WorldWideScience

Sample records for models including mice

  1. A gamma variate model that includes stretched exponential is a better fit for gastric emptying data from mice.

    Science.gov (United States)

    Bajzer, Željko; Gibbons, Simon J; Coleman, Heidi D; Linden, David R; Farrugia, Gianrico

    2015-08-01

    Noninvasive breath tests for gastric emptying are important techniques for understanding the changes in gastric motility that occur in disease or in response to drugs. Mice are often used as an animal model; however, the gamma variate model currently used for data analysis does not always fit the data appropriately. The aim of this study was to determine appropriate mathematical models to better fit mouse gastric emptying data including when two peaks are present in the gastric emptying curve. We fitted 175 gastric emptying data sets with two standard models (gamma variate and power exponential), with a gamma variate model that includes stretched exponential and with a proposed two-component model. The appropriateness of the fit was assessed by the Akaike Information Criterion. We found that extension of the gamma variate model to include a stretched exponential improves the fit, which allows for a better estimation of T1/2 and Tlag. When two distinct peaks in gastric emptying are present, a two-component model is required for the most appropriate fit. We conclude that use of a stretched exponential gamma variate model and when appropriate a two-component model will result in a better estimate of physiologically relevant parameters when analyzing mouse gastric emptying data.

  2. Including Magnetostriction in Micromagnetic Models

    Science.gov (United States)

    Conbhuí, Pádraig Ó.; Williams, Wyn; Fabian, Karl; Nagy, Lesleis

    2016-04-01

    The magnetic anomalies that identify crustal spreading are predominantly recorded by basalts formed at the mid-ocean ridges, whose magnetic signals are dominated by iron-titanium-oxides (Fe3-xTixO4), so called "titanomagnetites", of which the Fe2.4Ti0.6O4 (TM60) phase is the most common. With sufficient quantities of titanium present, these minerals exhibit strong magnetostriction. To date, models of these grains in the pseudo-single domain (PSD) range have failed to accurately account for this effect. In particular, a popular analytic treatment provided by Kittel (1949) for describing the magnetostrictive energy as an effective increase of the anisotropy constant can produce unphysical strains for non-uniform magnetizations. I will present a rigorous approach based on work by Brown (1966) and by Kroner (1958) for including magnetostriction in micromagnetic codes which is suitable for modelling hysteresis loops and finding remanent states in the PSD regime. Preliminary results suggest the more rigorously defined micromagnetic models exhibit higher coercivities and extended single domain ranges when compared to more simplistic approaches.

  3. DEVELOPMENT OF WATER CIRCULATION MODEL INCLUDING IRRIGATION

    Science.gov (United States)

    Kotsuki, Shunji; Tanaka, Kenji; Kojiri, Toshiharu; Hamaguchi, Toshio

    It is well known that since agricultural water withdrawal has much affect on water circulation system, accurate analysis of river discharge or water balance are difficult with less regard for it. In this study, water circulation model composed of land surface model and distributed runoff model is proposed at 10km 10km resolution. In this model, irrigation water, which is estimated with land surface model, is introduced to river discharge analysis. The model is applied to the Chao Phraya River in Thailand, and reproduced seasonal water balance. Additionally, the discharge on dry season simulated with the model is improved as a result of including irrigation. Since the model, which is basically developed from global data sets, simulated seasonal change of river discharge, it can be suggested that our model has university to other river basins.

  4. Models of bovine babesiosis including juvenile cattle.

    Science.gov (United States)

    Saad-Roy, C M; Shuai, Zhisheng; van den Driessche, P

    2015-03-01

    Bovine Babesiosis in cattle is caused by the transmission of protozoa of Babesia spp. by ticks as vectors. Juvenile cattle (Babesiosis, rarely show symptoms, and acquire immunity upon recovery. Susceptibility to the disease varies between breeds of cattle. Models of the dynamics of Bovine Babesiosis transmitted by the cattle tick that include these factors are formulated as systems of ordinary differential equations. Basic reproduction numbers are calculated, and it is proved that if these numbers are below the threshold value of one, then Bovine Babesiosis dies out. However, above the threshold number of one, the disease may approach an endemic state. In this case, control measures are suggested by determining target reproduction numbers. The percentage of a particular population (for example, the adult bovine population) needed to be controlled to eradicate the disease is evaluated numerically using Columbia data from the literature.

  5. An Integrated Biochemistry Laboratory, Including Molecular Modeling

    Science.gov (United States)

    Hall, Adele J. Wolfson Mona L.; Branham, Thomas R.

    1996-11-01

    ) experience with methods of protein purification; (iii) incorporation of appropriate controls into experiments; (iv) use of basic statistics in data analysis; (v) writing papers and grant proposals in accepted scientific style; (vi) peer review; (vii) oral presentation of results and proposals; and (viii) introduction to molecular modeling. Figure 1 illustrates the modular nature of the lab curriculum. Elements from each of the exercises can be separated and treated as stand-alone exercises, or combined into short or long projects. We have been able to offer the opportunity to use sophisticated molecular modeling in the final module through funding from an NSF-ILI grant. However, many of the benefits of the research proposal can be achieved with other computer programs, or even by literature survey alone. Figure 1.Design of project-based biochemistry laboratory. Modules (projects, or portions of projects) are indicated as boxes. Each of these can be treated independently, or used as part of a larger project. Solid lines indicate some suggested paths from one module to the next. The skills and knowledge required for protein purification and design are developed in three units: (i) an introduction to critical assays needed to monitor degree of purification, including an evaluation of assay parameters; (ii) partial purification by ion-exchange techniques; and (iii) preparation of a grant proposal on protein design by mutagenesis. Brief descriptions of each of these units follow, with experimental details of each project at the end of this paper. Assays for Lysozyme Activity and Protein Concentration (4 weeks) The assays mastered during the first unit are a necessary tool for determining the purity of the enzyme during the second unit on purification by ion exchange. These assays allow an introduction to the concept of specific activity (units of enzyme activity per milligram of total protein) as a measure of purity. In this first sequence, students learn a turbidimetric assay

  6. Seepage Model for PA Including Dift Collapse

    Energy Technology Data Exchange (ETDEWEB)

    G. Li; C. Tsang

    2000-12-20

    The purpose of this Analysis/Model Report (AMR) is to document the predictions and analysis performed using the Seepage Model for Performance Assessment (PA) and the Disturbed Drift Seepage Submodel for both the Topopah Spring middle nonlithophysal and lower lithophysal lithostratigraphic units at Yucca Mountain. These results will be used by PA to develop the probability distribution of water seepage into waste-emplacement drifts at Yucca Mountain, Nevada, as part of the evaluation of the long term performance of the potential repository. This AMR is in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' (CRWMS M&O 2000 [153447]). This purpose is accomplished by performing numerical simulations with stochastic representations of hydrological properties, using the Seepage Model for PA, and evaluating the effects of an alternative drift geometry representing a partially collapsed drift using the Disturbed Drift Seepage Submodel. Seepage of water into waste-emplacement drifts is considered one of the principal factors having the greatest impact of long-term safety of the repository system (CRWMS M&O 2000 [153225], Table 4-1). This AMR supports the analysis and simulation that are used by PA to develop the probability distribution of water seepage into drift, and is therefore a model of primary (Level 1) importance (AP-3.15Q, ''Managing Technical Product Inputs''). The intended purpose of the Seepage Model for PA is to support: (1) PA; (2) Abstraction of Drift-Scale Seepage; and (3) Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR). Seepage into drifts is evaluated by applying numerical models with stochastic representations of hydrological properties and performing flow simulations with multiple realizations of the permeability field around the drift. The Seepage Model for PA uses the distribution of permeabilities derived from air injection testing in

  7. Enhanced battery model including temperature effects

    NARCIS (Netherlands)

    Rosca, B.; Wilkins, S.

    2013-01-01

    Within electric and hybrid vehicles, batteries are used to provide/buffer the energy required for driving. However, battery performance varies throughout the temperature range specific to automotive applications, and as such, models that describe this behaviour are required. This paper presents a dy

  8. Enhanced battery model including temperature effects

    NARCIS (Netherlands)

    Rosca, B.; Wilkins, S.

    2013-01-01

    Within electric and hybrid vehicles, batteries are used to provide/buffer the energy required for driving. However, battery performance varies throughout the temperature range specific to automotive applications, and as such, models that describe this behaviour are required. This paper presents a dy

  9. Enhanced battery model including temperature effects

    NARCIS (Netherlands)

    Rosca, B.; Wilkins, S.

    2013-01-01

    Within electric and hybrid vehicles, batteries are used to provide/buffer the energy required for driving. However, battery performance varies throughout the temperature range specific to automotive applications, and as such, models that describe this behaviour are required. This paper presents a

  10. Diverse hematological malignancies including hodgkin-like lymphomas develop in chimeric MHC class II transgenic mice.

    Directory of Open Access Journals (Sweden)

    Silke H Raffegerst

    Full Text Available A chimeric HLA-DR4-H2-E (DR4 homozygous transgenic mouse line spontaneously develops diverse hematological malignancies with high frequency (70%. The majority of malignancies were distributed equally between T and B cell neoplasms and included lymphoblastic T cell lymphoma (LTCL, lymphoblastic B cell lymphoma (LBCL, diffuse large B cell lymphoma (DLBCL, the histiocyte/T cell rich variant of DLBCL (DLBCL-HA/T cell rich DLBCL, splenic marginal zone lymphoma (SMZL, follicular B cell lymphoma (FBL and plasmacytoma (PCT. Most of these neoplasms were highly similar to human diseases. Also, some non-lymphoid malignancies such as acute myeloid leukemia (AML and histiocytic sarcoma were found. Interestingly, composite lymphomas, including Hodgkin-like lymphomas, were also detected that had CD30(+ Hodgkin/Reed-Sternberg (H/RS-like cells, representing a tumor type not previously described in mice. Analysis of microdissected H/RS-like cells revealed their origin as germinal center B cells bearing somatic hypermutations and, in some instances, crippled mutations, as described for human Hodgkin lymphoma (HL. Transgene integration in an oncogene was excluded as an exclusive driving force of tumorigenesis and age-related lymphoma development suggests a multi-step process. Thus, this DR4 line is a useful model to investigate common molecular mechanisms that may contribute to important neoplastic diseases in man.

  11. Experimental osteoarthritis models in mice.

    Science.gov (United States)

    Lorenz, Julia; Grässel, Susanne

    2014-01-01

    Osteoarthritis (OA) is a slowly progressing, degenerative disorder of synovial joints culminating in the irreversible destruction of articular cartilage and subchondral bone. It affects almost everyone over the age of 65 and influences life quality of affected individuals with enormous costs to the health care system. Current therapeutic strategies seek to ameliorate pain and increase mobility; however, to date none of them halts disease progression or regenerates damaged cartilage or bone. Thus, there is an ultimate need for the development of new, noninvasive treatments that could substitute joint replacement for late- or end-stage patients. Therefore, osteoarthritis animal models for mimicking of all OA features are important. Mice develop an OA pathology that is comparable to humans, rapidly develop OA due to the short lifetime and show reproducible OA symptoms. They provide a versatile and widely used animal model for analyzing molecular mechanisms of OA pathology. One major advantage over large animal models is the availability of knockout or transgenic mice strains to examine genetic predispositions/contributions to OA.In this chapter, we describe three widely used instability-inducing murine osteoarthritis models. The most common two methods for surgical induction are: (1) destabilization of the medial meniscus (DMM) and (2) anterior cruciate ligament transection (ACLT). In the DMM model, the medial meniscotibial ligament is transected while in the ACLT model the anterior cruciate ligament is destroyed. In the third, chemical induced instability method, intraarticular collagenase is injected into the knee joint. Intraarticular collagenase weakens articular ligaments which cause instability of the joint, and full-blown OA develops within 6 weeks. For morphological evaluation, we correspond mainly to the recommendations of OARSI for histological assessment of osteoarthritis in mouse. For statistical evaluation summed or mean scores of all four knee areas

  12. [Model of meningococcal sepsis in mice].

    Science.gov (United States)

    Krasnoproshina, L I; Ermakova, L G; Belova, T N; Filippov, Iu V; Efimov, D D

    1978-11-01

    The authors studied a possibility of obtaining experimental meningococcus sepsis model on mice. The use of cyclophosphane, iron compounds, yolk medium produced no significant organism. When 4--5% mucine was injected intraperitoneally together with meningococcus culture mice died with sepsis phenomena. Differences were revealed in the sensitivity of linear and mongrel mice to meningococcus infection--AKR mice proved to be more sensitive. At the same time it was found that mongrel mice weighing from 10 to 12 g could be used to induce meningococcus sepsis.

  13. HdhQ111 Mice Exhibit Tissue Specific Metabolite Profiles that Include Striatal Lipid Accumulation.

    Directory of Open Access Journals (Sweden)

    Jeffrey B Carroll

    Full Text Available The HTT CAG expansion mutation causes Huntington's Disease and is associated with a wide range of cellular consequences, including altered metabolism. The mutant allele is expressed widely, in all tissues, but the striatum and cortex are especially vulnerable to its effects. To more fully understand this tissue-specificity, early in the disease process, we asked whether the metabolic impact of the mutant CAG expanded allele in heterozygous B6.HdhQ111/+ mice would be common across tissues, or whether tissues would have tissue-specific responses and whether such changes may be affected by diet. Specifically, we cross-sectionally examined steady state metabolite concentrations from a range of tissues (plasma, brown adipose tissue, cerebellum, striatum, liver, white adipose tissue, using an established liquid chromatography-mass spectrometry pipeline, from cohorts of 8 month old mutant and wild-type littermate mice that were fed one of two different high-fat diets. The differential response to diet highlighted a proportion of metabolites in all tissues, ranging from 3% (7/219 in the striatum to 12% (25/212 in white adipose tissue. By contrast, the mutant CAG-expanded allele primarily affected brain metabolites, with 14% (30/219 of metabolites significantly altered, compared to wild-type, in striatum and 11% (25/224 in the cerebellum. In general, diet and the CAG-expanded allele both elicited metabolite changes that were predominantly tissue-specific and non-overlapping, with evidence for mutation-by-diet interaction in peripheral tissues most affected by diet. Machine-learning approaches highlighted the accumulation of diverse lipid species as the most genotype-predictive metabolite changes in the striatum. Validation experiments in cell culture demonstrated that lipid accumulation was also a defining feature of mutant HdhQ111 striatal progenitor cells. Thus, metabolite-level responses to the CAG expansion mutation in vivo were tissue specific and

  14. Dynamic hysteresis modeling including skin effect using diffusion equation model

    Science.gov (United States)

    Hamada, Souad; Louai, Fatima Zohra; Nait-Said, Nasreddine; Benabou, Abdelkader

    2016-07-01

    An improved dynamic hysteresis model is proposed for the prediction of hysteresis loop of electrical steel up to mean frequencies, taking into account the skin effect. In previous works, the analytical solution of the diffusion equation for low frequency (DELF) was coupled with the inverse static Jiles-Atherton (JA) model in order to represent the hysteresis behavior for a lamination. In the present paper, this approach is improved to ensure the reproducibility of measured hysteresis loops at mean frequency. The results of simulation are compared with the experimental ones. The selected results for frequencies 50 Hz, 100 Hz, 200 Hz and 400 Hz are presented and discussed.

  15. Dynamic hysteresis modeling including skin effect using diffusion equation model

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, Souad, E-mail: souadhamada@yahoo.fr [LSP-IE: Research Laboratory, Electrical Engineering Department, University of Batna, 05000 Batna (Algeria); Louai, Fatima Zohra, E-mail: fz_louai@yahoo.com [LSP-IE: Research Laboratory, Electrical Engineering Department, University of Batna, 05000 Batna (Algeria); Nait-Said, Nasreddine, E-mail: n_naitsaid@yahoo.com [LSP-IE: Research Laboratory, Electrical Engineering Department, University of Batna, 05000 Batna (Algeria); Benabou, Abdelkader, E-mail: Abdelkader.Benabou@univ-lille1.fr [L2EP, Université de Lille1, 59655 Villeneuve d’Ascq (France)

    2016-07-15

    An improved dynamic hysteresis model is proposed for the prediction of hysteresis loop of electrical steel up to mean frequencies, taking into account the skin effect. In previous works, the analytical solution of the diffusion equation for low frequency (DELF) was coupled with the inverse static Jiles-Atherton (JA) model in order to represent the hysteresis behavior for a lamination. In the present paper, this approach is improved to ensure the reproducibility of measured hysteresis loops at mean frequency. The results of simulation are compared with the experimental ones. The selected results for frequencies 50 Hz, 100 Hz, 200 Hz and 400 Hz are presented and discussed.

  16. Unsteady panel method for complex configurations including wake modeling

    CSIR Research Space (South Africa)

    Van Zyl, Lourens H

    2008-01-01

    Full Text Available implementations of the DLM are however not very versatile in terms of geometries that can be modeled. The ZONA6 code offers a versatile surface panel body model including a separated wake model, but uses a pressure panel method for lifting surfaces. This paper...

  17. Modeling Electric Double-Layers Including Chemical Reaction Effects

    DEFF Research Database (Denmark)

    Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

    2014-01-01

    A physicochemical and numerical model for the transient formation of an electric double-layer between an electrolyte and a chemically-active flat surface is presented, based on a finite elements integration of the nonlinear Nernst-Planck-Poisson model including chemical reactions. The model works...

  18. Circuit Modeling of a MEMS Varactor Including Dielectric Charging Dynamics

    Science.gov (United States)

    Giounanlis, P.; Andrade-Miceli, D.; Gorreta, S.; Pons-Nin, J.; Dominguez-Pumar, M.; Blokhina, E.

    2016-10-01

    Electrical models for MEMS varactors including the effect of dielectric charging dynamics are not available in commercial circuit simulators. In this paper a circuit model using lumped ideal elements available in the Cadence libraries and a basic Verilog-A model, has been implemented. The model has been used to simulate the dielectric charging in function of time and its effects over the MEMS capacitance value.

  19. Including investment risk in large-scale power market models

    DEFF Research Database (Denmark)

    Lemming, Jørgen Kjærgaard; Meibom, P.

    2003-01-01

    can be included in large-scale partial equilibrium models of the power market. The analyses are divided into a part about risk measures appropriate for power market investors and a more technical part about the combination of a risk-adjustment model and a partial-equilibrium model. To illustrate......Long-term energy market models can be used to examine investments in production technologies, however, with market liberalisation it is crucial that such models include investment risks and investor behaviour. This paper analyses how the effect of investment risk on production technology selection...... the analyses quantitatively, a framework based on an iterative interaction between the equilibrium model and a separate risk-adjustment module was constructed. To illustrate the features of the proposed modelling approach we examined how uncertainty in demand and variable costs affects the optimal choice...

  20. Progressive IRP Models for Power Resources Including EPP

    Directory of Open Access Journals (Sweden)

    Yiping Zhu

    2017-01-01

    Full Text Available In the view of optimizing regional power supply and demand, the paper makes effective planning scheduling of supply and demand side resources including energy efficiency power plant (EPP, to achieve the target of benefit, cost, and environmental constraints. In order to highlight the characteristics of different supply and demand resources in economic, environmental, and carbon constraints, three planning models with progressive constraints are constructed. Results of three models by the same example show that the best solutions to different models are different. The planning model including EPP has obvious advantages considering pollutant and carbon emission constraints, which confirms the advantages of low cost and emissions of EPP. The construction of progressive IRP models for power resources considering EPP has a certain reference value for guiding the planning and layout of EPP within other power resources and achieving cost and environmental objectives.

  1. Modeling heart rate variability including the effect of sleep stages

    Science.gov (United States)

    Soliński, Mateusz; Gierałtowski, Jan; Żebrowski, Jan

    2016-02-01

    We propose a model for heart rate variability (HRV) of a healthy individual during sleep with the assumption that the heart rate variability is predominantly a random process. Autonomic nervous system activity has different properties during different sleep stages, and this affects many physiological systems including the cardiovascular system. Different properties of HRV can be observed during each particular sleep stage. We believe that taking into account the sleep architecture is crucial for modeling the human nighttime HRV. The stochastic model of HRV introduced by Kantelhardt et al. was used as the initial starting point. We studied the statistical properties of sleep in healthy adults, analyzing 30 polysomnographic recordings, which provided realistic information about sleep architecture. Next, we generated synthetic hypnograms and included them in the modeling of nighttime RR interval series. The results of standard HRV linear analysis and of nonlinear analysis (Shannon entropy, Poincaré plots, and multiscale multifractal analysis) show that—in comparison with real data—the HRV signals obtained from our model have very similar properties, in particular including the multifractal characteristics at different time scales. The model described in this paper is discussed in the context of normal sleep. However, its construction is such that it should allow to model heart rate variability in sleep disorders. This possibility is briefly discussed.

  2. A hydrodynamic model for granular material flows including segregation effects

    Science.gov (United States)

    Gilberg, Dominik; Klar, Axel; Steiner, Konrad

    2017-06-01

    The simulation of granular flows including segregation effects in large industrial processes using particle methods is accurate, but very time-consuming. To overcome the long computation times a macroscopic model is a natural choice. Therefore, we couple a mixture theory based segregation model to a hydrodynamic model of Navier-Stokes-type, describing the flow behavior of the granular material. The granular flow model is a hybrid model derived from kinetic theory and a soil mechanical approach to cover the regime of fast dilute flow, as well as slow dense flow, where the density of the granular material is close to the maximum packing density. Originally, the segregation model has been formulated by Thornton and Gray for idealized avalanches. It is modified and adapted to be in the preferred form for the coupling. In the final coupled model the segregation process depends on the local state of the granular system. On the other hand, the granular system changes as differently mixed regions of the granular material differ i.e. in the packing density. For the modeling process the focus lies on dry granular material flows of two particle types differing only in size but can be easily extended to arbitrary granular mixtures of different particle size and density. To solve the coupled system a finite volume approach is used. To test the model the rotational mixing of small and large particles in a tumbler is simulated.

  3. Synaptic channel model including effects of spike width variation

    OpenAIRE

    2015-01-01

    Synaptic Channel Model Including Effects of Spike Width Variation Hamideh Ramezani Next-generation and Wireless Communications Laboratory (NWCL) Department of Electrical and Electronics Engineering Koc University, Istanbul, Turkey Ozgur B. Akan Next-generation and Wireless Communications Laboratory (NWCL) Department of Electrical and Electronics Engineering Koc University, Istanbul, Turkey ABSTRACT An accu...

  4. A sonic boom propagation model including mean flow atmospheric effects

    Science.gov (United States)

    Salamone, Joe; Sparrow, Victor W.

    2012-09-01

    This paper presents a time domain formulation of nonlinear lossy propagation in onedimension that also includes the effects of non-collinear mean flow in the acoustic medium. The model equation utilized is an augmented Burgers equation that includes the effects of nonlinearity, geometric spreading, atmospheric stratification, and also absorption and dispersion due to thermoviscous and molecular relaxation effects. All elements of the propagation are implemented in the time domain and the effects of non-collinear mean flow are accounted for in each term of the model equation. Previous authors have presented methods limited to showing the effects of wind on ray tracing and/or using an effective speed of sound in their model equation. The present work includes the effects of mean flow for all terms included in the augmented Burgers equation with all of the calculations performed in the time-domain. The capability to include the effects of mean flow in the acoustic medium allows one to make predictions more representative of real-world atmospheric conditions. Examples are presented for nonlinear propagation of N-waves and shaped sonic booms. [Work supported by Gulfstream Aerospace Corporation.

  5. A model of Barchan dunes including lateral shear stress.

    Science.gov (United States)

    Schwämmle, V; Herrmann, H J

    2005-01-01

    Barchan dunes are found where sand availability is low and wind direction quite constant. The two dimensional shear stress of the wind field and the sand movement by saltation and avalanches over a barchan dune are simulated. The model with one dimensional shear stress is extended including surface diffusion and lateral shear stress. The resulting final shape is compared to the results of the model with a one dimensional shear stress and confirmed by comparison to measurements. We found agreement and improvements with respect to the model with one dimensional shear stress. Additionally, a characteristic edge at the center of the windward side is discovered which is also observed for big barchans. Diffusion effects reduce this effect for small dunes.

  6. Goldilocks Models of Higher-Dimensional Inflation (including modulus stabilization)

    CERN Document Server

    Burgess, C P; Hayman, Peter; Patil, Subodh P

    2016-01-01

    We explore the mechanics of inflation in simplified extra-dimensional models involving an inflaton interacting with the Einstein-Maxwell system in two extra dimensions. The models are Goldilocks-like in that they are just complicated enough to include a mechanism to stabilize the extra-dimensional size, yet simple enough to solve the full 6D field equations using basic tools. The solutions are not limited to the effective 4D regime with H m_KK, but when they do standard 4D fluctuation calculations need not apply. When in a 4D regime the solutions predict eta ~ 0 hence n_s ~ 0.96 and r ~ 0.096 and so are ruled out if tensor modes remain unseen. Analysis of general parameters is difficult without a full 6D fluctuation calculation.

  7. Kinetic models of gene expression including non-coding RNAs

    Science.gov (United States)

    Zhdanov, Vladimir P.

    2011-03-01

    In cells, genes are transcribed into mRNAs, and the latter are translated into proteins. Due to the feedbacks between these processes, the kinetics of gene expression may be complex even in the simplest genetic networks. The corresponding models have already been reviewed in the literature. A new avenue in this field is related to the recognition that the conventional scenario of gene expression is fully applicable only to prokaryotes whose genomes consist of tightly packed protein-coding sequences. In eukaryotic cells, in contrast, such sequences are relatively rare, and the rest of the genome includes numerous transcript units representing non-coding RNAs (ncRNAs). During the past decade, it has become clear that such RNAs play a crucial role in gene expression and accordingly influence a multitude of cellular processes both in the normal state and during diseases. The numerous biological functions of ncRNAs are based primarily on their abilities to silence genes via pairing with a target mRNA and subsequently preventing its translation or facilitating degradation of the mRNA-ncRNA complex. Many other abilities of ncRNAs have been discovered as well. Our review is focused on the available kinetic models describing the mRNA, ncRNA and protein interplay. In particular, we systematically present the simplest models without kinetic feedbacks, models containing feedbacks and predicting bistability and oscillations in simple genetic networks, and models describing the effect of ncRNAs on complex genetic networks. Mathematically, the presentation is based primarily on temporal mean-field kinetic equations. The stochastic and spatio-temporal effects are also briefly discussed.

  8. Progress Towards an LES Wall Model Including Unresolved Roughness

    Science.gov (United States)

    Craft, Kyle; Redman, Andrew; Aikens, Kurt

    2015-11-01

    Wall models used in large eddy simulations (LES) are often based on theories for hydraulically smooth walls. While this is reasonable for many applications, there are also many where the impact of surface roughness is important. A previously developed wall model has been used primarily for jet engine aeroacoustics. However, jet simulations have not accurately captured thick initial shear layers found in some experimental data. This may partly be due to nozzle wall roughness used in the experiments to promote turbulent boundary layers. As a result, the wall model is extended to include the effects of unresolved wall roughness through appropriate alterations to the log-law. The methodology is tested for incompressible flat plate boundary layers with different surface roughness. Correct trends are noted for the impact of surface roughness on the velocity profile. However, velocity deficit profiles and the Reynolds stresses do not collapse as well as expected. Possible reasons for the discrepancies as well as future work will be presented. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1053575. Computational resources on TACC Stampede were provided under XSEDE allocation ENG150001.

  9. A further review of inhalation studies with cigarette smoke and lung cancer in experimental animals, including transgenic mice.

    Science.gov (United States)

    Coggins, C R E

    2010-10-01

    The lack of an effective animal model for pulmonary carcinogenesis in smokers is a continuing problem for researchers trying to design Potentially Reduced Risk Products for those smokers who are either unwilling or unable to quit smoking. The major failing of inhalation assays with cigarette smoke in laboratory animals is that these assays produce only small percentages of animals with pulmonary tumors (e.g. adenomas, with the occasional adenocarcinoma), as opposed to the highly invasive carcinomas (e.g. small cell and squamous cell) seen in smokers. To update previous reviews on animal models, and to add different types of transgenic (Tg) mice to the review. Reviews were made of articles retrieved from PubMed and elsewhere. The addition of Tg mice to the arsenal of tests used for the evaluation of the carcinogenic potential of cigarettes did not result in any better understanding of the inability of such testing to reflect the epidemiological evidence for lung cancer in smokers. As in previous reviews on the subject, the best assay providing support for the epidemiology data is still the 5-month whole-body exposure of male A/J mice to a combination of mainstream/sidestream smoke, followed by a 4-month recovery.

  10. Numerical Modeling of Electroacoustic Logging Including Joule Heating

    Science.gov (United States)

    Plyushchenkov, Boris D.; Nikitin, Anatoly A.; Turchaninov, Victor I.

    It is well known that electromagnetic field excites acoustic wave in a porous elastic medium saturated with fluid electrolyte due to electrokinetic conversion effect. Pride's equations describing this process are written in isothermal approximation. Update of these equations, which allows to take influence of Joule heating on acoustic waves propagation into account, is proposed here. This update includes terms describing the initiation of additional acoustic waves excited by thermoelastic stresses and the heat conduction equation with right side defined by Joule heating. Results of numerical modeling of several problems of propagation of acoustic waves excited by an electric field source with and without consideration of Joule heating effect in their statements are presented. From these results, it follows that influence of Joule heating should be taken into account at the numerical simulation of electroacoustic logging and at the interpretation of its log data.

  11. Goldilocks models of higher-dimensional inflation (including modulus stabilization)

    Science.gov (United States)

    Burgess, C. P.; Enns, Jared J. H.; Hayman, Peter; Patil, Subodh P.

    2016-08-01

    We explore the mechanics of inflation within simplified extra-dimensional models involving an inflaton interacting with the Einstein-Maxwell system in two extra dimensions. The models are Goldilocks-like inasmuch as they are just complicated enough to include a mechanism to stabilize the extra-dimensional size (or modulus), yet simple enough to solve explicitly the full extra-dimensional field equations using only simple tools. The solutions are not restricted to the effective 4D regime with H ll mKK (the latter referring to the characteristic mass splitting of the Kaluza-Klein excitations) because the full extra-dimensional Einstein equations are solved. This allows an exploration of inflationary physics in a controlled calculational regime away from the usual four-dimensional lamp-post. The inclusion of modulus stabilization is important because experience with string models teaches that this is usually what makes models fail: stabilization energies easily dominate the shallow potentials required by slow roll and so open up directions to evolve that are steeper than those of the putative inflationary direction. We explore (numerically and analytically) three representative kinds of inflationary scenarios within this simple setup. In one the radion is trapped in an inflaton-dependent local minimum whose non-zero energy drives inflation. Inflation ends as this energy relaxes to zero when the inflaton finds its own minimum. The other two involve power-law scaling solutions during inflation. One of these is a dynamical attractor whose features are relatively insensitive to initial conditions but whose slow-roll parameters cannot be arbitrarily small; the other is not an attractor but can roll much more slowly, until eventually transitioning to the attractor. The scaling solutions can satisfy H > mKK, but when they do standard 4D fluctuation calculations need not apply. When in a 4D regime the solutions predict η simeq 0 and so r simeq 0.11 when ns simeq 0.96 and so

  12. Including spatial data in nutrient balance modelling on dairy farms

    Science.gov (United States)

    van Leeuwen, Maricke; van Middelaar, Corina; Stoof, Cathelijne; Oenema, Jouke; Stoorvogel, Jetse; de Boer, Imke

    2017-04-01

    The Annual Nutrient Cycle Assessment (ANCA) calculates the nitrogen (N) and phosphorus (P) balance at a dairy farm, while taking into account the subsequent nutrient cycles of the herd, manure, soil and crop components. Since January 2016, Dutch dairy farmers are required to use ANCA in order to increase understanding of nutrient flows and to minimize nutrient losses to the environment. A nutrient balance calculates the difference between nutrient inputs and outputs. Nutrients enter the farm via purchased feed, fertilizers, deposition and fixation by legumes (nitrogen), and leave the farm via milk, livestock, manure, and roughages. A positive balance indicates to which extent N and/or P are lost to the environment via gaseous emissions (N), leaching, run-off and accumulation in soil. A negative balance indicates that N and/or P are depleted from soil. ANCA was designed to calculate average nutrient flows on farm level (for the herd, manure, soil and crop components). ANCA was not designed to perform calculations of nutrient flows at the field level, as it uses averaged nutrient inputs and outputs across all fields, and it does not include field specific soil characteristics. Land management decisions, however, such as the level of N and P application, are typically taken at the field level given the specific crop and soil characteristics. Therefore the information that ANCA provides is likely not sufficient to support farmers' decisions on land management to minimize nutrient losses to the environment. This is particularly a problem when land management and soils vary between fields. For an accurate estimate of nutrient flows in a given farming system that can be used to optimize land management, the spatial scale of nutrient inputs and outputs (and thus the effect of land management and soil variation) could be essential. Our aim was to determine the effect of the spatial scale of nutrient inputs and outputs on modelled nutrient flows and nutrient use efficiencies

  13. Craniofacial Statistical Deformation Models of Wild-type mice and Crouzon mice

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Darvann, Tron Andre; Ersbøll, Bjarne Kjær

    2007-01-01

    of Micro CT scannings of the heads of wild-type (normal) mice and Crouzon mice were investigated. Statistical deformation models were built to assess the anatomical differences between the groups, as well as the within-group anatomical variation. Following the approach by Rueckert et al. we built an atlas...

  14. A Discrete Velocity Traffic Kinetic Model Including Desired Speed

    Directory of Open Access Journals (Sweden)

    Shoufeng Lu

    2013-05-01

    Full Text Available We introduce the desired speed variable into the table of games and formulate a new table of games and the corresponding discrete traffic kinetic model. We use the hybrid programming technique of VB and MATLAB to develop the program. Lastly, we compared the proposed model result and the detector data. The results show that the proposed model can describe the traffic flow evolution.

  15. Semi-holographic model including the radiation component

    CERN Document Server

    del Campo, Sergio; Magaña, Juan; Villanueva, J R

    2014-01-01

    In this letter we study the semi holographic model which corresponds to the radiative version of the model proposed by Zhang et al. (Phys. Lett. B 694 (2010), 177) and revisited by C\\'ardenas et al. (Mon. Not. Roy. Astron. Soc. 438 (2014), 3603). This inclusion makes the model more realistic, so allows us to test it with current observational data and then answer if the inconsistency reported by C\\'ardenas et al. is relaxed.

  16. A Fault Evolution Model Including the Rupture Dynamic Simulation

    Science.gov (United States)

    Wu, Y.; Chen, X.

    2011-12-01

    We perform a preliminary numerical simulation of seismicity and stress evolution along a strike-slip fault in a 3D elastic half space. Following work of Ben-Zion (1996), the fault geometry is devised as a vertical plane which is about 70 km long and 17 km wide, comparable to the size of San Andreas Fault around Parkfield. The loading mechanism is described by "backslip" method. The fault failure is governed by a static/kinetic friction law, and induced stress transfer is calculated with Okada's static solution. In order to track the rupture propagation in detail, we allow induced stress to propagate through the medium at the shear wave velocity by introducing a distance-dependent time delay to responses to stress changes. Current simulation indicates small to moderate earthquakes following the Gutenberg-Richter law and quasi-periodical characteristic large earthquakes, which are consistent with previous work by others. Next we will consider introducing a more realistic friction law, namely, the laboratory-derived rate- and state- dependent law, which can simulate more realistic and complicated sliding behavior such as the stable and unstable slip, the aseismic sliding and the slip nucleation process. In addition, the long duration of aftershocks is expected to be reproduced due to this time-dependent friction law, which is not available in current seismicity simulation. The other difference from previous work is that we are trying to include the dynamic ruptures in this study. Most previous study on seismicity simulation is based on the static solution when dealing with failure induced stress changes. However, studies of numerical simulation of rupture dynamics have revealed lots of important details which are missing in the quasi-static/quasi- dynamic simulation. For example, dynamic simulations indicate that the slip on the ground surface becomes larger if the dynamic rupture process reaches the free surface. The concentration of stress on the propagating crack

  17. Evacuation modeling including traveler information and compliance behavior

    NARCIS (Netherlands)

    Pel, A.J.; Hoogendoorn, S.P.; Bliemer, M.C.J.

    2010-01-01

    Traffic simulation models are often used to support decisions when planning an evacuation. Scenario analyses based on these models then typically focus on traffic dynamics and the effect of traffic control measures in order to locate possible bottlenecks and predict evacuation times. A clear approac

  18. Global atmospheric model for mercury including oxidation by bromine atoms

    Directory of Open Access Journals (Sweden)

    C. D. Holmes

    2010-12-01

    Full Text Available Global models of atmospheric mercury generally assume that gas-phase OH and ozone are the main oxidants converting Hg0 to HgII and thus driving mercury deposition to ecosystems. However, thermodynamic considerations argue against the importance of these reactions. We demonstrate here the viability of atomic bromine (Br as an alternative Hg0 oxidant. We conduct a global 3-D simulation with the GEOS-Chem model assuming gas-phase Br to be the sole Hg0 oxidant (Hg + Br model and compare to the previous version of the model with OH and ozone as the sole oxidants (Hg + OH/O3 model. We specify global 3-D Br concentration fields based on our best understanding of tropospheric and stratospheric Br chemistry. In both the Hg + Br and Hg + OH/O3 models, we add an aqueous photochemical reduction of HgII in cloud to impose a tropospheric lifetime for mercury of 6.5 months against deposition, as needed to reconcile observed total gaseous mercury (TGM concentrations with current estimates of anthropogenic emissions. This added reduction would not be necessary in the Hg + Br model if we adjusted the Br oxidation kinetics downward within their range of uncertainty. We find that the Hg + Br and Hg + OH/O3 models are equally capable of reproducing the spatial distribution of TGM and its seasonal cycle at northern mid-latitudes. The Hg + Br model shows a steeper decline of TGM concentrations from the tropics to southern mid-latitudes. Only the Hg + Br model can reproduce the springtime depletion and summer rebound of TGM observed at polar sites; the snowpack component of GEOS-Chem suggests that 40% of HgII deposited to snow in the Arctic is transferred to the ocean and land reservoirs, amounting to a net deposition flux to the Arctic of 60 Mg a−1. Summertime events of depleted Hg0 at Antarctic sites due to subsidence are much better simulated by

  19. Imunocompetent Mice Model for Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Denise Gonçalves

    2012-01-01

    Full Text Available Dengue fever is a noncontagious infectious disease caused by dengue virus (DENV. DENV belongs to the family Flaviviridae, genus Flavivirus, and is classified into four antigenically distinct serotypes: DENV-1, DENV-2, DENV-3, and DENV-4. The number of nations and people affected has increased steadily and today is considered the most widely spread arbovirus (arthropod-borne viral disease in the world. The absence of an appropriate animal model for studying the disease has hindered the understanding of dengue pathogenesis. In our study, we have found that immunocompetent C57BL/6 mice infected intraperitoneally with DENV-1 presented some signs of dengue disease such as thrombocytopenia, spleen hemorrhage, liver damage, and increase in production of IFNγ and TNFα cytokines. Moreover, the animals became viremic and the virus was detected in several organs by real-time RT-PCR. Thus, this animal model could be used to study mechanism of dengue virus infection, to test antiviral drugs, as well as to evaluate candidate vaccines.

  20. Pilot Wave model that includes creation and annihilation of particles

    CERN Document Server

    Sverdlov, Roman

    2010-01-01

    The purpose of this paper is to come up with a Pilot Wave model of quantum field theory that incorporates particle creation and annihilation without sacrificing determinism. This has been previously attempted in an article by the same author titled "Incorporating particle creation and annihilation in Pilot Wave model", in a much less satisfactory way. In this paper I would like to "clean up" some of the things. In particular, I would like to get rid of a very unnatural concept of "visibility" of particles, which makes the model much simpler. On the other hand, I would like to add a mechanism for decoherence, which was absent in the previous version.

  1. Global atmospheric model for mercury including oxidation by bromine atoms

    Directory of Open Access Journals (Sweden)

    C. D. Holmes

    2010-08-01

    Full Text Available Global models of atmospheric mercury generally assume that OH and ozone are the main oxidants converting Hg0 to HgII and thus driving mercury deposition to ecosystems. However, thermodynamic considerations argue against the importance of these reactions. We demonstrate here the viability of atomic bromine (Br as an alternative Hg0 oxidant. We conduct a global 3-D simulation with the GEOS-Chem model assuming Br to be the sole Hg0 oxidant (Hg + Br model and compare to the previous version of the model with OH and ozone as the sole oxidants (Hg + OH/O3 model. We specify global 3-D Br concentration fields based on our best understanding of tropospheric and stratospheric Br chemistry. In both the Hg + Br and Hg + OH/O3 models, we add an aqueous photochemical reduction of HgII in cloud to impose a tropospheric lifetime for mercury of 6.5 months against deposition, as needed to reconcile observed total gaseous mercury (TGM concentrations with current estimates of anthropogenic emissions. This added reduction would not be necessary in the Hg + Br model if we adjusted the Br oxidation kinetics downward within their range of uncertainty. We find that the Hg + Br and Hg + OH/O3 models are equally capable of reproducing the spatial distribution of TGM and its seasonal cycle at northern mid-latitudes. The Hg + Br model shows a steeper decline of TGM concentrations from the tropics to southern mid-latitudes. Only the Hg + Br model can reproduce the springtime depletion and summer rebound of TGM observed at polar sites; the snowpack component of GEOS-Chem suggests that 40% of HgII deposited to snow in the Arctic is transferred to the ocean and land reservoirs, amounting to a net deposition flux of 60 Mg a−1. Summertime events of depleted Hg0 at Antarctic sites due to subsidence are much better simulated by the Hg + Br model. Model

  2. An Intracellular Calcium Oscillations Model Including Mitochondrial Calcium Cycling

    Institute of Scientific and Technical Information of China (English)

    SHI Xiao-Min; LIU Zeng-Rong

    2005-01-01

    @@ Calcium is a ubiquitous second messenger. Mitochondria contributes significantly to intracellular Ca2+ dynamics.The experiment of Kaftan et al. [J. Biol. Chem. 275(2000) 25465] demonstrated that inhibiting mitochondrial Ca2+ uptake can reduce the frequency of cytosolic Ca2+ concentration oscillations of gonadotropes. By considering the mitochondrial Ca2+ cycling we develop a three-variable model of intracellular Ca2+ oscillations based on the models of Atri et al. [Biophys. J. 65 (1993) 1727] and Falcke et al. [Biophys. J. 77 (1999) 37]. The model reproduces the fact that mitochondrial Ca2+ cycling increases the frequency of cytosolic Ca2+ oscillations, which accords with Kaftan's results. Moreover the model predicts that when the mitochondria overload with Ca2+, the cytosolic Ca2+ oscillations vanish, which may trigger apoptosis.

  3. Novel, high incidence exercise-induced muscle bleeding model in hemophilia B mice

    DEFF Research Database (Denmark)

    Tranholm, M.; Kristensen, Annemarie Thuri; Broberg, M. L.

    2015-01-01

    INTRODUCTION: Muscle hematomas are the second most common complication of hemophilia and insufficient treatment may result in serious and even life-threatening complications. Hemophilic dogs and rats do experience spontaneous muscle bleeding, but currently, no experimental animal model is available...... specifically investigating spontaneous muscle bleeds in a hemophilic setting. AIM: The objective of this study was to develop a model of spontaneous muscle bleeds in hemophilia B mice. We hypothesized that treadmill exercise would induce muscle bleeds in hemophilia B mice but not in normal non-hemophilic mice...... and that treatment with recombinant factor IX (rFIX) before treadmill exercise could prevent the occurrence of pathology. METHODS: A total of 203 mice (123 F9-KO and 80 C57BL/6NTac) were included in three separate studies: (i) the model implementation study investigating the bleeding pattern in hemophilia B mice...

  4. Cement-aggregate compatibility and structure property relationships including modelling

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, H.M.; Xi, Y.

    1993-07-15

    The role of aggregate, and its interface with cement paste, is discussed with a view toward establishing models that relate structure to properties. Both short (nm) and long (mm) range structure must be considered. The short range structure of the interface depends not only on the physical distribution of the various phases, but also on moisture content and reactivity of aggregate. Changes that occur on drying, i.e. shrinkage, may alter the structure which, in turn, feeds back to alter further drying and shrinkage. The interaction is dynamic, even without further hydration of cement paste, and the dynamic characteristic must be considered in order to fully understand and model its contribution to properties. Microstructure and properties are two subjects which have been pursued somewhat separately. This review discusses both disciplines with a view toward finding common research goals in the future. Finally, comment is made on possible chemical reactions which may occur between aggregate and cement paste.

  5. Including lateral interactions into microkinetic models of catalytic reactions

    DEFF Research Database (Denmark)

    Hellman, Anders; Honkala, Johanna Karoliina

    2007-01-01

    In many catalytic reactions lateral interactions between adsorbates are believed to have a strong influence on the reaction rates. We apply a microkinetic model to explore the effect of lateral interactions and how to efficiently take them into account in a simple catalytic reaction. Three differ...... different approximations are investigated: site, mean-field, and quasichemical approximations. The obtained results are compared to accurate Monte Carlo numbers. In the end, we apply the approximations to a real catalytic reaction, namely, ammonia synthesis....

  6. Comparison of Joint Modeling Approaches Including Eulerian Sliding Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lomov, I; Antoun, T; Vorobiev, O

    2009-12-16

    Accurate representation of discontinuities such as joints and faults is a key ingredient for high fidelity modeling of shock propagation in geologic media. The following study was done to improve treatment of discontinuities (joints) in the Eulerian hydrocode GEODYN (Lomov and Liu 2005). Lagrangian methods with conforming meshes and explicit inclusion of joints in the geologic model are well suited for such an analysis. Unfortunately, current meshing tools are unable to automatically generate adequate hexahedral meshes for large numbers of irregular polyhedra. Another concern is that joint stiffness in such explicit computations requires significantly reduced time steps, with negative implications for both the efficiency and quality of the numerical solution. An alternative approach is to use non-conforming meshes and embed joint information into regular computational elements. However, once slip displacement on the joints become comparable to the zone size, Lagrangian (even non-conforming) meshes could suffer from tangling and decreased time step problems. The use of non-conforming meshes in an Eulerian solver may alleviate these difficulties and provide a viable numerical approach for modeling the effects of faults on the dynamic response of geologic materials. We studied shock propagation in jointed/faulted media using a Lagrangian and two Eulerian approaches. To investigate the accuracy of this joint treatment the GEODYN calculations have been compared with results from the Lagrangian code GEODYN-L which uses an explicit treatment of joints via common plane contact. We explore two approaches to joint treatment in the code, one for joints with finite thickness and the other for tight joints. In all cases the sliding interfaces are tracked explicitly without homogenization or blending the joint and block response into an average response. In general, rock joints will introduce an increase in normal compliance in addition to a reduction in shear strength. In the

  7. Neighboring extremal optimal control design including model mismatch errors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T.J. [Sandia National Labs., Albuquerque, NM (United States); Hull, D.G. [Texas Univ., Austin, TX (United States). Dept. of Aerospace Engineering and Engineering Mechanics

    1994-11-01

    The mismatch control technique that is used to simplify model equations of motion in order to determine analytic optimal control laws is extended using neighboring extremal theory. The first variation optimal control equations are linearized about the extremal path to account for perturbations in the initial state and the final constraint manifold. A numerical example demonstrates that the tuning procedure inherent in the mismatch control method increases the performance of the controls to the level of a numerically-determined piecewise-linear controller.

  8. Double pendulum model for tennis stroke including a collision process

    CERN Document Server

    Youn, Sun-Hyun

    2015-01-01

    By means of adding a collision process between the ball and racket in double pendulum model, we analyzed the tennis stroke. It is possible that the speed of the rebound ball does not simply depend on the angular velocity of the racket, and higher angular velocity sometimes gives lower ball speed. We numerically showed that the proper time lagged racket rotation increases the speed of the rebound ball by 20%. We also showed that the elbow should move in order to add the angular velocity of the racket.

  9. The Use of L-sIDOL Transgenic Mice as a Murine Model to Study Hypercholesterolemia and Atherosclerosis.

    Science.gov (United States)

    Zerenturk, Eser J; Calkin, Anna C

    2017-01-01

    There are many advantages to the use of mice as a model to study the regulation of cholesterol metabolism. Common models of hypercholesterolemia include low-density lipoprotein receptor deficient (LDLR -/-) mice and apolipoprotein E deficient (ApoE) -/- mice. Herein, we describe the recently generated mouse model, L-sIDOL Tg mice, which express a dominant active form of Inducible Degrader Of the Low-density lipoprotein receptor (IDOL) in a liver-specific manner. This murine model offers significant advantages over previously established models for the study of hypercholesterolemia and atherosclerosis.

  10. Modelling of Dual-Junction Solar Cells including Tunnel Junction

    Directory of Open Access Journals (Sweden)

    Abdelaziz Amine

    2013-01-01

    Full Text Available Monolithically stacked multijunction solar cells based on III–V semiconductors materials are the state-of-art of approach for high efficiency photovoltaic energy conversion, in particular for space applications. The individual subcells of the multi-junction structure are interconnected via tunnel diodes which must be optically transparent and connect the component cells with a minimum electrical resistance. The quality of these diodes determines the output performance of the solar cell. The purpose of this work is to contribute to the investigation of the tunnel electrical resistance of such a multi-junction cell through the analysis of the current-voltage (J-V characteristics under illumination. Our approach is based on an equivalent circuit model of a diode for each subcell. We examine the effect of tunnel resistance on the performance of a multi-junction cell using minimization of the least squares technique.

  11. Human sperm chromatin stabilization: a proposed model including zinc bridges.

    Science.gov (United States)

    Björndahl, Lars; Kvist, Ulrik

    2010-01-01

    The primary focus of this review is to challenge the current concepts on sperm chromatin stability. The observations (i) that zinc depletion at ejaculation allows a rapid and total sperm chromatin decondensation without the addition of exogenous disulfide cleaving agents and (ii) that the human sperm chromatin contains one zinc for every protamine for every turn of the DNA helix suggest an alternative model for sperm chromatin structure may be plausible. An alternative model is therefore proposed, that the human spermatozoon could at ejaculation have a rapidly reversible zinc dependent chromatin stability: Zn(2+) stabilizes the structure and prevents the formation of excess disulfide bridges by a single mechanism, the formation of zinc bridges with protamine thiols of cysteine and potentially imidazole groups of histidine. Extraction of zinc enables two biologically totally different outcomes: immediate decondensation if chromatin fibers are concomitantly induced to repel (e.g. by phosphorylation in the ooplasm); otherwise freed thiols become committed into disulfide bridges creating a superstabilized chromatin. Spermatozoa in the zinc rich prostatic fluid (normally the first expelled ejaculate fraction) represent the physiological situation. Extraction of chromatin zinc can be accomplished by the seminal vesicular fluid. Collection of the ejaculate in one single container causes abnormal contact between spermatozoa and seminal vesicular fluid affecting the sperm chromatin stability. There are men in infertile couples with low content of sperm chromatin zinc due to loss of zinc during ejaculation and liquefaction. Tests for sperm DNA integrity may give false negative results due to decreased access for the assay to the DNA in superstabilized chromatin.

  12. Global model including multistep ionizations in helium plasmas

    Science.gov (United States)

    Oh, Seung-Ju; Lee, Hyo-Chang; Chung, Chin-Wook

    2016-12-01

    Particle and power balance equations including stepwise ionizations are derived and solved in helium plasmas. In the balance equations, two metastable states (21S1 in singlet and 23S1 triplet) are considered and the followings are obtained. The plasma density linearly increases and the electron temperature is relatively in a constant value against the absorbed power. It is also found that the contribution to multi-step ionization with respect to the single-step ionization is in the range of 8%-23%, as the gas pressure increases from 10 mTorr to 100 mTorr. Compared to the results in the argon plasma, there is little variation in the collisional energy loss per electron-ion pair created (ɛc) with absorbed power and gas pressure due to the small collision cross section and higher inelastic collision threshold energy.

  13. Inbred and outbred mice have equivalent variability in a cockroach allergen-induced model of asthma.

    Science.gov (United States)

    Vaickus, Louis J; Bouchard, Jacqueline; Kim, Jiyoun; Natarajan, Sudha; Remick, Daniel G

    2010-12-01

    Outbred mice traditionally are considered to display high variability, thereby limiting their use in some studies. Researchers frequently are encouraged to use inbred strains of mice because of the greater homogeneity of these experimental animals. We compared the pulmonary inflammatory response of inbred BALB/cJ mice to that of outbred HSD-ICR mice by measuring multiple variables, including cytokines, chemokines, number of pulmonary inflammatory cells, and respiratory parameters. Cockroach allergens induced significant pulmonary inflammation in both BALB and ICR mice. Our comparisons of the coefficients of variance for 148 discrete data sets for each strain or stock indicated that BALB and ICR mice have roughly equivalent intrastrain or -stock variability in our model of asthma-like pulmonary inflammation. The average coefficient of variance, calculated as the ratio of the SD to the mean of a data set, was 0.35 ± 0.34 for BALB mice compared with 0.31 ± 0.32 for ICR mice. In conclusion, inbred BALB and outbred ICR mice have roughly equivalent intrastrain or -stock variability in a murine model of asthma-like pulmonary inflammation.

  14. Modelization of a water tank including a PCM module

    Energy Technology Data Exchange (ETDEWEB)

    Ibanez, Manuel [Dept. de Medi Ambient i Ciencies del Sol, Universitat de Lleida, Rovira Roure 191, 25198 Lleida (Spain); Cabeza, Luisa F.; Sole, Cristian; Roca, Joan; Nogues, Miquel [Dept. d' Informatica i Eng. Industrial, Universitat de Lleida, Jaume II 69, 25001 Lleida (Spain)

    2006-08-15

    The reduction of CO{sub 2} emissions is a key component for today's governments. Therefore, implementation of more and more systems with renewable energies is necessary. Solar systems for single family houses or residential buildings need a big water tank that many times is not easy to locate. This paper studies the modelization of a new technology where PCM modules are implemented in domestic hot water tanks to reduce their size without reducing the energy stored. A new TRNSYS component, based in the already existing TYPE 60, was developed, called TYPE 60PCM. After tuning the new component with experimental results, two more experiences were developed to validate the simulation of a water tank with two cylindrical PCM modules using type 60PCM, the cooldown and reheating experiments. Concordance between experimental and simulated data was very good. Since the new TRNSYS component was developed to simulate full solar systems, comparison of experimental results from a pilot plant solar system with simulations were performed, and they confirmed that the type 60PCM is a powerful tool to evaluate the performance of PCM modules in water tanks. (author)

  15. CD38 gene knockout juvenile mice: a model of oxytocin signal defects in autism.

    Science.gov (United States)

    Higashida, Haruhiro; Yokoyama, Shigeru; Munesue, Toshio; Kikuchi, Mitsuru; Minabe, Yoshio; Lopatina, Olga

    2011-01-01

    Oxytocin (OXT) in the hypothalamus is the biological basis of social recognition, trust, and bonding. We showed that CD38, a leukaemia cell marker, plays an important role in the hypothalamus in the process of OXT release in adult mice. Disruption of Cd38 (Cd38(-/-)) produced impairment of maternal behavior and male social recognition in mice, similar to the behavior observed in Oxt and OXT receptor (Oxtr) gene knockout (Oxt(-/-) and Oxtr(-/-), respectively) mice. Locomotor activity induced by separation from the dam was higher and the number of ultrasonic vocalization (USV) calls was lower in Cd38(-/-) than Cd38(+/+) pups. These phenotypes seemed to be caused by the high plasma OXT levels during development from neonates to 3-week-old juvenile mice. ADP-ribosyl cyclase activity was markedly lower in the knockout mice from birth, suggesting that weaning for mice is a critical time window of differentiating plasma OXT. Contribution by breastfeeding was an important exogenous source for regulating plasma OXT before weaning by the presence of OXT in milk and the dam's mammary glands. The dissimilarity of Cd38(-/-) infant behaviour to Oxt(-/-) or Oxtr(-/-) mice can be explained partly by this exogenous source of OXT. These results suggest that secretion of OXT into the brain in a CD38-dependent manner may play an important role in the development of social behavior, and mice with OXT signalling deficiency, including Cd38(-/-), Oxt(-/-) and Oxtr(-/-) mice are good animal models for developmental disorders, such as autism.

  16. A novel mice model of metabolic syndrome: the high-fat-high-fructose diet-fed ICR mice

    Science.gov (United States)

    Zhuhua, Zhang; Zhiquan, Wang; Zhen, Yang; Yixin, Niu; Weiwei, Zhang; Xiaoyong, Li; Yueming, Liu; Hongmei, Zhang; Li, Qin; Qing, Su

    2015-01-01

    Currently, the metabolic syndrome (MS) is occurring at growing rates worldwide, raising extensive concerns on the mechanisms and therapeutic interventions for this disorder. Herein, we described a novel method of establishing MS model in rodents. Male Institute of Cancer Research (ICR) mice were fed with high-fat-high-fructose (HFHF) diet or normal chow (NC) respectively for 12 weeks. Metabolic phenotypes were assessed by glucose tolerance test, insulin tolerance test and hyperinsulinemic-euglycemic clamp. Blood pressure was measured by a tail-cuff system. At the end of the experiment, mice were sacrificed, and blood and tissues were harvested for subsequent analysis. Serum insulin levels were measured by ELISA, and lipid profiles were determined biochemically. The HFHF diet-fed ICR mice exhibited obvious characteristics of the components of MS, including obvious obesity, severe insulin resistance, hyperinsulinemia, dislipidemia, significant hypertension and hyperuricemia. Our data suggest that HFHF diet-fed ICR mice may be a robust and efficient animal model that could well mimic the basic pathogenesis of human MS. PMID:26134356

  17. Assessment of behaviors modeling aspects of schizophrenia in Csmd1 mutant mice.

    Directory of Open Access Journals (Sweden)

    Margaret G Distler

    Full Text Available Schizophrenia is a debilitating psychotic disorder that affects up to 1.5% of the population worldwide. Two recent studies in humans identified genome-wide significant associations between schizophrenia and single-nucleotide polymorphisms (SNPs in an intron of CSMD1. The effect of deleting CSMD1 on mouse behavior is unknown. The present study utilized mice with a mutant Csmd1 allele in which the first exon had been ablated (KO mice. All Csmd1 transcripts that included the first exon were absent in the brains of KO mice, but there was persistent expression of at least one other transcript that does not include the first exon. Wild type (WT, heterozygous (HET, and KO mice were assessed using several well-established behavioral paradigms that model aspects of schizophrenia. Csmd1 KO mice did not differ from wild-type littermates for sensorimotor gating (measured as prepulse inhibition, social interaction, anhedonia (measured by sucrose preference, or sensitivity to the locomotor stimulant effects of the dopaminergic agent d-amphetamine. These data demonstrate that loss of Csmd1 transcripts that include the first exon does not alter multiple well-established behaviors that model aspects of schizophrenia. The SNP most strongly associated with schizophrenia in humans is between exons 3 and 4; therefore, ablation of exon 1 appeared to be a logical animal model. Nevertheless, future studies should consider alternative mouse models including gain-of-function mutations, and loss-of-function mutations that target alternative transcripts of Csmd1.

  18. [Development of a peristaltic inhibition model in mice].

    Science.gov (United States)

    Cui, S; Li, Y; Li, Y; Han, C

    2000-11-01

    Diphenoxylate was administered to mice at the dose of 5 mg/kg BW for the development of peristaltic inhibition model for formulating the examination procedure of health foods. An ink solution containing 5% charcoal was then administered 30 minutes later. The length of ink progradation of the small intestine of mice was calculated 25 minutes after the administration of ink. The results in this model was stable and reliable, and it was recommended to use this model to verify the function of health foods.

  19. Scurfy mice: A model for autoimmune disease

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, V.L.

    1993-01-01

    Autoimmune disease-the condition in which the body attacks its own tissue-has been an object of public concern recently. Former President George Bush and his wife Barbara both are afflicted with Graves' disease in which the body's own immune system attakcs the thyroid gland. The safety of breast implants was called into question because of evidence that some recipients had developed autoimmune disorders such a rheumatoid arthritis, systemic lupus erythematosus, and scleroderma. Women, the media pointed out, have a higher-than-average incidence of many autoimmune disorders. These events suggest the need to know more about what makes the immune system work so well and what makes it go awry. At ORNL's Biology Division, progress is being in understanding the underlying causes of immune disease by studying mice having a disease that causes them to be underdeveloped; to have scaly skin, small ears, and large spleens; to open their eyes late; and to die early. These [open quotes]scurfy[close quotes]mice are helping us better understand the role of the thymus gland in autoimmune disease.

  20. Systemic cytokine response in moribund mice of streptococcal toxic shock syndrome model.

    Science.gov (United States)

    Saito, Mitsumasa; Kajiwara, Hideko; Iida, Ken-ichiro; Hoshina, Takayuki; Kusuhara, Koichi; Hara, Toshiro; Yoshida, Shin-ichi

    2011-02-01

    Streptococcus pyogenes causes severe invasive disease in humans, including streptococcal toxic shock syndrome (STSS). We previously reported a mouse model that is similar to human STSS. When mice were infected intramuscularly with 10(7) CFU of S. pyogenes, all of them survived acute phase of infection. After 20 or more days of infection, a number of them died suddenly accompanied by S. pyogenes bacteremia. We call this phenomenon "delayed death". We analyzed the serum cytokine levels of mice with delayed death, and compared them with those of mice who died in the acute phase of intravenous S. pyogenes infection. The serum levels of TNF-α and IFN-γ in mice of delayed death were more than 100 times higher than those in acute death mice. IL-10 and IL-12, which were not detected in acute death, were also significantly higher in mice of delayed death. IL-6 and MCP-1 (CCL-2) were elevated in both groups of mice. It was noteworthy that not only pro-inflammatory cytokines but also anti-inflammatory cytokines were elevated in delayed death. We also found that intravenous TNF-α injection accelerated delayed death, suggesting that an increase of serum TNF-α induced S. pyogenes bacteremia in our mouse model.

  1. A sensitive venous bleeding model in haemophilia A mice

    DEFF Research Database (Denmark)

    Pastoft, Anne Engedahl; Lykkesfeldt, Jens; Ezban, M.

    2012-01-01

    Haemostatic effect of compounds for treating haemophilia can be evaluated in various bleeding models in haemophilic mice. However, the doses of factor VIII (FVIII) for normalizing bleeding used in some of these models are reported to be relatively high. The aim of this study was to establish...... a sensitive venous bleeding model in FVIII knock out (F8-KO) mice, with the ability to detect effect on bleeding at low plasma FVIII concentrations. We studied the effect of two recombinant FVIII products, N8 and Advate(®), after injury to the saphenous vein. We found that F8-KO mice treated with increasing...... doses of either N8 or Advate(®) showed a dose-dependent increase in the number of clot formations and a reduction in both average and maximum bleeding time, as well as in average blood loss. For both compounds, significant effect was found at doses as low as 5 IU kg(-1) when compared with vehicle...

  2. BALANCED SCORECARDS EVALUATION MODEL THAT INCLUDES ELEMENTS OF ENVIRONMENTAL MANAGEMENT SYSTEM USING AHP MODEL

    Directory of Open Access Journals (Sweden)

    Jelena Jovanović

    2010-03-01

    Full Text Available The research is oriented on improvement of environmental management system (EMS using BSC (Balanced Scorecard model that presents strategic model of measurem ents and improvement of organisational performance. The research will present approach of objectives and environmental management me trics involvement (proposed by literature review in conventional BSC in "Ad Barska plovi dba" organisation. Further we will test creation of ECO-BSC model based on business activities of non-profit organisations in order to improve envir onmental management system in parallel with other systems of management. Using this approach we may obtain 4 models of BSC that includ es elements of environmen tal management system for AD "Barska plovidba". Taking into acc ount that implementation and evaluation need long period of time in AD "Barska plovidba", the final choice will be based on 14598 (Information technology - Software product evaluation and ISO 9126 (Software engineering - Product quality using AHP method. Those standards are usually used for evaluation of quality software product and computer programs that serve in organisation as support and factors for development. So, AHP model will be bas ed on evolution criteria based on suggestion of ISO 9126 standards and types of evaluation from two evaluation teams. Members of team & will be experts in BSC and environmental management system that are not em ployed in AD "Barska Plovidba" organisation. The members of team 2 will be managers of AD "Barska Plovidba" organisation (including manage rs from environmental department. Merging results based on previously cr eated two AHP models, one can obtain the most appropriate BSC that includes elements of environmental management system. The chosen model will present at the same time suggestion for approach choice including ecological metrics in conventional BSC model for firm that has at least one ECO strategic orientation.

  3. Establishment of mice model with human viral hepatitis B

    Science.gov (United States)

    Gao, Li-Fen; Sun, Wen-Sheng; Ma, Chun-Hong; Liu, Su-Xia; Wang, Xiao-Yan; Zhang, Li-Ning; Cao, Ying-Lin; Zhu, Fa-Liang; Liu, Yu-Gang

    2004-01-01

    AIM: To establish a mice model of hepatitis B by using HBV-transgenic mice, and to transfer HBV-specific cytotoxic T lymphocytes (CTL) induced from syngeneic BALB/c mice immunized by a eukaryotic expression vector containing HBV complete genome DNA. METHODS: HBV DNA was obtained from digested pBR322-2HBV and ligated with the vector pcDNA3. Recombinant pcDNA3-HBV was identified by restriction endonuclease assay and transfected into human hepatoma cell line HepG2 with lipofectin. ELISA was used to detect the expression of HBsAg in culture supernatant, and RT-PCR to determine the existence of HBV PreS1 mRNA. BALB/c mice were immunized with pcDNA3-HBV or pcDNA3 by intramuscular injection. ELISA was used to detect the expression of HBsAb in serum. MTT assay was used to measure non-specific or specific proliferation ability and specific killing activity of spleen lymphocytes. Lymphocytes from immunized mice were transferred into HBV-transgenic mice (2.5 × 107 per mouse). Forty-eight hours later, the level of serum protein and transaminase was detected with biochemical method, liver and kidney were sectioned and stained by HE to observe the pathological changes. RESULTS: By enzyme digestion with Eco RI, Xho I and Hind III, the recombinant pcDNA3-HBV was verified to contain a single copy of HBV genome, which was inserted in the positive direction. HepG2 cells transfected with the recombinant could stably express PreS1 mRNA and HBsAg. After immunized by pcDNA3-HBV for 4 weeks, HBsAb was detected in the serum of BALB/c mice. The potential of spleen lymphocytes for both non-specific and specific proliferation and the specific killing activity against target cells were enhanced. The transgenic mice in model group had no significant changes in the level of serum protein but had an obvious increase of ALT and AST. The liver had obvious pathological changes, while the kidney had no evident damage. CONCLUSION: A eukaryotic expression vector pcDNA3-HBV containing HBV complete

  4. Firn Model Intercomparison Experiment (FirnMICE)

    DEFF Research Database (Denmark)

    Lundin, Jessica M.D.; Stevens, C. Max; Arthern, Robert

    2017-01-01

    Evolution of cold dry snow and firn plays important roles in glaciology; however, the physical formulation of a densification law is still an active research topic. We forced eight firn-densification models and one seasonal-snow model in six different experiments by imposing step changes in tempe......Evolution of cold dry snow and firn plays important roles in glaciology; however, the physical formulation of a densification law is still an active research topic. We forced eight firn-densification models and one seasonal-snow model in six different experiments by imposing step changes...... rate and temperature. Firn Model Intercomparison Experiment can provide a benchmark of results for future models, provide a basis to quantify model uncertainties and guide future directions of firn-densification modeling....

  5. Detection of allergenic compounds using an IL-4/luciferase/CNS-1 transgenic mice model.

    Science.gov (United States)

    Bae, Chang Joon; Lee, Jae Won; Bae, Hee Sook; Shim, Sun Bo; Jee, Seung Wan; Lee, Su Hae; Lee, Chang Kyu; Hong, Jin Tae; Hwang, Dae Youn

    2011-04-01

    The interleukin-4 (IL-4) signaling cascade has been identified as a potentially important pathway in the development of allergies. The principal objective of this study was to produce novel transgenic (Tg) mice harboring the luciferase gene under the control of the human IL-4 promoter and the enhancer of IL-4 (CNS-1), in an effort to evaluate three types of allergens including a respiratory sensitizer, vaccine additives, and crude extracts of natural allergens in vivo. A new lineage of Tg mice was generated by the microinjection of pIL-4/Luc/CNS-1 constructs into a fertilized mice egg. The luciferase activity was successfully regulated by the IL-4 promoter in splenocytes cultured from IL-4/Luc/CNS-1 Tg mice. From the first five founder lines, one (#57) evidencing a profound response to ovalbumin was selected for use in evaluating the allergens. Additionally, the lungs, thymus, and lymph nodes of IL-4/Luc/CNS-1 Tg mice evidenced high luciferase activity in response to allergens such as phthalic anhydride (PA), trimellitic anhydride, ovalbumin, gelatin, Dermatophagoides pteronyssinus extracts, and Japanese cedar pollen, whereas key allergy-related indicators including ear thickness, Immunoglobulin E concentration, and the infiltration of inflammatory leukocytes in response to PA were unaltered in the Tg mice relative to the non-Tg mice. Furthermore, the expression levels of endogenous type 2 helper T cells cytokines and proinflammatory cytokines were similarly increased in these organs of IL-4/Luc/CNS-1 Tg mice in response to allergens. These results indicate that IL-4/Luc/CNS-1 Tg mice may be used as an animal model for the evaluation and prediction of the human body response to a variety of allergens originating from the environment and from certain industrial products.

  6. Creatine transporter (CrT; Slc6a8 knockout mice as a model of human CrT deficiency.

    Directory of Open Access Journals (Sweden)

    Matthew R Skelton

    Full Text Available Mutations in the creatine (Cr transporter (CrT; Slc6a8 gene lead to absence of brain Cr and intellectual disabilities, loss of speech, and behavioral abnormalities. To date, no mouse model of CrT deficiency exists in which to understand and develop treatments for this condition. The purpose of this study was to generate a mouse model of human CrT deficiency. We created mice with exons 2-4 of Slc6a8 flanked by loxP sites and crossed these to Cre:CMV mice to create a line of ubiquitous CrT knockout expressing mice. Mice were tested for learning and memory deficits and assayed for Cr and neurotransmitter levels. Male CrT(⁻/y (affected mice lack Cr in the brain and muscle with significant reductions of Cr in other tissues including heart and testes. CrT(⁻/y mice showed increased path length during acquisition and reversal learning in the Morris water maze. During probe trials, CrT(⁻/y mice showed increased average distance from the platform site. CrT(⁻/y mice showed reduced novel object recognition and conditioned fear memory compared to CrT(+/y. CrT(⁻/y mice had increased serotonin and 5-hydroxyindole acetic acid in the hippocampus and prefrontal cortex. Ubiquitous CrT knockout mice have learning and memory deficits resembling human CrT deficiency and this model should be useful in understanding this disorder.

  7. Regulation of an Autoimmune Model for Multiple Sclerosis in Th2-Biased GATA3 Transgenic Mice

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    Viromi Fernando

    2014-01-01

    Full Text Available T helper (Th2 cells have been proposed to play a neuroprotective role in multiple sclerosis (MS. This is mainly based on “loss-of-function” studies in an animal model for MS, experimental autoimmune encephalomyelitis (EAE, using blocking antibodies against Th2 related cytokines, and knockout mice lacking Th2-related molecules. We tested whether an increase of Th2 responses (“gain-of-function” approach could alter EAE, the approach of novel GATA binding protein 3 (GATA3-transgenic (tg mice that overexpress GATA3, a transcription factor required for Th2 differentiation. In EAE induced with myelin oligodendrocyte glycoprotein (MOG35−55 peptide, GATA3-tg mice had a significantly delayed onset of disease and a less severe maximum clinical score, compared with wild-type C57BL/6 mice. Histologically, GATA3-tg mice had decreased levels of meningitis and demyelination in the spinal cord, and anti-inflammatory cytokine profiles immunologically, however both groups developed similar levels of MOG-specific lymphoproliferative responses. During the early stage, we detected higher levels of interleukin (IL-4 and IL-10, with MOG and mitogen stimulation of regional lymph node cells in GATA3-tg mice. During the late stage, only mitogen stimulation induced higher IL-4 and lower interferon-γ and IL-17 production in GATA3-tg mice. These results suggest that a preexisting bias toward a Th2 immune response may reduce the severity of inflammatory demyelinating diseases, including MS.

