WorldWideScience

Sample records for modeling suspected potential

  1. Suspected radioactive contamination: evaluation of 45 Israeli citizens potentially exposed to polonium-210 in London.

    Science.gov (United States)

    Brosh-Nissimov, Tal; Havkin, Ofra; Davidovitch, Nadav; Poles, Lion; Shapira, Chen

    2008-02-01

    The lethal poisoning of Alexander Litvinenco with the radioactive element polonium-210, and the risk that many civilians (including Israeli citizens) who were in the same location in London at the same time were exposed to radiation, was an unprecedented event in the western world. This was only the second known death due to 210Po, a natural alpha radiation-emitting element. A task team was created to handle the event. The team comprised representatives from the Ministry of Health's advisory committee for radiological events (which includes the Israel Defense Force, the Israeli Atomic Energy Commission and the Ministry of Environmental Protection), the Public Health Services Central District, and a public relations expert. Forty-seven people were located and underwent an epidemiological inquiry, and urine samples for detection of 210Po were sent abroad to a specialized laboratory. The radiotoxicological results were analyzed and evaluated by the expert team and follow-up recommendations were made. This unfamiliar and potentially stressful scenario was handled successfully by a multi-organizational multidisciplinary task team. The joint work of the task team was a real-life "exercise" simulating a radiological event in Israel. This team has recommended further evaluation of various vital missions in the event of any possible future radiological event, with special emphasis on a proactive communication approach to the media and the public.

  2. Frequency-doubling technology perimetry and multifocal visual evoked potential in glaucoma, suspected glaucoma, and control patients

    Directory of Open Access Journals (Sweden)

    Kanadani FN

    2014-07-01

    Full Text Available Fabio N Kanadani,1 Paulo AA Mello,1 Syril K Dorairaj,2 Tereza CM Kanadani31Federal University of Sao Paulo, Sao Paulo, Brazil; 2Mayo Clinic, Department of Ophthalmology, Jacksonville, Florida, USA; 3Sao Jose University Hospital, Belo Horizonte, BrazilIntroduction: The gold standard in functional glaucoma evaluation is standard automated perimetry (SAP. However, SAP depends on the reliability of the patients’ responses and other external factors; therefore, other technologies have been developed for earlier detection of visual field changes in glaucoma patients. The frequency-doubling perimetry (FDT is believed to detect glaucoma earlier than SAP. The multifocal visual evoked potential (mfVEP is an objective test for functional evaluation.Objective: To evaluate the sensitivity and specificity of FDT and mfVEP tests in normal, suspect, and glaucomatous eyes and compare the monocular and interocuar mf VEP.Methods: Ninety-five eyes from 95 individuals (23 controls, 33 glaucoma suspects, 39 glaucomatous were enrolled. All participants underwent a full ophthalmic examination, followed by SAP, FDT, and mfVEP tests. Results: The area under the curve for mean deviation and pattern standard deviation were 0.756 and 0.761, respectively, for FDT, 0.564 and 0.512 for signal and alpha for interocular mfVEP, and 0.568 and 0.538 for signal and alpha for monocular mfVEP. This difference between monocular and interocular mfVEP was not significant. Conclusion: The FDT matrix was superior to mfVEP in glaucoma detection. The difference between monocular and interocular mfVEP in the diagnosis of glaucoma was not significant. Keywords: standard automated perimetry, electrophysiology, glaucomatous eyes

  3. Rapid Screening for Exposure to "Non-Target" Pharmaceuticals from Wastewater Effluents by Combining HRMS-Based Suspect Screening and Exposure Modeling.

    Science.gov (United States)

    Singer, Heinz P; Wössner, Annika E; McArdell, Christa S; Fenner, Kathrin

    2016-07-01

    Active pharmaceutical ingredients (APIs) have raised considerable concern over the past decade due to their widespread detection in water resources and their potential to affect ecosystem health. This triggered many attempts to prioritize the large number of known APIs to target monitoring efforts and testing of fate and effects. However, so far, a comprehensive approach to screen for their presence in surface waters has been missing. Here, we explore a combination of an automated suspect screening approach based on liquid chromatography coupled to high-resolution mass spectrometry and a model-based prioritization using consumption data, readily predictable fate properties and a generic mass balance model for activated sludge treatment to comprehensively detect APIs with relevant exposure in wastewater treatment plant effluents. The procedure afforded the detection of 27 APIs that had not been covered in our previous target method, which included 119 parent APIs. The newly detected APIs included seven compounds with a high potential for bioaccumulation and persistence, and also three compounds that were suspected to stem from point sources rather than from consumption as medicines. Analytical suspect screening proved to be more selective than model-based prioritization, making it the method of choice for focusing analytical method development or fate and effect testing on those APIs most relevant to the aquatic environment. However, we found that state-of-the-practice exposure modeling used to predict potential high-exposure substances can be a useful complement to point toward oversights and known or suspected detection gaps in the analytical method, most of which were related to insufficient ionization.

  4. Spooky Suspects

    Science.gov (United States)

    Pacifici, Lara

    2011-01-01

    This activity presents an option for covering biology content while engaging students in an investigation that highlights the spirit of Halloween. Students are engaged in the story line and have fun trying to solve the mystery kidnapping by using science skills to examine the evidence and eliminate some ghoulish suspects. (Contains 1 figure.)

  5. Cross-reactions in IgM ELISA tests to Legionella pneumophila sg1 and Bordetella pertussis among children suspected of legionellosis; potential impact of vaccination against pertussis?

    Science.gov (United States)

    Pancer, Katarzyna Wanda

    2015-01-01

    The objective of this study was preliminary evaluation of IgM cross-reaction in sera collected from children hospitalized because of suspected legionellosis. Sera with positive IgM results to L. pneumophila sgs1-7, B. pertussis or with simultaneous detection of IgM antibodies to L. pneumophila sgs1-7 and B. pertussis, or IgM to L. pneumophila sgs1-7 and M. pneumoniae in routine tests, were selected. In total, an adapted pre-absorption test was used for the serological confirmation of legionellosis in the sera of 19 children suspected of legionellosis, and also in 3 adult persons with confirmed Legionnaires' disease. Sera were pre-absorbed with antigens of L. pneumophila sg1, B. pertussis or both, and tested by ELISA tests. The reduction of IgM antibody level by pre-absorption with antigen/antigens was determined. Reduction of anti-Lpsgs1-7 IgM by pre-absorption with L.pneumophila sg1 antigen ranged from 1.5 to 80, and reduction of anti-Bp IgM by pre-absorption with B. pertussis ranged from 2.0 to 23.8. Reduction by both antigens varied depending on the age of the patients: among children tests. As a preliminary, we posed a hypothesis of a potential impact of an anti-pertussis vaccination on the results obtained in anti-L. pneumophila ELISA IgM tests among young children.

  6. Risk model for suspected acute coronary syndrome is of limited value in an emergency department

    DEFF Research Database (Denmark)

    Mogensen, Christian Backer; Christiansen, Maja; Jørgensen, Jess Bjerre

    2015-01-01

    INTRODUCTION: Among patients with acute chest pain, acute coronary syndrome (ACS) is seen only in a minority of the patients, which raises the question, whether it is possible to separate a group with a high risk of ACS for admission to a cardiac care unit (CCU) from those with a low risk who would...... be treated at an emergency department (ED). The aim of this study was to describe a risk stratification model for a Danish context. METHODS: This was a historic prospective cohort study of patients with suspicion of ACS. The patient was defined as a low-risk patient and admitted to the ED if: 1...

  7. Modeling the clinical assessment of men with suspected obstructed voiding using Bayes' Theorem.

    Science.gov (United States)

    Caffarel, Jennifer; Griffiths, Clive; Pickard, Robert; Robson, Wendy; Drinnan, Michael

    2008-01-01

    Pressure-flow studies (PFS) are the only reliable way to diagnose bladder outlet obstruction (BOO) in men with lower urinary tract symptoms (LUTS). However, in routine clinical practice, BOO is usually inferred by any of a number of tests (symptoms, flow rate, prostate size...). Bayes' Theorem provides a mathematical method, which may be similar to the process used by clinicians, for combining the results of multiple tests to reach a diagnosis. We have applied Bayes' Theorem to the results of several tests known weakly to predict BOO in men with LUTS to assess if they improve the diagnostic accuracy of a flow rate test which alone is known to predict obstruction moderately well. We applied Bayes' Theorem to data from 50 patients using Q(max) alone and with the inclusion of additional variables (IPSS, PSA, and residual urine), to establish individual probabilities of BOO. The chi-squared statistic (with trend) was used to compare the relative diagnostic values, against the BOO index calculated from the results of subsequent PFS. The diagnostic value of Q(max) alone (chi-squared = 9.2, P = 0.002), was superior than that for the Bayesian model using the combination of tests available (chi-squared = 4.9, P = 0.026). Although in our sample relevant additional tests do not improve the diagnostic power of Q(max) as a predictor of BOO, we believe the Bayesian approach is conceptually suited to modeling clinical decision making but may be better tested for a more clinically relevant outcome such as treatment response. (c) 2008 Wiley-Liss, Inc.

  8. Investigation of a measles outbreak in Zimbabwe, 2010: potential of a point of care test to replace laboratory confirmation of suspected cases.

    Science.gov (United States)

    Shonhai, A; Warrener, L; Mangwanya, D; Slibinskas, R; Brown, K; Brown, D; Featherstone, D; Samuel, D

    2015-12-01

    Blood and oral fluid (OF) samples were collected from 103 suspected measles cases between February and November 2010 during a nationwide measles outbreak in Zimbabwe. Siemens measles IgM enzyme immunoassay (EIA) on serum, Microimmune measles IgM capture EIA on OF, real-time haemagglutinin (H) gene PCR and nested nucleocapsid (N) gene PCR on OF were performed, confirming 75 measles cases. These samples were then used to evaluate a newly developed point of care test (POCT) for measles and determine its potential for identifying measles cases in outbreaks. After performing POCTs on OF samples, nucleic acid was extracted from the used test strips and the measles H and N genes amplified by RT-PCR. The sensitivity, specificity, positive and negative predictive values of the POCT for IgM in OF was 75·0% [95% confidence interval (CI) 63·4-84·5], 96·2% (95% CI 80·4-99·9), 98·2% (95% CI 90·3-100) and 58·1% (95% CI 42·1-73·0), respectively. The N gene sequences showed high level of agreement between original OF and corresponding POCT strips. Measles genotype B3 was identified in all cases. We conclude that the measles POCT has the potential to be used, at the point of contact, in outbreak situations and provide molecular characterization of the virus at a later date.

  9. Predictive modeling for diagnostic tests with high specificity, but low sensitivity: a study of the glycerol test in patients with suspected Meniere's disease.

    Directory of Open Access Journals (Sweden)

    Bernd Lütkenhöner

    Full Text Available A high specificity does not ensure that the expected benefit of a diagnostic test outweighs its cost. Problems arise, in particular, when the investigation is expensive, the prevalence of a positive test result is relatively small for the candidate patients, and the sensitivity of the test is low so that the information provided by a negative result is virtually negligible. The consequence may be that a potentially useful test does not gain broader acceptance. Here we show how predictive modeling can help to identify patients for whom the ratio of expected benefit and cost reaches an acceptable level so that testing these patients is reasonable even though testing all patients might be considered wasteful. Our application example is based on a retrospective study of the glycerol test, which is used to corroborate a suspected diagnosis of Menière's disease. Using the pretest hearing thresholds at up to 10 frequencies, predictions were made by K-nearest neighbor classification or logistic regression. Both methods estimate, based on results from previous patients, the posterior probability that performing the considered test in a new patient will have a positive outcome. The quality of the prediction was evaluated using leave-one-out cross-validation, making various assumptions about the costs and benefits of testing. With reference to all 356 cases, the probability of a positive test result was almost 0.4. For subpopulations selected by K-nearest neighbor classification, which was clearly superior to logistic regression, this probability could be increased up to about 0.6. Thus, the odds of a positive test result were more than doubled.

  10. [Exercise tests in unstable angina suspects].

    Science.gov (United States)

    2012-01-01

    The review is devoted to exercise tests (ET) potential in patients with different forms of coronary heart disease (CHD) exacerbation and suspected unstable angina. It is well known that unstable angina untreated pharmacologically is a contraindication for ET. Of interest in clinical practice is diagnosis, risk assessment and treatment policy in patients with chest pain. The main focus is on ET conduction in unstable angina suspects with low and intermediate risk, on safety and validity of ET conduction in these patients.

  11. The usual suspects-influence of physicochemical properties on lag time, skin deposition, and percutaneous penetration of nine model compounds

    DEFF Research Database (Denmark)

    Bo Nielsen, Jesper; Sørensen, Jens Ahm; Nielsen, Flemming

    2009-01-01

    for Economic Cooperation and Development (OECD) guidelines. The model compounds were chosen to cover a wide spectrum of solubilities and molecular weights. The pesticides included were glyphosate, dimethoate, pirimicarb, malathion, paclobutrazol, methiocarb, prochloraz, and benzoic acid, with the ninth model...

  12. Potential Crash Location (PCL) Model

    Science.gov (United States)

    2014-02-05

    LCA ) model provides a method for calculating how large the actual lethal area at the site of impact would be. The LCA model is described in a...helicopter failures. The crash location calculations are just one portion of the TLS tool, the other portion is LCA . Although the LCA is not

  13. Bioluminescence Potential Modeling and Forecasting

    Science.gov (United States)

    2013-05-22

    bioluminescence in the wakes of ships, breaking waves, around the bodies of rapidly moving fish and mammals , and from simple agitation of the water with one’s hand...history of brilliant displays of bioluminescence in the wakes of ships, breaking waves, around the bodies of rapidly moving fish and mammals , and from...during the earlier stages of upwelling development. Later, the observed deep offshore BL potential maximum disappeared and became a shallower and much

  14. A predictive model to identify patients with suspected acute coronary syndromes at high risk of cardiac arrest or in-hospital mortality: An IMMEDIATE Trial sub-study

    Directory of Open Access Journals (Sweden)

    Madhab Ray

    2015-12-01

    Conclusions: The multivariable predictive model developed identified patients with very early ACS at high risk of cardiac arrest or death. Using this model could assist treating those with greatest potential benefit from GIK.

  15. Model Potentials for a C60 Shell

    CERN Document Server

    Manson, S T; Msezane, A Z

    2016-01-01

    The spatial distribution of electric charges forming a square well potential has been analyzed. It is shown that this potential is created by two concentric spheres with a double layer of charges. A C60 shell potential has been calculated under the assumption that it is formed by the averaged charge density of a neutral atom. It is further demonstrated that the phenomenological potentials simulating the C60 shell potential belong to a family of potentials with a non-flat bottom. Two possible types of C60 model potentials are proposed and their parameters have been calculated. AMS (MOS) Subject Classification. 62P35, 81V55

  16. Smooth models for the Coulomb potential

    CERN Document Server

    González-Espinoza, Cristina E; Karwowski, Jacek; Savin, Andreas

    2016-01-01

    Smooth model potentials with parameters selected to reproduce the spectrum of one-electron atoms are used to approximate the singular Coulomb potential. Even when the potentials do not mimic the Coulomb singularity, much of the spectrum is reproduced within the chemical accuracy. For the Hydrogen atom, the smooth approximations to the Coulomb potential are more accurate for higher angular momentum states. The transferability of the model potentials from an attractive interaction (Hydrogen atom) to a repulsive one (Harmonium and the uniform electron gas) is discussed.

  17. A Potential Model for Cylindrical Pores

    Institute of Scientific and Technical Information of China (English)

    张现仁; 汪文川

    2001-01-01

    An analytical potential for cylindrical pores has been derived by introducing a variational method into the integration for the calculation of the interaction energy between the wall molecules and a test molecule, all of which are represented by Lennard-Jones potential. The model proposed gives good fit to the results from the cylindrical surface model and the pseudoatom model. To test the potential proposed rigorously, we have carried out grand canonical ensemble Monte Carlo(GCMC) simulation of nitrogen in the MCM-41 pore at 77 K, and compared the simulated adsorption isotherm with the experimental data reported in the literature. The simulated isotherm from our model is in almost qualitative agreement with experiment. Consequently, the model proposed provides an explicit and accurate description of cylindrical pores represented by the Lennard-Jones potential. Moreover, the model can be easily applied to a variety of cylindrical pores, ranging from cylindrical surface to finite thickness walls, in both theoretical studies and computer simulations.

  18. Baby Skyrme models without a potential term

    CERN Document Server

    Ashcroft, Jennifer; Krusch, Steffen

    2015-01-01

    We develop a one-parameter family of static baby Skyrme models that do not require a potential term to admit topological solitons. This is a novel property as all currently known baby Skyrme models must contain a potential term in order to have stable soliton solutions, though the Skyrme model does not require this. Our new models satisfy an energy bound that is linear in terms of the topological charge and can be saturated in an extreme limit. They also satisfy a virial theorem that is shared by the Skyrme model. We calculate the solitons of our new models numerically and observe that their form depends significantly on the choice of parameter. In one extreme, we find compactons whilst at the other there is a scale invariant model in which solitons can be obtained exactly as solutions to a Bogomolny equation. We provide an initial investigation into these solitons and compare them with the baby Skyrmions of other models.

  19. Potential Models for Radiative Rare B Decays

    CERN Document Server

    Ahmad, S

    2002-01-01

    We compute the branching ratios for the radiative rare decays of B into K-Meson states and compare them to the experimentally determined branching ratio for inclusive decay b -> s gamma using non relativistic quark model, and form factor definitions consistent with HQET covariant trace formalism. Such calculations necessarily involve a potential model. In order to test the sensitivity of calculations to potential models we have used three different potentials, namely linear potential, screening confining potential and heavy quark potential as it stands in QCD.We find the branching ratios relative to the inclusive b ->s gamma decay to be (16.07\\pm 5.2)% for B -> K^* (892)gamma and (7.25\\pm 3.2)% for B -> K_2^* (1430)gamma for linear potential. In the case of the screening confining potential these values are (19.75\\pm 5.3)% and (4.74\\pm 1.2)% while those for the heavy quark potential are (11.18\\pm 4.6)% and (5.09\\pm 2.7)% respectively. All these values are consistent with the corresponding present CLEO experim...

  20. The Folding Deuteron Optical Model Potentials

    CERN Document Server

    Li, Xiaohua; Cai, Chonghai

    2008-01-01

    For 52 target nuclei with deuteron as projectile, we calculate the reaction cross sections and elastic scattering angular distributions, as well as the $\\chi^2$ values for 11 kinds of deuteron optical model potentials: our global deuteron optical potentials and 10 folding optical potentials calculated with 2 phenomenological global nucleon optical potentials given by Koning \\textit{et al}(KD) and by Varner\\textit{et al}(CH89), and 8 microscopic nucleon optical potentials with the generalized Skyrme force parameters(GS1-6) and modified Skyrme force parameters(SKa, SKb). We find that for constructing the folding deuteron optical potential, both SKa and SKb are the best Skyrme force parameters of the microscopic nucleon optical potential proposed by Q. Shen \\textit{et al}.

  1. Mineral potential mapping with mathematical geological models

    NARCIS (Netherlands)

    Porwal, A.K.

    2006-01-01

    Mathematical geological models are being increasingly used by natural resources delineation and planning agencies for mapping areas of mineral potential in order to optimize land use in accordance with socio-economic needs of the society. However, a key problem in spatial-mathematical-model-based mi

  2. Mineral potential mapping with mathematical geological models

    NARCIS (Netherlands)

    Porwal, A.K.

    2006-01-01

    Mathematical geological models are being increasingly used by natural resources delineation and planning agencies for mapping areas of mineral potential in order to optimize land use in accordance with socio-economic needs of the society. However, a key problem in spatial-mathematical-model-based

  3. Modeling Rotating Turbulent Flows with the Body Force Potential Model.

    Science.gov (United States)

    Bhattacharya, Amitabh; Perot, Blair

    2000-11-01

    Like a Reynolds Stress Transport equation model, the turbulent potential model has an explicit Coriolis acceleration term that appears in the model that accounts for rotation effects. In this work the additional secondary effects that system rotation has on the dissipation rate, return-to-isotropy, and fast pressure strain terms are also included in the model. The resulting model is tested in the context of rotating isotropic turbulence, rotating homogeneous shear flow, rotating channel flow, and swirling pipe flow. Many of the model changes are applicable to Reynolds stress transport equation models. All model modifications are frame indifferent.

  4. Analytic Models of Plausible Gravitational Lens Potentials

    Energy Technology Data Exchange (ETDEWEB)

    Baltz, Edward A.; Marshall, Phil; Oguri, Masamune

    2007-05-04

    Gravitational lenses on galaxy scales are plausibly modeled as having ellipsoidal symmetry and a universal dark matter density profile, with a Sersic profile to describe the distribution of baryonic matter. Predicting all lensing effects requires knowledge of the total lens potential: in this work we give analytic forms for that of the above hybrid model. Emphasizing that complex lens potentials can be constructed from simpler components in linear combination, we provide a recipe for attaining elliptical symmetry in either projected mass or lens potential.We also provide analytic formulae for the lens potentials of Sersic profiles for integer and half-integer index. We then present formulae describing the gravitational lensing effects due to smoothly-truncated universal density profiles in cold dark matter model. For our isolated haloes the density profile falls off as radius to the minus fifth or seventh power beyond the tidal radius, functional forms that allow all orders of lens potential derivatives to be calculated analytically, while ensuring a non-divergent total mass. We show how the observables predicted by this profile differ from that of the original infinite-mass NFW profile. Expressions for the gravitational flexion are highlighted. We show how decreasing the tidal radius allows stripped haloes to be modeled, providing a framework for a fuller investigation of dark matter substructure in galaxies and clusters. Finally we remark on the need for finite mass halo profiles when doing cosmological ray-tracing simulations, and the need for readily-calculable higher order derivatives of the lens potential when studying catastrophes in strong lenses.

  5. Transient accelerating scalar models with exponential potentials

    Institute of Scientific and Technical Information of China (English)

    Wen-Ping Cui; Yang Zhang; Zheng-Wen Fu

    2013-01-01

    We study a known class of scalar dark energy models in which the potential has an exponential term and the current accelerating era is transient.We find that,although a decelerating era will return in the future,when extrapolating the model back to earlier stages (z(≥) 4),scalar dark energy becomes dominant over matter.So these models do not have the desired tracking behavior,and the predicted transient period of acceleration cannot be adopted into the standard scenario of the Big Bang cosmology.When couplings between the scalar field and matter are introduced,the models still have the same problem; only the time when deceleration returns will be varied.To achieve re-deceleration,one has to turn to alternative models that are consistent with the standard Big Bang scenario.

  6. Modeling auditory evoked potentials to complex stimuli

    DEFF Research Database (Denmark)

    Rønne, Filip Munch

    The auditory evoked potential (AEP) is an electrical signal that can be recorded from electrodes attached to the scalp of a human subject when a sound is presented. The signal is considered to reflect neural activity in response to the acoustic stimulation and is a well established clinical...... clinically and in research towards using realistic and complex stimuli, such as speech, to electrophysiologically assess the human hearing. However, to interpret the AEP generation to complex sounds, the potential patterns in response to simple stimuli needs to be understood. Therefore, the model was used...... to simulate auditory brainstem responses (ABRs) evoked by classic stimuli like clicks, tone bursts and chirps. The ABRs to these simple stimuli were compared to literature data and the model was shown to predict the frequency dependence of tone-burst ABR wave-V latency and the level-dependence of ABR wave...

  7. B Plant/WESF suspect/counterfeit parts identification program

    Energy Technology Data Exchange (ETDEWEB)

    Mertz, D.W.

    1996-01-12

    This document describes a suspect/counterfeit parts inspection program required by DOE conducted in accordance with Internal Memo 16710-94-DWM-048, J.A. O`Brien to J. N. Nansen, B Plant Suspect/ Counterfeit Parts Action Plan, dated May 24, 1994. The program included: physical inspection of all spare parts inventories within the plant; screening of installed B Plant/WESF (Waste Encapsulation and Storage Facility) systems for applications where the use and subsequent potential failure of suspect/counterfeit parts could have critical consequences; and a physical inspection based upon this screening.

  8. Case Report and Management of Suspected Acute Appendicitis in Pregnancy

    OpenAIRE

    Murariu, Daniel; Tatsuno, Brent; Hirai, Cori-Ann M; Takamori, Ryan

    2011-01-01

    Suspected cases of acute appendicitis in pregnancy are considered surgical emergencies due to the potentially devastating outcomes for both mother and unborn child if the appendix perforates. Acute appendicitis is also the number one cause of non-traumatic acute abdomen in pregnancy, as well as the number one cause of fetal death. We present a case report with a typical presentation of suspected acute appendicitis in a pregnant woman. The work up and diagnostic tools available are discussed a...

  9. Electrostatic potential map modelling with COSY Infinity

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, J.A., E-mail: maloneyja@triumf.ca; Baartman, R.; Planche, T.; Saminathan, S.

    2016-06-01

    COSY Infinity (Makino and Berz, 2005) is a differential-algebra based simulation code which allows accurate calculation of transfer maps to arbitrary order. COSY’s existing internal procedures were modified to allow electrostatic elements to be specified using an array of field potential data from the midplane. Additionally, a new procedure was created allowing electrostatic elements and their fringe fields to be specified by an analytic function. This allows greater flexibility in accurately modelling electrostatic elements and their fringe fields. Applied examples of these new procedures are presented including the modelling of a shunted electrostatic multipole designed with OPERA, a spherical electrostatic bender, and the effects of different shaped apertures in an electrostatic beam line.

  10. Electrostatic potential map modelling with COSY Infinity

    Science.gov (United States)

    Maloney, J. A.; Baartman, R.; Planche, T.; Saminathan, S.

    2016-06-01

    COSY Infinity (Makino and Berz, 2005) is a differential-algebra based simulation code which allows accurate calculation of transfer maps to arbitrary order. COSY's existing internal procedures were modified to allow electrostatic elements to be specified using an array of field potential data from the midplane. Additionally, a new procedure was created allowing electrostatic elements and their fringe fields to be specified by an analytic function. This allows greater flexibility in accurately modelling electrostatic elements and their fringe fields. Applied examples of these new procedures are presented including the modelling of a shunted electrostatic multipole designed with OPERA, a spherical electrostatic bender, and the effects of different shaped apertures in an electrostatic beam line.

  11. When to Suspect Occupational Asthma

    Directory of Open Access Journals (Sweden)

    Catherine Lemière

    2013-01-01

    Full Text Available Occupational asthma (OA is a difficult diagnosis to make. The present review describes the work environments in which workers are at risk for developing OA, the characteristics of the individuals in whom OA should be suspected and the investigation that can be performed to diagnose the condition. Accurately diagnosing OA is crucial because of the major social and economic consequences of this diagnosis on the patient.

  12. Exposomics research using suspect screening and non ...

    Science.gov (United States)

    High-resolution mass spectrometry (HRMS) is used for suspect screening (SSA) and non-targeted analysis (NTA) in an attempt to characterize xenobiotic chemicals in various samples broadly and efficiently. These important techniques aid characterization of the exposome, the totality of human exposures, and provide critical information on thousands of chemicals in commerce for which exposure data are lacking. The Environmental Protection Agency (EPA) SSA and NTA capabilities consist of analytical instrumentation [liquid chromatography (LC) with time of flight (TOF) and quadrupole-TOF (Q-TOF) HRMS], workflows (feature extraction, formula generation, structure prediction, spectral matching, chemical confirmation), and tools (databases; models for predicting retention time, functional use, media occurrence, and media concentration; and schemes for ranking features and chemicals). Suspect screening (SSA) and non-targeted analysis (NTA) are used to characterize xenobiotic chemicals in various samples and aid characterization of the exposome, the totality of human exposures, and provide critical information on thousands of chemicals in commerce for which exposure data are lacking.

  13. Complexification of three potential models – II

    Indian Academy of Sciences (India)

    Sanjib Meyur; S Dednath

    2009-10-01

    A new kind of $\\mathcal{PT}$ and non-$\\mathcal{PT}$-symmetric complex potentials are constructed from a group theoretical viewpoint of the sl(2, ) potential algebras. The real eigenvalues and the corresponding regular eigenfunctions are also obtained. The results are compared with the ones obtained before.

  14. Maternal psychosocial predictors of pediatric health care use: Use of the common sense model of health and illness behaviors to extend beyond the usual suspects.

    Science.gov (United States)

    Moran, Tracy E; O'Hara, Michael W

    2006-01-01

    Determinants of pediatric health care use extend beyond the health status of the child and economic and access considerations. Parental factors, particularly those associated with the mother, are critical. The common sense model of health and illness behaviors, which was developed to account for adult health care use, may constitute a framework to study the role of mothers in determining pediatric health care use. In the common sense model, the person's cognitive representations of and affective reactions to bodily states influence health care decision-making. There is a growing literature that points to the importance of maternal psychopathology (reflecting the affective component of the common sense model) and maternal parenting self-efficacy (reflecting the cognitive component of the model) as important contributors to pediatric health care use. The implications of this conceptualization for future research and clinical practice are discussed.

  15. Case report and management of suspected acute appendicitis in pregnancy.

    Science.gov (United States)

    Murariu, Daniel; Tatsuno, Brent; Hirai, Cori-Ann M; Takamori, Ryan

    2011-02-01

    Suspected cases of acute appendicitis in pregnancy are considered surgical emergencies due to the potentially devastating outcomes for both mother and unborn child if the appendix perforates. Acute appendicitis is also the number one cause of non-traumatic acute abdomen in pregnancy, as well as the number one cause of fetal death. We present a case report with a typical presentation of suspected acute appendicitis in a pregnant woman. The work up and diagnostic tools available are discussed at length, as well as the finer points in treatment of this population.

  16. Altitudinal variation and bio-climatic variables influencing the potential distribution of Culicoides orientalis Macfie, 1932, suspected vector of Bluetongue virus across the North Eastern Himalayan belt of Sikkim.

    Science.gov (United States)

    Mukhopadhyay, Emon; Hazra, Surajit; Saha, Goutam Kumar; Banerjee, Dhriti

    2017-09-19

    Culicoides orientalis was first recorded from Sikkim, in the year 1963, but no evidence based disease outbreak were available. In the last 50 years, 260 Bluetongue disease outbreaks caused by Culicoides species have been evidenced from India. Moreover, in recent years with increase of average temperature worldwide and increase in longevity of arthropod vectors like Culicoides along with a geographical range shift to new suitable warmer regions has increased the potentiality of vector borne disease outbreak throughout the world. The Himalayan range of Sikkim in India is a biodiversity hotspot and is extremely sensitive to such global climate changes. An attempt has been made to evaluate the altitude, climate and environmental data on selected study sites of Sikkim for a period of two years (2014-2015) for discerning potential distribution of C.orientalis in this region. The altitude, temperature, precipitation and potential distribution range maps of C. orientalis showed the areas of highest species abundance within the altitudinal range of 550-1830m, with some species extending its range up to 3750m, with average precipitation of 2010-2590mm and mean temperature of 11-18°C. The Maximum Entropy Modelling (MaxEnt) and the Jackknife test of the MaxEnt model further revealed that the major contributing factors governing C. orientalis distribution are annual precipitation (78.8%), followed by precipitation of driest quarter (8.3%) and mean temperature of the warmest quarter (3.3%). Accuracy of the study was evaluated by the area under the curve (AUC=0.860). The Biplot on F1-F2 axes (N=16, α=0.05) in the PCA showed the linear depiction of all the variables considered in our study, major contributors were annual precipitation, precipitation of driest quarter and mean temperature of warmest quarter being the primary factors governing species distribution, as analogous to results of the MaxEnt model. This study would help in developing strategies for monitoring and

  17. A new interaction potential for swarming models

    CERN Document Server

    Carrillo, J A; Panferov, V

    2012-01-01

    We consider a self-propelled particle system which has been used to describe certain types of collective motion of animals, such as fish schools and bird flocks. Interactions between particles are specified by means of a pairwise potential, repulsive at short ranges and attractive at longer ranges. The exponentially decaying Morse potential is a typical choice, and is known to reproduce certain types of collective motion observed in nature, particularly aligned flocks and rotating mills. We introduce a class of interaction potentials, that we call Quasi-Morse, for which flock and rotating mills states are also observed numerically, however in that case the corresponding macroscopic equations allow for explicit solutions in terms of special functions, with coefficients that can be obtained numerically without solving the particle evolution. We compare thus obtained solutions with long-time dynamics of the particle systems and find a close agreement for several types of flock and mill solutions.

  18. A new interaction potential for swarming models

    Science.gov (United States)

    Carrillo, J. A.; Martin, S.; Panferov, V.

    2013-10-01

    We consider a self-propelled particle system which has been used to describe certain types of collective motion of animals, such as fish schools and bird flocks. Interactions between particles are specified by means of a pairwise potential, repulsive at short ranges and attractive at longer ranges. The exponentially decaying Morse potential is a typical choice, and is known to reproduce certain types of collective motion observed in nature, particularly aligned flocks and rotating mills. We introduce a class of interaction potentials, that we call Quasi-Morse, for which flock and rotating mills states are also observed numerically, however in that case the corresponding macroscopic equations allow for explicit solutions in terms of special functions, with coefficients that can be obtained numerically without solving the particle evolution. We compare the obtained solutions with long-time dynamics of the particle systems and find a close agreement for several types of flock and mill solutions.

  19. A comparison between standard methods and structural nested modelling when bias from a healthy worker survivor effect is suspected: an iron-ore mining cohort study.

    Science.gov (United States)

    Björ, Ove; Damber, Lena; Jonsson, Håkan; Nilsson, Tohr

    2015-07-01

    Iron-ore miners are exposed to extremely dusty and physically arduous work environments. The demanding activities of mining select healthier workers with longer work histories (ie, the Healthy Worker Survivor Effect (HWSE)), and could have a reversing effect on the exposure-response association. The objective of this study was to evaluate an iron-ore mining cohort to determine whether the effect of respirable dust was confounded by the presence of an HWSE. When an HWSE exists, standard modelling methods, such as Cox regression analysis, produce biased results. We compared results from g-estimation of accelerated failure-time modelling adjusted for HWSE with corresponding unadjusted Cox regression modelling results. For all-cause mortality when adjusting for the HWSE, cumulative exposure from respirable dust was associated with a 6% decrease of life expectancy if exposed ≥15 years, compared with never being exposed. Respirable dust continued to be associated with mortality after censoring outcomes known to be associated with dust when adjusting for the HWSE. In contrast, results based on Cox regression analysis did not support that an association was present. The adjustment for the HWSE made a difference when estimating the risk of mortality from respirable dust. The results of this study, therefore, support the recommendation that standard methods of analysis should be complemented with structural modelling analysis techniques, such as g-estimation of accelerated failure-time modelling, to adjust for the HWSE. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  20. Modeling the Clarification Potential of Instructions

    DEFF Research Database (Denmark)

    Benotti, Luciana; Blackburn, Patrick Rowan

    2017-01-01

    We hypothesize that conversational implicatures are a rich source of clarification requests, and in this paper we do two things. First, we motivate the hypothesis in theoretical, practical and empirical terms and formulate it as a concrete Clarification Potential Principle: implicatures may become...

  1. Glueball Masses in Relativistic Potential Model

    CERN Document Server

    Shpenik, A; Kis, J; Fekete, Yu

    2000-01-01

    The problem of glueball mass spectra using the relativistic Dirac equation is studied. Also the Breit-Fermi approach used to obtaining hyperfine splitting in glueballs. Our approach is based on the assumption, that the nature and the forces between two gluons are the short-range. We were to calculate the glueball masses with used screened potential.

  2. Evaluating the Pedagogical Potential of Hybrid Models

    Science.gov (United States)

    Levin, Tzur; Levin, Ilya

    2013-01-01

    The paper examines how the use of hybrid models--that consist of the interacting continuous and discrete processes--may assist in teaching system thinking. We report an experiment in which undergraduate students were asked to choose between a hybrid and a continuous solution for a number of control problems. A correlation has been found between…

  3. Potential of mathematical modeling in fruit quality

    African Journals Online (AJOL)

    ONOS

    2010-01-18

    Jan 18, 2010 ... estimate seasonal changes in quality traits as fruit size, dry matter, water content and the concentration of sugars and ... The global goodness-of-fit of a model is computed by averaging the ... into account climate variables such as radiation, salinity, .... and on exponential light extinction (Beer-Lambert Law).

  4. Predictors of leadership: The usual suspects and the suspect traits

    OpenAIRE

    Antonakis, J.

    2011-01-01

    In this chapter, I review literature on traits (i.e., individual differences) and their links to leader outcomes. I present an integrated model, the ascription-actuality trait theory, to explain two routes to leader outcomes that stem from traits: the route that objectively matters and the route that appears to matter but objectively may not. I discuss the history of trait research and provide criteria by which we should judge the validity of trait models. Finally, I review trait models that ...

  5. Enterprise marketing potential modeling taking into account optimizing and dynamic essence of the potential

    Directory of Open Access Journals (Sweden)

    Potrashkova Lyudmyla Vladimirovna

    2014-12-01

    Full Text Available The aim of the article. The aim of the research is to develop models system concerning b2b-enterprise marketing potential result-based estimation, which will consider enterprise potential optimizing essence, its hierarchic structure (i.e. strategic, tactic and operative potential levels and marketing resources dynamics. The results of the analysis. The simulation and optimization models system of the b2b-enterprise marketing potential estimation is suggested. The suggested models system is based on the following theoretical grounds: 1 enterprise marketing potential is interpreted as enterprise ability to satisfy consumers’ needs and to get maximum economic benefits from it; 2 the result-based estimation of the enterprise marketing potential is set of the best results (profit from sales, which sales and marketing enterprise subsystem may achieve in the prognosticative period in the view of environmental conditions variants. The suggested system unites models to estimate three managerial levels of the marketing potential (operative, tactic and strategic, which are different from each other by: the set of the given managerial decisions; the set of the changeable managerial decisions; descriptions of the environment parameters; specification of the resources featured describing. Model of each marketing potential level has the following constituents: - objective function, which is the sum of profit from production realization during the whole prognosticative period; - model of the constrained optimization, oriented to define maximum possible profit value from production realization in each elementary period with given marketing resources features values, environmental parameters and marketing complex parameters; - model of the enterprise marketing resources dynamics. Developed models system belongs to the simulation class, because search of the optimal decisions there is conducted with method concerning controllable parameters alternative variants

  6. APPROXIMATING INNOVATION POTENTIAL WITH NEUROFUZZY ROBUST MODEL

    Directory of Open Access Journals (Sweden)

    Kasa, Richard

    2015-01-01

    Full Text Available In a remarkably short time, economic globalisation has changed the world’s economic order, bringing new challenges and opportunities to SMEs. These processes pushed the need to measure innovation capability, which has become a crucial issue for today’s economic and political decision makers. Companies cannot compete in this new environment unless they become more innovative and respond more effectively to consumers’ needs and preferences – as mentioned in the EU’s innovation strategy. Decision makers cannot make accurate and efficient decisions without knowing the capability for innovation of companies in a sector or a region. This need is forcing economists to develop an integrated, unified and complete method of measuring, approximating and even forecasting the innovation performance not only on a macro but also a micro level. In this recent article a critical analysis of the literature on innovation potential approximation and prediction is given, showing their weaknesses and a possible alternative that eliminates the limitations and disadvantages of classical measuring and predictive methods.

  7. Potts Flux Tube Model at Nonzero Chemical Potential

    CERN Document Server

    Condella, J; Condella, Jac; Tar, Carleton De

    2000-01-01

    We model the deconfinement phase transition in quantum chromodynamics at nonzero baryon number density and large quark mass by extending the flux tube model (three-state, three-dimensional Potts model) to nonzero chemical potential. In a direct numerical simulation we confirm mean-field-theory predictions that the deconfinement transition does not occur in a baryon-rich environment.

  8. Heavy quark potential from deformed AdS5 models

    Science.gov (United States)

    Zhang, Zi-qiang; Hou, De-fu; Chen, Gang

    2017-04-01

    In this paper, we investigate the heavy quark potential in some holographic QCD models. The calculation relies on a modified renormalization scheme mentioned in a previous work of Albacete et al. After studying the heavy quark potential in Pirner-Galow model and Andreev-Zakharov model, we extend the discussion to a general deformed AdS5 case. It is shown that the obtained potential is negative definite for all quark-antiquark separations, differs from that using the usual renormalization scheme.

  9. On the potential of a singlet scalar enhanced Standard Model

    CERN Document Server

    Ghosh, Swagata; Ray, Shamayita

    2015-01-01

    We investigate the parameter space of the Standard Model enhanced by a gauge singlet real scalar $S$. Taking into account all the theoretical and experimental constraints, we show the allowed parameter space for two different types of such singlet-enhanced Standard Model. For the first case, the scalar potential has an explicit $Z_2$-symmetry, and may lead to a dark matter candidate under certain conditions. For the second case, the scalar potential does not respect any $Z_2$. This is again divided into two subcategories: one where the Standard Model vacuum is stable, and one where it is unstable and can decay into a deeper minimum. We show how the parameters in the scalar potential control the range of validity of all these models. Finally, we show the effect of one-loop correction on the positions and depths of the minima of the potential.

  10. A Functional Inspection Model for the Immeasurable Potential Failure State

    Institute of Scientific and Technical Information of China (English)

    ZHU Wen-ge; LI Shi-qi; ZHAO Di

    2008-01-01

    Functional inspection is a type of preventive maintenance of Reliability Centered Maintenance (RCM). We, in this paper, establish a functional inspection model(FIM)--the cost model and the availability model for the immeasurable potential failure state based on the delay time concept. This model can be used to determine the appropriate Functional Inspection Interval(FII) to achieve the goal of specific cost and availability and to assist in maintenance decision making.

  11. The model of evaluation of innovative potential of enterprise

    Directory of Open Access Journals (Sweden)

    Ганна Ігорівна Заднєпровська

    2015-06-01

    Full Text Available The basic components of the enterprise’s innovative potential evaluation process are investigated. It is offered the conceptual model of evaluation of the innovative potential that includes: subjects, objects, purpose, provision of information, principles, methods, criteria, indicators. It is noted that the innovative capacity characterizes the transition from the current to the strategic level of innovation potential and, thus, characterizes the composition of objects from position of user

  12. Confining diffuse potential versus square-well-potential in modeling A@C60 atoms

    CERN Document Server

    Dolmatov, V K; Oglesby, J C

    2011-01-01

    It is shown that discontinuity, inherit to a square-well potential which is often used for mimicking the C60 cage potential, results neither in qualitative nor, what is even more important, quantitative artifacts in problems of endohedral A@C60 atoms, such as their photoionization. Moreover, it is demonstrated that, upon mimicking a square-well potential by a potential with diffuse boarders, calculated photoionization spectra are largely insensitive to the degree {\\eta} of diffuseness of the potential boarders, in a reasonably broad range of {\\eta}'s. The proof is based on results of comparison between calculated data for H@C60 and Xe@C60 photoionization cross sections and photoelectron angular asymmetries obtained by modeling the C$_{60}$ cage by confining square-well and diffuse potentials. Thus, it matters little which of these potentials to use in A@C60 problems. The diffuse potential is modeled by a combination of two Woods-Saxon potentials. Calculated data for the photoionization of Xe@C60 are separatel...

  13. Extended Quark Potential Model From Random Phase Approximation

    Institute of Scientific and Technical Information of China (English)

    DENGWei-Zhen; CHENXiao-Lin; 等

    2002-01-01

    The quark potential model is extended to include the sea quark excitation using the random phase approximation.The effective quark interaction preserves the important QCD properties-chiral symmetry and confinement simultaneously.A primary qualitative analysis shows that the π meson as a well-known typical Goldstone boson and the other mesons made up of valence qq quark pair such as the ρ meson can also be described in this extended quark potential model.

  14. Crossing symmetric potential model of pion-nucleon scattering

    CERN Document Server

    Blankleider, B; Skawronski, T

    2010-01-01

    A crossing symmetric $\\pi N$ scattering amplitude is constructed through a complete attachment of two external pions to the dressed nucleon propagator of an underlying $\\pi N$ potential model. Our formulation automatically provides expressions also for the crossing symmetric and gauge invariant pion photoproduction and Compton scattering amplitudes. We show that our amplitudes are unitary if they coincide on-shell with the amplitudes obtained by attaching one pion to the dressed $\\pi NN$ vertex of the same potential model.

  15. Nucleon Spin Content in a Relativistic Quark Potential Model Approach

    Institute of Scientific and Technical Information of China (English)

    DONG YuBing; FENG QingGuo

    2002-01-01

    Based on a relativistic quark model approach with an effective potential U(r) = (ac/2)(1 + γ0)r2, the spin content of the nucleon is investigated. Pseudo-scalar interaction between quarks and Goldstone bosons is employed to calculate the couplings between the Goldstone bosons and the nucleon. Different approaches to deal with the center of mass correction in the relativistic quark potential model approach are discussed.

  16. Examination of a Theoretical Model of Streaming Potential Coupling Coefficient

    Directory of Open Access Journals (Sweden)

    D. T. Luong

    2014-01-01

    Full Text Available Seismoelectric effects and streaming potentials play an important role in geophysical applications. The key parameter for those phenomena is the streaming potential coupling coefficient, which is, for example, dependent on the zeta potential of the interface of the porous rocks. Comparison of an existing theoretical model to experimental data sets from available published data for streaming potentials has been performed. However, the existing experimental data sets are based on samples with dissimilar fluid conductivity, pH of pore fluid, temperature, and sample compositions. All those dissimilarities may cause the observed deviations. To critically assess the models, we have carried out streaming potential measurement as a function of electrolyte concentration and temperature for a set of well-defined consolidated samples. The results show that the existing theoretical model is not in good agreement with the experimental observations when varying the electrolyte concentration, especially at low electrolyte concentration. However, if we use a modified model in which the zeta potential is considered to be constant over the electrolyte concentration, the model fits the experimental data well in a whole range of concentration. Also, for temperature dependence, the comparison shows that the theoretical model is not fully adequate to describe the experimental data but does describe correctly the increasing trend of the coupling coefficient as function of temperature.

  17. Quadratic adaptive algorithm for solving cardiac action potential models.

    Science.gov (United States)

    Chen, Min-Hung; Chen, Po-Yuan; Luo, Ching-Hsing

    2016-10-01

    An adaptive integration method is proposed for computing cardiac action potential models accurately and efficiently. Time steps are adaptively chosen by solving a quadratic formula involving the first and second derivatives of the membrane action potential. To improve the numerical accuracy, we devise an extremum-locator (el) function to predict the local extremum when approaching the peak amplitude of the action potential. In addition, the time step restriction (tsr) technique is designed to limit the increase in time steps, and thus prevent the membrane potential from changing abruptly. The performance of the proposed method is tested using the Luo-Rudy phase 1 (LR1), dynamic (LR2), and human O'Hara-Rudy dynamic (ORd) ventricular action potential models, and the Courtemanche atrial model incorporating a Markov sodium channel model. Numerical experiments demonstrate that the action potential generated using the proposed method is more accurate than that using the traditional Hybrid method, especially near the peak region. The traditional Hybrid method may choose large time steps near to the peak region, and sometimes causes the action potential to become distorted. In contrast, the proposed new method chooses very fine time steps in the peak region, but large time steps in the smooth region, and the profiles are smoother and closer to the reference solution. In the test on the stiff Markov ionic channel model, the Hybrid blows up if the allowable time step is set to be greater than 0.1ms. In contrast, our method can adjust the time step size automatically, and is stable. Overall, the proposed method is more accurate than and as efficient as the traditional Hybrid method, especially for the human ORd model. The proposed method shows improvement for action potentials with a non-smooth morphology, and it needs further investigation to determine whether the method is helpful during propagation of the action potential. Copyright © 2016 Elsevier Ltd. All rights

  18. Fine Tuning in Quintessence Models with Exponential Potentials

    CERN Document Server

    Rosenfeld, R; Jr., Urbano Lopes Franca; Rosenfeld, Rogerio

    2002-01-01

    We show that there still are reasonable regions of the parameter space of the simple exponential potential model for quintessence that are allowed by observational constraints. We find that the level of fine tuning that is required in this model is not too stringent.

  19. On the hydrologic adjustment of climate-model projections: The potential pitfall of potential evapotranspiration

    Science.gov (United States)

    Milly, P.C.D.; Dunne, K.A.

    2011-01-01

    Hydrologic models often are applied to adjust projections of hydroclimatic change that come from climate models. Such adjustment includes climate-bias correction, spatial refinement ("downscaling"), and consideration of the roles of hydrologic processes that were neglected in the climate model. Described herein is a quantitative analysis of the effects of hydrologic adjustment on the projections of runoff change associated with projected twenty-first-century climate change. In a case study including three climate models and 10 river basins in the contiguous United States, the authors find that relative (i.e., fractional or percentage) runoff change computed with hydrologic adjustment more often than not was less positive (or, equivalently, more negative) than what was projected by the climate models. The dominant contributor to this decrease in runoff was a ubiquitous change in runoff (median 211%) caused by the hydrologic model's apparent amplification of the climate-model-implied growth in potential evapotranspiration. Analysis suggests that the hydrologic model, on the basis of the empirical, temperature-based modified Jensen-Haise formula, calculates a change in potential evapotranspiration that is typically 3 times the change implied by the climate models, which explicitly track surface energy budgets. In comparison with the amplification of potential evapotranspiration, central tendencies of other contributions from hydrologic adjustment (spatial refinement, climate-bias adjustment, and process refinement) were relatively small. The authors' findings highlight the need for caution when projecting changes in potential evapotranspiration for use in hydrologic models or drought indices to evaluate climatechange impacts on water. Copyright ?? 2011, Paper 15-001; 35,952 words, 3 Figures, 0 Animations, 1 Tables.

  20. Optimal schooling formations using a potential flow model

    Science.gov (United States)

    Tchieu, Andrew; Gazzola, Mattia; de Brauer, Alexia; Koumoutsakos, Petros

    2012-11-01

    A self-propelled, two-dimensional, potential flow model for agent-based swimmers is used to examine how fluid coupling affects schooling formation. The potential flow model accounts for fluid-mediated interactions between swimmers. The model is extended to include individual agent actions by means of modifying the circulation of each swimmer. A reinforcement algorithm is applied to allow the swimmers to learn how to school in specified lattice formations. Lastly, schooling lattice configurations are optimized by combining reinforcement learning and evolutionary optimization to minimize total control effort and energy expenditure.

  1. Suspected poisoning of domestic animals by pesticides.

    Science.gov (United States)

    Caloni, Francesca; Cortinovis, Cristina; Rivolta, Marina; Davanzo, Franca

    2016-01-01

    A retrospective study was carried out by reviewing all suspected cases of domestic animal poisoning attributed to pesticides, reported to the Milan Poison Control Centre (MPCC) between January 2011 and December 2013. During this period, pesticides were found to be responsible for 37.3% of all suspected poisoning enquiries received (815). The most commonly species involved was the dog (71.1% of calls) followed by the cat (15.8%), while a limited number of cases involved horses, goats and sheep. Most cases of exposure (47.1%) resulted in mild to moderate clinical signs. The outcome was reported in 59.9% of these cases, with death occurring in 10.4% of them. Insecticides (40.8%) proved to be the most common group of pesticides involved and exposure to pyrethrins-pyrethroids accounted for the majority of calls. According to the MPCC data, there has been a decrease in the number of suspected poisonings cases attributed to pesticides that have been banned by the EU, including aldicarb, carbofuran, endosulfan and paraquat. In contrast, there has been an increase of suspected poisoning cases attributed to the neonicotinoids, imidacloprid and acetamiprid, probably due to their widespread use in recent years. Cases of suspected poisoning that involved exposure to rodenticides accounted for 27.6% of calls received by the MPCC and anticoagulant rodenticides were the primary cause of calls, with many cases involving brodifacoum and bromadiolone. Herbicides were involved in 14.2% of calls related to pesticides and glyphosate was the main culprit in cases involving dogs, cats, horses, goats and sheep. As far as exposure to molluscicides (11.5%) and fungicides (5.9%), most of the cases involved dogs and the suspected poisoning agents were metaldehyde and copper compounds respectively. The data collected are useful in determining trends in poisoning episodes and identifying newly emerging toxicants, thus demonstrating the prevalence of pesticides as causative agents in animal

  2. Novel mixture model for the representation of potential energy surfaces

    Science.gov (United States)

    Pham, Tien Lam; Kino, Hiori; Terakura, Kiyoyuki; Miyake, Takashi; Dam, Hieu Chi

    2016-10-01

    We demonstrate that knowledge of chemical physics on a materials system can be automatically extracted from first-principles calculations using a data mining technique; this information can then be utilized to construct a simple empirical atomic potential model. By using unsupervised learning of the generative Gaussian mixture model, physically meaningful patterns of atomic local chemical environments can be detected automatically. Based on the obtained information regarding these atomic patterns, we propose a chemical-structure-dependent linear mixture model for estimating the atomic potential energy. Our experiments show that the proposed mixture model significantly improves the accuracy of the prediction of the potential energy surface for complex systems that possess a large diversity in their local structures.

  3. A case of suspect “cyanosis”

    Directory of Open Access Journals (Sweden)

    Elisabetta Antonucci

    2013-05-01

    Full Text Available CLINICAL CASE A 70-year old woman was admitted to our hospital because of fever, asthenia and a suspected stroke. Her medical history showed a congenital cardiopathy (Patent Foramen Ovale, PFO. Skin and oral mucosa pigmentation, orthostatic hypotension, hypoglycemia and hyponatriemia arose the suspect of Addison’s disease. The diagnosis was confirmed by the evaluation of basal levels of plasma ACTH and serum cortisol, and serum cortisol levels after ACTH stimulation. Abdominal CT scan showed atrophy and calcification of adrenal glands. CONCLUSIONS In most cases, Addison’s disease is provoked by autoimmune destruction of the adrenal cortex; however, in our reported patient, tuberculosis could be a possible cause.

  4. A computer simulation of a potential derived from the gay-berne potential for lattice model

    Directory of Open Access Journals (Sweden)

    Habtamu Zewdie

    2000-06-01

    Full Text Available The lattice model of elongated molecules interacting via a potential derived from the Gay-Berne pair potential is proposed. We made a systematic study of the effect of varying the molecular elongation and intermolecular vector orientation dependence of the pair potential on the thermodynamic as well as the structural properties of liquid crystals. A Monte Carlo simulations of molecules placed at the site of a simple cubic lattice and interacting via the modified Gay-Berne potential with its nearest neighbours is performed. The internal energy, heat capacity, angular pair correlation function and scalar order parameter are obtained. The results are compared against predictions of molecular field theory, experimental results and that of other related simulations wherever possible. It is shown that for more elongated molecules the nematic-isotropic transition becomes stronger first order transition. For a given molecular elongation as the intermolecular vector orientation dependence becomes larger the nematic-isotropic transition becomes a stronger first order transition as measured by the rate of change of the order parameter and the divergence of the heat capacity. Scaling the potential well seems to have dramatic change on the effect of the potential well anisotropy on trends of nematic-isotropic transition temperature and divergence of the heat capacity. It is shown that the behaviour of many nematics can be described by proposed model with the elongation ratio of molecules and potential well anisotropy ranging from 3 to 5.

  5. Modeling transient streaming potentials in falling-head permeameter tests.

    Science.gov (United States)

    Malama, Bwalya; Revil, André

    2014-01-01

    We present transient streaming potential data collected during falling-head permeameter tests performed on samples of two sands with different physical and chemical properties. The objective of the work is to estimate hydraulic conductivity (K) and the electrokinetic coupling coefficient (Cl ) of the sand samples. A semi-empirical model based on the falling-head permeameter flow model and electrokinetic coupling is used to analyze the streaming potential data and to estimate K and Cl . The values of K estimated from head data are used to validate the streaming potential method. Estimates of K from streaming potential data closely match those obtained from the associated head data, with less than 10% deviation. The electrokinetic coupling coefficient was estimated from streaming potential vs. (1) time and (2) head data for both sands. The results indicate that, within limits of experimental error, the values of Cl estimated by the two methods are essentially the same. The results of this work demonstrate that a temporal record of the streaming potential response in falling-head permeameter tests can be used to estimate both K and Cl . They further indicate the potential for using transient streaming potential data as a proxy for hydraulic head in hydrogeology applications.

  6. Aeroallergen patch testing in patients of suspected contact dermatitis

    Directory of Open Access Journals (Sweden)

    Nelee Bisen

    2014-01-01

    Full Text Available Background: Aeroallergens are airborne substances present in the environment with the potential to trigger an allergic reaction in the respiratory tract, mucosae, or skin of susceptible individuals. The relevance of aeroallergens in the pathogenesis of atopic dermatitis has been reported by many investigators. However, very few studies have been conducted to investigate their role in the production of allergic contact dermatitis (ACD. Aims: To determine the prevalence of aeroallergen patch test positivity in patients of suspected ACD and to study the clinical characteristics of patients testing positive with aeroallergens. Materials and Methods: Patients presenting to our department with suspected contact allergy and undergoing patch testing with Indian Standard Series (ISS between January 2010 and June 2011 were studied. After a detailed history and clinical examination, patients were patch tested with ISS and aeroallergen series. Based on the history and clinical suspicion, patients were additionally patch tested with 15% Parthenium. Prior tape stripping was done in some patients. Results: Out of total 114 patients, 26 (22.8% showed sensitivity to aeroallergen series. Parthenium was the commonest aeroallergen being positive in all 26 patients followed by Xanthium in two. None reacted to other allergens. Although positivity was more in patients with prior tape stripping, the difference was not statistically significant. Conclusion: Most common aeroallergen found to be positive in our study was Parthenium hysterophorus. In view of low positivity to other allergens, routine aeroallergen patch testing in patients with suspected contact dermatitis may not be necessary.

  7. The parabolic Anderson model random walk in random potential

    CERN Document Server

    König, Wolfgang

    2016-01-01

    This is a comprehensive survey on the research on the parabolic Anderson model – the heat equation with random potential or the random walk in random potential – of the years 1990 – 2015. The investigation of this model requires a combination of tools from probability (large deviations, extreme-value theory, e.g.) and analysis (spectral theory for the Laplace operator with potential, variational analysis, e.g.). We explain the background, the applications, the questions and the connections with other models and formulate the most relevant results on the long-time behavior of the solution, like quenched and annealed asymptotics for the total mass, intermittency, confinement and concentration properties and mass flow. Furthermore, we explain the most successful proof methods and give a list of open research problems. Proofs are not detailed, but concisely outlined and commented; the formulations of some theorems are slightly simplified for better comprehension.

  8. Evaluating Damage Potential in Security Risk Scoring Models

    Directory of Open Access Journals (Sweden)

    Eli Weintraub

    2016-05-01

    Full Text Available A Continuous Monitoring System (CMS model is presented, having new improved capabilities. The system is based on the actual real-time configuration of the system. Existing risk scoring models assume damage potential is estimated by systems' owner, thus rejecting the information relying in the technological configuration. The assumption underlying this research is based on users' ability to estimate business impacts relating to systems' external interfaces which they use regularly in their business activities, but are unable to assess business impacts relating to internal technological components. According to the proposed model systems' damage potential is calculated using technical information on systems' components using a directed graph. The graph is incorporated into the Common Vulnerability Scoring Systems' (CVSS algorithm to produce risk scoring measures. Framework presentation includes system design, damage potential scoring algorithm design and an illustration of scoring computations.

  9. Compactification of gauge models and the effective potential

    Energy Technology Data Exchange (ETDEWEB)

    Shtykov, N.N. (Leningrad State University, Leningrad (SU))

    1989-07-01

    The one-loop potential for bosons and massive fermions in an Abelian model is obtained on the {ital M}{sup 2}{times}{ital S1}{times}{ital S1} manifold. Stability of the total potential against arbitrary homogeneous deformations of {ital S}{sup 1}{times}{ital S1} is studied. It is shown that attraction or repulsion depends on the relations connecting the radii of the spheres, the fermion masses, and the coupling constant.

  10. Hydranencephaly in a case of suspected infanticide.

    Science.gov (United States)

    Verzeletti, Andrea; Leide, Anna; De Ferrari, Francesco

    2015-04-01

    An abandoned fetus with suspicious skin injuries was found dead, lying on the grass of a garden, near a private house. Suspecting infanticide, the prosecutor ordered a medico-legal autopsy. The cause of death was identified as a congenital malformation of the central nervous system such as hydranencephaly, and infanticide was excluded.

  11. MRI for clinically suspected appendicitis during pregnancy.

    NARCIS (Netherlands)

    Cobben, L.P.; Groot, I.; Haans, L.; Blickman, J.G.; Puylaert, J.

