-m walking time. Using a cutoff level for the 10-m walking speed of 41.4 m/min resulted in a positive likelihood ratio of 6.3. The primary factor associated with low MMSE scores among the stroke patients was the 10-m walking time. Using a cutoff level for the 10-m walking speed of 48.0 m/min resulted in a positive likelihood ratio of 7.6. [Conclusion] The cutoff value for the 10-m walking speed can be used to evaluate walking independence in patients with stroke among patients with high or low MMSE scores. PMID:26157250

  7. Different cutoff values for 10-m walking speed simply classification of walking independence in stroke patients with or without cognitive impairment.

    PubMed

    Yoshimoto, Yoshinobu; Oyama, Yukitsuna; Tanaka, Mamoru

    2015-05-01

    [Purpose] The aim of this study was to determine the threshold for classifying walking independence in stroke patients with and without cognitive disorders. [Subjects] The subjects were 130 patients with initial stroke hemiplegia. [Methods] The following factors were analyzed for associations with walking independence: Brunnstrom stage, one-leg standing time on the paralytic side, one-leg standing time on the non-paralytic side, and 10-m walking speed. We classified the patients with Mini-Mental State Examination (MMSE) scores ≥24 points into the high-score group and those with MMSE scores of ≤23 points into the low-score group and examined the main factors and cutoff values associated with walking independence in each group. [Results] The high-score group included 69 subjects (53.1%), and the low-score group included 61 subjects (46.9%). The primary factor associated with high MMSE scores among the stroke patients was the 10-m walking time. Using a cutoff level for the 10-m walking speed of 41.4 m/min resulted in a positive likelihood ratio of 6.3. The primary factor associated with low MMSE scores among the stroke patients was the 10-m walking time. Using a cutoff level for the 10-m walking speed of 48.0 m/min resulted in a positive likelihood ratio of 7.6. [Conclusion] The cutoff value for the 10-m walking speed can be used to evaluate walking independence in patients with stroke among patients with high or low MMSE scores.

  8. Endogenous gamma-hydroxybutyric acid (GHB) concentrations in post-mortem specimens and further recommendation for interpretative cut-offs.

    PubMed

    Andresen-Streichert, Hilke; Jensen, P; Kietzerow, J; Schrot, M; Wilke, N; Vettorazzi, E; Mueller, A; Iwersen-Bergmann, S

    2015-01-01

    When interpreting gamma-hydroxybutyric acid (GHB) concentrations in post-mortem specimens, a possible increase in GHB concentrations because of post-mortem generation must be considered. In this study, endogenous GHB concentrations in post-mortem biological fluids were investigated. Additionally, we review post-mortem GHB concentrations already published in the literature. Heart and peripheral blood samples, cerebrospinal fluid, urine, and vitreous humor were collected from 64 autopsies in subjects where the cause of death excluded GHB exposure. Sample analysis was carried out either on the day of autopsy or later after immediate freezing and storage at -20 °C. GHB concentrations in venous blood samples (n = 61) were <0.6-28.7 mg/L (mean 11.9 mg/L; median 10.6 mg/L), <0.6-65.3 mg/L (mean 15.2 mg/L; median 12.8 mg/L) in heart blood (n = 56), <0.6-25.1 mg/L (mean 6.0 mg/L; median 3.8 mg/L) in urine (n = 50), <0.6-39.0 mg/L (mean 9.6 mg/L; median 7.5 mg/L), in vitreous humor (n = 54), and <0.6-24.0 mg/L (mean 4.2 mg/L; median 3.2 mg/L) in cerebrospinal fluid (n = 52). There was no significant difference between GHB concentrations in cases where there were signs of beginning putrefaction at the time of autopsy (n = 9) and cases without obvious signs of putrefaction. In one case with advanced putrefaction, the GHB concentration in venous blood was 32.7 mg/L. In conclusion, for post-mortem venous blood, urine, and cerebrospinal fluid, an interpretative cut-off of 30 mg/L for GHB concentrations is suggested in cases where GHB analysis is conducted on the day of sample collection at autopsy or if samples have been stored at -20 °C immediately after collection.

  9. Epidemiological cutoff values for azoles and Aspergillus fumigatus based on a novel mathematical approach incorporating cyp51A sequence analysis.

    PubMed

    Meletiadis, J; Mavridou, E; Melchers, W J G; Mouton, J W; Verweij, P E

    2012-05-01

    Epidemiological cutoff values (ECV) are commonly used to separate wild-type isolates from isolates with reduced susceptibility to antifungal drugs, thus setting the foundation for establishing clinical breakpoints for Aspergillus fumigatus. However, ECVs are usually determined by eye, a method which lacks objectivity, sensitivity, and statistical robustness and may be difficult, in particular, for extended and complex MIC distributions. We therefore describe and evaluate a statistical method of MIC distribution analysis for posaconazole, itraconazole, and voriconazole for 296 A. fumigatus isolates utilizing nonlinear regression analysis, the normal plot technique, and recursive partitioning analysis incorporating cyp51A sequence data. MICs were determined by using the CLSI M38-A2 protocol (CLSI, CLSI document M38-A2, 2008) after incubation of the isolates for 48 h and were transformed into log(2) MICs. We found a wide distribution of MICs of all azoles, some ranging from 0.02 to 128 mg/liter, with median MICs of 32 mg/liter for itraconazole, 4 mg/liter for voriconazole, and 0.5 mg/liter for posaconazole. Of the isolates, 65% (192 of 296) had mutations in the cyp51A gene, and the majority of the mutants (90%) harbored tandem repeats in the promoter region combined with mutations in the cyp51A coding region. MIC distributions deviated significantly from normal distribution (D'Agostino-Pearson omnibus normality test P value, <0.001), and they were better described with a model of the sum of two Gaussian distributions (R(2), 0.91 to 0.96). The normal plot technique revealed a mixture of two populations of MICs separated by MICs of 1 mg/liter for itraconazole, 1 mg/liter for voriconazole, and 0.125 mg/liter for posaconazole. Recursive partitioning analysis confirmed these ECVs, since the proportions of isolates harboring cyp51A mutations associated with azole resistance were less than 20%, 20 to 30%, and >70% when the MICs were lower than, equal to, and higher than the

  10. Medium Cut-Off (MCO) Membranes Reduce Inflammation in Chronic Dialysis Patients—A Randomized Controlled Clinical Trial