  8. Firn Model Intercomparison Experiment (FirnMICE)

    DEFF Research Database (Denmark)

    Lundin, Jessica M.D.; Stevens, C. Max; Arthern, Robert

    2017-01-01

    Evolution of cold dry snow and firn plays important roles in glaciology; however, the physical formulation of a densification law is still an active research topic. We forced eight firn-densification models and one seasonal-snow model in six different experiments by imposing step changes in tempe......Evolution of cold dry snow and firn plays important roles in glaciology; however, the physical formulation of a densification law is still an active research topic. We forced eight firn-densification models and one seasonal-snow model in six different experiments by imposing step changes...

  9. Exploring female mice interstrain differences relevant for models of depression

    Directory of Open Access Journals (Sweden)

    Daniela de Sá Calçada

    2015-12-01

    Full Text Available Depression is an extremely heterogeneous disorder. Diverse molecular mechanisms have been suggested to underlie its etiology. To understand the molecular mechanisms responsible for this complex disorder, researchers have been using animal models extensively, namely mice from various genetic backgrounds and harboring distinct genetic modifications. The use of numerous mouse models has contributed to enrich our knowledge on depression. However, accumulating data also revealed that the intrinsic characteristics of each mouse strain might influence the experimental outcomes, which may justify some conflicting evidence reported in the literature. To further understand the impact of the genetic background we performed a multimodal comparative study encompassing the most relevant parameters commonly addressed in depression in three of the most widely used mouse strains: Balb/c, C57BL/6 and CD-1. Moreover, female mice were selected for this study taken into account the higher prevalence of depression in woman and the fewer animal studies using this gender. Our results show that Balb/c mice have a more pronounced anxious-like behavior than CD-1 and C57BL/6 mice, whereas C57BL/6 animals present the strongest depressive-like trait. Furthermore, C57BL/6 mice display the highest rate of proliferating cells and brain-derived neurotrophic factor expression levels in the hippocampus, while hippocampal dentate granular neurons of Balb/c mice show smaller dendritic lengths and fewer ramifications. Of notice, the expression levels of inducible nitric oxide synthase (iNos predict 39,5% of the depressive-like behavior index, which suggests a key role of hippocampal iNOS in depression.Overall, this study reveals important interstrain differences in several behavioral dimensions and molecular and cellular parameters that should be considered when preparing and analyzing experiments addressing depression using mouse models. It further contributes to the literature by

  10. Smart Voyage Planning Model Sensitivity Analysis Using Ocean and Atmospheric Models Including Ensemble Methods

    Science.gov (United States)

    2012-09-01

    ATMOSPHERIC MODELS INCLUDING ENSEMBLE METHODS Scott E. Miller Lieutenant Commander, United States Navy B.S., University of South Carolina, 2000 B.S...Typical gas turbine fuel consumption curve and relationship to sea state .......51  Figure 16.  DDG 58 speed reduction curves for bow seas...Day Time Group ECDIS-N Electronic Chart Display and Information System – Navy ECMWF European Center for Medium Range Weather Forecasts EFAS

  11. 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.``

  12. Over-expression of a human chromosome 22q11.2 segment including TXNRD2, COMT and ARVCF developmentally affects incentive learning and working memory in mice.

    Science.gov (United States)

    Suzuki, Go; Harper, Kathryn M; Hiramoto, Takeshi; Funke, Birgit; Lee, MoonSook; Kang, Gina; Buell, Mahalah; Geyer, Mark A; Kucherlapati, Raju; Morrow, Bernice; Männistö, Pekka T; Agatsuma, Soh; Hiroi, Noboru

    2009-10-15

    Duplication of human chromosome 22q11.2 is associated with elevated rates of mental retardation, autism and many other behavioral phenotypes. However, because duplications cover 1.5-6 Mb, the precise manner in which segments of 22q11.2 causally affect behavior is not known in humans. We have now determined the developmental impact of over-expression of an approximately 190 kb segment of human 22q11.2, which includes the genes TXNRD2, COMT and ARVCF, on behaviors in bacterial artificial chromosome (BAC) transgenic (TG) mice. BAC TG mice and wild-type (WT) mice were tested for their cognitive capacities, affect- and stress-related behaviors and motor activity at 1 and 2 months of age. An enzymatic assay determined the impact of BAC over-expression on the activity level of COMT. BAC TG mice approached a rewarded goal faster (i.e. incentive learning), but were impaired in delayed rewarded alternation during development. In contrast, BAC TG and WT mice were indistinguishable in rewarded alternation without delays, spontaneous alternation, prepulse inhibition, social interaction, anxiety-, stress- and fear-related behaviors and motor activity. Compared with WT mice, BAC TG mice had an approximately 2-fold higher level of COMT activity in the prefrontal cortex, striatum and hippocampus. These data suggest that over-expression of this 22q11.2 segment enhances incentive learning and impairs the prolonged maintenance of working memory, but has no apparent effect on working memory per se, affect- and stress-related behaviors or motor capacity. High copy numbers of this 22q11.2 segment might contribute to a highly selective set of phenotypes in learning and cognition during development.

  13. APP/PS1 transgenic mice treated with aluminum: an update of Alzheimer's disease model.

    Science.gov (United States)

    Zhang, Q L; Jia, L; Jiao, X; Guo, W L; Ji, J W; Yang, H L; Niu, Q

    2012-01-01

    There is still no animal model available that can mimic all the cognitive, behavioral, biochemical, and histopathological abnormalities observed in patients with Alzheimer's disease (AD). We undertook to consider the interaction between genetic factors, including amyloid precursor protein (APP) and presenilin-1 (PS1), and environmental factors, such as Aluminum (Al) in determining susceptibility outcomes when studying the pathogenesis of AD. In this article, we provide an AD model in APP/PS1 transgenic mice triggered by Al. The animal model was established via intracerebral ventricular microinjection of aluminum chloride once a day for 5 days in APP/PS1 transgenic mice. Twenty wild type (WT) mice and 20 APP/PS1 transgenic (TG) mice were separately divided into 2 groups (control and Al group), and a stainless steel injector with stopper was used for microinjection into the left-lateral cerebral ventricle of each mouse. The Morris water maze task was used to evaluate behavioral function of learning and memory ability on the 20th day after the last injection. This AD model's brain was analyzed by: (1) amyloid beta immunohistochemical staining; (2) Tunnel staining; (3) apoptotic rates; (4) caspase-3 gene expression. Here, decrease of cognitive ability and neural cells loss were shown in APP/PS1 transgenic mice exposed to Al, which were more extensive than those in APP/PS1 TG alone and WT mice exposed to Al alone. These findings indicate that there is a close relationship between over-expression of APP and PS1 genes and Al overload. It is also suggested that APP/PS1 TG mice exposed to Al have potential value for improving AD models.

  14. Are NCAM deficient mice an animal model for schizophrenia?

    Directory of Open Access Journals (Sweden)

    Anne eAlbrecht

    2012-07-01

    Full Text Available Genetic and biomarker studies in patients have identified the Neural Cell Adhesion Molecule (NCAM and its associated polysialic acid as a susceptibility factors for schizophrenia. NCAM and polysialtransferase mutant mice have been generated that may serve as animal models for this disorder and allow to investigate underlying neurodevelopmental alterations. Indeed, various schizophrenia-relevant morphological, cognitive and emotional deficits have been observed in these mutants. Here we studied social interaction and attention of NCAM null mutant (NCAM-/- mice as further hallmarks of schizophrenia. Nest building, which is generally associated with social behavior in rodents, was severely impaired, as NCAM-/- mice continuously collected smaller amounts of nest building material than their wild type littermates and built nests of poorer quality. However, social approach tested in a three- compartment- box was not affected and latent inhibition of Pavlovian fear memory was not disturbed in NCAM-/- mice. Although NCAM deficient mice do not display a typical schizophrenia-like phenotype, they may be useful for studying specific endophenotypes with relevance to the disease.

  15. Morphological Alterations in Gastrocnemius and Soleus Muscles in Male and Female Mice in a Fibromyalgia Model.

    Directory of Open Access Journals (Sweden)

    Gabriel Alejandro Bonaterra

    Full Text Available Fibromyalgia (FM is a chronic musculoskeletal pain disorder, characterized by chronic widespread pain and bodily tenderness and is often accompanied by affective disturbances, however often with unknown etiology. According to recent reports, physical and psychological stress trigger FM. To develop new treatments for FM, experimental animal models for FM are needed to be development and characterized. Using a mouse model for FM including intermittent cold stress (ICS, we hypothesized that ICS leads to morphological alterations in skeletal muscles in mice.Male and female ICS mice were kept under alternating temperature (4 °C/room temperature [22 °C]; mice constantly kept at room temperature served as control. After scarification, gastrocnemius and soleus muscles were removed and snap-frozen in liquid nitrogen-cooled isopentane or fixed for electron microscopy.In gastrocnemius/soleus muscles of male ICS mice, we found a 21.6% and 33.2% decrease of fiber cross sectional area (FCSA, which in soleus muscle concerns the loss of type IIa and IIx FCSA. This phenomenon was not seen in muscles of female ICS mice. However, this loss in male ICS mice was associated with an increase in gastrocnemius of the density of MIF+ (8.6%-, MuRF+ (14.7%-, Fbxo32+ (17.8%-cells, a 12.1% loss of capillary contacts/muscle fiber as well as a 30.7% increase of damaged mitochondria in comparison with male control mice. Moreover, significant positive correlations exist among densities (n/mm(2 of MIF+, MuRF+, Fbxo32+-cells in gastrocnemius/ soleus muscles of male ICS mice; these cell densities inversely correlate with FCSA especially in gastrocnemius muscle of male ICS mice.The ICS-induced decrease of FCSA mainly concerns gastrocnemius muscle of male mice due to an increase of inflammatory and atrogenic cells. In soleus muscle of male ICS and soleus/gastrocnemius muscles of female ICS mice morphological alterations seem to occur not at all or delayed. The sex-specificity of

  16. Morphological Alterations in Gastrocnemius and Soleus Muscles in Male and Female Mice in a Fibromyalgia Model

    Science.gov (United States)

    Oezel, Lisa; Schwarzbach, Hans; Ocker, Matthias; Thieme, Kati; Di Fazio, Pietro; Kinscherf, Ralf

    2016-01-01

    Background Fibromyalgia (FM) is a chronic musculoskeletal pain disorder, characterized by chronic widespread pain and bodily tenderness and is often accompanied by affective disturbances, however often with unknown etiology. According to recent reports, physical and psychological stress trigger FM. To develop new treatments for FM, experimental animal models for FM are needed to be development and characterized. Using a mouse model for FM including intermittent cold stress (ICS), we hypothesized that ICS leads to morphological alterations in skeletal muscles in mice. Methods Male and female ICS mice were kept under alternating temperature (4°C/room temperature [22°C]); mice constantly kept at room temperature served as control. After scarification, gastrocnemius and soleus muscles were removed and snap-frozen in liquid nitrogen–cooled isopentane or fixed for electron microscopy. Results In gastrocnemius/soleus muscles of male ICS mice, we found a 21.6% and 33.2% decrease of fiber cross sectional area (FCSA), which in soleus muscle concerns the loss of type IIa and IIx FCSA. This phenomenon was not seen in muscles of female ICS mice. However, this loss in male ICS mice was associated with an increase in gastrocnemius of the density of MIF+ (8.6%)-, MuRF+ (14.7%)-, Fbxo32+ (17.8%)-cells, a 12.1% loss of capillary contacts/muscle fiber as well as a 30.7% increase of damaged mitochondria in comparison with male control mice. Moreover, significant positive correlations exist among densities (n/mm2) of MIF+, MuRF+, Fbxo32+-cells in gastrocnemius/ soleus muscles of male ICS mice; these cell densities inversely correlate with FCSA especially in gastrocnemius muscle of male ICS mice. Conclusion The ICS-induced decrease of FCSA mainly concerns gastrocnemius muscle of male mice due to an increase of inflammatory and atrogenic cells. In soleus muscle of male ICS and soleus/gastrocnemius muscles of female ICS mice morphological alterations seem to occur not at all or

  17. Study of Candida Albicans Vaginitis Model in Kunming Mice

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhuo; KONG Xiaofeng

    2007-01-01

    The model of vaginal candidiasis in Kunming mice was constructed in order to search for the optima construction conditions and provide an economic animal model of Candida albicans (C.albicans) vaginitis. Estrogen benzoate (E2) was given to mice at different concentrations ranging from 0.0 to 0.05 mg/mouse (4 levels) beginning 72 h prior to vaginal inoculation, then mice were inoculated intravaginally with various concentrations of stationary-phase C. albicans blastoconidia (ATCC90028) (5 levels) in 20 μL of phosphate-buffered saline (PBS) in each F2 level. General state,scores of genital pathology, the hyphae and vaginal fungal burden (CFU) in vaginal lavage fluid, the hydrops rate of uterus and vaginal tissues for pathological section in mice were observed and obtained at day 2, 4, 7, 14 and 21 after inoculation. The results showed the infection rate in mice was related to the dosage of E2 and concentration of C. albicans blastoconidia. Additionally there was better cross-effect between the two treated factors. The infection rate was about 80% on the day 4,and could reach 100% on the day 7 until the end of experiment after inoculated intravaginally in groups of E2I3, E2 0.025 mg/mouse injected hypodermically and inoculated intravaginally with 5×104 C. albicans blastoconidia, and large amount of hyphae and blastoconidia could be observe in superficial layer tissue and canal of vaginal by PAS. From the results in our experiment it was concluded that E2I3 was the optima construction condition in kunming mice.

  18. Mice with chimeric livers are an improved model for human lipoprotein metabolism.

    Directory of Open Access Journals (Sweden)

    Ewa C S Ellis

    Full Text Available OBJECTIVE: Rodents are poor model for human hyperlipidemias because total cholesterol and low density lipoprotein levels are very low on a normal diet. Lipoprotein metabolism is primarily regulated by hepatocytes and we therefore assessed whether chimeric mice extensively repopulated with human cells can model human lipid and bile acid metabolism. DESIGN: FRG [ F ah(-/- R ag2(-/-Il2r g (-/-] mice were repopulated with primary human hepatocytes. Serum lipoprotein lipid composition and distribution (VLDL, LDL, and HDL was analyzed by size exclusion chromatography. Bile was analyzed by LC-MS or by GC-MS. RNA expression levels were measured by quantitative RT-PCR. RESULTS: Chimeric mice displayed increased LDL and VLDL fractions and a lower HDL fraction compared to wild type, thus significantly shifting the ratio of LDL/HDL towards a human profile. Bile acid analysis revealed a human-like pattern with high amounts of cholic acid and deoxycholic acid (DCA. Control mice had only taurine-conjugated bile acids as expcted, but highly repopulated mice had glycine-conjugated cholic acid as found in human bile. RNA levels of human genes involved in bile acid synthesis including CYP7A1, and CYP27A1 were significantly upregulated as compared to human control liver. However, administration of recombinant hFGF19 restored human CYP7A1 levels to normal. CONCLUSION: Humanized-liver mice showed a typical human lipoprotein profile with LDL as the predominant lipoprotein fraction even on a normal diet. The bile acid profile confirmed presence of an intact enterohepatic circulation. Although bile acid synthesis was deregulated in this model, this could be fully normalized by FGF19 administration. Taken together these data indicate that chimeric FRG-mice are a useful new model for human lipoprotein and bile-acid metabolism.

  19. Improved Subseasonal Prediction with Advanced Coupled Models including the 30km FIM-HYCOM Coupled Model

    Science.gov (United States)

    Benjamin, Stan; Sun, Shan; Grell, Georg; Green, Benjamin; Bleck, Rainer; Li, Haiqin

    2017-04-01

    Extreme events for subseasonal duration have been linked to multi-week processes related to onset, duration, and cessation of blocking events or, more generally, quasi-stationary waves. Results will be shown from different sets of 32-day prediction experiments (3200 runs each) over a 16-year period for earth system processes key for subseasonal prediction for different resolution, numerics, and physics using the FIM-HYCOM coupled model. The coupled atmosphere (FIM) and ocean (HYCOM) modeling system is a relatively new coupled atmosphere-ocean model developed for subseasonal to seasonal prediction (Green et al. 2017 Mon.Wea.Rev. accepted, Bleck et al 2015 Mon. Wea. Rev.). Both component models operate on a common icosahedral horizontal grid and use an adaptive hybrid vertical coordinate (sigma-isentropic in FIM and sigma-isopycnic in HYCOM). FIM-HYCOM has been used to conduct 16 years of subseasonal retrospective forecasts following the NOAA Subseasonal (SubX) NMME protocol (32-day forward integrations), run with 4 ensemble members per week. Results from this multi-year FIM-HYCOM hindcast include successful forecasts out to 14-20 days for stratospheric warming events (from archived 10 hPa fields), improved MJO predictability (Green et al. 2017) using the Grell-Freitas (2014, ACP) scale-aware cumulus scheme instead of the Simplified Arakawa-Schubert scheme, and little sensitivity to resolution for blocking frequency. Forecast skill of metrics from FIM-HYCOM including 500 hPa heights and MJO index is at least comparable to that of the operational Climate Forecast System (CFSv2) used by the National Centers for Environmental Prediction. Subseasonal skill is improved with a limited multi-model (FIM-HYCOM and CFSv2), consistent with previous seasonal multi-model ensemble results. Ongoing work will also be reported on for adding inline aerosol/chemistry treatment to the coupled FIM-HYCOM model and for advanced approaches to subgrid-scale clouds to address regional biases

  20. Are NCAM deficient mice an animal model for schizophrenia?

    OpenAIRE

    Anne eAlbrecht; Oliver eStork

    2012-01-01

    Genetic and biomarker studies in patients have identified the Neural Cell Adhesion Molecule (NCAM) and its associated polysialic acid (PSA) as a susceptibility factors for schizophrenia. NCAM and polysialtransferase mutant mice have been generated that may serve as animal models for this disorder and allow to investigate underlying neurodevelopmental alterations. Indeed, various schizophrenia-relevant morphological, cognitive and emotional deficits have been observed in these mutants. Here we...

  1. Neurochemical and Behavioral Characteristics of Toxic Milk Mice: An Animal Model of Wilson’s Disease

    OpenAIRE

    2013-01-01

    Toxic milk mice have an inherited defect of copper metabolism. Hepatic phenotype of the toxic milk mice is similar to clinical findings in humans suffering from Wilson’s disease (WND). In the present study, neurotransmitter system and locomotor performance in toxic milk mice was examined to verify the feasibility of this animal model for studying neuropathology of WND. Mice aged 2 and 12 months were used in the experiment. The mice were tested according to rotarod and footprint protocols. Mon...

  2. Zika Virus Infection in Dexamethasone-immunosuppressed Mice Demonstrating Disseminated Infection with Multi-organ Involvement Including Orchitis Effectively Treated by Recombinant Type I Interferons.

    Science.gov (United States)

    Chan, Jasper Fuk-Woo; Zhang, Anna Jinxia; Chan, Chris Chung-Sing; Yip, Cyril Chik-Yan; Mak, Winger Wing-Nga; Zhu, Houshun; Poon, Vincent Kwok-Man; Tee, Kah-Meng; Zhu, Zheng; Cai, Jian-Piao; Tsang, Jessica Oi-Ling; Chik, Kenn Ka-Heng; Yin, Feifei; Chan, Kwok-Hung; Kok, Kin-Hang; Jin, Dong-Yan; Au-Yeung, Rex Kwok-Him; Yuen, Kwok-Yung

    2016-12-01

    Disseminated or fatal Zika virus (ZIKV) infections were reported in immunosuppressed patients. Existing interferon-signaling/receptor-deficient mouse models may not be suitable for evaluating treatment effects of recombinant interferons. We developed a novel mouse model for ZIKV infection by immunosuppressing BALB/c mice with dexamethasone. Dexamethasone-immunosuppressed male mice (6-8weeks) developed disseminated infection as evidenced by the detection of ZIKV-NS1 protein expression and high viral loads in multiple organs. They had ≥10% weight loss and high clinical scores soon after dexamethasone withdrawal (10dpi), which warranted euthanasia at 12dpi. Viral loads in blood and most tissues at 5dpi were significantly higher than those at 12dpi (P<0.05). Histological examination revealed prominent inflammatory infiltrates in multiple organs, and CD45+ and CD8+ inflammatory cells were seen in the testis. These findings suggested that clinical deterioration occurred during viral clearance by host immune response. Type I interferon treatments improved clinical outcome of mice (100% vs 0% survival). Besides virus dissemination, inflammation of various tissues, especially orchitis, may be potential complications of ZIKV infection with significant implications on disease transmission and male fertility. Interferon treatment should be considered in patients at high risks for ZIKV-associated complications when the potential benefits outweigh the side effects of treatment. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  3. BALB/c mice model of cytomegalovirus-induced myocarditis

    Institute of Scientific and Technical Information of China (English)

    Yi Xu; Feng Fang; Zhidan Xiang; Hong zeng; Ge Li

    2005-01-01

    Objective: A BALB/c mice model of cytomegalovirus-induced myocarditis was established. Methods: Twentyfive inbred female BALB/c mice free of murine cytomegalovirus(MCMV) infection (5 weeks old, 16-18 g), were infected with 1 x 104PFU MCMV by the intraperitoneal (i. p. ) administration. All experimental mice were sacrificed on day 3, 5, 7, 10, and 14 after i. p. administration. The hearts were removed under aseptic conditions, and were transected along the midline. Aliquots of hearts were handled with Bouin' s fixative for histological examination. Residual hearts were immediately frozen in liquid nitrogen and stored at - 80℃ until MCMV titre was determined by a plaque assay. Seurm cTnI level was assayed by ELISA. Results: MCMV in the heart was at extremely low level on day 3 after i. p. administration, reached to the peak on day 7-10, and then ran down. A mixed cellular infiltrate composed of polymorphonuclear neutrophils and mononuclear lymphocytes was observed on day 3, reaching to the peak on day 7-10 after MCMV infection, and was maintained for at least 3-4 months later. Seurm cTnI levels were elevated on day 3 after i.p. administration, reaching to the peak it day7-10. Conclusion: The BALB/c mice model for cytomegalovirus-induced myocarditis was successfully established, that might make it possible to screen antiviral drugs for treating viral myocarditis and to investigate and evaluate the pathogenesis and prognosis of this disease.

  4. Development of a model for marburgvirus based on severe-combined immunodeficiency mice

    Directory of Open Access Journals (Sweden)

    Kalina Warren V

    2007-10-01

    Full Text Available Abstract The filoviruses, Ebola (EBOV and Marburg (MARV, cause a lethal hemorrhagic fever. Human isolates of MARV are not lethal to immmunocompetent adult mice and, to date, there are no reports of a mouse-adapted MARV model. Previously, a uniformly lethal EBOV-Zaire mouse-adapted virus was developed by performing 9 sequential passages in progressively older mice (suckling to adult. Evaluation of this model identified many similarities between infection in mice and nonhuman primates, including viral tropism for antigen-presenting cells, high viral titers in the spleen and liver, and an equivalent mean time to death. Existence of the EBOV mouse model has increased our understanding of host responses to filovirus infections and likely has accelerated the development of countermeasures, as it is one of the only hemorrhagic fever viruses that has multiple candidate vaccines and therapeutics. Here, we demonstrate that serially passaging liver homogenates from MARV-infected severe combined immunodeficient (scid mice was highly successful in reducing the time to death in scid mice from 50–70 days to 7–10 days after MARV-Ci67, -Musoke, or -Ravn challenge. We performed serial sampling studies to characterize the pathology of these scid mouse-adapted MARV strains. These scid mouse-adapted MARV models appear to have many similar properties as the MARV models previously developed in guinea pigs and nonhuman primates. Also, as shown here, the scid-adapted MARV mouse models can be used to evaluate the efficacy of candidate antiviral therapeutic molecules, such as phosphorodiamidate morpholino oligomers or antibodies.

  5. FUS/TLS acts as an aggregation-dependent modifier of polyglutamine disease model mice

    Science.gov (United States)

    Kino, Yoshihiro; Washizu, Chika; Kurosawa, Masaru; Yamada, Mizuki; Doi, Hiroshi; Takumi, Toru; Adachi, Hiroaki; Katsuno, Masahisa; Sobue, Gen; Hicks, Geoffrey G.; Hattori, Nobutaka; Shimogori, Tomomi; Nukina, Nobuyuki

    2016-01-01

    FUS/TLS is an RNA/DNA-binding protein associated with neurodegenerative diseases including amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Previously, we found that a prion-like domain in the N-terminus of FUS/TLS mediates co-aggregation between FUS/TLS and mutant huntingtin, the gene product of Huntington’s disease (HD). Here, we show that heterozygous knockout of FUS/TLS worsened the phenotypes of model mice of (HD, but not spinal and bulbar muscular atrophy (SBMA). This difference was correlated with the degree of pathological association between disease proteins and FUS/TLS. Co-aggregation between FUS/TLS and mutant huntingtin resulted in the depletion of free FUS/TLS protein in HD mice that was detected as a monomer in SDS-PAGE analysis. Recently, we found that FUS/TLS paralogs, TAF15 and EWS, were up-regulated in homozygous FUS/TLS knockout mice. These two proteins were up-regulated in both HD and FUS/TLS heterozygote mice, and were further elevated in HD-TLS+/− double mutant mice, consistent with the functional impairment of FUS/TLS. These results suggest that FUS/TLS sequestration by co-aggregation is a rate-limiting factor of disease phenotypes of HD and that inclusions may have an adverse aspect, rather than being simply benign or protective. In addition, our results highlight inclusions as repositories of potential modifiers of neurodegeneration. PMID:27739513

  6. Fuzheng Kangbai Granule (扶正抗白冲剂) on Immune Function and Survival Time in Minimal Residual Leukemia Model Mice

    Institute of Scientific and Technical Information of China (English)

    许勇钢; 麻柔; 胡乃平; 刘锋; 杨经敏; 马玲; 胡晓梅

    2001-01-01

    To observe the effects of Fuzheng Kangbai Granule (FZKBG) on immune function and survival time in minimal residual leukemia (MRL) model mice and explore its mechanism. Methods: MRL model mice were established by hypodermic inoculation with L7212 cells 1×106 following intraperitoneal injection of cytoxan (CTX) 250 mg/kg 3 days later, and divided into the control group and FZKBG treated group. The changes of T-lymphocyte subsets, including CD3+, CD4+ and CD8+, and the survival time in model mice were observed. Results: Compared with the control, FZKBG could obviously increase both the percentage and absolute value of CD3+ and CD4+ lymphocytes and prolong the survival time of model mice, the prolongation rate being 29.6% - 60.4%. Conclusion: FZKBG could markedly prolong the survival time of MRL mice, and its mechanism might be through elevating the immunologic function and inhibiting the leukemia cells in model mice.

  7. Induction of animal model of Graves' disease in BALB/c mice

    Institute of Scientific and Technical Information of China (English)

    Zhu-fang Tian; Bing-yin Shi; Xiao-yan Wu; Li Xu

    2009-01-01

    Objective To construct an animal model of Graves' disease (GD) by immunizing BALB/c mice with hM12 cells co-expressing major histocompatibility complex (MHC) class Ⅱ molecules and human thyrotropin receptor (TSHR) molecules. Methods BALB/c mice in experimental group (H-2d) were immunized with hM12 cells Intraper-itoncally every 2 weeks for six times, while mice in control group were immunized with M12 cells. Five weeks later, the thyroids were histologically examined, and serum samples were tested for thyroid-stimulating antibodies (TSAb) and thyroid hormone levels. Results One BALB/c mouse in experimental group developed Graves'-like disease. Total T4 and T3 levels in this mouse were above the upper limit of normal, TSAb activity was displayed in its serum. The thyroid histologically showed the features of thyroid hyperactivity including thyrocyte hypercellularity and colloid absorption.None of control mice developed Graves'-like disease. Conclusion An animal model with some characteristics of human Graves' disease was successfully induced and the model will facilitate studies aimed directly at understanding the patho-genesis of autoimmunity in Graves' disease.

  8. A novel model of human skin pressure ulcers in mice.

    Directory of Open Access Journals (Sweden)

    Andrés A Maldonado

    Full Text Available INTRODUCTION: Pressure ulcers are a prevalent health problem in today's society. The shortage of suitable animal models limits our understanding and our ability to develop new therapies. This study aims to report on the development of a novel and reproducible human skin pressure ulcer model in mice. MATERIAL AND METHODS: Male non-obese, diabetic, severe combined immunodeficiency mice (n = 22 were engrafted with human skin. A full-thickness skin graft was placed onto 4×3 cm wounds created on the dorsal skin of the mice. Two groups with permanent grafts were studied after 60 days. The control group (n = 6 was focused on the process of engraftment. Evaluations were conducted with photographic assessment, histological analysis and fluorescence in situ hybridization (FISH techniques. The pressure ulcer group (n = 12 was created using a compression device. A pressure of 150 mmHg for 8 h, with a total of three cycles of compression-release was exerted. Evaluations were conducted with photographic assessment and histological analysis. RESULTS: Skin grafts in the control group took successfully, as shown by visual assessment, FISH techniques and histological analysis. Pressure ulcers in the second group showed full-thickness skin loss with damage and necrosis of all the epidermal and dermal layers (ulcer stage III in all cases. Complete repair occurred after 40 days. CONCLUSIONS: An inexpensive, reproducible human skin pressure ulcer model has been developed. This novel model will facilitate the development of new clinically relevant therapeutic strategies that can be tested directly on human skin.

  9. ATEFlap aerodynamic model, a dynamic stall model including the effects of trailing edge flap deflection

    Energy Technology Data Exchange (ETDEWEB)

    Bergami, L.; Gaunaa, M.

    2012-02-15

    The report presents the ATEFlap aerodynamic model, which computes the unsteady lift, drag and moment on a 2D airfoil section equipped with Adaptive Trailing Edge Flap. The model captures the unsteady response related to the effects of the vorticity shed into the wake, and the dynamics of flow separation a thin-airfoil potential flow model is merged with a dynamic stall model of the Beddoes-Leishmann type. The inputs required by the model are steady data for lift, drag, and moment coefficients as function of angle of attack and flap deflection. Further steady data used by the Beddoes- Leishmann dynamic stall model are computed in an external preprocessor application, which gives the user the possibility to verify, and eventually correct, the steady data passed to the aerodynamic model. The ATEFlap aerodynamic model is integrated in the aeroelastic simulation tool HAWC2, thus al- lowing to simulate the response of a wind turbine with trailing edge flaps on the rotor. The algorithms used by the preprocessor, and by aerodynamic model are presented, and modifications to previous implementations of the aerodynamic model are briefly discussed. The performance and the validity of the model are verified by comparing the dynamic response computed by the ATEFlap with solutions from CFD simulations. (Author)

  10. Phenylethanoid Glycosides of Cistanche on menopausal syndrome model in mice

    Directory of Open Access Journals (Sweden)

    Shuo Tian

    2017-05-01

    Full Text Available Cistanche is the traditional and precious Chinese herbal, with two thousand years of use history in China. It has the effect on tonifying kidney, strong supplement to the liver and kidney, and replenishing essence and blood, known as the “desert ginseng”. Here, we explored the mechanism of Phenylethanoid Glycosides of Cistanche (PGC to the model mice of menopausal syndrome, as well as the therapeutic effect and characteristics of PGC to the menopausal syndrome. In this study, KM mice were reproduced by the complete resection of the ovaries on both sides of the back to establish the model mice of menopausal syndrome (MPS, and received distilled water or drugs, respectively. Model mice received distilled water. Mice received 200 mg/(kg day high doses of Phenylethanoid Glycosides of Cistanche (HPGC, and 100 mg/(kg day medium doses of Phenylethanoid Glycosides of Cistanche (MPGC, and 50 mg/(kg day low doses of Phenylethanoid Glycosides of Cistanche (LPGC. After 21 days, it could determine the number of independent activities and the number of standing, the latent period of first entering the dark room, and the electric number. It also calculated the viscera index of uterus, thymus, spleen, measured the levels of estradiol (E2, testosterone (T, luteinizing hormone (LH, and follicle-stimulating hormone (FSH in the serum. Furthermore, it observed the pathological changes of uterus, thymus, spleen and pituitary of mice. The results showed that behavioral indicators: Compared with the model group (MG, HPGC, MPGC, LPGC could increase the independent activities (P < 0.01; HPGC, MPGC could increase the number of standing, the latent period of first entering the dark room, and reduce the electric number (P < 0.01; LPGC could increase the number of standing (P < 0.05; Viscera index: Compared with MG, HPGC, MPGC could increase the viscera index of uterus, thymus, spleen (P < 0.01; LPGC could increase the viscera index of uterus (P < 0

  11. Importance of global aerosol modeling including secondary organic aerosol formed from monoterpene

    OpenAIRE

    Goto, Daisuke; Takemura, Toshihiko; Nakajima, Teruyuki

    2008-01-01

    A global three-dimensional aerosol transport-radiation model, coupled to an atmospheric general circulation model (AGCM), has been extended to improve the model process for organic aerosols, particularly secondary organic aerosols (SOA), and to estimate SOA contributions to direct and indirect radiative effects. Because the SOA formation process is complicated and unknown, the results in different model simulations include large differences. In this work, we simulate SOA production assuming v...

  12. MODEL ANALYSIS AND PARAMETER EXTRACTION FOR MOS CAPACITOR INCLUDING QUANTUM MECHANICAL EFFECTS

    Institute of Scientific and Technical Information of China (English)

    Hai-yan Jiang; Ping-wen Zhang

    2006-01-01

    The high frequency CV curves of MOS capacitor have been studied. It is shown that semiclassical model is a good approximation to quantum model and approaches to classical model when the oxide layer is thick. This conclusion provides us an efficient (semiclassical) model including quantum mechanical effects to do parameter extraction for ultrathi noxide device. Here the effective extracting strategy is designed and numerical experiments demonstrate the validity of the strategy.

  13. A finite element model of the face including an orthotropic skin model under in vivo tension.

    Science.gov (United States)

    Flynn, Cormac; Stavness, Ian; Lloyd, John; Fels, Sidney

    2015-01-01

    Computer models of the human face have the potential to be used as powerful tools in surgery simulation and animation development applications. While existing models accurately represent various anatomical features of the face, the representation of the skin and soft tissues is very simplified. A computer model of the face is proposed in which the skin is represented by an orthotropic hyperelastic constitutive model. The in vivo tension inherent in skin is also represented in the model. The model was tested by simulating several facial expressions by activating appropriate orofacial and jaw muscles. Previous experiments calculated the change in orientation of the long axis of elliptical wounds on patients' faces for wide opening of the mouth and an open-mouth smile (both 30(o)). These results were compared with the average change of maximum principal stress direction in the skin calculated in the face model for wide opening of the mouth (18(o)) and an open-mouth smile (25(o)). The displacements of landmarks on the face for four facial expressions were compared with experimental measurements in the literature. The corner of the mouth in the model experienced the largest displacement for each facial expression (∼11-14 mm). The simulated landmark displacements were within a standard deviation of the measured displacements. Increasing the skin stiffness and skin tension generally resulted in a reduction in landmark displacements upon facial expression.

  14. Modeling Human Graft-Versus-Host Disease in Immunocompromised Mice.

    Science.gov (United States)

    Norelli, Margherita; Camisa, Barbara; Bondanza, Attilio

    2016-01-01

    Hematopoietic stem cell transplantation (HSCT) from an allogeneic donor is an effective form of cancer immunotherapy, especially for acute leukemias. HSCT is however frequently complicated by the occurrence of graft-versus-host disease (GVHD). Immunocompromised mice infused with human T cells often develop a clinical syndrome resembling human GVHD (xenogeneic or X-GVHD). Herein, we describe a method for inducing X-GVHD in a highly reproducible manner. Given the human nature of immune effectors, this xenogeneic model can be routinely adopted for screening the efficacy of new treatments for GVHD.

  15. Initiation-promotion model of tumor prevalence in mice from space radiation exposures.

    Science.gov (United States)

    Cucinotta, F A; Wilson, J W

    1995-08-01

    Exposures in space consist of low-level background components from galactic cosmic rays (GCR), occasional intense-energetic solar-particle events, periodic passes through geomagnetic-trapped radiation, and exposure from possible onboard nuclear-propulsion engines. Risk models for astronaut exposure from such diverse components and modalities must be developed to assure adequate protection in future NASA missions. The low-level background exposures (GCR), including relativistic heavy ions (HZE), will be the ultimate limiting factor for astronaut career exposure. We consider herein a two-mutation, initiation-promotion, radiation-carcinogenesis model in mice in which the initiation stage is represented by a linear kinetics model of cellular repair/misrepair, including the track-structure model for heavy ion action cross-sections. The model is validated by comparison with the harderian gland tumor experiments of Alpen et al. for various ion beams. We apply the initiation-promotion model to exposures from galactic cosmic rays, using models of the cosmic-ray environment and heavy ion transport, and consider the effects of the age of the mice prior to and after the exposure and of the length of time in space on predictions of relative risk. Our results indicate that biophysical models of age-dependent radiation hazard will provide a better understanding of GCR risk than models that rely strictly on estimates of the initial slopes of these radiations.

  16. Full-thickness splinted skin wound healing models in db/db and heterozygous mice: implications for wound healing impairment.

    Science.gov (United States)

    Park, Shin Ae; Teixeira, Leandro B C; Raghunathan, Vijay Krishna; Covert, Jill; Dubielzig, Richard R; Isseroff, Roslyn Rivkah; Schurr, Michael; Abbott, Nicholas L; McAnulty, Jonathan; Murphy, Christopher J

    2014-01-01

    The excisional dorsal full-thickness skin wound model with or without splinting is widely utilized in wound healing studies using diabetic or normal mice. However, the effects of splinting on dermal wound healing have not been fully characterized, and there are limited data on the direct comparison of wound parameters in the splinted model between diabetic and normal mice. We compared full-thickness excisional dermal wound healing in db/db and heterozygous mice by investigating the effects of splinting, semi-occlusive dressing, and poly(ethylene glycol) treatment. Two 8-mm full-thickness wounds were made with or without splinting in db/db and heterozygous mice. Body weights, splint maintenance, wound contraction, wound closure, and histopathological parameters including reepithelialization, wound bed collagen deposition, and inflammation were compared between groups. Our results show that silicone splint application effectively reduced wound contraction in heterozygous and db/db mice. Splinted wounds, as opposed to nonsplinted wounds, exhibited no significant differences in wound closure between heterozygous and db/db mice. Finally, polyethylene glycol and the noncontact dressing had no significant effect on wound healing in heterozygous or db/db mice. We believe these findings will help investigators in selection of the appropriate wound model and data interpretation with fully defined parameters.

  17. Sensitization to and Challenge with Gliadin Induce Pancreatitis and Extrapancreatic Inflammation in HLA-DQ8 Mice: An Animal Model of Type 1 Autoimmune Pancreatitis

    Science.gov (United States)

    Moon, Sung-Hoon; Kim, Jihun; Kim, Mi-Young; Park, Do Hyun; Song, Tae Jun; Kim, Sun A; Lee, Sang Soo; Seo, Dong Wan; Lee, Sung Koo; Kim, Myung-Hwan

    2016-01-01

    Background/Aims The aim of this study was to establish a pathogenetic mechanism of pancreatitis in celiac disease and IgG4-related disease using gluten-sensitive human leukocyte antigen (HLA)-DQ8 transgenic mice. Methods Transgenic mice expressing HLA-DQ8 genes were utilized. Control mice were not sensitized but were fed gliadin-free rice cereal. Experimental groups consisted of gliadin-sensitized and gliadin-challenged mice; nonsensitized mice with cerulein hyperstimulation; and gliadin-sensitized and gliadin-challenged mice with cerulein hyperstimulation. Results Gliadin-sensitized and gliadin-challenged mice with cerulein hyperstimulation showed significant inflammatory cell infiltrates, fibrosis and acinar atrophy compared with the control mice and the other experimental groups. The immunohistochemical analysis showed greater IgG1-positive plasma cells in the inflammatory infiltrates of gliadin-sensitized and gliadin-challenged mice with cerulein hyperstimulation compared with the control mice and the other experimental groups. Gliadin-sensitized and gliadin-challenged mice with cerulein hyperstimulation or gliadin-sensitized and gliadin-challenged mice showed IgG1-stained inflammatory cell infiltrates in the extrapancreatic organs, including the bile ducts, salivary glands, kidneys, and lungs. Conclusions Gliadin-sensitization and cerulein hyperstimulation of gluten-sensitive HLA-DQ8 transgenic mice resulted in pancreatitis and extrapancreatic inflammation. This animal model suggests that chronic gliadin ingestion in a susceptible individual with the HLA-DQ8 molecule may be associated with pancreatitis and extrapancreatic inflammation. PMID:27114422

  18. Hot DA white dwarf model atmosphere calculations: Including improved Ni PI cross sections

    CERN Document Server

    Preval, S P; Badnell, N R; Hubeny, I; Holberg, J B

    2016-01-01

    To calculate realistic models of objects with Ni in their atmospheres, accurate atomic data for the relevant ionization stages needs to be included in model atmosphere calculations. In the context of white dwarf stars, we investigate the effect of changing the Ni {\\sc iv}-{\\sc vi} bound-bound and bound-free atomic data has on model atmosphere calculations. Models including PICS calculated with {\\sc autostructure} show significant flux attenuation of up to $\\sim 80$\\% shortward of 180\\AA\\, in the EUV region compared to a model using hydrogenic PICS. Comparatively, models including a larger set of Ni transitions left the EUV, UV, and optical continua unaffected. We use models calculated with permutations of this atomic data to test for potential changes to measured metal abundances of the hot DA white dwarf G191-B2B. Models including {\\sc autostructure} PICS were found to change the abundances of N and O by as much as $\\sim 22$\\% compared to models using hydrogenic PICS, but heavier species were relatively unaf...

  19. Mathematical Model of Thyristor Inverter Including a Series-parallel Resonant Circuit

    Directory of Open Access Journals (Sweden)

    Miroslaw Luft

    2008-01-01

    Full Text Available The article presents a mathematical model of thyristor inverter including a series-parallel resonant circuit with theaid of state variable method. Maple procedures are used to compute current and voltage waveforms in the inverter.

  20. A Verilog-A large signal model for InP DHBT including thermal effects

    Science.gov (United States)

    Yuxia, Shi; Zhi, Jin; Zhijian, Pan; Yongbo, Su; Yuxiong, Cao; Yan, Wang

    2013-06-01

    A large signal model for InP/InGaAs double heterojunction bipolar transistors including thermal effects has been reported, which demonstrated good agreements of simulations with measurements. On the basis of the previous model in which the double heterojunction effect, current blocking effect and high current effect in current expression are considered, the effect of bandgap narrowing with temperature has been considered in transport current while a formula for model parameters as a function of temperature has been developed. This model is implemented by Verilog-A and embedded in ADS. The proposed model is verified with DC and large signal measurements.

  1. Modelling Mediterranean agro-ecosystems by including agricultural trees in the LPJmL model

    Science.gov (United States)

    Fader, M.; von Bloh, W.; Shi, S.; Bondeau, A.; Cramer, W.

    2015-11-01

    In the Mediterranean region, climate and land use change are expected to impact on natural and agricultural ecosystems by warming, reduced rainfall, direct degradation of ecosystems and biodiversity loss. Human population growth and socioeconomic changes, notably on the eastern and southern shores, will require increases in food production and put additional pressure on agro-ecosystems and water resources. Coping with these challenges requires informed decisions that, in turn, require assessments by means of a comprehensive agro-ecosystem and hydrological model. This study presents the inclusion of 10 Mediterranean agricultural plants, mainly perennial crops, in an agro-ecosystem model (Lund-Potsdam-Jena managed Land - LPJmL): nut trees, date palms, citrus trees, orchards, olive trees, grapes, cotton, potatoes, vegetables and fodder grasses. The model was successfully tested in three model outputs: agricultural yields, irrigation requirements and soil carbon density. With the development presented in this study, LPJmL is now able to simulate in good detail and mechanistically the functioning of Mediterranean agriculture with a comprehensive representation of ecophysiological processes for all vegetation types (natural and agricultural) and in a consistent framework that produces estimates of carbon, agricultural and hydrological variables for the entire Mediterranean basin. This development paves the way for further model extensions aiming at the representation of alternative agro-ecosystems (e.g. agroforestry), and opens the door for a large number of applications in the Mediterranean region, for example assessments of the consequences of land use transitions, the influence of management practices and climate change impacts.

  2. Modelling Mediterranean agro-ecosystems by including agricultural trees in the LPJmL model

    Directory of Open Access Journals (Sweden)

    M. Fader

    2015-06-01

    Full Text Available Climate and land use change in the Mediterranean region is expected to affect natural and agricultural ecosystems by decreases in precipitation, increases in temperature as well as biodiversity loss and anthropogenic degradation of natural resources. Demographic growth in the Eastern and Southern shores will require increases in food production and put additional pressure on agro-ecosystems and water resources. Coping with these challenges requires informed decisions that, in turn, require assessments by means of a comprehensive agro-ecosystem and hydrological model. This study presents the inclusion of 10 Mediterranean agricultural plants, mainly perennial crops, in an agro-ecosystem model (LPJmL: nut trees, date palms, citrus trees, orchards, olive trees, grapes, cotton, potatoes, vegetables and fodder grasses. The model was successfully tested in three model outputs: agricultural yields, irrigation requirements and soil carbon density. With the development presented in this study, LPJmL is now able to simulate in good detail and mechanistically the functioning of Mediterranean agriculture with a comprehensive representation of ecophysiological processes for all vegetation types (natural and agricultural and in a consistent framework that produces estimates of carbon, agricultural and hydrological variables for the entire Mediterranean basin. This development pave the way for further model extensions aiming at the representation of alternative agro-ecosystems (e.g. agroforestry, and opens the door for a large number of applications in the Mediterranean region, for example assessments on the consequences of land use transitions, the influence of management practices and climate change impacts.

  3. Numerical Acoustic Models Including Viscous and Thermal losses: Review of Existing and New Methods

    DEFF Research Database (Denmark)

    Andersen, Peter Risby; Cutanda Henriquez, Vicente; Aage, Niels

    2017-01-01

    This work presents an updated overview of numerical methods including acoustic viscous and thermal losses. Numerical modelling of viscothermal losses has gradually become more important due to the general trend of making acoustic devices smaller. Not including viscothermal acoustic losses in such...

  4. Testing photobiomodulatory effects of laser irradiation on wound healing: development of an improved model for dressing wounds in mice.

    Science.gov (United States)

    Chung, Tzu-Yun; Peplow, Philip V; Baxter, G David

    2010-10-01

    To develop a suitable method for dressing skin wounds in BKS.Cg-m(+)/(+)Lepr(db) mice for subsequent use in laser irradiation of wounds. The healing of nonirradiated wounds (controls) was examined histologically to provide essential reference data. Dressing excisional skin wounds in mice has many advantages. However, previous studies using dressings such as Tegaderm W or OpSite, with or without adhesives, have shown that this is not easily achieved. In a pilot study, a full-thickness wound was made on the left flank in six diabetic and six nondiabetic mice, and five different methods were tried for dressing the wounds with Tegaderm HP to develop an optimized procedure. The optimized procedure was used in subsequent studies, with a total of 23 diabetic and 13 nondiabetic mice being controls for laser-irradiated mice. Measurements of healing outcomes from histologic sections of controls were statistically analyzed. The optimized procedure used Tegaderm HP with Cavilon and Fixomull Stretch strips for the first dressing, and with Mastisol for subsequent dressings. Wound closure by contraction was retarded in a large proportion of diabetic mice (approximately 80%) and a small proportion of nondiabetic mice. These wounds, described as "splinted," healed mainly by epithelial regeneration and granulation tissue formation. A simple, easy-to-perform procedure was developed for dressing wounds in diabetic and nondiabetic mice. It was found to cause splinting with wound healing mimicking that in human patients. This model is suitable for examining the effects of different therapies on wound healing, including lasers.

  5. Environmental enrichment attenuates behavioral abnormalities in valproic acid-exposed autism model mice.

    Science.gov (United States)

    Yamaguchi, Hiroshi; Hara, Yuta; Ago, Yukio; Takano, Erika; Hasebe, Shigeru; Nakazawa, Takanobu; Hashimoto, Hitoshi; Matsuda, Toshio; Takuma, Kazuhiro

    2017-08-30

    We recently demonstrated that prenatal exposure to valproic acid (VPA) at embryonic day 12.5 causes autism spectrum disorder (ASD)-like phenotypes such as hypolocomotion, anxiety-like behavior, social deficits and cognitive impairment in mice and that it decreases dendritic spine density in the hippocampal CA1 region. Previous studies show that some abnormal behaviors are improved by environmental enrichment in ASD rodent models, but it is not known whether environmental enrichment improves cognitive impairment. In the present study, we examined the effects of early environmental enrichment on behavioral abnormalities and neuromorphological changes in prenatal VPA-treated mice. We also examined the role of dendritic spine formation and synaptic protein expression in the hippocampus. Mice were housed for 4 weeks from 4 weeks of age under either a standard or enriched environment. Enriched housing was found to increase hippocampal brain-derived neurotrophic factor mRNA levels in both control and VPA-exposed mice. Furthermore, in VPA-treated mice, the environmental enrichment improved anxiety-like behavior, social deficits and cognitive impairment, but not hypolocomotion. Prenatal VPA treatment caused loss of dendritic spines in the hippocampal CA1 region and decreases in mRNA levels of postsynaptic density protein-95 and SH3 and multiple ankyrin repeat domains 2 in the hippocampus. These hippocampal changes were improved by the enriched housing. These findings suggest that the environmental enrichment improved most ASD-like behaviors including cognitive impairment in the VPA-treated mice by enhancing dendritic spine function. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Catalytic conversion of lignin pyrolysis model compound- guaiacol and its kinetic model including coke formation

    Science.gov (United States)

    Zhang, Huiyan; Wang, Yun; Shao, Shanshan; Xiao, Rui

    2016-11-01

    Lignin is the most difficult to be converted and most easy coking component in biomass catalytic pyrolysis to high-value liquid fuels and chemicals. Catalytic conversion of guaiacol as a lignin model compound was conducted in a fixed-bed reactor over ZSM-5 to investigate its conversion and coking behaviors. The effects of temperature, weight hourly space velocity (WHSV) and partial pressure on product distribution were studied. The results show the maximum aromatic carbon yield of 28.55% was obtained at temperature of 650 °C, WHSV of 8 h‑1 and partial pressure of 2.38 kPa, while the coke carbon yield was 19.55%. The reaction pathway was speculated to be removing methoxy group to form phenols with further aromatization to form aromatics. The amount of coke increased with increasing reaction time. The surface area and acidity of catalysts declined as coke formed on the acid sites and blocked the pore channels, which led to the decrease of aromatic yields. Finally, a kinetic model of guaiacol catalytic conversion considering coke deposition was built based on the above reaction pathway to properly predict product distribution. The experimental and model predicting data agreed well. The correlation coefficient of all equations were all higher than 0.90.

  7. Including operational data in QMRA model: development and impact of model inputs.

    Science.gov (United States)

    Jaidi, Kenza; Barbeau, Benoit; Carrière, Annie; Desjardins, Raymond; Prévost, Michèle

    2009-03-01

    A Monte Carlo model, based on the Quantitative Microbial Risk Analysis approach (QMRA), has been developed to assess the relative risks of infection associated with the presence of Cryptosporidium and Giardia in drinking water. The impact of various approaches for modelling the initial parameters of the model on the final risk assessments is evaluated. The Monte Carlo simulations that we performed showed that the occurrence of parasites in raw water was best described by a mixed distribution: log-Normal for concentrations > detection limit (DL), and a uniform distribution for concentrations risks significantly. The mean annual risks for conventional treatment are: 1.97E-03 (removal credit adjusted by log parasite = log spores), 1.58E-05 (log parasite = 1.7 x log spores) or 9.33E-03 (regulatory credits based on the turbidity measurement in filtered water). Using full scale validated SCADA data, the simplified calculation of CT performed at the plant was shown to largely underestimate the risk relative to a more detailed CT calculation, which takes into consideration the downtime and system failure events identified at the plant (1.46E-03 vs. 3.93E-02 for the mean risk).

  8. Plasmodium Berghei ANKA Infection in ICR Mice as a Model of Cerebral Malaria

    Directory of Open Access Journals (Sweden)

    F Othman

    2012-12-01

    Full Text Available Background: Animal models with various combination of host-parasite have long been employed to study malaria pathogenesis. Here, we describe the combination of Plasmodium berghei ANKA infec­tion in inbred ICR mice as a model of cerebral malaria (CM.Methods: Infection in mice was initiated by intraperitoneal injection of 2 x 107 (0.2ml parasitized red blood cells (PRBCs.Results: This model can produce a severe degree of infection presented by the high degree of parasitae­mia followed by death 6-7 days post infection. Severe anemia, splenomegaly, hepatomegaly and discolourations of major organs were observed. Histopathological findings revealed several impor­tant features mimicking human CM including, microvascular sequestration of PRBCs in major organs, particularly in the brain, hypertrophy and hyperplasia of the kupffer cells in the liver, pulmo­nary edema and hyaline membrane formation in the lungs and haemorrhages in the kidney’s medulla and cortex. Proinflammatory cytokines TNFα, IFNγ, IL-1, IL-6 and IL-18, and anti-inflammatory cytokine IL-10 were all found to be elevated in the plasma of infected mice.Conclusion: This model can reproduce many of the important features of CM and therefore can be used as a tool to advance our understanding of the disease pathogenesis.

  9. Generation of Pediatric Leukemia Xenograft Models in NSG-B2m Mice: Comparison with NOD/SCID Mice.

    Science.gov (United States)

    Gopalakrishnapillai, Anilkumar; Kolb, E Anders; Dhanan, Priyanka; Bojja, Aruna Sri; Mason, Robert W; Corao, Diana; Barwe, Sonali P

    2016-01-01

    Generation of orthotopic xenograft mouse models of leukemia is important to understand the mechanisms of leukemogenesis, cancer progression, its cross talk with the bone marrow microenvironment, and for preclinical evaluation of drugs. In these models, following intravenous injection, leukemic cells home to the bone marrow and proliferate there before infiltrating other organs, such as spleen, liver, and the central nervous system. Moreover, such models have been shown to accurately recapitulate the human disease and correlate with patient response to therapy and prognosis. Thus, various immune-deficient mice strains have been used with or without recipient preconditioning to increase engraftment efficiency. Mice homozygous for the severe combined immune deficiency (SCID) mutation and with non-obese diabetic background (NOD/SCID) have been used in the majority of leukemia xenograft studies. Later, NOD/SCID mice deficient for interleukin 2 receptor gamma chain (IL2Rγ) gene called NSG mice became the model of choice for leukemia xenografts. However, engraftment of leukemia cells without irradiation preconditioning still remained a challenge. In this study, we used NSG mice with null alleles for major histocompatibility complex class I beta2-microglobulin (β2m) called NSG-B2m. This is a first report describing the 100% engraftment efficiency of pediatric leukemia cell lines and primary samples in NSG-B2m mice in the absence of host preconditioning by sublethal irradiation. We also show direct comparison of the engraftment efficiency and growth rate of pediatric acute leukemia cells in NSG-B2m and NOD/SCID mice, which showed 80-90% engraftment efficiency. Secondary and tertiary xenografts in NSG-B2m mice generated by injection of cells isolated from the spleens of leukemia-bearing mice also behaved similar to the primary patient sample. We have successfully engrafted 25 acute lymphoblastic leukemia (ALL) and 5 acute myeloid leukemia (AML) patient samples with

  10. Physiologically based Pharmacokinetic Modeling of 1,4-Dioxane in Rats, Mice, and Humans

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, Lisa M.; Thrall, Karla D.; Poet, Torka S.; Corley, Rick; Weber, Thomas J.; Locey, B. J.; Clarkson, Jacquelyn; Sager, S.; Gargas, M. L.

    2008-01-01

    ABSTRACT 1,4-Dioxane (CAS No. 123-91-1) is used primarily as a solvent or as a solvent stabilizer. It can cause lung, liver and kidney damage at sufficiently high exposure levels. Two physiologically-based pharmacokinetic (PBPK) models of 1,4-dioxane and its major metabolite, hydroxyethoxyacetic acid (HEAA), were published in 1990. These models have uncertainties and deficiencies that could be addressed and the model strengthened for use in a contemporary cancer risk assessment for 1,4-dioxane. Studies were performed to fill data gaps and reduce uncertainties pertaining to the pharmacokinetics of 1,4-dioxane and HEAA in rats, mice, and humans. Three types of studies were performed:partition coefficient measurements, blood time course in mice, and in vitro pharmacokinetics using rat, mouse, and human hepatocytes. Updated PBPK models were developed based on these new data and previously available data. The optimized rate of metabolism for the mouse was significantly higher than the value previously estimated. The optimized rat kinetic parameters were similar to those in the 1990 models. Only two human studies were identified. Model predictions were consistent with one study, but did not fit the second as well. In addition, a rat nasal exposure was completed. The results confirmed water directly contacts rat nasal tissues during drinking water under bioassays. Consistent with previous PBPK models, nasal tissues were not specifically included in the model. Use of these models will reduce the uncertainty in future 1,4-dioxane risk assessments.

  11. Physiologically based pharmacokinetic modeling of 1,4-Dioxane in rats, mice, and humans.

    Science.gov (United States)

    Sweeney, Lisa M; Thrall, Karla D; Poet, Torka S; Corley, Richard A; Weber, Thomas J; Locey, Betty J; Clarkson, Jacquelyn; Sager, Shawn; Gargas, Michael L

    2008-01-01

    1,4-Dioxane (CAS No. 123-91-1) is used primarily as a solvent or as a solvent stabilizer. It can cause lung, liver, and kidney damage at sufficiently high exposure levels. Two physiologically based pharmacokinetic (PBPK) models of 1,4-dioxane and its major metabolite, hydroxyethoxyacetic acid (HEAA), were published in 1990. These models have uncertainties and deficiencies that could be addressed and the model strengthened for use in a contemporary cancer risk assessment for 1,4-dioxane. Studies were performed to fill data gaps and reduce uncertainties pertaining to the pharmacokinetics of 1,4-dioxane and HEAA in rats, mice, and humans. Three types of studies were performed: partition coefficient measurements, blood time course in mice, and in vitro pharmacokinetics using rat, mouse, and human hepatocytes. Updated PBPK models were developed based on these new data and previously available data. The optimized rate of metabolism for the mouse was significantly higher than the value previously estimated. The optimized rat kinetic parameters were similar to those in the 1990 models. Only two human studies were identified. Model predictions were consistent with one study, but did not fit the second as well. In addition, a rat nasal exposure was completed. The results confirmed water directly contacts rat nasal tissues during drinking water under bioassay conditions. Consistent with previous PBPK models, nasal tissues were not specifically included in the model. Use of these models will reduce the uncertainty in future 1,4-dioxane risk assessments.

  12. Nonlinear Modeling of a High Precision Servo Injection Molding Machine Including Novel Molding Approach

    Institute of Scientific and Technical Information of China (English)

    何雪松; 王旭永; 冯正进; 章志新; 杨钦廉

    2003-01-01

    A nonlinear mathematical model of the injection molding process for electrohydraulic servo injection molding machine (IMM) is developed.It was found necessary to consider the characteristics of asymmetric cylinder for electrohydraulic servo IMM.The model is based on the dynamics of the machine including servo valve,asymmetric cylinder and screw,and the non-Newtonian flow behavior of polymer melt in injection molding is also considered.The performance of the model was evaluated based on novel approach of molding - injection and compress molding,and the results of simulation and experimental data demonstrate the effectiveness of the model.

  13. a Better Description of Liquid Jet Breakup Using a Spatial Model Including Viscous Effects.

    Science.gov (United States)

    Hammerschlag, William Brian

    Theoretical models describing the operation and disintegration of a liquid jet are often based on an approximate solution of an inviscid jet in the temporal frame of reference. These models provide only a fair first order prediction of growth rate and breakoff length, and are based solely on a surface tension induced instability. A spatial model yielding jet growth rate and including both jet and surrounding atmosphere viscosity and density is now developed. This model is seen to reproduce all the features and limitations of the Weber viscous jet theory. When tested against experiments of water, water and glycerol mixes and binary eutectic tin/lead solder, only fair agreement is observed.

  14. Animal Models of Leptospirosis: Of Mice and Hamsters

    Science.gov (United States)

    Gomes-Solecki, Maria; Santecchia, Ignacio; Werts, Catherine

    2017-01-01

    Pathogenic Leptospira sp. are spirochetal bacteria responsible for leptospirosis, an emerging worldwide zoonosis. These spirochetes are very successful pathogens that infect a wide range of hosts such as fish, reptiles, birds, marsupials, and mammals. Transmission occurs when chronically infected animals excrete live bacteria in their urine, contaminating the environment. Leptospira sp. enter their hosts through damaged skin and mucosa. Chronically infected rats and mice are asymptomatic and are considered as important reservoirs of the disease. Infected humans may develop either a flu-like, usually mild illness with or without chronic asymptotic renal colonization, or a severe acute disease with kidney, liver, and heart failure, potentially leading to death. Leptospirosis is an economic burden on society due to health-care costs related to elevated morbidity of humans and loss of animals of agricultural interest. There are no effective vaccines against leptospirosis. Leptospira sp. are difficult to genetically manipulate which delays the pace of research progress. In this review, we discuss in an historical perspective how animal models have contributed to further our knowledge of leptospirosis. Hamsters, guinea pigs, and gerbils have been instrumental to study the pathophysiology of acute lethal leptospirosis and the Leptospira sp. genes involved in virulence. Chronic renal colonization has been mostly studied using experimentally infected rats. A special emphasis will be placed on mouse models, long thought to be irrelevant since they survive lethal infection. However, mice have recently been shown to be good models of sublethal infection leading to chronic colonization. Furthermore, congenic and transgenic mice have proven essential to study how innate immune cells interact with the pathogen and to understand the role of the toll-like receptor 4, which is important to control Leptospira sp. load and disease. The use of inbred and transgenic mouse models opens

  15. Fabrication, Testing and Modeling of the MICE Superconducting Spectrometer Solenoids

    Energy Technology Data Exchange (ETDEWEB)

    Virostek, S.P.; Green, M.A.; Trillaud, F.; Zisman, M.S.

    2010-05-16

    The Muon Ionization Cooling Experiment (MICE), an international collaboration sited at Rutherford Appleton Laboratory in the UK, will demonstrate ionization cooling in a section of realistic cooling channel using a muon beam. A five-coil superconducting spectrometer solenoid magnet will provide a 4 tesla uniform field region at each end of the cooling channel. Scintillating fiber trackers within the 400 mm diameter magnet bore tubes measure the emittance of the beam as it enters and exits the cooling channel. Each of the identical 3-meter long magnets incorporates a three-coil spectrometer magnet section and a two-coil section to match the solenoid uniform field into the other magnets of the MICE cooling channel. The cold mass, radiation shield and leads are currently kept cold by means of three two-stage cryocoolers and one single-stage cryocooler. Liquid helium within the cold mass is maintained by means of a re-condensation technique. After incorporating several design changes to improve the magnet cooling and reliability, the fabrication and acceptance testing of the spectrometer solenoids have proceeded. The key features of the spectrometer solenoid magnets, the development of a thermal model, the results of the recently completed tests, and the current status of the project are presented.

  16. A model of hemorrhagic cystitis induced with acrolein in mice

    Directory of Open Access Journals (Sweden)

    C.K.L.P. Batista

    2006-11-01

    Full Text Available Acrolein is a urinary metabolite of cyclophosphamide and ifosfamide, which has been reported to be the causative agent of hemorrhagic cystitis induced by these compounds. A direct cytotoxic effect of acrolein, however, has not yet been demonstrated. In the present study, the effects of intravesical injection of acrolein and mesna, the classical acrolein chemical inhibitor, were evaluated. Male Swiss mice weighing 25 to 35 g (N = 6 per group received saline or acrolein (25, 75, 225 µg intravesically 3, 6, 12, and 24 h before sacrifice for evaluation of bladder wet weight, macroscopic and histopathological changes by Gray's criteria, and 3 and 24 h for assessment of increase in vascular permeability. In other animals, mesna was administered intravesically (2 mg or systemically (80 mg/kg 1 h before acrolein. Intravesical administration of acrolein induced a dose- and time-dependent increase in vascular permeability and bladder wet weight (within 3 h: 2.2- and 21-fold increases in bladder wet weight and Evans blue dye exuded, respectively, at doses of 75 µg/bladder, as confirmed by Gray's criteria. Pretreatment with mesna (2-mercaptoethanesulfonic acid, which interacts with acrolein resulting in an inactive compound, inhibited all changes induced by acrolein. Our results are the first demonstration that intravesical administration of acrolein induces hemorrhagic cystitis. This model of acrolein-induced hemorrhagic cystitis in mice may be an important tool for the evaluation of the mechanism by which acrolein induces bladder lesion, as well as for investigation of new uroprotective drugs.

  17. A physiological model for simulation of benzene metabolism by rats and mice.

    Science.gov (United States)

    Medinsky, M A; Sabourin, P J; Lucier, G; Birnbaum, L S; Henderson, R F

    1989-06-15

    Studies conducted by the National Toxicology Program on the chronic toxicity of benzene indicated that B6C3F1 mice are more sensitive to the toxic effects of benzene than are F344 rats. A physiological model was developed to describe the uptake and metabolism of benzene in rats and mice and to determine if the observed differences in toxic effects could be explained by differences in the pathways for metabolism of benzene or by differences in uptake of benzene. Major pathways for elimination of benzene included metabolism to hydroquinone glucuronide or hydroquinone sulfate, phenyl glucuronide or phenyl sulfate, muconic acid, and prephenyl mercapturic acid or phenyl mercapturic acid. Model simulations for total benzene metabolized and for profiles of benzene metabolites were conducted for oral or inhalation exposure and compared to data for urinary excretion of benzene metabolites after exposure of rats and mice to [14C]- or [3H]-benzene by inhalation or gavage. Results for total amount of benzene metabolized, expressed per kilogram body weight, indicated that for inhalation exposure concentrations up to 1000 ppm, mice metabolized at least two to three times as much benzene as did rats. Simulations of oral exposure to benzene resulted in more benzene metabolized per kilogram body weight by rats at oral exposures of greater than 50 mg/kg. Patterns of metabolites formed after either route of exposure were very different for F344/N rats and B6C3F1 mice. Rats primarily formed the detoxification metabolite, phenyl sulfate. Mice formed hydroquinone glucuronide and muconic acid in addition to phenyl sulfate. Hydroquinone and muconic acid are associated with pathways leading to the formation of the putative toxic metabolites of benzene. Metabolic rate parameters, Vmax and Km, were very different for hydroquinone conjugate and muconic acid formation compared to formation of phenyl conjugates and phenyl mercapturic acids. Putative toxication pathways could be characterized as

  18. Including hydrological self-regulating processes in peatland models: Effects on peatmoss drought projections.

    Science.gov (United States)

    Nijp, Jelmer J; Metselaar, Klaas; Limpens, Juul; Teutschbein, Claudia; Peichl, Matthias; Nilsson, Mats B; Berendse, Frank; van der Zee, Sjoerd E A T M

    2017-02-15

    The water content of the topsoil is one of the key factors controlling biogeochemical processes, greenhouse gas emissions and biosphere - atmosphere interactions in many ecosystems, particularly in northern peatlands. In these wetland ecosystems, the water content of the photosynthetic active peatmoss layer is crucial for ecosystem functioning and carbon sequestration, and is sensitive to future shifts in rainfall and drought characteristics. Current peatland models differ in the degree in which hydrological feedbacks are included, but how this affects peatmoss drought projections is unknown. The aim of this paper was to systematically test whether the level of hydrological detail in models could bias projections of water content and drought stress for peatmoss in northern peatlands using downscaled projections for rainfall and potential evapotranspiration in the current (1991-2020) and future climate (2061-2090). We considered four model variants that either include or exclude moss (rain)water storage and peat volume change, as these are two central processes in the hydrological self-regulation of peatmoss carpets. Model performance was validated using field data of a peatland in northern Sweden. Including moss water storage as well as peat volume change resulted in a significant improvement of model performance, despite the extra parameters added. The best performance was achieved if both processes were included. Including moss water storage and peat volume change consistently reduced projected peatmoss drought frequency with >50%, relative to the model excluding both processes. Projected peatmoss drought frequency in the growing season was 17% smaller under future climate than current climate, but was unaffected by including the hydrological self-regulating processes. Our results suggest that ignoring these two fine-scale processes important in hydrological self-regulation of northern peatlands will have large consequences for projected climate change impact on

  19. Modeling an elastic beam with piezoelectric patches by including magnetic effects

    CERN Document Server

    Ozer, A O

    2014-01-01

    Models for piezoelectric beams using Euler-Bernoulli small displacement theory predict the dynamics of slender beams at the low frequency accurately but are insufficient for beams vibrating at high frequencies or beams with low length-to-width aspect ratios. A more thorough model that includes the effects of rotational inertia and shear strain, Mindlin-Timoshenko small displacement theory, is needed to predict the dynamics more accurately for these cases. Moreover, existing models ignore the magnetic effects since the magnetic effects are relatively small. However, it was shown recently \\cite{O-M1} that these effects can substantially change the controllability and stabilizability properties of even a single piezoelectric beam. In this paper, we use a variational approach to derive models that include magnetic effects for an elastic beam with two piezoelectric patches actuated by different voltage sources. Both Euler-Bernoulli and Mindlin-Timoshenko small displacement theories are considered. Due to the magne...

  20. Stability analysis of the extended ADI-FDTD technique including lumped models

    Institute of Scientific and Technical Information of China (English)

    CHEN ZhiHui; CHU QingXin

    2008-01-01

    The numerical stability of the extended alternating-direction-implicit-finite-difference-time-domain (ADI-FDTD) method including lumped models is analyzed.Three common lumped models are investigated:resistor,capacitor,and inductor,and three different formulations for each model are analyzed:the explicit,semi-implicit and implicit schemes.Analysis results show that the extended ADI-FDTD algorithm is not unconditionally stable in the explicit scheme case,and the stability criterion depends on the value of lumped models,but in the semi-implicit and implicit cases,the algorithm is stable.Finally,two simple microstrip circuits including lumped elements are simulated to demonstrate validity of the theoretical results.

  1. The Dynamic Modeling of Multiple Pairs of Spur Gears in Mesh, Including Friction and Geometrical Errors

    Directory of Open Access Journals (Sweden)

    Shengxiang Jia

    2003-01-01

    Full Text Available This article presents a dynamic model of three shafts and two pair of gears in mesh, with 26 degrees of freedom, including the effects of variable tooth stiffness, pitch and profile errors, friction, and a localized tooth crack on one of the gears. The article also details howgeometrical errors in teeth can be included in a model. The model incorporates the effects of variations in torsional mesh stiffness in gear teeth by using a common formula to describe stiffness that occurs as the gears mesh together. The comparison between the presence and absence of geometrical errors in teeth was made by using Matlab and Simulink models, which were developed from the equations of motion. The effects of pitch and profile errors on the resultant input pinion angular velocity coherent-signal of the input pinion's average are discussed by investigating some of the common diagnostic functions and changes to the frequency spectra results.