    2004-01-01

    OBJECTIVE: The purpose of this study was to evaluate whether MRI can be used to accurately diagnose or exclude appendicitis in pregnant patients with clinically suspected appendicitis. CONCLUSION: Our results suggest that MRI is helpful in the examination and diagnosis of acute appendicitis in pregn

  12. Characterization of suspected illegal skin whitening cosmetics.

    Science.gov (United States)

    Desmedt, B; Van Hoeck, E; Rogiers, V; Courselle, P; De Beer, J O; De Paepe, K; Deconinck, E

    2014-03-01

    An important group of suspected illegal cosmetics consists of skin bleaching products, which are usually applied to the skin of the face, hands and décolleté for local depigmentation of hyper pigmented regions or more importantly, for a generalized reduction of the skin tone. These cosmetic products are suspected to contain illegal active substances that may provoke as well local as systemic toxic effects, being the reason for their banning from the EU market. In that respect, illegal and restricted substances in cosmetics, known to have bleaching properties, are in particular hydroquinone, tretinoin and corticosteroids. From a legislative point of view, all cosmetic products containing a prohibited whitening agent are illegal and must be taken off the EU market. A newly developed screening method using ultra high performance liquid chromatography-time off flight-mass spectrometry allows routine analysis of suspected products. 163 suspected skin whitening cosmetics, collected by Belgian inspectors at high risk sites such as airports and so-called ethnic cosmetic shops, were analyzed and 59% were classified as illegal. The whitening agents mostly detected were clobetasol propionate and hydroquinone, which represent a serious health risk when repeatedly and abundantly applied to the skin.

  13. Evaluation of six potential evapotranspiration models for estimating crop potential and actual evapotranspiration in arid regions

    Science.gov (United States)

    Li, Sien; Kang, Shaozhong; Zhang, Lu; Zhang, Jianhua; Du, Taisheng; Tong, Ling; Ding, Risheng

    2016-12-01

    Using potential evapotranspiration (PET) to estimate crop actual evapotranspiration (AET) is a critical approach in hydrological models. However, which PET model performs best and can be used to predict crop AET over the entire growth season in arid regions still remains unclear. The six frequently-used PET models, i.e. Blaney-Criddle (BC), Hargreaves (HA), Priestley-Taylor (PT), Dalton (DA), Penman (PE) and Shuttleworth (SW) models were considered and evaluated in the study. Five-year eddy covariance data over the maize field and vineyard in arid northwest China were used to examine the accuracy of PET models in estimating daily crop AET. Results indicate that the PE, SW and PT models underestimated daily ET by less than 6% with RMSE lower than 35 W m-2 during the four years, while the BC, HA and DA models under-predicted daily ET approximately by 10% with RMSE higher than 40 W m-2. Compared to BC, HA and DA models, PE, SW and PT models were more reliable and accurate for estimating crop PET and AET in arid regions. Thus the PE, SW and PT models were recommended for predicting crop evapotranspiration in hydrological models in arid regions.

  14. Fisher information and quantum potential well model for finance

    Energy Technology Data Exchange (ETDEWEB)

    Nastasiuk, V.A., E-mail: nasa@i.ua

    2015-09-25

    The probability distribution function (PDF) for prices on financial markets is derived by extremization of Fisher information. It is shown how on that basis the quantum-like description for financial markets arises and different financial market models are mapped by quantum mechanical ones. - Highlights: • The financial Schrödinger equation is derived using the principle of minimum Fisher information. • Statistical models for price variation are mapped by the quantum models of coupled particle. • The model of quantum particle in parabolic potential well corresponds to Efficient market.

  15. Constructing A Small Strain Potential for Multi-Scale Modeling

    CERN Document Server

    Mallik, A; Cheng, H P; Dufty, J W; Mallik, Aditi; Runge, Keith; Cheng, Hai-Ping; Dufty, James W.; Mallik, Aditi; Runge, Keith; Cheng, Hai-Ping; Dufty, James W.

    2005-01-01

    For problems relating to fracture, a consistent embedding of a quantum (QM) domain in its classical (CM) environment requires that the classical system should yield the same structure and elastic properties as the QM domain for states near equilibrium. It is proposed that an appropriate classical potential can be constructed using ab initio data on the equilibrium and weakly strained configurations calculated from the quantum description, rather than the more usual approach of fitting to a wide range of empirical data. The scheme is illustrated in detail for a model system, silica nanorod that has the proper stiochiometric ratio of Si:O as observed in real silica. The potential is chosen to be pairwise additive, with the same pair potential functional form as familiar phenomenological TTAM potential. Here, the parameters are determined using a genetic algorithm with force data obtained directly from a quantum calculation. The resulting potential gives excellent agreement with properties of the reference quant...

  16. A New Method for Characterizing Single Parametric Model Potential

    Institute of Scientific and Technical Information of China (English)

    P.S. Vyas; P.N. Gajjar; B.Y. Thakore; A.R. Jani

    2008-01-01

    A novel approach of characterizing single parametric model potential is proposed by equating total pair wise force to zero.Our well-established single parametric model potential is characterized using the proposed idea and compared the obtained parameter with parameters computed by previously used approaches.Thus characterized pseudopotential is then tested to compute total energy of alkali metals.The results establish the reliability of proposed idea of making total pair wise force to zero in determining the parameter of the pseudopotential.

  17. Teratogenic Potential of Antiepileptic Drugs in the Zebrafish Model

    Directory of Open Access Journals (Sweden)

    Sung Hak Lee

    2013-01-01

    Full Text Available The zebrafish model is an attractive candidate for screening of developmental toxicity during early drug development. Antiepileptic drugs (AEDs arouse concern for the risk of teratogenicity, but the data are limited. In this study, we evaluated the teratogenic potential of seven AEDs (carbamazepine (CBZ, ethosuximide (ETX, valproic acid (VPN, lamotrigine (LMT, lacosamide (LCM, levetiracetam (LVT, and topiramate (TPM in the zebrafish model. Zebrafish embryos were exposed to AEDs from initiation of gastrula (5.25 hours post-fertilization (hpf to termination of hatching (72 hpf which mimic the mammalian teratogenic experimental design. The lethality and teratogenic index (TI of AEDs were determined and the TI values of each drug were compared with the US FDA human pregnancy categories. Zebrafish model was useful screening model for teratogenic potential of antiepilepsy drugs and was in concordance with in vivo mammalian data and human clinical data.

  18. Extended Quark Potential Model from Random Phase Approximation

    Institute of Scientific and Technical Information of China (English)

    DENG Wei-Zhen; CHEN Xiao-Lin; LU Da-Hai; YANG Li-Ming

    2002-01-01

    The quark potential model is extended to include the sea quark excitation using the random phase approx-imation. The effective quark interaction preserves the important QCD properties - chiral symmetry and confinementsimultaneously. A primary qualitative analysis shows that the π meson as a well-known typical Goldstone boson andthe other mesons made up of valence qq quark pair such as the ρ meson can also be described in this extended quarkpotential model.

  19. Comprehensive training in suspected child abuse and neglect for dental students: a hybrid curriculum.

    Science.gov (United States)

    Ivanoff, Chris S; Hottel, Timothy L

    2013-06-01

    Child abuse and neglect are tragic realities of American society. However, most U.S. dental schools do not provide students with adequate training to deal with the problem. This article proposes expanding the predoctoral dental curriculum with a problem-based learning model that can effectively stimulate critical thinking skills to assist graduates in screening and reporting suspected child abuse and neglect throughout their careers. The unique multicultural environment of dental school offers students an unprecedented opportunity to develop awareness about child abuse and domestic violence, while increased vigilance can potentially save innocent young lives. Educating students about proper protocol when they suspect child abuse or neglect is imperative, particularly for dental schools involving students in community sealant and other preventive programs in public schools. By expanding their curriculum to include recognition and intervention, dental schools can help break the cycle of violence and transform attitudes towards taking decisive action. Clinical curricula that have moved to private practice preceptor models are well suited to screen for child abuse. The goal is to motivate dental schools to deal with this critical issue, develop reporting protocols and procedures for appropriate response, and provide their students with consummate training.

  20. Simple inflationary quintessential model. II. Power law potentials

    Science.gov (United States)

    de Haro, Jaume; Amorós, Jaume; Pan, Supriya

    2016-09-01

    The present work is a sequel of our previous work [Phys. Rev. D 93, 084018 (2016)] which depicted a simple version of an inflationary quintessential model whose inflationary stage was described by a Higgs-type potential and the quintessential phase was responsible due to an exponential potential. Additionally, the model predicted a nonsingular universe in past which was geodesically past incomplete. Further, it was also found that the model is in agreement with the Planck 2013 data when running is allowed. But, this model provides a theoretical value of the running which is far smaller than the central value of the best fit in ns , r , αs≡d ns/d l n k parameter space where ns, r , αs respectively denote the spectral index, tensor-to-scalar ratio and the running of the spectral index associated with any inflationary model, and consequently to analyze the viability of the model one has to focus in the two-dimensional marginalized confidence level in the allowed domain of the plane (ns,r ) without taking into account the running. Unfortunately, such analysis shows that this model does not pass this test. However, in this sequel we propose a family of models runs by a single parameter α ∈[0 ,1 ] which proposes another "inflationary quintessential model" where the inflation and the quintessence regimes are respectively described by a power law potential and a cosmological constant. The model is also nonsingular although geodesically past incomplete as in the cited model. Moreover, the present one is found to be more simple compared to the previous model and it is in excellent agreement with the observational data. In fact, we note that, unlike the previous model, a large number of the models of this family with α ∈[0 ,1/2 ) match with both Planck 2013 and Planck 2015 data without allowing the running. Thus, the properties in the current family of models compared to its past companion justify its need for a better cosmological model with the successive

  1. Zebrafish (Danio rerio): A Potential Model for Toxinological Studies.

    Science.gov (United States)

    Vargas, Rafael Antonio; Sarmiento, Karen; Vásquez, Isabel Cristina

    2015-10-01

    Zebrafish are an emerging basic biomedical research model that has multiple advantages compared with other research models. Given that biotoxins, such as toxins, poisons, and venoms, represent health hazards to animals and humans, a low-cost biological model that is highly sensitive to biotoxins is useful to understand the damage caused by such agents and to develop biological tests to prevent and reduce the risk of poisoning in potential cases of bioterrorism or food contamination. In this article, a narrative review of the general aspects of zebrafish as a model in basic biomedical research and various studies in the field of toxinology that have used zebrafish as a biological model are presented. This information will provide useful material to beginner students and researchers who are interested in developing toxinological studies with the zebrafish model.

  2. Action potential initiation in the hodgkin-huxley model.

    Directory of Open Access Journals (Sweden)

    Lucy J Colwell

    2009-01-01

    Full Text Available A recent paper of B. Naundorf et al. described an intriguing negative correlation between variability of the onset potential at which an action potential occurs (the onset span and the rapidity of action potential initiation (the onset rapidity. This correlation was demonstrated in numerical simulations of the Hodgkin-Huxley model. Due to this antagonism, it is argued that Hodgkin-Huxley-type models are unable to explain action potential initiation observed in cortical neurons in vivo or in vitro. Here we apply a method from theoretical physics to derive an analytical characterization of this problem. We analytically compute the probability distribution of onset potentials and analytically derive the inverse relationship between onset span and onset rapidity. We find that the relationship between onset span and onset rapidity depends on the level of synaptic background activity. Hence we are able to elucidate the regions of parameter space for which the Hodgkin-Huxley model is able to accurately describe the behavior of this system.

  3. Data-driven prioritization of chemicals for various water types using suspect screening LC-HRMS.

    Science.gov (United States)

    Sjerps, Rosa M A; Vughs, Dennis; van Leerdam, Jan A; ter Laak, Thomas L; van Wezel, Annemarie P

    2016-04-15

    For the prioritization of more than 5200 anthropogenic chemicals authorized on the European market, we use a large scale liquid chromatography-high resolution mass spectrometry (LC-HRMS) suspect screening study. The prioritization is based on occurrence in 151 water samples including effluent, surface water, ground water and drinking water. The suspect screening linked over 700 detected compounds with known accurate masses to one or multiple suspects. Using a prioritization threshold and removing false positives reduced this to 113 detected compounds linked to 174 suspects, 24 compounds reflect a confirmed structure by comparison with the pure reference standard. The prioritized compounds and suspects are relevant for detailed risk assessments after confirmation of their identity. Only one of the 174 prioritized compounds and suspects is mentioned in water quality regulations, and only 20% is mentioned on existing lists of potentially relevant chemicals. This shows the complementarity to commonly used target-based methods. The semi-quantitative total concentration, expressed as internal standard equivalents of detected compounds linked to suspects, in effluents is approximately 10 times higher than in surface waters, while ground waters and drinking waters show the lowest response. The average retention time, a measure for hydrophobicity, of the detected compounds per sample decreased from effluent to surface- and groundwater to drinking water, confirming the occurrence of more polar compounds in drinking water. The semi-quantitative total concentrations exceed the conservative and precautionary threshold of toxicological concern. Therefore, adverse effects of mixtures cannot be neglected without a more thorough risk assessment.

  4. Evaluation of potential crushed-salt constitutive models

    Energy Technology Data Exchange (ETDEWEB)

    Callahan, G.D.; Loken, M.C.; Sambeek, L.L. Van; Chen, R.; Pfeifle, T.W.; Nieland, J.D. [RE/SPEC Inc., Rapid City, SD (United States); Hansen, F.D. [Sandia National Labs., Albuquerque, NM (United States). Repository Isolation Systems Dept.

    1995-12-01

    Constitutive models describing the deformation of crushed salt are presented in this report. Ten constitutive models with potential to describe the phenomenological and micromechanical processes for crushed salt were selected from a literature search. Three of these ten constitutive models, termed Sjaardema-Krieg, Zeuch, and Spiers models, were adopted as candidate constitutive models. The candidate constitutive models were generalized in a consistent manner to three-dimensional states of stress and modified to include the effects of temperature, grain size, and moisture content. A database including hydrostatic consolidation and shear consolidation tests conducted on Waste Isolation Pilot Plant and southeastern New Mexico salt was used to determine material parameters for the candidate constitutive models. Nonlinear least-squares model fitting to data from the hydrostatic consolidation tests, the shear consolidation tests, and a combination of the shear and hydrostatic tests produces three sets of material parameter values for the candidate models. The change in material parameter values from test group to test group indicates the empirical nature of the models. To evaluate the predictive capability of the candidate models, each parameter value set was used to predict each of the tests in the database. Based on the fitting statistics and the ability of the models to predict the test data, the Spiers model appeared to perform slightly better than the other two candidate models. The work reported here is a first-of-its kind evaluation of constitutive models for reconsolidation of crushed salt. Questions remain to be answered. Deficiencies in models and databases are identified and recommendations for future work are made. 85 refs.

  5. On matrix model partition functions for QCD with chemical potential

    CERN Document Server

    Akemann, G; Vernizzi, G

    2004-01-01

    Partition functions of two different matrix models for QCD with chemical potential are computed for an arbitrary number of quark and complex conjugate anti-quark flavors. In the large-N limit of weak nonhermiticity complete agreement is found between the two models. This supports the universality of such fermionic partition functions, that is of products of characteristic polynomials in the complex plane. In the strong nonhermiticity limit agreement is found for an equal number of quark and conjugate flavours. For a general flavor content the equality of partition functions holds only for small chemical potential. The chiral phase transition is analyzed for an arbitrary number of quarks, where the free energy presents a discontinuity of first order at a critical chemical potential. In the case of nondegenerate flavors there is first order phase transition for each separate mass scale.

  6. Effective constraint potential in lattice Weinberg - Salam model

    CERN Document Server

    Polikarpov, M I

    2011-01-01

    We investigate lattice Weinberg - Salam model without fermions for the value of the Weinberg angle $\\theta_W \\sim 30^o$, and bare fine structure constant around $\\alpha \\sim 1/150$. We consider the value of the scalar self coupling corresponding to bare Higgs mass around 150 GeV. The effective constraint potential for the zero momentum scalar field is used in order to investigate phenomena existing in the vicinity of the phase transition between the physical Higgs phase and the unphysical symmetric phase of the lattice model. This is the region of the phase diagram, where the continuum physics is to be approached. We compare the above mentioned effective potential (calculated in selected gauges) with the effective potential for the value of the scalar field at a fixed space - time point. We also calculate the renormalized fine structure constant using the correlator of Polyakov lines and compare it with the one - loop perturbative estimate.

  7. A New Vision Of Management: Full Potential Management Model

    Directory of Open Access Journals (Sweden)

    Yuka Fujimoto

    2010-11-01

    Full Text Available This paper establishes the Full Potential Management (FPM Model based upon the social model of disabilities coupled with principles of diversity management and disability-oriented human resource management. Despite the fact that the concept of management was once envisioned as having ‘value to society’ by improving the quality of life through efficient practices (Rimler, 1976, management literature has narrowly defined management as a means to gain increased productivity and achieve organizational goals, thus overlooking the social formation and implementation design for a better life (Diener & Seligman, 2004; Small, 2004; Whitley 1989. Based upon the diversity literature, we propose that social-oriented diversity management principles and practices are the key to transforming management concepts from achieving organizational potential to achieving social aims that maximize the potential and quality of life of each person.

  8. A constructive model potential method for atomic interactions

    Science.gov (United States)

    Bottcher, C.; Dalgarno, A.

    1974-01-01

    A model potential method is presented that can be applied to many electron single centre and two centre systems. The development leads to a Hamiltonian with terms arising from core polarization that depend parametrically upon the positions of the valence electrons. Some of the terms have been introduced empirically in previous studies. Their significance is clarified by an analysis of a similar model in classical electrostatics. The explicit forms of the expectation values of operators at large separations of two atoms given by the model potential method are shown to be equivalent to the exact forms when the assumption is made that the energy level differences of one atom are negligible compared to those of the other.

  9. Nonlocal Nambu-Jona-Lasinio model and chiral chemical potential

    CERN Document Server

    Frasca, Marco

    2016-01-01

    We derive the critical temperature in a nonlocal Nambu-Jona-Lasinio model with the presence of a chiral chemical potential. The model we consider uses a form factor derived from recent studies of the gluon propagator in Yang-Mills theory and has the property to fit in excellent way the form factor arising from the instanton liquid picture for the vacuum of the theory. Nambu-Jona-Lasinio model is derived form quantum chromodynamics providing all the constants of the theory without any need for fits. We show that the critical temperature in this case always exists and increases as the square of the chiral chemical potential. The expression we obtain for the critical temperature depends on the mass gap that naturally arises from Yang-Mills theory at low-energy as also confirmed by lattice computations.

  10. Potential of 3D City Models to assess flood vulnerability

    Science.gov (United States)

    Schröter, Kai; Bochow, Mathias; Schüttig, Martin; Nagel, Claus; Ross, Lutz; Kreibich, Heidi

    2016-04-01

    Vulnerability, as the product of exposure and susceptibility, is a key factor of the flood risk equation. Furthermore, the estimation of flood loss is very sensitive to the choice of the vulnerability model. Still, in contrast to elaborate hazard simulations, vulnerability is often considered in a simplified manner concerning the spatial resolution and geo-location of exposed objects as well as the susceptibility of these objects at risk. Usually, area specific potential flood loss is quantified on the level of aggregated land-use classes, and both hazard intensity and resistance characteristics of affected objects are represented in highly simplified terms. We investigate the potential of 3D City Models and spatial features derived from remote sensing data to improve the differentiation of vulnerability in flood risk assessment. 3D City Models are based on CityGML, an application scheme of the Geography Markup Language (GML), which represents the 3D geometry, 3D topology, semantics and appearance of objects on different levels of detail. As such, 3D City Models offer detailed spatial information which is useful to describe the exposure and to characterize the susceptibility of residential buildings at risk. This information is further consolidated with spatial features of the building stock derived from remote sensing data. Using this database a spatially detailed flood vulnerability model is developed by means of data-mining. Empirical flood damage data are used to derive and to validate flood susceptibility models for individual objects. We present first results from a prototype application in the city of Dresden, Germany. The vulnerability modeling based on 3D City Models and remote sensing data is compared i) to the generally accepted good engineering practice based on area specific loss potential and ii) to a highly detailed representation of flood vulnerability based on a building typology using urban structure types. Comparisons are drawn in terms of

  11. Suspects in criminal investigations of rape

    Directory of Open Access Journals (Sweden)

    Marinković Darko

    2014-01-01

    Full Text Available Investigations of sexual assaults mostly focus on victims and their credibility, which may cause lack of firm evidence in relation to suspects. Given the fact that the criminal offence of rape is characterised by a high incidence of false reports and accusations, frequently indicating specific persons as the perpetrators, certain caution is necessary in the investigation in order to avoid false accusations and/or convictions. As regards the personality of the rapist and motives for committing a forcible sexual act, certain types or rather certain categories of perpetrators can be distinguished, although it should be noted that a large number of rapists do not belong to one category only, but rather combine characteristics of several different types. During a criminal investigation it is of vital importance to differentiate between a rape as a surprise attack and a rape as abuse of trust, as they are compatible with the nature of the suspect's defence. The suspect shall be subjected to a forensic examination in the course of the investigation in order to find traces which prove vaginal, anal or oral penetration, coerced sexual intercourse and identity of the rapist. While conducting an interrogation of a suspected rapist, a crime investigating officer shall use either factual or emotional approach to his interviewee, depending on his psychological and motivational characteristics. In this regard, the factual approach is believed to be more efficient with anger rapists and sadistic rapists, whereas the compassionate approach gives good results with the gentlemen-rapists and partly with the power asserting rapists.

  12. Analysis of regulated suspected allergens in waters.

    Science.gov (United States)

    Becerril, Elias; Lamas, J Pablo; Sanchez-Prado, Lucia; Llompart, Maria; Lores, Marta; Garcia-Jares, Carmen

    2010-12-15

    Fragrance suspected allergens including those regulated by the EU Directive 76/768/EEC have been determined in different types of waters using solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). The procedure was based on headspace sampling (HS-SPME) using polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibers and has been optimized by an experimental design approach. The method performance has been studied showing good linearity (R ≥ 0.994) as well as good intra-day and inter-day precision (RSD ≤ 12%). Detection limits (S/N=3) ranged from 0.001 to 0.3 ng mL(-1). Reliability was demonstrated through the quantitative recoveries of the compounds in real water samples, including baby bathwaters, swimming pool waters, and wastewaters. The absence of matrix effects allowed quantification of the compounds by external aqueous calibration. The analysis of 35 samples of different types of waters showed the presence of suspected allergens in all the analyzed samples. All targets were found in the samples, with the exception of methyl eugenol and amyl cinnamic alcohol. Highest concentrations of suspected allergens were present in baby bathwaters, containing from 5 to 15 of the compounds at concentrations ranging from few pg mL(-1) to several hundreds of ng mL(-1).

  13. Magnetic resonance angiography in suspected cerebral vasculitis

    Energy Technology Data Exchange (ETDEWEB)

    Demaerel, Philippe; De Ruyter, Nele; Wilms, Guido [Department of Radiology, Universitair Ziekenhuis, KU Leuven, 3000, Leuven (Belgium); Maes, Frederik [Department of Medical Imaging Computing, Universitair Ziekenhuis, KU Leuven, 3000, Leuven (Belgium); Velghe, Beatrijs [Department of Radiology, Ziekenhuis Oost-Limburg, Schiepse Bos 6, 3600, Genk (Belgium)

    2004-06-01

    The purpose of this study was to determine the technical capacity and diagnostic accuracy of 3D time-of-flight magnetic resonance angiography (MRA) in suspected cerebral vasculitis in a retrospective analysis of MRA and digital subtraction angiography (DSA) in 14 young patients with clinical and/or radiological suspicion of cerebral vasculitis. A total of nine arteries were evaluated in each patient. Consensus review of DSA by three observers was the reference standard. The sensitivity for detecting a stenosis varied from 62 to 79% for MRA and from 76 to 94% for DSA, depending on the observer. The specificity for detecting a stenosis varied from 83 to 87% for MRA and from 83 to 97% for DSA. Using the criterion ''more than two stenoses in at least two separate vascular distributions'' to consider the examination as being true positive, the false-positive rates for MRA and DSA were comparable. MRA plays a role as the first angiographical examination in the diagnostic work-up of suspected cerebral vasculitis. When more than two stenoses in at least two separate vascular distributions are depicted on MRA, DSA is not expected to add a significant diagnostic contribution in a patient with suspected cerebral vasculitis. DSA remains necessary when MRA is normal or when less than three stenoses are seen. (orig.)

  14. Inflation with hyperbolic potential in the braneworld model

    Indian Academy of Sciences (India)

    Dilip Paul; Bikash Chandra Paul; Xin-He Meng

    2009-05-01

    In this paper we study inflationary dynamics with a scalar field in an inverse coshyperbolic potential in the braneworld model. We note that a sufficient inflation may be obtained with the potential considering slow-roll approximation in the high energy limit. We determine the minimum values of the initial inflaton field required to obtain sufficient inflation and also determine the relevant inflationary parameters. The numerical values of spectral index of the scalar perturbation spectrum are determined by varying the number of e-foldings for different initial values of the inflaton field. The result obtained here is in good agreement with the current observational limits.

  15. Stationary configurations of the Standard Model Higgs potential

    DEFF Research Database (Denmark)

    Iacobellis, Giuseppe; Masina, Isabella

    2016-01-01

    the stability of the SM electroweak minimum and ii) the value of the Higgs potential at a rising inflection point. We examine in detail and reappraise the experimental and theoretical uncertainties which plague their determination, finding that i) the stability of the SM is compatible with the present data...... at the 1.5σ level and ii) despite the large theoretical error plaguing the value of the Higgs potential at a rising inflection point, the application of such a configuration to models of primordial inflation displays a 3σ tension with the recent bounds on the tensor-to-scalar ratio of cosmological...

  16. Stationary configurations of the Standard Model Higgs potential

    DEFF Research Database (Denmark)

    Iacobellis, Giuseppe; Masina, Isabella

    2016-01-01

    the stability of the SM electroweak minimum and ii) the value of the Higgs potential at a rising inflection point. We examine in detail and reappraise the experimental and theoretical uncertainties which plague their determination, finding that i) the stability of the SM is compatible with the present data...... at the 1.5σ level and ii) despite the large theoretical error plaguing the value of the Higgs potential at a rising inflection point, the application of such a configuration to models of primordial inflation displays a 3σ tension with the recent bounds on the tensor-to-scalar ratio of cosmological...

  17. Study of interaction in silica glass via model potential approach

    Science.gov (United States)

    Mann, Sarita; Rani, Pooja

    2016-05-01

    Silica is one of the most commonly encountered substances in daily life and in electronics industry. Crystalline SiO2 (in several forms: quartz, cristobalite, tridymite) is an important constituent of many minerals and gemstones, both in pure form and mixed with related oxides. Cohesive energy of amorphous SiO2 has been investigated via intermolecular potentials i.e weak Van der Waals interaction and Morse type short-range interaction. We suggest a simple atom-atom based Van der Waals as well as Morse potential to find cohesive energy of glass. It has been found that the study of silica structure using two different model potentials is significantly different. Van der Waals potential is too weak (P.E =0.142eV/molecule) to describe the interaction between silica molecules. Morse potential is a strong potential, earlier given for intramolecular bonding, but if applied for intermolecular bonding, it gives a value of P.E (=-21.92eV/molecule) to appropriately describe the structure of silica.

  18. On the scalar potential of two-Higgs doublet models

    CERN Document Server

    Chakraborty, Indrani

    2015-01-01

    We perform a detailed analysis of the Two-Higgs Doublet Model (2HDM) potential. At the tree-level, the potential may accommodate more than one minima, one of them being the electroweak (EW) minimum where the universe lives. The parameter space allowed after the data from the Large Hadron Collider (LHC) came in almost excludes those cases where the EW vacuum is shallower than the second minimum. We extend the analysis by including terms in the 2HDM potential that break the $Z_2$ symmetry of the potential by dimension-4 operators and show that the conclusions remain unchanged. Furthermore, a one-loop analysis of the potential is performed for both cases, namely, where the $Z_2$ symmetry of the potential is broken by dimension-2 or dimension-4 operators. For quantitative analysis, we show our results for the Type-II 2HDM, qualitative results remaining the same for other 2HDMs. We find that the nature of the vacua from the tree-level analysis does not change; the EW vacuum still remains deeper.

  19. Strongly Interacting Matter at Finite Chemical Potential: Hybrid Model Approach

    Science.gov (United States)

    Srivastava, P. K.; Singh, C. P.

    2013-06-01

    Search for a proper and realistic equation of state (EOS) for strongly interacting matter used in the study of the QCD phase diagram still appears as a challenging problem. Recently, we constructed a hybrid model description for the quark-gluon plasma (QGP) as well as hadron gas (HG) phases where we used an excluded volume model for HG and a thermodynamically consistent quasiparticle model for the QGP phase. The hybrid model suitably describes the recent lattice results of various thermodynamical as well as transport properties of the QCD matter at zero baryon chemical potential (μB). In this paper, we extend our investigations further in obtaining the properties of QCD matter at finite value of μB and compare our results with the most recent results of lattice QCD calculation.

  20. Maxent modelling for predicting the potential distribution of Thai Palms

    DEFF Research Database (Denmark)

    Tovaranonte, Jantrararuk; Barfod, Anders S.; Overgaard, Anne Blach

    2011-01-01

    Increasingly species distribution models are being used to address questions related to ecology, biogeography and species conservation on global and regional scales. We used the maximum entropy approach implemented in the MAXENT programme to build a habitat suitability model for Thai palms based...... on presence data. The aim was to identify potential hot spot areas, assess the determinants of palm distribution ranges, and provide a firmer knowledge base for future conservation actions. We focused on a relatively small number of climatic, environmental and spatial variables in order to avoid...... overprediction of species distribution ranges. The models with the best predictive power were found by calculating the area under the curve (AUC) of receiver-operating characteristic (ROC). Here, we provide examples of contrasting predicted species distribution ranges as well as a map of modeled palm diversity...

  1. Coupled-channel optical model potential for rare earth nuclei

    CERN Document Server

    Herman, M; Palumbo, A; Dietrich, F S; Brown, D; Hoblit, S

    2013-01-01

    Inspired by the recent work by Dietrich et al., substantiating validity of the adiabatic assumption in coupled-channel calculations, we explore the possibility of generalizing a global spherical optical model potential (OMP) to make it usable in coupled-channel calculations on statically deformed nuclei. The generalization consists in adding the coupling of the ground state rotational band, deforming the potential by introducing appropriate quadrupole and hexadecupole deformation and correcting the OMP radius to preserve volume integral of the spherical OMP. We choose isotopes of three rare-earth elements (W, Ho, Gd), which are known to be nearly perfect rotors, to perform a consistent test of our conjecture on integrated cross sections as well as on angular distributions for elastic and inelastic neutron scattering. When doing this we employ the well-established Koning-Delaroche global spherical potential and experimentally determined deformations without any adjustments. We observe a dramatically improved a...

  2. Local random potentials of high differentiability to model the Landscape

    CERN Document Server

    Battefeld, Thorsten

    2015-01-01

    We generate random functions locally via a novel generalization of Dyson Brownian motion, such that the functions are in a desired differentiability class, while ensuring that the Hessian is a member of the Gaussian orthogonal ensemble (other ensembles might be chosen if desired). Potentials in such higher differentiability classes are required/desirable to model string theoretical landscapes, for instance to compute cosmological perturbations (e.g., smooth first and second derivatives for the power-spectrum) or to search for minima (e.g., suitable de Sitter vacua for our universe). Since potentials are created locally, numerical studies become feasible even if the dimension of field space is large (D ~ 100). In addition to the theoretical prescription, we provide some numerical examples to highlight properties of such potentials; concrete cosmological applications will be discussed in companion publications.

  3. Potential for Remotely Sensed Soil Moisture Data in Hydrologic Modeling

    Science.gov (United States)

    Engman, Edwin T.

    1997-01-01

    Many hydrologic processes display a unique signature that is detectable with microwave remote sensing. These signatures are in the form of the spatial and temporal distributions of surface soil moisture and portray the spatial heterogeneity of hydrologic processes and properties that one encounters in drainage basins. The hydrologic processes that may be detected include ground water recharge and discharge zones, storm runoff contributing areas, regions of potential and less than potential ET, and information about the hydrologic properties of soils and heterogeneity of hydrologic parameters. Microwave remote sensing has the potential to detect these signatures within a basin in the form of volumetric soil moisture measurements in the top few cm. These signatures should provide information on how and where to apply soil physical parameters in distributed and lumped parameter models and how to subdivide drainage basins into hydrologically similar sub-basins.

  4. Minimal model for short-time diffusion in periodic potentials.

    Science.gov (United States)

    Emary, Clive; Gernert, Robert; Klapp, Sabine H L

    2012-12-01

    We investigate the dynamics of a single, overdamped colloidal particle, which is driven by a constant force through a one-dimensional periodic potential. We focus on systems with large barrier heights where the lowest-order cumulants of the density field, that is, average position and the mean-squared displacement, show nontrivial (nondiffusive) short-time behavior characterized by the appearance of plateaus. We demonstrate that this "cage-like" dynamics can be well described by a discretized master equation model involving two states (related to two positions) within each potential valley. Nontrivial predictions of our approach include analytic expressions for the plateau heights and an estimate of the "de-caging time" obtained from the study of deviations from Gaussian behavior. The simplicity of our approach means that it offers a minimal model to describe the short-time behavior of systems with hindered dynamics.

  5. Modeling of Transmembrane Potential in Realistic Multicellular Structures before Electroporation.

    Science.gov (United States)

    Murovec, Tomo; Sweeney, Daniel C; Latouche, Eduardo; Davalos, Rafael V; Brosseau, Christian

    2016-11-15

    Many approaches for studying the transmembrane potential (TMP) induced during the treatment of biological cells with pulsed electric fields have been reported. From the simple analytical models to more complex numerical models requiring significant computational resources, a gamut of methods have been used to recapitulate multicellular environments in silico. Cells have been modeled as simple shapes in two dimensions as well as more complex geometries attempting to replicate realistic cell shapes. In this study, we describe a method for extracting realistic cell morphologies from fluorescence microscopy images to generate the piecewise continuous mesh used to develop a finite element model in two dimensions. The preelectroporation TMP induced in tightly packed cells is analyzed for two sets of pulse parameters inspired by clinical irreversible electroporation treatments. We show that high-frequency bipolar pulse trains are better, and more homogeneously raise the TMP of tightly packed cells to a simulated electroporation threshold than conventional irreversible electroporation pulse trains, at the expense of larger applied potentials. Our results demonstrate the viability of our method and emphasize the importance of considering multicellular effects in the numerical models used for studying the response of biological tissues exposed to electric fields. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  6. The Instanton-Dyon Liquid Model III: Finite Chemical Potential

    CERN Document Server

    Liu, Yizhuang; Zahed, Ismail

    2016-01-01

    We discuss an extension of the instanton-dyon liquid model that includes light quarks at finite chemical potential in the center symmetric phase. We develop the model in details for the case of SU_c(2)\\times SU_f(2) by mapping the theory on a 3-dimensional quantum effective theory. We analyze the different phases in the mean-field approximation. We extend this analysis to the general case of SU_c(N_c)\\times SU_f(N_f) and note that the chiral and diquark pairings are always comparable.

  7. Open flavour charmed mesons in a quantum chromodynamics potential model

    Indian Academy of Sciences (India)

    Krishna Kingkar Pathak; D K Choudhury

    2012-12-01

    We modify the mesonic wave function by using a short distance scale 0 in analogy with hydrogen atom and estimate the values of masses and decay constants of the open flavour charm mesons , $D_{s}$ and $B_{c}$ within the framework of a QCD potential model. We also calculate leptonic decay widths of these mesons to study branching ratios and lifetime. The results are in good agreement with experimental and other theoretical values.

  8. Structural properties of effective potential model by liquid state theories

    Institute of Scientific and Technical Information of China (English)

    Xiang Yuan-Tao; Andrej Jamnik; Yang Kai-Wei

    2010-01-01

    This paper investigates the structural properties of a model fluid dictated by an effective inter-particle oscillatory potential by grand canonical ensemble Monte Carlo (GCEMC) simulation and classical liquid state theories. The chosen oscillatory potential incorporates basic interaction terms used in modeling of various complex fluids which is composed of mesoscopic particles dispersed in a solvent bath, the studied structural properties include radial distribution function in bulk and inhomogeneous density distribution profile due to influence of several external fields. The GCEMC results are employed to test the validity of two recently proposed theoretical approaches in the field of atomic fluids. One is an Ornstein-Zernike integral equation theory approach; the other is a third order + second order perturbation density functional theory. Satisfactory agreement between the GCEMC simulation and the pure theories fully indicates the ready adaptability of the atomic fluid theories to effective model potentials in complex fluids, and classifies the proposed theoretical approaches as convenient tools for the investigation of complex fluids under the single component macro-fluid approximation.

  9. K- nuclear potentials from in-medium chirally motivated models

    Science.gov (United States)

    Cieplý, A.; Friedman, E.; Gal, A.; Gazda, D.; Mareš, J.

    2011-10-01

    A self-consistent scheme for constructing K- nuclear optical potentials from subthreshold in-medium K¯N s-wave scattering amplitudes is presented and applied to analysis of kaonic atoms data and to calculations of K- quasibound nuclear states. The amplitudes are taken from a chirally motivated meson-baryon coupled-channel model, both at the Tomozawa-Weinberg leading order and at the next to leading order. Typical kaonic atoms potentials are characterized by a real part -ReVK-chiral=85±5 MeV at nuclear matter density, in contrast to half this depth obtained in some derivations based on in-medium K¯N threshold amplitudes. The moderate agreement with data is much improved by adding complex ρ- and ρ2-dependent phenomenological terms, found to be dominated by ρ2 contributions that could represent K¯NN→YN absorption and dispersion, outside the scope of meson-baryon chiral models. Depths of the real potentials are then near 180 MeV. The effects of p-wave interactions are studied and found secondary to those of the dominant s-wave contributions. The in-medium dynamics of the coupled-channel model is discussed and systematic studies of K- quasibound nuclear states are presented.

  10. Probabilistic delay differential equation modeling of event-related potentials.

    Science.gov (United States)

    Ostwald, Dirk; Starke, Ludger

    2016-08-01

    "Dynamic causal models" (DCMs) are a promising approach in the analysis of functional neuroimaging data due to their biophysical interpretability and their consolidation of functional-segregative and functional-integrative propositions. In this theoretical note we are concerned with the DCM framework for electroencephalographically recorded event-related potentials (ERP-DCM). Intuitively, ERP-DCM combines deterministic dynamical neural mass models with dipole-based EEG forward models to describe the event-related scalp potential time-series over the entire electrode space. Since its inception, ERP-DCM has been successfully employed to capture the neural underpinnings of a wide range of neurocognitive phenomena. However, in spite of its empirical popularity, the technical literature on ERP-DCM remains somewhat patchy. A number of previous communications have detailed certain aspects of the approach, but no unified and coherent documentation exists. With this technical note, we aim to close this gap and to increase the technical accessibility of ERP-DCM. Specifically, this note makes the following novel contributions: firstly, we provide a unified and coherent review of the mathematical machinery of the latent and forward models constituting ERP-DCM by formulating the approach as a probabilistic latent delay differential equation model. Secondly, we emphasize the probabilistic nature of the model and its variational Bayesian inversion scheme by explicitly deriving the variational free energy function in terms of both the likelihood expectation and variance parameters. Thirdly, we detail and validate the estimation of the model with a special focus on the explicit form of the variational free energy function and introduce a conventional nonlinear optimization scheme for its maximization. Finally, we identify and discuss a number of computational issues which may be addressed in the future development of the approach.

  11. Re-modeling Chara action potential: II. The action potential form under salinity stress

    Directory of Open Access Journals (Sweden)

    Mary Jane Beilby

    2017-04-01

    Full Text Available In part I we established Thiel-Beilby model of the Chara action potential (AP. In part II the AP is investigated in detail at the time of saline stress. Even very short exposure of salt-sensitive Chara cells to artificial pond water with 50 mM NaCl (Saline APW modified the AP threshold and drastically altered the AP form. Detailed modeling of 14 saline APs from 3 cells established that both the Ca2+ pump and the Ca2+ channels on internal stores seem to be affected, with the changes sometimes cancelling and sometimes re-enforcing each other, leading to APs with long durations and very complex forms. The exposure to salinity offers further insights into AP mechanism and suggests future experiments. The prolonged APs lead to greater loss of chloride and potassium ions, compounding the effects of saline stress.

  12. Spatial Modelling of Solar energy Potential in Kenya

    Directory of Open Access Journals (Sweden)

    Francis Omondi Oloo

    2015-06-01

    Full Text Available Solar energy is one of the readily available renewable energy resources in the developing countries within the tropical region. Kenya is one of the countries which receive an average of approximately 6.5 sunshine hours in a single day throughout the year. However, there is slow adoption of solar energy resources in the country due to limited information on the spatial variability solar energy potential. This study aims at assessing the potential of photovoltaic solar energy in Kenya. The factors that influence incident solar radiation which were considered in this task included atmospheric transmissivity and topography. The influence of atmospheric transmissivity was factored in by modelling monthly transmissivity factors from a combination of cloud cover, diffuse ratios and the effect of altitude. The contribution of topography was included by applying hemispherical viewshed analysis to determine the amount of incident global radiation on the surface based on the orientation of the terrain. GIS concepts were used to integrate the spatial datasets from different themes. The results showed that, about 70% of the land area in Kenya has the potential of receiving approximately 5kWh/m2/day throughout the year. In outline, this work successfully assessed the spatio-temporal variability in the characteristics of solar energy potential in Kenya and can be used as a basis for policy support in the country.

  13. Modeling low impact development potential with hydrological response units.

    Science.gov (United States)

    Eric, Marija; Fan, Celia; Joksimovic, Darko; Li, James Y

    2013-01-01

    Evaluations of benefits of implementing low impact development (LID) stormwater management techniques can extend up to a watershed scale. This presents a challenge for representing them in watershed models, since they are typically orders of magnitude smaller in size. This paper presents an approach that is focused on trying to evaluate the benefits of implementing LIDs on a lot level. The methodology uses the concept of urban hydrological response Unit and results in developing and applying performance curves that are a function of lot properties to estimate the potential benefit of large-scale LID implementation. Lot properties are determined using a municipal geographic information system database and processed to determine groups of lots with similar properties. A representative lot from each group is modeled over a typical rainfall year using USEPA Stormwater Management Model to develop performance functions that relate the lot properties and the change in annual runoff volume and corresponding phosphorus loading with different LIDs implemented. The results of applying performance functions on all urban areas provide the potential locations, benefit and cost of implementation of all LID techniques, guiding future decisions for LID implementation by watershed area municipalities.

  14. Three-nucleon bound states using realistic potential models

    Science.gov (United States)

    Nogga, A.; Kievsky, A.; Kamada, H.; Glöckle, W.; Marcucci, L. E.; Rosati, S.; Viviani, M.

    2003-03-01

    The bound states of 3H and 3He have been calculated by using the Argonne v18 plus the Urbana IX three-nucleon potential. The isospin T=3/2 state have been included in the calculations as well as the n-p mass difference. The 3H-3He mass difference has been evaluated through the charge-dependent terms explicitly included in the two-body potential. The calculations have been performed using two different methods: the solution of the Faddeev equations in momentum space and the expansion on the correlated hyperspherical harmonic basis. The results are in agreement within 0.1% and can be used as benchmark tests. Results for the charge-dependent Bonn interaction in conjunction with the Tucson-Melbourne three-nucleon force are also presented. It is shown that the 3H and 3He binding energy difference can be predicted model independently.

  15. The three-nucleon bound state using realistic potential models

    CERN Document Server

    Nogga, A; Kamada, H; Glöckle, W; Marcucci, L E; Rosati, S; Viviani, M

    2003-01-01

    The bound states of $^3$H and $^3$He have been calculated using the Argonne $v_{18}$ plus the Urbana three-nucleon potential. The isospin $T=3/2$ state have been included in the calculations as well as the $n$-$p$ mass difference. The $^3$H-$^3$He mass difference has been evaluated through the charge dependent terms explicitly included in the two-body potential. The calculations have been performed using two different methods: the solution of the Faddeev equations in momentum space and the expansion on the correlated hyperspherical harmonic basis. The results are in agreement within 0.1% and can be used as benchmark tests. Results for the CD-Bonn interaction are also presented. It is shown that the $^3$H and $^3$He binding energy difference can be predicted model independently.

  16. Animal models of protein allergenicity: potential benefits, pitfalls and challenges.

    Science.gov (United States)

    Dearman, R J; Kimber, I

    2009-04-01

    Food allergy is an important health issue. With an increasing interest in novel foods derived from transgenic crop plants, there is a growing need for the development of approaches suitable for the characterization of the allergenic potential of proteins. There are methods available currently (such as homology searches and serological testing) that are very effective at identifying proteins that are likely to cross-react with known allergens. However, animal models may play a role in the identification of truly novel proteins, such as bacterial or fungal proteins, that have not been experienced previously in the diet. We consider here the potential benefits, pitfalls and challenges of the selection of various animal models, including the mouse, the rat, the dog and the neonatal swine. The advantages and disadvantages of various experimental end-points are discussed, including the measurement of specific IgE by ELISA, Western blotting or functional tests such as the passive cutaneous anaphylaxis assay, and the assessment of challenge-induced clinical symptoms in previously sensitized animals. The experimental variables of route of exposure to test proteins and the incorporation of adjuvant to increase the sensitivity of the responses are considered also. It is important to emphasize that currently none of these approaches has been validated for the purposes of hazard identification in the context of a safety assessment. However, the available evidence suggests that the judicious use of an accurate and robust animal model could provide important additional data that would contribute significantly to the assessment of the potential allergenicity of novel proteins.

  17. Velocity potential formulations of highly accurate Boussinesq-type models

    DEFF Research Database (Denmark)

    Bingham, Harry B.; Madsen, Per A.; Fuhrman, David R.

    2009-01-01

    processes on the weather side of reflective structures. Coast. Eng. 53, 929-945). An exact infinite series solution for the potential is obtained via a Taylor expansion about an arbitrary vertical position z=(z) over cap. For practical implementation however, the solution is expanded based on a slow...... variation of (z) over cap and terms are retained to first-order. With shoaling enhancement, the new models obtain a comparable accuracy in linear shoaling to the original velocity formulation. General consistency relations are also derived which are convenient for verifying that the differential operators...

  18. Exact Solution in Chaotic Inflation Model with Potential Minima

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-Fu

    2001-01-01

    Taking the cosmological expansion rate directly as a function of field , H = H( ), we present a new exact solution to Einstein's equations that describe the evolution of cosmological chaotic inflation model. The inflation is driven by the evolution of scalar field with inflation potential V( ) = λ 2 v2)2.8 ( 2- 2)2.The spectral indices of the scalar density ns and gravitational wave fluctuations ng are computed. The value of ns lies well inside the limits set by the cosmic background explorer satellite.

  19. Exact Solution in Chaotic Inflation Model with Negative Potential

    Institute of Scientific and Technical Information of China (English)

    王文福

    2003-01-01

    New exact solution to the Einstein equations that describe the evolution of cosmological chaotic inflation model is derived. The inflation is driven by the evolution of scalar field with negative potential V( )=-Vo +1/2m2ψ2.This includes the solution which is exponential inflation for ψo >ψ>ψf , and then develops smoothly towards the radiation-like evolution for ψ<ψf. The spectral indices of the scalar density ns and the gravitational wave fluctuations ng are computed. The value of ns lies well inside the limits set by the cosmic background explorer satellite.

  20. Phase lagging model of brain response to external stimuli - modeling of single action potential

    CERN Document Server

    Seetharaman, Karthik; Kulish, Vladimir V

    2012-01-01

    In this paper we detail a phase lagging model of brain response to external stimuli. The model is derived using the basic laws of physics like conservation of energy law. This model eliminates the paradox of instantaneous propagation of the action potential in the brain. The solution of this model is then presented. The model is further applied in the case of a single neuron and is verified by simulating a single action potential. The results of this modeling are useful not only for the fundamental understanding of single action potential generation, but also they can be applied in case of neuronal interactions where the results can be verified against the real EEG signal.

  1. Pressure wave model for action potential propagation in excitable cells

    CERN Document Server

    Rvachev, M M

    2003-01-01

    Speed of propagation of small-amplitude pressure waves through the cytoplasmic interior of myelinated and unmyelinated axons of different diameters is theoretically estimated and is found to generally agree with the action potential (AP) conduction velocities. This remarkable coincidence allows to surmise a model in which AP spread along axon is propelled not by straggling ionic currents as in the widely accepted local circuit theory, but by mechanoactivation of the membrane ion channels by a traveling pressure pulse. Hydraulic pulses propagating in the viscous axoplasm are calculated to decay over ~1 mm distances, and it is further hypothesized that it is the role of influxing during the AP calcium ions to activate membrane skeletal protein network attached to the membrane cytoplasmic side for a brief radial contraction amplifying the pressure pulse and preventing its decay. The model correctly predicts that the AP conduction velocity should vary as the one-half power of axon diameter for large unmyelinated ...

  2. Generalized Skyrme model with the loosely bound potential

    CERN Document Server

    Gudnason, Sven Bjarke; Ma, Nana

    2016-01-01

    We study a generalization of the loosely bound Skyrme model which consists of the Skyrme model with a sixth-order derivative term and the second-order loosely bound potential. We use the rational map approximation for the 4-Skyrmion and calculate the binding energy and estimate the systematic error in using the latter approximation. In the parameter space that we can explore within the rational map approximation, we find classical binding energies as low as 1.8% and once taking into account the contribution from spin-isospin quantization we obtain binding energies as low as 5.3%. We also calculate the contribution from the sixth-order derivative term to the electric charge density and axial coupling.

  3. Learning about the Milky Way potential with generative stream models

    Science.gov (United States)

    McMillan, Paul

    2015-08-01

    Streams are formed when satellites of a galaxy are pulled apart by tidal forces and the stars then drift apart because they are placed on different orbits. Therefore it is the difference between the orbits that determines the shape of the stream (rather than the stream nearly following a single orbit). This means that a good model of the structure of a stream can be defined in terms of orbital frequencies and angle coordinates.I’ll talk about a new method for creating generative models of streams based on this insight. Given that the orbital frequencies are directly related to the actions, the method of torus modelling (which finds the orbits corresponding to a given value of actions) is ideally suited to the problem. I’ll show results from a new method that interpolates between orbits (tori), to rapidly generate stream models that can be used to determine the gravitational potential that the stream is moving in. This method has now been made publicly available.

  4. Potential biodefense model applications for portable chlorine dioxide gas production.

    Science.gov (United States)

    Stubblefield, Jeannie M; Newsome, Anthony L

    2015-01-01

    Development of decontamination methods and strategies to address potential infectious disease outbreaks and bioterrorism events are pertinent to this nation's biodefense strategies and general biosecurity. Chlorine dioxide (ClO2) gas has a history of use as a decontamination agent in response to an act of bioterrorism. However, the more widespread use of ClO2 gas to meet current and unforeseen decontamination needs has been hampered because the gas is too unstable for shipment and must be prepared at the application site. Newer technology allows for easy, onsite gas generation without the need for dedicated equipment, electricity, water, or personnel with advanced training. In a laboratory model system, 2 unique applications (personal protective equipment [PPE] and animal skin) were investigated in the context of potential development of decontamination protocols. Such protocols could serve to reduce human exposure to bacteria in a decontamination response effort. Chlorine dioxide gas was capable of reducing (2-7 logs of vegetative and spore-forming bacteria), and in some instances eliminating, culturable bacteria from difficult to clean areas on PPE facepieces. The gas was effective in eliminating naturally occurring bacteria on animal skin and also on skin inoculated with Bacillus spores. The culturable bacteria, including Bacillus spores, were eliminated in a time- and dose-dependent manner. Results of these studies suggested portable, easily used ClO2 gas generation systems have excellent potential for protocol development to contribute to biodefense strategies and decontamination responses to infectious disease outbreaks or other biothreat events.

  5. ADVANCED DEVELOPMENT MODEL OF TERRITORIAL HUMAN RESOURCES POTENTIAL

    Directory of Open Access Journals (Sweden)

    Alexander G. Моkronosov

    2015-03-01

    Full Text Available The aim of the study is to substantiate the need for eliminating the excessive spatial polarization of territorial socio-economic development as a necessary condition for advanced development of human resources potential. The authors explore the basic problems and contradictions of modern regional and local labor markets in Russia. Based on generalization and systematization of foreign and domestic research outcomes, the paper reveals the main condition for eliminating the territorial polarization threats, which implies formation of a new institutional environment in order to provide co-operation of participants in the territorial interest zone in personnel training and new jobs creating.The research findings demonstrate the increased disproportions between the workforce and labor markets of municipal formations in Sverdlovsk region, and emphasize the need for territorial industrial educational clusters maximizing the network co-operation of the involved parties.The scientific novelty combines adaptation of theoretical concepts of the “new economic geography” applied to reorganization processes in the Russian economy; and elaboration of the cluster model of advanced development of territorial human resources potential by means of territorial centers coordinating the interests of administration, business society, and households.Practical significance of the research results is related to facilitating the administrative efficiency of regional and municipal formations, employers, territorial employment centers, and thereby the advanced development of human resources potential.

  6. ADVANCED DEVELOPMENT MODEL OF TERRITORIAL HUMAN RESOURCES POTENTIAL

    Directory of Open Access Journals (Sweden)

    Alexander G. Моkronosov

    2014-01-01

    Full Text Available The aim of the study is to substantiate the need for eliminating the excessive spatial polarization of territorial socio-economic development as a necessary condition for advanced development of human resources potential. The authors explore the basic problems and contradictions of modern regional and local labor markets in Russia. Based on generalization and systematization of foreign and domestic research outcomes, the paper reveals the main condition for eliminating the territorial polarization threats, which implies formation of a new institutional environment in order to provide co-operation of participants in the territorial interest zone in personnel training and new jobs creating.The research findings demonstrate the increased disproportions between the workforce and labor markets of municipal formations in Sverdlovsk region, and emphasize the need for territorial industrial educational clusters maximizing the network co-operation of the involved parties.The scientific novelty combines adaptation of theoretical concepts of the “new economic geography” applied to reorganization processes in the Russian economy; and elaboration of the cluster model of advanced development of territorial human resources potential by means of territorial centers coordinating the interests of administration, business society, and households.Practical significance of the research results is related to facilitating the administrative efficiency of regional and municipal formations, employers, territorial employment centers, and thereby the advanced development of human resources potential.

  7. Scalar potential model of redshift and discrete redshift

    CERN Document Server

    Hodge, J C

    2006-01-01

    On the galactic scale the universe is inhomogeneous and redshift $z$ is occasionally less than zero. A scalar potential model (SPM) that links the galaxy scale $z$ to the cosmological scale $z$ of the Hubble Law is postulated. Several differences among galaxy types suggest that spiral galaxies are Sources and that early type, lenticular, and irregular galaxies are Sinks of a scalar potential field. The morphology-radius and the intragalactic medium cluster observations support the movement of matter from Source galaxies to Sink galaxies. A cell structure of galaxy groups and clusters is proposed to resolve a paradox concerning the scalar potential like the Olber's paradox concerning light. For the sample galaxies, the ratio of the luminosity of Source galaxies to the luminosity of Sink galaxies approaches $2.7 \\pm 0.1$. An equation is derived from sample data, which is anisotropic and inhomogeneous, relating $z$ of and the distance $D$ to galaxies. The calculated $z$ has a correlation coefficient of 0.88 with...

  8. Evaluation of bio-energy potential using world energy models; Sekai energy model ni yoru bio energy no potential hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Fujino, J.; Yamaji, K. [The University of Tokyo, Tokyo (Japan); Yamamoto, H. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1997-01-30

    Bio-energy potential is evaluated using world energy models. The world energy model is a dynamic model by which the total cost of energy systems between 1995 and 2055 can be minimized on the basis of the optimization type world energy demand and supply model. For the given utilization costs of transportation, recovery and planting, the utilization of bio-energy is promoted even under the cost minimization condition. However, the utilization amount varies in a wide range by changing the utilization costs. Among conversion technologies of bio-energy, it is biomass liquefaction that provides the largest utilization amount. Thermal demand, direct combustion for power generation, and biomass gasification follow to the above. Biomass-integrated gasifier/gas turbine (BIG/GT) is to be used up to 2020. It is not to be used after 2030, due to the complete shift to the biomass liquefaction. For a model including the utilization of fast breeder after 2030, the utilization amount of bio-energy is not to change. Competition with food and land utilization is to be investigated. 11 refs., 19 figs., 4 tabs.

  9. Evaluation of bio-energy potential using world energy models; Sekai energy model ni yoru bio energy no potential hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Fujino, J.; Yamaji, K. [The University of Tokyo, Tokyo (Japan); Yamamoto, H. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1997-01-30

    Bio-energy potential is evaluated using world energy models. The world energy model is a dynamic model by which the total cost of energy systems between 1995 and 2055 can be minimized on the basis of the optimization type world energy demand and supply model. For the given utilization costs of transportation, recovery and planting, the utilization of bio-energy is promoted even under the cost minimization condition. However, the utilization amount varies in a wide range by changing the utilization costs. Among conversion technologies of bio-energy, it is biomass liquefaction that provides the largest utilization amount. Thermal demand, direct combustion for power generation, and biomass gasification follow to the above. Biomass-integrated gasifier/gas turbine (BIG/GT) is to be used up to 2020. It is not to be used after 2030, due to the complete shift to the biomass liquefaction. For a model including the utilization of fast breeder after 2030, the utilization amount of bio-energy is not to change. Competition with food and land utilization is to be investigated. 11 refs., 19 figs., 4 tabs.

  10. The comparative capacity of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and MMPI-2 Restructured Form (MMPI-2-RF) validity scales to detect suspected malingering in a disability claimant sample.

    Science.gov (United States)

    Chmielewski, Michael; Zhu, Jiani; Burchett, Danielle; Bury, Alison S; Bagby, R Michael

    2017-02-01

    The current study expands on past research examining the comparative capacity of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher et al., 2001) and MMPI-2 Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008/2011) overreporting validity scales to detect suspected malingering, as assessed by the Miller Forensic Assessment of Symptoms Test (M-FAST; Miller, 2001), in a sample of public insurance disability claimants (N = 742) who were considered to have potential incentives to malinger. Results provide support for the capacity of both the MMPI-2 and the MMPI-2-RF overreporting validity scales to predict suspected malingering of psychopathology. The MMPI-2-RF overreporting validity scales proved to be modestly better predictors of suspected psychopathology malingering-compared with the MMPI-2 overreporting scales-in dimensional predictive models and categorical classification accuracy analyses. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  11. A unified classification model for modeling of seismic liquefaction potential of soil based on CPT.

    Science.gov (United States)

    Samui, Pijush; Hariharan, R

    2015-07-01

    The evaluation of liquefaction potential of soil due to an earthquake is an important step in geosciences. This article examines the capability of Minimax Probability Machine (MPM) for the prediction of seismic liquefaction potential of soil based on the Cone Penetration Test (CPT) data. The dataset has been taken from Chi-Chi earthquake. MPM is developed based on the use of hyperplanes. It has been adopted as a classification tool. This article uses two models (MODEL I and MODEL II). MODEL I employs Cone Resistance (q c) and Cyclic Stress Ratio (CSR) as input variables. q c and Peak Ground Acceleration (PGA) have been taken as inputs for MODEL II. The developed MPM gives 100% accuracy. The results show that the developed MPM can predict liquefaction potential of soil based on q c and PGA.

  12. Analysing regenerative potential in zebrafish models of congenital muscular dystrophy.

    Science.gov (United States)

    Wood, A J; Currie, P D

    2014-11-01

    The congenital muscular dystrophies (CMDs) are a clinically and genetically heterogeneous group of muscle disorders. Clinically hypotonia is present from birth, with progressive muscle weakness and wasting through development. For the most part, CMDs can mechanistically be attributed to failure of basement membrane protein laminin-α2 sufficiently binding with correctly glycosylated α-dystroglycan. The majority of CMDs therefore arise as the result of either a deficiency of laminin-α2 (MDC1A) or hypoglycosylation of α-dystroglycan (dystroglycanopathy). Here we consider whether by filling a regenerative medicine niche, the zebrafish model can address the present challenge of delivering novel therapeutic solutions for CMD. In the first instance the readiness and appropriateness of the zebrafish as a model organism for pioneering regenerative medicine therapies in CMD is analysed, in particular for MDC1A and the dystroglycanopathies. Despite the recent rapid progress made in gene editing technology, these approaches have yet to yield any novel zebrafish models of CMD. Currently the most genetically relevant zebrafish models to the field of CMD, have all been created by N-ethyl-N-nitrosourea (ENU) mutagenesis. Once genetically relevant models have been established the zebrafish has several important facets for investigating the mechanistic cause of CMD, including rapid ex vivo development, optical transparency up to the larval stages of development and relative ease in creating transgenic reporter lines. Together, these tools are well suited for use in live-imaging studies such as in vivo modelling of muscle fibre detachment. Secondly, the zebrafish's contribution to progress in effective treatment of CMD was analysed. Two approaches were identified in which zebrafish could potentially contribute to effective therapies. The first hinges on the augmentation of functional redundancy within the system, such as upregulating alternative laminin chains in the candyfloss

  13. Modeling of movement-related potentials using a fractal approach.

    Science.gov (United States)

    Uşakli, Ali Bülent

    2010-06-01

    In bio-signal applications, classification performance depends greatly on feature extraction, which is also the case for electroencephalogram (EEG) based applications. Feature extraction, and consequently classification of EEG signals is not an easy task due to their inherent low signal-to-noise ratios and artifacts. EEG signals can be treated as the output of a non-linear dynamical (chaotic) system in the human brain and therefore they can be modeled by their dimension values. In this study, the variance fractal dimension technique is suggested for the modeling of movement-related potentials (MRPs). Experimental data sets consist of EEG signals recorded during the movements of right foot up, lip pursing and a simultaneous execution of these two tasks. The experimental results and performance tests show that the proposed modeling method can efficiently be applied to MRPs especially in the binary approached brain computer interface applications aiming to assist severely disabled people such as amyotrophic lateral sclerosis patients in communication and/or controlling devices.

