Threshold resummation for slepton-pair production at hadron colliders

International Nuclear Information System (INIS)

Bozzi, Giuseppe; Fuks, Benjamin; Klasen, Michael

2007-01-01

We present a first and extensive study of threshold resummation effects for supersymmetric (SUSY) particle production at hadron colliders, focusing on Drell-Yan like slepton-pair and slepton-sneutrino associated production. After confirming the known next-to-leading order (NLO) QCD corrections and generalizing the NLO SUSY-QCD corrections to the case of mixing squarks in the virtual loop contributions, we employ the usual Mellin N-space resummation formalism with the minimal prescription for the inverse Mellin-transform and improve it by resumming 1/N-suppressed and a class of N-independent universal contributions. Numerically, our results increase the theoretical cross sections by 5 to 15% with respect to the NLO predictions and stabilize them by reducing the scale dependence from up to 20% at NLO to less than 10% with threshold resummation

Threshold resummation for slepton-pair production at hadron colliders

International Nuclear Information System (INIS)

Bozzi, Giuseppe; Fuks, Benjamin; Klasen, Michael

2007-01-01

We present a first and extensive study of threshold resummation effects for supersymmetric (SUSY) particle production at hadron colliders, focusing on Drell-Yan like slepton-pair and slepton-sneutrino associated production. After confirming the known next-to-leading order (NLO) QCD corrections and generalizing the NLO SUSY-QCD corrections to the case of mixing squarks in the virtual loop contributions, we employ the usual Mellin N-space resummation formalism with the minimal prescription for the inverse Mellin-transform and improve it by re-summing 1/N-suppressed and a class of N-independent universal contributions. Numerically, our results increase the theoretical cross sections by 5 to 15% with respect to the NLO predictions and stabilize them by reducing the scale dependence from up to 20% at NLO to less than 10% with threshold resummation. (authors)

Measurement of inclusive eta production in e+e- interactions near charm threshold

International Nuclear Information System (INIS)

Partridge, R.; Peck, C.; Porter, F.C.; Gu, Y.F.; Kollmann, W.; Richardson, M.; Strauch, K.; Wacker, K.; Aschman, D.; Bagger, J.; Burnett, T.; Cavalli-Sforza, M.; Coyne, D.; Joy, M.; Sadrozinski, H.F.W.; Hofstadter, R.; Horisberger, R.; Kirkbride, I.; Kolanoski, H.; Koenigsmann, K.; Liberman, A.; O'Reilly, J.; Osterheld, A.; Tompkins, J.; Bloom, E.; Bulos, F.; Chestnut, R.; Gaiser, J.; Godfrey, G.; Kiesling, C.; Lockman, W.; Oreglia, M.

1981-01-01

We have measured the inclusive cross section for eta production in e + e - interactions near charm threshold using the Crystal Ball detector. No pronounced structure in the energy dependence is observed. By comparing cross sections above and below charm threshold we obtain the limits (90% confidence limit): R(e + e - →FF-barX)Br(F→etax) <0.15--0.32 (for E/sub c.m./ from 4.0 to 4.5 GeV), Br(D→etax)<0.13 [averaged over charged and neutral D components of the psi''(3770) decays]. Our results are inconsistent with a previous report of a large energy dependence of the eta cross section ascribed to the crossing the FF* and F*F* production thresholds

Temperature-dependence of Threshold Current Density-Length Product in Metallization Lines: A Revisit

International Nuclear Information System (INIS)

Duryat, Rahmat Saptono; Kim, Choong-Un

2016-01-01

One of the important phenomena in Electromigration (EM) is Blech Effect. The existence of Threshold Current Density-Length Product or EM Threshold has such fundamental and technological consequences in the design, manufacture, and testing of electronics. Temperature-dependence of Blech Product had been thermodynamically established and the real behavior of such interconnect materials have been extensively studied. The present paper reviewed the temperature-dependence of EM threshold in metallization lines of different materials and structure as found in relevant published articles. It is expected that the reader can see a big picture from the compiled data, which might be overlooked when it was examined in pieces. (paper)

Associated strangeness production in pp collisions near threshold

International Nuclear Information System (INIS)

Winter, P.

2004-01-01

Motivated by the ongoing discussion concerning the nature of the scalar resonances f0(980) and a0(980), the COSY-11 collaboration has taken exclusive data on the pp → ppK+K- reaction near the production threshold. A first total cross section σ = (1.80 ± 0.27 -0.35 +0.28 ) nb for the excess energy Q = 17 MeV has been determined. In contrary to the η, ω, and η' single meson production studies which clearly show the strong pp final state interaction (FSI), the cross section values obtained at COSY-11 and DISTO can be both described by a fit with a four-body phase space including the proton-proton final state interaction as well as with one-meson exchange calculations neglecting FSI effects. Therefore, one might think about a compensation of the strong pp interaction through a pK-FSI effect or an additional degree of freedom caused by the four-body final state. In the latter case, strong FSI effects can be expected at Q-values very close to the K+K- production threshold. Such a motivation triggered - in combination with the investigation of the KK-bar interaction being relevant to the structure of the f0 (980) - further measurements at the excess energies Q = 10 and Q 28 MeV at COSY-11

Measurement of inclusive eta production in e+e- interactions near charm threshold

International Nuclear Information System (INIS)

Porter, F.C.

1980-08-01

The inclusive cross section for eta production in e + e - interactions near charm threshold was measured by use of the Crystal Ball detector at SPEAR. By comparison of the inclusive eta production above and below charm threshold the following limits were obtained: R(e + e - → F anti FX)BR(F → eta x) < 0.3 (90% C.L., E/sub cm/ < 4.5 GeV); BR(D → eta x) < 0.13 (90% C.L., averaged over charged and neutral D components of the psi''). 4 figures, 1 table

Validation and evaluation of epistemic uncertainty in rainfall thresholds for regional scale landslide forecasting

Science.gov (United States)

Gariano, Stefano Luigi; Brunetti, Maria Teresa; Iovine, Giulio; Melillo, Massimo; Peruccacci, Silvia; Terranova, Oreste Giuseppe; Vennari, Carmela; Guzzetti, Fausto

2015-04-01

Prediction of rainfall-induced landslides can rely on empirical rainfall thresholds. These are obtained from the analysis of past rainfall events that have (or have not) resulted in slope failures. Accurate prediction requires reliable thresholds, which need to be validated before their use in operational landslide warning systems. Despite the clear relevance of validation, only a few studies have addressed the problem, and have proposed and tested robust validation procedures. We propose a validation procedure that allows for the definition of optimal thresholds for early warning purposes. The validation is based on contingency table, skill scores, and receiver operating characteristic (ROC) analysis. To establish the optimal threshold, which maximizes the correct landslide predictions and minimizes the incorrect predictions, we propose an index that results from the linear combination of three weighted skill scores. Selection of the optimal threshold depends on the scope and the operational characteristics of the early warning system. The choice is made by selecting appropriately the weights, and by searching for the optimal (maximum) value of the index. We discuss weakness in the validation procedure caused by the inherent lack of information (epistemic uncertainty) on landslide occurrence typical of large study areas. When working at the regional scale, landslides may have occurred and may have not been reported. This results in biases and variations in the contingencies and the skill scores. We introduce two parameters to represent the unknown proportion of rainfall events (above and below the threshold) for which landslides occurred and went unreported. We show that even a very small underestimation in the number of landslides can result in a significant decrease in the performance of a threshold measured by the skill scores. We show that the variations in the skill scores are different for different uncertainty of events above or below the threshold. This

Meson production near threshold: physics implications and new technical challenges

Energy Technology Data Exchange (ETDEWEB)

Meyer, H.O. [Indiana Univ., Bloomington, IN (United States). Dept. of Physics

1995-02-01

Recently, the study of pion production in few-nucleon systems has been advanced considerably, mainly due to experiments using internal targets in stored, cooled beams. Experimental progress has inspired theoretical insights: from measurements close to threshold we have learned that an enhancement of the axial charge caused by heavy-meson exchange significantly contributes to pion production. The study of the production of pions, as well as heavier mesons, with stored polarized beams and polarized internal targets is likely to heave important consequences for our understanding of the nuclear force. (author). 42 refs, 11 figs.

Precise atomic-scale investigations of material sputtering process by light gas ions in pre-threshold energy region

CERN Document Server

Suvorov, A L

2002-01-01

Foundation and prospects of the new original technique of the sputtering yield determination of electro-conducting materials and sub-atomic layers on their surface by light gas ions the pre-threshold energy region (from 10 to 500 eV) are considered. The technique allows to identify individual surface vacancies, i.e., to count individual sputtered atoms directly. A short review of the original results obtained by using the developed techniques is given. Data are presented and analyzed concerning energy thresholds of the sputtering onset and energy dependences of sputtering yield in the threshold energy region for beryllium, tungsten, tungsten oxide, alternating tungsten-carbon layers, three carbon materials as well as for sub-atomic carbon layers on surface of certain metals at their bombardment by hydrogen, deuterium and/or helium ions

Phenomenology of threshold corrections for inclusive jet production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Kumar, M.C. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik

2013-09-15

We study one-jet inclusive hadro-production and compute the QCD threshold corrections for large transverse momentum of the jet in the soft-gluon resummation formalism at next-to-leading logarithmic accuracy. We use the resummed result to generate approximate QCD corrections at next-to-next-to leading order, compare with results in the literature and present rapidity integrated distributions of the jet's transverse momentum for Tevatron and LHC. For the threshold approximation we investigate its kinematical range of validity as well as its dependence on the jet's cone size and kinematics.

Antiproton production in heavy-ion collisions at energies below the threshold

International Nuclear Information System (INIS)

Schroeter, A.

1993-08-01

In the framework of this thesis the antiproton production in heavy ion collisions at projectile energies far below the threshold for anti p production in nucleon-nucleon collisions (5.63 GeV/u) was studied. A suited detection apparature was developed and constructed at the fragment separator-magnet spectrometer at the Society for Heavy Ion Research (GSI). For the identification of the antiprotons the momentum of the particles emitted in beam direction was measured and their velocity multiple-redundantly determined by means of time-of-flight measurements and threshold Cherenkov detectors. By this way the antiprotons could be in spite of low anti p production cross sections and high production rates for lighter particles (R anti p: R K - -:R π - -∼1:5*10 3 :10 7 ) background-freely determined. By this experiment for Ne+NaF, Cu, Sn, and Bi as well ass Ni+Ni collisions at incident energies between 1.6 GeV/u and 2.0 GeV/u production cross sections for antiprotons in the momentum range between 1.0 GeV/c and 2.2 GeV/c and for kaons and pions between 0.5 GeV/c and 2.8 GeV/c were measured, in order to study the influence of collisional-system size, incident energy, and secondary-particle momentum on the production probabilities and to contribute in comparison with the prognoses of theoretical models to the explanation of the particle production mechanisms. (HSI)

Photoproduction of neutral kaons in the threshold region

International Nuclear Information System (INIS)

Takahashi, Toshiyuki

2004-01-01

It is expected that γ + n → K 0 + Λ reaction provides important information to the study of strangeness creation mechanism. Neutral Kaon Spectrometer (NKS) has been constructed at Laboratory of Nuclear Science, Tohoku University, which was designed to measure pions with magnetic spectrometer after the K s 0 → π + π - decay to identify K 0 by reconstructing the reaction. Principle of the design of the spectrometer and experimental set up are described. Up to the present quasi-free reaction from carbon target has been successfully observed in the threshold energy region. K s 0 was clearly separated in the preliminary data analysis indicating that performance of NKS is high enough to the objective. Information of γ + n → K 0 + Λ reaction is expected to be obtained by further analysis. (S. Funahashi)

Re-examination of the threshold energy surface in copper

International Nuclear Information System (INIS)

King, W.E.; Benedek, R.; Merkle, K.L.; Meshii, M.

1981-01-01

Radiation-induced defect production in copper has been studied using in-situ electrical resistivity damage-rate measurements in the HVEM and molecular dynamics simulations. Analysis of the results yields a threshold energy surface characterized by two isolated pockets of low threshold energy centered at and surrounded by regions of much higher threshold energy; the corresponding damage function exhibits a plateau at 0.65 Frenkel pairs. A Frenkel pair resistivity of (2.75/sub -0.2/ + 0 6 ) x 10 - 4 Ω-cm is proposed. A model damage function is constructed and compared to results from ion irradiation damage-rate measurements. 7 figures

FDI technology spillover and threshold effect of the technology gap: regional differences in the Chinese industrial sector.

Science.gov (United States)

Wang, Hui; Liu, Huifang; Cao, Zhiyong; Wang, Bowen

2016-01-01

This paper presents a new perspective that there is a double-threshold effect in terms of the technology gap existing in the foreign direct investment (FDI) technology spillover process in different regional Chinese industrial sectors. In this paper, a double-threshold regression model was established to examine the relation between the threshold effect of the technology gap and technology spillover. Based on the provincial panel data of Chinese industrial sectors from 2000 to 2011, the empirical results reveal that there are two threshold values, which are 1.254 and 2.163, in terms of the technology gap in the industrial sector in eastern China. There are also two threshold values in both the central and western industrial sector, which are 1.516, 2.694 and 1.635, 2.714, respectively. The technology spillover is a decreasing function of the technology gap in both the eastern and western industrial sectors, but a concave curve function of the technology gap is in the central industrial sectors. Furthermore, the FDI technology spillover has increased gradually in recent years. Based on the empirical results, suggestions were proposed to elucidate the introduction of the FDI and the improvement in the industrial added value in different regions of China.

The responsible region and the symptomatic threshold of cerebral blood flow and oxygen metabolism for Broca's aphasia using positron emission tomography

International Nuclear Information System (INIS)

Kato, Toshiaki; Ujike, Takashi; Kitamura, Shin; Soeda, Toshiyuki; Terashi, Akiro

1987-01-01

This study was designed to investigate the responsible region and the symptomatic flow and metabolism threshold for Broca's aphasia. Regional cerebral blood flow (CBF) and oxygen metabolism (CMRO 2 ) were measured by positron emission tomography (PET) using 15 O steady state method in eight patients with Broca's aphasia due to cerebral infarction and thirty patients without aphasia. During scanning, patients closed their eyes and were kept free from any stimuration. X-CT scan revealed abnormal low density in Broca's area which includes cortex and subcortex in the anterior region to Sylvian fissure in three patients with aphasia. In the other five patients with aphasia X-CT scan showed no abnormal low density in Broca's area, showed it in basal ganglionic region and subcortex. PET study revealed reduction of CBF and CMRO 2 in Broca's area in all cases with Broca's aphasia. CBF and CMRO 2 of Broca's area of aphasic patients were compared to those of non aphasic patients to obtain the symptomatic threshold in CBF and CMRO 2 . The values of symptomatic threshold were 20 - 27 ml/100 g/min in CBF and 2.0 ml/100 g/min in CMRO 2 . The symptomatic threshold differed from the threshold for development of abnormal low density on X-CT, therefore the measurement of CBF and CMRO 2 were useful in studying the responsible region for aphasia. (author)

Quantum threshold reflection is not a consequence of a region of the long-range attractive potential with rapidly varying de Broglie wavelength

Science.gov (United States)

Petersen, Jakob; Pollak, Eli; Miret-Artes, Salvador

2018-04-01

Quantum threshold reflection is a well-known quantum phenomenon which prescribes that at threshold, except for special circumstances, a quantum particle scattering from any potential, even if attractive at long range, will be reflected with unit probability. In the past, this property had been associated with the so-called badlands region of the potential, where the semiclassical description of the scattering fails due to a rapid spatial variation of the de Broglie wavelength. This badlands region occurs far from the strong interaction region of the potential and has therefore been used to "explain" the quantum reflection phenomenon. In this paper we show that the badlands region of the interaction potential is immaterial. The extremely long wavelength of the scattered particle at threshold is much longer than the spatial extension of the badlands region, which therefore does not affect the scattering. For this purpose, we review and generalize the proof for the existence of quantum threshold reflection to stress that it is only a consequence of continuity and boundary conditions. The nonlocal character of the scattering implies that the whole interaction potential is involved in the phenomenon. We then provide a detailed numerical study of the threshold scattering of a particle by a Morse potential and an Eckart potential, especially in the time domain. We compare exact quantum computations with incoherent results obtained from a classical Wigner approximation. This study shows that close to threshold the time-dependent amplitude of the scattered particle is negligible in the badlands region and is the same whether the potential has a reflecting wall as in the Morse potential or a steplike structure as in the Eckart smooth step potential. The mean flight time of the particle is not shortened due to a local reflection from the badlands region or due to the lower density of the wave function at short distances. This study should serve to definitely rule out the

Near-threshold photoproduction of {phi} mesons from deuterium

Energy Technology Data Exchange (ETDEWEB)

Qian, X., E-mail: xqian@caltech.ed [Duke University, Durham, NC 27708 (United States); Kellogg Radiation Laboratory, California Institute of Technology, CA 91125 (United States); Chen, W.; Gao, H. [Duke University, Durham, NC 27708 (United States); Hicks, K. [Ohio University, Athens, OH 45701 (United States); Kramer, K. [Duke University, Durham, NC 27708 (United States); Laget, J.M. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Mibe, T. [Ohio University, Athens, OH 45701 (United States); Qiang, Y. [Duke University, Durham, NC 27708 (United States); Stepanyan, S. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Tedeschi, D.J. [University of South Carolina, Columbia, SC 29208 (United States); Xu, W. [Massachusetts Institute of Technology, Cambridge, MA 02139-4307 (United States); Adhikari, K.P.; Amaryan, M. [Old Dominion University, Norfolk, VA 23529 (United States); Anghinolfi, M. [INFN, Sezione di Genova, 16146 Genova (Italy); Ball, J. [CEA, Centre de Saclay, Irfu/Service de Physique Nucleaire, 91191 Gif-sur-Yvette (France); Battaglieri, M. [INFN, Sezione di Genova, 16146 Genova (Italy); Batourine, V. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Bedlinskiy, I. [Institute of Theoretical and Experimental Physics, Moscow 117259 (Russian Federation); Bellis, M. [Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Biselli, A.S. [Fairfield University, Fairfield, CT 06824 (United States); Carnegie Mellon University, Pittsburgh, PA 15213 (United States)

2011-02-07

We report the first, kinematically-complete measurement of the differential cross section of {phi}-meson photoproduction from deuterium near the production threshold for a proton using the CLAS detector and a tagged-photon beam in Hall B at Jefferson Lab. The measurement was carried out by a triple coincidence detection of a proton, K{sup +} and K{sup -} near the theoretical production threshold of 1.57 GeV. The extracted differential cross sections (d{sigma})/(dt) for the initial photon energy range of 1.65-1.75 GeV are consistent with predictions based on a quasifree mechanism. Our finding is different from recent LEPS results on {phi}-meson photoproduction from deuterium in a similar incident photon energy range, but in a different momentum transfer region.

Multiple Colliding Electromagnetic Pulses: A Way to Lower the Threshold of e+e- Pair Production from Vacuum

International Nuclear Information System (INIS)

Bulanov, S. S.; Mur, V. D.; Narozhny, N. B.; Nees, J.; Popov, V. S.

2010-01-01

The scheme of a simultaneous multiple pulse focusing on one spot naturally arises from the structural features of projected new laser systems, such as the Extreme Light Infrastructure (ELI) and High Power laser Energy Research (HiPER). It is shown that the multiple pulse configuration is beneficial for observing e + e - pair production from a vacuum under the action of sufficiently strong electromagnetic fields. The field of focused pulses is described using a realistic three-dimensional model based on an exact solution of the Maxwell equations. The e + e - pair production threshold in terms of electromagnetic field energy can be substantially lowered if, instead of one or even two colliding pulses, multiple pulses are focused on one spot. The multiple pulse interaction geometry gives rise to subwavelength field features in the focal region. These features result in the production of extremely short e + e - bunches.

Particles near threshold

International Nuclear Information System (INIS)

Bhattacharya, T.; Willenbrock, S.

1993-01-01

We propose returning to the definition of the width of a particle in terms of the pole in the particle's propagator. Away from thresholds, this definition of width is equivalent to the standard perturbative definition, up to next-to-leading order; however, near a threshold, the two definitions differ significantly. The width as defined by the pole position provides more information in the threshold region than the standard perturbative definition and, in contrast with the perturbative definition, does not vanish when a two-particle s-wave threshold is approached from below

Segmentasi Pembuluh Darah Retina Pada Citra Fundus Menggunakan Gradient Based Adaptive Thresholding Dan Region Growing

Directory of Open Access Journals (Sweden)

Deni Sutaji

2016-07-01

Full Text Available AbstrakSegmentasi pembuluh darah pada citra fundus retina menjadi hal yang substansial dalam dunia kedokteran, karena dapat digunakan untuk mendeteksi penyakit, seperti: diabetic retinopathy, hypertension, dan cardiovascular. Dokter membutuhkan waktu sekitar dua jam untuk mendeteksi pembuluh darah retina, sehingga diperlukan metode yang dapat membantu screening agar lebih cepat.Penelitian sebelumnya mampu melakukan segmentasi pembuluh darah yang sensitif terhadap variasi ukuran lebar pembuluh darah namun masih terjadi over-segmentasi pada area patologi. Oleh karena itu, penelitian ini bertujuan untuk mengembangkan metode segmentasi pembuluh darah pada citra fundus retina yang dapat mengurangi over-segmentasi pada area patologi menggunakan Gradient Based Adaptive Thresholding dan Region Growing.Metode yang diusulkan terdiri dari 3 tahap, yaitu segmentasi pembuluh darah utama, deteksi area patologi dan segmentasi pembuluh darah tipis. Tahap segmentasi pembuluh darah utama menggunakan high-pass filtering dan tophat reconstruction pada kanal hijau citra yang sudah diperbaiki kontrasnya sehingga lebih jelas perbedaan antara pembuluh darah dan background. Tahap deteksi area patologi menggunakan metode Gradient Based Adaptive Thresholding. Tahap segmentasi pembuluh darah tipis menggunakan Region Growing berdasarkan informasi label pembuluh darah utama dan label area patologi. Hasil segmentasi pembuluh darah utama dan pembuluh darah tipis kemudian digabungkan sehingga menjadi keluaran sistem berupa citra biner pembuluh darah. Berdasarkan hasil uji coba, metode ini mampu melakukan segmentasi pembuluh darah retina dengan baik pada citra fundus DRIVE, yaitu dengan akurasi rata-rata 95.25% dan nilai Area Under Curve (AUC pada kurva Relative Operating Characteristic (ROC sebesar 74.28%.                           Kata Kunci: citra fundus retina, gradient based adaptive thresholding, patologi, pembuluh darah retina, region growing

Optimal replacement policy of products with repair-cost threshold after the extended warranty

Institute of Scientific and Technical Information of China (English)

Lijun Shang; Zhiqiang Cai

2017-01-01

The reliability of the product sold under a warranty is usually maintained by the manufacturer during the warranty period. After the expiry of the warranty, however, the consumer confronts a problem about how to maintain the reliability of the product. This paper proposes, from the consumer's perspective, a replace-ment policy after the extended warranty, under the assumption that the product is sold under the renewable free replacement warranty (RFRW) policy in which the replacement is dependent on the repair-cost threshold. The proposed replacement policy is the replacement after the extended warranty is performed by the consumer based on the repair-cost threshold or preventive replacement (PR) age, which are decision variables. The expected cost rate model is derived from the consumer's perspective. The existence and uniqueness of the optimal solution that minimizes the expected cost rate per unit time are offered. Finally, a numeri-cal example is presented to exemplify the proposed model.

Double Photoionization Near Threshold

Science.gov (United States)

Wehlitz, Ralf

2007-01-01

The threshold region of the double-photoionization cross section is of particular interest because both ejected electrons move slowly in the Coulomb field of the residual ion. Near threshold both electrons have time to interact with each other and with the residual ion. Also, different theoretical models compete to describe the double-photoionization cross section in the threshold region. We have investigated that cross section for lithium and beryllium and have analyzed our data with respect to the latest results in the Coulomb-dipole theory. We find that our data support the idea of a Coulomb-dipole interaction.

Non-abelian factorisation for next-to-leading-power threshold logarithms

International Nuclear Information System (INIS)

Bonocore, D.; Laenen, E.; Magnea, L.; Vernazza, L.; White, C.D.

2016-01-01

Soft and collinear radiation is responsible for large corrections to many hadronic cross sections, near thresholds for the production of heavy final states. There is much interest in extending our understanding of this radiation to next-to-leading power (NLP) in the threshold expansion. In this paper, we generalise a previously proposed all-order NLP factorisation formula to include non-abelian corrections. We define a non-abelian radiative jet function, organising collinear enhancements at NLP, and compute it for quark jets at one loop. We discuss in detail the issue of double counting between soft and collinear regions. Finally, we verify our prescription by reproducing all NLP logarithms in Drell-Yan production up to NNLO, including those associated with double real emission. Our results constitute an important step in the development of a fully general resummation formalism for NLP threshold effects.

Non-abelian factorisation for next-to-leading-power threshold logarithms

Energy Technology Data Exchange (ETDEWEB)

Bonocore, D. [Nikhef, Science Park 105, NL-1098 XG Amsterdam (Netherlands); Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, Sommerfeldstr. 16, 52074 Aachen (Germany); Laenen, E. [Nikhef, Science Park 105, NL-1098 XG Amsterdam (Netherlands); ITFA, University of Amsterdam, Science Park 904, Amsterdam (Netherlands); ITF, Utrecht University, Leuvenlaan 4, Utrecht (Netherlands); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106-4030 (United States); Magnea, L. [Dipartimento di Fisica, Università di Torino and INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Vernazza, L. [Higgs Centre for Theoretical Physics, School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom); White, C.D. [Centre for Research in String Theory, School of Physics and Astronomy, Queen Mary University of London, 327 Mile End Road, London E1 4NS (United Kingdom)

2016-12-22

Soft and collinear radiation is responsible for large corrections to many hadronic cross sections, near thresholds for the production of heavy final states. There is much interest in extending our understanding of this radiation to next-to-leading power (NLP) in the threshold expansion. In this paper, we generalise a previously proposed all-order NLP factorisation formula to include non-abelian corrections. We define a non-abelian radiative jet function, organising collinear enhancements at NLP, and compute it for quark jets at one loop. We discuss in detail the issue of double counting between soft and collinear regions. Finally, we verify our prescription by reproducing all NLP logarithms in Drell-Yan production up to NNLO, including those associated with double real emission. Our results constitute an important step in the development of a fully general resummation formalism for NLP threshold effects.

Subthreshold and near-threshold K+-meson photoproduction on nuclei

International Nuclear Information System (INIS)

Paryev, E.Ya.

2000-01-01

The inclusive K + -meson production in photon-induced reactions in the near-threshold and subthreshold energy regimes is analyzed for the one-step (γN → K + Y, Y = Λ, Σ) incoherent production processes on the basis of an appropriate new folding model that takes properly into account the struck-target nucleon-removal energy and the internal momentum distribution (nucleon spectral function), extracted from recent quasielastic-electron-scattering experiments and from many-body calculations based on realistic models of NN interaction. Simple parametrizations of the total and differential cross sections for K + production in photon-nucleon collisions are presented. A comparison of the model calculations of the K + differential cross sections for γ 12 C interactions in the threshold region with existing experimental data is given, which displays the contributions to K + production at considered incident energies from the use of the single-particle part, as well as high momentum and high removal energy part, of the nucleon spectral function. Detailed predictions for the K + total and differential cross sections for γ 2 H, γ 12 C, and γ 208 Pb interactions at subthreshold and near-threshold energies are provided. The effect of the uncertainties in the elementary K + -production cross sections on the K + yield is explored

W-pair production near threshold in unstable particle effective theory

Energy Technology Data Exchange (ETDEWEB)

Falgari, Pietro

2008-11-07

In this thesis we present a dedicated study of the four-fermion production process e{sup +}e{sup -}{yields}{mu}{sup -} anti {nu}{sub {mu}}u anti dX near the W-pair production threshold, in view of its importance for a precise determination of the W-boson mass at the ILC. The calculation is performed in the framework of unstable-particle effective theory, which allows for a gauge-invariant inclusion of instability effects, and for a systematic approximation of the full cross section with an expansion in the coupling constants, the ratio {gamma}{sub W}/M{sub W}, and the non-relativistic velocity v of the W boson. The effective-theory result, computed to next-to-leading order in the expansion parameters {gamma}{sub W}/M{sub W}{proportional_to}{alpha}{sub ew}{proportional_to}v{sup 2}, is compared to the full numerical next-to-leading order calculation of the four-fermion production cross section, and agreement to better than 0.5% is found in the region of validity of the effective theory. Furthermore, we estimate the contributions of missing higher-order corrections to the four-fermion process, and how they translate into an error on the W-boson mass determination. We find that the dominant theoretical uncertainty on MW is currently due to an incomplete treatment of initial-state radiation, while the remaining combined uncertainty of the two NLO calculations translates into {delta}M{sub W}{approx} 5 MeV. The latter error is removed by an explicit computation of the dominant missing terms, which originate from the expansion in v of next-to-next-to-leading order Standard Model diagrams. The effect of resummation of logarithmically-enhanced terms is also investigated, but found to be negligible. (orig.)

Technical Note: An operational landslide early warning system at regional scale based on space-time variable rainfall thresholds

Science.gov (United States)

Segoni, S.; Battistini, A.; Rossi, G.; Rosi, A.; Lagomarsino, D.; Catani, F.; Moretti, S.; Casagli, N.

2014-10-01

We set up an early warning system for rainfall-induced landslides in Tuscany (23 000 km2). The system is based on a set of state-of-the-art intensity-duration rainfall thresholds (Segoni et al., 2014b), makes use of LAMI rainfall forecasts and real-time rainfall data provided by an automated network of more than 300 rain-gauges. The system was implemented in a WebGIS to ease the operational use in civil protection procedures: it is simple and intuitive to consult and it provides different outputs. Switching among different views, the system is able to focus both on monitoring of real time data and on forecasting at different lead times up to 48 h. Moreover, the system can switch between a very straightforward view where a synoptic scenario of the hazard can be shown all over the region and a more in-depth view were the rainfall path of rain-gauges can be displayed and constantly compared with rainfall thresholds. To better account for the high spatial variability of the physical features, which affects the relationship between rainfall and landslides, the region is subdivided into 25 alert zones, each provided with a specific threshold. The warning system reflects this subdivision: using a network of 332 rain gauges, it allows monitoring each alert zone separately and warnings can be issued independently from an alert zone to another. An important feature of the warning system is the use of thresholds that may vary in time adapting at the conditions of the rainfall path recorded by the rain-gauges. Depending on when the starting time of the rainfall event is set, the comparison with the threshold may produce different outcomes. Therefore, a recursive algorithm was developed to check and compare with the thresholds all possible starting times, highlighting the worst scenario and showing in the WebGIS interface at what time and how much the rainfall path has exceeded or will exceed the most critical threshold. Besides forecasting and monitoring the hazard scenario

Photoionization cross section measurements of the excited states of cobalt in the near-threshold region

Directory of Open Access Journals (Sweden)

Xianfeng Zheng

2014-10-01

Full Text Available We present measurements of photoionization cross-sections of the excited states of cobalt using a two-color, two-step resonance ionization technique in conjunction with a molecular beam time of flight (TOF mass spectrometer. The atoms were produced by the laser vaporization of a cobalt rod, coupled with a supersonic gas jet. The absolute photoionization cross-sections at threshold and near-threshold regions (0-1.2 eV were measured, and the measured values ranged from 4.2±0.7 Mb to 10.5±1.8 Mb. The lifetimes of four odd parity energy levels are reported for the first time.

Climate change and critical thresholds in China's food security

International Nuclear Information System (INIS)

Xiong, Wei; Lin, Erda; Ju, Hui; Xu, Yinlong

2007-01-01

Identification of 'critical thresholds' of temperature increase is an essential task for inform policy decisions on establishing greenhouse gas (GHG) emission targets. We use the A2 (medium-high GHG emission pathway) and B2 (medium-low) climate change scenarios produced by the Regional Climate Model PRECIS, the crop model - CERES, and socio-economic scenarios described by IPCC SRES, to simulate the average yield changes per hectare of three main grain crops (rice, wheat, and maize) at 50 km x 50 km scale. The threshold of food production to temperature increases was analyzed based on the relationship between yield changes and temperature rise, and then food security was discussed corresponding to each IPCC SRES scenario. The results show that without the CO2 fertilization effect in the analysis, the yield per hectare for the three crops would fall consistently as temperature rises beyond 2.5C; when the CO2 fertilization effect was included in the simulation, there were no adverse impacts on China's food production under the projected range of temperature rise (0.9-3.9C). A critical threshold of temperature increase was not found for food production. When the socio-economic scenarios, agricultural technology development and international trade were incorporated in the analysis, China's internal food production would meet a critical threshold of basic demand (300 kg/capita) while it would not under A2 (no CO2 fertilization); whereas basic food demand would be satisfied under both A2 and B2, and would even meet a higher food demand threshold required to sustain economic growth (400 kg/capita) under B2, when CO2 fertilization was considered

Threshold resummation for the LHC: all order colour structure and application to squark production

International Nuclear Information System (INIS)

Schwinn, Ch.; Falgari, P.; Benke, M.

2009-01-01

We present a factorization formula for the production of pairs of heavy coloured particles in hadronic collision at the production threshold. We construct a basis in colour space that diagonalized the soft function appearing in the factorization formula to all orders in perturbation theory. We perform a resummation of soft gluon effects in momentum space and present results for the example of squark-antisquark production at the LHC. (author)

QCD NLO with POWHEG matching and top threshold matching in WHIZARD

Energy Technology Data Exchange (ETDEWEB)

Reuter, Juergen; Nejad, Bijan Chokoufe [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Bach, Fabian [European Commission, Luxembourg (Luxembourg); Kilian, Wolfgang [Siegen Univ. (Germany); Stahlhofen, Maximilian [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Mainz Univ. (Germany). PRISMA Cluster of Excellence; Weiss, Christian [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Siegen Univ. (Germany)

2016-01-15

We present the status of the automation of NLO processes within the event generator WHIZARD. The program provides an automated FKS subtraction and phase space integration over the FKS regions, while the (QCD) NLO matrix element is accessed via the Binoth Les Houches Interface from an externally linked one-loop program. Massless and massive test cases and validation are shown for several e{sup +}e{sup -} processes. Furthermore, we discuss work in progress and future plans. The second part covers the matching of the NRQCD prediction with NLL threshold resummation to the NLO continuum top pair production at lepton colliders. Both the S-wave and P-wave production of the top pair are taken into account in the resummation. The inclusion in WHIZARD allows to study more exclusive observables than just the total cross section and automatically accounts for important electroweak and relativistic corrections in the threshold region.

QCD NLO with POWHEG matching and top threshold matching in WHIZARD

International Nuclear Information System (INIS)

Reuter, Juergen; Nejad, Bijan Chokoufe; Kilian, Wolfgang; Stahlhofen, Maximilian

2016-01-01

We present the status of the automation of NLO processes within the event generator WHIZARD. The program provides an automated FKS subtraction and phase space integration over the FKS regions, while the (QCD) NLO matrix element is accessed via the Binoth Les Houches Interface from an externally linked one-loop program. Massless and massive test cases and validation are shown for several e + e - processes. Furthermore, we discuss work in progress and future plans. The second part covers the matching of the NRQCD prediction with NLL threshold resummation to the NLO continuum top pair production at lepton colliders. Both the S-wave and P-wave production of the top pair are taken into account in the resummation. The inclusion in WHIZARD allows to study more exclusive observables than just the total cross section and automatically accounts for important electroweak and relativistic corrections in the threshold region.

QCD threshold corrections for gluino pair production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Langenfeld, Ulrich [Wuerzburg Univ. (Germany); Moch, Sven-Olaf; Pfoh, Torsten [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2012-11-15

We present the complete threshold enhanced predictions in QCD for the total cross section of gluino pair production at hadron colliders at next-to-next-to-leading order. Thanks to the computation of the required one-loop hard matching coefficients our results are accurate to the next-to-next-to-leading logarithm. In a brief phenomenological study we provide predictions for the total hadronic cross sections at the LHC and we discuss the uncertainties arising from scale variations and the parton distribution functions.

Threshold region for Higgs boson production in gluon fusion.

Science.gov (United States)

Bonvini, Marco; Forte, Stefano; Ridolfi, Giovanni

2012-09-07

We provide a quantitative determination of the effective partonic kinematics for Higgs boson production in gluon fusion in terms of the collider energy at the LHC. We use the result to assess, as a function of the Higgs boson mass, whether the large m(t) approximation is adequate and Sudakov resummation advantageous. We argue that our results hold to all perturbative orders. Based on our results, we conclude that the full inclusion of finite top mass corrections is likely to be important for accurate phenomenology for a light Higgs boson with m(H)~125 GeV at the LHC with √s=14 TeV.

Productive Regions: Criteria and Classification

Directory of Open Access Journals (Sweden)

Vlasyuk L. I.

2012-03-01

Full Text Available An official statistical dataset for 80 territorial subjects of the Russian Federation for 2000, 2007 and 2009 has proved the hypothesis that, under the neoclassical concept, the resources move to regions with the highest marginal productivity of the factors of production, which leads to the accumulation of investment resources, while providing financial and social efficiency. Based on cluster analysis by three performance criteria, productive regions are identified, which are dominated by regions productive in the extraction of minerals. It is shown that the stability of the factors’ distribution in space determines the current and future specialization of regional economies

Photoproduction of {omega} mesons on nuclei near the production threshold

Energy Technology Data Exchange (ETDEWEB)

Nanova, M.; Friedrich, S.; Metag, V.; Thiel, M.; Gregor, R.; Kotulla, M.; Lugert, S.; Novotny, R.; Pant, L.M.; Pfeiffer, M.; Roy, A.; Schadmand, S.; Trnka, D.; Varma, R. [Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Weil, J.; Mosel, U. [Universitaet Giessen, Institut fuer Theoretische Physik I, Giessen (Germany); Anton, G.; Bogendoerfer, R.; Hoessl, J.; Suft, G. [Universitaet Erlangen, Physikalisches Institut, Erlangen (Germany); Bacelar, J.C.S.; Castelijns, R.; Loehner, H.; Messchendorp, J.G.; Shende, S. [Kernfysisch Versneller Institut, Groningen (Netherlands); Bartholomy, O.; Crede, V.; Ehmanns, A.; Essig, K.; Fabry, I.; Fuchs, M.; Funke, C.; Gutz, E.; Hoeffgen, S.; Hoffmeister, P.; Horn, I.; Junkersfeld, J.; Kalinowsky, H.; Klempt, E.; Lotz, J.; Pee, H. van; Schmidt, C.; Szczepanek, T.; Thoma, U.; Walther, D.; Weinheimer, C.; Wendel, C. [Helmholtz-Institut fuer Strahlen- und Kernphysik Universitaet Bonn, Bonn (Germany); Bayadilov, D. [Helmholtz-Institut fuer Strahlen- und Kernphysik Universitaet Bonn, Bonn (Germany); Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Beloglazov, Y.A.; Gridnev, A.B.; Lopatin, I.V.; Radkov, A.; Sumachev, V.V. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Dutz, H.; Elsner, D.; Ewald, R.; Gothe, R.; Klein, Frank; Klein, Friedrich; Konrad, M.; Menze, D.; Morales, C.; Ostrick, M.; Schmieden, H.; Schoch, B.; Suele, A. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Jaegle, I.; Krusche, B.; Mertens, T. [Universitaet Basel, Physikalisches Institut, Basel (Switzerland); Kopf, B. [Institut fuer Kern- und Teilchenphysik, TU Dresden, Dresden (Germany); Universitaet Bochum, Physikalisches Institut, Bochum (Germany); Langheinrich, J. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Universitaet Bochum, Physikalisches Institut, Bochum (Germany)

2011-02-15

The photoproduction of {omega} mesons on LH{sub 2}, C and Nb has been measured for incident photon energies from 900 to 1300MeV using the CB/TAPS detector at ELSA. The {omega} lineshape does not show any significant difference between the LH{sub 2} and the Nb targets. The experiment was motivated by transport calculations that predicted a sensitivity of the {omega} lineshape to in-medium modifications near the production threshold on a free nucleon of E{sub {gamma}}{sup lab}=1109 MeV. A comparison with recent calculations is given. (orig.)

Threshold Level and Traceability of Roundup Ready® Soybeans in Tofu Production

Directory of Open Access Journals (Sweden)

Zorica Nikolić

2017-01-01

Full Text Available The aim of this study is to assess DNA degradation, DNA amplification, and GMO quantity during tofu production. Soybean seeds were spiked with Roundup Ready® soybeans (RRS at 0.9, 2, 3 and 5 % (by mass, to assess the level of RSS that would be of practical interest for threshold labelling. Real-time polymerase chain reaction (PCR was more effective than conventional PCR in the analysis of raw soymilk, okara, boiled soymilk and tofu. The negative effect of grinding and mechanical manipulation was obvious in the okara sample prepared with 3 and 5 % RRS, where GMO content was reduced to (2.28±0.23 and (2.74±0.26 %, respectively. However, heating at 100 °C for 10 min did not cause significant degradation of DNA in all samples. The content of RRS in the final product, tofu, was reduced tenfold during processing, ranging from 0.07 to 0.46 %, which was below the labelling threshold level. The results are discussed in terms of global harmonization of GMO standards, which could have the positive effect on the trade of lightly processed foodstuffs such as tofu, especially regarding the labelling policies.

Threshold Level and Traceability of Roundup Ready® Soybeans in Tofu Production.

Science.gov (United States)

Nikolić, Zorica; Petrović, Gordana; Panković, Dejana; Ignjatov, Maja; Marinković, Dragana; Stojanović, Milan; Đorđević, Vuk

2017-12-01

The aim of this study is to assess DNA degradation, DNA amplification, and GMO quantity during tofu production. Soybean seeds were spiked with Roundup Ready ® soybeans (RRS) at 0.9, 2, 3 and 5% (by mass), to assess the level of RSS that would be of practical interest for threshold labelling. Real-time polymerase chain reaction (PCR) was more effective than conventional PCR in the analysis of raw soymilk, okara, boiled soymilk and tofu. The negative effect of grinding and mechanical manipulation was obvious in the okara sample prepared with 3 and 5% RRS, where GMO content was reduced to (2.28±0.23) and (2.74±0.26) %, respectively. However, heating at 100 °C for 10 min did not cause significant degradation of DNA in all samples. The content of RRS in the final product, tofu, was reduced tenfold during processing, ranging from 0.07 to 0.46%, which was below the labelling threshold level. The results are discussed in terms of global harmonization of GMO standards, which could have the positive effect on the trade of lightly processed foodstuffs such as tofu, especially regarding the labelling policies.

Physics near the strange and charm production thresholds

International Nuclear Information System (INIS)

Nagamiya, S.; Bland, L.C.

1995-01-01

LISS is a Light-Ion Spin Synchrotron and storage ring that is being considered as an upgrade of the Indiana University Cyclotron Facility. Current plans call for a racetrack design for the ring that will provide variable energy polarized proton and deuteron beams up to a momentum of 16 GeV/c and unpolarized light ions with 3 ≤A ≤ 40 accelerated to comparable rigidities. Experiments would be conducted using both polarized and unpolarized internal targets. The racetrack design for the ring will provide for two ∼100-m long, zero-dispersion straight sections that allow for the installation of sophisticated experimental equipment. The ring design will incorporate the recently developed technologies of Siberian snakes allowing for relatively straightforward acceleration and use of polarized beams for high-precision experiments, electron cooling for shrinking the emittance of the stored beams, and carrier-free polarized internal targets. This talk will focus on that part of the physics Program of the LISS facility associated with the production of strange and charmed quarks. Examples will include the study of the spin-dependence of the A-nucleon scattering length; second-generation associated hyperon production experiments emphasizing polarization transfer and exclusive identification of the produced hyperons (ΛΣ, etc.) with the goal of understanding the dynamical origin of hyperon polarization; and studies of the total charm production cross section in p-p collisions near threshold

Diagrammatic Approach to Meson Production in Proton-Proton Collisions near Threshold

International Nuclear Information System (INIS)

Kaiser, Norbert

2000-01-01

We evaluate the threshold T-matrices for the reactions pp → ppπ 0 , pnπ + , ppη, ppω,pΛK + , and pn → pnη in a relativistic Feynman diagram approach. We employ an effective range approximation to take care of the strong S-wave pN and pΛ final-state interaction. We stress that the heavy baryon formalism is not applicable in the NN-system above π-production threshold due to the large external momentum, vertical-bar rvec p vertical-bar ≅ √(Mm π ). The magnitudes of the experimental threshold amplitudes extracted from total cross section data, script-A = (2.7 - 0.3i)fm 4 , script-B = (2.8 - 1.5i)fm 4 , vertical-bar script-C vertical-bar = 1.32 fm 4 , vertical-bar Omega vertical-bar = 0.53 fm 4 , script-K = √(2(vertical-bar)K s (vertical-bar) 2 + (vertical-bar)K t (vertical-bar) 2 ) = 0.38 fm 4 and (vertical-bar)script-D(vertical-bar) = 2.3 fm 4 can be reproduced by (long-range) o ne-pion exchange and short-range vector meson exchanges, with the latter giving the largest contributions. Pion loop effects in pp → ppπ 0 appear to be small. The presented diagrammatic approach requires further tests via studies of angular distributions and polarization observables

Near threshold two meson production in hardonic fusion reactions

International Nuclear Information System (INIS)

Jahn, R.

1991-01-01

An approved and funded exclusive COSY experiment is presented, which focuses on near threshold two meson production via the reactions p+d→ 3 He + π + π - and p+d→ 3 He+K + K-. It takes advantage of the high quality of the cooled external COSY beam and the existing spectrometer BIG KARL. The setup consists of a vertex wall and a scintillator cylinder and endcap covering a 4π solid angle. The large efficiency and high resolution of this detection method will yield precision data on the low energy (T 0 (975). Existing inclusive data as well as first results of a very recent 'semi-exclusive' experiment performed at SATURNE will be also be presented

2 pi production in pp collisions close to threshold

CERN Document Server

Bilger, R; Calén, H; Clement, H; Dyring, J; Ekström, C; Fransson, K; Gustafsson, L; Häggström, S; Hoeistad, B; Johanson, J; Johansson, A; Johansson, T; Khoukaz, A; Kilian, K; Kullander, K; Kupsc, A; Marciniewski, P; Morosov, B; Moertsell, A; Oelert, W; Paetzold, J; Ruber, Roger J M Y; Schepkin, M G; Stepaniak, J; Sukhanov, A; Sundberg, P; Turowiecki, A; Wagner, G J; Wilhelmi, Z; Zabierowski, J; Zernov, A; Zlomanczuk, Yu

2000-01-01

The reaction pp -> NN pi pi has been measured close to threshold in the energy range from 650 to 775 MeV using the PROMICE/WASA setup at CELSIUS. These data constitute the first exclusive high-statistics measurements of this reaction on a pure hydrogen target, supplying both differential and integral cross sections. The obtained total cross sections are an order of magnitude below previously published bubble-chamber results. Differential spectra for pp -> pp pi sup -pi sup + are close to phase space predictions identifying the production via N*(1440) -> N(pi pi) sub I sub = sub L sub = sub 0 as the dominant process. Possible contributions from dibaryon resonances are discussed.

Climate change and critical thresholds in China's food security

Energy Technology Data Exchange (ETDEWEB)

Xiong, Wei; Lin, Erda; Ju, Hui; Xu, Yinlong [Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing (China)

2007-03-15

Identification of 'critical thresholds' of temperature increase is an essential task for inform policy decisions on establishing greenhouse gas (GHG) emission targets. We use the A2 (medium-high GHG emission pathway) and B2 (medium-low) climate change scenarios produced by the Regional Climate Model PRECIS, the crop model - CERES, and socio-economic scenarios described by IPCC SRES, to simulate the average yield changes per hectare of three main grain crops (rice, wheat, and maize) at 50 km x 50 km scale. The threshold of food production to temperature increases was analyzed based on the relationship between yield changes and temperature rise, and then food security was discussed corresponding to each IPCC SRES scenario. The results show that without the CO2 fertilization effect in the analysis, the yield per hectare for the three crops would fall consistently as temperature rises beyond 2.5C; when the CO2 fertilization effect was included in the simulation, there were no adverse impacts on China's food production under the projected range of temperature rise (0.9-3.9C). A critical threshold of temperature increase was not found for food production. When the socio-economic scenarios, agricultural technology development and international trade were incorporated in the analysis, China's internal food production would meet a critical threshold of basic demand (300 kg/capita) while it would not under A2 (no CO2 fertilization); whereas basic food demand would be satisfied under both A2 and B2, and would even meet a higher food demand threshold required to sustain economic growth (400 kg/capita) under B2, when CO2 fertilization was considered.

Threshold Learning Dynamics in Social Networks

Science.gov (United States)

González-Avella, Juan Carlos; Eguíluz, Victor M.; Marsili, Matteo; Vega-Redondo, Fernado; San Miguel, Maxi

2011-01-01

Social learning is defined as the ability of a population to aggregate information, a process which must crucially depend on the mechanisms of social interaction. Consumers choosing which product to buy, or voters deciding which option to take with respect to an important issue, typically confront external signals to the information gathered from their contacts. Economic models typically predict that correct social learning occurs in large populations unless some individuals display unbounded influence. We challenge this conclusion by showing that an intuitive threshold process of individual adjustment does not always lead to such social learning. We find, specifically, that three generic regimes exist separated by sharp discontinuous transitions. And only in one of them, where the threshold is within a suitable intermediate range, the population learns the correct information. In the other two, where the threshold is either too high or too low, the system either freezes or enters into persistent flux, respectively. These regimes are generally observed in different social networks (both complex or regular), but limited interaction is found to promote correct learning by enlarging the parameter region where it occurs. PMID:21637714

Accelerator based production of fissile nuclides, threshold uranium price and perspectives

International Nuclear Information System (INIS)

Djordjevic, D.; Knapp, V.

1988-01-01

Accelerator breeder system characteristics are considered in this work. One such system which produces fissile nuclides can supply several thermal reactors with fissile fuel, so this system becomes analogous to an uranium enrichment facility with difference that fissile nuclides are produced by conversion of U-238 rather than by separation from natural uranium. This concept, with other long-term perspective for fission technology on the basis of development only one simpler technology. The influence of basic system characteristics on threshold uranium price is examined. Conditions for economically acceptable production are established. (author)

A new iterative triclass thresholding technique in image segmentation.

Science.gov (United States)

Cai, Hongmin; Yang, Zhong; Cao, Xinhua; Xia, Weiming; Xu, Xiaoyin

2014-03-01

We present a new method in image segmentation that is based on Otsu's method but iteratively searches for subregions of the image for segmentation, instead of treating the full image as a whole region for processing. The iterative method starts with Otsu's threshold and computes the mean values of the two classes as separated by the threshold. Based on the Otsu's threshold and the two mean values, the method separates the image into three classes instead of two as the standard Otsu's method does. The first two classes are determined as the foreground and background and they will not be processed further. The third class is denoted as a to-be-determined (TBD) region that is processed at next iteration. At the succeeding iteration, Otsu's method is applied on the TBD region to calculate a new threshold and two class means and the TBD region is again separated into three classes, namely, foreground, background, and a new TBD region, which by definition is smaller than the previous TBD regions. Then, the new TBD region is processed in the similar manner. The process stops when the Otsu's thresholds calculated between two iterations is less than a preset threshold. Then, all the intermediate foreground and background regions are, respectively, combined to create the final segmentation result. Tests on synthetic and real images showed that the new iterative method can achieve better performance than the standard Otsu's method in many challenging cases, such as identifying weak objects and revealing fine structures of complex objects while the added computational cost is minimal.

Third-order QCD corrections to heavy quark pair production near threshold

Energy Technology Data Exchange (ETDEWEB)

Schuller, Kurt

2008-11-07

The measurement of the top quark mass is an important task at the future International Linear Collider. The most promising process is the top quark pair production in the threshold region. In this region the top quarks behave non-relativistically and a perturbative treatment using effective field theories is possible. Current second order theoretical predictions in a fixed order approach show an uncertainty which is bigger than the expected experimental errors. Therefore, an improvement of the cross section calculation is desirable. There are two ways to incorporate higher order effects, one is to calculate the full next order in the fixed order approach, another possibility is to resum large logarithms. In this work, the fixed order calculation has been extended to the third order in perturbation theory for the QCD corrections. The result is a strongly improved scale behavior and a better understanding of heavy quarkonium systems. The Green function result is given in a semi-analytic form. The energy levels and wave functions for heavy quarkonium states have been calculated from the poles of the Green function and are presented for arbitrary quantum number n. The results have been implemented in a Mathematica program which makes the data easily accessible. Once some missing matching coefficients are calculated, and a complete electroweak calculation is available, the results of this work can be used to improve the precision of the top quark mass measurement to an uncertainty of less than 50 MeV. An inclusion of initial state radiation and beam effects are essential for a realistic observable. In the future, the results obtained could be used for a third order resummation of large logarithms. Further applications are also the extraction of the bottom quark mass with sum rules. (orig.)

Weak production of strangeness at threshold with polarization observables

International Nuclear Information System (INIS)

Baker, O.K.

2002-01-01

The differential cross section for the charged current electroweak reaction e → +p → ν → e +Λ → at threshold with polarization observables is presented. The form of the cross section at threshold for the reaction is simplified compared to higher energy. An expression is given for the invariant matrix element appropriate for the reaction when the incident electron is polarized, and the final state hyperon polarization is determined. The energy dependence of the resulting cross section is shown near threshold. Under the right kinematic conditions, there can be a sizeable enhancement in the cross section, making an experimental measurement of the weak axial-vector form factor feasible

Technical Note: An operational landslide early warning system at regional scale based on space-time-variable rainfall thresholds

Science.gov (United States)

Segoni, S.; Battistini, A.; Rossi, G.; Rosi, A.; Lagomarsino, D.; Catani, F.; Moretti, S.; Casagli, N.