    PubMed Central

    Zickler, Daniel; Schindler, Ralf; Willy, Kevin; Martus, Peter; Pawlak, Michael; Storr, Markus; Hulko, Michael; Boehler, Torsten; Glomb, Marcus A.; Liehr, Kristin; Henning, Christian; Templin, Markus; Trojanowicz, Bogusz; Ulrich, Christof; Werner, Kristin; Fiedler, Roman; Girndt, Matthias

    2017-01-01

    Background To increase the removal of middle-sized uremic toxins a new membrane with enhanced permeability and selectivity, called Medium Cut-Off membrane (MCO-Ci) has been developed that at the same time ensures the retention of albumin. Because many middle-sized substances may contribute to micro-inflammation we hypothesized that the use of MCO-Ci influences the inflammatory state in hemodialysis patients. Methods The randomized crossover trial in 48 patients compared MCO-Ci dialysis to High-flux dialysis of 4 weeks duration each plus 8 weeks extension phase. Primary endpoint was the gene expression of TNF-α and IL-6 in peripheral blood mononuclear cells (PBMCs), secondary endpoints were plasma levels of specified inflammatory mediators and cytokines. Results After four weeks of MCO-Ci the expression of TNF-α mRNA (Relative quantification (RQ) from 0.92 ± 0.34 to 0.75 ± 0.31, -18.5%, p<0.001)-α and IL-6 mRNA (RQ from 0.78 ± 0.80 to 0.60 ± 0.43, -23.1%, p<0.01) was reduced to a significantly greater extent than with High-flux dialyzers (TNF mRNA-RQ: -14.3%; IL-6 mRNA-RQ: -3.5%). After retransformation of logarithmically transformed data, measurements after MCO were reduced to 82% of those after HF (95% CI 74%–91%). 4 weeks use of MCO-Ci resulted in long-lasting change in plasma levels of several cytokines and other substances with a significant decrease for sTNFR1, kappa and lambda free light chains, urea and an increase for Lp-PLA2 (PLA2G7) compared to High-flux. Albumin levels dropped significantly after 4 weeks of MCO dialysis but increased after additional 8 weeks of MCO dialysis. Twelve weeks treatment with MCO-Ci was well tolerated regarding the number of (S)AEs. In the extension period levels of CRP, TNF-α-mRNA and IL-6 mRNA remained stable in High-flux as well as in MCO-Ci. Conclusions MCO-Ci dialyzers modulate inflammation in chronic HD patients to a greater extent compared to High-flux dialyzers. Transcription of pro-inflammatory cytokines in

  11. Effect of Accelerometer Cut-Off Points on the Recommended Level of Physical Activity for Obesity Prevention in Children

    PubMed Central

    Dygrýn, Jan; Mitáš, Josef; Jakubec, Lukáš; Frömel, Karel

    2016-01-01

    There is no general consensus regarding which accelerometer cut-off point (CoP) is most acceptable to estimate the time spent in moderate-to-vigorous physical activity (MVPA) in children and choice of an appropriate CoP primarily remains a subjective decision. Therefore, this study aimed to analyze the influence of CoP selection on the mean MVPA and to define the optimal thresholds of MVPA derived from different accelerometer CoPs to avoid overweight/obesity and adiposity in children aged 7 to 12 years. Three hundred six children participated. Physical activity (PA) was monitored for seven consecutive days using an ActiGraph accelerometer (model GT3X) and the intensity of PA was estimated using the five most frequently published CoPs. Body adiposity was assessed using a multi-frequency bioelectrical impedance analysis. There was found a wide range of mean levels of MVPA that ranged from 27 (Puyau CoP) to 231 min∙d–1 (Freedson 2005 CoP). A receiver operating characteristic curve analysis indicated that the optimal thresholds for counts per minute (cpm) and MVPA derived from the Puyau CoP was the most useful in classifying children according to their body mass index (BMI) and fat mass percentage (FM%). In the total sample, the optimal thresholds of the MVPA derived from the Puyau CoP were 22 and 23 min∙d–1 when the categories based on BMI and FM%, respectively, were used. The children who did not meet these optimal thresholds had a significantly increased risk of being overweight/obese (OR = 2.88, P < 0.01) and risk of having excess fat mass (OR = 2.41, P < 0.01). In conclusion, the decision of selecting among various CoPs significantly influences the optimal levels of MVPA. The Puyau CoP of 3 200 cmp seems to be the most useful for defining the optimal level of PA for pediatric obesity prevention. PMID:27723835

  12. Fluctuation analysis in complex networks modeled by hidden-variable models: Necessity of a large cutoff in hidden-variable models

    NASA Astrophysics Data System (ADS)

    Ostilli, Massimo

    2014-02-01

    It is becoming more and more clear that complex networks present remarkable large fluctuations. These fluctuations may manifest differently according to the given model. In this paper we reconsider hidden-variable models which turn out to be more analytically treatable and for which we have recently shown clear evidence of non-self-averaging, the density of a motif being subject to possible uncontrollable fluctuations in the infinite-size limit. Here we provide full detailed calculations and we show that large fluctuations are only due to the node-hidden variables variability while, in ensembles where these are frozen, fluctuations are negligible in the thermodynamic limit and equal the fluctuations of classical random graphs. A special attention is paid to the choice of the cutoff: We show that in hidden-variable models, only a cutoff growing as Nλ with λ ≥1 can reproduce the scaling of a power-law degree distribution. In turn, it is this large cutoff that generates non-self-averaging.

  13. Return to Work: A Cut-Off of FIM Gain with Montebello Rehabilitation Factor Score in Order to Identify Predictive Factors in Subjects with Acquired Brain Injury

    PubMed Central

    2016-01-01

    Return to work (RTW) for people with acquired brain injury (ABI) represents a main objective of rehabilitation: this work presents a strong correlation between personal well-being and quality of life. The aim of this study is to investigate the prognostic factors that can predict RTW after ABI (traumatic or non- traumatic aetiology) in patients without disorders of consciousness (e.g. coma, vegetative or minimally conscious state) at the beginning of their admission to rehabilitation. At the end of a 6-month follow-up after discharge, data were successfully collected in 69 patients. The rehabilitation effectiveness (functional Recovery) between admission and discharge was assessed by Functional Independent Measure (FIM) gain, through the Montebello Rehabilitation Factor Score (MRFS), which was obtained as follows: (discharge FIM—admission FIM)/(Maximum possible FIM—Admission FIM) x 100. The cut-off value (criterion) deriving from MRFS, which helped identify RTW patients, resulted in .659 (sn 88.9%; sp 52.4%). Considering the Mini Mental State Examination (MMSE) and the MRFS data, the multivariable binary logistic regression analysis presented 62.96% of correct RTW classification cases, 80.95% of non-RTW leading to an overall satisfactory predictability of 73.91%. The results of the present study suggest that occupational therapy intervention could modify cut-off in patients with an MFRS close to target at the end of an in-hospital rehabilitative program thus developing their capabilities and consequently surpassing cut-off itself. PMID:27780215

  14. Return to Work: A Cut-Off of FIM Gain with Montebello Rehabilitation Factor Score in Order to Identify Predictive Factors in Subjects with Acquired Brain Injury.

