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Sample records for intravenous challenge model

  1. Cabotegravir long acting injection protects macaques against intravenous challenge with SIVmac251.

    Science.gov (United States)

    Andrews, Chasity D; Bernard, Leslie St; Poon, Amanda Yee; Mohri, Hiroshi; Gettie, Natanya; Spreen, William R; Gettie, Agegnehu; Russell-Lodrigue, Kasi; Blanchard, James; Hong, Zhi; Ho, David D; Markowitz, Martin

    2017-02-20

    We evaluated the effectiveness of cabotegravir (CAB; GSK1265744 or GSK744) long acting as preexposure prophylaxis (PrEP) against intravenous simian immunodeficiency virus (SIV) challenge in a model that mimics blood transfusions based on the per-act probability of infection. CAB long acting is an integrase strand transfer inhibitor formulated as a 200 mg/ml injectable nanoparticle suspension that is an effective PrEP agent against rectal and vaginal simian/human immunodeficiency virus transmission in macaques. Three groups of rhesus macaques (n = 8 per group) were injected intramuscularly with CAB long acting and challenged intravenously with 17 animal infectious dose 50% SIVmac251 on week 2. Group 1 was injected with 50 mg/kg on week 0 and 4 to evaluate the protective efficacy of the CAB long-acting dose used in macaque studies mimicking sexual transmission. Group 2 was injected with 50 mg/kg on week 0 to evaluate the necessity of the second injection of CAB long acting for protection against intravenous challenge. Group 3 was injected with 25 mg/kg on week 0 and 50 mg/kg on week 4 to correlate CAB plasma concentrations at the time of challenge with protection. Five additional macaques remained untreated as controls. CAB long acting was highly protective with 21 of the 24 CAB long-acting-treated macaques remaining aviremic, resulting in 88% protection. The plasma CAB concentration at the time of virus challenge appeared to be more important for protection than sustaining therapeutic plasma concentrations with the second CAB long acting injection. These results support the clinical investigation of CAB long acting as PrEP in people who inject drugs.

  2. Modelling Framework and Assistive Device for Peripheral Intravenous Injections

    Science.gov (United States)

    Kam, Kin F.; Robinson, Martin P.; Gilbert, Mathew A.; Pelah, Adar

    2016-02-01

    Intravenous access for blood sampling or drug administration that requires peripheral venepuncture is perhaps the most common invasive procedure practiced in hospitals, clinics and general practice surgeries.We describe an idealised mathematical framework for modelling the dynamics of the peripheral venepuncture process. Basic assumptions of the model are confirmed through motion analysis of needle trajectories during venepuncture, taken from video recordings of a skilled practitioner injecting into a practice kit. The framework is also applied to the design and construction of a proposed device for accurate needle guidance during venepuncture administration, assessed as consistent and repeatable in application and does not lead to over puncture. The study provides insights into the ubiquitous peripheral venepuncture process and may contribute to applications in training and in the design of new devices, including for use in robotic automation.

  3. GH response to intravenous clonidine challenge correlates with history of childhood trauma in personality disorder.

    Science.gov (United States)

    Lee, Royce J; Fanning, Jennifer R; Coccaro, Emil F

    2016-05-01

    Childhood trauma is a risk factor for personality disorder. We have previously shown that childhood trauma is associated with increased central corticotrophin-releasing hormone concentration in adults with personality disorder. In the brain, the release of corticotrophin-releasing hormone can be stimulated by noradrenergic neuronal activity, raising the possibility that childhood trauma may affect the hypothalamic-pituitary adrenal (HPA) axis by altering brain noradrenergic function. In this study, we sought to test the hypothesis that childhood trauma is associated with blunted growth hormone response to the α-2 adrenergic autoreceptor agonist clonidine. All subjects provided written informed consent. Twenty personality disordered and twenty healthy controls (without personality disorder or Axis I psychopathology) underwent challenge with clonidine, while plasma Growth Hormone (GH) concentration was monitored by intravenous catheter. On a different study session, subjects completed the Childhood Trauma Questionnaire and underwent diagnostic interviews. Contrary to our a priori hypothesis, childhood trauma was associated with enhanced GH response to clonidine. This positive relationship was present in the group of 40 subjects and in the subgroup 20 personality disordered subjects, but was not detected in the healthy control subjects when analyzed separately. The presence of personality disorder was unrelated to the magnitude of GH response. Childhood trauma is positively correlated with GH response to clonidine challenge in adults with personality disorder. Enhanced rather that blunted GH response differentiates childhood trauma from previously identified negative predictors of GH response, such as anxiety or mood disorder. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Stable-label intravenous glucose tolerance test minimal model

    International Nuclear Information System (INIS)

    Avogaro, A.; Bristow, J.D.; Bier, D.M.; Cobelli, C.; Toffolo, G.

    1989-01-01

    The minimal model approach to estimating insulin sensitivity (Sl) and glucose effectiveness in promoting its own disposition at basal insulin (SG) is a powerful tool that has been underutilized given its potential applications. In part, this has been due to its inability to separate insulin and glucose effects on peripheral uptake from their effects on hepatic glucose inflow. Prior enhancements, with radiotracer labeling of the dosage, permit this separation but are unsuitable for use in pregnancy and childhood. In this study, we labeled the intravenous glucose tolerance test (IVGTT) dosage with [6,6- 2 H 2 ]glucose, [2- 2 H]glucose, or both stable isotopically labeled glucose tracers and modeled glucose kinetics in six postabsorptive, nonobese adults. As previously found with the radiotracer model, the tracer-estimated S*l derived from the stable-label IVGTT was greater than Sl in each case except one, and the tracer-estimated SG* was less than SG in each instance. More importantly, however, the stable-label IVGTT estimated each parameter with an average precision of +/- 5% (range 3-9%) compared to average precisions of +/- 74% (range 7-309%) for SG and +/- 22% (range 3-72%) for Sl. In addition, because of the different metabolic fates of the two deuterated tracers, there were minor differences in basal insulin-derived measures of glucose effectiveness, but these differences were negligible for parameters describing insulin-stimulated processes. In conclusion, the stable-label IVGTT is a simple, highly precise means of assessing insulin sensitivity and glucose effectiveness at basal insulin that can be used to measure these parameters in individuals of all ages, including children and pregnant women

  5. Hydropower Modeling Challenges

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, Brady [National Renewable Energy Lab. (NREL), Golden, CO (United States); Andrade, Juan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cohen, Stuart [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brinkman, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brancucci Martinez-Anido, Carlo [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-04-19

    Hydropower facilities are important assets for the electric power sector and represent a key source of flexibility for electric grids with large amounts of variable generation. As variable renewable generation sources expand, understanding the capabilities and limitations of the flexibility from hydropower resources is important for grid planning. Appropriately modeling these resources, however, is difficult because of the wide variety of constraints these plants face that other generators do not. These constraints can be broadly categorized as environmental, operational, and regulatory. This report highlights several key issues involving incorporating these constraints when modeling hydropower operations in terms of production cost and capacity expansion. Many of these challenges involve a lack of data to adequately represent the constraints or issues of model complexity and run time. We present several potential methods for improving the accuracy of hydropower representation in these models to allow for a better understanding of hydropower's capabilities.

  6. CHARACTERIZATION OF AN INTRAVENOUS LIPOPOLYSACCHARIDE INFLAMMATION MODEL IN BROILER CHICKENS

    OpenAIRE

    De Boever , Sandra; Croubels , Siska; Meyer , Evelyne; Sys , Stanislas; Beyaert , Rudi; Ducatelle , Richard; De Backer , Patrick

    2009-01-01

    Abstract Intravenous administration of lipopolysaccharide (LPS) from Escherichia coli O127:B8 at a dose of 1,500,000 units/kg BW evoked a hypothermic response followed by a fever phase in five week old broiler chickens. The hypothermic phase coincided with a severe decrease in blood pressure. We assume that this decrease in blood pressure is, at least partly, responsible for the hypothermic phase of the body temperature curve. LPS administration also caused a decrease in circulatin...

  7. Challenges in edge modeling

    International Nuclear Information System (INIS)

    Schneider, R.

    2007-01-01

    Fluid models like B2, UEDGE or EDGE2D are the working horses for scrape-off layer physics, both for design and experimental support. The concept of a numerical tokamak, aiming at a predictive code for ITER, triggers the need to re-assess the available tools and their necessary extensions. These additional physics issues will be summarized from a personal point-of-view. Depending on the specific problem, several complexity levels of scrape-off layer models will be needed. Therefore, a hierarchy of tools is necessary, which will be discussed. Furthermore, the experience existing in other scientific fields with multi-scale problems and modeling should be used. Here, the coupling of different length and time scales are in particular of interest for fusion problems. (author)

  8. Synchrotron-based intravenous cerebral angiography in a small animal model

    International Nuclear Information System (INIS)

    Kelly, Michael E; Schueltke, Elisabeth; Fiedler, Stephan; Nemoz, Christian; Guzman, Raphael; Corde, Stephanie; Esteve, Francois; LeDuc, Geraldine; Juurlink, Bernhard H J; Meguro, Kotoo

    2007-01-01

    K-edge digital subtraction angiography (KEDSA), a recently developed synchrotron-based technique, utilizes monochromatic radiation and allows acquisition of high-quality angiography images after intravenous administration of contrast agent. We tested KEDSA for its suitability for intravenous cerebral angiography in an animal model. Adult male New Zealand rabbits were subjected to either angiography with conventional x-ray equipment or synchrotron-based intravenous KEDSA, using an iodine-based contrast agent. Angiography with conventional x-ray equipment after intra-arterial administration of contrast agent demonstrated the major intracranial vessels but no smaller branches. KEDSA was able to visualize the major intracranial vessels as well as smaller branches in both radiography mode (planar images) and tomography mode. Visualization was achieved with as little as 0.5 ml kg -1 of iodinated contrast material. We were able to obtain excellent visualization of the cerebral vasculature in an animal model using intravenous injection of contrast material, using synchrotron-based KEDSA

  9. A Neospora caninum vaccine using recombinant proteins fails to prevent foetal infection in pregnant cattle after experimental intravenous challenge.

    Science.gov (United States)

    Hecker, Yanina P; Cóceres, Verónica; Wilkowsky, Silvina E; Jaramillo Ortiz, José M; Morrell, Eleonora L; Verna, Andrea E; Ganuza, Agustina; Cano, Dora B; Lischinsky, Lilian; Angel, Sergio O; Zamorano, Patricia; Odeón, Anselmo C; Leunda, María R; Campero, Carlos M; Morein, Bror; Moore, Dadín P

    2014-12-15

    The aim of the present study was to evaluate the immunogenicity and protective efficacy of rNcSAG1, rNcHSP20 and rNcGRA7 recombinant proteins formulated with immune stimulating complexes (ISCOMs) in pregnant heifers against vertical transmission of Neospora caninum. Twelve pregnant heifers were divided into 3 groups of 4 heifers each, receiving different formulations before mating. Immunogens were administered twice subcutaneously: group A animals were inoculated with three recombinant proteins (rNcSAG1, rNcHSP20, rNcGRA7) formulated with ISCOMs; group B animals received ISCOM-MATRIX (without antigen) and group C received sterile phosphate-buffered saline (PBS) only. The recombinant proteins were expressed in Escherichia coli and purified nickel resin. All groups were intravenously challenged with the NC-1 strain of N. caninum at Day 70 of gestation and dams slaughtered at week 17 of the experiment. Heifers from group A developed specific antibodies against rNcSAG1, rNcHSP20 and rNcGRA7 prior to the challenge. Following immunization, an statistically significant increase of antibodies against rNcSAG1 and rNcHSP20 in all animals of group A was detected compared to animals in groups B and C at weeks 5, 13 and 16 (P0.001). There were no differences in IFN-γ production among the experimental groups at any time point (P>0.05). Transplacental transmission was determined in all foetuses of groups A, B and C by Western blot, immunohistochemistry and nested PCR. This work showed that rNcSAG1, rNcHSP20 and rNcGRA7 proteins while immunogenic in cattle failed to prevent the foetal infection in pregnant cattle challenged at Day 70 of gestation. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Challenges in horizontal model integration.

    Science.gov (United States)

    Kolczyk, Katrin; Conradi, Carsten

    2016-03-11

    Systems Biology has motivated dynamic models of important intracellular processes at the pathway level, for example, in signal transduction and cell cycle control. To answer important biomedical questions, however, one has to go beyond the study of isolated pathways towards the joint study of interacting signaling pathways or the joint study of signal transduction and cell cycle control. Thereby the reuse of established models is preferable, as it will generally reduce the modeling effort and increase the acceptance of the combined model in the field. Obtaining a combined model can be challenging, especially if the submodels are large and/or come from different working groups (as is generally the case, when models stored in established repositories are used). To support this task, we describe a semi-automatic workflow based on established software tools. In particular, two frequent challenges are described: identification of the overlap and subsequent (re)parameterization of the integrated model. The reparameterization step is crucial, if the goal is to obtain a model that can reproduce the data explained by the individual models. For demonstration purposes we apply our workflow to integrate two signaling pathways (EGF and NGF) from the BioModels Database.

  11. Intravenous nitroglycerin as an experimental model of vascular headache. Basic characteristics

    DEFF Research Database (Denmark)

    Iversen, Helle Klingenberg; Olesen, J; Tfelt-Hansen, P

    1989-01-01

    To develop a reliable experimental model of vascular headache, we studied the dose-response relationship between headache and i.v. nitroglycerin (NTG) in 10 healthy subjects. NTG was infused intravenously over periods of 10 min separated by wash-out periods. Doses of 0.25, 0.50, 1.00 and 2......) at various doses and declined rapidly after NTG discontinuation. Wash-out periods of 10-20 min were sufficient. The reproducibility of headache intensity and character was satisfactory in the retest experiment. There were no unpleasant side effects and no visible flushing. Thus blindness was maintained. I...

  12. Neuroprotective and behavioral efficacy of intravenous transplanted adipose stem cells in experimental Parkinsonian rat models

    Directory of Open Access Journals (Sweden)

    Malihe Nakhaeifard

    2016-02-01

    Full Text Available Background: Parkinson's disease is a deficiency of dopamine in the striatum, characterized by bradykinesis, rigidity and resting tremor. Adipose tissue-Derived Stem Cells (ADSCs have many advantages for cell therapy because of the easy availability and pluripotency without ethical problems. In this research, the effects of ADSCs transplantation on motor impairment of rat Parkinsonian models were evaluated. Materials and Methods: Parkinson model was constructed by the unilateral lesion of striatum of male Wistar rats using 20µg of 6-hydroxydopamine (6-OHDA as lesion group. Cell and α-MEM (α-minimal essential medium groups were lesioned animals that received intravenous injection of 3×106 cells suspended in medium and medium repectively. All rats were evaluated behaviorally with rotarod and apomorphine-induced rotation tests, at 4 and 8 weeks after cell transplantation. Results: Lesion and α-MEM groups showed increased contralateral turns while cell group significantly ameliorated both in rotarod and apomorphine-induced rotation tests. There was a significant difference of contralateral turns between cell and lesioned groups at 8 weeks after transplantation. Lesioned rats showed significant decrease of staying on the rod as compared to control, but in cell group there was a significant increase in comparision with the lesioned animals. Conclusion: ADSCs injected intravenously promote functional recovery in Parkinsonian rats.

  13. Comparison of the Effectiveness of a Virtual Simulator With a Plastic Arm Model in Teaching Intravenous Catheter Insertion Skills.

    Science.gov (United States)

    Günay İsmailoğlu, Elif; Zaybak, Ayten

    2018-02-01

    The objective of this study was to compare the effectiveness of a virtual intravenous simulator with a plastic arm model in teaching intravenous catheter insertion skills to nursing students. We used a randomized controlled quasi-experimental trial design and recruited 65 students who were assigned to the experimental (n = 33) and control (n = 32) groups using the simple random sampling method. The experimental group received intravenous catheterization skills training on the virtual intravenous simulator, and the control group received the same training on a plastic model of a human arm. Data were collected using the personal information form, intravenous catheterization knowledge assessment form, Intravenous Catheterization Skill Test, Self-Confidence and Satisfaction Scale, and Fear Symptoms Scale. In the study, the mean scores in the control group were 20.44 for psychomotor skills, 15.62 for clinical psychomotor skills, 31.78 for self-confidence, and 21.77 for satisfaction. The mean scores in the experimental group were 45.18 for psychomotor skills, 16.28 for clinical psychomotor skills, 34.18 for self-confidence, and 43.89 for satisfaction. The results indicated that psychomotor skills and satisfaction scores were higher in the experimental group, while the clinical psychomotor skills and self-confidence scores were similar in both groups. More students in the control group reported experiencing symptoms such as cold and sweaty hands, significant restlessness, and tense muscles than those in the experimental group.

  14. Population Pharmacokinetics of Intravenous Paracetamol (Acetaminophen) in Preterm and Term Neonates: Model Development and External Evaluation.

    Science.gov (United States)

    Cook, Sarah F; Roberts, Jessica K; Samiee-Zafarghandy, Samira; Stockmann, Chris; King, Amber D; Deutsch, Nina; Williams, Elaine F; Allegaert, Karel; Wilkins, Diana G; Sherwin, Catherine M T; van den Anker, John N

    2016-01-01

    The aims of this study were to develop a population pharmacokinetic model for intravenous paracetamol in preterm and term neonates and to assess the generalizability of the model by testing its predictive performance in an external dataset. Nonlinear mixed-effects models were constructed from paracetamol concentration-time data in NONMEM 7.2. Potential covariates included body weight, gestational age, postnatal age, postmenstrual age, sex, race, total bilirubin, and estimated glomerular filtration rate. An external dataset was used to test the predictive performance of the model through calculation of bias, precision, and normalized prediction distribution errors. The model-building dataset included 260 observations from 35 neonates with a mean gestational age of 33.6 weeks [standard deviation (SD) 6.6]. Data were well-described by a one-compartment model with first-order elimination. Weight predicted paracetamol clearance and volume of distribution, which were estimated as 0.348 L/h (5.5 % relative standard error; 30.8 % coefficient of variation) and 2.46 L (3.5 % relative standard error; 14.3 % coefficient of variation), respectively, at the mean subject weight of 2.30 kg. An external evaluation was performed on an independent dataset that included 436 observations from 60 neonates with a mean gestational age of 35.6 weeks (SD 4.3). The median prediction error was 10.1 % [95 % confidence interval (CI) 6.1-14.3] and the median absolute prediction error was 25.3 % (95 % CI 23.1-28.1). Weight predicted intravenous paracetamol pharmacokinetics in neonates ranging from extreme preterm to full-term gestational status. External evaluation suggested that these findings should be generalizable to other similar patient populations.

  15. Population pharmacokinetic model of THC integrates oral, intravenous, and pulmonary dosing and characterizes short- and long-term pharmacokinetics.

    Science.gov (United States)

    Heuberger, Jules A A C; Guan, Zheng; Oyetayo, Olubukayo-Opeyemi; Klumpers, Linda; Morrison, Paul D; Beumer, Tim L; van Gerven, Joop M A; Cohen, Adam F; Freijer, Jan

    2015-02-01

    Δ(9)-Tetrahydrocannobinol (THC), the main psychoactive compound of Cannabis, is known to have a long terminal half-life. However, this characteristic is often ignored in pharmacokinetic (PK) studies of THC, which may affect the accuracy of predictions in different pharmacologic areas. For therapeutic use for example, it is important to accurately describe the terminal phase of THC to describe accumulation of the drug. In early clinical research, the THC challenge test can be optimized through more accurate predictions of the dosing sequence and the wash-out between occasions in a crossover setting, which is mainly determined by the terminal half-life of the compound. The purpose of this study is to better quantify the long-term pharmacokinetics of THC. A population-based PK model for THC was developed describing the profile up to 48 h after an oral, intravenous, and pulmonary dose of THC in humans. In contrast to earlier models, the current model integrates all three major administration routes and covers the long terminal phase of THC. Results show that THC has a fast initial and intermediate half-life, while the apparent terminal half-life is long (21.5 h), with a clearance of 38.8 L/h. Because the current model characterizes the long-term pharmacokinetics, it can be used to assess the accumulation of THC in a multiple-dose setting and to forecast concentration profiles of the drug under many different dosing regimens or administration routes. Additionally, this model could provide helpful insights into the THC challenge test used for the development of (novel) compounds targeting the cannabinoid system for different therapeutic applications and could improve decision making in future clinical trials.

  16. Intraosseous Urography Compared with Intravenous Urography: An Experimental Study in the Rabbit Model

    OpenAIRE

    SAĞLAM, Mutlu; UĞUREL, Şahin

    2014-01-01

    This study was performed to evaluate the feasibility of bone injection gun assisted intraosseous administration of contrast media as an alternative to the intravenous route for urography. Intravenous urographies were obtained in 6 rabbits. Urographic examinations by the intraosseous route were performed in the same animals 48 h later. After adequate anesthesia, the retroauricular vein was punctured for intravenous injection and a bone injection gun was used for intraosseous injections to the ...

  17. Oscillatory dynamics of an intravenous glucose tolerance test model with delay interval

    Science.gov (United States)

    Shi, Xiangyun; Kuang, Yang; Makroglou, Athena; Mokshagundam, Sriprakash; Li, Jiaxu

    2017-11-01

    Type 2 diabetes mellitus (T2DM) has become prevalent pandemic disease in view of the modern life style. Both diabetic population and health expenses grow rapidly according to American Diabetes Association. Detecting the potential onset of T2DM is an essential focal point in the research of diabetes mellitus. The intravenous glucose tolerance test (IVGTT) is an effective protocol to determine the insulin sensitivity, glucose effectiveness, and pancreatic β-cell functionality, through the analysis and parameter estimation of a proper differential equation model. Delay differential equations have been used to study the complex physiological phenomena including the glucose and insulin regulations. In this paper, we propose a novel approach to model the time delay in IVGTT modeling. This novel approach uses two parameters to simulate not only both discrete time delay and distributed time delay in the past interval, but also the time delay distributed in a past sub-interval. Normally, larger time delay, either a discrete or a distributed delay, will destabilize the system. However, we find that time delay over a sub-interval might not. We present analytically some basic model properties, which are desirable biologically and mathematically. We show that this relatively simple model provides good fit to fluctuating patient data sets and reveals some intriguing dynamics. Moreover, our numerical simulation results indicate that our model may remove the defect in well known Minimal Model, which often overestimates the glucose effectiveness index.

  18. The 24-Hour Mathematical Modeling Challenge

    Science.gov (United States)

    Galluzzo, Benjamin J.; Wendt, Theodore J.

    2015-01-01

    Across the mathematics curriculum there is a renewed emphasis on applications of mathematics and on mathematical modeling. Providing students with modeling experiences beyond the ordinary classroom setting remains a challenge, however. In this article, we describe the 24-hour Mathematical Modeling Challenge, an extracurricular event that exposes…

  19. Using pharmacokinetic modelling to improve prescribing practices of intravenous aminophylline in childhood asthma exacerbations.

    Science.gov (United States)

    Cooney, Lewis; McBride, Antonia; Lilley, Andrew; Sinha, Ian; Johnson, Trevor N; Hawcutt, Daniel B

    2017-04-01

    To evaluate physiologically based pharmacokinetic modelling (PBPK) software in paediatric asthma patients using intravenous aminophylline. Prospective clinical audit of children receiving iv aminophylline (July 2014 to June 2016), and in-silico modelling using Simcyp software. Thirty-eight admissions (25 children) were included. Children with aminophylline levels ≥10 mg/l had equivalent clinical outcomes compared to those model. PBPK modelling of a 5 mg/kg iv loading dose (≤18yr) shows a mean C max of 8.99 mg/L (5th-95th centiles 5.5-13.7 mg/L), with 70.3% of subjects  20 mg/L. For an aminophylline infusion (0-12 y) of 1.0  mg/kg/h, the mean steady state infusion concentration was 16.4 mg/L, (5th-95th centiles 5.3-32 mg/L), with 26.8% having a serum concentration >20 mg/L. For 12-18yr receiving 0.5  mg/kg/h infusion, the mean steady state infusion concentration was 9.37 mg/L (5th-95th centiles 3.4-18 mg/L), with 59.8% having a serum concentration modelling correlates well with clinical data. Current aminophylline iv loading dosage recommendations achieve levels risk of toxicity (>20 mg/l). Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Data Modeling Challenges of Advanced Interoperability.

    Science.gov (United States)

    Blobel, Bernd; Oemig, Frank; Ruotsalainen, Pekka

    2018-01-01

    Progressive health paradigms, involving many different disciplines and combining multiple policy domains, requires advanced interoperability solutions. This results in special challenges for modeling health systems. The paper discusses classification systems for data models and enterprise business architectures and compares them with the ISO Reference Architecture. On that basis, existing definitions, specifications and standards of data models for interoperability are evaluated and their limitations are discussed. Amendments to correctly use those models and to better meet the aforementioned challenges are offered.

  1. New primate model for the study of intravenous thrombotic potential and its modification

    International Nuclear Information System (INIS)

    Shoenfeld, N.A.; Yeager, A.; Connolly, R.; Ramberg, K.; Forgione, L.; Giorgio, A.; Valeri, C.R.; Callow, A.D.

    1988-01-01

    Advances in venous reconstruction have been limited by inherent venous thrombogenicity and the absence of a suitable prosthetic material for use in the venous system. We have designed an in vivo experimental model to evaluate early blood-material interactions within the venous system and to quantitate drug efficacy in the alteration of platelet function and fibrin deposition in the baboon. An 8F catheter was placed percutaneously in the femoral vein of an adult male baboon. Indium 111-labeled autogenous platelets or iodine 125-labeled human fibrinogen was infused before the introduction, into the inferior vena cava, of a linear array of 5 x 15 mm alternating Dacron and polytetrafluoroethylene samples attached to a benzalkonium-heparin-treated guide wire. At 60 or 120 minutes the samples were removed and a 1 ml aliquot of blood was drawn. The materials and blood samples were counted in a gamma well counter, and the material counts were normalized to the circulating label present in the 1 ml blood sample. The experiment was repeated after pretreatment with heparin, aspirin, or dextran. Whole blood clotting times and bleeding times were monitored. The results showed decreased platelet and fibrin deposition on polytetrafluoroethylene when compared with Dacron in the venous system. Aspirin, heparin, and dextran were all found to decrease platelet and fibrin deposition onto intravenously placed graft material samples (p less than 0.05, Student's t test). The data confirm the ability of the model to evaluate quantitatively anticoagulants, antiplatelet agents, and prospective graft materials for use in venous reconstructions

  2. Overcoming bioanalytical challenges in an Onglyza(®) intravenous [(14)C]microdose absolute bioavailability study with accelerator MS.

    Science.gov (United States)

    Xu, Xiaohui Sophia; Dueker, Stephen R; Christopher, Lisa J; Lohstroh, Pete N; Keung, Chi Fung Anther; Cao, Kai Kevin; Bonacorsi, Samuel J; Cojocaru, Laura; Shen, Jim X; Humphreys, W Griffith; Stouffer, Bruce; Arnold, Mark E

    2012-08-01

    An absolute bioavailability study that utilized an intravenous [(14)C]microdose was conducted for saxagliptin (Onglyza(®)), a marketed drug product for the treatment of Type 2 diabetes mellitus. Concentrations of [(14)C]saxagliptin were determined by accelerator MS (AMS) after protein precipitation, chromatographic separation by UPLC and analyte fraction collection. A series of investigative experiments were conducted to maximize the release of the drug from high-affinity receptors and nonspecific adsorption, and to determine a suitable quantitation range. A technique-appropriate validation demonstrated the accuracy, precision, specificity, stability and recovery of the AMS methodology across the concentration range of 0.025 to 15.0 dpm/ml (disintegration per minute per milliliter), the equivalent of 1.91-1144 pg/ml. Based on the study sample analysis, the mean absolute bioavailability of saxagliptin was 50% in the eight subjects with a CV of 6.6%. Incurred sample reanalysis data fell well within acceptable limits. This study demonstrated that the optimized sample pretreatment and chromatographic separation procedures were critical for the successful implementation of an UPLC plus AMS method for [(14)C]saxagliptin. The use of multiple-point standards are useful, particularly during method development and validation, to evaluate and correct for concentration-dependent recovery, if observed, and to monitor and control process loss and operational variations.

  3. Intravenous contrast media application using cone-beam computed tomography in a rabbit model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Sung; Kim, Bok Yeol; Choi, Hwa Young [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University, Seoul (Korea, Republic of); and others

    2015-03-15

    This study was performed to evaluate the feasibility of visualizing soft tissue lesions and vascular structures using contrast-enhanced cone-beam computed tomography (CE-CBCT) after the intravenous administration of a contrast medium in an animal model. CBCT was performed on six rabbits after a contrast medium was administered using an injection dose of 2 mL/kg body weight and an injection rate of 1 mL/s via the ear vein or femoral vein under general anesthesia. Artificial soft tissue lesions were created through the transplantation of autologous fatty tissue into the salivary gland. Volume rendering reconstruction, maximum intensity projection, and multiplanar reconstruction images were reconstructed and evaluated in order to visualize soft tissue contrast and vascular structures. The contrast enhancement of soft tissue was possible using all contrast medium injection parameters. An adequate contrast medium injection parameter for facilitating effective CE-CBCT was a 5-mL injection before exposure combined with a continuous 5-mL injection during scanning. Artificial soft tissue lesions were successfully created in the animals. The CE-CBCT images demonstrated adequate opacification of the soft tissues and vascular structures. Despite limited soft tissue resolution, the opacification of vascular structures was observed and artificial soft tissue lesions were visualized with sufficient contrast to the surrounding structures. The vascular structures and soft tissue lesions appeared well delineated in the CE-CBCT images, which was probably due to the superior spatial resolution of CE-CBCT compared to other techniques, such as multislice computed tomography.

  4. Intravenous contrast media application using cone-beam computed tomography in a rabbit model

    International Nuclear Information System (INIS)

    Kim, Min Sung; Kim, Bok Yeol; Choi, Hwa Young

    2015-01-01

    This study was performed to evaluate the feasibility of visualizing soft tissue lesions and vascular structures using contrast-enhanced cone-beam computed tomography (CE-CBCT) after the intravenous administration of a contrast medium in an animal model. CBCT was performed on six rabbits after a contrast medium was administered using an injection dose of 2 mL/kg body weight and an injection rate of 1 mL/s via the ear vein or femoral vein under general anesthesia. Artificial soft tissue lesions were created through the transplantation of autologous fatty tissue into the salivary gland. Volume rendering reconstruction, maximum intensity projection, and multiplanar reconstruction images were reconstructed and evaluated in order to visualize soft tissue contrast and vascular structures. The contrast enhancement of soft tissue was possible using all contrast medium injection parameters. An adequate contrast medium injection parameter for facilitating effective CE-CBCT was a 5-mL injection before exposure combined with a continuous 5-mL injection during scanning. Artificial soft tissue lesions were successfully created in the animals. The CE-CBCT images demonstrated adequate opacification of the soft tissues and vascular structures. Despite limited soft tissue resolution, the opacification of vascular structures was observed and artificial soft tissue lesions were visualized with sufficient contrast to the surrounding structures. The vascular structures and soft tissue lesions appeared well delineated in the CE-CBCT images, which was probably due to the superior spatial resolution of CE-CBCT compared to other techniques, such as multislice computed tomography.

  5. Comparative kinetics of serum and vitreous humor digoxin concentrations in a guinea pig model. Part I: Intravenous administration of digoxin

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, B.; Balkon, J.; Bidanset, J.H.; Belmonte, A.; Barletta, M.; Manning, T. (Department of Pharmaceutical Sciences, College of Pharmacy and Allied Health Professions, St. John' s University, Jamaica, NY (USA))

    1991-03-01

    The pharmacokinetics of a single intravenous dose of digoxin in the guinea pig was investigated with emphasis on the penetration of digoxin into the vitreous humor. A controlled study was undertaken and data was collected which indicated that digoxin follows an open, two-compartment pharmacokinetic model with a terminal half-life of 318 minutes. The data indicated that the ratio of vitreous concentrations to serum concentrations were determined to be equal following an initial tissue distribution phase.

  6. A new mouse model for renal lesions produced by intravenous injection of diphtheria toxin A-chain expression plasmid

    Directory of Open Access Journals (Sweden)

    Nakamura Shingo

    2004-04-01

    Full Text Available Abstract Background Various animal models of renal failure have been produced and used to investigate mechanisms underlying renal disease and develop therapeutic drugs. Most methods available to produce such models appear to involve subtotal nephrectomy or intravenous administration of antibodies raised against basement membrane of glomeruli. In this study, we developed a novel method to produce mouse models of renal failure by intravenous injection of a plasmid carrying a toxic gene such as diphtheria toxin A-chain (DT-A gene. DT-A is known to kill cells by inhibiting protein synthesis. Methods An expression plasmid carrying the cytomegalovirus enhancer/chicken β-actin promoter linked to a DT-A gene was mixed with lipid (FuGENE™6 and the resulting complexes were intravenously injected into adult male B6C3F1 mice every day for up to 6 days. After final injection, the kidneys of these mice were sampled on day 4 and weeks 3 and 5. Results H-E staining of the kidney specimens sampled on day 4 revealed remarkable alterations in glomerular compartments, as exemplified by mesangial cell proliferation and formation of extensive deposits in glomerular basement membrane. At weeks 3 and 5, gradual recovery of these tissues was observed. These mice exhibited proteinuria and disease resembling sub-acute glomerulonephritis. Conclusions Repeated intravenous injections of DT-A expression plasmid DNA/lipid complex caused temporary abnormalities mainly in glomeruli of mouse kidney. The disease in these mice resembles sub-acute glomerulonephritis. These DT-A gene-incorporated mice will be useful as animal models in the fields of nephrology and regenerative medicine.

  7. Comparative kinetics of serum and vitreous humor digoxin concentrations in a guinea pig model. Part I: Intravenous administration of digoxin

    International Nuclear Information System (INIS)

    Donnelly, B.; Balkon, J.; Bidanset, J.H.; Belmonte, A.; Barletta, M.; Manning, T.

    1991-01-01

    The pharmacokinetics of a single intravenous dose of digoxin in the guinea pig was investigated with emphasis on the penetration of digoxin into the vitreous humor. A controlled study was undertaken and data was collected which indicated that digoxin follows an open, two-compartment pharmacokinetic model with a terminal half-life of 318 minutes. The data indicated that the ratio of vitreous concentrations to serum concentrations were determined to be equal following an initial tissue distribution phase

  8. Synchrotron-based intra-venous K-edge digital subtraction angiography in a pig model: A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Schueltke, Elisabeth [Departments of Surgery, University of Saskatchewan, Saskatoon, SK (Canada); Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK (Canada); Department of Neurological Sciences, Walton Medical Centre, University of Liverpool, Liverpool L97 LJ (United Kingdom)], E-mail: e.schultke@usask.ca; Fiedler, Stefan [European Molecular Biology Laboratory (EMBL), Nottkestrasse 85, 22603 Hamburg (Germany); Nemoz, Christian [European Synchrotron Radiation Facility (ESRF), 6 rue Horowitz, 38043 Grenoble (France); Ogieglo, Lissa [Departments of Surgery, University of Saskatchewan, Saskatoon, SK (Canada); Kelly, Michael E. [Departments of Surgery, University of Saskatchewan, Saskatoon, SK (Canada); Department of Neurosurgery, Section of Cerebrovascular and Endovascular Neurosurgery, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH (United States); Crawford, Paul [Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herfordshire AL9 7TA (United Kingdom); Esteve, Francois [INSERM U836-ESRF, 6 rue Horowitz, 38043 Grenoble (France); Brochard, Thierry; Renier, Michel; Requardt, Herwig; Le Duc, Geraldine [European Synchrotron Radiation Facility (ESRF), 6 rue Horowitz, 38043 Grenoble (France); Juurlink, Bernhard [Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK (Canada); Meguro, Kotoo [Departments of Surgery, University of Saskatchewan, Saskatoon, SK (Canada)

    2010-03-15

    Background: K-edge digital subtraction angiography (KEDSA) combined with the tunability of synchrotron beam yields an imaging technique that is highly sensitive to low concentrations of contrast agents. Thus, contrast agent can be administered intravenously, obviating the need for insertion of a guided catheter to deliver a bolus of contrast agent close to the target tissue. With the high-resolution detectors used at synchrotron facilities, images can be acquired at high spatial resolution. Thus, the KEDSA appears particularly suited for studies of neurovascular pathology in animal models, where the vascular diameters are significantly smaller than in human patients. Materials and methods: This feasibility study was designed to test the suitability of KEDSA after intravenous injection of iodine-based contrast agent for use in a pig model. Four adult male pigs were used for our experiments. Neurovascular angiographic images were acquired using KEDSA with a solid state Germanium (Ge) detector at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. Results: After intravenous injection of 0.9 ml/kg iodinated contrast agent (Xenetix), the peak iodine concentrations in the internal carotid and middle cerebral arteries reached 35 mg/ml. KEDSA images in radiography mode allowed the visualization of intracranial arteries of less than 1.5 mm diameter.

  9. Synchrotron-based intra-venous K-edge digital subtraction angiography in a pig model: A feasibility study

    International Nuclear Information System (INIS)

    Schueltke, Elisabeth; Fiedler, Stefan; Nemoz, Christian; Ogieglo, Lissa; Kelly, Michael E.; Crawford, Paul; Esteve, Francois; Brochard, Thierry; Renier, Michel; Requardt, Herwig; Le Duc, Geraldine; Juurlink, Bernhard; Meguro, Kotoo

    2010-01-01

    Background: K-edge digital subtraction angiography (KEDSA) combined with the tunability of synchrotron beam yields an imaging technique that is highly sensitive to low concentrations of contrast agents. Thus, contrast agent can be administered intravenously, obviating the need for insertion of a guided catheter to deliver a bolus of contrast agent close to the target tissue. With the high-resolution detectors used at synchrotron facilities, images can be acquired at high spatial resolution. Thus, the KEDSA appears particularly suited for studies of neurovascular pathology in animal models, where the vascular diameters are significantly smaller than in human patients. Materials and methods: This feasibility study was designed to test the suitability of KEDSA after intravenous injection of iodine-based contrast agent for use in a pig model. Four adult male pigs were used for our experiments. Neurovascular angiographic images were acquired using KEDSA with a solid state Germanium (Ge) detector at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. Results: After intravenous injection of 0.9 ml/kg iodinated contrast agent (Xenetix), the peak iodine concentrations in the internal carotid and middle cerebral arteries reached 35 mg/ml. KEDSA images in radiography mode allowed the visualization of intracranial arteries of less than 1.5 mm diameter.

  10. Synchrotron-based intra-venous K-edge digital subtraction angiography in a pig model: a feasibility study.

    Science.gov (United States)

    Schültke, Elisabeth; Fiedler, Stefan; Nemoz, Christian; Ogieglo, Lissa; Kelly, Michael E; Crawford, Paul; Esteve, Francois; Brochard, Thierry; Renier, Michel; Requardt, Herwig; Le Duc, Geraldine; Juurlink, Bernhard; Meguro, Kotoo

    2010-03-01

    K-edge digital subtraction angiography (KEDSA) combined with the tunability of synchrotron beam yields an imaging technique that is highly sensitive to low concentrations of contrast agents. Thus, contrast agent can be administered intravenously, obviating the need for insertion of a guided catheter to deliver a bolus of contrast agent close to the target tissue. With the high-resolution detectors used at synchrotron facilities, images can be acquired at high spatial resolution. Thus, the KEDSA appears particularly suited for studies of neurovascular pathology in animal models, where the vascular diameters are significantly smaller than in human patients. This feasibility study was designed to test the suitability of KEDSA after intravenous injection of iodine-based contrast agent for use in a pig model. Four adult male pigs were used for our experiments. Neurovascular angiographic images were acquired using KEDSA with a solid state Germanium (Ge) detector at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. After intravenous injection of 0.9 ml/kg iodinated contrast agent (Xenetix), the peak iodine concentrations in the internal carotid and middle cerebral arteries reached 35 mg/ml. KEDSA images in radiography mode allowed the visualization of intracranial arteries of less than 1.5mm diameter. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  11. Five challenges in modelling interacting strain dynamics

    DEFF Research Database (Denmark)

    Wikramaratna, Paul S; Kurcharski, Adam; Gupta, Sunetra

    2015-01-01

    population models. Next we consider the nature of so-called “strain space”. We describe two key types of host heterogeneities, and explain how models could help generate a better understanding of their effects. Finally, for diseases with many strains, we consider the challenge of modelling how immunity...

  12. Five challenges in modelling interacting strain dynamics

    Directory of Open Access Journals (Sweden)

    Paul S. Wikramaratna

    2015-03-01

    Full Text Available Population epidemiological models where hosts can be infected sequentially by different strains have the potential to help us understand many important diseases. Researchers have in recent years started to develop and use such models, but the extra layer of complexity from multiple strains brings with it many technical challenges. It is therefore hard to build models which have realistic assumptions yet are tractable. Here we outline some of the main challenges in this area. First we begin with the fundamental question of how to translate from complex small-scale dynamics within a host to useful population models. Next we consider the nature of so-called “strain space”. We describe two key types of host heterogeneities, and explain how models could help generate a better understanding of their effects. Finally, for diseases with many strains, we consider the challenge of modelling how immunity accumulates over multiple exposures.

  13. Effects of Intraosseous Tibial vs. Intravenous Vasopressin in a Hypovolemic Cardiac Arrest Model

    Directory of Open Access Journals (Sweden)

    Justin Fulkerson, MSN

    2016-03-01

    Full Text Available Introduction: This study compared the effects of vasopressin via tibial intraosseous (IO and intravenous (IV routes on maximum plasma concentration (Cmax, the time to maximum concentration (Tmax, return of spontaneous circulation (ROSC, and time to ROSC in a hypovolemic cardiac arrest model. Methods: This study was a randomized prospective, between-subjects experimental design. A computer program randomly assigned 28 Yorkshire swine to one of four groups: IV (n=7, IO tibia (n=7, cardiopulmonary resuscitation (CPR + defibrillation (n=7, and a control group that received just CPR (n=7. Ventricular fibrillation was induced, and subjects remained in arrest for two minutes. CPR was initiated and 40 units of vasopressin were administered via IO or IV routes. Blood samples were collected at 0.5, 1, 1.5, 2, 2.5, 3, and 4 minutes. CPR and defibrillation were initiated for 20 minutes or until ROSC was achieved. We measured vasopressin concentrations using highperformance liquid chromatography. Results: There was no significant difference between the IO and IV groups relative to achieving ROSC (p=1.0 but a significant difference between the IV compared to the CPR+ defibrillation group (p=0.031 and IV compared to the CPR-only group (p=0.001. There was a significant difference between the IO group compared to the CPR+ defibrillation group (p=0.031 and IO compared to the CPR-only group (p=0.001. There was no significant difference between the CPR + defibrillation group and the CPR group (p=0.127. There was no significant difference in Cmax between the IO and IV groups (p=0.079. The mean ± standard deviation of Cmax of the IO group was 58,709±25,463pg/mL compared to the IV group, which was 106,198±62,135pg/mL. There was no significant difference in mean Tmax between the groups (p=0.084. There were no significant differences in odds of ROSC between the tibial IO and IV groups. Conclusion: Prompt access to the vascular system using the IO route can circumvent

  14. Pharmacokinetic modelling of intravenous tobramycin in adolescent and adult patients with cystic fibrosis using the nonparametric expectation maximization (NPEM) algorithm.

    Science.gov (United States)

    Touw, D J; Vinks, A A; Neef, C

    1997-06-01

    The availability of personal computer programs for individualizing drug dosage regimens has stimulated the interest in modelling population pharmacokinetics. Data from 82 adolescent and adult patients with cystic fibrosis (CF) who were treated with intravenous tobramycin because of an exacerbation of their pulmonary infection were analysed with a non-parametric expectation maximization (NPEM) algorithm. This algorithm estimates the entire discrete joint probability density of the pharmacokinetic parameters. It also provides traditional parametric statistics such as the means, standard deviation, median, covariances and correlations among the various parameters. It also provides graphic-2- and 3-dimensional representations of the marginal densities of the parameters investigated. Several models for intravenous tobramycin in adolescent and adult patients with CF were compared. Covariates were total body weight (for the volume of distribution) and creatinine clearance (for the total body clearance and elimination rate). Because of lack of data on patients with poor renal function, restricted models with non-renal clearance and the non-renal elimination rate constant fixed at literature values of 0.15 L/h and 0.01 h-1 were also included. In this population, intravenous tobramycin could be best described by median (+/-dispersion factor) volume of distribution per unit of total body weight of 0.28 +/- 0.05 L/kg, elimination rate constant of 0.25 +/- 0.10 h-1 and elimination rate constant per unit of creatinine clearance of 0.0008 +/- 0.0009 h-1/(ml/min/1.73 m2). Analysis of populations of increasing size showed that using a restricted model with a non-renal elimination rate constant fixed at 0.01 h-1, a model based on a population of only 10 to 20 patients, contained parameter values similar to those of the entire population and, using the full model, a larger population (at least 40 patients) was needed.

  15. Computer Aided Modelling – Opportunities and Challenges

    DEFF Research Database (Denmark)

    Cameron, Ian; Gani, Rafiqul

    2011-01-01

    -based solutions to significant problems? The important issues of workflow and data flow are discussed together with fit-for-purpose model development. As well, the lack of tools around multiscale modelling provides opportunities for the development of efficient tools to address such challenges. The ability...

  16. A Model for the Application of Target-Controlled Intravenous Infusion for a Prolonged Immersive DMT Psychedelic Experience

    Directory of Open Access Journals (Sweden)

    Andrew Robert Gallimore

    2016-07-01

    Full Text Available The state of consciousness induced by N,N-dimethyltryptamine (DMT is one of the most extraordinary of any naturally-occurring psychedelic substance. Users consistently report the complete replacement of normal subjective experience with a novel alternate universe, often densely populated with a variety of strange objects and other highly complex visual content, including what appear to be sentient beings. The phenomenology of the DMT state is of great interest to psychology and calls for rigorous academic enquiry. The extremely short duration of DMT effects—less than 20 minutes—militates against single dose administration as the ideal model for such enquiry. Using pharmacokinetic modelling and DMT blood sampling data, we demonstrate that the unique pharmacological characteristics of DMT, which also include a rapid onset and lack of acute tolerance to its subjective effects, make it amenable to administration by target-controlled intravenous infusion. This is a technology developed to maintain a stable brain concentration of anaesthetic drugs during surgery. Simulations of our model demonstrate that this approach will allow research subjects to be induced into a stable and prolonged DMT experience, making it possible to carefully observe its psychological contents, and provide more extensive accounts for subsequent analyses. This model would also be valuable in performing functional neuroimaging, where subjects are required to remain under the influence of the drug for extended periods. Finally, target-controlled intravenous infusion of DMT may aid the development of unique psychotherapeutic applications of this psychedelic agent.

  17. MRI Based Localisation and Quantification of Abscesses following Experimental S. aureus Intravenous Challenge: Application to Vaccine Evaluation.

    Directory of Open Access Journals (Sweden)

    Elizabeth R Allen

    Full Text Available To develop and validate a sensitive and specific method of abscess enumeration and quantification in a preclinical model of Staphylococcus aureus infection.S. aureus infected murine kidneys were fixed in paraformaldehyde, impregnated with gadolinium, and embedded in agar blocks, which were subjected to 3D magnetic resonance microscopy on a 9.4T MRI scanner. Image analysis techniques were developed, which could identify and quantify abscesses. The result of this imaging was compared with histological examination. The impact of a S. aureus Sortase A vaccination regime was assessed using the technique.Up to 32 murine kidneys could be imaged in a single MRI run, yielding images with voxels of about 25 μm3. S. aureus abscesses could be readily identified in blinded analyses of the kidneys after 3 days of infection, with low inter-observer variability. Comparison with histological sections shows a striking correlation between the two techniques: all presumptive abscesses identified by MRI were confirmed histologically, and histology identified no abscesses not evident on MRI. In view of this, simulations were performed assuming that both MRI reconstruction, and histology examining all sections of the tissue, were fully sensitive and specific at abscess detection. This simulation showed that MRI provided more sensitive and precise estimates of abscess numbers and volume than histology, unless at least 5 histological sections are taken through the long axis of the kidney. We used the MRI technique described to investigate the impact of a S. aureus Sortase A vaccine.Post mortem MRI scanning of large batches of fixed organs has application in the preclinical assessment of S. aureus vaccines.

  18. Big data business models: Challenges and opportunities

    Directory of Open Access Journals (Sweden)

    Ralph Schroeder

    2016-12-01

    Full Text Available This paper, based on 28 interviews from a range of business leaders and practitioners, examines the current state of big data use in business, as well as the main opportunities and challenges presented by big data. It begins with an account of the current landscape and what is meant by big data. Next, it draws distinctions between the ways organisations use data and provides a taxonomy of big data business models. We observe a variety of different business models, depending not only on sector, but also on whether the main advantages derive from analytics capabilities or from having ready access to valuable data sources. Some major challenges emerge from this account, including data quality and protectiveness about sharing data. The conclusion discusses these challenges, and points to the tensions and differing perceptions about how data should be governed as between business practitioners, the promoters of open data, and the wider public.

  19. Computational challenges in modeling gene regulatory events.

    Science.gov (United States)

    Pataskar, Abhijeet; Tiwari, Vijay K

    2016-10-19

    Cellular transcriptional programs driven by genetic and epigenetic mechanisms could be better understood by integrating "omics" data and subsequently modeling the gene-regulatory events. Toward this end, computational biology should keep pace with evolving experimental procedures and data availability. This article gives an exemplified account of the current computational challenges in molecular biology.

  20. Eight challenges for network epidemic models

    Directory of Open Access Journals (Sweden)

    Lorenzo Pellis

    2015-03-01

    Full Text Available Networks offer a fertile framework for studying the spread of infection in human and animal populations. However, owing to the inherent high-dimensionality of networks themselves, modelling transmission through networks is mathematically and computationally challenging. Even the simplest network epidemic models present unanswered questions. Attempts to improve the practical usefulness of network models by including realistic features of contact networks and of host–pathogen biology (e.g. waning immunity have made some progress, but robust analytical results remain scarce. A more general theory is needed to understand the impact of network structure on the dynamics and control of infection. Here we identify a set of challenges that provide scope for active research in the field of network epidemic models.

  1. Challenges in modelling nanoparticles for drug delivery

    International Nuclear Information System (INIS)

    Barnard, Amanda S

    2016-01-01

    Although there have been significant advances in the fields of theoretical condensed matter and computational physics, when confronted with the complexity and diversity of nanoparticles available in conventional laboratories a number of modeling challenges remain. These challenges are generally shared among application domains, but the impacts of the limitations and approximations we make to overcome them (or circumvent them) can be more significant one area than another. In the case of nanoparticles for drug delivery applications some immediate challenges include the incompatibility of length-scales, our ability to model weak interactions and solvation, the complexity of the thermochemical environment surrounding the nanoparticles, and the role of polydispersivity in determining properties and performance. Some of these challenges can be met with existing technologies, others with emerging technologies including the data-driven sciences; some others require new methods to be developed. In this article we will briefly review some simple methods and techniques that can be applied to these (and other) challenges, and demonstrate some results using nanodiamond-based drug delivery platforms as an exemplar. (topical review)

  2. Intravenous cobinamide versus hydroxocobalamin for acute treatment of severe cyanide poisoning in a swine (Sus scrofa) model.

    Science.gov (United States)

    Bebarta, Vikhyat S; Tanen, David A; Boudreau, Susan; Castaneda, Maria; Zarzabal, Lee A; Vargas, Toni; Boss, Gerry R

    2014-12-01

    Hydroxocobalamin is a Food and Drug Administration-approved antidote for cyanide poisoning. Cobinamide is a potential antidote that contains 2 cyanide-binding sites. To our knowledge, no study has directly compared hydroxocobalamin with cobinamide in a severe, cyanide-toxic large-animal model. Our objective is to compare the time to return of spontaneous breathing in swine with acute cyanide-induced apnea treated with intravenous hydroxocobalamin, intravenous cobinamide, or saline solution (control). Thirty-three swine (45 to 55 kg) were intubated, anesthetized, and instrumented (continuous mean arterial pressure and cardiac output monitoring). Anesthesia was adjusted to allow spontaneous breathing with FiO2 of 21% during the experiment. Cyanide was continuously infused intravenously until apnea occurred and lasted for 1 minute (time zero). Animals were then randomly assigned to receive intravenous hydroxocobalamin (65 mg/kg), cobinamide (12.5 mg/kg), or saline solution and monitored for 60 minutes. A sample size of 11 animals per group was selected according to obtaining a power of 80%, an α of .05, and an SD of 0.17 in mean time to detect a 20% difference in time to spontaneous breathing. We assessed differences in time to death among groups, using Kaplan-Meier estimation methods, and compared serum lactate, blood pH, cardiac output, mean arterial pressure, respiratory rate, and minute ventilation time curves with repeated-measures ANOVA. Baseline weights and vital signs were similar among groups. The time to apnea and cyanide dose required to achieve apnea were similar. At time zero, mean cyanide blood and lactate concentrations and reduction in mean arterial pressure from baseline were similar. In the saline solution group, 2 of 11 animals survived compared with 10 of 11 in the hydroxocobalamin and cobinamide groups (Pcyanide concentrations became undetectable at the end of the study in both antidote-treated groups, and no statistically significant differences

  3. Challenges in Continuum Modelling of Intergranular Fracture

    DEFF Research Database (Denmark)

    Coffman, Valerie; Sethna, James P.; Ingraffea, A. R.

    2011-01-01

    of grain boundaries, but also in crucial ways on edges, corners and triple junctions of even greater geometrical complexity. To address the first two challenges, we explore the physical underpinnings for creating functional forms to capture the hierarchical commensurability structure in the grain boundary......Intergranular fracture in polycrystals is often simulated by finite elements coupled to a cohesive zone model for the interfaces, requiring cohesive laws for grain boundaries as a function of their geometry. We discuss three challenges in understanding intergranular fracture in polycrystals. First...... properties. To address the last challenge, we demonstrate a method for atomistically extracting the fracture properties of geometrically complex local regions on the fly from within a finite element simulation....

  4. Intravenous Glutamine Administration Modulates TNF-α/IL-10 Ratio and Attenuates NFkB Phosphorylation in a Protein Malnutrition Model.

    Science.gov (United States)

    Santos, Andressa Cristina Antunes; Correia, Carolina Argondizo; de Oliveira, Dalila Cunha; Nogueira-Pedro, Amanda; Borelli, Primavera; Fock, Ricardo Ambrosio

    2016-12-01

    Protein malnutrition (PM) is a major public health problem in developing countries, affecting the inflammatory response and increasing susceptibility to opportunistic infections. For this reason, an adequate nutritional intervention can improve the quality of life of patients. Glutamine (GLN) is a nonessential amino acid, but can be considered "conditionally essential" for macrophage function in stress situations, in which it plays a role in the improvement of the inflammatory response. Concerning this issue, in the current study, it was of interest to evaluate some biological aspects of peritoneal cells from a protein malnutrition (PM) mouse model challenged with lipopolysaccharide (LPS) and treated intravenously with GLN. Two-month-old male Balb/c mice were subjected to a low-protein diet (2 % protein) and stimulated intravenously with LPS 1 h prior to the injection of 0.75 mg/kg GLN. Malnourished animals showed a reduced number of total peritoneal cells. Malnourished animals stimulated with LPS or LPS plus GLN did not show differences in peritoneal cell counts; however, the control group showed increased cellularity after LPS stimulus, which was reversed after GLN injection. Further, in the animals from both groups stimulated with LPS, GLN decreased the circulating levels of TNF-α and the levels of TNF-α produced by peritoneal cells; additionally, GLN decreased the IL-10 circulating levels in the malnourished animals stimulated with LPS. In addition, peritoneal cells of the control and malnourished groups stimulated with LPS showed a negative modulation of the NFkB signaling pathway after GLN injection. In conclusion, this study shows that GLN has the capacity to reduce TNF-α synthesis as well as to act as a negative regulator of NFkB phosphorylation, leading to a positive outcome in the control of TNF-α production.

  5. Seven challenges in modeling vaccine preventable diseases

    Directory of Open Access Journals (Sweden)

    C.J.E. Metcalf

    2015-03-01

    Full Text Available Vaccination has been one of the most successful public health measures since the introduction of basic sanitation. Substantial mortality and morbidity reductions have been achieved via vaccination against many infections, and the list of diseases that are potentially controllable by vaccines is growing steadily. We introduce key challenges for modeling in shaping our understanding and guiding policy decisions related to vaccine preventable diseases.

  6. Intravenous and intratracheal mesenchymal stromal cell injection in a mouse model of pulmonary emphysema.

    Science.gov (United States)

    Tibboel, Jeroen; Keijzer, Richard; Reiss, Irwin; de Jongste, Johan C; Post, Martin

    2014-06-01

    The aim of this study was to characterize the evolution of lung function and -structure in elastase-induced emphysema in adult mice and the effect of mesenchymal stromal cell (MSC) administration on these parameters. Adult mice were treated with intratracheal (4.8 units/100 g bodyweight) elastase to induce emphysema. MSCs were administered intratracheally or intravenously, before or after elastase injection. Lung function measurements, histological and morphometric analysis of lung tissue were performed at 3 weeks, 5 and 10 months after elastase and at 19, 20 and 21 days following MSC administration. Elastase-treated mice showed increased dynamic compliance and total lung capacity, and reduced tissue-specific elastance and forced expiratory flows at 3 weeks after elastase, which persisted during 10 months follow-up. Histology showed heterogeneous alveolar destruction which also persisted during long-term follow-up. Jugular vein injection of MSCs before elastase inhibited deterioration of lung function but had no effects on histology. Intratracheal MSC treatment did not modify lung function or histology. In conclusion, elastase-treated mice displayed persistent characteristics of pulmonary emphysema. Jugular vein injection of MSCs prior to elastase reduced deterioration of lung function. Intratracheal MSC treatment had no effect on lung function or histology.

  7. Intravenous S-Ketamine Does Not Inhibit Alveolar Fluid Clearance in a Septic Rat Model

    Science.gov (United States)

    Weber, Nina C.; van der Sluijs, Koen; Hackl, Florian; Hotz, Lorenz; Dahan, Albert; Hollmann, Markus W.; Berger, Marc M.

    2014-01-01

    We previously demonstrated that intratracheally administered S-ketamine inhibits alveolar fluid clearance (AFC), whereas an intravenous (IV) bolus injection had no effect. The aim of the present study was to characterize whether continuous IV infusion of S-ketamine, yielding clinically relevant plasma concentrations, inhibits AFC and whether its effect is enhanced in acute lung injury (ALI) which might favor the appearance of IV S-ketamine at the alveolar surface. AFC was measured in fluid-instilled rat lungs. S-ketamine was administered IV over 6 h (loading dose: 20 mg/kg, followed by 20 mg/kg/h), or intratracheally by addition to the instillate (75 µg/ml). ALI was induced by IV lipopolysaccharide (LPS; 7 mg/kg). Interleukin (IL)-6 and cytokine-induced neutrophil chemoattractant (CINC)-3 were measured by ELISA in plasma and bronchoalveolar lavage fluid. Isolated rat alveolar type-II cells were exposed to S-ketamine (75 µg/ml) and/or LPS (1 mg/ml) for 6 h, and transepithelial ion transport was measured as short circuit current (ISC). AFC was 27±5% (mean±SD) over 60 min in control rats and was unaffected by IV S-ketamine. Tracheal S-ketamine reduced AFC to 18±9%. In LPS-treated rats, AFC decreased to 16±6%. This effect was not enhanced by IV S-ketamine. LPS increased IL-6 and CINC-3 in plasma and bronchoalveolar lavage fluid. In alveolar type-II cells, S-ketamine reduced ISC by 37% via a decrease in amiloride-inhibitable sodium transport. Continuous administration of IV S-ketamine does not affect rat AFC even in endotoxin-induced ALI. Tracheal application with direct exposure of alveolar epithelial cells to S-ketamine decreases AFC by inhibition of amiloride-inhibitable sodium transport. PMID:25386677

  8. Aeronautical telecommunications network advances, challenges, and modeling

    CERN Document Server

    Musa, Sarhan M

    2015-01-01

    Addresses the Challenges of Modern-Day Air Traffic Air traffic control (ATC) directs aircraft in the sky and on the ground to safety, while the Aeronautical Telecommunications Network (ATN) comprises all systems and phases that assist in aircraft departure and landing. The Aeronautical Telecommunications Network: Advances, Challenges, and Modeling focuses on the development of ATN and examines the role of the various systems that link aircraft with the ground. The book places special emphasis on ATC-introducing the modern ATC system from the perspective of the user and the developer-and provides a thorough understanding of the operating mechanism of the ATC system. It discusses the evolution of ATC, explaining its structure and how it works; includes design examples; and describes all subsystems of the ATC system. In addition, the book covers relevant tools, techniques, protocols, and architectures in ATN, including MIPv6, air traffic control (ATC), security of air traffic management (ATM), very-high-frequenc...

  9. Acute and chronic effects of a 24-hour intravenous triglyceride emulsion challenge on plasma lecithin : cholesterol acyltransferase, phospholipid transfer protein, and cholesteryl ester transfer protein activities

    NARCIS (Netherlands)

    Riemens, SC; Van Tol, A; Sluiter, WJ; Dullaart, RPF

    Lecithin:cholesterol acyltransferase (LCAT), phospholipid transfer protein (PLTP), and cholesteryl ester transfer protein (CETP) are key factors in remodeling of high density lipoproteins (HDL) and triglyceride-rich lipoproteins. We examined the effect of a large, 24 h intravenous fat load on plasma

  10. Eight challenges in modelling infectious livestock diseases

    Directory of Open Access Journals (Sweden)

    E. Brooks-Pollock

    2015-03-01

    Full Text Available The transmission of infectious diseases of livestock does not differ in principle from disease transmission in any other animals, apart from that the aim of control is ultimately economic, with the influence of social, political and welfare constraints often poorly defined. Modelling of livestock diseases suffers simultaneously from a wealth and a lack of data. On the one hand, the ability to conduct transmission experiments, detailed within-host studies and track individual animals between geocoded locations make livestock diseases a particularly rich potential source of realistic data for illuminating biological mechanisms of transmission and conducting explicit analyses of contact networks. On the other hand, scarcity of funding, as compared to human diseases, often results in incomplete and partial data for many livestock diseases and regions of the world. In this overview of challenges in livestock disease modelling, we highlight eight areas unique to livestock that, if addressed, would mark major progress in the area.

  11. Vasoactive side effects of intravenous immunoglobulin preparations in a rat model and their treatment with recombinant platelet-activating factor acetylhydrolase

    NARCIS (Netherlands)

    Bleeker, W. K.; Teeling, J. L.; Verhoeven, A. J.; Rigter, G. M.; Agterberg, J.; Tool, A. T.; Koenderman, A. H.; Kuijpers, T. W.; Hack, C. E.

    2000-01-01

    Previously, we observed in a rat model that intravenous administration of intramuscular immunoglobulin preparations induced a long-lasting hypotension, which appeared to be associated with the presence of IgG polymers and dimers in the preparations, but unrelated to complement activation. We found

  12. Dosimetry of intravenously administered oxygen-15 labelled water in man: a model based on experimental human data from 21 subjects

    International Nuclear Information System (INIS)

    Smith, T.; Tong, C.; Lammertsma, A.A.; Butler, K.R.; Schnorr, L.; Watson, J.D.G.; Ramsay, S.; Clark, J.C.; Jones, T.

    1994-01-01

    Models based on uniform distribution of tracer in total body water underestimate the absorbed dose from H 2 15 O because of the short half-life (2.04 min) of 15 O, which leads to non-uniform distribution of absorbed dose and also complicates the direct measurement of organ retention curves. However, organ absorbed doses can be predicted by the present kinetic model based on the convolution technique. The measured time course of arterial H 2 15 O concentration following intravenous administration represents the input function to organs. The impulse response of a given organ is its transit time function determined by blood flow and the partition of water between tissue and blood. Values of these two parameters were taken from the literature. Integrals of the arterial input function and organ transit time functions were used to derive integrals of organ retention functions (organ residence times). The latter were used with absorbed dose calculation software (MIRDOSE-2) to obtain estimates for 24 organs. From the mean values of organ absorbed doses, the effective dose equivalent (EDE) and effective dose (ED) were calculated. From measurements on 21 subjects, the average value for both EDE and ED was calculated to be 1.2 μSv.MBq -1 compared with a value of about 0.5 μSv.MBq -1 predicted by uniform water distribution models. Based on the human data, a method of approximating H 2 15 O absorbed dose values from body surface area is described. (orig.)

  13. Collaborative Inquiry Learning: Models, tools, and challenges

    Science.gov (United States)

    Bell, Thorsten; Urhahne, Detlef; Schanze, Sascha; Ploetzner, Rolf

    2010-02-01

    Collaborative inquiry learning is one of the most challenging and exciting ventures for today's schools. It aims at bringing a new and promising culture of teaching and learning into the classroom where students in groups engage in self-regulated learning activities supported by the teacher. It is expected that this way of learning fosters students' motivation and interest in science, that they learn to perform steps of inquiry similar to scientists and that they gain knowledge on scientific processes. Starting from general pedagogical reflections and science standards, the article reviews some prominent models of inquiry learning. This comparison results in a set of inquiry processes being the basis for cooperation in the scientific network NetCoIL. Inquiry learning is conceived in several ways with emphasis on different processes. For an illustration of the spectrum, some main conceptions of inquiry and their focuses are described. In the next step, the article describes exemplary computer tools and environments from within and outside the NetCoIL network that were designed to support processes of collaborative inquiry learning. These tools are analysed by describing their functionalities as well as effects on student learning known from the literature. The article closes with challenges for further developments elaborated by the NetCoIL network.

  14. Modeling for Ecosystem Services: Challenges and Opportunities

    Science.gov (United States)

    Guswa, A. J.; Brauman, K. A.; Ghile, Y.

    2012-12-01

    Ecosystem services are those values provided to human society by the structure and processes of ecosystems and landscapes. Water-related services include the transformation of precipitation impulses into supplies of water for hydropower, irrigation, and industrial and municipal uses, the retention and removal of applied nutrients and pollutants, flood-damage mitigation, recreation, and the provision of cultural and aesthetic values. Incorporation of changes to the value of these services in land-use planning and decision making requires identification of the relevant services, engagement of stakeholders, knowledge of how land-use changes impact water quality, quantity, and timing, and mechanisms for putting value on the hydrologic and biogeochemical changes. We present three examples that highlight the characteristics, challenges, and opportunities associated with prototypical decisions that incorporate ecosystem services values: scenario analysis, payment for ecosystem services, and optimal spatial planning. Through these examples, we emphasize the challenges of data availability, model resolution and complexity, and attribution of value. We also provide some suggestions for ways forward.

  15. Statistical Challenges in Modeling Big Brain Signals

    KAUST Repository

    Yu, Zhaoxia

    2017-11-01

    Brain signal data are inherently big: massive in amount, complex in structure, and high in dimensions. These characteristics impose great challenges for statistical inference and learning. Here we review several key challenges, discuss possible solutions, and highlight future research directions.

  16. Statistical Challenges in Modeling Big Brain Signals

    KAUST Repository

    Yu, Zhaoxia; Pluta, Dustin; Shen, Tong; Chen, Chuansheng; Xue, Gui; Ombao, Hernando

    2017-01-01

    Brain signal data are inherently big: massive in amount, complex in structure, and high in dimensions. These characteristics impose great challenges for statistical inference and learning. Here we review several key challenges, discuss possible

  17. Integrated Environmental Modelling: Human decisions, human challenges

    Science.gov (United States)

    Glynn, Pierre D.

    2015-01-01

    Integrated Environmental Modelling (IEM) is an invaluable tool for understanding the complex, dynamic ecosystems that house our natural resources and control our environments. Human behaviour affects the ways in which the science of IEM is assembled and used for meaningful societal applications. In particular, human biases and heuristics reflect adaptation and experiential learning to issues with frequent, sharply distinguished, feedbacks. Unfortunately, human behaviour is not adapted to the more diffusely experienced problems that IEM typically seeks to address. Twelve biases are identified that affect IEM (and science in general). These biases are supported by personal observations and by the findings of behavioural scientists. A process for critical analysis is proposed that addresses some human challenges of IEM and solicits explicit description of (1) represented processes and information, (2) unrepresented processes and information, and (3) accounting for, and cognizance of, potential human biases. Several other suggestions are also made that generally complement maintaining attitudes of watchful humility, open-mindedness, honesty and transparent accountability. These suggestions include (1) creating a new area of study in the behavioural biogeosciences, (2) using structured processes for engaging the modelling and stakeholder communities in IEM, and (3) using ‘red teams’ to increase resilience of IEM constructs and use.

