Shear Creep Simulation of Structural Plane of Rock Mass Based on Discontinuous Deformation Analysis

Directory of Open Access Journals (Sweden)

Guoxin Zhang

2017-01-01

Full Text Available Numerical simulations of the creep characteristics of the structural plane of rock mass are very useful. However, most existing simulation methods are based on continuum mechanics and hence are unsuitable in the case of large displacements and deformations. The discontinuous deformation analysis method proposed by Genhua is a discrete one and has a significant advantage when simulating the contacting problem of blocks. In this study, we combined the viscoelastic rheological model of Burgers with the discontinuous deformation analysis (DDA method. We also derived the recurrence formula for the creep deformation increment with the time step during numerical simulations. Based on the minimum potential energy principle, the general equilibrium equation was derived, and the shear creep deformation in the structural plane was considered. A numerical program was also developed and its effectiveness was confirmed based on the curves obtained by the creep test of the structural plane of a rock mass under different stress levels. Finally, the program was used to analyze the mechanism responsible for the creep features of the structural plane in the case of the toppling deformation of the rock slope. The results showed that the extended DDA method is an effective one.

On the stability of rotational discontinuities and intermediate shocks

International Nuclear Information System (INIS)

Lee, L.C.; Huang, L.; Chao, J.K.

1989-01-01

The stability of rotational discontinuities and intermediate shocks is studied based on a hybrid simulation code. The simulation results show that rotational discontinuities are stable and intermediate shocks are not stationary. Intermediate shocks tend to evolve to rotational discontinuities and waves. The authors employ several different initial profiles for the magnetic field in the transition region and find that the final structure of the discontinuities or shocks is not sensitive to the initial magnetic field profile. The present results are different from those obtained from the resistive MHD simulations. Furthermore, their study indicates that the kinetic effect of particles plays an important role in the structure and stability of rotational discontinuities and intermediate shocks

Airline loyalty (programs) across borders : A geographic discontinuity approach

NARCIS (Netherlands)

de Jong, Gerben; Behrens, Christiaan; van Ommeren, Jos

2018-01-01

We analyze brand loyalty advantages of national airlines in their domestic countries using geocoded data from a major international frequent flier program. We employ a geographic discontinuity design that estimates discontinuities in program activity at the national borders of the program's

Prediction of residues in discontinuous B-cell epitopes using protein 3D structures

DEFF Research Database (Denmark)

Andersen, P.H.; Nielsen, Morten; Lund, Ole

2006-01-01

. We show that the new structure-based method has a better performance for predicting residues of discontinuous epitopes than methods based solely on sequence information, and that it can successfully predict epitope residues that have been identified by different techniques. DiscoTope detects 15...... experimental epitope mapping in both rational vaccine design and development of diagnostic tools, and may lead to more efficient epitope identification....

Delirium Associated With Fluoxetine Discontinuation: A Case Report.

Science.gov (United States)

Fan, Kuang-Yuan; Liu, Hsing-Cheng

Withdrawal symptoms on selective serotonin reuptake inhibitor (SSRI) discontinuation have raised clinical attention increasingly. However, delirium is rarely reported in the SSRI discontinuation syndrome. We report a case of delirium developing after fluoxetine discontinuation in a 65-year-old female patient with major depressive disorder. She experienced psychotic depression with limited response to treatment of fluoxetine 40 mg/d and quetiapine 100 mg/d for 3 months. After admission, we tapered fluoxetine gradually in 5 days because of its limited effect. However, delirious pictures developed 2 days after we stopped fluoxetine. Three days later, we added back fluoxetine 10 mg/d. Her delirious features gradually improved, and the clinical presentation turned into previous psychotic depression state. We gradually increased the medication to fluoxetine 60 mg/d and olanzapine 20 mg/d in the following 3 weeks. Her psychotic symptoms decreased, and there has been no delirious picture noted thereafter. Delirium associated with fluoxetine discontinuation is a much rarer complication in SSRI discontinuation syndrome. The symptoms of SSRI discontinuation syndrome may be attributable to a rapid decrease in serotonin availability. In general, the shorter the half-life of any medication, the greater the likelihood patients will experience discontinuation symptoms. Genetic vulnerability might be a potential factor to explain that SSRI discontinuation syndrome also occurred rapidly in people taking long-half-life fluoxetine. The genetic polymorphisms of both pharmacokinetic and pharmacodynamic pathways might be potentially associated with SSRI discontinuation syndrome.

Actor Bonds in Situations of Discontinuous Business Activities

DEFF Research Database (Denmark)

Skaates, Maria Anne

2000-01-01

Demand in many industrial buying situations, e.g. project purchases or procurement related to virtual organizations, is discontinuous. In situations of discontinuity, networks are often more of an ad hos informational and social nature, as strong activity and resource links are not present....... Furthermore the governance structure of markets characterized by discontinuous business activities is either that of the "socially constructed market" (Skaates, 2000) or that of the (socially constructed) network (Håkansson and Johanson, 1993). Additionally relationships and actor bonds vary substantially...

Fatigue analysis of a structure with welds considering metallurgical discontinuities

International Nuclear Information System (INIS)

Cabrillat, M.T.; Lejeail, Y.

1995-01-01

Within the frameworks of a creep-fatigue experimental program, called EVASION, thermo-mechanical tests were conducted on two mock-ups, the first one was fully machined and the second one welded and then machined (in order to eliminate geometrical discontinuities, thus only leaving metallurgical discontinuities). These two mock-ups were submitted to exactly the same loading history. Plastic analyses with a correct description of mechanical properties and fatigue strength of materials are conducted and compared with experimental results in order to highlight the influence of the weld. (author). 3 refs., 4 figs., 3 tabs

Passive noise control by enhancing aeroacoustic interference due to structural discontinuities in close proximity

Science.gov (United States)

Leung, R. C. K.; So, R. M. C.; Tang, S. K.; Wang, X. Q.

2011-07-01

In-duct devices are commonly installed in flow ducts for various flow management purposes. The structural construction of these devices indispensably creates disruption to smooth flow through duct passages so they exist as structural discontinuities in duct flow. The presence of these discontinuities provides additional possibility of noise generation. In real practice, in-duct devices do not exist alone in any duct system. Even though each in-duct device would generate its own noise, it might be possible that these devices could be properly arranged so as to strengthen the interference between individual noise; thus giving rise to an overall reduction of noise radiation in the in-duct far field. This concept of passive noise control is investigated by considering different configurations of two structural discontinuities of simple form (i.e., a cavity) in tandem in an unconfined flow and in opposing setting within a flow duct. It is known that noise generated by a cavity in unconfined domain (unconfined cavity) is strongly dependent on flow-resonant behavior within the cavity so the interference it produces is merely aeroacoustic. The objective of the present study is to verify the concept of passive noise reduction through enhancement of aeroacoustic interference due to two cavities by considering laminar flow only. A two-dimensional approach is adopted for the direct aeroacoustic calculations using a direct numerical simulation (DNS) technique. The position and geometries of the cavities and the Mach number are varied; the resultant aeroacoustic behavior and acoustic power are calculated. The numerical results are compared with a single cavity case to highlight the effect of introducing additional cavities to the aeroacoustic problem. Resonant flow oscillations occur when two unconfined cavities are very close and the associated acoustic field is very intense with no noise reduction possible. However, for duct aeroacoustics, it is found that a 7.9 db reduction

Identification of small-scale discontinuities based on dip-oriented gradient energy entropy coherence estimation

Science.gov (United States)

Peng, Da; Yin, Cheng

2017-09-01

Locating small-scale discontinuities is one of the most challenging geophysical tasks; these subtle geological features are significant since they are often associated with subsurface petroleum traps. Subtle faults, fractures, unconformities, reef textures, channel boundaries, thin-bed boundaries and other structural and stratigraphic discontinuities have subtle geological edges which may provide lateral variation in seismic expression. Among the different geophysical techniques available, 3D seismic discontinuity attributes are particularly useful for highlighting discontinuities in the seismic data. Traditional seismic discontinuity attributes are sensitive to noise and are not very appropriate for detecting small-scale discontinuities. Thus, we present a dip-oriented gradient energy entropy (DOGEE) coherence estimation method to detect subtle faults and structural features. The DOGEE coherence estimation method uses the gradient structure tensor (GST) algorithm to obtain local dip information and construct a gradient correlation matrix to calculate gradient energy entropy. The proposed DOGEE coherence estimation method is robust to noise, and also improves the clarity of fault edges. It is effective for small-scale discontinuity characterisation and interpretation.

Organising medication discontinuation

DEFF Research Database (Denmark)

Nixon, Michael; Kousgaard, Marius Brostrøm

2016-01-01

medication? Methods: Twenty four GPs were interviewed using a maximum variation sample strategy. Participant observations were done in three general practices, for one day each, totalling approximately 30 consultations. Results: The results show that different discontinuation cues (related to the type...... a medication, in agreement with the patients, from a professional perspective. Three research questions were examined in this study: when does medication discontinuation occur in general practice, how is discontinuing medication handled in the GP’s practice and how do GPs make decisions about discontinuing...

Early discontinuation

DEFF Research Database (Denmark)

Hansen, Dorte Gilså; Felde, Lina; Gichangi, Anthony

2007-01-01

prevalence and rate of early discontinuation of different drugs consisting of, in this study, lipid-lowering drugs, antihypertensive drugs, antidepressants, antidiabetics and drugs against osteoporosis. Material and methods This was a register study based on prescription data covering a 4-year period...... and consisting of 470,000 citizens. For each practice and group of drug, a 1-year prevalence for 2002 and the rate of early discontinuation among new users in 2002-2003 were estimated. Early discontinuation was defined as no prescriptions during the second half-year following the first prescription....... There was a positive association between the prevalence of prescribing for the specific drugs studied (antidepressants, antidiabetics, drugs against osteoporosis and lipid-lowering drugs) and early discontinuation (r = 0.29 -0.44), but not for anti-hypertensive drugs. The analysis of the association between prevalence...

Study on structural failure of RPV with geometric discontinuity under severe accident

Energy Technology Data Exchange (ETDEWEB)

Mao, J.F., E-mail: jianfeng-mao@163.com [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China); Zhu, J.W. [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Department of Mechanical and Electrical engineering, Huzhou Vocational & Technical College Huzhou, Zhejiang 313000 (China); Bao, S.Y., E-mail: bsy@zjut.edu.cn [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China); Luo, L.J. [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Gao, Z.L. [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China)

2016-10-15

Highlights: • The RPV failure is investigated in depth under severe accident. • The creep and plastic damage are the major contributor to RPV failure. • A elastic core is found at the midpoint of the highly-eroded region. • Weakest location has some ‘accommodating’ quality to prevent ductile tearing. • The internal pressure is critical for the determination of structural failure. - Abstract: A severe accident management strategy known as ‘in-vessel retention (IVR)’ is widely adopted in most of advanced nuclear power plants. The IVR mitigation is assumed to be able to arrest the degraded melting core and maintain the structural integrity of reactor pressure vessel (RPV) within a prescribed period of time. This traditional concept of IVR without consideration of internal pressure effect wasn’t challenged until the occurrence of Fukushima accident on 2011, which showed that the structural behavior had not been appropriately assessed, and a certain pressure (up to 8.0 MPa) still existed inside the RPV. Accordingly, the paper tries to address the related issue on whether lower head (LH) integrity can be maintained, when the LH is subjected to the thermal-mechanical loads created during such a severe accident. Because of the presence of the high temperature melt (∼1300 °C) on the inside of RPV, some local material is melted down to create a unique RPV with geometric discontinuity, while the outside of RPV submerged in cavity water will remain in nucleate boiling (at ∼150 °C). Therefore, the failure mechanisms of RPV can span a wide range of structural behaviors, such as melt-through, creep damage, plastic yielding as well as thermal expansion. Through meticulous investigation, it is found that the RPV failure is mainly caused by creep and plasticity, especially for the inside of highly-eroded region. The elastic core (or layer) is found to exist in the proximity of mid-section of the highly-eroded wall. However, the elastic core is squeezed into

Stress concentrations at structural discontinuities in active fault zones in the western United States: Implications for permeability and fluid flow in geothermal fields

Science.gov (United States)

Siler, Drew; Hinz, Nicholas H.; Faulds, James E.

2018-01-01

Slip can induce concentration of stresses at discontinuities along fault systems. These structural discontinuities, i.e., fault terminations, fault step-overs, intersections, bends, and other fault interaction areas, are known to host fluid flow in ore deposition systems, oil and gas reservoirs, and geothermal systems. We modeled stress transfer associated with slip on faults with Holocene-to-historic slip histories at the Salt Wells and Bradys geothermal systems in western Nevada, United States. Results show discrete locations of stress perturbation within discontinuities along these fault systems. Well field data, surface geothermal manifestations, and subsurface temperature data, each a proxy for modern fluid circulation in the fields, indicate that geothermal fluid flow is focused in these same areas where stresses are most highly perturbed. These results suggest that submeter- to meter-scale slip on these fault systems generates stress perturbations that are sufficiently large to promote slip on an array of secondary structures spanning the footprint of the modern geothermal activity. Slip on these secondary faults and fractures generates permeability through kinematic deformation and allows for transmission of fluids. Still, mineralization is expected to seal permeability along faults and fractures over time scales that are generally shorter than either earthquake recurrence intervals or the estimated life span of geothermal fields. This suggests that though stress perturbations resulting from fault slip are broadly important for defining the location and spatial extent of enhanced permeability at structural discontinuities, continual generation and maintenance of flow conduits throughout these areas are probably dependent on the deformation mechanism(s) affecting individual structures.

Discrete modeling of multiple discontinuities in rock mass using XFEM

OpenAIRE

Das, Kamal C.; Ausas, Roberto Federico; Carol, Ignacio; Rodrigues, Eduardo; Sandeep, Sandra; Vargas, P. E.; Gonzalez, Nubia Aurora; Segura, Josep María; Lakshmikantha, Ramasesha Mookanahallipatna; Mello,, U.

2017-01-01

Modeling of discontinuities (fractures and fault surfaces) is of major importance to assess the geomechanical behavior of oil and gas reservoirs, especially for tight and unconventional reservoirs. Numerical analysis of discrete discontinuities traditionally has been studied using interface element concepts, however more recently there are attempts to use extended finite element method (XFEM). The development of an XFEM tool for geo-mechanical fractures/faults modeling has significant industr...

Excursions in fluvial (dis)continuity

Science.gov (United States)

Grant, Gordon E.; O'Connor, James E.; Safran, Elizabeth

2017-01-01

: punctuated episodes of cutting and filling, discretization of landscapes into hierarchies of structure and control, the work of extreme events. Orderly and progressive evolution towards a steady or ideal state is replaced by chaotic episodes of disturbance and recovery. Recent developments in the field of geomorphology suggest that we may be on the cusp of a new paradigm that recognizes that both continuous and discontinuous processes and mechanisms play a role in fluvial processes and landscape evolution with neither holding sway over the other and both needed to see rivers as they are.

Strain concentration at structural discontinuities and its quantification by elastic follow-up parameter

International Nuclear Information System (INIS)

Kasahara, Naoto; Takasho, Hideki

1998-12-01

Elevated temperature structural design codes pay attention to strain concentration at structural discontinuities due to creep and plasticity, since it causes to enlarge creep-fatigue damage of material. One of the difficulties to predict strain concentration is its dependency on loading, constitutive equations, and relaxation time. This study investigated fundamental mechanism of strain concentration and its main factors. It was clarified that strain concentration was caused from strain redistribution between elastic and inelastic regions, which can be quantified by the elastic follow-up parameter. As a function of inelastic strain, the elastic follow-up parameter can describe variation of strain concentration during incremental loading and relaxation process, caused by transition of strain distribution from peak strain concentration to secondary stress redistribution. Structures have their own elastic follow-up characteristics as a function of inelastic strain, which is insensitive to constitutive equations. It means that application of inelastic analysis is not difficult to obtain elastic follow-up characteristics. (author)

Rotational discontinuities in anisotropic plasmas

International Nuclear Information System (INIS)

Omidi, N.

1992-01-01

The kinetic structure of rotational discontinuities (RDs) in anisotropic plasmas with T perpendicular /T parallel > 1 is investigated by using a one-dimensional electromagnetic hybrid code. To form the RD, a new approach is used where the plasma is injected from one boundary and reflected from the other, resulting in the generation of a traveling fast shock and an RD. Unlike the previously used methods, no a priori assumptions are made regarding the initial structure (i.e. width or sense of rotation) of the rotational discontinuity. The results show that across the RD both the magnetic field strength and direction, as well as the plasma density change. Given that such a change can also be associated with an intermediate shock, the Rankine-Hugoniot relations are used to confirm that the observed structures are indeed RDs. It is found that the thickness of RDs is a few ion inertial lengths and is independent of the rotation angle. Also, the preferred sense of rotation is in the electron sense; however, RDs with a rotation angle larger than 180 degree are found to be unstable, changing their rotation to a stable ion sense

hpGEM -- A software framework for discontinuous Galerkin finite element methods

NARCIS (Netherlands)

Pesch, L.; Bell, A.; Sollie, W.E.H.; Ambati, V.R.; Bokhove, Onno; van der Vegt, Jacobus J.W.

2006-01-01

hpGEM, a novel framework for the implementation of discontinuous Galerkin finite element methods, is described. We present structures and methods that are common for many (discontinuous) finite element methods and show how we have implemented the components as an object-oriented framework. This

Low-Dose Aspirin Discontinuation and Risk of Cardiovascular Events: A Swedish Nationwide, Population-Based Cohort Study.

Science.gov (United States)

Sundström, Johan; Hedberg, Jakob; Thuresson, Marcus; Aarskog, Pernilla; Johannesen, Kasper Munk; Oldgren, Jonas

2017-09-26

There are increasing concerns about risks associated with aspirin discontinuation in the absence of major surgery or bleeding. We investigated whether long-term low-dose aspirin discontinuation and treatment gaps increase the risk of cardiovascular events. We performed a cohort study of 601 527 users of low-dose aspirin for primary or secondary prevention in the Swedish prescription register between 2005 and 2009 who were >40 years of age, were free from previous cancer, and had ≥80% adherence during the first observed year of treatment. Cardiovascular events were identified with the Swedish inpatient and cause-of-death registers. The first 3 months after a major bleeding or surgical procedure were excluded from the time at risk. During a median of 3.0 years of follow-up, 62 690 cardiovascular events occurred. Patients who discontinued aspirin had a higher rate of cardiovascular events than those who continued (multivariable-adjusted hazard ratio, 1.37; 95% confidence interval, 1.34-1.41), corresponding to an additional cardiovascular event observed per year in 1 of every 74 patients who discontinue aspirin. The risk increased shortly after discontinuation and did not appear to diminish over time. In long-term users, discontinuation of low-dose aspirin in the absence of major surgery or bleeding was associated with a >30% increased risk of cardiovascular events. Adherence to low-dose aspirin treatment in the absence of major surgery or bleeding is likely an important treatment goal. © 2017 American Heart Association, Inc.

Determination of the 8° discontinuity beneath the major tectonic units of Central Europe from regional seismicity in Europe and northern Africa

Science.gov (United States)

Nita, B.; Perchuc, E.; Thybo, H.; Maguire, P.; Denton, P.

2004-12-01

We evaluate the existence and the depth of the '8° discontinuity' beneath the Alpine orogen using the natural seismicity of Europe and northern Africa as well as events induced by mining activity. For this analysis, the regional events (1) must have epicenters further than 1000 km from the structure being imaged, and (2) the magnitude of body waves must be higher than 4.0 to obtain a favourable signal to noise ratio. The events satisfying the above conditions have epicentres in Algeria, Spain, Bulgaria, Greece and in the Lubin Copper Basin in Poland. The last region is characterised by high seismicity resulting from mining activity. We base our analysis on P-wave traveltime residuals compared to the general iasp91 model. The 8° discontinuity seems to be attributed to the observed P-wave traveltime delays at epicentral distances around 800 km. The analysis of events from the Lubin Coper Basin and the events from other regions mentioned above, gives P-wave delays of 3 s at the Alpine stations in comparison with stations in the Variscan areas to further north. We attribute this variation in travel time to the difference between 'fast' and 'slow' uppermost mantle structures in Europe.

Organising medication discontinuation: a qualitative study exploring the views of general practitioners toward discontinuing statins.

Science.gov (United States)

Nixon, Michael; Kousgaard, Marius Brostrøm

2016-07-07

Discontinuing medications is a complex decision making process and an important medical practice. It is a tool in reducing polypharmacy, reducing health system expenditure and improving patient quality of life. Few studies have looked at how general practitioners (GPs) discontinue a medication, in agreement with the patients, from a professional perspective. Three research questions were examined in this study: when does medication discontinuation occur in general practice, how is discontinuing medication handled in the GP's practice and how do GPs make decisions about discontinuing medication? Twenty four GPs were interviewed using a maximum variation sample strategy. Participant observations were done in three general practices, for one day each, totalling approximately 30 consultations. The results show that different discontinuation cues (related to the type of consultation, medical records and the patient) create situations of dissonance that can lead to the GP considering the option of discontinuation. We also show that there is a lot of ambiguity in situations of discontinuing and that some GPs trialled discontinuing as means of generating more information that could be used to deal with the ambiguity. We conclude that the practice of discontinuation should be conceptualised as a continually evaluative process and one that requires sustained reflection through a culture of systematically scheduled check-ups, routinely eliciting the patient's experience of taking drugs and trialling discontinuation. Some policy recommendations are offered including supporting GPs with lists or handbooks that directly address discontinuation and by developing more person centred clinical guidelines that discuss discontinuation more explicitly.

Quantitative Estimation of Transmitted and Reflected Lamb Waves at Discontinuity

International Nuclear Information System (INIS)

Lim, Hyung Jin; Sohn, Hoon

2010-01-01

For the application of Lamb wave to structural health monitoring(SHM), understanding its physical characteristic and interaction between Lamb wave and defect of the host structure is an important issue. In this study, reflected, transmitted and mode converted Lamb waves at discontinuity of a plate structure were simulated and the amplitude ratios are calculated theoretically using Modal decomposition method. The predicted results were verified comparing with finite element method(FEM) and experimental results simulating attached PZTs. The result shows that the theoretical prediction is close to the FEM and the experimental verification. Moreover, quantitative estimation method was suggested using amplitude ratio of Lamb wave at discontinuity

Soliton shock wave fronts and self-similar discontinuities in dispersion hydrodynamics

International Nuclear Information System (INIS)

Gurevich, A.V.; Meshcherkin, A.P.

1987-01-01

Nonlinear flows in nondissipative dispersion hydrodynamics are examined. It is demonstrated that in order to describe such flows it is necessary to incorporate a new concept: a special discontinuity called a ''self-similar'' discontinuity consisting of a nondissipative shock wave and a powerful slow wave discontinuity in regular hydrodynamics. The ''self similar discontinuity'' expands linearly over time. It is demonstrated that this concept may be introduced in a solution to Euler equations. The boundary conditions of the ''self similar discontinuity'' that allow closure of Euler equations for dispersion hydrodynamics are formulated, i.e., those that replace the shock adiabatic curve of standard dissipative hydrodynamics. The structure of the soliton front and of the trailing edge of the shock wave is investigated. A classification and complete solution are given to the problem of the decay of random initial discontinuities in the hydrodynamics of highly nonisothermic plasma. A solution is derived to the problem of the decay of initial discontinuities in the hydrodynamics of magnetized plasma. It is demonstrated that in this plasma, a feature of current density arises at the point of soliton inversion

Fitness in animals correlates with proximity to discontinuities in body mass distributions.

Science.gov (United States)

Angeler, David G.; Allen, Craig R.; Vila-Gispert, Anna; Almeida, David

2014-01-01

Discontinuous structure in landscapes may cause discontinuous, aggregated species body-mass patterns, reflecting the scales of structure available to animal communities within a landscape. Empirical analyses have shown that the location of species within body mass aggregations, which reflect this scale-specific organization, is non-random with regard to several ecological phenomena, including species extinctions. The propensity of declining species to have body masses proximate to discontinuities suggests that transition zones between scaling regimes ultimately decreases the ecological fitness for some species. We test this proposition using vulnerable and unthreatened fish species in Mediterranean streams with differing levels of human impact. We show that the proximity to discontinuities in body mass aggregations (“distance-to-edge”) of more vs. less fit individuals within vulnerable and unthreatened populations differs. Specifically, regression analysis between the scaled mass index, a proxy of animal fitness, and distance-to-edge reveals negative and positive relationships for vulnerable and unthreatened species, respectively. That is, fitness is higher close to discontinuities in vulnerable populations and toward the center of body mass aggregation groups in unthreatened populations. Our results demonstrate the suitability of the discontinuity framework for scrutinizing non-random patterns of environmental impact in populations. Further exploration of the usefulness of this method across other ecosystems and organism groups is warranted.

Second tyrosine kinase inhibitor discontinuation attempt in patients with chronic myeloid leukemia.

Science.gov (United States)

Legros, Laurence; Nicolini, Franck E; Etienne, Gabriel; Rousselot, Philippe; Rea, Delphine; Giraudier, Stéphane; Guerci-Bresler, Agnès; Huguet, Françoise; Gardembas, Martine; Escoffre, Martine; Ianotto, Jean-Christophe; Noël, Marie-Pierre; Varet, Bruno R; Pagliardini, Thomas; Touitou, Irit; Morisset, Stéphane; Mahon, Francois-Xavier

2017-11-15

Several studies have demonstrated that approximately one-half of patients with chronic myeloid leukemia (CML) who receive treatment with tyrosine kinase inhibitors (TKIs) and achieve and maintain a deep molecular response (DMR) are able to successfully discontinue therapy. In patients who have a molecular relapse, a DMR is rapidly regained upon treatment re-initiation. The authors report the results from RE-STIM, a French observational, multicenter study that evaluated treatment-free remission (TFR) in 70 patients who re-attempted TKI discontinuation after a first unsuccessful attempt. After the second TKI discontinuation attempt, the trigger for treatment re-introduction was the loss of a major molecular response in all patients. The median follow-up was 38.3 months (range, 4.7-117 months), and 45 patients (64.3%) lost a major molecular response after a median time off therapy of 5.3 months (range, 2-42 months). TFR rates at 12, 24, and 36 months were 48% (95% confidence interval [CI], 37.6%-61.5%), 42% (95% CI, 31.5%-55.4%), and 35% (95% CI, 24.4%-49.4%), respectively. No progression toward advanced-phase CML occurred, and no efficacy issue was observed upon TKI re-introduction. In univariate analysis, the speed of molecular relapse after the first TKI discontinuation attempt was the only factor significantly associated with outcome. The TFR rate at 24 months was 72% (95% CI, 48.8%-100%) in patients who remained in DMR within the first 3 months after the first TKI discontinuation and 36% (95% CI, 25.8%-51.3%) for others. This study is the first to demonstrate that a second TKI discontinuation attempt is safe and that a first failed attempt at discontinuing TKI does not preclude a second successful attempt. Cancer 2017;123:4403-10. © 2017 American Cancer Society. © 2017 American Cancer Society.

System dynamics with interaction discontinuity

CERN Document Server

Luo, Albert C J

2015-01-01

This book describes system dynamics with discontinuity caused by system interactions and presents the theory of flow singularity and switchability at the boundary in discontinuous dynamical systems. Based on such a theory, the authors address dynamics and motion mechanism of engineering discontinuous systems due to interaction. Stability and bifurcations of fixed points in nonlinear discrete dynamical systems are presented, and mapping dynamics are developed for analytical predictions of periodic motions in engineering discontinuous dynamical systems. Ultimately, the book provides an alternative way to discuss the periodic and chaotic behaviors in discontinuous dynamical systems.

Discontinuation of anti-VEGF cancer therapy promotes metastasis through a liver revascularization mechanism

DEFF Research Database (Denmark)

Yang, Yunlong; Zhang, Yin; Iwamoto, Hideki

2016-01-01

The impact of discontinuation of anti-VEGF cancer therapy in promoting cancer metastasis is unknown. Here we show discontinuation of anti-VEGF treatment creates a time-window of profound structural changes of liver sinusoidal vasculatures, exhibiting hyper-permeability and enlarged open-pore size...

On the stability of rotational discontinuities

International Nuclear Information System (INIS)

Richter, P.; Scholer, M.

1989-01-01

The stability of symmetric rotational discontinuities in which the magnetic field rotates by 180 degree is investigated by means of a one-dimensional self-consistent hybrid code. Rotational discontinuities with an angle Θ > 45 degree between the discontinuity normal direction and the upstream magnetic field are found to be relatively stable. The discontinuity normal is in the x direction and the initial magnetic field has finite y component only in the transition region. In the case of the ion (left-handed) sense of rotation of the tangential magnetic field, the transition region does not broaden with time. In the case of the electron (right-handed) sense of rotation, a damped wavetrain builds up in the B y component downstream of the rotational discontinuity and the discontinuity broadens with time. Rotational discontinuities with smaller angles, Θ, are unstable. Examples for a rotational discontinuity with Θ = 30 degree and the electron sense of rotation as well as a rotational discontinuity with Θ = 15 degree and the ion sense of rotation show that these discontinuities into waves. These waves travel approximately with Alfven velocity in the upstream direction and are therefore phase standing in the simulation system. The magnetic hodograms of these disintegrated discontinuities are S-shaped. The upstream portion of the hodogram is always right-handed; the downstream portion is always left-handed

Longitudinal coupling impedance of step discontinuities in a circular beam tube

International Nuclear Information System (INIS)

Hahn, H.; Zatz, S.

1979-01-01

The longitudinal coupling impedance presented by a single wall discontinuity to the circulating beam in a circular accelerator or storage ring is usually analyzed by considering a developed periodic structure. However, the typical parameters are often such that it becomes adequate to treat the discontinuity as a nonperiodic problem. Using modal field matching methods, solutions were derived for the cases of a single as well as a double-step discontinuity in a circular beam tube. Numerical results are presented in this paper and the typical behavior at low frequency, at reasonance, and above cut-off is discussed

Efem vs. XFEM: a comparative study for modeling strong discontinuity in geomechanics

OpenAIRE

Das, Kamal C.; Ausas, Roberto Federico; Segura Segarra, José María; Narang, Ankur; Rodrigues, Eduardo; Carol, Ignacio; Lakshmikantha, Ramasesha Mookanahallipatna; Mello,, U.

2015-01-01

Modeling of big faults or weak planes of strong and weak discontinuities is of major importance to assess the Geomechanical behaviour of mining/civil tunnel, reservoirs etc. For modelling fractures in Geomechanics, prior art has been limited to Interface Elements which suffer from numerical instability and where faults are required to be aligned with element edges. In this paper, we consider comparative study on finite elements for capturing strong discontinuities by means of elemental (EFEM)...

Occupy the Financial Niche – Saturation and Crisis (discontinuous decisions

Directory of Open Access Journals (Sweden)

Ionut PURICA

2014-09-01

Full Text Available The model presented is proposing an approach that could verify the nonlinear behaviour during a crisis, such that to quantify and predict potential discontinuous behaviour. In this case, the crisis behaviour associated with financial funds reallocation among various credit instruments, described as memes with the sense of Dawkins, is shown to be of discontinuous nature stemming from a logistic penetration in the financial behaviour niche. Actually the logistic penetration is typical in creating cyclic behaviour of economic structures as shown by Marchetti and others from IIASA. A Fokker-Planck equation description results in a stationary solution having a bifurcation like solution with evolution trajectories on a ‘cusp’ type catastrophe that may describe discontinuous decision behaviour

Multi-Objective Patch Optimization with Integrated Kinematic Draping Simulation for Continuous–Discontinuous Fiber-Reinforced Composite Structures

Directory of Open Access Journals (Sweden)

Benedikt Fengler

2018-03-01

Full Text Available Discontinuous fiber-reinforced polymers (DiCoFRP in combination with local continuous fiber reinforced polymers (CoFRP provide both a high design freedom and high weight-specific mechanical properties. For the optimization of CoFRP patches on complexly shaped DiCoFRP structures, an optimization strategy is needed which considers manufacturing constraints during the optimization procedure. Therefore, a genetic algorithm is combined with a kinematic draping simulation. To determine the optimal patch position with regard to structural performance and overall material consumption, a multi-objective optimization strategy is used. The resulting Pareto front and a corresponding heat-map of the patch position are useful tools for the design engineer to choose the right amount of reinforcement. The proposed patch optimization procedure is applied to two example structures and the effect of different optimization setups is demonstrated.

Grades, Gender, and Encouragement: A Regression Discontinuity Analysis

Science.gov (United States)

Owen, Ann L.

2010-01-01

The author employs a regression discontinuity design to provide direct evidence on the effects of grades earned in economics principles classes on the decision to major in economics and finds a differential effect for male and female students. Specifically, for female students, receiving an A for a final grade in the first economics class is…

Discontinuous Petrov–Galerkin method with optimal test functions for thin-body problems in solid mechanics

KAUST Repository

Niemi, Antti H.; Bramwell, Jamie A.; Demkowicz, Leszek F.

2011-01-01

We study the applicability of the discontinuous Petrov-Galerkin (DPG) variational framework for thin-body problems in structural mechanics. Our numerical approach is based on discontinuous piecewise polynomial finite element spaces for the trial

Bayesian inversion of surface wave data for discontinuities and velocity structure in the upper mantle using Neural Networks. Geologica Ultraiectina (287)

NARCIS (Netherlands)

Meier, U.

2008-01-01

We present a neural network approach to invert surface wave data for discontinuities and velocity structure in the upper mantle. We show how such a neural network can be trained on a set of random samples to give a continuous approximation to the inverse relation in a compact and computationally

Rates of IUCD discontinuation and its associated factors among the clients of a social franchising network in Pakistan.

Science.gov (United States)

Azmat, Syed Khurram; Shaikh, Babar Tasneem; Hameed, Waqas; Bilgrami, Mohsina; Mustafa, Ghulam; Ali, Muhammad; Ishaque, Muhammad; Hussain, Wajahat; Ahmed, Aftab

2012-03-29

Modern Intrauterine contraceptive device (IUCD) is very safe, highly effective reversible and inexpensive family planning method which offers 5-10 years of protection against pregnancy. The contraceptive use in Pakistan has been merely 30% for over a decade with IUCD being the least used method. Higher discontinuation rates are documented in developing countries; however no such data is available for Pakistan. Marie Stopes Society (MSS) established a social franchise outlets network branded as 'SURAJ' (Sun) in Pakistan to provide quality family planning services. This study attempts to determine IUCD discontinuation rates and its associated risk factors. Using a semi-structured questionnaire, a cross-sectional study was conducted with 3000 clients who availed IUCD services from Suraj provider 6, 12 and 24 month back,. Data were analyzed in SPSS 17.0; adjusted prevalence ratios were calculated to see associations between discontinuation and its risk factors. We found that 22.7% of the IUCD acceptors experienced some health problem; while the overall discontinuation rate was 18.9% with average time of usage of 7.4 (SD ± 5.8) months before discontinuation. Half of them showed health concerns (49.8%); of which a majority (70.2%) returned to Suraj provider for IUCD removal. Women living in Punjab, residing at a travelling time of 30-60 minutes and no previous use of contraceptive are more likely to discontinue IUCD. However, among total women 81.7% still expressed willingness to avail IUCD services from Suraj provider in future, if needed. The findings suggest a need for training the providers and field workers to prevent early discontinuation of IUCD among the Suraj clients and by addressing the health concerns through proper counseling, continued follow-up and immediate medical aid/referral in case of complications.

Rates of IUCD discontinuation and its associated factors among the clients of a social franchising network in Pakistan

Science.gov (United States)

2012-01-01

Background Modern Intrauterine contraceptive device (IUCD) is very safe, highly effective reversible and inexpensive family planning method which offers 5-10 years of protection against pregnancy. The contraceptive use in Pakistan has been merely 30% for over a decade with IUCD being the least used method. Higher discontinuation rates are documented in developing countries; however no such data is available for Pakistan. Marie Stopes Society (MSS) established a social franchise outlets network branded as 'SURAJ' (Sun) in Pakistan to provide quality family planning services. This study attempts to determine IUCD discontinuation rates and its associated risk factors. Using a semi-structured questionnaire, a cross-sectional study was conducted with 3000 clients who availed IUCD services from Suraj provider 6, 12 and 24 month back,. Data were analyzed in SPSS 17.0; adjusted prevalence ratios were calculated to see associations between discontinuation and its risk factors. Case presentation We found that 22.7% of the IUCD acceptors experienced some health problem; while the overall discontinuation rate was 18.9% with average time of usage of 7.4 (SD ± 5.8) months before discontinuation. Half of them showed health concerns (49.8%); of which a majority (70.2%) returned to Suraj provider for IUCD removal. Women living in Punjab, residing at a travelling time of 30-60 minutes and no previous use of contraceptive are more likely to discontinue IUCD. However, among total women 81.7% still expressed willingness to avail IUCD services from Suraj provider in future, if needed. Conclusion The findings suggest a need for training the providers and field workers to prevent early discontinuation of IUCD among the Suraj clients and by addressing the health concerns through proper counseling, continued follow-up and immediate medical aid/referral in case of complications. PMID:22458444

Rates of IUCD discontinuation and its associated factors among the clients of a social franchising network in Pakistan

Directory of Open Access Journals (Sweden)

Azmat Syed

2012-03-01

Full Text Available Abstract Background Modern Intrauterine contraceptive device (IUCD is very safe, highly effective reversible and inexpensive family planning method which offers 5-10 years of protection against pregnancy. The contraceptive use in Pakistan has been merely 30% for over a decade with IUCD being the least used method. Higher discontinuation rates are documented in developing countries; however no such data is available for Pakistan. Marie Stopes Society (MSS established a social franchise outlets network branded as 'SURAJ' (Sun in Pakistan to provide quality family planning services. This study attempts to determine IUCD discontinuation rates and its associated risk factors. Using a semi-structured questionnaire, a cross-sectional study was conducted with 3000 clients who availed IUCD services from Suraj provider 6, 12 and 24 month back,. Data were analyzed in SPSS 17.0; adjusted prevalence ratios were calculated to see associations between discontinuation and its risk factors. Case presentation We found that 22.7% of the IUCD acceptors experienced some health problem; while the overall discontinuation rate was 18.9% with average time of usage of 7.4 (SD ± 5.8 months before discontinuation. Half of them showed health concerns (49.8%; of which a majority (70.2% returned to Suraj provider for IUCD removal. Women living in Punjab, residing at a travelling time of 30-60 minutes and no previous use of contraceptive are more likely to discontinue IUCD. However, among total women 81.7% still expressed willingness to avail IUCD services from Suraj provider in future, if needed. Conclusion The findings suggest a need for training the providers and field workers to prevent early discontinuation of IUCD among the Suraj clients and by addressing the health concerns through proper counseling, continued follow-up and immediate medical aid/referral in case of complications.

Numerical simulation of SPH for dynamics effect of multilayer discontinuous structure irradiated by impulse X-ray

International Nuclear Information System (INIS)

Xu Binbin; Tang Wenhui; Ran Xianwen; Xu Zhihong; Chen Hua

2012-01-01

When high energy X-ray irradiates material, it will cause energy deposition in materials, and generates thermal shock wave. At present, finite difference method is used to the numerical simulation of thermal shock usually, but if considering the inter-space between the multilayer materials, the difference method will be more difficult. This paper used the SPH method to simulate multilayer discontinuous structure irradiated by high energy X-ray, and the results show that the gap between the materials of each layer has a certain influence on the thermal shock wave intensity, but doesn't have any affect to gasification impulse. (authors)

Discontinuity model for internal transport barrier formation in reversed magnetic shear plasmas

International Nuclear Information System (INIS)

Kishimoto, Y.; Kim, J-Y.; Horton, W.; Tajima, T.; LeBrun, M.J.

2001-01-01

To aid in understanding the internal transport barrier (ITB) being formed in reversed magnetic shear experiments, in addition to the well known shear flow effect, we point out an important nonlocal effect and/or finite size effect which comes from the complex behavior of the nonlocal mode over a finite radial region around the minimum q(safety factor)-surface. The nonlocal mode changes its structure depending on the sign of the magnetic shear and due to this fact, the nonlocal modes are weakly excited across the q min -surface. This leads to a discontinuity or gap which disconnects the phase relation in the global wave structure across the q min -surface. Once such a discontinuity (or gap) is formed, transport suppression occurs and therefore a transport barrier can be expected near the q min -surface. We confirm the existence of this discontinuity using a toroidal particle simulation. (author)

Reasons for discontinuation of contraceptive methods among couples with different family size and educational status.

Science.gov (United States)

Rizvi, Farwa; Irfan, Ghazia

2012-01-01

High rates of contraceptive discontinuation for reasons other than the desire for pregnancy are a public health concern because of their association with negative reproductive health outcomes. The objective of this study was to determine reasons for discontinuation of contraceptive methods among couples with different family size and educational status. This cross-sectional study was carried out at the Obstetrics/Gynaecology Out-Patient Department of Pakistan Institute of Medical Sciences, Islamabad from April-September 2012. Patients (241) were selected by consecutive sampling after informed written consent and acquiring approval of Ethical Committee. The survey interview tool was a semi-structured questionnaire. Majority (68%) of women belonged to urban, and the rest were from rural areas. Mean age of these women was 29.43 +/- 5.384 year. Reasons for discontinuation of contraceptives included fear of injectable contraceptives (2.9%), contraceptive failure/pregnancy (7.46%), desire to become pregnant (63.48%), husband away at job (2.49%), health concerns/side effects (16.18%), affordability (0.83%), inconvenient to use (1.24%), acceptability (0.83%) and accessibility/lack of information (4.56%). Association of different reasons of discontinuation (chi square test) with the family size (actual number of children) was significant (p = 0.019) but was not significant with husband's or wife's educational status (p = 0.33 and 0.285 respectively). Keeping in mind the complex socioeconomic conditions in our country, Family planning programmers and stake holders need to identify women who strongly want to avoid a pregnancy and finding ways to help the couples successfully initiate and maintain appropriate contraceptive use.

General Practitioners’ Decisions about Discontinuation of Medication

DEFF Research Database (Denmark)

Nixon, Michael Simon; Vendelø, Morten Thanning

2016-01-01

insights about decision making when discontinuing medication. It also offers one of the first examinations of how the institutional context embedding GPs influences their decisions about discontinuation. For policymakers interested in the discontinuation of medication, the findings suggest that de......Purpose – The purpose of this paper is to investigate how general practitioners’ (GPs) decisions about discontinuation of medication are influenced by their institutional context. Design/methodology/approach – In total, 24 GPs were interviewed, three practices were observed and documents were...... a weak frame for discontinuation. Three reasons for this are identified: the guidelines provide dominating triggers for prescribing, they provide weak priming for discontinuation as an option, and they underscore a cognitive constraint against discontinuation. Originality/value – The analysis offers new...

Factors affecting IUCD discontinuation in Nepal

DEFF Research Database (Denmark)

Thapa, Subash; Paudel, Ishwari Sharma; Bhattarai, Sailesh

2015-01-01

Information related to contraception discontinuation, especially in the context of Nepal is very limited. A nested case-control study was carried out to determine the factors affecting discontinuation of intrauterine contraceptive devices (IUCDs). A total of 115 cases (IUCD discontinuers) and 115...

Long-term outcomes for patients with chronic lymphocytic leukemia who discontinue ibrutinib.

Science.gov (United States)

Jain, Preetesh; Thompson, Philip A; Keating, Michael; Estrov, Zeev; Ferrajoli, Alessandra; Jain, Nitin; Kantarjian, Hagop; Burger, Jan A; O'Brien, Susan; Wierda, William G

2017-06-15

Ibrutinib is a Bruton tyrosine kinase inhibitor and is approved for the treatment of patients with chronic lymphocytic leukemia (CLL) in frontline and relapsed/refractory settings. The authors previously reported poor outcomes for patients who discontinued ibrutinib; however, long-term outcomes were not reported. Data from 320 patients who received ibrutinib on clinical studies between 2010 and 2015 at The University of Texas MD Anderson Cancer Center were retrospectively analyzed. Long-term outcomes among patients with CLL after they discontinued ibrutinib were analyzed. Ninety of 320 patients (28%) who were treated on ibrutinib-based regimens discontinued ibrutinib. Of these, 80 had relapsed/refractory disease, and 10 were treatment-naive. The median time to discontinuation was 15 months (range, 1.2-54 months). After a median follow-up of 38 months after starting ibrutinib, 40 patients (44%) remained alive. Major reasons for ibrutinib discontinuation were intolerance (n = 29; 32%), miscellaneous (n = 28; 31%), progression (n = 19; 21%), and Richter transformation (RT) (n = 9; 10%). The median survival according to the reason for discontinuation was 33 months for ibrutinib intolerance, 11 months for miscellaneous causes, 16 months for progressive CLL, and 2 months for RT. Among the 19 patients who had progressive CLL, 42% responded to subsequent therapy. Ibrutinib discontinuation was observed during therapy. Patients with CLL who had disease transformation had especially poor outcomes, whereas those who developed progressive disease during ibrutinib therapy had a median survival of ibrutinib therapy is of critical importance. Cancer 2017;123:2268-2273. © 2017 American Cancer Society. © 2017 American Cancer Society.

THE FORMATION OF ROTATIONAL DISCONTINUITIES IN COMPRESSIVE THREE-DIMENSIONAL MHD TURBULENCE

Energy Technology Data Exchange (ETDEWEB)

Yang, Liping; Feng, Xueshang [SIGMA Weather Group, State Key Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, 100190, Beijing (China); Zhang, Lei; He, Jiansen; Tu, Chuanyi; Wang, Linghua; Wang, Xin [School of Earth and Space Sciences, Peking University, 100871 Beijing (China); Marsch, Eckart [Institute for Experimental and Applied Physics, Christian Albrechts University at Kiel, D-24118 Kiel (Germany); Zhang, Shaohua, E-mail: jshept@gmail.com [Center of Spacecraft Assembly Integration and Test, China Academy of Space Technology, Beijing 100094 (China)

2015-08-20

Measurements of solar wind turbulence reveal the ubiquity of discontinuities. In this study we investigate how the discontinuities, especially rotational discontinuities (RDs), are formed in MHD turbulence. In a simulation of the decaying compressive three-dimensional (3D) MHD turbulence with an imposed uniform background magnetic field, we detect RDs with sharp field rotations and little variations of magnetic field intensity, as well as mass density. At the same time, in the de Hoffman–Teller frame, the plasma velocity is nearly in agreement with the Alfvén speed, and is field-aligned on both sides of the discontinuity. We take one of the identified RDs to analyze its 3D structure and temporal evolution in detail. By checking the magnetic field and plasma parameters, we find that the identified RD evolves from the steepening of the Alfvén wave with moderate amplitude, and that steepening is caused by the nonuniformity of the Alfvén speed in the ambient turbulence.

27 CFR 555.128 - Discontinuance of business.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Discontinuance of business... Discontinuance of business. Where an explosive materials business or operations is discontinued and succeeded by... such facts and shall be delivered to the successor. Where discontinuance of the business or operations...

27 CFR 478.57 - Discontinuance of business.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Discontinuance of business... Licenses § 478.57 Discontinuance of business. (a) Where a firearm or ammunition business is either discontinued or succeeded by a new owner, the owner of the business discontinued or succeeded shall within 30...

Evaluation of energy absorption performance of steel square profiles with circular discontinuities

Directory of Open Access Journals (Sweden)

Dariusz Szwedowicz

Full Text Available This article details the experimental and numerical results on the energy absorption performance of square tubular profile with circular discontinuities drilled at lengthwise in the structure. A straight profile pattern was utilized to compare the absorption of energy between the ones with discontinuities under quasi-static loads. The collapse mode and energy absorption conditions were modified by circular holes. The holes were drilled symmetrically in two walls and located in three different positions along of profile length. The results showed a better performance on energy absorption for the circular discontinuities located in middle height. With respect to a profile without holes, a maximum increase of 7% in energy absorption capacity was obtained experimentally. Also, the numerical simulation confirmed that the implementation of circular discontinuities can reduce the peak load (Pmax by 10%. A present analysis has been conducted to compare numerical results obtained by means of the finite element method with the experimental data captured by using the testing machine. Finally the discrete model of the tube with and without geometrical discontinuities presents very good agreements with the experimental results.

Management applications of discontinuity theory

Science.gov (United States)

Angeler, David G.; Allen, Craig R.; Barichievy, Chris; Eason, Tarsha; Garmestani, Ahjond S.; Graham, Nicholas A.J.; Granholm, Dean; Gunderson, Lance H.; Knutson, Melinda; Nash, Kirsty L.; Nelson, R. John; Nystrom, Magnus; Spanbauer, Trisha; Stow, Craig A.; Sundstrom, Shana M.

2015-01-01

Human impacts on the environment are multifaceted and can occur across distinct spatiotemporal scales. Ecological responses to environmental change are therefore difficult to predict, and entail large degrees of uncertainty. Such uncertainty requires robust tools for management to sustain ecosystem goods and services and maintain resilient ecosystems.We propose an approach based on discontinuity theory that accounts for patterns and processes at distinct spatial and temporal scales, an inherent property of ecological systems. Discontinuity theory has not been applied in natural resource management and could therefore improve ecosystem management because it explicitly accounts for ecological complexity.Synthesis and applications. We highlight the application of discontinuity approaches for meeting management goals. Specifically, discontinuity approaches have significant potential to measure and thus understand the resilience of ecosystems, to objectively identify critical scales of space and time in ecological systems at which human impact might be most severe, to provide warning indicators of regime change, to help predict and understand biological invasions and extinctions and to focus monitoring efforts. Discontinuity theory can complement current approaches, providing a broader paradigm for ecological management and conservation.

Numerical simulation of the interaction between a nonlinear elastic structure and compressible flow by the discontinuous Galerkin method

Czech Academy of Sciences Publication Activity Database

Kosík, Adam; Feistauer, M.; Hadrava, Martin; Horáček, Jaromír

2015-01-01

Roč. 267, September (2015), s. 382-396 ISSN 0096-3003 R&D Projects: GA ČR(CZ) GAP101/11/0207 Institutional support: RVO:61388998 Keywords : discontinuous Galerkin method * nonlinear elasticity * compressible viscous flow * fluid–structure interaction Subject RIV: BI - Acoustics Impact factor: 1.345, year: 2015 http://www.sciencedirect.com/science/article/pii/S0096300315002453/pdfft?md5=02d46bc730e3a7fb8a5008aaab1da786&pid=1-s2.0-S0096300315002453-main.pdf

Vertebral Fractures After Discontinuation of Denosumab

DEFF Research Database (Denmark)

Cummings, Steven R; Ferrari, Serge; Eastell, Richard

2018-01-01

. We analyzed the risk of new or worsening vertebral fractures, especially multiple vertebral fractures, in participants who discontinued denosumab during the FREEDOM study or its Extension. Participants received ≥2 doses of denosumab or placebo Q6M, discontinued treatment, and stayed in the study ≥7...... months after the last dose. Of 1001 participants who discontinued denosumab during FREEDOM or Extension, the vertebral fracture rate increased from 1.2 per 100 participant-years during the on-treatment period to 7.1, similar to participants who received and then discontinued placebo (n = 470; 8.5 per 100....... Therefore, patients who discontinue denosumab should rapidly transition to an alternative antiresorptive treatment. Clinicaltrails.gov: NCT00089791 (FREEDOM) and NCT00523341 (Extension). © 2017 American Society for Bone and Mineral Research....

Dissolved organic carbon and major and trace elements in peat porewater of sporadic, discontinuous, and continuous permafrost zones of western Siberia

Science.gov (United States)

Raudina, Tatiana V.; Loiko, Sergey V.; Lim, Artyom G.; Krickov, Ivan V.; Shirokova, Liudmila S.; Istigechev, Georgy I.; Kuzmina, Daria M.; Kulizhsky, Sergey P.; Vorobyev, Sergey N.; Pokrovsky, Oleg S.

2017-07-01

Mobilization of dissolved organic carbon (DOC) and related trace elements (TEs) from the frozen peat to surface waters in the permafrost zone is expected to enhance under ongoing permafrost thaw and active layer thickness (ALT) deepening in high-latitude regions. The interstitial soil solutions are efficient tracers of ongoing bio-geochemical processes in the critical zone and can help to decipher the intensity of carbon and metals migration from the soil to the rivers and further to the ocean. To this end, we collected, across a 640 km latitudinal transect of the sporadic to continuous permafrost zone of western Siberia peatlands, soil porewaters from 30 cm depth using suction cups and we analyzed DOC, dissolved inorganic carbon (DIC), and 40 major elements and TEs in 0.45 µm filtered fraction of 80 soil porewaters. Despite an expected decrease in the intensity of DOC and TE mobilization from the soil and vegetation litter to the interstitial fluids with the increase in the permafrost coverage and a decrease in the annual temperature and ALT, the DOC and many major and trace elements did not exhibit any distinct decrease in concentration along the latitudinal transect from 62.2 to 67.4° N. The DOC demonstrated a maximum of concentration at 66° N, on the border of the discontinuous/continuous permafrost zone, whereas the DOC concentration in peat soil solutions from the continuous permafrost zone was equal to or higher than that in the sporadic/discontinuous permafrost zone. Moreover, a number of major (Ca, Mg) and trace (Al, Ti, Sr, Ga, rare earth elements (REEs), Zr, Hf, Th) elements exhibited an increasing, not decreasing, northward concentration trend. We hypothesize that the effects of temperature and thickness of the ALT are of secondary importance relative to the leaching capacity of peat, which is in turn controlled by the water saturation of the peat core. The water residence time in peat pores also plays a role in enriching the fluids in some elements

Dissolved organic carbon and major and trace elements in peat porewater of sporadic, discontinuous, and continuous permafrost zones of western Siberia

Directory of Open Access Journals (Sweden)

T. V. Raudina

2017-07-01

Full Text Available Mobilization of dissolved organic carbon (DOC and related trace elements (TEs from the frozen peat to surface waters in the permafrost zone is expected to enhance under ongoing permafrost thaw and active layer thickness (ALT deepening in high-latitude regions. The interstitial soil solutions are efficient tracers of ongoing bio-geochemical processes in the critical zone and can help to decipher the intensity of carbon and metals migration from the soil to the rivers and further to the ocean. To this end, we collected, across a 640 km latitudinal transect of the sporadic to continuous permafrost zone of western Siberia peatlands, soil porewaters from 30 cm depth using suction cups and we analyzed DOC, dissolved inorganic carbon (DIC, and 40 major elements and TEs in 0.45 µm filtered fraction of 80 soil porewaters. Despite an expected decrease in the intensity of DOC and TE mobilization from the soil and vegetation litter to the interstitial fluids with the increase in the permafrost coverage and a decrease in the annual temperature and ALT, the DOC and many major and trace elements did not exhibit any distinct decrease in concentration along the latitudinal transect from 62.2 to 67.4° N. The DOC demonstrated a maximum of concentration at 66° N, on the border of the discontinuous/continuous permafrost zone, whereas the DOC concentration in peat soil solutions from the continuous permafrost zone was equal to or higher than that in the sporadic/discontinuous permafrost zone. Moreover, a number of major (Ca, Mg and trace (Al, Ti, Sr, Ga, rare earth elements (REEs, Zr, Hf, Th elements exhibited an increasing, not decreasing, northward concentration trend. We hypothesize that the effects of temperature and thickness of the ALT are of secondary importance relative to the leaching capacity of peat, which is in turn controlled by the water saturation of the peat core. The water residence time in peat pores also plays a role in enriching the

Ultrasonic assessment of shrinkage type discontinuities

International Nuclear Information System (INIS)

Hubber, John

2010-01-01

This investigation into ultrasonic internal discontinuities is intended to demonstrate typical examples of internal 'shrinkage' type discontinuities and its connection with the casting suitability, integrity and reliability in service. This type of discontinuity can be misinterpreted by ultrasonic technicians and can lead to the rejection of castings unnecessarily, due to the mis-characterization of fine shrinkage - discrete porosity. The samples for this investigation were taken from thirty ton heavy section ductile iron mill flange castings, manufactured by Graham Campbell Ferrum International. The sampled area was of discontinuities that were recorded for sizing on an area due to loss of back wall echo, but had acceptable reflectivity. A comparative sample was taken adjacent to the area of discrete porosity. The discontinuities found by this investigation are of a 'spongy' type, gaseous in appearance and are surrounded by acoustically sound material. All discontinuities discussed in this paper are centrally located in the through thickness of the casting. The porous nature of this type of discontinuity consisting of approximately 80-90% metal has its own residual strength, as indicated by the proof stress results which reveal a residual strength of up to 50-60% of that of the unaffected area of the casting. The affected areas are elliptical in shape and vary in density and through thickness throughout.

A discontinuous Galerkin method for solving transient Maxwell equations with nonlinear material properties

KAUST Repository

Sirenko, Kostyantyn

2014-07-01

Discontinuous Galerkin time-domain method (DGTD) has been used extensively in computational electromagnetics for analyzing transient electromagnetic wave interactions on structures described with linear constitutive relations. DGTD expands unknown fields independently on disconnected mesh elements and uses numerical flux to realize information exchange between fields on different elements (J. S. Hesthaven and T. Warburton, Nodal Discontinuous Galerkin Method, 2008). The numerical flux of choice for \\'linear\\' Maxwell equations is the upwind flux, which mimics accurately the physical behavior of electromagnetic waves on discontinuous boundaries. It is obtained from the analytical solution of the Riemann problem defined on the boundary of two neighboring mesh elements.

A discontinuous Galerkin method for solving transient Maxwell equations with nonlinear material properties

KAUST Repository

Sirenko, Kostyantyn; Asirim, Ozum Emre; Bagci, Hakan

2014-01-01

Discontinuous Galerkin time-domain method (DGTD) has been used extensively in computational electromagnetics for analyzing transient electromagnetic wave interactions on structures described with linear constitutive relations. DGTD expands unknown fields independently on disconnected mesh elements and uses numerical flux to realize information exchange between fields on different elements (J. S. Hesthaven and T. Warburton, Nodal Discontinuous Galerkin Method, 2008). The numerical flux of choice for 'linear' Maxwell equations is the upwind flux, which mimics accurately the physical behavior of electromagnetic waves on discontinuous boundaries. It is obtained from the analytical solution of the Riemann problem defined on the boundary of two neighboring mesh elements.

Stabilities of MHD rotational discontinuities

International Nuclear Information System (INIS)

Wang, S.

1984-11-01

In this paper, the stabilities of MHD rotational discontinuities are analyzed. The results show that the rotational discontinuities in an incompressible magnetofluid are not always stable with respect to infinitesimal perturbation. The instability condition in a special case is obtained. (author)

Successful Discontinuation of Infliximab in a Refractory Case of Vasculo-Behçet Disease

Directory of Open Access Journals (Sweden)

Akihiro Nakamura

2016-01-01

Full Text Available Reports have shown that antitumor necrosis factor alpha (anti-TNF-α agents including infliximab (IFX can dramatically suppress the disease activity of refractory vasculo-Behçet disease (vasculo-BD. However, it is completely unknown whether we can discontinue anti-TNF-α agents under clinical remission. A 31-year-old patient with vasculo-BD was initially treated with a high dose of steroid and intravenous cyclophosphamide therapy. Six months later, however, the disease recurred. IFX was administered and immediately the disease activity was reduced. Fortunately, we could discontinue IFX after 18-month remission and no recurrence has been observed. Based on previous reports and our patient, all patients who could discontinue IFX sustained clinical remission for at least one year, continued taking immunosuppressive agents such as methotrexate and azathioprine, and had vascular involvements only in non-life-threatening major vessels such as leg or arm arteries/veins. This is a report suggesting the possibility of discontinuation of IFX in vasculo-BD.

Introduction to the special issue on discontinuity of fluvial systems

Science.gov (United States)

Burchsted, Denise; Daniels, Melinda; Wohl, Ellen E.

2014-01-01

Fluvial systems include natural and human-created barriers that modify local base level; as such, these discontinuities alter the longitudinal flux of water and sediment by storing, releasing, or changing the flow path of those materials. Even in the absence of distinct barriers, fluvial systems are typically discontinuous and patchy. The size of fluvial discontinuities ranges across scales from 100 m, such as riffles, to 104 m, such as lava dams or major landslides. The frequency of occurrence appears to be inversely related to size, with creation and failure of the small features, such as beaver dams, occurring on a time scale of 100 to 101 years and a frequency of occurrence at scales as low as 101 m. In contrast, larger scale discontinuities, such as lava dams, can last for time scales up to 105 years and have a frequency of occurrence of approximately 104 m. The heterogeneity generated by features is an essential part of river networks and should be considered as part of river management. Therefore, we suggest that "natural" dams are a useful analog for human dams when evaluating options for river restoration. This collection of papers on the studies of natural dams includes bedrock barriers, log jams and beaver dams. The collection also addresses the discontinuity generated by a floodplain — in the absence of an obvious barrier in the channel — and tools for evaluation of riverbed heterogeneity. It is completed with a study of impact of human dams on floodplain sedimentation. These papers will help geomorphologists and river managers understand the factors that control river heterogeneity across scales and around the world.