2015-04-01

We set up an early warning system for rainfall-induced landslides in Tuscany (23 000 km2). The system is based on a set of state-of-the-art intensity-duration rainfall thresholds (Segoni et al., 2014b) and makes use of LAMI (Limited Area Model Italy) rainfall forecasts and real-time rainfall data provided by an automated network of more than 300 rain gauges. The system was implemented in a WebGIS to ease the operational use in civil protection procedures: it is simple and intuitive to consult, and it provides different outputs. When switching among different views, the system is able to focus both on monitoring of real-time data and on forecasting at different lead times up to 48 h. Moreover, the system can switch between a basic data view where a synoptic scenario of the hazard can be shown all over the region and a more in-depth view were the rainfall path of rain gauges can be displayed and constantly compared with rainfall thresholds. To better account for the variability of the geomorphological and meteorological settings encountered in Tuscany, the region is subdivided into 25 alert zones, each provided with a specific threshold. The warning system reflects this subdivision: using a network of more than 300 rain gauges, it allows for the monitoring of each alert zone separately so that warnings can be issued independently. An important feature of the warning system is that the visualization of the thresholds in the WebGIS interface may vary in time depending on when the starting time of the rainfall event is set. The starting time of the rainfall event is considered as a variable by the early warning system: whenever new rainfall data are available, a recursive algorithm identifies the starting time for which the rainfall path is closest to or overcomes the threshold. This is considered the most hazardous condition, and it is displayed by the WebGIS interface. The early warning system is used to forecast and monitor the landslide hazard in the whole region

Rainfall thresholds for the possible occurrence of landslides in Italy

Directory of Open Access Journals (Sweden)

M. T. Brunetti

2010-03-01

Full Text Available In Italy, rainfall is the primary trigger of landslides that frequently cause fatalities and large economic damage. Using a variety of information sources, we have compiled a catalogue listing 753 rainfall events that have resulted in landslides in Italy. For each event in the catalogue, the exact or approximate location of the landslide and the time or period of initiation of the slope failure is known, together with information on the rainfall duration D, and the rainfall mean intensity I, that have resulted in the slope failure. The catalogue represents the single largest collection of information on rainfall-induced landslides in Italy, and was exploited to determine the minimum rainfall conditions necessary for landslide occurrence in Italy, and in the Abruzzo Region, central Italy. For the purpose, new national rainfall thresholds for Italy and new regional rainfall thresholds for the Abruzzo Region were established, using two independent statistical methods, including a Bayesian inference method and a new Frequentist approach. The two methods proved complementary, with the Bayesian method more suited to analyze small data sets, and the Frequentist method performing better when applied to large data sets. The new regional thresholds for the Abruzzo Region are lower than the new national thresholds for Italy, and lower than the regional thresholds proposed in the literature for the Piedmont and Lombardy Regions in northern Italy, and for the Campania Region in southern Italy. This is important, because it shows that landslides in Italy can be triggered by less severe rainfall conditions than previously recognized. The Frequentist method experimented in this work allows for the definition of multiple minimum rainfall thresholds, each based on a different exceedance probability level. This makes the thresholds suited for the design of probabilistic schemes for the prediction of rainfall-induced landslides. A scheme based on four

Towards the high-accuracy determination of the 238U fission cross section at the threshold region at CERN – n_TOF

Directory of Open Access Journals (Sweden)

Diakaki M.

2016-01-01

Full Text Available The 238U fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The 238U fission cross section has been measured relative to the 235U fission cross section at CERN – n_TOF with different detection systems. These datasets have been collected and suitably combined to increase the counting statistics in the threshold region from about 300 keV up to 3 MeV. The results are compared with other experimental data, evaluated libraries, and the IAEA standards.

Regional differences of consumer preferences when shopping for regional products

Directory of Open Access Journals (Sweden)

Jitka Kalábová

2013-01-01

Full Text Available This paper presents partial results of a research on consumer preferences when shopping for groceries. It is focused on regional products and consumer preferences in relation to the country of origin of food products. The main objective of this paper is to find the existence of spatial relationships between spatial deployment of regional products and consumer preferences for regional products. It will be necessary to create a data model for monitoring the deployment of regional products and also a data model for tracking important indicators of consumer behavior in all regions of the Czech Republic. The results are based on questionnaire survey that was conducted within the period from October 2010 to January 2011 on a sample of 3767 respondents from the Czech Republic, via both online questionnaires and their printed version. For the data collection the questionnaire system ReLa, developed by the Department of Marketing and Trade at Faculty of Business and Economics at Mendel University in Brno, was used. Data was processed with statistical software STATISTICA (ver. 10. Spatial visualisation was processed with GIS software ArcGIS (ver. 10.1. Preferences for food of Czech origin were analysed in relation to identification criteria. The research results show that the origin of food has an important role in consumer purchase decision-making. There is no significant difference in importance of this factor based on gender of consumers, however, we could prove moderate dependence on respondent’s occupation, education and age. We could also experience regional differences in levels of preferences of local products or products of Czech origin in regard of 14 regions of the Czech Republic. χ2 (N = 3767 = 245.25; p < 0.001. Value of Pearson’s coefficient of contingency is 0.334.

Compositional threshold for Nuclear Waste Glass Durability

International Nuclear Information System (INIS)

Kruger, Albert A.; Farooqi, Rahmatullah; Hrma, Pavel R.

2013-01-01

Within the composition space of glasses, a distinct threshold appears to exist that separates 'good' glasses, i.e., those which are sufficiently durable, from 'bad' glasses of a low durability. The objective of our research is to clarify the origin of this threshold by exploring the relationship between glass composition, glass structure and chemical durability around the threshold region

Threshold and jet radius joint resummation for single-inclusive jet production

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiaohui [Beijing Normal Univ. (China). Center of Advanced Quantum Studies; Moch, Sven-Olaf [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Ringer, Felix [Lawrence Berkeley National Laboratory, Berkeley, CA (United States). Nuclear Science Division

2017-08-15

We present the first threshold and jet radius jointly resummed cross section for single-inclusive hadronic jet production. We work at next-to-leading logarithmic accuracy and our framework allows for a systematic extension beyond the currently achieved precision. Longstanding numerical issues are overcome by performing the resummation directly in momentum space within Soft Collinear Effective Theory. We present the first numerical results for the LHC and observe an improved description of the available data. Our results are of immediate relevance for LHC precision phenomenology including the extraction of parton distribution functions and the QCD strong coupling constant.

Phenomenology of QCD threshold resummation for gluino pair production at NNLL

Energy Technology Data Exchange (ETDEWEB)

Pfoh, Torsten

2013-02-15

We examine the impact of threshold resummation for the inclusive hadronic production cross section of gluino pairs at next-to-next-to-leading-logarithmic accuracy, compared to the exact next-to-leading- order cross section and the next-to-next-to-leading-order approximation. Here, we apply formulas derived recently in the classical Mellin-space formalism. Moreover, we give the analytic input for the alternative momentum-space formalism and discuss the crucial points of the numeric implementation. We find that soft resummation keeps the hadronic cross section close to the fixed next-to-leading-order result.

Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO2 tolerance in phytoplankton productivity

Science.gov (United States)

Deppeler, Stacy; Petrou, Katherina; Schulz, Kai G.; Westwood, Karen; Pearce, Imojen; McKinlay, John; Davidson, Andrew

2018-01-01

High-latitude oceans are anticipated to be some of the first regions affected by ocean acidification. Despite this, the effect of ocean acidification on natural communities of Antarctic marine microbes is still not well understood. In this study we exposed an early spring, coastal marine microbial community in Prydz Bay to CO2 levels ranging from ambient (343 µatm) to 1641 µatm in six 650 L minicosms. Productivity assays were performed to identify whether a CO2 threshold existed that led to a change in primary productivity, bacterial productivity, and the accumulation of chlorophyll a (Chl a) and particulate organic matter (POM) in the minicosms. In addition, photophysiological measurements were performed to identify possible mechanisms driving changes in the phytoplankton community. A critical threshold for tolerance to ocean acidification was identified in the phytoplankton community between 953 and 1140 µatm. CO2 levels ≥ 1140 µatm negatively affected photosynthetic performance and Chl a-normalised primary productivity (csGPP14C), causing significant reductions in gross primary production (GPP14C), Chl a accumulation, nutrient uptake, and POM production. However, there was no effect of CO2 on C : N ratios. Over time, the phytoplankton community acclimated to high CO2 conditions, showing a down-regulation of carbon concentrating mechanisms (CCMs) and likely adjusting other intracellular processes. Bacterial abundance initially increased in CO2 treatments ≥ 953 µatm (days 3-5), yet gross bacterial production (GBP14C) remained unchanged and cell-specific bacterial productivity (csBP14C) was reduced. Towards the end of the experiment, GBP14C and csBP14C markedly increased across all treatments regardless of CO2 availability. This coincided with increased organic matter availability (POC and PON) combined with improved efficiency of carbon uptake. Changes in phytoplankton community production could have negative effects on the Antarctic food web and the

Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO2 tolerance in phytoplankton productivity

Directory of Open Access Journals (Sweden)

S. Deppeler

2018-01-01

Full Text Available High-latitude oceans are anticipated to be some of the first regions affected by ocean acidification. Despite this, the effect of ocean acidification on natural communities of Antarctic marine microbes is still not well understood. In this study we exposed an early spring, coastal marine microbial community in Prydz Bay to CO2 levels ranging from ambient (343 µatm to 1641 µatm in six 650 L minicosms. Productivity assays were performed to identify whether a CO2 threshold existed that led to a change in primary productivity, bacterial productivity, and the accumulation of chlorophyll a (Chl a and particulate organic matter (POM in the minicosms. In addition, photophysiological measurements were performed to identify possible mechanisms driving changes in the phytoplankton community. A critical threshold for tolerance to ocean acidification was identified in the phytoplankton community between 953 and 1140 µatm. CO2 levels  ≥ 1140 µatm negatively affected photosynthetic performance and Chl a-normalised primary productivity (csGPP14C, causing significant reductions in gross primary production (GPP14C, Chl a accumulation, nutrient uptake, and POM production. However, there was no effect of CO2 on C : N ratios. Over time, the phytoplankton community acclimated to high CO2 conditions, showing a down-regulation of carbon concentrating mechanisms (CCMs and likely adjusting other intracellular processes. Bacterial abundance initially increased in CO2 treatments  ≥ 953 µatm (days 3–5, yet gross bacterial production (GBP14C remained unchanged and cell-specific bacterial productivity (csBP14C was reduced. Towards the end of the experiment, GBP14C and csBP14C markedly increased across all treatments regardless of CO2 availability. This coincided with increased organic matter availability (POC and PON combined with improved efficiency of carbon uptake. Changes in phytoplankton community production could have negative

Photoproduction of the vector mesons ω(782) and φ(1020) on the proton from the production threshold up to a photon energy of 2. 6 GeV

International Nuclear Information System (INIS)

Barth, J.

2002-05-01

This paper reports on a measurement of the photoproduction of ω(782) and Φ(1020) vector mesons with the SAPHIR detector at the electron accelerator facility ELSA. The incident photons were tagged in an energy range from reaction threshold up to 2.6 GeV. ω and Φ events were selected by separating their signal in the invariant mass spectrum of their decay products, i.e. in the π + π - π 0 and the K + K - system, respectively. As a cross check for normalization the inclusive two and three pion production was evaluated. The results agree with earlier experiments. From the experimental data total cross sections σ tot , differential cross sections dσ/dt as well as decay angular distributions in both, Gottfried Jackson and helicity frames, were extracted. For the ω production they show that diffractive processes play an important role as expected from higher energy data. However, at threshold s-channel resonances significantly contribute. In the region of large four-momentum transfers (vertical stroke t vertical stroke > 1 GeV 2 ) significant deviations from t-channel exchange mechanisms are observed. The Φ production can be described mainly by diffraction, but also other t-channel exchange processes seem to contribute. (orig.)

A Morphological Hessian Based Approach for Retinal Blood Vessels Segmentation and Denoising Using Region Based Otsu Thresholding.

Directory of Open Access Journals (Sweden)

Khan BahadarKhan

Full Text Available Diabetic Retinopathy (DR harm retinal blood vessels in the eye causing visual deficiency. The appearance and structure of blood vessels in retinal images play an essential part in the diagnoses of an eye sicknesses. We proposed a less computational unsupervised automated technique with promising results for detection of retinal vasculature by using morphological hessian based approach and region based Otsu thresholding. Contrast Limited Adaptive Histogram Equalization (CLAHE and morphological filters have been used for enhancement and to remove low frequency noise or geometrical objects, respectively. The hessian matrix and eigenvalues approach used has been in a modified form at two different scales to extract wide and thin vessel enhanced images separately. Otsu thresholding has been further applied in a novel way to classify vessel and non-vessel pixels from both enhanced images. Finally, postprocessing steps has been used to eliminate the unwanted region/segment, non-vessel pixels, disease abnormalities and noise, to obtain a final segmented image. The proposed technique has been analyzed on the openly accessible DRIVE (Digital Retinal Images for Vessel Extraction and STARE (STructured Analysis of the REtina databases along with the ground truth data that has been precisely marked by the experts.

Making environmental assessments of biomass production systems comparable worldwide

International Nuclear Information System (INIS)

Meyer, Markus A; Seppelt, Ralf; Priess, Joerg A; Witing, Felix

2016-01-01

Global demand for agricultural and forestry products fundamentally affects regional land-use change associated with environmental impacts (EIs) such as erosion. In contrast to aggregated global metrics such as greenhouse gas (GHG) balances, local/regional EIs of different agricultural and forestry production regions need methods which enable worldwide EI comparisons. The key aspect is to control environmental heterogeneity to reveal man-made differences of EIs between production regions. Environmental heterogeneity is the variation in biotic and abiotic environmental conditions. In the present study, we used three approaches to control environmental heterogeneity: (i) environmental stratification, (ii) potential natural vegetation (PNV), and (iii) regional environmental thresholds to compare EIs of solid biomass production. We compared production regions of managed forests and plantation forests in subtropical (Satilla watershed, Southeastern US), tropical (Rufiji basin, Tanzania), and temperate (Mulde watershed, Central Germany) climates. All approaches supported the comparison of the EIs of different land-use classes between and within production regions. They also standardized the different EIs for a comparison between the EI categories. The EIs for different land-use classes within a production region decreased with increasing degree of naturalness (forest, plantation forestry, and cropland). PNV was the most reliable approach, but lacked feasibility and relevance. The PNV approach explicitly included most of the factors that drive environmental heterogeneity in contrast to the stratification and threshold approaches. The stratification approach allows consistent global application due to available data. Regional environmental thresholds only included arbitrarily selected aspects of environmental heterogeneity; they are only available for few EIs. Especially, the PNV and stratification approaches are options to compare regional EIs of biomass or crop production

Resonances, cusp effects and a virtual state in e/sup -/-He scattering near the n = 3 thresholds. [Variational methods, resonance, threshold structures

Energy Technology Data Exchange (ETDEWEB)

Nesbet, R K [International Business Machines Corp., San Jose, Calif. (USA). Research Lab.

1978-01-14

Variational calculations locate and identify resonances and new threshold structures in electron impact excitation of He metastable states, in the region of the 3/sup 3/S and 3/sup 1/S excitation thresholds. A virtual state is found at the 3/sup 3/S threshold.

How extreme is enough to cause a threshold response of ecosystem

Science.gov (United States)

Niu, S.; Zhang, F.; Yang, Q.; Song, B.; Sun, J.

2017-12-01

Precipitation is a primary determinant of terrestrial ecosystem productivity over much of the globe. Recent studies have shown asymmetric or threshold responses of ecosystem productivity to precipitation gradient. However, it's not clear how extreme is enough to cause a threshold response of ecosystem. We conducted a global meta-analysis of precipitation experiments, a site level precipitation gradient experiment, and a remote sensing data mining on the relationship between precipitation extreme vs NDVI extreme. The meta-analysis shows that ANPP, BNPP, NEE, and other carbon cycle variables, showed similar response magnitudes to either precipitation increase or decrease when precipitation levels were normalized to the medium value of treatments (40%) across all the studies. Overall, the response ratios of these variables were linearly correlated with changes in precipitation amounts and soil water content. In the field gradient study with treatments of 1/12, 1/8. 1/4, 1/2, control, and 5/4 of ambient precipitation, the threshold of NPP, SR, NEE occurred when precipitation was reduced to the level of 1/8-1/12 of ambient precipitation. This means that only extreme drought can induce a threshold response of ecosystem. The regional remote sensing data showed that climate extremes with yearly low precipitation from 1982 to 2013 rarely cause extreme responses of vegetation, further suggesting that it is very difficult to detect threshold responses to natural climatic fluctuation. Our three studies together indicate that asymmetrical responses of vegetation to precipitation are likely detected, but only in very extreme precipitation events.

Near-Threshold Ionization of Argon by Positron Impact

Science.gov (United States)

Babij, T. J.; Machacek, J. R.; Murtagh, D. J.; Buckman, S. J.; Sullivan, J. P.

2018-03-01

The direct single-ionization cross section for Ar by positron impact has been measured in the region above the first ionization threshold. These measurements are compared to semiclassical calculations which give rise to a power law variation of the cross section in the threshold region. The experimental results appear to be in disagreement with extensions to the Wannier theory applied to positron impact ionization, with a smaller exponent than that calculated by most previous works. In fact, in this work, we see no difference in threshold behavior between the positron and electron cases. Possible reasons for this discrepancy are discussed.

Top-quark pair production near threshold

International Nuclear Information System (INIS)

Sumino, Y.; Fujii, K.; Hagiwara, K.; Murayama, H.; Ng, C.

1993-01-01

We present a novel formalism to calculate the total and the differential cross sections for heavy unstable top-quark pair production near threshold. Within the context of the nonrelativistic quark model, we introduce the running toponium width Γ FTHETA (E,p) in the Schroedinger equation for the three-point Green's function that governs the t bar t contribution to the e + e- annihilation process. The effect of the running of the width is found to be significant in two aspects: (i) it takes account of the phase-space volume for the decay process t bar t→bW + bar bW- and provides a consistent framework for calculating the differential cross sections; and (ii) it reduces the widths of the low-lying resonances to considerably less than 2Γ t (m t 2 ). Furthermore, the running of the width causes the total cross section to decrease significantly at c.m. energies below the first ''resonance'' enhancement, whereas it makes the ''peak'' cross section more distinct than is obtained in the fixed toponium width approximation. We use the two-loop-improved QCD potential in our calculation, and the α s (m Z ) Mbar S dependences of the total and differential cross sections are studied quantitatively, where M bar S denotes the modified minimal subtraction scheme. We find that the correlations in the α s and m t measurements are opposite in the total and differential cross sections, and the simultaneous measurements would lead to an accurate determination of both parameters

Genomic analysis of cow mortality and milk production using a threshold-linear model.

Science.gov (United States)

Tsuruta, S; Lourenco, D A L; Misztal, I; Lawlor, T J

2017-09-01

The objective of this study was to investigate the feasibility of genomic evaluation for cow mortality and milk production using a single-step methodology. Genomic relationships between cow mortality and milk production were also analyzed. Data included 883,887 (866,700) first-parity, 733,904 (711,211) second-parity, and 516,256 (492,026) third-parity records on cow mortality (305-d milk yields) of Holsteins from Northeast states in the United States. The pedigree consisted of up to 1,690,481 animals including 34,481 bulls genotyped with 36,951 SNP markers. Analyses were conducted with a bivariate threshold-linear model for each parity separately. Genomic information was incorporated as a genomic relationship matrix in the single-step BLUP. Traditional and genomic estimated breeding values (GEBV) were obtained with Gibbs sampling using fixed variances, whereas reliabilities were calculated from variances of GEBV samples. Genomic EBV were then converted into single nucleotide polymorphism (SNP) marker effects. Those SNP effects were categorized according to values corresponding to 1 to 4 standard deviations. Moving averages and variances of SNP effects were calculated for windows of 30 adjacent SNP, and Manhattan plots were created for SNP variances with the same window size. Using Gibbs sampling, the reliability for genotyped bulls for cow mortality was 28 to 30% in EBV and 70 to 72% in GEBV. The reliability for genotyped bulls for 305-d milk yields was 53 to 65% to 81 to 85% in GEBV. Correlations of SNP effects between mortality and 305-d milk yields within categories were the highest with the largest SNP effects and reached >0.7 at 4 standard deviations. All SNP regions explained less than 0.6% of the genetic variance for both traits, except regions close to the DGAT1 gene, which explained up to 2.5% for cow mortality and 4% for 305-d milk yields. Reliability for GEBV with a moderate number of genotyped animals can be calculated by Gibbs samples. Genomic

Schubert calculus and threshold polynomials of affine fusion

International Nuclear Information System (INIS)

Irvine, S.E.; Walton, M.A.

2000-01-01

We show how the threshold level of affine fusion, the fusion of Wess-Zumino-Witten (WZW) conformal field theories, fits into the Schubert calculus introduced by Gepner. The Pieri rule can be modified in a simple way to include the threshold level, so that calculations may be done for all (non-negative integer) levels at once. With the usual Giambelli formula, the modified Pieri formula deforms the tensor product coefficients (and the fusion coefficients) into what we call threshold polynomials. We compare them with the q-deformed tensor product coefficients and fusion coefficients that are related to q-deformed weight multiplicities. We also discuss the meaning of the threshold level in the context of paths on graphs

Photo-production of neutral kaons on C-12 in the threshold region

Czech Academy of Sciences Publication Activity Database

Watanabe, T.; Bydžovský, Petr; Dobashi, K.; Endo, S.; Fujii, Y.; Hashimoto, O.; Ishikawa, T.; Itoh, K.; Kanda, H.

2007-01-01

Roč. 651, č. 4 (2007), s. 269-274 ISSN 0370-2693 R&D Projects: GA ČR GA202/05/2142 Institutional research plan: CEZ:AV0Z10480505 Keywords : photo-production * neutral kaon * quasi-free reaction Subject RIV: BE - Theoretical Physics Impact factor: 4.189, year: 2007

Improvement of the drift chamber system in the SAPHIR detector and first measurements of the Φ meson production at threshold

International Nuclear Information System (INIS)

Scholmann, J.N.

1996-09-01

The SAPHIR detector at ELSA enables the measurement of photon induced Φ meson production from threshold up to 3 GeV in the full kinematical range. A considerable improvement of the drift chamber system is a precondition of gaining the necessary data rate in an acceptable time. The research focuses attention on the choice of the chamber gas and on a different mechanical construction, so as to minimize the negative influences of the photon beam crossing the sensitive volume of the drift chamber system. In addition, first preliminary results of the total and the differential cross section for the Φ meson production close to threshold were evaluated. (orig.)

Regional analysis of hardwood lumber production: 1963 - 2005

Science.gov (United States)

William Luppold; Matthew Bumgardner

2008-01-01

Between 1963 and 2005 hardwood lumber production in the eastern United States increased by more than 50%. Production more than doubled in the northeastern and north central regions while increasing by less than 25% in the southeastern and south central regions. Increased lumber production in the northern regions was facilitated by an expanding sawtimber inventory,...

Thresholding magnetic resonance images of human brain

Institute of Scientific and Technical Information of China (English)

Qing-mao HU; Wieslaw L NOWINSKI

2005-01-01

In this paper, methods are proposed and validated to determine low and high thresholds to segment out gray matter and white matter for MR images of different pulse sequences of human brain. First, a two-dimensional reference image is determined to represent the intensity characteristics of the original three-dimensional data. Then a region of interest of the reference image is determined where brain tissues are present. The non-supervised fuzzy c-means clustering is employed to determine: the threshold for obtaining head mask, the low threshold for T2-weighted and PD-weighted images, and the high threshold for T1-weighted, SPGR and FLAIR images. Supervised range-constrained thresholding is employed to determine the low threshold for T1-weighted, SPGR and FLAIR images. Thresholding based on pairs of boundary pixels is proposed to determine the high threshold for T2- and PD-weighted images. Quantification against public data sets with various noise and inhomogeneity levels shows that the proposed methods can yield segmentation robust to noise and intensity inhomogeneity. Qualitatively the proposed methods work well with real clinical data.

Taste perception with age: pleasantness and its relationships with threshold sensitivity and supra-threshold intensity of five taste qualities

NARCIS (Netherlands)

Mojet, J.; Christ-Hazelhof, E.; Heidema, J.

2005-01-01

The relationships between threshold sensitivity, supra-threshold intensity of NaCl, KCl, sucrose, aspartame, acetic acid, citric acid, caffeine, quinine HCl, monosodium glutamate (MSG) and inosine 5¿-monophosphate (IMP), and the pleasantness of these stimuli in products, were studied in 21 young

a Kinematically Complete Measurement of Positive Pion Production from Protons Near Threshold.

Science.gov (United States)

Hardie, John George

The total cross section for the reaction pp to pnpi^+ was measured at 294, 300, 307, 314, and 320 MeV. Angular distributions for the same reaction were measured at 294, 300 and 320 MeV. This is the first measurement of this reaction channel within 50 MeV of threshold. Study of pion production near threshold allows examination of the short range parts of the NN interaction, particularly the non-resonant partial waves. The data indicates that the contribution of p-waves to the pp to pnpi^+ reaction remains smaller than 20% up to 320 MeV. The total cross section data is compared to the theoretical calculations of Schillaci, Silbar and Young (1969) and Lee and Matsuyama (1987). Both reproduce some features of the data, but neither theory completely explains all the features of the data. There are no angular distribution predictions for comparison, but the data is symmetric around 90 degrees and appears to follow a 1+bcos^2theta _pi distribution, with the parameter b being consistent with zero for 294 MeV, about 0.05 at 300 MeV and about 0.18 at 320 MeV. This indicates that the higher partial waves are still weak at 320 MeV, although they are beginning to come into the reaction.

On resonance processes in near threshold excitation of resonance lines of Zn+ ion at electron-ion collisions

International Nuclear Information System (INIS)

Imre, A.I.; Gomonaj, A.N.; Vukstich, V.S.; Nemet, A.N.

1998-01-01

The results of spectroscopic investigation of resonances in excitation of near threshold region of separate components of resonance doublet 4p 2 P 1/2,3/2 0 of Zn + ion by electron impact are given in the present work. The physical basis of their production nature is suggested

Noise thresholds for optical quantum computers.

Science.gov (United States)

Dawson, Christopher M; Haselgrove, Henry L; Nielsen, Michael A

2006-01-20

In this Letter we numerically investigate the fault-tolerant threshold for optical cluster-state quantum computing. We allow both photon loss noise and depolarizing noise (as a general proxy for all local noise), and obtain a threshold region of allowed pairs of values for the two types of noise. Roughly speaking, our results show that scalable optical quantum computing is possible for photon loss probabilities <3 x 10(-3), and for depolarization probabilities <10(-4).

Determination of the threshold-energy surface for copper using in-situ electrical-resistivity measurements in the high-voltage electron microscope

International Nuclear Information System (INIS)

King, W.E.; Merkle, K.L.; Meshii, M.

1981-01-01

A detailed study of the anisotropy of the threshold energy for Frenkel-pair production in copper was carried out experimentally, using in-situ electrical-resistivity measurements in the high-voltage electron microscope. These electrical-resistivity measurements, which are sensitive to small changes in point-defect concentration, were used to determine the damage or defect production rate. Damage-rate measurements in copper single crystals were carried out for approx.40 incident electron-beam directions and six electron energies from 0.4 to 1.1 MeV. The total cross section for Frenkel-pair production is proportional to the measured damage rate and can be theoretically calculated if the form of the threshold-energy surface is known. Trial threshold-energy surfaces were systematically altered until a ''best fit'' of the calculated to the measured total cross sections for Frenkel-pair production was obtained. The average threshold energy of this surface is 28.5 eV. The minimum threshold energy is 18 +- 2 eV and is located near . A ring of very high threshold energy (>50 eV) surrounds the direction. A damage function for single-defect production was derived from this surface and was applied to defect-production calculations at higher recoil energies. This function rises rather sharply from a value of zero at 17 eV to 0.8 at 42 eV. It has the value of 0.5 at 24.5 eV. Above 30 eV the slope of the curve begins to decrease, reflecting the presence of the high-energy regions of the threshold-energy surface. Both topographical and quantitative comparisons of the present surface with those in the literature were presented. Based on a chi 2 goodness-of-fit test, the present surface was found to predict the experimentally observed total cross sections for Frenkel-pair production significantly better than the other available surfaces. Also, the goodness of fit varied substantially less with energy and direction for the present surface

Parton distributions with threshold resummation

CERN Document Server

Bonvini, Marco; Rojo, Juan; Rottoli, Luca; Ubiali, Maria; Ball, Richard D.; Bertone, Valerio; Carrazza, Stefano; Hartland, Nathan P.

2015-01-01

We construct a set of parton distribution functions (PDFs) in which fixed-order NLO and NNLO calculations are supplemented with soft-gluon (threshold) resummation up to NLL and NNLL accuracy respectively, suitable for use in conjunction with any QCD calculation in which threshold resummation is included at the level of partonic cross sections. These resummed PDF sets, based on the NNPDF3.0 analysis, are extracted from deep-inelastic scattering, Drell-Yan, and top quark pair production data, for which resummed calculations can be consistently used. We find that, close to threshold, the inclusion of resummed PDFs can partially compensate the enhancement in resummed matrix elements, leading to resummed hadronic cross-sections closer to the fixed-order calculation. On the other hand, far from threshold, resummed PDFs reduce to their fixed-order counterparts. Our results demonstrate the need for a consistent use of resummed PDFs in resummed calculations.

Threshold defect production in silicon determined by density functional theory molecular dynamics simulations

International Nuclear Information System (INIS)

Holmstroem, E.; Kuronen, A.; Nordlund, K.

2008-01-01

We studied threshold displacement energies for creating stable Frenkel pairs in silicon using density functional theory molecular dynamics simulations. The average threshold energy over all lattice directions was found to be 36±2 STAT ±2 SYST eV, and thresholds in the directions and were found to be 20±2 SYST eV and 12.5±1.5 SYST eV, respectively. Moreover, we found that in most studied lattice directions, a bond defect complex is formed with a lower threshold than a Frenkel pair. The average threshold energy for producing either a bond defect or a Frenkel pair was found to be 24±1 STAT ±2 SYST eV

Barrier heights of plutonium isotopes from (n,n'f)-thresholds

International Nuclear Information System (INIS)

Knitter, H.-H.; Budtz-Joergensen, C.

1983-01-01

The neutron induced second chance fission cross section for the isotopes 238 Pu, 239 Pu, 240 Pu, 241 Pu, 242 Pu and 244 Pu are studied in the region of the threshold using a simple model. Numerical values are obtained for the inner fission barrier heights of the mentioned isotopes and of the nuclear temperatures governing the neutron evaporation process at incident neutron energies around the second chance fission threshold. The comparisons of the present parameters with those obtained by other methods give hints to possible insufficiencies of experimental cross section data in the region of the second chance fission threshold. (Auth.)

Defining and evaluating heat stress thresholds in different dairy cow production systems

OpenAIRE

Brügemann, Kerstin; Gernand, Erhard; König von Borstel, Uta; König, Sven

2012-01-01

The aim of this study was to assess the impact of heat stress in dairy cows on test-day records for production traits and somatic cell score (SCS) in the state of Lower Saxony, Germany. Three different production systems were defined: A production system characterized by intensive crop production (=indoor housing), a pasture based production system, and a maritime region. Heat stress was assessed by two temperature-humidity indices (THI) modelled as random regression coefficients in an analys...

Productive performance of blackberry cultivars in altitude region

Directory of Open Access Journals (Sweden)

Jéssica de Oliveira

2017-11-01

Full Text Available ABSTRACT: Information on the production performance of blackberry in less colder regions are fundamentals to the expansion of the cultivated area and extension of management practices for cultivars adapted to climate conditions in Brazil. The research was carried out with the aim to evaluate the productive performance of different blackberries cultivars in altitude region of 1,387m with mild temperatures, situate at 18º14’56”S, 43º36’0”W, in Minas Gerais State, Brazil. It was carried during the seasons 2013/2014, 2014/2015 and 2015/2016. The blackberry cultivars evaluated were the following ones ‘Brazos’, ‘Guarani’, ‘Tupy’ and ‘Xavante’. Flowering and harvesting of cultivars were evaluated as well as climatological data of the area in order to relate the number of hours of accumulated cold less than 13°C, 10°C and 7.2°C with production and crop time. To determine the production, the mass of blackberries harvested per plant was measured. Production of blackberry cultivars was extended in altitude region with similar productivity to the other producing regions in Brazil. Productive performance of the cultivars varied according to the accumulation of cold hours with mild temperatures that occurred in cultivation region. ‘Brazos’, ‘Guarani’, ‘Tupy’ and ‘Xavante’ showed good adaptation, being ‘Brazos’ the cultivar most productive.

The threshold of cortical electrical stimulation for mapping sensory and motor functional areas.

Science.gov (United States)

Guojun, Zhang; Duanyu, Ni; Fu, Paul; Lixin, Cai; Tao, Yu; Wei, Du; Liang, Qiao; Zhiwei, Ren

2014-02-01

This study aimed to investigate the threshold of cortical electrical stimulation (CES) for functional brain mapping during surgery for the treatment of rolandic epilepsy. A total of 21 patients with rolandic epilepsy who underwent surgical treatment at the Beijing Institute of Functional Neurosurgery between October 2006 and March 2008 were included in this study. Their clinical data were retrospectively collected and analyzed. The thresholds of CES for motor response, sensory response, and after discharge production along with other threshold-related factors were investigated. The thresholds (mean ± standard deviation) for motor response, sensory response, and after discharge production were 3.48 ± 0.87, 3.86 ± 1.31, and 4.84 ± 1.38 mA, respectively. The threshold for after discharge production was significantly higher than those of both the motor and sensory response (both pstimulation frequency of 50 Hz and a pulse width of 0.2 ms, the threshold of sensory and motor responses were similar, and the threshold of after discharge production was higher than that of sensory and motor response. Copyright © 2013 Elsevier Ltd. All rights reserved.

Phenomenology of single-inclusive jet production with jet radius and threshold resummation

Science.gov (United States)

Liu, Xiaohui; Moch, Sven-Olaf; Ringer, Felix

2018-03-01

We perform a detailed study of inclusive jet production cross sections at the LHC and compare the QCD theory predictions based on the recently developed formalism for threshold and jet radius joint resummation at next-to-leading logarithmic accuracy to inclusive jet data collected by the CMS Collaboration at √{S }=7 and 13 TeV. We compute the cross sections at next-to-leading order in QCD with and without the joint resummation for different choices of jet radii R and observe that the joint resummation leads to crucial improvements in the description of the data. Comprehensive studies with different parton distribution functions demonstrate the necessity of considering the joint resummation in fits of those functions based on the LHC jet data.

Polarization of photoneutrons from the threshold region of 208Pb

International Nuclear Information System (INIS)

Holt, R.J.; Jackson, H.E.

1975-01-01

In order to determine the parities of several resonances in 208 Pb, the polarization of photoneutrons from the 208 Pb(γ,n(pol)) 207 Pb reaction was measured. This represents the first measurement of the polarization of photoneutrons from resonances near threshold. The observations are tabulated. (SDF)

Modeling DPOAE input/output function compression: comparisons with hearing thresholds.

Science.gov (United States)

Bhagat, Shaum P

2014-09-01

Basilar membrane input/output (I/O) functions in mammalian animal models are characterized by linear and compressed segments when measured near the location corresponding to the characteristic frequency. A method of studying basilar membrane compression indirectly in humans involves measuring distortion-product otoacoustic emission (DPOAE) I/O functions. Previous research has linked compression estimates from behavioral growth-of-masking functions to hearing thresholds. The aim of this study was to compare compression estimates from DPOAE I/O functions and hearing thresholds at 1 and 2 kHz. A prospective correlational research design was performed. The relationship between DPOAE I/O function compression estimates and hearing thresholds was evaluated with Pearson product-moment correlations. Normal-hearing adults (n = 16) aged 22-42 yr were recruited. DPOAE I/O functions (L₂ = 45-70 dB SPL) and two-interval forced-choice hearing thresholds were measured in normal-hearing adults. A three-segment linear regression model applied to DPOAE I/O functions supplied estimates of compression thresholds, defined as breakpoints between linear and compressed segments and the slopes of the compressed segments. Pearson product-moment correlations between DPOAE compression estimates and hearing thresholds were evaluated. A high correlation between DPOAE compression thresholds and hearing thresholds was observed at 2 kHz, but not at 1 kHz. Compression slopes also correlated highly with hearing thresholds only at 2 kHz. The derivation of cochlear compression estimates from DPOAE I/O functions provides a means to characterize basilar membrane mechanics in humans and elucidates the role of compression in tone detection in the 1-2 kHz frequency range. American Academy of Audiology.

Invited perspectives: Hydrological perspectives on precipitation intensity-duration thresholds for landslide initiation: proposing hydro-meteorological thresholds

Science.gov (United States)

Bogaard, Thom; Greco, Roberto

2018-01-01

Many shallow landslides and debris flows are precipitation initiated. Therefore, regional landslide hazard assessment is often based on empirically derived precipitation intensity-duration (ID) thresholds and landslide inventories. Generally, two features of precipitation events are plotted and labeled with (shallow) landslide occurrence or non-occurrence. Hereafter, a separation line or zone is drawn, mostly in logarithmic space. The practical background of ID is that often only meteorological information is available when analyzing (non-)occurrence of shallow landslides and, at the same time, it could be that precipitation information is a good proxy for both meteorological trigger and hydrological cause. Although applied in many case studies, this approach suffers from many false positives as well as limited physical process understanding. Some first steps towards a more hydrologically based approach have been proposed in the past, but these efforts received limited follow-up.Therefore, the objective of our paper is to (a) critically analyze the concept of precipitation ID thresholds for shallow landslides and debris flows from a hydro-meteorological point of view and (b) propose a trigger-cause conceptual framework for lumped regional hydro-meteorological hazard assessment based on published examples and associated discussion. We discuss the ID thresholds in relation to return periods of precipitation, soil physics, and slope and catchment water balance. With this paper, we aim to contribute to the development of a stronger conceptual model for regional landslide hazard assessment based on physical process understanding and empirical data.

Threshold Characteristics of Slow-Light Photonic Crystal Lasers

DEFF Research Database (Denmark)

Xue, Weiqi; Yu, Yi; Ottaviano, Luisa

2016-01-01

The threshold properties of photonic crystal quantum dot lasers operating in the slow-light regime are investigated experimentally and theoretically. Measurements show that, in contrast to conventional lasers, the threshold gain attains a minimum value for a specific cavity length. The experimental...... results are explained by an analytical theory for the laser threshold that takes into account the effects of slow light and random disorder due to unavoidable fabrication imperfections. Longer lasers are found to operate deeper into the slow-light region, leading to a trade-off between slow-light induced...

Threshold law for positron-atom impact ionisation

International Nuclear Information System (INIS)

Temkin, A.

1982-01-01

The threshold law for ionisation of atoms by positron impact is adduced in analogy with the author's approach to the electron-atom ionisation. It is concluded the Coulomb-dipole region of potential gives the essential part of the interaction in both cases and leads to the same kind of result: a modulated linear law. An additional process which enters positron ionisation is positronium formation in the continuum, but that will not dominate the threshold yield. The result is in sharp contrast to the positron threshold law as recently derived by Klar (J. Phys. B.; 14:4165 (1981)) on the basis of a Wannier-type (Phys. Rev.; 90:817 (1953)) analysis. (author)

Promotion and regional development. Implementation of regional productive development agencies. The case of Maule region, Chile

Directory of Open Access Journals (Sweden)

Enrique Yamil Alul González

2010-12-01

Full Text Available The Regional Productive Development Agencies implemented in Chile in 2006, were developed as a way to answer the longing desire to territorially decentralize, and that the own Regions be whom define their future. The Agencies have the responsibility to develop innovation and productive development Agendas in participative processes, which means with public, academic and private actors. Also, the Agencies have the mission to implement Competitive Improvement Plans-PMC (clusters in prioritized economic sectors by the own region. These PMC are leaded by private actors in each sector.

Sub-threshold excited Cl Kβ (K-V) x-ray fluorescence from CF3Cl molecule

International Nuclear Information System (INIS)

Perera, R.C.C.; Cowan, P.L.; Lindle, D.W.; LaVilla, R.E.

1987-10-01

With the availability of tunable synchrotron radiation sources, unoccupied molecular orbits (below vacuum level) can be selectively populated producing highly excited neutral molecules. X-ray fluorescence spectra from molecules were obtained with excitation below the ionization threshold and were observed to have significant intensity changes, absolute and relative energy position shifts and line width changes as compared to fluorescence spectra excited above the threshold. As an example, the Cl Kβ (K-V) emission spectra from CF 3 Cl vapor are presented. The energy shifts and intensity changes are explained in terms of perturbation effects due to the presence of an electron in an unoccupied molecular orbital. The narrow line widths obtained in the spectra excited below threshold are explained in terms of the ''effective'' hole production region in a core state limited by the broadening of the unoccupied level. The change in line widths as a function of below-threshold excitation energy is proposed as a novel technique to study the localized properties and reorganization effects of a hole in a core level. 10 refs., 4 figs., 1 tab

Applications of SCET to the pair production of supersymmetric particles at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Broggio, Alessandro

2013-02-04

In this thesis we investigate the phenomenology of supersymmetric particles at hadron colliders beyond next-to-leading order (NLO) in perturbation theory. We discuss the foundations of Soft-Collinear Effective Theory (SCET) and, in particular, we explicitly construct the SCET Lagrangian for QCD. As an example, we discuss factorization and resummation for the Drell-Yan process in SCET. We use techniques from SCET to improve existing calculations of the production cross sections for slepton-pair production and top-squark-pair production at hadron colliders. As a first application, we implement soft-gluon resummation at next-to-next-to-next-to-leading logarithmic order (NNNLL) for slepton-pair production in the minimal supersymmetric extension of the Standard Model (MSSM). This approach resums large logarithmic corrections arising from the dynamical enhancement of the partonic threshold region caused by steeply falling parton luminosities. We evaluate the resummed invariant-mass distribution and total cross section for slepton-pair production at the Tevatron and LHC and we match these results, in the threshold region, onto NLO fixed-order calculations. As a second application we present the most precise predictions available for top-squark-pair production total cross sections at the LHC. These results are based on approximate NNLO formulas in fixed-order perturbation theory, which completely determine the coefficients multiplying the singular plus distributions. The analysis of the threshold region is carried out in pair invariant mass (PIM) kinematics and in single-particle inclusive (1PI) kinematics. We then match our results in the threshold region onto the exact fixed-order NLO results and perform a detailed numerical analysis of the total cross section.

MODERNIZATION OF NATIONAL ECONOMY THROUGH DEVELOPMENT OF REGIONAL PRODUCTION INFRASTRUCTURE

Directory of Open Access Journals (Sweden)

T. G. Guilyadov

2011-01-01

Full Text Available Any region’s economy comprises production and non-production spheres which are interconnected and equivalent. Key part of any regional production sphere is its production infrastructure whose value is double: it defines the level of regional economic development on one hand, andinterrelation with the whole national economy on the other hand. The greatest and most important regional production infrastructure elements are transportation infrastructure, information/communication infrastructure and communal infrastructure. Analysis and solution of issues related to development of the basic regional production infrastructure elements as suggested in the article will be very useful for modernization of the national economy.

Melanin microcavitation threshold in the near infrared

Science.gov (United States)

Schmidt, Morgan S.; Kennedy, Paul K.; Vincelette, Rebecca L.; Schuster, Kurt J.; Noojin, Gary D.; Wharmby, Andrew W.; Thomas, Robert J.; Rockwell, Benjamin A.

2014-02-01

Thresholds for microcavitation of isolated bovine and porcine melanosomes were determined using single nanosecond (ns) laser pulses in the NIR (1000 - 1319 nm) wavelength regime. Average fluence thresholds for microcavitation increased non-linearly with increasing wavelength. Average fluence thresholds were also measured for 10-ns pulses at 532 nm, and found to be comparable to visible ns pulse values published in previous reports. Fluence thresholds were used to calculate melanosome absorption coefficients, which decreased with increasing wavelength. This trend was found to be comparable to the decrease in retinal pigmented epithelial (RPE) layer absorption coefficients reported over the same wavelength region. Estimated corneal total intraocular energy (TIE) values were determined and compared to the current and proposed maximum permissible exposure (MPE) safe exposure levels. Results from this study support the proposed changes to the MPE levels.

Sustainable production and consumption in a regional policy perspective

NARCIS (Netherlands)

Coenen, Franciscus H.J.M.

2004-01-01

One of the main challenges regions face in sustainable development is changing their production and consumption patterns. This paper focuses on the role of regional government in sustainable production and consumption polices, one of the specific topics in the framework of the European Regional

The generation of a lower threshold multiwavelength fiber laser in the L-band region assisted by a Sagnac loop mirror

International Nuclear Information System (INIS)

Aziz, Siti Narimah; Arsad, Norhana; Bakar, Ahmad Ashrif Abu; Elias, Sayidatul Nadia; Menon, P Sushita; Shaari, Sahbudin

2015-01-01

A low threshold multiwavelength laser generated with the assistance of a Sagnac loop mirror is proposed. Two simple ring cavity designs are studied, namely a standard design ring cavity (design A) and a ring cavity with a Sagnac loop mirror (design B). Design B, which integrates a Sagnac loop mirror together with a polarization controller, exhibits the most optimum performance, generating seven lasing modes. Using only a 40 mW pump power from the erbium-doped fiber amplifier (EDFA), design B is the preferred ring cavity design, as it successfully produces seven lasing modes simultaneously within a 0.42 nm channel spacing in the L-band region. The ring cavity is characterized by investigating the lasing threshold through the tuning output power of the EDFA, the percentages of extracted power and cavity loss. (paper)

Production below the threshold and reabsorption of neutral pions in the system 129Xe+197Au at 44 MeV/u

International Nuclear Information System (INIS)

Mayer, R.S.

1992-11-01

In the framework of the TAPS collaboration at GANIL an experiment for the production of neutral pions in 129 Xe+ 197 Au collisions below the threshold for the production in the free nucleon-nucleon collision was performed. Both for π 0 and for hard photons from the data the inclusive cross sections for the production, energy and angular distributions as well as the velocity of the emitting source were derived. (orig./HSI) [de

A high-Q low threshold thulium-doped silica microsphere laser in the 2 μm wavelength region designed for gas sensing applications

International Nuclear Information System (INIS)

Pal, Atasi; Chen, Shu Ying; Sun, Tong; Grattan, K T V; Sen, Ranjan

2013-01-01

A high-Q and low threshold laser resonator, operating in the 2 μm wavelength region, has been demonstrated by coupling a thulium-doped silica microsphere to a tapered fibre. Microspheres with diameters ranging from fifty to a few hundred micrometres were carefully fabricated for this purpose by melting an etched-clad thulium-doped silica fibre tip using a focused beam from a CO 2 laser, while the tapered fibre with waist diameter in the desired range of 2 μm was fabricated by using heating and stretching of standard single-mode telecommunication fibre. The tapered fibre served the dual purpose of transporting pump power into the sphere and allowing the extraction of the resulting laser emission. Under excitation at a wavelength of ∼1.6 μm, lasing occurred at wavelengths over the range from 1.9 to 2.0 μm. Single-mode laser operation was obtained by exciting the fundamental whispering gallery mode resonance of the microsphere, while multi-mode lasing occurred for non-fundamental mode excitation. The threshold power of the laser was measured to be about 50 μW delivered pump power, and a maximum laser power of 0.8 mW at around 1.94 μm was observed for a 6 mW pump power, operating at wavelengths around 1.6 μm. The laser was designed as a low threshold and compact source for miniaturized gas sensing devices operating over this important wavelength region. (letter)

High-resolution modeling of thermal thresholds and environmental influences on coral bleaching for local and regional reef management.

Science.gov (United States)

Kumagai, Naoki H; Yamano, Hiroya

2018-01-01

Coral reefs are one of the world's most threatened ecosystems, with global and local stressors contributing to their decline. Excessive sea-surface temperatures (SSTs) can cause coral bleaching, resulting in coral death and decreases in coral cover. A SST threshold of 1 °C over the climatological maximum is widely used to predict coral bleaching. In this study, we refined thermal indices predicting coral bleaching at high-spatial resolution (1 km) by statistically optimizing thermal thresholds, as well as considering other environmental influences on bleaching such as ultraviolet (UV) radiation, water turbidity, and cooling effects. We used a coral bleaching dataset derived from the web-based monitoring system Sango Map Project, at scales appropriate for the local and regional conservation of Japanese coral reefs. We recorded coral bleaching events in the years 2004-2016 in Japan. We revealed the influence of multiple factors on the ability to predict coral bleaching, including selection of thermal indices, statistical optimization of thermal thresholds, quantification of multiple environmental influences, and use of multiple modeling methods (generalized linear models and random forests). After optimization, differences in predictive ability among thermal indices were negligible. Thermal index, UV radiation, water turbidity, and cooling effects were important predictors of the occurrence of coral bleaching. Predictions based on the best model revealed that coral reefs in Japan have experienced recent and widespread bleaching. A practical method to reduce bleaching frequency by screening UV radiation was also demonstrated in this paper.

Rational allocation of agricultural production in the region

Directory of Open Access Journals (Sweden)

Grigorii Mikhailovich Semyashkin

2015-05-01

Full Text Available The paper proposes an original approach to determining the optimal allocation of agricultural production in the region; the approach includes the methodological substantiation of the necessity to differentiate consumers when addressing food security issues in the region. It was proposed to allocate three levels: level 1 – the provision of food to socially vulnerable layers, level 2 – the provision with food at the subsistence level, and level 3 – the provision of the total population of the region with food. A preliminary forecast was made for each municipality; it analyzed possible changes in the number of the socially vulnerable up to 2020; in accordance with medical standards and norms of the subsistence level the volumes of food were calculated, which in turn were compared with the actual production output. The difference between the actual volume and the volume of evidence-based requirements represented the very increase in the volume of production, the achievement of which requires certain investments on the basis of capital-output ratio. After that the regional market was divided into three sub-regional markets depending on distance, number of consumers and suppliers. This allowed us to calculate the amount of transport costs based on the type and lot size of the transported product, taking into account the distance to each sub-market. As a criterion of transportation expediency we took into account the share of transport costs in the price of the product not exceeding 30%. Otherwise, it is required to concentrate the production in order to increase the lot transported or to carry out a deeper processing of the product. The proposed methodology served as the basis for choosing the most effective option of spatial location of agricultural production

Does FDI promote regional development? Evidence from local and regional productivity spillovers in Greece

Directory of Open Access Journals (Sweden)

Vassilis MONASTIRIOTIS

2010-12-01

Full Text Available Studies on the productivity spillovers of FDI have concentrated on the nationalsectoral level. As a result, little is known about the impact of FDI on absolute and relative regional economic performance. In this paper we examine this issue by relying on a unique dataset of over 20,000 Greek firms for the period 2002-2006 covering all sectors of economic activity. We examine the spatial distribution of foreign-owned firms in the country and analyse the effect that their presence – at the local, regional and national levels – has on the productivity of domestic firms. We find strong evidence suggesting that foreignowned firms self-select into regions and sectors of high productivity. Net of this selection effect, the impact of foreign presence on domestic productivity is negative – although at the very local level some positive spillover effects are identifiable. The bulk of the effects concentrate in non-manufacturing activities, high-tech sectors, and medium-sized high-productivity firms. Importantly, this effect is not constant across space however. Productivity spillovers tend to be negative in the regions hosting the main urban areas in the country but positive in smaller and more peripheral regions. In this way, despite the tendency of FDI to concentrate in a limited number of areas within the country – those of the highest level of development – the externalities that FDI activity generates to the local economies appear to be of a rather equilibrating character.

Baryon-antibaryon threshold and ω-baryonium mixing

International Nuclear Information System (INIS)

Gavai, R.V.

1981-01-01

It is shown that in any dual-topological-unitarization model of ω-baryonium (B) mixing at the cylinder level, in which the production of baryon-antibaryon (bb-bar) pairs can take place only above a certain threshold energy, the phenomenologically relevant ω and B trajectories do not mix below bb-bar threshold. However, their couplings to external particles do get modified. The ω-B mixing angle theta/sub omegahyphenB/, which characterizes these coupling modification effects below bb-bar threshold at t = 0, is estimated in some models. These estimates are found to agree reasonably well with the existing phenomenological bound on theta/sub omegahyphenB/

Partitioning into hazard subregions for regional peaks-over-threshold modeling of heavy precipitation

Science.gov (United States)

Carreau, J.; Naveau, P.; Neppel, L.

2017-05-01

The French Mediterranean is subject to intense precipitation events occurring mostly in autumn. These can potentially cause flash floods, the main natural danger in the area. The distribution of these events follows specific spatial patterns, i.e., some sites are more likely to be affected than others. The peaks-over-threshold approach consists in modeling extremes, such as heavy precipitation, by the generalized Pareto (GP) distribution. The shape parameter of the GP controls the probability of extreme events and can be related to the hazard level of a given site. When interpolating across a region, the shape parameter should reproduce the observed spatial patterns of the probability of heavy precipitation. However, the shape parameter estimators have high uncertainty which might hide the underlying spatial variability. As a compromise, we choose to let the shape parameter vary in a moderate fashion. More precisely, we assume that the region of interest can be partitioned into subregions with constant hazard level. We formalize the model as a conditional mixture of GP distributions. We develop a two-step inference strategy based on probability weighted moments and put forward a cross-validation procedure to select the number of subregions. A synthetic data study reveals that the inference strategy is consistent and not very sensitive to the selected number of subregions. An application on daily precipitation data from the French Mediterranean shows that the conditional mixture of GPs outperforms two interpolation approaches (with constant or smoothly varying shape parameter).

Strategy of Trade-Reliable Featured Product Supporting Regional Innovation Systems

Science.gov (United States)

Riskiawan, H. Y.; Purnomo, B. H.; Abdurahman, A.; Hariono, B.; Puspitasari, T. D.

2018-01-01

Pacitan, Ponorogo, and Magetan had planned the development of featured products as contained in the Medium Term Development Plan (MTDP) until 2020. The focus of development is almost similar to featured products derived from agribusiness, food processing, handycrafts, and tourism. The geographical proximity results characteristics of natural resources and social culture have similarities, including the type of featured products, constraints, problems, and opportunities for development. Given the characteristics and the support system of some featured products contained in these three regions have a lot in common and their functional interactions involving actors from across the region, it is necessary to develop cross-jurisdictional policy. The resulting strategy should be able to support the development of Regional Innovation System (RIS). The purpose of this research is 1) Determining featured product cross-regional between Pacitan regency; Ponorogo and Magetan districts in support of RIS development; and 2) Designing a featured product development strategy using supply chain management in order to drive the local economy. Based on the results of research conducted, featured products across the region that have potentiality to be developed are: processed products of “janggelan” leather products, and woven bamboo.

Thresholds for decision-making: informing the cost-effectiveness and affordability of rotavirus vaccines in Malaysia.