  18. Pharmacokinetic/pharmacodynamic modeling of benazepril and benazeprilat after administration of intravenous and oral doses of benazepril in healthy horses.

    Science.gov (United States)

    Serrano-Rodríguez, Juan Manuel; Gómez-Díez, Manuel; Esgueva, María; Castejón-Riber, Cristina; Mena-Bravo, Antonio; Priego-Capote, Feliciano; Ayala, Nahúm; Caballero, Juan Manuel Serrano; Muñoz, Ana

    2017-10-01

    Pharmacokinetic and pharmacodynamic (PK/PD) properties of the angiotensin-converting enzyme inhibitor (ACEI) benazeprilat have not been evaluated in horses. This study was designed to establish PK profiles for benazepril and benazeprilat after intravenous (IV) and oral (PO) administration of benazepril using a PK/PD model. This study also aims to determine the effects of benazeprilat on serum angiotensin converting enzyme (ACE), selecting the most appropriate dose that suppresses ACE activity. Six healthy horses in a crossover design received IV benazepril at 0.50mg/kg and PO at doses 0 (placebo), 0.25, 0.50 and 1.00mg/kg. Blood pressures (BP) were measured and blood samples were obtained at different times in order to measure serum drug concentrations and serum ACE activity, using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and spectrophotometry, respectively. Systemic bioavailability of benazeprilat after PO benazepril was 3-4%. Maximum ACE inhibitions from baseline were 99.63% (IV benazepril), 6.77% (placebo) and 78.91%, 85.74% and 89.51% (for the three PO benazepril doses). Significant differences in BP were not found. Although oral availability was low, benazeprilat 1.00mg/kg, reached sufficient serum concentrations to induce long lasting serum ACE inhibitions (between 88 and 50%) for the first 48h. Additional research on benazepril administration in equine patients is indicated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Challenges in Modeling of the Global Atmosphere

    Science.gov (United States)

    Janjic, Zavisa; Djurdjevic, Vladimir; Vasic, Ratko; Black, Tom

    2015-04-01

    ") with significant amplitudes can develop. Due to their large scales, that are comparable to the scales of the dominant Rossby waves, such fictitious solutions are hard to identify and remove. Another new challenge on the global scale is that the limit of validity of the hydrostatic approximation is rapidly being approached. Having in mind the sensitivity of extended deterministic forecasts to small disturbances, we may need global non-hydrostatic models sooner than we think. The unified Non-hydrostatic Multi-scale Model (NMMB) that is being developed at the National Centers for Environmental Prediction (NCEP) as a part of the new NOAA Environmental Modeling System (NEMS) will be discussed as an example. The non-hydrostatic dynamics were designed in such a way as to avoid over-specification. The global version is run on the latitude-longitude grid, and the polar filter selectively slows down the waves that would otherwise be unstable. The model formulation has been successfully tested on various scales. A global forecasting system based on the NMMB has been run in order to test and tune the model. The skill of the medium range forecasts produced by the NMMB is comparable to that of other major medium range models. The computational efficiency of the global NMMB on parallel computers is good.

  20. An anti-nicotinic cognitive challenge model using mecamylamine in comparison with the anti-muscarinic cognitive challenge using scopolamine.

    Science.gov (United States)

    Baakman, Anne Catrien; Alvarez-Jimenez, Ricardo; Rissmann, Robert; Klaassen, Erica S; Stevens, Jasper; Goulooze, Sebastiaan C; den Burger, Jeroen C G; Swart, Eleonora L; van Gerven, Joop M A; Groeneveld, Geert Jan

    2017-08-01

    The muscarinic acetylcholine receptor antagonist scopolamine is often used for proof-of-pharmacology studies with pro-cognitive compounds. From a pharmacological point of view, it would seem more rational to use a nicotinic rather than a muscarinic anticholinergic challenge to prove pharmacology of a nicotinic acetylcholine receptor agonist. This study aims to characterize a nicotinic anticholinergic challenge model using mecamylamine and to compare it to the scopolamine model. In this double-blind, placebo-controlled, four-way cross-over trial, 12 healthy male subjects received oral mecamylamine 10 and 20 mg, intravenous scopolamine 0.5 mg and placebo. Pharmacokinetics were analysed using non-compartmental analysis. Pharmacodynamic effects were measured with a multidimensional test battery that includes neurophysiological, subjective, (visuo)motor and cognitive measurements. All treatments were safe and well tolerated. Mecamylamine had a t max of 2.5 h and a C max of 64.5 ng ml -1 for the 20 mg dose. Mecamylamine had a dose-dependent effect decreasing the adaptive tracking performance and VAS alertness, and increasing the finger tapping and visual verbal learning task performance time and errors. Scopolamine significantly affected almost all pharmacodynamic tests. This study demonstrated that mecamylamine causes nicotinic receptor specific temporary decline in cognitive functioning. Compared with the scopolamine model, pharmacodynamic effects were less pronounced at the dose levels tested; however, mecamylamine caused less sedation. The cognitive effects of scopolamine might at least partly be caused by sedation. Whether the mecamylamine model can be used for proof-of-pharmacology of nicotinic acetylcholine receptor agonists remains to be established. © 2017 The British Pharmacological Society.

  1. Randomized comparison of intra-arterial and intravenous thrombolysis in a canine model of acute basilar artery thrombosis

    International Nuclear Information System (INIS)

    Qureshi, A.I.; Yahia, A.M.; Boulos, A.S.; Hanel, R.A.; Suri, M.F.K.; Hopkins, L.N.; Alberico, R.A.

    2004-01-01

    We compared the rates of recanalization cerebral infarct and hemorrhage between intra-arterial (IA) reteplase and intravenous (IV) alteplase thrombolysis in a canine model of basilar artery thrombosis. Thrombosis was induced by injecting a clot in the basilar artery of 13 anesthetized dogs via superselective catheterization. The animals were randomized in a blinded fashion, 2 h after clot injection and verification of arterial occlusion, to receive IV alteplase 0.9 mg/kg over 60 min and IA placebo, or IA reteplase 0.09 units/kg over 20 min, equivalent to one-half the alteplase dose, and IV placebo. Recanalization was studied for 6 h after treatment with serial angiography; the images were later graded in a blinded fashion. Blinded interpretation of postmortem MRI was performed to assess the presence of brain infarcts and/or hemorrhage. At 3 h after initiation of treatment, partial or complete recanalization was observed in one of six dogs in the IV alteplase group and in five of seven in the IA reteplase group (P = 0.08). At 6 h, no significant difference in partial or complete recanalization was observed between the groups (two of six vs. five of seven; P = 0.20). Postmortem MRI revealed infarcts in four of six animals treated with IV alteplase and three of seven treated with IA reteplase (P = 0.4). Intracerebral hemorrhage was more common in the IV alteplase group (four of six vs. none of seven; P = 0.02). This study thus suggests that IA thrombolysis affords a recanalization rate similar to that of IV thrombolysis, but with a lower rate of intracerebral hemorrhage. (orig.)

  2. Intraosseous Hydroxocobalamin versus Intravenous Hydroxocobalamin Compared to Intraosseous Whole Blood or No Treatment for Hemorrhagic Shock in a Swine Model

    Science.gov (United States)

    2016-05-02

    3794 5. Purpose: To determine if hydroxocobalamin, a portable, safe and FDA approved drug, is effective in improving hemorrhagic shock 6...Results: Intravenous (IV) versus proximal tibial intraosseous ( IO ) hydroxocobalamin (HOC) compared to no treatment: Systolic blood pressure, the...primary outcome variable, was similar between the IV and IO HOC groups over time. This was significantly different from the non-treated group such

  3. Kinetics of intravenous radiographic contrast medium injections as used on CT: simulation with time delay differential equations in a basic human cardiovascular multicompartment model.

    Science.gov (United States)

    Violon, D

    2012-12-01

    To develop a multicompartment model of only essential human body components that predicts the contrast medium concentration vs time curve in a chosen compartment after an intravenous injection. Also to show that the model can be used to time adequately contrast-enhanced CT series. A system of linked time delay instead of ordinary differential equations described the model and was solved with a Matlab program (Matlab v. 6.5; The Mathworks, Inc., Natick, MA). All the injection and physiological parameters were modified to cope with normal or pathological situations. In vivo time-concentration curves from the literature were recalculated to validate the model. The recalculated contrast medium time-concentration curves and parameters are given. The results of the statistical analysis of the study findings are expressed as the median prediction error and the median absolute prediction error values for both the time delay and ordinary differential equation systems; these are situated well below the generally accepted maximum 20% limit. The presented program correctly predicts the time-concentration curve of an intravenous contrast medium injection and, consequently, allows an individually tailored approach of CT examinations with optimised use of the injected contrast medium volume, as long as time delay instead of ordinary differential equations are used. The presented program offers good preliminary knowledge of the time-contrast medium concentration curve after any intravenous injection, allowing adequate timing of a CT examination, required by the short scan time of present-day scanners. The injected volume of contrast medium can be tailored to the individual patient with no more contrast medium than is strictly needed.

  4. Intentional intravenous mercury injection

    African Journals Online (AJOL)

    In this case report, intravenous complications, treatment strategies and possible ... Mercury toxicity is commonly associated with vapour inhalation or oral ingestion, for which there exist definite treatment options. Intravenous mercury ... personality, anxiousness, irritability, insomnia, depression and drowsi- ness.[1] However ...

  5. Toxicokinetic modeling challenges for aquatic nanotoxicology

    Directory of Open Access Journals (Sweden)

    Wei-Yu eChen

    2016-01-01

    Full Text Available Nanotoxicity has become of increasing concern since the rapid development of metal nanoparticles (NPs. Aquatic nanotoxicity depends on crucial qualitative and quantitative properties of nanomaterials that induce adverse effects on subcellular, tissue, and organ level. The dose-response effects of size-dependent metal NPs, however, are not well investigated in aquatic organisms. In order to determine the uptake and elimination rate constants for metal NPs in the metabolically active/ detoxified pool of tissues, a one-compartmental toxicokinetic model can be applied when subcellular partitioning of metal NPs data would be available. The present review is an attempt to describe the nano-characteristics of toxicokinetics and subcellular partitioning on aquatic organisms with the help of the mechanistic modeling for NP size-dependent physiochemical properties and parameters. Physiologically-based pharmacokinetic (PBPK models can provide an effective tool to estimate the time course of NP accumulation in target organs and is useful in quantitative risk assessments. NP accumulation in fish should take into account different effects of different NP sizes to better understand tissue accumulative capacities and dynamics. The size-dependent NP partition coefficient is a crucial parameter that influences tissue accumulation levels in PBPK modeling. Further research is needed to construct the effective systems-level oriented toxicokinetic model that can provide a useful tool to develop quantitatively the robustly approximate relations that convey a better insight into the impacts of environmental metal NPs on subcellular and tissue/organ responses in aquatic organisms.

  6. Theorists reject challenge to standard model

    CERN Multimedia

    Adam, D

    2001-01-01

    Particle physicists are questioning results that appear to violate the Standard Model. There are concerns that there is not sufficient statistical significance and also charges that the comparison is being made with the 'most convenient' theoretical value for the muon's magnetic moment (1 page).

  7. GEOS Atmospheric Model: Challenges at Exascale

    Science.gov (United States)

    Putman, William M.; Suarez, Max J.

    2017-01-01

    The Goddard Earth Observing System (GEOS) model at NASA's Global Modeling and Assimilation Office (GMAO) is used to simulate the multi-scale variability of the Earth's weather and climate, and is used primarily to assimilate conventional and satellite-based observations for weather forecasting and reanalysis. In addition, assimilations coupled to an ocean model are used for longer-term forecasting (e.g., El Nino) on seasonal to interannual times-scales. The GMAO's research activities, including system development, focus on numerous time and space scales, as detailed on the GMAO website, where they are tabbed under five major themes: Weather Analysis and Prediction; Seasonal-Decadal Analysis and Prediction; Reanalysis; Global Mesoscale Modeling, and Observing System Science. A brief description of the GEOS systems can also be found at the GMAO website. GEOS executes as a collection of earth system components connected through the Earth System Modeling Framework (ESMF). The ESMF layer is supplemented with the MAPL (Modeling, Analysis, and Prediction Layer) software toolkit developed at the GMAO, which facilitates the organization of the computational components into a hierarchical architecture. GEOS systems run in parallel using a horizontal decomposition of the Earth's sphere into processing elements (PEs). Communication between PEs is primarily through a message passing framework, using the message passing interface (MPI), and through explicit use of node-level shared memory access via the SHMEM (Symmetric Hierarchical Memory access) protocol. Production GEOS weather prediction systems currently run at 12.5-kilometer horizontal resolution with 72 vertical levels decomposed into PEs associated with 5,400 MPI processes. Research GEOS systems run at resolutions as fine as 1.5 kilometers globally using as many as 30,000 MPI processes. Looking forward, these systems can be expected to see a 2 times increase in horizontal resolution every two to three years, as well as

  8. Transnational nursing programs: models, advantages and challenges.

    Science.gov (United States)

    Wilson, Michael

    2002-07-01

    Conducting transnational programs can be a very rewarding activity for a School, Faculty or University. Apart from increasing the profile of the university, the conduct of transnational programs can also provide the university with openings for business opportunities, consultative activities, and collaborative research. It can also be a costly exercise placing an enormous strain on limited resources with little reward for the provider. Transnational ventures can become nonviable entities in a very short period of time due to unanticipated global economic trends. Transnational courses offered by Faculties of Business and Computing are commonplace, however, there is a growing number of health science programs, particularly nursing that are being offered transnational. This paper plans an overview of several models employed for the delivery of transnational nursing courses and discusses several key issues pertaining to conducting courses outside the host university's country.

  9. Value Creation Challenges in Multichannel Retail Business Models

    Directory of Open Access Journals (Sweden)

    Mika Yrjölä

    2014-08-01

    Full Text Available Purpose: The purpose of the paper is to identify and analyze the challenges of value creation in multichannel retail business models. Design/methodology/approach: With the help of semi-structured interviews with top executives from different retailing environments, this study introduces a model of value creation challenges in the context of multichannel retailing. The challenges are analyzed in terms of three retail business model elements, i.e., format, activities, and governance. Findings: Adopting a multichannel retail business model requires critical rethinking of the basic building blocks of value creation. First of all, as customers effortlessly move between multiple channels, multichannel formats can lead to a mismatch between customer and firm value. Secondly, retailers face pressures to use their activities to form integrated total offerings to customers. Thirdly, multiple channels might lead to organizational silos with conflicting goals. A careful orchestration of value creation is needed to determine the roles and incentives of the channel parties involved. Research limitations/implications: In contrast to previous business model literature, this study did not adopt a network-centric view. By embracing the boundary-spanning nature of the business model, other challenges and elements might have been discovered (e.g., challenges in managing relationships with suppliers. Practical implications: As a practical contribution, this paper has analyzed the challenges retailers face in adopting multichannel business models. Customer tendencies for showrooming behavior highlight the need for generating efficient lock-in strategies. Customized, personal offers and information are ways to increase customer value, differentiate from competition, and achieve lock-in. Originality/value: As a theoretical contribution, this paper empirically investigates value creation challenges in a specific context, lowering the level of abstraction in the mostly

  10. Geospace environment modeling 2008--2009 challenge: Dst index

    Science.gov (United States)

    Rastätter, L.; Kuznetsova, M.M.; Glocer, A.; Welling, D.; Meng, X.; Raeder, J.; Wittberger, M.; Jordanova, V.K.; Yu, Y.; Zaharia, S.; Weigel, R.S.; Sazykin, S.; Boynton, R.; Wei, H.; Eccles, V.; Horton, W.; Mays, M.L.; Gannon, J.

    2013-01-01

    This paper reports the metrics-based results of the Dst index part of the 2008–2009 GEM Metrics Challenge. The 2008–2009 GEM Metrics Challenge asked modelers to submit results for four geomagnetic storm events and five different types of observations that can be modeled by statistical, climatological or physics-based models of the magnetosphere-ionosphere system. We present the results of 30 model settings that were run at the Community Coordinated Modeling Center and at the institutions of various modelers for these events. To measure the performance of each of the models against the observations, we use comparisons of 1 hour averaged model data with the Dst index issued by the World Data Center for Geomagnetism, Kyoto, Japan, and direct comparison of 1 minute model data with the 1 minute Dst index calculated by the United States Geological Survey. The latter index can be used to calculate spectral variability of model outputs in comparison to the index. We find that model rankings vary widely by skill score used. None of the models consistently perform best for all events. We find that empirical models perform well in general. Magnetohydrodynamics-based models of the global magnetosphere with inner magnetosphere physics (ring current model) included and stand-alone ring current models with properly defined boundary conditions perform well and are able to match or surpass results from empirical models. Unlike in similar studies, the statistical models used in this study found their challenge in the weakest events rather than the strongest events.

  11. Impact of intravenous immunoglobulin on the dopaminergic system and immune response in the acute MPTP mouse model of Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    St-Amour Isabelle

    2012-10-01

    Full Text Available Abstract Intravenous immunoglobulin (IVIg is a blood-derived product, used for the treatment of immunodeficiency and autoimmune diseases. Since a range of immunotherapies have recently been proposed as a therapeutic strategy for Parkinson’s disease (PD, we investigated the effects of an IVIg treatment in a neurotoxin-induced animal model of PD. Mice received four injections of MPTP (15 mg/kg at 2-hour intervals followed by a 14-day IVIg treatment, which induced key immune-related changes such as increased regulatory T-cell population and decreased CD4+/CD8+ ratio. The MPTP treatment induced significant 80% and 84% decreases of striatal dopamine concentrations (P P P 

  12. Acute cardiac support with intravenous milrinone promotes recovery from early brain injury in a murine model of severe subarachnoid haemorrhage.

    Science.gov (United States)

    Mutoh, Tomoko; Mutoh, Tatsushi; Nakamura, Kazuhiro; Yamamoto, Yukiko; Tsuru, Yoshiharu; Tsubone, Hirokazu; Ishikawa, Tatsuya; Taki, Yasuyuki

    2017-04-01

    Early brain injury/ischaemia (EBI) is a serious complication early after subarachnoid haemorrhage (SAH) that contributes to development of delayed cerebral ischaemia (DCI). This study aimed to determine the role of inotropic cardiac support using milrinone (MIL) on restoring acute cerebral hypoperfusion attributable to EBI and improving outcomes after experimental SAH. Forty-three male C57BL/6 mice were assigned to either sham surgery (SAH-sham), SAH induced by endovascular perforation plus postconditioning with 2% isoflurane (Control), or SAH plus isoflurane combined with MIL with and without hypoxia-inducible factor inhibitor (HIF-I) pretreatment. Cardiac output (CO) during intravenous MIL infusion (0.25-0.75 μg/kg/min) between 1.5 and 2.5 hours after SAH induction was monitored with Doppler echocardiography. Magnetic resonance imaging (MRI)-continuous arterial spin labelling was used for quantitative cerebral blood flow (CBF) measurements. Neurobehavioral function was assessed daily by neurological score and open field test. DCI was analyzed 3 days later by determining infarction on MRI. Mild reduction of cardiac output (CO) and global cerebral blood flow (CBF) depression were notable early after SAH. MIL increased CO in a dose-dependent manner (P<.001), which was accompanied by improved hypoperfusion, incidence of DCI and functional recovery than Control (P<.05). The neuroprotective effects afforded by MIL or Control were attenuated by hypoxia-inducible factor (HIF) inhibition (P<.05). These results suggest that MIL improves acute hypoperfusion by its inotropic effect, leading to neurobehavioral improvement in mice after severe SAH, in which HIF may be acting as a critical mediator. © 2017 John Wiley & Sons Australia, Ltd.

  13. Challenges and opportunities for integrating lake ecosystem modelling approaches

    Science.gov (United States)

    Mooij, Wolf M.; Trolle, Dennis; Jeppesen, Erik; Arhonditsis, George; Belolipetsky, Pavel V.; Chitamwebwa, Deonatus B.R.; Degermendzhy, Andrey G.; DeAngelis, Donald L.; Domis, Lisette N. De Senerpont; Downing, Andrea S.; Elliott, J. Alex; Ruberto, Carlos Ruberto; Gaedke, Ursula; Genova, Svetlana N.; Gulati, Ramesh D.; Hakanson, Lars; Hamilton, David P.; Hipsey, Matthew R.; Hoen, Jochem 't; Hulsmann, Stephan; Los, F. Hans; Makler-Pick, Vardit; Petzoldt, Thomas; Prokopkin, Igor G.; Rinke, Karsten; Schep, Sebastiaan A.; Tominaga, Koji; Van Dam, Anne A.; Van Nes, Egbert H.; Wells, Scott A.; Janse, Jan H.

    2010-01-01

    A large number and wide variety of lake ecosystem models have been developed and published during the past four decades. We identify two challenges for making further progress in this field. One such challenge is to avoid developing more models largely following the concept of others ('reinventing the wheel'). The other challenge is to avoid focusing on only one type of model, while ignoring new and diverse approaches that have become available ('having tunnel vision'). In this paper, we aim at improving the awareness of existing models and knowledge of concurrent approaches in lake ecosystem modelling, without covering all possible model tools and avenues. First, we present a broad variety of modelling approaches. To illustrate these approaches, we give brief descriptions of rather arbitrarily selected sets of specific models. We deal with static models (steady state and regression models), complex dynamic models (CAEDYM, CE-QUAL-W2, Delft 3D-ECO, LakeMab, LakeWeb, MyLake, PCLake, PROTECH, SALMO), structurally dynamic models and minimal dynamic models. We also discuss a group of approaches that could all be classified as individual based: super-individual models (Piscator, Charisma), physiologically structured models, stage-structured models and trait-based models. We briefly mention genetic algorithms, neural networks, Kalman filters and fuzzy logic. Thereafter, we zoom in, as an in-depth example, on the multi-decadal development and application of the lake ecosystem model PCLake and related models (PCLake Metamodel, Lake Shira Model, IPH-TRIM3D-PCLake). In the discussion, we argue that while the historical development of each approach and model is understandable given its 'leading principle', there are many opportunities for combining approaches. We take the point of view that a single 'right' approach does not exist and should not be strived for. Instead, multiple modelling approaches, applied concurrently to a given problem, can help develop an integrative

  14. Editorial: Modelling and computational challenges in granular materials

    NARCIS (Netherlands)

    Weinhart, Thomas; Thornton, Anthony Richard; Einav, Itai

    2015-01-01

    This is the editorial for the special issue on “Modelling and computational challenges in granular materials” in the journal on Computational Particle Mechanics (CPM). The issue aims to provide an opportunity for physicists, engineers, applied mathematicians and computational scientists to discuss

  15. International Students Take Up the Model Solar Car Challenge.

    Science.gov (United States)

    Wellington, Paul

    2000-01-01

    Introduces an event in which two school teams from Argentina and Vietnam joined those from each Australian state in a race of model cars powered by the sun that provides a challenging and exciting approach for students to apply their scientific and technological knowledge to design and build the most efficient vehicles possible to gain hands-on…

  16. Multiphysics software and the challenge to validating physical models

    International Nuclear Information System (INIS)

    Luxat, J.C.

    2008-01-01

    This paper discusses multi physics software and validation of physical models in the nuclear industry. The major challenge is to convert the general purpose software package to a robust application-specific solution. This requires greater knowledge of the underlying solution techniques and the limitations of the packages. Good user interfaces and neat graphics do not compensate for any deficiencies

  17. Editorial: Modelling and computational challenges in granular materials

    OpenAIRE

    Weinhart, Thomas; Thornton, Anthony Richard; Einav, Itai

    2015-01-01

    This is the editorial for the special issue on “Modelling and computational challenges in granular materials” in the journal on Computational Particle Mechanics (CPM). The issue aims to provide an opportunity for physicists, engineers, applied mathematicians and computational scientists to discuss the current progress and latest advancements in the field of advanced numerical methods and modelling of granular materials. The focus will be on computational methods, improved algorithms and the m...

  18. Modeling and Management of Big Data: Challenges and opportunities

    OpenAIRE

    Gil, David; Song, Il-Yeol

    2016-01-01

    The term Big Data denotes huge-volume, complex, rapid growing datasets with numerous, autonomous and independent sources. In these new circumstances Big Data bring many attractive opportunities; however, good opportunities are always followed by challenges, such as modelling, new paradigms, novel architectures that require original approaches to address data complexities. The purpose of this special issue on Modeling and Management of Big Data is to discuss research and experience in modellin...

  19. Intravenous thrombolysis of large vessel occlusions is associated with higher hospital costs than small vessel strokes: a rationale for developing stroke severity-based financial models.

    Science.gov (United States)

    Rai, Ansaar T; Evans, Kim; Riggs, Jack E; Hobbs, Gerald R

    2016-04-01

    Owing to their severity, large vessel occlusion (LVO) strokes may be associated with higher costs that are not reflected in current coding systems. This study aimed to determine whether intravenous thrombolysis costs are related to the presence or absence of LVO. Patients who had undergone intravenous thrombolysis over a 9-year period were divided into LVO and no LVO (nLVO) groups based on admission CT angiography. The primary outcome was hospital cost per admission. Secondary outcomes included admission duration, 90-day clinical outcome, and discharge destination. 119 patients (53%) had LVO and 104 (47%) had nLVO. Total mean±SD cost per LVO patient was $18,815±14,262 compared with $15,174±11,769 per nLVO patient (p=0.04). Hospital payments per admission were $17,338±13,947 and $15,594±16,437 for LVO and nLVO patients, respectively (p=0.4). A good outcome was seen in 33 LVO patients (27.7%) and in 69 nLVO patients (66.4%) (OR 0.2, 95% CI 0.1 to 0.3, pregression analysis after controlling for comorbidities showed the presence of LVO to be an independent predictor of higher total hospital costs. The presence or absence of LVO is associated with significant differences in hospital costs, outcomes, admission duration, and home discharge. These differences can be important when developing systems of care models for acute ischemic stroke. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  20. Crowd Sourcing for Challenging Technical Problems and Business Model

    Science.gov (United States)

    Davis, Jeffrey R.; Richard, Elizabeth

    2011-01-01

    imaging, microbial detection and even the use of pharmaceuticals for radiation protection. The internal challenges through NASA@Work drew over 6000 participants across all NASA centers. Challenges conducted by each NASA center elicited ideas and solutions from several other NASA centers and demonstrated rapid and efficient participation from employees at multiple centers to contribute to problem solving. Finally, on January 19, 2011, the SLSD conducted a workshop on open collaboration and innovation strategies and best practices through the newly established NASA Human Health and Performance Center (NHHPC). Initial projects will be described leading to a new business model for SLSD.

  1. Research Challenges in Financial Data Modeling and Analysis.

    Science.gov (United States)

    Alexander, Lewis; Das, Sanjiv R; Ives, Zachary; Jagadish, H V; Monteleoni, Claire

    2017-09-01

    Significant research challenges must be addressed in the cleaning, transformation, integration, modeling, and analytics of Big Data sources for finance. This article surveys the progress made so far in this direction and obstacles yet to be overcome. These are issues that are of interest to data-driven financial institutions in both corporate finance and consumer finance. These challenges are also of interest to the legal profession as well as to regulators. The discussion is relevant to technology firms that support the growing field of FinTech.

  2. Modelling across bioreactor scales: methods, challenges and limitations

    DEFF Research Database (Denmark)

    Gernaey, Krist

    that it is challenging and expensive to acquire experimental data of good quality that can be used for characterizing gradients occurring inside a large industrial scale bioreactor. But which model building methods are available? And how can one ensure that the parameters in such a model are properly estimated? And what......Scale-up and scale-down of bioreactors are very important in industrial biotechnology, especially with the currently available knowledge on the occurrence of gradients in industrial-scale bioreactors. Moreover, it becomes increasingly appealing to model such industrial scale systems, considering...

  3. Gradient Models in Molecular Biophysics: Progress, Challenges, Opportunities.

    Science.gov (United States)

    Bardhan, Jaydeep P

    2013-12-01

    In the interest of developing a bridge between researchers modeling materials and those modeling biological molecules, we survey recent progress in developing nonlocal-dielectric continuum models for studying the behavior of proteins and nucleic acids. As in other areas of science, continuum models are essential tools when atomistic simulations (e.g. molecular dynamics) are too expensive. Because biological molecules are essentially all nanoscale systems, the standard continuum model, involving local dielectric response, has basically always been dubious at best. The advanced continuum theories discussed here aim to remedy these shortcomings by adding features such as nonlocal dielectric response, and nonlinearities resulting from dielectric saturation. We begin by describing the central role of electrostatic interactions in biology at the molecular scale, and motivate the development of computationally tractable continuum models using applications in science and engineering. For context, we highlight some of the most important challenges that remain and survey the diverse theoretical formalisms for their treatment, highlighting the rigorous statistical mechanics that support the use and improvement of continuum models. We then address the development and implementation of nonlocal dielectric models, an approach pioneered by Dogonadze, Kornyshev, and their collaborators almost forty years ago. The simplest of these models is just a scalar form of gradient elasticity, and here we use ideas from gradient-based modeling to extend the electrostatic model to include additional length scales. The paper concludes with a discussion of open questions for model development, highlighting the many opportunities for the materials community to leverage its physical, mathematical, and computational expertise to help solve one of the most challenging questions in molecular biology and biophysics.

  4. Gradient Models in Molecular Biophysics: Progress, Challenges, Opportunities

    Science.gov (United States)

    Bardhan, Jaydeep P.

    2014-01-01

    In the interest of developing a bridge between researchers modeling materials and those modeling biological molecules, we survey recent progress in developing nonlocal-dielectric continuum models for studying the behavior of proteins and nucleic acids. As in other areas of science, continuum models are essential tools when atomistic simulations (e.g. molecular dynamics) are too expensive. Because biological molecules are essentially all nanoscale systems, the standard continuum model, involving local dielectric response, has basically always been dubious at best. The advanced continuum theories discussed here aim to remedy these shortcomings by adding features such as nonlocal dielectric response, and nonlinearities resulting from dielectric saturation. We begin by describing the central role of electrostatic interactions in biology at the molecular scale, and motivate the development of computationally tractable continuum models using applications in science and engineering. For context, we highlight some of the most important challenges that remain and survey the diverse theoretical formalisms for their treatment, highlighting the rigorous statistical mechanics that support the use and improvement of continuum models. We then address the development and implementation of nonlocal dielectric models, an approach pioneered by Dogonadze, Kornyshev, and their collaborators almost forty years ago. The simplest of these models is just a scalar form of gradient elasticity, and here we use ideas from gradient-based modeling to extend the electrostatic model to include additional length scales. The paper concludes with a discussion of open questions for model development, highlighting the many opportunities for the materials community to leverage its physical, mathematical, and computational expertise to help solve one of the most challenging questions in molecular biology and biophysics. PMID:25505358

  5. Gradient models in molecular biophysics: progress, challenges, opportunities

    Science.gov (United States)

    Bardhan, Jaydeep P.

    2013-12-01

    In the interest of developing a bridge between researchers modeling materials and those modeling biological molecules, we survey recent progress in developing nonlocal-dielectric continuum models for studying the behavior of proteins and nucleic acids. As in other areas of science, continuum models are essential tools when atomistic simulations (e.g., molecular dynamics) are too expensive. Because biological molecules are essentially all nanoscale systems, the standard continuum model, involving local dielectric response, has basically always been dubious at best. The advanced continuum theories discussed here aim to remedy these shortcomings by adding nonlocal dielectric response. We begin by describing the central role of electrostatic interactions in biology at the molecular scale, and motivate the development of computationally tractable continuum models using applications in science and engineering. For context, we highlight some of the most important challenges that remain, and survey the diverse theoretical formalisms for their treatment, highlighting the rigorous statistical mechanics that support the use and improvement of continuum models. We then address the development and implementation of nonlocal dielectric models, an approach pioneered by Dogonadze, Kornyshev, and their collaborators almost 40 years ago. The simplest of these models is just a scalar form of gradient elasticity, and here we use ideas from gradient-based modeling to extend the electrostatic model to include additional length scales. The review concludes with a discussion of open questions for model development, highlighting the many opportunities for the materials community to leverage its physical, mathematical, and computational expertise to help solve one of the most challenging questions in molecular biology and biophysics.

  6. A Comparison of the Effects of Intraosseous and Intravenous 5% Albumin on Infusion Time and Hemodynamic Measures in a Swine Model of Hemorrhagic Shock.

    Science.gov (United States)

    Muir, Stacy L; Sheppard, Lance B; Maika-Wilson, Anne; Burgert, James M; Garcia-Blanco, Jose; Johnson, Arthur D; Coyner, Jennifer L

    2016-08-01

    Introduction Obtaining intravenous (IV) access in patients in hemorrhagic shock is often difficult and prolonged. Failed IV attempts delay life-saving treatment. Intraosseous (IO) access may often be obtained faster than IV access. Albumin (5%) is an option for prehospital volume expansion because of the absence of interference with coagulation and platelet function. Hypothesis/Problem There are limited data comparing the performance of IO and IV administered 5% albumin. The aims of this study were to compare the effects of tibial IO (TIO) and IV administration of 500 mL of 5% albumin on infusion time and hemodynamic measurements of heart rate (HR), mean arterial pressure (MAP), cardiac output (CO), and stroke volume (SV) in a swine model of hemorrhagic shock. Sixteen male swine were divided into two groups: TIO and IV. All subjects were anesthetized and a Class III hemorrhage was achieved by exsanguination of 31% of estimated blood volume (EBV) from a femoral artery catheter. Following exsanguination, 500 mL of 5% albumin was administered under pressurized infusion (300 mmHg) by the TIO or IV route and infusion time was recorded. Hemodynamic measurements of HR, MAP, CO, and SV were collected before and after exsanguination and every 20 seconds for 180 seconds during 5% albumin infusion. An independent t-test determined that IV 5% albumin infusion was significantly faster compared to IO (P=.01). Mean infusion time for TIO was seven minutes 35 seconds (SD=two minutes 44 seconds) compared to four minutes 32 seconds (SD=one minute 08 seconds) in the IV group. Multivariate Analysis of Variance was performed on hemodynamic data collected during the 5% albumin infusion. Analyses indicated there were no significant differences between the TIO and IV groups relative to MAP, CO, HR, or SV (P>.05). While significantly longer to infuse 5% albumin by the TIO route, the longer TIO infusion time may be negated as IO devices can be placed more quickly compared to repeated IV

  7. Computed tomography intravenous cholangiography

    International Nuclear Information System (INIS)

    Nascimento, S.; Murray, W.; Wilson, P.

    1997-01-01

    Indications for direct visualization of the bile ducts include bile duct dilatation demonstrated by ultrasound or computed tomography (CT) scanning, where the cause of the bile duct dilatation is uncertain or where the anatomy of bile duct obstruction needs further clarification. Another indication is right upper quadrant pain, particularly in a post-cholecystectomy patient, where choledocholithiasis is suspected. A possible new indication is pre-operative evaluation prior to laparoscopic cholecystectomy. The bile ducts are usually studied by endoscopic retrograde cholangiopancreatography (ERCP), or, less commonly, trans-hepatic cholangiography. The old technique of intravenous cholangiography has fallen into disrepute because of inconsistent bile-duct opacification. The advent of spiral CT scanning has renewed interest in intravenous cholangiography. The CT technique is very sensitive to the contrast agent in the bile ducts, and angiographic and three-dimensional reconstructions of the biliary tree can readily be obtained using the CT intravenous cholangiogram technique (CT IVC). Seven patients have been studied using this CT IVC technique, between February 1995 and June 1996, and are the subject of the present report. Eight further studies have since been performed. The results suggest that CT IVC could replace ERCP as the primary means of direct cholangiography, where pancreatic duct visualization is not required. (authors)

  8. The status and challenge of global fire modelling

    Science.gov (United States)

    Hantson, Stijn; Arneth, Almut; Harrison, Sandy P.; Kelley, Douglas I.; Prentice, I. Colin; Rabin, Sam S.; Archibald, Sally; Mouillot, Florent; Arnold, Steve R.; Artaxo, Paulo; Bachelet, Dominique; Ciais, Philippe; Forrest, Matthew; Friedlingstein, Pierre; Hickler, Thomas; Kaplan, Jed O.; Kloster, Silvia; Knorr, Wolfgang; Lasslop, Gitta; Li, Fang; Mangeon, Stephane; Melton, Joe R.; Meyn, Andrea; Sitch, Stephen; Spessa, Allan; van der Werf, Guido R.; Voulgarakis, Apostolos; Yue, Chao

    2016-06-01

    Biomass burning impacts vegetation dynamics, biogeochemical cycling, atmospheric chemistry, and climate, with sometimes deleterious socio-economic impacts. Under future climate projections it is often expected that the risk of wildfires will increase. Our ability to predict the magnitude and geographic pattern of future fire impacts rests on our ability to model fire regimes, using either well-founded empirical relationships or process-based models with good predictive skill. While a large variety of models exist today, it is still unclear which type of model or degree of complexity is required to model fire adequately at regional to global scales. This is the central question underpinning the creation of the Fire Model Intercomparison Project (FireMIP), an international initiative to compare and evaluate existing global fire models against benchmark data sets for present-day and historical conditions. In this paper we review how fires have been represented in fire-enabled dynamic global vegetation models (DGVMs) and give an overview of the current state of the art in fire-regime modelling. We indicate which challenges still remain in global fire modelling and stress the need for a comprehensive model evaluation and outline what lessons may be learned from FireMIP.

  9. Unfolding Challenges of Business Model Innovation towards Circular Economy

    DEFF Research Database (Denmark)

    Hvass, Kerli Kant

    2017-01-01

    of customers where it is important to see them as suppliers and co-producers of post-consumer value of products and materials. Finally, integrating circular economy strategies into business models may bring along radical changes to how companies perceive its products and relationships with customers and other...... model. The paper is based on empirical findings from a 34 month long qualitative case study of a leading Scandinavian fashion brand and the study followed an engaged scholarship strategy (Van de Ven, 2007). The findings identify issues and challenges that impact the successful implementation...

  10. Pharmacokinetic-Pharmacodynamic Modelling of the Analgesic and Antihyperalgesic Effects of Morphine after Intravenous Infusion in Human Volunteers

    DEFF Research Database (Denmark)

    Ravn, Pernille; Foster, David J. R.; Kreilgaard, Mads

    2014-01-01

    Using a modelling approach, this study aimed to (i) examine whether the pharmacodynamics of the analgesic and antihyperalgesic effects of morphine differ; (ii) investigate the influence of demographic, pain sensitivity and genetic (OPRM1) variables on between-subject variability of morphine...... pharmacokinetics and pharmacodynamics in human experimental pain models. The study was a randomized, double-blind, 5-arm, cross-over, placebo-controlled study. The psychophysical cutaneous pain tests, electrical pain tolerance (EPTo) and secondary hyperalgesia areas (2HA) were studied in 28 healthy individuals (15...

  11. Challenges in Materials Transformation Modeling for Polyolefins Industry

    Science.gov (United States)

    Lai, Shih-Yaw; Swogger, Kurt W.

    2004-06-01

    Unlike most published polymer processing and/or forming research, the transformation of polyolefins to fabricated articles often involves non-confined flow or so-called free surface flow (e.g. fiber spinning, blown films, and cast films) in which elongational flow takes place during a fabrication process. Obviously, the characterization and validation of extensional rheological parameters and their use to develop rheological constitutive models are the focus of polyolefins materials transformation research. Unfortunately, there are challenges that remain with limited validation for non-linear, non-isothermal constitutive models for polyolefins. Further complexity arises in the transformation of polyolefins in the elongational flow system as it involves stress-induced crystallization process. The complicated nature of elongational, non-linear rheology and non-isothermal crystallization kinetics make the development of numerical methods very challenging for the polyolefins materials forming modeling. From the product based company standpoint, the challenges of materials transformation research go beyond elongational rheology, crystallization kinetics and its numerical modeling. In order to make models useful for the polyolefin industry, it is critical to develop links between molecular parameters to both equipment and materials forming parameters. The recent advances in the constrained geometry catalysis and materials sciences understanding (INSITE technology and molecular design capability) has made industrial polyolefinic materials forming modeling more viable due to the fact that the molecular structure of the polymer can be well predicted and controlled during the polymerization. In this paper, we will discuss inter-relationship (models) among molecular parameters such as polymer molecular weight (Mw), molecular weight distribution (MWD), long chain branching (LCB), short chain branching (SCB or comonomer types and distribution) and their affects on shear and

  12. Investigation of Intravenous Hydroxocobalamin Compared to Hextend for Resuscitation in a Swine Model of Uncontrolled Hemorrhagic Shock: A Preliminary Report

    Science.gov (United States)

    2017-08-27

    in blood loss from the injury (1005 vs 1100 ml). There was a significant difference by time between groups (pɘ.5) post treatment. No significant...effective as IV Hextend® in improving systolic blood pressure (SBP) in a controlled hemorrhagic shock model. We aimed to compare IV hydroxocobalamin (HOC...volume, portable drug that improves blood pressure and survival. Objective To compare systolic blood pressure over time in swine that have

  13. Six challenges in modelling for public health policy.

    Science.gov (United States)

    Metcalf, C J E; Edmunds, W J; Lessler, J

    2015-03-01

    The World Health Organisation's definition of public health refers to all organized measures to prevent disease, promote health, and prolong life among the population as a whole (World Health Organization, 2014). Mathematical modelling plays an increasingly important role in helping to guide the most high impact and cost-effective means of achieving these goals. Public health programmes are usually implemented over a long period of time with broad benefits to many in the community. Clinical trials are seldom large enough to capture these effects. Observational data may be used to evaluate a programme after it is underway, but have limited value in helping to predict the future impact of a proposed policy. Furthermore, public health practitioners are often required to respond to new threats, for which there is little or no previous data on which to assess the threat. Computational and mathematical models can help to assess potential threats and impacts early in the process, and later aid in interpreting data from complex and multifactorial systems. As such, these models can be critical tools in guiding public health action. However, there are a number of challenges in achieving a successful interface between modelling and public health. Here, we discuss some of these challenges. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Six challenges in modelling for public health policy

    Directory of Open Access Journals (Sweden)

    C.J.E. Metcalf

    2015-03-01

    Full Text Available The World Health Organisation's definition of public health refers to all organized measures to prevent disease, promote health, and prolong life among the population as a whole (World Health Organization, 2014. Mathematical modelling plays an increasingly important role in helping to guide the most high impact and cost-effective means of achieving these goals. Public health programmes are usually implemented over a long period of time with broad benefits to many in the community. Clinical trials are seldom large enough to capture these effects. Observational data may be used to evaluate a programme after it is underway, but have limited value in helping to predict the future impact of a proposed policy. Furthermore, public health practitioners are often required to respond to new threats, for which there is little or no previous data on which to assess the threat. Computational and mathematical models can help to assess potential threats and impacts early in the process, and later aid in interpreting data from complex and multifactorial systems. As such, these models can be critical tools in guiding public health action. However, there are a number of challenges in achieving a successful interface between modelling and public health. Here, we discuss some of these challenges.

  15. Citizen observations contributing to flood modelling: opportunities and challenges

    Directory of Open Access Journals (Sweden)

    T. H. Assumpção

    2018-02-01

    Full Text Available Citizen contributions to science have been successfully implemented in many fields, and water resources is one of them. Through citizens, it is possible to collect data and obtain a more integrated decision-making process. Specifically, data scarcity has always been an issue in flood modelling, which has been addressed in the last decades by remote sensing and is already being discussed in the citizen science context. With this in mind, this article aims to review the literature on the topic and analyse the opportunities and challenges that lie ahead. The literature on monitoring, mapping and modelling, was evaluated according to the flood-related variable citizens contributed to. Pros and cons of the collection/analysis methods were summarised. Then, pertinent publications were mapped into the flood modelling cycle, considering how citizen data properties (spatial and temporal coverage, uncertainty and volume are related to its integration into modelling. It was clear that the number of studies in the area is rising. There are positive experiences reported in collection and analysis methods, for instance with velocity and land cover, and also when modelling is concerned, for example by using social media mining. However, matching the data properties necessary for each part of the modelling cycle with citizen-generated data is still challenging. Nevertheless, the concept that citizen contributions can be used for simulation and forecasting is proved and further work lies in continuing to develop and improve not only methods for collection and analysis, but certainly for integration into models as well. Finally, in view of recent automated sensors and satellite technologies, it is through studies as the ones analysed in this article that the value of citizen contributions, complementing such technologies, is demonstrated.

  16. Citizen observations contributing to flood modelling: opportunities and challenges

    Science.gov (United States)

    Assumpção, Thaine H.; Popescu, Ioana; Jonoski, Andreja; Solomatine, Dimitri P.

    2018-02-01

    Citizen contributions to science have been successfully implemented in many fields, and water resources is one of them. Through citizens, it is possible to collect data and obtain a more integrated decision-making process. Specifically, data scarcity has always been an issue in flood modelling, which has been addressed in the last decades by remote sensing and is already being discussed in the citizen science context. With this in mind, this article aims to review the literature on the topic and analyse the opportunities and challenges that lie ahead. The literature on monitoring, mapping and modelling, was evaluated according to the flood-related variable citizens contributed to. Pros and cons of the collection/analysis methods were summarised. Then, pertinent publications were mapped into the flood modelling cycle, considering how citizen data properties (spatial and temporal coverage, uncertainty and volume) are related to its integration into modelling. It was clear that the number of studies in the area is rising. There are positive experiences reported in collection and analysis methods, for instance with velocity and land cover, and also when modelling is concerned, for example by using social media mining. However, matching the data properties necessary for each part of the modelling cycle with citizen-generated data is still challenging. Nevertheless, the concept that citizen contributions can be used for simulation and forecasting is proved and further work lies in continuing to develop and improve not only methods for collection and analysis, but certainly for integration into models as well. Finally, in view of recent automated sensors and satellite technologies, it is through studies as the ones analysed in this article that the value of citizen contributions, complementing such technologies, is demonstrated.

  17. Intraarterial reteplase and intravenous abciximab for treatment of acute ischemic stroke. A preliminary feasibility and safety study in a non-human primate model

    International Nuclear Information System (INIS)

    Qureshi, Adnan I.; Suri, M. Fareed K.; Ali, Zulfiqar; Ringer, Andrew J.; Boulos, Alan S.; Guterman, Lee R.; Hopkins, L. Nelson; Nakada, Marian T.; Alberico, Ronald A.; Martin, Lisa B.E.

    2005-01-01

    We performed a preliminary feasibility and safety study using intravenous (IV) administration of a platelet glycoprotein IIb/IIIa inhibitor (abciximab) in conjunction with intraarterial (IA) administration of a thrombolytic agent (reteplase) in a primate model of intracranial thrombosis. We introduced thrombus through superselective catheterization of the intracranial segment of the internal carotid artery in 16 primates. The animals were randomly assigned to receive IA reteplase and IV abciximab (n =4), IA reteplase and IV placebo (n =4), IA placebo and IV abciximab (n =4) or IA and IV placebo (n =4). Recanalization was assessed by serial angiography during the 6-h period after initiation of treatment. Postmortem magnetic resonance (MR) imaging was performed to determine the presence of cerebral infarction or intracranial hemorrhage. Partial or complete recanalization at 6 h after initiation of treatment (decrease of two or more points in pre-treatment angiographic occlusion grade) was observed in two animals treated with IA reteplase and IV abciximab, three animals treated with IA reteplase alone and one animal treated with IV abciximab alone. No improvement in perfusion was observed in animals that received IV and IA placebo. Cerebral infarction was demonstrated on postmortem MR imaging in three animals that received IA and IV placebo and in one animal each from the groups that received IA reteplase and IV abciximab or IV abciximab alone. One animal that received IV abciximab alone had a small intracerebral hemorrhage on MR imaging. (orig.)

  18. MATLAB-implemented estimation procedure for model-based assessment of hepatic insulin degradation from standard intravenous glucose tolerance test data.

    Science.gov (United States)

    Di Nardo, Francesco; Mengoni, Michele; Morettini, Micaela

    2013-05-01

    Present study provides a novel MATLAB-based parameter estimation procedure for individual assessment of hepatic insulin degradation (HID) process from standard frequently-sampled intravenous glucose tolerance test (FSIGTT) data. Direct access to the source code, offered by MATLAB, enabled us to design an optimization procedure based on the alternating use of Gauss-Newton's and Levenberg-Marquardt's algorithms, which assures the full convergence of the process and the containment of computational time. Reliability was tested by direct comparison with the application, in eighteen non-diabetic subjects, of well-known kinetic analysis software package SAAM II, and by application on different data. Agreement between MATLAB and SAAM II was warranted by intraclass correlation coefficients ≥0.73; no significant differences between corresponding mean parameter estimates and prediction of HID rate; and consistent residual analysis. Moreover, MATLAB optimization procedure resulted in a significant 51% reduction of CV% for the worst-estimated parameter by SAAM II and in maintaining all model-parameter CV% MATLAB-based procedure was suggested as a suitable tool for the individual assessment of HID process. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  19. Acute administration of ginger (Zingiber officinale rhizomes) extract on timed intravenous pentylenetetrazol infusion seizure model in mice.

    Science.gov (United States)

    Hosseini, Abdolkarim; Mirazi, Naser

    2014-03-01

    Zingiber officinale (Zingiberaceae) or ginger, which is used in traditional medicine has antioxidant activity and neuroprotective effects. The effects of this plant on clonic seizure have not yet been studied. The present study evaluated the anticonvulsant effect of ginger in a model of clonic seizures induced with pentylenetetrazole (PTZ) in male mice. The anticonvulsant effect of Z. officinale was investigated using i.v. PTZ-induced seizure models in mice. Different doses of the hydroethanolic extract of Z. officinale (25, 50, and 100mg/kg) were administered intraperitonal (i.p.), 2 and 24h before induction of PTZ. Phenobarbital sodium (30mg/kg), a reference standard, was also tested for comparison. The effect of ginger on to the appearance of three separate seizure endpoints (myoclonic, generalized clonus and forelimb tonic extension phase) was recorded. The results showed that the ginger extract has anticonvulsant effects in all the experimental treatment groups of seizure tested as it significantly increased the seizure threshold. Hydroethanolic extract of Z. officinale significantly increased the onset time of myoclonic seizure at doses of 25-100mg/kg (p<0.001) and significantly prevented generalized clonic (p<0.001) and increased the threshold for the forelimb tonic extension (p<0.01) seizure 2 and 24h before induction of PTZ compared with control group. Based on the results the hydroethanolic extract of ginger has anticonvulsant effects, possibly through an interaction with inhibitory and excitatory system, antioxidant mechanisms, oxidative stress and calcium channel inhibition. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Undergraduate students’ challenges with computational modelling in physics

    Directory of Open Access Journals (Sweden)

    Simen A. Sørby

    2012-12-01

    Full Text Available In later years, computational perspectives have become essential parts in several of the University of Oslo’s natural science studies. In this paper we discuss some main findings from a qualitative study of the computational perspectives’ impact on the students’ work with their first course in physics– mechanics – and their learning and meaning making of its contents. Discussions of the students’ learning of physics are based on sociocultural theory, which originates in Vygotsky and Bakhtin, and subsequent physics education research. Results imply that the greatest challenge for students when working with computational assignments is to combine knowledge from previously known, but separate contexts. Integrating knowledge of informatics, numerical and analytical mathematics and conceptual understanding of physics appears as a clear challenge for the students. We also observe alack of awareness concerning the limitations of physical modelling. The students need help with identifying the appropriate knowledge system or “tool set”, for the different tasks at hand; they need helpto create a plan for their modelling and to become aware of its limits. In light of this, we propose thatan instructive and dialogic text as basis for the exercises, in which the emphasis is on specification, clarification and elaboration, would be of potential great aid for students who are new to computational modelling.

  1. Models of marine molluscan diseases: Trends and challenges.

    Science.gov (United States)

    Powell, Eric N; Hofmann, Eileen E

    2015-10-01

    Disease effects on host population dynamics and the transmission of pathogens between hosts are two important challenges for understanding how epizootics wax and wane and how disease influences host population dynamics. For the management of marine shellfish resources, marine diseases pose additional challenges in early intervention after the appearance of disease, management of the diseased population to limit a decline in host abundance, and application of measures to restrain that decline once it occurs. Mathematical models provide one approach for quantifying these effects and addressing the competing goals of managing the diseased population versus managing the disease. The majority of models for molluscan diseases fall into three categories distinguished by these competing goals. (1) Models that consider disease effects on the host population tend to focus on pathogen proliferation within the host. Many of the well-known molluscan diseases are pandemic, in that they routinely reach high prevalence rapidly over large geographic expanses, are characterized by transmission that does not depend upon a local source, and exert a significant influence on host population dynamics. Models focused on disease proliferation examine the influence of environmental change on host population metrics and provide a basis to better manage diseased stocks. Such models are readily adapted to questions of fishery management and habitat restoration. (2) Transmission models are designed to understand the mechanisms triggering epizootics, identify factors impeding epizootic development, and evaluate controls on the rate of disease spread over the host's range. Transmission models have been used extensively to study terrestrial diseases, yet little attention has been given to their potential for understanding the epidemiology of marine molluscan diseases. For management of diseases of wild stocks, transmission models open up a range of options, including the application of area

  2. Revised Starling equation and the glycocalyx model of transvascular fluid exchange: an improved paradigm for prescribing intravenous fluid therapy.

    Science.gov (United States)

    Woodcock, T E; Woodcock, T M

    2012-03-01

    I.V. fluid therapy does not result in the extracellular volume distribution expected from Starling's original model of semi-permeable capillaries subject to hydrostatic and oncotic pressure gradients within the extracellular fluid. Fluid therapy to support the circulation relies on applying a physiological paradigm that better explains clinical and research observations. The revised Starling equation based on recent research considers the contributions of the endothelial glycocalyx layer (EGL), the endothelial basement membrane, and the extracellular matrix. The characteristics of capillaries in various tissues are reviewed and some clinical corollaries considered. The oncotic pressure difference across the EGL opposes, but does not reverse, the filtration rate (the 'no absorption' rule) and is an important feature of the revised paradigm and highlights the limitations of attempting to prevent or treat oedema by transfusing colloids. Filtered fluid returns to the circulation as lymph. The EGL excludes larger molecules and occupies a substantial volume of the intravascular space and therefore requires a new interpretation of dilution studies of blood volume and the speculation that protection or restoration of the EGL might be an important therapeutic goal. An explanation for the phenomenon of context sensitivity of fluid volume kinetics is offered, and the proposal that crystalloid resuscitation from low capillary pressures is rational. Any potential advantage of plasma or plasma substitutes over crystalloids for volume expansion only manifests itself at higher capillary pressures.

  3. European Continental Scale Hydrological Model, Limitations and Challenges

    Science.gov (United States)

    Rouholahnejad, E.; Abbaspour, K.

    2014-12-01

    The pressures on water resources due to increasing levels of societal demand, increasing conflict of interest and uncertainties with regard to freshwater availability create challenges for water managers and policymakers in many parts of Europe. At the same time, climate change adds a new level of pressure and uncertainty with regard to freshwater supplies. On the other hand, the small-scale sectoral structure of water management is now reaching its limits. The integrated management of water in basins requires a new level of consideration where water bodies are to be viewed in the context of the whole river system and managed as a unit within their basins. In this research we present the limitations and challenges of modelling the hydrology of the continent Europe. The challenges include: data availability at continental scale and the use of globally available data, streamgauge data quality and their misleading impacts on model calibration, calibration of large-scale distributed model, uncertainty quantification, and computation time. We describe how to avoid over parameterization in calibration process and introduce a parallel processing scheme to overcome high computation time. We used Soil and Water Assessment Tool (SWAT) program as an integrated hydrology and crop growth simulator to model water resources of the Europe continent. Different components of water resources are simulated and crop yield and water quality are considered at the Hydrological Response Unit (HRU) level. The water resources are quantified at subbasin level with monthly time intervals for the period of 1970-2006. The use of a large-scale, high-resolution water resources models enables consistent and comprehensive examination of integrated system behavior through physically-based, data-driven simulation and provides the overall picture of water resources temporal and spatial distribution across the continent. The calibrated model and results provide information support to the European Water

  4. Challenges of model transferability to data-scarce regions (Invited)

    Science.gov (United States)

    Samaniego, L. E.

    2013-12-01

    Developing the ability to globally predict the movement of water on the land surface at spatial scales from 1 to 5 km constitute one of grand challenges in land surface modelling. Copying with this grand challenge implies that land surface models (LSM) should be able to make reliable predictions across locations and/or scales other than those used for parameter estimation. In addition to that, data scarcity and quality impose further difficulties in attaining reliable predictions of water and energy fluxes at the scales of interest. Current computational limitations impose also seriously limitations to exhaustively investigate the parameter space of LSM over large domains (e.g. greater than half a million square kilometers). Addressing these challenges require holistic approaches that integrate the best techniques available for parameter estimation, field measurements and remotely sensed data at their native resolutions. An attempt to systematically address these issues is the multiscale parameterisation technique (MPR) that links high resolution land surface characteristics with effective model parameters. This technique requires a number of pedo-transfer functions and a much fewer global parameters (i.e. coefficients) to be inferred by calibration in gauged basins. The key advantage of this technique is the quasi-scale independence of the global parameters which enables to estimate global parameters at coarser spatial resolutions and then to transfer them to (ungauged) areas and scales of interest. In this study we show the ability of this technique to reproduce the observed water fluxes and states over a wide range of climate and land surface conditions ranging from humid to semiarid and from sparse to dense forested regions. Results of transferability of global model parameters in space (from humid to semi-arid basins) and across scales (from coarser to finer) clearly indicate the robustness of this technique. Simulations with coarse data sets (e.g. EOBS

  5. A 6-month mixed-effect pharmacokinetic model for post-transplant intravenous anti-hepatitis B immunoglobulin prophylaxis

    Directory of Open Access Journals (Sweden)

    Han S

    2017-07-01

    Full Text Available Seunghoon Han,1,2 Gun Hyung Na,3 Dong-Goo Kim3 1Department of Pharmacology, College of Medicine, The Catholic University of Korea, Seocho-gu, Seoul, South Korea; 2Pharmacometrics Institute for Practical Education and Training, The Catholic University of Korea, Seocho-gu, Seoul, South Korea; 3Department of Surgery, Seoul St Mary’s Hospital, The Catholic University of Korea, Seocho-gu, Seoul, South Korea Background: Although individualized dosage regimens for anti-hepatitis B immunoglobulin (HBIG therapy have been suggested, the pharmacokinetic profile and factors influencing the basis for individualization have not been sufficiently assessed. We sought to evaluate the pharmacokinetic characteristics of anti-HBIG quantitatively during the first 6 months after liver transplantation. Methods: Identical doses of 10,000 IU HBIG were administered to adult liver transplant recipients daily during the first week, weekly thereafter until 28 postoperative days, and monthly thereafter. Blood samples were obtained at days 1, 7, 28, 84, and 168 after transplantation. Plasma HBIG titer was quantified using 4 different immunoassay methods. The titer determined by each analytical method was used for mixed-effect modeling, and the most precise results were chosen. Simulations were performed to predict the plausible immunoglobulin maintenance dose. Results: HBIG was eliminated from the body most rapidly in the immediate post-transplant period, and the elimination rate gradually decreased thereafter. In the early post-transplant period, patients with higher DNA titer tend to have lower plasma HBIG concentrations. The maintenance doses required to attain targets in 90%, 95%, and 99% of patients were ~15.3, 18.2, and 25.1 IU, respectively, multiplied by the target trough level (in IU/L. Conclusion: The variability (explained and unexplained in HBIG pharmacokinetics was relatively larger in the early post-transplant period. Dose individualization based upon

  6. Intravenous injection of artificial red cells and subsequent dye laser irradiation causes deep vessel impairment in an animal model of port-wine stain.

    Science.gov (United States)

    Rikihisa, Naoaki; Tominaga, Mai; Watanabe, Shoji; Mitsukawa, Nobuyuki; Saito, Yoshiaki; Sakai, Hiromi

    2018-03-15

    Our previous study proposed using artificial blood cells (hemoglobin vesicles, Hb-Vs) as photosensitizers in dye laser treatment for port-wine stains (PWSs). Dye laser photons are absorbed by red blood cells (RBCs) and hemoglobin (Hb) mixture, which potentially produce more heat and photocoagulation and effectively destroy endothelial cells. Hb-Vs combination therapy will improve clinical outcomes of dye laser treatment for PWSs because very small vessels do not contain sufficient RBCs and they are poor absorbers/heaters of lasers. In the present study, we analyzed the relationship between vessel depth from the skin surface and vessel distraction through dye laser irradiation following intravenous Hb-Vs injection using a chicken wattle model. Hb-Vs were administered and chicken wattles underwent high-energy irradiation at energy higher than in the previous experiments. Hb-Vs location in the vessel lumen was identified to explain its photosensitizer effect using human Hb immunostaining of the irradiated wattles. Laser irradiation with Hb-Vs can effectively destroy deep vessels in animal models. Hb-Vs tend to flow in the marginal zone of both small and large vessels. Increasing laser power combined with Hb-Vs injection contributed for deep vessel impairment because of the synergetic effect of both methods. Newly added Hb tended to flow near the target endothelial cells of the laser treatment. In Hb-Vs and RBC mixture, heat transfer to endothelial cells from absorbers/heater may increase. Hb-Vs function as photosensitizers to destroy deep vessels within a restricted distance that the photon can reach.

  7. Modeling and Analysis in Marine Big Data: Advances and Challenges

    Directory of Open Access Journals (Sweden)

    Dongmei Huang

    2015-01-01

    Full Text Available It is aware that big data has gathered tremendous attentions from academic research institutes, governments, and enterprises in all aspects of information sciences. With the development of diversity of marine data acquisition techniques, marine data grow exponentially in last decade, which forms marine big data. As an innovation, marine big data is a double-edged sword. On the one hand, there are many potential and highly useful values hidden in the huge volume of marine data, which is widely used in marine-related fields, such as tsunami and red-tide warning, prevention, and forecasting, disaster inversion, and visualization modeling after disasters. There is no doubt that the future competitions in marine sciences and technologies will surely converge into the marine data explorations. On the other hand, marine big data also brings about many new challenges in data management, such as the difficulties in data capture, storage, analysis, and applications, as well as data quality control and data security. To highlight theoretical methodologies and practical applications of marine big data, this paper illustrates a broad view about marine big data and its management, makes a survey on key methods and models, introduces an engineering instance that demonstrates the management architecture, and discusses the existing challenges.

  8. Challenge models for RTFS in rainbow trout fry (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Henriksen, Maya Maria Mihályi; Madsen, Lone; Dalsgaard, Inger

    2011-01-01

    forms of stress have shown to be reproducible. Bath challenge is more appropriate for vaccine testing, since natural transmission of infection is imitated and is also more suitable due to the small size of the fry. A bath-model using H2O2 as a stressor is currently being tested on 1.4g rainbow trout fry...... in four experimental groups: 1) no H2O2/no bath infection, 2) H2O2/no bath infection, 3) no H2O2/ bath infection and 4) H2O2/ bath infection. Mortality will be evaluated over approximately 25 days. The project is currently in its preliminary phase and presently focused on development of a model...

  9. Challenges in LCA modelling of multiple loops for aluminium cans

    DEFF Research Database (Denmark)

    Niero, Monia; Olsen, Stig Irving

    considered the case of closed-loop recycling for aluminium cans, where body and lid are different alloys, and discussed the abovementioned challenge. The Life Cycle Inventory (LCI) modelling of aluminium processes is traditionally based on a pure aluminium flow, therefore neglecting the presence of alloying...... elements. We included the effect of alloying elements on the LCA modelling of aluminium can recycling. First, we performed a mass balance of the main alloying elements (Mn, Fe, Si, Cu) in aluminium can recycling at increasing levels of recycling rate. The analysis distinguished between different aluminium...... packaging scrap sources (i.e. used beverage can and mixed aluminium packaging) to understand the limiting factors for multiple loop aluminium can recycling. Secondly, we performed a comparative LCA of aluminium can production and recycling in multiple loops considering the two aluminium packaging scrap...

  10. Challenges to the standard model of Big Bang nucleosynthesis

    International Nuclear Information System (INIS)

    Steigman, G.

    1993-01-01

    Big Bang nucleosynthesis provides a unique probe of the early evolution of the Universe and a crucial test of the consistency of the standard hot Big Bang cosmological model. Although the primordial abundances of 2 H, 3 He, 4 He, and 7 Li inferred from current observational data are in agreement with those predicted by Big Bang nucleosynthesis, recent analysis has severely restricted the consistent range for the nucleon-to-photon ratio: 3.7 ≤ η 10 ≤ 4.0. Increased accuracy in the estimate of primordial 4 he and observations of Be and B in Pop II stars are offering new challenges to the standard model and suggest that no new light particles may be allowed (N ν BBN ≤ 3.0, where N ν is the number of equivalent light neutrinos). 23 refs

  11. MODELLING CHALLENGES TO FORECAST URBAN GOODS DEMAND FOR RAIL

    Directory of Open Access Journals (Sweden)

    Antonio COMI

    2015-12-01

    Full Text Available This paper explores the new research challenges for forecasting urban goods demand by rail. In fact, the growing interest to find urban logistics solutions for improving city sustainability and liveability, mainly due to the reduction of urban road accessibility and environmental constraints, has pushed to explore solutions alternative to the road. Multimodal urban logistics, based on the use of railway, seem an interesting alternative solution, but it remained mainly at conceptual level. Few studies have explored the factors, that push actors to find competitive such a system with respect to the road, and modelling framework for forecasting the relative demand. Therefore, paper reviews the current literature, investigates the factors involved in choosing such a mode, and finally, recalls a recent modelling framework and hence proposes some advancements that allow to point out the rail transport alternative.

  12. Challenges of Modeling Flood Risk at Large Scales

    Science.gov (United States)

    Guin, J.; Simic, M.; Rowe, J.

    2009-04-01

    Flood risk management is a major concern for many nations and for the insurance sector in places where this peril is insured. A prerequisite for risk management, whether in the public sector or in the private sector is an accurate estimation of the risk. Mitigation measures and traditional flood management techniques are most successful when the problem is viewed at a large regional scale such that all inter-dependencies in a river network are well understood. From an insurance perspective the jury is still out there on whether flood is an insurable peril. However, with advances in modeling techniques and computer power it is possible to develop models that allow proper risk quantification at the scale suitable for a viable insurance market for flood peril. In order to serve the insurance market a model has to be event-simulation based and has to provide financial risk estimation that forms the basis for risk pricing, risk transfer and risk management at all levels of insurance industry at large. In short, for a collection of properties, henceforth referred to as a portfolio, the critical output of the model is an annual probability distribution of economic losses from a single flood occurrence (flood event) or from an aggregation of all events in any given year. In this paper, the challenges of developing such a model are discussed in the context of Great Britain for which a model has been developed. The model comprises of several, physically motivated components so that the primary attributes of the phenomenon are accounted for. The first component, the rainfall generator simulates a continuous series of rainfall events in space and time over thousands of years, which are physically realistic while maintaining the statistical properties of rainfall at all locations over the model domain. A physically based runoff generation module feeds all the rivers in Great Britain, whose total length of stream links amounts to about 60,000 km. A dynamical flow routing

  13. Intravenous versus oral etoposide

    DEFF Research Database (Denmark)

    Ali, Abir Salwa; Grönberg, Malin; Langer, Seppo W.

    2018-01-01

    High-grade gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs, G3) are aggressive cancers of the digestive system with poor prognosis and survival. Platinum-based chemotherapy (cisplatin/carboplatin + etoposide) is considered the first-line palliative treatment. Etoposide is frequently...... administered intravenously; however, oral etoposide may be used as an alternative. Concerns for oral etoposide include decreased bioavailability, inter- and intra-patient variability and patient compliance. We aimed to evaluate possible differences in progression-free survival (PFS) and overall survival (OS......) in patients treated with oral etoposide compared to etoposide given as infusion. Patients (n = 236) from the Nordic NEC study were divided into three groups receiving etoposide as a long infusion (24 h, n = 170), short infusion (≤ 5 h, n = 33) or oral etoposide (n = 33) according to hospital tradition. PFS...

  14. Engraftment Efficiency after Intra-Bone Marrow versus Intravenous Transplantation of Bone Marrow Cells in a Canine Nonmyeloablative Dog Leukocyte Antigen-Identical Transplantation Model.