Discontinuity model for internal transport barrier formation in reversed magnetic shear plasmas

International Nuclear Information System (INIS)

Kishimoto, Y.; Dettrick, S.A.; Li, J.Q.; Shirai, S.; Kim, J.Y.; Horton, W.; Tajima, T.; LeBrun, M.J.

2000-01-01

It is becoming clear that tokamak anomalous transport is dominated by radially extended non-local modes which originate from strong toroidal coupling of rational surfaces in non-uniform plasmas. To aid in understanding the internal transport barrier (ITB) formed in reversed magnetic shear experiments, in addition to the well known shear flow effect, the article points out an important non-local effect and/or finite size effect which comes from the complex behaviour of the mode over a finite radial region around the minimum q (safety factor) surface. The non-local mode, which is characterized by its radial extent and the degree of tilting in the poloidal direction (Δr, θ 0 ), changes its structure depending on the sign of the magnetic shear, and as a result such modes are weakly excited across the q min surface. This leads to a discontinuity or gap which disconnects the phase relation in the global wave structure across the q min surface. Once such a discontinuity (or gap) is formed, transport suppression occurs and therefore a transport barrier can be expected near the q min surface. The existence of this discontinuity is confirmed through use of a toroidal particle simulation. It is also shown that whether such a discontinuity is efficiently established depends on the presence of the radial electric field and the related plasma shear flow. (author)

Management applications of discontinuity theory | Science ...

Science.gov (United States)

1.Human impacts on the environment are multifaceted and can occur across distinct spatiotemporal scales. Ecological responses to environmental change are therefore difficult to predict, and entail large degrees of uncertainty. Such uncertainty requires robust tools for management to sustain ecosystem goods and services and maintain resilient ecosystems. 2.We propose an approach based on discontinuity theory that accounts for patterns and processes at distinct spatial and temporal scales, an inherent property of ecological systems. Discontinuity theory has not been applied in natural resource management and could therefore improve ecosystem management because it explicitly accounts for ecological complexity. 3.Synthesis and applications. We highlight the application of discontinuity approaches for meeting management goals. Specifically, discontinuity approaches have significant potential to measure and thus understand the resilience of ecosystems, to objectively identify critical scales of space and time in ecological systems at which human impact might be most severe, to provide warning indicators of regime change, to help predict and understand biological invasions and extinctions and to focus monitoring efforts. Discontinuity theory can complement current approaches, providing a broader paradigm for ecological management and conservation This manuscript provides insight on using discontinuity approaches to aid in managing complex ecological systems. In part

NUMERICAL SIMULATION OF SHOCK WAVE REFRACTION ON INCLINED CONTACT DISCONTINUITY

Directory of Open Access Journals (Sweden)

P. V. Bulat

2016-05-01

Full Text Available We consider numerical simulation of shock wave refraction on plane contact discontinuity, separating two gases with different density. Discretization of Euler equations is based on finite volume method and WENO finite difference schemes, implemented on unstructured meshes. Integration over time is performed with the use of the third-order Runge–Kutta stepping procedure. The procedure of identification and classification of gas dynamic discontinuities based on conditions of dynamic consistency and image processing methods is applied to visualize and interpret the results of numerical calculations. The flow structure and its quantitative characteristics are defined. The results of numerical and experimental visualization (shadowgraphs, schlieren images, and interferograms are compared.

Identifying the factors underlying discontinuation of triptans.

Science.gov (United States)

Wells, Rebecca E; Markowitz, Shira Y; Baron, Eric P; Hentz, Joseph G; Kalidas, Kavita; Mathew, Paul G; Halker, Rashmi; Dodick, David W; Schwedt, Todd J

2014-02-01

To identify factors associated with triptan discontinuation among migraine patients. It is unclear why many migraine patients who are prescribed triptans discontinue this treatment. This study investigated correlates of triptan discontinuation with a focus on potentially modifiable factors to improve compliance. This multicenter cross-sectional survey (n = 276) was performed at US tertiary care headache clinics. Headache fellows who were members of the American Headache Society Headache Fellows Research Consortium recruited episodic and chronic migraine patients who were current triptan users (use within prior 3 months and for ≥1 year) or past triptan users (no use within 6 months; prior use within 2 years). Univariate analyses were first completed to compare current triptan users to past users for: migraine characteristics, other migraine treatments, triptan education, triptan efficacy, triptan side effects, type of prescribing provider, Migraine Disability Assessment (MIDAS) scores and Beck Depression Inventory (BDI) scores. Then, a multivariable logistic regression model was selected from all possible combinations of predictor variables to determine the factors that best correlated with triptan discontinuation. Compared with those still using triptans (n = 207), those who had discontinued use (n = 69) had higher rates of medication overuse (30 vs. 18%, P = .04) and were more likely to have ever used opioids for migraine treatment (57 vs. 38%, P = .006) as well as higher MIDAS (mean 63 vs. 37, P = .001) and BDI scores (mean 10.4 vs. 7.4, P = .009). Compared with discontinued users, current triptan users were more likely to have had their triptan prescribed by a specialist (neurologist, headache specialist, or pain specialist) (74 vs. 54%, P = .002) and were more likely to report headache resolution (53 vs. 14%, P  24 (2.6, [1.5, 4.6]), BDI >4 (2.5, [1.4, 4.5]), and a history of ever using opioids for migraine therapy (2.2, [1

27 CFR 478.127 - Discontinuance of business.

Science.gov (United States)

2010-04-01

... business was located: Provided, however, Where State law or local ordinance requires the delivery of... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Discontinuance of business... Records § 478.127 Discontinuance of business. Where a licensed business is discontinued and succeeded by a...

Oral contraceptive discontinuation and its aftermath in 19 developing countries.

Science.gov (United States)

Ali, Mohamed M; Cleland, John

2010-01-01

The purpose of the article was to document oral contraceptive (OC) discontinuation and switching in a large number of low- and middle-income countries, and to assess the effects of women's education and reason for use (spacing vs. limitation). An attempt was made to explain intercountry variations. Calendar data from 19 Demographic and Health Surveys conducted between 1999 and 2005 were used. Data were analyzed by single- and multiple-decrement life tables and by Cox proportional hazard model. The probability of stopping OC use within 12 months for reasons that implied dissatisfaction with the method ranged from 15% in Indonesia to over 40% in Bolivia and Peru with a median value of 28%. On average, 35% switched to a modern method within 3 months and 16% to a less effective 'traditional' method. Both education and reason for use were strongly related to the probability of switching to a modern method. Discontinuation was lower and switching higher in countries judged to have strong family planning programs. Both discontinuation of use and inadequate switching to alternative methods are major but neglected problems in the family planning services of many developing countries.

Multigrid technique and Optimized Schwarz method on block-structured grids with discontinuous interfaces

DEFF Research Database (Denmark)

Kolmogorov, Dmitry; Sørensen, Niels N.; Shen, Wen Zhong

2013-01-01

An Optimized Schwarz method using Robin boundary conditions for relaxation scheme is presented in the frame of Multigrid method on discontinuous grids. At each iteration the relaxation scheme is performed in two steps: one step with Dirichlet and another step with Robin boundary conditions at inn...

Testing discontinuities in nonparametric regression

KAUST Repository

Dai, Wenlin

2017-01-19

In nonparametric regression, it is often needed to detect whether there are jump discontinuities in the mean function. In this paper, we revisit the difference-based method in [13 H.-G. Müller and U. Stadtmüller, Discontinuous versus smooth regression, Ann. Stat. 27 (1999), pp. 299–337. doi: 10.1214/aos/1018031100

Testing discontinuities in nonparametric regression

KAUST Repository

Dai, Wenlin; Zhou, Yuejin; Tong, Tiejun

2017-01-01

In nonparametric regression, it is often needed to detect whether there are jump discontinuities in the mean function. In this paper, we revisit the difference-based method in [13 H.-G. Müller and U. Stadtmüller, Discontinuous versus smooth regression, Ann. Stat. 27 (1999), pp. 299–337. doi: 10.1214/aos/1018031100

Regge calculus from discontinuous metrics

International Nuclear Information System (INIS)

Khatsymovsky, V.M.

2003-01-01

Regge calculus is considered as a particular case of the more general system where the linklengths of any two neighbouring 4-tetrahedra do not necessarily coincide on their common face. This system is treated as that one described by metric discontinuous on the faces. In the superspace of all discontinuous metrics the Regge calculus metrics form some hypersurface defined by continuity conditions. Quantum theory of the discontinuous metric system is assumed to be fixed somehow in the form of quantum measure on (the space of functionals on) the superspace. The problem of reducing this measure to the Regge hypersurface is addressed. The quantum Regge calculus measure is defined from a discontinuous metric measure by inserting the δ-function-like phase factor. The requirement that continuity conditions be imposed in a 'face-independent' way fixes this factor uniquely. The term 'face-independent' means that this factor depends only on the (hyper)plane spanned by the face, not on it's form and size. This requirement seems to be natural from the viewpoint of existence of the well-defined continuum limit maximally free of lattice artefacts

NON-AXISYMMETRIC PERPENDICULAR DIFFUSION OF CHARGED PARTICLES AND THEIR TRANSPORT ACROSS TANGENTIAL MAGNETIC DISCONTINUITIES

Energy Technology Data Exchange (ETDEWEB)

Strauss, R. D.; Engelbrecht, N. E.; Dunzlaff, P. [Center for Space Research, North-West University, Potchefstroom, 2522 (South Africa); Roux, J. A. le [Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL 3585 (United States); Ruffolo, D., E-mail: dutoit.strauss@nwu.ac.za [Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 (Thailand)

2016-07-01

We investigate the transport of charged particles across magnetic discontinuities, focusing specifically on stream interfaces associated with co-rotating interaction regions in the solar wind. We argue that the magnetic field fluctuations perpendicular to the magnetic discontinuity, and usually also perpendicular to the mean magnetic field, are strongly damped in the vicinity of such a magnetic structure, leading to anisotropic perpendicular diffusion. Assuming that perpendicular diffusion arises from drifts in a turbulent magnetic field, we adopt a simplified approach to derive the relevant perpendicular diffusion coefficient. This approach, which we believe gives the correct principal dependences as expected from more elaborate calculations, allows us to investigate transport in different turbulent geometries, such as longitudinal compressional turbulence that may be present near the heliopause. Although highly dependent on the (possibly anisotropic) perpendicular length scales and turbulence levels, we generally find perpendicular diffusion to be strongly damped at magnetic discontinuities, which may in turn provide an explanation for the large particle gradients associated with these structures.

Green's function approach to neutron flux discontinuities

International Nuclear Information System (INIS)

Saad, E.A.; El-Wakil, S.A.

1980-01-01

The present work is devoted to the presentation of analytical method for the calculation of elastically and inelastically slowed down neutrons in an infinite non-absorbing medium. On the basis of the central limit theory (CLT) and the integral transform technique the slowing down equation including inelastic scattering, in terms of the Green function of elastic scattering, is solved. The Green function is decomposed according to the number of collisions. Placzec discontinuity associated with elastic scattering in addition to two discontinuities due to inelastic scattering are investigated. Numerical calculations for Fe 56 show that the elastic discontinuity produces about 41.8% change in the collision density whilst the ratio of the inelastic collision density discontinuity at qsub(o)sup(+) to the Placzec discontinuity at usub(o) + 1n 1/oc gives 55.7 percent change. (author)

Effects of discontinuities of the derivatives of the inflaton potential

Energy Technology Data Exchange (ETDEWEB)

Cadavid, Alexander Gallego [Instituto de Fisica, Universidad de Antioquia, A.A.1226, Medellin (Colombia); Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto (Japan); Romano, Antonio Enea, E-mail: aer@physics.uoc.gr [Instituto de Fisica, Universidad de Antioquia, A.A.1226, Medellin (Colombia); Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto (Japan); Department of Physics, University of Crete, 71003, Heraklion (Greece)

2015-12-12

We study the effects of a class of features of the inflaton potential, corresponding to discontinuities in its derivatives. We perform fully numerical calculations and derive analytical approximations for the curvature perturbations spectrum and the bispectrum which are in good agreement with the numerical results. The spectrum of primordial perturbations has oscillations around the scale k{sub 0} which leaves the horizon at the time τ{sub 0} when the feature occurs, with the amplitude and phase of the oscillations determined by the size and the order of the discontinuity. The large scale bispectrum in the squeezed and equilateral limits have a very similar form and are linearly suppressed. Both in the squeezed and the equilateral small scale limit the bispectrum has an oscillatory behavior whose phase depends on the parameters determining the discontinuity, and whose amplitude is inversely proportional to the scale. Given the generality of this class of features they could be used to model or classify phenomenologically different types of non-Gaussian features encountered in observational data such as the cosmic microwave background radiation or large scale structure.

Effects of discontinuities of the derivatives of the inflaton potential

Energy Technology Data Exchange (ETDEWEB)

Gallego Cadavid, Alexander [Universidad de Antioquia, Instituto de Fisica, Medellin (Colombia); Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Enea Romano, Antonio [Universidad de Antioquia, Instituto de Fisica, Medellin (Colombia); Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); University of Crete, Department of Physics, Heraklion (Greece)

2015-12-15

We study the effects of a class of features of the inflaton potential, corresponding to discontinuities in its derivatives. We perform fully numerical calculations and derive analytical approximations for the curvature perturbations spectrum and the bispectrum which are in good agreement with the numerical results. The spectrum of primordial perturbations has oscillations around the scale k{sub 0} which leaves the horizon at the time τ{sub 0} when the feature occurs, with the amplitude and phase of the oscillations determined by the size and the order of the discontinuity. The large scale bispectrum in the squeezed and equilateral limits have a very similar form and are linearly suppressed. Both in the squeezed and the equilateral small scale limit the bispectrum has an oscillatory behavior whose phase depends on the parameters determining the discontinuity, and whose amplitude is inversely proportional to the scale. Given the generality of this class of features they could be used to model or classify phenomenologically different types of non-Gaussian features encountered in observational data such as the cosmic microwave background radiation or large scale structure. (orig.)

Neural networks with discontinuous/impact activations

CERN Document Server

Akhmet, Marat

2014-01-01

This book presents as its main subject new models in mathematical neuroscience. A wide range of neural networks models with discontinuities are discussed, including impulsive differential equations, differential equations with piecewise constant arguments, and models of mixed type. These models involve discontinuities, which are natural because huge velocities and short distances are usually observed in devices modeling the networks. A discussion of the models, appropriate for the proposed applications, is also provided. This book also: Explores questions related to the biological underpinning for models of neural networks\\ Considers neural networks modeling using differential equations with impulsive and piecewise constant argument discontinuities Provides all necessary mathematical basics for application to the theory of neural networks Neural Networks with Discontinuous/Impact Activations is an ideal book for researchers and professionals in the field of engineering mathematics that have an interest in app...

Interferon alpha 2 maintenance therapy may enable high rates of treatment discontinuation in chronic myeloid leukemia.

Science.gov (United States)

Burchert, A; Saussele, S; Eigendorff, E; Müller, M C; Sohlbach, K; Inselmann, S; Schütz, C; Metzelder, S K; Ziermann, J; Kostrewa, P; Hoffmann, J; Hehlmann, R; Neubauer, A; Hochhaus, A

2015-06-01

A minority of chronic myeloid leukemia (CML) patients is capable of successfully discontinuing imatinib. Treatment modalities to increase this proportion are currently unknown. Here, we assessed the role of interferon alpha 2a (IFN) on therapy discontinuation in a previously reported cohort of 20 chronic phase CML patients who were treated upfront with IFN alpha plus imatinib followed by IFN monotherapy to maintain cytogenetic or molecular remission (MR) after imatinib discontinuation. After a median follow-up of 7.9 years (range, 5.2-12.2), relapse-free survival was 73% (8/11 patients) and 84% (5/6 patients) for patients who discontinued imatinib in major MR (MMR) and MR4/MR4.5, respectively. Ten patients discontinued IFN after a median of 4.5 years (range, 0.24-9.3). After a median of 2.8 years (range, 0.7-5.1), nine of them remain in ongoing treatment-free remission with MR5 (n=6) and MR4.5 (n=3). The four patients who still administer IFN are in stable MR5, MR4.5, MR4, and MMR, respectively. In conclusion, an IFN/imatinib induction treatment followed by a temporary IFN maintenance therapy may enable a high rate of treatment discontinuation in CML patients in at least MMR when stopping imatinib.

General practitioners' decisions about discontinuation of medication: an explorative study.

Science.gov (United States)

Nixon, Michael Simon; Vendelø, Morten Thanning

2016-06-20

Purpose - The purpose of this paper is to investigate how general practitioners' (GPs) decisions about discontinuation of medication are influenced by their institutional context. Design/methodology/approach - In total, 24 GPs were interviewed, three practices were observed and documents were collected. The Gioia methodology was used to analyse data, drawing on a theoretical framework that integrate the sensemaking perspective and institutional theory. Findings - Most GPs, who actively consider discontinuation, are reluctant to discontinue medication, because the safest course of action for GPs is to continue prescriptions, rather than discontinue them. The authors conclude that this is in part due to the ambiguity about the appropriateness of discontinuing medication, experienced by the GPs, and in part because the clinical guidelines do not encourage discontinuation of medication, as they offer GPs a weak frame for discontinuation. Three reasons for this are identified: the guidelines provide dominating triggers for prescribing, they provide weak priming for discontinuation as an option, and they underscore a cognitive constraint against discontinuation. Originality/value - The analysis offers new insights about decision making when discontinuing medication. It also offers one of the first examinations of how the institutional context embedding GPs influences their decisions about discontinuation. For policymakers interested in the discontinuation of medication, the findings suggest that de-stigmatising discontinuation on an institutional level may be beneficial, allowing GPs to better justify discontinuation in light of the ambiguity they experience.

Modular Adaptive System Based on a Multi-Stage Neural Structure for Recognition of 2D Objects of Discontinuous Production

Directory of Open Access Journals (Sweden)

I. Topalova

2005-03-01

Full Text Available This is a presentation of a new system for invariant recognition of 2D objects with overlapping classes, that can not be effectively recognized with the traditional methods. The translation, scale and partial rotation invariant contour object description is transformed in a DCT spectrum space. The obtained frequency spectrums are decomposed into frequency bands in order to feed different BPG neural nets (NNs. The NNs are structured in three stages - filtering and full rotation invariance; partial recognition; general classification. The designed multi-stage BPG Neural Structure shows very good accuracy and flexibility when tested with 2D objects used in the discontinuous production. The reached speed and the opportunuty for an easy restructuring and reprogramming of the system makes it suitable for application in different applied systems for real time work.

Modular Adaptive System Based on a Multi-Stage Neural Structure for Recognition of 2D Objects of Discontinuous Production

Directory of Open Access Journals (Sweden)

I. Topalova

2008-11-01

Full Text Available This is a presentation of a new system for invariant recognition of 2D objects with overlapping classes, that can not be effectively recognized with the traditional methods. The translation, scale and partial rotation invariant contour object description is transformed in a DCT spectrum space. The obtained frequency spectrums are decomposed into frequency bands in order to feed different BPG neural nets (NNs. The NNs are structured in three stages - filtering and full rotation invariance; partial recognition; general classification. The designed multi-stage BPG Neural Structure shows very good accuracy and flexibility when tested with 2D objects used in the discontinuous production. The reached speed and the opportunuty for an easy restructuring and reprogramming of the system makes it suitable for application in different applied systems for real time work.

Discontinuous Galerkin Method for Hyperbolic Conservation Laws

KAUST Repository

Mousikou, Ioanna

2016-11-11

Hyperbolic conservation laws form a special class of partial differential equations. They describe phenomena that involve conserved quantities and their solutions show discontinuities which reflect the formation of shock waves. We consider one-dimensional systems of hyperbolic conservation laws and produce approximations using finite difference, finite volume and finite element methods. Due to stability issues of classical finite element methods for hyperbolic conservation laws, we study the discontinuous Galerkin method, which was recently introduced. The method involves completely discontinuous basis functions across each element and it can be considered as a combination of finite volume and finite element methods. We illustrate the implementation of discontinuous Galerkin method using Legendre polynomials, in case of scalar equations and in case of quasi-linear systems, and we review important theoretical results about stability and convergence of the method. The applications of finite volume and discontinuous Galerkin methods to linear and non-linear scalar equations, as well as to the system of elastodynamics, are exhibited.

Discontinuous Galerkin Method for Hyperbolic Conservation Laws

KAUST Repository

Mousikou, Ioanna

2016-01-01

Hyperbolic conservation laws form a special class of partial differential equations. They describe phenomena that involve conserved quantities and their solutions show discontinuities which reflect the formation of shock waves. We consider one-dimensional systems of hyperbolic conservation laws and produce approximations using finite difference, finite volume and finite element methods. Due to stability issues of classical finite element methods for hyperbolic conservation laws, we study the discontinuous Galerkin method, which was recently introduced. The method involves completely discontinuous basis functions across each element and it can be considered as a combination of finite volume and finite element methods. We illustrate the implementation of discontinuous Galerkin method using Legendre polynomials, in case of scalar equations and in case of quasi-linear systems, and we review important theoretical results about stability and convergence of the method. The applications of finite volume and discontinuous Galerkin methods to linear and non-linear scalar equations, as well as to the system of elastodynamics, are exhibited.

Discontinuation Decision in Assisted Reproductive Techniques

Directory of Open Access Journals (Sweden)

Ashraf Moini

2009-01-01

Full Text Available Background: In vitro fertilization (IVF and intra cytoplasmic sperm injection (ICSI are recognizedas established and increasingly successful forms of treatment for infertility, yet significant numbersof couples discontinue treatment without achieving a live birth. This study aims to identify majorfactors that influence the decision to discontinue IVF/ICSI treatments.Materials and Methods: We studied the data of 338 couples who discontinued their infertilitytreatments after three cycles; based on medical records and phone contact. The main measure wasthe reason for stopping their treatments.Results: Economical problems were cited by 212 couples (62.7%, as their mean income wassignificantly less than other couples (p<0.0001. Lack of success was reported as a reason by229 (67.8%, from whom 165 (72% also had economical problems. Achieving independent-ART pregnancy was the reason for discontinuation in 20 (5.9% couples. Psychological stress,depression and anxiety were reported as other cessation factors by 169 (50%, 148 (43.8% and 182(53.8% couples, respectively.Conclusion: This survey suggests that the most common reasons for assisted reproductivetechnique (ART discontinuation after three cycles are: prior unsuccessful cycles, economicaland psychological problems. Therefore, the substantial proportion of couples could benefit frompsychological intervention, increasing awareness of ART outcomes and health funding to copemore adequately with failed treatments.

Seismic imaging of lithospheric discontinuities and continental evolution

Science.gov (United States)

Bostock, M. G.

1999-09-01

Discontinuities in physical properties within the continental lithosphere reflect a range of processes that have contributed to craton stabilization and evolution. A survey of recent seismological studies concerning lithospheric discontinuities is made in an attempt to document their essential characteristics. Results from long-period seismology are inconsistent with the presence of continuous, laterally invariant, isotropic boundaries within the upper mantle at the global scale. At regional scales, two well-defined interfaces termed H (˜60 km depth) and L (˜200 km depth) of continental affinity are identified, with the latter boundary generally exhibiting an anisotropic character. Long-range refraction profiles are frequently characterized by subcontinental mantle that exhibits a complex stratification within the top 200 km. The shallow layering of this package can behave as an imperfect waveguide giving rise to the so-called teleseismic Pn phase, while the L-discontinuity may define its lower base as the culmination of a low velocity zone. High-resolution, seismic reflection profiling provides sufficient detail in a number of cases to document the merging of mantle interfaces into lower continental crust below former collisional sutures and magmatic arcs, thus unambiguously identifying some lithospheric discontinuities with thrust faults and subducted oceanic lithosphere. Collectively, these and other seismic observations point to a continental lithosphere whose internal structure is dominated by a laterally variable, subhorizontal layering. This stratigraphy appears to be more pronounced at shallower lithospheric levels, includes dense, anisotropic layers of order 10 km in thickness, and exhibits horizontal correlation lengths comparable to the lateral dimensions of overlying crustal blocks. A model of craton evolution which relies on shallow subduction as a principal agent of craton stabilization is shown to be broadly compatible with these characteristics.

Safety of Temporary Discontinuation of Antihypertensive Medication in Patients With Difficult-to-Control Hypertension.

Science.gov (United States)

Beeftink, Martine M A; van der Sande, Nicolette G C; Bots, Michiel L; Doevendans, Pieter A; Blankestijn, Peter J; Visseren, Frank L J; Voskuil, Michiel; Spiering, Wilko

2017-05-01

Successful control of blood pressure relies on identification of secondary causes and contributing factors of hypertension. As antihypertensive medication can interfere with diagnostic investigations, temporary discontinuation of medication is advised. However, there are concerns about the safety of temporary discontinuation of antihypertensive medication in patients with difficult-to-control hypertension. We assessed the occurrence of adverse cardiovascular and cerebrovascular events potentially attributable to temporary discontinuation of antihypertensive medication between February 2010 and March 2016 (n=604) in our Analysis of Complicated Hypertension screening program. A reference group (n=604) was extracted from the SMART study (Second Manifestations of Arterial Disease) cohort (comprising a similar cohort at our hospital in whom medication was not stopped) and individually matched for blood pressure, age, sex, and history of cardiovascular disease. Discontinuation of medication was well tolerated; 62% reported no complaints, 24% had mild discomfort that could be left untreated, and 14% experienced complaints that required prescription of antihypertensive escape medication. Three major adverse events were observed in the Analysis of Complicated Hypertension group between discontinuation of medication and 30 days after restart of medication (event rate=31.2 events per 1000 patient-year). In the reference cohort, 5 cardiovascular events were observed during a similar follow-up period (event rate=51.2 events per 1000 patient-year). In conclusion, discontinuation of antihypertensive medication for the diagnostic evaluation of hypertension does not increase the acute risk of cardiovascular events when performed in a well-controlled setting in specialized hospitals with appropriate protocols for monitoring safety. © 2017 American Heart Association, Inc.

IUD discontinuation rates, switching behavior, and user satisfaction: findings from a retrospective analysis of a mobile outreach service program in Pakistan

Directory of Open Access Journals (Sweden)

Azmat SK

2013-01-01

Full Text Available Syed Khurram Azmat, Waqas Hameed, Ghulam Mustafa, Wajahat Hussain, Aftab Ahmed, Mohsina BilgramiMarie Stopes Society, Research and Metrics Department, Technical Services, Karachi, Sindh, PakistanBackground: In Pakistan, the uptake rate for the intrauterine device (IUD is very low at 2.5%. The most popular modern contraceptive methods in Pakistan are female sterilization and use of condoms. The Marie Stopes Society established its mobile outreach service delivery program with the aim of increasing use of modern quality contraceptive services, including the long-term reversible IUD, by women living in hard-to-reach areas. The present study attempts to assess IUD discontinuation rates and associated factors, including switching behavior and level of satisfaction with this type of service delivery.Methods: Using a cross-sectional approach, we contacted 681 women who had received an IUD from the Marie Stopes Society mobile outreach program during July and August 2009. Successful interviews were conducted with 639 of these women using a structured questionnaire. The data were analyzed with Stata 11.2 using simple descriptive Chi-square and Cox proportional techniques.Results: Analysis revealed that 19.4% (95% confidence interval 16.3–22.5 of the women discontinued use of their IUD at 10 months and, of these women, the majority (69.4% cited side effects as the main reason for discontinuation. Other factors, such as geographical catchment province, age of the woman, history of contraceptive use before IUD insertion, and side effects following insertion of the device, were found to be significantly associated with IUD. Amongst the women who had their IUD removed, 56.5% did not switch to any other contraceptive method, while 36.3% switched to either short-term or traditional methods, such as withdrawal, rhythm, and folk methods. Degree of satisfaction with the device was also significantly associated with discontinuation.Conclusion: Early

To Investigate the Flow Structure of Discontinuous Vegetation Patches of Two Vertically Different Layers in an Open Channel

Directory of Open Access Journals (Sweden)

Naveed Anjum

2018-01-01

Full Text Available In the present study, the flow structure of discontinuous double-layered vegetation patches was investigated using a 3D Reynolds stress turbulence model (RSM. The channel domain was built using GAMBIT (Geometry and Mesh Building Intelligent Toolkit. For the simulation and postprocessing, FLUENT (ANSYS was used to analyze the distribution of the mean velocity, Reynolds stresses, and other flow properties against two different flow conditions. The results captured by the turbulence model at specific locations and the cross section are presented in the form of various velocity profiles and contour plots. In the gap portion, the velocity was visibly lower than that in the vegetation areas, while the influence of patch distribution was not visible in the overlying flow layer. The velocity profiles at critical locations were categorized by numerous modulation points and velocity projections close to the bed, principally for positions straight after the vegetation structures. A distinction in the velocity at the topmost of the smaller vegetation structure was prominent. Reynolds stresses, turbulent kinetic energy, and turbulence intensity exhibited large fluctuations inside the vegetation regions and just behind the vegetation structures compared with in the gap regions.

Factors predicting successful discontinuation of continuous renal replacement therapy.

Science.gov (United States)

Katayama, S; Uchino, S; Uji, M; Ohnuma, T; Namba, Y; Kawarazaki, H; Toki, N; Takeda, K; Yasuda, H; Izawa, J; Tokuhira, N; Nagata, I

2016-07-01

This multicentre, retrospective observational study was conducted from January 2010 to December 2010 to determine the optimal time for discontinuing continuous renal replacement therapy (CRRT) by evaluating factors predictive of successful discontinuation in patients with acute kidney injury. Analysis was performed for patients after CRRT was discontinued because of renal function recovery. Patients were divided into two groups according to the success or failure of CRRT discontinuation. In multivariate logistic regression analysis, urine output at discontinuation, creatinine level and CRRT duration were found to be significant variables (area under the receiver operating characteristic curve for urine output, 0.814). In conclusion, we found that higher urine output, lower creatinine and shorter CRRT duration were significant factors to predict successful discontinuation of CRRT.

Trapped particles at a magnetic discontinuity

Science.gov (United States)

Stern, D. P.

1972-01-01

At a tangential discontinuity between two constant magnetic fields a layer of trapped particles can exist, this work examines the conditions under which the current carried by such particles tends to maintain the discontinuity. Three cases are examined. If the discontinuity separates aligned vacuum fields, the only requirement is that they be antiparallel. With arbitrary relative orientations, the field must have equal intensities on both sides. Finally, with a guiding center plasma on both sides, the condition reduces to a relation which is also derivable from hydromagnetic theory. Arguments are presented for the occurrence of such trapped modes in the magnetopause and for the non-existence of specular particle reflection.

Entropy stable high order discontinuous Galerkin methods for ideal compressible MHD on structured meshes

Science.gov (United States)

Liu, Yong; Shu, Chi-Wang; Zhang, Mengping

2018-02-01

We present a discontinuous Galerkin (DG) scheme with suitable quadrature rules [15] for ideal compressible magnetohydrodynamic (MHD) equations on structural meshes. The semi-discrete scheme is analyzed to be entropy stable by using the symmetrizable version of the equations as introduced by Godunov [32], the entropy stable DG framework with suitable quadrature rules [15], the entropy conservative flux in [14] inside each cell and the entropy dissipative approximate Godunov type numerical flux at cell interfaces to make the scheme entropy stable. The main difficulty in the generalization of the results in [15] is the appearance of the non-conservative "source terms" added in the modified MHD model introduced by Godunov [32], which do not exist in the general hyperbolic system studied in [15]. Special care must be taken to discretize these "source terms" adequately so that the resulting DG scheme satisfies entropy stability. Total variation diminishing / bounded (TVD/TVB) limiters and bound-preserving limiters are applied to control spurious oscillations. We demonstrate the accuracy and robustness of this new scheme on standard MHD examples.

Discontinuity effects in dynamically loaded tilting pad journal bearings

DEFF Research Database (Denmark)

Thomsen, Kim; Klit, Peder; Vølund, Anders

2011-01-01

This paper describes two discontinuity effects that can occur when modelling radial tilting pad bearings subjected to high dynamic loads. The first effect to be treated is a pressure build-up discontinuity effect. The second effect is a contact-related discontinuity that disappears when a contact...... force is included in the theoretical model. Methods for avoiding the pressure build-up discontinuity effect are proposed....

Discontinuous approximate molecular electronic wave-functions

International Nuclear Information System (INIS)

Stuebing, E.W.; Weare, J.H.; Parr, R.G.

1977-01-01

Following Kohn, Schlosser and Marcus and Weare and Parr an energy functional is defined for a molecular problem which is stationary in the neighborhood of the exact solution and permits the use of trial functions that are discontinuous. The functional differs from the functional of the standard Rayleigh--Ritz method in the replacement of the usual kinetic energy operators circumflex T(μ) with operators circumflex T'(μ) = circumflex T(μ) + circumflex I(μ) generates contributions from surfaces of nonsmooth behavior. If one uses the nabla PSI . nabla PSI way of writing the usual kinetic energy contributions, one must add surface integrals of the product of the average of nabla PSI and the change of PSI across surfaces of discontinuity. Various calculations are carried out for the hydrogen molecule-ion and the hydrogen molecule. It is shown that ab initio calculations on molecules can be carried out quite generally with a basis of atomic orbitals exactly obeying the zero-differential overlap (ZDO) condition, and a firm basis is thereby provided for theories of molecular electronic structure invoking the ZDO aoproximation. It is demonstrated that a valence bond theory employing orbitals exactly obeying ZDO can provide an adequate account of chemical bonding, and several suggestions are made regarding molecular orbital methods

Discontinuities during UV writing of waveguides

DEFF Research Database (Denmark)

Svalgaard, Mikael; Harpøth, Anders; Andersen, Marc

2005-01-01

UV writing of waveguides can be hampered by discontinuities where the index change process suddenly shuts down. We show that thermal effects may account for this behaviour.......UV writing of waveguides can be hampered by discontinuities where the index change process suddenly shuts down. We show that thermal effects may account for this behaviour....

Seismic detection method for small-scale discontinuities based on dictionary learning and sparse representation

Science.gov (United States)

Yu, Caixia; Zhao, Jingtao; Wang, Yanfei

2017-02-01

Studying small-scale geologic discontinuities, such as faults, cavities and fractures, plays a vital role in analyzing the inner conditions of reservoirs, as these geologic structures and elements can provide storage spaces and migration pathways for petroleum. However, these geologic discontinuities have weak energy and are easily contaminated with noises, and therefore effectively extracting them from seismic data becomes a challenging problem. In this paper, a method for detecting small-scale discontinuities using dictionary learning and sparse representation is proposed that can dig up high-resolution information by sparse coding. A K-SVD (K-means clustering via Singular Value Decomposition) sparse representation model that contains two stage of iteration procedure: sparse coding and dictionary updating, is suggested for mathematically expressing these seismic small-scale discontinuities. Generally, the orthogonal matching pursuit (OMP) algorithm is employed for sparse coding. However, the method can only update one dictionary atom at one time. In order to improve calculation efficiency, a regularized version of OMP algorithm is presented for simultaneously updating a number of atoms at one time. Two numerical experiments demonstrate the validity of the developed method for clarifying and enhancing small-scale discontinuities. The field example of carbonate reservoirs further demonstrates its effectiveness in revealing masked tiny faults and small-scale cavities.

Motion of Charged Particles near Magnetic Field Discontinuities

International Nuclear Information System (INIS)

Dodin, I.Y.; Fisch, N.J.

2000-01-01

The motion of charged particles in slowly changing magnetic fields exhibits adiabatic invariance even in the presence of abrupt magnetic discontinuities. Particles near discontinuities in magnetic fields, what we call ''boundary particles'', are constrained to remain near an arbitrarily fractured boundary even as the particle drifts along the discontinuity. A new adiabatic invariant applies to the motion of these particles

Multistability of neural networks with discontinuous non-monotonic piecewise linear activation functions and time-varying delays.

Science.gov (United States)

Nie, Xiaobing; Zheng, Wei Xing

2015-05-01

This paper is concerned with the problem of coexistence and dynamical behaviors of multiple equilibrium points for neural networks with discontinuous non-monotonic piecewise linear activation functions and time-varying delays. The fixed point theorem and other analytical tools are used to develop certain sufficient conditions that ensure that the n-dimensional discontinuous neural networks with time-varying delays can have at least 5(n) equilibrium points, 3(n) of which are locally stable and the others are unstable. The importance of the derived results is that it reveals that the discontinuous neural networks can have greater storage capacity than the continuous ones. Moreover, different from the existing results on multistability of neural networks with discontinuous activation functions, the 3(n) locally stable equilibrium points obtained in this paper are located in not only saturated regions, but also unsaturated regions, due to the non-monotonic structure of discontinuous activation functions. A numerical simulation study is conducted to illustrate and support the derived theoretical results. Copyright © 2015 Elsevier Ltd. All rights reserved.

Signal integrity analysis on discontinuous microstrip line

International Nuclear Information System (INIS)

Qiao, Qingyang; Dai, Yawen; Chen, Zipeng

2013-01-01

In high speed PCB design, microstirp lines were used to control the impedance, however, the discontinuous microstrip line can cause signal integrity problems. In this paper, we use the transmission line theory to study the characteristics of microstrip lines. Research results indicate that the discontinuity such as truncation, gap and size change result in the problems such as radiation, reflection, delay and ground bounce. We change the discontinuities to distributed parameter circuits, analysed the steady-state response and transient response and the phase delay. The transient response cause radiation and voltage jump.

Accountability Accentuates Interindividual-Intergroup Discontinuity by Enforcing Parochialism

OpenAIRE

Wildschut, T.; Van Horen, F.; Hart, C.

2015-01-01

Interindividual-intergroup discontinuity is the tendency for relations between groups to be more competitive than relations between individuals. We examined whether the discontinuity effect arises in part because group members experience normative pressure to favor the ingroup (parochialism). Building on the notion that accountability enhances normative pressure, we hypothesized that the discontinuity effect would be larger when accountability is present (compared to absent). A prisoner’s dil...

Discontinuities and the magnetospheric phenomena

International Nuclear Information System (INIS)

Rajaram, R.; Kalra, G.L.; Tandon, J.N.

1978-01-01

Wave coupling at contact discontinuities has an important bearing on the transmission of waves from the solar wind into the magnetosphere across the cusp region of the solar wind-magnetosphere boundary and on the propagation of geomagnetic pulsations in the polar exosphere. Keeping this in view, the problems of wave coupling across a contact discontinuity in a collisionless plasma, described by a set of double adiabatic fluid equations, is examined. The magnetic field is taken normal to the interface and it is shown that total reflection is not possible for any angle of incidence. The Alfven and the magneto-acoustic waves are not coupled. The transmission is most efficient for small density discontinuities. Inhibition of the transmission of the Alfven wave by the sharp density gradients above the F2-peak in the polar exosphere appears to account for the decrease in the pulsation amplitude, on the ground, as the poles are approached from the auroral zone. (author)

Strategies for discontinuation of proton pump inhibitors

DEFF Research Database (Denmark)

Haastrup, Peter; Paulsen, Maja S; Begtrup, Luise M

2014-01-01

PURPOSE: Proton pump inhibitors (PPIs) are considered to be overprescribed. Consensus on how to attempt discontinuation is, however, lacking. We therefore conducted a systematic review of clinical studies on discontinuation of PPIs. METHODS: Systematic review based on clinical studies investigating...

Red-Green-Blue Interferometer for the Metrology of Discontinuous Structures

Science.gov (United States)

Pförtner, Andreas; Schwider, Johannes

2003-02-01

Discontinuous surface profiles, e.g., diffractive optical elements (DOEs), are commonly measured by white-light interferometry. White-light interferometry needs significantly more memory capacity and computer time than does phase-shifting interferometry; there are approximately ten times more frames to be taken to gather the required information about the object under test. But usually the grooves of the DOEs are too deep for single-wavelength phase-shifting interferometry. Here we show how phase-shifting techniques can be applied to DOEs. For this purpose three interference patterns are recorded simultaneously by a three-chip color CCD camera at three wavelengths (Red-green-blue). It is possible to calculate separately the optical path difference at each pixel from the three phase patterns modulo 2 π. The algorithms used and experimental results are presented.

Discontinuity Detection in the Shield Metal Arc Welding Process.

Science.gov (United States)

Cocota, José Alberto Naves; Garcia, Gabriel Carvalho; da Costa, Adilson Rodrigues; de Lima, Milton Sérgio Fernandes; Rocha, Filipe Augusto Santos; Freitas, Gustavo Medeiros

2017-05-10

This work proposes a new methodology for the detection of discontinuities in the weld bead applied in Shielded Metal Arc Welding (SMAW) processes. The detection system is based on two sensors-a microphone and piezoelectric-that acquire acoustic emissions generated during the welding. The feature vectors extracted from the sensor dataset are used to construct classifier models. The approaches based on Artificial Neural Network (ANN) and Support Vector Machine (SVM) classifiers are able to identify with a high accuracy the three proposed weld bead classes: desirable weld bead, shrinkage cavity and burn through discontinuities. Experimental results illustrate the system's high accuracy, greater than 90% for each class. A novel Hierarchical Support Vector Machine (HSVM) structure is proposed to make feasible the use of this system in industrial environments. This approach presented 96.6% overall accuracy. Given the simplicity of the equipment involved, this system can be applied in the metal transformation industries.

Contact discontinuities in a cold collision-free two-beam plasma

International Nuclear Information System (INIS)

Kirkland, K.B.; Sonnerup, B.U.O.

1982-01-01

A contact discontinuity in a collision-free magnetized plasma is a thin layer, possessing a nontrivial magnetic structure, across which no net plasma flow takes place (#betta#/sub n/ = 0) even though the magnetic field has a nonvanishing component (B/sub n/not =0) normal to it. This paper examines the structure of such discontinuities in a simple plasma model consisting of two oppositely directed cold ion beams and a background of cold massless electrons such that exact charge neutrality is maintained so that the electric field Eequivalent0. The basic equations describing self-consistent equilibria are developed for the more general situation where a net flow across the layer takes place (#betta#/sub n/ = 0) and where the magnetic field has two nonzero tangential components B/sub y/ and B/sub z/ but where E remains zero. These equations are then specialized to the case eta/sub n/equivalent0, B/sub z/equivalent0, and four different classes of sheets are obtained, all having thickness of the order of the ion inertial length: (1) layers separating two identical plasma and magnetic field regions. (2) an infinite array of parallel layers producing an undulated magnetic field, (3) layers containing trapped ions in closed orbits which separate two vacuum regions with uniform identical magnetic fields, and (4) layers which reflect a single plasma beam, leaving a vacuum with a revesed and compressed tangential field on the other side. Solutions for which #betta#/sub n/ = 0 but B/sub z/not =0 may also exist but have not been analyzed; rotational discontinuities are shown not to be possible in this model

Socio-Economic Differentials in Contraceptive Discontinuation in India

Directory of Open Access Journals (Sweden)

Kiran Agrahari

2016-05-01

Full Text Available Fertility divergence amid declining in use of modern contraception in many states of India needs urgent research and programmatic attention. Although utilization of antenatal, natal, and post-natal care has shown spectacular increase in post National Rural Health Mission (NRHM period, the contraceptive use had shown a declining trend. Using the calendar data from the National Family Health Survey–3, this article examines the reasons of contraceptive discontinuation among spacing method users by socio-economic groups in India. Bivariate and multivariate analyses and life table discontinuation rates are used in the analyses. Results suggest that about half of the pill users, two fifths of the condom users, one third of traditional method users, and one fifth of IUD users discontinue a method in first 12 months of use. However, the discontinuation of all three modern spacing methods declines in subsequent period (within 12-36 months. The probability of method failure was highest among traditional method users and higher among poor and less educated that may lead to unwanted/mistimed birth. Although discontinuation of condom declines with economic status, it does not show any large variation for pill users. The contraceptive discontinuation was significantly associated with duration of use, age, parity, contraceptive method, religion, and contraceptive intention. Based on these findings, it is suggested that follow-up services to modern spacing method users, increasing counseling for spacing method users, motivating the traditional method user to use modern spacing method, and improving the overall quality of family planning services can reduce the discontinuation of spacing method.

High Resolution Seismic Images of Transition Zone Discontinuities beneath the Hawaii-Emperor Seamount Chain

Science.gov (United States)

Cao, Q.; Wang, P.; van der Hilst, R. D.; Shim, S.

2009-12-01

Taking advantage of the abundance of natural sources (earthquakes) in western Pacific subduction zones and the many seismograph stations in the Americas, we use inverse scattering - a generalized Radon transform - of SS precursors to image the transition zone discontinuities underneath Hawaii and the Hawaii-Emperor seamount chain. The GRT makes use of scattering theory and extracts structural information from broad band data windows that include precursors to SS (which are the specular reflections at the discontinuities that form the main arrivals) as well as non-specular scattered energy (which is often discarded as noise). More than 150,000 seismograms (from the IRIS Data Management Center) are used to form a 3-D image of the transition zone discontinuities beneath the central Pacific. In addition to clear signals near 410, 520, and 660 km depth, the data also reveal scatter interfaces near 370 km dept and between 800-1000 km depth, which may be regional, laterally intermittent scatter horizons. Our images reveal a conspicuous uplift of the 660 discontinuity in a region of 800km in diameter to the west of the active volcanoes of Hawaii. No correspondent localized depression of the 410 discontinuity is found. Instead, we find a smaller scale anomaly suggesting that the 410 discontinuity is locally elevated in the same region. This may indicate the presence of melt or minor chemical constitutes. The lack of correlation between and differences in lateral length scale of the topographies of the 410 and 660 km discontinuities are also consistent with a deep-mantle plume impinging on the transition zone, creating a pond of hot material underneath 660 discontinuity, and with secondary plumes connecting to the present-day hotspot at Earth’s surface. Our observations suggest that more complicated plume morphology and plume dynamics within the Earth's mantle should be taken into account to describe the plumes and, in particular, mass transport across the transition zone

Detection and Correction of Step Discontinuities in Kepler Flux Time Series

Science.gov (United States)

Kolodziejczak, J. J.; Morris, R. L.

2011-01-01

PDC 8.0 includes an implementation of a new algorithm to detect and correct step discontinuities appearing in roughly one of every 20 stellar light curves during a given quarter. The majority of such discontinuities are believed to result from high-energy particles (either cosmic or solar in origin) striking the photometer and causing permanent local changes (typically -0.5%) in quantum efficiency, though a partial exponential recovery is often observed [1]. Since these features, dubbed sudden pixel sensitivity dropouts (SPSDs), are uncorrelated across targets they cannot be properly accounted for by the current detrending algorithm. PDC detrending is based on the assumption that features in flux time series are due either to intrinsic stellar phenomena or to systematic errors and that systematics will exhibit measurable correlations across targets. SPSD events violate these assumptions and their successful removal not only rectifies the flux values of affected targets, but demonstrably improves the overall performance of PDC detrending [1].

Continuous and discontinuous transitions to synchronization.

Science.gov (United States)

Wang, Chaoqing; Garnier, Nicolas B

2016-11-01

We describe how the transition to synchronization in a system of globally coupled Stuart-Landau oscillators changes from continuous to discontinuous when the nature of the coupling is moved from diffusive to reactive. We explain this drastic qualitative change as resulting from the co-existence of a particular synchronized macrostate together with the trivial incoherent macrostate, in a range of parameter values for which the latter is linearly stable. In contrast to the paradigmatic Kuramoto model, this particular state observed at the synchronization transition contains a finite, non-vanishing number of synchronized oscillators, which results in a discontinuous transition. We consider successively two situations where either a fully synchronized state or a partially synchronized state exists at the transition. Thermodynamic limit and finite size effects are briefly discussed, as well as connections with recently observed discontinuous transitions.

Continuous and Discontinuous Modelling of Fracture in Concrete Using FEM

CERN Document Server

Tejchman, Jacek

2013-01-01

The book analyzes a quasi-static fracture process in concrete and reinforced concrete by means of constitutive models formulated within continuum mechanics. A continuous and discontinuous modelling approach was used. Using a continuous approach, numerical analyses were performed using a finite element method and three different enhanced continuum models: isotropic elasto-plastic, isotropic damage and anisotropic smeared crack one. The models were equipped with a characteristic length of micro-structure by means of a non-local and a second-gradient theory. So they could properly describe the formation of localized zones with a certain thickness and spacing and a related deterministic size effect. Using a discontinuous FE approach, numerical results of cracks using a cohesive crack model and XFEM were presented which were also properly regularized. Finite element analyses were performed with concrete elements under monotonic uniaxial compression, uniaxial tension, bending and shear-extension. Concrete beams un...

[Discontinuation of depression treatment from the perspective of suicide prevention].

Science.gov (United States)

Cho, Yoshinori

2012-01-01

It is assumed that discontinuation of treatment for depression may increase the risk of suicide. A population-based register study in Denmark did not find a lower risk among people over age 50 who followed treatment in comparison with those who discontinued treatment with antidepressants at an early stage. This result, however, does not allow us to think superficially that early discontinuation of treatment does not increase the risk of suicide. It is because the study has limitations without information of such as psychiatric diagnoses, severity of the depressed state, and reasons of discontinuation. It is safe for clinicians to aim at preventing discontinuation of treatment. Particularly, in Japan and South Korea where there is a sociocultural climate of tolerability for suicide, suicide can occur in milder depressed state and discontinuation of treatment should be taken more seriously than in Western countries.

Risk of discontinuation of Advanced Therapy Medicinal Products clinical trials.

Science.gov (United States)

Hanna, Eve; Rémuzat, Cecile; Auquier, Pascal; Toumi, Mondher

2016-01-01

Advanced therapy medicinal products (ATMPs) constitute a class of innovative products that encompasses gene therapy, somatic cell therapy, and tissue-engineered products (TEP). There is an increased investment of commercial and non-commercial sponsors in this field and a growing number of ATMPs randomized clinical trials (RCT) and patients enrolled in such trials. RCT generate data to prove the efficacy of a new therapy, but the discontinuation of RCTs wastes scarce resources. Our objective is to identify the number and characteristics of discontinued ATMPs trials in order to evaluate the rate of discontinuation. We searched for ATMPs trials conducted between 1999 to June 2015 using three databases, which are Clinicaltrials.gov, the International Clinical Trials Registry Platform (ICTRP), and the EU Drug Regulating Authorities Clinical Trials (EudraCT). We selected the ATMPs trials after elimination of the duplicates. We identified the disease areas and the sponsors as commercial or non-commercial organizations. We classified ATMPs by type and trial status, that is, ongoing, completed, terminated, discontinued, and prematurely ended. Then, we calculated the rate of discontinuation. Between 1999 and June 2015, 143 withdrawn, terminated, or prematurely ended ATMPs clinical trials were identified. Between 1999 and June 2013, 474 ongoing and completed clinical trials were identified. Therefore, the rate of discontinuation of ATMPs trials is 23.18%, similar to that for non-ATMPs drugs in development. The probability of discontinuation is, respectively, 27.35, 16.28, and 16.34% for cell therapies, gene therapies, and TEP. The highest discontinuation rate is for oncology (43%), followed by cardiology (19.2%). It is almost the same for commercial and non-commercial sponsors; therefore, the discontinuation reason may not be financially driven. No failure risk rate per development phase is available for ATMPs. The discontinuation rate may prove helpful when assessing the

41 CFR 109-39.105 - Discontinuance or curtailment of service.

Science.gov (United States)

2010-07-01

... AVIATION, TRANSPORTATION, AND MOTOR VEHICLES 39-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.1-Establishment, Modification, and Discontinuance of Interagency Fleet Management Systems § 109-39.105 Discontinuance or... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Discontinuance or...

What happens when people discontinue taking medications? Lessons from COMBINE.

Science.gov (United States)

Stout, Robert L; Braciszewski, Jordan M; Subbaraman, Meenakshi Sabina; Kranzler, Henry R; O'Malley, Stephanie S; Falk, Daniel

2014-12-01

We use intensive longitudinal data methods to illuminate processes affecting patients' drinking in relation to the discontinuation of medications within an alcohol treatment study. Although previous work has focused on broad measures of medication adherence, we focus on dynamic changes in drinking both before and after patients discontinue. We conducted secondary data analyses using the COMBINE (Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence) study, focused on participants who discontinued medications prior to the planned end of treatment. Using an interrupted time-series analysis, we analysed drinking in the weeks before and after discontinuation and also studied outcomes at the end of the COMBINE follow-up. Unites States of America. We describe the subsample of COMBINE participants who discontinued medications (n = 450), and compare them with those who were medication-adherent (n = 559) and with those who discontinued but had substantial missing data (n = 217). The primary outcomes were percentage of days abstinent (PDA) and percentage of heavy drinking days (PHDD). Medication adherence data were used to approximate the date of discontinuation. For many patients, an increase in drinking began weeks before discontinuation (PDA: F(1,4803) = 19.07, P < 0.001; PHDD: F(1,4804) = 8.58, P = 0.003) then escalated at discontinuation (PDA: F(1,446) = 5.05, P = 0.025; PHDD: F(1,446) = 4.52, P = 0.034). Among other effects, the amount of change was moderated by the reason for discontinuation (e.g. adverse event; PDA: F(2,4803) = 3.85, P = 0.021; PHDD: F(2,4804) = 5.36, P = 0.005) and also whether it occurred in the first or second half of treatment (PDA: F(1,4803) = 5.23, P = 0.022; PHDD: F(1,4804) = 8.79, P = 0.003). A patient's decision to stop taking medications during alcohol treatment appears to take place during a weeks-long process of disengagement from treatment. Patients who discontinue medications early in treatment or without

Area Regge calculus and discontinuous metrics

International Nuclear Information System (INIS)

Wainwright, Chris; Williams, Ruth M

2004-01-01

Taking the triangle areas as independent variables in the theory of Regge calculus can lead to ambiguities in the edge lengths, which can be interpreted as discontinuities in the metric. We construct solutions to area Regge calculus using a triangulated lattice and find that on a spacelike or timelike hypersurface no such discontinuity can arise. On a null hypersurface however, we can have such a situation and the resulting metric can be interpreted as a so-called refractive wave

Physics-based process model approach for detecting discontinuity during friction stir welding

Energy Technology Data Exchange (ETDEWEB)

Shrivastava, Amber; Pfefferkorn, Frank E.; Duffie, Neil A.; Ferrier, Nicola J.; Smith, Christopher B.; Malukhin, Kostya; Zinn, Michael

2015-02-12

The goal of this work is to develop a method for detecting the creation of discontinuities during friction stir welding. This in situ weld monitoring method could significantly reduce the need for post-process inspection. A process force model and a discontinuity force model were created based on the state-of-the-art understanding of flow around an friction stir welding (FSW) tool. These models are used to predict the FSW forces and size of discontinuities formed in the weld. Friction stir welds with discontinuities and welds without discontinuities were created, and the differences in force dynamics were observed. In this paper, discontinuities were generated by reducing the tool rotation frequency and increasing the tool traverse speed in order to create "cold" welds. Experimental force data for welds with discontinuities and welds without discontinuities compared favorably with the predicted forces. The model currently overpredicts the discontinuity size.

Accountability Accentuates Interindividual-Intergroup Discontinuity by Enforcing Parochialism

NARCIS (Netherlands)

Wildschut, T.; Van Horen, F.; Hart, C.

2015-01-01

Interindividual-intergroup discontinuity is the tendency for relations between groups to be more competitive than relations between individuals. We examined whether the discontinuity effect arises in part because group members experience normative pressure to favor the ingroup (parochialism).

Accountability Accentuates Interindividual-Intergroup Discontinuity by Enforcing Parochialism.

Science.gov (United States)

Wildschut, Tim; van Horen, Femke; Hart, Claire

2015-01-01

Interindividual-intergroup discontinuity is the tendency for relations between groups to be more competitive than relations between individuals. We examined whether the discontinuity effect arises in part because group members experience normative pressure to favor the ingroup (parochialism). Building on the notion that accountability enhances normative pressure, we hypothesized that the discontinuity effect would be larger when accountability is present (compared to absent). A prisoner's dilemma game experiment supported this prediction. Specifically, intergroup (compared to interindividual) interaction activated an injunctive ingroup-favoring norm, and accountability enhanced the influence of this norm on competitive behavior.

A Simple Stochastic Differential Equation with Discontinuous Drift

DEFF Research Database (Denmark)

Simonsen, Maria; Leth, John-Josef; Schiøler, Henrik

2013-01-01

In this paper we study solutions to stochastic differential equations (SDEs) with discontinuous drift. We apply two approaches: The Euler-Maruyama method and the Fokker-Planck equation and show that a candidate density function based on the Euler-Maruyama method approximates a candidate density...... function based on the stationary Fokker-Planck equation. Furthermore, we introduce a smooth function which approximates the discontinuous drift and apply the Euler-Maruyama method and the Fokker-Planck equation with this input. The point of departure for this work is a particular SDE with discontinuous...

Regulation causes nitrogen cycling discontinuities in Mediterranean rivers.

Science.gov (United States)

von Schiller, Daniel; Aristi, Ibon; Ponsatí, Lídia; Arroita, Maite; Acuña, Vicenç; Elosegi, Arturo; Sabater, Sergi

2016-01-01

River regulation has fundamentally altered large sections of the world's river networks. The effects of dams on the structural properties of downstream reaches are well documented, but less is known about their effect on river ecosystem processes. We investigated the effect of dams on river nutrient cycling by comparing net uptake of total dissolved nitrogen (TDN), phosphorus (TDP) and organic carbon (DOC) in river reaches located upstream and downstream from three reservoir systems in the Ebro River basin (NE Iberian Peninsula). Increased hydromorphological stability, organic matter standing stocks and ecosystem metabolism below dams enhanced the whole-reach net uptake of TDN, but not that of TDP or DOC. Upstream from dams, river reaches tended to be at biogeochemical equilibrium (uptake≈release) for all nutrients, whereas river reaches below dams acted as net sinks of TDN. Overall, our results suggest that flow regulation by dams may cause relevant N cycling discontinuities in rivers. Higher net N uptake capacity below dams could lead to reduced N export to downstream ecosystems. Incorporating these discontinuities could significantly improve predictive models of N cycling and transport in complex river networks. Copyright © 2015. Published by Elsevier B.V.

Hippocampal agenesis in an individual who engaged in violent criminal behaviors after discontinuing carbamazepine and paroxetine treatment.

Science.gov (United States)

Hanada, Hiroaki; Akiyoshi, Jotaro; Kanehisa, Masayuki; Ishitobi, Yoshinobu; Tsuru, Jusen; Tanaka, Yoshihiro; Shimomura, Tsuyoshi; Kawano, Yoshihisa

2013-01-01

Antidepressant discontinuation syndrome (ADS) occurs after abrupt discontinuation of an antidepressant medication. A 23-year-old man with right hippocampal agenesis demonstrated sexual crime (hypersexuality) since the age of eight and had been successfully treated with carbamazepine since the age of 13. He had required increased doses of paroxetine and carbamazepine owing to the development of an unstable affect after quitting his job. He abruptly stopped taking his medication for 3 days and his criminal behaviors re-emerged. We examined changes in brain structure and activity before and after medication cessation, using MRI and functional MRI (fMRI). The image of a girl in a swimsuit increased activity in the thalamus only after medication discontinuation. The alteration in thalamic activity might induce hypersexuality. We conclude that a primary hypersexuality had been suppressed with carbamazepine and paroxetine treatment, and the discontinuation of the medication caused the hypersexuality. © 2012 American Academy of Forensic Sciences.

Automated extraction and analysis of rock discontinuity characteristics from 3D point clouds

Science.gov (United States)

Bianchetti, Matteo; Villa, Alberto; Agliardi, Federico; Crosta, Giovanni B.