Science.gov (United States)

Loganathan, Tharani; Ng, Chiu-Wan; Lee, Way-Seah; Hutubessy, Raymond C W; Verguet, Stéphane; Jit, Mark

2018-03-01

Cost-effectiveness thresholds (CETs) based on the Commission on Macroeconomics and Health (CMH) are extensively used in low- and middle-income countries (LMICs) lacking locally defined CETs. These thresholds were originally intended for global and regional prioritization, and do not reflect local context or affordability at the national level, so their value for informing resource allocation decisions has been questioned. Using these thresholds, rotavirus vaccines are widely regarded as cost-effective interventions in LMICs. However, high vaccine prices remain a barrier towards vaccine introduction. This study aims to evaluate the cost-effectiveness, affordability and threshold price of universal rotavirus vaccination at various CETs in Malaysia. Cost-effectiveness of Rotarix and RotaTeq were evaluated using a multi-cohort model. Pan American Health Organization Revolving Fund's vaccine prices were used as tender price, while the recommended retail price for Malaysia was used as market price. We estimate threshold prices defined as prices at which vaccination becomes cost-effective, at various CETs reflecting economic theories of human capital, societal willingness-to-pay and marginal productivity. A budget impact analysis compared programmatic costs with the healthcare budget. At tender prices, both vaccines were cost-saving. At market prices, cost-effectiveness differed with thresholds used. At market price, using 'CMH thresholds', Rotarix programmes were cost-effective and RotaTeq were not cost-effective from the healthcare provider's perspective, while both vaccines were cost-effective from the societal perspective. Using other CETs, both vaccines were not cost-effective at market price, from the healthcare provider's and societal perspectives. At tender and cost-effective prices, rotavirus vaccination cost ∼1 and 3% of the public health budget, respectively. Using locally defined thresholds, rotavirus vaccination is cost-effective at vaccine prices in line

Introducing Alternative-Based Thresholding for Defining Functional Regions of Interest in fMRI

Directory of Open Access Journals (Sweden)

Jasper Degryse

2017-04-01

Full Text Available In fMRI research, one often aims to examine activation in specific functional regions of interest (fROIs. Current statistical methods tend to localize fROIs inconsistently, focusing on avoiding detection of false activation. Not missing true activation is however equally important in this context. In this study, we explored the potential of an alternative-based thresholding (ABT procedure, where evidence against the null hypothesis of no effect and evidence against a prespecified alternative hypothesis is measured to control both false positives and false negatives directly. The procedure was validated in the context of localizer tasks on simulated brain images and using a real data set of 100 runs per subject. Voxels categorized as active with ABT can be confidently included in the definition of the fROI, while inactive voxels can be confidently excluded. Additionally, the ABT method complements classic null hypothesis significance testing with valuable information by making a distinction between voxels that show evidence against both the null and alternative and voxels for which the alternative hypothesis cannot be rejected despite lack of evidence against the null.

Hidrogenionic potential (pH of the attractant, trap density and control threshold for Ceratitis capitata (DIPTERA: TEPHRITIDAE on Hamlin oranges in São Paulo central region, Brazil

Directory of Open Access Journals (Sweden)

Paulo Eduardo Branco Paiva

2013-06-01

Full Text Available This study evaluated the effect of initial pH values of 4.5, 6.5 and 8.5 of the attractant (protein bait Milhocina® and borax (sodium borate in the field, on the capture of fruit flies in McPhail traps, using 1, 2, 4 and 8 traps per hectare, in order to estimate control thresholds in a Hamlin orange grove in the central region of the state of São Paulo. The most abundant fruit fly species was Ceratitis capitata, comprising almost 99% of the fruit flies captured, of which 80% were females. The largest captures of C. capitata were found in traps baited with Milhocina® and borax at pH 8.5. Captures per trap for the four densities were similar, indicating that the population can be estimated with one trap per hectare in areas with high populations. It was found positive relationships between captures of C. capitata and the number of Hamlin oranges damaged, 2 and 3 weeks after capture. It was obtained equations that correlate captures and damage levels which can be used to estimate control thresholds. The average loss caused in Hamlin orange fruits by C. capitata was 2.5 tons per hectare or 7.5% of production.

Test of the linear-no threshold theory of radiation carcinogenesis for inhaled radon decay products

International Nuclear Information System (INIS)

Cohen, B.L.

1995-01-01

Data on lung cancer mortality rates vs. average radon concentration in homes for 1,601 U.S. counties are used to test the linear-no threshold theory. The widely recognized problems with ecological studies, as applied to this work, are addressed extensively. With or without corrections for variations in smoking prevalence, there is a strong tendency for lung cancer rates to decrease with increasing radon exposure, in sharp contrast to the increase expected from the theory. The discrepancy in slope is about 20 standard deviations. It is shown that uncertainties in lung cancer rates, radon exposures, and smoking prevalence are not important and that confounding by 54 socioeconomic factors, by geography, and by altitude and climate can explain only a small fraction of the discrepancy. Effects of known radon-smoking prevalence correlations - rural people have higher radon levels and smoke less than urban people, and smokers are exposed to less radon than non-smokers - are calculated and found to be trivial. In spite of extensive efforts, no potential explanation for the discrepancy other than failure of the linear-no threshold theory for carcinogenesis from inhaled radon decay products could be found. (author)

Possible experimental studies of the t anti t threshold region at 250--500 GeV e+e- collider

International Nuclear Information System (INIS)

Komamiya, Sachio.

1991-01-01

A possible measurement of the top quark mass by an energy scan of the t anti t threshold region at e + e - colliders of √s = 250--500 GeV is discussed. With an integrated luminosity of 1 fb -1 devoted to the energy scan, a top quark mass of about 150 GeV can be determined with an accuracy of ∼0.3 GeV, with a comparable systematic uncertainty arising from the few % errors in the α s measurement at LEP-I. The possibilities of studying Γ t and Higgs boson effects are also discussed. 10 refs., 12 figs., 4 tabs

The Regional Heterogeneity of Productivity Determinants: Evidence from Ukrainian Firms

Directory of Open Access Journals (Sweden)

Cieślik Andrzej

2017-03-01

Full Text Available This paper studies the determinants of the total factor productivity (TFP for Ukrainian firms in the manufacturing sector across macro-regions using recent micro-level datasets for 2013. Our empirical results show some degree of heterogeneity across Ukrainian macro-regions; in particular, the link between the total factor productivity, firm size, imports and the level of competition seems to be valid for all macro regions. However, the effects of private ownership status, capital intensity and exports seems to be region specific. In addition, we found no relationship between firm productivity and foreign ownership for any of the regions.

Hydrometeorological threshold conditions for debris flow initiation in Norway

Directory of Open Access Journals (Sweden)

N. K. Meyer

2012-10-01

Full Text Available Debris flows, triggered by extreme precipitation events and rapid snow melt, cause considerable damage to the Norwegian infrastructure every year. To define intensity-duration (ID thresholds for debris flow initiation critical water supply conditions arising from intensive rainfall or snow melt were assessed on the basis of daily hydro-meteorological information for 502 documented debris flow events. Two threshold types were computed: one based on absolute ID relationships and one using ID relationships normalized by the local precipitation day normal (PDN. For each threshold type, minimum, medium and maximum threshold values were defined by fitting power law curves along the 10th, 50th and 90th percentiles of the data population. Depending on the duration of the event, the absolute threshold intensities needed for debris flow initiation vary between 15 and 107 mm day⁻¹. Since the PDN changes locally, the normalized thresholds show spatial variations. Depending on location, duration and threshold level, the normalized threshold intensities vary between 6 and 250 mm day⁻¹. The thresholds obtained were used for a frequency analysis of over-threshold events giving an estimation of the exceedance probability and thus potential for debris flow events in different parts of Norway. The absolute thresholds are most often exceeded along the west coast, while the normalized thresholds are most frequently exceeded on the west-facing slopes of the Norwegian mountain ranges. The minimum thresholds derived in this study are in the range of other thresholds obtained for regions with a climate comparable to Norway. Statistics reveal that the normalized threshold is more reliable than the absolute threshold as the former shows no spatial clustering of debris flows related to water supply events captured by the threshold.

Color image Segmentation using automatic thresholding techniques

International Nuclear Information System (INIS)

Harrabi, R.; Ben Braiek, E.

2011-01-01

In this paper, entropy and between-class variance based thresholding methods for color images segmentation are studied. The maximization of the between-class variance (MVI) and the entropy (ME) have been used as a criterion functions to determine an optimal threshold to segment images into nearly homogenous regions. Segmentation results from the two methods are validated and the segmentation sensitivity for the test data available is evaluated, and a comparative study between these methods in different color spaces is presented. The experimental results demonstrate the superiority of the MVI method for color image segmentation.

Computer simulation study of the displacement threshold-energy surface in Cu

International Nuclear Information System (INIS)

King, W.E.; Benedek, R.

1981-01-01

Computer simulations were performed using the molecular-dynamics technique to determine the directional dependence of the threshold energy for production of stable Frenkel pairs in copper. Sharp peaks were observed in the simulated threshold energy surface in between the low-index directions. Threshold energies ranged from approx.25 eV for directions near or to 180 eV at the position of the peak between and . The general topographical features of the simulated threshold-energy surface are in good agreement with those determined from an analysis of recent experiments by King et al. on the basis of a Frenkel-pair resistivity rho/sub F/ = 2.85 x 10 -4 Ω cm. Evidence is presented in favor of this number as opposed to the usually assumed value, rho/sub F/ = 2.00 x 10 -4 Ω cm. The energy dependence of defect production in a number of directions was investigated to determine the importance of nonproductive events above threshold

Measurements of NN → dπ near threshold

International Nuclear Information System (INIS)

Hutcheon, D.A.

1990-09-01

New, precise measurements of the differential cross sections for np → dπ 0 and π + d → pp and of analyzing powers for pp → dπ + have been made at energies within 10 MeV (c.m.) of threshold. They allow the pion s-wave and p-wave parts of the production strength to be distinguished unambiguously, yielding an s-wave strength at threshold which is significantly smaller than the previously accepted value. There is no evidence for charge independence breaking nor for πNN resonances near threshold. (Author) (17 refs., 17 figs., tab.)

The threshold photoelectron spectrum of mercury

International Nuclear Information System (INIS)

Rojas, H; Dawber, G; Gulley, N; King, G C; Bowring, N; Ward, R

2013-01-01

The threshold photoelectron spectrum of mercury has been recorded over the energy range (10–40 eV) which covers the region from the lowest state of the singly charged ion, 5d 10 6s( 2 S 1/2 ), to the double charged ionic state, 5d 9 ( 2 D 3/2 )6s( 1 D 2 ). Synchrotron radiation has been used in conjunction with the penetrating-field threshold-electron technique to obtain the spectrum with high resolution. The spectrum shows many more features than observed in previous photoemission measurements with many of these assigned to satellite states converging to the double ionization limit. (paper)

Location and regional productive specialization in Colombia

Directory of Open Access Journals (Sweden)

Henry Antonio Mendoza Tolosa

2017-03-01

Full Text Available This document is directed to responding if Colombian regional economies restructured their productive activities from 2000 to 2014, and if so, illustrate the way that process has been effective in the different departments from the results and dynamics of their economic activities. For developing this exercise, we used a set of statistical indicators of spatial geography, among which is the factorial analysis, specifically the method of principal components, whose purpose was to identify the set activities whose performance explains more clearly the productive orientation of the departments, and complementary synthetic regional specialization indexes were employed in order to identify the degree and the changes of economic diversification, presented in those indicators. The results of this research shows that most of the Colombian regions have diversified their economic activity, with focus on service activities, among which are representative government and non-market services produced by those institutions, nowadays less dependent on few sources of growth. However, in other regions the primary sector, mainly mining activity, for many years has been the most important activity of production structures, affecting the process of full diversification, which is close to current local demands and international economic order the requests with greater intensity.

Critical issues of alcohol safety in the region

OpenAIRE

Svetlana Vasil’evna Aksyutina; Natal’ya Mikhailovna Ovsyankina

2015-01-01

The paper presents results of the research into the economic and socio-demographic indicators associated with the production and consumption of alcoholic beverages. It discloses the analysis of the alcoholic beverage market structure in the Vologda Oblast. The authors have identified the threshold of the safe alcohol production volume in the region taking into account the World Health Organization standards of alcohol consumption and the share of illegally produced goods. The article states t...

Adiabatic theory of Wannier threshold laws and ionization cross sections

International Nuclear Information System (INIS)

Macek, J.H.; Ovchinnikov, S.Y.

1994-01-01

Adiabatic energy eigenvalues of H 2 + are computed for complex values of the internuclear distance R. The infinite number of bound-state eigenenergies are represented by a function ε(R) that is single valued on a multisheeted Riemann surface. A region is found where ε(R) and the corresponding eigenfunctions exhibit harmonic-oscillator structure characteristic of electron motion on a potential saddle. The Schroedinger equation is solved in the adiabatic approximation along a path in the complex R plane to compute ionization cross sections. The cross section thus obtained joins the Wannier threshold region with the keV energy region, but the exponent near the ionization threshold disagrees with well-accepted values. Accepted values are obtained when a lowest-order diabatic correction is employed, indicating that adiabatic approximations do not give the correct zero velocity limit for ionization cross sections. Semiclassical eigenvalues for general top-of-barrier motion are given and the theory is applied to the ionization of atomic hydrogen by electron impact. The theory with a first diabatic correction gives the Wannier threshold law even for this case

Inelastic electron scattering from 3He and 4He in the threshold region at high momentum transfer

International Nuclear Information System (INIS)

Rock, S.; Arnold, R.G.; Chertok, B.T.; Szalata, Z.M.; Day, D.; McCarthy, J.S.; Martin, F.; Mecking, B.A.; Sick, I.; Tamas, G.

1981-01-01

The cross section for inclusive inelastic electron scattering from the helium isotopes has been measured at momentum transfers squared of 0.8 less than or equal to Q 2 less than or equal to 5.0 (GeV/c) 2 for 3 He and 0.8 less than or equal to Q 2 less than or equal to 2.4 (GeV/c) 2 for 4 He. The data were taken at 10 0 and cover the range 1.0 2 /2M/sub He/ν, which includes the elastic peak, nuclear breakup threshold, the high momentum tail of the quasi elastic scattering, and pion production. The structure function, νW 2 , derived from the data is approaching a scaling limit at high Q 2 . It can be factored into a product of functions of Q 2 and of x as predicted by some models

Non-abelian factorisation for next-to-leading-power threshold logarithms

NARCIS (Netherlands)

Bonocore, D.; Laenen, E.; Magnea, L.; Vernazza, L.; White, C.D.

2016-01-01

Soft and collinear radiation is responsible for large corrections to many hadronic cross sections, near thresholds for the production of heavy final states. There is much interest in extending our understanding of this radiation to next-to-leading power (NLP) in the threshold expansion. In this

Dynamical fusion thresholds in macroscopic and microscopic theories

International Nuclear Information System (INIS)

Davies, K.T.R.; Sierk, A.J.; Nix, J.R.

1983-01-01

Macroscopic and microscopic results demonstrating the existence of dynamical fusion thresholds are presented. For macroscopic theories, it is shown that the extra-push dynamics is sensitive to some details of the models used, e.g. the shape parametrization and the type of viscosity. The dependence of the effect upon the charge and angular momentum of the system is also studied. Calculated macroscopic results for mass-symmetric systems are compared to experimental mass-asymmetric results by use of a tentative scaling procedure, which takes into account both the entrance-channel and the saddle-point regions of configuration space. Two types of dynamical fusion thresholds occur in TDHF studies: (1) the microscopic analogue of the macroscopic extra push threshold, and (2) the relatively high energy at which the TDHF angular momentum window opens. Both of these microscopic thresholds are found to be very sensitive to the choice of the effective two-body interaction

Threshold and resilience management of coupled urbanization and water environmental system in the rapidly changing coastal region

International Nuclear Information System (INIS)

Li, Yangfan; Li, Yi; Wu, Wei

2016-01-01

The concept of thresholds shows important implications for environmental and resource management. Here we derived potential landscape thresholds which indicated abrupt changes in water quality or the dividing points between exceeding and failing to meet national surface water quality standards for a rapidly urbanizing city on the Eastern Coast in China. The analysis of landscape thresholds was based on regression models linking each of the seven water quality variables to each of the six landscape metrics for this coupled land-water system. We found substantial and accelerating urban sprawl at the suburban areas between 2000 and 2008, and detected significant nonlinear relations between water quality and landscape pattern. This research demonstrated that a simple modeling technique could provide insights on environmental thresholds to support more-informed decision making in land use, water environmental and resilience management. - Graphical abstract: Fig. Threshold models and resilience management for water quality. Display Omitted - Highlights: • Coupling urbanization and water environmental system. • Developing threshold models of the coupled land-water systems. • Nonlinear relations between water quality variables and landscape metrics. • Enhancing resilience management of coastal rapid urbanization. - We develop environmental threshold models and provide their implications on resilience management for a coupled land-water system with rapid urbanization.

Threshold resummation and higher order effects in QCD

International Nuclear Information System (INIS)

Ringer, Felix Maximilian

2015-01-01

Quantum chromodynamics (QCD) is a quantum field theory that describes the strong interactions between quarks and gluons, the building blocks of all hadrons. Thanks to the experimental progress over the past decades, there has been an ever-growing need for QCD precision calculations for scattering processes involving hadrons. For processes at large momentum transfer, perturbative QCD offers a systematic approach for obtaining precise predictions. This approach relies on two key concepts: the asymptotic freedom of QCD and factorization. In a perturbative calculation at higher orders, the infrared cancellation between virtual and real emission diagrams generally leaves behind logarithmic contributions. In many observables relevant for hadronic scattering these logarithms are associated with a kinematic threshold and are hence known as ''threshold logarithms''. They become large when the available phase space for real gluon emission shrinks. In order to obtain a reliable prediction from QCD, the threshold logarithms need to be taken into account to all orders in the strong coupling constant, a procedure known as ''threshold resummation''. The main focus of my PhD thesis is on studies of QCD threshold resummation effects beyond the next-to-leading logarithmic order. Here we primarily consider the production of hadron pairs in hadronic collisions as an example. In addition, we also consider hadronic jet production, which is particularly interesting for the phenomenology at the LHC. For both processes, we fully take into account the non-trivial QCD color structure of the underlying partonic hard- scattering cross sections. We find that threshold resummation leads to sizable numerical effects in the kinematic regimes relevant for comparisons to experimental data.

Active Pesticide Production Points, Region 9, 2013, US EPA Region 9

Data.gov (United States)

U.S. Environmental Protection Agency — This data layer represents Active Pesticide Producing Establishments in USEPA Region 9 (AZ, CA, HI and NV) that reported production for the year 2013. Pesticide...

Summary report of a workshop on establishing cumulative effects thresholds : a suggested approach for establishing cumulative effects thresholds in a Yukon context

International Nuclear Information System (INIS)

2003-01-01

Increasingly, thresholds are being used as a land and cumulative effects assessment and management tool. To assist in the management of wildlife species such as woodland caribou, the Department of Indian and Northern Affairs (DIAND) Environment Directorate, Yukon sponsored a workshop to develop and use cumulative thresholds in the Yukon. The approximately 30 participants reviewed recent initiatives in the Yukon and other jurisdictions. The workshop is expected to help formulate a strategic vision for implementing cumulative effects thresholds in the Yukon. The key to success resides in building relationships with Umbrella Final Agreement (UFA) Boards, the Development Assessment Process (DAP), and the Yukon Environmental and Socio-Economic Assessment Act (YESAA). Broad support is required within an integrated resource management framework. The workshop featured discussions on current science and theory of cumulative effects thresholds. Potential data and implementation issues were also discussed. It was concluded that thresholds are useful and scientifically defensible. The threshold research results obtained in Alberta, British Columbia and the Northwest Territories are applicable to the Yukon. One of the best tools for establishing and tracking thresholds is habitat effectiveness. Effects must be monitored and tracked. Biologists must share their information with decision makers. Interagency coordination and assistance should be facilitated through the establishment of working groups. Regional land use plans should include thresholds. 7 refs.

The development of regional markets of eggs production in Russia

Directory of Open Access Journals (Sweden)

Natal'ya Anatol'evna Alekseeva

2011-12-01

Full Text Available The current state of regional markets development and the production of eggs and egg products for a long period — from 1990 to 2009 — is reviewed in this paper. The main research method is the method of statistical groupings. The variable amount of egg production was chosen as the grouping characteristic, since this figure fits well into research goals and has the property of the prevalence in the aggregate / total. To analyze the trends of the Russian regional markets involved into egg production, official statistics on consumer prices was used as well as producer prices, the volume of egg production per capita based on food import and export products. This allowed to group regions for comparison with average values of indicators carried out by different criteria, and to draw conclusions about trends in the development of regional markets. The most relevant factors influencing the development of egg production, among which the factor of vertical integration of production was especially noticed: building own plants and feed mills, joining the land in order to ensure the needs for higher quality raw materials and other activities were identified.

Testing for a Debt-Threshold Effect on Output Growth.

Science.gov (United States)

Lee, Sokbae; Park, Hyunmin; Seo, Myung Hwan; Shin, Youngki

2017-12-01

Using the Reinhart-Rogoff dataset, we find a debt threshold not around 90 per cent but around 30 per cent, above which the median real gross domestic product (GDP) growth falls abruptly. Our work is the first to formally test for threshold effects in the relationship between public debt and median real GDP growth. The null hypothesis of no threshold effect is rejected at the 5 per cent significance level for most cases. While we find no evidence of a threshold around 90 per cent, our findings from the post-war sample suggest that the debt threshold for economic growth may exist around a relatively small debt-to-GDP ratio of 30 per cent. Furthermore, countries with debt-to-GDP ratios above 30 per cent have GDP growth that is 1 percentage point lower at the median.

Retinal hemorrhage thresholds for Q-switched neodymium-Yag laser exposures

Energy Technology Data Exchange (ETDEWEB)

Blankenstein, M.F.; Zuclich, J.; Allen, R.G.; Davis, H.; Thomas, S.J.; Harrison, R.F.

1986-07-01

Thresholds for retinal vitreal and contained hemorrhages were determined for 1064 nm laser light at 30-nsec and 4-nsec pulsewidths. Rhesus monkeys received graded exposures from a neodymium-yag laser onto either the macular or extramacular region of the retina. Contained hemorrhages appeared as concentric ring structures with white punctate centers. The vitreal hemorrhage was characterized by the presence of choroidal blood in the vitreal chamber at the exposure site. The 30-nsec contained hemorrhage threshold (ED50) was 1.7 mJ on the macula and 2.1 mJ for an extramacular exposure. The 30-nsec vitreal hemorrhage macular threshold was 2.3 mJ, and the extramacular threshold was 6.6 mJ. The threshold for the 4-nsec pulsewidths to produce a hemorrhage (vitreal or contained) on the retina (macula or extramacular) was 340 microJ.

Retinal-hemorrhage thresholds for Q-switched neodymium-YAG laser exposures

Energy Technology Data Exchange (ETDEWEB)

Blankenstein, M.F.; Zuclich; Allen, R.G.; Davis; Thomas, S.J.

1986-07-01

Thresholds for retinal vitreal and contained hemorrhages were determined for 1064-nm laser light at 30-ns and 4-ns pulsewidths. Rhesus monkeys received graded exposures from a neodymium-YAG laser onto either the macular or extramacular region of the retina. Contained hemorrhages appeared as concentric-ring structures with white punctuate centers. The vitreal hemorrhage was characterized by the presence of choroidal blood in the vitreal chamber at the exposure site. The 30-ns contained-hemorrhage threshold (ED50) was 1.7 mJ on the macula and 2.1 mJ for an extramacular exposure. The 30-ns vitreal-hemorrhage macular threshold was 2.3 mJ, and the extramacular threshold was 6.6 Mj. The threshold for the 4-ns pulse widths to produce a hemorrhage (vitreal or contained) on the retina (macula or extramacular) was 340 uJ.

A curve of thresholds governs plague epizootics in Central Asia

DEFF Research Database (Denmark)

Reijniers, Jonas; Davis, Stephen; Begon, Mike

2012-01-01

, it is common to assume a threshold defined by the ratio of vector and host abundances. Here, we show in contrast, both from field data and model simulations, that for plague (Yersinia pestis) in Kazakhstan, the invasion threshold quantity is based on the product of its host (Rhombomys opimus) and vector...

ON THE NON-KOLMOGOROV NATURE OF FLARE-PRODUCTIVE SOLAR ACTIVE REGIONS

Energy Technology Data Exchange (ETDEWEB)

Mandage, Revati S. [Physics and Astronomy Department, Rice University, 6100 Main MS-61, Houston, TX 77005-1827 (United States); McAteer, R. T. James, E-mail: mcateer@nmsu.edu [Department of Astronomy, New Mexico State University, MSC 4500, Las Cruces, NM 88001 (United States)

2016-12-20

A magnetic power spectral analysis is performed on 53 solar active regions, observed from 2011 August to 2012 July. Magnetic field data obtained from the Helioseismic and Magnetic Imager, inverted as Active Region Patches, are used to study the evolution of the magnetic power index as each region rotates across the solar disk. Active regions are classified based on the numbers and sizes of solar flares they produce in order to study the relationship between flare productivity and the magnetic power index. The choice of window size and inertial range plays a key role in determining the correct magnetic power index. The overall distribution of magnetic power indices has a range of 1.0–2.5. Flare-quiet regions peak at a value of 1.6. However, flare-productive regions peak at a value of 2.2. Overall, the histogram of the distribution of power indices of flare-productive active regions is well separated from flare-quiet active regions. Only 12% of flare-quiet regions exhibit an index greater than 2, whereas 90% of flare-productive regions exhibit an index greater than 2. Flare-quiet regions exhibit a high temporal variance (i.e., the index fluctuates between high and low values), whereas flare-productive regions maintain an index greater than 2 for several days. This shows the importance of including the temporal evolution of active regions in flare prediction studies, and highlights the potential of a 2–3 day prediction window for space weather applications.

Threshold quantum cryptography

International Nuclear Information System (INIS)

Tokunaga, Yuuki; Okamoto, Tatsuaki; Imoto, Nobuyuki

2005-01-01

We present the concept of threshold collaborative unitary transformation or threshold quantum cryptography, which is a kind of quantum version of threshold cryptography. Threshold quantum cryptography states that classical shared secrets are distributed to several parties and a subset of them, whose number is greater than a threshold, collaborates to compute a quantum cryptographic function, while keeping each share secretly inside each party. The shared secrets are reusable if no cheating is detected. As a concrete example of this concept, we show a distributed protocol (with threshold) of conjugate coding

The investigation of strangeness photoproduction in the threshold region at ELPH-Tohoku

Energy Technology Data Exchange (ETDEWEB)

Kaneta, M., E-mail: kaneta@lambda.phys.tohoku.ac.jp [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Beckford, B. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Bydžovský, P. [Nuclear Institute, 25068 Řež (Czech Republic); Fujibayashi, T.; Fujii, T.; Fujii, Y.; Futatsukawa, K.; Gogami, T. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Han, Y.C. [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Hashimoto, O. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Hirose, K. [Research Center of Electron Photon Science, Tohoku University, Sendai 982-0826 (Japan); Hosomi, K.; Honda, R.; Iguchi, A. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Ishikawa, T. [Research Center of Electron Photon Science, Tohoku University, Sendai 982-0826 (Japan); Kanda, H.; Kaneko, Y.; Kasai, Y.; Kawasaki, T.; Kimura, C. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); and others

2013-09-20

The strangeness photoproduction processes near the threshold have been intensively studied by measuring K{sup +} in reactions such as γ+p→K{sup +}+Λ(Σ{sup 0}). There has been no reliable data on the neutron and as a consequence theoretical investigation suffered seriously from the lack of the data. We have an effort to measure the γ+d→K{sup 0}(Λ)+X reaction in the π{sup +}π{sup −} (pπ{sup −}) decay channel of K{sub S}{sup 0} (Λ) using a liquid D{sub 2} target and internally-tagged photon beams (E{sub γ}=0.80–1.08 GeV) at Research Center for Electron Photon Science (ELPH), Tohoku University. We have renewed the spectrometer (NKS2) and took data with a liquid D{sub 2} target in 2005–2007. More recently, we took data in 2010 after a detector upgrade in the vertex region to substantially increase the acceptance. The results of Λ single measurements on a deuterium target were obtained for differential cross-section as a function of momentum, as a function of angle, and integrated cross-section as a function of beam energy. The results are compared with recent theoretical studies: Isobar models (Kaon-MAID and Saclay-Lyon A) and a Regge-plus-Resonance model.

Defect Detection of Steel Surfaces with Global Adaptive Percentile Thresholding of Gradient Image

Science.gov (United States)

Neogi, Nirbhar; Mohanta, Dusmanta K.; Dutta, Pranab K.

2017-12-01

Steel strips are used extensively for white goods, auto bodies and other purposes where surface defects are not acceptable. On-line surface inspection systems can effectively detect and classify defects and help in taking corrective actions. For detection of defects use of gradients is very popular in highlighting and subsequently segmenting areas of interest in a surface inspection system. Most of the time, segmentation by a fixed value threshold leads to unsatisfactory results. As defects can be both very small and large in size, segmentation of a gradient image based on percentile thresholding can lead to inadequate or excessive segmentation of defective regions. A global adaptive percentile thresholding of gradient image has been formulated for blister defect and water-deposit (a pseudo defect) in steel strips. The developed method adaptively changes the percentile value used for thresholding depending on the number of pixels above some specific values of gray level of the gradient image. The method is able to segment defective regions selectively preserving the characteristics of defects irrespective of the size of the defects. The developed method performs better than Otsu method of thresholding and an adaptive thresholding method based on local properties.

Photoexcitation by gamma-ray scattering near threshold and giant dipole resonance

International Nuclear Information System (INIS)

Lakosi, L.; Safar, J.; Veres, A.; Sekine, T.; Kaji, H.; Yoshihara, K.

1993-01-01

Photoexcitation of 4.5 h half-life 115m In and 56 min half-life 103m Rh isomers by inelastic gamma-ray scattering near threshold and in the giant dipole resonance region has been reviewed. In disagreement with earlier experimental results available in the literature, but in good agreement with our experiments published recently, present calculations indicate that above the photoneutron emission threshold the isomer excitation drops abruptly and remains orders of magnitude smaller than at the threshold, even around resonance maximum. (author)

A large multi-cell threshold gas Cerenkov counter

International Nuclear Information System (INIS)

Declais, Y.; Aubert, J.J.; Bassompierre, G.; Payre, P.; Thenard, J.M.; Urban, L.

1980-08-01

A large multi-cell threshold gas Cerenkov counter consisting of 78 cells has been built for use in a high energy muon scattering experiment at CERN (European Muon Collaboration). It is used with neon, nitrogen or a mixture of those two gases, allowing the pion threshold to be varied between 6 and 20 GeV/c. The sensitive region of the counter has a length of 4.0 m and entrance and exit windows of 1.1 x 2.4 m 2 and 2.4 x 5.0 m 2 , respectively

Rainfall thresholds for the triggering of landslides in Slovenia

Science.gov (United States)

Peternel, Tina; Jemec Auflič, Mateja; Rosi, Ascanio; Segoni, Samuele; Komac, Marko; Casagli, Nicola

2017-04-01

Both at the worldwide level and in Slovenia, precipitation and related phenomena represent one of the most important triggering factors for the occurrence of slope mass movements. In the past decade, extreme rainfall events with a very high amount of precipitation occurs in a relatively short rainfall period have become increasingly important and more frequent, that causing numerous undesirable consequences. Intense rainstorms cause flash floods and mostly trigger shallow landslides and soil slips. On the other hand, the damage of long lasting rainstorms depends on the region's adaptation and its capacity to store or infiltrate excessive water from the rain. The amount and, consequently, the intensity of daily precipitation that can cause floods in the eastern part of Slovenia is a rather common event for the north-western part of the country. Likewise, the effect of rainfall is very dependent on the prior soil moisture, periods of full soil saturation and the creation of drifts in groundwater levels due to the slow melting of snow, growing period, etc. Landslides could be identified and to some extent also prevent with better knowledge of the relation between landslides and rainfall. In this paper the definition of rainfall thresholds for rainfall-induced landslides in Slovenia is presented. The thresholds have been calculated by collecting approximately 900 landslide data and the relative rainfall amounts, which have been collected from 41 rain gauges all over the country. The thresholds have been defined by the (1) use of an existing procedure, characterized by a high degree of objectiveness and (2) software that was developed for a test site with very different geological and climatic characteristics (Tuscany, central Italy). Firstly, a single national threshold has been defined, later the country was divided into four zones, on the basis of major the river basins and a single threshold has been calculated for each of them. Validation of the calculated

Model Threshold untuk Pembelajaran Memproduksi Pantun Kelas XI

Directory of Open Access Journals (Sweden)

Fitri Nura Murti

2017-03-01

Full Text Available Abstract: The learning pantun method in schools provided less opportunity to develop the students’ creativity in producing pantun. This situation was supported by the result of the observation conducted on eleventh graders at SMAN 2 Bondowoso. It showed that the students tend to plagiarize their pantun. The general objective of this research and development is to develop Threshold Pantun model for learning to produce pantun for elevent graders. The product was presented in guidance book for teachers entitled “Pembelajaran Memproduksi Pantun Menggunakan Model Threshold Pantun untuk Kelas XI”. This study adapted design method of Borg-Gall’s R&D procedure. The result of this study showed that Threshold Pantun model was appropriate to be implemented for learning to produce pantun. Key Words: Threshold Pantun model, produce pantun Abstrak: Pembelajaran pantun di sekolah selama ini kurang mengembangkan kreativitas siswa dalam memproduksi pantun. Hal tersebut dikuatkan oleh hasil observasi siswa kelas XI SMAN 2 Bondowoso yang menunjukkan adanya kecenderungan produk siswa bersifat plagiat. Tujuan penelitian dan pengembangan ini secara umum adalah mengembangkan model Threshold Pantun untuk pembelajaran memproduksi pantun kelas XI..Produk disajikan dalam bentuk buku panduan bagi guru dengan judul “Pembelajaran Memproduksi Pantun Menggunakan Model Threshold Pantun untuk Kelas XI”. Penelitian ini menggunakan rancangan penelitian yang diadaptasi dari prosedur penelitian dan pengembangan Borg dan Gall. Berdasarkan hasil validasi model Threshold Pantun untuk pembelajaran memproduksi pantun layak diimplementasikan. Kata kunci: model Threshold Pantun, memproduksi pantun

Fine structures in hearing thresholds and distortion product otoacoustic emissions

DEFF Research Database (Denmark)

Hammershøi, Dorte; Ordoñez, Rodrigo Pizarro; Torrente, Marina

2010-01-01

Otoacoustic emissions (OAEs) are weak sounds that can be recorded in the external ear. They are generated by the active amplification of the outer hair cells, and are by many believed to reflect the status of the most vulnerable part of the hearing better than ordinary behavioral thresholds. Dist...

Low-threshold support for families with dementia in Germany

Directory of Open Access Journals (Sweden)

Hochgraeber Iris

2012-06-01

Full Text Available Abstract Background Low-threshold support services are a part of the German health care system and help relieving family caregivers. There is limited information available on how to construct and implement low-threshold support services for people with dementia and their families in Germany. Some studies describe separately different perspectives of experiences and expectations, but there is no study combining all the different perspectives of those involved and taking the arrangements and organisation as well as their opinions on supporting and inhibiting factors into consideration. Findings This protocol describes the design of the study on low-threshold support services for families with a person with dementia in two German regions. The aim is to develop recommendations on how to build up these services and how to implement them in a region. A quantitative as well as a qualitative approach will be used. The quantitative part will be a survey on characteristics of service users and providers, as well as health care structures of the two project regions and an evaluation of important aspects derived from a literature search. Group discussions and semi-structured interviews will be carried out to get a deeper insight into the facilitators and barriers for both using and providing these services. All people involved will be included, such as the people with dementia, their relatives, volunteers, coordinators and institution representatives. Discussion Results of this study will provide important aspects for policymakers who are interested in an effective and low-threshold support for people with dementia. Furthermore the emerging recommendations can help staff and institutions to improve quality of care and can contribute to developing health and social care structures in Germany.

Business Cooperation and Regional Productive Development in ...

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

Business Cooperation and Regional Productive Development in Chile, El ... program dedicated to strengthening independent policy research institutions, ... Call for proposals: Innovations for the economic inclusion of marginalized youth.

Odour Detection Threshold Determination of Volatile Compounds in Topical Skin Formulations

DEFF Research Database (Denmark)

Thomsen, Birgitte Raagaard; Hyldig, Grethe; Taylor, Robert

2018-01-01

determination and also odour description by a trained sensory panel. In one case, the odour detection threshold value was 50 times higher (less detectable) in skin care products than in water, whereas for other volatile compounds the odour detection threshold value was only 1.5 times higher. The odour...

Cost-effectiveness thresholds: pros and cons.

Science.gov (United States)

Bertram, Melanie Y; Lauer, Jeremy A; De Joncheere, Kees; Edejer, Tessa; Hutubessy, Raymond; Kieny, Marie-Paule; Hill, Suzanne R

2016-12-01

Cost-effectiveness analysis is used to compare the costs and outcomes of alternative policy options. Each resulting cost-effectiveness ratio represents the magnitude of additional health gained per additional unit of resources spent. Cost-effectiveness thresholds allow cost-effectiveness ratios that represent good or very good value for money to be identified. In 2001, the World Health Organization's Commission on Macroeconomics in Health suggested cost-effectiveness thresholds based on multiples of a country's per-capita gross domestic product (GDP). In some contexts, in choosing which health interventions to fund and which not to fund, these thresholds have been used as decision rules. However, experience with the use of such GDP-based thresholds in decision-making processes at country level shows them to lack country specificity and this - in addition to uncertainty in the modelled cost-effectiveness ratios - can lead to the wrong decision on how to spend health-care resources. Cost-effectiveness information should be used alongside other considerations - e.g. budget impact and feasibility considerations - in a transparent decision-making process, rather than in isolation based on a single threshold value. Although cost-effectiveness ratios are undoubtedly informative in assessing value for money, countries should be encouraged to develop a context-specific process for decision-making that is supported by legislation, has stakeholder buy-in, for example the involvement of civil society organizations and patient groups, and is transparent, consistent and fair.

Cost–effectiveness thresholds: pros and cons

Science.gov (United States)

Lauer, Jeremy A; De Joncheere, Kees; Edejer, Tessa; Hutubessy, Raymond; Kieny, Marie-Paule; Hill, Suzanne R

2016-01-01

Abstract Cost–effectiveness analysis is used to compare the costs and outcomes of alternative policy options. Each resulting cost–effectiveness ratio represents the magnitude of additional health gained per additional unit of resources spent. Cost–effectiveness thresholds allow cost–effectiveness ratios that represent good or very good value for money to be identified. In 2001, the World Health Organization’s Commission on Macroeconomics in Health suggested cost–effectiveness thresholds based on multiples of a country’s per-capita gross domestic product (GDP). In some contexts, in choosing which health interventions to fund and which not to fund, these thresholds have been used as decision rules. However, experience with the use of such GDP-based thresholds in decision-making processes at country level shows them to lack country specificity and this – in addition to uncertainty in the modelled cost–effectiveness ratios – can lead to the wrong decision on how to spend health-care resources. Cost–effectiveness information should be used alongside other considerations – e.g. budget impact and feasibility considerations – in a transparent decision-making process, rather than in isolation based on a single threshold value. Although cost–effectiveness ratios are undoubtedly informative in assessing value for money, countries should be encouraged to develop a context-specific process for decision-making that is supported by legislation, has stakeholder buy-in, for example the involvement of civil society organizations and patient groups, and is transparent, consistent and fair. PMID:27994285

Risk management in crop production based on the regional index

Directory of Open Access Journals (Sweden)

Kokot Željko

2017-01-01

Full Text Available Regional index insurance is one of the newer instruments for reducing losses in crop production. The regional index indicates the average yield or average production value in a region, representing the basis for the premium calculation and insurance benefits. The main advantage of this insurance model is that it does not require the damage assessment, which is one of major problems in the relationship between the insured and insurer. In the case of corn, wheat and sunflower production as the most important crops in the region of Ada municipality, the authors describe the methodology of application of the analysed insurance system. Implementation of this contemporary form of insurance in Serbia would reduce the negative financial consequences in agricultural production. The abovementioned model of insurance can be seen as a significant alternative to conventional insurance, which can increase insured area and number of insured, and trust and confidence in insurance companies would also be restored.

Meson production in the 1 GeV/c2 mass region in the pd → 3He X reaction

International Nuclear Information System (INIS)

Wurzinger, R.; Plouin, F.; Spang, W.; Duval, M.A.; Frascaria, R.; Roudot, F.; Siebert, R.; Warde, E.; Bisplinghoff, J.; Ernst, J.; Hinterberger, F.; Jahn, R.; Joosten, R.; Kozela, A.; Lippert, C.; Von Oepen, T.

1995-01-01

Meson production near threshold has been studied at the SPES4 spectrometer at SATURNE using the pd → 3HeX missing mass reaction. Differential cross sections in the CM system for ω, η ' and φ are less than 1 nb/sr. The observed φ cross section is surprisingly large at threshold and clearly violates the naive OZI rule. No clear signals were obtained at the K anti K thresholds. The measurements can be extended to study broader mesons like f 0 and a 0 . (authors). 8 refs., 2 figs., 1 tab

Higgs-Stoponium Mixing Near the Stop-Antistop Threshold

CERN Document Server

Bodwin, Geoffrey T; Wagner, Carlos E M

2016-01-01

Supersymmetric extensions of the standard model contain additional heavy neutral Higgs bosons that are coupled to heavy scalar top quarks (stops). This system exhibits interesting field theoretic phenomena when the Higgs mass is close to the stop-antistop production threshold. Existing work in the literature has examined the digluon-to-diphoton cross section near threshold and has focused on enhancements in the cross section that might arise either from the perturbative contributions to the Higgs-to-digluon and Higgs-to-diphoton form factors or from mixing of the Higgs boson with stoponium states. Near threshold, enhancements in the relevant amplitudes that go as inverse powers of the stop-antistop relative velocity require resummations of perturbation theory and/or nonperturbative treatments. We present a complete formulation of threshold effects at leading order in the stop-antistop relative velocity in terms of nonrelativistic effective field theory. We give detailed numerical calculations for the case in ...

Factors affecting regional changes in hardwood lumber production

Science.gov (United States)

William G. Luppold; Gilbert P. Dempsey; Gilbert P. Dempsey

1994-01-01

Hardwood lumber production increased by nearly 1.8 billion board feet between 1986 and 1990 and decreased sharply in 1991. However, not all areas of the country experienced the same growth in hardwood lumber production during the 1980s. While lumber production in inland regions of the eastern United States and the west increased during the 1980s, lumber output in...

A Framework for Optimizing Phytosanitary Thresholds in Seed Systems.

Science.gov (United States)

Choudhury, Robin Alan; Garrett, Karen A; Klosterman, Steven J; Subbarao, Krishna V; McRoberts, Neil

2017-10-01

Seedborne pathogens and pests limit production in many agricultural systems. Quarantine programs help prevent the introduction of exotic pathogens into a country, but few regulations directly apply to reducing the reintroduction and spread of endemic pathogens. Use of phytosanitary thresholds helps limit the movement of pathogen inoculum through seed, but the costs associated with rejected seed lots can be prohibitive for voluntary implementation of phytosanitary thresholds. In this paper, we outline a framework to optimize thresholds for seedborne pathogens, balancing the cost of rejected seed lots and benefit of reduced inoculum levels. The method requires relatively small amounts of data, and the accuracy and robustness of the analysis improves over time as data accumulate from seed testing. We demonstrate the method first and illustrate it with a case study of seedborne oospores of Peronospora effusa, the causal agent of spinach downy mildew. A seed lot threshold of 0.23 oospores per seed could reduce the overall number of oospores entering the production system by 90% while removing 8% of seed lots destined for distribution. Alternative mitigation strategies may result in lower economic losses to seed producers, but have uncertain efficacy. We discuss future challenges and prospects for implementing this approach.

Heavy-Quark Production in the Target Fragmentation Region

CERN Document Server

Graudenz, Dirk

1997-01-01

Fixed-target experiments permit the study of hadron production in the target fragmentation region. It is expected that the tagging of specific particles in the target fragments can be employed to introduce a bias in the hard scattering process towards a specific flavour content. The case of hadrons containing a heavy quark is particularly attractive because of the clear experimental signatures and the applicability of perturbative QCD. The standard approach to one-particle inclusive processes based on fragmentation functions is valid in the current fragmentation region and for large transverse momenta $p_T$ in the target fragmentation region, but it fails for particle production at small $p_T$ in the target fragmentation region. A collinear singularity, which cannot be absorbed in the standard way into the phenomenological distribution functions, prohibits the application of this procedure. This situation is remedied by the introduction of a new set of distribution functions, the target fragmentation function...

Determinants of the accessibility of regional-product information

NARCIS (Netherlands)

Ittersum, van K.; Meulenberg, M.T.G.; Trijp, van J.C.M.

2003-01-01

In an era being characterized by globalization, the importance of product differentiation grows. Marketing products based on the region-of-origin (within-country area) is one of the strategies applied (i.e., Washington apples). Most place-of-origin research focuses on the effect of the

Productivity convergence and spatial dependence among Spanish regions

NARCIS (Netherlands)

Dall'erba, S.D.

2005-01-01

This paper estimates the evolution of labor productivity disparities among 48 Spanish regions over 1980-1996 according to the concepts of β- and σ-convergence. The results of β-convergence emphasize the importance of including the impact of neighboring locations' productivity and a disaggregate

Modeling of the Gross Regional Product on the Basis of Production Functions

Science.gov (United States)

Sadovin, Nikolay S.; Kokotkina, Tatiana N.; Barkalova, Tatiana G.; Tsaregorodsev, Evgeny I.

2016-01-01

The article is devoted to elaboration and construction of a static model of macroeconomics in which economics is considered as an unstructured holistic unit, the input of which receives the resources, and the output is the result of the functioning of economics in the form of gross domestic product or gross regional product. Resources are…

CARA Risk Assessment Thresholds

Science.gov (United States)

Hejduk, M. D.

2016-01-01

Warning remediation threshold (Red threshold): Pc level at which warnings are issued, and active remediation considered and usually executed. Analysis threshold (Green to Yellow threshold): Pc level at which analysis of event is indicated, including seeking additional information if warranted. Post-remediation threshold: Pc level to which remediation maneuvers are sized in order to achieve event remediation and obviate any need for immediate follow-up maneuvers. Maneuver screening threshold: Pc compliance level for routine maneuver screenings (more demanding than regular Red threshold due to additional maneuver uncertainty).

Fabrication of Pt nanowires with a diffraction-unlimited feature size by high-threshold lithography

International Nuclear Information System (INIS)

Li, Li; Zhang, Ziang; Yu, Miao; Song, Zhengxun; Weng, Zhankun; Wang, Zuobin; Li, Wenjun; Wang, Dapeng; Zhao, Le; Peng, Kuiqing

2015-01-01

Although the nanoscale world can already be observed at a diffraction-unlimited resolution using far-field optical microscopy, to make the step from microscopy to lithography still requires a suitable photoresist material system. In this letter, we consider the threshold to be a region with a width characterized by the extreme feature size obtained using a Gaussian beam spot. By narrowing such a region through improvement of the threshold sensitization to intensity in a high-threshold material system, the minimal feature size becomes smaller. By using platinum as the negative photoresist, we demonstrate that high-threshold lithography can be used to fabricate nanowire arrays with a scalable resolution along the axial direction of the linewidth from the micro- to the nanoscale using a nanosecond-pulsed laser source with a wavelength λ 0  = 1064 nm. The minimal feature size is only several nanometers (sub λ 0 /100). Compared with conventional polymer resist lithography, the advantages of high-threshold lithography are sharper pinpoints of laser intensity triggering the threshold response and also higher robustness allowing for large area exposure by a less-expensive nanosecond-pulsed laser

Regional differences in adipocyte lactate production from glucose

International Nuclear Information System (INIS)

Newby, F.D.; Sykes, M.N.; DiGirolamo, M.

1988-01-01

Having shown that lactate is an important product of glucose metabolism by rat epididymal adipocytes, the authors investigated possible regional differences in adipocyte lactate production and the role of the animals' nutritional state and stage of development. [U- 14 C]glucose metabolism, lactate production, and response to insulin were measured in fat cells isolated from four adipose regions from young lean and older fatter rats, killed either in the fed state or after fasting for 48 h. In the absence of insulin, mesenteric fat cells from either age group metabolized significantly more glucose per cell and converted more glucose to lactate than cells from other depots, regardless of nutritional state. Adipocytes from fasted lean rats showed a significant increase in the relative glucose conversion to lactate in all depots when compared with cells from fed lean rats. Fasting of older fatter rats, however, had limited effects on the relative adipocyte glucose conversion to lactate since lactate production was already high. Mesenteric fat cells had the lowest relative response to insulin, possibly due to the high basal rate of glucose metabolism. These findings indicate that differences exist among adipose regions in the rates of glucose metabolism, lactate production and response to insulin. The anatomical location of the mesenteric adipose depot, coupled with a high metabolic rate and blood perfusion, suggests that mesenteric adipocytes may provide a unique and more direct contribution of metabolic substrates for hepatic metabolism than adipocytes from other depots

Social-Ecological Thresholds in a Changing Boreal Landscape: Insights from Cree Knowledge of the Lesser Slave Lake Region of Alberta, Canada

Directory of Open Access Journals (Sweden)

Brenda L. Parlee

2012-06-01

Full Text Available Drawing on the traditional ecological knowledge (TEK of the Lesser Slave Lake Cree, this paper shares understanding of how resource development has affected water, fish, forests, and wildlife as well as the well-being of Cree communities in the Lesser Slave Lake region of Alberta, Canada. In addition to descriptive observations of change, the narratives point to social-ecological thresholds or tipping points in the relationship of Cree harvesters to local lands and resources. Specifically, the study speaks to the echoing effects of ecological loss and degradation on traditional livelihood practices over the last 100 years highlighting the complexity of cumulative effects as well as the challenges of balancing resource development in the region with alternative land uses including those valued by Alberta's Aboriginal peoples.

Ozone phytotoxicity evaluation and prediction of crops production in tropical regions

Science.gov (United States)

Mohammed, Nurul Izma; Ramli, Nor Azam; Yahya, Ahmad Shukri

2013-04-01

Increasing ozone concentration in the atmosphere can threaten food security due to its effects on crop production. Since the 1980s, ozone has been believed to be the most damaging air pollutant to crops. In Malaysia, there is no index to indicate the reduction of crops due to the exposure of ozone. Therefore, this study aimed to identify the accumulated exposure over a threshold of X ppb (AOTX) indexes in assessing crop reduction in Malaysia. In European countries, crop response to ozone exposure is mostly expressed as AOT40. This study was designed to evaluate and predict crop reduction in tropical regions and in particular, the Malaysian climate, by adopting the AOT40 index method and modifying it based on Malaysian air quality and crop data. Nine AOTX indexes (AOT0, AOT5, AOT10, AOT15, AOT20, AOT25, AOT30, AOT40, and AOT50) were analyzed, crop responses tested and reduction in crops predicted. The results showed that the AOT50 resulted in the highest reduction in crops and the highest R2 value between the AOT50 and the crops reduction from the linear regression analysis. Hence, this study suggests that the AOT50 index is the most suitable index to estimate the potential ozone impact on crops in tropical regions. The result showed that the critical level for AOT50 index if the estimated crop reduction is 5% was 1336 ppb h. Additionally, the results indicated that the AOT40 index in Malaysia gave a minimum percentage of 6% crop reduction; as contrasted with the European guideline of 5% (due to differences in the climate e.g., average amount of sunshine).

Effect of Electron Seeding on Experimentally Measured Multipactor Discharge Threshold

Science.gov (United States)

Noland, Jonathan; Graves, Timothy; Lemon, Colby; Looper, Mark; Farkas, Alex

2012-10-01

Multipactor is a vacuum phenomenon in which electrons, moving in resonance with an externally applied electric field, impact material surfaces. If the number of secondary electrons created per primary electron impact averages more than unity, the resonant interaction can lead to an electron avalanche. Multipactor is a generally undesirable phenomenon, as it can cause local heating, absorb power, or cause detuning of RF circuits. In order to increase the probability of multipactor initiation, test facilities often employ various seeding sources such as radioactive sources (Cesium 137, Strontium 90), electron guns, or photon sources. Even with these sources, the voltage for multipactor initiation is not certain as parameters such as material type, RF pulse length, and device wall thickness can all affect seed electron flux and energy in critical gap regions, and hence the measured voltage threshold. This study investigates the effects of seed electron source type (e.g., photons versus beta particles), material type, gap size, and RF pulse length variation on multipactor threshold. In addition to the experimental work, GEANT4 simulations will be used to estimate the production rate of low energy electrons (< 5 keV) by high energy electrons and photons. A comparison of the experimental fluxes to the typical energetic photon and particle fluxes experienced by spacecraft in various orbits will also be made. Initial results indicate that for a simple, parallel plate device made of aluminum, there is no threshold variation (with seed electrons versus with no seed electrons) under continuous-wave RF exposure.

Toward a definition of a threshold for harmless doses to the anal-sphincter region and the rectum

International Nuclear Information System (INIS)

Al-Abany, Massoud; Helgason, Asgeir R.; Agren Cronqvist, Anna-Karin; Lind, Bengt; Mavroidis, Panayiotis; Wersaell, Peter; Lind, Helena; Qvanta, Eva; Steineck, Gunnar

2005-01-01

Purpose: To investigate dysfunction caused by unwanted radiation to the anal-sphincter region and the rectum. Methods and materials: A questionnaire assessing bowel symptoms, sexual function, and urinary symptoms was sent to 72 patients with clinically localized prostatic adenocarcinoma treated by external beam radiation therapy at the Radiumhemmet, Karolinska Hospital, in Stockholm, Sweden, 2-4 years after treatment. The mean percentage dose-volume histograms for patients with and without the specific symptom were calculated. Results: Of the 65 patients providing information, 9 reported fecal leakage, 10 blood and mucus in stools, 10 defecation urgency, and 7 diarrhea or loose stools. None of the 19 and 13 patients who received, respectively, a dose of ≥35 Gy to ≤60% or ≥40 Gy to ≤40% of the anal-sphincter region volume reported fecal leakage (p < 0.05). In dose-volume histograms, a statistically significant correlation was found between radiation to the anal-sphincter region and the risk of fecal leakage in the interval 45-55 Gy. There was also a statistically significant correlation between radiation to the rectum and the risk of defecation urgency and diarrhea or loose stools in the interval 25-42 Gy. No relationship was found between anatomic rectal wall volume and the investigated late effects. Conclusions: Although the limited data in this study prevent the definition of a conclusive threshold regarding volume and dose to the anal-sphincter region and untoward morbidity, it seems that careful monitoring of unnecessary irradiation to this area should be done because it can potentially help reduce the risk of adverse effects, such as fecal leakage. Future studies should pay more attention to the anal-sphincter region and help to more rigorously define its radiotherapeutic tolerance

Rejection thresholds in solid chocolate-flavored compound coating.

