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Sample records for delayed release pancrelipase

  1. Efficacy and Safety of a New Formulation of Pancrelipase (Ultrase MT20 in the Treatment of Malabsorption in Exocrine Pancreatic Insufficiency in Cystic Fibrosis

    Directory of Open Access Journals (Sweden)

    Michael W. Konstan

    2010-01-01

    Full Text Available Background. Pancreatic enzyme replacement therapy is the standard of care for treatment of malabsorption in patients with cystic fibrosis (CF and exocrine pancreatic insufficiency (PI. Aim. To evaluate efficacy and safety of a new formulation of pancrelipase (Ultrase MT20 in patients with CF and PI. Coefficients of fat absorption (CFA% and nitrogen absorption (CNA% were the main efficacy parameters. Safety was evaluated by monitoring laboratory analyses, adverse events (AEs, and overall signs and symptoms. Methods. Patients (n=31 were randomized in a crossover design comparing this pancrelipase with placebo during 2 inpatient evaluation periods (6-7 days each. Fat and protein/nitrogen ingestion and excretion were measured from food diaries and 72-hour stool collections. CFA% and CNA% were calculated for each period and compared. Results. Twenty-four patients provided analyzable data. This pancrelipase increased mean CFA% and CNA% (+34.7% and +25.7%, resp., P<.0001 for both, reduced stool frequency, and improved stool consistency compared with placebo. Placebo-treated patients reported more AEs, with gastrointestinal symptoms being the most frequently reported AE. Conclusions. This pancrelipase is a safe and effective treatment for malabsorption associated with exocrine PI in patients with CF.

  2. Investigation of delayed fission gas release

    International Nuclear Information System (INIS)

    Cayet, Nicolas

    1996-05-01

    The study of the fission gas release process in the high burnup rig IFA-562 has revealed a particular fuel behaviour: a delay in the fission gas release process. It appeared that an important release of gas was measured by the pressure transducers once the power had decreased, whereas, during steady-state operation, the pressure did not increase very much. After examinations, the gap size has been concluded to be the main parameter involving this delay. However the burnup could have been a potential factor, its role is mainly to close the gap by swelling. The observations of low burnup rods have shown the same delayed fission gas release, the gap being small by design and closed essentially by thermal expansion. The study of the kinetics has demonstrated the time-independency of the phenomenon. Thus the proposed mechanism driving this delayed fission gas release would involve three consecutives stages. During steady-state, the gas is released into the interlinkage network of grain boundary bubbles and cracks. Due to the closed gap, the gas is trapped in some void volumes, unable to escape the pellet. During power reduction, the gap and some old/new cracks open, immediately providing a path for the gas to the pressure transducers and explaining this delay in the fission gas release. (author)

  3. Bioavailability and stability of erythromycin delayed release tablets.

    Science.gov (United States)

    Ogwal, S; Xide, T U

    2001-12-01

    Erythromycin is available as the free base, ethylsuccinate, estolate, stearate, gluceptate, and lactobionate derivatives. When given orally erythromycin and its derivatives except the estolate are inactivated to some extent by the gastric acid and poor absorption may result. To establish whether delayed release erythromycin tablets meet the bioequivalent requirement for the market. Sectrophotometric analysis was used to determine the dissolution percentage of the tablets in vitro. High performance liquid chromatography and IBM/XT microcomputer was used to determine the bioavailability and pharmacokinetic parameters in vivo. Dissolution percentage in thirty minutes reached 28.9% and in sixty minutes erythromycin was completely released. The parameters of the delayed release tablets were Tlag 2.3 hr, Tmax.4.5 hr, and Cmax 2.123 g/ml Ka 0.38048 hr(-1) T (1/2) 1.8 hr, V*C/F 49.721 AUC 12.9155. The relative bioavailability of erythromycin delayed release tablet to erythromycin capsules was 105.31% The content, appearance, and dissolution bioavailability of delayed release erythromycin tablets conforms to the United States pharmacopoeia standards. The tablets should be stored in a cool and dry place in airtight containers and the shelf life is temporarily assigned two years.

  4. Layered lipid microcapsules for mesalazine delayed-release in children.

    Science.gov (United States)

    Balducci, Anna Giulia; Colombo, Gaia; Corace, Giuseppe; Cavallari, Cristina; Rodriguez, Lorenzo; Buttini, Francesca; Colombo, Paolo; Rossi, Alessandra

    2011-12-15

    The goal was to make available a delayed-release dosage form of mesalazine to be dispersed in water to facilitate swallowing in adults and children. Mesalazine microparticles containing carnauba wax were prepared by spray-congealing technique. A second step of spray-congealing of carnauba microparticles dispersed in liquefied stearic acid gave rise to mesalazine lipid microcapsules in which several carnauba microparticles remained embedded as cores in a reservoir structure. In order to favor their water dispersion, the lipid microcapsules were dry coated by tumbling them with different ratios of mannitol/lecithin microparticles prepared by spray-drying. Release rate measurements showed a delayed-release behavior, in particular a pH-dependence with less than 10% of drug released in acidic medium and complete release in phosphate buffer pH 7.4 in 4-5h. The layering with hydrophilic excipient microparticles allowed manufacturing of a pH-dependent dosage form suitable for extemporaneous oral use in adults and children. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Delayed release pancrelipase for treatment of pancreatic exocrine insufficiency associated with chronic pancreatitis

    Directory of Open Access Journals (Sweden)

    Devi Mukkai Krishnamurty

    2009-07-01

    Full Text Available Devi Mukkai Krishnamurty,1 Atoosa Rabiee,2 Sanjay B Jagannath,1 Dana K Andersen2Johns Hopkins University School of Medicine; 1Department of Medicine; 2Department of Surgery, Johns Hopkins Hospital, Baltimore, MD, USA; 2Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, Baltimore, MD, USAAbstract: Pancreatic enzyme supplements (PES are used in chronic pancreatitis (CP for correction of pancreatic exocrine insufficiency (PEI as well as pain and malnutrition. The use of porcine pancreatic enzymes for the correction of exocrine insufficiency is governed by the pathophysiology of the disease as well as pharmacologic properties of PES. Variability in bioequivalence of PES has been noted on in vitro and in vivo testing and has been attributed to the differences in enteric coating and the degree of micro-encapsulation. As a step towards standardizing pancreatic enzyme preparations, the Food and Drug Administration now requires the manufacturers of PES to obtain approval of marketed formulations by April 2010. In patients with treatment failure, apart from evaluating drug and dietary interactions and compliance, physicians should keep in mind that patients may benefit from switching to a different formulation. The choice of PES (enteric coated versus non-enteric coated and the need for acid suppression should be individualized. There is no current standard test for evaluating adequacy of therapy in CP patients and studies have shown that optimization of therapy based on symptoms may be inadequate. Goals of therapy based on overall patient presentation and specific laboratory tests rather than mere correction of steatorrhea are needed.Keywords: pancreatic exocrine insufficiency, chronic pancreatitis, pancreatic enzyme supplement

  6. Management Strategies to Facilitate Optimal Outcomes for Patients Treated with Delayed-release Dimethyl Fumarate.

    Science.gov (United States)

    Mayer, Lori; Fink, Mary Kay; Sammarco, Carrie; Laing, Lisa

    2018-04-01

    Delayed-release dimethyl fumarate is an oral disease-modifying therapy that has demonstrated significant efficacy in adults with relapsing-remitting multiple sclerosis. Incidences of flushing and gastrointestinal adverse events are common in the first month after delayed-release dimethyl fumarate initiation. Our objective was to propose mitigation strategies for adverse events related to initiation of delayed-release dimethyl fumarate in the treatment of patients with multiple sclerosis. Studies of individually developed mitigation strategies and chart reviews were evaluated. Those results, as well as mitigation protocols developed at multiple sclerosis care centers, are summarized. Key steps to optimize the effectiveness of delayed-release dimethyl fumarate treatment include education prior to and at the time of delayed-release dimethyl fumarate initiation, initiation dose protocol gradually increasing to maintenance dose, dietary suggestions for co-administration with food, gastrointestinal symptom management with over-the-counter medications, flushing symptom management with aspirin, and temporary dose reduction. Using the available evidence from clinical trials and evaluations of post-marketing studies, these strategies to manage gastrointestinal and flushing symptoms can be effective and helpful to the patient when initiating delayed-release dimethyl fumarate.

  7. Formulation, Development and Evaluation of delayed release capsules of Duloxetine Hydrochloride made of different Enteric Polymers

    OpenAIRE

    Pallavi Yerramsetty; J. Vijaya Ratna; Venkata Ramana Reddy; Praveen Kumar

    2012-01-01

    Delayed release systems have acquired a centre stage in the arena of pharmaceutical research and development. The present study involves formulation and evaluation of Duloxetine Hydrochloride delayed release capsules. Duloxetine Hydrochloride is an acid labile drug. It degrades in the acidic environment of the stomach thus leading to therapeutic inefficacy. Therefore it is necessary to bypass the acidic pH of the stomach which can be achieved by formulating delayed release dosage form by usin...

  8. Low molecular weight polylactic acid as a matrix for the delayed release of pesticides.

    Science.gov (United States)

    Zhao, Jing; Wilkins, Richard M

    2005-05-18

    Low molecular weight polylactic acid (LMW PLA) was used as a matrix to formulate biodegradable matrix granules and films with bromacil using a melt process. The compatibility of the PLA with bromacil was evaluated. The release characteristics of the formulations were investigated in vitro. The degradation and erosion of the formulations were monitored by pH and gravimetric analysis during the course of release. Various granules and films had similar biphasic release patterns, a delayed release followed by an explosive release. The release rates were independent of bromacil content in the matrix, but varied with the geometry of matrices. The mechanisms of diffusion and erosion were involved in the release. The delayed release of the formulations was dominantly governed by the degradation and erosion of PLA. LMW PLA underwent bulk erosion. LMW PLA-based matrix formulations could thus be useful for the application of pesticides to sensitive targets such as seed treatment.

  9. Quality evaluation of extemporaneous delayed-release liquid formulations of lansoprazole.

    Science.gov (United States)

    Melkoumov, Alexandre; Soukrati, Amina; Elkin, Igor; Forest, Jean-Marc; Hildgen, Patrice; Leclair, Grégoire

    2011-11-01

    The quality attributes of extemporaneous delayed-release liquid formulations of lansoprazole for oral administration were evaluated. A novel liquid formulation (3 mg/mL) of Prevacid FasTab in an Ora-Blend vehicle was prepared and compared with the Prevacid FasTab 30 mg and Prevacid-sodium bicarbonate 1 M formulation (3 mg/mL). The latter formulation was combined with hydrochloric acid 0.1 N, and the remaining lansoprazole content was assayed by high-performance liquid chromatography (HPLC). A batch of delayed-release liquid formulation was prepared to evaluate content uniformity. For content assay, three samples were prepared for each evaluated condition and each sample was analyzed in triplicate by HPLC. The lansoprazole in the sodium bicarbonate formulation was extensively degraded by quantities of hydrochloric acid 0.1 N in excess of 100 mL. Storage time and temperature had a significant effect on lansoprazole stability in the Ora-Blend formulation. The drug remained stable for seven days when the formulation was stored at 4.5-5.5 °C, but storage at 21-22 °C or the reduction of pH with citric acid accelerated lansoprazole degradation. The amount of lansoprazole released from the Ora-Blend formulation during the buffer stage of the dissolution test decreased with increases in formulation storage time, in formulation storage temperature, and in the amount of lansoprazole released and degraded during the acid stage of the test. An extemporaneous formulation consisting of lansoprazole microgranules in Ora-Blend maintained acceptable quality attributes when stored for three days at 4.5-5.5 °C.

  10. APF530 (granisetron injection extended-release) in a three-drug regimen for delayed CINV in highly emetogenic chemotherapy.

    Science.gov (United States)

    Schnadig, Ian D; Agajanian, Richy; Dakhil, Christopher; Gabrail, Nashat Y; Smith, Robert E; Taylor, Charles; Wilks, Sharon T; Schwartzberg, Lee S; Cooper, William; Mosier, Michael C; Payne, J Yvette; Klepper, Michael J; Vacirca, Jeffrey L

    2016-06-01

    APF530, extended-release granisetron, provides sustained release for ≥5 days for acute- and delayed-phase chemotherapy-induced nausea and vomiting (CINV). We compared efficacy and safety of APF530 versus ondansetron for delayed CINV after highly emetogenic chemotherapy (HEC), following a guideline-recommended three-drug regimen. HEC patients received APF530 500 mg subcutaneously or ondansetron 0.15 mg/kg intravenously, with dexamethasone and fosaprepitant. Primary end point was delayed-phase complete response (no emesis or rescue medication). A higher percentage of APF530 versus ondansetron patients had delayed-phase complete response (p = 0.014). APF530 was generally well tolerated; treatment-emergent adverse event incidence was similar across arms, mostly mild-to-moderate injection-site reactions. APF530 versus the standard three-drug regimen provided superior control of delayed-phase CINV following HEC. ClinicalTrials.gov : NCT02106494.

  11. Monitoring the hydrolyzation of aspirin during the dissolution testing for aspirin delayed-release tablets with a fiber-optic dissolution system

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2012-10-01

    Full Text Available The purpose of this study was to investigate the hydrolyzation of aspirin during the process of dissolution testing for aspirin delayed-release tablets. Hydrolysis product of salicylic acid can result in adverse effects and affect the determination of dissolution rate assaying. In this study, the technique of differential spectra was employed, which made it possible to monitor the dissolution testing in situ. The results showed that the hydrolyzation of aspirin made the percentage of salicylic acid exceed the limit of free salicylic acid (4.0, and the hydrolyzation may affect the quality detection of aspirin delayed-release tablets. Keywords: Aspirin delayed-release tablets, Drug dissolution test, Fiber-optic dissolution system, UV–vis spectrum

  12. Design of tablets for the delayed and complete release of poorly water-soluble weak base drugs using SBE7M-β-CD as a solubilizing agent.

    Science.gov (United States)

    Rao, Venkatramana M; Zannou, Erika A; Stella, Valentino J

    2011-04-01

    The challenge of designing a delayed-release oral dosage form is significantly increased when the drug substance is poorly water soluble. This manuscript describes the design and characterization of a novel controlled-release film-coated tablet for the pH-triggered delayed and complete release of poorly water-soluble weak base drugs. Delivery of weak bases is specifically highlighted with the use of dipyridamole and prazosin as model compounds. Tailored delayed release is achieved with a combination of an insoluble but semipermeable polymer and an enteric polymer, such as cellulose acetate and hydroxypropyl cellulose phthalate, respectively, as coatings. The extent of the time lag prior to complete release depends on the film-coating composition and thickness. Complete release is achieved by the addition of a cyclodextrin, namely SBE7M-β-CD with or without a pH modifier added to the tablet core to ensure complete solubilization and release of the drug substance. The film-coating properties allow the complex formation/solubilization to occur in situ. Additionally, the drug release rate can be modulated on the basis of the cyclodextrin to drug molar ratio. This approach offers a platform technology for delayed release of potent but poorly soluble drugs and the release can be modulated by adjusting the film-coating composition and thickness and/or the cyclodextrin and pH modifier, if necessary. Copyright © 2010 Wiley-Liss, Inc.

  13. Pharmacokinetics and safety of posaconazole delayed-release tablets for invasive fungal infections

    Directory of Open Access Journals (Sweden)

    Wiederhold NP

    2015-12-01

    Full Text Available Nathan P Wiederhold Departments of Pathology and Medicine/Infectious Diseases, University of Texas Health Science Center at San Antonio, South Texas Reference Laboratories, San Antonio, TX, USA Abstract: Posaconazole is a broad-spectrum triazole antifungal agent with potent activity against various pathogenic fungi, including yeast and moulds. Clinical studies have demonstrated that this agent is efficacious as prophylaxis against invasive fungal infections in patients at high risk, and may also be useful as salvage therapy against invasive aspergillosis and mucormycosis. However, the bioavailability of posaconazole following administration by oral suspension, which was the only formulation clinically available for many years, is highly variable and negatively influenced by several factors. Because of this, many patients had subtherapeutic or undetectable posaconazole levels when the oral suspension was used. To overcome this limitation, a delayed-release tablet was developed and is now available for clinical use. Hot-melt extrusion technology is used to combine a pH-sensitive polymer with posaconazole to produce a formulation that releases the drug in the elevated pH of the intestine where absorption occurs rather than in the low-pH environment of the stomach. This results in enhanced bioavailability and increased posaconazole exposure. Studies in healthy volunteers have demonstrated significantly higher and more consistent exposures with the tablet formulation compared to the oral suspension. In addition, pharmacokinetic parameters following administration of the tablets were not significantly affected by medications that raise gastric pH or increase gastric motility, and the tablets could also be administered without regard to food. Similar results have also been found in patients at high risk for invasive fungal infections who have received posaconazole tablets. The tablet formulation also appears to be well tolerated to date, although data

  14. Development of a new esomeprazole delayed release gastro-resistant pellet formulation with improved storage stability.

    Science.gov (United States)

    Barmpalexis, Panagiotis; Grypioti, Agni

    2018-06-01

    This study describes the development of a new esomeprazole (ESO) delayed release gastro-resistant formulation with improved storage stability. A three-step (drug-, sub(seal)- and enteric-) coating process was employed with the aid of a fluid bed coater. Several formulation factors (namely, size and quantity of starting non-pareil sugar spheres, binder quantity during drug-layering, sub(seal)-coating polymer type, and quantity and enteric coating quantity) were evaluated and the whole process was modeled with the aid of feed-forward back-propagation artificial neural networks (ANNs). Results showed that the selection of small-sized starting spheres (45/60 mesh size) leads to pellet agglomeration, while as sub(seal)-coating weight gain increases a reduction in ESO dissolution rate is observed. The enteric-coating applied (Eudragit L30D-55) showed good gastro-resistant performance in both 0.1 N HCl and pH 4.5 media, while immediate release profiles with more than 85% of ESO being released in less than 30 min were obtained. The effect of cellulose-based sub(seal)-coating polymers, (namely, hydroxypropyl cellulose and hydroxypropylmethyl cellulose) on formulation's storage stability at 40 ± 2 °C/75 ± 5%RH indicated that only hydroxypropylmethyl cellulose was able to stabilize ESO delayed-release formulations in terms of assay, dissolution, impurities, and gastro-resistance performance. Finally, scanning electron microscopy (SEM) analysis revealed smooth and homogeneous external surface/coating layers in all three levels (drug-, sub(seal)-, and enteric- coating), while x-ray diffraction showed no polymorphic transformations.

  15. Delayed power analysis

    International Nuclear Information System (INIS)

    Adamovich, L.A.; Azarov, V.V.

    1999-01-01

    Time dependent core power behavior in a nuclear reactor is described with well-known neutron kinetics equations. At the same time, two portions are distinguished in energy released from uranium nuclei fission; one released directly at fission and another delayed (residual) portion produced during radioactive decay of fission products. While prompt power is definitely described with kinetics equations, the delayed power presentation still remains outstanding. Since in operation the delayed power part is relatively small (about 6%) operation, it can be neglected for small reactivity disturbances assuming that entire power obeys neutron kinetics equations. In case of a high negative reactivity rapidly inserted in core (e.g. reactor scram initiation) the prompt and delayed components can be calculated separately with practically no impact on each other, employing kinetics equations for prompt power and known approximation formulas for delayed portion, named residual in this specific case. Under substantial disturbances the prompt component in the dynamic process becomes commensurable with delayed portion, thus making necessary to take into account their cross impact. A system of differential equations to describe time-dependent behavior of delayed power is presented. Specific NPP analysis shows a way to significantly simplify the task formulation. (author)

  16. Quality of Life is Improved and Kidney Function Preserved in Patients with Nephropathic Cystinosis Treated for 2 Years with Delayed-Release Cysteamine Bitartrate

    NARCIS (Netherlands)

    Langman, C.B.; Greenbaum, L.A.; Grimm, P.; Sarwal, M.; Niaudet, P.; Deschenes, G.; Cornelissen, E.A.M.; Morin, D.; Cochat, P.; Elenberg, E.; Hanna, C.; Gaillard, S.; Bagger, M.J.; Rioux, P.

    2014-01-01

    OBJECTIVES: To determine the long-term effects of delayed-release cysteamine bitartrate (DR-CYS) based on our previous work that established the short-term noninferiority of DR-CYS every 12 hours compared with immediate-release cysteamine bitartrate every 6 hours. STUDY DESIGN: We conducted a

  17. Pancrelipase

    Science.gov (United States)

    ... that causes the body to produce thick, sticky mucus that may clog the pancreas, the lungs, and ... mix the capsule contents with formula or breast-milk. You can also sprinkle the contents directly into ...