2016-04-01

A reliable characterization of fractured rock masses requires an exhaustive geometrical description of discontinuities, including orientation, spacing, and size. These are required to describe discontinuum rock mass structure, perform Discrete Fracture Network and DEM modelling, or provide input for rock mass classification or equivalent continuum estimate of rock mass properties. Although several advanced methodologies have been developed in the last decades, a complete characterization of discontinuity geometry in practice is still challenging, due to scale-dependent variability of fracture patterns and difficult accessibility to large outcrops. Recent advances in remote survey techniques, such as terrestrial laser scanning and digital photogrammetry, allow a fast and accurate acquisition of dense 3D point clouds, which promoted the development of several semi-automatic approaches to extract discontinuity features. Nevertheless, these often need user supervision on algorithm parameters which can be difficult to assess. To overcome this problem, we developed an original Matlab tool, allowing fast, fully automatic extraction and analysis of discontinuity features with no requirements on point cloud accuracy, density and homogeneity. The tool consists of a set of algorithms which: (i) process raw 3D point clouds, (ii) automatically characterize discontinuity sets, (iii) identify individual discontinuity surfaces, and (iv) analyse their spacing and persistence. The tool operates in either a supervised or unsupervised mode, starting from an automatic preliminary exploration data analysis. The identification and geometrical characterization of discontinuity features is divided in steps. First, coplanar surfaces are identified in the whole point cloud using K-Nearest Neighbor and Principal Component Analysis algorithms optimized on point cloud accuracy and specified typical facet size. Then, discontinuity set orientation is calculated using Kernel Density Estimation and

State and data techniques for control of discontinuous systems

International Nuclear Information System (INIS)

Kisner, R.A.

1986-01-01

This paper describes a technique for structured analysis and design of automated control systems. The technique integrates control of continuous and discontinuous nuclear power plant subsystems and components. A hierarchical control system with distributed intelligence follows from applying the technique. Further, it can be applied to all phases of control system design. For simplicity, the example used in the paper is limited to phase 1 design (basic automatic control action), in which no maintenance, testing, or contingency capability is attempted. 11 figs

Low-index discontinuity terahertz waveguides

Science.gov (United States)

Nagel, Michael; Marchewka, Astrid; Kurz, Heinrich

2006-10-01

A new type of dielectric THz waveguide based on recent approaches in the field of integrated optics is presented with theoretical and experimental results. Although the guiding mechanism of the low-index discontinuity (LID) THz waveguide is total internal reflection, the THz wave is predominantly confined in the virtually lossless low-index air gap within a high-index dielectric waveguide due to the continuity of electric flux density at the dielectric interface. Attenuation, dispersion and single-mode confinement properties of two LID structures are discussed and compared with other THz waveguide solutions. The new approach provides an outstanding combination of high mode confinement and low transmission losses currently not realizable with any other metal-based or photonic crystal approach. These exceptional properties might enable the breakthrough of novel integrated THz systems or endoscopy applications with sub-wavelength resolution.

Uncertainty Quantification given Discontinuous Climate Model Response and a Limited Number of Model Runs

Science.gov (United States)

Sargsyan, K.; Safta, C.; Debusschere, B.; Najm, H.

2010-12-01

discontinuous model data with adjustable sharpness and structure. This work was supported by the Sandia National Laboratories Seniors’ Council LDRD (Laboratory Directed Research and Development) program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Accountability Accentuates Interindividual—Intergroup Discontinuity by Enforcing Parochialism

Directory of Open Access Journals (Sweden)

Tim eWildschut

2015-11-01

Full Text Available Interindividual-intergroup discontinuity is the tendency for relations between groups to be more competitive than relations between individuals. We examined whether the discontinuity effect arises in part because group members experience normative pressure to favor the ingroup (parochialism. Building on the notion that accountability enhances normative pressure, we hypothesized that the discontinuity effect would be larger when accountability is present (compared to absent. A prisoner’s dilemma game experiment supported this prediction. Specifically, intergroup (compared to interindividual interaction activated an injunctive ingroup-favoring norm, and accountability enhanced the influence of this norm on competitive behavior.

Adaptive Finite Element Methods for Elliptic Problems with Discontinuous Coefficients

KAUST Repository

Bonito, Andrea; DeVore, Ronald A.; Nochetto, Ricardo H.

2013-01-01

Elliptic PDEs with discontinuous diffusion coefficients occur in application domains such as diffusions through porous media, electromagnetic field propagation on heterogeneous media, and diffusion processes on rough surfaces. The standard approach to numerically treating such problems using finite element methods is to assume that the discontinuities lie on the boundaries of the cells in the initial triangulation. However, this does not match applications where discontinuities occur on curves, surfaces, or manifolds, and could even be unknown beforehand. One of the obstacles to treating such discontinuity problems is that the usual perturbation theory for elliptic PDEs assumes bounds for the distortion of the coefficients in the L∞ norm and this in turn requires that the discontinuities are matched exactly when the coefficients are approximated. We present a new approach based on distortion of the coefficients in an Lq norm with q < ∞ which therefore does not require the exact matching of the discontinuities. We then use this new distortion theory to formulate new adaptive finite element methods (AFEMs) for such discontinuity problems. We show that such AFEMs are optimal in the sense of distortion versus number of computations, and report insightful numerical results supporting our analysis. © 2013 Societ y for Industrial and Applied Mathematics.

Self-Referential Processing, Rumination, and Cortical Midline Structures in Major Depression

Science.gov (United States)

Nejad, Ayna Baladi; Fossati, Philippe; Lemogne, Cédric

2013-01-01

Major depression is associated with a bias toward negative emotional processing and increased self-focus, i.e., the process by which one engages in self-referential processing. The increased self-focus in depression is suggested to be of a persistent, repetitive and self-critical nature, and is conceptualized as ruminative brooding. The role of the medial prefrontal cortex in self-referential processing has been previously emphasized in acute major depression. There is increasing evidence that self-referential processing as well as the cortical midline structures play a major role in the development, course, and treatment response of major depressive disorder. However, the links between self-referential processing, rumination, and the cortical midline structures in depression are still poorly understood. Here, we reviewed brain imaging studies in depressed patients and healthy subjects that have examined these links. Self-referential processing in major depression seems associated with abnormally increased activity of the anterior cortical midline structures. Abnormal interactions between the lateralized task-positive network, and the midline cortical structures of the default mode network, as well as the emotional response network, may underlie the pervasiveness of ruminative brooding. Furthermore, targeting this maladaptive form of rumination and its underlying neural correlates may be key for effective treatment. PMID:24124416

Self-referential processing, rumination, and cortical midline structures in major depression

Directory of Open Access Journals (Sweden)

Ayna Baladi Nejad

2013-10-01

Full Text Available Major depression is associated with a bias towards negative emotional processing and increased self-focus, i.e. the process by which one engages in self-referential processing. The increased self-focus in depression is suggested to be of a persistent, repetitive and self-critical nature and is conceptualised as ruminative brooding. The role of the medial prefrontal cortex in self-referential processing has been previously emphasised in acute major depression. There is increasing evidence that self-referential processing as well as the cortical midline structures play a major role in the development, course and treatment response of major depressive disorder. However, the links between self-referential processing, rumination, and the cortical midline structures in depression are still poorly understood. Here, we reviewed brain imaging studies in depressed patients and healthy subjects that have examined these links. The literature suggests that self-referential processing in major depression is associated with increased activity of the anterior cortical midline structures. Abnormal interactions between the lateralised task-positive network, and the midline cortical structures of the default mode network, as well as the emotional response network, may underlie the pervasiveness of ruminative brooding. Furthermore, targeting this maladaptive form of rumination and its underlying neural correlates may be key for effective treatment.

39 CFR 241.3 - Discontinuance of post offices.

Science.gov (United States)

2010-07-01

... CLASSIFICATION, AND DISCONTINUANCE § 241.3 Discontinuance of post offices. (a) Introduction—(1) Coverage. This... justify in sufficient detail to Postal Service management and affected customers the proposed service... inspection during normal business hours at each post office where the Final Determination is posted for 30...

Discontinuation of nicotine replacement therapy among smoking-cessation attempters.

Science.gov (United States)

Burns, Emily K; Levinson, Arnold H

2008-03-01

Nicotine replacement therapy (NRT) doubles successful quitting, but more than half of NRT users do not comply with optimal treatment regimens. From the 2005 Colorado state tobacco survey, quit attempters who utilized NRT (N=366) were analyzed in spring 2007. Descriptive and regression analyses were used to examine reasons for discontinuing NRT, length of time on NRT, and quit intentions. The reasons for discontinuing NRT were resuming smoking (34%), side effects (17%), NRT not helping with quitting (14%), quitting smoking (10%), and cost (5%). Poverty, age, and non-Latino minority status were associated with reasons for discontinuation other than quitting smoking. Having side effects was associated with a short duration of NRT use and 95% lower odds of intending to quit in the next month. In the first population-level study examining reasons for discontinuing NRT, general-population smokers who initiate NRT use when attempting to quit are highly likely to discontinue NRT prematurely. Age and culturally-appropriate medication management interventions may increase NRT compliance and improve cessation outcomes.

Solutions of the Wheeler-Feynman equations with discontinuous velocities.

Science.gov (United States)

de Souza, Daniel Câmara; De Luca, Jayme

2015-01-01

We generalize Wheeler-Feynman electrodynamics with a variational boundary value problem for continuous boundary segments that might include velocity discontinuity points. Critical-point orbits must satisfy the Euler-Lagrange equations of the action functional at most points, which are neutral differential delay equations (the Wheeler-Feynman equations of motion). At velocity discontinuity points, critical-point orbits must satisfy the Weierstrass-Erdmann continuity conditions for the partial momenta and the partial energies. We study a special setup having the shortest time-separation between the (infinite-dimensional) boundary segments, for which case the critical-point orbit can be found using a two-point boundary problem for an ordinary differential equation. For this simplest setup, we prove that orbits can have discontinuous velocities. We construct a numerical method to solve the Wheeler-Feynman equations together with the Weierstrass-Erdmann conditions and calculate some numerical orbits with discontinuous velocities. We also prove that the variational boundary value problem has a unique solution depending continuously on boundary data, if the continuous boundary segments have velocity discontinuities along a reduced local space.

The optimal time of discontinuing methimazole before radioiodine therapy

International Nuclear Information System (INIS)

Moosavi, Z.; Zakavi, R.

2001-01-01

Hyperthyroidism is a common disease and one of the best methods for its treatment is radioiodine therapy with Treatment with antithyroid drugs brings patients to euthyroidism before radioiodine therapy. Antithyroid drugs should be discontinued before radioiodine therapy to increase thyroid uptake. The purpose of this study was to determine the optimal time of methimazole discontinuation. One hundred eighty four patients, who were referred for radioiodine therapy were classified in 3 groups according to the duration of methimazole discontinuation before thyroid uptake (RAIU) measurement. Group 1,2 and 3 were patients who discontinued methimazole (48-72 h rs), (72-120 h rs) and more than 120 h rs before RAIU measurement, respectively. Mean thyroid uptake in group 1, 2 and 3 was (64±151.1%), (60.1±14.1%) and (59.3±12.8), respectively. No significant difference was noted in thyroid uptake between these groups (F= 1.83, P<0.16). This study shows that 48-72 h rs of methimazole discontinuation before radioiodine therapy is enough and longer term abstention is not associated with higher uptake

Minimizers with discontinuous velocities for the electromagnetic variational method

International Nuclear Information System (INIS)

De Luca, Jayme

2010-01-01

The electromagnetic two-body problem has neutral differential delay equations of motion that, for generic boundary data, can have solutions with discontinuous derivatives. If one wants to use these neutral differential delay equations with arbitrary boundary data, solutions with discontinuous derivatives must be expected and allowed. Surprisingly, Wheeler-Feynman electrodynamics has a boundary value variational method for which minimizer trajectories with discontinuous derivatives are also expected, as we show here. The variational method defines continuous trajectories with piecewise defined velocities and accelerations, and electromagnetic fields defined by the Euler-Lagrange equations on trajectory points. Here we use the piecewise defined minimizers with the Lienard-Wierchert formulas to define generalized electromagnetic fields almost everywhere (but on sets of points of zero measure where the advanced/retarded velocities and/or accelerations are discontinuous). Along with this generalization we formulate the generalized absorber hypothesis that the far fields vanish asymptotically almost everywhere and show that localized orbits with far fields vanishing almost everywhere must have discontinuous velocities on sewing chains of breaking points. We give the general solution for localized orbits with vanishing far fields by solving a (linear) neutral differential delay equation for these far fields. We discuss the physics of orbits with discontinuous derivatives stressing the differences to the variational methods of classical mechanics and the existence of a spinorial four-current associated with the generalized variational electrodynamics.

The challenge of pelvic discontinuity: cup-cage reconstruction does better than conventional cages in mid-term.

Science.gov (United States)

Abolghasemian, M; Tangsaraporn, S; Drexler, M; Barbuto, R; Backstein, D; Safir, O; Kuzyk, P; Gross, A

2014-02-01

The use of ilioischial cage reconstruction for pelvic discontinuity has been replaced by the Trabecular Metal (Zimmer, Warsaw, Indiana) cup-cage technique in our institution, due to the unsatisfactory outcome of using a cage alone in this situation. We report the outcome of 26 pelvic discontinuities in 24 patients (20 women and four men, mean age 65 years (44 to 84)) treated by the cup-cage technique at a mean follow-up of 82 months (12 to 113) and compared them with a series of 19 pelvic discontinuities in 19 patients (18 women and one man, mean age 70 years (42 to 86)) treated with a cage at a mean follow-up of 69 months (1 to 170). The clinical and radiological outcomes as well as the survivorship of the groups were compared. In all, four of the cup-cage group (15%) and 13 (68%) of the cage group failed due to septic or aseptic loosening. The seven-year survivorship was 87.2% (95% confidence interval (CI) 71 to 103) for the cup-cage group and 49.9% (95% CI 15 to 84) for the cage-alone group (p = 0.009). There were four major complications in the cup-cage group and nine in the cage group. Radiological union of the discontinuity was found in all successful cases in the cup-cage group and three of the successful cage cases. Three hips in the cup-cage group developed early radiological migration of the components, which stabilised with a successful outcome. Cup-cage reconstruction is a reliable technique for treating pelvic discontinuity in mid-term follow-up and is preferred to ilioischial cage reconstruction. If the continuity of the bone graft at the discontinuity site is not disrupted, early migration of the components does not necessarily result in failure.

Resistance to discontinuing breast cancer screening in older women: A qualitative study.

Science.gov (United States)

Housten, Ashley J; Pappadis, Monique R; Krishnan, Shilpa; Weller, Susan C; Giordano, Sharon H; Bevers, Therese B; Volk, Robert J; Hoover, Diana S

2018-06-01

Screening mammography is associated with reduced breast cancer-specific mortality; however, among older women, evidence suggests that the potential harms of screening may outweigh the benefits. We used a qualitative approach to examine the willingness of older women from different racial/ethnic groups to discontinue breast cancer screening. Women ≥70 years of age who reported having a screening mammogram in the past 3 years and/or reported that they intended to continue screening in the future were recruited for in-depth interviews. Participants who intended to continue screening were asked to describe how the following hypothetical scenarios would impact a decision to discontinue screening: health concerns or limited life expectancy, a physician's recommendation to discontinue, reluctance to undergo treatment, and recommendations from experts or governmental panels to stop screening. Semi-structured, face-to-face interviews were audio-recorded. Data coding and analysis followed inductive and deductive approaches. Regardless of the scenario, participants (n = 29) expressed a strong intention to continue screening. Based on the hypothetical physician recommendations, intentions to continue screening appeared to remain strong. They did not envision a change in their health status that would lead them to discontinue screening and were skeptical of expert/government recommendations. There were no differences observed according to age, race/ethnicity, or education. Among older women who planned to continue screening, intentions to continue breast cancer screening appear to be highly resilient and resistant to recommendations from physicians or expert/government panels. Copyright © 2018 John Wiley & Sons, Ltd.

Discontinuation risk comparison among 'real-world' newly anticoagulated atrial fibrillation patients

DEFF Research Database (Denmark)

Lip, Gregory Y H; Pan, Xianying; Kamble, Shital

2018-01-01

Discontinuation of oral anticoagulants may expose non-valvular atrial fibrillation (NVAF) patients to an increased risk of stroke. This study describes the real-world discontinuation rates and compared the risk of drug discontinuation among NVAF patients initiating apixaban, warfarin, dabigatran,...

Seismic wave propagation in fractured media: A discontinuous Galerkin approach

KAUST Repository

De Basabe, Jonás D.

2011-01-01

We formulate and implement a discontinuous Galekin method for elastic wave propagation that allows for discontinuities in the displacement field to simulate fractures or faults using the linear- slip model. We show numerical results using a 2D model with one linear- slip discontinuity and different frequencies. The results show a good agreement with analytic solutions. © 2011 Society of Exploration Geophysicists.

The effect of manufacturing conditions on discontinuity population and fatigue fracture behavior in carbon/epoxy composites

Science.gov (United States)

Hakim, Issa; Laquai, Rene; Walter, David; Mueller, Bernd; Graja, Paul; Meyendorf, Norbert; Donaldson, Steven

2017-02-01

Carbon fiber composites have been increasingly used in aerospace, military, sports, automotive and other fields due to their excellent properties, including high specific strength, high specific modulus, corrosion resistance, fatigue resistance, and low thermal expansion coefficient. Interlaminar fracture is a serious failure mode leading to a loss in composite stiffness and strength. Discontinuities formed during manufacturing process degrade the fatigue life and interlaminar fracture resistance of the composite. In his study, three approaches were implemented and their results were correlated to quantify discontinuities effecting static and fatigue interlaminar fracture behavior of carbon fiber composites. Samples were fabricated by hand layup vacuum bagging manufacturing process under three different vacuum levels, indicated High (-686 mmHg), Moderate (-330 mmHg) and Poor (0 mmHg). Discontinuity content was quantified through-thickness by destructive and nondestructive techniques. Eight different NDE methods were conducted including imaging NDE methods: X-Ray laminography, ultrasonic, high frequency eddy current, pulse thermography, pulse phase thermography and lock-in-thermography, and averaging NDE techniques: X-Ray refraction and thermal conductivity measurements. Samples were subsequently destructively serial sectioned through-thickness into several layers. Both static and fatigue interlaminar fracture behavior under Mode I were conducted. The results of several imaging NDE methods revealed the trend in percentages of discontinuity. However, the results of averaging NDE methods showed a clear correlation since they gave specific values of discontinuity through-thickness. Serial sectioning exposed the composite's internal structure and provided a very clear idea about the type, shape, size, distribution and location of most discontinuities included. The results of mechanical testing showed that discontinuities lead to a decrease in Mode I static interlaminar

Derivative discontinuity with localized Hartree-Fock potential

Energy Technology Data Exchange (ETDEWEB)

Nazarov, V. U. [Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan (China); Vignale, G. [Department of Physics, University of Missouri-Columbia, Columbia, Missouri 65211 (United States)

2015-08-14

The localized Hartree-Fock potential has proven to be a computationally efficient alternative to the optimized effective potential, preserving the numerical accuracy of the latter and respecting the exact properties of being self-interaction free and having the correct −1/r asymptotics. In this paper we extend the localized Hartree-Fock potential to fractional particle numbers and observe that it yields derivative discontinuities in the energy as required by the exact theory. The discontinuities are numerically close to those of the computationally more demanding Hartree-Fock method. Our potential enjoys a “direct-energy” property, whereby the energy of the system is given by the sum of the single-particle eigenvalues multiplied by the corresponding occupation numbers. The discontinuities c{sub ↑} and c{sub ↓} of the spin-components of the potential at integer particle numbers N{sub ↑} and N{sub ↓} satisfy the condition c{sub ↑}N{sub ↑} + c{sub ↓}N{sub ↓} = 0. Thus, joining the family of effective potentials which support a derivative discontinuity, but being considerably easier to implement, the localized Hartree-Fock potential becomes a powerful tool in the broad area of applications in which the fundamental gap is an issue.

Partial inertia induces additional phase transition in the majority vote model.

Science.gov (United States)

Harunari, Pedro E; de Oliveira, M M; Fiore, C E

2017-10-01

Explosive (i.e., discontinuous) transitions have aroused great interest by manifesting in distinct systems, such as synchronization in coupled oscillators, percolation regime, absorbing phase transitions, and more recently, the majority-vote model with inertia. In the latter, the model rules are slightly modified by the inclusion of a term depending on the local spin (an inertial term). In such a case, Chen et al. [Phys Rev. E 95, 042304 (2017)2470-004510.1103/PhysRevE.95.042304] have found that relevant inertia changes the nature of the phase transition in complex networks, from continuous to discontinuous. Here we give a further step by embedding inertia only in vertices with degree larger than a threshold value 〈k〉k^{*}, 〈k〉 being the mean system degree and k^{*} the fraction restriction. Our results, from mean-field analysis and extensive numerical simulations, reveal that an explosive transition is presented in both homogeneous and heterogeneous structures for small and intermediate k^{*}'s. Otherwise, a large restriction can sustain a discontinuous transition only in the heterogeneous case. This shares some similarities with recent results for the Kuramoto model [Phys. Rev. E 91, 022818 (2015)PLEEE81539-375510.1103/PhysRevE.91.022818]. Surprisingly, intermediate restriction and large inertia are responsible for the emergence of an extra phase, in which the system is partially synchronized and the classification of phase transition depends on the inertia and the lattice topology. In this case, the system exhibits two phase transitions.

Convergent piecewise affine systems : analysis and design Part II: discontinuous case

NARCIS (Netherlands)

Pavlov, A.V.; Pogromski, A.Y.; Wouw, van de N.; Nijmeijer, H.; Rooda, J.E.

2005-01-01

In this paper convergence properties of piecewise affine (PWA) systems with discontinuous right-hand sides are studied. It is shown that for discontinuous PWA systems existence of a common quadratic Lyapunov function is not sufficient for convergence. For discontinuous bimodal PWA systems necessary

Stacking and discontinuous buffers in capillary zone electrophoresis.

Science.gov (United States)

Shihabi, Z K

2000-08-01

Discontinuous buffers for capillary zone electrophoresis (CZE) can be used under less rigid conditions compared to those for isotachophoresis for stacking. They can be prepared simply by modifying the sample itself, either by addition of small inorganic ions, low conductivity diluents, or both, and also by adjusting its pH, meanwhile injecting a large volume on the capillary. Zwitterionic and organic-based buffers such as triethanolamine and tris(hydroxymethyl)aminomethane (Tris) are well suited for stacking due to their low conductivity, provided the buffer is discontinuous as demonstrated here. A simple mechanism based on discontinuous buffers is described to explain many of the observed stacking types in CZE, pointing out the many similarities to transient isotachophoresis.

Utilizing Cognitive-Behavioral Therapy for Insomnia to Facilitate Discontinuation of Sleep Medication in Chronic Insomnia Patients

Directory of Open Access Journals (Sweden)

Jason Ong

2012-04-01

Full Text Available Many chronic insomnia patients use sleep medication well beyond the recommended duration, and patients who are hypnotic-dependent encounter several challenges when attempting to discontinue. The current article presents these challenges and reviews studies that have added cognitive-behavioral therapy for insomnia (CBTI to a gradual tapering program to facilitate discontinuation of hypnotic medication in chronic insomnia patients. The current literature provides substantial support for using CBTI to facilitate discontinuation of hypnotic medication in chronic insomnia patients. Across several randomized clinical trials, the majority of the findings indicate that using CBTI, delivered by a therapist or self-help, along with a supervised or gradual tapering program is superior to tapering only or CBTI only in terms of medication discontinuation. Although these results are promising, it should be noted that the long-term evidence is more equivocal, as over 40% of patients relapse in the need for sleep medication within 2 years, which may highlight the importance of adding follow-up booster sessions in hypnotic-dependent insomniacs. These findings indicate that rather than choosing between CBT and hypnotic medication, clinicians might be better served using both treatment modalities to optimize the relative strengths of each treatment. Such an approach represents a more modern view of treating chronic insomnia patients by using both pharmacological and non-pharmacological tools.

Efficient methodology for multibody simulations with discontinuous changes in system definition

International Nuclear Information System (INIS)

Mukherjee, Rudranarayan M.; Anderson, Kurt S.

2007-01-01

A new method is presented for accurately and efficiently simulating multi-scale multibody systems with discontinuous changes in system definitions as encountered in adaptive switching between models with different resolutions as well as models with different system topologies. An example of model resolution change is a transition of a system from a discrete particle model to a reduced order articulated multi-rigid body model. The discontinuous changes in system definition may be viewed as an instantaneous change (release or impulsive application of) the system constraints. The method uses a spatial impulse-momentum formulation in a divide and conquer scheme. The approach utilizes a hierarchic assembly-disassembly process by traversing the system topology in a binary tree map to solve for the jumps in the system generalized speeds and the constraint impulsive loads in linear and logarithmic cost in serial and parallel implementations, respectively. The method is applicable for systems in serial chain as well as kinematical loop topologies. The coupling between the unilateral and bilateral constraints is handled efficiently through the use of kinematic joint definitions. The equations of motion for the system are produced in a hierarchic sub-structured form. This has the advantage that changes in sub-structure definitions/models results in a change to the system equations only within the associated sub-structure. This allows for significant changes in model types and definitions without having to reformulate the equations for the whole system

On U- and V-statistics for discontinuous Itô semimartingale

DEFF Research Database (Denmark)

Podolskij, Mark; Schmidt, Christian; Vetter, Mathias

In this paper we examine the asymptotic theory for U-statistics and V-statistics of discontinuous Itô semimartingales that are observed at high frequency. For different types of kernel functions we show laws of large numbers and associated stable central limit theorems. In most of the cases the l...... the limiting process will be conditionally centered Gaussian. The structure of the kernel function determines whether the jump and/or the continuous part of the semimartingale contribute to the limit....

The myth of DSM's invention of new categories of disorder: Houts's diagnostic discontinuity thesis disconfirmed.

Science.gov (United States)

Wakefield, J C

2001-05-01

Houts (2001) argues that increases in DSM diagnostic categories are due to the invention of new disorders that are discontinuous with old conceptions of disorder and would not have been previously diagnosed. He maintains that DSM category increases are not comparable in nature to ICD category increases, which are mainly refinements of recognized disorders. I survey categories of disorder introduced after DSM-II and assess whether they are discontinuous with old concepts and categories of disorder. Candidate categories are identified from: Houts and Follette (1998), Mentalism, mechanisms, and medical analogues: Reply to Wakefield. Journal of Consulting and Clinical Psychology; Kutchins and Kirk (1997) Making us crazy: DSM: The psychiatric bible and the creation of mental disorders. New York: Free Press; and my own list. The result is that virtually none of the candidate categories are invented, discontinuous categories. In almost every case, the newly labeled conditions were considered disorders at the time of DSM-II and would have been diagnosed under DSM-II categories. I also reexamine DSM-IV sleep disorder categories, which Houts claims are discontinuous with past diagnostic conceptions. The result is that all DSM-IV sleep disorders were recognized as disorders at the time of DSM-II, and most were recognized as mental disorders. I conclude that DSM category increases are comparable in nature to ICD category increases, and that the invention-of-disorder account cannot explain the vast majority of such increases.

Waiting-time distributions of magnetic discontinuities: Clustering or Poisson process?

International Nuclear Information System (INIS)

Greco, A.; Matthaeus, W. H.; Servidio, S.; Dmitruk, P.

2009-01-01

Using solar wind data from the Advanced Composition Explorer spacecraft, with the support of Hall magnetohydrodynamic simulations, the waiting-time distributions of magnetic discontinuities have been analyzed. A possible phenomenon of clusterization of these discontinuities is studied in detail. We perform a local Poisson's analysis in order to establish if these intermittent events are randomly distributed or not. Possible implications about the nature of solar wind discontinuities are discussed.

Preparation and Mechanical Properties of Aligned Discontinuous Carbon Fiber Composites

OpenAIRE

DENG Hua; GAO Junpeng; BAO Jianwen

2018-01-01

Aligned discontinuous carbon fiber composites were fabricated from aligned discontinuous carbon fiber prepreg, which was prepared from continuous carbon fiber prepreg via mechanical high-frequency cutting. The internal quality and mechanical properties were characterized and compared with continuous carbon fiber composites. The results show that the internal quality of the aligned discontinuous carbon fiber composites is fine and the mechanical properties have high retention rate after the fi...

Risk factors for early treatment discontinuation in patients with obsessive-compulsive disorder

Directory of Open Access Journals (Sweden)

Juliana Belo Diniz

2011-01-01

Full Text Available INTRODUCTION: In obsessive-compulsive disorder, early treatment discontinuation can hamper the effectiveness of first-line treatments. OBJECTIVE: This study aimed to investigate the clinical correlates of early treatment discontinuation among obsessive-compulsive disorder patients. METHODS: A group of patients who stopped taking selective serotonin reuptake inhibitors (SSRIs or stopped participating in cognitive behavioral therapy before completion of the first twelve weeks (total n = 41; n = 16 for cognitive behavioral therapy and n = 25 for SSRIs were compared with a paired sample of compliant patients (n = 41. Demographic and clinical characteristics were obtained at baseline using structured clinical interviews. Chisquare and Mann-Whitney tests were used when indicated. Variables presenting a p value <0.15 for the difference between groups were selected for inclusion in a logistic regression analysis that used an interaction model with treatment dropout as the response variable. RESULTS: Agoraphobia was only present in one (2.4% patient who completed the twelve-week therapy, whereas it was present in six (15.0% patients who dropped out (p = 0.044. Social phobia was present in eight (19.5% patients who completed the twelve-week therapy and eighteen (45% patients who dropped out (p = 0.014. Generalized anxiety disorder was present in eight (19.5% patients who completed the twelve-week therapy and twenty (50% dropouts (p = 0.004, and somatization disorder was not present in any of the patients who completed the twelveweek therapy; however, it was present in six (15% dropouts (p = 0.010. According to the logistic regression model, treatment modality (p = 0.05, agoraphobia, the Brown Assessment of Beliefs Scale scores (p = 0.03 and the Beck Anxiety Inventory (p = 0.02 scores were significantly associated with the probability of treatment discontinuation irrespective of interactions with other variables. DISCUSSION AND CONCLUSION: Early treatment

Probability of major depression diagnostic classification using semi-structured versus fully structured diagnostic interviews.

Science.gov (United States)

Levis, Brooke; Benedetti, Andrea; Riehm, Kira E; Saadat, Nazanin; Levis, Alexander W; Azar, Marleine; Rice, Danielle B; Chiovitti, Matthew J; Sanchez, Tatiana A; Cuijpers, Pim; Gilbody, Simon; Ioannidis, John P A; Kloda, Lorie A; McMillan, Dean; Patten, Scott B; Shrier, Ian; Steele, Russell J; Ziegelstein, Roy C; Akena, Dickens H; Arroll, Bruce; Ayalon, Liat; Baradaran, Hamid R; Baron, Murray; Beraldi, Anna; Bombardier, Charles H; Butterworth, Peter; Carter, Gregory; Chagas, Marcos H; Chan, Juliana C N; Cholera, Rushina; Chowdhary, Neerja; Clover, Kerrie; Conwell, Yeates; de Man-van Ginkel, Janneke M; Delgadillo, Jaime; Fann, Jesse R; Fischer, Felix H; Fischler, Benjamin; Fung, Daniel; Gelaye, Bizu; Goodyear-Smith, Felicity; Greeno, Catherine G; Hall, Brian J; Hambridge, John; Harrison, Patricia A; Hegerl, Ulrich; Hides, Leanne; Hobfoll, Stevan E; Hudson, Marie; Hyphantis, Thomas; Inagaki, Masatoshi; Ismail, Khalida; Jetté, Nathalie; Khamseh, Mohammad E; Kiely, Kim M; Lamers, Femke; Liu, Shen-Ing; Lotrakul, Manote; Loureiro, Sonia R; Löwe, Bernd; Marsh, Laura; McGuire, Anthony; Mohd Sidik, Sherina; Munhoz, Tiago N; Muramatsu, Kumiko; Osório, Flávia L; Patel, Vikram; Pence, Brian W; Persoons, Philippe; Picardi, Angelo; Rooney, Alasdair G; Santos, Iná S; Shaaban, Juwita; Sidebottom, Abbey; Simning, Adam; Stafford, Lesley; Sung, Sharon; Tan, Pei Lin Lynnette; Turner, Alyna; van der Feltz-Cornelis, Christina M; van Weert, Henk C; Vöhringer, Paul A; White, Jennifer; Whooley, Mary A; Winkley, Kirsty; Yamada, Mitsuhiko; Zhang, Yuying; Thombs, Brett D

2018-06-01

Different diagnostic interviews are used as reference standards for major depression classification in research. Semi-structured interviews involve clinical judgement, whereas fully structured interviews are completely scripted. The Mini International Neuropsychiatric Interview (MINI), a brief fully structured interview, is also sometimes used. It is not known whether interview method is associated with probability of major depression classification.AimsTo evaluate the association between interview method and odds of major depression classification, controlling for depressive symptom scores and participant characteristics. Data collected for an individual participant data meta-analysis of Patient Health Questionnaire-9 (PHQ-9) diagnostic accuracy were analysed and binomial generalised linear mixed models were fit. A total of 17 158 participants (2287 with major depression) from 57 primary studies were analysed. Among fully structured interviews, odds of major depression were higher for the MINI compared with the Composite International Diagnostic Interview (CIDI) (odds ratio (OR) = 2.10; 95% CI = 1.15-3.87). Compared with semi-structured interviews, fully structured interviews (MINI excluded) were non-significantly more likely to classify participants with low-level depressive symptoms (PHQ-9 scores ≤6) as having major depression (OR = 3.13; 95% CI = 0.98-10.00), similarly likely for moderate-level symptoms (PHQ-9 scores 7-15) (OR = 0.96; 95% CI = 0.56-1.66) and significantly less likely for high-level symptoms (PHQ-9 scores ≥16) (OR = 0.50; 95% CI = 0.26-0.97). The MINI may identify more people as depressed than the CIDI, and semi-structured and fully structured interviews may not be interchangeable methods, but these results should be replicated.Declaration of interestDrs Jetté and Patten declare that they received a grant, outside the submitted work, from the Hotchkiss Brain Institute, which was jointly funded by the Institute and Pfizer. Pfizer was the

Mechanical components: fabrication of major reactor structures

International Nuclear Information System (INIS)

Nicholson, S.

1985-01-01

The paper examines the validity of criticisms of quality assurance of mechanical plant and welded products within major reactor structures, taking into account experience gained on the AGR's. Various constructive recommendations are made aimed at furthering the objectives of quality assurance in the nuclear industry and making it more cost-effective. Current levels of quality related costs in the fabrication industry are provided as a basis for discussion. (U.K.)

A non-conventional discontinuous Lagrangian for viscous flow

Science.gov (United States)

Marner, F.

2017-01-01

Drawing an analogy with quantum mechanics, a new Lagrangian is proposed for a variational formulation of the Navier–Stokes equations which to-date has remained elusive. A key feature is that the resulting Lagrangian is discontinuous in nature, posing additional challenges apropos the mathematical treatment of the related variational problem, all of which are resolvable. In addition to extending Lagrange's formalism to problems involving discontinuous behaviour, it is demonstrated that the associated equations of motion can self-consistently be interpreted within the framework of thermodynamics beyond local equilibrium, with the limiting case recovering the classical Navier–Stokes equations. Perspectives for applying the new formalism to discontinuous physical phenomena such as phase and grain boundaries, shock waves and flame fronts are provided. PMID:28386415

Characterization of discontinuities in an argillaceous medium (Tournemire site): key questions related to safety assessment of radioactive waste disposal

Energy Technology Data Exchange (ETDEWEB)

Cabrera Nunez, J. [CEA Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire

2001-07-01

The safety assessment of deep radioactive waste disposal in argillaceous medium concerns the evaluation of the possibilities and transfer processes through this geological barrier. Generally, this material is characterized by a very low permeability. However, faults and fractures may affect this medium and consequently it is important to analyse the transfer possibilities along these discontinuities. The first phase of this evaluation is the detection or survey of the fractures, and the second one is the evaluation of their hydraulic properties. A discontinuity is not a synonymous of fluid transfer, which in turn may be inhomogeneous along the same fracture. The well-compacted Tournemire argillaceous medium (argilites and marls) is affected by some faults and fractures of natural (tectonic) and artificial (excavation) origin. The natural fractures are of different scales: major regional faults that limit blocks, secondary fault and fractured zones that affect the blocks, and local fractures and micro-fractures. These discontinuities are studied from the surface analyses, transversal boreholes and drifts. Geophysical methods are tested to detect these discontinuities to different scales. The present-day fluids are shown in some fractured sectors that allow us to analyse the possibilities of fluid transfer along these discontinuities. The fracture analyses show that permeability or transmissivity properties may change along the discontinuities. A decametric fluid transfer is shown along some fractures; however, their integration in a larger scale is not yet analysed. It is necessary to understand how the transfer in the near field may be connected to the possible far field transfer, or these transfers are not possible through the argillaceous medium. (author)

Characterization of discontinuities in an argillaceous medium (Tournemire site): key questions related to safety assessment of radioactive waste disposal

International Nuclear Information System (INIS)

Cabrera Nunez, J.

2001-01-01

The safety assessment of deep radioactive waste disposal in argillaceous medium concerns the evaluation of the possibilities and transfer processes through this geological barrier. Generally, this material is characterized by a very low permeability. However, faults and fractures may affect this medium and consequently it is important to analyse the transfer possibilities along these discontinuities. The first phase of this evaluation is the detection or survey of the fractures, and the second one is the evaluation of their hydraulic properties. A discontinuity is not a synonymous of fluid transfer, which in turn may be inhomogeneous along the same fracture. The well-compacted Tournemire argillaceous medium (argilites and marls) is affected by some faults and fractures of natural (tectonic) and artificial (excavation) origin. The natural fractures are of different scales: major regional faults that limit blocks, secondary fault and fractured zones that affect the blocks, and local fractures and micro-fractures. These discontinuities are studied from the surface analyses, transversal boreholes and drifts. Geophysical methods are tested to detect these discontinuities to different scales. The present-day fluids are shown in some fractured sectors that allow us to analyse the possibilities of fluid transfer along these discontinuities. The fracture analyses show that permeability or transmissivity properties may change along the discontinuities. A decametric fluid transfer is shown along some fractures; however, their integration in a larger scale is not yet analysed. It is necessary to understand how the transfer in the near field may be connected to the possible far field transfer, or these transfers are not possible through the argillaceous medium. (author)

News and views in discontinuous phase transitions

Science.gov (United States)

Nagler, Jan

2014-03-01

Recent progress in the theory of discontinuous percolation allow us to better understand the the sudden emergence of large-scale connectedness both in networked systems and on the lattice. We analytically study mechanisms for the amplification of critical fluctuations at the phase transition point, non-self-averaging and power law fluctuations. A single event analysis allow to establish criteria for discontinuous percolation transitions, even on the high-dimensional lattice. Some applications such as salad bowl percolation, and inverse fragmentation are discussed.

Dynamic stability and failure modes of slopes in discontinuous rock mass

International Nuclear Information System (INIS)

Shimizu, Yasuhiro; Aydan, O.; Ichikawa, Yasuaki; Kawamoto, Toshikazu.

1988-01-01

The stability of rock slopes during earthquakes are of great concern in rock engineering works such as highway, dam, and nuclear power station constructions. As rock mass in nature is usually discontinuous, the stability of rock slopes will be geverned by the spatial distribution of discontinuities in relation with the geometry of slope and their mechanical properties rather than the rock element. The authors have carried out some model tests on discontinuous rock slopes using three different model tests techniques in order to investigate the dynamic behaviour and failure modes of the slopes in discontinuous rock mass. This paper describes the findings and observations made on model rock slopes with various discontinuity patterns and slope geometry. In addition some stability criterions are developed and the calculated results are compared with those of experiments. (author)

Discontinuity of maximum entropy inference and quantum phase transitions

International Nuclear Information System (INIS)

Chen, Jianxin; Ji, Zhengfeng; Yu, Nengkun; Zeng, Bei; Li, Chi-Kwong; Poon, Yiu-Tung; Shen, Yi; Zhou, Duanlu

2015-01-01

In this paper, we discuss the connection between two genuinely quantum phenomena—the discontinuity of quantum maximum entropy inference and quantum phase transitions at zero temperature. It is shown that the discontinuity of the maximum entropy inference of local observable measurements signals the non-local type of transitions, where local density matrices of the ground state change smoothly at the transition point. We then propose to use the quantum conditional mutual information of the ground state as an indicator to detect the discontinuity and the non-local type of quantum phase transitions in the thermodynamic limit. (paper)

MHD intermediate shock discontinuities: Pt. 1

International Nuclear Information System (INIS)

Kennel, C.F.; Blandford, R.D.; Coppi, P.

1989-01-01

Recent numerical investigations have focused attention once more on the role of intermediate shocks in MHD. Four types of intermediate shock are identified using a graphical representation of the MHD Rankine-Hugoniot conditions. This same representation can be used to exhibit the close relationship of intermediate shocks to switch-on shocks and rotational discontinuities. The conditions under which intermediate discontinuities can be found are elucidated. The variations in velocity, pressure, entropy and magnetic-field jumps with upstream parameters in intermediate shocks are exhibited graphically. The evolutionary arguments traditionally advanced against intermediate shocks may fail because the equations of classical MHD are not strictly hyperbolic. (author)

Aberration changes of the corneal anterior surface following discontinued use of rigid gas permeable contact lenses.

Science.gov (United States)

Yu, Qing; Wu, Jiang-Xiu; Zhang, He-Ning; Ye, Sheng; Dong, Shi-Qi; Zhang, Chen-Hao

2013-01-01

the cornea. Changes to 2(nd)- and 3(rd)-order aberrations (including Z3, Z4, Z5, Z6, Z7, and Z8) were more significant. Following discontinued use of RGP contact lenses, the majority of lower order aberrations returned to original levels in a short period of time. During this process, a transient higher order aberration appeared, but all changes disappeared within 14 days after discontinued use of RGP contact lenses.

Traditional biomolecular structure determination by NMR spectroscopy allows for major errors

NARCIS (Netherlands)

Nabuurs, S.B.; Spronk, C.A.E.M.; Vuister, G.W.; Vriend, G.

2006-01-01

One of the major goals of structural genomics projects is to determine the three-dimensional structure of representative members of as many different fold families as possible. Comparative modeling is expected to fill the remaining gaps by providing structural models of homologs of the

Contribution of Strong Discontinuities to the Power Spectrum of the Solar Wind

International Nuclear Information System (INIS)

Borovsky, Joseph E.

2010-01-01

Eight and a half years of magnetic field measurements (2 22 samples) from the ACE spacecraft in the solar wind at 1 A.U. are analyzed. Strong (large-rotation-angle) discontinuities in the solar wind are collected and measured. An artificial time series is created that preserves the timing and amplitudes of the discontinuities. The power spectral density of the discontinuity series is calculated and compared with the power spectral density of the solar-wind magnetic field. The strong discontinuities produce a power-law spectrum in the ''inertial subrange'' with a spectral index near the Kolmogorov -5/3 index. The discontinuity spectrum contains about half of the power of the full solar-wind magnetic field over this ''inertial subrange.'' Warnings are issued about the significant contribution of discontinuities to the spectrum of the solar wind, complicating interpretation of spectral power and spectral indices.

Discontinuous Galerkin finite element methods for hyperbolic differential equations

NARCIS (Netherlands)

van der Vegt, Jacobus J.W.; van der Ven, H.; Boelens, O.J.; Boelens, O.J.; Toro, E.F.

2002-01-01

In this paper a suryey is given of the important steps in the development of discontinuous Galerkin finite element methods for hyperbolic partial differential equations. Special attention is paid to the application of the discontinuous Galerkin method to the solution of the Euler equations of gas

Clopidogrel discontinuation and platelet reactivity following coronary stenting

LENUS (Irish Health Repository)

2011-01-01

Summary. Aims: Antiplatelet therapy with aspirin and clopidogrel is recommended for 1 year after drug-eluting stent (DES) implantation or myocardial infarction. However, the discontinuation of antiplatelet therapy has become an important issue as recent studies have suggested a clustering of ischemic events within 90 days of clopidogrel withdrawal. The objective of this investigation was to explore the hypothesis that there is a transient ‘rebound’ increase in platelet reactivity within 3 months of clopidogrel discontinuation. Methods and Results: In this prospective study, platelet function was assessed in patients taking aspirin and clopidogrel for at least 1 year following DES implantation. Platelet aggregation was measured using a modification of light transmission aggregometry in response to multiple concentrations of adenosine diphosphate (ADP), epinephrine, arachidonic acid, thrombin receptor activating peptide and collagen. Clopidogrel was stopped and platelet function was reassessed 1 week, 1 month and 3 months later. Thirty-two patients on dual antiplatelet therapy were recruited. Discontinuation of clopidogrel increased platelet aggregation to all agonists, except arachidonic acid. Platelet aggregation in response to ADP (2.5, 5, 10, and 20 μm) and epinephrine (5 and 20 μm) was significantly increased at 1 month compared with 3 months following clopidogrel withdrawal. Thus, a transient period of increased platelet reactivity to both ADP and epinephrine was observed 1 month after clopidogrel discontinuation. Conclusions: This study demonstrates a transient increase in platelet reactivity 1 month after clopidogrel withdrawal. This phenomenon may, in part, explain the known clustering of thrombotic events observed after clopidogrel discontinuation. This observation requires confirmation in larger populations.

Variational Methods for Discontinuous Structures : Applications to Image Segmentation, Continuum Mechanics

CERN Document Server

Tomarelli, Franco

1996-01-01

In recent years many researchers in material science have focused their attention on the study of composite materials, equilibrium of crystals and crack distribution in continua subject to loads. At the same time several new issues in computer vision and image processing have been studied in depth. The understanding of many of these problems has made significant progress thanks to new methods developed in calculus of variations, geometric measure theory and partial differential equations. In particular, new technical tools have been introduced and successfully applied. For example, in order to describe the geometrical complexity of unknown patterns, a new class of problems in calculus of variations has been introduced together with a suitable functional setting: the free-discontinuity problems and the special BV and BH functions. The conference held at Villa Olmo on Lake Como in September 1994 spawned successful discussion of these topics among mathematicians, experts in computer science and material scientis...

Class of reconstructed discontinuous Galerkin methods in computational fluid dynamics

International Nuclear Information System (INIS)

Luo, Hong; Xia, Yidong; Nourgaliev, Robert

2011-01-01

A class of reconstructed discontinuous Galerkin (DG) methods is presented to solve compressible flow problems on arbitrary grids. The idea is to combine the efficiency of the reconstruction methods in finite volume methods and the accuracy of the DG methods to obtain a better numerical algorithm in computational fluid dynamics. The beauty of the resulting reconstructed discontinuous Galerkin (RDG) methods is that they provide a unified formulation for both finite volume and DG methods, and contain both classical finite volume and standard DG methods as two special cases of the RDG methods, and thus allow for a direct efficiency comparison. Both Green-Gauss and least-squares reconstruction methods and a least-squares recovery method are presented to obtain a quadratic polynomial representation of the underlying linear discontinuous Galerkin solution on each cell via a so-called in-cell reconstruction process. The devised in-cell reconstruction is aimed to augment the accuracy of the discontinuous Galerkin method by increasing the order of the underlying polynomial solution. These three reconstructed discontinuous Galerkin methods are used to compute a variety of compressible flow problems on arbitrary meshes to assess their accuracy. The numerical experiments demonstrate that all three reconstructed discontinuous Galerkin methods can significantly improve the accuracy of the underlying second-order DG method, although the least-squares reconstructed DG method provides the best performance in terms of both accuracy, efficiency, and robustness. (author)

Research progress on criteria for discontinuation of EGFR inhibitor therapy

Directory of Open Access Journals (Sweden)

Zhuang HQ

2012-10-01

Full Text Available Hong-qing Zhuang, Zhi-yong Yuan, Jun Wang, Ping Wang, Lu-jun Zhao, Bai-lin ZhangDepartment of Radiotherapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin Key Laboratory of Cancer Prevention and Therapy, Tianjin Lung Cancer Center, Tianjin, People's Republic of ChinaAbstract: The clinical success of the epidermal growth factor receptor (EGFR tyrosine kinase inhibitors (TKI as therapeutic agents has prompted great interest in their further development and clinical testing for a wide variety of malignancies. However, most studies have focused on the efficacy of TKI, and few studies have been done on the criteria for their discontinuation. The current standard for drug discontinuation is “until progression”, based on change in tumor size. However, tumor size is not related to the gene expression which determines the efficacy of TKI in the final analysis, and it is also difficult to make a thorough and correct prediction based on tumor size when the TKI is discontinued. Nevertheless, clinical evaluation of the criteria for TKI discontinuation is still in its early days. Some promising findings have started to emerge. With the improving knowledge of EGFR and its inhibitors, it is expected that the criteria for discontinuation of EGFR inhibitor therapy will become clearer.Keywords: epidermal growth factor receptor, drug discontinuation, acquired drug-resistance

Convergence Improvement of Response Matrix Method with Large Discontinuity Factors

International Nuclear Information System (INIS)

Yamamoto, Akio

2003-01-01

In the response matrix method, a numerical divergence problem has been reported when extremely small or large discontinuity factors are utilized in the calculations. In this paper, an alternative response matrix formulation to solve the divergence problem is discussed, and properties of iteration matrixes are investigated through eigenvalue analyses. In the conventional response matrix formulation, partial currents between adjacent nodes are assumed to be discontinuous, and outgoing partial currents are converted into incoming partial currents by the discontinuity factor matrix. Namely, the partial currents of the homogeneous system (i.e., homogeneous partial currents) are treated in the conventional response matrix formulation. In this approach, the spectral radius of an iteration matrix for the partial currents may exceed unity when an extremely small or large discontinuity factor is used. Contrary to this, an alternative response matrix formulation using heterogeneous partial currents is discussed in this paper. In the latter approach, partial currents are assumed to be continuous between adjacent nodes, and discontinuity factors are directly considered in the coefficients of a response matrix. From the eigenvalue analysis of the iteration matrix for the one-group, one-dimensional problem, the spectral radius for the heterogeneous partial current formulation does not exceed unity even if an extremely small or large discontinuity factor is used in the calculation; numerical stability of the alternative formulation is superior to the conventional one. The numerical stability of the heterogeneous partial current formulation is also confirmed by the two-dimensional light water reactor core analysis. Since the heterogeneous partial current formulation does not require any approximation, the converged solution exactly reproduces the reference solution when the discontinuity factors are directly derived from the reference calculation

Schroedinger propagation of initial discontinuities leads to divergence of moments

International Nuclear Information System (INIS)

Marchewka, A.; Schuss, Z.

2009-01-01

We show that the large phase expansion of the Schroedinger propagation of an initially discontinuous wave function leads to the divergence of average energy, momentum, and displacement, rendering them unphysical states. If initially discontinuous wave functions are considered to be approximations to continuous ones, the determinant of the spreading rate of these averages is the maximal gradient of the initial wave function. Therefore a dilemma arises between the inclusion of discontinuous wave functions in quantum mechanics and the requirement of finite moments.

Schroedinger propagation of initial discontinuities leads to divergence of moments

Energy Technology Data Exchange (ETDEWEB)

Marchewka, A., E-mail: avi.marchewka@gmail.co [Ruppin Academic Center, Emek-Hefer 40250 (Israel); Schuss, Z., E-mail: schuss@post.tau.ac.i [Department of Mathematics, Tel-Aviv University, Ramat-Aviv, 69978 Tel-Aviv (Israel)

2009-09-21

We show that the large phase expansion of the Schroedinger propagation of an initially discontinuous wave function leads to the divergence of average energy, momentum, and displacement, rendering them unphysical states. If initially discontinuous wave functions are considered to be approximations to continuous ones, the determinant of the spreading rate of these averages is the maximal gradient of the initial wave function. Therefore a dilemma arises between the inclusion of discontinuous wave functions in quantum mechanics and the requirement of finite moments.

Discontinuous Petrov–Galerkin method with optimal test functions for thin-body problems in solid mechanics

KAUST Repository

Niemi, Antti H.

2011-02-01

We study the applicability of the discontinuous Petrov-Galerkin (DPG) variational framework for thin-body problems in structural mechanics. Our numerical approach is based on discontinuous piecewise polynomial finite element spaces for the trial functions and approximate, local computation of the corresponding \\'optimal\\' test functions. In the Timoshenko beam problem, the proposed method is shown to provide the best approximation in an energy-type norm which is equivalent to the L2-norm for all the unknowns, uniformly with respect to the thickness parameter. The same formulation remains valid also for the asymptotic Euler-Bernoulli solution. As another one-dimensional model problem we consider the modelling of the so called basic edge effect in shell deformations. In particular, we derive a special norm for the test space which leads to a robust method in terms of the shell thickness. Finally, we demonstrate how a posteriori error estimator arising directly from the discontinuous variational framework can be utilized to generate an optimal hp-mesh for resolving the boundary layer. © 2010 Elsevier B.V.

Forensic Excavation of Rock Masses: A Technique to Investigate Discontinuity Persistence

Science.gov (United States)

Shang, J.; Hencher, S. R.; West, L. J.; Handley, K.

2017-11-01

True persistence of rock discontinuities (areas with insignificant tensile strength) is an important factor controlling the engineering behaviour of fractured rock masses, but is extremely difficult to quantify using current geological survey methodologies, even where there is good rock exposure. Trace length as measured in the field or using remote measurement devices is actually only broadly indicative of persistence for rock engineering practice and numerical modelling. Visible traces of discontinuities are treated as if they were open fractures within rock mass classifications, despite many such traces being non-persistent and actually retaining considerable strength. The common assumption of 100% persistence, based on trace length, is generally extremely conservative in terms of strength and stiffness, but not always so and may lead to a wrong prediction of failure mechanism or of excavatability. Assuming full persistence would give hopelessly incorrect predictions of hydraulic conductivity. A new technique termed forensic excavation of rock masses is introduced, as a procedure for directly investigating discontinuity persistence. This technique involves non-explosive excavation of rock masses by injecting an expansive chemical splitter along incipient discontinuities. On expansion, the splitter causes the incipient traces to open as true joints. Experiments are described in which near-planar rock discontinuities, through siltstone and sandstone, were opened up by injecting the splitter into holes drilled along the lines of visible traces of the discontinuities in the laboratory and in the field. Once exposed the surfaces were examined to investigate the pre-existing persistence characteristics of the incipient discontinuities. One conclusion from this study is that visible trace length of a discontinuity can be a poor indicator of true persistence (defined for a fracture area with negligible tensile strength). An observation from this series of experiments

The effect of discontinuities on the corrosion behaviour of copper canisters

International Nuclear Information System (INIS)

King, F.

2004-03-01

Discontinuities may remain in the weld region of copper canisters following the final closure welding and inspection procedures. Although the shell of the copper canister is expected to exhibit excellent corrosion properties in the repository environment, the question remains what impact these discontinuities might have on the long-term performance and service life of the canister. A review of the relevant corrosion literature has been carried out and an expert opinion of the impact of these discontinuities on the canister lifetime has been developed. Since the amount of oxidant in the repository is limited and the maximum wall penetration is expected to be 2 O/Cu(OH) 2 film at a critical electrochemical potential determines where and when pits initiate, not the presence of pit-shaped surface discontinuities. The factors controlling pit growth and death are well understood. There is evidence for a maximum pit radius for copper in chloride solutions, above which the small anodic: cathodic surface area ratio required for the formation of deep pits cannot be sustained. This maximum pit radius is of the order of 0.1-0.5 mm. Surface discontinuities larger than this size are unlikely to propagate as pits, and pits generated from smaller discontinuities will die once they reach this maximum size. Death of propagating pits will be compounded by the decrease in oxygen flux to the canister as the repository environment becomes anoxic. Surface discontinuities could impact the SCC behaviour either through their effect on the local environment or via stress concentration or intensification. There is no evidence that surface discontinuities will affect the initiation of SCC by ennoblement of the corrosion potential or the formation of locally aggressive conditions. Stress concentration at pits could lead to crack initiation under some circumstances, but the stress intensity factor for the resultant cracks, or for pre-existing crack-like discontinuities, will be smaller than the

Automatic extraction of discontinuity orientation from rock mass surface 3D point cloud

Science.gov (United States)

Chen, Jianqin; Zhu, Hehua; Li, Xiaojun

2016-10-01

This paper presents a new method for extracting discontinuity orientation automatically from rock mass surface 3D point cloud. The proposed method consists of four steps: (1) automatic grouping of discontinuity sets using an improved K-means clustering method, (2) discontinuity segmentation and optimization, (3) discontinuity plane fitting using Random Sample Consensus (RANSAC) method, and (4) coordinate transformation of discontinuity plane. The method is first validated by the point cloud of a small piece of a rock slope acquired by photogrammetry. The extracted discontinuity orientations are compared with measured ones in the field. Then it is applied to a publicly available LiDAR data of a road cut rock slope at Rockbench repository. The extracted discontinuity orientations are compared with the method proposed by Riquelme et al. (2014). The results show that the presented method is reliable and of high accuracy, and can meet the engineering needs.

A gradient estimate for solutions to parabolic equations with discontinuous coefficients

Directory of Open Access Journals (Sweden)

Jishan Fan

2013-04-01

Full Text Available Li-Vogelius and Li-Nirenberg gave a gradient estimate for solutions of strongly elliptic equations and systems of divergence forms with piecewise smooth coefficients, respectively. The discontinuities of the coefficients are assumed to be given by manifolds of codimension 1, which we called them emph{manifolds of discontinuities}. Their gradient estimate is independent of the distances between manifolds of discontinuities. In this paper, we gave a parabolic version of their results. That is, we gave a gradient estimate for parabolic equations of divergence forms with piecewise smooth coefficients. The coefficients are assumed to be independent of time and their discontinuities are likewise the previous elliptic equations. As an application of this estimate, we also gave a pointwise gradient estimate for the fundamental solution of a parabolic operator with piecewise smooth coefficients. Both gradient estimates are independent of the distances between manifolds of discontinuities.

Structure of Lmaj006129AAA, a hypothetical protein from Leishmania major

International Nuclear Information System (INIS)

Arakaki, Tracy; Le Trong, Isolde; Phizicky, Eric; Quartley, Erin; DeTitta, George; Luft, Joseph; Lauricella, Angela; Anderson, Lori; Kalyuzhniy, Oleksandr; Worthey, Elizabeth; Myler, Peter J.; Kim, David; Baker, David; Hol, Wim G. J.; Merritt, Ethan A.

2006-01-01

The crystal structure of a conserved hypothetical protein from L. major, Pfam sequence family PF04543, structural genomics target ID Lmaj006129AAA, has been determined at a resolution of 1.6 Å. The gene product of structural genomics target Lmaj006129 from Leishmania major codes for a 164-residue protein of unknown function. When SeMet expression of the full-length gene product failed, several truncation variants were created with the aid of Ginzu, a domain-prediction method. 11 truncations were selected for expression, purification and crystallization based upon secondary-structure elements and disorder. The structure of one of these variants, Lmaj006129AAH, was solved by multiple-wavelength anomalous diffraction (MAD) using ELVES, an automatic protein crystal structure-determination system. This model was then successfully used as a molecular-replacement probe for the parent full-length target, Lmaj006129AAA. The final structure of Lmaj006129AAA was refined to an R value of 0.185 (R free = 0.229) at 1.60 Å resolution. Structure and sequence comparisons based on Lmaj006129AAA suggest that proteins belonging to Pfam sequence families PF04543 and PF01878 may share a common ligand-binding motif

Origin of discontinuities in coal-bearing strata at Roaring Creek (Basal Pennsylvanian of Indiana)

Energy Technology Data Exchange (ETDEWEB)

Nelson, W J; Eggert, D L; Dimichele, W A; Stecyk, A C

1985-05-01

Basal Pennsylvanian coal-bearing strata exposed along Roaring Creek, west-central Indiana, exhibit extreme lateral discontinuity. Coal seams abruptly change in thickness and elevation; they split, grade into shale, are cut out by channels and disrupted by soft-sediment deformational structures. Initial sediments were laid down by a network of southwest- flowing streams that traversed a deeply channelized upland surface of Mississippian carbonate rocks. Channels aggraded rapidly as uplands were worn down, so the region changed through time from uplands to upper deltaic plain. Local environments included channels, localized point bars, small natural levees and crevasse splays, overbank deposits, and swamps. Differential compaction and subsidence, slumping stream banks, and possibly collapsing sinkholes influenced sedimentation. As a consequence, coals are too discontinuous for economical mining, although they are locally thick and high in quality. 16 references.

A simple model of discontinuous firm’s growth

OpenAIRE

D'Elia, Enrico

2011-01-01

Typically, firms change their size through a row of discrete leaps over time. Sunk costs, regulatory, financial and organizational constraints, talent distribution and other factors may explain this fact. However, firms tend to grow or fall discontinuously even if those inertial factors were removed. For instance, a very essential model of discontinuous growth can be based on a couple of assumptions concerning only technology and entrepreneurs’ strategy, that is: (a) in the short run, the...

Reciprocity principle for scattered fields from discontinuities in waveguides.