Science.gov (United States)

Harwood, Meriel L; Ziegler, Gregory R; Hayes, John E

2012-10-01

Classical detection thresholds do not predict liking, as they focus on the presence or absence of a sensation. Recently however, Prescott and colleagues described a new method, the rejection threshold, where a series of forced choice preference tasks are used to generate a dose-response function to determine hedonically acceptable concentrations. That is, how much is too much? To date, this approach has been used exclusively in liquid foods. Here, we determined group rejection thresholds in solid chocolate-flavored compound coating for bitterness. The influences of self-identified preferences for milk or dark chocolate, as well as eating style (chewers compared to melters) on rejection thresholds were investigated. Stimuli included milk chocolate-flavored compound coating spiked with increasing amounts of sucrose octaacetate, a bitter and generally recognized as safe additive. Paired preference tests (blank compared to spike) were used to determine the proportion of the group that preferred the blank. Across pairs, spiked samples were presented in ascending concentration. We were able to quantify and compare differences between 2 self-identified market segments. The rejection threshold for the dark chocolate preferring group was significantly higher than the milk chocolate preferring group (P= 0.01). Conversely, eating style did not affect group rejection thresholds (P= 0.14), although this may reflect the amount of chocolate given to participants. Additionally, there was no association between chocolate preference and eating style (P= 0.36). Present work supports the contention that this method can be used to examine preferences within specific market segments and potentially individual differences as they relate to ingestive behavior. This work makes use of the rejection threshold method to study market segmentation, extending its use to solid foods. We believe this method has broad applicability to the sensory specialist and product developer by providing a

Evaluation of Maryland abutment scour equation through selected threshold velocity methods

Science.gov (United States)

Benedict, S.T.

2010-01-01

The U.S. Geological Survey, in cooperation with the Maryland State Highway Administration, used field measurements of scour to evaluate the sensitivity of the Maryland abutment scour equation to the critical (or threshold) velocity variable. Four selected methods for estimating threshold velocity were applied to the Maryland abutment scour equation, and the predicted scour to the field measurements were compared. Results indicated that performance of the Maryland abutment scour equation was sensitive to the threshold velocity with some threshold velocity methods producing better estimates of predicted scour than did others. In addition, results indicated that regional stream characteristics can affect the performance of the Maryland abutment scour equation with moderate-gradient streams performing differently from low-gradient streams. On the basis of the findings of the investigation, guidance for selecting threshold velocity methods for application to the Maryland abutment scour equation are provided, and limitations are noted.

Threshold and resilience management of coupled urbanization and water environmental system in the rapidly changing coastal region.

Science.gov (United States)

Li, Yangfan; Li, Yi; Wu, Wei

2016-01-01

The concept of thresholds shows important implications for environmental and resource management. Here we derived potential landscape thresholds which indicated abrupt changes in water quality or the dividing points between exceeding and failing to meet national surface water quality standards for a rapidly urbanizing city on the Eastern Coast in China. The analysis of landscape thresholds was based on regression models linking each of the seven water quality variables to each of the six landscape metrics for this coupled land-water system. We found substantial and accelerating urban sprawl at the suburban areas between 2000 and 2008, and detected significant nonlinear relations between water quality and landscape pattern. This research demonstrated that a simple modeling technique could provide insights on environmental thresholds to support more-informed decision making in land use, water environmental and resilience management. Copyright © 2015 Elsevier Ltd. All rights reserved.

Performance of iPad-based threshold perimetry in glaucoma and controls.

Science.gov (United States)

Schulz, Angela M; Graham, Elizabeth C; You, YuYi; Klistorner, Alexander; Graham, Stuart L

2017-10-04

Independent validation of iPad visual field testing software Melbourne Rapid Fields (MRF). To examine the functionality of MRF and compare its performance with Humphrey SITA 24-2 (HVF). Prospective, cross-sectional validation study. Sixty glaucomas (MD:-5.08±5.22); 17 pre-perimetric, 43 HVF field defects and 25 controls. The MRF was compared with HVF for scotoma detection, global indices, regional mean threshold values and sensitivity/specificity. Long-term test-retest variability was assessed after 6 months. Linear regression and Bland Altman analyses of global indices sensitivity/specificity using ROC curves, intraclass correlations. Using a cluster definition of three points at <1% or two at 0.5% to define a scotoma on HVF, MRF detected 39/54 abnormal hemifields with a similar threshold-based criteria. Global indices were highly correlated between MRF and HVF: MD r 2 = 0.80, PSD r 2 = 0.77, VFI r 2 = 0.85 (all P < 0.0001). For manifest glaucoma patients, correlations of regional mean thresholds ranged from r 2 = 0.45-0.78, despite differing array of tested points between devices. ROC analysis of global indices showed reasonable sensitivity/specificity with AUC values of MD:0.89, PSD:0.85 and VFI:0.88. MRF retest variability was low with ICC values at 0.95 (MD and VFI), 0.94 (PSD). However, individual test point variability for mid-range thresholds was higher. MRF perimetry, despite using a completely different test paradigm, shows good performance characteristics compared to HVF for detection of defects, correlation of global indices and regional mean threshold values. Reproducibility for individual points may limit application for monitoring change over time, and fixation monitoring needs improvement. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

Nonperturbative correction to the threshold production of t anti t-pairs

International Nuclear Information System (INIS)

Fadin, V.S.; Yakovlev, O.I.

1991-01-01

Calculations are performed of the nonperturbative correction to the cross-section for the tt-pair near the threshold in e + e - -annihilation, which is connected with the existence of a gluon condensate. These have been made using a constant chromoelectric field approximation. 15 refs

Narrow structure in Λd scattering near the Σ threshold (Σ3He states)

International Nuclear Information System (INIS)

Gibson, B.F.; Afnan, I.R.

1991-01-01

A separable-potential, Faddeev-type calculation of Λ-deuteron scattering near the threshold for Σ production is shown to produce structure (a resonance peak) in the cross section which lies below the Σ threshold for two different YN (ΛN-ΣN coupled-channel) potential models. In one case the ΣNN eigenvalue corresponds to a pole which lies below threshold (bound) and in the second case the poles lies above the threshold

Cascade processes after 3p-shell threshold photoionization of Kr

International Nuclear Information System (INIS)

Matsui, T.; Yoshii, H.; Higurashi, A.; Hayaishi, T.; Murakami, E.; Aoto, T.; Onuma, T.; Morioka, Y.; Yagishita, A.

2002-01-01

Yield spectra of the multiply charged ions Kr 2+ , Kr 3+ , Kr 4+ and Kr 5+ in coincidence with threshold electrons (E k ≤0.03 eV) have been measured near the 3p-shell ionization region of Kr. Profiles of post-collision interaction (PCI) effects induced by Auger cascades following 3p-shell threshold ionization are derived from these coincidence spectra. On the basis of the PCI profiles, the number of Auger cascade steps for each of the decay channels leading to the formation of the multiply charged ions in 3p 3/2 - and 3p 1/2 -shell threshold ionization of Kr was determined, and the branching ratios of the decay channels were estimated. (author)

Threshold-improved predictions for charm production in deep-inelastic scattering

International Nuclear Information System (INIS)

Lo Presti, N.A.; Kawamura, H.; Vogt, A.

2010-08-01

We have extended previous results on the threshold expansion of the gluon coefficient function for the charm contribution to the deep-inelastic structure function F 2 by deriving all thresholdenhanced contributions at the next-to-next-to-leading order. The size of these corrections is briefly illustrated, and a first step towards extending this improvement to more differential charmproduction cross sections is presented. (orig.)

Evidence accumulator or decision threshold - which cortical mechanism are we observing?

Directory of Open Access Journals (Sweden)

Patrick eSimen

2012-06-01

Full Text Available Most psychological models of perceptual decision making are of the accumulation-to-threshold variety. The neural basis of accumulation in parietal and prefrontal cortex is therefore a topic of great interest in neuroscience. In contrast, threshold mechanisms have received less attention, and their neural basis has usually been sought in subcortical structures. Here I analyze a model of a decision threshold that can be implemented in the same cortical areas as evidence accumulators, and whose behavior bears on two open questions in decision neuroscience: 1 When ramping activity is observed in a brain region during decision making, does it reflect evidence accumulation? 2 Are changes in speed-accuracy tradeoffs and response biases more likely to be achieved by changes in thresholds, or in accumulation rates and starting points? The analysis suggests that task-modulated ramping activity, by itself, is weak evidence that a brain area mediates evidence accumulation as opposed to threshold readout; and that signs of modulated accumulation are as likely to indicate threshold adaptation as adaptation of starting points and accumulation rates. These conclusions imply that how thresholds are modeled can dramatically impact accumulator-based interpretations of this data.

The effect of random dopant fluctuation on threshold voltage and drain current variation in junctionless nanotransistors

International Nuclear Information System (INIS)

Rezapour, Arash; Rezapour, Pegah

2015-01-01

We investigate the effect of dopant random fluctuation on threshold voltage and drain current variation in a two-gate nanoscale transistor. We used a quantum-corrected technology computer aided design simulation to run the simulation (10000 randomizations). With this simulation, we could study the effects of varying the dimensions (length and width), and thicknesses of oxide and dopant factors of a transistor on the threshold voltage and drain current in subthreshold region (off) and overthreshold (on). It was found that in the subthreshold region the variability of the drain current and threshold voltage is relatively fixed while in the overthreshold region the variability of the threshold voltage and drain current decreases remarkably, despite the slight reduction of gate voltage diffusion (compared with that of the subthreshold). These results have been interpreted by using previously reported models for threshold current variability, load displacement, and simple analytical calculations. Scaling analysis shows that the variability of the characteristics of this semiconductor increases as the effects of the short channel increases. Therefore, with a slight increase of length and a reduction of width, oxide thickness, and dopant factor, we could correct the effect of the short channel. (paper)

Automatic luminous reflections detector using global threshold with increased luminosity contrast in images

Science.gov (United States)

Silva, Ricardo Petri; Naozuka, Gustavo Taiji; Mastelini, Saulo Martiello; Felinto, Alan Salvany

2018-01-01

The incidence of luminous reflections (LR) in captured images can interfere with the color of the affected regions. These regions tend to oversaturate, becoming whitish and, consequently, losing the original color information of the scene. Decision processes that employ images acquired from digital cameras can be impaired by the LR incidence. Such applications include real-time video surgeries, facial, and ocular recognition. This work proposes an algorithm called contrast enhancement of potential LR regions, which is a preprocessing to increase the contrast of potential LR regions, in order to improve the performance of automatic LR detectors. In addition, three automatic detectors were compared with and without the employment of our preprocessing method. The first one is a technique already consolidated in the literature called the Chang-Tseng threshold. We propose two automatic detectors called adapted histogram peak and global threshold. We employed four performance metrics to evaluate the detectors, namely, accuracy, precision, exactitude, and root mean square error. The exactitude metric is developed by this work. Thus, a manually defined reference model was created. The global threshold detector combined with our preprocessing method presented the best results, with an average exactitude rate of 82.47%.

Theory of threshold phenomena

International Nuclear Information System (INIS)

Hategan, Cornel

2002-01-01

Theory of Threshold Phenomena in Quantum Scattering is developed in terms of Reduced Scattering Matrix. Relationships of different types of threshold anomalies both to nuclear reaction mechanisms and to nuclear reaction models are established. Magnitude of threshold effect is related to spectroscopic factor of zero-energy neutron state. The Theory of Threshold Phenomena, based on Reduced Scattering Matrix, does establish relationships between different types of threshold effects and nuclear reaction mechanisms: the cusp and non-resonant potential scattering, s-wave threshold anomaly and compound nucleus resonant scattering, p-wave anomaly and quasi-resonant scattering. A threshold anomaly related to resonant or quasi resonant scattering is enhanced provided the neutron threshold state has large spectroscopic amplitude. The Theory contains, as limit cases, Cusp Theories and also results of different nuclear reactions models as Charge Exchange, Weak Coupling, Bohr and Hauser-Feshbach models. (author)

Threshold resummation of the rapidity distribution for Higgs production at NNLO +NNLL

Science.gov (United States)

Banerjee, Pulak; Das, Goutam; Dhani, Prasanna K.; Ravindran, V.

2018-03-01

We present a formalism that resums threshold-enhanced logarithms to all orders in perturbative QCD for the rapidity distribution of any colorless particle produced in hadron colliders. We achieve this by exploiting the factorization properties and K +G equations satisfied by the soft and virtual parts of the cross section. We compute for the first time compact and most general expressions in two-dimensional Mellin space for the resummed coefficients. Using various state-of-the-art multiloop and multileg results, we demonstrate the numerical impact of our resummed results up to next-to-next-to-leading order for the rapidity distribution of the Higgs boson at the LHC. We find that inclusion of these threshold logs through resummation improves the reliability of perturbative predictions.

A threshold auto-adjustment algorithm of feature points extraction based on grid

Science.gov (United States)

Yao, Zili; Li, Jun; Dong, Gaojie

2018-02-01

When dealing with high-resolution digital images, detection of feature points is usually the very first important step. Valid feature points depend on the threshold. If the threshold is too low, plenty of feature points will be detected, and they may be aggregated in the rich texture regions, which consequently not only affects the speed of feature description, but also aggravates the burden of following processing; if the threshold is set high, the feature points in poor texture area will lack. To solve these problems, this paper proposes a threshold auto-adjustment method of feature extraction based on grid. By dividing the image into numbers of grid, threshold is set in every local grid for extracting the feature points. When the number of feature points does not meet the threshold requirement, the threshold will be adjusted automatically to change the final number of feature points The experimental results show that feature points produced by our method is more uniform and representative, which avoids the aggregation of feature points and greatly reduces the complexity of following work.

TRENDS OF DEVELOPMENT OF PRODUCTION AND REALIZATION OF PLANT PRODUCTION AGRICULTURAL ENTERPRISES OF MYKOLAIV REGION

Directory of Open Access Journals (Sweden)

Kushniruk Viktor

2018-03-01

Full Text Available Introduction. Agriculture is one of the largest and most important sectors of the Ukrainian economy. The food security and independence of the state, the state of the internal and external markets, and, consequently, the standard of living of the population are directly dependent on its functional state. Mykolaiv region has significant opportunities for the development of the agricultural sector. There are favorable natural and climatic conditions, fertile land, labor resources and long-standing cultivating traditions. The region is considered one of the regions of intensive agriculture in Ukraine and has significant land resources. Purpose. The article presents the analysis of the development of production and sale of crop production by the agrarian enterprises of the Mykolaiv region, as well as revealing ways to increase the volume of their production and sales. Results. The crop area of main agricultural crops in all categories of farms was analyzed, and structural changes for 2010-2016 were revealed. The priority branch of the agro-industrial complex, which has an important strategic significance, first of all, is determined by the level of production of which the food security of the state depends, its economy and welfare of the population. The dynamics of agricultural crop yields in agrarian enterprises as the determining factor of influence on the efficiency of activity in the field of plant growing is researched. The dynamics of gross collections of crop production in agricultural enterprises is analyzed and the contribution of the Mykolaiv region to the national production of grain is determined. The volumes and average prices of sales of agricultural products by agrarian enterprises are investigated and it is determined that the modern development of the agrarian sector of the economy requires special attention to the formation and activation of the activities of market infrastructure entities. The production of which crops are an

Threshold burnup for recrystallization and model for rim porosity in the high burnup UO2 fuel

International Nuclear Information System (INIS)

Lee, Byung Ho; Koo, Yang Hyun; Sohn, Dong Seong

1998-01-01

Applicability of the threshold burnup for rim formation was investigated as a function of temperature by Rest's model. The threshold burnup was the lowest in the intermediate temperature region, while on the other temperature regions the threshold burnup is higher. The rim porosity was predicted by the van der Waals equation based of the rim pore radius of 0.75μm and the overpressurization model on rim pores. The calculated centerline temperature is in good agreement with the measured temperature. However, more efforts seem to be necessary for the mechanistic model of the rim effect including rim growth with the fuel burnup

Regional characteristics of market production of sugar beet and sunflower in Serbia

Directory of Open Access Journals (Sweden)

Stevanović Simo

2016-01-01

Full Text Available The paper analyzes the trends in the development of industrial crop production in the case of sugar beet and sunflower in Serbia from 1976 to 2013. Grouping of regions (4 regions without Autonomous Province of Kosovo and Metohija and districts (25 districts in Serbia in 2013, according to the characteristics of land capacity, production of sugar beet and sunflower and level of development, was carried out by cluster analysis. Based on the median value of the important characteristics of available land capacity, production volume and economic development in municipalities, I-distance method were ranked districts in Serbia from 1 to 25. Similarities between the sugar beet and sunflower production regions in Serbia were determined by the method of complete-linkage clustering, and the results were presented in the dendrogram. According to data for 2013 it was found that 99.8% of sugar beet production and 93.9% of sunflower production in Serbia comes from the Vojvodina region. The average yields per hectare for analyzed crops in the areas of the Vojvodina region, on average, were by up to 10% higher compared to the yields in Serbia. According to the characteristics of land capacity and production, areas of the Vojvodina region belong to the highest rank 1-7, while according to the characteristics of the development level, these areas belong to rank 2-13.

Threshold photoelectron spectroscopy of acetaldehyde and acrolein

International Nuclear Information System (INIS)

Yencha, Andrew J.; Siggel-King, Michele R.F.; King, George C.; Malins, Andrew E.R.; Eypper, Marie

2013-01-01

Highlights: •High-resolution threshold photoelectron spectrum of acetaldehyde. •High-resolution threshold photoelectron spectrum of acrolein. •High-resolution total photoion yield spectrum of acetaldehyde. •High-resolution total photoion yield spectrum of acrolein. •Determination of vertical ionization potentials in acetaldehyde and acrolein. -- Abstract: High-resolution (6 meV and 12 meV) threshold photoelectron (TPE) spectra of acetaldehyde and acrolein (2-propenal) have been recorded over the valence binding energy region 10–20 eV, employing synchrotron radiation and a penetrating-field electron spectrometer. These TPE spectra are presented here for the first time. All of the band structures observed in the TPE spectra replicate those found in their conventional HeI photoelectron (PE) spectra. However, the relative band intensities are found to be dramatically different in the two types of spectra that are attributed to the different dominant operative formation mechanisms. In addition, some band shapes and their vertical ionization potentials are found to differ in the two types of spectra that are associated with the autoionization of Rydberg states in the two molecules

Elastic scattering and ω meson production near the threshold of π-p → ω + n

International Nuclear Information System (INIS)

Karami, H.; Carr, J.; Debenham, N.C.; Garbutt, D.A.; Jones, W.G.; Binnie, D.M.; Keyne, J.; Moissidis, P.; Sarma, H.N.; Siotis, I.

1979-01-01

Measurements are reported of the differential cross section for the reaction π - +p → ω + n from threshold to a final-state c.m. momentum P* of 200 MeV/c. The previously reported fall in total cross section sigma/P* below about 100 MeV/c is again seen. The differential cross section remains close to isotropic over the entire range. A parallel experiment on the variation in the elastic differential cross section across the threshold shows evidence of this threshold. The elastic data cover a range of incident moments from 1010 to 1180 MeV/c in steps of 5 MeV/c. (Auth.)

Thresholds of Toxicological Concern - Setting a threshold for testing below which there is little concern.

Science.gov (United States)

Hartung, Thomas

2017-01-01

Low dose, low risk; very low dose, no real risk. Setting a pragmatic threshold below which concerns become negligible is the purpose of thresholds of toxicological concern (TTC). The idea is that such threshold values do not need to be established for each and every chemical based on experimental data, but that by analyzing the distribution of lowest or no-effect doses of many chemicals, a TTC can be defined - typically using the 5th percentile of this distribution and lowering it by an uncertainty factor of, e.g., 100. In doing so, TTC aims to compare exposure information (dose) with a threshold below which any hazard manifestation is very unlikely to occur. The history and current developments of this concept are reviewed and the application of TTC for different regulated products and their hazards is discussed. TTC lends itself as a pragmatic filter to deprioritize testing needs whenever real-life exposures are much lower than levels where hazard manifestation would be expected, a situation that is called "negligible exposure" in the REACH legislation, though the TTC concept has not been fully incorporated in its implementation (yet). Other areas and regulations - especially in the food sector and for pharmaceutical impurities - are more proactive. Large, curated databases on toxic effects of chemicals provide us with the opportunity to set TTC for many hazards and substance classes and thus offer a precautionary second tier for risk assessments if hazard cannot be excluded. This allows focusing testing efforts better on relevant exposures to chemicals.

Ecosystem CO2 production during winter in a Swedish subarctic region: the relative importance of climate and vegetation type

DEFF Research Database (Denmark)

Grogan, Paul; Jonasson, Sven Evert

2006-01-01

General circulation models consistently predict that regional warming will be most rapid in the Arctic, that this warming will be predominantly in the winter season, and that it will often be accompanied by increasing snowfall. Paradoxically, despite the strong cold season emphasis in these predi...... will respond to climate change during winter because they indicate a threshold (~1 m) above which there would be little effect of increased snow accumulation on wintertime biogeochemical cycling....... in these predictions, we know relatively little about the plot and landscape-level controls on tundra biogeochemical cycling in wintertime as compared to summertime. We investigated the relative influence of vegetation type and climate on CO2 production rates and total wintertime CO2 release in the Scandinavian...... subarctic. Ecosystem respiration rates and a wide range of associated environmental and substrate pool size variables were measured in the two most common vegetation types of the region (birch understorey and heath tundra) at four paired sites along a 50 km transect through a strong snow depth gradient...

Contribution to the study of mesons and their interactions with nuclei, by threshold production in low nucleon number systems; Contribution a l`etude des mesons et de leur interaction avec les noyaux, par production au seuil dans les systemes a petit nombre de nucleons

Energy Technology Data Exchange (ETDEWEB)

Roudot, F

1995-01-01

The threshold excitation function of the pd {yields} {sup 3}HeX reaction and the total {eta}-meson production cross section near threshold in the dd {yields} {alpha}{eta} reaction have been measured using the SPES4 beam line of the Laboratoire National Saturne. In the pd {yields} {sup 3}HeX threshold function, clear signals are observed at {omega}, {eta}` and {phi}6 mesons threshold; some structures appear at central masses of the a{sub 0} and f{sub 0}-mesons, as just above the two kaons production threshold. These structures could be the signature of new hadronic exotic states. The two-pion and two-kaon physical background has been estimated in a one-pion exchange model allowing the calculation of the differential cross section for the {pi}{sup -}p {yields} nX elementary process. The results of this calculation of the physical background of the threshold excitation function. The the dd {yields} {alpha}{eta} study, the {eta}-meson was clearly observed in the spectrometer`s final focal plane spectra, in good agreement with a Monte Carlo simulation. A total cross section of the order of the nano-barn has been measured. The results are compared to some other {eta}-meson production processes with lighter nuclei than helium-4. Using different nuclei a comparative study of the {eta}-nucleus interaction has shown that the latter is more binding in the helium-4 case. Based on these data, the charge symmetry breaking in the dd {yields} {alpha}{pi}{sup 0} reaction is studied. Using a {pi}{sup 0}-{eta} mixing model, the extracted cross sections are compatible with the only measurement of this reaction cross section. (author). 59 refs.

What we can learn from γ γ → ππ, KKbar in the resonance region

International Nuclear Information System (INIS)

Morgan, D.; Pennington, M.R.

1987-07-01

The two photon couplings of hadronic states are believed to be key pointers to their parton constituents. With the aim of studying these, a method is presented of analysing data on γγ → ππ (and KKbar), which embodies the constraints of unitarity and analyticity while respecting the QED low energy theorem required by gauge invariance. This analysis is applied to presently available data on ππ production and it is found that within the existing uncertainties few definitive conclusions can yet be drawn in the resonance region. In the near threshold region, the authors confirm the overwhelming dominance of the QED Born amplitude modified by final state interactions, in contradiction with several recent data-sets on the π + π - channel. It is shown how the new Crystal Ball experiment on πsup(O)πsup(O) production not only confirms this conclusion on the near threshold cross-section, but angular analysis of their data with its better statistics using the method the authors present should shed light on the nature of the scalar mesons in the 1 GeV region. (author)

Organization of monitoring of agricultural products in NPP region

International Nuclear Information System (INIS)

Panteleev, L.I.; Spirin, E.V.; Sanzharova, N.I.

1990-01-01

Problem of organizing chemical and radiation monitoring of agricultural products in NPP region is considered. Attention is paid to monitoring during NPP siting and designing, to monitoring of radioactive contamination of agricultural products under normal NPP operation, emergency situations and decommissioning

Phi photoproduction near threshold with Okubo-Zweig-Iizuka evading phi NN interactions

CERN Document Server

William, R A

1998-01-01

Existing intermediate and high energy phi-photoproduction data is consistent with purely diffractive production (i.e., Pomeron exchange). However, near threshold (1.574 GeV K sup + K sup - decay angular distribution. We stress the importance of measurements with linearly polarized photons near the phi threshold to separate natural and unnatural parity exchange mechanisms. Approved and planned phi photoproduction and electroproduction experiments at Jefferson Lab will help establish the relative dynamical contributions near threshold and clarify outstanding theoretical issues related to apparent Okubo-Zweig-Iizuka violations.

Wind and Photovoltaic Large-Scale Regional Models for hourly production evaluation

DEFF Research Database (Denmark)

Marinelli, Mattia; Maule, Petr; Hahmann, Andrea N.

2015-01-01

This work presents two large-scale regional models used for the evaluation of normalized power output from wind turbines and photovoltaic power plants on a European regional scale. The models give an estimate of renewable production on a regional scale with 1 h resolution, starting from a mesosca...... of the transmission system, especially regarding the cross-border power flows. The tuning of these regional models is done using historical meteorological data acquired on a per-country basis and using publicly available data of installed capacity.......This work presents two large-scale regional models used for the evaluation of normalized power output from wind turbines and photovoltaic power plants on a European regional scale. The models give an estimate of renewable production on a regional scale with 1 h resolution, starting from a mesoscale...

Four-body calculation above four-body break-up threshold

International Nuclear Information System (INIS)

Uzu, E.; Kamada, H.; Koike, Y.

2005-01-01

The complex energy method [Prog. Theor. Phys. 109, 869L (2003)] is applied to the four body Faddeev-Yakubovsky equations in the four nucleon system. We obtain a well converged solution in all energy regions below and above the four nucleon break-up threshold

Improving the Regional Applicability of Satellite Precipitation Products by Ensemble Algorithm

Directory of Open Access Journals (Sweden)

Waseem Muhammad

2018-04-01

Full Text Available Satellite-based precipitation products (e.g., Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (IMERG and its predecessor, Tropical Rainfall Measuring Mission (TRMM are a critical source of precipitation estimation, particularly for a region with less, or no, hydrometric networking. However, the inconsistency in the performance of these products has been observed in different climatic and topographic diverse regions, timescales, and precipitation intensities and there is still room for improvement. Hence, using a projected ensemble algorithm, the regional precipitation estimate (RP is introduced here. The RP concept is mainly based on the regional performance weights derived from the Mean Square Error (MSE and the precipitation estimate from the TRMM product, that is, TRMM 3B42 (TR, real-time (late (IT and the research (post-real-time (IR products of IMERG. The overall results of the selected contingency table (e.g., Probability of detection (POD and statistical indices (e.g., Correlation Coefficient (CC signposted that the proposed RP product has shown an overall better potential to capture the gauge observations compared with the TR, IR, and IT in five different climatic regions of Pakistan from January 2015 to December 2016, at a diurnal time scale. The current study could be the first research providing preliminary feedback from Pakistan for global precipitation measurement researchers by highlighting the need for refinement in the IMERG.

Music effect on pain threshold evaluated with current perception threshold

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

AIM: Music relieves anxiety and psychotic tension. This effect of music is applied to surgical operation in the hospital and dental office. It is still unclear whether this music effect is only limited to the psychological aspect but not to the physical aspect or whether its music effect is influenced by the mood or emotion of audience. To elucidate these issues, we evaluated the music effect on pain threshold by current perception threshold (CPT) and profile of mood states (POMC) test. METHODS: Healthy 30 subjects (12 men, 18 women, 25-49 years old, mean age 34.9) were tested. (1)After POMC test, all subjects were evaluated pain threshold with CPT by Neurometer (Radionics, USA) under 6 conditions, silence, listening to the slow tempo classic music, nursery music, hard rock music, classic paino music and relaxation music with 30 seconds interval. (2)After Stroop color word test as the stresser, pain threshold was evaluated with CPT under 2 conditions, silence and listening to the slow tempo classic music. RESULTS: Under litening to the music, CPT sores increased, especially 2 000 Hz level related with compression, warm and pain sensation. Type of music, preference of music and stress also affected CPT score. CONCLUSION: The present study demonstrated that the concentration on the music raise the pain threshold and that stress and mood influence the music effect on pain threshold.

Power-Split Hybrid Electric Vehicle Energy Management Based on Improved Logic Threshold Approach

Directory of Open Access Journals (Sweden)

Zhumu Fu

2013-01-01

Full Text Available We design an improved logic threshold approach of energy management for a power-split HEV assisted by an integrated starter generator (ISG. By combining the efficiency map and the optimum torque curve of internal combustion engine (ICE with the state of charge (SOC of batteries, the improved logic threshold controller manages the ICE within its peak efficiency region at first. Then the electrical power demand is established based on the ICE energy output. On that premise, a variable logic threshold value K is defined to achieve the power distribution between the ISG and the electric motor/generator (EMG. Finally, simulation models for the power-split HEV with improved logic threshold controller are established in ADVISOR. Compared to the equally power-split HEV with the logic threshold controller, when using the improved logic threshold controller, the battery power consumption, the ICE efficiency, the fuel consumption, and the motor driving system efficiency are improved.

Type and characteristics of the regional products from West Yorkshire UK

Directory of Open Access Journals (Sweden)

Maria Grzybek

2010-01-01

Full Text Available The article presents the results of studies conducted among 200 British consumers who examined the characteristics of regional products, from West Yorkshire in the UK. The opinion showed that the highest scores obtained freshness and flavour of these goods. The appearance and packing of these products were evaluated at a good level. Consumers turned their attention to relatively high prices offered to regional products. They critically commented on the advertising campaigns that affect the growth of demand.

Threshold pressure for mechanoluminescence of macrocrystals, microcrystals and nanocrystals of doped zinc sulphide

Energy Technology Data Exchange (ETDEWEB)

Chandra, B.P. [School of Studies in Physics and Astrophysics, Pt. Ravishankar Shukla University, Raipur 492010, C.G. (India); Chandra, V.K. [Department of Electrical and Electronics Engineering, Chhatrapati Shivaji Institute of Technology, Shivaji Nagar, Kolihapuri, Durg 491001, C.G. (India); Jha, Piyush, E-mail: piyushjha22@rediffmail.com [Department of Applied Physics, Raipur Institute of Technology, Chhatauna, Mandir Hasuad, Raipur 492101, C.G. (India); Sonwane, V.D. [School of Studies in Physics and Astrophysics, Pt. Ravishankar Shukla University, Raipur 492010, C.G. (India)

2016-06-15

The threshold pressure for elastico-mechanoluminescence (EML) of ZnS:Mn macrocrystals is 20 MPa, and ZnS:Cu,Al macrocrystals do not show ML during elastic deformation. However, the threshold pressure for EML of ZnS:Mn and ZnS:Cu,Cl microcrystals and nanocrystals is nearly 1 MPa. Thus, it seems that high concentration of defects in microcrystalline and nanocrystalline ZnS:Mn and ZnS:Cu,Cl produces disorder and distortion in lattice and changes the local crystal-structure near impurities, and consequently, the enhanced piezoelectric constant of local region produces EML for low value of applied pressure. The threshold pressure for the ML of ZnS:Mn and ZnS:Cu,Al single macrocrystals is higher because such crystals possess comparatively less number of defects near the impurities where the phase-transition is not possible and their ML is caused for high value of stress because the bulk piezoelectric constant is less. Thus, size-dependent threshold pressure for ML supports the origin of EML from piezoelectricity in local region of the crystals. The finding of present investigation may be useful in tailoring phosphors emitting intense EML of different colours.

Threshold pressure for mechanoluminescence of macrocrystals, microcrystals and nanocrystals of doped zinc sulphide

International Nuclear Information System (INIS)

Chandra, B.P.; Chandra, V.K.; Jha, Piyush; Sonwane, V.D.

2016-01-01

The threshold pressure for elastico-mechanoluminescence (EML) of ZnS:Mn macrocrystals is 20 MPa, and ZnS:Cu,Al macrocrystals do not show ML during elastic deformation. However, the threshold pressure for EML of ZnS:Mn and ZnS:Cu,Cl microcrystals and nanocrystals is nearly 1 MPa. Thus, it seems that high concentration of defects in microcrystalline and nanocrystalline ZnS:Mn and ZnS:Cu,Cl produces disorder and distortion in lattice and changes the local crystal-structure near impurities, and consequently, the enhanced piezoelectric constant of local region produces EML for low value of applied pressure. The threshold pressure for the ML of ZnS:Mn and ZnS:Cu,Al single macrocrystals is higher because such crystals possess comparatively less number of defects near the impurities where the phase-transition is not possible and their ML is caused for high value of stress because the bulk piezoelectric constant is less. Thus, size-dependent threshold pressure for ML supports the origin of EML from piezoelectricity in local region of the crystals. The finding of present investigation may be useful in tailoring phosphors emitting intense EML of different colours.

Litterfall production under pine plantations in the southern Andes region of Ecuador

Directory of Open Access Journals (Sweden)

Pablo Quichimbo

2016-09-01

Full Text Available Litterfall research is an interesting aspect in environmental studies due to its significance in nutrient cycling specially in regions like the Andes where the interactions between biomass production and its decomposition is poorly understood. This study is focusing in the litterfall biomass production under pine plantations in southern Ecuador. The litterfall production was studied for five months at two-week intervals in three pine forest sites located in the southern Andes region of Ecuador. Monthly litterfall production ranged between 1067-1907 kg ha-1, in comparison with other coniferous stands around the world, this study revealed a higher litterfall production for tropical areas and particularly the highest production under pine plantations in the Andes region. This high litterfall production highlights the upmost importance of this forest component as a potential nutrient reservoir involved in the global nutrient cycling under landscapes dominated by this exotic forest specie in the tropical Andes.

Photoproduction of the φ(1020) near threshold in CLAS

International Nuclear Information System (INIS)

Tedeschi, D.J.

2002-01-01

The differential cross section for the photoproduction of the φ (1020) near threshold (E γ = 1.57GeV) is predicted to be sensitive to production mechanisms other than diffraction. However, the existing low energy data is of limited statistics and kinematical coverage. Complete measurements of φ meson production on the proton have been performed at The Thomas Jefferson National Accelerator Facility using a liquid hydrogen target and the CEBAF Large Acceptance Spectrometer (CLAS). The φ was identified by missing mass using a proton and positive kaon detected by CLAS in coincidence with an electron in the photon tagger. The energy of the tagged, bremsstrahlung photons ranged from φ-threshold to 2.4 GeV. A description of the data set and the differential cross section for (E γ = 2.0 GeV) will be presented and compared with present theoretical calculations. (author)

Portrait Of Portugal’s Nut Iii Regions In Productive Location Clusters

Directory of Open Access Journals (Sweden)

Francisco José Lopes de souse Diniz

2015-03-01

Full Text Available The purpose of this article is to piece together a picture of Portuguese regions at the end of the first decade of the twenty-first century. In particular, the authors tried to group NUT III regions according to the location of productive activities bearing in mind employment and other economic and social indicators, namely productivity and purchasing power, as well as competitiveness and environmental quality indicators. Using clusters, it was possible to obtain a map of Portugal containing 6 cluster typologies. Clearly, at one end of these typologies are the regions where tertiary activities are predominant and where there is more purchasing power, productivity and competitiveness, causing, however, more damages to the environment, whereas at the other end are the rural less competitive regions with a lower purchasing power but environmentally more attractive. In between, there are other situations which are also looked into.

Threshold friction velocity of soils within the Columbia Plateau

Science.gov (United States)

Wind erosion only occurs when the friction velocity exceeds the threshold friction velocity (TFV) of the surface. The TFV of loessial soils commonly found across the Columbia Plateau region of the U.S. Pacific Northwest is virtually unknown even though these soils are highly erodible and a source of...

A regional model for sustainable biogas production. Case study: North Savo, Finland

Energy Technology Data Exchange (ETDEWEB)

Huopana, T.; Niska, H.; Jaeskelaeinen, A.; Loonik, J.; Den Boer, E.; Song, H.; Thorin, E.

2012-11-15

This report is one of the outputs from the REMOWE (Regional Mobilizing of Sustainable Waste-to-Energy Production) project. REMOWE is one of the projects within the Baltic Sea Region Programme. The overall objective of the REMOWE project is, on regional levels, to contribute to a decreased negative effect on the environment by reduction of carbon dioxide emission by creating a balance between energy consumption and sustainable use of renewable energy sources. Reduction of carbon dioxide emissions and use of renewable energy sources are broad areas and this project will focus on energy resources from waste and actions to facilitate implementation of energy efficient technology in the Baltic Sea region within the waste-to-energy area. The focus is to utilize waste from cities, farming and industry for energy purposes in an efficient way. The problem addressed by the project concerns how to facilitate the implementation of sustainable systems for waste-to-energy in the Baltic Sea region and specifically, in a first step, in the project partner regions. The project partnership consists of the Maelardalen University, with the School of Sustainable Development of Society and Technology coordinating the project, and The County Administrative Board of Vaestmanland in Sweden, Savonia University of Applied Sciences, Centre for Economic Development, Transport and the Environment for North Savo, and University of Eastern Finland (UEF) in Finland, Marshal Office of Lower Silesia in Poland, Ostfalia University of Applied Sciences, Ostfalia University of Applied Sciences in Wolfenbuettel in Germany, Klaipeda University in Lithuania, and Estonian Regional and Local Development Agency (ERKAS) in Estonia. This report is based on the modelling work performed in the work package 5 ('Model of sustainable regional waste-to-energy production') of the REMOWE project. The key objective has been on developing a regional model based on available geographic information for

Measuring Poverty at the Regional Level in Spain: A Reflexive Approach

Directory of Open Access Journals (Sweden)

Nerea Zugasti

2017-01-01

Full Text Available This article assesses the utility of adjusting the poverty threshold for regional areas of Spain and of using thresholds anchored in time. It also offers a critical review of equivalence scales as a central element in estimating poverty. To do this, data from the Income and Living Conditions Surveys from 2007 to 2012 is used. The results show that poverty rates obtained with national thresholds are strongly influenced by intra-regional inequalities in income. They also show that regional thresholds capture differences in the well-being of the population, controlling for the effects of regional disparities in economic development. In addition, they demonstrate that anchored thresholds avoid inconsistencies in poverty rates tied to changes in income levels of the general population and not to changes in socially necessary resources.

Measurement of the generalized form factors near threshold via $\\gamma^* p \\to n\\pi^+$ at high $Q^2$

OpenAIRE

Park, Kijun; Gothe, Ralf; Adhikari, Krishna; Adikaram-Mudiyanselage, Dasuni; Anghinolfi, Marco; Baghdasaryan, Hovhannes; Ball, Jacques; Battaglieri, Marco; Baturin, Vitaly; Bedlinskiy, Ivan; Bennett, Robert; Biselli, Angela; Bookwalter, Craig; Boyarinov, Sergey; Branford, Derek

2012-01-01

We report the first extraction of the pion-nucleon multipoles near the production threshold for the $n\\pi^+$ channel at relatively high momentum transfer ($Q^2$ up to 4.2 $\\rm{GeV^2}$). The dominance of the s-wave transverse multipole ($E_{0+}$), expected in this region, allowed us to access the generalized form factor $G_1$ within the light-cone sum rule (LCSR) framework as well as the axial form factor $G_A$. The data analyzed in this work were collected by the nearly $4\\pi$ CEBAF Large Acc...

[Phosphorus application effects and input threshold of Chinese cabbage in the oasis irrigation region.

Science.gov (United States)

Lian, Cai Yun; Ma, Zhong Ming

2018-02-01

To resolve the problem of higher application and lower use efficiency of phosphorus fertilizer of Chinese cabbage (Brassica pekinensis), the yield, use efficiency of phosphate fertilizer and soil phosphate balance were examined by a located field trial in Zhangye Observation and Experiment Station of the Agro-ecological Environment in oasis irrigation region from 2011 to 2013. The results showed that the yield increased with the increase of phosphorus fertilization rate from 0 to 112.52 kg P·hm -2 , beyond which there would be no further enhancement. The yield was 5489.1 kg·hm -2 at 112.52 kg P·hm -2 treatment. This treatment increased the yield by 13.3%-23.8%, under which the phosphorus use efficiency was 14.2%. Soil Olsen-P and CaCl 2 -P were positively correlated. For 111.1 kg P·hm -2 treatment, the content of soil Olsen-P was 24.22 mg·kg -1 , with no phosphorus leaching and no pollution. At the rate of 60.17 kg P·hm -2 , there was a balance between phosphorus input and output and the phosphate demand of Chinese cabbage being met. In conclusion, the optimal phosphorus threshold was 60.17-112.52 kg·hm -2 for Chinese cabbage, the amount at which could reduce the risk of phosphorus pollution.

The pseudo-scalar form factor of the nucleon, the sigma-like term, and the L0+ amplitude for charged pion electro-production near threshold

International Nuclear Information System (INIS)

Cheoun, Myung Ki; Kim, K.S.

2007-01-01

The pseudo-scalar form factor, which represents the pseudo-scalar quark density distribution due to finite quark masses on the nucleon, is shown to manifest itself with the induced pseudo-scalar form factor in the L 0 + amplitude for the charged pion electro-production. Both form factors show their own peculiar momentum dependence. Under the approximation on which the Goldberger-Treiman relation holds, a sum of both form factors' contributions accounts for the t-channel contribution in the charged pion electro-production near threshold

Effect of transcranial direct current stimulation on vestibular-ocular and vestibulo-perceptual thresholds.

Science.gov (United States)

Kyriakareli, Artemis; Cousins, Sian; Pettorossi, Vito E; Bronstein, Adolfo M

2013-10-02

Transcranial direct current stimulation (tDCS) was used in 17 normal individuals to modulate vestibulo-ocular reflex (VOR) and self-motion perception rotational thresholds. The electrodes were applied over the temporoparietal junction bilaterally. Both vestibular nystagmic and perceptual thresholds were increased during as well as after tDCS stimulation. Body rotation was labeled as ipsilateral or contralateral to the anode side, but no difference was observed depending on the direction of rotation or hemisphere polarity. Threshold increase during tDCS was greater for VOR than for motion perception. 'Sham' stimulation had no effect on thresholds. We conclude that tDCS produces an immediate and sustained depression of cortical regions controlling VOR and movement perception. Temporoparietal areas appear to be involved in vestibular threshold modulation but the differential effects observed between VOR and perception suggest a partial dissociation between cortical processing of reflexive and perceptual responses.

Near threshold production of η-mesons in proton neutron collisions at ANKE

International Nuclear Information System (INIS)

Schröer, Daniel; Fritzsch, Christopher; Khoukaz, Alfons; Rump, Marcel

2016-01-01

The interaction between hadrons and η-mesons is an intensively studied topic. Due to its stength it might lead to the formation of η-mesic nuclei. In order to study the characteristics of this interaction a measurement of the reaction p + d → d + η + p_s_p has been performed at the ANKE spectrometer at the COSY accelerator of the Forschungszentrum Jülich. The two different beam momenta (p_1 = 2.09 GeV/c and p_2 = 2.25 GeV/c) in combination with the Fermi motion inside the target deuteron grant access to the determination of total and differential cross sections in an excess energy range from threshold up to Q = 90 MeV. While the course of the total cross section, especially near threshold, will allow to extract the scattering length a_d_η via an s-wave final state interaction ansatz, the differential cross sections permit to verify the legitimacy of the s-wave assumption.

Waste production and regional growth of marine activities an econometric model.

Science.gov (United States)

Bramati, Maria Caterina

2016-11-15

Coastal regions are characterized by intense human activity and climatic pressures, often intensified by competing interests in the use of marine waters. To assess the effect of public spending on the regional economy, an econometric model is here proposed. Not only are the regional investment and the climatic risks included in the model, but also variables related to the anthropogenic pressure, such as population, economic activities and waste production. Feedback effects of economic and demographic expansion on the pollution of coastal areas are also considered. It is found that dangerous waste increases with growing shipping and transportation activities and with growing population density in non-touristic coastal areas. On the other hand, the amount of non-dangerous wastes increases with marine mining, defense and offshore energy production activities. However, lower waste production occurs in areas where aquaculture and touristic industry are more exploited, and accompanied by increasing regional investment in waste disposal. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measurement of π-p→ηn from threshold to pπ-=747 MeV/c

International Nuclear Information System (INIS)

Prakhov, S.; Nefkens, B.M.K.; Clajus, M.; Marusic, A.; McDonald, S.; Phaisangittisakul, N.; Price, J.W.; Starostin, A.; Tippens, W.B.; Allgower, C.E.; Spinka, H.; Arndt, R.A.; Briscoe, W.J.; Shafi, A.; Strakovsky, I.I.; Workman, R.L.; Bekrenev, V.; Koulbardis, A.; Kozlenko, N.; Kruglov, S.

2005-01-01

The differential cross section for η production in reaction π - p→ηn has been measured over the full angular range at seven incident π - beam momenta from threshold to p π - =747 MeV/c using the Crystal Ball multiphoton spectrometer. The angular distributions are S wave dominated. At 10 MeV/c above threshold, a small D-wave contribution appears that interferes with the main S wave. The total η production cross section σ tot is obtained by integration of dσ/dΩ. Starting at threshold, σ tot rises rapidly, as expected for S-wave-dominated production. The features of the π - p→ηn cross section are strikingly similar to those of the SU(3) flavor-related process K - p→ηΛ. Comparison of the π - p→ηn reaction is made with η photoproduction

Are there regional differences in US hardwood product exports?

Science.gov (United States)

Matt Bumgardner; Scott Bowe; William Luppold

2016-01-01

Exporting is a critical component of the product mix for many domestic hardwood firms. Previous research has identified factors associated with hardwood lumber exporting behavior, but less is known about the advantages and disadvantages to exporting associated with the region within which a firm is located, or about exporting of secondary hardwood products. A procedure...

Part of celiac population still at risk despite current gluten thresholds

NARCIS (Netherlands)

Bruins Slot, I.D.; Bremer, M.G.E.G.; Hamer, R.J.; Fels, van der Ine

2015-01-01

In order to assist celiac disease (CD) patients in making safe food choices, gluten-free food products are labelled as such. The exact meaning of the gluten-free label differs throughout the world. This paper discusses the different thresholds that are currently used to label products gluten-free

Regional economic development in Europe : the role of total factor productivity

NARCIS (Netherlands)

Beugelsdijk, Sjoerd; Klasing, Mariko J.; Milionis, Petros

2018-01-01

Regional economic development in Europe: the role of total factor productivity. Regional Studies. This paper documents the fact that the large and persistent differences in economic development across subnational regions in European Union countries can largely be attributed to differences in total

Diagnosis of angiomyolipoma using computed tomography-region of interest ≤-10 HU or 4 adjacent pixels ≤-10 HU are recommended as the diagnostic thresholds

International Nuclear Information System (INIS)

Simpson, E.; Patel, U.

2006-01-01

AIM: To study and compare the diagnostic accuracy of region of interest (ROI) density measurement and pixel mapping [computed tomography (CT) density of individual pixels] for the diagnosis of renal angiomyolipoma (AML) using CT. MATERIALS AND METHODS: A study group of histologically proven AMLs was compared with a control group of histologically proven renal cell cancers, normal renal parenchyma, and simple renal cysts. The mean tissue density (ROI circle) and a pixel density map were recorded. The diagnostic accuracy of various thresholds of ROI and pixel mapping values were compared using receiver operating characteristic curves. RESULTS: Twenty-two AMLs, 16 renal cell carcinomas (RCCs), 30 simple cysts, and 30 sites of renal parenchyma were evaluated. The mean (±1 SD) density of the AMLs was significantly lower [-15.2(20.8) units] than the three control groups [+36.0(8.1) units, +5.4(3.4) units and +22.2(46.5) units for RCC, renal cyst and parenchyma respectively; p<0.001 (analysis of variance)]. The sensitivities and specificities of the ROI diagnostic thresholds of ≤0 units, ≤-10 units and ≤-20 units were 77 and 97%, 73 and 100% and 50 and 100%, respectively. Using pixel mapping [diagnostic thresholds of either a line of 4 pixels ≤-10 units or a square of 4 pixels ≤-10 units] the sensitivity improves to 86% with a specificity of 97%. CONCLUSION: Although a ROI threshold value of ≤-10 units has a very high specificity (100% in the present study) the sensitivity is modest at only 73%. Pixel mapping is more sensitive for recognizing small clusters of fat. In practice, both methods can be recommended for the analysis of suspected AMLs. ROI density measurement is convenient when analysing large areas of suspected fat and ≤-10 units should be used as the diagnostic threshold. When faced with small lucent areas or indeterminate values after ROI analysis, pixel mapping is recommended using a line of 4 pixels ≤-10 units or a square of 4 pixels ≤-10

Chemical safety of cassava products in regions adopting cassava production and processing - experience from Southern Africa

DEFF Research Database (Denmark)

Nyirenda, D.B.; Chiwona-Karltun, L.; Chitundu, M.

2011-01-01

and perceptions concerning cassava and chemical food safety. Chips, mixed biscuits and flour, procured from households and markets in three regions of Zambia (Luapula-North, Western and Southern) as well as products from the Northern, Central and Southern regions of Malawi, were analyzed for total cyanogenic...... of products commercially available on the market. Risk assessments disclose that effects harmful to the developing central nervous system (CNS) may be observed at a lower exposure than previously anticipated. We interviewed farmers in Zambia and Malawi about their cultivars, processing procedures......The cassava belt area in Southern Africa is experiencing an unforeseen surge in cassava production, processing and consumption. Little documentation exists on the effects of this surge on processing procedures, the prevailing levels of cyanogenic glucosides of products consumed and the levels...

Accelerator based production of fissile nuclides, threshold uranium price and perspectives; Akceleratorska proizvodnja fisibilnih nuklida, granicna cijena urana i perspektive

Energy Technology Data Exchange (ETDEWEB)

Djordjevic, D [INIS-Inzenjering, Sarajevo (Yugoslavia); Knapp, V [Elektrotehnicki fakultet, zagreb (Yugoslavia)

1988-07-01

Accelerator breeder system characteristics are considered in this work. One such system which produces fissile nuclides can supply several thermal reactors with fissile fuel, so this system becomes analogous to an uranium enrichment facility with difference that fissile nuclides are produced by conversion of U-238 rather than by separation from natural uranium. This concept, with other long-term perspective for fission technology on the basis of development only one simpler technology. The influence of basic system characteristics on threshold uranium price is examined. Conditions for economically acceptable production are established. (author)

Near-Threshold Computing and Minimum Supply Voltage of Single-Rail MCML Circuits

Directory of Open Access Journals (Sweden)

Ruiping Cao

2014-01-01

Full Text Available In high-speed applications, MOS current mode logic (MCML is a good alternative. Scaling down supply voltage of the MCML circuits can achieve low power-delay product (PDP. However, the current almost all MCML circuits are realized with dual-rail scheme, where the NMOS configuration in series limits the minimum supply voltage. In this paper, single-rail MCML (SRMCML circuits are described, which can avoid the devices configuration in series, since their logic evaluation block can be realized by only using MOS devices in parallel. The relationship between the minimum supply voltage of the SRMCML circuits and the model parameters of MOS transistors is derived, so that the minimum supply voltage can be estimated before circuit designs. An MCML dynamic flop-flop based on SRMCML is also proposed. The optimization algorithm for near-threshold sequential circuits is presented. A near-threshold SRMCML mode-10 counter based on the optimization algorithm is verified. Scaling down the supply voltage of the SRMCML circuits is also investigated. The power dissipation, delay, and power-delay products of these circuits are carried out. The results show that the near-threshold SRMCML circuits can obtain low delay and small power-delay product.

Effects of aging on vibration detection thresholds at various body regions

Directory of Open Access Journals (Sweden)

Walsh Natalie

2003-02-01

Full Text Available Abstract Background The ability to detect sinusoidal vibrations on the skin surface is dependent on the activation of two classes of receptors. The density of such receptors varies across the skin surface and is a factor in determining the sensory acuity of each skin area. However, the acuity of many sensory systems is known to deteriorate with advancing age. The aim of this study was to determine if vibrotactile sensibility of several skin surfaces deteriorated equally with advancing age. Methods Vibration detection thresholds for two frequencies of vibration (30 Hz and 200 Hz were determined using a method of limits protocol, in two groups of healthy adults, one group aged 17 to 27 years and the other aged 55 to 90 years. Sinusoidal vibrations were generated by a computer and delivered to the skin surface via the probe (diameter = 2 mm of a mechanical vibrator. Four skin sites (palmar surface of the tip of the middle finger, volar surface of the forearm, lateral aspect of the shoulder, cheek just caudal to the zygoma were tested. Results The fingertip was the most sensitive site for vibrotactile detection at both frequencies in a substantial majority of subjects. The older group of subjects showed significantly higher detection thresholds for both frequencies at all sites, except the fingertip, when compared to young subjects. Conclusion The study confirms the deterioration of vibrotactile acuity at several skin sites previously reported in the literature. However, there appears to be no significant reduction in vibrotactile detection at the fingertips in older subjects. This may reflect the high receptor density of this area, or the functional importance of vibrotactile sensibility of the fingertips or some combination of both of these factors.

Threshold enhancement of diphoton resonances

CERN Document Server

Bharucha, Aoife; Goudelis, Andreas

2016-10-10

The data collected by the LHC collaborations at an energy of 13 TeV indicates the presence of an excess in the diphoton spectrum that would correspond to a resonance of a 750 GeV mass. The apparently large production cross section is nevertheless very difficult to explain in minimal models. We consider the possibility that the resonance is a pseudoscalar boson $A$ with a two--photon decay mediated by a charged and uncolored fermion having a mass at the $\\frac12 M_A$ threshold and a very small decay width, $\\ll 1$ MeV; one can then generate a large enhancement of the $A\\gamma\\gamma$ amplitude which explains the excess without invoking a large multiplicity of particles propagating in the loop, large electric charges and/or very strong Yukawa couplings. The implications of such a threshold enhancement are discussed in two explicit scenarios: i) the Minimal Supersymmetric Standard Model in which the $A$ state is produced via the top quark mediated gluon fusion process and decays into photons predominantly through...