  2. SAMI2-PE: A model of the ionosphere including multistream interhemispheric photoelectron transport

    Science.gov (United States)

    Varney, R. H.; Swartz, W. E.; Hysell, D. L.; Huba, J. D.

    2012-06-01

    In order to improve model comparisons with recently improved incoherent scatter radar measurements at the Jicamarca Radio Observatory we have added photoelectron transport and energy redistribution to the two dimensional SAMI2 ionospheric model. The photoelectron model uses multiple pitch angle bins, includes effects associated with curved magnetic field lines, and uses an energy degradation procedure which conserves energy on coarse, non-uniformly spaced energy grids. The photoelectron model generates secondary electron production rates and thermal electron heating rates which are then passed to the fluid equations in SAMI2. We then compare electron and ion temperatures and electron densities of this modified SAMI2 model with measurements of these parameters over a range of altitudes from 90 km to 1650 km (L = 1.26) over a 24 hour period. The new electron heating model is a significant improvement over the semi-empirical model used in SAMI2. The electron temperatures above the F-peak from the modified model qualitatively reproduce the shape of the measurements as functions of time and altitude and quantitatively agree with the measurements to within ˜30% or better during the entire day, including during the rapid temperature increase at dawn.

  3. General spherical anisotropic Jeans models of stellar kinematics: including proper motions and radial velocities

    CERN Document Server

    Cappellari, Michele

    2015-01-01

    Cappellari (2008) presented a flexible and efficient method to model the stellar kinematics of anisotropic axisymmetric and spherical stellar systems. The spherical formalism could be used to model the line-of-sight velocity second moments allowing for essentially arbitrary radial variation in the anisotropy and general luminous and total density profiles. Here we generalize the spherical formalism by providing the expressions for all three components of the projected second moments, including the two proper motion components. A reference implementation is now included in the public JAM package available at http://purl.org/cappellari/software

  4. Modeling Within-Host Dynamics of Influenza Virus Infection Including Immune Responses

    OpenAIRE

    Pawelek, Kasia A.; Huynh, Giao T; Michelle Quinlivan; Ann Cullinane; Libin Rong; Perelson, Alan S.

    2012-01-01

    Influenza virus infection remains a public health problem worldwide. The mechanisms underlying viral control during an uncomplicated influenza virus infection are not fully understood. Here, we developed a mathematical model including both innate and adaptive immune responses to study the within-host dynamics of equine influenza virus infection in horses. By comparing modeling predictions with both interferon and viral kinetic data, we examined the relative roles of target cell availability, ...

  5. A lumped element transformer model including core losses and winding impedances

    OpenAIRE

    Ribbenfjärd, David

    2007-01-01

    In order to design a power transformer it is important to understand its internal electromagnetic behaviour. That can be obtained by measurements on physical transformers, analytical expressions and computer simulations. One benefit with simulations is that the transformer can be studied before it is built physically and that the consequences of changing dimensions and parameters easily can be tested. In this thesis a time-domain transformer model is presented. The model includes core losses ...

  6. Target echo strength modelling at FOI, including results from the BeTSSi II workshop

    CERN Document Server

    Östberg, Martin

    2016-01-01

    An overview of the target echo strength (TS) modelling capacity at the Swedish Defense Research Agency (FOI) is presented. The modelling methods described range from approximate ones, such as raytracing and Kirchhoff approximation codes, to high accuracy full field codes including boundary integral equation methods and finite elements methods. Illustrations of the applicability of the codes are given for a few simple cases tackled during the BeTTSi II (Benchmark Target Echo Strength Simulation) workshop held in Kiel 2014.

  7. Including leakage in network models: an application to calibrate leak valves in EPANET

    OpenAIRE

    Cobacho Jordán, Ricardo; Arregui de la Cruz, Francisco; Soriano Olivares, Javier; Cabrera Rochera, Enrique

    2015-01-01

    EPANET is one of the most widely used software packages for water network hydraulic modelling, and is especially interesting for educational and research purposes because it is in the public domain. However, EPANET simulations are demand-driven, and the program does not include a specific functionality to model water leakage, which is pressure-driven. Consequently, users are required to deal with this drawback by themselves. As a general solution for this problem, this paper presents a method...

  8. Key Characteristics of Combined Accident including TLOFW accident for PSA Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo Gyung; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of); Yoon, Ho Joon [Khalifa University of Science, Technology and Research, Abu Dhabi (United Arab Emirates)

    2015-05-15

    The conventional PSA techniques cannot adequately evaluate all events. The conventional PSA models usually focus on single internal events such as DBAs, the external hazards such as fire, seismic. However, the Fukushima accident of Japan in 2011 reveals that very rare event is necessary to be considered in the PSA model to prevent the radioactive release to environment caused by poor treatment based on lack of the information, and to improve the emergency operation procedure. Especially, the results from PSA can be used to decision making for regulators. Moreover, designers can consider the weakness of plant safety based on the quantified results and understand accident sequence based on human actions and system availability. This study is for PSA modeling of combined accidents including total loss of feedwater (TLOFW) accident. The TLOFW accident is a representative accident involving the failure of cooling through secondary side. If the amount of heat transfer is not enough due to the failure of secondary side, the heat will be accumulated to the primary side by continuous core decay heat. Transients with loss of feedwater include total loss of feedwater accident, loss of condenser vacuum accident, and closure of all MSIVs. When residual heat removal by the secondary side is terminated, the safety injection into the RCS with direct primary depressurization would provide alternative heat removal. This operation is called feed and bleed (F and B) operation. Combined accidents including TLOFW accident are very rare event and partially considered in conventional PSA model. Since the necessity of F and B operation is related to plant conditions, the PSA modeling for combined accidents including TLOFW accident is necessary to identify the design and operational vulnerabilities.The PSA is significant to assess the risk of NPPs, and to identify the design and operational vulnerabilities. Even though the combined accident is very rare event, the consequence of combined

  9. Analysis of a generalized model for influenza including differential susceptibility due to immunosuppression

    Science.gov (United States)

    Hincapié, Doracelly; Ospina, Juan

    2014-06-01

    Recently, a mathematical model of pandemic influenza was proposed including typical control strategies such as antivirals, vaccination and school closure; and considering explicitly the effects of immunity acquired from the early outbreaks on the ulterior outbreaks of the disease. In such model the algebraic expression for the basic reproduction number (without control strategies) and the effective reproduction number (with control strategies) were derived and numerically estimated. A drawback of this model of pandemic influenza is that it ignores the effects of the differential susceptibility due to immunosuppression and the effects of the complexity of the actual contact networks between individuals. We have developed a generalized model which includes such effects of heterogeneity. Specifically we consider the influence of the air network connectivity in the spread of pandemic influenza and the influence of the immunosuppresion when the population is divided in two immune classes. We use an algebraic expression, namely the Tutte polynomial, to characterize the complexity of the contact network. Until now, The influence of the air network connectivity in the spread of pandemic influenza has been studied numerically, but not algebraic expressions have been used to summarize the level of network complexity. The generalized model proposed here includes the typical control strategies previously mentioned (antivirals, vaccination and school closure) combined with restrictions on travel. For the generalized model the corresponding reproduction numbers will be algebraically computed and the effect of the contact network will be established in terms of the Tutte polynomial of the network.

  10. Generation and characterization of a mouse model of the metabolic syndrome: apolipoprotein E and aromatase double knockout mice.

    Science.gov (United States)

    Scott, Nicola J A; Cameron, Vicky A; Raudsepp, Sara; Lewis, Lynley K; Simpson, Evan R; Richards, A Mark; Ellmers, Leigh J

    2012-03-01

    The aim of this study was to create a comprehensive mouse model of the metabolic syndrome by crossing aromatase-deficient (ArKO) mice with apolipoprotein E-deficient (ApoE(-/-)) mice. Successive crossbreeding of ArKO with ApoE(-/-)-deficient mice generated double knockout, MetS-Tg mice. The phenotypic characteristics of the MetS-Tg mice were assessed at 3, 6, and 12 mo of age and compared with age- and sex-matched wild-type (WT) controls. Blood pressure and heart rate were recorded by a noninvasive, computerized tail-cuff system. Oral glucose and intraperitoneal insulin tolerance tests were performed. Serum cholesterol levels were measured by a combined quantitative colorimetric assay. Plasma adiponectin, C-reactive protein (CRP), insulin, interleukin-6 (IL-6), leptin, resistin, and tumor necrosis factor-α (TNF-α) were measured by multiplexed ELISA. MetS-Tg mice displayed significantly increased body weight, central obesity, and elevated blood pressure at all three ages compared with WT mice. Elevated serum cholesterol was associated with higher triglycerides and LDL/VLDL cholesterol particles and was accompanied by a decrease in HDL and histological evidence of fatty liver. MetS-Tg mice of all ages showed impaired glucose tolerance. At 12 mo, MetS-Tg mice had elevated plasma levels of CRP, IL-6, leptin, and TNF-α, but resistin levels were largely unchanged. We now report that this combination of gene knockouts produces a novel strain of mice that display the diverse clinical features of the metabolic syndrome, including central obesity, progressive hypertension, an adverse serum lipid profile, fatty liver, glucose intolerance, insulin resistance, and evidence of an inflammatory state.

  11. The No-Core Gamow Shell Model: Including the continuum in the NCSM

    CERN Document Server

    Barrett, B R; Michel, N; Płoszajczak, M

    2015-01-01

    We are witnessing an era of intense experimental efforts that will provide information about the properties of nuclei far from the line of stability, regarding resonant and scattering states as well as (weakly) bound states. This talk describes our formalism for including these necessary ingredients into the No-Core Shell Model by using the Gamow Shell Model approach. Applications of this new approach, known as the No-Core Gamow Shell Model, both to benchmark cases as well as to unstable nuclei will be given.

  12. The Watts-Strogatz network model developed by including degree distribution: theory and computer simulation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y W [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China); Zhang, L F [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China); Huang, J P [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China)

    2007-07-20

    By using theoretical analysis and computer simulations, we develop the Watts-Strogatz network model by including degree distribution, in an attempt to improve the comparison between characteristic path lengths and clustering coefficients predicted by the original Watts-Strogatz network model and those of the real networks with the small-world property. Good agreement between the predictions of the theoretical analysis and those of the computer simulations has been shown. It is found that the developed Watts-Strogatz network model can fit the real small-world networks more satisfactorily. Some other interesting results are also reported by adjusting the parameters in a model degree-distribution function. The developed Watts-Strogatz network model is expected to help in the future analysis of various social problems as well as financial markets with the small-world property.

  13. Dynamics Analysis of an HIV Infection Model including Infected Cells in an Eclipse Stage

    Directory of Open Access Journals (Sweden)

    Shengyu Zhou

    2013-01-01

    Full Text Available In this paper, an HIV infection model including an eclipse stage of infected cells is considered. Some quicker cells in this stage become productively infected cells, a portion of these cells are reverted to the uninfected class, and others will be latent down in the body. We consider CTL-response delay in this model and analyze the effect of time delay on stability of equilibrium. It is shown that the uninfected equilibrium and CTL-absent infection equilibrium are globally asymptotically stable for both ODE and DDE model. And we get the global stability of the CTL-present equilibrium for ODE model. For DDE model, we have proved that the CTL-present equilibrium is locally asymptotically stable in a range of delays and also have studied the existence of Hopf bifurcations at the CTL-present equilibrium. Numerical simulations are carried out to support our main results.

  14. Modeling of the dynamics of wind to power conversion including high wind speed behavior

    DEFF Research Database (Denmark)

    Litong-Palima, Marisciel; Bjerge, Martin Huus; Cutululis, Nicolaos Antonio

    2016-01-01

    of power system studies, but the idea of the proposed wind turbine model is to include the main dynamic effects in order to have a better representation of the fluctuations in the output power and of the fast power ramping especially because of high wind speed shutdowns of the wind turbine. The high wind......This paper proposes and validates an efficient, generic and computationally simple dynamic model for the conversion of the wind speed at hub height into the electrical power by a wind turbine. This proposed wind turbine model was developed as a first step to simulate wind power time series...... for power system studies. This paper focuses on describing and validating the single wind turbine model, and is therefore neither describing wind speed modeling nor aggregation of contributions from a whole wind farm or a power system area. The state-of-the-art is to use static power curves for the purpose...

  15. A statistical model including age to predict passenger postures in the rear seats of automobiles.

    Science.gov (United States)

    Park, Jangwoon; Ebert, Sheila M; Reed, Matthew P; Hallman, Jason J

    2016-06-01

    Few statistical models of rear seat passenger posture have been published, and none has taken into account the effects of occupant age. This study developed new statistical models for predicting passenger postures in the rear seats of automobiles. Postures of 89 adults with a wide range of age and body size were measured in a laboratory mock-up in seven seat configurations. Posture-prediction models for female and male passengers were separately developed by stepwise regression using age, body dimensions, seat configurations and two-way interactions as potential predictors. Passenger posture was significantly associated with age and the effects of other two-way interaction variables depended on age. A set of posture-prediction models are presented for women and men, and the prediction results are compared with previously published models. This study is the first study of passenger posture to include a large cohort of older passengers and the first to report a significant effect of age for adults. The presented models can be used to position computational and physical human models for vehicle design and assessment. Practitioner Summary: The significant effects of age, body dimensions and seat configuration on rear seat passenger posture were identified. The models can be used to accurately position computational human models or crash test dummies for older passengers in known rear seat configurations.

  16. Innovative Liner Concepts: Experiments and Impedance Modeling of Liners Including the Effect of Bias Flow

    Science.gov (United States)

    Kelly, Jeff; Betts, Juan Fernando; Fuller, Chris

    2000-01-01

    The study of normal impedance of perforated plate acoustic liners including the effect of bias flow was studied. Two impedance models were developed by modeling the internal flows of perforate orifices as infinite tubes with the inclusion of end corrections to handle finite length effects. These models assumed incompressible and compressible flows, respectively, between the far field and the perforate orifice. The incompressible model was used to predict impedance results for perforated plates with percent open areas ranging from 5% to 15%. The predicted resistance results showed better agreement with experiments for the higher percent open area samples. The agreement also tended to deteriorate as bias flow was increased. For perforated plates with percent open areas ranging from 1% to 5%, the compressible model was used to predict impedance results. The model predictions were closer to the experimental resistance results for the 2% to 3% open area samples. The predictions tended to deteriorate as bias flow was increased. The reactance results were well predicted by the models for the higher percent open area, but deteriorated as the percent open area was lowered (5%) and bias flow was increased. A fit was done on the incompressible model to the experimental database. The fit was performed using an optimization routine that found the optimal set of multiplication coefficients to the non-dimensional groups that minimized the least squares slope error between predictions and experiments. The result of the fit indicated that terms not associated with bias flow required a greater degree of correction than the terms associated with the bias flow. This model improved agreement with experiments by nearly 15% for the low percent open area (5%) samples when compared to the unfitted model. The fitted model and the unfitted model performed equally well for the higher percent open area (10% and 15%).

  17. Fusion rules for the logarithmic $N=1$ superconformal minimal models II: including the Ramond sector

    CERN Document Server

    Canagasabey, Michael

    2015-01-01

    The Virasoro logarithmic minimal models were intensively studied by several groups over the last ten years with much attention paid to the fusion rules and the structures of the indecomposable representations that fusion generates. The analogous study of the fusion rules of the $N=1$ superconformal logarithmic minimal models was initiated in arXiv:1504.03155 as a continuum counterpart to the lattice explorations of arXiv:1312.6763. These works restricted fusion considerations to Neveu-Schwarz representations. Here, this is extended to include the Ramond sector. Technical advances that make this possible include a fermionic Verlinde formula applicable to logarithmic conformal field theories and a twisted version of the fusion algorithm of Nahm and Gaberdiel-Kausch. The results include the first construction and detailed analysis of logarithmic structures in the Ramond sector.

  18. MEMLS3&a: Microwave Emission Model of Layered Snowpacks adapted to include backscattering

    Directory of Open Access Journals (Sweden)

    M. Proksch

    2015-08-01

    Full Text Available The Microwave Emission Model of Layered Snowpacks (MEMLS was originally developed for microwave emissions of snowpacks in the frequency range 5–100 GHz. It is based on six-flux theory to describe radiative transfer in snow including absorption, multiple volume scattering, radiation trapping due to internal reflection and a combination of coherent and incoherent superposition of reflections between horizontal layer interfaces. Here we introduce MEMLS3&a, an extension of MEMLS, which includes a backscatter model for active microwave remote sensing of snow. The reflectivity is decomposed into diffuse and specular components. Slight undulations of the snow surface are taken into account. The treatment of like- and cross-polarization is accomplished by an empirical splitting parameter q. MEMLS3&a (as well as MEMLS is set up in a way that snow input parameters can be derived by objective measurement methods which avoid fitting procedures of the scattering efficiency of snow, required by several other models. For the validation of the model we have used a combination of active and passive measurements from the NoSREx (Nordic Snow Radar Experiment campaign in Sodankylä, Finland. We find a reasonable agreement between the measurements and simulations, subject to uncertainties in hitherto unmeasured input parameters of the backscatter model. The model is written in Matlab and the code is publicly available for download through the following website: http://www.iapmw.unibe.ch/research/projects/snowtools/memls.html.

  19. MEMLS3&a: Microwave Emission Model of Layered Snowpacks adapted to include backscattering

    Directory of Open Access Journals (Sweden)

    M. Proksch

    2015-03-01

    Full Text Available The Microwave Emission Model of Layered Snowpacks (MEMLS was originally developed for microwave emissions of snowpacks in the frequency range 5–100 GHz. It is based on six-flux theory to describe radiative transfer in snow including absorption, multiple volume scattering, radiation trapping due to internal reflection and a combination of coherent and incoherent superposition of reflections between horizontal layer interfaces. Here we introduce MEMLS3&a, an extension of MEMLS, which includes a backscatter model for active microwave remote sensing of snow. The reflectivity is decomposed into diffuse and specular components. Slight undulations of the snow surface are taken into account. The treatment of like and cross polarization is accomplished by an empirical splitting parameter q. MEMLS3&a (as well as MEMLS is set up in a way that snow input parameters can be derived by objective measurement methods which avoids fitting procedures of the scattering efficiency of snow, required by several other models. For the validation of the model we have used a combination of active and passive measurements from the NoSREx campaign in Sodankylä, Finland. We find a reasonable agreement between the measurements and simulations, subject to uncertainties in hitherto unmeasured input parameters of the backscatter model. The model is written in MATLAB and the code is publicly available for download through the following website: http://www.iapmw.unibe.ch/research/projects/snowtools/memls.html.

  20. MEMLS3&a: Microwave Emission Model of Layered Snowpacks adapted to include backscattering

    Science.gov (United States)

    Proksch, M.; Mätzler, C.; Wiesmann, A.; Lemmetyinen, J.; Schwank, M.; Löwe, H.; Schneebeli, M.

    2015-08-01

    The Microwave Emission Model of Layered Snowpacks (MEMLS) was originally developed for microwave emissions of snowpacks in the frequency range 5-100 GHz. It is based on six-flux theory to describe radiative transfer in snow including absorption, multiple volume scattering, radiation trapping due to internal reflection and a combination of coherent and incoherent superposition of reflections between horizontal layer interfaces. Here we introduce MEMLS3&a, an extension of MEMLS, which includes a backscatter model for active microwave remote sensing of snow. The reflectivity is decomposed into diffuse and specular components. Slight undulations of the snow surface are taken into account. The treatment of like- and cross-polarization is accomplished by an empirical splitting parameter q. MEMLS3&a (as well as MEMLS) is set up in a way that snow input parameters can be derived by objective measurement methods which avoid fitting procedures of the scattering efficiency of snow, required by several other models. For the validation of the model we have used a combination of active and passive measurements from the NoSREx (Nordic Snow Radar Experiment) campaign in Sodankylä, Finland. We find a reasonable agreement between the measurements and simulations, subject to uncertainties in hitherto unmeasured input parameters of the backscatter model. The model is written in Matlab and the code is publicly available for download through the following website: http://www.iapmw.unibe.ch/research/projects/snowtools/memls.html.

  1. Diagnosing Lee Wave Rotor Onset Using a Linear Model Including a Boundary Layer

    Directory of Open Access Journals (Sweden)

    Miguel A. C. Teixeira

    2017-01-01

    Full Text Available A linear model is used to diagnose the onset of rotors in flow over 2D hills, for atmospheres that are neutrally stratified near the surface and stably stratified aloft, with a sharp temperature inversion in between, where trapped lee waves may propagate. This is achieved by coupling an inviscid two-layer mountain-wave model and a bulk boundary-layer model. The full model shows some ability to diagnose flow stagnation associated with rotors as a function of key input parameters, such as the Froude number and the height of the inversion, in numerical simulations and laboratory experiments carried out by previous authors. While calculations including only the effects of mean flow attenuation and velocity perturbation amplification within the surface layer represent flow stagnation fairly well in the more non-hydrostatic cases, only the full model, taking into account the feedback of the surface layer on the inviscid flow, satisfactorily predicts flow stagnation in the most hydrostatic case, although the corresponding condition is unable to discriminate between rotors and hydraulic jumps. Versions of the model not including this feedback severely underestimate the amplitude of trapped lee waves in that case, where the Fourier transform of the hill has zeros, showing that those waves are not forced directly by the orography.

  2. Steady-state analysis of activated sludge processes with a settler model including sludge compression.

    Science.gov (United States)

    Diehl, S; Zambrano, J; Carlsson, B

    2016-01-01

    A reduced model of a completely stirred-tank bioreactor coupled to a settling tank with recycle is analyzed in its steady states. In the reactor, the concentrations of one dominant particulate biomass and one soluble substrate component are modelled. While the biomass decay rate is assumed to be constant, growth kinetics can depend on both substrate and biomass concentrations, and optionally model substrate inhibition. Compressive and hindered settling phenomena are included using the Bürger-Diehl settler model, which consists of a partial differential equation. Steady-state solutions of this partial differential equation are obtained from an ordinary differential equation, making steady-state analysis of the entire plant difficult. A key result showing that the ordinary differential equation can be replaced with an approximate algebraic equation simplifies model analysis. This algebraic equation takes the location of the sludge-blanket during normal operation into account, allowing for the limiting flux capacity caused by compressive settling to easily be included in the steady-state mass balance equations for the entire plant system. This novel approach grants the possibility of more realistic solutions than other previously published reduced models, comprised of yet simpler settler assumptions. The steady-state concentrations, solids residence time, and the wastage flow ratio are functions of the recycle ratio. Solutions are shown for various growth kinetics; with different values of biomass decay rate, influent volumetric flow, and substrate concentration.

  3. Latest cosmological constraints on Cardassian expansion models including the updated gamma-ray bursts

    Institute of Scientific and Technical Information of China (English)

    Nan Liang; Pu-Xun Wua; Zong-Hong Zhu

    2011-01-01

    We constrain the Cardassian expansion models from the latest observations,including the updated Gamma-ray bursts (GRBs),which are calibrated using a cosmology independent method from the Union2 compilation of type Ia supernovae (SNe Ia).By combining the GRB data with the joint observations from the Union2SNe Ia set,along with the results from the Cosmic Microwave Background radiation observation from the seven-year Wilkinson Microwave Anisotropy Probe and the baryonic acoustic oscillation observation galaxy sample from the spectroscopic Sloan Digital Sky Survey Data Release,we find significant constraints on the model parameters of the original Cardassian model ΩM0=n 282+0.015-0.014,n=0.03+0.05-0.05;and n = -0.16+0.25-3.26,β=-0.76+0.34-0.58 of the modified polytropic Cardassian model,which are consistent with the ACDM model in a l-σ confidence region.From the reconstruction of the deceleration parameter q(z) in Cardassian models,we obtain the transition redshift ZT = 0.73 ± 0.04 for the original Cardassian model and ZT = 0.68 ± 0.04 for the modified polytropic Cardassian model.

  4. Safe distance car-following model including backward-looking and its stability analysis

    Science.gov (United States)

    Yang, Da; Jin, Peter Jing; Pu, Yun; Ran, Bin

    2013-03-01

    The focus of this paper is the car-following behavior including backward-looking, simply called the bi-directional looking car-following behavior. This study is motivated by the potential changes of the physical properties of traffic flow caused by the fast developing intelligent transportation system (ITS), especially the new connected vehicle technology. Existing studies on this topic focused on general motors (GM) models and optimal velocity (OV) models. The safe distance car-following model, Gipps' model, which is more widely used in practice have not drawn too much attention in the bi-directional looking context. This paper explores the property of the bi-directional looking extension of Gipps' safe distance model. The stability condition of the proposed model is derived using the linear stability theory and is verified using numerical simulations. The impacts of the driver and vehicle characteristics appeared in the proposed model on the traffic flow stability are also investigated. It is found that taking into account the backward-looking effect in car-following has three types of effect on traffic flow: stabilizing, destabilizing and producing non-physical phenomenon. This conclusion is more sophisticated than the study results based on the OV bi-directional looking car-following models. Moreover, the drivers who have the smaller reaction time or the larger additional delay and think the other vehicles have larger maximum decelerations can stabilize traffic flow.

  5. Firn Model Inter-Comparison Experiment (FirnMICE) (Invited)

    Science.gov (United States)

    Lundin, J.; Arthern, R. J.; Buizert, C.; Cummings, E.; Essery, R.; Ligtenberg, S.; Orsi, A. J.; Simonsen, S. B.; Brook, E.; Leahy, W.; Stevens, C.; Harris, P.; Waddington, E. D.

    2013-12-01

    Firn evolution plays important roles in glaciology; however, the physical formulation of the compaction law, including sensitivities to temperature and accumulation rate, is an active research topic. We forced 10 firn-densification models in 6 different experiments by altering temperature and accumulation-rate boundary conditions and compared the steady-state and transient behavior of the models. We find that the models produce different results in both steady-state and transient modes for a suite of metrics, including depth-density and depth-age profiles. We use this study to quantitatively characterize the differences between firn models; to provide a benchmark of results for future models; to provide a basis to quantify model uncertainties; and to guide future directions of firn-densification modeling.

  6. A Lumped Thermal Model Including Thermal Coupling and Thermal Boundary Conditions for High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2017-01-01

    Detailed thermal dynamics of high power IGBT modules are important information for the reliability analysis and thermal design of power electronic systems. However, the existing thermal models have their limits to correctly predict these complicated thermal behavior in the IGBTs: The typically used...... thermal distribution under long-term studies. Meanwhile the boundary conditions for the thermal analysis are modeled and included, which can be adapted to different real field applications of power electronic converters. Finally, the accuracy of the proposed thermal model is verified by FEM simulations...... thermal model based on one-dimensional RC lumps have limits to provide temperature distributions inside the device, moreover some variable factors in the real-field applications like the cooling and heating conditions of the converter cannot be adapted. On the other hand, the more advanced three...

  7. A Lumped Thermal Model Including Thermal Coupling and Thermal Boundary Conditions for High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2017-01-01

    Detailed thermal dynamics of high power IGBT modules are important information for the reliability analysis and thermal design of power electronic systems. However, the existing thermal models have their limits to correctly predict these complicated thermal behavior in the IGBTs: The typically used...... thermal distribution under long-term studies. Meanwhile the boundary conditions for the thermal analysis are modeled and included, which can be adapted to different real-field applications of power electronic converters. Finally, the accuracy of the proposed thermal model is verified by FEM simulations...... thermal model based on one-dimensional RC lumps have limits to provide temperature distributions inside the device, moreover some variable factors in the real-field applications like the cooling and heating conditions of the converter cannot be adapted. On the other hand, the more advanced three...

  8. Mottled Mice and Non-Mammalian Models of Menkes Disease.

    Science.gov (United States)

    Lenartowicz, Małgorzata; Krzeptowski, Wojciech; Lipiński, Paweł; Grzmil, Paweł; Starzyński, Rafał; Pierzchała, Olga; Møller, Lisbeth Birk

    2015-01-01

    Menkes disease is a multi-systemic copper metabolism disorder caused by mutations in the X-linked ATP7A gene and characterized by progressive neurodegeneration and severe connective tissue defects. The ATP7A protein is a copper (Cu)-transporting ATPase expressed in all tissues and plays a critical role in the maintenance of copper homeostasis in cells of the whole body. ATP7A participates in copper absorption in the small intestine and in copper transport to the central nervous system (CNS) across the blood-brain-barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB). Cu is essential for synaptogenesis and axonal development. In cells, ATP7A participates in the incorporation of copper into Cu-dependent enzymes during the course of its maturation in the secretory pathway. There is a high degree of homology (>80%) between the human ATP7A and murine Atp7a genes. Mice with mutations in the Atp7a gene, called mottled mutants, are well-established and excellent models of Menkes disease. Mottled mutants closely recapitulate the Menkes phenotype and are invaluable for studying Cu-metabolism. They provide useful models for exploring and testing new forms of therapy in Menkes disease. Recently, non-mammalian models of Menkes disease, Drosophila melanogaster and Danio rerio mutants were used in experiments which would be technically difficult to carry out in mammals.

  9. Mottled mice and non-mammalian models of Menkes disease

    Directory of Open Access Journals (Sweden)

    malgorzata elenartowicz

    2015-12-01

    Full Text Available Menkes disease is a multi-systemic copper metabolism disorder caused by mutations in the X-linked ATP7A gene and characterised by progressive neurodegeneration and severe connective tissue defects. The ATP7A protein is a Copper (Cu-transporting ATPase expressed in all tissues and plays a critical role in the maintenance of copper homeostasis in cells of the whole body. ATP7A participates in copper absorption in the small intestine and in copper transport to the CNS across the blood-brain-barrier and blood–cerebrospinal fluid- barrier. Cu is essential for synaptogenesis and axonal development. In cells, ATP7A participates in the incorporation of copper into Cu-dependent enzymes during the course of its maturation in the secretory pathway. There is a high degree of homology (>80% between the human ATP7A and murine Atp7a genes. Mice with mutations in the Atp7a gene, called mottled mutants, are well-established and excellent models of Menkes disease. Mottled mutants closely recapitulate the Menkes phenotype and are invaluable for studying Cu-metabolism. They provide useful models for exploring and testing new forms of therapy in Menkes disease. Recently, non-mammalian models of Menkes disease, Drosophila melanogaster and Danio rerio mutants were used in experiments which would be technically difficult to carry out in mammals.

  10. Effect of genistein on proinflammatory cytokines and estrogen receptor-β in mice model of endometriosis

    Institute of Scientific and Technical Information of China (English)

    Sutrisno Sutrisno; RR Catur Leny Wulandari; Dwi Wahyu Wulan Sulistyowati; Ratna Feti Wulandari; Endang Sri Wahyuni; Yuyun Yueniwati; Sanarto Santoso

    2015-01-01

    Objective: To investigate the effect of genistein on proinflammatory cytokines, NF-κB activation, and estrogen receptor-β expression in a mice model of endometriosis. Methods:Forty female mice (Mus musculus) were divided into eight groups (n=5 each), including the control (untreated) group, endometriosis group, and the endometriosis groups were given various doses of genistein (at doses of 50; 100; 200; 300; 400; 500 mg/day). Analysis of TNF-α, IL-1β, IL-6, and IL-8 level were done by ELISA technically. Analysis of estrogen receptor-β and NF-κB were done by immunohistochemistry. Results: The level of TNF-α, IL-1β, IL-6, and IL-8 were significantly higher in the EM group compared to the untreated control group (P0.05). These increased levels of IL-1β,IL-6, adn IL-8 in the EM group were significantly reduced by all doses of genistein. There were significantly (P0.05). All doses genistein significantly prevented EM-induced increase in NF-κB activation (P<0.05), to reach the expression on control group. Conclusion: In conclusion, genistein prohibits the increase in proinflammatory cytokines, NF-κB, and estrogen receptor-β expression in a mice model of endometriosis.

  11. Transmission line model for strained quantum well lasers including carrier transport and carrier heating effects.

    Science.gov (United States)

    Xia, Mingjun; Ghafouri-Shiraz, H

    2016-03-01

    This paper reports a new model for strained quantum well lasers, which are based on the quantum well transmission line modeling method where effects of both carrier transport and carrier heating have been included. We have applied this new model and studied the effect of carrier transport on the output waveform of a strained quantum well laser both in time and frequency domains. It has been found that the carrier transport increases the turn-on, turn-off delay times and damping of the quantum well laser transient response. Also, analysis in the frequency domain indicates that the carrier transport causes the output spectrum of the quantum well laser in steady state to exhibit a redshift which has a narrower bandwidth and lower magnitude. The simulation results of turning-on transients obtained by the proposed model are compared with those obtained by the rate equation laser model. The new model has also been used to study the effects of pump current spikes on the laser output waveforms properties, and it was found that the presence of current spikes causes (i) wavelength blueshift, (ii) larger bandwidth, and (iii) reduces the magnitude and decreases the side-lobe suppression ratio of the laser output spectrum. Analysis in both frequency and time domains confirms that the new proposed model can accurately predict the temporal and spectral behaviors of strained quantum well lasers.

  12. A numerical model including PID control of a multizone crystal growth furnace

    Science.gov (United States)

    Panzarella, Charles H.; Kassemi, Mohammad

    This paper presents a 2D axisymmetric combined conduction and radiation model of a multizone crystal growth furnace. The model is based on a programmable multizone furnace (PMZF) designed and built at NASA Lewis Research Center for growing high quality semiconductor crystals. A novel feature of this model is a control algorithm which automatically adjusts the power in any number of independently controlled heaters to establish the desired crystal temperatures in the furnace model. The control algorithm eliminates the need for numerous trial and error runs previously required to obtain the same results. The finite element code, FIDAP, used to develop the furnace model, was modified to directly incorporate the control algorithm. This algorithm, which presently uses PID control, and the associated heat transfer model are briefly discussed. Together, they have been used to predict the heater power distributions for a variety of furnace configurations and desired temperature profiles. Examples are included to demonstrate the effectiveness of the PID controlled model in establishing isothermal, Bridgman, and other complicated temperature profies in the sample. Finally, an example is given to show how the algorithm can be used to change the desired profile with time according to a prescribed temperature-time evolution.

  13. A continuum model of solvation energies including electrostatic, dispersion, and cavity contributions.

    Science.gov (United States)

    Duignan, Timothy T; Parsons, Drew F; Ninham, Barry W

    2013-08-15

    Physically accurate continuum solvent models that can calculate solvation energies are crucial to explain and predict the behavior of solute particles in water. Here, we present such a model applied to small spherical ions and neutral atoms. It improves upon a basic Born electrostatic model by including a standard cavity energy and adding a dispersion component, consistent with the Born electrostatic energy and using the same cavity size parameter. We show that the well-known, puzzling differences between the solvation energies of ions of the same size is attributable to the neglected dispersion contribution. This depends on dynamic polarizability as well as size. Generally, a large cancellation exists between the cavity and dispersion contributions. This explains the surprising success of the Born model. The model accurately reproduces the solvation energies of the alkali halide ions, as well as the silver(I) and copper(I) ions with an error of 12 kJ mol(-1) (±3%). The solvation energy of the noble gases is also reproduced with an error of 2.6 kJ mol(-1) (±30%). No arbitrary fitting parameters are needed to achieve this. This model significantly improves our understanding of ionic solvation and forms a solid basis for the investigation of other ion-specific effects using a continuum solvent model.

  14. Model for resistance evolution in shape memory alloys including R-phase

    Science.gov (United States)

    Brammajyosula, Ravindra; Buravalla, Vidyashankar; Khandelwal, Ashish

    2011-03-01

    The electrical resistance behavior of a shape memory alloy (SMA) wire can be used for sensing the state of an SMA device. Hence, this study investigates the resistance evolution in SMAs. A lumped parameter model with cosine kinetics to capture the resistance variation during the phase transformation is developed. Several SMA materials show the presence of trigonal or rhombohedral (R) phase as an intermediate phase, apart from the commonly recognized austenite and martensite phases. Most of the SMA models ignore the R-phase effect in their prediction of thermomechanical response. This may be acceptable since the changes in thermomechanical response associated with the R-phase are relatively less. However, the resistivity related effects are pronounced in the presence of the R-phase and its appearance introduces non-monotonicity in the resistivity evolution. This leads to additional complexities in the use of resistance signal for sensing and control. Hence, a lumped model is developed here for resistance evolution including the R-phase effects. A phase-diagram-based model is proposed for predicting electro-thermomechanical response. Both steady state hysteretic response and transient response are modeled. The model predictions are compared with the available test data. Numerical studies have shown that the model is able to capture all the essential features of the resistance evolution in SMAs in the presence of the R-phase.

  15. A New Circuit Model for Spin-Torque Oscillator Including Perpendicular Torque of Magnetic Tunnel Junction

    Directory of Open Access Journals (Sweden)

    Hyein Lim

    2013-01-01

    Full Text Available Spin-torque oscillator (STO is a promising new technology for the future RF oscillators, which is based on the spin-transfer torque (STT effect in magnetic multilayered nanostructure. It is expected to provide a larger tunability, smaller size, lower power consumption, and higher level of integration than the semiconductor-based oscillators. In our previous work, a circuit-level model of the giant magnetoresistance (GMR STO was proposed. In this paper, we present a physics-based circuit-level model of the magnetic tunnel junction (MTJ-based STO. MTJ-STO model includes the effect of perpendicular torque that has been ignored in the GMR-STO model. The variations of three major characteristics, generation frequency, mean oscillation power, and generation linewidth of an MTJ-STO with respect to the amount of perpendicular torque, are investigated, and the results are applied to our model. The operation of the model was verified by HSPICE simulation, and the results show an excellent agreement with the experimental data. The results also prove that a full circuit-level simulation with MJT-STO devices can be made with our proposed model.

  16. Does including physiology improve species distribution model predictions of responses to recent climate change?

    Science.gov (United States)

    Buckley, Lauren B; Waaser, Stephanie A; MacLean, Heidi J; Fox, Richard

    2011-12-01

    Thermal constraints on development are often invoked to predict insect distributions. These constraints tend to be characterized in species distribution models (SDMs) by calculating development time based on a constant lower development temperature (LDT). Here, we assessed whether species-specific estimates of LDT based on laboratory experiments can improve the ability of SDMs to predict the distribution shifts of six U.K. butterflies in response to recent climate warming. We find that species-specific and constant (5 degrees C) LDT degree-day models perform similarly at predicting distributions during the period of 1970-1982. However, when the models for the 1970-1982 period are projected to predict distributions in 1995-1999 and 2000-2004, species-specific LDT degree-day models modestly outperform constant LDT degree-day models. Our results suggest that, while including species-specific physiology in correlative models may enhance predictions of species' distribution responses to climate change, more detailed models may be needed to adequately account for interspecific physiological differences.

  17. Modeling of single char combustion, including CO oxidation in its boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.H.; Longwell, J.P.; Sarofim, A.F.

    1994-10-25

    The combustion of a char particle can be divided into a transient phase where its temperature increases as it is heated by oxidation, and heat transfer from the surrounding gas to an approximately constant temperature stage where gas phase reaction is important and which consumes most of the carbon and an extinction stage caused by carbon burnout. In this work, separate models were developed for the transient heating where gas phase reactions were unimportant and for the steady temperature stage where gas phase reactions were treated in detail. The transient char combustion model incorporates intrinsic char surface production of CO and CO{sub 2}, internal pore diffusion and external mass and heat transfer. The model provides useful information for particle ignition, burning temperature profile, combustion time, and carbon consumption rate. A gas phase reaction model incorporating the full set of 28 elementary C/H/O reactions was developed. This model calculated the gas phase CO oxidation reaction in the boundary layer at particle temperatures of 1250 K and 2500 K by using the carbon consumption rate and the burning temperature at the pseudo-steady state calculated from the temperature profile model but the transient heating was not included. This gas phase model can predict the gas species, and the temperature distributions in the boundary layer, the CO{sub 2}/CO ratio, and the location of CO oxidation. A mechanistic heat and mass transfer model was added to the temperature profile model to predict combustion behavior in a fluidized bed. These models were applied to data from the fluidized combustion of Newlands coal char particles. 52 refs., 60 figs.

  18. Including source uncertainty and prior information in the analysis of stable isotope mixing models.

    Science.gov (United States)

    Ward, Eric J; Semmens, Brice X; Schindler, Daniel E

    2010-06-15

    Stable isotope mixing models offer a statistical framework for estimating the contribution of multiple sources (such as prey) to a mixture distribution. Recent advances in these models have estimated the source proportions using Bayesian methods, but have not explicitly accounted for uncertainty in the mean and variance of sources. We demonstrate that treating these quantities as unknown parameters can reduce bias in the estimated source contributions, although model complexity is increased (thereby increasing the variance of estimates). The advantages of this fully Bayesian approach are particularly apparent when the source geometry is poor or sample sizes are small. A second benefit to treating source quantities as parameters is that prior source information can be included. We present findings from 9 lake food-webs, where the consumer of interest (fish) has a diet composed of 5 sources: aquatic insects, snails, zooplankton, amphipods, and terrestrial insects. We compared the traditional Bayesian stable isotope mixing model with fixed source parameters to our fully Bayesian model-with and without an informative prior. The informative prior has much less impact than the choice of model-the traditional mixing model with fixed source parameters estimates the diet to be dominated by aquatic insects, while the fully Bayesian model estimates the diet to be more balanced but with greater importance of zooplankton. The findings from this example demonstrate that there can be stark differences in inference between the two model approaches, particularly when the source geometry of the mixing model is poor. These analyses also emphasize the importance of investing substantial effort toward characterizing the variation in the isotopic characteristics of source pools to appropriately quantify uncertainties in their contributions to consumers in food webs.

  19. Kinetic modeling of rhamnolipid production by Pseudomonas aeruginosa PAO1 including cell density-dependent regulation.

    Science.gov (United States)

    Henkel, Marius; Schmidberger, Anke; Vogelbacher, Markus; Kühnert, Christian; Beuker, Janina; Bernard, Thomas; Schwartz, Thomas; Syldatk, Christoph; Hausmann, Rudolf

    2014-08-01

    The production of rhamnolipid biosurfactants by Pseudomonas aeruginosa is under complex control of a quorum sensing-dependent regulatory network. Due to a lack of understanding of the kinetics applicable to the process and relevant interrelations of variables, current processes for rhamnolipid production are based on heuristic approaches. To systematically establish a knowledge-based process for rhamnolipid production, a deeper understanding of the time-course and coupling of process variables is required. By combining reaction kinetics, stoichiometry, and experimental data, a process model for rhamnolipid production with P. aeruginosa PAO1 on sunflower oil was developed as a system of coupled ordinary differential equations (ODEs). In addition, cell density-based quorum sensing dynamics were included in the model. The model comprises a total of 36 parameters, 14 of which are yield coefficients and 7 of which are substrate affinity and inhibition constants. Of all 36 parameters, 30 were derived from dedicated experimental results, literature, and databases and 6 of them were used as fitting parameters. The model is able to describe data on biomass growth, substrates, and products obtained from a reference batch process and other validation scenarios. The model presented describes the time-course and interrelation of biomass, relevant substrates, and products on a process level while including a kinetic representation of cell density-dependent regulatory mechanisms.

  20. A Model of Left Ventricular Dysfunction Complicated by CAWS Arteritis in DBA/2 Mice

    Directory of Open Access Journals (Sweden)

    Naoto Hirata

    2012-01-01

    Full Text Available It was reported previously that a Candida albicans water-soluble fraction (CAWS, including a mannoprotein and β-glucan complex, has strong potency in inducing fatal necrotizing arteritis in DBA/2 mice. In this study, histopathological changes and cardiac function were investigated in this system. One mg/day of CAWS was given to DBA/2 mice via peritoneal injection for five days. The CAWS-treated DBA/2 mice were induced aortitis and died at an incidence of 100% within several weeks. Histological findings included stenosis in the left ventricular outflow tract (LVOT and severe inflammatory changes of the aortic valve with fibrinoid necrosis. Cardiomegaly was observed and heart weight increased 1.62 fold (<0.01. Echocardiography revealed a severe reduction in contractility and dilatation of the cavity in the left ventricle (LV: LV fractional shortening (LVFS decreased from 71% to 38% (<0.01, and the LV end-diastolic diameter (LVDd increased from 2.21 mm to 3.26 mm (<0.01. The titer of BNP mRNA increased in the CAWS-treated group. Severe inflammatory changes resulting from CAWS brought about lethal LV dysfunction by aortic valve deformation with LVOT stenosis. This system is proposed as an easy and useful experimental model of heart failure because CAWS arteritis can be induced by CAWS injection alone.

  1. Codigestion of solid wastes: a review of its uses and perspectives including modeling.

    Science.gov (United States)

    Mata-Alvarez, Joan; Dosta, Joan; Macé, Sandra; Astals, Sergi

    2011-06-01

    The last two years have witnessed a dramatic increase in the number of papers published on the subject of codigestion, highlighting the relevance of this topic within anaerobic digestion research. Consequently, it seems appropriate to undertake a review of codigestion practices starting from the late 1970s, when the first papers related to this concept were published, and continuing to the present day, demonstrating the exponential growth in the interest shown in this approach in recent years. Following a general analysis of the situation, state-of-the-art codigestion is described, focusing on the two most important areas as regards publication: codigestion involving sewage sludge and the organic fraction of municipal solid waste (including a review of the secondary advantages for wastewater treatment plant related to biological nutrient removal), and codigestion in the agricultural sector, that is, including agricultural - farm wastes, and energy crops. Within these areas, a large number of oversized digesters appear which can be used to codigest other substrates, resulting in economic and environmental advantages. Although the situation may be changing, there is still a need for good examples on an industrial scale, particularly with regard to wastewater treatment plants, in order to extend this beneficial practice. In the last section, a detailed analysis of papers addressing the important aspect of modelisation is included. This analysis includes the first codigestion models to be developed as well as recent applications of the standardised anaerobic digestion model ADM1 to codigestion. (This review includes studies ranging from laboratory to industrial scale.).

  2. Enhanced UWB Radio Channel Model for Short-Range Communication Scenarios Including User Dynamics

    DEFF Research Database (Denmark)

    Kovacs, Istvan Zsolt; Nguyen, Tuan Hung; Eggers, Patrick Claus F.

    2005-01-01

    In this paper we propose a SISO UWB radio channel model for short-range radio link scenarios between a fixed device and a dynamic user hand-held device. The channel model is derived based on novel experimental UWB radio propagation investigations carried out in typical indoor PAN scenarios...... including realistic device and user terminal antenna configurations. The radio channel measurements have been performed in the lower UWB frequency band of 3GHz to 5GHz with a 2x4 MIMO antenna configuration. Several environments, user scenarios and two types of user terminals have been used. The developed...

  3. Fuzzy Control of Yaw and Roll Angles of a Simulated Helicopter Model Includes Articulated Manipulators

    Directory of Open Access Journals (Sweden)

    Hossein Sadegh Lafmejani

    2015-09-01

    Full Text Available Fuzzy logic controller (FLC is a heuristic method by If-Then Rules which resembles human intelligence and it is a good method for designing Non-linear control systems. In this paper, an arbitrary helicopter model includes articulated manipulators has been simulated with Matlab SimMechanics toolbox. Due to the difficulties of modeling this complex system, a fuzzy controller with simple fuzzy rules has been designed for its yaw and roll angles in order to stabilize the helicopter while it is in the presence of disturbances or its manipulators are moving for a task. Results reveal that a simple FLC can appropriately control this system.

  4. Including Finite Surface Span Effects in Empirical Jet-Surface Interaction Noise Models

    Science.gov (United States)

    Brown, Clifford A.

    2016-01-01

    The effect of finite span on the jet-surface interaction noise source and the jet mixing noise shielding and reflection effects is considered using recently acquired experimental data. First, the experimental setup and resulting data are presented with particular attention to the role of surface span on far-field noise. These effects are then included in existing empirical models that have previously assumed that all surfaces are semi-infinite. This extended abstract briefly describes the experimental setup and data leaving the empirical modeling aspects for the final paper.

  5. Analytical model for investigation of interior noise characteristics in aircraft with multiple propellers including synchrophasing

    Science.gov (United States)

    Fuller, C. R.

    1986-01-01

    A simplified analytical model of transmission of noise into the interior of propeller-driven aircraft has been developed. The analysis includes directivity and relative phase effects of the propeller noise sources, and leads to a closed form solution for the coupled motion between the interior and exterior fields via the shell (fuselage) vibrational response. Various situations commonly encountered in considering sound transmission into aircraft fuselages are investigated analytically and the results obtained are compared to measurements in real aircraft. In general the model has proved successful in identifying basic mechanisms behind noise transmission phenomena.

  6. Morphology and MMP-9, AR and IGFR-1 responses of the seminal vesicle in TRAMP mice model.

    Science.gov (United States)

    Dal Pozzo, Caroline Fernanda Sanches; Kido, Larissa Akemi; Montico, Fabio; Gonçalves, Mariana Piccoli; Cagnon, Valéria Helena Alves

    2016-06-01

    Seminal vesicles are important hormone-dependent accessory sex glands. Transgenic adenocarcinoma of the mouse prostate (TRAMP) model has been used to evaluate malignant diseases in the prostate and in other sexual glands. The aim of this study was to characterize structural and molecular features of the seminal vesicle in different life periods of the TRAMP mice. Groups: Control Group (5 FVB/12 week old mice), TRAMP 12 and 22 Groups (10 TRAMP 12 and 22 week old mice, respectively). Seminal vesicles were evaluated by morphological and immunohistochemical parameters; androgenic receptor (AR), Insulin-like growth factor 1 (IGFR-1) and metalloproteinase 9 (MMP-9). The TRAMP mice showed frequent epithelial proliferation, including cellular stromal invasion, especially in the TRAMP 22 group. Intense AR reactivity was seen in both stroma and epithelial regions in the TRAMP 22 group. Intense IGFR-1 and MMP-9 stromal immunolabeling was identified in both TRAMP groups. Thus, there were structural and molecular changes in the seminal vesicle in TRAMP mice, compromising not only the structure but also the stromal signaling, damaging thus the function and leading to glandular lesions. TRAMP mice could be indicated as a good model to study alterations of the seminal vesicle in association to prostate cancer.

  7. An air/sea flux model including the effects of capillary waves

    Science.gov (United States)

    Bourassa, Mark A.

    1993-01-01

    An improved model of the air/sea interface is developed. The improvements consist in including the effect of capillary (surface tension) waves on the tropical surface fluxes and the consideration of the sea state, both of which increase the magnitude of tropical surface fluxes. Changes in surface stress are most significant in the low wind-speed regions, which include the areas where westerly bursts occur. It is shown that the changes, from the regular wind conditions to those of a westerly burst or El-Nino, can double when the effects of capillary waves are considered. This implies a much stronger coupling between the ocean and the atmosphere than is predicted by other boundary layer models.

  8. A complete model of CH+ rotational excitation including radiative and chemical pumping processes

    CERN Document Server

    Godard, Benjamin

    2012-01-01

    Aims. Excitation of far-infrared and submillimetric molecular lines may originate from nonreactive collisions, chemical formation, or far infrared, near-infrared, and optical fluorescences. As a template, we investigate the impact of each of these processes on the excitation of the methylidyne cation CH+ and on the intensities of its rotational transitions recently detected in emission in dense photodissociation regions (PDRs) and in planetary nebulae. Methods. We have developed a nonlocal thermodynamic equilibrium (non-LTE) excitation model that includes the entire energy structure of CH+, i.e. taking into account the pumping of its vibrational and bound and unbound electronic states by near-infrared and optical photons. The model includes the theoretical cross-sections of nonreactive collisions with H, H2, He, and e-, and a Boltzmann distribution is used to describe the probability of populating the excited levels of CH+ during its chemical formation by hydrogenation of C+. To confirm our results we also pe...

  9. Including Flocculation in a Numerical Sediment Transport Model for a Partially-Mixed Estuary

    Science.gov (United States)

    Tarpley, D.; Harris, C. K.; Friedrichs, C. T.

    2016-12-01

    Particle settling velocity impacts the transport of suspended sediment to the first order but fine-grained material like muds tend to form loosely bound aggregates (flocs) whose settling velocity can vary widely. Properties of flocculated sediment such as settling velocity and particle density are difficult to predict because they change in response to several factors including salinity, suspended sediment concentration, turbulent mixing, and organic content. Knowledge of the mechanisms governing flocculation of cohesive sediment is rapidly expanding; especially in response to recent technical advances. As the understanding of particle dynamics progresses, numerical models describing flocculation and break-up are being developed with varying degrees of complexity. While complex models capture the dynamics of the system, their computational costs may prohibit their incorporation into larger model domains. It is important to determine if the computational costs of intricate floc models are justifiable compared to simpler formulations. For this study, we implement an idealized two-dimensional model designed to represent a longitudinal section of a partially mixed estuary that neglects across-channel variation but exhibits salinity driven estuarine circulation. The idealized domain is designed to mimic the primary features of the York River, VA. Suspended load, erosion and deposition are calculated within the sediment transport routines of the COAWST modeling system. We compare different methods for prescribing settling velocity of fine-grained material. The simplest, standard model neglects flocculation dynamics while the complex treatment is a size-class-based flocculation model (FLOCMOD). Differences in tidal and daily averages of suspended load, bulk settling velocity and bed deposition are compared between the standard and FLOCMOD runs, to examine the relative impact of flocculation on sediment transport patterns. We expect FLOCMOD to have greater variability and

  10. Multistate Statistical Modeling: A Tool to Build a Lung Cancer Microsimulation Model That Includes Parameter Uncertainty and Patient Heterogeneity.

    Science.gov (United States)

    Bongers, Mathilda L; de Ruysscher, Dirk; Oberije, Cary; Lambin, Philippe; Uyl-de Groot, Carin A; Coupé, V M H

    2016-01-01

    With the shift toward individualized treatment, cost-effectiveness models need to incorporate patient and tumor characteristics that may be relevant to treatment planning. In this study, we used multistate statistical modeling to inform a microsimulation model for cost-effectiveness analysis of individualized radiotherapy in lung cancer. The model tracks clinical events over time and takes patient and tumor features into account. Four clinical states were included in the model: alive without progression, local recurrence, metastasis, and death. Individual patients were simulated by repeatedly sampling a patient profile, consisting of patient and tumor characteristics. The transitioning of patients between the health states is governed by personalized time-dependent hazard rates, which were obtained from multistate statistical modeling (MSSM). The model simulations for both the individualized and conventional radiotherapy strategies demonstrated internal and external validity. Therefore, MSSM is a useful technique for obtaining the correlated individualized transition rates that are required for the quantification of a microsimulation model. Moreover, we have used the hazard ratios, their 95% confidence intervals, and their covariance to quantify the parameter uncertainty of the model in a correlated way. The obtained model will be used to evaluate the cost-effectiveness of individualized radiotherapy treatment planning, including the uncertainty of input parameters. We discuss the model-building process and the strengths and weaknesses of using MSSM in a microsimulation model for individualized radiotherapy in lung cancer.

  11. Model for safety reports including descriptive examples; Mall foer saekerhetsrapporter med beskrivande exempel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    Several safety reports will be produced in the process of planning and constructing the system for disposal of high-level radioactive waste in Sweden. The present report gives a model, with detailed examples, of how these reports should be organized and what steps they should include. In the near future safety reports will deal with the encapsulation plant and the repository. Later reports will treat operation of the handling systems and the repository.

  12. Extending the formal model of a spatial data infrastructure to include volunteered geographical information

    CSIR Research Space (South Africa)

    Cooper, Antony K

    2011-07-01

    Full Text Available an aggregator of VGI, such as Ushahidi, and the provider of the infrastructure for collecting VGI, such as OpenStreetMap. 3) Broker: A stakeholder who brings End Users and Providers together and assists in the negotiation of contracts between them... model of a spatial data infrastructure to include volunteered geographical information Antony K Cooper*, Petr Rapant?, Jan Hjelmager?, Dominique Laurent?, Adam Iwaniak#, Serena Coetzee$, Harold Moellering? and Ulrich D?ren? *Logistics...

  13. QCD Equation of State From a Chiral Hadronic Model Including Quark Degrees of Freedom

    CERN Document Server

    Rau, Philip; Schramm, Stefan; Stöcker, Horst

    2013-01-01

    This work presents an effective model for strongly interacting matter and the QCD equation of state (EoS). The model includes both hadron and quark degrees of freedom and takes into account the transition of chiral symmetry restoration as well as the deconfinement phase transition. At low temperatures $T$ and baryonic densities $\\rho_B$ a hadron resonance gas is described using a SU(3)-flavor sigma-omega model and a quark phase is introduced in analogy to PNJL models for higher $T$ and $\\rho_B$. In this way, the correct asymptotic degrees of freedom are used in a wide range of $T$ and $\\rho_B$. Here, results of this model concerning the chiral and deconfinement phase transitions and thermodynamic model properties are presented. Large hadron resonance multiplicities in the transition region emphasize the importance of heavy-mass resonance states in this region and their impact on the chiral transition behavior. The resulting phase diagram of QCD matter at small chemical potentials is in line with latest lattic...

  14. A full model for simulation of electrochemical cells including complex behavior

    Science.gov (United States)

    Esperilla, J. J.; Félez, J.; Romero, G.; Carretero, A.

    This communication presents a model of electrochemical cells developed in order to simulate their electrical, chemical and thermal behavior showing the differences when thermal effects are or not considered in the charge-discharge process. The work presented here has been applied to the particular case of the Pb,PbSO 4|H 2SO 4 (aq)|PbO 2,Pb cell, which forms the basis of the lead-acid batteries so widely used in the automotive industry and as traction batteries in electric or hybrid vehicles. Each half-cell is considered independently in the model. For each half-cell, in addition to the main electrode reaction, a secondary reaction is considered: the hydrogen evolution reaction in the negative electrode and the oxygen evolution reaction in the positive. The equilibrium potential is calculated with the Nernst equation, in which the activity coefficients are fitted to an exponential function using experimental data. On the other hand, the two main mechanisms that produce the overpotential are considered, that is the activation or charge transfer and the diffusion mechanisms. First, an isothermal model has been studied in order to show the behavior of the main phenomena. A more complex model has also been studied including thermal behavior. This model is very useful in the case of traction batteries in electric and hybrid vehicles where high current intensities appear. Some simulation results are also presented in order to show the accuracy of the proposed models.

  15. A High-Rate, Single-Crystal Model including Phase Transformations, Plastic Slip, and Twinning

    Energy Technology Data Exchange (ETDEWEB)

    Addessio, Francis L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Bronkhorst, Curt Allan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Bolme, Cynthia Anne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Explosive Science and Shock Physics Division; Brown, Donald William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Cerreta, Ellen Kathleen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Lebensohn, Ricardo A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Lookman, Turab [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Luscher, Darby Jon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Mayeur, Jason Rhea [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Morrow, Benjamin M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Rigg, Paulo A. [Washington State Univ., Pullman, WA (United States). Dept. of Physics. Inst. for Shock Physics

    2016-08-09

    An anisotropic, rate-­dependent, single-­crystal approach for modeling materials under the conditions of high strain rates and pressures is provided. The model includes the effects of large deformations, nonlinear elasticity, phase transformations, and plastic slip and twinning. It is envisioned that the model may be used to examine these coupled effects on the local deformation of materials that are subjected to ballistic impact or explosive loading. The model is formulated using a multiplicative decomposition of the deformation gradient. A plate impact experiment on a multi-­crystal sample of titanium was conducted. The particle velocities at the back surface of three crystal orientations relative to the direction of impact were measured. Molecular dynamics simulations were conducted to investigate the details of the high-­rate deformation and pursue issues related to the phase transformation for titanium. Simulations using the single crystal model were conducted and compared to the high-­rate experimental data for the impact loaded single crystals. The model was found to capture the features of the experiments.

  16. A 3D model of the oculomotor plant including the pulley system

    Energy Technology Data Exchange (ETDEWEB)

    Viegener, A; Armentano, R L [Fundacion Universitaria Dr. Rene G. Favaloro, SolIs 453 (1078) Buenos Aires (Argentina)

    2007-11-15

    Early models of the oculomotor plant only considered the eye globes and the muscles that move them. Recently, connective tissue structures have been found enveloping the extraocular muscles (EOMs) and firmly anchored to the orbital wall. These structures act as pulleys; they determine the functional origin of the EOMs and, in consequence, their effective pulling direction. A three dimensional model of the oculomotor plant, including pulleys, has been developed and simulations in Simulink were performed during saccadic eye movements. Listing's law was implemented based on the supposition that there exists an eye orientation related signal. The inclusion of the pulleys in the model makes this assumption plausible and simplifies the problem of the plant noncommutativity.

  17. A flexible and qualitatively stable model for cell cycle dynamics including DNA damage effects.

    Science.gov (United States)

    Jeffries, Clark D; Johnson, Charles R; Zhou, Tong; Simpson, Dennis A; Kaufmann, William K

    2012-01-01

    This paper includes a conceptual framework for cell cycle modeling into which the experimenter can map observed data and evaluate mechanisms of cell cycle control. The basic model exhibits qualitative stability, meaning that regardless of magnitudes of system parameters its instances are guaranteed to be stable in the sense that all feasible trajectories converge to a certain trajectory. Qualitative stability can also be described by the signs of real parts of eigenvalues of the system matrix. On the biological side, the resulting model can be tuned to approximate experimental data pertaining to human fibroblast cell lines treated with ionizing radiation, with or without disabled DNA damage checkpoints. Together these properties validate a fundamental, first order systems view of cell dynamics. Classification Codes: 15A68.

  18. RELAP5-3D Code Includes Athena Features and Models

    Energy Technology Data Exchange (ETDEWEB)

    Richard A. Riemke; Cliff B. Davis; Richard R. Schultz

    2006-07-01

    Version 2.3 of the RELAP5-3D computer program includes all features and models previously available only in the ATHENA version of the code. These include the addition of new working fluids (i.e., ammonia, blood, carbon dioxide, glycerol, helium, hydrogen, lead-bismuth, lithium, lithium-lead, nitrogen, potassium, sodium, and sodium-potassium) and a magnetohydrodynamic model that expands the capability of the code to model many more thermal-hydraulic systems. In addition to the new working fluids along with the standard working fluid water, one or more noncondensable gases (e.g., air, argon, carbon dioxide, carbon monoxide, helium, hydrogen, krypton, nitrogen, oxygen, sf6, xenon) can be specified as part of the vapor/gas phase of the working fluid. These noncondensable gases were in previous versions of RELAP5- 3D. Recently four molten salts have been added as working fluids to RELAP5-3D Version 2.4, which has had limited release. These molten salts will be in RELAP5-3D Version 2.5, which will have a general release like RELAP5-3D Version 2.3. Applications that use these new features and models are discussed in this paper.

  19. Including policy and management in socio-hydrology models: initial conceptualizations

    Science.gov (United States)

    Hermans, Leon; Korbee, Dorien

    2017-04-01

    Socio-hydrology studies the interactions in coupled human-water systems. So far, the use of dynamic models that capture the direct feedback between societal and hydrological systems has been dominant. What has not yet been included with any particular emphasis, is the policy or management layer, which is a central element in for instance integrated water resources management (IWRM) or adaptive delta management (ADM). Studying the direct interactions between human-water systems generates knowledges that eventually helps influence these interactions in ways that may ensure better outcomes - for society and for the health and sustainability of water systems. This influence sometimes occurs through spontaneous emergence, uncoordinated by societal agents - private sector, citizens, consumers, water users. However, the term 'management' in IWRM and ADM also implies an additional coordinated attempt through various public actors. This contribution is a call to include the policy and management dimension more prominently into the research focus of the socio-hydrology field, and offers first conceptual variables that should be considered in attempts to include this policy or management layer in socio-hydrology models. This is done by drawing on existing frameworks to study policy processes throughout both planning and implementation phases. These include frameworks such as the advocacy coalition framework, collective learning and policy arrangements, which all emphasis longer-term dynamics and feedbacks between actor coalitions in strategic planning and implementation processes. A case about longter-term dynamics in the management of the Haringvliet in the Netherlands is used to illustrate the paper.

  20. EXACT SOLUTIONS FOR NONLINEAR TRANSIENT FLOW MODEL INCLUDING A QUADRATIC GRADIENT TERM

    Institute of Scientific and Technical Information of China (English)

    曹绪龙; 同登科; 王瑞和

    2004-01-01

    The models of the nonlinear radial flow for the infinite and finite reservoirs including a quadratic gradient term were presented. The exact solution was given in real space for flow equation including quadratic gradiet term for both constant-rate and constant pressure production cases in an infinite system by using generalized Weber transform. Analytical solutions for flow equation including quadratic gradient term were also obtained by using the Hankel transform for a finite circular reservoir case. Both closed and constant pressure outer boundary conditions are considered. Moreover, both constant rate and constant pressure inner boundary conditions are considered. The difference between the nonlinear pressure solution and linear pressure solution is analyzed. The difference may be reached about 8% in the long time. The effect of the quadratic gradient term in the large time well test is considered.

  1. Gastroesophageal reflux leads to esophageal cancer in a surgical model with mice

    Directory of Open Access Journals (Sweden)

    Chen Xiaoxin

    2009-07-01

    Full Text Available Abstract Background Esophago-gastroduodenal anastomosis with rats mimics the development of human Barrett's esophagus and esophageal adenocarcinoma by introducing mixed reflux of gastric and duodenal contents into the esophagus. However, use of this rat model for mechanistic and chemopreventive studies is limited due to lack of genetically modified rat strains. Therefore, a mouse model of esophageal adenocarcinoma is needed. Methods We performed reflux surgery on wild-type, p53A135V transgenic, and INK4a/Arf+/- mice of A/J strain. Some mice were also treated with omeprazole (1,400 ppm in diet, iron (50 mg/kg/m, i.p., or gastrectomy plus iron. Mouse esophagi were harvested at 20, 40 or 80 weeks after surgery for histopathological analysis. Results At week 20, we observed metaplasia in wild-type mice (5%, 1/20 and p53A135V mice (5.3%, 1/19. At week 40, metaplasia was found in wild-type mice (16.2%, 6/37, p53A135V mice (4.8%, 2/42, and wild-type mice also receiving gastrectomy and iron (6.7%, 1/15. Esophageal squamous cell carcinoma developed in INK4a/Arf+/- mice (7.1%, 1/14, and wild-type mice receiving gastrectomy and iron (21.4%, 3/14. Among 13 wild-type mice which were given iron from week 40 to 80, twelve (92.3% developed squamous cell carcinoma at week 80. None of these mice developed esophageal adenocarcinoma. Conclusion Surgically induced gastroesophageal reflux produced esophageal squamous cell carcinoma, but not esophageal adenocarcinoma, in mice. Dominant negative p53 mutation, heterozygous loss of INK4a/Arf, antacid treatment, iron supplementation, or gastrectomy failed to promote esophageal adenocarcinoma in these mice. Further studies are needed in order to develop a mouse model of esophageal adenocarcinoma.

  2. Systematic analysis of a xenograft mice model for KSHV+ primary effusion lymphoma (PEL.

    Directory of Open Access Journals (Sweden)

    Lu Dai

    Full Text Available Kaposi's sarcoma-associated herpesvirus is the causative agent of primary effusion lymphoma (PEL, which arises preferentially in the setting of infection with human immunodeficiency virus (HIV. Even with standard cytotoxic chemotherapy, PEL continues to cause high mortality rates, requiring the development of novel therapeutic strategies. PEL xenograft models employing immunodeficient mice have been used to study the in vivo effects of a variety of therapeutic approaches. However, it remains unclear whether these xenograft models entirely reflect clinical presentations of KSHV(+ PEL, especially given the recent description of extracavitary solid tumor variants arising in patients. In addition, effusion and solid tumor cells propagated in vivo exhibit unique biology, differing from one another or from their parental cell lines propagated through in vitro culture. Therefore, we used a KSHV(+ PEL/BCBL-1 xenograft model involving non-obese diabetic/severe-combined immunodeficient (NOD/SCID mice, and compared characteristics of effusion and solid tumors with their parent cell culture-derived counterparts. Our results indicate that although this xenograft model can be used for study of effusion and solid lymphoma observed in patients, tumor cells in vivo display unique features to those passed in vitro, including viral lytic gene expression profile, rate of solid tumor development, the host proteins and the complex of tumor microenvironment. These items should be carefully considered when the xenograft model is used for testing novel therapeutic strategies against KSHV-related lymphoma.

  3. Peromyscus leucopus mice: a potential animal model for haematological studies.

    Science.gov (United States)

    Sun, Yu; Desierto, Marie J; Ueda, Yasutaka; Kajigaya, Sachiko; Chen, Jichun; Young, Neal S

    2014-10-01

    Peromyscus leucopus mice share physical similarities with laboratory mice Mus musculus (MM) but have higher agility and longer lifespan. We compared domesticated P. leucopus linville (PLL) and M. musculus C57BL/6 (MMB6) mice for cellular composition of peripheral blood (PB), bone marrow (BM) and spleen. PLL mice had significantly fewer platelets and significantly more monocytes in the blood, and notably fewer megakaryocytes in the BM. Spleens of PLL mice were significantly smaller, with 50% fewer cells and reduced 'red pulp'. There was no obvious haematological change in PLL mice between 2-8 and 16-26 months of age, except for a significant increase in blood monocytes. Cellular reactive oxygen species (ROS) content showed no change with age but differed significantly between different cell types. Treating two to eight month-old PLL mice with antioxidant N-acetylcysteine in drinking water for three months did not affect cellular ROS content, but increased blood leucocytes especially the concentration of monocytes. The low platelets, low megakaryocytes, high monocytes and low splenic erythropoiesis in PLL mice resemble human measurements better than the values seen in MMB6.

  4. SPheno 3.1: extensions including flavour, CP-phases and models beyond the MSSM

    Science.gov (United States)

    Porod, W.; Staub, F.

    2012-11-01

    We describe recent extensions of the program SPhenoincluding flavour aspects, CP-phases, R-parity violation and low energy observables. In case of flavour mixing all masses of supersymmetric particles are calculated including the complete flavour structure and all possible CP-phases at the 1-loop level. We give details on implemented seesaw models, low energy observables and the corresponding extension of the SUSY Les Houches Accord. Moreover, we comment on the possibilities to include MSSM extensions in SPheno. Catalogue identifier: ADRV_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADRV_v2_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 154062 No. of bytes in distributed program, including test data, etc.: 1336037 Distribution format: tar.gz Programming language: Fortran95. Computer: PC running under Linux, should run in every Unix environment. Operating system: Linux, Unix. Classification: 11.6. Catalogue identifier of previous version: ADRV_v1_0 Journal reference of previous version: Comput. Phys. Comm. 153(2003)275 Does the new version supersede the previous version?: Yes Nature of problem: The first issue is the determination of the masses and couplings of supersymmetric particles in various supersymmetric models, the R-parity conserved MSSM with generation mixing and including CP-violating phases, various seesaw extensions of the MSSM and the MSSM with bilinear R-parity breaking. Low energy data on Standard Model fermion masses, gauge couplings and electroweak gauge boson masses serve as constraints. Radiative corrections from supersymmetric particles to these inputs must be calculated. Theoretical constraints on the soft SUSY breaking parameters from a high scale theory are imposed and the parameters at the electroweak scale are obtained from the

  5. DISPLAY-2: a two-dimensional shallow layer model for dense gas dispersion including complex features.

    Science.gov (United States)

    Venetsanos, A G; Bartzis, J G; Würtz, J; Papailiou, D D

    2003-04-25

    A two-dimensional shallow layer model has been developed to predict dense gas dispersion, under realistic conditions, including complex features such as two-phase releases, obstacles and inclined ground. The model attempts to predict the time and space evolution of the cloud formed after a release of a two-phase pollutant into the atmosphere. The air-pollutant mixture is assumed ideal. The cloud evolution is described mathematically through the Cartesian, two-dimensional, shallow layer conservation equations for mixture mass, mixture momentum in two horizontal directions, total pollutant mass fraction (vapor and liquid) and mixture internal energy. Liquid mass fraction is obtained assuming phase equilibrium. Account is taken in the conservation equations for liquid slip and eventual liquid rainout through the ground. Entrainment of ambient air is modeled via an entrainment velocity model, which takes into account the effects of ground friction, ground heat transfer and relative motion between cloud and surrounding atmosphere. The model additionally accounts for thin obstacles effects in three ways. First a stepwise description of the obstacle is generated, following the grid cell faces, taking into account the corresponding area blockage. Then obstacle drag on the passing cloud is modeled by adding flow resistance terms in the momentum equations. Finally the effect of extra vorticity generation and entrainment enhancement behind obstacles is modeled by adding locally into the entrainment formula without obstacles, a characteristic velocity scale defined from the obstacle pressure drop and the local cloud height.The present model predictions have been compared against theoretical results for constant volume and constant flux gravity currents. It was found that deviations of the predicted cloud footprint area change with time from the theoretical were acceptably small, if one models the frictional forces between cloud and ambient air, neglecting the Richardson

  6. Sensitivity of an atmospheric photochemistry model to chlorine perturbations including consideration of uncertainty propagation

    Science.gov (United States)

    Stolarski, R. S.; Douglass, A. R.