Science.gov (United States)

Pau, Annamaria; Capecchi, Danilo; Vestroni, Fabrizio

2015-01-01

This study investigates the scattering of guided waves from a discontinuity exploiting the principle of reciprocity in elastodynamics, written in a form that applies to waveguides. The coefficients of reflection and transmission for an arbitrary mode can be derived as long as the principle of reciprocity is satisfied at the discontinuity. Two elastodynamic states are related by the reciprocity. One is the response of the waveguide in the presence of the discontinuity, with the scattered fields expressed as a superposition of wave modes. The other state is the response of the waveguide in the absence of the discontinuity oscillating according to an arbitrary mode. The semi-analytical finite element method is applied to derive the needed dispersion relation and wave mode shapes. An application to a solid cylinder with a symmetric double change of cross-section is presented. This model is assumed to be representative of a damaged rod. The coefficients of reflection and transmission of longitudinal waves are investigated for selected values of notch length and varying depth. Copyright © 2014 Elsevier B.V. All rights reserved.

Early Discontinuation of Montelukast Treatment; A Danish Nationwide Utilization Study

DEFF Research Database (Denmark)

Farah, Rahmo I; Damkier, Per; Christiansen, Anders

2018-01-01

Montelukast, a leukotriene receptor antagonist, was marketed in 1998 as an oral supplementary treatment to patients with mild to moderate asthma. The aim of this study was to describe the early discontinuation pattern among montelukast users in Denmark in the period of 1 March 1998 to 31 December....... Early discontinuation was defined as failing to fill a second prescription for montelukast within at least a year after the initial montelukast prescription. Among 135,271 included montelukast users, 47,480 (35%) discontinued the use of montelukast after a single redeemed prescription. The trend...

Risk of Vascular Thrombotic Events Following Discontinuation of Antithrombotics After Peptic Ulcer Bleeding.

Science.gov (United States)

Kim, Seung Young; Hyun, Jong Jin; Suh, Sang Jun; Jung, Sung Woo; Jung, Young Kul; Koo, Ja Seol; Yim, Hyung Joon; Park, Jong Jae; Chun, Hoon Jai; Lee, Sang Woo

2016-04-01

To evaluate whether the risk of cardiovascular events increases when antithrombotics are discontinued after ulcer bleeding. Peptic ulcer bleeding associated with antithrombotics has increased due to the increase in the proportion of elderly population. Little is known about the long-term effects of discontinuing antithrombotics after peptic ulcer bleeding. The aim of this study was to evaluate whether the risk of cardiovascular events increases when antithrombotics are discontinued after ulcer bleeding. We reviewed the medical records of patients with ulcer bleeding who were taking antiplatelet agents or anticoagulants at the time of ulcer bleeding. Cox-regression model was used to adjust for potential confounders, and analyzed association between discontinuation of antithrombotic drugs after ulcer bleeding and thrombotic events such as ischemic heart disease or stroke. Of the 544 patients with ulcer bleeding, 72 patients who were taking antithrombotics and followed up for >2 months were analyzed. Forty patients discontinued antithrombotics after ulcer bleeding (discontinuation group) and 32 patients continued antithrombotics with or without transient interruption (continuation group). Thrombotic events developed more often in discontinuation group than in the continuation group [7/32 (21.9%) vs. 1/40 (2.5%), P=0.019]. Hazard ratio for thrombotic event when antithrombotics were continuously discontinued was 10.9 (95% confidence interval, 1.3-89.7). There were no significant differences in recurrent bleeding events between the 2 groups. Discontinuation of antithrombotics after peptic ulcer bleeding increases the risk of cardiovascular events. Therefore, caution should be taken when discontinuing antithrombotics after ulcer bleeding.

Aberration changes of the corneal anterior surface following discontinued use of rigid gas permeable contact lenses

Directory of Open Access Journals (Sweden)

Shi-Qi Dong

2013-04-01

aberration of the anterior surface of the cornea. Changes to 2nd- and 3rd-order aberrations (including Z3, Z4, Z5, Z6, Z7, and Z8 were more significant. Following discontinued use of RGP contact lenses, the majority of lower order aberrations returned to original levels in a short period of time. During this process, a transient higher order aberration appeared, but all changes disappeared within 14 days after discontinued use of RGP contact lenses.

A study on the influence of track discontinuities on the degradation of the geometric quality supported by GPR

Science.gov (United States)

Paixao, Andre; Fontul, Simona; Salcedas, Tânia; Marques, Margarida

2017-04-01

It is known that locations in the track denoting sudden structural changes induce dynamic amplifications in the train-track interaction, thus leading to higher impact loads from trains, which in turn promote a faster development of track defects and increase the degradation of components. Consequently, a reduction in the quality of service can be expected at such discontinuities in the track, inducing higher maintenance costs and decreasing the life-cycle of components. To finding actual evidences on how track discontinuities influence the degradation of the geometric quality, a 50-km long railway section is used as case study. The track geometry data obtained with a recording car is firstly characterized according to the European standard series EN 13848. Then, the results of successive surveys are analysed, making use of various tools such as the standard deviation with moving windows of different sizes and calculating degradation rates. The GPR data was also analysed at the locations corresponding to track discontinuities aiming at better identifying situations where sudden changes occur regarding either the structural characteristics or the track behaviour over the years. The results indicate that the geometric quality degrades faster at locations denoting discontinuities in the track, such as changes in track components, approaches to bridges, tunnels, etc. This behaviour suggests that these sites should be monitored more carefully in the scope of asset management activities in order to maximize the life-cycle of the track and its components. This work is a contribution to COST (European COoperation on Science and Technology) Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar".

Discontinuous precipitation and ordering in Ni2V-Cu alloys

International Nuclear Information System (INIS)

Sukhanov, V.D; Boyarshinova, T.S.; Shashkov, O.D.

1986-01-01

Ni-V-Cu system alloys were used to investigate the effect of ordering on over-saturated solid solution decomposition. It was discovered that ordering in the process of grain boundary migration (discontinuous disordering), stimulated changing of continuous precipitation mechanism for discontinuous one

A gradient estimate for solutions to parabolic equations with discontinuous coefficients

OpenAIRE

Fan, Jishan; Kim, Kyoungsun; Nagayasu, Sei; Nakamura, Gen

2011-01-01

Li-Vogelius and Li-Nirenberg gave a gradient estimate for solutions of strongly elliptic equations and systems of divergence forms with piecewise smooth coefficients, respectively. The discontinuities of the coefficients are assumed to be given by manifolds of codimension 1, which we called them emph{manifolds of discontinuities}. Their gradient estimate is independent of the distances between manifolds of discontinuities. In this paper, we gave a parabolic version of their results. T...

Factors Influencing Contraceptive Choice and Discontinuation ...

African Journals Online (AJOL)

Erah

2010-03-30

women indicated that their HIV status dictated contraceptive decisions, particularly with ... Women reported method discontinuation because of side effects, having met desired parity, ...... Washington, D.C., 2009. ... Accessed March 30, 2010.

2D discontinuous piecewise linear map: Emergence of fashion cycles.

Science.gov (United States)

Gardini, L; Sushko, I; Matsuyama, K

2018-05-01

We consider a discrete-time version of the continuous-time fashion cycle model introduced in Matsuyama, 1992. Its dynamics are defined by a 2D discontinuous piecewise linear map depending on three parameters. In the parameter space of the map periodicity, regions associated with attracting cycles of different periods are organized in the period adding and period incrementing bifurcation structures. The boundaries of all the periodicity regions related to border collision bifurcations are obtained analytically in explicit form. We show the existence of several partially overlapping period incrementing structures, that is, a novelty for the considered class of maps. Moreover, we show that if the time-delay in the discrete time formulation of the model shrinks to zero, the number of period incrementing structures tends to infinity and the dynamics of the discrete time fashion cycle model converges to those of continuous-time fashion cycle model.

41 CFR 101-39.105 - Discontinuance or curtailment of service.

Science.gov (United States)

2010-07-01

..., AND MOTOR VEHICLES 39-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.1-Establishment, Modification, and Discontinuance of Interagency Fleet Management Systems § 101-39.105 Discontinuance or curtailment of service. (a... efficiencies are realized from the operation of any fleet management system, the Administrator, GSA, will...

How do horizontal, frictional discontinuities affect reverse fault-propagation folding?

Science.gov (United States)

Bonanno, Emanuele; Bonini, Lorenzo; Basili, Roberto; Toscani, Giovanni; Seno, Silvio

2017-09-01

The development of new reverse faults and related folds is strongly controlled by the mechanical characteristics of the host rocks. In this study we analyze the impact of a specific kind of anisotropy, i.e. thin mechanical and frictional discontinuities, in affecting the development of reverse faults and of the associated folds using physical scaled models. We perform analog modeling introducing one or two initially horizontal, thin discontinuities above an initially blind fault dipping at 30° in one case, and 45° in another, and then compare the results with those obtained from a fully isotropic model. The experimental results show that the occurrence of thin discontinuities affects both the development and the propagation of new faults and the shape of the associated folds. New faults 1) accelerate or decelerate their propagation depending on the location of the tips with respect to the discontinuities, 2) cross the discontinuities at a characteristic angle (∼90°), and 3) produce folds with different shapes, resulting not only from the dip of the new faults but also from their non-linear propagation history. Our results may have direct impact on future kinematic models, especially those aimed to reconstruct the tectonic history of faults that developed in layered rocks or in regions affected by pre-existing faults.

Seismic Discontinuities within the Crust and Mantle Beneath Indonesia as Inferred from P Receiver Functions

Science.gov (United States)

Woelbern, I.; Rumpker, G.

2015-12-01

Indonesia is situated at the southern margin of SE Asia, which comprises an assemblage of Gondwana-derived continental terranes, suture zones and volcanic arcs. The formation of SE Asia is believed to have started in Early Devonian. Its complex history involves the opening and closure of three distinct Tethys oceans, each accompanied by the rifting of continental fragments. We apply the receiver function technique to data of the temporary MERAMEX network operated in Central Java from May to October 2004 by the GeoForschungsZentrum Potsdam. The network consisted of 112 mobile stations with a spacing of about 10 km covering the full width of the island between the southern and northern coast lines. The tectonic history is reflected in a complex crustal structure of Central Java exhibiting strong topography of the Moho discontinuity related to different tectonic units. A discontinuity of negative impedance contrast is observed throughout the mid-crust interpreted as the top of a low-velocity layer which shows no depth correlation with the Moho interface. Converted phases generated at greater depth beneath Indonesia indicate the existence of multiple seismic discontinuities within the upper mantle and even below. The strongest signal originates from the base of the mantle transition zone, i.e. the 660 km discontinuity. The phase related to the 410 km discontinuity is less pronounced, but clearly identifiable as well. The derived thickness of the mantle-transition zone is in good agreement with the IASP91 velocity model. Additional phases are observed at roughly 33 s and 90 s relative to the P onset, corresponding to about 300 km and 920 km, respectively. A signal of reversed polarity indicates the top of a low velocity layer at about 370 km depth overlying the mantle transition zone.

Clopidogrel discontinuation within the first year after coronary drug-eluting stent implantation

DEFF Research Database (Denmark)

Thim, Troels; Johansen, Martin Berg; Chisholm, Gro Egholm

2014-01-01

BACKGROUND: The impact of adherence to the recommended duration of dual antiplatelet therapy after first generation drug-eluting stent implantation is difficult to assess in real-world settings and limited data are available. METHODS: We followed 4,154 patients treated with coronary drug-eluting ......BACKGROUND: The impact of adherence to the recommended duration of dual antiplatelet therapy after first generation drug-eluting stent implantation is difficult to assess in real-world settings and limited data are available. METHODS: We followed 4,154 patients treated with coronary drug......-eluting stents in Western Denmark for 1 year and obtained data on redeemed clopidogrel prescriptions and major adverse cardiovascular events (MACE, i.e., cardiac death, myocardial infarction, or stent thrombosis) from medical databases. RESULTS: Discontinuation of clopidogrel within the first 3 months after...... stent implantation was associated with a significantly increased rate of MACE at 1-year follow-up (hazard ratio (HR) 2.06; 95% confidence interval (CI): 1.08-3.93). Discontinuation 3-6 months (HR 1.29; 95% CI: 0.70-2.41) and 6-12 months (HR 1.29; 95% CI: 0.54-3.07) after stent implantation were...

Father's Labour Migration and Children's School Discontinuation in Rural Mozambique.

Science.gov (United States)

Yabiku, Scott T; Agadjanian, Victor

2017-08-01

We examine how the discontinuation of schooling among left-behind children is related to multiple dimensions of male labor migration: the accumulation of migration experience, the timing of these migration experiences in the child's life course, and the economic success of the migration. Our setting is rural southern Mozambique, an impoverished area with massive male labor out-migration. Results show that fathers' economically successful labor migration is more beneficial for children's schooling than unsuccessful migration or non-migration. There are large differences, however, by gender: compared to sons of non-migrants, sons of migrant fathers (regardless of migration success) have lower rates of school discontinuation, while daughters of migrant fathers have rates of school discontinuation no different than daughters of non-migrants. Furthermore, accumulated labor migration across the child's life course is beneficial for boys' schooling, but not girls'. Remittances sent in the past year reduce the rate of discontinuation for sons, but not daughters.

Effect of Discontinuation or Initiation of Methotrexate or Glucocorticoids on Tofacitinib Efficacy in Patients with Rheumatoid Arthritis: A Post Hoc Analysis.

Science.gov (United States)

Fleischmann, Roy; Wollenhaupt, Jürgen; Cohen, Stanley; Wang, Lisy; Fan, Haiyun; Bandi, Vara; Andrews, John; Takiya, Liza; Bananis, Eustratios; Weinblatt, Michael E

2018-06-01

Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We evaluated the effect of concomitant methotrexate (MTX) or glucocorticoid (GC) use on tofacitinib clinical efficacy. Data were pooled from two open-label, long-term extension studies of tofacitinib 5 or 10 mg twice daily in patients with RA. Response according to Clinical Disease Activity Index (CDAI) was assessed separately in patients who discontinued (no MTX/GC use within 30 days prior to year-3 visit; assessment at month 3/year 3) or initiated (on/before year 3; assessment at initiation and year 3) MTX/GC. By year 3, among patients receiving background MTX at baseline, 186/1608 (11.6%) discontinued MTX, and 319/1434 (22.2%) patients receiving GC at baseline discontinued GC. Overall, 70.4/69.1% of patients who discontinued/continued MTX and 72.7/65.9% who discontinued/continued GC achieved CDAI remission or low disease activity (LDA) at year 3. Month 3 remission/LDA rates were maintained at year 3 in the majority of patients, irrespective of MTX/GC discontinuation/continuation. By year 3, 6.2% of patients receiving tofacitinib without MTX at baseline had initiated concomitant MTX, and 25.1% receiving tofacitinib without GC initiated GC; 69.0% and 45.4% initiating MTX or GC, respectively, had a CDAI-defined incomplete response prior to initiation. RA signs/symptoms improved following MTX initiation; only modest improvement was observed with GC initiation. Patients achieving remission/LDA with tofacitinib may discontinue MTX or GC and maintain treatment response. Patients with an incomplete response may benefit from adding concomitant MTX. Pfizer Inc. Study A3921024 [NCT00413699] and Study A3921041 [NCT00661661].

Determination of Mantle Discontinuity Depths beneath the South Pacific Superswell As Inferred Using Data From Broadband OBS Array

Science.gov (United States)

Suetsugu, D.; Shiobara, H.; Sugioka, H.; Kanazawa, T.; Fukao, Y.

2005-12-01

We determined depths of the mantle discontinuities (the 410-km and 660-km discontinuities) beneath the South Pacific Superswell using waveform data from broadband ocean bottom seismograph (BBOBS) array to image presumed mantle plumes and their temperature anomalies. Seismic structure beneath this region had not previously been well explored in spite of its significance for mantle dynamics. The region is characterized by a topographic high of more than 680 m (Adam and Bonneville, 2005), a concentration of hotspot chains (e.g., Society, Cook-Austral, Marquesas, and Pitcairn) whose volcanic rocks have isotopic characteristics suggesting deep mantle origin, and a broad low velocity anomaly in the lower mantle revealed by seismic tomography. These observations suggest the presence of a whole-mantle scale upwelling beneath the region, which is called a 'superplume' (McNutt, 1998). However, the seismic structure has been only poorly resolved so far and the maximum depth of anomalous material beneath the hotspots has not yet been determined, mainly due to the sparseness of seismic stations in the region. To improve the seismic coverage, we deployed an array of 10 BBOBS over the French Polynesia area from 2003 to 2005. The BBOBS has been developed by Earthquake Research Institute of University of Tokyo and are equipped with the broadband CMG-3T/EBB sensor. The observation was conducted as a Japan-France cooperative project (Suetsugu et al., 2005, submitted to EOS). We computed receiver functions from the BBOBS data to detect Ps waves from the mantle discontinuities. The Velocity Spectrum Stacking method (Gurrola et al., 1994) were employed to enhance the Ps waves for determination of the discontinuity depths, in which receiver functions were stacked in a depth-velocity space. The Ps-waves from the mantle discontinuities were successfully detected at the most of the BBOBS stations, from which the discontinuity depths were determined with the Iasp91 velocity model. The 410-km

Discontinuance of ADHD Treatment in Adolescents

Directory of Open Access Journals (Sweden)

J Gordon Millichap

2009-04-01

Full Text Available Prevalence of ADHD drug discontinuance in adolescents and young adults was studied in the UK by using the General Practice Database for patients aged 15-21 years from 1999 to 2006.

Risk factors for the discontinuation of roflumilast in patients with chronic obstructive pulmonary disease

Directory of Open Access Journals (Sweden)

Kim KH

2017-12-01

Full Text Available Kyung Hoon Kim,1 Hye Seon Kang,2 Ju Sang Kim,3 Hyoung Kyu Yoon,4 Sung Kyoung Kim,5 Chin Kook Rhee1 1Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, 2Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Bucheon St Mary’s Hospital, College of Medicine, The Catholic University of Korea, Bucheon, 3Division of Pulmonary Medicine, Department of Internal Medicine, Incheon St Mary’s Hospital, College of Medicine, The Catholic University of Korea, Incheon, 4Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, 5Division of Pulmonary Medicine, Department of Internal Medicine, St Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea Introduction: Roflumilast is a phosphodiesterase-4 inhibitor, which can decrease exacerbation in patients with chronic obstructive pulmonary disease (COPD. However, adverse effects are a major barrier to medication use, and little is known regarding the risk factors for discontinuation of roflumilast in COPD patients.Method: A search of the clinical databases identified all patients who were prescribed roflumilast between December 2012 and April 2015 in the four hospitals of The Catholic University of Korea, Korea. The study subjects were limited to patients who had taken 500 µg of roflumilast. We studied the factors associated with drug discontinuation and drug adverse events by univariate and multivariate analyses.Results: Among 154 eligible patients, 54 (35.1% discontinued their roflumilast prescription. Most patients were elderly, male, current or former smokers, and had moderate-to-severe airflow limitation. Low–body mass index (BMI patients were more likely to undergo drug

21 CFR 1301.52 - Termination of registration; transfer of registration; distribution upon discontinuance of business.

Science.gov (United States)

2010-04-01

... discontinues business or professional practice. Any registrant who ceases legal existence or discontinues... registration; distribution upon discontinuance of business. 1301.52 Section 1301.52 Food and Drugs DRUG... of registration; transfer of registration; distribution upon discontinuance of business. (a) Except...

The Effect of Levothyroxine Discontinuation Timing on Postoperative Hypothyroidism after Hemithyroidectomy for Papillary Thyroid Microcarcinoma

Directory of Open Access Journals (Sweden)

Tae Kwun Ha

2016-01-01

Full Text Available Objective. No previous studies regarding the appropriate timing of thyroid hormone discontinuation after hemithyroidectomy have been published. This study aimed to identify the appropriate timing for levothyroxine discontinuation after hemithyroidectomy among patients with papillary thyroid microcarcinoma (PTMC. Methods. This study retrospectively evaluated 304 patients who underwent ≥1 attempt to discontinue levothyroxine after hemithyroidectomy for treating PTMC between January 2008 and December 2013. Fifty-three patients were excluded because of preoperative hypothyroidism or hyperthyroidism, a history of thyroid hormone or antithyroid therapy, no available serological data, or a postoperative follow-up of <24 months. We evaluated the associations of successful levothyroxine discontinuation with patient age, sex, preoperative serological data, underlying thyroid gland histopathology, anteroposterior diameter of the residual thyroid gland, number of discontinuation attempts, and initial discontinuation timing. Results. Among the 251 included patients, 125 patients (49.8% achieved successful levothyroxine discontinuation during the follow-up period after hemithyroidectomy. There was a significant difference in the outcomes for patients who underwent an initial discontinuation attempt at ≤3 months and ≥4 months after hemithyroidectomy (p < 0.001. There were significant differences in the discontinuation outcomes according to underlying thyroid histopathology (p = 0.001, preoperative thyroid-stimulating hormone levels (p < 0.001, and number of discontinuation attempts (p < 0.001. Conclusions. Among patients with PTMC, the initial levothyroxine discontinuation attempt is recommended at ≥4 months after hemithyroidectomy.

Quantum field theory near surfaces of discontinuity

International Nuclear Information System (INIS)

Onishi, H.T.

1981-01-01

This work deals with the problem of a quantized scalar field propagating near a surface of discontinuity. The proper time formalism is employed to express the Green's function and stress tensor as proper time integrals of a transformation function. The transformation function is calculated by a WKB approximation which exhibits the essential singularities generated by the high frequency behavior of waves propagating near the surface. Two singularities are present, the usual direct singularity and an additional reflected singularity generated by the high frequency behavior of waves reflected by the discontinuity. The stress tensor is calculated by dimensional continuation. The results are employed to analyze energy generated by the surface

Strong discontinuity with cam clay under large deformations

DEFF Research Database (Denmark)

Katic, Natasa; Hededal, Ole

2008-01-01

The work shows simultaneous implementation of Strong discontinuity approach (SDA) by means of Enhanced Assumed Strain (EAS) and Critical State Soil Mechanics CSSM) in large strain regime. The numerical model is based on an additive decomposition of the displacement gradient into a conforming and ...... and an enhanced part. The localized deformations are approximated by means of a discontinuous displacement field. The applied algorithm leads to a predictor/corrector procedure which is formally identical to the returnmapping algorithm of classical (local and continuous) Cam clay model....

Stacking by electroinjection with discontinuous buffers in capillary zone electrophoresis.

Science.gov (United States)

Shihabi, Zak K

2002-08-01

The work presented here demonstrates that electroinjection can be performed using discontinuous buffers, which can result in better stacking than that obtained by hydrodynamic injection. The sample can be concentrated at the tip of the capillary leaving practically the whole capillary for sample separation. This results in several advantages, such as better sample concentration, higher plate number and shorter time of stacking. However, sample introduction by electromigration is suited for samples free or low in salt content. Samples, which are high in salt content, are better introduced by the hydrodynamic injection for stacking by the discontinuous buffers. Different simple methods to introduce the discontinuity in the buffer for electroinjection are discussed.

Discontinuities Characteristics of the Upper Jurassic Arab-D Reservoir Equivalent Tight Carbonates Outcrops, Central Saudi Arabia

Science.gov (United States)

Abdlmutalib, Ammar; Abdullatif, Osman

2017-04-01

Jurassic carbonates represent an important part of the Mesozoic petroleum system in the Arabian Peninsula in terms of source rocks, reservoirs, and seals. Jurassic Outcrop equivalents are well exposed in central Saudi Arabia and which allow examining and measuring different scales of geological heterogeneities that are difficult to collect from the subsurface due to limitations of data and techniques. Identifying carbonates Discontinuities characteristics at outcrops might help to understand and predict their properties and behavior in the subsurface. The main objective of this study is to identify the lithofacies and the discontinuities properties of the upper Jurassic carbonates of the Arab D member and the Jubaila Formation (Arab-D reservoir) based on their outcrop equivalent strata in central Saudi Arabia. The sedimentologic analysis revealed several lithofacies types that vary in their thickness, abundances, cyclicity and vertical and lateral stacking patterns. The carbonates lithofacies included mudstone, wackestone, packstone, and grainstone. These lithofacies indicate deposition within tidal flat, skeletal banks and shallow to deep lagoonal paleoenvironmental settings. Field investigations of the outcrops revealed two types of discontinuities within Arab D Member and Upper Jubaila. These are depositional discontinuities and tectonic fractures and which all vary in their orientation, intensity, spacing, aperture and displacements. It seems that both regional and local controls have affected the fracture development within these carbonate rocks. On the regional scale, the fractures seem to be structurally controlled by the Central Arabian Graben System, which affected central Saudi Arabia. While, locally, at the outcrop scale, stratigraphic, depositional and diagenetic controls appear to have influenced the fracture development and intensity. The fracture sets and orientations identified on outcrops show similarity to those fracture sets revealed in the upper

Seismological evidence of the Hales discontinuity in northeast India

Science.gov (United States)

Anand, Aakash; Bora, Dipok K.; Borah, Kajaljyoti; Madhab Borgohain, Jayanta

2018-04-01

The crust and upper mantle shear wave velocity structure beneath the northeast India is estimated by joint inversion of Rayleigh wave group velocity and receiver function, calculated from teleseismic earthquakes data recorded at nine broadband seismic stations. The Assam valley and the Shillong-Mikir plateau are the two important tectonic blocks in the northeast India, which are surrounded by the Himalayan collision zone in the north, Indo-Burma subduction zone in the east and by the Bengal basin in the south. The joint inversion followed by forward modeling reveal crustal thicknesses of 30-34 km beneath the Shillong plateau, 36 km beneath the Mikir hills and 38-40 km beneath the Assam valley with an average shear wave velocity (Vs) of 3.4-3.5 km/s. The estimated low upper mantle shear wave velocity (Vsn) 4.2-4.3 km/s may be due to the rock composition or grain size or increased temperature and partial melt (<1%) in the upper mantle, or an effect of all. Also, we report for the first time, the existence of the Hales discontinuity at depths 56-74 km with Vs ∼4.4-4.6 km/s. Variable depth of the Hales discontinuity may be explained by the geotherm and/or addition of Cr3+ and Fe2+ in the spinel-garnet system.

Maximum volume cuboids for arbitrarily shaped in-situ rock blocks as determined by discontinuity analysis—A genetic algorithm approach

Science.gov (United States)

Ülker, Erkan; Turanboy, Alparslan

2009-07-01

The block stone industry is one of the main commercial use of rock. The economic potential of any block quarry depends on the recovery rate, which is defined as the total volume of useful rough blocks extractable from a fixed rock volume in relation to the total volume of moved material. The natural fracture system, the rock type(s) and the extraction method used directly influence the recovery rate. The major aims of this study are to establish a theoretical framework for optimising the extraction process in marble quarries for a given fracture system, and for predicting the recovery rate of the excavated blocks. We have developed a new approach by taking into consideration only the fracture structure for maximum block recovery in block quarries. The complete model uses a linear approach based on basic geometric features of discontinuities for 3D models, a tree structure (TS) for individual investigation and finally a genetic algorithm (GA) for the obtained cuboid volume(s). We tested our new model in a selected marble quarry in the town of İscehisar (AFYONKARAHİSAR—TURKEY).

A note on iterated function systems with discontinuous probabilities

International Nuclear Information System (INIS)

Jaroszewska, Joanna

2013-01-01

Highlights: ► Certain iterated function system with discontinuous probabilities is discussed. ► Existence of an invariant measure via the Schauder–Tychonov theorem is established. ► Asymptotic stability of the system under examination is proved. -- Abstract: We consider an example of an iterated function system with discontinuous probabilities. We prove that it posses an invariant probability measure. We also prove that it is asymptotically stable provided probabilities are positive

Discontinuities in Early Development of the Understanding of Physical Causality

Science.gov (United States)

Aschersleben, Gisa; Henning, Anne; Daum, Moritz M.

2013-01-01

Research on early physical reasoning has shown surprising discontinuities in developmental trajectories. Infants possess some skills that seem to disappear and then re-emerge in childhood. It has been suggested that prediction skills required in search tasks might cause these discontinuities (Keen, 2003). We tested 3.5- to 5-year-olds'…

Structural MRI correlates for vulnerability and resilience to major depressive disorder.

LENUS (Irish Health Repository)

Amico, Francesco

2011-01-01

In major depressive disorder (MDD), it is unclear to what extent structural brain changes are associated with depressive episodes or represent part of the mechanism by which the risk for illness is mediated. The aim of this study was to investigate whether structural abnormalities are related to risk for the development of MDD.

Reasons given by mothers for discontinuing breastfeeding in Iran

Directory of Open Access Journals (Sweden)

Olang Beheshteh

2012-05-01

Full Text Available Abstract Background We have previously shown that in Iran, only 28% of infants were exclusively breastfed at six months, despite a high prevalence of breastfeeding at two years of age. The primary aim of this study was to investigate the reasons women discontinued exclusive breastfeeding. Method This retrospective study was based on questionnaires and interviews with 63,071 mothers of infants up to 24 months of age, divided into two populations: infants younger than six months and six months or older. The data were collected in 2005–2006 from all 30 provinces of Iran. Results Only 5.3% of infants less than six months of age stopped breastfeeding (mean age of 3.2 months; more commonly in urban than rural areas. The most frequently cited reasons mothers gave for discontinuing exclusive breastfeeding were physicians’ recommendation (54% and insufficient breast milk (self-perceived or true, 28%. Breastfeeding was common after six months of age: only 11% of infants discontinued breastfeeding, at a mean of 13.8 months. The most common reason for discontinuation at this age was insufficient breast milk (self-perceived or true, 45%. Maternal illness or medication (10%, infant illness (6%, and return to work (3% were uncommon causes. Use of a pacifier was correlated with breastfeeding discontinuation. Maternal age and education was not associated with duration of breastfeeding. Multivariate analysis showed that using a pacifier and formula or other bottle feeding increased the risk of early cessation of breastfeeding. Conclusions Physicians and other health professionals have an important role to play in encouraging and supporting mothers to maintain breastfeeding.

Multi-slicing strategy for the three-dimensional discontinuity layout optimization (3D DLO).

Science.gov (United States)

Zhang, Yiming

2017-03-01

Discontinuity layout optimization (DLO) is a recently presented topology optimization method for determining the critical layout of discontinuities and the associated upper bound limit load for plane two-dimensional and three-dimensional (3D) problems. The modelling process (pre-processing) for DLO includes defining the discontinuities inside a specified domain and building the target function and the global constraint matrix for the optimization solver, which has great influence on the the efficiency of the computation processes and the reliability of the final results. This paper focuses on efficient and reliable pre-processing of the discontinuities within the 3D DLO and presents a multi-slicing strategy, which naturally avoids the overlapping and crossing of different discontinuities. Furthermore, the formulation of the 3D discontinuity considering a shape of an arbitrary convex polygon is introduced, permitting the efficient assembly of the global constraint matrix. The proposed method eliminates unnecessary discontinuities in 3D DLO, making it possible to apply 3D DLO for solving large-scale engineering problems such as those involving landslides. Numerical examples including a footing test, a 3D landslide and a punch indentation are considered, illustrating the effectiveness of the presented method. © 2016 The Authors. International Journal for Numerical and Analytical Methods in Geomechanics published by John Wiley & Sons Ltd.

Reversible brain inactivation induces discontinuous gas exchange in cockroaches.

Science.gov (United States)

Matthews, Philip G D; White, Craig R

2013-06-01

Many insects at rest breathe discontinuously, alternating between brief bouts of gas exchange and extended periods of breath-holding. The association between discontinuous gas exchange cycles (DGCs) and inactivity has long been recognised, leading to speculation that DGCs lie at one end of a continuum of gas exchange patterns, from continuous to discontinuous, linked to metabolic rate (MR). However, the neural hypothesis posits that it is the downregulation of brain activity and a change in the neural control of gas exchange, rather than low MR per se, which is responsible for the emergence of DGCs during inactivity. To test this, Nauphoeta cinerea cockroaches had their brains inactivated by applying a Peltier-chilled cold probe to the head. Once brain temperature fell to 8°C, cockroaches switched from a continuous to a discontinuous breathing pattern. Re-warming the brain abolished the DGC and re-established a continuous breathing pattern. Chilling the brain did not significantly reduce the cockroaches' MR and there was no association between the gas exchange pattern displayed by the insect and its MR. This demonstrates that DGCs can arise due to a decrease in brain activity and a change in the underlying regulation of gas exchange, and are not necessarily a simple consequence of low respiratory demand.

The Evolution of the Cup-Cage Technique for Major Acetabular Defects: Full and Half Cup-Cage Reconstruction.

Science.gov (United States)

Sculco, Peter K; Ledford, Cameron K; Hanssen, Arlen D; Abdel, Matthew P; Lewallen, David G

2017-07-05

Complex acetabular reconstruction for major bone loss can require advanced methods such as the use of a cup-cage construct. The purpose of this study was to review outcomes after the initial development of the cup-cage technique and the subsequent evolution to the use of a half cup-cage construct. We performed a retrospective, single-center review of 57 patients treated with cup-cage reconstruction for major acetabular bone loss. All patients had major acetabular defects graded as Paprosky Type 2B through 3B, with 34 (60%) having an associated pelvic discontinuity. Thirty patients received a full cup-cage construct and 27, a half cup-cage construct. The mean follow-up was 5 years. Both the full and half cup-cage cohorts demonstrated significantly improved Harris hip score (HHS) values, from 36 to 72 at a minimum of 2 years of follow-up (p cup-cage constructs and 6 (22%) of the half cup-cage constructs. One patient with a full cup-cage construct underwent re-revision of the acetabular component for progressive migration and aseptic loosening. Short-term survivorship free from re-revision for any cause or reoperation was 89% (83% and 96% for full and half cup-cage cohorts, respectively). Both full and half cup-cage constructs demonstrated successful clinical outcomes and survivorship in the treatment of major acetabular defects and pelvic discontinuity. Each method is utilized on the basis of individual intraoperative findings, including the extent and pattern of bone loss, the quality and location of host bone remaining after preparation, and the presence of pelvic discontinuity. Longer-term follow-up is required to understand the durability of these constructs in treating major acetabular defects and pelvic discontinuity. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Continued versus discontinued oxytocin stimulation, protocol of an rct

DEFF Research Database (Denmark)

Boie, Sidsel; Glavind, Julie; Uldbjerg, Niels

Dutch Centres: AMC, Tergooi Hospital, and AMPHIA Hospital (inclusion expected late 2016) Intervention When the active phase of labour is established (defined as 6 cm dilated orificium), the women will be randomised to either: Continued Syntocinon® or Discontinued Syntocinon® (saline infusion) Primary......Problem Statement: Previous studies on induced labour suggest that, continued stimulation with Syntocinon® in the active phase of labour increases the risk of fetal distress and caesarean delivery whereas discontinued stimulation with Syntocinon® increases the risk of caesarean delivery due to lack...... of progression. No double-blind trial with a study population large enough to show differences in maternal and neonatal outcomes has ever been conducted. The purpose of the study is to investigate how the caesarean delivery rate is affected if Syntocinon® is discontinued at the onset of active phase of labour...

Discontinuous phase transition in an open-ended Naming Game

International Nuclear Information System (INIS)

Crokidakis, Nuno; Brigatti, Edgardo

2015-01-01

In this work we study on a 2D square lattice a recent version of the Naming Game, an agent-based model used for describing the emergence of linguistic structures. The system is open-ended and agents can invent new words throughout the evolution of the game, picking them up from a pool characterised by a Gaussian distribution with standard deviation σ. The model displays a nonequilibrium phase transition at a critical point σ c  ≈ 25.6, which separates an absorbing consensus state from an active fragmented state where agents continuously exchange different words. The finite-size scaling analysis of our simulations strongly suggests that the phase transition is discontinuous. (paper)

Successful careers and cognitive style: a follow-up study of childhood family discontinuity.

Science.gov (United States)

Gordon, V Z

1991-12-01

It was predicted that those participants who experienced discontinuity (death, divorce, and separations) from their parent(s) in childhood and who had successful careers in adulthood would manifest more innovative than adaptive cognitive styles on the Kirton Adaption-Innovation Inventory. The original research showed 61% of the sample members (n = 41) experienced family discontinuity. Ninety percent (n = 37) of the previous participants responded and showed 59% family discontinuity. Fifty-four percent in the follow-up study chose an alternative career path (counterstriving), the same percentage as in the original sample. When both family discontinuity and counterstriving were present, statistically significant innovation scores occurred. Family discontinuity in childhood and a successful career in adulthood are likely to be associated with high striving-motivation and an innovative (paradigm-breaking) problem-solving style.

Efficacy and Safety Outcomes in Patients With Advanced Melanoma Who Discontinued Treatment With Nivolumab and Ipilimumab Because of Adverse Events: A Pooled Analysis of Randomized Phase II and III Trials.

Science.gov (United States)

Schadendorf, Dirk; Wolchok, Jedd D; Hodi, F Stephen; Chiarion-Sileni, Vanna; Gonzalez, Rene; Rutkowski, Piotr; Grob, Jean-Jacques; Cowey, C Lance; Lao, Christopher D; Chesney, Jason; Robert, Caroline; Grossmann, Kenneth; McDermott, David; Walker, Dana; Bhore, Rafia; Larkin, James; Postow, Michael A

2017-12-01

Purpose Approximately 40% of patients with advanced melanoma who received nivolumab combined with ipilimumab in clinical trials discontinued treatment because of adverse events (AEs). We conducted a retrospective analysis to assess the efficacy and safety of nivolumab plus ipilimumab in patients who discontinued treatment because of AEs. Methods Data were pooled from phase II and III trials of patients who received nivolumab 1 mg/kg plus ipilimumab 3 mg/kg, every 3 weeks for four doses, followed by nivolumab monotherapy 3 mg/kg every 2 weeks (N = 409). Efficacy was assessed in all randomly assigned patients who discontinued because of AEs during the induction phase (n = 96) and in those who did not discontinue because of AEs (n = 233). Safety was assessed in treated patients who discontinued because of AEs (n = 176) at any time and in those who did not discontinue because of AEs (n = 231). Results At a minimum follow-up of 18 months, median progression-free survival was 8.4 months for patients who discontinued treatment because of AEs during the induction phase and 10.8 months for patients who did not discontinue because of AEs ( P = .97). Median overall survival had not been reached in either group ( P = .23). The objective response rate was 58.3% for patients who discontinued because of AEs during the induction phase and 50.2% for patients who did not discontinue. The vast majority of grade 3 or 4 AEs occurred during the induction phase, with most resolving after appropriate management. Conclusion Efficacy outcomes seemed similar between patients who discontinued nivolumab plus ipilimumab treatment because of AEs during the induction phase and those who did not discontinue because of AEs. Therefore, even after discontinuation, many patients may continue to derive benefit from combination therapy.

Why do couples discontinue unlimited free IVF treatments?

Science.gov (United States)

Lande, Yechezkel; Seidman, Daniel S; Maman, Ettie; Baum, Micha; Hourvitz, Ariel

2015-03-01

Worldwide, IVF is often discontinued before a live birth is achieved due to high costs. Even when partial financial coverage is provided, often medical providers advise treatment discontinuation. In Israel, unlimited IVF is offered free of charge for a couples' first two children. Our objective was to assess the reasons couples discontinue IVF treatments before achieving two children in a completely unlimited cost-free environment. This cohort study included all primary infertile women, reason they ceased treatments. Of the 134 couples included, only 46 ceased IVF treatments without achieving two children, after performing an average of 6.2 IVF cycles to achieve their first birth. The reasons given were: lost hope of success (13), psychological burden (18), divorce (6), medical staff recommendation (5), bureaucratic difficulties (3) and general medical condition (1). The main reasons for "drop out" in our cost-free environment were as follows: psychological burden and lost hope of success. Due to high availability of treatments, medical staff recommendation was a less significant factor in our study.

Reflection and transmission of ion acoustic waves from a plasma discontinuity

International Nuclear Information System (INIS)

Gary, S.P.; Alexeff, I.; Bloomberg, H.W.

1975-01-01

Transmission and reflection coefficients are calculated for an ion acoustic wave incident from the upstream direction upon a plasma discontinuity of width much less than the wavelength. In the limit of an infinitely strong discontinuity there is complete in phase reflection. (U.S.)

Discontinuous precipitation and ordering in Ni/sub 2/V-Cu alloys

Energy Technology Data Exchange (ETDEWEB)

Sukhanov, V D; Boyarshinova, T S; Shashkov, O D

1986-12-01

Ni-V-Cu system alloys were used to investigate the effect of ordering on over-saturated solid solution decomposition. It was discovered that ordering in the process of grain boundary migration (discontinuous disordering), stimulated changing of continuous precipitation mechanism for discontinuous one.

Photoemission investigation of the ZnSe/CdTe heterojunction band discontinuity

International Nuclear Information System (INIS)

Nelson, A.J.

1995-01-01

Synchrotron radiation soft x-ray photoemission spectroscopy and reflection high-energy electron diffraction were used to investigate the structural and electronic properties at the ZnSe/CdTe(100) heterojunction interface. ZnSe overlayers were sequentially grown in steps on p-type CdTe(100) single crystals at 200 degree C. In situ photoemission measurements were acquired after each growth in order to observe changes in the valence band electronic structure as well as changes in the Cd 4d, Zn 3d, and Te 4d core lines. The results were used to correlate the interfacial chemistry with the electronic structure and to directly determine the ZnSe/CdTe heterojunction valence band discontinuity and the consequent heterojunction band diagram. Results of these measurements reveal that the valence band offset is ΔE v =0.20 eV. copyright 1995 American Institute of Physics

Regression Discontinuity in Prospective Evaluations: The Case of the FFVP Evaluation

Science.gov (United States)

Klerman, Jacob Alex; Olsho, Lauren E. W.; Bartlett, Susan

2015-01-01

While regression discontinuity has usually been applied retrospectively to secondary data, it is even more attractive when applied prospectively. In a prospective design, data collection can be focused on cases near the discontinuity, thereby improving internal validity and substantially increasing precision. Furthermore, such prospective…

Modeling shallow water flows using the discontinuous Galerkin method

CERN Document Server

Khan, Abdul A

2014-01-01

Replacing the Traditional Physical Model Approach Computational models offer promise in improving the modeling of shallow water flows. As new techniques are considered, the process continues to change and evolve. Modeling Shallow Water Flows Using the Discontinuous Galerkin Method examines a technique that focuses on hyperbolic conservation laws and includes one-dimensional and two-dimensional shallow water flows and pollutant transports. Combines the Advantages of Finite Volume and Finite Element Methods This book explores the discontinuous Galerkin (DG) method, also known as the discontinuous finite element method, in depth. It introduces the DG method and its application to shallow water flows, as well as background information for implementing and applying this method for natural rivers. It considers dam-break problems, shock wave problems, and flows in different regimes (subcritical, supercritical, and transcritical). Readily Adaptable to the Real World While the DG method has been widely used in the fie...

Modeling the radiation transfer of discontinuous canopies: results for gap probability and single-scattering contribution

Science.gov (United States)

Zhao, Feng; Zou, Kai; Shang, Hong; Ji, Zheng; Zhao, Huijie; Huang, Wenjiang; Li, Cunjun

2010-10-01

In this paper we present an analytical model for the computation of radiation transfer of discontinuous vegetation canopies. Some initial results of gap probability and bidirectional gap probability of discontinuous vegetation canopies, which are important parameters determining the radiative environment of the canopies, are given and compared with a 3- D computer simulation model. In the model, negative exponential attenuation of light within individual plant canopies is assumed. Then the computation of gap probability is resolved by determining the entry points and exiting points of the ray with the individual plants via their equations in space. For the bidirectional gap probability, which determines the single-scattering contribution of the canopy, a gap statistical analysis based model was adopted to correct the dependence of gap probabilities for both solar and viewing directions. The model incorporates the structural characteristics, such as plant sizes, leaf size, row spacing, foliage density, planting density, leaf inclination distribution. Available experimental data are inadequate for a complete validation of the model. So it was evaluated with a three dimensional computer simulation model for 3D vegetative scenes, which shows good agreement between these two models' results. This model should be useful to the quantification of light interception and the modeling of bidirectional reflectance distributions of discontinuous canopies.

Discontinuous jamming transitions in soft materials: coexistence of flowing and jammed states

International Nuclear Information System (INIS)

Dennin, Michael

2008-01-01

Many systems in nature exhibit transitions between fluid-like states and solid-like states, or 'jamming transitions'. There is a strong theoretical foundation for understanding equilibrium phase transitions that involve solidification, or jamming. Other jamming transitions, such as the glass transition, are less well understood. The jamming phase diagram has been proposed to unify the description of equilibrium phase transitions, the glass transitions, and other nonequilibrium jamming transitions. As with equilibrium phase transitions, which can either be first order (discontinuous in a relevant order parameter) or second order (continuous), one would expect that generalized jamming transitions can be continuous or discontinuous. In studies of flow in complex fluids, there is a wide range of evidence for discontinuous transitions, mostly in the context of shear localization, or shear banding. In this paper, I review the experimental evidence for discontinuous transitions. I focus on systems in which there is a discontinuity in the rate of strain between two, coexisting states: one in which the material is flowing and the other in which it is solid-like. (topical review)

[Analysis of aberration changes of the corneal anterior surface following discontinued use of rigid gas permeable contact lenses].

Science.gov (United States)

Yu, Qing; Wu, Jiang-xiu; Zhang, He-ning; Ye, Sheng; Dong, Shi-qi; Zhang, Chen-hao

2011-04-01

use RGP contact lenses greatly reduced total aberration of the anterior surface of the cornea. Changes to 2(nd)- and 3(rd)-order aberrations (including Z3, Z4, Z5, Z6, Z7, and Z8) were more significant. Following discontinued use of RGP contact lenses, the majority of lower order aberrations returned to original levels in a short period of time. During this process, a transient higher order aberration appeared, but all changes disappeared within 2 weeks after discontinued use of RGP contact lenses.

Speedup of minimum discontinuity phase unwrapping algorithm with a reference phase distribution

Science.gov (United States)

Liu, Yihang; Han, Yu; Li, Fengjiao; Zhang, Qican

2018-06-01

In three-dimensional (3D) shape measurement based on phase analysis, the phase analysis process usually produces a wrapped phase map ranging from - π to π with some 2 π discontinuities, and thus a phase unwrapping algorithm is necessary to recover the continuous and nature phase map from which 3D height distribution can be restored. Usually, the minimum discontinuity phase unwrapping algorithm can be used to solve many different kinds of phase unwrapping problems, but its main drawback is that it requires a large amount of computations and has low efficiency in searching for the improving loop within the phase's discontinuity area. To overcome this drawback, an improvement to speedup of the minimum discontinuity phase unwrapping algorithm by using the phase distribution on reference plane is proposed. In this improved algorithm, before the minimum discontinuity phase unwrapping algorithm is carried out to unwrap phase, an integer number K was calculated from the ratio of the wrapped phase to the nature phase on a reference plane. And then the jump counts of the unwrapped phase can be reduced by adding 2K π, so the efficiency of the minimum discontinuity phase unwrapping algorithm is significantly improved. Both simulated and experimental data results verify the feasibility of the proposed improved algorithm, and both of them clearly show that the algorithm works very well and has high efficiency.

Discontinuous Galerkin finite element methods for radiative transfer in spherical symmetry

Science.gov (United States)

Kitzmann, D.; Bolte, J.; Patzer, A. B. C.

2016-11-01

The discontinuous Galerkin finite element method (DG-FEM) is successfully applied to treat a broad variety of transport problems numerically. In this work, we use the full capacity of the DG-FEM to solve the radiative transfer equation in spherical symmetry. We present a discontinuous Galerkin method to directly solve the spherically symmetric radiative transfer equation as a two-dimensional problem. The transport equation in spherical atmospheres is more complicated than in the plane-parallel case owing to the appearance of an additional derivative with respect to the polar angle. The DG-FEM formalism allows for the exact integration of arbitrarily complex scattering phase functions, independent of the angular mesh resolution. We show that the discontinuous Galerkin method is able to describe accurately the radiative transfer in extended atmospheres and to capture discontinuities or complex scattering behaviour which might be present in the solution of certain radiative transfer tasks and can, therefore, cause severe numerical problems for other radiative transfer solution methods.

A Floating Node Method for the Modelling of Discontinuities Within a Finite Element

Science.gov (United States)

Pinho, Silvestre T.; Chen, B. Y.; DeCarvalho, Nelson V.; Baiz, P. M.; Tay, T. E.

2013-01-01

This paper focuses on the accurate numerical representation of complex networks of evolving discontinuities in solids, with particular emphasis on cracks. The limitation of the standard finite element method (FEM) in approximating discontinuous solutions has motivated the development of re-meshing, smeared crack models, the eXtended Finite Element Method (XFEM) and the Phantom Node Method (PNM). We propose a new method which has some similarities to the PNM, but crucially: (i) does not introduce an error on the crack geometry when mapping to natural coordinates; (ii) does not require numerical integration over only part of a domain; (iii) can incorporate weak discontinuities and cohesive cracks more readily; (iv) is ideally suited for the representation of multiple and complex networks of (weak, strong and cohesive) discontinuities; (v) leads to the same solution as a finite element mesh where the discontinuity is represented explicitly; and (vi) is conceptually simpler than the PNM.

Validation of a patient interview for assessing reasons for antipsychotic discontinuation and continuation

Directory of Open Access Journals (Sweden)

Matza LS

2012-07-01

Full Text Available Louis S Matza,1 Glenn A Phillips,2 Dennis A Revicki,1 Haya Ascher-Svanum,3 Karen G Malley,4 Andrew C Palsgrove,1 Douglas E Faries,3 Virginia Stauffer,3 Bruce J Kinon,3 A George Awad,5 Richard SE Keefe,6 Dieter Naber71Outcomes Research, United BioSource Corporation, Bethesda, MD, 2Formerly with Eli Lilly and Company, Indianapolis, IN, 3Eli Lilly and Company, Indianapolis, IN, 4Malley Research Programming, Inc, Rockville, MD, USA; 5Department of Psychiatry and Behavioral Sciences; University of Toronto, Toronto, Canada; 6Duke University Medical Center, Durham NC, USA; 7Universitaetsklinikum Hamburg-Eppendorf, Hamburg, GermanyIntroduction: The Reasons for Antipsychotic Discontinuation Interview (RAD-I was developed to assess patients’ perceptions of reasons for discontinuing or continuing an antipsychotic. The current study examined reliability and validity of domain scores representing three factors contributing to these treatment decisions: treatment benefits, adverse events, and distal reasons other than direct effects of the medication.Methods: Data were collected from patients with schizophrenia or schizoaffective disorder and their treating clinicians. For approximately 25% of patients, a second rater completed the RAD-I for assessment of inter-rater reliability.Results: All patients (n = 121; 81 discontinuation, 40 continuation reported at least one reason for discontinuation or continuation (mean = 2.8 reasons for discontinuation; 3.4 for continuation. Inter-rater reliability was supported (kappas = 0.63–1.0. Validity of the discontinuation domain scores was supported by associations with symptom measures (the Positive and Negative Syndrome Scale for Schizophrenia, the Clinical Global Impression – Schizophrenia Scale; r = 0.30 to 0.51; all P < 0.01, patients’ primary reasons for discontinuation, and adverse events. However, the continuation domain scores were not significantly associated with these other indicators

Time-dependent behavior of rough discontinuities under shearing conditions

Science.gov (United States)

Wang, Zhen; Shen, Mingrong; Ding, Wenqi; Jang, Boan; Zhang, Qingzhao

2018-02-01

The mechanical properties of rocks are generally controlled by their discontinuities. In this study, the time-dependent behavior of rough artificial joints under shearing conditions was investigated. Based on Barton’s standard profile lines, samples with artificial joint surfaces were prepared and used to conduct the shear and creep tests. The test results showed that the shear strength of discontinuity was linearly related to roughness, and subsequently an empirical equation was established. The long-term strength of discontinuity can be identified using the inflection point of the isocreep-rate curve, and it was linearly related to roughness. Furthermore, the ratio of long-term and instantaneous strength decreased with the increase of roughness. The shear-stiffness coefficient increased with the increase of shear rate, and the influence of shear rate on the shear stiffness coefficient decreased with the decrease of roughness. Further study of the mechanism revealed that these results could be attributed to the different time-dependent behavior of intact and joint rocks.

Mechanics of interfaces and evolving discontinuities

NARCIS (Netherlands)

De Borst, René; Remmers, Joris J C; Verhoosel, Clemens V.; Needleman, Alan; Zingoni, A.

2013-01-01

The two main approaches to the modelling of discontinuities are reviewed concisely, followed by a discussion of cohesive models for fracture. Emphasis is put on a novel approach to incorporate triaxiality into cohesive-zone models, and on the representation of cohesive crack models by phase-field

77 FR 26185 - POSTNET Barcode Discontinuation

Science.gov (United States)

2012-05-03

... discontinue POSTNET barcodes for automation letter and flat price eligibility. There were six comments... on each piece, to facilitate processing by presort companies. We added language to specifically allow..., with or without prepayment of postage, for return to the address on the reply piece. If postage is...

Schrödinger propagation of initial discontinuities leads to divergence of moments

Science.gov (United States)

Marchewka, A.; Schuss, Z.

2009-09-01

We show that the large phase expansion of the Schrödinger propagation of an initially discontinuous wave function leads to the divergence of average energy, momentum, and displacement, rendering them unphysical states. If initially discontinuous wave functions are considered to be approximations to continuous ones, the determinant of the spreading rate of these averages is the maximal gradient of the initial wave function. Therefore a dilemma arises between the inclusion of discontinuous wave functions in quantum mechanics and the requirement of finite moments.

An Analysis of Contraceptive Discontinuation among Female, Reversible Method Users in Urban Honduras

Science.gov (United States)

Barden-O’Fallon, Janine; Speizer, Ilene S.; Cálix, Javier; Rodriguez, Francisco

2013-01-01

A panel study examining the effects of individual characteristics, side effects experienced, and service quality on contraceptive discontinuation was undertaken in four urban areas of Honduras. Data were collected from October 2006 to December 2007. The baseline population included 800 women aged 15–44 who were new or continuing users of the injectable, IUD, or oral contraceptive pill. A total of 671 women (84%) were re-interviewed after one year. Life tables and Cox proportional hazards models are used to present discontinuation rates and factors associated with contraceptive discontinuation. Among new users, discontinuation of the baseline method at 12 months was high (45%); especially for users of the injectable (50%). In the hazards model, service quality had little effect on discontinuation, while individual characteristics and the experience of specific side effects showed significant effects. The results suggest that programs should emphasize continuous contraceptive coverage rather than continuous use of a particular method. PMID:21500697

First-line antiretroviral drug discontinuations in children.

Directory of Open Access Journals (Sweden)

Melony Fortuin-de Smidt

Full Text Available There are a limited number of paediatric antiretroviral drug options. Characterising the long term safety and durability of different antiretrovirals in children is important to optimise management of HIV infected children and to determine the estimated need for alternative drugs in paediatric regimens. We describe first-line antiretroviral therapy (ART durability and reasons for discontinuations in children at two South African ART programmes, where lopinavir/ritonavir has been recommended for children <3 years old since 2004, and abacavir replaced stavudine as the preferred nucleoside reverse transcriptase inhibitor in 2010.We included children (<16 years at ART initiation who initiated ≥3 antiretrovirals between 2004-2014 with ≥1 follow-up visit on ART. We estimated the incidence of first antiretroviral discontinuation using Kaplan-Meier analysis. We determined the reasons for antiretroviral discontinuations using competing risks analysis. We used Cox regression to identify factors associated with treatment-limiting toxicity.We included 3579 children with median follow-up duration of 41 months (IQR 14-72. At ART initiation, median age was 44 months (IQR 13-89 and median CD4 percent was 15% (IQR 9-21%. At three and five years on ART, 72% and 26% of children respectively remained on their initial regimen. By five years on ART, the most common reasons for discontinuations were toxicity (32%, treatment failure (18%, treatment simplification (5%, drug interactions (3%, and other or unspecified reasons (18%. The incidences of treatment limiting toxicity were 50.6 (95% CI 46.2-55.4, 1.6 (0.5-4.8, 2.0 (1.2-3.3, and 1.3 (0.6-2.8 per 1000 patient years for stavudine, abacavir, efavirenz and lopinavir/ritonavir respectively.While stavudine was associated with a high risk of treatment-limiting toxicity, abacavir, lopinavir/ritonavir and efavirenz were well-tolerated. This supports the World Health Organization recommendation to replace stavudine with

Variation formulae for the solutions of delay differential equations with discontinuous initial conditions

International Nuclear Information System (INIS)

Kharatishvili, G L; Tadumadze, T A

2005-01-01

Variation formulae are proved for solutions of non-linear differential equations with variable delays and discontinuous initial conditions. The discontinuity of the initial condition means that at the initial moment of time the values of the initial function and the trajectory, generally speaking, do not coincide. The formulae obtained contain a new summand connected with the discontinuity of the initial condition and the variation of the initial moment.

Anterior segment optical coherence tomography changes with introduction and discontinuation of tamsulosin.

Science.gov (United States)

Al-Kharashi, Abdullah; Azimzadeh, Amir A; Leung, Jerry; Radomski, Sidney; Radomski, Lenny; Lam, Wai-Ching

2016-01-01

The aim of this study was to quantify changes and reversibility in pupil dilation and iris dilator muscle region thickness associated with introduction and subsequent discontinuation of tamsulosin in patients naïve to this drug with the aid of an anterior OCT system. The study was carried out on 7 patients (14 eyes) naïve to tamsulosin and with benign prostatic hypertrophy (BHP). Measurements taken by Vistante OCT were done pre- and post-dilation of the following: pupil size, iris dilator muscle region (DMR) thickness, sphincter muscle region (SMR) thickness, and anterior chamber depth. These measurement were taken at Day 0 (tamsulosin naive), Day 30 (after one month of tamsulosin, the treatment period) and day 60 (after one month of no tamsulosin, the discontinuation period). Post-dilation pupil diameter significantly increased during the discontinuation period ( P  = 0.047). Iris DMR thickness measurements post-dilation significantly decreased during treatment ( P  = 0.00044), discontinuation (0.00011), and combined periods ( P  = 0.000050). Anterior chamber depth measurements in post-dilation were significantly decreased during treatment ( P  = 0.0016), discontinuation ( P  = 0.017), and combined periods ( P  = 0.00022). Tamsulosin discontinuation effectively increases dilated pupil size, a measure that has been inversely linked to IFIS incidence pre-operatively. Decreased DMR thickness in this short term likely illustrates changes aside from atrophy, such as vascular changes. Decreased anterior chamber depths suggest aqueous humor production is decreased as well.

Stress-assisted discontinuous precipitation during creep of Ti3Al-Nb alloys

International Nuclear Information System (INIS)

Rowe, R.G.; Hall, E.L.

1991-01-01

Stress-assisted discontinuous precipitation was observed during creep of Ti-25Al-12.5Nb at. pct and associated with microstructures in which large primary creep strains were observed earlier. It was found that a large shift between the equilibrium beta(0) (B2) phase composition at the heat treatment temperature and disordered beta (bcc) phase at the creep temperature provided a driving force for discontinuous precipitation of disordered beta phase. Applied stress accelerated the growth of discontinuous beta phase at grain boundaries perpendicular to the principal stress axis, but did not produce a significant shift in composition. The difference between beta and ordered beta phase boundaries in the Ti-Al-Nb system at 650 C and 1040 C suggests that discontinuous precipitation or related dissolution should occur in all Ti3Al-Nb alloys. 11 refs

Extreme interplanetary rotational discontinuities at 1 AU

Science.gov (United States)

Lepping, R. P.; Wu, C.-C.

2005-11-01

This study is concerned with the identification and description of a special subset of four Wind interplanetary rotational discontinuities (from an earlier study of 134 directional discontinuities by Lepping et al. (2003)) with some "extreme" characteristics, in the sense that every case has (1) an almost planar current sheet surface, (2) a very large discontinuity angle (ω), (3) at least moderately strong normal field components (>0.8 nT), and (4) the overall set has a very broad range of transition layer thicknesses, with one being as thick as 50 RE and another at the other extreme being 1.6 RE, most being much thicker than are usually studied. Each example has a well-determined surface normal (n) according to minimum variance analysis and corroborated via time delay checking of the discontinuity with observations at IMP 8 by employing the local surface planarity. From the variance analyses, most of these cases had unusually large ratios of intermediate-to-minimum eigenvalues (λI/λmin), being on average 32 for three cases (with a fourth being much larger), indicating compact current sheet transition zones, another (the fifth) extreme property. For many years there has been a controversy as to the relative distribution of rotational (RDs) to tangential discontinuities (TDs) in the solar wind at 1 AU (and elsewhere, such as between the Sun and Earth), even to the point where some authors have suggested that RDs with large ∣Bn∣s are probably not generated or, if generated, are unstable and therefore very rare. Some of this disagreement apparently has been due to the different selection criteria used, e.g., some allowed eigenvalue ratios (λI/λmin) to be almost an order of magnitude lower than 32 in estimating n, usually introducing unacceptable error in n and therefore also in ∣Bn∣. However, we suggest that RDs may not be so rare at 1 AU, but good quality cases (where ∣Bn∣ confidently exceeds the error in ∣Bn∣) appear to be uncommon, and further

Discontinuous drainage systems formed by highland precipitation and ground-water outflow in the Navua Valles and southwest Hadriacus Mons regions, Mars

Science.gov (United States)

Hargitai, H. I.; Gulick, V. C.; Glines, N. H.