    PubMed

    Franceschini, Marco; Massimiani, Maria Pia; Paravati, Stefano; Agosti, Maurizio

    2016-01-01

    Return to work (RTW) for people with acquired brain injury (ABI) represents a main objective of rehabilitation: this work presents a strong correlation between personal well-being and quality of life. The aim of this study is to investigate the prognostic factors that can predict RTW after ABI (traumatic or non- traumatic aetiology) in patients without disorders of consciousness (e.g. coma, vegetative or minimally conscious state) at the beginning of their admission to rehabilitation. At the end of a 6-month follow-up after discharge, data were successfully collected in 69 patients. The rehabilitation effectiveness (functional Recovery) between admission and discharge was assessed by Functional Independent Measure (FIM) gain, through the Montebello Rehabilitation Factor Score (MRFS), which was obtained as follows: (discharge FIM-admission FIM)/(Maximum possible FIM-Admission FIM) x 100. The cut-off value (criterion) deriving from MRFS, which helped identify RTW patients, resulted in .659 (sn 88.9%; sp 52.4%). Considering the Mini Mental State Examination (MMSE) and the MRFS data, the multivariable binary logistic regression analysis presented 62.96% of correct RTW classification cases, 80.95% of non-RTW leading to an overall satisfactory predictability of 73.91%. The results of the present study suggest that occupational therapy intervention could modify cut-off in patients with an MFRS close to target at the end of an in-hospital rehabilitative program thus developing their capabilities and consequently surpassing cut-off itself.

  15. Use of cross-reactive serological assays for detecting novel pathogens in wildlife: assessing an appropriate cutoff for henipavirus assays in African bats.

    PubMed

    Peel, Alison J; McKinley, Trevelyan J; Baker, Kate S; Barr, Jennifer A; Crameri, Gary; Hayman, David T S; Feng, Yan-Ru; Broder, Christopher C; Wang, Lin-Fa; Cunningham, Andrew A; Wood, James L N

    2013-11-01

    Reservoir hosts of novel pathogens are often identified or suspected as such on the basis of serological assay results, prior to the isolation of the pathogen itself. Serological assays might therefore be used outside of their original, validated scope in order to infer seroprevalences in reservoir host populations, until such time that specific diagnostic assays can be developed. This is particularly the case in wildlife disease research. The absence of positive and negative control samples and gold standard diagnostic assays presents challenges in determining an appropriate threshold, or 'cutoff', for the assay that enables differentiation between seronegative and seropositive individuals. Here, multiple methods were explored to determine an appropriate cutoff for a multiplexed microsphere assay that is used to detect henipavirus antibody binding in fruit bat plasma. These methods included calculating multiples of 'negative' control assay values, receiver operating characteristic curve analyses, and Bayesian mixture models to assess the distribution of assay outputs for classifying seropositive and seronegative individuals within different age classes. As for any diagnostic assay, the most appropriate cutoff determination method and value selected must be made according to the aims of the study. This study is presented as an example for others where reference samples, and assays that have been characterised previously, are absent.

  16. Cognitive characteristics of children with mathematics learning disability (MLD) vary as a function of the cutoff criterion used to define MLD.

    PubMed

    Murphy, Melissa M; Mazzocco, Michèle M M; Hanich, Laurie B; Early, Martha C

    2007-01-01

    Researchers of mathematics learning disability (MLD) commonly use cutoff scores to determine which participants have MLD. Some researchers apply more restrictive cutoffs than others (e.g., performance below the 10th vs. below the 35th percentile). Different cutoffs may lead to groups of children that differ in their profile of math and related skills, including reading, visual-spatial, and working memory skills. The present study assesses the characteristics of children with MLD based on varying MLD definitions of math performance either below the 10th percentile (n = 22) or between the 11th and 25th percentile (n = 42) on the Test of Early Math Ability, second edition (TEMA-2). Initial starting levels and growth rates for math and related skills were examined in these two MLD groups relative to a comparison group (n = 146) whose TEMA-2 performance exceeded the 25th percentile. Between kindergarten and third grade, differences emerged in the starting level and growth rate, suggesting qualitative differences among the three groups. Despite some similarities, qualitative group differences were also observed in the profiles of math-related skills across groups. These results highlight differences in student characteristics based on the definition of MLD and illustrate the value of examining skill areas associated with math performance in addition to math performance itself.

  17. From meander bend to oxbow lake: flow, channel morphology and sedimentology of an evolving chute cutoff on the Wabash River, IL-IN

    NASA Astrophysics Data System (ADS)

    Zinger, J. A.; Rhoads, B. L.; Best, J. L.; Johnson, K.

    2012-12-01

    Chute channels develop on meandering rivers in a wide variety of environments, and in many cases result in bend cutoff and formation of an oxbow lake. During the transition from active meander bend to oxbow lake, the chute channel and original bend create a paired bifurcation-confluence unit. Here, we present field documentation of the evolving flow structure within a recent chute cutoff on the Wabash River, IL-IN, focusing on the bifurcation located on the upstream limb of the original bend. Previous studies indicate that this is the location of greatest sedimentation rates prior to complete plugging of the bend (e.g. Shields & Abt, 1989). We seek to isolate the fundamental processes causing rapid sedimentation in the upstream limb of the bend, using repeated hydroacoustic measurements of bed elevation and three-dimensional flow velocity at several key cross-sections. We also employ differential GPS surveys of channel banklines, analysis of aerial photographs and sampling of sediment on exposed bars at low flow, to aid interpretations of the cross-sectional data. This paper will detail the co-evolution of flow structure and channel morphology at this site and examine the coherent patterns of erosion and deposition responsible for oxbow lake formation. Reference: Shields, FD; Abt, SR (1989). Sediment deposition in cutoff meander bends and implications for effective management. Regulated Rivers: Research & Management 4, 381-396.