  18. Fabricating a Shell-Core Delayed Release Tablet Using Dual FDM 3D Printing for Patient-Centred Therapy.

    Science.gov (United States)

    Okwuosa, Tochukwu C; Pereira, Beatriz C; Arafat, Basel; Cieszynska, Milena; Isreb, Abdullah; Alhnan, Mohamed A

    2017-02-01

    Individualizing gastric-resistant tablets is associated with major challenges for clinical staff in hospitals and healthcare centres. This work aims to fabricate gastric-resistant 3D printed tablets using dual FDM 3D printing. The gastric-resistant tablets were engineered by employing a range of shell-core designs using polyvinylpyrrolidone (PVP) and methacrylic acid co-polymer for core and shell structures respectively. Filaments for both core and shell were compounded using a twin-screw hot-melt extruder (HME). CAD software was utilized to design a capsule-shaped core with a complementary shell of increasing thicknesses (0.17, 0.35, 0.52, 0.70 or 0.87 mm). The physical form of the drug and its integrity following an FDM 3D printing were assessed using x-ray powder diffractometry (XRPD), thermal analysis and HPLC. A shell thickness ≥0.52 mm was deemed necessary in order to achieve sufficient core protection in the acid medium. The technology proved viable for incorporating different drug candidates; theophylline, budesonide and diclofenac sodium. XRPD indicated the presence of theophylline crystals whilst budesonide and diclofenac sodium remained amorphous in the PVP matrix of the filaments and 3D printed tablets. Fabricated tablets demonstrated gastric resistant properties and a pH responsive drug release pattern in both phosphate and bicarbonate buffers. Despite its relatively limited resolution, FDM 3D printing proved to be a suitable platform for a single-process fabrication of delayed release tablets. This work reveals the potential of dual FDM 3D printing as a unique platform for personalising delayed release tablets to suit an individual patient's needs.

  19. Inhibitory effect of ramosetron on corticotropin releasing factor- and soybean oil-induced delays in gastric emptying in rats.

    Science.gov (United States)

    Hirata, Takuya; Keto, Yoshihiro; Yamano, Mayumi; Yokoyama, Toshihide; Sengoku, Takanori; Seki, Nobuo

    2012-09-01

    Symptoms of functional dyspepsia (FD) are highly prevalent in patients with irritable bowel syndrome (IBS). However, the effects of therapeutic agents for IBS on the pathophysiology of FD are unclear. In this study, therefore, we examined the effects of ramosetron, a serotonin 5-HT(3) receptor antagonist, on corticotropin releasing factor (CRF)- and soybean oil-induced delays in gastric emptying of rats, in comparison with anti-diarrheal agent and spasmolytics. The involvement of 5-HT and the 5-HT(3) receptor in delayed gastric emptying was also evaluated. Corticotropin releasing factor was administered intravenously to rats 10min before oral administration of 0.05% phenol red solution, and the amount remaining in the stomach was measured after 30min. Soybean oil was administered orally with glass beads, and the number of residual beads in the stomach was counted 1h later. Both CRF and soybean oil inhibited gastric emptying dose-dependently. Ramosetron and itopride, a gastro-prokinetic agent, significantly reduced both CRF- and soybean oil-induced delays in gastric emptying, while an anti-diarrheal agent and spasmolytics aggravated them. Pretreatment with p-chlorophenylalanine for 2days to reduced the synthesis of endogenous 5-HT diminished the effects of both CRF and soybean oil on gastric emptying. A 5-HT(3) receptor agonist m-chlorophenylbiguanide suppressed gastric emptying of both phenol red and glass beads, and those effects were reversed by ramosetron. These results suggest that CRF and soybean oil suppress gastric emptying in rats by activating 5-HT(3) receptors, and that by antagonizing these receptors, ramosetron may ameliorate symptoms of FD in clinical settings. © 2012 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.

  20. Modelling delays in pharmacokinetics

    International Nuclear Information System (INIS)

    Farooqi, Z.H.; Lambrecht, R.M.

    1990-01-01

    Linear system analysis has come to form the backbone of pharmacokinetics. Natural systems usually involve time delays, thus models incorporating them would be an order closer approximation to the real world compared to those that do not. Delays may be modelled in several ways. The approach considered in this study is to have a discrete-time delay dependent rate with the delay respresenting the duration between the entry of a drug into a compartment and its release in some form (may be as a metabolite) from the compartment. Such a delay may be because of one or more of several physiological reasons, like, formation of a reservoir, slow metabolism, or receptor binding. The mathematical structure this gives rise to is a system of delay-differential equations. Examples are given of simple one and two compartment systems with drugs like bumetanide, carbamazepine, and quinolone-caffeine interaction. In these examples generally a good fit is obtained and the suggested models form a good approximation. 21 refs., 6 figs

  1. 78 FR 12763 - Pediatric Advisory Committee; Notice of Meeting

    Science.gov (United States)

    2013-02-25

    ... (esomeprazole sodium), UROXATRAL (alfuzosin hydrochloride), and ZENPEP (pancrelipase). Also, there will be an... (albumin human), KYTRIL Injection (granisetron hydrochloride), LAMICTAL XR (lamotrigine), MENACTRA...

  2. Multi-kinetics and site-specific release of gabapentin and flurbiprofen from oral fixed-dose combination: in vitro release and in vivo food effect.

    Science.gov (United States)

    Sonvico, Fabio; Conti, Chiara; Colombo, Gaia; Buttini, Francesca; Colombo, Paolo; Bettini, Ruggero; Barchielli, Marco; Leoni, Barbara; Loprete, Luca; Rossi, Alessandra

    2017-09-28

    In this work, a fixed-dose combination of gabapentin and flurbiprofen formulated as multilayer tablets has been designed, developed and studied in vitro and in vivo. The aim was to construct a single dosage form of the two drugs, able to perform a therapeutic program involving three release kinetics and two delivery sites, i.e., immediate release of gabapentin, intra-gastric prolonged release of gabapentin and intestinal (delayed) release of flurbiprofen. An oblong three-layer tablet was manufactured having as top layer a floating hydrophilic polymeric matrix for gastric release of gabapentin, as middle layer a disintegrating formulation for immediate release of a gabapentin loading dose and as bottom layer, an uncoated hydrophilic polymeric matrix, swellable but insoluble in gastric fluids, for delayed and prolonged release of flurbiprofen in intestinal environment. The formulations were studied in vitro and in vivo in healthy volunteers. The in vitro release rate assessment confirmed the programmed delivery design. A significant higher bioavailability of gabapentin administered 30min after meal, compared to fasting conditions or to dose administration 10min before meal, argued in favor of the gastro-retention of gabapentin prolonged release layer. The two drugs were delivered at different anatomical sites, since the food presence prolonged the gastric absorption of gabapentin from the floating layer and delayed the flurbiprofen absorption. The attainment of a successful delayed release of flurbiprofen was realized by a matrix based on a polymers' combination. The combined use of three hydrophilic polymers with different pH sensitivity provided the dosage form layer containing flurbiprofen with gastro-resistant characteristics without the use of film coating. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. RELEASE AND MUCOADHESION PROPERTIES OF DICLOFENAC MATRIX TABLETS FROM NATURAL AND SYNTHETIC POLYMER BLENDS.

    Science.gov (United States)

    Odeniyi, Michael A; Khan, Nasir H; Peh, Kok K

    2015-01-01

    The delayed release and mucoadhesive properties of Cedrela gum and hydroxypropylmethylcellulose blend in diclofenac sodium tablet formulations were evaluated. Tablets were prepared by direct compression and the crushing strength and detachment force were found to increase from 74.49 ± 1.22 to 147.25 ± 2.57 N and 0.302 ± 0.36 to 1.141 ± 0.05 N from low to high level of polymers, respectively. The release kinetics followed Korsmeyer-Peppas release and the n varied between 0.834 and 1.273, indicating that the release mechanism shifts from Fickian to super case I (anomalous release). The drug release profile fits a pulsatile-release pattern characterized by a lag time followed by a more or less rapid and complete drug release. The Cedrela gum-hydroxypropylmethylcelluse blend tablets delayed diclofenac release for 2 h and sustained the release for 12 h. The polymer blend delayed drug release in the 0.1 M HCl simulating gastric environment and subsequent release pH 6.8 phosphate buffer.

  4. A tandem queue with delayed server release

    OpenAIRE

    Nawijn, W.M.

    1997-01-01

    We consider a tandem queue with two stations. The rst station is an s-server queue with Poisson arrivals and exponential service times. After terminating his service in the rst station, a customer enters the second station to require service at an exponential single server, while in the meantime he is blocking his server in station 1 until he completes service in station 2, whereupon the server in station 1 is released. An analysis of the generating function of the simultaneous probability di...

  5. FAKTOR-FAKTOR YANG MEMPENGARUHI AUDIT DELAY PADA PERUSAHAAN-PERUSAHAAN GO PUBLIC DI BEJ

    Directory of Open Access Journals (Sweden)

    Reni Yendrawati

    2017-03-01

    Full Text Available Timeliness represented a very important matter in determining financial statementvalue. This research was purposed to investigate the influence of audit delay factors, namelycompany size, company that announced loss, level of company profitability, auditor’s opinionand industrial sector. Audit delay could affect the timeliness of accounting information releases,and it would be known that timeliness was associated with the market reaction to theinformation released. Sampels were selected by method of purposive sampling. Regressionanalysis was used to investigate audit delay factors. The results could be interpreted thataudit delays tended to be longer for the company that announced loss in non-manufacture’ssampel, auditor’s opinion in overall sampel and auditor’s opinion in non-manufacture’s sampel.

  6. Delayed Effects of Remote Limb Ischemic Preconditioning on Maximum Oxygen Consumption, Lactate Release and Pulmonary Function Tests in Athletes and non-Athletes

    Directory of Open Access Journals (Sweden)

    Mahnaz Momeni

    2016-11-01

    Full Text Available Background: Remote Ischemic Preconditioning (RIPC improves exercise performance, and since this phenomenon has two phases, the aim of the current study was to investigate the delayed effects of remote ischemic preconditioning on cardiopulmonary function in athletes and non-athletes. Materials and Methods: 25 male and female students were studied in two main athletes and non-athletes groups. RIPC was induced by using 3 cycles of alternative 5 minutes ischemia and 5 minutes reperfusion at arms of participants. Cardiopulmonary tests were measured before, after and 24 hours after inducing remote ischemic preconditioning. Maximum oxygen consumption (VO2max estimated by using queen steps test. Results: Analysis of data demonstrated that delayed RIPC in non-athletes group caused significant improvement in Forced Expiratory Volume in one second (FEV1 and Maximum Voluntary Ventilation (MVV and noticeable improvement in some other parameters of pulmonary function tests. Moreover, it decreased systolic blood pressure and heart rate and decreased lactate release in both groups especially athletes group but it had no significant effect on VO2max of both groups. Conclusion: Delayed RIPC improves cardiovascular function of athletes and pulmonary function of non-athletes subjects. Thus, it can be considered as a good replacement for doping to improve sports performance of subjects in sports tournaments.

  7. Extinction and permanence in delayed stage-structure predator-prey system with impulsive effects

    International Nuclear Information System (INIS)

    Pang Guoping; Wang Fengyan; Chen Lansun

    2009-01-01

    Based on the classical stage-structured model and Lotka-Volterra predator-prey model, an impulsive delayed differential equation to model the process of periodically releasing natural enemies at fixed times for pest control is proposed and investigated. We show that the conditions for global attractivity of the 'pest-extinction' ('prey-eradication') periodic solution and permanence of the population of the model depend on time delay. We also show that constant maturation time delay and impulsive releasing for the predator can bring great effects on the dynamics of system by numerical analysis. As a result, the pest maturation time delay is considered to establish a procedure to maintain the pests at an acceptably low level in the long term. In this paper, the main feature is that we introduce time delay and pulse into the predator-prey (natural enemy-pest) model with age structure, exhibit a new modelling method which is applied to investigate impulsive delay differential equations, and give some reasonable suggestions for pest management.

  8. Photoresponsive Release from Azobenzene-Modified Single Cubic Crystal NaCl/Silica Particles

    Directory of Open Access Journals (Sweden)

    Xingmao Jiang

    2011-01-01

    Full Text Available Azobenzene ligands were uniformly anchored to the pore surfaces of nanoporous silica particles with single crystal NaCl using 4-(3-triethoxysilylpropylureidoazobenzene (TSUA. The functionalization delayed the release of NaCl significantly. The modified particles demonstrated a photocontrolled release by trans/cis isomerization of azobenzene moieties. The addition of amphiphilic solvents, propylene glycol (PG, propylene glycol propyl ether (PGPE, and dipropylene glycol propyl ether (DPGPE delayed the release in water, although the wetting behavior was improved and the delay is the most for the block molecules with the longest carbon chain. The speedup by UV irradiation suggests a strong dependence of diffusion on the switchable pore size. TGA, XRD, FTIR, and NMR techniques were used to characterize the structures.

  9. Immediate versus delayed insertion of an etonogestrel releasing implant at medical abortion-a randomized controlled equivalence trial.

    Science.gov (United States)

    Hognert, Helena; Kopp Kallner, Helena; Cameron, Sharon; Nyrelli, Christina; Jawad, Izabella; Heller, Rebecca; Aronsson, Annette; Lindh, Ingela; Benson, Lina; Gemzell-Danielsson, Kristina

    2016-11-01

    Does a progestin releasing subdermal contraceptive implant affect the efficacy of medical abortion if inserted at the same visit as the progesterone receptor modulator, mifepristone, at medical abortion? A etonogestrel releasing subdermal implant inserted on the day of mifepristone did not impair the efficacy of the medical abortion compared with routine insertion at 2-4 weeks after the abortion. The etonogestrel releasing subdermal implant is one of the most effective long acting reversible contraceptive methods. The effect of timing of placement on the efficacy of mifepristone and impact on prevention of subsequent unintended pregnancy is not known. This multicentre, randomized controlled, equivalence trial with recruitment between 13 October 2013 and 17 October 2015 included a total of 551 women with pregnancies below 64 days gestation opting for the etonogestrel releasing subdermal implant as postabortion contraception. Women were randomized to either insertion at 1 hour after mifepristone intake (immediate) or at follow-up 2-4 weeks later (delayed insertion). An equivalence design was used due to advantages for women such as fewer visits to the clinic with immediate insertion. The primary outcome was the percentage of women with complete abortion not requiring surgical intervention within 1 month. Secondary outcomes included insertion rates, pregnancy and repeat abortion rates during 6 months follow-up. Analysis was per protocol and by intention to treat. Women aged 18 years and older who had requested medical termination of a pregnancy up to 63 days of gestation and opted for an etonogestrel releasing contraceptive implant were recruited in outpatient family planning clinics in six hospitals in Sweden and Scotland. Efficacy of medical abortion was 259/275 (94.2%) in the immediate insertion group and 239/249 (96%) in the routine insertion group with a risk difference of 1.8% (95% CI -0.4 to 4.1%), which was within the ±5% margin of equivalence. The insertion

  10. An oral multiparticulate, modified-release, hydrocortisone replacement therapy that provides physiological cortisol exposure.

    Science.gov (United States)

    Whitaker, Martin; Debono, Miguel; Huatan, Hiep; Merke, Deborah; Arlt, Wiebke; Ross, Richard J

    2014-04-01

    It is not possible with current hydrocortisone replacement to mimic the diurnal cortisol profile in patients with adrenal insufficiency. Previous attempts with modified-release technology were unsuccessful. Our objective was to develop hydrocortisone formulations that recreate the diurnal cortisol profile using multiparticulate technology. Screening by in vitro dissolution profiles, pharmacokinetic (PK) testing in dexamethasone-suppressed dogs and humans, and comparison with a reference population. Field laboratories and clinical research facility. Formulations were generated using an enteric (delayed release) design configuration with an extended (sustained release) dissolution profile. In vitro dissolution confirmed delayed and sustained hydrocortisone release. However, in dogs and humans, sustained release resulted in reduced bioavailability. A formulation, DIURF-006, was developed that maintained delayed release but omitted the sustained-release functionality. PK characterization of DIURF-006 showed that, despite absence of a sustained-release component, absorption was sufficiently sustained to deliver extended hydrocortisone absorption. In dexamethasone-suppressed volunteers (n = 16) receiving a twice-daily 'toothbrush' regimen (20 mg at 23:00 h and 10 mg at 07:00 h), DIURF-006 gave a similar cortisol profile to physiological cortisol levels: DIURF-006 vs physiological, Geomean AUC 5610 vs 4706 h * nmol/l, Geomean Cmax 665 vs 594 nmol/l and Median Tmax 8·5 h vs clock time 08:12 h for peak cortisol. The relative bioavailability of DIURF-006 vs hydrocortisone was 89%, and cortisol levels increased linearly with doses between 5 and 30 mg. A multiparticulate oral hydrocortisone formulation with only an enteric coat provides delayed and sustained absorption and when given in a 'toothbrush' regimen provides physiological cortisol exposure. © 2013 John Wiley & Sons Ltd.

  11. Effect of axial diffusional delays on the overall fission gas release

    International Nuclear Information System (INIS)

    Pedersen, N.K.

    1983-01-01

    In fission gas release modeling, it is normally assumed that any locally released gas mixes instantly and perfectly with other gases throughout the internal rod void volume. The present work investigates the consequences of the assumption that perfect mixing is dependent on diffusion, although the subassumption is maintained that pressure equilibrium is instantly achieved. In other words, when a burst of gas release occurs at any axial location, sufficient local accommodation takes place throughout the rod to eliminate any pressure gradients, but due to the narrowness of the passages through fuel cracks and fuel-cladding gap, concentration gradients may still prevail. Diffusion coefficients for the subsequent concentration equilibration are derived from classical theories. Application of one-dimensional diffusion theory is straightforward, but the lack of knowledge of the effective width of the axial passage introduces an uncertainty

  12. An oral multi-particulate, modified release, hydrocortisone replacement therapy that provides physiological cortisol exposure

    Science.gov (United States)

    Huatan, Hiep; Merke, Deborah; Arlt, Wiebke; Ross, Richard J.

    2013-01-01

    Objective It is not possible with current hydrocortisone replacement to mimic the diurnal cortisol profile in patients with adrenal insufficiency. Previous attempts with modified release technology were unsuccessful. Our objective was to develop hydrocortisone formulations that recreate the diurnal cortisol profile using multi-particulate technology. Design and Measurements Screening by in-vitro dissolution profiles, pharmacokinetic testing in dexamethasone suppressed dogs and humans, and comparison to a reference population. Setting Field laboratories and clinical research facility. Results Formulations were generated using an enteric (delayed-release) design configuration with an extended (sustained-release) dissolution profile. In-vitro dissolution confirmed delayed and sustained hydrocortisone release. However, in dogs and humans, sustained release resulted in reduced bioavailability. A formulation, DIURF-006, was developed that maintained delayed release but omitted the sustained release functionality. Pharmacokinetic characterisation of DIURF-006 showed that, despite absence of a sustained release component, absorption was sufficiently sustained to deliver extended hydrocortisone absorption. In dexamethasone-suppressed volunteers (n=16) receiving a twice daily ‘toothbrush’ regimen (20mg at 23:00h and 10mg at 07:00h), DIURF-006 gave a similar cortisol profile to physiological cortisol levels: DIURF-006 vs physiological, Geomean AUC 5610 vs 4706 hr*nmol/l, Geomean Cmax 665 vs 594 nmol/l and Median Tmax 8.5h vs clock time 08:12 hours for peak cortisol. The relative bioavailability of DIURF-006 vs hydrocortisone was 89% and cortisol levels increased linearly with doses between 5 and 30mg. Conclusion A multi-particulate oral hydrocortisone formulation with only an enteric coat provides delayed and sustained absorption and when given in a ‘toothbrush’ regimen provides physiological cortisol exposure. PMID:23980724

  13. alpha-difluoromethylornithine modifies gonadotropin-releasing hormone release and follicle-stimulating hormone secretion in the immature female rat.

    Science.gov (United States)

    Thyssen, S M; Becú-Villalobos, D; Lacau-Mengido, I M; Libertun, C

    1997-06-01

    Polyamines play an essential role in tissue growth and differentiation, in body weight increment, in brain organization, and in the molecular mechanisms of hormonal action, intracellular signaling, and cell-to-cell communication. In a previous study, inhibition of their synthesis by alpha-difluoromethylornithine (DFMO), a specific and irreversible inhibitor of ornithine decarboxylase, during development in female rats, was followed by prolonged high follicle-stimulating hormone (FSH) serum level and a delayed puberty onset. Those changes were relatively independent of body mass and did not impair posterior fertility. The present work studies the mechanisms and site of action of polyamine participation in FSH secretion during development. DFMO was injected in female rats between Days 1 and 9 on alternate days. At 10 days of age, hypothalami from control and DFMO rats were perifused in vitro, and basal and potassium-induced gonadotropin-releasing hormone (GnRH) release were measured. The response to membrane depolarization was altered in DFMO hypothalami. Increased GnRH release in response to a low K+ concentration was evidenced. Adenohypophyses of the same treated prepubertal rats were perifused in vitro and the response to GnRH pulses was checked. In DFMO-treated rats, higher FSH release was observed, with no changes in LH or PRL secretion. Finally, pituitary GnRH receptor number in adenohypophyseal membranes from treated and control groups was quantified. A significant reduction in specific binding was evident in hypophyses from DFMO-treated rats when compared with binding in the control group. In summary, DFMO treatment in a critical developmental period in the female rat impacts the immature GnRH neuronal network and immature gonadotropes. A delay in maturation is evidenced by a higher sensitivity to secretagogs in both pituitary glands and hypothalamic explants. These events could explain the prolonged high FSH serum levels and delayed puberty onset seen in

  14. Nuclide release from the near-field of a L/ILW repository

    International Nuclear Information System (INIS)

    Karlsson, L.G.; Hoeglund, L.O.; Pers, K.