  14. Molecular model of the action potential sodium channel.

    Science.gov (United States)

    Guy, H R; Seetharamulu, P

    1986-01-01

    Secondary and tertiary structural models of sodium channel transmembrane segments were developed from its recently determined primary sequence in Electrophorus electricus. The model has four homologous domains, and each domain has eight homologous transmembrane segments, S1 through S8. Each domain contains three relatively apolar segments (S1, S2 and S3) and two very apolar segments (S5 and S8), all postulated to be transmembrane alpha-helices. S4 segments have positively charged residues, mainly arginines, at every third residue. The model channel lining is formed by four S4 transmembrane alpha-helices and four negatively charged S7 segments. S7 segments are postulated to be short, partially transmembrane amphipathic alpha-helices in three domains and a beta-strand in the last domain. S7 segments are preceded by short apolar segments (S6) postulated to be alpha-helices in three domains and a beta-strand in the last domain. Positively charged side chains of S4 form salt bridges with negatively charged side chains on S7 and near the ends of S1 and S3. Putative extracellular segments that contain 5 of the 10 potential N-glycosylation sites link S5 to S6. Channel activation may involve a 'helical screw' mechanism in which S4 helices rotate around their axes as they move toward the extracellular surface. Images PMID:2417247

  15. Dynamics of warm Chaplygin gas inflationary models with quartic potential

    Energy Technology Data Exchange (ETDEWEB)

    Jawad, Abdul; Rani, Shamaila [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan); Butt, Sadaf [Lahore Leads University, Department of Mathematics, Lahore (Pakistan); Kinnaird College for Women, Department of Mathematics, Lahore (Pakistan)

    2016-05-15

    Warm inflationary universe models in the context of the generalized Chaplygin gas, the modified Chaplygin gas, and the generalized cosmic Chaplygin gas are being studied. The dissipative coefficient of the form Γ ∝ T, and the weak and the strong dissipative regimes are being considered. We use the quartic potential, (λ{sub *}φ{sup 4})/(4), which is ruled out by current data in cold inflation but in our models by analysis it is seen to be in agreement with the WMAP9 and the latest Planck data. In these scenarios, the power spectrum, the spectral index, and the tensor-to-scalar ratio are being examined in the slow-roll approximation. We show the dependence of the tensor-scalar ratio r on the spectral index n{sub s} and observe that the range of the tensor-scalar ratio is r < 0.05 in the generalized Chaplygin gas, r < 0.15 in the modified Chaplygin gas, and r < 0.12 in the generalized cosmic Chaplygin gas models. Our results are in agreement with recent observational data like WMAP9 and the latest Planck data. (orig.)

  16. Capsule endoscopy in suspected small bowel Crohn's disease: Economic impact of disease diagnosis and treatment

    Institute of Scientific and Technical Information of China (English)

    Jonathan A Leighton; Ian M Gralnek; Randel E Richner; Michael J Lacey; Frank J Papatheofanis

    2009-01-01

    AIM: To model clinical and economic benefits of capsule endoscopy (CE) compared to ileo-colonoscopy and small bowel follow-through (SBFT) for evaluation of suspected Crohn's disease (CD).METHODS: Using decision analytic modeling, total and yearly costs of diagnostic work-up for suspected CD were calculated, including procedure-related adverse events,hospitalizations, office visits, and medications. The model compared CE to SBFT following ileo-colonoscopy and secondarily compared CE to SBFT for initial evaluation.RESULTS: Aggregate charges for newly diagnosed,medically managed patients are approximately $8295.Patients requiring aggressive medical management costs are $29 508; requiring hospitalization, $49 074.At sensitivity > 98.7% and specificity of > 86.4%, CE is less costly than SBFT.CONCLUSION: Costs of CE for diagnostic evaluation of suspected CD is comparable to SBFT and may be used immediately following ileo-colonoscopy.

  17. The extended Lennard-Jones potential energy function: A simpler model for direct-potential-fit analysis

    Science.gov (United States)

    Hajigeorgiou, Photos G.

    2016-12-01

    An analytical model for the diatomic potential energy function that was recently tested as a universal function (Hajigeorgiou, 2010) has been further modified and tested as a suitable model for direct-potential-fit analysis. Applications are presented for the ground electronic states of three diatomic molecules: oxygen, carbon monoxide, and hydrogen fluoride. The adjustable parameters of the extended Lennard-Jones potential model are determined through nonlinear regression by fits to calculated rovibrational energy term values or experimental spectroscopic line positions. The model is shown to lead to reliable, compact and simple representations for the potential energy functions of these systems and could therefore be classified as a suitable and attractive model for direct-potential-fit analysis.

  18. Global flow of the Higgs potential in a Yukawa model

    CERN Document Server

    Borchardt, Julia; Sondenheimer, René

    2016-01-01

    We study the renormalization flow of the Higgs potential as a function of both field amplitude and energy scale. This overcomes limitations of conventional techniques that rely, e.g., on an identification of field amplitude and RG scale, or on local field expansions. Using a Higgs-Yukawa model with discrete chiral symmetry as an example, our global flows in field space clarify the origin of possible meta-stabilities, the fate of the pseudo-stable phase, and provide new information about the renormalization of the tunnel barrier. Our results confirm the relaxation of the lower bound for the Higgs mass in the presence of more general microscopic interactions (higher-dimensional operators) to a high quantitative accuracy.

  19. Global flow of the Higgs potential in a Yukawa model

    Energy Technology Data Exchange (ETDEWEB)

    Borchardt, Julia [Friedrich-Schiller-Universitaet Jena, Theoretisch-Physikalisches Institut, Jena (Germany); Friedrich Schiller University Jena, Abbe Center of Photonics, Jena (Germany); Gies, Holger [Friedrich-Schiller-Universitaet Jena, Theoretisch-Physikalisches Institut, Jena (Germany); Friedrich Schiller University Jena, Abbe Center of Photonics, Jena (Germany); Helmholtz-Institut Jena, Jena (Germany); Sondenheimer, Rene [Friedrich-Schiller-Universitaet Jena, Theoretisch-Physikalisches Institut, Jena (Germany)

    2016-08-15

    We study the renormalization flow of the Higgs potential as a function of both field amplitude and energy scale. This overcomes limitations of conventional techniques that rely, e.g., on an identification of field amplitude and RG scale, or on local field expansions. Using a Higgs-Yukawa model with discrete chiral symmetry as an example, our global flows in field space clarify the origin of possible metastabilities, the fate of the pseudo-stable phase, and provide new information as regards the renormalization of the tunnel barrier. Our results confirm the relaxation of the lower bound for the Higgs mass in the presence of more general microscopic interactions (higher-dimensional operators) to a high quantitative accuracy. (orig.)

  20. Harnessing Data Flow and Modelling Potentials for Sustainable Development

    Directory of Open Access Journals (Sweden)

    Kassim S Mwitondi

    2012-12-01

    Full Text Available Tackling the global challenges relating to health, poverty, business, and the environment is heavily dependent on the flow and utilisation of data. However, while enhancements in data generation, storage, modelling, dissemination, and the related integration of global economies and societies are fast transforming the way we live and interact, the resulting dynamic, globalised, information society remains digitally divided. On the African continent in particular, this division has resulted in a gap between the knowledge generation and its transformation into tangible products and services. This paper proposes some fundamental approaches for a sustainable transformation of data into knowledge for the purpose of improving the people's quality of life. Its main strategy is based on a generic data sharing model providing access to data utilising and generating entities in a multi-disciplinary environment. It highlights the great potentials in using unsupervised and supervised modelling in tackling the typically predictive-in-nature challenges we face. Using both simulated and real data, the paper demonstrates how some of the key parameters may be generated and embedded in models to enhance their predictive power and reliability. The paper's conclusions include a proposed implementation framework setting the scene for the creation of decision support systems capable of addressing the key issues in society. It is expected that a sustainable data flow will forge synergies among the private sector, academic, and research institutions within and among countries. It is also expected that the paper's findings will help in the design and development of knowledge extraction from data in the wake of cloud computing and, hence, contribute towards the improvement in the people's overall quality of life. To avoid running high implementation costs, selected open source tools are recommended for developing and sustaining the system.

  1. Indirect Global Warming Potentials of Halons Using Atmospheric Models

    Science.gov (United States)

    Youn, D.; Patten, K. O.; Wuebbles, D. J.

    2007-05-01

    Emission of bromochlorofluorocarbons, or Halons, results in stratospheric ozone depletion. This leads to cooling of the climate system in the opposite direction to direct warming contribution of the Halons as greenhouse gases. This cooling is a key indirect effect of Halons on radiative forcing or climate. The Global Warming Potential (GWP) is a relative index used to compare the climate impact of an emitted greenhouse gas, relative to an equal amount of carbon dioxide. Until now, indirect GWPs have been calculated based on the concept of Equivalent Effective Stratospheric Chlorine (EESC), which oversimplifies the complex processes in the atmosphere. As a step towards obtaining indirect GWPs through a more robust approach, 2-D and 3-D global chemical transport models (CTM) were used as the computational tool to derive more realistic ozone changes caused by pulse perturbation of Halons at the surface. Indirect GWPs of Halon-1211 and -1301 for a 100-year time horizon were explicitly calculated based on the University of Illinois at Urbana-Champaign (UIUC) 2-D global CTM and radiative transport model (RTM) and the 3-D CTM, MOZART-3.1. The 2-D and 3-D model simulations show acceptable temporal variations in the atmosphere as well as derived lifetimes and direct GWP values of the Halons. The 2-D model-based indirect GWPs for a 100-year horizon are -16,294 for Halon-1211 and -33,648 for Halon-1301. 3-D indirect GWP for Halon-1211 is -18,216. The indirect GWPs for Halon-1211 presented here are much smaller than previous published results using the previous simplified appraoch.

  2. Diagnosis of suspected venous thromboembolic disease in pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Scarsbrook, A.F. [Department of Radiology, Churchill Hospital, Oxford Radcliffe NHS Trust, Headington, Oxford (United Kingdom); Evans, A.L. [Department of Radiology, Churchill Hospital, Oxford Radcliffe NHS Trust, Headington, Oxford (United Kingdom); Owen, A.R. [Department of Radiology, Churchill Hospital, Oxford Radcliffe NHS Trust, Headington, Oxford (United Kingdom); Gleeson, F.V. [Department of Radiology, Churchill Hospital, Oxford Radcliffe NHS Trust, Headington, Oxford (United Kingdom)]. E-mail: fergus.gleeson@radiology.oxford.ac.uk

    2006-01-15

    Venous thromboembolic disease is a leading cause of maternal mortality during pregnancy. Early and accurate radiological diagnosis is essential as anticoagulation is not without risk and clinical diagnosis is unreliable. Although the disorder is potentially treatable, unnecessary treatment should be avoided. Most of the diagnostic imaging techniques involve ionizing radiation which exposes both the mother and fetus to finite radiation risks. There is a relative lack of evidence in the literature to guide clinicians and radiologists on the most appropriate method of assessing this group of patients. This article will review the role of imaging of suspected venous thromboembolic disease in pregnant patients, highlight contentious issues such as radiation risk, intravenous contrast use in pregnancy and discuss the published guidelines, as well as suggesting an appropriate imaging algorithm based on the available evidence.

  3. Can atom-surface potential measurements test atomic structure models?

    Science.gov (United States)

    Lonij, Vincent P A; Klauss, Catherine E; Holmgren, William F; Cronin, Alexander D

    2011-06-30

    van der Waals (vdW) atom-surface potentials can be excellent benchmarks for atomic structure calculations. This is especially true if measurements are made with two different types of atoms interacting with the same surface sample. Here we show theoretically how ratios of vdW potential strengths (e.g., C₃(K)/C₃(Na)) depend sensitively on the properties of each atom, yet these ratios are relatively insensitive to properties of the surface. We discuss how C₃ ratios depend on atomic core electrons by using a two-oscillator model to represent the contribution from atomic valence electrons and core electrons separately. We explain why certain pairs of atoms are preferable to study for future experimental tests of atomic structure calculations. A well chosen pair of atoms (e.g., K and Na) will have a C₃ ratio that is insensitive to the permittivity of the surface, whereas a poorly chosen pair (e.g., K and He) will have a ratio of C₃ values that depends more strongly on the permittivity of the surface.

  4. Cortical capillary dysfunction in patients suspected of Alzheimer’s disease

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Gyldensted, Louise; Nagenthiraja, Kartheeban

    Vascular risk factors are suspected to play a role in the etiology of Alzheimer’s disease. Recently, a model that relates capillary dysfunction to the development of AD was proposed[1]. The model predicts that capillary dysfunction in form of increased capillary transit time heterogeneity (CTH...

  5. Asparaginase Potentiates Glucocorticoid-Induced Osteonecrosis in a Mouse Model.

    Science.gov (United States)

    Liu, Chengcheng; Janke, Laura J; Kawedia, Jitesh D; Ramsey, Laura B; Cai, Xiangjun; Mattano, Leonard A; Boyd, Kelli L; Funk, Amy J; Relling, Mary V

    2016-01-01

    Osteonecrosis is a common dose-limiting toxicity of glucocorticoids. Data from clinical trials suggest that other medications can increase the risk of glucocorticoid-induced osteonecrosis. Here we utilized a mouse model to study the effect of asparaginase treatment on dexamethasone-induced osteonecrosis. Mice receiving asparaginase along with dexamethasone had a higher rate of osteonecrosis than those receiving only dexamethasone after 6 weeks of treatment (44% vs. 10%, P = 0.006). Similarly, epiphyseal arteriopathy, which we have shown to be an initiating event for osteonecrosis, was observed in 58% of mice receiving asparaginase and dexamethasone compared to 17% of mice receiving dexamethasone only (P = 0.007). As in the clinic, greater exposure to asparaginase was associated with greater plasma exposure to dexamethasone (P = 0.0001). This model also recapitulated other clinical risk factors for osteonecrosis, including age at start of treatment, and association with the systemic exposure to dexamethasone (P = 0.027) and asparaginase (P = 0.036). We conclude that asparaginase can potentiate the osteonecrotic effect of glucocorticoids.

  6. Endoscopic pH Monitoring for Patients with Suspected or Refractory Gastroesophageal Reflux Disease

    Directory of Open Access Journals (Sweden)

    Brian G Turner

    2007-01-01

    Full Text Available BACKGROUND: Wireless pH studies can offer prolonged pH monitoring, which may potentially facilitate the diagnosis and management of patients with gastroesophageal reflux disease (GERD. The aim of the present study was to evaluate the detection rate of abnormal esophageal acid exposure using prolonged pH monitoring in patients with suspected or refractory GERD symptoms.

  7. Temporal artery biopsy is not required in all cases of suspected giant cell arteritis.

    LENUS (Irish Health Repository)

    Quinn, Edel Marie

    2012-07-01

    Temporal artery biopsy (TAB) is performed during the diagnostic workup for giant cell arteritis (GCA), a vasculitis with the potential to cause irreversible blindness or stroke. However, treatment is often started on clinical grounds, and TAB result frequently does not influence patient management. The aim of this study was to assess the need for TAB in cases of suspected GCA.

  8. Pulmonary mycoses among the clinically suspected cases of pulmonary tuberculosis

    OpenAIRE

    Tshering Ongmu Bhutia; Luna Adhikari

    2015-01-01

    Background: This study was carried with the main objectives: (1) to find out the occurrence of pulmonary mycoses in clinically suspected pulmonary tuberculosis cases at central referral hospital, Tadong, Sikkim. (2) To find out the various fungi causing pulmonary mycoses in clinically suspected pulmonary tuberculosis cases. Methods: 200 clinically suspected pulmonary tuberculosis cases who visited the department of microbiology for the diagnostic microscopic examination of sputum sample f...

  9. Examination of a Theoretical Model of Streaming Potential Coupling Coefficient

    NARCIS (Netherlands)

    Luong, D.T.; Sprik, R.

    2014-01-01

    Seismoelectric effects and streaming potentials play an important role in geophysical applications. The key parameter for those phenomena is the streaming potential coupling coefficient, which is, for example, dependent on the zeta potential of the interface of the porous rocks. Comparison of an

  10. Optimisation of Ionic Models to Fit Tissue Action Potentials: Application to 3D Atrial Modelling

    Directory of Open Access Journals (Sweden)

    Amr Al Abed

    2013-01-01

    Full Text Available A 3D model of atrial electrical activity has been developed with spatially heterogeneous electrophysiological properties. The atrial geometry, reconstructed from the male Visible Human dataset, included gross anatomical features such as the central and peripheral sinoatrial node (SAN, intra-atrial connections, pulmonary veins, inferior and superior vena cava, and the coronary sinus. Membrane potentials of myocytes from spontaneously active or electrically paced in vitro rabbit cardiac tissue preparations were recorded using intracellular glass microelectrodes. Action potentials of central and peripheral SAN, right and left atrial, and pulmonary vein myocytes were each fitted using a generic ionic model having three phenomenological ionic current components: one time-dependent inward, one time-dependent outward, and one leakage current. To bridge the gap between the single-cell ionic models and the gross electrical behaviour of the 3D whole-atrial model, a simplified 2D tissue disc with heterogeneous regions was optimised to arrive at parameters for each cell type under electrotonic load. Parameters were then incorporated into the 3D atrial model, which as a result exhibited a spontaneously active SAN able to rhythmically excite the atria. The tissue-based optimisation of ionic models and the modelling process outlined are generic and applicable to image-based computer reconstruction and simulation of excitable tissue.

  11. Neuroprotective potential of ceftriaxone in in vitro models of stroke.

    Science.gov (United States)

    Lipski, J; Wan, C K; Bai, J Z; Pi, R; Li, D; Donnelly, D

    2007-05-11

    Astrocytic glutamate transporters are considered an important target for neuroprotective therapies as the function of these transporters is abnormal in stroke and other neurological disorders associated with excitotoxicity. Recently, Rothstein et al., [Rothstein JD, Patel S, Regan MR, Haenggeli C, Huang YH, Bergles DE, Jin L, Dykes Hoberg M, Vidensky S, Chung DS, Toan SV, Bruijn LI, Su ZZ, Gupta P, Fisher PB (2005) Beta-lactam antibiotics offer neuroprotection by increasing glutamate transporter expression. Nature 433:73-77] reported that beta-lactam antibiotics (including ceftriaxone, which easily crosses the blood-brain barrier) increase glutamate transporter 1 (GLT-1) expression and reduce cell death resulting from oxygen-glucose deprivation (OGD) in dissociated embryonic cortical cultures. To determine whether a similar neuroprotective mechanism operates in more mature neurons, which show a different pattern of response to ischemia than primary cultures, we exposed acute hippocampal slices obtained from rats treated with ceftriaxone for 5 days (200 mg/kg; i.p.) to OGD. Whole-cell patch clamp recording of glutamate-induced N-methyl-d-aspartate (NMDA) currents from CA1 pyramidal neurons showed a larger potentiation of these currents after application of 15 microM dl-threo-beta-benzyloxyaspartic acid (TBOA; a potent blocker of glutamate transporters) in ceftriaxone-injected animals than in untreated animals, indicating increased glutamate transporter activity. Western blot analysis did not reveal GLT-1 upregulation in the hippocampus. Delay to OGD-induced hypoxic spreading depression (HSD) recorded in slices obtained from ceftriaxone-treated rats was longer (6.3+/-0.2 vs. 5.2+/-0.2 min; Paction of the antibiotic in this model. The effect of ceftriaxone was also tested in organotypic hippocampal slices obtained from P7-9 rats (>14 days in vitro). OGD or glutamate (3.5-5.0 mM) damaged CA1 pyramidal neurons as assessed by propidium iodide (PI) fluorescence. Similar

  12. Seasonal variation among tuberculosis suspects in four countries

    DEFF Research Database (Denmark)

    Mabaera, Biggie; Naranbat, Nymadawa; Katamba, Achilles

    2009-01-01

    The objective of the study was to analyze monthly trends across a calendar year in tuberculosis suspects and sputum smear-positive cases based on nationally representative samples of tuberculosis laboratory registers from Moldova, Mongolia, Uganda and Zimbabwe. Out of the 47 140 suspects registered...... in the tuberculosis laboratory registers, 13.4% (6312) were cases. The proportion varied from country to country, Moldova having the lowest (9%) and Uganda the highest (21%). From the monthly proportion of suspects and cases among total suspects and cases, seasonal variations were most marked in Mongolia which, among...... attendance to diagnostic laboratory services, evidenced by the contrasting findings of Mongolia (extreme continental northern climate) compared to Uganda (equatorial climate). A combination of external and possibly endogenous factors seems to determine whether tuberculosis suspects and cases present...

  13. Modeling Potentially Time-Varying Effects of Promotions on Sales

    NARCIS (Netherlands)

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

    2001-01-01

    textabstractA commonly applied modeling tool for the analysis of promotional effects on weekly sales data is a linear regression model. Usually, such a model includes 0/1 dummy variables for promotions, where weeks with a promotion get a value of 1. When these variables are included in a model with

  14. Control of Suspect/Counterfeit and Defective Items

    Energy Technology Data Exchange (ETDEWEB)

    Sheriff, Marnelle L.

    2013-09-03

    This procedure implements portions of the requirements of MSC-MP-599, Quality Assurance Program Description. It establishes the Mission Support Alliance (MSA) practices for minimizing the introduction of and identifying, documenting, dispositioning, reporting, controlling, and disposing of suspect/counterfeit and defective items (S/CIs). employees whose work scope relates to Safety Systems (i.e., Safety Class [SC] or Safety Significant [SS] items), non-safety systems and other applications (i.e., General Service [GS]) where engineering has determined that their use could result in a potential safety hazard. MSA implements an effective Quality Assurance (QA) Program providing a comprehensive network of controls and verification providing defense-in-depth by preventing the introduction of S/CIs through the design, procurement, construction, operation, maintenance, and modification of processes. This procedure focuses on those safety systems, and other systems, including critical load paths of lifting equipment, where the introduction of S/CIs would have the greatest potential for creating unsafe conditions.

  15. [Potentials of 3D-modeling in reconstructive orbital surgery].

    Science.gov (United States)

    Butsan, S B; Khokhlachev, S B; Ĭigitaliev, Sh N; Zaiakin, Ia A

    2012-01-01

    A technique of bone reconstructive surgery of orbitofrontonasomalar region using 3D-modeling based on multispiral computer tomography data is presented. The efficacy of intraoperative templates created using 3D-modeling was showed for harvesting and modeling of bone calvarial autografts. The steps of reconstructive procedure are explained in details for repair of medial and inferior orbital fractures.

  16. Spherical Calogero model with oscillator/Coulomb potential: classical case

    CERN Document Server

    Correa, Francisco; Lechtenfeld, Olaf; Nersessian, Armen

    2016-01-01

    We construct the Hamiltonians and symmetry generators of Calogero-oscillator and Calogero-Coulomb models on the N-dimensional sphere within the matrix-model reduction approach. Our method also produces the integrable Calogero-Coulomb-Stark model on the sphere and proves the integrability of the spin extensions of all these systems.

  17. Helium-3 Microscopic Optical Model Potential Based on Skyrme Interaction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The helium-3 microscopic optical potential is obtained by Green function method through nuclear matter approximation and local density approximation based on the effective Skyrme interaction. The reaction cross

  18. Soliton-potential interaction in the Nonlinear Klein-Gordon Model

    CERN Document Server

    Saadatmand, Danial

    2011-01-01

    Interaction of solitons with external potentials in nonlinear Klein-Gordon field theory is investigated using an improved model. Presented model is constructed with a better approximation for adding the potential to the lagrangian through the metric of background space-time. The results of the model are compared with the another model and the differences are discussed.

  19. LFPy and hybrid scheme for local field potentials. CNS2014 tutorial T4: Modeling and analysis of extracellular potentials

    OpenAIRE

    Hagen, Espen

    2014-01-01

    T4: Modeling and analysis of extracellular potentialsGaute Einevoll, Norwegian University of Life Sciences, Ås, NorwaySzymon Łęski (Nencki Institute of Experimental Biology, Warsaw)Espen Hagen (Norwegian University of Life Sciences, Ås)While extracellular electrical recordings have been the main workhorse in electrophysiology, the interpretation of such recordings is not trivial [1,2,3]. The recorded extracellular potentials in general stem from a complicated sum of contributions from all tr...

  20. [Potential of the zebrafish model to study congenital muscular dystrophies].

    Science.gov (United States)

    Ryckebüsch, Lucile

    2015-10-01

    In order to better understand the complexity of congenital muscular dystrophies (CMD) and develop new strategies to cure them, it is important to establish new disease models. Due to its numerous helpful attributes, the zebrafish has recently become a very powerful animal model for the study of CMD. For some CMD, this vertebrate model is phenotypically closer to human pathology than the murine model. Over the last few years, researchers have developed innovative techniques to screen rapidly and on a large scale for muscle defects in zebrafish. Furthermore, new genome editing techniques in zebrafish make possible the identification of new disease models. In this review, the major attributes of zebrafish for CMD studies are discussed and the principal models of CMD in zebrafish are highlighted.

  1. Model simulation of storm surge potential for Andaman islands

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, V.S.; RameshBabu, V.; Babu, M.T.; Dhinakaran, G.; Rajamanickam, G.V.

    ) for storm surge forecasting at the eastern coast of India. Flather (1994) has applied another analytical model of Holland (1980) for wind and pressure fields in the case of surge simulation, forced by April 1991 Bangladesh storm. The basic atmospheric... parameters remain the same in all the parameterization schemes of storm wind field. Storm Surge Model Storm surge operational models are in use for a long time for forecasting and warning of storm surge disasters bordering the coasts in the parts of northern...

  2. Perturbation theory calculations of model pair potential systems

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Jianwu [Iowa State Univ., Ames, IA (United States)

    2016-01-01

    Helmholtz free energy is one of the most important thermodynamic properties for condensed matter systems. It is closely related to other thermodynamic properties such as chemical potential and compressibility. It is also the starting point for studies of interfacial properties and phase coexistence if free energies of different phases can be obtained. In this thesis, we will use an approach based on the Weeks-Chandler-Anderson (WCA) perturbation theory to calculate the free energy of both solid and liquid phases of Lennard-Jones pair potential systems and the free energy of liquid states of Yukawa pair potentials. Our results indicate that the perturbation theory provides an accurate approach to the free energy calculations of liquid and solid phases based upon comparisons with results from molecular dynamics (MD) and Monte Carlo (MC) simulations.

  3. A comparison of interatomic potentials for modeling tungsten nanocluster structures

    Science.gov (United States)

    Hao, Jiannan; Shu, Xiaolin; Jin, Shuo; Zhang, Xuesong; Zhang, Ying; Lu, Guang-Hong

    2017-02-01

    Molecular dynamic simulation is utilized to study the nanocluster and the fuzz structure on the PFM surface of tungsten. The polyhedral and linear cluster structures based on the icosahedron, cuboctahedron and rhombic dodecahedron are built up. Three interatomic potentials are used in calculating the relationship between the cluster energy and the number of atoms. The results are compared with first-principles calculation to show each potential's best application scale. Furthermore, the transition between the icosahedral and the cuboctahedral clusters is observed in molecular dynamic simulation at different temperatures, which follows a critical curve for different numbers of atoms. The linear structures are proved to be stable at experimental temperatures by thermodynamics. The work presents a selection of interatomic potentials in simulating tungsten cluster systems and helps researchers understand the growth and evolution laws of clusters and the fuzz-like structure formation process in fusion devices.

  4. Kinetic Potential Model of the Cloud-to-Drizzle Transition

    Science.gov (United States)

    McGraw, Robert; Liu, Yangang; Luke, Edward; Senum, Gunnar

    2013-03-01

    It has been nearly a decade since the kinetic potential theory of drizzle formation in warm clouds was introduced [McGraw and Liu, Phys. Rev. Letts. 90, 018501 (2003)], and much progress in understanding the cloud-drizzle transition, especially regarding the role of turbulence, has been achieved within its framework. This poster will begin with an introduction to the kinetic potential idea, working up to the method it provides for predicting drizzle threshold conditions and rates, and concludes with an analysis this year of DOE/ARM cloud parcel vertical velocity measurements - discussing their implications for assessing turbulence fluctuations in water vapor saturation ratio and cloud droplet size.

  5. Maxent modelling for predicting the potential distribution of Thai Palms

    DEFF Research Database (Denmark)

    Tovaranonte, Jantrararuk; Barfod, Anders S.; Overgaard, Anne Blach

    2011-01-01

    Increasingly species distribution models are being used to address questions related to ecology, biogeography and species conservation on global and regional scales. We used the maximum entropy approach implemented in the MAXENT programme to build a habitat suitability model for Thai palms based ...... in Thailand based on overlays of all species with more than 5 records (n = 103)....

  6. A spatial model of potential jaguar habitat in Arizona

    Science.gov (United States)

    Hatten, J.R.; Averill-Murray, A.; van Pelt, W.E.

    2005-01-01

    The jaguar (Panthera onca) is an endangered species that occasionally visits the southwestern United States from Mexico. The number of jaguar sightings per decade has declined over the last 100 years in Arizona, USA, raising conservation concerns for the species at a local and national level. In 1997, state, federal, and local governments with land-management responsibilities agreed to characterize and identify potential jaguar habitat in Arizona and New Mexico. Specifically, the objectives of our analysis were 2-fold: (1) characterize potential jaguar habitat in Arizona from historic sighting records and (2) create a statewide habitat suitability map. We used a Geographic Information System (GIS) to characterize potential jaguar habitat by overlaying historic jaguar sightings (25) on landscape and habitat features believed important (e.g., vegetation biomes and series, elevation, terrain ruggedness, proximity to perennial or intermittent water sources, human density). The amount of Arizona (%) identified as potential jaguar habitat ranged from 21% to 30% depending on the input variables. Most jaguar sightings were in scrub grasslands between 1,220 and 1,829-m elevation in southeastern Arizona, in intermediately to extremely rugged terrain, and within 10 km of a water source. Conservation efforts should focus on protecting the most suitable jaguar habitat in southeastern Arizona (i.e., Santa Cruz, Pima, Cochise, Pinal, Graham counties), travel corridors within and outside Arizona, and jaguar habitat in the Sierra Madres of Sonora, Mexico.

  7. Modelling intelligence-led policing to identify its potential

    NARCIS (Netherlands)

    Hengst-Bruggeling, M. den; Graaf, H.A.L.M. de; Scheepstal, P.G.M. van

    2014-01-01

    lntelligence-led policing is a concept of policing that has been applied throughout the world. Despite some encouraging reports, the effect of intelligence-led policing is largely unknown. This paper presents a method with which it is possible to identify intelligence-led policing's potential to

  8. Modelling intelligence-led policing to identify its potential

    NARCIS (Netherlands)

    Hengst-Bruggeling, M. den; Graaf, H.A.L.M. de; Scheepstal, P.G.M. van

    2014-01-01

    lntelligence-led policing is a concept of policing that has been applied throughout the world. Despite some encouraging reports, the effect of intelligence-led policing is largely unknown. This paper presents a method with which it is possible to identify intelligence-led policing's potential to inc

  9. Modeling potential river management conflicts between frogs and salmonids

    Science.gov (United States)

    Steven F. Railsback; Bret C. Harvey; Sarah J. Kupferberg; Margaret M. Lang; Scott McBain; Hart H. Welsh

    2016-01-01

    Management of regulated rivers for yellow-legged frogs (Rana boylii) and salmonids exemplifies potential conflicts among species adapted to different parts of the natural flow and temperature regimes. Yellow-legged frogs oviposit in rivers in spring and depend on declining flows and warming temperatures for egg and tadpole survival and growth,...

  10. Modelling of water potential and water uptake rate of tomato plants in the greenhouse: preliminary results.

    NARCIS (Netherlands)

    Bruggink, G.T.; Schouwink, H.E.; Gieling, Th.H.

    1988-01-01

    A dynamic model is presented which predicts water potential and water uptake rate of greenhouse tomato plants using transpiration rate as input. The model assumes that water uptake is the resultant of water potential and hydraulic resistance, and that water potential is linearly related to water con

  11. Model independent optical potential for protons at 155 MeV

    Science.gov (United States)

    Brissaud, I.

    1981-06-01

    Using the model independent procedure, 155 MeV proton optical potentials are deduced from the elastic scattering data. The nuclear interior of these potentials are less attractative than predicted by a phenomenological potentials. A comparison is done with a self consistent meson model.

  12. Spatial and frequency domain ring source models for the single muscle fiber action potential

    DEFF Research Database (Denmark)

    Henneberg, Kaj-åge; R., Plonsey

    1994-01-01

    In the paper, single-fibre models for the extracellular action potential are developed that will allow the potential to the evaluated at an arbitrary field point in the extracellular space. Fourier-domain models are restricted in that they evaluate potentials at equidistant points along a line...

  13. Snowmelt runoff modeling: Limitations and potential for mitigating water disputes

    Science.gov (United States)

    Kult, Jonathan; Choi, Woonsup; Keuser, Anke

    2012-04-01

    SummaryConceptual snowmelt runoff models have proven useful for estimating discharge from remote mountain basins including those spanning the various ranges of the Himalaya. Such models can provide water resource managers with fairly accurate predictions of water availability for operational purposes (e.g. irrigation and hydropower). However, these models have limited ability to address characteristic components of water disputes such as diversions, storage and withholding. Contemporary disputes between India and Pakistan surrounding the snowmelt-derived water resources of the Upper Indus Basin highlight the need for improved water balance accounting methods. We present a research agenda focused on providing refined hydrological contributions to water dispute mitigation efforts.

  14. Bronchoalveolar Lavage Proteomics in Patients with Suspected Lung Cancer

    Science.gov (United States)

    Carvalho, Ana Sofia; Cuco, Célia Marina; Lavareda, Carla; Miguel, Francisco; Ventura, Mafalda; Almeida, Sónia; Pinto, Paula; de Abreu, Tiago Tavares; Rodrigues, Luís Vaz; Seixas, Susana; Bárbara, Cristina; Azkargorta, Mikel; Elortza, Felix; Semedo, Júlio; Field, John K.; Mota, Leonor; Matthiesen, Rune

    2017-01-01

    Lung cancer configures as one of the deadliest types of cancer. The future implementation of early screening methods such as exhaled breath condensate analysis and low dose computed tomography (CT) as an alternative to current chest imaging based screening will lead to an increased burden on bronchoscopy units. New approaches for improvement of diagnosis in bronchoscopy units, regarding patient management, are likely to have clinical impact in the future. Diagnostic approaches to address mortality of lung cancer include improved early detection and stratification of the cancers according to its prognosis and further response to drug treatment. In this study, we performed a detailed mass spectrometry based proteome analysis of acellular bronchoalveolar lavage (BAL) fluid samples on an observational prospective cohort consisting of 90 suspected lung cancer cases which were followed during two years. The thirteen new lung cancer cases diagnosed during the follow up time period clustered, based on liquid chromatography-mass spectrometry (LC-MS) data, with lung cancer cases at the time of BAL collection. Hundred and thirty-tree potential biomarkers were identified showing significantly differential expression when comparing lung cancer versus non-lung cancer. The regulated biomarkers showed a large overlap with biomarkers detected in tissue samples. PMID:28169345

  15. Key Challenges and Potential Urban Modelling Opportunities in ...

    African Journals Online (AJOL)

    Chris Wray

    monitoring and guiding urban spatial planning and development. ... and social system functions, urban modelling has evolved from simple ... careful long-term planning aligned with the national vision and other strategic perspectives' (GPC,.

  16. Stopping and Questioning Suspected Shoplifters Without Creating Civil Liability

    Science.gov (United States)

    Reed, Jack R., Jr.

    1977-01-01

    Legal problems concerned with shoplifting suspects are addressed, including common law, criminal penalties, and the merchant's liability. Tangential questions and answers are presented along with discussion of pertinent court cases. (LBH)

  17. Suspect confession of child sexual abuse to investigators.

    Science.gov (United States)

    Lippert, Tonya; Cross, Theodore P; Jones, Lisa; Walsh, Wendy

    2010-05-01

    Increasing the number of suspects who give true confessions of sexual abuse serves justice and reduces the burden of the criminal justice process on child victims. With data from four communities, this study examined confession rates and predictors of confession of child sexual abuse over the course of criminal investigations (final N = 282). Overall, 30% of suspects confessed partially or fully to the crime. This rate was consistent across the communities and is very similar to the rates of suspect confession of child sexual abuse found by previous research, although lower than that from a study focused on a community with a vigorous practice of polygraph testing. In a multivariate analysis, confession was more likely when suspects were younger and when more evidence of abuse was available, particularly child disclosure and corroborative evidence. These results suggest the difficulty of obtaining confession but also the value of methods that facilitate child disclosure and seek corroborative evidence, for increasing the odds of confession.

  18. The mass spectrum of double heavy baryons in new potential quark models

    Directory of Open Access Journals (Sweden)

    Kovalenko Vladimir

    2017-01-01

    Full Text Available A new approach to study the mass spectrum of double heavy baryons (QQ′q containing strange and charmed quarks is proposed. It is based on the separation of variables in the Schrodinger equation in the prolate spheroidal coordinates. Two nonrelativistic potential models are considered. In the first model, the interaction potential of the quarks is the sum of the Coulomb and non-spherically symmetrical linear confinement potential. In the second model it is assumed that the quark confinement provided by a spherically symmetric harmonic oscillator potential. In both models the mass spectrum is calculated, and a comparison with previous results from other models is performed.

  19. A simple model for the generation of the vestibular evoked myogenic potential (VEMP)

    NARCIS (Netherlands)

    Wit, HP; Kingma, CM

    2006-01-01

    Objective: To describe the mechanism by which the vestibular evoked myogenic potential is generated. Methods: Vestibular evoked myogenic potential generation is modeled by adding a large number of muscle motor unit action potentials. These action potentials occur randomly in time along a 100 ms long

  20. Using Internet Artifacts to Profile a Child Pornography Suspect

    OpenAIRE

    Marcus K. Rogers; Seigfried-Spellar, Kathryn C

    2014-01-01

    Digital evidence plays a crucial role in child pornography investigations. However, in the following case study, the authors argue that the behavioral analysis or “profiling” of digital evidence can also play a vital role in child pornography investigations. The following case study assessed the Internet Browsing History (Internet Explorer Bookmarks, Mozilla Bookmarks, and Mozilla History) from a suspected child pornography user’s computer. The suspect in this case claimed to be conducting an...

  1. Modelling organic crystal structures using distributed multipole and polarizability-based model intermolecular potentials.

    Science.gov (United States)

    Price, Sarah L; Leslie, Maurice; Welch, Gareth W A; Habgood, Matthew; Price, Louise S; Karamertzanis, Panagiotis G; Day, Graeme M

    2010-08-14

    Crystal structure prediction for organic molecules requires both the fast assessment of thousands to millions of crystal structures and the greatest possible accuracy in their relative energies. We describe a crystal lattice simulation program, DMACRYS, emphasizing the features that make it suitable for use in crystal structure prediction for pharmaceutical molecules using accurate anisotropic atom-atom model intermolecular potentials based on the theory of intermolecular forces. DMACRYS can optimize the lattice energy of a crystal, calculate the second derivative properties, and reduce the symmetry of the spacegroup to move away from a transition state. The calculated terahertz frequency k = 0 rigid-body lattice modes and elastic tensor can be used to estimate free energies. The program uses a distributed multipole electrostatic model (Q, t = 00,...,44s) for the electrostatic fields, and can use anisotropic atom-atom repulsion models, damped isotropic dispersion up to R(-10), as well as a range of empirically fitted isotropic exp-6 atom-atom models with different definitions of atomic types. A new feature is that an accurate model for the induction energy contribution to the lattice energy has been implemented that uses atomic anisotropic dipole polarizability models (alpha, t = (10,10)...(11c,11s)) to evaluate the changes in the molecular charge density induced by the electrostatic field within the crystal. It is demonstrated, using the four polymorphs of the pharmaceutical carbamazepine C(15)H(12)N(2)O, that whilst reproducing crystal structures is relatively easy, calculating the polymorphic energy differences to the accuracy of a few kJ mol(-1) required for applications is very demanding of assumptions made in the modelling. Thus DMACRYS enables the comparison of both known and hypothetical crystal structures as an aid to the development of pharmaceuticals and other speciality organic materials, and provides a tool to develop the modelling of the

  2. Observing the inflation potential. [in models of cosmological inflation

    Science.gov (United States)

    Copeland, Edmund J.; Kolb, Edward W.; Liddle, Andrew R.; Lidsey, James E.

    1993-01-01

    We show how observations of the density perturbation (scalar) spectrum and the gravitational wave (tensor) spectrum allow a reconstruction of the potential responsible for cosmological inflation. A complete functional reconstruction or a perturbative approximation about a single scale are possible; the suitability of each approach depends on the data available. Consistency equations between the scalar and tensor spectra are derived, which provide a powerful signal of inflation.

  3. Predictors of Bacteraemia in Patients with Suspected Community-Acquired Pneumonia.

    Directory of Open Access Journals (Sweden)

    Cornelis H van Werkhoven

    Full Text Available The diagnostic yield of blood cultures is limited in patients with community-acquired pneumonia (CAP. Yet, positive blood culture results provide important information for antibiotic treatment and for monitoring epidemiologic trends. We investigated the potential of clinical predictors to improve the cost-benefit ratio of obtaining blood cultures.Data from two prospective cohort studies of adults with suspected CAP, admitted to non-ICU wards, were combined. Two models were created, one using readily available parameters and one additionally including laboratory parameters.3,786 patients were included (2,626 (69% with X-ray confirmed CAP. Blood cultures were obtained from 2,977 (79% patients (and from 2,107 (80% with X-ray confirmed CAP. 266 (8.9% of the patients with a blood culture had bacteraemia. Clinical predictors of bacteraemia were absence of pre-admission antibiotic treatment, pleuritic pain, gastro-intestinal symptoms, tachycardia, tachypnea, hypotension and absence of hypoxia. After including laboratory results in the model, younger age, C-reactive protein, leukocytosis or leukopenia, low thrombocyte count, low sodium level, elevated urea and elevated arterial pH were added, while gastro-intestinal symptoms and hypotension were no longer significant. The area under the receiver operating characteristics curve was 0.66 (95% confidence interval 0.63-0.70 for the first model and 0.76 (95% confidence interval 0.73-0.79 for the second model.In conclusion, in patients hospitalized with CAP, bacteraemia was moderately predictable using clinical parameters only. We recommend against the use of a risk prediction model for the decision to obtain blood cultures.

  4. Quantum origins of the Iczkowski-Margrave model of chemical potential

    Energy Technology Data Exchange (ETDEWEB)

    Valone, Steven M [Los Alamos National Laboratory

    2010-01-01

    Charge flow in materials is controlled at the atomistic level through some model of the chemical potential, such as the Iczkowski-Margrave (IM) model. This model is built largely on heuristic arguments. Here a model Hamiltonian is constructed at the atomistic level commensurate with the IM model. Essential properties of the model Hamiltonian are presented, including a possible revision of the charge dependence in the IM model. Transitional properties of the model are shown to be central to regulating charge flow.

  5. Potential and limitations of 1D modelling of urban flooding

    Science.gov (United States)

    Mark, Ole; Weesakul, Sutat; Apirumanekul, Chusit; Aroonnet, Surajate Boonya; Djordjević, Slobodan

    2004-12-01

    Urban flooding is an inevitable problem for many cities around the world. In the present paper, modelling approaches and principles for analyses of urban flooding are outlined. The paper shows how urban flooding can be simulated by one-dimensional hydrodynamic modelling incorporating the interaction between (i) the buried pipe system, (ii) the streets (with open channel flow) and (iii) the areas flooded with stagnant water. The modelling approach is generic in the sense that it handles both urban flooding with and without flood water entry into houses. In order to visualize flood extent and impact, the modelling results are presented in the form of flood inundation maps produced in GIS. In this paper, only flooding from local rainfall is considered together with the impact in terms of flood extent, flood depth and flood duration. Finally, the paper discusses the data requirement for verification of urban flood models together with an outline of a simple cost function for estimation of the cost of the flood damages.

  6. Interviewing strategically to elicit admissions from guilty suspects.

    Science.gov (United States)

    Tekin, Serra; Granhag, Pär Anders; Strömwall, Leif; Giolla, Erik Mac; Vrij, Aldert; Hartwig, Maria

    2015-06-01

    In this article we introduce a novel interviewing tactic to elicit admissions from guilty suspects. By influencing the suspects' perception of the amount of evidence the interviewer holds against them, we aimed to shift the suspects' counterinterrogation strategies from less to more forthcoming. The proposed tactic (SUE-Confrontation) is a development of the Strategic Use of Evidence (SUE) framework and aims to affect the suspects' perception by confronting them with statement-evidence inconsistencies. Participants (N = 90) were asked to perform several mock criminal tasks before being interviewed using 1 of 3 interview techniques: (a) SUE-Confrontation, (b) Early Disclosure of Evidence, or (c) No Disclosure of Evidence. As predicted, the SUE-Confrontation interview generated more statement-evidence inconsistencies from suspects than the Early Disclosure interview. Importantly, suspects in the SUE-Confrontation condition (vs. Early and No disclosure conditions) admitted more self-incriminating information and also perceived the interviewer to have had more information about the critical phase of the crime (the phase where the interviewer lacked evidence). The findings show the adaptability of the SUE-technique and how it may be used as a tool for eliciting admissions.

  7. Modelling thermal stratification in the North Sea: Application of a 2-D potential energy model

    DEFF Research Database (Denmark)

    Nielsen, Morten Holtegaard; St. John, Michael

    2001-01-01

    energy as water masses of different densities are mixed in the field of gravity. A constant ratio between the gain in potential energy and the production of TKE is assumed, known as the flux Richardson number. The model is comprised of 0·5m vertical layers with a temporal time step of 1 day. The model...... is forced with wind, dew point temperature from Ekofisk oilfield in the central North Sea, and tidal current and atmospheric radiation. The model is used to simulate the seasonal cycle of stratification in the central North Sea in the years 1988, 1989 and 1990 and is compared to density profiles...... an R2=0·97 between observed and predicted upper layer temperatures. However, the model is less successful in the prediction of temperatures of the intermediate and deep layers (R2=0·46 and 0·14) due to small deviations in thermocline depth and variations in tidal amplitude. The model was then applied...

  8. Brownian motion and parabolic Anderson model in a renormalized Poisson potential

    OpenAIRE

    Chen, Xia; Kulik, Alexey M.

    2012-01-01

    A method known as renormalization is proposed for constructing some more physically realistic random potentials in a Poisson cloud. The Brownian motion in the renormalized random potential and related parabolic Anderson models are modeled. With the renormalization, for example, the models consistent to Newton’s law of universal attraction can be rigorously constructed.

  9. Challenges and potential solutions for European coastal ocean modelling

    Science.gov (United States)

    She, Jun; Stanev, Emil

    2017-04-01

    Coastal operational oceanography is a science and technological platform to integrate and transform the outcomes in marine monitoring, new knowledge generation and innovative technologies into operational information products and services in the coastal ocean. It has been identified as one of the four research priorities by EuroGOOS (She et al. 2016). Coastal modelling plays a central role in such an integration and transformation. A next generation coastal ocean forecasting system should have following features: i) being able to fully exploit benefits from future observations, ii) generate meaningful products in finer scales e.g., sub-mesoscale and in estuary-coast-sea continuum, iii) efficient parallel computing and model grid structure, iv) provide high quality forecasts as forcing to NWP and coastal climate models, v) resolving correctly inter-basin and inter-sub-basin water exchange, vi) resolving synoptic variability and predictability in marine ecosystems, e.g., for algae bloom, vi) being able to address critical and relevant issues in coastal applications, e.g., marine spatial planning, maritime safety, marine pollution protection, disaster prevention, offshore wind energy, climate change adaptation and mitigation, ICZM (integrated coastal zone management), the WFD (Water Framework Directive), and the MSFD (Marine Strategy Framework Directive), especially on habitat, eutrophication, and hydrographic condition descriptors. This presentation will address above challenges, identify limits of current models and propose correspondent research needed. The proposed roadmap will address an integrated monitoring-modelling approach and developing Unified European Coastal Ocean Models. In the coming years, a few new developments in European Sea observations can expected, e.g., more near real time delivering on profile observations made by research vessels, more shallow water Argo floats and bio-Argo floats deployed, much more high resolution sea level data from SWOT

  10. Influence of Random Potentials on the Current of the Molecular Motor Model

    Institute of Scientific and Technical Information of China (English)

    贾亚; 李家荣

    2001-01-01

    The current of the molecular motor model disturbed by random potentials, which involve the dichotomous and Ornstein-Uhlenbeck potentials, is studied using a finite-space correlation function. It is found that: (i) the amplitude and the correlation length of random potentials play opposing roles in the transport of the molecular motor model; (ii) a random potential with small amplitude and large correlation length is very useful in the molecular motor system.

  11. Relativistic Modeling of Quark Stars with Tolman IV Type Potential

    CERN Document Server

    Malaver, Manuel

    2015-01-01

    In this paper, we studied the behavior of relativistic objects with anisotropic matter distribution considering Tolman IV form for the gravitational potential Z. The equation of state presents a quadratic relation between the energy density and the radial pressure. New exact solutions of the Einstein-Maxwell system are generated. A physical analysis of electromagnetic field indicates that is regular in the origin and well behaved. We show as the presence of an electrical field modifies the energy density, the radial pressure and the mass of the stellar object and generates a singular charge density.

  12. Modeling action potential generation and propagation in NRK fibroblasts

    NARCIS (Netherlands)

    Torres, J.J.; Cornelisse, L.N.; Harks, E.G.; Meerwijk, W.P. van; Theuvenet, A.P.R.; Ypey, D.L.

    2004-01-01

    Normal rat kidney (NRK) fibroblasts change their excitability properties through the various stages of cell proliferation. The present mathematical model has been developed to explain excitability of quiescent (serum deprived) NRK cells. It includes as cell membrane components, on the basis of patch

  13. Suspect/Counterfeit Items Information Guide for Subcontractors/Suppliers

    Energy Technology Data Exchange (ETDEWEB)

    Tessmar, Nancy D. [Los Alamos National Laboratory; Salazar, Michael J. [Los Alamos National Laboratory

    2012-09-18

    Counterfeiting of industrial and commercial grade items is an international problem that places worker safety, program objectives, expensive equipment, and security at risk. In order to prevent the introduction of Suspect/Counterfeit Items (S/CI), this information sheet is being made available as a guide to assist in the implementation of S/CI awareness and controls, in conjunction with subcontractor's/supplier's quality assurance programs. When it comes to counterfeit goods, including industrial materials, items, and equipment, no market is immune. Some manufactures have been known to misrepresent their products and intentionally use inferior materials and processes to manufacture substandard items, whose properties can significantly cart from established standards and specifications. These substandard items termed by the Department of Energy (DOE) as S/CI, pose immediate and potential threats to the safety of DOE and contractor workers, the public, and the environment. Failure of certain systems and processes caused by an S/CI could also have national security implications at Los Alamos National Laboratory (LANL). Nuclear Safety Rules (federal Laws), DOE Orders, and other regulations set forth requirements for DOE contractors to implement effective controls to assure that items and services meet specified requirements. This includes techniques to implement and thereby minimizing the potential threat of entry of S/CI to LANL. As a qualified supplier of goods or services to the LANL, your company will be required to establish and maintain effective controls to prevent the introduction of S/CI to LANL. This will require that your company warrant that all items (including their subassemblies, components, and parts) sold to LANL are genuine (i.e. not counterfeit), new, and unused, and conform to the requirements of the LANL purchase orders/contracts unless otherwise approved in writing to the Los Alamos National Security (LANS) contract administrator

  14. Suspected dog bite associated HIV horizontal transmission in Swaziland

    Directory of Open Access Journals (Sweden)

    Ganizani Mlawanda

    2013-01-01

    Full Text Available Background: Dog bites may lead to transmission of bacteria and viruses over and above tetanus and rabies. Theoretically human immunodeficiency virus (HIV, Hepatitis B and Hepatitis C may be transmitted after dog bites where transfer of blood from one victim to another occur in clinical practice HIV, Hepatitis B and Hepatitis C are not considered when making treatment decisions, nor adequate patient history taken to consider all potential risks after dog bites in succession.Objective: To present case of suspected HIV transmission after dog bites in close succession involving two HIV sero-discordant victims.Management and outcome: HIV rapid test and/or HIV Ribonucleic acid (RNA polymerasechain reaction (PCR results for the victim(s at presentation and a month later.Results: Two night patrol guards presented to casualty after dog bites in close succession by the same dog. They were managed according to the dog bite protocol. Thinking out of the box, the first victim was found to be HIV positive by rapid test whilst the second victim was negative based on both HIV rapid test and HIV RNA PCR. One month after the dogbites, a case of HIV sero-conversion was confirmed in the second victim despite post-exposure prophylaxis (PEP.Discussion: Although an isolated case, shouldn’t clinicians re-think the significance of HIV transmission after animal bites where there is repeated blood exposure in several people insuccession?Conclusion: Clinicians should be aware of the potential of HIV, Hepatitis B and C transmission, when faced with dog bites in succession. 

  15. Performance potential for simulating spin models on GPU

    CERN Document Server

    Weigel, Martin

    2011-01-01

    Graphics processing units (GPUs) are recently being used to an increasing degree for general computational purposes. This development is motivated by their theoretical peak performance, which significantly exceeds that of broadly available CPUs. For practical purposes, however, it is far from clear how much of this theoretical performance can be realized in actual scientific applications. As is discussed here for the case of studying classical spin models of statistical mechanics by Monte Carlo simulations, only an explicit tailoring of the involved algorithms to the specific architecture under consideration allows to harvest the computational power of GPU systems. A number of examples, ranging from Metropolis simulations of ferromagnetic Ising models, over continuous Heisenberg and disordered spin-glass systems to parallel-tempering simulations are discussed. Significant speed-ups by factors of up to 1000 compared to serial CPU code as well as previous GPU implementations are observed.

  16. Performance potential for simulating spin models on GPU

    Science.gov (United States)

    Weigel, Martin

    2012-04-01

    Graphics processing units (GPUs) are recently being used to an increasing degree for general computational purposes. This development is motivated by their theoretical peak performance, which significantly exceeds that of broadly available CPUs. For practical purposes, however, it is far from clear how much of this theoretical performance can be realized in actual scientific applications. As is discussed here for the case of studying classical spin models of statistical mechanics by Monte Carlo simulations, only an explicit tailoring of the involved algorithms to the specific architecture under consideration allows to harvest the computational power of GPU systems. A number of examples, ranging from Metropolis simulations of ferromagnetic Ising models, over continuous Heisenberg and disordered spin-glass systems to parallel-tempering simulations are discussed. Significant speed-ups by factors of up to 1000 compared to serial CPU code as well as previous GPU implementations are observed.

  17. Presumed prevalence analysis on suspected and highly suspected breast cancer lesions in São Paulo using BIRADS® criteria

    Directory of Open Access Journals (Sweden)

    Vivian Milani

    Full Text Available CONTEXT AND OBJECTIVE: Breast cancer screening programs are critical for early detection of breast cancer. Early detection is essential for diagnosing, treating and possibly curing breast cancer. Since there are no data on the incidence of breast cancer, nationally or regionally in Brazil, our aim was to assess women by means of mammography, to determine the prevalence of this disease. DESIGN AND SETTING: The study protocol was designed in collaboration between the Department of Diagnostic Imaging (DDI, Institute of Diagnostic Imaging (IDI and São Paulo Municipal Health Program. METHODS: A total of 139,945 Brazilian women were assessed by means of mammography between April 2002 and September 2004. Using the American College of Radiology (ACR criteria (Breast Imaging Reporting and Data System, BIRADS®, the prevalence of suspected and highly suspected breast lesions were determined. RESULTS: The prevalence of suspected (BIRADS® 4 and highly suspected (BIRADS® 5 lesions increased with age, especially after the fourth decade. Accordingly, BIRADS® 4 and BIRADS® 5 lesions were more prevalent in the fourth, fifth, sixth and seventh decades. CONCLUSION: The presumed prevalence of suspected and highly suspected breast cancer lesions in the population of São Paulo was 0.6% and it is similar to the prevalence of breast cancer observed in other populations.

  18. Presumed prevalence analysis on suspected and highly suspected breast cancer lesions in São Paulo using BIRADS criteria.

    Science.gov (United States)

    Milani, Vivian; Goldman, Suzan Menasce; Finguerman, Flora; Pinotti, Marianne; Ribeiro, Celso Scazufka; Abdalla, Nitamar; Szejnfeld, Jacob

    2007-07-05

    Breast cancer screening programs are critical for early detection of breast cancer. Early detection is essential for diagnosing, treating and possibly curing breast cancer. Since there are no data on the incidence of breast cancer, nationally or regionally in Brazil, our aim was to assess women by means of mammography, to determine the prevalence of this disease. The study protocol was designed in collaboration between the Department of Diagnostic Imaging (DDI), Institute of Diagnostic Imaging (IDI) and São Paulo Municipal Health Program. A total of 139,945 Brazilian women were assessed by means of mammography between April 2002 and September 2004. Using the American College of Radiology (ACR) criteria (Breast Imaging Reporting and Data System, BIRADS), the prevalence of suspected and highly suspected breast lesions were determined. The prevalence of suspected (BIRADS 4) and highly suspected (BIRADS 5) lesions increased with age, especially after the fourth decade. Accordingly, BIRADS 4 and BIRADS 5 lesions were more prevalent in the fourth, fifth, sixth and seventh decades. The presumed prevalence of suspected and highly suspected breast cancer lesions in the population of São Paulo was 0.6% and it is similar to the prevalence of breast cancer observed in other populations.

  19. Shallow geothermal potential of Cantone Ticino through map modeling

    Science.gov (United States)

    Perego, Rodolfo; Pera, Sebastian; Belliardi, Marco

    2017-04-01

    Low enthalpy geothermal energy is continuously growing in importance within Europe, since it is a reliable and efficient renewable energy, especially when exploited by closed-loop systems. Switzerland hosts one of the greatest density of low temperature geothermal systems in the world. Cantone Ticino includes more than 4000 probes, with an overall installed length of more than 500 km and the requests are continuously growing: the management of this technology must be therefore accurately faced both from a physical and political standpoint. The current authorization approach for closed-loop systems in Cantone Ticino, however, is mainly based on basic maps taking into account the presence of restrictions arising from the enforcement of the water protection act and ordinance. Closed-loop systems cannot be installed within S groundwater protection zones, and within the Au (usable groundwater) sector the installation of such systems is allowed in specific areas where the presence of conflicts precludes groundwater exploitation for drinking purposes. The described procedure, however, does not consider the subsurface potential nor the techno-economic constraints. More empirically based maps could instead give precious planning indications and they could also be useful, if properly verified, to perform pre-emptive estimates of technical and economic parameters. The procedure for the mapping of the geothermal potential started with the identification of the main parameters affecting it, such as the ground surface temperature (GST), thermal conductivity of both outcrops/unconsolidated material and heat flux/geothermal gradient. Maps for all of these parameters were created and some of them were compared with real measurement data, with satisfactory results. The estimated error for the ground temperature reconstruction was quantified in ±1°C, while the error of the hydraulic conductivity reconstruction was estimated as half of an order of magnitude. A reference set of

  20. Universal Behavior of Few-Boson Systems Using Potential Models

    Science.gov (United States)

    Kievsky, A.; Viviani, M.; Álvarez-Rodríguez, R.; Gattobigio, M.; Deltuva, A.

    2017-03-01

    The universal behavior of a three-boson system close to the unitary limit is encoded in a simple dependence of many observables in terms of few parameters. For example the product of the three-body parameter κ _* and the two-body scattering length a, κ _* a depends on the angle ξ defined by E_3/E_2=tan ^2ξ . A similar dependence is observed in the ratio a_{AD}/a with a_{AD} the boson-dimer scattering length. We use a two-parameter potential to determine this simple behavior and, as an application, to compute a_{AD} for the case of three ^4He atoms.