2017-09-01

The Navua Valles are systems of paleodrainages located north of Dao Vallis, which empty into Hellas Planitia, the largest impact basin on Mars. In this study, we mapped and characterized the Navua Valles Region's individual drainage systems, including drainages along the southwestern flank of Hadriacus Mons, and one valley network from the same source as Navua Valles but flowing in the opposite direction. The major drainage systems share morphological characteristics common to both outflow channels and valley networks. The slopes in this region are dissected by two major Navua drainage systems (here Navua A* and B*) and several shorter, sub-parallel valleys formed on the highest gradient (approximately 20 m/km [1.15°]) slopes, at the lowest part of Hellas Basin's rim. The two major drainage systems originate in the highlands, and empty into the basin. Our mapping suggests that water in Navua Valles reached the basin floor in a complicated descent and included several episodes of surface ponding, surface runoff, infiltration, subsurface flow and subsequent outflow. The most prominent channel system, Navua A, forms a repetitive sequence of deep incision into bedrock, followed by a transition into broad channels in erodible materials, and then into unconfined deposits. This successive erosion-transport-deposition sequence continues to repeat along the valley's entire length forming a discontinuous pattern that is consistent with classical fluvial process models. The channels cut into volcanic plains likely emplaced from the formation of Tyrrhenus and Hadriacus Montes. The dendritic source valleys of Navua A originate from the rim of a highland crater while the rest of this subsystem consists of a single, discontinuous channel which is consistent with a single water source zone that likely supplied water for all channels downslope. These drainages may have formed as discontinuous channels, revealing the potential existence of subsurface drainage pathways located

Insufficient recruitment and premature discontinuation of clinical trials in Switzerland: qualitative study with trialists and other stakeholders.

Science.gov (United States)

Briel, Matthias; Elger, Bernice; von Elm, Erik; Satalkar, Priya

2017-11-29

Premature discontinuation occurs in about 25% of randomised clinical trials in Switzerland; it mainly affects investigator-initiated trials and is mostly due to problems with recruitment of patients. The aim of this study was to qualitatively investigate reasons for trial discontinuation due to poor patient recruitment and suggestions to address those reasons in the Swiss context. We conducted semi-structured interviews with trialists whose trials were discontinued because of recruitment problems, other experienced trialists, and stakeholders in clinical research in Switzerland. Interviews were audio-recorded, transcribed verbatim, and anonymised. We analysed the transcripts using deductive coding and built up themes that were continuously discussed within the research team. Of 65 invited Swiss trialists and stakeholders, 39 (60%) agreed to be interviewed and contributed to this analysis. We identified four main themes of reasons for poor recruitment: (1) Switzerland has a decentralised healthcare system with many small hospitals and few patients per hospital, many research regulations, no standardisation of medical records across hospitals, and a heterogeneous ethics assessment of study protocols. There is little collaboration of different stakeholders in clinical research and a lack of prioritisation of projects. (2) Limited human and financial resources, especially in the academic setting, compromise research questions and size of clinical trials. When funding is used up this typically triggers discontinuation of already delayed clinical trials. (3) Investigators face underdeveloped research networks and a limited collaborative attitude among clinical researchers. They typically embark on clinical studies with a great deal of optimism but insufficient preparation. (4) Swiss patients have universal health coverage and many treatment options. Negative media coverage of clinical research and a lack of accessible information for patients about ongoing clinical

Predictors of discontinuation of antipsychotic medication and subsequent outcomes in the European First Episode Schizophrenia Trial (EUFEST).

Science.gov (United States)

Landolt, Karin; Rössler, Wulf; Ajdacic-Gross, Vladeta; Derks, Eske M; Libiger, Jan; Kahn, René S; Fleischhacker, W Wolfgang

2016-04-01

This study had two aims: to describe patients suffering from first-episode schizophrenia who had stopped taking any antipsychotic medication, and to gain information on the predictors of successful discontinuation. We investigated data from the European First Episode Schizophrenia Trial (EUFEST). From the 325 patients included, 15.7% discontinued all antipsychotic medication. In a first analysis, clinical and sociodemographical predictors of discontinuing any antipsychotic medication were identified, using Cox regression. In the second analysis, logistic regression was used to determine variables associated with those patients who had stopped taking antipsychotic medication and had a favourable outcome, i.e., successful discontinuation. A good outcome was defined as a) having had no relapse within the whole observation period (80.6%), and b) having had no relapse and symptomatic remission at 12-month-follow-up (37.2%). Cox regression revealed that a higher proportion of patients from Western European countries and Israel stopped antipsychotic medication than from Central and Eastern European countries, that relapse was associated with discontinuation, and that discontinuers had lower compliance and higher quality of life. Predictors of successful discontinuation differed with the outcome definition used. Using definition b), successful discontinuers had a better baseline prognosis and better baseline social integration. Using definition a), successful discontinuers more often were from Western European countries. Region and clinical factors were associated with discontinuation. Prognosis and social integration played an important role in predicting successful discontinuation. As this study had several limitations, for example the observational design regarding discontinuation, further studies are needed to identify predictors of successful discontinuation. Copyright © 2016 Elsevier B.V. All rights reserved.

Active postoperative acromegaly: sustained remission after discontinuation of somatostatin analogues

Directory of Open Access Journals (Sweden)

Cristina Alvarez-Escola

2016-11-01

Full Text Available In patients with active acromegaly after pituitary surgery, somatostatin analogues are effective in controlling the disease and can even be curative in some cases. After treatment discontinuation, the likelihood of disease recurrence is high. However, a small subset of patients remains symptom-free after discontinuation, with normalized growth hormone (GH and insulin-like growth factor (IGF1 levels. The characteristics of patients most likely to achieve sustained remission after treatment discontinuation are not well understood, although limited evidence suggests that sustained remission is more likely in patients with lower GH and IGF1 levels before treatment withdrawal, in those who respond well to low-dose treatment, in those without evidence of adenoma on an MRI scan and/or in patients who receive long-term treatment. In this report, we describe the case of a 56-year-old female patient treated with lanreotide Autogel for 11 years. Treatment was successfully discontinued, and the patient is currently disease-free on all relevant parameters (clinical, biochemical and tumour status. The successful outcome in this case adds to the small body of literature suggesting that some well-selected patients who receive long-term treatment with somatostatin analogues may achieve sustained remission.

Problems with Discontinuous Diffusion/Dispersion Coefficients

Directory of Open Access Journals (Sweden)

Stefano Ferraris

2012-01-01

accurate on smooth solutions and based on a special numerical treatment of the diffusion/dispersion coefficients that makes its application possible also when such coefficients are discontinuous. Numerical experiments confirm the convergence of the numerical approximation and show a good behavior on a set of benchmark problems in two space dimensions.

Reasons for Discontinuing Hashish Use in a Group of Central European Athletes.

Science.gov (United States)

Duncan, David F.

1988-01-01

Examined self-reported reasons for discontinuing marijuana use among 61 former marijuana using students at central European sports training facility. Most common reasons given for discontinuing marijuana use were dislike of effects, athletic training regimen, health reasons, and mental/emotional problems. (Author/NB)

A numerical study on the structural behavior of underground rock caverns for radioactive waste disposal

International Nuclear Information System (INIS)

Kim, Sun Hoon; Choi, Kyu Sup; Lee, Kyung Jin; Kim, Dae Hong

1991-01-01

In order to design safe and economical underground disposal structures for radioactive wastes, understanding the behavior of discontinuous rock masses is essential. This study includes discussions about the computational model for discontinuous rock masses and the structural analysis method for underground storage structures. Then, based on an engineering judgement a suitable selection and slight modifications on computational models and analysis methods have been made in order to analyze and understand the structural behavior of the rock cavern with discontinuities

Interior penalty discontinuous Galerkin method for coupled elasto-acoustic media

OpenAIRE

Dudouit , Yohann; Giraud , Luc; Millot , Florence; Pernet , Sébastien

2016-01-01

We introduce a high order interior penalty discontinuous Galerkin scheme for the nu- merical solution of wave propagation in coupled elasto-acoustic media. A displacement formulation is used, which allows for the solution of the acoustic and elastic wave equations within the same framework. Weakly imposing the correct transmission condition is achieved by the derivation of adapted numerical fluxes. This generalization does not weaken the discontinuous Galerkin method, thus hp-non-conforming m...

Reactive oxygen species production and discontinuous gas exchange in insects

OpenAIRE

Boardman, Leigh; Terblanche, John S.; Hetz, Stefan K.; Marais, Elrike; Chown, Steven L.

2011-01-01

While biochemical mechanisms are typically used by animals to reduce oxidative damage, insects are suspected to employ a higher organizational level, discontinuous gas exchange mechanism to do so. Using a combination of real-time, flow-through respirometry and live-cell fluorescence microscopy, we show that spiracular control associated with the discontinuous gas exchange cycle (DGC) in Samia cynthia pupae is related to reactive oxygen species (ROS). Hyperoxia fails to increase mean ROS produ...

A novel scheme for Liouville's equation with a discontinuous Hamiltonian and applications to geometrical optics

NARCIS (Netherlands)

Lith, van B.S.; Thije Boonkkamp, ten J.H.M.; IJzerman, W.L.; Tukker, T.W.

2015-01-01

We compute numerical solutions of Liouville's equation with a discontinuous Hamiltonian. We assume that the underlying Hamiltonian system has a well-defined behaviour even when the Hamiltonian is discontinuous. In the case of geometrical optics such a discontinuity yields the familiar Snell's law or

A novel scheme for Liouville's equation with a discontinuous Hamiltonian and applications to geometrical optics

NARCIS (Netherlands)

van Lith, B.S.; ten Thije Boonkkamp, J.H.M.; IJzerman, W.L.; Tukker, T.W.

A novel scheme is developed that computes numerical solutions of Liouville’s equation with a discontinuous Hamiltonian. It is assumed that the underlying Hamiltonian system has well-defined behaviour even when the Hamiltonian is discontinuous. In the case of geometrical optics such a discontinuity

First Trimester Influenza Vaccination and Risks for Major Structural Birth Defects in Offspring.

Science.gov (United States)

Kharbanda, Elyse Olshen; Vazquez-Benitez, Gabriela; Romitti, Paul A; Naleway, Allison L; Cheetham, T Craig; Lipkind, Heather S; Klein, Nicola P; Lee, Grace; Jackson, Michael L; Hambidge, Simon J; McCarthy, Natalie; DeStefano, Frank; Nordin, James D

2017-08-01

To examine risks for major structural birth defects in infants after first trimester inactivated influenza vaccine (IIV) exposures. In this observational study, we used electronic health data from 7 Vaccine Safety Datalink sites to examine risks for selected major structural defects in infants after maternal IIV exposure. Vaccine exposures for women with continuous insurance enrollment through pregnancy who delivered singleton live births between 2004 and 2013 were identified from standardized files. Infants with continuous insurance enrollment were followed to 1 year of age. We excluded mother-infant pairs with other exposures that potentially increased their background risk for birth defects. Selected cardiac, orofacial or respiratory, neurologic, ophthalmologic or otologic, gastrointestinal, genitourinary and muscular or limb defects were identified from diagnostic codes in infant medical records using validated algorithms. Propensity score adjusted generalized estimating equations were used to estimate prevalence ratios (PRs). We identified 52 856 infants with maternal first trimester IIV exposure and 373 088 infants whose mothers were unexposed to IIV during first trimester. Prevalence (per 100 live births) for selected major structural birth defects was 1.6 among first trimester IIV exposed versus 1.5 among unexposed mothers. The adjusted PR was 1.02 (95% CI 0.94-1.10). Organ system-specific PRs were similar to the overall PR. First trimester maternal IIV exposure was not associated with an increased risk for selected major structural birth defects in this large cohort of singleton live births. Copyright © 2017 Elsevier Inc. All rights reserved.

76 FR 41413 - Post Office Organization and Administration: Establishment, Classification, and Discontinuance

Science.gov (United States)

2011-07-14

... Handbook PO-101, Post Office Discontinuance Guide, have provided only that community meetings are one... contract where sound business judgment and effective oversight would require otherwise. CPO operators would... that the emergency suspension form in Handbook PO-101, Post Office Discontinuance Guide, currently does...

A second order discontinuous Galerkin method for advection on unstructured triangular meshes

NARCIS (Netherlands)

Geijselaers, Hubertus J.M.; Huetink, Han

2003-01-01

In this paper the advection of element data which are linearly distributed inside the elements is addressed. Across element boundaries the data are assumed discontinuous. The equations are discretized by the Discontinuous Galerkin method. For stability and accuracy at large step sizes (large values

Controlling chaos in discontinuous dynamical systems

International Nuclear Information System (INIS)

Danca, Marius-F.

2004-01-01

In this paper we consider the possibility to implement the technique of changes in the system variables to control the chaos introduced by Gueemez and Matias for continuous dynamical systems to a class of discontinuous dynamical systems. The approach is realized via differential inclusions following the Filippov theory. Three practical examples are considered

Discontinuation of Preventive Drugs in General Practice

DEFF Research Database (Denmark)

Andersen, John Sahl; Lindberg, Laura Maria Glahder; Nixon, Michael Simon

Introduction: In Denmark about 600,000 persons are treated for hypertension and more than 300,000 people are receiving cholesterol lowering drugs. The prevalence of hypertension in people aged 80 years is 70%. For antidepressants the defined daily doses/1000 aged >80 years/day exceed 200. By far...... the most preventive drugs are prescribed in general practice. Special considerations exist in relation to medication of elderly patients. The prevalence of polypharmacy and the subsequent increased risk of side effects and drug interactions is high. Drug-related problems represent the fifth leading cause...... of death in the United States. The public expenses to drug treatment are constantly increasing. The possibility to withdraw the medication must be taken into account but the decision to discontinue drugs is complex and poorly understood. Planned studies: 1. Patients’ views upon discontinuation...

La-doped BaTiO3 heterostructures: Compensating the polarization discontinuity

Directory of Open Access Journals (Sweden)

D. P. Kumah

2013-12-01

Full Text Available We demonstrate a route to manipulate the polarization and internal electric field of a complex oxide heterostructure using a layering sequence based on the LaAlO3-SrTiO3 interface. By combining sensitive atomic-level mapping of the structure using direct x-ray phase-retrieval methods with theoretical modeling of the electrostatic charge and polarization, we have devised a novel single-domain polar heterostructure. We find that ionic rearrangement results in strain and free energy minimization, and eliminates the polarization discontinuity leading to a two-fold increase of the spontaneous polarization towards the surface of an ultra-thin single-domain BaTiO3 film.

Supply risk under the condition of discontinuous demand in the field of nuclear power industry

International Nuclear Information System (INIS)

Wei Qiyan; Tian Zhilong

2006-01-01

Demands can be divided into two kinds: continuous and discontinuous demands. Based on the analysis of the results on common supply risk studies, discontinuous demand is studied concerning its definition, characteristics, and the more obvious and severe risks and consequences induced by its characteristics. Furthermore, the discontinuous characteristics and relevant precautions of demand of nuclear power industry are analyzed. Analysis and research on supply risks under the condition of discontinuous demand would be helpful to enterprises to take this issue serious and prevent the risks. (authors)

Clinical outcomes associated with per-operative discontinuation of aspirin in patients with coronary artery disease: A systematic review and meta-analysis.

Science.gov (United States)

Luni, Faraz Khan; Riaz, Haris; Khan, Abdur Rahman; Riaz, Talha; Husnain, Muhammad; Riaz, Irbaz Bin; Khan, Muhammad Shahzeb; Taleb, Mohammed; Kanjwal, Yusuf; Cooper, Christopher J; Khuder, Sadik A

2017-06-01

Postoperative state is characterized by increased thrombotic risk by virtue of platelet activation. Whether aspirin ameliorates this risk in patients with established coronary artery disease undergoing cardiac or noncardiac surgery is unknown. We conducted a systematic review and meta-analysis to compare the risk of major adverse cardiac events (MACE) and the risk of bleeding in patients with early (3-5 or more days before surgery) vs. late discontinuation(aspirin. Multiple databases were searched from inception of these databases until March 2015 to identify studies that reported discontinuation of aspirin in patients undergoing surgery. The outcomes measured were all cause mortality, nonfatal myocardial infarction and other relevant thrombotic events (MACE) which also may include, fatal and nonfatal MI, stent thrombosis and restenosis, stroke, perioperative cardiovascular complications (heart failure, MI, VTE, acute stroke) and perioperative bleeding during the perioperative period to up to 30 days after surgery. A total of 1,018 titles were screened, after which six observational studies met the inclusion criteria. Our analysis suggests that there is no difference in MACE with planned discontinuation of aspirin (OR = 1.17, 95% CI = 0.76-1.81; P = 0.05; I 2  = 55%). Early discontinuation of aspirin showed a decreased risk of peri-operative bleeding (OR 0.82, 95% CI = 0.67-0.99; P = 0.04; I 2  = 42%). Our analysis suggests that planned short-term discontinuation in the appropriate clinical setting appears to be safe in the correct clinical setting with no increased risk of thrombotic events and with a decreased risk of bleeding. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Application of discontinuity factors in C-PORCA 7 code

International Nuclear Information System (INIS)

Pos, I.; Parko, T.; Szabo, S. P.

2010-01-01

During last years there were up-rated the reactor power up to 1485 MW and new fuel types have been utilised at the Paks NPP. To fulfil the demand of the accuracy and correctness of on-line core monitoring and off-line core analysis the HELIOS/C-PORCA models have been modernised as well. The main step of this developing process was to change the mathematics of the 3D two group diffusion model on the basis of hybrid finite element method. The upgraded mathematics gave very good results comparing the C-PORCA calculations against mathematical benchmarks and measurements of different units and cycles of NPP Paks and Mochovce. As a final step of the modernisation process the application of flux discontinuity factors has been made. In the frame of VVER community the usage of this parameter in core analyses codes is very unusual in contrast with codes for the same purpose in western countries. In this paper both the reason of the introduction of discontinuity factors into HELIOS/C-PORCA models and its effect on the accuracy of calculation are also presented. We tried to emphasise which kind of codes and which kind of reactor-physical parameters can be influenced mainly by discontinuity factors. The method of the calculation of flux discontinuity factors in fuel and non-fuel regions of the core is also described. As the most important effect of the utilisation of this parameter was that almost all fittings in C-PORCA code based on in-core measurements have became needless. (Authors)

A longitudinal examination of alcohol pharmacotherapy adoption in substance use disorder treatment programs: patterns of sustainability and discontinuation.

Science.gov (United States)

Abraham, Amanda J; Knudsen, Hannah K; Roman, Paul M

2011-07-01

The objectives of this study were to (a) identify the patterns of disulfiram (Antabuse) and tablet naltrexone (Revia) adoption over a 48-month period in a nationally representative sample of privately funded programs that deliver substance use disorder treatment; (b) examine predictors of sustainability, later adoption, discontinuation, and nonadoption of disulfiram and tablet naltrexone; and (c) measure reasons for medication discontinuation. Two waves of data were collected via face-to-face structured interviews with 223 program administrators. These data demonstrated that adoption of medications for alcohol use disorders (AUDs) was a dynamic process. Although nonadoption was the most common pattern, approximately 20% of programs sustained use of the AUD medications and 30% experienced organizational change in adoption over the study period. Bivariate multinomial logistic regression models revealed that organizational characteristics were associated with sustainability including location in a hospital setting, program size, accreditation, revenues from private insurance, referrals from the criminal justice system, number of medical staff, and use of selective serotonin reuptake inhibitors at baseline. Two patterns of discontinuation were found: Programs either discontinued use of all substance use disorder medications or replaced disulfiram/tablet naltrexone with a newer AUD medication. These findings suggest that adoption of AUD medications may be positively affected by pressure from accreditation bodies, partnering with primary care physicians, medication-specific training for medical staff, greater availability of resources to cover the costs associated with prescribing AUD medications, and amending criminal justice contracts to include support for AUD medication use.

A transient, Hex-Z nodal code corrected by discontinuity factors

International Nuclear Information System (INIS)

Shatilla, Y.A.M.; Henry, A.F.

1993-01-01

This document constitutes Volume 1 of the Final Report of a three-year study supported by the special Research Grant Program for Nuclear Energy Research set up by the US Department of Energy. The original motivation for the work was to provide a fast and accurate computer program for the analysis of transients in heavy water or graphite-moderated reactors being considered as candidates for the New Production Reactor. Thus, part of the funding was by way of pass-through money from the Savannah River Laboratory. With this intent in mind, a three-dimensional (Hex-Z), general-energy-group transient, nodal code was created, programmed, and tested. In order to improve accuracy, correction terms, called open-quotes discontinuity factors,close quotes were incorporated into the nodal equations. Ideal values of these factors force the nodal equations to provide node-integrated reaction rates and leakage rates across nodal surfaces that match exactly those edited from a more exact reference calculation. Since the exact reference solution is needed to compute the ideal discontinuity factors, the fact that they result in exact nodal equations would be of little practical interest were it not that approximate discontinuity factors, found at a greatly reduced cost, often yield very accurate results. For example, for light-water reactors, discontinuity factors found from two-dimensional, fine-mesh, multigroup transport solutions for two-dimensional cuts of a fuel assembly provide very accurate predictions of three-dimensional, full-core power distributions. The present document (volume 1) deals primarily with the specification, programming and testing of the three-dimensional, Hex-Z computer program. The program solves both the static (eigenvalue) and transient, general-energy-group, nodal equations corrected by user-supplied discontinuity factors

Discontinuous precipitation in copper base alloys

Indian Academy of Sciences (India)

Discontinuous precipitation (DP) is associated with grain boundary migration in the wake of which alternate plates of the precipitate and the depleted matrix form. Some copper base alloys show DP while others do not. In this paper the misfit strain parameter, , has been calculated and predicted that if 100 > ± 0.1, DP is ...

Discontinuous Galerkin for the Radiative Transport Equation

KAUST Repository

Guermond, Jean-Luc

2013-10-11

This note presents some recent results regarding the approximation of the linear radiative transfer equation using discontinuous Galerkin methods. The locking effect occurring in the diffusion limit with the upwind numerical flux is investigated and a correction technique is proposed.

Regression Discontinuity Designs Based on Population Thresholds

DEFF Research Database (Denmark)

Eggers, Andrew C.; Freier, Ronny; Grembi, Veronica

In many countries, important features of municipal government (such as the electoral system, mayors' salaries, and the number of councillors) depend on whether the municipality is above or below arbitrary population thresholds. Several papers have used a regression discontinuity design (RDD...

Discontinuous Galerkin for the Radiative Transport Equation

KAUST Repository

Guermond, Jean-Luc; Kanschat, Guido; Ragusa, Jean C.

2013-01-01

This note presents some recent results regarding the approximation of the linear radiative transfer equation using discontinuous Galerkin methods. The locking effect occurring in the diffusion limit with the upwind numerical flux is investigated and a correction technique is proposed.

Hybridized Multiscale Discontinuous Galerkin Methods for Multiphysics

Science.gov (United States)

2015-09-14

local approximation spaces of the hybridizable discontinuous Galerkin methods with precomputed phases which are solutions of the eikonal equation in...geometrical optics. Second, we propose a systematic procedure for computing multiple solutions of the eikonal equation. Third, we utilize the eigenvalue

Early Discontinuation of Metformin in Individuals Treated with Inhibitors of Transporters of Metformin

DEFF Research Database (Denmark)

Stage, Tore Bjerregaard; Lee, Moa P; Hallas, Jesper

2016-01-01

The aim of this study was to examine the risk of early discontinuation of metformin as a proxy for intolerance, associated with use of drugs known to inhibit transporters involved in metformin distribution. We analysed all incident users of metformin in Denmark between 2000 and 2012 (n = 132......,221) and in a cohort of US patients (n = 296,903). Risk of early discontinuation of metformin was assessed using adjusted logistic regression for 28 drugs putatively inhibiting metformin transporters and four negative controls. Increased odds ratio of early discontinuation of metformin was only associated with codeine...... drugs were associated with a decreased risk. These findings indicate that codeine use may be associated with risk of early discontinuation of metformin and could be used as a basis for further investigation....

Discontinuation of continuous renal replacement therapy: A post hoc analysis of a prospective multicenter observational study

NARCIS (Netherlands)

Uchino, Shigehiko; Bellomo, Rinaldo; Morimatsu, Hiroshi; Morgera, Stanislao; Schetz, Miet; Tan, Ian; Bouman, Catherine; Macedo, Ettiene; Gibney, Noel; Tolwani, Ashita; Oudemans-van Straaten, Heleen; Ronco, Claudio; Kellum, John A.

2009-01-01

Objectives: To describe current practice for the discontinuation of continuous renal replacement therapy in a multinational setting and to identify variables associated with successful discontinuation. The approach to discontinue continuous renal replacement therapy may affect patient outcomes.

ELECTRON TEMPERATURES OF PLANETARY NEBULAE DETERMINED FROM THE He I DISCONTINUITIES

International Nuclear Information System (INIS)

Zhang, Y.; Nakashima, J.; Kwok, S.; Yuan, H.-B.; Liu, X.-W.; Hua, C.-T.

2009-01-01

We have used the He I discontinuities at 3421 A to determine the electron temperatures, designated T e (He I), for a sample of five Galactic planetary nebulae (PNe). We compared T e (He I) with the electron temperatures derived from the hydrogen Balmer jump at 3646 A, designated T e (H I), and found that T e (He I) are generally lower than T e (H I). There are two possible interpretations, (1) the presence of substantial He 2+ zone, or (2) the presence of hydrogen-deficient cold clumps within diffuse nebulae. A series of photoionization models were constructed to test the two scenarios. We found that the observed T e (He I)/T e (H I) discrepancies are beyond the predictions of chemically homogeneous models. Our modeling shows that the presence of a small amount of hydrogen-deficient inclusions seems to be able to reproduce the observed intensities of He I discontinuities. We stress the value of He I discontinuities in investigating nebular physical conditions. Albeit with some observational and technical limitations, He I discontinuities should be considered in future modeling work.

Einstein’s “true” discontinuity.With an application to Zeno

Directory of Open Access Journals (Sweden)

Constantin Antonopoulos

2009-11-01

Full Text Available The question whether quantum discontinuity can or cannot provide an answer to Zeno’s Paradoxes is reopened. It is observed that what is usually understood by the term “discontinuity”, namely, Einstein’s conception of the photon as described by himself and all others, is unsuitable to the task because, essentially,it reduces to the trivial ‘discontinuity’ of objects scattered in space. By contrast, quantization of energy levels, which are not in space but can only alternate in time, provide the right sort of discontinuity required. Discrete quantized orbits, corresponding to eigen-frequencies, are irreducible, and nothing is allowed to stand in-between them in satisfaction of the quantum postulate, furnishing the requisite, and so far missing, immediate nextness of a point to a certain other. In this way, Zeno’s Runner need not postpone his first step indefinitely, always waiting upon an infinity of preceding steps, before it can be taken. There is now a point that is next to a point and so a step on that point, which is the first step. It follows that, if one kind of discontinuity, Einstein’s, is incapable of offerring an answer to Zeno, while another kind can, the two are discrepant. One of them, the former, is not a kind of discontinuity properly so called at all, though evidently the consequence of one.

Impedance Discontinuity Reduction Between High-Speed Differential Connectors and PCB Interfaces

Science.gov (United States)

Navidi, Sal; Agdinaoay, Rodell; Walter, Keith

2013-01-01

High-speed serial communication (i.e., Gigabit Ethernet) requires differential transmission and controlled impedances. Impedance control is essential throughout cabling, connector, and circuit board construction. An impedance discontinuity arises at the interface of a high-speed quadrax and twinax connectors and the attached printed circuit board (PCB). This discontinuity usually is lower impedance since the relative dielectric constant of the board is higher (i.e., polyimide approx. = 4) than the connector (Teflon approx. = 2.25). The discontinuity can be observed in transmit or receive eye diagrams, and can reduce the effective link margin of serial data networks. High-speed serial data network transmission improvements can be made at the connector-to-board interfaces as well as improving differential via hole impedances. The impedance discontinuity was improved by 10 percent by drilling a 20-mil (approx. = 0.5-mm) hole in between the pin of a differential connector spaced 55 mils (approx. = 1.4 mm) apart as it is attached to the PCB. The effective dielectric constant of the board can be lowered by drilling holes into the board material between the differential lines in a quadrax or twinax connector attachment points. The differential impedance is inversely proportional to the square root of the relative dielectric constant. This increases the differential impedance and thus reduces the above described impedance discontinuity. The differential via hole impedance can also be increased in the same manner. This technique can be extended to multiple smaller drilled holes as well as tapered holes (i.e., big in the middle followed by smaller ones diagonally).

Discontinuities of Plastic Deformation in Metallic Glasses with Different Glass Forming Ability

Science.gov (United States)

Hurakova, Maria; Csach, Kornel; Miskuf, Jozef; Jurikova, Alena; Demcak, Stefan; Ocelik, Vaclav; Hosson, Jeff Th. M. De

The metallic ribbons Fe40Ni40B20, Cu47Ti35Zr11Ni6Si1 and Zr65Cu17.5Ni10Al7.5 with different microhardness and glass forming ability were studied at different loading rates from 0.05 to 100 mN/s. We describe in details the differences in elemental discontinuities on the loading curves for the studied alloys. It was found that the discontinuities began at a certain local deformation independently on the macroscopic mechanical properties of a ribbon. More developed discontinuities at higher deformations are created for the materials with lower microhardness and so lower strength.

Trial discontinuation: lessons for future trial design?

NARCIS (Netherlands)

V.J.A.A. Nuij (Veerle); C.J. de Haar (Colin); C.J. van der Woude (Janneke)

2012-01-01

textabstractBackground: The current therapeutic arsenal still does not fulfill the therapeutic needs of inflammatory bowel disease patients. Although new drugs are constantly being developed, many will never reach the market. In this review we will search for reasons for discontinuing promising

Determining the Locations and Discontinuities in the Derivatives of Functions

International Nuclear Information System (INIS)

Archibald, Richard K.; Gelb, Anne; Yoon, Jungho

2007-01-01

We introduce a method for detecting discontinuities in piecewise smooth functions and in their derivatives. The method is constructed from a local stencil of grid point values and is based on a polynomial annihilation technique. By varying the order of the method and the arrangement of the corresponding stencils, the jump discontinuities of a function and its derivatives can be identified with high order accuracy. The method is efficient and robust and can be applied to non-uniform distributions in one dimension

On cell entropy inequality for discontinuous Galerkin methods

Science.gov (United States)

Jiang, Guangshan; Shu, Chi-Wang

1993-01-01

We prove a cell entropy inequality for a class of high order discontinuous Galerkin finite element methods approximating conservation laws, which implies convergence for the one dimensional scalar convex case.

Pin cell discontinuity factors in the transient 3-D discrete ordinates code TORT-TD - 237

International Nuclear Information System (INIS)

Seubert, A.

2010-01-01

This paper describes the application of generalized equivalence theory to the time-dependent 3-D discrete ordinates neutron transport code TORT-TD. The introduction of pin cell discontinuity factors into the discrete ordinates transport equation is described by assuming a linear dependence of the homogenized neutron angular flux within a pin cell which may be discontinuous at the interfaces to adjacent cells. The homogenized flux discontinuity at cell interfaces is expressed by pin cell discontinuity factors which in turn are determined from fuel assembly lattice calculations using HELIOS. Application of TORT-TD to the all rods in state of the PWR MOX/UO 2 Core Transient Benchmark with pin cell homogenized nuclear cross sections demonstrate the potential of pin cell discontinuity factors to reduce pin cell homogenization errors. (authors)

Hollow cylindrical plasma filament waveguide with discontinuous finite thickness cladding

International Nuclear Information System (INIS)

Alshershby, Mostafa; Hao Zuoqiang; Lin Jingquan

2013-01-01

We have explored here a hollow cylindrical laser plasma multifilament waveguide with discontinuous finite thickness cladding, in which the separation between individual filaments is in the range of several millimeters and the waveguide cladding thickness is in the order of the microwave penetration depth. Such parameters give a closer representation of a realistic laser filament waveguide sustained by a long stable propagation of femtosecond (fs) laser pulses. We report how the waveguide losses depend on structural parameters like normalized plasma filament spacing, filament to filament distance or pitch, normal spatial frequency, and radius of the plasma filament. We found that for typical plasma parameters, the proposed waveguide can support guided modes of microwaves in extremely high frequency even with a cladding consisting of only one ring of plasma filaments. The loss of the microwave radiation is mainly caused by tunneling through the discontinuous finite cladding, i.e., confinement loss, and is weakly dependent on the plasma absorption. In addition, the analysis indicates that the propagation loss is fairly large compared with the loss of a plasma waveguide with a continuous infinite thickness cladding, while they are comparable when using a cladding contains more than one ring. Compared to free space propagation, this waveguide still presents a superior microwave transmission to some distance in the order of the filamentation length; thus, the laser plasma filaments waveguide may be a potential channel for transporting pulsed-modulated microwaves if ensuring a long and stable propagation of fs laser pulses.

Predictors of premature clopidogrel discontinuation within 30 days of successful coronary artery stenting

Directory of Open Access Journals (Sweden)

Çayan Cakir

2018-01-01

Full Text Available Objective: We aimed to determine the prevalence, predictors, and mortality rate of premature clopidogrel discontinuation within 30 days of successful coronary stenting. Methods: All consecutive patients who underwent successful coronary stent implantation at our hospital between December 2006 and December 2007 were prospectively included in this study. Patients were interviewed by telephone 30 days after stent implantation. Premature clopidogrel discontinuation was defined as follows: patients who did not continue clopidogrel after discharge were defined as “never used” and patients who received clopidogrel for <20 days or interrupted therapy for at least 5 successive days within the first 30 days were defined as “partially used.” Results: Follow-up data were available for 381 patients and 58 (15.2% patients reported premature clopidogrel discontinuation. No mortality and only 1 (0.3% stent thrombosis occurred in adherent patients, whereas there were 2 (3.4% mortalities and 6 (10.3% stent thrombosis in the patients who prematurely discontinued clopidogrel. Those who discontinued clopidogrel therapy were older (P = 0.02, more likely to be female (P = 0.02, single (P = 0.03, of lower economic (P < 0.05 and educational status (P < 0.01, more likely to have chronic disease (P = 0.04, less likely to have undergone previous stenting (P = 0.01, and were more likely to be receiving a larger number of drugs (P < 0.05. In multivariate analysis, low- or intermediate-economic status, no history of previous stent implantation, and total number of prescribed drugs using were factors independently associated with premature clopidogrel discontinuation. Conclusion: This study demonstrates several predictors of premature clopidogrel discontinuation. This data may help clinicians pay particular attention to these patients in an attempt to improve the outcomes of coronary stenting.

Discontinuation of Biologic Therapy in Rheumatoid Arthritis: Analysis from the Corrona RA Registry.

Science.gov (United States)

Strand, Vibeke; Miller, Paul; Williams, Setareh A; Saunders, Katherine; Grant, Shannon; Kremer, Joel

2017-12-01

Despite the availability of multiple effective therapies, discontinuation/switching of treatment is common for many patients with rheumatoid arthritis (RA). This study was designed to examine initiation of biologic disease-modifying anti-rheumatic drugs (bDMARDs) within the Consortium of Rheumatology Researchers of North America (Corrona) RA Registry, and characterize reasons for discontinuation. Inclusion criteria were: Corrona-registered adults (≥18 years) with RA (2002-2011); age of RA onset: ≥16 years; ≥6 months' follow-up after initiation of first/subsequent bDMARD. Patients receiving both tumor necrosis factor antagonists and non-TNF antagonists were included. Treatment discontinuation was defined as first report of stopping initial therapy or initiation of new bDMARD at/between visits, using a follow-up physician questionnaire. Overall, 6209 patients met inclusion criteria and 80.7% received TNF antagonists. Median time to discontinuation/change of therapy was 25.1 months (26.5 months with TNF antagonists vs. 20.5 months with non-TNF antagonists; log-rank p < 0.0001); 82.2, 67.3, and 51.1% of patients remained on therapy at 6, 12, and 24 months, respectively. Reasons for discontinuation were captured for 49.2% of patients, including: loss of efficacy (35.8%); physician preference (27.8%); safety (20.1%); patient preference (17.9%); and no access to treatment (9.0%). Baseline factors with greatest correlation to discontinuation were modified Health Assessment Questionnaire scores, patient-reported anxiety/depression, initiation of bDMARD treatment in 2007-2010 versus 2002-2003, and Clinical Disease Activity Index scores. Almost one-third of patients in the US discontinue currently available bDMARD therapies for RA by 12 months and almost half by 24 months, most commonly due to loss of efficacy. Corrona LLC and MedImmune.

Estimation of the Continuous and Discontinuous Leverage Effects.

Science.gov (United States)

Aït-Sahalia, Yacine; Fan, Jianqing; Laeven, Roger J A; Wang, Christina Dan; Yang, Xiye

2017-01-01

This paper examines the leverage effect, or the generally negative covariation between asset returns and their changes in volatility, under a general setup that allows the log-price and volatility processes to be Itô semimartingales. We decompose the leverage effect into continuous and discontinuous parts and develop statistical methods to estimate them. We establish the asymptotic properties of these estimators. We also extend our methods and results (for the continuous leverage) to the situation where there is market microstructure noise in the observed returns. We show in Monte Carlo simulations that our estimators have good finite sample performance. When applying our methods to real data, our empirical results provide convincing evidence of the presence of the two leverage effects, especially the discontinuous one.

Continuation versus discontinuation of oxytocin in the active phase of labour

DEFF Research Database (Denmark)

Bor, Isil Pinar; Ledertoug, Susanne; Boie, Sidsel

2016-01-01

. POPULATION: Women with singleton pregnancy in the vertex position undergoing labour induction or augmentation. METHODS: Two hundred women were randomised when cervical dilation was ≤4 cm to either continue or discontinue oxytocin infusion when cervical dilation reached 5 cm. MAIN OUTCOME MEASURES......, and neonatal outcomes. RESULTS: The active phase of labour was longer by 41 minutes (95% confidence interval 11-75 minutes) in the discontinued group (median 125 minutes in 85 women who had reached the active phase and delivered vaginally) versus the continued group (median 88 minutes in 78 women......OBJECTIVE: To investigate whether discontinuation of oxytocin infusion increases the duration of the active phase of labour and reduces maternal and neonatal complications. DESIGN: Randomised controlled trial. SETTING: Department of Obstetrics and Gynaecology, Regional Hospital of Randers, Denmark...

Discontinuity Preserving Image Registration through Motion Segmentation: A Primal-Dual Approach

Directory of Open Access Journals (Sweden)

Silja Kiriyanthan

2016-01-01

Full Text Available Image registration is a powerful tool in medical image analysis and facilitates the clinical routine in several aspects. There are many well established elastic registration methods, but none of them can so far preserve discontinuities in the displacement field. These discontinuities appear in particular at organ boundaries during the breathing induced organ motion. In this paper, we exploit the fact that motion segmentation could play a guiding role during discontinuity preserving registration. The motion segmentation is embedded in a continuous cut framework guaranteeing convexity for motion segmentation. Furthermore we show that a primal-dual method can be used to estimate a solution to this challenging variational problem. Experimental results are presented for MR images with apparent breathing induced sliding motion of the liver along the abdominal wall.

Pin cell discontinuity factors in the transient 3-D discrete ordinates code TORT-TD

International Nuclear Information System (INIS)

Seubert, A.

2010-01-01

Even with the rapid increase of computing power, whole core transient and accident analyses based on the direct solution of the 3-D neutron transport equation with a large number of energy groups and a detailed heterogeneous description of the core still remain computationally challenging. Current industrial methods for reactor core calculations therefore involve a two step approach in which lattice (assembly) depletion transport methods are used to prepare energy collapsed and fuel assembly or pin cell homogenized cross sections for subsequent whole core transport calculations. Spatial homogenization, in principal, requires the knowledge of both the actual boundary condition (local core environment) of the fuel assembly and the exact heterogeneous flux distribution (reference solution) of the whole core problem within that fuel assembly. Since, in particular, the latter is not known a priori, an infinite medium (zero net current) condition is used in the lattice calculations. It is well known that this approximation may lead to undesirable errors in cores in which large flux gradients are present across the fuel assemblies. This is the case in cores that have high heterogeneity and/or strong local absorbers, e.g. PWRs with partial MOX loading and inserted control rod clusters. There are two major approaches to mitigate spatial homogenization errors, superhomogenization (SPH) factors, and discontinuity factors within the scope of equivalence theory (ET) and generalized equivalence theory (GET). Although discontinuity factors are usually applied at the level of fuel assembly node size (assembly discontinuity factors, ADF), the methodology can be extended to pin cell homogenized whole core calculations involving pin cell discontinuity factors (PDF). There are also further developments for both the diffusion and the simplified transport (SP3) equation. In this paper, PDFs are introduced into the time-dependent 3-D discrete ordinates code TORT-TD in order to reduce the

Construct validity of 2 measures to assess reasons for antipsychotic discontinuation and continuation from patients’ and clinicians’ perspectives in a clinical trial

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Faries Douglas

2012-09-01

Full Text Available Abstract Background Little is known about the specific reasons for antipsychotic discontinuation or continuation from patients’ or clinicians’ perspectives. This study aimed to assess the construct validity of 2 new measures of the Reasons for Antipsychotic Discontinuation/Continuation (RAD: RAD-I (a structured interview assessing the patient’s perspective and RAD-Q (a questionnaire assessing the clinician’s perspective. Methods Data were used from a 12-week antipsychotic trial of schizophrenia patients in which the RAD was administered at study entry and at study completion (or discontinuation. Construct validity was assessed through comparisons of RAD responses, clinicians’ responses to a standard patient disposition form identifying reasons for patient’s study discontinuation, and several standard psychiatric measures. Percent agreement quantified the correspondence between patient and clinician scores. Results Patients indicating lack of improvement/worsening of positive symptoms as a ‘somewhat’ to ‘primary’ reason for medication discontinuation had statistically significantly less improvement in Positive and Negative Syndrome Scale positive score than patients not reporting these as a reason (concurrent validity. Similar results were observed for the RAD negative symptom, functional, social support, and adherence items, whereas the mood and cognitive items were not significantly associated with change scores on standard psychiatric measures. Responses to the RAD were also weakly associated with variables that theoretically should not be related to them (divergent validity. Level of agreement between the clinician- and patient-rated RAD scores was high (60%-100%. Conclusions Initial validation of the RAD suggests that the instruments are valid tools for gathering detailed information regarding reasons for antipsychotic discontinuation and continuation from patients’ and clinicians’ perspectives.

Forecasting Technological Discontinuities in the ICT Industry

DEFF Research Database (Denmark)

Hoisl, Karin; Stelzer, Tobias; Biala, Stefanie

2015-01-01

in the ICT industry. The conjoint approach allows for a simulation of the forecasting process and considers utility trade-offs. The results show that for both types of experts the perceived benefit of users most highly contributes to predicting technological discontinuities. Internal experts assign more...

Discontinuous movement of mRNP particles in nucleoplasmic regions devoid of chromatin

Science.gov (United States)

Siebrasse, Jan Peter; Veith, Roman; Dobay, Akos; Leonhardt, Heinrich; Daneholt, Bertil; Kubitscheck, Ulrich

2008-01-01

Messenger ribonucleoprotein particles (mRNPs) move randomly within nucleoplasm before they exit from the nucleus. To further understand mRNP trafficking, we have studied the intranuclear movement of a specific mRNP, the BR2 mRNP, in salivary gland cells in Chironomus tentans. Their polytene nuclei harbor giant chromosomes separated by vast regions of nucleoplasm, which allows us to study mRNP mobility without interference of chromatin. The particles were fluorescently labeled with microinjected oligonucleotides (DNA or RNA) complementary to BR2 mRNA or with the RNA-binding protein hrp36, the C. tentans homologue of hnRNP A1. Using high-speed laser microscopy, we followed the intranuclear trajectories of single mRNPs and characterized their motion within the nucleoplasm. The Balbiani ring (BR) mRNPs moved randomly, but unexpectedly, in a discontinuous manner. When mobile, they diffused with a diffusion coefficient corresponding to their size. Between mobile phases, the mRNPs were slowed down 10-to 250-fold but were never completely immobile. Earlier electron microscopy work has indicated that BR particles can attach to thin nonchromatin fibers, which are sometimes connected to discrete fibrogranular clusters. We propose that the observed discontinuous movement reflects transient interactions between freely diffusing BR particles and these submicroscopic structures. PMID:19074261

Structural characterization of dioscorin, the major tuber protein of yams, by near infrared Raman spectroscopy

International Nuclear Information System (INIS)

Liao, Y-H; Tseng, C-Y; Chen Wenlung

2006-01-01

As very little is known about the molecular structure of dioscorin, the major storage protein of yam tuber, we report here FT-Raman spectroscopic investigation of this yam protein isolated from D. alata L., for the first time. According to a series of purification and identification by ion-exchange chromatography, gel chromatography, SDS-PAGE, and MALDI-TOF-MS, it shows that the major storage protein is made up of dioscorin A (M.W. ∼33 kDa) and dioscorin B (M.W. ∼31 kDa). Raman spectral results indicate that the secondary structure of dioscorin A is major in α-helix, while dioscorin B belongs to anti-parallel β- sheet. It also shows that the microenvironment of major amino acids including tyrosine, phenylalanine, tryptophan, and methionine, and cysteine exhibit explicit differences between these two components. The conformation of disulfide bonding in dioscorin A predominates in Gauche-Gauche-Trans form, while Gauche-Gauche-Gauche and Trans-Gauche-Trans share the conformation in dioscorin B. Structural resemblance between dioscorin A and crude yam proteins implies that dioscorin A exhibits structural preference even though its content is lower than dioscorin B

Structural characterization of dioscorin, the major tuber protein of yams, by near infrared Raman spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Liao, Y-H [300 University Road, Department of Food Science, National Chiayi University, Chiayi, Taiwan (China); Tseng, C-Y [300 University Road, Department of Food Science, National Chiayi University, Chiayi, Taiwan (China); Chen Wenlung [Department of Chemistry, National Chiayi University, Chiayi, Taiwan (China)

2006-01-01

As very little is known about the molecular structure of dioscorin, the major storage protein of yam tuber, we report here FT-Raman spectroscopic investigation of this yam protein isolated from D. alata L., for the first time. According to a series of purification and identification by ion-exchange chromatography, gel chromatography, SDS-PAGE, and MALDI-TOF-MS, it shows that the major storage protein is made up of dioscorin A (M.W. {approx}33 kDa) and dioscorin B (M.W. {approx}31 kDa). Raman spectral results indicate that the secondary structure of dioscorin A is major in {alpha}-helix, while dioscorin B belongs to anti-parallel {beta}- sheet. It also shows that the microenvironment of major amino acids including tyrosine, phenylalanine, tryptophan, and methionine, and cysteine exhibit explicit differences between these two components. The conformation of disulfide bonding in dioscorin A predominates in Gauche-Gauche-Trans form, while Gauche-Gauche-Gauche and Trans-Gauche-Trans share the conformation in dioscorin B. Structural resemblance between dioscorin A and crude yam proteins implies that dioscorin A exhibits structural preference even though its content is lower than dioscorin B.

Structural characterization of dioscorin, the major tuber protein of yams, by near infrared Raman spectroscopy

Science.gov (United States)

Liao, Yu-Hsiu; Tseng, Chi-Yin; Chen, Wenlung

2006-01-01

As very little is known about the molecular structure of dioscorin, the major storage protein of yam tuber, we report here FT-Raman spectroscopic investigation of this yam protein isolated from D. alata L., for the first time. According to a series of purification and identification by ion-exchange chromatography, gel chromatography, SDS-PAGE, and MALDI-TOF-MS, it shows that the major storage protein is made up of dioscorin A (M.W. ~33 kDa) and dioscorin B (M.W. ~31 kDa). Raman spectral results indicate that the secondary structure of dioscorin A is major in α-helix, while dioscorin B belongs to anti-parallel β- sheet. It also shows that the microenvironment of major amino acids including tyrosine, phenylalanine, tryptophan, and methionine, and cysteine exhibit explicit differences between these two components. The conformation of disulfide bonding in dioscorin A predominates in Gauche-Gauche-Trans form, while Gauche-Gauche-Gauche and Trans-Gauche-Trans share the conformation in dioscorin B. Structural resemblance between dioscorin A and crude yam proteins implies that dioscorin A exhibits structural preference even though its content is lower than dioscorin B.

ADER discontinuous Galerkin schemes for general-relativistic ideal magnetohydrodynamics

Science.gov (United States)

Fambri, F.; Dumbser, M.; Köppel, S.; Rezzolla, L.; Zanotti, O.

2018-03-01

We present a new class of high-order accurate numerical algorithms for solving the equations of general-relativistic ideal magnetohydrodynamics in curved spacetimes. In this paper we assume the background spacetime to be given and static, i.e. we make use of the Cowling approximation. The governing partial differential equations are solved via a new family of fully-discrete and arbitrary high-order accurate path-conservative discontinuous Galerkin (DG) finite-element methods combined with adaptive mesh refinement and time accurate local timestepping. In order to deal with shock waves and other discontinuities, the high-order DG schemes are supplemented with a novel a-posteriori subcell finite-volume limiter, which makes the new algorithms as robust as classical second-order total-variation diminishing finite-volume methods at shocks and discontinuities, but also as accurate as unlimited high-order DG schemes in smooth regions of the flow. We show the advantages of this new approach by means of various classical two- and three-dimensional benchmark problems on fixed spacetimes. Finally, we present a performance and accuracy comparisons between Runge-Kutta DG schemes and ADER high-order finite-volume schemes, showing the higher efficiency of DG schemes.

Upper Mantle Discontinuities Underneath Central and Southern Mexico

Science.gov (United States)

Perez-Campos, X.; Clayton, R. W.

2011-12-01

Central and southern Mexico are affected by the subduction of Cocos plate beneath North American plate. The MesoAmerican Subduction Experiment (MASE) and the Veracruz-Oaxaca (VEOX) project have mapped the geometry of the Cocos slab. It is characterized in central Mexico by a shallow horizontal geometry up to ~300 km from the trench, then it dives steeply (70°) into the mantle, to its apparent end at 500 km depth. In contrast, some 400 km to the south, the slab subducts smoothly, with a dip angle of ~26° to a depth of 150 km. We use receiver functions from teleseismic events, recorded at stations from MASE, VEOX, and the Servicio Sismológico Nacional (SSN, Mexican National Seismological Service) to map the upper mantle discontinuities and properties of the transition zone in central and southern Mexico. We also use data from the Mapping the Rivera Subduction Zone (MARS) Experiment to get a complete picture of the subduction regime in central Mexico and compare the mantle transition zone in a slab tear regime. The 410 discontinuity shows significant variation in topography in central Mexico, particularly where the slab is expected to reach such depth. The 660 discontinuity shows a smoother topography, indicating that the slab does not penetrate this far down. The results will be compared with a ridge regime in the Gulf of California.

Mammographic density changes following discontinuation of tamoxifen in premenopausal women with oestrogen receptor-positive breast cancer.

Science.gov (United States)

Kim, Won Hwa; Cho, Nariya; Kim, Young-Seon; Yi, Ann

2018-04-06

To evaluate the changes in mammographic density after tamoxifen discontinuation in premenopausal women with oestrogen receptor-positive breast cancers and the underlying factors METHODS: A total of 213 consecutive premenopausal women with breast cancer who received tamoxifen treatment after curative surgery and underwent three mammograms (baseline, after tamoxifen treatment, after tamoxifen discontinuation) were included. Changes in mammographic density after tamoxifen discontinuation were assessed qualitatively (decrease, no change, or increase) by two readers and measured quantitatively by semi-automated software. The association between % density change and clinicopathological factors was evaluated using univariate and multivariate regression analyses. After tamoxifen discontinuation, a mammographic density increase was observed in 31.9% (68/213, reader 1) to 22.1% (47/213, reader 2) by qualitative assessment, with a mean density increase of 1.8% by quantitative assessment compared to density before tamoxifen discontinuation. In multivariate analysis, younger age (≤ 39 years) and greater % density decline after tamoxifen treatment (≥ 17.0%) were independent factors associated with density change after tamoxifen discontinuation (p density change with a mean density increase of 1.8%, which was associated with younger age and greater density change after tamoxifen treatment. • Increased mammographic density after tamoxifen discontinuation can occur in premenopausal women. • Mean density increase after tamoxifen discontinuation was 1.8%. • Density increase is associated with age and density decrease after tamoxifen.

Interface discontinuity factors in the modal Eigenspace of the multigroup diffusion matrix

International Nuclear Information System (INIS)

Garcia-Herranz, N.; Herrero, J.J.; Cuervo, D.; Ahnert, C.

2011-01-01

Interface discontinuity factors based on the Generalized Equivalence Theory are commonly used in nodal homogenized diffusion calculations so that diffusion average values approximate heterogeneous higher order solutions. In this paper, an additional form of interface correction factors is presented in the frame of the Analytic Coarse Mesh Finite Difference Method (ACMFD), based on a correction of the modal fluxes instead of the physical fluxes. In the ACMFD formulation, implemented in COBAYA3 code, the coupled multigroup diffusion equations inside a homogenized region are reduced to a set of uncoupled modal equations through diagonalization of the multigroup diffusion matrix. Then, physical fluxes are transformed into modal fluxes in the Eigenspace of the diffusion matrix. It is possible to introduce interface flux discontinuity jumps as the difference of heterogeneous and homogeneous modal fluxes instead of introducing interface discontinuity factors as the ratio of heterogeneous and homogeneous physical fluxes. The formulation in the modal space has been implemented in COBAYA3 code and assessed by comparison with solutions using classical interface discontinuity factors in the physical space. (author)

14 CFR 170.25 - LORAN-C discontinuance criteria.

Science.gov (United States)

2010-01-01

... nonprecision approach may be subject to discontinuance when the present value of the continued maintenance costs (PVCM) of the LORAN-C approach exceed the present value of its remaining life-cycle benefits (PVB...

A contactless positioning system for monitoring discontinuities in three dimensions with geological and geotechnical applications

Czech Academy of Sciences Publication Activity Database

Rinaldi-Montes, N.; Rowberry, Matthew David; Frontera, C.; Baroň, I.; Garcés, G.; Blahůt, Jan; Pérez-López, R.; Pennos, C.; Martí, Xavier

2017-01-01

Roč. 88, č. 7 (2017), č. článku 074501. ISSN 0034-6748 R&D Projects: GA MŠk LM2010008 Institutional support: RVO:67985891 ; RVO:68378271 Keywords : mechanical discontinuities * contactless positioning system * magnetoresistive sensing * geotechnical engineering * structural health monitoring Subject RIV: JB - Sensors, Measurment, Regulation; BM - Solid Matter Physics ; Magnetism (FZU-D) OBOR OECD: Environmental and geological engineering , geotechnics; Condensed matter physics (including formerly solid state physics, supercond.) (FZU-D) Impact factor: 1.515, year: 2016

Innovation at the end of the life cycle : discontinuous innovation strategies by incumbents

NARCIS (Netherlands)

Kishna, M.; Negro, S.O.; Alkemade, F.; Hekkert, M.

2017-01-01

This paper focuses on the strategies of incumbents that seek to develop discontinuous innovations within the boundaries of a mature innovation system. Mature innovation systems do not provide support for these discontinuous innovations. This article focuses on exploring why incumbents in these

Measurement of a discontinuous object based on a dual-frequency grating

Institute of Scientific and Technical Information of China (English)

Qiao Nao-Sheng; Cai Xin-Hua; Yao Chun-Mei

2009-01-01

The dual-frequency grating measurement theory is proposed in order to carry out the measurement of a discontinuous object. Firstly, the reason why frequency spectra are produced by low frequency gratings and high frequency gratings in the field of frequency is analysed, and the relationship between the wrapped-phase and the unwrappingphase is discussed. Secondly, a method to combine the advantages of the two kinds of gratings is proposed: one stripe is produced in the mutation part of the object measured by a suitable low frequency grating designed by MATLAB, then the phase produced by the low frequency grating need not be unfolded. The integer series of stripes is produced by a high frequency grating designed by MATLAB based on the frequency ratio of the two kinds of gratings and the high frequency wrapped-phase, and the high frequency unwrapping-phase is then obtained. In order to verify the correctness of the theoretical analysis, a steep discontinuous object of 600×600 pixels and 10.00 mm in height is simulated and a discontinuous object of ladder shape which is 32.00 mm in height is used in experiment. Both the simulation and the experiment can restore the discontinuous object height accurately by using the dual-frequency grating measurement theory.

Discontinuous conduction mode analysis of phase-modulated series ...

Indian Academy of Sciences (India)

modulated dc–dc series resonant converter (SRC) operating in discontinuous conduction mode (DCM). The conventional fundamental harmonic approximation technique is extended for a non-ideal series resonant tank to clarify the limitations of ...

Functional and structural brain correlates of risk for major depression in children with familial depression

Directory of Open Access Journals (Sweden)

Xiaoqian J. Chai

2015-01-01

Full Text Available Despite growing evidence for atypical amygdala function and structure in major depression, it remains uncertain as to whether these brain differences reflect the clinical state of depression or neurobiological traits that predispose individuals to major depression. We examined function and structure of the amygdala and associated areas in a group of unaffected children of depressed parents (at-risk group and a group of children of parents without a history of major depression (control group. Compared to the control group, the at-risk group showed increased activation to fearful relative to neutral facial expressions in the amygdala and multiple cortical regions, and decreased activation to happy relative to neutral facial expressions in the anterior cingulate cortex and supramarginal gyrus. At-risk children also exhibited reduced amygdala volume. The extensive hyperactivation to negative facial expressions and hypoactivation to positive facial expressions in at-risk children are consistent with behavioral evidence that risk for major depression involves a bias to attend to negative information. These functional and structural brain differences between at-risk children and controls suggest that there are trait neurobiological underpinnings of risk for major depression.

Reasons for lithium discontinuation in men and women with bipolar disorder: a retrospective cohort study.

Science.gov (United States)

Öhlund, Louise; Ott, Michael; Oja, Sofia; Bergqvist, Malin; Lundqvist, Robert; Sandlund, Mikael; Salander Renberg, Ellinor; Werneke, Ursula

2018-02-07

Lithium remains first choice as maintenance treatment for bipolar affective disorder. Yet, about half of all individuals may stop their treatment at some point, despite lithium's proven benefits concerning the prevention of severe affective episodes and suicide. Retrospective cohort study in the Swedish region of Norrbotten into the causes of lithium discontinuation. The study was set up to (1) test whether patients with bipolar affective disorder or schizoaffective disorder, treated with lithium maintenance therapy, were more likely to discontinue lithium because of adverse effects than lack of therapeutic effectiveness, (2) explore gender differences, (3) understand the role of diagnosis and (4) identify who, patient or doctor, took the initiative to stop lithium. Review of medical records for all episodes of lithium discontinuation that had occurred between 1997 and 2013 with the intent to stop lithium for good. Of 873 patients treated with lithium, 54% discontinued lithium, corresponding to 561 episodes of lithium discontinuation. In 62% of episodes, lithium was discontinued due to adverse effects, in 44% due to psychiatric reasons, and in 12% due to physical reasons interfering with lithium treatment. The five single most common adverse effects leading to lithium discontinuation were diarrhoea (13%), tremor (11%), polyuria/polydipsia/diabetes insipidus (9%), creatinine increase (9%) and weight gain (7%). Women were as likely as men to take the initiative to stop lithium, but twice as likely to consult a doctor before taking action (p < 0.01). Patients with type 1 BPAD or SZD were more likely to discontinue lithium than patients with type 2 or unspecified BPAD (p < 0.01). Patients with type 1 BPAD or SZD were more likely to refuse medication (p < 0.01). Conversely, patients with type 2 or unspecified BPAD were three times as likely to discontinue lithium for lack or perceived lack of effectiveness (p < 0.001). Stopping lithium treatment is

Increments in plasma homovanillic acid concentrations after neuroleptic discontinuation are associated with worsening of schizophrenic symptoms.