  18. Validation of two age dependent D-dimer cut-off values for exclusion of deep vein thrombosis in suspected elderly patients in primary care: retrospective, cross sectional, diagnostic analysis

    PubMed Central

    Koek, H L (Dineke); Oudega, Ruud; Geersing, Geert-Jan; Janssen, Kristel J M; van Delden, Johannes J M; Moons, Karel G M

    2012-01-01

    Objective To determine whether the use of age adapted D-dimer cut-off values can be translated to primary care patients who are suspected of deep vein thrombosis. Design Retrospective, cross sectional diagnostic study. Setting 110 primary care doctors affiliated with three hospitals in the Netherlands. Participants 1374 consecutive patients (936 (68.1%) aged >50 years) with clinically suspected deep vein thrombosis. Main outcome measures Proportion of patients with D-dimer values below two proposed age adapted cut-off levels (age in years×10 μg/L in patients aged >50 years, or 750 μg/L in patients aged ≥60 years), in whom deep vein thrombosis could be excluded; and the number of false negative results. Results Using the Wells score, 647 patients had an unlikely clinical probability of deep vein thrombosis. In these patients (at all ages), deep vein thrombosis could be excluded in 309 (47.8%) using the age dependent cut-off value compared with 272 (42.0%) using the conventional cut-off value of 500 μg/L (increase 5.7%, 95% confidence interval 4.1% to 7.8%). This exclusion rate resulted in 0.5% and 0.3% false negative cases, respectively (increase 0.2%, 0.004% to 8.6%).The increase in exclusion rate by using the age dependent cut-off value was highest in the oldest patients. In patients older than 80 years, deep vein thrombosis could be safely excluded in 22 (35.5%) patients using the age dependent cut-off value compared with 13 (21.0%) using the conventional cut-off value (increase 14.5%, 6.8% to 25.8%). Compared with the age dependent cut-off value, the cut-off value of 750 μg/L had a similar exclusion rate (307 (47.4%) patients) and false negative rate (0.3%). Conclusions Combined with a low clinical probability of deep vein thrombosis, use of the age dependent D-dimer cut-off value for patients older than 50 years or the cut-off value of 750 μg/L for patients aged 60 years and older resulted in a considerable increase in the proportion of patients in

  19. The Use of Innovative Two-Component Cluster Analysis and Serodiagnostic Cut-Off Methods to Estimate Prevalence of Pertussis Reinfections

    PubMed Central

    van Twillert, Inonge; Bonačić Marinović, Axel A.; van Gaans-van den Brink, Jacqueline A. M.; Kuipers, Betsy; Berbers, Guy A. M.; van der Maas, Nicoline A. T.; Verheij, Theo J. M.; Versteegh, Florens G. A.; Teunis, Peter F. M.; van Els, Cécile A. C. M.

    2016-01-01

    Bordetella pertussis circulates even in highly vaccinated countries affecting all age groups. Insight into the scale of concealed reinfections is important as they may contribute to transmission. We therefore investigated whether current single-point serodiagnostic methods are suitable to estimate the prevalence of pertussis reinfection. Two methods based on IgG-Ptx plasma levels alone were used to evaluate the proportion of renewed seroconversions in the past year in a cohort of retrospective pertussis cases ≥ 24 months after a proven earlier symptomatic infection. A Dutch population database was used as a baseline. Applying a classical 62.5 IU/ml IgG-Ptx cut-off, we calculated a seroprevalence of 15% in retrospective cases, higher than the 10% observed in the population baseline. However, this method could not discriminate between renewed seroconversion and waning of previously infection-enhanced IgG-Ptx levels. Two-component cluster analysis of the IgG-Ptx datasets of both pertussis cases and the general population revealed a continuum of intermediate IgG-Ptx levels, preventing the establishment of a positive population and the comparison of prevalence by this alternative method. Next, we investigated the complementary serodiagnostic value of IgA-Ptx levels. When modelling datasets including both convalescent and retrospective cases we obtained new cut-offs for both IgG-Ptx and IgA-Ptx that were optimized to evaluate renewed seroconversions in the ex-cases target population. Combining these cut-offs two-dimensionally, we calculated 8.0% reinfections in retrospective cases, being below the baseline seroprevalence. Our study for the first time revealed the shortcomings of using only IgG-Ptx data in conventional serodiagnostic methods to determine pertussis reinfections. Improved results can be obtained with two-dimensional serodiagnostic profiling. The proportion of reinfections thus established suggests a relatively increased period of protection to renewed

  20. The Use of Innovative Two-Component Cluster Analysis and Serodiagnostic Cut-Off Methods to Estimate Prevalence of Pertussis Reinfections.

    PubMed

    van Twillert, Inonge; Bonačić Marinović, Axel A; van Gaans-van den Brink, Jacqueline A M; Kuipers, Betsy; Berbers, Guy A M; van der Maas, Nicoline A T; Verheij, Theo J M; Versteegh, Florens G A; Teunis, Peter F M; van Els, Cécile A C M

    2016-01-01

    Bordetella pertussis circulates even in highly vaccinated countries affecting all age groups. Insight into the scale of concealed reinfections is important as they may contribute to transmission. We therefore investigated whether current single-point serodiagnostic methods are suitable to estimate the prevalence of pertussis reinfection. Two methods based on IgG-Ptx plasma levels alone were used to evaluate the proportion of renewed seroconversions in the past year in a cohort of retrospective pertussis cases ≥ 24 months after a proven earlier symptomatic infection. A Dutch population database was used as a baseline. Applying a classical 62.5 IU/ml IgG-Ptx cut-off, we calculated a seroprevalence of 15% in retrospective cases, higher than the 10% observed in the population baseline. However, this method could not discriminate between renewed seroconversion and waning of previously infection-enhanced IgG-Ptx levels. Two-component cluster analysis of the IgG-Ptx datasets of both pertussis cases and the general population revealed a continuum of intermediate IgG-Ptx levels, preventing the establishment of a positive population and the comparison of prevalence by this alternative method. Next, we investigated the complementary serodiagnostic value of IgA-Ptx levels. When modelling datasets including both convalescent and retrospective cases we obtained new cut-offs for both IgG-Ptx and IgA-Ptx that were optimized to evaluate renewed seroconversions in the ex-cases target population. Combining these cut-offs two-dimensionally, we calculated 8.0% reinfections in retrospective cases, being below the baseline seroprevalence. Our study for the first time revealed the shortcomings of using only IgG-Ptx data in conventional serodiagnostic methods to determine pertussis reinfections. Improved results can be obtained with two-dimensional serodiagnostic profiling. The proportion of reinfections thus established suggests a relatively increased period of protection to renewed

  1. Using a 3% Proton Density Fat Fraction as a Cut-off Value Increases Sensitivity of Detection of Hepatic Steatosis, Based on Results from Histopathology Analysis.