    Science.gov (United States)

    Lange, Sandra; Steder, Anne; Killian, Doreen; Knuebel, Gudrun; Sekora, Anett; Vogel, Heike; Lindner, Iris; Dunkelmann, Simone; Prall, Friedrich; Murua Escobar, Hugo; Freund, Mathias; Junghanss, Christian

    2017-02-01

    An intra-bone marrow (IBM) hematopoietic stem cell transplantation (HSCT) is assumed to optimize the homing process and therefore to improve engraftment as well as hematopoietic recovery compared with conventional i.v. HSCT. This study investigated the feasibility and efficacy of IBM HSCT after nonmyeloablative conditioning in an allogeneic canine HSCT model. Two study cohorts received IBM HSCT of either density gradient (IBM-I, n = 7) or buffy coat (IBM-II, n = 6) enriched bone marrow cells. An historical i.v. HSCT cohort served as control. Before allogeneic HSCT experiments were performed, we investigated the feasibility of IBM HSCT by using technetium-99m marked autologous grafts. Scintigraphic analyses confirmed that most IBM-injected autologous cells remained at the injection sites, independent of the applied volume. In addition, cell migration to other bones occurred. The enrichment process led to different allogeneic graft volumes (IBM-I, 2 × 5 mL; IBM-II, 2 × 25 mL) and significantly lower counts of total nucleated cells in IBM-I grafts compared with IBM-II grafts (1.6 × 10 8 /kg versus 3.8 × 10 8 /kg). After allogeneic HSCT, dogs of the IBM-I group showed a delayed engraftment with lower levels of donor chimerism when compared with IBM-II or to i.v. HSCT. Dogs of the IBM-II group tended to reveal slightly faster early leukocyte engraftment kinetics than intravenously transplanted animals. However, thrombocytopenia was significantly prolonged in both IBM groups when compared with i.v. HSCT. In conclusion, IBM HSCT is feasible in a nonmyeloablative HSCT setting but failed to significantly improve engraftment kinetics and hematopoietic recovery in comparison with conventional i.v. HSCT. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  15. Continuous total intravenous anesthesia, using propofol and fentanyl in an open-thorax rabbit model: evaluation of cardiac contractile function and biochemical assessment

    NARCIS (Netherlands)

    de Mulder, P. A.; van Kerckhoven, R. J.; Adriaensen, H. F.; Gillebert, T. C.; de Hert, S. G.

    1997-01-01

    Effects are reported of an anesthetic protocol involving use of predetermined intravenous (i.v.)-administered drug doses during acute experimental procedures in vagotomized, New Zealand White rabbits with open thorax (n = 20) in a nonsurvival study. After induction of anesthesia by intramuscular

  16. A comparison in therapeutic efficacy of several time points of intravenous StemBell administration in a rat model of acute myocardial infarction

    NARCIS (Netherlands)

    Emmens, Reindert W.; Oedayrajsingh-Varma, Maikel; Woudstra, Linde; Kamp, Otto; Meinster, Elisa; van Dijk, Annemieke; Helder, Marco N.; Wouters, Diana; Zeerleder, Sacha; van Ham, S. Marieke; de Jong, Nico; Niessen, Hans W. M.; Juffermans, Lynda J. M.; Krijnen, Paul A. J.

    2017-01-01

    Adipose-derived stromal cells (ASCs) are a promising new therapeutic option for patients with acute myocardial infarction (AMI). Previously, we found that ASCs coupled to antibody-targeted microbubbles (StemBells [StBs]) improved cardiac function when administered intravenously 7 days post-AMI in

  17. Intravenous infusion of docosahexaenoic acid increases serum concentrations in a dose-dependent manner and increases seizure latency in the maximal PTZ model.

    Science.gov (United States)

    Trépanier, Marc-Olivier; Kwong, Kei-Man; Domenichiello, Anthony F; Chen, Chuck T; Bazinet, Richard P; Burnham, W M

    2015-09-01

    Docosahexaenoic acid (DHA) is an omega-3 polyunsaturated fatty acid (n-3 PUFA) that has been shown to raise seizure thresholds in the maximal pentylenetetrazole model following acute subcutaneous (s.c.) administration in rats. Following s.c. administration, however, the dose-response relationship for DHA has shown an inverted U-pattern. The purposes of the present experiment were as follows: (1) to determine the pattern of serum unesterified concentrations resulting from the intravenous (i.v.) infusions of various doses of DHA, (2) to determine the time course of these concentrations following the discontinuation of the infusions, and (3) to determine whether seizure protection in the maximal PTZ model would correlate with serum unesterified DHA levels. Animals received 5-minute i.v. infusions of saline or 25, 50, 100, or 200mg/kg of DHA via a cannula inserted into one of the tail veins. Blood was collected during and after the infusions by means of a second cannula inserted into the other tail vein (Experiment 1). A separate group of animals received saline or 12.5-, 25-, 50-, 100-, or 200 mg/kg DHA i.v. via a cannula inserted into one of the tail veins and were then seizure-tested in the maximal PTZ model either during infusion or after the discontinuation of the infusions. Slow infusions of DHA increased serum unesterified DHA concentrations in a dose-dependent manner, with the 200-mg/kg dose increasing the concentration approximately 260-fold compared with saline-infused animals. Following discontinuation of the infusions, serum concentrations rapidly dropped toward baseline, with half-lives of approximately 40 and 11s for the 25-mg/kg dose and 100-mg/kg dose, respectively. In the seizure-tested animals, DHA significantly increased latency to seizure onset in a dose-dependent manner. Following the discontinuation of infusion, seizure latency rapidly decreased toward baseline. Overall, our study suggests that i.v. infusion of unesterified DHA results in

  18. Challenges of Microgrids in Remote Communities: A STEEP Model Application

    Directory of Open Access Journals (Sweden)

    Daniel Akinyele

    2018-02-01

    Full Text Available There is a growing interest in the application of microgrids around the world because of their potential for achieving a flexible, reliable, efficient and smart electrical grid system and supplying energy to off-grid communities, including their economic benefits. Several research studies have examined the application issues of microgrids. However, a lack of in-depth considerations for the enabling planning conditions has been identified as a major reason why microgrids fail in several off-grid communities. This development requires research efforts that consider better strategies and framework for sustainable microgrids in remote communities. This paper first presents a comprehensive review of microgrid technologies and their applications. It then proposes the STEEP model to examine critically the failure factors based on the social, technical, economic, environmental and policy (STEEP perspectives. The model details the key dimensions and actions necessary for addressing the challenge of microgrid failure in remote communities. The study uses remote communities within Nigeria, West Africa, as case studies and demonstrates the need for the STEEP approach for better understanding of microgrid planning and development. Better insights into microgrid systems are expected to address the drawbacks and improve the situation that can lead to widespread and sustainable applications in off-grid communities around the world in the future. The paper introduces the sustainable planning framework (SPF based on the STEEP model, which can form a general basis for planning microgrids in any remote location.

  19. Ensemble models on palaeoclimate to predict India's groundwater challenge

    Directory of Open Access Journals (Sweden)

    Partha Sarathi Datta

    2013-09-01

    Full Text Available In many parts of the world, freshwater crisis is largely due to increasing water consumption and pollution by rapidly growing population and aspirations for economic development, but, ascribed usually to the climate. However, limited understanding and knowledge gaps in the factors controlling climate and uncertainties in the climate models are unable to assess the probable impacts on water availability in tropical regions. In this context, review of ensemble models on δ18O and δD in rainfall and groundwater, 3H- and 14C- ages of groundwater and 14C- age of lakes sediments helped to reconstruct palaeoclimate and long-term recharge in the North-west India; and predict future groundwater challenge. The annual mean temperature trend indicates both warming/cooling in different parts of India in the past and during 1901–2010. Neither the GCMs (Global Climate Models nor the observational record indicates any significant change/increase in temperature and rainfall over the last century, and climate change during the last 1200 yrs BP. In much of the North-West region, deep groundwater renewal occurred from past humid climate, and shallow groundwater renewal from limited modern recharge over the past decades. To make water management to be more responsive to climate change, the gaps in the science of climate change need to be bridged.

  20. Challenge

    International Nuclear Information System (INIS)

    Schwitters, R.F.

    1996-01-01

    The design of new and upgrades of existing high energy particle accelerators is reviewed in light of the current knowledge of the standard model determined from existing and past machines and funding factors. Current financing of science will delay determining unknowns, such as CP violation, proton decay, neutrino properties, and dark matter. Three options are given: (1) obtain more funding, (2) downsize scientific personnel as are private enterprises or (3) develop new technology which will reduce the high cost of building current designs of high energy accelerators. (AIP) copyright 1996 American Institute of Physics

  1. Challenges of citizen science contributions to modelling hydrodynamics of floods

    Science.gov (United States)

    Assumpção, Thaine Herman; Popescu, Ioana; Jonoski, Andreja; Solomatine, Dimitri P.

    2017-04-01

    Citizen science is an established mechanism in many fields of science, including ecology, biology and astronomy. Citizen participation ranges from collecting and interpreting data towards designing experiments with scientists and cooperating with water management authorities. In the environmental sciences, its potential has begun to be explored in the past decades and many studies on the applicability to water resources have emerged. Citizen Observatories are at the core of several EU-funded projects such as WeSenseIt, GroundTruth, GroundTruth 2.0 and SCENT (Smart Toolbox for Engaging Citizens into a People-Centric Observation Web) that already resulted in valuable contributions to the field. Buytaert et al. (2014) has already reviewed the role of citizen science in hydrology. The work presented here aims to complement it, reporting and discussing the use of citizen science for modelling the hydrodynamics of floods in a variety of studies. Additionally, it highlights the challenges that lie ahead to utilize more fully the citizen science potential contribution. In this work, focus is given to each component of hydrodynamic models: water level, velocity, flood extent, roughness and topography. It is addressed how citizens have been contributing to each aspect, mainly considering citizens as sensors and citizens as data interpreters. We consider to which kind of model (1D or 2D) the discussed approaches contribute and what their limitations and potential uses are. We found that although certain mechanisms are well established (e.g. the use of Volunteer Geographic Information for soft validation of land-cover and land-use maps), the applications in a modelling context are rather modest. Also, most studies involving models are limited to replacing traditional data with citizen data. We recommend that citizen science continue to be explored in modelling frameworks, in different case studies, taking advantage of the discussed mechanisms and of new sensor technologies

  2. Challenges and potential solutions for European coastal ocean modelling

    Science.gov (United States)

    She, Jun; Stanev, Emil

    2017-04-01

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

  3. Smart services – characteristics, challenges, opportunities and business models

    Directory of Open Access Journals (Sweden)

    Marquardt Katrin

    2017-07-01

    Full Text Available “Industry 4.0”, “Digitalization”, “Internet of Things” and “Smart Services” are the today’s buzzwords when tracking economic news. It is to ask about the meaning of those phrases. The world has changed over the last decade from a mainly physical to software controlled economy and the information technology has become an integral part of our industry and society in its entirety. Nowadays it is no longer the product that matters it is the data that are generated by using the product or service. Those usage data collected and analyzed commence new business models and services. The economic future of a company will much more rely on the ability to collect and use the data to generate Smart Services for their customers and to transform from a simple product supplier to an entertainment provider. However there are not only opportunities there are also challenges on the way to that new services which needs to be known and considered. For instance the development cycles need to be faster, the business models need to be adjusted and the positive financial results will not come into the picture on the first day. Based on those thoughts and while there only a handful of researches about that new services exists, the main purpose of the present study is at first, to gain a common understanding about the meaning and the characteristics of Smart Services and their adjacencies. Secondly, the study summarizes the identified challenges and opportunities in relation to them. Thirdly, the author introduce and explain the main business models usable for those Smart Services and the requirements for starting the transformation towards those services. The aim of this paper is to set a basis for this exciting and relatively unsought topic and to produce an interest in further empirical and practical researches in this area. The methodologies used for this research are a systematic literature review and an evaluation of existing studies with the

  4. Challenges of 4D(ata Model for Electronic Government

    Directory of Open Access Journals (Sweden)

    Bogdan GHILIC-MICU

    2015-01-01

    Full Text Available Social evolution pyramid, built on the foundation of the ‘90s capitalist society, lead to the emergence of the informational society – years 1990 to 2005 – and knowledge society – years 2005 to 2020. The literature starts using a new concept, a new form of association – artificial intelligence society – foreseen to be established in the next time frame. All these developments of human society and translations or leaps (most of the times apparently timeless were, are and will be possible only due to the advancing information and communications technologies. The leap to Democracy 3.0, based on information and communication technologies prompts to a radical change in the majority of the classical concepts targeting society structure and the way it is guided and controlled. Thus, concepts become electronic concepts (or e-concepts through the use of new technologies. E-concepts keep the essence of the classical principles of liberty and democracy, adding a major aspect of the new way of communication and spreading ideas between people. The main problem is to quantify, analyze and foresee the way technological changes will influence not only the economic system, but also the daily life of the individual and the society. Unfortunately (or maybe fortunately, depending on the point of view, all these evolutions and technological and social developments are as many challenges for the governments of the world. In this paper we will highlight only four of the challenges facing the governments, grouped in a structured model with the following specific concepts: Big Data, Social Data, Linked Data and Mobile Data. This is an emerging paradigm of the information and communication technology supporting national and global eGovernment projects.

  5. Ultrasonography versus intravenous urography

    International Nuclear Information System (INIS)

    Aslaksen, A.

    1991-01-01

    The present study was performed to compare the clinical value of urography and ultrasonography in a non-selected group of patients referred for urography to a university hospital. The conslusions and clinical implications of the study are as follows: Intravenous urography remains the cornerstone imaging examination in the evaluation of ureteral calculi. Ultrasonography is a valuable adjunct in cases of non- visualization of the kidneys, in distal obstruction and known contrast media allergy. When women with recurrent urinary tract infection are referred for imaging of the urinary tract, ultrasonography should be used. Ultrasonography should replace urography for screening of non-acute hydronephrosis like in female genital cancer and benign prostate hyperplasia. There is good correlation between urography and ultrasonography in assessing the degree of hydronephrosis. However, more researh on the relationship between hydronephrosis and obstruction is necessary. Ultrasonography should be used as the only imaging method of the upper urinary tract in patients with microscopic hematuria. In patients less than 50 years with macroscopic hematuria, ultrasonography should be used as the only imaging of the upper urinary tract, and an examination of the urinary bladder should be included. In patients over 50 years, urography supplied with ultrasonography should be used, but more research is necessary on the subject of imaging method and age. 158 refs

  6. Maternal intravenous treatment with either azithromycin or solithromycin clears Ureaplasma parvum from the amniotic fluid in an ovine model of intrauterine infection.

    Science.gov (United States)

    Miura, Yuichiro; Payne, Matthew S; Keelan, Jeffrey A; Noe, Andres; Carter, Sean; Watts, Rory; Spiller, Owen B; Jobe, Alan H; Kallapur, Suhas G; Saito, Masatoshi; Stock, Sarah J; Newnham, John P; Kemp, Matthew W

    2014-09-01

    Intrauterine infection with Ureaplasma spp. is strongly associated with preterm birth and adverse neonatal outcomes. We assessed whether combined intraamniotic (IA) and maternal intravenous (IV) treatment with one of two candidate antibiotics, azithromycin (AZ) or solithromycin (SOLI), would eradicate intrauterine Ureaplasma parvum infection in a sheep model of pregnancy. Sheep with singleton pregnancies received an IA injection of U. parvum serovar 3 at 85 days of gestational age (GA). At 120 days of GA, animals (n=5 to 8/group) received one of the following treatments: (i) maternal IV SOLI with a single IA injection of vehicle (IV SOLI only); (ii) maternal IV SOLI with a single IA injection of SOLI (IV+IA SOLI); (iii) maternal IV AZ and a single IA injection of vehicle (IV AZ only); (iv) maternal IV AZ and a single IA injection of AZ (IV+IA AZ); or (v) maternal IV and single IA injection of vehicle (control). Lambs were surgically delivered at 125 days of GA. Treatment efficacies were assessed by U. parvum culture, quantitative PCR, enzyme-linked immunosorbent assay, and histopathology. Amniotic fluid (AF) from all control animals contained culturable U. parvum. AF, lung, and chorioamnion from all AZ- or SOLI-treated animals (IV only or IV plus IA) were negative for culturable U. parvum. Relative to the results for the control, the levels of expression of interleukin 1β (IL-1β), IL-6, IL-8, and monocyte chemoattractant protein 2 (MCP-2) in fetal skin were significantly decreased in the IV SOLI-only group, the MCP-1 protein concentration in the amniotic fluid was significantly increased in the IV+IA SOLI group, and there was no significant difference in the histological inflammation scoring of lung or chorioamnion among the five groups. In the present study, treatment with either AZ or SOLI (IV only or IV+IA) effectively eradicated macrolide-sensitive U. parvum from the AF. There was no discernible difference in antibiotic therapy efficacy between IV-only and IV

  7. Intravenous Lipids for Preterm Infants: A Review

    Directory of Open Access Journals (Sweden)

    Ghassan S. A. Salama

    2015-01-01

    Full Text Available Extremely low birth weight infants (ELBW are born at a time when the fetus is undergoing rapid intrauterine brain and body growth. Continuation of this growth in the first several weeks postnatally during the time these infants are on ventilator support and receiving critical care is often a challenge. These infants are usually highly stressed and at risk for catabolism. Parenteral nutrition is needed in these infants because most cannot meet the majority of their nutritional needs using the enteral route. Despite adoption of a more aggressive approach with amino acid infusions, there still appears to be a reluctance to use early intravenous lipids. This is based on several dogmas that suggest that lipid infusions may be associated with the development or exacerbation of lung disease, displace bilirubin from albumin, exacerbate sepsis, and cause CNS injury and thrombocytopena. Several recent reviews have focused on intravenous nutrition for premature neonate, but very little exists that provides a comprehensive review of intravenous lipid for very low birth and other critically ill neonates. Here, we would like to provide a brief basic overview, of lipid biochemistry and metabolism of lipids, especially as they pertain to the preterm infant, discuss the origin of some of the current clinical practices, and provide a review of the literature, that can be used as a basis for revising clinical care, and provide some clarity in this controversial area, where clinical care is often based more on tradition and dogma than science.

  8. Effects of intravenous administration of bone marrow stromal stem cells on cognitive impairment of the whole-brain irradiated rat models

    International Nuclear Information System (INIS)

    Ding Weijun; Wang Jianhua; Zhu Min; Chen Baoguo; Wang Yang

    2007-01-01

    Objective: To explore the effect of intravenous infusion of bone marrow stromal stem cells(MSCs) on cognitive function of rats after whole brain irradiation. Methods: MSCs were isolated and cultured from adult rats. After Sprague-Dawly female rats were anaesthetized with chloral hydrate, their whole cerebrum was irradiated with a single dose of 20 Gy by 6 MV X-ray. Seven days after irradiation, 4 x 106 Hoechst33342-1abelled MSCs were intravenously injected into the tail vein of these rats. Four and 8 weeks after transplantation, the learning and memorizing ability was measured with the Y maze test. Immunohistochemical method was used to identify MSCs or ceils derived from MSCs in the brain. Results: The learning and memorizing ability of irradiation groups were significantly different from that of normal control group (P < 0.01). Significant improvement of cognitive impairment was observed in rats treated with MSCs at 4 and 8 weeks after transplantation as compared with the controll groups (P<0.05). This showed that the MSCs survived and were localized to the brain tissue. The number of Hoechst33342 immunohistofluorescence positive cells and double-immunostaining cells significantly decreased in 8 weeks group as compared with the 4 weeks group. Conclusion: Marrow stromal stem cells delivered to the irradiation brain tissue through intravenous route improve the cognitive impairment after whole brain irradiation. These cells may survive and differentiate in the brain tissue of irradiated rats. (authors)

  9. Memory of irrigation effects on hydroclimate and its modeling challenge

    Science.gov (United States)

    Chen, Fei; Xu, Xiaoyu; Barlage, Michael; Rasmussen, Roy; Shen, Shuanghe; Miao, Shiguang; Zhou, Guangsheng

    2018-06-01

    Irrigation modifies land-surface water and energy budgets, and also influences weather and climate. However, current earth-system models, used for weather prediction and climate projection, are still in their infancy stage to consider irrigation effects. This study used long-term data collected from two contrasting (irrigated and rainfed) nearby maize-soybean rotation fields, to study the effects of irrigation memory on local hydroclimate. For a 12 year average, irrigation decreases summer surface-air temperature by less than 1 °C and increases surface humidity by 0.52 g kg‑1. The irrigation cooling effect is more pronounced and longer lasting for maize than for soybean. Irrigation reduces maximum, minimum, and averaged temperature over maize by more than 0.5 °C for the first six days after irrigation, but its temperature effect over soybean is mixed and negligible two or three days after irrigation. Irrigation increases near-surface humidity over maize by about 1 g kg‑1 up to ten days and increases surface humidity over soybean (~ 0.8 g kg‑1) with a similar memory. These differing effects of irrigation memory on temperature and humidity are associated with respective changes in the surface sensible and latent heat fluxes for maize and soybean. These findings highlight great need and challenges for earth-system models to realistically simulate how irrigation effects vary with crop species and with crop growth stages, and to capture complex interactions between agricultural management and water-system components (crop transpiration, precipitation, river, reservoirs, lakes, groundwater, etc.) at various spatial and temporal scales.

  10. Challenges and Opportunities in Modeling of the Global Atmosphere

    Science.gov (United States)

    Janjic, Zavisa; Djurdjevic, Vladimir; Vasic, Ratko

    2016-04-01

    are comparable to the scales of the dominant Rossby waves, such fictitious solutions are hard to identify and remove. Another new challenge on the global scale is that the limit of validity of the hydrostatic approximation is rapidly being approached. Relaxing the hydrostatic approximation requieres careful reformulation of the model dynamics and more computations and communications. The unified Non-hydrostatic Multi-scale Model (NMMB) will be briefly discussed as an example. The non-hydrostatic dynamics were designed in such a way as to avoid over-specification. The global version is run on the latitude-longitude grid, and the polar filter selectively slows down the waves that would otherwise be unstable without modifying their amplitudes. The model has been successfully tested on various scales. The skill of the medium range forecasts produced by the NMMB is comparable to that of other major medium range models, and its computational efficiency on parallel computers is good.

  11. Use of general practice by intravenous heroin users on a methadone programme.

    OpenAIRE

    Leaver, E J; Elford, J; Morris, J K; Cohen, J

    1992-01-01

    Users of intravenous heroin represent a major challenge for general practice. A study was undertaken in a general practice in central London in 1990 to investigate the use of general practice made by intravenous heroin users who were on a methadone programme. Using information recorded in the patients' notes, 29 intravenous heroin users on a methadone programme were identified; 58 non-drug users (two controls per case) were matched for age, sex and general practitioner. A study of the number ...

  12. Challenges and opportunities in land surface modelling of savanna ecosystems

    Directory of Open Access Journals (Sweden)

    R. Whitley

    2017-10-01

    Full Text Available The savanna complex is a highly diverse global biome that occurs within the seasonally dry tropical to sub-tropical equatorial latitudes and are structurally and functionally distinct from grasslands and forests. Savannas are open-canopy environments that encompass a broad demographic continuum, often characterised by a changing dominance between C3-tree and C4-grass vegetation, where frequent environmental disturbances such as fire modulates the balance between ephemeral and perennial life forms. Climate change is projected to result in significant changes to the savanna floristic structure, with increases to woody biomass expected through CO2 fertilisation in mesic savannas and increased tree mortality expected through increased rainfall interannual variability in xeric savannas. The complex interaction between vegetation and climate that occurs in savannas has traditionally challenged terrestrial biosphere models (TBMs, which aim to simulate the interaction between the atmosphere and the land surface to predict responses of vegetation to changing in environmental forcing. In this review, we examine whether TBMs are able to adequately represent savanna fluxes and what implications potential deficiencies may have for climate change projection scenarios that rely on these models. We start by highlighting the defining characteristic traits and behaviours of savannas, how these differ across continents and how this information is (or is not represented in the structural framework of many TBMs. We highlight three dynamic processes that we believe directly affect the water use and productivity of the savanna system: phenology, root-water access and fire dynamics. Following this, we discuss how these processes are represented in many current-generation TBMs and whether they are suitable for simulating savanna fluxes.Finally, we give an overview of how eddy-covariance observations in combination with other data sources can be used in model

  13. Recent European Challenges and the Danish Collective Agreement Model

    DEFF Research Database (Denmark)

    Larsen, Trine Pernille; Navrbjerg, Steen Erik

    are related to the new forms of cross-border collaboration and negotiations taking place within multi-national corporations (MNC's). This research paper examines a series of challenges facing the collective bargaining systems in Denmark, Estonia, Northern Ireland and Sweden. These countries represent four...... distinct labour market systems with different traditions of social dialogue and allow comparison of how different EU member states handled the recent challenges caused by the increased European integration....

  14. Comparison of postinfusion phlebitis in intravenous push versus intravenous piggyback cefazolin.

    Science.gov (United States)

    Biggar, Constance; Nichols, Cynthia

    2012-01-01

    Reducing health care costs without adversely affecting patient safety is a constant challenge for health care institutions. Cefazolin prophylaxis via intravenous push (IVP) is more cost-effective than via intravenous piggyback (IVPB). The purpose of this study was to determine whether patient safety would be compromised (ie, an increased rate of phlebitis) with a change to the IVP method. Rates of phlebitis in orthopedic surgical patients receiving cefazolin prophylaxis via IVP versus IVPB were evaluated in a prospective quasi-experimental design of 240 patients. The first 120 subjects received cefazolin via IVPB, and the second 120 subjects received it via IVP. Results indicated no statistically significant difference in phlebitis rates in the IVPB (3.4%) versus the IVP groups (3.3%).

  15. Why Is Improvement of Earth System Models so Elusive? Challenges and Strategies from Dust Aerosol Modeling

    Science.gov (United States)

    Miller, Ronald L.; Garcia-Pando, Carlos Perez; Perlwitz, Jan; Ginoux, Paul

    2015-01-01

    Past decades have seen an accelerating increase in computing efficiency, while climate models are representing a rapidly widening set of physical processes. Yet simulations of some fundamental aspects of climate like precipitation or aerosol forcing remain highly uncertain and resistant to progress. Dust aerosol modeling of soil particles lofted by wind erosion has seen a similar conflict between increasing model sophistication and remaining uncertainty. Dust aerosols perturb the energy and water cycles by scattering radiation and acting as ice nuclei, while mediating atmospheric chemistry and marine photosynthesis (and thus the carbon cycle). These effects take place across scales from the dimensions of an ice crystal to the planetary-scale circulation that disperses dust far downwind of its parent soil. Representing this range leads to several modeling challenges. Should we limit complexity in our model, which consumes computer resources and inhibits interpretation? How do we decide if a process involving dust is worthy of inclusion within our model? Can we identify a minimal representation of a complex process that is efficient yet retains the physics relevant to climate? Answering these questions about the appropriate degree of representation is guided by model evaluation, which presents several more challenges. How do we proceed if the available observations do not directly constrain our process of interest? (This could result from competing processes that influence the observed variable and obscure the signature of our process of interest.) Examples will be presented from dust modeling, with lessons that might be more broadly applicable. The end result will either be clinical depression or there assuring promise of continued gainful employment as the community confronts these challenges.

  16. Modes of Action of Intravenous Immunoglobulin in Bullous Pemphigoid.

    Science.gov (United States)

    Li, Ning; Culton, Donna; Diaz, Luis A; Liu, Zhi

    2018-06-01

    Bullous pemphigoid is an autoantibody-mediated skin blistering disease. Previous studies revealed that intravenous Ig is therapeutic in animal models of bullous pemphigoid by saturating the IgG-protective receptor FcRn, thereby accelerating degradation of pathogenic IgG. Sasaoka et al. demonstrate that the inhibitory effects of intravenous Ig on bullous pemphigoid are also associated with negative modulation of cytokine production by keratinocytes. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Why Is Improvement of Earth System Models So Elusive? Challenges and Strategies From Dust Aerosol Modeling

    Science.gov (United States)

    Miller, R. L.; Pérez García-Pando, C.; Perlwitz, J. P.; Ginoux, P. A.

    2015-12-01

    Past decades have seen an accelerating increase in computing efficiency,while climate models are representing a rapidly widening set ofphysical processes. Yet simulations of some fundamental aspects ofclimate like precipitation or aerosol forcing remain highly uncertainand resistent to progress. Dust aerosol modeling of soil particleslofted by wind erosion has seen a similar conflict between increasingmodel sophistication and remaining uncertainty. Dust aerosols perturbthe energy and water cycles by scattering radiation and acting as icenuclei, while mediating atmospheric chemistry and marinephotosynthesis (and thus the carbon cycle). These effects take placeacross scales from the dimensions of an ice crystal to theplanetary-scale circulation that disperses dust far downwind of itsparent soil. Representing this range leads to several modelingchallenges. Should we limit complexity in our model, which consumescomputer resources and inhibits interpretation? How do we decide if aprocess involving dust is worthy of inclusion within our model? Canwe identify a minimal representation of a complex process that isefficient yet retains the physics relevant to climate? Answeringthese questions about the appropriate degree of representation isguided by model evaluation, which presents several more challenges.How do we proceed if the available observations do not directlyconstrain our process of interest? (This could result from competingprocesses that influence the observed variable and obscure thesignature of our process of interest.) Examples will be presentedfrom dust modeling, with lessons that might be more broadlyapplicable. The end result will either be clinical depression or thereassuring promise of continued gainful employment as the communityconfronts these challenges.

  18. Orthostatic stability with intravenous levodopa

    Directory of Open Access Journals (Sweden)

    Shan H. Siddiqi

    2015-08-01

    Full Text Available Intravenous levodopa has been used in a multitude of research studies due to its more predictable pharmacokinetics compared to the oral form, which is used frequently as a treatment for Parkinson’s disease (PD. Levodopa is the precursor for dopamine, and intravenous dopamine would strongly affect vascular tone, but peripheral decarboxylase inhibitors are intended to block such effects. Pulse and blood pressure, with orthostatic changes, were recorded before and after intravenous levodopa or placebo—after oral carbidopa—in 13 adults with a chronic tic disorder and 16 tic-free adult control subjects. Levodopa caused no statistically or clinically significant changes in blood pressure or pulse. These data add to previous data that support the safety of i.v. levodopa when given with adequate peripheral inhibition of DOPA decarboxylase.

  19. Practical Strategies for School Counsellor Leadership: The Leadership Challenge Model

    Science.gov (United States)

    Shillingford, Margaret

    2013-01-01

    It is crucial to the progression of the school counselling profession that counsellors-in-training receive the training, knowledge, and practice in leadership that they need to counter systemic challenges that they may face. Effective leadership practices have been shown in research to be instrumental in promoting program delivery success in the…

  20. Using animal models to overcome temporal, spatial and combinatorial challenges in HIV persistence research

    DEFF Research Database (Denmark)

    Denton, Paul W.; Søgaard, Ole Schmeltz; Tolstrup, Martin

    2016-01-01

    Research challenges associated with understanding HIV persistence during antiretroviral therapy can be categorized as temporal, spatial and combinatorial. Temporal research challenges relate to the timing of events during establishment and maintenance of HIV persistence. Spatial research challeng...... for directly addressing these research challenges. The aim of this manuscript is to provide a comprehensive review of these recent translational advances made in animal models of HIV persistence....... will improve our understanding of HIV persistence and move the field closer to achieving eradication of persistent HIV. Given that humanized mice and non-human primate HIV models permit rigorous control of experimental conditions, these models have been used extensively as in vivo research platforms...

  1. Modelling water use in global hydrological models: review, challenges and directions

    Science.gov (United States)

    Bierkens, M. F.; de Graaf, I.; Wada, Y.; Wanders, N.; Van Beek, L. P.

    2017-12-01

    During the late 1980s and early 1990s, awareness of the shortage of global water resources lead to the first detailed global water resources assessments using regional statistics of water use and observations of meteorological and hydrological variables. Shortly thereafter, the first macroscale hydrological models (MHM) appeared. In these models, blue water (i.e., surface water and renewable groundwater) availability was calculated by accumulating runoff over a stream network and comparing it with population densities or with estimated water demand for agriculture, industry and households. In this talk we review the evolution of human impact modelling in global land models with a focus on global water resources, touching upon developments of the last 15 years: i.e. calculating human water scarcity; estimating groundwater depletion; adding dams and reservoirs; fully integrating water use (demand, withdrawal, consumption, return flow) in the hydrology; simulating the effects of land use change. We show example studies for each of these steps. We identify We identify major challenges that hamper the further development of integrated water resources modelling. Examples of these are: 1) simulating reservoir operations; 2) including local infrastructure and redistribution; 3) using the correct allocations rules; 4) projecting future water demand and water use. For each of these challenges we signify promising directions for further research.

  2. Analysis of Challenges for Management Education in India Using Total Interpretive Structural Modelling

    Science.gov (United States)

    Mahajan, Ritika; Agrawal, Rajat; Sharma, Vinay; Nangia, Vinay

    2016-01-01

    Purpose: The purpose of this paper is to identify challenges for management education in India and explain their nature, significance and interrelations using total interpretive structural modelling (TISM), an innovative version of Warfield's interpretive structural modelling (ISM). Design/methodology/approach: The challenges have been drawn from…

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

    African Journals Online (AJOL)

    Chris Wray

    There is a risk within .... Giere (2004) models are generally considered as simple representations of reality ..... morphology, connectivity, bid rent and virtual model room – were developed to ... term integrated planning of education and health.

  4. intravenous infusion of chlorimipramine (anafranil)

    African Journals Online (AJOL)

    the already extensive outpatient facilities at Johannesburg. Hospital as well as the Tara Neuro-Psychiatric Hospital for long-term therapy. Technique of Chlorimipramine Infusion. Initially 1 ampoule of chlorimipramine 25 mg in 250 mg of 5°~ dextrose saline was administered intravenously at the rate of 60 drops per minute.

  5. Establishment of an animal challenge model as a potency assay for an inactivated Enterovirus Type 71 vaccine.

    Science.gov (United States)

    Wang, Kun-Teng; Lin, Shih-Jie; Wang, Hsiu-Chi; Chen, Pin-Chun; Lin, Jiao-Jung; Chiang, Jen-Ron; Chang, Chao-Liang; Shih, Daniel Yang-Chih; Lo, Chi-Fang; Wang, Der-Yuan

    2016-07-01

    Enterovirus 71 (EV71) belongs to the Enterovirus genus of the Picornaviridae family, and its occurrence in Asia is associated with hand-foot-and-mouth disease (HFMD), leading to death in some cases, in young children. An effective EV71 vaccine is therefore urgently needed. In this study, we established a two-step EV71 vaccine potency model. Intraperitoneal injections in 2-day-old suckling mice were used to establish the LD50 of EV71 B4, B5, C2, C4, and C5 subgenotypes. Only C4 caused hind limb paralysis in mice (LD50: 2.62 ± 0.45). EV71 VP1 protein was identified in the brain tissues at histology. In the second phase of the model, 3-week-old female ICR mice received one primary and two boosting i.p. injections of formalin-inactivated EV71 B4 and C4 vaccine. Immunized serum was neutralized in vitro with EV71 C4 and applied to the murine challenge model. The C4 vaccine-immunized serum exhibited the highest protective titre (ED50 = 114.6), while the B4 immunized serum had the weakest protective titre (ED50 = 34.3). Additionally, human plasma and intravenous immunoglobulin displayed significant protection in the neutralization assay. Our results could facilitate candidate EV71 vaccine immunogenicity and efficacy evaluations, and may help establish reference EV71 antisera in the future. Copyright © 2016 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

  6. Modeling urban landscape: New paradigms and challenges in territorial representation

    Directory of Open Access Journals (Sweden)

    Sheyla Aguilar de Santana

    2013-05-01

    Full Text Available This paper aims to give a brief background on the production of urban space considering the social functions of the city, the needs of contemporary urban reforms and the need for tools that assist in decision making. This state of the art about the production space justifies the current studies on the development of geoprocessing tools, techniques and methodologies that attempt the needs of creating interpretive portraits of urban landscapes to facilitate dialogue between urban technical, administrators and community. In this sense, it is presented how GIS has been working within the context of urban planning and appointed the new challenges and paradigms of territorial representation.

  7. Usability and Information access challenges in complex simulation models

    CSIR Research Space (South Africa)

    Naidoo, S

    2008-07-01

    Full Text Available -sensitive help and meaningful feedback when errors occur Legibility Ease with which visual content can be understood Task Completion Whether a user can complete a task within appropriate task time when performing. Minimal action Capability of the software... by the user interface may result in some operations not being visible to the user although available in the simulation tool. The challenge has been to develop simulation tools that can be used by the users with minimal effort required both to operate...

  8. Concepts, challenges, and successes in modeling thermodynamics of metabolism.

    Science.gov (United States)

    Cannon, William R

    2014-01-01

    The modeling of the chemical reactions involved in metabolism is a daunting task. Ideally, the modeling of metabolism would use kinetic simulations, but these simulations require knowledge of the thousands of rate constants involved in the reactions. The measurement of rate constants is very labor intensive, and hence rate constants for most enzymatic reactions are not available. Consequently, constraint-based flux modeling has been the method of choice because it does not require the use of the rate constants of the law of mass action. However, this convenience also limits the predictive power of constraint-based approaches in that the law of mass action is used only as a constraint, making it difficult to predict metabolite levels or energy requirements of pathways. An alternative to both of these approaches is to model metabolism using simulations of states rather than simulations of reactions, in which the state is defined as the set of all metabolite counts or concentrations. While kinetic simulations model reactions based on the likelihood of the reaction derived from the law of mass action, states are modeled based on likelihood ratios of mass action. Both approaches provide information on the energy requirements of metabolic reactions and pathways. However, modeling states rather than reactions has the advantage that the parameters needed to model states (chemical potentials) are much easier to determine than the parameters needed to model reactions (rate constants). Herein, we discuss recent results, assumptions, and issues in using simulations of state to model metabolism.

  9. Progress and challenges in coupled hydrodynamic-ecological estuarine modeling

    Science.gov (United States)

    Ganju, Neil K.; Brush, Mark J.; Rashleigh, Brenda; Aretxabaleta, Alfredo L.; del Barrio, Pilar; Grear, Jason S.; Harris, Lora A.; Lake, Samuel J.; McCardell, Grant; O'Donnell, James; Ralston, David K.; Signell, Richard P.; Testa, Jeremy; Vaudrey, Jamie M. P.

    2016-01-01

    Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review, we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a “theory of everything” for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy.

  10. Bioenergy crop models: Descriptions, data requirements and future challenges

    Energy Technology Data Exchange (ETDEWEB)

    Nair, S. Surendran [University of Tennessee, Knoxville (UTK); Kang, Shujiang [ORNL; Zhang, Xuesong [Pacific Northwest National Laboratory (PNNL); Miguez, Fernando [Iowa State University; Izaurralde, Dr. R. Cesar [Pacific Northwest National Laboratory (PNNL); Post, Wilfred M [ORNL; Dietze, Michael [University of Illinois, Urbana-Champaign; Lynd, L. [Dartmouth College; Wullschleger, Stan D [ORNL

    2012-01-01

    Field studies that address the production of lignocellulosic biomass as a source of renewable energy provide critical data for the development of bioenergy crop models. A literature survey revealed that 14 models have been used for simulating bioenergy crops including herbaceous and woody bioenergy crops, and for crassulacean acid metabolism (CAM) crops. These models simulate field-scale production of biomass for switchgrass (ALMANAC, EPIC, and Agro-BGC), miscanthus (MISCANFOR, MISCANMOD, and WIMOVAC), sugarcane (APSIM, AUSCANE, and CANEGRO), and poplar and willow (SECRETS and 3PG). Two models are adaptations of dynamic global vegetation models and simulate biomass yields of miscanthus and sugarcane at regional scales (Agro-IBIS and LPJmL). Although it lacks the complexity of other bioenergy crop models, the environmental productivity index (EPI) is the only model used to estimate biomass production of CAM (Agave and Opuntia) plants. Except for the EPI model, all models include representations of leaf area dynamics, phenology, radiation interception and utilization, biomass production, and partitioning of biomass to roots and shoots. A few models simulate soil water, nutrient, and carbon cycle dynamics, making them especially useful for assessing the environmental consequences (e.g., erosion and nutrient losses) associated with the large-scale deployment of bioenergy crops. The rapid increase in use of models for energy crop simulation is encouraging; however, detailed information on the influence of climate, soils, and crop management practices on biomass production is scarce. Thus considerable work remains regarding the parameterization and validation of process-based models for bioenergy crops; generation and distribution of high-quality field data for model development and validation; and implementation of an integrated framework for efficient, high-resolution simulations of biomass production for use in planning sustainable bioenergy systems.

  11. Challenges in the development of analytical soil compaction models

    DEFF Research Database (Denmark)

    Keller, Thomas; Lamandé, Mathieu

    2010-01-01

    and recommendations for the prevention of soil compaction often rely on simulation models. This paper highlights some issues that need further consideration in order to improve soil compaction modelling, with the focus on analytical models. We discuss the different issues based on comparisons between experimental......Soil compaction can cause a number of environmental and agronomic problems (e.g. flooding, erosion, leaching of agrochemicals to recipient waters, emission of greenhouse gases to the atmosphere, crop yield losses), resulting in significant economic damage to society and agriculture. Strategies...... data and model simulations. The upper model boundary condition (i.e. contact area and stresses at the tyre-soil interface) is highly influential in stress propagation, but knowledge on the effects of loading and soil conditions on the upper model boundary condition is inadequate. The accuracy of stress...

  12. Rapid de novo shape encoding: a challenge to connectionist modeling

    OpenAIRE

    Greene, Ernest

    2018-01-01

    Neural network (connectionist) models are designed to encode image features and provide the building blocks for object and shape recognition. These models generally call for: a) initial diffuse connections from one neuron population to another, and b) training to bring about a functional change in those connections so that one or more high-tier neurons will selectively respond to a specific shape stimulus. Advanced models provide for translation, size, and rotation invariance. The present dis...

  13. Intravenous Immunoglobulin Protects Against Severe Pandemic Influenza Infection

    Directory of Open Access Journals (Sweden)

    Steven Rockman

    2017-05-01

    Full Text Available Influenza is a highly contagious, acute, febrile respiratory infection that can have fatal consequences particularly in individuals with chronic illnesses. Sporadic reports suggest that intravenous immunoglobulin (IVIg may be efficacious in the influenza setting. We investigated the potential of human IVIg to ameliorate influenza infection in ferrets exposed to either the pandemic H1N1/09 virus (pH1N1 or highly pathogenic avian influenza (H5N1. IVIg administered at the time of influenza virus exposure led to a significant reduction in lung viral load following pH1N1 challenge. In the lethal H5N1 model, the majority of animals given IVIg survived challenge in a dose dependent manner. Protection was also afforded by purified F(ab′2 but not Fc fragments derived from IVIg, supporting a specific antibody-mediated mechanism of protection. We conclude that pre-pandemic IVIg can modulate serious influenza infection-associated mortality and morbidity. IVIg could be useful prophylactically in the event of a pandemic to protect vulnerable population groups and in the critical care setting as a first stage intervention.

  14. Challenges of transferring models of fish abundance between coral reefs.

    Science.gov (United States)

    Sequeira, Ana M M; Mellin, Camille; Lozano-Montes, Hector M; Meeuwig, Jessica J; Vanderklift, Mathew A; Haywood, Michael D E; Babcock, Russell C; Caley, M Julian

    2018-01-01

    Reliable abundance estimates for species are fundamental in ecology, fisheries, and conservation. Consequently, predictive models able to provide reliable estimates for un- or poorly-surveyed locations would prove a valuable tool for management. Based on commonly used environmental and physical predictors, we developed predictive models of total fish abundance and of abundance by fish family for ten representative taxonomic families for the Great Barrier Reef (GBR) using multiple temporal scenarios. We then tested if models developed for the GBR (reference system) could predict fish abundances at Ningaloo Reef (NR; target system), i.e., if these GBR models could be successfully transferred to NR. Models of abundance by fish family resulted in improved performance (e.g., 44.1% fish abundance (9% fish species richness from the GBR to NR, transferability for these fish abundance models was poor. When compared with observations of fish abundance collected in NR, our transferability results had low validation scores ( R 2   0.05). High spatio-temporal variability of patterns in fish abundance at the family and population levels in both reef systems likely affected the transferability of these models. Inclusion of additional predictors with potential direct effects on abundance, such as local fishing effort or topographic complexity, may improve transferability of fish abundance models. However, observations of these local-scale predictors are often not available, and might thereby hinder studies on model transferability and its usefulness for conservation planning and management.

  15. Five challenges for stochastic epidemic models involving global transmission

    Directory of Open Access Journals (Sweden)

    Tom Britton

    2015-03-01

    Full Text Available The most basic stochastic epidemic models are those involving global transmission, meaning that infection rates depend only on the type and state of the individuals involved, and not on their location in the population. Simple as they are, there are still several open problems for such models. For example, when will such an epidemic go extinct and with what probability (questions depending on the population being fixed, changing or growing? How can a model be defined explaining the sometimes observed scenario of frequent mid-sized epidemic outbreaks? How can evolution of the infectious agent transmission rates be modelled and fitted to data in a robust way?

  16. Prediction Models and Decision Support: Chances and Challenges

    NARCIS (Netherlands)

    Kappen, T.H.

    2015-01-01

    A clinical prediction model can assist doctors in arriving at the most likely diagnosis or estimating the prognosis. By utilizing various patient- and disease-related properties, such models can yield objective estimations of the risk of a disease or the probability of a certain disease course for

  17. Five (or so) challenges for species distribution modelling

    DEFF Research Database (Denmark)

    Bastos Araujo, Miguel; Guisan, Antoine

    2006-01-01

    Species distribution modelling is central to both fundamental and applied research in biogeography. Despite widespread use of models, there are still important conceptual ambiguities as well as biotic and algorithmic uncertainties that need to be investigated in order to increase confidence in mo...

  18. The Job Demands?Resources model: Challenges for future research

    NARCIS (Netherlands)

    E. Demerouti (Eva); A.B. Bakke (Arnold B.)

    2011-01-01

    textabstractMotivation: The motivation of this overview is to present the state of the art of Job Demands-Resources (JD-R) model whilst integrating the various contributions to the special issue. Research purpose: To provide an overview of the JD-R model, which incorporates many possible working

  19. The Job Demands-Resources model: challenges for future research

    NARCIS (Netherlands)

    Demerouti, E.; Bakker, A.B.

    2011-01-01

    Motivation: The motivation of this overview is to present the state of the art of Job Demands–Resources (JD–R) model whilst integrating the various contributions to the special issue. Research purpose: To provide an overview of the JD–R model, which incorporates many possible working conditions and

  20. The Job Demands–Resources model: Challenges for future research

    Directory of Open Access Journals (Sweden)

    Evangelia Demerouti

    2011-05-01

    Research purpose: To provide an overview of the JD–R model, which incorporates many possible working conditions and focuses on both negative and positive indicators of employee well-being. Moreover, the studies of the special issue were introduced. Research design: Qualitative and quantitative studies on the JD–R model were reviewed to enlighten the health and motivational processes suggested by the model. Main findings: Next to the confirmation of the two suggested processes of the JD–R model, the studies of the special issue showed that the model can be used to predict work-place bullying, incidences of upper respiratory track infection, work-based identity, and early retirement intentions. Moreover, whilst psychological safety climate could be considered as a hypothetical precursor of job demands and resources, compassion satisfaction moderated the health process of the model. Contribution/value-add: The findings of previous studies and the studies of the special issue were integrated in the JD–R model that can be used to predict well-being and performance at work. New avenues for future research were suggested. Practical/managerial implications: The JD–R model is a framework that can be used for organisations to improve employee health and motivation, whilst simultaneously improving various organisational outcomes.

  1. Challenges in mechanical modeling of SFR fuel rod transient behavior

    Energy Technology Data Exchange (ETDEWEB)

    Feria, F.; Herranz, L. E.

    2013-07-01

    Modeling of SFR fuel rod mechanical behavior under transient conditions entails the development of a creep law to predict cladding viscoplastic strain. In this regard, this work is focused on defining a proper clad creep law structure as the basis to set a suitable model under SFR off-normal conditions as transient overpower and loss of fluid. To do so, a review of in-codes clad creep models has been done by using SAS-SFR, SCANAIR and ASTEC. The proposed creep model has been structured in two parts: viscoplastic behaviour before the failure (primary and secondary creep) and the failure due to viscoplastic collapse (tertiary creep). In order to model the first part, Norton creep law has been proposed as a conservative option. An irradiation hardening factor should be included for best estimate calculations. The recommendation for the second part is to apply a failure criterion based on strain limit or rupture time, which allows achieving conservative results.

  2. Modelling nutritional mutualisms: challenges and opportunities for data integration.

    Science.gov (United States)

    Clark, Teresa J; Friel, Colleen A; Grman, Emily; Shachar-Hill, Yair; Friesen, Maren L

    2017-09-01

    Nutritional mutualisms are ancient, widespread, and profoundly influential in biological communities and ecosystems. Although much is known about these interactions, comprehensive answers to fundamental questions, such as how resource availability and structured interactions influence mutualism persistence, are still lacking. Mathematical modelling of nutritional mutualisms has great potential to facilitate the search for comprehensive answers to these and other fundamental questions by connecting the physiological and genomic underpinnings of mutualisms with ecological and evolutionary processes. In particular, when integrated with empirical data, models enable understanding of underlying mechanisms and generalisation of principles beyond the particulars of a given system. Here, we demonstrate how mathematical models can be integrated with data to address questions of mutualism persistence at four biological scales: cell, individual, population, and community. We highlight select studies where data has been or could be integrated with models to either inform model structure or test model predictions. We also point out opportunities to increase model rigour through tighter integration with data, and describe areas in which data is urgently needed. We focus on plant-microbe systems, for which a wealth of empirical data is available, but the principles and approaches can be generally applied to any nutritional mutualism. © 2017 John Wiley & Sons Ltd/CNRS.

  3. Modeling bladder cancer in mice: opportunities and challenges

    Science.gov (United States)

    Kobayashi, Takashi; Owczarek, Tomasz B.; McKiernan, James M.; Abate-Shen, Cory

    2015-01-01

    The prognosis and treatment of bladder cancer have hardly improved in the last 20 years. Bladder cancer remains a debilitating and often fatal disease, and among the most costly cancers to treat. The generation of informative mouse models has the potential to improve our understanding of bladder cancer progression, as well as impact its diagnosis and treatment. However, relatively few mouse models of bladder cancer have been described and particularly few that develop invasive cancer phenotypes. This review focuses on opportunities for improving the landscape of mouse models of bladder cancer. PMID:25533675

  4. Rising to the challenge : A model of contest performance

    OpenAIRE

    DesAutels, Philip; Berthon, Pierre; Salehi-Sangari, Esmail

    2011-01-01

    Contests are a ubiquitous form of promotion widely adopted by financial services advertisers, yet, paradoxically, academic research on them is conspicuous in its absence. This work addresses this gap by developing a model of contest engagement and performance. Using motivation theory, factors that drive participant engagement are modeled, and engagement's effect on experience and marketing success of the contest specified. Measures of contest performance, in-contest engagement and post-contes...

  5. The Job Demands?Resources model: Challenges for future research

    OpenAIRE

    Demerouti, Eva; Bakke, Arnold B.

    2011-01-01

    textabstractMotivation: The motivation of this overview is to present the state of the art of Job Demands-Resources (JD-R) model whilst integrating the various contributions to the special issue. Research purpose: To provide an overview of the JD-R model, which incorporates many possible working conditions and focuses on both negative and positive indicators of employee well-being. Moreover, the studies of the special issue were introduced. Research design: Qualitative and quantitative studie...

  6. Empirical agent-based modelling challenges and solutions

    CERN Document Server

    Barreteau, Olivier

    2014-01-01

    This instructional book showcases techniques to parameterise human agents in empirical agent-based models (ABM). In doing so, it provides a timely overview of key ABM methodologies and the most innovative approaches through a variety of empirical applications.  It features cutting-edge research from leading academics and practitioners, and will provide a guide for characterising and parameterising human agents in empirical ABM.  In order to facilitate learning, this text shares the valuable experiences of other modellers in particular modelling situations. Very little has been published in the area of empirical ABM, and this contributed volume will appeal to graduate-level students and researchers studying simulation modeling in economics, sociology, ecology, and trans-disciplinary studies, such as topics related to sustainability. In a similar vein to the instruction found in a cookbook, this text provides the empirical modeller with a set of 'recipes'  ready to be implemented. Agent-based modeling (AB...

  7. Numerical modelling of river morphodynamics: Latest developments and remaining challenges

    Science.gov (United States)

    Siviglia, Annunziato; Crosato, Alessandra

    2016-07-01

    Numerical morphodynamic models provide scientific frameworks for advancing our understanding of river systems. The research on involved topics is an important and socially relevant undertaking regarding our environment. Nowadays numerical models are used for different purposes, from answering questions about basic morphodynamic research to managing complex river engineering problems. Due to increasing computer power and the development of advanced numerical techniques, morphodynamic models are now more and more used to predict the bed patterns evolution to a broad spectrum of spatial and temporal scales. The development and the success of application of such models are based upon a wide range of disciplines from applied mathematics for the numerical solution of the equations to geomorphology for the physical interpretation of the results. In this light we organized this special issue (SI) soliciting multidisciplinary contributions which encompass any aspect needed for the development and applications of such models. Most of the papers in the SI stem from contributions to session HS9.5/GM7.11 on numerical modelling and experiments in river morphodynamics at the European Geosciences Union (EGU) General Assembly held in Vienna, April 27th to May 2nd 2014.

  8. Intravenous Therapy: Hazards, Complications and Their Prevention ...

    African Journals Online (AJOL)

    Breaks in aseptic techniques, faulty handling of parenteral fluid containers, failure to discard out-dated intravenous solutions and tubings contribute to occurrence of intravenous-associated sepsis. Improper technique and lack of pharmaceutical knowledge when adding drugs into intravenous fluids contribute to ...

  9. Informing soil models using pedotransfer functions: challenges and perspectives

    Science.gov (United States)

    Pachepsky, Yakov; Romano, Nunzio

    2015-04-01

    Pedotransfer functions (PTFs) are empirical relationships between parameters of soil models and more easily obtainable data on soil properties. PTFs have become an indispensable tool in modeling soil processes. As alternative methods to direct measurements, they bridge the data we have and data we need by using soil survey and monitoring data to enable modeling for real-world applications. Pedotransfer is extensively used in soil models addressing the most pressing environmental issues. The following is an attempt to provoke a discussion by listing current issues that are faced by PTF development. 1. As more intricate biogeochemical processes are being modeled, development of PTFs for parameters of those processes becomes essential. 2. Since the equations to express PTF relationships are essentially unknown, there has been a trend to employ highly nonlinear equations, e.g. neural networks, which in theory are flexible enough to simulate any dependence. This, however, comes with the penalty of large number of coefficients that are difficult to estimate reliably. A preliminary classification applied to PTF inputs and PTF development for each of the resulting groups may provide simple, transparent, and more reliable pedotransfer equations. 3. The multiplicity of models, i.e. presence of several models producing the same output variables, is commonly found in soil modeling, and is a typical feature in the PTF research field. However, PTF intercomparisons are lagging behind PTF development. This is aggravated by the fact that coefficients of PTF based on machine-learning methods are usually not reported. 4. The existence of PTFs is the result of some soil processes. Using models of those processes to generate PTFs, and more general, developing physics-based PTFs remains to be explored. 5. Estimating the variability of soil model parameters becomes increasingly important, as the newer modeling technologies such as data assimilation, ensemble modeling, and model

  10. Challenges in Modeling the Sun-Earth System

    Science.gov (United States)

    Spann, James

    2004-01-01

    The transfer of mass, energy and momentum through the coupled Sun-Earth system spans a wide range of scales in time and space. While profound advances have been made in modeling isolated regions of the Sun-Earth system, minimal progress has been achieved in modeling the end-to-end system. Currently, end-to-end modeling of the Sun-Earth system is a major goal of the National Space Weather and NASA Living With a Star (LWS) programs. The uncertainty in the underlying physics responsible for coupling contiguous regions of the Sun-Earth system is recognized as a significant barrier to progress. Our limited understanding of the underlying coupling physics is illustrated by the following example questions: how does the propagation of a typical CME/solar flare influence the measured properties of the solar wind at 1 AU? How does the solar wind compel the dynamic response of the Earth's magnetosphere? How is variability in the ionosphere-thermosphere system coupled to magnetospheric variations? Why do these and related important questions remain unanswered? What are the primary problems that need to be resolved to enable significant progress in comprehensive modeling of the Sun-Earth system? Which model/technique improvements are required and what new data coverage is required to enable full model advances? This poster opens the discussion for how these and other important questions can be addressed. A workshop scheduled for October 8-22, 2004 in Huntsville, Alabama, will be a forum for identifying ana exploring promising new directions and approaches for characterizing and understanding the system. To focus the discussion, the workshop will emphasize the genesis, evolution, propagation and interaction of high-speed solar wind streamers or CME/flares with geospace and the subsequent response of geospace from its outer reaches in the magnetosphere to the lower edge of the ionosphere-mesosphere-thermosphere. Particular emphasis will be placed on modeling the coupling aspects

  11. Computational brain models: Advances from system biology and future challenges

    Directory of Open Access Journals (Sweden)

    George E. Barreto

    2015-02-01

    Full Text Available Computational brain models focused on the interactions between neurons and astrocytes, modeled via metabolic reconstructions, are reviewed. The large source of experimental data provided by the -omics techniques and the advance/application of computational and data-management tools are being fundamental. For instance, in the understanding of the crosstalk between these cells, the key neuroprotective mechanisms mediated by astrocytes in specific metabolic scenarios (1 and the identification of biomarkers for neurodegenerative diseases (2,3. However, the modeling of these interactions demands a clear view of the metabolic and signaling pathways implicated, but most of them are controversial and are still under evaluation (4. Hence, to gain insight into the complexity of these interactions a current view of the main pathways implicated in the neuron-astrocyte communication processes have been made from recent experimental reports and reviews. Furthermore, target problems, limitations and main conclusions have been identified from metabolic models of the brain reported from 2010. Finally, key aspects to take into account into the development of a computational model of the brain and topics that could be approached from a systems biology perspective in future research are highlighted.

  12. Master Data Management Model in Company: Challenges and Opportunity

    Directory of Open Access Journals (Sweden)

    Indrajani Indrajani

    2015-12-01

    Full Text Available The purpose of this research is to analyze, design, and implement Master Data Management (MDM model for company, which include database processing that will be used in the quality of data customer and produce single view of customer. The research method used is literature study from a variety of journals, books, e-books, and articles on the internet. Also, fact finding techniques are done, such as by analyze, collect, and examine the documents, interviews, and observations. Then, other research methods used to analyze and design MDM model are using cleansing and matching technique. The result obtained from this research is animplementation MDM model for the company, where if implemented, will improve the quality of data significantly. The conclusion which can be obtained from this research is that MDM is one of the factors thatcan improve the quality of customer data.

  13. Simple model systems: a challenge for Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Di Carlo Marta

    2012-04-01

    Full Text Available Abstract The success of biomedical researches has led to improvement in human health and increased life expectancy. An unexpected consequence has been an increase of age-related diseases and, in particular, neurodegenerative diseases. These disorders are generally late onset and exhibit complex pathologies including memory loss, cognitive defects, movement disorders and death. Here, it is described as the use of simple animal models such as worms, fishes, flies, Ascidians and sea urchins, have facilitated the understanding of several biochemical mechanisms underlying Alzheimer's disease (AD, one of the most diffuse neurodegenerative pathologies. The discovery of specific genes and proteins associated with AD, and the development of new technologies for the production of transgenic animals, has helped researchers to overcome the lack of natural models. Moreover, simple model systems of AD have been utilized to obtain key information for evaluating potential therapeutic interventions and for testing efficacy of putative neuroprotective compounds.

  14. Extending the Challenge-Hindrance Model of Occupational Stress: The Role of Appraisal

    Science.gov (United States)

    Webster, Jennica R.; Beehr, Terry A.; Love, Kevin

    2011-01-01

    Interest regarding the challenge-hindrance occupational stress model has increased in recent years, however its theoretical foundation has not been tested. Drawing from the transactional theory of stress, this study tests the assumptions made in past research (1) that workload and responsibility are appraised as challenges and role ambiguity and…

  15. Intravenous Antiepileptic Drugs in Russia

    Directory of Open Access Journals (Sweden)

    P. N. Vlasov

    2014-01-01

    Full Text Available Launching four intravenous antiepileptic drugs: valproate (Depakene and Convulex, lacosamide (Vimpat, and levetiracetam (Keppra – into the Russian market has significantly broadened the possibilities of rendering care to patients in seizure emergency situations. The chemi- cal structure, mechanisms of action, indications/contraindications, clinical effectiveness and tolerability, advantages/disadvantages, and adverse events of using these drugs in urgent and elective neurology are discussed. 

  16. Models meet data: Challenges and opportunities in implementing land management in Earth system models.

    Science.gov (United States)

    Pongratz, Julia; Dolman, Han; Don, Axel; Erb, Karl-Heinz; Fuchs, Richard; Herold, Martin; Jones, Chris; Kuemmerle, Tobias; Luyssaert, Sebastiaan; Meyfroidt, Patrick; Naudts, Kim

    2018-04-01

    As the applications of Earth system models (ESMs) move from general climate projections toward questions of mitigation and adaptation, the inclusion of land management practices in these models becomes crucial. We carried out a survey among modeling groups to show an evolution from models able only to deal with land-cover change to more sophisticated approaches that allow also for the partial integration of land management changes. For the longer term a comprehensive land management representation can be anticipated for all major models. To guide the prioritization of implementation, we evaluate ten land management practices-forestry harvest, tree species selection, grazing and mowing harvest, crop harvest, crop species selection, irrigation, wetland drainage, fertilization, tillage, and fire-for (1) their importance on the Earth system, (2) the possibility of implementing them in state-of-the-art ESMs, and (3) availability of required input data. Matching these criteria, we identify "low-hanging fruits" for the inclusion in ESMs, such as basic implementations of crop and forestry harvest and fertilization. We also identify research requirements for specific communities to address the remaining land management practices. Data availability severely hampers modeling the most extensive land management practice, grazing and mowing harvest, and is a limiting factor for a comprehensive implementation of most other practices. Inadequate process understanding hampers even a basic assessment of crop species selection and tillage effects. The need for multiple advanced model structures will be the challenge for a comprehensive implementation of most practices but considerable synergy can be gained using the same structures for different practices. A continuous and closer collaboration of the modeling, Earth observation, and land system science communities is thus required to achieve the inclusion of land management in ESMs. © 2017 John Wiley & Sons Ltd.

  17. Challenging the Standard Model with the muon g − 2

    Indian Academy of Sciences (India)

    The discrepancy between experiment and the Standard Model prediction of ... The measurement of the anomalous magnetic moment of the muon aµ = (g−2)/2 ( ... to evaluate the leading-order hadronic term (see [3,4] for recent reviews). .... update of their previous analysis and a new preliminary one based on data collected.

  18. Mathematical Modeling: Challenging the Figured Worlds of Elementary Mathematics

    Science.gov (United States)

    Wickstrom, Megan H.

    2017-01-01

    This article is a report on a teacher study group that focused on three elementary teachers' perceptions of mathematical modeling in contrast to typical mathematics instruction. Through the theoretical lens of figured worlds, I discuss how mathematics instruction was conceptualized across the classrooms in terms of artifacts, discourse, and…

  19. Schoolwide Enrichment Model: Challenging All Children to Excel

    Science.gov (United States)

    Beecher, Margaret

    2010-01-01

    This article summarizes how the components of the Schoolwide Enrichment Model were used to dramatically reduce the achievement gap in a school with a high at-risk student population. The theories of enrichment and instructional differentiation replaced an existing remedial paradigm and a strength-based methodology was embraced by the school…

  20. Challenges in soil erosion research and prediction model development

    Science.gov (United States)

    Quantification of soil erosion has been traditionally considered as a surface hydrologic process with equations for soil detachment and sediment transport derived from the mechanics and hydraulics of the rainfall and surface flow. Under the current erosion modeling framework, the soil has a constant...

  1. Leadership Identity Development: Challenges in Applying a Developmental Model

    Science.gov (United States)

    Komives, Susan R.; Longerbeam, Susan D.; Mainella, Felicia; Osteen, Laura; Owen, Julie E.; Wagner, Wendy

    2009-01-01

    The leadership identity development (LID) grounded theory (Komives, Owen, Longerbeam, Mainella, & Osteen, 2005) and related LID model (Komives, Longerbeam, Owen, Mainella, & Osteen, 2006) present a framework for understanding how individual college students develop the social identity of being collaborative, relational leaders…

  2. Development of a translational model to screen medications for cocaine use disorder II: Choice between intravenous cocaine and money in humans

    Science.gov (United States)

    Lile, Joshua A.; Stoops, William W.; Rush, Craig R.; Negus, S. Stevens; Glaser, Paul E. A.; Hatton, Kevin W.; Hays, Lon R.

    2016-01-01

    Background A medication for treating cocaine use disorder has yet to be approved. Laboratory-based evaluation of candidate medications in animals and humans is a valuable means to demonstrate safety, tolerability and initial efficacy of potential medications. However, animal-to-human translation has been hampered by a lack of coordination. Therefore, we designed homologous cocaine self-administration studies in rhesus monkeys (see companion article) and human subjects in an attempt to develop linked, functionally equivalent procedures for research on candidate medications for cocaine use disorder. Methods Eight (N=8) subjects with cocaine use disorder completed 12 experimental sessions in which they responded to receive money ($0.01, $1.00 and $3.00) or intravenous cocaine (0, 3, 10 and 30 mg/70 kg) under independent, concurrent progressive-ratio schedules. Prior to the completion of 9 choice trials, subjects sampled the cocaine dose available during that session and were informed of the monetary alternative value. Results The allocation of behavior varied systematically as a function of cocaine dose and money value. Moreover, a similar pattern of cocaine choice was demonstrated in rhesus monkeys and humans across different cocaine doses and magnitudes of the species-specific alternative reinforcers. The subjective and cardiovascular responses to IV cocaine were an orderly function of dose, although heart rate and blood pressure remained within safe limits. Conclusions These coordinated studies successfully established drug vs. non-drug choice procedures in humans and rhesus monkeys that yielded similar cocaine choice behavior across species. This translational research platform will be used in future research to enhance the efficiency of developing interventions to reduce cocaine use. PMID:27269368

  3. Effects of humeral intraosseous versus intravenous epinephrine on pharmacokinetics and return of spontaneous circulation in a porcine cardiac arrest model: A randomized control trial.

    Science.gov (United States)

    Johnson, Don; Garcia-Blanco, Jose; Burgert, James; Fulton, Lawrence; Kadilak, Patrick; Perry, Katherine; Burke, Jeffrey

    2015-09-01

    Cardiopulmonary Resuscitation (CPR), defibrillation, and epinephrine administration are pillars of advanced cardiac life support (ACLS). Intraosseous (IO) access is an alternative route for epinephrine administration when intravenous (IV) access is unobtainable. Previous studies indicate the pharmacokinetics of epinephrine administration via IO and IV routes differ, but it is not known if the difference influences return of spontaneous circulation (ROSC). The purpose of this prospective, experimental study was to determine the effects of humeral IO (HIO) and IV epinephrine administration during cardiac arrest on pharmacokinetics, ROSC, and odds of survival. Swine (N = 21) were randomized into 3 groups: humeral IO (HIO), peripheral IV (IV) and CPR/defibrillation control. Cardiac arrest was induced under general anesthesia. The swine remained in arrest for 2 min without intervention. Chest compressions were initiated and continued for 2 min. Epinephrine was administered and serial blood samples collected for pharmacokinetic analysis over 4 min. Defibrillation and epinephrine administration proceeded according to ACLS guidelines continuing for 20 min or until ROSC. Seven HIO swine, 4 IV swine, and no control swine had ROSC. There were no significant differences in ROSC, maximum concentration; except at 30 s, and time-to-concentration-maximum between the HIO and IV groups. Significant differences existed between the experimental groups and the control. The HIO delivers a higher concentration of epinephrine than the IV route at 30 s which may be a survival advantage. Clinicians may consider using the IO route to administer epinephrine during CA when there is no preexisting IV access or when IV access is unobtainable.