Science.gov (United States)

Khan, R S; Amin, F; Powchik, P; Knott, P; Goldstein, M; Apter, S; Kerman, B; Jaff, S; Davidson, M

1990-01-01

1. Thirty-two male schizophrenic patients participated in this study. 2. Plasma concentrations of the dopamine metabolite, homovanillic acid (pHVA) were assessed once on neuroleptic medication and twice a week for a maximum of six weeks after its discontinuation. 3. Psychiatric symptomatology was assessed once on neuroleptic medication and once a week for a maximum of six weeks after its discontinuation, using the brief psychiatric rating scale (BPRS). 4. pHVA and total BPRS score increased significantly after discontinuation of neuroleptic as compared to baseline. 5. The magnitude of pHVA and BPRS increments after discontinuation of neuroleptic correlated significantly. 6. Results of this study suggest that worsening of schizophrenic symptoms after discontinuation of neuroleptic treatment is associated with increased pHVA concentrations.

Lyophilized allogeneic bone grafts for cystic and discontinuity defects of the jaws

International Nuclear Information System (INIS)

Pill Hoon Choung; Eun Seok Kim

1999-01-01

Allogenic bone grafts have been used after various processing in each institute was made by lyophilized allogenic bone and used for maxillofacial reconstruction. Three types of lyophilized allogenic bone grafts as powder, chip and block form were performed to reconstruct the following defects: 1) maxillectomy, 2) mandiblectomy, 3) cystectomy, 4) cleft alveolus, 5) gap in orthognathic osteotomy, 6) peri-implant defect, 7) extraction socket, and 8) facial contouring. Above defects can be classified as cystic and discontinuity defects of the maxilia and the mandible. Because discontinuity defects have more difficult problems to reconstruct considering mechanical strength of the allogenic bone. We performed allogenic bone grafts on 50 cystic defects and 12 discontinuity defects of the jaws. Among them, 3 cases were removed due to infection, and the others had no complications. In reconstruction of cystic defects, the defects were filled with allogenic chip which were made from allogenic block bone at the surgery, which later were changed to host bone. Three cases of them showed tooth eruption through the allogenic bone grafting site, changing the eruption pathway, which was interrupted by the lesion. in reconstruction of discontinuity defects, usually allogenic bone has been used as a tray, in which PMCB or demineralized bone chips were filled. But we tried to reconstruct this discontinuity defect using allogeneic bone block without inside filling of PMCB different from tray type. We will present the results of allogenic bone grafts using cranial bone, costochondral graft, and the mandible

HIV Prevention After Discontinuing Pre-Exposure Prophylaxis: Conclusions From a Case Study

Directory of Open Access Journals (Sweden)

Kai J. Jonas

2018-05-01

Full Text Available Pre-exposure prophylaxis (PrEP with tenofovir disoproxil fumarate in combination with emtricitabine (FTC is a highly effective form of HIV prevention. Endeavors of health-care providers and activists in many countries over the world are directed at making access to PrEP possible, or increasing PrEP use among men-who-have-sex-with-men (MSM. We argue while this effort is necessary, we also need to consider modes of HIV prevention after a period of PrEP use. PrEP uptake is not a one-way street, meaning that individuals may discontinue PrEP use, either voluntarily and involuntarily. Voluntary discontinued PrEP use in conjunction with decreased or no HIV risk exposure is unproblematic, but involuntary discontinuations with continuous high level of HIV risk exposure calls for tailored post-PrEP use HIV prevention. We present a case study of an MSM individual who discontinued PrEP for medical reasons (renal function and seroconverted soon afterward, to illustrate the need for tailored HIV prevention post-PrEP. Furthermore, we provide additional contexts of PrEP discontinuation leading to populations that are in need for post-PrEP types of HIV prevention. Subsequently, we present suggestions for modes of post-PrEP HIV prevention based on knowledge–communication–choice model. Community organization and health-care providers should consider and prepare their HIV prevention consulting protocols for such types of clients and add post-PrEP HIV prevention measures to their consulting offer.

Cognitive function and discontinuation of adjuvant hormonal therapy in older breast cancer survivors: CALGB 369901 (Alliance).

Science.gov (United States)

Bluethmann, Shirley M; Alfano, Catherine M; Clapp, Jonathan D; Luta, George; Small, Brent J; Hurria, Arti; Cohen, Harvey J; Sugarman, Steven; B Muss, Hyman; Isaacs, Claudine; Mandelblatt, Jeanne S

2017-10-01

To investigate the effects of cognitive function on discontinuation of hormonal therapy in breast cancer survivors ages 65+ ("older"). Older breast cancer survivors with invasive, non-metastatic disease, and no reported cognitive difficulties were recruited from 78 Alliance sites between 2004 and 2011. Eligible survivors (n = 1280) completed baseline interviews; follow-up was conducted annually for up to 7 years. Survivors with estrogen-receptor-positive (ER+) cancers who initiated hormonal therapy (n = 990) were included. Self-reported cognitive function was measured using the EORTC-QLQ30 scale; a difference of eight points on the 0-100 scale was considered clinically significant. Based on varying rates of discontinuation over time, discontinuation was evaluated separately for three time periods: early (3-5 years). Cox models for each time period were used to evaluate the effects of cognition immediately preceding discontinuation, controlling for age, chemotherapy, and other covariates. Survivors were 65-91 years old (mean 72.6 years), and 79% had stages 1 or 2A disease. Overall, 43% discontinued hormonal therapy before 5 years. Survivors who reported lower cognitive function in the period before discontinuation had greater hazards of discontinuing therapy at the treatment midpoint (HR 1.22 per 8-point difference, CI 1.09-1.40, p cognition was not related to discontinuation in the other periods. Self-reported cognitive problems were a significant risk factor for discontinuation of hormonal therapy 1-3 years post-initiation. Additional research is needed on the temporality of cognitive effects and hormonal therapy to support survivorship care needs of older survivors.

Discontinuous precipitation in cobalt-tungsten alloys

International Nuclear Information System (INIS)

Zieba, P.; Cliff, G.; Lorimer, G.W.

1997-01-01

Discontinuous precipitation in a Co32 wt% W alloy aged in the temperature range from 875 K to 1025 K has been investigated. Philips EM 430 STEM has been used to characterize the microstructure and to measure the composition profiles across individual lamellae of ε Co and Co 3 W phases in partially transformed specimens. Two kinds of cellular precipitates have been found in the alloy. The initial transformation product, identified as primary lamellae with spacing of a few nanometers is replaced during prolonged ageing by secondary lamellae with a much larger interlamellar spacing, typically a few tens of nm. Line scans across cell boundaries of the primary lamellae revealed that, just behind the advancing cell boundary, the solute content is far from the equilibrium state. This solute excess within the cells is quickly removed at the ageing temperature. Calculations show that the diffusion process was too rapid to be identified as ordinary volume diffusion. Investigation of the kinetics showed that discontinuous precipitation is controlled by diffusion processes at the advancing cell boundary. This proposal has been confirmed by STEM analysis of tungsten profiles in the depleted ε Co lamellae

Clinical features of HBV-associated acute-on-chronic liver failure induced by discontinuation of nucleoside analogues

Directory of Open Access Journals (Sweden)

LIU Xiaoyan

2016-09-01

Full Text Available Objective To investigate the clinical features of patients with HBV-associated acute-on-chronic liver failure (HBV-ACLF induced by the discontinuation of necleos(tide analogues. Methods A retrospective analysis was performed for 698 patients with a definite diagnosis of HBV-ACLF in The 302 Hospital of PLA from January 2014 to April 2016, and among these patients, 150 (discontinuation group had acute-on-chronic liver failure (ACLF induced by discontinuation, 396 (previously untreated group had not received antiviral therapy when they developed this disease for the first time, and the other 152 patients with ACLF caused by other reasons were enrolled as controls. The causative factors, underlying diseases, family history, serum hepatitis B markers, prognosis, and initial onset were summarized, and the drugs used and discontinuation time were recorded for patients who stopped taking necleos(tide analogues. The chi-square test was used for the comparison of categorical data between groups. Results Among the 698 patients, 355(50.86% had a family history of chronic hepatitis B (CHB, and 93 patients (62.00% in the discontinuation group had a family history of CHB. Among the 150 patients in the discontinuation group, 27 (18.00% had an underlying disease of chronic hepatitis, among whom 12 (44.44% had a family history of CHB, which was significantly lower than the overall level (χ2=2.57, P=0.07; 123 (82.00% had an underlying disease of liver cirrhosis (compensated, among whom 81 (65.85% had a family history of CHB, which was significantly higher than the overall level (χ2=48.77, P＜0.001. Of all the patients in the discontinuation group, 77.33% (116/150 developed the disease within 1 year after discontinuation, and 21.33% (32/150developed the disease during the second year after discontinuation. The HBeAg-negative patients accounted for 47.33% (71/150. In the discontinuation group and previously untreated group, the patients with an underlying disease

Microstructure and orientation effects on properties of discontinuous silicon carbide/aluminum composites

Science.gov (United States)

Mcdanels, D. L.; Hoffman, C. A.

1984-01-01

Composite panels containing up to 40 vol % discontinuous silicon carbide SiC whisker, nodule, or particulate reinforcement in several aluminum matrices are commercially fabricated and the mechanical properties and microstructual characteristics are evaluated. The yield and tensile strengths and the ductility are controlled primarily by the matrix alloy, the temper condition, and the reinforcement content. Particulate and nodule reinforcements are as effective as whisker reinforcement. Increased ductility is attributed to purer, more uniform starting materials and to more mechanical working during fabrication. Comparing mechanical properties with those of other aluminum alloys shows that these low cost, lightweight composites demonstrate very good potential for application to aerospace structures.

Model of discontinuous plastic flow at temperature close to absolute zero

CERN Document Server

Marcinek, Dawid Jarosław; Sgobba, Stefano

In the present study cryogenic tensile tests performed on different materials (316LN, JK2LB) were used. The discontinuous plastic flow phenomenon was analysed, in order to develop a constitutive model of serrated yielding as a support for analysis of structural materials at low temperatures. Devices and structures, cooled be means of liquid helium, operate at the temperatures equal or lower than 4.2 K, which for the examined materials is below the transition threshold between screw and edge dislocations. It is considered a threshold for the appearance of DPF consisting in cyclic drop of load followed by deformation jumps and generation of heat. Temperature oscillations resulting from the thermodynamic instability in stainless steel can be of the order of dT = 40 K, which is exceptionally dangerous for superconducting cables. Suitably calibrated numerical algorithm allows prediction of the behaviour of the material subjected to deformation at low temperatures. The issues presented in the present study are curr...

Super-convergence of Discontinuous Galerkin Method Applied to the Navier-Stokes Equations

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Atkins, Harold L.

2009-01-01

The practical benefits of the hyper-accuracy properties of the discontinuous Galerkin method are examined. In particular, we demonstrate that some flow attributes exhibit super-convergence even in the absence of any post-processing technique. Theoretical analysis suggest that flow features that are dominated by global propagation speeds and decay or growth rates should be super-convergent. Several discrete forms of the discontinuous Galerkin method are applied to the simulation of unsteady viscous flow over a two-dimensional cylinder. Convergence of the period of the naturally occurring oscillation is examined and shown to converge at 2p+1, where p is the polynomial degree of the discontinuous Galerkin basis. Comparisons are made between the different discretizations and with theoretical analysis.

Mg2+ in the major groove modulates B-DNA structure and dynamics.

Directory of Open Access Journals (Sweden)

Marc Guéroult

Full Text Available This study investigates the effect of Mg(2+ bound to the DNA major groove on DNA structure and dynamics. The analysis of a comprehensive dataset of B-DNA crystallographic structures shows that divalent cations are preferentially located in the DNA major groove where they interact with successive bases of (A/GpG and the phosphate group of 5'-CpA or TpG. Based on this knowledge, molecular dynamics simulations were carried out on a DNA oligomer without or with Mg(2+ close to an ApG step. These simulations showed that the hydrated Mg(2+ forms a stable intra-strand cross-link between the two purines in solution. ApG generates an electrostatic potential in the major groove that is particularly attractive for cations; its intrinsic conformation is well-adapted to the formation of water-mediated hydrogen bonds with Mg(2+. The binding of Mg(2+ modulates the behavior of the 5'-neighboring step by increasing the BII (ε-ζ>0° population of its phosphate group. Additional electrostatic interactions between the 5'-phosphate group and Mg(2+ strengthen both the DNA-cation binding and the BII character of the 5'-step. Cation binding in the major groove may therefore locally influence the DNA conformational landscape, suggesting a possible avenue for better understanding how strong DNA distortions can be stabilized in protein-DNA complexes.

Modelling discontinuous well log signal to identify lithological ...

Indian Academy of Sciences (India)

1Indian School of Mines (ISM), Dhanbad 826 004, India. ... new wavelet transform-based algorithm to model the abrupt discontinuous changes from well log data by taking care of ...... the 11th ACM International Conference on Multimedia,.

Priapism Followed by Discontinuation of Methadone: A rare Case Report

Directory of Open Access Journals (Sweden)

Seyed-Ali Mostafavi

2015-10-01

Full Text Available Objective: Priapism is defined by persistent, painful penile erection which occurs without sexual stimulation. Methadone is used as an analgesic and is also used in detoxification and maintenance protocol for opioid dependence treatment. Here we will report a case of a male with priapism after rapid discontinuation doses of methadone.Case presentation: The case was a young married male who referred to a psychiatry clinic due to long-time spontaneous erections. The patient had no history of mental disorders, trauma or sickle cell anemia. He used to smoke opium for five years and used methadone for four years at a dose of 17 cc daily, which he abruptly discontinued. Then he often experienced spontaneous and painful erections without physical or mental stimulation that caused him shame and embarrassment .Conclusion: In this case, chronology indicates that rapid discontinuation of methadone was possibly responsible for the occurrence of priapism. This may have happened due to a compensatory reaction to methadone side effect of erectile dysfunction, followed by its rapid withdrawal.

Mechanical Properties of Discontinuous Precipitated Al-Zn Alloys after Drawing at Room and Cryogenic Temperatures

Energy Technology Data Exchange (ETDEWEB)

Kim, Min Soo; Lee, Jehyun [Changwon National University, Changwon (Korea, Republic of); Han, Seung Zeon; Ahn, Jee Hyuk [Korea Institute of Materials Science, Changwon (Korea, Republic of); Lim, Sung Hwan [Kangwon National University, Chuncheon (Korea, Republic of); Kim, Kwang Ho [Pusan National University, Pusan (Korea, Republic of); Kim, Sang sik [Gyeongsang National University, Jinju (Korea, Republic of)

2017-02-15

In order to study the effect of microstructural change on the tensile properties of discontinuous precipitated Al-Zn binary alloy, four different Al-Zn alloys(25, 30, 35, 45 wt%Zn) were aged at 160 ℃ for different aging times(0, 5, 15, 30, 60, 120, 360 min) after being solution treated at 400 ℃, and successively drawn at room and cryogenic temperatures(-197 ℃). Discontinuous precipitation was formed during aging in the Al matrix(which contained more than 30 wt%Zn) in Al alloys containing more than 30 wt%Zn. The tensile strength of continuous precipitated Al-35Zn alloy decreased with increasing drawing ratio, however, the tensile strength of discontinuous precipitated Al-35Zn alloy increased with further drawing. The strength and ductility combination, 350 MPa-36%was achieved by drawning discontinuous precipitated Al-Zn alloy at room temperature. The discontinuous precipitated Al-Zn alloy drawn at cryogenic temperature showed a higher value of tensile strength, over 500 MPa, although ductility decreased.

Mechanical Properties of Discontinuous Precipitated Al-Zn Alloys after Drawing at Room and Cryogenic Temperatures

International Nuclear Information System (INIS)

Kim, Min Soo; Lee, Jehyun; Han, Seung Zeon; Ahn, Jee Hyuk; Lim, Sung Hwan; Kim, Kwang Ho; Kim, Sang sik

2017-01-01

In order to study the effect of microstructural change on the tensile properties of discontinuous precipitated Al-Zn binary alloy, four different Al-Zn alloys(25, 30, 35, 45 wt%Zn) were aged at 160 ℃ for different aging times(0, 5, 15, 30, 60, 120, 360 min) after being solution treated at 400 ℃, and successively drawn at room and cryogenic temperatures(-197 ℃). Discontinuous precipitation was formed during aging in the Al matrix(which contained more than 30 wt%Zn) in Al alloys containing more than 30 wt%Zn. The tensile strength of continuous precipitated Al-35Zn alloy decreased with increasing drawing ratio, however, the tensile strength of discontinuous precipitated Al-35Zn alloy increased with further drawing. The strength and ductility combination, 350 MPa-36%was achieved by drawning discontinuous precipitated Al-Zn alloy at room temperature. The discontinuous precipitated Al-Zn alloy drawn at cryogenic temperature showed a higher value of tensile strength, over 500 MPa, although ductility decreased.

Continuous versus discontinuous albedo representations in a simple diffusive climate model

Science.gov (United States)

Simmons, P. A.; Griffel, D. H.

1988-07-01

A one-dimensional annually and zonally averaged energy-balance model, with diffusive meridional heat transport and including icealbedo feedback, is considered. This type of model is found to be very sensitive to the form of albedo used. The solutions for a discontinuous step-function albedo are compared to those for a more realistic smoothly varying albedo. The smooth albedo gives a closer fit to present conditions, but the discontinuous form gives a better representation of climates in earlier epochs.

Propagation of Boundary-Induced Discontinuity in Stationary Radiative Transfer

Science.gov (United States)

Kawagoe, Daisuke; Chen, I.-Kun

2018-01-01

We consider the boundary value problem of the stationary transport equation in the slab domain of general dimensions. In this paper, we discuss the relation between discontinuity of the incoming boundary data and that of the solution to the stationary transport equation. We introduce two conditions posed on the boundary data so that discontinuity of the boundary data propagates along positive characteristic lines as that of the solution to the stationary transport equation. Our analysis does not depend on the celebrated velocity averaging lemma, which is different from previous works. We also introduce an example in two dimensional case which shows that piecewise continuity of the boundary data is not a sufficient condition for the main result.

Antipsychotic discontinuation syndromes: a narrative review of the evidence and its integration into Australian mental health nursing textbooks.

Science.gov (United States)

Salomon, Carmela; Hamilton, Bridget

2014-02-01

In light of the high number of people discontinuing antipsychotics each year, it is essential that nurses develop a robust understanding of all aspects of the discontinuation experience. While there is a large body of published work documenting post-discontinuation relapse rates, less is known about other aspects of the discontinuation experience. This paper presents the results of a narrative review of international studies of antipsychotic discontinuation syndromes and their relevance to nursing practice. Four key mental health nursing textbooks used in student nurse education in Australia are examined to assess how this evidence has been incorporated into clinical recommendations. This review finds that the evidence for discontinuation syndromes could be more widely disseminated and applied than it is at present. Strikingly, this evidence has not been incorporated into key mental health nursing textbooks in Australia at all. Slow integration into nursing published work may be influenced by a number of clinical and research uncertainties. We consider the impact of this silence on key nursing roles of psycho-education and adverse event monitoring during antipsychotic discontinuation periods. Further robust research should be conducted into discontinuation syndromes as a matter of urgency. Given the high number of consumers potentially impacted upon by discontinuation syndromes, nurse authors and educators should consider revising key nursing textbooks to include the currently available information about discontinuation syndromes. © 2012 The Authors; International Journal of Mental Health Nursing © 2012 Australian College of Mental Health Nurses Inc.

Levy's distributions for statistical description of fractal structures; discontinuous metal films on dielectric substrates

International Nuclear Information System (INIS)

Dobierzewska-Mozrzymas, E.; Szymczak, G.; Bieganski, P.; Pieciul, E.

2003-01-01

The ranges of statistical description of the systems may be determined on the basis of the inverse power law of the Mandelbrot. The slope of the straight line representing the power law in a double-logarithmic plot, determined as -1/μ (μ being a critical exponent), characterizes the distribution of elements in the system. In this paper, the inverse power law is used to describe the statistical distribution of discontinuous metal films with higher coverage coefficients (near percolation threshold). For these films the critical exponent μ∼1, both the mean value and the variance are infinite. The objects with such microstructure are described according to the Levy distribution; Cauchy, inverse Gauss and inverse gamma distribution, respectively. The experimental histograms are compared with the calculated ones. Inhomogeneous metal films were obtained experimentally, their microstructures were examined by means of electron microscope. On the basis of electron micrographs, the fractal dimensions were determined for the metal films with coverage coefficient ranging from 0.35 to 1.00

Contraceptive discontinuation and switching among Ghanaian women: evidence from the Ghana Demographic and Health Survey, 2008.

Science.gov (United States)

Modey, Emefa J; Aryeetey, Richmond; Adanu, Richard

2014-03-01

This study identifies factors associated with contraceptive discontinuation and switching among Ghanaian women of reproductive age, using data from 1,378 female respondents of the 2008 Ghana Demographic and Health Survey. Logistic regression models were used to determine relationships between key socio-demographic factors and user status. Discontinued use occurred among 56% of ever users and switching among 55% of current users. The IUD was most abandoned (70%) and its use was associated with almost twice the odds of discontinuation (OR = 1.97; 95% CI (1.04, 3.75)). Having a history of terminated pregnancy significantly predicted both discontinuation (OR = 1.36; 95% CI (1.03, 1.79) and switching (OR = 1.78; 95% CI (1.16, 2.73)) and intention to limit births significantly predicted lower discontinuation (OR = 0.71; 95% CI (0.52, 0.96)). Counseling services emphasizing contraceptive options and reinforcing switching are critically needed to reduce unwanted pregnancies that may result from poor method use and discontinuation especially among post-abortion clients and IUD users.

Periodic synchronization control of discontinuous delayed networks by using extended Filippov-framework.

Science.gov (United States)

Cai, Zuowei; Huang, Lihong; Guo, Zhenyuan; Zhang, Lingling; Wan, Xuting

2015-08-01

This paper is concerned with the periodic synchronization problem for a general class of delayed neural networks (DNNs) with discontinuous neuron activation. One of the purposes is to analyze the problem of periodic orbits. To do so, we introduce new tools including inequality techniques and Kakutani's fixed point theorem of set-valued maps to derive the existence of periodic solution. Another purpose is to design a switching state-feedback control for realizing global exponential synchronization of the drive-response network system with periodic coefficients. Unlike the previous works on periodic synchronization of neural network, both the neuron activations and controllers in this paper are allowed to be discontinuous. Moreover, owing to the occurrence of delays in neuron signal, the neural network model is described by the functional differential equation. So we introduce extended Filippov-framework to deal with the basic issues of solutions for discontinuous DNNs. Finally, two examples and simulation experiments are given to illustrate the proposed method and main results which have an important instructional significance in the design of periodic synchronized DNNs circuits involving discontinuous or switching factors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Discontinuation of tofacitinib after achieving low disease activity in patients with rheumatoid arthritis: a multicentre, observational study.

Science.gov (United States)

Kubo, Satoshi; Yamaoka, Kunihiro; Amano, Koichi; Nagano, Shuji; Tohma, Shigeto; Suematsu, Eiichi; Nagasawa, Hayato; Iwata, Kanako; Tanaka, Yoshiya

2017-08-01

To determine whether tofacitinib can be discontinued in patients with RA who achieve low disease activity (LDA). RA patients with LDA after tofacitinib treatment in a phase III and long-term extension study were enrolled in this multicentre, non-randomized, open, prospective, observational study. The decision of discontinuation or continuation of tofacitinib was determined based on patient-physician decision making with informed consent. The primary endpoint was the proportion of patients who remained tofacitinib-free at post-treatment week 52. Clinical outcome was compared between those who continued and those who discontinued tofacitinib. The last observation carried forward method was used for patients who could not discontinue tofacitinib before week 52. Of 64 patients, 54 discontinued and 10 continued tofacitinib therapy. At post-treatment week 52, 20 of the 54 patients (37%) of the discontinuation group remained tofacitinib-free without disease flare. Disease activity at post-treatment week 52 was higher in the discontinuation group than the continuation group. Among the discontinuation group, the RF titre at baseline was significantly lower in patients who remained tofacitinib-free than those who did not (40 vs 113 U/ml). In fact, a higher proportion of patients with lower RF remained tofacitinib-free at week 52 compared with those with higher RF at baseline. In patients who could not achieve tofacitinib-free status, re-initiation of tofacitinib or other biologics improved disease activity. It is possible to discontinue tofacitinib without flare in about a third of patients with RA. A low RF predicts maintenance of LDA after discontinuation of tofacitinib. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Discontinuous gas exchange, water loss, and metabolism in Protaetia cretica (Cetoniinae, Scarabaeidae).

Science.gov (United States)

Matthews, Philip G D; White, Craig R

2012-01-01

Insects are at high risk of desiccation because of their small size, high surface-area-to-volume ratio, and air-filled tracheal system that ramifies throughout their bodies to transport O(2) and CO(2) to and from respiring cells. Although the tracheal system offers a high-conductance pathway for the movement of respiratory gases, it has the unintended consequence of allowing respiratory transpiration to the atmosphere. When resting, many species exchange respiratory gases discontinuously, and an early hypothesis for the origin of these discontinuous gas exchange cycles (DGCs) is that they serve to reduce respiratory water loss. In this study, we test this "hygric" hypothesis by comparing rates of CO(2) exchange and water loss among flower beetles Protaetia cretica (Cetoniinae, Scarabaeidae) breathing either continuously or discontinuously. We show that, consistent with the expectations of the hygric hypothesis, rates of total water loss are higher during continuous gas exchange than during discontinuous gas exchange and that the ratio of respiratory water loss to CO(2) exchange is lower during discontinuous gas exchange. This conclusion is in agreement with other studies of beetles and cockroaches that also support the hygric hypothesis. However, this result does not exclude other adaptive hypotheses supported by work on ants and moth pupae. This ambiguity may arise because there are multiple independent evolutionary origins of DGCs and no single adaptive function underlying their genesis. Alternatively, the observed reduction in water loss during DGCs may be a side effect of a nonadaptive gas exchange pattern that is elicited during periods of inactivity.

Discontinuities concentrate mobile predators: Quantifying organism-environment interactions at a seascape scale

Science.gov (United States)

Kennedy, Christina G.; Mather, Martha E.; Smith, Joseph M.; Finn, John T.; Deegan, Linda A.

2016-01-01

Understanding environmental drivers of spatial patterns is an enduring ecological problem that is critical for effective biological conservation. Discontinuities (ecologically meaningful habitat breaks), both naturally occurring (e.g., river confluence, forest edge, drop-off) and anthropogenic (e.g., dams, roads), can influence the distribution of highly mobile organisms that have land- or seascape scale ranges. A geomorphic discontinuity framework, expanded to include ecological patterns, provides a way to incorporate important but irregularly distributed physical features into organism–environment relationships. Here, we test if migratory striped bass (Morone saxatilis) are consistently concentrated by spatial discontinuities and why. We quantified the distribution of 50 acoustically tagged striped bass at 40 sites within Plum Island Estuary, Massachusetts during four-monthly surveys relative to four physical discontinuities (sandbar, confluence, channel network, drop-off), one continuous physical feature (depth variation), and a geographic location variable (region). Despite moving throughout the estuary, striped bass were consistently clustered in the middle geographic region at sites with high sandbar area, close to channel networks, adjacent to complex confluences, with intermediate levels of bottom unevenness, and medium sized drop-offs. In addition, the highest striped bass concentrations occurred at sites with the greatest additive physical heterogeneity (i.e., where multiple discontinuities co-occurred). The need to incorporate irregularly distributed features in organism–environment relationships will increase as high-quality telemetry and GIS data accumulate for mobile organisms. The spatially explicit approach we used to address this challenge can aid both researchers who seek to understand the impact of predators on ecosystems and resource managers who require new approaches for biological conservation.

Relativistic transport equation for a multiple discontinuity wave

Energy Technology Data Exchange (ETDEWEB)

Giambo, S [Istituto di Matematica, Universita degli Studi, Messina (Italy)

1980-09-29

The theory of singular hypersurfaces is combined with the ray theory to study propagation of weak discontinuities of solutions of a quasi-linear hyperbolic system in the context of special relativity. The case of a multiple wave is considered.

Critical issues of the structural integrity of the ITER-FEAT vacuum vessel

International Nuclear Information System (INIS)

Sannazzaro, G.; Barabaschi, P.; Elio, F.; Ioki, K.; Miki, N.; Onozuka, M.; Utin, Y.; Verrecchia, M.; Yoshimura, H.

2001-01-01

In the ITER-FEAT, the most severe loading conditions for the VV are the toroidal field coil fast discharge (TFCFD) and its load combination with electromagnetic loads due to a plasma vertical instability, which cause high compressive stresses in the VV inboard wall and increase the risk of buckling. Detailed analyses need to be performed to assess the stress level at the geometrical discontinuities and where concentrated loads are applied. The nuclear heating and the presence of gaps between the blanket modules cause concentrated nuclear heat loads. This paper describes the major structural issues of the ITER vacuum vessel (VV), and summarises the preliminary results of structural analyses

Critical issues of the structural integrity of the ITER-FEAT vacuum vessel

Energy Technology Data Exchange (ETDEWEB)

Sannazzaro, G. E-mail: sannazg@itereu.de; Barabaschi, P.; Elio, F.; Ioki, K.; Miki, N.; Onozuka, M.; Utin, Y.; Verrecchia, M.; Yoshimura, H

2001-11-01

In the ITER-FEAT, the most severe loading conditions for the VV are the toroidal field coil fast discharge (TFCFD) and its load combination with electromagnetic loads due to a plasma vertical instability, which cause high compressive stresses in the VV inboard wall and increase the risk of buckling. Detailed analyses need to be performed to assess the stress level at the geometrical discontinuities and where concentrated loads are applied. The nuclear heating and the presence of gaps between the blanket modules cause concentrated nuclear heat loads. This paper describes the major structural issues of the ITER vacuum vessel (VV), and summarises the preliminary results of structural analyses.

Factorization of products of discontinuous functions applied to Fourier-Bessel basis.

Science.gov (United States)

Popov, Evgeny; Nevière, Michel; Bonod, Nicolas

2004-01-01

The factorization rules of Li [J. Opt. Soc. Am. A 13, 1870 (1996)] are generalized to a cylindrical geometry requiring the use of a Bessel function basis. A theoretical study confirms the validity of the Laurent rule when a product of two continuous functions or of one continuous and one discontinuous function is factorized. The necessity of applying the so-called inverse rule in factorizing a continuous product of two discontinuous functions in a truncated basis is demonstrated theoretically and numerically.

Perceived discontinuities and continuities in transdisciplinary scientific working groups.

Science.gov (United States)

Crowston, Kevin; Specht, Alison; Hoover, Carol; Chudoba, Katherine M; Watson-Manheim, Mary Beth

2015-11-15

We examine the DataONE (Data Observation Network for Earth) project, a transdisciplinary organization tasked with creating a cyberinfrastructure platform to ensure preservation of and access to environmental science and biological science data. Its objective was a difficult one to achieve, requiring innovative solutions. The DataONE project used a working group structure to organize its members. We use organizational discontinuity theory as our lens to understand the factors associated with success in such projects. Based on quantitative and qualitative data collected from DataONE members, we offer recommendations for the use of working groups in transdisciplinary synthesis. Recommendations include welcome diverse opinions and world views, establish shared communication practices, schedule periodic synchronous face-to-face meetings, and ensure the active participation of bridge builders or knowledge brokers such as librarians who know how to ask questions about disciplines not their own. Copyright © 2015 Elsevier B.V. All rights reserved.

Mode conversions by a discontinuous junction of two helix loaded waveguides

International Nuclear Information System (INIS)

Choe, J.Y.; Ahn, S.; Ganquly, A.K.; Uhm, H.S.

1983-01-01

For various reasons, it is desirable to vary the primary propagating mode from one section of the waveguide to another. We choose the base structure to be the sheath helix loaded waveguide. Specifically, we join two physically different helix loaded waveguides axisymmetrically, thereby providing the required discontinuities at the junction (Z = 0). The helix loaded waveguide is more advantageous to the simple waveguide in that the helix mode that exists uniquely in the helix waveguide in addition to the usual fast wave hybrid modes, is without cutoff and thus behaves like a transmission line. In order to obtain the mode conversion rates, we expand the waves in the both sides of the junction with its own eigenmodes including the evanescent modes, and by matching fields at the junction (Z = 0) obtain the matrix equation for the coefficients for the eigenmodes in both sides. By choosing the propagating incident wave (Z = 0) the resulting outgoing waves in the other end (Z > 0) will be computed from the matrix equation. A computer program is devised to solve the suitably truncated matrix equation, and the numerical examples for the mode conversion rates with the parameter variations will be presented. The relevant physical parameters to yield discontinuities at the junction are the radii of the outer conductor and the helix wire and the pitch angle of the helix. Special emphases are on the conversion rates from the helix mode (Z 0) for the application to the tapered gyrotron amplifier

Characterization of discontinuities in high-dimensional stochastic problems on adaptive sparse grids

International Nuclear Information System (INIS)

Jakeman, John D.; Archibald, Richard; Xiu Dongbin

2011-01-01

In this paper we present a set of efficient algorithms for detection and identification of discontinuities in high dimensional space. The method is based on extension of polynomial annihilation for discontinuity detection in low dimensions. Compared to the earlier work, the present method poses significant improvements for high dimensional problems. The core of the algorithms relies on adaptive refinement of sparse grids. It is demonstrated that in the commonly encountered cases where a discontinuity resides on a small subset of the dimensions, the present method becomes 'optimal', in the sense that the total number of points required for function evaluations depends linearly on the dimensionality of the space. The details of the algorithms will be presented and various numerical examples are utilized to demonstrate the efficacy of the method.

Discontinuous Galerkin Approaches for Stokes Flow and Flow in Porous Media

Science.gov (United States)

Lehmann, Ragnar; Kaus, Boris; Lukacova, Maria

2014-05-01

Firstly, we present results of a study comparing two different numerical approaches for solving the Stokes equations with strongly varying viscosity: the continuous Galerkin (i.e., FEM) and the discontinuous Galerkin (DG) method. Secondly, we show how the latter method can be extended and applied to flow in porous media governed by Darcy's law. Nonlinearities in the viscosity or other material parameters can lead to discontinuities in the velocity-pressure solution that may not be approximated well with continuous elements. The DG method allows for discontinuities across interior edges of the underlying mesh. Furthermore, depending on the chosen basis functions, it naturally enforces local mass conservation, i.e., in every mesh cell. Computationally, it provides the capability to locally adapt the polynomial degree and needs communication only between directly adjacent mesh cells making it highly flexible and easy to parallelize. The methods are compared for several geophysically relevant benchmarking setups and discussed with respect to speed, accuracy, computational efficiency.

A case of new onset keratosis pilaris after discontinuation of erlotinib.

Science.gov (United States)

Okereke, Uchenna R; Colozza, Sara; Cohen, David E

2014-11-01

Keratosis pilaris and keratosis pilaris-like eruptions have been reported in association with RAF inhibitors sorafenib and vemurafenib. We describe herein what is to our knowledge the first reported case of new onset keratosis pilaris after discontinuation of EGFR inhibitor erlotinib. A 60 year-old female with stage IV lung cancer was treated with erlotinib (100 mg/d). The patient elected to discontinue erlotinib after four years secondary to adverse systemic reactions. However, five months later small, monomorphic, rough, folliculocentric papules with surrounding mild erythema characteristic of keratosis pilaris were noted on upper back and arms. This serves as the first documented case of new onset keratosis pilaris in a patient after discontinuation of erlotinib. We report the present case to show the possible association of keratosis pilaris with not only RAF inhibitors, but also the EGFR inhibitor erlotinib. Further investigation will determine whether this is a class effect with other systemic EGFR inhibitors.

Physicochemical properties of discontinuous S2-glass fiber reinforced resin composite.

Science.gov (United States)

Huang, Qiting; Qin, Wei; Garoushi, Sufyan; He, Jingwei; Lin, Zhengmei; Liu, Fang; Vallittu, Pekka K; Lassila, Lippo V J

2018-01-30

The objective of this study was to investigate several physicochemical properties of an experimental discontinuous S2-glass fiber-reinforced resin composite. The experimental composite was prepared by mixing 10 wt% of discontinuous S2-glass fibers with 27.5 wt% of resin matrix and 62.5 wt% of particulate fillers. Flexural strength (FS) and modulus (FM), fracture toughness (FT), work of fracture (WOF), double bond conversion (DC), Vickers hardness, volume shrinkage (VS) and fiber length distribution were determined. These were compared with two commercial resin composites. The experimental composite showed the highest FS, WOF and FT compared with two control composites. The DC of the experimental composite was comparable with controls. No significant difference was observed in VS between the three tested composites. The use of discontinuous glass fiber fillers with polymer matrix and particulate fillers yielded improved physical properties and substantial improvement was associated with the use of S2-glass fiber.

Recent Developments on Discontinuous Precipitation

Directory of Open Access Journals (Sweden)

Zięba P.

2017-06-01

Full Text Available The discontinuous precipitation (DP belongs to a group of diffusive solid state phase transformations during which the formation of a new phase is heterogeneous and limited to a migrating reaction front (RF. The use of analytical electron microscopy provided reliable information that there is no differences in the diffusion rate at the stationary grain boundary and moving RF of DP reaction. On the other hand, the use of “in situ” transmission electron microscopy observations indicated the importance of stop-go motion or oscillatory movement of the RF.

Kinetics of cardiac and vascular remodeling by spontaneously hypertensive rats after discontinuation of long-term captopril treatment

Directory of Open Access Journals (Sweden)

W.A. Rocha

2010-04-01

Full Text Available Angiotensin-converting enzyme inhibitors reduce blood pressure and attenuate cardiac and vascular remodeling in hypertension. However, the kinetics of remodeling after discontinuation of the long-term use of these drugs are unknown. Our objective was to investigate the temporal changes occurring in blood pressure and vascular structure of spontaneously hypertensive rats (SHR. Captopril treatment was started in the pre-hypertensive state. Rats (4 weeks were assigned to three groups: SHR-Cap (N = 51 treated with captopril (1 g/L in drinking water from the 4th to the 14th week; SHR-C (N = 48 untreated SHR; Wistar (N = 47 control rats. Subgroups of animals were studied at 2, 4, and 8 weeks after discontinuation of captopril. Direct blood pressure was recorded in freely moving animals after femoral artery catheterism. The animals were then killed to determine left ventricular hypertrophy (LVH and the aorta fixed at the same pressure measured in vivo. Captopril prevented hypertension (105 ± 3 vs 136 ± 5 mmHg, LVH (2.17 ± 0.05 vs 2.97 ± 0.14 mg/g body weight and the increase in cross-sectional area to luminal area ratio of the aorta (0.21 ± 0.01 vs 0.26 ± 0.02 μm² (SHR-Cap vs SHR-C. However, these parameters increased progressively after discontinuation of captopril (22nd week: 141 ± 2 mmHg, 2.50 ± 0.06 mg/g, 0.27 ± 0.02 μm². Prevention of the development of hypertension in SHR by using captopril during the prehypertensive period prevents the development of cardiac and vascular remodeling. Recovery of these processes follows the kinetic of hypertension development after discontinuation of captopril.

Applications of continuity and discontinuity of a fractional derivative of the wave functions to fractional quantum mechanics

International Nuclear Information System (INIS)

Dong Jianping; Xu Mingyu

2008-01-01

The space fractional Schroedinger equation with a finite square potential, periodic potential, and delta-function potential is studied in this paper. We find that the continuity or discontinuity condition of a fractional derivative of the wave functions should be considered to solve the fractional Schroedinger equation in fractional quantum mechanics. More parity states than those given by standard quantum mechanics for the finite square potential well are obtained. The corresponding energy equations are derived and then solved by graphical methods. We show the validity of Bloch's theorem and reveal the energy band structure for the periodic potential. The jump (discontinuity) condition for the fractional derivative of the wave function of the delta-function potential is given. With the help of the jump condition, we study some delta-function potential fields. For the delta-function potential well, an alternate expression of the wave function (the H function form of it was given by Dong and Xu [J. Math. Phys. 48, 072105 (2007)]) is obtained. The problems of a particle penetrating through a delta-function potential barrier and the fractional probability current density of the particle are also discussed. We study the Dirac comb and show the energy band structure at the end of the paper

Discontinuities in an axisymmetric generalized thermoelastic problem

Directory of Open Access Journals (Sweden)

Moncef Aouadi

2005-06-01

Full Text Available This paper deals with discontinuities analysis in the temperature, displacement, and stress fields of a thick plate whose lower and upper surfaces are traction-free and subjected to a given axisymmetric temperature distribution. The analysis is carried out under three thermoelastic theories. Potential functions together with Laplace and Hankel transform techniques are used to derive the solution in the transformed domain. Exact expressions for the magnitude of discontinuities are computed by using an exact method developed by Boley (1962. It is found that there exist two coupled waves, one of which is elastic and the other is thermal, both propagating with finite speeds with exponential attenuation, and a third which is called shear wave, propagating with constant speed but with no exponential attenuation. The Hankel transforms are inverted analytically. The inversion of the Laplace transforms is carried out using the inversion formula of the transform together with Fourier expansion techniques. Numerical results are presented graphically along with a comparison of the three theories of thermoelasticity.

Steady-state creep of discontinuous fibre composites

International Nuclear Information System (INIS)

Boecker Pedersen, O.

1975-07-01

A review is given of the relevant literature on creep of composites, including a presentation of existing models for the steady-state creep of composites containing aligned discontinuous fibres where creep of the matrix and fibres is assumed to follow a power law. A model is suggested for predicting the composite creep law from a matrix creep law given in a general form, in the case where the fibres do not creep. The composite creep law predicted by this model is compared with those predicted by previous models, when these are extended to comprise a general matrix creep law. Experimentally, pure copper and composites consisting of aligned discontinuous tungsten fibres in a copper matrix were creep tested at a temperature of 500 deg C. The results indicate a relatively low stress sensitivity of the steady-state creep-rate for pure copper and relatively high stress sensitivity for the composites. This may be explained by the creep models based upon a general matrix creep law. A quantitative prediction shows promising agreement with the present experimental results. (author)

Topology of the correlation networks among major currencies using hierarchical structure methods

Science.gov (United States)

Keskin, Mustafa; Deviren, Bayram; Kocakaplan, Yusuf

2011-02-01

We studied the topology of correlation networks among 34 major currencies using the concept of a minimal spanning tree and hierarchical tree for the full years of 2007-2008 when major economic turbulence occurred. We used the USD (US Dollar) and the TL (Turkish Lira) as numeraires in which the USD was the major currency and the TL was the minor currency. We derived a hierarchical organization and constructed minimal spanning trees (MSTs) and hierarchical trees (HTs) for the full years of 2007, 2008 and for the 2007-2008 period. We performed a technique to associate a value of reliability to the links of MSTs and HTs by using bootstrap replicas of data. We also used the average linkage cluster analysis for obtaining the hierarchical trees in the case of the TL as the numeraire. These trees are useful tools for understanding and detecting the global structure, taxonomy and hierarchy in financial data. We illustrated how the minimal spanning trees and their related hierarchical trees developed over a period of time. From these trees we identified different clusters of currencies according to their proximity and economic ties. The clustered structure of the currencies and the key currency in each cluster were obtained and we found that the clusters matched nicely with the geographical regions of corresponding countries in the world such as Asia or Europe. As expected the key currencies were generally those showing major economic activity.

Origin and structure of major orogen-scale exhumed strike-slip

Science.gov (United States)

Cao, Shuyun; Neubauer, Franz

2016-04-01

The formation of major exhumed strike-slip faults represents one of the most important dynamic processes affecting the evolution of the Earth's lithosphere and surface. Detailed models of the potential initiation and properties and architecture of orogen-scale exhumed strike-slip faults and how these relate to exhumation are rare. In this study, we deal with key properties controlling the development of major exhumed strike-slip fault systems, which are equivalent to the deep crustal sections of active across fault zones. We also propose two dominant processes for the initiation of orogen-scale exhumed strike-slip faults: (1) pluton-controlled and (2) metamorphic core complex-controlled strike-slip faults. In these tectonic settings, the initiation of faults occurs by rheological weakening along hot-to-cool contacts and guides the overall displacement and ultimate exhumation. These processes result in a specific thermal and structural architecture of such faults. These types of strike-slip dominated fault zones are often subparallel to mountain ranges and expose a wide variety of mylonitic, cataclastic and non-cohesive fault rocks, which were formed at different structural levels of the crust during various stages of faulting. The high variety of distinctive fault rocks is a potential evidence for recognition of these types of strike-slip faults. Exhumation of mylonitic rocks is, therefore, a common feature of such reverse oblique-slip strike-slip faults, implying major transtensive and/or transpressive processes accompanying pure strike-slip motion during exhumation. Some orogen-scale strike-slip faults nucleate and initiate along rheologically weak zones, e.g. at granite intrusions, zones of low-strength minerals, thermally weakened crust due to ascending fluids, and lateral borders of hot metamorphic core complexes. A further mechanism is the juxtaposition of mechanically strong mantle lithosphere to hot asthenosphere in continental transform faults (e.g., San

A new method for automatic discontinuity traces sampling on rock mass 3D model

Science.gov (United States)

Umili, G.; Ferrero, A.; Einstein, H. H.

2013-02-01

A new automatic method for discontinuity traces mapping and sampling on a rock mass digital model is described in this work. The implemented procedure allows one to automatically identify discontinuity traces on a Digital Surface Model: traces are detected directly as surface breaklines, by means of maximum and minimum principal curvature values of the vertices that constitute the model surface. Color influence and user errors, that usually characterize the trace mapping on images, are eliminated. Also trace sampling procedures based on circular windows and circular scanlines have been implemented: they are used to infer trace data and to calculate values of mean trace length, expected discontinuity diameter and intensity of rock discontinuities. The method is tested on a case study: results obtained applying the automatic procedure on the DSM of a rock face are compared to those obtained performing a manual sampling on the orthophotograph of the same rock face.

Discontinuous Galerkin finite element method with anisotropic local grid refinement for inviscid compressible flows

NARCIS (Netherlands)

van der Vegt, Jacobus J.W.; van der Ven, H.

1998-01-01

A new discretization method for the three-dimensional Euler equations of gas dynamics is presented, which is based on the discontinuous Galerkin finite element method. Special attention is paid to an efficient implementation of the discontinuous Galerkin method that minimizes the number of flux

A detailed map of the 660-kilometer discontinuity beneath the izu-bonin subduction zone.

Science.gov (United States)

Wicks, C W; Richards, M A

1993-09-10

Dynamical processes in the Earth's mantle, such as cold downwelling at subduction zones, cause deformations of the solid-state phase change that produces a seismic discontinuity near a depth of 660 kilometers. Observations of short-period, shear-to-compressional wave conversions produced at the discontinuity yield a detailed map of deformation beneath the Izu-Bonin subduction zone. The discontinuity is depressed by about 60 kilometers beneath the coldest part of the subducted slab, with a deformation profile consistent with the expected thermal signature of the slab, the experimentally determined Clapeyron slope of the phase transition, and the regional tectonic history.

Higher derivative discontinuous solutions to linear ordinary differential equations: a new route to complexity?

International Nuclear Information System (INIS)

Datta, Dhurjati Prasad; Bose, Manoj Kumar

2004-01-01

We present a new one parameter family of second derivative discontinuous solutions to the simplest scale invariant linear ordinary differential equation. We also point out how the construction could be extended to generate families of higher derivative discontinuous solutions as well. The discontinuity can occur only for a subset of even order derivatives, viz., 2nd, 4th, 8th, 16th,.... The solutions are shown to break the discrete parity (reflection) symmetry of the underlying equation. These results are expected to gain significance in the contemporary search of a new dynamical principle for understanding complex phenomena in nature

Strength Reduction Method for Stability Analysis of Local Discontinuous Rock Mass with Iterative Method of Partitioned Finite Element and Interface Boundary Element

Directory of Open Access Journals (Sweden)

Tongchun Li

2015-01-01

element is proposed to solve the safety factor of local discontinuous rock mass. Slope system is divided into several continuous bodies and local discontinuous interface boundaries. Each block is treated as a partition of the system and contacted by discontinuous joints. The displacements of blocks are chosen as basic variables and the rigid displacements in the centroid of blocks are chosen as motion variables. The contact forces on interface boundaries and the rigid displacements to the centroid of each body are chosen as mixed variables and solved iteratively using the interface boundary equations. Flexibility matrix is formed through PFE according to the contact states of nodal pairs and spring flexibility is used to reflect the influence of weak structural plane so that nonlinear iteration is only limited to the possible contact region. With cohesion and friction coefficient reduced gradually, the states of all nodal pairs at the open or slip state for the first time are regarded as failure criterion, which can decrease the effect of subjectivity in determining safety factor. Examples are used to verify the validity of the proposed method.

Nonlinear Displacement Discontinuity Model for Generalized Rayleigh Wave in Contact Interface

Energy Technology Data Exchange (ETDEWEB)

Kim, No Hyu; Yang, Seung Yong [Korea University of Technology and Education, Cheonan (Korea, Republic of)

2007-12-15

Imperfectly jointed interface serves as mechanical waveguide for elastic waves and gives rise to two distinct kinds of guided wave propagating along the interface. Contact acoustic nonlinearity (CAN) is known to plays major role in the generation of these interface waves called generalized Rayleigh waves in non-welded interface. Closed crack is modeled as non-welded interface that has nonlinear discontinuity condition in displacement across its boundary. Mathematical analysis of boundary conditions and wave equation is conducted to investigate the dispersive characteristics of the interface waves. Existence of the generalized Rayleigh wave(interface wave) in nonlinear contact interface is verified in theory where the dispersion equation for the interface wave is formulated and analyzed. It reveals that the interface waves have two distinct modes and that the phase velocity of anti-symmetric wave mode is highly dependent on contact conditions represented by linear and nonlinear dimensionless specific stiffness

Nonlinear Displacement Discontinuity Model for Generalized Rayleigh Wave in Contact Interface

International Nuclear Information System (INIS)

Kim, No Hyu; Yang, Seung Yong

2007-01-01

Imperfectly jointed interface serves as mechanical waveguide for elastic waves and gives rise to two distinct kinds of guided wave propagating along the interface. Contact acoustic nonlinearity (CAN) is known to plays major role in the generation of these interface waves called generalized Rayleigh waves in non-welded interface. Closed crack is modeled as non-welded interface that has nonlinear discontinuity condition in displacement across its boundary. Mathematical analysis of boundary conditions and wave equation is conducted to investigate the dispersive characteristics of the interface waves. Existence of the generalized Rayleigh wave(interface wave) in nonlinear contact interface is verified in theory where the dispersion equation for the interface wave is formulated and analyzed. It reveals that the interface waves have two distinct modes and that the phase velocity of anti-symmetric wave mode is highly dependent on contact conditions represented by linear and nonlinear dimensionless specific stiffness

Adaptive local basis set for Kohn–Sham density functional theory in a discontinuous Galerkin framework I: Total energy calculation

International Nuclear Information System (INIS)

Lin Lin; Lu Jianfeng; Ying Lexing; Weinan, E

2012-01-01

Kohn–Sham density functional theory is one of the most widely used electronic structure theories. In the pseudopotential framework, uniform discretization of the Kohn–Sham Hamiltonian generally results in a large number of basis functions per atom in order to resolve the rapid oscillations of the Kohn–Sham orbitals around the nuclei. Previous attempts to reduce the number of basis functions per atom include the usage of atomic orbitals and similar objects, but the atomic orbitals generally require fine tuning in order to reach high accuracy. We present a novel discretization scheme that adaptively and systematically builds the rapid oscillations of the Kohn–Sham orbitals around the nuclei as well as environmental effects into the basis functions. The resulting basis functions are localized in the real space, and are discontinuous in the global domain. The continuous Kohn–Sham orbitals and the electron density are evaluated from the discontinuous basis functions using the discontinuous Galerkin (DG) framework. Our method is implemented in parallel and the current implementation is able to handle systems with at least thousands of atoms. Numerical examples indicate that our method can reach very high accuracy (less than 1 meV) with a very small number (4–40) of basis functions per atom.

41 CFR 101-39.105-1 - Transfers from discontinued or curtailed fleet management systems.

Science.gov (United States)

2010-07-01

... discontinued or curtailed fleet management systems. 101-39.105-1 Section 101-39.105-1 Public Contracts and... AVIATION, TRANSPORTATION, AND MOTOR VEHICLES 39-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.1-Establishment, Modification, and Discontinuance of Interagency Fleet Management Systems § 101-39.105-1 Transfers from...

Interspecies radioimmunoassay for the major structural proteins of primate type-D retroviruses

International Nuclear Information System (INIS)

Colcher, D.; Teramoto, Y.A.; Schlom, J.

1977-01-01

A competition radioimmunoassay has been developed in which type-D retroviruses from three primate species compete. The assay utilizes the major structural protein (36,000 daltons) of the endogenous squirrel monkey retrovirus and antisera directed against the major structural protein (27,000 daltons) of the Mason-Pfizer monkey virus isolated from rhesus monkeys. Purified preparations of both viruses grown in heterologous cells, as well as extracts of heterologous cells infected with squirrel monkey retrovirus or Mason-Pfizer monkey virus, compete completely in the assay. Addition of an endogenous virus of the langur monkey also results in complete blocking. No blocking in the assay is observed with type-C baboon viruses, woolly monkey virus, and gibbon virus. Various other type-C and type-B viruses also showed no reactivity. An interspecies assay has thus been developed that recognizes the type-D retroviruses from both Old World monkey (rhesus and langur) and New World monkey (squirrel) species

Investigation of Soil and Vegetation Characteristics in Discontinuous Permafrost Landscapes Near Fairbanks, Alaska

Science.gov (United States)

2015-08-01

ER D C TR -1 5- 7 ERDC Center-Directed Research Investigation of Soil and Vegetation Characteristics in Discontinuous Permafrost ...Characteristics in Discontinuous Permafrost Landscapes Near Fairbanks, Alaska Jacob F. Berkowitz U.S. Army Engineer Research and Development Center (ERDC...Washington, DC 20314-1000 Under ERDC Center-Directed Research project “Integrated Technologies for Delineat- ing Permafrost and Ground-State

Magnetosheath Propagation Time of Solar Wind Directional Discontinuities

Science.gov (United States)

Samsonov, A. A.; Sibeck, D. G.; Dmitrieva, N. P.; Semenov, V. S.; Slivka, K. Yu.; Å afránkova, J.; Němeček, Z.

2018-05-01

Observed delays in the ground response to solar wind directional discontinuities have been explained as the result of larger than expected magnetosheath propagation times. Recently, Samsonov et al. (2017, https://doi.org/10.1002/2017GL075020) showed that the typical time for a southward interplanetary magnetic field (IMF) turning to propagate across the magnetosheath is 14 min. Here by using a combination of magnetohydrodynamic simulations, spacecraft observations, and analytic calculations, we study the dependence of the propagation time on solar wind parameters and near-magnetopause cutoff speed. Increases in the solar wind speed result in greater magnetosheath plasma flow velocities, decreases in the magnetosheath thickness and, as a result, decreases in the propagation time. Increases in the IMF strength result in increases in the magnetosheath thickness and increases in the propagation time. Both magnetohydrodynamic simulations and observations suggest that propagation times are slightly smaller for northward IMF turnings. Magnetosheath flow deceleration must be taken into account when predicting the arrival times of solar wind structures at the dayside magnetopause.

Closed-Form Solutions for Gradient Elastic Beams with Geometric Discontinuities by Laplace Transform

Directory of Open Access Journals (Sweden)

Mustafa Özgür Yayli

2013-01-01

Full Text Available The static bending solution of a gradient elastic beam with external discontinuities is presented by Laplace transform. Its utility lies in the ability to switch differential equations to algebraic forms that are more easily solved. A Laplace transformation is applied to the governing equation which is then solved for the static deflection of the microbeam. The exact static response of the gradient elastic beam with external discontinuities is obtained by applying known initial conditions when the others are derived from boundary conditions. The results are given in a series of figures and compared with their classical counterparts. The main contribution of this paper is to provide a closed-form solution for the static deflection of microbeams under geometric discontinuities.

A two-site mean field model of discontinuous dynamic recrystallization

International Nuclear Information System (INIS)

Bernard, P.; Bag, S.; Huang, K.; Loge, R.E.

2011-01-01

Highlights: → Discontinuous dynamic recrystallization (DDRX) is modelled at the grain scale. → The two-site mean field approach allows introducing topological information. → DDRX kinetics, flow stress curves and recrystallized grain size are well predicted. → Temperature, strain rate and initial grain size effects are successfully described. → Grain size dependence naturally emerges from the model and agrees with experiment. - Abstract: The paper describes a new model of discontinuous dynamic recrystallization (DDRX) which can operate in constant or variable thermomechanical conditions. The model considers the elementary physical phenomena at the grain scale such as strain hardening, recovery, grain boundary migration, and nucleation. The microstructure is represented through a set of representative grains defined by their size and dislocation density. It is linked to a constitutive law giving access to the polycrystal flow stress. Interaction between representative grains and the surrounding material is idealized using a two-site approach whereby two homogeneous equivalent media with different dislocation densities are considered. Topological information is incorporated into the model by prescribing the relative weight of these two equivalent media as a function of their volume fractions. This procedure allows accounting for the well-known necklace structures. The model is applied to the prediction of DDRX in 304 L stainless steel, with parameters identified using an inverse methodology based on a genetic algorithm. Results show good agreement with experimental data at different temperatures and strain rates, predicting recrystallization kinetics, recrystallized grain size and stress-strain curve. Parameters identified with one initial grain size lead to accurate results for another initial grain size without introducing any additional parameter.

Discontinuities in ODEs - Systems with change of state

DEFF Research Database (Denmark)

Thomsen, Per Grove

2006-01-01

The occurrence of discontinuous right hand sides in ODE-systems often appears in technical applications. Such applications may be characterised by the cases where the system changes between several states. Each state is defined by a system of ODEs and the transition between states is defined...

State and data techniques for control of discontinuous systems

International Nuclear Information System (INIS)

Kisner, R.A.

1986-01-01

The need for automated control systems becomes clear as the complexity of nuclear power plants increases and economic incentives demand higher plant availability. A control system with intelligence distributed throughout its controllers allows reduction in operator workload, perhaps reduction in crew size, and potentially a reduction in on-line human error. In automated systems of this kind, each controller should be capable of making decisions and carrying out a plan of action. This paper describes a technique for structured analysis and design of automated control systems. The technique integrates control of continuous and discontinuous nuclear power plant subsystems and components. A hierarchical control system with distributed intelligence follows from applying the technique. Further, it can be applied to all phases of control system design. For simplicity, the example used in the paper is limited to phase I design (basic automatic control action), in which no maintenance, testing, or contingency capability is attempted

Rock discontinuity surface roughness variation with scale

Science.gov (United States)

Bitenc, Maja; Kieffer, D. Scott; Khoshelham, Kourosh

2017-04-01

ABSTRACT: Rock discontinuity surface roughness refers to local departures of the discontinuity surface from planarity and is an important factor influencing the shear resistance. In practice, the Joint Roughness Coefficient (JRC) roughness parameter is commonly relied upon and input to a shear strength criterion such as developed by Barton and Choubey [1977]. The estimation of roughness by JRC is hindered firstly by the subjective nature of visually comparing the joint profile to the ten standard profiles. Secondly, when correlating the standard JRC values and other objective measures of roughness, the roughness idealization is limited to a 2D profile of 10 cm length. With the advance of measuring technologies that provide accurate and high resolution 3D data of surface topography on different scales, new 3D roughness parameters have been developed. A desirable parameter is one that describes rock surface geometry as well as the direction and scale dependency of roughness. In this research a 3D roughness parameter developed by Grasselli [2001] and adapted by Tatone and Grasselli [2009] is adopted. It characterizes surface topography as the cumulative distribution of local apparent inclination of asperities with respect to the shear strength (analysis) direction. Thus, the 3D roughness parameter describes the roughness amplitude and anisotropy (direction dependency), but does not capture the scale properties. In different studies the roughness scale-dependency has been attributed to data resolution or size of the surface joint (see a summary of researches in [Tatone and Grasselli, 2012]). Clearly, the lower resolution results in lower roughness. On the other hand, have the investigations of surface size effect produced conflicting results. While some studies have shown a decrease in roughness with increasing discontinuity size (negative scale effect), others have shown the existence of positive scale effects, or both positive and negative scale effects. We

A new method for automated discontinuity trace mapping on rock mass 3D surface model

Science.gov (United States)

Li, Xiaojun; Chen, Jianqin; Zhu, Hehua

2016-04-01

This paper presents an automated discontinuity trace mapping method on a 3D surface model of rock mass. Feature points of discontinuity traces are first detected using the Normal Tensor Voting Theory, which is robust to noisy point cloud data. Discontinuity traces are then extracted from feature points in four steps: (1) trace feature point grouping, (2) trace segment growth, (3) trace segment connection, and (4) redundant trace segment removal. A sensitivity analysis is conducted to identify optimal values for the parameters used in the proposed method. The optimal triangular mesh element size is between 5 cm and 6 cm; the angle threshold in the trace segment growth step is between 70° and 90°; the angle threshold in the trace segment connection step is between 50° and 70°, and the distance threshold should be at least 15 times the mean triangular mesh element size. The method is applied to the excavation face trace mapping of a drill-and-blast tunnel. The results show that the proposed discontinuity trace mapping method is fast and effective and could be used as a supplement to traditional direct measurement of discontinuity traces.