    PubMed

    Nasr, Patrik; Forsgren, Mikael F; Ignatova, Simone; Dahlström, Nils; Cedersund, Gunnar; Leinhard, Olof Dahlqvist; Norén, Bengt; Ekstedt, Mattias; Lundberg, Peter; Kechagias, Stergios

    2017-03-09

    It is possible to estimate hepatic triglyceride content by calculating the proton density fat fraction (PDFF), using proton magnetic resonance spectroscopy ((1)H-MRS), instead of collecting and analyzing liver biopsies to detect steatosis. However, the current PDFF cut-off value (5%) used to define steatosis by magnetic resonance was derived from studies that did not use histopathology as the reference standard. We performed a prospective study to determine the accuracy of (1)H-MRS PDFF in measurement of steatosis using histopathology analysis as the standard. We collected clinical, serologic, (1)H-MRS PDFF, and liver biopsy data from 94 adult patients with increased levels of liver enzymes (6 months or more) referred to the Department of Gastroenterology and Hepatology at Linköping University Hospital in Sweden from 2007 through 2014. Steatosis was graded using the conventional histopathology method and fat content was quantified in biopsy samples using stereological point counts (SPCs). We correlated (1)H-MRS PDFF findings with SPCs (r = 0.92; P <.001). (1)H-MRS PDFF results correlated with histopathology results (ρ = 0.87; P <.001), and SPCs correlated with histopathology results (ρ = 0.88; P <.001). All 25 subjects with PDFF values of 5.0% or more had steatosis based on histopathology findings (100% specificity for PDFF). However, of 69 subjects with PDFF values below 5.0% (negative result), 22 were determined to have steatosis based on histopathology findings (53% sensitivity for PDFF). Reducing the PDFF cut-off value to 3.0% identified patients with steatosis with 100% specificity and 79% sensitivity; a PDFF cut-off value of 2.0% identified patients with steatosis with 94% specificity and 87% sensitivity. These findings might be used to improve non-invasive detection of steatosis.

  2. Usefulness and limitations of QuantiFERON-TB Gold in Japanese rheumatoid arthritis patients: proposal to decrease the lower cutoff level for assessing latent tuberculosis infection.

    PubMed

    Maeda, Tomoyo; Banno, Shogo; Maeda, Shinji; Naniwa, Taio; Hayami, Yoshihito; Watanabe, Maiko; Itoh, Rei; Sato, Shigeki; Ueda, Ryuzo

    2010-02-01

    We aimed to determine the sensitivity and specificity of QuantiFERON-TB Gold (QFT-G) in Japanese rheumatoid arthritis (RA) patients with a past history of tuberculosis (TB). We assessed whether it is possible to decrease the cutoff using receiver operating characteristic (ROC) analysis. We evaluated chest computed tomography (CT) findings, prior history of treatment, and contact with active TB in 370 RA patients. Forty-nine patients before initiation of treatment with tumor necrosis factor (TNF) inhibitors were divided into two groups: 22 with a past history of TB and 27 without. We estimated the efficacy of QFT-G compared with the tuberculin skin test and antituberculosis (anti-TB) glycolipid antigen antibody. QFT-G was positive (>or=0.35 IU/ml) in 13.6% with a past history of TB, increasing to 27.3% at the intermediate range cutoff of 0.1 IU/ml. The sensitivity and specificity of QFT-G was 0.27 and 1.00, respectively, at 0.1 IU/ml. Using ROC analysis, the area under the curve (AUC) of QFT-G but not for the other two tests was significantly large. QFT-G is a useful diagnostic method due to its superior specificity, but the use of a cutoff value of 0.35 IU/ml will likely result in an underestimate. We propose that a lower interferon-gamma (IFN-gamma) titer of 0.1 IU/ml be adopted when deciding to administer anti-TB drugs before initiation of TNF inhibitors.

  3. Insulin resistance (HOMA-IR) cut-off values and the metabolic syndrome in a general adult population: effect of gender and age: EPIRCE cross-sectional study

    PubMed Central

    2013-01-01

    Background Insulin resistance has been associated with metabolic and hemodynamic alterations and higher cardio metabolic risk. There is great variability in the threshold homeostasis model assessment of insulin resistance (HOMA-IR) levels to define insulin resistance. The purpose of this study was to describe the influence of age and gender in the estimation of HOMA-IR optimal cut-off values to identify subjects with higher cardio metabolic risk in a general adult population. Methods It included 2459 adults (range 20–92 years, 58.4% women) in a random Spanish population sample. As an accurate indicator of cardio metabolic risk, Metabolic Syndrome (MetS), both by International Diabetes Federation criteria and by Adult Treatment Panel III criteria, were used. The effect of age was analyzed in individuals with and without diabetes mellitus separately. ROC regression methodology was used to evaluate the effect of age on HOMA-IR performance in classifying cardio metabolic risk. Results In Spanish population the threshold value of HOMA-IR drops from 3.46 using 90th percentile criteria to 2.05 taking into account of MetS components. In non-diabetic women, but no in men, we found a significant non-linear effect of age on the accuracy of HOMA-IR. In non-diabetic men, the cut-off values were 1.85. All values are between 70th-75th percentiles of HOMA-IR levels in adult Spanish population. Conclusions The consideration of the cardio metabolic risk to establish the cut-off points of HOMA-IR, to define insulin resistance instead of using a percentile of the population distribution, would increase its clinical utility in identifying those patients in whom the presence of multiple metabolic risk factors imparts an increased metabolic and cardiovascular risk. The threshold levels must be modified by age in non-diabetic women. PMID:24131857

  4. Energy-averaged electron-ion momentum transport cross section in the Born approximation and Debye-Hückel potential: Comparison with the cut-off theory

    NASA Astrophysics Data System (ADS)

    Zaghloul, Mofreh R.; Bourham, Mohamed A.; Doster, J. Michael

    2000-04-01

    An exact analytical expression for the energy-averaged electron-ion momentum transport cross section in the Born approximation and Debye-Hückel exponentially screened potential has been derived and compared with the formulae given by other authors. A quantitative comparison between cut-off theory and quantum mechanical perturbation theory has been presented. Based on results from the Born approximation and Spitzer's formula, a new approximate formula for the quantum Coulomb logarithm has been derived and shown to be more accurate than previous expressions.