  4. Intravenous administration of mesenchymal stem cells exerts therapeutic effects on parkinsonian model of rats: Focusing on neuroprotective effects of stromal cell-derived factor-1α

    Directory of Open Access Journals (Sweden)

    Tayra Judith

    2010-04-01

    Full Text Available Abstract Background Mesenchymal stem cells (MSCs are pluripotent stem cells derived from bone marrow with secretory functions of various neurotrophic factors. Stromal cell-derived factor-1α (SDF-1α is also reported as one of chemokines released from MSCs. In this research, the therapeutic effects of MSCs through SDF-1α were explored. 6-hydroxydopamine (6-OHDA, 20 μg was injected into the right striatum of female SD rats with subsequent administration of GFP-labeled MSCs, fibroblasts, (i.v., 1 × 107 cells, respectively or PBS at 2 hours after 6-OHDA injection. All rats were evaluated behaviorally with cylinder test and amphetamine-induced rotation test for 1 month with consequent euthanasia for immunohistochemical evaluations. Additionally, to explore the underlying mechanisms, neuroprotective effects of SDF-1α were explored using 6-OHDA-exposed PC12 cells by using dopamine (DA assay and TdT-mediated dUTP-biotin nick-end labeling (TUNEL staining. Results Rats receiving MSC transplantation significantly ameliorated behaviorally both in cylinder test and amphetamine-induced rotation test compared with the control groups. Correspondingly, rats with MSCs displayed significant preservation in the density of tyrosine hydroxylase (TH-positive fibers in the striatum and the number of TH-positive neurons in the substantia nigra pars compacta (SNc compared to that of control rats. In the in vitro study, SDF-1α treatment increased DA release and suppressed cell death induced by 6-OHDA administration compared with the control groups. Conclusions Consequently, MSC transplantation might exert neuroprotection on 6-OHDA-exposed dopaminergic neurons at least partly through anti-apoptotic effects of SDF-1α. The results demonstrate the potentials of intravenous MSC administration for clinical applications, although further explorations are required.

  5. Challenges in Modeling the Degradation of Ceramic Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Devanathan, Ramaswami; Gao, Fei; Sun, Xin

    2011-09-01

    We identify the state of the art, gaps in current understanding, and key research needs in the area of modeling the long-term degradation of ceramic waste forms for nuclear waste disposition. The directed purpose of this report is to define a roadmap for Waste IPSC needs to extend capabilities of waste degradation to ceramic waste forms, which overlaps with the needs of the subconsinuum scale of FMM interests. The key knowledge gaps are in the areas of (i) methodology for developing reliable interatomic potentials to model the complex atomic-level interactions in waste forms; (ii) characterization of water interactions at ceramic surfaces and interfaces; and (iii) extension of atomic-level insights to the long time and distance scales relevant to the problem of actinide and fission product immobilization.

  6. Interest rate modeling post-crisis challenges and approaches

    CERN Document Server

    Grbac, Zorana

    2015-01-01

    Filling a gap in the literature caused by the recent financial crisis, this book provides a treatment of the techniques needed to model and evaluate interest rate derivatives according to the new paradigm for fixed income markets. Concerning this new development, there presently exist only research articles and two books, one of them an edited volume, both being written by researchers working mainly in practice. The aim of this book is to concentrate primarily on the methodological side, thereby providing an overview of the state-of-the-art and also clarifying the link between the new models and the classical literature. The book is intended to serve as a guide for graduate students and researchers as well as practitioners interested in the paradigm change for fixed income markets. A basic knowledge of fixed income markets and related stochastic methodology is assumed as a prerequisite.

  7. Atmospheric dispersion modeling: Challenges of the Fukushima Daiichi response

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Gayle [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Nasstrom, John [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pobanz, Brenda [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Foster, Kevin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simpson, Matthew [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vogt, Phil [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Aluzzi, Fernando [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Homann, Steve [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-05-01

    In this research, the U.S. Department of Energy’s (DOE) National Atmospheric Release Advisory Center (NARAC) provided a wide range of predictions and analyses as part of the response to the Fukushima Daiichi Nuclear Power Plant accident including: daily Japanese weather forecasts and atmospheric transport predictions to inform planning for field monitoring operations and to provide U.S. government agencies with ongoing situational awareness of meteorological conditions; estimates of possible dose in Japan based on hypothetical U.S. Nuclear Regulatory Commission scenarios of potential radionuclide releases to support protective action planning for U.S. citizens; predictions of possible plume arrival times and dose levels at U.S. locations; and source estimation and plume model refinement based on atmospheric dispersion modeling and available monitoring data.

  8. Challenges in the modeling of tidal disruption events lightcurves

    Directory of Open Access Journals (Sweden)

    Lodato G.

    2012-12-01

    Full Text Available In this contribution, I review the recent developments on the modeling of the lightcurve of tidal disruption events. Our understanding has evolved significantly from the earlier seminal results that imply a simple power-law decay of the bolometric light curve as t−5/3. We now know that the details of the rise to the peak of the lightcurve is determined mainly by the internal structure of the disrupted star. We also have improved models for the disc thermal emission, showing that in this case the decline of the luminosity with time should be much flatter than the standard t−5/3 law, especially in optical and UV wavelengths, while the X-ray lightcurve is generally best suited to track the bolometric one. Finally, we are just starting to explore the interesting general relativistic effects that might arise for such events, for which the tidal radius lies very close to the black hole event horizon.

  9. Challenges in Modeling the Degradation of Ceramic Waste Forms

    International Nuclear Information System (INIS)

    Devanathan, Ramaswami; Gao, Fei; Sun, Xin

    2011-01-01

    We identify the state of the art, gaps in current understanding, and key research needs in the area of modeling the long-term degradation of ceramic waste forms for nuclear waste disposition. The directed purpose of this report is to define a roadmap for Waste IPSC needs to extend capabilities of waste degradation to ceramic waste forms, which overlaps with the needs of the subconsinuum scale of FMM interests. The key knowledge gaps are in the areas of (i) methodology for developing reliable interatomic potentials to model the complex atomic-level interactions in waste forms; (ii) characterization of water interactions at ceramic surfaces and interfaces; and (iii) extension of atomic-level insights to the long time and distance scales relevant to the problem of actinide and fission product immobilization.

  10. Understanding rare disease pathogenesis: a grand challenge for model organisms.

    Science.gov (United States)

    Hieter, Philip; Boycott, Kym M

    2014-10-01

    In this commentary, Philip Hieter and Kym Boycott discuss the importance of model organisms for understanding pathogenesis of rare human genetic diseases, and highlight the work of Brooks et al., "Dysfunction of 60S ribosomal protein L10 (RPL10) disrupts neurodevelopment and causes X-linked microcephaly in humans," published in this issue of GENETICS. Copyright © 2014 by the Genetics Society of America.

  11. The new challenges of multiplex networks: Measures and models

    Science.gov (United States)

    Battiston, Federico; Nicosia, Vincenzo; Latora, Vito

    2017-02-01

    What do societies, the Internet, and the human brain have in common? They are all examples of complex relational systems, whose emerging behaviours are largely determined by the non-trivial networks of interactions among their constituents, namely individuals, computers, or neurons, rather than only by the properties of the units themselves. In the last two decades, network scientists have proposed models of increasing complexity to better understand real-world systems. Only recently we have realised that multiplexity, i.e. the coexistence of several types of interactions among the constituents of a complex system, is responsible for substantial qualitative and quantitative differences in the type and variety of behaviours that a complex system can exhibit. As a consequence, multilayer and multiplex networks have become a hot topic in complexity science. Here we provide an overview of some of the measures proposed so far to characterise the structure of multiplex networks, and a selection of models aiming at reproducing those structural properties and quantifying their statistical significance. Focusing on a subset of relevant topics, this brief review is a quite comprehensive introduction to the most basic tools for the analysis of multiplex networks observed in the real-world. The wide applicability of multiplex networks as a framework to model complex systems in different fields, from biology to social sciences, and the colloquial tone of the paper will make it an interesting read for researchers working on both theoretical and experimental analysis of networked systems.

  12. Educational Modelling Language and Learning Design: new challenges for instructional re-usability and personalized learning

    NARCIS (Netherlands)

    Hummel, Hans; Manderveld, Jocelyn; Tattersall, Colin; Koper, Rob

    2003-01-01

    Published: Hummel, H. G. K., Manderveld, J. M., Tattersall, C.,& Koper, E. J. R. (2004). Educational Modelling Language: new challenges for instructional re-usability and personalized learning. International Journal of Learning Technology, 1, 1, 110-111.

  13. Business Models and Producer-Owned Ventures: Choices, Challenges, and Changes

    OpenAIRE

    Kenkel, Philip L.; Park, John L.

    2007-01-01

    Producer-owned business models are rapidly evolving. Producer-owned, value-added ventures face a number of organizational challenges, including capital acquisition, security exchange registration, antitrust exemption, borrowing eligibility, and operational flexibility. This paper examines the success of evolving producer-owned business models in addressing these challenges. The need for uniform criteria to distinguish producer-owned business from other business forms throughout the complex st...

  14. Assessing dengue vaccination impact: Model challenges and future directions.

    Science.gov (United States)

    Recker, Mario; Vannice, Kirsten; Hombach, Joachim; Jit, Mark; Simmons, Cameron P

    2016-08-31

    In response to the sharp rise in the global burden caused by dengue virus (DENV) over the last few decades, the WHO has set out three specific key objectives in its disease control strategy: (i) to estimate the true burden of dengue by 2015; (ii) a reduction in dengue mortality by at least 50% by 2020 (used as a baseline); and (iii) a reduction in dengue morbidity by at least 25% by 2020. Although various elements will all play crucial parts in achieving this goal, from diagnosis and case management to integrated surveillance and outbreak response, sustainable vector control, vaccine implementation and finally operational and implementation research, it seems clear that new tools (e.g. a safe and effective vaccine and/or effective vector control) are key to success. The first dengue vaccine was licensed in December 2015, Dengvaxia® (CYD-TDV) developed by Sanofi Pasteur. The WHO has provided guidance on the use of CYD-TDV in endemic countries, for which there are a variety of considerations beyond the risk-benefit evaluation done by regulatory authorities, including public health impact and cost-effectiveness. Population-level vaccine impact and economic and financial aspects are two issues that can potentially be considered by means of mathematical modelling, especially for new products for which empirical data are still lacking. In December 2014 a meeting was convened by the WHO in order to revisit the current status of dengue transmission models and their utility for public health decision-making. Here, we report on the main points of discussion and the conclusions of this meeting, as well as next steps for maximising the use of mathematical models for vaccine decision-making. Copyright © 2016.

  15. Exploring the oxygen challenge test as a microcirculation evaluation model

    Directory of Open Access Journals (Sweden)

    Hugo Ferreira

    2013-12-01

    Full Text Available Cutaneous microcirculation has emerged in recent years as a practical accessible subject for the study of peripheral circulation. Non-invasive techniques such as Laser Doppler Flowmetry (LDF, skin Evaporimetry and Transcutaneous Gasimetry in association with provocation tests, render cutaneous circulation a very attractive research model. This study was applied to a group of healthy young female volunteers, (n = 8, (21,6 ± 2,6 years old breathing a 100 % oxygen atmosphere for 10 minutes. This test allowed us to evaluate the circulatory response in the lower limb microcirculation. Measurement techniques included local blood flow by LDF, Transcutaneous (tc pO2 partial pressure and Transepidermal Water Loss (TEWL by Evaporimetry. Data analysis revels that tc-pO2 and LDF changed significantly during the test. A reciprocal evolution profile was registered in LDF and TEWL, which seems to support previous data that changes in local blood flow may influence the epidermal “barrier” function. This model seems suitable to characterize the lower limb microcirculation.

  16. Modeling food matrix effects on chemical reactivity: Challenges and perspectives.

    Science.gov (United States)

    Capuano, Edoardo; Oliviero, Teresa; van Boekel, Martinus A J S

    2017-06-29

    The same chemical reaction may be different in terms of its position of the equilibrium (i.e., thermodynamics) and its kinetics when studied in different foods. The diversity in the chemical composition of food and in its structural organization at macro-, meso-, and microscopic levels, that is, the food matrix, is responsible for this difference. In this viewpoint paper, the multiple, and interconnected ways the food matrix can affect chemical reactivity are summarized. Moreover, mechanistic and empirical approaches to explain and predict the effect of food matrix on chemical reactivity are described. Mechanistic models aim to quantify the effect of food matrix based on a detailed understanding of the chemical and physical phenomena occurring in food. Their applicability is limited at the moment to very simple food systems. Empirical modeling based on machine learning combined with data-mining techniques may represent an alternative, useful option to predict the effect of the food matrix on chemical reactivity and to identify chemical and physical properties to be further tested. In such a way the mechanistic understanding of the effect of the food matrix on chemical reactions can be improved.

  17. Challenges for the kinetic unified dark matter model

    International Nuclear Information System (INIS)

    Giannakis, Dimitrios; Hu, Wayne

    2005-01-01

    Given that the dark matter and dark energy in the Universe affect cosmological observables only gravitationally, their phenomenology may be described by a single stress-energy tensor. True unification however requires a theory that reproduces the successful phenomenology of ΛCDM and that requirement places specific constraints on the stress structure of the matter. We show that a recently proposed unification through an offset quadratic kinetic term for a scalar field is exactly equivalent to a fluid with a closed-form barotropic equation of state plus cosmological constant. The finite pressure at high densities introduces a cutoff in the linear power spectrum, which may alleviate the dark matter substructure problem; we provide a convenient fitting function for such studies. Given that sufficient power must remain to reionize the Universe, the equation of state today is nonrelativistic with p∝ρ 2 and a Jeans scale in the parsec regime for all relevant densities. Structure may then be evolved into the nonlinear regime with standard hydrodynamic techniques. In fact, the model is equivalent to the well-studied collisional dark matter with negligible mean free path. If recent observations of the triaxiality of dark matter halos and ram pressure stripping in galaxy clusters are confirmed, this model will be ruled out

  18. Stratified flows with variable density: mathematical modelling and numerical challenges.

    Science.gov (United States)

    Murillo, Javier; Navas-Montilla, Adrian

    2017-04-01

    Stratified flows appear in a wide variety of fundamental problems in hydrological and geophysical sciences. They may involve from hyperconcentrated floods carrying sediment causing collapse, landslides and debris flows, to suspended material in turbidity currents where turbulence is a key process. Also, in stratified flows variable horizontal density is present. Depending on the case, density varies according to the volumetric concentration of different components or species that can represent transported or suspended materials or soluble substances. Multilayer approaches based on the shallow water equations provide suitable models but are not free from difficulties when moving to the numerical resolution of the governing equations. Considering the variety of temporal and spatial scales, transfer of mass and energy among layers may strongly differ from one case to another. As a consequence, in order to provide accurate solutions, very high order methods of proved quality are demanded. Under these complex scenarios it is necessary to observe that the numerical solution provides the expected order of accuracy but also converges to the physically based solution, which is not an easy task. To this purpose, this work will focus in the use of Energy balanced augmented solvers, in particular, the Augmented Roe Flux ADER scheme. References: J. Murillo , P. García-Navarro, Wave Riemann description of friction terms in unsteady shallow flows: Application to water and mud/debris floods. J. Comput. Phys. 231 (2012) 1963-2001. J. Murillo B. Latorre, P. García-Navarro. A Riemann solver for unsteady computation of 2D shallow flows with variable density. J. Comput. Phys.231 (2012) 4775-4807. A. Navas-Montilla, J. Murillo, Energy balanced numerical schemes with very high order. The Augmented Roe Flux ADER scheme. Application to the shallow water equations, J. Comput. Phys. 290 (2015) 188-218. A. Navas-Montilla, J. Murillo, Asymptotically and exactly energy balanced augmented flux

  19. Area under the curve predictions of dalbavancin, a new lipoglycopeptide agent, using the end of intravenous infusion concentration data point by regression analyses such as linear, log-linear and power models.

    Science.gov (United States)

    Bhamidipati, Ravi Kanth; Syed, Muzeeb; Mullangi, Ramesh; Srinivas, Nuggehally

    2018-02-01

    1. Dalbavancin, a lipoglycopeptide, is approved for treating gram-positive bacterial infections. Area under plasma concentration versus time curve (AUC inf ) of dalbavancin is a key parameter and AUC inf /MIC ratio is a critical pharmacodynamic marker. 2. Using end of intravenous infusion concentration (i.e. C max ) C max versus AUC inf relationship for dalbavancin was established by regression analyses (i.e. linear, log-log, log-linear and power models) using 21 pairs of subject data. 3. The predictions of the AUC inf were performed using published C max data by application of regression equations. The quotient of observed/predicted values rendered fold difference. The mean absolute error (MAE)/root mean square error (RMSE) and correlation coefficient (r) were used in the assessment. 4. MAE and RMSE values for the various models were comparable. The C max versus AUC inf exhibited excellent correlation (r > 0.9488). The internal data evaluation showed narrow confinement (0.84-1.14-fold difference) with a RMSE models predicted AUC inf with a RMSE of 3.02-27.46% with fold difference largely contained within 0.64-1.48. 5. Regardless of the regression models, a single time point strategy of using C max (i.e. end of 30-min infusion) is amenable as a prospective tool for predicting AUC inf of dalbavancin in patients.

  20. Facing up to 'challenging behaviour': a model for training in staff-client interaction.

    Science.gov (United States)

    Farrell, Gerald A; Shafiei, Touran; Salmon, Peter

    2010-07-01

    This paper draws on theory and evidence to develop a conceptual staff training model for the management of 'challenging behaviour'. Staff working with clients who are experienced as challenging commonly report negative feelings such as anxiety, anger, guilt, fear, self-blame and powerlessness, as well as dissatisfaction with their jobs. Current training programmes in challenging behaviour offer a 'smorgasbord' of content, without a clearly defined conceptual framework. Medline and PsychInfo were searched for papers in English from 1998 to 2008, linking 'nurs*' to 'challenging behavio*' and its related terms. Additional hand-searching identified informative papers from disciplines outside nursing older than the search period. We developed an applied model for training educators in respect of challenging behaviours. The model directs educators to consider: the influence of the nurse, including their values, emotional processes and behavioural skills; features of the client; and features of the situation in which the behaviour occurs, including its culture and working practices and physical environment. The most striking implication of the model is that it explicitly recognizes the importance of domains of learning other than skill. This enables educators to find educationally appropriate responses to resource limitations that inevitably constrain training. Challenging behaviour should be considered as a product of several intertwined factors: the actors involved - nurses, clients and others - and the situation in which the behaviour occurs, including its culture and working practices and physical environment.

  1. BIG DATA-Related Challenges and Opportunities in Earth System Modeling

    Science.gov (United States)

    Bamzai, A. S.

    2012-12-01

    Knowledge of the Earth's climate has increased immensely in recent decades, both through observational analysis and modeling. BIG DATA-related challenges emerge in our quest for understanding the variability and predictability of the climate and earth system on a range of time scales, as well as in our endeavor to improve predictive capability using state-of-the-science models. To enable further scientific discovery, bottlenecks in current paradigms need to be addressed. An overview of current NSF activities in Earth System Modeling with a focus on associated data-related challenges and opportunities, will be presented.

  2. Phase 1A safety assessment of intravenous amitriptyline

    NARCIS (Netherlands)

    Fridrich, Peter; Colvin, Hans Peter; Zizza, Anthony; Wasan, Ajay D.; Lukanich, Jean; Lirk, Philipp; Saria, Alois; Zernig, Gerald; Hamp, Thomas; Gerner, Peter

    2007-01-01

    The antidepressant amitriptyline is used as an adjuvant in the treatment of chronic pain. Among its many actions, amitriptyline blocks Na+ channels and nerves in several animal and human models. As perioperative intravenous lidocaine has been suggested to decrease postoperative pain, amitriptyline,

  3. Energy efficiency and renewable energy modeling with ETSAP TIAM - challenges, opportunities, and solutions

    DEFF Research Database (Denmark)

    Gregg, Jay Sterling; Balyk, Olexandr; Pérez, Cristian Hernán Cabrera

    over pre-industrial times. To accomplish this, pathways are constructed for each objective, which then form the basis for a scenario analysis using the Energy Technology System Analysis Program TIMES Integrated Assessment Model (ETSAP-TIAM). This presentation focuses on the modeling challenges...

  4. Spatial agent-based models for socio-ecological systems: challenges and prospects

    NARCIS (Netherlands)

    de Filatova, T.; Verburg, P.H.; Parker, D.C.; Stannard, S.R.

    2013-01-01

    Departing from the comprehensive reviews carried out in the field, we identify the key challenges that agent-based methodology faces when modeling coupled socio-ecological systems. Focusing primarily on the papers presented in this thematic issue, we review progress in spatial agent-based models

  5. Grand challenge problems in environmental modeling and remediation: groundwater contaminant transport

    Energy Technology Data Exchange (ETDEWEB)

    Todd Arbogast; Steve Bryant; Clint N. Dawson; Mary F. Wheeler

    1998-08-31

    This report describes briefly the work of the Center for Subsurface Modeling (CSM) of the University of Texas at Austin (and Rice University prior to September 1995) on the Partnership in Computational Sciences Consortium (PICS) project entitled Grand Challenge Problems in Environmental Modeling and Remediation: Groundwater Contaminant Transport.

  6. Ahead of the Curve: Implementation Challenges in Personalized Learning School Models

    Science.gov (United States)

    Bingham, Andrea J.; Pane, John F.; Steiner, Elizabeth D.; Hamilton, Laura S.

    2018-01-01

    In the current educational context, school models that leverage technology to personalize instruction have proliferated, as has student enrollment in, and funding of, such school models. However, even the best laid plans are subject to challenges in design and practice, particularly in the dynamic context of a school. In this collective case…

  7. INTRAVENOUS IMMUNOGLOBULIN IN PEDIATRIC RHEUMATOLOGY PRACTICE

    Directory of Open Access Journals (Sweden)

    E. I. Alexeeva

    2015-01-01

    Full Text Available Modern successful treatment of rheumatic diseases is impossible without the use of intravenous immunoglobulin. The use of intravenous immunoglobulin is based on strict indications developed as a result of long-term multicenter controlled studies. The article highlights the issues of using immunoglobulin in pediatric rheumatology practice, and provides the review of literature with the results from the evaluation of the efficiency of intravenous immunoglobulin confirming the efficiency of the drug only for certain rheumatic diseases. 

  8. Challenges and priorities for modelling livestock health and pathogens in the context of climate change

    Energy Technology Data Exchange (ETDEWEB)

    Özkan, Şeyda [Department of Animal and Aquacultural Sciences, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences (NMBU), Post Box 5003, Ås 1430 (Norway); Vitali, Andrea; Lacetera, Nicola [University of Tuscia, Department of Agriculture and Forestry Science (DAFNE), Via San Camillo De Lellis, snc, Viterbo 01100 (Italy); Amon, Barbara [Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Max-Eyth-Allee 100, Potsdam 14469 (Germany); Bannink, André [Wageningen UR Livestock Research, P.O. Box 338, Wageningen 6700 AH (Netherlands); Bartley, Dave J. [Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik EH26 0PZ (United Kingdom); Blanco-Penedo, Isabel [Animal Welfare Subprogram, IRTA, Veinat de Sies s/n, Monells, Girona 17121 (Spain); Haas, Yvette de [Wageningen UR Livestock Research, P.O. Box 338, Wageningen 6700 AH (Netherlands); Dufrasne, Isabelle [Nutrition Unit, Animal Production Department, Veterinary Faculty, University of Liège, Boulevard de Colonster 20, Bât. B43, Liège 4000 (Belgium); Elliott, John [ADAS UK Ltd, 4205 Park Approach, Thorpe Park, Leeds LS15 8GB (United Kingdom); Eory, Vera [Scotland' s Rural College (SRUC), Peter Wilson Building, Kings Buildings, West Mains Road, Edinburgh EH9 3JG (United Kingdom); Fox, Naomi J. [Scotland' s Rural College (SRUC), Animal and Veterinary Sciences, Roslin Institute Building, Easter Bush, Midlothian EH25 9RG (United Kingdom); Garnsworthy, Phil C. [University of Nottingham, School of Biosciences, Sutton Bonington Campus, Loughborough LE12 5RD (United Kingdom); and others

    2016-11-15

    Climate change has the potential to impair livestock health, with consequences for animal welfare, productivity, greenhouse gas emissions, and human livelihoods and health. Modelling has an important role in assessing the impacts of climate change on livestock systems and the efficacy of potential adaptation strategies, to support decision making for more efficient, resilient and sustainable production. However, a coherent set of challenges and research priorities for modelling livestock health and pathogens under climate change has not previously been available. To identify such challenges and priorities, researchers from across Europe were engaged in a horizon-scanning study, involving workshop and questionnaire based exercises and focussed literature reviews. Eighteen key challenges were identified and grouped into six categories based on subject-specific and capacity building requirements. Across a number of challenges, the need for inventories relating model types to different applications (e.g. the pathogen species, region, scale of focus and purpose to which they can be applied) was identified, in order to identify gaps in capability in relation to the impacts of climate change on animal health. The need for collaboration and learning across disciplines was highlighted in several challenges, e.g. to better understand and model complex ecological interactions between pathogens, vectors, wildlife hosts and livestock in the context of climate change. Collaboration between socio-economic and biophysical disciplines was seen as important for better engagement with stakeholders and for improved modelling of the costs and benefits of poor livestock health. The need for more comprehensive validation of empirical relationships, for harmonising terminology and measurements, and for building capacity for under-researched nations, systems and health problems indicated the importance of joined up approaches across nations. The challenges and priorities identified can

  9. Challenges and priorities for modelling livestock health and pathogens in the context of climate change

    International Nuclear Information System (INIS)

    Özkan, Şeyda; Vitali, Andrea; Lacetera, Nicola; Amon, Barbara; Bannink, André; Bartley, Dave J.; Blanco-Penedo, Isabel; Haas, Yvette de; Dufrasne, Isabelle; Elliott, John; Eory, Vera; Fox, Naomi J.; Garnsworthy, Phil C.

    2016-01-01

    Climate change has the potential to impair livestock health, with consequences for animal welfare, productivity, greenhouse gas emissions, and human livelihoods and health. Modelling has an important role in assessing the impacts of climate change on livestock systems and the efficacy of potential adaptation strategies, to support decision making for more efficient, resilient and sustainable production. However, a coherent set of challenges and research priorities for modelling livestock health and pathogens under climate change has not previously been available. To identify such challenges and priorities, researchers from across Europe were engaged in a horizon-scanning study, involving workshop and questionnaire based exercises and focussed literature reviews. Eighteen key challenges were identified and grouped into six categories based on subject-specific and capacity building requirements. Across a number of challenges, the need for inventories relating model types to different applications (e.g. the pathogen species, region, scale of focus and purpose to which they can be applied) was identified, in order to identify gaps in capability in relation to the impacts of climate change on animal health. The need for collaboration and learning across disciplines was highlighted in several challenges, e.g. to better understand and model complex ecological interactions between pathogens, vectors, wildlife hosts and livestock in the context of climate change. Collaboration between socio-economic and biophysical disciplines was seen as important for better engagement with stakeholders and for improved modelling of the costs and benefits of poor livestock health. The need for more comprehensive validation of empirical relationships, for harmonising terminology and measurements, and for building capacity for under-researched nations, systems and health problems indicated the importance of joined up approaches across nations. The challenges and priorities identified can

  10. Measurement of cerebral blood flow by intravenous xenon-133 technique and a mobile system. Reproducibility using the Obrist model compared to total curve analysis

    DEFF Research Database (Denmark)

    Schroeder, T; Holstein, P; Lassen, N A

    1986-01-01

    and side-to-side asymmetry. Data were analysed according to the Obrist model and the results compared with those obtained using a model correcting for the air passage artifact. Reproducibility was of the same order of magnitude as reported using stationary equipment. The side-to-side CBF asymmetry...... was considerably more reproducible than CBF level. Using a single detector instead of five regional values averaged as the hemispheric flow increased standard deviation of CBF level by 10-20%, while the variation in asymmetry was doubled. In optimal measuring conditions the two models revealed no significant...... differences, but in low flow situations the artifact model yielded significantly more stable results. The present apparatus, equipped with 3-5 detectors covering each hemisphere, offers the opportunity of performing serial CBF measurements in situations not otherwise feasible....

  11. The Electric Vehicles Ecosystem Model: Construct, Analysis and Identification of Key Challenges

    Directory of Open Access Journals (Sweden)

    Zulkarnain

    2014-09-01

    Full Text Available This paper builds a conceptual model of electric vehicles’ (EV ecosystem and value chain build-up. Based on the literature, the research distinguishes the most critical challenges that are on the way of mobility systems’ electrification. Consumers still have some questions that call for answers before they are ready to adopt evs.With regard to technical aspects, some challenges are coming from vehicles, charging infrastructure, battery technology, and standardization. The use of battery in EVs will bring in additional environmental challenges, coming from the battery life cycle for used battery, the manufacturing, and from some materials used and treated in the manufacturing process. The policy aspects include mostly taxation strategies. For most part, established market conditions are still lacking and there are a number of unresolved challenges on both supply and demand side of the EV market.

  12. Summary of the DREAM8 Parameter Estimation Challenge: Toward Parameter Identification for Whole-Cell Models.

    Directory of Open Access Journals (Sweden)

    Jonathan R Karr

    2015-05-01

    Full Text Available Whole-cell models that explicitly represent all cellular components at the molecular level have the potential to predict phenotype from genotype. However, even for simple bacteria, whole-cell models will contain thousands of parameters, many of which are poorly characterized or unknown. New algorithms are needed to estimate these parameters and enable researchers to build increasingly comprehensive models. We organized the Dialogue for Reverse Engineering Assessments and Methods (DREAM 8 Whole-Cell Parameter Estimation Challenge to develop new parameter estimation algorithms for whole-cell models. We asked participants to identify a subset of parameters of a whole-cell model given the model's structure and in silico "experimental" data. Here we describe the challenge, the best performing methods, and new insights into the identifiability of whole-cell models. We also describe several valuable lessons we learned toward improving future challenges. Going forward, we believe that collaborative efforts supported by inexpensive cloud computing have the potential to solve whole-cell model parameter estimation.

  13. Seven challenges for modelling indirect transmission: Vector-borne diseases, macroparasites and neglected tropical diseases

    Directory of Open Access Journals (Sweden)

    T. Déirdre Hollingsworth

    2015-03-01

    Full Text Available Many of the challenges which face modellers of directly transmitted pathogens also arise when modelling the epidemiology of pathogens with indirect transmission – whether through environmental stages, vectors, intermediate hosts or multiple hosts. In particular, understanding the roles of different hosts, how to measure contact and infection patterns, heterogeneities in contact rates, and the dynamics close to elimination are all relevant challenges, regardless of the mode of transmission. However, there remain a number of challenges that are specific and unique to modelling vector-borne diseases and macroparasites. Moreover, many of the neglected tropical diseases which are currently targeted for control and elimination are vector-borne, macroparasitic, or both, and so this article includes challenges which will assist in accelerating the control of these high-burden diseases. Here, we discuss the challenges of indirect measures of infection in humans, whether through vectors or transmission life stages and in estimating the contribution of different host groups to transmission. We also discuss the issues of “evolution-proof” interventions against vector-borne disease.

  14. Seven challenges for modelling indirect transmission: vector-borne diseases, macroparasites and neglected tropical diseases.

    Science.gov (United States)

    Hollingsworth, T Déirdre; Pulliam, Juliet R C; Funk, Sebastian; Truscott, James E; Isham, Valerie; Lloyd, Alun L

    2015-03-01

    Many of the challenges which face modellers of directly transmitted pathogens also arise when modelling the epidemiology of pathogens with indirect transmission--whether through environmental stages, vectors, intermediate hosts or multiple hosts. In particular, understanding the roles of different hosts, how to measure contact and infection patterns, heterogeneities in contact rates, and the dynamics close to elimination are all relevant challenges, regardless of the mode of transmission. However, there remain a number of challenges that are specific and unique to modelling vector-borne diseases and macroparasites. Moreover, many of the neglected tropical diseases which are currently targeted for control and elimination are vector-borne, macroparasitic, or both, and so this article includes challenges which will assist in accelerating the control of these high-burden diseases. Here, we discuss the challenges of indirect measures of infection in humans, whether through vectors or transmission life stages and in estimating the contribution of different host groups to transmission. We also discuss the issues of "evolution-proof" interventions against vector-borne disease. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Industrial Adoption of Model-Based Systems Engineering: Challenges and Strategies

    Science.gov (United States)

    Maheshwari, Apoorv

    As design teams are becoming more globally integrated, one of the biggest challenges is to efficiently communicate across the team. The increasing complexity and multi-disciplinary nature of the products are also making it difficult to keep track of all the information generated during the design process by these global team members. System engineers have identified Model-based Systems Engineering (MBSE) as a possible solution where the emphasis is placed on the application of visual modeling methods and best practices to systems engineering (SE) activities right from the beginning of the conceptual design phases through to the end of the product lifecycle. Despite several advantages, there are multiple challenges restricting the adoption of MBSE by industry. We mainly consider the following two challenges: a) Industry perceives MBSE just as a diagramming tool and does not see too much value in MBSE; b) Industrial adopters are skeptical if the products developed using MBSE approach will be accepted by the regulatory bodies. To provide counter evidence to the former challenge, we developed a generic framework for translation from an MBSE tool (Systems Modeling Language, SysML) to an analysis tool (Agent-Based Modeling, ABM). The translation is demonstrated using a simplified air traffic management problem and provides an example of a potential quite significant value: the ability to use MBSE representations directly in an analysis setting. For the latter challenge, we are developing a reference model that uses SysML to represent a generic infusion pump and SE process for planning, developing, and obtaining regulatory approval of a medical device. This reference model demonstrates how regulatory requirements can be captured effectively through model-based representations. We will present another case study at the end where we will apply the knowledge gained from both case studies to a UAV design problem.

  16. Physics-based distributed snow models in the operational arena: Current and future challenges

    Science.gov (United States)

    Winstral, A. H.; Jonas, T.; Schirmer, M.; Helbig, N.

    2017-12-01

    The demand for modeling tools robust to climate change and weather extremes along with coincident increases in computational capabilities have led to an increase in the use of physics-based snow models in operational applications. Current operational applications include the WSL-SLF's across Switzerland, ASO's in California, and USDA-ARS's in Idaho. While the physics-based approaches offer many advantages there remain limitations and modeling challenges. The most evident limitation remains computation times that often limit forecasters to a single, deterministic model run. Other limitations however remain less conspicuous amidst the assumptions that these models require little to no calibration based on their foundation on physical principles. Yet all energy balance snow models seemingly contain parameterizations or simplifications of processes where validation data are scarce or present understanding is limited. At the research-basin scale where many of these models were developed these modeling elements may prove adequate. However when applied over large areas, spatially invariable parameterizations of snow albedo, roughness lengths and atmospheric exchange coefficients - all vital to determining the snowcover energy balance - become problematic. Moreover as we apply models over larger grid cells, the representation of sub-grid variability such as the snow-covered fraction adds to the challenges. Here, we will demonstrate some of the major sensitivities of distributed energy balance snow models to particular model constructs, the need for advanced and spatially flexible methods and parameterizations, and prompt the community for open dialogue and future collaborations to further modeling capabilities.

  17. Intentional intravenous mercury injection | Yudelowitz | South African ...

    African Journals Online (AJOL)

    Intravenous mercury injection is rarely seen, with few documented cases. Treatment strategies are not clearly defined for such cases, although a few options do show benefit. This case report describes a 29-year-old man suffering from bipolar disorder, who presented following self-inflicted intravenous injection of mercury.

  18. Comparison of the Intraperitoneal, Retroorbital and per Oral Routes for F 18 FDG Administration as Effective Alternatives to Intravenous Administration in Mouse Tumor Models Using Small Animal PET/CT Studies

    International Nuclear Information System (INIS)

    Kim, Chulhan; Kim, In Hye; Kim, Seo il; Kim, Young Sang; Kang, Se Hun; Moon, Seung Hwan; Kim, Tae Sung; Kim, Seok ki

    2011-01-01

    We compared alternative routes for 18F fluorodeoxyglucose (FDG) administration, such as the retroorbital (RO), intraperitoneal (IP) and per oral (PO) routes, with the intravenous (IV) route in normal tissues and tumors of mice. CRL 1642 (ATCC, Lewis lung carcinoma) cells were inoculated in female BALB/c nu/nu mice 6 to 10 weeks old. When the tumor grew to about 9mm in diameter, positron emission tomography (PET) scans were performed after FDG administration via the RO, IP, PO or IV route. Additional serial PET scans were performed using the RO, IV or IP route alternatively from 5 to 29 days after the tumor cell injection. There was no significant difference in the FDG uptake in normal tissues at 60 min after FDG administration via RO, IP and IV routes. PO administration, however, showed delayed distribution and unwanted high gastrointestinal uptake. Tumoral uptake of FDG showed a similar temporal pattern and increased until 60 min after FDG administration in the RO, IP and IV injection groups. In the PO administration group, tumoral uptake was delayed and reduced. There was no statistical difference among the RO, IP and IV administration groups for additional serial PET scans. RO administration is an effective alternative route to IV administration for mouse FDG PET scans using normal mice and tumor models. In addition, IP administration can be a practical alternative in the late phase, although the initial uptake is lower than those in the IV and RO groups.

  19. Participation and occupation in occupational therapy models of practice: A discussion of possibilities and challenges.

    Science.gov (United States)

    Larsson-Lund, Maria; Nyman, Anneli

    2017-11-01

    Occupation has been the focus in occupational therapy practice to greater or lesser degrees from a historical viewpoint. This evokes a need to discuss whether concepts that are added to our field will enhance or blur our focus on occupation. To explore how the concept of participation in the International Classification of Functioning, Disability and Health (ICF) is related to the concept of occupation by reviewing and comparing its use in three models of practice within occupational therapy. The aim was also to generate discussion on possibilities and challenges concerning the relationship of participation and occupation. The models reviewed were The Model of Human Occupation (MOHO), the Canadian Model of Occupational Performance and Engagement (CMOP-E) and the Occupational Therapy Intervention Process Model (OTIPM). The concept of participation was related to occupation in different ways in these models. Based on the review some challenges and considerations for occupational therapy were generated. Relating the concept of participation from the ICF to the concept of occupation in models of practice can be challenging. At the same time, relating the concepts can be a resource to develop occupational therapy and the understanding of occupational issues in society.

  20. Probabilistic risk assessment of gold nanoparticles after intravenous administration by integrating in vitro and in vivo toxicity with physiologically based pharmacokinetic modeling.

    Science.gov (United States)

    Cheng, Yi-Hsien; Riviere, Jim E; Monteiro-Riviere, Nancy A; Lin, Zhoumeng

    2018-04-14

    This study aimed to conduct an integrated and probabilistic risk assessment of gold nanoparticles (AuNPs) based on recently published in vitro and in vivo toxicity studies coupled to a physiologically based pharmacokinetic (PBPK) model. Dose-response relationships were characterized based on cell viability assays in various human cell types. A previously well-validated human PBPK model for AuNPs was applied to quantify internal concentrations in liver, kidney, skin, and venous plasma. By applying a Bayesian-based probabilistic risk assessment approach incorporating Monte Carlo simulation, probable human cell death fractions were characterized. Additionally, we implemented in vitro to in vivo and animal-to-human extrapolation approaches to independently estimate external exposure levels of AuNPs that cause minimal toxicity. Our results suggest that under the highest dosing level employed in existing animal studies (worst-case scenario), AuNPs coated with branched polyethylenimine (BPEI) would likely induce ∼90-100% cellular death, implying high cytotoxicity compared to risk prediction, and point of departure estimation of AuNP exposure for humans and illustrate an approach that could be applied to other NPs when sufficient data are available.

  1. Challenges of forest landscape modeling - simulating large landscapes and validating results

    Science.gov (United States)

    Hong S. He; Jian Yang; Stephen R. Shifley; Frank R. Thompson

    2011-01-01

    Over the last 20 years, we have seen a rapid development in the field of forest landscape modeling, fueled by both technological and theoretical advances. Two fundamental challenges have persisted since the inception of FLMs: (1) balancing realistic simulation of ecological processes at broad spatial and temporal scales with computing capacity, and (2) validating...

  2. Challenges of assessing fire and burn severity using field measures, remote sensing and modelling

    Science.gov (United States)

    Penelope Morgan; Robert E. Keane; Gregory K. Dillon; Theresa B. Jain; Andrew T. Hudak; Eva C. Karau; Pamela G. Sikkink; Zachery A. Holden; Eva K. Strand

    2014-01-01

    Comprehensive assessment of ecological change after fires have burned forests and rangelands is important if we are to understand, predict and measure fire effects. We highlight the challenges in effective assessment of fire and burn severity in the field and using both remote sensing and simulation models. We draw on diverse recent research for guidance on assessing...

  3. The Challenge of Forecasting the Onset and Development of Radiation Fog Using Mesoscale Atmospheric Models

    NARCIS (Netherlands)

    Steeneveld, G.J.; Ronda, R.J.; Holtslag, A.A.M.

    2015-01-01

    The numerical weather prediction of radiation fog is challenging, as many models typically show large biases for the timing of the onset and dispersal of the fog, as well as for its depth and liquid water content. To understand the role of physical processes, i.e. turbulence, radiation, land-surface

  4. Special Section: The third provenance challenge on using the open provenance model for interoperability

    NARCIS (Netherlands)

    Simmhan, Y; Groth, P.T.; Moreau, L

    2011-01-01

    The third provenance challenge was organized to evaluate the efficacy of the Open Provenance Model (OPM) in representing and sharing provenance with the goal of improving the specification. A data loading scientific workflow that ingests data files into a relational database for the Pan-STARRS sky

  5. An experimental Toxoplasma gondii dose response challenge model to study therapeutic or vaccine efficacy in cats

    NARCIS (Netherlands)

    Cornelissen, J.B.W.J.; Giessen, van der J.W.B.; Takumi, K.; Teunis, P.F.M.; Wisselink, H.J.

    2014-01-01

    High numbers of Toxoplasma gondii oocysts in the environment are a risk factor to humans. The environmental contamination might be reduced by vaccinating the definitive host, cats. An experimental challenge model is necessary to quantitatively assess the efficacy of a vaccine or drug treatment.

  6. From the Building to the Grid: An Energy Revolution and Modeling Challenge; Workshop Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Kroposki, B.; Komomua, C.; O' Malley, M.

    2013-01-01

    This report summarizes the workshop entitled: From the Building to the Grid: An Energy Revolution and Modeling Challenge. The first workshop was held May 1-2, 2012 on NREL's campus in Golden, Colorado. The second was held June 6-7, 2012 at the University College Dublin, in Dublin, Ireland.

  7. Modelling of vector hysteresis at macromagnetic scale: Open questions and challenges

    International Nuclear Information System (INIS)

    Cardelli, E.; Faba, A.

    2016-01-01

    After a short review of some experimental evidences the motivations that lead to the practical need of phenomenological modelling for the analysis of magnetic materials at macro-scale, and some challenging formulations are presented and discussed. Examples of practical applications are reported.

  8. Decision-Making in Agent-Based Models of Migration: State of the Art and Challenges.

    Science.gov (United States)

    Klabunde, Anna; Willekens, Frans

    We review agent-based models (ABM) of human migration with respect to their decision-making rules. The most prominent behavioural theories used as decision rules are the random utility theory, as implemented in the discrete choice model, and the theory of planned behaviour. We identify the critical choices that must be made in developing an ABM, namely the modelling of decision processes and social networks. We also discuss two challenges that hamper the widespread use of ABM in the study of migration and, more broadly, demography and the social sciences: (a) the choice and the operationalisation of a behavioural theory (decision-making and social interaction) and (b) the selection of empirical evidence to validate the model. We offer advice on how these challenges might be overcome.

  9. Challenges and priorities for modelling livestock health and pathogens in the context of climate change.

    Science.gov (United States)

    Özkan, Şeyda; Vitali, Andrea; Lacetera, Nicola; Amon, Barbara; Bannink, André; Bartley, Dave J; Blanco-Penedo, Isabel; de Haas, Yvette; Dufrasne, Isabelle; Elliott, John; Eory, Vera; Fox, Naomi J; Garnsworthy, Phil C; Gengler, Nicolas; Hammami, Hedi; Kyriazakis, Ilias; Leclère, David; Lessire, Françoise; Macleod, Michael; Robinson, Timothy P; Ruete, Alejandro; Sandars, Daniel L; Shrestha, Shailesh; Stott, Alistair W; Twardy, Stanislaw; Vanrobays, Marie-Laure; Ahmadi, Bouda Vosough; Weindl, Isabelle; Wheelhouse, Nick; Williams, Adrian G; Williams, Hefin W; Wilson, Anthony J; Østergaard, Søren; Kipling, Richard P

    2016-11-01

    Climate change has the potential to impair livestock health, with consequences for animal welfare, productivity, greenhouse gas emissions, and human livelihoods and health. Modelling has an important role in assessing the impacts of climate change on livestock systems and the efficacy of potential adaptation strategies, to support decision making for more efficient, resilient and sustainable production. However, a coherent set of challenges and research priorities for modelling livestock health and pathogens under climate change has not previously been available. To identify such challenges and priorities, researchers from across Europe were engaged in a horizon-scanning study, involving workshop and questionnaire based exercises and focussed literature reviews. Eighteen key challenges were identified and grouped into six categories based on subject-specific and capacity building requirements. Across a number of challenges, the need for inventories relating model types to different applications (e.g. the pathogen species, region, scale of focus and purpose to which they can be applied) was identified, in order to identify gaps in capability in relation to the impacts of climate change on animal health. The need for collaboration and learning across disciplines was highlighted in several challenges, e.g. to better understand and model complex ecological interactions between pathogens, vectors, wildlife hosts and livestock in the context of climate change. Collaboration between socio-economic and biophysical disciplines was seen as important for better engagement with stakeholders and for improved modelling of the costs and benefits of poor livestock health. The need for more comprehensive validation of empirical relationships, for harmonising terminology and measurements, and for building capacity for under-researched nations, systems and health problems indicated the importance of joined up approaches across nations. The challenges and priorities identified can

  10. Challenges of current hydraulic modeling with three examples; Herausforderungen des heutigen wasserbaulichen Versuchswesens mit drei Beispielen

    Energy Technology Data Exchange (ETDEWEB)

    De Cesare, Giovanni; Pfister, Michael; Daneshvari, Milad; Bieri, Martin [Ecole Polytechnique Federale de Lausanne (Switzerland). Lab. de Constructions Hydrauliques (EPFL-LCH)

    2012-07-01

    Most technical universities offering courses in civil engineering operate for meanwhile 100 years hydraulic laboratories. They investigate and optimize hydraulic structures related to dams, power plants and flood protection measures using physical modelling. These laboratories are usually fully booked today although this classical engineering approach was often predicted to disappear. The authors describe their experience and the new challenges in physical modelling, illustrated with three examples. (orig.)

  11. Asset transformation and the challenges to servitize a utility business model

    International Nuclear Information System (INIS)

    Helms, Thorsten

    2016-01-01

    The traditional energy utility business model is under pressure, and energy services are expected to play an important role for the energy transition. Experts and scholars argue that utilities need to innovate their business models, and transform from commodity suppliers to service providers. The transition from a product-oriented, capital-intensive business model based on tangible assets, towards a service-oriented, expense-intensive business model based on intangible assets may present great managerial and organizational challenges. Little research exists about such transitions for capital-intensive commodity providers, and particularly energy utilities, where the challenges to servitize are expected to be greatest. This qualitative paper explores the barriers to servitization within selected Swiss and German utility companies through a series of interviews with utility managers. One of them is ‘asset transformation’, the shift from tangible to intangible assets as major input factor for the value proposition, which is proposed as a driver for the complexity of business model transitions. Managers need to carefully manage those challenges, and find ways to operate both new service and established utility business models aside. Policy makers can support the transition of utilities through more favorable regulatory frameworks for energy services, and by supporting the exchange of knowledge in the industry. - Highlights: •The paper analyses the expected transformation of utilities into service-providers. •Service and utility business models possess very different attributes. •The former is based on intangible, the latter on tangible assets. •The transformation into a service-provider is related with great challenges. •Asset transformation is proposed as a barrier for business model innovation.

  12. Data Mining and Pattern Recognition Models for Identifying Inherited Diseases: Challenges and Implications

    OpenAIRE

    Iddamalgoda, Lahiru; Das, Partha S.; Aponso, Achala; Sundararajan, Vijayaraghava S.; Suravajhala, Prashanth; Valadi, Jayaraman K.

    2016-01-01

    Data mining and pattern recognition methods reveal interesting findings in genetic studies, especially on how the genetic makeup is associated with inherited diseases. Although researchers have proposed various data mining models for biomedical approaches, there remains a challenge in accurately prioritizing the single nucleotide polymorphisms (SNP) associated with the disease. In this commentary, we review the state-of-art data mining and pattern recognition models for identifying inherited ...

  13. Challenges for Knowledge Management in the Context of IT Global Sourcing Models Implementation

    OpenAIRE

    Perechuda , Kazimierz; Sobińska , Małgorzata

    2014-01-01

    Part 2: Models and Functioning of Knowledge Management; International audience; The article gives a literature overview of the current challenges connected with the implementation of the newest IT sourcing models. In the dynamic environment, organizations are required to build their competitive advantage not only on their own resources, but also on resources commissioned from external providers, accessed through various forms of sourcing, including the sourcing of IT services. This paper pres...

  14. Challenges of the Modeling Methods for Investigating the Interaction between the CNT and the Surrounding Polymer

    Directory of Open Access Journals (Sweden)

    Roham Rafiee

    2013-01-01

    Full Text Available The interaction between the carbon nanotubes (CNT and the polymer is a key factor for determining the mechanical, thermal, and electrical properties of the CNT/polymer nanocomposite. However, it is difficult to measure experimentally the interfacial bonding properties between the CNT and the surrounding polymer. Therefore, computational modeling is used to predict the interaction properties. Different scale models, from atomistic to continuum, are critically reviewed addressing the advantages, the disadvantages, and the future challenges. Various methods of improvement for measuring the interaction properties are described. Finally, it is concluded that the semicontinuum modeling may be the best candidate for modeling the interaction between the CNT and the polymer.

  15. Assessment and Challenges of Ligand Docking into Comparative Models of G-Protein Coupled Receptors

    DEFF Research Database (Denmark)

    Nguyen, E.D.; Meiler, J.; Norn, C.

    2013-01-01

    screening and to design and optimize drug candidates. However, low sequence identity between receptors, conformational flexibility, and chemical diversity of ligands present an enormous challenge to molecular modeling approaches. It is our hypothesis that rapid Monte-Carlo sampling of protein backbone...... extracellular loop. Furthermore, these models are consistently correlated with low Rosetta energy score. To predict their binding modes, ligand conformers of the 14 ligands co-crystalized with the GPCRs were docked against the top ranked comparative models. In contrast to the comparative models themselves...

  16. Modeling Acute Traumatic Hemorrhagic Shock Injury: Challenges and Guidelines for Preclinical Studies.

    Science.gov (United States)

    Tremoleda, Jordi L; Watts, Sarah A; Reynolds, Penny S; Thiemermann, Christoph; Brohi, Karim

    2017-12-01

    Trauma is responsible for a large proportion of the world's burden of disease, and is by far the biggest killer of young adults. Hemorrhage is the leading cause of preventable death and its effects are directly correlated with the incidence multi-organ failure in survivors. Trauma research is challenging due to patient heterogeneity, limited randomized controlled trials, and in vitro studies that fail to mimic the systemic injury response. Preclinical research remains essential for mechanistic and therapeutic discovery. Yet modeling the multifaceted nature of traumatic injury poses important experimental and welfare challenges associated with the onset of injury and prehospital and intra-operative care, the limited inter-species validation of coagulation profiles, the use of anesthesia/analgesia, and its impact on the systemic response to trauma; and the challenge of sustaining intensive care in recovery models. Proper model selection depends on the purpose of a given model and the criteria by which the experimental readouts will be clinically relevant. Such complexity warrants further refinement of experimental methodology and outcome measures to improve its clinical efficacy, while ensuring animal well-being. We review the experimental methodologies currently used for modeling traumatic hemorrhagic shock and addressing their impact on clinical translation. The aim of the review is to improve transparency and form a consensus when reporting methodology in trauma modeling.

  17. Current challenges in health economic modeling of cancer therapies: a research inquiry.

    Science.gov (United States)

    Miller, Jeffrey D; Foley, Kathleen A; Russell, Mason W

    2014-05-01

    The demand for economic models that evaluate cancer treatments is increasing, as healthcare decision makers struggle for ways to manage their budgets while providing the best care possible to patients with cancer. Yet, after nearly 2 decades of cultivating and refining techniques for modeling the cost-effectiveness and budget impact of cancer therapies, serious methodologic and policy challenges have emerged that question the adequacy of economic modeling as a sound decision-making tool in oncology. We sought to explore some of the contentious issues associated with the development and use of oncology economic models as informative tools in current healthcare decision-making. Our objective was to draw attention to these complex pharmacoeconomic concerns and to promote discussion within the oncology and health economics research communities. Using our combined expertise in health economics research and economic modeling, we structured our inquiry around the following 4 questions: (1) Are economic models adequately addressing questions relevant to oncology decision makers; (2) What are the methodologic limitations of oncology economic models; (3) What guidelines are followed for developing oncology economic models; and (4) Is the evolution of oncology economic modeling keeping pace with treatment innovation? Within the context of each of these questions, we discuss issues related to the technical limitations of oncology modeling, the availability of adequate data for developing models, and the problems with how modeling analyses and results are presented and interpreted. There is general acceptance that economic models are good, essential tools for decision-making, but the practice of oncology and its rapidly evolving technologies present unique challenges that make assessing and demonstrating value especially complex. There is wide latitude for improvement in oncology modeling methodologies and how model results are presented and interpreted. Complex technical and

  18. Evaluation of blood-brain barrier transport and CNS drug metabolism in diseased and control brain after intravenous L-DOPA in a unilateral rat model of Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Ravenstijn Paulien GM

    2012-02-01

    Full Text Available Abstract Background Changes in blood-brain barrier (BBB functionality have been implicated in Parkinson's disease. This study aimed to investigate BBB transport of L-DOPA transport in conjunction with its intra-brain conversion, in both control and diseased cerebral hemispheres in the unilateral rat rotenone model of Parkinson's disease. Methods In Lewis rats, at 14 days after unilateral infusion of rotenone into the medial forebrain bundle, L-DOPA was administered intravenously (10, 25 or 50 mg/kg. Serial blood samples and brain striatal microdialysates were analysed for L-DOPA, and the dopamine metabolites DOPAC and HVA. Ex-vivo brain tissue was analyzed for changes in tyrosine hydroxylase staining as a biomarker for Parkinson's disease severity. Data were analysed by population pharmacokinetic analysis (NONMEM to compare BBB transport of L-DOPA in conjunction with the conversion of L-DOPA into DOPAC and HVA, in control and diseased cerebral hemisphere. Results Plasma pharmacokinetics of L-DOPA could be described by a 3-compartmental model. In rotenone responders (71%, no difference in L-DOPA BBB transport was found between diseased and control cerebral hemisphere. However, in the diseased compared with the control side, basal microdialysate levels of DOPAC and HVA were substantially lower, whereas following L-DOPA administration their elimination rates were higher. Conclusions Parkinson's disease-like pathology, indicated by a huge reduction of tyrosine hydroxylase as well as by substantially reduced levels and higher elimination rates of DOPAC and HVA, does not result in changes in BBB transport of L-DOPA. Taking the results of this study and that of previous ones, it can be concluded that changes in BBB functionality are not a specific characteristic of Parkinson's disease, and cannot account for the decreased benefit of L-DOPA at later stages of Parkinson's disease.

  19. Next-Generation Climate Modeling Science Challenges for Simulation, Workflow and Analysis Systems

    Science.gov (United States)

    Koch, D. M.; Anantharaj, V. G.; Bader, D. C.; Krishnan, H.; Leung, L. R.; Ringler, T.; Taylor, M.; Wehner, M. F.; Williams, D. N.

    2016-12-01

    We will present two examples of current and future high-resolution climate-modeling research that are challenging existing simulation run-time I/O, model-data movement, storage and publishing, and analysis. In each case, we will consider lessons learned as current workflow systems are broken by these large-data science challenges, as well as strategies to repair or rebuild the systems. First we consider the science and workflow challenges to be posed by the CMIP6 multi-model HighResMIP, involving around a dozen modeling groups performing quarter-degree simulations, in 3-member ensembles for 100 years, with high-frequency (1-6 hourly) diagnostics, which is expected to generate over 4PB of data. An example of science derived from these experiments will be to study how resolution affects the ability of models to capture extreme-events such as hurricanes or atmospheric rivers. Expected methods to transfer (using parallel Globus) and analyze (using parallel "TECA" software tools) HighResMIP data for such feature-tracking by the DOE CASCADE project will be presented. A second example will be from the Accelerated Climate Modeling for Energy (ACME) project, which is currently addressing challenges involving multiple century-scale coupled high resolution (quarter-degree) climate simulations on DOE Leadership Class computers. ACME is anticipating production of over 5PB of data during the next 2 years of simulations, in order to investigate the drivers of water cycle changes, sea-level-rise, and carbon cycle evolution. The ACME workflow, from simulation to data transfer, storage, analysis and publication will be presented. Current and planned methods to accelerate the workflow, including implementing run-time diagnostics, and implementing server-side analysis to avoid moving large datasets will be presented.

  20. Challenges in land model representation of heat transfer in snow and frozen soils

    Science.gov (United States)

    Musselman, K. N.; Clark, M. P.; Nijssen, B.; Arnold, J.

    2017-12-01

    Accurate model simulations of soil thermal and moisture states are critical for realistic estimates of exchanges of energy, water, and biogeochemical fluxes at the land-atmosphere interface. In cold regions, seasonal snow-cover and organic soils form insulating barriers, modifying the heat and moisture exchange that would otherwise occur between mineral soils and the atmosphere. The thermal properties of these media are highly dynamic functions of mass, water and ice content. Land surface models vary in their representation of snow and soil processes, and thus in the treatment of insulation and heat exchange. For some models, recent development efforts have improved representation of heat transfer in cold regions, such as with multi-layer snow treatment, inclusion of soil freezing and organic soil properties, yet model deficiencies remain prevalent. We evaluate models that participated in the Protocol for the Analysis of Land Surface Models (PALS) Land Surface Model Benchmarking Evaluation Project (PLUMBER) experiment for proficiency in simulating heat transfer between the soil through the snowpack to the atmosphere. Using soil observations from cold region sites and a controlled experiment with Structure for Unifying Multiple Modeling Alternatives (SUMMA), we explore the impact of snow and soil model decisions and parameter values on heat transfer model skill. Specifically, we use SUMMA to mimic the spread of behaviors exhibited by the models that participated in PLUMBER. The experiment allows us to isolate relationships between model skill and process representation. The results are aimed to better understand existing model challenges and identify potential advances for cold region models.

  1. Addressing current challenges in cancer immunotherapy with mathematical and computational modelling.

    Science.gov (United States)

    Konstorum, Anna; Vella, Anthony T; Adler, Adam J; Laubenbacher, Reinhard C

    2017-06-01

    The goal of cancer immunotherapy is to boost a patient's immune response to a tumour. Yet, the design of an effective immunotherapy is complicated by various factors, including a potentially immunosuppressive tumour microenvironment, immune-modulating effects of conventional treatments and therapy-related toxicities. These complexities can be incorporated into mathematical and computational models of cancer immunotherapy that can then be used to aid in rational therapy design. In this review, we survey modelling approaches under the umbrella of the major challenges facing immunotherapy development, which encompass tumour classification, optimal treatment scheduling and combination therapy design. Although overlapping, each challenge has presented unique opportunities for modellers to make contributions using analytical and numerical analysis of model outcomes, as well as optimization algorithms. We discuss several examples of models that have grown in complexity as more biological information has become available, showcasing how model development is a dynamic process interlinked with the rapid advances in tumour-immune biology. We conclude the review with recommendations for modellers both with respect to methodology and biological direction that might help keep modellers at the forefront of cancer immunotherapy development. © 2017 The Author(s).

  2. Efficacy and Tolerability of Intravenous Levetiracetam in Children

    Directory of Open Access Journals (Sweden)

    Jose eAceves

    2013-08-01

    Full Text Available Intractable epilepsy in children poses a serious medical challenge. Acute repetitive seizures and status epilepticus leads to frequent emergency room visits and hospital admissions. Permanent neurological damage can occur if there is delay in treatment. It has been shown that these children continue to remain intractable even after acute seizure management with approved FDA agents. Intravenous levetiracetam, a second-generation anticonvulsant was approved by the FDA in 2006 in patients 16 years and older as an alternative when oral treatment is not an option. It has been shown that oral levetiracetam can be used in the treatment of status epilepticus and acute repetitive seizures. Data have been published showing that intravenous levetiracetam is safe and efficacious, and can be used in an acute inpatient setting. This current review will discuss the recent data about the safety and tolerability of intravenous levetiracetam in children and neonates, and emphasize the need for a larger prospective multicenter trial to prove the efficacy of this agent in acute seizure management.

  3. Fate of challenge schistosomula in the murine anti-schistosome vaccine model

    International Nuclear Information System (INIS)

    Von Lichtenberg, F.; Correa-Oliveira, R.; Sher, A.

    1985-01-01

    Mice exposed to irradiated cercariae of Schistosoma mansoni develop a partial resistance to subsequent parasite challenge. In this study the authors utilized histopathologic methods to investigate the fate of both the immunizing and challenge cercariae in C57BL/6J mice. After immunization by percutaneous infection, a large number of the 50 Kr irradiated organisms could be detected in tissue sections of lung. However, as early as 2 weeks after immunization, the majority of these schistosomula apparently had died, leaving residual inflammatory foci. The numbers of these foci then gradually declined during the next 4 weeks of examination. Cercarial challenge of mice vaccinated 4 weeks previously provoked an intense eosinophil-enriched inflammatory response in percutaneously exposed ear pinnae. Despite these pronounced tissue reactions, no evidence of significant parasite damage or attrition was detected in this migration site. In contrast, schistosomula arriving in the lungs of vaccinated mice produced a greater number of residual inflammatory foci than did larvae appearing in the lungs of normal mice. In addition, challenge schistosomula were cleared from the lungs of vaccinated mice at a slower rate than they were from the lungs of control mice. These observations suggest that the lung is a major site of parasite attrition for both immunizing and challenge infections in the mouse irradiated vaccine model

  4. Development of patient specific cardiovascular models predicting dynamics in response to orthostatic stress challenges

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.

    2013-01-01

    Physiological realistic models of the controlled cardiovascular system are constructed and validated against clinical data. Special attention is paid to the control of blood pressure, cerebral blood flow velocity, and heart rate during postural challenges, including sit-to-stand and head-up tilt....... This study describes development of patient specific models, and how sensitivity analysis and nonlinear optimization methods can be used to predict patient specific characteristics when analyzed using experimental data. Finally, we discuss how a given model can be used to understand physiological changes...

  5. Addressing challenges in single species assessments via a simple state-space assessment model

    DEFF Research Database (Denmark)

    Nielsen, Anders

    Single-species and age-structured fish stock assessments still remains the main tool for managing fish stocks. A simple state-space assessment model is presented as an alternative to (semi) deterministic procedures and the full parametric statistical catch at age models. It offers a solution...... to some of the key challenges of these models. Compared to the deterministic procedures it solves a list of problems originating from falsely assuming that age classified catches are known without errors and allows quantification of uncertainties of estimated quantities of interest. Compared to full...

  6. The prehospital intravenous access assessment: a prospective study on intravenous access failure and access delay in prehospital emergency medicine.

    Science.gov (United States)

    Prottengeier, Johannes; Albermann, Matthias; Heinrich, Sebastian; Birkholz, Torsten; Gall, Christine; Schmidt, Joachim

    2016-12-01

    Intravenous access in prehospital emergency care allows for early administration of medication and extended measures such as anaesthesia. Cannulation may, however, be difficult, and failure and resulting delay in treatment and transport may have negative effects on the patient. Therefore, our study aims to perform a concise assessment of the difficulties of prehospital venous cannulation. We analysed 23 candidate predictor variables on peripheral venous cannulations in terms of cannulation failure and exceedance of a 2 min time threshold. Multivariate logistic regression models were fitted for variables of predictive value (P0.6) of their respective receiver operating characteristic curve. A total of 762 intravenous cannulations were enroled. In all, 22% of punctures failed on the first attempt and 13% of punctures exceeded 2 min. Model selection yielded a three-factor model (vein visibility without tourniquet, vein palpability with tourniquet and insufficient ambient lighting) of fair accuracy for the prediction of puncture failure (AUC=0.76) and a structurally congruent model of four factors (failure model factors plus vein visibility with tourniquet) for the exceedance of the 2 min threshold (AUC=0.80). Our study offers a simple assessment to identify cases of difficult intravenous access in prehospital emergency care. Of the numerous factors subjectively perceived as possibly exerting influences on cannulation, only the universal - not exclusive to emergency care - factors of lighting, vein visibility and palpability proved to be valid predictors of cannulation failure and exceedance of a 2 min threshold.

  7. Rectal dihydroartemisinin versus intravenous quinine in the ...

    African Journals Online (AJOL)

    Rectal dihydroartemisinin versus intravenous quinine in the treatment of severe malaria: A randomised clinical trial. F Esamai, P Ayuo, W Owino-Ongor, J Rotich, A Ngindu, A Obala, F Ogaro, L Quoqiao, G Xingbo, L Guangqian ...

  8. INFECTIVE ENDOCARDITIS IN INTRAVENOUS DRUGS ABUSED PATIENT

    Directory of Open Access Journals (Sweden)

    E. Y. Ponomareva

    2014-07-01

    Full Text Available Three-year observation of acute tricuspid infective endocarditis in intravenous drug abused patient: diagnosis, clinical features, visceral lesions, the possibility of cardiac surgery and conservative treatment, outcome.

  9. INFECTIVE ENDOCARDITIS IN INTRAVENOUS DRUGS ABUSED PATIENT

    Directory of Open Access Journals (Sweden)

    E. Y. Ponomareva

    2011-01-01

    Full Text Available Three-year observation of acute tricuspid infective endocarditis in intravenous drug abused patient: diagnosis, clinical features, visceral lesions, the possibility of cardiac surgery and conservative treatment, outcome.

  10. Challenges in Modeling Disturbance Regimes and Their Impacts in Arctic and Boreal Ecosystems (Invited)

    Science.gov (United States)

    McGuire, A. D.; Rupp, T. S.; Kurz, W.

    2013-12-01

    Disturbances in arctic and boreal terrestrial ecosystems influence services provided by these ecosystems to society. In particular, changes in disturbance regimes in northern latitudes have uncertain consequences for the climate system. A major challenge for the scientific community is to develop the capability to predict how the frequency, severity and resultant impacts of disturbance regimes will change in response to future changes in climate projected for northern high latitudes. Here we compare what is known about drivers and impacts of wildfire, phytophagous insect pests, and thermokarst disturbance to illustrate the complexities in predicting future changes in disturbance regimes and their impacts in arctic and boreal regions. Much of the research on predicting fire has relied on the use of drivers related to fire weather. However, changes in vegetation, such as increases in broadleaf species, associated with intensified fire regimes have the potential to influence future fire regimes through negative feedbacks associated with reduced flammability. Phytophagous insect outbreaks have affected substantial portions of the boreal region in the past, but frequently the range of the tree host is larger than the range of the insect. There is evidence that a number of insect species are expanding their range in response to climate change. Major challenges to predicting outbreaks of phytophagous insects include modeling the effects of climate change on insect growth and maturation, winter mortality, plant host health, the synchrony of insect life stages and plant host phenology, and changes in the ranges of insect pests. Moreover, Earth System Models often simplify the representation of vegetation characteristics, e.g. the use of plant functional types, providing insufficient detail to link to insect population models. Thermokarst disturbance occurs when the thawing of ice-rich permafrost results in substantial ground subsidence. In the boreal forest, thermokarst can

  11. An Anti-Nicotinic Cognitive Challenge Model using Mecamylamine in Comparison with the Anti-Muscarinic Cognitive Challenge using Scopolamine

    NARCIS (Netherlands)

    Baakman, A. C.; Alvarez-jimenez, R.; Rissmann, R.; Klaassen, E. S.; Stevens, J.; Goulooze, S. C.; Burger, J.; Swart, E. L.; Van Gerven, J. M. A.; Groeneveld, G. J.