  1. Uterus Transplantation: Potential Patients, Fertility in Animal Models and Ethics

    Directory of Open Access Journals (Sweden)

    Díaz-García C

    2013-01-01

    Full Text Available Uterus transplantation (UTx has been suggested as an alternative to surrogacy to achieve genetic motherhood. Extensive experimental research must be done before any kind of transplantation moves to the clinical field in order to guarantee its safety and effectiveness. Since the final aim of this kind of transplantation is to accomplish motherhood, the success of UTx should be evaluated not only in terms of organ/patient survival but also in terms of functionality, which means that full-term pregnancies with healthy offspring should be considered as the measure of success. In this review we summarize the experimental studies accomplished during the last decade, using fertility as the main outcome, which we consider as the base for further development of UTx towards a clinical setting. Characteristics of potential patients and ethical concerns are also discussed.

  2. MODELING GD-1 GAPS IN A MILKY WAY POTENTIAL

    Energy Technology Data Exchange (ETDEWEB)

    Carlberg, R. G., E-mail: carlberg@astro.utoronto.ca [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada)

    2016-03-20

    The GD-1 star stream is currently the best available for identifying density fluctuations, “gaps,” along its length as a test of the LCDM prediction of large numbers of dark matter sub-halos orbiting in the halo. Density variations of some form are present, since the variance of the density along the stream is three times that expected from the empirically estimated variation in the filtered mean star counts. The density variations are characterized with filters that approximate the shape of sub-halo, gravitationally induced stream gaps. The filters locate gaps and measure their amplitude, leading to a measurement of the distribution of gap widths. To gain an understanding of the factors influencing the gap width distribution, a suite of collisionless n-body simulations for a GD-1-like orbit in a Milky-Way-like potential provides a dynamically realistic statistical prediction of the gap distribution. The simulations show that every location in the stream has been disturbed to some degree by a sub-halo. The small gaps found via the filtering are largely noise. Larger gaps, those longer than 1 kpc, or 10° for GD-1, are the source of the excess variance. The suite of stream simulations shows that sub-halos at the predicted inner halo abundance or possibly somewhat higher can produce the required large-scale density variations.

  3. Modeling GD-1 Gaps in a Milky Way Potential

    Science.gov (United States)

    Carlberg, R. G.

    2016-03-01

    The GD-1 star stream is currently the best available for identifying density fluctuations, “gaps,” along its length as a test of the LCDM prediction of large numbers of dark matter sub-halos orbiting in the halo. Density variations of some form are present, since the variance of the density along the stream is three times that expected from the empirically estimated variation in the filtered mean star counts. The density variations are characterized with filters that approximate the shape of sub-halo, gravitationally induced stream gaps. The filters locate gaps and measure their amplitude, leading to a measurement of the distribution of gap widths. To gain an understanding of the factors influencing the gap width distribution, a suite of collisionless n-body simulations for a GD-1-like orbit in a Milky-Way-like potential provides a dynamically realistic statistical prediction of the gap distribution. The simulations show that every location in the stream has been disturbed to some degree by a sub-halo. The small gaps found via the filtering are largely noise. Larger gaps, those longer than 1 kpc, or 10° for GD-1, are the source of the excess variance. The suite of stream simulations shows that sub-halos at the predicted inner halo abundance or possibly somewhat higher can produce the required large-scale density variations.

  4. Modeling GD-1 Gaps in a Milky-Way Potential

    CERN Document Server

    Carlberg, Raymond G

    2015-01-01

    The GD-1 star stream is currently the best available for identifying density fluctuations, "gaps", along its length as a test of the LCDM prediction of large numbers of dark matter sub-halos orbiting in the halo. Density variations of some form are present, since the variance of the density along the stream is three times that expected from the empirically estimated variation in the filtered mean star counts. The density variations are characterized with filters that approximate the shape of sub-halo induced stream gaps, which locates gaps and measures their amplitude, leading to a measurement of the distribution of gap widths. To gain understanding of the gap width distribution, a suite of n-body simulations for a GD-1 like orbit in a Milky Way-like potential provides a dynamically realistic statistical prediction of the gap distribution. The simulations show that every location in the stream has been disturbed to some degree by a sub-halo. The small gaps emerging from the filtering are largely noise. Larger...

  5. Recombination rates from potential models close to the unitary limit

    CERN Document Server

    Garrido, E; Kievsky, A

    2013-01-01

    We investigate universal behavior in the recombination rate of three bosons close to threshold. Using the He-He system as a reference, we solve the three-body Schr\\"odinger equation above the dimer threshold for different potentials having large values of the two-body scattering length $a$. To this aim we use the hyperspherical adiabatic expansion and we extract the $S$-matrix through the integral relations recently derived. The results are compared to the universal form, $\\alpha\\approx 67.1\\sin^2[s_0\\ln(\\kappa_*a)+\\gamma]$, for different values of $a$ and selected values of the three-body parameter $\\kappa_*$. A good agreement with the universal formula is obtained after introducing a particular type of finite-range corrections, which have been recently proposed by two of the authors in Ref.[1]. Furthermore, we analyze the validity of the above formula in the description of a very different system: neutron-neutron-proton recombination. Our analysis confirms the universal character of the process in systems o...

  6. Current Animal Models of Postoperative Spine Infection and Potential Future Advances.

    Science.gov (United States)

    Stavrakis, A I; Loftin, A H; Lord, E L; Hu, Y; Manegold, J E; Dworsky, E M; Scaduto, A A; Bernthal, N M

    2015-01-01

    Implant related infection following spine surgery is a devastating complication for patients and can potentially lead to significant neurological compromise, disability, morbidity, and even mortality. This paper provides an overview of the existing animal models of postoperative spine infection and highlights the strengths and weaknesses of each model. In addition, there is discussion regarding potential modifications to these animal models to better evaluate preventative and treatment strategies for this challenging complication. Current models are effective in simulating surgical procedures but fail to evaluate infection longitudinally using multiple techniques. Potential future modifications to these models include using advanced imaging technologies to evaluate infection, use of bioluminescent bacterial species, and testing of novel treatment strategies against multiple bacterial strains. There is potential to establish a postoperative spine infection model using smaller animals, such as mice, as these would be a more cost-effective screening tool for potential therapeutic interventions.

  7. Current Animal Models of Postoperative Spine Infection and Potential Future Advances

    Directory of Open Access Journals (Sweden)

    Alexandra eStavrakis

    2015-05-01

    Full Text Available Implant related infection following spine surgery is a devastating complication for patients and can potentially lead to significant neurological compromise, disability, morbidity, and even mortality. This paper provides an overview of the existing animal models of postoperative spine infection and highlights the strengths and weaknesses of each model. In addition there is discussion regarding potential modifications to these animal models to better evaluate preventative and treatment strategies for this challenging complication. Current models are effective in simulating surgical procedures but fail to evaluate infection longitudinally using multiple techniques. Potential future modifications to these models include using advanced imaging technologies to evaluate infection, use of bioluminescent bacterial species, and testing of novel treatment strategies against multiple bacterial strains. There is potential to establish a postoperative spine infection model using smaller animals, such as mice, as these would be a more cost-effective screening tool for potential therapeutic interventions.

  8. Potential climatic impacts of vegetation change: A regional modeling study

    Science.gov (United States)

    Copeland, J.H.; Pielke, R.A.; Kittel, T.G.F.

    1996-01-01

    The human species has been modifying the landscape long before the development of modern agrarian techniques. Much of the land area of the conterminous United States is currently used for agricultural production. In certain regions this change in vegetative cover from its natural state may have led to local climatic change. A regional climate version of the Colorado State University Regional Atmospheric Modeling System was used to assess the impact of a natural versus current vegetation distribution on the weather and climate of July 1989. The results indicate that coherent regions of substantial changes, of both positive and negative sign, in screen height temperature, humidity, wind speed, and precipitation are a possible consequence of land use change throughout the United States. The simulated changes in the screen height quantities were closely related to changes in the vegetation parameters of albedo, roughness length, leaf area index, and fractional coverage. Copyright 1996 by the American Geophysical Union.

  9. Thermal Conductivity of the Potential Repository Horizon Model Report

    Energy Technology Data Exchange (ETDEWEB)

    J. Ramsey

    2002-08-29

    The purpose of this report is to assess the spatial variability and uncertainty of thermal conductivity in the host horizon for the proposed repository at Yucca Mountain. More specifically, the lithostratigraphic units studied are located within the Topopah Spring Tuff (Tpt) and consist of the upper lithophysal zone (Tptpul), the middle nonlithophysal zone (Tptpmn), the lower lithophysal zone (Tptpll), and the lower nonlithophysal zone (Tptpln). The Tptpul is the layer directly above the repository host layers, which consist of the Tptpmn, Tptpll, and the Tptpln. Current design plans indicate that the largest portion of the repository will be excavated in the Tptpll (Board et al. 2002 [157756]). The main distinguishing characteristic among the lithophysal and nonlithophysal units is the percentage of large scale (cm-m) voids within the rock. The Tptpul and Tptpll, as their names suggest, have a higher percentage of lithophysae than the Tptpmn and the Tptpln. Understanding the influence of the lithophysae is of great importance to understanding bulk thermal conductivity and perhaps repository system performance as well. To assess the spatial variability and uncertainty of thermal conductivity, a model is proposed that is functionally dependent on the volume fraction of lithophysae and the thermal conductivity of the matrix portion of the rock. In this model, void space characterized as lithophysae is assumed to be air-saturated under all conditions, while void space characterized as matrix may be either water- or air-saturated. Lithophysae are assumed to be air-saturated under all conditions since the units being studied are all located above the water table in the region of interest, and the relatively strong capillary forces of the matrix will, under most conditions, preferentially retain any moisture present in the rock.

  10. Ensuring proper short-range and asymptotic behavior of the exchange-correlation Kohn-Sham potential by modeling with a statistical average of different orbital model potentials

    Energy Technology Data Exchange (ETDEWEB)

    Gritsenko, O.V.; Schipper, P.R.T.; Baerends, E.J.

    2000-01-20

    The long-range asymptotic behavior of the exchange-correlation Kohn-Sham (KS) potential {nu}{sub xc} and its relation to the exchange-correlation energy E{sub xc} are considered using various approaches. The line integral of {nu}{sub xc}([{rho}];r) yielding the exchange-correlation part {Delta}E{sub xc} of a relative energy {Delta}E of a finite system, shows that a uniform constant shift of {nu}{sub xc} never shows up in any physically meaningful energy difference {Delta}E. {nu}{sub xv} may thus be freely chosen to tend asymptotically to zero or to some nonzero constant. Possible choices of the asymptotics of the potential are discussed with reference to the theory of open systems with a fractional number of electrons. The authors adhere to the conventional choice {nu}{sub xc}({infinity}) = 0 for the asymptotics of the potential leading to {epsilon}{sub N} = {minus}I{sub p} for the energy {epsilon}{sub N} of the highest occupied orbital. A statistical average of orbital dependent model potentials is proposed as a way to model {nu}{sub xc}. An approximate potential {nu}{sub xco}{sup SAOP} with exact {minus}1/r asymptotics is developed using the statistical average of, on the one hand, a model potential {nu}{sub xc{sigma}}{sup Ei} for the highest occupied KS orbital {psi}{sub N{sigma}} and, on the other hand, a model potential {nu}{sub xc}{sup GLB} for other occupied orbitals. It is demonstrated for the well-studied case of the Ne atom, that calculations with the new model potential can, in principle, reproduce perfectly all energy characteristics.

  11. Altered gene expression in human placenta after suspected preterm labour.

    Science.gov (United States)

    Oros, D; Strunk, M; Breton, P; Paules, C; Benito, R; Moreno, E; Garcés, M; Godino, J; Schoorlemmer, J

    2017-07-01

    Suspected preterm labour occurs in around 9% of pregnancies. However, almost two-thirds of women admitted for threatened preterm labour ultimately deliver at term and are considered risk-free for fetal development. We examined placental and umbilical cord blood samples from preterm or term deliveries after threatened preterm labour as well as term deliveries without threatened preterm labour. We quantitatively analysed the mRNA expression of inflammatory markers (IL6, IFNγ, and TNFα) and modulators of angiogenesis (FGF2, PGF, VEGFA, VEGFB, and VEGFR1). A total of 132 deliveries were analysed. Preterm delivery and term delivery after suspected preterm labour groups showed similar increases in TNFα expression compared with the term delivery control group in umbilical cord blood samples. Placental samples from preterm and term deliveries after suspected preterm labour exhibited significantly increased expression of TNFα and IL6 and decreased expression of IFNγ. Suspected preterm labour was also associated with altered expression of angiogenic factors, although not all differences reached statistical significance. We found gene expression patterns indicative of inflammation in human placentas after suspected preterm labour regardless of whether the deliveries occurred preterm or at term. Similarly, a trend towards altered expression of angiogeneic factors was not limited to preterm birth. These findings suggest that the biological mechanisms underlying threatened preterm labour affect pregnancies independently of gestational age at birth. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Suspect online sellers and contraceptive access.

    Science.gov (United States)

    Liang, Bryan A; Mackey, Tim K; Lovett, Kimberly M

    2012-11-01

    Issues surrounding contraception access have been a national focus. During this debate, adolescent and adult women may seek these products online. Due to safety concerns, including potential counterfeit forms, we wished to assess whether online "no prescription" contraceptives were available. We assessed online availability of reversible, prescription contraceptive methods resulting in contraceptives; NuvaRing; Ortho Evra patch; Paragard and Mirena IUDs; and Implanon/Nexplanon implants. Using Google search "buy ITEM no prescription," we reviewed the first five result pages for "no prescription" vendors. Searches were conducted 1/3/2012-2/20/2012. All contraceptives were available as "no prescription" products. Furthermore, IUDs were advertised as "over-the-counter" and YouTube videos provided "how to" videos, including a cartoon version. We also found that illicit online pharmacy marketing is shifting from direct search engine access to social media (Facebook, Twitter, Slidehare, flickr). Online contraceptive sales represent patient safety risks and a parallel system of high-risk product access absent professional guidance. Providers should educate patients, while policy makers employ legal strategies to address these systemic risks. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Chemoautotrophy: Discerning the Key Perpetrators from the Cariaco Redoxcline Lineup of Suspects

    Science.gov (United States)

    Edgcomb, V. P.; Pachiadaki, M.; Taylor, G. T.; Suter, E.

    2016-02-01

    Our polyphasic investigation was designed to characterize microbial communities and metabolic activities across the well-constrained Cariaco Basin redoxcline. We coupled interrogations of microbial functional potential (metagenomics), activity (rate measurements and gene expression), and taxonomic diversity (based on SSU rRNA) to identify the key suspects in chemoautotrophic processes. We infer from these data the microbial impacts on key ecological/geochemical processes. Contrary to popular belief and former testimonials, the epsilon-proteobacteria are not the sole perpetrators, and the gamma-proteobacteria are currently the main suspects. Sulfur oxidation appears to be the main source of energy production and Marine Group A and delta-proteobacteria are implicated as partners in crime regarding cryptic sulfur cycling. Anammox bacteria play a key role in the micro-oxic water layers. Data suggest that even the permanently-stratified Cariaco basin is not a static ecosystem, but instead, one that experiences temporal and spatial perturbations and evolution.

  14. Suspect Height Estimation Using the Faro Focus(3D) Laser Scanner.

    Science.gov (United States)

    Johnson, Monique; Liscio, Eugene

    2015-11-01

    At present, very little research has been devoted to investigating the ability of laser scanning technology to accurately measure height from surveillance video. The goal of this study was to test the accuracy of one particular laser scanner to estimate suspect height from video footage. The known heights of 10 individuals were measured using an anthropometer. The individuals were then recorded on video walking along a predetermined path in a simulated crime scene environment both with and without headwear. The difference between the known heights and the estimated heights obtained from the laser scanner software were compared using a one-way t-test. The height estimates obtained from the software were not significantly different from the known heights whether individuals were wearing headwear (p = 0.186) or not (p = 0.707). Thus, laser scanning is one technique that could potentially be used by investigators to determine suspect height from video footage.

  15. Suspected feigned knee extensor weakness: usefulness of 3D gait analysis. Case report.

    Science.gov (United States)

    Chaler, Joaquim; Müller, Bertram; Maiques, Anna; Pujol, Eduard

    2010-07-01

    The purpose of the present case report is to show the potential for use of 3D gait analysis as an assessment method of feigned muscle weakness. We describe a patient complaining of right leg pain and weakness. Physical examination showed severe quadriceps muscle weakness in a highly abnormal gait pattern context. Conventional diagnostic workup did not show any relevant findings. Three-dimensional (3D) gait analysis was performed with a 3D motion capture system. Joint angles, internal moments and powers were computed from the motion data. Lower leg muscle surface-electromyography was also performed. During the late stance phase, flexor moment and negative power peaks (indicating eccentric knee extensor activity) were generated in the knee, together with relevant Rectus femoris activity. All findings were highly inconsistent with true quadriceps weakness and gave objective ground to suspect insincerity of patient complaints. 3D gait analysis might be a valuable clinical assessment tool in suspected feigned lower limb muscle weakness.

  16. Using urban forest assessment tools to model bird habitat potential

    Science.gov (United States)

    Lerman, Susannah B.; Nislow, Keith H.; Nowak, David J.; Destefano, Stephen; King, David I.; Jones-Farrand, D. Todd

    2014-01-01

    The alteration of forest cover and the replacement of native vegetation with buildings, roads, exotic vegetation, and other urban features pose one of the greatest threats to global biodiversity. As more land becomes slated for urban development, identifying effective urban forest wildlife management tools becomes paramount to ensure the urban forest provides habitat to sustain bird and other wildlife populations. The primary goal of this study was to integrate wildlife suitability indices to an existing national urban forest assessment tool, i-Tree. We quantified available habitat characteristics of urban forests for ten northeastern U.S. cities, and summarized bird habitat relationships from the literature in terms of variables that were represented in the i-Tree datasets. With these data, we generated habitat suitability equations for nine bird species representing a range of life history traits and conservation status that predicts the habitat suitability based on i-Tree data. We applied these equations to the urban forest datasets to calculate the overall habitat suitability for each city and the habitat suitability for different types of land-use (e.g., residential, commercial, parkland) for each bird species. The proposed habitat models will help guide wildlife managers, urban planners, and landscape designers who require specific information such as desirable habitat conditions within an urban management project to help improve the suitability of urban forests for birds.

  17. Echinoderms: potential model systems for studies on muscle regeneration.

    Science.gov (United States)

    García-Arrarás, José E; Dolmatov, Igor Yu

    2010-01-01

    Organisms of the phylum Echinodermata show some of the most impressive regenerative feats within the animal kingdom. Following injury or self-induced autotomy, species in this phylum can regenerate most tissues and organs, being the regeneration of the muscular systems one of the best studied. Even though echinoderms are closely related to chordates, they are little known in the biomedical field, and therefore their uses to study pharmacological effects on muscle formation and/or regeneration have been extremely limited. In order to rectify this lack of knowledge, we describe here the echinoderm muscular systems, particularly the somatic and visceral muscle components. In addition, we provide details of the processes that are known to take place during muscle regeneration, namely dedifferentiation, myogenesis and new muscle formation. Finally, we provide the available information on molecular and pharmacological studies that involve echinoderm muscle regeneration. We expect that by making this information accessible, researchers consider the use of echinoderms as model systems for pharmacological studies in muscle development and regeneration.

  18. ON ONE MODEL OF ADMINISTRATION OF THE JOINT POTENTIAL OF AIRCRAFT ENTERPRISE

    Directory of Open Access Journals (Sweden)

    S. D. Lobanov

    2014-01-01

    Full Text Available The problem of control of the joint potential of airline is examined, the procedure of its estimation taking into account a change in the parameters of external and internal medium is proposed, the comparison of the concepts of joint potential and general objective control function, interrelation of their components is conducted, the model of control of joint potential is proposed.

  19. Method of renormalization potential for one model of Hartree-Fock-Slater type

    CERN Document Server

    Zasorin, Y V

    2002-01-01

    A new method of the potential renormalization for the quasiclassical model of the Hartree-Fock-Slater real potential is proposed. The method makes it possible to easily construct the wave functions and contrary to the majority od similar methods it does not require the knowledge of the real-type potential

  20. Investigation of a suspected outbreak of lipoatrophia semicircularis in children.

    Science.gov (United States)

    Rius, Cristina; Baselga, Eulalia; Tizón, Jorge; Fuentes, Paulina; Muñoz-Garza, Fania Zamantta; Roigé, Glòria; Llebaria, Xavier; Caylà, Joan A

    2017-08-10

    Recent reports of outbreaks of lipoatrophia semicircularis (LS) in various countries have generated discussion regarding the potential role of the environmental characteristics of office workplaces in new buildings. The objective of this study was to investigate a suspected outbreak of LS among children in a public school in Barcelona, which generated tremendous alarm. We performed an epidemiological assessment including descriptive and prevalence analyses, and an environmental investigation followed by a psychiatric assessment according to Small's criteria. We compared the prevalence of LS and its 95% confidence interval between children and staff attending the day-care centre under study and other centres. Among 86 children attending a day-care centre we detected 11 confirmed and 2 possible cases of LS (15.1%) while among 41 children attending other day-care centres we identified 8 cases and 4 possible cases (29.3%) (P=.10). Among 12 day-care staff, we detected 8 cases of LS (66.7%) while among 19 women working different jobs we identified 14 with the same condition as the staff (73.7%) (P=.98). All lesions were finally classified as indentations with different locations. The environmental evaluation didn't identify any exposure factors with a significant role in the onset of the outbreak. The outbreak shared 13 of Small's 16 criteria regarding epidemic somatoform disorder ("mass hysteria"). The presence of indentations can be considered a normal variant in the lower extremities of children. The characteristic development of the process leads us to the conclusion that this outbreak was an epidemic somatoform disorder. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  1. Potential for Application of a Probabilistic Catastrophe Risk Modelling Framework to Poverty Outcomes

    OpenAIRE

    2016-01-01

    This paper analyzes the potential to combine catastrophe risk modelling (CAT risk modeling) with economic analysis of vulnerability to poverty using the example of drought hazard impacts on the welfare of rural households in Ethiopia. The aim is to determine the potential for applying a derived set of damage (vulnerability) functions based on realized shocks and household expenditure/consu...

  2. Three-Body Potentials in {\\varvec{α }}-Particle Model of Light Nuclei

    Science.gov (United States)

    Ishikawa, Souichi

    2017-03-01

    In three-body model calculations of atomic nuclei, e.g., the {}^{12}C nucleus as α -α -α system and the {}9Be nucleus as α -α - n system, the Hamiltonians of the systems consisting of two- and three-body potentials are important inputs. However, our knowledge of three-body potentials is quite restricted. In this paper, I will examine a relation between α -α -α and α -α - n three-body potentials that is obtained in a simple cluster model picture, which gives a phenomenological constraint condition on the three-body potential models to be used.

  3. Animal Model Reveals Potential Waterborne Transmission of Helicobacter pylori Infection.

    Science.gov (United States)

    Boehnke, Kevin F; Eaton, Kathryn A; Valdivieso, Manuel; Baker, Laurence H; Xi, Chuanwu

    2015-10-01

    Helicobacter pylori infection has been consistently associated with lack of access to clean water and proper sanitation, but no studies have demonstrated that the transmission of H. pylori can occur from drinking contaminated water. In this study, we used a laboratory mouse model to test whether waterborne H. pylori could cause gastric infection. Groups of immunocompetent C57/BL6 Helicobacter-free mice were exposed to static concentrations (1.29 × 10(5), 10(6), 10(7), 10(8), and 10(9) CFU/L) of H. pylori in their drinking water for 4 weeks. One group of Helicobacter-free mice was exposed to uncontaminated water as a negative control. H. pylori morphology changes in water were examined using microscopy Live/Dead staining. Following exposure, H. pylori infection and inflammation status in the stomach were evaluated using quantitative culture, PCR, the rapid urease test, and histology. None of the mice in the negative control or 10(5) groups were infected. One of 20 cages (one of 40 mice) of the 10(6) group, three of 19 cages (four of 38 mice) of the 10(7) CFU/L group, 19 of 20 cages (33 of 40 mice) of the 10(8) group, and 20 of 20 cages (39 of 40 mice) of the 10(9) CFU/L group were infected. Infected mice had significantly higher gastric inflammation than uninfected mice (27.86% higher inflammation, p < .0001). We offer proof that H. pylori in water is infectious in mice, suggesting that humans drinking contaminated water may be at risk of contracting H. pylori infection. Much work needs to be performed to better understand the risk of infection from drinking H. pylori-contaminated water. © 2015 John Wiley & Sons Ltd.

  4. Extra-appendiceal findings in pediatric abdominal CT for suspected appendicitis

    Energy Technology Data Exchange (ETDEWEB)

    Halverson, Mark; Delgado, Jorge; Mahboubi, Soroosh [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2014-07-15

    Much has been written regarding the incidence, types, importance and management of abdominal CT incidental findings in adults, but there is a paucity of literature on incidental findings in children. We sought to determine the prevalence and characteristics of extra-appendiceal and incidental findings in pediatric abdominal CT performed for suspected appendicitis. A retrospective review was performed of abdominal CT for suspected appendicitis in a pediatric emergency department from July 2010 to June 2012. Extra-appendiceal findings were recorded. Any subsequent imaging was noted. Extra-appendiceal findings were divided into incidental findings of doubtful clinical significance, alternative diagnostic findings potentially providing a diagnosis other than appendicitis explaining the symptoms, and incidental findings that were abnormalities requiring clinical correlation and sometimes requiring further evaluation but not likely related to the patient symptoms. One hundred sixty-five children had abdominal CT for suspected appendicitis. Seventy-seven extra-appendiceal findings were found in 57 (34.5%) patients. Most findings (64 of 77) were discovered in children who did not have appendicitis. Forty-one of these findings (53%) could potentially help explain the patient's symptoms, while 30 of the findings (39%) were abnormalities that were unlikely to be related to the symptoms but required clinical correlation and sometimes further work-up. Six of the findings (8%) had doubtful or no clinical significance. Extra-appendiceal findings are common in children who undergo abdominal CT in the setting of suspected appendicitis. A significant percentage of these patients have findings that help explain their symptoms. Knowledge of the types and prevalence of these findings may help radiologists in the planning and interpretation of CT examinations in this patient population. (orig.)

  5. Numerical modelling of potential and current distributions in a bipolar electrolytic cell

    OpenAIRE

    Mitha, Eric; Froidevaux, Hubert

    2007-01-01

    This work deals with the modelling of electrochemical reactors with bipolar electrodes. We give a numerical model which enables us to compute electrical current and potential distributions in an electrochemical cell of any type of geometry in two and three dimensions, including electrodes at an unknown floating potential. We first present electrochemical reactors and particularly insist on kinetics and thermodynamics phenomena responsible on potential discontinuities at electrodes-electrolyte...

  6. Numerical modelling of potential and current distributions in a bipolar electrolytic cell

    OpenAIRE

    Mitha, Eric

    1998-01-01

    This work deals with the modelling of electrochemical reactors with bipolar electrodes. We give a numerical model which enables us to compute electrical current and potential distributions in an electrochemical cell of any type of geometry in two and three dimensions, including electrodes at an unknown floating potential. We first present electrochemical reactors and particularly insist on kinetics and thermodynamics phenomena responsible on potential discontinuities at electrodes-electrolyte...

  7. Detecting true lies: police officers' ability to detect suspects' lies.

    Science.gov (United States)

    Mann, Samantha; Vrij, Aldert; Bull, Ray

    2004-02-01

    Ninety-nine police officers, not identified in previous research as belonging to groups that are superior in lie detection, attempted to detect truths and lies told by suspects during their videotaped police interviews. Accuracy rates were higher than those typically found in deception research and reached levels similar to those obtained by specialized lie detectors in previous research. Accuracy was positively correlated with perceived experience in interviewing suspects and with mentioning cues to detecting deceit that relate to a suspect's story. Accuracy was negatively correlated with popular stereotypical cues such as gaze aversion and fidgeting. As in previous research, accuracy and confidence were not significantly correlated, but the level of confidence was dependent on whether officers judged actual truths or actual lies and on the method by which confidence was measured.

  8. Fingerprinting Higgs Suspects at the LHC

    CERN Document Server

    Espinosa, J R; Muhlleitner, M; Trott, Michael

    2012-01-01

    We outline a method for characterizing deviations from the properties of a Standard Model (SM) Higgs boson. We apply it to current data in order to characterize up to which degree the SM Higgs boson interpretation is consistent with experiment. We find that the SM Higgs boson is consistent with the current data set at the 82 % confidence level, based on data of excess events reported by CMS and ATLAS, which are interpreted to be related to the mass scale mh = 124-126 GeV, and on published CL_s exclusion regions. We perform a global fit in terms of two parameters characterizing the deviation from the SM value in the gauge and fermion couplings of a Higgs boson. We find two minima in the global fit and identify observables that can remove this degeneracy. An update for Moriond 2012 data is included in the Appendix, which finds that the SM Higgs boson is now consistent with the current data set at only the 94 % confidence level (which corresponds to ~ 2 sigma tension compared to the best fit point).

  9. Book Review: Placing the Suspect behind the Keyboard: Using Digital Forensics and Investigative Techniques to Identify Cybercrime Suspects

    Directory of Open Access Journals (Sweden)

    Thomas Nash

    2013-06-01

    Full Text Available Shavers, B. (2013. Placing the Suspect behind the Keyboard: Using Digital Forensics and Investigative Techniques to Identify Cybercrime Suspects. Waltham, MA: Elsevier, 290 pages, ISBN-978-1-59749-985-9, US$51.56. Includes bibliographical references and index.Reviewed by Detective Corporal Thomas Nash (tnash@bpdvt.org, Burlington Vermont Police Department, Internet Crime against Children Task Force. Adjunct Instructor, Champlain College, Burlington VT.In this must read for any aspiring novice cybercrime investigator as well as the seasoned professional computer guru alike, Brett Shaver takes the reader into the ever changing and dynamic world of Cybercrime investigation.  Shaver, an experienced criminal investigator, lays out the details and intricacies of a computer related crime investigation in a clear and concise manner in his new easy to read publication, Placing the Suspect behind the Keyboard. Using Digital Forensics and Investigative techniques to Identify Cybercrime Suspects. Shaver takes the reader from start to finish through each step of the investigative process in well organized and easy to follow sections, with real case file examples to reach the ultimate goal of any investigation: identifying the suspect and proving their guilt in the crime. Do not be fooled by the title. This excellent, easily accessible reference is beneficial to both criminal as well as civil investigations and should be in every investigator’s library regardless of their respective criminal or civil investigative responsibilities.(see PDF for full review

  10. Symptomatic Patency Capsule Retention in Suspected Crohn's Disease

    DEFF Research Database (Denmark)

    Rasmussen, Bjørn; Nathan, Torben; Jensen, Michael Dam

    2016-01-01

    The main limitation of capsule endoscopy is the risk of capsule retention. In patients with suspected Crohn's disease, however, this complication is rare, and if a small bowel stenosis is not reliably excluded, small bowel patency can be confirmed with the Pillcam patency capsule. We present two...... patients examined for suspected Crohn's disease who experienced significant symptoms from a retained patency capsule. Both patients had Crohn's disease located in the terminal ileum. In one patient, the patency capsule caused abdominal pain and vomiting and was visualized at magnetic resonance enterography...

  11. Characterization of five cases of suspected bathtub suicide.

    Science.gov (United States)

    Murayama, Masayuki; Takahashi, Yoichiro; Sano, Rie; Watanabe, Kaho; Takahashi, Keiko; Kubo, Rieko; Kuninaka, Hikaru; Kominato, Yoshihiko

    2015-11-01

    We reviewed five autopsy cases of suspected bathtub suicide. The immediate cause of death in all cases was determined to be drowning on the basis of macropathological findings such as frothy fluid in the airways or overinflation of the lungs as well as histological findings obtained at autopsy. We suspected that the manner of death in those cases was suicide based on comprehensive postmortem investigations of statements from witnesses, the presence of a farewell letter, the fact that clothes had been worn, additional means to ensure suicide, and results of drug tests, as well as autopsy findings. Cases of bathtub suicide should be investigated carefully to distinguish them from accidental or natural death.

  12. Cholescintigraphy and ultrasonography in patients suspected of having acute cholecystitis

    DEFF Research Database (Denmark)

    Lauritsen, K B; Sommer, W; Hahn, L;

    1988-01-01

    The diagnostic power of combined cholescintigraphy and ultrasonography was tested in 67 patients suspected of having acute cholecystitis; of these, 42 (63%) had acute cholecystitis. The predictive value of a positive scintigraphy (PVpos) was 95% and that of a negative (PVneg) was 91% (n = 67...... that in patients suspected of having acute cholecystitis cholescintigraphy should be the first diagnostic procedure performed. If the scintigraphy is positive, additional ultrasonographic detection of gallstones makes the diagnosis almost certain. If one diagnostic modality is inconclusive, the other makes a fair...

  13. Proposed diagnostic algorithm for patients with suspected mastocytosis

    DEFF Research Database (Denmark)

    Valent, P; Escribano, L; Broesby-Olsen, S

    2014-01-01

    a diagnostic challenge. In the light of this unmet need, we developed a diagnostic algorithm for patients with suspected mastocytosis. In adult patients with typical lesions of mastocytosis in the skin, a bone marrow (BM) biopsy should be considered, regardless of the basal serum tryptase concentration...... is usually not required, even if the tryptase level is increased. Although validation is required, it can be expected that the algorithm proposed herein will facilitate the management of patients with suspected mastocytosis and help avoid unnecessary referrals and investigations....

  14. Current Animal Models of Postoperative Spine Infection and Potential Future Advances

    OpenAIRE

    Stavrakis, A. I.; Loftin, A. H.; Lord, E. L.; Hu, Y; Manegold, J. E.; Dworsky, E. M.; Scaduto, A. A.; Bernthal, N. M.

    2015-01-01

    Implant related infection following spine surgery is a devastating complication for patients and can potentially lead to significant neurological compromise, disability, morbidity, and even mortality. This paper provides an overview of the existing animal models of postoperative spine infection and highlights the strengths and weaknesses of each model. In addition, there is discussion regarding potential modifications to these animal models to better evaluate preventative and treatment strate...

  15. Pathogen Identification in Suspected Cases of Pyogenic Spondylodiscitis

    Science.gov (United States)

    Sheikh, Ahmad Farajzadeh; Khosravi, Azar D.; Goodarzi, Hamed; Nashibi, Roohangiz; Teimouri, Alireaza; Motamedfar, Azim; Ranjbar, Reza; Afzalzadeh, Sara; Cyrus, Mehrandokht; Hashemzadeh, Mohammad

    2017-01-01

    Pyogenic spinal infection continues to represent a worldwide problem. In approximately one-third of patients with pyogenic spondylodiscitis, the infectious agent is never identified. Of the cases that lead to organismal identification, bacteria are more commonly isolated from the spine rather than fungi and parasites. This study applied universal prokaryotic 16S rRNA PCR as a rapid diagnostic tool for the detection of bacterial agents in specimens from patients suspected of pyogenic spondylodiscitis. Gram and Ziehl-Neelsen staining were used as a preliminary screening measure for microbiologic evaluation of patient samples. PCR amplification targeting 16S rRNA gene was performed on DNA extracted from 57 cases including specimens from epidural abscesses, vertebral, and disc biopsies. Positive samples were directly sequenced. MRI findings demonstrated that disc destruction and inflammation were the major imaging features of suspected pyogenic spondylodiscitis cases, as 44 cases showed such features. The most common site of infection was the lumbar spine (66.7%), followed by thoracic spine (19%), the sacroiliac joint (9.5%), and lumbar-thoracic spine (4.8%) regions. A total of 21 samples amplified the 16S rRNA-PCR product. Sanger sequencing of the PCR products identified the following bacteriological agents: Mycobacterium tuberculosis (n = 9; 42.9%), Staphylococcus aureus (n = 6; 28.5%), Mycobacterium abscessus (n = 5; 23.8%), and Mycobacterium chelonae (n = 1; 4.8%). 36 samples displayed no visible 16S rRNA PCR signal, which suggested that non-bacterial infectious agents (e.g., fungi) or non-infectious processes (e.g., inflammatory, or neoplastic) may be responsible for some of these cases. The L3–L4 site (23.8%) was the most frequent site of infection. Single disc/vertebral infection were observed in 9 patients (42.85%), while 12 patients (57.15%) had 2 infected adjacent vertebrae. Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP

  16. Views on clinically suspect arthralgia: a focus group study.

    Science.gov (United States)

    Newsum, Elize C; van der Helm-van Mil, Annette H M; Kaptein, Adrian A

    2016-05-01

    The rheumatology field is moving towards identifying individuals with an increased risk for rheumatoid arthritis (RA) at a stage when arthritis is still absent but persons having clinically suspect arthralgia (CSA). Incorporating patients' views in rheumatologic care is pivotal; however, the views of persons with CSA on their condition are unknown. We aimed to help fill this gap by exploring illness perceptions of persons with CSA and their views on hypothetical prognoses for developing RA. Persons with CSA were invited to participate in a semi-structured focus group discussion. Illness perceptions according to the Common Sense Model (CSM) and four a priori formulated themes were explored in detail during the group discussion. The discussion was audio-taped and transcribed verbatim. Transcripts were analysed in an interpretative phenomenological approach manner, on the basis of the dimensions of the CSM by three researchers independently. The views of four participants with CSA were explored during one focus group discussion. Four dimensions of the CSM were mainly observed: Identity, Consequences, Personal Control and Concern. None of the patients identified themselves as being a patient. They did experience pain and impairments in daily functioning and were concerned that their symptoms would progress. In the absence of physician-initiated treatment, some patients changed lifestyle in order to reduce pain and to promote health. Patients unanimously said that they could not interpret prognostic information on RA development expressed in hypothetical chances. Persons with CSA do not consider themselves patients. Prognostic information related to the development of RA based on risk percentages was considered as not useful by persons with CSA. Understanding of the illness perceptions of persons with CSA by health care professionals might improve medical management and facilitate shared decision-making.

  17. Screening for keratoconus suspects among candidates for refractive surgery.

    Science.gov (United States)

    McMonnies, Charles W

    2014-11-01

    This review examines methods for estimating the risk of post-surgical ectasia in candidates for refractive surgery by establishing a diagnosis of keratoconus suspect as a contraindication for proceeding with surgery. Notwithstanding the desirability of achieving 100 per cent sensitivity, any associated reduction in specificity and increased numbers of false positives might deny some candidates the opportunity to proceed with refractive surgery. The introduction of a model for the risk of ectasia involving both pre- and post-surgical findings has been followed by a plethora of attempts to achieve the same purpose based on topographic and/or tomographic evaluation before surgery. The desirability of being able to depend on objective assessment using one type of instrument needs to be weighed against the possibility that subjective assessments may contribute significantly to screening success. For example, consideration of ethnicity, family history of keratoconus, a history of atopy or ocular allergies in particular, a history of significant exposure to corneal trauma associated with abnormal rubbing habits or with vocational, leisure or geographically increased exposure to ultraviolet radiation or with contact lens wear trauma or a history of significant exposure to activities which elevate intraocular pressure may improve screening success. To the extent that these factors could contribute to increased risk of the development of keratoconus, they may be useful in estimating the risk of post-surgical ectasia. If any combination of these factors helps to explain the development of keratoconus in normal or even thicker than normal corneas, they may have more significance for those corneas, which have been thinned surgically.

  18. A new method for screening potential sII and sH hydrogen clathrate hydrate promoters with model potentials.

    Science.gov (United States)

    Frankcombe, Terry J; Kroes, Geert-Jan

    2011-08-01

    A new predictive computational method for classifying clathrate hydrate promoter molecules is presented, based on the interaction energies between potential promoters and the water networks of sII and sH clathrates. The motivation for this work is identifying promoters for storing hydrogen compactly in clathrate hydrates. As a first step towards achieving this goal, we have developed a general method aimed at distinguishing between molecules that form sII clathrate hydrates and molecules that can-together with a weakly interacting help gas-form sH clathrate hydrates. The new computational method calculates differences in estimated formation energies of the sII and the sH clathrate hydrate. Model interaction potentials have been used, including the electrostatic interactions with newly calculated partial charges for all the considered potential promoter molecules. The methodology can discriminate between the clathrate structure types (sII or sH) formed by each potential promoter with good selectivity, i.e., better than achieved with a simple van der Waals diameter criterion.

  19. The Kronig-Penney model extended to arbitrary potentials via numerical matrix mechanics

    Science.gov (United States)

    Pavelich, R. L.; Marsiglio, F.

    2015-09-01

    The Kronig-Penney model is a common starting point for studying the quantum mechanics of electrons in a confining periodic potential. This model uses a square-well potential; the energies and eigenstates can be obtained analytically for a single well, and then Bloch's theorem allows one to extend these solutions to the periodically repeating potential. In this work, we describe how to obtain simple numerical solutions for the eigenvalues and eigenstates for any confining one-dimensional potential within a unit cell and then extend this procedure, with virtually no extra effort, to the case of arbitrary periodically repeating potentials. In this way, one can study the band structure effects that arise from differently shaped potentials. One of these effects is the electron-hole mass asymmetry; more realistic unit cell potentials generally give rise to higher electron-hole mass asymmetries.

  20. Suspected Nonalcoholic Fatty Liver Disease Is Not Associated with Vitamin D Status in Adolescents after Adjustment for Obesity

    Directory of Open Access Journals (Sweden)

    Karin Katz

    2010-01-01

    Full Text Available This study investigated a potential independent association between hypovitaminosis D and suspected nonalcoholic fatty liver disease (NAFLD in a nationally representative sample of the US adolescents. Data from 1630 subjects 12–19 years of age were examined using the National Health and Nutrition Examination Survey, 2001–2004. The vitamin D status of subjects was categorized into quartiles of serum 25-hydroxyvitamin D. Subjects with serum ALT>30 U/L were classified as having suspected NAFLD. Data regarding age, sex, race, BMI, and poverty level were also analyzed in bivariate and multivariate analyses using SAS and SUDAAN software. Suspected NAFLD was identified in 12.1% of adolescents in the lowest quartile compared to 6.9% of adolescents in the second quartile, 8.0% in the third quartile, and 13.17% in the highest quartile of serum 25(OHD concentrations (=.05. In analyses utilizing vitamin D as a continuous variable, no independent association was found between Vitamin D levels and rates of elevated ALT levels. In multivariate analyses, higher risks for suspected NAFLD were observed in males and overweight adolescents; however, vitamin D status was not found to be independently associated with suspected NAFLD after adjusting for obesity.

  1. Assessing potential modifications of landslide triggering probability based on hydromechanical modelling and regional climate model projections

    Science.gov (United States)

    Peres, David Johnny; Cancelliere, Antonino

    2017-04-01

    Climate change related to uncontrolled greenhouse gas emissions is expected to modify climate characteristics in a harmful way, increasing the frequency of many precipitation-triggered natural hazards, landslides included. In our study we analyse regional climate model (RCM) projections with the aim of assessing the potential future modifications of rainfall event characteristics linked to shallow landslide triggering, such as: event duration, total depth, and inter-arrival time. Factor of changes of the mean and the variance of these rainfall-event characteristics are exploited to adjust a stochastic rainfall generator aimed at simulating precipitation series likely to occur in the future. Then Monte Carlo simulations - where the stochastic rainfall generator and a physically based hydromechanical model are coupled - are carried out to estimate the probability of landslide triggering for future time horizons, and its changes respect to the current climate conditions. The proposed methodology is applied to the Peloritani region in Sicily, Italy, an area that in the past two decades has experienced several catastrophic shallow and rapidly moving landslide events. Different RCM simulations from the Coordinated regional Climate Downscaling Experiment (CORDEX) initiative are considered in the application, as well as two different emission scenarios, known as Representative Concentration Pathways: intermediate (RCP 4.5) and high-emissions (RCP 8.5). The estimated rainfall event characteristics modifications differ significantly both in magnitude and in direction (increase/decrease) from one model to another. RCMs are concordant only in predicting an increase of the mean of inter-event dry intervals. The variance of rainfall depth exhibits maximum changes (increase or decrease depending on the RCM), and it is the characteristic to which landslide triggering seems to be more sensitive. Some RCMs indicate significant variations of landslide probability due to climate

  2. A comparative assessment of GIS-based data mining models and a novel ensemble model in groundwater well potential mapping

    Science.gov (United States)

    Naghibi, Seyed Amir; Moghaddam, Davood Davoodi; Kalantar, Bahareh; Pradhan, Biswajeet; Kisi, Ozgur

    2017-05-01

    In recent years, application of ensemble models has been increased tremendously in various types of natural hazard assessment such as landslides and floods. However, application of this kind of robust models in groundwater potential mapping is relatively new. This study applied four data mining algorithms including AdaBoost, Bagging, generalized additive model (GAM), and Naive Bayes (NB) models to map groundwater potential. Then, a novel frequency ratio data mining ensemble model (FREM) was introduced and evaluated. For this purpose, eleven groundwater conditioning factors (GCFs), including altitude, slope aspect, slope angle, plan curvature, stream power index (SPI), river density, distance from rivers, topographic wetness index (TWI), land use, normalized difference vegetation index (NDVI), and lithology were mapped. About 281 well locations with high potential were selected. Wells were randomly partitioned into two classes for training the models (70% or 197) and validating them (30% or 84). AdaBoost, Bagging, GAM, and NB algorithms were employed to get groundwater potential maps (GPMs). The GPMs were categorized into potential classes using natural break method of classification scheme. In the next stage, frequency ratio (FR) value was calculated for the output of the four aforementioned models and were summed, and finally a GPM was produced using FREM. For validating the models, area under receiver operating characteristics (ROC) curve was calculated. The ROC curve for prediction dataset was 94.8, 93.5, 92.6, 92.0, and 84.4% for FREM, Bagging, AdaBoost, GAM, and NB models, respectively. The results indicated that FREM had the best performance among all the models. The better performance of the FREM model could be related to reduction of over fitting and possible errors. Other models such as AdaBoost, Bagging, GAM, and NB also produced acceptable performance in groundwater modelling. The GPMs produced in the current study may facilitate groundwater exploitation

  3. Model for estimation of enterprise management system potential: description and study

    Directory of Open Access Journals (Sweden)

    N.G. Kalyuzhna

    2016-06-01

    Full Text Available The aim of the article. The main purpose of the article is the description of the model for estimation of enterprise management system potential, based on fuzzy logic, and studying its behavior at critical points. The results of the analysis. In the article it is proved that the enterprise management system potential is a strategic basis for the formation of the overall enterprise potential. In this context, the importance of solving the problem of quantitative evaluation of enterprise management system potential obviously increases. In the article, the existence of a number of approaches to evaluating enterprise management system potential is demonstrated. Most of these approaches meet the author's conception of the nature of such instruments. Specifically, these approaches involve the estimating both subjective and objective component of management processes and based on the calculation of the indicators, reflecting the actual performance of management. However, most of the investigated approaches are not reflect the correspondence between components of management system potential and elements of management systems. In the article, the components of management system potential are ordered into the units according to the same nature (objective, subjective and combined components. The enterprise management system potential is considered as a function of the potentials of its constituent units. As these units is proposed to consider: the informative and technical potential (objective component, the structural and functional potential (objective component, the management personnel potential (subjective component, the potential of preparing, adoption and implementation of management decisions (combined component. According to the fact that the enterprise management system potential is not quantifiable variable, it is advisable the feasibility of fuzzy logic for its evaluation. In order to quantify the enterprise management system potential as a

  4. Exploring the potential of multivariate depth-damage and rainfall-damage models

    DEFF Research Database (Denmark)

    van Ootegem, Luc; van Herck, K.; Creten, T.

    2017-01-01

    In Europe, floods are among the natural catastrophes that cause the largest economic damage. This article explores the potential of two distinct types of multivariate flood damage models: ‘depth-damage’ models and ‘rainfall-damage’ models. We use survey data of 346 Flemish households that were vi...

  5. A dynamic model of potential growth of olive (Olea europaea L.) orchards

    NARCIS (Netherlands)

    Morales Sierra, Alejandro; Leffelaar, Peter A.; Testi, Luca; Orgaz, Francisco; Villalobos, Francisco J.

    2016-01-01

    A model of potential olive oil production is presented, based on a three-dimensional model of canopy photosynthesis and respiration and dynamic distribution of assimilates among organs. The model is used to analyse the effects of planting density (high and super-high density orchards with 408 and

  6. A dynamic model of potential growth of olive (Olea europaea L.) orchards

    NARCIS (Netherlands)

    Morales Sierra, Alejandro; Leffelaar, Peter A.; Testi, Luca; Orgaz, Francisco; Villalobos, Francisco J.

    2016-01-01

    A model of potential olive oil production is presented, based on a three-dimensional model of canopy photosynthesis and respiration and dynamic distribution of assimilates among organs. The model is used to analyse the effects of planting density (high and super-high density orchards with 408 and

  7. THE MATHEMATIC MODEL OF POTENTIAL RELAXATION IN COULOSTATIC CONDITIONS FOR LIMITING DIFFUSION CURRENT CASE

    Directory of Open Access Journals (Sweden)

    O. H. Kapitonov

    2010-05-01

    Full Text Available A mathematical model of coulostatic relaxation of the potential for solid metallic electrode was presented. The solution in the case of limiting diffusion current was obtained. On the basis of this model the technique of concentration measurements for heavy metal ions in diluted solutions was suggested. The model adequacy was proved by experimental data.

  8. [Diagnostic strategy in patients with clinically suspected deep vein thrombosis

    DEFF Research Database (Denmark)

    Mantoni, Margit Yvonne; Kristensen, M.; Brogaard, M.H.;

    2008-01-01

    . MATERIALS AND METHODS: A total of 508 consecutive patients presenting in the emergency room with suspected DVT had D-dimer and DVT-score performed. Patients with non-elevated D-dimer and a low or moderate DVT score received no treatment. The remainder had ultrasound scanning from the groin to the popliteal...

  9. Pulmonary mycoses among the clinically suspected cases of pulmonary tuberculosis

    Directory of Open Access Journals (Sweden)

    Tshering Ongmu Bhutia

    2015-01-01

    Full Text Available Background: This study was carried with the main objectives: (1 to find out the occurrence of pulmonary mycoses in clinically suspected pulmonary tuberculosis cases at central referral hospital, Tadong, Sikkim. (2 To find out the various fungi causing pulmonary mycoses in clinically suspected pulmonary tuberculosis cases. Methods: 200 clinically suspected pulmonary tuberculosis cases who visited the department of microbiology for the diagnostic microscopic examination of sputum sample for acid fast bacilli were included in this cross sectional study, carried out under the department of microbiology, Sikkim Manipal institute of medical sciences, over one year. Smears of sputum samples were examined microscopically for acid fast bacilli and fungal elements. Sputum samples were also plated onto different fungal culture media. Results: Out of 200 patients, various types of pathogens were detected in 54 (27% patients. Fourteen (7% patients were positive only for AFB, while fungus as a primary etiological agent was detected in 16(8% patients. Fungus as a secondary etiological agent was detected in 4 (2% patients [AFB with fungus in 2 (1%, AFB with fungus and bacteria in 1 (0.5% and bacteria with fungus in 1 (0.5% patient]. Conclusion: Pulmonary mycosis can be a primary infection in non- tuberculosis cases or co-infection in pulmonary tuberculosis cases. Investigation for fungal cause in clinically suspected cases of pulmonary tuberculosis will prevent misdiagnosis and mistreatment of cases. [Int J Res Med Sci 2015; 3(1.000: 260-268

  10. Correlates and Suspected Causes of Obesity in Children

    Science.gov (United States)

    Crothers, Laura M.; Kehle, Thomas J.; Bray, Melissa A.; Theodore, Lea A.

    2009-01-01

    The correlates and suspected causes of the intractable condition obesity are complex and involve environmental and heritable, psychological and physical variables. Overall, the factors associated with and possible causes of it are not clearly understood. Although there exists some ambiguity in the research regarding the degree of happiness in…

  11. A suspected case of Addison's disease in cattle.

    Science.gov (United States)

    Lambacher, Bianca; Wittek, Thomas

    2015-09-01

    A 4.75-year old Simmental cow was presented with symptoms of colic and ileus. The clinical signs and blood analysis resulted in the diagnosis of suspected primary hypoadrenocorticism (Addison's disease). Although Addison's disease has been frequently described in other domestic mammals, to our knowledge, this disease has not previously been reported in cattle.

  12. Differential Diagnosis of Children with Suspected Childhood Apraxia of Speech

    Science.gov (United States)

    Murray, Elizabeth; McCabe, Patricia; Heard, Robert; Ballard, Kirrie J.

    2015-01-01

    Purpose: The gold standard for diagnosing childhood apraxia of speech (CAS) is expert judgment of perceptual features. The aim of this study was to identify a set of objective measures that differentiate CAS from other speech disorders. Method: Seventy-two children (4-12 years of age) diagnosed with suspected CAS by community speech-language…

  13. Cognitive Linguistic Performances of Multilingual University Students Suspected of Dyslexia

    Science.gov (United States)

    Lindgren, Signe-Anita; Laine, Matti

    2011-01-01

    High-performing adults with compensated dyslexia pose particular challenges to dyslexia diagnostics. We compared the performance of 20 multilingual Finnish university students with suspected dyslexia with 20 age-matched and education-matched controls on an extensive test battery. The battery tapped various aspects of reading, writing, word…

  14. DNA typing from vaginal smear slides in suspected rape cases

    Directory of Open Access Journals (Sweden)

    Dayse Aparecida da Silva

    Full Text Available In an investigation of suspected rape, proof of sexual assault with penetration is required. In view of this, detailed descriptions of the genitalia, the thighs and pubic region are made within the forensic medical service. In addition, vaginal swabs are taken from the rape victim and some of the biological material collected is then transferred to glass slides. In this report, we describe two rape cases solved using DNA typing from cells recovered from vaginal smear slides. In 1999, two young women informed the Rio de Janeiro Police Department that they had been victims of sexual assaults. A suspect was arrested and the victims identified him as the offender. The suspect maintained that he was innocent. In order to elucidate these crimes, vaginal smear slides were sent to the DNA Diagnostic Laboratory for DNA analysis three months after the crimes, as unique forensic evidence. To get enough epithelial and sperm cells to perform DNA analysis, we used protocols modified from the previously standard protocols used for DNA extraction from biological material fixed on glass slides. The quantity of cells was sufficient to perform human DNA typing using nine short tandem repeat (STR loci. It was 3.3 billion times more probable that it was the examined suspect who had left sperm cells in the victims, rather than any other individual in the population of Rio de Janeiro.

  15. Selective screening in neonates suspected to have inborn errors of ...

    African Journals Online (AJOL)

    Rabah M. Shawky

    2015-02-16

    Feb 16, 2015 ... specificity over existing methods, and its suitability for cost- effective multidisease ... clinical examination, laboratory investigations including com- plete blood count ... Analysis of data was performed using standard computer pro- .... suspected obstructed labor, the 2nd was a female who had hypo activity ...

  16. Cognitive Linguistic Performances of Multilingual University Students Suspected of Dyslexia

    Science.gov (United States)

    Lindgren, Signe-Anita; Laine, Matti

    2011-01-01

    High-performing adults with compensated dyslexia pose particular challenges to dyslexia diagnostics. We compared the performance of 20 multilingual Finnish university students with suspected dyslexia with 20 age-matched and education-matched controls on an extensive test battery. The battery tapped various aspects of reading, writing, word…

  17. Correlates and Suspected Causes of Obesity in Children

    Science.gov (United States)

    Crothers, Laura M.; Kehle, Thomas J.; Bray, Melissa A.; Theodore, Lea A.

    2009-01-01

    The correlates and suspected causes of the intractable condition obesity are complex and involve environmental and heritable, psychological and physical variables. Overall, the factors associated with and possible causes of it are not clearly understood. Although there exists some ambiguity in the research regarding the degree of happiness in…

  18. Assessment of some optical model potentials in predicting neutron cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, A.; Young, P.G.; Chadwick, M.B.

    1998-03-01

    Optical model potential parameters play an important role in the evaluation of nuclear data for applied purposes. The IAEA Coordinated Research Program on {open_quotes}Reference Input Parameter Library for Evaluation of Nuclear Data for Application in Nuclear Technology{close_quotes} aims to release a reference input file of various types of parameters for the evaluation of nuclear cross sections using nuclear model codes. Included in the parameter files are a collection of optical model potentials that are available in the literature to evaluate these cross sections. As part of this research program we assess the applicability of these potentials over a range of target mass and projectile energy.

  19. Opioid analgesic administration in patients with suspected drug use.

    Science.gov (United States)

    Kreling, Maria Clara Giorio Dutra; Mattos-Pimenta, Cibele Andrucioli de

    2017-01-01

    To identify the prevalence of patients suspected of drug use according to the nursing professionals' judgement, and compare the behavior of these professionals in opioid administration when there is or there is no suspicion that patient is a drug user. A cross-sectional study with 507 patients and 199 nursing professionals responsible for administering drugs to these patients. The Chi-Square test, Fisher's Exact and a significance level of 5% were used for the analyzes. The prevalence of suspected patients was 6.7%. The prevalence ratio of administration of opioid analgesics 'if necessary' is twice higher among patients suspected of drug use compared to patients not suspected of drug use (p = 0.037). The prevalence of patients suspected of drug use was similar to that of studies performed in emergency departments. Patients suspected of drug use receive more opioids than patients not suspected of drug use. Identificar a prevalência de pacientes com suspeita de uso de drogas conforme opinião de profissionais de enfermagem e comparar a conduta desses profissionais na administração de opioides quando há ou não suspeita de que o paciente seja usuário de drogas. Estudo transversal com 507 pacientes e 199 profissionais de enfermagem responsáveis pela administração de medicamentos a esses pacientes. Para as análises foram utilizados os testes de Qui-Quadrado, Exato de Fisher e um nível de significância de 5%. A prevalência de pacientes suspeitos foi 6,7%. A razão de prevalência de administração de analgésicos opioides "se necessário" é duas vezes maior entre os pacientes suspeitos em relação aos não suspeitos (p=0,037). A prevalência de suspeitos foi semelhante à de estudos realizados em departamentos de emergência. Os suspeitos de serem usuários de drogas recebem mais opioides do que os não suspeitos.

  20. Economic evaluation of a clinical protocol for diagnosing emergency patients with suspected pulmonary embolism

    Directory of Open Access Journals (Sweden)

    Wolfe Rory

    2006-06-01

    Full Text Available Abstract Background The objective of this paper is to estimate the amount of cost-savings to the Australian health care system from implementing an evidence-based clinical protocol for diagnosing emergency patients with suspected pulmonary embolism (PE at the Emergency department of a Victorian public hospital with 50,000 presentations in 2001–2002. Methods A cost-minimisation study used the data collected in a controlled clinical trial of a clinical protocol for diagnosing patients with suspected PE. Thenumber and type of diagnostic tests in a historic cohort of 185 randomly selected patients, who presented to the emergency department with suspectedPE during an eight month period prior to the clinical trial (January 2002 -August 2002 were compared with the number and type of diagnostic tests in745 patients, who presented to the emergency department with suspected PE from November 2002 to August 2003. Current Medicare fees per test were usedas unit costs to calculate the mean aggregated cost of diagnostic investigation per patient in both study groups. A t-test was used to estimate the statistical significance of the difference in the cost of resources used for diagnosing PE in the control and in the intervention group. Results The trial demonstrated that diagnosing PE using an evidence-based clinical protocol was as effective as the existing clinical practice. The clinical protocol offers the advantage of reducing the use of diagnostic imaging, resulting in an average cost savings of at least $59.30 per patient. Conclusion Extrapolating the observed cost-savings of $59.30 per patient to the wholeof Australia could potentially result in annual savings between $3.1 million to $3.7 million.

  1. Linear Sigma Model at Finite Temperature and Baryonic Chemical Potential Using the N-Midpoint Technique

    Directory of Open Access Journals (Sweden)

    M. Abu-Shady

    2014-01-01

    Full Text Available A baryonic chemical potential (μb is included in the linear sigma model at finite temperature. The effective mesonic potential is numerically calculated using the N-midpoint rule. The meson masses are investigated as functions of the temperature (T at fixed value of baryonic chemical potential. The pressure and energy density are investigated as functions of temperature at fi…xed value of μb. The obtained results are in good agreement in comparison with other techniques. We conclude that the calculated effective potential successfully predicts the meson properties and thermodynamic properties at finite baryonic chemical potential.

  2. Modelling streambank erosion potential using maximum entropy in a central Appalachian watershed

    Science.gov (United States)

    Pitchford, J.; Strager, M.; Riley, A.; Lin, L.; Anderson, J.