    1986-01-01

    Models of stratospheric photochemistry are generally tested by comparing their predictions for the composition of the present atmosphere with measurements of species concentrations. These models are then used to make predictions of the atmospheric sensitivity to perturbations. Here the problem of the sensitivity of such a model to chlorine perturbations ranging from the present influx of chlorine-containing compounds to several times that influx is addressed. The effects of uncertainties in input parameters, including reaction rate coefficients, cross sections, solar fluxes, and boundary conditions, are evaluated using a Monte Carlo method in which the values of the input parameters are randomly selected. The results are probability distributions for present atmosheric concentrations and for calculated perturbations due to chlorine from fluorocarbons. For more than 300 Monte Carlo runs the calculated ozone perturbation for continued emission of fluorocarbons at today's rates had a mean value of -6.2 percent, with a 1-sigma width of 5.5 percent. Using the same runs but only allowing the cases in which the calculated present atmosphere values of NO, NO2, and ClO at 25 km altitude fell within the range of measurements yielded a mean ozone depletion of -3 percent, with a 1-sigma deviation of 2.2 percent. The model showed a nonlinear behavior as a function of added fluorocarbons. The mean of the Monte Carlo runs was less nonlinear than the model run using mean value of the input parameters.

  7. Health Promotion Behavior of Chinese International Students in Korea Including Acculturation Factors: A Structural Equation Model.

    Science.gov (United States)

    Kim, Sun Jung; Yoo, Il Young

    2016-03-01

    The purpose of this study was to explain the health promotion behavior of Chinese international students in Korea using a structural equation model including acculturation factors. A survey using self-administered questionnaires was employed. Data were collected from 272 Chinese students who have resided in Korea for longer than 6 months. The data were analyzed using structural equation modeling. The p value of final model is .31. The fitness parameters of the final model such as goodness of fit index, adjusted goodness of fit index, normed fit index, non-normed fit index, and comparative fit index were more than .95. Root mean square of residual and root mean square error of approximation also met the criteria. Self-esteem, perceived health status, acculturative stress and acculturation level had direct effects on health promotion behavior of the participants and the model explained 30.0% of variance. The Chinese students in Korea with higher self-esteem, perceived health status, acculturation level, and lower acculturative stress reported higher health promotion behavior. The findings can be applied to develop health promotion strategies for this population. Copyright © 2016. Published by Elsevier B.V.

  8. S5-4: Formal Modeling of Affordance in Human-Included Systems

    Directory of Open Access Journals (Sweden)

    Namhun Kim

    2012-10-01

    Full Text Available In spite of it being necessary for humans to consider modeling, analysis, and control of human-included systems, it has been considered a challenging problem because of the critical role of humans in complex systems and of humans' capability of executing unanticipated actions–both beneficial and detrimental ones. Thus, to provide systematic approaches to modeling human actions as a part of system behaviors, a formal modeling framework for human-involved systems in which humans play a controlling role based on their perceptual information is presented. The theory of affordance provides definitions of human actions and their associated properties; Finite State Automata (FSA based modeling is capable of mapping nondeterministic humans into computable components in the system representation. In this talk, we investigate the role of perception in human actions in the system operation and examine the representation of perceptual elements in affordance-based modeling formalism. The proposed framework is expected to capture the natural ways in which humans participate in the system as part of its operation. A human-machine cooperative manufacturing system control example and a human agent simulation example will be introduced for the illustrative purposes at the end of the presentation.

  9. An extended gene protein/products Boolean network model including post-transcriptional regulation.

    Science.gov (United States)

    Benso, Alfredo; Di Carlo, Stefano; Politano, Gianfranco; Savino, Alessandro; Vasciaveo, Alessandro

    2014-05-07

    Networks Biology allows the study of complex interactions between biological systems using formal, well structured, and computationally friendly models. Several different network models can be created, depending on the type of interactions that need to be investigated. Gene Regulatory Networks (GRN) are an effective model commonly used to study the complex regulatory mechanisms of a cell. Unfortunately, given their intrinsic complexity and non discrete nature, the computational study of realistic-sized complex GRNs requires some abstractions. Boolean Networks (BNs), for example, are a reliable model that can be used to represent networks where the possible state of a node is a boolean value (0 or 1). Despite this strong simplification, BNs have been used to study both structural and dynamic properties of real as well as randomly generated GRNs. In this paper we show how it is possible to include the post-transcriptional regulation mechanism (a key process mediated by small non-coding RNA molecules like the miRNAs) into the BN model of a GRN. The enhanced BN model is implemented in a software toolkit (EBNT) that allows to analyze boolean GRNs from both a structural and a dynamic point of view. The open-source toolkit is compatible with available visualization tools like Cytoscape and allows to run detailed analysis of the network topology as well as of its attractors, trajectories, and state-space. In the paper, a small GRN built around the mTOR gene is used to demonstrate the main capabilities of the toolkit. The extended model proposed in this paper opens new opportunities in the study of gene regulation. Several of the successful researches done with the support of BN to understand high-level characteristics of regulatory networks, can now be improved to better understand the role of post-transcriptional regulation for example as a network-wide noise-reduction or stabilization mechanisms.

  10. An extended gene protein/products boolean network model including post-transcriptional regulation

    Science.gov (United States)

    2014-01-01

    Background Networks Biology allows the study of complex interactions between biological systems using formal, well structured, and computationally friendly models. Several different network models can be created, depending on the type of interactions that need to be investigated. Gene Regulatory Networks (GRN) are an effective model commonly used to study the complex regulatory mechanisms of a cell. Unfortunately, given their intrinsic complexity and non discrete nature, the computational study of realistic-sized complex GRNs requires some abstractions. Boolean Networks (BNs), for example, are a reliable model that can be used to represent networks where the possible state of a node is a boolean value (0 or 1). Despite this strong simplification, BNs have been used to study both structural and dynamic properties of real as well as randomly generated GRNs. Results In this paper we show how it is possible to include the post-transcriptional regulation mechanism (a key process mediated by small non-coding RNA molecules like the miRNAs) into the BN model of a GRN. The enhanced BN model is implemented in a software toolkit (EBNT) that allows to analyze boolean GRNs from both a structural and a dynamic point of view. The open-source toolkit is compatible with available visualization tools like Cytoscape and allows to run detailed analysis of the network topology as well as of its attractors, trajectories, and state-space. In the paper, a small GRN built around the mTOR gene is used to demonstrate the main capabilities of the toolkit. Conclusions The extended model proposed in this paper opens new opportunities in the study of gene regulation. Several of the successful researches done with the support of BN to understand high-level characteristics of regulatory networks, can now be improved to better understand the role of post-transcriptional regulation for example as a network-wide noise-reduction or stabilization mechanisms. PMID:25080304

  11. General hypothesis and shell model for the synthesis of semiconductor nanotubes, including carbon nanotubes

    Science.gov (United States)

    Mohammad, S. Noor

    2010-09-01

    Semiconductor nanotubes, including carbon nanotubes, have vast potential for new technology development. The fundamental physics and growth kinetics of these nanotubes are still obscured. Various models developed to elucidate the growth suffer from limited applicability. An in-depth investigation of the fundamentals of nanotube growth has, therefore, been carried out. For this investigation, various features of nanotube growth, and the role of the foreign element catalytic agent (FECA) in this growth, have been considered. Observed growth anomalies have been analyzed. Based on this analysis, a new shell model and a general hypothesis have been proposed for the growth. The essential element of the shell model is the seed generated from segregation during growth. The seed structure has been defined, and the formation of droplet from this seed has been described. A modified definition of the droplet exhibiting adhesive properties has also been presented. Various characteristics of the droplet, required for alignment and organization of atoms into tubular forms, have been discussed. Employing the shell model, plausible scenarios for the formation of carbon nanotubes, and the variation in the characteristics of these carbon nanotubes have been articulated. The experimental evidences, for example, for the formation of shell around a core, dipole characteristics of the seed, and the existence of nanopores in the seed, have been presented. They appear to justify the validity of the proposed model. The diversities of nanotube characteristics, fundamentals underlying the creation of bamboo-shaped carbon nanotubes, and the impurity generation on the surface of carbon nanotubes have been elucidated. The catalytic action of FECA on growth has been quantified. The applicability of the proposed model to the nanotube growth by a variety of mechanisms has been elaborated. These mechanisms include the vapor-liquid-solid mechanism, the oxide-assisted growth mechanism, the self

  12. Mutant Enpp1asj mice as a model for generalized arterial calcification of infancy

    Directory of Open Access Journals (Sweden)

    Qiaoli Li

    2013-09-01

    Generalized arterial calcification of infancy (GACI, an autosomal recessive disorder, is characterized by early mineralization of blood vessels, often diagnosed by prenatal ultrasound and usually resulting in demise during the first year of life. It is caused in most cases by mutations in the ENPP1 gene, encoding an enzyme that hydrolyzes ATP to AMP and inorganic pyrophosphate, the latter being a powerful anti-mineralization factor. Recently, a novel mouse phenotype was recognized as a result of ENU mutagenesis – those mice developed stiffening of the joints, hence the mutant mouse was named ‘ages with stiffened joints’ (asj. These mice harbor a missense mutation, p.V246D, in the Enpp1 gene. Here we demonstrate that the mutant ENPP1 protein is largely absent in the liver of asj mice, and the lack of enzymatic activity results in reduced inorganic pyrophosphate (PPi levels in the plasma, accompanied by extensive mineralization of a number of tissues, including arterial blood vessels. The progress of mineralization is highly dependent on the mineral composition of the diet, with significant shortening of the lifespan on a diet enriched in phosphorus and low in magnesium. These results suggest that the asj mouse can serve as an animal model for GACI.

  13. Mutant Enpp1asj mice as a model for generalized arterial calcification of infancy.

    Science.gov (United States)

    Li, Qiaoli; Guo, Haitao; Chou, David W; Berndt, Annerose; Sundberg, John P; Uitto, Jouni

    2013-09-01

    Generalized arterial calcification of infancy (GACI), an autosomal recessive disorder, is characterized by early mineralization of blood vessels, often diagnosed by prenatal ultrasound and usually resulting in demise during the first year of life. It is caused in most cases by mutations in the ENPP1 gene, encoding an enzyme that hydrolyzes ATP to AMP and inorganic pyrophosphate, the latter being a powerful anti-mineralization factor. Recently, a novel mouse phenotype was recognized as a result of ENU mutagenesis - those mice developed stiffening of the joints, hence the mutant mouse was named 'ages with stiffened joints' (asj). These mice harbor a missense mutation, p.V246D, in the Enpp1 gene. Here we demonstrate that the mutant ENPP1 protein is largely absent in the liver of asj mice, and the lack of enzymatic activity results in reduced inorganic pyrophosphate (PPi) levels in the plasma, accompanied by extensive mineralization of a number of tissues, including arterial blood vessels. The progress of mineralization is highly dependent on the mineral composition of the diet, with significant shortening of the lifespan on a diet enriched in phosphorus and low in magnesium. These results suggest that the asj mouse can serve as an animal model for GACI.

  14. Comparison of random forest and parametric imputation models for imputing missing data using MICE: a CALIBER study.

    Science.gov (United States)

    Shah, Anoop D; Bartlett, Jonathan W; Carpenter, James; Nicholas, Owen; Hemingway, Harry

    2014-03-15

    Multivariate imputation by chained equations (MICE) is commonly used for imputing missing data in epidemiologic research. The "true" imputation model may contain nonlinearities which are not included in default imputation models. Random forest imputation is a machine learning technique which can accommodate nonlinearities and interactions and does not require a particular regression model to be specified. We compared parametric MICE with a random forest-based MICE algorithm in 2 simulation studies. The first study used 1,000 random samples of 2,000 persons drawn from the 10,128 stable angina patients in the CALIBER database (Cardiovascular Disease Research using Linked Bespoke Studies and Electronic Records; 2001-2010) with complete data on all covariates. Variables were artificially made "missing at random," and the bias and efficiency of parameter estimates obtained using different imputation methods were compared. Both MICE methods produced unbiased estimates of (log) hazard ratios, but random forest was more efficient and produced narrower confidence intervals. The second study used simulated data in which the partially observed variable depended on the fully observed variables in a nonlinear way. Parameter estimates were less biased using random forest MICE, and confidence interval coverage was better. This suggests that random forest imputation may be useful for imputing complex epidemiologic data sets in which some patients have missing data.

  15. Analysis of electronic models for solar cells including energy resolved defect densities

    Energy Technology Data Exchange (ETDEWEB)

    Glitzky, Annegret

    2010-07-01

    We introduce an electronic model for solar cells including energy resolved defect densities. The resulting drift-diffusion model corresponds to a generalized van Roosbroeck system with additional source terms coupled with ODEs containing space and energy as parameters for all defect densities. The system has to be considered in heterostructures and with mixed boundary conditions from device simulation. We give a weak formulation of the problem. If the boundary data and the sources are compatible with thermodynamic equilibrium the free energy along solutions decays monotonously. In other cases it may be increasing, but we estimate its growth. We establish boundedness and uniqueness results and prove the existence of a weak solution. This is done by considering a regularized problem, showing its solvability and the boundedness of its solutions independent of the regularization level. (orig.)

  16. Nonlinear Acoustics FDTD method including Frequency Power Law Attenuation for Soft Tissue Modeling

    CERN Document Server

    Jiménez, Noé; Sánchez-Morcillo, Víctor; Camarena, Francisco; Hou, Yi; Konofagou, Elisa E

    2014-01-01

    This paper describes a model for nonlinear acoustic wave propagation through absorbing and weakly dispersive media, and its numerical solution by means of finite differences in time domain method (FDTD). The attenuation is based on multiple relaxation processes, and provides frequency dependent absorption and dispersion without using computational expensive convolutional operators. In this way, by using an optimization algorithm the coefficients for the relaxation processes can be obtained in order to fit a frequency power law that agrees the experimentally measured attenuation data for heterogeneous media over the typical frequency range for ultrasound medical applications. Our results show that two relaxation processes are enough to fit attenuation data for most soft tissues in this frequency range including the fundamental and the first ten harmonics. Furthermore, this model can fit experimental attenuation data that do not follow exactly a frequency power law over the frequency range of interest. The main...

  17. Particle-based modeling of heterogeneous chemical kinetics including mass transfer

    Science.gov (United States)

    Sengar, A.; Kuipers, J. A. M.; van Santen, Rutger A.; Padding, J. T.

    2017-08-01

    Connecting the macroscopic world of continuous fields to the microscopic world of discrete molecular events is important for understanding several phenomena occurring at physical boundaries of systems. An important example is heterogeneous catalysis, where reactions take place at active surfaces, but the effective reaction rates are determined by transport limitations in the bulk fluid and reaction limitations on the catalyst surface. In this work we study the macro-micro connection in a model heterogeneous catalytic reactor by means of stochastic rotation dynamics. The model is able to resolve the convective and diffusive interplay between participating species, while including adsorption, desorption, and reaction processes on the catalytic surface. Here we apply the simulation methodology to a simple straight microchannel with a catalytic strip. Dimensionless Damkohler numbers are used to comment on the spatial concentration profiles of reactants and products near the catalyst strip and in the bulk. We end the discussion with an outlook on more complicated geometries and increasingly complex reactions.

  18. Models of epidemics: when contact repetition and clustering should be included

    Directory of Open Access Journals (Sweden)

    Scholz Roland W

    2009-06-01

    Full Text Available Abstract Background The spread of infectious disease is determined by biological factors, e.g. the duration of the infectious period, and social factors, e.g. the arrangement of potentially contagious contacts. Repetitiveness and clustering of contacts are known to be relevant factors influencing the transmission of droplet or contact transmitted diseases. However, we do not yet completely know under what conditions repetitiveness and clustering should be included for realistically modelling disease spread. Methods We compare two different types of individual-based models: One assumes random mixing without repetition of contacts, whereas the other assumes that the same contacts repeat day-by-day. The latter exists in two variants, with and without clustering. We systematically test and compare how the total size of an outbreak differs between these model types depending on the key parameters transmission probability, number of contacts per day, duration of the infectious period, different levels of clustering and varying proportions of repetitive contacts. Results The simulation runs under different parameter constellations provide the following results: The difference between both model types is highest for low numbers of contacts per day and low transmission probabilities. The number of contacts and the transmission probability have a higher influence on this difference than the duration of the infectious period. Even when only minor parts of the daily contacts are repetitive and clustered can there be relevant differences compared to a purely random mixing model. Conclusion We show that random mixing models provide acceptable estimates of the total outbreak size if the number of contacts per day is high or if the per-contact transmission probability is high, as seen in typical childhood diseases such as measles. In the case of very short infectious periods, for instance, as in Norovirus, models assuming repeating contacts will also behave

  19. Standardized Competencies for Parenteral Nutrition Order Review and Parenteral Nutrition Preparation, Including Compounding: The ASPEN Model.

    Science.gov (United States)

    Boullata, Joseph I; Holcombe, Beverly; Sacks, Gordon; Gervasio, Jane; Adams, Stephen C; Christensen, Michael; Durfee, Sharon; Ayers, Phil; Marshall, Neil; Guenter, Peggi

    2016-08-01

    Parenteral nutrition (PN) is a high-alert medication with a complex drug use process. Key steps in the process include the review of each PN prescription followed by the preparation of the formulation. The preparation step includes compounding the PN or activating a standardized commercially available PN product. The verification and review, as well as preparation of this complex therapy, require competency that may be determined by using a standardized process for pharmacists and for pharmacy technicians involved with PN. An American Society for Parenteral and Enteral Nutrition (ASPEN) standardized model for PN order review and PN preparation competencies is proposed based on a competency framework, the ASPEN-published interdisciplinary core competencies, safe practice recommendations, and clinical guidelines, and is intended for institutions and agencies to use with their staff.

  20. A generalized model for optimal transport of images including dissipation and density modulation

    KAUST Repository

    Maas, Jan

    2015-11-01

    © EDP Sciences, SMAI 2015. In this paper the optimal transport and the metamorphosis perspectives are combined. For a pair of given input images geodesic paths in the space of images are defined as minimizers of a resulting path energy. To this end, the underlying Riemannian metric measures the rate of transport cost and the rate of viscous dissipation. Furthermore, the model is capable to deal with strongly varying image contrast and explicitly allows for sources and sinks in the transport equations which are incorporated in the metric related to the metamorphosis approach by Trouvé and Younes. In the non-viscous case with source term existence of geodesic paths is proven in the space of measures. The proposed model is explored on the range from merely optimal transport to strongly dissipative dynamics. For this model a robust and effective variational time discretization of geodesic paths is proposed. This requires to minimize a discrete path energy consisting of a sum of consecutive image matching functionals. These functionals are defined on corresponding pairs of intensity functions and on associated pairwise matching deformations. Existence of time discrete geodesics is demonstrated. Furthermore, a finite element implementation is proposed and applied to instructive test cases and to real images. In the non-viscous case this is compared to the algorithm proposed by Benamou and Brenier including a discretization of the source term. Finally, the model is generalized to define discrete weighted barycentres with applications to textures and objects.

  1. Fluid-structure interaction including volumetric coupling with homogenised subdomains for modeling respiratory mechanics.

    Science.gov (United States)

    Yoshihara, Lena; Roth, Christian J; Wall, Wolfgang A

    2017-04-01

    In this article, a novel approach is presented for combining standard fluid-structure interaction with additional volumetric constraints to model fluid flow into and from homogenised solid domains. The proposed algorithm is particularly interesting for investigations in the field of respiratory mechanics as it enables the mutual coupling of airflow in the conducting part and local tissue deformation in the respiratory part of the lung by means of a volume constraint. In combination with a classical monolithic fluid-structure interaction approach, a comprehensive model of the human lung can be established that will be useful to gain new insights into respiratory mechanics in health and disease. To illustrate the validity and versatility of the novel approach, three numerical examples including a patient-specific lung model are presented. The proposed algorithm proves its capability of computing clinically relevant airflow distribution and tissue strain data at a level of detail that is not yet achievable, neither with current imaging techniques nor with existing computational models. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Empirical Validation of a Thermal Model of a Complex Roof Including Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Stéphane Guichard

    2015-12-01

    Full Text Available This paper deals with the empirical validation of a building thermal model of a complex roof including a phase change material (PCM. A mathematical model dedicated to PCMs based on the heat apparent capacity method was implemented in a multi-zone building simulation code, the aim being to increase the understanding of the thermal behavior of the whole building with PCM technologies. In order to empirically validate the model, the methodology is based both on numerical and experimental studies. A parametric sensitivity analysis was performed and a set of parameters of the thermal model has been identified for optimization. The use of the generic optimization program called GenOpt® coupled to the building simulation code enabled to determine the set of adequate parameters. We first present the empirical validation methodology and main results of previous work. We then give an overview of GenOpt® and its coupling with the building simulation code. Finally, once the optimization results are obtained, comparisons of the thermal predictions with measurements are found to be acceptable and are presented.

  3. Habitability of super-Earth planets around other suns: models including Red Giant Branch evolution.

    Science.gov (United States)

    von Bloh, W; Cuntz, M; Schröder, K-P; Bounama, C; Franck, S

    2009-01-01

    The unexpected diversity of exoplanets includes a growing number of super-Earth planets, i.e., exoplanets with masses of up to several Earth masses and a similar chemical and mineralogical composition as Earth. We present a thermal evolution model for a 10 Earth-mass planet orbiting a star like the Sun. Our model is based on the integrated system approach, which describes the photosynthetic biomass production and takes into account a variety of climatological, biogeochemical, and geodynamical processes. This allows us to identify a so-called photosynthesis-sustaining habitable zone (pHZ), as determined by the limits of biological productivity on the planetary surface. Our model considers solar evolution during the main-sequence stage and along the Red Giant Branch as described by the most recent solar model. We obtain a large set of solutions consistent with the principal possibility of life. The highest likelihood of habitability is found for "water worlds." Only mass-rich water worlds are able to realize pHZ-type habitability beyond the stellar main sequence on the Red Giant Branch.

  4. Mice lacking caspase-2 are protected from behavioral changes, but not pathology, in the YAC128 model of Huntington disease

    Directory of Open Access Journals (Sweden)

    Bissada Nagat

    2011-08-01

    Full Text Available Abstract Background Huntington Disease (HD is a neurodegenerative disorder in which caspase activation and cleavage of substrates, including the huntingtin protein, has been invoked as a pathological mechanism. Specific changes in caspase-2 (casp2 activity have been suggested to contribute to the pathogenesis of HD, however unique casp2 cleavage substrates have remained elusive. We thus utilized mice completely lacking casp2 (casp2-/- to examine the role played by casp2 in the progression of HD. This 'substrate agnostic' approach allows us to query the effect of casp2 on HD progression without pre-defining proteolytic substrates of interest. Results YAC128 HD model mice lacking casp2 show protection from well-validated motor and cognitive features of HD, including performance on rotarod, swimming T-maze, pre-pulse inhibition, spontaneous alternation and locomotor tasks. However, the specific pathological features of the YAC128 mice including striatal volume loss and testicular degeneration are unaltered in mice lacking casp2. The application of high-resolution magnetic resonance imaging (MRI techniques validates specific neuropathology in the YAC128 mice that is not altered by ablation of casp2. Conclusions The rescue of behavioral phenotypes in the absence of pathological improvement suggests that different pathways may be operative in the dysfunction of neural circuitry in HD leading to behavioral changes compared to the processes leading to cell death and volume loss. Inhibition of caspase-2 activity may be associated with symptomatic improvement in HD.

  5. A transient energy function for power systems including the induction motor model

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A construction method for power system transient energy function is studied in the paper, which is simple and universal, and can unify the forms of some current energy functions. A transient energy function including the induction motor model is derived using the method. The unintegrable term is dealt with to get an approximate energy function. Simulations in a 3-bus system and in the WSCC 4-generator system verify the validity of the proposed energy function. The function can be applied to direct transient stability analysis of multi-machine large power systems and provides a tool for analysis of the interaction between the generator angle stability and the load voltage stability.

  6. A laboratory model of the aortic root flow including the coronary arteries

    Science.gov (United States)

    Querzoli, Giorgio; Fortini, Stefania; Espa, Stefania; Melchionna, Simone

    2016-08-01

    Cardiovascular flows have been extensively investigated by means of in vitro models to assess the prosthetic valve performances and to provide insight into the fluid dynamics of the heart and proximal aorta. In particular, the models for the study of the flow past the aortic valve have been continuously improved by including, among other things, the compliance of the vessel and more realistic geometries. The flow within the sinuses of Valsalva is known to play a fundamental role in the dynamics of the aortic valve since they host a recirculation region that interacts with the leaflets. The coronary arteries originate from the ostia located within two of the three sinuses, and their presence may significantly affect the fluid dynamics of the aortic root. In spite of their importance, to the extent of the authors' knowledge, coronary arteries were not included so far when modeling in vitro the transvalvular aortic flow. We present a pulse duplicator consisting of a passively pulsing ventricle, a compliant proximal aorta, and coronary arteries connected to the sinuses of Valsalva. The coronary flow is modulated by a self-regulating device mimicking the physiological mechanism, which is based on the contraction and relaxation of the heart muscle during the cardiac cycle. Results show that the model reproduces satisfyingly the coronary flow. The analysis of the time evolution of the velocity and vorticity fields within the aortic root reveals the main characteristics of the backflow generated through the aorta in order to feed the coronaries during the diastole. Experiments without coronary flow have been run for comparison. Interestingly, the lifetime of the vortex forming in the sinus of Valsalva during the systole is reduced by the presence of the coronaries. As a matter of fact, at the end of the systole, that vortex is washed out because of the suction generated by the coronary flow. Correspondingly, the valve closure is delayed and faster compared to the case with

  7. Including sugar cane in the agro-ecosystem model ORCHIDEE-STICS

    Science.gov (United States)

    Valade, A.; Vuichard, N.; Ciais, P.; Viovy, N.

    2010-12-01

    With 4 million ha currently grown for ethanol in Brazil only, approximately half the global bioethanol production in 2005 (Smeets 2008), and a devoted land area expected to expand globally in the years to come, sugar cane is at the heart of the biofuel debate. Indeed, ethanol made from biomass is currently the most widespread option for alternative transportation fuels. It was originally promoted as a carbon neutral energy resource that could bring energy independence to countries and local opportunities to farmers, until attention was drawn to its environmental and socio-economical drawbacks. It is still not clear to which extent it is a solution or a contributor to climate change mitigation. Dynamic Global Vegetation models can help address these issues and quantify the potential impacts of biofuels on ecosystems at scales ranging from on-site to global. The global agro-ecosystem model ORCHIDEE describes water, carbon and energy exchanges at the soil-atmosphere interface for a limited number of natural and agricultural vegetation types. In order to integrate agricultural management to the simulations and to capture more accurately the specificity of crops' phenology, ORCHIDEE has been coupled with the agronomical model STICS. The resulting crop-oriented vegetation model ORCHIDEE-STICS has been used so far to simulate temperate crops such as wheat, corn and soybean. As a generic ecosystem model, each grid cell can include several vegetation types with their own phenology and management practices, making it suitable to spatial simulations. Here, ORCHIDEE-STICS is altered to include sugar cane as a new agricultural Plant functional Type, implemented and parametrized using the STICS approach. An on-site calibration and validation is then performed based on biomass and flux chamber measurements in several sites in Australia and variables such as LAI, dry weight, heat fluxes and respiration are used to evaluate the ability of the model to simulate the specific

  8. Ectopic Mineralization and Conductive Hearing Loss in Enpp1asj Mutant Mice, a New Model for Otitis Media and Tympanosclerosis.

    Science.gov (United States)

    Tian, Cong; Harris, Belinda S; Johnson, Kenneth R

    2016-01-01

    Otitis media (OM), inflammation of the middle ear, is a common cause of hearing loss in children and in patients with many different syndromic diseases. Studies of the human population and mouse models have revealed that OM is a multifactorial disease with many environmental and genetic contributing factors. Here, we report on otitis media-related hearing loss in asj (ages with stiffened joints) mutant mice, which bear a point mutation in the Enpp1 gene. Auditory-evoked brainstem response (ABR) measurements revealed that around 90% of the mutant mice (Enpp1asj/asj) tested had moderate to severe hearing impairment in at least one ear. The ABR thresholds were variable and generally elevated with age. We found otitis media with effusion (OME) in all of the hearing-impaired Enpp1asj/asj mice by anatomic and histological examinations. The volume and inflammatory cell content of the effusion varied among the asj mutant mice, but all mutants exhibited a thickened middle ear epithelium with fibrous polyps and more mucin-secreting goblet cells than controls. Other abnormalities observed in the Enpp1 mutant mice include over-ossification at the round window ridge, thickened and over-calcified stapedial artery, fusion of malleus and incus, and white patches on the inside of tympanic membrane, some of which are typical symptoms of tympanosclerosis. An excessive yellow discharge was detected in the outer ear canal of older asj mutant mice, with 100% penetrance by 5 months of age, and contributes to the progressive nature of the hearing loss. This is the first report of hearing loss and ear pathology associated with an Enpp1 mutation in mice. The Enpp1asj mutant mouse provides a new animal model for studying tympanosclerotic otitis and otitis media with effusion, and also provides a specific model for the hearing loss recently reported to be associated with human ENPP1 mutations causing generalized arterial calcification of infancy and hypophosphatemic rickets.

  9. A range of complex probabilistic models for RNA secondary structure prediction that includes the nearest-neighbor model and more.

    Science.gov (United States)

    Rivas, Elena; Lang, Raymond; Eddy, Sean R

    2012-02-01

    The standard approach for single-sequence RNA secondary structure prediction uses a nearest-neighbor thermodynamic model with several thousand experimentally determined energy parameters. An attractive alternative is to use statistical approaches with parameters estimated from growing databases of structural RNAs. Good results have been reported for discriminative statistical methods using complex nearest-neighbor models, including CONTRAfold, Simfold, and ContextFold. Little work has been reported on generative probabilistic models (stochastic context-free grammars [SCFGs]) of comparable complexity, although probabilistic models are generally easier to train and to use. To explore a range of probabilistic models of increasing complexity, and to directly compare probabilistic, thermodynamic, and discriminative approaches, we created TORNADO, a computational tool that can parse a wide spectrum of RNA grammar architectures (including the standard nearest-neighbor model and more) using a generalized super-grammar that can be parameterized with probabilities, energies, or arbitrary scores. By using TORNADO, we find that probabilistic nearest-neighbor models perform comparably to (but not significantly better than) discriminative methods. We find that complex statistical models are prone to overfitting RNA structure and that evaluations should use structurally nonhomologous training and test data sets. Overfitting has affected at least one published method (ContextFold). The most important barrier to improving statistical approaches for RNA secondary structure prediction is the lack of diversity of well-curated single-sequence RNA secondary structures in current RNA databases.

  10. Can outbred mice be used as a mouse model of mild cognitive impairment?

    Institute of Scientific and Technical Information of China (English)

    Fang Wang; Wenhua Xu; Chao Wang; Dewu Huang; Guihai Chen

    2010-01-01

    Deficits in spatial learning and memory are some of the earliest symptoms in mild cognitive impairment (MCI). However, there are few valid MCI animal models available to evaluate putative therapeutic strategies. The aim of this study was to obtain a natural animal model of MCI. Outbred Kunming (aged 5 and 12.5 months) and ICR (7 and 12 months) mice were utilized in the present study. Morris water maze and radial six-arm water maze (RAWM) were simultaneously used to evaluate impaired spatial learning and memory in middle-aged mice (approximately 12 months of age). Compared with younger mice in the respective groups, the middle-aged mice suffered visible impairment of spatial memory in the Morris water maze and RAWM, and mild spatial learning deficiency occurred in the RAWM study alone. Thus outbred Kunming and ICR mice could be utilized as a natural animal model for MCI, in particular for memory impairment studies.

  11. a New Model for Describing Evolution and Control of Disaster System Including Instantaneous and Continuous Actions

    Science.gov (United States)

    Chen, Chang-Kun; Li, Zhi; Sun, Yun-Feng

    A new model for describing the disaster system including instantaneous and continuous action synchronously has been developed. The model is composed of three primary parts, that is, the impact from its causative disaster events, stochastic noise of disaster node and self-healing function, and every part is modeled concretely in terms of their characteristics in practice. Some key parameters, namely link appearance probability, retardation coefficient, ultimate repair capacity of government, dynamical modes considering different disaster evolving chains, and the positions of link with the specific performance in disaster network system are involved. Combined with a case study, the proposed model is applied to a certain disaster evolution system, and the influence law of different parameters on disaster evolution process, in disaster networks with instantaneous-action and/or continuous-action, is presented and compared. The results indicate that the destructive impact in the networks by link in continuous action is far greater an order of magnitude than that in instantaneous action. If a link in continuous action emerges in the disaster network system, properties of the causative event for the link, link appearance probability and its position in the network all have a notable influence to the severity of the disaster network. In addition, some peculiar phenomena are also commendably observed in the disaster evolution process based on the model, such as the multipeaks emerging in the destroyed rate number curve for some crisis nodes caused by their various inducing paths together with the relevant retardation coefficients, the existence of the critical value for ultimate repair capacity to recover the disaster node, and so on.

  12. A model predicting fluindione dose requirement in elderly inpatients including genotypes, body weight, and amiodarone.

    Science.gov (United States)

    Moreau, Caroline; Pautas, Eric; Duverlie, Charlotte; Berndt, Celia; Andro, Marion; Mahé, Isabelle; Emmerich, Joseph; Lacut, Karine; Le Gal, Grégoire; Peyron, Isabelle; Gouin-Thibault, Isabelle; Golmard, Jean-Louis; Loriot, Marie-Anne; Siguret, Virginie

    2014-04-01

    Indandione VKAs have been widely used for decades, especially in Eastern Europe and France. Contrary to coumarin VKAs, the relative contribution of individual factors to the indandione-VKA response is poorly known. In the present multicentre study, we sought to develop and validate a model including genetic and non-genetic factors to predict the daily fluindione dose requirement in elderly patients in whom VKA dosing is challenging. We prospectively recorded clinical and therapeutic data in 230 Caucasian inpatients mean aged 85 ± 6 years, who had reached international normalized ratio stabilisation (range 2.0-3.0) on fluindione. In the derivation cohort (n=156), we analysed 13 polymorphisms in seven genes potentially involved in the pharmacological effect or vitamin-K cycle (VKORC1, CYP4F2, EPHX1) and fluindione metabolism/transport (CYP2C9, CYP2C19, CYP3A5, ABCB1). We built a regression model incorporating non-genetic and genetic data and evaluated the model performances in a separate cohort (n=74).Body-weight, amiodarone intake, VKORC1, CYP4F2, ABCB1 genotypes were retained in the final model, accounting for 31.5% of dose variability. None influence of CYP2C9 was observed. Our final model showed good performances: in 83.3% of the validation cohort patients, the dose was accurately predicted within 5 mg, i.e.the usual step used for adjusting fluindione dosage. In conclusion, in addition to body-weight and amiodarone-intake, pharmacogenetic factors (VKORC1, CYP4F2, ABCB1) related to the pharmacodynamic effect and transport of fluindione significantly influenced the dose requirement in elderly patients while CYP2C9 did not. Studies are required to know whether fluindione could be an alternative VKA in carriers of polymorphic CYP2C9 alleles, hypersensitive to coumarins.

  13. ISOLATION OF HEPATIC OVAL CELLS FROM DIFFERENT MODEL RATS INCLUDING DIABETIC RATS

    Institute of Scientific and Technical Information of China (English)

    LU Ying-li; YE Ting-ting; XIA Fang-zhen; WANG Ning-jian; YANG Hua; CHEN Yi

    2009-01-01

    Objective To acquire oval cells (progenitor stem cells) from adult rat liver of different models including diabetic rats. Methods Thirty Sprague-Dawley (SD) rats were divided into 5 groups randomly: control, 2-acetylaminofluorene (2-AAF), 2-AAF+partial hepatectomy (PH), 2-AAF+carbon tetrachloride (CCl4), and diabetic groups. As two-step collagenase perfusion protocol of Seglen, oval cells were isolated by Percoll density gradient centrifugation. Thy1.1 positive cells were sorted by flow cytometry, and then cultured in Dulbeccos minimum Eagles medium (DMEM). Immunofluorescence staining was applied to labelling Thy1.1. Results Different rates of Thy1.1 positive oval cells were found in different rat model groups: 0.5% in 2-AAF, 0.3% in 2-hAAF+PH, 0.2% in 2-AAF+CCl4 , 0.1% in diabetic, and 0.0% in control. Isolated cells adhered to plate with fusiform or polygon as epithelial cells. Conclusion Progenitor stem cells exist in injured liver tissue including those from diabetic rats.

  14. An alternant method to the traditional NASA hindlimb unloading model in mice.

    Science.gov (United States)

    Ferreira, J Andries; Crissey, Jacqueline M; Brown, Marybeth

    2011-03-10

    The Morey-Holton hindlimb unloading (HU) method is a widely accepted National Aeronautics and Space Administration (NASA) ground-based model for studying disuse-atrophy in rodents. Our study evaluated an alternant method to the gold-standard Morey-Holton HU tail-traction technique in mice. Fifty-four female mice (4-8 mo.) were HU for 14 days (n=34) or 28 days (n=20). Recovery from HU was assessed after 3 days of normal cage ambulation following HU (n=22). Aged matched mice (n=76) served as weight-bearing controls. Prior to HU a tail ring was formed with a 2-0 sterile surgical steel wire that was passed through the 5(th), 6(th), or 7(th) inter-vertebral disc space and shaped into a ring from which the mice were suspended. Vertebral location for the tail-ring was selected to appropriately balance animal body weight without interfering with defecation. We determined the success of this novel HU technique by assessing body weight before and after HU, degree of soleus atrophy, and adrenal mass following HU. Body weight of the mice prior to HU (24.3 ± 2.9g) did not significantly decline immediately after 14d of HU (22.7 ± 1.9g), 28d of HU (21.3 + 2.1g) or after 3 days recovery (24.0 ± 1.8g). Soleus muscle mass significantly declined (-39.1%, and -46.6%) following HU for 14 days and 28 days respectively (pmaintenance of animal body weight, comparable adrenal gland weights, and soleus atrophy following HU, corresponding to expected literature values. The primary advantages of this HU method include: 1) ease of tail examination during suspension; 2) decreased likelihood of cyanotic, inflamed, and/or necrotic tails frequently observed with tail-taping and HU; 3) no possibility of mice chewing the traction tape and coming out of the suspension apparatus; and 4) rapid recovery and normal cage activity immediately after HU.

  15. Matrix attachment regions included in a bicistronic vector enhances and stabilizes follistatin gene expressions in both transgenic cells and transgenic mice

    Directory of Open Access Journals (Sweden)

    Xiaoming HU,Jing GUO,Chunling BAI,Zhuying WEI,Li GAO,Tingmao HU,Shorgan BOU,Guangpeng LI

    2016-03-01

    Full Text Available In the present study, follistatin (FST gene expression vectors with either a bicistronic gene transfer cassette alone, or a bicistron gene cassette carrying a matrix attachment region (MAR were constructed and transfected to bovine fetal fibroblasts. Evaluations of both the integration and expression of exogenous FST indicated that the pMAR-CAG-FST-IRES-AcGFP1-polyA-MAR (pMAR-FST vector had higher capacity to form monoclonal transgenic cells than the vector without MAR, though transient transfection and integration efficiency were similar with either construct. Remarkably, protein expression in transgenic cells with the pMAR-FST vector was significantly higher than that from the bicistronic vector. Exogenous FST was expressed in all of the pMAR-FST transgenic mice at F0, F1 and F2. Total muscle growth in F0 mice was significantly greater than in wild-type mice, with larger muscles in fore and hind limbs of transgenic mice. pMAR-FST transgenic mice were also found with more evenly distributed muscle bundles and thinner spaces between sarcolemma, which suggests a correlation between transgene expression-associated muscle development and the trend of muscle growth. In conclusion, a pMAR-FST vector, which excluded the resistant genes and frame structure, enhances and stabilizes FST gene expressions in both transfected cells and transgenic mice.

  16. Animal models of physiologic markers of male reproduction: genetically defined infertile mice

    Energy Technology Data Exchange (ETDEWEB)

    Chubb, C.

    1987-10-01

    The present report focuses on novel animal models of male infertility: genetically defined mice bearing single-gene mutations that induce infertility. The primary goal of the investigations was to identify the reproductive defects in these mutant mice. The phenotypic effects of the gene mutations were deciphered by comparing the mutant mice to their normal siblings. Initially testicular steroidogenesis and spermatogenesis were investigated. The physiologic markers for testicular steroidogenesis were steroid secretion by testes perifused in vitro, seminal vesicle weight, and Leydig cell histology. Spermatogenesis was evaluated by the enumeration of homogenization-resistant sperm/spermatids in testes and by morphometric analyses of germ cells in the seminiferous epithelium. If testicular function appeared normal, the authors investigated the sexual behavior of the mice. The parameters of male sexual behavior that were quantified included mount patency, mount frequency, intromission latency, thrusts per intromission, ejaculation latency, and ejaculation duration. Females of pairs breeding under normal circumstances were monitored for the presence of vaginal plugs and pregnancies. The patency of the ejaculatory process was determined by quantifying sperm in the female reproductive tract after sexual behavior tests. Sperm function was studied by quantitatively determining sperm motility during videomicroscopic observation. Also, the ability of epididymal sperm to function within the uterine environment was analyzed by determining sperm capacity to initiate pregnancy after artificial insemination. Together, the experimental results permitted the grouping of the gene mutations into three general categories. They propose that the same biological markers used in the reported studies can be implemented in the assessment of the impact that environmental toxins may have on male reproduction.

  17. Dynamic modelling and analysis of multi-machine power systems including wind farms

    Science.gov (United States)

    Tabesh, Ahmadreza

    2005-11-01

    This thesis introduces a small-signal dynamic model, based on a frequency response approach, for the analysis of a multi-machine power system with special focus on an induction machine based wind farm. The proposed approach is an alternative method to the conventional eigenvalue analysis method which is widely employed for small-signal dynamic analyses of power systems. The proposed modelling approach is successfully applied and evaluated for a power system that (i) includes multiple synchronous generators, and (ii) a wind farm based on either fixed-speed, variable-speed, or doubly-fed induction machine based wind energy conversion units. The salient features of the proposed method, as compared with the conventional eigenvalue analysis method, are: (i) computational efficiency since the proposed method utilizes the open-loop transfer-function matrix of the system, (ii) performance indices that are obtainable based on frequency response data and quantitatively describe the dynamic behavior of the system, and (iii) capability to formulate various wind energy conversion unit, within a wind farm, in a modular form. The developed small-signal dynamic model is applied to a set of multi-machine study systems and the results are validated based on comparison (i) with digital time-domain simulation results obtained from PSCAD/EMTDC software tool, and (ii) where applicable with eigenvalue analysis results.

  18. A Hydrological Concept including Lateral Water Flow Compatible with the Biogeochemical Model ForSAFE

    Directory of Open Access Journals (Sweden)

    Giuliana Zanchi

    2016-03-01

    Full Text Available The study presents a hydrology concept developed to include lateral water flow in the biogeochemical model ForSAFE. The hydrology concept was evaluated against data collected at Svartberget in the Vindeln Research Forest in Northern Sweden. The results show that the new concept allows simulation of a saturated and an unsaturated zone in the soil as well as water flow that reaches the stream comparable to measurements. The most relevant differences compared to streamflow measurements are that the model simulates a higher base flow in winter and lower flow peaks after snowmelt. These differences are mainly caused by the assumptions made to regulate the percolation at the bottom of the simulated soil columns. The capability for simulating lateral flows and a saturated zone in ForSAFE can greatly improve the simulation of chemical exchange in the soil and export of elements from the soil to watercourses. Such a model can help improve the understanding of how environmental changes in the forest landscape will influence chemical loads to surface waters.

  19. Modeling within-host dynamics of influenza virus infection including immune responses.

    Directory of Open Access Journals (Sweden)

    Kasia A Pawelek

    Full Text Available Influenza virus infection remains a public health problem worldwide. The mechanisms underlying viral control during an uncomplicated influenza virus infection are not fully understood. Here, we developed a mathematical model including both innate and adaptive immune responses to study the within-host dynamics of equine influenza virus infection in horses. By comparing modeling predictions with both interferon and viral kinetic data, we examined the relative roles of target cell availability, and innate and adaptive immune responses in controlling the virus. Our results show that the rapid and substantial viral decline (about 2 to 4 logs within 1 day after the peak can be explained by the killing of infected cells mediated by interferon activated cells, such as natural killer cells, during the innate immune response. After the viral load declines to a lower level, the loss of interferon-induced antiviral effect and an increased availability of target cells due to loss of the antiviral state can explain the observed short phase of viral plateau in which the viral level remains unchanged or even experiences a minor second peak in some animals. An adaptive immune response is needed in our model to explain the eventual viral clearance. This study provides a quantitative understanding of the biological factors that can explain the viral and interferon kinetics during a typical influenza virus infection.

  20. A phase-field model for incoherent martensitic transformations including plastic accommodation processes in the austenite

    Science.gov (United States)

    Kundin, J.; Raabe, D.; Emmerich, H.

    2011-10-01

    If alloys undergo an incoherent martensitic transformation, then plastic accommodation and relaxation accompany the transformation. To capture these mechanisms we develop an improved 3D microelastic-plastic phase-field model. It is based on the classical concepts of phase-field modeling of microelastic problems (Chen, L.Q., Wang Y., Khachaturyan, A.G., 1992. Philos. Mag. Lett. 65, 15-23). In addition to these it takes into account the incoherent formation of accommodation dislocations in the austenitic matrix, as well as their inheritance into the martensitic plates based on the crystallography of the martensitic transformation. We apply this new phase-field approach to the butterfly-type martensitic transformation in a Fe-30 wt%Ni alloy in direct comparison to recent experimental data (Sato, H., Zaefferer, S., 2009. Acta Mater. 57, 1931-1937). It is shown that the therein proposed mechanisms of plastic accommodation during the transformation can indeed explain the experimentally observed morphology of the martensitic plates as well as the orientation between martensitic plates and the austenitic matrix. The developed phase-field model constitutes a general simulations approach for different kinds of phase transformation phenomena that inherently include dislocation based accommodation processes. The approach does not only predict the final equilibrium topology, misfit, size, crystallography, and aspect ratio of martensite-austenite ensembles resulting from a transformation, but it also resolves the associated dislocation dynamics and the distribution, and the size of the crystals itself.

  1. Smad3 knock-out mice as a useful model to study intestinal fibrogenesis

    Institute of Scientific and Technical Information of China (English)

    Giuliana Zanninelli; Giovanni Latella; Antonella Vetuschi; Roberta Sferra; Angela D'Angelo; Amato Fratticci; Maria Adelaide Continenza; Maria Chiaramonte; Eugenio Gaudio; Renzo Caprilli

    2006-01-01

    AIM: To evaluate the possible differences in morphology and immunohistochemical expression of CD3,transforming growth factor β1(TGF-β1), Smad7, α-smooth muscle actin (α-Sma), and collagen types Ⅰ-Ⅶ of small and large intestine in Smad3 null and wild-type mice.METHODS: Ten null and ten wild-type adult mice were sacrificed at 4 mo of age and the organs (esophagus, small and large bowel, ureters) were collected for histology(hematoxylin and eosin, Masson thrichrome,silver staining), morphometry and immunohistochemistry analysis. TGF-β1 levels of intestinal tissue homogenates were assessed by ELISA.RESULTS: No macroscopic intestinal lesions were detected both in null and wild-type mice. Histological and morphometric evaluation revealed a significant reduction in muscle layer thickness of small and large intestine in null mice as compared to wild-type mice. Immunohistochemistry evaluation showed a significant increase of CD3+T cell, TGF-β1 and Smad7 staining in the small and large intestine mucosa of Smad3 null mice as compared to wild-type mice. α-Sma and collagen Ⅰ-Ⅶ staining of small and large intestine did not differ between the two groups of mice. TGF-β1 levels of colonic tissue homogenates were significantly higher in null mice than in wild-type mice. In preliminary experiments a significant reduction of TNBS-induced intestinal fibrosis was observed in null mice as compared to wild-type mice.CONCLUSION: Smad3 null mice are a useful model to investigate the in vivo role of the TGF-β/Smad signalling pathway in intestinal inflammation and fibrosis.

  2. [BEHAVIOR, MEMORY AND IMMUNOLOGICAL STATUS IN MICE MODEL OF DESYNCHRONOSIS].

    Science.gov (United States)

    Dubrovina, N I; Shurlygina, A V; Litvinenko, G I; Melnikova, E V; Tenditnik, M V; Chasovskich, M I; Trufakin, V A

    2015-05-01

    Interstrain differences in behavior and parameters of the immune system of CBA and C57BL/6 mice with round the clock coverage (KO) were investigated. Open field, light/dark, acoustic startle response, forced swimming, elevated plus-maze, passive avoidance were used for measuring emotional behavior and memory. The number of lymphocyte subpopulations CD3+, CD4+8-, CD4-8+, CD4+8+, CD19+, CD3+hi spleen and thymus, the ratio of cells in different phases of the cell cycle was determined by flow cytometry. C57BL/6J mice strictly increased anxiety in response to the KO compared to CBA mice. Moreover, KO-treated C57BL/6J mice impaired the passive avoidance learning. We found that KO evoked significant changes in the cellular composition of the thymus and decrease of thymocytes proliferation in C57BL/6J mice. In opposite KO-treated CBA mice showed change of splenic cellular structure with increased % CD19+ cells and the proliferation of splenocytes. Our study demonstrated genotype-dependent reactions of the nervous and immune systems in response chronic constant light.

  3. Transmitochondrial mice as models for primary prevention of diseases caused by mutation in the tRNA(Lys) gene.

    Science.gov (United States)

    Shimizu, Akinori; Mito, Takayuki; Hayashi, Chisato; Ogasawara, Emi; Koba, Ryusuke; Negishi, Issei; Takenaga, Keizo; Nakada, Kazuto; Hayashi, Jun-Ichi

    2014-02-25

    We generated transmitochondrial mice (mito-mice) that carry a mutation in the tRNA(Lys) gene encoded by mtDNA for use in studies of its pathogenesis and transmission profiles. Because patients with mitochondrial diseases frequently carry mutations in the mitochondrial tRNA(Lys) and tRNA(Leu(UUR)) genes, we focused our efforts on identifying somatic mutations of these genes in mouse lung carcinoma P29 cells. Of the 43 clones of PCR products including the tRNA(Lys) or tRNA(Leu(UUR)) genes in mtDNA of P29 cells, one had a potentially pathogenic mutation (G7731A) in the tRNA(Lys) gene. P29 subclones with predominant amounts of G7731A mtDNA expressed respiration defects, thus suggesting the pathogenicity of this mutation. We then transferred G7731A mtDNA into mouse ES cells and obtained F0 chimeric mice. Mating these F0 mice with C57BL/6J (B6) male mice resulted in the generation of F1 mice with G7731A mtDNA, named "mito-mice-tRNA(Lys7731)." Maternal inheritance and random segregation of G7731A mtDNA occurred in subsequent generations. Mito-mice-tRNA(Lys7731) with high proportions of G7731A mtDNA exclusively expressed respiration defects and disease-related phenotypes and therefore are potential models for mitochondrial diseases due to mutations in the mitochondrial tRNA(Lys) gene. Moreover, the proportion of mutated mtDNA varied markedly among the pups born to each dam, suggesting that selecting oocytes with high proportions of normal mtDNA from affected mothers with tRNA(Lys)-based mitochondrial diseases may be effective as a primary prevention for obtaining unaffected children.

  4. A surplus production model including environmental effects: Application to the Senegalese white shrimp stocks

    Science.gov (United States)

    Thiaw, Modou; Gascuel, Didier; Jouffre, Didier; Thiaw, Omar Thiom

    2009-12-01

    In Senegal, two stocks of white shrimp ( Penaeusnotialis) are intensively exploited, one in the north and another in the south. We used surplus production models including environmental effects to analyse their changes in abundance over the past 10 years and to estimate their Maximum Sustainable Yield (MSY) and the related fishing effort ( EMSY). First, yearly abundance indices were estimated from commercial statistics using GLM techniques. Then, two environmental indices were alternatively tested in the model: the coastal upwelling intensity from wind speeds provided by the SeaWifs database and the primary production derived from satellite infrared images of chlorophyll a. Models were fitted, with or without the environmental effect, to the 1996-2005 time series. They express stock abundance and catches as functions of the fishing effort and the environmental index (when considered). For the northern stock, fishing effort and abundance fluctuate over the period without any clear trends. The model based on the upwelling index explains 64.9% of the year-to-year variability. It shows that the stock was slightly overexploited in 2002-2003 and is now close to full exploitation. Stock abundance strongly depends on environmental conditions; consequently, the MSY estimate varies from 300 to 900 tons according to the upwelling intensity. For the southern stock, fishing effort has strongly increased over the past 10 years, while abundance has been reduced 4-fold. The environment has a significant effect on abundance but only explains a small part of the year-to-year variability. The best fit is obtained using the primary production index ( R2 = 0.75), and the stock is now significantly overfished regardless of environmental conditions. MSY varies from 1200 to 1800 tons according to environmental conditions. Finally, in northern Senegal, the upwelling is highly variable from year to year and constitutes the major factor determining productivity. In the south, hydrodynamic

  5. Hybrid discrete-continuum modeling for transport, biofilm development and solid restructuring including electrostatic effects

    Science.gov (United States)

    Prechtel, Alexander; Ray, Nadja; Rupp, Andreas

    2017-04-01

    We want to present an approach for the mathematical, mechanistic modeling and numerical treatment of processes leading to the formation, stability, and turnover of soil micro-aggregates. This aims at deterministic aggregation models including detailed mechanistic pore-scale descriptions to account for the interplay of geochemistry and microbiology, and the link to soil functions as, e.g., the porosity. We therefore consider processes at the pore scale and the mesoscale (laboratory scale). At the pore scale transport by diffusion, advection, and drift emerging from electric forces can be taken into account, in addition to homogeneous and heterogeneous reactions of species. In the context of soil micro-aggregates the growth of biofilms or other glueing substances as EPS (extracellular polymeric substances) is important and affects the structure of the pore space in space and time. This model is upscaled mathematically in the framework of (periodic) homogenization to transfer it to the mesoscale resulting in effective coefficients/parameters there. This micro-macro model thus couples macroscopic equations that describe the transport and fluid flow at the scale of the porous medium (mesoscale) with averaged time- and space-dependent coefficient functions. These functions may be explicitly computed by means of auxiliary cell problems (microscale). Finally, the pore space in which the cell problems are defined is time and space dependent and its geometry inherits information from the transport equation's solutions. The microscale problems rely on versatile combinations of cellular automata and discontiuous Galerkin methods while on the mesoscale mixed finite elements are used. The numerical simulations allow to study the interplay between these processes.

  6. Environmental assessment of biofuel chains based on ecosystem modelling, including land-use change effects

    Science.gov (United States)

    Gabrielle, B.; Gagnaire, N.; Massad, R.; Prieur, V.; Python, Y.

    2012-04-01

    The potential greenhouse gas (GHG) savings resulting from the displacement of fossil energy sources by bioenergy mostly hinges on the uncertainty on the magnitude of nitrous oxide (N2O) emissions from arable soils occuring during feedstock production. These emissions are broadly related to fertilizer nitrogen input rates, but largely controlled by soil and climate factors which makes their estimation highly uncertain. Here, we set out to improve estimates of N2O emissions from bioenergy feedstocks by using ecosystem models and measurements and modeling of atmospheric N2O in the greater Paris (France) area. Ground fluxes were measured in two locations to assess the effect of soil type and management, crop type (including lignocellulosics such as triticale, switchgrass and miscanthus), and climate on N2O emission rates and dynamics. High-resolution maps of N2O emissions were generated over the Ile-de-France region (around Paris) with two ecosystem models using geographical databases on soils, weather data, land-use and crop management. The models were tested against ground flux measurements and the emission maps were fed into the atmospheric chemistry-transport model CHIMERE. The maps were tested by comparing the CHIMERE simulations with time series of N2O concentrations measured at various heights above the ground in two locations in 2007. The emissions of N2O, as integrated over the region, were used in a life-cycle assessment of representative biofuel pathways: bioethanol from wheat and sugar-beet (1st generation), and miscanthus (2nd generation chain); bio-diesel from oilseed rape. Effects related to direct and indirect land-use changes (in particular on soil carbon stocks) were also included in the assessment based on various land-use scenarios and literature references. The potential deployment of miscanthus was simulated by assuming it would be grown on the current sugar-beet growing area in Ile-de-France, or by converting land currently under permanent fallow

  7. Pitx3 deficient mice as a genetic animal model of co-morbid depressive disorder and parkinsonism.

    Science.gov (United States)

    Kim, Kyoung-Shim; Kang, Young-Mi; Kang, Young; Park, Tae-Shin; Park, Hye-Yeon; Kim, Yoon-Jung; Han, Baek-Soo; Kim, Chun-Hyung; Lee, Chul-Ho; Ardayfio, Paul A; Han, Pyung-Lim; Jung, Bong-Hyun; Kim, Kwang-Soo

    2014-03-13

    Approximately 40-50% of all patients with Parkinson׳s disease (PD) show symptoms and signs of depressive disorders, for which neither pathogenic understanding nor rational treatment are available. Using Pit3x-deficient mice, a model for selective nigrostriatal dopaminergic neurodegeneration, we tested depression-related behaviors and acute stress responses to better understand how a nigrostriatal dopaminergic deficit increases the prevalence of depressive disorders in PD patients. Pitx3-deficient mice showed decreased sucrose consumption and preference in the two-bottle free-choice test of anhedonia. Acute restraint stress increased c-Fos (known as a neuronal activity marker) expression levels in various brain regions, including the prefrontal cortex, striatum, nucleus accumbens, and paraventricular nucleus of the hypothalamus (PVN), in both Pitx3+/+ and -/- mice. However, the stress-induced increases in c-Fos levels in the cortex, dorsal striatum, and PVN were significantly greater in Pitx3-/- than +/+ mice, suggesting that signs of depressive disorders in parkinsonism are related to altered stress vulnerability. Based on these results, we propose that Pitx3-/- mice may serve as a useful genetic animal model for co-morbid depressive disorder and parkinsonism.

  8. Validation of gyrokinetic modelling of light impurity transport including rotation in ASDEX Upgrade

    CERN Document Server

    Casson, F J; Angioni, C; Camenen, Y; Dux, R; Fable, E; Fischer, R; Geiger, B; Manas, P; Menchero, L; Tardini, G

    2013-01-01

    Upgraded spectroscopic hardware and an improved impurity concentration calculation allow accurate determination of boron density in the ASDEX Upgrade tokamak. A database of boron measurements is compared to quasilinear and nonlinear gyrokinetic simulations including Coriolis and centrifugal rotational effects over a range of H-mode plasma regimes. The peaking of the measured boron profiles shows a strong anti-correlation with the plasma rotation gradient, via a relationship explained and reproduced by the theory. It is demonstrated that the rotodiffusive impurity flux driven by the rotation gradient is required for the modelling to reproduce the hollow boron profiles at higher rotation gradients. The nonlinear simulations validate the quasilinear approach, and, with the addition of perpendicular flow shear, demonstrate that each symmetry breaking mechanism that causes momentum transport also couples to rotodiffusion. At lower rotation gradients, the parallel compressive convection is required to match the mos...

  9. Models that include supercoiling of topological domains reproduce several known features of interphase chromosomes.

    Science.gov (United States)

    Benedetti, Fabrizio; Dorier, Julien; Burnier, Yannis; Stasiak, Andrzej

    2014-03-01

    Understanding the structure of interphase chromosomes is essential to elucidate regulatory mechanisms of gene expression. During recent years, high-throughput DNA sequencing expanded the power of chromosome conformation capture (3C) methods that provide information about reciprocal spatial proximity of chromosomal loci. Since 2012, it is known that entire chromatin in interphase chromosomes is organized into regions with strongly increased frequency of internal contacts. These regions, with the average size of ∼1 Mb, were named topological domains. More recent studies demonstrated presence of unconstrained supercoiling in interphase chromosomes. Using Brownian dynamics simulations, we show here that by including supercoiling into models of topological domains one can reproduce and thus provide possible explanations of several experimentally observed characteristics of interphase chromosomes, such as their complex contact maps.

  10. Modeling and analysis of overmodulation in erbium-doped fiber amplifiers including amplified spontaneous emission

    Science.gov (United States)

    Sharma, Reena; Raghuwanshi, Sanjeev Kumar

    2017-02-01

    Line surveillance and management information in erbium-doped fiber amplifiers (EDFAs) can be broadcast by modulating the amplitude of the low-frequency lightwave information signal, the process termed as overmodulation in the literature. This paper presents systematic solutions for the overmodulated pump and information signal transfer functions for EDFA. It includes amplified spontaneous emission (ASE) that has an impact on outcomes in the high-gain system. To the extent of our belief, the methodical model simulated with the current approach leads to a distinct perspective of an outcome in the respective field. The test bed described here is realistic. It specifically represents the overmodulation behavior in an EDFA under the influence of ASE.

  11. Specificity of anti-tau antibodies when analyzing mice models of Alzheimer's disease: problems and solutions.

    Directory of Open Access Journals (Sweden)

    Franck R Petry

    Full Text Available Aggregates of hyperphosphorylated tau protein are found in a group of diseases called tauopathies, which includes Alzheimer's disease. The causes and consequences of tau hyperphosphorylation are routinely investigated in laboratory animals. Mice are the models of choice as they are easily amenable to transgenic technology; consequently, their tau phosphorylation levels are frequently monitored by Western blotting using a panel of monoclonal/polyclonal anti-tau antibodies. Given that mouse secondary antibodies can recognize endogenous mouse immunoglobulins (Igs and the possible lack of specificity with some polyclonal antibodies, non-specific signals are commonly observed. Here, we characterized the profiles of commonly used anti-tau antibodies in four different mouse models: non-transgenic mice, tau knock-out (TKO mice, 3xTg-AD mice, and hypothermic mice, the latter a positive control for tau hyperphosphorylation. We identified 3 tau monoclonal antibody categories: type 1, characterized by high non-specificity (AT8, AT180, MC1, MC6, TG-3, type 2, demonstrating low non-specificity (AT270, CP13, CP27, Tau12, TG5, and type 3, with no non-specific signal (DA9, PHF-1, Tau1, Tau46. For polyclonal anti-tau antibodies, some displayed non-specificity (pS262, pS409 while others did not (pS199, pT205, pS396, pS404, pS422, A0024. With monoclonal antibodies, most of the interfering signal was due to endogenous Igs and could be eliminated by different techniques: i using secondary antibodies designed to bind only non-denatured Igs, ii preparation of a heat-stable fraction, iii clearing Igs from the homogenates, and iv using secondary antibodies that only bind the light chain of Igs. All of these techniques removed the non-specific signal; however, the first and the last methods were easier and more reliable. Overall, our study demonstrates a high risk of artefactual signal when performing Western blotting with routinely used anti-tau antibodies, and proposes

  12. Multi-Tissue Computational Modeling Analyzes Pathophysiology of Type 2 Diabetes in MKR Mice

    Science.gov (United States)

    Kumar, Amit; Harrelson, Thomas; Lewis, Nathan E.; Gallagher, Emily J.; LeRoith, Derek; Shiloach, Joseph; Betenbaugh, Michael J.

    2014-01-01

    Computational models using metabolic reconstructions for in silico simulation of metabolic disorders such as type 2 diabetes mellitus (T2DM) can provide a better understanding of disease pathophysiology and avoid high experimentation costs. There is a limited amount of computational work, using metabolic reconstructions, performed in this field for the better understanding of T2DM. In this study, a new algorithm for generating tissue-specific metabolic models is presented, along with the resulting multi-confidence level (MCL) multi-tissue model. The effect of T2DM on liver, muscle, and fat in MKR mice was first studied by microarray analysis and subsequently the changes in gene expression of frank T2DM MKR mice versus healthy mice were applied to the multi-tissue model to test the effect. Using the first multi-tissue genome-scale model of all metabolic pathways in T2DM, we found out that branched-chain amino acids' degradation and fatty acids oxidation pathway is downregulated in T2DM MKR mice. Microarray data showed low expression of genes in MKR mice versus healthy mice in the degradation of branched-chain amino acids and fatty-acid oxidation pathways. In addition, the flux balance analysis using the MCL multi-tissue model showed that the degradation pathways of branched-chain amino acid and fatty acid oxidation were significantly downregulated in MKR mice versus healthy mice. Validation of the model was performed using data derived from the literature regarding T2DM. Microarray data was used in conjunction with the model to predict fluxes of various other metabolic pathways in the T2DM mouse model and alterations in a number of pathways were detected. The Type 2 Diabetes MCL multi-tissue model may explain the high level of branched-chain amino acids and free fatty acids in plasma of Type 2 Diabetic subjects from a metabolic fluxes perspective. PMID:25029527

  13. Multi-tissue computational modeling analyzes pathophysiology of type 2 diabetes in MKR mice.

    Directory of Open Access Journals (Sweden)

    Amit Kumar

    Full Text Available Computational models using metabolic reconstructions for in silico simulation of metabolic disorders such as type 2 diabetes mellitus (T2DM can provide a better understanding of disease pathophysiology and avoid high experimentation costs. There is a limited amount of computational work, using metabolic reconstructions, performed in this field for the better understanding of T2DM. In this study, a new algorithm for generating tissue-specific metabolic models is presented, along with the resulting multi-confidence level (MCL multi-tissue model. The effect of T2DM on liver, muscle, and fat in MKR mice was first studied by microarray analysis and subsequently the changes in gene expression of frank T2DM MKR mice versus healthy mice were applied to the multi-tissue model to test the effect. Using the first multi-tissue genome-scale model of all metabolic pathways in T2DM, we found out that branched-chain amino acids' degradation and fatty acids oxidation pathway is downregulated in T2DM MKR mice. Microarray data showed low expression of genes in MKR mice versus healthy mice in the degradation of branched-chain amino acids and fatty-acid oxidation pathways. In addition, the flux balance analysis using the MCL multi-tissue model showed that the degradation pathways of branched-chain amino acid and fatty acid oxidation were significantly downregulated in MKR mice versus healthy mice. Validation of the model was performed using data derived from the literature regarding T2DM. Microarray data was used in conjunction with the model to predict fluxes of various other metabolic pathways in the T2DM mouse model and alterations in a number of pathways were detected. The Type 2 Diabetes MCL multi-tissue model may explain the high level of branched-chain amino acids and free fatty acids in plasma of Type 2 Diabetic subjects from a metabolic fluxes perspective.

  14. Exergoeconomic performance optimization for a steady-flow endoreversible refrigeration model including six typical cycles

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Lingen; Kan, Xuxian; Sun, Fengrui; Wu, Feng [College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033 (China)

    2013-07-01

    The operation of a universal steady flow endoreversible refrigeration cycle model consisting of a constant thermal-capacity heating branch, two constant thermal-capacity cooling branches and two adiabatic branches is viewed as a production process with exergy as its output. The finite time exergoeconomic performance optimization of the refrigeration cycle is investigated by taking profit rate optimization criterion as the objective. The relations between the profit rate and the temperature ratio of working fluid, between the COP (coefficient of performance) and the temperature ratio of working fluid, as well as the optimal relation between profit rate and the COP of the cycle are derived. The focus of this paper is to search the compromised optimization between economics (profit rate) and the utilization factor (COP) for endoreversible refrigeration cycles, by searching the optimum COP at maximum profit, which is termed as the finite-time exergoeconomic performance bound. Moreover, performance analysis and optimization of the model are carried out in order to investigate the effect of cycle process on the performance of the cycles using numerical example. The results obtained herein include the performance characteristics of endoreversible Carnot, Diesel, Otto, Atkinson, Dual and Brayton refrigeration cycles.

  15. Exergoeconomic performance optimization for a steady-flow endoreversible refrigeration model including six typical cycles

    Directory of Open Access Journals (Sweden)

    Lingen Chen, Xuxian Kan, Fengrui Sun, Feng Wu

    2013-01-01

    Full Text Available The operation of a universal steady flow endoreversible refrigeration cycle model consisting of a constant thermal-capacity heating branch, two constant thermal-capacity cooling branches and two adiabatic branches is viewed as a production process with exergy as its output. The finite time exergoeconomic performance optimization of the refrigeration cycle is investigated by taking profit rate optimization criterion as the objective. The relations between the profit rate and the temperature ratio of working fluid, between the COP (coefficient of performance and the temperature ratio of working fluid, as well as the optimal relation between profit rate and the COP of the cycle are derived. The focus of this paper is to search the compromised optimization between economics (profit rate and the utilization factor (COP for endoreversible refrigeration cycles, by searching the optimum COP at maximum profit, which is termed as the finite-time exergoeconomic performance bound. Moreover, performance analysis and optimization of the model are carried out in order to investigate the effect of cycle process on the performance of the cycles using numerical example. The results obtained herein include the performance characteristics of endoreversible Carnot, Diesel, Otto, Atkinson, Dual and Brayton refrigeration cycles.

  16. Challenges of including nitrogen effects on decomposition in earth system models

    Science.gov (United States)

    Hobbie, S. E.

    2011-12-01

    Despite the importance of litter decomposition for ecosystem fertility and carbon balance, key uncertainties remain about how this fundamental process is affected by nitrogen (N) availability. Nevertheless, resolving such uncertainties is critical for mechanistic inclusion of such processes in earth system models, towards predicting the ecosystem consequences of increased anthropogenic reactive N. Towards that end, we have conducted a series of experiments examining nitrogen effects on litter decomposition. We found that both substrate N and externally supplied N (regardless of form) accelerated the initial decomposition rate. Faster initial decomposition rates were linked to the higher activity of carbohydrate-degrading enzymes associated with externally supplied N and the greater relative abundances of Gram negative and Gram positive bacteria associated with green leaves and externally supplied organic N (assessed using phospholipid fatty acid analysis, PLFA). By contrast, later in decomposition, externally supplied N slowed decomposition, increasing the fraction of slowly decomposing litter and reducing lignin-degrading enzyme activity and relative abundances of Gram negative and Gram positive bacteria. Our results suggest that elevated atmospheric N deposition may have contrasting effects on the dynamics of different soil carbon pools, decreasing mean residence times of active fractions comprising very fresh litter, while increasing those of more slowly decomposing fractions including more processed litter. Incorporating these contrasting effects of N on decomposition processes into models is complicated by lingering uncertainties about how these effects generalize across ecosystems and substrates.