Prognostic significance of delayed structural recovery after macular hole surgery

DEFF Research Database (Denmark)

Christensen, Ulrik C; Krøyer, Kristian; Sander, Birgit

2009-01-01

was used; however, secondary macular hole surgery had a significant influence on diameter of photoreceptor layer discontinuity at 3 months. CONCLUSIONS: Structural recovery in the form of photoreceptor layer discontinuity with a diameter of more than approximately 1500 microm 3 months after macular hole...

Reasons for Electronic Cigarette Experimentation and Discontinuation Among Adolescents and Young Adults.

Science.gov (United States)

Kong, Grace; Morean, Meghan E; Cavallo, Dana A; Camenga, Deepa R; Krishnan-Sarin, Suchitra

2015-07-01

Understanding why young people try and stop electronic cigarette (e-cigarette) use is critical to inform e-cigarette regulatory efforts. We conducted 18 focus groups (N = 127) in 1 middle school (MS), 2 high schools (HSs), and 2 colleges in Connecticut to assess themes related to e-cigarette experimentation and discontinuation. We then conducted surveys to evaluate these identified themes in 2 MSs, 4 HSs, and 1 college (N = 1,175) to explore whether reasons for e-cigarette experimentation and/or discontinuation differed by school level or cigarette smoking status. From the focus groups, we identified experimentation themes (i.e., curiosity, flavors, family/peer influence, easy access, and perceptions of e-cigarettes as "cool" and as a healthier/better alternative to cigarettes) and discontinuation themes (i.e., health concerns, loss of interest, high cost, bad taste, and view of e-cigarettes as less satisfying than cigarettes). The survey data showed that the top reasons for experimentation were curiosity (54.4%), appealing flavors (43.8%), and peer influences (31.6%), and the top reasons for discontinuation were responses related to losing interest (23.6%), perceiving e-cigarettes as "uncool" (16.3%), and health concerns (12.1%). Cigarette smokers tried e-cigarettes because of the perceptions that they can be used anywhere and to quit smoking and discontinued because they were not as satisfying as cigarettes. School level differences were detected. E-cigarette prevention efforts toward youth should include limiting e-cigarette flavors, communicating messages emphasizing the health risks of use, and changing social norms surrounding the use of e-cigarettes. The results should be interpreted in light of the limitations of this study. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Abrupt opium discontinuation has no significant triggering effect on acute myocardial infarction.

Science.gov (United States)

Masoomi, Mohammad; Zare, Jahangir; Nasri, Hamidreza; Mirzazadeh, Ali; Sheikhvatan, Mehrdad

2011-04-01

A deleterious effect of withdrawal symptoms due to abrupt discontinuation of opium on the cardiovascular system is one of the recent interesting topics in the cardiovascular field. The current study hypothesized that the withdrawal syndrome due to discontinuing opium might be an important trigger for the appearance of acute myocardial infarction. Eighty-one opium-addicted individuals who were candidates for cardiovascular clinical evaluation and consecutively hospitalized in the coronary care unit (CCU) ward of Shafa Hospital in Kerman between January and July 2009 were included in the study and categorized in the case group, including patients experiencing withdrawal symptoms within 6-12 h after the reduced or discontinued use of opium according to the Diagnostic and Statistical Manual of Mental Disorders-revised IV version (DSM-IV-R) criteria for opium dependence and withdrawal, and the control group, without opium withdrawal symptoms. The appearance of acute myocardial infarction was compared between the two groups using multivariable regression models. Acute myocardial infarction occurred in 50.0% of those with withdrawal symptoms and in 45.1% of patients without evidence of opium withdrawal (P = 0.669). Multivariable analysis showed that opium withdrawal symptoms were not a trigger for acute myocardial infarction adjusting for demographic characteristics, marital status, education level and common coronary artery disease risk profiles [odds ratio (OR) = 0.920, 95% confidence interval (CI) = 0.350-2.419, P = 0.866]. Also, daily dose of opium before reducing or discontinuing use did not predict the appearance of myocardial infarction in the presence of confounder variables (OR = 0.975, 95% CI = 0.832-1.143, P = 0.755). Withdrawal syndrome due to abrupt discontinuation of opium does not have a triggering role for appearance of acute myocardial infarction.

Stable and high order accurate difference methods for the elastic wave equation in discontinuous media

KAUST Repository

Duru, Kenneth; Virta, Kristoffer

2014-01-01

to be discontinuous. The key feature is the highly accurate and provably stable treatment of interfaces where media discontinuities arise. We discretize in space using high order accurate finite difference schemes that satisfy the summation by parts rule. Conditions

Utilization and discontinuation of contraceptive methods: the University of Calabar Teaching Hospital (UCTH experience

Directory of Open Access Journals (Sweden)

Njoku CO

2014-09-01

Full Text Available Background: Contraception has an important role to play in reducing the high rate of maternal morbidity and mortality in developing countries. Objective: The objective is to determine the prevalence rate, methods and reasons for discontinuation of contraceptive methods at UCTH, Calabar. Method: This was a retrospective study of all clients that utilised different forms of contraceptives at UCTH, Calabar from 1st January, 2009 to 31st December, 2013. Results: A total of 5,381 clients used various methods of contraception while 13,492 live births were recorded giving the prevalence rate of 39.9% of total live birth. Common methods were intrauterine contraceptive device (IUCD 1,745(32.8% and injectable contraceptives 1,268(23.8%. Most clients 1,876(35.2% were graduates while 81(1.5% had no formal education. A total of 535(10.1% clients discontinued different family planning method commonly due to desire for pregnancy and side effects. IUCD had the highest discontinuation rate. Conclusion: The study revealed low prevalence rate of contraceptive use which was more among teenagers and illiterate women. The main reasons for discontinuation of different methods were desire for pregnancy, side effects and menopause. Creating more contraceptive awareness, improvement in contraceptive counselling and female education will help to improve contraceptive utilisation rate and reduce discontinuation rate.

Surface electronic properties of discontinuous Pd films during hydrogen exposure

International Nuclear Information System (INIS)

Zhao, Ming; Nagata, Shinji; Shikama, Tatsuo; Inouye, Aichi; Yamamoto, Shunya; Yoshikawa, Masahito

2011-01-01

This paper explored the change in the surface resistance of the discontinuous palladium (Pd) films during hydrogen exposure. In our experiments, we observed a remarkable rise in the electrical resistance of the discontinuous film which consists of nano-sized particles, when it was exposed to thin hydrogen. By studying the resistance change ratio before and after hydrogen exposure, we have found that it demonstrates an inverse exponential relationship with the ratio of on-film particle radius to the inter island separation. This suggests that the change in the film resistance under hydrogen exposure is primarily associated with the variation of surface work function which is caused by the hydrogen absorption on the Pd surface. (author)

A Gas-kinetic Discontinuous Galerkin Method for Viscous Flow Equations

International Nuclear Information System (INIS)

Liu, Hongwei; Xu, Kun

2007-01-01

This paper presents a Runge-Kutta discontinuous Galerkin (RKDG) method for viscous flow computation. The construction of the RKDG method is based on a gas-kinetic formulation, which not only couples the convective and dissipative terms together, but also includes both discontinuous and continuous representation in the flux evaluation at the cell interface through a simple hybrid gas distribution function. Due to the intrinsic connection between the gaskinetic BGK model and the Navier-Stokes equations, the Navier-Stokes flux is automatically obtained by the present method. Numerical examples for both one dimensional (10) and two dimensional(20) compressible viscous flows are presented to demonstrate the accuracy and shock capturing capability of the current RKDG method

From continuous to discontinuous transitions in social diffusion

Science.gov (United States)

Tuzón, Paula; Fernández-Gracia, Juan; Eguíluz, Víctor M.

2018-03-01

Models of social diffusion reflect processes of how new products, ideas or behaviors are adopted in a population. These models typically lead to a continuous or a discontinuous phase transition of the number of adopters as a function of a control parameter. We explore a simple model of social adoption where the agents can be in two states, either adopters or non-adopters, and can switch between these two states interacting with other agents through a network. The probability of an agent to switch from non-adopter to adopter depends on the number of adopters in her network neighborhood, the adoption threshold T and the adoption coefficient a, two parameters defining a Hill function. In contrast the transition from adopter to non-adopter is spontaneous at a certain rate μ. In a mean-field approach, we derive the governing ordinary differential equations and show that the nature of the transition between the global non-adoption and global adoption regimes depends mostly on the balance between the probability to adopt with one and two adopters. The transition changes from continuous, via a transcritical bifurcation, to discontinuous, via a combination of a saddle-node and a transcritical bifurcation, through a supercritical pitchfork bifurcation. We characterize the full parameter space. Finally, we compare our analytical results with Montecarlo simulations on annealed and quenched degree regular networks, showing a better agreement for the annealed case. Our results show how a simple model is able to capture two seemingly very different types of transitions, i.e., continuous and discontinuous and thus unifies underlying dynamics for different systems. Furthermore the form of the adoption probability used here is based on empirical measurements.

Multi-centre diagnostic classification of individual structural neuroimaging scans from patients with major depressive disorder.

Science.gov (United States)

Mwangi, Benson; Ebmeier, Klaus P; Matthews, Keith; Steele, J Douglas

2012-05-01

Quantitative abnormalities of brain structure in patients with major depressive disorder have been reported at a group level for decades. However, these structural differences appear subtle in comparison with conventional radiologically defined abnormalities, with considerable inter-subject variability. Consequently, it has not been possible to readily identify scans from patients with major depressive disorder at an individual level. Recently, machine learning techniques such as relevance vector machines and support vector machines have been applied to predictive classification of individual scans with variable success. Here we describe a novel hybrid method, which combines machine learning with feature selection and characterization, with the latter aimed at maximizing the accuracy of machine learning prediction. The method was tested using a multi-centre dataset of T(1)-weighted 'structural' scans. A total of 62 patients with major depressive disorder and matched controls were recruited from referred secondary care clinical populations in Aberdeen and Edinburgh, UK. The generalization ability and predictive accuracy of the classifiers was tested using data left out of the training process. High prediction accuracy was achieved (~90%). While feature selection was important for maximizing high predictive accuracy with machine learning, feature characterization contributed only a modest improvement to relevance vector machine-based prediction (~5%). Notably, while the only information provided for training the classifiers was T(1)-weighted scans plus a categorical label (major depressive disorder versus controls), both relevance vector machine and support vector machine 'weighting factors' (used for making predictions) correlated strongly with subjective ratings of illness severity. These results indicate that machine learning techniques have the potential to inform clinical practice and research, as they can make accurate predictions about brain scan data from

Diffusion piecewise homogenization via flux discontinuity ratios

International Nuclear Information System (INIS)

Sanchez, Richard; Dante, Giorgio; Zmijarevic, Igor

2013-01-01

We analyze piecewise homogenization with flux-weighted cross sections and preservation of averaged currents at the boundary of the homogenized domain. Introduction of a set of flux discontinuity ratios (FDR) that preserve reference interface currents leads to preservation of averaged region reaction rates and fluxes. We consider the class of numerical discretizations with one degree of freedom per volume and per surface and prove that when the homogenization and computing meshes are equal there is a unique solution for the FDRs which exactly preserve interface currents. For diffusion sub-meshing we introduce a Jacobian-Free Newton-Krylov method and for all cases considered obtain an 'exact' numerical solution (eight digits for the interface currents). The homogenization is completed by extending the familiar full assembly homogenization via flux discontinuity factors to the sides of regions laying on the boundary of the piecewise homogenized domain. Finally, for the familiar nodal discretization we numerically find that the FDRs obtained with no sub-mesh (nearly at no cost) can be effectively used for whole-core diffusion calculations with sub-mesh. This is not the case, however, for cell-centered finite differences. (authors)

Reasons for Discontinuation of Implanon among Users in Buffalo ...

African Journals Online (AJOL)

USER

African Journal of Reproductive Health March 2018; 22(1):113 ... other medical treatments: 24 participants on the anti-retroviral drugs, one on antipsychotic and anti- ... The side effects of implanon were the reason for early discontinuation of.

Prevalence and associated factors of contraceptive discontinuation and switching among Bangladeshi married women of reproductive age

Directory of Open Access Journals (Sweden)

Mahumud RA

2015-01-01

Full Text Available Rashidul Alam Mahumud,1 Md Golam Hossain,2 Abdur Razzaque Sarkar,1 Md Nurul Islam,2 Md Ripter Hossain,2 Aik Saw,3 Jahangir AM Khan1,4 1Health Economics and Financing Research Group, Center for Equity and Health Systems, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh; 2Department of Statistics, University of Rajshahi, Rajshahi, Bangladesh; 3Department of Orthopaedic Surgery, National Orthopaedic Centre of Excellence for Research and Learning, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia; 4Adjunct Faculty, Health Economics Unit, Department of Learning, Informatics, Management and Ethics, Karolinska Institutet, Stockholm, Sweden Introduction: Contraceptive discontinuation is a worldwide incident that may be connected with low incentive to avoid pregnancy. Contraceptive discontinuation highly contributes to unplanned pregnancy and unwanted births.Objectives: The objective of this study was to observe the prevalence of discontinuation and switching of contraceptive methods among Bangladeshi married women. In addition, the sociodemographic factors associated with contraceptive discontinuation and switching were assessed.Methods: Secondary cross-sectional data was used in this study. A total of 16,273 married Bangladeshi women of reproductive age (15–49 years were considered in the present study, from the Bangladesh Demographic and Health Survey, 2011. Logistic regression models were used to determine the relationships between key sociodemographic factors and user status.Results: The prevalence of discontinuation and switching of contraceptive method among women were 38.4% and 15.4%, respectively. The logistic regression model demonstrated that women in early reproductive years (25–29 years and 30–34 years significantly more often (odds ratio [OR] =0.84 and 0.71, respectively discontinued use of contraceptives. Significantly higher rates of discontinuation were pronounced among women who

An H1(Ph)-Coercive Discontinuous Galerkin Formulation for the Poisson Problem : 1-D Analysis

NARCIS (Netherlands)

Van der Zee, K.G.; Van Brummelen, E.H.

2005-01-01

Discontinuous Galerkin (DG) methods are finite element techniques for the solution of partial differential equations. They allow shape functions which are discontinuous across inter-element edges. In principle, DG methods are ideally suited for hp-adaptivity, as they handle nonconforming meshes and

Second order finite volume scheme for Maxwell's equations with discontinuous electromagnetic properties on unstructured meshes

Energy Technology Data Exchange (ETDEWEB)

Ismagilov, Timur Z., E-mail: ismagilov@academ.org

2015-02-01

This paper presents a second order finite volume scheme for numerical solution of Maxwell's equations with discontinuous dielectric permittivity and magnetic permeability on unstructured meshes. The scheme is based on Godunov scheme and employs approaches of Van Leer and Lax–Wendroff to increase the order of approximation. To keep the second order of approximation near dielectric permittivity and magnetic permeability discontinuities a novel technique for gradient calculation and limitation is applied near discontinuities. Results of test computations for problems with linear and curvilinear discontinuities confirm second order of approximation. The scheme was applied to modelling propagation of electromagnetic waves inside photonic crystal waveguides with a bend.

Clinician support and psychosocial risk factors associated with breastfeeding discontinuation.

Science.gov (United States)

Taveras, Elsie M; Capra, Angela M; Braveman, Paula A; Jensvold, Nancy G; Escobar, Gabriel J; Lieu, Tracy A

2003-07-01

Breastfeeding rates fall short of goals set in Healthy People 2010 and other national recommendations. The current, national breastfeeding continuation rate of 29% at 6 months lags behind the Healthy People 2010 goal of 50%. The objective of this study was to evaluate associations between breastfeeding discontinuation at 2 and 12 weeks postpartum and clinician support, maternal physical and mental health status, workplace issues, and other factors amenable to intervention. A prospective cohort study was conducted of low-risk mothers and infants who were in a health maintenance organization and enrolled in a randomized, controlled trial of home visits. Mothers were interviewed in person at 1 to 2 days postpartum and by telephone at 2 and 12 weeks. Logistic regression modeling was performed to assess the independent effects of the predictors of interest, adjusting for sociodemographic and other confounding variables. Of the 1163 mother-newborn pairs in the cohort, 1007 (87%) initiated breastfeeding, 872 (75%) were breastfeeding at the 2-week interview, and 646 (55%) were breastfeeding at the 12-week interview. In the final multivariate models, breastfeeding discontinuation at 2 weeks was associated with lack of confidence in ability to breastfeed at the 1- to 2-day interview (odds ratio [OR]: 2.8; 95% confidence interval [CI]: 1.02-7.6), early breastfeeding problems (OR: 1.5; 95% CI: 1.1-1.97), Asian race/ethnicity (OR: 2.6; 95% CI: 1.1-5.7), and lower maternal education (OR: 1.5; 95% CI: 1.2-1.9). Mothers were much less likely to discontinue breastfeeding at 12 weeks postpartum if they reported (during the 12-week interview) having received encouragement from their clinician to breastfeed (OR: 0.6; 95% CI: 0.4-0.8). Breastfeeding discontinuation at 12 weeks was also associated with demographic factors and maternal depressive symptoms (OR: 1.18; 95% CI: 1.01-1.37) and returning to work or school by 12 weeks postpartum (OR: 2.4; 95% CI: 1.8-3.3). Our results indicate

Identification of a Discontinuous Parameter in Stochastic Parabolic Systems

International Nuclear Information System (INIS)

Aihara, S. I.

1998-01-01

The purpose of this paper is to study the identification problem for a spatially varying discontinuous parameter in stochastic diffusion equations. The consistency property of the maximum likelihood estimate (M.L.E.) and a generating algorithm for M.L.E. have been explored under the condition that the unknown parameter is in a sufficiently regular space with respect to spatial variables. In order to prove the consistency property of the M.L.E. for a discontinuous diffusion coefficient, we use the method of sieves, i.e., first the admissible class of unknown parameters is projected into a finite-dimensional space and next the convergence of the derived finite-dimensional M.L.E. to the infinite-dimensional M.L.E. is justified under some conditions. An iterative algorithm for generating the M.L.E. is also proposed with two numerical examples

Magnetic field integral equation analysis of surface plasmon scattering by rectangular dielectric channel discontinuities.

Science.gov (United States)

Chremmos, Ioannis

2010-01-01

The scattering of a surface plasmon polariton (SPP) by a rectangular dielectric channel discontinuity is analyzed through a rigorous magnetic field integral equation method. The scattering phenomenon is formulated by means of the magnetic-type scalar integral equation, which is subsequently treated through an entire-domain Galerkin method of moments (MoM), based on a Fourier-series plane wave expansion of the magnetic field inside the discontinuity. The use of Green's function Fourier transform allows all integrations over the area and along the boundary of the discontinuity to be performed analytically, resulting in a MoM matrix with entries that are expressed as spectral integrals of closed-form expressions. Complex analysis techniques, such as Cauchy's residue theorem and the saddle-point method, are applied to obtain the amplitudes of the transmitted and reflected SPP modes and the radiated field pattern. Through numerical results, we examine the wavelength selectivity of transmission and reflection against the channel dimensions as well as the sensitivity to changes in the refractive index of the discontinuity, which is useful for sensing applications.

Solution of the Neutron transport equation in hexagonal geometry using strongly discontinuous nodal schemes

International Nuclear Information System (INIS)

Mugica R, C.A.; Valle G, E. del

2005-01-01

In 2002, E. del Valle and Ernest H. Mund developed a technique to solve numerically the Neutron transport equations in discrete ordinates and hexagonal geometry using two nodal schemes type finite element weakly discontinuous denominated WD 5,3 and WD 12,8 (of their initials in english Weakly Discontinuous). The technique consists on representing each hexagon in the union of three rhombuses each one of which it is transformed in a square in the one that the methods WD 5,3 and WD 12,8 were applied. In this work they are solved the mentioned equations of transport using the same discretization technique by hexagon but using two nodal schemes type finite element strongly discontinuous denominated SD 3 and SD 8 (of their initials in english Strongly Discontinuous). The application in each case as well as a reference problem for those that results are provided for the effective multiplication factor is described. It is carried out a comparison with the obtained results by del Valle and Mund for different discretization meshes so much angular as spatial. (Author)

Bohman-Frieze-Wormald model on the lattice, yielding a discontinuous percolation transition

Science.gov (United States)

Schrenk, K. J.; Felder, A.; Deflorin, S.; Araújo, N. A. M.; D'Souza, R. M.; Herrmann, H. J.

2012-03-01

The BFW model introduced by Bohman, Frieze, and Wormald [Random Struct. Algorithms1042-983210.1002/rsa.20038, 25, 432 (2004)], and recently investigated in the framework of discontinuous percolation by Chen and D'Souza [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.106.115701 106, 115701 (2011)], is studied on the square and simple-cubic lattices. In two and three dimensions, we find numerical evidence for a strongly discontinuous transition. In two dimensions, the clusters at the threshold are compact with a fractal surface of fractal dimension df=1.49±0.02. On the simple-cubic lattice, distinct jumps in the size of the largest cluster are observed. We proceed to analyze the tree-like version of the model, where only merging bonds are sampled, for dimension two to seven. The transition is again discontinuous in any considered dimension. Finally, the dependence of the cluster-size distribution at the threshold on the spatial dimension is also investigated.

Adaptive mixed-hybrid and penalty discontinuous Galerkin method for two-phase flow in heterogeneous media

KAUST Repository

Hou, Jiangyong

2016-02-05

In this paper, we present a hybrid method, which consists of a mixed-hybrid finite element method and a penalty discontinuous Galerkin method, for the approximation of a fractional flow formulation of a two-phase flow problem in heterogeneous media with discontinuous capillary pressure. The fractional flow formulation is comprised of a wetting phase pressure equation and a wetting phase saturation equation which are coupled through a total velocity and the saturation affected coefficients. For the wetting phase pressure equation, the continuous mixed-hybrid finite element method space can be utilized due to a fundamental property that the wetting phase pressure is continuous. While it can reduce the computational cost by using less degrees of freedom and avoiding the post-processing of velocity reconstruction, this method can also keep several good properties of the discontinuous Galerkin method, which are important to the fractional flow formulation, such as the local mass balance, continuous normal flux and capability of handling the discontinuous capillary pressure. For the wetting phase saturation equation, the penalty discontinuous Galerkin method is utilized due to its capability of handling the discontinuous jump of the wetting phase saturation. Furthermore, an adaptive algorithm for the hybrid method together with the centroidal Voronoi Delaunay triangulation technique is proposed. Five numerical examples are presented to illustrate the features of proposed numerical method, such as the optimal convergence order, the accurate and efficient velocity approximation, and the applicability to the simulation of water flooding in oil field and the oil-trapping or barrier effect phenomena.

Adaptive mixed-hybrid and penalty discontinuous Galerkin method for two-phase flow in heterogeneous media

KAUST Repository

Hou, Jiangyong; Chen, Jie; Sun, Shuyu; Chen, Zhangxin

2016-01-01

In this paper, we present a hybrid method, which consists of a mixed-hybrid finite element method and a penalty discontinuous Galerkin method, for the approximation of a fractional flow formulation of a two-phase flow problem in heterogeneous media with discontinuous capillary pressure. The fractional flow formulation is comprised of a wetting phase pressure equation and a wetting phase saturation equation which are coupled through a total velocity and the saturation affected coefficients. For the wetting phase pressure equation, the continuous mixed-hybrid finite element method space can be utilized due to a fundamental property that the wetting phase pressure is continuous. While it can reduce the computational cost by using less degrees of freedom and avoiding the post-processing of velocity reconstruction, this method can also keep several good properties of the discontinuous Galerkin method, which are important to the fractional flow formulation, such as the local mass balance, continuous normal flux and capability of handling the discontinuous capillary pressure. For the wetting phase saturation equation, the penalty discontinuous Galerkin method is utilized due to its capability of handling the discontinuous jump of the wetting phase saturation. Furthermore, an adaptive algorithm for the hybrid method together with the centroidal Voronoi Delaunay triangulation technique is proposed. Five numerical examples are presented to illustrate the features of proposed numerical method, such as the optimal convergence order, the accurate and efficient velocity approximation, and the applicability to the simulation of water flooding in oil field and the oil-trapping or barrier effect phenomena.

Polymorphism of fibrillar structures depending on the size of assembled Aβ17-42 peptides

Science.gov (United States)

Cheon, Mookyung; Kang, Mooseok; Chang, Iksoo

2016-01-01

The size of assembled Aβ17-42 peptides can determine polymorphism during oligomerization and fibrillization, but the mechanism of this effect is unknown. Starting from separate random monomers, various fibrillar oligomers with distinct structural characteristics were identified using discontinuous molecular dynamics simulations based on a coarse-grained protein model. From the structures observed in the simulations, two characteristic oligomer sizes emerged, trimer and paranuclei, which generated distinct structural patterns during fibrillization. A majority of the simulations for trimers and tetramers formed non-fibrillar oligomers, which primarily progress to off-pathway oligomers. Pentamers and hexamers were significantly converted into U-shape fibrillar structures, meaning that these oligomers, called paranuclei, might be potent on-pathway intermediates in fibril formation. Fibrillar oligomers larger than hexamers generated substantial polymorphism in which hybrid structures were readily formed and homogeneous fibrillar structures appeared infrequently. PMID:27901087

Discontinuity relations for the AdS{sub 4}/CFT{sub 3} correspondence

Energy Technology Data Exchange (ETDEWEB)

Cavaglià, Andrea, E-mail: Cavaglia@to.infn.it [Centre for Mathematical Science, City University London, Northampton Square, London EC1V 0HB (United Kingdom); Dipartimento di Fisica and INFN, Università di Torino, Via P. Giuria 1, 10125 Torino (Italy); Fioravanti, Davide, E-mail: Fioravanti@bo.infn.it [INFN-Bologna and Dipartimento di Fisica e Astronomia, Università di Bologna, Via Irnerio 46, 40126 Bologna (Italy); Tateo, Roberto, E-mail: Tateo@to.infn.it [Dipartimento di Fisica and INFN, Università di Torino, Via P. Giuria 1, 10125 Torino (Italy)

2013-12-21

We study in detail the analytic properties of the Thermodynamic Bethe Ansatz (TBA) equations for the anomalous dimensions of composite operators in the planar limit of the 3D N=6 superconformal Chern–Simons gauge theory and derive functional relations for the jump discontinuities across the branch cuts in the complex rapidity plane. These relations encode the analytic structure of the Y functions and are extremely similar to the ones obtained for the previously-studied AdS{sub 5}/CFT{sub 4} case. Together with the Y-system and more basic analyticity conditions, they are completely equivalent to the TBA equations. We expect these results to be useful to derive alternative nonlinear integral equations for the AdS{sub 4}/CFT{sub 3} spectrum.

Early discontinuation of attention-deficit/hyperactivity disorder drug treatment: a danish nationwide drug utilization study

DEFF Research Database (Denmark)

Pottegård, Anton; Bjerregaard, B. K.; Kortegaard, L. S.

2015-01-01

Knowledge of patterns of treatment discontinuation in attention-deficit/hyperactivity disorder (ADHD) drug treatment is of importance, for both the clinical practice and the study of long-term treatment outcomes. The purpose of this study was to describe early discontinuation of ADHD drug treatme...

Reasons for discontinuation of subcutaneous biologic therapy in the treatment of rheumatoid arthritis: a patient perspective

Directory of Open Access Journals (Sweden)

Bolge SC

2015-01-01

Full Text Available Susan C Bolge,1 Amir Goren,2 Neeta Tandon1 1Health Economics and Outcomes Research, Janssen Scientific Affairs, LLC, Horsham, PA, USA; 2Health Outcomes Practice, Kantar Health, New York, NY, USA Objective: To examine reasons why rheumatoid arthritis patients discontinued subcutaneous (SQ anti-tumor necrosis factor (anti-TNF treatment in the past 12 months, so as to help inform successful, uninterrupted therapy.Methods: Data were collected in March and April 2011 using self-reported, internet-based questionnaires. Study inclusion criteria comprised: rheumatoid arthritis diagnosis; discontinuation of SQ anti-TNF medication (adalimumab, certolizumab, etanercept, or golimumab within the past 12 months; aged ≥18 years; United States residency; and consent to participate. Patients reported primary and other reasons for discontinuation of their most recently discontinued anti-TNF.Results: Questionnaires from 250 patients were analyzed; 72.8% were female, 80.8% were white, and median age was 51 years. Patients had discontinued etanercept (n=109, adalimumab (n=98, certolizumab (n=24, or golimumab (n=19 within the past 12 months. When prompted about their primary reason for discontinuation, lack of effectiveness (40.8% was cited most often, followed by injection experience (18.4%. Combining prompted primary and other reasons for discontinuation, 60.8% of patients reported lack of effectiveness, while 40.8% reported injection experience, which included: pain/burning/discomfort after injection (14.4%; pain/burning/discomfort during injection (13.2%; injection reactions such as redness/swelling after injection (12.4%; dislike of self-injection (11.6%; dislike of frequency of injection (10.4%; and fear of injection/needles (6.8%. Conclusion: From the patient perspective, there are unmet needs with regard to the effectiveness and injection experience associated with SQ anti-TNF medications, which may lead to discontinuation. Treatment options with a

Structured health care for subjects with diabetic foot ulcers results in a reduction of major amputation rates

Science.gov (United States)

2013-01-01

Objective We tested the effects of structured health care for the diabetic foot in one region in Germany aiming to reduce the number of major amputations. Research design and methods In a prospective study we investigated patients with diabetic foot in a structured system of outpatient, in-patient and rehabilitative treatment. Subjects were recruited between January 1st, 2000 and December 31, 2007. All participants underwent a two-year follow-up. The modified University of Texas Wound Classification System (UT) was the basis for documentation and data analysis. We evaluated numbers of major amputations, rates of ulcer healing and mortality. In order to compare the effect of the structured health care program with usual care in patients with diabetic foot we evaluated the same parameters at another regional hospital without interdisciplinary care of diabetic foot (controls). Results 684 patients with diabetic foot and 508 controls were investigated. At discharge from hospital 28.3% (structured health care program, SHC) vs. 23.0% (controls) of all ulcers had healed completely. 51.5% (SHC) vs. 49.8% (controls) were in UT grade 1. Major amputations were performed in 32 subjects of the structured health care program group (4.7%) vs. 110 (21.7%) in controls (p<0.0001). Mortality during hospitalization was 2.5% (SHC) vs. 9.4% in controls (p<0.001). Conclusions With the structured health care program we achieved a significant reduction of major amputation rates by more than 75% as compared to standard care. PMID:23497152

Finite Element Quadrature of Regularized Discontinuous and Singular Level Set Functions in 3D Problems

Directory of Open Access Journals (Sweden)

Nicola Ponara

2012-11-01

Full Text Available Regularized Heaviside and Dirac delta function are used in several fields of computational physics and mechanics. Hence the issue of the quadrature of integrals of discontinuous and singular functions arises. In order to avoid ad-hoc quadrature procedures, regularization of the discontinuous and the singular fields is often carried out. In particular, weight functions of the signed distance with respect to the discontinuity interface are exploited. Tornberg and Engquist (Journal of Scientific Computing, 2003, 19: 527–552 proved that the use of compact support weight function is not suitable because it leads to errors that do not vanish for decreasing mesh size. They proposed the adoption of non-compact support weight functions. In the present contribution, the relationship between the Fourier transform of the weight functions and the accuracy of the regularization procedure is exploited. The proposed regularized approach was implemented in the eXtended Finite Element Method. As a three-dimensional example, we study a slender solid characterized by an inclined interface across which the displacement is discontinuous. The accuracy is evaluated for varying position of the discontinuity interfaces with respect to the underlying mesh. A procedure for the choice of the regularization parameters is proposed.

Block volume estimation from the discontinuity spacing measurements of mesozoic limestone quarries, Karaburun Peninsula, Turkey.

Science.gov (United States)

Elci, Hakan; Turk, Necdet

2014-01-01

Block volumes are generally estimated by analyzing the discontinuity spacing measurements obtained either from the scan lines placed over the rock exposures or the borehole cores. Discontinuity spacing measurements made at the Mesozoic limestone quarries in Karaburun Peninsula were used to estimate the average block volumes that could be produced from them using the suggested methods in the literature. The Block Quality Designation (BQD) ratio method proposed by the authors has been found to have given in the same order of the rock block volume to the volumetric joint count (J(v)) method. Moreover, dimensions of the 2378 blocks produced between the years of 2009 and 2011 in the working quarries have been recorded. Assuming, that each block surfaces is a discontinuity, the mean block volume (V(b)), the mean volumetric joint count (J(vb)) and the mean block shape factor of the blocks are determined and compared with the estimated mean in situ block volumes (V(in)) and volumetric joint count (J(vi)) values estimated from the in situ discontinuity measurements. The established relations are presented as a chart to be used in practice for estimating the mean volume of blocks that can be obtained from a quarry site by analyzing the rock mass discontinuity spacing measurements.

Block Volume Estimation from the Discontinuity Spacing Measurements of Mesozoic Limestone Quarries, Karaburun Peninsula, Turkey

Directory of Open Access Journals (Sweden)

Hakan Elci

2014-01-01

Full Text Available Block volumes are generally estimated by analyzing the discontinuity spacing measurements obtained either from the scan lines placed over the rock exposures or the borehole cores. Discontinuity spacing measurements made at the Mesozoic limestone quarries in Karaburun Peninsula were used to estimate the average block volumes that could be produced from them using the suggested methods in the literature. The Block Quality Designation (BQD ratio method proposed by the authors has been found to have given in the same order of the rock block volume to the volumetric joint count (Jv method. Moreover, dimensions of the 2378 blocks produced between the years of 2009 and 2011 in the working quarries have been recorded. Assuming, that each block surfaces is a discontinuity, the mean block volume (Vb, the mean volumetric joint count (Jvb and the mean block shape factor of the blocks are determined and compared with the estimated mean in situ block volumes (Vin and volumetric joint count (Jvi values estimated from the in situ discontinuity measurements. The established relations are presented as a chart to be used in practice for estimating the mean volume of blocks that can be obtained from a quarry site by analyzing the rock mass discontinuity spacing measurements.

How Can Comparison Groups Strengthen Regression Discontinuity Designs?

Science.gov (United States)

Wing, Coady; Cook, Thomas D.

2011-01-01

In this paper, the authors examine some of the ways that different types of non-equivalent comparison groups can be used to strengthen causal inferences based on regression discontinuity design (RDD). First, they consider a design that incorporates pre-test data on assignment scores and outcomes that were collected either before the treatment…

Exploration of lateral discontinuities with shallow seismic reflection

International Nuclear Information System (INIS)

Kose, K.; Ecevitoglu, B.

2007-01-01

Shallow seismic reflection method is used to for research of mine, fault and stratigraphy and these researches have been result successfully. Survey parameters should be determined with detailed pre-research before data collection. In this study, limestone-fly sch discontinuity experienced at surface and its extension was researched with collected reflection data

Adaptive oriented PDEs filtering methods based on new controlling speed function for discontinuous optical fringe patterns

Science.gov (United States)

Zhou, Qiuling; Tang, Chen; Li, Biyuan; Wang, Linlin; Lei, Zhenkun; Tang, Shuwei

2018-01-01

The filtering of discontinuous optical fringe patterns is a challenging problem faced in this area. This paper is concerned with oriented partial differential equations (OPDEs)-based image filtering methods for discontinuous optical fringe patterns. We redefine a new controlling speed function to depend on the orientation coherence. The orientation coherence can be used to distinguish the continuous regions and the discontinuous regions, and can be calculated by utilizing fringe orientation. We introduce the new controlling speed function to the previous OPDEs and propose adaptive OPDEs filtering models. According to our proposed adaptive OPDEs filtering models, the filtering in the continuous and discontinuous regions can be selectively carried out. We demonstrate the performance of the proposed adaptive OPDEs via application to the simulated and experimental fringe patterns, and compare our methods with the previous OPDEs.

Regularization of discontinuous foliations: Blowing up and sliding conditions via Fenichel theory

Science.gov (United States)

Panazzolo, Daniel; da Silva, Paulo R.

2017-12-01

We study the regularization of an oriented 1-foliation F on M ∖ Σ where M is a smooth manifold and Σ ⊂ M is a closed subset, which can be interpreted as the discontinuity locus of F. In the spirit of Filippov's work, we define a sliding and sewing dynamics on the discontinuity locus Σ as some sort of limit of the dynamics of a nearby smooth 1-foliation and obtain conditions to identify whether a point belongs to the sliding or sewing regions.

Premature Discontinuation of Prospective Clinical Studies Approved by a Research Ethics Committee - A Comparison of Randomised and Non-Randomised Studies.

Directory of Open Access Journals (Sweden)

Anette Blümle

Full Text Available Premature discontinuation of clinical studies affects about 25% of randomised controlled trials (RCTs which raises concerns about waste of scarce resources for research. The risk of discontinuation of non-randomised prospective studies (NPSs is yet unclear.To compare the proportion of discontinued studies between NPSs and RCTs that received ethical approval.We systematically surveyed prospective longitudinal clinical studies that were approved by a single REC in Freiburg, Germany between 2000 and 2002. We collected study characteristics, identified subsequent publications, and surveyed investigators to elucidate whether a study was discontinued and, if so, why.Of 917 approved studies, 547 were prospective longitudinal studies (306 RCTs and 241 NPSs. NPSs were on average smaller than RCTs, more frequently single centre and pilot studies, and less frequently funded by industry. NPSs were less frequently discontinued than RCTs: 32/221 (14% versus 78/288 (27%, p<0.001, missing data excluded. Poor recruitment was the most frequent reason for discontinuation in both NPSs (36% and RCTs (37%.Compared to RCTs, NPSs were at lower risk for discontinuation. Measures to reliably predict, sustain, and stimulate recruitment could prevent discontinuation of many RCTs but also of some NPSs.

Exponential discontinuous numerical scheme for electron transport in the continuous slowing down approximation

International Nuclear Information System (INIS)

Prinja, A.K.

1997-01-01

A nonlinear discretization scheme in space and energy, based on the recently developed exponential discontinuous method, is applied to continuous slowing down dominated electron transport (i.e., in the absence of scattering.) Numerical results for dose and charge deposition are obtained and compared against results from the ONELD and ONEBFP codes, and against exact results from an adjoint Monte Carlo code. It is found that although the exponential discontinuous scheme yields strictly positive and monotonic solutions, the dose profile is considerably straggled when compared to results from the linear codes. On the other hand, the linear schemes produce negative results which, furthermore, do not damp effectively in some cases. A general conclusion is that while yielding strictly positive solutions, the exponential discontinuous method does not show the crude cell accuracy for charged particle transport as was apparent for neutral particle transport problems

The 1D Richards' equation in two layered soils: a Filippov approach to treat discontinuities

Science.gov (United States)

Berardi, Marco; Difonzo, Fabio; Vurro, Michele; Lopez, Luciano

2018-05-01

The infiltration process into the soil is generally modeled by the Richards' partial differential equation (PDE). In this paper a new approach for modeling the infiltration process through the interface of two different soils is proposed, where the interface is seen as a discontinuity surface defined by suitable state variables. Thus, the original 1D Richards' PDE, enriched by a particular choice of the boundary conditions, is first approximated by means of a time semidiscretization, that is by means of the transversal method of lines (TMOL). In such a way a sequence of discontinuous initial value problems, described by a sequence of second order differential systems in the space variable, is derived. Then, Filippov theory on discontinuous dynamical systems may be applied in order to study the relevant dynamics of the problem. The numerical integration of the semidiscretized differential system will be performed by using a one-step method, which employs an event driven procedure to locate the discontinuity surface and to adequately change the vector field.

Seismic Observations Indicating That the 2015 Ogasawara (Bonin) Earthquake Ruptured Beneath the 660 km Discontinuity

Science.gov (United States)

Kuge, Keiko

2017-11-01

The termination of deep earthquakes at a depth of 700 km is a key feature for understanding the physical mechanism of deep earthquakes. The 680 km deep 30 May 2015, Ogasawara (Bonin) earthquake (Mw 7.9) and its aftershocks were recorded by seismic stations at distances from 7° to 19°. Synthetic seismograms indicate that the P waveforms depend on whether the earthquake is located above or below the 660 km discontinuity. In this study, I show that broadband recordings indicate that the 2015 earthquake may have occurred below the 660 km velocity discontinuity. Recordings of the P wave from the strongest aftershock lack evidence for wave triplication expected when a subhorizontal discontinuity underlies the hypocenter. Theoretical waveforms computed with a 660 km discontinuity above the aftershock and mainshock match the observed waveforms more accurately. These observations may indicate earthquake ruptures due to mantle minerals other than olivine or strong deformation of the 660 km phase transition.

Predictors of premature discontinuation of outpatient treatment after discharge of patients with posttraumatic stress disorder.

Science.gov (United States)

Wang, Hee Ryung; Woo, Young Sup; Jun, Tae-Youn; Bahk, Won-Myong

2015-01-01

This study aimed to examine the sociodemographic and disease-related variables associated with the premature discontinuation of psychiatric outpatient treatment after discharge among patients with noncombat-related posttraumatic stress disorder. We retrospectively reviewed the medical records of patients who were discharged with a diagnosis of posttraumatic stress disorder. Fifty-five percent of subjects (57/104) prematurely discontinued outpatient treatment within 6 months of discharge. Comparing sociodemographic variables between the 6-month non-follow-up group and 6-month follow-up group, there were no variables that differed between the two groups. However, comparing disease-related variables, the 6-month follow-up group showed a longer hospitalization duration and higher Global Assessment of Function score at discharge. The logistic regression analysis showed that a shorter duration of hospitalization predicted premature discontinuation of outpatient treatment within 6 months of discharge. The duration of psychiatric hospitalization for posttraumatic stress disorder appeared to influence the premature discontinuation of outpatient treatment after discharge.

The influence of traditional medicine and religion on discontinuation of ART in an urban informal settlement in Nairobi, Kenya.

Science.gov (United States)

Unge, Christian; Ragnarsson, Anders; Ekström, Anna Mia; Indalo, Dorcus; Belita, Alice; Carter, Jane; Ilako, Festus; Södergård, Björn

2011-07-01

The objective of this study was to explore the influence of traditional medicine and religion on discontinuation of antiretroviral therapy (ART) in one of Africa's largest informal urban settlement, Kibera, in Nairobi, Kenya. Semi-structured face-to-face interviews were conducted with 20 patients discontinuing the African Medical and Research Foundation (AMREF) ART program in Kibera due to issues related to traditional medicine and religion. Traditional medicine and religion remain important in many people's lives after ART initiation, but these issues are rarely addressed in a positive way during ART counseling. Many patients found traditional medicine and their religious beliefs to be in conflict with clinic treatment advice. Patients described a decisional process, prior to the actual drop-out from the ART program that involved a trigger event, usually a specific religious event, or a meeting with someone using traditional medicine that influenced them to take the decision to stop ART. Discontinuation of ART could be reduced if ART providers acknowledged and addressed the importance of religious issues and traditional medicine in the lives of patients, especially in similar resource-poor settings. Telling patients not to mix ART and traditional medicine appeared counter-productive in this setting. Introducing an open discussion around religious beliefs and the pros and cons of traditional medicine as part of standard counseling, may prevent drop-out from ART when side effects or opportunistic infections occur.

Depth and sharpness variations of 410-km and 660-km discontinuities in North China Craton from dense array ambient noise interferometry

Science.gov (United States)

Yao, H.; Feng, J.; Poli, P.; Fang, L.; Wu, Y.

2017-12-01

Recent studies have demonstrated that body waves between pairs of stations can be successfully retrieved from ambient noise cross-correlation at both regional and global scales, although surface waves are the dominant signals. However, it is still difficult to use these retrieved body wave signals to map lateral depth variations of main structural discontinuities or velocity contrasts because of its low signal to noise ratio (SNR). In this research, based on a dense seismic array in eastern North China Craton, reflected P-wave signals from 410-km and 660-km discontinuities can be successfully recovered from ambient noise cross-correlation. To improve SNR of the reflected phases, the cross-correlations are stacked within each bin with the phase-weighted stack (PWS) method. In addition, there exist apparent spatial variations of the relative amplitude ratios between the reflected P410P and P660P phases. The retrieved P410P and P660P phases from stacked correlations reveal lateral variations of both depths and sharpness of the 410-km and 660-km discontinuities along two profiles, which may be related with hot material upwelling and the effect of stagnant Pacific plate in the transition zone beneath North China Craton. The imaging results are generally consistent with the results from teleseismic receiver functions, which demonstrate the possibility of mapping high-resolution topography and sharpness of deep internal discontinuities without earthquake-station geometric limitations. Future joint imaging with both interferometric and passive signals will be better for understanding interface architectures and related dynamic processes of the Earth.

Saving Teens: Using a Policy Discontinuity to Estimate the Effects of Medicaid Eligibility

OpenAIRE

Bruce D. Meyer; Laura R. Wherry

2012-01-01

This paper uses a policy discontinuity to identify the immediate and long-term effects of public health insurance coverage during childhood. Our identification strategy exploits a unique feature of several early Medicaid expansions that extended eligibility only to children born after September 30, 1983. This feature resulted in a large discontinuity in the lifetime years of Medicaid eligibility of children at this birthdate cutoff. Those with family incomes at or just below the poverty line ...

Effects of discontinuous magnetic permeability on magnetodynamic problems

KAUST Repository

Guermond, J.-L.

2011-07-01

A novel approximation technique using Lagrange finite elements is proposed to solve magneto-dynamics problems involving discontinuous magnetic permeability and non-smooth interfaces. The algorithm is validated on benchmark problems and is used for kinematic studies of the Cadarache von Kármán Sodium 2 (VKS2) experimental fluid dynamo. © 2011 Elsevier Inc.

Discontinuous Galerkin finite element methods for hyperbolic nonconservative partial differential equations

International Nuclear Information System (INIS)

Rhebergen, S.; Bokhove, O.; Vegt, J.J.W. van der

2008-01-01

We present space- and space-time discontinuous Galerkin finite element (DGFEM) formulations for systems containing nonconservative products, such as occur in dispersed multiphase flow equations. The main criterium we pose on the weak formulation is that if the system of nonconservative partial differential equations can be transformed into conservative form, then the formulation must reduce to that for conservative systems. Standard DGFEM formulations cannot be applied to nonconservative systems of partial differential equations. We therefore introduce the theory of weak solutions for nonconservative products into the DGFEM formulation leading to the new question how to define the path connecting left and right states across a discontinuity. The effect of different paths on the numerical solution is investigated and found to be small. We also introduce a new numerical flux that is able to deal with nonconservative products. Our scheme is applied to two different systems of partial differential equations. First, we consider the shallow water equations, where topography leads to nonconservative products, in which the known, possibly discontinuous, topography is formally taken as an unknown in the system. Second, we consider a simplification of a depth-averaged two-phase flow model which contains more intrinsic nonconservative products

Application of Discontinuous PWM Modulation in Active Power Filters

DEFF Research Database (Denmark)

Blaabjerg, Frede; Asiminoaei, Lucian; Rodriguez, Pedro

2008-01-01

Classical discontinuous pulsewidth modulations (DPWMs) may not be efficiently applied in active power filters (APFs), because it is hard to predict the peak values of the inverter current, and consequently it is difficult to calculate the position of the clamped interval, that minimizes...

Sustained major molecular response on interferon alpha-2b in two patients with polycythemia vera

DEFF Research Database (Denmark)

Larsen, T.S.; Pallisgaard, N.; Andersen, M.T.

2008-01-01

with a JAK2 V617F allele burden below 1.0% in two patients with polycythemia vera treated with interferon alpha-2b (IFN-2b). Discontinuation of IFN-2b in one of the patients was followed by a sustained long-lasting (12 months of follow-up) major molecular response Udgivelsesdato: 2008/10...

-Error Estimates of the Extrapolated Crank-Nicolson Discontinuous Galerkin Approximations for Nonlinear Sobolev Equations

Directory of Open Access Journals (Sweden)

Lee HyunYoung

2010-01-01

Full Text Available We analyze discontinuous Galerkin methods with penalty terms, namely, symmetric interior penalty Galerkin methods, to solve nonlinear Sobolev equations. We construct finite element spaces on which we develop fully discrete approximations using extrapolated Crank-Nicolson method. We adopt an appropriate elliptic-type projection, which leads to optimal error estimates of discontinuous Galerkin approximations in both spatial direction and temporal direction.

A Streaming Language Implementation of the Discontinuous Galerkin Method

Science.gov (United States)

Barth, Timothy; Knight, Timothy

2005-01-01

We present a Brook streaming language implementation of the 3-D discontinuous Galerkin method for compressible fluid flow on tetrahedral meshes. Efficient implementation of the discontinuous Galerkin method using the streaming model of computation introduces several algorithmic design challenges. Using a cycle-accurate simulator, performance characteristics have been obtained for the Stanford Merrimac stream processor. The current Merrimac design achieves 128 Gflops per chip and the desktop board is populated with 16 chips yielding a peak performance of 2 Teraflops. Total parts cost for the desktop board is less than $20K. Current cycle-accurate simulations for discretizations of the 3-D compressible flow equations yield approximately 40-50% of the peak performance of the Merrimac streaming processor chip. Ongoing work includes the assessment of the performance of the same algorithm on the 2 Teraflop desktop board with a target goal of achieving 1 Teraflop performance.

Constitutive model of discontinuous plastic flow at cryogenic temperatures

CERN Document Server

Skoczen, B; Bielski, J; Marcinek, D

2010-01-01

FCC metals and alloys are frequently used in cryogenic applications, nearly down to the temperature of absolute zero, because of their excellent physical and mechanical properties including ductility. Some of these materials, often characterized by the low stacking fault energy (LSFE), undergo at low temperatures three distinct phenomena: dynamic strain ageing (DSA), plastic strain induced transformation from the parent phase (gamma) to the secondary phase (alpha) and evolution of micro-damage. The constitutive model presented in the paper is focused on the discontinuous plastic flow (serrated yielding) and takes into account the relevant thermodynamic background. The discontinuous plastic flow reflecting the DSA effect is described by the mechanism of local catastrophic failure of Lomer-Cottrell (LC) locks under the stress fields related to the accumulating edge dislocations (below the transition temperature from the screw dislocations to the edge dislocations mode T-1). The failure of LC locks leads to mass...

Triaxiality in the even-mass Hg isotopes: A discontinuity at 200Hg

International Nuclear Information System (INIS)

Morrison, I.; Spear, R.H.

1981-01-01

The mass dependence of excitation energies of the 2 + 1 , 2 + 2 , and 4 + 1 states of the even-mass Hg isotopes, and of some related B(E2) values, shows a marked discontinuity at 200 Hg. Analysis of B(E2;0 + 1 →2 + 1 ) values in terms of an extended interacting boson approximation model suggests that this discontinuity is due to a change in the proton and neutron distributions at 200 Hg. Apart from 200 Hg, the data favor γ-soft models rather than the rigid triaxial-rotor model

Twenty-four months of antipsychotic treatment in children and adolescents with first psychotic episode: discontinuation and tolerability.

Science.gov (United States)

Noguera, Ana; Ballesta, Patricia; Baeza, Immaculada; Arango, Celso; de la Serna, Elena; González-Pinto, Ana; Parellada, Mara; Graell, Montserrat; Moreno, Carmen; Otero, Soraya; Castro-Fornieles, Josefina

2013-08-01

The Child and Adolescent First-Episode Psychosis Study is a longitudinal study of early-onset first psychotic episodes. This report describes the naturalistic psychopharmacological treatment administered during a 24-month follow-up period, as well as discontinuation rates, reasons for discontinuation, and adverse effects. The sample comprised 110 patients, aged 9 to 17 years, with a first psychotic episode. Pharmacological treatment, changes, reasons for discontinuation, and the UKU (Udvalg for Kliniske Undersogelser) Side Effect Rating Scale were registered at 6, 12, and 24 months of follow-up. Second-generation antipsychotics, especially risperidone, quetiapine, and olanzapine, were the most commonly used. The discontinuation rate was 44.5% at 6 months, 59.1% at 12 months, and 70.9% at 24 months. Discontinuation rates or reasons for discontinuation (adverse reaction, insufficient response, and other) did not differ significantly between antipsychotics. At 6 months, significant differences were found in body mass index increase and body mass index z score increase, which were higher with olanzapine, and in neurological effects, which were higher with risperidone; at 12 and 24 months, these differences were no longer significant. High maintenance rates were found in the clozapine group, although they had higher scores on the autonomic subscale of the UKU. A long follow-up period reveals high discontinuation rates similar to those observed in adults, particularly during the first year. No differences were found between antipsychotics. Differences in adverse effects were found at 6 months but not subsequently after changes in treatment. Clozapine had a high maintenance rate, and its tolerability was comparable to that of other antipsychotics.

NATURAL COURSE OF PATIENTS DISCONTINUING TREATMENT FOR AGE-RELATED MACULAR DEGENERATION AND FACTORS ASSOCIATED WITH VISUAL PROGNOSIS.

Science.gov (United States)

Kim, Jae Hui; Chang, Young Suk; Kim, Jong Woo

2017-12-01

To evaluate the 24-month natural course of visual changes in patients discontinuing treatment despite persistent or recurrent fluid and factors predictive of visual prognosis. This retrospective, observational study included 35 patients (35 eyes) who initially received anti-vascular endothelial growth factor treatment for neovascular age-related macular degeneration (AMD), but discontinued treatment despite persistent or recurrent fluid. The best-corrected visual acuity (BCVA) at treatment discontinuation was determined and compared with the 24-month BCVA, which was then compared between polypoidal choroidal vasculopathy and other neovascular age-related macular degeneration subtypes. Baseline characteristics predictive of visual outcome and the degree of visual change were also analyzed. The mean number of anti-vascular endothelial growth factor injections before treatment discontinuation was 4.0 ± 1.6. The mean logarithm of minimal angle of resolution of BCVA at treatment discontinuation and that at 24 months were 1.02 ± 0.20 (Snellen equivalents = 20/209) and 1.60 ± 0.56 (20/796), respectively (P age-related macular degeneration subtypes (P = 0.803). The type of fluid (intraretinal fluid vs. no intraretinal fluid) was predictive of 24-month BCVA (P = 0.004) and the degree of changes in BCVA (P = 0.043). Marked deterioration in visual acuity was noted in patients discontinuing treatment, regardless of neovascular age-related macular degeneration subtypes. The presence of intraretinal fluid was associated with worse visual prognosis, suggesting that patients with intraretinal fluid should be strongly warned about their poor prognosis before they decide to discontinue treatment.

Localization to Chromosomes of Structural Genes for the Major Protease Inhibitors of Barley Grains

DEFF Research Database (Denmark)

Hejgaard, Jørn; Bjørn, S.E.; Nielsen, Gunnar Gissel

1984-01-01

Wheat-barley chromosome addition lines were compared by isoelectric focusing of protein extracts to identify chromosomes carrying loci for the major immunochemically distinct protease inhibitors of barley grains. Structural genes for the following inhibitors were localized: an inhibitor of both...... endogenous α-amylase 2 and subtilisin (ASI) on chromosome 2, two chymotrypsin/subtilisin inhibitors (CI-1 and CI-2) on chromosome 5 (long arm) and the major trypsin inhibitor (TI-1) on chromosome 3....

Thermal-structural response of EBR-II major components under reactor operational transients

International Nuclear Information System (INIS)

Chang, L.K.; Lee, M.J.

1983-01-01

Until recently, the LMFBR safety research has been focused primarily on severe but highly unlikely accident, such as hypothetical-core-disruptive accidents (HCDA's), and not enough attention has been given to accident prevention, which is less severe but more likely sequence. The objective of the EBR-II operational reliability testing (ORT) is to demonstrate that the reactor can be designed and operated to prevent accident. A series of mild duty cycles and overpower transients were designed for accident prevention tests. An assessment of the EBR-II major plant components has been performed to assure structural integrity of the reactor plant for the ORT program. In this paper, the thermal-structural response and structural evaluation of the reactor vessel, the reactor-vessel cover, the intermediate heat exchanger (IHX) and the superheater are presented

Factors associated with use and discontinuation of Implanon ...

African Journals Online (AJOL)

Factors associated with use and discontinuation of Implanon contraceptive in ... The low CPR is the direct cause of the high total fertility of 5.7 in Nigeria. ... This is especially more true with the use of long acting reversible contraceptive methods like implanon which ... Their mean age was 31 years with a range of 16 to 53.

An entropy stable nodal discontinuous Galerkin method for the two dimensional shallow water equations on unstructured curvilinear meshes with discontinuous bathymetry

Energy Technology Data Exchange (ETDEWEB)

Wintermeyer, Niklas [Mathematisches Institut, Universität zu Köln, Weyertal 86-90, 50931 Köln (Germany); Winters, Andrew R., E-mail: awinters@math.uni-koeln.de [Mathematisches Institut, Universität zu Köln, Weyertal 86-90, 50931 Köln (Germany); Gassner, Gregor J. [Mathematisches Institut, Universität zu Köln, Weyertal 86-90, 50931 Köln (Germany); Kopriva, David A. [Department of Mathematics, The Florida State University, Tallahassee, FL 32306 (United States)

2017-07-01

We design an arbitrary high-order accurate nodal discontinuous Galerkin spectral element approximation for the non-linear two dimensional shallow water equations with non-constant, possibly discontinuous, bathymetry on unstructured, possibly curved, quadrilateral meshes. The scheme is derived from an equivalent flux differencing formulation of the split form of the equations. We prove that this discretization exactly preserves the local mass and momentum. Furthermore, combined with a special numerical interface flux function, the method exactly preserves the mathematical entropy, which is the total energy for the shallow water equations. By adding a specific form of interface dissipation to the baseline entropy conserving scheme we create a provably entropy stable scheme. That is, the numerical scheme discretely satisfies the second law of thermodynamics. Finally, with a particular discretization of the bathymetry source term we prove that the numerical approximation is well-balanced. We provide numerical examples that verify the theoretical findings and furthermore provide an application of the scheme for a partial break of a curved dam test problem.

Discontinuation of the Bulletin's menu page

CERN Document Server

Publications Section

2005-01-01

The menus of the various CERN restaurants will no longer be published in the Bulletin as of Monday 4 April (issue No. 14/2005). The menu pages are being discontinued both as a savings measure and due to the low level of interest in this section of the Bulletin. The most recent survey of Bulletin readers showed that only 13% of the people questioned regularly read the menu section, compared to between 40% and 85% in the case of the other sections. Publications Section SG/CO Tel. 79971

Discontinuation of the Bulletin's menu page

CERN Multimedia

Publications Section

2005-01-01

The menus of the various CERN restaurants will no longer be published in the Bulletin as of Monday 4 April (issue No. 14/2005). The menu pages are being discontinued both as a savings measure and due to the low level of interest in this section of the Bulletin. The most recent survey of Bulletin readers showed that only 13% of the people questioned regularly read the menu section, compared to between 40% and 85% in the case of the other sections. Publications Section DSU-CO Tel. 79971

Continuity and discontinuity in the Inuit culture of Greenland

NARCIS (Netherlands)

Kylstra, Hans P.

1977-01-01

In november 1976 the Arctic Centre of the University of Gronlngen organized its third symposium. The third symposium was a Dutch-Danish one on the Greenlandic Inuit: 'Continuity and Discontinuity In Greenlandic Arctic Culture'. As on the two previous occasions, an exhibition was organized.