Recent results on prototype aerogel threshold counters for particle identification in the region: 0.5 6 4.3 GeV / c

International Nuclear Information System (INIS)

Arisaka, K.; Borsato, E.; DalCorso, F.; Iacovella, F.; Morandin, M.; Posocco, M.; Stroili, R.; Torassa, DE.; Voci, C.; Boutigny, D.; Bonis, I. de; Favier, J.; Karyotakis, Y.; Lafaye, R.; Ferroni, F.; Mazzoni, M.A.; Morganti, S.; Piredda, G.; Santacesaria, R.; Oyang, J.

1996-01-01

The recent development of new processes has lead to the fabrication of small density silica aerogel with high optical quality. The BaBar experiment, in order to achieve its physics program, requires a good pion kaon identification capability up to 4.3 GeV/c able to work inside a 1.5 Tesla magnetic field. An aerogel threshold counter using thee combination of 2 refractive indices (1.055 and 1.007) can be used to complete the angular coverage of the particle identification system in the forward region. Different detector geometries read out by two photo-detectors types (fine mesh phototubes and Hybrid Photo-Diodes) have been considered and tested in CERN beam test. (author)

Putting Temperature and Oxygen Thresholds of Marine Animals in Context of Environmental Change: A Regional Perspective for the Scotian Shelf and Gulf of St. Lawrence.

Directory of Open Access Journals (Sweden)

Catherine E Brennan

Full Text Available We conducted a literature review of reported temperature, salinity, pH, depth and oxygen preferences and thresholds of important marine species found in the Gulf of St. Lawrence and Scotian Shelf region. We classified 54 identified fishes and macroinvertebrates as important either because they support a commercial fishery, have threatened or at risk status, or meet one of the following criteria: bycatch, baitfish, invasive, vagrant, important for ecosystem energy transfer, or predators or prey of the above species. The compiled data allow an assessment of species-level impacts including physiological stress and mortality given predictions of future ocean physical and biogeochemical conditions. If an observed, multi-decadal oxygen trend on the central Scotian Shelf continues, a number of species will lose favorable oxygen conditions, experience oxygen-stress, or disappear due to insufficient oxygen in the coming half-century. Projected regional trends and natural variability are both large, and natural variability will act to alternately amplify and dampen anthropogenic changes. When estimates of variability are included with the trend, species encounter unfavourable oxygen conditions decades sooner. Finally, temperature and oxygen thresholds of adult Atlantic wolffish (Anarhichas lupus and adult Atlantic cod (Gadus morhua are assessed in the context of a potential future scenario derived from high-resolution ocean models for the central Scotian Shelf.

Threshold Signature Schemes Application

Directory of Open Access Journals (Sweden)

Anastasiya Victorovna Beresneva

2015-10-01

Full Text Available This work is devoted to an investigation of threshold signature schemes. The systematization of the threshold signature schemes was done, cryptographic constructions based on interpolation Lagrange polynomial, elliptic curves and bilinear pairings were examined. Different methods of generation and verification of threshold signatures were explored, the availability of practical usage of threshold schemes in mobile agents, Internet banking and e-currency was shown. The topics of further investigation were given and it could reduce a level of counterfeit electronic documents signed by a group of users.

Development and Restructuring of Regional Production/Distribution Networks in East Asia

OpenAIRE

Mitsuyo ANDO

2013-01-01

This paper attempts to investigate the features of development and restructuring patterns of production/distribution networks in East Asia, mainly in machinery sectors, using international trade data at the most disaggregated level, to discuss their resilient nature, and to provide policy implications for the regional production networks and the economic development in the region. Although the negative impacts of the Global Financial Crisis (GFC) in 2008 were initially transmitted through the...

Thresholds in radiobiology

International Nuclear Information System (INIS)

Katz, R.; Hofmann, W.

1982-01-01

Interpretations of biological radiation effects frequently use the word 'threshold'. The meaning of this word is explored together with its relationship to the fundamental character of radiation effects and to the question of perception. It is emphasised that although the existence of either a dose or an LET threshold can never be settled by experimental radiobiological investigations, it may be argued on fundamental statistical grounds that for all statistical processes, and especially where the number of observed events is small, the concept of a threshold is logically invalid. (U.K.)

Irreducible normalizer operators and thresholds for degenerate quantum codes with sublinear distances

Science.gov (United States)

Pryadko, Leonid P.; Dumer, Ilya; Kovalev, Alexey A.

2015-03-01

We construct a lower (existence) bound for the threshold of scalable quantum computation which is applicable to all stabilizer codes, including degenerate quantum codes with sublinear distance scaling. The threshold is based on enumerating irreducible operators in the normalizer of the code, i.e., those that cannot be decomposed into a product of two such operators with non-overlapping support. For quantum LDPC codes with logarithmic or power-law distances, we get threshold values which are parametrically better than the existing analytical bound based on percolation. The new bound also gives a finite threshold when applied to other families of degenerate quantum codes, e.g., the concatenated codes. This research was supported in part by the NSF Grant PHY-1416578 and by the ARO Grant W911NF-11-1-0027.

The impact of ethanol production on US and regional gasoline markets

International Nuclear Information System (INIS)

Du Xiaodong; Hayes, Dermot J.

2009-01-01

This study quantifies the impact of increasing ethanol production on wholesale/retail gasoline prices employing pooled regional time-series data from January 1995 to March 2008. We find that the growth in ethanol production kept wholesale gasoline prices $0.14/gallon lower than would otherwise have been the case. The negative impact of ethanol on retail gasoline prices is found to vary considerably across regions. The Midwest region has the biggest impact at $0.28/gallon, while the Rocky Mountain region had the smallest impact at $0.07/gallon. The results also indicate that the ethanol-induced reduction in gasoline prices comes at the expense of refiners' profits. We find a net welfare loss of $0.5 billion from the ethanol support policies in multiple markets.

Regional Changes in the Timber Resources of and Lumber Production in Pennsylvania

Science.gov (United States)

William G. Luppold; Matthew S. Bumgardner; Matthew S. Bumgardner

2005-01-01

In this study we examine regional differences in the hardwood timber resources of Pennsylvania and explain how the combined changes in this resource and in lumber prices have influenced regional lumber production. Isolation of these relationships is important because shifts in lumber production affect harvesting levels and harvesting activity influences long-term...

Discriminating the precipitation phase based on different temperature thresholds in the Songhua River Basin, China

Science.gov (United States)

Zhong, Keyuan; Zheng, Fenli; Xu, Ximeng; Qin, Chao

2018-06-01

Different precipitation phases (rain, snow or sleet) differ greatly in their hydrological and erosional processes. Therefore, accurate discrimination of the precipitation phase is highly important when researching hydrologic processes and climate change at high latitudes and mountainous regions. The objective of this study was to identify suitable temperature thresholds for discriminating the precipitation phase in the Songhua River Basin (SRB) based on 20-year daily precipitation collected from 60 meteorological stations located in and around the basin. Two methods, the air temperature method (AT method) and the wet bulb temperature method (WBT method), were used to discriminate the precipitation phase. Thirteen temperature thresholds were used to discriminate snowfall in the SRB. These thresholds included air temperatures from 0 to 5.5 °C at intervals of 0.5 °C and the wet bulb temperature (WBT). Three evaluation indices, the error percentage of discriminated snowfall days (Ep), the relative error of discriminated snowfall (Re) and the determination coefficient (R2), were applied to assess the discrimination accuracy. The results showed that 2.5 °C was the optimum threshold temperature for discriminating snowfall at the scale of the entire basin. Due to differences in the landscape conditions at the different stations, the optimum threshold varied by station. The optimal threshold ranged 1.5-4.0 °C, and 19 stations, 17 stations and 18 stations had optimal thresholds of 2.5 °C, 3.0 °C, and 3.5 °C respectively, occupying 90% of all stations. Compared with using a single suitable temperature threshold to discriminate snowfall throughout the basin, it was more accurate to use the optimum threshold at each station to estimate snowfall in the basin. In addition, snowfall was underestimated when the temperature threshold was the WBT and when the temperature threshold was below 2.5 °C, whereas snowfall was overestimated when the temperature threshold exceeded 4

Qualitative criteria and thresholds for low noise asphalt mixture design

Science.gov (United States)

Vaitkus, A.; Andriejauskas, T.; Gražulytė, J.; Šernas, O.; Vorobjovas, V.; Kleizienė, R.

2018-05-01

Low noise asphalt pavements are cost efficient and cost effective alternative for road traffic noise mitigation comparing with noise barriers, façade insulation and other known noise mitigation measures. However, design of low noise asphalt mixtures strongly depends on climate and traffic peculiarities of different regions. Severe climate regions face problems related with short durability of low noise asphalt mixtures in terms of considerable negative impact of harsh climate conditions (frost-thaw, large temperature fluctuations, hydrological behaviour, etc.) and traffic (traffic loads, traffic volumes, studded tyres, etc.). Thus there is a need to find balance between mechanical and acoustical durability as well as to ensure adequate pavement skid resistance for road safety purposes. Paper presents analysis of the qualitative criteria and design parameters thresholds of low noise asphalt mixtures. Different asphalt mixture composition materials (grading, aggregate, binder, additives, etc.) and relevant asphalt layer properties (air void content, texture, evenness, degree of compaction, etc.) were investigated and assessed according their suitability for durable and effective low noise pavements. Paper concluded with the overview of requirements, qualitative criteria and thresholds for low noise asphalt mixture design for severe climate regions.

Regional identity can add value to agricultural products

Directory of Open Access Journals (Sweden)

Bradley C. Christensen

2015-04-01

Full Text Available Regional identity creation is being recognized for its economic benefits and as a strategic resource for producer communities. A regional identity is not a brand; it is built through a complicated process of developing cohesion and sharing in the industry community and communicating outside the industry community to opinion-makers and consumers. The California fine wine industry has built successful regional identities and leveraged them to add value to their wines. As regional identities in the wine industry have strengthened, so has the industry, and a symbiotic relationship with other local value-added industries, such as tourism and hospitality, has emerged. Other agricultural producers can learn from the identity creation experiences in the wine industry. With the many challenges faced by California agriculture, identity formation may offer producers new ideas for adding value to their products and finding larger markets.

Near-threshold fatigue crack growth behavior of AISI 316 stainless steel

International Nuclear Information System (INIS)

Tobler, R.L.

1986-01-01

The near-threshold fatigue behavior of an AISI 316 alloy was characterized using a newly developed, fully automatic fatigue test apparatus. Significant differences in the near-threshold behavior at temperatures of 295 and 4 K are observed. At 295 K, where the operationally defined threshold at 10 -10 m/cycle is insensitive contains stress ratio and strongly affected by crack closure, the effective threshold stress intensity factor (ΔK/sub Th/)/sub eff/) is about 4.65 MPa m/sub 1/2/ at R = 0.3. At 4 K, the threshold is higher, crack closure is less pronounced, and there is a stress ratio dependency: (ΔK/sub Th/)/sub eff/ is 5.1 MPa m/sup 1/2/ at R = 0.3 and 6.1 MPa m/sup 1/2/ at R - 0.1. There is also a significant difference in the form of the da/dN-versus-ΔK curves on log-log coordinates: at 4 K the curve has the expected sigmoidal shape, but at 295 K the trend is linear over the region of da/dN from 10 -7 to 10 -10 m/cycle. Other results suggest that the near-threshold measurements of a 6.4-mm-thick specimen of this alloy are insensitive to cyclic test frequency below 40 Hz

Study of the photoproduction of the vector meson Φ(1020) and the hyperon Λ(1520) from the production threshold up to a photon energy of 2.65 GeV with SAPHIR

International Nuclear Information System (INIS)

Wiegers, B.

2001-05-01

The photoproduction of the vector meson φ(1020) and the hyperon Λ(1520) have been measured in the finale state pK + K - from their thresholds up to 2.65 GeV using the high duty-factor electron accelerator ELSA and the 4π-detectorsystem SAPHIR. The t-dependence of φ(1020)-production shows an exponential behavior as expected from diffractive production. s-channel helicity conservation can be seen in the decay angular distribution in the helicity frame. The decay angular distribution in the Gottfried-Jackson frame is not conformable with the exchange of a Pomeron in the t-channel. For the first time, differential cross sections of the Λ(1520) photoproduction from the threshold are measured. The production angular distribution and the decay angular distribution in the Gottfried-Jackson frame show a K * exchange in the t-channel. (orig.)

Shifts in the relationship between motor unit recruitment thresholds versus derecruitment thresholds during fatigue.

Science.gov (United States)

Stock, Matt S; Mota, Jacob A

2017-12-01

Muscle fatigue is associated with diminished twitch force amplitude. We examined changes in the motor unit recruitment versus derecruitment threshold relationship during fatigue. Nine men (mean age = 26 years) performed repeated isometric contractions at 50% maximal voluntary contraction (MVC) knee extensor force until exhaustion. Surface electromyographic signals were detected from the vastus lateralis, and were decomposed into their constituent motor unit action potential trains. Motor unit recruitment and derecruitment thresholds and firing rates at recruitment and derecruitment were evaluated at the beginning, middle, and end of the protocol. On average, 15 motor units were studied per contraction. For the initial contraction, three subjects showed greater recruitment thresholds than derecruitment thresholds for all motor units. Five subjects showed greater recruitment thresholds than derecruitment thresholds for only low-threshold motor units at the beginning, with a mean cross-over of 31.6% MVC. As the muscle fatigued, many motor units were derecruited at progressively higher forces. In turn, decreased slopes and increased y-intercepts were observed. These shifts were complemented by increased firing rates at derecruitment relative to recruitment. As the vastus lateralis fatigued, the central nervous system's compensatory adjustments resulted in a shift of the regression line of the recruitment versus derecruitment threshold relationship. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Decadal re-evaluation of contaminant exposure and productivity of ospreys (Pandion haliaetus) nesting in Chesapeake Bay Regions of Concern

International Nuclear Information System (INIS)

Lazarus, Rebecca S.; Rattner, Barnett A.; McGowan, Peter C.; Hale, Robert C.; Schultz, Sandra L.; Karouna-Renier, Natalie K.; Ottinger, Mary Ann

2015-01-01

The last large-scale ecotoxicological study of ospreys (Pandion haliaetus) in Chesapeake Bay was conducted in 2000–2001 and focused on U.S. EPA-designated Regions of Concern (ROCs; Baltimore Harbor/Patapsco, Anacostia/middle Potomac, and Elizabeth Rivers). In 2011–2012, ROCs were re-evaluated to determine spatial and temporal trends in productivity and contaminants. Concentrations of p,p′-DDE were low in eggs and below the threshold associated with eggshell thinning. Eggs from the Anacostia/middle Potomac Rivers had lower total PCB concentrations in 2011 than in 2000; however, concentrations remained unchanged in Baltimore Harbor. Polybrominated diphenyl ether flame retardants declined by 40%, and five alternative brominated flame retardants were detected at low levels. Osprey productivity was adequate to sustain local populations, and there was no relation between productivity and halogenated contaminants. Our findings document continued recovery of the osprey population, declining levels of many persistent halogenated compounds, and modest evidence of genetic damage in nestlings from industrialized regions. - Highlights: • This study documents the continued recovery of the Chesapeake Bay osprey population. • Osprey eggshells have nearly returned to pre-DDT-era thickness. • Organochlorine pesticides are low in eggs, but PCB levels seem unchanged in industrialized areas. • PBDE flame retardants have declined in eggs, but seem to peak near wastewater treatment plants. • There is some evidence of genetic damage in nestling blood samples in the most industrialized areas. - While the Chesapeake Bay osprey population has recovered, concentrations of some persistent contaminants in eggs remain unchanged, and there is some evidence of genetic damage in nestlings

Partial cross sections for Rb- photodetachment in the region of the Rb(5p2Psub(1/2,3/2)) thresholds and their analysis by multichannel quantum defect theory

International Nuclear Information System (INIS)

Frey, P.; Lawen, M.; Breyer, F.; Klar, H.; Hotop, H.

1982-01-01

A crossed ion-laser beam apparatus has been used to measure accurate relative total and partial cross sections for photodetachment from Rb - ions with high photon energy resolution (0.1-0.6 cm -1 ) in the region of the Rb(5p 2 Psub(1/2,3/2)) thresholds (photon energy range 16.350-16.820 cm -1 ). Satisfactory fits to these data by multichannel quantum defect theory (MQDT) have been obtained, resulting in a reliable set of seven MQDT parameters. The electron angular distribution parameter for the Rb(5s) channel was found to be β(5s)=2, independent of photon energy, MQDT predicts a sharp, window-type variation of β(5s) around the minimum of the 5s-cross section below the Rb(5p 2 Psub(1/2)) threshold (where an accurate experimental measurement of β(5s) was not possible) and a similar behaviour of β(6s) in the case of Cs - photodetachment below the Cs(6p 2 Psub(1/2)) threshold. (orig.)

Regional-Scale Declines in Productivity of Pink and Chum Salmon Stocks in Western North America

Science.gov (United States)

Malick, Michael J.; Cox, Sean P.

2016-01-01

Sockeye salmon (Oncorhynchus nerka) stocks throughout the southern part of their North American range have experienced declines in productivity over the past two decades. In this study, we tested the hypothesis that pink (O. gorbuscha) and chum (O. keta) salmon stocks have also experienced recent declines in productivity by investigating temporal and spatial trends in productivity of 99 wild North American pink and chum salmon stocks. We used a combination of population dynamics and time series models to quantify individual stock trends as well as common temporal trends in pink and chum salmon productivity across local, regional, and continental spatial scales. Our results indicated widespread declines in productivity of wild chum salmon stocks throughout Washington (WA) and British Columbia (BC) with 81% of stocks showing recent declines in productivity, although the exact form of the trends varied among regions. For pink salmon, the majority of stocks in WA and BC (65%) did not have strong temporal trends in productivity; however, all stocks that did have trends in productivity showed declining productivity since at least brood year 1996. We found weaker evidence of widespread declines in productivity for Alaska pink and chum salmon, with some regions and stocks showing declines in productivity (e.g., Kodiak chum salmon stocks) and others showing increases (e.g., Alaska Peninsula pink salmon stocks). We also found strong positive covariation between stock productivity series at the regional spatial scale for both pink and chum salmon, along with evidence that this regional-scale positive covariation has become stronger since the early 1990s in WA and BC. In general, our results suggest that common processes operating at the regional or multi-regional spatial scales drive productivity of pink and chum salmon stocks in western North America and that the effects of these process on productivity may change over time. PMID:26760510

Brand Products of Regional Cuisine in the Promotion of Tourism in Roztocze

Directory of Open Access Journals (Sweden)

Bekier-Jaworska Ewa

2015-03-01

Full Text Available Introduction. There has been a trend over the last few years of using specialties of regional cuisine as an independent tourist attraction. The creation of local brands is an important element in the promotion of a given region and it also influences the development of culinary tourism. The aim of the studies conducted was to identify regional dishes - a choice of dishes that could be described as 'brand dishes' and the use of those dishes as tourist attractions in Roztocze. Material and methods. Studies were conducted on a group of students studying tourism and recreation at State Higher School of Vocational Education (PWSZ in Zamość using a questionnaire. Results. The questionnaire provided an assessment of the levels of knowledge of regional cuisine among Polish and Ukrainian students, identified the most characteristic dishes and selected brand products, and helped to arrive at a suitable method of promotion. Conclusions. Nationality, family customs and selection of local restaurants highly influence knowledge of regional cuisine. Interviewees decided that the most outstanding products from Roztocze were Zwierzyniec beer, and Biłgoraj pie. Regional products should be used as a tourist attraction in Roztocze.

Comparison between intensity- duration thresholds and cumulative rainfall thresholds for the forecasting of landslide

Science.gov (United States)

Lagomarsino, Daniela; Rosi, Ascanio; Rossi, Guglielmo; Segoni, Samuele; Catani, Filippo

2014-05-01

This work makes a quantitative comparison between the results of landslide forecasting obtained using two different rainfall threshold models, one using intensity-duration thresholds and the other based on cumulative rainfall thresholds in an area of northern Tuscany of 116 km2. The first methodology identifies rainfall intensity-duration thresholds by means a software called MaCumBA (Massive CUMulative Brisk Analyzer) that analyzes rain-gauge records, extracts the intensities (I) and durations (D) of the rainstorms associated with the initiation of landslides, plots these values on a diagram, and identifies thresholds that define the lower bounds of the I-D values. A back analysis using data from past events can be used to identify the threshold conditions associated with the least amount of false alarms. The second method (SIGMA) is based on the hypothesis that anomalous or extreme values of rainfall are responsible for landslide triggering: the statistical distribution of the rainfall series is analyzed, and multiples of the standard deviation (σ) are used as thresholds to discriminate between ordinary and extraordinary rainfall events. The name of the model, SIGMA, reflects the central role of the standard deviations in the proposed methodology. The definition of intensity-duration rainfall thresholds requires the combined use of rainfall measurements and an inventory of dated landslides, whereas SIGMA model can be implemented using only rainfall data. These two methodologies were applied in an area of 116 km2 where a database of 1200 landslides was available for the period 2000-2012. The results obtained are compared and discussed. Although several examples of visual comparisons between different intensity-duration rainfall thresholds are reported in the international literature, a quantitative comparison between thresholds obtained in the same area using different techniques and approaches is a relatively undebated research topic.

Automated segmentation of tumors on bone scans using anatomy-specific thresholding

Science.gov (United States)

Chu, Gregory H.; Lo, Pechin; Kim, Hyun J.; Lu, Peiyun; Ramakrishna, Bharath; Gjertson, David; Poon, Cheryce; Auerbach, Martin; Goldin, Jonathan; Brown, Matthew S.

2012-03-01

Quantification of overall tumor area on bone scans may be a potential biomarker for treatment response assessment and has, to date, not been investigated. Segmentation of bone metastases on bone scans is a fundamental step for this response marker. In this paper, we propose a fully automated computerized method for the segmentation of bone metastases on bone scans, taking into account characteristics of different anatomic regions. A scan is first segmented into anatomic regions via an atlas-based segmentation procedure, which involves non-rigidly registering a labeled atlas scan to the patient scan. Next, an intensity normalization method is applied to account for varying levels of radiotracer dosing levels and scan timing. Lastly, lesions are segmented via anatomic regionspecific intensity thresholding. Thresholds are chosen by receiver operating characteristic (ROC) curve analysis against manual contouring by board certified nuclear medicine physicians. A leave-one-out cross validation of our method on a set of 39 bone scans with metastases marked by 2 board-certified nuclear medicine physicians yielded a median sensitivity of 95.5%, and specificity of 93.9%. Our method was compared with a global intensity thresholding method. The results show a comparable sensitivity and significantly improved overall specificity, with a p-value of 0.0069.

Electromagnetic Meson Production in the Nucleon Resonance Region

Energy Technology Data Exchange (ETDEWEB)

Volker Burkert; T.-S. H. Lee

2004-10-01

Recent experimental and theoretical advances in investigating electromagnetic meson production reactions in the nucleon resonance region are reviewed. The article gives a description of current experimental facilities with electron and photon beams and presents a unified derivation of most of the phenomenological approaches being used to extract the resonance parameters from the data. The analyses of {pi} and {eta} production data and the resulting transition form factors for the {Delta}(1232)P{sub 33}, N(1535)S{sub 11}, N(1440)P{sub 11}, and N(1520)D{sub 13} resonances are discussed in detail. The status of our understanding of the reactions with production of two pions, kaons, and vector mesons is also reviewed.

Ablation threshold and ablation mechanism transition of polyoxymethylene irradiated by CO2 laser.

Science.gov (United States)

Li, Gan; Cheng, Mousen; Li, Xiaokang

2016-09-01

Polyoxymethylene (POM) decomposes gradually as it is heated up by the irradiation of CO2 laser; the long-chain molecules of POM are broken into short chains, which leads to the lowering of the melting point and the critical temperature of the ablation products. When the product temperature is above the melting point, ablation comes up in the way of vaporization; when the product temperature is higher than the critical temperature, all liquid products are transformed into gas instantly and the ablation mechanism is changed. The laser fluence at which significant ablation is observed is defined as the ablation threshold, and the fluence corresponding to the ablation mechanism changing is denoted as the flyover threshold. In this paper, random pyrolysis is adopted to describe the pyrolytic decomposition of POM, and consequently, the components of the pyrolysis products under different pyrolysis rates are acquired. The Group Contribution method is used to count the thermodynamic properties of the pyrolysis products, and the melting point and the critical temperature of the product mixture are obtained by the Mixing Law. The Knudsen layer relationship is employed to evaluate the ablation mass removal when the product temperature is below the critical temperature. The gas dynamics conservation laws associated with the Jouguet condition are used to calculate the mass removal when the product temperature is higher than the critical temperature. Based on the model, a set of simulations for various laser intensities and lengths are carried out to generalize the relationships between the thresholds and the laser parameters. Besides the ablated mass areal density, which fits the experimental data quite well, the ablation temperature, pyrolysis rate, and product components are also discussed for a better understanding of the ablation mechanism of POM.

Detection thresholds of macaque otolith afferents.

Science.gov (United States)

Yu, Xiong-Jie; Dickman, J David; Angelaki, Dora E

2012-06-13

The vestibular system is our sixth sense and is important for spatial perception functions, yet the sensory detection and discrimination properties of vestibular neurons remain relatively unexplored. Here we have used signal detection theory to measure detection thresholds of otolith afferents using 1 Hz linear accelerations delivered along three cardinal axes. Direction detection thresholds were measured by comparing mean firing rates centered on response peak and trough (full-cycle thresholds) or by comparing peak/trough firing rates with spontaneous activity (half-cycle thresholds). Thresholds were similar for utricular and saccular afferents, as well as for lateral, fore/aft, and vertical motion directions. When computed along the preferred direction, full-cycle direction detection thresholds were 7.54 and 3.01 cm/s(2) for regular and irregular firing otolith afferents, respectively. Half-cycle thresholds were approximately double, with excitatory thresholds being half as large as inhibitory thresholds. The variability in threshold among afferents was directly related to neuronal gain and did not depend on spike count variance. The exact threshold values depended on both the time window used for spike count analysis and the filtering method used to calculate mean firing rate, although differences between regular and irregular afferent thresholds were independent of analysis parameters. The fact that minimum thresholds measured in macaque otolith afferents are of the same order of magnitude as human behavioral thresholds suggests that the vestibular periphery might determine the limit on our ability to detect or discriminate small differences in head movement, with little noise added during downstream processing.

ANALYSIS OF CRISIS LEVEL IN REGIONS OF UKRAINE

Directory of Open Access Journals (Sweden)

Irina Abramova

2017-12-01

Full Text Available The purpose of the paper is to identify the crisis level in regions of Ukraine in 2013–2015. The article also determines features, causes, and development of crisis situations in the regions of Ukraine and proposes measures to prevent the emergence and development of crisis situations or their disposal. Methodology. The basis for assessing the level of crisis in the socio-economic development of the region is to determine the level of deviation of actual indicators from the threshold values of socio-economic security. Such an assessment needs justification for the deviation of the actual indicators from the threshold values of socioeconomic security, which will correspond to a certain state of the depth of the crisis. The non-crisis zone characterizes the region as a powerful territorial centre of the country in the social and economic aspects. Actual indicators of the socio-economic development of this region are higher than the threshold values. Given the slowdown in the region’s development, the lack of innovative mechanisms for increasing economic potential, and the expansion of social programs for the population, this region may become a pre-crisis zone. A quantitative indicator of the zone of pre-crisis state, its threshold is numerical measurements, characterized by a 25-percent deviation from the threshold level of the non-crisis zone, which corresponds to the limits of indicators from 1.0 to 0.75. The growth of the same pace of socio-economic development, the implementation of effective measures of crisis management will lead to the transition of the region into a non-crisis zone. With a further fall in the level of socio-economic development, the region will fall into a zone of moderate crisis. In order to return to a precrisis state, regional authorities should develop a reactive anti-crisis strategy and effective rehabilitation programs. A quantitative indicator of this zone, its threshold is numerical measurements, which

Threshold guidance update

International Nuclear Information System (INIS)

Wickham, L.E.

1986-01-01

The Department of Energy (DOE) is developing the concept of threshold quantities for use in determining which waste materials must be handled as radioactive waste and which may be disposed of as nonradioactive waste at its sites. Waste above this concentration level would be managed as radioactive or mixed waste (if hazardous chemicals are present); waste below this level would be handled as sanitary waste. Last years' activities (1984) included the development of a threshold guidance dose, the development of threshold concentrations corresponding to the guidance dose, the development of supporting documentation, review by a technical peer review committee, and review by the DOE community. As a result of the comments, areas have been identified for more extensive analysis, including an alternative basis for selection of the guidance dose and the development of quality assurance guidelines. Development of quality assurance guidelines will provide a reasonable basis for determining that a given waste stream qualifies as a threshold waste stream and can then be the basis for a more extensive cost-benefit analysis. The threshold guidance and supporting documentation will be revised, based on the comments received. The revised documents will be provided to DOE by early November. DOE-HQ has indicated that the revised documents will be available for review by DOE field offices and their contractors

Relationship Between Unusual High-Temperature Fatigue Crack Growth Threshold Behavior in Superalloys and Sudden Failure Mode Transitions

Science.gov (United States)

Telesman, J.; Smith, T. M.; Gabb, T. P.; Ring, A. J.

2017-01-01

An investigation of high temperature cyclic fatigue crack growth (FCG) threshold behavior of two advanced nickel disk alloys was conducted. The focus of the study was the unusual crossover effect in the near-threshold region of these type of alloys where conditions which produce higher crack growth rates in the Paris regime, produce higher resistance to crack growth in the near threshold regime. It was shown that this crossover effect is associated with a sudden change in the fatigue failure mode from a predominant transgranular mode in the Paris regime to fully intergranular mode in the threshold fatigue crack growth region. This type of a sudden change in the fracture mechanisms has not been previously reported and is surprising considering that intergranular failure is typically associated with faster crack growth rates and not the slow FCG rates of the near-threshold regime. By characterizing this behavior as a function of test temperature, environment and cyclic frequency, it was determined that both the crossover effect and the onset of intergranular failure are caused by environmentally driven mechanisms which have not as yet been fully identified. A plausible explanation for the observed behavior is proposed.

Effects of threshold displacement energy on defect production by displacement cascades in α, β and γ-LiAlO2

International Nuclear Information System (INIS)

Tsuchihira, H.; Oda, T.; Tanaka, S.

2013-01-01

Threshold displacement energy evaluation and a series of displacement cascade simulations in α, β, and γ-LiAlO 2 were performed using molecular dynamics. Threshold displacement energy evaluations indicated that higher absolute ionic charge values and larger densities both increase threshold displacement energy. The displacement cascade simulations suggest that the influence of different crystal structures on the number of interstitial atoms generated in a displacement cascade is explainable almost entirely by the difference of the threshold displacement energy

Competitive behavior of photons contributing to junction voltage jump in narrow band-gap semiconductor multi-quantum-well laser diodes at lasing threshold

Energy Technology Data Exchange (ETDEWEB)

Feng, Liefeng, E-mail: fengliefeng@tju.edu.cn, E-mail: lihongru@nankai.edu.cn; Yang, Xiufang; Wang, Cunda; Yao, Dongsheng [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Faculty of Science, Tianjin University, Tianjin 300072 (China); Li, Yang [Business and Vocational College of Hainan, Haikou 570203 (China); Li, Ding; Hu, Xiaodong [Research Center for Wide Band Gap Semiconductors, State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Li, Hongru, E-mail: fengliefeng@tju.edu.cn, E-mail: lihongru@nankai.edu.cn [State Key Laboratory for Medicinal Chemistry and Biology, College of Pharmacy, Nankai University, Tianjin 300071 (China)

2015-04-15

The junction behavior of different narrow band-gap multi-quantum-well (MQW) laser diodes (LDs) confirmed that the jump in the junction voltage in the threshold region is a general characteristic of narrow band-gap LDs. The relative change in the 1310 nm LD is the most obvious. To analyze this sudden voltage change, the threshold region is divided into three stages by I{sub th}{sup l} and I{sub th}{sup u}, as shown in Fig. 2; I{sub th}{sup l} is the conventional threshold, and as long as the current is higher than this threshold, lasing exists and the IdV/dI-I plot drops suddenly; I{sub th}{sup u} is the steady lasing point, at which the separation of the quasi-Fermi levels of electron and holes across the active region (V{sub j}) is suddenly pinned. Based on the evolutionary model of dissipative structure theory, the rate equations of the photons in a single-mode LD were deduced in detail at I{sub th}{sup l} and I{sub th}{sup u}. The results proved that the observed behavior of stimulated emission suddenly substituting for spontaneous emission, in a manner similar to biological evolution, must lead to a sudden increase in the injection carriers in the threshold region, which then causes the sudden increase in the junction voltage in this region.

Competitive behavior of photons contributing to junction voltage jump in narrow band-gap semiconductor multi-quantum-well laser diodes at lasing threshold

International Nuclear Information System (INIS)

Feng, Liefeng; Yang, Xiufang; Wang, Cunda; Yao, Dongsheng; Li, Yang; Li, Ding; Hu, Xiaodong; Li, Hongru

2015-01-01

The junction behavior of different narrow band-gap multi-quantum-well (MQW) laser diodes (LDs) confirmed that the jump in the junction voltage in the threshold region is a general characteristic of narrow band-gap LDs. The relative change in the 1310 nm LD is the most obvious. To analyze this sudden voltage change, the threshold region is divided into three stages by I th l and I th u , as shown in Fig. 2; I th l is the conventional threshold, and as long as the current is higher than this threshold, lasing exists and the IdV/dI-I plot drops suddenly; I th u is the steady lasing point, at which the separation of the quasi-Fermi levels of electron and holes across the active region (V j ) is suddenly pinned. Based on the evolutionary model of dissipative structure theory, the rate equations of the photons in a single-mode LD were deduced in detail at I th l and I th u . The results proved that the observed behavior of stimulated emission suddenly substituting for spontaneous emission, in a manner similar to biological evolution, must lead to a sudden increase in the injection carriers in the threshold region, which then causes the sudden increase in the junction voltage in this region

Do region and gender influence hardwood product selection?

Science.gov (United States)

Delton Alderman

2013-01-01

Consumer preference is a fundamental focus of marketing research as it is used in developing marketing strategy and the positioning of products against competitors. This study evaluated consumer hardwood preferences of consumers from three United States geographical regions, which included six different metropolitan areas. Seven hardwood species and three laminate...

Ecological thresholds: The key to successful enviromental management or an important concept with no practical application?

Science.gov (United States)

Groffman, P.M.; Baron, Jill S.; Blett, T.; Gold, A.J.; Goodman, I.; Gunderson, L.H.; Levinson, B.M.; Palmer, Margaret A.; Paerl, H.W.; Peterson, G.D.; Poff, N.L.; Rejeski, D.W.; Reynolds, J.F.; Turner, M.G.; Weathers, K.C.; Wiens, J.

2006-01-01

An ecological threshold is the point at which there is an abrupt change in an ecosystem quality, property or phenomenon, or where small changes in an environmental driver produce large responses in the ecosystem. Analysis of thresholds is complicated by nonlinear dynamics and by multiple factor controls that operate at diverse spatial and temporal scales. These complexities have challenged the use and utility of threshold concepts in environmental management despite great concern about preventing dramatic state changes in valued ecosystems, the need for determining critical pollutant loads and the ubiquity of other threshold-based environmental problems. In this paper we define the scope of the thresholds concept in ecological science and discuss methods for identifying and investigating thresholds using a variety of examples from terrestrial and aquatic environments, at ecosystem, landscape and regional scales. We end with a discussion of key research needs in this area.

Waste production and regional growth of marine activities an econometric model

International Nuclear Information System (INIS)

Bramati, Maria Caterina

2016-01-01

Coastal regions are characterized by intense human activity and climatic pressures, often intensified by competing interests in the use of marine waters. To assess the effect of public spending on the regional economy, an econometric model is here proposed. Not only are the regional investment and the climatic risks included in the model, but also variables related to the anthropogenic pressure, such as population, economic activities and waste production. Feedback effects of economic and demographic expansion on the pollution of coastal areas are also considered. It is found that dangerous waste increases with growing shipping and transportation activities and with growing population density in non-touristic coastal areas. On the other hand, the amount of non-dangerous wastes increases with marine mining, defense and offshore energy production activities. However, lower waste production occurs in areas where aquaculture and touristic industry are more exploited, and accompanied by increasing regional investment in waste disposal. - Highlights: • We use an econometric model as a tool for assessing the effects of regional policies on the development of economic activities related to the use of the sea and on the impact on the marine environment. • Through scenario simulation we provide strategic guidelines for policy makers and economic planners • The model features feedback effects of economic and demographic expansion on the pollution of coastal areas.

BENCHMARKS FOR MILK PRODUCTION SYSTEMS IN THE PERNAMBUCO AGRESTE REGION, NORTHEASTERN BRAZIL

Directory of Open Access Journals (Sweden)

MARLA CONCEIÇÃO OLIVEIRA

2016-01-01

Full Text Available The objective of this work was to identify and assess the technological, zootechnical and socioeconomic profiles and identify and quantify benchmarks for dairy cattle production systems, in a non-experimental approach, aiming to contribute to the sustainability and competitiveness of dairy farming in the Pernambuco Agreste region, northeastern Brazil. Thirty-six milk production systems of family and corporate farming were evaluated during twelve months, in order to identify and quantify the benchmarks. The systems were characterized regarding their size and technological, zootechnical and economic profiles. The correlation coefficients of the return rate on invested capital were assessed and regression equations were developed for each indicator, according to four scenarios of annual return rates (4, 6, 8 and 10%. The indicators evaluated were milk production per dairy cows, milk production per area, average price of milk, effective operational cost, total operating cost, total cost per price of milk and profitability. The dairy farming in the Pernambuco Agreste region pays the production costs, but tends to a not adequate remuneration of family labor and a need of external capital input for replacement of the assets. The productivity of production factors area and animals showed higher correlation with cost-effectiveness, denoting the need for increase the production through increases in land area and milk productivity per dairy cow. The identification and quantification of benchmarks may help to identify the weak points of dairy farming in the Agreste region, making it sustainable and competitive.

MAG4 versus alternative techniques for forecasting active region flare productivity

Science.gov (United States)

Falconer, David A; Moore, Ronald L; Barghouty, Abdulnasser F; Khazanov, Igor

2014-01-01

MAG4 is a technique of forecasting an active region's rate of production of major flares in the coming few days from a free magnetic energy proxy. We present a statistical method of measuring the difference in performance between MAG4 and comparable alternative techniques that forecast an active region's major-flare productivity from alternative observed aspects of the active region. We demonstrate the method by measuring the difference in performance between the “Present MAG4” technique and each of three alternative techniques, called “McIntosh Active-Region Class,” “Total Magnetic Flux,” and “Next MAG4.” We do this by using (1) the MAG4 database of magnetograms and major flare histories of sunspot active regions, (2) the NOAA table of the major-flare productivity of each of 60 McIntosh active-region classes of sunspot active regions, and (3) five technique performance metrics (Heidke Skill Score, True Skill Score, Percent Correct, Probability of Detection, and False Alarm Rate) evaluated from 2000 random two-by-two contingency tables obtained from the databases. We find that (1) Present MAG4 far outperforms both McIntosh Active-Region Class and Total Magnetic Flux, (2) Next MAG4 significantly outperforms Present MAG4, (3) the performance of Next MAG4 is insensitive to the forward and backward temporal windows used, in the range of one to a few days, and (4) forecasting from the free-energy proxy in combination with either any broad category of McIntosh active-region classes or any Mount Wilson active-region class gives no significant performance improvement over forecasting from the free-energy proxy alone (Present MAG4). Key Points Quantitative comparison of performance of pairs of forecasting techniques Next MAG4 forecasts major flares more accurately than Present MAG4 Present MAG4 forecast outperforms McIntosh AR Class and total magnetic flux PMID:26213517

Productivity Effects of United States Multinational Enterprises : The Roles of Market Orientation and Regional Integration

NARCIS (Netherlands)

Smeets, Roger; Wei, Yingqi

2010-01-01

Smeets R. and Wei Y. Productivity effects of United States multinational enterprises: the roles of market orientation and regional integration, Regional Studies. This paper considers the role of market orientation and regional integration in foreign direct investment (FDI) productivity effects.

Multiple photoionization following 3d5/2-shell threshold ionization of

International Nuclear Information System (INIS)

Matsui, T; Yoshii, H; Tsukamoto, K; Kawakita, S; Murakami, E; Adachi, J; Yagishita, A; Morioka, Y; Hayaishi, T

2004-01-01

Multiple photoionization of Xe near the 3d 5/2 -shell threshold photoionization region is studied by threshold electron-ion coincidence spectroscopy. The coincidence spectra of Xe 3+ to Xe 7+ ions exhibit characteristic profiles associated with multi-step post-collision interactions in Auger cascades following 3d 5/2 -shell threshold photoionization. The Auger cascade decay channels leading to the formation of multiply charged ions are deduced from the energies of the profile peaks, which increase gradually with increasing charge state. The formation of Xe 3+ to Xe 5+ ions is found to arise from cascades of normal Auger decays, whereas the formation of Xe 6+ and Xe 7+ ions involves double Auger decays. The branching ratio of double to normal Auger decays is estimated to be 0.25 (±0.1) for the decays following the creation of 3d 5/2 -hole states in Xe

The Use of Lean Production Techniques as the Basis of Innovative Development of Region

Directory of Open Access Journals (Sweden)

Sergey G. Tyaglov

2017-06-01

Full Text Available In article methods, the principles and the main tools of technology of "economical production" are investigated. The possibility of application of "the concept the economical region" at the level of regional economies is analyzed. In the conditions of the policy of import substitution realized now in Russia, economical technologies, in our opinion, need to be considered as a basis of further innovative development of regions. Recently the philosophy of "economical production" which arose in Japan actively takes root the management of the Russian enterprises which treat, in particular such large organizations as: LLC Gazpromneft-Khantos, PJSC Rosneft, PJSC Sberbank, PJSC Gorky Automobile Plant, RUSAL United company, PJSC Kamaz, etc. The philosophy of "economical production" is implemented by means of certain tools and the principles. Treat the basic principles of economical technologies: probe of the existing losses, drop of negative consequences from the found losses by special methods and tools, and also monitoring of efficiency of functioning of system in general. The traditional tools used in the course of "economical production" are: mapping of a stream of creation of value, the 5S system, kaizen, visual management, the standardized operational instructions, kanban, bystry readjustment, general care of the equipment, "the extending production", etc. Use of the principles and instruments of "economical production" in business management and the region allows to increase many times their general competitiveness and to provide transition of regional economy to new qualitative level. In this regard, the question of whether technologies of "economical production" the main of innovative development of regions are becomes very urgent.

Intermediate structure and threshold phenomena

International Nuclear Information System (INIS)

Hategan, Cornel

2004-01-01

The Intermediate Structure, evidenced through microstructures of the neutron strength function, is reflected in open reaction channels as fluctuations in excitation function of nuclear threshold effects. The intermediate state supporting both neutron strength function and nuclear threshold effect is a micro-giant neutron threshold state. (author)

A comparative study of some productive traits in commercial poultry farms in Duhok Region.

OpenAIRE

TAYEB, Ihsan; HASSAN, Siamand; MUSTAFA, Merkhan; SADEQ, Shawkat; AMEEN, Gulizar; HASSAN, Asia; SHEKHU, Nareen

2011-01-01

Commercial Ross 308 hybrid broiler were used in this study to evaluate a number of production parameter's including live body weight, feed intake, feed conversion ratio, production index and mortality rate. Significant differences observed in term of Mortality rate also feed intake between region 1 and both region 2 and 3. The data was collected from three regions in Duhok/ Kurdistan Region, Iraq which then will be compared with each other to identify if there is any significant differen...

A two-dimensional analytical model for channel potential and threshold voltage of short channel dual material gate lightly doped drain MOSFET

International Nuclear Information System (INIS)

Tripathi Shweta

2014-01-01

An analytical model for the channel potential and the threshold voltage of the short channel dual-material-gate lightly doped drain (DMG-LDD) metal—oxide—semiconductor field-effect transistor (MOSFET) is presented using the parabolic approximation method. The proposed model takes into account the effects of the LDD region length, the LDD region doping, the lengths of the gate materials and their respective work functions, along with all the major geometrical parameters of the MOSFET. The impact of the LDD region length, the LDD region doping, and the channel length on the channel potential is studied in detail. Furthermore, the threshold voltage of the device is calculated using the minimum middle channel potential, and the result obtained is compared with the DMG MOSFET threshold voltage to show the improvement in the threshold voltage roll-off. It is shown that the DMG-LDD MOSFET structure alleviates the problem of short channel effects (SCEs) and the drain induced barrier lowering (DIBL) more efficiently. The proposed model is verified by comparing the theoretical results with the simulated data obtained by using the commercially available ATLAS™ 2D device simulator. (interdisciplinary physics and related areas of science and technology)

A two-dimensional analytical model for channel potential and threshold voltage of short channel dual material gate lightly doped drain MOSFET

Science.gov (United States)

Shweta, Tripathi

2014-11-01

An analytical model for the channel potential and the threshold voltage of the short channel dual-material-gate lightly doped drain (DMG-LDD) metal—oxide—semiconductor field-effect transistor (MOSFET) is presented using the parabolic approximation method. The proposed model takes into account the effects of the LDD region length, the LDD region doping, the lengths of the gate materials and their respective work functions, along with all the major geometrical parameters of the MOSFET. The impact of the LDD region length, the LDD region doping, and the channel length on the channel potential is studied in detail. Furthermore, the threshold voltage of the device is calculated using the minimum middle channel potential, and the result obtained is compared with the DMG MOSFET threshold voltage to show the improvement in the threshold voltage roll-off. It is shown that the DMG-LDD MOSFET structure alleviates the problem of short channel effects (SCEs) and the drain induced barrier lowering (DIBL) more efficiently. The proposed model is verified by comparing the theoretical results with the simulated data obtained by using the commercially available ATLAS™ 2D device simulator.

Nuclear threshold effects and neutron strength function

International Nuclear Information System (INIS)

Hategan, Cornel; Comisel, Horia

2003-01-01

One proves that a Nuclear Threshold Effect is dependent, via Neutron Strength Function, on Spectroscopy of Ancestral Neutron Threshold State. The magnitude of the Nuclear Threshold Effect is proportional to the Neutron Strength Function. Evidence for relation of Nuclear Threshold Effects to Neutron Strength Functions is obtained from Isotopic Threshold Effect and Deuteron Stripping Threshold Anomaly. The empirical and computational analysis of the Isotopic Threshold Effect and of the Deuteron Stripping Threshold Anomaly demonstrate their close relationship to Neutron Strength Functions. It was established that the Nuclear Threshold Effects depend, in addition to genuine Nuclear Reaction Mechanisms, on Spectroscopy of (Ancestral) Neutron Threshold State. The magnitude of the effect is proportional to the Neutron Strength Function, in their dependence on mass number. This result constitutes also a proof that the origins of these threshold effects are Neutron Single Particle States at zero energy. (author)

Threshold and channel interaction in cochlear implant users: evaluation of the tripolar electrode configuration.

Science.gov (United States)

Bierer, Julie Arenberg

2007-03-01

The efficacy of cochlear implants is limited by spatial and temporal interactions among channels. This study explores the spatially restricted tripolar electrode configuration and compares it to bipolar and monopolar stimulation. Measures of threshold and channel interaction were obtained from nine subjects implanted with the Clarion HiFocus-I electrode array. Stimuli were biphasic pulses delivered at 1020 pulses/s. Threshold increased from monopolar to bipolar to tripolar stimulation and was most variable across channels with the tripolar configuration. Channel interaction, quantified by the shift in threshold between single- and two-channel stimulation, occurred for all three configurations but was largest for the monopolar and simultaneous conditions. The threshold shifts with simultaneous tripolar stimulation were slightly smaller than with bipolar and were not as strongly affected by the timing of the two channel stimulation as was monopolar. The subjects' performances on clinical speech tests were correlated with channel-to-channel variability in tripolar threshold, such that greater variability was related to poorer performance. The data suggest that tripolar channels with high thresholds may reveal cochlear regions of low neuron survival or poor electrode placement.

The impact of energy production enhancement on environment in wildlife attractive regions

International Nuclear Information System (INIS)

Kabat, M.; Nowak, W.; Sobanski, R.

1995-01-01

Predicted application of improved technology in energy and heat production as well as implementation of new environmental policy assume an increase in energy production. There should be strongly considered utilization of renewable energy sources for wildlife regions and in the neighbourhood. In the paper there are presented possibilities of practice of alternative energy sources for regions located near national parks and wildlife reserves in West Pomerania (Szczecin). (author). 12 refs, 3 figs, 2 tabs

Combined threshold and transverse momentum resummation for inclusive observables

International Nuclear Information System (INIS)

Muselli, Claudio; Forte, Stefano; Ridolfi, Giovanni

2017-01-01

We present a combined resummation for the transverse momentum distribution of a colorless final state in perturbative QCD, expressed as a function of transverse momentum p T and the scaling variable x. Its expression satisfies three requirements: it reduces to standard transverse momentum resummation to any desired logarithmic order in the limit p T →0 for fixed x, up to power suppressed corrections in p T ; it reduces to threshold resummation to any desired logarithmic order in the limit x→1 for fixed p T , up to power suppressed correction in 1−x; upon integration over transverse momentum it reproduces the resummation of the total cross cross at any given logarithmic order in the threshold x→1 limit, up to power suppressed correction in 1−x. Its main ingredient, and our main new result, is a modified form of transverse momentum resummation, which leads to threshold resummation upon integration over p T , and for which we provide a simple closed-form analytic expression in Fourier-Mellin (b,N) space. We give explicit coefficients up to NNLL order for the specific case of Higgs production in gluon fusion in the effective field theory limit. Our result allows for a systematic improvement of the transverse momentum distribution through threshold resummation which holds for all p T , and elucidates the relation between transverse momentum resummation and threshold resummation at the inclusive level, specifically by providing within perturbative QCD a simple derivation of the main consequence of the so-called collinear anomaly of SCET.

Combined threshold and transverse momentum resummation for inclusive observables

Energy Technology Data Exchange (ETDEWEB)

Muselli, Claudio; Forte, Stefano [Tif Lab, Dipartimento di Fisica, Università di Milano and INFN, Sezione di Milano,Via Celoria 16, I-20133 Milano (Italy); Ridolfi, Giovanni [Dipartimento di Fisica, Università di Genova and INFN, Sezione di Genova,Via Dodecaneso 33, I-16146 Genova (Italy)

2017-03-21

We present a combined resummation for the transverse momentum distribution of a colorless final state in perturbative QCD, expressed as a function of transverse momentum p{sub T} and the scaling variable x. Its expression satisfies three requirements: it reduces to standard transverse momentum resummation to any desired logarithmic order in the limit p{sub T}→0 for fixed x, up to power suppressed corrections in p{sub T}; it reduces to threshold resummation to any desired logarithmic order in the limit x→1 for fixed p{sub T}, up to power suppressed correction in 1−x; upon integration over transverse momentum it reproduces the resummation of the total cross cross at any given logarithmic order in the threshold x→1 limit, up to power suppressed correction in 1−x. Its main ingredient, and our main new result, is a modified form of transverse momentum resummation, which leads to threshold resummation upon integration over p{sub T}, and for which we provide a simple closed-form analytic expression in Fourier-Mellin (b,N) space. We give explicit coefficients up to NNLL order for the specific case of Higgs production in gluon fusion in the effective field theory limit. Our result allows for a systematic improvement of the transverse momentum distribution through threshold resummation which holds for all p{sub T}, and elucidates the relation between transverse momentum resummation and threshold resummation at the inclusive level, specifically by providing within perturbative QCD a simple derivation of the main consequence of the so-called collinear anomaly of SCET.

THE USE OF CLUSTER ANALYSIS IN THE RESEARCH ON SHOPPING PREFERENCES REGARDING REGIONAL PRODUCTS FROM LUBELSKIE VOIVODESHIP

Directory of Open Access Journals (Sweden)

Jan Czeczelewski

2017-03-01

Full Text Available An increasing awareness of consumers is reflected in a growing demand for products which are manufactured in a particular way, with unique ingredients, or which are of a particular origin. The analysis of consumers’ preferences makes it possible to define factors which determine the purchase of regional products. The aim of the work was to identify factors which determine the purchase of regional products from Lubelskie Voivodeship on the basis of cluster analysis using Ward’s hierarchical agglomerative clustering method. The research was carried out in 2016 and included 383 individuals. Statistical analysis of results was conducted on the basis of frequency analysis and cluster analysis. According to the respondents, the most frequently purchased regional products included bakery products (47%, dairy products (35.3%, meat (33.3%, and alcoholic beverages (29.4%. Over 53% of the respondents claimed that the prices of regional products are too high, every third person (29.6% concluded that they are reasonable, while slightly over 3% of the respondents said they are low. Television and the Internet as well as close relatives and friends appeared to be the best forms of reaching the client with information concerning regional products when bringing them out on the market. However, the most common places where regional products were purchased were food fairs and festivals. Every second respondent purchased regional products at least once a month. Additionally, it was revealed that the consumers’ income was not a decisive factor when purchasing regional products. Despite financial stability, individuals who could be defined as “rich” in Polish conditions purchased regional products relatively rarely.

The Determinants of Employee Productivity in Regional Office of Bank Negara Indonesia Manado

OpenAIRE

Mokolensang, Pricilia Monica

2013-01-01

A company can achieve success when supported with a good employee productivity that can provide benefits to the company. In banking company such as BNI requires to increase employee productivity that can assist the company in the achievement of the goals of the company itself. This research has the objective to know the factors that drive employee productivity in the Regional Office of BNI Manado. The population examined is all the employees who work in Regional Office of BNI Manado with 70 e...

Study of pp→ppη reaction at threshold

International Nuclear Information System (INIS)

Taleb, A.