  5. Energy-averaged electron-ion momentum transport cross section in the Born Approximation and Debye-Hückel potential: Comparison with the cut-off theory

    NASA Astrophysics Data System (ADS)

    Zaghloul, Mofreh R.; Bourham, Mohamed A.; Doster, J. Michael

    2000-02-01

    An exact analytical expression for the energy-averaged electron-ion momentum transport cross section in the Born approximation and Debye-Hückel exponentially screened potential has been derived and compared with the formulae given by other authors. A quantitative comparison between cut-off theory and quantum mechanical perturbation theory has been presented. Based on results from the Born approximation and Spitzer's formula, a new approximate formula for the quantum Coulomb logarithm has been derived and shown to be more accurate than previous expressions.

  6. Resonant and Nonresonant Electron Cyclotron Heating at Densities above the Plasma Cutoff by O-X-B Mode Conversion at the W7-As Stellarator

    SciTech Connect

    Laqua, H.; Erckmann, V.; Hartfuss, H.; Laqua, H.; ECRH Group, W.T.

    1997-05-01

    The extension of the experimentally accessible plasma densities with electron cyclotron heating beyond the plasma cutoff density and the removal of the restriction to a resonant magnetic field, both via mode conversion heating from an O-wave to an X-wave and, finally, to an electron Bernstein (O-X-B) wave, was investigated and successfully demonstrated at the W7-AS stellarator. In addition to the heating effect, clear evidence for both mode conversion steps was detected for the first time. {copyright} {ital 1997} {ital The American Physical Society}

  7. A preliminary evaluation of the occurrence and characteristics of cut-off ponds of the Maryland shores of the Chesapeake Bay

    SciTech Connect

    Not Available

    1980-10-01

    Under the auspices of the Maryland Power Plant Siting Program, a preliminary investigation of occurrence and characteristics of cut-off ponds in the Maryland portion of the Chesapeake Bay was conducted. These small ponds occur commonly along the Bay shore. A sand berm separates the freshwaters of the ponds from the saline waters of the Bay; this berm is occasionally breached permitting interchange between ponds and Bay. A survey of aerial maps and photographs has revealed approximately 1800 ponds bordering the mid and upper Bay.

  8. Vapor space characterization of waste tank 241-BX-104: Results from samples collected on 12/30/94

    SciTech Connect

    Pool, K.H.; Ligotke, M.W.; McVeety, B.D.

    1995-10-01

    This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-BX-104 (referred to as Tank BX-104). The results described here were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained. for the inorganic compounds ammonia (NH{sub 3}), nitrogen dioxide (NO{sub 2}), nitric oxide (NO), and water (H{sub 2}O). Sampling for hydrogen cyanide (HCN) and sulfur oxides (SOx) was not requested. In addition, quantitative results were obtained for the 39 TO-14 compounds plus an additional 14 analytes. Of these, 13 were observed above the 5-ppbv reporting cutoff. Sixty-six organic tentatively identified compounds (TICs) were observed above the reporting cutoff of (ca.) 10 ppbv and are reported with concentrations that are semiquantitative estimates based on internal-standard response factors. The 10 organic analytes, with the highest estimated concentrations are listed in Table 1 and account for approximately 70% of the total organic components in Tank BX-104. Two permanent gases, carbon dioxide (CO{sub 2}) and nitrous oxide (N{sub 2}O), were also detected.

  9. Vapor space characterization of waste Tank 241-U-103: Results from samples collected on 2/15/95

    SciTech Connect

    Ligotke, M.W.; Pool, K.H.; Clauss, T.W.; McVeety, B.D.; Klinger, G.S.; Olsen, K.B.; Bredt, O.P.; Fruchter, J.S.; Goheen, S.C.

    1995-11-01

    This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-U-103 (referred to as Tank U-103). The results described her were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH{sub 3}), nitrogen dioxide (NO{sub 2}), nitric oxide (NO), and water vapor (H{sub 2}O). Sampling for hydrogen cyanide (HCN) and sulfur oxides (SO{sub x}) was not requested. In addition, quantitative results were obtained for the 39 TO-14 compounds plus an additional 14 analytes. Of these, 11 were observed above the 5-ppbv reporting cutoff. Eleven tentatively identified compounds (TICs) were observed above the reporting cutoff of (ca.) 10 ppbv and are reported with concentrations that are semiquantitative estimates based on internal-standard response factors. The 10 organic analytes with the highest estimated concentrations are listed in Table 1 and account for approximately 90% of the total organic components in Tank U-103. Two permanent gases, hydrogen (H{sub 2}) and nitrous oxide (N{sub 2}O), were also detected. Tank U-103 is on the Hydrogen Watch List.

  10. Vapor space characterization of waste Tank 241-B-103: Results from samples collected on 2/8/95

    SciTech Connect

    Ligotke, M.W.; Pool, K.H.; Lucke, R.B.

    1995-10-01

    This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-B-103 (referred to as Tank B-103). The results described here were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH{sub 3}), nitrogen dioxide (NO{sub 2}), nitric oxide (NO), and water vapor (H{sub 2}O). Sampling for hydrogen cyanide (HCN) and sulfur oxides (SO{sub x}) was not requested. In addition, quantitative results were obtained for the 39 TO-14 compounds plus an additional 14 analytes. Of these, five were observed above the 5-ppbv reporting cutoff. Twenty-six organic tentatively identified compounds (TICs) were observed above the reporting cutoff of (ca.) 10 ppbv, and are reported with concentrations that are semiquantitative estimates based on internal standard response factors. Twenty-three TICs were measured in two or more SUMMA{trademark} canisters. The 10 organic analytes with the highest estimated concentrations are listed in Table 1 and account for approximately 66% of the total organic components in Tank BB-103. Two permanent gases, carbon dioxide (CO{sub 2}) and nitrous oxide (N{sub 2}O), were also detected. Tank B-103 is on the Organic Watch List.

  11. Vapor space characterization of waste Tank 241-SX-103: Results from samples collected on 3/23/95

    SciTech Connect

    Ligotke, M.W.; Clauss, T.W.; Pool, K.H.; McVeety, B.D.; Klinger, G.S.; Olsen, K.B.; Bredt, O.P.; Fruchter, J.S.; Goheen, S.C.