  17. A Model for One-Dimensional Coherent Synchrotron Radiation including Short-Range Effects

    CERN Document Server

    Ryne, Robert D; Qiang, Ji; Yampolsky, Nikolai

    2012-01-01

    A new model is presented for simulating coherent synchrotron radiation (CSR) in one dimension. The method is based on convolving an integrated Green function (IGF) with the longitudinal charge density. Since it is based on an IGF, the accuracy of this approach is determined by how well one resolves the charge density and not by resolving the single particle wake function. Since short-range wakefield effects are included analytically, the approach can be much more efficient than ordinary (non-IGF) approaches in situations where the wake function and charge density have disparate spatial scales. Two cases are presented: one derived from the full wake including short-range effects, and one derived from the asymptotic wake. In the latter case the algorithm contains the same physics as others based on the asymptotic approximation, but requires only the line charge density and not its derivative. Examples are presented that illustrate the limitations of the asymptotic-wake approximation, and that illustrate how mic...

  18. INTERIOR MODELS OF SATURN: INCLUDING THE UNCERTAINTIES IN SHAPE AND ROTATION

    Energy Technology Data Exchange (ETDEWEB)

    Helled, Ravit [Department of Geophysics, Atmospheric and Planetary Sciences, Tel-Aviv University, Tel-Aviv (Israel); Guillot, Tristan [Universite de Nice-Sophia Antipolis, Observatoire de la Cote d' Azur, CNRS UMR 7293, BP 4229, F-06304 Nice (France)

    2013-04-20

    The accurate determination of Saturn's gravitational coefficients by Cassini could provide tighter constraints on Saturn's internal structure. Also, occultation measurements provide important information on the planetary shape which is often not considered in structure models. In this paper we explore how wind velocities and internal rotation affect the planetary shape and the constraints on Saturn's interior. We show that within the geodetic approach the derived physical shape is insensitive to the assumed deep rotation. Saturn's re-derived equatorial and polar radii at 100 mbar are found to be 54,445 {+-} 10 km and 60,365 {+-} 10 km, respectively. To determine Saturn's interior, we use one-dimensional three-layer hydrostatic structure models and present two approaches to include the constraints on the shape. These approaches, however, result in only small differences in Saturn's derived composition. The uncertainty in Saturn's rotation period is more significant: with Voyager's 10{sup h}39{sup m} period, the derived mass of heavy elements in the envelope is 0-7 M{sub Circled-Plus }. With a rotation period of 10{sup h}32{sup m}, this value becomes <4 M{sub Circled-Plus }, below the minimum mass inferred from spectroscopic measurements. Saturn's core mass is found to depend strongly on the pressure at which helium phase separation occurs, and is estimated to be 5-20 M{sub Circled-Plus }. Lower core masses are possible if the separation occurs deeper than 4 Mbar. We suggest that the analysis of Cassini's radio occultation measurements is crucial to test shape models and could lead to constraints on Saturn's rotation profile and departures from hydrostatic equilibrium.

  19. High performance computation of landscape genomic models including local indicators of spatial association.

    Science.gov (United States)

    Stucki, S; Orozco-terWengel, P; Forester, B R; Duruz, S; Colli, L; Masembe, C; Negrini, R; Landguth, E; Jones, M R; Bruford, M W; Taberlet, P; Joost, S

    2016-11-01

    With the increasing availability of both molecular and topo-climatic data, the main challenges facing landscape genomics - that is the combination of landscape ecology with population genomics - include processing large numbers of models and distinguishing between selection and demographic processes (e.g. population structure). Several methods address the latter, either by estimating a null model of population history or by simultaneously inferring environmental and demographic effects. Here we present samβada, an approach designed to study signatures of local adaptation, with special emphasis on high performance computing of large-scale genetic and environmental data sets. samβada identifies candidate loci using genotype-environment associations while also incorporating multivariate analyses to assess the effect of many environmental predictor variables. This enables the inclusion of explanatory variables representing population structure into the models to lower the occurrences of spurious genotype-environment associations. In addition, samβada calculates local indicators of spatial association for candidate loci to provide information on whether similar genotypes tend to cluster in space, which constitutes a useful indication of the possible kinship between individuals. To test the usefulness of this approach, we carried out a simulation study and analysed a data set from Ugandan cattle to detect signatures of local adaptation with samβada, bayenv, lfmm and an FST outlier method (FDIST approach in arlequin) and compare their results. samβada - an open source software for Windows, Linux and Mac OS X available at http://lasig.epfl.ch/sambada - outperforms other approaches and better suits whole-genome sequence data processing.

  20. Including oxygen enhancement ratio in ion beam treatment planning: model implementation and experimental verification

    Science.gov (United States)

    Scifoni, E.; Tinganelli, W.; Weyrather, W. K.; Durante, M.; Maier, A.; Krämer, M.

    2013-06-01

    We present a method for adapting a biologically optimized treatment planning for particle beams to a spatially inhomogeneous tumor sensitivity due to hypoxia, and detected e.g., by PET functional imaging. The TRiP98 code, established treatment planning system for particles, has been extended for including explicitly the oxygen enhancement ratio (OER) in the biological effect calculation, providing the first set up of a dedicated ion beam treatment planning approach directed to hypoxic tumors, TRiP-OER, here reported together with experimental tests. A simple semi-empirical model for calculating the OER as a function of oxygen concentration and dose averaged linear energy transfer, generating input tables for the program is introduced. The code is then extended in order to import such tables coming from the present or alternative models, accordingly and to perform forward and inverse planning, i.e., predicting the survival response of differently oxygenated areas as well as optimizing the required dose for restoring a uniform survival effect in the whole irradiated target. The multiple field optimization results show how the program selects the best beam components for treating the hypoxic regions. The calculations performed for different ions, provide indications for the possible clinical advantages of a multi-ion treatment. Finally the predictivity of the code is tested through dedicated cell culture experiments on extended targets irradiation using specially designed hypoxic chambers, providing a qualitative agreement, despite some limits in full survival calculations arising from the RBE assessment. The comparison of the predictions resulting by using different model tables are also reported.

  1. Testosterone is essential for skeletal muscle growth in aged mice in a heterochronic parabiosis model.

    Science.gov (United States)

    Sinha, Indranil; Sinha-Hikim, Amiya P; Wagers, Amy J; Sinha-Hikim, Indrani

    2014-09-01

    As humans age, they lose both muscle mass and strength (sarcopenia). Testosterone, a circulating hormone, progressively declines in aging and is associated with loss of muscle mass and strength. The surgical joining of a young and old mouse (heterochronic parabiosis) activates Notch signaling and restores muscle regenerative potential in aged mice. We hypothesize that testosterone is at least one of the factors required for the improvement seen in muscles in old mice in heterochronic parabiosis with young mice. To test this hypothesis, we established the following heterochronic parabioses between young (Y; 5 months old) and old (O; 22-23 months old) C57BL6 male mice: (1) Y:O; (2) castrated Y:O (ØY:O); (3) castrated + testosterone-treated Y:O (ØY + T:O). A group of normal young mice received empty implants, and old mice were used as controls. Parabiotic pairings were maintained for 4 weeks prior to analysis. Serum testosterone levels were three-fold higher in young than in old mice. The ØY + T:O pairing demonstrated significantly elevated levels of serum testosterone and an improvement in gastrocnemius muscle weight, muscle ultrastructure, muscle fiber cross-sectional area, and Notch-1 expression in old mice. These changes were not present in aged mice in the ØY:O pairing. These data indicate that testosterone has a critical role in mediating the improved muscle mass and ultrastructure seen in an experimental model of heterochronic parabiosis.

  2. Sleep disturbances in highly stress reactive mice: Modeling endophenotypes of major depression

    Directory of Open Access Journals (Sweden)

    Landgraf Rainer

    2011-03-01

    Full Text Available Abstract Background Neuronal mechanisms underlying affective disorders such as major depression (MD are still poorly understood. By selectively breeding mice for high (HR, intermediate (IR, or low (LR reactivity of the hypothalamic-pituitary-adrenocortical (HPA axis, we recently established a new genetic animal model of extremes in stress reactivity (SR. Studies characterizing this SR mouse model on the behavioral, endocrine, and neurobiological levels revealed several similarities with key endophenotypes observed in MD patients. HR mice were shown to have changes in rhythmicity and sleep measures such as rapid eye movement sleep (REMS and non-REM sleep (NREMS as well as in slow wave activity, indicative of reduced sleep efficacy and increased REMS. In the present study we were interested in how far a detailed spectral analysis of several electroencephalogram (EEG parameters, including relevant frequency bands, could reveal further alterations of sleep architecture in this animal model. Eight adult males of each of the three breeding lines were equipped with epidural EEG and intramuscular electromyogram (EMG electrodes. After recovery, EEG and EMG recordings were performed for two days. Results Differences in the amount of REMS and wakefulness and in the number of transitions between vigilance states were found in HR mice, when compared with IR and LR animals. Increased frequencies of transitions from NREMS to REMS and from REMS to wakefulness in HR animals were robust across the light-dark cycle. Detailed statistical analyses of spectral EEG parameters showed that especially during NREMS the power of the theta (6-9 Hz, alpha (10-15 Hz and eta (16-22.75 Hz bands was significantly different between the three breeding lines. Well defined distributions of significant power differences could be assigned to different times during the light and the dark phase. Especially during NREMS, group differences were robust and could be continuously monitored

  3. Using ICR and SCID mice as animal models for smallpox to assess antiviral drug efficacy.

    Science.gov (United States)

    Titova, Ksenya A; Sergeev, Alexander A; Zamedyanskaya, Alena S; Galahova, Darya O; Kabanov, Alexey S; Morozova, Anastasia A; Bulychev, Leonid E; Sergeev, Artemiy A; Glotova, Tanyana I; Shishkina, Larisa N; Taranov, Oleg S; Omigov, Vladimir V; Zavjalov, Evgenii L; Agafonov, Alexander P; Sergeev, Alexander N

    2015-09-01

    The possibility of using immunocompetent ICR mice and immunodeficient SCID mice as model animals for smallpox to assess antiviral drug efficacy was investigated. Clinical signs of the disease did not appear following intranasal (i.n.) challenge of mice with strain Ind-3a of variola virus (VARV), even when using the highest possible dose of the virus (5.2 log10 p.f.u.). The 50 % infective doses (ID50) of VARV, estimated by the virus presence or absence in the lungs 3 and 4 days post-infection, were 2.7 ± 0.4 log10 p.f.u. for ICR mice and 3.5 ± 0.7 log10 p.f.u. for SCID mice. After i.n. challenge of ICR and SCID mice with VARV 30 and 50 ID50, respectively, steady reproduction of the virus occurred only in the respiratory tract (lungs and nose). Pathological inflammatory destructive changes were revealed in the respiratory tract and the primary target cells for VARV (macrophages and epithelial cells) in mice, similar to those in humans and cynomolgus macaques. The use of mice to assess antiviral efficacies of NIOCH-14 and ST-246 demonstrated the compliance of results with those described in scientific literature, which opens up the prospect of their use as an animal model for smallpox to develop anti-smallpox drugs intended for humans.

  4. Analysis of mice tumor models using dynamic MRI data and a dedicated software platform

    Energy Technology Data Exchange (ETDEWEB)

    Alfke, H.; Maurer, E.; Klose, K.J. [Philipps Univ. Marburg (Germany). Dept. of Radiology; Kohle, S.; Rascher-Friesenhausen, R.; Behrens, S.; Peitgen, H.O. [MeVis - Center for Medical Diagnostic Systems and Visualization, Bremen (Germany); Celik, I. [Philipps Univ. Marburg (Germany). Inst. for Theoretical Surgery; Heverhagen, J.T. [Philipps Univ. Marburg (Germany). Dept. of Radiology; Ohio State Univ., Columbus (United States). Dept. of Radiology

    2004-09-01

    Purpose: To implement a software platform (DynaVision) dedicated to analyze data from functional imaging of tumors with different mathematical approaches, and to test the software platform in pancreatic carcinoma xenografts in mice with severe combined immunodeficiency disease (SCID). Materials and Methods: A software program was developed for extraction and visualization of tissue perfusion parameters from dynamic contrast-enhanced images. This includes regional parameter calculation from enhancement curves, parametric images (e.g., blood flow), animation, 3D visualization, two-compartment modeling a mode for comparing different datasets (e.g., therapy monitoring), and motion correction. We analyzed xenograft tumors from two pancreatic carcinoma cell lines (B x PC3 and ASPC1) implanted in 14 SCID mice after injection of Gd-DTPA into the tail vein. These data were correlated with histopathological findings. Results: Image analysis was completed in approximately 15 minutes per data set. The possibility of drawing and editing ROIs within the whole data set makes it easy to obtain quantitative data from the intensity-time curves. In one animal, motion artifacts reduced the image quality to a greater extent but data analysis was still possible after motion correction. Dynamic MRI of mice tumor models revealed a highly heterogeneous distribution of the contrast-enhancement curves and derived parameters, which correlated with differences in histopathology. ASPc1 tumors showed a more hypervascular type of curves with faster and higher signal enhancement rate (wash-in) and a faster signal decrease (wash-out). BXPC3 tumors showed a more hypovascular type with slower wash-in and wash-out. This correlated with the biological properties of the tumors. (orig.)

  5. Modeling socially anhedonic syndromes: genetic and pharmacological manipulation of opioid neurotransmission in mice.

    Science.gov (United States)

    Cinque, C; Pondiki, S; Oddi, D; Di Certo, M G; Marinelli, S; Troisi, A; Moles, A; D'Amato, F R

    2012-08-28

    Social anhedonia, or the diminished capacity to experience pleasure and reward from social affiliation, is a major symptom of different psychiatric disorders, including some forms of infantile autism and schizophrenia spectrum disorders. The brain opioid hypothesis of social attachment is a promising model for achieving insights into how neurobiological and developmental factors contribute to the regulation of social reward. In this study, genetic knocking-out and naltrexone (NTRX) treatment during the first 4 days of life were used to disrupt opioid neurotransmission in mouse pups and their attachment relationships with the mother. Both permanent (genetic) and transient (pharmacological) manipulations of opioid neurotransmission exerted long-term effects on social affiliation. When juveniles, both μ-opioid receptor knockout mice and NTRX-treated pups showed reduced interest in peers and no preference for socially rewarding environment. These results demonstrate that sociability in juvenile mice is highly dependent on the establishment during infancy of a positive affective relationship with their mothers and that opioid neurotransmission has a major role in the regulation of social hedonic capacity. If the validity of this animal model will be confirmed by future research, translational studies focusing on the interaction between early experience and opioid neurotransmission could provide useful insights for identifying endophenotypes of human psychiatric disorders associated with social anhedonia.

  6. Gene expression analysis of pancreatic cystic neoplasm in SV40Tag transgenic mice model

    Institute of Scientific and Technical Information of China (English)

    Jie Feng; Qiang Sun; Cheng Gao; Juan Dong; Xiao-Luan Wei; Hua Xing; Hou-Da Li

    2007-01-01

    AIM: To study the gene expression changes in pancreatic cystic neoplasm in SV40Tag transgenic mice model and to provide information about the prevention,clinical diagnosis and therapy of pancreatic cancer.METHODS: Using the pBC-SV40Tag transgenic mice model of pancreatic cystic neoplasm, we studied the gene expression changes by applying high-density microarrays. Validation of part gene expression profiling data was performed using real-time PCR.RESULTS: By using high-density oligonucleotide microarray, of 14113 genes, 453 were increased and 760 decreased in pancreatic cystic neoplasm, including oncogenes, cell-cycle-related genes, signal transduction-related genes, skeleton-related genes and metabolism-related genes. Among these, we confirmed the changes in Igf, Shh and Wnt signal pathways with real-time PCR.The results of real-time PCR showed similar expression changes in gene chip.CONCLUSION: all the altered expression genes are associated with cell cycle, DNA damage and repair, signal pathway, and metabolism. SV40Tag may cooperate with several proteins in promoting tumorigenesis.

  7. Differences in the pathways for metabolism of benzene in rats and mice simulated by a physiological model.

    Science.gov (United States)

    Medinsky, M A; Sabourin, P J; Henderson, R F; Lucier, G; Birnbaum, L S

    1989-07-01

    Studies conducted by the National Toxicology Program on the chronic toxicity of benzene indicated that B6C3F1 mice were more sensitive to the carcinogenic effects of benzene than were F344 rats. A physiological model was developed to describe the uptake and metabolism of benzene in rats and mice. Our objective was to determine if differences in toxic effects could be explained by differences in pathways for benzene metabolism or by differences in total uptake of benzene. Compartments incorporated into the model included liver, fat, a poorly perfused tissue group, a richly perfused tissue group, an alveolar or lung compartment and blood. Metabolism of benzene was assumed to take place only in the liver and to proceed by four major competing pathways. These included formation of hydroquinone conjugates (HQC), formation of phenyl conjugates (PHC), ring-breakage and formation of muconic acid (MUC), and conjugation with glutathione with subsequent mercapturic acid (PMA) formation. Values for parameters such as alveolar ventilation, cardiac output, organ volumes, blood flow, partition coefficients, and metabolic rate constants were taken from the literature. Model simulations confirmed that during and after 6-hr inhalation exposures mice metabolized more benzene on a mumole per kilogram body weight basis than did rats. After oral exposure, rats metabolized more benzene than mice at doses above 50 mg/kg because of the more rapid absorption and exhalation of benzene by mice. Model simulations for PHC and PMA, generally considered to be detoxification metabolites, were similar in shape and dose-response to those for total metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Differences in the pathways for metabolism of benzene in rats and mice simulated by a physiological model.

    Science.gov (United States)

    Medinsky, M A; Sabourin, P J; Henderson, R F; Lucier, G; Birnbaum, L S

    1989-01-01

    Studies conducted by the National Toxicology Program on the chronic toxicity of benzene indicated that B6C3F1 mice were more sensitive to the carcinogenic effects of benzene than were F344 rats. A physiological model was developed to describe the uptake and metabolism of benzene in rats and mice. Our objective was to determine if differences in toxic effects could be explained by differences in pathways for benzene metabolism or by differences in total uptake of benzene. Compartments incorporated into the model included liver, fat, a poorly perfused tissue group, a richly perfused tissue group, an alveolar or lung compartment and blood. Metabolism of benzene was assumed to take place only in the liver and to proceed by four major competing pathways. These included formation of hydroquinone conjugates (HQC), formation of phenyl conjugates (PHC), ring-breakage and formation of muconic acid (MUC), and conjugation with glutathione with subsequent mercapturic acid (PMA) formation. Values for parameters such as alveolar ventilation, cardiac output, organ volumes, blood flow, partition coefficients, and metabolic rate constants were taken from the literature. Model simulations confirmed that during and after 6-hr inhalation exposures mice metabolized more benzene on a mumole per kilogram body weight basis than did rats. After oral exposure, rats metabolized more benzene than mice at doses above 50 mg/kg because of the more rapid absorption and exhalation of benzene by mice. Model simulations for PHC and PMA, generally considered to be detoxification metabolites, were similar in shape and dose-response to those for total metabolism.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2792050

  9. Mathematical and numerical model of directional solidification including initial and terminal transients of the process

    Directory of Open Access Journals (Sweden)

    W. Kapturkiewicz

    2008-12-01

    Full Text Available The, developed in this study, simple model and numerical solution of diffusion growth of the solid phase under the conditions of directional solidification allow for the effect of constituent diffusion in both liquid and solid phase and assume the process run in which (like in reality the preset parameter is the velocity of sample (pulling velocity at a preset temperature gradient. The solid/liquid interface velocity is not the process parameter (like it is in numerous other solutions proposed so far but a function of this process. The effect of convection outside the diffusion layer has been included in mass balance under the assumption that in the zone of convection the mixing is complete. The above assumptions enabled solving the kinetics of growth of the solid phase (along with the diffusion field in solid and liquid phase under the conditions of diffusion well reflecting the process run starting with the initial transient state, going through the steady state period in central part of the casting, and ending in a terminal transient state. In the numerical solution obtained by the finite difference method with variable grid dimensions, the error of the mass control balance over the whole process range was 1 - 2 %.

  10. Human CD34+ CD133+ hematopoietic stem cells cultured with growth factors including Angptl5 efficiently engraft adult NOD-SCID Il2rγ-/- (NSG mice.

    Directory of Open Access Journals (Sweden)

    Adam C Drake

    Full Text Available Increasing demand for human hematopoietic stem cells (HSCs in clinical and research applications necessitates expansion of HSCs in vitro. Before these cells can be used they must be carefully evaluated to assess their stem cell activity. Here, we expanded cord blood CD34(+ CD133(+ cells in a defined medium containing angiopoietin like 5 and insulin-like growth factor binding protein 2 and evaluated the cells for stem cell activity in NOD-SCID Il2rg(-/- (NSG mice by multi-lineage engraftment, long term reconstitution, limiting dilution and serial reconstitution. The phenotype of expanded cells was characterized by flow cytometry during the course of expansion and following engraftment in mice. We show that the SCID repopulating activity resides in the CD34(+ CD133(+ fraction of expanded cells and that CD34(+ CD133(+ cell number correlates with SCID repopulating activity before and after culture. The expanded cells mediate long-term hematopoiesis and serial reconstitution in NSG mice. Furthermore, they efficiently reconstitute not only neonate but also adult NSG recipients, generating human blood cell populations similar to those reported in mice reconstituted with uncultured human HSCs. These findings suggest an expansion of long term HSCs in our culture and show that expression of CD34 and CD133 serves as a marker for HSC activity in human cord blood cell cultures. The ability to expand human HSCs in vitro should facilitate clinical use of HSCs and large-scale construction of humanized mice from the same donor for research applications.

  11. Behavioral characterization of cereblon forebrain-specific conditional null mice: a model for human non-syndromic intellectual disability.

    Science.gov (United States)

    Rajadhyaksha, Anjali M; Ra, Stephen; Kishinevsky, Sarah; Lee, Anni S; Romanienko, Peter; DuBoff, Mariel; Yang, Chingwen; Zupan, Bojana; Byrne, Maureen; Daruwalla, Zeeba R; Mark, Willie; Kosofsky, Barry E; Toth, Miklos; Higgins, Joseph J

    2012-01-15

    A nonsense mutation in the human cereblon gene (CRBN) causes a mild type of autosomal recessive non-syndromic intellectual disability (ID). Animal studies show that crbn is a cytosolic protein with abundant expression in the hippocampus (HPC) and neocortex (CTX). Its diverse functions include the developmental regulation of ion channels at the neuronal synapse, the mediation of developmental programs by ubiquitination, and a target for herpes simplex type I virus in HPC neurons. To test the hypothesis that anomalous CRBN expression leads to HPC-mediated memory and learning deficits, we generated germ-line crbn knock-out mice (crbn(-/-)). We also inactivated crbn in forebrain neurons in conditional knock-out mice in which crbn exons 3 and 4 are deleted by cre recombinase under the direction of the Ca(2+)/calmodulin-dependent protein kinase II alpha promoter (CamKII(cre/+), crbn(-/-)). crbn mRNA levels were negligible in the HPC, CTX, and cerebellum (CRBM) of the crbn(-/-) mice. In contrast, crbn mRNA levels were reduced 3- to 4-fold in the HPC, CTX but not in the CRBM in CamKII(cre/+), crbn(-/-) mice as compared to wild type (CamKII(cre/+), crbn(+/+)). Contextual fear conditioning showed a significant decrease in the percentage of freezing time in CamKII(cre/+), crbn(-/-) and crbn(-/-) mice while motor function, exploratory motivation, and anxiety-related behaviors were normal. These findings suggest that CamKII(cre/+), crbn(-/-) mice exhibit selective HPC-dependent deficits in associative learning and supports the use of these mice as in vivo models to study the functional consequences of CRBN aberrations on memory and learning in humans.

  12. Modeling Energy Dynamics in Mice with Skeletal Muscle Hypertrophy Fed High Calorie Diets.

    Science.gov (United States)

    Bond, Nichole D; Guo, Juen; Hall, Kevin D; McPherron, Alexandra C

    2016-01-01

    Retrospective and prospective studies show that lean mass or strength is positively associated with metabolic health. Mice deficient in myostatin, a growth factor that negatively regulates skeletal muscle mass, have increased muscle and body weights and are resistant to diet-induced obesity. Their leanness is often attributed to higher energy expenditure in the face of normal food intake. However, even obese animals have an increase in energy expenditure compared to normal weight animals suggesting this is an incomplete explanation. We have previously developed a computational model to estimate energy output, fat oxidation and respiratory quotient from food intake and body composition measurements to more accurately account for changes in body composition in rodents over time. Here we use this approach to understand the dynamic changes in energy output, intake, fat oxidation and respiratory quotient in muscular mice carrying a dominant negative activin receptor IIB expressed specifically in muscle. We found that muscular mice had higher food intake and higher energy output when fed either chow or a high-fat diet for 15 weeks compared to WT mice. Transgenic mice also matched their rate of fat oxidation to the rate of fat consumed better than WT mice. Surprisingly, when given a choice between high-fat diet and Ensure® drink, transgenic mice consumed relatively more calories from Ensure® than from the high-fat diet despite similar caloric intake to WT mice. When switching back and forth between diets, transgenic mice adjusted their intake more rapidly than WT to restore normal caloric intake. Our results show that mice with myostatin inhibition in muscle are better at adjusting energy intake and output on diets of different macronutrient composition than WT mice to maintain energy balance and resist weight gain.

  13. An overview of mice models: a key for understanding subtypes of mania

    Directory of Open Access Journals (Sweden)

    Jorge Mauricio Cuartas Arias

    2016-09-01

    Full Text Available Animal models have been broadly used in the study of pathophysiology and molecular and neurochemical pathways in neuropsychiatric diseases. Different approaches have used both consanguineous and non-consanguineous mice models to model behavioral patterns associated with the maniac spectrum. However, the disadvantages of validating clinical and experimental protocols have hindered the replication of these studies. In this article, the advantages and disadvantages of using consanguineous lines and non-consanguineous stocks in mice animal models for the study of mania and its subtypes are discussed. Additionally, new experimental alternatives to advance the pathogenesis and pharmacogenetics of mania using animal models are proposed and analyzed.

  14. Modelling anaerobic digestion in an industrial biogas digester: Application of lactate-including ADM1 model (Part II).

    Science.gov (United States)

    Satpathy, Preseela; Biernacki, Piotr; Cypionka, Heribert; Steinigeweg, Sven

    2016-12-05

    A modified Anaerobic Digestion Model No. 1 (ADM1xp) including lactate was applied to a full-scale biogas plant. This model considers monosaccharides to degrade through lactic acid, which further degrades majorly into acetate followed by propionate and butyrate. Experimental data were derived from the previous works in the same laboratory, and the proposed parameters were validated against batch experiments. After successful validation, the biogas plant bearing a fermenter size of 7 dam(3) and operated with food waste and cattle manure was simulated. The biogas production and methane content were reliably simulated, and a good fit could be obtained against the experimental data with an average difference of less than 1%. When compared to the original ADM1 model, the performance of the lactate-incorporated model was found to be improved. Inclusion of lactate as a parameter in the ADM1xp model is recommended for an increased sensitivity and enhanced prediction principally for systems dealing with high carbohydrate and lactate loads.

  15. Osteoprotegerin-deficient male mice as a model for severe alveolar bone loss: comparison with RANKL-overexpressing transgenic male mice.

    Science.gov (United States)

    Koide, Masanori; Kobayashi, Yasuhiro; Ninomiya, Tadashi; Nakamura, Midori; Yasuda, Hisataka; Arai, Yoshinori; Okahashi, Nobuo; Yoshinari, Nobuo; Takahashi, Naoyuki; Udagawa, Nobuyuki

    2013-02-01

    Periodontitis, an inflammatory disease of periodontal tissues, is characterized by excessive alveolar bone resorption. An increase in the receptor activator of nuclear factor-κB ligand (RANKL) to osteoprotegerin (OPG) ratio is thought to reflect the severity of periodontitis. Here, we examined alveolar bone loss in OPG-deficient (OPG(-/-)) mice and RANKL-overexpressing transgenic (RANKL-Tg) mice. Alveolar bone loss in OPG(-/-) mice at 12 weeks was significantly higher than that in RANKL-Tg mice. OPG(-/-) but not RANKL-Tg mice exhibited severe bone resorption especially in cortical areas of the alveolar bone. An increased number of osteoclasts was observed in the cortical areas in OPG(-/-) but not in RANKL-Tg mice. Immunohistochemical analyses showed many OPG-positive signals in osteocytes but not osteoblasts. OPG-positive osteocytes in the cortical area of alveolar bones and long bones were abundant in both wild-type and RANKL-Tg mice. This suggests the resorption in cortical bone areas to be prevented by OPG produced locally. To test the usefulness of OPG(-/-) mice as an animal model for screening drugs to prevent alveolar bone loss, we administered an antimouse RANKL antibody or risedronate, a bisphosphonate, to OPG(-/-) mice. They suppressed alveolar bone resorption effectively. OPG(-/-) mice are useful for screening therapeutic agents against alveolar bone loss.

  16. Numerical modelling of seawater intrusion in Shenzhen (China) using a 3D densitydependent model including tidal effects

    Indian Academy of Sciences (India)

    Wei Lu; Qingchun Yang; Jordi D Martín; Ricardo Juncosa

    2013-04-01

    During the 1990s, groundwater overexploitation has resulted in seawater intrusion in the coastal aquifer of the Shenzhen city, China. Although water supply facilities have been improved and alleviated seawater intrusion in recent years, groundwater overexploitation is still of great concern in some local areas. In this work we present a three-dimensional density-dependent numerical model developed with the FEFLOW code, which is aimed at simulating the extent of seawater intrusion while including tidal effects and different groundwater pumping scenarios. Model calibration, using waterheads and reported chloride concentration, has been performed based on the data from 14 boreholes, which were monitored from May 2008 to December 2009. A fairly good fitness between the observed and computed values was obtained by a manual trial-and-error method. Model prediction has been carried out forward 3 years with the calibrated model taking into account high, medium and low tide levels and different groundwater exploitation schemes. The model results show that tide-induced seawater intrusion significantly affects the groundwater levels and concentrations near the estuarine of the Dasha river, which implies that an important hydraulic connection exists between this river and groundwater, even considering that some anti-seepage measures were taken in the river bed. Two pumping scenarios were considered in the calibrated model in order to predict the future changes in the water levels and chloride concentration. The numerical results reveal a decreased tendency of seawater intrusion if groundwater exploitation does not reach an upper bound of about 1.32 × 104 m3/d. The model results provide also insights for controlling seawater intrusion in such coastal aquifer systems.

  17. Ts1Cje Down syndrome model mice exhibit environmental stimuli-triggered locomotor hyperactivity and sociability concurrent with increased flux through central dopamine and serotonin metabolism.

    Science.gov (United States)

    Shimohata, Atsushi; Ishihara, Keiichi; Hattori, Satoko; Miyamoto, Hiroyuki; Morishita, Hiromasa; Ornthanalai, Guy; Raveau, Matthieu; Ebrahim, Abdul Shukkur; Amano, Kenji; Yamada, Kazuyuki; Sago, Haruhiko; Akiba, Satoshi; Mataga, Nobuko; Murphy, Niall P; Miyakawa, Tsuyoshi; Yamakawa, Kazuhiro

    2017-07-01

    Ts1Cje mice have a segmental trisomy of chromosome 16 that is orthologous to human chromosome 21 and display Down syndrome-like cognitive impairments. Despite the occurrence of affective and emotional impairments in patients with Down syndrome, these parameters are poorly documented in Down syndrome mouse models, including Ts1Cje mice. Here, we conducted comprehensive behavioral analyses, including anxiety-, sociability-, and depression-related tasks, and biochemical analyses of monoamines and their metabolites in Ts1Cje mice. Ts1Cje mice showed enhanced locomotor activity in novel environments and increased social contact with unfamiliar partners when compared with wild-type littermates, but a significantly lower activity in familiar environments. Ts1Cje mice also exhibited some signs of decreased depression like-behavior. Furthermore, Ts1Cje mice showed monoamine abnormalities, including increased extracellular dopamine and serotonin, and enhanced catabolism in the striatum and ventral forebrain. This study constitutes the first report of deviated monoamine metabolism that may help explain the basis for abnormal behaviors, including the environmental stimuli-triggered hyperactivity, increased sociability and decreased depression-like behavior in Ts1Cje mice. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. ETM documentation update – including modelling conventions and manual for software tools

    DEFF Research Database (Denmark)

    Grohnheit, Poul Erik

    , it summarises the work done during 2013, and it also contains presentations for promotion of fusion as a future element in the electricity generation mix and presentations for the modelling community concerning model development and model documentation – in particular for TIAM collaboration workshops....

  19. Modelling stress-dependent permeability in fractured rock including effects of propagating and bending fractures

    NARCIS (Netherlands)

    Latham, J.P.; Xiang, J.; Belayneh, M.; Nick, H.M.; Tsang, C.F.; Blunt, M.J.

    2013-01-01

    The influence of in-situ stresses on flow processes in fractured rock is investigated using a novel modelling approach. The combined finite-discrete element method (FEMDEM) is used to model the deformation of a fractured rock mass. The fracture wall displacements and aperture changes are modelled in

  20. A sub-circuit MOSFET model with a wide temperature range including cryogenic temperature*

    Institute of Scientific and Technical Information of China (English)

    Jia Kan; Sun Weifeng; Shi Longxing

    2011-01-01

    A sub-circuit SPICE model ofa MOSFET for low temperature operation is presented. Two resistors are introduced for the freeze-out effect, and the explicit behavioral models are developed for them. The model can be used in a wide temperature range covering both cryogenic temperature and regular temperatures.

  1. Including Overweight or Obese Students in Physical Education: A Social Ecological Constraint Model

    Science.gov (United States)

    Li, Weidong; Rukavina, Paul

    2012-01-01

    In this review, we propose a social ecological constraint model to study inclusion of overweight or obese students in physical education by integrating key concepts and assumptions from ecological constraint theory in motor development and social ecological models in health promotion and behavior. The social ecological constraint model proposes…

  2. Effects of chronic doxepin and amitriptyline administration in naïve mice and in neuropathic pain mice model.

    Science.gov (United States)

    Mika, J; Jurga, A M; Starnowska, J; Wasylewski, M; Rojewska, E; Makuch, W; Kwiatkowski, K; Malek, N; Przewlocka, B

    2015-05-21

    Neuropathic pain is a severe clinical problem, often appearing as a co-symptom of many diseases or manifesting as a result of damage to the nervous system. Many drugs and agents are currently used for the treatment of neuropathic pain, such as tricyclic antidepressants (TCAs). The aims of this paper were to test the effects of two classic TCAs, doxepin and amitriptyline, in naïve animals and in a model of neuropathic pain and to determine the role of cytokine activation in the effects of these drugs. All experiments were carried out with Albino-Swiss mice using behavioral tests (von Frey test and the cold plate test) and biochemical analyses (qRT-PCR and Western blot). In the mice subjected to chronic constriction injury (CCI), doxepin and amitriptyline attenuated the symptoms of neuropathic pain and diminished the CCI-induced increase in the levels of spinal interleukin (IL)-6 and -1β mRNA, but not the protein levels of these cytokines, measured on day 12. Unexpectedly, chronic administration of doxepin or amitriptyline for 12 days produced allodynia and hyperalgesia in naïve mice. The treatment with these drugs did not influence the spinal levels of IL-1β and IL-6 mRNA, however, the protein levels of these pronociceptive factors were increased. The administration of ondansetron (5-HT3 receptor antagonist) significantly weakened the allodynia and hyperalgesia induced by both antidepressants in naïve mice; in contrast, yohimbine (α2-adrenergic receptors antagonist) did not influence these effects. Allodynia and hyperalgesia induced in naïve animals by amitriptyline and doxepin may be associated with an increase in the levels of pronociceptive cytokines resulting from 5-HT3-induced hypersensitivity. Our results provide new and important information about the possible side effects of antidepressants. Further investigation of these mechanisms may help to guide decisions about the use of classic TCAs for therapy.

  3. A methodology for including wall roughness effects in k-ε low-Reynolds turbulence models

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosini, W., E-mail: walter.ambrosini@ing.unipi.it; Pucciarelli, A.; Borroni, I.

    2015-05-15

    Highlights: • A model for taking into account wall roughness in low-Reynolds k-ε models is presented. • The model is subjected to a first validation to show its potential in general applications. • The application of the model in predicting heat transfer to supercritical fluids is also discussed. - Abstract: A model accounting for wall roughness effects in k-ε low-Reynolds turbulence models is described in the present paper. In particular, the introduction in the transport equations of k and ε of additional source terms related to roughness, based on simple assumptions and dimensional relationships, is proposed. An objective of the present paper, in addition to obtaining more realistic predictions of wall friction, is the application of the proposed model to the study of heat transfer to supercritical fluids. A first validation of the model is reported. The model shows the capability of predicting, at least qualitatively, some of the most important trends observed when dealing with rough pipes in very different flow conditions. Qualitative comparisons with some DNS data available in literature are also performed. Further analyses provided promising results concerning the ability of the model in reproducing the trend of friction factor when varying the flow conditions, though improvements are necessary for achieving better quantitative accuracy. First applications of the model in simulating heat transfer to supercritical fluids are also described, showing the capability of the model to affect the predictions of these heat transfer phenomena, in particular in the vicinity of the pseudo-critical conditions. A more extended application of the model to relevant deteriorated heat transfer conditions will clarify the usefulness of this modelling methodology in improving predictions of these difficult phenomena. Whatever the possible success in this particular application that motivated its development, this approach suggests a general methodology for accounting

  4. Partial Enteral Nutrition Preserves Elements of Gut Barrier Function, Including Innate Immunity, Intestinal Alkaline Phosphatase (IAP) Level, and Intestinal Microbiota in Mice.

    Science.gov (United States)

    Wan, Xiao; Bi, Jingcheng; Gao, Xuejin; Tian, Feng; Wang, Xinying; Li, Ning; Li, Jieshou

    2015-08-03

    Lack of enteral nutrition (EN) during parenteral nutrition (PN) leads to higher incidence of infection because of gut barrier dysfunction. However, the effects of partial EN on intestina linnate immunity, intestinal alkaline phosphatase (IAP) and microbiota remain unclear. The mice were randomized into six groups to receive either standard chow or isocaloric and isonitrogenous nutritional support with variable partial EN to PN ratios. Five days later, the mice were sacrificed and tissue samples were collected. Bacterial translocation, the levels of lysozyme, mucin 2 (MUC2), and IAP were analyzed. The composition of intestinal microbiota was analyzed by 16S rRNA pyrosequencing. Compared with chow, total parenteral nutrition (TPN) resulted in a dysfunctional mucosal barrier, as evidenced by increased bacterial translocation (p microbiota (p intestinal microbiota.

  5. Protective effects of white button mushroom (Agaricus bisporus against hepatic steatosis in ovariectomized mice as a model of postmenopausal women.

    Directory of Open Access Journals (Sweden)

    Noriko Kanaya

    Full Text Available Nonalcoholic fatty liver disease (NAFLD includes various hepatic pathologies ranging from hepatic steatosis to non-alcoholic steatohepatitis (NASH, fibrosis and cirrhosis. Estrogen provides a protective effect on the development of NAFLD in women. Therefore, postmenopausal women have a higher risk of developing NAFLD. Hepatic steatosis is an early stage of fatty liver disease. Steatosis can develop to the aggressive stages (nonalcoholic steatohepatitis, fibrosis and cirrhosis. Currently, there is no specific drug to prevent/treat these liver diseases. In this study, we found that white button mushroom (WBM, Agaricus Bisporus, has protective effects against liver steatosis in ovariectomized (OVX mice (a model of postmenopausal women. OVX mice were fed a high fat diet supplemented with WBM powder. We found that dietary WBM intake significantly lowered liver weight and hepatic injury markers in OVX mice. Pathological examination of liver tissue showed less fat accumulation in the livers of mice on WBM diet; moreover, these animals had improved glucose clearance ability. Microarray analysis revealed that genes related to the fatty acid biosynthesis pathway, particularly the genes for fatty acid synthetase (Fas and fatty acid elongase 6 (Elovl6, were down-regulated in the liver of mushroom-fed mice. In vitro mechanistic studies using the HepG2 cell line showed that down-regulation of the expression of FAS and ELOVL6 by WBM extract was through inhibition of Liver X receptor (LXR signaling and its downstream transcriptional factor SREBP1c. These results suggest that WBM is protective against hepatic steatosis and NAFLD in OVX mice as a model for postmenopausal women.

  6. Persistent Coxiella burnetii infection in mice overexpressing IL-10: an efficient model for chronic Q fever pathogenesis.

    Directory of Open Access Journals (Sweden)

    Soraya Meghari

    2008-02-01

    Full Text Available Interleukin (IL-10 increases host susceptibility to microorganisms and is involved in intracellular persistence of bacterial pathogens. IL-10 is associated with chronic Q fever, an infectious disease due to the intracellular bacterium Coxiella burnetii. Nevertheless, accurate animal models of chronic C. burnetii infection are lacking. Transgenic mice constitutively expressing IL-10 in macrophages were infected with C. burnetti by intraperitoneal and intratracheal routes and infection was analyzed through real-time PCR and antibody production. Transgenic mice exhibited sustained tissue infection and strong antibody response in contrast to wild-type mice; thus, bacterial persistence was IL-10-dependent as in chronic Q fever. The number of granulomas was low in spleen and liver of transgenic mice infected through the intraperitoneal route, as in patients with chronic Q fever. Macrophages from transgenic mice were unable to kill C. burnetii. C. burnetii-stimulated macrophages were characterized by non-microbicidal transcriptional program consisting of increased expression of arginase-1, mannose receptor, and Ym1/2, in contrast to wild-type macrophages in which expression of inducible NO synthase and inflammatory cytokines was increased. In vivo results emphasized macrophage data. In spleen and liver of transgenic mice infected with C. burnetii by the intraperitoneal route, the expression of arginase-1 was increased while microbicidal pathway consisting of IL-12p40, IL-23p19, and inducible NO synthase was depressed. The overexpression of IL-10 in macrophages prevents anti-infectious competence of host, including the ability to mount granulomatous response and microbicidal pathway in tissues. To our knowledge, this is the first efficient model for chronic Q fever pathogenesis.

  7. Ultrastructural characterization of the mesostriatal dopamine innervation in mice, including two mouse lines of conditional VGLUT2 knockout in dopamine neurons.

    Science.gov (United States)

    Bérubé-Carrière, Noémie; Guay, Ginette; Fortin, Guillaume M; Kullander, Klas; Olson, Lars; Wallén-Mackenzie, Åsa; Trudeau, Louis-Eric; Descarries, Laurent

    2012-02-01

    Despite the increasing use of genetically modified mice to investigate the dopamine (DA) system, little is known about the ultrastructural features of the striatal DA innervation in the mouse. This issue is particularly relevant in view of recent evidence for expression of the vesicular glutamate transporter 2 (VGLUT2) by a subset of mesencephalic DA neurons in mouse as well as rat. We used immuno-electron microscopy to characterize tyrosine hydroxylase (TH)-labeled terminals in the core and shell of nucleus accumbens and the neostriatum of two mouse lines in which the Vglut2 gene was selectively disrupted in DA neurons (cKO), their control littermates, and C57BL/6/J wild-type mice, aged P15 or adult. The three regions were also examined in cKO mice and their controls of both ages after dual TH-VGLUT2 immunolabeling. Irrespective of the region, age and genotype, the TH-immunoreactive varicosities appeared similar in size, vesicular content, percentage with mitochondria, and exceedingly low frequency of synaptic membrane specialization. No dually labeled axon terminals were found at either age in control or in cKO mice. Unless TH and VGLUT2 are segregated in different axon terminals of the same neurons, these results favor the view that the glutamatergic cophenotype of mesencephalic DA neurons is more important during the early development of these neurons than for the establishment of their scarce synaptic connectivity. They also suggest that, in mouse even more than rat, the mesostriatal DA system operates mainly through non-targeted release of DA, diffuse transmission and the maintenance of an ambient DA level.

  8. Loss of neprilysin alters protein expression in the brain of Alzheimer's disease model mice.

    Science.gov (United States)

    Nilsson, Per; Loganathan, Krishnapriya; Sekiguchi, Misaki; Winblad, Bengt; Iwata, Nobuhisa; Saido, Takaomi C; Tjernberg, Lars O

    2015-10-01

    Alzheimer's disease (AD) is a neurodegenerative disease displaying extracellular plaques formed by the neurotoxic amyloid β-peptide (Aβ), and intracellular neurofibrillary tangles consisting of protein tau. However, how these pathologies relate to the massive neuronal death that occurs in AD brains remain elusive. Neprilysin is the major Aβ-degrading enzyme and a lack thereof increases Aβ levels in the brain twofold. To identify altered protein expression levels induced by increased Aβ levels, we performed a proteomic analysis of the brain of the AD mouse model APPsw and compared it to that of APPsw mice lacking neprilysin. To this end we established an LC-MS/MS method to analyze brain homogenate, using an (18) O-labeled internal standard to accurately quantify the protein levels. To distinguish between alterations in protein levels caused by increased Aβ levels and those induced by neprilysin deficiency independently of Aβ, the brain proteome of neprilysin deficient APPsw mice was also compared to that of neprilysin deficient mice. By this approach we identified approximately 600 proteins and the levels of 300 of these were quantified. Pathway analysis showed that many of the proteins with altered expression were involved in neurological disorders, and that tau, presenilin and APP were key regulators in the identified networks. The data have been deposited to the ProteomeXchange Consortium with identifiers PXD000968 and PXD001786 (http://proteomecentral.proteomexchange.org/dataset/PXD000968 and (http://proteomecentral.proteomexchange.org/dataset/PXD001786). Interestingly, the levels of several proteins, including some not previously reported to be linked to AD, were associated with increased Aβ levels. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Topical Treatment of Dermatophytic Lesion on Mice (Mus musculus) Model.

    Science.gov (United States)

    Sharma, Bindu; Kumar, Padma; Joshi, Suresh Chandra

    2011-06-01

    Antidermatophytic potential of three weed plants viz. Tridax procumbens L., Capparis decidua (forsk) Edgew and Lantana camara L. were explored and experimentally induced dermatophytic lesion was topically treated in mice. Microbroth dilution method was carried out for determination of MIC and MFC of different extracts of selected plants. In animal studies, mice were experimentally inoculated with Trichophyton mentagrophytes and infected animals were topically treated with 5 mg/g terbinafine and two concentrations, i.e., 5 and 10 mg/g of test extract ointment. Complete recovery from the infection was observed on 12th day of treatment for reference drug terbinafine (5 mg/g) and 10 mg/g concentration of test extract ointment whereas 5 mg/g concentration of test extract ointment showed complete cure on 16th day of treatment. Fungal burden was also calculated by culturing skin scrapings from infected animals of different groups. Test extract ointment successfully treated induced dermatophytosis in mice without any disease recurrence incidences, thereby indicating efficacy of test extract as an excellent topical antifungal agent for the cure of dermatophytosis.

  10. Craniosynostosis in Twist heterozygous mice: a model for Saethre-Chotzen syndrome.

    Science.gov (United States)

    Carver, Ethan A; Oram, Kathleen F; Gridley, Thomas

    2002-10-01

    Saethre-Chotzen syndrome is a common autosomal dominant form of craniosynostosis, the premature fusion of the sutures of the calvarial bones of the skull. Most Saethre-Chotzen syndrome cases are caused by haploinsufficiency for the TWIST gene. Mice heterozygous for a null mutation of the Twist gene replicate certain features of Saethre-Chotzen syndrome, but have not been reported to exhibit craniosynostosis. We demonstrate that Twist heterozygous mice exhibit fusions of the coronal suture and other cranial suture abnormalities, indicating that Twist heterozygous mice constitute a better animal model for Saethre-Chotzen syndrome than was previously appreciated.

  11. Induction of animal model of Graves disease in BALB/c mice

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective To construct an animal model of Graves' disease(GD)by immunizing BALB/c mice with hM12 cells co-expressing major histocompatibility complex(MHC)class II molecules and human thyrotropin receptor(TSHR)molecules.Methods BALB/c mice in experimental group(H-2d)were immunized with hM12 cells intraperitoneally every 2 weeks for six times,while mice in control group were immunized with M12 cells.Five weeks later,the thyroids were histologically examined,and serum samples were tested for thyroid-stimulatin...

  12. Two methods for modeling vibrations of planetary gearboxes including faults: Comparison and validation

    Science.gov (United States)

    Parra, J.; Vicuña, Cristián Molina

    2017-08-01

    Planetary gearboxes are important components of many industrial applications. Vibration analysis can increase their lifetime and prevent expensive repair and safety concerns. However, an effective analysis is only possible if the vibration features of planetary gearboxes are properly understood. In this paper, models are used to study the frequency content of planetary gearbox vibrations under non-fault and different fault conditions. Two different models are considered: phenomenological model, which is an analytical-mathematical formulation based on observation, and lumped-parameter model, which is based on the solution of the equations of motion of the system. Results of both models are not directly comparable, because the phenomenological model provides the vibration on a fixed radial direction, such as the measurements of the vibration sensor mounted on the outer part of the ring gear. On the other hand, the lumped-parameter model provides the vibrations on the basis of a rotating reference frame fixed to the carrier. To overcome this situation, a function to decompose the lumped-parameter model solutions to a fixed reference frame is presented. Finally, comparisons of results from both model perspectives and experimental measurements are presented.

  13. Astaxanthin improves behavioral disorder and oxidative stress in prenatal valproic acid-induced mice model of autism.

    Science.gov (United States)

    Al-Amin, Md Mamun; Rahman, Md Mahbubur; Khan, Fazlur Rahman; Zaman, Fahmida; Mahmud Reza, Hasan

    2015-06-01

    Prenatal exposure to valproic acid on gestational day 12.5 may lead to the impaired behavior in the offspring, which is similar to the human autistic symptoms. To the contrary, astaxanthin shows neuroprotective effect by its antioxidant mechanism. We aimed to (i) develop mice model of autism and (ii) investigate the effect of astaxanthin on such model animals. Valproic acid (600 mg/kg) was administered intraperitoneally to the pregnant mice on gestational day 12.5. Prenatal valproic acid-exposed mice were divided into 2 groups on postnatal day 25 and astaxanthin (2mg/kg) was given to the experimental group (VPA_AST, n=10) while saline was given to the control group (VPA, n=10) for 4 weeks. Behavioral test including social interaction, open field and hot-plate were conducted on postnatal day 25 and oxidative stress markers such as lipid peroxidation, advanced protein oxidation product, nitric oxide, glutathione, and activity of superoxide dismutase and catalase were estimated on postnatal day 26 to confirm mice model of autism and on postnatal day 56 to assess the effect of astaxanthin. On postnatal day 25, prenatal valproic acid-exposed mice exhibited (i) delayed eye opening (ii) longer latency to respond painful stimuli, (iii) poor sociability and social novelty and (iv) high level of anxiety. In addition, an increased level of oxidative stress was found by determining different oxidative stress markers. Treatment with astaxanthin significantly (pAstaxanthin improves the impaired behavior in animal model of autism presumably by its antioxidant activity.

  14. BDNF-restricted knockout mice as an animal model for aggression.

    Science.gov (United States)

    Ito, W; Chehab, M; Thakur, S; Li, J; Morozov, A

    2011-04-01

    Mice with global deletion of one brain-derived neurotrophic factor (BDNF) allele or with forebrain-restricted deletion of both alleles show elevated aggression, but this phenotype is accompanied by other behavioral changes, including increases in anxiety and deficits in cognition. Here we performed behavioral characterization of conditional BDNF knockout mice generated using a Cre recombinase driver line, KA1-Cre, which expresses Cre in few areas of brain: highly at hippocampal area CA3 and moderately in dentate gyrus, cerebellum and facial nerve nucleus. The mutant animals exhibited elevated conspecific aggression and social dominance, but did not show changes in anxiety-like behaviors assessed using the elevated plus maze and open field test. There were no changes in depression-like behaviors tested in the forced swim test, but small increase in immobility in the tail suspension test. In cognitive tasks, mutants showed normal social recognition and normal spatial and fear memory, but exhibited a deficit in object recognition. Thus, this knockout can serve as a robust model for BDNF-dependent aggression and object recognition deficiency.

  15. Efficacy of Sustained-Release Buprenorphine in an Experimental Laparotomy Model in Female Mice.

    Science.gov (United States)

    Kendall, Lon V; Wegenast, Daniel J; Smith, Brian J; Dorsey, Kathryn M; Kang, Sooah; Lee, Na Young; Hess, Ann M

    2016-01-01

    Mice purportedly require dosing with the opioid buprenorphine (Bup-HCl) at least every 8 to 12 h to maintain an adequate plane of analgesia. Here we used an experimental laparotomy model to determine the clinical efficacy of sustained-release formulations of buprenorphine (Bup-SR) after surgery in mice. Female CD1 mice underwent laparotomy and received either Bup-SR (0.6 mg/kg), Bup-HCl (0.1 mg/kg every 12 h), or saline (every 12 h). Pain was assessed at 1, 3, 6, 12, 24, 48, and 72 h according to the frequency of several behaviors (general activity, wheel-running activity, rearing, grooming, wound licking, orbital tightening, and percentage of integrated nest material) and daily body weight. Over time, wheel running was increased and wound licking was decreased in Bup-SR-treated mice compared with Bup-HCl- and saline-treated mice. Compared with Bup-HCl- and saline-treated mice, Bup-SR-treated mice had increased general activity and percentage of integrated nest material and decreased orbital tightening for 1 to 6 h after surgery. The Bup-HCl- and saline-treated mice had similar general activity, orbital tightening scores, and wheel running activity. Rearing activity and body weight did not differ throughout the study, and none of the observed behaviors differed between groups at 24, 48, and 72 h after surgery. These results suggest that Bup-SR at 0.6 mg/kg provides adequate analgesia after laparotomy in mice and can be used as an alternative analgesic in this context. Furthermore, Bup-HCl at 0.1 mg/kg every 12 h may be inadequate in providing analgesia for abdominal procedures in mice.

  16. A two-dimensional simulation model of phosphorus uptake including crop growth and P-response

    NARCIS (Netherlands)

    Mollier, A.; Willigen, de P.; Heinen, M.; Morel, C.; Schneider, A.; Pellerin, S.

    2008-01-01

    Modelling nutrient uptake by crops implies considering and integrating the processes controlling the soil nutrient supply, the uptake by the root system and relationships between the crop growth response and the amount of nutrient absorbed. We developed a model that integrates both dynamics of maize

  17. European column buckling curves and finite element modelling including high strength steels

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Stan, Tudor-Cristian

    2017-01-01

    Eurocode allows for finite element modelling of plated steel structures, however the information in the code on how to perform the analysis or what assumptions to make is quite sparse. The present paper investigates the deterministic modelling of flexural column buckling using plane shell element...

  18. Dipole model analysis of highest precision HERA data, including very low $Q^2$'s

    CERN Document Server

    Luszczak, Agnieszka

    2016-01-01

    We analyse, within a dipole model, the final, inclusive HERA DIS cross section data in the low $x$ region, using fully correlated errors. We show, that these highest precision data are very well described within the dipole model framework starting from $Q^2$ values of 3.5 GeV$^2$ to the highest values of $Q^2 =$ 250 GeV$^2$.

  19. A Two-Account Life Insurance Model for Scenario-Based Valuation Including Event Risk

    DEFF Research Database (Denmark)

    Jensen, Ninna Reitzel; Schomacker, Kristian Juul

    2015-01-01

    Using a two-account model with event risk, we model life insurance contracts taking into account both guaranteed and non-guaranteed payments in participating life insurance as well as in unit-linked insurance. Here, event risk is used as a generic term for life insurance events, such as death......, disability, etc. In our treatment of participating life insurance, we have special focus on the bonus schemes “consolidation” and “additional benefits”, and one goal is to formalize how these work and interact. Another goal is to describe similarities and differences between participating life insurance...... model by conducting scenario analysis based on Monte Carlo simulation, but the model applies to scenarios in general and to worst-case and best-estimate scenarios in particular. In addition to easy computations, our model offers a common framework for the valuation of life insurance payments across...

  20. A Two-Account Life Insurance Model for Scenario-Based Valuation Including Event Risk

    DEFF Research Database (Denmark)

    Jensen, Ninna Reitzel; Schomacker, Kristian Juul

    2015-01-01

    and unit-linked insurance. By use of a two-account model, we are able to illustrate general concepts without making the model too abstract. To allow for complicated financial markets without dramatically increasing the mathematical complexity, we focus on economic scenarios. We illustrate the use of our......Using a two-account model with event risk, we model life insurance contracts taking into account both guaranteed and non-guaranteed payments in participating life insurance as well as in unit-linked insurance. Here, event risk is used as a generic term for life insurance events, such as death...... product types. This enables comparison of participating life insurance products and unit-linked insurance products, thus building a bridge between the two different ways of formalizing life insurance products. Finally, our model distinguishes itself from the existing literature by taking into account...

  1. Gasification of biomass in a fixed bed downdraft gasifier--a realistic model including tar.

    Science.gov (United States)

    Barman, Niladri Sekhar; Ghosh, Sudip; De, Sudipta

    2012-03-01

    This study presents a model for fixed bed downdraft biomass gasifiers considering tar also as one of the gasification products. A representative tar composition along with its mole fractions, as available in the literature was used as an input parameter within the model. The study used an equilibrium approach for the applicable gasification reactions and also considered possible deviations from equilibrium to further upgrade the equilibrium model to validate a range of reported experimental results. Heat balance was applied to predict the gasification temperature and the predicted values were compared with reported results in literature. A comparative study was made with some reference models available in the literature and also with experimental results reported in the literature. Finally a predicted variation of performance of the gasifier by this validated model for different air-fuel ratio and moisture content was also discussed.

  2. Mice with human immune system components as in vivo models for infections with human pathogens

    OpenAIRE

    Rämer, P C; Chijioke, O; Meixlsperger, S; Leung, C S; Münz, C.

    2011-01-01

    Many pathogens relevant to human disease do not infect other animal species. Therefore, animal models that reconstitute or harbour human tissues are explored as hosts for these. In this review, we will summarize recent advances to utilize mice with human immune system components, reconstituted from hematopoietic progenitor cells in vivo. Such mice can be used to study human pathogens that replicate in leucocytes. In addition to studying the replication of these pathogens, the reconstituted hu...

  3. Including Tropical Croplands in a Terrestrial Biosphere Model: Application to West Africa

    Science.gov (United States)

    Berg, A.; Sultan, B.; de Noblet, N.

    2008-12-01

    Studying the large-scale relationships between climate and agriculture raises two different issues: the impact of climate on crops, and the potential feedbacks to climate from croplands. A relevant framework to consistently address this twofold issue is to extend existing Dynamic Global Vegetation Models, which can be coupled to climate models, in order to explicitly account for croplands. Here we present the first results of such a strategy applied to tropical croplands over West Africa. We introduce directly into the terrestrial biosphere model ORCHIDEE (IPSL) adequate processes and parametrizations taken from the crop model SARRAH (CIRAD), which is calibrated for millet over this region. The resulting model, ORCH-mil, realistically simulates the growth and yield of millet when tested on an experimental station in Senegal. The model is then applied over West Africa using a 36-year climate reanalysis dataset. First the model is tested in terms of yield simulation, against national millet yields from the FAO database. The ability of the model to reproduce the spatial and temporal variability of millet yields is assessed. Then, the effects on land surface fluxes of explicitly accounting for croplands are examined, by comparison between ORCH-mil and ORCHIDEE. These first simulations show consistent results, but underline the need for some further development and validation of the model if it is to simulate yields accurately. In terms of land surface fluxes, significant differences between ORCH-mil and ORCHIDEE appear, mainly via changes in evaporation and albedo. The potential impact on the west African monsoon system of such differences needs to be investigated by coupling ORCH-mil to a climate model: first results from such an experiment will be presented.

  4. Spatial modelling of marine organisms in Forsmark and Oskarshamn. Including calculation of physical predictor variables

    Energy Technology Data Exchange (ETDEWEB)

    Carlen, Ida; Nikolopoulos, Anna; Isaeus, Martin (AquaBiota Water Research, Stockholm (SE))

    2007-06-15

    GIS grids (maps) of marine parameters were created using point data from previous site investigations in the Forsmark and Oskarshamn areas. The proportion of global radiation reaching the sea bottom in Forsmark and Oskarshamn was calculated in ArcView, using Secchi depth measurements and the digital elevation models for the respective area. The number of days per year when the incoming light exceeds 5 MJ/m2 at the bottom was then calculated using the result of the previous calculations together with measured global radiation. Existing modelled grid-point data on bottom and pelagic temperature for Forsmark were interpolated to create surface covering grids. Bottom and pelagic temperature grids for Oskarshamn were calculated using point measurements to achieve yearly averages for a few points and then using regressions with existing grids to create new maps. Phytoplankton primary production in Forsmark was calculated using point measurements of chlorophyll and irradiance, and a regression with a modelled grid of Secchi depth. Distribution of biomass of macrophyte communities in Forsmark and Oskarshamn was calculated using spatial modelling in GRASP, based on field data from previous surveys. Physical parameters such as those described above were used as predictor variables. Distribution of biomass of different functional groups of fish in Forsmark was calculated using spatial modelling based on previous surveys and with predictor variables such as physical parameters and results from macrophyte modelling. All results are presented as maps in the report. The quality of the modelled predictions varies as a consequence of the quality and amount of the input data, the ecology and knowledge of the predicted phenomena, and by the modelling technique used. A substantial part of the variation is not described by the models, which should be expected for biological modelling. Therefore, the resulting grids should be used with caution and with this uncertainty kept in mind. All

  5. Thymol produces an antidepressant-like effect in a chronic unpredictable mild stress model of depression in mice.

    Science.gov (United States)

    Deng, Xue-Yang; Li, Hong-Yan; Chen, Jun-Jun; Li, Rui-Peng; Qu, Rong; Fu, Qiang; Ma, Shi-Ping

    2015-09-15

    Thymol, a bioactive monoterpene isolated from Thymus vulgaris, has displayed inspiring neuroprotective properties. The present study was designed to evaluate the antidepressant-like effects of thymol on a chronic unpredictable mild stress (CUMS) model of depression in mice and explore the underlying mechanisms. It was observed that thymol treatment (15 mg/kg and 30 mg/kg) significantly reversed the decrease of sucrose consumption, the loss of body weight, the reduction of immobile time in the tail suspension tests (TST) and forced swimming tests (FST) induced by CUMS paradigm. The levels of norepinephrine (NE) and serotonin (5-HT) in the hippocampus decreased in the CUMS-treated mice. Chronic treatments with thymol significantly restored the CUMS-induced alterations of monoamine neurotransmitters in the hippocampus. Our results further demonstrated that thymol administration negatively regulated the induction of proinflammatory cytokines including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α in CUMS mice. Furthermore, thymol inhibited the activation of nod-like receptor protein 3 (NLRP3) inflammasome and its adaptor, and subsequently decreased the expression of caspase-1. In sum, our findings suggested that thymol played a potential antidepressant role in CUMS mice model through up-regulating the levels of central neurotransmitters and inhibiting the expressions of proinflammatory cytokines, which might provide potential for thymol in the light of opening up new therapeutic avenues for depression.

  6. Characterization and modeling of intermittent locomotor dynamics in clock gene-deficient mice.

    Directory of Open Access Journals (Sweden)

    Toru Nakamura

    Full Text Available The scale-invariant and intermittent dynamics of animal behavior are attracting scientific interest. Recent findings concerning the statistical laws of behavioral organization shared between healthy humans and wild-type mice (WT and their alterations in human depression patients and circadian clock gene (Period 2; Per2 mutant mice indicate that clock genes play functional roles in intermittent, ultradian locomotor dynamics. They also claim the clinical and biological importance of the laws as objective biobehavioral measures or endophenotypes for psychiatric disorders. In this study, to elucidate the roles of breakdown of the broader circadian regulatory circuit in intermittent behavioral dynamics, we studied the statistical properties and rhythmicity of locomotor activity in Per2 mutants and mice deficient in other clock genes (Bmal1, Clock. We performed wavelet analysis to examine circadian and ultradian rhythms and estimated the cumulative distributions of resting period durations during which locomotor activity levels are continuously lower than a predefined threshold value. The wavelet analysis revealed significant amplification of ultradian rhythms in the BMAL1-deficient mice, and instability in the Per2 mutants. The resting period distributions followed a power-law form in all mice. While the distributions for the BMAL1-deficient and Clock mutant mice were almost identical to those for the WT mice, with no significant differences in their parameter (power-law scaling exponent, only the Per2 mutant mice showed consistently and significantly lower values of the scaling exponent, indicating the increased intermittency in ultradian locomotor dynamics. Furthermore, based on a stochastic priority queuing model, we explained the power-law nature of resting period distributions, as well as its alterations shared with human depressive patients and Per2 mutant mice. Our findings lead to the development of a novel mathematical model for abnormal

  7. Eya4-deficient mice are a model for heritable otitis media

    OpenAIRE

    2008-01-01

    Otitis media is an extremely common pediatric inflammation of the middle ear that often causes pain and diminishes hearing. Vulnerability to otitis media is due to eustachian tube dysfunction as well as other poorly understood factors, including genetic susceptibility. As EYA4 mutations cause sensorineural hearing loss in humans, we produced and characterized Eya4-deficient (Eya4–/–) mice, which had severe hearing deficits. In addition, all Eya4–/– mice developed otitis media with effusion. A...

  8. Modeled hydraulic redistribution by Helianthus annuus L. matches observed data only after model modification to include nighttime transpiration

    Science.gov (United States)

    Neumann, R. B.; Cardon, Z. G.; Rockwell, F. E.; Teshera-Levye, J.; Zwieniecki, M.; Holbrook, N. M.

    2013-12-01

    The movement of water from moist to dry soil layers through the root systems of plants, referred to as hydraulic redistribution (HR), occurs throughout the world and is thought to influence carbon and water budgets and ecosystem functioning. The realized hydrologic, biogeochemical, and ecological consequences of HR depend on the amount of redistributed water, while the ability to assess these impacts requires models that correctly capture HR magnitude and timing. Using several soil types and two eco-types of Helianthus annuus L. in split-pot experiments, we examined how well the widely used HR modeling formulation developed by Ryel et al. (2002) could match experimental determination of HR across a range of water potential driving gradients. H. annuus carries out extensive nighttime transpiration, and though over the last decade it has become more widely recognized that nighttime transpiration occurs in multiple species and many ecosystems, the original Ryel et al. (2002) formulation does not include the effect of nighttime transpiration on HR. We developed and added a representation of nighttime transpiration into the formulation, and only then was the model able to capture the dynamics and magnitude of HR we observed as soils dried and nighttime stomatal behavior changed, both influencing HR.

  9. Understanding Experimental LCMV Infection of Mice: The Role of Mathematical Models

    Directory of Open Access Journals (Sweden)

    Gennady Bocharov

    2015-01-01

    Full Text Available Virus infections represent complex biological systems governed by multiple-level regulatory processes of virus replication and host immune responses. Understanding of the infection means an ability to predict the systems behaviour under various conditions. Such predictions can only rely upon quantitative mathematical models. The model formulations should be tightly linked to a fundamental step called “coordinatization” (Hermann Weyl, that is, the definition of observables, parameters, and structures that enable the link with a biological phenotype. In this review, we analyse the mathematical modelling approaches to LCMV infection in mice that resulted in quantification of some fundamental parameters of the CTL-mediated virus control including the rates of T cell turnover, infected target cell elimination, and precursor frequencies. We show how the modelling approaches can be implemented to address diverse aspects of immune system functioning under normal conditions and in response to LCMV and, importantly, make quantitative predictions of the outcomes of immune system perturbations. This may highlight the notion that data-driven applications of meaningful mathematical models in infection biology remain a challenge.

  10. Multimodal imaging of a humanized orthotopic model of hepatocellular carcinoma in immunodeficient mice

    Science.gov (United States)

    Wu, Tao; Heuillard, Emilie; Lindner, Véronique; Bou About, Ghina; Ignat, Mihaela; Dillenseger, Jean-Philippe; Anton, Nicolas; Dalimier, Eugénie; Gossé, Francine; Fouré, Gael; Blindauer, Franck; Giraudeau, Céline; El-Saghire, Hussein; Bouhadjar, Mourad; Calligaro, Cynthia; Sorg, Tania; Choquet, Philippe; Vandamme, Thierry; Ferrand, Christophe; Marescaux, Jacques; Baumert, Thomas F.; Diana, Michele; Pessaux, Patrick; Robinet, Eric

    2016-01-01

    The development of multimodal strategies for the treatment of hepatocellular carcinoma requires tractable animal models allowing for advanced in vivo imaging. Here, we characterize an orthotopic hepatocellular carcinoma model based on the injection of luciferase-expressing human hepatoma Huh-7 (Huh-7-Luc) cells in immunodeficient mice. Luciferase allows for an easy repeated monitoring of tumor growth by in vivo bioluminescence. The intrahepatic injection was more efficient than intrasplenic or intraportal injection in terms of survival, rate of orthotopic engraftment, and easiness. A positive correlation between luciferase activity and tumor size, evaluated by Magnetic Resonance Imaging, allowed to define the endpoint value for animal experimentation with this model. Response to standard of care, sorafenib or doxorubicin, were similar to those previously reported in the literature, with however a strong toxicity of doxorubicin. Tumor vascularization was visible by histology seven days after Huh-7-Luc transplantation and robustly developed at day 14 and day 21. The model was used to explore different imaging modalities, including microtomography, probe-based confocal laser endomicroscopy, full-field optical coherence tomography, and ultrasound imaging. Tumor engraftment was similar after echo-guided intrahepatic injection as after laparotomy. Collectively, this orthotopic hepatocellular carcinoma model enables the in vivo evaluation of chemotherapeutic and surgical approaches using multimodal imaging. PMID:27739457

  11. Constraints on gen4eralized Chaplygin gas model including gamma-ray bursts

    Institute of Scientific and Technical Information of China (English)

    Fa-Yin Wang; Zi-Gao Dai; Shi Qi

    2009-01-01

    Generalized Chaplygin gas (whose equation of state is PGCG = -A/PGCGα) was proposed as a candidate for unification of dark energy and dark matter. We inves-tigate constraints on this model with the latest observed data. We test the model with type-Ia supernovae (SNe Ia), cosmic microwave background (CMB) anisotropy, X-ray gas mass fractions in clusters, and gamma-ray bursts (GRBs). We calibrate the GRB lu-minosity relations without assuming any cosmological models using SNe Ia. We show that GRBs can extend the Hubble diagram to higher redshifts (z> 6). The GRB Hubble diagram is well behaved and delineates the shape of the Hubble diagram well. We mea-sure As≡A/PGCG,0α+1=0.68-0.08+0.04 (where PGCG,0 is the energy density today) and α=-0.22-0.13+0.15at the 1σconfidence level using all the datasets. Our results rule out the standard Chaplygin gas model (α = 1) at the 3a confidence level. The ACDM is allowed at the 2or confidence level. We find that acceleration could have started at a redshift of z ~ 0.70. The concordance of the generalized Chaplygin gas model with the age estimate of an old high redshift quasar is found. In addition, we show that GRBs can break the degeneracy between the generalized Chaplygin gas model and the XCDM model.

  12. Simulated village locations in Thailand: A multi-scale model including a neural network approach.

    Science.gov (United States)

    Tang, Wenwu; Malanson, George P; Entwisle, Barbara

    2009-04-01

    The simulation of rural land use systems, in general, and rural settlement dynamics in particular has developed with synergies of theory and methods for decades. Three current issues are: linking spatial patterns and processes, representing hierarchical relations across scales, and considering nonlinearity to address complex non-stationary settlement dynamics. We present a hierarchical simulation model to investigate complex rural settlement dynamics in Nang Rong, Thailand. This simulation uses sub-models to allocate new villages at three spatial scales. Regional and sub-regional models, which involve a nonlinear space-time autoregressive model implemented in a neural network approach, determine the number of new villages to be established. A dynamic village niche model, establishing pattern-process link, was designed to enable the allocation of villages into specific locations. Spatiotemporal variability in model performance indicates the pattern of village location changes as a settlement frontier advances from rice-growing lowlands to higher elevations. Experiments results demonstrate this simulation model can enhance our understanding of settlement development in Nang Rong and thus gain insight into complex land use systems in this area.