1994-11-01

The η production has been studied through the pp → ppη reaction at threshold. Data were taken at the Synchrotron of the ''Laboratoire National Saturne''. The detection in coincidence of the two protons scattered near 0 deg and analysed with the magnetic spectrometer SPES3 allows the reconstruction of missing mass spectra for the η signature. A simulation program which takes into account all the experimental set up characteristics has been realized and tested through the pp → dπ + reaction detected simultaneously with pp → ppη. The generated proton momentum spectra for pp → ppη show a pronounced η mass dependence. This characteristic, connected to the kinematical properties of pp → ppη at threshold, is used to extract the mass of the meson η. The obtained value, m η = 547.65 ± 0.18 MeV, is in good agreement with measurement done recently through the pd → H eη reaction. The total cross section σ t of pp → ppη measured at 1260, 1265 and 1300 MeV presents a strong energy dependence. This cross section increases less with energy than the phase-space. The influence of p-p and η-p final state interactions in our measurements is studied. Our results are compared with theoretical predictions and assess the dominant character of the baryonic resonance N * (1535) in the η mechanism production at threshold. These experimental results give an energy dependence which is not well reproduced by the theoretical predictions. This discrepancy could be an incorrect description of the η-p interaction in the models. (author). 48 refs., 60 figs., 15 tabs

Evaluation of the contributions of four components of gross domestic product in various regions in China.

Science.gov (United States)

Wu, Sanmang; Lei, Yalin; Li, Li

2015-01-01

Four major components influence the growth of the gross domestic product in Chinese provinces: consumption, investment, transnational exports, and inter-provincial exports. By splitting a competitive input-output table into a non-competitive input-output table, this study used an input-output model to measure the contributions of the four components of gross domestic product in various regions in China. We found that international exports drove the growth of the gross domestic product more strongly in the eastern region than in other regions. Investment and inter-provincial exports were the major impetus for gross domestic product growth in the central and western regions. We also found that consumption played a minimal role in driving the growth of the gross domestic product in all regions in China. According to these findings, although various regions can share much in terms of policies to transform the impetus for economic growth, there should be different foci for different regions. Their shared policy is to increase the role of final consumption in stimulating economic growth. Region-specific policies mandate that the eastern region should strengthen the driving force provided by international exports and that the central and western regions should strengthen indigenous growth capabilities by improving scientific innovation, industrial support, and institutional innovation.

Evaluation of the contributions of four components of gross domestic product in various regions in China.

Directory of Open Access Journals (Sweden)

Sanmang Wu

Full Text Available Four major components influence the growth of the gross domestic product in Chinese provinces: consumption, investment, transnational exports, and inter-provincial exports. By splitting a competitive input-output table into a non-competitive input-output table, this study used an input-output model to measure the contributions of the four components of gross domestic product in various regions in China. We found that international exports drove the growth of the gross domestic product more strongly in the eastern region than in other regions. Investment and inter-provincial exports were the major impetus for gross domestic product growth in the central and western regions. We also found that consumption played a minimal role in driving the growth of the gross domestic product in all regions in China. According to these findings, although various regions can share much in terms of policies to transform the impetus for economic growth, there should be different foci for different regions. Their shared policy is to increase the role of final consumption in stimulating economic growth. Region-specific policies mandate that the eastern region should strengthen the driving force provided by international exports and that the central and western regions should strengthen indigenous growth capabilities by improving scientific innovation, industrial support, and institutional innovation.

A New Wavelet Threshold Function and Denoising Application

Directory of Open Access Journals (Sweden)

Lu Jing-yi

2016-01-01

Full Text Available In order to improve the effects of denoising, this paper introduces the basic principles of wavelet threshold denoising and traditional structures threshold functions. Meanwhile, it proposes wavelet threshold function and fixed threshold formula which are both improved here. First, this paper studies the problems existing in the traditional wavelet threshold functions and introduces the adjustment factors to construct the new threshold function basis on soft threshold function. Then, it studies the fixed threshold and introduces the logarithmic function of layer number of wavelet decomposition to design the new fixed threshold formula. Finally, this paper uses hard threshold, soft threshold, Garrote threshold, and improved threshold function to denoise different signals. And the paper also calculates signal-to-noise (SNR and mean square errors (MSE of the hard threshold functions, soft thresholding functions, Garrote threshold functions, and the improved threshold function after denoising. Theoretical analysis and experimental results showed that the proposed approach could improve soft threshold functions with constant deviation and hard threshold with discontinuous function problems. The proposed approach could improve the different decomposition scales that adopt the same threshold value to deal with the noise problems, also effectively filter the noise in the signals, and improve the SNR and reduce the MSE of output signals.

The estimation of phenological thresholds of Saffron cultivation in Isfahan province based on the daily temperature statistics

Directory of Open Access Journals (Sweden)

Gholamabbas Fallahghalhary

2015-04-01

Full Text Available In this research, the statistics of daily temperature of meteorology stations for estimating the probable occurrence of the first and last frost temperature, the phonological thresholds of saffron and its flowering and irrigation dates were explored. Furthermore, by applying different methods, the probabilities of the attained dates in different probability levels were fit in Smada software. The estimated probability level of 95 percent, as the optimum date, was donated for the entire Isfahan province in ArcGIS9/3 software environment using the interpolation method of Cokriging. The time of occurrence of minimum temperatures is under the influence of the geographical and height condition of each region and the first fall season frost occurs in high regions of the eastern half of Isfahan province at the beginning of November and in the low-lying eastern regions in the late December. The occurrence of daily temperature is changeable from the first half of October and the second half of November. From the west to the east of Isfahan, the time of occurrence of this threshold has a delay of about one month. The optimum flowering date of saffron, based on climatic conditions, is from the first half of October to the late of November. By considering the flowering date and daily temperature requirement of saffron, the irrigation date prior to flowering continues from the second half of September in the western parts and the beginning of November in the eastern regions. From the perspective of thermal condition, the western, central, northern and eastern parts of Isfahan province are more suited to the cultivation and development of saffron product. The amount of water requirement in the study area based on evapotranspiration and crop coefficients of saffron occurred in the mid-season, late season and Initial.

Derivation of critical rainfall thresholds for landslide in Sicily

Science.gov (United States)

Caracciolo, Domenico; Arnone, Elisa; Noto, Leonardo V.

2015-04-01

the rainfall fallen 6, 15 and 30 days before each landslide. The antecedent rainfall turned out to be particularly important in triggering landslides. The rainfall thresholds obtained for the Sicily were compared with the regional curves proposed by various authors confirming a good agreement with these.

Threshold behavior in electron-atom scattering

International Nuclear Information System (INIS)

Sadeghpour, H.R.; Greene, C.H.

1996-01-01

Ever since the classic work of Wannier in 1953, the process of treating two threshold electrons in the continuum of a positively charged ion has been an active field of study. The authors have developed a treatment motivated by the physics below the double ionization threshold. By modeling the double ionization as a series of Landau-Zener transitions, they obtain an analytical formulation of the absolute threshold probability which has a leading power law behavior, akin to Wannier's law. Some of the noteworthy aspects of this derivation are that the derivation can be conveniently continued below threshold giving rise to a open-quotes cuspclose quotes at threshold, and that on both sides of the threshold, absolute values of the cross sections are obtained

Nitrogen use efficiency and crop production: Patterns of regional variation in the United States, 1987-2012.

Science.gov (United States)

Swaney, Dennis P; Howarth, Robert W; Hong, Bongghi

2018-04-17

National-level summaries of crop production and nutrient use efficiency, important for international comparisons, only partially elucidate agricultural dynamics within a country. Agricultural production and associated environmental impacts in large countries vary significantly because of regional differences in crops, climate, resource use and production practices. Here, we review patterns of regional crop production, nitrogen use efficiency (NUE), and major inputs of nitrogen to US crops over 1987-2012, based on the Farm Resource Regions developed by the Economic Research Service (USDA-ERS). Across the US, NUE generally decreased over time over the period studied, mainly due to increased use in mineral N fertilizer above crop N requirements. The Heartland region dominates production of major crops and thus tends to drive national patterns, showing linear response of crop production to nitrogen inputs broadly consistent with an earlier analysis of global patterns of country-scale data by Lassaletta et al. (2014). Most other regions show similar responses, but the Eastern Uplands region shows a negative response to nitrogen inputs, and the Southern Seaboard shows no significant relationship. The regional differences appear as two branches in the response of aggregate production to N inputs on a cropland area basis, but not on a total area basis, suggesting that the type of scaling used is critical under changing cropland area. Nitrogen use efficiency (NUE) is positively associated with fertilizer as a percentage of N inputs in four regions, and all regions considered together. NUE is positively associated with crop N fixation in all regions except Northern Great Plains. It is negatively associated with manure (livestock excretion); in the US, manure is still treated largely as a waste to be managed rather than a nutrient resource. This significant regional variation in patterns of crop production and NUE vs N inputs, has implications for environmental quality and

Occurrence of Aflatoxin M1 in Dairy Products in Southern Italy

Directory of Open Access Journals (Sweden)

Giovanna Barbuti

2008-12-01

Full Text Available A screening survey of the presence of aflatoxin M1 (AFM1 was carried out on 265 samples of cheese made from cow, buffalo, goat, sheep, sheep-goat milk collected in the Apulia region (Southern Italy. Selected samples included unripened, medium and long-term ripened cheeses. AFM1 was found in 16.6% of the analyzed samples. The highest positive incidence was for medium and long-term ripened cheeses, especially those made from sheep-goat milk, while buffalo cheeses tested consistently negative. Our results show that the level of contamination by AFM1 in dairy products from Apulia Region are lower than in other Italian and European regions. Moreover, it is important to underline that a common European norm concerning the AFM1 threshold limits for dairy products is still lacking.

Study of a spherical gaseous detector for research of rare events at low energy threshold

International Nuclear Information System (INIS)

Dastgheibi-Fard, Ali

2014-01-01

The Spherical gaseous detector (or Spherical Proportional Counter, SPC) is a novel type of a particle detector, with a broad range of applications. Its main features include a very low energy threshold which is independent of the volume (due to its very low capacitance), a good energy resolution, robustness and a single detection readout channel. SEDINE, a low background detector installed at the underground site of Laboratoire Souterrain de Modane is currently being operated and aims at measuring events at a very low energy threshold, around 40 eV. The sensitivity for the rare events detection at low energy is correlated to the detector background and to the decreasing the level of energy threshold, which was the main point of this thesis. A major effort has been devoted to the operating of the experimental detector. Several detection parameters were optimized: the electric field homogeneity in the sphere, keeping clear of sparks, the electronic noise level and the leak rate of the detector. The detector is optimized for operation with a high pressure stable gain. The modification of the shield, cleanings of the detector and the addition of an anti-Radon tent have significantly reduced the background of SEDINE. Progress has increased the sensitivity of the detector at low energy up to a value comparable to the results other underground research experiences for the low mass WIMPs. We will present the results with a measured background in the region of keV, which has allowed us to show a competitive figure of exclusion for the production of light dark matter. (author) [fr

Characterization of residual biomass from the Arequipa region for the production of biofuels

Directory of Open Access Journals (Sweden)

María Laura Stronguiló Leturia

2015-12-01

Full Text Available The aim of this work is to select residual biomass from the Arequipa Region for the production of biofuels (biodiesel, bioethanol and biogas. In each case, the initial point is a matrix based on products with residual biomass available in the region, from the agricultural and livestock sectors, information that was obtained from the regional Management of Agriculture web site. Specific factors of the resudue that will be used as raw material for each biofuel production would be considered for the selection process. For the production of biodiesel it is necessary to start from the oil extracted from oilseeds. Regarding obtaining bioethanol, it requires that the residual biomass has high percent of cellulose. With regard to the generation of biogas, we will use animal droppings. Finally, the raw materials selected are: squash and avocado seeds for biodiesel, rice chaff and deseeded corncob for bioethanol and cow and sheep droppings for biogas

Establishing seasonal and alert influenza thresholds in Cambodia using the WHO method: implications for effective utilization of influenza surveillance in the tropics and subtropics.

Science.gov (United States)

Ly, Sovann; Arashiro, Takeshi; Ieng, Vanra; Tsuyuoka, Reiko; Parry, Amy; Horwood, Paul; Heng, Seng; Hamid, Sarah; Vandemaele, Katelijn; Chin, Savuth; Sar, Borann; Arima, Yuzo

2017-01-01

To establish seasonal and alert thresholds and transmission intensity categories for influenza to provide timely triggers for preventive measures or upscaling control measures in Cambodia. Using Cambodia's influenza-like illness (ILI) and laboratory-confirmed influenza surveillance data from 2009 to 2015, three parameters were assessed to monitor influenza activity: the proportion of ILI patients among all outpatients, proportion of ILI samples positive for influenza and the product of the two. With these parameters, four threshold levels (seasonal, moderate, high and alert) were established and transmission intensity was categorized based on a World Health Organization alignment method. Parameters were compared against their respective thresholds. Distinct seasonality was observed using the two parameters that incorporated laboratory data. Thresholds established using the composite parameter, combining syndromic and laboratory data, had the least number of false alarms in declaring season onset and were most useful in monitoring intensity. Unlike in temperate regions, the syndromic parameter was less useful in monitoring influenza activity or for setting thresholds. Influenza thresholds based on appropriate parameters have the potential to provide timely triggers for public health measures in a tropical country where monitoring and assessing influenza activity has been challenging. Based on these findings, the Ministry of Health plans to raise general awareness regarding influenza among the medical community and the general public. Our findings have important implications for countries in the tropics/subtropics and in resource-limited settings, and categorized transmission intensity can be used to assess severity of potential pandemic influenza as well as seasonal influenza.

Threshold friction velocity influenced by wetness of soils within the Columbia Plateau

Science.gov (United States)

Windblown dust impacts air quality in the Columbia Plateau of the U.S. Pacific Northwest. Wind erosion of agricultural lands, which is the predominate source of windblown dust in the region, occurs when the friction velocity exceeds the threshold friction velocity (TFV) of the surface. Soil moisture...

Analysing biodiversity and conservation knowledge products to support regional environmental assessments.

Science.gov (United States)

Brooks, Thomas M; Akçakaya, H Resit; Burgess, Neil D; Butchart, Stuart H M; Hilton-Taylor, Craig; Hoffmann, Michael; Juffe-Bignoli, Diego; Kingston, Naomi; MacSharry, Brian; Parr, Mike; Perianin, Laurence; Regan, Eugenie C; Rodrigues, Ana S L; Rondinini, Carlo; Shennan-Farpon, Yara; Young, Bruce E

2016-02-16

Two processes for regional environmental assessment are currently underway: the Global Environment Outlook (GEO) and Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). Both face constraints of data, time, capacity, and resources. To support these assessments, we disaggregate three global knowledge products according to their regions and subregions. These products are: The IUCN Red List of Threatened Species, Key Biodiversity Areas (specifically Important Bird &Biodiversity Areas [IBAs], and Alliance for Zero Extinction [AZE] sites), and Protected Planet. We present fourteen Data citations: numbers of species occurring and percentages threatened; numbers of endemics and percentages threatened; downscaled Red List Indices for mammals, birds, and amphibians; numbers, mean sizes, and percentage coverages of IBAs and AZE sites; percentage coverage of land and sea by protected areas; and trends in percentages of IBAs and AZE sites wholly covered by protected areas. These data will inform the regional/subregional assessment chapters on the status of biodiversity, drivers of its decline, and institutional responses, and greatly facilitate comparability and consistency between the different regional/subregional assessments.

Analysing biodiversity and conservation knowledge products to support regional environmental assessments

Science.gov (United States)

Brooks, Thomas M.; Akçakaya, H. Resit; Burgess, Neil D.; Butchart, Stuart H. M.; Hilton-Taylor, Craig; Hoffmann, Michael; Juffe-Bignoli, Diego; Kingston, Naomi; Macsharry, Brian; Parr, Mike; Perianin, Laurence; Regan, Eugenie C.; Rodrigues, Ana S. L.; Rondinini, Carlo; Shennan-Farpon, Yara; Young, Bruce E.

2016-02-01

Two processes for regional environmental assessment are currently underway: the Global Environment Outlook (GEO) and Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). Both face constraints of data, time, capacity, and resources. To support these assessments, we disaggregate three global knowledge products according to their regions and subregions. These products are: The IUCN Red List of Threatened Species, Key Biodiversity Areas (specifically Important Bird & Biodiversity Areas [IBAs], and Alliance for Zero Extinction [AZE] sites), and Protected Planet. We present fourteen Data citations: numbers of species occurring and percentages threatened; numbers of endemics and percentages threatened; downscaled Red List Indices for mammals, birds, and amphibians; numbers, mean sizes, and percentage coverages of IBAs and AZE sites; percentage coverage of land and sea by protected areas; and trends in percentages of IBAs and AZE sites wholly covered by protected areas. These data will inform the regional/subregional assessment chapters on the status of biodiversity, drivers of its decline, and institutional responses, and greatly facilitate comparability and consistency between the different regional/subregional assessments.

Analysing biodiversity and conservation knowledge products to support regional environmental assessments

Science.gov (United States)

Brooks, Thomas M.; Akçakaya, H. Resit; Burgess, Neil D.; Butchart, Stuart H.M.; Hilton-Taylor, Craig; Hoffmann, Michael; Juffe-Bignoli, Diego; Kingston, Naomi; MacSharry, Brian; Parr, Mike; Perianin, Laurence; Regan, Eugenie C.; Rodrigues, Ana S.L.; Rondinini, Carlo; Shennan-Farpon, Yara; Young, Bruce E.

2016-01-01

Two processes for regional environmental assessment are currently underway: the Global Environment Outlook (GEO) and Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). Both face constraints of data, time, capacity, and resources. To support these assessments, we disaggregate three global knowledge products according to their regions and subregions. These products are: The IUCN Red List of Threatened Species, Key Biodiversity Areas (specifically Important Bird & Biodiversity Areas [IBAs], and Alliance for Zero Extinction [AZE] sites), and Protected Planet. We present fourteen Data citations: numbers of species occurring and percentages threatened; numbers of endemics and percentages threatened; downscaled Red List Indices for mammals, birds, and amphibians; numbers, mean sizes, and percentage coverages of IBAs and AZE sites; percentage coverage of land and sea by protected areas; and trends in percentages of IBAs and AZE sites wholly covered by protected areas. These data will inform the regional/subregional assessment chapters on the status of biodiversity, drivers of its decline, and institutional responses, and greatly facilitate comparability and consistency between the different regional/subregional assessments. PMID:26881749

Nuclear photo-meson productions in the 1 GeV energy region

International Nuclear Information System (INIS)

Maeda, Kazushige

1991-01-01

Experimental studies of nuclear photomeson productions in the 1 GeV energy region are discussed. In this energy region, π ± , K + and (η) mesons whose life time (or widths) are enough long (narrow) to use spectroscopic study can be produced. This report focuses a possibility of electro-magnetic K + . productions on nuclei. A preliminary result of a photo-kaon test experiment carried out at electron synchrotron laboratory, Institute for Nuclear Study, University of Tokyo are presented. In this experiment, the particle identification method to select Kaon events has been established. We have performed a first measurement of nuclear photo-kaon cross section. (author)

Near-threshold quantization and scattering for deep potentials with attractive tails

International Nuclear Information System (INIS)

Eltschka, Christopher; Moritz, Michael J.; Friedrich, Harald

2000-01-01

Near-threshold properties of bound and continuum states in a deep potential with an attractive tail depend essentially on a few 'tail parameters', which are determined by the properties of the potential tail beyond the region of r-values where WKB wavefunctions are accurate solutions of the Schroedinger equation. One of these tail parameters is a length parameter which defines the singular contribution to the level density just below threshold and the reflectivity of the tail of the potential just above threshold; another is a phase difference which, together with the length parameter, determines the mean scattering length. The near-threshold quantization rule and the actual scattering length are determined by the tail parameters together with a dimensionless constant depending on the zero-energy value of the WKB action integral. We study potentials with tails consisting of two inverse-power terms, V(r)∼-C α /r α -C α 1 /r α 1 ,α 1 >α>2and we derive exact analytical expressions for the tail parameters in the special case α 1 =2(α-1). This enables us to demonstrate the effect of a significant non-homogeneity of the potential tail on the results derived previously for homogeneous tails. (author)

The adaptive value of gluttony: predators mediate the life history trade-offs of satiation threshold.

Science.gov (United States)

Pruitt, J N; Krauel, J J

2010-10-01

Animals vary greatly in their tendency to consume large meals. Yet, whether or how meal size influences fitness in wild populations is infrequently considered. Using a predator exclusion, mark-recapture experiment, we estimated selection on the amount of food accepted during an ad libitum feeding bout (hereafter termed 'satiation threshold') in the wolf spider Schizocosa ocreata. Individually marked, size-matched females of known satiation threshold were assigned to predator exclusion and predator inclusion treatments and tracked for a 40-day period. We also estimated the narrow-sense heritability of satiation threshold using dam-on-female-offspring regression. In the absence of predation, high satiation threshold was positively associated with larger and faster egg case production. However, these selective advantages were lost when predators were present. We estimated the heritability of satiation threshold to be 0.56. Taken together, our results suggest that satiation threshold can respond to selection and begets a life history trade-off in this system: high satiation threshold individuals tend to produce larger egg cases but also suffer increased susceptibility to predation. © 2010 The Authors. Journal Compilation © 2010 European Society For Evolutionary Biology.

Application of pentacene thin-film transistors with controlled threshold voltages to enhancement/depletion inverters

Science.gov (United States)

Takahashi, Hajime; Hanafusa, Yuki; Kimura, Yoshinari; Kitamura, Masatoshi

2018-03-01

Oxygen plasma treatment has been carried out to control the threshold voltage in organic thin-film transistors (TFTs) having a SiO2 gate dielectric prepared by rf sputtering. The threshold voltage linearly changed in the range of -3.7 to 3.1 V with the increase in plasma treatment time. Although the amount of change is smaller than that for organic TFTs having thermally grown SiO2, the tendency of the change was similar to that for thermally grown SiO2. To realize different plasma treatment times on the same substrate, a certain region on the SiO2 surface was selected using a shadow mask, and was treated with oxygen plasma. Using the process, organic TFTs with negative threshold voltages and those with positive threshold voltages were fabricated on the same substrate. As a result, enhancement/depletion inverters consisting of the organic TFTs operated at supply voltages of 5 to 15 V.

Injury Thresholds for Topical Cream-Coated Skin of Hairless Guinea Pigs (Cavia Procellus) in Near Infrared Region

National Research Council Canada - National Science Library

Stolarski, David J; Zohner, Justin J; Imholte, Michelle L; Chavey, Lucas J; Pocock, Ginger M; Buchanan, Kelvin C; Jindra, Nichole M; Figueroa, Manuel A; Thomas, Robert J; Rockwell, Benjamin A

2006-01-01

.... Hairless guinea pigs (cavia porcellus) in vivo were used to evaluate how the minimum visible lesion threshold for single-pulse laser exposure is changed with a topical agent applied to the skin...

A common microstructure in behavioral hearing thresholds and stimulus-frequency otoacoustic emissions.

Science.gov (United States)

Dewey, James B; Dhar, Sumitrajit

2017-11-01

Behavioral hearing thresholds and otoacoustic emission (OAE) spectra often exhibit quasiperiodic fluctuations with frequency. For behavioral and OAE responses to single tones-the latter referred to as stimulus-frequency otoacoustic emissions (SFOAEs)-this microstructure has been attributed to intracochlear reflections of SFOAE energy between its region of generation and the middle ear boundary. However, the relationship between behavioral and SFOAE microstructures, as well as their presumed dependence on the properties of the SFOAE-generation mechanism, have yet to be adequately examined. To address this, behavioral thresholds and SFOAEs evoked by near-threshold tones were compared in 12 normal-hearing female subjects. The microstructures observed in thresholds and both SFOAE amplitudes and delays were found to be strikingly similar. SFOAE phase accumulated an integer number of cycles between the frequencies of microstructure maxima, consistent with a dependence of microstructure periodicity on SFOAE propagation delays. Additionally, microstructure depth was correlated with SFOAE magnitude in a manner resembling that predicted by the intracochlear reflection framework, after assuming reasonable values of parameters related to middle ear transmission. Further exploration of this framework may yield more precise estimates of such parameters and provide insight into their frequency dependence.

Threshold Differences on Figure and Ground: Gelb and Granit (1923).

Science.gov (United States)

Kinateder, Max; Nelson, Rolf

2017-01-01

In 1923, Gelb and Granit, using a method of adjustment for a small red light, reported a lower threshold for the target when presented on a ground region than on an adjacent figural region. More recent work in perceptual organization has found precisely the opposite-a processing advantage seems to go to items presented on the figure, not the ground. Although Gelb and Granit continue to be cited for their finding, it has not previously been available as an English translation. Understanding their methodology and results is important for integrating early Gestalt theory with more recent investigations.

Threshold Differences on Figure and Ground: Gelb and Granit (1923)

Science.gov (United States)

Kinateder, Max

2017-01-01

In 1923, Gelb and Granit, using a method of adjustment for a small red light, reported a lower threshold for the target when presented on a ground region than on an adjacent figural region. More recent work in perceptual organization has found precisely the opposite—a processing advantage seems to go to items presented on the figure, not the ground. Although Gelb and Granit continue to be cited for their finding, it has not previously been available as an English translation. Understanding their methodology and results is important for integrating early Gestalt theory with more recent investigations. PMID:28286640

JAERI's activities on photon production data

International Nuclear Information System (INIS)

Shibata, Keiichi; Maekawa, Fujio; Niita, Koji

1996-01-01

Summarized are activities on photon production data at JAERI. The activities consists of evaluation of photon production data for JENDL Fusion File, benchmark tests of JENDL and FENDL-1 data, and calculation of photon production data in the framework of the Quantum Molecular Dynamics. The capture cross sections of 12 C and 16 O were evaluated for JENDL Fusion File by taking account of the direct radiative capture calculations obtained by A. Mengoni (ENEA). The presently evaluated data are in good agreement with the measurements of Igashira et al. in the keV region, describing the behaviour of p-wave capture which is in proportion to υ. Photon production data on Fe and Ni were updated for JENDL Fusion File by using a statistical-model calculations. According to the results of benchmark tests, the calculations with the updated data reproduce the integral measurements on gamma-ray heating. Benchmark tests of evaluated photon production data have been continued by analyzing the integral experimental performed at OKTAVIAN and FNS. The calculations with JENDL Fusion File are in good agreement with the integral measurements. Preliminary calculation of photon production data in the high energy region has been done in the framework of the Quantum Molecular Dynamics approach. The quasi-deuteron model was used to describe photon absorption in the low energy region. Above pion production threshold, pion production channels were included in the calculation. The neutron-proton bremsstrahlung obtained with the one-boson-exchange model was incorporated into QMD codes. (Abstract only)

Small-threshold behaviour of two-loop self-energy diagrams: two-particle thresholds

International Nuclear Information System (INIS)

Berends, F.A.; Davydychev, A.I.; Moskovskij Gosudarstvennyj Univ., Moscow; Smirnov, V.A.; Moskovskij Gosudarstvennyj Univ., Moscow

1996-01-01

The behaviour of two-loop two-point diagrams at non-zero thresholds corresponding to two-particle cuts is analyzed. The masses involved in a cut and the external momentum are assumed to be small as compared to some of the other masses of the diagram. By employing general formulae of asymptotic expansions of Feynman diagrams in momenta and masses, we construct an algorithm to derive analytic approximations to the diagrams. In such a way, we calculate several first coefficients of the expansion. Since no conditions on relative values of the small masses and the external momentum are imposed, the threshold irregularities are described analytically. Numerical examples, using diagrams occurring in the standard model, illustrate the convergence of the expansion below the first large threshold. (orig.)

Ultrahigh Error Threshold for Surface Codes with Biased Noise

Science.gov (United States)

Tuckett, David K.; Bartlett, Stephen D.; Flammia, Steven T.

2018-02-01

We show that a simple modification of the surface code can exhibit an enormous gain in the error correction threshold for a noise model in which Pauli Z errors occur more frequently than X or Y errors. Such biased noise, where dephasing dominates, is ubiquitous in many quantum architectures. In the limit of pure dephasing noise we find a threshold of 43.7(1)% using a tensor network decoder proposed by Bravyi, Suchara, and Vargo. The threshold remains surprisingly large in the regime of realistic noise bias ratios, for example 28.2(2)% at a bias of 10. The performance is, in fact, at or near the hashing bound for all values of the bias. The modified surface code still uses only weight-4 stabilizers on a square lattice, but merely requires measuring products of Y instead of Z around the faces, as this doubles the number of useful syndrome bits associated with the dominant Z errors. Our results demonstrate that large efficiency gains can be found by appropriately tailoring codes and decoders to realistic noise models, even under the locality constraints of topological codes.

Results on light dark matter particles with a low-threshold CRESST-II detector

Energy Technology Data Exchange (ETDEWEB)

Angloher, G.; Iachellini, N.F.; Hauff, D.; Kiefer, M.; Petricca, F.; Proebst, F.; Seidel, W.; Stodolsky, L.; Strauss, R.; Tanzke, A.; Wuestrich, M. [Max-Planck-Institut fuer Physik, Munich (Germany); Bento, A. [Universidade de Coimbra, Departamento de Fisica, Coimbra (Portugal); Bucci, C.; Canonica, L.; Gorla, P.; Pagliarone, C.; Schaeffner, K. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (Italy); Defay, X.; Feilitzsch, F. von; Lanfranchi, J.C.; Muenster, A.; Potzel, W.; Schoenert, S.; Trinh Thi, H.H.; Ulrich, A.; Wawoczny, S.; Willers, M.; Zoeller, A. [Technische Universitaet Muenchen, Physik-Department and Excellence Cluster Universe, Garching (Germany); Erb, A. [Technische Universitaet Muenchen, Physik-Department and Excellence Cluster Universe, Garching (Germany); Walther-Meissner-Institut fuer Tieftemperaturforschung, Garching (Germany); Guetlein, A.; Kluck, H.; Schieck, J.; Tuerkoglu, C. [Institut fuer Hochenergiephysik der Oesterreichischen Akademie der Wissenschaften, Wien (Austria); Atominstitut, Vienna University of Technology, Wien (Austria); Jochum, J.; Loebell, J.; Strandhagen, C.; Uffinger, M.; Usherov, I. [Eberhard-Karls-Universitaet Tuebingen, Tuebingen (Germany); Kraus, H. [University of Oxford, Department of Physics, Oxford (United Kingdom); Reindl, F. [Max-Planck-Institut fuer Physik, Munich (Germany)

2016-01-15

The CRESST-II experiment uses cryogenic detectors to search for nuclear recoil events induced by the elastic scattering of dark matter particles in CaWO{sub 4} crystals. Given the low energy threshold of our detectors in combination with light target nuclei, low mass dark matter particles can be probed with high sensitivity. In this letter we present the results from data of a single detector module corresponding to 52 kg live days. A blind analysis is carried out. With an energy threshold for nuclear recoils of 307 eV we substantially enhance the sensitivity for light dark matter. Thereby, we extend the reach of direct dark matter experiments to the sub- GeV/c{sup 2} region and demonstrate that the energy threshold is the key parameter in the search for low mass dark matter particles. (orig.)

Altered cortical and subcortical connectivity due to infrasound administered near the hearing threshold - Evidence from fMRI.

Directory of Open Access Journals (Sweden)

Markus Weichenberger

Full Text Available In the present study, the brain's response towards near- and supra-threshold infrasound (IS stimulation (sound frequency near-threshold as well as the right superior frontal gyrus (rSFG during the near-threshold condition. In summary, this study is the first to demonstrate that infrasound near the hearing threshold may induce changes of neural activity across several brain regions, some of which are known to be involved in auditory processing, while others are regarded as keyplayers in emotional and autonomic control. These findings thus allow us to speculate on how continuous exposure to (sub-liminal IS could exert a pathogenic influence on the organism, yet further (especially longitudinal studies are required in order to substantialize these findings.

The anti pp yields anti λ λ reaction near threshold

International Nuclear Information System (INIS)

Maher, C.J.

1986-06-01

Measurements of differential and integrated cross sections as well as final state polarizations for the anti p p → anti Λ Λ reaction are presented. The reaction was studied at two incident antiproton momenta (1476.5 MeV/c and 1507.5 MeV/c) corresponding to total center of mass energies of 15.5 MeV and 26.4 MeV above the reaction threshold. The trajectories of charged decay products of the anti Λ and Λ were observed in a multiwire proportional chamber and in two sets of drift chambers. The data were analyzed with a computer program which reconstructed anti p p → anti Λ Λ → anti p π + pπ - events and performed kinematic fitting. The results are compared to several recent meson exchange calculations, and a one-gluon exchange calculation. The experiment was performed at the Low Energy Antiproton Ring (LEAR) at CERN. The data presented represent the first results of the PS185 collaboration's study of the threshold production of hyperon-antihyperon states

Developing a methodological framework for estimating water productivity indicators in water scarce regions

Science.gov (United States)

Mubako, S. T.; Fullerton, T. M.; Walke, A.; Collins, T.; Mubako, G.; Walker, W. S.

2014-12-01

Water productivity is an area of growing interest in assessing the impact of human economic activities on water resources, especially in arid regions. Indicators of water productivity can assist water users in evaluating sectoral water use efficiency, identifying sources of pressure on water resources, and in supporting water allocation rationale under scarcity conditions. This case study for the water-scarce Middle Rio Grande River Basin aims to develop an environmental-economic accounting approach for water use in arid river basins through a methodological framework that relates water use to human economic activities impacting regional water resources. Water uses are coupled to economic transactions, and the complex but mutual relations between various water using sectors estimated. A comparison is made between the calculated water productivity indicators and representative cost/price per unit volume of water for the main water use sectors. Although it contributes very little to regional economic output, preliminary results confirm that Irrigation is among the sectors with the largest direct water use intensities. High economic value and low water use intensity economic sectors in the study region include Manufacturing, Mining, and Steam Electric Power. Water accounting challenges revealed by the study include differences in water management regimes between jurisdictions, and little understanding of the impact of major economic activities on the interaction between surface and groundwater systems in this region. A more comprehensive assessment would require the incorporation of environmental and social sustainability indicators to the calculated water productivity indicators.

Scaling net ecosystem production and net biome production over a heterogeneous region in the Western United States

Science.gov (United States)

D.P. Turner; W.D. Ritts; B.E. Law; W.B. Cohen; Z. Yan; T. Hudiburg; J.L. Campbell; M. Duane

2007-01-01

Bottom-up scaling of net ecosystem production (NEP) and net biome production (NBP) was used to generate a carbon budget for a large heterogeneous region (the state of Oregon, 2.5x105 km2 ) in the Western United States. Landsat resolution (30 m) remote sensing provided the basis for mapping land cover and disturbance history...

Regional Farm Diversity Can Reduce Vulnerability of Food Production to Climate Change

NARCIS (Netherlands)

Reidsma, P.; Ewert, F.A.

2008-01-01

Food production must adapt in the face of climate change. In Europe, projected vulnerability of food production to climate change is particularly high in Mediterranean regions. Increasing agricultural diversity has been suggested as an adaptation strategy, but empirical evidence is lacking. We

Comparing regional precipitation and temperature extremes in climate model and reanalysis products

Directory of Open Access Journals (Sweden)

Oliver Angélil

2016-09-01

Full Text Available A growing field of research aims to characterise the contribution of anthropogenic emissions to the likelihood of extreme weather and climate events. These analyses can be sensitive to the shapes of the tails of simulated distributions. If tails are found to be unrealistically short or long, the anthropogenic signal emerges more or less clearly, respectively, from the noise of possible weather. Here we compare the chance of daily land-surface precipitation and near-surface temperature extremes generated by three Atmospheric Global Climate Models typically used for event attribution, with distributions from six reanalysis products. The likelihoods of extremes are compared for area-averages over grid cell and regional sized spatial domains. Results suggest a bias favouring overly strong attribution estimates for hot and cold events over many regions of Africa and Australia, and a bias favouring overly weak attribution estimates over regions of North America and Asia. For rainfall, results are more sensitive to geographic location. Although the three models show similar results over many regions, they do disagree over others. Equally, results highlight the discrepancy amongst reanalyses products. This emphasises the importance of using multiple reanalysis and/or observation products, as well as multiple models in event attribution studies.

Coherent π0 electroproduction on the deuteron at threshold

International Nuclear Information System (INIS)

Jeon, B.K.; Sato, T.; Ohtsubo, H.

1989-01-01

We studied the effect of the exchange current on the longitudinal form factor of neutral pion electroproduction. As a result, we obtained a large effect of the exchange current on pion production at threshold with a momentum transfer of 2-3 fm -1 . This reaction may serve as a clear test of the exchange current, which is related to the exchange axial-charge. (orig.)

Green Net Regional Product for the San Luis Basin, Colorado: An Economic Measure of Regional Sustainability

Science.gov (United States)

This paper presents the data sources and methodology used to estimate Green Net Regional Product (GNRP), a green accounting approach, for the San Luis Basin (SLB). GNRP is equal to aggregate consumption minus the depreciation of man-made and natural capital. We measure the move...

Hyper-arousal decreases human visual thresholds.

Directory of Open Access Journals (Sweden)

Adam J Woods

Full Text Available Arousal has long been known to influence behavior and serves as an underlying component of cognition and consciousness. However, the consequences of hyper-arousal for visual perception remain unclear. The present study evaluates the impact of hyper-arousal on two aspects of visual sensitivity: visual stereoacuity and contrast thresholds. Sixty-eight participants participated in two experiments. Thirty-four participants were randomly divided into two groups in each experiment: Arousal Stimulation or Sham Control. The Arousal Stimulation group underwent a 50-second cold pressor stimulation (immersing the foot in 0-2° C water, a technique known to increase arousal. In contrast, the Sham Control group immersed their foot in room temperature water. Stereoacuity thresholds (Experiment 1 and contrast thresholds (Experiment 2 were measured before and after stimulation. The Arousal Stimulation groups demonstrated significantly lower stereoacuity and contrast thresholds following cold pressor stimulation, whereas the Sham Control groups showed no difference in thresholds. These results provide the first evidence that hyper-arousal from sensory stimulation can lower visual thresholds. Hyper-arousal's ability to decrease visual thresholds has important implications for survival, sports, and everyday life.

Colour thresholding and objective quantification in bioimaging

Science.gov (United States)

Fermin, C. D.; Gerber, M. A.; Torre-Bueno, J. R.

1992-01-01

Computer imaging is rapidly becoming an indispensable tool for the quantification of variables in research and medicine. Whilst its use in medicine has largely been limited to qualitative observations, imaging in applied basic sciences, medical research and biotechnology demands objective quantification of the variables in question. In black and white densitometry (0-256 levels of intensity) the separation of subtle differences between closely related hues from stains is sometimes very difficult. True-colour and real-time video microscopy analysis offer choices not previously available with monochrome systems. In this paper we demonstrate the usefulness of colour thresholding, which has so far proven indispensable for proper objective quantification of the products of histochemical reactions and/or subtle differences in tissue and cells. In addition, we provide interested, but untrained readers with basic information that may assist decisions regarding the most suitable set-up for a project under consideration. Data from projects in progress at Tulane are shown to illustrate the advantage of colour thresholding over monochrome densitometry and for objective quantification of subtle colour differences between experimental and control samples.

PRODUCERS’ PERCEPTION OF GEOGRAPHICAL INDICATIONS AS A PRODUCT DIVERSIFICATION TOOL FOR AGRIFOOD PRODUCTS IN SEMI-ARID REGIONS OF KENYA

Directory of Open Access Journals (Sweden)

Fredah Wangui Maina

2018-04-01

Full Text Available The study assessed producers’ awareness and perceptions of territorial-based qualities and the economic potential of two potential origin-based geographical indications in two semi-arid counties in Kenya. Protection of the origin products as geographical indications is presented as an option for ecosystem approach in managing fragile semi-arid regions while providing producers economic incentives and social inclusion; key components of green growth. Factor analysis was conducted on Likert scale perception questions administered to producers of goats (Baringo and mangoes (Makueni. The producers were aware of the uniqueness of their products and its geographical source. The resultant factors reveal the importance of public policies, institutions, market access and public sector actors as important to producers’ perception of the success of protecting their products as geographical indications. Clustering revealed producer heterogeneity in their perceptions of protecting their respective products as geographical indications. The constitution of the clusters was significantly different based on the number of years the producers had practiced farming in the region, their awareness of the uniqueness of their goats, income received from goat production and institutional factors. Enhanced collective action for both goats and mangoes in the semi-arid regions would ensure collective reputation in the product presented to the market. The producers’ perceptions emphasise geographical indications as a marketing tool rather than an environmental tool, agreeing with Principle 4 of the ecosystem approach on managing ecosystem in an economic context.

A numerical study of threshold states

International Nuclear Information System (INIS)

Ata, M.S.; Grama, C.; Grama, N.; Hategan, C.

1979-01-01

There are some experimental evidences of charged particle threshold states. On the statistical background of levels, some simple structures were observed in excitation spectrum. They occur near the coulombian threshold and have a large reduced width for the decay in the threshold channel. These states were identified as charged cluster threshold states. Such threshold states were observed in sup(15,16,17,18)O, sup(18,19)F, sup(19,20)Ne, sup(24)Mg, sup(32)S. The types of clusters involved were d, t, 3 He, α and even 12 C. They were observed in heavy-ions transfer reactions in the residual nucleus as strong excited levels. The charged particle threshold states occur as simple structures at high excitation energy. They could be interesting both from nuclear structure as well as nuclear reaction mechanism point of view. They could be excited as simple structures both in compound and residual nucleus. (author)

Effect of low-frequency deep brain stimulation on sensory thresholds in Parkinson's disease.

Science.gov (United States)

Belasen, Abigail; Rizvi, Khizer; Gee, Lucy E; Yeung, Philip; Prusik, Julia; Ramirez-Zamora, Adolfo; Hanspal, Era; Paiva, Priscilla; Durphy, Jennifer; Argoff, Charles E; Pilitsis, Julie G

2017-02-01

OBJECTIVE Chronic pain is a major distressing symptom of Parkinson's disease (PD) that is often undertreated. Subthalamic nucleus (STN) deep brain stimulation (DBS) delivers high-frequency stimulation (HFS) to patients with PD and has been effective in pain relief in a subset of these patients. However, up to 74% of patients develop new pain concerns while receiving STN DBS. Here the authors explore whether altering the frequency of STN DBS changes pain perception as measured through quantitative sensory testing (QST). METHODS Using QST, the authors measured thermal and mechanical detection and pain thresholds in 19 patients undergoing DBS via HFS, low-frequency stimulation (LFS), and off conditions in a randomized order. Testing was performed in the region of the body with the most pain and in the lower back in patients without chronic pain. RESULTS In the patients with chronic pain, LFS significantly reduced heat detection thresholds as compared with thresholds following HFS (p = 0.029) and in the off state (p = 0.010). Moreover, LFS resulted in increased detection thresholds for mechanical pressure (p = 0.020) and vibration (p = 0.040) compared with these thresholds following HFS. Neither LFS nor HFS led to changes in other mechanical thresholds. In patients without chronic pain, LFS significantly increased mechanical pain thresholds in response to the 40-g pinprick compared with thresholds following HFS (p = 0.032). CONCLUSIONS Recent literature has suggested that STN LFS can be useful in treating nonmotor symptoms of PD. Here the authors demonstrated that LFS modulates thermal and mechanical detection to a greater extent than HFS. Low-frequency stimulation is an innovative means of modulating chronic pain in PD patients receiving STN DBS. The authors suggest that STN LFS may be a future option to consider when treating Parkinson's patients in whom pain remains the predominant complaint.

Determinants of milk production in FADN dairy farms in the regions of the European Union with predominance of intensive production in 2011

Directory of Open Access Journals (Sweden)

Guth Marta

2016-12-01

Full Text Available The main aim of the considerations was to determine the factors determining the variability of milk production in selected macroregions of the European Union. The regions were selected on the basis of the analysis of the diversity of dairy farms FADN in the regions of the European Union, which was determined by the agglomeration cluster analysis using Ward method. In order to highlight the determinants of production there was factor analysis made. On the basis of the results of factor analysis there were factors that have a decisive impact on milk production in dairy farms from areas with a predominance of intensive production identified, and there was a possibility to find out which macro-regions of the European Union reached a relatively best and worst performance in terms of the distinguished factors.

Evaluation of the cross-sections of threshold reactions leading to the production of long-lived radionuclides during irradiation of steels by thermonuclear spectrum neutrons

International Nuclear Information System (INIS)

Blokhin, A.I.; Buleeva, N.N.; Manokhin, V.N.; Mikhajlyukova, M.V.; Nasyrova, S.M.; Skripova, M.V.

2002-01-01

The present paper analyses and evaluates the cross-sections of threshold reactions leading to the production of long-lived radionuclides during the irradiation, by thermonuclear spectrum neutrons, of steels containing V, Ti, Cr, Fe and Ni. On the basis of empirical systematics. a new evaluation of the (n,2n), (n,p), (n,np), (n,α) and (n,nα) excitation functions is made for all isotopes of V, Ti, Cr, Fe and Ni and for intermediate isotopes produced in the chain from irradiated isotopes up to production of the long-lived radionuclides 39 Ar, 42 Ar, 41 Ca, 53 Mn, 60 Fe, 60 Co, 59 Ni and 63 Ni. A comparison is made with the experimental and other evaluated data. (author)

Conceptions of nuclear threshold status

International Nuclear Information System (INIS)

Quester, G.H.

1991-01-01

This paper reviews some alternative definitions of nuclear threshold status. Each of them is important, and major analytical confusions would result if one sense of the term is mistaken for another. The motives for nations entering into such threshold status are a blend of civilian and military gains, and of national interests versus parochial or bureaucratic interests. A portion of the rationale for threshold status emerges inevitably from the pursuit of economic goals, and another portion is made more attraction by the derives of the domestic political process. Yet the impact on international security cannot be dismissed, especially where conflicts among the states remain real. Among the military or national security motives are basic deterrence, psychological warfare, war-fighting and, more generally, national prestige. In the end, as the threshold phenomenon is assayed for lessons concerning the role of nuclear weapons more generally in international relations and security, one might conclude that threshold status and outright proliferation coverage to a degree in the motives for all of the states involved and in the advantages attained. As this paper has illustrated, nuclear threshold status is more subtle and more ambiguous than outright proliferation, and it takes considerable time to sort out the complexities. Yet the world has now had a substantial amount of time to deal with this ambiguous status, and this may tempt more states to exploit it

Gradient-driven flux-tube simulations of ion temperature gradient turbulence close to the non-linear threshold

Energy Technology Data Exchange (ETDEWEB)

Peeters, A. G.; Rath, F.; Buchholz, R.; Grosshauser, S. R.; Strintzi, D.; Weikl, A. [Physics Department, University of Bayreuth, Universitätsstrasse 30, Bayreuth (Germany); Camenen, Y. [Aix Marseille Univ, CNRS, PIIM, UMR 7345, Marseille (France); Candy, J. [General Atomics, PO Box 85608, San Diego, California 92186-5608 (United States); Casson, F. J. [CCFE, Culham Science Centre, Abingdon OX14 3DB, Oxon (United Kingdom); Hornsby, W. A. [Max Planck Institut für Plasmaphysik, Boltzmannstrasse 2 85748 Garching (Germany)

2016-08-15

It is shown that Ion Temperature Gradient turbulence close to the threshold exhibits a long time behaviour, with smaller heat fluxes at later times. This reduction is connected with the slow growth of long wave length zonal flows, and consequently, the numerical dissipation on these flows must be sufficiently small. Close to the nonlinear threshold for turbulence generation, a relatively small dissipation can maintain a turbulent state with a sizeable heat flux, through the damping of the zonal flow. Lowering the dissipation causes the turbulence, for temperature gradients close to the threshold, to be subdued. The heat flux then does not go smoothly to zero when the threshold is approached from above. Rather, a finite minimum heat flux is obtained below which no fully developed turbulent state exists. The threshold value of the temperature gradient length at which this finite heat flux is obtained is up to 30% larger compared with the threshold value obtained by extrapolating the heat flux to zero, and the cyclone base case is found to be nonlinearly stable. Transport is subdued when a fully developed staircase structure in the E × B shearing rate forms. Just above the threshold, an incomplete staircase develops, and transport is mediated by avalanche structures which propagate through the marginally stable regions.

Recent progress of below-threshold harmonic generation

International Nuclear Information System (INIS)

Xiong, Wei-Hao; Peng, Liang-You; Gong, Qihuang

2017-01-01

The harmonics generated from the interaction of a strong laser field with atoms and molecules in the gas phase can be applied as coherent light sources and detecting techniques for structures and dynamics in matter. In the last three decades, the most prevailing experimental and theoretical studies have been focused on the high-order harmonic generation due to its applications in attosecond science. However, low-order harmonics near the ionization threshold of the target have been less explored, partially because the spectrum in this region is more complicated from both the theoretical and experimental point of view. After several pioneering investigations in the mid 1990s, near threshold harmonics (NTHs) begun to draw a great attention again because of the development of high repetition rate cavity enhanced harmonics about 10 years ago. Very recently, NTHs have attracted a lot of experimental and theoretical studies due to their potential applications as light sources and complicated mechanisms. In this topical review, we will summarize the progress of NTHs, including the early and recent experimental measurements in atoms and molecules, as well as the relevant theoretical explorations of these harmonics. (topical review)

NS maize hybrids in production regions of Serbia

Directory of Open Access Journals (Sweden)

Stojaković Milisav

2010-01-01

Full Text Available Fifteen NS maize hybrids of FAO 300-700 maturity groups were evaluated in strip trials (plot size 1,120 m2 at 30 locations in Serbia. In all locations including all production regions, the most yielding hybrid was NS 6030 with average yield of 10.9 t ha-1. The additive Main Effects and Multiplicative Interaction (AMMI and the sites regression (SREG models were used to study basic structure of G x E interactions and the possible existence of different mega-environments in Serbian maize growing regions in 2009. The results of the 15 hybrids x 10 locations for grain yield in maize showed by biplot technique indicate several specific location-hybrid deviations (the AMMI biplot, and possible existence of at least one mega-environment (the GGE biplot. .

Automatic Semiconductor Wafer Image Segmentation for Defect Detection Using Multilevel Thresholding

Directory of Open Access Journals (Sweden)

Saad N.H.

2016-01-01

Full Text Available Quality control is one of important process in semiconductor manufacturing. A lot of issues trying to be solved in semiconductor manufacturing industry regarding the rate of production with respect to time. In most semiconductor assemblies, a lot of wafers from various processes in semiconductor wafer manufacturing need to be inspected manually using human experts and this process required full concentration of the operators. This human inspection procedure, however, is time consuming and highly subjective. In order to overcome this problem, implementation of machine vision will be the best solution. This paper presents automatic defect segmentation of semiconductor wafer image based on multilevel thresholding algorithm which can be further adopted in machine vision system. In this work, the defect image which is in RGB image at first is converted to the gray scale image. Median filtering then is implemented to enhance the gray scale image. Then the modified multilevel thresholding algorithm is performed to the enhanced image. The algorithm worked in three main stages which are determination of the peak location of the histogram, segmentation the histogram between the peak and determination of first global minimum of histogram that correspond to the threshold value of the image. The proposed approach is being evaluated using defected wafer images. The experimental results shown that it can be used to segment the defect correctly and outperformed other thresholding technique such as Otsu and iterative thresholding.

Simulations of charge summing and threshold dispersion effects in Medipix3

International Nuclear Information System (INIS)

Pennicard, D.; Ballabriga, R.; Llopart, X.; Campbell, M.; Graafsma, H.

2011-01-01

A novel feature of the Medipix3 photon-counting pixel readout chip is inter-pixel communication. By summing together the signals from neighbouring pixels at a series of 'summing nodes', and assigning each hit to the node with the highest signal, the chip can compensate for charge-sharing effects. However, previous experimental tests have demonstrated that the node-to-node variation in the detector's response is very large. Using computer simulations, it is shown that this variation is due to threshold dispersion, which results in many hits being assigned to whichever summing node in the vicinity has the lowest threshold level. A reduction in threshold variation would attenuate but not solve this issue. A new charge summing and hit assignment process is proposed, where the signals in individual pixels are used to determine the hit location, and then signals from neighbouring pixels are summed to determine whether the total photon energy is above threshold. In simulation, this new mode accurately assigns each hit to the pixel with the highest pulse height without any losses or double counting. - Research highlights: → Medipix3 readout chip compensates charge sharing using inter-pixel communication. → In initial production run, the flat-field response is unexpectedly nonuniform. → This effect is reproduced in simulation, and is caused by threshold dispersion. → A new inter-pixel communication process is proposed. → Simulations demonstrate the new process should give much better uniformity.

Threshold Concepts in Finance: Student Perspectives

Science.gov (United States)

Hoadley, Susan; Kyng, Tim; Tickle, Leonie; Wood, Leigh N.

2015-01-01

Finance threshold concepts are the essential conceptual knowledge that underpin well-developed financial capabilities and are central to the mastery of finance. In this paper we investigate threshold concepts in finance from the point of view of students, by establishing the extent to which students are aware of threshold concepts identified by…

Threshold irradiation dose for amorphization of silicon carbide

Energy Technology Data Exchange (ETDEWEB)

Snead, L.L.; Zinkle, S.J. [Oak Ridge National Lab., TN (United States)

1997-04-01

The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface of strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be {approximately}0.56 eV. This model successfully explains the difference in the temperature-dependent amorphization behavior of SiC irradiated with 0.56 MeV silicon ions at 1 x 10{sup {minus}3} dpa/s and with fission neutrons irradiated at 1 x 10{sup {minus}6} dpa/s irradiated to 15 dpa in the temperature range of {approximately}340 {+-} 10K.

Threshold irradiation dose for amorphization of silicon carbide

International Nuclear Information System (INIS)

Snead, L.L.; Zinkle, S.J.

1997-01-01

The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface of strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be ∼0.56 eV. This model successfully explains the difference in the temperature-dependent amorphization behavior of SiC irradiated with 0.56 MeV silicon ions at 1 x 10 -3 dpa/s and with fission neutrons irradiated at 1 x 10 -6 dpa/s irradiated to 15 dpa in the temperature range of ∼340 ± 10K

Threshold irradiation dose for amorphization of silicon carbide

International Nuclear Information System (INIS)

Snead, L.L.; Zinkle, S.J.

1997-01-01

The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface or strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be ∼0.56eV. This model successfully explains the difference in the temperature dependent amorphization behavior of SiC irradiated with 0.56 MeV Si + at 1 x 10 -3 dpa/s and with fission neutrons irradiated at 1 x 10 -6 dpa/s irradiated to 15 dpa in the temperature range of ∼340±10K

Near threshold fatigue testing

Science.gov (United States)

Freeman, D. C.; Strum, M. J.