    Aims The muscarinic acetylcholine receptor antagonist scopolamine is often used for proof-of-pharmacology studies with pro-cognitive compounds. From a pharmacological point of view, it would seem more rational to use a nicotinic rather than a muscarinic anticholinergic challenge to prove

  12. Challenges of the expansive use of Building Information Modeling (BIM in construction projects

    Directory of Open Access Journals (Sweden)

    Hannele Kerosuo

    2015-06-01

    Full Text Available Building information modeling (BIM is an emerging modeling technology which challenges existing work procedures and practices in the construction industry. In this article we study the challenges, problems and potential expansions of BIM as a tool in the design, construction and operation of buildings. For this purpose the interfaces between different parties are examined in Finnish construction projects. The methodological approach of the study is cultural-historical activity theory, according to which a new artifact becomes a mediating instrument when the participatory subjects reconfigure the entire activity. The implementation of BIM is now spreading from the design activity to other phases of the construction projects, but its use is still limited in the projects' other three interfaces. BIM is an evolving set of software developed for various purposes which is locally 'combined' to fit the circumstances and capabilities of the stakeholders of the construction process.

  13. Intravenous iron-containing products: EMA procrastination.

    Science.gov (United States)

    2014-07-01

    A European reassessment has led to identical changes in the summaries of product characteristics (SPCs) for all intravenous iron-containing products: the risk of serious adverse effects is now highlighted, underlining the fact that intravenous iron-containing products should only be used when the benefits clearly outweigh the harms. Unfortunately, iron dextran still remains on the market despite a higher risk of hypersensitivity reactions than with iron sucrose.

  14. Seven challenges in modeling pathogen dynamics within-host and across scales

    OpenAIRE

    Julia R. Gog; Lorenzo Pellis; James L.N. Wood; Angela R. McLean; Nimalan Arinaminpathy; James O. Lloyd-Smith

    2015-01-01

    © 2014 The Authors. The population dynamics of infectious disease is a mature field in terms of theory and to some extent, application. However for microparasites, the theory and application of models of the dynamics within a single infected host is still an open field. Further, connecting across the scales - from cellular to host level, to population level - has potential to vastly improve our understanding of pathogen dynamics and evolution. Here, we highlight seven challenges in the follow...

  15. BARRIERS AND CHALLENGES OF BUILDING INFORMATION MODELLING IMPLEMENTATION IN JORDANIAN CONSTRUCTION INDUSTRY

    OpenAIRE

    Mohammed A.KA. AL-Btoush*, Ahmad Tarmizi Haron

    2017-01-01

    Construction companies are faced with the need to innovatively integrate the construction process and address project development challenges. One way of doing that is the integration of building information modelling (BIM) in the building design and development cycles. However, due to the lack of clear understanding and the absence of a holistic implementation guideline, many companies are unable to fully achieve BIM potentials or implement BIM in their project and building lifecycle. BIM imp...

  16. Data mining and Pattern Recognizing Models for Identifying Inherited Diseases: Challenges and Implications

    OpenAIRE

    Lahiru Iddamalgoda; Partha Sarathi Das; Partha Sarathi Das; Achala Aponso; Vijayaraghava Seshadri Sundararajan; Prashanth Suravajhala; Prashanth Suravajhala; Prashanth Suravajhala; Jayaraman K Valadi

    2016-01-01

    Data mining and pattern recognition methods reveal interesting findings in genetic studies, especially on how genetic makeup is associated with inherited diseases. Although researchers have proposed various data mining models for biomedical approaches, there remains a challenge in accurately determining the responsible genetic factors for prioritizing the single nucleotide polymorphisms (SNP) associated with the disease. In this commentary, we review the state-of-art data mining and pattern r...

  17. Implementing novel models of posttreatment care for cancer survivors: Enablers, challenges and recommendations.

    Science.gov (United States)

    Jefford, Michael; Kinnane, Nicole; Howell, Paula; Nolte, Linda; Galetakis, Spiridoula; Bruce Mann, Gregory; Naccarella, Lucio; Lai-Kwon, Julia; Simons, Katherine; Avery, Sharon; Thompson, Kate; Ashley, David; Haskett, Martin; Davies, Elise; Whitfield, Kathryn

    2015-12-01

    The American Society of Clinical Oncology and US Institute of Medicine emphasize the need to trial novel models of posttreatment care, and disseminate findings. In 2011, the Victorian State Government (Australia) established the Victorian Cancer Survivorship Program (VCSP), funding six 2-year demonstration projects, targeting end of initial cancer treatment. Projects considered various models, enrolling people of differing cancer types, age and residential areas. We sought to determine common enablers of success, as well as challenges/barriers. Throughout the duration of the projects, a formal "community of practice" met regularly to share experiences. Projects provided regular formal progress reports. An analysis framework was developed to synthesize key themes and identify critical enablers and challenges. Two external reviewers examined final project reports. Discussion with project teams clarified content. Survivors reported interventions to be acceptable, appropriate and effective. Strong clinical leadership was identified as a critical success factor. Workforce education was recognized as important. Partnerships with consumers, primary care and community organizations; risk stratified pathways with rapid re-access to specialist care; and early preparation for survivorship, self-management and shared care models supported positive project outcomes. Tailoring care to individual needs and predicted risks was supported. Challenges included: lack of valid assessment and prediction tools; limited evidence to support novel care models; workforce redesign; and effective engagement with community-based care and issues around survivorship terminology. The VCSP project outcomes have added to growing evidence around posttreatment care. Future projects should consider the identified enablers and challenges when designing and implementing survivorship care. © 2015 Wiley Publishing Asia Pty Ltd.

  18. Testing the Sarcocystis neurona vaccine using an equine protozoal myeloencephalitis challenge model.

    Science.gov (United States)

    Saville, William J A; Dubey, Jitender P; Marsh, Antoinette E; Reed, Stephen M; Keene, Robert O; Howe, Daniel K; Morrow, Jennifer; Workman, Jeffrey D

    2017-11-30

    Equine protozoal myeloencephalitis (EPM) is an important equine neurologic disorder, and treatments for the disease are often unrewarding. Prevention of the disease is the most important aspect for EPM, and a killed vaccine was previously developed for just that purpose. Evaluation of the vaccine had been hampered by lack of post vaccination challenge. The purpose of this study was to determine if the vaccine could prevent development of clinical signs after challenge with Sarcocystis neurona sporocysts in an equine challenge model. Seventy horses that were negative for antibodies to S. neurona and were neurologically normal were randomly assigned to vaccine or placebo groups and divided into short-term duration of immunity (study #1) and long-term duration of immunity (study #2) studies. S. neurona sporocysts used for the challenge were generated in the opossum/raccoon cycle isolate SN 37-R. Study #1 horses received an initial vaccination and a booster, and were challenged 34days post second vaccination. Study #2 horses received a vaccination and two boosters and were challenged 139days post third vaccination. All horses in study #1 developed neurologic signs (n=30) and there was no difference between the vaccinates and controls (P=0.7683). All but four horses in study #2 developed detectable neurologic deficits. The neurologic signs, although not statistically significant, were worse in the vaccinated horses (P=0.1559). In these two studies, vaccination with the S. neurona vaccine failed to prevent development of clinical neurologic deficits. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Models of user involvement in the mental health context: intentions and implementation challenges.

    Science.gov (United States)

    Storm, Marianne; Edwards, Adrian

    2013-09-01

    Patient-centered care, shared decision-making, patient participation and the recovery model are models of care which incorporate user involvement and patients' perspectives on their treatment and care. The aims of this paper are to examine these different care models and their association with user involvement in the mental health context and discuss some of the challenges associated with their implementation. The sources used are health policy documents and published literature and research on patient-centered care, shared decision-making, patient participation and recovery. The policy documents advocate that mental health services should be oriented towards patients' or users' needs, participation and involvement. These policies also emphasize recovery and integration of people with mental disorders in the community. However, these collaborative care models have generally been subject to limited empirical research about effectiveness. There are also challenges to implementation of the models in inpatient care. What evidence there is indicates tensions between patients' and providers' perspectives on treatment and care. There are issues related to risk and the person's capacity for user involvement, and concerns about what role patients themselves wish to play in decision-making. Lack of competence and awareness among providers are further issues. Further work on training, evaluation and implementation is needed to ensure that inpatient mental health services are adapting user oriented care models at all levels of services.

  20. Challenges in Soft Computing: Case Study with Louisville MSD CSO Modeling

    Science.gov (United States)

    Ormsbee, L.; Tufail, M.

    2005-12-01

    The principal constituents of soft computing include fuzzy logic, neural computing, evolutionary computation, machine learning, and probabilistic reasoning. There are numerous applications of these constituents (both individually and combination of two or more) in the area of water resources and environmental systems. These range from development of data driven models to optimal control strategies to assist in more informed and intelligent decision making process. Availability of data is critical to such applications and having scarce data may lead to models that do not represent the response function over the entire domain. At the same time, too much data has a tendency to lead to over-constraining of the problem. This paper will describe the application of a subset of these soft computing techniques (neural computing and genetic algorithms) to the Beargrass Creek watershed in Louisville, Kentucky. The application include development of inductive models as substitutes for more complex process-based models to predict water quality of key constituents (such as dissolved oxygen) and use them in an optimization framework for optimal load reductions. Such a process will facilitate the development of total maximum daily loads for the impaired water bodies in the watershed. Some of the challenges faced in this application include 1) uncertainty in data sets, 2) model application, and 3) development of cause-and-effect relationships between water quality constituents and watershed parameters through use of inductive models. The paper will discuss these challenges and how they affect the desired goals of the project.

  1. Numerical Modeling of Climate-Chemistry Connections: Recent Developments and Future Challenges

    Directory of Open Access Journals (Sweden)

    Patrick Jöckel

    2013-05-01

    Full Text Available This paper reviews the current state and development of different numerical model classes that are used to simulate the global atmospheric system, particularly Earth’s climate and climate-chemistry connections. The focus is on Chemistry-Climate Models. In general, these serve to examine dynamical and chemical processes in the Earth atmosphere, their feedback, and interaction with climate. Such models have been established as helpful tools in addition to analyses of observational data. Definitions of the global model classes are given and their capabilities as well as weaknesses are discussed. Examples of scientific studies indicate how numerical exercises contribute to an improved understanding of atmospheric behavior. There, the focus is on synergistic investigations combining observations and model results. The possible future developments and challenges are presented, not only from the scientific point of view but also regarding the computer technology and respective consequences for numerical modeling of atmospheric processes. In the future, a stronger cross-linkage of subject-specific scientists is necessary, to tackle the looming challenges. It should link the specialist discipline and applied computer science.

  2. The evolution of process-based hydrologic models: historical challenges and the collective quest for physical realism

    Science.gov (United States)

    Clark, M. P.; Nijssen, B.; Wood, A.; Mizukami, N.; Newman, A. J.

    2017-12-01

    The diversity in hydrologic models has historically led to great controversy on the "correct" approach to process-based hydrologic modeling, with debates centered on the adequacy of process parameterizations, data limitations and uncertainty, and computational constraints on model analysis. In this paper, we revisit key modeling challenges on requirements to (1) define suitable model equations, (2) define adequate model parameters, and (3) cope with limitations in computing power. We outline the historical modeling challenges, provide examples of modeling advances that address these challenges, and define outstanding research needs. We illustrate how modeling advances have been made by groups using models of different type and complexity, and we argue for the need to more effectively use our diversity of modeling approaches in order to advance our collective quest for physically realistic hydrologic models.

  3. Rescheduling nursing shifts: scoping the challenge and examining the potential of mathematical model based tools.

    Science.gov (United States)

    Clark, Alistair; Moule, Pam; Topping, Annie; Serpell, Martin

    2015-05-01

    To review research in the literature on nursing shift scheduling / rescheduling, and to report key issues identified in a consultation exercise with managers in four English National Health Service trusts to inform the development of mathematical tools for rescheduling decision-making. Shift rescheduling is unrecognised as an everyday time-consuming management task with different imperatives from scheduling. Poor rescheduling decisions can have quality, cost and morale implications. A systematic critical literature review identified rescheduling issues and existing mathematic modelling tools. A consultation exercise with nursing managers examined the complex challenges associated with rescheduling. Minimal research exists on rescheduling compared with scheduling. Poor rescheduling can result in greater disruption to planned nursing shifts and may impact negatively on the quality and cost of patient care, and nurse morale and retention. Very little research examines management challenges or mathematical modelling for rescheduling. Shift rescheduling is a complex and frequent management activity that is more challenging than scheduling. Mathematical modelling may have potential as a tool to support managers to minimise rescheduling disruption. The lack of specific methodological support for rescheduling that takes into account its complexity, increases the likelihood of harm for patients and stress for nursing staff and managers. © 2013 John Wiley & Sons Ltd.

  4. Model-based nonlinear control of hydraulic servo systems: Challenges, developments and perspectives

    Science.gov (United States)

    Yao, Jianyong

    2018-06-01

    Hydraulic servo system plays a significant role in industries, and usually acts as a core point in control and power transmission. Although linear theory-based control methods have been well established, advanced controller design methods for hydraulic servo system to achieve high performance is still an unending pursuit along with the development of modern industry. Essential nonlinearity is a unique feature and makes model-based nonlinear control more attractive, due to benefit from prior knowledge of the servo valve controlled hydraulic system. In this paper, a discussion for challenges in model-based nonlinear control, latest developments and brief perspectives of hydraulic servo systems are presented: Modelling uncertainty in hydraulic system is a major challenge, which includes parametric uncertainty and time-varying disturbance; some specific requirements also arise ad hoc difficulties such as nonlinear friction during low velocity tracking, severe disturbance, periodic disturbance, etc.; to handle various challenges, nonlinear solutions including parameter adaptation, nonlinear robust control, state and disturbance observation, backstepping design and so on, are proposed and integrated, theoretical analysis and lots of applications reveal their powerful capability to solve pertinent problems; and at the end, some perspectives and associated research topics (measurement noise, constraints, inner valve dynamics, input nonlinearity, etc.) in nonlinear hydraulic servo control are briefly explored and discussed.

  5. A novel porcine model of ventilator-associated pneumonia caused by oropharyngeal challenge with Pseudomonas aeruginosa.

    Science.gov (United States)

    Li Bassi, Gianluigi; Rigol, Montserrat; Marti, Joan-Daniel; Saucedo, Lina; Ranzani, Otavio T; Roca, Ignasi; Cabanas, Maria; Muñoz, Laura; Giunta, Valeria; Luque, Nestor; Rinaudo, Mariano; Esperatti, Mariano; Fernandez-Barat, Laia; Ferrer, Miquel; Vila, Jordi; Ramirez, Jose; Torres, Antoni

    2014-05-01

    Animal models of ventilator-associated pneumonia (VAP) in primates, sheep, and pigs differ in the underlying pulmonary injury, etiology, bacterial inoculation methods, and time to onset. The most common ovine and porcine models do not reproduce the primary pathogenic mechanism of the disease, through the aspiration of oropharyngeal pathogens, or the most prevalent human etiology. Herein the authors characterize a novel porcine model of VAP due to aspiration of oropharyngeal secretions colonized by Pseudomonas aeruginosa. Ten healthy pigs were intubated, positioned in anti-Trendelenburg, and mechanically ventilated for 72 h. Three animals did not receive bacterial challenge, whereas in seven animals, a P. aeruginosa suspension was instilled into the oropharynx. Tracheal aspirates were cultured and respiratory mechanics were recorded. On autopsy, lobar samples were obtained to corroborate VAP through microbiological and histological studies. In animals not challenged, diverse bacterial colonization of the airways was found and monolobar VAP rarely developed. In animals with P. aeruginosa challenge, colonization of tracheal secretion increased up to 6.39 ± 0.34 log colony-forming unit (cfu)/ml (P VAP was confirmed in six of seven pigs, in 78% of the cases developed in the dependent lung segments (right medium and lower lobes, P = 0.032). The static respiratory system elastance worsened to 41.5 ± 5.8 cm H2O/l (P = 0.001). The authors devised a VAP model caused by aspiration of oropharyngeal P. aeruginosa, a frequent causative pathogen of human VAP. The model also overcomes the practical and legislative limitations associated with the use of primates. The authors' model could be employed to study pathophysiologic mechanisms, as well as novel diagnostic/preventive strategies.

  6. Entering new fields of simulation application - challenges faced in simulation modelling of stroke systems

    NARCIS (Netherlands)

    van der Zee, D.J.; Monks, T.; Lahr, Maarten; Luijckx, Gert Jan; Buskens, Erik; Anagnostou, Anastasia; Hoad, Katy; Kunc, Martin

    2016-01-01

    Stroke is a major cause of death and long-term disability world-wide. To improve functional outcome treatment with intravenous tissue plasminogen activator (tPA) is the most effective medical treatment for acute brain infarction within 4.5 hours after the onset of stroke symptoms. Unfortunately, tPA

  7. Challenges Handling Magnetospheric and Ionospheric Signals in Internal Geomagnetic Field Modelling

    DEFF Research Database (Denmark)

    Finlay, Chris; Lesur, V.; Thébault, E.

    2017-01-01

    systems in the ionosphere and magnetosphere. In order to fully exploit magnetic data to probe the physical properties and dynamics of the Earth’s interior, field models with suitable treatments of external sources, and their associated induced signals, are essential. Here we review the methods presently......-by-track analysis to characterize magnetospheric field fluctuations, differences in internal field models that result from alternative treatments of the quiet-time ionospheric field, and challenges associated with rapidly changing, but spatially correlated, magnetic signatures of polar cap current systems. Possible...

  8. The big challenges in modeling human and environmental well-being.

    Science.gov (United States)

    Tuljapurkar, Shripad

    2016-01-01

    This article is a selective review of quantitative research, historical and prospective, that is needed to inform sustainable development policy. I start with a simple framework to highlight how demography and productivity shape human well-being. I use that to discuss three sets of issues and corresponding challenges to modeling: first, population prehistory and early human development and their implications for the future; second, the multiple distinct dimensions of human and environmental well-being and the meaning of sustainability; and, third, inequality as a phenomenon triggered by development and models to examine changing inequality and its consequences. I conclude with a few words about other important factors: political, institutional, and cultural.

  9. Redesigning models of patient care delivery and organisation: building collegial generosity in response to workplace challenges.

    Science.gov (United States)

    Chiarella, E Mary

    2007-04-01

    This case study describes the New South Wales Nursing and Midwifery Office (NaMO) Models of Care Project, a project designed to identify, encourage and disseminate innovations in nursing care organisation and delivery. The project is a 4-year action research project, using a range of interactive engagements including workshops, seminars, questionnaires and websites to achieve the goals. This case study briefly describes the main stimuli for review and redesign of models of care identified through analysis of the clinicians' presentations, and explores the range of responses to the workplace challenges.

  10. Modelling Marine Sediment Biogeochemistry: Current Knowledge Gaps, Challenges, and Some Methodological Advice for Advancement

    Directory of Open Access Journals (Sweden)

    Gennadi Lessin

    2018-02-01

    Full Text Available The benthic environment is a crucial component of marine systems in the provision of ecosystem services, sustaining biodiversity and in climate regulation, and therefore important to human society. With the contemporary increase in computational power, model resolution and technological improvements in quality and quantity of benthic data, it is necessary to ensure that benthic systems are appropriately represented in coupled benthic-pelagic biogeochemical and ecological modelling studies. In this paper we focus on five topical challenges related to various aspects of modelling benthic environments: organic matter reactivity, dynamics of benthic-pelagic boundary layer, microphytobenthos, biological transport and small-scale heterogeneity, and impacts of episodic events. We discuss current gaps in their understanding and indicate plausible ways ahead. Further, we propose a three-pronged approach for the advancement of benthic and benthic-pelagic modelling, essential for improved understanding, management and prediction of the marine environment. This includes: (A development of a traceable and hierarchical framework for benthic-pelagic models, which will facilitate integration among models, reduce risk of bias, and clarify model limitations; (B extended cross-disciplinary approach to promote effective collaboration between modelling and empirical scientists of various backgrounds and better involvement of stakeholders and end-users; (C a common vocabulary for terminology used in benthic modelling, to promote model development and integration, and also to enhance mutual understanding.

  11. Biosignature for airway inflammation in a house dust mite-challenged murine model of allergic asthma

    Directory of Open Access Journals (Sweden)

    Hadeesha Piyadasa

    2016-02-01

    Full Text Available House dust mite (HDM challenge is commonly used in murine models of allergic asthma for preclinical pathophysiological studies. However, few studies define objective readouts or biomarkers in this model. In this study we characterized immune responses and defined molecular markers that are specifically altered after HDM challenge. In this murine model, we used repeated HDM challenge for two weeks which induced hallmarks of allergic asthma seen in humans, including airway hyper-responsiveness (AHR and elevated levels of circulating total and HDM-specific IgE and IgG1. Kinetic studies showed that at least 24 h after last HDM challenge results in significant AHR along with eosinophil infiltration in the lungs. Histologic assessment of lung revealed increased epithelial thickness and goblet cell hyperplasia, in the absence of airway wall collagen deposition, suggesting ongoing tissue repair concomitant with acute allergic lung inflammation. Thus, this model may be suitable to delineate airway inflammation processes that precede airway remodeling and development of fixed airway obstruction. We observed that a panel of cytokines e.g. IFN-γ, IL-1β, IL-4, IL-5, IL-6, KC, TNF-α, IL-13, IL-33, MDC and TARC were elevated in lung tissue and bronchoalveolar fluid, indicating local lung inflammation. However, levels of these cytokines remained unchanged in serum, reflecting lack of systemic inflammation in this model. Based on these findings, we further monitored the expression of 84 selected genes in lung tissues by quantitative real-time PCR array, and identified 31 mRNAs that were significantly up-regulated in lung tissue from HDM-challenged mice. These included genes associated with human asthma (e.g. clca3, ear11, il-13, il-13ra2, il-10, il-21, arg1 and chia1 and leukocyte recruitment in the lungs (e.g. ccl11, ccl12 and ccl24. This study describes a biosignature to enable broad and systematic interrogation of molecular mechanisms and intervention

  12. Model Based Reasoning by Introductory Students When Analyzing Earth Systems and Societal Challenges

    Science.gov (United States)

    Holder, L. N.; Herbert, B. E.

    2014-12-01

    Understanding how students use their conceptual models to reason about societal challenges involving societal issues such as natural hazard risk assessment, environmental policy and management, and energy resources can improve instructional activity design that directly impacts student motivation and literacy. To address this question, we created four laboratory exercises for an introductory physical geology course at Texas A&M University that engages students in authentic scientific practices by using real world problems and issues that affect societies based on the theory of situated cognition. Our case-study design allows us to investigate the various ways that students utilize model based reasoning to identify and propose solutions to societally relevant issues. In each of the four interventions, approximately 60 students in three sections of introductory physical geology were expected to represent and evaluate scientific data, make evidence-based claims about the data trends, use those claims to express conceptual models, and use their models to analyze societal challenges. Throughout each step of the laboratory exercise students were asked to justify their claims, models, and data representations using evidence and through the use of argumentation with peers. Cognitive apprenticeship was the foundation for instruction used to scaffold students so that in the first exercise they are given a partially completed model and in the last exercise students are asked to generate a conceptual model on their own. Student artifacts, including representation of earth systems, representation of scientific data, verbal and written explanations of models and scientific arguments, and written solutions to specific societal issues or environmental problems surrounding earth systems, were analyzed through the use of a rubric that modeled authentic expertise and students were sorted into three categories. Written artifacts were examined to identify student argumentation and

  13. Using natural selection and optimization for smarter vegetation models - challenges and opportunities

    Science.gov (United States)

    Franklin, Oskar; Han, Wang; Dieckmann, Ulf; Cramer, Wolfgang; Brännström, Åke; Pietsch, Stephan; Rovenskaya, Elena; Prentice, Iain Colin

    2017-04-01

    Dynamic global vegetation models (DGVMs) are now indispensable for understanding the biosphere and for estimating the capacity of ecosystems to provide services. The models are continuously developed to include an increasing number of processes and to utilize the growing amounts of observed data becoming available. However, while the versatility of the models is increasing as new processes and variables are added, their accuracy suffers from the accumulation of uncertainty, especially in the absence of overarching principles controlling their concerted behaviour. We have initiated a collaborative working group to address this problem based on a 'missing law' - adaptation and optimization principles rooted in natural selection. Even though this 'missing law' constrains relationships between traits, and therefore can vastly reduce the number of uncertain parameters in ecosystem models, it has rarely been applied to DGVMs. Our recent research have shown that optimization- and trait-based models of gross primary production can be both much simpler and more accurate than current models based on fixed functional types, and that observed plant carbon allocations and distributions of plant functional traits are predictable with eco-evolutionary models. While there are also many other examples of the usefulness of these and other theoretical principles, it is not always straight-forward to make them operational in predictive models. In particular on longer time scales, the representation of functional diversity and the dynamical interactions among individuals and species presents a formidable challenge. Here we will present recent ideas on the use of adaptation and optimization principles in vegetation models, including examples of promising developments, but also limitations of the principles and some key challenges.

  14. Scale effect challenges in urban hydrology highlighted with a distributed hydrological model

    Science.gov (United States)

    Ichiba, Abdellah; Gires, Auguste; Tchiguirinskaia, Ioulia; Schertzer, Daniel; Bompard, Philippe; Ten Veldhuis, Marie-Claire

    2018-01-01

    Hydrological models are extensively used in urban water management, development and evaluation of future scenarios and research activities. There is a growing interest in the development of fully distributed and grid-based models. However, some complex questions related to scale effects are not yet fully understood and still remain open issues in urban hydrology. In this paper we propose a two-step investigation framework to illustrate the extent of scale effects in urban hydrology. First, fractal tools are used to highlight the scale dependence observed within distributed data input into urban hydrological models. Then an intensive multi-scale modelling work is carried out to understand scale effects on hydrological model performance. Investigations are conducted using a fully distributed and physically based model, Multi-Hydro, developed at Ecole des Ponts ParisTech. The model is implemented at 17 spatial resolutions ranging from 100 to 5 m. Results clearly exhibit scale effect challenges in urban hydrology modelling. The applicability of fractal concepts highlights the scale dependence observed within distributed data. Patterns of geophysical data change when the size of the observation pixel changes. The multi-scale modelling investigation confirms scale effects on hydrological model performance. Results are analysed over three ranges of scales identified in the fractal analysis and confirmed through modelling. This work also discusses some remaining issues in urban hydrology modelling related to the availability of high-quality data at high resolutions, and model numerical instabilities as well as the computation time requirements. The main findings of this paper enable a replacement of traditional methods of model calibration by innovative methods of model resolution alteration based on the spatial data variability and scaling of flows in urban hydrology.

  15. Intravenous injection of ioxilan, iohexol and diatrizoate

    International Nuclear Information System (INIS)

    Thomsen, H.S.; Dorph, S.; Mygind, T.; Sovak, M.; Nielsen, H.; Rygaard, H.; Larsen, S.; Skaarup, P.; Hemmingsen, L.; Holm, J.

    1988-01-01

    Effects of intravenous ioxilan, a new third generation non-ionic contrast medium, diatrizoate, iohexol and saline on urine profiles were compared. Albumin, glucose, sodium, phosphate, and the enzymes NAG, LDH and GGT were followed in 24 normal rats over 7 days. Diatrizoate significantly affected all profile components during the first two hours. Albuminuria was significantly greater after diatrizoate than after iohexol or ioxilan, and excretion of glucose, LDH and GGT was significantly higher than after ioxilan. Both iohexol and ioxilan increased the excretion of albumin, LDH and GGT, while iohexol also significantly increased excretion of glucose and sodium. There was a greater excretion of glucose and GGT after iohexol than after ioxilan. Saline did not induce any changes. At day 7, serum sodium, urea, creatinine, and albumin were normal for all test substances, and kidney histology revealed no difference between the groups of animals. It is thus concluded that both high osmolar ionic and low osmolar non-ionic contrast media may cause temporary glomerular and tubular dysfunction in rats. In this model, the kidney is affected most by diatrizoate, less by iohexol, and least by ioxilan. (orig.)

  16. Experiences in applying Bayesian integrative models in interdisciplinary modeling: the computational and human challenges

    DEFF Research Database (Denmark)

    Kuikka, Sakari; Haapasaari, Päivi Elisabet; Helle, Inari

    2011-01-01

    We review the experience obtained in using integrative Bayesian models in interdisciplinary analysis focusing on sustainable use of marine resources and environmental management tasks. We have applied Bayesian models to both fisheries and environmental risk analysis problems. Bayesian belief...... be time consuming and research projects can be difficult to manage due to unpredictable technical problems related to parameter estimation. Biology, sociology and environmental economics have their own scientific traditions. Bayesian models are becoming traditional tools in fisheries biology, where...

  17. Seven challenges for model-driven data collection in experimental and observational studies

    Directory of Open Access Journals (Sweden)

    J. Lessler

    2015-03-01

    Full Text Available Infectious disease models are both concise statements of hypotheses and powerful techniques for creating tools from hypotheses and theories. As such, they have tremendous potential for guiding data collection in experimental and observational studies, leading to more efficient testing of hypotheses and more robust study designs. In numerous instances, infectious disease models have played a key role in informing data collection, including the Garki project studying malaria, the response to the 2009 pandemic of H1N1 influenza in the United Kingdom and studies of T-cell immunodynamics in mammals. However, such synergies remain the exception rather than the rule; and a close marriage of dynamic modeling and empirical data collection is far from the norm in infectious disease research. Overcoming the challenges to using models to inform data collection has the potential to accelerate innovation and to improve practice in how we deal with infectious disease threats.

  18. Advantages and challenges of using physics curricula as a model for reforming an undergraduate biology course.

    Science.gov (United States)

    Donovan, D A; Atkins, L J; Salter, I Y; Gallagher, D J; Kratz, R F; Rousseau, J V; Nelson, G D

    2013-06-01

    We report on the development of a life sciences curriculum, targeted to undergraduate students, which was modeled after a commercially available physics curriculum and based on aspects of how people learn. Our paper describes the collaborative development process and necessary modifications required to apply a physics pedagogical model in a life sciences context. While some approaches were easily adapted, others provided significant challenges. Among these challenges were: representations of energy, introducing definitions, the placement of Scientists' Ideas, and the replicability of data. In modifying the curriculum to address these challenges, we have come to see them as speaking to deeper differences between the disciplines, namely that introductory physics--for example, Newton's laws, magnetism, light--is a science of pairwise interaction, while introductory biology--for example, photosynthesis, evolution, cycling of matter in ecosystems--is a science of linked processes, and we suggest that this is how the two disciplines are presented in introductory classes. We illustrate this tension through an analysis of our adaptations of the physics curriculum for instruction on the cycling of matter and energy; we show that modifications of the physics curriculum to address the biological framework promotes strong gains in student understanding of these topics, as evidenced by analysis of student work.

  19. Cloud service performance evaluation: status, challenges, and opportunities – a survey from the system modeling perspective

    Directory of Open Access Journals (Sweden)

    Qiang Duan

    2017-05-01

    Full Text Available With rapid advancement of Cloud computing and networking technologies, a wide spectrum of Cloud services have been developed by various providers and utilized by numerous organizations as indispensable ingredients of their information systems. Cloud service performance has a significant impact on performance of the future information infrastructure. Thorough evaluation on Cloud service performance is crucial and beneficial to both service providers and consumers; thus forming an active research area. Some key technologies for Cloud computing, such as virtualization and the Service-Oriented Architecture (SOA, bring in special challenges to service performance evaluation. A tremendous amount of effort has been put by the research community to address these challenges and exciting progress has been made. Among the work on Cloud performance analysis, evaluation approaches developed with a system modeling perspective play an important role. However, related works have been reported in different sections of the literature; thus lacking a big picture that shows the latest status of this area. The objectives of this article is to present a survey that reflects the state of the art of Cloud service performance evaluation from the system modeling perspective. This articles also examines open issues and challenges to the surveyed evaluation approaches and identifies possible opportunities for future research in this important field.

  20. GEM-CEDAR Challenge: Poynting Flux at DMSP and Modeled Joule Heat

    Science.gov (United States)

    Rastaetter, Lutz; Shim, Ja Soon; Kuznetsova, Maria M.; Kilcommons, Liam M.; Knipp, Delores J.; Codrescu, Mihail; Fuller-Rowell, Tim; Emery, Barbara; Weimer, Daniel R.; Cosgrove, Russell; hide

    2016-01-01

    Poynting flux into the ionosphere measures the electromagnetic energy coming from the magnetosphere. This energy flux can vary greatly between quiet times and geomagnetic active times. As part of the Geospace Environment Modeling-coupling energetics and dynamics of atmospheric regions modeling challenge, physics-based models of the 3-D ionosphere and ionospheric electrodynamics solvers of magnetosphere models that specify Joule heat and empirical models specifying Poynting flux were run for six geomagnetic storm events of varying intensity. We compared model results with Poynting flux values along the DMSP-15 satellite track computed from ion drift meter and magnetic field observations. Although being a different quantity, Joule heat can in practice be correlated to incoming Poynting flux because the energy is dissipated primarily in high latitudes where Poynting flux is being deposited. Within the physics-based model group, we find mixed results with some models overestimating Joule heat and some models agreeing better with observed Poynting flux rates as integrated over auroral passes. In contrast, empirical models tend to underestimate integrated Poynting flux values. Modeled Joule heat or Poynting flux patterns often resemble the observed Poynting flux patterns on a large scale, but amplitudes can differ by a factor of 2 or larger due to the highly localized nature of observed Poynting flux deposition that is not captured by the models. In addition, the positioning of modeled patterns appear to be randomly shifted against the observed Poynting flux energy input. This study is the first to compare Poynting flux and Joule heat in a large variety of models of the ionosphere.

  1. The big data-big model (BDBM) challenges in ecological research

    Science.gov (United States)

    Luo, Y.

    2015-12-01

    The field of ecology has become a big-data science in the past decades due to development of new sensors used in numerous studies in the ecological community. Many sensor networks have been established to collect data. For example, satellites, such as Terra and OCO-2 among others, have collected data relevant on global carbon cycle. Thousands of field manipulative experiments have been conducted to examine feedback of terrestrial carbon cycle to global changes. Networks of observations, such as FLUXNET, have measured land processes. In particular, the implementation of the National Ecological Observatory Network (NEON), which is designed to network different kinds of sensors at many locations over the nation, will generate large volumes of ecological data every day. The raw data from sensors from those networks offer an unprecedented opportunity for accelerating advances in our knowledge of ecological processes, educating teachers and students, supporting decision-making, testing ecological theory, and forecasting changes in ecosystem services. Currently, ecologists do not have the infrastructure in place to synthesize massive yet heterogeneous data into resources for decision support. It is urgent to develop an ecological forecasting system that can make the best use of multiple sources of data to assess long-term biosphere change and anticipate future states of ecosystem services at regional and continental scales. Forecasting relies on big models that describe major processes that underlie complex system dynamics. Ecological system models, despite great simplification of the real systems, are still complex in order to address real-world problems. For example, Community Land Model (CLM) incorporates thousands of processes related to energy balance, hydrology, and biogeochemistry. Integration of massive data from multiple big data sources with complex models has to tackle Big Data-Big Model (BDBM) challenges. Those challenges include interoperability of multiple

  2. Intravenous Iron Carboxymaltose as a Potential Therapeutic in Anemia of Inflammation.

    Directory of Open Access Journals (Sweden)

    Niklas Lofruthe

    Full Text Available Intravenous iron supplementation is an effective therapy in iron deficiency anemia (IDA, but controversial in anemia of inflammation (AI. Unbound iron can be used by bacteria and viruses for their replication and enhance the inflammatory response. Nowadays available high molecular weight iron complexes for intravenous iron substitution, such as ferric carboxymaltose, might be useful in AI, as these pharmaceuticals deliver low doses of free iron over a prolonged period of time. We tested the effects of intravenous iron carboxymaltose in murine AI: Wild-type mice were exposed to the heat-killed Brucella abortus (BA model and treated with or without high molecular weight intravenous iron. 4h after BA injection followed by 2h after intravenous iron treatment, inflammatory cytokines were upregulated by BA, but not enhanced by iron treatment. In long term experiments, mice were fed a regular or an iron deficient diet and then treated with intravenous iron or saline 14 days after BA injection. Iron treatment in mice with BA-induced AI was effective 24h after iron administration. In contrast, mice with IDA (on iron deficiency diet prior to BA-IA required 7d to recover from AI. In these experiments, inflammatory markers were not further induced in iron-treated compared to vehicle-treated BA-injected mice. These results demonstrate that intravenous iron supplementation effectively treated the murine BA-induced AI without further enhancement of the inflammatory response. Studies in humans have to reveal treatment options for AI in patients.

  3. Challenges in Slug Modeling and Control for Offshore Oil and Gas Productions

    DEFF Research Database (Denmark)

    Pedersen, Simon; Løhndorf, Petar Durdevic; Yang, Zhenyu

    2017-01-01

    The upstream offshore multi-phase well-pipeline-riser installations are facing huge challenges related to slugging flow: An unstable flow regime where the flow rates, pressures and temperatures oscillate in the multi-phase pipelines. One typical severe slug is induced by vertical wells or risers...... most models require specific facility and operating data which, unfortunately, often is not available from most offshore installations. Anti-slug control have been investigated for several decades in oil & gas industry, but many of these existing methods suffer the consequent risk of simultaneously...... reducing the oil & gas production. This paper concludes that slug is a well defined phenomenon, but even though it has been investigated for several decades the current anti-slug control methods still have problems related to robustness. It is predicted that slug-induced challenges will be even more severe...

  4. Challenges in Modelling and Control of Offshore De-oiling Hydrocyclone Systems

    DEFF Research Database (Denmark)

    Løhndorf, Petar Durdevic; Pedersen, Simon; Yang, Zhenyu

    2017-01-01

    , and alternatively this task imposes a number of key control challenges. Specifically, there is much research to be performed in the direction of dynamic modelling and control of de-oiling hydrocyclone systems. The current solutions rely heavily on empirical trial-and-error approaches. This paper gives a brief......Offshore de-oiling installations are facing an increasing challenge with regards to removing oil residuals from produced water prior to discharge into the ocean. The de-oiling of produced water is initially achieved in the primary separation processes using gravity-based multi-phase separators...... in the produced water before it can be discharged into the ocean. The popularity of hydrocyclone technology in the offshore oil and gas industry is mainly due to its rugged design and low maintenance requirements. However, to operate and control this type of system in an efficient way is far less simple...

  5. Microglia Transcriptome Changes in a Model of Depressive Behavior after Immune Challenge.

    Directory of Open Access Journals (Sweden)

    Dianelys Gonzalez-Pena

    Full Text Available Depression symptoms following immune response to a challenge have been reported after the recovery from sickness. A RNA-Seq study of the dysregulation of the microglia transcriptome in a model of inflammation-associated depressive behavior was undertaken. The transcriptome of microglia from mice at day 7 after Bacille Calmette Guérin (BCG challenge was compared to that from unchallenged Control mice and to the transcriptome from peripheral macrophages from the same mice. Among the 562 and 3,851 genes differentially expressed between BCG-challenged and Control mice in microglia and macrophages respectively, 353 genes overlapped between these cells types. Among the most differentially expressed genes in the microglia, serum amyloid A3 (Saa3 and cell adhesion molecule 3 (Cadm3 were over-expressed and coiled-coil domain containing 162 (Ccdc162 and titin-cap (Tcap were under-expressed in BCG-challenged relative to Control. Many of the differentially expressed genes between BCG-challenged and Control mice were associated with neurological disorders encompassing depression symptoms. Across cell types, S100 calcium binding protein A9 (S100A9, interleukin 1 beta (Il1b and kynurenine 3-monooxygenase (Kmo were differentially expressed between challenged and control mice. Immune response, chemotaxis, and chemokine activity were among the functional categories enriched by the differentially expressed genes. Functional categories enriched among the 9,117 genes differentially expressed between cell types included leukocyte regulation and activation, chemokine and cytokine activities, MAP kinase activity, and apoptosis. More than 200 genes exhibited alternative splicing events between cell types including WNK lysine deficient protein kinase 1 (Wnk1 and microtubule-actin crosslinking factor 1(Macf1. Network visualization revealed the capability of microglia to exhibit transcriptome dysregulation in response to immune challenge still after resolution of sickness

  6. Development of a prediction model of severe reaction in boiled egg challenges.

    Science.gov (United States)

    Sugiura, Shiro; Matsui, Teruaki; Nakagawa, Tomoko; Sasaki, Kemal; Nakata, Joon; Kando, Naoyuki; Ito, Komei

    2016-07-01

    We have proposed a new scoring system (Anaphylaxis SCoring Aichi: ASCA) for a quantitative evaluation of the anaphylactic reaction that is observed in an oral food challenge (OFC). Furthermore, the TS/Pro (Total Score of ASCA/cumulative protein dose) can be a marker to represent the overall severity of a food allergy. We aimed to develop a prediction model for a severe allergic reaction that is provoked in a boiled egg white challenge. We used two separate datasets to develop and validate the prediction model, respectively. The development dataset included 198 OFCs, that tested positive. The validation dataset prospectively included 140 consecutive OFCs, irrespective of the result. A 'severe reaction' was defined as a TS/Pro higher than 31 (the median score of the development dataset). A multivariate logistic regression analysis was performed to identify the factors associated with a severe reaction and develop the prediction model. The following four factors were independently associated with a severe reaction: ovomucoid specific IgE class (OM-sIgE: 0-6), aged 5 years or over, a complete avoidance of egg, and a total IgE prediction model. The model showed good discrimination in a receiver operating characteristic analysis; area under the curve (AUC) = 0.84 in development dataset, AUC = 0.85 in validation dataset. The prediction model significantly improved the AUC in both datasets compared to OM-sIgE alone. This simple scoring prediction model was useful for avoiding risky OFC. Copyright © 2016 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

  7. Intravenous cidofovir for resistant cutaneous warts in a patient with psoriasis treated with monoclonal antibodies.

    LENUS (Irish Health Repository)

    McAleer, M A

    2012-02-01

    Human papilloma virus is a common and often distressing cutaneous disease. It can be therapeutically challenging, especially in immunocompromised patients. We report a case of recalcitrant cutaneous warts that resolved with intravenous cidofovir treatment. The patient was immunocompromised secondary to monoclonal antibody therapy for psoriasis.

  8. Iris abscess a rare presentation of intravenous drug abuse associated Candida endophthalmitis

    Directory of Open Access Journals (Sweden)

    Jonathan Pierce

    2016-12-01

    Conclusions and importance: An iris abscess is a rare clinical presentation of intravenous drug use-associated endogenous endophthalmitis and as a result may present a diagnostic challenge as it requires a high level of clinical suspicion and a detailed social history to elicit the drug abuse. Early diagnosis and aggressive therapy is the key to better visual outcomes in these patients.

  9. Challenges to Applying a Metamodel for Groundwater Flow Beyond Underlying Numerical Model Boundaries

    Science.gov (United States)

    Reeves, H. W.; Fienen, M. N.; Feinstein, D.

    2015-12-01

    Metamodels of environmental behavior offer opportunities for decision support, adaptive management, and increased stakeholder engagement through participatory modeling and model exploration. Metamodels are derived from calibrated, computationally demanding, numerical models. They may potentially be applied to non-modeled areas to provide screening or preliminary analysis tools for areas that do not yet have the benefit of more comprehensive study. In this decision-support mode, they may be fulfilling a role often accomplished by application of analytical solutions. The major challenge to transferring a metamodel to a non-modeled area is how to quantify the spatial data in the new area of interest in such a way that it is consistent with the data used to derive the metamodel. Tests based on transferring a metamodel derived from a numerical groundwater-flow model of the Lake Michigan Basin to other glacial settings across the northern U.S. show that the spatial scale of the numerical model must be appropriately scaled to adequately represent different settings. Careful GIS analysis of the numerical model, metamodel, and new area of interest is required for successful transfer of results.

  10. The Challenge of Forecasting Metropolitan Growth: Urban Characteristics Based Models versus Regional Dummy Based Models

    OpenAIRE

    NA

    2005-01-01

    This paper presents a study of errors in forecasting the population of Metropolitan Statistical Areas and the Primary MSAs of Consolidated Metropolitan Statistical Areas and New England MAs. The forecasts are for the year 2000 and are based on a semi-structural model estimated by Mills and Lubelle using 1970 to 1990 census data on population, employment and relative real wages. This model allows the testing of regional effects on population and employment growth. The year 2000 forecasts are f...

  11. Modelling noninvasively measured cerebral signals during a hypoxemia challenge: steps towards individualised modelling.

    Directory of Open Access Journals (Sweden)

    Beth Jelfs

    Full Text Available Noninvasive approaches to measuring cerebral circulation and metabolism are crucial to furthering our understanding of brain function. These approaches also have considerable potential for clinical use "at the bedside". However, a highly nontrivial task and precondition if such methods are to be used routinely is the robust physiological interpretation of the data. In this paper, we explore the ability of a previously developed model of brain circulation and metabolism to explain and predict quantitatively the responses of physiological signals. The five signals all noninvasively-measured during hypoxemia in healthy volunteers include four signals measured using near-infrared spectroscopy along with middle cerebral artery blood flow measured using transcranial Doppler flowmetry. We show that optimising the model using partial data from an individual can increase its predictive power thus aiding the interpretation of NIRS signals in individuals. At the same time such optimisation can also help refine model parametrisation and provide confidence intervals on model parameters. Discrepancies between model and data which persist despite model optimisation are used to flag up important questions concerning the underlying physiology, and the reliability and physiological meaning of the signals.

  12. Challenges and opportunities of modeling plasma–surface interactions in tungsten using high-performance computing

    Energy Technology Data Exchange (ETDEWEB)

    Wirth, Brian D., E-mail: bdwirth@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Nuclear Science and Engineering Directorate, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Hammond, K.D. [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Krasheninnikov, S.I. [University of California, San Diego, La Jolla, CA (United States); Maroudas, D. [University of Massachusetts, Amherst, Amherst, MA 01003 (United States)

    2015-08-15

    The performance of plasma facing components (PFCs) is critical for ITER and future magnetic fusion reactors. The ITER divertor will be tungsten, which is the primary candidate material for future reactors. Recent experiments involving tungsten exposure to low-energy helium plasmas reveal significant surface modification, including the growth of nanometer-scale tendrils of “fuzz” and formation of nanometer-sized bubbles in the near-surface region. The large span of spatial and temporal scales governing plasma surface interactions are among the challenges to modeling divertor performance. Fortunately, recent innovations in computational modeling, increasingly powerful high-performance computers, and improved experimental characterization tools provide a path toward self-consistent, experimentally validated models of PFC and divertor performance. Recent advances in understanding tungsten–helium interactions are reviewed, including such processes as helium clustering, which serve as nuclei for gas bubbles; and trap mutation, dislocation loop punching and bubble bursting; which together initiate surface morphological modification.

  13. Geant4 Hadronic Cascade Models and CMS Data Analysis : Computational Challenges in the LHC era

    CERN Document Server

    Heikkinen, Aatos

    This work belongs to the field of computational high-energy physics (HEP). The key methods used in this thesis work to meet the challenges raised by the Large Hadron Collider (LHC) era experiments are object-orientation with software engineering, Monte Carlo simulation, the computer technology of clusters, and artificial neural networks. The first aspect discussed is the development of hadronic cascade models, used for the accurate simulation of medium-energy hadron-nucleus reactions, up to 10 GeV. These models are typically needed in hadronic calorimeter studies and in the estimation of radiation backgrounds. Various applications outside HEP include the medical field (such as hadron treatment simulations), space science (satellite shielding), and nuclear physics (spallation studies). Validation results are presented for several significant improvements released in Geant4 simulation tool, and the significance of the new models for computing in the Large Hadron Collider era is estimated. In particular, we es...

  14. Recent progress and modern challenges in applied mathematics, modeling and computational science

    CERN Document Server

    Makarov, Roman; Belair, Jacques

    2017-01-01

    This volume is an excellent resource for professionals in various areas of applications of mathematics, modeling, and computational science. It focuses on recent progress and modern challenges in these areas. The volume provides a balance between fundamental theoretical and applied developments, emphasizing the interdisciplinary nature of modern trends and detailing state-of-the-art achievements in Applied Mathematics, Modeling, and Computational Science.  The chapters have been authored by international experts in their respective fields, making this book ideal for researchers in academia, practitioners, and graduate students. It can also serve as a reference in the diverse selected areas of applied mathematics, modelling, and computational sciences, and is ideal for interdisciplinary collaborations.

  15. Animal models of binge drinking, current challenges to improve face validity.

    Science.gov (United States)

    Jeanblanc, Jérôme; Rolland, Benjamin; Gierski, Fabien; Martinetti, Margaret P; Naassila, Mickael

    2018-05-05

    Binge drinking (BD), i.e., consuming a large amount of alcohol in a short period of time, is an increasing public health issue. Though no clear definition has been adopted worldwide the speed of drinking seems to be a keystone of this behavior. Developing relevant animal models of BD is a priority for gaining a better characterization of the neurobiological and psychobiological mechanisms underlying this dangerous and harmful behavior. Until recently, preclinical research on BD has been conducted mostly using forced administration of alcohol, but more recent studies used scheduled access to alcohol, to model more voluntary excessive intakes, and to achieve signs of intoxications that mimic the human behavior. The main challenges for future research are discussed regarding the need of good face validity, construct validity and predictive validity of animal models of BD. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Challenges and opportunities of modeling plasma–surface interactions in tungsten using high-performance computing

    International Nuclear Information System (INIS)

    Wirth, Brian D.; Hammond, K.D.; Krasheninnikov, S.I.; Maroudas, D.

    2015-01-01

    The performance of plasma facing components (PFCs) is critical for ITER and future magnetic fusion reactors. The ITER divertor will be tungsten, which is the primary candidate material for future reactors. Recent experiments involving tungsten exposure to low-energy helium plasmas reveal significant surface modification, including the growth of nanometer-scale tendrils of “fuzz” and formation of nanometer-sized bubbles in the near-surface region. The large span of spatial and temporal scales governing plasma surface interactions are among the challenges to modeling divertor performance. Fortunately, recent innovations in computational modeling, increasingly powerful high-performance computers, and improved experimental characterization tools provide a path toward self-consistent, experimentally validated models of PFC and divertor performance. Recent advances in understanding tungsten–helium interactions are reviewed, including such processes as helium clustering, which serve as nuclei for gas bubbles; and trap mutation, dislocation loop punching and bubble bursting; which together initiate surface morphological modification

  17. Some considerations concerning the challenge of incorporating social variables into epidemiological models of infectious disease transmission.

    Science.gov (United States)

    Barnett, Tony; Fournié, Guillaume; Gupta, Sunetra; Seeley, Janet

    2015-01-01

    Incorporation of 'social' variables into epidemiological models remains a challenge. Too much detail and models cease to be useful; too little and the very notion of infection - a highly social process in human populations - may be considered with little reference to the social. The French sociologist Émile Durkheim proposed that the scientific study of society required identification and study of 'social currents'. Such 'currents' are what we might today describe as 'emergent properties', specifiable variables appertaining to individuals and groups, which represent the perspectives of social actors as they experience the environment in which they live their lives. Here we review the ways in which one particular emergent property, hope, relevant to a range of epidemiological situations, might be used in epidemiological modelling of infectious diseases in human populations. We also indicate how such an approach might be extended to include a range of other potential emergent properties to represent complex social and economic processes bearing on infectious disease transmission.

  18. Chondronecrosis with osteomyelitis in broilers: Further defining a bacterial challenge model using the wire flooring model.

    Science.gov (United States)

    Al-Rubaye, Adnan A K; Ekesi, Nnamdi S; Zaki, Sura; Emami, Nima K; Wideman, Robert F; Rhoads, Douglas D

    2017-02-01

    Lameness in broiler chickens is a significant animal welfare and financial issue. Bacterial chondronecrosis with osteomyelitis (BCO) leading to lameness can be enhanced by rearing young broilers on wire flooring. Using the wire floor system, we identified Staphylococcus agnetis as the predominant isolate in BCO of the proximal tibiae and femora, and blood of lame broilers. Administration of S. agnetis isolates in water can induce lameness. We now report that the wire floor system increases bacterial translocation into the blood stream. We have also determined that approximately 10 5 CFU/mL is the minimum effective dose in the drinking water and that challenge at 10, 20, or 30 days of age produces similar incidences of lameness. BCO isolates of S. agnetis are much more effective than other Staphylococcus species and can overwhelm the protective effects of some commercial probiotics. Finally, we also demonstrated that the BCO lameness induced by administration of S. agnetis in the drinking water is transmissible to unchallenged broilers in the same pen. © 2016 Poultry Science Association Inc.

  19. The Nordic Model in a Global Company Situated in Norway. Challenging Institutional Orders?

    Directory of Open Access Journals (Sweden)

    Elin Kvande

    2012-11-01

    Full Text Available In this article, we explore the impact of internationalization as organizational processes where institutional actors meet in local contexts and negotiate the institutional order. The internationalization of working life implies that different traditions and practices meet and challenge each other. The focus is on how important elements of the Nordic micro model like cooperation between employees and employers and regulation of working hours are implemented in a global company situated in Norway. In general, it seems that employees and employers cooperate in line with this tradition in the Nordic micro model. Norwegian manager’s practices are described to be in accordance with Scandinavian management traditions, while managers from the United States appear to practice management consistent with the liberal working life model. The findings show a tension-filled clash between two different management practices, which indicates that the Nordic micro model in this field might be under pressure. Manager’s recommendation to the employees was not to become members of the trade union. The absence of trade unions in the organization implies that employees and employers are not cooperating on a collective level. This means that only parts of the regulatory arrangement related to participation and cooperation are implemented. Findings concerning working time and the relation to the institutional order represented by the Norwegian Work Environment Act indicate a clear tension between different institutional traditions in the organization. The company does not respect the Norwegian in working time regulations. These regulations are seen as counterproductive for a company that competes in the international market. This devaluation of the regulations in the Nordic model implies that the institutional order represented in the Nordic micro model is challenged.

  20. Advanced Modeling and Uncertainty Quantification for Flight Dynamics; Interim Results and Challenges

    Science.gov (United States)

    Hyde, David C.; Shweyk, Kamal M.; Brown, Frank; Shah, Gautam

    2014-01-01

    As part of the NASA Vehicle Systems Safety Technologies (VSST), Assuring Safe and Effective Aircraft Control Under Hazardous Conditions (Technical Challenge #3), an effort is underway within Boeing Research and Technology (BR&T) to address Advanced Modeling and Uncertainty Quantification for Flight Dynamics (VSST1-7). The scope of the effort is to develop and evaluate advanced multidisciplinary flight dynamics modeling techniques, including integrated uncertainties, to facilitate higher fidelity response characterization of current and future aircraft configurations approaching and during loss-of-control conditions. This approach is to incorporate multiple flight dynamics modeling methods for aerodynamics, structures, and propulsion, including experimental, computational, and analytical. Also to be included are techniques for data integration and uncertainty characterization and quantification. This research shall introduce new and updated multidisciplinary modeling and simulation technologies designed to improve the ability to characterize airplane response in off-nominal flight conditions. The research shall also introduce new techniques for uncertainty modeling that will provide a unified database model comprised of multiple sources, as well as an uncertainty bounds database for each data source such that a full vehicle uncertainty analysis is possible even when approaching or beyond Loss of Control boundaries. Methodologies developed as part of this research shall be instrumental in predicting and mitigating loss of control precursors and events directly linked to causal and contributing factors, such as stall, failures, damage, or icing. The tasks will include utilizing the BR&T Water Tunnel to collect static and dynamic data to be compared to the GTM extended WT database, characterizing flight dynamics in off-nominal conditions, developing tools for structural load estimation under dynamic conditions, devising methods for integrating various modeling elements

  1. Fundamental Challenges for Modeling Electrochemical Energy Storage Systems at the Atomic Scale.

    Science.gov (United States)

    Groß, Axel

    2018-04-23

    There is a strong need to improve the efficiency of electrochemical energy storage, but progress is hampered by significant technological and scientific challenges. This review describes the potential contribution of atomic-scale modeling to the development of more efficient batteries, with a particular focus on first-principles electronic structure calculations. Numerical and theoretical obstacles are discussed, along with ways to overcome them, and some recent examples are presented illustrating the insights into electrochemical energy storage that can be gained from quantum chemical studies.

  2. Advances and Challenges in Space-time Modelling of Natural Events

    CERN Document Server

    Porcu, Emilio; Schlather, Martin

    2012-01-01

    This book arises as the natural continuation of the International Spring School "Advances and Challenges in Space-Time modelling of Natural Events," which took place in Toledo (Spain) in March 2010. This Spring School above all focused on young researchers (Master students, PhD students and post-doctoral researchers) in academics, extra-university research and the industry who are interested in learning about recent developments, new methods and applications in spatial statistics and related areas, and in exchanging ideas and findings with colleagues.

  3. Challenges and Changes in University Organization: Towards a New Model of Teaching and Learning

    Directory of Open Access Journals (Sweden)

    Carlos Gómez Bahillo

    2015-01-01

    Full Text Available Globalization is producing a new world order that is affecting political, economic, social, cultural and educational institutions. Universities need to be the engine of this social change and to provide a dynamic, flexible and stable educational model which can generate a skilled workforce ready to face the new challenges of the information and knowledge society. The university must provide not only basic and specific knowledge that prepares students to embark upon a given profession but should develop students’ social and technical skills to facilitate their subsequent employment in a competitive and innovative production system that demands a skilled workforce.

  4. Challenges of implementing economic model predictive control strategy for buildings interacting with smart energy systems

    DEFF Research Database (Denmark)

    Zong, Yi; Böning, Georg Martin; Santos, Rui Mirra

    2016-01-01

    ) strategy for energy management in smart buildings, which can act as active users interacting with smart energy systems. The challenges encountered during the implementation of EMPC for active demand side management are investigated in detail in this paper. A pilot testing study shows energy savings......When there is a high penetration of renewables in the energy system, it requires proactive control of large numbers of distributed demand response resources to maintain the system’s reliability and improve its operational economics. This paper presents the Economic Model Predictive Control (EMPC...

  5. Circular Business Model Challenges and Lessons Learned—An Industrial Perspective

    Directory of Open Access Journals (Sweden)

    Pejvak Oghazi

    2018-03-01

    Full Text Available Both practitioners and researchers are concerned about resource deficiencies on the planet earth and agree that circular business models (CBMs represent solutions to move towards zero waste, improving environmental impacts and increasing economic profit. Despite all of the benefits of CBMs, the implications are not widely available, and failure rates are high. Thus, there is a need to identify the obstacles that stand in the way of CBM transition. This paper aims to identify the primary challenges of CBMs. Multiple case studies are employed, incorporating six companies and data gleaned from 17 in-depth interviews. Theoretical and managerial implications are described at the end of the study.

  6. [Peripheral intravenous catheter-related phlebitis].

    Science.gov (United States)

    van der Sar-van der Brugge, Simone; Posthuma, E F M Ward

    2011-01-01

    Phlebitis is a very common complication of the use of intravenous catheters. Two patients with an i.v. catheter complicated by thrombophlebitis are described. Patient A was immunocompromised due to chronic lymphatic leukaemia and developed septic thrombophlebitis with positive blood cultures for S. Aureus. Patient B was being treated with flucloxacillin because of an S. Aureus infection and developed chemical phlebitis. Septic phlebitis is rare, but potentially serious. Chemical or mechanical types of thrombophlebitis are usually less severe, but happen very frequently. Risk factors include: female sex, previous episode of phlebitis, insertion at (ventral) forearm, emergency placement and administration of antibiotics. Until recently, routine replacement of peripheral intravenous catheters after 72-96 h was recommended, but randomised controlled trials have not shown any benefit of this routine. A recent Cochrane Review recommends replacement of peripheral intravenous catheters when clinically indicated only.

  7. Challenges in modeling unstable two-phase flow experiments in porous micromodels

    Science.gov (United States)

    Meheust, Y.; Ferrari, A.; Jimenez-Martinez, J.; Le Borgne, T.; Lunati, I.

    2014-12-01

    The simulation of unstable invasion patterns in porous media flow is challenging since small perturbations tend to grow in time, so that slight differences in geometry or initial conditions potentially give rise to significantly different solutions. Here we present a detailed comparison of pore scale simulations and experiments of unstable primary drainage in porous micromodels. The porous medium consists of a Hele-Shaw cell containing cylindrical obstacles. Two experimental flow cells have been constructed by soft lithography, with different degrees of heterogeneity in the grain size distribution. To model two-phase flow at the pore scale, we solve Navier-Stokes equations for mass and momentum conservation in the discretized pore space and employ the Volume of Fluid (VOF) method to track the evolution of the interface. During drainage, if the defending fluid is the most viscous, viscous forces destabilize the interface, giving rise to the formation of preferential flow paths, in the form of a branched fingering structure. We test different numerical models (a 2D vertical integrated model and a full 3D model) and different initial conditions, studying their impact on the simulated spatial distributions of the fluid phases. Although due to the unstable nature of the invasion, small discrepancies between the experimental setup and the numerical model can result in different fluids patterns (see figure), simulations show a satisfactory agreement with the structures observed experimentally. To estimate the ability of the numerical approach to reproduce unstable displacement, we compare several quantities in both the statistical and deterministic sense. We demonstrate the impact of three main sources of uncertainty : i) the uncertainty on the pore space geometry, ii) the interface initialization and ii) three dimensional effects [1]. Simulations in weakly heterogeneous geometries are found to be more challenging because uncertainties on pore neck widths are on the same

  8. Adapting a regularized canopy reflectance model (REGFLEC) for the retrieval challenges of dryland agricultural systems

    KAUST Repository

    Houborg, Rasmus

    2016-08-20

    A regularized canopy reflectance model (REGFLEC) is applied over a dryland irrigated agricultural system in Saudi Arabia for the purpose of retrieving leaf area index (LAI) and leaf chlorophyll content (Chll). To improve the robustness of the retrieved properties, REGFLEC was modified to 1) correct for aerosol and adjacency effects, 2) consider foliar dust effects on modeled canopy reflectances, 3) include spectral information in the red-edge wavelength region, and 4) exploit empirical LAI estimates in the model inversion. Using multi-spectral RapidEye imagery allowed Chll to be retrieved with a Mean Absolute Deviation (MAD) of 7.9 μg cm− 2 (16%), based upon in-situ measurements conducted in fields of alfalfa, Rhodes grass and maize over the course of a growing season. LAI and Chll compensation effects on canopy reflectance were largely avoided by informing the inversion process with ancillary LAI inputs established empirically on the basis of a statistical machine learning technique. As a result, LAI was reproduced with good accuracy, with an overall MAD of 0.42 m2 m− 2 (12.5%). Results highlighted the considerable challenges associated with the translation of at-sensor radiance observations to surface bidirectional reflectances in dryland environments, where issues such as high aerosol loadings and large spatial gradients in surface reflectance from bright desert soils to dark vegetated fields are often present. Indeed, surface reflectances in the visible bands were reduced by up to 60% after correction for such adjacency effects. In addition, dust deposition on leaves required explicit modification of the reflectance sub-model to account for its influence. By implementing these model refinements, REGFLEC demonstrated its utility for within-field characterization of vegetation conditions over the challenging landscapes typical of dryland agricultural regions, offering a means through which improvements can be made in the management of these globally

  9. Crises and Collective Socio-Economic Phenomena: Simple Models and Challenges

    Science.gov (United States)

    Bouchaud, Jean-Philippe

    2013-05-01

    Financial and economic history is strewn with bubbles and crashes, booms and busts, crises and upheavals of all sorts. Understanding the origin of these events is arguably one of the most important problems in economic theory. In this paper, we review recent efforts to include heterogeneities and interactions in models of decision. We argue that the so-called Random Field Ising model ( rfim) provides a unifying framework to account for many collective socio-economic phenomena that lead to sudden ruptures and crises. We discuss different models that can capture potentially destabilizing self-referential feedback loops, induced either by herding, i.e. reference to peers, or trending, i.e. reference to the past, and that account for some of the phenomenology missing in the standard models. We discuss some empirically testable predictions of these models, for example robust signatures of rfim-like herding effects, or the logarithmic decay of spatial correlations of voting patterns. One of the most striking result, inspired by statistical physics methods, is that Adam Smith's invisible hand can fail badly at solving simple coordination problems. We also insist on the issue of time-scales, that can be extremely long in some cases, and prevent socially optimal equilibria from being reached. As a theoretical challenge, the study of so-called "detailed-balance" violating decision rules is needed to decide whether conclusions based on current models (that all assume detailed-balance) are indeed robust and generic.

  10. Sixth Grade Students' Content-Specific Competencies and Challenges in Learning the Seasons Through Modeling

    Science.gov (United States)

    Sung, Ji Young; Oh, Phil Seok

    2017-06-01

    Recent science education reform initiatives suggest that learning in science should be organized on the basis of scientists' actual practices including the development and use of models. In line with this, the current study adapted three types of modeling practices to teach two Korean 6th grade science classes the causes of the Earth's seasons. Specifically, the study aimed to identify the students' content-specific competencies and challenges based on fine-grained descriptions and analyses of two target groups' cases. Data included digital recordings of modeling-based science lessons in the two classes, the teacher's and students' artifacts, and interviews with the students. These multiple types of data were analyzed complementarily and qualitatively. It was revealed that the students had a competency in constructing models to generate the desired phenomenon (i.e., seasons). They had difficulty, however, in considering the tilt of the Earth's rotation axis as a cause of the seasons and in finding a proper way of representing the Sun's meridian altitude on a globe. But, when the students were helped and guided by the teacher and peers' interventions, they were able to revise their models in alignment with the scientific understanding of the seasons. Based on these findings, the teacher's pedagogical roles, which include using student competencies as resources, asking physical questions, and explicit guidance on experimentation skills, were recommended to support successful incorporations of modeling practices in the science classroom.

  11. Environmental fate and exposure models: advances and challenges in 21st century chemical risk assessment.

    Science.gov (United States)

    Di Guardo, Antonio; Gouin, Todd; MacLeod, Matthew; Scheringer, Martin

    2018-01-24

    Environmental fate and exposure models are a powerful means to integrate information on chemicals, their partitioning and degradation behaviour, the environmental scenario and the emissions in order to compile a picture of chemical distribution and fluxes in the multimedia environment. A 1995 pioneering book, resulting from a series of workshops among model developers and users, reported the main advantages and identified needs for research in the field of multimedia fate models. Considerable efforts were devoted to their improvement in the past 25 years and many aspects were refined; notably the inclusion of nanomaterials among the modelled substances, the development of models at different spatial and temporal scales, the estimation of chemical properties and emission data, the incorporation of additional environmental media and processes, the integration of sensitivity and uncertainty analysis in the simulations. However, some challenging issues remain and require research efforts and attention: the need of methods to estimate partition coefficients for polar and ionizable chemical in the environment, a better description of bioavailability in different environments as well as the requirement of injecting more ecological realism in exposure predictions to account for the diversity of ecosystem structures and functions in risk assessment. Finally, to transfer new scientific developments into the realm of regulatory risk assessment, we propose the formation of expert groups that compare, discuss and recommend model modifications and updates and help develop practical tools for risk assessment.

  12. Challenges for modeling global gene regulatory networks during development: insights from Drosophila.

    Science.gov (United States)

    Wilczynski, Bartek; Furlong, Eileen E M

    2010-04-15

    Development is regulated by dynamic patterns of gene expression, which are orchestrated through the action of complex gene regulatory networks (GRNs). Substantial progress has been made in modeling transcriptional regulation in recent years, including qualitative "coarse-grain" models operating at the gene level to very "fine-grain" quantitative models operating at the biophysical "transcription factor-DNA level". Recent advances in genome-wide studies have revealed an enormous increase in the size and complexity or GRNs. Even relatively simple developmental processes can involve hundreds of regulatory molecules, with extensive interconnectivity and cooperative regulation. This leads to an explosion in the number of regulatory functions, effectively impeding Boolean-based qualitative modeling approaches. At the same time, the lack of information on the biophysical properties for the majority of transcription factors within a global network restricts quantitative approaches. In this review, we explore the current challenges in moving from modeling medium scale well-characterized networks to more poorly characterized global networks. We suggest to integrate coarse- and find-grain approaches to model gene regulatory networks in cis. We focus on two very well-studied examples from Drosophila, which likely represent typical developmental regulatory modules across metazoans. Copyright (c) 2009 Elsevier Inc. All rights reserved.

  13. Use of intravenous immunoglobulins in clinical practice

    Directory of Open Access Journals (Sweden)

    E.K. Donyush

    2011-01-01

    Full Text Available Immunoglobulins are main component of immune defense; they take part in anti-infectious resistance of organism and regulate processes of different immune reactions. Intravenous immunoglobulins are the most frequently used products made from donor blood plasma. The need in these drugs is steadily increasing during last 15–20 years, and indications are widening due to modern hightechnology methods of production and cleaning. The article presents modern data on formula, mechanisms of action and indications for different groups of intravenous immunoglobulins (standard, hyperimmune, fortified and description of possible adverse events.Key words: immuglobulines, prophylaxis, treatment, unfavorable reaction, children.