    2015-03-01

    We used maximum entropy to model streambank erosion potential (SEP) in a central Appalachian watershed to help prioritize sites for management. Model development included measuring erosion rates, application of a quantitative approach to locate Target Eroding Areas (TEAs), and creation of maps of boundary conditions. We successfully constructed a probability distribution of TEAs using the program Maxent. All model evaluation procedures indicated that the model was an excellent predictor, and that the major environmental variables controlling these processes were streambank slope, soil characteristics, bank position, and underlying geology. A classification scheme with low, moderate, and high levels of SEP derived from logistic model output was able to differentiate sites with low erosion potential from sites with moderate and high erosion potential. A major application of this type of modelling framework is to address uncertainty in stream restoration planning, ultimately helping to bridge the gap between restoration science and practice.

  3. Detecting single-trial EEG evoked potential using a wavelet domain linear mixed model: application to error potentials classification

    Science.gov (United States)

    Spinnato, J.; Roubaud, M.-C.; Burle, B.; Torrésani, B.

    2015-06-01

    Objective. The main goal of this work is to develop a model for multisensor signals, such as magnetoencephalography or electroencephalography (EEG) signals that account for inter-trial variability, suitable for corresponding binary classification problems. An important constraint is that the model be simple enough to handle small size and unbalanced datasets, as often encountered in BCI-type experiments. Approach. The method involves the linear mixed effects statistical model, wavelet transform, and spatial filtering, and aims at the characterization of localized discriminant features in multisensor signals. After discrete wavelet transform and spatial filtering, a projection onto the relevant wavelet and spatial channels subspaces is used for dimension reduction. The projected signals are then decomposed as the sum of a signal of interest (i.e., discriminant) and background noise, using a very simple Gaussian linear mixed model. Main results. Thanks to the simplicity of the model, the corresponding parameter estimation problem is simplified. Robust estimates of class-covariance matrices are obtained from small sample sizes and an effective Bayes plug-in classifier is derived. The approach is applied to the detection of error potentials in multichannel EEG data in a very unbalanced situation (detection of rare events). Classification results prove the relevance of the proposed approach in such a context. Significance. The combination of the linear mixed model, wavelet transform and spatial filtering for EEG classification is, to the best of our knowledge, an original approach, which is proven to be effective. This paper improves upon earlier results on similar problems, and the three main ingredients all play an important role.

  4. A generalized gradient approximation for exchange derived from the model potential of van Leeuwen and Baerends

    Science.gov (United States)

    Gaiduk, Alex P.; Staroverov, Viktor N.

    2012-02-01

    The common way to obtain energies from Kohn-Sham exchange potentials is by using the Levy-Perdew virial relation. For potentials that are not functional derivatives (i.e., nearly all model exchange potentials in existence), this approach leads to energy expressions that lack translational and rotational invariance. We propose a method for constructing potential-based energy functionals that are free from these artifacts. It relies on the same line-integration technique that gives rise to the Levy-Perdew relation, but uses density scaling instead of coordinate scaling. The method is applicable to any exchange or correlation potential that depends on the density explicitly, and correctly recovers the parent energy functional from a functional derivative. To illustrate our approach we develop a properly invariant generalized gradient approximation for exchange starting from the model potential of van Leeuwen and Baerends.

  5. Potential Vorticity based parameterization for specification of Upper troposphere/lower stratosphere ozone in atmospheric models

    Data.gov (United States)

    U.S. Environmental Protection Agency — Potential Vorticity based parameterization for specification of Upper troposphere/lower stratosphere ozone in atmospheric models - the data set consists of 3D O3...

  6. Iso-spin Dependent Microscopic Optical Model Potential Based on Dirac Bruckner Haretree Fock Method

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The microscopic optical model is investigated in the Dirac-Brueckner-Hartree-Fock (DBHF) framework with Bonn B meson exchange potential. Both real and imaginary parts of isospin-dependent self-energies are derived from a strict projection

  7. Development of a Kohn-Sham like potential in the Self-Consistent Atomic Deformation Model

    CERN Document Server

    Mehl, M J; Stokes, H T

    1996-01-01

    This is a brief description of how to derive the local ``atomic'' potentials from the Self-Consistent Atomic Deformation (SCAD) model density function. Particular attention is paid to the spherically averaged case.

  8. Development of a Kohn-Sham like potential in the Self-Consistent Atomic Deformation Model

    OpenAIRE

    Mehl, M. J.; Boyer, L. L.; Stokes, H. T.

    1996-01-01

    This is a brief description of how to derive the local ``atomic'' potentials from the Self-Consistent Atomic Deformation (SCAD) model density function. Particular attention is paid to the spherically averaged case.

  9. Homoclinic Chaos in Axisymmetric Bianchi-IX cosmological models with an "ad hoc" quantum potential

    OpenAIRE

    Corrêa, G. C.; Stuchi, T. J.; Jorás, S. E.

    2010-01-01

    In this work we study the dynamics of the axisymmetric Bianchi IX cosmological model with a term of quantum potential added. As it is well known this class of Bianchi IX models are homogeneous and anisotropic with two scale factors, $A(t)$ and $B(t)$, derived from the solution of Einstein's equation for General Relativity. The model we use in this work has a cosmological constant and the matter content is dust. To this model we add a quantum-inspired potential that is intended to represent sh...

  10. Optimizing imaging in suspected appendicitis (OPTIMAP-study: A multicenter diagnostic accuracy study of MRI in patients with suspected acute appendicitis. Study Protocol

    Directory of Open Access Journals (Sweden)

    Bossuyt Patrick MM

    2010-10-01

    Full Text Available Abstract Background In patients with clinically suspected appendicitis, imaging is needed to substantiate the clinical diagnosis. Imaging accuracy of ultrasonography (US is suboptimal, while the most accurate technique (CT is associated with cancer related deaths through exposure to ionizing radiation. MRI is a potential replacement, without associated ionizing radiation and no need for contrast medium administration. If MRI is proven to be sufficiently accurate, it could be introduced in the diagnostic pathway of patients with suspected appendicitis, increasing diagnostic accuracy and improving clinical outcomes, without the risk of radiation induced cancer or iodinated contrast medium-related drawbacks. The multicenter OPTIMAP study was designed to estimate the diagnostic accuracy of MRI in patients with suspected acute appendicitis in the general population. Methods/Design Eligible for this study are consecutive patients presenting with clinically suspected appendicitis at the emergency department in six centers. All patients will undergo imaging according to the Dutch guideline for acute appendicitis: initial ultrasonography in all and subsequent CT whenever US does not confirm acute appendicitis. Then MRI is performed in all patients, but the results are not used for patient management. A final diagnosis assigned by an expert panel, based on all available information including 3-months follow-up, except MRI findings, is used as the reference standard in estimating accuracy. We will calculate the sensitivity, specificity, predictive values and inter-observer agreement of MRI, and aim to include 230 patients. Patient acceptance and total imaging costs will also be evaluated. Discussion If MRI is found to be sufficiently accurate, it could replace CT in some or all patients. This will limit or obviate the ionizing radiation exposure associated risk of cancer induction and contrast medium induced nephropathy with CT, preventing the burden and

  11. Influence of Non-Potential Coronal Magnetic Topology on Solar-Wind Models

    CERN Document Server

    Edwards, S J; Bocquet, F -X; Mackay, D H

    2015-01-01

    By comparing a magneto-frictional model of the low coronal magnetic field to a potential-field source-surface model, we investigate the possible impact of non-potential magnetic structure on empirical solar-wind models. These empirical models (such as Wang-Sheeley-Arge) estimate the distribution of solar-wind speed solely from the magnetic-field structure in the low corona. Our models are computed in a domain between the solar surface and 2.5 solar radii, and are extended to 0.1 AU using a Schatten current-sheet model. The non-potential field has a more complex magnetic skeleton and quasi-separatrix structures than the potential field, leading to different sub-structure in the solar-wind speed proxies. It contains twisted magnetic structures that can perturb the separatrix surfaces traced down from the base of the heliospheric current sheet. A significant difference between the models is the greater amount of open magnetic flux in the non-potential model. Using existing empirical formulae this leads to higher...

  12. Medical History for Prognostic Risk Assessment and Diagnosis of Stable Patients with Suspected Coronary Artery Disease

    Science.gov (United States)

    Min, James K.; Dunning, Allison; Gransar, Heidi; Achenbach, Stephan; Lin, Fay Y.; Al-Mallah, Mouaz; Budoff, Matthew J.; Callister, Tracy Q.; Chang, Hyuk-Jae; Cademartiri, Filippo; Chinnaiyan, Kavitha; Chow, Benjamin J. W.; D’Agostino, Ralph; DeLago, Augustin; Friedman, John; Hadamitzky, Martin; Hausleiter, Joerg; Hayes, Sean; Kaufmann, Philipp; Raff, Gilbert L.; Shaw, Leslee J.; Thomson, Louise; Villines, Todd; Cury, Ricardo C.; Feuchtner, Gudrun; Kim, Yong-Jin; Leipsic, Jonathon; Berman, Daniel S.; Pencina, Michael

    2014-01-01

    Aims To develop a clinical cardiac risk algorithm for stable patients with suspected CAD based upon angina typicality and CAD risk factors. Methods and Results Between 2004 and 2011, 14,004 adults with suspected CAD referred for cardiac imaging were followed: 1) 9,093 patients for CCTA (CCTA-1) followed for 2.0 years; 2) 2,132 patients for CCTA (CCTA-2) followed for 1·6 years, and 3) 2,779 patients for exercise myocardial perfusion scintigraphy followed for 5.0 years. A best-fit model from CCTA-1 for prediction of death or myocardial infarction (MI) was developed, with integer values proportional to regression coefficients. Discrimination was assessed using C-statistic. The validated model was also tested for estimation of the likelihood of obstructive CAD, defined as ≥50% stenosis, as compared to method of Diamond and Forrester (D-F). Primary outcomes included all-cause mortality and non-fatal MI. Secondary outcomes included prevalence of angiographically obstructive CAD. In CCTA-1, best-fit model discriminated individuals at risk of death or MI (C-statistic 0·76). The integer model ranged from 3-13, and corresponded to 3-year death risk or MI of 0·25% to 53·8%. When applied to the CCTA-2 and MPS, the model demonstrated C-statistics of 0·71 and 0·77. Both best-fit (C=0·76, 95% CI 0·746-0·771) and integer model (C=0·71, 95% CI 0·693-0·719) performed better than D-F (C=0·64; 95% CI, 0·628-0·659) for estimating obstructive CAD. Conclusions For stable symptomatic patients with suspected CAD, we developed a history-based method for prediction of death and obstructive CAD. PMID:25865923

  13. Optimisation of the digital radiographic imaging of suspected non-accidental injury

    Science.gov (United States)

    Offiah, Amaka

    of differences in quality of film-screen and digital images. There is much variability in the quality and number of radiographs performed as part of skeletal surveys in the UK for suspected NAI. The Leeds test objects are either not sensitive enough (TO. 10) or perhaps over sensitive (TO. 16) for the purposes of this project. Furthermore, the minimum spatial resolution required for digital imaging in NAI has not been established. Therefore the objective interpretation of phantom studies is difficult. There is scope for reduction of radiation dose to children with no effect on image quality. Diagnostic accuracy (fracture detection) in suspected NAI is generally low, and is not affected by image display modality. Conclusions: The CEC quality criteria are not applicable to the assessment of clinical image quality. A national protocol for skeletal surveys in NAI is required. Dedicated training, close supervision, collaboration and consistent exposure of radiologists to cases of NAI should improve diagnostic accuracy. The potential exists for dose reduction when performing skeletal surveys in children and infants with suspected NAI. Future studies should address this issue.

  14. The potential of electromobility in Austria: An analysis based on hybrid choice models

    OpenAIRE

    Francisco J. Bahamonde-Birke; Hanappi, Tibor

    2015-01-01

    This paper analyses the impact of the introduction of electromobility in Austria, focusing specifically on the potential demand for electric vehicles in the automotive market. We estimate discrete choice behavioral mixture models considering latent variables; these allows us to deal with this potential demand as well as to analyze the effect of different attributes of the alternatives over the potential market penetration. We find out that some usual assumptions regarding electromobilityalso ...

  15. Teachers' reporting of suspected child abuse and neglect: behaviour and determinants.

    Science.gov (United States)

    Goebbels, A F G; Nicholson, J M; Walsh, K; De Vries, H

    2008-12-01

    By reporting suspected child abuse and neglect, teachers can make an important contribution to the early detection and prevention of abuse. However, teachers are sometimes reluctant to report their suspicions. This study investigated the determinants of teachers' reporting behaviour using concepts from the Integrated Change Model. Self-report data were collected from 296 teachers employed in 15 Australian schools. Compared to their colleagues, teachers who had never suspected child abuse or neglect (non-detectors, N=57, 19%) were more likely to have a lower confidence in their skills for recognising the signs of abuse, a higher degree of perceived social support regarding reporting, less years teaching experience and lower academic qualifications. Among those who had suspected cases of child abuse or neglect (N=239, 81%), teachers who always reported their suspicions (consistent reporters, 82%) were more likely to have firm action plans about reporting and detecting signs of CAN than teachers who did not always report their suspicions (inconsistent reporters, 18%). While only a small proportion of the variance in detection and reporting status was explained, the results illustrate the utility of health promotion theory and methods for improving our understanding of these behaviours.

  16. Evaluation and modeling of biochemical methane potential (BMP) of landfilled solid waste: a pilot scale study

    DEFF Research Database (Denmark)

    Bilgili, M Sinan; Demir, Ahmet; Varank, Gamze

    2009-01-01

    The main goal of this study was to present a comparison of landfill performance with respect to solids decomposition. Biochemical methane potential (BMP) test was used to determine the initial and the remaining CH(4) potentials of solid wastes during 27 months of landfilling operation in two pilot...... and R2 reactors were 0.01571 and 0.01195 1/d, respectively. The correlation between the model and the experimental parameters was more than 95%, showing the good fit of the model....

  17. Worm algorithms for the 3-state Potts model with magnetic field and chemical potential

    CERN Document Server

    Delgado, Ydalia; Gattringer, Christof

    2012-01-01

    We discuss worm algorithms for the 3-state Potts model with external field and chemical potential. The complex phase problem of this system can be overcome by using a flux representation where the new degrees of freedom are dimer and monomer variables. Working with this representation we discuss two different generalizations of the conventional Prokof'ev-Svistunov algorithm suitable for Monte Carlo simulations of the model at arbitrary chemical potential and evaluate their performance.

  18. Doubly heavy baryons in a quark model with AdS/QCD inspired potential

    CERN Document Server

    Giannuzzi, Floriana

    2009-01-01

    The spectrum of doubly heavy baryons, hadrons made up of two heavy quarks and one light quark, is computed through a potential model with relativistic kinematics. The expression for the $Q\\bar Q$ potential comes from the AdS/QCD correspondence.

  19. Wildfire potential evaluation during a drought event with a regional climate model and NDVI

    Science.gov (United States)

    Y. Liu; J. Stanturf; S. Goodrick

    2010-01-01

    Regional climate modeling is a technique for simulating high-resolution physical processes in the atmosphere, soil and vegetation. It can be used to evaluate wildfire potential by either providing meteorological conditions for computation of fire indices or predicting soil moisture as a direct measure of fire potential. This study examines these roles using a regional...

  20. EEG generator--a model of potentials in a volume conductor.

    Science.gov (United States)

    Avitan, Lilach; Teicher, Mina; Abeles, Moshe

    2009-11-01

    EEG generator-a model of potentials in a volume conductor. The potential recorded over the cortex electro-corticogram (ECoG) or over the scalp [electroencephalograph (EEG)] derives from the activity of many sources known as "EEG generators." The recorded amplitude is basically a function of the unitary potential of a generator and the statistical relationship between different EEG generators in the recorded population. In this study, we first suggest a new definition of the EEG generator. We use the theory of potentials in a volume conductor and model the contribution of a single synapse activated to the surface potential. We then model the contribution of the generator to the surface potential. Once the generator and its contribution are well defined, we can quantitatively assess the degree of synchronization among generators. The measures obtained by the model for a real life scenario of a group of generators organized in a specific statistical way were consistent with the expected values that were reported experimentally. The study sheds new light on macroscopic modeling approaches which make use of mean soma membrane potential. We showed major contribution of activity of superficial apical synapses to the ECoG signal recorded relative to lower somatic or basal synapses activity.

  1. Determination of morphological, biometric and biochemical susceptibilities in healthy Eurasier dogs with suspected inherited glaucoma.

    Science.gov (United States)

    Boillot, Thomas; Rosolen, Serge G; Dulaurent, Thomas; Goulle, Frédéric; Thomas, Philippe; Isard, Pierre-François; Azoulay, Thierry; Lafarge-Beurlet, Stéphanie; Woods, Mike; Lavillegrand, Sylvie; Ivkovic, Ivana; Neveux, Nathalie; Sahel, José-Alain; Picaud, Serge; Froger, Nicolas

    2014-01-01

    In both humans and dogs, the primary risk factor for glaucoma is high intraocular pressure (IOP), which may be caused by iridocorneal angle (ICA) abnormalities. Oxidative stress has also been implicated in retinal ganglion cell damage associated with glaucoma. A suspected inherited form of glaucoma was recently identified in Eurasier dogs (EDs), a breed for which pedigrees are readily available. Because of difficulties in assessing ICA morphology in dogs with advanced glaucoma, we selected a cohort of apparently healthy dogsfor the investigation of ICA morphological status, IOP and plasma concentrations of oxidative stress biomarkers. We aimed to establish correlations between these factors, to identify predictive markers of glaucoma in this dog breed. A cohort of 28 subjects, volunteered for inclusion by their owners, was selected by veterinary surgeons. These dogs were assigned to four groups: young males, young females (1-3 years old), adult males and adult females (4-8 years old). Ocular examination included ophthalmoscopy, tonometry, gonioscopy, biometry and ultrasound biomicroscopy (UBM), and the evaluation of oxidative stress biomarkers consisting of measurements of plasma glutathione peroxidase (GP) activity and taurine and metabolic precursor (methionine and cysteine) concentrations in plasma. The prevalence of pectinate ligament abnormalities was significantly higher in adult EDs than in young dogs. Moreover, in adult females, high IOP was significantly correlated with a short axial globe length, and a particularly large distance between Schwalbe's line and the anterior lens capsule. GP activity levels were significantly lower in EDs than in a randomized control group of dogs, and plasma taurine concentrations were higher. Hence, ICA abnormalities were associated with weaker antioxidant defenses in EDs, potentially counteracted by higher plasma taurine concentrations. This study suggests that EDs may constitute an appropriate canine model for the

  2. Determination of morphological, biometric and biochemical susceptibilities in healthy Eurasier dogs with suspected inherited glaucoma.

    Directory of Open Access Journals (Sweden)

    Thomas Boillot

    Full Text Available In both humans and dogs, the primary risk factor for glaucoma is high intraocular pressure (IOP, which may be caused by iridocorneal angle (ICA abnormalities. Oxidative stress has also been implicated in retinal ganglion cell damage associated with glaucoma. A suspected inherited form of glaucoma was recently identified in Eurasier dogs (EDs, a breed for which pedigrees are readily available. Because of difficulties in assessing ICA morphology in dogs with advanced glaucoma, we selected a cohort of apparently healthy dogsfor the investigation of ICA morphological status, IOP and plasma concentrations of oxidative stress biomarkers. We aimed to establish correlations between these factors, to identify predictive markers of glaucoma in this dog breed. A cohort of 28 subjects, volunteered for inclusion by their owners, was selected by veterinary surgeons. These dogs were assigned to four groups: young males, young females (1-3 years old, adult males and adult females (4-8 years old. Ocular examination included ophthalmoscopy, tonometry, gonioscopy, biometry and ultrasound biomicroscopy (UBM, and the evaluation of oxidative stress biomarkers consisting of measurements of plasma glutathione peroxidase (GP activity and taurine and metabolic precursor (methionine and cysteine concentrations in plasma. The prevalence of pectinate ligament abnormalities was significantly higher in adult EDs than in young dogs. Moreover, in adult females, high IOP was significantly correlated with a short axial globe length, and a particularly large distance between Schwalbe's line and the anterior lens capsule. GP activity levels were significantly lower in EDs than in a randomized control group of dogs, and plasma taurine concentrations were higher. Hence, ICA abnormalities were associated with weaker antioxidant defenses in EDs, potentially counteracted by higher plasma taurine concentrations. This study suggests that EDs may constitute an appropriate canine model for

  3. Efficient parameterization of cardiac action potential models using a genetic algorithm

    Science.gov (United States)

    Cairns, Darby I.; Fenton, Flavio H.; Cherry, E. M.

    2017-09-01

    Finding appropriate values for parameters in mathematical models of cardiac cells is a challenging task. Here, we show that it is possible to obtain good parameterizations in as little as 30-40 s when as many as 27 parameters are fit simultaneously using a genetic algorithm and two flexible phenomenological models of cardiac action potentials. We demonstrate how our implementation works by considering cases of "model recovery" in which we attempt to find parameter values that match model-derived action potential data from several cycle lengths. We assess performance by evaluating the parameter values obtained, action potentials at fit and non-fit cycle lengths, and bifurcation plots for fidelity to the truth as well as consistency across different runs of the algorithm. We also fit the models to action potentials recorded experimentally using microelectrodes and analyze performance. We find that our implementation can efficiently obtain model parameterizations that are in good agreement with the dynamics exhibited by the underlying systems that are included in the fitting process. However, the parameter values obtained in good parameterizations can exhibit a significant amount of variability, raising issues of parameter identifiability and sensitivity. Along similar lines, we also find that the two models differ in terms of the ease of obtaining parameterizations that reproduce model dynamics accurately, most likely reflecting different levels of parameter identifiability for the two models.

  4. Two loop effective Kähler potential of (non-)renormalizable supersymmetric models

    CERN Document Server

    Nibbelink, S G; Nibbelink, Stefan Groot; Nyawelo, Tino S.

    2006-01-01

    We perform a supergraph computation of the effective Kaehler potential at one and two loops for general four dimensional N=1 supersymmetric theories described by arbitrary Kaehler potential, superpotential and gauge kinetic function. We only insist on gauge invariance of the Kaehler potential and the superpotential as we heavily rely on its consequences in the quantum theory. However, we do not require gauge invariance for the gauge kinetic functions, so that our results can also be applied to anomalous theories that involve the Green-Schwarz mechanism. We illustrate our two loop results by considering a few simple models: the (non-)renormalizable Wess-Zumino model and Super Quantum Electrodynamics.

  5. A case suspected for yellow fever vaccine-associated viscerotropic disease in the Netherlands.

    Science.gov (United States)

    van de Pol, Eva M; Gisolf, Elizabeth H; Richter, Clemens

    2014-01-01

    Yellow fever (YF) 17D vaccine is one of the most successful vaccines ever developed. Since 2001, 56 cases of yellow fever vaccine-associated viscerotropic disease (YEL-AVD) have been published in the peer-reviewed literature. Here, we report a new case suspected for YEL-AVD in the Netherlands. Further research is needed to determine the true incidence of YEL-AVD and to clarify host and vaccine-associated factors in the pathogenesis of YEL-AVD. Because of the potential adverse events, healthcare providers should carefully consider vaccination only in people who are truly at risk for YF infection, especially in primary vaccine recipients.

  6. Cross-sectional study of the prehospital management of adult patients with a suspected seizure (EPIC1)

    Science.gov (United States)

    Taylor, Louise H; Shewan, Jane; Baldwin, Trevor; Grünewald, Richard A; Reuber, Markus

    2016-01-01

    Objectives Suspected seizures are a common reason for emergency calls to ambulance services. Prehospital management of these patients is an important element of good quality care. The aim of this study, conducted in a regional ambulance service in the UK, was to quantify the number of emergency telephone calls for suspected seizures in adults, the associated costs, and to describe the patients’ characteristics, their prehospital management and their immediate outcomes. Design Quantitative cross-sectional study using routinely collected data and a detailed review of the clinical records of a consecutive series of adult patients (≥16 years). Setting A regional ambulance service within the National Health Service in England. Participants Cross-sectional data from all 605 481 adult emergency incidents managed by the ambulance service from 1 April 2012 to 31 March 2013. We selected a consecutive series of 178 individual incidents from May 2012 for more detailed analysis (132 after exclusions and removal of non-seizure cases). Results Suspected seizures made up 3.3% of all emergency incidents. True medical emergencies were uncommon but 3.3% had partially occluded airways, 6.8% had ongoing seizure activity and 59.1% had clinical problems in addition to the seizure (29.1% involving injury). Emergency vehicles were dispatched for 97.2% of suspected seizures, the seizure had terminated on arrival in 93.2% of incidents, 75% of these patients were transported to hospital. The estimated emergency management cost per annum of suspected seizures in the English ambulance services is £45.2 million (€64.0 million, $68.6 million). Conclusions Many patients with suspected seizures could potentially be treated more effectively and at lower cost by modifying ambulance call handling protocols. The development of innovative care pathways could give call handlers and paramedics alternatives to hospital transportation. Increased adoption of care plans could reduce 999 calls and

  7. Forward and inverse problems of electrocardiography: modeling and recovery of epicardial potentials in humans.

    Science.gov (United States)

    Shahidi, A V; Savard, P; Nadeau, R

    1994-03-01

    To assess the accuracy of solutions to the inverse problem of electrocardiography in man, epicardial potentials computed from thoracic potential distributions were compared to potentials measured directly over the surface of the heart during arrhythmia surgery. Three-dimensional finite element models of the thorax with different mesh resolutions and conductivity inhomogeneities were constructed from serial computerized tomography scans of a patient. These torso models were used to compute transfer matrices relating the epicardial potentials to the thoracic potentials. Potential distributions over the torso and the ventricles were measured with 63 leads in the same patient whose anatomical data was used to construct the torso models. To solve the inverse problem, different methods based on Tykhonov regularization or regularization- truncation were applied. The recovered epicardial potential distributions closely resembled the epicardial potential distributions measured early during ventricular preexcitation, but not the more complex distributions measured later during the QRS complex. Several problems encountered as the validation process is applied in man are also discussed.

  8. Chemical Potential of Benzene Fluid from Monte Carlo Simulation with Anisotropic United Atom Model

    Directory of Open Access Journals (Sweden)

    Mahfuzh Huda

    2013-07-01

    Full Text Available The profile of chemical potential of benzene fluid has been investigated using Anisotropic United Atom (AUA model. A Monte Carlo simulation in canonical ensemble was done to obtain the isotherm of benzene fluid, from which the excess part of chemical potential was calculated. A surge of potential energy is observed during the simulation at high temperature which is related to the gas-liquid phase transition. The isotherm profile indicates the tendency of benzene to condensate due to the strong attractive interaction. The results show that the chemical potential of benzene rapidly deviates from its ideal gas counterpart even at low density.

  9. Evaluation of the Component Chemical Potentials in Analytical Models for Ordered Alloy Phases

    Directory of Open Access Journals (Sweden)

    W. A. Oates

    2011-01-01

    Full Text Available The component chemical potentials in models of solution phases with a fixed number of sites can be evaluated easily when the Helmholtz energy is known as an analytical function of composition. In the case of ordered phases, however, the situation is less straightforward, because the Helmholtz energy is a functional involving internal order parameters. Because of this, the chemical potentials are usually obtained numerically from the calculated integral Helmholtz energy. In this paper, we show how the component chemical potentials can be obtained analytically in ordered phases via the use of virtual cluster chemical potentials. Some examples are given which illustrate the simplicity of the method.

  10. Effective Potential of a Two-State Model for Molecular Motor

    Institute of Scientific and Technical Information of China (English)

    HAN Ying-Rong; ZHAO Tong-Jun; ZHAN-Yong; YAN Wei-Li

    2005-01-01

    We study force generation and motion of molecular motors using a simple two-state model in the paper.Asymmetric and periodic potential is adopted to describe the interaction between motor proteins and filaments that are periodic and polar. The current and the slope of the effective potential as functions of the temperature and transition rates are calculated in the two-state model. The ratio of the slope of the effective potential to the current is also calculated. It is shown that the directed motion of motor proteins is relevant to the effective potential. The slope of the effective potential corresponds to an average force. The non-vanishing force therefore implies that detailed balance is broken in the process of transition between different states.

  11. Modeling the local potential at Pt nanoparticles in polymer electrolyte membranes.

    Science.gov (United States)

    Eslamibidgoli, Mohammad Javad; Melchy, Pierre-Éric Alix; Eikerling, Michael H

    2015-04-21

    We present a physical-analytical model for the potential distribution at Pt nanodeposits in a polymer electrolyte membrane (PEM). Experimental studies have shown that solid deposits of Pt in PEM play a dual role in radical-initiated membrane degradation. Surface reactions at Pt particles could facilitate the formation as well as the scavenging of ionomer-attacking radical species. The net radical balance depends on local equilibrium conditions at Pt nanodeposits in the PEM, specifically, their equivalent local electrode potential. Our approach utilizes a continuum description of crossover fluxes of reactant gases, coupled with the kinetics of electrochemical surface reactions at Pt nanodeposits to calculate the potential distribution. The local potential is a function of the PEM structure and composition, which is determined by PEM thickness, concentrations of H2 and O2, as well as the size and density distribution of Pt particles. Model results compare well with experimental data for the potential distribution in PEMs.

  12. Gurson-type elastic-plastic damage model based on strain-rate plastic potential

    Science.gov (United States)

    Balan, Tudor; Cazacu, Oana

    2013-12-01

    Ductile damage is generally described by stress-space analytical potentials. In this contribution, it is shown that strain rate potentials, which are exact conjugate of the stress-based potentials, can be equally used to describe the dilatational response of porous metals. This framework is particularly appropriate for porous materials with matrix described by complex yield criteria for which a closed-form expression of the stress-based potential is not available. Illustration of the new approach is done for porous metals containing randomly distributed spherical voids in a von Mises elasto-plastic matrix. Furthermore, a general time integration algorithm for simulation of the mechanical response using this new formulation is developed and implemented in Abaqus/Standard. The proposed model and algorithm are validated with respect to the Abaqus built-in GTN model, which is based on a stress potential, through the simulation of a tensile test on a round bar.

  13. Macrobenthos habitat potential mapping using GIS-based artificial neural network models.

    Science.gov (United States)

    Lee, Saro; Park, Inhye; Koo, Bon Joo; Ryu, Joo-Hyung; Choi, Jong-Kuk; Woo, Han Jun

    2013-02-15

    This paper proposes and tests a method of producing macrobenthos habitat potential maps in Hwangdo tidal flat, Korea based on an artificial neural network. Samples of macrobenthos were collected during field work, and eight control factors were compiled as a spatial database from remotely sensed data and GIS analysis. The macrobenthos habitat potential maps were produced using an artificial neural network model. Macrobenthos habitat potential maps were made for Macrophthalmus dilatatus, Cerithideopsilla cingulata, and Armandia lanceolata. The maps were validated by compared with the surveyed habitat locations. A strong correlation between the potential maps and species locations was revealed. The validation result showed average accuracies of 74.9%, 78.32%, and 73.27% for M. dilatatus, C. cingulata, and A. lanceolata, respectively. A GIS-based artificial neural network model combined with remote sensing techniques is an effective tool for mapping the areas of macrobenthos habitat potential in tidal flats.

  14. A review of animal models used to evaluate potential allergenicity of genetically modified organisms (GMOs)

    DEFF Research Database (Denmark)

    Marsteller, Nathan; Bøgh, Katrine Lindholm; Goodman, Richard E.

    2017-01-01

    Food safety regulators request prediction of allergenicity for newly expressed proteins in genetically modified (GM) crops and in novel foods. Some have suggested using animal models to assess potential allergenicity. A variety of animal models have been used in research to evaluate sensitisation...... of genetically modified organisms (GMOs)....

  15. Biases in judging victims and suspects whose statements are inconsistent.

    Science.gov (United States)

    Malloy, Lindsay C; Lamb, Michael E

    2010-02-01

    In this commentary, we point to similarities in characteristics of suspect and victim/witness statements and the underlying motivations of these individuals. Despite the similarities, there are differences in how such statements are evaluated by fact-finders and investigators. Retractions, for example, cast serious doubt on the credibility of victims/witnesses but appear not to diminish the power of confessions. Investigators need to recognize the wide range of motivations behind statements made to the authorities and be mindful of biased dispositions to doubt victims and believe confessors, especially when their statements are inconsistent or retracted. An investigative process that was entirely transparent would help ensure that inconsistencies and retractions, whether in statements from victims, witnesses, or suspects, are viewed in the context of other statements and eliciting circumstances.

  16. Suspected side effects to the quadrivalent human papilloma vaccine

    DEFF Research Database (Denmark)

    Brinth, Louise; Theibel, Ann Cathrine; Pors, Kirsten

    2015-01-01

    INTRODUCTION: The quadrivalent vaccine that protects against human papilloma virus types 6, 11, 16 and 18 (Q-HPV vaccine, Gardasil) was included into the Danish childhood vaccination programme in 2009. During the past years, a collection of symptoms primarily consistent with sympathetic nervous...... system dysfunction have been described as suspected side effects to the Q-HPV vaccine. METHODS: We present a description of suspected side effects to the Q-HPV vaccine in 53 patients referred to our Syncope Unit for tilt table test and evaluation of autonomic nervous system function. RESULTS: All...... consistency in the reported symptoms as well as between our findings and those described by others. Our findings neither confirm nor dismiss a causal link to the Q-HPV vaccine, but they suggest that further research is urgently warranted to clarify the pathophysiology behind the symptoms experienced...

  17. Suspected side effects to the quadrivalent human papilloma vaccine

    DEFF Research Database (Denmark)

    Brinth, Louise; Theibel, Ann Cathrine; Pors, Kirsten;

    2015-01-01

    system dysfunction have been described as suspected side effects to the Q-HPV vaccine. METHODS: We present a description of suspected side effects to the Q-HPV vaccine in 53 patients referred to our Syncope Unit for tilt table test and evaluation of autonomic nervous system function. RESULTS: All......INTRODUCTION: The quadrivalent vaccine that protects against human papilloma virus types 6, 11, 16 and 18 (Q-HPV vaccine, Gardasil) was included into the Danish childhood vaccination programme in 2009. During the past years, a collection of symptoms primarily consistent with sympathetic nervous...... consistency in the reported symptoms as well as between our findings and those described by others. Our findings neither confirm nor dismiss a causal link to the Q-HPV vaccine, but they suggest that further research is urgently warranted to clarify the pathophysiology behind the symptoms experienced...

  18. High rate of benign histology in radiologically suspect renal lesions

    DEFF Research Database (Denmark)

    Lindkvist Pedersen, Christina; Winck-Flyvholm, Lili; Dahl, Claus;

    2014-01-01

    or radical nephrectomy between November 2010 and July 2013. All patients underwent a multiphase helical computed tomography (CT), which revealed suspected renal malignancy. The exclusion criteria were cystic tumours, biopsy before surgery, and disseminated and locally advanced disease. Lesions were defined......INTRODUCTION: The objective of this study was to determine the incidence of benign renal lesions for clinically localised renal masses and the need for new diagnostic procedures to assess these lesions. MATERIAL AND METHODS: This retrospective study included patients who underwent partial.......4% of patients with intermediate tumours, p renal masses ≤ 4 cm even though CT revealed a suspect renal lesion. The need for new diagnostic approaches for clinically localised renal lesions is evident. FUNDING: not relevant. TRIAL REGISTRATION...

  19. MRI for clinically suspected pediatric appendicitis: an implemented program

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Michael M.; Gustas, Cristy N.; Choudhary, Arabinda K.; Methratta, Sosamma T.; Hulse, Michael A.; Eggli, Kathleen D.; Boal, Danielle K.B. [Penn State Milton S. Hershey Medical Center, Department of Radiology, Mail Code H066, 500 University Drive, P.O. Box 850, Hershey, PA (United States); Geeting, Glenn [Penn State Milton S. Hershey Medical Center, Department of Emergency Medicine, Hershey, PA (United States)

    2012-09-15

    Emergent MRI is now a viable alternative to CT for evaluating appendicitis while avoiding the detrimental effects of ionizing radiation. However, primary employment of MRI in the setting of clinically suspected pediatric appendicitis has remained significantly underutilized. To describe our institution's development and the results of a fully implemented clinical program using MRI as the primary imaging evaluation for children with suspected appendicitis. A four-sequence MRI protocol consisting of coronal and axial single-shot turbo spin-echo (SS-TSE) T2, coronal spectral adiabatic inversion recovery (SPAIR), and axial SS-TSE T2 with fat saturation was performed on 208 children, ages 3 to 17 years, with clinically suspected appendicitis. No intravenous or oral contrast material was administered. No sedation was administered. Data collection includes two separate areas: time parameter analysis and MRI diagnostic results. Diagnostic accuracy of MRI for pediatric appendicitis indicated a sensitivity of 97.6% (CI: 87.1-99.9%), specificity 97.0% (CI: 93.2-99.0%), positive predictive value 88.9% (CI: 76.0-96.3%), and negative predictive value 99.4% (CI: 96.6-99.9%). Time parameter analysis indicated clinical feasibility, with time requested to first sequence obtained mean of 78.7 +/- 52.5 min, median 65 min; first-to-last sequence time stamp mean 14.2 +/- 8.8 min, median 12 min; last sequence to report mean 57.4 +/- 35.2 min, median 46 min. Mean age was 11.2 +/- 3.6 years old. Girls represented 57% of patients. MRI is an effective and efficient method of imaging children with clinically suspected appendicitis. Using an expedited four-sequence protocol, sensitivity and specificity are comparable to CT while avoiding the detrimental effects of ionizing radiation. (orig.)

  20. Optimal Diagnostic Approaches for Patients with Suspected Small Bowel Disease

    Science.gov (United States)

    Kim, Jae Hyun; Moon, Won

    2016-01-01

    While the domain of gastrointestinal endoscopy has made great strides over the last several decades, endoscopic assessment of the small bowel continues to be challenging. Recently, with the development of new technology including video capsule endoscopy, device-assisted enteroscopy, and computed tomography/magnetic resonance enterography, a more thorough investigation of the small bowel is possible. In this article, we review the systematic approach for patients with suspected small bowel disease based on these advanced endoscopic and imaging systems. PMID:27334413

  1. Rhodococcus equi isolation from sputum of patients with suspected tuberculosis

    Directory of Open Access Journals (Sweden)

    Paulo da Silva

    2010-03-01

    Full Text Available Rhodococcus equi has emerged as an opportunistic pathogen associated with pulmonary, invasive or systemic infections in immunocompromised patients. We report the identification of 51 R. equi isolates found in sputum samples of 546 individuals suspected to have pulmonary tuberculosis in two Public Health Hospital Units in Brazil. The epidemiology of R. equi infection as well as the phenotypic identification and drug susceptibility profile of isolates are described in this paper.

  2. Interviewing strategically to elicit admissions from guilty suspects

    OpenAIRE

    Tekin, Serra; Granhag, Pär Anders; Strömwall, Leif; Giolla, Erik Mac; Vrij, Aldert; Hartwig, Maria

    2015-01-01

    In this article we introduce a novel interviewing tactic to elicit admissions from guilty suspects. By influencing the suspects’ perception of the amount of evidence the interviewer holds against them, we aimed to shift the suspects’ counterinterrogation strategies from less to more forthcoming. The proposed tactic (SUE-Confrontation) is a development of the Strategic Use of Evidence (SUE) framework and aims to affect the suspects’ perception by confronting them with statement-evidence incons...

  3. MRI for clinically suspected pediatric appendicitis: case interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Michael M.; Brian, James M.; Methratta, Sosamma T.; Hulse, Michael A.; Choudhary, Arabinda K.; Eggli, Kathleen D.; Boal, Danielle K.B. [Penn State Milton S. Hershey Medical Center, Division of Pediatric Radiology, Department of Radiology, Hershey, PA (United States)

    2014-05-15

    As utilization of MRI for clinically suspected pediatric appendicitis becomes more common, there will be increased focus on case interpretation. The purpose of this pictorial essay is to share our institution's case interpretation experience. MRI findings of appendicitis include appendicoliths, tip appendicitis, intraluminal fluid-debris level, pitfalls of size measurements, and complications including abscesses. The normal appendix and inguinal appendix are also discussed. (orig.)

  4. Potential transformation of trace species including aircraft exhaust in a cloud environment. The `Chedrom model`

    Energy Technology Data Exchange (ETDEWEB)

    Ozolin, Y.E.; Karol, I.L. [Main Geophysical Observatory, St. Petersburg (Russian Federation); Ramaroson, R. [Office National d`Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France)

    1997-12-31

    Box model for coupled gaseous and aqueous phases is used for sensitivity study of potential transformation of trace gases in a cloud environment. The rate of this transformation decreases with decreasing of pH in droplets, with decreasing of photodissociation rates inside the cloud and with increasing of the droplet size. Model calculations show the potential formation of H{sub 2}O{sub 2} in aqueous phase and transformation of gaseous HNO{sub 3} into NO{sub x} in a cloud. This model is applied for exploration of aircraft exhausts evolution in plume inside a cloud. (author) 10 refs.

  5. Isgur–Wise function in a QCD-inspired potential model with WKB approximation

    Indian Academy of Sciences (India)

    BHASKAR JYOTI HAZARIKA; D K CHOUDHURY

    2017-03-01

    We use Wentzel–Kramers–Brillouin (WKB) approximation for calculating the slope and curvature of Isgur–Wise function in a QCD-inspired potential model. This work is an extension of the approximation methods to the QCD-inspired potential model. The approach hints at an effective range of distance for calculating the slope and curvature of Isgur–Wise function. Comparison is also made with those of Dalgarno method and variationallyimproved perturbation theory (VIPT) as well as other models to show the advantages of using WKB approximation.

  6. Isgur-Wise function in a QCD-inspired potential model with WKB approximation

    Science.gov (United States)

    Hazarika, Bhaskar Jyoti; Choudhury, D. K.

    2017-03-01

    We use Wentzel-Kramers-Brillouin (WKB) approximation for calculating the slope and curvature of Isgur-Wise function in a QCD-inspired potential model. This work is an extension of the approximation methods to the QCD-inspired potential model. The approach hints at an effective range of distance for calculating the slope and curvature of Isgur-Wise function. Comparison is also made with those of Dalgarno method and variationally improved perturbation theory (VIPT) as well as other models to show the advantages of using WKB approximation.

  7. Form Factors and charge radii of heavy flavored mesons in a potential model

    CERN Document Server

    Das, T; Bordoloi, N S

    2016-01-01

    We report the results for charge radii of heavy flavored mesons ($D^+, D^0, D^+_s, B^+, B^0, B^0_s$) in a QCD model with the potential $V(r)=-4\\frac{\\alpha_s}{3r}+br+c$ by incorporating two scales $r^{short}$ and $r^{long}$ as an integration limit so that the perturbative procedure can be improved in a potential model. We also obtain the analytical expressions for Form Factors in terms of momentum transfer ($Q^2$). The obtained results are compared with our earlier works and with the other theoretical models.

  8. The Approximative Hamiltonian for the Dicce model defined in term one-zone potential

    CERN Document Server

    Rasulova, M Yu

    2002-01-01

    The Approximative Hamiltonian (AHM) for the Dicce model is defined in terms of the one-zone potential. We investigate the Dicce model on the base of Petrins-Belokolos's method. This method offers the following advantages. It makes it possible to simplify the construction of the self-consistent equation and the structure of approximative Hamiltonians. In addition, the AHM allows the exact solution of the self-consistent equation to be found and, thus, the approximative Hamiltonian for the Dicce model to be defined in terms of one-zone potential.

  9. Radiative contribution to the effective potential in a composite Higgs model

    CERN Document Server

    DeGrand, T A; Jay, W I; Neil, E T; Shamir, Y; Svetitsky, B

    2016-01-01

    The SU(4) gauge theory with two flavors of Dirac fermions in the sextet representation shares features of a candidate for a composite Higgs model. The analogue of the Higgs multiplet of the Standard Model lives in the Goldstone manifold resulting from spontaneous breaking of the global symmetry SU(4) to SO(4). The Higgs potential arises from interaction with the particles of the Standard Model. We have computed the gauge boson contribution to the Higgs potential, using valence overlap fermions on a Wilson-clover sea. The calculation is similar to that of the electromagnetic mass splitting of the pion multiplet in QCD.

  10. The combination of satellite and topographic/isostatic potential models for mean anomaly determinations

    Science.gov (United States)

    Rapp, Richard H.; Pavlis, Nikolaos

    A method is presented for the estimation of a global gravity anomaly field using the combination of satellite-derived potential coefficient models and the coefficients implied by the Airy-Heiskanen topographic/isostatic potential (Rummel et al., 1988) from topographic models with a 30-km depth of compensation. Gravity anomalies calculated with this method are compared with a terrestrial 1 x 1 degree anomaly file where the anomaly standard deviations were less than 10 mgals. Using the GEM T1 model (Marsh et al., 1988) to degree 36, the rms anomaly discrepency was + or - 19 mgals, while the rms values for the terrestrial anomalies was + or - 28 mgals.

  11. Pharmacodynamic Modelling of Placebo and Buprenorphine Effects on Event-Related Potentials in Experimental Pain

    DEFF Research Database (Denmark)

    Juul, Rasmus V; Foster, David J R; Upton, Richard N

    2014-01-01

    The purpose of the study was to investigate placebo and buprenorphine effects on event-related potentials (ERPs) in experimental pain and the potential benefit of population pharmacodynamic modelling in data analysis. Nineteen healthy volunteers received transdermal placebo and buprenorphine...... in a cross-over study. Drug plasma concentrations and ERPs after electrical stimulation at the median nerve with intensity adjusted to pain detection threshold were recorded until 144 hrs after administration. Placebo and concentration-effect models were fitted to data using non-linear mixed......-effects modelling implemented in NONMEM (V7.2.0.). Pharmacodynamic models were developed to adequately describe both placebo and buprenorphine ERP data. Models predicted significant placebo effects, but did not predict significant effects related to buprenorphine concentration. Models revealed that ERPs varied both...

  12. Modeling extracellular field potentials and the frequency-filtering properties of extracellular space

    CERN Document Server

    Bedard, C; Destexhe, A; Bédard, Claude; Kroeger, Helmut; Destexhe, Alain

    2003-01-01

    Extracellular local field potentials (LFP) are usually modeled as arising from a set of current sources embedded in a homogeneous extracellular medium. Although this formalism can successfully model several properties of LFPs, it does not account for their frequency-dependent attenuation with distance, a property essential to correctly model extracellular spikes. Here we derive expressions for the extracellular potential that include this frequency-dependent attenuation. We first show that, if the extracellular conductivity is non-homogeneous, there is induction of non-homogeneous charge densities which may result in a low-pass filter. We next derive a simplified model consisting of a punctual (or spherical) current source with spherically-symmetric conductivity/permittivity gradients around the source. We analyze the effect of different radial profiles of conductivity and permittivity on the frequency-filtering behavior of this model. We show that this simple model generally displays low-pass filtering behav...

  13. Adsorption of metal atoms at a buckled graphene grain boundary using model potentials

    Energy Technology Data Exchange (ETDEWEB)

    Helgee, Edit E.; Isacsson, Andreas [Department of Applied Physics, Chalmers University of Technology, SE-412 96, Göteborg (Sweden)

    2016-01-15

    Two model potentials have been evaluated with regard to their ability to model adsorption of single metal atoms on a buckled graphene grain boundary. One of the potentials is a Lennard-Jones potential parametrized for gold and carbon, while the other is a bond-order potential parametrized for the interaction between carbon and platinum. Metals are expected to adsorb more strongly to grain boundaries than to pristine graphene due to their enhanced adsorption at point defects resembling those that constitute the grain boundary. Of the two potentials considered here, only the bond-order potential reproduces this behavior and predicts the energy of the adsorbate to be about 0.8 eV lower at the grain boundary than on pristine graphene. The Lennard-Jones potential predicts no significant difference in energy between adsorbates at the boundary and on pristine graphene. These results indicate that the Lennard-Jones potential is not suitable for studies of metal adsorption on defects in graphene, and that bond-order potentials are preferable.

  14. Characterization and identification of suspected counterfeit miltefosine capsules.

    Science.gov (United States)

    Dorlo, Thomas P C; Eggelte, Teunis A; de Vries, Peter J; Beijnen, Jos H

    2012-03-07

    Recently, it was revealed that generic miltefosine capsules for the treatment of visceral leishmaniasis, a fatal parasitic disease, were possibly counterfeit products. Here we report on the methods to characterize and identify miltefosine in pharmaceutical products and the procedures that were used to assess the quality of these suspected counterfeit products. Characterization and identification of miltefosine were done with liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), Fourier transform infrared (FT-IR) spectroscopy and near-infrared (NIR) spectroscopy. Moreover, a simple, rapid and inexpensive colorimetric test was developed and evaluated for the detection of miltefosine in pharmaceutical products that can be used in the field. The complementary analytical techniques presented here were able to determine qualitatively or (semi-)quantitatively the presence or absence of miltefosine in pharmaceutical preparations and could identify suspected counterfeit miltefosine capsules. This finding of a suspected counterfeit drug intended to treat a neglected disease in a resource-poor country emphasizes the urgent need to develop more simple inexpensive assays to evaluate drug quality for use in the field.

  15. Role of intravenous immunoglobulin in suspected or proven neonatal sepsis

    Institute of Scientific and Technical Information of China (English)

    GAUTAM M. K.; JIANG Li

    2013-01-01

    Neonatal sepsis remains the major cause of mortality and morbidity including neurodevelopmental impairment and prolonged hospital stay in newborn infants .Despite of advances in technology and optimal antibiotic tre-atment, incidence of neonatal sepsis and its complications remains unacceptably high especially in developing countries .Premature neonates in particular are at higher risk due to developmentally immature host defence mecha-nisms.Though not approved by Food and Drug Administration ( FDA ) U.S.A, off label use of intravenous immunoglobulin as prophylactic or adjuvant agent in suspected or proven neonatal infections continues in many countries.In a recent large multicenter clinical trial by International Neonatal Immunotherapy Study (INIS) group, the use of polyvalent IgG immune globulin was not associated with significant differences in the risk of major com -plications or other adverse outcomes in neonates with suspected or proven sepsis .Hence, use of intravenous immu-noglobulin in suspected or proven neonatal sepsis is not recommended .The expense of prophylactic use of intrave-nous immunoglobulin administration for both term and preterm newborn population , given the minimal benefit as demonstrated by many individual studies and by meta-analysis is not justified .

  16. MR delayed enhancement imaging findings in suspected acute myocarditis

    Energy Technology Data Exchange (ETDEWEB)

    Gahide, Gerald [CHU de Montpellier, Radiologie centrale - Pole Cardiovasculaire et Thoracique, Montpellier (France); Centre Hospitalo-Universitaire de Montpellier, Hopital A de Villeneuve, Montpellier (France); Bertrand, D.; Dacher, J.N. [CHU de Rouen, Radiologie centrale - Hopital Charles Nicolle, Rouen (France); Roubille, F.; Skaik, S.; Piot, C.; Leclerq, F. [CHU de Montpellier, Departement de Cardiologie - Pole Cardiovasculaire et Thoracique, Montpellier (France); Tron, C.; Cribier, A. [CHU de Rouen, Departement de Cardiologie - Hopital Charles Nicolle, Rouen (France); Vernhet, H. [CHU de Montpellier, Radiologie centrale - Pole Cardiovasculaire et Thoracique, Montpellier (France)

    2010-01-15

    The purpose of the study was to prospectively assess the clinical impact of routinely performed delayed enhancement imaging in suspected acute myocarditis. A two-centre prospective study was performed in patients with suspected acute myocarditis. The protocol included horizontal long axis, vertical long axis and short axis cine MR and delayed enhancement imaging after Gd-DTPA infusion (0.2 mmol/kg). Sixty consecutive patients were enrolled (aged 49.4{+-}17.8 years). MRI demonstrated delayed enhancement sparing the subendocardicardial layer in 51.6% of patients, concordant with the diagnosis of acute myocarditis; 16.7% of patients exhibited delayed enhancement involving the subendocardial layer with irregular margins, concordant with the diagnosis of acute myocardial infarction; 31.7% of patients had delayed enhancement imaging that was considered normal. Routine imaging to identify delayed enhancement provided crucial information in suspected acute myocarditis by reinforcing the diagnosis in 51.6% of patients and correcting a misdiagnosed acute myocardial infarction in 16.7% of patients. (orig.)

  17. The economics of cardiac biomarker testing in suspected myocardial infarction.

    Science.gov (United States)

    Goodacre, Steve; Thokala, Praveen

    2015-03-01

    Suspected myocardial infarction (MI) is a common reason for emergency hospital attendance and admission. Cardiac biomarker measurement is an essential element of diagnostic assessment of suspected MI. Although the cost of a routinely available biomarker may be small, the large patient population and consequences in terms of hospital admission and investigation mean that the economic impact of cardiac biomarker testing is substantial. Economic evaluation involves comparing the estimated costs and effectiveness (outcomes) of two or more interventions or care alternatives. This process creates some difficulties with respect to cardiac biomarkers. Estimating the effectiveness of cardiac biomarkers involves identifying how they help to improve health and how we can measure this improvement. Comparison to an appropriate alternative is also problematic. New biomarkers may be promoted on the basis of reducing hospital admission or length of stay, but hospital admission for low risk patients may incur significant costs while providing very little benefit, making it an inappropriate comparator. Finally, economic evaluation may conclude that a more sensitive biomarker strategy is more effective but, by detecting and treating more cases, is also more expensive. In these circumstances it is unclear whether we should use the more effective or the cheaper option. This article provides an introduction to health economics and addresses the specific issues relevant to cardiac biomarkers. It describes the key concepts relevant to economic evaluation of cardiac biomarkers in suspected MI and highlights key areas of uncertainty and controversy.

  18. A machine learning approach to the potential-field method for implicit modeling of geological structures

    Science.gov (United States)

    Gonçalves, Ítalo Gomes; Kumaira, Sissa; Guadagnin, Felipe

    2017-06-01

    Implicit modeling has experienced a rise in popularity over the last decade due to its advantages in terms of speed and reproducibility in comparison with manual digitization of geological structures. The potential-field method consists in interpolating a scalar function that indicates to which side of a geological boundary a given point belongs to, based on cokriging of point data and structural orientations. This work proposes a vector potential-field solution from a machine learning perspective, recasting the problem as multi-class classification, which alleviates some of the original method's assumptions. The potentials related to each geological class are interpreted in a compositional data framework. Variogram modeling is avoided through the use of maximum likelihood to train the model, and an uncertainty measure is introduced. The methodology was applied to the modeling of a sample dataset provided with the software Move™. The calculations were implemented in the R language and 3D visualizations were prepared with the rgl package.

  19. Ecological Niche Modeling of Potential West Nile Virus Vector Mosquito Species in Iowa

    OpenAIRE

    2010-01-01

    Ecological niche modeling (ENM) algorithms, Maximum Entropy Species Distribution Modeling (Maxent) and Genetic Algorithm for Rule-set Prediction (GARP), were used to develop models in Iowa for three species of mosquito — two significant, extant West Nile virus (WNV) vectors (Culex pipiens L and Culex tarsalis Coquillett (Diptera: Culicidae)), and the nuisance mosquito, Aedes vexans Meigen (Diptera: Culicidae), a potential WNV bridge vector. Occurrence data for the three mosquito species from ...

  20. Potential Improvement of Building Information Modeling (BIM) Implementation in Malaysian Construction Projects

    OpenAIRE

    Latiffi, Aryani,; Mohd, Suzila; Rakiman, Umol,

    2015-01-01

    Part 4: Building Information Modeling (BIM); International audience; Application of building information modeling (BIM), such as preview design clashes and visualize project’s model increase effectiveness in managing construction projects. However, its implementation in Malaysian construction projects is slow in order to see and gain the benefits. Therefore, this paper aims to explore on potential improvement that could increase BIM implementation in construction projects. A literature review...

  1. Modeling the Potential for Vaccination to Diminish the Burden of Invasive Non-typhoidal Salmonella Disease in Young Children in Mali, West Africa

    Science.gov (United States)

    Bornstein, Kristin; Hungerford, Laura; Hartley, David; Sorkin, John D.; Tapia, Milagritos D.; Sow, Samba O.; Onwuchekwa, Uma; Simon, Raphael; Tennant, Sharon M.

    2017-01-01

    Background In sub-Saharan Africa, systematic surveillance of young children with suspected invasive bacterial disease (e.g., septicemia, meningitis) has revealed non-typhoidal Salmonella (NTS) to be a major pathogen exhibiting high case fatality (~20%). Where infant vaccination against Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae has been introduced to prevent invasive disease caused by these pathogens, as in Bamako, Mali, their burden has decreased markedly. In parallel, NTS has become the predominant invasive bacterial pathogen in children aged vaccines to prevent invasive NTS (iNTS) disease. We developed a mathematical model to estimate the potential impact of NTS vaccination programs in Bamako. Methodology/Principal Findings A Markov chain transmission model was developed utilizing age-specific Bamako demographic data and hospital surveillance data for iNTS disease in children aged vaccine coverage and efficacy similar to the existing, successfully implemented, Hib vaccine. Annual iNTS hospitalizations and deaths in children vaccine, were the model’s outcomes of interest. Per the model, high coverage/high efficacy iNTS vaccination programs would drastically diminish iNTS disease except among infants age vaccination shifts as disease burden, vaccine coverage, and serovar distribution vary. Our model shows that implementing an iNTS vaccine through an analogous strategy to the Hib vaccination program in Bamako would markedly reduce cases and deaths due to iNTS among the pediatric population. The model can be adjusted for use elsewhere in Africa where NTS epidemiologic patterns, serovar prevalence, and immunization schedules differ from Bamako. PMID:28182657

  2. Robust global identifiability theory using potentials--Application to compartmental models.

    Science.gov (United States)

    Wongvanich, N; Hann, C E; Sirisena, H R

    2015-04-01

    This paper presents a global practical identifiability theory for analyzing and identifying linear and nonlinear compartmental models. The compartmental system is prolonged onto the potential jet space to formulate a set of input-output equations that are integrals in terms of the measured data, which allows for robust identification of parameters without requiring any simulation of the model differential equations. Two classes of linear and non-linear compartmental models are considered. The theory is first applied to analyze the linear nitrous oxide (N2O) uptake model. The fitting accuracy of the identified models from differential jet space and potential jet space identifiability theories is compared with a realistic noise level of 3% which is derived from sensor noise data in the literature. The potential jet space approach gave a match that was well within the coefficient of variation. The differential jet space formulation was unstable and not suitable for parameter identification. The proposed theory is then applied to a nonlinear immunological model for mastitis in cows. In addition, the model formulation is extended to include an iterative method which allows initial conditions to be accurately identified. With up to 10% noise, the potential jet space theory predicts the normalized population concentration infected with pathogens, to within 9% of the true curve. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Modelling Soil Water Retention for Weed Seed Germination Sensitivity to Water Potential

    Directory of Open Access Journals (Sweden)

    W. John Bullied

    2012-01-01

    Full Text Available Soil water retention is important for the study of water availability to germinating weed seeds. Six soil water retention models (Campbell, Brooks-Corey, four- and five-parameter van Genuchten, Tani, and Russo with residual soil water parameter derivations were evaluated to describe water retention for weed seed germination at minimum threshold soil water potential for three hillslope positions. The Campbell, Brooks-Corey, and four-parameter van Genuchten model with modified or estimated forms of the residual parameter had superior but similar data fit. The Campbell model underestimated water retention at a potential less than −0.5 MPa for the upper hillslope that could result in underestimating seed germination. The Tani and Russo models overestimated water retention at a potential less than −0.1 MPa for all hillslope positions. Model selection and residual parameter specification are important for weed seed germination by representing water retention at the level of minimum threshold water potential for germination. Weed seed germination models driven by the hydrothermal soil environment rely on the best-fitting soil water retention model to produce dynamic predictions of seed germination.

  4. The effect of empirical potential functions on modeling of amorphous carbon using molecular dynamics method

    Energy Technology Data Exchange (ETDEWEB)

    Li, Longqiu, E-mail: longqiuli@gmail.com [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001 (China); Xu, Ming; Song, Wenping [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001 (China); Ovcharenko, Andrey [Western Digital Corporation, San Jose, CA (United States); Zhang, Guangyu; Jia, Ding [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001 (China)

    2013-12-01

    Empirical potentials have a strong effect on the hybridization and structure of amorphous carbon and are of great importance in molecular dynamics (MD) simulations. In this work, amorphous carbon at densities ranging from 2.0 to 3.2 g/cm{sup 3} was modeled by a liquid quenching method using Tersoff, 2nd REBO, and ReaxFF empirical potentials. The hybridization, structure and radial distribution function G(r) of carbon atoms were analyzed as a function of the three potentials mentioned above. The ReaxFF potential is capable to model the change of the structure of amorphous carbon and MD results are in a good agreement with experimental results and density function theory (DFT) at low density of 2.6 g/cm{sup 3} and below. The 2nd REBO potential can be used when amorphous carbon has a very low density of 2.4 g/cm{sup 3} and below. Considering the computational efficiency, the Tersoff potential is recommended to model amorphous carbon at a high density of 2.6 g/cm{sup 3} and above. In addition, the influence of the quenching time on the hybridization content obtained with the three potentials is discussed.