    1986-12-01

    For Project Gewaehr 1985, the release of nuclides from a repository for low- and intermediate-level radioactive waste is calculated. The calculations are made for a reference design repository located in the marl host rock at the Oberbauen Stock reference site. The results are limited to the release of the nuclides from the waste through the engineered barriers into the surrounding host rock and will, therefore, constitute a source term for the far-field and biosphere calculations. The most probable nuclide transport mechanism is diffusion and releases are thus influenced by the nuclide diffusivities in the barriers, nuclide sorption and nuclide solubility limits. Degradation of the engineered concrete barriers is taken into account. The effects of convective flow through the barriers are described elsewhere. A near-field release model is presented. It consists of a set of computer programs suited to handel different repository designs, solubility limitations and the different waste categories. The release calculations were made for a base case in which best estimates of the parameters were used. Sensitivity to the choice of the most important parameters was tested by parameter variations. The numerical models used were checked by comparative calculations with different codes and similar data. The results of the base calculations show that near-field barriers will cause both a delay of the release to the far-field and a reduced rate of release. The sorbed nuclides, comprising the actinides and some activation and fission products, will be delayed by 10'000 years and have a maximum release rate of less than 10 -3 Ci/a each. The non-sorbed nuclides are delayed by only about 100 years and the maximum release rate is less than 10 -2 Ci per year and nuclide. The parameter variations and the design model tests gave only limited deviations from the base case results. (author)

  15. Delay in solar energetic particle onsets at high heliographic latitudes

    Directory of Open Access Journals (Sweden)

    S. Dalla

    2003-06-01

    Full Text Available Ulysses observations have shown that solar energetic particles (SEPs can easily reach high heliographic latitudes. To obtain information on the release and propagation of SEPs prior to their arrival at Ulysses, we analyse the onsets of nine large high-latitude particle events. We measure the onset times in several energy channels, and plot them versus inverse particle speed. This allows us to derive an experimental path length and time of release from the solar atmosphere. We repeat the procedure for near-Earth observations by Wind and SOHO. We find that the derived path lengths at Ulysses are 1.06 to 2.45 times the length of a Parker spiral magnetic field line connecting the spacecraft to the Sun. The time of particle release from the Sun is between 100 and 350 min later than the release time derived from in-ecliptic measurements. We find no evidence of correlation between the delay in release and the inverse of the speed of the CME associated with the event, or the inverse of the speed of the corresponding interplanetary shock. The main parameter determining the magnitude of the delay appears to be the difference in latitude between the flare and the footpoint of the spacecraft.Key words. Interplanetary physics (energetic particles – Solar physics, astrophysics and astronomy (energetic particles, flares and mass ejections

  16. Slow-release Permanganate Gel (SRP-G) for Groundwater Remediation: Spreading, Gelation, and Release in Porous and Low-Permeability Media

    Science.gov (United States)

    Lee, E. S.; Hastings, J.; Kim, Y.

    2015-12-01

    Dense nonaqueous phase liquids (DNAPLs) like trichloroethylene (TCE) serve as the most common form of groundwater pollution in the world. Pore-plugging by the solid oxidation product MnO2 and limited lateral dispersion of the oxidant are two common problems with existing in-situ chemical oxidation (ISCO) schemes that could be alleviated through the development of a delayed gelation method for oxidant delivery. The objective of the current study was to further develop and optimize slow-release permanganate gel (SRP-G), a solution comprising colloidal silica and KMnO4, as a novel low-cost treatment option for large and dilute TCE plumes in groundwater. Batch tests showed that gelation could be delayed through manipulation of KMnO4 concentration, pH, and silica particle size of the SRP-G solution. In flow-through columns and flow-tanks filled with saturated sands, silica concentration had little effect on the gelation lag stage and release rate, but increasing silica concentration was associated with increasing release duration. When compared to a pure KMnO4 solution, visual observations and [MnO4-] measurements from flow tank tests demonstrated that the SRP-G prolonged the release duration and enhanced lateral spreading of the oxidant.

  17. Online Scheduling in Manufacturing A Cumulative Delay Approach

    CERN Document Server

    Suwa, Haruhiko

    2013-01-01

    Online scheduling is recognized as the crucial decision-making process of production control at a phase of “being in production" according to the released shop floor schedule. Online scheduling can be also considered as one of key enablers to realize prompt capable-to-promise as well as available-to-promise to customers along with reducing production lead times under recent globalized competitive markets. Online Scheduling in Manufacturing introduces new approaches to online scheduling based on a concept of cumulative delay. The cumulative delay is regarded as consolidated information of uncertainties under a dynamic environment in manufacturing and can be collected constantly without much effort at any points in time during a schedule execution. In this approach, the cumulative delay of the schedule has the important role of a criterion for making a decision whether or not a schedule revision is carried out. The cumulative delay approach to trigger schedule revisions has the following capabilities for the ...

  18. Analysis of Delayed Sea Breeze Onset for Fort Ord Prescribed Burning Operations

    Science.gov (United States)

    2015-12-01

    DELAYED SEA BREEZE ONSET FOR FORT ORD PRESCRIBED BURNING OPERATIONS by Dustin D. Hocking December 2015 Thesis Advisor: Wendell Nuss Second...AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE ANALYSIS OF DELAYED SEA BREEZE ONSET FOR FORT ORD PRESCRIBED BURNING OPERATIONS 5...release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) The U.S. Army conducts prescribed burns at Fort Ord

  19. Carbonate fuel cell and components thereof for in-situ delayed addition of carbonate electrolyte

    Science.gov (United States)

    Johnsen, Richard [Waterbury, CT; Yuh, Chao-Yi [New Milford, CT; Farooque, Mohammad [Danbury, CT

    2011-05-10

    An apparatus and method in which a delayed carbonate electrolyte is stored in the storage areas of a non-electrolyte matrix fuel cell component and is of a preselected content so as to obtain a delayed time release of the electrolyte in the storage areas in the operating temperature range of the fuel cell.

  20. Rapid versus delayed stimulation of feeding by the endogenously released AgRP neuron mediators GABA, NPY, and AgRP.

    Science.gov (United States)

    Krashes, Michael J; Shah, Bhavik P; Koda, Shuichi; Lowell, Bradford B

    2013-10-01

    Agouti-related peptide (AgRP) neurons of the hypothalamus release a fast transmitter (GABA) in addition to neuropeptides (neuropeptide Y [NPY] and Agouti-related peptide [AgRP]). This raises questions as to their respective functions. The acute activation of AgRP neurons robustly promotes food intake, while central injections of AgRP, NPY, or GABA agonist results in the marked escalation of food consumption with temporal variance. Given the orexigenic capability of all three of these neuroactive substances in conjunction with their coexpression in AgRP neurons, we looked to unravel their relative temporal role in driving food intake. After the acute stimulation of AgRP neurons with DREADD technology, we found that either GABA or NPY is required for the rapid stimulation of feeding, and the neuropeptide AgRP, through action on MC4 receptors, is sufficient to induce feeding over a delayed yet prolonged period. These studies help to elucidate the neurochemical mechanisms of AgRP neurons in controlling temporally distinct phases of eating. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. On the synchronization of neural networks containing time-varying delays and sector nonlinearity

    International Nuclear Information System (INIS)

    Yan, J.-J.; Lin, J.-S.; Hung, M.-L.; Liao, T.-L.

    2007-01-01

    We present a systematic design procedure for synchronization of neural networks subject to time-varying delays and sector nonlinearity in the control input. Based on the drive-response concept and the Lyapunov stability theorem, a memoryless decentralized control law is proposed which guarantees exponential synchronization even when input nonlinearity is present. The supplementary requirement that the time-derivative of time-varying delays must be smaller than one is released for the proposed control scheme. A four-dimensional Hopfield neural network with time-varying delays is presented as the illustrative example to demonstrate the effectiveness of the proposed synchronization scheme

  2. LOFC fission product release and circulating activity calculations for gas-cooled reactors

    International Nuclear Information System (INIS)

    Apperson, C.E. Jr.; Carruthers, L.M.; Lee, C.E.

    1977-01-01

    The inventories of fission products in a gas-cooled reactor under accident and normal steady state conditions are time and temperature dependent. To obtain a reasonable estimate of these inventories it is necessary to consider fuel failure, a temperature dependent variable, and radioactive decay, a time dependent variable. Using arbitrary radioactive decay chains and published fuel failure models for the High Temperature Gas-Cooled Reactor (HTGR), methods have been developed to evaluate the release of fission products during the Loss of Forced Circulation (LOFC) accident and the circulating and plateout fission product inventories during steady state non-accident operation. The LARC-2 model presented here neglects the time delays in the release from the HTGR due to diffusion of fission products from particles in the fuel rod through the graphite matrix. It also neglects the adsorption and evaporation process of metallics at the fuel rod-graphite and graphite-coolant hole interfaces. Any time delay due to the finite time of transport of fission products by convection through the coolant to the outside of the prestressed concrete reactor vessel (PCRV) is also neglected. This model assumes that all fission products released from fuel particles are immediately deposited outside the PCRV with no time delay

  3. Granisetron Extended-Release Injection: A Review in Chemotherapy-Induced Nausea and Vomiting.

    Science.gov (United States)

    Deeks, Emma D

    2016-12-01

    An extended-release (ER) subcutaneously injectable formulation of the first-generation 5-HT 3 receptor antagonist granisetron is now available in the USA (Sustol ® ), where it is indicated for the prevention of acute and delayed chemotherapy-induced nausea and vomiting (CINV) following moderately emetogenic chemotherapy (MEC) or anthracycline and cyclophosphamide combination chemotherapy regimens in adults. Granisetron ER is administered as a single subcutaneous injection and uses an erosion-controlled drug-delivery system to allow prolonged granisetron release. Primary endpoint data from phase III studies after an initial cycle of chemotherapy indicate that, when used as part of an antiemetic regimen, granisetron ER injection is more effective than intravenous ondansetron in preventing delayed CINV following highly emetogenic chemotherapy (HEC); is noninferior to intravenous palonosetron in preventing both acute CINV following MEC or HEC and delayed CINV following MEC; and is similar, but not superior, to palonosetron in preventing delayed CINV following HEC. The benefits of granisetron ER were seen in various patient subgroups, including those receiving anthracycline plus cyclophosphamide-based HEC, and (in an extension of one of the studies) over multiple MEC or HEC cycles. Granisetron ER injection is generally well tolerated, with an adverse event profile similar to that of ondansetron or palonosetron. Thus, granisetron ER injection expands the options for preventing both acute and delayed CINV in adults with cancer receiving MEC or anthracycline plus cyclophosphamide-based HEC.

  4. Inhibition of Mitochondrial Cytochrome c Release and Suppression of Caspases by Gamma-Tocotrienol Prevent Apoptosis and Delay Aging in Stress-Induced Premature Senescence of Skin Fibroblasts

    Directory of Open Access Journals (Sweden)

    Suzana Makpol

    2012-01-01

    Full Text Available In this study, we determined the molecular mechanism of γ-tocotrienol (GTT in preventing cellular aging by focusing on its anti-apoptotic effect in stress-induced premature senescence (SIPS model of human diploid fibroblasts (HDFs. Results obtained showed that SIPS exhibited senescent-phenotypic characteristic, increased expression of senescence-associated β-galactosidase (SA β-gal and promoted G0/G1 cell cycle arrest accompanied by shortening of telomere length with decreased telomerase activity. Both SIPS and senescent HDFs shared similar apoptotic changes such as increased Annexin V-FITC positive cells, increased cytochrome c release and increased activation of caspase-9 and caspase-3 (P<0.05. GTT treatment resulted in a significant reduction of Annexin V-FITC positive cells, inhibited cytochrome c release and decreased activation of caspase-9 and caspase-3 (P<0.05. Gene expression analysis showed that GTT treatment down regulated BAX mRNA, up-regulated BCL2A1 mRNA and decreased the ratio of Bax/Bcl-2 protein expression (P<0.05 in SIPS. These findings suggested that GTT inhibits apoptosis by modulating the upstream apoptosis cascade, causing the inhibition of cytochrome c release from the mitochondria with concomitant suppression of caspase-9 and caspase-3 activation. In conclusion, GTT delays cellular senescence of human diploid fibroblasts through the inhibition of intrinsic mitochondria-mediated pathway which involved the regulation of pro- and anti-apoptotic genes and proteins.

  5. Gastrin-releasing peptide is a transmitter mediating porcine gallbladder contraction

    DEFF Research Database (Denmark)

    Schjoldager, Birgit; Poulsen, S.S.; Schmidt, P.

    1991-01-01

    We studied the role of gastrin-releasing peptide (GRP) for porcine gallbladder motility. Immunohistochemistry visualized nerve fibers containing GRP-like immunoreactivity in muscularis. GRP concentration dependently stimulated contractions of muscularis strips (ED50, 2.9 nM). Neuromedin B was les......-like immunoreactivity. Thus two neural inputs were defined: a cholinergic rapid onset-rapid offset excitation and a delayed, slow onset-slow offset excitation caused by release and subsequent binding of GRP to GRP-preferring receptors....

  6. The application and evaluation of insulin release test and quantitative parameter in diabetic type II

    International Nuclear Information System (INIS)

    Huang Chenggang; Chen Xiaoyan; Guan Xiaofeng

    2002-01-01

    Objective: To analyse the curve of Insulin Release Test (IRT) about the patients whit type II diabetes, to evaluate β-cell function and the sensitivity of body to Insulin using Insulin Release Index (IRI) and Insulin Sensitivity Index (ISI), and to probe the value for clinical therapy. Methods: 1) Have a IRT of 396 cases with type II diabetes and 17 normal bodies and acquire the IRT curve, 2) Design the count methods about IRI and ISI, IRI = Ins max/Ins FBI x Δ Ins max/T max (minute), ISI=(Ins max-Ins FBI)/(Ins 180'-Ins FBI), 3) Compare IRI Changes of before and after treatment for 12 cases with no insulin release and 9 cases with less insulin release. Results: IRT curve type (No release type 21.0%, less release type 33.3%, peak delay type 36.9%, high insulin type 6.0%, release delay type 2.8%); respective IRI, ISI compared to normal, P<0.01; IRI of before and after treatment with insulin P<0.01. Conclusions: IRT Curve combining IRI and ISI can reflect accurately β-cell function with type II diabetes and the sensitivity of body to insulin, Also it has some reference value for clinical therapy

  7. Modeling delay in genetic networks: from delay birth-death processes to delay stochastic differential equations.

    Science.gov (United States)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Bennett, Matthew R; Josić, Krešimir; Ott, William

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  8. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Bennett, Matthew R. [Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77204, USA and Institute of Biosciences and Bioengineering, Rice University, Houston, Texas 77005 (United States); Josić, Krešimir [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204 (United States)

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  9. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    International Nuclear Information System (INIS)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William; Bennett, Matthew R.; Josić, Krešimir

    2014-01-01

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay

  10. A Phase 1 Pharmacokinetic Study of Cysteamine Bitartrate Delayed-Release Capsules Following Oral Administration with Orange Juice, Water, or Omeprazole in Cystinosis.

    Science.gov (United States)

    Armas, Danielle; Holt, Robert J; Confer, Nils F; Checani, Gregg C; Obaidi, Mohammad; Xie, Yuli; Brannagan, Meg

    2018-02-01

    Cystinosis is a rare, metabolic, autosomal recessive, genetic lysosomal storage disorder characterized by an accumulation of cystine in various organs and tissues. Cysteamine bitartrate (CB) is a cystine-depleting aminothiol agent approved in the United States and Europe in immediate-release and delayed-release (DR) formulations for the treatment of nephropathic cystinosis in children and adults. It is recommended that CBDR be administered with fruit juice (except grapefruit juice) for maximum absorption. Omeprazole is a proton pump inhibitor that inhibits gastric acid secretion and, theoretically, may cause the premature release of cysteamine by increasing intragastric pH, thereby affecting the PK of CBDR. This open-label, three-period, randomized study in healthy adult subjects was designed primarily to compare the pharmacokinetics of CBDR capsules after a single oral dose administered with orange juice, water, or multiple oral doses of omeprazole with water at steady state. A total of 32 subjects were randomly assigned to receive study agents in one of two treatment sequences. All subjects completed the study and baseline characteristics of the overall population and the two treatment sequence populations were similar. Peak mean plasma cysteamine concentrations following co-administration of CBDR capsules with orange juice (1892 ng/mL) were higher compared with co-administration with water (1663 ng/mL) or omeprazole 20 mg and water (1712 ng/mL). Mean time to peak plasma concentration was shorter with omeprazole co-administration (2.5 h) compared with orange juice (3.5 h) or water (3.0 h). Statistical comparisons between treatment groups indicated that exposure as assessed by AUC 0-t , AUC 0-∞ , and C max were all within the 80-125% bioequivalence ranges for all comparisons. All treatments were generally well tolerated. Overall, the pharmacokinetics of cysteamine bitartrate DR capsules are not significantly impacted by co-administration with orange juice

  11. Simplified method for measuring the response time of scram release electromagnet in a nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Patri, Sudheer, E-mail: patri@igcar.gov.in; Mohana, M.; Kameswari, K.; Kumar, S. Suresh; Narmadha, S.; Vijayshree, R.; Meikandamurthy, C.; Venkatesan, A.; Palanisami, K.; Murthy, D. Thirugnana; Babu, B.; Prakash, V.; Rajan, K.K.

    2015-04-15

    Highlights: • An alternative method for estimating the electromagnet clutch release time. • A systematic approach to develop a computer based measuring system. • Prototype tests on the measurement system. • Accuracy of the method is ±6% and repeatability error is within 2%. - Abstract: The delay time in electromagnet clutch release during a reactor trip (scram action) is an important safety parameter, having a bearing on the plant safety during various design basis events. Generally, it is measured using current decay characteristics of electromagnet coil and its energising circuit. A simplified method of measuring the same in a Sodium cooled fast reactors (SFR) is proposed in this paper. The method utilises the position data of control rod to estimate the delay time in electromagnet clutch release. A computer based real time measurement system for measuring the electromagnet clutch delay time is developed and qualified for retrofitting in prototype fast breeder reactor. Various stages involved in the development of the system are principle demonstration, experimental verification of hardware capabilities and prototype system testing. Tests on prototype system have demonstrated the satisfactory performance of the system with intended accuracy and repeatability.

  12. Controlled Release Formulations of Auxinic Herbicides

    Science.gov (United States)

    Kowalski, Witold J.; Siłowiecki, Andrzej.; Romanowska, Iwona; Glazek, Mariola; Bajor, Justyna; Cieciwa, Katarzyna; Rychter, Piotr

    2013-04-01

    Controlled release formulations are applied extensively for the release of active ingredients such as plant protection agents and fertilizers in response to growing concern for ecological problems associated with increased use of plant protection chemicals required for intensive agricultural practices [1]. We synthesized oligomeric mixtures of (R,S)-3-hydroxy butyric acid chemically bonded with 2,4-D, Dicamba and MCPA herbicides (HBA) respectively, and determined their molecular structure and molecular weight dispersion by the size exclusion chromatography, proton magnetic resonance spectrometry and electro-spray ionization mass spectrometry. Further we carried out bioassays of herbicidal effectiveness of the HBA herbicides vs. series of dicotyledonous weeds and crop injury tests [2, 3, 4]. Field bioassays were accomplished according to the EPPO standards [5]. Groups of representative weeds (the development stages in the BCCH scale: 10 - 30) were selected as targets. Statistical variabilities were assessed by the Fisher LSD test for plants treated with the studied herbicides in form of HBA oligomers, the reference herbicides in form of dimethyl ammonium salts (DMA), and untreated plants. No statistically significant differences in the crop injuries caused by the HBA vs. the DMA reference formulation were observed. The effectiveness of the HBA herbicides was lower through the initial period (ca. 2 weeks) relative to the DMA salts, but a significant increase in the effectiveness of the HBA systems followed during the remaining fraction of each assay. After 6 weeks all observed efficiencies approached 100%. The death of weeds treated with the HBA herbicides was delayed when compared with the DMA reference herbicides. The delayed uptake observed for the HBA oligomers relative to the DMA salts was due to controlled release phenomena. In case of the DMA salts the total amount of active ingredients was available at the target site. By contrast, the amount of an active

  13. A COLD FLARE WITH DELAYED HEATING

    International Nuclear Information System (INIS)

    Fleishman, Gregory D.; Pal'shin, Valentin D.; Lysenko, Alexandra L.; Meshalkina, Natalia; Kashapova, Larisa K.; Altyntsev, Alexander T.