  14. Practice models and challenges in teledermatology: a study of collective experiences from teledermatologists.

    Directory of Open Access Journals (Sweden)

    April W Armstrong

    Full Text Available BACKGROUND: Despite increasing practice of teledermatology in the U.S., teledermatology practice models and real-world challenges are rarely studied. METHODS: The primary objective was to examine teledermatology practice models and shared challenges among teledermatologists in California, focusing on practice operations, reimbursement considerations, barriers to sustainability, and incentives. We conducted in-depth interviews with teledermatologists that practiced store-and-forward or live-interactive teledermatology from January 1, 2007 through March 30, 2011 in California. RESULTS: Seventeen teledermatologists from academia, private practice, health maintenance organizations, and county settings participated in the study. Among them, 76% practiced store-and-forward only, 6% practiced live-interactive only, and 18% practiced both modalities. Only 29% received structured training in teledermatology. The average number of years practicing teledermatology was 4.29 years (SD±2.81. Approximately 47% of teledermatologists served at least one Federally Qualified Health Center. Over 75% of patients seen via teledermatology were at or below 200% federal poverty level and usually lived in rural regions without dermatologist access. Practice challenges were identified in the following areas. Teledermatologists faced delays in reimbursements and non-reimbursement of teledermatology services. The primary reason for operational inefficiency was poor image quality and/or inadequate history. Costly and inefficient software platforms and lack of communication with referring providers also presented barriers. CONCLUSION: Teledermatology enables underserved populations to access specialty care. Improvements in reimbursement mechanisms, efficient technology platforms, communication with referring providers, and teledermatology training are necessary to support sustainable practices.

  15. Findings and Challenges in Fine-Resolution Large-Scale Hydrological Modeling

    Science.gov (United States)

    Her, Y. G.

    2017-12-01

    Fine-resolution large-scale (FL) modeling can provide the overall picture of the hydrological cycle and transport while taking into account unique local conditions in the simulation. It can also help develop water resources management plans consistent across spatial scales by describing the spatial consequences of decisions and hydrological events extensively. FL modeling is expected to be common in the near future as global-scale remotely sensed data are emerging, and computing resources have been advanced rapidly. There are several spatially distributed models available for hydrological analyses. Some of them rely on numerical methods such as finite difference/element methods (FDM/FEM), which require excessive computing resources (implicit scheme) to manipulate large matrices or small simulation time intervals (explicit scheme) to maintain the stability of the solution, to describe two-dimensional overland processes. Others make unrealistic assumptions such as constant overland flow velocity to reduce the computational loads of the simulation. Thus, simulation efficiency often comes at the expense of precision and reliability in FL modeling. Here, we introduce a new FL continuous hydrological model and its application to four watersheds in different landscapes and sizes from 3.5 km2 to 2,800 km2 at the spatial resolution of 30 m on an hourly basis. The model provided acceptable accuracy statistics in reproducing hydrological observations made in the watersheds. The modeling outputs including the maps of simulated travel time, runoff depth, soil water content, and groundwater recharge, were animated, visualizing the dynamics of hydrological processes occurring in the watersheds during and between storm events. Findings and challenges were discussed in the context of modeling efficiency, accuracy, and reproducibility, which we found can be improved by employing advanced computing techniques and hydrological understandings, by using remotely sensed hydrological

  16. The multiple time scales of sleep dynamics as a challenge for modelling the sleeping brain.

    Science.gov (United States)

    Olbrich, Eckehard; Claussen, Jens Christian; Achermann, Peter

    2011-10-13

    A particular property of the sleeping brain is that it exhibits dynamics on very different time scales ranging from the typical sleep oscillations such as sleep spindles and slow waves that can be observed in electroencephalogram (EEG) segments of several seconds duration over the transitions between the different sleep stages on a time scale of minutes to the dynamical processes involved in sleep regulation with typical time constants in the range of hours. There is an increasing body of work on mathematical and computational models addressing these different dynamics, however, usually considering only processes on a single time scale. In this paper, we review and present a new analysis of the dynamics of human sleep EEG at the different time scales and relate the findings to recent modelling efforts pointing out both the achievements and remaining challenges.

  17. Data Mining and Pattern Recognition Models for Identifying Inherited Diseases: Challenges and Implications.

    Science.gov (United States)

    Iddamalgoda, Lahiru; Das, Partha S; Aponso, Achala; Sundararajan, Vijayaraghava S; Suravajhala, Prashanth; Valadi, Jayaraman K

    2016-01-01

    Data mining and pattern recognition methods reveal interesting findings in genetic studies, especially on how the genetic makeup is associated with inherited diseases. Although researchers have proposed various data mining models for biomedical approaches, there remains a challenge in accurately prioritizing the single nucleotide polymorphisms (SNP) associated with the disease. In this commentary, we review the state-of-art data mining and pattern recognition models for identifying inherited diseases and deliberate the need of binary classification- and scoring-based prioritization methods in determining causal variants. While we discuss the pros and cons associated with these methods known, we argue that the gene prioritization methods and the protein interaction (PPI) methods in conjunction with the K nearest neighbors' could be used in accurately categorizing the genetic factors in disease causation.

  18. Data mining and Pattern Recognizing Models for Identifying Inherited Diseases: Challenges and Implications

    Directory of Open Access Journals (Sweden)

    Lahiru Iddamalgoda

    2016-08-01

    Full Text Available Data mining and pattern recognition methods reveal interesting findings in genetic studies, especially on how genetic makeup is associated with inherited diseases. Although researchers have proposed various data mining models for biomedical approaches, there remains a challenge in accurately determining the responsible genetic factors for prioritizing the single nucleotide polymorphisms (SNP associated with the disease. In this commentary, we review the state-of-art data mining and pattern recognition models for identifying inherited diseases and deliberate the need of binary classification and scoring based prioritization methods for determining causal variants. While we discuss the pros and cons associated with these methods known, we argue that the gene prioritization methods and the protein interaction (PPI methods in conjunction with the K nearest neighbors’ could be used in accurately categorizing the genetic factors in disease causation

  19. From the Rodent Spinal Cord Injury Model to Human Application: Promises and Challenges.

    Science.gov (United States)

    Dietz, Volker; Schwab, Martin E

    2017-05-01

    Repair of the spinal cord and improvement of mobility after injury has been a matter of basic and clinical research for several decades. A number of repair approaches were performed in animals, mainly rodent models of spinal cord injury (SCI). Some of these experimental therapies resulted in significant regeneration of tract fibers, formation of new connections and circuits, and associated improvement of mobility. Some clinical trials aiming at translating these approaches to the human condition of an SCI are currently on-going. The present therapy, however, remains rehabiliation: Mobility of patients with an SCI can be improved to a limited extent by the exploition of neuroplasticity. In this article the present state of the art in the field of SCI research will be discussed. Studies dealing with the promotion of spinal cord repair and those directed to improve mobility by exploition of neuroplasticity will be summarized. The promises and challenges of translational basic research in rodent SCI models will be presented.

  20. State and transition models: Theory, applications, and challenges. In: Briske, D.D. Rangeland Systems: Processes, Management and Challenges

    Science.gov (United States)

    State and transition models (STMs) are used for communicating about ecosystem change in rangelands and other ecosystems, especially the implications for management. The fundamental premise that rangelands can exhibit multiple states is now widely accepted. The current application of STMs for managem...

  1. Outreach training model for accredited colorectal specialists in laparoscopic colorectal surgery: feasibility and evaluation of challenges.

    Science.gov (United States)

    Hamdan, M F; Day, A; Millar, J; Carter, F J C; Coleman, M G; Francis, N K

    2015-07-01

    The aim of this study was to explore the feasibility and safety of an outreach model of laparoscopic colorectal training of accredited specialists in advanced laparoscopic techniques and to explore the challenges of this model from the perspective of a National Training Programme (NTP) trainer. Prospective data were collected for unselected laparoscopic colorectal training procedures performed by five laparoscopic colorectal NTP trainees supervised by a single NTP trainer with an outreach model between 2009 and 2012. The operative and postoperative outcomes were compared with standard laparoscopic colorectal training procedures performed by six senior colorectal trainees under the supervision of the same NTP trainer within the same study period. The primary outcome was 30-day mortality. The Mann-Whitney test was used to compare continuous variables and the Chi squared or Fisher's exact tests were applied for the analysis of categorical variables. The level of statistical significance was set at P groups. Seventy-eight per cent of the patients operated on by the NTP trainees had had no previous abdominal surgery, compared with 50% in the supervised trainees' group (P = 0.0005). There were no significant differences in 30-day mortality or the operative and postoperative outcome between both groups. There were, however, difficulties in training an already established consultant in his or her own hospital and these were overcome by certain adjustments to the programme. Outreach laparoscopic training of colorectal surgeons is a feasible and safe model of training accredited specialists and does not compromise patient care. The challenges encountered can be overcome with optimum training and preparation. Colorectal Disease © 2015 The Association of Coloproctology of Great Britain and Ireland.

  2. Business model generation a handbook for visionaries, game changers, and challengers

    CERN Document Server

    Osterwalder, Alexander

    2010-01-01

    Business Model Generation is a handbook for visionaries, game changers, and challengers striving to defy outmoded business models and design tomorrow′s enterprises. If your organization needs to adapt to harsh new realities, but you don′t yet have a strategy that will get you out in front of your competitors, you need Business Model Generation. Co–created by 470 "Business Model Canvas" practitioners from 45 countries, the book features a beautiful, highly visual, 4–color design that takes powerful strategic ideas and tools, and makes them easy to implement in your organization. It explains the most common Business Model patterns, based on concepts from leading business thinkers, and helps you reinterpret them for your own context. You will learn how to systematically understand, design, and implement a game–changing business model––or analyze and renovate an old one. Along the way, you′ll understand at a much deeper level your customers, distribution channels, partners, revenue streams, costs...

  3. Respiratory nanoparticle-based vaccines and challenges associated with animal models and translation.

    Science.gov (United States)

    Renukaradhya, Gourapura J; Narasimhan, Balaji; Mallapragada, Surya K

    2015-12-10

    Vaccine development has had a huge impact on human health. However, there is a significant need to develop efficacious vaccines for several existing as well as emerging respiratory infectious diseases. Several challenges need to be overcome to develop efficacious vaccines with translational potential. This review focuses on two aspects to overcome some barriers - 1) the development of nanoparticle-based vaccines, and 2) the choice of suitable animal models for respiratory infectious diseases that will allow for translation. Nanoparticle-based vaccines, including subunit vaccines involving synthetic and/or natural polymeric adjuvants and carriers, as well as those based on virus-like particles offer several key advantages to help overcome the barriers to effective vaccine development. These include the ability to deliver combinations of antigens, target the vaccine formulation to specific immune cells, enable cross-protection against divergent strains, act as adjuvants or immunomodulators, allow for sustained release of antigen, enable single dose delivery, and potentially obviate the cold chain. While mouse models have provided several important insights into the mechanisms of infectious diseases, they are often a limiting step in translation of new vaccines to the clinic. An overview of different animal models involved in vaccine research for respiratory infections, with advantages and disadvantages of each model, is discussed. Taken together, advances in nanotechnology, combined with the right animal models for evaluating vaccine efficacy, has the potential to revolutionize vaccine development for respiratory infections. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Modeling of biomass-to-energy supply chain operations: Applications, challenges and research directions

    International Nuclear Information System (INIS)

    Mafakheri, Fereshteh; Nasiri, Fuzhan

    2014-01-01

    Reducing dependency on fossil fuels and mitigating their environmental impacts are among the most promising aspects of utilizing renewable energy sources. The availability of various biomass resources has made it an appealing source of renewable energy. Given the variability of supply and sources of biomass, supply chains play an important role in the efficient provisioning of biomass resources for energy production. This paper provides a comprehensive review and classification of the excising literature in modeling of biomass supply chain operations while linking them to the wider strategic challenges and issues with the design, planning and management of biomass supply chains. On that basis, we will present an analysis of the existing gaps and the potential future directions for research in modeling of biomass supply chain operations. - Highlights: • An extensive review of biomass supply chain operations management models presented in the literature is provided. • The models are classified in line with biomass supply chain activities from harvesting to conversion. • The issues surrounding biomass supply chains are investigated manifesting the need to novel modeling approaches. • Our gap analysis has identified a number of existing shortcomings and opportunities for future research

  5. Clinical challenges of chronic wounds: searching for an optimal animal model to recapitulate their complexity

    Directory of Open Access Journals (Sweden)

    Robert Nunan

    2014-11-01

    Full Text Available The efficient healing of a skin wound is something that most of us take for granted but is essential for surviving day-to-day knocks and cuts, and is absolutely relied on clinically whenever a patient receives surgical intervention. However, the management of a chronic wound – defined as a barrier defect that has not healed in 3 months – has become a major therapeutic challenge throughout the Western world, and it is a problem that will only escalate with the increasing incidence of conditions that impede wound healing, such as diabetes, obesity and vascular disorders. Despite being clinically and molecularly heterogeneous, all chronic wounds are generally assigned to one of three major clinical categories: leg ulcers, diabetic foot ulcers or pressure ulcers. Although we have gleaned much knowledge about the fundamental cellular and molecular mechanisms that underpin healthy, acute wound healing from various animal models, we have learned much less about chronic wound repair pathology from these models. This might largely be because the animal models being used in this field of research have failed to recapitulate the clinical features of chronic wounds. In this Clinical Puzzle article, we discuss the clinical complexity of chronic wounds and describe the best currently available models for investigating chronic wound pathology. We also assess how such models could be optimised to become more useful tools for uncovering pathological mechanisms and potential therapeutic treatments.

  6. Challenges to modeling the Sun-Earth System: A Workshop Summary

    Science.gov (United States)

    Spann, James F.

    2006-01-01

    This special issue of the Journal of' Atmospheric and Solar-Terrestrial Physics is a compilation of 23 papers presented at The 2004 Huntsville Modeling Workshop: Challenges to Modeling thc San-Earth System held in Huntsville, AB on October 18-22, 2004. The title of the workshop appropriately captures the theme of what was presented and discussed by the 120 participants. Currently, end-to-end modeling of the Sun-Earth system is a major goal of the National Space Weather and NASA living with a star (LWS) programs. While profound advances have been made in modeling isolated regions of the Sun-Earth system, minimal progress has been achieved in modeling the end-to-end system. The transfer of mass, energy and momentum through the coupled Sun-Earth system spans a wide range of scales inn time and space. The uncertainty in the underlying physics responsible for coupling contiguous regions of the Sun-Earth system is recognized as a significant barrier to progress

  7. Cloud ice: A climate model challenge with signs and expectations of progress

    Science.gov (United States)

    Waliser, Duane E.; Li, Jui-Lin F.; Woods, Christopher P.; Austin, Richard T.; Bacmeister, Julio; Chern, Jiundar; Del Genio, Anthony; Jiang, Jonathan H.; Kuang, Zhiming; Meng, Huan; Minnis, Patrick; Platnick, Steve; Rossow, William B.; Stephens, Graeme L.; Sun-Mack, Szedung; Tao, Wei-Kuo; Tompkins, Adrian M.; Vane, Deborah G.; Walker, Christopher; Wu, Dong

    2009-04-01

    Present-day shortcomings in the representation of upper tropospheric ice clouds in general circulation models (GCMs) lead to errors in weather and climate forecasts as well as account for a source of uncertainty in climate change projections. An ongoing challenge in rectifying these shortcomings has been the availability of adequate, high-quality, global observations targeting ice clouds and related precipitating hydrometeors. In addition, the inadequacy of the modeled physics and the often disjointed nature between model representation and the characteristics of the retrieved/observed values have hampered GCM development and validation efforts from making effective use of the measurements that have been available. Thus, even though parameterizations in GCMs accounting for cloud ice processes have, in some cases, become more sophisticated in recent years, this development has largely occurred independently of the global-scale measurements. With the relatively recent addition of satellite-derived products from Aura/Microwave Limb Sounder (MLS) and CloudSat, there are now considerably more resources with new and unique capabilities to evaluate GCMs. In this article, we illustrate the shortcomings evident in model representations of cloud ice through a comparison of the simulations assessed in the Intergovernmental Panel on Climate Change Fourth Assessment Report, briefly discuss the range of global observational resources that are available, and describe the essential components of the model parameterizations that characterize their "cloud" ice and related fields. Using this information as background, we (1) discuss some of the main considerations and cautions that must be taken into account in making model-data comparisons related to cloud ice, (2) illustrate present progress and uncertainties in applying satellite cloud ice (namely from MLS and CloudSat) to model diagnosis, (3) show some indications of model improvements, and finally (4) discuss a number of

  8. Prediction of lake surface temperature using the air2water model: guidelines, challenges, and future perspectives

    Directory of Open Access Journals (Sweden)

    Sebastiano Piccolroaz

    2016-04-01

    leading to the risk of overfitting. The final aim of the work is to facilitate the use of the model also by scientists that do not necessarily have a solid background on modelling or physics. However, this work should not be considered simply as a collection of best practices, but also as the attempt to foster the communication and interaction among colleagues of a branch of science, limnology, that suffer of significant fragmentation. This is summarized in the future perspectives and challenges concerning potential improvements of the air2water, with a particular emphasis on possible cross-sectoral applications.

  9. Modeling and simulation challenges pursued by the Consortium for Advanced Simulation of Light Water Reactors (CASL)

    Energy Technology Data Exchange (ETDEWEB)

    Turinsky, Paul J., E-mail: turinsky@ncsu.edu [North Carolina State University, PO Box 7926, Raleigh, NC 27695-7926 (United States); Kothe, Douglas B., E-mail: kothe@ornl.gov [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6164 (United States)

    2016-05-15

    The Consortium for the Advanced Simulation of Light Water Reactors (CASL), the first Energy Innovation Hub of the Department of Energy, was established in 2010 with the goal of providing modeling and simulation (M&S) capabilities that support and accelerate the improvement of nuclear energy's economic competitiveness and the reduction of spent nuclear fuel volume per unit energy, and all while assuring nuclear safety. To accomplish this requires advances in M&S capabilities in radiation transport, thermal-hydraulics, fuel performance and corrosion chemistry. To focus CASL's R&D, industry challenge problems have been defined, which equate with long standing issues of the nuclear power industry that M&S can assist in addressing. To date CASL has developed a multi-physics “core simulator” based upon pin-resolved radiation transport and subchannel (within fuel assembly) thermal-hydraulics, capitalizing on the capabilities of high performance computing. CASL's fuel performance M&S capability can also be optionally integrated into the core simulator, yielding a coupled multi-physics capability with untapped predictive potential. Material models have been developed to enhance predictive capabilities of fuel clad creep and growth, along with deeper understanding of zirconium alloy clad oxidation and hydrogen pickup. Understanding of corrosion chemistry (e.g., CRUD formation) has evolved at all scales: micro, meso and macro. CFD R&D has focused on improvement in closure models for subcooled boiling and bubbly flow, and the formulation of robust numerical solution algorithms. For multiphysics integration, several iterative acceleration methods have been assessed, illuminating areas where further research is needed. Finally, uncertainty quantification and data assimilation techniques, based upon sampling approaches, have been made more feasible for practicing nuclear engineers via R&D on dimensional reduction and biased sampling. Industry adoption of CASL

  10. The Grand Challenge of Basin-Scale Groundwater Quality Management Modelling

    Science.gov (United States)

    Fogg, G. E.

    2017-12-01

    The last 50+ years of agricultural, urban and industrial land and water use practices have accelerated the degradation of groundwater quality in the upper portions of many major aquifer systems upon which much of the world relies for water supply. In the deepest and most extensive systems (e.g., sedimentary basins) that typically have the largest groundwater production rates and hold fresh groundwaters on decadal to millennial time scales, most of the groundwater is not yet contaminated. Predicting the long-term future groundwater quality in such basins is a grand scientific challenge. Moreover, determining what changes in land and water use practices would avert future, irreversible degradation of these massive freshwater stores is a grand challenge both scientifically and societally. It is naïve to think that the problem can be solved by eliminating or reducing enough of the contaminant sources, for human exploitation of land and water resources will likely always result in some contamination. The key lies in both reducing the contaminant sources and more proactively managing recharge in terms of both quantity and quality, such that the net influx of contaminants is sufficiently moderate and appropriately distributed in space and time to reverse ongoing groundwater quality degradation. Just as sustainable groundwater quantity management is greatly facilitated with groundwater flow management models, sustainable groundwater quality management will require the use of groundwater quality management models. This is a new genre of hydrologic models do not yet exist, partly because of the lack of modeling tools and the supporting research to model non-reactive as well as reactive transport on large space and time scales. It is essential that the contaminant hydrogeology community, which has heretofore focused almost entirely on point-source plume-scale problems, direct it's efforts toward the development of process-based transport modeling tools and analyses capable

  11. Clinical Evaluation of Ciprofloxacin Intravenous Preparation ...

    African Journals Online (AJOL)

    The most common site of bacteria infection in humans is the urinary tract. For nosocomial infections it is the catheterized urinary tract. Compromised immune responses in hospitalized patients contribute to the difficulties encountered in treating their infections. In these patients, administration of intravenous antibiotic is ...

  12. The adverse effects of inadvertent intraoperative intravenous ...

    African Journals Online (AJOL)

    Inadvertent intravenous injection of 1% phenylephrine (10 mg) induced severe hypertension and tachycardia in a previously healthy female patient undergoing elective gynaecological surgery. This medical error was investigated using the criticalincident technique that is available in our department. This case report ...

  13. [Phlebitis associated to intravenous/infusional therapy].

    Science.gov (United States)

    Nicotera, Raffaela

    2011-01-01

    Phlebitis is a common problem associated to intravenous therapies, it may cause pain, sepsis and increased duration of hospitalization. Several factors can increase the risk of phlebitis. The literature review addresses the mechanisms of chemical phlebitis, the characteristics of drugs likely to cause a phlebitis and the main measures to be adopted for prevention and treatment.

  14. Intravenous iron supplementation in children on hemodialysis.

    NARCIS (Netherlands)

    Leijn, E.; Monnens, L.A.H.; Cornelissen, E.A.M.

    2004-01-01

    BACKGROUND: Children with end-stage renal disease (ESRD) on hemodialysis (HD) are often absolute or functional iron deficient. There is little experience in treating these children with intravenous (i.v.) iron-sucrose. In this prospective study, different i.v. iron-sucrose doses were tested in

  15. Campaign best practice in intravenous therapy.

    Science.gov (United States)

    Baldwin, Wayne; Murphy, Jayne; Shakespeare, David; Kelly, Chris; Fox, Louise; Kelly, Matthew

    Intravenous therapy is an integral part of nursing care but is associated with a high risk of infection. This article outlines a campaign that aimed to increase awareness of best practice for IV therapy and reduce the risks of healthcare-associated IV infections in hospital and community settings.

  16. Intravenous voriconazole after toxic oral administration

    NARCIS (Netherlands)

    Alffenaar, J.W.C.; Van Assen, S.; De Monchy, J.G.R.; Uges, D.R.A.; Kosterink, J.G.W.; Van Der Werf, T.S.

    In a male patient with rhinocerebral invasive aspergillosis, prolonged high-dosage oral administration of voriconazole led to hepatotoxicity combined with a severe cutaneous reaction while intravenous administration in the same patient did not. High concentrations in the portal blood precipitate

  17. Complex intravenous anesthesia in interventional procedures

    International Nuclear Information System (INIS)

    Xie Zonggui; Hu Yuanming; Huang Yunlong; You Yong; Wu Juan; Huang Zengping; Li Jian

    2006-01-01

    Objective: To evaluate the value and safety of Diprivan and Fentany intravenous administration of analgesia in interventional procedures. Methods: Diprivan with Fentany intravenous administration for analgesia was used in eighty interventional procedures of sixty-five patients, without tracheal tube insertion. Vital signs including HR, BP, arterial oxygen saturation (SpO 2 ) and patients' reaction to operating were recorded. Results: Intravenous anesthesia was cared out successfully in eighty interventional procedures, with patients under sleeping condition during the operation, together with no pain and no agony memory of the procedure. The amount of Diprivan was 500±100 mg and Fentany was 0.2±0.025 mg. Mean arterial pressure and SpO 2 were 11.4±2.2 kPa, 10.6±2.1 kPa and 98±1.0, 96±1.5 respectively before and after ten minutes of the operation, with no significant difference. Conclusions: Diprivan with Fentany intravenous administration for interventional procedure analgesia possess good safety, painless and no agony memory of the procedure; therefor ought to be recommended. (authors)

  18. Intravenous paracetamol overdose in a paediatric patient

    NARCIS (Netherlands)

    Broeks, Ilse J.; Van Roon, Eric N.; Van Pinxteren-Nagler, Evelyn; De Vries, Tjalling W.

    2013-01-01

    BACKGROUND: Paracetamol is a widely used drug in children. In therapeutic doses, paracetamol has an excellent safety profile. Since the introduction of the intravenous form in 2004, only three reports of accidental overdose in children have been published. The low number probably is due to

  19. Administration and monitoring of intravenous anesthetics

    NARCIS (Netherlands)

    Sahinovic, Marko M.; Absalom, Anthony R.; Struys, Michel M. R. F.

    2010-01-01

    Purpose of review The importance of accuracy in controlling the dose-response relation for intravenous anesthetics is directly related to the importance of optimizing the efficacy and quality of anesthesia while minimizing adverse drug effects. Therefore, it is important to measure and control all

  20. Statistical challenges in modelling the health consequences of social mobility: the need for diagonal reference models.

    Science.gov (United States)

    van der Waal, Jeroen; Daenekindt, Stijn; de Koster, Willem

    2017-12-01

    Various studies on the health consequences of socio-economic position address social mobility. They aim to uncover whether health outcomes are affected by: (1) social mobility, besides, (2) social origin, and (3) social destination. Conventional methods do not, however, estimate these three effects separately, which may produce invalid conclusions. We highlight that diagonal reference models (DRMs) overcome this problem, which we illustrate by focusing on overweight/obesity (OWOB). Using conventional methods (logistic-regression analyses with dummy variables) and DRMs, we examine the effects of intergenerational educational mobility on OWOB (BMI ≥ 25 kg/m 2 ) using survey data representative of the Dutch population aged 18-45 (1569 males, 1771 females). Conventional methods suggest that mobility effects on OWOB are present. Analyses with DRMs, however, indicate that no such effects exist. Conventional analyses of the health consequences of social mobility may produce invalid results. We, therefore, recommend the use of DRMs. DRMs also validly estimate the health consequences of other types of social mobility (e.g. intra- and intergenerational occupational and income mobility) and status inconsistency (e.g. in educational or occupational attainment between partners).

  1. Mathematical models for lymphatic filariasis transmission and control: Challenges and prospects

    Directory of Open Access Journals (Sweden)

    Kaliannagounder Krishnamoorthy

    2008-02-01

    Full Text Available Abstract Background Mathematical models developed for describing the dynamics of transmission, infection, disease and control of lymphatic filariasis (LF gained momentum following the 1997 World Health Assembly resolution and the launching of the Global Programme to Eliminate Lymphatic Filariasis (GPELF in 2000. Model applications could provide valuable inputs for making decisions while implementing large scale programmes. However these models need to be evaluated at different epidemiological settings for optimization and fine-tuning with new knowledge and understanding on infection/disease dynamics. Discussion EPIFIL and LYMFASIM are the two mathematical simulation models currently available for lymphatic filariasis transmission and control. Both models have been used for prediction and evaluation of control programmes under research settings. Their widespread application in evaluating large-scale elimination programmes warrants validation of assumptions governing the dynamics of infection and disease in different epidemiological settings. Furthermore, the predictive power of the models for decision support can be enhanced by generating knowledge on some important issues that pose challenges and incorporating such knowledge into the models. We highlight factors related to the efficacy of the drugs of choice, their mode of action, and the possibility that drug resistance may develop; the role of vector-parasite combinations; the magnitude of transmission thresholds; host-parasite interactions and their effects on the dynamics of infection and immunity; parasite biology, and progression to LF-associated disease. Summary The two mathematical models developed offer potential decision making tools for transmission and control of LF. In view of the goals of the GPELF, the predictive power of these models needs to be enhanced for their wide-spread application in large scale programmes. Assimilation and translation of new information into the models is

  2. GIS-Based Planning and Modeling for Renewable Energy: Challenges and Future Research Avenues

    Directory of Open Access Journals (Sweden)

    Bernd Resch

    2014-05-01

    Full Text Available In the face of the broad political call for an “energy turnaround”, we are currently witnessing three essential trends with regard to energy infrastructure planning, energy generation and storage: from planned production towards fluctuating production on the basis of renewable energy sources, from centralized generation towards decentralized generation and from expensive energy carriers towards cost-free energy carriers. These changes necessitate considerable modifications of the energy infrastructure. Even though most of these modifications are inherently motivated by geospatial questions and challenges, the integration of energy system models and Geographic Information Systems (GIS is still in its infancy. This paper analyzes the shortcomings of previous approaches in using GIS in renewable energy-related projects, extracts distinct challenges from these previous efforts and, finally, defines a set of core future research avenues for GIS-based energy infrastructure planning with a focus on the use of renewable energy. These future research avenues comprise the availability base data and their “geospatial awareness”, the development of a generic and unified data model, the usage of volunteered geographic information (VGI and crowdsourced data in analysis processes, the integration of 3D building models and 3D data analysis, the incorporation of network topologies into GIS, the harmonization of the heterogeneous views on aggregation issues in the fields of energy and GIS, fine-grained energy demand estimation from freely-available data sources, decentralized storage facility planning, the investigation of GIS-based public participation mechanisms, the transition from purely structural to operational planning, data privacy aspects and, finally, the development of a new dynamic power market design.

  3. Hyperresolution global land surface modeling: Meeting a grand challenge for monitoring Earth's terrestrial water

    Science.gov (United States)

    Wood, Eric F.; Roundy, Joshua K.; Troy, Tara J.; van Beek, L. P. H.; Bierkens, Marc F. P.; Blyth, Eleanor; de Roo, Ad; DöLl, Petra; Ek, Mike; Famiglietti, James; Gochis, David; van de Giesen, Nick; Houser, Paul; Jaffé, Peter R.; Kollet, Stefan; Lehner, Bernhard; Lettenmaier, Dennis P.; Peters-Lidard, Christa; Sivapalan, Murugesu; Sheffield, Justin; Wade, Andrew; Whitehead, Paul

    2011-05-01

    Monitoring Earth's terrestrial water conditions is critically important to many hydrological applications such as global food production; assessing water resources sustainability; and flood, drought, and climate change prediction. These needs have motivated the development of pilot monitoring and prediction systems for terrestrial hydrologic and vegetative states, but to date only at the rather coarse spatial resolutions (˜10-100 km) over continental to global domains. Adequately addressing critical water cycle science questions and applications requires systems that are implemented globally at much higher resolutions, on the order of 1 km, resolutions referred to as hyperresolution in the context of global land surface models. This opinion paper sets forth the needs and benefits for a system that would monitor and predict the Earth's terrestrial water, energy, and biogeochemical cycles. We discuss six major challenges in developing a system: improved representation of surface-subsurface interactions due to fine-scale topography and vegetation; improved representation of land-atmospheric interactions and resulting spatial information on soil moisture and evapotranspiration; inclusion of water quality as part of the biogeochemical cycle; representation of human impacts from water management; utilizing massively parallel computer systems and recent computational advances in solving hyperresolution models that will have up to 109 unknowns; and developing the required in situ and remote sensing global data sets. We deem the development of a global hyperresolution model for monitoring the terrestrial water, energy, and biogeochemical cycles a "grand challenge" to the community, and we call upon the international hydrologic community and the hydrological science support infrastructure to endorse the effort.

  4. Molecular genetic models related to schizophrenia and psychotic illness: heuristics and challenges.

    Science.gov (United States)

    O'Tuathaigh, Colm M P; Desbonnet, Lieve; Moran, Paula M; Kirby, Brian P; Waddington, John L

    2011-01-01

    Schizophrenia is a heritable disorder that may involve several common genes of small effect and/or rare copy number variation, with phenotypic heterogeneity across patients. Furthermore, any boundaries vis-à-vis other psychotic disorders are far from clear. Consequently, identification of informative animal models for this disorder, which typically relate to pharmacological and putative pathophysiological processes of uncertain validity, faces considerable challenges. In juxtaposition, the majority of mutant models for schizophrenia relate to the functional roles of a diverse set of genes associated with risk for the disorder or with such putative pathophysiological processes. This chapter seeks to outline the evidence from phenotypic studies in mutant models related to schizophrenia. These have commonly assessed the degree to which mutation of a schizophrenia-related gene is associated with the expression of several aspects of the schizophrenia phenotype or more circumscribed, schizophrenia-related endophenotypes; typically, they place specific emphasis on positive and negative symptoms and cognitive deficits, and extend to structural and other pathological features. We first consider the primary technological approaches to the generation of such mutants, to include their relative merits and demerits, and then highlight the diverse phenotypic approaches that have been developed for their assessment. The chapter then considers the application of mutant phenotypes to study pathobiological and pharmacological mechanisms thought to be relevant for schizophrenia, particularly in terms of dopaminergic and glutamatergic dysfunction, and to an increasing range of candidate susceptibility genes and copy number variants. Finally, we discuss several pertinent issues and challenges within the field which relate to both phenotypic evaluation and a growing appreciation of the functional genomics of schizophrenia and the involvement of gene × environment interactions.

  5. Modeling and simulation challenges pursued by the Consortium for Advanced Simulation of Light Water Reactors (CASL)

    Science.gov (United States)

    Turinsky, Paul J.; Kothe, Douglas B.

    2016-05-01

    The Consortium for the Advanced Simulation of Light Water Reactors (CASL), the first Energy Innovation Hub of the Department of Energy, was established in 2010 with the goal of providing modeling and simulation (M&S) capabilities that support and accelerate the improvement of nuclear energy's economic competitiveness and the reduction of spent nuclear fuel volume per unit energy, and all while assuring nuclear safety. To accomplish this requires advances in M&S capabilities in radiation transport, thermal-hydraulics, fuel performance and corrosion chemistry. To focus CASL's R&D, industry challenge problems have been defined, which equate with long standing issues of the nuclear power industry that M&S can assist in addressing. To date CASL has developed a multi-physics ;core simulator; based upon pin-resolved radiation transport and subchannel (within fuel assembly) thermal-hydraulics, capitalizing on the capabilities of high performance computing. CASL's fuel performance M&S capability can also be optionally integrated into the core simulator, yielding a coupled multi-physics capability with untapped predictive potential. Material models have been developed to enhance predictive capabilities of fuel clad creep and growth, along with deeper understanding of zirconium alloy clad oxidation and hydrogen pickup. Understanding of corrosion chemistry (e.g., CRUD formation) has evolved at all scales: micro, meso and macro. CFD R&D has focused on improvement in closure models for subcooled boiling and bubbly flow, and the formulation of robust numerical solution algorithms. For multiphysics integration, several iterative acceleration methods have been assessed, illuminating areas where further research is needed. Finally, uncertainty quantification and data assimilation techniques, based upon sampling approaches, have been made more feasible for practicing nuclear engineers via R&D on dimensional reduction and biased sampling. Industry adoption of CASL's evolving M

  6. An experimental Toxoplasma gondii dose response challenge model to study therapeutic or vaccine efficacy in cats.

    Directory of Open Access Journals (Sweden)

    Jan B W J Cornelissen

    Full Text Available High numbers of Toxoplasma gondii oocysts in the environment are a risk factor to humans. The environmental contamination might be reduced by vaccinating the definitive host, cats. An experimental challenge model is necessary to quantitatively assess the efficacy of a vaccine or drug treatment. Previous studies have indicated that bradyzoites are highly infectious for cats. To infect cats, tissue cysts were isolated from the brains of mice infected with oocysts of T. gondii M4 strain, and bradyzoites were released by pepsin digestion. Free bradyzoites were counted and graded doses (1000, 100, 50, 10, and 250 intact tissue cysts were inoculated orally into three cats each. Oocysts shed by these five groups of cats were collected from faeces by flotation techniques, counted microscopically and estimated by real time PCR. Additionally, the number of T. gondii in heart, tongue and brains were estimated, and serology for anti T. gondii antibodies was performed. A Beta-Poisson dose-response model was used to estimate the infectivity of single bradyzoites and linear regression was used to determine the relation between inoculated dose and numbers of oocyst shed. We found that real time PCR was more sensitive than microscopic detection of oocysts, and oocysts were detected by PCR in faeces of cats fed 10 bradyzoites but by microscopic examination. Real time PCR may only detect fragments of T. gondii DNA without the presence of oocysts in low doses. Prevalence of tissue cysts of T. gondii in tongue, heart and brains, and anti T. gondii antibody concentrations were all found to depend on the inoculated bradyzoite dose. The combination of the experimental challenge model and the dose response analysis provides a suitable reference for quantifying the potential reduction in human health risk due to a treatment of domestic cats by vaccination or by therapeutic drug application.

  7. Hyperresolution Global Land Surface Modeling: Meeting a Grand Challenge for Monitoring Earth's Terrestrial Water

    Science.gov (United States)

    Wood, Eric F.; Roundy, Joshua K.; Troy, Tara J.; van Beek, L. P. H.; Bierkens, Marc F. P.; 4 Blyth, Eleanor; de Roo, Ad; Doell. Petra; Ek, Mike; Famiglietti, James; hide

    2011-01-01

    Monitoring Earth's terrestrial water conditions is critically important to many hydrological applications such as global food production; assessing water resources sustainability; and flood, drought, and climate change prediction. These needs have motivated the development of pilot monitoring and prediction systems for terrestrial hydrologic and vegetative states, but to date only at the rather coarse spatial resolutions (approx.10-100 km) over continental to global domains. Adequately addressing critical water cycle science questions and applications requires systems that are implemented globally at much higher resolutions, on the order of 1 km, resolutions referred to as hyperresolution in the context of global land surface models. This opinion paper sets forth the needs and benefits for a system that would monitor and predict the Earth's terrestrial water, energy, and biogeochemical cycles. We discuss six major challenges in developing a system: improved representation of surface-subsurface interactions due to fine-scale topography and vegetation; improved representation of land-atmospheric interactions and resulting spatial information on soil moisture and evapotranspiration; inclusion of water quality as part of the biogeochemical cycle; representation of human impacts from water management; utilizing massively parallel computer systems and recent computational advances in solving hyperresolution models that will have up to 10(exp 9) unknowns; and developing the required in situ and remote sensing global data sets. We deem the development of a global hyperresolution model for monitoring the terrestrial water, energy, and biogeochemical cycles a grand challenge to the community, and we call upon the international hydrologic community and the hydrological science support infrastructure to endorse the effort.

  8. Modelling marine sediment biogeochemistry: Current knowledge gaps, challenges, and some methodological advice for advancement

    DEFF Research Database (Denmark)

    Lessin, Gennadi; Artioli, Yuri; Almroth-Rosell, Elin

    2018-01-01

    The benthic environment is a crucial component of marine systems in the provision of ecosystem services, sustaining biodiversity and in climate regulation, and therefore important to human society. With the contemporary increase in computational power, model resolution and technological improveme......The benthic environment is a crucial component of marine systems in the provision of ecosystem services, sustaining biodiversity and in climate regulation, and therefore important to human society. With the contemporary increase in computational power, model resolution and technological...... improvements in quality and quantity of benthic data, it is necessary to ensure that benthic systems are appropriately represented in coupled benthic-pelagic biogeochemical and ecological modelling studies. In this paper we focus on five topical challenges related to various aspects of modelling benthic...... environments: organic matter reactivity, dynamics of benthic-pelagic boundary layer, microphytobenthos, biological transport and small-scale heterogeneity, and impacts of episodic events. We discuss current gaps in their understanding and indicate plausible ways ahead. Further, we propose a three...

  9. Multiscale Mechanics of Articular Cartilage: Potentials and Challenges of Coupling Musculoskeletal, Joint, and Microscale Computational Models

    Science.gov (United States)

    Halloran, J. P.; Sibole, S.; van Donkelaar, C. C.; van Turnhout, M. C.; Oomens, C. W. J.; Weiss, J. A.; Guilak, F.; Erdemir, A.

    2012-01-01

    Articular cartilage experiences significant mechanical loads during daily activities. Healthy cartilage provides the capacity for load bearing and regulates the mechanobiological processes for tissue development, maintenance, and repair. Experimental studies at multiple scales have provided a fundamental understanding of macroscopic mechanical function, evaluation of the micromechanical environment of chondrocytes, and the foundations for mechanobiological response. In addition, computational models of cartilage have offered a concise description of experimental data at many spatial levels under healthy and diseased conditions, and have served to generate hypotheses for the mechanical and biological function. Further, modeling and simulation provides a platform for predictive risk assessment, management of dysfunction, as well as a means to relate multiple spatial scales. Simulation-based investigation of cartilage comes with many challenges including both the computational burden and often insufficient availability of data for model development and validation. This review outlines recent modeling and simulation approaches to understand cartilage function from a mechanical systems perspective, and illustrates pathways to associate mechanics with biological function. Computational representations at single scales are provided from the body down to the microstructure, along with attempts to explore multiscale mechanisms of load sharing that dictate the mechanical environment of the cartilage and chondrocytes. PMID:22648577

  10. Integrated Payment And Delivery Models Offer Opportunities And Challenges For Residential Care Facilities.

    Science.gov (United States)

    Grabowski, David C; Caudry, Daryl J; Dean, Katie M; Stevenson, David G

    2015-10-01

    Under health care reform, new financing and delivery models are being piloted to integrate health and long-term care services for older adults. Programs using these models generally have not included residential care facilities. Instead, most of them have focused on long-term care recipients in the community or the nursing home. Our analyses indicate that individuals living in residential care facilities have similarly high rates of chronic illness and Medicare utilization when compared with matched individuals in the community and nursing home, and rates of functional dependency that fall between those of their counterparts in the other two settings. These results suggest that the residential care facility population could benefit greatly from models that coordinated health and long-term care services. However, few providers have invested in the infrastructure needed to support integrated delivery models. Challenges to greater care integration include the private-pay basis for residential care facility services, which precludes shared savings from reduced Medicare costs, and residents' preference for living in a home-like, noninstitutional environment. Project HOPE—The People-to-People Health Foundation, Inc.

  11. Challenges of Representing Sub-Grid Physics in an Adaptive Mesh Refinement Atmospheric Model

    Science.gov (United States)

    O'Brien, T. A.; Johansen, H.; Johnson, J. N.; Rosa, D.; Benedict, J. J.; Keen, N. D.; Collins, W.; Goodfriend, E.

    2015-12-01

    Some of the greatest potential impacts from future climate change are tied to extreme atmospheric phenomena that are inherently multiscale, including tropical cyclones and atmospheric rivers. Extremes are challenging to simulate in conventional climate models due to existing models' coarse resolutions relative to the native length-scales of these phenomena. Studying the weather systems of interest requires an atmospheric model with sufficient local resolution, and sufficient performance for long-duration climate-change simulations. To this end, we have developed a new global climate code with adaptive spatial and temporal resolution. The dynamics are formulated using a block-structured conservative finite volume approach suitable for moist non-hydrostatic atmospheric dynamics. By using both space- and time-adaptive mesh refinement, the solver focuses computational resources only where greater accuracy is needed to resolve critical phenomena. We explore different methods for parameterizing sub-grid physics, such as microphysics, macrophysics, turbulence, and radiative transfer. In particular, we contrast the simplified physics representation of Reed and Jablonowski (2012) with the more complex physics representation used in the System for Atmospheric Modeling of Khairoutdinov and Randall (2003). We also explore the use of a novel macrophysics parameterization that is designed to be explicitly scale-aware.

  12. Challenges to achieving sustainable community health development within a donor aid business model.

    Science.gov (United States)

    Ashwell, Helen; Barclay, Lesley

    2010-06-01

    This paper explores the paradox of donor aid being delivered through a business model through a case study in Papua New Guinea. A retrospective review of project implementation and an outcome evaluation provided an opportunity to examine the long-term results and sustainability of a large project. Analysis was informed by data collected from 175 interviews (national, provincial, district and village), 93 community discussions and observations across 10 provinces. Problems with the business model of delivering aid were evident from implementation data and in an evaluation conducted two years after project completion (2006). Compounding the business model effect were challenges of over-ambitious project goals with limited flexibility to adapt to changing circumstances, a donor payment system requiring short-term productivity and excessive reporting requirements. An overly ambitious project design, donor dominance within the business model and limited local counterpart capacity created problems in the community initiatives component of the project. Contractual pressures can negatively influence long-term outcomes that require development of local leadership and capacity. Future planning for donor project designs needs to be flexible, smaller in scope and have a longer timeframe of seven to 10 years. Donor-funded projects need to be sufficiently flexible to apply proven principles of community development, build local ownership and allow adequate time to build counterpart knowledge and skills.

  13. Review article: Hydrological modeling in glacierized catchments of central Asia - status and challenges

    Science.gov (United States)

    Chen, Yaning; Li, Weihong; Fang, Gonghuan; Li, Zhi

    2017-02-01

    Meltwater from glacierized catchments is one of the most important water supplies in central Asia. Therefore, the effects of climate change on glaciers and snow cover will have increasingly significant consequences for runoff. Hydrological modeling has become an indispensable research approach to water resources management in large glacierized river basins, but there is a lack of focus in the modeling of glacial discharge. This paper reviews the status of hydrological modeling in glacierized catchments of central Asia, discussing the limitations of the available models and extrapolating these to future challenges and directions. After reviewing recent efforts, we conclude that the main sources of uncertainty in assessing the regional hydrological impacts of climate change are the unreliable and incomplete data sets and the lack of understanding of the hydrological regimes of glacierized catchments of central Asia. Runoff trends indicate a complex response to changes in climate. For future variation of water resources, it is essential to quantify the responses of hydrologic processes to both climate change and shrinking glaciers in glacierized catchments, and scientific focus should be on reducing uncertainties linked to these processes.

  14. The challenge of modeling fuel–coolant interaction: Part II – Steam explosion

    Energy Technology Data Exchange (ETDEWEB)

    Meignen, Renaud, E-mail: renaud.meignen@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, IRSN/PSN-RES/SAG, BP 3, 13115 Saint-Paul-Lez-Durance Cedex (France); Raverdy, Bruno [Institut de Radioprotection et de Sûreté Nucléaire, IRSN/PSN-RES/SAG, BP 3, 13115 Saint-Paul-Lez-Durance Cedex (France); Picchi, Stephane; Lamome, Julien [Communication and Systèmes, 22 avenue Galilée, 92350 Le Plessis Robinson (France)

    2014-12-15

    Highlights: • We present the status modeling of steam explosion in the computer code MC3D (a first paper is devoted to premixing stage of FCI). • We also propose a general state of the art, highlighting recent improvements in understanding and modeling, remaining difficulties, controversies and needs. • We highlight the need for improving the understanding of the melt fragmentation and oxidation. • The verification basis is presented. - Abstract: In the course of a severe accident in a nuclear power plant cooled or moderated by water, the core might melt and flow down into the water. Under certain circumstances, a steam explosion might develop during the mixing of the melt and the water. Such an explosion, if occurring in the reactor pit of a PWR or BWR, might challenge the containment integrity and is thus an important issue for nuclear safety. This paper aims at presenting both a status of research and understanding of the phenomenon and the main characteristics of the models developed in the 3-dimensional computer code MC3D. We make a particular emphasis on the underlying difficulties, uncertainties and needs for further improvements. We discuss more particularly the two major phenomena that are the fine fragmentation and the pressurization process. We also give insights on the impact of melt solidification on the fragmentation and on the issue of oxidation. The verification basis of the models is discussed and finally, an example of 3D calculation is presented to highlight the current code capabilities.

  15. High resolution weather data for urban hydrological modelling and impact assessment, ICT requirements and future challenges

    Science.gov (United States)

    ten Veldhuis, Marie-claire; van Riemsdijk, Birna

    2013-04-01

    presentation will highlight ICT-related requirements and limitations in high resolution urban hydrological modelling and analysis. Further ICT challenges arise in provision of high resolution radar data for diverging information needs as well as in combination with other data sources in the urban environment. Different types of information are required for such diverse activities as operational flood protection, traffic management, large event organisation, business planning in shopping districts and restaurants, timing of family activities. These different information needs may require different configurations and data processing for radars and other data sources. An ICT challenge is to develop techniques for deciding how to automatically respond to these diverging information needs (e.g., through (semi-)automated negotiation). Diverse activities also provide a wide variety of information resources that can supplement traditional networks of weather sensors, such as rain sensors on cars and social media. Another ICT challenge is how to combine data from these different sources for answering a particular information need. Examples will be presented of solutions are currently being explored.

  16. Intravenous Transplantation of Mesenchymal Stromal Cells to Enhance Peripheral Nerve Regeneration

    Directory of Open Access Journals (Sweden)

    Stella M. Matthes

    2013-01-01

    Full Text Available Peripheral nerve injury is a common and devastating complication after trauma and can cause irreversible impairment or even complete functional loss of the affected limb. While peripheral nerve repair results in some axonal regeneration and functional recovery, the clinical outcome is not optimal and research continues to optimize functional recovery after nerve repair. Cell transplantation approaches are being used experimentally to enhance regeneration. Intravenous infusion of mesenchymal stromal cells (MSCs into spinal cord injury and stroke was shown to improve functional outcome. However, the repair potential of intravenously transplanted MSCs in peripheral nerve injury has not been addressed yet. Here we describe the impact of intravenously infused MSCs on functional outcome in a peripheral nerve injury model. Rat sciatic nerves were transected followed, by intravenous MSCs transplantation. Footprint analysis was carried out and 21 days after transplantation, the nerves were removed for histology. Labelled MSCs were found in the sciatic nerve lesion site after intravenous injection and regeneration was improved. Intravenously infused MSCs after acute peripheral nerve target the lesion site and survive within the nerve and the MSC treated group showed greater functional improvement. The results of study suggest that nerve repair with cell transplantation could lead to greater functional outcome.

  17. Coupled Atmosphere-Wave-Ocean Modeling of Tropical Cyclones: Progress, Challenges, and Ways Forward

    Science.gov (United States)

    Chen, Shuyi

    2015-04-01

    /s. It is found that the air-sea fluxes are quite asymmetric around a storm with complex features representing various air-sea interaction processes in TCs. A unique observation in Typhoon Fanapi is the development of a stable boundary layer in the near-storm cold wake region, which has a direct impact on TC inner core structure and intensity. Despite of the progress, challenges remain. Air-sea momentum exchange in wind speed greater than 30-40 m/s is largely unresolved. Directional wind-wave stress and wave-current stress are difficult to determine from observations. Effects of sea spray on the air-sea fluxes are still not well understood. This talk will provide an overview on progress made in recent years, challenges we are facing, and ways forward. An integrated coupled observational and atmosphere-wave-ocean modeling system is urgently needed, in which coupled model development and targeted observations from field campaign and lab measurements together form the core of the research and prediction system. Another important aspect is that fully coupled models provide explicit, integrated impact forecasts of wind, rain, waves, ocean currents and surges in TCs and winter storms, which are missing in most current NWP models. It requires a new strategy for model development, evaluation, and verification. Ensemble forecasts using high-resolution coupled atmosphere-wave-ocean models can provide probabilistic forecasts and quantitative uncertainty estimates, which also allow us to explore new methodologies to verify probabilistic impact forecasts and evaluate model physics using a stochastic approach. Examples of such approach in TCs including Superstorm Sandy will be presented.

  18. Building Information Modelling: Challenges and Barriers in Implement of BIM for Interior Design Industry in Malaysia

    Science.gov (United States)

    Hamid, A. B. Abd; Taib, M. Z. Mohd; Razak, A. H. N. Abdul; Embi, M. R.

    2018-04-01

    Building Information Modelling (BIM) is an innovative approach that has developed crossways the global in architecture, engineering and construction (AEC) industry. The construction industry of Malaysia has undergone a rapid development and dynamic technology adoption in advance and methods between the players industry and stakeholders. Consequently, limited technologies and devices have not been successful as it should have been. This study will be emphasizing scenarios of challenges and barriers in adopting BIM in interior design industry in Malaysia. The study was emphasizing the challenges and barriers in BIM usage from the designer’s perspective. The data are collected through the questionnaires as to identifying the barriers, knowledge, readiness and awareness and distributed to interior design firms were selected randomly. The finding of this research is to examine the barriers and causes of variables BIM usage for interior design industry in Malaysia. The outcome of this study is to identify the constraint of adoption BIM in interior design industry compare to others players in same industry.

  19. Multi -omics and metabolic modelling pipelines: challenges and tools for systems microbiology.

    Science.gov (United States)

    Fondi, Marco; Liò, Pietro

    2015-02-01

    Integrated -omics approaches are quickly spreading across microbiology research labs, leading to (i) the possibility of detecting previously hidden features of microbial cells like multi-scale spatial organization and (ii) tracing molecular components across multiple cellular functional states. This promises to reduce the knowledge gap between genotype and phenotype and poses new challenges for computational microbiologists. We underline how the capability to unravel the complexity of microbial life will strongly depend on the integration of the huge and diverse amount of information that can be derived today from -omics experiments. In this work, we present opportunities and challenges of multi -omics data integration in current systems biology pipelines. We here discuss which layers of biological information are important for biotechnological and clinical purposes, with a special focus on bacterial metabolism and modelling procedures. A general review of the most recent computational tools for performing large-scale datasets integration is also presented, together with a possible framework to guide the design of systems biology experiments by microbiologists. Copyright © 2015. Published by Elsevier GmbH.

  20. A Comprehensive Study on the Internet of Underwater Things: Applications, Challenges, and Channel Models

    Directory of Open Access Journals (Sweden)

    Chien-Chi Kao

    2017-06-01

    Full Text Available The Internet of Underwater Things (IoUT is a novel class of Internet of Things (IoT, and is defined as the network of smart interconnected underwater objects. IoUT is expected to enable various practical applications, such as environmental monitoring, underwater exploration, and disaster prevention. With these applications, IoUT is regarded as one of the potential technologies toward developing smart cities. To support the concept of IoUT, Underwater Wireless Sensor Networks (UWSNs have emerged as a promising network system. UWSNs are different from the traditional Territorial Wireless Sensor Networks (TWSNs, and have several unique properties, such as long propagation delay, narrow bandwidth, and low reliability. These unique properties would be great challenges for IoUT. In this paper, we provide a comprehensive study of IoUT, and the main contributions of this paper are threefold: (1 we introduce and classify the practical underwater applications that can highlight the importance of IoUT; (2 we point out the differences between UWSNs and traditional TWSNs, and these differences are the main challenges for IoUT; and (3 we investigate and evaluate the channel models, which are the technical core for designing reliable communication protocols on IoUT.

  1. A Comprehensive Study on the Internet of Underwater Things: Applications, Challenges, and Channel Models.

    Science.gov (United States)

    Kao, Chien-Chi; Lin, Yi-Shan; Wu, Geng-De; Huang, Chun-Ju

    2017-06-22

    The Internet of Underwater Things (IoUT) is a novel class of Internet of Things (IoT), and is defined as the network of smart interconnected underwater objects. IoUT is expected to enable various practical applications, such as environmental monitoring, underwater exploration, and disaster prevention. With these applications, IoUT is regarded as one of the potential technologies toward developing smart cities. To support the concept of IoUT, Underwater Wireless Sensor Networks (UWSNs) have emerged as a promising network system. UWSNs are different from the traditional Territorial Wireless Sensor Networks (TWSNs), and have several unique properties, such as long propagation delay, narrow bandwidth, and low reliability. These unique properties would be great challenges for IoUT. In this paper, we provide a comprehensive study of IoUT, and the main contributions of this paper are threefold: (1) we introduce and classify the practical underwater applications that can highlight the importance of IoUT; (2) we point out the differences between UWSNs and traditional TWSNs, and these differences are the main challenges for IoUT; and (3) we investigate and evaluate the channel models, which are the technical core for designing reliable communication protocols on IoUT.

  2. Methodological challenges and analytic opportunities for modeling and interpreting Big Healthcare Data.

    Science.gov (United States)

    Dinov, Ivo D

    2016-01-01

    Managing, processing and understanding big healthcare data is challenging, costly and demanding. Without a robust fundamental theory for representation, analysis and inference, a roadmap for uniform handling and analyzing of such complex data remains elusive. In this article, we outline various big data challenges, opportunities, modeling methods and software techniques for blending complex healthcare data, advanced analytic tools, and distributed scientific computing. Using imaging, genetic and healthcare data we provide examples of processing heterogeneous datasets using distributed cloud services, automated and semi-automated classification techniques, and open-science protocols. Despite substantial advances, new innovative technologies need to be developed that enhance, scale and optimize the management and processing of large, complex and heterogeneous data. Stakeholder investments in data acquisition, research and development, computational infrastructure and education will be critical to realize the huge potential of big data, to reap the expected information benefits and to build lasting knowledge assets. Multi-faceted proprietary, open-source, and community developments will be essential to enable broad, reliable, sustainable and efficient data-driven discovery and analytics. Big data will affect every sector of the economy and their hallmark will be 'team science'.

  3. Challenges in modeling spatiotemporally varying phytoplankton blooms in the Northwestern Arabian Sea and Gulf of Oman

    Science.gov (United States)

    Sedigh Marvasti, S.; Gnanadesikan, A.; Bidokhti, A. A.; Dunne, J. P.; Ghader, S.

    2016-02-01

    Recent years have shown an increase in harmful algal blooms in the Northwest Arabian Sea and Gulf of Oman, raising the question of whether climate change will accelerate this trend. This has led us to examine whether the Earth System Models used to simulate phytoplankton productivity accurately capture bloom dynamics in this region - both in terms of the annual cycle and interannual variability. Satellite data (SeaWIFS ocean color) show two climatological blooms in this region, a wintertime bloom peaking in February and a summertime bloom peaking in September. On a regional scale, interannual variability of the wintertime bloom is dominated by cyclonic eddies which vary in location from one year to another. Two coarse (1°) models with the relatively complex biogeochemistry (TOPAZ) capture the annual cycle but neither eddies nor the interannual variability. An eddy-resolving model (GFDL CM2.6) with a simpler biogeochemistry (miniBLING) displays larger interannual variability, but overestimates the wintertime bloom and captures eddy-bloom coupling in the south but not in the north. The models fail to capture both the magnitude of the wintertime bloom and its modulation by eddies in part because of their failure to capture the observed sharp thermocline and/or nutricline in this region. When CM2.6 is able to capture such features in the Southern part of the basin, eddies modulate diffusive nutrient supply to the surface (a mechanism not previously emphasized in the literature). For the model to simulate the observed wintertime blooms within cyclones, it will be necessary to represent this relatively unusual nutrient structure as well as the cyclonic eddies. This is a challenge in the Northern Arabian Sea as it requires capturing the details of the outflow from the Persian Gulf - something that is poorly done in global models.

  4. Intravenous/oral ciprofloxacin therapy versus intravenous ceftazidime therapy for selected bacterial infections.

    Science.gov (United States)

    Gaut, P L; Carron, W C; Ching, W T; Meyer, R D

    1989-11-30

    The efficacy and toxicity of sequential intravenous and oral ciprofloxacin therapy was compared with intravenously administered ceftazidime in a prospective, randomized, controlled, non-blinded trial. Thirty-two patients (16 patients receiving ciprofloxacin and 16 patients receiving ceftazidime) with 38 infections caused by susceptible Pseudomonas aeruginosa, enteric gram-negative rods, Salmonella group B, Serratia marcescens, Pseudomonas cepacia, and Xanthomonas maltophilia at various sites were evaluable for determination of efficacy. Length of therapy varied from seven to 25 days. Concomitant antimicrobials included intravenously administered beta-lactams for gram-positive organisms, intravenous/oral metronidazole and clindamycin for anaerobes, and intravenous/local amphotericin B for Candida albicans. Intravenous administration of 200 mg ciprofloxacin every 12 hours to 11 patients produced peak serum levels between 1.15 and 3.12 micrograms/ml; trough levels ranged between 0.08 and 0.86 micrograms/ml. Overall response rates were similar for patients receiving ciprofloxacin and ceftazidime. Emergence of resistance was similar in both groups--one Enterobacter cloacae and two P. aeruginosa became resistant after ciprofloxacin therapy and two P. aeruginosa became resistant after ceftazidime therapy. The frequency of superinfection with a variety of organisms was also similar in both groups. Adverse events related to ciprofloxacin included transient pruritus at the infusion site and generalized rash leading to drug discontinuation (one patient each), and with ceftazidime adverse effects included pain at the site of infusion and the development of allergic interstitial nephritis (one patient each). Overall, intravenous/oral ciprofloxin therapy appears to be as safe and effective as intravenous ceftazidime therapy in the treatment of a variety of infections due to susceptible aerobic gram-negative organisms.

  5. Challenges and Conundrums in Modeling Global Methane Emissions from Wetlands: An Empiricist's Viewpoint

    Science.gov (United States)

    Bridgham, S. D.

    2015-12-01

    Wetlands emit a third to half of the global CH4 flux and have the largest uncertainty of any emission source. Moreover, wetlands have provided an important radiative feedback to climate in the geologic and recent past. A number of largescale wetland CH4 models have been developed recently, but intermodel comparisons show wide discrepancies in their predictions. I present an empiricist's overview of the current limitations and challenges of more accurately modeling wetland CH4 emissions. One of the largest limitations is simply the poor knowledge of wetland area, with estimated global values varying by a more than a factor of three. The areas of seasonal and tropical wetlands are particularly poorly constrained. There are also few wetlands with complete, multi-year datasets for all of the input variables for many models, and this lack of data is particularly alarming in tropical wetlands given that they are arguably the single largest natural or anthropogenic global CH4 source. Almost all largescale CH4 models have little biogeochemical mechanistic detail and treat anaerobic carbon cycling in a highly simplified manner. The CH4:CO2 ratio in anaerobic carbon mineralization is a central parameter in many models, but is at most set at a few values with no mechanistic underpinning. However, empirical data show that this ratio varies by five orders of magnitude in different wetlands, and tropical wetlands appear to be particularly methanogenic, all for reasons that are very poorly understood. The predominance of the acetoclastic pathway of methanogenesis appears to be related to total CH4 production, but different methanogenesis pathways are generally not incorporated into models. Other important anaerobic processes such as humic substances acting as terminal electron acceptors, fermentation, homoacetogenesis, and anaerobic CH4 oxidation are also not included in most models despite evidence of their importance in empirical studies. Moreover, there has been an explosion

  6. Operational use of distributed hydrological models. Experiences and challenges at a Norwegian hydropower company (Agder Energi).

    Science.gov (United States)

    Viggo Matheussen, Bernt; Andresen, Arne; Weisser, Claudia

    2014-05-01

    combined into a robust and fast data cleansing and interpolation system. One experience from this work is that advanced interpolation techniques (kriging), do not outperform calibrated inverse distance methods when also computational speed is used as a criteria for model selection. The paper also discusses several challenges related to uncertainty in simulated snow reservoir, regionalization of parameters, choice of spatial resolution, techniques for reducing computational needs without compromising information needs, amongst others.

  7. Inversion-based propofol dosing for intravenous induction of hypnosis

    Science.gov (United States)

    Padula, F.; Ionescu, C.; Latronico, N.; Paltenghi, M.; Visioli, A.; Vivacqua, G.

    2016-10-01

    In this paper we propose an inversion-based methodology for the computation of a feedforward action for the propofol intravenous administration during the induction of hypnosis in general anesthesia. In particular, the typical initial bolus is substituted with a command signal that is obtained by predefining a desired output and by applying an input-output inversion procedure. The robustness of the method has been tested by considering a set of patients with different model parameters, which is representative of a large population.

  8. New Sustainable Model of Biorefineries: Biofactories and Challenges of Integrating Bio- and Solar Refineries.

    Science.gov (United States)

    Abate, Salvatore; Lanzafame, Paola; Perathoner, Siglinda; Centi, Gabriele

    2015-09-07

    The new scenario for sustainable (low-carbon) chemical and energy production drives the development of new biorefinery concepts (indicated as biofactories) with chemical production at the core, but flexible and small-scale production. An important element is also the integration of solar energy and CO2 use within biobased production. This concept paper, after shortly introducing the motivation and recent trends in this area, particularly at the industrial scale, and some of the possible models (olefin and intermediate/high-added-value chemicals production), discusses the opportunities and needs for research to address the challenge of integrating bio- and solar refineries. Aspects discussed regard the use of microalgae and CO2 valorization in biorefineries/biofactories by chemo- or biocatalysis, including possibilities for their synergetic cooperation and symbiosis, as well as integration within the agroenergy value chain. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Challenges of electricity production scenarios modelling for life cycle assessment of environmental impacts

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, Isabelle; Beloin-Saint-Pierre, Didier [MINES ParisTech, Sophia Antipolis (France). Observation, Impacts, Energy Center

    2013-07-01

    This communication presents a first attempt at making a life cycle assessment of prospective electricity production scenarios which were designed in the EnerGEO project. We start by a basic review of system (in this case, scenario) modelling expectations in today's LCA study. We then review some of the challenges of implementation due to the lack of detailed description of present and future electricity production systems. The importance of a detailed description is then shown with an evaluation of uncertainty of life cycle impact assessment results for three scenarios of German electricity production in 2030. The significant uncertainties we found, prevent us from detecting a relevant trend or making any comparison between the three chosen scenarios. We finally come to the conclusion that the LCA methodology will become relevant for the environmental assessment of electricity production scenarios when many more detailed information are accounted to describe future technologies, structures and sources of energy. (orig.)

  10. Modern challenges for flow investigations in model hydraulic turbines on classical test rig

    International Nuclear Information System (INIS)

    Deschênes, C; Houde, S; Aeschlimann, V; Fraser, R; Ciocan, G D

    2014-01-01

    The BulbT project involved several investigations of flow phenomena in different parts of a model bulb turbine installed on the test rig of Laval University Laboratory. The aim is to create a comprehensive data base in order to increase the knowledge of the flow phenomena in this type of turbines and to validate or improve numerical flow simulation strategies. This validation being based on a kinematic comparison between experimental and numerical data, the project had to overcome challenges to facilitate the use of the experimental data for that purpose. Many parameters were checked, such as the test bench repeatability, the intrusiveness of a priori non-intrusive methods, the geometry of the runner and draft tube. This paper illustrates how some of those problematic were solved

  11. Police Training in El Salvador: Challenges and Opportunities in Promoting the Community Police Model

    Directory of Open Access Journals (Sweden)

    Luisa Carolina Arévalo Herrera

    2014-05-01

    Full Text Available The Peace Accords emphasized creating a new police force that would be diametrically opposite to previous security forces. This change would have to be expressed symbolically, and from the onset it would have to underscore the fact that the main weapon of the police would be intelligence. From its foundation to June 2011, a total of 30,344 people have graduated from the Academy. Currently, in the process of training new police with greater quality, and modernizing the entire police force, it faces the difficult challenge of adopting the Community Police philosophy to empower this model for action, promoting a new relationship between community and law enforcement, and between managers and operational personnel in the agency. Nevertheless,police training is not enough if there are no significantchanges in the organizational climate and culture within the law enforcement agency.DOI: http://dx.doi.org/10.5377/rpsp.v1i1.1390

  12. Challenges of electricity production scenarios modelling for life cycle assessment of environmental impacts

    International Nuclear Information System (INIS)

    Blanc, Isabelle; Beloin-Saint-Pierre, Didier

    2013-01-01

    This communication presents a first attempt at making a life cycle assessment of prospective electricity production scenarios which were designed in the EnerGEO project. We start by a basic review of system (in this case, scenario) modelling expectations in today's LCA study. We then review some of the challenges of implementation due to the lack of detailed description of present and future electricity production systems. The importance of a detailed description is then shown with an evaluation of uncertainty of life cycle impact assessment results for three scenarios of German electricity production in 2030. The significant uncertainties we found, prevent us from detecting a relevant trend or making any comparison between the three chosen scenarios. We finally come to the conclusion that the LCA methodology will become relevant for the environmental assessment of electricity production scenarios when many more detailed information are accounted to describe future technologies, structures and sources of energy. (orig.)

  13. Industrial-Strength Model-Based Testing - State of the Art and Current Challenges

    Directory of Open Access Journals (Sweden)

    Jan Peleska

    2013-03-01

    Full Text Available As of today, model-based testing (MBT is considered as leading-edge technology in industry. We sketch the different MBT variants that - according to our experience - are currently applied in practice, with special emphasis on the avionic, railway and automotive domains. The key factors for successful industrial-scale application of MBT are described, both from a scientific and a managerial point of view. With respect to the former view, we describe the techniques for automated test case, test data and test procedure generation for concurrent reactive real-time systems which are considered as the most important enablers for MBT in practice. With respect to the latter view, our experience with introducing MBT approaches in testing teams are sketched. Finally, the most challenging open scientific problems whose solutions are bound to improve the acceptance and effectiveness of MBT in industry are discussed.