USING CUSTOM TRIFLANGE IMPLANT IN REVISION HIP ARTHROPLASTY IN PATIENT WITH PELVIC DISCONTINUITY (CASE REPORT

Directory of Open Access Journals (Sweden)

R. M. Tikhilov

2016-01-01

Full Text Available Revision hip arthroplasty rate is growing, and pelvic discontinuity rate ranges from 1% to 5% of acetabular component revision reasons. According to AAOS acetabular defects classification, pelvic discontinuity is fourth type defect in which cranial part of hip bone is separated from caudal part at acetabular level. Usually it occurs from bone loss secondary to osteolysis, infection, fracture or aseptic loosening. There are a lot of techniques for pelvis discontinuity treatment. Published results of bulk allografts and antiprotrusion cages have generally been poor. More preferable methods with acceptable rate of good results are cup-cage systems and custom triflange acetabular components(CTAC. CTACs are designed based on preoperative CT scans to build a custom titanium 3D-printed implant to address the patient's specific bone defect and provide secure fixation in the ilium, pubis, and ischium. We faced pelvic discontinuity, in which extensive iliac bone loss was added to caudal hip bone part medial displacement and pelvic ring deformity, in patient with multiple hip surgeries. Preoperative investigation called into question the possibility of using off-the-shelf hip implants, which could restore the biomechanics of the hip and provide reliable primary fixation at the same time. We present case report of the patient with pelvic discontinuity and massive bone loss treatment using a custom triflange component.

The Influence of Antithyroid Drug Discontinuation to the Therapeutic Efficacy of 131I in Hyperthyroidism

International Nuclear Information System (INIS)

Kartamihardja, A. Hussein Sundawa; Massora, Stepanus

2016-01-01

The influence of antithyroid drugs (ATDs) on the therapeutic efficacy of radioactive iodine in hyperthyroidism is still controversial. The aim of this study was to evaluate the effect of ATD discontinuation to the therapeutic efficacy of I-131 in hyperthyroidism patients with long-term ATD treatment. Retrospective study was done to 39 subjects with hyperthyroidism who had been treated with doses of 300 MBq radioactive iodine. The subjects were divided into three groups: Group I (n = 14) had been using ATDs for more than one year and discontinued more than three days; group II (n = 14) had been using ATDs for more than one year but discontinued only for three days or less, and group III (n = 11) has never been used any ATD before radioactive iodine treatment. There was a significant difference in the therapeutic efficacy after three months of radioactive iodine treatment between group I and group II (P = 0.018), group II and group III (P = 0.017), but not between group I and group III (P = 1.0). There was no observed difference on the therapeutic efficacy between the three groups at 6 months after radioactive iodine therapy (P = 0.143). Administration of ATDs more than 1 year without discontinuation decreased response of radioactive iodine treatment in 3 months follow-up. Discontinuation of ATDs for more than 3 days before radioactive iodine treatment is recommended

The Influence of Antithyroid Drug Discontinuation to the Therapeutic Efficacy of (131)I in Hyperthyroidism.

Science.gov (United States)

Kartamihardja, A Hussein Sundawa; Massora, Stepanus

2016-01-01

The influence of antithyroid drugs (ATDs) on the therapeutic efficacy of radioactive iodine in hyperthyroidism is still controversial. The aim of this study was to evaluate the effect of ATD discontinuation to the therapeutic efficacy of I-131 in hyperthyroidism patients with long-term ATD treatment. Retrospective study was done to 39 subjects with hyperthyroidism who had been treated with doses of 300 MBq radioactive iodine. The subjects were divided into three groups: Group I (n = 14) had been using ATDs for more than one year and discontinued more than three days; group II (n = 14) had been using ATDs for more than one year but discontinued only for three days or less, and group III (n = 11) has never been used any ATD before radioactive iodine treatment. There was a significant difference in the therapeutic efficacy after three months of radioactive iodine treatment between group I and group II (P = 0.018), group II and group III (P = 0.017), but not between group I and group III (P = 1.0). There was no observed difference on the therapeutic efficacy between the three groups at 6 months after radioactive iodine therapy (P = 0.143). Administration of ATDs more than 1 year without discontinuation decreased response of radioactive iodine treatment in 3 months follow-up. Discontinuation of ATDs for more than 3 days before radioactive iodine treatment is recommended.

The Influence of Antithyroid Drug Discontinuation to the Therapeutic Efficacy of 131I in Hyperthyroidism

Science.gov (United States)

Kartamihardja, A. Hussein Sundawa; Massora, Stepanus

2016-01-01

The influence of antithyroid drugs (ATDs) on the therapeutic efficacy of radioactive iodine in hyperthyroidism is still controversial. The aim of this study was to evaluate the effect of ATD discontinuation to the therapeutic efficacy of I-131 in hyperthyroidism patients with long-term ATD treatment. Retrospective study was done to 39 subjects with hyperthyroidism who had been treated with doses of 300 MBq radioactive iodine. The subjects were divided into three groups: Group I (n = 14) had been using ATDs for more than one year and discontinued more than three days; group II (n = 14) had been using ATDs for more than one year but discontinued only for three days or less, and group III (n = 11) has never been used any ATD before radioactive iodine treatment. There was a significant difference in the therapeutic efficacy after three months of radioactive iodine treatment between group I and group II (P = 0.018), group II and group III (P = 0.017), but not between group I and group III (P = 1.0). There was no observed difference on the therapeutic efficacy between the three groups at 6 months after radioactive iodine therapy (P = 0.143). Administration of ATDs more than 1 year without discontinuation decreased response of radioactive iodine treatment in 3 months follow-up. Discontinuation of ATDs for more than 3 days before radioactive iodine treatment is recommended. PMID:27134556

BEHAVIORAL ASPECTS IN COMMUNITY ORAL HEALTH PROBLEMS: A STUDY ON DENTAL TREATMENT DISCONTINUATION

Directory of Open Access Journals (Sweden)

Felix Aryadi Joelimar

2015-08-01

Full Text Available The low value of F/DMF-T ration on Performed Treatment Index in Indoneisa gives an indication of great problems in dental treatment utilization. Dental treatment utilization is affected by several obstacles, the greatest among which is psychosocial obstacles. In this study the psychosocial obstacles were detected through Intrinsic Obstacles, Obstacles in Transportation, and Obstacles in Dental Clinic related to their effects on their discontinuation of dental treatments at Balkesmas Kiara, Kecamatan Senen, Jakarta Pusat. The discontinuation of dental treatments was mostly affected by Intrinsic Obstacles, through its components as Types of Cases, Dental Anxiety Scale, and Intrinsic Motivation. Generally Obstacles in Transportation had no effects, excpet its components of Travel Time and Tiredness. Obstacles in Dental Clinic had a significant effect on the discontinuation of dental treatments through the unpleasant manner of the druggist, the hot waiting room, and the high expense on drugs.

Assessing the feasibility of the Effectiveness of Discontinuing Bisphosphonates trial: a pilot study.

Science.gov (United States)

Wright, N C; Foster, P J; Mudano, A S; Melnick, J A; Lewiecki, M E; Shergy, W J; Curtis, J R; Cutter, G R; Danila, M I; Kilgore, M L; Lewis, E C; Morgan, S L; Redden, D T; Warriner, A H; Saag, K G

2017-08-01

The Effectiveness of Discontinuing Bisphosphonates (EDGE) study is a planned pragmatic clinical trial to guide "drug holiday" clinical decision making. This pilot study assessed work flow and feasibility of such a study. While participant recruitment and treatment adherence were suboptimal, administrative procedures were generally feasible and minimally disrupted clinic flow. The comparative effectiveness of continuing or discontinuing long-term alendronate (ALN) on fractures is unknown. A large pragmatic ALN discontinuation study has potential to answer this question. We conducted a 6-month pilot study of the planned the EDGE study among current long-term ALN users (women aged ≥65 with ≥3 years of ALN use) to determine study work flow and feasibility including evaluating the administrative aspects of trial conduct (e.g., time to contract, institutional review board (IRB) approval), assessing rates of site and participant recruitment, and evaluating post-randomization outcomes, including adherence, bisphosphonate-associated adverse events, and participant and site satisfaction. We assessed outcomes 1 and 6 months after randomization. Nine sites participated, including seven community-based medical practices and two academic medical centers. On average (SD), contract execution took 3.4 (2.3) months and IRB approval took 13.9 (4.1) days. Sites recruited 27 participants (13 to continue ALN and 14 to discontinue ALN). Over follow-up, 22% of participants did not adhere to their randomization assignment: 30.8% in the continuation arm and 14.3% in the discontinuation arm. No fractures or adverse events were reported. Sites reported no issues regarding work flow, and participants were highly satisfied with the study. Administrative procedures of the EDGE study were generally feasible, with minimal disruption to clinic flow. In this convenience sample, participant recruitment was suboptimal across most practice sites. Accounting for low treatment arm adherence, a

Dynamic response of underground openings in discontinuous rock

International Nuclear Information System (INIS)

Asmis, H.W.

1984-02-01

This report examines the behaviour of underground openings in discontinuous rock in response to seismic waves associated with either earthquakes or rock bursts. A literature search revealed that well-constructed underground structures, such as would be expected for nuclear fuel waste disposal vaults, underground pumped-storage or nuclear plants, have an extremely high resistance to damage from seismic motion. To complement these qualitative results, it was necessary to examine the basic mechanisms of the entire progression of seismic motion, from wave generation and propagation, to wave interaction with the underground opening. From these investigations, it was found that unless a seismic event occurs very close to the installation, the stresses generated will be low with respect to the excavation stresses, because high stress waves are rapidly attenuated in travelling through rock. As well, an earthquake may generate extremely high accelerations, but is limited in the maximum amount of stress that it can create. The question, however, of the actual specific nature of underground seismic motions still remains essentially unanswered, although it is expected that there is a reduction in peak motions with depth due to the effect of the free surface of the earth

Immunosuppressive Drug Discontinuation in Noninfectious Uveitis From Real-Life Clinical Practice: A Survival Analysis.

Science.gov (United States)

Abásolo, Lydia; Rosales, Zulema; Díaz-Valle, David; Gómez-Gómez, Alejandro; Peña-Blanco, Rayma C; Prieto-García, Ángela; Benítez-Del-Castillo, José Manuel; Pato, Esperanza; García-Feijoo, Julián; Fernández-Gutiérrez, Benjamín; Rodriguez-Rodriguez, Luis

2016-09-01

To assess in uveitis patients the rate of immunosuppressive drug (ISD) discontinuation in real-life clinical practice, comparing this rate among ISDs. Longitudinal retrospective cohort study. We included uveitis patients attending a tertiary eye referral center from Madrid (Spain) between 1989 and 2015, prescribed any ISDs (cyclosporine, methotrexate, azathioprine, anti-TNF drugs, or others). Our main outcome was discontinuation of all ISDs owing to clinical efficacy, inefficacy, adverse drug reaction (ADR), and other medical causes. Discontinuation rates (DRs) per 100 patient-years were estimated. Variables associated with specific-cause discontinuations were analyzed using Cox bivariate and multivariate models. We analyzed 110 patients with 263 treatment courses and 665.2 patient-years of observation. Cyclosporine (66.4%), methotrexate (47.3%), azathioprine (30.9%), and anti-TNFs (30.9%) were the most frequently used ISDs. Treatment was suspended in 136 cases (mostly owing to clinical efficacy [38.2%], inefficacy [26.5%], and ADRs [22.8%]). All-cause DR with 95% confidence interval was 20.4 [17.3-24.2]. Retention rates at 1 and 10 years were 74% and 16%, respectively. In the multivariate analysis, combined treatment exhibited higher DRs owing to clinical efficacy than other ISDs in monotherapy. Conversely, nonbiologic combination therapy with azathioprine exhibited the highest DR owing to ADRs. Clinical efficacy was the most frequent cause for ISD discontinuation, followed by inefficacy and ADRs. DR owing to efficacy was higher for combination therapy. Furthermore, nonbiologic combination therapy with azathioprine was associated with a higher DR owing to ADRs. Copyright © 2016 Elsevier Inc. All rights reserved.

Impact of Oral Hygiene Discontinuation on Supragingival and Salivary Microbiomes

DEFF Research Database (Denmark)

Belstrøm, D; Sembler-Møller, M L; Grande, M A

2018-01-01

of oral hygiene. Supragingival and salivary microbiotas were processed by next-generation sequencing (Human Oral Microbe Identification using Next Generation Sequencing) and microbial community profiles were compared. Microbial composition of supragingival plaque samples collected after 4, 7, and 10 d......The purpose of the present study was to characterize and compare supragingival and salivary microbiotas during a 10-d period of oral hygiene discontinuation. We tested the hypothesis that the composition of the salivary microbiota will reflect local microbial changes associated with accumulated...... biofilm formation and maturation. Pooled supragingival plaque (n = 145) and stimulated saliva (n = 145) samples were collected and plaque and gingival indices were recorded from 29 orally healthy individuals at baseline, during oral hygiene discontinuation (days 4, 7, and 10), and 14 d after resumption...

Dropout in the treatment of erectile dysfunction with PDE5: a study on predictors and a qualitative analysis of reasons for discontinuation.

Science.gov (United States)

Carvalheira, Ana A; Pereira, Nuno Monteiro; Maroco, João; Forjaz, Vera

2012-09-01

Phosphodiesterase type 5 inhibitors (PDE5) are currently the first line treatment for erectile dysfunction (ED). However, previous research shows that PDE5 treatments have high discontinuation rates. Understanding the reasons for discontinuing PDE5 will be necessary to optimize the response to treatment. The main goals were: (i) to analyze discontinuation rate of PDE5; (ii) to identify the discontinuation predictors; and (iii) to study the reasons for discontinuation using a qualitative methodology. The PDE5 discontinuation rates, predictors, and reasons for discontinuation treatment. A total of 327 men with clinical diagnosis for ED who had been treated with PDE5 were successfully interviewed by telephone, after giving their informed consent by snail mail. Telephone interviews, concerning their ongoing treatment, were carried out using a standardized questionnaire form with quantitative and qualitative items. Participation rate was 71.8%. Of the total sample, 160 men (48.9%) had discontinued PDE5 treatment. The discontinuation rate was higher among men with diabetes (73%) and in iatrogenic group (65%), and lower in venogenic etiology (38.7%). We differentiated three groups of men who discontinued treatment (i) during the first 3 months (55.1%); (ii) between 4 and 12 months (26.9%); and (iii) after a period of 12 months (18%). Qualitative analyses revealed diverse reasons for discontinuation: non-effectiveness of PDE5 (36.8%), psychological factors (e.g., anxiety, negative emotions, fears, concerns, dysfunctional beliefs) (17.5%), erection recovery (14.4%), and concerns about the cardiovascular safety of PDE5 (8.7%) were the most common. Older men and men whose partners were involved in the treatment, were less likely to discontinue treatment. Half the subjects discontinued medication. Mostly, there was a combination of factors that led to discontinuation: non-effectiveness and psychosocial factors appear to be the main reasons. Addressing those factors will allow

Toward Continuous GPS Carrier-Phase Time Transfer: Eliminating the Time Discontinuity at an Anomaly.

Science.gov (United States)

Yao, Jian; Levine, Judah; Weiss, Marc

2015-01-01

The wide application of Global Positioning System (GPS) carrier-phase (CP) time transfer is limited by the problem of boundary discontinuity (BD). The discontinuity has two categories. One is "day boundary discontinuity," which has been studied extensively and can be solved by multiple methods [1-8]. The other category of discontinuity, called "anomaly boundary discontinuity (anomaly-BD)," comes from a GPS data anomaly. The anomaly can be a data gap (i.e., missing data), a GPS measurement error (i.e., bad data), or a cycle slip. Initial study of the anomaly-BD shows that we can fix the discontinuity if the anomaly lasts no more than 20 min, using the polynomial curve-fitting strategy to repair the anomaly [9]. However, sometimes, the data anomaly lasts longer than 20 min. Thus, a better curve-fitting strategy is in need. Besides, a cycle slip, as another type of data anomaly, can occur and lead to an anomaly-BD. To solve these problems, this paper proposes a new strategy, i.e., the satellite-clock-aided curve fitting strategy with the function of cycle slip detection. Basically, this new strategy applies the satellite clock correction to the GPS data. After that, we do the polynomial curve fitting for the code and phase data, as before. Our study shows that the phase-data residual is only ~3 mm for all GPS satellites. The new strategy also detects and finds the number of cycle slips by searching the minimum curve-fitting residual. Extensive examples show that this new strategy enables us to repair up to a 40-min GPS data anomaly, regardless of whether the anomaly is due to a data gap, a cycle slip, or a combination of the two. We also find that interference of the GPS signal, known as "jamming", can possibly lead to a time-transfer error, and that this new strategy can compensate for jamming outages. Thus, the new strategy can eliminate the impact of jamming on time transfer. As a whole, we greatly improve the robustness of the GPS CP time transfer.

Apnoea of prematurity – discontinuation of methylxanthines in a ...

African Journals Online (AJOL)

Background. Methylxanthines such as caffeine have been proven to reduce apnoea of prematurity and are often discontinued at 35 weeks' corrected gestational age (GA). Objective. To ascertain whether a caffeine protocol based on international guidelines is applicable in our setting, where GA is often uncertain. Methods.

Continuing versus discontinuing antiplatelet drugs, vasodilators, and/or cerebral ameliorators on perioperative total blood loss in total knee arthroplasty without pneumatic tourniquet

Directory of Open Access Journals (Sweden)

Sachiyuki Tsukada, MD

2018-03-01

Full Text Available Background: Although studies have supported the utility of perioperative continuation of antiplatelet drugs, vasodilators, and cerebral ameliorators in most procedures, no study compared total volume of blood loss after total knee arthroplasty (TKA in patients continuing and discontinuing these drugs. Methods: We retrospectively reviewed 266 consecutive patients undergoing TKA, and included 67 patients (25.2% taking antiplatelet drugs, vasodilators, or cerebral ameliorators in this study. All TKAs were performed without a pneumatic tourniquet. The primary outcome was perioperative total blood loss calculated from blood volume and change in hemoglobin. As subgroup analysis, we compared perioperative total blood loss in patients taking antiplatelet drugs. Results: There was no significant difference between the continuing group (n = 38 and discontinuing group (n = 29 in terms of the perioperative total blood loss (1025 ± 364 vs 1151 ± 327 mL, respectively; mean difference 126 mL; 95% confidence interval −45 to 298 mL; P = .15. No major bleeding or thrombotic events occurred in either group until postoperative 3-month follow-up. In patients taking antiplatelet drugs (n = 51, no significant difference was observed in the total blood loss between the continuing group (n = 30 and discontinuing group (n = 21 (1056 ± 287 vs 1151 ± 305 mL, respectively; mean difference 95 mL; 95% confidence interval −75 to 264 mL; P = .27. Conclusions: No significant differences in terms of perioperative total blood loss were observed between patients continuing and discontinuing study drugs. Continuing these drugs may be preferable in the perioperative period of TKA. Keywords: Knee, Primary arthroplasty, Bleeding events, Thrombotic events, Noncardiac surgery

Low Volume, Funding, Staffing and Technical Problems are Key Reasons for Discontinuation of Chat Reference Services. A review of: Radford, Marie L., and M. Kathleen Kern. “A Multiple‐case Study Investigation of the Discontinuation of Nine Chat Reference Services.” Library & Information Science Research 28.4 (Sept. 2006: 521‐47.

Directory of Open Access Journals (Sweden)

Stephanie R. Walker

2007-09-01

Full Text Available Objective – To investigate the reasons behind the cessation of 9 virtual (chat reference services.Design – Multiple case‐study investigationSetting – Academic, public, and special libraries in the United States.Subjects – Five academic libraries, 1 public library, and 3 library consortia.Methods – The initial method used to identify discontinued chat reference services was via a posting to DIG_REF, the digitalreference services listserv. From this initial posting, librarians on the list also suggested other cases, for a total of 7. Two cases later came to the authors’ attention and were added. The 9 cases included academic libraries, a public library, and consortia who used tools provided by four major software vendors, giving a good cross‐section of the types of libraries participating in VR and the major software packages available at the time. A contact person for each discontinued service was invited to participate. The participants were geographically scattered, so data were collected via e‐mail questionnaires, telephone interviews, and examination of available documents describing the services, audiences, demographics, operations, and any decision‐making processes either for starting or discontinuing the service. The authors then compared and contrasted results obtained from the 9 services. The authors analysed reasons for discontinuation of services, the decision making processes, volume of questions, service hours, marketing, evaluation, and whether the service might be restarted atsome time in the future.Main Results – Although the VR services discussed were being delivered by diverse organizations, some commonalities emerged. All 9 services used existing staff and added chat reference to their duties. In all but one case, the hours of service offered when VRbegan were within the hours that the libraries were already open to the public. In the exception (Case E, there were hours of service after the libraries were

Measuring persistence to hormonal therapy in patients with breast cancer: accounting for temporary treatment discontinuation.

Science.gov (United States)

Huiart, Laetitia; Ferdynus, Cyril; Dell'Aniello, Sophie; Bakiri, Naciba; Giorgi, Roch; Suissa, Samy

2014-08-01

Several studies have been conducted to estimate persistence to hormonal therapy among women with breast cancer (BC). Most studies focus on first treatment discontinuation. Patients, however, can have numerous periods of treatment discontinuation or treatment exposure. Our objective is to estimate persistence to tamoxifen in patients with BC while accounting for temporary treatment discontinuations and this by using multi-state (MS) models. A cohort of 10,806 women with BC having received at least one prescription of tamoxifen between 1998 and 2008 was constituted from the UK General Practice Research Database. We fitted a semi-Markov model with three states to estimate the probability of being off treatment over a 5-year period while accounting for temporary treatment discontinuations (transition between on treatment and off treatment) and competing risks (recurrence of BC or death). Non-persistence, as estimated from the MS model, ranged from 12.1% (95% confidence interval [95%CI]: 9.2-15.1) at 1 year to 14.9% (95%CI: 11.7-18.1) at 5 years. Estimations of non-persistence based on the Kaplan-Meier model were higher, i.e., 29.3% (95%CI: 28.1-30.6) at 5 years, as well as those obtained from a competing risk model, i.e., 24.0% (95%CI: 22.9-25.1). Most temporary discontinuations (94.7%) lasted less than 6 months. Temporary treatment discontinuations are frequent and should be accounted for when measuring adherence to treatment. MS models can provide a useful framework for this sort of analysis insofar as they help describe patients' complex behavior. This may help tailor interventions that improve persistence to hormonal therapy among women with BC. Copyright © 2014 John Wiley & Sons, Ltd.

Medication persistence and discontinuation of rivaroxaban versus warfarin among patients with non-valvular atrial fibrillation.

Science.gov (United States)

Nelson, Winnie W; Song, Xue; Coleman, Craig I; Thomson, Erin; Smith, David M; Damaraju, C V; Schein, Jeffrey R

2014-12-01

To compare real-world persistence and discontinuation among non-valvular atrial fibrillation (NVAF) patients on rivaroxaban and warfarin in the US. A large nationally representative US claims database was used to conduct a retrospective cohort analysis of patients with NVAF treated with rivaroxaban or warfarin from 1 July 2010 through 31 March 2013. Index date was the date of the first prescription of rivaroxaban or warfarin. All patients were followed until the earliest of inpatient death, end of continuous enrollment, or end of study period. Rivaroxaban patients were matched 1:1 by propensity scores. Medication persistence was defined as absence of refill gap of ≥ 60 days. Discontinuation was defined as no additional refill for at least 90 days and until the end of follow-up. Cox proportional hazards models were estimated to examine the adjusted hazard ratios (aHRs) of rivaroxaban vs. warfarin on non-persistence and discontinuation. A total of 32,886 NVAF patients on rivaroxaban or warfarin met the study inclusion criteria. Each of the 7259 rivaroxaban patients identified were matched 1:1 to warfarin patients. Patients on rivaroxaban had a significantly better rate of persistence (aHR: 0.63, 95% CI 0.59-0.68) and lower rate of discontinuation (aHR: 0.54, 95% CI 0.49-0.58) compared to warfarin recipients. Claims data may have contained inaccuracies and miscoding. Confounding may remain even after propensity score matching and additional adjustments in model. Refill data may not fully reflect actual medication use. Longer follow-up may produce more precise estimates of persistence and discontinuation. This matched cohort analysis indicated that rivaroxaban was associated with significantly higher medication persistence and lower discontinuation rates compared to warfarin.

Bifurcation in autonomous and nonautonomous differential equations with discontinuities

CERN Document Server

Akhmet, Marat

2017-01-01

This book is devoted to bifurcation theory for autonomous and nonautonomous differential equations with discontinuities of different types. That is, those with jumps present either in the right-hand-side or in trajectories or in the arguments of solutions of equations. The results obtained in this book can be applied to various fields such as neural networks, brain dynamics, mechanical systems, weather phenomena, population dynamics, etc. Without any doubt, bifurcation theory should be further developed to different types of differential equations. In this sense, the present book will be a leading one in this field. The reader will benefit from the recent results of the theory and will learn in the very concrete way how to apply this theory to differential equations with various types of discontinuity. Moreover, the reader will learn new ways to analyze nonautonomous bifurcation scenarios in these equations. The book will be of a big interest both for beginners and experts in the field. For the former group o...

Electrical resistivity discontinuity of iron along the melting curve

Science.gov (United States)

Wagle, Fabian; Steinle-Neumann, Gerd

2018-04-01

Discontinuous changes of electrical resistivity ρel (increase), density ϱ and isothermal compressibility βT (decrease) occur across the melting temperature of metals and can be directly related by Ziman's theory in the long-wavelength approximation. By evaluating experimental data at ambient pressure, we show that Ziman's approximation holds for iron and other simple and transition metals. Using a thermodynamic model to determine βT for γ-, ɛ- and liquid Fe and a previously published model for ρel of liquid Fe, we apply Ziman's approximation to calculate ρel of solid Fe along the melting curve. For pure Fe, we find the discontinuity in ρel to decrease with pressure and to be negligibly small at inner core boundary conditions. However, if we account for light element enrichment in the liquid outer core, the electrical resistivity decrease across the inner core boundary is predicted to be as large as 36 per cent.

Forced-air warming discontinued: periprosthetic joint infection rates drop

Directory of Open Access Journals (Sweden)

Scott D. Augustine

2017-06-01

Full Text Available Several studies have shown that the waste heat from forced-air warming (FAW escapes near the floor and warms the contaminated air resident near the floor. The waste heat then forms into convection currents that rise up and contaminate the sterile field above the surgical table. It has been shown that a single airborne bacterium can cause a periprosthetic joint infection (PJI following joint replacement surgery. We retrospectively compared PJI rates during a period of FAW to a period of air-free conductive fabric electric warming (CFW at three hospitals. Surgical and antibiotic protocols were held constant. The pooled multicenter data showed a decreased PJI rate of 78% following the discontinuation of FAW and a switch to air-free CFW (n=2034; P=0.002. The 78% reduction in joint implant infections observed when FAW was discontinued suggests that there is a link between the waste FAW heat and PJIs.

A discontinuous Poisson-Boltzmann equation with interfacial jump: homogenisation and residual error estimate.

Science.gov (United States)

Fellner, Klemens; Kovtunenko, Victor A

2016-01-01

A nonlinear Poisson-Boltzmann equation with inhomogeneous Robin type boundary conditions at the interface between two materials is investigated. The model describes the electrostatic potential generated by a vector of ion concentrations in a periodic multiphase medium with dilute solid particles. The key issue stems from interfacial jumps, which necessitate discontinuous solutions to the problem. Based on variational techniques, we derive the homogenisation of the discontinuous problem and establish a rigorous residual error estimate up to the first-order correction.

Reasons for discontinuation of implanon among users in Buffalo City ...

African Journals Online (AJOL)

Reasons for discontinuation of implanon among users in Buffalo City Metropolitan Municipality, South Africa: a cross-sectional study. Khungelwa Patricia Mrwebi, Daniel Ter Goon, Eyitayo Omolara Owolabi, Oladele Vincent Adeniyi, Eunice Seekoe, Anthony Idowu Ajayi ...

Numerical simulations of heat transfer considering hydraulic discontinuity for an enhanced geothermal system development in Seokmo Island, Korea

Science.gov (United States)

Shin, J.; Kim, K.; Hyun, Y.; Lee, K.; Lee, T.

2011-12-01

The construction of the first geothermal plant in Korea is under planning in Seokmo Island, where a few artesian wells showing relatively high water temperature of around 70 degrees were discovered lately. Geologic structure in this region is characterized by the fractured granite. Numerical simulations for the temperature evolution in a fractured geothermal reservoir in Seokmo Island under the supposed injection-extraction operating conditions were carried out using TOUGH2. A MINC model including a hydraulic discontinuity in Seokmo Island region, which reflected the analysis from several geophysical explorations and drilled rock core, was generated. Supposing the N05°E, NW83° fracture zone containing the pumping range, the numerical simulation results show that temperature of the extracted geothermal water decreases after 15 years of operation, which decreases the overall efficiency of the expected geothermal plant. This is because the colder water from the injection well, which is 400 m apart, begins to flow into the more permeable fracture zone from the 15th year, resulting in a decrease in temperature near the pumping well. Temperature distribution calculated from the simulation also shows a rise of relatively hot geothermal water along the fracture plane. All of the results are different from the non-fracture MINC model, which shows a low temperature contour in concentric circle shape around the injection well and relatively consistent extracting temperature. This demonstrates that the distribution and the structure of fracture system influence the major mass and heat flow mechanisms in geologic medium. Therefore, an intensive geologic investigation for the fractures including their structure, permeability and connecting relation is important. Acknowledgement This study was financially supported by KIGAM, KETEP and BK21.

ODEs with Preisach operator under the derivative and with discontinuous in time right-hand side

International Nuclear Information System (INIS)

Zhezherun, A; Flynn, D

2006-01-01

We consider ordinary Differential equations with a Preisach operator under the derivative. A special case when the right-hand side has discontinuities in time is studied. We present theorems about the existence and uniqueness of solutions. We also prove a theorem which describes the behavior of a solution at the points of discontinuity of the right-hand side

Derivative discontinuity and exchange-correlation potential of meta-GGAs in density-functional theory.

Science.gov (United States)

Eich, F G; Hellgren, Maria

2014-12-14

We investigate fundamental properties of meta-generalized-gradient approximations (meta-GGAs) to the exchange-correlation energy functional, which have an implicit density dependence via the Kohn-Sham kinetic-energy density. To this purpose, we construct the most simple meta-GGA by expressing the local exchange-correlation energy per particle as a function of a fictitious density, which is obtained by inverting the Thomas-Fermi kinetic-energy functional. This simple functional considerably improves the total energy of atoms as compared to the standard local density approximation. The corresponding exchange-correlation potentials are then determined exactly through a solution of the optimized effective potential equation. These potentials support an additional bound state and exhibit a derivative discontinuity at integer particle numbers. We further demonstrate that through the kinetic-energy density any meta-GGA incorporates a derivative discontinuity. However, we also find that for commonly used meta-GGAs the discontinuity is largely underestimated and in some cases even negative.

Derivative discontinuity and exchange-correlation potential of meta-GGAs in density-functional theory

International Nuclear Information System (INIS)

Eich, F. G.; Hellgren, Maria

2014-01-01

We investigate fundamental properties of meta-generalized-gradient approximations (meta-GGAs) to the exchange-correlation energy functional, which have an implicit density dependence via the Kohn-Sham kinetic-energy density. To this purpose, we construct the most simple meta-GGA by expressing the local exchange-correlation energy per particle as a function of a fictitious density, which is obtained by inverting the Thomas-Fermi kinetic-energy functional. This simple functional considerably improves the total energy of atoms as compared to the standard local density approximation. The corresponding exchange-correlation potentials are then determined exactly through a solution of the optimized effective potential equation. These potentials support an additional bound state and exhibit a derivative discontinuity at integer particle numbers. We further demonstrate that through the kinetic-energy density any meta-GGA incorporates a derivative discontinuity. However, we also find that for commonly used meta-GGAs the discontinuity is largely underestimated and in some cases even negative

The interaction of impulsive solar wind discontinuities with the magnetosphere: a multi-satellite case study

Energy Technology Data Exchange (ETDEWEB)

Labelle, J. (Dartmouth Coll., Hanover, NH (USA). Dept. of Physics and Astronomy); Kistler, L.M.; Treumann, R.A.; Baumjohann, W. (Max-Planck-Institut fuer Physik und Astrophysik, Garching (Germany, F.R.). Inst. fuer Extraterrestrische Physik); Sibeck, D.G. (Johns Hopkins Univ., Baltimore, MD (USA). Dept. of Physics); Baker, D.N. (National Aeronautics and Space Administration, Greenbelt, MD (USA). Goddard Space Flight Center); Belian, R.D. (Los Alamos National Lab., NM (USA))

1990-07-01

During the magnetic storm of 4-5 September 1984, the outbound AMPTE/IRM spacecraft stayed just outside the expanding Earth's bow shock for a period of 7.5 h. During this interval the solar wind ram pressure and the interplanetary magnetic field remained approximately constant, except for two distinct impulsive pressure pulses lasting a few minutes each. These pulses coincided with discontinuities in which the IMF changed direction by about 90deg, and the solar wind kinetic pressure decreased slightly. Accompanying these discontinuities, the following magnetospheric signatures were observed: (1) immediately after each discontinuity, the growth phase of a substorm commenced as evidenced by decreases in the flux of energetic ions at geosynchronous orbit on both the dayside and nightside, and these were followed by particle injection events on the nightside 20-35 min after the discontinuities; (2) equatorial magnetograms recorded sudden impulses in the magnetic field; and (3) after a delay of 8-12 min, the IRM detected outward motion of the bow shock, and in each case about an hour passed before the outward-moving satellite caught up again with the shock. Overall, the magnetospheric and ground signatures of the first discontinuity were larger than those of the second. It is speculated that the IMF direction and other factors such as the local time and latitude of the ground stations may be important factors in determining the magnitude of these signatures. (author).

The interaction of impulsive solar wind discontinuities with the magnetosphere: a multi-satellite case study

International Nuclear Information System (INIS)

Labelle, J.

1990-01-01

During the magnetic storm of 4-5 September 1984, the outbound AMPTE/IRM spacecraft stayed just outside the expanding Earth's bow shock for a period of 7.5 h. During this interval the solar wind ram pressure and the interplanetary magnetic field remained approximately constant, except for two distinct impulsive pressure pulses lasting a few minutes each. These pulses coincided with discontinuities in which the IMF changed direction by about 90deg, and the solar wind kinetic pressure decreased slightly. Accompanying these discontinuities, the following magnetospheric signatures were observed: (1) immediately after each discontinuity, the growth phase of a substorm commenced as evidenced by decreases in the flux of energetic ions at geosynchronous orbit on both the dayside and nightside, and these were followed by particle injection events on the nightside 20-35 min after the discontinuities; (2) equatorial magnetograms recorded sudden impulses in the magnetic field; and (3) after a delay of 8-12 min, the IRM detected outward motion of the bow shock, and in each case about an hour passed before the outward-moving satellite caught up again with the shock. Overall, the magnetospheric and ground signatures of the first discontinuity were larger than those of the second. It is speculated that the IMF direction and other factors such as the local time and latitude of the ground stations may be important factors in determining the magnitude of these signatures. (author)

It’s About Valence: Historical Continuity or Historical Discontinuity as a Threat to Social Identity

Directory of Open Access Journals (Sweden)

Jenny Roth

2017-08-01

Full Text Available National identity is underpinned by historical representations. Recent research shows that narratives presenting an in-group’s history as discontinuous rather than continuous raise collective angst, suggesting that historical discontinuity threatens social identity. This previous research has focused on positive aspects of an in-group’s past. The present research aims to extend the findings to go beyond positive histories. We suggest that when the in-group’s actions in the past are presented as negative, historical continuity instead of discontinuity will increase perceived identity threat because a negative, continuous history threatens group members’ need for a positive social identity in the present. In an experiment with a sample size of N = 316, we manipulated the narrated valence of in-group actions during the historical event of the approval of the German constitutional law by framing the group’s actions in either positive or negative terms. In addition, we presented the in-group’s history as connected or disconnected to the in-group’s present. Results demonstrate that historical continuity only decreased identity threat compared to historical discontinuity when the in-group’s past behavior was presented as positive. When the in-group’s past was presented as negative, continuity even increased identity threat compared to historical discontinuity. These results were particularly pronounced for people who strongly identified with their national in-group. We discuss implications of the findings for political communication and managing a nation’s perception of social identity threat.

Engineering and Design: Characterization and Measurement of Discontinuities in Rock Slopes

National Research Council Canada - National Science Library

1983-01-01

This ETL provides guidance for characterizing and measuring rock discontinuities on natural slopes or slopes constructed in rock above reservoirs, darn abutments, or other types of constructed slopes...

Discontinuously reinforced intermetallic matrix composites via XD synthesis. [exothermal dispersion

Science.gov (United States)

Kumar, K. S.; Whittenberger, J. D.

1992-01-01

A review is given of recent results obtained for discontinuously reinforced intermetallic matrix composites produced using the XD process. Intermetallic matrices investigated include NiAl, multiphase NiAl + Ni2AlTi, CoAl, near-gamma titanium aluminides, and Ll2 trialuminides containing minor amounts of second phase. Such mechanical properties as low and high temperature strength, compressive and tensile creep, elastic modulus, ambient ductility, and fracture toughness are discussed as functions of reinforcement size, shape, and volume fraction. Microstructures before and after deformation are examined and correlated with measured properties. An observation of interest in many of the systems examined is 'dispersion weakening' at high temperatures and high strain rates. This behavior is not specific to the XD process; rather similar observations have been reported in other discontinuous composites. Proposed mechanisms for this behavior are presented.

Addendum to "Colored-noise-induced discontinuous transitions in symbiotic ecosystems".

Science.gov (United States)

Sauga, Ako; Mankin, Romi

2005-06-01

A symbiotic ecosystem with Gompertz self-regulation and with adaptive competition between populations is studied by means of a N-species Lotka-Volterra stochastic model. The influence of fluctuating environment on the carrying capacity of a population is modeled as a dichotomous noise. The study is a follow up of previous investigations of symbiotic ecosystems subjected to the generalized Verhulst self-regulation [Phys. Rev. E 69, 061106 (2004); 65, 051108 (2002)]. In the framework of mean-field approximation the behavior of the solutions of the self-consistency equation for a stationary system is examined analytically in the full phase space of system parameters. Depending on the mutual interplay of symbiosis and competition of species, variation of noise parameters (amplitude, correlation time) can induce doubly unidirectional discontinuous transitions as well as single unidirectional discontinuous transitions of the mean population size.

Addendum to ``Colored-noise-induced discontinuous transitions in symbiotic ecosystems''

Science.gov (United States)

Sauga, Ako; Mankin, Romi

2005-06-01

A symbiotic ecosystem with Gompertz self-regulation and with adaptive competition between populations is studied by means of a N -species Lotka-Volterra stochastic model. The influence of fluctuating environment on the carrying capacity of a population is modeled as a dichotomous noise. The study is a follow up of previous investigations of symbiotic ecosystems subjected to the generalized Verhulst self-regulation [Phys. Rev. E 69, 061106 (2004); 65, 051108 (2002)]. In the framework of mean-field approximation the behavior of the solutions of the self-consistency equation for a stationary system is examined analytically in the full phase space of system parameters. Depending on the mutual interplay of symbiosis and competition of species, variation of noise parameters (amplitude, correlation time) can induce doubly unidirectional discontinuous transitions as well as single unidirectional discontinuous transitions of the mean population size.

Creep properties of discontinuous fibre composites with partly creeping fibres

International Nuclear Information System (INIS)

Bilde-Soerensen, J.B.; Lilholt, H.

1977-05-01

In a previous report (RISO-M-1810) the creep properties of discontinuous fibre composites with non-creeping fibres were analyzed. In the present report this analysis is extended to include the case of discontinuous composites with partly creeping fibres. It is shown that the creep properties of the composite at a given strain rate, epsilonsub(c), depend on the creep properties of the matrix at a strain rate higher than epsilonsub(c), and on the creep properties of the fibres at epsilonsub(c). The composite creep law is presented in a form which permits a graphical determination of the composite creep curve. This can be constructed on the basis of the matrix and the fibre creep curves by vector operations in a log epsilon vs. log sigma diagram. The matrix contribution to the creep strength can be evaluated by a simple method. (author)

Continuing weight-loss effect after topiramate discontinuation in obese persons with schizophrenia: a pilot open-label study.

Science.gov (United States)

Liang, C-S; Yang, F-W; Huang, S-Y; Ho, P-S

2014-07-01

Few studies have investigated the likelihood of weight maintenance in obese persons with schizophrenia after their initial successful weight loss. This pilot open-label study examined the efficacy of topiramate in weight loss and the trajectory of weight changes after topiramate discontinuation. This study enrolled 10 obese persons with schizophrenia. A 4-month treatment phase was started, followed by a 12-month discontinuation phase. Body weight was measured as the primary outcome every month. Secondary outcomes included leptin levels, fasting glucose, lipid profiles, and insulin resistance index. After the 4-month addition of topiramate, participants lost 1.79 kg of their body weight (95% CI=-3.03 to -0.56, p=0.005). The maximum weight reduction was 4.32 kg, occurring when topiramate had been discontinued for 12 months (95% CI=-6.41 to -2.24, p<0.001). The continuing weight-loss effect after topiramate discontinuation might have resulted from topiramate's potential to improve leptin functioning. These findings demonstrate that topiramate's weight-loss effect could not only persist during its administration, but also continue to improve after its discontinuation. © Georg Thieme Verlag KG Stuttgart · New York.

Predictors of premature discontinuation of outpatient treatment after discharge of patients with posttraumatic stress disorder

Directory of Open Access Journals (Sweden)

Wang HR

2015-03-01

Full Text Available Hee Ryung Wang, Young Sup Woo, Tae-Youn Jun, Won-Myong Bahk Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Korea Objective: This study aimed to examine the sociodemographic and disease-related variables associated with the premature discontinuation of psychiatric outpatient treatment after discharge among patients with noncombat-related posttraumatic stress disorder. Methods: We retrospectively reviewed the medical records of patients who were discharged with a diagnosis of posttraumatic stress disorder. Results: Fifty-five percent of subjects (57/104 prematurely discontinued outpatient treatment within 6 months of discharge. Comparing sociodemographic variables between the 6-month non-follow-up group and 6-month follow-up group, there were no variables that differed between the two groups. However, comparing disease-related variables, the 6-month follow-up group showed a longer hospitalization duration and higher Global Assessment of Function score at discharge. The logistic regression analysis showed that a shorter duration of hospitalization predicted premature discontinuation of outpatient treatment within 6 months of discharge. Conclusion: The duration of psychiatric hospitalization for posttraumatic stress disorder appeared to influence the premature discontinuation of outpatient treatment after discharge. Keywords: posttraumatic stress disorder, discontinuation, compliance, predictor

Relativistic transport equation for a discontinuity wave of multiplicity one

Energy Technology Data Exchange (ETDEWEB)

Giambo, S; Palumbo, A [Istituto di Matematica, Universita degli Studi, Messina (Italy)

1980-04-14

In the framework of the theory of the singular hypersurfaces, the transport equation for the amplitude of a discontinuity wave, corresponding to a simple characteristic of a quasi-linear hyperbolic system, is established in the context of special relativity.

On the Issue of Labor Relations Discontinuance by Staff Reduction

Directory of Open Access Journals (Sweden)

Sheveleva A. A.

2012-11-01

Full Text Available This article is devoted to consideration of issues related to the procedure of labor law contract termination by staff reduction. The author, analyzing the judicial practice, gives practical recommendations on the procedure of employment relationships discontinuance

On the relativistic transport equation for a multiple discontinuity wave

International Nuclear Information System (INIS)

Giambo, Sebastiano

1980-01-01

The theory of singular hypersurfaces is combined with the ray theory to study propagation of weak discontinuities of solutions of quasi-linear hyperbolic system in the context of special relativity. The case of a multiple wave is considered [fr

Structural, functional and evolutionary characterization of major drought transcription factors families in maize

Science.gov (United States)

Mittal, Shikha; Banduni, Pooja; Mallikarjuna, Mallana G.; Rao, Atmakuri R.; Jain, Prashant A.; Dash, Prasanta K.; Thirunavukkarasu, Nepolean

2018-05-01

Drought is one of the major threats to maize production. In order to improve the production and to breed tolerant hybrids, understanding the genes and regulatory mechanisms during drought stress is important. Transcription factors (TFs) play a major role in gene regulation and many TFs have been identified in response to drought stress. In our experiment, a set of 15 major TF families comprising 1436 genes was structurally and functionally characterized using in-silico tools and a gene expression assay. All 1436 genes were mapped on 10 chromosome of maize. The functional annotation indicated the involvement of these genes in ABA signaling, ROS scavenging, photosynthesis, stomatal regulation, and sucrose metabolism. Duplication was identified as the primary force in divergence and expansion of TF families. Phylogenetic relationship was developed individually for each TF family as well as combined TF families. Phylogenetic analysis grouped the TF family of genes into TF-specific and mixed groups. Phylogenetic analysis of genes belonging to various TF families suggested that the origin of TFs occurred in the lineage of maize evolution. Gene structure analysis revealed that more number of genes were intron-rich as compared to intronless genes. Drought-responsive CRE’s such as ABREA, ABREB, DRE1 and DRECRTCOREAT have been identified. Expression and interaction analyses identified leaf-specific bZIP TF, GRMZM2G140355, as a potential contributor toward drought tolerance in maize. We also analyzed protein-protein interaction network of 269 drought-responsive genes belonging to different drought-related TFs. The information generated on structural and functional characteristics, expression and interaction of the drought-related TF families will be useful to decipher the drought tolerance mechanisms and to derive drought-tolerant genotypes in maize.

Geotechnical applications of a two-dimensional elastodynamic displacement discontinuity method

CSIR Research Space (South Africa)

Siebrits, E

1993-12-01

Full Text Available A general two-dimensional elastodynamic displacement discontinuity method is used to model a variety of application problems. The plane strain problems are: the elastodynamic motions induced on a cavity by shear slip on a nearby crack; the dynamic...

Beyond BLASTing: Tertiary and Quaternary Structure Analysis Helps Identify Major Vault Proteins

Science.gov (United States)

Daly, Toni K.; Sutherland-Smith, Andrew J.; Penny, David

2013-01-01

We examine the advantages of going beyond sequence similarity and use both protein three-dimensional (3D) structure prediction and then quaternary structure (docking) of inferred 3D structures to help evaluate whether comparable sequences can fold into homologous structures with sufficient lateral associations for quaternary structure formation. Our test case is the major vault protein (MVP) that oligomerizes in multiple copies to form barrel-like vault particles and is relatively widespread among eukaryotes. We used the iterative threading assembly refinement server (I-TASSER) to predict whether putative MVP sequences identified by BLASTp and PSI Basic Local Alignment Search Tool are structurally similar to the experimentally determined rodent MVP tertiary structures. Then two identical predicted quaternary structures from I-TASSER are analyzed by RosettaDock to test whether a pair-wise association occurs, and hence whether the oligomeric vault complex is likely to form for a given MVP sequence. Positive controls for the method are the experimentally determined rat (Rattus norvegicus) vault X-ray crystal structure and the purple sea urchin (Strongylocentrotus purpuratus) MVP sequence that forms experimentally observed vaults. These and two kinetoplast MVP structural homologs were predicted with high confidence value, and RosettaDock predicted that these MVP sequences would dock laterally and therefore could form oligomeric vaults. As the negative control, I-TASSER did not predict an MVP-like structure from a randomized rat MVP sequence, even when constrained to the rat MVP crystal structure (PDB:2ZUO), thus further validating the method. The protocol identified six putative homologous MVP sequences in the heterobolosean Naegleria gruberi within the excavate kingdom. Two of these sequences are predicted to be structurally similar to rat MVP, despite being in excess of 300 residues shorter. The method can be used generally to help test predictions of homology via

Tensor-product preconditioners for higher-order space-time discontinuous Galerkin methods

Science.gov (United States)

Diosady, Laslo T.; Murman, Scott M.

2017-02-01

A space-time discontinuous-Galerkin spectral-element discretization is presented for direct numerical simulation of the compressible Navier-Stokes equations. An efficient solution technique based on a matrix-free Newton-Krylov method is developed in order to overcome the stiffness associated with high solution order. The use of tensor-product basis functions is key to maintaining efficiency at high-order. Efficient preconditioning methods are presented which can take advantage of the tensor-product formulation. A diagonalized Alternating-Direction-Implicit (ADI) scheme is extended to the space-time discontinuous Galerkin discretization. A new preconditioner for the compressible Euler/Navier-Stokes equations based on the fast-diagonalization method is also presented. Numerical results demonstrate the effectiveness of these preconditioners for the direct numerical simulation of subsonic turbulent flows.

Tensor-Product Preconditioners for Higher-Order Space-Time Discontinuous Galerkin Methods

Science.gov (United States)

Diosady, Laslo T.; Murman, Scott M.

2016-01-01

space-time discontinuous-Galerkin spectral-element discretization is presented for direct numerical simulation of the compressible Navier-Stokes equat ions. An efficient solution technique based on a matrix-free Newton-Krylov method is developed in order to overcome the stiffness associated with high solution order. The use of tensor-product basis functions is key to maintaining efficiency at high order. Efficient preconditioning methods are presented which can take advantage of the tensor-product formulation. A diagonalized Alternating-Direction-Implicit (ADI) scheme is extended to the space-time discontinuous Galerkin discretization. A new preconditioner for the compressible Euler/Navier-Stokes equations based on the fast-diagonalization method is also presented. Numerical results demonstrate the effectiveness of these preconditioners for the direct numerical simulation of subsonic turbulent flows.

Dynamic range majority data structures

DEFF Research Database (Denmark)

Elmasry, Amr Ahmed Abd Elmoneim; He, Meng; Munro, J. Ian

2011-01-01

Given a set P of n coloured points on the real line, we study the problem of answering range α-majority (or "heavy hitter") queries on P. More specifically, for a query range Q, we want to return each colour that is assigned to more than an α-fraction of the points contained in Q. We present a ne...

A Bayesian Nonparametric Causal Model for Regression Discontinuity Designs

Science.gov (United States)

Karabatsos, George; Walker, Stephen G.

2013-01-01

The regression discontinuity (RD) design (Thistlewaite & Campbell, 1960; Cook, 2008) provides a framework to identify and estimate causal effects from a non-randomized design. Each subject of a RD design is assigned to the treatment (versus assignment to a non-treatment) whenever her/his observed value of the assignment variable equals or…

Arcades: Products of stress-controlled and discontinuity-related weathering

Czech Academy of Sciences Publication Activity Database

Filippi, Michal; Bruthans, J.; Řihošek, J.; Slavík, M.; Adamovič, Jiří; Mašín, D.

2018-01-01

Roč. 180, May 2018 (2018), s. 159-184 ISSN 0012-8252 R&D Projects: GA ČR(CZ) GA16-19459S Institutional support: RVO:67985831 Keywords : arcades * cavernous weathering * discontinuity * granite rock stress * pillar * sandstone * stress Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 7.051, year: 2016

Linearity discontinuities in Xe-filled X-ray microstrip detectors

DEFF Research Database (Denmark)

Zavattini, G.; Feroci, M.; Budtz-Jørgensen, Carl

1997-01-01

A prototype Xe + 10% CH4 microstrip detector was used to study the K-edge discontinuity in the pulse-height distribution as a function of the energy of incident X-rays. The electronics used was such that a pulse-shape rejection could be made of K-fluorescence reabsorption in the detector. The mea...

On a problem of reconstruction of a discontinuous function by its Radon transform

Energy Technology Data Exchange (ETDEWEB)

Derevtsov, Evgeny Yu.; Maltseva, Svetlana V.; Svetov, Ivan E. [Sobolev Institute of Mathematics of SB RAS, 630090, Novosibirsk (Russian Federation); Novosibirsk State University, 630090, Novosibirsk (Russian Federation); Sultanov, Murat A. [H. A. Yassawe International Kazakh-Turkish University, 161200, Turkestan (Kazakhstan)

2016-08-10

A problem of reconstruction of a discontinuous function by its Radon transform is considered. One of the approaches to the numerical solution for the problem consists in the next sequential steps: a visualization of a set of breaking points; an identification of this set; a determination of jump values; an elimination of discontinuities. We consider three of listed problems except the problem of jump values. The problems are investigated by mathematical modeling using numerical experiments. The results of simulation are satisfactory and allow to hope for the further development of the approach.

Persistent Discontinuities in Global Software Development Teams: Adaption through Closely Coupled Work Practices

DEFF Research Database (Denmark)

Jensen, Rasmus Eskild

this as a starting point, it is clear that researchers still know little about how practitioners adjust and adapt to persistent discontinuities in globally distributed teams or how practitioners coordinate the work to bridge persistent discontinuities. Investigating the data material from an ethnographic work place...... and personal connections on several levels. These connections made the team more resistant to frequent changes in the team composition and made it easier to trace commitment in the everyday work, which was essential for completing the task. In conclusion, the dissertation found that changes...

Continuity Conditions on Schrodinger Wave Functions at Discontinuities of the Potential.

Science.gov (United States)

Branson, David

1979-01-01

Several standard arguments which attempt to show that the wave function and its derivative must be continuous across jump discontinuities of the potential are reviewed and their defects discussed. (Author/HM)

Characteristics of switched reluctance motor operating in continuous and discontinuous conduction mode

Directory of Open Access Journals (Sweden)

Ćalasan Martin P.

2013-01-01

Full Text Available This paper presents mechanical characteristics of Switched Reluctance Motor (SRM when it operates in Discontinuous Conduction Mode (DCM or in Continuous Conduction Mode (CCM, i.e. when the current through the phase coils (windings flows discontinuously or continuously. Firstly, in order to maximize the output power of SRM optimization of its control parameters was performed, such that the peak and RMS values of the current do not exceed the predefined values. The optimal control parameters vs. rotation speed, as well as the corresponding characteristics of torque, power and efficiency. It is shown that with CCM the machine torque (power, at high speed, can be increased.

Shock discontinuities around the confinement-deconfinement transition in baryon-rich dense matter

International Nuclear Information System (INIS)

Rischke, D.H.; Waldhauser, B.M.; Stoecker, H.; Greiner, W.; Friman, B.L.

1989-05-01

We investigate shock discontinuities that involve a conversion of hadronic matter into quark-gluon matter and vice versa. Such discontinuities may develop when nuclear matter is compressed to energy densities beyond the deconfinement transition and in the hadronization of an expanding quark-gluon plasma. In these investigations we study the influence of various phenomenological equations of state. Consequences for entropy production in heavy-ion collisions are discussed and estimates of inclusive particle ratios at freeze-out are given. We find that antiparticle-to-particle ratios may be enhanced by an order of magnitude if a quark-gluon plasma is created during the collision compared to a purely hadronic collision scenario. (orig.)

78 FR 73585 - Missouri Central Railroad Company-Discontinuance of Trackage Rights Exemption-in Cass and Jackson...

Science.gov (United States)

2013-12-06

... F--Exempt Abandonments and Discontinuances of Service to discontinue trackage rights over a rail... be a common carrier authorized to operate on the Line. MCRR and CMR have certified that: (1) MCRR and... be rerouted over other lines; (3) no formal complaint filed by a user of rail service on the Line (or...

Outcomes Following Discontinuation of E. coli l-Asparaginase Upon Severe Allergic Reactions in Children With Acute Lymphoblastic Leukemia.

Science.gov (United States)

Yen, Hsiu-Ju; Chang, Wan-Hui; Liu, Hsi-Che; Yeh, Ting-Chi; Hung, Giun-Yi; Wu, Kang-Hsi; Peng, Ching-Tien; Chang, Yu-Hsiang; Chang, Te-Kao; Hsiao, Chih-Cheng; Sheen, Jiunn-Ming; Chao, Yu-Hua; Chang, Tai-Tsung; Chiou, Shyh-Shin; Lin, Pei-Chin; Wang, Shih-Chung; Lin, Ming-Tsan; Ho, Wan-Ling; Chen, Yu-Chieh; Liang, Der-Cherng

2016-04-01

Discontinuation of E. coli l-asparaginase in patients with acute lymphoblastic leukemia (ALL) is unavoidable upon severe allergic reaction. We sought to examine outcomes following E. coli l-asparaginase discontinuation due to severe allergic reactions. We evaluated the outcome of children enrolled in Taiwan Pediatric Oncology Group-2002-ALL protocol between 2002 and 2012, who had E. coli l-asparaginase discontinued due to severe allergic reactions, and compared the outcomes of those who continued with Erwinia l-asparaginase (Erwinase) with those who did not. Among 700 patients enrolled in this study, 33 patients had E. coli l-asparaginase treatment discontinued due to severe allergic reactions. Five-year overall survival did not differ significantly among the 648 patients without discontinuation (81 ± 1.6%, mean ± SE), compared to 17 patients with allergic reactions and treated with Erwinase (88 ± 7.8%) and 16 patients with allergic reactions but not treated with Erwinase (87 ± 8.6%). Among 16 patients who did not receive Erwinase, all 10 who received ≥50% of the scheduled doses of E. coli l-asparaginase before discontinuation survived without events. Erwinase treatment may not be needed for some ALL patients with severe allergy to E. coli l-asparaginase if ≥50% of prescribed doses were received and/or therapy is augmented with other agents. © 2015 Wiley Periodicals, Inc.

A New Generalized Discontinuous-PWM Strategy for Active Power Filters

DEFF Research Database (Denmark)

Asiminoaei, Lucian; Rodriguez, Pedro; Blaabjerg, Frede

2007-01-01

losses in any operating point. This paper proposes a new discontinuous pulse width modulation strategy applied to shunt active power filters. The proposed modulation strategy detects the current vector position relative to the inverter voltage reference and determines instantaneously the optimum clamped...

Thyroid function in children and adolescents with Hashimoto’s thyroiditis after l-thyroxine discontinuation

Directory of Open Access Journals (Sweden)

Giorgio Radetti

2017-04-01

Full Text Available Objective: Thyroid function may recover in patients with Hashimoto’s thyroiditis (HT. Design: To investigate thyroid function and the need to resume l-thyroxine treatment after its discontinuation. Setting: Nine Italian pediatric endocrinology centers. Patients: 148 children and adolescents (25 m and 123 f with HT on treatment with l-thyroxine for at least one year. Intervention and main outcome measure: Treatment was discontinued in all patients, and serum TSH and fT4 concentrations were measured at the time of treatment discontinuation and then after 2, 6, 12 and 24 months. Therapy with l-thyroxine was re-instituted when TSH rose >10 U/L and/or fT4 was below the normal range. The patients were followed up when TSH concentrations were between 5 and 10 U/L and fT4 was in the normal range. Results: At baseline, TSH was in the normal range in 139 patients, and was between 5 and 10 U/L in 9 patients. Treatment was re-instituted after 2 months in 37 (25.5% patients, after 6 months in 13 patients (6.99%, after 12 months in 12 patients (8.6%, and after 24 months in an additional 3 patients (3.1%. At 24 months, 34 patients (34.3% still required no treatment. TSH concentration >10 U/L at the time of diagnosis was the only predictive factor for the deterioration of thyroid function after l-thyroxine discontinuation. Conclusions: This study confirms that not all children with HT need life-long therapy with l-thyroxine, and the discontinuation of treatment in patients with a TSH level <10 U/L at the time of diagnosis should be considered.

Discontinuous Sturm-Liouville Problems with Eigenvalue Dependent Boundary Condition

Energy Technology Data Exchange (ETDEWEB)

Amirov, R. Kh., E-mail: emirov@cumhuriyet.edu.tr; Ozkan, A. S., E-mail: sozkan@cumhuriyet.edu.tr [Cumhuriyet University, Department of Mathematics Faculty of Art and Science (Turkey)

2014-12-15

In this study, an inverse problem for Sturm-Liouville differential operators with discontinuities is studied when an eigenparameter appears not only in the differential equation but it also appears in the boundary condition. Uniqueness theorems of inverse problems according to the Prüfer angle, the Weyl function and two different eigenvalues sets are proved.

Benefits and harms in clinical trials of duloxetine for treatment of major depressive disorder

DEFF Research Database (Denmark)

Maund, Emma; Tendal, Britta; Hróbjartsson, Asbjørn

2014-01-01

, with respect to benefits and major harms. DESIGN: Data on primary efficacy analysis and major harms extracted from each data source and compared. SETTING: Nine randomised placebo controlled trials of duloxetine (total 2878 patients) submitted to the European Medicines Agency (EMA) for marketing approval.......gov and the manufacturer's online clinical trial registry were searched for trial results. RESULTS: Clinical study reports fully described the primary efficacy analysis and major harms (deaths (including suicides), suicide attempts, serious adverse events, and discontinuations because of adverse events). There were minor......, respectively. We also found publication bias in relation to beneficial effects. CONCLUSION: Clinical study reports contained extensive data on major harms that were unavailable in journal articles and in trial registry reports. There were inconsistencies between protocols and clinical study reports and within...

Topography of upper mantle seismic discontinuities beneath the North Atlantic: the Azores, Canary and Cape Verde plumes