  13. A Two-Account Life Insurance Model for Scenario-Based Valuation Including Event Risk

    Directory of Open Access Journals (Sweden)

    Ninna Reitzel Jensen

    2015-06-01

    Full Text Available Using a two-account model with event risk, we model life insurance contracts taking into account both guaranteed and non-guaranteed payments in participating life insurance as well as in unit-linked insurance. Here, event risk is used as a generic term for life insurance events, such as death, disability, etc. In our treatment of participating life insurance, we have special focus on the bonus schemes “consolidation” and “additional benefits”, and one goal is to formalize how these work and interact. Another goal is to describe similarities and differences between participating life insurance and unit-linked insurance. By use of a two-account model, we are able to illustrate general concepts without making the model too abstract. To allow for complicated financial markets without dramatically increasing the mathematical complexity, we focus on economic scenarios. We illustrate the use of our model by conducting scenario analysis based on Monte Carlo simulation, but the model applies to scenarios in general and to worst-case and best-estimate scenarios in particular. In addition to easy computations, our model offers a common framework for the valuation of life insurance payments across product types. This enables comparison of participating life insurance products and unit-linked insurance products, thus building a bridge between the two different ways of formalizing life insurance products. Finally, our model distinguishes itself from the existing literature by taking into account the Markov model for the state of the policyholder and, hereby, facilitating event risk.

  14. 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.

  15. A Two-Dimensional Modeling Procedure to Estimate the Loss Equivalent Resistance Including the Saturation Effect

    Directory of Open Access Journals (Sweden)

    Rosa Ana Salas

    2013-11-01

    Full Text Available We propose a modeling procedure specifically designed for a ferrite inductor excited by a waveform in time domain. We estimate the loss resistance in the core (parameter of the electrical model of the inductor by means of a Finite Element Method in 2D which leads to significant computational advantages over the 3D model. The methodology is validated for an RM (rectangular modulus ferrite core working in the linear and the saturation regions. Excellent agreement is found between the experimental data and the computational results.

  16. Recent Advances in Study on Thermodynamic Models for Real Systems Including Electrolytes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A comprehensive review of recent advances in study on thermodynamic models for real electrolyte solutions is presented. The differences between primitive and non-primitive electrolyte models are demonstrated. Some new thermodynamic models for electrolyte solutions based on the mean spherical approximation and perturbation theory are introduced. An extended scaled-particle theory and modified CleggPitz er equation are presented for physical and chemical absorption processes with mixed solvents, respectively. A pseudo one-component two-Yukawa equation of state is used for the aqueous two-phase extraction process in charged colloidal systems.

  17. Extension of Lithium Ion Cell Model to Include Transient and Low-Temperature Behaviour

    Science.gov (United States)

    Dudley, G.

    2014-08-01

    Current-interruption resistance measurements have been analysed in detail allowing the ESTEC lithium ion cell electrical/thermal model to be extended to allow modelling of cell voltage in response to imposed current changes at low temperatures and short time scales where activation polarisation becomes important. Whilst an unnecessary complication in most cases, this extension is needed under certain circumstances such as the simulation of Mars rover batteries forced to operate at low temperature and possible effects of battery voltage transients on battery-bus power subsystems. Comparison with test data show that the model is capable of giving a good fit in these circumstances.

  18. Establishment of Retinoblastoma Model in NOD-SCID Mice and Study of Metastasis

    Institute of Scientific and Technical Information of China (English)

    Bo Zhang; Yongping Li; Xiufeng Zhong; Wenge Huang; Li Nie; Wenxin Zhang

    2005-01-01

    Purpose: To establish model of retinoblastoma subcutaneously in NOD-SCID mice and study rules of formation and distribution of retinoblastoma metastasis.Methods: Retinoblastoma cells SO-RB50 were inoculated subcutaneously in NOD-SCID mice. Animal acts and tumor formation, growth and metastasis in NOD-SCID mice were observed. Primary and metastatic tumors were studied pathohistologically by HE and immunohistochemical staining.Results: The latent periods of tumor growth were 12~19 days and the taken rate of tumor was 100%. 32 days later, 5 NOD-SCID mice were found with tumors that had metastasized to areas mainly located in the abdominal cavity and the side of the kidney; the metastatic time of tumors in the mice also differed. The tumor cells of the primary nodules and the metastasis were similar with human retinoblastoma cells and positive in immunohistochemical staining of NSE.Conclusion: The subcutaneous model of retinoblastoma in NOD-SCID mice showed a high taken rate and a short latent period of tumor, which had a high metastatic rate and was the best model in research of behaviors of retinoblastoma at present.

  19. An accurate simulation model for single-photon avalanche diodes including important statistical effects

    Science.gov (United States)

    Qiuyang, He; Yue, Xu; Feifei, Zhao

    2013-10-01

    An accurate and complete circuit simulation model for single-photon avalanche diodes (SPADs) is presented. The derived model is not only able to simulate the static DC and dynamic AC behaviors of an SPAD operating in Geiger-mode, but also can emulate the second breakdown and the forward bias behaviors. In particular, it considers important statistical effects, such as dark-counting and after-pulsing phenomena. The developed model is implemented using the Verilog-A description language and can be directly performed in commercial simulators such as Cadence Spectre. The Spectre simulation results give a very good agreement with the experimental results reported in the open literature. This model shows a high simulation accuracy and very fast simulation rate.

  20. Extending the Scope of the Acculturation/Pidginization Model to Include Cognition.

    Science.gov (United States)

    Schumann, John H.

    1990-01-01

    Examines five cognitive models for second-language acquisition (SLA) and assesses how each might account for the Pidginized interlanguage found in the early stages of second-language acquisition. (23 references) (JL)

  1. A model for including Arduino microcontroller programming in the introductory physics lab

    CERN Document Server

    Haugen, Andrew J

    2014-01-01

    The paper describes a curricular framework for introducing microcontroller programming in the University Physics lab. The approach makes use of Modeling Instruction, an effective approach for teaching science at the secondary level in which student learn the standard material by developing and deploying models of the physical world. In our approach, students engage with a context-rich problem that can be solved with one or more sensors and a microcontroller. The solution path we describe then consists of developing a mathematical model for how the sensors' data can be mapped to a meaningful measurement, and further, developing an algorithmic model that will be implemented in the microcontroller. Once the system is developed and implemented, students are given an array of similar problems in which they can deploy their data collection system. Results from the implementation of this idea, in two University Physics sections, using Arduino microcontrollers, are also described.

  2. Global warming in a coupled climate model including oceanic eddy-induced advection

    Science.gov (United States)

    Hirst, Anthony C.; Gordon, Hal B.; O'Farrell, Siobhan P.

    The Gent and McWilliams (GM) parameterization for large-scale water transport caused by mesoscale oceanic eddies is introduced into the oceanic component of a global coupled ocean-atmosphere model. Parallel simulations with and without the GM scheme are performed to examine the effect of this parameterization on model behavior under constant atmospheric CO2 and on the model response to increasing CO2. The control (constant CO2) runs show substantial differences in the oceanic stratification and extent of convection, similar to differences found previously using uncoupled ocean models. The transient (increasing CO2) runs show moderate differences in the rate of oceanic heat sequestration (less in the GM case), as expected based on passive tracer uptake studies. However, the surface warming is weaker in the GM case, especially over the Southern Ocean, which is contrary to some recent supposition. Reasons for the reduced warming in the GM case are discussed.

  3. Empirical Validation of a Thermal Model of a Complex Roof Including Phase Change Materials

    CERN Document Server

    Guichard, Stéphane; Bigot, Dimitri; Malet-Damour, Bruno; Libelle, Teddy; Boyer, Harry

    2015-01-01

    This paper deals with the empirical validation of a building thermal model using a phase change material (PCM) in a complex roof. A mathematical model dedicated to phase change materials based on the heat apparent capacity method was implemented in a multi-zone building simulation code, the aim being to increase understanding of the thermal behavior of the whole building with PCM technologies. To empirically validate the model, the methodology is based both on numerical and experimental studies. A parametric sensitivity analysis was performed and a set of parameters of the thermal model have been identified for optimization. The use of a generic optimization program called GenOpt coupled to the building simulation code enabled to determine the set of adequate parameters. We first present the empirical validation methodology and main results of previous work. We then give an overview of GenOpt and its coupling with the building simulation code. Finally, once the optimization results are obtained, comparisons o...

  4. A Coupled MHD and Thermal Model Including Electrostatic Sheath for Magnetoplasmadynamic Thruster Simulation

    Science.gov (United States)

    Kawasaki, Akira; Kubota, Kenichi; Funaki, Ikkoh; Okuno, Yoshihiro

    2016-09-01

    Steady-state and self-field magnetoplasmadynamic (MPD) thruster, which utilizes high-intensity direct-current (DC) discharge, is one of the prospective candidates of future high-power electric propulsion devices. In order to accurately assess the thrust performance and the electrode temperature, input electric power and wall heat flux must correctly be evaluated where electrostatic sheaths formed in close proximity of the electrodes affect these quantities. Conventional model simulates only plasma flows occurring in MPD thrusters with the absence of electrostatic sheath consideration. Therefore, this study extends the conventional model to a coupled magnetohydrodynamic (MHD) and thermal model by incorporating the phenomena relevant to the electrostatic sheaths. The sheaths are implemented as boundary condition of the MHD model on the walls. This model simulated the operation of the 100-kW-class thruster at discharge current ranging from 6 to 10 kA with argon propellant. The extended model reproduced the discharge voltages and wall heat load which are consistent with past experimental results. In addition, the simulation results indicated that cathode sheath voltages account for approximately 5-7 V subject to approximately 20 V of discharge voltages applied between the electrodes. This work was supported by JSPS KAKENHI Grant Numbers 26289328 and 15J10821.

  5. Including sugar cane in the agro-ecosystem model ORCHIDEE-STICS: calibration and validation

    Science.gov (United States)

    Valade, A.; Vuichard, N.; Ciais, P.; Viovy, N.

    2011-12-01

    Sugarcane is currently the most efficient bioenergy crop with regards to the energy produced per hectare. With approximately half the global bioethanol production in 2005, and a devoted land area expected to expand globally in the years to come, sugar cane is at the heart of the biofuel debate. Dynamic global vegetation models coupled with agronomical models are powerful and novel tools to tackle many of the environmental issues related to biofuels if they are carefully calibrated and validated against field observations. Here we adapt the agro-terrestrial model ORCHIDEE-STICS for sugar cane simulations. Observation data of LAI are used to evaluate the sensitivity of the model to parameters of nitrogen absorption and phenology, which are calibrated in a systematic way for six sites in Australia and La Reunion. We find that the optimal set of parameters is highly dependent on the sites' characteristics and that the model can reproduce satisfactorily the evolution of LAI. This careful calibration of ORCHIDEE-STICS for sugar cane biomass production for different locations and technical itineraries provides a strong basis for further analysis of the impacts of bioenergy-related land use change on carbon cycle budgets. As a next step, a sensitivity analysis is carried out to estimate the uncertainty of the model in biomass and carbon flux simulation due to its parameterization.

  6. Large Eddy simulation of turbulence: A subgrid scale model including shear, vorticity, rotation, and buoyancy

    Science.gov (United States)

    Canuto, V. M.

    1994-01-01

    The Reynolds numbers that characterize geophysical and astrophysical turbulence (Re approximately equals 10(exp 8) for the planetary boundary layer and Re approximately equals 10(exp 14) for the Sun's interior) are too large to allow a direct numerical simulation (DNS) of the fundamental Navier-Stokes and temperature equations. In fact, the spatial number of grid points N approximately Re(exp 9/4) exceeds the computational capability of today's supercomputers. Alternative treatments are the ensemble-time average approach, and/or the volume average approach. Since the first method (Reynolds stress approach) is largely analytical, the resulting turbulence equations entail manageable computational requirements and can thus be linked to a stellar evolutionary code or, in the geophysical case, to general circulation models. In the volume average approach, one carries out a large eddy simulation (LES) which resolves numerically the largest scales, while the unresolved scales must be treated theoretically with a subgrid scale model (SGS). Contrary to the ensemble average approach, the LES+SGS approach has considerable computational requirements. Even if this prevents (for the time being) a LES+SGS model to be linked to stellar or geophysical codes, it is still of the greatest relevance as an 'experimental tool' to be used, inter alia, to improve the parameterizations needed in the ensemble average approach. Such a methodology has been successfully adopted in studies of the convective planetary boundary layer. Experienc e with the LES+SGS approach from different fields has shown that its reliability depends on the healthiness of the SGS model for numerical stability as well as for physical completeness. At present, the most widely used SGS model, the Smagorinsky model, accounts for the effect of the shear induced by the large resolved scales on the unresolved scales but does not account for the effects of buoyancy, anisotropy, rotation, and stable stratification. The

  7. Large-scale screening of disease model through ENU mutagenesis in mice

    Institute of Scientific and Technical Information of China (English)

    HE Fang; WANG Zixing; ZHAO Jing; BAO Jie; DING Jun; RUAN Haibin; XIE Qing; ZHANG Zuoming; GAO Xiang

    2003-01-01

    Manipulation of mouse genome has merged as one of the most important approaches for studying gene function and establishing the disease model because of the high homology between human genome and mouse genome. In this study, the chemical mutagen ethylnitrosourea (ENU) was employed for inducing germ cell mutations in male C57BL/6J mice. The first generation (G1) of the backcross of these mutated mice, totally 3172, was screened for abnormal phenotypes on gross morphology, behavior, learning and memory, auditory brainstem response (ABR), electrocardiogram (ECG), electroretinogram (ERG), flash-visual evoked potential (F-VEP), bone mineral density, and blood sugar level. 595 mice have been identified with specific dominant abnormalities. Fur color changes, eye defects and hearing loss occurred at the highest frequency. Abnormalities related to metabolism alteration are least frequent. Interestingly, eye defects displayed significant left-right asymmetry and sex preference. Sex preference is also observed in mice with abnormal bone mineral density. Among 104 G1 generation mutant mice examined for inheritability, 14 of them have been confirmed for passing abnormal phenotypes to their progenies. However, we did not observe behavior abnormalities of G1 mice to be inheritable, suggesting multi-gene control for these complicated functions in mice. In conclusion, the generation of these mutants paves the way for understanding molecular and cellular mechanisms of these abnormal phenotypes, and accelerates the cloning of disease-related genes.

  8. Accurate and efficient modeling of global seismic wave propagation for an attenuative Earth model including the center

    Science.gov (United States)

    Toyokuni, Genti; Takenaka, Hiroshi

    2012-06-01

    We propose a method for modeling global seismic wave propagation through an attenuative Earth model including the center. This method enables accurate and efficient computations since it is based on the 2.5-D approach, which solves wave equations only on a 2-D cross section of the whole Earth and can correctly model 3-D geometrical spreading. We extend a numerical scheme for the elastic waves in spherical coordinates using the finite-difference method (FDM), to solve the viscoelastodynamic equation. For computation of realistic seismic wave propagation, incorporation of anelastic attenuation is crucial. Since the nature of Earth material is both elastic solid and viscous fluid, we should solve stress-strain relations of viscoelastic material, including attenuative structures. These relations represent the stress as a convolution integral in time, which has had difficulty treating viscoelasticity in time-domain computation such as the FDM. However, we now have a method using so-called memory variables, invented in the 1980s, followed by improvements in Cartesian coordinates. Arbitrary values of the quality factor (Q) can be incorporated into the wave equation via an array of Zener bodies. We also introduce the multi-domain, an FD grid of several layers with different grid spacings, into our FDM scheme. This allows wider lateral grid spacings with depth, so as not to perturb the FD stability criterion around the Earth center. In addition, we propose a technique to avoid the singularity problem of the wave equation in spherical coordinates at the Earth center. We develop a scheme to calculate wavefield variables on this point, based on linear interpolation for the velocity-stress, staggered-grid FDM. This scheme is validated through a comparison of synthetic seismograms with those obtained by the Direct Solution Method for a spherically symmetric Earth model, showing excellent accuracy for our FDM scheme. As a numerical example, we apply the method to simulate seismic

  9. Optical cryo-imaging of kidney mitochondrial redox state in diabetic mice models

    Science.gov (United States)

    Maleki, S.; Sepehr, R.; Staniszewski, K.; Sheibani, N.; Sorenson, C. M.; Ranji, M.

    2012-03-01

    Oxidative stress (OS), which increases during diabetes, exacerbates the development and progression of diabetes complications including renal vascular and proximal tubule cell dysfunction. The objective of this study was to investigate the changes in the metabolic state of the tissue in diabetic mice kidneys using fluorescence imaging. Mitochondrial metabolic coenzymes NADH (Nicotinamide Adenine Dinucleotide), and FADH-2 (Flavin Adenine Dinucleotide) are autofluorescent and can be monitored without exogenous labels by optical techniques. The ratio of the fluorescence intensity of these fluorophores, (NADH/FAD), called the NADH redox ratio (RR), is a marker of metabolic state of a tissue. We examined mitochondrial redox states of kidneys from diabetic mice, Akita/+ and its control wild type (WT) for a group of 8- and 12-week-old mice. Average intensity and histogram of maximum projected images of FAD, NADH, and NADH RR were calculated for each kidney. Our results indicated a 17% decrease in the mean NADH RR of the kidney from 8-week-old mice compared with WT mice and, a 30% decrease in the mean NADH RR of kidney from12-week-old mice compared with WT mice. These results indicated an increase in OS in diabetic animals and its progression over time. Thus, NADH RR can be used as a hallmark of OS in diabetic kidney allowing temporal identification of oxidative state.

  10. A two-phase solid/fluid model for dense granular flows including dilatancy effects

    Science.gov (United States)

    Mangeney, Anne; Bouchut, Francois; Fernandez-Nieto, Enrique; Koné, El-Hadj; Narbona-Reina, Gladys

    2016-04-01

    Describing grain/fluid interaction in debris flows models is still an open and challenging issue with key impact on hazard assessment [{Iverson et al.}, 2010]. We present here a two-phase two-thin-layer model for fluidized debris flows that takes into account dilatancy effects. It describes the velocity of both the solid and the fluid phases, the compression/dilatation of the granular media and its interaction with the pore fluid pressure [{Bouchut et al.}, 2016]. The model is derived from a 3D two-phase model proposed by {Jackson} [2000] based on the 4 equations of mass and momentum conservation within the two phases. This system has 5 unknowns: the solid and fluid velocities, the solid and fluid pressures and the solid volume fraction. As a result, an additional equation inside the mixture is necessary to close the system. Surprisingly, this issue is inadequately accounted for in the models that have been developed on the basis of Jackson's work [{Bouchut et al.}, 2015]. In particular, {Pitman and Le} [2005] replaced this closure simply by imposing an extra boundary condition at the surface of the flow. When making a shallow expansion, this condition can be considered as a closure condition. However, the corresponding model cannot account for a dissipative energy balance. We propose here an approach to correctly deal with the thermodynamics of Jackson's model by closing the mixture equations by a weak compressibility relation following {Roux and Radjai} [1998]. This relation implies that the occurrence of dilation or contraction of the granular material in the model depends on whether the solid volume fraction is respectively higher or lower than a critical value. When dilation occurs, the fluid is sucked into the granular material, the pore pressure decreases and the friction force on the granular phase increases. On the contrary, in the case of contraction, the fluid is expelled from the mixture, the pore pressure increases and the friction force diminishes. To

  11. Including the effects of debris cover in a distributed glacier energy balance model (Invited)

    Science.gov (United States)

    Pellicciotti, F.; Reid, T.; Carenzo, M.; Brock, B. W.

    2010-12-01

    Distributed models of glacier energy balance, which make use of digital elevation models and extensive spatial data on local meteorology, have become very useful tools for predicting glacial ablation and runoff in recent years. They generally function by running a one-dimensional energy balance model at every point on a grid on the glacier surface - for each point in the grid the ablation is calculated based on the balance of heat fluxes at the ice-air boundary. However, one key component has been missing from distributed models to date, namely the effects of debris cover. Many glacier ablation zones are mantled in near-continuous blankets of rock debris, and debris-covered glaciers are important drivers of the water cycle in the European Alps, Andes and Himalayas. Moreover, debris covers have been seen to expand in recent years, so it is essential to assess exactly how the presence of debris may affect a glacier’s surface energy balance and potential responses to climate changes. The effects of a debris cover are complicated by the varying surface roughness, albedo and thermal properties of the debris in question, but generally a debris cover reduces glacier melt rate by insulating the glacier surface from direct solar radiation. Even on glaciers where the debris cover is not continuous, isolated patches of debris caused by rockfalls can affect the glacier evolution by introducing differential ablation across the glacier surface, thus creating ice-cored moraines that may persist after ‘clean’ parts of the glacier have wasted away. This paper presents the results of incorporating a one-dimensional ‘debris energy balance model’ called DEB-Model (Reid and Brock 2010) into a distributed melt model for Haut Glacier d’Arolla, Switzerland. DEB-Model numerically estimates debris surface temperature by considering the balance of heat fluxes at the air-debris interface, then calculates heat conduction through the debris in order to estimate melt rates at the

  12. Reversal learning in C58 mice: Modeling higher order repetitive behavior.

    Science.gov (United States)

    Whitehouse, Cristina M; Curry-Pochy, Lisa S; Shafer, Robin; Rudy, Joseph; Lewis, Mark H

    2017-08-14

    Restricted, repetitive behaviors are diagnostic for autism and prevalent in other neurodevelopmental disorders. These behaviors cluster as repetitive sensory-motor behaviors and behaviors reflecting resistance to change. The C58 mouse strain is a promising model for these behaviors as it emits high rates of aberrant repetitive sensory-motor behaviors. The purpose of the present study was to extend characterization of the C58 model to resistance to change. This was done by comparing C58 to C57BL/6 mice on a reversal learning task under either a 100% or 80%/20% probabilistic reinforcement schedule. In addition, the effect of environmental enrichment on performance of this task was assessed as this rearing condition markedly reduces repetitive sensory-motor behavior in C58 mice. Little difference was observed between C58 and control mice under a 100% schedule of reinforcement. The 80%/20% probabilistic schedule of reinforcement generated substantial strain differences, however. Importantly, no strain difference was observed in acquisition, but C58 mice were markedly impaired in their ability to reverse their pattern of responding from the previously high density reinforcement side. Environmental enrichment did not impact acquisition under the probabilistic reinforcement schedule, but enriched C58 mice performed significantly better than standard housed C58 mice in reversal learning. Thus, C58 mice exhibit behaviors that reflect both repetitive sensory motor behaviors as well as behavior that reflects resistance to change. Moreover, both clusters of repetitive behavior were attenuated by environmental enrichment. Such findings, along with the reported social deficits in C58 mice, increase the translational value of this mouse model to autism. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. An induction machine model including interbar currents for studying performances during transients and steady state

    Energy Technology Data Exchange (ETDEWEB)

    Razik, H. [Universite Henri Poincare, GREEN, CNRS-UMR 7037, BP 239, F-54506 Vandoeuvre-les-Nancy Cedex (France); Henao, H. [University of Picardie, CREA, 33 rue Saint Leu, F-80039 Amiens Cedex 1 (France); Carlson, R. [GRUCAD/CTC/UFSC, Campus Universitario, C.P. 436, Florianopolis - SC, 88040-900 (Brazil)

    2009-01-15

    This paper presents a mathematical model of a three-phase induction motor taking into consideration the interbar contacts. Several models have been available in the references. However, they consider the rotor of the induction motor as being constituted either a three-phase or a squirrel cage even if it operates under stator and/or rotor faults condition. Nonetheless, the contact between a bar and the iron core for the machine has to be considered, especially when a rotor fault occurs. It is obvious that rotor currents are under the influence of rotor constitution materials. So, the paper aim's concerns a transient model of the induction motors which can consider the rotor broken bars defect. Despite its increasing complexity, it could be able to provide with useful indications for diagnostic purposes. This model is advocated for the simulation of motors behavior under rotor defect which takes into account the interbar currents. The proposed technique is based on the mesh model analysis of the squirrel cage. As low power induction motors are prevalent in industrial plants, we pay a special attention on them. Notwithstanding, additional currents are due to the contact between the non-insulated bar constituting the squirrel cage to the rotor iron core. The monitoring of induction motors is predominantly made through the stator current analysis of the motor when it operates at nominal condition. Moreover, this one is observed in steady state operating system, knowing that the motor is generally fed by a sinusoidal supply. Consequently, simulation results showed in this paper prove the effectiveness of the proposed approach, and the impact of interbar resistance both on the model and the line current spectrum for the diagnostic. An experimental test proves the effectiveness of this model. (author)

  14. Including crystal structure attributes in machine learning models of formation energies via Voronoi tessellations

    Science.gov (United States)

    Ward, Logan; Liu, Ruoqian; Krishna, Amar; Hegde, Vinay I.; Agrawal, Ankit; Choudhary, Alok; Wolverton, Chris

    2017-07-01

    While high-throughput density functional theory (DFT) has become a prevalent tool for materials discovery, it is limited by the relatively large computational cost. In this paper, we explore using DFT data from high-throughput calculations to create faster, surrogate models with machine learning (ML) that can be used to guide new searches. Our method works by using decision tree models to map DFT-calculated formation enthalpies to a set of attributes consisting of two distinct types: (i) composition-dependent attributes of elemental properties (as have been used in previous ML models of DFT formation energies), combined with (ii) attributes derived from the Voronoi tessellation of the compound's crystal structure. The ML models created using this method have half the cross-validation error and similar training and evaluation speeds to models created with the Coulomb matrix and partial radial distribution function methods. For a dataset of 435 000 formation energies taken from the Open Quantum Materials Database (OQMD), our model achieves a mean absolute error of 80 meV/atom in cross validation, which is lower than the approximate error between DFT-computed and experimentally measured formation enthalpies and below 15% of the mean absolute deviation of the training set. We also demonstrate that our method can accurately estimate the formation energy of materials outside of the training set and be used to identify materials with especially large formation enthalpies. We propose that our models can be used to accelerate the discovery of new materials by identifying the most promising materials to study with DFT at little additional computational cost.

  15. High resolution multi model Climate change scenario over India including first uncertainty assessment

    Science.gov (United States)

    Kumar, P.; Wiltshire, A.; Asharaf, S.; Ahrens, B.; Lucas-Picher, P.; Christensen, J. H.; Gobiet, A.; Saeed, F.; Hagemann, S.; Jacob, D.

    2011-12-01

    This study presents the possible regional climate change over SA with a focus over India as simulated by three very-high-resolution regional climate models. The models are driven by the same lateral boundary conditions from two global models (ECHAM5-MPIOM and HadCM3) under the IPCC AR4 SRES A1B scenario at horizontal resolution of ~25km, except one model which is simulated for only one GCM. The results are presented for two time slices 2021-2050 and 2070-2099. The analysis concentrates along precipitation and temperature over land and focuses mainly on the monsoon season. The circulation parameter is also discussed. In general all models show a clear signal of gradual wide-spread warming throughout the 21st century. The ensemble-mean warming evident at the end of 2050 is 1-2K, whereas it is 3-5K at the end of century. The projected pattern of the precipitation change shows spatial variability. The increase in precipitation is noticed over peninsular and coastal areas and no change or decrease over areas away from the ocean. The influence of the driving GCM on projected precipitation change simulated with each RCM is as strong as the variability among the RCMs driven with one GCM. Some results of the first uncertainties assessment are also presented.

  16. HIV model parameter estimates from interruption trial data including drug efficacy and reservoir dynamics.

    Directory of Open Access Journals (Sweden)

    Rutao Luo

    Full Text Available Mathematical models based on ordinary differential equations (ODE have had significant impact on understanding HIV disease dynamics and optimizing patient treatment. A model that characterizes the essential disease dynamics can be used for prediction only if the model parameters are identifiable from clinical data. Most previous parameter identification studies for HIV have used sparsely sampled data from the decay phase following the introduction of therapy. In this paper, model parameters are identified from frequently sampled viral-load data taken from ten patients enrolled in the previously published AutoVac HAART interruption study, providing between 69 and 114 viral load measurements from 3-5 phases of viral decay and rebound for each patient. This dataset is considerably larger than those used in previously published parameter estimation studies. Furthermore, the measurements come from two separate experimental conditions, which allows for the direct estimation of drug efficacy and reservoir contribution rates, two parameters that cannot be identified from decay-phase data alone. A Markov-Chain Monte-Carlo method is used to estimate the model parameter values, with initial estimates obtained using nonlinear least-squares methods. The posterior distributions of the parameter estimates are reported and compared for all patients.

  17. Kinetic modelling of anaerobic hydrolysis of solid wastes, including disintegration processes

    Energy Technology Data Exchange (ETDEWEB)

    García-Gen, Santiago [Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Sousbie, Philippe; Rangaraj, Ganesh [INRA, UR50, Laboratoire de Biotechnologie de l’Environnement, Avenue des Etangs, Narbonne F-11100 (France); Lema, Juan M. [Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Rodríguez, Jorge, E-mail: jrodriguez@masdar.ac.ae [Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Institute Centre for Water and Environment (iWater), Masdar Institute of Science and Technology, PO Box 54224 Abu Dhabi (United Arab Emirates); Steyer, Jean-Philippe; Torrijos, Michel [INRA, UR50, Laboratoire de Biotechnologie de l’Environnement, Avenue des Etangs, Narbonne F-11100 (France)

    2015-01-15

    Highlights: • Fractionation of solid wastes into readily and slowly biodegradable fractions. • Kinetic coefficients estimation from mono-digestion batch assays. • Validation of kinetic coefficients with a co-digestion continuous experiment. • Simulation of batch and continuous experiments with an ADM1-based model. - Abstract: A methodology to estimate disintegration and hydrolysis kinetic parameters of solid wastes and validate an ADM1-based anaerobic co-digestion model is presented. Kinetic parameters of the model were calibrated from batch reactor experiments treating individually fruit and vegetable wastes (among other residues) following a new protocol for batch tests. In addition, decoupled disintegration kinetics for readily and slowly biodegradable fractions of solid wastes was considered. Calibrated parameters from batch assays of individual substrates were used to validate the model for a semi-continuous co-digestion operation treating simultaneously 5 fruit and vegetable wastes. The semi-continuous experiment was carried out in a lab-scale CSTR reactor for 15 weeks at organic loading rate ranging between 2.0 and 4.7 g VS/L d. The model (built in Matlab/Simulink) fit to a large extent the experimental results in both batch and semi-continuous mode and served as a powerful tool to simulate the digestion or co-digestion of solid wastes.

  18. A void ratio dependent water retention curve model including hydraulic hysteresis

    Directory of Open Access Journals (Sweden)

    Pasha Amin Y.

    2016-01-01

    Full Text Available Past experimental evidence has shown that Water Retention Curve (WRC evolves with mechanical stress and structural changes in soil matrix. Models currently available in the literature for capturing the volume change dependency of WRC are mainly empirical in nature requiring an extensive experimental programme for parameter identification which renders them unsuitable for practical applications. In this paper, an analytical model for the evaluation of the void ratio dependency of WRC in deformable porous media is presented. The approach proposed enables quantification of the dependency of WRC on void ratio solely based on the form of WRC at the reference void ratio and requires no additional parameters. The effect of hydraulic hysteresis on the evolution process is also incorporated in the model, an aspect rarely addressed in the literature. Expressions are presented for the evolution of main and scanning curves due to loading and change in the hydraulic path from scanning to main wetting/drying and vice versa as well as the WRC parameters such as air entry value, air expulsion value, pore size distribution index and slope of the scanning curve. The model is validated using experimental data on compacted and reconstituted soils subjected to various hydro-mechanical paths. Good agreement is obtained between model predictions and experimental data in all the cases considered.

  19. A discrete model for the apparent viscosity of polydisperse suspensions including maximum packing fraction

    CERN Document Server

    Dörr, Aaron; Mehdizadeh, Amirfarhang

    2012-01-01

    Based on the notion of a construction process consisting of the stepwise addition of particles to the pure fluid, a discrete model for the apparent viscosity as well as for the maximum packing fraction of polydisperse suspensions of spherical, non-colloidal particles is derived. The model connects the approaches by Bruggeman and Farris and is valid for large size ratios of consecutive particle classes during the construction process. Furthermore, a new general form of the well-known Krieger equation allowing for the choice of a second-order Taylor coefficient for the volume fraction is proposed and then applied as a monodisperse reference equation in the course of polydisperse modeling. By applying the polydisperse viscosity model to two different particle size distributions (Rosin-Rammler and uniform distribution), the influence of polydispersity on the apparent viscosity is examined. The extension of the model to the case of small size ratios as well as to the inclusion of shear rate effects is left for fut...

  20. Sciatic nerve cuffing in mice: a model of sustained neuropathic pain.

    Science.gov (United States)

    Benbouzid, Malika; Pallage, Viviane; Rajalu, Mathieu; Waltisperger, Elisabeth; Doridot, Stéphane; Poisbeau, Pierrick; Freund-Mercier, Marie José; Barrot, Michel

    2008-07-01

    Because of its severity, chronicity, resistance to usual therapy and its consequences on quality of life, neuropathic pain represents a real clinical challenge. Fundamental research on this pathology uses metabolic, pharmacological or traumatic models in rodents that reproduce the characteristic human pain symptoms. In 1996, Mosconi and Kruger morphologically described a model of peripheral neuropathy in which a cuff of polyethylene tubing was placed around the sciatic nerve in rats. In the present study, we evaluated the behavioral consequences of this neuropathic pain model in C57Bl/6J mice which is the main genetic background used for studies in transgenic mice. A short cuff of polyethylene tubing was unilaterally placed around the main branch of the sciatic nerve. It induced an ipsilateral heat thermal hyperalgesia lasting around 3 weeks, and a sustained ipsilateral mechanical allodynia lasting at least 2 months. We showed that this neuropathic pain model is insensitive to ketoprofen, a non-steroidal anti-inflammatory drug. Morphine treatment acutely suppressed the mechanical allodynia, but tolerance to this effect rapidly developed. The analysis of video recordings revealed that most aspects of spontaneous behavior remained unaffected on the long term, excepted for a decrease in the time spent at social interaction for the neuropathic mice. Using the elevated plus-maze and the marble-burying test, we also showed that neuropathic mice develop an anxiety phenotype. Our data indicate that sciatic nerve cuffing in mice is a pertinent model for the study of nociceptive and emotional consequences of sustained neuropathic pain.

  1. Complete Loss and Thermal Model of Power Semiconductors Including Device Rating Information

    DEFF Research Database (Denmark)

    Ma, Ke; Bahman, Amir Sajjad; Beczkowski, Szymon;

    2015-01-01

    loading but also the device rating as input variables. The quantified correlation between the power loss, thermal impedance and silicon area of Insulated Gate Bipolar Transistor (IGBT) is mathematically established. By this new modeling approach, all factors that have impacts to the loss and thermal......Thermal loading of power devices are closely related to the reliability performance of the whole converter system. The electrical loading and device rating are both important factors that determine the loss and thermal behaviors of power semiconductor devices. In the existing loss and thermal...... models, only the electrical loadings are focused and treated as design variables, while the device rating is normally pre-defined by experience with limited design flexibility. Consequently, a more complete loss and thermal model is proposed in this paper, which takes into account not only the electrical...

  2. A Simple Model of Fields Including the Strong or Nuclear Force and a Cosmological Speculation

    Directory of Open Access Journals (Sweden)

    David L. Spencer

    2016-10-01

    Full Text Available Reexamining the assumptions underlying the General Theory of Relativity and calling an object's gravitational field its inertia, and acceleration simply resistance to that inertia, yields a simple field model where the potential (kinetic energy of a particle at rest is its capacity to move itself when its inertial field becomes imbalanced. The model then attributes electromagnetic and strong forces to the effects of changes in basic particle shape. Following up on the model's assumption that the relative intensity of a particle's gravitational field is always inversely related to its perceived volume and assuming that all black holes spin, may create the possibility of a cosmic rebound where a final spinning black hole ends with a new Big Bang.

  3. Numerical models of single- and double-negative metamaterials including viscous and thermal losses

    DEFF Research Database (Denmark)

    Cutanda Henriquez, Vicente; Sánchez-Dehesa, José

    2017-01-01

    Negative index acoustic metamaterials are artificial structures made of subwavelength units arranged in a lattice, whose effective acoustic parameters, bulk modulus and mass density, can be negative. In these materials, sound waves propagate inside the periodic structure, assumed rigid, showing...... extraordinary properties. We are interested in two particular cases: a double-negative metamaterial, where both parameters are negative at some frequencies, and a single-negative metamaterial with negative bulk modulus within a broader frequency band. In previous research involving the double......-negative metamaterial, numerical models with viscous and thermal losses were used to explain that the extraordinary behavior, predicted by analytical models and numerical simulations with no losses, disappeared when the metamaterial was measured in physical setups. The improvement of the models is allowing now a more...

  4. Damped structural dynamics models of large wind-turbine blades including material and structural damping

    Energy Technology Data Exchange (ETDEWEB)

    Chortis, D I; Chrysochoidis, N A; Saravanos, D A [Department of Mechanical Engineering and Aeronautics, University of Patras, Patras 26500 (Greece)

    2007-07-15

    The paper presents a brief description of composite damping mechanics for blade sections of arbitrary lamination and geometry. A damped 3-D shear beam element is presented enabling the assembly of damped structural dynamic models of blades with hollow multi-cell tubular laminated sections. Emphasis is placed to the inclusion of composite material coupling effects, first in the blade section stiffness and damping matrices and finally into the stiffness and damping matrices of the finite element. Evaluations of the beam element are presented, to quantify the material coupling effect on composite beams of simple box sections. Correlations between predicted and measured modal frequencies and damping values in small model Glass/Epoxy are also shown. Finally, the damped modal characteristics of a 35m realistic wind-turbine blade model design, are predicted.

  5. A study of a hamiltonian model for martensitic phase transformations including microkinetic energy

    CERN Document Server

    Theil, F

    1998-01-01

    How can a system in a macroscopically stable state explore energetically more favorable states, which are far away from the current equilibrium state? Based on continuum mechanical considerations we derive a Boussinesq-type equation which models the dynamics of martensitic phase transformations. The solutions of the system, which we refer to as microkinetically regularized wave equation exhibit strong oscillations after short times, thermalization can be confirmed. That means that macroscopic fluctuations of the solutions decay at the benefit of microscopic fluctuations. First analytical and numerical results on the propagation of phase boundaries and thermalization effects are presented. Despite the fact that model is conservative, it exhibits the hysteretic behavior. Such a behavior is usually interpreted in macroscopic models in terms of dissipative threshold which the driving force has to overcome to ensure that the phase transformation proceeds. The threshold value depends on the amount of the transforme...

  6. Hybrid Model Representation of a TLP Including Flexible Topsides in Non-Linear Regular Waves

    Directory of Open Access Journals (Sweden)

    Christof Wehmeyer

    2014-08-01

    Full Text Available The rising demand for renewable energy solutions is forcing the established industries to expand and continue evolving. For the wind energy sector, the vast resources in deep sea locations have encouraged research towards the installation of turbines in deeper waters. One of the most promising technologies able to solve this challenge is the floating wind turbine foundation. For the ultimate limit state, where higher order wave loads have a significant influence, a design tool that couples non-linear excitations with structural dynamics is required. To properly describe the behavior of such a structure, a numerical model is proposed and validated by physical test results. The model is applied to a case study of a tension leg platform with a flexible topside mimicking the tower and a lumped mass mimicking the rotor-nacelle assembly. The model is additionally compared to current commercial software, where the need for the coupled higher order dynamics proposed in this paper becomes evident.

  7. Loss and thermal model for power semiconductors including device rating information

    DEFF Research Database (Denmark)

    Ma, Ke; Bahman, Amir Sajjad; Beczkowski, Szymon;

    2014-01-01

    The electrical loading and device rating are both important factors that determine the loss and thermal behaviors of power semiconductor devices. In the existing loss and thermal models, only the electrical loadings are focused and treated as design variables, while the device rating is normally...... pre-defined by experience with poor design flexibility. Consequently a more complete loss and thermal model is proposed in this paper, which takes into account not only the electrical loading but also the device rating as input variables. The quantified correlation between the power loss, thermal...... impedance and silicon area of Insulated Gate Bipolar Transistor (IGBT) is mathematically established. By this new modeling approach, all factors that have impacts to the loss and thermal profiles of power devices can be accurately mapped, enabling more design freedom to optimize the efficiency and thermal...

  8. Complete Loss and Thermal Model of Power Semiconductors Including Device Rating Information

    DEFF Research Database (Denmark)

    Ma, Ke; Bahman, Amir Sajjad; Beczkowski, Szymon

    2015-01-01

    profiles of the power devices can accurately be mapped, enabling more design freedom to optimize the efficiency and thermal loading of the power converter. The proposed model can be further improved by experimental tests, and it is well agreed by both circuit and Finite Element Method (FEM) simulation......Thermal loading of power devices are closely related to the reliability performance of the whole converter system. The electrical loading and device rating are both important factors that determine the loss and thermal behaviors of power semiconductor devices. In the existing loss and thermal...... models, only the electrical loadings are focused and treated as design variables, while the device rating is normally pre-defined by experience with limited design flexibility. Consequently, a more complete loss and thermal model is proposed in this paper, which takes into account not only the electrical...

  9. Loss and thermal model for power semiconductors including device rating information

    DEFF Research Database (Denmark)

    Ma, Ke; Bahman, Amir Sajjad; Beczkowski, Szymon

    2014-01-01

    impedance and silicon area of Insulated Gate Bipolar Transistor (IGBT) is mathematically established. By this new modeling approach, all factors that have impacts to the loss and thermal profiles of power devices can be accurately mapped, enabling more design freedom to optimize the efficiency and thermal......The electrical loading and device rating are both important factors that determine the loss and thermal behaviors of power semiconductor devices. In the existing loss and thermal models, only the electrical loadings are focused and treated as design variables, while the device rating is normally...... pre-defined by experience with poor design flexibility. Consequently a more complete loss and thermal model is proposed in this paper, which takes into account not only the electrical loading but also the device rating as input variables. The quantified correlation between the power loss, thermal...

  10. A biomechanical model of the face including muscles for the prediction of deformations during speech production

    CERN Document Server

    Groleau, Julie; Marecaux, Christophe; Payrard, Natacha; Segaud, Brice; Rochette, Michel; Perrier, Pascal; Payan, Yohan

    2008-01-01

    A 3D biomechanical finite element model of the face is presented. Muscles are represented by piece-wise uniaxial tension cable elements linking the insertion points. Such insertion points are specific entities differing from nodes of the finite element mesh, which makes possible to change either the mesh or the muscle implementation totally independently of each other. Lip/teeth and upper lip/lower lip contacts are also modeled. Simulations of smiling and of an Orbicularis Oris activation are presented and interpreted. The importance of a proper account of contacts and of an accurate anatomical description is shown

  11. European air quality modelled by CAMx including the volatility basis set scheme

    Directory of Open Access Journals (Sweden)

    G. Ciarelli

    2015-12-01

    Full Text Available Four periods of EMEP (European Monitoring and Evaluation Programme intensive measurement campaigns (June 2006, January 2007, September–October 2008 and February–March 2009 were modelled using the regional air quality model CAMx with VBS (Volatility Basis Set approach for the first time in Europe within the framework of the EURODELTA-III model intercomparison exercise. More detailed analysis and sensitivity tests were performed for the period of February–March 2009 and June 2006 to investigate the uncertainties in emissions as well as to improve the modelling of organic aerosols (OA. Model performance for selected gas phase species and PM2.5 was evaluated using the European air quality database Airbase. Sulfur dioxide (SO2 and ozone (O3 were found to be overestimated for all the four periods with O3 having the largest mean bias during June 2006 and January–February 2007 periods (8.93 and 12.30 ppb mean biases, respectively. In contrast, nitrogen dioxide (NO2 and carbon monoxide (CO were found to be underestimated for all the four periods. CAMx reproduced both total concentrations and monthly variations of PM2.5 very well for all the four periods with average biases ranging from −2.13 to 1.04 μg m-3. Comparisons with AMS (Aerosol Mass Spectrometer measurements at different sites in Europe during February–March 2009, showed that in general the model over-predicts the inorganic aerosol fraction and under-predicts the organic one, such that the good agreement for PM2.5 is partly due to compensation of errors. The effect of the choice of volatility basis set scheme (VBS on OA was investigated as well. Two sensitivity tests with volatility distributions based on previous chamber and ambient measurements data were performed. For February–March 2009 the chamber-case reduced the total OA concentrations by about 43 % on average. On the other hand, a test based on ambient measurement data increased OA concentrations by about 47 % for the same

  12. Viscoelastic Model of Cross-Linked Polyethylene Including Effects of Temperature and Crystallinity

    Science.gov (United States)

    Olasz, L.; Gudmundson, P.

    2005-12-01

    Characterization of the mechanical behavior of cross-linked polyethylene (XLPE) commonly used in high voltage cable insulation was performed by an extensive set of isothermal uniaxial tensile relaxation tests. Tensile relaxation experiments were complemented by pressure-volume-temperature experiments as well as density and crystallinity measurements. Based on the experimental results, a viscoelastic power law model with four parameters was formulated, incorporating temperature and crystallinity dependence. It was found that a master curve can be developed by both horizontal and vertical shifting of the relaxation curves. The model was evaluated by making comparisons of the predicted stress responses with the measured responses in relaxation tests with transient temperature histories.

  13. Motivational disturbances and effects of L-dopa administration in neurofibromatosis-1 model mice.

    Directory of Open Access Journals (Sweden)

    David F Wozniak

    Full Text Available Children with neurofibromatosis type 1 (NF1 frequently have cognitive and behavioral deficits. Some of these deficits have been successfully modeled in Nf1 genetically-engineered mice that develop optic gliomas (Nf1 OPG mice. In the current study, we show that abnormal motivational influences affect the behavior of Nf1 OPG mice, particularly with regard to their response to novel environmental stimuli. For example, Nf1 OPG mice made fewer spontaneous alternations in a Y-maze and fewer arm entries relative to WT controls. However, analysis of normalized alternation data demonstrated that these differences were not due to a spatial working memory deficit. Other reported behavioral results (e.g., open-field test, below suggest that differential responses to novelty and/or other motivational influences may be more important determinants of these kinds of behavior than simple differences in locomotor activity/spontaneous movements. Importantly, normal long-term depression was observed in hippocampal slices from Nf1 OPG mice. Results from elevated plus maze testing showed that differences in exploratory activity between Nf1 OPG and WT control mice may be dependent on the environmental context (e.g., threatening or non-threatening under which exploration is being measured. Nf1 OPG mice also exhibited decreased exploratory hole poking in a novel holeboard and showed abnormal olfactory preferences, although L-dopa (50 mg/kg administration resolved the abnormal olfactory preference behaviors. Nf1 OPG mice displayed an attenuated response to a novel open field in terms of decreased ambulatory activity and rearing but only during the first 10 min of the session. Importantly, Nf1 OPG mice demonstrated investigative rearing deficits with regard to a novel hanging object suspended on one side of the field which were not rescued by L-dopa administration. Collectively, our results provide new data important for evaluating therapeutic treatments aimed at

  14. Myostatin deficiency partially rescues the bone phenotype of osteogenesis imperfecta model mice.

    Science.gov (United States)

    Oestreich, A K; Carleton, S M; Yao, X; Gentry, B A; Raw, C E; Brown, M; Pfeiffer, F M; Wang, Y; Phillips, C L

    2016-01-01

    Mice with osteogenesis imperfecta (+/oim), a disorder of bone fragility, were bred to mice with muscle over growth to test whether increasing muscle mass genetically would improve bone quality and strength. The results demonstrate that femora from mice carrying both mutations have greater mechanical integrity than their +/oim littermates. Osteogenesis imperfecta is a heritable connective tissue disorder due primarily to mutations in the type I collagen genes resulting in skeletal deformity and fragility. Currently, there is no cure, and therapeutic strategies encompass the use of antiresorptive pharmaceuticals and surgical bracing, with limited success and significant potential for adverse effects. Bone, a mechanosensing organ, can respond to high mechanical loads by increasing new bone formation and altering bone geometry to withstand increased forces. Skeletal muscle is a major source of physiological loading on bone, and bone strength is proportional to muscle mass. To test the hypothesis that congenic increases in muscle mass in the osteogenesis imperfecta murine model mouse (oim) will improve their compromised bone quality and strength, heterozygous (+/oim) mice were bred to mice deficient in myostatin (+/mstn), a negative regulator of muscle growth. The resulting adult offspring were evaluated for hindlimb muscle mass, and bone microarchitecture, physiochemistry, and biomechanical integrity. +/oim mice deficient in myostatin (+/mstn +/oim) were generated and demonstrated that myostatin deficiency increased body weight, muscle mass, and biomechanical strength in +/mstn +/oim mice as compared to +/oim mice. Additionally, myostatin deficiency altered the physiochemical properties of the +/oim bone but did not alter bone remodeling. Myostatin deficiency partially improved the reduced femoral bone biomechanical strength of adult +/oim mice by increasing muscle mass with concomitant improvements in bone microarchitecture and physiochemical properties.

  15. The island coalescence problem: scaling of reconnection in extended fluid models including higher-order moments

    CERN Document Server

    Ng, Jonathan; Hakim, Ammar; Bhattacharjee, Amitava; Stanier, Adam; Daughton, William; Wang, Liang; Germaschewski, Kai

    2015-01-01

    As modeling of collisionless magnetic reconnection in most space plasmas with realistic parameters is beyond the capability of today's simulations, due to the separation between global and kinetic length scales, it is important to establish scaling relations in model problems so as to extrapolate to realistic scales. Recently, large scale particle-in-cell (PIC) simulations of island coalescence have shown that the time averaged reconnection rate decreases with system size, while fluid systems at such large scales in the Hall regime have not been studied. Here we perform the complementary resistive MHD, Hall MHD and two fluid simulations using a ten-moment model with the same geometry. In contrast to the standard Harris sheet reconnection problem, Hall MHD is insufficient to capture the physics of the reconnection region. Additionally, motivated by the results of a recent set of hybrid simulations which show the importance of ion kinetics in this geometry, we evaluate the efficacy of the ten-moment model in re...

  16. Situational effects of the school factors included in the dynamic model of educational effectiveness

    NARCIS (Netherlands)

    Creerners, Bert; Kyriakides, Leonidas

    2009-01-01

    We present results of a longitudinal study in which 50 schools, 113 classes and 2,542 Cypriot primary students participated. We tested the validity of the dynamic model of educational effectiveness and especially its assumption that the impact of school factors depends on the current situation of th

  17. Turbulent combustion modelling of a confined premixed jet flame including heat loss effects using tabulated chemistry

    NARCIS (Netherlands)

    Gövert, S.; Mira, D.; Kok, J.B.W.; Vázquez, M.; Houzeaux, G.

    2015-01-01

    The present work addresses the coupling of a flamelet database, to a low-Mach approximation of the Navier–Stokes equations using scalar controlling variables. The model is characterized by the chemistry tabulation based on laminar premixed flamelets in combination with an optimal choice of the react

  18. Kinetic modelling of anaerobic hydrolysis of solid wastes, including disintegration processes.

    Science.gov (United States)

    García-Gen, Santiago; Sousbie, Philippe; Rangaraj, Ganesh; Lema, Juan M; Rodríguez, Jorge; Steyer, Jean-Philippe; Torrijos, Michel

    2015-01-01

    A methodology to estimate disintegration and hydrolysis kinetic parameters of solid wastes and validate an ADM1-based anaerobic co-digestion model is presented. Kinetic parameters of the model were calibrated from batch reactor experiments treating individually fruit and vegetable wastes (among other residues) following a new protocol for batch tests. In addition, decoupled disintegration kinetics for readily and slowly biodegradable fractions of solid wastes was considered. Calibrated parameters from batch assays of individual substrates were used to validate the model for a semi-continuous co-digestion operation treating simultaneously 5 fruit and vegetable wastes. The semi-continuous experiment was carried out in a lab-scale CSTR reactor for 15 weeks at organic loading rate ranging between 2.0 and 4.7 gVS/Ld. The model (built in Matlab/Simulink) fit to a large extent the experimental results in both batch and semi-continuous mode and served as a powerful tool to simulate the digestion or co-digestion of solid wastes.

  19. New phases in an extended Hubbard model explicitly including atomic polarizabilities

    NARCIS (Netherlands)

    Brink, van de J.; Meinders, M.B.J.; Lorenzana, J.; Eder, R.; Sawatzky, G.A.

    1996-01-01

    We consider the influence of a nearest-neighbor Coulomb interaction in an extended Hubbard model and introduce a new interaction term which simulates atomic polarizabilities. This has the effect of screening the on-site Coulomb interaction for charged excitations, unlike a neighbor Coulomb interacti

  20. Modeling of etch profile evolution including wafer charging effects using self consistent ion fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Hoekstra, R.J.; Kushner, M.J. [Univ. of Illinois, Urbana, IL (United States). Dept. of Electrical and Computer Engineering

    1996-12-31

    As high density plasma reactors become more predominate in industry, the need has intensified for computer aided design tools which address both equipment issues such as ion flux uniformity onto the water and process issues such etch feature profile evolution. A hierarchy of models has been developed to address these issues with the goal of producing a comprehensive plasma processing design capability. The Hybrid Plasma Equipment Model (HPEM) produces ion and neutral densities, and electric fields in the reactor. The Plasma Chemistry Monte Carlo Model (PCMC) determines the angular and energy distributions of ion and neutral fluxes to the wafer using species source functions, time dependent bulk electric fields, and sheath potentials from the HPEM. These fluxes are then used by the Monte Carlo Feature Profile Model (MCFP) to determine the time evolution of etch feature profiles. Using this hierarchy, the effects of physical modifications of the reactor, such as changing wafer clamps or electrode structures, on etch profiles can be evaluated. The effects of wafer charging on feature evolution are examined by calculating the fields produced by the charge deposited by ions and electrons within the features. The effect of radial variations and nonuniformity in angular and energy distribution of the reactive fluxes on feature profiles and feature charging will be discussed for p-Si etching in inductively-coupled plasma (ICP) sustained in chlorine gas mixtures. The effects of over- and under-wafer topography on etch profiles will also be discussed.

  1. Surface-wave mode coupling : modelling and inverting waveforms including body-wave phases

    NARCIS (Netherlands)

    Marquering, H.A.

    1996-01-01

    This thesis is concerned with a similar problem as addressed by Li & Tanimoto (1993) in the surfacewave mode approach. In this thesis it is shown that surface-wave mode coupling is required when body-wave phases in laterally heterogeneous media are modelled by surface-wave mode summation. An efficie

  2. The island coalescence problem: Scaling of reconnection in extended fluid models including higher-order moments

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Jonathan; Huang, Yi-Min; Hakim, Ammar; Bhattacharjee, A. [Center for Heliophysics, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Stanier, Adam; Daughton, William [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Wang, Liang; Germaschewski, Kai [Space Science Center and Physics Department, University of New Hampshire, Durham, New Hampshire 03824 (United States)

    2015-11-15

    As modeling of collisionless magnetic reconnection in most space plasmas with realistic parameters is beyond the capability of today's simulations, due to the separation between global and kinetic length scales, it is important to establish scaling relations in model problems so as to extrapolate to realistic scales. Recently, large scale particle-in-cell simulations of island coalescence have shown that the time averaged reconnection rate decreases with system size, while fluid systems at such large scales in the Hall regime have not been studied. Here, we perform the complementary resistive magnetohydrodynamic (MHD), Hall MHD, and two fluid simulations using a ten-moment model with the same geometry. In contrast to the standard Harris sheet reconnection problem, Hall MHD is insufficient to capture the physics of the reconnection region. Additionally, motivated by the results of a recent set of hybrid simulations which show the importance of ion kinetics in this geometry, we evaluate the efficacy of the ten-moment model in reproducing such results.

  3. Analytical and numerical modelling of thermoviscous shocks in their interactions in nonlinear fluids including dissipation

    DEFF Research Database (Denmark)

    Rasmussen, Anders Rønne; Sørensen, Mads Peter; Gaididei, Yuri Borisovich

    2010-01-01

    A wave equation, that governs finite amplitude acoustic disturbances in a thermoviscous Newtonian fluid, and includes nonlinear terms up to second order, is proposed. The equation preserves the Hamiltonian structure of the fundamental fluid dynamical equations in the non dissipative limit. An exact...

  4. Beyond mice: Emerging and transdisciplinary models for the study of early-onset myopathies.

    Science.gov (United States)

    Jagla, Krzysztof; Kalman, Benoit; Boudou, Thomas; Hénon, Sylvie; Batonnet-Pichon, Sabrina

    2017-04-01

    The use of the adapted models to decipher patho-physiological mechanisms of human diseases is always a great challenge. This is of particular importance for early-onset myopathies, in which pathological mutations often impact not only on muscle structure and function but also on developmental processes. Mice are currently the main animal model used to study neuromuscular disorders including the early-onset myopathies. However strategies based on simple animal models and on transdisciplinary approaches exploring mechanical muscle cell properties emerge as attractive, non-exclusive alternatives. These new ways provide valuable opportunities to improve our knowledge on how mechanical, biochemical, and genetic/epigenetic cues modulate the formation, organization and function of muscle tissues. Here we provide an overview of how single cell and micro-tissue engineering in parallel to non-mammalian, Drosophila and zebrafish models could contribute to filling gaps in our understanding of pathogenic mechanisms underlying early-onset myopathies. We also discuss their potential impact on designing new diagnostic and therapeutic strategies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. A model for heterogeneous traffic flows including non-motorized vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Oketch, T.G.

    2001-07-01

    This study is concerned with developing a traffic flow and emissions model suitable for heterogeneous traffic streams containing motorised and non-motorised vehicles. Such streams contain vehicle types such as private cars, buses and trucks as well as bicycles, motorcycles and other vehicular forms. The model covers the different vehicle types and allows for peculiar behaviours prevalent in such streams. In addition to an existing deterministic car following rule, the model incorporates detailed lateral movement algorithm with gradual lane change manoeuvres, the decisions of which are governed by fuzzy logic rules. For determination of pollutant emissions, the travel lane was divided into finite elements and total emissions aggregated for each element depending on the vehicle speeds and types. A methodology for estimation of emission rates, based on vehicle maintenance history, for countries without reliable inventories was proposed and used to obtain emission coefficients of CO, HC, NOx and Pb emissions in Kenya. In conclusion, the model has demonstrated that heterogeneous traffic can be effectively analysed by approaches that take their peculiar characteristics into consideration. In addition, it has also provided new insight in the performance and emission patterns of heterogeneous traffic streams which can be used to formulate regulatory directives governing the usage of lanes or provision of auxiliary carriageways for slower vehicles. (orig.) [German] In dieser Arbeit wurde ein Verkehrsfluss- und Emissions-Model fuer heterogene Verkehrsstroeme entwickelt. Solche Verkehrsstroeme enthalten nicht nur motorisierte Fahrzeuge wie Pkw, Lkw, Omnibus, Motorrad usw. sondern auch nicht-motorisierte Fahrzeuge wie Fahrrad und auch besondere Fahrzeugtypen, die auf Motorraedern oder Fahrraedern basieren. Im Modell wurden auch die entsprechenden besonderen Verhaeltnisse dieser Fahrzeugtypen beruecksichtigt. Die Bewegung von Fahrzeugen wurde in zwei Dimensionen modelliert. Auf

  6. Roughing It Up: Including Jump Components in the Measurement, Modeling and Forecasting of Return Volatility

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Andersen, Torben G.; Diebold, Francis X.

    A rapidly growing literature has documented important improvements in financial return volatility measurement and forecasting via use of realized variation measures constructed from high-frequency returns coupled with simple modeling procedures. Building on recent theoretical results in Barndorff...... bond yield, we find that jumps are both highly prevalent and distinctly less persistent than the continuous sample path variation process. Moreover, many jumps appear directly associated with specific macroeconomic news announcements. Separating jump from non-jump movements in a simple...... but sophisticated volatility forecasting model, we find that almost all of the predictability in daily, weekly, and monthly return volatilities comes from the non-jump component. Our results thus set the stage for a number of interesting future econometric developments and important financial applications...

  7. Ion-biomolecule collisions studied within the independent atom model including geometric screening corrections

    Science.gov (United States)

    Lüdde, H. J.; Achenbach, A.; Kalkbrenner, T.; Jankowiak, H. C.; Kirchner, T.

    2016-05-01

    A recently introduced model to account for geometric screening corrections in an independent-atom-model description of ion-molecule collisions is applied to proton collisions from amino acids and DNA and RNA nucleobases. The correction coefficients are obtained from using a pixel counting method (PCM) for the exact calculation of the effective cross sectional area that emerges when the molecular cross section is pictured as a structure of (overlapping) atomic cross sections. This structure varies with the relative orientation of the molecule with respect to the projectile beam direction and, accordingly, orientation-independent total cross sections are obtained from averaging the pixel count over many orientations. We present net capture and net ionization cross sections over wide ranges of impact energy and analyze the strength of the screening effect by comparing the PCM results with Bragg additivity rule cross sections and with experimental data where available. Work supported by NSERC, Canada.

  8. Mathematical analysis of a two-dimensional population model of metastatic growth including angiogenesis

    CERN Document Server

    Benzekry, Sebastien

    2010-01-01

    Angiogenesis is a key process in the tumoral growth which allows the cancerous tissue to impact on its vasculature in order to improve the nutrient's supply and the metastatic process. In this paper, we introduce a model for the density of metastasis which takes into account for this feature. It is a two dimensional structured equation with a vanishing velocity field and a source term on the boundary. We present here the mathematical analysis of the model, namely the well-posedness of the equation and the asymptotic behavior of the solutions, whose natural regularity led us to investigate some basic properties of the space $\\Wd(\\Om)=\\{V\\in L^1;\\;\\div(GV)\\in L^1\\}$, where $G$ is the velocity field of the equation.

  9. A model for thermal oxidation of Si and SiC including material expansion

    Energy Technology Data Exchange (ETDEWEB)

    Christen, T., E-mail: thomas.christen@ch.abb.com; Ioannidis, A. [ABB Corporate Research, Segelhofstrasse 1K, CH-5405 Baden (Switzerland); Winkelmann, C. [ETH Zürich, Seminar for Applied Mathematics, Rämistrasse 101, CH-8092 Zürich (Switzerland)

    2015-02-28

    A model based on drift-diffusion-reaction kinetics for Si and SiC oxidation is discussed, which takes the material expansion into account with an additional convection term. The associated velocity field is determined self-consistently from the local reaction rate. The approach allows a calculation of the densities of volatile species in an nm-resolution at the oxidation front. The model is illustrated with simulation results for the growth and impurity redistribution during Si oxidation and for carbon and silicon emission during SiC oxidation. The approach can be useful for the prediction of Si and/or C interstitial distribution, which is particularly relevant for the quality of metal-oxide-semiconductor electronic devices.

  10. A roller chain drive model including contact with guide-bars

    DEFF Research Database (Denmark)

    Pedersen, Sine Leergaard; Hansen, John Michael; Ambrósio, J. A. C.

    2004-01-01

    and continuous force methods, respectively. In the unilateral constraint methodology the kinematic constraints are introduced in the system anytime a contact between the rollers and the sprockets is detected. The condition for the constraint addition is based on the relative distance between the roller centre...... and the sprocket centre, i.e. a constraint is added when such distance is less than the pitch radius. The unilateral kinematic constraint is removed when its associated constraint reaction force, applied on the roller, is in the direction of the root of the sprocket teeth. In order to improve the numerical...... as continuous force. The model of the roller-chain drive now proposed departs from an earlier model where two contact/impact methods are proposed to describe the contact between the rollers of the chain and the teeth of the sprockets. These different formulations are based on unilateral constraints...

  11. Roughing It Up: Including Jump Components in the Measurement, Modeling and Forecasting of Return Volatility

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Andersen, Torben G.; Diebold, Francis X.

    -Nielsen and Shephard (2004a, 2005) for related bi-power variation measures, the present paper provides a practical and robust framework for non-parametrically measuring the jump component in asset return volatility. In an application to the DM/$ exchange rate, the S&P500 market index, and the 30-year U.S. Treasury......A rapidly growing literature has documented important improvements in financial return volatility measurement and forecasting via use of realized variation measures constructed from high-frequency returns coupled with simple modeling procedures. Building on recent theoretical results in Barndorff...... but sophisticated volatility forecasting model, we find that almost all of the predictability in daily, weekly, and monthly return volatilities comes from the non-jump component. Our results thus set the stage for a number of interesting future econometric developments and important financial applications...

  12. Micromagnetic model for studies on Magnetic Tunnel Junction switching dynamics, including local current density

    Energy Technology Data Exchange (ETDEWEB)

    Frankowski, Marek, E-mail: mfrankow@agh.edu.pl; Czapkiewicz, Maciej; Skowronski, Witold; Stobiecki, Tomasz

    2014-02-15

    We present a model introducing the Landau–Lifshitz–Gilbert equation with a Slonczewski's Spin-Transfer-Torque (STT) component in order to take into account spin polarized current influence on the magnetization dynamics, which was developed as an Object Oriented MicroMagnetic Framework extension. We implement the following computations: magnetoresistance of vertical channels is calculated from the local spin arrangement, local current density is used to calculate the in-plane and perpendicular STT components as well as the Oersted field, which is caused by the vertical current flow. The model allows for an analysis of all listed components separately, therefore, the contribution of each physical phenomenon in dynamic behavior of Magnetic Tunnel Junction (MTJ) magnetization is discussed. The simulated switching voltage is compared with the experimental data measured in MTJ nanopillars.

  13. Solution model of nonlinear integral adjustment including different kinds of observing data with different precisions

    Institute of Scientific and Technical Information of China (English)

    郭金运; 陶华学

    2003-01-01

    In order to process different kinds of observing data with different precisions, a new solution model of nonlinear dynamic integral least squares adjustment was put forward, which is not dependent on their derivatives. The partial derivative of each component in the target function is not computed while iteratively solving the problem. Especially when the nonlinear target function is more complex and very difficult to solve the problem, the method can greatly reduce the computing load.

  14. A Multiscale Progressive Failure Modeling Methodology for Composites that Includes Fiber Strength Stochastics

    Science.gov (United States)

    Ricks, Trenton M.; Lacy, Thomas E., Jr.; Bednarcyk, Brett A.; Arnold, Steven M.; Hutchins, John W.

    2014-01-01

    A multiscale modeling methodology was developed for continuous fiber composites that incorporates a statistical distribution of fiber strengths into coupled multiscale micromechanics/finite element (FE) analyses. A modified two-parameter Weibull cumulative distribution function, which accounts for the effect of fiber length on the probability of failure, was used to characterize the statistical distribution of fiber strengths. A parametric study using the NASA Micromechanics Analysis Code with the Generalized Method of Cells (MAC/GMC) was performed to assess the effect of variable fiber strengths on local composite failure within a repeating unit cell (RUC) and subsequent global failure. The NASA code FEAMAC and the ABAQUS finite element solver were used to analyze the progressive failure of a unidirectional SCS-6/TIMETAL 21S metal matrix composite tensile dogbone specimen at 650 degC. Multiscale progressive failure analyses were performed to quantify the effect of spatially varying fiber strengths on the RUC-averaged and global stress-strain responses and failure. The ultimate composite strengths and distribution of failure locations (predominately within the gage section) reasonably matched the experimentally observed failure behavior. The predicted composite failure behavior suggests that use of macroscale models that exploit global geometric symmetries are inappropriate for cases where the actual distribution of local fiber strengths displays no such symmetries. This issue has not received much attention in the literature. Moreover, the model discretization at a specific length scale can have a profound effect on the computational costs associated with multiscale simulations.models that yield accurate yet tractable results.

  15. A quark model calculation of yy->pipi including final-state interactions

    CERN Document Server

    Blundell, H G; Hay, G; Swanso, E

    2000-01-01

    A quark model calculation of the processes yy->pi+pi- and yy->pipi is performed. At tree level, only charged pions couple to the initial state photons and neutral pions are not exceeded in the final state. However a small but significant cross section is observed. We demonstrate that this may be accounted for by a rotation in isospin space induced by final-state interactions.

  16. Paint Pavement Marking Performance Prediction Model That Includes the Impacts of Snow Removal Operations

    Science.gov (United States)

    2011-03-01

    Hypothesized that snow plows wear down mountain road pavement markings. 2007 Craig et al. -Edge lines degrade slower than center/skip lines 2007...retroreflectivity to create the models. They discovered that paint pavement markings last 80% longer on Portland Cement Concrete than Asphalt Concrete at low AADT...retroreflectivity, while yellow markings lost 21%. Lu and Barter attributed the sizable degradation to snow removal, sand application, and studded

  17. Molten pool-lower head integrity. Heat transfer models including advanced numerical simulations (DNS)

    Energy Technology Data Exchange (ETDEWEB)

    Seiler, J.M.; Bonnet, J.M.; Bernaz, L. [CEA Grenoble (France)

    2001-07-01

    Extensive studies have been performed to investigate the heat transfer within a molten corium pool (homogeneous, stratified and with miscibility gap): Synthesis of heat transfer correlations in molten pool (homogeneous and stratified), Focusing effect in stratified metal layer, DNS analysis of Rayleigh Benard instabilities at the top boundary; interpretation of the different convection regimes and exponents affecting the Rayleigh number in the heat transfer correlations, Molten pool model for corium presenting a miscibility gap. Condition for de-stratification. (authors)

  18. Modeling the Corona and Solar Wind using ADAPT Maps that Include Far-Side Observations

    Science.gov (United States)

    2013-11-01

    document for any purpose other than Government procurement does not in any way obligate the U.S. Government. The fact that the Government formulated...Government’s approval or disapproval of its ideas or findings. Approved for public release; distribution is unlimited. REPORT DOCUMENTATION PAGE...Los Alamos National Laboratory ( LANL ) and the National Solar Observatory (NSO), has developed a model that produces more realistic estimates of the

  19. Numerical modelling of the transport of trace gases including methane in the subsurface of Mars

    Science.gov (United States)

    Stevens, Adam H.; Patel, Manish R.; Lewis, Stephen R.

    2015-04-01

    We model the transport of gas through the martian subsurface in order to quantify the timescales of release of a trace gas with a source at depth using a Fickian model of diffusion through a putative martian regolith column. The model is then applied to the case of methane to determine if diffusive transport of gas can explain previous observations of methane in the martian atmosphere. We investigate which parameters in the model have the greatest effect on transport timescales and show that the calculated diffusivity is very sensitive to the pressure profile of the subsurface, but relatively insensitive to the temperature profile, though diffusive transport may be affected by other temperature dependent properties of the subsurface such as the local vapour pressure. Uncertainties in the structure and physical conditions of the martian subsurface also introduce uncertainties in the timescales calculated. It was found that methane may take several hundred thousand Mars-years to diffuse from a source at depth. Purely diffusive transport cannot explain transient release that varies on timescales of less than one martian year from sources such as serpentinization or methanogenic organisms at depths of more than 2 km. However, diffusion of gas released by the destabilisation of methane clathrate hydrates close to the surface, for example caused by transient mass wasting events or erosion, could produce a rapidly varying flux of methane into the atmosphere of more than 10-3 kg m-2 s-1 over a duration of less than half a martian year, consistent with observations of martian methane variability. Seismic events, magmatic intrusions or impacts could also potentially produce similar patterns of release, but are far more complex to simulate.