    2016-01-01

    Recently, a number of peculiar flares have been reported that demonstrate significant nonthermal particle signatures with low, if any, thermal emission, which implies a close association of the observed emission with the primary energy release/electron acceleration region. This paper presents a flare that appears “cold” at the impulsive phase, while displaying delayed heating later on. Using hard X-ray data from Konus- Wind , microwave observations by SSRT, RSTN, NoRH, and NoRP, context observations, and three-dimensional modeling, we study the energy release, particle acceleration, and transport, and the relationships between the nonthermal and thermal signatures. The flaring process is found to involve the interaction between a small loop and a big loop with the accelerated particles divided roughly equally between them. Precipitation of the electrons from the small loop produced only a weak thermal response because the loop volume was small, while the electrons trapped in the big loop lost most of their energy in the coronal part of the loop, which resulted in coronal plasma heating but no or only weak chromospheric evaporation, and thus unusually weak soft X-ray emission. The energy losses of the fast electrons in the big tenuous loop were slow, which resulted in the observed delay of the plasma heating. We determined that the impulsively accelerated electron population had a beamed angular distribution in the direction of the electric force along the magnetic field of the small loop. The accelerated particle transport in the big loop was primarily mediated by turbulent waves, which is similar to other reported cold flares.

  14. Assessing the influence of media composition and ionic strength on drug release from commercial immediate-release and enteric-coated aspirin tablets.

    Science.gov (United States)

    Karkossa, Frank; Klein, Sandra

    2017-10-01

    The objective of this test series was to elucidate the importance of selecting the right media composition for a biopredictive in-vitro dissolution screening of enteric-coated dosage forms. Drug release from immediate-release (IR) and enteric-coated (EC) aspirin formulations was assessed in phosphate-based and bicarbonate-based media with different pH, electrolyte composition and ionic strength. Drug release from aspirin IR tablets was unaffected by media composition. In contrast, drug release from EC aspirin formulations was affected by buffer species and ionic strength. In all media, drug release increased with increasing ionic strength, but in bicarbonate-based buffers was delayed when compared with that in phosphate-based buffers. Interestingly, the cation species in the dissolution medium had also a clear impact on drug release. Drug release profiles obtained in Blank CarbSIF, a new medium simulating pH and average ionic composition of small intestinal fluid, were different from those obtained in all other buffer compositions studied. Results from this study in which the impact of various media parameters on drug release of EC aspirin formulations was systematically screened clearly show that when developing predictive dissolution tests, it is important to simulate the ionic composition of intraluminal fluids as closely as possible. © 2017 Royal Pharmaceutical Society.

  15. Optimization of ISOL targets based on Monte-Carlo simulations of ion release curves

    International Nuclear Information System (INIS)

    Mustapha, B.; Nolen, J.A.

    2003-01-01

    A detailed model for simulating release curves from ISOL targets has been developed. The full 3D geometry is implemented using Geant-4. Produced particles are followed individually from production to release. The delay time is computed event by event. All processes involved: diffusion, effusion and decay are included to obtain the overall release curve. By fitting to the experimental data, important parameters of the release process (diffusion coefficient, sticking time, ...) are extracted. They can be used to improve the efficiency of existing targets and design new ones more suitable to produce beams of rare isotopes

  16. Optimization of ISOL targets based on Monte-Carlo simulations of ion release curves

    CERN Document Server

    Mustapha, B

    2003-01-01

    A detailed model for simulating release curves from ISOL targets has been developed. The full 3D geometry is implemented using Geant-4. Produced particles are followed individually from production to release. The delay time is computed event by event. All processes involved: diffusion, effusion and decay are included to obtain the overall release curve. By fitting to the experimental data, important parameters of the release process (diffusion coefficient, sticking time, ...) are extracted. They can be used to improve the efficiency of existing targets and design new ones more suitable to produce beams of rare isotopes.

  17. Sustained release of fungicide metalaxyl by mesoporous silica nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Wanyika, Harrison, E-mail: hwanyika@gmail.com [Jomo Kenyatta University of Agriculture and Technology, Department of Chemistry (Kenya)

    2013-08-15

    The use of nanomaterials for the controlled delivery of pesticides is nascent technology that has the potential to increase the efficiency of food production and decrease pollution. In this work, the prospect of mesoporous silica nanoparticles (MSN) for storage and controlled release of metalaxyl fungicide has been investigated. Mesoporous silica nanospheres with average particle diameters of 162 nm and average pore sizes of 3.2 nm were prepared by a sol-gel process. Metalaxyl molecules were loaded into MSN pores from an aqueous solution by a rotary evaporation method. The loaded amount of metalaxyl as evaluated by thermogravimetric analysis was about 14 wt%. Release of the fungicide entrapped in the MSN matrix revealed sustained release behavior. About 76 % of the free metalaxyl was released in soil within a period of 30 days while only 11.5 and 47 % of the metalaxyl contained in the MSN carrier was released in soil and water, respectively, within the same period. The study showed that MSN can be used to successfully store metalaxyl molecules in its mesoporous framework and significantly delay their release in soil.

  18. Sustained release of fungicide metalaxyl by mesoporous silica nanospheres

    International Nuclear Information System (INIS)

    Wanyika, Harrison

    2013-01-01

    The use of nanomaterials for the controlled delivery of pesticides is nascent technology that has the potential to increase the efficiency of food production and decrease pollution. In this work, the prospect of mesoporous silica nanoparticles (MSN) for storage and controlled release of metalaxyl fungicide has been investigated. Mesoporous silica nanospheres with average particle diameters of 162 nm and average pore sizes of 3.2 nm were prepared by a sol–gel process. Metalaxyl molecules were loaded into MSN pores from an aqueous solution by a rotary evaporation method. The loaded amount of metalaxyl as evaluated by thermogravimetric analysis was about 14 wt%. Release of the fungicide entrapped in the MSN matrix revealed sustained release behavior. About 76 % of the free metalaxyl was released in soil within a period of 30 days while only 11.5 and 47 % of the metalaxyl contained in the MSN carrier was released in soil and water, respectively, within the same period. The study showed that MSN can be used to successfully store metalaxyl molecules in its mesoporous framework and significantly delay their release in soil

  19. Controlled drug release from bifunctionalized mesoporous silica

    Science.gov (United States)

    Xu, Wujun; Gao, Qiang; Xu, Yao; Wu, Dong; Sun, Yuhan; Shen, Wanling; Deng, Feng

    2008-10-01

    Serial of trimethylsilyl-carboxyl bifunctionalized SBA-15 (TMS/COOH/SBA-15) have been studied as carriers for controlled release of drug famotidine (Famo). To load Famo with large capacity, SBA-15 with high content of carboxyl groups was successfully synthesized by one-pot synthesis under the assistance of KCl. The mesostructure of carboxyl functionalized SBA-15 (COOH/SBA-15) could still be kept even though the content of carboxyl groups was up to 57.2%. Increasing carboxyl content could effectively enhance the loading capacity of Famo. Compared with pure SBA-15, into which Famo could be hardly adsorbed, the largest drug loading capacity of COOH/SBA-15 could achieve 396.9 mg/g. The release of Famo from mesoporous silica was studied in simulated intestine fluid (SIF, pH=7.4). For COOH/SBA-15, the release rate of Famo decreased with narrowing pore size. After grafting TMS groups on the surface of COOH/SBA-15 with hexamethyldisilazane, the release of Famo was greatly delayed with the increasing content of TMS groups.

  20. Bcl-2 and Bcl-xL overexpression inhibits cytochrome c release, activation of multiple caspases, and virus release following coxsackievirus B3 infection

    International Nuclear Information System (INIS)

    Carthy, Christopher M.; Yanagawa, Bobby; Luo Honglin; Granville, David J.; Yang, Decheng; Cheung, Paul; Cheung, Caroline; Esfandiarei, Mitra; Rudin, Charles M.; Thompson, Craig B.; Hunt, David W.C.; McManus, Bruce M.

    2003-01-01

    Coxsackievirus B3, a cytopathic virus in the family Picornaviridae, induces degenerative changes in host cell morphology. Here we demonstrate cytochrome c release and caspases-2, -3, -6, -7, -8, and -9 processing. Enforced Bcl-2 and Bcl-xL expression markedly reduced release of cytochrome c, presentation of the mitochondrial epitope 7A6, and depressed caspase activation following infection. In comparison, cell death using TRAIL ligand caused caspase-8 processing prior to cytochrome c release and executioner caspases and cell death was only partially rescued by Bcl-2 and Bcl-xL overexpression. Disruption of the mitochondrial inner membrane potential following CVB3 infection was not inhibited by zVAD.fmk treatment. Bcl-2 or Bcl-xL overexpression or zVAD.fmk treatment delayed the loss of host cell viability and decreased progeny virus release following infection. Our data suggest that mitochondrial release of cytochrome c may be an important early event in caspase activation in CVB3 infection, and, as such, may contribute to the loss of host-cell viability and progeny virus release

  1. Bidirectional automatic release of reserve for low voltage network made with low capacity PLCs

    Science.gov (United States)

    Popa, I.; Popa, G. N.; Diniş, C. M.; Deaconu, S. I.

    2018-01-01

    The article presents the design of a bidirectional automatic release of reserve made on two types low capacity programmable logic controllers: PS-3 from Klöckner-Moeller and Zelio from Schneider. It analyses the electronic timing circuits that can be used for making the bidirectional automatic release of reserve: time-on delay circuit and time-off delay circuit (two types). In the paper are present the sequences code for timing performed on the PS-3 PLC, the logical functions for the bidirectional automatic release of reserve, the classical control electrical diagram (with contacts, relays, and time relays), the electronic control diagram (with logical gates and timing circuits), the code (in IL language) made for the PS-3 PLC, and the code (in FBD language) made for Zelio PLC. A comparative analysis will be carried out on the use of the two types of PLC and will be present the advantages of using PLCs.

  2. Fission-energy release for 16 fissioning nuclides. Final report

    International Nuclear Information System (INIS)

    Sher, R.

    1981-03-01

    Results are presented of a least-squares evaluation of the components of energy release per fission in 232 Th, 233 U, 235 U, 238 U, 239 Pu, and 241 Pu. For completeness, older (1978) results based on systematics are presented for these and ten other isotopes of interest. There have been recent indications that the delayed energy components may be somewhat higher than those used previously, but the LSQ results do not seem to change significantly when modest (approx. 1 MeV) increases in the total delayed energy are included in the inputs. Additional measurements of most of the energy components are still needed to resolve remaining discrepancies

  3. Optimal Joint Expected Delay Forwarding in Delay Tolerant Networks

    OpenAIRE

    Jia Xu; Xin Feng; Wen Jun Yang; Ru Chuan Wang; Bing Qing Han

    2013-01-01

    Multicopy forwarding schemes have been employed in delay tolerant network (DTN) to improve the delivery delay and delivery rate. Much effort has been focused on reducing the routing cost while retaining high performance. This paper aims to provide an optimal joint expected delay forwarding (OJEDF) protocol which minimizes the expected delay while satisfying a certain constant on the number of forwardings per message. We propose a comprehensive forwarding metric called joint expected delay (JE...

  4. Estimating ionospheric delay using kriging: 2. Impact on satellite-based augmentation system availability

    Science.gov (United States)

    Sparks, Lawrence; Blanch, Juan; Pandya, Nitin

    2011-12-01

    An augmentation of the Global Positioning System, the Wide Area Augmentation System (WAAS) broadcasts, at each node of an ionospheric grid, an estimate of the vertical ionospheric delay and an integrity bound on the vertical delay error. To date, these quantities have been determined from a planar fit of slant delay measurements, projected to vertical using an obliquity factor specified by the standard thin shell model of the ionosphere. In a future WAAS upgrade (WAAS Follow-On Release 3), however, they will be calculated using an established, geo-statistical estimation technique known as kriging that generally provides higher estimate accuracy than planar fit estimation. This paper analyzes the impact of kriging on system availability. In a preliminary assessment, kriging is found to produce improvements in availability of up to 15%.

  5. Permanganate gel (PG) for groundwater remediation: compatibility, gelation, and release characteristics.

    Science.gov (United States)

    Lee, Eung Seok; Olson, Pamela R; Gupta, Neha; Solpuker, Utku; Schwartz, Franklin W; Kim, Yongje

    2014-02-01

    Permanganate (MnO4(-)) is a strong oxidant that is widely used for treating chlorinated ethylenes in groundwater. This study aims to develop hyper-saline MnO4(-) solution (MnO4(-) gel; PG) that can be injected into aquifers via wells, slowly gelates over time, and slowly release MnO4(-) to flowing water. In this study, compatibility and miscibility of gels, such as chitosan, aluminosilicate, silicate, and colloidal silica gels, with MnO4(-) were tested. Of these gels, chitosan was reactive with MnO4(-). Aluminosilicates were compatible but not readily miscible with MnO4(-). Silicates and colloidal silica were both compatible and miscible with MnO4(-), and gelated with addition of KMnO4 granules. Colloidal silica has low initial viscosity (<15cP), exhibited delayed gelation characteristics with the lag times ranging from 0 to 200min. Release of MnO4(-) from the colloidal silica-based PG gel occurred in a delayed fashion, with maximum duration of 24h. These results suggested that colloidal silica can be used to create PG or delayed-gelling forms containing other oxidants which can be used for groundwater remediation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Determination of the sterile release rate for stopping growing age-structured populations

    International Nuclear Information System (INIS)

    Barclay, Hugh John

    2016-01-01

    A freely-growing age-structured population was modelled for growth and control by sterile male releases. Equilibrium populations yield critical sterile male release rates that would hold the population at equilibrium. It is shown here that these rates may be different from the release rates required to stop a growing population and bring it to an equilibrium. A computer simulation was constructed of this population and a parameter sensitivity analysis graphed the effects on the required sterile male release rate of fertility, mating delay in adult females, net juvenile survivorship, three adult survivorship curves, the time spent in the juvenile stages, and total life span. The adult survivorship curves had the greatest effect on the required sterile release rate for population elimination. The required release rate was also determined for Ceratitis capitata (Wiedemann) using survivorship and fertility data from a laboratory strain. The concepts of over-flooding ratio and release ratio were discussed and quantified for the cases above. (author)

  7. Suppressed Release of Clarithromycin from Tablets by Crystalline Phase Transition of Metastable Polymorph Form I.

    Science.gov (United States)

    Fujiki, Sadahiro; Watanabe, Narumi; Iwao, Yasunori; Noguchi, Shuji; Mizoguchi, Midori; Iwamura, Takeru; Itai, Shigeru

    2015-08-01

    The pharmaceutical properties of clarithromycin (CAM) tablets containing the metastable form I of crystalline CAM were investigated. Although the dissolution rate of form I was higher than that of stable form II, the release of CAM from form I tablet was delayed. Disintegration test and liquid penetration test showed that the disintegration of the tablet delayed because of the slow penetration of an external solution into form I tablet. Investigation by scanning electron microscopy revealed that the surface of form I tablet was covered with fine needle-shaped crystals following an exposure to the external solution. These crystals were identified as form IV crystals by powder X-ray diffraction. The phenomenon that CAM releases from tablet was inhibited by fine crystals spontaneously formed on the tablet surface could be applied to the design of sustained-release formulation systems with high CAM contents by minimizing the amount of functional excipients. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  8. Officially released mutant varieties - the FAO/IAEA Database

    International Nuclear Information System (INIS)

    Maluszynski, M.; Nichterlein, K.; Zanten, L. van; Ahloowalia, B.S.

    2000-01-01

    In the approximately 70 year-old history of induced mutations, there are many examples on the development of new and valuable alteration in plant characters significantly contributing to increased yield potential of specific crops. However, knowledge on the success of induced mutations in crop improvement among geneticists and breeders is usually limited to species of their interest. The present paper contains a comprehensive list of officially released mutant varieties, based on information from plant breeders. The number of mutant varieties officially released and recorded in the FAO/IAEA Mutant Varieties Database before the end of 2000 is 2,252. Almost half of these varieties have been released during the last 15 years. Considering a significant delay in the dissemination of information on newly released varieties and difficulties in the collection of such data, there has been a renaissance in the use of mutation techniques in crop improvement. At the demand of geneticists, plant breeders, and more recently molecular geneticists, for information on released mutant varieties of specific crops, the MVD was transferred to the web site of the FAO/IAEA Joint Division. The MVD will be available on our web pages early in 2001. (author)

  9. Experiment of aerosol-release time for a novel automatic metered dose inhaler

    Directory of Open Access Journals (Sweden)

    Mingrong Zhang

    2016-05-01

    Full Text Available The objective of this study was to evaluate the aerosol-release time in the development of a new automatic adapter for metered dose inhaler. With this device, regular manually operated metered dose inhalers become automatic. During the study, an inhalation simulator was designed and tested with the newly developed mechatronic system. By adjusting the volume and the pressure of the vacuum tank, most human inhalation waveforms were able to simulate. As an example, regular quick-deep and slow-deep waveforms were matched within reasonable accuracy. Finally, with the help of dynamic image processing, the aerosol-release time (Tr was carefully measured and fully discussed, including the switch-on time (Ts, the mechatronics-hysteresis (Tm and the intentional-delay (Ti. Under slow-deep inhalation condition which is suitable for metered dose inhaler medicine delivery, the switch-on flow-rate could reach as low as 10 L/min, and the corresponding switch-on time was approximately 0.20 s. While the mechatronics-hysteresis depended on the brand of metered dose inhaler, assuming there was no intentional-delay, the aerosol-release time could be as low as 0.40 and 0.60 s, respectively, for two commercially available metered dose inhalers studied in this article. Therefore, this newly developed mechatronic adapter system could ensure aerosol-release time (Tr within satisfactory range for metered dose inhalers.

  10. Stability and delay sensitivity of neutral fractional-delay systems.

    Science.gov (United States)

    Xu, Qi; Shi, Min; Wang, Zaihua

    2016-08-01

    This paper generalizes the stability test method via integral estimation for integer-order neutral time-delay systems to neutral fractional-delay systems. The key step in stability test is the calculation of the number of unstable characteristic roots that is described by a definite integral over an interval from zero to a sufficient large upper limit. Algorithms for correctly estimating the upper limits of the integral are given in two concise ways, parameter dependent or independent. A special feature of the proposed method is that it judges the stability of fractional-delay systems simply by using rough integral estimation. Meanwhile, the paper shows that for some neutral fractional-delay systems, the stability is extremely sensitive to the change of time delays. Examples are given for demonstrating the proposed method as well as the delay sensitivity.

  11. Food-grade micro-encapsulation systems that may induce satiety via delayed lipolysis: A review.

    Science.gov (United States)

    Corstens, Meinou N; Berton-Carabin, Claire C; de Vries, Renko; Troost, Freddy J; Masclee, Ad A M; Schroën, Karin

    2017-07-03

    The increasing prevalence of overweight and obesity requires new, effective prevention and treatment strategies. One approach to reduce energy intake is by developing novel foods with increased satiating properties, which may be accomplished by slowing down lipolysis to deliver substrates to the ileum, thereby enhancing natural gut-brain signaling pathways of satiety that are normally induced by meal intake. To develop slow release food additives, their processing in the gastrointestinal tract has to be understood; therefore, we start from a general description of the digestive system and relate that to in vitro modeling, satiety, and lipolytic mechanisms. The effects of physicochemical lipid composition, encapsulation matrix, and interfacial structure on lipolysis are emphasized. We give an overview of techniques and materials used, and discuss partitioning, which may be a key factor for encapsulation performance. Targeted release capsules that delay lipolysis form a real challenge because of the high efficiency of the digestive system; hardly any proof was found that intact orally ingested lipids can be released in the ileum and thereby induce satiety. We expect that this challenge could be tackled with structured o/w-emulsion-based systems that have some protection against lipase, e.g., by hindering bile salt adsorption and/or delaying lipase diffusion.

  12. Ignition delay times of Gasoline Distillation Cuts measured with Ignition Quality Tester

    KAUST Repository

    Naser, Nimal

    2017-04-21

    Tailoring fuel properties to maximize the efficiency of internal combustion engines is a way towards achieving cleaner combustion systems. In this work, the ignition properties of various gasoline fuel distillation cuts are analyzed to better understand fuel properties of the full boiling range fuel. An advanced distillation column (ADC) provides a more realistic representation of volatility characteristics, which can be modeled using equilibrium thermodynamic methods. The temperature reported is that of the liquid, as opposed to the vapor temperature in conventional ASTM D86 distillation standard. Various FACE (fuels for advanced combustion engines) gasolines were distilled and various cuts were obtained. The separated fractions were then tested in an ignition quality tester (IQT) to see the effect of chemical composition of different fractions on their ignition delay time. Fuels with lower aromatic content showed decreasing ignition delay time with increasing boiling point (i.e., molecular weight). However, fuels with higher aromatic content showed an initial decrease in ignition delay time with increasing boiling point, followed by drastic increase in ignition delay time due to fractions containing aromatics. This study also provides an understanding on contribution of different fractions to the ignition delay time of the fuel, which provides insights into fuel stratification utilized in gasoline compression ignition (GCI) engines to tailor heat release rates.