1993-01-01

Measurement of the near-threshold fatigue crack growth rate (FCGR) behavior provides a basis for the design and evaluation of components subjected to high cycle fatigue. Typically, the near-threshold fatigue regime describes crack growth rates below approximately 10(exp -5) mm/cycle (4 x 10(exp -7) inch/cycle). One such evaluation was recently performed for the binary alloy U-6Nb. The procedures developed for this evaluation are described in detail to provide a general test method for near-threshold FCGR testing. In particular, techniques for high-resolution measurements of crack length performed in-situ through a direct current, potential drop (DCPD) apparatus, and a method which eliminates crack closure effects through the use of loading cycles with constant maximum stress intensity are described.

Software thresholds alter the bias of actigraphy for monitoring sleep in team-sport athletes.

Science.gov (United States)

Fuller, Kate L; Juliff, Laura; Gore, Christopher J; Peiffer, Jeremiah J; Halson, Shona L

2017-08-01

Actical ® actigraphy is commonly used to monitor athlete sleep. The proprietary software, called Actiware ® , processes data with three different sleep-wake thresholds (Low, Medium or High), but there is no standardisation regarding their use. The purpose of this study was to examine validity and bias of the sleep-wake thresholds for processing Actical ® sleep data in team sport athletes. Validation study comparing actigraph against accepted gold standard polysomnography (PSG). Sixty seven nights of sleep were recorded simultaneously with polysomnography and Actical ® devices. Individual night data was compared across five sleep measures for each sleep-wake threshold using Actiware ® software. Accuracy of each sleep-wake threshold compared with PSG was evaluated from mean bias with 95% confidence limits, Pearson moment-product correlation and associated standard error of estimate. The Medium threshold generated the smallest mean bias compared with polysomnography for total sleep time (8.5min), sleep efficiency (1.8%) and wake after sleep onset (-4.1min); whereas the Low threshold had the smallest bias (7.5min) for wake bouts. Bias in sleep onset latency was the same across thresholds (-9.5min). The standard error of the estimate was similar across all thresholds; total sleep time ∼25min, sleep efficiency ∼4.5%, wake after sleep onset ∼21min, and wake bouts ∼8 counts. Sleep parameters measured by the Actical ® device are greatly influenced by the sleep-wake threshold applied. In the present study the Medium threshold produced the smallest bias for most parameters compared with PSG. Given the magnitude of measurement variability, confidence limits should be employed when interpreting changes in sleep parameters. Copyright © 2017 Sports Medicine Australia. All rights reserved.

Dynamic-thresholding level set: a novel computer-aided volumetry method for liver tumors in hepatic CT images

Science.gov (United States)

Cai, Wenli; Yoshida, Hiroyuki; Harris, Gordon J.

2007-03-01

Measurement of the volume of focal liver tumors, called liver tumor volumetry, is indispensable for assessing the growth of tumors and for monitoring the response of tumors to oncology treatments. Traditional edge models, such as the maximum gradient and zero-crossing methods, often fail to detect the accurate boundary of a fuzzy object such as a liver tumor. As a result, the computerized volumetry based on these edge models tends to differ from manual segmentation results performed by physicians. In this study, we developed a novel computerized volumetry method for fuzzy objects, called dynamic-thresholding level set (DT level set). An optimal threshold value computed from a histogram tends to shift, relative to the theoretical threshold value obtained from a normal distribution model, toward a smaller region in the histogram. We thus designed a mobile shell structure, called a propagating shell, which is a thick region encompassing the level set front. The optimal threshold calculated from the histogram of the shell drives the level set front toward the boundary of a liver tumor. When the volume ratio between the object and the background in the shell approaches one, the optimal threshold value best fits the theoretical threshold value and the shell stops propagating. Application of the DT level set to 26 hepatic CT cases with 63 biopsy-confirmed hepatocellular carcinomas (HCCs) and metastases showed that the computer measured volumes were highly correlated with those of tumors measured manually by physicians. Our preliminary results showed that DT level set was effective and accurate in estimating the volumes of liver tumors detected in hepatic CT images.

Reconciling threshold and subthreshold expansions for pion-nucleon scattering

Science.gov (United States)

Siemens, D.; Ruiz de Elvira, J.; Epelbaum, E.; Hoferichter, M.; Krebs, H.; Kubis, B.; Meißner, U.-G.

2017-07-01

Heavy-baryon chiral perturbation theory (ChPT) at one loop fails in relating the pion-nucleon amplitude in the physical region and for subthreshold kinematics due to loop effects enhanced by large low-energy constants. Studying the chiral convergence of threshold and subthreshold parameters up to fourth order in the small-scale expansion, we address the question to what extent this tension can be mitigated by including the Δ (1232) as an explicit degree of freedom and/or using a covariant formulation of baryon ChPT. We find that the inclusion of the Δ indeed reduces the low-energy constants to more natural values and thereby improves consistency between threshold and subthreshold kinematics. In addition, even in the Δ-less theory the resummation of 1 /mN corrections in the covariant scheme improves the results markedly over the heavy-baryon formulation, in line with previous observations in the single-baryon sector of ChPT that so far have evaded a profound theoretical explanation.

Reconciling threshold and subthreshold expansions for pion–nucleon scattering

Directory of Open Access Journals (Sweden)

D. Siemens

2017-07-01

Full Text Available Heavy-baryon chiral perturbation theory (ChPT at one loop fails in relating the pion–nucleon amplitude in the physical region and for subthreshold kinematics due to loop effects enhanced by large low-energy constants. Studying the chiral convergence of threshold and subthreshold parameters up to fourth order in the small-scale expansion, we address the question to what extent this tension can be mitigated by including the Δ(1232 as an explicit degree of freedom and/or using a covariant formulation of baryon ChPT. We find that the inclusion of the Δ indeed reduces the low-energy constants to more natural values and thereby improves consistency between threshold and subthreshold kinematics. In addition, even in the Δ-less theory the resummation of 1/mN corrections in the covariant scheme improves the results markedly over the heavy-baryon formulation, in line with previous observations in the single-baryon sector of ChPT that so far have evaded a profound theoretical explanation.

GLOBALIZATION OF ECONOMY AND GREATER CYCLES OF THE TOTAL REGIONAL PRODUCT, INFLATION AND UNEMPLOYMENT

Directory of Open Access Journals (Sweden)

V.A. Belkin

2009-06-01

Full Text Available The process of synchronization of greater and small waves of real gross national product of the USA and a total regional product of the Chelyabinsk area is shown on the materials of economic statistics. The conclusion about defining influence of dynamics of real gross national product of the USA on the basic macroeconomic parameters of the Chelyabinsk area owing to high dependence of its economy on export of metal products is done from here. It is evidently shown, that the modern world economic crisis quite keeps within the theory of greater cycles of an economic conjuncture of N.D. Kondratyev. To greater cycles of a total regional product of the Chelyabinsk area there correspond return greater cycles of inflation and unemployment.

Adapting maize production to drought in the Northeast Farming Region of China

DEFF Research Database (Denmark)

Yin, Xiaogang; Olesen, Jørgen Eivind; Wang, M.

2016-01-01

Maize (Zea mays L.) is the most prominent crop in the Northeast Farming Region of China (NFR), and drought has been the largest limitation for maize production in this area during recent decades. The question of how to adapt maize production to drought has received great attention from policy...

Urban and peri-urban agricultural production along railway tracks: a case study from the Mumbai Metropolitan Region

Directory of Open Access Journals (Sweden)

Prem Jose Vazhacharickal

2013-12-01

Full Text Available Urban and peri-urban agriculture (UPA contributes to food security, serves as an opportunity for income generation, and provides recreational services to urban citizens. With a population of 21 Million people, of which 60 % live in slums, UPA activities can play a crucial role in supporting people’s livelihoods in Mumbai Metropolitan Region (MMR. This study was conducted to characterize the railway gardens, determine their role in UPA production, and assess potential risks. It comprises a baseline survey among 38 railway gardeners across MMR characterized by different demographic, socio-economic, migratory, and labour characteristics. Soil, irrigation water, and plant samples were analyzed for nutrients, heavy metals, and microbial load. All the railway gardeners practiced agriculture as a primary source of income and cultivated seasonal vegetables such as lady’s finger (Abelmoschus esculentus L. Moench, spinach (Spinacia oleracea L., red amaranth (Amaranthus cruentus L., and white radish (Raphanus sativus var. longipinnatus which were irrigated with waste water. This irrigation water was loaded with 7–28 mg N l^(−1, 0.3–7 mg P l^(−1, and 8–32 mg K l^(−1, but also contained heavy metals such as lead (0.02–0.06 mg Pb l^(−1, cadmium (0.03–0.17 mg Cd l^(−1, mercury (0.001–0.005 mg Hg l^(−1, and pathogens such as Escherichia coli (1,100 most probable number per 100 ml. Levels of heavy metals exceeded the critical thresholds in surface soils (Cr, Ni, and Sr and produce (Pb, Cd, and Sr. The railway garden production systems can substantially foster employment and reduce economic deprivation of urban poor particularly slum dwellers and migrant people. However this production system may also cause possible health risks to producers and consumers.

Error threshold inference from Global Precipitation Measurement (GPM) satellite rainfall data and interpolated ground-based rainfall measurements in Metro Manila

Science.gov (United States)

Ampil, L. J. Y.; Yao, J. G.; Lagrosas, N.; Lorenzo, G. R. H.; Simpas, J.

2017-12-01

The Global Precipitation Measurement (GPM) mission is a group of satellites that provides global observations of precipitation. Satellite-based observations act as an alternative if ground-based measurements are inadequate or unavailable. Data provided by satellites however must be validated for this data to be reliable and used effectively. In this study, the Integrated Multisatellite Retrievals for GPM (IMERG) Final Run v3 half-hourly product is validated by comparing against interpolated ground measurements derived from sixteen ground stations in Metro Manila. The area considered in this study is the region 14.4° - 14.8° latitude and 120.9° - 121.2° longitude, subdivided into twelve 0.1° x 0.1° grid squares. Satellite data from June 1 - August 31, 2014 with the data aggregated to 1-day temporal resolution are used in this study. The satellite data is directly compared to measurements from individual ground stations to determine the effect of the interpolation by contrast against the comparison of satellite data and interpolated measurements. The comparisons are calculated by taking a fractional root-mean-square error (F-RMSE) between two datasets. The results show that interpolation improves errors compared to using raw station data except during days with very small amounts of rainfall. F-RMSE reaches extreme values of up to 654 without a rainfall threshold. A rainfall threshold is inferred to remove extreme error values and make the distribution of F-RMSE more consistent. Results show that the rainfall threshold varies slightly per month. The threshold for June is inferred to be 0.5 mm, reducing the maximum F-RMSE to 9.78, while the threshold for July and August is inferred to be 0.1 mm, reducing the maximum F-RMSE to 4.8 and 10.7, respectively. The maximum F-RMSE is reduced further as the threshold is increased. Maximum F-RMSE is reduced to 3.06 when a rainfall threshold of 10 mm is applied over the entire duration of JJA. These results indicate that

At-Risk-of-Poverty Threshold

Directory of Open Access Journals (Sweden)

Táňa Dvornáková

2012-06-01

Full Text Available European Statistics on Income and Living Conditions (EU-SILC is a survey on households’ living conditions. The main aim of the survey is to get long-term comparable data on social and economic situation of households. Data collected in the survey are used mainly in connection with the evaluation of income poverty and determinationof at-risk-of-poverty rate. This article deals with the calculation of the at risk-of-poverty threshold based on data from EU-SILC 2009. The main task is to compare two approaches to the computation of at riskof-poverty threshold. The first approach is based on the calculation of the threshold for each country separately,while the second one is based on the calculation of the threshold for all states together. The introduction summarizes common attributes in the calculation of the at-risk-of-poverty threshold, such as disposable household income, equivalised household income. Further, different approaches to both calculations are introduced andadvantages and disadvantages of these approaches are stated. Finally, the at-risk-of-poverty rate calculation is described and comparison of the at-risk-of-poverty rates based on these two different approaches is made.

The Effect of China’s New Circular Collective Forest Tenure Reform on Household Non-Timber Forest Product Production in Natural Forest Protection Project Regions

Directory of Open Access Journals (Sweden)

Yang Ren

2018-04-01

Full Text Available The implementation of China’s natural forest protection project (Protection Project in 1998 changed households’ forestry production modes in project regions, and China’s new circular collective forest tenure reform (Tenure Reform has been implemented since 2003 with the goal of motivating household forestry production and increasing household income from forests. Policymakers expect that Tenure Reform could also stimulate households to engage in non-timber forest products (NTFPs production in Protection Project regions. However, only a few studies have investigated the effect of Tenure Reform on household NTFP production in Protection Project regions. To fill this gap, we built an integrative conceptual framework and estimated a corresponding structural equation model (SEM using survey data from 932 households in Protection Project regions in southwestern China. In our research framework, there are four factors, including household characteristics, labour and social capital, forestland characteristics, and the Tenure Reform, affecting household NTFP production. The results substantiate that Tenure Reform has had a significant positive effect on household NTFP production. Additionally, household and forestland characteristics have promoted household NTFP production, but quantitatively less than Tenure Reform. This report can be used to inform the government that future investment in Tenure Reform still needs to be enhanced, and policy enforcement still needs to be strengthened.

The top-antitop threshold at the ILC. NNLL QCD uncertainties

Energy Technology Data Exchange (ETDEWEB)

Hoang, Andre H. [Vienna Univ. (Austria). Faculty of Physics; Stahlhofen, Maximilian [DESY Hamburg (Germany). Theory Group

2013-09-15

We study combined variations of the renormalization and matching scales in order to reliably estimate the perturbative error of the latest NNLL vNRQCD prediction for top-antitop threshold production at a future linear collider. We present results for the total cross section and for the experimentally more relevant case, when moderate cuts are imposed on the reconstructed top and antitop invariant masses.

The top-antitop threshold at the ILC. NNLL QCD uncertainties

International Nuclear Information System (INIS)

Hoang, Andre H.; Stahlhofen, Maximilian

2013-09-01

We study combined variations of the renormalization and matching scales in order to reliably estimate the perturbative error of the latest NNLL vNRQCD prediction for top-antitop threshold production at a future linear collider. We present results for the total cross section and for the experimentally more relevant case, when moderate cuts are imposed on the reconstructed top and antitop invariant masses.

FACTORS INFLUENCING PURCHASING DECISIONS FOR TRADITIONAL AND REGIONAL PRODUCTS AMONG RESIDENTS OF THE PODKARPACIE VOIVODESHIP

Directory of Open Access Journals (Sweden)

Marta Kawa

2014-09-01

Full Text Available The paper presents the factors determining the choice of traditional and regional products by Podkarpacie residents. The surveyed consumers found the quality as the most important trait that encourages the purchase of traditional and regional products. The price has an important impact on decision in terms of purchase.

Compilation and testing of tools and methods for sustainable coastal management at local and regional scales : Deliverable D2.5.4, Thresholds project, 6th framework programme, EU, 108 p.

OpenAIRE

Håkanson, Lars

2008-01-01

This work describes how general methods and models for sustainable coastal ecosystem management at local to regional scales may be used to address key questions in coastal management and threshold science. The general, process-based mass-balance model (CoastMab) for substances transported to, within and from for coastal areas may be used as a tool to: 1. Combat eutrophication, 2. Rank nutrient fluxes, 3. Estimate the system response related to nutrient reductions and 4. Estimate realistic val...

Summary of DOE threshold limits efforts

International Nuclear Information System (INIS)

Wickham, L.E.; Smith, C.F.; Cohen, J.J.

1987-01-01

The Department of Energy (DOE) has been developing the concept of threshold quantities for use in determining which waste materials may be disposed of as nonradioactive waste in DOE sanitary landfills. Waste above a threshold level could be managed as radioactive or mixed waste (if hazardous chemicals are present); waste below this level would be handled as sanitary waste. After extensive review of a draft threshold guidance document in 1985, a second draft threshold background document was produced in March 1986. The second draft included a preliminary cost-benefit analysis and quality assurance considerations. The review of the second draft has been completed. Final changes to be incorporated include an in-depth cost-benefit analysis of two example sites and recommendations of how to further pursue (i.e. employ) the concept of threshold quantities within the DOE. 3 references

Genetic variation in threshold reaction norms for alternative reproductive tactics in male Atlantic salmon, Salmo salar.

Science.gov (United States)

Piché, Jacinthe; Hutchings, Jeffrey A; Blanchard, Wade

2008-07-07

Alternative reproductive tactics may be a product of adaptive phenotypic plasticity, such that discontinuous variation in life history depends on both the genotype and the environment. Phenotypes that fall below a genetically determined threshold adopt one tactic, while those exceeding the threshold adopt the alternative tactic. We report evidence of genetic variability in maturation thresholds for male Atlantic salmon (Salmo salar) that mature either as large (more than 1 kg) anadromous males or as small (10-150 g) parr. Using a common-garden experimental protocol, we find that the growth rate at which the sneaker parr phenotype is expressed differs among pure- and mixed-population crosses. Maturation thresholds of hybrids were intermediate to those of pure crosses, consistent with the hypothesis that the life-history switch points are heritable. Our work provides evidence, for a vertebrate, that thresholds for alternative reproductive tactics differ genetically among populations and can be modelled as discontinuous reaction norms for age and size at maturity.

The influence of loading frequency on near-threshold fatigue crack growth

International Nuclear Information System (INIS)

Ogawa, Takeshi; Tokaji, Keiro; Ochi, Satoshi

1986-01-01

Fatigue crack growth and crack closure in the near-threshold region were investigated under different loading frequencies for three types of steel. The results show that the loading frequency influences the near-threshold characteristics in fatigue crack growth, through the different contributions of the fretting oxide induced crack closure. This behaviour is attributed to condensation of moisture between crack faces, which is influenced by the loading frequency. The formation of the fretting oxide debris promoted by the condensation of moisture becomes marked at a higher frequency. However, it is an unstable and complicating phenomenon, since the condensation is also influenced by relative humidity, test temperature and sheet thickness. Therefore, it is concluded that non-oxide controlled crack growth characteristics should be used for the life prediction of structures. (author)

Usage of fMRI for pre-surgical planning in brain tumor and vascular lesion patients: Task and statistical threshold effects on language lateralization

Directory of Open Access Journals (Sweden)

Tanvi N. Nadkarni

2015-01-01

Conclusion: Our results suggest that the type of task and the applied statistical threshold influence LI and that the threshold effects on LI may be task-specific. Thus identifying critical functional regions and computing LIs should be conducted on an individual subject basis, using a continuum of threshold values with different tasks to provide the most accurate information for surgical planning to minimize post-operative language deficits.

Effects of alcohol and noise on temporary threshold shift in Guinea pigs.

Science.gov (United States)

Liu, Tien-Chen; Hsu, Chuan-Jen; Hwang, Juen-Haur; Tseng, Fen-Yu; Chen, Yuh-Shyang

2004-01-01

The purpose of this study was to investigate the effects of concomitant exposure to noise and alcohol on the auditory thresholds. Twenty-four guinea pigs were equally divided into three groups: the acute intoxication group, the chronic intoxication group and the control group. Animals in the acute group received single intraperitoneal injections of ethanol (2 g/kg). In the chronic group, alcohol was administered via drinking water (10%, v/v) over a 60-day period. All animals were exposed to a white noise at the intensity of 105 dB A for 30 min. Auditory brainstem response (ABR) thresholds and distortion product otoacoustic emission (DPOAE) levels were measured before, immediately after noise exposure and also 1, 2, and 7 days following exposure. The results showed: first, acute alcohol injection caused a significant, temporary elevation of ABR threshold (4.8 dB in average), while chronic alcohol treatment did not change auditory threshold significantly. Second, noise exposure induced a mean threshold shift of 15.4- 19.7 dB. ABR threshold returned to normal 2 days after exposure. Both acute and chronic alcohol treatment did not alter the magnitude and time course of recovery of the temporary threshold shift (TTS). Third, the mean DPOAE amplitudes decreased at most frequencies following acute injection of alcohol. However, the differences did not reach statistical significance. Fourth, the mean DPOAE levels dropped 3.4-9.6 dB in all groups after noise exposure and returned to normal 1 day to 2 days after noise. There were no significant differences in the amount of DPOAE suppression after noise between the three groups. In summary, we have found that acute and chronic treatment of alcohol in combination with noise did not significantly exacerbate TTS or decrease DPOAE amplitudes relative to noise exposure alone. Copyright 2004 S. Karger AG, Basel

Determinants of regional labour productivity growth: A study for the hospitality sector in Spain

Directory of Open Access Journals (Sweden)

Bienvenido Ortega Aguaza

2013-01-01

Full Text Available The aim of this paper is to analyze the determinants of labour productivity growth in the hospitality industry in Spain using regional data over the period 1996-2004. The results obtained suggest that the increase in the number of 3-star hotels and the reduction process in the stock of physical capital per worker are factors which may have contributed to the fall in productivity growth. However, increased regional tourism intensity has a positive impact on the growth of labour productivity. Nonetheless, changes in demand-related factors, such as average length of stay and the seasonality of demand, have not had a significant aggregate impact on labour productivity growth during this period.

First observation of top quark production in the forward region.

Science.gov (United States)

Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Anderson, J; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; d'Argent, P; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Bel, L J; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bertolin, A; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Birnkraut, A; Bizzeti, A; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Braun, S; Brett, D; Britsch, M; Britton, T; Brodzicka, J; Brook, N H; Bursche, A; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Campana, P; Campora Perez, D; Capriotti, L; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carniti, P; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cavallero, G; Cenci, R; Charles, M; Charpentier, Ph; Chefdeville, M; Chen, S; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collazuol, G; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Corvo, M; Couturier, B; Cowan, G A; Craik, D C; Crocombe, A; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Dean, C-T; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Demmer, M; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Di Ruscio, F; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dreimanis, K; Dufour, L; Dujany, G; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Ely, S; Esen, S; Evans, H M; Evans, T; Falabella, A; Färber, C; Farinelli, C; Farley, N; Farry, S; Fay, R; Ferguson, D; Fernandez Albor, V; Ferrari, F; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fohl, K; Fol, P; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Fu, J; Furfaro, E; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; García Pardiñas, J; Garofoli, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gastaldi, U; Gauld, R; Gavardi, L; Gazzoni, G; Geraci, A; Gerick, D; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Gianì, S; Gibson, V; Girard, O G; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graverini, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadavizadeh, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Henry, L; Hernando Morata, J A; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Humair, T; Hussain, N; Hutchcroft, D; Hynds, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Karodia, S; Kelsey, M; Kenyon, I R; Kenzie, M; Ketel, T; Khanji, B; Khurewathanakul, C; Klaver, S; Klimaszewski, K; Kochebina, O; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozeiha, M; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kuonen, A K; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanfranchi, G; Langenbruch, C; Langhans, B; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Likhomanenko, T; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Liu, X; Loh, D; Lohn, S; Longstaff, I; Lopes, J H; Lucchesi, D; Lucio Martinez, M; Luo, H; Lupato, A; Luppi, E; Lupton, O; Machefert, F; Maciuc, F; Maev, O; Maguire, K; Malde, S; Malinin, A; Manca, G; Mancinelli, G; Manning, P; Mapelli, A; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marino, P; Märki, R; Marks, J; Martellotti, G; Martin, M; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massafferri, A; Matev, R; Mathad, A; Mathe, Z; Matteuzzi, C; Matthieu, K; Mauri, A; Maurin, B; Mazurov, A; McCann, M; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Melnychuk, D; Merk, M; Milanes, D A; Minard, M-N; Mitzel, D S; Molina Rodriguez, J; Monteil, S; Morandin, M; Morawski, P; Mordà, A; Morello, M J; Moron, J; Morris, A B; Mountain, R; Muheim, F; Müller, J; Müller, K; Müller, V; Mussini, M; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nandi, A; Nasteva, I; Needham, M; Neri, N; Neubert, S; Neufeld, N; Neuner, M; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Ninci, D; Novoselov, A; O'Hanlon, D P; Oblakowska-Mucha, A; Obraztsov, V; Ogilvy, S; Okhrimenko, O; Oldeman, R; Onderwater, C J G; Osorio Rodrigues, B; Otalora Goicochea, J M; Otto, A; Owen, P; Oyanguren, A; Palano, A; Palombo, F; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Pappalardo, L L; Pappenheimer, C; Parkes, C; Passaleva, G; Patel, G D; Patel, M; Patrignani, C; Pearce, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perret, P; Pescatore, L; Petridis, K; Petrolini, A; Petruzzo, M; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Pistone, A; Piucci, A; Playfer, S; Plo Casasus, M; Poikela, T; Polci, F; Poluektov, A; Polyakov, I; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Price, E; Price, J D; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Quagliani, R; Rachwal, B; Rademacker, J H; Rakotomiaramanana, B; Rama, M; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redi, F; Reichert, S; Reid, M M; Dos Reis, A C; Ricciardi, S; Richards, S; Rihl, M; Rinnert, K; Rives Molina, V; Robbe, P; Rodrigues, A B; Rodrigues, E; Rodriguez Lopez, J A; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Ronayne, J W; Rotondo, M; Rouvinet, J; Ruf, T; Ruiz, H; Ruiz Valls, P; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Sanchez Mayordomo, C; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santimaria, M; Santovetti, E; Sarti, A; Satriano, C; Satta, A; Saunders, D M; Savrina, D; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmelzer, T; Schmidt, B; Schneider, O; Schopper, A; Schubiger, M; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Semennikov, A; Sepp, I; Serra, N; Serrano, J; Sestini, L; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, V; Shires, A; Silva Coutinho, R; Simi, G; Sirendi, M; Skidmore, N; Skillicorn, I; Skwarnicki, T; Smith, E; Smith, E; Smith, I T; Smith, J; Smith, M; Snoek, H; Sokoloff, M D; Soler, F J P; Souza, D; Souza De Paula, B; Spaan, B; Spradlin, P; Sridharan, S; Stagni, F; Stahl, M; Stahl, S; Steinkamp, O; Stenyakin, O; Sterpka, F; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Stracka, S; Straticiuc, M; Straumann, U; Sun, L; Sutcliffe, W; Swientek, K; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Tekampe, T; Teklishyn, M; Tellarini, G; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Todd, J; Tolk, S; Tomassetti, L; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Trabelsi, K; Tran, M T; Tresch, M; Trisovic, A; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ukleja, A; Ustyuzhanin, A; Uwer, U; Vacca, C; Vagnoni, V; Valenti, G; Vallier, A; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vieites Diaz, M; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; de Vries, J A; Waldi, R; Wallace, C; Wallace, R; Walsh, J; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Websdale, D; Weiden, A; Whitehead, M; Wiedner, D; Wilkinson, G; Wilkinson, M; Williams, M; Williams, M P; Williams, M; Williams, T; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wright, S; Wyllie, K; Xie, Y; Xu, Z; Yang, Z; Yu, J; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, L; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L

2015-09-11

Top quark production in the forward region in proton-proton collisions is observed for the first time. The W+b final state with W→μν is reconstructed using muons with a transverse momentum, p_{T}, larger than 25 GeV in the pseudorapidity range 2.020  GeV. The results are based on data corresponding to integrated luminosities of 1.0 and 2.0  fb^{-1} collected at center-of-mass energies of 7 and 8 TeV by LHCb. The inclusive top quark production cross sections in the fiducial region are σ(top)[7  TeV]=239±53(stat)±33(syst)±24(theory)  fb,σ(top)[8  TeV]=289±43(stat)±40(syst)±29(theory)  fb.These results, along with the observed differential yields and charge asymmetries, are in agreement with next-to-leading order standard model predictions.

Economic evaluation and cost-effectiveness thresholds: signals to firms and implications for R & D investment and innovation.

Science.gov (United States)

Vernon, John A; Goldberg, Robert; Golec, Joseph

2009-01-01

In this article we describe how reimbursement cost-effectiveness thresholds, per unit of health benefit, whether set explicitly or observed implicitly via historical reimbursement decisions, serve as a signal to firms about the commercial viability of their R&D projects (including candidate products for in-licensing). Traditional finance methods for R&D project valuations, such as net present value analyses (NPV), incorporate information from these payer reimbursement signals to help determine which R&D projects should be continued and which should be terminated (in the case of the latter because they yield an NPV important for reimbursement thresholds to reflect the economic value of the unit of health benefit being considered for reimbursement. Thresholds set too low (below the economic value of the health benefit) will result in R&D investment levels that are too low relative to the economic value of R&D (on the margin). Similarly, thresholds set too high (above the economic value of the health benefit) will result in inefficiently high levels of R&D spending. The US in particular, which represents approximately half of the global pharmaceutical market (based on sales), and which seems poised to begin undertaking cost effectiveness in a systematic way, needs to exert caution in setting policies that explicitly or implicitly establish cost-effectiveness reimbursement thresholds for healthcare products and technologies, such as pharmaceuticals.

Effect of threshold quantization in opportunistic splitting algorithm

KAUST Repository

Nam, Haewoon

2011-12-01

This paper discusses algorithms to find the optimal threshold and also investigates the impact of threshold quantization on the scheduling outage performance of the opportunistic splitting scheduling algorithm. Since this algorithm aims at finding the user with the highest channel quality within the minimal number of mini-slots by adjusting the threshold every mini-slot, optimizing the threshold is of paramount importance. Hence, in this paper we first discuss how to compute the optimal threshold along with two tight approximations for the optimal threshold. Closed-form expressions are provided for those approximations for simple calculations. Then, we consider linear quantization of the threshold to take the limited number of bits for signaling messages in practical systems into consideration. Due to the limited granularity for the quantized threshold value, an irreducible scheduling outage floor is observed. The numerical results show that the two approximations offer lower scheduling outage probability floors compared to the conventional algorithm when the threshold is quantized. © 2006 IEEE.

Regional Markets for Non-timber Forest Products in Eastern Brazilian Amazon

OpenAIRE

Vuola, Matleena

2013-01-01

While export of non-timber forest products (NTFPs) has been promoted as a sustainable development strategy, the literature suggests that local and regional markets are also potentially important, not only for producers but also for traders and consumers (Shackleton et al. 2007). For producers, regional markets are thought to offer more accessible and more stable markets, while for traders, these markets offer employment, and for consumers, reasonably priced, diverse, fresh food. Consumptio...

Human food chain contamination. Dairy products in 28 regions of the E.E.C. in 1977

International Nuclear Information System (INIS)

Obino, A.-M.; Garnier, Arlette; Brenot, Jean.

1981-08-01

Global and individual levels of contamination by cesium 137 and strontium 90 resulting from consumption of dairy products in 28 regions of the European Economical Community are evaluated. We begin with economical considerations: production, industry, distribution and consumption. Regional exchanges, using 1977 statistical data, are then established for the following products: crude milk, skim milk, consumption milk, fresh products, butter, cheese and powder. Finally, various contamination results are presented, associated with the observed concentrations of cesium 137 and strontium 90 in milk in the E.E.C. during 1977, and in the hypothesis of highly contaminated regions. Some results are expressed as concentrations in the various dairy products after transformations and exchanges, others are expressed as individual ingested activities. A sensitivity analysis is used to assess the exchange effect [fr

Online Time Series Analysis of Land Products over Asia Monsoon Region via Giovanni

Science.gov (United States)

Shen, Suhung; Leptoukh, Gregory G.; Gerasimov, Irina

2011-01-01

Time series analysis is critical to the study of land cover/land use changes and climate. Time series studies at local-to-regional scales require higher spatial resolution, such as 1km or less, data. MODIS land products of 250m to 1km resolution enable such studies. However, such MODIS land data files are distributed in 10ox10o tiles, due to large data volumes. Conducting a time series study requires downloading all tiles that include the study area for the time period of interest, and mosaicking the tiles spatially. This can be an extremely time-consuming process. In support of the Monsoon Asia Integrated Regional Study (MAIRS) program, NASA GES DISC (Goddard Earth Sciences Data and Information Services Center) has processed MODIS land products at 1 km resolution over the Asia monsoon region (0o-60oN, 60o-150oE) with a common data structure and format. The processed data have been integrated into the Giovanni system (Goddard Interactive Online Visualization ANd aNalysis Infrastructure) that enables users to explore, analyze, and download data over an area and time period of interest easily. Currently, the following regional MODIS land products are available in Giovanni: 8-day 1km land surface temperature and active fire, monthly 1km vegetation index, and yearly 0.05o, 500m land cover types. More data will be added in the near future. By combining atmospheric and oceanic data products in the Giovanni system, it is possible to do further analyses of environmental and climate changes associated with the land, ocean, and atmosphere. This presentation demonstrates exploring land products in the Giovanni system with sample case scenarios.

Groundwater decline and tree change in floodplain landscapes: Identifying non-linear threshold responses in canopy condition

Directory of Open Access Journals (Sweden)

J. Kath

2014-12-01

Full Text Available Groundwater decline is widespread, yet its implications for natural systems are poorly understood. Previous research has revealed links between groundwater depth and tree condition; however, critical thresholds which might indicate ecological ‘tipping points’ associated with rapid and potentially irreversible change have been difficult to quantify. This study collated data for two dominant floodplain species, Eucalyptus camaldulensis (river red gum and E. populnea (poplar box from 118 sites in eastern Australia where significant groundwater decline has occurred. Boosted regression trees, quantile regression and Threshold Indicator Taxa Analysis were used to investigate the relationship between tree condition and groundwater depth. Distinct non-linear responses were found, with groundwater depth thresholds identified in the range from 12.1 m to 22.6 m for E. camaldulensis and 12.6 m to 26.6 m for E. populnea beyond which canopy condition declined abruptly. Non-linear threshold responses in canopy condition in these species may be linked to rooting depth, with chronic groundwater decline decoupling trees from deep soil moisture resources. The quantification of groundwater depth thresholds is likely to be critical for management aimed at conserving groundwater dependent biodiversity. Identifying thresholds will be important in regions where water extraction and drying climates may contribute to further groundwater decline. Keywords: Canopy condition, Dieback, Drought, Tipping point, Ecological threshold, Groundwater dependent ecosystems

GLOBAL AND REGIONAL GEOCHEMICAL INDEXES OF PRODUCTION OF CHEMICAL ELEMENTS

Directory of Open Access Journals (Sweden)

Nikolay S. Kasimov

2014-01-01

Full Text Available This paper presents a geochemical assessment of the primary involvement of chemical elements in technogenesis in the world and individual countries. In order to compare the intensity of production of various chemical elements in different countries, the authors have introduced a number of new terms and parameters. The new term is “abstract rock” (AR - an elemental equivalent, whose average composition corresponds to the average chemical composition of the upper continental crust. The new parameters are: “conditional technophility of an element” (TY, “specific technophility” (TYN “regional conditional technophility” (TYR, “specific regional technophility” (TN, and “density of regional conditional technophility” (TS. TY equals to the tons of AR per year necessary for the production of the current level of the element. TY of different elements has been estimated for 2008-2010. The highest TY values are associated with C, S, N, Ra, and Au. TY of many micro- and ultramicroelements is of the order of n•1011t. TYN reflects the volume of AR per the world’s capita. TYN changes from the 1960s to 2010 indicates that the Earth’s population is growing much faster than its demand for many chemical elements. TYR, TN, and TS were used for the integrated assessment of technogenesis at the regional scale; they reflect the intensity of the technogenesis process at the level of individual countries and allow comparing countries with different levels of elements production, population, and areas. The TN and TS levels of the leaders in extraction of natural resources are below these values in other countries due to the large territories (Russia, USA, Canada, Australia, Saudi Arabia, Kazakhstan, Argentina, Bolivia, Venezuela, Colombia, Zambia, Mali, Libya, Mongolia, and Sudan, to the large population (Indonesia, Vietnam, the Philippines, Bangladesh, Nigeria, or to both high spatial and demographic dimensions (India, Brazil, France, Egypt

The asymmetry of the impact of oil price shocks on economic activities: an application of the multivariate threshold model

International Nuclear Information System (INIS)

Bwo-Nung Huang; National Chia-Yi University; Hwang, M.J.; Hsiao-Ping Peng

2005-01-01

This paper applies the multivariate threshold model to investigate the impacts of an oil price change and its volatility on economic activities (changes in industrial production and real stock returns). The statistical test on the existence of a threshold effect indicates that a threshold value does exist. Using monthly data of the US, Canada, and Japan during the period from 1970 to 2002, we conclude: (i) the optimal threshold level seems to vary according to how an economy depends on imported oil and the attitude towards adopting energy-saving technology; (ii) an oil price change or its volatility has a limited impact on the economies if the change is below the threshold levels; (iii) if the change is above threshold levels, it appears that the change in oil price better explains macroeconomic variables than the volatility of the oil price; and (iv) if the change is above threshold levels, a change in oil price or its volatility explains the model better than the real interest rate. (author)

Multi-Regional Input-Output (MRIO Study of the Provincial Ecological Footprints and Domestic Embodied Footprints Traded among China’s 30 Provinces

Directory of Open Access Journals (Sweden)

Decun Wu

2016-12-01

Full Text Available Rapid development in China has led to imbalances and inequities of ecological resources among the provinces and regions. In this study, an environmentally extended multi-regional input-output (MRIO model was used to analyze the imbalances, inequities and pressures of the ecological footprints (EF of China’s 30 provinces in 2007. In addition, by decomposing the total product consumption coefficients, we calculated the net embodied EF of the flows among the provinces by the total amount, land type and sector. The results showed that most provinces presented EF deficits. Significant differences were observed between the ecological pressure in consumption (EPC and ecological pressure in production (EPP for each province because of the net embodied EF trade; the EPCs of Shanghai (15.16, Beijing (7.81 and Tianjin (7.81 were the largest and presented descending EPPs, whereas the EPCs of Heilongjiang (0.98, Hebei (0.98, Xinjiang (0.98 and Guangxi (0.98 were under the threshold value (1 and presented ascending EPPs. The carbon footprint in the secondary sector was the main embodied EF of the flows among the provinces responsible for inequities. Finally, based on the various conditions of the provinces in different geographical regions, we have provided suggestions for regionally balanced development that can maintain the EPP and EPC values under the threshold for each province.

Assessing the impact of urbanization on regional net primary productivity in Jiangyin County, China.

Science.gov (United States)

Xu, C; Liu, M; An, S; Chen, J M; Yan, P

2007-11-01

Urbanization is one of the most important aspects of global change. The process of urbanization has a significant impact on the terrestrial ecosystem carbon cycle. The Yangtze Delta region has one of the highest rates of urbanization in China. In this study, carried out in Jiangyin County as a representative region within the Yangtze Delta, land use and land cover changes were estimated using Landsat TM and ETM+ imagery. With these satellite data and the BEPS process model (Boreal Ecosystem Productivity Simulator), the impacts of urbanization on regional net primary productivity (NPP) and annual net primary production were assessed for 1991 and 2002. Landsat-based land cover maps in 1991 and 2002 showed that urban development encroached large areas of cropland and forest. Expansion of residential areas and reduction of vegetated areas were the major forms of land transformation in Jiangyin County during this period. Mean NPP of the total area decreased from 818 to 699 gCm(-2)yr(-1) during the period of 1991 to 2002. NPP of cropland was only reduced by 2.7% while forest NPP was reduced by 9.3%. Regional annual primary production decreased from 808 GgC in 1991 to 691 GgC in 2002, a reduction of 14.5%. Land cover changes reduced regional NPP directly, and the increasing intensity and frequency of human-induced disturbance in the urbanized areas could be the main reason for the decrease in forest NPP.

Log canonical thresholds of smooth Fano threefolds

International Nuclear Information System (INIS)

Cheltsov, Ivan A; Shramov, Konstantin A

2008-01-01

The complex singularity exponent is a local invariant of a holomorphic function determined by the integrability of fractional powers of the function. The log canonical thresholds of effective Q-divisors on normal algebraic varieties are algebraic counterparts of complex singularity exponents. For a Fano variety, these invariants have global analogues. In the former case, it is the so-called α-invariant of Tian; in the latter case, it is the global log canonical threshold of the Fano variety, which is the infimum of log canonical thresholds of all effective Q-divisors numerically equivalent to the anticanonical divisor. An appendix to this paper contains a proof that the global log canonical threshold of a smooth Fano variety coincides with its α-invariant of Tian. The purpose of the paper is to compute the global log canonical thresholds of smooth Fano threefolds (altogether, there are 105 deformation families of such threefolds). The global log canonical thresholds are computed for every smooth threefold in 64 deformation families, and the global log canonical thresholds are computed for a general threefold in 20 deformation families. Some bounds for the global log canonical thresholds are computed for 14 deformation families. Appendix A is due to J.-P. Demailly.

Application of biogas for combined heat and power production in the rural region

International Nuclear Information System (INIS)

Kozak, T.; Majchrzycka, A.

2009-01-01

The paper discusses combined production of heat and power (CHP) from biogas in a small-scale power plant placed in the rural region. Based on power and heat demands of the rural region and biomass supply, the CHP system was selected. Keywords: biogas, cogeneration

Soil Response to Global Change: Soil Process Domains and Pedogenic Thresholds (Invited)

Science.gov (United States)

Chadwick, O.; Kramer, M. G.; Chorover, J.

2013-12-01

The capacity of soil to withstand perturbations, whether driven by climate, land use change, or spread of invasive species, depends on its chemical composition and physical state. The dynamic interplay between stable, well buffered soil process domains and thresholds in soil state and function is a strong determinant of soil response to forcing from global change. In terrestrial ecosystems, edaphic responses are often mediated by availability of water and its flux into and through soils. Water influences soil processes in several ways: it supports biological production, hence proton-donor, electron-donor and complexing-ligand production; it determines the advective removal of dissolution products, and it can promote anoxia that leads microorganisms to utilize alternative electron acceptors. As a consequence climate patterns strongly influence global distribution of soil, although within region variability is governed by other factors such as landscape age, parent material and human land use. By contrast, soil properties can vary greatly among climate regions, variation which is guided by the functioning of a suite of chemical processes that tend to maintain chemical status quo. This soil 'buffering' involves acid-base reactions as minerals weather and oxidation-reduction reactions that are driven by microbial respiration. At the planetary scale, soil pH provides a reasonable indicator of process domains and varies from about 3.5 to10, globally, although most soils lie between about 4.5 and 8.5. Those that are above 7.5 are strongly buffered by the carbonate system, those that are characterized by neutral pH (7.5-6) are buffered by release of non-hydrolyzing cations from primary minerals and colloid surfaces, and those that are buffered by hydrolytic aluminum on colloidal surfaces. Alkali and alkaline (with the exception of limestone parent material) soils are usually associated with arid and semiarid conditions, neutral pH soils with young soils in both dry and wet

An Assessment of Regional Sustainability through Quality Labels for Small Farmers’ Products: A Slovak Case Study

Directory of Open Access Journals (Sweden)

Jana Jaďuďová

2018-04-01

Full Text Available Regional product labelling can help develop regional business activities, especially with traditional regional products. Their general popularity is a significant source of income for less-developed regions. The Gemer-Malohont region is an economically underdeveloped area with a high unemployment rate. The subject of the survey was focused on regional food products that are made by small farmers. The analysis was carried out using data from a questionnaire survey on the period April–July 2017 in each of the region’s districts. The results obtained by the questionnaire survey were processed with the use of statistical methods (two-step cluster analysis, radar chart, box-plots, regression analysis using Microsoft Excel and the IBM SPSS Statistics 23 software. We divided consumers into two groups—knowledgeable regional food purchasers and priced-oriented consumers—based on their preference for regional food and through cluster analysis. We show that the more developed regions (Rimavská Sobota and Rožňava show a higher rate of purchase of regional foods. Less-developed regions (Poltár, Revúca are represented by lower-income consumers for whom the food price is the decisive criterion. Local residents of backward regions should pay attention to domestic food and local small farmers who are tools for the creation of local capital and local development.

Thresholds of sea-level rise rate and sea-level acceleration rate in a vulnerable coastal wetland

Science.gov (United States)

Wu, W.; Biber, P.; Bethel, M.

2017-12-01

Feedback among inundation, sediment trapping, and vegetation productivity help maintain coastal wetlands facing sea-level rise (SLR). However, when the SLR rate exceeds a threshold, coastal wetlands can collapse. Understanding the threshold help address the key challenge in ecology - nonlinear response of ecosystems to environmental change, and promote communication between ecologists and policy makers. We studied the threshold of SLR rate and developed a new threshold of SLR acceleration rate on sustainability of coastal wetlands as SLR is likely to accelerate due to the enhanced anthropogenic forces. We developed a mechanistic model to simulate wetland change and derived the SLR thresholds for Grand Bay, MS, a micro-tidal estuary with limited upland freshwater and sediment input in the northern Gulf of Mexico. The new SLR acceleration rate threshold complements the threshold of SLR rate and can help explain the temporal lag before the rapid decline of wetland area becomes evident after the SLR rate threshold is exceeded. Deriving these two thresholds depends on the temporal scale, the interaction of SLR with other environmental factors, and landscape metrics, which have not been fully accounted for before this study. The derived SLR rate thresholds range from 7.3 mm/yr to 11.9 mm/yr. The thresholds of SLR acceleration rate are 3.02×10-4 m/yr2 and 9.62×10-5 m/yr2 for 2050 and 2100 respectively. Based on the thresholds developed, predicted SLR that will adversely impact the coastal wetlands in Grand Bay by 2100 will fall within the likely range of SLR under a high warming scenario (RCP8.5), and beyond the very likely range under a low warming scenario (RCP2.6 or 3), highlighting the need to avoid the high warming scenario in the future if these marshes are to be preserved.

Regional-Scale Climate Change: Observations and Model Simulations

Energy Technology Data Exchange (ETDEWEB)

Bradley, Raymond S; Diaz, Henry F

2010-12-14

This collaborative proposal addressed key issues in understanding the Earth's climate system, as highlighted by the U.S. Climate Science Program. The research focused on documenting past climatic changes and on assessing future climatic changes based on suites of global and regional climate models. Geographically, our emphasis was on the mountainous regions of the world, with a particular focus on the Neotropics of Central America and the Hawaiian Islands. Mountain regions are zones where large variations in ecosystems occur due to the strong climate zonation forced by the topography. These areas are particularly susceptible to changes in critical ecological thresholds, and we conducted studies of changes in phonological indicators based on various climatic thresholds.

76 FR 14284 - Domestic Shipping Services Product Launch of Parcel Select Regional Ground

Science.gov (United States)

2011-03-16

... POSTAL SERVICE 39 CFR Part 111 Domestic Shipping Services Product Launch of Parcel Select Regional... Standards of the United States Postal Service, Domestic Mail Manual (DMM[supreg]), to introduce a new competitive shipping option, Parcel Select Regional Ground \\TM\\ service. DATES: Effective Date: April 17, 2011...

Threshold Concepts and Information Literacy

Science.gov (United States)

Townsend, Lori; Brunetti, Korey; Hofer, Amy R.

2011-01-01

What do we teach when we teach information literacy in higher education? This paper describes a pedagogical approach to information literacy that helps instructors focus content around transformative learning thresholds. The threshold concept framework holds promise for librarians because it grounds the instructor in the big ideas and underlying…

Evidence for regional nitrogen stress on chlorophyll a in lakes across large landscape and climate gradients

Science.gov (United States)

Filstrup, Christopher T.; Wagner, Tyler; Oliver, Samantha K.; Stow, Craig A.; Webster, Katherine E.; Stanley, Emily H.; Downing, John A.

2018-01-01

Nitrogen (N) and phosphorus (P) commonly stimulate phytoplankton production in lakes, but recent observations from lakes from an agricultural region suggest that nitrate may have a subsidy‐stress effect on chlorophyll a (Chl a). It is unclear, however, how generalizable this effect might be. Here, we analyzed a large water quality dataset of 2385 lakes spanning 60 regions across 17 states in the Northeastern and Midwestern U.S. to determine if N subsidy‐stress effects on phytoplankton are common and to identify regional landscape characteristics promoting N stress effects in lakes. We used a Bayesian hierarchical modeling framework to test our hypothesis that Chl a–total N (TN) threshold relationships would be common across the central agricultural region of the U.S. (“the Corn Belt”), where lake N and P concentrations are high. Data aggregated across all regions indicated that high TN concentrations had a negative effect on Chl a in lakes with concurrent high total P. This large‐scale pattern was driven by relationships within only a subset of regions, however. Eight regions were identified as having Chl a–TN threshold relationships, but only two of these regions located within the Corn Belt clearly demonstrated this subsidy‐stress relationship. N stress effects were not consistent across other intense agricultural regions, as we hypothesized. These findings suggest that interactions among regional land use and land cover, climate, and hydrogeology may be important in determining the synergistic conditions leading to N subsidy‐stress effects on lake phytoplankton.

Optimizing Regional Food and Energy Production under Limited Water Availability through Integrated Modeling

Directory of Open Access Journals (Sweden)

Junlian Gao

2018-05-01

Full Text Available Across the world, human activity is approaching planetary boundaries. In northwest China, in particular, the coal industry and agriculture are competing for key limited inputs of land and water. In this situation, the traditional approach to planning the development of each sector independently fails to deliver sustainable solutions, as solutions made in sectorial ‘silos’ are often suboptimal for the entire economy. We propose a spatially detailed cost-minimizing model for coal and agricultural production in a region under constraints on land and water availability. We apply the model to the case study of Shanxi province, China. We show how such an integrated optimization, which takes maximum advantage of the spatial heterogeneity in resource abundance, could help resolve the conflicts around the water–food–energy (WFE nexus and assist in its management. We quantify the production-possibility frontiers under different water-availability scenarios and demonstrate that in water-scarce regions, like Shanxi, the production capacity and corresponding production solutions are highly sensitive to water constraints. The shadow prices estimated in the model could be the basis for intelligent differentiated water pricing, not only to enable the water-resource transfer between agriculture and the coal industry, and across regions, but also to achieve cost-effective WFE management.

A Threshold Continuum for Aeolian Sand Transport

Science.gov (United States)

Swann, C.; Ewing, R. C.; Sherman, D. J.

2015-12-01

The threshold of motion for aeolian sand transport marks the initial entrainment of sand particles by the force of the wind. This is typically defined and modeled as a singular wind speed for a given grain size and is based on field and laboratory experimental data. However, the definition of threshold varies significantly between these empirical models, largely because the definition is based on visual-observations of initial grain movement. For example, in his seminal experiments, Bagnold defined threshold of motion when he observed that 100% of the bed was in motion. Others have used 50% and lesser values. Differences in threshold models, in turn, result is large errors in predicting the fluxes associated with sand and dust transport. Here we use a wind tunnel and novel sediment trap to capture the fractions of sand in creep, reptation and saltation at Earth and Mars pressures and show that the threshold of motion for aeolian sand transport is best defined as a continuum in which grains progress through stages defined by the proportion of grains in creep and saltation. We propose the use of scale dependent thresholds modeled by distinct probability distribution functions that differentiate the threshold based on micro to macro scale applications. For example, a geologic timescale application corresponds to a threshold when 100% of the bed in motion whereas a sub-second application corresponds to a threshold when a single particle is set in motion. We provide quantitative measurements (number and mode of particle movement) corresponding to visual observations, percent of bed in motion and degrees of transport intermittency for Earth and Mars. Understanding transport as a continuum provides a basis for revaluating sand transport thresholds on Earth, Mars and Titan.

Wavelength dependence of the single pulse femtosecond laser ablation threshold of indium phosphide in the 400-2050 nm range

International Nuclear Information System (INIS)

Borowiec, A.; Tiedje, H.F.; Haugen, H.K.

2005-01-01

We present single pulse femtosecond laser ablation threshold measurements of InP obtained by optical, scanning electron, and atomic force microscopy. The experiments were conducted with laser pulses 65-175 fs in duration, in the wavelength range from 400 to 2050 nm, covering the photon energy region above and below the bandgap of InP. The ablation thresholds determined from depth and volume measurements varied from 87 mJ/cm 2 at 400 nm to 250 mJ/cm 2 at 2050 nm. In addition, crater depths and volumes were measured over a range of laser fluences extending well above the ablation threshold

Evaluating climate variables, indexes and thresholds governing Arctic urban sustainability: case study of Russian permafrost regions

Science.gov (United States)

Anisimov, O. A.; Kokorev, V.

2013-12-01

Addressing Arctic urban sustainability today forces planners to deal with the complex interplay of multiple factors, including governance and economic development, demography and migration, environmental changes and land use, changes in the ecosystems and their services, and climate change. While the latter can be seen as a factor that exacerbates the existing vulnerabilities to other stressors, changes in temperature, precipitation, snow, river and lake ice, and the hydrological regime also have direct implications for the cities in the North. Climate change leads to reduced demand for heating energy, on one hand, and heightened concerns about the fate of the infrastructure built upon thawing permafrost, on the other. Changes in snowfall are particularly important and have direct implications for the urban economy, as together with heating costs, expenses for snow removal from streets, airport runways, roofs and ventilation corridors underneath buildings erected on pile foundations on permafrost constitute the bulk of the city's maintenance budget. Many cities are located in river valleys and are prone to flooding that leads to enormous economic losses and casualties, including human deaths. The severity of the northern climate has direct implications for demographic changes governed by regional migration and labor flows. Climate could thus be viewed as an inexhaustible public resource that creates opportunities for sustainable urban development. Long-term trends show that climate as a resource is becoming more readily available in the Russian North, notwithstanding the general perception that globally climate change is one of the challenges facing humanity in the 21st century. In this study we explore the sustainability of the Arctic urban environment under changing climatic conditions. We identify key governing variables and indexes and study the thresholds beyond which changes in the governing climatic parameters have significant impact on the economy

Iran: the next nuclear threshold state?

OpenAIRE

Maurer, Christopher L.

2014-01-01

Approved for public release; distribution is unlimited A nuclear threshold state is one that could quickly operationalize its peaceful nuclear program into one capable of producing a nuclear weapon. This thesis compares two known threshold states, Japan and Brazil, with Iran to determine if the Islamic Republic could also be labeled a threshold state. Furthermore, it highlights the implications such a status could have on U.S. nonproliferation policy. Although Iran's nuclear program is mir...