  5. πN Elastic Scattering and Resonances in Quark Potential Model

    Institute of Scientific and Technical Information of China (English)

    CHEN Ju-Mei; WANG Hai-Jun; LI Cheng-Zu; SU Jun-Chen; LIANG Lin-Mei; CHEN Ping-Xing; DAI Hong-Yi

    2008-01-01

    The quark potential model is used to investigate the low-energy elastic scattering of π N system. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the harmonic oscillator confining potential. By means of the resonating group method, a nonlocal effective potential for the πN system is derived from the interquark potentials and used to calculate the π N elastic scattering phase shifts. By considering the effect of QCD renormalization, the suppression of the spin-orbital coupling and the contribution of the color octet of the clusters (qq) and (qqq), the numerical results are in fairly good agreement with the experimental data. The same model and method are employed to investigate the possible πN resonances. For this purpose, the resonating group equation is transformed into a standard Schrodinger equation in which the nonlocal effective πN interaction potential is included. Solving the Schrodinger equation by the variational method, we are able to reproduce the masses of some currently concerned πN resonances.

  6. A revised study of the Li2+ alkali-dimer using a model potential approach

    Science.gov (United States)

    Rabli, Djamal; McCarroll, Ronald

    2017-04-01

    The model potential approach is well adapted to study atomic and molecular systems involving a single active electron. Such is the case of the alkali-dimer lithium cation Li2+ . However, a comparison of the model potential results of Magnier et al. (1999) and those based on ab initio techniques (Bouzouita et al., 2006; Jasik et al., 2007, Musial et al., 2015) raises a number of questions related to the existence of an important disagreement regarding several excited states,which are found to be repulsive by Magnier et al. (1999) but attractive when ab initio techniques are employed. In this paper, we propose to re-investigate the Li2+ system, using a model potential technique to compute the adiabatic energy curves and the molecular spectroscopic constants. Our aim is to clarify whether this disagreement between the ab initio and model potential methods originates from some conceptual defect of the model potential technique or whether there is some source of error in the calculations of Magnier et al. (1999).

  7. Modeling and mapping potential distribution of Crimean juniper (Juniperus excelsa Bieb.) using correlative approaches.

    Science.gov (United States)

    Özkan, Kürşad; Şentürk, Özdemir; Mert, Ahmet; Negiz, Mehmet Güvenç

    2015-01-01

    Modeling and mapping potential distribution of living organisms has become an important component of conservation planning and ecosystem management in recent years. Various correlative and mechanistic methods can be applied to build predictive distributions of living organisms in terrestrial and marine ecosystems. Correlative methods used to predict species' potential distribution have been described as either group discrimination techniques or profile techniques. We attempted to determine whether group discrimination techniques could perform as well as profile techniques for predicting species potential distributions, using elevation (ELVN), parent material (ROCK), slope (SLOP), radiation index (RI) and topographic position index (TPI)) as explanatory variables. We compared potential distribution predictions made for Crimean juniper (Juniperus excelsa Bieb.) in the Yukan Gokdere forest district of the Mediterranean region, Turkey, applying four group discrimination techniques (discriminate analysis (DA), logistic regression analysis (LR), generalized addictive model (GAM) and classification tree technique (CT)) and two profile techniques (a maximum entropy approach to species distribution modeling (MAXENT), the genetic algorithm for rule-set prediction (GARP)). Visual assessments of the potential distribution probability of the applied models for Crimean juniper were performed by using geographical information systems (GIS). Receiver-operating characteristic (ROC) curves were used to objectively assess model performance. The results suggested that group discrimination techniques are better than profile techniques and, among the group discrimination techniques, GAM indicated the best performance.

  8. Myosin phosphorylation and force potentiation in skeletal muscle: evidence from animal models.

    Science.gov (United States)

    Vandenboom, Rene; Gittings, William; Smith, Ian C; Grange, Robert W; Stull, James T

    2013-12-01

    The contractile performance of mammalian fast twitch skeletal muscle is history dependent. The effect of previous or ongoing contractile activity to potentiate force, i.e. increase isometric twitch force, is a fundamental property of fast skeletal muscle. The precise manifestation of force potentiation is dependent upon a variety of factors with two general types being identified; staircase potentiation referring to the progressive increase in isometric twitch force observed during low frequency stimulation while posttetanic potentiation refers to the step-like increase in isometric twitch force observed following a brief higher frequency (i.e. tetanic) stimulation. Classic studies established that the magnitude and duration of potentiation depends on a number of factors including muscle fiber type, species, temperature, sarcomere length and stimulation paradigm. In addition to isometric twitch force, more recent work has shown that potentiation also influences dynamic (i.e. concentric and/or isotonic) force, work and power at a range of stimulus frequencies in situ or in vitro, an effect that may translate to enhanced physiological function in vivo. Early studies performed on both intact and permeabilized models established that the primary mechanism for this modulation of performance was phosphorylation of myosin, a modification that increased the Ca(2+) sensitivity of contraction. More recent work from a variety of muscle models indicates, however, the presence of a secondary mechanism for potentiation that may involve altered Ca(2+) handling. The primary purpose of this review is to highlight these recent findings relative to the physiological utility of force potentiation in vivo.

  9. Calculation of energy spectrum of $^{12}$C isotope with modified Yukawa potential by cluster models

    Indian Academy of Sciences (India)

    MOHAMMAD REZA SHOJAE; NAFISEH ROSHAN BAKHT

    2016-10-01

    In this paper, we have calculated the energy spectrum of 12C isotope in two-cluster models, $3\\alpha$ cluster model and $^8$Be + $\\alpha$ cluster model. We use the modified Yukawa potential for interaction between theclusters and solve the Schrödinger equation using Nikiforov–Uvarov method to calculate the energy spectrum. Then, we increase the accuracy by adding spin-orbit coupling and tensor force and solve them by perturbationtheory in both models. Finally, the calculated results for both models are compared with each other and with the experimental data. The results show that the isotope $^{12}$C should be considered as a three-$\\alpha$ cluster and themodified Yukawa potential is adaptable for cluster interactions.

  10. Forest models: their development and potential applications for air pollution effects research

    Energy Technology Data Exchange (ETDEWEB)

    Shugart, H.H.; McLaughlin, S.B.; West, D.C.

    1980-01-01

    As research tools for evaluating the effects of chronic air pollution stress, forest simulation models offer one means of integrating forest growth and development data with generalized indices of pollution stress. This approach permits consideration of both the competitive interactions of trees in the forest stand and the influences of the stage of stand development on sensitivity of component species. A review of forest growth models, including tree, stand, and gap models, is provided as a means of evaluating relative strengths, weaknesses, and limits of applicability of representative examples of each type. Data from recent simulations with a gap model of eastern deciduous forest responses to air pollution stress are presented to emphasize the potential importance of competition in modifying individual species' responses in a forest stand. Recent developments in dendroecology are discussed as a potential mechanism for model validation and extended application.

  11. A continuum model of piezoelectric potential generated in a bent ZnO nanorod

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Z Z; Wen, L Y; Wu, D M [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215125 (China); Wang, X F; Zhang, X A; Chang, S L, E-mail: zzshao2009@gmail.co [Center of Materials Science, College of Science, National University of Defense Technology, Changsha 410073 (China)

    2010-06-23

    A continuum model of piezoelectric potential generated in a bent ZnO nanorod cantilever is presented by means of the first piezoelectric effect approximation. The analytical solution of the model shows that the piezoelectric potential in the nanorod is proportional to the lateral force but is independent along the longitudinal direction. The electric potential in the tensile area and that in the compressive area are antisymmetric in the cross section of the nanorod, which makes the nanorod a 'parallel plate capacitor' for piezoelectric nanodevices, such as a nanogenerator. The magnitude of piezoelectric potential for a ZnO nanorod of 50 nm diameter and 600 nm length bent by a 80 nN lateral force is about 0.27 V, which is in good agreement with the finite element method calculation.

  12. Hyperon Single-Particle Potentials Calculated from SU6 Quark-Model Baryon-Baryon Interactions

    CERN Document Server

    Kohno, M; Fujita, T; Nakamoto, C; Suzuki, Y

    2000-01-01

    Using the SU6 quark-model baryon-baryon interaction recently developed by the Kyoto-Niigata group, we calculate NN, Lambda N and Sigma N G-matrices in ordinary nuclear matter. This is the first attempt to discuss the Lambda and Sigma single-particle potentials in nuclear medium, based on the realistic quark-model potential. The Lambda potential has the depth of more than 40 MeV, which is more attractive than the value expected from the experimental data of Lambda-hypernuclei. The Sigma potential turns out to be repulsive, the origin of which is traced back to the strong Pauli repulsion in the Sigma N (I=3/2) ^3S_1 state.

  13. Probing deconfinement in a chiral effective model with Polyakov loop at imaginary chemical potential

    CERN Document Server

    Morita, Kenji; Friman, Bengt; Redlich, Krzysztof

    2011-01-01

    The phase structure of the two-flavor Polyakov-loop extended Nambu-Jona-Lashinio model is explored at finite temperature and imaginary chemical potential with a particular emphasis on the confinement-deconfinement transition. We point out that the confined phase is characterized by a $\\cos3\\mu_I/T$ dependence of the chiral condensate on the imaginary chemical potential while in the deconfined phase this dependence is given by $\\cos\\mu_I/T$ and accompanied by a cusp structure induced by the Z(3) transition. We demonstrate that the phase structure of the model strongly depends on the choice of the Polyakov loop potential $\\mathcal{U}$. Furthermore, we find that by changing the four fermion coupling constant $G_s$, the location of the critical endpoint of the deconfinement transition can be moved into the real chemical potential region. We propose a new parameter characterizing the confinement-deconfinement transition.

  14. Analytical modeling of threshold voltage for Cylindrical Gate All Around (CGAA MOSFET using center potential

    Directory of Open Access Journals (Sweden)

    K.P. Pradhan

    2015-12-01

    Full Text Available In this paper, an analytical threshold voltage model is proposed for a cylindrical gate-all-around (CGAA MOSFET by solving the 2-D Poisson’s equation in the cylindrical coordinate system. A comparison is made for both the center and the surface potential model of CGAA MOSFET. This paper claims that the calculation of threshold voltage using center potential is more accurate rather than the calculation from surface potential. The effects of the device parameters like the drain bias (VDS, oxide thickness (tox, channel thickness (r, etc., on the threshold voltage are also studied in this paper. The model is verified with 3D numerical device simulator Sentaurus from Synopsys Inc.

  15. A 1-D modelling of streaming potential dependence on water content during drainage experiment in sand

    CERN Document Server

    Allègre, Vincent; Ackerer, Philippe; Jouniaux, Laurence; Sailhac, Pascal; 10.1111/j.1365-246X.2012.05371.x

    2012-01-01

    The understanding of electrokinetics for unsaturated conditions is crucial for numerous of geophysical data interpretation. Nevertheless, the behaviour of the streaming potential coefficient C as a function of the water saturation Sw is still discussed. We propose here to model both the Richards' equation for hydrodynamics and the Poisson's equation for electrical potential for unsaturated conditions using 1-D finite element method. The equations are first presented and the numerical scheme is then detailed for the Poisson's equation. Then, computed streaming potentials (SPs) are compared to recently published SP measurements carried out during drainage experiment in a sand column. We show that the apparent measurement of DV / DP for the dipoles can provide the SP coefficient in these conditions. Two tests have been performed using existing models for the SP coefficient and a third one using a new relation. The results show that existing models of unsaturated SP coefficients C(Sw) provide poor results in term...

  16. Quasi-3D modeling of surface potential and threshold voltage of Triple Metal Quadruple Gate MOSFETs

    Science.gov (United States)

    Gupta, Santosh Kumar; Shah, Mihir Kumar P.

    2017-01-01

    In this paper we present electrostatic model of 3D Triple Metal Quadruple Gate (TMQG) MOSFET of rectangular cross-section based on quasi-3D method. The analytical equations for channel potential and characteristic length have been derived by decomposing TMQG into two 2D perpendicular cross-sections (triple metal double gate, TMDG) and the effective characteristic length of TMQG is found using equivalent number of gates (ENG) method. For each of the TMDG, 2D Poisson's equation is solved by parabolic approximation and proper boundary conditions to calculate channel potential. The threshold voltage expression is developed using inversion carrier charge sheet density method. The developed models for channel potential and threshold voltage are validated using numerical simulations of TMQG. The developed model provides the design guidelines for TMQG with improved HCEs and SCEs.

  17. Structure of Kaehler potential for D-term inflationary attractor models

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Kazunori [Tokyo Univ. (Japan). Dept. of Physics; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; Saikawa, Ken' ichi [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Tokyo Institute of Technology (Japan). Dept. of Physics; Terada, Takahiro [Tokyo Univ. (Japan). Dept. of Physics; Asia Pacific Center for Theoretical Physics (APCTP), Pohang (Korea, Republic of); Yamaguchi, Masahide [Tokyo Institute of Technology (Japan). Dept. of Physics

    2016-05-15

    Minimal chaotic models of D-term inflation predicts too large primordial tensor perturbations. Although it can be made consistent with observations utilizing higher order terms in the Kaehler potential, expansion is not controlled in the absence of symmetries. We comprehensively study the conditions of Kaehler potential for D-term plateau-type potentials and discuss its symmetry. They include the α-attractor model with a massive vector supermultiplet and its generalization leading to pole inflation of arbitrary order. We extend the models so that it can describe Coulomb phase, gauge anomaly is cancelled, and fields other than inflaton are stabilized during inflation. We also point out a generic issue for large-field D-term inflation that the masses of the non-inflaton fields tend to exceed the Planck scale.

  18. Interparticle potential energy for D-dimensional electromagnetic models from the corresponding scalar ones

    CERN Document Server

    Accioly, Antonio; Correia, Gilson; Brito, Gustavo; de Almeida, José; Herdy, Wallace

    2016-01-01

    Using a method based on the generating functional plus a kind of "correspondence principle" --- which acts as a bridge between the electromagnetic and scalar fields --- it is shown that the interparticle potential energy concerning a given $D$-dimensional electromagnetic model can be obtained in a simple way from that related to the corresponding scalar system. The $D$-dimensional electromagnetic potential for a general model containing higher derivatives is then found from the corresponding scalar one and the behavior of the former is analyzed at large as well as small distances. In addition, we investigate the presence of ghosts in the four-dimensional version of the potential associated with the model above and analyze the reason why the Coulomb singularity is absent from this system. The no-go theorem by Ostrogradski is demystified as well.

  19. Self-Diffusion Coefficients in Liquid Ag Using the Embedded Atom Model Based Effective Pair Potentials

    OpenAIRE

    DALGIÇ, Seyfettin; ÇOLAKOĞULLARI, Mutlu

    2006-01-01

    We present the dynamical properties of liquid Ag at different temperatures, using the Mishin and Doyoma-Kagure version of the Embedded Atom Model (EAM) potentials. They have been evaluated within the framework of the mode-coupling theory, using a self-consistent scheme that uses as input data only the static structure functions and the interatomic pair potentials of the liquid Ag. We have computed single-particle and collective time dependent properties of liquid Ag, and thereby calc...

  20. Supersolid Phase in One-Dimensional Hard-Core Boson Hubbard Model with a Superlattice Potential

    Institute of Scientific and Technical Information of China (English)

    GUO Huai-Ming; LIANG Ying

    2008-01-01

    The ground state of the one-dimensional hard-core boson Hubbard model with a superlattice potential is studied by quantum Monte Carlo methods. We demonstrate that besides the CDW phase and the Mort insulator phase, the supersolid phase emerges due to the presence of the superlattice potential, which reflects the competition with the hopping term. We also study the densities of sublattices and have a clear idea about the distribution of the bosons on the lattice.

  1. Cochlear Delay and Medial Olivocochlear Functioning in Children with Suspected Auditory Processing Disorder.

    Directory of Open Access Journals (Sweden)

    Sriram Boothalingam

    Full Text Available Behavioral manifestations of processing deficits associated with auditory processing disorder (APD have been well documented. However, little is known about their anatomical underpinnings, especially cochlear processing. Cochlear delays, a proxy for cochlear tuning, measured using stimulus frequency otoacoustic emission (SFOAE group delay, and the influence of the medial olivocochlear (MOC system activation at the auditory periphery was studied in 23 children suspected with APD (sAPD and 22 typically developing (TD children. Results suggest that children suspected with APD have longer SFOAE group delays (possibly due to sharper cochlear tuning and reduced MOC function compared to TD children. Other differences between the groups include correlation between MOC function and SFOAE delay in quiet in the TD group, and lack thereof in the sAPD group. MOC-mediated changes in SFOAE delay were in opposite directions between groups: increase in delay in TD vs. reduction in delay in the sAPD group. Longer SFOAE group delays in the sAPD group may lead to longer cochlear filter ringing, and potential increase in forward masking. These results indicate differences in cochlear and MOC function between sAPD and TD groups. Further studies are warranted to explore the possibility of cochlea as a potential site for processing deficits in APD.

  2. On modelling of physical effects accompanying the propagation of action potentials in nerve fibres

    CERN Document Server

    Engelbrecht, Jüri; Tamm, Kert; Laasmaa, Martin; Vendelin, Marko

    2016-01-01

    The recent theoretical and experimental studies have revealed many details of signal propagation in nervous systems. In this paper an attempt is made to unify various mathematical models which describe the signal propagation in nerve fibres. The analysis of existing single models permits to select the leading physiological effects. As a result, a more general mathematical model is described based on the coupling of action potentials with mechanical waves in a nerve fibre. The crucial issue is how to model coupling effects which are strongly linked to the ion currents through biomembranes.

  3. Anatomic distribution of embolus at CT pulmonary angiography in patients suspected acute pulmonary embolism

    Institute of Scientific and Technical Information of China (English)

    朱力

    2013-01-01

    Objective To summarize and analyze the morphology and distribution of embolus in patients suspected acute pulmonary embolism. Methods The CT pulmonary angiography(CTPA) imagings of 279 patients suspected acute pulmonary embolism were analyzed retrospectively in

  4. Reconstruction of the Scalar Field Potential in Inflationary Models with a Gauss-Bonnet term

    CERN Document Server

    Koh, Seoktae; Tumurtushaa, Gansukh

    2016-01-01

    We study inflationary models with a Gauss-Bonnet term to reconstruct the scalar field potentials and the Gauss-Bonnet coupling functions from the observable quantities. Using the observationally favored relations for both $n_s$ and $r$, we derive the expressions for both the scalar field potentials and the coupling functions. The implication of the blue-tilted spectrum, $n_t>0$, of the primordial tensor fluctuations is discussed for the reconstructed configurations of the scalar field potential and the Gauss-Bonnet coupling.

  5. The Effective Kahler Potential, Metastable Vacua and R-Symmetry Breaking in O'Raifeartaigh Models

    CERN Document Server

    Benjamin, Shermane; Kain, Ben

    2010-01-01

    Much has been learned about metastable vacua and R-symmetry breaking in O'Raifeartaigh models. Such work has largely been done from the perspective of the superpotential and by including Coleman-Weinberg corrections to the scalar potential. Instead, we consider these ideas from the perspective of the one loop effective Kahler potential. We translate known ideas to this framework and construct convenient formulas for computing individual terms in the expanded effective Kahler potential. We do so for arbitrary R-charge assignments and allow for small R-symmetry violating terms so that both spontaneous and explicit R-symmetry breaking is allowed in our analysis.

  6. Extension of the coherence function to quadratic models. [applied to plasma density and potential fluctuations

    Science.gov (United States)

    Kim, Y. C.; Wong, W. F.; Powers, E. J.; Roth, J. R.

    1979-01-01

    It is shown how the use of higher coherence functions can recover some of the lost coherence due to nonlinear relationship between two fluctuating quantities whose degree of mutual coherence is being measured. The relationship between the two processes is modeled with the aid of a linear term and a quadratic term. As a specific example, the relationship between plasma density and potential fluctuations in a plasma is considered. The fraction of power in the auto-power spectrum of the potential fluctuations due to a linear relationship and to a quadratic relationship between the density and potential fluctuations is estimated.

  7. An examination of the hypothesis that intraocular pressure elevation episodes can have prognostic significance in glaucoma suspects.

    Science.gov (United States)

    McMonnies, Charles

    2015-01-01

    The efficacy of intraocular pressure reduction in retarding the progression of glaucoma has been demonstrated. This review examines the potential for prognostic advantage for glaucoma suspects in reducing their optic nerve head exposure to elevated intraocular pressure associated with activities which have been shown to elevate intraocular pressure. In this observational study, patients examined at the Centre for Eye Health (University of New South Wales) with a diagnosis of glaucoma suspect were surveyed to determine their histories for participation in activities which are known to elevate intraocular pressure. The evidence regarding the pathological significance of these sources of elevation in susceptible patients was examined. Apart from the universality of sleep-related intraocular pressure elevations, the histories from 183 confirmed glaucoma suspects indicate a wide range and variation in frequency of participation in other intraocular pressure elevating activities. A reduction in exposure to elevated intraocular pressure may improve the prognosis for glaucoma suspects. Additional patient specific assessment of the results of this screening could provide an indication of the degree (frequency, intensity level and duration) of exposure to elevated intraocular pressure. Such information may provide the basis for improving a patient's prognosis by helping them to identify opportunities to reduce such exposure to elevated intraocular pressure. Any benefit of reduction of such exposure appears likely to be greater if activities which elevate intraocular pressure are of long duration, occur frequently, occur over a long period of time, and/or involve high levels of intraocular pressure elevation.

  8. Modelling highly variable environmental factors to assess potential microbial respiration in complex floodplain landscapes

    Science.gov (United States)

    Tritthart, Michael; Welti, Nina; Bondar-Kunze, Elisabeth; Pinay, Gilles; Hein, Thomas; Habersack, Helmut

    2011-01-01

    The hydrological exchange conditions strongly determine the biogeochemical dynamics in river systems. More specifically, the connectivity of surface waters between main channels and floodplains is directly controlling the delivery of organic matter and nutrients into the floodplains, where biogeochemical processes recycle them with high rates of activity. Hence, an in-depth understanding of the connectivity patterns between main channel and floodplains is important for the modelling of potential gas emissions in floodplain landscapes. A modelling framework that combines steady-state hydrodynamic simulations with long-term discharge hydrographs was developed to calculate water depths as well as statistical probabilities and event durations for every node of a computation mesh being connected to the main river. The modelling framework was applied to two study sites in the floodplains of the Austrian Danube River, East of Vienna. Validation of modelled flood events showed good agreement with gauge readings. Together with measured sediment properties, results of the validated connectivity model were used as basis for a predictive model yielding patterns of potential microbial respiration based on the best fit between characteristics of a number of sampling sites and the corresponding modelled parameters. Hot spots of potential microbial respiration were found in areas of lower connectivity if connected during higher discharges and areas of high water depths. PMID:27667961

  9. Neutron penetrabilities using an optical model potential (1963); Penetrabilites des neutrons selon le modele du potentiel optique (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Mani, G.S.; Melkanoff, M.A.; Iori, I. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    The neutron penetrabilities and reaction cross-sections are presented in these tables for the case of an optical model potential for the nucleus, for nuclei up to mass 230. (authors) [French] Les penetrabilites et les sections efficaces de reaction pour les neutrons sont donnees dans ces tables en utilisant le modele du potentiel optique, pour les noyaux cibles jusqu'a la masse 230. (auteurs)

  10. Two center shell model with Woods-Saxon potentials: adiabatic and diabatic states in fusion

    CERN Document Server

    Díaz-Torres, A; Diaz-Torres, Alexis; Scheid, Werner

    2005-01-01

    A realistic two-center shell model for fusion is proposed, which is based on two spherical Woods-Saxon potentials and the potential separable expansion method. This model describes the single-particle motion in a fusing system. A technique for calculating stationary diabatic states is suggested which makes use of the formal definition of those states, i.e., they minimize the radial nonadiabatic coupling between the adiabatic states. As an example the system $^{16}$O + $^{40}$Ca $\\to$ $^{56}$Ni is discussed.

  11. The Decay $\\eta_c \\rightarrow \\gamma \\gamma$ : A Test for Potential Models

    OpenAIRE

    Ahmady, M. R.; Mendel, R. R.

    1994-01-01

    We use a simple perturbation theory argument and measurements of charmonium leptonic widths $\\Gamma (\\psi_{NS} \\rightarrow e^+e^-)$ to estimate the ratio \\mbox{$R_\\circ \\equiv {\\vert \\Psi _{\\eta_{c1S}}(0) \\vert}^2 /{\\vert\\Psi_{\\psi_{1 S}}(0)\\vert}^2$} in the general context of non- relativistic potential models. We obtain $R_\\circ = 1.4 \\pm 0.1$. We then apply well known potential model formulas, which include lowest order QCD corrections, to find $\\Gamma (\\eta_c \\rightarrow \\gamma \\gamma )/\\...

  12. Strange quark polarization of the nucleon: a parameter-independent prediction of the chiral potential model.

    Science.gov (United States)

    Chen, X B; Chen, X S; Wang, F

    2001-07-02

    We perform a one-loop calculation of the strange quark polarization (Deltas) of the nucleon in an SU(3) chiral potential model. We find that if the intermediate quark excited states are summed over in a proper way, i.e., summed up to a given energy instead of given radial and orbital quantum numbers, Deltas turns out to be almost independent of all the model parameters: quark masses and potential strengths. The contribution from the quark-antiquark pair creation and annihilation " Z" diagrams is found to be significant. Our numerical results agree quite reasonably with experiments and lattice QCD calculations.

  13. A method for physically based model analysis of conjunctive use in response to potential climate changes

    Science.gov (United States)

    Hanson, R.T.; Flint, L.E.; Flint, A.L.; Dettinger, M.D.; Faunt, C.C.; Cayan, D.; Schmid, W.

    2012-01-01

    Potential climate change effects on aspects of conjunctive management of water resources can be evaluated by linking climate models with fully integrated groundwater-surface water models. The objective of this study is to develop a modeling system that links global climate models with regional hydrologic models, using the California Central Valley as a case study. The new method is a supply and demand modeling framework that can be used to simulate and analyze potential climate change and conjunctive use. Supply-constrained and demand-driven linkages in the water system in the Central Valley are represented with the linked climate models, precipitation-runoff models, agricultural and native vegetation water use, and hydrologic flow models to demonstrate the feasibility of this method. Simulated precipitation and temperature were used from the GFDL-A2 climate change scenario through the 21st century to drive a regional water balance mountain hydrologic watershed model (MHWM) for the surrounding watersheds in combination with a regional integrated hydrologic model of the Central Valley (CVHM). Application of this method demonstrates the potential transition from predominantly surface water to groundwater supply for agriculture with secondary effects that may limit this transition of conjunctive use. The particular scenario considered includes intermittent climatic droughts in the first half of the 21st century followed by severe persistent droughts in the second half of the 21st century. These climatic droughts do not yield a valley-wide operational drought but do cause reduced surface water deliveries and increased groundwater abstractions that may cause additional land subsidence, reduced water for riparian habitat, or changes in flows at the Sacramento-San Joaquin River Delta. The method developed here can be used to explore conjunctive use adaptation options and hydrologic risk assessments in regional hydrologic systems throughout the world.

  14. Summer cooling potential of urban vegetation—a modeling study for Melbourne, Australia

    Directory of Open Access Journals (Sweden)

    Dong Chen

    2015-06-01

    Full Text Available The summer cooling potential of urban vegetation is investigated using an urban climate model for the current and future climates in the Melbourne central business district (CBD area with various urban forms and vegetation schemes. Simulation results suggest that the average seasonal summer temperatures can be reduced in the range of around 0.5 and 2°C if the Melbourne CBD were replaced by vegetated suburbs and planted parklands, respectively, benefiting a reduction in the number of hot days. It was also found that despite the projected warming in the future and variations in the climate projections among different climate models, the average seasonal cooling potential due to various urban vegetation schemes may not change significantly in comparison with those predicted for the current climate, indicating little dependency on climate change. This finding suggests that the average seasonal cooling potential as a result of urban vegetation in future climates may be empirically quantified in similar amounts to those under the current climate. When urban climate models are used, the cooling potential of urban vegetation in future climates may be quantified by modeling several selected years with one or a few climate models.

  15. Parameter estimation in neuronal stochastic differential equation models from intracellular recordings of membrane potentials in single neurons

    DEFF Research Database (Denmark)

    Ditlevsen, Susanne; Samson, Adeline

    2016-01-01

    evolution. One-dimensional models are the stochastic integrate-and-fire neuronal diffusion models. Biophysical neuronal models take into account the dynamics of ion channels or synaptic activity, leading to multidimensional diffusion models. Since only the membrane potential can be measured......Dynamics of the membrane potential in a single neuron can be studied by estimating biophysical parameters from intracellular recordings. Diffusion processes, given as continuous solutions to stochastic differential equations, are widely applied as models for the neuronal membrane potential...

  16. Random forest-based protein model quality assessment (RFMQA) using structural features and potential energy terms.

    Science.gov (United States)

    Manavalan, Balachandran; Lee, Juyong; Lee, Jooyoung

    2014-01-01

    Recently, predicting proteins three-dimensional (3D) structure from its sequence information has made a significant progress due to the advances in computational techniques and the growth of experimental structures. However, selecting good models from a structural model pool is an important and challenging task in protein structure prediction. In this study, we present the first application of random forest based model quality assessment (RFMQA) to rank protein models using its structural features and knowledge-based potential energy terms. The method predicts a relative score of a model by using its secondary structure, solvent accessibility and knowledge-based potential energy terms. We trained and tested the RFMQA method on CASP8 and CASP9 targets using 5-fold cross-validation. The correlation coefficient between the TM-score of the model selected by RFMQA (TMRF) and the best server model (TMbest) is 0.945. We benchmarked our method on recent CASP10 targets by using CASP8 and 9 server models as a training set. The correlation coefficient and average difference between TMRF and TMbest over 95 CASP10 targets are 0.984 and 0.0385, respectively. The test results show that our method works better in selecting top models when compared with other top performing methods. RFMQA is available for download from http://lee.kias.re.kr/RFMQA/RFMQA_eval.tar.gz.

  17. Numerical verification of similar Cam-clay model based on generalized potential theory

    Institute of Scientific and Technical Information of China (English)

    钟志辉; 杨光华; 傅旭东; 温勇; 张玉成

    2014-01-01

    From the mathematical principles, the generalized potential theory can be employed to create constitutive model of geomaterial directly. The similar Cam-clay model, which is created based on the generalized potential theory, has less assumptions, clearer mathematical basis, and better computational accuracy. Theoretically, it is more scientific than the traditional Cam-clay models. The particle flow code PFC3D was used to make numerical tests to verify the rationality and practicality of the similar Cam-clay model. The verification process was as follows: 1) creating the soil sample for numerical test in PFC3D, and then simulating the conventional triaxial compression test, isotropic compression test, and isotropic unloading test by PFC3D; 2) determining the parameters of the similar Cam-clay model from the results of above tests; 3) predicting the sample’s behavior in triaxial tests under different stress paths by the similar Cam-clay model, and comparing the predicting results with predictions by the Cam-clay model and the modified Cam-clay model. The analysis results show that the similar Cam-clay model has relatively high prediction accuracy, as well as good practical value.

  18. Quintessence models with an oscillating equation of state and their potentials

    Institute of Scientific and Technical Information of China (English)

    Zhao Wen

    2007-01-01

    In this paper, we investigate the quintessence models with an oscillating equation of state (EOS) and its potentials.From the constructed potentials, which have an EOS of ωφ = ω0 + ω1 sin z, we find that they are all the oscillating functions of the field φ, and the oscillating amplitudes decrease (or increase) with φ. From the evolutive equation of the field φ, we find that this is caused by the expansion of the universe. This also makes it very difficult to build a model whose EOS oscillates forever. However one can build a model with EOS oscillating for a certain period of time. Then we discuss three quintessence models, which are the combinations of the invert power law functions and the oscillating functions of the field φ. We find that they all follow the oscillating EOS.

  19. Static Potential in the SU(2)-Higgs Model and Coupling Constant Definitions in Lattice and Continuum Models

    CERN Document Server

    Csikor, Ferenc; Hegedüs, P; Piróth, A

    1999-01-01

    We present a one-loop calculation of the static potential in the SU(2)-Higgs model. The connection to the coupling constant definition used in lattice simulations is clarified. The consequences in comparing lattice simulations and perturbative results for finite temperature applications are explored.

  20. Reverse engineering model structures for soil and ecosystem respiration: the potential of gene expression programming

    Science.gov (United States)

    Ilie, Iulia; Dittrich, Peter; Carvalhais, Nuno; Jung, Martin; Heinemeyer, Andreas; Migliavacca, Mirco; Morison, James I. L.; Sippel, Sebastian; Subke, Jens-Arne; Wilkinson, Matthew; Mahecha, Miguel D.

    2017-09-01

    Accurate model representation of land-atmosphere carbon fluxes is essential for climate projections. However, the exact responses of carbon cycle processes to climatic drivers often remain uncertain. Presently, knowledge derived from experiments, complemented by a steadily evolving body of mechanistic theory, provides the main basis for developing such models. The strongly increasing availability of measurements may facilitate new ways of identifying suitable model structures using machine learning. Here, we explore the potential of gene expression programming (GEP) to derive relevant model formulations based solely on the signals present in data by automatically applying various mathematical transformations to potential predictors and repeatedly evolving the resulting model structures. In contrast to most other machine learning regression techniques, the GEP approach generates readable models that allow for prediction and possibly for interpretation. Our study is based on two cases: artificially generated data and real observations. Simulations based on artificial data show that GEP is successful in identifying prescribed functions, with the prediction capacity of the models comparable to four state-of-the-art machine learning methods (random forests, support vector machines, artificial neural networks, and kernel ridge regressions). Based on real observations we explore the responses of the different components of terrestrial respiration at an oak forest in south-eastern England. We find that the GEP-retrieved models are often better in prediction than some established respiration models. Based on their structures, we find previously unconsidered exponential dependencies of respiration on seasonal ecosystem carbon assimilation and water dynamics. We noticed that the GEP models are only partly portable across respiration components, the identification of a general terrestrial respiration model possibly prevented by equifinality issues. Overall, GEP is a promising

  1. How Should Journal Editors Respond to Cases of Suspected Misconduct?

    Directory of Open Access Journals (Sweden)

    Elizabeth Wager

    2014-10-01

    Full Text Available Journals and institutions have important complementary roles to play in cases of suspected research and publication misconduct. Journals should take responsibility for everything they publish and should alert institutions to cases of possible serious misconduct but should not attempt to investigate such cases. Institutions should take responsibility for their researchers and for investigating cases of possible misconduct and for ensuring journals are informed if they have published unreliable or misleading articles so that these can be retracted or corrected. Journals and institutions should have policies in place for handling such cases and these policies should respect their different roles.

  2. How should journal editors respond to cases of suspected misconduct?

    Science.gov (United States)

    Wager, Elizabeth

    2014-01-01

    Journals and institutions have important complementary roles to play in cases of suspected research and publication misconduct. Journals should take responsibility for everything they publish and should alert institutions to cases of possible serious misconduct but should not attempt to investigate such cases. Institutions should take responsibility for their researchers and for investigating cases of possible misconduct and for ensuring journals are informed if they have published unreliable or misleading articles so that these can be retracted or corrected. Journals and institutions should have policies in place for handling such cases and these policies should respect their different roles.

  3. Infant with cardiomyopathy: When to suspect inborn errors of metabolism?

    Institute of Scientific and Technical Information of China (English)

    Stephanie; L; Byers; Can; Ficicioglu

    2014-01-01

    Inborn errors of metabolism are identified in 5%-26% of infants and children with cardiomyopathy. Although fatty acid oxidation disorders, lysosomal and glycogen storage disorders and organic acidurias are well-known to be associated with cardiomyopathies, emerging reports suggest that mitochondrial dysfunction and congenital disorders of glycosylation may also account for a proportion of cardiomyopathies. This review article clarifies when primary care physicians and cardiologists should suspect inborn errors of metabolism in a patient with cardiomyopathy, and refer the patient to a metabolic specialist for a further metabolic work up, with specific discussions of “red flags” which should prompt additional evaluation.

  4. 9 CFR 354.123 - Segregation of suspects on ante-mortem inspection.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Segregation of suspects on ante-mortem... Inspection Procedures; Ante-Mortem Inspections § 354.123 Segregation of suspects on ante-mortem inspection. All rabbits which, on ante-mortem inspection, do not plainly show, but are suspected of being...

  5. Quantification of soil organic carbon sequestration potential in cropland:A model approach

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Agroecosystems have a critical role in the terrestrial carbon cycling process.Soil organic carbon(SOC) in cropland is of great importance for mitigating atmospheric carbon dioxide increases and for global food security.With an understanding of soil carbon saturation,we analyzed the datasets from 95 global long-term agricultural experiments distributed across a vast area spanning wide ranges of temperate,subtropical and tropical climates.We then developed a statistical model for estimating SOC sequestration potential in cropland.The model is driven by air temperature,precipitation,soil clay content and pH,and explains 58% of the variation in the observed soil carbon saturation(n=76).Model validation using independent data observed in China yielded a correlation coefficient R2 of 0.74(n=19,P<0.001).Model sensitivity analysis suggested that soils with high clay content and low pH in the cold,humid regions possess a larger carbon sequestration potential than other soils.As a case study,we estimated the SOC sequestration potential by applying the model in Henan Province.Model estimations suggested that carbon(C) density at the saturation state would reach an average of 32 t C ha-1 in the top 0-20 cm soil depth.Using SOC density in the 1990s as a reference,cropland soils in Henan Province are expected to sequester an additional 100 Tg C in the future.

  6. Stable topological modes in two-dimensional Ginzburg-Landau models with trapping potentials

    CERN Document Server

    Mihalache, D; Skarka, V; Malomed, B A; Leblond, H; Aleksić, N B; Lederer, F

    2010-01-01

    Complex Ginzburg-Landau (CGL) models of laser media (with the cubic-quintic nonlinearity) do not contain an effective diffusion term, which makes all vortex solitons unstable in these models. Recently, it has been demonstrated that the addition of a two-dimensional periodic potential, which may be induced by a transverse grating in the laser cavity, to the CGL equation stabilizes compound (four-peak) vortices, but the most fundamental "crater-shaped" vortices (CSVs), alias vortex rings, which are, essentially, squeezed into a single cell of the potential, have not been found before in a stable form. In this work we report families of stable compact CSVs with vorticity S=1 in the CGL model with the external potential of two different types: an axisymmetric parabolic trap, and the periodic potential. In both cases, we identify stability region for the CSVs and for the fundamental solitons (S=0). Those CSVs which are unstable in the axisymmetric potential break up into robust dipoles. All the vortices with S=2 a...

  7. Sensitivity analysis of CLIMEX parameters in modelling potential distribution of Lantana camara L.

    Directory of Open Access Journals (Sweden)

    Subhashni Taylor

    Full Text Available A process-based niche model of L. camara L. (lantana, a highly invasive shrub species, was developed to estimate its potential distribution using CLIMEX. Model development was carried out using its native and invasive distribution and validation was carried out with the extensive Australian distribution. A good fit was observed, with 86.7% of herbarium specimens collected in Australia occurring within the suitable and highly suitable categories. A sensitivity analysis was conducted to identify the model parameters that had the most influence on lantana distribution. The changes in suitability were assessed by mapping the regions where the distribution changed with each parameter alteration. This allowed an assessment of where, within Australia, the modification of each parameter was having the most impact, particularly in terms of the suitable and highly suitable locations. The sensitivity of various parameters was also evaluated by calculating the changes in area within the suitable and highly suitable categories. The limiting low temperature (DV0, limiting high temperature (DV3 and limiting low soil moisture (SM0 showed highest sensitivity to change. The other model parameters were relatively insensitive to change. Highly sensitive parameters require extensive research and data collection to be fitted accurately in species distribution models. The results from this study can inform more cost effective development of species distribution models for lantana. Such models form an integral part of the management of invasive species and the results can be used to streamline data collection requirements for potential distribution modelling.

  8. Simulation modeling of the probability of magmatic disruption of the potential Yucca Mountain Site

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, B.M.; Perry, F.V.; Valentine, G.A. [Los Alamos National Lab., NM (United States); Wallmann, P.C.; Kossik, R. [Golder Associates, Inc., Redmond, WA (United States)

    1993-11-01

    The first phase of risk simulation modeling was completed for the probability of magmatic disruption of a potential repository at Yucca Mountain. E1, the recurrence rate of volcanic events, is modeled using bounds from active basaltic volcanic fields and midpoint estimates of E1. The cumulative probability curves for El are generated by simulation modeling using a form of a triangular distribution. The 50% estimates are about 5 to 8 {times} 10{sup 8} events yr{sup {minus}1}. The simulation modeling shows that the cumulative probability distribution for E1 is more sensitive to the probability bounds then the midpoint estimates. The E2 (disruption probability) is modeled through risk simulation using a normal distribution and midpoint estimates from multiple alternative stochastic and structural models. The 50% estimate of E2 is 4.3 {times} 10{sup {minus}3} The probability of magmatic disruption of the potential Yucca Mountain site is 2.5 {times} 10{sup {minus}8} yr{sup {minus}1}. This median estimate decreases to 9.6 {times} 10{sup {minus}9} yr{sup {minus}1} if E1 is modified for the structural models used to define E2. The Repository Integration Program was tested to compare releases of a simulated repository (without volcanic events) to releases from time histories which may include volcanic disruptive events. Results show that the performance modeling can be used for sensitivity studies of volcanic effects.

  9. Models of intracellular mechanisms of plant bioelectrical potentials caused by combined stimulation

    Directory of Open Access Journals (Sweden)

    D. V. Chernetchenko

    2014-10-01

    Full Text Available This paper deals with bioelectrical potentials of the plants recorded during different types of stimuli and combined stimulus as well. All registrations were observed on the leaves of the corn. We used different stimuli, such as cold, heat, photo- and electrical stimulation, and certain combination of this stimuli. Hardware and software system for automated recording of bioelectrical potentials has been successfully used in this work. We proposed the universal pattern of bioelectrical potentials’ recording which allowed to detect the response of the biological object to different stimuli and various combinations of these stimuli. This pattern can be used for the deeper understanding of biological mechanisms of electrical potentials’ generation in cells and discovering of processes of accommodation of whole organisms to these stimuli. Integrated system of recording and biometrical processing was used for analysis of corn leaves electrical responses to the thermal stimuli. The dynamics of these potentials was studied, with the quantitative analysis of the potential level stabilization.We calculated the ratio of amplitude of response potentials to the first response amplitude. Mathematical models of the plant cell were used for studying of intracellular mechanisms of biopotentials gereration. As a result of modeling, we revealed that electrical response of the cells was based on selectiveconductivity of cell membrane for Н+ and Ca2+ ions. Therefore, we showed the biophysical relation of plant potentials to underlying intracellular biophysical mechanisms during thermal and combined stimulation.

  10. New statistical potential for quality assessment of protein models and a survey of energy functions

    Directory of Open Access Journals (Sweden)

    Rykunov Dmitry

    2010-03-01

    Full Text Available Abstract Background Scoring functions, such as molecular mechanic forcefields and statistical potentials are fundamentally important tools in protein structure modeling and quality assessment. Results The performances of a number of publicly available scoring functions are compared with a statistical rigor, with an emphasis on knowledge-based potentials. We explored the effect on accuracy of alternative choices for representing interaction center types and other features of scoring functions, such as using information on solvent accessibility, on torsion angles, accounting for secondary structure preferences and side chain orientation. Partially based on the observations made, we present a novel residue based statistical potential, which employs a shuffled reference state definition and takes into account the mutual orientation of residue side chains. Atom- and residue-level statistical potentials and Linux executables to calculate the energy of a given protein proposed in this work can be downloaded from http://www.fiserlab.org/potentials. Conclusions Among the most influential terms we observed a critical role of a proper reference state definition and the benefits of including information about the microenvironment of interaction centers. Molecular mechanical potentials were also tested and found to be over-sensitive to small local imperfections in a structure, requiring unfeasible long energy relaxation before energy scores started to correlate with model quality.

  11. The JRC-EU-TIMES model. Bioenergy potentials for EU and neighbouring countries

    NARCIS (Netherlands)

    Ruiz, Pablo; Sgobbi, Alessandra; Nijs, Wouter; Thiel, Christian; Longa, Dalla Francesco; Kober, Tom; Elbersen, Berien; Hengeveld, G.M.

    2015-01-01

    The JRC-EU-TIMES is a partial equilibrium energy system model maintained by the Institute for Energy and Transport (IET) of the Joint Research Centre (JRC) to analyse the role of energy technologies development and their potential contribution to decarbonisation pathways of the energy system. The te

  12. Application of multimedia models for screening assessment of long-range transport potential and overall persistence.

    NARCIS (Netherlands)

    Klasmeier, Jörg; Matthies, Michael; Macleod, Matthew; Fenner, Kathrin; Scheringer, Martin; Stroebe, Maximilian; Gall, Anne Christine le; McKone, Thomas; Meent, Dik van de; Wania, Frank

    2006-01-01

    We propose a multimedia model-based methodology to evaluate whether a chemical substance qualifies as POP-like based on overall persistence (Pov) and potential for long-range transport (LRTP). It relies upon screening chemicals against the Pov and LRTP characteristics of selected reference chemicals

  13. Crossover to potential energy landscape dominated dynamics in a model glass-forming liquid

    DEFF Research Database (Denmark)

    Schrøder, Thomas; Sastry, S.; Dyre, Jeppe;

    2000-01-01

    An equilibrated model glass-forming liquid is studied by mapping successive configurations produced by molecular dynamics simulation onto a time series of inherent structures (local minima in the potential energy). Using this "inherent dynamics" approach we find direct numerical evidence for the ...

  14. A new cellular automata model of traffic flow with negative exponential weighted look-ahead potential

    Science.gov (United States)

    Ma, Xiao; Zheng, Wei-Fan; Jiang, Bao-Shan; Zhang, Ji-Ye

    2016-10-01

    With the development of traffic systems, some issues such as traffic jams become more and more serious. Efficient traffic flow theory is needed to guide the overall controlling, organizing and management of traffic systems. On the basis of the cellular automata model and the traffic flow model with look-ahead potential, a new cellular automata traffic flow model with negative exponential weighted look-ahead potential is presented in this paper. By introducing the negative exponential weighting coefficient into the look-ahead potential and endowing the potential of vehicles closer to the driver with a greater coefficient, the modeling process is more suitable for the driver’s random decision-making process which is based on the traffic environment that the driver is facing. The fundamental diagrams for different weighting parameters are obtained by using numerical simulations which show that the negative exponential weighting coefficient has an obvious effect on high density traffic flux. The complex high density non-linear traffic behavior is also reproduced by numerical simulations. Project supported by the National Natural Science Foundation of China (Grant Nos. 11572264, 11172247, 11402214, and 61373009).

  15. Archimedes' Law and Potential Energy: Modelling and Simulation with a Spreadsheet.

    Science.gov (United States)

    Silva, A. Alberto

    1998-01-01

    Addresses some basic aspects of Archimedes' law. Focus is on potential energy relationships so as to elucidate some common misunderstandings and to facilitate making bridges with other physical topics. A spreadsheet model is used as a simulation tool. (Author/NB)

  16. Regional models for distributed flash-flood nowcasting: towards an estimation of potential impacts and damages

    Directory of Open Access Journals (Sweden)

    Le Bihan Guillaume

    2016-01-01

    Full Text Available Flash floods monitoring systems developed up to now generally enable a real-time assessment of the potential flash-floods magnitudes based on highly distributed hydrological models and weather radar records. The approach presented here aims to go one step ahead by offering a direct assessment of the potential impacts of flash floods on inhabited areas. This approach is based on an a priori analysis of the considered area in order (1 to evaluate based on a semi-automatic hydraulic approach (Cartino method the potentially flooded areas for different discharge levels, and (2 to identify the associated buildings and/or population at risk based on geographic databases. This preliminary analysis enables to build a simplified impact model (discharge-impact curve for each river reach, which can be used to directly estimate the importance of potentially affected assets based on the outputs of a distributed rainfall-runoff model. This article presents a first case study conducted in the Gard region (south eastern France. The first validation results are presented in terms of (1 accuracy of the delineation of the flooded areas estimated based on the Cartino method and using a high resolution DTM, and (2 relevance and usefulness of the impact model obtained. The impacts estimated at the event scale will now be evaluated in a near future based on insurance claim data provided by CCR (Caisse Centrale de Réassurrance.

  17. Modelling soil organic carbon in Danish agricultural soils suggests low potential for future carbon sequestration

    DEFF Research Database (Denmark)

    Taghizadeh-Toosi, Arezoo; Olesen, Jørgen Eivind

    2016-01-01

    Soil organic carbon (SOC) is in active exchange with the atmosphere. The amount of organic carbon (OC) input into the soil and SOC turnover rate are important for predicting the carbon (C) sequestration potential of soils subject to changes in land-use and climate. The C-TOOL model was developed...

  18. Static Potential in the SU(2)-Higgs Model and the Electroweak Phase Transition

    CERN Document Server

    Piróth, A

    1999-01-01

    We present a one-loop calculation of the static potential in the SU(2)-Higgs model. The connection to the coupling constant definition used in lattice simulations is clarified. The consequences in comparing lattice simulations and perturbative results for finite temperature applications are explored.

  19. Corporate marketing potential assessment model in the context of operational, tactical and strategic levels

    Directory of Open Access Journals (Sweden)

    L.V. Potrashkova

    2013-12-01

    Full Text Available The aim of the article. The aim of this research is to develope the mathematic model structure of result-oriented evaluation of corporate marketing potential in the context of management potential levels (operational, tactical and strategic that takes into account multiple possible uses of marketing resources and various options for the development of corporate environment. The results of the analysis. The new scientific result of this research is represented by the developed structure of the system of analytical mathematic models for assessing marketing potential of the company in the context of its management levels – operational, tactical and strategic. According to the proposed system of models every level of marketing potential (operational, tactical and strategic is described through a set of possible enterprise production sales volumes for different states of the environment parameters and the parameters of a certain level of marketing resources management at corresponding period of time (short, medium and long term. The proposed system of models has the following clue characteristics: marketing potential assessment is based on the result-oriented approach. It characterizes enterprise capability for creating demand for its products in different conditions of corporate environment and for different variants of managerial decisions concerning different parameters of production promotion and distribution (e.g. for different pricing options; different variants of corporate investment and innovations program; marketing potential assessment is implemented in the context of management levels of the potential – operational, tactical and strategic – so, it reflects operational, tactical and strategic capabilities of the company concerning production promotion and distribution; the models for assessing different levels of potential (operational, tactical and strategic differ in such of ways: by specification of the resources` characteristics

  20. A System Model of Increasing the Investment Potential of Technologically Unrelated Sectors

    Directory of Open Access Journals (Sweden)

    Melnyk Alexander G.

    2016-02-01

    Full Text Available The article presents a theoretical substantiation and the progress of practical application of the method for evaluating lagged effects of increasing the investment potential of interaction between industries in meso-level innovation systems on the example of the high-tech sector of Ukraine. The interaction data are considered in terms of their formation in such technologically unrelated sectors as the industrial sector and sector of education and sciences. It has been determined that the analytical basis to form the models of increasing the investment potential in innovation systems of meso-level should be presented by a comprehensive integrated assessment of all sectors involved in the reproduction process including technologically unrelated sectors of highly structured innovative systems. There has been proposed a system model of increasing the investment potential of the high-tech sector taking into account the optimization and synergy effects for system decisions concerning technologically unrelated sectors in economic systems of innovation type of reproduction.

  1. Modeling and simulation of ion channels and action potentials in taste receptor cells

    Institute of Scientific and Technical Information of China (English)

    CHEN PeiHua; LIU Xiaodong; ZHANG Wei; ZHOU Jun; WANG Ping; YANG Wei; LUO JianHong

    2009-01-01

    Based on patch clamp data on the ionic currents of rat taste receptor cells,a mathematical model of mammalian taste receptor cells was constructed to simulate the action potentials of taste receptor cells and their corresponding ionic components,including voltage-gated Na~+ currents and outward delayed rectifier K~+ currents.Our simulations reproduced the action potentials of taste receptor cells in response to electrical stimuli or sour tastants.The kinetics of ion channels and their roles in action potentials of taste receptor cells were also analyzed.Our prototype model of single taste receptor cell and simulation results presented in this paper provide the basis for the further study of taste information processing in the gustatory system.

  2. Modeling and simulation of ion channels and action potentials in taste receptor cells

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on patch clamp data on the ionic currents of rat taste receptor cells, a mathematical model of mammalian taste receptor cells was constructed to simulate the action potentials of taste receptor cells and their corresponding ionic components, including voltage-gated Na+ currents and outward delayed rectifier K+ currents. Our simulations reproduced the action potentials of taste receptor cells in response to electrical stimuli or sour tastants. The kinetics of ion channels and their roles in action potentials of taste receptor cells were also analyzed. Our prototype model of single taste receptor cell and simulation results presented in this paper provide the basis for the further study of taste information processing in the gustatory system.

  3. Streaming potential modeling in fractured rock: Insights into the identification of hydraulically active fractures

    CERN Document Server

    Roubinet, D; Jougnot, D; Irving, J

    2016-01-01

    Numerous field experiments suggest that the self-potential (SP) geophysical method may allow for the detection of hydraulically active fractures and provide information about fracture properties. However, a lack of suitable numerical tools for modeling streaming potentials in fractured media prevents quantitative interpretation and limits our understanding of how the SP method can be used in this regard. To address this issue, we present a highly efficient two-dimensional discrete-dual-porosity approach for solving the fluid flow and associated self-potential problems in fractured rock. Our approach is specifically designed for complex fracture networks that cannot be investigated using standard numerical methods. We then simulate SP signals associated with pumping conditions for a number of examples to show that (i) accounting for matrix fluid flow is essential for accurate SP modeling and (ii) the sensitivity of SP to hydraulically active fractures is intimately linked with fracture-matrix fluid interaction...

  4. Estimating potential saving with energy consumption behaviour model in higher education institutions

    Directory of Open Access Journals (Sweden)

    Mohd Hafizal Ishak

    2016-11-01

    Full Text Available Towards sustainable Higher Education Institutions (HEIs, energy consumption behaviour is one of several issues that require an attention by facilities manager. Information from the behavioural aspect would be useful for facilities manager on managing the energy and determining potential energy saving. A lack of information negatively affects this aim. Hence, this paper proposes a methodology for assessing the energy consumption behaviour with the objective determining potential energy saving. The method used energy culture framework as basis and joined with centrographic approach and multiple-regression analysis. A self-administrated survey carried out involving 1400 respondents in selected HEIs. There are four types of energy use among students in HEIs namely, 'high', 'low', ‘medium’ and 'conserve' determined from the centrographic analysis. The energy consumption behaviour model was developed and tested against the holdout sample. Through the model's application, there is a vast potential for energy savings with over 55 kWh daily among the students.

  5. Predictive GIS Model for Potential Mapping of Cu, Pb, Zn Mineralization

    Institute of Scientific and Technical Information of China (English)

    Tarik. B. Benomar; BIAN Fuling

    2006-01-01

    The geologic features indicative of Cu, Pb, Zn mineral deposits in a area are fractures (structure), and host rock sediments. Datasets used include Cu, Pb, Zn deposit points record, geological data, remote sensing imagery (Landsat TM5). The mineral potential of the study area is assessed by means of GIS based geodata integration techniques for generating predictive maps. GIS predictive model for Cu, Pb, Zn potential was carried out in this study area (Weixi) using weight of evidence. The weights of evidence modeling techniques is the data driven method in which the spatial associations of the indicative geologic features with the known mineral occurrences in the area are quantified, and weights statistically assigned to the geologic features. The best predictive map generated by this method defines 24% the area having potential for Cu, Pb, Zn mineralization further exploration work.

  6. Test of the notch technique for determining the radial sensitivity of the optical model potential

    CERN Document Server

    Yang, Lei; Jia, Hui-ming; Xu, Xin-Xing; Ma, Nan-Ru; Sun, Li-Jie; Yang, Feng; Zhang, Huan-Qiao; Li, Zu-Hua; Wang, Dong-Xi

    2015-01-01

    Detailed investigations on the notch technique are performed on the ideal data generated by the optical model potential parameters extracted from the 16O+208Pb system at the laboratory energy of 129.5 MeV, to study the sensitivities of this technique on the model parameters as well as the experimental data. It is found that, for the perturbation parameters, a sufficient large reduced fraction and an appropriate small perturbation width are necessary to determine the accurate radial sensitivity; while for the potential parameters, almost no dependence was observed. For the experimental measurements, the number of data points has little influence for the heavy target system, and the relative inner information of the nuclear potential can be derived when the measurement extended to a lower cross section.

  7. Effect of Temporal Resolution of NDVI on Potential Evapotranspiration Estimation and Hydrological Model Performance

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Normalized difference vegetation index (NDVI) data, obtained from remote sensing information, are essential in the Shuttleworth-Wallace(S-W) model for estimation of evapotranspiration. In order to study the effect of temporal resolution of NDVI on potential evapotranspiration (PET) estimation and hydrological model performance,monthly and 10-day NDVI data set were used to estimate potential evapotranspiration from January 1985 to December 1987 in Huangnizhuang catchment, Anhui Province, China. The differences of the two calculation results were analyzed and used to drive the block-wise use of the TOPMODEL with the Muskingum-Cunge routing (BTOPMC) model to test the effect on model performance. The results show that both annual and monthly PETs estimated by 10-day NDVI are lower than those estimated by monthly NDVI. Annual PET from the vegetation root zone (PETr) lowers 9.77%-13.64% and monthly PETr lowers 3.28%-17.44% in the whole basin. PET from the vegetation interception (PETi) shows the same trend as PETr. In addition, temporal resolution of NDVI has more effect on PETr in summer and on PETi in winter. The correlation between PETr as estimated by 10-day NDVI and pan measurement (R2= 0.835)is better than that between monthly NDVI and pan measurement (R2 = 0.775). The two potential evapotranspiration estimates were used to drive the BTOPMC model and calibrate parameters, and model performance was found to be similar. In summary, the effect of temporal resolution of NDVI on potential evapotranspiration estimation is significant,but trivial on hydrological model performance.

  8. A hybrid dual-source model for potential evaporation and transpiration partitioning

    Science.gov (United States)

    Guan, Huade; Wilson, John L.

    2009-10-01

    SummaryPotential ET (PET) and partitioning of evaporation and transpiration are important information for hydrologic, ecologic, forest, and agricultural studies. Most PET models were developed in flat areas for agricultural purposes, with potential evaporation (PE) and potential transpiration (PT) lumped together. To quantify the evaporative demand for sloped surfaces with a wide range of vegetation coverage, a topography- and vegetation-based surface energy partitioning algorithm for PE and PT estimates (TVET) is developed. In this paper, vegetation-based part of the TVET model is presented. TVET employs a hybrid of layer and patch approaches in partitioning energy and routing vapor and sensible heat. It first uses a layer approach to partition available energy for the canopy and the soil components. The available energy of each component is then partitioned into potential latent heat and sensible heat, using a patch approach. Hybrid of these two approaches results in simple model formulae, while coupling the two components in terms of energy partitioning and aerodynamic resistances for heat and vapor transfer. TVET is different from a layer-approach model in that it distinguishes the difference in evaporation from inter-canopy soil and from under-canopy soil, and limits convective transfer contribution to transpiration only for vegetation-cover fraction. TVET is different from a patch-approach model in that it allows evaporation occurring from under-canopy soil, and that vegetation effect on both evaporation and transpiration is well considered. These features make TVET sensitive to vegetation effect on surface energy partitioning. The model is demonstrated and tested with Penman-Monteith and Shuttleworth-Wallace models, and with observations, at four sites covering mountain, basin floor, and riparian environments. The results indicate that TVET can be used to estimate PE and PT partitioning for a wide range of surfaces with different fractional vegetation cover

  9. How should we interrogate the hypothalamic-pituitary-adrenal axis in patients with suspected hypopituitarism?

    Science.gov (United States)

    Garrahy, Aoife; Agha, Amar

    2016-06-17

    Hypopituitarism is deficiency of one or more pituitary hormones, of which adrenocorticotrophic hormone (ACTH) deficiency is the most serious and potentially life-threatening. It may occur in isolation or, more commonly as part of more widespread pituitary failure. Diagnosis requires demonstration of subnormal cortisol rise in response to stimulation with hypoglycemia, glucagon, ACTH(1-24) or in the setting of acute illness. The choice of diagnostic test should be individualised for the patient and clinical scenario. A random cortisol and ACTH level may be adequate in making a diagnosis in an acutely ill patient with a suspected adrenal crisis e.g. pituitary apoplexy. Often however, dynamic assessment of cortisol reserve is needed. The cortisol response is both stimulus and assay- dependent and normative values should be derived locally. Results must be interpreted within clinical context and with understanding of potential pitfalls of the test used.