  20. Numerical modeling of shallow flows including bottom topography and friction effects

    OpenAIRE

    Lukácová-Medvid'ová, Maria

    2004-01-01

    The aim of the paper is numerical modeling of the shallow water equation with source terms by genuinely multdimensional finite volume evolution Galerkin schemes. The shallow water system, or its one-dimensional analogy the Saint-Venant equation, is used extensively for numerical simulation of natural rivers. Mathematically the shallow water system belongs to the class of balance laws. A special treatment of the source terms describing the bottom topography as well as frictions effects is nece...

  1. A numerical model of the ionosphere, including the E-region above EISCAT

    Directory of Open Access Journals (Sweden)

    P.-Y. Diloy

    Full Text Available It has been previously demonstrated that a two-ion (O+ and H+ 8-moment time-dependent fluid model was able to reproduce correctly the ionospheric structure in the altitude range probed by the EISCAT-VHF radar. In the present study, the model is extended down to the E-region where molecular ion chemistry (NO+ and O+2, essentially prevails over transport; EISCAT-UHF observations confirmed previous theoretical predictions that during events of intense E×B induced convection drifts, molecular ions (mainly NO+ predominate over O+ ions up to altitudes of 300 km. In addition to this extension of the model down to the E-region, the ionization and heating resulting from both solar insolation and particle precipitation is now taken into account in a consistent manner through a complete kinetic transport code. The effects of E×B induced convection drifts on the E- and F-region are presented: the balance between O+ and NO+ ions is drastically affected; the electric field acts to deplete the O+ ion concentration. The [NO+]/[O+] transition altitude varies from 190 km to 320 km as the perpendicular electric field increases from 0 to 100 mV m-1. An interesting additional by-product of the model is that it also predicts the presence of a noticeable fraction of N+ ions in the topside ionosphere in good agreement with Retarding Ion Mass Spectrometer measurements onboard Dynamic Explorer.

  2. A novel model of rheumatoid arthritis-associated interstitial lung disease in SKG mice.

    Science.gov (United States)

    Keith, Rebecca C; Powers, Jennifer L; Redente, Elizabeth F; Sergew, Amen; Martin, Richard J; Gizinski, Alison; Holers, V Michael; Sakaguchi, Shimon; Riches, David W H

    2012-03-01

    Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is associated with increased mortality in up to 10% of patients with rheumatoid arthritis. Lung exposure to cigarette smoke has been implicated in disease development. Little is known about the mechanisms underlying the development of RA-ILD, in part due to the lack of an appropriate mouse model. The objectives of this study were (i) to test the suitability of SKG mice as a model of cellular and fibrotic interstitial pneumonia in the setting of autoimmune arthritis, and (ii) to determine the role of lung injury in the development of arthritis in SKG mice. Lung tissues were evaluated in arthritic SKG mice by quantifying cell accumulation in bronchoalveolar lavage, static compliance, collagen levels, and infiltrating cell phenotypes by flow cytometry and histology. Lung injury was induced by exposure to cigarette smoke or bleomycin. Arthritic SKG mice developed a patchy cellular and fibrotic interstitial pneumonia associated with reduced static compliance, increased collagen levels, and accumulation of inflammatory cells. Infiltrating cells comprised CD4+ T cells, B cells, macrophages, and neutrophils. Chronic exposure to cigarette smoke or initiation of lung injury with bleomycin did not cause arthritis. The pattern of lung disease suggests that arthritic SKG mice represent an authentic model of nonspecific interstitial pneumonia in RA-ILD patients. The lack of arthritis development after cigarette smoke or lung injury suggests that a model where breaches in immunologic tolerance are induced by lung inflammation and injury alone may be overly simplistic.

  3. Climate change impact modelling needs to include cross-sectoral interactions

    Science.gov (United States)

    Harrison, Paula A.; Dunford, Robert W.; Holman, Ian P.; Rounsevell, Mark D. A.

    2016-09-01

    Climate change impact assessments often apply models of individual sectors such as agriculture, forestry and water use without considering interactions between these sectors. This is likely to lead to misrepresentation of impacts, and consequently to poor decisions about climate adaptation. However, no published research assesses the differences between impacts simulated by single-sector and integrated models. Here we compare 14 indicators derived from a set of impact models run within single-sector and integrated frameworks across a range of climate and socio-economic scenarios in Europe. We show that single-sector studies misrepresent the spatial pattern, direction and magnitude of most impacts because they omit the complex interdependencies within human and environmental systems. The discrepancies are particularly pronounced for indicators such as food production and water exploitation, which are highly influenced by other sectors through changes in demand, land suitability and resource competition. Furthermore, the discrepancies are greater under different socio-economic scenarios than different climate scenarios, and at the sub-regional rather than Europe-wide scale.

  4. Kinetic model of water disinfection using peracetic acid including synergistic effects.

    Science.gov (United States)

    Flores, Marina J; Brandi, Rodolfo J; Cassano, Alberto E; Labas, Marisol D

    2016-01-01

    The disinfection efficiencies of a commercial mixture of peracetic acid against Escherichia coli were studied in laboratory scale experiments. The joint and separate action of two disinfectant agents, hydrogen peroxide and peracetic acid, were evaluated in order to observe synergistic effects. A kinetic model for each component of the mixture and for the commercial mixture was proposed. Through simple mathematical equations, the model describes different stages of attack by disinfectants during the inactivation process. Based on the experiments and the kinetic parameters obtained, it could be established that the efficiency of hydrogen peroxide was much lower than that of peracetic acid alone. However, the contribution of hydrogen peroxide was very important in the commercial mixture. It should be noted that this improvement occurred only after peracetic acid had initiated the attack on the cell. This synergistic effect was successfully explained by the proposed scheme and was verified by experimental results. Besides providing a clearer mechanistic understanding of water disinfection, such models may improve our ability to design reactors.

  5. Including A-Priori Assessment of Actual Evapotranspiration for Green Roof Daily Scale Hydrological Modelling

    Directory of Open Access Journals (Sweden)

    Mirka Mobilia

    2017-01-01

    Full Text Available In the last decades, there has been a widespread implementation of Green Infrastructures worldwide. Among these, green roofs appear to be particularly flexible sustainable drainage facilities. To predict their effectiveness for planning purposes, a tool is required that provides information as a function of local meteorological variables. Thus, a relatively simple daily scale, one-dimensional water balance approach has been proposed. The crucial evapotranspiration process, usually considered as a water balance dependent variable, is replaced here by empirical relationships providing an a-priori assessment of soil water losses through actual evapotranspiration. The modelling scheme, which under some simplification can be used without a calibration process, has been applied to experimental runoff data monitored at a green roof located near Bernkastel (Germany, between April 2005 and December 2006. Two different empirical relationships have been used to model actual evapotranspiration, considering a water availability limited and an energy limited scheme. Model errors quantification, ranging from 2% to 40% on the long-term scale and from 1% to 36% at the event scale, appear strongly related to the particularly considered relationship.

  6. Modelling topical photodynamic therapy treatment including the continuous production of Protoporphyrin IX

    Science.gov (United States)

    Campbell, C. L.; Brown, C. T. A.; Wood, K.; Moseley, H.

    2016-11-01

    Most existing theoretical models of photodynamic therapy (PDT) assume a uniform initial distribution of the photosensitive molecule, Protoporphyrin IX (PpIX). This is an adequate assumption when the prodrug is systematically administered; however for topical PDT this is no longer a valid assumption. Topical application and subsequent diffusion of the prodrug results in an inhomogeneous distribution of PpIX, especially after short incubation times, prior to light illumination. In this work a theoretical simulation of PDT where the PpIX distribution depends on the incubation time and the treatment modality is described. Three steps of the PpIX production are considered. The first is the distribution of the topically applied prodrug, the second in the conversion from the prodrug to PpIX and the third is the light distribution which affects the PpIX distribution through photobleaching. The light distribution is modelled using a Monte Carlo radiation transfer model and indicates treatment depths of around 2 mm during daylight PDT and approximately 3 mm during conventional PDT. The results suggest that treatment depths are not only limited by the light penetration but also by the PpIX distribution.

  7. A stepped leader model for lightning including charge distribution in branched channels

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Wei; Zhang, Li [School of Electrical Engineering, Shandong University, Jinan 250061 (China); Li, Qingmin, E-mail: lqmeee@ncepu.edu.cn [Beijing Key Lab of HV and EMC, North China Electric Power University, Beijing 102206 (China); State Key Lab of Alternate Electrical Power System with Renewable Energy Sources, Beijing 102206 (China)

    2014-09-14

    The stepped leader process in negative cloud-to-ground lightning plays a vital role in lightning protection analysis. As lightning discharge usually presents significant branched or tortuous channels, the charge distribution along the branched channels and the stochastic feature of stepped leader propagation were investigated in this paper. The charge density along the leader channel and the charge in the leader tip for each lightning branch were approximated by introducing branch correlation coefficients. In combination with geometric characteristics of natural lightning discharge, a stochastic stepped leader propagation model was presented based on the fractal theory. By comparing simulation results with the statistics of natural lightning discharges, it was found that the fractal dimension of lightning trajectory in simulation was in the range of that observed in nature and the calculation results of electric field at ground level were in good agreement with the measurements of a negative flash, which shows the validity of this proposed model. Furthermore, a new equation to estimate the lightning striking distance to flat ground was suggested based on the present model. The striking distance obtained by this new equation is smaller than the value estimated by previous equations, which indicates that the traditional equations may somewhat overestimate the attractive effect of the ground.

  8. Numerical Modeling of the Surface Fatigue Crack Propagation Including the Closure Effect

    Science.gov (United States)

    Guchinsky, Ruslan; Petinov, Sergei

    2016-01-01

    Presently modeling of surface fatigue crack growth for residual life assessment of structural elements is almost entirely based on application of the Linear Elastic Fracture Mechanics (LEFM). Generally, it is assumed that the crack front does not essentially change its shape, although it is not always confirmed by experiment. Furthermore, LEFM approach cannot be applied when the stress singularity vanishes due to material plasticity, one of the leading factors associated with the material degradation and fracture. Also, evaluation of stress intensity factors meets difficulties associated with changes in the stress state along the crack front circumference. An approach proposed for simulation the evolution of surface cracks based on application of the Strain-life criterion for fatigue failure and of the finite element modeling of damage accumulation. It takes into account the crack closure effect, the nonlinear behavior of damage accumulation and material compliance increasing due to the damage advance. The damage accumulation technique was applied to model the semi-elliptical crack growth from the initial defect in the steel compact specimen. The results of simulation are in good agreement with the published experimental data.

  9. Developing parameters for multi-mode ambient air models including the nanometer mode

    Science.gov (United States)

    Tronville, Paolo; Rivers, Richard

    2017-06-01

    The particle count, surface and mass in an occupied space can be modeled when the HVAC system airflows are known, along with the particle-size distribution for outdoor air, internal generation rates as a function of particle size, and the efficiency as a function of particle size for filters present. Outdoor air particle-size distribution is rarely available, but measures of particle mass concentration, PM2.5 and PM10, are often available for building locations. Outdoor air aerosol size distributions are well modeled by sums of two or three log-normal distributions, with essentially all mass in two larger modes. Studies have also shown that some mode parameters are, in general, related by simple functions. This paper shows how these relationships can be combined with known characteristics of PM2.5 and PM10 samplers to create reasonable inclusive models of outdoor air aerosol-size distributions. This information plus knowledge of indoor particle generation allows calculation of aerosol mass in occupied spaces. Estimation of parameters of aerosol modes with sizes below100 nm and measurement of filter efficiencies in that range are described.

  10. Galactic habitable zone around M and FGK stars with chemical evolution models that include dust

    Science.gov (United States)

    Spitoni, E.; Gioannini, L.; Matteucci, F.

    2017-09-01

    Context. The Galactic habitable zone is defined as the region with a metallicity that is high enough to form planetary systems in which Earth-like planets could be born and might be capable of sustaining life. Life in this zone needs to survive the destructive effects of nearby supernova explosion events. Aims: Galactic chemical evolution models can be useful tools for studying the galactic habitable zones in different systems. Our aim here is to find the Galactic habitable zone using chemical evolution models for the Milky Way disk, adopting the most recent prescriptions for the evolution of dust and for the probability of finding planetary systems around M and FGK stars. Moreover, for the first time, we express these probabilities in terms of the dust-to-gas ratio of the interstellar medium in the solar neighborhood as computed by detailed chemical evolution models. Methods: At a fixed Galactic time and Galactocentric distance, we determined the number of M and FGK stars that host earths (but no gas giant planets) that survived supernova explosions, using the formalism of our Paper I. Results: The probabilities of finding terrestrial planets but not gas giant planets around M stars deviate substantially from the probabilities around FGK stars for supersolar values of [Fe/H]. For both FGK and M stars, the maximum number of stars hosting habitable planets is at 8 kpc from the Galactic Center when destructive effects by supernova explosions are taken into account. Currently, M stars with habitable planets are ≃10 times more frequent than FGK stars. Moreover, we provide a sixth-order polynomial fit (and a linear fit, but that is more approximated) for the relation found with chemical evolution models in the solar neighborhood between the [Fe/H] abundances and the dust-to-gas ratio. Conclusions: The most likely Galactic zone in which to find terrestrial habitable planets around M and FGK stars is the annular 2 kpc wide region that is centered at 8 kpc from the

  11. Comparison of lead isotopes with source apportionment models, including SOM, for air particulates.

    Science.gov (United States)

    Gulson, Brian; Korsch, Michael; Dickson, Bruce; Cohen, David; Mizon, Karen; Davis, J Michael

    2007-08-01

    We have measured high precision lead isotopes in PM(2.5) particulates from a highly-trafficked site (Mascot) and rural site (Richmond) in the Sydney Basin, New South Wales, Australia to compare with isotopic data from total suspended particulates (TSP) from other sites in the Sydney Basin and evaluate relationships with source fingerprints obtained from multi-element PM(2.5) data. The isotopic data for the period 1998 to 2004 show seasonal peaks and troughs that are more pronounced in the rural site for the PM(2.5).samples but are consistent with the TSP. The Self Organising Map (SOM) method has been applied to the multi-element PM(2.5) data to evaluate its use in obtaining fingerprints for comparison with standard statistical procedures (ANSTO model). As seasonal effects are also significant for the multi-element data, the SOM modelling is reported as site and season dependent. At the Mascot site, the ANSTO model exhibits decreasing (206)Pb/(204)Pb ratios with increasing contributions of fingerprints for "secondary smoke" (industry), "soil", "smoke" and "seaspray". Similar patterns were shown by SOM winter fingerprints for both sites. At the rural site, there are large isotopic variations but for the majority of samples these are not associated with increased contributions from the main sources with the ANSTO model. For two winter sampling times, there are increased contributions from "secondary industry", "smoke", "soil" and seaspray with one time having a source or sources of Pb similar to that of Mascot. The only positive relationship between increasing (206)Pb/(204)Pb ratio and source contributions is found at the rural site using the SOM summer fingerprints, both of which show a significant contribution from sulphur. Several of the fingerprints using either model have significant contributions from black carbon (BC) and/or sulphur (S) that probably derive from diesel fuels and industrial sources. Increased contributions from sources with the SOM summer

  12. Spontaneous, Immune-Mediated Gastric Inflammation in SAMP1/YitFc Mice, a Model of Crohn’s-Like Gastritis

    Science.gov (United States)

    Reuter, Brian K.; Pastorelli, Luca; Brogi, Marco; Garg, Rekha R.; McBride, James A.; Rowlett, Robert M.; Arrieta, Marie C.; Wang, Xiao-Ming; Keller, Erik J.; Feldman, Sanford H.; Mize, James R.; Cominelli, Fabio; Meddings, Jonathan B.; Pizarro, Theresa T.

    2011-01-01

    Background & Aims Crohn’s disease (CD) can develop in any region of the gastrointestinal tract, including the stomach. The etiology and pathogenesis of Crohn’s gastritis are poorly understood, treatment approaches are limited, and there are not many suitable animal models for study. We characterized the features and mechanisms of chronic gastritis in SAMP1/YitFc (SAMP) mice, a spontaneous model of CD-like ileitis, along with possible therapeutic approaches. Methods Stomachs from specific pathogen-free and germ-free SAMP and AKR mice (controls) were evaluated histologically; the presence of Helicobacter spp. was tested in fecal pellets by PCR analysis. In vivo gastric permeability was quantified by fractional excretion of sucrose and epithelial tight junction protein expression was measured by quantitative reverse transcription PCR analysis. The effects of a proton pump inhibitor (PPI) or corticosteroids were measured and the ability of pathogenic immune cells to mediate gastritis was assessed in adoptive transfer experiments. Results SAMP mice developed Helicobacter-negative gastritis, characterized by aggregates of mononuclear cells, diffuse accumulation of neutrophils, and disruption of epithelial architecture; SAMP mice also had increased in gastric permeability compared with controls, without alterations in expression of tight junction proteins. The gastritis and associated permeability defect observed in SAMP mice were independent of bacterial colonization and reduced by administration of corticosteroids but not a PPI. CD4+ T cells isolated from draining mesenteric lymph nodes of SAMP mice were sufficient to induce gastritis in recipient SCID mice. Conclusions In SAMP mice, gastritis develops spontaneously and has many features of CD-like ileitis. These mice are a useful model to study Helicobacter-negative, immune-mediated Crohn’s gastritis. PMID:21704001

  13. Protective Effects of Scrophularia Striata in Ovalbumin-induced Mice Asthma Model

    Directory of Open Access Journals (Sweden)

    Abbas Azadmehr

    2013-07-01

    Full Text Available Background:Scrophularia striata Boiss. (Scrophulariaceae is a plant growing in the northeastern part of Iran and being used as a traditional herb for various inflammatory disorders.This study was designed to investigate the protective effects of the Scrophularia striata extract in Ovalbumin (OVA induced-asthma mice model.Methods:OVA-sensitized mice were intrapritonealy treated with two doses (100 and 200 mg/kg of the extract on days 8 to 14 separately. Broncoalveolar lavage fluids (BALF was collected 48 h after the final OVA challenge and then the number of eosinophils and other inflammatory cells were assessed by direct microscopic counting. In addition, total immunoglubolin (Ig E and OVA-specific IgE levels in serum, IL-4 and IL-5 cytokines in BALF were determined by Enzyme-Linked Immunosorbent Assay. Moreover, phytochemical assay by thin layer chromatography (TLC and the 2, 2 diphenyl-1-picrylhydrazyl (DPPH were used to evaluate the main compounds and the antioxidant capacity of the plant extract, respectively.Results:The results showed that the main components; including flavonoids, phenolic compounds and phenyl propanoids were presented in the S. striata extract. In addition, the treatment with extract significantly reduced the number of inflammatory cells and suppressed T-helper 2 (Th2 cytokines including IL-4 and IL-5 in BALF. Also, total IgE and OVA-specific IgE levels in the serum decreased.Conclusion:Collectively, it is concluded that the extract has the potential to modulate the Th2 cytokines and could be used as immunomodulatory agent in the treatment of allergic asthma.

  14. Modeling appetitive Pavlovian-instrumental interactions in mice.

    Science.gov (United States)

    O'Connor, Eoin C; Stephens, David N; Crombag, Hans S

    2010-10-01

    In appetitive Pavlovian associative learning, a stimulus (conditioned stimulus, CS) that has been associated with the delivery of a reinforcing event (unconditioned stimulus, US; e.g., food) can subsequently elicit or modulate goal-directed instrumental behaviors. For example, a Pavlovian CS can serve to reinforce (novel) instrumental behavior (conditioned reinforcement or CRf), or it can energize and potentiate ongoing instrumental responses when presented non-contingently (Pavlovian-instrumental transfer or PIT). Notably, these different effects of a Pavlovian CS on instrumental behavior are mediated by dissociable psychological and neurobiological mechanisms. Given the critical role that Pavlovian-instrumental interactions play in regulating motivated behavior and maladaptive manifestations of motivation such as eating disorders and addictions, understanding the underlying psychological and neurobiological mechanisms will be important. This unit describes behavioral protocols that produce robust and reliable PIT and CRf in mice and that open the door for future studies using transgenic approaches into the molecular mechanisms underlying associative learning and motivation.

  15. Mottled Mice and Non-Mammalian Models of Menkes Disease

    DEFF Research Database (Denmark)

    Lenartowicz, Małgorzata; Krzeptowski, Wojciech; Lipiński, Paweł

    2015-01-01

    role in the maintenance of copper homeostasis in cells of the whole body. ATP7A participates in copper absorption in the small intestine and in copper transport to the central nervous system (CNS) across the blood-brain-barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB). Cu is essential...... for synaptogenesis and axonal development. In cells, ATP7A participates in the incorporation of copper into Cu-dependent enzymes during the course of its maturation in the secretory pathway. There is a high degree of homology (>80%) between the human ATP7A and murine Atp7a genes. Mice with mutations in the Atp7a......Menkes disease is a multi-systemic copper metabolism disorder caused by mutations in the X-linked ATP7A gene and characterized by progressive neurodegeneration and severe connective tissue defects. The ATP7A protein is a copper (Cu)-transporting ATPase expressed in all tissues and plays a critical...

  16. The mouse as a model for understanding chronic diseases of aging: the histopathologic basis of aging in inbred mice

    Directory of Open Access Journals (Sweden)

    David Harrison

    2011-06-01

    Full Text Available Inbred mice provide a unique tool to study aging populations because of the genetic homogeneity within an inbred strain, their short life span, and the tools for analysis which are available. A large-scale longitudinal and cross-sectional aging study was conducted on 30 inbred strains to determine, using histopathology, the type and diversity of diseases mice develop as they age. These data provide tools that when linked with modern in silico genetic mapping tools, can begin to unravel the complex genetics of many of the common chronic diseases associated with aging in humans and other mammals. In addition, novel disease models were discovered in some strains, such as rhabdomyosarcoma in old A/J mice, to diseases affecting many but not all strains including pseudoxanthoma elasticum, pulmonary adenoma, alopecia areata, and many others. This extensive data set is now available online and provides a useful tool to help better understand strain-specific background diseases that can complicate interpretation of genetically engineered mice and other manipulatable mouse studies that utilize these strains.

  17. Able but unintelligent: including positively stereotyped black subgroups in the stereotype content model.

    Science.gov (United States)

    Walzer, Amy S; Czopp, Alexander M

    2011-01-01

    The stereotype content model (SCM) posits that warmth and competence are the key components underlying judgments about social groups. Because competence can encompass different components (e.g., intelligence, talent) different group members may be perceived to be competent for different reasons. Therefore, we believe it may be important to specify the type of competence being assessed when examining perceptions of groups that are positively stereotyped (i.e., Black athletes and musical Blacks). Consistent with the SCM, these subgroups were perceived as high in competence-talent but not in competence-intelligence and low in warmth. Both the intelligence and talent frame of competence fit in the SCM's social structural hypothesis.

  18. Microregion model of a contact line including evaporation, kinetics and slip

    Science.gov (United States)

    Anderson, Daniel; Janecek, Vladislav

    2016-11-01

    We consider the evaporation of a liquid on a uniformly heated solid substrate. In the framework of lubrication theory we consider hydrodynamics, heat conduction, phase change, evaporation kinetics, and slip. Our model focuses only on the contact line 'inner' region which allows us to quantify the impact of evaporation on the apparent contact angle and microregion heat transfer. The linearized problem with respect to the substrate overheating is solved analytically. The analytical solutions are compared with full numerical solutions and to predictions of Hocking.

  19. Mathematical modeling of the hypothalamic–pituitary–adrenal gland (HPA) axis, including hippocampal mechanisms

    DEFF Research Database (Denmark)

    Andersen, Morten; Vinther, Frank; Ottesen, Johnny T.

    2013-01-01

    non-negative and bounded, which can be interpreted as a mathematical formulation of homeostasis. No oscillating solutions are present when using physiologically reasonable parameter values. This indicates that the ultradian rhythm originate from different mechanisms.Using physiologically reasonable......This paper presents a mathematical model of the HPA axis. The HPA axis consists of the hypothalamus, the pituitary and the adrenal glands in which the three hormones CRH, ACTH and cortisol interact through receptor dynamics. Furthermore, it has been suggested that receptors in the hippocampus have...

  20. Nuclear monopole charge form factor calculation for relativistic models including center-of-mass corrections

    Energy Technology Data Exchange (ETDEWEB)

    Avancini, S.S.; Marinelli, J.R. [Universidade Federal de Santa Catarina Florianopolis, Depto de Fisica - CFM, Florianopolis (Brazil); Carlson, B.V. [Instituto Tecnologico de Aeronautica, Sao Jose dos Campos (Brazil)

    2013-06-15

    Relativistic models for finite nuclei contain spurious center-of-mass motion in most applications for the nuclear many-body problem, where the nuclear wave function is taken as a single Slater determinant within a space-fixed frame description. We use the Peierls-Yoccoz projection method, previously developed for relativistic approaches together with a reparametrization of the coupling constants that fits binding energies and charge radius and apply our results to calculate elastic electron scattering monopole charge form factors for light nuclei. (orig.)

  1. Double pendulum model for a tennis stroke including a collision process

    Science.gov (United States)

    Youn, Sun-Hyun

    2015-10-01

    By means of adding a collision process between the ball and racket in the double pendulum model, we analyzed the tennis stroke. The ball and the racket system may be accelerated during the collision time; thus, the speed of the rebound ball does not simply depend on the angular velocity of the racket. A higher angular velocity sometimes gives a lower rebound ball speed. We numerically showed that the proper time-lagged racket rotation increased the speed of the rebound ball by 20%. We also showed that the elbow should move in the proper direction in order to add the angular velocity of the racket.

  2. Modeling the elastic behavior of ductile cast iron including anisotropy in the graphite nodules

    DEFF Research Database (Denmark)

    Andriollo, Tito; Thorborg, Jesper; Hattel, Jesper Henri

    2016-01-01

    This paper presents a micro-mechanical approach to model the intrinsic elastic anisotropy of the graphite particles in ductile iron. Contrary to most of the published works in the field, the constitutive behavior is directly derived on the basis of the nodule characteristic internal structure......, composed of graphite platelets arranged into conical sectors. In this way, the large uncertainty traditionally associated with local mechanical measurements of micro-hardness is eliminated. The proposed anisotropic description is validated by simulating the macroscopic ductile iron elastic response...

  3. Craniofacial Statistical Deformation Models of Wild-type mice and Crouzon mice

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Darvann, Tron Andre; Ersbøll, Bjarne Kjær

    2007-01-01

    Crouzon syndrome is characterised by the premature fusion of cranial sutures and synchondroses leading to craniofacial growth disturbances. The gene causing the syndrome was discovered approximately a decade ago and recently the first mouse model of the syndrome was generated. In this study, a se...

  4. From Mice to Men: research models of developmental programming.

    Science.gov (United States)

    Rabadán-Diehl, C; Nathanielsz, P

    2013-02-01

    Developmental programming can be defined as a response to a specific challenge to the mammalian organism during a critical developmental time window that alters the trajectory of development with persistent effects on offspring phenotype and predisposition to future illness. We focus on the need for studies in relevant, well-characterized animal models in the context of recent research discoveries on the challenges, mechanisms and outcomes of developmental programming. We discuss commonalities and differences in general principles of developmental programming as they apply to several species, including humans. The consequences of these differences are discussed. Obesity, metabolic disorders and cardiovascular diseases are associated with the highest percentage of morbidity and mortality worldwide. Although many of the causes are associated with lifestyle, high-energy diets and lack of physical activity, recent evidence has linked developmental programming to the epidemic of metabolic diseases. A better understanding of comparative systems physiology of mother, fetus and neonate using information provided by rapid advances in molecular biology has the potential to improve the lifetime health of future generations by providing better women's health, diagnostic tools and preventative and therapeutic interventions in individuals exposed during their development to programming influences.

  5. Including Antenna Models in Microwave Imaging for Breast-Cancer Screening

    DEFF Research Database (Denmark)

    Rubæk, Tonny; Meincke, Peter

    2006-01-01

    Microwave imaging is emerging as a tool for screening for breast cancer, but the lack of methods for including the characteristics of the antennas of the imaging systems in the imaging algorithms limits their performance. In this paper, a method for incorporating the full antenna characteristics......, in terms of the transmission-matrix representation, in a frequency-domain imaging algorithm is presented. The algorithm is tested on a simulation of the Physical-Anomaly Tomography (PAT) scanner imaging system developed at the Technical University of Denmark and is shown to have superior performance when...

  6. Modeling psychotic and cognitive symptoms of affective disorders: Disrupted latent inhibition and reversal learning deficits in highly stress reactive mice.

    Science.gov (United States)

    Knapman, A; Heinzmann, J-M; Holsboer, F; Landgraf, R; Touma, C

    2010-09-01

    Increased stress reactivity has repeatedly been reported in patients suffering from psychiatric diseases including schizophrenia and major depression. These disorders also have other symptoms in common, such as cognitive deficits and psychotic-like behavior. We have therefore investigated if increased stress reactivity is associated with these phenotypic endpoints in an animal model of affective disorders. The stress reactivity mouse model used in this study consists of three CD-1-derived mouse lines, that have been selectively bred for high (HR), intermediate (IR) or low (LR) stress reactivity. Male mice from these three breeding lines were subjected to a reversal learning task and latent inhibition (Li) was assessed using a conditioned taste aversion paradigm. Furthermore, as the dopaminergic system is involved in both Li and reversal learning, the dopamine 1 receptor (D1R), dopamine 2 receptor (D2R) and dopamine transporter (DAT) mRNA expression levels were assessed in relevant brain areas of these animals. The results demonstrate that HR mice show perseveration in the reversal learning task and have disrupted Li. Furthermore, compared to LR mice, HR mice have decreased D2R mRNA levels in the ventral tegmental area, as well as decreased D1R mRNA levels in the cingulate cortex, and an increased expression of D2R mRNA in the nucleus accumbens. Taken together, these results demonstrate that the HR mice display cognitive deficits associated with psychotic-like behavior, similar to those observed in patients suffering from schizophrenia and major depression and could be utilized in the search for better treatment strategies for these symptoms of psychiatric disorders.

  7. The evolution of massive stars including mass loss - Presupernova models and explosion

    Science.gov (United States)

    Woosley, S. E.; Langer, Norbert; Weaver, Thomas A.

    1993-01-01

    The evolution of massive stars of 35, 40, 60, and 85 solar masses is followed through all stages of nuclear burning to the point of Fe core collapse. Critical nuclear reaction and mass-loss rates are varied. Efficient mass loss during the Wolf-Rayet (WR) stage is likely to lead to final masses as small as 4 solar masses. For a reasonable parameterization of the mass loss, there may be convergence of all WR stars, both single and in binaries, to a narrow band of small final masses. Our representative model, a 4.25 solar-mass WR presupernova derived from a 60 solar mass star, is followed through a simulated explosion, and its explosive nucleosynthesis and light curve are determined. Its properties are similar to those observed in Type Ib supernovae. The effects of the initial mass and mass loss on the presupernova structure of small mass WR models is also explored. Important properties of the presupernova star and its explosion can only be obtained by following the complete evolution starting on the main sequence.

  8. Model for external influences on cellular signal transduction pathways including cytosolic calcium oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Eichwald, C.; Kaiser, F. [Technical Univ. of Darmstadt (Germany)

    1995-06-01

    Experiments on the effects of extremely-low-frequency (ELF) electric and magnetic fields on cells of the immune system, T-lymphocytes in particular, suggest that the external field interacts with the cell at the level of intracellular signal transduction pathways. These are directly connected with changes in the calcium-signaling processes of the cell. Based on these findings, a theoretical model for receptor-controlled cytosolic calcium oscillations and for external influences on the signal transduction pathway is presented. The authors discuss the possibility that the external field acts on the kinetics of the signal transduction between the activated receptors at the cell membrane and the G-proteins. It is shown that, depending on the specific combination of cell internal biochemical and external physical parameters, entirely different responses of the cell can occur. The authors compare the effects of a coherent (periodic) modulation and of incoherent perturbations (noise). The model and the calculations are based on the theory of self-sustained, nonlinear oscillators. It is argued that these systems form an ideal basis for information-encoding processes in biological systems.

  9. An Improved Heat Budget Estimation Including Bottom Effects for General Ocean Circulation Models

    Science.gov (United States)

    Carder, Kendall; Warrior, Hari; Otis, Daniel; Chen, R. F.

    2001-01-01

    This paper studies the effects of the underwater light field on heat-budget calculations of general ocean circulation models for shallow waters. The presence of a bottom significantly alters the estimated heat budget in shallow waters, which affects the corresponding thermal stratification and hence modifies the circulation. Based on the data collected during the COBOP field experiment near the Bahamas, we have used a one-dimensional turbulence closure model to show the influence of the bottom reflection and absorption on the sea surface temperature field. The water depth has an almost one-to-one correlation with the temperature rise. Effects of varying the bottom albedo by replacing the sea grass bed with a coral sand bottom, also has an appreciable effect on the heat budget of the shallow regions. We believe that the differences in the heat budget for the shallow areas will have an influence on the local circulation processes and especially on the evaporative and long-wave heat losses for these areas. The ultimate effects on humidity and cloudiness of the region are expected to be significant as well.

  10. On the modelling of semi-insulating GaAs including surface tension and bulk stresses

    Energy Technology Data Exchange (ETDEWEB)

    Dreyer, W.; Duderstadt, F.

    2004-07-01

    Necessary heat treatment of single crystal semi-insulating Gallium Arsenide (GaAs), which is deployed in micro- and opto- electronic devices, generate undesirable liquid precipitates in the solid phase. The appearance of precipitates is influenced by surface tension at the liquid/solid interface and deviatoric stresses in the solid. The central quantity for the description of the various aspects of phase transitions is the chemical potential, which can be additively decomposed into a chemical and a mechanical part. In particular the calculation of the mechanical part of the chemical potential is of crucial importance. We determine the chemical potential in the framework of the St. Venant-Kirchhoff law which gives an appropriate stress/strain relation for many solids in the small strain regime. We establish criteria, which allow the correct replacement of the St. Venant-Kirchhoff law by the simpler Hooke law. The main objectives of this study are: (i) We develop a thermo-mechanical model that describes diffusion and interface motion, which both are strongly influenced by surface tension effects and deviatoric stresses. (ii) We give an overview and outlook on problems that can be posed and solved within the framework of the model. (iii) We calculate non-standard phase diagrams, i.e. those that take into account surface tension and non-deviatoric stresses, for GaAs above 786 C, and we compare the results with classical phase diagrams without these phenomena. (orig.)

  11. Grids of stellar models including second harmonic and colours: Solar composition

    CERN Document Server

    Yildiz, Mutlu

    2015-01-01

    Grids of stellar evolution are required in many fields of astronomy/astrophysics, such as planet hosting stars, binaries, clusters, chemically peculiar stars, etc. In this study, a grid of stellar evolution models with updated ingredients and {recently determined solar abundaces} is presented. The solar values for the initial abundances of hydrogen, heavy elements and mixing-length parameter are 0.0172, 0.7024 and 1.98, respectively. The mass step is small enough (0.01 M$_\\odot$) that interpolation for a given star mass is not required. The range of stellar mass is 0.74 to 10.00 M$_\\odot$. We present results in different forms of tables for easy and general application. The second stellar harmonic, required for analysis of apsidal motion of eclipsing binaries, is also listed. We also construct rotating models to determine effect of rotation on stellar structure and derive fitting formula for luminosity, radius and the second stellar harmonic as a function of rotational parameter. We also compute and list colo...

  12. Analysis of the R-symmetric supersymmetric models including quantum corrections

    CERN Document Server

    Kotlarski, Wojciech

    2016-01-01

    We study the Minimal R-symmetric Supersymmetric Standard Model (MRSSM) at the quantum level. The thesis consists of two parts. First one treats about the electroweak sector of the model. Among others, it identifies the parameter region allowed by the electroweak precision observables. Since the MRSSM contains an $SU(2)_L$-triplet with a non-zero vacuum expectation value the emphasis is put on the calculation of the $W$ boson mass. To that end, a full one-loop calculation of $m_W$ augmented with the leading two-loop SM result is presented. The region is then checked against the measurement of the Higgs boson mass. For this, the full one-loop and leading two-loop corrections to the Higgs boson mass in the MRSSM are calculated. Devised benchmark points, consistent with both of these observables, are shown to fulfill also a number of additional experimental constraints like properties of the Higgs boson(s), $b$-physics observables and vacuum stability. Correlating all of these observables allows to put bounds on ...

  13. Description and Application of A Model of Seepage under A Weir Including Mechanical Clogging

    Directory of Open Access Journals (Sweden)

    Sroka Zbigniew

    2014-07-01

    Full Text Available The paper discusses seepage flow under a damming structure (a weir in view of mechanical clogging in a thin layer at the upstream site. It was assumed that in this layer flow may be treated as one-dimensional (perpendicular to the layer, while elsewhere flow was modelled as two-dimensional. The solution in both zones was obtained in the discrete form using the finite element method and the Euler method. The effect of the clogging layer on seepage flow was modelled using the third kind boundary condition. Seepage parameters in the clogging layer were estimated based on laboratory tests conducted by Skolasińska [2006]. Typical problem was taken to provide simulation and indicate how clogging affects the seepage rate and other parameters of the flow. Results showed that clogging at the upstream site has a significant effect on the distribution of seepage velocity and hydraulic gradients. The flow underneath the structure decreases with time, but these changes are relatively slow.

  14. Simulation of the contraction of the ventricles in a human heart model including atria and pericardium.

    Science.gov (United States)

    Fritz, Thomas; Wieners, Christian; Seemann, Gunnar; Steen, Henning; Dössel, Olaf

    2014-06-01

    During the contraction of the ventricles, the ventricles interact with the atria as well as with the pericardium and the surrounding tissue in which the heart is embedded. The atria are stretched, and the atrioventricular plane moves toward the apex. The atrioventricular plane displacement (AVPD) is considered to be a major contributor to the ventricular function, and a reduced AVPD is strongly related to heart failure. At the same time, the epicardium slides almost frictionlessly on the pericardium with permanent contact. Although the interaction between the ventricles, the atria and the pericardium plays an important role for the deformation of the heart, this aspect is usually not considered in computational models. In this work, we present an electromechanical model of the heart, which takes into account the interaction between ventricles, pericardium and atria and allows to reproduce the AVPD. To solve the contact problem of epicardium and pericardium, a contact handling algorithm based on penalty formulation was developed, which ensures frictionless and permanent contact. Two simulations of the ventricular contraction were conducted, one with contact handling of pericardium and heart and one without. In the simulation with contact handling, the atria were stretched during the contraction of the ventricles, while, due to the permanent contact with the pericardium, their volume increased. In contrast to that, in the simulations without pericardium, the atria were also stretched, but the change in the atrial volume was much smaller. Furthermore, the pericardium reduced the radial contraction of the ventricles and at the same time increased the AVPD.

  15. Effect of neurosteroids on a model lipid bilayer including cholesterol: An Atomic Force Microscopy study.

    Science.gov (United States)

    Sacchi, Mattia; Balleza, Daniel; Vena, Giulia; Puia, Giulia; Facci, Paolo; Alessandrini, Andrea

    2015-05-01

    Amphiphilic molecules which have a biological effect on specific membrane proteins, could also affect lipid bilayer properties possibly resulting in a modulation of the overall membrane behavior. In light of this consideration, it is important to study the possible effects of amphiphilic molecule of pharmacological interest on model systems which recapitulate some of the main properties of the biological plasma membranes. In this work we studied the effect of a neurosteroid, Allopregnanolone (3α,5α-tetrahydroprogesterone or Allo), on a model bilayer composed by the ternary lipid mixture DOPC/bSM/chol. We chose ternary mixtures which present, at room temperature, a phase coexistence of liquid ordered (Lo) and liquid disordered (Ld) domains and which reside near to a critical point. We found that Allo, which is able to strongly partition in the lipid bilayer, induces a marked increase in the bilayer area and modifies the relative proportion of the two phases favoring the Ld phase. We also found that the neurosteroid shifts the miscibility temperature to higher values in a way similarly to what happens when the cholesterol concentration is decreased. Interestingly, an isoform of Allo, isoAllopregnanolone (3β,5α-tetrahydroprogesterone or isoAllo), known to inhibit the effects of Allo on GABAA receptors, has an opposite effect on the bilayer properties.

  16. Thermo-mechanical modeling of turbulent heat transfer in gas-solid flows including particle collisions

    Energy Technology Data Exchange (ETDEWEB)

    Mansoori, Zohreh; Saffar-Avval, Majid; Basirat-Tabrizi, Hassan; Ahmadi, Goodarz; Lain, Santiago

    2002-12-01

    A thermo-mechanical turbulence model is developed and used for predicting heat transfer in a gas-solid flow through a vertical pipe with constant wall heat flux. The new four-way interaction model makes use of the thermal k{sub {theta}}-{tau}{sub {theta}} equations, in addition to the hydrodynamic k-{tau} transport, and accounts for the particle-particle and particle-wall collisions through a Eulerian/Lagrangian formulation. The simulation results indicate that the level of thermal turbulence intensity and the heat transfer are strongly affected by the particle collisions. Inter-particle collisions attenuate the thermal turbulence intensity near the wall but somewhat amplify the temperature fluctuations in the pipe core region. The hydrodynamic-to-thermal times-scale ratio and the turbulent Prandtl number in the region near the wall increase due to the inter-particle collisions. The results also show that the use of a constant or the single-phase gas turbulent Prandtl number produces error in the thermal eddy diffusivity and thermal turbulent intensity fields. Simulation results also indicate that the inter-particle contact heat conduction during collision has no significant effect in the range of Reynolds number and particle diameter studied.

  17. The evolution of massive stars including mass loss - Presupernova models and explosion

    Science.gov (United States)

    Woosley, S. E.; Langer, Norbert; Weaver, Thomas A.

    1993-01-01

    The evolution of massive stars of 35, 40, 60, and 85 solar masses is followed through all stages of nuclear burning to the point of Fe core collapse. Critical nuclear reaction and mass-loss rates are varied. Efficient mass loss during the Wolf-Rayet (WR) stage is likely to lead to final masses as small as 4 solar masses. For a reasonable parameterization of the mass loss, there may be convergence of all WR stars, both single and in binaries, to a narrow band of small final masses. Our representative model, a 4.25 solar-mass WR presupernova derived from a 60 solar mass star, is followed through a simulated explosion, and its explosive nucleosynthesis and light curve are determined. Its properties are similar to those observed in Type Ib supernovae. The effects of the initial mass and mass loss on the presupernova structure of small mass WR models is also explored. Important properties of the presupernova star and its explosion can only be obtained by following the complete evolution starting on the main sequence.

  18. Three-Dimensional Magnetohydrodynamic Modeling of the Solar Wind Including Pickup Protons and Turbulence Transport

    Science.gov (United States)

    Usmanov, Arcadi V.; Goldstein, Melvyn L.; Matthaeus, William H.

    2012-01-01

    To study the effects of interstellar pickup protons and turbulence on the structure and dynamics of the solar wind, we have developed a fully three-dimensional magnetohydrodynamic solar wind model that treats interstellar pickup protons as a separate fluid and incorporates the transport of turbulence and turbulent heating. The governing system of equations combines the mean-field equations for the solar wind plasma, magnetic field, and pickup protons and the turbulence transport equations for the turbulent energy, normalized cross-helicity, and correlation length. The model equations account for photoionization of interstellar hydrogen atoms and their charge exchange with solar wind protons, energy transfer from pickup protons to solar wind protons, and plasma heating by turbulent dissipation. Separate mass and energy equations are used for the solar wind and pickup protons, though a single momentum equation is employed under the assumption that the pickup protons are comoving with the solar wind protons.We compute the global structure of the solar wind plasma, magnetic field, and turbulence in the region from 0.3 to 100 AU for a source magnetic dipole on the Sun tilted by 0 deg - .90 deg and compare our results with Voyager 2 observations. The results computed with and without pickup protons are superposed to evaluate quantitatively the deceleration and heating effects of pickup protons, the overall compression of the magnetic field in the outer heliosphere caused by deceleration, and the weakening of corotating interaction regions by the thermal pressure of pickup protons.

  19. Perceptual-center modeling is affected by including acoustic rate-of-change modulations.

    Science.gov (United States)

    Harsin, C A

    1997-02-01

    This study investigated the acoustic correlates of perceptual centers (p-centers) in CV and VC syllables and developed an acoustic p-center model. In Part 1, listeners located syllables' p-centers by a method-of-adjustment procedure. The CV syllables contained the consonants /s/,/r/,/n/,/t/,/d/,/k/, and /g/; the VCs, the consonants /s/,/r/, and /n/. The vowel in all syllables was /a/. The results of this experiment replicated and extended previous findings regarding the effects of phonetic variation on p-centers. In Part 2, a digital signal processing procedure was used to acoustically model p-center perception. Each stimulus was passed through a six-band digital filter, and the outputs were processed to derive low-frequency modulation components. These components were weighted according to a perceived modulation magnitude function and recombined to create six psychoacoustic envelopes containing modulation energies from 3 to 47 Hz. In this analysis, p-centers were found to be highly correlated with the time-weighted function of the rate-of-change in the psychoacoustic envelopes, multiplied by the psychoacoustic envelope magnitude increment. The results were interpreted as suggesting (1) the probable role of low-frequency energy modulations in p-center perception, and (2) the presence of perceptual processes that integrate multiple articulatory events into a single syllabic event.

  20. Establishment of a superficial skin infection model in mice by using Staphylococcus aureus and Streptococcus pyogenes.

    Science.gov (United States)

    Kugelberg, Elisabeth; Norström, Tobias; Petersen, Thomas K; Duvold, Tore; Andersson, Dan I; Hughes, Diarmaid

    2005-08-01

    A new animal model for the purpose of studying superficial infections is presented. In this model an infection is established by disruption of the skin barrier by partial removal of the epidermal layer by tape stripping and subsequent application of the pathogens Staphylococcus aureus and Streptococcus pyogenes. The infection and the infection route are purely topical, in contrast to those used in previously described animal models in mice, such as the skin suture-wound model, where the infection is introduced into the deeper layers of the skin. Thus, the present model is considered more biologically relevant for the study of superficial skin infections in mice and humans. Established topical antibiotic treatments are shown to be effective. The procedures involved in the model are simple, a feature that increases throughput and reproducibility. This new model should be applicable to the evaluation of novel antimicrobial treatments of superficial infections caused by S. aureus and S. pyogenes.

  1. An Animal Model of Trichloroethylene-Induced Skin Sensitization in BALB/c Mice.

    Science.gov (United States)

    Wang, Hui; Zhang, Jia-xiang; Li, Shu-long; Wang, Feng; Zha, Wan-sheng; Shen, Tong; Wu, Changhao; Zhu, Qi-xing

    2015-01-01

    Trichloroethylene (TCE) is a major occupational hazard and environmental contaminant that can cause multisystem disorders in the form of occupational medicamentosa-like dermatitis. Development of dermatitis involves several proinflammatory cytokines, but their role in TCE-mediated dermatitis has not been examined in a well-defined experimental model. In addition, few animal models of TCE sensitization are available, and the current guinea pig model has apparent limitations. This study aimed to establish a model of TCE-induced skin sensitization in BALB/c mice and to examine the role of several key inflammatory cytokines on TCE sensitization. The sensitization rate of dorsal painted group was 38.3%. Skin edema and erythema occurred in TCE-sensitized groups, as seen in 2,4-dinitrochlorobenzene (DNCB) positive control. Trichloroethylene sensitization-positive (dermatitis [+]) group exhibited increased thickness of epidermis, inflammatory cell infiltration, swelling, and necrosis in dermis and around hair follicle, but ear painted group did not show these histological changes. The concentrations of serum proinflammatory cytokines including tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-2 were significantly increased in 24, 48, and 72 hours dermatitis [+] groups treated with TCE and peaked at 72 hours. Deposition of TNF-α, IFN-γ, and IL-2 into the skin tissue was also revealed by immunohistochemistry. We have established a new animal model of skin sensitization induced by repeated TCE stimulations, and we provide the first evidence that key proinflammatory cytokines including TNF-α, IFN-γ, and IL-2 play an important role in the process of TCE sensitization.

  2. Bone invading NSCLC cells produce IL-7: mice model and human histologic data

    Directory of Open Access Journals (Sweden)

    Quarto Rodolfo

    2010-01-01

    Full Text Available Abstract Background Bone metastases are a common and dismal consequence of lung cancer that is a leading cause of death. The role of IL-7 in promoting bone metastases has been previously investigated in NSCLC, but many aspects remain to be disclosed. To further study IL-7 function in bone metastasis, we developed a human-in-mice model of bone aggression by NSCLC and analyzed human bone metastasis biopsies. Methods We used NOD/SCID mice implanted with human bone. After bone engraftment, two groups of mice were injected subcutaneously with A549, a human NSCLC cell line, either close or at the contralateral flank to the human bone implant, while a third control group did not receive cancer cells. Tumor and bone vitality and IL-7 expression were assessed in implanted bone, affected or not by A549. Serum IL-7 levels were evaluated by ELISA. IL-7 immunohistochemistry was performed on 10 human bone NSCLC metastasis biopsies for comparison. Results At 12 weeks after bone implant, we observed osteogenic activity and neovascularization, confirming bone vitality. Tumor aggressive cells implanted close to human bone invaded the bone tissue. The bone-aggressive cancer cells were positive for IL-7 staining both in the mice model and in human biopsies. Higher IL-7 serum levels were found in mice injected with A549 cells close to the bone implant compared to mice injected with A549 cells in the flank opposite to the bone implant. Conclusions We demonstrated that bone-invading cells express and produce IL-7, which is known to promote osteoclast activation and osteolytic lesions. Tumor-bone interaction increases IL-7 production, with an increase in IL-7 serum levels. The presented mice model of bone invasion by contiguous tumor is suitable to study bone-tumor cell interaction. IL-7 plays a role in the first steps of metastatic process.

  3. Experimental cell transplantation therapy in rat myocardial infarction model including nude rat preparation.

    Science.gov (United States)

    Dai, Wangde; Kloner, Robert A

    2010-01-01

    As a novel potential therapeutic strategy for cardiac disease, cell transplantation therapy has been extensively investigated in experimental studies and clinical trials. Although encouraging results have been demonstrated, a number of critical questions still remain to be answered. For example, what kind of stem cell and how many cells should be used; what is the best time for cell transplantation after acute myocardial infarction; which delivery approach is better, intravenous injection or direct intramyocardial injection? Transplantation of cells derived from human tissues into experimental animals may elicit an immune rejection. Immunodeficient nude rats provide a useful myocardial infarction model for cell transplantation therapy studies. We introduce our detailed methods of direct intramyocardial injection of immature heart cells and stem cells into the myocardial infarction region of rats and nude rats. Careful maintenance under aseptic conditions and proper surgical technique are essential to improve the survival of immunodeficient rats after surgery.

  4. Including ethical considerations in models for first-trimester screening for pre-eclampsia

    DEFF Research Database (Denmark)

    Jørgensen, Jennifer Maureen; Hedley, Paula L.; Gjerris, Mickey;

    2014-01-01

    Recent efforts to develop reliable and efficient early pregnancy screening programmes for pre-eclampsia have focused on com-bining clinical, biochemical and biophysical markers. The same model has been used for first-trimester screening for fetal aneuploidies i.e. prenatal diagnosis (PD), which...... is routinely offered to all pregnant women in many developed countries. Some studies suggest combining PD and pre-eclampsia screening, so women can be offered testing for a number of conditions at the same clinical visit. A combination of these tests may be practical in terms of saving time and resources......; however, the combination raises ethical issues. First-trimester PD and pre-eclampsia screening entail qualitative differences which alter the requirements for disclosure, non-directedness and consent with regard to the informed consent process. This article explores the differences related to the ethical...

  5. Memory of the Vernalized State in Plants including the Model Grass Brachypodium distachyon

    Directory of Open Access Journals (Sweden)

    Daniel P Woods

    2014-03-01

    Full Text Available Plant species that have a vernalization requirement exhibit variation in the ability to remember winter—i.e., variation in the stability of the vernalized state. Studies in Arabidopsis have demonstrated that molecular memory involves changes in the chromatin state and expression of the flowering repressor FLOWERING LOCUS C, and have revealed that single-gene differences can have large effects on the stability of the vernalized state. In the perennial Arabidopsis relative Arabis alpina, the lack of memory of winter is critical for its perennial life history. Our studies of flowering behavior in the model grass Brachypodium distachyon reveal extensive variation in the vernalization requirement, and studies of a particular Brachypodium accession that has a qualitative requirement for both cold exposure and inductive daylength reveals that Brachypodium can exhibit a highly stable vernalized state.

  6. The economic production lot size model extended to include more than one production rate

    DEFF Research Database (Denmark)

    Larsen, Christian

    2001-01-01

    btween the demand rate and the production rate which minimizes unit production costs, and should be used in an increasing order. Then, given the production rates, we derive closed-form expressions for all optimal runtimes as well as the minimum average cost. This analysis reveals that it is the size......We study an extension of the economic production lot size model, where more than one production rate can be used during a cycle. Moreover, the production rates, as well as their corresponding runtimes are decision variables. First, we show that all production rates should be choosen in the interval...... of the setup cost that determines the need for being able to use several production rates. Finally, we show how to derive a near-optimal solution of the general problem....

  7. The economic production lot size model extended to include more than one production rate

    DEFF Research Database (Denmark)

    Larsen, Christian

    2005-01-01

    production rates should be chosen in the interval between the demand rate and the production rate which minimizes unit production costs, and should be used in an increasing order. Then, given the production rates, we derive closed-form expressions for all optimal runtimes as well as the minimum average cost......We study an extension of the economic production lot size model, where more than one production rate can be used during a cycle. Moreover, the production rates, as well as their corresponding runtimes are decision variables. We decompose the problem into two subproblems. First, we show that all....... This analysis reveals that it is the size of the setup cost that determines the need for being able to use several production rates. We also show how to derive a near-optimal solution of the general problem....

  8. Modelling of safety barriers including human and organisational factors to improve process safety

    DEFF Research Database (Denmark)

    Markert, Frank; Duijm, Nijs Jan; Thommesen, Jacob

    2013-01-01

    explosion, and the Mont Blanc Tunnel Fire, such an approach may have helped to maintain the integrity of the designed provisions against major deviations resulting in these disasters. In order to make this paradigm operational, safety management and in particular risk assessment tools need to be refined....... A valuable approach is the inclusion of human and organisational factors into the simulation of the reliability of the technical system using event trees and fault trees and the concept of safety barriers. This has been demonstrated e.g. in the former European research project ARAMIS (Accidental Risk...... Assessment Methodology for IndustrieS, see Salvi et al 2006). ARAMIS employs the bow-tie approach to modelling hazardous scenarios, and it suggests the outcome of auditing safety management to be connected to a semi-quantitative assessment of the quality of safety barriers. ARAMIS discriminates a number...

  9. Non-insect crustacean models in developmental genetics including an encomium to Parhyale hawaiensis.

    Science.gov (United States)

    Stamataki, Evangelia; Pavlopoulos, Anastasios

    2016-08-01

    The impressive diversity of body plans, lifestyles and segmental specializations exhibited by crustaceans (barnacles, copepods, shrimps, crabs, lobsters and their kin) provides great material to address longstanding questions in evolutionary developmental biology. Recent advances in forward and reverse genetics and in imaging approaches applied in the amphipod Parhyale hawaiensis and other emerging crustacean model species have made it possible to probe the molecular and cellular basis of crustacean diversity. A number of biological and technical qualities like the slow tempo and holoblastic cleavage mode, the stereotypy of many cellular processes, the functional and morphological diversity of limbs along the body axis, and the availability of various experimental manipulations, have made Parhyale a powerful system to study normal development and regeneration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Robust and Adaptive OMR System Including Fuzzy Modeling, Fusion of Musical Rules, and Possible Error Detection

    Directory of Open Access Journals (Sweden)

    Isabelle Bloch

    2007-01-01

    Full Text Available This paper describes a system for optical music recognition (OMR in case of monophonic typeset scores. After clarifying the difficulties specific to this domain, we propose appropriate solutions at both image analysis level and high-level interpretation. Thus, a recognition and segmentation method is designed, that allows dealing with common printing defects and numerous symbol interconnections. Then, musical rules are modeled and integrated, in order to make a consistent decision. This high-level interpretation step relies on the fuzzy sets and possibility framework, since it allows dealing with symbol variability, flexibility, and imprecision of music rules, and merging all these heterogeneous pieces of information. Other innovative features are the indication of potential errors and the possibility of applying learning procedures, in order to gain in robustness. Experiments conducted on a large data base show that the proposed method constitutes an interesting contribution to OMR.

  11. Robust and Adaptive OMR System Including Fuzzy Modeling, Fusion of Musical Rules, and Possible Error Detection

    Science.gov (United States)

    Rossant, Florence; Bloch, Isabelle

    2006-12-01

    This paper describes a system for optical music recognition (OMR) in case of monophonic typeset scores. After clarifying the difficulties specific to this domain, we propose appropriate solutions at both image analysis level and high-level interpretation. Thus, a recognition and segmentation method is designed, that allows dealing with common printing defects and numerous symbol interconnections. Then, musical rules are modeled and integrated, in order to make a consistent decision. This high-level interpretation step relies on the fuzzy sets and possibility framework, since it allows dealing with symbol variability, flexibility, and imprecision of music rules, and merging all these heterogeneous pieces of information. Other innovative features are the indication of potential errors and the possibility of applying learning procedures, in order to gain in robustness. Experiments conducted on a large data base show that the proposed method constitutes an interesting contribution to OMR.

  12. Parsing recursive sentences with a connectionist model including a neural stack and synaptic gating.

    Science.gov (United States)

    Fedor, Anna; Ittzés, Péter; Szathmáry, Eörs

    2011-02-21

    It is supposed that humans are genetically predisposed to be able to recognize sequences of context-free grammars with centre-embedded recursion while other primates are restricted to the recognition of finite state grammars with tail-recursion. Our aim was to construct a minimalist neural network that is able to parse artificial sentences of both grammars in an efficient way without using the biologically unrealistic backpropagation algorithm. The core of this network is a neural stack-like memory where the push and pop operations are regulated by synaptic gating on the connections between the layers of the stack. The network correctly categorizes novel sentences of both grammars after training. We suggest that the introduction of the neural stack memory will turn out to be substantial for any biological 'hierarchical processor' and the minimalist design of the model suggests a quest for similar, realistic neural architectures.

  13. Areal rainfall estimation using moving cars - computer experiments including hydrological modeling

    Science.gov (United States)

    Rabiei, Ehsan; Haberlandt, Uwe; Sester, Monika; Fitzner, Daniel; Wallner, Markus

    2016-09-01

    The need for high temporal and spatial resolution precipitation data for hydrological analyses has been discussed in several studies. Although rain gauges provide valuable information, a very dense rain gauge network is costly. As a result, several new ideas have emerged to help estimating areal rainfall with higher temporal and spatial resolution. Rabiei et al. (2013) observed that moving cars, called RainCars (RCs), can potentially be a new source of data for measuring rain rate. The optical sensors used in that study are designed for operating the windscreen wipers and showed promising results for rainfall measurement purposes. Their measurement accuracy has been quantified in laboratory experiments. Considering explicitly those errors, the main objective of this study is to investigate the benefit of using RCs for estimating areal rainfall. For that, computer experiments are carried out, where radar rainfall is considered as the reference and the other sources of data, i.e., RCs and rain gauges, are extracted from radar data. Comparing the quality of areal rainfall estimation by RCs with rain gauges and reference data helps to investigate the benefit of the RCs. The value of this additional source of data is not only assessed for areal rainfall estimation performance but also for use in hydrological modeling. Considering measurement errors derived from laboratory experiments, the result shows that the RCs provide useful additional information for areal rainfall estimation as well as for hydrological modeling. Moreover, by testing larger uncertainties for RCs, they observed to be useful up to a certain level for areal rainfall estimation and discharge simulation.

  14. ECO: a generic eutrophication model including comprehensive sediment-water interaction.

    Directory of Open Access Journals (Sweden)

    Johannes G C Smits

    Full Text Available The content and calibration of the comprehensive generic 3D eutrophication model ECO for water and sediment quality is presented. Based on a computational grid for water and sediment, ECO is used as a tool for water quality management to simulate concentrations and mass fluxes of nutrients (N, P, Si, phytoplankton species, detrital organic matter, electron acceptors and related substances. ECO combines integral simulation of water and sediment quality with sediment diagenesis and closed mass balances. Its advanced process formulations for substances in the water column and the bed sediment were developed to allow for a much more dynamic calculation of the sediment-water exchange fluxes of nutrients as resulting from steep concentration gradients across the sediment-water interface than is possible with other eutrophication models. ECO is to more accurately calculate the accumulation of organic matter and nutrients in the sediment, and to allow for more accurate prediction of phytoplankton biomass and water quality in response to mitigative measures such as nutrient load reduction. ECO was calibrated for shallow Lake Veluwe (The Netherlands. Due to restoration measures this lake underwent a transition from hypertrophic conditions to moderately eutrophic conditions, leading to the extensive colonization by submerged macrophytes. ECO reproduces observed water quality well for the transition period of ten years. The values of its process coefficients are in line with ranges derived from literature. ECO's calculation results underline the importance of redox processes and phosphate speciation for the nutrient return fluxes. Among other things, the results suggest that authigenic formation of a stable apatite-like mineral in the sediment can contribute significantly to oligotrophication of a lake after a phosphorus load reduction.

  15. Parameterization of cloud droplet formation for global and regional models: including adsorption activation from insoluble CCN

    Directory of Open Access Journals (Sweden)

    P. Kumar

    2009-04-01

    Full Text Available Dust and black carbon aerosol have long been known to exert potentially important and diverse impacts on cloud droplet formation. Most studies to date focus on the soluble fraction of these particles, and overlook interactions of the insoluble fraction with water vapor (even if known to be hydrophilic. To address this gap, we developed a new parameterization that considers cloud droplet formation within an ascending air parcel containing insoluble (but wettable particles externally mixed with aerosol containing an appreciable soluble fraction. Activation of particles with a soluble fraction is described through well-established Köhler theory, while the activation of hydrophilic insoluble particles is treated by "adsorption-activation" theory. In the latter, water vapor is adsorbed onto insoluble particles, the activity of which is described by a multilayer Frenkel-Halsey-Hill (FHH adsorption isotherm modified to account for particle curvature. We further develop FHH activation theory to i find combinations of the adsorption parameters AFHH, BFHH which yield atmospherically-relevant behavior, and, ii express activation properties (critical supersaturation that follow a simple power law with respect to dry particle diameter.

    The new parameterization is tested by comparing the parameterized cloud droplet number concentration against predictions with a detailed numerical cloud model, considering a wide range of particle populations, cloud updraft conditions, water vapor condensation coefficient and FHH adsorption isotherm characteristics. The agreement between parameterization and parcel model is excellent, with an average error of 10% and R2~0.98. A preliminary sensitivity study suggests that the sublinear response of droplet number to Köhler particle concentration is not as strong for FHH particles.

  16. Parameterization of cloud droplet formation for global and regional models: including adsorption activation from insoluble CCN

    Science.gov (United States)

    Kumar, P.; Sokolik, I. N.; Nenes, A.

    2009-04-01

    Dust and black carbon aerosol have long been known to exert potentially important and diverse impacts on cloud droplet formation. Most studies to date focus on the soluble fraction of these particles, and overlook interactions of the insoluble fraction with water vapor (even if known to be hydrophilic). To address this gap, we developed a new parameterization that considers cloud droplet formation within an ascending air parcel containing insoluble (but wettable) particles externally mixed with aerosol containing an appreciable soluble fraction. Activation of particles with a soluble fraction is described through well-established Köhler theory, while the activation of hydrophilic insoluble particles is treated by "adsorption-activation" theory. In the latter, water vapor is adsorbed onto insoluble particles, the activity of which is described by a multilayer Frenkel-Halsey-Hill (FHH) adsorption isotherm modified to account for particle curvature. We further develop FHH activation theory to i) find combinations of the adsorption parameters AFHH, BFHH which yield atmospherically-relevant behavior, and, ii) express activation properties (critical supersaturation) that follow a simple power law with respect to dry particle diameter. The new parameterization is tested by comparing the parameterized cloud droplet number concentration against predictions with a detailed numerical cloud model, considering a wide range of particle populations, cloud updraft conditions, water vapor condensation coefficient and FHH adsorption isotherm characteristics. The agreement between parameterization and parcel model is excellent, with an average error of 10% and R2~0.98. A preliminary sensitivity study suggests that the sublinear response of droplet number to Köhler particle concentration is not as strong for FHH particles.

  17. ECO: a generic eutrophication model including comprehensive sediment-water interaction.

    Science.gov (United States)

    Smits, Johannes G C; van Beek, Jan K L

    2013-01-01

    The content and calibration of the comprehensive generic 3D eutrophication model ECO for water and sediment quality is presented. Based on a computational grid for water and sediment, ECO is used as a tool for water quality management to simulate concentrations and mass fluxes of nutrients (N, P, Si), phytoplankton species, detrital organic matter, electron acceptors and related substances. ECO combines integral simulation of water and sediment quality with sediment diagenesis and closed mass balances. Its advanced process formulations for substances in the water column and the bed sediment were developed to allow for a much more dynamic calculation of the sediment-water exchange fluxes of nutrients as resulting from steep concentration gradients across the sediment-water interface than is possible with other eutrophication models. ECO is to more accurately calculate the accumulation of organic matter and nutrients in the sediment, and to allow for more accurate prediction of phytoplankton biomass and water quality in response to mitigative measures such as nutrient load reduction. ECO was calibrated for shallow Lake Veluwe (The Netherlands). Due to restoration measures this lake underwent a transition from hypertrophic conditions to moderately eutrophic conditions, leading to the extensive colonization by submerged macrophytes. ECO reproduces observed water quality well for the transition period of ten years. The values of its process coefficients are in line with ranges derived from literature. ECO's calculation results underline the importance of redox processes and phosphate speciation for the nutrient return fluxes. Among other things, the results suggest that authigenic formation of a stable apatite-like mineral in the sediment can contribute significantly to oligotrophication of a lake after a phosphorus load reduction.

  18. Field theory of bicritical and tetracritical points. III. Relaxational dynamics including conservation of magnetization (model C).

    Science.gov (United States)

    Folk, R; Holovatch, Yu; Moser, G

    2009-03-01

    We calculate the relaxational dynamical critical behavior of systems of O(n_{ parallel}) plus sign in circleO(n_{ perpendicular}) symmetry including conservation of magnetization by renormalization group theory within the minimal subtraction scheme in two-loop order. Within the stability region of the Heisenberg fixed point and the biconical fixed point, strong dynamical scaling holds, with the asymptotic dynamical critical exponent z=2varphinu-1 , where varphi is the crossover exponent and nu the exponent of the correlation length. The critical dynamics at n_{ parallel}=1 and n_{ perpendicular}=2 is governed by a small dynamical transient exponent leading to nonuniversal nonasymptotic dynamical behavior. This may be seen, e.g., in the temperature dependence of the magnetic transport coefficients.

  19. Cholesterol Synthesis Increased in the MMI-Induced Subclinical Hypothyroidism Mice Model

    Science.gov (United States)

    Zhang, Xiujuan; Chen, Wenbin

    2017-01-01

    Subclinical hypothyroidism (SCH) is defined as increased serum thyroid-stimulating hormone (TSH) concentrations and normal serum thyroid hormone (TH) levels as well as an increased serum cholesterol level, which is an important cause of secondary hypercholesterolemia and cardiovascular diseases. Some studies have demonstrated a direct effect of TSH on cholesterol metabolism via in vivo and in vitro experiments. However, because no suitable SCH model has been established until now, the changes in cholesterol synthesis that occur in SCH patients remain unknown. Here, we establish an SCH mouse model by using long-term low-dose MMI administered in drinking water. Compared with the control group, the MMI-treated mice had elevated circulating TSH levels, but the serum FT3 levels in these mice did not change. Additionally, the TC levels increased in both the serum and liver of the experimental mice. Both the protein expression and activity of hepatic HMGCR, the rate-limiting enzyme for cholesterol synthesis in the liver, increased in these mice. We also found that the SCH mice had decreased phospho-HMGCR and phospho-AMPK expression, while the expression of AMPK showed no change. In conclusion, we established a suitable SCH model in which cholesterol synthesis is increased. PMID:28386276

  20. Arrhythmia and cardiac defects are a feature of spinal muscular atrophy model mice.

    Science.gov (United States)

    Heier, Christopher R; Satta, Rosalba; Lutz, Cathleen; DiDonato, Christine J

    2010-10-15

    Proximal spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality. Traditionally, SMA has been described as a motor neuron disease; however, there is a growing body of evidence that arrhythmia and/or cardiomyopathy may present in SMA patients at an increased frequency. Here, we ask whether SMA model mice possess such phenotypes. We find SMA mice suffer from severe bradyarrhythmia characterized by progressive heart block and impaired ventricular depolarization. Echocardiography further confirms functional cardiac deficits in SMA mice. Additional investigations show evidence of both sympathetic innervation defects and dilated cardiomyopathy at late stages of disease. Based upon these data, we propose a model in which decreased sympathetic innervation causes autonomic imbalance. Such imbalance would be characterized by a relative increase in the level of vagal tone controlling heart rate, which is consistent with bradyarrhythmia and progressive heart block. Finally, treatment with the histone deacetylase inhibitor trichostatin A, a drug known to benefit phenotypes of SMA model mice, produces prolonged maturation of the SMA heartbeat and an increase in cardiac size. Treated mice maintain measures of motor function throughout extended survival though they ultimately reach death endpoints in association with a progression of bradyarrhythmia. These data represent the novel identification of cardiac arrhythmia as an early and progressive feature of murine SMA while providing several new, quantitative indices of mouse health. Together with clinical cases that report similar symptoms, this reveals a new area of investigation that will be important to address as we move SMA therapeutics towards clinical success.

  1. Deletion of the App-Runx1 region in mice models human partial monosomy 21

    Directory of Open Access Journals (Sweden)

    Thomas Arbogast

    2015-06-01

    Full Text Available Partial monosomy 21 (PM21 is a rare chromosomal abnormality that is characterized by the loss of a variable segment along human chromosome 21 (Hsa21. The clinical phenotypes of this loss are heterogeneous and range from mild alterations to lethal consequences, depending on the affected region of Hsa21. The most common features include intellectual disabilities, craniofacial dysmorphology, short stature, and muscular and cardiac defects. As a complement to human genetic approaches, our team has developed new monosomic mouse models that carry deletions on Hsa21 syntenic regions in order to identify the dosage-sensitive genes that are responsible for the symptoms. We focus here on the Ms5Yah mouse model, in which a 7.7-Mb region has been deleted from the App to Runx1 genes. Ms5Yah mice display high postnatal lethality, with a few surviving individuals showing growth retardation, motor coordination deficits, and spatial learning and memory impairments. Further studies confirmed a gene dosage effect in the Ms5Yah hippocampus, and pinpointed disruptions of pathways related to cell adhesion (involving App, Cntnap5b, Lgals3bp, Mag, Mcam, Npnt, Pcdhb2, Pcdhb3, Pcdhb4, Pcdhb6, Pcdhb7, Pcdhb8, Pcdhb16 and Vwf. Our PM21 mouse model is the first to display morphological abnormalities and behavioural phenotypes similar to those found in affected humans, and it therefore demonstrates the major contribution that the App-Runx1 region has in the pathophysiology of PM21.

  2. Continuous observation on heart-disease-model mice using biomagnetic measurement system

    Science.gov (United States)

    Kasai, Y.; Oikawa, T.; Saitoh, Y.; Ono, Y.; Ishiyama, A.; Kasai, N.; Odawara, A.; Chinone, K.