  13. Activity of the Delayed Neutron Working Group of JNDC and the International Evaluation Cooperation - WPEC/SG6

    International Nuclear Information System (INIS)

    Yoshida, Tadashi

    1999-01-01

    The Delayed Neutron Working Group was established in April 1997 within the Nuclear Data Subcommittee of JNDC. It has two principal missions. One is to coordinate the Japanese activities toward the WPEC/Subgroup-6 efforts, and the other is to recommend the delayed neutron data for JENDL-3.3. The final report of Subgroup-6, which in one of the subgroups of the NEA International Evaluation Cooperation (WPEC) and is in charge of the delayed neutron data, is to be completed in 1999. Here in Japan, JENDL-3.3 is planned to be released in early 2000. Delayed Neutron Working Group is, then, going to finalize its activity by the end of the fiscal year 1999 after recommending appropriate sets of data as coherently as possible with the of Subgroup-6 efforts. (author)

  14. Exponential synchronization of complex delayed dynamical networks via pinning periodically intermittent control

    Energy Technology Data Exchange (ETDEWEB)

    Cai Shuiming, E-mail: caishuiming2008@yahoo.com.c [Department of Mathematics, Shanghai University, Shanghai 200444 (China); Institute of System Biology, Shanghai University, Shanghai 200444 (China); Hao Junjun [Institute of System Biology, Shanghai University, Shanghai 200444 (China); He, Qinbin [Department of Mathematics, Taizhou University, Linhai 317000 (China); Institute of System Biology, Shanghai University, Shanghai 200444 (China); Liu Zengrong, E-mail: zrongliu@126.co [Department of Mathematics, Shanghai University, Shanghai 200444 (China) and Institute of System Biology, Shanghai University, Shanghai 200444 (China)

    2011-05-09

    The problem of synchronization for a class of complex delayed dynamical networks via pinning periodically intermittent control is considered in this Letter. Some novel and useful exponential synchronization criteria are obtained by utilizing the methods which are different from the techniques employed in the existing works, and the derived results are less conservative. Especially, the traditional assumptions on control width and time delays are released in our results. Moreover, a pinning scheme deciding what nodes should be chosen as pinned candidates and how many nodes are needed to be pinned for a fixed coupling strength is provided. A Barabasi-Albert network example is finally given to illustrate the effectiveness of the theoretical results. - Highlights: Pinning control problem of complex networks via intermittent control is investigated. The traditional assumptions on control width and time delays are removed. A scheme deciding what nodes should be chosen as pinned candidates is proposed. A scheme deciding how many nodes are needed to be pinned is provided.

  15. Menstrual management in developmentally delayed adolescent females.

    Science.gov (United States)

    Chuah, Irene; McRae, Alexandra; Matthews, Kim; Maguire, Ann M; Steinbeck, Katharine

    2017-06-01

    Requests for assistance in menstrual management and menstrual suppression are a common, emotive and sometimes controversial aspect of adolescent disability care. To review the uptake and outcomes of menstrual suppression among adolescent patients with developmental delay. A retrospective review of the medical records of adolescent females with intellectual disability referred for menstrual management to the Paediatric and Adolescent Gynaecology Clinic, Children's Hospital at Westmead, Sydney, for the three-year period between January 1, 2010 and January 1, 2013. Eighty adolescent patients with developmental delay were identified. A third (n = 28) of the patients were pre-menarcheal at first review with parent/caregivers seeking anticipatory advice. Of the post-menarcheal patients, the median age of menarche was 12 years (range 10-15 years). First and second line interventions were documented as were reasons for change where applicable. The combined oral contraceptive pill (COCP) was the most frequently used therapy (67%), and 19 patients in total had a levonorgestrel releasing intrauterine system (LNG-IUS) inserted (31%). Our study population differs from similar previously published groups in the marked absence of the use of depot medroxyprogesterone acetate or the subdermal etonogestrel releasing device. As a paediatrician, it is important to address menstrual management issues and allay caregiver concerns with appropriate advice. Our study supports the use of the COCP as sound first line management in achieving menstrual suppression. The LNG-IUS appears to be a favourable second line option. Further investigation into longer-term outcomes and potential complications of device insertion is recommended. © 2017 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

  16. Analytical model for release calculations in solid thin-foils ISOL targets

    Energy Technology Data Exchange (ETDEWEB)

    Egoriti, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Politecnico di Milano, Department of Energy, CeSNEF-Nuclear Engineering Division, Via Ponzio, 34/3, 20133 Milano (Italy); Boeckx, S. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); ICTEAM Inst., Univ. Catholique de Louvain, Louvain-la-Neuve (Belgium); Ghys, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Houngbo, D., E-mail: donald.houngbo@sckcen.be [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Department of Flow, Heat and Combustion Mechanics, Gent University (UGent), St.-Pietersnieuwstraat 41, B-9000 Gent (Belgium); Popescu, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium)

    2016-10-01

    A detailed analytical model has been developed to simulate isotope-release curves from thin-foils ISOL targets. It involves the separate modeling of diffusion and effusion inside the target. The former has been modeled using both first and second Fick's law. The latter, effusion from the surface of the target material to the end of the ionizer, was simulated with the Monte Carlo code MolFlow+. The calculated delay-time distribution for this process was then fitted using a double-exponential function. The release curve obtained from the convolution of diffusion and effusion shows good agreement with experimental data from two different target geometries used at ISOLDE. Moreover, the experimental yields are well reproduced when combining the release fraction with calculated in-target production.

  17. Acid Inhibitory Effect of a Combination of Omeprazole and Sodium Bicarbonate (CDFR0209) Compared With Delayed-Release Omeprazole 40 mg Alone in Healthy Adult Male Subjects.

    Science.gov (United States)

    Kim, Kyu-Nam; Yang, Sung-Won; Kim, Hyunil; Kwak, Seong Shin; Kim, Young-Sang; Cho, Doo-Yeoun

    2018-01-01

    CDFR0209, a combination of an immediate-release formulation of omeprazole 40 mg and sodium bicarbonate 1100 mg, has been developed to treat acid-related disorders. We compared the acid inhibitory effects of CDFR0209 and delayed-release omeprazole (omeprazole-DR, Losec 40 mg) after repeated dosing in Helicobacter pylori-negative healthy adult male subjects. In this 2-period crossover study, 30 subjects were randomized to CDFR0209 or omeprazole-DR daily for 7 days. An ambulatory continuous 24-hour intragastric pH recording was performed at baseline and on days 1 and 7 of each administration period. Integrated gastric acidity was calculated from time-weighted average hydrogen ion concentrations at each hour of the 24-hour record. An analysis of variance model was used to test the pharmacodynamic equivalence of CDFR0209 and omeprazole-DR, using the natural logarithmic transformation of the percent decrease from baseline in integrated gastric acidity for the 24-hour interval after the seventh dose of each omeprazole formulation. The geometric least-squares mean ratios (CDFR0209/omeprazole-DR) of the percent decrease from baseline in integrated gastric acidity was 0.98 (90%CI, 0.93-1.07). Both CDFR0209 and omeprazole-DR are equally effective in decreasing integrated gastric acidity at steady state. © 2017, The American College of Clinical Pharmacology.

  18. Fuzzy delay model based fault simulator for crosstalk delay fault test ...

    Indian Academy of Sciences (India)

    In this paper, a fuzzy delay model based crosstalk delay fault simulator is proposed. As design trends move towards nanometer technologies, more number of new parameters affects the delay of the component. Fuzzy delay models are ideal for modelling the uncertainty found in the design and manufacturing steps.

  19. The Study of Prompt and Delayed Muon Induced Fission. I.Total kinetic energies and mass distributions

    NARCIS (Netherlands)

    David, P; Hartfiel, J.; Janszen, H.; Petitjean, C.; Reist, H.W.; Polikanov, S.M.; Konijn, J.; Laat, de C.T.A.M.; Taal, A.; Krogulski, T.; Johansson, T.; Tibell, G.; Achard van Enschut, d' J.F.M.

    1987-01-01

    Mass yield and total kinetic energy release (TKE) distributions of fragments from prompt and delayed muon induced fission, separately, have been measured for the isotopes235U,238U,237Np and242Pu. The distributions from prompt muon induced fission are compared with the corresponding distributions

  20. Simulation Studies of Diffusion-Release and Effusive-Flow of Short-Lived Radioactive Isotopes

    CERN Document Server

    Zhang, Yan; Kawai, Yoko

    2005-01-01

    Delay times associated with diffusion release from targets and effusive-flow transport of radioactive isotopes to ion sources are principal intensity limiters at ISOL-based radioactive ion beam facilities, and simulation studies with computer models are cost effective methods for designing targets and vapor transport systems with minimum delay times to avoid excessive decay losses of short lived ion species. A finite difference code, Diffuse II, was recently developed at the Oak Ridge National Laboratory to study diffusion-release of short-lived species from three principal target geometries. Simulation results are in close agreement with analytical solutions to Fick’s second equation. Complementary to the development of Diffuse II, the Monte-Carlo code, Effusion, was developed to address issues related to the design of fast vapor transport systems. Results, derived by using Effusion, are also found to closely agree with experimental measurements. In this presentation, the codes will be used in conc...

  1. On the cost/delay tradeoff of wireless delay tolerant geographic routing

    OpenAIRE

    Tasiopoulos, Argyrios; Tsiaras, Christos; Toumpis, Stavros

    2012-01-01

    In Delay Tolerant Networks (DTNs), there is a fundamental tradeoff between the aggregate transport cost of a packet and the delay in its delivery. We study this tradeoff in the context of geographical routing in wireless DTNs.We ?rst specify the optimal cost/delay tradeoff, i.e., the tradeoff under optimal network operation, using a dynamic network construction termed the Cost/Delay Evolving Graph (C/DEG) and the Optimal Cost/Delay Curve (OC/DC), a function that gives the minimum possible agg...

  2. Leveraging delay discounting for health: Can time delays influence food choice?

    Science.gov (United States)

    Appelhans, Bradley M; French, Simone A; Olinger, Tamara; Bogucki, Michael; Janssen, Imke; Avery-Mamer, Elizabeth F; Powell, Lisa M

    2018-03-15

    Delay discounting, the tendency to choose smaller immediate rewards over larger delayed rewards, is theorized to promote consumption of immediately rewarding but unhealthy foods at the expense of long-term weight maintenance and nutritional health. An untested implication of delay discounting models of decision-making is that selectively delaying access to less healthy foods may promote selection of healthier (immediately available) alternatives, even if they may be less desirable. The current study tested this hypothesis by measuring healthy versus regular vending machine snack purchasing before and during the implementation of a 25-s time delay on the delivery of regular snacks. Purchasing was also examined under a $0.25 discount on healthy snacks, a $0.25 tax on regular snacks, and the combination of both pricing interventions with the 25-s time delay. Across 32,019 vending sales from three separate vending locations, the 25-s time delay increased healthy snack purchasing from 40.1% to 42.5%, which was comparable to the impact of a $0.25 discount (43.0%). Combining the delay and the discount had a roughly additive effect (46.0%). However, the strongest effects were seen under the $0.25 tax on regular snacks (53.7%) and the combination of the delay and the tax (50.2%). Intervention effects varied substantially between vending locations. Importantly, time delays did not harm overall vending sales or revenue, which is relevant to the real-world feasibility of this intervention. More investigation is needed to better understand how the impact of time delays on food choice varies across populations, evaluate the effects of time delays on beverage vending choices, and extend this approach to food choices in contexts other than vending machines. ClinicalTrials.gov, NCT02359916. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Delayed-release oral suspension of omeprazole for the treatment of erosive esophagitis and gastroesophageal reflux disease in pediatric patients: a review

    Directory of Open Access Journals (Sweden)

    Alice Monzani

    2010-03-01

    Full Text Available Alice Monzani, Giuseppina Oderda1Department of Pediatrics, Università del Piemonte Orientale, Novara, ItalyAbstract: Omeprazole is a proton-pump inhibitor indicated for gastroesophageal reflux disease and erosive esophagitis treatment in children. The aim of this review was to evaluate the efficacy of delayed-release oral suspension of omeprazole in childhood esophagitis, in terms of symptom relief, reduction in reflux index and/or intragastric acidity, and endoscopic and/or histological healing. We systematically searched PubMed, Cochrane and EMBASE (1990 to 2009 and identified 59 potentially relevant articles, but only 12 articles were suitable to be included in our analysis. All the studies evaluated symptom relief and reported a median relief rate of 80.4% (range 35%–100%. Five studies reported a significant reduction of the esophageal reflux index within normal limits (<7% in all children, and 4 studies a significant reduction of intra-gastric acidity. The endoscopic healing rate, reported by 9 studies, was 84% after 8-week treatment and 95% after 12-week treatment, the latter being significantly higher than the histological healing rate (49%. In conclusion, omeprazole given at a dose ranging from 0.3 to 3.5 mg/kg once daily (median 1 mg/kg once daily for at least 12 weeks is highly effective in childhood esophagitis.Keywords: proton pump inhibitors, children, ranitidine, H2-blockers

  4. Representing delayed force feedback as a combination of current and delayed states.

    Science.gov (United States)

    Avraham, Guy; Mawase, Firas; Karniel, Amir; Shmuelof, Lior; Donchin, Opher; Mussa-Ivaldi, Ferdinando A; Nisky, Ilana

    2017-10-01

    To adapt to deterministic force perturbations that depend on the current state of the hand, internal representations are formed to capture the relationships between forces experienced and motion. However, information from multiple modalities travels at different rates, resulting in intermodal delays that require compensation for these internal representations to develop. To understand how these delays are represented by the brain, we presented participants with delayed velocity-dependent force fields, i.e., forces that depend on hand velocity either 70 or 100 ms beforehand. We probed the internal representation of these delayed forces by examining the forces the participants applied to cope with the perturbations. The findings showed that for both delayed forces, the best model of internal representation consisted of a delayed velocity and current position and velocity. We show that participants relied initially on the current state, but with adaptation, the contribution of the delayed representation to adaptation increased. After adaptation, when the participants were asked to make movements with a higher velocity for which they had not previously experienced with the delayed force field, they applied forces that were consistent with current position and velocity as well as delayed velocity representations. This suggests that the sensorimotor system represents delayed force feedback using current and delayed state information and that it uses this representation when generalizing to faster movements. NEW & NOTEWORTHY The brain compensates for forces in the body and the environment to control movements, but it is unclear how it does so given the inherent delays in information transmission and processing. We examined how participants cope with delayed forces that depend on their arm velocity 70 or 100 ms beforehand. After adaptation, participants applied opposing forces that revealed a partially correct representation of the perturbation using the current and the

  5. A multifunctional multimaterial system for on-demand protein release.

    Science.gov (United States)

    Tuncaboylu, Deniz Ceylan; Friess, Fabian; Wischke, Christian; Lendlein, Andreas

    2018-06-15

    In order to provide best control of the regeneration process for each individual patient, the release of protein drugs administered during surgery may need to be timely adapted and/or delayed according to the progress of healing/regeneration. This study aims to establish a multifunctional implant system for a local on-demand release, which is applicable for various types of proteins. It was hypothesized that a tubular multimaterial container kit, which hosts the protein of interest as a solution or gel formulation, would enable on-demand release if equipped with the capacity of diameter reduction upon external stimulation. Using devices from poly(ɛ-caprolactone) networks, it could be demonstrated that a shape-memory effect activated by heat or NIR light enabled on-demand tube shrinkage. The decrease of diameter of these shape-memory tubes (SMT) allowed expelling the payload as demonstrated for several proteins including SDF-1α, a therapeutically relevant chemotactic protein, to achieve e.g. continuous release with a triggered add-on dosing (open tube) or an on-demand onset of bolus or sustained release (sealed tube). Considering the clinical relevance of protein factors in (stem) cell attraction to lesions and the progress in monitoring biomarkers in body fluids, such on-demand release systems may be further explored e.g. in heart, nerve, or bone regeneration in the future. Copyright © 2018. Published by Elsevier B.V.

  6. Asymptotic Delay Analysis for Cross-Layer Delay-Based Routing in Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Philippe Jacquet

    2007-01-01

    Full Text Available This paper addresses the problem of the evaluation of the delay distribution via analytical means in IEEE 802.11 wireless ad hoc networks. We show that the asymptotic delay distribution can be expressed as a power law. Based on the latter result, we present a cross-layer delay estimation protocol and we derive new delay-distribution-based routing algorithms, which are well adapted to the QoS requirements of real-time multimedia applications. In fact, multimedia services are not sensitive to average delays, but rather to the asymptotic delay distributions. Indeed, video streaming applications drop frames when they are received beyond a delay threshold, determined by the buffer size. Although delay-distribution-based routing is an NP-hard problem, we show that it can be solved in polynomial time when the delay threshold is large, because of the asymptotic power law distribution of the link delays.

  7. Dynamics of shear-induced ATP release from red blood cells.

    Science.gov (United States)

    Wan, Jiandi; Ristenpart, William D; Stone, Howard A

    2008-10-28

    Adenosine triphosphate (ATP) is a regulatory molecule for many cell functions, both for intracellular and, perhaps less well known, extracellular functions. An important example of the latter involves red blood cells (RBCs), which help regulate blood pressure by releasing ATP as a vasodilatory signaling molecule in response to the increased shear stress inside arterial constrictions. Although shear-induced ATP release has been observed widely and is believed to be triggered by deformation of the cell membrane, the underlying mechanosensing mechanism inside RBCs is still controversial. Here, we use an in vitro microfluidic approach to investigate the dynamics of shear-induced ATP release from human RBCs with millisecond resolution. We demonstrate that there is a sizable delay time between the onset of increased shear stress and the release of ATP. This response time decreases with shear stress, but surprisingly does not depend significantly on membrane rigidity. Furthermore, we show that even though the RBCs deform significantly in short constrictions (duration of increased stress <3 ms), no measurable ATP is released. This critical timescale is commensurate with a characteristic membrane relaxation time determined from observations of the cell deformation by using high-speed video. Taken together our results suggest a model wherein the retraction of the spectrin-actin cytoskeleton network triggers the mechanosensitive ATP release and a shear-dependent membrane viscosity controls the rate of release.

  8. Delayed fission

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukawa, Yuichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    Delayed fission is a nuclear decay process that couples {beta} decay and fission. In the delayed fission process, a parent nucleus undergoes {beta} decay and thereby populates excited states in the daughter. If these states are of energies comparable to or greater than the fission barrier of the daughter, then fission may compete with other decay modes of the excited states in the daughter. In this paper, mechanism and some experiments of the delayed fission will be discussed. (author)

  9. Controlled release of agrochemicals intercalated into montmorillonite interlayer space.

    Science.gov (United States)

    Wanyika, Harrison

    2014-01-01

    Periodic application of agrochemicals has led to high cost of production and serious environmental pollution. In this study, the ability of montmorillonite (MMT) clay to act as a controlled release carrier for model agrochemical molecules has been investigated. Urea was loaded into MMT by a simple immersion technique while loading of metalaxyl was achieved by a rotary evaporation method. The successful incorporation of the agrochemicals into the interlayer space of MMT was confirmed by several techniques, such as, significant expansion of the interlayer space, reduction of Barrett-Joyner-Halenda (BJH) pore volumes and Brunauer-Emmett-Teller (BET) surface areas, and appearance of urea and metalaxyl characteristic bands on the Fourier-transform infrared spectra of the urea loaded montmorillonite (UMMT) and metalaxyl loaded montmorillonite (RMMT) complexes. Controlled release of the trapped molecules from the matrix was done in water and in the soil. The results reveal slow and sustained release behaviour for UMMT for a period of 10 days in soil. For a period of 30 days, MMT delayed the release of metalaxyl in soil by more than 6 times. It is evident that MMT could be used to improve the efficiency of urea and metalaxyl delivery in the soil.

  10. Hypsometric amplification and routing moderation of Greenland ice sheet meltwater release

    Science.gov (United States)

    van As, Dirk; Mikkelsen, Andreas Bech; Holtegaard Nielsen, Morten; Box, Jason E.; Claesson Liljedahl, Lillemor; Lindbäck, Katrin; Pitcher, Lincoln; Hasholt, Bent

    2017-06-01

    Concurrent ice sheet surface runoff and proglacial discharge monitoring are essential for understanding Greenland ice sheet meltwater release. We use an updated, well-constrained river discharge time series from the Watson River in southwest Greenland, with an accurate, observation-based ice sheet surface mass balance model of the ˜ 12 000 km2 ice sheet area feeding the river. For the 2006-2015 decade, we find a large range of a factor of 3 in interannual variability in discharge. The amount of discharge is amplified ˜ 56 % by the ice sheet's hypsometry, i.e., area increase with elevation. A good match between river discharge and ice sheet surface meltwater production is found after introducing elevation-dependent transit delays that moderate diurnal variability in meltwater release by a factor of 10-20. The routing lag time increases with ice sheet elevation and attains values in excess of 1 week for the upper reaches of the runoff area at ˜ 1800 m above sea level. These multi-day routing delays ensure that the highest proglacial discharge levels and thus overbank flooding events are more likely to occur after multi-day melt episodes. Finally, for the Watson River ice sheet catchment, we find no evidence of meltwater storage in or release from the en- and subglacial environments in quantities exceeding our methodological uncertainty, based on the good match between ice sheet runoff and proglacial discharge.