  10. Differential diagnosis of Mendelian and mitochondrial disorders in patients with suspected multiple sclerosis.

    Science.gov (United States)

    Weisfeld-Adams, James D; Katz Sand, Ilana B; Honce, Justin M; Lublin, Fred D

    2015-03-01

    Several single gene disorders share clinical and radiologic characteristics with multiple sclerosis and have the potential to be overlooked in the differential diagnostic evaluation of both adult and paediatric patients with multiple sclerosis. This group includes lysosomal storage disorders, various mitochondrial diseases, other neurometabolic disorders, and several other miscellaneous disorders. Recognition of a single-gene disorder as causal for a patient's 'multiple sclerosis-like' phenotype is critically important for accurate direction of patient management, and evokes broader genetic counselling implications for affected families. Here we review single gene disorders that have the potential to mimic multiple sclerosis, provide an overview of clinical and investigational characteristics of each disorder, and present guidelines for when clinicians should suspect an underlying heritable disorder that requires diagnostic confirmation in a patient with a definite or probable diagnosis of multiple sclerosis.

  11. Modelling and Analysis of Electrical Potentials Recorded in Microelectrode Arrays (MEAs).

    Science.gov (United States)

    Ness, Torbjørn V; Chintaluri, Chaitanya; Potworowski, Jan; Łęski, Szymon; Głąbska, Helena; Wójcik, Daniel K; Einevoll, Gaute T

    2015-10-01

    Microelectrode arrays (MEAs), substrate-integrated planar arrays of up to thousands of closely spaced metal electrode contacts, have long been used to record neuronal activity in in vitro brain slices with high spatial and temporal resolution. However, the analysis of the MEA potentials has generally been mainly qualitative. Here we use a biophysical forward-modelling formalism based on the finite element method (FEM) to establish quantitatively accurate links between neural activity in the slice and potentials recorded in the MEA set-up. Then we develop a simpler approach based on the method of images (MoI) from electrostatics, which allows for computation of MEA potentials by simple formulas similar to what is used for homogeneous volume conductors. As we find MoI to give accurate results in most situations of practical interest, including anisotropic slices covered with highly conductive saline and MEA-electrode contacts of sizable physical extensions, a Python software package (ViMEAPy) has been developed to facilitate forward-modelling of MEA potentials generated by biophysically detailed multicompartmental neurons. We apply our scheme to investigate the influence of the MEA set-up on single-neuron spikes as well as on potentials generated by a cortical network comprising more than 3000 model neurons. The generated MEA potentials are substantially affected by both the saline bath covering the brain slice and a (putative) inadvertent saline layer at the interface between the MEA chip and the brain slice. We further explore methods for estimation of current-source density (CSD) from MEA potentials, and find the results to be much less sensitive to the experimental set-up.

  12. A physical surface-potential-based drain current model for polysilicon thin-film transistors

    Institute of Scientific and Technical Information of China (English)

    Li Xiyue; Deng Wanling; Huang Junkai

    2012-01-01

    A physical drain current model of polysilicon thin-film transistors based on the charge-sheet model,the density of trap states and surface potential is proposed.The model uses non-iterative calculations,which are single-piece and valid in all operation regions above flat-band voltage.The distribution of the trap states,including both Gaussian deep-level states and exponential band-tail states,is also taken into account,and parameter extraction of trap state distribution is developed by the optoelectronic modulation spectroscopy measurement method.Comparisons with the available experimental data are accomplished,and good agreements are obtained.

  13. Surface-potential-based physical compact model for graphene field effect transistor

    Science.gov (United States)

    Wang, Lingfei; Peng, Songang; Wang, Wei; Xu, Guangwei; Ji, Zhuoyu; Lu, Nianduan; Li, Ling; Jin, Zhi; Liu, Ming

    2016-08-01

    A surface potential based physical compact model for a graphene field effect transistor is proposed, including Boltzmann transport and thermally activated transport. We verified it by the experiments and Gummel symmetry test, showing good accuracy and continuity over a wide range of operation regions. Coded in Verilog-A, this model provides physics-based consistent DC and AC characteristics, which can be easily embedded into a vendor CAD tool to simulate circuits. Based on this model, a direct insight into the relationship between physical parameters and circuit performances can be achieved.

  14. Billiard representation for multidimensional multi-scalar cosmological model with exponential potentials

    CERN Document Server

    Dehnen, H; Melnikov, V N

    2003-01-01

    Multidimensional cosmological-type model with n Einstein factor spaces in the theory with l scalar fields and multiple exponential potential is considered. The dynamics of the model near the singularity is reduced to a billiard on the (N-1)-dimensional Lobachevsky space H^{N-1}, N = n+l. It is shown that for n > 1 the oscillating behaviour near the singularity is absent and solutions have an asymptotical Kasner-like behavior. For the case of one scale factor (n =1) billiards with finite volumes (e.g. coinciding with that of the Bianchi-IX model) are described and oscillating behaviour of scalar fields near the singularity is obtained.

  15. Evaluation of Water Resource Potential in Anhui Province Based on Allocation Model

    Institute of Scientific and Technical Information of China (English)

    Zhenyu; XU; Yanlin; ZHOU

    2013-01-01

    The nature of water resources can be divided into four categories:water for life,water for agriculture,water for industry,and water for ecology.On this basis,the regional right allocation model for water resources is built,and to make the model more operable,we calculate the weight of the key factors of model(four different types of water use:life,agriculture,industry,ecology),using analytic hierarchy process(AHP).Finally,based on the amount of available water resources in Anhui Province,we evaluate the water resource potential in Anhui Province according to the principle of rational allocation.

  16. Scalar-field cosmological and collapse models with general self-interaction potentials

    Energy Technology Data Exchange (ETDEWEB)

    Giambo, Roberto; Giannoni, Fabio [Dipartimento di Matematica e Informatica, Universita di Camerino (Italy); Magli, Giulio, E-mail: roberto.giambo@unicam.i, E-mail: fabio.giannoni@unicam.i, E-mail: magli@mate.polimi.i [Dipartimento di Matematica, Politecnico di Milano (Italy)

    2009-10-01

    We present the results of the investigation of a wide class of self-interacting, self-gravitating homogeneous scalar fields models, characterized by quite general conditions on the scalar field potential, and including both asymptotically polynomial and exponential behaviors. We show that the generic evolution is always divergent in a finite time, and this result is used to construct cosmological models as well as radiating collapsing star models of the Vaidya type - for the latter it turns out that black holes are generically formed.

  17. Averaged Solvent Embedding Potential Parameters for Multiscale Modeling of Molecular Properties.

    Science.gov (United States)

    Beerepoot, Maarten T P; Steindal, Arnfinn Hykkerud; List, Nanna Holmgaard; Kongsted, Jacob; Olsen, Jógvan Magnus Haugaard

    2016-04-12

    We derive and validate averaged solvent parameters for embedding potentials to be used in polarizable embedding quantum mechanics/molecular mechanics (QM/MM) molecular property calculations of solutes in organic solvents. The parameters are solvent-specific atom-centered partial charges and isotropic polarizabilities averaged over a large number of geometries of solvent molecules. The use of averaged parameters reduces the computational cost to obtain the embedding potential, which can otherwise be a rate-limiting step in calculations involving large environments. The parameters are evaluated by analyzing the quality of the resulting molecular electrostatic potentials with respect to full QM potentials. We show that a combination of geometry-specific parameters for solvent molecules close to the QM region and averaged parameters for solvent molecules further away allows for efficient polarizable embedding multiscale modeling without compromising the accuracy. The results are promising for the development of general embedding parameters for biomolecules, where the reduction in computational cost can be considerable.

  18. CT Pulmonary Angiography and Suspected Acute Pulmonary Embolism

    Energy Technology Data Exchange (ETDEWEB)

    Enden, T.; Kloew, N.E. [Ullevaal Univ. Hospital, Oslo (Norway). Dept. of Cardiovascular Radiology

    2003-05-01

    Purpose: To evaluate the use and quality of CT pulmonary angiography in our department, and to relate the findings to clinical parameters and diagnoses. Material and Methods: A retrospective study of 324 consecutive patients referred to CT pulmonary angiography with clinically suspected pulmonary embolism (PE). From the medical records we registered clinical parameters, blood gases, D-dimer, risk factors and the results of other relevant imaging studies. Results: 55 patients (17%) had PE detected on CT. 39 had bilateral PE, and 8 patients had isolated peripheral PE. 87% of the examinations showing PE had satisfactory filling of contrast material including the segmental pulmonary arteries, and 60% of the subsegmental arteries. D-dimer test was performed in 209 patients, 85% were positive. A negative D-dimer ruled out PE detected at CT. Dyspnea and concurrent symptoms or detection of deep vein thrombosis (DVT), contraceptive pills and former venous thromboembolism (VTE) were associated with PE. The presence of only one clinical parameter indicated a negative PE diagnosis (p < 0.017), whereas two or more suggested a positive PE diagnosis (p < 0.002). CT also detected various ancillary findings such as consolidation, pleural effusion, nodule or tumor in nearly half of the patients; however, there was no association with the PE diagnosis. Conclusion: The quality of CT pulmonary angiography was satisfactory as a first-line imaging of PE. CT also showed additional pathology of importance in the chest. Our study confirmed that a negative D-dimer ruled out clinically suspected VTE.

  19. Murder by insulin: suspected, purported and proven-a review.

    Science.gov (United States)

    Marks, Vincent

    2009-04-01

    Murder by insulin-whether attempted, suspected or proven-is rare. Only 66 cases worldwide could be found for this review. A conviction was secured in 31 cases and additional weapon was employed in 11. Differentiation of attempted homicide from Munchausen syndrome by proxy in the young and from 'mercy killing' in the elderly was not attempted. Most perpetrators were close relatives and most victims were alive when discovered and responded to treatment. Hypoglycaemia is the first clue to homicidal insulin use in living subjects and requires the demonstration of a plasma insulin concentration of generally more than 1000 pmol/L and undetectable plasma C-peptide concentration to establish the diagnosis. Serum glucose measurements are valueless in victims found dead. The presence near the body of insulin vials, syringes or needles, loose talk by the suspected perpetrator or their ready access to insulin may be the only clue. The demonstration of insulin in tissue around an injection site by immunohistopathology or by measuring it in an extract clinches the diagnosis. Immunoassays suitable for clinical use to detect and measure insulin and C-peptide are subject to random errors and cannot be relied upon unless special precautions including separation by gel filtration or HPLC are undertaken prior to analysis. They do not detect or measure accurately a new generation of synthetic insulin analogues. Mass spectrometry will be required to do this and to validate clinical immunoassays, upon which convictions have always had to rely in the past. Copyright 2009 John Wiley & Sons, Ltd.

  20. MRI diagnosis of suspected atlanto-occipital dissociation in childhood

    Energy Technology Data Exchange (ETDEWEB)

    Grabb, B.C.; Frye, T.A.; Hedlund, G.L.; Vaid, Y.N.; Royal, S.A. [Department of Radiology, The Children`s Hospital of Alabama, Birmingham (United States); Grabb, P.A. [Department of Neurosurgery, University of Alabama at Birmingham (United States)

    1999-04-01

    Objective. To demonstrate the utility of magnetic resonance (MR) imaging in the diagnosis of complete and partial ligamentous injuries in patients with suspected atlanto-occipital dissociation (AOD). Materials and methods. Five patients with suspected AOD had MR imaging performed within an average of 4 days after injury. MR scans were reviewed with specific analysis of craniocervical ligamentous structures. Charts were reviewed to obtain clinical information regarding presentation, treatment, hospital course, and outcome. Results. Two patients demonstrated MR evidence of complete AOD. One had disruption of all visualized major ligamentous structures at the craniocervical junction with anterolisthesis and evidence of cord damage. The second had injuries to the tectorial membrane, superior band of the cruciform ligament, apical ligament, and interspinous ligament at C 1-2. The remaining three patients sustained incomplete severance of the ligamentous structures at the craniocervical junction. All patients demonstrated subtle radiographic findings suggestive of AOD, including soft tissue swelling at the craniocervical junction without fracture. The two patients with complete AOD died. The three patients with partial AOD were treated with stabilization. On follow-up, these three children were asymptomatic following their craniocervical injury. Conclusion. MR imaging of acute AOD provides accurate identification of the craniocervical ligaments injured, classification of full versus partial ligamentous disruption, and analysis of accompanying spinal cord injury. This information is important for early appropriate neurosurgical management and preservation of neurologic function in survivors. (orig.) With 7 figs., 1 tab., 14 refs.

  1. LKB1 and lung cancer: more than the usual suspects.

    Science.gov (United States)

    Shah, Usman; Sharpless, Norman E; Hayes, D Neil

    2008-05-15

    Often, the problem in cancer research is figuring out how a gene or pathway works in regulating cellular transformation. The question of what RAS activates or PTEN inhibits have been classic dilemmas of modern cancer biology. In these cases, biochemical and genetic studies have provided us with a fairly clear picture of the cancer relevant functions of these genes. For LKB1, a more recently identified human tumor suppressor gene, however, the problem is different. This serine-threonine kinase that is conserved from yeast to mammals seems to play a role in many diverse cellular pathways. Therefore, although elegant functional and genetic approaches have established critical roles for LKB1 in the regulation of metabolism, motility, polarity, and the cell cycle, the role(s) responsible for its true tumor suppressor function(s) is unknown. One is reminded of an Agatha Christie murder mystery where nearly every character in the book has reason to be suspected of committing the crime-there are too many suspects for how LKB1 might repress lung cancer.

  2. Climate change and the potential global distribution of Aedes aegypti: spatial modelling using GIS and CLIMEX.

    Science.gov (United States)

    Khormi, Hassan M; Kumar, Lalit

    2014-05-01

    We examined the potential added risk posed by global climate change on the dengue vector Aedes aegypti abundance using CLIMEX, a powerful tool for exploring the relationship between the fundamental and realised niche of any species. After calibrating the model using data from several knowledge domains, including geographical distribution records, we estimated potential distributions of the mosquito under current and future potential scenarios. The impact of climate change on its potential distribution was assessed with two global climate models, the CSIRO-Mk3.0 and the MIROC-H, run with two potential, future emission scenarios (A1B and A2) published by the Intergovernmental Panel on Climate Change. We compared today's climate situation with two arbitrarily chosen future time points (2030 and 2070) to see the impact on the worldwide distribution of A. aegypti . The model for the current global climate indicated favourable areas for the mosquito within its known distribution in tropical and subtropical areas. However, even if much of the tropics and subtropics will continue to be suitable, the climatically favourable areas for A. aegypti globally are projected to contract under the future scenarios produced by these models, while currently unfavourable areas, such as inland Australia, the Arabian Peninsula, southern Iran and some parts of North America may become climatically favourable for this mosquito species. The climate models for the Aedes dengue vector presented here should be useful for management purposes as they can be adapted for decision/making regarding allocation of resources for dengue risk toward areas where risk infection remains and away from areas where climatic suitability is likely to decrease in the future.

  3. Noisy unmaskers of multistability of periodic rhythms in a model of the ventricular cardiac action potential

    Science.gov (United States)

    Surovyatkina, Elena; Egorchenkov, Roman; Ivanov, Guennady

    2007-06-01

    The coexistence of different dynamical regimes of cardiac cell-model at a fixed set of stimulation parameters, i.e. multistability, revealed by noise is presented in this paper. Numerical simulations are performed using Luo-Rudy (LR1) action potential model. Numerical experiments with LR1 model conducted via noisy periodical stimulation showed the coexistence of several periodic rhythms. Weak noise in period of stimulation causes a hopping process between all the (meta-) stable rhythms of cell-model. This process is reflected in several parallel branches of the bifurcation diagram: noise unveils new, invisible before, stable rhythms which could appear in this model at different initial conditions. The phenomenon of multistability is directly evidenced by other numerical experiments: we have established the multistability property of a cell consisting in the fact that different initial conditions of stimulation (different extrasystole application times) lead to different stable periodic rhythms. We have obtained the shaping of attraction basins on the action potential curves. Such basins of attraction contain a set of initial conditions which determinate a stable periodic rhythm. We have found a close association between the attraction basins of the complex rhythms on the curves of action potential and the cardiac vulnerable windows on ECG record, during which extra stimuli can induce life threatening arrhythmias. Obtained results allow us to make a conclusion that multistability is very important for the electrical conduction system of the heart from the cell level to the integrated function of the heart.

  4. Baltes' SOC model of successful ageing as a potential framework for stroke rehabilitation.

    Science.gov (United States)

    Donnellan, C; O'Neill, D

    2014-01-01

    The aim of this paper is to explore approaches used to address some stroke rehabilitation interventions and to examine the potential use of one of the life-span theories called the Baltes' model of selective optimisation with compensation (SOC) as a potential framework. Some of the key considerations for a stroke rehabilitation intervention framework are highlighted including accommodating for the life management changes post stroke, alterations in self-regulation, acknowledge losses and focusing on a person-centred approach for transition from acute rehabilitation to the home or community setting. The Baltes' SOC model is then described in terms of these considerations for a stroke rehabilitation intervention framework. The Baltes' SOC model may offer further insights, including ageing considerations, for stroke rehabilitation approaches and interventions. It has potential to facilitate some of the necessary complexities of adjustment required in stroke rehabilitation. However, further development in terms of empirical support is required for using the model as a framework to structure stroke rehabilitation intervention. Implications for Rehabilitation There is a scarcity of theoretical frameworks that can facilitate and be inclusive for all the necessary complexities of adjustment, required in stroke rehabilitation. In addition to motor recovery post stroke, rehabilitation intervention frameworks should be goal orientated; address self-regulatory processes; be person-centred and use a common language for goal planning, setting and attainment. The Baltes' SOC model is one such framework that may address some of the considerations for stroke rehabilitation, including motor recovery and other life management aspects.

  5. A potential model for sodium chloride solutions based on the TIP4P/2005 water model

    Science.gov (United States)

    Benavides, A. L.; Portillo, M. A.; Chamorro, V. C.; Espinosa, J. R.; Abascal, J. L. F.; Vega, C.

    2017-09-01

    Despite considerable efforts over more than two decades, our knowledge of the interactions in electrolyte solutions is not yet satisfactory. Not even one of the most simple and important aqueous solutions, NaCl(aq), escapes this assertion. A requisite for the development of a force field for any water solution is the availability of a good model for water. Despite the fact that TIP4P/2005 seems to fulfill the requirement, little work has been devoted to build a force field based on TIP4P/2005. In this work, we try to fill this gap for NaCl(aq). After unsuccessful attempts to produce accurate predictions for a wide range of properties using unity ionic charges, we decided to follow recent suggestions indicating that the charges should be scaled in the ionic solution. In this way, we have been able to develop a satisfactory non-polarizable force field for NaCl(aq). We evaluate a number of thermodynamic properties of the solution (equation of state, maximum in density, enthalpies of solution, activity coefficients, radial distribution functions, solubility, surface tension, diffusion coefficients, and viscosity). Overall the results for the solution are very good. An important achievement of our model is that it also accounts for the dynamical properties of the solution, a test for which the force fields so far proposed failed. The same is true for the solubility and for the maximum in density where the model describes the experimental results almost quantitatively. The price to pay is that the model is not so good at describing NaCl in the solid phase, although the results for several properties (density and melting temperature) are still acceptable. We conclude that the scaling of the charges improves the overall description of NaCl aqueous solutions when the polarization is not included.

  6. Modeling the electrostatic potential of asymmetric lipopolysaccharide membranes: the MEMPOT algorithm implemented in DelPhi.

    Science.gov (United States)

    Dias, Roberta P; Li, Lin; Soares, Thereza A; Alexov, Emil

    2014-07-15

    Four chemotypes of the rough lipopolysaccharides (LPS) membrane from Pseudomonas aeruginosa were investigated by a combined approach of explicit water molecular dynamics (MD) simulations and Poisson-Boltzmann continuum electrostatics with the goal to deliver the distribution of the electrostatic potential across the membrane. For the purpose of this investigation, a new tool for modeling the electrostatic potential profile along the axis normal to the membrane, MEMbrane POTential (MEMPOT), was developed and implemented in DelPhi. Applying MEMPOT on the snapshots obtained by MD simulations, two observations were made: (a) the average electrostatic potential has a complex profile but is mostly positive inside the membrane due to the presence of Ca(2+) ions, which overcompensate for the negative potential created by lipid phosphate groups; and (b) correct modeling of the electrostatic potential profile across the membrane requires taking into account the water phase, while neglecting it (vacuum calculations) results in dramatic changes including a reversal of the sign of the potential inside the membrane. Furthermore, using DelPhi to assign different dielectric constants for different regions of the LPS membranes, it was investigated whether a single frame structure before MD simulations with appropriate dielectric constants for the lipid tails, inner, and the external leaflet regions, can deliver the same average electrostatic potential distribution as obtained from the MD-generated ensemble of structures. Indeed, this can be attained by using smaller dielectric constant for the tail and inner leaflet regions (mostly hydrophobic) than for the external leaflet region (hydrophilic) and the optimal dielectric constant values are chemotype-specific.

  7. Rat models of spinal cord injury: from pathology to potential therapies

    Science.gov (United States)

    2016-01-01

    ABSTRACT A long-standing goal of spinal cord injury research is to develop effective spinal cord repair strategies for the clinic. Rat models of spinal cord injury provide an important mammalian model in which to evaluate treatment strategies and to understand the pathological basis of spinal cord injuries. These models have facilitated the development of robust tests for assessing the recovery of locomotor and sensory functions. Rat models have also allowed us to understand how neuronal circuitry changes following spinal cord injury and how recovery could be promoted by enhancing spontaneous regenerative mechanisms and by counteracting intrinsic inhibitory factors. Rat studies have also revealed possible routes to rescuing circuitry and cells in the acute stage of injury. Spatiotemporal and functional studies in these models highlight the therapeutic potential of manipulating inflammation, scarring and myelination. In addition, potential replacement therapies for spinal cord injury, including grafts and bridges, stem primarily from rat studies. Here, we discuss advantages and disadvantages of rat experimental spinal cord injury models and summarize knowledge gained from these models. We also discuss how an emerging understanding of different forms of injury, their pathology and degree of recovery has inspired numerous treatment strategies, some of which have led to clinical trials. PMID:27736748

  8. Three-Higgs-doublet models: symmetries, potentials and Higgs boson masses

    Energy Technology Data Exchange (ETDEWEB)

    Keus, Venus [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); Department of Physics, Royal Holloway, University of London,Egham Hill, Egham TW20 0EX (United Kingdom); Particle Physics Department, Rutherford Appleton Laboratory,Chilton, Didcot, Oxon OX11 0QX (United Kingdom); King, Stephen F. [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); Moretti, Stefano [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); Particle Physics Department, Rutherford Appleton Laboratory,Chilton, Didcot, Oxon OX11 0QX (United Kingdom)

    2014-01-13

    We catalogue and study three-Higgs-doublet models in terms of all possible allowed symmetries (continuous and discrete, Abelian and non-Abelian), where such symmetries may be identified as flavour symmetries of quarks and leptons. We analyse the potential in each case, and derive the conditions under which the vacuum alignments (0,0,v), (0,v,v) and (v,v,v) are minima of the potential. For the alignment (0,0,v), relevant for dark matter models, we calculate the corresponding physical Higgs boson mass spectrum. Motivated by supersymmetry, we extend the analysis to the case of three up-type Higgs doublets and three down-type Higgs doublets (six doublets in total). Many of the results are also applicable to flavon models where the three Higgs doublets are replaced by three electroweak singlets.

  9. A many-body potential approach to modelling the thermomechanical properties of actinide oxides.

    Science.gov (United States)

    Cooper, M W D; Rushton, M J D; Grimes, R W

    2014-03-12

    A many-body potential model for the description of actinide oxide systems, which is robust at high temperatures, is reported for the first time. The embedded atom method is used to describe many-body interactions ensuring good reproduction of a range of thermophysical properties (lattice parameter, bulk modulus, enthalpy and specific heat) between 300 and 3000 K for AmO2, CeO2, CmO2, NpO2, ThO2, PuO2 and UO2. Additionally, the model predicts a melting point for UO2 between 3000 and 3100 K, in close agreement with experiment. Oxygen-oxygen interactions are fixed across the actinide oxide series because it facilitates the modelling of oxide solid solutions. The new potential is also used to predict the energies of Schottky and Frenkel pair disorder processes.

  10. Multiscale Modeling, Simulation and Visualization and Their Potential for Future Aerospace Systems

    Science.gov (United States)

    Noor, Ahmed K. (Compiler)

    2002-01-01

    This document contains the proceedings of the Training Workshop on Multiscale Modeling, Simulation and Visualization and Their Potential for Future Aerospace Systems held at NASA Langley Research Center, Hampton, Virginia, March 5 - 6, 2002. The workshop was jointly sponsored by Old Dominion University's Center for Advanced Engineering Environments and NASA. Workshop attendees were from NASA, other government agencies, industry, and universities. The objectives of the workshop were to give overviews of the diverse activities in hierarchical approach to material modeling from continuum to atomistics; applications of multiscale modeling to advanced and improved material synthesis; defects, dislocations, and material deformation; fracture and friction; thin-film growth; characterization at nano and micro scales; and, verification and validation of numerical simulations, and to identify their potential for future aerospace systems.

  11. Empirical models for predicting wind potential for wind energy applications in rural locations of Nigeria

    Directory of Open Access Journals (Sweden)

    F. C. Odo, G. U. Akubue, S. U. Offiah, P. E. Ugwuoke

    2013-01-01

    Full Text Available In this paper, we use the correlation between the average wind speed and ambient temperature to develop models for predicting wind potentials for two Nigerian locations. Assuming that the troposphere is a typical heterogeneous mixture of ideal gases, we find that for the studied locations, wind speed clearly correlates with ambient temperature in a simple polynomial of 3rd degree. The coefficient of determination and root-mean-square error of the models are 0.81; 0.0024 and 0.56; 0.0041, respectively, for Enugu (6.40N; 7.50E and Owerri (5.50N; 7.00E. These results suggest that the temperature-based model can be used, with acceptable accuracy, in predicting wind potentials needed for preliminary design assessment of wind energy conversion devices for the locations and others with similar meteorological conditions.

  12. Modeling the potential area of occupancy at fine resolution may reduce uncertainty in species range estimates

    DEFF Research Database (Denmark)

    Jiménez-Alfaro, Borja; Draper, David; Nogues, David Bravo

    2012-01-01

    and maximum entropy modeling to assess whether different sampling (expert versus systematic surveys) may affect AOO estimates based on habitat suitability maps, and the differences between such measurements and traditional coarse-grid methods. Fine-scale models performed robustly and were not influenced...... by survey protocols, providing similar habitat suitability outputs with high spatial agreement. Model-based estimates of potential AOO were significantly smaller than AOO measures obtained from coarse-scale grids, even if the first were obtained from conservative thresholds based on the Minimal Predicted...... Area (MPA). As defined here, the potential AOO provides spatially-explicit measures of species ranges which are permanent in the time and scarcely affected by sampling bias. The overestimation of these measures may be reduced using higher thresholds of habitat suitability, but standard rules as the MPA...

  13. Proton Spectroscopic Factors Deduced from Helium-3 Global Phenomenological and Microscopic Optical Model Potentials

    Science.gov (United States)

    Jenny, Lee; Pang, Dan-Yang; Han, Yin-Lu; B. Tsang, M.

    2014-09-01

    Global phenomenological GDP08 and microscopic helium-3 optical model potentials have been recently derived. We evaluate these two potential sets by comparing the elastic scattering data of 25 MeV 3He on 16O, 18O, 19F, 23Na, 24Mg, 25Mg, 26Mg, 27Al, 28Si, 30Si, 31P, 32S, 34S, 35Cl, 37Cl, and 39K isotopes. Using the deuteron angular distributions calculated with the distorted wave Born approximation model, we extract the ground-state proton spectroscopic factors from (3He, d) reactions on the same set of nuclei. The extracted proton spectroscopic factors are compared with the large-basis shell-model calculations.

  14. The high density region of QCD in a large mass and chemical potential model

    CERN Document Server

    De Pietri, R; Seiler, E; Stamatescu, I O; Pietri, Roberto De; Feo, Alessandra; Seiler, Erhard; Stamatescu, Ion-Olimpiu

    2005-01-01

    We study the high density region of QCD within an effective model obtained in the frame of the hopping parameter expansion. The model still acknowledges the sign problem peculiar to non-zero chemical potential, but it permits the development of refined algorithms which ensure a good overlap of the Monte Carlo ensemble with the true one. We review the main features of the model, including the most explicit form of the resumed expansion, and present calculations concerning the dependence of various observables on the chemical potential and on the temperature, in particular of the charge density and the diquark susceptibility, which may be used to characterize the various phases expected at high baryonic density.

  15. An asymmetric dimer in a periodic potential: a minimal model for friction of graphene flakes

    Science.gov (United States)

    Hens, Remco; Fasolino, Annalisa

    2016-07-01

    We discuss the friction and motion of a model of a dimer with asymmetric interactions with a substrate potential. Starting from the consideration that a rigid dimer with spacing equal to half of the period of the potential has exactly zero static friction like the infinite incommensurate Frenkel Kontorova model, we show how stick-slip behaviour and friction arise as a function of asymmetry. We argue that this model can yield a simple yet insightful description of the frictional behaviour of graphene flakes on graphite and of superlubricity. The results can also be of interest for diatomic molecules on surfaces. Supplementary material in the form of three mp4 files available from the Journal web page at http://dx.doi.org/10.1140/epjb/e2016-70273-5

  16. Empirical models for predicting wind potential for wind energy applications in rural locations of Nigeria

    Energy Technology Data Exchange (ETDEWEB)

    Odo, F.C. [National Centre for Energy Research and Development, University of Nigeria, Nsukka (Nigeria); Department of Physics and Astronomy, University of Nigeria, Nsukka (Nigeria); Akubue, G.U.; Offiah, S.U.; Ugwuoke, P.E. [National Centre for Energy Research and Development, University of Nigeria, Nsukka (Nigeria)

    2013-07-01

    In this paper, we use the correlation between the average wind speed and ambient temperature to develop models for predicting wind potentials for two Nigerian locations. Assuming that the troposphere is a typical heterogeneous mixture of ideal gases, we find that for the studied locations, wind speed clearly correlates with ambient temperature in a simple polynomial of 3rd degree. The coefficient of determination and root-mean-square error of the models are 0.81; 0.0024 and 0.56; 0.0041, respectively, for Enugu (6.40N; 7.50E) and Owerri (5.50N; 7.00E). These results suggest that the temperature-based model can be used, with acceptable accuracy, in predicting wind potentials needed for preliminary design assessment of wind energy conversion devices for the locations and others with similar meteorological conditions.

  17. Influenza Illness among Case-Patients Hospitalized for Suspected Dengue, El Salvador, 2012.

    Science.gov (United States)

    Chacon, Rafael; Clara, Alexey Wilfrido; Jara, Jorge; Armero, Julio; Lozano, Celina; El Omeiri, Nathalie; Widdowson, Marc-Alain; Azziz-Baumgartner, Eduardo

    2015-01-01

    We estimate the proportion of patients hospitalized for suspected dengue that tested positive for influenza virus in El Salvador during the 2012 influenza season. We tested specimens from 321 hospitalized patients: 198 patients with SARI and 123 patients with suspected dengue. Among 121 hospitalized suspected dengue (two co-infected excluded) patients, 28% tested positive for dengue and 19% positive for influenza; among 35 with suspected dengue and respiratory symptoms, 14% were positive for dengue and 39% positive for influenza. One percent presented co-infection between influenza and dengue. Clinicians should consider the diagnosis of influenza among patients with suspected dengue during the influenza season.

  18. Modelization of the Current and Future Habitat Suitability of Rhododendron ferrugineum Using Potential Snow Accumulation.

    Directory of Open Access Journals (Sweden)

    Benjamin Komac

    Full Text Available Mountain areas are particularly sensitive to climate change. Species distribution models predict important extinctions in these areas whose magnitude will depend on a number of different factors. Here we examine the possible impact of climate change on the Rhododendron ferrugineum (alpenrose niche in Andorra (Pyrenees. This species currently occupies 14.6 km2 of this country and relies on the protection afforded by snow cover in winter. We used high-resolution climatic data, potential snow accumulation and a combined forecasting method to obtain the realized niche model of this species. Subsequently, we used data from the high-resolution Scampei project climate change projection for the A2, A1B and B1 scenarios to model its future realized niche model. The modelization performed well when predicting the species's distribution, which improved when we considered the potential snow accumulation, the most important variable influencing its distribution. We thus obtained a potential extent of about 70.7 km(2 or 15.1% of the country. We observed an elevation lag distribution between the current and potential distribution of the species, probably due to its slow colonization rate and the small-scale survey of seedlings. Under the three climatic scenarios, the realized niche model of the species will be reduced by 37.9-70.1 km(2 by the end of the century and it will become confined to what are today screes and rocky hillside habitats. The particular effects of climate change on seedling establishment, as well as on the species' plasticity and sensitivity in the event of a reduction of the snow cover, could worsen these predictions.

  19. Modelization of the Current and Future Habitat Suitability of Rhododendron ferrugineum Using Potential Snow Accumulation

    Science.gov (United States)

    Komac, Benjamin; Esteban, Pere; Trapero, Laura; Caritg, Roger

    2016-01-01

    Mountain areas are particularly sensitive to climate change. Species distribution models predict important extinctions in these areas whose magnitude will depend on a number of different factors. Here we examine the possible impact of climate change on the Rhododendron ferrugineum (alpenrose) niche in Andorra (Pyrenees). This species currently occupies 14.6 km2 of this country and relies on the protection afforded by snow cover in winter. We used high-resolution climatic data, potential snow accumulation and a combined forecasting method to obtain the realized niche model of this species. Subsequently, we used data from the high-resolution Scampei project climate change projection for the A2, A1B and B1 scenarios to model its future realized niche model. The modelization performed well when predicting the species’s distribution, which improved when we considered the potential snow accumulation, the most important variable influencing its distribution. We thus obtained a potential extent of about 70.7 km2 or 15.1% of the country. We observed an elevation lag distribution between the current and potential distribution of the species, probably due to its slow colonization rate and the small-scale survey of seedlings. Under the three climatic scenarios, the realized niche model of the species will be reduced by 37.9–70.1 km2 by the end of the century and it will become confined to what are today screes and rocky hillside habitats. The particular effects of climate change on seedling establishment, as well as on the species’ plasticity and sensitivity in the event of a reduction of the snow cover, could worsen these predictions. PMID:26824847

  20. Bacterial colonization of the ovarian bursa in dogs with clinically suspected pyometra and in controls.

    Science.gov (United States)

    Rubio, Alejandro; Boyen, Filip; Tas, Olaf; Kitshoff, Adriaan; Polis, Ingeborgh; Van Goethem, Bart; de Rooster, Hilde

    2014-10-15

    Septic peritonitis occurs relatively commonly in dogs. Secondary septic peritonitis is usually associated with perforation of intestines or infected viscera, such as the uterus in pyometra cases. The aim of this study was to evaluate the bacterial flora in the ovarian bursae of intact bitches as a potential source of contamination. One hundred forty dogs, clinically suspected of pyometra, were prospectively enrolled. The control group consisted of 26 dogs that underwent elective ovariohysterectomies and 18 dogs with mammary gland tumors that were neutered at the time of mastectomy. Bacteriology samples were taken aseptically at the time of surgery from the bursae and the uterus in all dogs. Twenty-two dogs that were clinically suspected of pyometra had sterile uterine content ("mucometra" cases); the remaining 118 had positive uterine cultures ("pyometra" cases) and septic peritoneal fluid was present in 10% of these cases. Of the 118 pyometra cases, 9 had unilateral and 15 had bilateral bacterial colonization of their ovarian bursae. However, the bacteria from the ovarian bursa were similar to those recovered from the uterine pus in only half of the cases. Furthermore, positive bursae were also seen in one mucometra dog (unilateral) and in four control dogs (two unilateral and two bilateral). The data illustrate that the canine ovarian bursa can harbor bacteria. The biological importance of these isolations remains unclear. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Creutzfeldt-Jakob disease (CJD) in a case of suspected chronic heavy metal poisoning.

    Science.gov (United States)

    Oehmichen, M; Schulz-Schaeffer, W; Kretzschmar, H; Theuerkauf, I; Gerling, I; Windl, O; Meissner, C

    2001-05-01

    We describe a patient who died of suspected heavy metal poisoning after a nine-month history of rapidly worsening dementia. Autopsy at a forensic-pathological institute established the postmortem diagnosis of sporadic Creutzfeldt-Jakob disease (CJD) based on demonstration of the proteinase-resistant prion protein (PrPsSc) in Western-Blot on native brain tissue. Microscopic examination of the macroscopically largely inconspicuous brain revealed marked spongiform changes in the gray matter--mainly affecting the cerebral cortex, nucleus caudatus, and putamen--with confluent vacuoles. Patchy or perivacuolar deposits of PrPSc were found as well as granular PrPsc deposits. The cerebellum contained focal PrPsc deposits. There was an astrogliosis in the white matter and a proliferation of microglia in the gray matter with a simultaneous clear reduction in neuronal elements. The differential diagnosis is discussed, as is the potential risk to those performing autopsy on forensic cases with a clinical picture of rapidly progressing dementia, especially in cases where a prion disease is not initially suspected.

  2. Spatial Distance Regulates Sex-Specific Feelings to Suspected Sexual and Emotional Infidelity

    Directory of Open Access Journals (Sweden)

    Achim Schützwohl

    2011-07-01

    Full Text Available The present study investigates the hitherto neglected influence of the spatial distance between the jealous person, the partner, and a potential rival as a proximate contextual factor regulating emotion intensity. The study tested four predictions. (1 The jealousy mechanism responds with mild negative feelings at most as long as the partner is close to the jealous person. (2 The negative feelings increase when the partner is far from the jealous person but the rival is close. (3 The most uncomfortable feelings result when the partner and the rival are close together and both far from the jealous person. (4 Based on the evolutionary psychological considerations, men report stronger negative feelings than women when suspecting sexual infidelity. Conversely, women report stronger negative feelings than men when suspecting emotional infidelity. The results confirmed predictions 1 and 4. Reversing predictions 2 and 3, the close rival consistently elicited the most uncomfortable feelings. Implications and limitations of the present study are discussed and suggestions for future research are provided.

  3. Contact Angle Adjustment in Equation of States Based Pseudo-Potential Model

    CERN Document Server

    Hu, Anjie; Uddin, Rizwan

    2015-01-01

    Single component pseudo-potential lattice Boltzmann model has been widely applied in multiphase simulation due to its simplicity and stability. In many research, it has been claimed that this model can be stable for density ratios larger than 1000, however, the application of the model is still limited to small density ratios when the contact angle is considered. The reason is that the original contact angle adjustment method influences the stability of the model. Moreover, simulation results in present work show that, by applying the contact angle adjustment method, the density distribution near the wall is artificially changed, and the contact angle is dependent on the surface tension. Hence, it is very inconvenient to apply this method with a fixed contact angle, and the accuracy of the model cannot be guaranteed. To solve these problems, a contact angle adjustment method based on the geometry analysis is proposed and numerically compared with the original method. Simulation results show that, with the new...

  4. Metastatic human hepatocellular carcinoma models in nude mice and cell line with metastatic potential

    Institute of Scientific and Technical Information of China (English)

    Zhao-You Tang; Lun-Xiu Qin; Hui-Chuan Sun; Lu Wang; Jian Zhou; Yah Li; Zeng-Chen Ma; Xin-Da Zhou; Zhi-Quan Wu; Zhi-Ying Lin; Bing-Hui Yang; Fan-Xian Sun; Jian Tian; Sheng-Long Ye; Yin-Kun Liu; Kang-Da Liu; Qiong Xue; Jie Chen; Jing-Lin Xia

    2001-01-01

    Metastatic human HCC model is needed for the studies on mechanism and intervention of metastatic recurrence. By using orthotopic implantation of histologically intact tissues of 30 surgical specimens, a patient like metastatic model of human HCC in nude mice (LCI-D20)and a Iow metastatic model of human HCC in nude mice LCI-D35 ) have been established. All mice with transplanted LCI-D20 tumors exhibited extremely high metastatic ability including spontaneous metastasis to liver, lungs, lymph nodes and peritoneal seeding.Remarkable difference was also found in expression of some of the invasiveness related genes and growth factors between the LCI-D20 and LCI-D35 tumors. PAI-Iincreased gradually following tumor progression in LCID20 model, and correlated with tumor size and AFP level,Phasic expression of tissue intercellular adhesion molecule-I in this model was also observed. Using corneal micropocket model, it was demonstrated that the vascular response induced by LCI-D20 tumor was stronger than that induced by LCI-D35 tumor. Similar report on metastatic human HCC model in nude mice and human HCC cell line with metastatic potential was rarely found in the literature. This LCI-D20 model has been widely used for the studies on intervention of metastasis, including antiangiogenesis, antisense approach, metalloproteinase inhibitor, differentiation inducer, etc. It is concluded that the establishment of metastatic human HCC model in nude mice and human HCC cell line with metastatic potential will provide important models for the in vivo and in vitro study of HCC invasiveness, angiogenesis as well as intervention of HCC recurrence.``

  5. Vibrational dynamics of the bifluoride ion. I. Construction of a model potential surface

    Science.gov (United States)

    Epa, V. C.; Choi, J. H.; Klobukowski, M.; Thorson, W. R.

    1990-01-01

    Construction of an extended model potential surface for the bifluoride ion [FHF-] is described, based on ab initio calculations for the free ion at the CID (configuration interaction, double replacement) level with a Huzinaga-Dunning double-zeta basis set. 710 data points were generated, for displacements in the three noncyclic vibrational coordinates exploring the potential surface to a height at least 30 000 cm-1 above its minimum, and giving a realistic account of the dissociation into HF+F-. Analogous calculations were made for HF and F- using the same basis. The predicted hydrogen bond energy (De) is 48.13 kcal/mol, with equilibrium F-F separation Re =4.2905 a.u., in good agreement with other recent calculations. A model potential has been constructed, based on a superposition of Morse potentials associated with each H-F distance plus a fairly structureless correction function expressible as a 36-term least-squares polynomial in the prolate spheroidal coordinates used to describe vibrational displacements. The resulting model surface fits all 710 ab initio data points with an r.m.s. deviation of 65.6 cm-1, and points less than 15 000 cm-1 above the minimum with a deviation of 26.3 cm-1. This surface provides the basis for a series of vibrational dynamics studies on the FHF- system being done in this laboratory.

  6. Electrical coupling in ensembles of nonexcitable cells: modeling the spatial map of single cell potentials.

    Science.gov (United States)

    Cervera, Javier; Manzanares, Jose Antonio; Mafe, Salvador

    2015-02-19

    We analyze the coupling of model nonexcitable (non-neural) cells assuming that the cell membrane potential is the basic individual property. We obtain this potential on the basis of the inward and outward rectifying voltage-gated channels characteristic of cell membranes. We concentrate on the electrical coupling of a cell ensemble rather than on the biochemical and mechanical characteristics of the individual cells, obtain the map of single cell potentials using simple assumptions, and suggest procedures to collectively modify this spatial map. The response of the cell ensemble to an external perturbation and the consequences of cell isolation, heterogeneity, and ensemble size are also analyzed. The results suggest that simple coupling mechanisms can be significant for the biophysical chemistry of model biomolecular ensembles. In particular, the spatiotemporal map of single cell potentials should be relevant for the uptake and distribution of charged nanoparticles over model cell ensembles and the collective properties of droplet networks incorporating protein ion channels inserted in lipid bilayers.

  7. Assessing potential health impacts of waste recovery and reuse business models in Hanoi, Vietnam.

    Science.gov (United States)

    Winkler, Mirko S; Fuhrimann, Samuel; Pham-Duc, Phuc; Cissé, Guéladio; Utzinger, Jürg; Nguyen-Viet, Hung

    2017-02-01

    In resource-constrained settings, the recovery of nutrients and the production of energy from liquid and solid waste are important. We determined the range and magnitude of potential community health impacts of six solid and liquid waste recovery and reuse business models in Hanoi, Vietnam. We employed a health impact assessment (HIA) approach using secondary data obtained from various sources supplemented with primary data collection. For determining the direction (positive or negative) and magnitude of potential health impacts in the population, a semiquantitative impact assessment was pursued. From a public health perspective, wastewater reuse for inland fish farming, coupled with on-site water treatment has considerable potential for individual and community-level health benefits. One of the business models investigated (i.e. dry fuel manufacturing with agro-waste) resulted in net negative health impacts. In Hanoi, the reuse of liquid and solid waste-as a mean to recover water and nutrients and to produce energy-has considerable potential for health benefits if appropriately managed and tailored to local contexts. Our HIA methodology provides an evidence-based decision-support tool for identification and promotion of business models for implementation in Hanoi.

  8. Nuclear mean field and double-folding model of the nucleus-nucleus optical potential

    CERN Document Server

    Khoa, Dao T; Loan, Doan Thi; Loc, Bui Minh

    2016-01-01

    Realistic density dependent CDM3Yn versions of the M3Y interaction have been used in an extended Hartree-Fock (HF) calculation of nuclear matter (NM), with the nucleon single-particle potential determined from the total NM energy based on the Hugenholtz-van Hove theorem that gives rise naturally to a rearrangement term (RT). Using the RT of the single-nucleon potential obtained exactly at different NM densities, the density- and energy dependence of the CDM3Yn interactions was modified to account properly for both the RT and observed energy dependence of the nucleon optical potential. Based on a local density approximation, the double-folding model of the nucleus-nucleus optical potential has been extended to take into account consistently the rearrangement effect and energy dependence of the nuclear mean-field potential, using the modified CDM3Yn interactions. The extended double-folding model was applied to study the elastic $^{12}$C+$^{12}$C and $^{16}$O+$^{12}$C scattering at the refractive energies, wher...

  9. Singular-potential random-matrix model arising in mean-field glassy systems.

    Science.gov (United States)

    Akemann, Gernot; Villamaina, Dario; Vivo, Pierpaolo

    2014-06-01

    We consider an invariant random matrix ensemble where the standard Gaussian potential is distorted by an additional single pole of arbitrary fixed order. Potentials with first- and second-order poles have been considered previously and found applications in quantum chaos and number theory. Here we present an application to mean-field glassy systems. We derive and solve the loop equation in the planar limit for the corresponding class of potentials. We find that the resulting mean or macroscopic spectral density is generally supported on two disconnected intervals lying on the two sides of the repulsive pole, whose edge points can be completely determined imposing the additional constraint of traceless matrices on average. For an unbounded potential with an attractive pole, we also find a possible one-cut solution for certain values of the couplings, which is ruled out when the traceless condition is imposed. Motivated by the calculation of the distribution of the spin-glass susceptibility in the Sherrington-Kirkpatrick spin-glass model, we consider in detail a second-order pole for a zero-trace model and provide the most explicit solution in this case. In the limit of a vanishing pole, we recover the standard semicircle. Working in the planar limit, our results apply to matrices with orthogonal, unitary, and symplectic invariance. Numerical simulations and an independent analytical Coulomb fluid calculation for symmetric potentials provide an excellent confirmation of our results.

  10. [Prediction of potential distribution area of Erigeron philadelphicus in China based on MaxEnt model].

    Science.gov (United States)

    Zhang, Ying; Li, Jun; Lin, Wei; Qiang, Sheng

    2011-11-01

    Erigeron philadelphicus, an alien weed originated from North America, has already invaded in Shanghai, Jiangsu, Anhui, and some other places in China, caused harm on local ecosystem and demonstrated huge potential invasiveness. By using MaxEnt model and geographic information system (GIS), this paper analyzed the environmental variables affecting the distribution of E. philadelphicus, and intuitively and quantitatively predicted its potential distribution regions in China. The prediction was verified by the ROC curve, and the results showed that E. philadelphicus had a wide potential distribution range, with the main suitable distribution area in Shanghai, Jiangsu, Zhejiang, Anhui, Henan, Hubei, Hunan and Jiangxi. At present, the actual invasive range of E. philadelphicus was far narrower than its potential maximum invasive range, and likely to be continued to spread. The ROC curve test indicated that the prediction with MaxEnt model had a higher precision, and was credible. Air temperature and precipitation could be the main environmental variables affecting the potential distribution of E. philadelphicus. More attentions should be addressed to the harmfulness of the weed. To eradicate the existing E. philadelphicus populations and to strictly monitor the invasion of E. philadelphicus to its most suitable distribution area could be the effective measures to prevent and control the further invasion of the alien weed.

  11. Resistor mesh model of a spherical head: part 1: applications to scalp potential interpolation.

    Science.gov (United States)

    Chauveau, N; Morucci, J P; Franceries, X; Celsis, P; Rigaud, B

    2005-11-01

    A resistor mesh model (RMM) has been implemented to describe the electrical properties of the head and the configuration of the intracerebral current sources by simulation of forward and inverse problems in electroencephalogram/event related potential (EEG/ERP) studies. For this study, the RMM representing the three basic tissues of the human head (brain, skull and scalp) was superimposed on a spherical volume mimicking the head volume: it included 43 102 resistances and 14 123 nodes. The validation was performed with reference to the analytical model by consideration of a set of four dipoles close to the cortex. Using the RMM and the chosen dipoles, four distinct families of interpolation technique (nearest neighbour, polynomial, splines and lead fields) were tested and compared so that the scalp potentials could be recovered from the electrode potentials. The 3D spline interpolation and the inverse forward technique (IFT) gave the best results. The IFT is very easy to use when the lead-field matrix between scalp electrodes and cortex nodes has been calculated. By simple application of the Moore-Penrose pseudo inverse matrix to the electrode cap potentials, a set of current sources on the cortex is obtained. Then, the forward problem using these cortex sources renders all the scalp potentials.

  12. Singular-potential random-matrix model arising in mean-field glassy systems

    Science.gov (United States)

    Akemann, Gernot; Villamaina, Dario; Vivo, Pierpaolo

    2014-06-01

    We consider an invariant random matrix ensemble where the standard Gaussian potential is distorted by an additional single pole of arbitrary fixed order. Potentials with first- and second-order poles have been considered previously and found applications in quantum chaos and number theory. Here we present an application to mean-field glassy systems. We derive and solve the loop equation in the planar limit for the corresponding class of potentials. We find that the resulting mean or macroscopic spectral density is generally supported on two disconnected intervals lying on the two sides of the repulsive pole, whose edge points can be completely determined imposing the additional constraint of traceless matrices on average. For an unbounded potential with an attractive pole, we also find a possible one-cut solution for certain values of the couplings, which is ruled out when the traceless condition is imposed. Motivated by the calculation of the distribution of the spin-glass susceptibility in the Sherrington-Kirkpatrick spin-glass model, we consider in detail a second-order pole for a zero-trace model and provide the most explicit solution in this case. In the limit of a vanishing pole, we recover the standard semicircle. Working in the planar limit, our results apply to matrices with orthogonal, unitary, and symplectic invariance. Numerical simulations and an independent analytical Coulomb fluid calculation for symmetric potentials provide an excellent confirmation of our results.

  13. Geographical Information System Model for Potential Mines Data Management Presentation in Kabupaten Gorontalo

    Science.gov (United States)

    Roviana, D.; Tajuddin, A.; Edi, S.

    2017-03-01

    Mining potential in Indonesian is very abundant, ranging from Sabang to Marauke. Kabupaten Gorontalo is one of many places in Indonesia that have different types of minerals and natural resources that can be found in every district. The abundant of mining potential must be balanced with good management and ease of getting information by investors. The current issue is, (1) ways of presenting data/information about potential mines area is still manually (the maps that already capture from satellite image, then printed and attached to information board in the office) it caused the difficulties of getting information; (2) the high cost of maps printing; (3) the difficulties of regency leader (bupati) to obtain information for strategic decision making about mining potential. The goal of this research is to build a model of Geographical Information System that could provide data management of potential mines, so that the investors could easily get information according to their needs. To achieve that goal Research and Development method is used. The result of this research, is a model of Geographical Information System that implemented in an application to presenting data management of mines.

  14. The potential of chitosan in enhancing peptide and protein absorption across the TR146 cell culture model-an in vitro model of the buccal epithelium

    DEFF Research Database (Denmark)

    Portero, Ana; Remuñán-López, Carmen; Nielsen, Hanne Mørck

    2002-01-01

    To investigate the potential of chitosan (CS) to enhance buccal peptide and protein absorption, the TR146 cell culture model, a model of the buccal epithelium, was used.......To investigate the potential of chitosan (CS) to enhance buccal peptide and protein absorption, the TR146 cell culture model, a model of the buccal epithelium, was used....

  15. Parameter-free one-center model potential for an effective one-electron description of molecular hydrogen

    DEFF Research Database (Denmark)

    Lühr, Armin Christian; Vanne, Yulian; Saenz, Alejandro

    2008-01-01

    For the description of an H2 molecule, an effective one-electron model potential is proposed which is fully determined by the exact ionization potential of the H2 molecule. In order to test the model potential and examine its properties, it is employed to determine excitation energies, transition...

  16. Grid-based precision aim system and method for disrupting suspect objects

    Science.gov (United States)

    Gladwell, Thomas Scott; Garretson, Justin; Hobart, Clinton G.; Monda, Mark J.

    2014-06-10

    A system and method for disrupting at least one component of a suspect object is provided. The system has a source for passing radiation through the suspect object, a grid board positionable adjacent the suspect object (the grid board having a plurality of grid areas, the radiation from the source passing through the grid board), a screen for receiving the radiation passing through the suspect object and generating at least one image, a weapon for deploying a discharge, and a targeting unit for displaying the image of the suspect object and aiming the weapon according to a disruption point on the displayed image and deploying the discharge into the suspect object to disable the suspect object.

  17. Parameter estimation in neuronal stochastic differential equation models from intracellular recordings of membrane potentials in single neurons

    DEFF Research Database (Denmark)

    Ditlevsen, Susanne; Samson, Adeline

    2016-01-01

    Dynamics of the membrane potential in a single neuron can be studied by estimating biophysical parameters from intracellular recordings. Diffusion processes, given as continuous solutions to stochastic differential equations, are widely applied as models for the neuronal membrane potential...... evolution. One-dimensional models are the stochastic integrate-and-fire neuronal diffusion models. Biophysical neuronal models take into account the dynamics of ion channels or synaptic activity, leading to multidimensional diffusion models. Since only the membrane potential can be measured......, this complicates the statistical inference and parameter estimation from these partially observed detailed models. This paper reviews parameter estimation techniques from intracellular recordings in these diffusion models....

  18. The impact of surface area, volume, curvature, and Lennard-Jones potential to solvation modeling.

    Science.gov (United States)

    Nguyen, Duc D; Wei, Guo-Wei

    2017-01-05

    This article explores the impact of surface area, volume, curvature, and Lennard-Jones (LJ) potential on solvation free energy predictions. Rigidity surfaces are utilized to generate robust analytical expressions for maximum, minimum, mean, and Gaussian curvatures of solvent-solute interfaces, and define a generalized Poisson-Boltzmann (GPB) equation with a smooth dielectric profile. Extensive correlation analysis is performed to examine the linear dependence of surface area, surface enclosed volume, maximum curvature, minimum curvature, mean curvature, and Gaussian curvature for solvation modeling. It is found that surface area and surfaces enclosed volumes are highly correlated to each other's, and poorly correlated to various curvatures for six test sets of molecules. Different curvatures are weakly correlated to each other for six test sets of molecules, but are strongly correlated to each other within each test set of molecules. Based on correlation analysis, we construct twenty six nontrivial nonpolar solvation models. Our numerical results reveal that the LJ potential plays a vital role in nonpolar solvation modeling, especially for molecules involving strong van der Waals interactions. It is found that curvatures are at least as important as surface area or surface enclosed volume in nonpolar solvation modeling. In conjugation with the GPB model, various curvature-based nonpolar solvation models are shown to offer some of the best solvation free energy predictions for a wide range of test sets. For example, root mean square errors from a model constituting surface area, volume, mean curvature, and LJ potential are less than 0.42 kcal/mol for all test sets. © 2016 Wiley Periodicals, Inc.

  19. Modeling Potential Surface and Shallow Groundwater Storage Provided by Beaver Ponds Across Watersheds

    Science.gov (United States)

    Hafen, K.; Wheaton, J. M.; Macfarlane, W.

    2016-12-01

    Damming of streams by North American Beaver (Castor canadensis) has been shown to provide a host of potentially desirable hydraulic and hydrologic impacts. Notably, increases in surface water storage and groundwater storage may alter the timing and delivery of water around individual dams and dam complexes. Anecdotal evidence suggests these changes may be important for increasing and maintaining baseflow and even helping some intermittent streams flow perennially. In the arid west, these impacts could be particularly salient in the face of climate change. However, few studies have examined the hydrologic impacts of beaver dams at scales large enough to provide insight for water management, in part because understanding or modeling these impacts at large spatial scales has been precluded by uncertainty concerning the number of beaver dams a drainage network can support. Using the recently developed Beaver Restoration Assessment Tool (BRAT) to identify possible densities and spatial configurations of beaver dams, we developed a model that predicts the area and volume of surface water storage associated with dams of various sizes, and applied this model at different dam densities across multiple watersheds (HUC12) in northern Utah. We then used model results as inputs to the MODFLOW groundwater model to identify the subsequent changes to shallow groundwater storage. The spatially explicit water storage estimates produced by our approach will be useful in evaluating potential beaver restoration and conservation, and will also provide necessary information for developing hydrologic models to specifically identify the effects beaver dams may have on water delivery and timing.

  20. a Plugin to Interface Openmodeller from Qgis for SPECIES' Potential Distribution Modelling

    Science.gov (United States)

    Becker, Daniel; Willmes, Christian; Bareth, Georg; Weniger, Gerd-Christian

    2016-06-01

    This contribution describes the development of a plugin for the geographic information system QGIS to interface the openModeller software package. The aim is to use openModeller to generate species' potential distribution models for various archaeological applications (site catchment analysis, for example). Since the usage of openModeller's command-line interface and configuration files can be a bit inconvenient, an extension of the QGIS user interface to handle these tasks, in combination with the management of the geographic data, was required. The implementation was realized in Python using PyQGIS and PyQT. The plugin, in combination with QGIS, handles the tasks of managing geographical data, data conversion, generation of configuration files required by openModeller and compilation of a project folder. The plugin proved to be very helpful with the task of compiling project datasets and configuration files for multiple instances of species occurrence datasets and the overall handling of openModeller. In addition, the plugin is easily extensible to take potential new requirements into account in the future.

  1. Sensitivity analysis of CLIMEX parameters in modeling potential distribution of Phoenix dactylifera L.

    Directory of Open Access Journals (Sweden)

    Farzin Shabani

    Full Text Available Using CLIMEX and the Taguchi Method, a process-based niche model was developed to estimate potential distributions of Phoenix dactylifera L. (date palm, an economically important crop in many counties. Development of the model was based on both its native and invasive distribution and validation was carried out in terms of its extensive distribution in Iran. To identify model parameters having greatest influence on distribution of date palm, a sensitivity analysis was carried out. Changes in suitability were established by mapping of regions where the estimated distribution changed with parameter alterations. This facilitated the assessment of certain areas in Iran where parameter modifications impacted the most, particularly in relation to suitable and highly suitable locations. Parameter sensitivities were also evaluated by the calculation of area changes within the suitable and highly suitable categories. The low temperature limit (DV2, high temperature limit (DV3, upper optimal temperature (SM2 and high soil moisture limit (SM3 had the greatest impact on sensitivity, while other parameters showed relatively less sensitivity or were insensitive to change. For an accurate fit in species distribution models, highly sensitive parameters require more extensive research and data collection methods. Results of this study demonstrate a more cost effective method for developing date palm distribution models, an integral element in species management, and may prove useful for streamlining requirements for data collection in potential distribution modeling for other species as well.

  2. Hodges' Health Career Model and its role and potential application in forensic mental health nursing.

    Science.gov (United States)

    Doyle, M; Jones, P

    2013-09-01

    Forensic mental health nursing is increasingly recognized as a speciality of mental health nursing. Despite this, there are limited examples of theoretical models to underpin this specialism. This paper describes a conceptual framework known as the Hodges' Health Career - Care Domains - Model, hereafter referred to as the Health Career Model (HCM). Readers will learn of the model's origins, development, structure and content together with its application in forensic mental health nursing. Created in the 1980s, the model was developed in the North West of England by Brian E. Hodges. Overall, the purpose of the paper is to demonstrate the model's potential in forensic mental health nursing, its flexibility, adaptability and its increasing relevance to the problems of 21st century health, social care and well-being. Forensic nursing is discussed and the rationale for a nursing model is made. Hodges' model is introduced by explaining its original purposes, structure, its four knowledge (care) domains, its current status, publications and resources. The model's relevance and application in forensic nursing is explored, in particular the demands and unique constraints of this care environment as exercised upon service users, the multidisciplinary team, families, carers and other stakeholders. Future implications for research and recovery-orientated practice are discussed.