  14. Induced Pluripotency and Gene Editing in Disease Modelling: Perspectives and Challenges

    Science.gov (United States)

    Seah, Yu Fen Samantha; EL Farran, Chadi A.; Warrier, Tushar; Xu, Jian; Loh, Yuin-Han

    2015-01-01

    Embryonic stem cells (ESCs) are chiefly characterized by their ability to self-renew and to differentiate into any cell type derived from the three main germ layers. It was demonstrated that somatic cells could be reprogrammed to form induced pluripotent stem cells (iPSCs) via various strategies. Gene editing is a technique that can be used to make targeted changes in the genome, and the efficiency of this process has been significantly enhanced by recent advancements. The use of engineered endonucleases, such as homing endonucleases, zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and Cas9 of the CRISPR system, has significantly enhanced the efficiency of gene editing. The combination of somatic cell reprogramming with gene editing enables us to model human diseases in vitro, in a manner considered superior to animal disease models. In this review, we discuss the various strategies of reprogramming and gene targeting with an emphasis on the current advancements and challenges of using these techniques to model human diseases. PMID:26633382

  15. Current Challenges in the First Principle Quantitative Modelling of the Lower Hybrid Current Drive in Tokamaks

    Science.gov (United States)

    Peysson, Y.; Bonoli, P. T.; Chen, J.; Garofalo, A.; Hillairet, J.; Li, M.; Qian, J.; Shiraiwa, S.; Decker, J.; Ding, B. J.; Ekedahl, A.; Goniche, M.; Zhai, X.

    2017-10-01

    The Lower Hybrid (LH) wave is widely used in existing tokamaks for tailoring current density profile or extending pulse duration to steady-state regimes. Its high efficiency makes it particularly attractive for a fusion reactor, leading to consider it for this purpose in ITER tokamak. Nevertheless, if basics of the LH wave in tokamak plasma are well known, quantitative modeling of experimental observations based on first principles remains a highly challenging exercise, despite considerable numerical efforts achieved so far. In this context, a rigorous methodology must be carried out in the simulations to identify the minimum number of physical mechanisms that must be considered to reproduce experimental shot to shot observations and also scalings (density, power spectrum). Based on recent simulations carried out for EAST, Alcator C-Mod and Tore Supra tokamaks, the state of the art in LH modeling is reviewed. The capability of fast electron bremsstrahlung, internal inductance li and LH driven current at zero loop voltage to constrain all together LH simulations is discussed, as well as the needs of further improvements (diagnostics, codes, LH model), for robust interpretative and predictive simulations.

  16. Interoperability challenges in river discharge modelling: A cross domain application scenario

    Science.gov (United States)

    Santoro, Mattia; Andres, Volker; Jirka, Simon; Koike, Toshio; Looser, Ulrich; Nativi, Stefano; Pappenberger, Florian; Schlummer, Manuela; Strauch, Adrian; Utech, Michael; Zsoter, Ervin

    2018-06-01

    River discharge is a critical water cycle variable, as it integrates all the processes (e.g. runoff and evapotranspiration) occurring within a river basin and provides a hydrological output variable that can be readily measured. Its prediction is of invaluable help for many water-related tasks including water resources assessment and management, flood protection, and disaster mitigation. Observations of river discharge are important to calibrate and validate hydrological or coupled land, atmosphere and ocean models. This requires using datasets from different scientific domains (Water, Weather, etc.). Typically, such datasets are provided using different technological solutions. This complicates the integration of new hydrological data sources into application systems. Therefore, a considerable effort is often spent on data access issues instead of the actual scientific question. This paper describes the work performed to address multidisciplinary interoperability challenges related to river discharge modeling and validation. This includes definition and standardization of domain specific interoperability standards for hydrological data sharing and their support in global frameworks such as the Global Earth Observation System of Systems (GEOSS). The research was developed in the context of the EU FP7-funded project GEOWOW (GEOSS Interoperability for Weather, Ocean and Water), which implemented a "River Discharge" application scenario. This scenario demonstrates the combination of river discharge observations data from the Global Runoff Data Centre (GRDC) database and model outputs produced by the European Centre for Medium-Range Weather Forecasts (ECMWF) predicting river discharge based on weather forecast information in the context of the GEOSS.

  17. Challenges and models in supporting logistics system design for dedicated-biomass-based bioenergy industry.

    Science.gov (United States)

    Zhu, Xiaoyan; Li, Xueping; Yao, Qingzhu; Chen, Yuerong

    2011-01-01

    This paper analyzed the uniqueness and challenges in designing the logistics system for dedicated biomass-to-bioenergy industry, which differs from the other industries, due to the unique features of dedicated biomass (e.g., switchgrass) including its low bulk density, restrictions on harvesting season and frequency, content variation with time and circumambient conditions, weather effects, scattered distribution over a wide geographical area, and so on. To design it, this paper proposed a mixed integer linear programming model. It covered from planting and harvesting switchgrass to delivering to a biorefinery and included the residue handling, concentrating on integrating strategic decisions on the supply chain design and tactical decisions on the annual operation schedules. The present numerical examples verified the model and demonstrated its use in practice. This paper showed that the operations of the logistics system were significantly different for harvesting and non-harvesting seasons, and that under the well-designed biomass logistics system, the mass production with a steady and sufficient supply of biomass can increase the unit profit of bioenergy. The analytical model and practical methodology proposed in this paper will help realize the commercial production in biomass-to-bioenergy industry. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. Induced Pluripotency and Gene Editing in Disease Modelling: Perspectives and Challenges

    Directory of Open Access Journals (Sweden)

    Yu Fen Samantha Seah

    2015-12-01

    Full Text Available Embryonic stem cells (ESCs are chiefly characterized by their ability to self-renew and to differentiate into any cell type derived from the three main germ layers. It was demonstrated that somatic cells could be reprogrammed to form induced pluripotent stem cells (iPSCs via various strategies. Gene editing is a technique that can be used to make targeted changes in the genome, and the efficiency of this process has been significantly enhanced by recent advancements. The use of engineered endonucleases, such as homing endonucleases, zinc finger nucleases (ZFNs, transcription activator-like effector nucleases (TALENs and Cas9 of the CRISPR system, has significantly enhanced the efficiency of gene editing. The combination of somatic cell reprogramming with gene editing enables us to model human diseases in vitro, in a manner considered superior to animal disease models. In this review, we discuss the various strategies of reprogramming and gene targeting with an emphasis on the current advancements and challenges of using these techniques to model human diseases.

  19. A systematic review and checklist presenting the main challenges for health economic modeling in personalized medicine: towards implementing patient-level models.

    Science.gov (United States)

    Degeling, Koen; Koffijberg, Hendrik; IJzerman, Maarten J

    2017-02-01

    The ongoing development of genomic medicine and the use of molecular and imaging markers in personalized medicine (PM) has arguably challenged the field of health economic modeling (HEM). This study aims to provide detailed insights into the current status of HEM in PM, in order to identify if and how modeling methods are used to address the challenges described in literature. Areas covered: A review was performed on studies that simulate health economic outcomes for personalized clinical pathways. Decision tree modeling and Markov modeling were the most observed methods. Not all identified challenges were frequently found, challenges regarding companion diagnostics, diagnostic performance, and evidence gaps were most often found. However, the extent to which challenges were addressed varied considerably between studies. Expert commentary: Challenges for HEM in PM are not yet routinely addressed which may indicate that either (1) their impact is less severe than expected, (2) they are hard to address and therefore not managed appropriately, or (3) HEM in PM is still in an early stage. As evidence on the impact of these challenges is still lacking, we believe that more concrete examples are needed to illustrate the identified challenges and to demonstrate methods to handle them.

  20. Longitudinal Omics Modelling and Integration in Clinical Metabonomics Research: challenges in childhood metabolic health research

    Directory of Open Access Journals (Sweden)

    Peter eSperisen

    2015-08-01

    Full Text Available Systems biology is an important approach for deciphering the complex processes in health maintenance and the etiology of metabolic diseases. Such integrative methodologies will help better understand the molecular mechanisms involved in growth and development throughout childhood, and consequently will result in new insights about metabolic and nutritional requirements of infants, children and adults. To achieve this, a better understanding of the physiological processes at anthropometric, cellular and molecular level for any given individual is needed. In this respect, novel omics technologies in combination with sophisticated data modelling techniques are key. Due to the highly complex network of influential factors determining individual trajectories, it becomes imperative to develop proper tools and solutions that will comprehensively model biological information related to growth and maturation of our body functions. The aim of this review and perspective is to evaluate, succinctly, promising data analysis approaches to enable data integration for clinical research, with an emphasis on the longitudinal component. Approaches based on empirical and mechanistic modelling of omics data are essential to leverage findings from high dimensional omics datasets and enable biological interpretation and clinical translation. On the one hand, empirical methods, which provide quantitative descriptions of patterns in the data, are mostly used for exploring and mining datasets. On the other hand, mechanistic models are based on an understanding of the behavior of a system’s components and condense information about the known functions, allowing robust and reliable analyses to be performed by bioinformatics pipelines and similar tools. Herein, we will illustrate current examples, challenges and perspectives in the applications of empirical and mechanistic modelling in the context of childhood metabolic health research.

  1. The challenge of modeling fuel–coolant interaction: Part I – Premixing

    Energy Technology Data Exchange (ETDEWEB)

    Meignen, Renaud, E-mail: renaud.meignen@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, IRSN/PSN-RES/SAG, BP 3, 13115 Saint-Paul-Lez-Durance Cedex (France); Picchi, Stephane; Lamome, Julien [Communication and Systèmes, 22 avenue Galilée, 92350 Le Plessis Robinson (France); Raverdy, Bruno [IRSN/PSN-RES/SAG, BP3, 92362 Fontenay aux Roses Cedex (France); Escobar, Sebastian Castrillon [Institut de Radioprotection et de Sûreté Nucléaire, IRSN/PSN-RES/SAG, BP 3, 13115 Saint-Paul-Lez-Durance Cedex (France); Nicaise, Gregory [IRSN/PSN-RES/SAG, BP3, 92362 Fontenay aux Roses Cedex (France)

    2014-12-15

    Highlights: • We present the status modeling of the fuel–coolant interaction premixing stage in the computer code MC3D. • We also propose a general state of the art, highlighting recent improvements in understanding and modeling, remaining difficulties, controversies and needs. • We highlight the need for improving the understanding of the melt fragmentation and oxidation. • The verification basis is presented. - Abstract: Fuel–coolant interaction is a complex mixing process that can occur during the course of a severe accident in a nuclear power plant involving core melting and relocation. Under certain circumstances, a steam explosion might develop during the mixing of the melt and the water and induce a loss of integrity of the containment. Even in the absence of an explosion, studying the mixing phenomenon is also of high interest due to its strong impact on the progression of the accident (debris bed formation, hydrogen production). This article is the first of two aiming at presenting both a status of research and understanding of fuel–coolant interaction and the main characteristics of the model developed in the 3-dimensional computer code MC3D. It is devoted to the premixing phase whereas the second is related to the explosion phase. A special attention is given to major difficulties, uncertainties and needs for further improvements in knowledge and modeling. We discuss more particularly the major phenomena that are melt fragmentation and film boiling heat transfer and the challenges related to modeling melt solidification and oxidation. Some highlights related to the code verification are finally given.

  2. Optimal timing for intravenous administration set replacement.

    Science.gov (United States)

    Gillies, D; O'Riordan, L; Wallen, M; Morrison, A; Rankin, K; Nagy, S

    2005-10-19

    Administration of intravenous therapy is a common occurrence within the hospital setting. Routine replacement of administration sets has been advocated to reduce intravenous infusion contamination. If decreasing the frequency of changing intravenous administration sets does not increase infection rates, a change in practice could result in considerable cost savings. The objective of this review was to identify the optimal interval for the routine replacement of intravenous administration sets when infusate or parenteral nutrition (lipid and non-lipid) solutions are administered to people in hospital via central or peripheral venous catheters. We searched The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, CINAHL, EMBASE: all from inception to February 2004; reference lists of identified trials, and bibliographies of published reviews. We also contacted researchers in the field. We did not have a language restriction. We included all randomized or quasi-randomized controlled trials addressing the frequency of replacing intravenous administration sets when parenteral nutrition (lipid and non-lipid containing solutions) or infusions (excluding blood) were administered to people in hospital via a central or peripheral catheter. Two authors assessed all potentially relevant studies. We resolved disagreements between the two authors by discussion with a third author. We collected data for the outcomes; infusate contamination; infusate-related bloodstream infection; catheter contamination; catheter-related bloodstream infection; all-cause bloodstream infection and all-cause mortality. We identified 23 references for review. We excluded eight of these studies; five because they did not fit the inclusion criteria and three because of inadequate data. We extracted data from the remaining 15 references (13 studies) with 4783 participants. We conclude that there is no evidence that changing intravenous administration sets more often than every 96 hours

  3. Digital Model-Based Engineering: Expectations, Prerequisites, and Challenges of Infusion

    Science.gov (United States)

    Hale, J. P.; Zimmerman, P.; Kukkala, G.; Guerrero, J.; Kobryn, P.; Puchek, B.; Bisconti, M.; Baldwin, C.; Mulpuri, M.

    2017-01-01

    Digital model-based engineering (DMbE) is the use of digital artifacts, digital environments, and digital tools in the performance of engineering functions. DMbE is intended to allow an organization to progress from documentation-based engineering methods to digital methods that may provide greater flexibility, agility, and efficiency. The term 'DMbE' was developed as part of an effort by the Model-Based Systems Engineering (MBSE) Infusion Task team to identify what government organizations might expect in the course of moving to or infusing MBSE into their organizations. The Task team was established by the Interagency Working Group on Engineering Complex Systems, an informal collaboration among government systems engineering organizations. This Technical Memorandum (TM) discusses the work of the MBSE Infusion Task team to date. The Task team identified prerequisites, expectations, initial challenges, and recommendations for areas of study to pursue, as well as examples of efforts already in progress. The team identified the following five expectations associated with DMbE infusion, discussed further in this TM: (1) Informed decision making through increased transparency, and greater insight. (2) Enhanced communication. (3) Increased understanding for greater flexibility/adaptability in design. (4) Increased confidence that the capability will perform as expected. (5) Increased efficiency. The team identified the following seven challenges an organization might encounter when looking to infuse DMbE: (1) Assessing value added to the organization. Not all DMbE practices will be applicable to every situation in every organization, and not all implementations will have positive results. (2) Overcoming organizational and cultural hurdles. (3) Adopting contractual practices and technical data management. (4) Redefining configuration management. The DMbE environment changes the range of configuration information to be managed to include performance and design models

  4. Design Challenges of an Episode-Based Payment Model in Oncology: The Centers for Medicare & Medicaid Services Oncology Care Model.

    Science.gov (United States)

    Kline, Ronald M; Muldoon, L Daniel; Schumacher, Heidi K; Strawbridge, Larisa M; York, Andrew W; Mortimer, Laura K; Falb, Alison F; Cox, Katherine J; Bazell, Carol; Lukens, Ellen W; Kapp, Mary C; Rajkumar, Rahul; Bassano, Amy; Conway, Patrick H

    2017-07-01

    The Centers for Medicare & Medicaid Services developed the Oncology Care Model as an episode-based payment model to encourage participating practitioners to provide higher-quality, better-coordinated care at a lower cost to the nearly three-quarter million fee-for-service Medicare beneficiaries with cancer who receive chemotherapy each year. Episode payment models can be complex. They combine into a single benchmark price all payments for services during an episode of illness, many of which may be delivered at different times by different providers in different locations. Policy and technical decisions include the definition of the episode, including its initiation, duration, and included services; the identification of beneficiaries included in the model; and beneficiary attribution to practitioners with overall responsibility for managing their care. In addition, the calculation and risk adjustment of benchmark episode prices for the bundle of services must reflect geographic cost variations and diverse patient populations, including varying disease subtypes, medical comorbidities, changes in standards of care over time, the adoption of expensive new drugs (especially in oncology), as well as diverse practice patterns. Other steps include timely monitoring and intervention as needed to avoid shifting the attribution of beneficiaries on the basis of their expected episode expenditures as well as to ensure the provision of necessary medical services and the development of a meaningful link to quality measurement and improvement through the episode-based payment methodology. The complex and diverse nature of oncology business relationships and the specific rules and requirements of Medicare payment systems for different types of providers intensify these issues. The Centers for Medicare & Medicaid Services believes that by sharing its approach to addressing these decisions and challenges, it may facilitate greater understanding of the model within the oncology

  5. Challenges for modelling spatio-temporal variations of malaria risk in Malawi

    Science.gov (United States)

    Lowe, R.; Chirombo, J.; Tompkins, A. M.

    2012-04-01

    Malaria is the leading cause of morbidity and mortality in Malawi with more than 6 million episodes reported each year. Malaria poses a huge economic burden to Malawi in terms of the direct cost of treating malaria patients and also indirect costs resulting from workdays lost in agriculture and industry and absenteeism from school. Malawi implements malaria control activities within the Roll Back Malaria framework, with the objective to provide those most at risk (i.e. children under five years, pregnant woman and individuals with suppressed immune systems) access to personal and community protective measures. However, at present there is no mechanism by which to target the most 'at risk' populations ahead of an impending epidemic. Malaria transmission is influenced by variations in meteorological conditions, which impact the biology of the mosquito and the availability of breeding sites, but also socio-economic conditions such as levels of urbanisation, poverty and education, which influence human vulnerability and vector habitat. The many potential drivers of malaria, both extrinsic, such as climate, and intrinsic, such as population immunity are often difficult to disentangle. This presents a challenge for modelling of malaria risk in space and time. Using an age-stratified spatio-temporal dataset of malaria cases at the district level from July 2004 - June 2011, we use a spatio-temporal modelling framework to model variations in malaria risk in Malawi. Climatic and topographic variations are accounted for using an interpolation method to relate gridded products to administrative districts. District level data is tested in the model to account for confounding factors, including the proportion of the population living in urban areas; residing in traditional housing; with no toilet facilities; who do not attend school, etc, the number of health facilities per population and yearly estimates of insecticide-treated mosquito net distribution. In order to account for

  6. A Yersinia pestis tat mutant is attenuated in bubonic and small-aerosol pneumonic challenge models of infection but not as attenuated by intranasal challenge.

    Directory of Open Access Journals (Sweden)

    Joel Bozue

    Full Text Available Bacterial proteins destined for the Tat pathway are folded before crossing the inner membrane and are typically identified by an N-terminal signal peptide containing a twin arginine motif. Translocation by the Tat pathway is dependent on the products of genes which encode proteins possessing the binding site of the signal peptide and mediating the actual translocation event. In the fully virulent CO92 strain of Yersinia pestis, the tatA gene was deleted. The mutant was assayed for loss of virulence through various in vitro and in vivo assays. Deletion of the tatA gene resulted in several consequences for the mutant as compared to wild-type. Cell morphology of the mutant bacteria was altered and demonstrated a more elongated form. In addition, while cultures of the mutant strain were able to produce a biofilm, we observed a loss of adhesion of the mutant biofilm structure compared to the biofilm produced by the wild-type strain. Immuno-electron microscopy revealed a partial disruption of the F1 antigen on the surface of the mutant. The virulence of the ΔtatA mutant was assessed in various murine models of plague. The mutant was severely attenuated in the bubonic model with full virulence restored by complementation with the native gene. After small-particle aerosol challenge in a pneumonic model of infection, the mutant was also shown to be attenuated. In contrast, when mice were challenged intranasally with the mutant, very little difference in the LD50 was observed between wild-type and mutant strains. However, an increased time-to-death and delay in bacterial dissemination was observed in mice infected with the ΔtatA mutant as compared to the parent strain. Collectively, these findings demonstrate an essential role for the Tat pathway in the virulence of Y. pestis in bubonic and small-aerosol pneumonic infection but less important role for intranasal challenge.

  7. Challenges in modelling spatiotemporally varying phytoplankton blooms in the Northwestern Arabian Sea and Gulf of Oman

    Science.gov (United States)

    Sedigh Marvasti, S.; Gnanadesikan, A.; Bidokhti, A. A.; Dunne, J. P.; Ghader, S.

    2015-07-01

    We examine interannual variability of phytoplankton blooms in northwestern Arabian Sea and Gulf of Oman. Satellite data (SeaWIFS ocean color) shows two climatological blooms in this region, a wintertime bloom peaking in February and a summertime bloom peaking in September. A pronounced anti-correlation between the AVISO sea surface height anomaly (SSHA) and chlorophyll is found during the wintertime bloom. On a regional scale, interannual variability of the wintertime bloom is thus dominated by cyclonic eddies which vary in location from one year to another. These results were compared against the outputs from three different 3-D Earth System models. We show that two coarse (1°) models with the relatively complex biogeochemistry (TOPAZ) capture the annual cycle but neither eddies nor the interannual variability. An eddy-resolving model (GFDL CM2.6) with a simpler biogeochemistry (miniBLING) displays larger interannual variability, but overestimates the wintertime bloom and captures eddy-bloom coupling in the south but not in the north. The southern part of the domain is a region with a much sharper thermocline and nutricline relatively close to the surface, in which eddies modulate diffusive nutrient supply to the surface (a mechanism not previously emphasized in the literature). We suggest that for the model to simulate the observed wintertime blooms within cyclones, it will be necessary to represent this relatively unusual nutrient structure as well as the cyclonic eddies. This is a challenge in the Northern Arabian Sea as it requires capturing the details of the outflow from the Persian Gulf.

  8. Characterization of an intravenously injected bolus

    International Nuclear Information System (INIS)

    Samuel, A.M.; Raikar, U.R.; Atmaram, S.H.; Ganatra, R.D.

    1976-01-01

    A study of some parameters affecting the time activity histogram of an intravenous bolus injection of radioactivity was performed. A scoring system for bolus compactness was attempted. A score of 2 and above was considered to be a satisfactory bolus. Volumes less than 1 ml tended to result in a satisfactory bolus. The nature of radiopharmaceutical injected, different injecters and age of the patient did not affect the score. Thyrotoxic patients gave the best bolus score. (orig.) [de

  9. Nuclear Power Plant Life Management - Challenges and Proposal for a Unified Model Integrating Safety and Economics

    International Nuclear Information System (INIS)

    Contri, Paolo; Elsing, Bernhard

    2011-01-01

    In recent years many electric utilities and nuclear power plants adopted policies for improved coordination of both safety and non-safety programs, called plant life management (PLIM), also in view on plant life extension programs, but mainly for an optimisation of operating costs. The implementation of PLIM programs has followed many different approaches, being intrinsically dependent on the national regulatory framework and technical traditions. In Countries with some experience, the PLIM program proved very convenient, especially when coupled with Maintenance, Surveillance an Inspection (MS and I) optimization: average savings are reported in the range of 20-30% of total (maintenance) costs. A unified European model for PLIM was developed at the JRC-Institute for Energy with the support of a network of stakeholders (SENUF), and validated at some EU nuclear plants. This paper provides a summary of the model features, the result of its validation at some plants and summarises the perceived scientific/technological challenges on which JRC proposes to focus, based upon its competencies and skills, having in mind both the European and world-wide context and its potential evolution. (author)

  10. Challenges and gaps for energy planning models in the developing-world context

    Science.gov (United States)

    Debnath, Kumar Biswajit; Mourshed, Monjur

    2018-03-01

    Energy planning models (EPMs) support multi-criteria assessments of the impact of energy policies on the economy and environment. Most EPMs originated in developed countries and are primarily aimed at reducing greenhouse gas emissions while enhancing energy security. In contrast, most, if not all, developing countries are predominantly concerned with increasing energy access. Here, we review thirty-four widely used EPMs to investigate their applicability to developing countries and find an absence of consideration of the objectives, challenges, and nuances of the developing context. Key deficiencies arise from the lack of deliberation of the low energy demand resulting from lack of access and availability of supply. Other inadequacies include the lack of consideration of socio-economic nuances such as the prevalence of corruption and resulting cost inflation, the methods for adequately addressing the shortcomings in data quality, availability and adequacy, and the effects of climate change. We argue for further research on characterization and modelling of suppressed demand, climate change impacts, and socio-political feedback in developing countries, and the development of contextual EPMs.

  11. W(h)ither the Oracle? Cognitive biases and other human challenges of integrated environmental modeling

    Science.gov (United States)

    Glynn, Pierre D.; Ames, D.P.; Quinn, N. W. T.; Rizzoli, A.E.

    2014-01-01

    Integrated environmental modeling (IEM) can organize and increase our knowledge of the complex, dynamic ecosystems that house our natural resources and control the quality of our environments. Human behavior, however, must be taken into account. Human biases/heuristics reflect adaptation over our evolutionary past to frequently experienced situations that affected our survival and that provided sharply distinguished feedbacks at the level of the individual. Unfortunately, human behavior is not adapted to the more diffusely experienced, less frequently encountered, problems and issues that IEM typically seeks to address in the simulation of natural resources and environments. While seeking inspiration from the prophetic traditions of the Oracle of Delphi, several human biases are identified that may affect how the science base of IEM is assembled, and how IEM results are interpreted and used. These biases are supported by personal observations, and by the findings of behavioral scientists. A process for critical analysis is proposed that solicits explicit accounting and cognizance of potential human biases. A number of suggestions are made to address the human challenges of IEM, in addition to maintaining attitudes of watchful humility, open-mindedness, honesty, and transparent accountability. These include creating a new area of study in the behavioral biogeosciences, using structured processes for engaging the modeling and stakeholder community in IEM, and using “red teams” to increase resilience of IEM constructs and use.

  12. Challenges in modelling the random structure correctly in growth mixture models and the impact this has on model mixtures.

    Science.gov (United States)

    Gilthorpe, M S; Dahly, D L; Tu, Y K; Kubzansky, L D; Goodman, E

    2014-06-01

    Lifecourse trajectories of clinical or anthropological attributes are useful for identifying how our early-life experiences influence later-life morbidity and mortality. Researchers often use growth mixture models (GMMs) to estimate such phenomena. It is common to place constrains on the random part of the GMM to improve parsimony or to aid convergence, but this can lead to an autoregressive structure that distorts the nature of the mixtures and subsequent model interpretation. This is especially true if changes in the outcome within individuals are gradual compared with the magnitude of differences between individuals. This is not widely appreciated, nor is its impact well understood. Using repeat measures of body mass index (BMI) for 1528 US adolescents, we estimated GMMs that required variance-covariance constraints to attain convergence. We contrasted constrained models with and without an autocorrelation structure to assess the impact this had on the ideal number of latent classes, their size and composition. We also contrasted model options using simulations. When the GMM variance-covariance structure was constrained, a within-class autocorrelation structure emerged. When not modelled explicitly, this led to poorer model fit and models that differed substantially in the ideal number of latent classes, as well as class size and composition. Failure to carefully consider the random structure of data within a GMM framework may lead to erroneous model inferences, especially for outcomes with greater within-person than between-person homogeneity, such as BMI. It is crucial to reflect on the underlying data generation processes when building such models.

  13. Meeting the challenges of bringing a new base facility operation model to Gemini Observatory

    Science.gov (United States)

    Nitta, Atsuko; Arriagada, Gustavo; Adamson, A. J.; Cordova, Martin; Nunez, Arturo; Serio, Andrew; Kleinman, Scot

    2016-08-01

    The aim of the Gemini Observatory's Base Facilities Project is to provide the capabilities to perform routine night time operations with both telescopes and their instruments from their respective base facilities without anyone present at the summit. Tightening budget constraints prompted this project as both a means to save money and an opportunity to move toward increasing remote operations in the future. We successfully moved Gemini North nighttime operation to our base facility in Hawaii in Nov., 2015. This is the first 8mclass telescope to completely move night time operations to base facility. We are currently working on implementing BFO to Gemini South. Key challenges for this project include: (1) This is a schedule driven project. We have to implement the new capabilities by the end of 2015 for Gemini North and end of 2016 for Gemini South. (2) The resources are limited and shared with operations which has the higher priority than our project. (3) Managing parallel work within the project. (4) Testing, commissioning and introducing new tools to operational systems without adding significant disruptions to nightly operations. (5) Staff buying to the new operational model. (6) The staff involved in the project are spread on two locations separated by 10,000km, seven time zones away from each other. To overcome these challenges, we applied two principles: "Bare Minimum" and "Gradual Descent". As a result, we successfully completed the project ahead of schedule at Gemini North Telescope. I will discuss how we managed the cultural and human aspects of the project through these concepts. The other management aspects will be presented by Gustavo Arriagada [2], the Project Manager of this project. For technical details, please see presentations from Andrew Serio [3] and Martin Cordova [4].

  14. Successful outcome after intravenous gasoline injection.

    Science.gov (United States)

    Domej, Wolfgang; Mitterhammer, Heike; Stauber, Rudolf; Kaufmann, Peter; Smolle, Karl Heinz

    2007-12-01

    Gasoline, ingested intentionally or accidentally, is toxic. The majority of reported cases of gasoline intoxication involve oral ingestion or inhalation. Data are scarce on complications and outcomes following hydrocarbon poisoning by intravenous injection. Following a suicide attempt by intravenous self-injection of 10 ml of gasoline, a 26-year-old medical student was admitted to the intensive care unit (ICU) with hemoptysis, symptoms of acute respiratory failure, chest pain, and severe abdominal cramps. Gas exchange was severely impaired and a chest x-ray indicated chemical pneumonitis. Initial treatment consisted of mechanical ventilation, supportive hyperventilation, administration of nitrogen oxide (NO), and prednisone. Unfortunately, the patient developed multi-organ dysfunction syndrome (MODS) complicated by life-threatening severe vasoplegia within 24 hours after gasoline injection. High doses of vasopressors along with massive amounts of parenteral fluids were necessary. Despite fluid replacement, renal function worsened and required hemofiltration on 5 sequential days. After 12 days of intensive care management, the patient recovered completely and was discharged to a psychiatric care facility. Intravenous gasoline injection causes major injury to the lungs, the organ bearing the first capillary bed encountered. Treatment of gasoline poisoning is symptomatic because no specific antidote is available. Early and aggressive supportive care may be conducive to a favorable outcome with minimal residual pulmonary sequelae.

  15. Contrast agent choice for intravenous coronary angiography

    International Nuclear Information System (INIS)

    Zeman, H.D.; Siddons, D.P.

    1989-01-01

    The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with monochromatic synchrotron radiation x-rays and an iodine containing contrast agent at the Stanford Synchrotron Radiation Laboratory have shown that such an intravenous angiography procedure would be possible with an adequately intense monochromatic x-ray source. Because of the size and cost of synchrotron radiation facilities it would be desirable to make the most efficient use of the intensity available, while reducing as much as possible the radiation dose experienced by the patient. By choosing contrast agents containing elements with a higher atomic number than iodine, it is possible to both improve the image quality and reduce the patient radiation dose, while using the same synchrotron source. By using Si monochromator crystals with a small mosaic spread, it is possible to increase the x-ray flux available for imaging by over an order of magnitude, without any changes in the storage ring or wiggler magnet. The most critical imaging task for intravenous coronary angiography utilizing synchrotron radiation x-rays is visualizing a coronary artery through the left ventricle or aorta which also contains a contrast agent. Calculations have been made of the signal to noise ratio expected for this imaging task for various contrast agents with atomic numbers between that of iodine and bismuth

  16. Influences on physicians' choices of intravenous colloids.

    Science.gov (United States)

    Miletin, Michael S; Stewart, Thomas E; Norton, Peter G

    2002-07-01

    Controversy over the optimal intravenous fluid for volume resuscitation continues unabated. Our objectives were to characterize the demographics of physicians who prescribe intravenous colloids and determine factors that enter into their decision to choose a colloid. Questionnaire with 61 items. Ten percent ( n = 364) of frequent intravenous fluid prescribers in the province of Ontario, Canada. The response rate was 74%. Colloid use in the past year was reported by 79% of the responding physicians. Important reasons for choosing a colloid included blood loss and manipulation of oncotic pressure. Physicians tended to prefer either albumin or pentastarch, but no important reasons were found for choosing between the two. Albumin with or without crystalloid was preferred in 5/13 scenarios by more than 50% of the respondents, whereas pentastarch was not favored by more than 50% of respondents in any scenario. Physicians practising in critical care areas and teaching hospitals generally preferred pentastarch to albumin. Physicians reporting pentastarch as representing greater than 90% of total colloid use were more likely to have been visited by a drug detailer for pentastarch than those who used less synthetic colloid (54 vs 22%, p distribution. Although albumin appeared to be preferred in more clinical niches, most physicians did not state reasons for choosing between products. Marketing, specialty, location of practice and clinical scenario appear to play significant roles in the utilization of colloid products.

  17. 2008 GEM Modeling Challenge: Metrics Study of the Dst Index in Physics-Based Magnetosphere and Ring Current Models and in Statistical and Analytic Specifications

    Science.gov (United States)

    Rastaetter, L.; Kuznetsova, M.; Hesse, M.; Pulkkinen, A.; Glocer, A.; Yu, Y.; Meng, X.; Raeder, J.; Wiltberger, M.; Welling, D.; hide

    2011-01-01

    In this paper the metrics-based results of the Dst part of the 2008-2009 GEM Metrics Challenge are reported. The Metrics Challenge asked modelers to submit results for 4 geomagnetic storm events and 5 different types of observations that can be modeled by statistical or climatological or physics-based (e.g. MHD) models of the magnetosphere-ionosphere system. We present the results of over 25 model settings that were run at the Community Coordinated Modeling Center (CCMC) and at the institutions of various modelers for these events. To measure the performance of each of the models against the observations we use comparisons of one-hour averaged model data with the Dst index issued by the World Data Center for Geomagnetism, Kyoto, Japan, and direct comparison of one-minute model data with the one-minute Dst index calculated by the United States Geologic Survey (USGS).

  18. Infectious disease in cervids of North America: data, models, and management challenges.

    Science.gov (United States)

    Conner, Mary Margaret; Ebinger, Michael Ryan; Blanchong, Julie Anne; Cross, Paul Chafee

    2008-01-01

    Over the past two decades there has been a steady increase in the study and management of wildlife diseases. This trend has been driven by the perception of an increase in emerging zoonotic diseases and the recognition that wildlife can be a critical factor for controlling infectious diseases in domestic animals. Cervids are of recent concern because, as a group, they present a number of unique challenges. Their close ecological and phylogenetic relationship to livestock species places them at risk for receiving infections from, and reinfecting livestock. In addition, cervids are an important resource; revenue from hunting and viewing contribute substantially to agency budgets and local economies. A comprehensive coverage of infectious diseases in cervids is well beyond the scope of this chapter. In North America alone there are a number of infectious diseases that can potentially impact cervid populations, but for most of these, management is not feasible or the diseases are only a potential or future concern. We focus this chapter on three diseases that are of major management concern and the center of most disease research for cervids in North America: bovine tuberculosis, chronic wasting disease, and brucellosis. We discuss the available data and recent advances in modeling and management of these diseases.

  19. Antipsychotic activity of aqueous ethanolic extract of Tinospora Cordifolia in amphetamine challenged mice model

    Directory of Open Access Journals (Sweden)

    Bindu nee Giri Jain

    2010-01-01

    Full Text Available Tinospora cordifolia is reported to have CNS active principle and is used for the treatment of various neurological disorders. Hence, the effect of aqueous ethanolic extract of Tinospora cordifolia was investigated for its putative antipsychotic activity using amphetamine challenged mice model. Haloperidol (1 mg/kg i.p. was administered acutely to mice as standard drug. Control animals received vehicle (10% DMSO. The in vivo receptor binding studies were carried out to correlate the antipsychotic activity of the extract with its capacity to bind to the DAD2 receptor. The results in SLA showed that the hydro alcoholic extract of the stems of Tinospora cordifolia at a dose level of 250 mg/kg and 500 mg/kg showed no significant antipsychotic activity in amphetamine induced hyperactivity in mice when compared to standard. Extract alone treated group at a dos level of 250 mg/kg and 500 mg/kg showed a decreased in locomotor activity when compared to the control. The plant extract increased the DAD2 receptor binding in a dose dependent manner in treated mice compared to the control group.

  20. Integration of treatment innovation planning and implementation: strategic process models and organizational challenges.

    Science.gov (United States)

    Lehman, Wayne E K; Simpson, D Dwayne; Knight, Danica K; Flynn, Patrick M

    2011-06-01

    Sustained and effective use of evidence-based practices in substance abuse treatment services faces both clinical and contextual challenges. Implementation approaches are reviewed that rely on variations of plan-do-study-act (PDSA) cycles, but most emphasize conceptual identification of core components for system change strategies. A two-phase procedural approach is therefore presented based on the integration of Texas Christian University (TCU) models and related resources for improving treatment process and program change. Phase 1 focuses on the dynamics of clinical services, including stages of client recovery (cross-linked with targeted assessments and interventions), as the foundations for identifying and planning appropriate innovations to improve efficiency and effectiveness. Phase 2 shifts to the operational and organizational dynamics involved in implementing and sustaining innovations (including the stages of training, adoption, implementation, and practice). A comprehensive system of TCU assessments and interventions for client and program-level needs and functioning are summarized as well, with descriptions and guidelines for applications in practical settings. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

  1. Modeling of Materials for Energy Storage: A Challenge for Density Functional Theory

    Science.gov (United States)

    Kaltak, Merzuk; Fernandez-Serra, Marivi; Hybertsen, Mark S.

    Hollandite α-MnO2 is a promising material for rechargeable batteries and is studied extensively in the community because of its interesting tunnel structure and the corresponding large capacity for lithium as well as sodium ions. However, the presence of partially reduced Mn ions due to doping with Ag or during lithiation makes hollandite a challenging system for density functional theory and the conventionally employed PBE+U method. A naive attempt to model the ternary system LixAgyMnO2 with density functionals, similar to those employed for the case y = 0 , fails and predicts a strong monoclinic distortion of the experimentally observed tetragonal unit cell for Ag2Mn8O16. Structure and binding energies are compared with experimental data and show the importance of van der Waals interactions as well as the necessity for an accurate description of the cooperative Jan-Teller effects for silver hollandite AgyMnO2. Based on these observations a ternary phase diagram is calculated allowing to predict the physical and chemical properties of LixAgyMnO2, such as stable stoichiometries, open circuit voltages, the formation of Ag metal and the structural change during lithiation. Department of Energy (DOE) under award #DE-SC0012673.

  2. Satellites and Steep Slopes - the challenge of topography in the Himalaya - Karakorum for cryosphere models

    Science.gov (United States)

    Steiner, J. F.; Buri, P.; Miles, E. S.; Immerzeel, W.

    2016-12-01

    The topography in glaciated catchments in the Himalaya - Karakoram range are extreme in a number of aspects that proof to be a challenge for distributed modelling. High altitude regions, where accumulation areas of glaciers are generally located, can at times be very steep, covered in hanging ice and seasonal snow. On the other hand, lower areas, where ablation zones on glacier tongues are located, tend to be very shallow. This has consequences for obtaining glacier areas from satellite derived glacier inventories (e.g. RGI, ICIMOD). As they are taken perpendicular to the center of the earth, these inventories will underestimate the area of steep regions, sometimes quite considerably (Figure 1). This can have consequences for a number of statistics in glaciological modeling, especially when it comes to the relative comparison of accumulation and ablation and hence overall melt from a glacier. Additionally, these steep head walls cause topographic shading. Depending on the exposition of the valley this can result in very divergent amounts of direct solar radiation reaching the glacier surface from valley to valley. Comparisons of melt between different regions and even glaciers have to be taken with considerable caution. Finally, these shallow glacier tongues are increasingly covered in debris. Such glacier surfaces with a debris cover ranging in grain size from sand to boulders several meters in diameter are very hummocky rather than flat bare ice glacier surfaces. This in turn increases local shading but also increases the overall glacier surface. Using high resolution satellite imagery and DEMs ( 5m) from our field site we investigate the effects of areal misrepresentations on the local scale. Decreasing resolution we then take this analysis to the mountain range scale and can identify to what degree these factors are significant and considering literature values determine the quantitative impact for energy and mass balance studies. Figure 1: A schematic

  3. From California dreaming to California data: Challenging historic models for landfill CH4 emissions

    Directory of Open Access Journals (Sweden)

    Kurt Spokas

    2015-06-01

    Full Text Available Abstract Improved quantification of diverse CH4 sources at the urban scale is needed to guide local GHG mitigation strategies in the Anthropocene. Herein, we focus on landfill CH4 emissions in California, challenging the current IPCC methodology which focuses on a climate dependency for landfill CH4 generation (methanogenesis, but does not explicitly consider climate or soil dependencies for emissions. Relying on a comprehensive California landfill database, a field-validated process-based model for landfill CH4 emissions (CALMIM, and select field measurements at 10 California sites with a variety of methods, we support the contrary position: Limited climate dependency for methanogenesis, but strong climate dependency for landfill CH4 emissions. Contrary to the historic IPCC empirical model for methanogenesis with kinetic constants related to climate, we demonstrate a simpler and more robust linear empirical relationship (r2 = 0.85; n=128 between waste mass and landfill biogas recovery [126 × 10-6 Nm3 CH4 hr-1 Mgwaste-1]. More interestingly, there are no statistically significant relationships with climate, site age, or status (open/closed for landfill biogas recovery. The current IPCC methodology does not consider soil or climate drivers for gaseous transport or seasonal methanotrophy in different cover soils. On the other hand, we illustrate strong climate and soil dependencies for landfill emissions—e.g., average intermediate cover emissions below 20 g CH4 m-2 d-1 when the site’s mean annual precipitation is >500 mm y-1. Thereby, for the California landfill CH4 inventory, the highest-emitting sites shift from landfills containing the largest mass of waste to sites dominated by intermediate cover types having a reduced rate of soil CH4 oxidation during the annual cycle. These differences have profound implications for developing more realistic, science-based urban and regional scale GHG inventories for landfill CH4 while reducing

  4. Opportunity by Design: New High School Models for Student Success. Carnegie Challenge

    Science.gov (United States)

    Hamilton, Leah; Mackinnon, Anne

    2013-01-01

    The goal of Carnegie "Challenge" papers is to lift up ideas and issues in a way that elevates them to the nation's agenda. This paper is a "Challenge" paper, and serves as a call to realize the full power of the Common Core by redesigning and reshaping schools to support teachers and maximize key resources, rather than…

  5. Mycotic aneurysms in intravenous drug abusers: the utility of intravenous digital subtraction angiography

    International Nuclear Information System (INIS)

    Shetty, P.C.; Krasicky, G.A.; Sharma, R.P.; Vemuri, B.R.; Burke, M.M.

    1985-01-01

    Two-hundred thirteen intravenous digital subtraction angiographic (DSA) examinations were performed on 195 intravenous drug abusers to rule out the possibility of a mycotic aneurysm in a groin, neck, or upper extremity infection. Twenty-three surgically proved cases of mycotic aneurysm were correctly identified with no false positive results. In addition, six cases of major venous occlusion were documented. The authors present the results of their experience and conclude that DSA is an effective and cost-efficient method of examining this high risk patient population

  6. Photons, photosynthesis, and high-performance computing: challenges, progress, and promise of modeling metabolism in green algae

    International Nuclear Information System (INIS)

    Chang, C H; Graf, P; Alber, D M; Kim, K; Murray, G; Posewitz, M; Seibert, M

    2008-01-01

    The complexity associated with biological metabolism considered at a kinetic level presents a challenge to quantitative modeling. In particular, the relatively sparse knowledge of parameters for enzymes with known kinetic responses is problematic. The possible space of these parameters is of high-dimension, and sampling of such a space typifies a combinatorial explosion of possible dynamic states. However, with sufficient quantitative transcriptomics, proteomics, and metabolomics data at hand, these challenges could be met by high-performance software with sampling, fitting, and optimization capabilities. With this in mind, we present the High-Performance Systems Biology Toolkit HiPer SBTK, an evolving software package to simulate, fit, and optimize metabolite concentrations and fluxes within the space of rate and binding parameters associated with detailed enzyme kinetic models. We present our chosen modeling paradigm for the formulation of metabolic pathway models, the means to address the challenge of representing such models in a precise and persistent fashion using the standardized Systems Biology Markup Language, and our second-generation model of H2-associated Chlamydomonas metabolism. Processing of such models for hierarchically parallelized simulation and optimization, job specification by the user through a GUI interface, software capabilities and initial scaling data, and the mapping of the computation to biological questions is also discussed. Moreover, we present near-term future software and model development goals

  7. Methodological challenges to bridge the gap between regional climate and hydrology models

    Science.gov (United States)

    Bozhinova, Denica; José Gómez-Navarro, Juan; Raible, Christoph; Felder, Guido

    2017-04-01

    The frequency and severity of floods worldwide, together with their impacts, are expected to increase under climate change scenarios. It is therefore very important to gain insight into the physical mechanisms responsible for such events in order to constrain the associated uncertainties. Model simulations of the climate and hydrological processes are important tools that can provide insight in the underlying physical processes and thus enable an accurate assessment of the risks. Coupled together, they can provide a physically consistent picture that allows to assess the phenomenon in a comprehensive way. However, climate and hydrological models work at different temporal and spatial scales, so there are a number of methodological challenges that need to be carefully addressed. An important issue pertains the presence of biases in the simulation of precipitation. Climate models in general, and Regional Climate models (RCMs) in particular, are affected by a number of systematic biases that limit their reliability. In many studies, prominently the assessment of changes due to climate change, such biases are minimised by applying the so-called delta approach, which focuses on changes disregarding absolute values that are more affected by biases. However, this approach is not suitable in this scenario, as the absolute value of precipitation, rather than the change, is fed into the hydrological model. Therefore, bias has to be previously removed, being this a complex matter where various methodologies have been proposed. In this study, we apply and discuss the advantages and caveats of two different methodologies that correct the simulated precipitation to minimise differences with respect an observational dataset: a linear fit (FIT) of the accumulated distributions and Quantile Mapping (QM). The target region is Switzerland, and therefore the observational dataset is provided by MeteoSwiss. The RCM is the Weather Research and Forecasting model (WRF), driven at the

  8. Contrast agent choice for intravenous coronary angiography

    International Nuclear Information System (INIS)

    Zeman, H.D.; Siddons, D.P.

    1990-01-01

    The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with monochromatic synchrotron radiation X-rays and an iodine-containing contrast agent at the Stanford Synchrotron Radiation Laboratory have shown that such an intravenous angiography procedure would be possible with an adequately intense monochromatic X-ray source. Because of the size and cost of synchrotron radiation facilities it would be desirable to make the most efficient use of the intensity available, while reducing as much as possible the radiation dose experienced by the patient. By choosing contrast agents containing elements with a higher atomic number than iodine, it is possible to both improve the image quality and reduce the patient radiation dose, while using the same synchrotron radiation source. By using Si monochromator crystals with a small mosaic spread, it is possible to increase the X-ray flux available for imaging by over an order of magnitude, without any changes in the storage ring or wiggler magnet. The most critical imaging task for intravenous coronary angiography utilizing synchrotron radiation X-rays is visualizing a coronary artery through the left ventricle or aorta which also contain contrast agent. Calculations have been made of the signal to noise ratio expected for this imaging task for various contrast agents with atomic numbers between that of iodine and bismuth. The X-ray energy spectrum of the X-17 superconduction wiggler beam line at the National Synchrotron Light Source at Brookhaven National Laboratory has been used for these calculations. Both perfect Si crystals and Si crystals with a small mosaic spread are considered as monochromators. Contrast agents containing Gd or Yb seem to have about the optimal calculated signal to noise ratio. (orig./HSI)

  9. An Integrated Recovery-oriented Model (IRM) for mental health services: evolution and challenges.

    Science.gov (United States)

    Frost, Barry G; Tirupati, Srinivasan; Johnston, Suzanne; Turrell, Megan; Lewin, Terry J; Sly, Ketrina A; Conrad, Agatha M

    2017-01-17

    Over past decades, improvements in longer-term clinical and personal outcomes for individuals experiencing serious mental illness (SMI) have been moderate, although recovery has clearly been shown to be possible. Recovery experiences are inherently personal, and recovery can be complex and non-linear; however, there are a broad range of potential recovery contexts and contributors, both non-professional and professional. Ongoing refinement of recovery-oriented models for mental health (MH) services needs to be fostered. This descriptive paper outlines a service-wide Integrated Recovery-oriented Model (IRM) for MH services, designed to enhance personally valued health, wellbeing and social inclusion outcomes by increasing access to evidenced-based psychosocial interventions (EBIs) within a service context that supports recovery as both a process and an outcome. Evolution of the IRM is characterised as a series of five broad challenges, which draw together: relevant recovery perspectives; overall service delivery frameworks; psychiatric and psychosocial rehabilitation approaches and literature; our own clinical and service delivery experience; and implementation, evaluation and review strategies. The model revolves around the person's changing recovery needs, focusing on underlying processes and the service frameworks to support and reinforce hope as a primary catalyst for symptomatic and functional recovery. Within the IRM, clinical rehabilitation (CR) practices, processes and partnerships facilitate access to psychosocial EBIs to promote hope, recovery, self-agency and social inclusion. Core IRM components are detailed (remediation of functioning; collaborative restoration of skills and competencies; and active community reconnection), together with associated phases, processes, evaluation strategies, and an illustrative IRM scenario. The achievement of these goals requires ongoing collaboration with community organisations. Improved outcomes are achievable for

  10. Choice of intravenous contrast material for CT

    International Nuclear Information System (INIS)

    Cohen, M.D.; Herman, E.; Herron, D.; White, S.T.; Smith, J.A.; Cory, D.A.

    1989-01-01

    For CT, minor side effects (e.g., nausea, vomiting, pain) following intravenous administration of contrast medium may degrade image quality by causing patient motion or by delaying scanning. The objective of this study was to see if nonionic contrast agents offer advantages in reducing the incidence of such side effects. One hundred five pediatric patients randomly received iohexol (Omnipaque), Iopamidol (Isovue), or diatrizoate sodium (Hypaque). Contrast medium was given in doses of 2 mL/kg body weight (300 mg of iodine per milliliter). The results are presented in the paper

  11. [Intravenous ethyl alcohol in metabolic resuscitation].

    Science.gov (United States)

    Agolini, G; Lipartiti, T; Zaffiri, O; Musso, L; Belloni, G P

    1980-11-01

    Intravenously administered ethyl alcohol may be effective as analgesic and hypotensive peripheric vasoactive drug. In the Intensive Care Departments parenteral ethanol administration is infrequent because no "sure dosage" can be suggested in adults and children. Liver, kidney and C.N.S. diseases can worsen; foetopathy can follow. Drug-ethanol interaction may be particularly important for some patients admitted in Intensive Care Departments. Often the potential caloric support cannot be fully utilized ("empty" calories) and seldom hyperventilation, hyperlactacidemia and impaired protein synthesis can follow.

  12. INTRAVENOUS REGIONAL ANTIBIOTIC PERFUSION THERAPY AS AN ADJUNCTIVE TREATMENT FOR DIGITAL LESIONS IN SEABIRDS.

    Science.gov (United States)

    Fiorello, Christine V

    2017-03-01

    Foot infections are a common problem among seabirds in wildlife rehabilitation. Pododermatitis and digital infections are often challenging to treat because of the presence of suboptimal substrates, abnormal weight-bearing due to injuries, and suboptimal nutritional or health status. Seabirds represent the majority of animals requiring rehabilitation after oil spills, and foot problems are a common reason for euthanasia among these birds. Antibiotic intravenous regional perfusion therapy is frequently used in humans and other species to treat infections of the distal extremities, but it has not been evaluated in seabirds. During the 2015 Refugio oil spill response, four birds with foot lesions (pododermatitis, osteomyelitis, or both) were treated with ampicillin/sulbactam administered intravenously to the affected limb(s) in addition to systemic antibiotics and anti-inflammatories. Three of the birds, all brown pelicans ( Pelecanus occidentalis ) recovered rapidly and were released. Two of these birds had acute pododermatitis and were treated once with intravenous regional perfusion. They were released approximately 3 wk after the perfusion therapy. The third pelican had osteomyelitis of a digit. It was treated twice with intravenous regional perfusion and was released about 1 mo after the initial perfusion therapy. The fourth bird, a Pacific loon ( Gavia pacifica ), was treated once with perfusion therapy but did not respond to treatment and was euthanatized. No serious adverse effects were observed. This technique should be explored further in avian species.

  13. Mercury poisoning through intravenous administration: Two case reports with literature review.

    Science.gov (United States)

    Lu, Qiuying; Liu, Zilong; Chen, Xiaorui

    2017-11-01

    Metallic mercury poisoning through intravenous injection is rare, especially for a homicide attempt. Diagnosis and treatment of the disease are challenging. A 34-year-old male presented with pyrexia, chill, fatigue, body aches, and pain of the dorsal aspect of right foot. Another case is that of a 29-year-old male who committed suicide by injecting himself metallic mercury 15 g intravenously and presented with dizzy, dyspnea, fatigue, sweatiness, and waist soreness. The patient's condition in case 1 was deteriorated after initial treatment. Imaging studies revealed multiple high-density spots throughout the body especially in the lungs. On further questioning, the patient's girlfriend acknowledged that she injected him about 40 g mercury intravenously 11 days ago. The diagnosis was then confirmed with a urinary mercury concentration of 4828 mg/L. Surgical excision, continuous blood purification, plasma exchange, alveolar lavage, and chelation were performed successively in case 1. Blood irrigation and chelation therapy were performed in case 2. The laboratory test results and organ function of the patient in case 1 gradually returned to normal. However, in case 2, the patient's dyspnea was getting worse and he finally died due to toxic encephalopathy and respiratory failure. Early diagnosis and appropriate treatment are critical for intravenous mercury poisoning. It should be concerned about the combined use of chelation agents and other treatments, such as surgical excision, hemodialysis and plasma exchange in clinical settings.

  14. Grand challenge problems in environmental modeling and remediation: Groundwater contaminant transport. Final project report 1998

    International Nuclear Information System (INIS)

    1998-04-01

    The over-reaching goal of the Groundwater Grand Challenge component of the Partnership in Computational Science (PICS) was to develop and establish the massively parallel approach for the description of groundwater flow and transport and to address the problem of uncertainties in the data and its interpretation. This necessitated the development of innovative algorithms and the implementation of massively parallel computational tools to provide a suite of simulators for groundwater flow and transport in heterogeneous media. This report summarizes the activities and deliverables of the Groundwater Grand Challenge project funded through the High Performance Computing grand challenge program of the Department of Energy from 1995 through 1997

  15. Simulating the impacts of disturbances on forest carbon cycling in North America: processes, data, models, and challenges

    Science.gov (United States)

    Shuguang Liu; Ben Bond-Lamberty; Jeffrey A. Hicke; Rodrigo Vargas; Shuqing Zhao; Jing Chen; Steven L. Edburg; Yueming Hu; Jinxun Liu; A. David McGuire; Jingfeng Xiao; Robert Keane; Wenping Yuan; Jianwu Tang; Yiqi Luo; Christopher Potter; Jennifer Oeding

    2011-01-01

    Forest disturbances greatly alter the carbon cycle at various spatial and temporal scales. It is critical to understand disturbance regimes and their impacts to better quantify regional and global carbon dynamics. This review of the status and major challenges in representing the impacts of disturbances in modeling the carbon dynamics across North America revealed some...

  16. Challenges in Mentoring Software Development Projects in the High School: Analysis According to Shulman's Teacher Knowledge Base Model

    Science.gov (United States)

    Meerbaum-Salant, Orni; Hazzan, Orit

    2009-01-01

    This paper focuses on challenges in mentoring software development projects in the high school and analyzes difficulties encountered by Computer Science teachers in the mentoring process according to Shulman's Teacher Knowledge Base Model. The main difficulties that emerged from the data analysis belong to the following knowledge sources of…

  17. A Meta-Analysis of Video-Modeling Based Interventions for Reduction of Challenging Behaviors for Students with EBD

    Science.gov (United States)

    Losinski, Mickey; Wiseman, Nicole; White, Sherry A.; Balluch, Felicity

    2016-01-01

    The current study examined the use of video modeling (VM)-based interventions to reduce the challenging behaviors of students with emotional or behavioral disorders. Each study was evaluated using Council for Exceptional Children's (CEC's) quality indicators for evidence-based practices. In addition, study effects were calculated along the three…

  18. Challenges in understanding, modelling, and mitigating Lake Outburst Flood Hazard: experiences from Central Asia

    Science.gov (United States)

    Mergili, Martin; Schneider, Demian; Andres, Norina; Worni, Raphael; Gruber, Fabian; Schneider, Jean F.

    2010-05-01

    Lake Outburst Floods can evolve from complex process chains like avalanches of rock or ice that produce flood waves in a lake which may overtop and eventually breach glacial, morainic, landslide, or artificial dams. Rising lake levels can lead to progressive incision and destabilization of a dam, to enhanced ground water flow (piping), or even to hydrostatic failure of ice dams which can cause sudden outflow of accumulated water. These events often have a highly destructive potential because a large amount of water is released in a short time, with a high capacity to erode loose debris, leading to a powerful debris flow with a long travel distance. The best-known example of a lake outburst flood is the Vajont event (Northern Italy, 1963), where a landslide rushed into an artificial lake which spilled over and caused a flood leading to almost 2000 fatalities. Hazards from the failure of landslide dams are often (not always) fairly manageable: most breaches occur in the first few days or weeks after the landslide event and the rapid construction of a spillway - though problematic - has solved some hazardous situations (e.g. in the case of Hattian landslide in 2005 in Pakistan). Older dams, like Usoi dam (Lake Sarez) in Tajikistan, are usually fairly stable, though landsildes into the lakes may create floodwaves overtopping and eventually weakening the dams. The analysis and the mitigation of glacial lake outburst flood (GLOF) hazard remains a challenge. A number of GLOFs resulting in fatalities and severe damage have occurred during the previous decades, particularly in the Himalayas and in the mountains of Central Asia (Pamir, Tien Shan). The source area is usually far away from the area of impact and events occur at very long intervals or as singularities, so that the population at risk is usually not prepared. Even though potentially hazardous lakes can be identified relatively easily with remote sensing and field work, modeling and predicting of GLOFs (and also

  19. List context effects in languages with opaque and transparent orthographies: A challenge for models of reading

    Directory of Open Access Journals (Sweden)

    Daniela eTraficante

    2014-09-01

    Full Text Available This paper offers a review of data which show that reading is a flexible and dynamic process and that readers can exert strategic control over it. Two main hypotheses on the control of reading processes have been suggested: the route de-emphasis hypothesis and the time-criterion hypothesis. According to the former, the presence of irregular words in the list might lead to an attenuation of the non-lexical process, while the presence of non-words could trigger a de-emphasis of the lexical route. An alternative account is proposed by the time-criterion hypothesis whereby the reader sets a flexible deadline to initiate the response. According to the latter view, it is the average pronunciation difficulty of the items in the block that modulates the time-criterion for response. However, it is worth noting that the list composition has been shown to exert different effects in transparent compared to opaque orthographies, as the consistency of spelling-sound correspondences can influence the processing costs of the non-lexical pathway. In transparent orthographies, the non-lexical route is not resource demanding and can successfully contribute to the pronunciation of regular words, thus its de-emphasis could not be as useful/necessary as in opaque orthographies. The complex patterns of results from the literature on list context effects are a challenge for computational models of reading which face the problem of simulating strategic control over reading processes. Different proposals suggest a modification of parameter setting in the non-lexical route or the implementation of a new module aimed at focusing attention on the output of the more convenient pathway. Simulation data and an assessment of the models’ fit to the behavioral results are presented and discussed to shed light on the role of the cognitive system when reading aloud.

  20. Intravenous Infusion of Bone Marrow–Derived Mesenchymal Stem Cells Reduces Erectile Dysfunction Following Cavernous Nerve Injury in Rats

    OpenAIRE

    Yohei Matsuda, MD; Masanori Sasaki, MD, PhD; Yuko Kataoka-Sasaki, MD, PhD; Akio Takayanagi, MD, PhD; Ko Kobayashi, MD, PhD; Shinichi Oka, MD, PhD; Masahito Nakazaki, MD, PhD; Naoya Masumori, MD, PhD; Jeffery D. Kocsis, PhD; Osamu Honmou, MD, PhD

    2018-01-01

    Introduction: Intravenous preload (delivered before cavernous nerve [CN] injury) of bone marrow–derived mesenchymal stem cells (MSCs) can prevent or decrease postoperative erectile dysfunction (J Sex Med 2015;12:1713–1721). In the present study, the potential therapeutic effects of intravenously administered MSCs on postoperative erectile dysfunction were evaluated in a rat model of CN injury. Methods: Male Sprague-Dawley rats were randomized into 2 groups after electric CN injury. Intrave...

  1. A tomographic approach to intravenous coronary arteriography

    International Nuclear Information System (INIS)

    Ritman, E.L.; Bove, A.A.

    1986-01-01

    Coronary artery anatomy can be visualized using high speed, volume scanning X-ray CT. A single scan during a bolus injection of contrast medium provides image data for display of all angles of view of the opacified coronary arterial tree. Due to the tomographic nature of volume image data the superposition of contrast filled cardiac chambers, such as would occur in the levophase of an intravenous injection of contrast agent, can be eliminated. Data are presented which support these statements. The Dynamic Spatial Reconstructor (DSR) was used to scan a life-like radiologic phantom of an adult human thorax in which the left atrial and ventricular chambers and the major epicardial coronary arteries were opacified so as to simulate the levophase of an intravenous injection of contrast agent. A catheter filled with diluted contrast agent and with regions of luminal narrowing (i.e. 'stenoses') was advanced along a tract equivalent to a right ventricular catheterization. Ease of visualization of the catheter 'stenoses' and the accuracy with which they can be measured are presented. (Auth.)

  2. Panlobular emphysema in young intravenous Ritalin abusers

    International Nuclear Information System (INIS)

    Schmidt, R.A.; Glenny, R.W.; Godwin, J.D.; Hampson, N.B.; Cantino, M.E.; Reichenbach, D.D.

    1991-01-01

    We studied a distinctive group of young intravenous Ritalin abusers with profound obstructive lung disease. Clinically, they seemed to have severe emphysema, but the pathologic basis of their symptoms had not been investigated previously. Seven patients have died and been autopsied: in four, the lungs were fixed, inflated, dried, and examined in detail radiologically, grossly, microscopically, and by electron probe X-ray microanalysis. All seven patients had severe panlobular (panacinar) emphysema that tended to be more severe in the lower lung zones and that was associated with microscopic talc granulomas. Vascular involvement by talc granulomas was variable, but significant interstitial fibrosis was not present. Five patients were tested for alpha-1-antitrypsin deficiency and found to be normal, as were six similar living patients. These findings indicate that some intravenous drug abusers develop emphysema that clinically, radiologically, and pathologically resembles that caused by alpha-1-antitrypsin deficiency but which must have a different pathogenesis. Talc from the Ritalin tablets may be important, but the mechanism remains to be elucidated

  3. The human experience with intravenous levodopa

    Directory of Open Access Journals (Sweden)

    Shan H Siddiqi

    2016-01-01

    Full Text Available Objective: To compile a comprehensive summary of published human experience with levodopa given intravenously, with a focus on information required by regulatory agencies.Background: While safe intravenous (IV use of levodopa has been documented for over 50 years, regulatory supervision for pharmaceuticals given by a route other than that approved by the U.S. Food and Drug Administration (FDA has become increasingly cautious. If delivering a drug by an alternate route raises the risk of adverse events, an investigational new drug (IND application is required, including a comprehensive review of toxicity data.Methods: Over 200 articles referring to IV levodopa were examined for details of administration, pharmacokinetics, benefit and side effects.Results: We identified 142 original reports describing IVLD use in humans, beginning with psychiatric research in 1959-1960 before the development of peripheral decarboxylase inhibitors. Over 2750 subjects have received IV levodopa, and reported outcomes include parkinsonian signs, sleep variables, hormone levels, hemodynamics, CSF amino acid composition, regional cerebral blood flow, cognition, perception and complex behavior. Mean pharmacokinetic variables were summarized for 49 healthy subjects and 190 with Parkinson’s disease. Side effects were those expected from clinical experience with oral levodopa and dopamine agonists. No articles reported deaths or induction of psychosis.Conclusion: Over 2750 patients have received IV levodopa with a safety profile comparable to that seen with oral administration.

  4. Intravenous Carbamazepine for Adults With Seizures.

    Science.gov (United States)

    Vickery, P Brittany; Tillery, Erika E; DeFalco, Alicia Potter

    2018-03-01

    To review the pharmacology, pharmacokinetics, efficacy, safety, dosage and administration, potential drug-drug interactions, and place in therapy of the intravenous (IV) formulation of carbamazepine (Carnexiv) for the treatment of seizures in adult patients. A comprehensive PubMed and EBSCOhost search (1945 to August 2017) was performed utilizing the keywords carbamazepine, Carnexiv, carbamazepine intravenous, IV carbamazepine, seizures, epilepsy, and seizure disorder. Additional data were obtained from literature review citations, manufacturer's product labeling, and Lundbeck website as well as Clinicaltrials.gov and governmental sources. All English-language trials evaluating IV carbamazepine were analyzed for this review. IV carbamazepine is FDA approved as temporary replacement therapy for treatment of adult seizures. Based on a phase I trial and pooled data from 2 open-label bioavailability studies comparing oral with IV dosing, there was no noted indication of loss of seizure control in patients switched to short-term replacement antiepileptic drug therapy with IV carbamazepine. The recommended dose of IV carbamazepine is 70% of the patient's oral dose, given every 6 hours via 30-minute infusions. The adverse effect profile of IV carbamazepine is similar to that of the oral formulation, with the exception of added infusion-site reactions. IV carbamazepine is a reasonable option for adults with generalized tonic-clonic or focal seizures, previously stabilized on oral carbamazepine, who are unable to tolerate oral medications for up to 7 days. Unknown acquisition cost and lack of availability in the United States limit its use currently.

  5. Adverse reactions to iotroxate at intravenous cholangiography

    International Nuclear Information System (INIS)

    Nilsson, U.

    1987-01-01

    The number and type of adverse reactions to meglumine iotroxate at intravenous infusion cholangiography, performed one day prior to elective cholecystectomy, were recorded in a prospective investigation of 196 asymptomatic, anicteric patients. One hundred ml (50 mg I/ml) of contrast medium was infused over a period of 30 minutes. Only 2 minor (1%) and no severe or fatal reactions were noted. A review of the literature on the use of iotroxate in 2492 patients, including those in the present investigation, revealed a complication rate of 3.5% (3.0% minor, 0.3% moderate and 0.2% severe reactions) at infusion of iotroxate (5.0-8.0 g I) over a period of 30 to 120 minutes. This compared favourably with the 5% complication rate (4% minor, 0.5% moderate and 0.5% severe reactions) at infusion of iodoxamate and the 9% complication rate (5% minor, 1% moderate and 3% severe reactions) at infusion of ioglycamide. Irrespective of the contrast agent used, the frequency of adverse reactions at infusion was found to be 3 times lower than when equal amounts (5.0-5.6 g I) of the same medium were injected. It is concluded that, at present, infusion of iotroxate in an amount which approximates to the transportation maximum of the liver is the least toxic way of performing intravenous cholangiography with an optimum filling of the bile ducts. (orig.)

  6. Intravenous dynamic nucleography of the brain

    International Nuclear Information System (INIS)

    Rosenthall, L.

    1972-01-01

    The advent of stationary imaging devices has created interest in studying cerebral blood flows and transits with diffusible and nondiffusible radioactive indicators. Much of this has disclosed interesting pathophysiology, but not necessarily of significant diagnostic import to include in routine patient workup. The conventional static brain scan is one of the more useful tests in the nuclear medicine armamentarium for uncovering and localizing intracranial disease. Unfortunately, it does not as a rule clearly distinguish cerebral vascular accidents, neoplasms, arteriovenous malformations, and so forth, which is important from the standpoint of patient management. Aside from clinical impressions a diagnosis is often based on the appearance of the radiocontrast angiogram, which is not always desirable because of the implicit hazards. Thus it is incumbent upon investigators to search for innocuous intravenous methods of identifying the various intracranial afflictions. Intravenous 99 /sup m/Tc-pertechnetate comparisons of brain hemisphere perfusion as a routine complement to static brain imaging are useful. Estimations of disparate radioactive transits are made qualitatively from serial 4 to 5 sec exposure scintiphotographs. (U.S.)