  11. Fuzzy delay model based fault simulator for crosstalk delay fault test ...

    Indian Academy of Sciences (India)

    In this paper, a fuzzy delay model based crosstalk delay fault simulator is proposed. As design .... To find the quality of non-robust tests, a fuzzy delay ..... Dubois D and Prade H 1989 Processing Fuzzy temporal knowledge. IEEE Transactions ...

  12. Selective induction of cyclin B protein abrogates the G2 delay after irradiation

    International Nuclear Information System (INIS)

    Kao, G.; Muschel, R.J.; Maity, A.; Kunig, A.; McKenna, W.G.

    1996-01-01

    Purpose/Objective: Irradiation of tumor cells commonly results in G2 delay, which has been postulated to allow DNA repair and cell survival. The G2 delay after irradiation is also often marked in some cell lines by delayed expression of cyclin B protein, suggesting a role for cyclin B regulation. Investigations of these hypotheses however has been hampered by the inability to selectively perturb the G2 delay in a physiologic manner. Materials and Methods: We have devised a system, with which we are able to selectively induce cyclin B protein expression in vivo at specific points in the cell cycle, by transfecting Hela cells with an expression vector under control of a dexamethasone-inducible promoter. Experiments were subsequently performed by synchronizing, releasing, irradiating, inducing, and harvesting these cells through the cell cycle. Results: Irradiation with 5 Gy led to a pronounced G2 delay, reflected by markedly slowed progression into mitosis, concomitant with reduced expression of cyclin B protein. Induction of cyclin B after radiation in these cells abrogated the G2 delay by approximately doubling the rate at which the cells re-enter mitosis. Treatment of irradiated untransfected control cells with dexamethasone, in which cyclin B is not induced, led to minimal changes. Studies of effects of cyclin B induction on cyclin B localization (using immunofluorescence), cdc2 phosphorylation and activation will also be presented. Conclusion: This system should allow further investigations into fundamental mechanisms of cell cycle regulation after irradiation and DNA damage. This also provides direct evidence for the first time that cyclin B protein regulation may play a role in the G2 delay following irradiation in Hela cells, perhaps complementing phosphorylation events

  13. Patient Delay, Diagnosis Delay and Treatment Delay for Breast Cancer: Comparison of the Pattern between Patients in Public and Private Health Sectors

    Directory of Open Access Journals (Sweden)

    Iraj Harirchi

    2015-05-01

    Full Text Available Background: The purpose of this study was to compare patient delay, diagnosis delay and treatment delay in breast cancer patients of selected public and private health centers in Tehran, Iran.Methods: In this cross-sectional study, female patients with newly diagnosed breast cancer in a public medical complex and a private breast clinic within one year were included. Patient delay was considered positive, if the interval between the detection of the first symptom by the patient and the first visit to a health care provider took longer than one month. Delay in diagnosis was defined as the period of more than one week between the first medical visit for the symptoms and the diagnosis of breast cancer. Following the confirmed diagnosis of breast malignancy, if the medical treatment was initiated later than one week, treatment delay had occurred. The potential reasons for patient, diagnosis and treatment delay according to the patients’ reports were also recorded.Results: Overall, 385 patients were included of whom 52.7% were recruited from the public hospitals and 47.3% from a private clinic. The prevalence of patient delay, diagnosis delay and treatment delay were 31.7%, 17.9% and 28.3%, respectively. Patient delay was significantly more common among patients with lower socio-economic status and those recruited from the public hospitals. All the patients with diagnosis delay were in the group recruited from the public hospitals.Conclusions: Gaps between women of different socio-economic levels of the society need to be addressed in order to decrease patient, diagnosis and treatment delay.

  14. Role of Delay on Planktonic Ecosystem in the Presence of a Toxic Producing Phytoplankton

    Directory of Open Access Journals (Sweden)

    Swati Khare

    2011-01-01

    Full Text Available A mathematical model is proposed to study the role of distributed delay on plankton ecosystem in the presence of a toxic producing phytoplankton. The model includes three state variables, namely, nutrient concentration, phytoplankton biomass, and zooplankton biomass. The release of toxic substance by phytoplankton species reduces the growth of zooplankton and this plays an important role in plankton dynamics. In this paper, we introduce a delay (time-lag in the digestion of nutrient by phytoplankton. The stability analysis of all the feasible equilibria are studied and the existence of Hopf-bifurcation for the interior equilibrium of the system is explored. From the above analysis, we observe that the supply rate of nutrient and delay parameter play important role in changing the dynamical behaviour of the underlying system. Further, we have derived the explicit algorithm which determines the direction and the stability of Hopf-bifurcation solution. Finally, numerical simulation is carried out to support the theoretical result.

  15. Speech and Language Delay

    Science.gov (United States)

    ... OTC Relief for Diarrhea Home Diseases and Conditions Speech and Language Delay Condition Speech and Language Delay Share Print Table of Contents1. ... Treatment6. Everyday Life7. Questions8. Resources What is a speech and language delay? A speech and language delay ...

  16. Development of modified release 3D printed tablets (printlets) with pharmaceutical excipients using additive manufacturing.

    Science.gov (United States)

    Goyanes, Alvaro; Fina, Fabrizio; Martorana, Annalisa; Sedough, Daniel; Gaisford, Simon; Basit, Abdul W

    2017-07-15

    The aim of this study was to manufacture 3D printed tablets (printlets) from enteric polymers by single filament fused deposition modeling (FDM) 3D printing (3DP). Hot melt extrusion was used to generate paracetamol-loaded filaments from three different grades of the pharmaceutical excipient hypromellose acetate succinate (HPMCAS), grades LG, MG and HG. One-step 3DP was used to process these filaments into enteric printlets incorporating up to 50% drug loading with two different infill percentages (20 and 100%). X-ray Micro Computed Tomography (Micro-CT) analysis revealed that printlets with 20% infill had cavities in the core compared to 100% infill, and that the density of the 50% drug loading printlets was higher than the equivalent formulations loaded with 5% drug. In biorelevant bicarbonate dissolution media, drug release from the printlets was dependent on the polymer composition, drug loading and the internal structure of the formulations. All HPMCAS-based printlets showed delayed drug release properties, and in the intestinal conditions, drug release was faster from the printlets prepared with polymers with a lower pH-threshold: HPMCAS LG > HPMCAS MG > HPMCAS HG. These results confirm that FDM 3D printing makes it possible not only to manufacture delayed release printlets without the need for an outer enteric coating, but it is also feasible to adapt the release profile in response to the personal characteristics of the patient, realizing the full potential of additive manufacturing in the development of personalised dose medicines. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Controlled Aloin Release from Crosslinked Polyacrylamide Hydrogels: Effects of Mesh Size, Electric Field Strength and a Conductive Polymer

    Directory of Open Access Journals (Sweden)

    Anuvat Sirivat

    2013-10-01

    Full Text Available The aim of this paper is to investigate the effects of hydrogel mesh size, a conductive polymer, and electric field strength on controlled drug delivery phenomena using drug-loaded polyacrylamide hydrogels prepared at various crosslinking ratios both with and without a conductive polymer system. Poly(p-phenylene vinylene, PPV, as the model conductive polymer, was used to study its ability to control aloin released from aloin-doped poly(p-phenylene vinylene/polyacrylamide hydrogel (aloin-doped PPV/PAAM. In the passive release, the diffusion of aloin from five aloin-doped PPV/PAAM hydrogel systems each was delayed ranging from during the first three hours to during the first 14 h due to the ionic interaction between the anionic drug and PPV. After the delayed periods, aloin could diffuse continuously into the buffer solution through the PAAM matrix. The amount of aloin released from the aloin-doped PPV/PAAM rose with increasing electric field strength as a result of the three mechanisms: the expansion of PPV chains inside the hydrogel, iontophoresis, and the electroporation of the matrix pore size, combined. Furthermore, the conductive polymer and the electric field could be used in combination to regulate the amount of release drug to a desired level, to control the release rate, and to switch the drug delivery on/off.

  18. Effect of in vitro inorganic lead on dopamine release from superfused rat striatal synaptosomes

    International Nuclear Information System (INIS)

    Minnema, D.J.; Greenland, R.D.; Michaelson, I.A.

    1986-01-01

    The effect of inorganic lead in vitro in several aspects of [ 3 H]dopamine release from superfused rat striatal synaptosomes was examined. Under conditions of spontaneous release, lead (1-30 microM) induced dopamine release in a concentration-dependent manner. The onset of the lead-induced release was delayed by approximately 15-30 sec. The magnitude of dopamine release induced by lead was increased when calcium was removed from the superfusing buffer. Lead-induced release was unaffected in the presence of putative calcium, sodium, and/or potassium channel blockers (nickel, tetrodotoxin, tetraethylammonium, respectively). Depolarization-evoked dopamine release, produced by a 1-sec exposure to 61 mM potassium, was diminished at calcium concentrations below 0.254 mM. The onset of depolarization-evoked release was essentially immediate following exposure of the synaptosomes to high potassium. The combination of lead (3 or 10 microM) with high potassium reduced the magnitude of depolarization-evoked dopamine release. This depression of depolarization-evoked release by lead was greater in the presence of 0.25 mM than 2.54 mM calcium in the superfusing buffer. These findings demonstrate multiple actions of lead on synaptosomal dopamine release. Lead can induce dopamine release by yet unidentified neuronal mechanisms independent of external calcium. Lead can also reduce depolarization-evoked dopamine release by apparent competition with calcium influx at the neuronal membrane calcium channel

  19. Synchronization of delayed systems in the presence of delay time modulation

    International Nuclear Information System (INIS)

    Kye, Won-Ho; Choi, Muhan; Kim, Myung-Woon; Lee, Soo-Young; Rim, Sunghwan; Kim, Chil-Min; Park, Young-Jai

    2004-01-01

    We investigate synchronization in the presence of delay time modulation for application to communication. We have observed that the robust synchronization is established by a common delay signal and its threshold is presented using Lyapunov exponents analysis. The influence of the delay time modulation in chaotic oscillators is also discussed

  20. Tritium and helium retention and release from irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; Longhurst, G.R.; Oates, M.A.; Pawelko, R.J. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1998-01-01

    This paper reports the results of an experimental effort to anneal irradiated beryllium specimens and characterize them for steam-chemical reactivity experiments. Fully-dense, consolidated powder metallurgy Be cylinders, irradiated in the EBR-II to a fast neutron (>0.1 MeV) fluence of {approx}6 x 10{sup 22} n/cm{sup 2}, were annealed at temperatures from 450degC to 1200degC. The releases of tritium and helium were measured during the heat-up phase and during the high-temperature anneals. These experiments revealed that, at 600degC and below, there was insignificant gas release. Tritium release at 700degC exhibited a delayed increase in the release rate, while the specimen was at 700degC. For anneal temperatures of 800degC and higher, tritium and helium release was concurrent and the release behavior was characterized by gas-burst peaks. Essentially all of the tritium and helium was released at temperatures of 1000degC and higher, whereas about 1/10 of the tritium was released during the anneals at 700degC and 800degC. Measurements were made to determine the bulk density, porosity and specific surface area for each specimen before and after annealing. These measurements indicated that annealing caused the irradiated Be to swell, by as much as 14% at 700degC and 56% at 1200degC. Kr gas adsorption measurements for samples annealed at 1000degC and 1200degC determined specific surface areas between 0.04 m{sup 2}/g and 0.1 m{sup 2}/g for these annealed specimens. The tritium and helium gas release measurements and the specific surface area measurements indicated that annealing of irradiated Be caused a porosity network to evolve and become surface-connected to relieve internal gas pressure. (author)

  1. The interaction evolution model of mass incidents with delay in a social network

    Science.gov (United States)

    Huo, Liang'an; Ma, Chenyang

    2017-10-01

    Recent years have witnessed rapid development of information technology. Today, modern media is widely used for the purpose of spreading information rapidly and widely. In particular, through micro-blog promotions, individuals tend to express their viewpoints and spread information on the internet, which could easily lead to public opinions. Moreover, government authorities also disseminate official information to guide public opinion and eliminate any incorrect conjecture. In this paper, a dynamical model with two delays is investigated to exhibit the interaction evolution between the public and official opinion fields in network mass incidents. Based on the theory of differential equations, the interaction mechanism between two public opinion fields in a micro-blog environment is analyzed. Two delays are proposed in the model to depict the response delays of public and official opinion fields. Some stable conditions are obtained, which shows that Hopf bifurcation can occur as delays cross critical values. Further, some numerical simulations are carried out to verify theoretical results. Our model indicates that there exists a golden time for government intervention, which should be emphasized given the impact of modern media and inaccurate rumors. If the government releases official information during the golden time, mass incidents on the internet can be controlled effectively.

  2. Nutrient Release from Disturbance of Infiltration System Soils during Construction

    Directory of Open Access Journals (Sweden)

    Daniel P. Treese

    2012-01-01

    Full Text Available Subsurface infiltration and surface bioretention systems composed of engineered and/or native soils are preferred tools for stormwater management. However, the disturbance of native soils, especially during the process of adding amendments to improve infiltration rates and pollutant removal, may result in releases of nutrients in the early life of these systems. This project investigated the nutrient release from two soils, one disturbed and one undisturbed. The disturbed soil was collected intact, but had to be air-dried, and the columns repacked when soil shrinkage caused bypassing of water along the walls of the column. The undisturbed soil was collected and used intact, with no repacking. The disturbed soil showed elevated releases of nitrogen and phosphorus compared to the undisturbed soil for approximately 0.4 and 0.8 m of runoff loading, respectively. For the undisturbed soil, the nitrogen release was delayed, indicating that the soil disturbance accelerated the release of nitrogen into a very short time period. Leaving the soil undisturbed resulted in lower but still elevated effluent nitrogen concentrations over a longer period of time. For phosphorus, these results confirm prior research which demonstrated that the soil, if shown to be phosphorus-deficient during fertility testing, can remove phosphorus from runoff even when disturbed.

  3. Releases of radioactive substances from Swedish nuclear power plants (RAKU)

    Energy Technology Data Exchange (ETDEWEB)

    Ingemansson, T.; Bergstroem, C. [ALARA Engineering AB, Skultuna (Sweden)

    1997-04-01

    Releases of radioactivity to air and water from Swedish nuclear power plants have been studied and compared with those from foreign reactors. Averaged over the years from commissioning of the reactors to the last year data are available, the release of radioactive noble gas from the Swedish BWRs has been about the same as from comparable foreign reactors. The oldest Swedish BWRs, Oskarshamn 1 and 2 (O1 and O2) and Ringhals 1 (R1), have simple off-gas systems with only one delay volume. All BWRs in US, Germany, Japan and Switzerland are equipped with more sophisticated off-gas systems. It can be expected that O1, O2 and R1 therefore will have the highest release of noble gas activity at an international comparison if they do not modernize their off-gas system. BWRs in US, Germany and Japan are today equipped with recombiners and with one exception also charcoal columns. Japanese BWRs report zero releases to air. Releases of radioactivity to water after commissioning was about the same for most of the studied reactors. Some of the newest German plants have had low annual releases already at commissioning. Improvements of the treatment systems at old German, Swiss and US reactors have significantly lowered the releases. For most of the Swedish plants the annual releases to water have remained at the initial level. Forsmark 3 has succeeded in decreasing the release of radionuclides to water by a factor of almost one hundred compared to other Swedish reactors. Also O3 has managed to decrease the liquid effluents. Japanese plants have zero release of radioactivity excluding tritium to water. The release of tritium is about the same for all reactors of the same type in the world. 35 refs, 31 figs, 24 tabs.

  4. alpha-Glucosidase inhibition (acarbose) fails to enhance secretion of glucagon-like peptide 1 (7-36 amide) and to delay gastric emptying in Type 2 diabetic patients

    DEFF Research Database (Denmark)

    Hücking, K; Kostic, Z; Pox, C

    2005-01-01

    AIM: Acarbose is able to enhance GLP-1 release and delay gastric emptying in normal subjects. The effect of alpha-glucosidase inhibition on GLP-1 has been less evident in Type 2 diabetic patients. The aim of this study was to investigate the possible influence of acarbose on GLP-1 release and gas...

  5. Chaos synchronization in time-delayed systems with parameter mismatches and variable delay times

    International Nuclear Information System (INIS)

    Shahverdiev, E.M.; Nuriev, R.A.; Hashimov, R.H.; Shore, K.A.

    2004-06-01

    We investigate synchronization between two undirectionally linearly coupled chaotic nonidentical time-delayed systems and show that parameter mismatches are of crucial importance to achieve synchronization. We establish that independent of the relation between the delay time in the coupled systems and the coupling delay time, only retarded synchronization with the coupling delay time is obtained. We show that with parameter mismatch or without it neither complete nor anticipating synchronization occurs. We derive existence and stability conditions for the retarded synchronization manifold. We demonstrate our approach using examples of the Ikeda and Mackey Glass models. Also for the first time we investigate chaos synchronization in time-delayed systems with variable delay time and find both existence and sufficient stability conditions for the retarded synchronization manifold with the coupling-delay lag time. (author)

  6. Classic conditioning in aged rabbits: delay, trace, and long-delay conditioning.

    Science.gov (United States)

    Solomon, P R; Groccia-Ellison, M E

    1996-06-01

    Young (0.5 years) and aged (2+, 3+, and 4+ years) rabbits underwent acquisition of the classically conditioned nictitating membrane response in a delay (500-ms conditioned stimulus [CS], 400-ms interstimulus interval [ISI]), long-delay (1,000-ms CS, 900-ms ISI), or trace (500-ms CS, 400-ms stimulus-free period) paradigm. Collapsing across age groups, there is a general tendency for animals to acquire trace conditioning more slowly than delay conditioning. Collapsing across conditioning paradigms, there is a general tendency for aged animals to acquire more slowly than younger animals. Of greater significance, however, are the age differences in the different conditioning paradigms. In the delay and long-delay paradigms, significant conditioning deficits first appeared in the 4(+)-year-old group. In the trace conditioning paradigm, significant conditioning deficits became apparent in the 2(+)-year-old animals.

  7. Effect of EI-treatment in relation to physiological and biochemical traits in rice: delay in germination and its recovery with provision of glucose

    International Nuclear Information System (INIS)

    Inoue, M.; Hasegawa, H.; Hori, S.

    1975-01-01

    Rice seeds treated with 0.2 to 1.2 v/v % of ethyleneimine (EI) demonstrated increasingly delayed germination concomitant with increasing dose. At the time of germination, the release of storage products was slightly inhibited at lower doses and completely reduced at higher doses. With increasing time after germination the development of shoot length, content of reducing sugar and free amino acid, and synthesis of nucleic acid and protein in treated seeds, showed the same response pattern as the control, although at reduced levels in the treated seeds. Consequently, it is interpreted that the delay of germination is due to physiological dormancy, i.e. impaired release of dormancy which would normally yield active forms of enzymes. When treated seeds were cultured in [ 14 C]-glucose medium, the specific activity of [ 14 C]-glucose was higher in late-germinating seeds than in early-germinating seeds. Furthermore, the provision of glucose prevented the delay of germination, resulting in about a 10% increase in germination rate (survival rate), and yet had no effect on subsequent growth. Finally, it is concluded that the damage resulting in delayed germination and reduction of survival differs from the damage leading to inhibition of subsequent growth in that the former can be compensated for by provision of glucose while the latter cannot. (author)

  8. Hypsometric amplification and routing moderation of Greenland ice sheet meltwater release

    Directory of Open Access Journals (Sweden)

    D. van As

    2017-06-01

    Full Text Available Concurrent ice sheet surface runoff and proglacial discharge monitoring are essential for understanding Greenland ice sheet meltwater release. We use an updated, well-constrained river discharge time series from the Watson River in southwest Greenland, with an accurate, observation-based ice sheet surface mass balance model of the  ∼  12 000 km2 ice sheet area feeding the river. For the 2006–2015 decade, we find a large range of a factor of 3 in interannual variability in discharge. The amount of discharge is amplified  ∼  56 % by the ice sheet's hypsometry, i.e., area increase with elevation. A good match between river discharge and ice sheet surface meltwater production is found after introducing elevation-dependent transit delays that moderate diurnal variability in meltwater release by a factor of 10–20. The routing lag time increases with ice sheet elevation and attains values in excess of 1 week for the upper reaches of the runoff area at  ∼  1800 m above sea level. These multi-day routing delays ensure that the highest proglacial discharge levels and thus overbank flooding events are more likely to occur after multi-day melt episodes. Finally, for the Watson River ice sheet catchment, we find no evidence of meltwater storage in or release from the en- and subglacial environments in quantities exceeding our methodological uncertainty, based on the good match between ice sheet runoff and proglacial discharge.