    1995-11-01

    This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage tank 241-SX-103 (referred to as Tank SX-103). The results described here were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH{sub 3}), nitrogen dioxide (NO{sub 2}), nitric oxide (NO), and water vapor (H{sub 2}O). Sampling for hydrogen cyanide (HCN) and sulfur oxides (SO{sub x}) was not requested. In addition, quantitative results were obtained for the 39 TO-14 compounds plus an additional 14 analytes. Of these, two were observed above the 5-ppbv reporting cutoff. Two tentatively identified compounds (TICs) were observed above the reporting cutoff of (ca.) 10 ppbv and are reported with concentrations that are semiquantitative estimates based on internal-standard response factors. The four organic analytes identified are listed in Table 1 and account for approximately 100% of the total organic components in Tank SX-103. Carbon dioxide (CO{sub 2}) was the only permanent gas detected in the tank-headspace samples. Tank SX-103 is on the Hydrogen Watch List.

  12. Vapor space characterization of waste Tank 241-BY-108: Results from samples collected on 10/27/94

    SciTech Connect

    McVeety, B.D.; Clauss, T.W.; Ligotke, M.W.

    1995-10-01

    This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-BY-108 (referred to as Tank BY-108). The results described here were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH{sub 3}), nitrogen dioxide (NO{sub 2}), nitric oxide (NO), and water vapor (H{sub 2}O). Trends in NH{sub 3} and H{sub 2}O samples indicated a possible sampling problem. Sampling for hydrogen cyanide (HCN) and sulfur oxides (SO{sub x}) was not requested. In addition, the authors looked for the 40 TO-14 compounds plus an additional 15 analytes. Of these, 17 were observed above the 5-ppbv reporting cutoff. Also, eighty-one organic tentatively identified compounds (TICs) were observed above the reporting cutoff (ca.) 10 ppbv, and are reported with concentrations that are semiquantitative estimates based on internal standard response factors. The nine organic analytes with the highest estimated concentrations are listed in Summary Table 1 and account for approximately 48% of the total organic components in the headspace of Tank BY-108. Three permanent gases, hydrogen (H{sub 2}), carbon dioxide (CO{sub 2}), and nitrous oxide (N{sub 2}O) were also detected. Tank BY-108 is on the Ferrocyanide Watch List.

  13. Vapor space characterization of waste tank 241-BY-110: Results for samples collected on 11/11/94

    SciTech Connect

    Clauss, T.W.; Ligotke, M.W.; Pool, K.H.

    1995-06-01

    This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-BY-110 (referred to as Tank BY-110). The results described here were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH{sub 3}), nitrogen dioxide (NO{sub 2}, nitric oxide (NO), and water (H{sub 2}O). Sampling for hydrogen cyanide (HCN) and sulfur oxides (SO{sub x}) was not requested. In addition, we looked for the 40 TO-14 compounds plus an additional 15 analytes. Of these, 10 were observed above the 5-ppbv reporting cutoff. Forty-six organic tentatively identified compounds (TICS) were observed above the reporting cutoff of (ca.) 10 ppbv, and are reported with concentrations that are semiquantative estimates based on internal standard response factors. The 10 organic analytes with the highest estimated concentrations are listed and account for approximately 78% of the total organic components in Tank BY-110. Two permanent gases, carbon dioxide (CO{sub 2}) and nitrous oxide (N{sub 2}O), were also detected.

  14. One strategy to enhance electrochemical properties of Ni-based cathode materials under high cut-off voltage for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Liang, Longwei; Jiang, Feng; Cao, Yanbing; Hu, Guorong; Du, Ke; Peng, Zhongdong

    2016-10-01

    Well-distributed, nano-sized and amorphous or crystalized NaTi2(PO4)3 (NTP) coating layer with high ionic conductivity is successfully introduced onto the surface of LiNi0.6Co0.2Mn0.2O2 (LNCM) particles by a simple and effective mechanical activation method followed by adjusting the reheating temperature appropriately. The promoting influence of NTP coating on the structure stability, cycle life and high rate capability under elevated cut-off voltage has been investigated in-depth. Particularly for the crystalized NTP-coated LNCM, the main reason for the enhanced electrochemical performance can be attributed to the NTP layer with rhombohedral structure providing convenient and low activation barrier diffusion pathways for Li+ ions to insert/extract the interface of electrode/electrolyte. Besides, the NTP-coated layer with stable structure can effectively inhibit the surface side reaction during the long charge/discharge process under high cut-off voltage, which will reduce the harmful insulative by-products. It's worth mentioning that the cyclic stability of crystalized NTP-coated LNCM between 3.0 and 4.6 V is also improved significantly even under the rigorous test environment.

  15. Triceps and Subscapular Skinfold Thickness Percentiles and Cut-Offs for Overweight and Obesity in a Population-Based Sample of Schoolchildren and Adolescents in Bogota, Colombia

    PubMed Central

    Ramírez-Vélez, Robinson; López-Cifuentes, Mario Ferney; Correa-Bautista, Jorge Enrique; González-Ruíz, Katherine; González-Jiménez, Emilio; Córdoba-Rodríguez, Diana Paola; Vivas, Andrés; Triana-Reina, Hector Reynaldo; Schmidt-RioValle, Jacqueline

    2016-01-01

    The assessment of skinfold thickness is an objective measure of adiposity. The aims of this study were to establish Colombian smoothed centile charts and LMS L (Box–Cox transformation), M (median), and S (coefficient of variation) tables for triceps, subscapular, and triceps + subscapular skinfolds; appropriate cut-offs were selected using receiver operating characteristic (ROC) analysis based on a population-based sample of children and adolescents in Bogotá, Colombia. A cross-sectional study was conducted in 9618 children and adolescents (55.7% girls; age range of 9–17.9 years). Triceps and subscapular skinfold measurements were obtained using standardized methods. We calculated the triceps + subscapular skinfold (T + SS) sum. Smoothed percentile curves for triceps and subscapular skinfold thickness were derived using the LMS method. ROC curve analyses were used to evaluate the optimal cut-off point of skinfold thickness for overweight and obesity, based on the International Obesity Task Force definitions. Subscapular and triceps skinfolds and T + SS were significantly higher in girls than in boys (p < 0.001). The ROC analysis showed that subscapular and triceps skinfolds and T + SS have a high discriminatory power in the identification of overweight and obesity in the sample population in this study. Our results provide sex- and age-specific normative reference standards for skinfold thickness values from a population from Bogotá, Colombia. PMID:27669294

  16. Increased impedance near cut-off in plasma-like media leading to emission of high-power, narrow-bandwidth radiation

    PubMed Central

    Hur, M. S.; Ersfeld, B.; Noble, A.; Suk, H.; Jaroszynski, D. A.