    2008-02-01

    Magnetocardiography (MCG) is a non-invasive method that can contribute to elucidating heart disease mechanisms and the verification of pharmacological effects. The object of our study is to show the potential of MCG for such study in mice. By using the developed MCG system, which adopts a single channel superconducting quantum interference device (SQUID) magnetometer with the spatial resolution of 500 μm, we continuously measured MCGs for 2 heart-disease-model mice with a high incidence of cardiac infarction from 7-weeks-old to death. An abnormal MCG appeared 1 or 2 weeks before death. The abnormal MCG changes indicate that the damaged place in the ventricles was different for each individual. In addition, we have developed a method to obtain MCGs for newborn mice in particular because they are small and frail. The MCGs of newborn mice were similar to those of adult mice. This study proved the potential of MCG for detecting abnormal cardiac excitation at the early stage of cardiac infarction and monitoring the progress of heart disease in detail from infancy to old age in mice.

  3. Hypogammaglobulinemia in BLT humanized mice--an animal model of primary antibody deficiency.

    Directory of Open Access Journals (Sweden)

    Francisco Martinez-Torres

    Full Text Available Primary antibody deficiencies present clinically as reduced or absent plasma antibodies without another identified disorder that could explain the low immunoglobulin levels. Bone marrow-liver-thymus (BLT humanized mice also exhibit primary antibody deficiency or hypogammaglobulinemia. Comprehensive characterization of B cell development and differentiation in BLT mice revealed other key parallels with primary immunodeficiency patients. We found that B cell ontogeny was normal in the bone marrow of BLT mice but observed an absence of switched memory B cells in the periphery. PC-KLH immunizations led to the presence of switched memory B cells in immunized BLT mice although plasma cells producing PC- or KLH- specific IgG were not detected in tissues. Overall, we have identified the following parallels between the humoral immune systems of primary antibody deficiency patients and those in BLT mice that make this in vivo model a robust and translational experimental platform for gaining a greater understanding of this heterogeneous array of humoral immunodeficiency disorders in humans: (i hypogammaglobulinemia; (ii normal B cell ontogeny in bone marrow; and (iii poor antigen-specific IgG response to immunization. Furthermore, the development of strategies to overcome these humoral immune aberrations in BLT mice may in turn provide insights into the pathogenesis of some primary antibody deficiency patients which could lead to novel clinical interventions for improved humoral immune function.

  4. Knock out of S1P3 receptor signaling attenuates inflammation and fibrosis in bleomycin-induced lung injury mice model.

    Directory of Open Access Journals (Sweden)

    Ken Murakami

    Full Text Available Sphingosine-1-phosphate (S1P is a bioactive sphingolipid metabolite involved in many critical cellular processes, including proliferation, migration, and angiogenesis, through interaction with a family of five G protein-coupled receptors (S1P1-5. Some reports have implicated S1P as an important inflammatory mediator of the pathogenesis of airway inflammation, but the role of S1P3 in the pathogenesis of lung diseases is not completely understood. We used S1P3-deficient (knockout (KO mice to clarify the role of S1P3 receptor signaling in the pathogenesis of pulmonary inflammation and fibrosis using a bleomycin-induced model of lung injury. On the seventh day after bleomycin administration, S1P3 KO mice exhibited significantly less body weight loss and pulmonary inflammation than wild-type (WT mice. On the 28th day, there was less pulmonary fibrosis in S1P3 KO mice than in WT mice. S1P3 KO mice demonstrated a 56% reduction in total cell count in bronchoalveolar lavage fluid (BALF collected on the seventh day compared with WT mice; however, the differential white blood cell profiles were similar. BALF analysis on the seventh day showed that connective tissue growth factor (CTGF levels were significantly decreased in S1P3 KO mice compared with WT mice, although no differences were observed in monocyte chemotactic protein-1 (MCP-1 or transforming growth factor β1 (TGF-β1 levels. Finally, S1P levels in BALF collected on the 7th day after treatment were not significantly different between WT and S1P3 KO mice. Our results indicate that S1P3 receptor signaling plays an important role in pulmonary inflammation and fibrosis and that this signaling occurs via CTGF expression. This suggests that this pathway might be a therapeutic target for pulmonary fibrosis.

  5. Knock out of S1P3 receptor signaling attenuates inflammation and fibrosis in bleomycin-induced lung injury mice model.

    Science.gov (United States)

    Murakami, Ken; Kohno, Masataka; Kadoya, Masatoshi; Nagahara, Hidetake; Fujii, Wataru; Seno, Takahiro; Yamamoto, Aihiro; Oda, Ryo; Fujiwara, Hiroyoshi; Kubo, Toshikazu; Morita, Satoshi; Nakada, Hiroshi; Hla, Timothy; Kawahito, Yutaka

    2014-01-01

    Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid metabolite involved in many critical cellular processes, including proliferation, migration, and angiogenesis, through interaction with a family of five G protein-coupled receptors (S1P1-5). Some reports have implicated S1P as an important inflammatory mediator of the pathogenesis of airway inflammation, but the role of S1P3 in the pathogenesis of lung diseases is not completely understood. We used S1P3-deficient (knockout (KO)) mice to clarify the role of S1P3 receptor signaling in the pathogenesis of pulmonary inflammation and fibrosis using a bleomycin-induced model of lung injury. On the seventh day after bleomycin administration, S1P3 KO mice exhibited significantly less body weight loss and pulmonary inflammation than wild-type (WT) mice. On the 28th day, there was less pulmonary fibrosis in S1P3 KO mice than in WT mice. S1P3 KO mice demonstrated a 56% reduction in total cell count in bronchoalveolar lavage fluid (BALF) collected on the seventh day compared with WT mice; however, the differential white blood cell profiles were similar. BALF analysis on the seventh day showed that connective tissue growth factor (CTGF) levels were significantly decreased in S1P3 KO mice compared with WT mice, although no differences were observed in monocyte chemotactic protein-1 (MCP-1) or transforming growth factor β1 (TGF-β1) levels. Finally, S1P levels in BALF collected on the 7th day after treatment were not significantly different between WT and S1P3 KO mice. Our results indicate that S1P3 receptor signaling plays an important role in pulmonary inflammation and fibrosis and that this signaling occurs via CTGF expression. This suggests that this pathway might be a therapeutic target for pulmonary fibrosis.

  6. Regional modelling of future African climate north of 15S including greenhouse warming and land degradation

    Energy Technology Data Exchange (ETDEWEB)

    Paeth, H. [Geographical Institute, University of Wuerzburg, Am Hubland, 97074 Wuerzburg (Germany); Thamm, H.P. [Geographical Institute, University of Bonn, Bonn (Germany)

    2007-08-15

    Previous studies have highlighted the crucial role of land degradation in tropical African climate. This effect urgently has to be taken into account when predicting future African climate under enhanced greenhouse conditions. Here, we present time slice experiments of African climate until 2025, using a high-resolution regional climate model. A supposable scenario of future land use changes, involving vegetation loss and soil degradation, is prescribed simultaneously with increasing greenhouse-gas concentrations in order to detect, where the different forcings counterbalance or reinforce each other. This proceeding allows us to define the regions of highest vulnerability with respect to future freshwater availability and food security in tropical and subtropical Africa and may provide a decision basis for political measures. The model simulates a considerable reduction in precipitation amount until 2025 over most of tropical Africa, amounting to partly more than 500 mm (20-40% of the annual sum), particularly in the Congo Basin and the Sahel Zone. The change is strongest in boreal summer and basically reflects the pattern of maximum vegetation cover during the seasonal cycle. The related change in the surface energy fluxes induces a substantial near-surface warming by up to 7C. According to the modified temperature gradients over tropical Africa, the summer monsoon circulation intensifies and transports more humid air masses into the southern part of West Africa. This humidifying effect is overcompensated by a remarkable decrease in surface evaporation, leading to the overall drying tendency over most of Africa. Extreme daily rainfall events become stronger in autumn but less intense in spring. Summer and autumn appear to be characterized by more severe heat waves over Subsaharan West Africa. In addition, the Tropical Easterly Jet is weakening, leading to enhanced drought conditions in the Sahel Zone. All these results suggest that the local impact of land

  7. Nuclear Reactor/Hydrogen Process Interface Including the HyPEP Model

    Energy Technology Data Exchange (ETDEWEB)

    Steven R. Sherman

    2007-05-01

    The Nuclear Reactor/Hydrogen Plant interface is the intermediate heat transport loop that will connect a very high temperature gas-cooled nuclear reactor (VHTR) to a thermochemical, high-temperature electrolysis, or hybrid hydrogen production plant. A prototype plant called the Next Generation Nuclear Plant (NGNP) is planned for construction and operation at the Idaho National Laboratory in the 2018-2021 timeframe, and will involve a VHTR, a high-temperature interface, and a hydrogen production plant. The interface is responsible for transporting high-temperature thermal energy from the nuclear reactor to the hydrogen production plant while protecting the nuclear plant from operational disturbances at the hydrogen plant. Development of the interface is occurring under the DOE Nuclear Hydrogen Initiative (NHI) and involves the study, design, and development of high-temperature heat exchangers, heat transport systems, materials, safety, and integrated system models. Research and development work on the system interface began in 2004 and is expected to continue at least until the start of construction of an engineering-scale demonstration plant.

  8. Landau quantized dynamics and spectra for group-VI dichalcogenides, including a model quantum wire

    Directory of Open Access Journals (Sweden)

    Norman J. M. Horing

    2017-06-01

    Full Text Available This work is concerned with the derivation of the Green’s function for Landau-quantized carriers in the Group-VI dichalcogenides. In the spatially homogeneous case, the Green’s function is separated into a Peierls phase factor and a translationally invariant part which is determined in a closed form integral representation involving only elementary functions. The latter is expanded in an eigenfunction series of Laguerre polynomials. These results for the retarded Green’s function are presented in both position and momentum representations, and yet another closed form representation is derived in circular coordinates in terms of the Bessel wave function of the second kind (not to be confused with the Bessel function. The case of a quantum wire is also addressed, representing the quantum wire in terms of a model one-dimensional δ(x-potential profile. This retarded Green’s function for propagation directly along the wire is determined exactly in terms of the corresponding Green’s function for the system without the δ(x-potential, and the Landau quantized eigenenergy dispersion relation is examined. The thermodynamic Green’s function for the dichalcogenide carriers in a normal magnetic field is formulated here in terms of its spectral weight, and its solution is presented in a momentum/integral representation involving only elementary functions, which is subsequently expanded in Laguerre eigenfunctions and presented in both momentum and position representations.

  9. A fully model-based MPC solution including VSB shot dose assignment and shape correction

    Science.gov (United States)

    Bork, Ingo; Buck, Peter; Reddy, Murali; Durvasula, Bhardwaj

    2015-10-01

    The value of using multiple dose levels for individual shots on VSB (Variable Shaped Beam) mask writers has been demonstrated earlier [1][2]. The main advantage of modulating dose on a per shot basis is the fact that higher dose levels can be used selectively for critical features while other areas of the mask with non-critical feature types can be exposed at lower dose levels. This reduces the amount of backscattering and mask write time penalty compared to a global overdose-undersize approach. While dose assignment to certain polygons or parts of polygons (VSB shots) can easily be accomplished via DRC rules on layers with limited shape variations like contact or VIA layers, it can be challenging to come up with consistent rules for layers consisting of a very broad range of shapes, generally found on metal layers. This work introduces a method for fully model-based modulation of shot dose for VSB machines supporting between two and eight dose levels and demonstrates results achieved with this method.

  10. Subretinal Pigment Epithelial Deposition of Drusen Components Including Hydroxyapatite in a Primary Cell Culture Model

    Science.gov (United States)

    Pilgrim, Matthew G.; Lengyel, Imre; Lanzirotti, Antonio; Newville, Matt; Fearn, Sarah; Emri, Eszter; Knowles, Jonathan C.; Messinger, Jeffrey D.; Read, Russell W.; Guidry, Clyde; Curcio, Christine A.

    2017-01-01

    Purpose Extracellular deposits containing hydroxyapatite, lipids, proteins, and trace metals that form between the basal lamina of the RPE and the inner collagenous layer of Bruch's membrane are hallmarks of early AMD. We examined whether cultured RPE cells could produce extracellular deposits containing all of these molecular components. Methods Retinal pigment epithelium cells isolated from freshly enucleated porcine eyes were cultured on Transwell membranes for up to 6 months. Deposit composition and structure were characterized using light, fluorescence, and electron microscopy; synchrotron x-ray diffraction and x-ray fluorescence; secondary ion mass spectroscopy; and immunohistochemistry. Results Apparently functional primary RPE cells, when cultured on 10-μm-thick inserts with 0.4-μm-diameter pores, can produce sub-RPE deposits that contain hydroxyapatite, lipids, proteins, and trace elements, without outer segment supplementation, by 12 weeks. Conclusions The data suggest that sub-RPE deposit formation is initiated, and probably regulated, by the RPE, as well as the loss of permeability of the Bruch's membrane and choriocapillaris complex associated with age and early AMD. This cell culture model of early AMD lesions provides a novel system for testing new therapeutic interventions against sub-RPE deposit formation, an event occurring well in advance of the onset of vision loss. PMID:28146236

  11. Landau quantized dynamics and spectra for group-VI dichalcogenides, including a model quantum wire

    Science.gov (United States)

    Horing, Norman J. M.

    2017-06-01

    This work is concerned with the derivation of the Green's function for Landau-quantized carriers in the Group-VI dichalcogenides. In the spatially homogeneous case, the Green's function is separated into a Peierls phase factor and a translationally invariant part which is determined in a closed form integral representation involving only elementary functions. The latter is expanded in an eigenfunction series of Laguerre polynomials. These results for the retarded Green's function are presented in both position and momentum representations, and yet another closed form representation is derived in circular coordinates in terms of the Bessel wave function of the second kind (not to be confused with the Bessel function). The case of a quantum wire is also addressed, representing the quantum wire in terms of a model one-dimensional δ (x ) -potential profile. This retarded Green's function for propagation directly along the wire is determined exactly in terms of the corresponding Green's function for the system without the δ (x ) -potential, and the Landau quantized eigenenergy dispersion relation is examined. The thermodynamic Green's function for the dichalcogenide carriers in a normal magnetic field is formulated here in terms of its spectral weight, and its solution is presented in a momentum/integral representation involving only elementary functions, which is subsequently expanded in Laguerre eigenfunctions and presented in both momentum and position representations.

  12. A Novel Letrozole Model Recapitulates Both the Reproductive and Metabolic Phenotypes of Polycystic Ovary Syndrome in Female Mice.

    Science.gov (United States)

    Kauffman, Alexander S; Thackray, Varykina G; Ryan, Genevieve E; Tolson, Kristen P; Glidewell-Kenney, Christine A; Semaan, Sheila J; Poling, Matthew C; Iwata, Nahoko; Breen, Kellie M; Duleba, Antoni J; Stener-Victorin, Elisabet; Shimasaki, Shunichi; Webster, Nicholas J; Mellon, Pamela L

    2015-09-01

    Polycystic ovary syndrome (PCOS) pathophysiology is poorly understood, due partly to lack of PCOS animal models fully recapitulating this complex disorder. Recently, a PCOS rat model using letrozole (LET), a nonsteroidal aromatase inhibitor, mimicked multiple PCOS phenotypes, including metabolic features absent in other models. Given the advantages of using genetic and transgenic mouse models, we investigated whether LET produces a similar PCOS phenotype in mice. Pubertal female C57BL/6N mice were treated for 5 wk with LET, which resulted in increased serum testosterone and normal diestrus levels of estradiol, similar to the hyperandrogenemia and follicular phase estrogen levels of PCOS women. As in PCOS, ovaries from LET mice were larger, polycystic, and lacked corpora lutea versus controls. Most LET females were acyclic, and all were infertile. LET females displayed elevated serum LH levels and higher Lhb mRNA in the pituitary. In contrast, serum FSH and Fshb were significantly reduced in LET females, demonstrating differential effects on gonadotropins, as in PCOS. Within the ovary, LET females had higher Cyp17, Cyp19, and Fsh receptor mRNA expression. In the hypothalamus, LET females had higher kisspeptin receptor mRNA expression but lower progesterone receptor mRNA levels. LET females also gained more weight than controls, had increased abdominal adiposity and adipocyte size, elevated adipose inflammatory mRNA levels, and impaired glucose tolerance, mirroring the metabolic phenotype in PCOS women. This is the first report of a LET paradigm in mice that recapitulates both reproductive and metabolic PCOS phenotypes and will be useful to genetically probe the PCOS condition.

  13. Going beyond efficiency: including altruistic motives in behavioral models for sustainability transitions to address sufficiency

    Directory of Open Access Journals (Sweden)

    Niko Schäpke

    2014-07-01

    Full Text Available Sustainability transitions require altered individual behaviors. Policies aimed at changing people’s consumption behavior are designed according to efficiency, consistency, and sufficiency principles. Taking into account shortcomings of the first two principles, this paper specifically addresses the sufficiency principle. Sufficiency policies are not very popular due to the fear that they may impede quality of life. This fear might be eased when highlighting the motivational side of sustainable behavior, such as the wish to care for future generations and the world’s poor. This article uses the capability approach (CA, developed primarily by Nobel-laureate economist Amartya Sen (1987a and philosopher Martha Nussbaum (1993, 2000, to a include the differentiation between self- and other-oriented goals and behavior, b build on its demonstrated success in assessing quality of life, and c assess the sustainability of behavior and policies. These three facets make CA suitable to analyze the effectiveness of sufficiency policies on sustainability and quality of life. To better understand the motivational side of sustainable behavior, CA is here for the first time enriched through approaches from environmental psychology. This enables us to highlight the idea of intrinsic empowerment as a building block for sufficiency policies. We close the article by highlighting further avenues for research.

  14. Interrelationship of cranial suture fusion, basicranial development, and resynostosis following suturectomy in twist1(+/-) mice, a murine model of Saethre-Chotzen syndrome.

    Science.gov (United States)

    Hermann, Christopher D; Lee, Christopher S D; Gadepalli, Siddharth; Lawrence, Kelsey A; Richards, Megan A; Olivares-Navarrete, Rene; Williams, Joseph K; Schwartz, Zvi; Boyan, Barbara D

    2012-10-01

    The interrelationships among suture fusion, basicranial development, and subsequent resynostosis in syndromic craniosynostosis have yet to be examined. The objectives of this study were to determine the potential relationship between suture fusion and cranial base development in a model of syndromic craniosynostosis and to assess the effects of the syndrome on resynostosis following suturectomy. To do this, posterior frontal and coronal suture fusion, postnatal development of sphenooccipital synchondrosis, and resynostosis in Twist1(+/+) (WT) and Twist1(+/-) litter-matched mice (a model for Saethre-Chotzen syndrome) were quantified by evaluating μCT images with advanced image-processing algorithms. The coronal suture in Twist(+/-) mice developed, fused, and mineralized at a faster rate than that in normal littermates at postnatal days 6-30. Moreover, premature fusion of the coronal suture in Twist1(+/-) mice preceded alterations in cranial base development. Analysis of synchondrosis showed faster mineralization in Twist(+/-) mice at postnatal days 25-30. In a rapid resynostosis model, there was an inability to fuse both the midline posterior frontal suture and craniotomy defects in 21-day-old Twist(+/-) mice, despite having accelerated mineralization in the posterior frontal suture and defects. This study showed that dissimilarities between Twist1(+/+) and Twist1(+/-) mice are not limited to a fused coronal suture but include differences in fusion of other sutures, the regenerative capacity of the cranial vault, and the development of the cranial base.

  15. Generation and characterization of transgenic mice expressing mitochondrial targeted red fluorescent protein selectively in neurons: modeling mitochondriopathy in excitotoxicity and amyotrophic lateral sclerosis

    Directory of Open Access Journals (Sweden)

    Wang Yi

    2011-11-01

    Full Text Available Abstract Background Mitochondria have roles or appear to have roles in the pathogenesis of several chronic age-related and acute neurological disorders, including Charcot-Marie-Tooth disease, amyotrophic lateral sclerosis, Parkinson's disease, and cerebral ischemia, and could be critical targets for development of rational mechanism-based, disease-modifying therapeutics for treating these disorders effectively. A deeper understanding of neural tissue mitochondria pathobiologies as definitive mediators of neural injury, disease, and cell death merits further study, and the development of additional tools to study neural mitochondria will help achieve this unmet need. Results We created transgenic mice that express the coral (Discosoma sp. red fluorescent protein DsRed2 specifically in mitochondria of neurons using a construct engineered with a Thy1 promoter, specific for neuron expression, to drive expression of a fusion protein of DsRed2 with a mitochondrial targeting sequence. The biochemical and histological characterization of these mice shows the expression of mitochondrial-targeted DsRed2 to be specific for mitochondria and concentrated in distinct CNS regions, including cerebral cortex, hippocampus, thalamus, brainstem, and spinal cord. Red fluorescent mitochondria were visualized in cerebral cortical and hippocampal pyramidal neurons, ventrobasal thalamic neurons, subthalamic neurons, and spinal motor neurons. For the purpose of proof of principle application, these mice were used in excitotoxicity paradigms and double transgenic mice were generated by crossing Thy1-mitoDsRed2 mice with transgenic mice expressing enhanced-GFP (eGFP under the control of the Hlxb9 promoter that drives eGFP expression specifically in motor neurons and by crossing Thy1-mitoDsRed2 mice to amyotrophic lateral sclerosis (ALS mice expressing human mutant superoxide dismutase-1. Conclusions These novel transgenic mice will be a useful tool for better understanding

  16. Sex differences in response to activity-based anorexia model in C57Bl/6 mice.

    Science.gov (United States)

    Achamrah, Najate; Nobis, Séverine; Goichon, Alexis; Breton, Jonathan; Legrand, Romain; do Rego, Jean Luc; do Rego, Jean Claude; Déchelotte, Pierre; Fetissov, Sergueï O; Belmonte, Liliana; Coëffier, Moïse

    2017-03-01

    Anorexia nervosa is a severe eating disorder often associated with physical hyperactivity and is more frequently observed in female sex. Activity-Based Anorexia (ABA) model combines physical activity (PA) and reduced food intake and thus allows a better understanding of the mechanisms underlying anorexia nervosa. We aimed to assess sex differences in response to ABA model in C57Bl/6 mice. Twenty four male and 16 female C57BL/6 mice were studied. ABA mice were placed in individual cages with a continuously recorded activity wheel. ABA mice had a progressive limited food access from 6h/day (day 6) to 3h/day (day 9) until the end of the protocol (day 17). Body weight and food intake were daily measured. We studied physical activity during 24h, during the dark phase (D-PA) and the light phase (L-PA). We also evaluated the feeding anticipatory physical activity (A-PA), the physical activity during food intake period (FI-PA) and the post-prandial physical activity (PP-PA). We observed 16.7% of mortality in males (4 out of 24 mice) during ABA protocol while no female mice died (p=0.09). At day 17, food intake was significantly higher in females than in males (pgender differences in wheel running activity were observed. From day 9, A-PA significantly increased over time in males (pgender differences, in particularly for L-PA and A-PA. Our results suggest a greater susceptibility of male mice to develop ABA, males and females exhibit different patterns of physical activity after limitation of food access. Underlying mechanisms should be further investigated. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Generating double knockout mice to model genetic intervention for diabetic cardiomyopathy in humans.

    Science.gov (United States)

    Chavali, Vishalakshi; Nandi, Shyam Sundar; Singh, Shree Ram; Mishra, Paras Kumar

    2014-01-01

    Diabetes is a rapidly increasing disease that enhances the chances of heart failure twofold to fourfold (as compared to age and sex matched nondiabetics) and becomes a leading cause of morbidity and mortality. There are two broad classifications of diabetes: type1 diabetes (T1D) and type2 diabetes (T2D). Several mice models mimic both T1D and T2D in humans. However, the genetic intervention to ameliorate diabetic cardiomyopathy in these mice often requires creating double knockout (DKO). In order to assess the therapeutic potential of a gene, that specific gene is either overexpressed (transgenic expression) or abrogated (knockout) in the diabetic mice. If the genetic mice model for diabetes is used, it is necessary to create DKO with transgenic/knockout of the target gene to investigate the specific role of that gene in pathological cardiac remodeling in diabetics. One of the important genes involved in extracellular matrix (ECM) remodeling in diabetes is matrix metalloproteinase-9 (Mmp9). Mmp9 is a collagenase that remains latent in healthy hearts but induced in diabetic hearts. Activated Mmp9 degrades extracellular matrix (ECM) and increases matrix turnover causing cardiac fibrosis that leads to heart failure. Insulin2 mutant (Ins2+/-) Akita is a genetic model for T1D that becomes diabetic spontaneously at the age of 3-4 weeks and show robust hyperglycemia at the age of 10-12 weeks. It is a chronic model of T1D. In Ins2+/- Akita, Mmp9 is induced. To investigate the specific role of Mmp9 in diabetic hearts, it is necessary to create diabetic mice where Mmp9 gene is deleted. Here, we describe the method to generate Ins2+/-/Mmp9-/- (DKO) mice to determine whether the abrogation of Mmp9 ameliorates diabetic cardiomyopathy.

  18. Direct radiative effect modeled for regional aerosols in central Europe including the effect of relative humidity

    Science.gov (United States)

    Iorga, G.; Hitzenberger, R.; Kasper-Giebl, A.; Puxbaum, Hans

    2007-01-01

    In view of both the climatic relevance of aerosols and the fact that aerosol burdens in central Europe are heavily impacted by anthropogenic sources, this study is focused on estimating the regional-scale direct radiative effect of aerosols in Austria. The aerosol data (over 80 samples in total) were collected during measurement campaigns at five sampling sites: the urban areas of Vienna, Linz, and Graz and on Mt. Rax (1644 m, regional background aerosol) and Mt. Sonnblick (3106 m, background aerosol). Aerosol mass size distributions were obtained with eight-stage (size range: 0.06-16 μm diameter) and six-stage (size range 0.1-10 μm) low-pressure cascade impactors. The size-segregated samples were analyzed for total carbon (TC), black carbon (BC), and inorganic ions. The aerosol at these five locations is compared in terms of size distributions, optical properties, and direct forcing. Mie calculations are performed for the dry aerosol at 60 wavelengths in the range 0.3-40 μm. Using mass growth factors determined earlier, the optical properties are also estimated for higher relative humidities (60%, 70%, 80%, and 90%). A box model was used to estimate direct radiative forcing (DRF). The presence of absorbing species (BC) was found to reduce the cooling effect of the aerosols. The water-soluble substances dominate radiative forcing at the urban sites, while on Rax and Sonnblick BC plays the most important role. This result can be explained by the effect of the surface albedo, which is much lower in the urban regions (0.16) than at the ice and snow-covered mountain sites. Shortwave (below 4 μm) and longwave surface albedo values for ice were 0.35 and 0.5, while for snow surface albedo, values of 0.8 (shortwave) and 0.5 (longwave) were used. In the case of dry aerosol, especially for urban sites, the unidentified material may contribute a large part to the forcing. Depending on the sampling site the estimated forcing gets more negative with increasing humidity

  19. Establishment of a mdrl Multidrug Resistant Model of Orthotopic Transplantation of Liver Carcinoma on Nude Mice

    Institute of Scientific and Technical Information of China (English)

    HANYu; CHENXiaoping

    2005-01-01

    Objective: To develop a new method of inducing mdrl multidrug resistance by establishing a nude mice model of orthotopic transplantation of liver carcinoma by sporadic abdominal chemotherapy at intervals. Methods: Hepatocellular carcinoma HepG2 cell was cultured and injected subcutaneously to form the tumor-supplying mice. The tumor bits from the tumor-supplying mice were implanted under the envelope of the mice liver and induced by abdominal chemotherapy with Pharmorubicin. Physical examination, ultrasonography, spiral CT and operative inspection were used to examine tumor progression. RT-PCR and immunohistochemistry were adopted to detect the expression of mdrl-mRNA and its encoded protein P-gp protein (P-gp). Results: There was no operative dead, the rate of implanting tumor successfully was 88% (22/25), the rate of implanting secondly successfully was 100% (3/3), and the rate of inducing successfully was 80% (16/20). The expression of mdrl-mRNA and the P-gp in the inducing group was 23 folds and 13 folds in the control group respectively. Conclusion: We have established an in vivo model of mdr using nude mice transplanted with orthotopic liver neoplasm coupled to chemotherapy.

  20. Mint3 in bone marrow-derived cells promotes lung metastasis in breast cancer model mice.

    Science.gov (United States)

    Hara, Toshiro; Murakami, Yoshinori; Seiki, Motoharu; Sakamoto, Takeharu

    2017-08-26

    Breast cancer is one of the most common cancers in women in the world. Although breast cancer is well treatable at the early stage, patients with distant metastases show a poor prognosis. Data from recent studies using transplantation models indicate that Mint3/APBA3 might promote breast cancer malignancy. However, whether Mint3 indeed contributes to tumor development, progression, or metastasis in vivo remains unclear. To address this, here we examined whether Mint3 depletion affects tumor malignancy in MMTV-PyMT breast cancer model mice. In MMTV-PyMT mice, Mint3 depletion did not affect tumor onset and tumor growth, but attenuated lung metastases. Experimental lung metastasis of breast cancer Met-1 cells derived from MMTV-PyMT mice also decreased in Mint3-depleted mice, indicating that host Mint3 expression affected lung metastasis of MMTV-PyMT-derived breast cancer cells. Further bone marrow transplant experiments revealed that Mint3 in bone marrow-derived cells promoted lung metastasis in MMTV-PyMT mice. Thus, targeting Mint3 in bone marrow-derived cells might be a good strategy for preventing metastasis and improving the prognosis of breast cancer patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Clarifying the use of aggregated exposures in multilevel models: self-included vs. self-excluded measures.

    Directory of Open Access Journals (Sweden)

    Etsuji Suzuki

    Full Text Available BACKGROUND: Multilevel analyses are ideally suited to assess the effects of ecological (higher level and individual (lower level exposure variables simultaneously. In applying such analyses to measures of ecologies in epidemiological studies, individual variables are usually aggregated into the higher level unit. Typically, the aggregated measure includes responses of every individual belonging to that group (i.e. it constitutes a self-included measure. More recently, researchers have developed an aggregate measure which excludes the response of the individual to whom the aggregate measure is linked (i.e. a self-excluded measure. In this study, we clarify the substantive and technical properties of these two measures when they are used as exposures in multilevel models. METHODS: Although the differences between the two aggregated measures are mathematically subtle, distinguishing between them is important in terms of the specific scientific questions to be addressed. We then show how these measures can be used in two distinct types of multilevel models-self-included model and self-excluded model-and interpret the parameters in each model by imposing hypothetical interventions. The concept is tested on empirical data of workplace social capital and employees' systolic blood pressure. RESULTS: Researchers assume group-level interventions when using a self-included model, and individual-level interventions when using a self-excluded model. Analytical re-parameterizations of these two models highlight their differences in parameter interpretation. Cluster-mean centered self-included models enable researchers to decompose the collective effect into its within- and between-group components. The benefit of cluster-mean centering procedure is further discussed in terms of hypothetical interventions. CONCLUSIONS: When investigating the potential roles of aggregated variables, researchers should carefully explore which type of model-self-included or self

  2. Including the effects of filamentous bulking sludge during the simulation of wastewater treatment plants using a risk assessment model

    DEFF Research Database (Denmark)

    Flores Alsina, Xavier; Comas, J.; Rodriquez-Roda, I.

    2009-01-01

    The main objective of this paper is to demonstrate how including the occurrence of filamentous bulking sludge in a secondary clarifier model will affect the predicted process performance during the simulation of WWTPs. The IWA Benchmark Simulation Model No. 2 (BSM2) is hereby used as a simulation...

  3. Toward an animal model for antisocial behavior : parallels between mice and humans

    NARCIS (Netherlands)

    Sluyter, F; Arseneault, L; Moffitt, TE; Veenema, AH; de Boer, S; Koolhaas, JM

    The goal of this article is to examine whether mouse lines genetically selected for short and long attack latencies are good animal models for antisocial behavior in humans. To this end, we compared male Short and Long Attack Latency mice (SAL and LAL, respectively) with the extremes of the Dunedin

  4. Hypoxia facilitates neurogenic dural plasma protein extravasation in mice: a novel animal model for migraine pathophysiology.

    Science.gov (United States)

    Hunfeld, Anika; Segelcke, Daniel; Bäcker, Ingo; Mecheri, Badreddine; Hemmer, Kathrin; Dlugosch, Elisabeth; Andriske, Michael; Paris, Frank; Zhu, Xinran; Lübbert, Hermann

    2015-12-08

    Migraine animal models generally mimic the onset of attacks and acute treatment processes. A guinea pig model used the application of meta-chlorophenylpiperazine (mCPP) to trigger immediate dural plasma protein extravasation (PPE) mediated by 5-HT2B receptors. This model has predictive value for antimigraine drugs but cannot explain the delayed onset of efficacy of 5-HT2B receptor antagonists when clinically used for migraine prophylaxis. We found that mCPP failed to induce dural PPE in mice. Considering the role 5-HT2B receptors play in hypoxia-induced pulmonary vessel muscularization, we were encouraged to keep mice under hypoxic conditions and tested whether this treatment will render them susceptible to mCPP-induced dural PPE. Following four-week of hypoxia, PPE, associated with increased transendothelial transport, was induced by mCPP. The effect was blocked by sumatriptan. Chronic application of 5-HT2B receptor or nitric oxide synthase blockers during hypoxia prevented the development of susceptibility. Here we present a migraine model that distinguishes between a migraine-like state (hypoxic mice) and normal, normoxic mice and mimics processes that are related to chronic activation of 5-HT2B receptors under hypoxia. It seems striking, that chronic endogenous activation of 5-HT2B receptors is crucial for the sensitization since 5-HT2B receptor antagonists have strong, albeit delayed migraine prophylactic efficacy.

  5. Motor, emotional and cognitive deficits in adult BACHD mice : A model for Huntington's disease

    NARCIS (Netherlands)

    Abada, Yah-se K.; Schreiber, Rudy; Ellenbroek, Bart

    2013-01-01

    Rationale: Huntington's disease (HD) is characterized by progressive motor dysfunction, emotional disturbances and cognitive deficits. It is a genetic disease caused by an elongation of the polyglutamine repeats in the huntingtin gene. Whereas HD is a complex disorder, previous studies in mice model

  6. Development of luciferase tagged brain tumour models in mice for chemotherapy intervention studies.

    NARCIS (Netherlands)

    Kemper, E.M.; Leenders, W.P.J.; Kusters, B.; Lyons, S.; Buckle, T.; Heerschap, A.; Boogerd, W.; Beijnen, J.H.; Tellingen, O.

    2006-01-01

    The blood-brain barrier (BBB) is considered one of the major causes for the low efficacy of cytotoxic compounds against primary brain tumours. The aim of this study was to develop intracranial tumour models in mice featuring intact or locally disrupted BBB properties, which can be used in testing ch

  7. Toward an animal model for antisocial behavior : parallels between mice and humans

    NARCIS (Netherlands)

    Sluyter, F; Arseneault, L; Moffitt, TE; Veenema, AH; de Boer, S; Koolhaas, JM

    2003-01-01

    The goal of this article is to examine whether mouse lines genetically selected for short and long attack latencies are good animal models for antisocial behavior in humans. To this end, we compared male Short and Long Attack Latency mice (SAL and LAL, respectively) with the extremes of the Dunedin

  8. PPARγ agonist pioglitazone improves cerebellar dysfunction at pre-Aβ deposition stage in APPswe/PS1dE9 Alzheimer's disease model mice

    Energy Technology Data Exchange (ETDEWEB)

    Toba, Junya; Nikkuni, Miyu [Laboratory for Molecular Brain Science, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480 Japan (Japan); Ishizeki, Masato [Laboratory for Neurophysiology, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480 Japan (Japan); Yoshii, Aya; Watamura, Naoto [Laboratory for Molecular Brain Science, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480 Japan (Japan); Inoue, Takafumi [Laboratory for Neurophysiology, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480 Japan (Japan); Ohshima, Toshio, E-mail: ohshima@waseda.jp [Laboratory for Molecular Brain Science, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, 162-8480 Japan (Japan)

    2016-05-13

    Alzheimer's disease (AD) is one of the best known neurodegenerative diseases; it causes dementia and its pathological features include accumulation of amyloid β (Aβ) and neurofibrillary tangles (NFTs) in the brain. Elevated Cdk5 activity and CRMP2 phosphorylation have been reported in the brains of AD model mice at the early stage of the disease, but the significance thereof in human AD remains unelucidated. We have recently reported that Aβ accumulation in the cerebellum of AD model APPswe/PS1dE9 (APP/PS1) mice, and cerebellar dysfunctions, such as impairment of motor coordination ability and long-term depression (LTD) induction, at the pre-Aβ accumulation stage. In the present study, we found increased phosphorylation levels of CRMP2 as well as increased p35 protein levels in the cerebellum of APP/PS1 mice. Interestingly, we show that pioglitazone, an agonist of peroxisome proliferator-activated receptor γ, normalized the p35 protein and CRMP2 phosphorylation levels in the cerebellum. Impaired motor coordination ability and LTD in APP/PS1 mice were ameliorated by pioglitazone treatment at the pre-Aβ accumulation stage. These results suggest a correlation between CRMP2 phosphorylation and AD pathophysiology, and indicate the effectiveness of pioglitazone treatment at the pre-Aβ accumulation stage in AD model mice. -- Highlights: •Phosphorylation level of CRMP2 increased in the cerebellum of APP/PS1 mice. •p35 protein levels increased in the cerebellum of APP/PS1 mice. •Pioglitazone treatment improved cerebellar dysfunction of APP/PS1 mice.

  9. Optimization of an Image-Guided Laser-Induced Choroidal Neovascularization Model in Mice.

    Directory of Open Access Journals (Sweden)

    Yan Gong

    Full Text Available The mouse model of laser-induced choroidal neovascularization (CNV has been used in studies of the exudative form of age-related macular degeneration using both the conventional slit lamp and a new image-guided laser system. A standardized protocol is needed for consistent results using this model, which has been lacking. We optimized details of laser-induced CNV using the image-guided laser photocoagulation system. Four lesions with similar size were consistently applied per eye at approximately double the disc diameter away from the optic nerve, using different laser power levels, and mice of various ages and genders. After 7 days, the mice were sacrificed and retinal pigment epithelium/choroid/sclera was flat-mounted, stained with Isolectin B4, and imaged. Quantification of the area of the laser-induced lesions was performed using an established and constant threshold. Exclusion criteria are described that were necessary for reliable data analysis of the laser-induced CNV lesions. The CNV lesion area was proportional to the laser power levels. Mice at 12-16 weeks of age developed more severe CNV than those at 6-8 weeks of age, and the gender difference was only significant in mice at 12-16 weeks of age, but not in those at 6-8 weeks of age. Dietary intake of omega-3 long-chain polyunsaturated fatty acid reduced laser-induced CNV in mice. Taken together, laser-induced CNV lesions can be easily and consistently applied using the image-guided laser platform. Mice at 6-8 weeks of age are ideal for the laser-induced CNV model.

  10. IGE Model: An Extension of the Ideal Gas Model to Include Chemical Composition as Part of the Equilibrium State

    Directory of Open Access Journals (Sweden)

    Christopher P. Paolini

    2012-01-01

    Full Text Available The ideal gas (IG model is probably the most well-known gas models in engineering thermodynamics. In this paper, we extend the IG model into an ideal gas equilibrium (IGE model mixture model by incorporating chemical equilibrium calculations as part of the state evaluation. Through a simple graphical interface, users can set the atomic composition of a gas mixture. We have integrated this model into a thermodynamic web portal TEST (http://thermofluids.sdsu.edu/ that contains Java applets for various models for properties of pure substances. In the state panel of the IGE model, the known thermodynamic properties are entered. For a given pressure and temperature, the mixture's Gibbs function is minimized subject to atomic constraints and the equilibrium composition along with thermodynamic properties of the mixture are calculated and displayed. What is unique about this approach is that equilibrium computations are performed in the background, without requiring any major change in the familiar user interface used in other state daemons. Properties calculated by this equilibrium state daemon are compared with results from other established applications such as NASA CEA and STANJAN. Also, two different algorithms, an iterative approach and a direct approach based on minimizing different thermodynamic functions in different situation, are compared.

  11. OBLIMAP 2.0 : A fast climate model-ice sheet model coupler including online embeddable mapping routines

    NARCIS (Netherlands)

    Reerink, Thomas J.; Jan Van De Berg, Willem; Van De Wal, Roderik S W

    2016-01-01

    This paper accompanies the second OBLIMAP open-source release. The package is developed to map climate fields between a general circulation model (GCM) and an ice sheet model (ISM) in both directions by using optimal aligned oblique projections, which minimize distortions. The curvature of the surfa

  12. Environmental Enrichment Ameliorates Behavioral Impairments Modeling Schizophrenia in Mice Lacking Metabotropic Glutamate Receptor 5.

    Science.gov (United States)

    Burrows, Emma L; McOmish, Caitlin E; Buret, Laetitia S; Van den Buuse, Maarten; Hannan, Anthony J

    2015-07-01

    Schizophrenia arises from a complex interplay between genetic and environmental factors. Abnormalities in glutamatergic signaling have been proposed to underlie the emergence of symptoms, in light of various lines of evidence, including the psychotomimetic effects of NMDA receptor antagonists. Metabotropic glutamate receptor 5 (mGlu5) has also been implicated in the disorder, and has been shown to physically interact with NMDA receptors. To clarify the role of mGlu5-dependent behavioral expression by environmental factors, we assessed mGlu5 knockout (KO) mice after exposure to environmental enrichment (EE) or reared under standard conditions. The mGlu5 KO mice showed reduced prepulse inhibition (PPI), long-term memory deficits, and spontaneous locomotor hyperactivity, which were all attenuated by EE. Examining the cellular impact of genetic and environmental manipulation, we show that EE significantly increased pyramidal cell dendritic branching and BDNF protein levels in the hippocampus of wild-type mice; however, mGlu5 KO mice were resistant to these alterations, suggesting that mGlu5 is critical to these responses. A selective effect of EE on the behavioral response to the NMDA receptor antagonist MK-801 in mGlu5 KO mice was seen. MK-801-induced hyperlocomotion was further potentiated in enriched mGlu5 KO mice and treatment with MK-801 reinstated PPI disruption in EE mGlu5 KO mice only, a response that is absent under standard housing conditions. Together, these results demonstrate an important role for mGlu5 in environmental modulation of schizophrenia-related behavioral impairments. Furthermore, this role of the mGlu5 receptor is mediated by interaction with NMDA receptor function, which may inform development of novel therapeutics.

  13. Early Exercise Promotes Angiogenic Response in Mice Model of Myocardial Infarction

    Institute of Scientific and Technical Information of China (English)

    Wu Guifu; Du Zhimin; Hu Chenghen; Roger J. Laham

    2005-01-01

    Objectives Little is known about the mechanism of exercise-induced angiogenic response in ischemic myocardium. This study was designed to investigate the effects of exercise training on expression of vascular endothelial growth factor and angiogenesis in infarcted heart. Methods Fifty male FVB mice were divided into three subgroups to test various responses to exercise, including timedependent response of angiogenic factors to exercise training in intact heart (n=10) and infarcted heart (n=10), as well as exercise-induced angiogenic response in heart with myocardial infarction (MI) (n=30). The mice in the exercise-training groups were allowed to exercise daily at 1 hour per day for 7 days. Results VEGF protein expression was up-regulated by exercise training in time dependent fashion in mice with MI.Angiogenesis was evident by increased myocardial microvessels observed by PECAM-1 immunohistoc-hemical staining in post-MI exercise group (16.5±3.4)/0.4 mm2 versus post-MI sedentary mice ( 10±2.1 )/0.4 mm2 (P < 0.05). Cell proliferation assessment showed significantly higher (P < 0.05) number of BrdU positive cells in post MI mice in exercise group as opposed to sedentary post MI mice. 2%TTC staining disclosed a profound difference in the size of MI (18.25±2.93)% in exercise group vs sedentary group (29.26±7.64)% (P<0.05). Conclusions Activation and up-regulation of VEGF in infarcted mice heart may contributes the angiogenic response to exercise training at the early stage of myocardial infarction. This underscores the impact of exercise on angiogenesis in post myocardial infarction setting.

  14. CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: A new mammalian circadian oscillator model including the cAMP module

    Science.gov (United States)

    Wang, Jun-Wei; Zhou, Tian-Shou

    2009-12-01

    In this paper, we develop a new mathematical model for the mammalian circadian clock, which incorporates both transcriptional/translational feedback loops (TTFLs) and a cAMP-mediated feedback loop. The model shows that TTFLs and cAMP signalling cooperatively drive the circadian rhythms. It reproduces typical experimental observations with qualitative similarities, e.g. circadian oscillations in constant darkness and entrainment to light-dark cycles. In addition, it can explain the phenotypes of cAMP-mutant and Rev-erbα-/--mutant mice, and help us make an experimentally-testable prediction: oscillations may be rescued when arrhythmic mice with constitutively low concentrations of cAMP are crossed with Rev-erbα-/- mutant mice. The model enhances our understanding of the mammalian circadian clockwork from the viewpoint of the entire cell.

  15. The Benefits of Including Clinical Factors in Rectal Normal Tissue Complication Probability Modeling After Radiotherapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Defraene, Gilles, E-mail: gilles.defraene@uzleuven.be [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Van den Bergh, Laura [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Al-Mamgani, Abrahim [Department of Radiation Oncology, Erasmus Medical Center - Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Haustermans, Karin [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Heemsbergen, Wilma [Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Van den Heuvel, Frank [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Lebesque, Joos V. [Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

    2012-03-01

    Purpose: To study the impact of clinical predisposing factors on rectal normal tissue complication probability modeling using the updated results of the Dutch prostate dose-escalation trial. Methods and Materials: Toxicity data of 512 patients (conformally treated to 68 Gy [n = 284] and 78 Gy [n = 228]) with complete follow-up at 3 years after radiotherapy were studied. Scored end points were rectal bleeding, high stool frequency, and fecal incontinence. Two traditional dose-based models (Lyman-Kutcher-Burman (LKB) and Relative Seriality (RS) and a logistic model were fitted using a maximum likelihood approach. Furthermore, these model fits were improved by including the most significant clinical factors. The area under the receiver operating characteristic curve (AUC) was used to compare the discriminating ability of all fits. Results: Including clinical factors significantly increased the predictive power of the models for all end points. In the optimal LKB, RS, and logistic models for rectal bleeding and fecal incontinence, the first significant (p = 0.011-0.013) clinical factor was 'previous abdominal surgery.' As second significant (p = 0.012-0.016) factor, 'cardiac history' was included in all three rectal bleeding fits, whereas including 'diabetes' was significant (p = 0.039-0.048) in fecal incontinence modeling but only in the LKB and logistic models. High stool frequency fits only benefitted significantly (p = 0.003-0.006) from the inclusion of the baseline toxicity score. For all models rectal bleeding fits had the highest AUC (0.77) where it was 0.63 and 0.68 for high stool frequency and fecal incontinence, respectively. LKB and logistic model fits resulted in similar values for the volume parameter. The steepness parameter was somewhat higher in the logistic model, also resulting in a slightly lower D{sub 50}. Anal wall DVHs were used for fecal incontinence, whereas anorectal wall dose best described the other two endpoints

  16. Characterization of oral ulcer and pathological scar in nude mice model.

    Science.gov (United States)

    Sukhitashvili, N; Imnadze, I; Tabaghua, G; Gogilashvili, Q; Amiranashvili, I

    2012-04-01

    Ulceration of mouth mucosa is frequently occurs after injuries in oral cavity. Oral ulcers are relatively common and these lesions cause strong pain and discomfort. Frequently, injury of the oral tissues results in abnormal fibroblast activation and keloid formation. This pathological scar formation is often associates with pain and malfunction of the organ. To understand these phenomena and develop effective treatment, reproducible animal models have to be introduced. Athymic nude mice where used to create animal models. 1% HCl acid solution was used for chemical damage of the mucosa tissue. Surgical operation was performed to create traumatic injury in the mouse oral cavity. Tissues were analyzed using immunohistochemistry methods. All of the HCl treated animals developed ulcers on the skin and mucosa of the oral cavity. Most of the mice on the place of surgical wound developed keloid tissue. Mice in which we induced pathological processes of the oral tissue, did not gain body weight. Moreover their mass had tendency to decrease. Hematoxilyn-eosin staining of the ulcerated mice tissues revealed extended coagulation necrosis - covering all tissue layers of the oral cavity. Strong local inflammatory cell infiltration and absence of proliferative cells has been demonstrated in these ulcerated and adjusted oral tissues. Morphological analysis of scar tissue revealed fibrotic hypertrophy of the injured oral tissues in these animals with the expressed infiltration of inflammatory cells. Our animal models reflect morphology of the specific injury and functionally imitate the disease.

  17. Establishment of a Novel Bladder Cancer Xenograft Model in Humanized Immunodeficient Mice

    Directory of Open Access Journals (Sweden)

    Zhen Gong

    2015-10-01

    Full Text Available Background/Aims: The aim of this study was to develop a novel model by transplanting human bladder cancer xenografts into humanized immunodeficient mice (SCID. Methods: The animals first underwent sublethal irradiation and then were subjected to simultaneous transplantation of human lymphocytes (5 × 107 cells/mouse i.p. and human bladder cancer cells (3 × 106 cells/mouse s.c.. Results: The xenografts developed in all 12 mice that had received bladder cancer BIU-87 cells, and the tumor specimens were evaluated histologically. All 6 model mice expressed human CD3 mRNA and/or protein in the peripheral blood, spleens and xenografts. The mean proportion of human CD3+ cells was 19% with a level of human IgG 532.4µ/ml in the peripheral blood at Week 6 after transplant inoculation. The re-constructed human immune system in these mice was confirmed to be functional by individual in vitro testing of their proliferative, secretory and cytotoxic responses. Conclusion: The successful engraftment of the human bladder cancer xenografts and the establishment of the human immune system in our in vivo model described here may provide a useful tool for the development of novel therapeutic strategies targeting at bladder cancer.

  18. Seizure susceptibility of neuropeptide-Y null mutant mice in amygdala kindling and chemical-induced seizure models.

    Science.gov (United States)

    Shannon, Harlan E; Yang, Lijuan

    2004-01-01

    Neuropeptide Y (NPY) administered exogenously is anticonvulsant, and, NPY null mutant mice are more susceptible to kainate-induced seizures. In order to better understand the potential role of NPY in epileptogenesis, the present studies investigated the development of amygdala kindling, post-kindling seizure thresholds, and anticonvulsant effects of carbamazepine and levetiracetam in 129S6/SvEv NPY(+/+) and NPY(-/-) mice. In addition, susceptibility to pilocarpine- and kainate-induced seizures was compared in NPY(+/+) and (-/-) mice. The rate of amygdala kindling development did not differ in the NPY(-/-) and NPY(+/+) mice either when kindling stimuli were presented once daily for at least 20 days, or, 12 times daily for 2 days. However, during kindling development, the NPY(-/-) mice had higher seizure severity scores and longer afterdischarge durations than the NPY(+/+) mice. Post-kindling, the NPY(-/-) mice had markedly lower afterdischarge thresholds and longer afterdischarge durations than NPY (+/+) mice. Carbamazepine and levetiracetam increased the seizure thresholds of both NPY (-/-) and (+/+) mice. In addition, NPY (-/-) mice had lower thresholds for both kainate- and pilocarpine-induced seizures. The present results in amygdala kindling and chemical seizure models suggest that NPY may play a more prominent role in determining seizure thresholds and severity of seizures than in events leading to epileptogenesis. In addition, a lack of NPY does not appear to confer drug-resistance in that carbamazepine and levetiracetam were anticonvulsant in both wild type (WT) and NPY null mutant mice.

  19. Novel metastasis model of human lung cancer in SCID mice depleted of NK cells.

    Science.gov (United States)

    Yano, S; Nishioka, Y; Izumi, K; Tsuruo, T; Tanaka, T; Miyasaka, M; Sone, S

    1996-07-17

    Metastasis is a critical problem in the treatment of human lung cancer. Thus, a suitable animal model of metastasis of human lung cancer is required for in vivo biological and preclinical studies. In this study, we tried to establish a suitable model for this, using SCID mice. Neither human SCLC H69/VP cells (5 x 10(6)) nor squamous-cell carcinoma RERF-LC-AI cells (1 x 10(6)), injected through a tail vein, formed metastases in untreated SCID mice. Pre-treatment of SCID mice with anti-asialo GM1 serum resulted in only a few metastases of H69/VP cells, but pre-treatment with anti-mouse IL-2 receptor beta chain Ab (TM-beta 1) resulted in numerous lymph-node metastases 56 days after tumor inoculation. H69/VP-M cells, an in vivo-selected variant line, formed significant numbers of lymph-node metastases even in SCID mice pre-treated with anti-asialo GM1 serum. SCID mice depleted of NK cells by treatment with TM-beta 1 showed different patterns of metastasis when inoculated intravenously with the 2 different human lung cancer cell lines (H69/VP and RERF-LC-AI cells): H69/VP cells formed metastases mainly in systemic lymph nodes and the liver, whereas RERF-LC-AI cells formed metastases mainly in the liver and kidneys, with only a few in lymph nodes. A histopathological study showed that the metastatic colonies consisted of cancer cells. The numbers of metastatic colonies formed by the 2 cell lines increased with the number of cells inoculated. TM-beta 1 treatment of SCID mice efficiently removed NK cells from peripheral blood for at least 6 weeks, whereas, after treatment of the mice with anti-asialo GM1 serum, NK cells were recovered within 9 days. These findings suggest that NK-cell-depleted SCID mice may be useful as a model in biological and pre-clinical studies on metastasis of human lung cancer.

  20. Functional and Muscular Adaptations in an Experimental Model for Isometric Strength Training in Mice

    OpenAIRE

    Karsten Krüger; Gessner, Denise K; Michael Seimetz; Jasmin Banisch; Robert Ringseis; Klaus Eder; Norbert Weissmann; Mooren, Frank C.

    2013-01-01

    Exercise training induces muscular adaptations that are highly specific to the type of exercise. For a systematic study of the differentiated exercise adaptations on a molecular level mouse models have been used successfully. The aim of the current study was to develop a suitable mouse model of isometric strength exercise training characterized by specific adaptations known from strength training. C57BL/6 mice performed an isometric strength training (ST) for 10 weeks 5 days/week. Additionall...

  1. A Model of Alcohol Drinking under an Intermittent Access Schedule Using Group-Housed Mice

    Science.gov (United States)

    Smutek, Magdalena; Turbasa, Mateusz; Sikora, Magdalena; Piechota, Marcin; Zajdel, Joanna; Przewlocki, Ryszard; Parkitna, Jan Rodriguez

    2014-01-01

    Here, we describe a new model of voluntary alcohol drinking by group-housed mice. The model employs sensor-equipped cages that track the behaviors of the individual animals via implanted radio chips. After the animals were allowed intermittent access to alcohol (three 24 h intervals every week) for 4 weeks, the proportions of licks directed toward bottles containing alcohol were 50.9% and 39.6% for the male and female mice, respectively. We used three approaches (i.e., quinine adulteration, a progressive ratio schedule and a schedule involving a risk of punishment) to test for symptoms of compulsive alcohol drinking. The addition of 0.01% quinine to the alcohol solution did not significantly affect intake, but 0.03% quinine induced a greater than 5-fold reduction in the number of licks on the alcohol bottles. When the animals were required to perform increasing numbers of instrumental responses to obtain access to the bottle with alcohol (i.e., a progressive ratio schedule), they frequently reached a maximum of 21 responses irrespective of the available reward. Although the mice rarely achieved higher response criteria, the number of attempts was ∼10 times greater in case of alcohol than water. We have developed an approach for mapping social interactions among animals that is based on analysis of the sequences of entries into the cage corners. This approach allowed us to identify the mice that followed other animals in non-random fashions. Approximately half of the mice displayed at least one interaction of this type. We have not yet found a clear correlation between imitative behavior and relative alcohol preference. In conclusion, the model we describe avoids the limitations associated with testing isolated animals and reliably leads to stable alcohol drinking. Therefore, this model may be well suited to screening for the effects of genetic mutations or pharmacological treatments on alcohol-induced behaviors. PMID:24804807

  2. Aging-like skin changes in metabolic syndrome model mice are mediated by mineralocorticoid receptor signaling.

    Science.gov (United States)

    Nagase, Takashi; Akase, Tomoko; Sanada, Hiromi; Minematsu, Takeo; Ibuki, Ai; Huang, Lijuan; Asada, Mayumi; Yoshimura, Kotaro; Nagase, Miki; Shimada, Tsutomu; Aburada, Masaki; Nakagami, Gojiro; Sugama, Junko

    2013-02-01

    Aging is accelerated, at least in part, by pathological condition such as metabolic syndrome (MetS), and various molecular pathways such as oxidative stress are common mediators of aging and MetS. We previously developed the aging-like skin model by single ultraviolet (UV) irradiation on the MetS model mice. Recent studies revealed that mineralocorticoid receptor (MR) signaling plays a pivotal role for various tissue inflammation and damages in MetS. Although previous studies reported that MR is expressed in the skin and that overexpression of MR in the skin resulted in the skin atrophy, the physiological or pathological functions of MR in the skin are not fully elucidated. Here, we show the involvement of MR signaling in the aging-like skin changes in our own model. Elevations of oxidative stress and inflammation markers were observed in the MetS mice, and the UV-evoked aging-like skin damages were attenuated by topical antioxidant. MR expression was higher in the MetS mouse skin, and notably, expression of its effecter gene Sgk1 was significantly upregulated in the aging-like skin in the UV-irradiated MetS mice. Furthermore, topical application of MR antagonist spironolactone suppressed Sgk1 expression, oxidative stress, inflammation, and the aging-like changes in the skin. The 2-week UV onto the non-MetS mice, the more usual photoaging model, resulted in the skin damages mostly equivalent to the MetS mice with single UV, but they were not associated with upregulation of MR signaling. Our studies suggested an unexpected role of MR signaling in the skin aging in MetS status.

  3. Down Syndrome Cognitive Phenotypes Modeled in Mice Trisomic for All HSA 21 Homologues

    Science.gov (United States)

    Belichenko, Pavel V.; Kleschevnikov, Alexander M.; Becker, Ann; Wagner, Grant E.; Lysenko, Larisa V.; Yu, Y. Eugene; Mobley, William C.

    2015-01-01

    Down syndrome (DS), trisomy for chromosome 21, is the most common genetic cause of intellectual disability. The genomic regions on human chromosome 21 (HSA21) are syntenically conserved with regions on mouse chromosomes 10, 16, and 17 (Mmu10, Mmu16, and Mmu17). Recently, we created a genetic model of DS which carries engineered duplications of all three mouse syntenic regions homologous to HSA21. This ‘triple trisomic’ or TTS model thus represents the most complete and accurate murine model currently available for experimental studies of genotype-phenotype relationships in DS. Here we extended our initial studies of TTS mice. Locomotor activity, stereotypic and repetitive behavior, anxiety, working memory, long-term memory, and synaptic plasticity in the dentate gyrus were examined in the TTS and wild-type (WT) control mice. Changes in locomotor activity were most remarkable for a significant increase in ambulatory time and a reduction in average velocity of TTS mice. No changes were detected in repetitive and stereotypic behavior and in measures of anxiety. Working memory showed no changes when tested in Y-maze, but deficiency in a more challenging T-maze test was detected. Furthermore, long-term object recognition memory was significantly reduced in the TTS mice. These changes were accompanied by deficient long-term potentiation in the dentate gyrus, which was restored to the WT levels following blockade of GABAA receptors with picrotoxin (100 μM). TTS mice thus demonstrated a number of phenotypes characteristic of DS and may serve as a new standard by which to evaluate and direct findings in other less complete models of DS. PMID:26230397

  4. Mouse embryonic stem cells give rise to gut-like morphogenesis, including intestinal stem cells, in the embryoid body model.

    Science.gov (United States)

    Konuma, Noriyoshi; Wakabayashi, Kumiko; Matsumoto, Taro; Kusumi, Yoshiaki; Masuko, Takayuki; Iribe, Yuji; Mitsumata, Masako; Okano, Hideyuki; Kusafuka, Takeshi; Mugishima, Hideo

    2009-01-01

    Embryonic stem (ES) cells have been proposed as candidates for cell replacement therapy in patients with intestinal failure because these cells can be expanded indefinitely without losing their pluripotent phenotype. We investigated the differentiation capacity of mouse ES cells into gut-like structures, including intestinal stem cells, and defined culture conditions for efficient induction of formation of these structures. ES cell-derived gut-like structures (ES-guts) were reproducibly induced in developing embryoid bodies (EBs) by day 21 of differentiation culture. ES-guts contained an endodermal epithelium, a smooth muscle layer, interstitial cells of Cajal, and enteric neurons and showed spontaneous contraction. Transplantation of ES-guts under the kidney capsules of immunodeficient mice induced formation of highly differentiated epithelium composed of absorptive cells and goblet cells in the grafts. Immunoreactivity for Musashi-1 (Msi-1), a marker of intestinal stem cells, was detected in 1.9% of the columnar epithelial cells in the graft. Culture with 0.1% dimethyl sulfoxide increased the numbers of ES-guts in EBs, and serum-replacement (SR) culture, in comparison to standard ES culture containing 15% serum, increased the area ratio of ES-guts to EBs. SR culture also promoted maturation of epithelium to form a single layer of columnar epithelial cells, including absorptive cells and goblet cells. Expression of Msi-1 mRNA and protein was significantly enhanced when EBs were cultured under SR conditions. In conclusion, SR conditions efficiently induce formation of ES-guts and promote differentiation of epithelium, including intestinal stem cells. These results suggest the feasibility of cell-based therapy for intestinal failure based on ES cell culture systems.

  5. A mechanistic model of infection: why duration and intensity of contacts should be included in models of disease spread

    Directory of Open Access Journals (Sweden)

    Smieszek Timo

    2009-11-01

    Full Text Available Abstract Background Mathematical models and simulations of disease spread often assume a constant per-contact transmission probability. This assumption ignores the heterogeneity in transmission probabilities, e.g. due to the varying intensity and duration of potentially contagious contacts. Ignoring such heterogeneities might lead to erroneous conclusions from simulation results. In this paper, we show how a mechanistic model of disease transmission differs from this commonly used assumption of a constant per-contact transmission probability. Methods We present an exposure-based, mechanistic model of disease transmission that reflects heterogeneities in contact duration and intensity. Based on empirical contact data, we calculate the expected number of secondary cases induced by an infector (i for the mechanistic model and (ii under the classical assumption of a constant per-contact transmission probability. The results of both approaches are compared for different basic reproduction numbers R0. Results The outcomes of the mechanistic model differ significantly from those of the assumption of a constant per-contact transmission probability. In particular, cases with many different contacts have much lower expected numbers of secondary cases when using the mechanistic model instead of the common assumption. This is due to the fact that the proportion of long, intensive contacts decreases in the contact dataset with an increasing total number of contacts. Conclusion The importance of highly connected individuals, so-called super-spreaders, for disease spread seems to be overestimated when a constant per-contact transmission probability is assumed. This holds particularly for diseases with low basic reproduction numbers. Simulations of disease spread should weight contacts by duration and intensity.

  6. Mathematical Model of Two Phase Flow in Natural Draft Wet-Cooling Tower Including Flue Gas Injection

    Directory of Open Access Journals (Sweden)

    Hyhlík Tomáš

    2016-01-01

    Full Text Available The previously developed model of natural draft wet-cooling tower flow, heat and mass transfer is extended to be able to take into account the flow of supersaturated moist air. The two phase flow model is based on void fraction of gas phase which is included in the governing equations. Homogeneous equilibrium model, where the two phases are well mixed and have the same velocity, is used. The effect of flue gas injection is included into the developed mathematical model by using source terms in governing equations and by using momentum flux coefficient and kinetic energy flux coefficient. Heat and mass transfer in the fill zone is described by the system of ordinary differential equations, where the mass transfer is represented by measured fill Merkel number and heat transfer is calculated using prescribed Lewis factor.

  7. From Mice to Men: research models of developmental programming

    OpenAIRE

    2013-01-01

    Developmental programming can be defined as a response to a specific challenge to the mammalian organism during a critical developmental time window that alters the trajectory of development with persistent effects on offspring phenotype and predisposition to future illness. We focus on the need for studies in relevant, well-characterized animal models in the context of recent research discoveries on the challenges, mechanisms and outcomes of developmental programming. We discuss commonalitie...

  8. Shank mutant mice as an animal model of autism

    OpenAIRE

    Yoo, Juyoun; Bakes, Joseph; Bradley, Clarrisa; Graham L. Collingridge; Kaang, Bong-Kiun

    2014-01-01

    In this review, we focus on the role of the Shank family of proteins in autism. In recent years, autism research has been flourishing. With genetic, molecular, imaging and electrophysiological studies being supported by behavioural studies using animal models, there is real hope that we may soon understand the fundamental pathology of autism. There is also genuine potential to develop a molecular-level pharmacological treatment that may be able to deal with the most severe symptoms of autism,...

  9. A unified analytical drain current model for Double-Gate Junctionless Field-Effect Transistors including short channel effects

    Science.gov (United States)

    Raksharam; Dutta, Aloke K.

    2017-04-01

    In this paper, a unified analytical model for the drain current of a symmetric Double-Gate Junctionless Field-Effect Transistor (DG-JLFET) is presented. The operation of the device has been classified into four modes: subthreshold, semi-depleted, accumulation, and hybrid; with the main focus of this work being on the accumulation mode, which has not been dealt with in detail so far in the literature. A physics-based model, using a simplified one-dimensional approach, has been developed for this mode, and it has been successfully integrated with the model for the hybrid mode. It also includes the effect of carrier mobility degradation due to the transverse electric field, which was hitherto missing in the earlier models reported in the literature. The piece-wise models have been unified using suitable interpolation functions. In addition, the model includes two most important short-channel effects pertaining to DG-JLFETs, namely the Drain Induced Barrier Lowering (DIBL) and the Subthreshold Swing (SS) degradation. The model is completely analytical, and is thus computationally highly efficient. The results of our model have shown an excellent match with those obtained from TCAD simulations for both long- and short-channel devices, as well as with the experimental data reported in the literature.

  10. Dipole model analysis of highest precision HERA data, including very low Q{sup 2}'s

    Energy Technology Data Exchange (ETDEWEB)

    Luszczak, A. [Cracow Univ. of Technology (Poland); Kowalski, H. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-12-15

    We analyse, within a dipole model, the final, inclusive HERA DIS cross section data in the low χ region, using fully correlated errors. We show, that these highest precision data are very well described within the dipole model framework starting from Q{sup 2} values of 3.5 GeV{sup 2} to the highest values of Q{sup 2}=250 GeV{sup 2}. To analyze the saturation effects we evaluated the data including also the very low 0.35including this region show a preference of the saturation ansatz.

  11. The MV Model of the Color Glass Condensate for a Finite Number of Sources Including Coulomb Interactions

    CERN Document Server

    McLerran, Larry

    2016-01-01

    We modify the McLerran-Venugopalan model to include only a finite number of sources of color charge. We argue that Coulombic interactions between these color charges generates a source-source correlation function that properly includes the effects of color charge screening, a generalization of Debye screening for the Color Glass Condensate. Such a model may be useful for computing angular harmonics of flow measured in high energy hadron collisions for small systems. In this paper we provide a basic formulation of the problem on a lattice.

  12. Dynamic model of a micro-tubular solid oxide fuel cell stack including an integrated cooling system

    Science.gov (United States)

    Hering, Martin; Brouwer, Jacob; Winkler, Wolfgang

    2017-02-01

    A novel dynamic micro-tubular solid oxide fuel cell (MT-SOFC) and stack model including an integrated cooling system is developed using a quasi three-dimensional, spatially resolved, transient thermodynamic, physical and electrochemical model that accounts for the complex geometrical relations between the cells and cooling-tubes. The modeling approach includes a simplified tubular geometry and stack design including an integrated cooling structure, detailed pressure drop and gas property calculations, the electrical and physical constraints of the stack design that determine the current, as well as control strategies for the temperature. Moreover, an advanced heat transfer balance with detailed radiative heat transfer between the cells and the integrated cooling-tubes, convective heat transfer between the gas flows and the surrounding structures and conductive heat transfer between the solid structures inside of the stack, is included. The detailed model can be used as a design basis for the novel MT-SOFC stack assembly including an integrated cooling system, as well as for the development of a dynamic system control strategy. The evaluated best-case design achieves very high electrical efficiency between around 75 and 55% in the entire power density range between 50 and 550 mW /cm2 due to the novel stack design comprising an integrated cooling structure.

  13. Development of a PBPK model for monoclonal antibodies and simulation of human and mice PBPK of a radiolabelled monoclonal antibody.

    Science.gov (United States)

    Heiskanen, Tomi; Heiskanen, Tomas; Kairemo, Kalevi

    2009-01-01

    Physiology based pharmacokinetic (PBPK) modeling and simulation is a useful method for prediction of biodistribution of both macromolecules and small molecules. It can enhance our understanding of the underlying mechanisms of biodistribution and hence may help in rational design of macromolecules used as diagnostic and therapeutic agents. In this review we discuss PBPK modeling and simulation of a radiolabelled Monoclonal Antibody ((111)In-DOTA-hAFP31 IgG) ("MAB") in mice without tumor and in a human with tumor. This study is part of Xemet Co.'s effort to develop a more accurate and reliable PBPK model and simulation platform, which is applicable both for small molecules and macromolecules. The simulated results were fitted to experimental time series data by varying parameters which were not fixed a priori. It was demonstrated that the PBPK model describes the main features of the pharmacokinetics of the studied systems. It was also shown that simulation can be used for evaluating the parameters of the system and scaling up the pharmacokinetics of MAB from mice to man. We identified several areas of improvement and further development needed to improve the accuracy of PBPK simulation for MAB and other macromolecules. It was concluded that the transvascular permeabilities are the most important parameters and more research is needed to enable prediction of permeabilities from molecular characteristics of macromolecules. It would also be necessary to understand better and describe with a more detailed model the microstructure of the tumor and to measure or predict the antigen concentration in tumor. Non-specific, non-saturable binding in other organs/tissues should be understood better and the kinetic constants of the binding should be measured experimentally. Although the metabolism and clearance were neglected in this study they need to be included in more detailed studies. Also the intracellular trafficking of macromolecules, which was not included in this study

  14. Does brain slices from pentylenetetrazole-kindled mice provide a more predictive screening model for antiepileptic drugs?

    Science.gov (United States)

    Hansen, Suzanne L; Sterjev, Zoran; Werngreen, Marie; Simonsen, Bodil J; Knudsen, Katrine E; Nielsen, Ane H; Pedersen, Mikael E; Badolo, Lassiana; Kristiansen, Uffe; Vestergaard, Henrik T

    2012-05-05

    The cortical wedge is a commonly applied model for in vitro screening of new antiepileptic drugs (AEDs) and has been extensively used in characterization of well-known AEDs. However, the predictive validity of this model as a screening model has been questioned as, e.g., carbamazepine has been reported to lack effect in this model. The neuroplastic changes induced in acute and chronic animal models of epilepsy are known to affect the pharmacological profile of AEDs in vivo. Hence, we investigated whether brain slices from pentylenetetrazole (PTZ)-kindled animals could provide a more predictive screening model for AEDs. To this end, we compared the in vitro and in vivo pharmacological profile of several selected AEDs (phenobarbital, phenytoin, tiagabine, fosphenytoin, valproate, and carbamazepine) along with citalopram using the PTZ-kindled model and brain slices from naïve, saline-injected and PTZ-kindled mice. Our data suggest that the use of slices from PTZ-kindled mice in the cortical wedge does not increase the predictive validity of the model as an in vitro screening model for AEDs. Traditionally, the incidence of certain seizure types is widely used as a measure to characterize drug action in animal models of epilepsy. In our study, the ant