  9. Global synchronization criteria with channel time-delay for chaotic time-delay system

    International Nuclear Information System (INIS)

    Sun Jitao

    2004-01-01

    Based on the Lyapunov stabilization theory, matrix measure, and linear matrix inequality (LMIs), this paper studies the chaos synchronization of time-delay system using the unidirectional linear error feedback coupling with time-delay. Some generic conditions of chaos synchronization with time-delay in the transmission channel is established. The chaotic Chua's circuit is used for illustration, where the coupling parameters are determined according to the criteria under which the global chaos synchronization of the time-delay coupled systems is achieved

  10. Delayed minocycline but not delayed mild hypothermia protects against embolic stroke

    Directory of Open Access Journals (Sweden)

    Noor Raza

    2002-04-01

    Full Text Available Abstract Background Inflammatory reactions occurring in the brain after ischemia may contribute to secondary damage. In the present study, effects of minocycline, an anti-inflammatory agent, alone or in combination with mild hypothermia on focal embolic cerebral ischemia have been examined. Methods Focal ischemic injury was induced by embolizing a preformed clot into the middle cerebral artery (MCA. Infarction volume was measured at 48 h after the injury. Mortality was also recorded. Results Delayed administration of minocycline alone or delayed minocycline plus delayed mild hypothermia reduced the infarction volume significantly. However, delayed mild hypothermia alone was not protective and delayed mild hypothermia in combination with minocycline did not show any additive effect. Conclusions These results suggest that minocycline is beneficial in focal ischemic brain injury, and the lack of the enhanced neuroprotection may be due to the brief exposure to hypothermia.

  11. A Three-Pulse Release Tablet for Amoxicillin: Preparation, Pharmacokinetic Study and Physiologically Based Pharmacokinetic Modeling.

    Science.gov (United States)

    Li, Jin; Chai, Hongyu; Li, Yang; Chai, Xuyu; Zhao, Yan; Zhao, Yunfan; Tao, Tao; Xiang, Xiaoqiang

    2016-01-01

    Amoxicillin is a commonly used antibiotic which has a short half-life in human. The frequent administration of amoxicillin is often required to keep the plasma drug level in an effective range. The short dosing interval of amoxicillin could also cause some side effects and drug resistance, and impair its therapeutic efficacy and patients' compliance. Therefore, a three-pulse release tablet of amoxicillin is desired to generate sustained release in vivo, and thus to avoid the above mentioned disadvantages. The pulsatile release tablet consists of three pulsatile components: one immediate-release granule and two delayed release pellets, all containing amoxicillin. The preparation of a pulsatile release tablet of amoxicillin mainly includes wet granulation craft, extrusion/spheronization craft, pellet coating craft, mixing craft, tablet compression craft and film coating craft. Box-Behnken design, Scanning Electron Microscope and in vitro drug release test were used to help the optimization of formulations. A crossover pharmacokinetic study was performed to compare the pharmacokinetic profile of our in-house pulsatile tablet with that of commercial immediate release tablet. The pharmacokinetic profile of this pulse formulation was simulated by physiologically based pharmacokinetic (PBPK) model with the help of Simcyp®. Single factor experiments identify four important factors of the formulation, namely, coating weight of Eudragit L30 D-55 (X1), coating weight of AQOAT AS-HF (X2), the extrusion screen aperture (X3) and compression forces (X4). The interrelations of the four factors were uncovered by a Box-Behnken design to help to determine the optimal formulation. The immediate-release granule, two delayed release pellets, together with other excipients, namely, Avicel PH 102, colloidal silicon dioxide, polyplasdone and magnesium stearate were mixed, and compressed into tablets, which was subsequently coated with Opadry® film to produce pulsatile tablet of

  12. Heat release effects on mixing scales of non-premixed turbulent wall-jets: A direct numerical simulation study

    International Nuclear Information System (INIS)

    Pouransari, Zeinab; Vervisch, Luc; Johansson, Arne V.

    2013-01-01

    Highlights: ► A non-premixed turbulent flame close to a solid surface is studied using DNS. ► Heat release effects delay transition and enlarge fluctuation of density and pressure. ► The fine-scale structures damped and surface wrinkling diminished due to heat-release. ► Using semilocal scaling improves the collapse of turbulence statistic in inner region. ► There are regions of the flame where considerable (up to 10%) premixed burning occurs. -- Abstract: The present study concerns the role of heat release effects on characteristics mixing scales of turbulence in reacting wall-jet flows. Direct numerical simulations of exothermic reacting turbulent wall-jets are performed and compared to the isothermal reacting case. An evaluation of the heat-release effects on the structure of turbulence is given by examining the mixture fraction surface characteristics, diagnosing vortices and exploring the dissipation rate of the fuel and passive scalar concentrations, and moreover by illustration of probability density functions of reacting species and scatter plots of the local temperature against the mixture fraction. Primarily, heat release effects delay the transition, enlarge the fluctuation intensities of density and pressure and also enhance the fluctuation level of the species concentrations. However, it has a damping effect on all velocity fluctuation intensities and the Reynolds shear stress. A key result is that the fine-scale structures of turbulence are damped, the surface wrinkling is diminished and the vortices become larger due to heat-release effects. Taking into account the varying density by using semi-local scaling improves the collapse of the turbulence statistics in the inner region, but does not eliminate heat release induced differences in the outer region. Examining the two-dimensional premultiplied spanwise spectra of the streamwise velocity fluctuations indicates a shifting in the positions of the outer peaks, associated with large

  13. Delayed puberty in girls

    Science.gov (United States)

    ... sexual development - girls; Pubertal delay - girls; Constitutional delayed puberty ... In most cases of delayed puberty, growth changes just begin later than usual, sometimes called a late bloomer. Once puberty begins, it progresses normally. This pattern runs ...

  14. Delayed Puberty (For Teens)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Delayed Puberty KidsHealth / For Teens / Delayed Puberty What's in this ... wonder if there's anything wrong. What Is Delayed Puberty? Puberty is the time when your body grows ...

  15. Delayed xenon post-conditioning mitigates spinal cord ischemia/reperfusion injury in rabbits by regulating microglial activation and inflammatory factors.

    Science.gov (United States)

    Yang, Yan-Wei; Wang, Yun-Lu; Lu, Jia-Kai; Tian, Lei; Jin, Mu; Cheng, Wei-Ping

    2018-03-01

    The neuroprotective effect against spinal cord ischemia/reperfusion injury in rats exerted by delayed xenon post-conditioning is stronger than that produced by immediate xenon post-conditioning. However, the mechanisms underlying this process remain unclear. Activated microglia are the main inflammatory cell type in the nervous system. The release of pro-inflammatory factors following microglial activation can lead to spinal cord damage, and inhibition of microglial activation can relieve spinal cord ischemia/reperfusion injury. To investigate how xenon regulates microglial activation and the release of inflammatory factors, a rabbit model of spinal cord ischemia/reperfusion injury was induced by balloon occlusion of the infrarenal aorta. After establishment of the model, two interventions were given: (1) immediate xenon post-conditioning-after reperfusion, inhalation of 50% xenon for 1 hour, 50% N 2 /50%O 2 for 2 hours; (2) delayed xenon post-conditioning-after reperfusion, inhalation of 50% N 2 /50%O 2 for 2 hours, 50% xenon for 1 hour. At 4, 8, 24, 48 and 72 hours after reperfusion, hindlimb locomotor function was scored using the Jacobs locomotor scale. At 72 hours after reperfusion, interleukin 6 and interleukin 10 levels in the spinal cord of each group were measured using western blot assays. Iba1 levels were determined using immunohistochemistry and a western blot assay. The number of normal neurons at the injury site was quantified using hematoxylin-eosin staining. At 72 hours after reperfusion, delayed xenon post-conditioning remarkably enhanced hindlimb motor function, increased the number of normal neurons at the injury site, decreased Iba1 levels, and inhibited interleukin-6 and interleukin-10 levels in the spinal cord. Immediate xenon post-conditioning did not noticeably affect the above-mentioned indexes. These findings indicate that delayed xenon post-conditioning after spinal cord injury improves the recovery of neurological function by reducing

  16. Storage and sustained release of volatile substances from a hollow silica matrix

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jiexin [Key Lab for Nanomaterials, Ministry of Education, Beijing 100029 (China); Ding Haomin [Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China); Tao Xia [Key Lab for Nanomaterials, Ministry of Education, Beijing 100029 (China); Chen Jianfeng [Key Lab for Nanomaterials, Ministry of Education, Beijing 100029 (China)

    2007-06-20

    Porous hollow silica nanospheres (PHSNSs) prepared by adopting a nanosized CaCO{sub 3} template were utilized for the first time as a novel carrier for the storage and sustained release of volatile substances. Two types of volatile substances, Indian pipal from perfumes and peroxyacetic acid from disinfectants, were selected and then tested by one simple adsorption process with two separate comparative carriers, i.e. activated carbon and solid porous silica. It was demonstrated that a high storage capacity (9.6 ml{sub perfume}/mg{sub carrier}) of perfume could be achieved in a PHSNS matrix, which was almost 14 times as much as that of activated carbon. The perfume release profiles showed that PHSNSs exhibited sustained multi-stage release behaviour, while the constant release of activated carbon at a low level was discerned. Further, a Higuchi model study proved that the release process of perfume in both carriers followed a Fickian diffusion mechanism. For peroxyacetic acid as a disinfectant model, PHSNSs also displayed a much better delayed-delivery process than a solid porous silica system owing to the existence of unique hollow frameworks. Therefore, the aforementioned excellent sustained-release behaviours would make PHSNSs a promising carrier for storage and sustained delivery applications of volatile substances.

  17. The budget impact of introducing delayed-release dimethyl fumarate for treatment of relapse-remitting multiple sclerosis in Canada.

    Science.gov (United States)

    Dorman, Emily; Kansal, Anuraag R; Sarda, Sujata

    2015-01-01

    Multiple sclerosis (MS) causes significant disability globally and is especially prevalent in Canada. Delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) is an orally administered disease-modifying treatment (DMT) for patients with relapsing-remitting MS (RRMS) that is currently on the market in the US, Australia, Canada, and Europe. A budget impact model (BIM) was developed to assess the financial consequences of introducing DMF for treatment of RRMS in Canada. A BIM calculated the financial consequences of introducing DMF in Canada over 3 years based on RRMS prevalence, treatment market share, and clinical effects. RRMS prevalence in Canada was derived from published literature and natural relapse rates, and disease state distribution from clinical trial data. It was conservatively assumed that 100% of RRMS patients were treated with a DMT. DMF was assumed to absorb market share proportionally from the following current treatments: interferon beta-1a-IM, interferon beta-1a-SC, interferon beta-1b, and glatiramer acetate. Treatment efficacy, in terms of relapse rate reductions and treatment discontinuation rates, was determined from mixed treatment comparison. Treatment costs (including costs of acquisition, monitoring, and administration) and cost of relapse were considered. Deterministic one-way sensitivity analyses were conducted to assess the most sensitive input parameters. Over 3 years, the introduction of DMF resulted in an average annual increase of CAD417 per treated patient per year, with reductions in costs associated with relapses (CAD192/patient/year) partially offsetting increased drug acquisition costs (CAD602/patient/year). On a population level, the average annual cost increase was CAD24,654,237, a CAD 0.68 increase per population covered by the Canadian healthcare system. The main drivers of budget impact were drop-out rates, proportion of RRMS patients treated, and market share assumptions. The acquisition costs of DMF for

  18. Prompt and delayed Coulomb explosion of doubly ionized hydrogen chloride molecules in intense femtosecond laser fields

    Science.gov (United States)

    Ma, Junyang; Li, Hui; Lin, Kang; Song, Qiying; Ji, Qinying; Zhang, Wenbin; Li, Hanxiao; Sun, Fenghao; Qiang, Junjie; Lu, Peifen; Gong, Xiaochun; Zeng, Heping; Wu, Jian

    2018-06-01

    We experimentally investigate the dissociative double ionization of hydrogen chloride (HCl) molecules in intense femtosecond laser pulses. In addition to the prompt dissociation channels which occur on femtosecond timescales, long-lived hydrogen chloride dications which Coulomb-explode in flight towards the detector are clearly identified in the photoion-photoion coincidence spectrum. Different pathways leading to these prompt and delayed dissociation channels involving various bound and repulsive states of the HCl dication are discussed based on the observed kinetic energy release and momentum distributions. Our results indicate that the specific features of the HCl dication potential energy curves are responsible for the generation of the delayed fragmentation channels, which are expected to be general processes for the hydrogen halides.

  19. Exponential synchronization of chaotic systems with time-varying delays and parameter mismatches via intermittent control.

    Science.gov (United States)

    Cai, Shuiming; Hao, Junjun; Liu, Zengrong

    2011-06-01

    This paper studies the synchronization of coupled chaotic systems with time-varying delays in the presence of parameter mismatches by means of periodically intermittent control. Some novel and useful quasisynchronization criteria are obtained by using the methods which are different from the techniques employed in the existing works, and the derived results are less conservative. Especially, a strong constraint on the control width that the control width should be larger than the time delay imposed by the current references is released in this paper. Moreover, our results show that the synchronization criteria depend on the ratio of control width to control period, but not the control width or the control period. Finally, some numerical simulations are given to show the effectiveness of the theoretical results.

  20. Reward acts as a signal to control delay-period activity in delayed-response tasks.

    Science.gov (United States)

    Ichihara-Takeda, Satoe; Takeda, Kazuyoshi; Funahashi, Shintaro

    2010-03-31

    Prefrontal delay-period activity represents a neural mechanism for the active maintenance of information and needs to be controlled by some signal to appropriately operate working memory. To examine whether reward-delivery acts as this signal, the effects of delay-period activity in response to unexpected reward-delivery were examined by analyzing single-neuron activity recorded in the primate dorsolateral prefrontal cortex. Among neurons that showed delay-period activity, 34% showed inhibition of this activity in response to unexpected reward-delivery. The delay-period activity of these neurons was affected by the expectation of reward-delivery. The strength of the reward signal in controlling the delay-period activity is related to the strength of the effect of reward information on the delay-period activity. These results indicate that reward-delivery acts as a signal to control delay-period activity.

  1. Delay-dependent exponential stability of cellular neural networks with time-varying delays

    International Nuclear Information System (INIS)

    Zhang Qiang; Wei Xiaopeng; Xu Jin

    2005-01-01

    The global exponential stability of cellular neural networks (CNNs) with time-varying delays is analyzed. Two new sufficient conditions ensuring global exponential stability for delayed CNNs are obtained. The conditions presented here are related to the size of delay. The stability results improve the earlier publications. Two examples are given to demonstrate the effectiveness of the obtained results

  2. Using mass-release of engineered insects to manage insecticide resistance

    International Nuclear Information System (INIS)

    Alphey, Nina; Coleman, Paul G.; Donnelly, Christl A.

    2006-01-01

    Transgenic crops expressing insecticidal toxins derived from Bacillus thuringiensis (Bt) are widely used to control insect pests. The benefits of such crops would be lost if resistance to the toxins spread to a significant proportion of the pest population. The main resistance management method, mandatory in the US, is the high-dose/refuge strategy, requiring nearby refuges of toxin-free crops, and the use of toxin doses sufficiently high to kill not only wild type insects but also insects heterozygous for a resistance allele, thereby rendering the resistance functionally recessive. We propose that mass-release of harmless toxin-sensitive insects could substantially delay or even reverse the spread of resistance. Mass-release of such insects is an integral part of RIDL, a genetics-based method of pest control related to the Sterile Insect Technique. We used a population genetic mathematical model to analyze the effects of releasing male insects homozygous for a female-specific dominant lethal genetic construct, and concluded that this RIDL strategy could form an effective component of a resistance management scheme for insecticidal plants and other toxins. (author)

  3. Using mass-release of engineered insects to manage insecticide resistance

    Energy Technology Data Exchange (ETDEWEB)

    Alphey, Nina [University of Oxford (United Kingdom). Dept. of Zoology; Alphey, Luke [Oxitec Limited, Oxford (United Kingdom); Coleman, Paul G [London School of Hygiene and Tropical Medicine (United Kingdom). Dept. of Infectious and Tropical Diseases; Donnelly, Christl A [Imperial College Faculty of Medicine, London (United Kingdom). Dept. of Infectious Disease Epidemiology

    2006-07-01

    Transgenic crops expressing insecticidal toxins derived from Bacillus thuringiensis (Bt) are widely used to control insect pests. The benefits of such crops would be lost if resistance to the toxins spread to a significant proportion of the pest population. The main resistance management method, mandatory in the US, is the high-dose/refuge strategy, requiring nearby refuges of toxin-free crops, and the use of toxin doses sufficiently high to kill not only wild type insects but also insects heterozygous for a resistance allele, thereby rendering the resistance functionally recessive. We propose that mass-release of harmless toxin-sensitive insects could substantially delay or even reverse the spread of resistance. Mass-release of such insects is an integral part of RIDL, a genetics-based method of pest control related to the Sterile Insect Technique. We used a population genetic mathematical model to analyze the effects of releasing male insects homozygous for a female-specific dominant lethal genetic construct, and concluded that this RIDL strategy could form an effective component of a resistance management scheme for insecticidal plants and other toxins. (author)

  4. Assessing delay discounting in mice

    OpenAIRE

    Mitchell, Suzanne H.

    2014-01-01

    Delay discounting (also intertemporal choice or impulsive choice) is the process by which delayed outcomes, such as delayed food delivery, are valued less than the same outcomes delivered immediately or with a shorter delay. This process is of interest because many psychopathologies, including substance dependence, pathological gambling, attention deficit hyperactivity disorder and conduct disorder, are characterized by heightened levels of delay discounting. Some of these disorders are herit...

  5. REASONS FOR PATIENT DELAYS & HEALTH SYSTEM DELAYS FOR TUBERCULOSIS IN SOUTH INDIA

    Directory of Open Access Journals (Sweden)

    Kapil Goel

    2011-12-01

    Full Text Available Background: Globally, the burden of Tuberculosis is escalating. Early diagnosis and prompt initiation of tuberculosis treatment is essential for an effective tuberculosis control programme. Objectives: To study the self reported reasons for patient and health system (diagnosis & treatment delays in Tuberculosis patients. Methods: A community based cross sectional study was conducted among 98 new sputum positive TB cases aged > 15 years registered under RNTCP from Oct 2006 to June 2007 & receiving treatment under DOTS in Udupi taluk by interviewing them. Results: Total 98 patients were recruited and 68% were males. Out of 17 patients with patient delays, 82% felt that their symptoms were not severe, 71% felt that patient delay was due to lack of awareness and 71% did not take it seriously. Out of 86 patients with health system delays, 82.6% of patients mentioned that doctor has not advised for sputum examination, 76.7% of patients told that they first consulted a private doctor, 21% of them mentioned that doctor was unaware to diagnose TB. Conclusion: Symptoms not severe is the main reason for the patient delay and doctor didn’t advise for sputum examination is the main reason for health system delays.

  6. Delayed orgasm and anorgasmia.

    Science.gov (United States)

    Jenkins, Lawrence C; Mulhall, John P

    2015-11-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies, which include medications, penile sensation loss, endocrinopathies, penile hyperstimulation, and psychological etiologies. Unfortunately, there are no excellent pharmacotherapies for delayed orgasm/anorgasmia, and treatment revolves largely around addressing potential causative factors and psychotherapy. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  7. Continuous passive motion and physical therapy (CPM) versus physical therapy (PT) versus delayed physical therapy (DPT) after surgical release for elbow contractures; a study protocol for a prospective randomized controlled trial.