    2017-01-01

    Ultra-intense, narrow-bandwidth, electromagnetic pulses have become important tools for exploring the characteristics of matter. Modern tuneable high-power light sources, such as free-electron lasers and vacuum tubes, rely on bunching of relativistic or near-relativistic electrons in vacuum. Here we present a fundamentally different method for producing narrow-bandwidth radiation from a broad spectral bandwidth current source, which takes advantage of the inflated radiation impedance close to cut-off in a medium with a plasma-like permittivity. We find that by embedding a current source in this cut-off region, more than an order of magnitude enhancement of the radiation intensity is obtained compared with emission directly into free space. The method suggests a simple and general way to flexibly use broadband current sources to produce broad or narrow bandwidth pulses. As an example, we demonstrate, using particle-in-cell simulations, enhanced monochromatic emission of terahertz radiation using a two-colour pumped current source enclosed by a tapered waveguide. PMID:28071681

  17. Triceps and Subscapular Skinfold Thickness Percentiles and Cut-Offs for Overweight and Obesity in a Population-Based Sample of Schoolchildren and Adolescents in Bogota, Colombia.

    PubMed

    Ramírez-Vélez, Robinson; López-Cifuentes, Mario Ferney; Correa-Bautista, Jorge Enrique; González-Ruíz, Katherine; González-Jiménez, Emilio; Córdoba-Rodríguez, Diana Paola; Vivas, Andrés; Triana-Reina, Hector Reynaldo; Schmidt-RioValle, Jacqueline

    2016-09-24

    The assessment of skinfold thickness is an objective measure of adiposity. The aims of this study were to establish Colombian smoothed centile charts and LMS L (Box-Cox transformation), M (median), and S (coefficient of variation) tables for triceps, subscapular, and triceps + subscapular skinfolds; appropriate cut-offs were selected using receiver operating characteristic (ROC) analysis based on a population-based sample of children and adolescents in Bogotá, Colombia. A cross-sectional study was conducted in 9618 children and adolescents (55.7% girls; age range of 9-17.9 years). Triceps and subscapular skinfold measurements were obtained using standardized methods. We calculated the triceps + subscapular skinfold (T + SS) sum. Smoothed percentile curves for triceps and subscapular skinfold thickness were derived using the LMS method. ROC curve analyses were used to evaluate the optimal cut-off point of skinfold thickness for overweight and obesity, based on the International Obesity Task Force definitions. Subscapular and triceps skinfolds and T + SS were significantly higher in girls than in boys (p < 0.001). The ROC analysis showed that subscapular and triceps skinfolds and T + SS have a high discriminatory power in the identification of overweight and obesity in the sample population in this study. Our results provide sex- and age-specific normative reference standards for skinfold thickness values from a population from Bogotá, Colombia.

  18. Increased impedance near cut-off in plasma-like media leading to emission of high-power, narrow-bandwidth radiation

    NASA Astrophysics Data System (ADS)

    Hur, M. S.; Ersfeld, B.; Noble, A.; Suk, H.; Jaroszynski, D. A.

    2017-01-01

    Ultra-intense, narrow-bandwidth, electromagnetic pulses have become important tools for exploring the characteristics of matter. Modern tuneable high-power light sources, such as free-electron lasers and vacuum tubes, rely on bunching of relativistic or near-relativistic electrons in vacuum. Here we present a fundamentally different method for producing narrow-bandwidth radiation from a broad spectral bandwidth current source, which takes advantage of the inflated radiation impedance close to cut-off in a medium with a plasma-like permittivity. We find that by embedding a current source in this cut-off region, more than an order of magnitude enhancement of the radiation intensity is obtained compared with emission directly into free space. The method suggests a simple and general way to flexibly use broadband current sources to produce broad or narrow bandwidth pulses. As an example, we demonstrate, using particle-in-cell simulations, enhanced monochromatic emission of terahertz radiation using a two-colour pumped current source enclosed by a tapered waveguide.

  19. Rocking at 81 and Rolling at 34: ROC Cut-Off Scores for the Negative Acts Questionnaire–Revised in Serbia

    PubMed Central

    Petrović, Ivana B.; Vukelić, Milica; Čizmić, Svetlana

    2017-01-01

    Researchers are still searching for the ways to identify different categories of employees according to their exposure to negative acts and psychological experience of workplace bullying. We followed Notelaers and Einarsen’s application of the ROC analysis to determine the NAQ-R cut-off scores applying a “lower” and “higher” threshold. The main goal of this research was to develop and test different gold standards of personal and organizational relevance in determining the NAQ-R cut-off scores in a specific cultural and economic context of Serbia. Apart from combining self-labeling as a victim with self-perceived health, the objectives were to test the gold standards developed as a combination of self-labeling with life satisfaction, self-labeling with intention to leave and a complex gold standard based on self-labeling, self-perceived health, life satisfaction and intention to leave taken together. The ROC analysis on Serbian workforce data supports applying of different gold standards. For identifying employees in a preliminary stage of bullying, the most applicable was the gold standard based on self-labeling and intention to leave (score 34 and higher). The most accurate identification of victims could be based on the most complex gold standard (score 81 and higher). This research encourages further investigation of gold standards in different cultures. PMID:28119652

  20. Influence of the Lift-Off Effect on the Cut-Off Frequency of the EMAT-Generated Rayleigh Wave Signal

    PubMed Central

    Yi, Pengxing; Zhang, Kang; Li, Yahui; Zhang, Xuming

    2014-01-01

    The electromagnetic acoustic transducer (EMAT), a non-contact NDT tool with large lift-off, is becoming an attractive method for detecting the cracks in the metal parts. However, the lift-off of the transducer has a direct effect on the feature that is used to characterize the defects. A detailed investigation on the relationship between the feature and the lift-off of the EMAT is crucial in the detection process. This paper investigates the lift-off effect on the feature, cut-off frequency of EMAT in the Rayleigh wave. The study can be divided into two parts. Firstly, with a multi-field coupling environment, 2-D electromagnetic and wave generation EMAT models are built to simulate the interaction of the Rayleigh wave with the surface crack. Then, the lift-off effect on the cut-off frequency is investigated through simulation and experiment. Compared to the previous studies, it is found that lift-off would cause a negative result when the lift-off varies in the testing process. Besides, the calibration obtained from the tests at a random lift-off value can be used in other tests with any different lift off value provided that the lift-off is kept as a constant during the detection process. PMID:25340446