  7. Intravenous immunoglobulin therapy and systemic lupus erythematosus.

    Science.gov (United States)

    Zandman-Goddard, Gisele; Levy, Yair; Shoenfeld, Yehuda

    2005-12-01

    Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with diverse manifestations. We suggest that intravenous immunoglobulin (IVIg) therapy may be beneficial and safe for various manifestations in SLE. A structured literature search of articles published on the efficacy of IVIg in the treatment of SLE between 1983 and 2005 was conducted. We searched the terms "IVIg," "intravenous immunoglobulin," "lupus," "SLE," and "systemic lupus erythematosus." The various clinical manifestations of SLE that were reported to be successfully treated by IVIg in case reports include autoimmune hemolytic anemia, acquired factor VIII inhibitors, acquired von Willebrand disease, pure red cell aplasia, thrombocytopenia, pancytopenia, myelofibrosis, pneumonitis, pleural effusion, pericarditis, myocarditis, cardiogenic shock, nephritis, end-stage renal disease, encephalitis, neuropsychiatric lupus, psychosis, peripheral neuropathy, polyradiculoneuropathy, and vasculitis. The most extensive experience is with lupus nephritis. There are only a few case series of IVIg use in patients with SLE with various manifestations, in which the response rate to IVIg therapy ranged from 33 to 100%. We suggest that IVIg devoid of sucrose, at a dose of 2 g/kg over a 5-d period given uniformly and at a slow infusion rate in patients without an increased risk for thromboembolic events or renal failure, is a safe and beneficial adjunct therapy for cases of SLE that are resistant to or refuse conventional treatment. The duration of therapy is yet to be established. Controlled trials are warranted.

  8. Intravenous ferric carboxymaltose for anaemia in pregnancy.

    Science.gov (United States)

    Froessler, Bernd; Collingwood, Joshua; Hodyl, Nicolette A; Dekker, Gustaaf

    2014-03-25

    Iron deficiency is a common nutritional deficiency amongst women of childbearing age. Peri-partum iron deficiency anaemia (IDA) is associated with significant maternal, fetal and infant morbidity. Current options for treatment are limited: these include oral iron supplementation, which can be ineffective and poorly tolerated, and red blood cell transfusions, which carry an inherent risk and should be avoided. Ferric carboxymaltose is a new treatment option that may be better tolerated.The study was designed to assess the safety and efficacy of iron deficiency anaemia (IDA) correction with intravenous ferric carboxymaltose in pregnant women with mild, moderate and severe anaemia in the second and third trimester. Prospective observational study; 65 anaemic pregnant women received ferric carboxymaltose up to 15 mg/kg between 24 and 40 weeks of pregnancy (median 35 weeks gestational age, SD 3.6). Treatment effectiveness was assessed by repeat haemoglobin (Hb) measurements and patient report of well-being in the postpartum period. Safety was assessed by analysis of adverse drug reactions and fetal heart rate monitoring during the infusion. Intravenous ferric carboxymaltose infusion significantly increased Hb values (p anaemia in pregnancy.

  9. Transferring knowledge from observations and models to decision makers: an overview and challenges

    Science.gov (United States)

    Habib, Shahid; Nokra, Nada A.

    2004-02-01

    Over the last 25 years, a tremendous progress has been made in the Earth science space-based remote sensing observations, technologies and algorithms. Such advancements have improved the predictability by providing lead-time and accuracy of forecast in weather, climate, natural hazards, and natural resources. It has further reduced or bounded the overall uncertainties by partially improving our understanding of planet Earth as an integrated system that is governed by non-linear and chaotic behavior. Many countries such US, European Community, Japan, China and others have invested billions of dollars in developing and launching space-based assets in the low earth (LEO) and geostationary (GEO) orbits. However, the wealth of this scientific knowledge that has potential of extracting monumental socio-economic benefits from such large investments have been slow in reaching the public and decision makers. For instance, there are a number of areas such as energy forecasting, aviation safety, agricultural competitiveness, disaster management, homeland security, air quality and public health, which can directly take advantage. Nevertheless, we all live in a global economy that depends on access to the best available Earth Science information for all inhabitants of this planet. This paper surveys and examines a number such applications in terms of their architecture, maturity and economic applicability as they apply to the societal needs. A detailed analysis is also presented of various challenges and issues that pertain to a number of areas such as: (1) difficulties in making a speedy transition of data and information from observations and models to relevant Decision Support Systems (DSS) or tools, (2) data and models inter-operability issues, (3) limitations of spatial, spectral and temporal resolution,(4) communication limitations as dictated by the availability of image processing and data compression techniques. Additionally, the most critical element amongst all is

  10. Transferring Knowledge from Observations and Models to Decision Makers: An Overview and Challenges

    Science.gov (United States)

    Habib, Shahid; Nokra, Nada Abu

    2003-01-01

    Over the last 25 years, a tremendous progress has been made in the Earth science space-based remote sensing observations, technologies and algorithms. Such advancements have improved the predictability by providing lead-time and accuracy of forecast in weather, climate, natural hazards, and natural resources. It has further reduced or bounded the overall uncertainties by partially improving our understanding of planet Earth as an integrated system that is governed by non-linear and chaotic behavior. Many countries such US, European Community, Japan, China and others have invested billions of dollars in developing and launching space-based assets in the low earth (LEO) and geostationary (GEO) orbits. However, the wealth of this scientific knowledge that has potential of extracting monumental socio-economic benefits from such large investments have been slow in reaching to public and decision makers. For instance, there are a number of areas such as energy forecasting, aviation safety, agricultural competitiveness, disaster management, security, air quality and public health can directly take advantage. Nevertheless, we all live in a global economy that depends on access to the best available Earth Science information for all inhabitants of this planet. This paper surveys and examines a number such applications in terms of their architecture, maturity and economic applicability as they apply to the societal needs. A detailed analysis is also presented of various challenges and issues that pertain to a number of areas such as: (1) difficulties in making a speedy transition of data and information from observations and models to relevant Decision Support Systems (DSS) or tools, (2) data and models inter-operability issues, (3) limitations of spatial, spectral and temporal resolution, (4) communication limitations as dictated by the availability of image processing and data compression techniques. Additionally, the most critical element amongst all is the organizational

  11. Wind vs Water in Hurricanes: The Challenge of Multi-peril Hazard Modeling

    Science.gov (United States)

    Powell, M. D.

    2017-12-01

    operational solution to collect wind and water level measurements, and to conduct observation based modeling of wind and water impacts. My presentation will discuss some of the challenges to wind and water hazard monitoring and modeling.

  12. Ultrasonography-guided peripheral intravenous access versus traditional approaches in patients with difficult intravenous access.

    Science.gov (United States)

    Costantino, Thomas G; Parikh, Aman K; Satz, Wayne A; Fojtik, John P

    2005-11-01

    We assess the success rate of emergency physicians in placing peripheral intravenous catheters in difficult-access patients who were unsuccessfully cannulated by emergency nurses. A technique using real-time ultrasonographic guidance by 2 physicians was compared with traditional approaches using palpation and landmark guidance. This was a prospective, systematically allocated study of all patients requiring intravenous access who presented to 2 university hospitals between October 2003 and March 2004. Inclusion criterion was the inability of any available nurse to obtain intravenous access after at least 3 attempts on a subgroup of patients who had a history of difficult intravenous access because of obesity, history of intravenous drug abuse, or chronic medical problems. Exclusion criterion was the need for central venous access. Patients presenting on odd days were allocated to the ultrasonographic-guided group, and those presenting on even days were allocated to the traditional-approach group. Endpoints were successful cannulation, number of sticks, time, and patient satisfaction. Sixty patients were enrolled, 39 on odd days and 21 on even days. Success rate was greater for the ultrasonographic group (97%) versus control (33%), difference in proportions of 64% (95% confidence interval [CI] 39% to 71%). The ultrasonographic group required less overall time (13 minutes versus 30 minutes, for a difference of 17 [95% CI 0.8 to 25.6]), less time to successful cannulation from first percutaneous puncture (4 minutes versus 15 minutes, for a difference of 11 [95% CI 8.2 to 19.4]), and fewer percutaneous punctures (1.7 versus 3.7, for a difference of 2.0 [95% CI 1.27 to 2.82]) and had greater patient satisfaction (8.7 versus 5.7, for a difference of 3.0 [95% CI 1.82 to 4.29]) than the traditional landmark approach. Ultrasonographic-guided peripheral intravenous access is more successful than traditional "blind" techniques, requires less time, decreases the number of

  13. Safety and pharmacokinetics of intravenous levetiracetam infusion as add-on in status epilepticus

    NARCIS (Netherlands)

    Uges, Joris W F; van Huizen, Marc D; Engelsman, Jeroen; Wilms, Erik B; Touw, Daniel J; Peeters, Els; Vecht, Charles J

    PURPOSE: To evaluate the feasibility and safety of intravenous (iv) levetiracetam (LEV) added to the standard therapeutic regimen in adults with status epilepticus (SE), and as secondary objective to assess a population pharmacokinetic (PK) model for ivLEV in patients with SE. METHODS: In 12 adults

  14. Administration costs of intravenous biologic drugs for rheumatoid arthritis

    OpenAIRE

    Soini, Erkki J; Leussu, Miina; Hallinen, Taru

    2013-01-01

    Background Cost-effectiveness studies explicitly reporting infusion times, drug-specific administration costs for infusions or real-payer intravenous drug cost are few in number. Yet, administration costs for infusions are needed in the health economic evaluations assessing intravenously-administered drugs. Objectives To estimate the drug-specific administration and total cost of biologic intravenous rheumatoid arthritis (RA) drugs in the adult population and to compare the obtained costs wit...

  15. Why employees with higher challenging appraisals style are more affectively engaged at work? The role of challenging stressors: a moderated mediation model.

    Science.gov (United States)

    Lin, Shin-Huei; Wu, Chia-Huei; Chen, Mei-Yen; Chen, Lung Hung

    2014-10-01

    Challenging stressors have been positively linked to various work outcomes. However, the role of individual differences in stress appraisal in shaping the function of challenging stressors and work outcomes has been rarely discussed. Drawing on the individual differences perspective, the authors propose that employees higher in challenge appraisal are more likely to have challenging stressors and are more responsive to such stressors to have a higher positive affect at work. Results obtained from 117 employees supported the hypotheses. The results indicated that challenge appraisal is positively related to challenging stressors. In addition, challenging stressors has a positive association with positive affect at work when challenge appraisal is high but has a null association when challenge appraisal is low. The findings suggest that challenging stressors does not necessarily bring positive work outcomes as suggested in past studies and highlight the importance of considering dispositional tendency in stress appraisal when looking into the function of challenging stressors and work outcomes. © 2014 International Union of Psychological Science.

  16. Optimizing the use of intravenous therapy in internal medicine.

    Science.gov (United States)

    Champion, Karine; Mouly, Stéphane; Lloret-Linares, Celia; Lopes, Amanda; Vicaut, Eric; Bergmann, Jean-François

    2013-10-01

    We aimed to evaluate the impact of physicians' educational programs in the reduction of inappropriate intravenous lines in internal medicine. Fifty-six French internal medicine units were enrolled in a nationwide, prospective, blinded, randomized controlled trial. Forms describing the patients with an intravenous line and internal medicine department characteristics were filled out on 2 separate days in January and April 2007. Following the first visit, all units were randomly assigned to either a specific education program on the appropriate indications of an intravenous line, during February and March 2007, or no training (control group). The Investigators' Committee then blindly evaluated the clinical relevance of the intravenous line according to pre-established criteria. The primary outcome was the percentage of inappropriate intravenous lines. During January 2007, intravenous lines were used in 475 (24.9%) of the 1910 hospitalized patients. Of these, 80 (16.8%) were considered inappropriate. In April 2007, 416 (22.8%) of the 1823 hospitalized patients received an intravenous line, which was considered in 10.2% (21/205) of patients managed by trained physicians, versus 16.6% (35/211) of patients in the control group (relative difference 39%; 95% confidence interval, -0.6-13.3; P = .05). Reduced intravenous administration of fluids, antibiotics, and analgesics accounted for the observed decrease. The use of a simple education program reduced the rate of inappropriate intravenous lines by almost 40% in an internal medicine setting (NCT01633307). Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Effects of intravenous diclofenac on postoperative sore throat in ...

    African Journals Online (AJOL)

    Effects of intravenous diclofenac on postoperative sore throat in patients undergoing laparoscopic surgery at Aga Khan University Hospital, Nairobi: A prospective, randomized, double blind controlled trial.

  18. Low-dose intravenous lidocaine as treatment for proctalgia fugax.

    Science.gov (United States)

    Peleg, Roni; Shvartzman, Pesach

    2002-01-01

    Proctalgia fugax is characterized by a sudden internal anal sphincter and anorectic ring attack of pain of a short duration. Description of the influence of intravenous lidocaine treatment for proctalgia fugax. A 28-year-old patient suffering of proctalgia fugax for 8 months. Conventional treatment efforts did not improve his condition. A single dose of an intravenous lidocaine infusion completely stopped his pain attacks. Based on the experience reported in this case and the potential benefit of this treatment for proctalgia fugax, controlled studies comparing intravenous lidocaine with placebo should be conducted to confirm the observation and to provide a more concrete basis for the use of intravenous lidocaine for this indication.

  19. Challenge problem and milestones for : Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC).

    Energy Technology Data Exchange (ETDEWEB)

    Freeze, Geoffrey A.; Wang, Yifeng; Howard, Robert; McNeish, Jerry A.; Schultz, Peter Andrew; Arguello, Jose Guadalupe, Jr.

    2010-09-01

    This report describes the specification of a challenge problem and associated challenge milestones for the Waste Integrated Performance and Safety Codes (IPSC) supporting the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The NEAMS challenge problems are designed to demonstrate proof of concept and progress towards IPSC goals. The goal of the Waste IPSC is to develop an integrated suite of modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with robust verification, validation, and software quality requirements. To demonstrate proof of concept and progress towards these goals and requirements, a Waste IPSC challenge problem is specified that includes coupled thermal-hydrologic-chemical-mechanical (THCM) processes that describe (1) the degradation of a borosilicate glass waste form and the corresponding mobilization of radionuclides (i.e., the processes that produce the radionuclide source term), (2) the associated near-field physical and chemical environment for waste emplacement within a salt formation, and (3) radionuclide transport in the near field (i.e., through the engineered components - waste form, waste package, and backfill - and the immediately adjacent salt). The initial details of a set of challenge milestones that collectively comprise the full challenge problem are also specified.

  20. Challenge problem and milestones for: Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC)

    International Nuclear Information System (INIS)

    Freeze, Geoffrey A.; Wang, Yifeng; Howard, Robert; McNeish, Jerry A.; Schultz, Peter Andrew; Arguello, Jose Guadalupe Jr.

    2010-01-01

    This report describes the specification of a challenge problem and associated challenge milestones for the Waste Integrated Performance and Safety Codes (IPSC) supporting the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The NEAMS challenge problems are designed to demonstrate proof of concept and progress towards IPSC goals. The goal of the Waste IPSC is to develop an integrated suite of modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with robust verification, validation, and software quality requirements. To demonstrate proof of concept and progress towards these goals and requirements, a Waste IPSC challenge problem is specified that includes coupled thermal-hydrologic-chemical-mechanical (THCM) processes that describe (1) the degradation of a borosilicate glass waste form and the corresponding mobilization of radionuclides (i.e., the processes that produce the radionuclide source term), (2) the associated near-field physical and chemical environment for waste emplacement within a salt formation, and (3) radionuclide transport in the near field (i.e., through the engineered components - waste form, waste package, and backfill - and the immediately adjacent salt). The initial details of a set of challenge milestones that collectively comprise the full challenge problem are also specified.

  1. Short-lasting systemic and regional benefits of early crystalloid infusion after intravenous inoculation of dogs with live Escherichia coli

    Directory of Open Access Journals (Sweden)

    Garrido A.G.

    2005-01-01

    Full Text Available We investigated the systemic and regional hemodynamic effects of early crystalloid infusion in an experimental model of septic shock induced by intravenous inoculation with live Escherichia coli. Anesthetized dogs received an intravenous infusion of 1.2 x 10(10 cfu/kg live E. coli in 30 min. After 30 min of observation, they were randomized to controls (no fluids; N = 7, or fluid resuscitation with lactated Ringer's solution, 16 ml/kg (N = 7 or 32 ml/kg (N = 7 over 30 min and followed for 120 min. Cardiac index, portal blood flow, mean arterial pressure, systemic and regional oxygen-derived variables, blood lactate, and gastric PCO2 were assessed. Rapid and progressive cardiovascular deterioration with reduction in cardiac output, mean arterial pressure and portal blood flow (~50, ~25 and ~70%, respectively was induced by the live bacteria challenge. Systemic and regional territories showed significant increases in oxygen extraction and in lactate levels. Significant increases in venous-arterial (~9.6 mmHg, portal-arterial (~12.1 mmHg and gastric mucosal-arterial (~18.4 mmHg PCO2 gradients were also observed. Early fluid replacement, especially with 32 ml/kg volumes of crystalloids, promoted only partial and transient benefits such as increases of ~76% in cardiac index, of ~50% in portal vein blood flow and decreases in venous-arterial, portal-arterial, gastric mucosal-arterial PCO2 gradients (7.2 ± 1.0, 7.2 ± 1.3 and 9.7 ± 2.5 mmHg, respectively. The fluid infusion promoted only modest and transient benefits, unable to restore the systemic and regional perfusional and metabolic changes in this hypodynamic septic shock model.

  2. Solar urticaria successfully treated with intravenous immunoglobulin.

    LENUS (Irish Health Repository)

    Hughes, R

    2012-02-01

    Idiopathic solar urticaria (SU) is a rare, debilitating photodermatosis, which may be difficult to treat. First-line treatment with antihistamines is effective in mild cases, but remission after phototherapeutic induction of tolerance is often short-lived. Other treatment options include plasma exchange, photopheresis and cyclosporin. We present two cases of severe, idiopathic SU, which were resistant to conventional treatment. Both patients achieved remission after administration of intravenous immunoglobulin (IVIg) and have remained in remission at 13 months and 4 years, respectively. There are only two case reports of successful treatment of solar urticaria with IVIg. In our experience IVIg given at a total dose of 2 g\\/kg over several 5-day courses about a month apart is an effective treatment option for severe idiopathic SU. It is also generally safe, even if certainly subject to significant theoretical risks, such as induction of viral infection or anaphylaxis.

  3. Anaphylaxis after intravenous infusion of dexketoprofen trometamol

    Directory of Open Access Journals (Sweden)

    Sertac Guler

    2016-09-01

    Full Text Available Dexketoprofen trometamol (DT, a nonsteroidal anti-inflammatory drug, is a highly water-soluble salt and active enantiomer of rac-ketoprofen. Its parenteral form is commonly used for acute pain management in emergency departments of our country. Side effects such as diarrhea, indigestion, nausea, stomach pain, and vomiting may be seen after the use of DT. Anaphylactic shock (AS secondary to infusion of DT is very rare and, to our knowledge, it is the first case report describing this side effect. This case report was presented to emphasize that AS may be seen after the use of DT. Keywords: Anaphylactic shock, Dexketoprofen trometamol, Intravenous infusion (MeSH database

  4. Switching between intravenous and subcutaneous trastuzumab

    DEFF Research Database (Denmark)

    Gligorov, Joseph; Curigliano, Giuseppe; Müller, Volkmar

    2017-01-01

    AIM: To assess the safety and tolerability of switching between subcutaneous (SC) and intravenous (IV) trastuzumab in the PrefHer study (NCT01401166). PATIENTS AND METHODS: Patients with HER2-positive early breast cancer completed (neo)adjuvant chemotherapy and were randomised to receive four...... cycles of SC trastuzumab, via single-use injection device (SID; Cohort 1) or hand-held syringe (Cohort 2), followed by four cycles of IV, or vice versa (the crossover period presented here) as part of their 18 standard cycles of adjuvant trastuzumab treatment. Adverse events (AEs) were reported using....... Rates of clinically important events, including grade ≥3 AEs, serious AEs, AEs leading to study drug discontinuation and cardiac AEs, were low and similar between treatment arms (trastuzumab were observed. CONCLUSIONS: PrefHer revealed...

  5. Intravenous immunoglobulin and Alzheimer's disease immunotherapy.

    Science.gov (United States)

    Solomon, Beka

    2007-02-01

    Amyloid-beta peptide (Abeta) contributes to the acute progression of Alzheimer's disease (AD) and has become the main target for therapeutics. Active immunization with Abeta in individuals with AD has been efficacious; however, some patients developed side effects, possibly related to an autoimmune response. Evidence that intravenous immunoglobulin (IVIg), an FDA-approved purified immunoglobulin fraction from normal human donor blood, shows promise of passive immunotherapy for AD is reviewed. Investigations into the molecular effects of IVIg on Abeta clearance, using the BV-2 cellular microglia line, demonstrate that IVIg dissolves Abeta fibrils in vitro, increases cellular tolerance to Abeta, enhances microglial migration toward Abeta deposits, and mediates phagocytosis of Abeta. Preliminary clinical results indicate that IVIg, which contains natural antibodies against the Abeta, warrants further study into its potential to deliver a controlled immune attack on the peptide, avoiding the immune toxicities that have had a negative impact on the first clinical trials of vaccine against Abeta.

  6. Intravenous urography in children and youth

    International Nuclear Information System (INIS)

    Pedersen, H.K.; Gudmundsen, T.E.; Oestensen, H.; Pape, J.F.

    1987-01-01

    This report derives from Tromsoe in northern Norway. In a retrospective study of the indications for intravenous urography (IU) and the findings at IU in 740 patients (451 girls and 289 boys) aged 0-19 years, we found that urinary tract infections accounted for 69.4% of the IU in females and 30.1% of the IU in males, most often seen in the youngest patients. The pathological findings most frequently seen were anomalies (17 females and 10 males) and urinary tract obstruction (3 females and 15 males). The present study indicates the following: first, that the yield of IU in the primary investigation of children and youth suffering from enuresis and non-specific abdominal disturbancies is small; and second, that the use of IU in children and youth with urinary tract infection and haematuria should be questioned and reconsidered. (orig.)

  7. 1-3-7 minute intravenous urography

    International Nuclear Information System (INIS)

    Bahk, Yong Whee; Yoon, Sei Chul; Lee, Myung Hee

    1980-01-01

    Intravenous urography (IVU) as it is used widely today was probably started in early 1950's after the introduction of triiodobenzoic acid compounds as contrast media. This long cherished traditional method consists of taking radiograms at 5, 15 and 25 minutes after the injection of contrast medium. There are a few modifications of this standard urographic examination such as five minute IVU (Woodruff, 1959), minute-sequence pyelogram (Maxwell et al., 1964), drip infusion pyelography (Schencker, 1964) and nephrotomography (Evans et al., 1955). The present study has been undertaken to test if the conventional standard IVU can be more rapidly performed without losing essential informational contents of urograms. In this new clinical trial, urograms were taken at the end of 1, 3 and 7 minutes instead of 5, 15 and 25 minutes after the intravenous injection of contrast medium. We injected 40 ml of meglumine diatrizoate solution within 30 seconds using an 18G iv needle. (The amount of injected contrast medium has been reduced recently to ordinary single dose of 20 ml for subjects weighing less than 8 kg). Upon viewing the 7 minute film in front of an automatic processor, the examination was terminated after obtaining an upright view unless any further radiogram was indicated. As shown in Tables and Figures, our new 1-3-7 minute method has been proven to provide us with as much essential and useful information as conventional 5-15-25 minute urography. Thus, we were able to finish one examination within 10 minutes without losing any necessary diagnostic information. In some of patients with obstructive uropathy such as stone the examination was extended as long as it was desired. Side reactions were occasional nausea, flushing and rare mild vomiting which never prevented the examination

  8. Simulating the impacts of disturbances on forest carbon cycling in North America: Processes, data, models, and challenges

    Science.gov (United States)

    Liu, Shuguang; Bond-Lamberty, Ben; Hicke, Jeffrey A.; Vargas, Rodrigo; Zhao, Shuqing; Chen, Jing; Edburg, Steven L.; Hu, Yueming; Liu, Jinxun; McGuire, A. David; Xiao, Jingfeng; Keane, Robert; Yuan, Wenping; Tang, Jianwu; Luo, Yiqi; Potter, Christopher; Oeding, Jennifer

    2011-01-01

    Forest disturbances greatly alter the carbon cycle at various spatial and temporal scales. It is critical to understand disturbance regimes and their impacts to better quantify regional and global carbon dynamics. This review of the status and major challenges in representing the impacts of disturbances in modeling the carbon dynamics across North America revealed some major advances and challenges. First, significant advances have been made in representation, scaling, and characterization of disturbances that should be included in regional modeling efforts. Second, there is a need to develop effective and comprehensive process‐based procedures and algorithms to quantify the immediate and long‐term impacts of disturbances on ecosystem succession, soils, microclimate, and cycles of carbon, water, and nutrients. Third, our capability to simulate the occurrences and severity of disturbances is very limited. Fourth, scaling issues have rarely been addressed in continental scale model applications. It is not fully understood which finer scale processes and properties need to be scaled to coarser spatial and temporal scales. Fifth, there are inadequate databases on disturbances at the continental scale to support the quantification of their effects on the carbon balance in North America. Finally, procedures are needed to quantify the uncertainty of model inputs, model parameters, and model structures, and thus to estimate their impacts on overall model uncertainty. Working together, the scientific community interested in disturbance and its impacts can identify the most uncertain issues surrounding the role of disturbance in the North American carbon budget and develop working hypotheses to reduce the uncertainty

  9. Challenges Pre-Service Teachers Face When Implementing a 5E Inquiry Model of Instruction

    Science.gov (United States)

    Enugu, Ramya; Hokayem, Hayat

    2017-01-01

    This study examined the challenges that pre-service teachers faced when implementing inquiry and their perspective on how to overcome them. The data sample was 55 pre-service teachers (PSTs) enrolled into two sections of a science methods course in a private university in North Texas. The data sources consisted of inquiry-based lesson plans, PST…

  10. The South African Engineering Education Model with a European Perspective: History, Analogies, Transformations and Challenges

    Science.gov (United States)

    Kloot, Bruce; Rouvrais, Siegfried

    2017-01-01

    South Africa, with its national cultural diversity and post-apartheid challenges and commitments, finds echoes in the European context, especially considering the imperatives of openness and non-discrimination in higher education. With an historical tradition of excellence in engineering education, the emphasis on supporting educationally…

  11. Motivation, Challenges, Support (MCS) Cycle Model for the Development of PBL Tutors

    Science.gov (United States)

    Constantinou, Costas S.; Nicolaou, Stella A.

    2018-01-01

    Problem-Based Learning (PBL) is well known for enhancing students' problem solving skills and teamwork, while the role of PBL tutors is to facilitate discussion rather than teach. This study used four focus groups to explore PBL tutors' motivation, challenges and support mechanisms, and the relationship between these. The study found that there…

  12. From California dreaming to California data: Challenging historic models for landfill CH4 emissions

    Science.gov (United States)

    Improved quantification of diverse CH4 sources at the urban scale is needed to guide local greenhouse gas (GHG) mitigation strategies in the Anthropocene. Herein, we focus on landfill CH4 emissions in California, challenging the current IPCC methodology which focuses on a climate dependency for land...

  13. From Teacher to Manager: Expectations and Challenge in the Further Education Sector. A Relationship Model

    Science.gov (United States)

    Corbett, Stephen

    2017-01-01

    In a turbulent working environment with varying expectations and challenges is it fair to expect further education teachers and managers to maintain and improve standards? This article highlights that with the incorporation of colleges began a series of initiatives to professionalise the FE sector. This coupled with pressures for those who work…

  14. Modeling and analysis for big data challenges in nano-imaging

    NARCIS (Netherlands)

    Grollios, T.

    2012-01-01

    Very large data sets, often being referred as Big Data, that are hard to collect, store, process and visualize using traditional computational methods are bringing challenges in various domains of the technology world. The resent advances in electron microscopy that enable the collection of large

  15. Confronting the STEM Challenge: A New Modeling Tool for U.S. Education Policymakers

    Science.gov (United States)

    Business-Higher Education Forum (NJ1), 2010

    2010-01-01

    The Business-Higher Education Forum (BHEF) is an organization of Fortune 500 chief executive officers (CEOs,) prominent college and university presidents, and foundation leaders working to advance innovative solutions to the nation's education challenges in order to enhance U.S. competitiveness. This paper presents questions and answers about the…

  16. A systematic review and checklist presenting the main challenges for health economic modeling in personalized medicine : towards implementing patient-level models

    NARCIS (Netherlands)

    Degeling, Koen; Koffijberg, Hendrik; IJzerman, Maarten Joost

    2017-01-01

    Introduction: The ongoing development of genomic medicine and the use of molecular and imaging markers in personalized medicine (PM) has arguably challenged the field of health economic modeling (HEM). This study aims to provide detailed insights into the current status of HEM in PM, in order to

  17. Breast abscess after intravenous methamphetamine injection into the breast.

    Science.gov (United States)

    Kistler, Amanda; Ajkay, Nicolas

    2018-05-01

    Intravenous drug use is a problem plaguing our society. We present a case of a young female who injected methamphetamine into her mammary vein, resulting in the formation of a breast abscess. This case demonstrates a rare but dangerous complication of intravenous drug use and a possible differential diagnosis in a patient presenting with a breast abscess. © 2017 Wiley Periodicals, Inc.

  18. Hydrothorax, hydromediastinum and pericardial effusion: a complication of intravenous alimentation.

    Science.gov (United States)

    Damtew, B; Lewandowski, B

    1984-01-01

    Complications secondary to intravenous alimentation are rare but potentially lethal. Massive bilateral pleural effusions and a pericardial effusion developed in a patient receiving prolonged intravenous alimentation. Severe respiratory distress and renal failure ensued. He recovered with appropriate treatment. Images Fig. 1 Fig. 2 Fig. 3 PMID:6428731

  19. Microbiological quality of some brands of intravenous fluids ...

    African Journals Online (AJOL)

    Microbiological quality of some brands of intravenous fluids produced by some pharmaceutical companies in Nigeria was investigated. Membrane filtration method was used for concentration of contaminating organisms in the intravenous fluids. Thioglycollate medium, Tryptone Soya broth, Brilliant Green Agar ...

  20. Cost-minimization of mabthera intravenous versus subcutaneous administration

    NARCIS (Netherlands)

    Bax, P.; Postma, M.J.

    2013-01-01

    Objectives: To identify and compare all costs related to preparing and administrating MabThera for the intravenous and subcutaneous formulations in Dutch hematological patients. The a priori notion is that the costs of subcutaneous MabThera injections are lower compared to intravenous infusion due

  1. Development of a vaccine-challenge model for avian metapneumovirus subtype C in turkeys.

    Science.gov (United States)

    Velayudhan, Binu T; Noll, Sally L; Thachil, Anil J; Shaw, Daniel P; Goyal, Sagar M; Halvorson, David A; Nagaraja, Kakambi V

    2007-02-26

    The objective of this study was to evaluate different preparations of avian metapneumovirus (aMPV) subtype C as vaccine challenge in turkeys. Two aMPV isolates and their respective nasal turbinate homogenates after propagation in turkeys were used in the study. Significantly higher clinical sign scores were recorded in birds inoculated with 20 or 2% turbinate homogenate of recent isolate. Birds in the above groups showed more pronounced histopathological lesions, and a higher percentage of birds showed viral RNA and antigen in tissues. The data demonstrated that nasal turbinate homogenate of recent isolate produced severe clinical signs and lesions in turkeys and could be an ideal candidate for vaccine-challenge studies.

  2. Pharmacokinetics and repolarization effects of intravenous and transdermal granisetron.

    Science.gov (United States)

    Mason, Jay W; Selness, Daniel S; Moon, Thomas E; O'Mahony, Bridget; Donachie, Peter; Howell, Julian

    2012-05-15

    The need for greater clarity about the effects of 5-HT(3) receptor antagonists on cardiac repolarization is apparent in the changing product labeling across this therapeutic class. This study assessed the repolarization effects of granisetron, a 5-HT(3) receptor antagonist antiemetic, administered intravenously and by a granisetron transdermal system (GTDS). In a parallel four-arm study, healthy subjects were randomized to receive intravenous granisetron, GTDS, placebo, or oral moxifloxacin (active control). The primary endpoint was difference in change from baseline in mean Fridericia-corrected QT interval (QTcF) between GTDS and placebo (ddQTcF) on days 3 and 5. A total of 240 subjects were enrolled, 60 in each group. Adequate sensitivity for detection of QTc change was shown by a 5.75 ms lower bound of the 90% confidence interval (CI) for moxifloxacin versus placebo at 2 hours postdose on day 3. Day 3 ddQTcF values varied between 0.2 and 1.9 ms for GTDS (maximum upper bound of 90% CI, 6.88 ms), between -1.2 and 1.6 ms for i.v. granisetron (maximum upper bound of 90% CI, 5.86 ms), and between -3.4 and 4.7 ms for moxifloxacin (maximum upper bound of 90% CI, 13.45 ms). Day 5 findings were similar. Pharmacokinetic-ddQTcF modeling showed a minimally positive slope of 0.157 ms/(ng/mL), but a very low correlation (r = 0.090). GTDS was not associated with statistically or clinically significant effects on QTcF or other electrocardiographic variables. This study provides useful clarification on the effect of granisetron delivered by GTDS on cardiac repolarization. ©2012 AACR.

  3. SaaS Model, Virtualization and Information Safety - Challenge for Online Business

    OpenAIRE

    Ioana Lupasc; Gabriela Gheorghe

    2016-01-01

    The advantages of new information technologies are present in all fields, while disadvantages, weaknesses represent a relatively recent topic of study. Security issues currently facing online business is new concerns for European legislative environment and new challenges of finding methods of securing technology solution providers offered information. As for Schengen terrorist threats represent a threat to the proper functioning of the European Economic Area also the online business cyber ...

  4. SaaS Model, Virtualization and Information Safety - Challenge for Online Business

    Directory of Open Access Journals (Sweden)

    Ioana Lupasc

    2016-07-01

    Full Text Available The advantages of new information technologies are present in all fields, while disadvantages, weaknesses represent a relatively recent topic of study. Security issues currently facing online business is new concerns for European legislative environment and new challenges of finding methods of securing technology solution providers offered information. As for Schengen terrorist threats represent a threat to the proper functioning of the European Economic Area also the online business cyber threats have the effect of impeding and even huge losses.

  5. From California dreaming to California data: Challenging historic models for landfill CH4 emissions

    OpenAIRE

    Spokas, Kurt; Bogner, Jean; Corcoran, Meg; Walker, Scott

    2015-01-01

    Abstract Improved quantification of diverse CH4 sources at the urban scale is needed to guide local GHG mitigation strategies in the Anthropocene. Herein, we focus on landfill CH4 emissions in California, challenging the current IPCC methodology which focuses on a climate dependency for landfill CH4 generation (methanogenesis), but does not explicitly consider climate or soil dependencies for emissions. Relying on a comprehensive California landfill database, a field-validated process-based m...

  6. Lost in Translation: The Challenge of Exporting Models of Civil Military Relations

    Science.gov (United States)

    2012-03-01

    society.”27 As Williams has noted, traditional mili- tary culture is confronted by a number of challenges such as cultural relativism and the...imposition of nonmilitary, social, ethical , and political criteria of evaluation on the mili- tary.28 It is these postmodern militaries, and the...members see themselves and what constitutes good governance, ethical behaviour and funda- mental courage.”45 In a study of leadership mythol- ogy in

  7. Modeling and optimization for proton exchange membrane fuel cell stack using aging and challenging P systems based optimization algorithm

    International Nuclear Information System (INIS)

    Yang, Shipin; Chellali, Ryad; Lu, Xiaohua; Li, Lijuan; Bo, Cuimei

    2016-01-01

    Accurate models of PEM (proton exchange membrane) fuel cells are of great significance for the analysis and the control for power generation. We present a new semi-empirical model to predict the voltage outputs of PEM fuel cell stacks. We also introduce a new estimation method, called AC-POA (aging and challenging P systems based optimization algorithm) allowing deriving the parameters of the semi-empirical model. In our model, the cathode inlet pressure is selected as an additional factor to modify the expression of concentration over-voltage V con for traditional Amphlett's PEM fuel cell model. In AC-POA, the aging-mechanism inspired object updating rule is merged in existing P system. We validate through experiments the effectiveness of AC-POA and the fitting accuracy of our model. Modeling comparison results show that the predictions of our model are the best in terms of fitting to actual sample data. - Highlights: • Presented a p c -based modificatory semi-empirical model for PEMFC stack. • Introduced a new aging inspired improved parameter estimation algorithm, AC-POA. • Validated the effectiveness of the AC-POA and the new model. • Remodeled the practical PEM fuel cell system.

  8. Highest Plasma Phenylalanine Levels in (Very Premature Infants on Intravenous Feeding; A Need for Concern.

    Directory of Open Access Journals (Sweden)

    Ernesto Cortés-Castell

    Full Text Available To analyse the association in newborns between blood levels of phenylalanine and feeding method and gestational age.This observational, cross-sectional study included a sample of 11,829 infants between 2008 and 2013 in a Spanish region. Data were recorded on phenylalanine values, feeding method [breast, formula, mixed (breast plus formula, or partial or fully intravenous feeding], gestational age in weeks (<32, 32-37, ≥37, gender and days since birth at the moment of blood collection. Outcomes were [phenylalanine] and [phenylalanine] ≥95th percentile. Associations were analysed using multivariate models [linear (means difference and logistic regression (adjusted odds ratios].Higher phenylalanine values were associated with lower gestational age (p<0.001 and with intravenous feeding (p<0.001.The degree of prematurity and intravenous feeding influenced the plasma concentration of phenylalanine in the newborn. Caution should be taken in [phenylalanine] for newborns with intravenous feeding, monitoring them carefully. Very preterm infants given the recommended amount of amino acids should also be strictly monitored. These findings should be taken into consideration and call for adapting the amounts to the needs of the infant.

  9. A New Modeling Approach for Future Challenges in Process and Product Design

    DEFF Research Database (Denmark)

    Eden, Mario Richard; Jørgensen, Sten Bay; Gani, Rafiqul

    2003-01-01

    In this paper, a new technique for model reduction that is based on rearranging a part of the model representing the constitutive equations is presented. The rearrangement of the constitutive equations leads to the definition of a new set of pseudo-intensive variables, where the component...... compositions are replaced by reduction parameters in the process model. Since the number of components dominates the size of the traditional model equations, a significant reduction of the model size is obtained through this new technique. Some interesting properties of this new technique is that the model...... reduction does not introduce any approximations to the model, it does not change the physical location of the process variables and it provides a, visualization of the process and operation that otherwise would not be possible. Furthermore by employing the recently introduced principle of reverse problem...

  10. A New Modeling Approach for Future Challenges in Process and Product Design

    DEFF Research Database (Denmark)

    In this paper, a new technique for model reduction that is based on rearranging a part of the model representing the constitutive equations is presented. The rearrangement of the constitutive equations leads to the definition of a new set of pseudo-intensive variables, where the component...... compositions are replaced by reduction parameters in the process model. Since the number of components dominates the size of the traditional model equations, a significant reduction of the model size is obtained through this new technique. Some interesting properties of this new technique is that the model...... reduction does not introduce any approximations to the model, it does not change the physical location of the process variables and it provides a visualization of the process and operation that otherwise would not be possible. Furthermore by employing the recently introduced principle of reverse problem...

  11. Towards Organs on Demand: Breakthroughs and Challenges in Models of Organogenesis.

    Science.gov (United States)

    Francipane, Maria Giovanna; Lagasse, Eric

    2016-09-01

    In recent years, functional three-dimensional (3D) tissue generation in vitro has been significantly advanced by tissue-engineering methods, achieving better reproduction of complex native organs compared to conventional culture systems. This review will discuss traditional 3D cell culture techniques as well as newly developed technology platforms. These recent techniques provide new possibilities in the creation of human body parts and provide more accurate predictions of tissue response to drug and chemical challenges. Given the rapid advancement in the human induced pluripotent stem cell (iPSC) field, these platforms also hold great promise in the development of patient-specific, transplantable tissues and organs on demand.

  12. Animal models of prenatal immune challenge and their contribution to the study of schizophrenia: a systematic review

    Directory of Open Access Journals (Sweden)

    D.S. Macêdo

    2012-03-01

    Full Text Available Prenatal immune challenge (PIC in pregnant rodents produces offspring with abnormalities in behavior, histology, and gene expression that are reminiscent of schizophrenia and autism. Based on this, the goal of this article was to review the main contributions of PIC models, especially the one using the viral-mimetic particle polyriboinosinic-polyribocytidylic acid (poly-I:C, to the understanding of the etiology, biological basis and treatment of schizophrenia. This systematic review consisted of a search of available web databases (PubMed, SciELO, LILACS, PsycINFO, and ISI Web of Knowledge for original studies published in the last 10 years (May 2001 to October 2011 concerning animal models of PIC, focusing on those using poly-I:C. The results showed that the PIC model with poly-I:C is able to mimic the prodrome and both the positive and negative/cognitive dimensions of schizophrenia, depending on the specific gestation time window of the immune challenge. The model resembles the neurobiology and etiology of schizophrenia and has good predictive value. In conclusion, this model is a robust tool for the identification of novel molecular targets during prenatal life, adolescence and adulthood that might contribute to the development of preventive and/or treatment strategies (targeting specific symptoms, i.e., positive or negative/cognitive for this devastating mental disorder, also presenting biosafety as compared to viral infection models. One limitation of this model is the incapacity to model the full spectrum of immune responses normally induced by viral exposure.

  13. Intravenous coronary angiography using the orbital radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsuka, Sadanori; Yamaguchi, Iwao; Wu, Jin; Takeda, Toru; Itai, Yuji; Maruhashi, Akira [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine; Hyodo, Kazuyuki; Ando, Masami [High Energy Accelerator Research Org., Tsukuba, Ibaraki (Japan). Inst. of Materials Structure Science

    2002-09-01

    This review described the progress and current status of intravenous coronary angiography (IVCAG) using the orbital radiation generated by the synchrotron. Authors diagnosed 4 patients of coronary artery disease in 1996 and 33 until 2000. Monochromatic 2-D X-ray beam (2.0 X 10{sup 10} photons/mm{sup 2}/sec, 130 X 75 mm) of 37 keV was obtained by non-symmetrical reflection of synchrotron radiation generated by 5.0 GeV accelerated electron. The use of 2-D beam enabled to give the dynamic IVCAG image in contrast with the static image by the 1-D slit beam. Intermittent irradiation (5 msec/100 msec) reduced the exposure dose to <750 mSv. Images were recorded in the Sony digital video-recorder placed behind the Sony Charge-coupled device (CCD) camera and Toshiba photo-multiplier, and gave the precision of 1 mm of the artery. The IVCAG by synchrotron radiation reduced patients' burden and was expected to be more widely used in future. (K.H.)

  14. Cardiac complications of intravenous digital subtraction angiography

    International Nuclear Information System (INIS)

    Neergaard, K.; Dirksen, K.L.; Andersen, I.; Galloee, A.M.; Madsen, E.B.

    1989-01-01

    In a prospective study of 103 patients the incidence of cardiac events during intravenous digital subtraction angiography (i.v. DSA) was investigated. Of 103 patients 17 had known ischaemic heart disease. The examination was performed with an ionic contrast medium, Urografin 76% (sodium megluminediatrizoate), administered by bolus injection into the right atrium. Patients with severe cardiac disease were examined only if the procedure was considered of vital importance. Cardiac events were defined as ST-segment changes of more than 0.1 mV, changes in heart rate of more than 20%, arrhythmias and such symptoms as chest pain and dyspnoea. Ischaemic ST-segment changes during i.v. DSA were observed in approximately 20% of the patients and were not related to the presence of known ischaemic heart disease. Three patients developed angina during the procedure. Among 12 patients with known angina only one patient developed angina during the procedure. In this study chest pain was infrequent (3%), but there was a relative high frequency of ECG changes (20%) not related to patients with ischaemic heart disease only. It is concluded that there is a risk of cardiac events during i.v. DSA, but the risk is not increased in patients with known ischaemic heart disease (if they do not suffer from congestive heart failure) as compared with other patients without known ischaemic heart disease. (orig.)

  15. MYCOTIC FEMORAL PSEUDOANEURYSMS FROM INTRAVENOUS DRUG ABUSE

    Directory of Open Access Journals (Sweden)

    Vojko Flis

    2004-04-01

    Full Text Available Background. Parenteral drug abuse is the most common cause of infected femoral artery pseudoaneurysms (IFAP. This complication of intravenous drug abuse is not only limb threatening but can also be life threatening. The management of the IFAP is difficult and controversial. Generally speaking, ligation and excision of the pseudoaneurysm without revascularization is accepted procedure in majority of the patients. However it is not regarded as an appropriate procedure for cases where the high probability of amputation is expected from acute interruption of the femoral artery flow.Patients, methods and results. We present three cases of young (average 20 years, range 18–24 patients with IFAP, in which a primary reconstruction was performed due to absence of doppler signal over pedal arteries after ligation of common femoral artery. In two of them complications in form of haemorrhage and repeated infection developed in late postoperative period. The first one, had an excision and ligation while the second one had a reconstruction made by means of a silver impregnated dacron prosthesis. None of the patients required an amputation.Conclusions. Overall prognosis and prognosis of the reconstruction in parenteral drug abuse patients is uncertain because there is a high incidence of postoperative drug injection despite aggressive drug rehabilitation.

  16. Potential intravenous drug interactions in intensive care

    Directory of Open Access Journals (Sweden)

    Maiara Benevides Moreira

    Full Text Available Abstract OBJECTIVE To analyze potential intravenous drug interactions, and their level of severity associated with the administration of these drugs based on the prescriptions of an intensive care unit. METHOD Quantitative study, with aretrospective exploratory design, and descriptive statistical analysis of the ICU prescriptions of a teaching hospital from March to June 2014. RESULTS The sample consisted of 319 prescriptions and subsamples of 50 prescriptions. The mean number of drugs per patient was 9.3 records, and a higher probability of drug interaction inherent to polypharmacy was evidenced. The study identified severe drug interactions, such as concomitant administration of Tramadol with selective serotonin reuptake inhibitor drugs (e.g., Metoclopramide and Fluconazole, increasing the risk of seizures due to their epileptogenic actions, as well as the simultaneous use of Ranitidine-Fentanyl®, which can lead to respiratory depression. CONCLUSION A previous mapping of prescriptions enables the characterization of the drug therapy, contributing to prevent potential drug interactions and their clinical consequences.

  17. Radiation dose measurements in intravenous pyelography

    International Nuclear Information System (INIS)

    Egeblad, M.; Gottlieb, E.

    1975-01-01

    Intravenous pyelography (IVP) and micturition cystourethrography (MCU) are the standard procedures in the radiological examination of children with urinary tract infections and in the control of these children. Gonad protection against radiation is not possible in MCU, but concerning the girls partly possible in IVP. It is of major importance to know the radiation dose in these procedures, especially since the examination is often repeated in the same patients. All IVP were done by means of the usual technique including possible gonad protection. The thermoluminescence dosimeter was placed rectally in the girls and fixed on the scrota in the boys. A total of 50 children was studied. Gonad dose ranged from 140 to 200mR in the girls and from 20 to 70mR in the boys (mean values). The radiation dose in IVP is very low compared to that of MCU, and from this point of view IVP is a dose saving examination in the control of children with urinary tract infections [fr

  18. Repeated intravenous doxapram induces phrenic motor facilitation.

    Science.gov (United States)

    Sandhu, M S; Lee, K Z; Gonzalez-Rothi, E J; Fuller, D D

    2013-12-01

    Doxapram is a respiratory stimulant used to treat hypoventilation. Here we investigated whether doxapram could also trigger respiratory neuroplasticity. Specifically, we hypothesized that intermittent delivery of doxapram at low doses would lead to long-lasting increases (i.e., facilitation) of phrenic motor output in anesthetized, vagotomized, and mechanically-ventilated rats. Doxapram was delivered intravenously in a single bolus (2 or 6mg/kg) or as a series of 3 injections (2mg/kg) at 5min intervals. Control groups received pH-matched saline injections (vehicle) or no treatment (anesthesia time control). Doxapram evoked an immediate increase in phrenic output in all groups, but a persistent increase in burst amplitude only occurred after repeated dosing with 2mg/kg. At 60min following the last injection, phrenic burst amplitude was 168±24% of baseline (%BL) in the group receiving 3 injections (Pphrenic response to doxapram (2mg/kg) was reduced by 68% suggesting that at low doses the drug was acting primarily via the carotid chemoreceptors. We conclude that intermittent application of doxapram can trigger phrenic neuroplasticity, and this approach might be of use in the context of respiratory rehabilitation following neurologic injury. © 2013.

  19. Drugs for Neglected Diseases initiative model of drug development for neglected diseases: current status and future challenges.

    Science.gov (United States)

    Ioset, Jean-Robert; Chang, Shing

    2011-09-01

    The Drugs for Neglected Diseases initiative (DNDi) is a patients' needs-driven organization committed to the development of new treatments for neglected diseases. Created in 2003, DNDi has delivered four improved treatments for malaria, sleeping sickness and visceral leishmaniasis. A main DNDi challenge is to build a solid R&D portfolio for neglected diseases and to deliver preclinical candidates in a timely manner using an original model based on partnership. To address this challenge DNDi has remodeled its discovery activities from a project-based academic-bound network to a fully integrated process-oriented platform in close collaboration with pharmaceutical companies. This discovery platform relies on dedicated screening capacity and lead-optimization consortia supported by a pragmatic, structured and pharmaceutical-focused compound sourcing strategy.

  20. A Simple Model for Complex Fabrication of MEMS based Pressure Sensor: A Challenging Approach

    Directory of Open Access Journals (Sweden)

    Himani SHARMA

    2010-08-01

    Full Text Available In this paper we have presented the simple model for complex fabrication of MEMS based absolute micro pressure sensor. This kind of modeling is extremely useful for determining its complexity in fabrication steps and provides complete information about process sequence to be followed during manufacturing. Therefore, the need for test iteration decreases and cost, time can be reduced significantly. By using DevEdit tool (part of SILVACO tool, a behavioral model of pressure sensor have been presented and implemented.

  1. Nucleic acid reactivity : challenges for next-generation semiempirical quantum models

    OpenAIRE

    Huang, Ming; Giese, Timothy J.; York, Darrin M.

    2015-01-01

    Semiempirical quantum models are routinely used to study mechanisms of RNA catalysis and phosphoryl transfer reactions using combined quantum mechanical/molecular mechanical methods. Herein, we provide a broad assessment of the performance of existing semiempirical quantum models to describe nucleic acid structure and reactivity in order to quantify their limitations and guide the development of next-generation quantum models with improved accuracy. Neglect of diatomic diffierential overlap (...

  2. New Economy And Global Challenge: Winning Model Of Successful Small Business Organizations

    OpenAIRE

    Mirjana Radovic Markovic

    2007-01-01

    The old principles no longer work in the age of Globalization. Businesses have reached the old model's limits with respect to complexity and speed. The real problem is a ruinously dysfunctional mismatch between today's business environment and the classic business model. Namely, the wrong model may transform a company into the vehicle of its own death. Great shifts - genuine and radical transformation- have been shaping the economy and business environment in recent decades. Technology, espec...

  3. Contemporary challenges in applying of the modified model CAPM with country risk premium in emerging economies

    OpenAIRE

    Petrović Dragana

    2017-01-01

    Modern approach in determining the expected return of foreign investors' investments is based on the evaluation investment in capital asset-CAPM (Capital Asset Pricing Model). In order to use the CAPM model for calculating the expected return of foreign investors in growing economies, it is developed the extended model CAPM with the risk premium in the country. This variant of the CAPM model has been used for estimating the cost of capital. This is the expected return on a portfolio of the co...

  4. Nucleic acid reactivity: challenges for next-generation semiempirical quantum models.

    Science.gov (United States)

    Huang, Ming; Giese, Timothy J; York, Darrin M

    2015-07-05

    Semiempirical quantum models are routinely used to study mechanisms of RNA catalysis and phosphoryl transfer reactions using combined quantum mechanical (QM)/molecular mechanical methods. Herein, we provide a broad assessment of the performance of existing semiempirical quantum models to describe nucleic acid structure and reactivity to quantify their limitations and guide the development of next-generation quantum models with improved accuracy. Neglect of diatomic differential overlap and self-consistent density-functional tight-binding semiempirical models are evaluated against high-level QM benchmark calculations for seven biologically important datasets. The datasets include: proton affinities, polarizabilities, nucleobase dimer interactions, dimethyl phosphate anion, nucleoside sugar and glycosidic torsion conformations, and RNA phosphoryl transfer model reactions. As an additional baseline, comparisons are made with several commonly used density-functional models, including M062X and B3LYP (in some cases with dispersion corrections). The results show that, among the semiempirical models examined, the AM1/d-PhoT model is the most robust at predicting proton affinities. AM1/d-PhoT and DFTB3-3ob/OPhyd reproduce the MP2 potential energy surfaces of 6 associative RNA phosphoryl transfer model reactions reasonably well. Further, a recently developed linear-scaling "modified divide-and-conquer" model exhibits the most accurate results for binding energies of both hydrogen bonded and stacked nucleobase dimers. The semiempirical models considered here are shown to underestimate the isotropic polarizabilities of neutral molecules by approximately 30%. The semiempirical models also fail to adequately describe torsion profiles for the dimethyl phosphate anion, the nucleoside sugar ring puckers, and the rotations about the nucleoside glycosidic bond. The modeling of pentavalent phosphorus, particularly with thio substitutions often used experimentally as mechanistic

  5. Evolution and challenges of dynamic global vegetation models for some aspects of plant physiology and elevated atmospheric CO2.

    Science.gov (United States)

    Rezende, L F C; Arenque, B C; Aidar, S T; Moura, M S B; Von Randow, C; Tourigny, E; Menezes, R S C; Ometto, J P H B

    2016-07-01

    Dynamic global vegetation models (DGVMs) simulate surface processes such as the transfer of energy, water, CO2, and momentum between the terrestrial surface and the atmosphere, biogeochemical cycles, carbon assimilation by vegetation, phenology, and land use change in scenarios of varying atmospheric CO2 concentrations. DGVMs increase the complexity and the Earth system representation when they are coupled with atmospheric global circulation models (AGCMs) or climate models. However, plant physiological processes are still a major source of uncertainty in DGVMs. The maximum velocity of carboxylation (Vcmax), for example, has a direct impact over productivity in the models. This parameter is often underestimated or imprecisely defined for the various plant functional types (PFTs) and ecosystems. Vcmax is directly related to photosynthesis acclimation (loss of response to elevated CO2), a widely known phenomenon that usually occurs when plants are subjected to elevated atmospheric CO2 and might affect productivity estimation in DGVMs. Despite this, current models have improved substantially, compared to earlier models which had a rudimentary and very simple representation of vegetation-atmosphere interactions. In this paper, we describe this evolution through generations of models and the main events that contributed to their improvements until the current state-of-the-art class of models. Also, we describe some main challenges for further improvements to DGVMs.

  6. Developing an inter-enterprise alignment maturity model: research challenges and solutions

    NARCIS (Netherlands)

    Santana Tapia, R.G.; Daneva, Maia; van Eck, Pascal

    Business-IT alignment is pervasive today, as organizations strive to achieve competitive advantage. Like in other areas, e.g., software development, maintenance and IT services, there are maturity models to assess such alignment. Those models, however, do not specifically address the aspects needed

  7. Modelling micro-pollutant fate in wastewater collection and treatment systems: status and challenges

    DEFF Research Database (Denmark)

    Plósz, Benedek G.; Benedetti, L.; Daigger, G. T.

    2013-01-01

    of such models. In brief, we conclude that, in order to predict the contaminant removal in centralised treatment works, considering the dramatic improvement in monitoring and detecting MPs in wastewater, more mechanistic approaches should be used to complement conventional, heuristic and other fate models...

  8. Assessing healthcare process maturity: challenges of using a business process maturity model

    NARCIS (Netherlands)

    Tarhan, A.; Turetken, O.; van den Biggelaar, F.J.H.M.

    2015-01-01

    Doi: 10.4108/icst.pervasivehealth.2015.259105 The quality of healthcare services is influenced by the maturity of healthcare processes used to develop it. A maturity model is an instrument to assess and continually improve organizational processes. In the last decade, a number of maturity models

  9. Advantages and Challenges of Using Physics Curricula as a Model for Reforming an Undergraduate Biology Course

    Science.gov (United States)

    Donovan, D. A.; Atkins, L. J.; Salter, I. Y.; Gallagher, D. J.; Kratz, R. F.; Rousseau, J. V.; Nelson, G. D.

    2013-01-01

    We report on the development of a life sciences curriculum, targeted to undergraduate students, which was modeled after a commercially available physics curriculum and based on aspects of how people learn. Our paper describes the collaborative development process and necessary modifications required to apply a physics pedagogical model in a life…

  10. Challenges Associated With Applying Physiologically Based Pharmacokinetic Modeling for Public Health Decision-Making

    Science.gov (United States)

    The development and application of physiologically based pharmacokinetic (PBPK) models in chemical toxicology have grown steadily since their emergence in the 1980s. However, critical evaluation of PBPK models to support public health decision-making across federal agencies has t...

  11. Modeling neurodegenerative diseases with patient-derived induced pluripotent cells: Possibilities and challenges.

    Science.gov (United States)

    Poon, Anna; Zhang, Yu; Chandrasekaran, Abinaya; Phanthong, Phetcharat; Schmid, Benjamin; Nielsen, Troels T; Freude, Kristine K

    2017-10-25

    The rising prevalence of progressive neurodegenerative diseases coupled with increasing longevity poses an economic burden at individual and societal levels. There is currently no effective cure for the majority of neurodegenerative diseases and disease-affected tissues from patients have been difficult to obtain for research and drug discovery in pre-clinical settings. While the use of animal models has contributed invaluable mechanistic insights and potential therapeutic targets, the translational value of animal models could be further enhanced when combined with in vitro models derived from patient-specific induced pluripotent stem cells (iPSCs) and isogenic controls generated using CRISPR-Cas9 mediated genome editing. The iPSCs are self-renewable and capable of being differentiated into the cell types affected by the diseases. These in vitro models based on patient-derived iPSCs provide the opportunity to model disease development, uncover novel mechanisms and test potential therapeutics. Here we review findings from iPSC-based modeling of selected neurodegenerative diseases, including Alzheimer's disease, frontotemporal dementia and spinocerebellar ataxia. Furthermore, we discuss the possibilities of generating three-dimensional (3D) models using the iPSCs-derived cells and compare their advantages and disadvantages to conventional two-dimensional (2D) models. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Comparison of analgesic efficacy of intravenous Paracetamol and intravenous dexketoprofen trometamol in multimodal analgesia after hysterectomy.

    Science.gov (United States)

    Unal, Ciğdem; Cakan, Türkay; Baltaci, Bülent; Başar, Hülya

    2013-10-01

    [corrected] We aimed to evaluate analgesic efficacy, opioid-sparing, and opioid-related adverse effects of intravenous paracetamol and intravenous dexketoprofen trometamol in combination with iv morphine after total abdominal hysterectomy. Sixty American Society of Anesthesiologist Physical Status Classification I-II patients scheduled for total abdominal hysterectomy were enrolled to this double-blinded, randomized, placebo controlled, and prospective study. Patients were divided into three groups as paracetamol, dexketoprofen trometamol, and placebo (0.9% NaCl) due to their post-operative analgesic usage. Intravenous patient controlled analgesia morphine was used as a rescue analgesic in all groups. Pain scores, hemodynamic parameters, morphine consumption, patient satisfaction, and side-effects were evaluated. Visual Analog Scale (VAS) scores were not statistically significantly different among the groups in all evaluation times, but decrease in VAS scores was statistically significant after the evaluation at 12(th) h in all groups. Total morphine consumption (morphine concentration = 0.2 mg/ml) in group paracetamol (72.3 ± 38.0 ml) and dexketoprofen trometamol (69.3 ± 24.1 ml) was significantly lower than group placebo (129.3 ± 22.6 ml) (P dexketoprofen trometamol after surgery and the increase in global satisfaction score was significant only in group placebo. Dexketoprofen trometamol and Paracetamol didn't cause significant change on pain scores, but increased patients' comfort. Although total morphine consumption was significantly decreased by both drugs, the incidence of nausea and vomiting were similar among the groups. According to results of the present study routine addition of dexketoprofen trometamol and paracetamol to patient controlled analgesia morphine after hysterectomies is not recommended.

  13. Comparison of analgesic efficacy of intravenous Paracetamol and intravenous dexketoprofen trometamol in multimodal analgesia after hysterectomy

    Directory of Open Access Journals (Sweden)

    Çiğdem Ünal

    2013-01-01

    Full Text Available Backround: We aimed to evaluate analgesic efficacy, opioid-sparing, and opioid-related adverse effects of intravenous paracetamol and intravenous dexketoprofen trometamol in combination with iv morphine after total abdominal hysterectomy. Materials and Methods: Sixty American Society of Anesthesiologist Physical Status Classification I-II patients scheduled for total abdominal hysterectomy were enrolled to this double-blinded, randomized, placebo controlled, and prospective study. Patients were divided into three groups as paracetamol, dexketoprofen trometamol, and placebo (0.9% NaCl due to their post-operative analgesic usage. Intravenous patient controlled analgesia morphine was used as a rescue analgesic in all groups. Pain scores, hemodynamic parameters, morphine consumption, patient satisfaction, and side-effects were evaluated. Results: Visual Analog Scale (VAS scores were not statistically significantly different among the groups in all evaluation times, but decrease in VAS scores was statistically significant after the evaluation at 12 th h in all groups. Total morphine consumption (morphine concentration = 0.2 mg/ml in group paracetamol (72.3 ± 38.0 ml and dexketoprofen trometamol (69.3 ± 24.1 ml was significantly lower than group placebo (129.3 ± 22.6 ml (P < 0.001. Global satisfaction scores of the patients in group placebo was significantly lower than group dexketoprofen trometamol after surgery and the increase in global satisfaction score was significant only in group placebo. Conclusion: Dexketoprofen trometamol and Paracetamol didn′t cause significant change on pain scores, but increased patients′ comfort. Although total morphine consumption was significantly decreased by both drugs, the incidence of nausea and vomiting were similar among the groups. According to results of the present study routine addition of dexketoprofen trometamol and paracetamol to patient controlled analgesia morphine after hysterectomies is not

  14. The Demand Side in Economic Models of Energy Markets: The Challenge of Representing Consumer Behavior

    International Nuclear Information System (INIS)

    Krysiak, Frank C.; Weigt, Hannes

    2015-01-01

    Energy models play an increasing role in the ongoing energy transition processes either as tools for forecasting potential developments or for assessments of policy and market design options. In recent years, these models have increased in scope and scale and provide a reasonable representation of the energy supply side, technological aspects and general macroeconomic interactions. However, the representation of the demand side and consumer behavior has remained rather simplistic. The objective of this paper is twofold. First, we review existing large-scale energy model approaches, namely bottom-up and top-down models, with respect to their demand-side representation. Second, we identify gaps in existing approaches and draft potential pathways to account for a more detailed demand-side and behavior representation in energy modeling.

  15. The Demand Side in Economic Models of Energy Markets: The Challenge of Representing Consumer Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Krysiak, Frank C., E-mail: frank.krysiak@unibas.ch; Weigt, Hannes [Department of Business and Economics, University of Basel, Basel (Switzerland)

    2015-05-19

    Energy models play an increasing role in the ongoing energy transition processes either as tools for forecasting potential developments or for assessments of policy and market design options. In recent years, these models have increased in scope and scale and provide a reasonable representation of the energy supply side, technological aspects and general macroeconomic interactions. However, the representation of the demand side and consumer behavior has remained rather simplistic. The objective of this paper is twofold. First, we review existing large-scale energy model approaches, namely bottom-up and top-down models, with respect to their demand-side representation. Second, we identify gaps in existing approaches and draft potential pathways to account for a more detailed demand-side and behavior representation in energy modeling.

  16. The Demand Side in Economic Models of Energy Markets: The Challenge of Representing Consumer Behavior

    Directory of Open Access Journals (Sweden)

    Frank eKrysiak

    2015-05-01

    Full Text Available Energy models play an increasing role in the ongoing energy transition processes either as tools for forecasting potential developments or for assessments of policy and market design options. In recent years these models have increased in scope and scale and provide a reasonable representation of the energy supply side, technological aspects and general macroeconomic interactions. However, the representation of the demand side and consumer behavior has remained rather simplistic. The objective of this paper is twofold. First, we review existing large scale energy model approaches, namely bottom-up and top-down models, with respect to their demand side representation. Second, we identify gaps in existing approaches and draft potential pathways to account for a more detailed demand side and behavior representation in energy modeling.

  17. Cluster models of light nuclei and the method of hyperspherical harmonics: Successes and challenges

    International Nuclear Information System (INIS)

    Danilin, B. V.; Shul'gina, N. B.; Ershov, S. N.; Vaagen, J. S.

    2009-01-01

    Hyperspherical-harmonics method to investigate the lightest nuclei having three-cluster structure is discussed together with recent experiments. Properties of bound states and methods to explore three-body continuum are presented. The challenges created by large neutron excess and halo phenomena are highlighted. Astrophysical aspects of the 7 Li + n → 8 Li + γ reaction and the solar-boron-neutrinos problem are analyzed. Three-cluster structure of highly excited states in 8 Be is shown to be responsible for extreme isospin mixing. Progress in studies of 6 He- and 11 Li-induced inclusive and exclusive nuclear reactions is demonstrated, providing information on the nature of continuum structures of Borromean nuclei.

  18. Current status of deepwater oil spill modelling in the Faroe-Shetland Channel, Northeast Atlantic, and future challenges.

    Science.gov (United States)

    Gallego, Alejandro; O'Hara Murray, Rory; Berx, Barbara; Turrell, William R; Beegle-Krause, C J; Inall, Mark; Sherwin, Toby; Siddorn, John; Wakelin, Sarah; Vlasenko, Vasyl; Hole, Lars R; Dagestad, Knut Frode; Rees, John; Short, Lucy; Rønningen, Petter; Main, Charlotte E; Legrand, Sebastien; Gutierrez, Tony; Witte, Ursula; Mulanaphy, Nicole

    2018-02-01

    As oil reserves in established basins become depleted, exploration and production moves towards relatively unexploited areas, such as deep waters off the continental shelf. The Faroe-Shetland Channel (FSC, NE Atlantic) and adjacent areas have been subject to increased focus by the oil industry. In addition to extreme depths, metocean conditions in this region characterise an environment with high waves and strong winds, strong currents, complex circulation patterns, sharp density gradients, and large small- and mesoscale variability. These conditions pose operational challenges to oil spill response and question the suitability of current oil spill modelling frameworks (oil spill models and their forcing data) to adequately simulate the behaviour of a potential oil spill in the area. This article reviews the state of knowledge relevant to deepwater oil spill modelling for the FSC area and identifies knowledge gaps and research priorities. Our analysis should be relevant to other areas of complex oceanography. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  19. Research advances and challenges in one-dimensional modeling of secondary settling tanks--a critical review.

    Science.gov (United States)

    Li, Ben; Stenstrom, M K

    2014-11-15

    Sedimentation is one of the most important processes that determine the performance of the activated sludge process (ASP), and secondary settling tanks (SSTs) have been frequently investigated with the mathematical models for design and operation optimization. Nevertheless their performance is often far from satisfactory. The starting point of this paper is a review of the development of settling theory, focusing on batch settling and the development of flux theory, since they played an important role in the early stage of SST investigation. The second part is an explicit review of the established 1-D SST models, including the relevant physical law, various settling behaviors (hindered, transient, and compression settling), the constitutive functions, and their advantages and disadvantages. The third part is a discussion of numerical techniques required to solve the governing equation, which is usually a partial differential equation. Finally, the most important modeling challenges, such as settleability description, settling behavior understanding, are presented. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Contemporary challenges in applying of the modified model CAPM with country risk premium in emerging economies

    Directory of Open Access Journals (Sweden)

    Petrović Dragana

    2017-01-01

    Full Text Available Modern approach in determining the expected return of foreign investors' investments is based on the evaluation investment in capital asset-CAPM (Capital Asset Pricing Model. In order to use the CAPM model for calculating the expected return of foreign investors in growing economies, it is developed the extended model CAPM with the risk premium in the country. This variant of the CAPM model has been used for estimating the cost of capital. This is the expected return on a portfolio of the company's stocks in less developed countries. Those countries have certain problems and factors of risk investment. This research examines the limitations and shortcomings in the application of the extended model with country risk premium, during the calculation of the cost of capital in the less developed economies. We present possible models to overcome those problems and also a need for upgrading of modified CAPM model with a risk premium of the country which, beside risk of the country (CR must have a discount for the 'advantage of the country'.