Study of mode locking in a microwave-pumped diode laser close to the generation threshold

International Nuclear Information System (INIS)

Bagaev, Sergei N; Zakharyash, Valerii F; Kashirsky, Aleksandr V; Klementyev, Vasilii M; Kuznetsov, Sergei A; Pivtsov, V S

2004-01-01

Active mode locking is studied in a diode laser with a three-mirror resonator upon the microwave modulation of the pump current. The mode-locking region with the minimal width of the spectrum of intermode beats is found, when the microwave frequency is close to the intermode frequency of an external resonator. This region is shown to be located close to the threshold pump current. (lasers, active media)

Determination of the {eta} mass from the production threshold for the {gamma}p {yields} p{eta} reaction

Energy Technology Data Exchange (ETDEWEB)

Nikolaev, Alexander

2012-09-06

This thesis is dedicated to a new precise determination of the {eta} meson mass based on a measurement of the threshold for the {gamma}p {yields} p{eta} reaction. This experiment was performed in the years 2004/2005 using the Crystal Ball/TAPS detector setup and the recently developed tagger focal-plane microscope detector at the MAMI-B facility in the Institut fuer Kernphysik of the Johannes Gutenberg-Universitaet Mainz. The real photon beam was produced by Bremsstrahlung of the 883 MeV electrons from MAMI-B on a thin diamond radiator. The {eta} mesons were identified via their two main decay modes, {eta} {yields} 2{gamma} and {eta} {yields} 3{pi}{sup 0}, with the Crystal Ball/TAPS setup, which measured energies and emission angles of particles. The identification of the {eta} {yields} 2{gamma} decay was performed using events with two clusters detected as photons, ignoring all other particles, and the standard invariant mass analysis. Cuts were applied on the invariant and missing mass distributions. The identification of the {eta} {yields} 3{pi}{sup 0} {yields} 6{gamma} decay concentrated on events with six clusters detected as photons. Among fifteen possible combinations of six photons to be arranged in three pairs, the combination with the smallest {chi}{sup 2}-value for the three pion masses was assumed to be correct. Cuts were applied on the {chi}{sup 2}-distribution and on the invariant and missing mass distributions. The normalization of the total cross section was obtained from the target thickness, the intensity of the photon flux, the simulated acceptance of the Crystal Ball, and the branching ratios of the {eta} decays. The determination of the {eta} mass required a very precise measurement of the production threshold. This was obtained by fitting the measured cross section as a function of photon energy and gave the result for the {eta} mass, m{sub {eta}}=(547.851{+-}0.031{sub stat.}{+-}0.062{sub syst.}) MeV.

Diversity of Rainfall Thresholds for early warning of hydro-geological disasters

Directory of Open Access Journals (Sweden)

D. L. De Luca

2017-06-01

Full Text Available For early warning of disasters induced by precipitation (such as floods and landslides, different kinds of rainfall thresholds are adopted, which vary from each other, on the basis on adopted hypotheses. In some cases, they represent the occurrence probability of an event (landslide or flood, in other cases the exceedance probability of a critical value for an assigned indicator I (a function of rainfall heights, and in further cases they only indicate the exceeding of a prefixed percentage a critical value for I, indicated as Icr. For each scheme, it is usual to define three different criticality levels (ordinary, moderate and severe, which are associated to warning levels, according to emergency plans. This work briefly discusses different schemes of rainfall thresholds, focusing attention on landslide prediction, with some applications to a real case study in Calabria region (southern Italy.

Cost of paricá wood production in Paragominas region, Para State, Brazil

Directory of Open Access Journals (Sweden)

Rafaela da Silveira

2017-12-01

Full Text Available The silvicultural and economic potential of paricá (Schizolobium amazonicum has encouraged the expansion of this crop, mainly in the northern region of the country, provoking the need for studies on the species. The objective of this study was to estimate paricá production in Paragominas region, Para State, Brazil, at 5, 6 and 7 years, in three classes of productivity considering five plant arrangements, being identified the main costs of production, in addition to those most affected by plant arrangements. The volumetric estimation was obtained by modeling in population level and the analysis of the costs, through the methodology of the operational cost. It was possible to infer that the arrangement of plants 3 m x 2 m was superior in volume, compared to the other analyzed plant arrangements. The effective operating cost represented on average 65% of the total production costs. Transport was the most significant individual cost, in all analyzed plant arrangements. The maintenance, among the set of activities, was the most significant in planting, fact that may be related to the number and the long period for the activities execution. Smaller plant arrangements presented the higher total costs of production, depending or not on the remuneration for the use of the permanent and current capital.

Natural radionuclides concentration in agricultural products and water from the Monte Alegre region

International Nuclear Information System (INIS)

Gouvea, Vandir A.; Melo, Vicente P.; Binns, Donald A.C.; Santos, Pedro L. dos

1997-01-01

Measurements to determine the content of natural radionuclides were performed in agricultural products in the brazilian Central Amazon Basin Monte Alegre region, for the soil-plant transfer calculation. these measurements were concentrated in the Ingles de Souza agricultural settlement, were several uranium and thorium occurrences exist in geological formations called Monte Alegre and Faro. The values obtained in foodstuff cultivated in the anomalous region are 10 times higher than those ones observed in the Alenquer region, which is the chosen region due to its low level natural radioactivity and its proximity to the anomalous region. (author). 9 refs., 4 tabs

Opportunistic Market-Driven Regional Shifts of Cropping Practices Reduce Food Production Capacity of China

Science.gov (United States)

Yuan, Wenping; Liu, Shuguang; Liu, Wei; Zhao, Shuqing; Dong, Wenjie; Tao, Fulu; Chen, Min; Lin, Hui

2018-04-01

China is facing the challenge of feeding a growing population with the declining cropland and increasing shortage of water resources under the changing climate. This study identified that the opportunistic profit-driven shifts of planting areas and crop species composition have strongly reduced the food production capacity of China. First, the regional cultivation patterns of major crops in China have substantially shifted during the past five decades. Southeast and South China, the regions with abundant water resources and fewer natural disasters, have lost large planting areas of cropland in order to pursue industry and commerce. Meanwhile, Northeast and Northwest China, the regions with low water resources and frequent natural disasters, have witnessed increases in planting areas. These macroshifts have reduced the national food production by 1.02% per year. The lost grain production would have been enough to feed 13 million people. Second, the spatial shifts have been accompanied by major changes in crop species composition, with substantial increases in planting area and production of maize, due to its low water consumption and high economic returns. Consequently, the stockpile of maize in China has accounted for more than half of global stockpile, and the stock to use ratio of maize in China has exceeded the reliable level. Market-driven regional shifts of cropping practices have resulted in larger irrigation requirements and aggravated environmental stresses. Our results highlighted the need for Chinese food policies to consider the spatial shifts in cultivation, and the planting crop compositions limited by regional water resources and climate change.

11 CFR 9036.1 - Threshold submission.

Science.gov (United States)

2010-01-01

... credit or debit card, including one made over the Internet, the candidate shall provide sufficient... section shall not count toward the threshold amount. (c) Threshold certification by Commission. (1) After...

Photopion production from nuclei in the energy region of the Δ resonance

International Nuclear Information System (INIS)

Tamas, G.

1979-01-01

The γD→p+p+π - and the γ 4 He→p+π+3 nucleons reactions in the energy region of the Δ resonance are studied. As a temporary conclusion, it is possible to explain the largest part of the photon-nucleus interaction for D and 4 He in the Δ resonance region by the quasi-free production and the pion and proton rescattering

High-frequency (8 to 16 kHz) reference thresholds and intrasubject threshold variability relative to ototoxicity criteria using a Sennheiser HDA 200 earphone.

Science.gov (United States)

Frank, T

2001-04-01

The first purpose of this study was to determine high-frequency (8 to 16 kHz) thresholds for standardizing reference equivalent threshold sound pressure levels (RETSPLs) for a Sennheiser HDA 200 earphone. The second and perhaps more important purpose of this study was to determine whether repeated high-frequency thresholds using a Sennheiser HDA 200 earphone had a lower intrasubject threshold variability than the ASHA 1994 significant threshold shift criteria for ototoxicity. High-frequency thresholds (8 to 16 kHz) were obtained for 100 (50 male, 50 female) normally hearing (0.25 to 8 kHz) young adults (mean age of 21.2 yr) in four separate test sessions using a Sennheiser HDA 200 earphone. The mean and median high-frequency thresholds were similar for each test session and increased as frequency increased. At each frequency, the high-frequency thresholds were not significantly (p > 0.05) different for gender, test ear, or test session. The median thresholds at each frequency were similar to the 1998 interim ISO RETSPLs; however, large standard deviations and wide threshold distributions indicated very high intersubject threshold variability, especially at 14 and 16 kHz. Threshold repeatability was determined by finding the threshold differences between each possible test session comparison (N = 6). About 98% of all of the threshold differences were within a clinically acceptable range of +/-10 dB from 8 to 14 kHz. The threshold differences between each subject's second, third, and fourth minus their first test session were also found to determine whether intrasubject threshold variability was less than the ASHA 1994 criteria for determining a significant threshold shift due to ototoxicity. The results indicated a false-positive rate of 0% for a threshold shift > or = 20 dB at any frequency and a false-positive rate of 2% for a threshold shift >10 dB at two consecutive frequencies. This study verified that the output of high-frequency audiometers at 0 dB HL using

Thermotactile perception thresholds measurement conditions.

Science.gov (United States)

Maeda, Setsuo; Sakakibara, Hisataka

2002-10-01

The purpose of this paper is to investigate the effects of posture, push force and rate of temperature change on thermotactile thresholds and to clarify suitable measuring conditions for Japanese people. Thermotactile (warm and cold) thresholds on the right middle finger were measured with an HVLab thermal aesthesiometer. Subjects were eight healthy male Japanese students. The effects of posture in measurement were examined in the posture of a straight hand and forearm placed on a support, the same posture without a support, and the fingers and hand flexed at the wrist with the elbow placed on a desk. The finger push force applied to the applicator of the thermal aesthesiometer was controlled at a 0.5, 1.0, 2.0 and 3.0 N. The applicator temperature was changed to 0.5, 1.0, 1.5, 2.0 and 2.5 degrees C/s. After each measurement, subjects were asked about comfort under the measuring conditions. Three series of experiments were conducted on different days to evaluate repeatability. Repeated measures ANOVA showed that warm thresholds were affected by the push force and the rate of temperature change and that cold thresholds were influenced by posture and push force. The comfort assessment indicated that the measurement posture of a straight hand and forearm laid on a support was the most comfortable for the subjects. Relatively high repeatability was obtained under measurement conditions of a 1 degrees C/s temperature change rate and a 0.5 N push force. Measurement posture, push force and rate of temperature change can affect the thermal threshold. Judging from the repeatability, a push force of 0.5 N and a temperature change of 1.0 degrees C/s in the posture with the straight hand and forearm laid on a support are recommended for warm and cold threshold measurements.

DOE approach to threshold quantities

International Nuclear Information System (INIS)

Wickham, L.E.; Kluk, A.F.; Department of Energy, Washington, DC)

1985-01-01

The Department of Energy (DOE) is developing the concept of threshold quantities for use in determining which waste materials must be handled as radioactive waste and which may be disposed of as nonradioactive waste at its sites. Waste above this concentration level would be managed as radioactive or mixed waste (if hazardous chemicals are present); waste below this level would be handled as sanitary waste. Ideally, the threshold must be set high enough to significantly reduce the amount of waste requiring special handling. It must also be low enough so that waste at the threshold quantity poses a very small health risk and multiple exposures to such waste would still constitute a small health risk. It should also be practical to segregate waste above or below the threshold quantity using available instrumentation. Guidance is being prepared to aid DOE sites in establishing threshold quantity values based on pathways analysis using site-specific parameters (waste stream characteristics, maximum exposed individual, population considerations, and site specific parameters such as rainfall, etc.). A guidance dose of between 0.001 to 1.0 mSv/y (0.1 to 100 mrem/y) was recommended with 0.3 mSv/y (30 mrem/y) selected as the guidance dose upon which to base calculations. Several tasks were identified, beginning with the selection of a suitable pathway model for relating dose to the concentration of radioactivity in the waste. Threshold concentrations corresponding to the guidance dose were determined for waste disposal sites at a selected humid and arid site. Finally, cost-benefit considerations at the example sites were addressed. The results of the various tasks are summarized and the relationship of this effort with related developments at other agencies discussed

Critical review and hydrologic application of threshold detection methods for the generalized Pareto (GP) distribution

Science.gov (United States)

Mamalakis, Antonios; Langousis, Andreas; Deidda, Roberto

2016-04-01

Estimation of extreme rainfall from data constitutes one of the most important issues in statistical hydrology, as it is associated with the design of hydraulic structures and flood water management. To that extent, based on asymptotic arguments from Extreme Excess (EE) theory, several studies have focused on developing new, or improving existing methods to fit a generalized Pareto (GP) distribution model to rainfall excesses above a properly selected threshold u. The latter is generally determined using various approaches, such as non-parametric methods that are intended to locate the changing point between extreme and non-extreme regions of the data, graphical methods where one studies the dependence of GP distribution parameters (or related metrics) on the threshold level u, and Goodness of Fit (GoF) metrics that, for a certain level of significance, locate the lowest threshold u that a GP distribution model is applicable. In this work, we review representative methods for GP threshold detection, discuss fundamental differences in their theoretical bases, and apply them to 1714 daily rainfall records from the NOAA-NCDC open-access database, with more than 110 years of data. We find that non-parametric methods that are intended to locate the changing point between extreme and non-extreme regions of the data are generally not reliable, while methods that are based on asymptotic properties of the upper distribution tail lead to unrealistically high threshold and shape parameter estimates. The latter is justified by theoretical arguments, and it is especially the case in rainfall applications, where the shape parameter of the GP distribution is low; i.e. on the order of 0.1 ÷ 0.2. Better performance is demonstrated by graphical methods and GoF metrics that rely on pre-asymptotic properties of the GP distribution. For daily rainfall, we find that GP threshold estimates range between 2÷12 mm/d with a mean value of 6.5 mm/d, while the existence of quantization in the

Below-threshold harmonic generation from strong non-uniform fields

Science.gov (United States)

Yavuz, I.

2017-10-01

Strong-field photoemission below the ionization threshold is a rich/complex region where atomic emission and harmonic generation may coexist. We studied the mechanism of below-threshold harmonics (BTH) from spatially non-uniform local fields near the metallic nanostructures. Discrete harmonics are generated due to the broken inversion symmetry, suggesting enriched coherent emission in the vuv frequency range. Through the numerical solution of the time-dependent Schrödinger equation, we investigate wavelength and intensity dependence of BTH. Wavelength dependence identifies counter-regular resonances; individual contributions from the multi-photon emission and channel-closing effects due to quantum path interferences. In order to understand the underlying mechanism of BTH, we devised a generalized semi-classical model, including the influence of Coulomb and non-uniform field interactions. As in uniform fields, Coulomb potential in non-uniform fields is the determinant of BTH; we observed that the generation of BTH are due to returning trajectories with negative energies. Due to large distance effectiveness of the non-uniformity, only long trajectories are noticeably affected.

The optimal trackability threshold of fractional anisotropy for diffusion tensor tractography of the corticospinal tract

International Nuclear Information System (INIS)

Kunimatsu, Akira; Aoki, Shigeki; Masutani, Yoshitaka; Abe, Osamu; Hayashi, Naoto; Mori, Harushi; Masumoto, Tomohiko; Ohtomo, Kuni

2004-01-01

In order to ensure that three-dimensional diffusion tensor tractography (3D-DTT) of the corticospinal tract (CST), is performed accurately and efficiently, we set out to find the optimal lower threshold of fractional anisotropy (FA) below which tract elongation is terminated (trackability threshold). Thirteen patients with acute or early subacute ischemic stroke causing motor deficits were enrolled in this study. We performed 3D-DTT of the CST with diffusion tensor MR (magnetic resonance) imaging. We segmented the CST and established a cross-section of the CST in a transaxial plane as a region of interest. Thus, we selectively measured the FA values of the right and left corticospinal tracts at the level of the cerebral peduncle, the posterior limb of the internal capsule, and the centrum semiovale. The FA values of the CST were also measured on the affected side at the level where the clinically relevant infarction was present in isotropic diffusion-weighted imaging. 3D-DTT allowed us to selectively measure the FA values of the CST. Among the 267 regions of interest we measured, the minimum FA value was 0.22. The FA values of the CST were smaller and more variable in the centrum semiovale than in the other regions. The mean minus twice the standard deviation of the FA values of the CST in the centrum semiovale was calculated at 0.22 on the normal unaffected side and 0.16 on the affected side. An FA value of about 0.20 was found to be the optimal trackability threshold. (author)

Doubler system quench detection threshold

International Nuclear Information System (INIS)

Kuepke, K.; Kuchnir, M.; Martin, P.

1983-01-01

The experimental study leading to the determination of the sensitivity needed for protecting the Fermilab Doubler from damage during quenches is presented. The quench voltage thresholds involved were obtained from measurements made on Doubler cable of resistance x temperature and voltage x time during quenches under several currents and from data collected during operation of the Doubler Quench Protection System as implemented in the B-12 string of 20 magnets. At 4kA, a quench voltage threshold in excess of 5.OV will limit the peak Doubler cable temperature to 452K for quenches originating in the magnet coils whereas a threshold of 0.5V is required for quenches originating outside of coils

In-situ observation of the energy dependence of defect production in Cu and Ni

International Nuclear Information System (INIS)

King, W.E.; Merkel, K.L.; Baily, A.C.; Haga, K.; Meshii, M.

1983-01-01

The damage function, the average number of Frenkel pairs created as a function of lattice atom recoil energy, was investigated in Cu and Ni using in-situ electrical-resistivity damage-rate measurements in the high-voltage electron micrscope (HVEM) at T < 10K. Electron and proton irradiations were performed in-situ on the same polycrystalline specimens using the Argonne National Laboratory HVEM-Ion Beam Interface. Both Ni and Cu exhibit a sharp rise in the damage function above the minimum threshold energy (approx. 18 eV for Cu and approx. 20 eV for Ni) as displacements in the low-threshold energy regions of the threshold energy surface become possible. A plateau is observed for both materials (0.54 Frenkel pairs for Cu and 0.46 Frenkel pairs for Ni) indicating that no further directions become productive until much higher recoil energies. These damage functions show strong deviations from simple theoretical models, such as the Modified Kinchin-Pease damage function. The results are discussed in terms of the mechanisms of defect production that govern the single-displacement regime of the damage function and are compared with results from recent molecular-dynamics simulations

Photodissociation thresholds of OH produced from CH sub 3 OH in solid neon and argon

CERN Document Server

Cheng, B M; Lo, W J; Lee, Y P

2001-01-01

Photodissociation thresholds of OH from CH sub 3 OH in solid Ne and Ar were determined via photolysis of CH sub 3 OH/Ne and CH sub 3 OH/Ar (1/200) samples in situ at 4 K. The samples were irradiated with VUV synchrotron radiation after dispersion by a Seya-Namioka monochromator. The OH photo-product was detected by means of laser-induced fluorescence technique. The increase of fluorescent intensity of OH was monitored and recorded after the matrix sample was irradiated at different wavelengths for 3-5 min. Photodissociation threshold energies of 7.13+-0.02 eV (174.0+-0.5 nm) and 7.08+-0.04 eV (175.0+-1.0 nm) were measured for OH production of CH sub 3 OH in solid Ne and Ar, respectively.

Reaction thresholds in doubly special relativity

International Nuclear Information System (INIS)

Heyman, Daniel; Major, Seth; Hinteleitner, Franz

2004-01-01

Two theories of special relativity with an additional invariant scale, 'doubly special relativity', are tested with calculations of particle process kinematics. Using the Judes-Visser modified conservation laws, thresholds are studied in both theories. In contrast with some linear approximations, which allow for particle processes forbidden in special relativity, both the Amelino-Camelia and Magueijo-Smolin frameworks allow no additional processes. To first order, the Amelino-Camelia framework thresholds are lowered and the Magueijo-Smolin framework thresholds may be raised or lowered

Sub-LET Threshold SEE Cross Section Dependency with Ion Energy

CERN Document Server

Garcia Alia, Ruben; Brandenburg, Sytze; Brugger, Markus; Daly, Eamonn; Ferlet-Cavrois, Veronique; Gaillard, Remi; Hoeffgen, Stefan; Menicucci, Alessandra; Metzger, Stefan; Zadeh, Ali; Muschitiello, Michele; Noordeh, Emil; Santin, Giovanni; CERN. Geneva. ATS Department

2015-01-01

This study focuses on the ion species and energy dependence of the heavy ion SEE cross section in the sub-let threshold region through a set of experimental data. In addition, a Monte Carlo based model is introduced and applied, showing a good agreement with the data in the several hundred MeV/n range while evidencing large discrepancies with the measurements in the 10-30 MeV/n interval, notably for the NE ion. Such discrepancies are carefully analysed and discussed.

National and regional economic impacts of electricity production from energy crops in the Netherlands

NARCIS (Netherlands)

Vlasblom, J.; Broek, R. van den; Meeusen-van Onna, M.

1998-01-01

Besides the known environmental benefits, national and regional economic impacts may form additional arguments for stimulating government measures in favour of electricity production from energy crops in the Netherlands. Therefore, we compared the economic impacts (at both national and regional

Comparison of muscle and joint pressure-pain thresholds in patients with complex regional pain syndrome and upper limb pain of other origin.

Science.gov (United States)

Mainka, Tina; Bischoff, Florian S; Baron, Ralf; Krumova, Elena K; Nicolas, Volkmar; Pennekamp, Werner; Treede, Rolf-Detlef; Vollert, Jan; Westermann, Andrea; Maier, Christoph

2014-03-01

Pain localized in the deep tissues occurs frequently in complex regional pain syndrome (CRPS). In addition, hyperalgesia to blunt pressure over muscles is common in CRPS, but it often appears in limb pain of other origin as well. Considering that 3-phase bone scintigraphy (TPBS) reveals periarticular enhanced bone metabolism in CRPS, joint-associated hyperalgesia to blunt pressure might be a more specific finding than hyperalgesia over muscles. In 34 patients with upper limb pain (18 CRPS, 16 non-CRPS; diagnosed in accordance to the Budapest criteria) and in 18 healthy controls, pressure-pain thresholds (PPT) were assessed bilaterally over the thenar (PPTThenar), the metacarpophalangeal (PPTMCP), and the proximal interphalangeal (PPTPIP) joints using a pressure algometer (Somedic, Sweden). Beforehand, all patients had received TPBS for diagnostic purposes independently of the study. Region-of-interest (ROI) ratios (mineralization phase) for the MCP and PIP, excluding fracture sites, were correlated with the PPT. In CRPS, all ROI ratios were significantly increased and all PPT of the affected hand were decreased compared to non-CRPS (PPTThenar: 243±150kPa vs 358±197kPa, PPTMCP: 80±67kPa vs 159±93kPa, PPTPIP: 80±56kPa vs 184±110kPa; PPain. Published by Elsevier B.V. All rights reserved.

Emerging trends in regional coal production

International Nuclear Information System (INIS)

Watson, W.D.

1994-01-01

At an average annual growth rate of 1.9%, the total national demand for coal will increase from 850 million short tons in 1985 to 2 billion short tons annually by the year 2030. A market simulation model (described in this paper) determines the regional pattern of coal production needed to meet these demands. Because compliance or low-sulfur coal resources are a low-cost option for meeting environmental regulations, they could be mined out substantially in the medium term. In the next 15 to 25 years, most of the Eastern compliance coal up to a mining cost of $40 per ton could be mined out and 4 billion short tons of Western compliance coal could be produced. By the year 2030, almost all Eastern low-sulfur coal could be mined out. Most Western compliance coal costing less than $20/ton could be mined out by 2030

Thresholds in chemical respiratory sensitisation.

Science.gov (United States)

Cochrane, Stella A; Arts, Josje H E; Ehnes, Colin; Hindle, Stuart; Hollnagel, Heli M; Poole, Alan; Suto, Hidenori; Kimber, Ian

2015-07-03

There is a continuing interest in determining whether it is possible to identify thresholds for chemical allergy. Here allergic sensitisation of the respiratory tract by chemicals is considered in this context. This is an important occupational health problem, being associated with rhinitis and asthma, and in addition provides toxicologists and risk assessors with a number of challenges. In common with all forms of allergic disease chemical respiratory allergy develops in two phases. In the first (induction) phase exposure to a chemical allergen (by an appropriate route of exposure) causes immunological priming and sensitisation of the respiratory tract. The second (elicitation) phase is triggered if a sensitised subject is exposed subsequently to the same chemical allergen via inhalation. A secondary immune response will be provoked in the respiratory tract resulting in inflammation and the signs and symptoms of a respiratory hypersensitivity reaction. In this article attention has focused on the identification of threshold values during the acquisition of sensitisation. Current mechanistic understanding of allergy is such that it can be assumed that the development of sensitisation (and also the elicitation of an allergic reaction) is a threshold phenomenon; there will be levels of exposure below which sensitisation will not be acquired. That is, all immune responses, including allergic sensitisation, have threshold requirement for the availability of antigen/allergen, below which a response will fail to develop. The issue addressed here is whether there are methods available or clinical/epidemiological data that permit the identification of such thresholds. This document reviews briefly relevant human studies of occupational asthma, and experimental models that have been developed (or are being developed) for the identification and characterisation of chemical respiratory allergens. The main conclusion drawn is that although there is evidence that the

The effect of power change on the PCI failure threshold

Energy Technology Data Exchange (ETDEWEB)

Sipush, P J; Kaiser, R S [Westinghouse Nuclear Fuel Division, Pittsburg, PA (United States)

1983-06-01

Investigations of the PCI mechanism have led to the conclusion that the failure threshold is best defined by the power change ({delta}P) during the ramp, rather than the final power achieved at the end of the ramp. The data base studied was comprehensive and includes a wide variety of water reactor systems and fuel designs. It has also been found that operating parameters have a more significant effect on failure susceptibility than fuel rod design variables. The most significant operating variable affecting the failure threshold was found to be the base irradiation history, indicating that fission product release and migration prior to the ramp (during base irradiation) is an important consideration. It can be shown that fuel irradiated at relatively higher linear heat ratings ends to fail at lower {delta}P. This effect has also been independently verified by statistical analyses which will also be discussed. Industry out-of-pile internal gas pressurization tests with irradiated tubing in the absence of simulated fission product species and at low stress levels, also tends to indicate the importance of the prior irradiation history on PCI performance. Other parameters that affect the power ramping performance are the initial ramping power and the pellet power distribution which is a function of fuel enrichment and burnup. (author)

Regional Changes in the Sea Ice Cover and Ice Production in the Antarctic

Science.gov (United States)

Comiso, Josefino C.

2011-01-01

Coastal polynyas around the Antarctic continent have been regarded as sea ice factories because of high ice production rates in these regions. The observation of a positive trend in the extent of Antarctic sea ice during the satellite era has been intriguing in light of the observed rapid decline of the ice extent in the Arctic. The results of analysis of the time series of passive microwave data indicate large regional variability with the trends being strongly positive in the Ross Sea, strongly negative in the Bellingshausen/Amundsen Seas and close to zero in the other regions. The atmospheric circulation in the Antarctic is controlled mainly by the Southern Annular Mode (SAM) and the marginal ice zone around the continent shows an alternating pattern of advance and retreat suggesting the presence of a propagating wave (called Antarctic Circumpolar Wave) around the circumpolar region. The results of analysis of the passive microwave data suggest that the positive trend in the Antarctic sea ice cover could be caused primarily by enhanced ice production in the Ross Sea that may be associated with more persistent and larger coastal polynyas in the region. Over the Ross Sea shelf, analysis of sea ice drift data from 1992 to 2008 yields a positive rate-of-increase in the net ice export of about 30,000 km2 per year. For a characteristic ice thickness of 0.6 m, this yields a volume transport of about 20 km3/year, which is almost identical, within error bars, to our estimate of the trend in ice production. In addition to the possibility of changes in SAM, modeling studies have also indicated that the ozone hole may have a role in that it causes the deepening of the lows in the western Antarctic region thereby causing strong winds to occur offthe Ross-ice shelf.

A Novel Histogram Region Merging Based Multithreshold Segmentation Algorithm for MR Brain Images

Directory of Open Access Journals (Sweden)

Siyan Liu

2017-01-01

Full Text Available Multithreshold segmentation algorithm is time-consuming, and the time complexity will increase exponentially with the increase of thresholds. In order to reduce the time complexity, a novel multithreshold segmentation algorithm is proposed in this paper. First, all gray levels are used as thresholds, so the histogram of the original image is divided into 256 small regions, and each region corresponds to one gray level. Then, two adjacent regions are merged in each iteration by a new designed scheme, and a threshold is removed each time. To improve the accuracy of the merger operation, variance and probability are used as energy. No matter how many the thresholds are, the time complexity of the algorithm is stable at O(L. Finally, the experiment is conducted on many MR brain images to verify the performance of the proposed algorithm. Experiment results show that our method can reduce the running time effectively and obtain segmentation results with high accuracy.

Optimizing Systems of Threshold Detection Sensors

National Research Council Canada - National Science Library

Banschbach, David C

2008-01-01

.... Below the threshold all signals are ignored. We develop a mathematical model for setting individual sensor thresholds to obtain optimal probability of detecting a significant event, given a limit on the total number of false positives allowed...

Beauty and charm production in fixed target experiments

International Nuclear Information System (INIS)

Kidonakis, Nikolaos; Vogt, Ramona

2004-01-01

We present calculations of NNLO threshold corrections for beauty and charm production in π - p and pp interactions at fixed-target experiments. Recent calculations for heavy quark hadroproduction have included next-to-next-to-leading-order (NNLO) soft-gluon corrections [1] to the double differential cross section from threshold resummation techniques [2]. These corrections are important for near-threshold beauty and charm production at fixed-target experiments, including HERA-B and some of the current and future heavy ion experiments

Identifying Threshold Concepts for Information Literacy: A Delphi Study

Directory of Open Access Journals (Sweden)

Lori Townsend

2016-06-01

Full Text Available This study used the Delphi method to engage expert practitioners on the topic of threshold concepts for information literacy. A panel of experts considered two questions. First, is the threshold concept approach useful for information literacy instruction? The panel unanimously agreed that the threshold concept approach holds potential for information literacy instruction. Second, what are the threshold concepts for information literacy instruction? The panel proposed and discussed over fifty potential threshold concepts, finally settling on six information literacy threshold concepts.

Production of deuterons in hA collisions at high energies in the target fragmentation region

International Nuclear Information System (INIS)

Braun, M.A.; Vechernin, V.V.

1987-01-01

The production of relativistic deuterons in the target fragmentation region is studied. It is shown that for fast deuterons the role of the nuclear field is small and is not determined by the Butler-Pearson formulae. The main contribution comes from the direct coalescence into the deuteron of nucleons produced either at one point in the nucleus or at two different points. In the forward hemisphere for purely geometrical reasons the production at two points dominates, whereas in the backward hemisphere (the ''cumulative region'') the production at one point and at two different points may give contributions of the same order

77 FR 24385 - Approval and Promulgation of Air Quality Implementation Plans; Maine; Regional Haze

Science.gov (United States)

2012-04-24

... Wisconsin), Maine lacks a State cost effectiveness threshold in its Best Available Retrofit Technology (BART... by these States. Response: While States have the option to develop a cost effectiveness threshold, the Regional Haze Rule does not require States to set a bright line threshold for cost effectiveness...

Multiuser switched diversity scheduling systems with per-user threshold

KAUST Repository

Nam, Haewoon

2010-05-01

A multiuser switched diversity scheduling scheme with per-user feedback threshold is proposed and analyzed in this paper. The conventional multiuser switched diversity scheduling scheme uses a single feedback threshold for every user, where the threshold is a function of the average signal-to-noise ratios (SNRs) of the users as well as the number of users involved in the scheduling process. The proposed scheme, however, constructs a sequence of feedback thresholds instead of a single feedback threshold such that each user compares its channel quality with the corresponding feedback threshold in the sequence. Numerical and simulation results show that thanks to the flexibility of threshold selection, where a potentially different threshold can be used for each user, the proposed scheme provides a higher system capacity than that for the conventional scheme. © 2006 IEEE.

Measurements of NN→dπ very near threshold. Pt. 2

International Nuclear Information System (INIS)

Korkmaz, E.; Li, Jin; Elliott, J.B.; Mack, D.J.; Rodning, N.L.; Hutcheon, D.A.; Abegg, R.; Greeniaus, L.G.; Miller, C.A.

1991-01-01

We have measured analyzing powers for the reaction pp→dπ + at beam energies 3 and 7 MeV above pion-production threshold. With the use of Watson's theorem to fix phases and effective range estimates of pion d-wave strength, we have been able to determine the NN→dπ s-wave amplitude and the major p-wave amplitude at these energies. The results are compared to the Faddeev model predictions of Blankleider. (orig.)

Rainfall threshold calculation for debris flow early warning in areas with scarcity of data

Science.gov (United States)

Pan, Hua-Li; Jiang, Yuan-Jun; Wang, Jun; Ou, Guo-Qiang

2018-05-01

Debris flows are natural disasters that frequently occur in mountainous areas, usually accompanied by serious loss of lives and properties. One of the most commonly used approaches to mitigate the risk associated with debris flows is the implementation of early warning systems based on well-calibrated rainfall thresholds. However, many mountainous areas have little data regarding rainfall and hazards, especially in debris-flow-forming regions. Therefore, the traditional statistical analysis method that determines the empirical relationship between rainstorms and debris flow events cannot be effectively used to calculate reliable rainfall thresholds in these areas. After the severe Wenchuan earthquake, there were plenty of deposits deposited in the gullies, which resulted in several debris flow events. The triggering rainfall threshold has decreased obviously. To get a reliable and accurate rainfall threshold and improve the accuracy of debris flow early warning, this paper developed a quantitative method, which is suitable for debris flow triggering mechanisms in meizoseismal areas, to identify rainfall threshold for debris flow early warning in areas with a scarcity of data based on the initiation mechanism of hydraulic-driven debris flow. First, we studied the characteristics of the study area, including meteorology, hydrology, topography and physical characteristics of the loose solid materials. Then, the rainfall threshold was calculated by the initiation mechanism of the hydraulic debris flow. The comparison with other models and with alternate configurations demonstrates that the proposed rainfall threshold curve is a function of the antecedent precipitation index (API) and 1 h rainfall. To test the proposed method, we selected the Guojuanyan gully, a typical debris flow valley that during the 2008-2013 period experienced several debris flow events, located in the meizoseismal areas of the Wenchuan earthquake, as a case study. The comparison with other

Evaluation of the cross-sections of threshold reactions leading to the production of long-lived radionuclides during irradiation of steels by thermonuclear spectrum neutrons

CERN Document Server

Blokhin, A I; Manokhin, V N; Mikhajlyukova, M V; Nasyrova, S M; Skripova, M V

2001-01-01

The present paper analyses and evaluates the cross-sections of threshold reactions leading to the production of long-lived radionuclides during the irradiation, by thermonuclear spectrum neutrons, of steels containing V, Ti, Cr, Fe and Ni. On the basis of empirical systematics. a new evaluation of the (n,2n), (n,p), (n,np), (n,alpha) and (n,n alpha) excitation functions is made for all isotopes of V, Ti, Cr, Fe and Ni and for intermediate isotopes produced in the chain from irradiated isotopes up to production of the long-lived radionuclides sup 3 sup 9 Ar, sup 4 sup 2 Ar, sup 4 sup 1 Ca, sup 5 sup 3 Mn, sup 6 sup 0 Fe, sup 6 sup 0 Co, sup 5 sup 9 Ni and sup 6 sup 3 Ni. A comparison is made with the experimental and other evaluated data.

Study of $\\pi^{-}\\pi^{0}$ production via Primakoff effect on nuclei

CERN Multimedia

2002-01-01

The proposed experiment makes use of the FRAMM spectrometer (experiments NA1 and NA7). The aim of the experiment is to study the reaction $\\pi^{-}$Pb $\\rightarrow \\pi^{-}\\pi^{0}$Pb via Primakoff effect in order to measure the radiative decay width $\\Gamma(\\rho^{-} \\rightarrow \\pi^{-}\\gamma)$ of the $\\rho^{-}$meson and to measure the cross-section of the reaction at threshold. \\\\\\\\The controversial data on $\\Gamma(\\rho^{-} \\rightarrow \\pi^{-}\\gamma)$ and the theoretical importance of this process justify a high statistics study of the reaction in the $\\rho^{-}$ region.\\\\\\\\ The physical interest of the measurement of the $\\pi^{-}\\pi^{0}$ production cross-section at threshold is to check the validity of the low energy theorem for the $\\gamma \\rightarrow 3\\pi$ vertex (Adler, Bell and Jackiw anomalies) and to obtain a direct determination

Assessment of the results of the strategic orientation on regional and local products in food retail

Directory of Open Access Journals (Sweden)

Kamil Pícha

2013-01-01

Full Text Available The aim of this paper is to assess if there is a difference in food choice behaviour between regular customers of stores of the retail chain Terno and other consumers. Consequently, the paper aims to discover, if the strategy formulated by the consumer co-operative Jednota České Budějovice was a good strategy. The core of this strategy is the orientation on the region, local and regional food and food products and the co-operation with local small and medium suppliers. Another part of this strategy is also the permanent control of quality of these products and creation of the special private label – Quality food from our region. The consumer co-operative co-operates also with the regional grouping under another label – Tastes great. Southbohemian. The assessment is done by means of the analysis of a questionnaire survey that was done among consumers in the South Bohemia in 2011. The strongest factor differentiating customers of the retail chain TERNO from other consumer is the orientation on regional or local products, which explains about 41% of variability. Other differentiating factors are environment-friendly production and selling and quality of food. All these three factors explain in total 66.5% of variability of the data set.

The regional control of the canadian energy production

International Nuclear Information System (INIS)

Petitlaurent, S.; Sarrazin, J.

2004-12-01

This document provides information and presents data on the energy situation in many regions of Canada. The first part deals with the petroleum and the bitumen shales of Alberta (reserves, exploitation and production, environmental impacts), the second part discusses with the hydroelectricity choice of Quebec and the 2004 crisis. The nuclear situation of Ontario is presented in the third part (nuclear park, programs, uranium reserves, research and development on Candu reactors), while the fourth part deals with the renewable energies (wind power and biomass). The canadian situation facing the Kyoto protocol is discussed in the last part. (A.L.B.)

The Value Chains of High-Technology Products as Factor of formation the Regional Comprehensive Economic Partnership

Directory of Open Access Journals (Sweden)

Irina A. Safronova

2016-01-01

Full Text Available This article analyzes the value chain of high-tech products in Asia and the role of this phenomenon in the further consolidation of trade blocs and alliances in the region. The presence of these chains and their gradual transition from a vertically integrated model to a system of horizontal linkages and interdependence leads to the formation of mechanisms of economic de-facto integration (so-called regionalization process. The East Asian region has demonstrated unprecedented high rates of economic growth in recent decades. The countries are actively developing mechanisms of multilateral cooperation, involving partners from across the Asia-Pacific region. Particular features of a new regional architecture of economic relations are becoming more tangible, and the essential element of this architecture is the intra-regional integration. The author presents an assessment of further developments of the Regional comprehensive economic partnership (RCEP using the structural-functional approach and analytical instruments of the international political economy, The creation of this trade block will help less advanced countries of ASEAN to accelerate economic growth and improve the conditions for integration into global value chains. For advanced economies, participation in the RCEP seems controversial, because production chains have well-established formats within the framework of ASEAN +. The political standoff between Washington and Beijing has an impact on dynamics of regional integration. The split among the East Asian countries was galvanized by the Trans-Pacific Partnership Project (TTP, because TPP has objectives that are very similar to those of RCEP (trade liberalization and economic integration. The author concludes that the extension of this partnership in the ASEAN countries can seriously complicate the operation RVEP and enhance the impact of political factors on economic cooperation. In this case, the value of production and supply chains

The concept of nuclear threshold and its political and strategic implications

International Nuclear Information System (INIS)

Sitt, Bernard

2013-07-01

literature to date. Such an approach would consist of going over the different dimensions of the nuclear threshold concept one by one and responding to a certain number of questions raised by an initial review. These questions can be divided into four categories: Those relative to the concept itself: is the threshold notion a useful concept? What does threshold mean exactly? Do several thresholds exist? What does a military nuclear capability entail? Those relative to the concept's implications for international law and arms control: are thresholds to be found in existing international instruments? Is the lack of a definition of what constitutes a nuclear weapon in the NPT problematic? Could new obligations be established that would amount to a de facto threshold (for instance, limiting States' rights under Article IV of the NPT)? Those relative to the concept's political implications: can or should a threshold be associated with a red line? How is the threshold notion perceived by different States? Those relative to the potential regional or global consequences of crossing a threshold: what can or should the international community's reaction be? Does the nuclear non-proliferation regime possess the necessary resilience to react or adapt? In various respects, the last category of questions is the most crucial. As suggested above, the emergence of a new nuclear-weapon-capable country has foiled the international community on several occasions. Is this kind of occurrence inevitable or can other diplomatic strategies, which could be coercive where necessary, be found? (author)

Setting limits: Using air pollution thresholds to protect and restore US ecosystems

Science.gov (United States)

Fenn, Mark E.; Lambert, Kathleen F.; Blett, Tamara F.; Burns, Douglas A.; Pardo, Linda H.; Lovett, Gary M.; Haeuber, Richard A.; Evers, David C.; Driscoll, Charles T.; Jeffries, Dean S.

2011-01-01

More than four decades of research provide unequivocal evidence that sulfur, nitrogen, and mercury pollution have altered, and will continue to alter, our nation's lands and waters. The emission and deposition of air pollutants harm native plants and animals, degrade water quality, affect forest productivity, and are damaging to human health. Many air quality policies limit emissions at the source but these control measures do not always consider ecosystem impacts. Air pollution thresholds at which ecological effects are observed, such as critical loads, are effective tools for assessing the impacts of air pollution on essential ecosystem services and for informing public policy. U.S. ecosystems can be more effectively protected and restored by using a combination of emissions-based approaches and science-based thresholds of ecosystem damage.

Computerized detection of multiple sclerosis candidate regions based on a level set method using an artificial neural network

International Nuclear Information System (INIS)

Kuwazuru, Junpei; Magome, Taiki; Arimura, Hidetaka; Yamashita, Yasuo; Oki, Masafumi; Toyofuku, Fukai; Kakeda, Shingo; Yamamoto, Daisuke

2010-01-01

Yamamoto et al. developed the system for computer-aided detection of multiple sclerosis (MS) candidate regions. In a level set method in their proposed method, they employed the constant threshold value for the edge indicator function related to a speed function of the level set method. However, it would be appropriate to adjust the threshold value to each MS candidate region, because the edge magnitudes in MS candidates differ from each other. Our purpose of this study was to develop a computerized detection of MS candidate regions in MR images based on a level set method using an artificial neural network (ANN). To adjust the threshold value for the edge indicator function in the level set method to each true positive (TP) and false positive (FP) region, we constructed the ANN. The ANN could provide the suitable threshold value for each candidate region in the proposed level set method so that TP regions can be segmented and FP regions can be removed. Our proposed method detected MS regions at a sensitivity of 82.1% with 0.204 FPs per slice and similarity index of MS candidate regions was 0.717 on average. (author)

Pain thresholds, supra-threshold pain and lidocaine sensitivity in patients with erythromelalgia, including the I848Tmutation in NaV 1.7.

Science.gov (United States)

Helås, T; Sagafos, D; Kleggetveit, I P; Quiding, H; Jönsson, B; Segerdahl, M; Zhang, Z; Salter, H; Schmelz, M; Jørum, E

2017-09-01

Nociceptive thresholds and supra-threshold pain ratings as well as their reduction upon local injection with lidocaine were compared between healthy subjects and patients with erythromelalgia (EM). Lidocaine (0.25, 0.50, 1.0 or 10 mg/mL) or placebo (saline) was injected intradermally in non-painful areas of the lower arm, in a randomized, double-blind manner, to test the effect on dynamic and static mechanical sensitivity, mechanical pain sensitivity, thermal thresholds and supra-threshold heat pain sensitivity. Heat pain thresholds and pain ratings to supra-threshold heat stimulation did not differ between EM-patients (n = 27) and controls (n = 25), neither did the dose-response curves for lidocaine. Only the subgroup of EM-patients with mutations in sodium channel subunits Na V 1.7, 1.8 or 1.9 (n = 8) had increased lidocaine sensitivity for supra-threshold heat stimuli, contrasting lower sensitivity to strong mechanical stimuli. This pattern was particularly clear in the two patients carrying the Na V 1.7 I848T mutations in whom lidocaine's hyperalgesic effect on mechanical pain sensitivity contrasted more effective heat analgesia. Heat pain thresholds are not sensitized in EM patients, even in those with gain-of-function mutations in Na V 1.7. Differential lidocaine sensitivity was overt only for noxious stimuli in the supra-threshold range suggesting that sensitized supra-threshold encoding is important for the clinical pain phenotype in EM in addition to lower activation threshold. Intracutaneous lidocaine dose-dependently blocked nociceptive sensations, but we did not identify EM patients with particular high lidocaine sensitivity that could have provided valuable therapeutic guidance. Acute pain thresholds and supra-threshold heat pain in controls and patients with erythromelalgia do not differ and have the same lidocaine sensitivity. Acute heat pain thresholds even in EM patients with the Na V 1.7 I848T mutation are normal and only nociceptor

Relieving dyspnoea by non-invasive ventilation decreases pain thresholds in amyotrophic lateral sclerosis.

Science.gov (United States)

Dangers, Laurence; Laviolette, Louis; Georges, Marjolaine; Gonzalez-Bermejo, Jésus; Rivals, Isabelle; Similowski, Thomas; Morelot-Panzini, Capucine

2017-03-01

Dyspnoea is a threatening sensation of respiratory discomfort that presents many similarities with pain. Experimental dyspnoea in healthy subjects induces analgesia. This 'dyspnoea-pain counter-irritation' could, in reverse, imply that relieving dyspnoea in patients with chronic respiratory diseases would lower their pain thresholds. We first determined pressure pain thresholds in 25 healthy volunteers (22-31 years; 13 men; handheld algometer), during unloaded breathing (BASELINE) and during inspiratory threshold loading (ITL). Two levels of loading were used, adjusted to induce dyspnoea self-rated at 60% or 80% of a 10 cm visual analogue scale (ITL6 and ITL8). 18 patients with chronic respiratory failure due to amyotrophic lateral sclerosis (ALS) were then studied during unassisted breathing and after 30 and 60 min of non-invasive ventilation-NIV30 and NIV60-(same dyspnoea evaluation). In healthy volunteers, pressure pain thresholds increased significantly in the deltoid during ITL6 (pNIV30 and NIV60 (pNIV in patients with ALS having respiratory failure is associated with decreased pressure pain thresholds. Clinical implications have yet to be determined, but this observation suggests that patients with ALS could become more susceptible to pain after the institution of NIV, hence the need for reinforced attention towards potentially painful diagnostic and therapeutic interventions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Impacts of Marcellus Shale Natural Gas Production on Regional Air Quality

Science.gov (United States)

Swarthout, R.; Russo, R. S.; Zhou, Y.; Mitchell, B.; Miller, B.; Lipsky, E. M.; Sive, B. C.

2012-12-01

Natural gas is a clean burning alternative to other fossil fuels, producing lower carbon dioxide (CO2) emissions during combustion. Gas deposits located within shale rock or tight sand formations are difficult to access using conventional drilling techniques. However, horizontal drilling coupled with hydraulic fracturing is now widely used to enhance natural gas extraction. Potential environmental impacts of these practices are currently being assessed because of the rapid expansion of natural gas production in the U.S. Natural gas production has contributed to the deterioration of air quality in several regions, such as in Wyoming and Utah, that were near or downwind of natural gas basins. We conducted a field campaign in southwestern Pennsylvania on 16-18 June 2012 to investigate the impact of gas production operations in the Marcellus Shale on regional air quality. A total of 235 whole air samples were collected in 2-liter electropolished stainless- steel canisters throughout southwestern Pennsylvania in a regular grid pattern that covered an area of approximately 8500 square km. Day and night samples were collected at each grid point and additional samples were collected near active wells, flaring wells, fluid retention reservoirs, transmission pipelines, and a processing plant to assess the influence of different stages of the gas production operation on emissions. The samples were analyzed at Appalachian State University for methane (CH4), CO2, C2-C10 nonmethane hydrocarbons (NMHCs), C1-C2 halocarbons, C1-C5 alkyl nitrates and selected reduced sulfur compounds. In-situ measurements of ozone (O3), CH4, CO2, nitric oxide (NO), total reactive nitrogen (NOy), formaldehyde (HCHO), and a range of volatile organic compounds (VOCs) were carried out at an upwind site and a site near active gas wells using a mobile lab. Emissions associated with gas production were observed throughout the study region. Elevated mixing ratios of CH4 and CO2 were observed in the

When do price thresholds matter in retail categories?

OpenAIRE

Pauwels, Koen; Srinivasan, Shuba; Franses, Philip Hans

2007-01-01

textabstractMarketing literature has long recognized that brand price elasticity need not be monotonic and symmetric, but has yet to provide generalizable market-level insights on threshold-based price elasticity, asymmetric thresholds, and the sign and magnitude of elasticity transitions. This paper introduces smooth transition regression models to study threshold-based price elasticity of the top 4 brands across 20 fast-moving consumer good categories. Threshold-based price elasticity is fo...

Simple Model for Identifying Critical Regions in Atrial Fibrillation

Science.gov (United States)

Christensen, Kim; Manani, Kishan A.; Peters, Nicholas S.

2015-01-01

Atrial fibrillation (AF) is the most common abnormal heart rhythm and the single biggest cause of stroke. Ablation, destroying regions of the atria, is applied largely empirically and can be curative but with a disappointing clinical success rate. We design a simple model of activation wave front propagation on an anisotropic structure mimicking the branching network of heart muscle cells. This integration of phenomenological dynamics and pertinent structure shows how AF emerges spontaneously when the transverse cell-to-cell coupling decreases, as occurs with age, beyond a threshold value. We identify critical regions responsible for the initiation and maintenance of AF, the ablation of which terminates AF. The simplicity of the model allows us to calculate analytically the risk of arrhythmia and express the threshold value of transversal cell-to-cell coupling as a function of the model parameters. This threshold value decreases with increasing refractory period by reducing the number of critical regions which can initiate and sustain microreentrant circuits. These biologically testable predictions might inform ablation therapies and arrhythmic risk assessment.

A real-time regional adaptive exposure method for saving dose-area product in x-ray fluoroscopy

International Nuclear Information System (INIS)

Burion, Steve; Funk, Tobias; Speidel, Michael A.

2013-01-01

Purpose: Reduction of radiation dose in x-ray imaging has been recognized as a high priority in the medical community. Here the authors show that a regional adaptive exposure method can reduce dose-area product (DAP) in x-ray fluoroscopy. The authors' method is particularly geared toward providing dose savings for the pediatric population. Methods: The scanning beam digital x-ray system uses a large-area x-ray source with 8000 focal spots in combination with a small photon-counting detector. An imaging frame is obtained by acquiring and reconstructing up to 8000 detector images, each viewing only a small portion of the patient. Regional adaptive exposure was implemented by varying the exposure of the detector images depending on the local opacity of the object. A family of phantoms ranging in size from infant to obese adult was imaged in anteroposterior view with and without adaptive exposure. The DAP delivered to each phantom was measured in each case, and noise performance was compared by generating noise arrays to represent regional noise in the images. These noise arrays were generated by dividing the image into regions of about 6 mm 2 , calculating the relative noise in each region, and placing the relative noise value of each region in a one-dimensional array (noise array) sorted from highest to lowest. Dose-area product savings were calculated as the difference between the ratio of DAP with adaptive exposure to DAP without adaptive exposure. The authors modified this value by a correction factor that matches the noise arrays where relative noise is the highest to report a final dose-area product savings. Results: The average dose-area product saving across the phantom family was (42 ± 8)% with the highest dose-area product saving in the child-sized phantom (50%) and the lowest in the phantom mimicking an obese adult (23%). Conclusions: Phantom measurements indicate that a regional adaptive exposure method can produce large DAP savings without compromising

Regional air quality impacts of increased natural gas production and use in Texas.

Science.gov (United States)

Pacsi, Adam P; Alhajeri, Nawaf S; Zavala-Araiza, Daniel; Webster, Mort D; Allen, David T

2013-04-02

Natural gas use in electricity generation in Texas was estimated, for gas prices ranging from $1.89 to $7.74 per MMBTU, using an optimal power flow model. Hourly estimates of electricity generation, for individual electricity generation units, from the model were used to estimate spatially resolved hourly emissions from electricity generation. Emissions from natural gas production activities in the Barnett Shale region were also estimated, with emissions scaled up or down to match demand in electricity generation as natural gas prices changed. As natural gas use increased, emissions decreased from electricity generation and increased from natural gas production. Overall, NOx and SO2 emissions decreased, while VOC emissions increased as natural gas use increased. To assess the effects of these changes in emissions on ozone and particulate matter concentrations, spatially and temporally resolved emissions were used in a month-long photochemical modeling episode. Over the month-long photochemical modeling episode, decreases in natural gas prices typical of those experienced from 2006 to 2012 led to net regional decreases in ozone (0.2-0.7 ppb) and fine particulate matter (PM) (0.1-0.7 μg/m(3)). Changes in PM were predominantly due to changes in regional PM sulfate formation. Changes in regional PM and ozone formation are primarily due to decreases in emissions from electricity generation. Increases in emissions from increased natural gas production were offset by decreasing emissions from electricity generation for all the scenarios considered.

Acrolein-stressed threshold adaptation alters the molecular and metabolic bases of an engineered Saccharomyces cerevisiae to improve glutathione production.

Science.gov (United States)

Zhou, Wenlong; Yang, Yan; Tang, Liang; Cheng, Kai; Li, Changkun; Wang, Huimin; Liu, Minzhi; Wang, Wei

2018-03-14

Acrolein (Acr) was used as a selection agent to improve the glutathione (GSH) overproduction of the prototrophic strain W303-1b/FGP PT . After two rounds of adaptive laboratory evolution (ALE), an unexpected result was obtained wherein identical GSH production was observed in the selected isolates. Then, a threshold selection mechanism of Acr-stressed adaption was clarified based on the formation of an Acr-GSH adduct, and a diffusion coefficient (0.36 ± 0.02 μmol·min -1 ·OD 600 -1 ) was calculated. Metabolomic analysis was carried out to reveal the molecular bases that triggered GSH overproduction. The results indicated that all three precursors (glutamic acid (Glu), glycine (Gly) and cysteine (Cys)) needed for GSH synthesis were at a relativity higher concentration in the evolved strain and that the accumulation of homocysteine (Hcy) and cystathionine might promote Cys synthesis and then improve GSH production. In addition to GSH and Cys, it was observed that other non-protein thiols and molecules related to ATP generation were at obviously different levels. To divert the accumulated thiols to GSH biosynthesis, combinatorial strategies, including deletion of cystathionine β-lyase (STR3), overexpression of cystathionine γ-lyase (CYS3) and cystathionine β-synthase (CYS4), and reduction of the unfolded protein response (UPR) through up-regulation of protein disulphide isomerase (PDI), were also investigated.