  3. Scalar O(N) Model at Finite Temperature -- 2PI Effective Potential in Different Approximations

    CERN Document Server

    Baacke, J; Baacke, Jurgen; Michalski, Stefan

    2004-01-01

    We calculate the two-particle irreducible (2PI) effective potential of the O(N) linear sigma model in 1+1 dimensions. The approximations we use are the next-to-leading order of a 1/N expansion (for arbitrary N) and a kind of "resummed loop approximation" for N=1. We show that the effective potential of the 1/N expansion is convex for N=4 and N=10 whereas it is not for the "loop" expansion and the case N=1 of the 1/N expansion.

  4. Cosmological model with fermion and tachyon fields interacting via Yukawa-type potential

    Science.gov (United States)

    Ribas, Marlos O.; Devecchi, Fernando P.; Kremer, Gilberto M.

    2016-02-01

    A model for the universe with tachyonic and fermionic fields interacting through a Yukawa-type potential is investigated. It is shown that the tachyonic field answers for the initial accelerated regime and for the subsequent decelerated regime so that it behaves as an inflaton at early times and as a matter field at intermediate times, while the fermionic field has the role of a dark energy constituent, since it leads to an accelerated regime at later times. The interaction between the fields via a Yukawa-type potential controls the duration of the decelerated era, since a stronger coupling makes a shorter decelerated period.

  5. The $\\mathbb{C}$P(2) Model at Non-Zero Chemical Potential

    CERN Document Server

    Evans, Wynne; Wiese, Uwe-Jens

    2016-01-01

    Recently the simulation of quantum field theories using man-made physical systems has become realistic. In this publication we present numerical results which support the use of quantum simulation experiments to study quantum field theories at non-zero chemical potential. We have numerically simulated the (1+1)-d $\\mathbb{C}$P(2) model, which shares several interesting features with QCD, namely asymptotic freedom, a dynamically generated mass gap and topological sectors, via dimensional reduction of a (2+1)-d microscopic theory of SU(3) quantum spins. Numerical results for the particle number density as a function of chemical potential are presented.

  6. Cosmological model with fermion and tachyon fields interacting via Yukawa-type potential

    CERN Document Server

    Ribas, Marlos O; Kremer, Gilberto M

    2016-01-01

    A model for the universe with tachyonic and fermionic fields interacting through a Yukawa-type potential is investigated. It is shown that the tachyonic field answers for the initial accelerated regime and for the subsequent decelerated regime so that it behaves as an inflaton at early times and as a matter field at intermediate times, while the fermionic field has the role of a dark energy constituent, since it leads to an accelerated regime at later times. The interaction between the fields via a Yukawa-type potential controls the duration of the decelerated era, since a stronger coupling makes a shorter decelerated period.

  7. Three-loop Standard Model effective potential at leading order in strong and top Yukawa couplings

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Stephen P. [Santa Barbara, KITP

    2014-01-08

    I find the three-loop contribution to the effective potential for the Standard Model Higgs field, in the approximation that the strong and top Yukawa couplings are large compared to all other couplings, using dimensional regularization with modified minimal subtraction. Checks follow from gauge invariance and renormalization group invariance. I also briefly comment on the special problems posed by Goldstone boson contributions to the effective potential, and on the numerical impact of the result on the relations between the Higgs vacuum expectation value, mass, and self-interaction coupling.

  8. Design of potentially active ligands for SH2 domains by molecular modeling methods

    Directory of Open Access Journals (Sweden)

    Hurmach V. V.

    2014-07-01

    Full Text Available Search for new chemical structures possessing specific biological activity is a complex problem that needs the use of the latest achievements of molecular modeling technologies. It is well known that SH2 domains play a major role in ontogenesis as intermediaries of specific protein-protein interactions. Aim. Developing an algorithm to investigate the properties of SH2 domain binding, search for new potential active compounds for the whole SH2 domains class. Methods. In this paper, we utilize a complex of computer modeling methods to create a generic set of potentially active compounds targeting universally at the whole class of SH2 domains. A cluster analysis of all available three-dimensional structures of SH2 domains was performed and general pharmacophore models were formulated. The models were used for virtual screening of collection of drug-like compounds provided by Enamine Ltd. Results. The design technique for library of potentially active compounds for SH2 domains class was proposed. Conclusions. The original algorithm of SH2 domains research with molecular docking method was developed. Using our algorithm, the active compounds for SH2 domains were found.

  9. An explicit surface-potential-based MOSFET model incorporating the quantum mechanical effects

    Science.gov (United States)

    Basu, Dipanjan; Dutta, Aloke K.

    2006-07-01

    An explicit surface-potential-based MOSFET model has been proposed in this work here, which takes into account the quantum mechanical effects that arise in deep-submicron MOSFETs. The coupled Schrödinger's and Poisson's equations have been solved by using a variational wave function approach, as proposed by Fang and Howard. The resulting surface potential model is analytical, technology mapped, and completely continuous over the entire range of operation. The surface potential and the inversion charge density calculated using the proposed model show good match with the results of the numerical simulations obtained from a self-consistent Schrödinger-Poisson solver for a wide range of substrate doping and oxide thickness. The simulated values of the drain current match closely with the experimental results published elsewhere. The device small-signal parameters, e.g., transconductance, output conductance, etc., pass the standard benchmark tests suggested by Suyama and Tsividis qualitatively, thereby validating the approach of the model presented.

  10. Hail potential in Europe based on a regional climate model hindcast

    Science.gov (United States)

    Mohr, S.; Kunz, M.; Geyer, B.

    2015-12-01

    Due to the local-scale nature of hail and a lack of appropriate observation systems, comprehensive, reliable, and consistent information about hail frequency and intensity in Europe is not available. To overcome this constraint, we developed a logistic hail model that quantifies the potential of the atmosphere to form hailstorms. The model is based on a combination of appropriate hail-relevant meteorological parameters. This paper presents the application of an adjusted version of the logistic model with the objective being to estimate the hail potential across Europe based on dynamically downscaled National Centers for Environmental Prediction/National Center for Atmospheric Research1 reanalysis over a long-term period of 60 years (1951-2010). The model output, in terms of the potential hail index (PHI), identified several hot spots that are well known from other observational studies. Time series of the PHI over the 60 year period show a high correlation at different sites across Europe and high annual and multiannual variability, but no overall trend.

  11. Regional gold potential mapping in Kelantan (Malaysia) using probabilistic based models and GIS

    Science.gov (United States)

    Yusoff, Suhaimizi; Pradhan, Biswajeet; Manap, Mohamad Abd; Shafri, Helmi Zulhaidi Mohd

    2015-06-01

    The aim of this study is to test and compare two probabilistic based models (frequency ratio and weightsof- evidence) with regard to regional gold potential mapping at Kelantan, Malaysia. Until now these models have not been used for the purpose of mapping gold potential areas in Malaysia. This study analyzed the spatial relationship between gold deposits and geological factors such as lithology, faults, geochemical and geophysical data in geographical information system (GIS) software. About eight (8) gold deposits and five (5) related factors are identified and quantified for their spatial relationships. Then, all factors were combined to generate a predictive gold potential map. The predictive maps were then validated by comparing them with known gold deposits using receiver operating characteristics (ROC) and "area under the curve" (AUC) graphs. The results of validation showed accuracies of 80% for the frequency ratio and 74% for the weightsof- evidence model, respectively. The results demonstrated the usefulness of frequency ratio and weights-of-evidence modeling techniques in mineral exploration work to discover unknown gold deposits in Kelantan, Malaysia.

  12. Using Internet Artifacts to Profile a Child Pornography Suspect

    Directory of Open Access Journals (Sweden)

    Marcus K. Rogers

    2014-03-01

    Full Text Available Digital evidence plays a crucial role in child pornography investigations. However, in the following case study, the authors argue that the behavioral analysis or “profiling” of digital evidence can also play a vital role in child pornography investigations. The following case study assessed the Internet Browsing History (Internet Explorer Bookmarks, Mozilla Bookmarks, and Mozilla History from a suspected child pornography user’s computer. The suspect in this case claimed to be conducting an ad hoc law enforcement investigation. After the URLs were classified (Neutral; Adult Porn; Child Porn; Adult Dating sites; Pictures from Social Networking Profiles; Chat Sessions; Bestiality; Data Cleaning; Gay Porn, the Internet history files were statistically analyzed to determine prevalence and trends in Internet browsing. First, a frequency analysis was used to determine a baseline of online behavior. Results showed 54% (n = 3205 of the URLs were classified as “neutral” and 38.8% (n = 2265 of the URLs were classified as a porn website. Only 10.8% of the URLs were classified as child pornography websites. However when the IE history file was analyzed by visit, or “hit,” count, the Pictures/Profiles (31.5% category had the highest visit count followed by Neutral (19.3%, Gay Porn (17%, and Child Porn (16.6%. When comparing the frequency of URLs to the Hit Count for each pornography type, it was noted that the accused was accessing gay porn, child porn, chat rooms, and picture profiles (i.e., from Facebook more often than adult porn and neutral websites. The authors concluded that the suspect in this case was in fact a child pornography user and not an ad hoc investigator, and the findings from the behavioral analysis were admitted as evidence in the sentencing hearing for this case. The authors believe this case study illustrates the ability to conduct a behavioral analysis of digital evidence. More work is required to further validate the

  13. Control of facies/potential on hydrocarbon accumulation:a geological model for Iacustrine rift basins

    Institute of Scientific and Technical Information of China (English)

    Chen Dongxia; Pang Xiongqi; Zhang Shanwen; Wang Yongshi; Zhang Jun

    2008-01-01

    The formation and distribution of hydrocarbon accumulations are jointly controlled by"stratigraphic facies"and"fluid potential",which can be abbreviated in"control of facies/potential on hydrocarbon accumulation".Facies and potential control the time-space distribution of hydrocarbon accumulation macroscopically and the petroliferous characteristics of hydrocarbon accumulation microscopically.Tectonic facies and sedimentary facies control the time-space distribution.Lithofacies and petrophysical facies control the petroliferous characteristics.Favorable facies and high porosity and permeability control hydrocarbon accumulation in the lacustrine rift basins in China.Fluid potential is represented by the work required,which comprises the work against gravity,pressure,interfacial energy and kinetic energy.Hydrocarbon migration and accumulation are controlled by the joint action of multiple driving forces,and are characterized by accumulation in the area of low potential.At the structural high,low geopotential energy caused by buoyancy control anticlinal reservoir.The formation of lithological oil pool is controlled by low interfacial energy caused by capillary force.Low compressive energy caused by overpressure and faulting activity control the formation of the faulted block reservoir.Low geopotential energy of the basin margin caused by buoyancy control stratigraphic reservoir.The statistics of a large number of oil reservoirs show that favorable facies and low potential control hydrocarbon accumulation in the rift basin.where over 85% of the discovered hydrocarbon accumulations are distributed in the trap with favorable facies and lOW potentials.The case study showed that the prediction of favorable areas by application of the near source-favorable facies-low potential accumulation model correlated well with over 90% of the discovered oil pools' distribution of the middle section of the third member of the Shahejie Formation in the Dongying Depression,Bohai Bay

  14. Development of Linear Irreversible Thermodynamic Model for Oxidation Reduction Potential in Environmental Microbial System

    Science.gov (United States)

    Cheng, Hong-Bang; Kumar, Mathava; Lin, Jih-Gaw

    2007-01-01

    Nernst equation has been directly used to formulate the oxidation reduction potential (ORP) of reversible thermodynamic conditions but applied to irreversible conditions after several assumptions and/or modifications. However, the assumptions are sometimes inappropriate in the quantification of ORP in nonequilibrium system. We propose a linear nonequilibrium thermodynamic model, called microbial related reduction and oxidation reaction (MIRROR Model No. 1) for the interpretation of ORP in biological process. The ORP was related to the affinities of catabolism and anabolism. The energy expenditure of catabolism and anabolism was directly proportional to overpotential (η), straight coefficient of electrode (LEE), and degree of coupling between catabolism and ORP electrode, respectively. Finally, the limitations of MIRROR Model No. 1 were discussed for expanding the applicability of the model. PMID:17496027

  15. Shielded attractive shell model again: resummed thermodynamic perturbation theory for central force potential

    Science.gov (United States)

    Reščič, J.; Kalyuzhnyi, Y. V.; Cummings, P. T.

    2016-10-01

    The approach developed earlier to describe the dimerizing shielded attractive shell (SAS) primitive model of chemical association due to Cummings and Stell is generalized and extended to include a description of a polymerizing SAS model. Our extension is based on the combination of the resummed thermodynamic perturbation theory for central force (RTPT-CF) associating potential and self consistent scheme, which takes into account the changes in the system free volume due to association. Theoretical results for thermodynamical properties of the model at different bonding length, density and temperature are compared against newly generated computer simulation results. The theory gives very accurate predictions for the model with bonding length L * from the range 0  <  L *  <  0.6 at all values of the density and temperature studied, including the limit of infinitely large temperature.

  16. Coronal structure analysis based on the potential field source surface modeling and total solar eclipse observation

    Science.gov (United States)

    Muhamad, Johan; Mumtahana, Farahhati; Sutastio, Heri; Imaduddin, Irfan; Putri, Gerhana P.

    2016-11-01

    We constructed global coronal magnetic fields of the Sun during the Total Solar Eclipse (TSE) 9 March 2016 by using Potential Field Source Surface (PFSS) model. Synoptic photospheric magnetogram data from Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO) was used as a boundary condition to extrapolate the coronal magnetic fields of the Sun. This extrapolated structure was analyzed by comparing the alignment of the fields from the model with coronal structure from the observation. We also used observational data of coronal structure during the total solar eclipse to know how well the model agree with the observation. As a result, we could identify several coronal streamers which were produced by the large closed loops in the lower regime of the corona. This result verified that the PFSS extrapolation can be used as a tool to model the inner corona with several constraints. We also discussed how the coronal structure can be used to deduce the phase of the solar cycle.

  17. Fractal Potential Flows as an Exact Model for Fully Developed Turbulence

    CERN Document Server

    Vass, József

    2013-01-01

    Fully Developed Turbulence (FDT) occurs at the infinite extreme of the Reynolds spectrum. It is a theoretical phenomenon which can only be approximated experimentally or computationally, and thus its precise properties are only hypothetical, though widely accepted. It is considered to be a chaotic yet steady flow field, with self-similar fractalline features. A number of approximate models exist, often exploiting this self-similarity. We hereby present the exact mathematical model of Fractal Potential Flows, and link it philosophically to the phenomenon of FDT, building on its experimental characteristics. The model hinges on the recursive iteration of a fluid dynamical transfer operator. We show the existence of its unique attractor in an appropriate function space - called the invariant flow - which will serve as our model for the FDT flow field. Its sink singularities are shown to form an IFS fractal, resolving Mandelbrot's Conjecture. Meanwhile we present an isometric isomorphism between flows and probabi...

  18. Modeling the potential effects of atrazine on aquatic communities in midwestern streams.

    Science.gov (United States)

    Bartell, Steven M; Brain, Richard A; Hendley, Paul; Nair, Shyam K

    2013-10-01

    The comprehensive aquatic systems model for atrazine (CASM(ATZ)) estimates the potential toxic effects of atrazine on populations of aquatic plants and consumers in a generic lower-order midwestern stream. The CASM(ATZ) simulates the daily production of 20 periphyton and 6 aquatic vascular plant species. The modeled consumer community consists of 17 functionally defined species of zooplankton, benthic invertebrates, bacteria, and fish. Daily values of population biomass (grams of carbon per square meter) are calculated as nonlinear functions of population bioenergetics, physical-chemical environmental parameters, grazing/predator-prey interactions, and population-specific direct and indirect responses to atrazine. The CASM(ATZ) uses Monte Carlo methods to characterize the implications of phenotypic variability, environmental variability, and uncertainty associated with atrazine toxicity data in estimating the potential impacts of time-varying atrazine exposures on population biomass and community structure. Comparisons of modeled biomass values for plants and consumers with published data indicate that the generic reference simulation realistically describes ecological production in lower-order midwestern streams. Probabilistic assessments were conducted using the CASM(ATZ) to evaluate potential modeled changes in plant community structure resulting from measured atrazine exposure profiles in 3 midwestern US streams representing watersheds highly vulnerable to runoff. Deviation in the median values of maximum 30-d average Steinhaus similarity index ranged from 0.09% to 2.52% from the reference simulation. The CASM(ATZ) could therefore be used for the purposes of risk assessment by comparison of site monitoring-based model output to a biologically relevant Steinhaus similarity index level of concern. Used as a generic screening technology or in site-specific applications, the CASM(AT) provides an effective, coherent, and transparent modeling framework for assessing

  19. Regional modeling of large wildfires under current and potential future climates in Colorado and Wyoming, USA

    Science.gov (United States)

    West, Amanda; Kumar, Sunil; Jarnevich, Catherine S.

    2016-01-01

    Regional analysis of large wildfire potential given climate change scenarios is crucial to understanding areas most at risk in the future, yet wildfire models are not often developed and tested at this spatial scale. We fit three historical climate suitability models for large wildfires (i.e. ≥ 400 ha) in Colorado andWyoming using topography and decadal climate averages corresponding to wildfire occurrence at the same temporal scale. The historical models classified points of known large wildfire occurrence with high accuracies. Using a novel approach in wildfire modeling, we applied the historical models to independent climate and wildfire datasets, and the resulting sensitivities were 0.75, 0.81, and 0.83 for Maxent, Generalized Linear, and Multivariate Adaptive Regression Splines, respectively. We projected the historic models into future climate space using data from 15 global circulation models and two representative concentration pathway scenarios. Maps from these geospatial analyses can be used to evaluate the changing spatial distribution of climate suitability of large wildfires in these states. April relative humidity was the most important covariate in all models, providing insight to the climate space of large wildfires in this region. These methods incorporate monthly and seasonal climate averages at a spatial resolution relevant to land management (i.e. 1 km2) and provide a tool that can be modified for other regions of North America, or adapted for other parts of the world.

  20. A new three-variable mathematical model of action potential propagation in cardiac tissue.

    Science.gov (United States)

    Fenton, Flavio; Karma, Alain

    1996-03-01

    Modeling the electrical activity of the heart, and the complex signaling patterns which underly dangerous arrhythmias such as tachycardia and fibrillation, requires a quantitative model of action potential (AP) propagation. At present, there exist detailed ionic models of the Hodgkin-Huxley form that accurately reproduce dynamical features of the AP at a single cell level (e.g. Luo-Rudy, 1994). However, such models are not computationally tractable to study propagation in two and three-dimensional tissues of many resistively coupled cells. At the other extreme, there exists generic models of excitable media, such as the well-known FitzHugh-Nagumo model, which are only qualitative and do not reproduce essential dynamical features of cardiac AP. A new three-variable model is introduced which bridges the gap between these two types of models. It reproduces quantitatively important `mesoscopic' dynamical properties which are specific to cardiac AP, namely restitution and dispersion. At the same time, it remains computationally tractable and makes it possible to study the effect of these properties on the initiation, dynamics, and stability of complex reentrant excitations in two and three dimensions. Preliminary numerical results of the effect of restitution and dispersion on two-dimensional reentry (i.e. spiral waves) are presented.

  1. Shape corrections to exchange-correlation potentials by gradient-regulated seamless connection of model potentials for inner and outer region

    Science.gov (United States)

    Grüning, M.; Gritsenko, O. V.; van Gisbergen, S. J. A.; Baerends, E. J.

    2001-01-01

    Shape corrections to the standard approximate Kohn-Sham exchange-correlation (xc) potentials are considered with the aim to improve the excitation energies (especially for higher excitations) calculated with time-dependent density functional perturbation theory. A scheme of gradient-regulated connection (GRAC) of inner to outer parts of a model potential is developed. Asymptotic corrections based either on the potential of Fermi and Amaldi or van Leeuwen and Baerends (LB) are seamlessly connected to the (shifted) xc potential of Becke and Perdew (BP) with the GRAC procedure, and are employed to calculate the vertical excitation energies of the prototype molecules N2, CO, CH2O, C2H4, C5NH5, C6H6, Li2, Na2, K2. The results are compared with those of the alternative interpolation scheme of Tozer and Handy as well as with the results of the potential obtained with the statistical averaging of (model) orbital potentials. Various asymptotically corrected potentials produce high quality excitation energies, which in quite a few cases approach the benchmark accuracy of 0.1 eV for the electronic spectra. Based on these results, the potential BP-GRAC-LB is proposed for molecular response calculations, which is a smooth potential and a genuine "local" density functional with an analytical representation.

  2. Anticipating potential biodiversity conflicts for future biofuel crops in South Africa: incorporating spatial filters with species distribution models

    CSIR Research Space (South Africa)

    Blanchard, R

    2014-04-01

    Full Text Available distribution models, land cover, land capability and various biodiversity conservation data to identify natural areas with (i) a potentially high risk of transformation for biofuel production and (ii) potential impact to biodiversity conservation areas...

  3. Strength training for a child with suspected developmental coordination disorder.

    Science.gov (United States)

    Menz, Stacy M; Hatten, Kristin; Grant-Beuttler, Marybeth

    2013-01-01

    Children with developmental coordination disorder (DCD) demonstrate difficulty with feedforward motor control and use varied compensatory strategies. To examine gross motor function changes following strength training in a child with motor control difficulties. A girl aged 6 years 11 months, with apraxia and hypotonia, and demonstrating motor delays consistent with DCD. Twenty-four strength training sessions were completed using a universal exercise unit. Postintervention scores significantly improved on the Bruininks-Oseretsky test of motor proficiency, second edition, and the Canadian occupational performance measure scores and raised the developmental coordination disorder questionnaire, revised 2007, scores above the range where DCD is suspected. Nonsignificant changes in strength were observed. Improved function and significant gains in manual coordination were observed following blocked practice of isolated, simple joint movements during strength training. Improved motor skills may be because of effective use of feedforward control and improved stabilization. Strength training does not rehearse skills using momentum, explaining nonsignificant changes in locomotor or locomotion areas.

  4. Use of budesonide Turbuhaler in young children suspected of asthma

    DEFF Research Database (Denmark)

    Bisgaard, H; Pedersen, S; Nikander, K

    1994-01-01

    The question addressed in this study was the ability of young children to use a dry-powder inhaler, Turbuhaler. One hundred and sixty five children suspected of asthma, equally distributed in one year age-groups from 6 months to 8 yrs, inhaled from a Pulmicort Turbuhaler, 200 micrograms budesonide......-dose-1, through a filter. The amount of drug trapped by the filter was used as a measure of drug released to the patient. None of the children had prior experience in the use of a Turbuhaler, but they were instructed carefully, together with their parents, in the clinic. The median dose released revealed...... an age-dependent increase, with a considerable scatter. Accordingly, the dose delivered could not be predicted in these young children. The limitation to effective use in young children appeared to be lack of sufficient co-operation, rather than physical limitations, as even some very young children...

  5. [Nasogastric tube syndrome suspected at the end of anesthesia].

    Science.gov (United States)

    Ohshima, Misako; Hori, Etsuyo; Suzuki, Akira; Katoh, Hiromi; Itagaki, Taiga; Adachi, Yushi; Doi, Matsuyuki; Sato, Shigehito

    2010-04-01

    The case of a patient who might have developed nasogastric tube syndrome at the end of anesthesia is presented. A 62-year-old woman was scheduled for a general anesthesia with fiberscopic oro-tracheal intubation because of a predicted difficult airway. After the smooth and gentle intubation without any trauma and injury, a nasogastric tube was inserted blindly. At the end of surgery, the anesthesiologists observed the pharyngeal tissue and found significant edema on the epiglottis and arytenoids. Extubation was cancelled and the patient was moved to an intensive care unit for respiratory management. On the next day, fiberscopic observation revealed a complete recovery and the endotracheal tube was removed without any difficulty. We strongly suspected the pharyngeal injury as acute nasogastric tube syndrome and an attention to this rare complication is required by anesthesiologists.

  6. Distemper in raccoons and foxes suspected of having rabies

    Science.gov (United States)

    Habermann, R.T.; Herman, C.M.; Williams, F.P.

    1958-01-01

    1) Twenty-one raccoons and 3 red foxes were collected from areas where suspected rabies occurred. All were found to be nonrabid. 2) Distemper was diagnosed in 14 of the 21 raccoons by demonstrating intracytoplasmic and intranuclear inclusions in the brain and visceral tissues. Two of the 3 foxes were considered to have distemper; the clinical signs were typical and mouse inoculation tests were negative for rabies. 3) Deaths of the other 7 raccoons were attributed to: leishmaniasis 1, gastritis 1, bronchopneumonia 1, parasitism 2, car injury 1; 1 showed no significant lesions. The death of 1 fox was attributed to parasitism. 4) Distemper may be a frequent cause of death in raccoons and foxes, in epizootics which simulate rabies.

  7. Use of budesonide Turbuhaler in young children suspected of asthma

    DEFF Research Database (Denmark)

    Bisgaard, H; Pedersen, S; Nikander, K

    1994-01-01

    The question addressed in this study was the ability of young children to use a dry-powder inhaler, Turbuhaler. One hundred and sixty five children suspected of asthma, equally distributed in one year age-groups from 6 months to 8 yrs, inhaled from a Pulmicort Turbuhaler, 200 micrograms budesonide......-dose-1, through a filter. The amount of drug trapped by the filter was used as a measure of drug released to the patient. None of the children had prior experience in the use of a Turbuhaler, but they were instructed carefully, together with their parents, in the clinic. The median dose released revealed...... an age-dependent increase, with a considerable scatter. Accordingly, the dose delivered could not be predicted in these young children. The limitation to effective use in young children appeared to be lack of sufficient co-operation, rather than physical limitations, as even some very young children...

  8. Unenhanced MR Imaging in adults with clinically suspected acute appendicitis

    DEFF Research Database (Denmark)

    Chabanova, Elizaveta; Balslev, Ingegerd; Achiam, Michael;

    2011-01-01

    PURPOSE: The purpose of the study was to evaluate unenhanced Magnetic Resonance Imaging (MRI) for the diagnosis of appendicitis or another surgery-requiring condition in an adult population scheduled for emergency appendectomy based on a clinical diagnosis of suspected acute appendicitis. MATERIALS...... radiologists and one surgeon independent of each other and compared with surgical and pathological records. RESULTS: According to the surgical and histopathological findings 30 of 48 patients (63%) had acute appendicitis. Of the remaining 18 patients, 4 patients had no reasons for the clinical symptoms and 14...... patients had other pathology. For the three reviewers the performance of MRI in the diagnosis of acute appendicitis showed the following sensitivity, specificity and accuracy ranges: 83-93%, 50-83% and 77-83%. Moderate (kappa=0.51) and fair (kappa=0.31) interobserver agreements in the MR diagnosis of acute...

  9. Management of suspected monogenic lung fibrosis in a specialised centre

    Directory of Open Access Journals (Sweden)

    Raphael Borie

    2017-04-01

    Full Text Available At least 10% of patients with interstitial lung disease present monogenic lung fibrosis suspected on familial aggregation of pulmonary fibrosis, specific syndromes or early age of diagnosis. Approximately 25% of families have an identified mutation in genes mostly involved in telomere homeostasis, and more rarely in surfactant homeostasis. Beyond pathophysiological knowledge, detection of these mutations has practical consequence for patients. For instance, mutations involved in telomere homeostasis are associated with haematological complications after lung transplantation and may require adapted immunosuppression. Moreover, relatives may benefit from a clinical and genetic evaluation that should be specifically managed. The field of genetics of pulmonary fibrosis has made great progress in the last 10 years, raising specific problems that should be addressed by a specialised team.

  10. Language competence in forensic interviews for suspected child sexual abuse.

    Science.gov (United States)

    Fontes, Lisa A; Tishelman, Amy C

    2016-08-01

    Forensic interviews with children for suspected child sexual abuse require meeting children "where they are" in terms of their developmental level, readiness to disclose, culture, and language. The field lacks research indicating how to accommodate children's diverse cultural and linguistic backgrounds. This article focuses on language competence, defined here as the ability of an organization and its personnel (in this case, Child Advocacy Centers and forensic interviewers) to communicate effectively with clients regardless of their preferred language(s). In this qualitative study, 39 U.S. child forensic interviewers and child advocacy center directors discussed their experiences, practices, and opinions regarding interviews with children and families who are not native speakers of English. Topics include the importance of interviewing children in their preferred language, problems in interpreted interviews, bilingual interviews, and current and recommended procedures. Recommendations for practice and further research are included.

  11. Assessing capacity in suspected cases of self-neglect.

    Science.gov (United States)

    Naik, Aanand D; Lai, James M; Kunik, Mark E; Dyer, Carmel B

    2008-02-01

    Self-neglect is a serious and burgeoning public health challenge representing the most common problem faced by Adult Protective Services agencies. Among older adults who are vulnerable to self-neglect, the capacity to make decisions may remain intact. However, the capacity to identify and extract oneself from harmful situations, circumstances, or relationships may be diminished. A key ethical and clinical branch point in identifying older adults at risk for self-neglect involves determining whether the individual can both make and implement decisions regarding personal needs, health, and safety. The Articulate --> Demonstrate method is a practical and efficient way to screen capacity in the setting of suspected self-neglect. Once self-neglect has been identified, common clinical interventions can be targeted to the diagnosed deficits that foster vulnerability to neglect in older adults.

  12. CT diagnosis of suspected acute appendicitis in adult patients

    Energy Technology Data Exchange (ETDEWEB)

    Yamase, Hiroshi; Sahashi, Kiyomi; Kawai, Masayuki; Kishida, Yoshihiko; Sumida, Kei; Kawamura, Ken-ichi [Gifu Syakaihoken Hospital (Japan)

    1998-06-01

    In order to assess the CT diagnosis of suspected acute appendicitis, we performed abdominal contrasted CT measurements in 77 patients from 20 to 86 years old, and of 50 men and 27 women from June 1993 to June 1996. The surgical findings were compared with the preoperative CT findings. By the preoperative CT imaging, we can know the degree and the position of inflammation in appendix vermiformis and the degree and the spread of periappendicular inflammation in the case of appendicitis, and can make a differential diagnosis of diverticulitis or gynecological diseases from appendicitis. It is important to make a preoperative diagnosis by the objectively excellent abdominal CT imaging and to avoid unnecessary surgery. (K.H.)

  13. The Mental Status Examination in Patients With Suspected Dementia

    Science.gov (United States)

    Grossman, Murray; Irwin, David J.

    2016-01-01

    ABSTRACT Purpose of Review: This article describes a comprehensive approach to the mental status examination and diagnostic workup of patients suspected of having an emerging neurodegenerative dementia. Key strategies for obtaining a history and bedside examination techniques are highlighted. Recent Findings: Classic descriptions of behavioral neurology syndromes were largely based on clinicopathologic correlations of strategic lesions in stroke patients. While still very important, advances in neuroimaging have expanded our armamentarium of cognitive evaluations to include assessments of findings in nonstroke anatomic distributions of disease. These efforts support comprehensive assessments of large-scale cerebral networks in cognitive neurology. Summary: A thorough and focused mental status examination is essential for the evaluation of patients with cognitive symptoms. Selective use of laboratory testing and neuroimaging can aid in the diagnosis of dementia by excluding non-neurodegenerative etiologies. Neurodegenerative disease–specific tests are in development and will enhance diagnosis and efforts for disease-modifying therapy development. PMID:27042900

  14. Na+ Cl- ion pair association in water-DMSO mixtures: Effect of ion pair model potentials

    Indian Academy of Sciences (India)

    ATANU SARKAR; ANUPAM CHATTERJEE; S C TIWARI; B L TEMBE

    2016-06-01

    Potentials of Mean Force (PMF) for the Na+ Cl- ion pair in water–dimethyl sulfoxide (DMSO)mixtures for three DMSO mole fractions have been computed using constrained Molecular Dynamics (MD)simulations and confirmed by dynamical trajectories and residence times of the ion pair at various inter-ionicseparations. The three ion-ion direct potentials used are 12-6-1, exp-6-1 and exp-8-6-1. The physical picturethat emerges is that there is a strong contact ion pair (CIP) and strong to moderate solvent separated ion pair(SSIP) in these solutions. Analysis of local ion clusters shows that ions are dominantly solvated by watermolecules. The 12-6-1 potential model predicts running coordination numbers closest to experimental data.

  15. Root mean square radii of heavy flavoured mesons in a quantum chromodynamics potential model

    Indian Academy of Sciences (India)

    D K CHOUDHURY; TAPASHI DAS

    2016-10-01

    We report the results of root mean square (r.m.s.) radii of heavy flavoured mesons in a QCD model with the potential $V (r) = −(4\\alpha_{s}/3r) + br + c$. As the potential is not analytically solvable, we first obtain the results in the absence of confinement and Coulomb terms respectively. Confinement and Coulomb effects are then introduced successively in the approach using the Dalgarno’s method of perturbation. We explicitly consider the following two quantum mechanical aspects in the analysis: (a) The scale factor $c$ in the potential should not effect the wave function of the system even while applying the perturbation theory. (b) Choice of perturbative piece of the Hamiltonian (confinement or linear) should determine the effective radial separation between the quarks and antiquarks. The results are then compared with the available theoretical values of r.m.s. radii.

  16. Remarks on the static potential driven by vacuum nonlinearities in $D=3$ models

    CERN Document Server

    Gaete, Patricio

    2016-01-01

    Within the framework of the gauge-invariant, but path-dependent, variables formalism, we study the manifestations of vacuum electromagnetic nonlinearities in $D=3$ models. For this we consider both generalized Born-Infeld and Pagels-Tomboulis-like electrodynamics, as well as, an Euler-Heisenberg-like electrodynamics. We explicitly show that generalized Born-Infeld and Pagels-Tomboulis-like electrodynamics are equivalent, where the static potential profile contains a long-range (${\\raise0.5ex\\hbox{$\\scriptstyle 1$}\\kern-0.1em/\\kern-0.15em\\lower0.25ex\\hbox{$\\scriptstyle {{r^2}}$}}$-type) correction to the Coulomb potential. Interestingly enough, for an Euler-Heisenberg-like electrodynamics the interaction energy contains a linear potential, leading to the confinement of static charges.

  17. Bottomonium states versus recent experimental observations in the QCD-inspired potential model

    Institute of Scientific and Technical Information of China (English)

    TIAN Wei-Zhao; CAO Lu; YANG You-Chang; CHEN Hong

    2013-01-01

    In the QCD-inspired potential model where the quark-antiquark interaction consists of the usual onegluon-exchange and the mixture of long-range scalar and vector linear confining potentials with the lowest order relativistic correction,we investigate the mass spectra and electromagnetic processes of a bottomonium system by using the Gaussian expansion method.It reveals that the vector component of the mixing confinement is anticonfining and takes around 18.51% of the confining potential.Combining the new experimental data released by Belle,BaBar and LHC,we systematically discuss the energy levels of the bottomonium states and make the predictions of the electromagnetic decays for further experiments.

  18. Isotropization in Bianchi type-I cosmological model with fermions and bosons interacting via Yukawa potential

    Science.gov (United States)

    Ribas, M. O.; Samojeden, L. L.; Devecchi, F. P.; Kremer, G. M.

    2015-10-01

    In this work we investigate a model for the early Universe in a Bianchi type-I metric, where the sources of the gravitational field are a fermionic and a bosonic field, interacting through a Yukawa potential, following the standard model of elementary particles. It is shown that the fermionic field has a negative pressure, while the boson has a small positive pressure. The fermionic field is the responsible for an accelerated regime at early times, but since the total pressure tends to zero for large times, a transition to a decelerated regime occurs. Here the Yukawa potential answers for the duration of the accelerated regime, since by decreasing the value of its coupling constant the transition accelerated-decelerated occurs in later times. The isotropization which occurs for late times is due to the presence of the fermionic field as one of the sources of the gravitational field.

  19. Isotropization in Bianchi type-I cosmological model with fermions and bosons interacting via Yukawa potential

    CERN Document Server

    Ribas, M O; Devecchi, F P; Kremer, G M

    2015-01-01

    In this work we investigate a model for the early Universe in a Bianchi type-I metric, where the sources of the gravitational field are a fermionic and a bosonic field, interacting through a Yukawa potential, following the standard model of elementary particles. It is shown that the fermionic field has a negative pressure, while the boson has a small positive pressure. The fermionic field is the responsible for an accelerated regime at early times, but since the total pressure tends to zero for large times, a transition to a decelerated regime occurs. Here the Yukawa potential answers for the duration of the accelerated regime, since by decreasing the value of its coupling constant the transition accelerated-decelerated occurs in later times. The isotropization which occurs for late times is due to the presence of the fermionic field as one of the sources of the gravitational field.

  20. Spatial modelling of landscape aesthetic potential in urban-rural fringes.

    Science.gov (United States)

    Sahraoui, Yohan; Clauzel, Céline; Foltête, Jean-Christophe

    2016-10-01

    The aesthetic potential of landscape has to be modelled to provide tools for land-use planning. This involves identifying landscape attributes and revealing individuals' landscape preferences. Landscape aesthetic judgments of individuals (n = 1420) were studied by means of a photo-based survey. A set of landscape visibility metrics was created to measure landscape composition and configuration in each photograph using spatial data. These metrics were used as explanatory variables in multiple linear regressions to explain aesthetic judgments. We demonstrate that landscape aesthetic judgments may be synthesized in three consensus groups. The statistical results obtained show that landscape visibility metrics have good explanatory power. Ultimately, we propose a spatial modelling of landscape aesthetic potential based on these results combined with systematic computation of visibility metrics.

  1. A STREAMLINE-BASED PREDICTIVE MODEL FOR ENHANCED-OIL-RECOVERY POTENTIALITY

    Institute of Scientific and Technical Information of China (English)

    HOU Jian; ZHANG Shun-kang; DU Qing-jun; LI Yu-bin

    2008-01-01

    A pseudo-three-dimensional model of potentiality prediction is proposed for enhanced oil recovery, based on the streamline method described in this article. The potential distribution of the flow through a porous medium under a complicated boundary condition is solved with the boundary element method. Furthermore, the method for tracing streamlines between injection wells and producing wells is presented. Based on the results, a numerical solution can be obtained by solving the seepage problem of the stream-tube with consideration of different methods of Enhanced Oil Recovery(EOR). The advantage of the method given in this article is that it can obtain dynamic calculation with different well patterns of any shape by easily considering different physicochemical phenomena having less calculation time and good stability. Based on the uniform theory basis-streamline method, different models, including CO2 miscible flooding, polymer flooding, alkaline/surfactant/polymer flooding and microbial flooding, are established in this article.

  2. Identification and model based assessment of the potential water retention caused by land-use changes

    Directory of Open Access Journals (Sweden)

    A. Wahren

    2007-06-01

    Full Text Available The extreme summer flood in the Elbe River watershed initiated a debate on the role of forest conversion and afforestation as measures for preventive flood protection. To quantify the effect of forest conversion and afforestation on flood runoff from catchments reliable model calculations are essential. The article overviews the present state of our work and provides an example for a model- based assessment of potential water retention caused by land-use changes in a catchment in the Central Ore Mountains (Saxony, Germany. The potential of flood control by land-use management measures is highly dependant on the site-specific soil and relief conditions and the rainfall event characteristics. The pre-event soil moisture is distinctly lower under forest land-use. Furthermore, infiltration, percolation in the subsoil is increased. These effects exist for small/medium-scale events whereas they become marginal for extreme events.

  3. Visual Evoked Potential Recording in a Rat Model of Experimental Optic Nerve Demyelination.

    Science.gov (United States)

    You, Yuyi; Gupta, Vivek K; Chitranshi, Nitin; Reedman, Brittany; Klistorner, Alexander; Graham, Stuart L

    2015-07-29

    The visual evoked potential (VEP) recording is widely used in clinical practice to assess the severity of optic neuritis in its acute phase, and to monitor the disease course in the follow-up period. Changes in the VEP parameters closely correlate with pathological damage in the optic nerve. This protocol provides a detailed description about the rodent model of optic nerve microinjection, in which a partial demyelination lesion is produced in the optic nerve. VEP recording techniques are also discussed. Using skull implanted electrodes, we are able to acquire reproducible intra-session and between-session VEP traces. VEPs can be recorded on individual animals over a period of time to assess the functional changes in the optic nerve longitudinally. The optic nerve demyelination model, in conjunction with the VEP recording protocol, provides a tool to investigate the disease processes associated with demyelination and remyelination, and can potentially be employed to evaluate the effects of new remyelinating drugs or neuroprotective therapies.

  4. Potential Field Cellular Automata Model for Pedestrian Evacuation in a Domain with a Ramp

    Directory of Open Access Journals (Sweden)

    Xiao-Xia Jian

    2014-01-01

    Full Text Available We propose a potential field cellular automata model with a pushing force field to simulate the pedestrian evacuation in a domain with a ramp. We construct a cost potential depending on the ramp angle and introduce a function to evaluate the pushing force, which is related to the cost and the desired direction of pedestrian. With increase of crowd density, there is no empty space for pedestrian moving forward; pedestrian will purposefully push another pedestrian on her or his desired location to arrive the destination quickly. We analyse the relationship between the slope of ramp and the pushing force and investigate the changing of injured situations with the changing of the slope of ramp. When the number of pedestrians and the ramp angle arrive at certain critical points, the Domino effect will be simulated by this proposed model.

  5. Modification of transition's factor in the compact surface-potential-based MOSFET model

    Directory of Open Access Journals (Sweden)

    Kevkić Tijana

    2016-01-01

    Full Text Available The modification of an important transition's factor which enables continual behavior of the surface potential in entire useful range of MOSFET operation is presented. The various modifications have been made in order to obtain an accurate and computationally efficient compact MOSFET model. The best results have been achieved by introducing the generalized logistic function (GL in fitting of considered factor. The smoothness and speed of the transition of the surface potential from the depletion to the strong inversion region can be controlled in this way. The results of the explicit model with this GL functional form for transition's factor have been verified extensively with the numerical data. A great agreement was found for a wide range of substrate doping and oxide thickness. Moreover, the proposed approach can be also applied on the case where quantum mechanical effects play important role in inversion mode.

  6. Integrability and chemical potential in the (3 + 1)-dimensional Skyrme model

    Science.gov (United States)

    Alvarez, P. D.; Canfora, F.; Dimakis, N.; Paliathanasis, A.

    2017-10-01

    Using a remarkable mapping from the original (3 + 1)dimensional Skyrme model to the Sine-Gordon model, we construct the first analytic examples of Skyrmions as well as of Skyrmions-anti-Skyrmions bound states within a finite box in 3 + 1 dimensional flat space-time. An analytic upper bound on the number of these Skyrmions-anti-Skyrmions bound states is derived. We compute the critical isospin chemical potential beyond which these Skyrmions cease to exist. With these tools, we also construct topologically protected time-crystals: time-periodic configurations whose time-dependence is protected by their non-trivial winding number. These are striking realizations of the ideas of Shapere and Wilczek. The critical isospin chemical potential for these time-crystals is determined.

  7. The impact of sea surface currents in wave power potential modeling

    Science.gov (United States)

    Zodiatis, George; Galanis, George; Kallos, George; Nikolaidis, Andreas; Kalogeri, Christina; Liakatas, Aristotelis; Stylianou, Stavros

    2015-11-01

    The impact of sea surface currents to the estimation and modeling of wave energy potential over an area of increased economic interest, the Eastern Mediterranean Sea, is investigated in this work. High-resolution atmospheric, wave, and circulation models, the latter downscaled from the regional Mediterranean Forecasting System (MFS) of the Copernicus marine service (former MyOcean regional MFS system), are utilized towards this goal. The modeled data are analyzed by means of a variety of statistical tools measuring the potential changes not only in the main wave characteristics, but also in the general distribution of the wave energy and the wave parameters that mainly affect it, when using sea surface currents as a forcing to the wave models. The obtained results prove that the impact of the sea surface currents is quite significant in wave energy-related modeling, as well as temporally and spatially dependent. These facts are revealing the necessity of the utilization of the sea surface currents characteristics in renewable energy studies in conjunction with their meteo-ocean forecasting counterparts.

  8. Modeling In-stream Tidal Energy Extraction and Its Potential Environmental Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea; Geerlofs, Simon H.

    2014-09-30

    In recent years, there has been growing interest in harnessing in-stream tidal energy in response to concerns of increasing energy demand and to mitigate climate change impacts. While many studies have been conducted to assess and map tidal energy resources, efforts for quantifying the associated potential environmental impacts have been limited. This paper presents the development of a tidal turbine module within a three-dimensional unstructured-grid coastal ocean model and its application for assessing the potential environmental impacts associated with tidal energy extraction. The model is used to investigate in-stream tidal energy extraction and associated impacts on estuarine hydrodynamic and biological processes in a tidally dominant estuary. A series of numerical experiments with varying numbers and configurations of turbines installed in an idealized estuary were carried out to assess the changes in the hydrodynamics and biological processes due to tidal energy extraction. Model results indicated that a large number of turbines are required to extract the maximum tidal energy and cause significant reduction of the volume flux. Preliminary model results also indicate that extraction of tidal energy increases vertical mixing and decreases flushing rate in a stratified estuary. The tidal turbine model was applied to simulate tidal energy extraction in Puget Sound, a large fjord-like estuary in the Pacific Northwest coast.

  9. Study of Monte Carlo Simulation Method for Methane Phase Diagram Prediction using Two Different Potential Models

    KAUST Repository

    Kadoura, Ahmad

    2011-06-06

    Lennard‐Jones (L‐J) and Buckingham exponential‐6 (exp‐6) potential models were used to produce isotherms for methane at temperatures below and above critical one. Molecular simulation approach, particularly Monte Carlo simulations, were employed to create these isotherms working with both canonical and Gibbs ensembles. Experiments in canonical ensemble with each model were conducted to estimate pressures at a range of temperatures above methane critical temperature. Results were collected and compared to experimental data existing in literature; both models showed an elegant agreement with the experimental data. In parallel, experiments below critical temperature were run in Gibbs ensemble using L‐J model only. Upon comparing results with experimental ones, a good fit was obtained with small deviations. The work was further developed by adding some statistical studies in order to achieve better understanding and interpretation to the estimated quantities by the simulation. Methane phase diagrams were successfully reproduced by an efficient molecular simulation technique with different potential models. This relatively simple demonstration shows how powerful molecular simulation methods could be, hence further applications on more complicated systems are considered. Prediction of phase behavior of elemental sulfur in sour natural gases has been an interesting and challenging field in oil and gas industry. Determination of elemental sulfur solubility conditions helps avoiding all kinds of problems caused by its dissolution in gas production and transportation processes. For this purpose, further enhancement to the methods used is to be considered in order to successfully simulate elemental sulfur phase behavior in sour natural gases mixtures.

  10. Parameterizing the Morse potential for coarse-grained modeling of blood plasma

    Science.gov (United States)

    Zhang, Na; Zhang, Peng; Kang, Wei; Bluestein, Danny; Deng, Yuefan

    2014-01-01

    Multiscale simulations of fluids such as blood represent a major computational challenge of coupling the disparate spatiotemporal scales between molecular and macroscopic transport phenomena characterizing such complex fluids. In this paper, a coarse-grained (CG) particle model is developed for simulating blood flow by modifying the Morse potential, traditionally used in Molecular Dynamics for modeling vibrating structures. The modified Morse potential is parameterized with effective mass scales for reproducing blood viscous flow properties, including density, pressure, viscosity, compressibility and characteristic flow dynamics of human blood plasma fluid. The parameterization follows a standard inverse-problem approach in which the optimal micro parameters are systematically searched, by gradually decoupling loosely correlated parameter spaces, to match the macro physical quantities of viscous blood flow. The predictions of this particle based multiscale model compare favorably to classic viscous flow solutions such as Counter-Poiseuille and Couette flows. It demonstrates that such coarse grained particle model can be applied to replicate the dynamics of viscous blood flow, with the advantage of bridging the gap between macroscopic flow scales and the cellular scales characterizing blood flow that continuum based models fail to handle adequately.

  11. Parameterizing the Morse potential for coarse-grained modeling of blood plasma

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Na [Department of Applied Mathematics and Statistics, Stony Brook University, NY 11794 (United States); Zhang, Peng [Department of Biomedical Engineering, Stony Brook University, NY 11790 (United States); Kang, Wei [Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing 100871 (China); Bluestein, Danny [Department of Biomedical Engineering, Stony Brook University, NY 11790 (United States); Deng, Yuefan, E-mail: Yuefan.Deng@StonyBrook.edu [Department of Applied Mathematics and Statistics, Stony Brook University, NY 11794 (United States)

    2014-01-15

    Multiscale simulations of fluids such as blood represent a major computational challenge of coupling the disparate spatiotemporal scales between molecular and macroscopic transport phenomena characterizing such complex fluids. In this paper, a coarse-grained (CG) particle model is developed for simulating blood flow by modifying the Morse potential, traditionally used in Molecular Dynamics for modeling vibrating structures. The modified Morse potential is parameterized with effective mass scales for reproducing blood viscous flow properties, including density, pressure, viscosity, compressibility and characteristic flow dynamics of human blood plasma fluid. The parameterization follows a standard inverse-problem approach in which the optimal micro parameters are systematically searched, by gradually decoupling loosely correlated parameter spaces, to match the macro physical quantities of viscous blood flow. The predictions of this particle based multiscale model compare favorably to classic viscous flow solutions such as Counter-Poiseuille and Couette flows. It demonstrates that such coarse grained particle model can be applied to replicate the dynamics of viscous blood flow, with the advantage of bridging the gap between macroscopic flow scales and the cellular scales characterizing blood flow that continuum based models fail to handle adequately.

  12. Characterization of plasma thiol redox potential in a common marmoset model of aging

    Directory of Open Access Journals (Sweden)

    James R. Roede

    2013-01-01

    Full Text Available Due to its short lifespan, ease of use and age-related pathologies that mirror those observed in humans, the common marmoset (Callithrix jacchus is poised to become a standard nonhuman primate model of aging. Blood and extracellular fluid possess two major thiol-dependent redox nodes involving cysteine (Cys, cystine (CySS, glutathione (GSH and glutathione disulfide (GSSG. Alteration in these plasma redox nodes significantly affects cellular physiology, and oxidation of the plasma Cys/CySS redox potential (EhCySS is associated with aging and disease risk in humans. The purpose of this study was to determine age-related changes in plasma redox metabolites and corresponding redox potentials (Eh to further validate the marmoset as a nonhuman primate model of aging. We measured plasma thiol redox states in marmosets and used existing human data with multivariate adaptive regression splines (MARS to model the relationships between age and redox metabolites. A classification accuracy of 70.2% and an AUC of 0.703 were achieved using the MARS model built from the marmoset redox data to classify the human samples as young or old. These results show that common marmosets provide a useful model for thiol redox biology of aging.

  13. pynoddy 1.0: an experimental platform for automated 3-D kinematic and potential field modelling

    Science.gov (United States)

    Florian Wellmann, J.; Thiele, Sam T.; Lindsay, Mark D.; Jessell, Mark W.

    2016-03-01

    We present a novel methodology for performing experiments with subsurface structural models using a set of flexible and extensible Python modules. We utilize the ability of kinematic modelling techniques to describe major deformational, tectonic, and magmatic events at low computational cost to develop experiments testing the interactions between multiple kinematic events, effect of uncertainty regarding event timing, and kinematic properties. These tests are simple to implement and perform, as they are automated within the Python scripting language, allowing the encapsulation of entire kinematic experiments within high-level class definitions and fully reproducible results. In addition, we provide a link to geophysical potential-field simulations to evaluate the effect of parameter uncertainties on maps of gravity and magnetics. We provide relevant fundamental information on kinematic modelling and our implementation, and showcase the application of our novel methods to investigate the interaction of multiple tectonic events on a pre-defined stratigraphy, the effect of changing kinematic parameters on simulated geophysical potential fields, and the distribution of uncertain areas in a full 3-D kinematic model, based on estimated uncertainties in kinematic input parameters. Additional possibilities for linking kinematic modelling to subsequent process simulations are discussed, as well as additional aspects of future research. Our modules are freely available on github, including documentation and tutorial examples, and we encourage the contribution to this project.

  14. Inverse modeling of soil characteristics from surface soil moisture observations: potential and limitations

    Directory of Open Access Journals (Sweden)

    A. Loew

    2008-01-01

    Full Text Available Land surface models (LSM are widely used as scientific and operational tools to simulate mass and energy fluxes within the soil vegetation atmosphere continuum for numerous applications in meteorology, hydrology or for geobiochemistry studies. A reliable parameterization of these models is important to improve the simulation skills. Soil moisture is a key variable, linking the water and energy fluxes at the land surface. An appropriate parameterisation of soil hydraulic properties is crucial to obtain reliable simulation of soil water content from a LSM scheme. Parameter inversion techniques have been developed for that purpose to infer model parameters from soil moisture measurements at the local scale. On the other hand, remote sensing methods provide a unique opportunity to estimate surface soil moisture content at different spatial scales and with different temporal frequencies and accuracies. The present paper investigates the potential to use surface soil moisture information to infer soil hydraulic characteristics using uncertain observations. Different approaches to retrieve soil characteristics from surface soil moisture observations is evaluated and the impact on the accuracy of the model predictions is quantified. The results indicate that there is in general potential to improve land surface model parameterisations by assimilating surface soil moisture observations. However, a high accuracy in surface soil moisture estimates is required to obtain reliable estimates of soil characteristics.

  15. Comparing potential recharge estimates from three Land Surface Models across the western US

    Science.gov (United States)

    Niraula, Rewati; Meixner, Thomas; Ajami, Hoori; Rodell, Matthew; Gochis, David; Castro, Christopher L.

    2017-02-01

    Groundwater is a major source of water in the western US. However, there are limited recharge estimates in this region due to the complexity of recharge processes and the challenge of direct observations. Land surface Models (LSMs) could be a valuable tool for estimating current recharge and projecting changes due to future climate change. In this study, simulations of three LSMs (Noah, Mosaic and VIC) obtained from the North American Land Data Assimilation System (NLDAS-2) are used to estimate potential recharge in the western US. Modeled recharge was compared with published recharge estimates for several aquifers in the region. Annual recharge to precipitation ratios across the study basins varied from 0.01% to 15% for Mosaic, 3.2% to 42% for Noah, and 6.7% to 31.8% for VIC simulations. Mosaic consistently underestimates recharge across all basins. Noah captures recharge reasonably well in wetter basins, but overestimates it in drier basins. VIC slightly overestimates recharge in drier basins and slightly underestimates it for wetter basins. While the average annual recharge values vary among the models, the models were consistent in identifying high and low recharge areas in the region. Models agree in seasonality of recharge occurring dominantly during the spring across the region. Overall, our results highlight that LSMs have the potential to capture the spatial and temporal patterns as well as seasonality of recharge at large scales. Therefore, LSMs (specifically VIC and Noah) can be used as a tool for estimating future recharge in data limited regions.

  16. pynoddy 1.0: an experimental platform for automated 3-D kinematic and potential field modelling

    Directory of Open Access Journals (Sweden)

    J. F. Wellmann

    2015-11-01

    Full Text Available We present a novel methodology for performing experiments with subsurface structural models using a set of flexible and extensible Python modules. We utilise the ability of kinematic modelling techniques to describe major deformational, tectonic, and magmatic events at low computational cost to develop experiments testing the interactions between multiple kinematic events, effect of uncertainty regarding event timing, and kinematic properties. These tests are simple to implement and perform, as they are automated within the Python scripting language, allowing the encapsulation of entire kinematic experiments within high-level class definitions and fully reproducible results. In addition, we provide a~link to geophysical potential-field simulations to evaluate the effect of parameter uncertainties on maps of gravity and magnetics. We provide relevant fundamental information on kinematic modelling and our implementation, and showcase the application of our novel methods to investigate the interaction of multiple tectonic events on a pre-defined stratigraphy, the effect of changing kinematic parameters on simulated geophysical potential-fields, and the distribution of uncertain areas in a full 3-D kinematic model, based on estimated uncertainties in kinematic input parameters. Additional possibilities for linking kinematic modelling to subsequent process simulations are discussed, as well as additional aspects of future research. Our modules are freely available on github, including documentation and tutorial examples, and we encourage the contribution to this project.

  17. Modeling potential distribution of Oligoryzomys longicaudatus, the Andes virus (Genus: Hantavirus) reservoir, in Argentina.

    Science.gov (United States)

    Andreo, Verónica; Glass, Gregory; Shields, Timothy; Provensal, Cecilia; Polop, Jaime

    2011-09-01

    We constructed a model to predict the potential distribution of Oligoryzomys longicaudatus, the reservoir of Andes virus (Genus: Hantavirus), in Argentina. We developed an extensive database of occurrence records from published studies and our own surveys and compared two methods to model the probability of O. longicaudatus presence; logistic regression and MaxEnt algorithm. The environmental variables used were tree, grass and bare soil cover from MODIS imagery and, altitude and 19 bioclimatic variables from WorldClim database. The models performances were evaluated and compared both by threshold dependent and independent measures. The best models included tree and grass cover, mean diurnal temperature range, and precipitation of the warmest and coldest seasons. The potential distribution maps for O. longicaudatus predicted the highest occurrence probabilities along the Andes range, from 32°S and narrowing southwards. They also predicted high probabilities for the south-central area of Argentina, reaching the Atlantic coast. The Hantavirus Pulmonary Syndrome cases coincided with mean occurrence probabilities of 95 and 77% for logistic and MaxEnt models, respectively. HPS transmission zones in Argentine Patagonia matched the areas with the highest probability of presence. Therefore, colilargos presence probability may provide an approximate risk of transmission and act as an early tool to guide control and prevention plans.

  18. Potential and limitations of multidecadal satellite soil moisture observations for selected climate model evaluation studies

    Directory of Open Access Journals (Sweden)

    A. Loew

    2013-09-01

    Full Text Available Soil moisture is an essential climate variable (ECV of major importance for land–atmosphere interactions and global hydrology. An appropriate representation of soil moisture dynamics in global climate models is therefore important. Recently, a first multidecadal, observation-based soil moisture dataset has become available that provides information on soil moisture dynamics from satellite observations (ECVSM, essential climate variable soil moisture. The present study investigates the potential and limitations of this new dataset for several applications in climate model evaluation. We compare soil moisture data from satellite observations, reanalysis and simulations from a state-of-the-art land surface model and analyze relationships between soil moisture and precipitation anomalies in the different dataset. Other potential applications like model parameter optimization or model initialization are not investigated in the present study. In a detailed regional study, we show that ECVSM is capable to capture well the interannual and intraannual soil moisture and precipitation dynamics in the Sahelian region. Current deficits of the new dataset are critically discussed and summarized at the end of the paper to provide guidance for an appropriate usage of the ECVSM dataset for climate studies.

  19. Estimating European soil organic carbon mitigation potential in a global integrated land use model

    Science.gov (United States)

    Frank, Stefan; Böttcher, Hannes; Schneider, Uwe; Schmid, Erwin; Havlík, Petr

    2013-04-01

    Several studies have shown the dynamic interaction between soil organic carbon (SOC) sequestration rates, soil management decisions and SOC levels. Management practices such as reduced and no-tillage, improved residue management and crop rotations as well as the conversion of marginal cropland to native vegetation or conversion of cultivated land to permanent grassland offer the potential to increase SOC content. Even though dynamic interactions are widely acknowledged in literature, they have not been implemented in most existing land use decision models. A major obstacle is the high data and computing requirements for an explicit representation of alternative land use sequences since a model has to be able to track all different management decision paths. To our knowledge no study accounted so far for SOC dynamics explicitly in a global integrated land use model. To overcome these conceptual difficulties described above we apply an approach capable of accounting for SOC dynamics in GLOBIOM (Global Biosphere Management Model), a global recursive dynamic partial equilibrium bottom-up model integrating the agricultural, bioenergy and forestry sectors. GLOBIOM represents all major land based sectors and therefore is able to account for direct and indirect effects of land use change as well as leakage effects (e.g. through trade) implicitly. Together with the detailed representation of technologies (e.g. tillage and fertilizer management systems), these characteristics make the model a highly valuable tool for assessing European SOC emissions and mitigation potential. Demand and international trade are represented in this version of the model at the level of 27 EU member states and 23 aggregated world regions outside Europe. Changes in the demand on the one side, and profitability of the different land based activities on the other side, are the major determinants of land use change in GLOBIOM. In this paper we estimate SOC emissions from cropland for the EU until

  20. Radiative decay of mesons in an independent-quark potential model

    Energy Technology Data Exchange (ETDEWEB)

    Barik, N.; Dash, P.C. (Department of Physics, Utkal University, Bhubaneswar 751004 (India)); Panda, A.R. (Department of Physics, Kendrapara College, Kendrapara, Orissa (India))

    1992-11-01

    We investigate in a potential model of independent quarks the {ital M}1 transitions among the low-lying vector ({ital V}) and pseudoscalar ({ital P}) mesons. We perform a static'' calculation of the partial decay widths of twelve possible {ital M}1 transitions such as {ital V}{r arrow}{ital P}{gamma} and {ital P}{r arrow}{ital V}{gamma} within the traditional picture of photon emission by a confined quark and/or antiquark. The model accounts well for the observed decay widths.