    Science.gov (United States)

    Viveen, Jetske; Doornberg, Job N; Kodde, Izaak F; Goossens, Pjotr; Koenraadt, Koen L M; The, Bertram; Eygendaal, Denise

    2017-11-22

    The elbow is prone to stiffness after trauma. To regain functional elbow motion several conservative- and surgical treatment options are available. Conservative treatment includes physical therapy, intra-articular injections with corticosteroids and a static progressive or dynamic splinting program. If conservative treatment fails, an operative release of the posttraumatic stiff elbow is often performed. The best Evidence-Based rehabilitation protocol for patients after an operative release is unknown to date and differs per surgeon, hospital and country. Options include early- or delayed motion supervised by a physical therapist, immediate continuous passive motion (CPM), (night) splinting and a static progressive or dynamic splinting program. The SET-Study (Stiff Elbow Trial) is a single-centre, prospective, randomized controlled trial. The primary objective of this study is to compare the active Range of Motion (ROM) (flexion arc and rotational arc) twelve months after surgery between three groups. The first group will receive in-hospital CPM in combination with early motion Physical Therapy (PT) supervised by a physical therapist, the second group will receive only in-hospital early motion PT supervised by a physical therapist and the third group will receive outpatient supervised PT from postoperative day seven till ten. Secondary outcome measures will be Patient Reported Outcome Measures (PROMs) including the Mayo Elbow Performance Score (MEPS), the Oxford Elbow Score (OES), the quick Disabilities of Arm, Shoulder and Hand (qDASH) score, Visual Analogue pain Scale in rest and activity (VAS), Pain Catastrophizing Scale (PCS), the Short Form (SF)-36, the Centre for Epidemiological Studies Depression Scale Revised (CESD-R) and the Work Rehabilitation Questionnaire (WORQ) for the upper limb. A successful completion of this trial will provide evidence on the best rehabilitation protocol in order to (re)gain optimal motion after surgical release of the stiff elbow

  8. Modulation of release kinetics by plasma polymerization of ampicillin-loaded β -TCP ceramics

    International Nuclear Information System (INIS)

    Labay, C; Buxadera-Palomero, J; Avilés, M; Canal, C; Ginebra, M P

    2016-01-01

    Beta-tricalcium phosphate ( β -TCP) bioceramics are employed in bone repair surgery. Their local implantation in bone defects puts them in the limelight as potential materials for local drug delivery. However, obtaining suitable release patterns fitting the required therapeutics is a challenge. Here, plasma polymerization of ampicillin-loaded β -TCP is studied for the design of a novel antibiotic delivery system. Polyethylene glycol-like (PEG-like) coating of β -TCP by low pressure plasma polymerization was performed using diglyme as precursor, and nanometric PEG-like layers were obtained by simple and double plasma polymerization processes. A significant increase in hydrophobicity, and the presence of plasma polymer was visible on the surface by SEM and quantified by XPS. As a main consequence of the plasma polymerisation, the release kinetics were successfully modified, avoiding burst release, and slowing down the initial rate of release leading to a 4.5 h delay in reaching the same antibiotic release percentage, whilst conservation of the activity of the antibiotic was simultaneously maintained. Thus, plasma polymerisation on the surface of bioceramics may be a good strategy to design controlled drug delivery matrices for local bone therapies. (paper)

  9. Surfactant protein D delays Fas- and TRAIL-mediated extrinsic pathway of apoptosis in T cells.

    Science.gov (United States)

    Djiadeu, Pascal; Kotra, Lakshmi P; Sweezey, Neil; Palaniyar, Nades

    2017-05-01

    Only a few extracellular soluble proteins are known to modulate apoptosis. We considered that surfactant-associated protein D (SP-D), an innate immune collectin present on many mucosal surfaces, could regulate apoptosis. Although SP-D is known to be important for immune cell homeostasis, whether SP-D affects apoptosis is unknown. In this study we aimed to determine the effects of SP-D on Jurkat T cells and human T cells dying by apoptosis. Here we show that SP-D binds to Jurkat T cells and delays the progression of Fas (CD95)-Fas ligand and TRAIL-TRAIL receptor induced, but not TNF-TNF receptor-mediated apoptosis. SP-D exerts its effects by reducing the activation of initiator caspase-8 and executioner caspase-3. SP-D also delays the surface exposure of phosphatidylserine. The effect of SP-D was ablated by the presence of caspase-8 inhibitor, but not by intrinsic pathway inhibitors. The binding ability of SP-D to dying cells decreases during the early stages of apoptosis, suggesting the release of apoptotic cell surface targets during apoptosis. SP-D also delays FasL-induced death of primary human T cells. SP-D delaying the progression of the extrinsic pathway of apoptosis could have important implications in regulating immune cell homeostasis at mucosal surfaces.

  10. Ion release from magnesium materials in physiological solutions under different oxygen tensions.

    Science.gov (United States)

    Feyerabend, Frank; Drücker, Heiko; Laipple, Daniel; Vogt, Carla; Stekker, Michael; Hort, Norbert; Willumeit, Regine

    2012-01-01

    Although magnesium as degradable biomaterial already showed clinical proof of concepts, the design of new alloys requires predictive in vitro methods, which are still lacking. Incubation under cell culture conditions to obtain "physiological" corrosion may be a solution. The aim of this study was to analyse the influence of different solutions, addition of proteins and of oxygen availability on the corrosion of different magnesium materials (pure Mg, WE43, and E11) with different surface finishing. Oxygen content in solution, pH, osmolality and ion release were determined. Corrosion led to a reduction of oxygen in solution. The influence of oxygen on pH was enhanced by proteins, while osmolality was not influenced. Magnesium ion release was solution-dependent and enhanced in the initial phase by proteins with delayed release of alloying elements. The main corrosion product formed was magnesium carbonate. Therefore, cell culture conditions are proposed as first step toward physiological corrosion.

  11. Comparative steady-state pharmacokinetic study of an extended-release formulation of itopride and its immediate-release reference formulation in healthy volunteers

    Directory of Open Access Journals (Sweden)

    Yoon S

    2014-01-01

    Full Text Available Seonghae Yoon,1,* Howard Lee,2,* Tae-Eun Kim,1 SeungHwan Lee,1 Dong-Hyun Chee,3 Joo-Youn Cho,1 Kyung-Sang Yu,1 In-Jin Jang1 1Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, 2Clinical Trials Center, Seoul National University Hospital, 3AbbVie Ltd., Seoul, Republic of Korea *These authors contributed equally to this work Background: This study was conducted to compare the oral bioavailability of an itopride extended-release (ER formulation with that of the reference immediate-release (IR formulation in the fasting state. The effect of food on the bioavailability of itopride ER was also assessed. Methods: A single-center, open-label, randomized, multiple-dose, three-treatment, three-sequence, crossover study was performed in 24 healthy male subjects, aged 22–48 years, who randomly received one of the following treatments for 4 days in each period: itopride 150 mg ER once daily under fasting or fed conditions, or itopride 50 mg IR three times daily in the fasting state. Steady-state pharmacokinetic parameters of itopride, including peak plasma concentration (Cmax and area under the plasma concentration versus time curve over 24 hours after dosing (AUC0–24h, were determined by noncompartmental analysis. The geometric mean ratio of the pharmacokinetic parameters was derived using an analysis of variance model. Results: A total of 24 healthy Korean subjects participated, 23 of whom completed the study. The geometric mean ratio and its 90% confidence interval of once-daily ER itopride versus IR itopride three times a day for AUC0–24h were contained within the conventional bioequivalence range of 0.80–1.25 (0.94 [0.88–1.01], although Cmax was reached more slowly and was lower for itopride ER than for the IR formulation. Food delayed the time taken to reach Cmax for itopride ER, but AUC0–24h was not affected. There were no serious adverse events and both formulations were

  12. Endurance exercise modulates levodopa induced growth hormone release in patients with Parkinson's disease.

    Science.gov (United States)

    Müller, Thomas; Welnic, Jacub; Woitalla, Dirk; Muhlack, Siegfried

    2007-07-11

    Acute levodopa (LD) application and exercise release human growth hormone (GH). An earlier trial showed, that combined stimulus of exercise and LD administration is the best provocative test for GH response in healthy participants. Objective was to show this combined effect of LD application and exercise on GH response and to investigate the impact on LD metabolism in 20 previously treated patients with Parkinson's disease (PD). We measured GH- and LD plasma concentrations following soluble 200 mg LD/50 mg benserazide administration during endurance exercise and rest on two separate consecutive days. GH concentrations significantly increased on both days, but GH release was significantly delayed during rest. LD metabolism was not altered due to exercise in a clinical relevant manner. Exercise induced a significant faster LD stimulated GH release in comparison with the rest condition. We did not find the supposed increase of LD induced GH release by endurance exercise. We assume, that only a limited amount of GH is available for GH release in the anterior pituitary following an acute 200 mg LD administration. GH disposal also depends on growth hormone releasing hormone (GHRH), which is secreted into hypothalamic portal capillaries. During the exercise condition, the resulting higher blood pressure supports blood flow and thus GHRH transport towards the GH producing cells in the pituitary. This might additionally have caused the significant faster GH release during exercise.

  13. Envenomations by Bothrops and Crotalus snakes induce the release of mitochondrial alarmins.

    Directory of Open Access Journals (Sweden)

    Irene Zornetta

    Full Text Available Skeletal muscle necrosis is a common manifestation of viperid snakebite envenomations. Venoms from snakes of the genus Bothrops, such as that of B. asper, induce muscle tissue damage at the site of venom injection, provoking severe local pathology which often results in permanent sequelae. In contrast, the venom of the South American rattlesnake Crotalus durissus terrificus, induces a clinical picture of systemic myotoxicity, i.e., rhabdomyolysis, together with neurotoxicity. It is known that molecules released from damaged muscle might act as 'danger' signals. These are known as 'alarmins', and contribute to the inflammatory reaction by activating the innate immune system. Here we show that the venoms of B. asper and C. d. terrificus release the mitochondrial markers mtDNA (from the matrix and cytochrome c (Cyt c from the intermembrane space, from ex vivo mouse tibialis anterior muscles. Cyt c was released to a similar extent by the two venoms whereas B. asper venom induced the release of higher amounts of mtDNA, thus reflecting hitherto some differences in their pathological action on muscle mitochondria. At variance, injection of these venoms in mice resulted in a different time-course of mtDNA release, with B. asper venom inducing an early onset increment in plasma levels and C. d. terrificus venom provoking a delayed release. We suggest that the release of mitochondrial 'alarmins' might contribute to the local and systemic inflammatory events characteristic of snakebite envenomations.

  14. Delay-dependent stability of neural networks of neutral type with time delay in the leakage term

    International Nuclear Information System (INIS)

    Li, Xiaodi; Cao, Jinde

    2010-01-01

    This paper studies the global asymptotic stability of neural networks of neutral type with mixed delays. The mixed delays include constant delay in the leakage term (i.e. 'leakage delay'), time-varying delays and continuously distributed delays. Based on the topological degree theory, Lyapunov method and linear matrix inequality (LMI) approach, some sufficient conditions are derived ensuring the existence, uniqueness and global asymptotic stability of the equilibrium point, which are dependent on both the discrete and distributed time delays. These conditions are expressed in terms of LMI and can be easily checked by the MATLAB LMI toolbox. Even if there is no leakage delay, the obtained results are less restrictive than some recent works. It can be applied to neural networks of neutral type with activation functions without assuming their boundedness, monotonicity or differentiability. Moreover, the differentiability of the time-varying delay in the non-neutral term is removed. Finally, two numerical examples are given to show the effectiveness of the proposed method

  15. Controlled release of Lactobacillus rhamnosus biofilm probiotics from alginate-locust bean gum microcapsules.

    Science.gov (United States)

    Cheow, Wean Sin; Kiew, Tie Yi; Hadinoto, Kunn

    2014-03-15

    Chitosan-coated alginate microcapsules containing high-density biofilm Lactobacillus rhamnosus have been previously shown to exhibit higher freeze drying- and thermal-tolerance than their planktonic counterparts. However, their cell release profile remains poor due to the capsules' susceptibility to the gastric environment. Herein the effects of adding locust bean (LB) and xanthan (XT) gums to alginate (AGN) capsules on the stress tolerance and cell release profiles in simulated gastrointestinal fluids are investigated. Compared to the AGN-only capsules, the AGN-LB capsules exhibit improved stress tolerance (i.e. ≈ 6x for freeze drying, 100x for thermotolerance, 10x for acid), whereas the AGN-XT capsules only improve the acid tolerance. Importantly, the AGN-LB capsules possess the optimal cell release profile with a majority of cells released in the simulated intestinal juice than in the gastric juice. The AGN-LB capsules' superiority is attributed to their stronger interaction with the chitosan coating and high swelling capacity, thus delaying their bulk dissolution. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Evaluation of Potential Drug-Drug Interaction Between Delayed-Release Dimethyl Fumarate and a Commonly Used Oral Contraceptive (Norgestimate/Ethinyl Estradiol) in Healthy Women.

    Science.gov (United States)

    Zhu, Bing; Nestorov, Ivan; Zhao, Guolin; Meka, Venkata; Leahy, Mark; Kam, Jeanelle; Sheikh, Sarah I

    2017-11-01

    Delayed-release dimethyl fumarate (DMF) is an oral therapy for relapsing multiple sclerosis with anti-inflammatory and neuroprotective properties. This 2-period crossover study was conducted to evaluate the potential for drug-drug interaction between DMF (240 mg twice daily) and a combined oral contraceptive (OC; norgestimate 250 μg, ethinyl estradiol 35 μg). Forty-six healthy women were enrolled; 32 completed the study. After the lead-in period (OC alone), 41 eligible participants were randomized 1:1 to sequence 1 (OC and DMF coadministration in period 1; OC alone in period 2) or sequence 2 (regimens reversed). Mean concentration profiles of plasma norelgestromin (primary metabolite of norgestimate) and ethinyl estradiol were superimposable following OC alone and OC coadministered with DMF, with 90% confidence intervals of geometric mean ratios for area under the plasma concentration-time curve over the dosing interval and peak plasma concentration contained within the 0.8-1.25 range. Low serum progesterone levels during combined treatment confirmed suppression of ovulation. The pharmacokinetics of DMF (measured via its primary active metabolite, monomethyl fumarate) were consistent with historical data when DMF was administered alone. No new safety concerns were identified. These results suggest that norgestimate/ethinyl estradiol-based OCs may be used with DMF without dose modification. © 2017, The Authors. Clinical Pharmacology in Drug Development Published by Wiley Periodicals, Inc. on behalf of The American College of Clinical Pharmacology.

  17. American Dream Delayed

    DEFF Research Database (Denmark)

    Khorunzhina, Natalia; Miller, Robert A.

    This paper investigates the delay in homeownership and a subsequent reduction in homeownership rate observed over the past decades. We focus on the delay in giving birth to children and increased labor market participation as contributing factors to homeownership dynamics for prime-age female hou...

  18. Prolactin modulates luteal activity in the short-nosed fruit bat, Cynopterus sphinx during delayed embryonic development.

    Science.gov (United States)

    Anuradha; Krishna, Amitabh

    2017-07-01

    The aim of this study was to evaluate the role of prolactin as a modulator of luteal steroidogenesis during the period of delayed embryonic development in Cynopterus sphinx. A marked decline in circulating prolactin levels was noted during the months of November through December coinciding with the period of decreased serum progesterone and delayed embryonic development. The seasonal changes in serum prolactin levels correlated positively with circulating progesterone (P) level, but inversely with circulating melatonin level during first pregnancy showing delayed development in Cynopterus sphinx. The results also showed decreased expression of prolactin receptor-short form (PRL-RS) both in the corpus luteum and in the utero-embryonic unit during the period of delayed embryonic development. Bats treated in vivo with prolactin during the period of delayed development showed significant increase in serum progesterone and estradiol levels together with significant increase in the expression of PRL-RS, luteinizing hormone receptor (LH-R), steroidogenic acute receptor protein (STAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) in the ovary. Prolactin stimulated ovarian angiogenesis (vascular endothelial growth factor) and cell survival (B-cell lymphoma 2) in vivo. Significant increases in ovarian progesterone production and the expression of prolactin-receptor, LH-R, STAR and 3β-HSD proteins were noted following the exposure of LH or prolactin in vitro during the delayed period. In conclusion, short-day associated increased melatonin level may be responsible for decreased prolactin release during November-December. The decline in prolactin level might play a role in suppressing P and estradiol-17β (E2) estradiol levels thereby causing delayed embryonic development in C. sphinx. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Delayed Orgasm and Anorgasmia

    OpenAIRE

    Jenkins, Lawrence C.; Mulhall, John P.

    2015-01-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies; which include: medications, penile sensation loss, endocrinopathies, penile hyperstimulation and psychological etiologies, amongst others. Unfortunately, ...

  20. Time-domain study of tectonic strain-release effects on seismic waves from underground nuclear explosions

    International Nuclear Information System (INIS)

    Nakanishi, K.K.; Sherman, N.W.

    1982-09-01

    Tectonic strain release affects both the amplitude and phase of seismic waves from underground nuclear explosions. Surface wave magnitudes are strongly affected by the component of tectonic strain release in the explosion. Amplitudes and radiation patterns of surface waves from explosions with even small tectonic components change magnitudes significantly and show a strong dependence on receiver locations. A thrust-slip source superimposed on an isotropic explosion can explain observed reversals in waveform at different azimuths and phase delays between normal and reversed Rayleigh waves. The mechanism of this reversal is due to the phase relationship between reasonable explosion and tectonic release sources. Spallation or an unusual source time function are not required. The observations of Shagan River events imply thrust-slip motion along faults in a northwest-southeast direction, which is consistent with regional tectonics

  1. Kisspeptin regulates ovarian steroidogenesis during delayed embryonic development in the fruit bat, Cynopterus sphinx.

    Science.gov (United States)

    Anuradha; Krishna, Amitabh

    2017-11-01

    Cynopterus sphinx, a fruit bat, undergoes delayed embryonic development during the winter months, a period that corresponds to low levels of progesterone and estradiol synthesis by the ovary. Kisspeptins (KPs) are a group of neuropeptide hormones that act via G-protein coupled receptor 54 (GPR54) to stimulate hypothalamic secretion of Gonadotropin-releasing hormone, thereby regulating ovarian steroidogenesis, folliculogenesis, and ovulation. GPR54 is also expressed in the ovary, suggesting a direct role for KPs in ovarian steroidogenesis. The aim of present study was to determine if a low serum level of KP is responsible for reduced progesterone and estradiol levels during the period of delayed embryonic development in C. sphinx. Indeed, low serum KP abundance corresponded to reduced expression of GPR54 in ovarian luteal cells during the period of delayed development compared to normal development. In vitro and in vivo treatment with KP increased GPR54 abundance, via Extracellular signal regulated kinase and its downstream mediators, leading to increased progesterone synthesis in the ovary during delayed embryonic development. KP treatment also increased cholesterol uptake and elevated expression of Luteinizing hormone receptor and Steroid acute regulatory protein in the ovary, suggesting that elevation in circulating KP during delayed embryonic development may reactivate luteal activity. KPs may also enhance cell survival (BCL-2, reduced Caspase 3 activity) and angiogenesis (Vascular endothelium growth factor) during this period. The findings of this study thus demonstrate a regulatory role for KPs in the maintenance of luteal steroidogenesis during pregnancy in C. sphinx. © 2017 Wiley Periodicals, Inc.

  2. Derivation and computation of discrete-delay and continuous-delay SDEs in mathematical biology.

    Science.gov (United States)

    Allen, Edward J

    2014-06-01

    Stochastic versions of several discrete-delay and continuous-delay differential equations, useful in mathematical biology, are derived from basic principles carefully taking into account the demographic, environmental, or physiological randomness in the dynamic processes. In particular, stochastic delay differential equation (SDDE) models are derived and studied for Nicholson's blowflies equation, Hutchinson's equation, an SIS epidemic model with delay, bacteria/phage dynamics, and glucose/insulin levels. Computational methods for approximating the SDDE models are described. Comparisons between computational solutions of the SDDEs and independently formulated Monte Carlo calculations support the accuracy of the derivations and of the computational methods.

  3. Attosecond Delays in Molecular Photoionization.

    Science.gov (United States)

    Huppert, Martin; Jordan, Inga; Baykusheva, Denitsa; von Conta, Aaron; Wörner, Hans Jakob

    2016-08-26

    We report measurements of energy-dependent photoionization delays between the two outermost valence shells of N_{2}O and H_{2}O. The combination of single-shot signal referencing with the use of different metal foils to filter the attosecond pulse train enables us to extract delays from congested spectra. Remarkably large delays up to 160 as are observed in N_{2}O, whereas the delays in H_{2}O are all smaller than 50 as in the photon-energy range of 20-40 eV. These results are interpreted by developing a theory of molecular photoionization delays. The long delays measured in N_{2}O are shown to reflect the population of molecular shape resonances that trap the photoelectron for a duration of up to ∼110 as. The unstructured continua of H_{2}O result in much smaller delays at the same photon energies. Our experimental and theoretical methods make the study of molecular attosecond photoionization dynamics accessible.

  4. Delayed Awakening from Anesthesia Following Electrolyte and Acid-Base Disorders, Two Cases

    Directory of Open Access Journals (Sweden)

    Razavi M

    2014-01-01

    Full Text Available Introduction: Delayed awakening from anesthesia remains one of the biggest challenges that involve anesthesiologists. Most commonly, delayed awakening is due to drugs effects persistence. Metabolic (like hypo- hyperglycemia, electrolyte, acid-base disorders and hypothermia may cause delayed emergence from anesthesia. Structural disorders of cerebral nervous system (like increase in intracranial pressure, brain ischemia and psychological disorders can be regarded as other uncommon causes of this condition. Hypokalemia is induced by low potassium intake, excessive excretion from gastrointestinal (GI and kidneys (like using diuretics or a shift from extracellular space into intracellular space. Cases:  In these two reported cases, although proper measures had been taken to reverse the effects of anesthetic drugs, the patients did not regain their consciousness as fast as expected. The only significant finding in postoperative tests, along with respiratory alkalosis, was low serum potassium level (K=2.5 and K=2.9 in the first and the second patients, respectively. Correction of serum potassium (to K=3.3 and K=3.2 in the first and the second, respectively improved patients level of consciousness, and they were discharged from intensive care unit (ICU with good general condition. Conclusion: During surgery; pain, stress, sympathetic increase, catecholamine release and the consequent β-stimulation, certain drugs, and respiratory alkalosis due to hyperventilation may cause acute shift of potassium into the cells, which will be intensified in the patients with preoperative hypokalemia. Hypokalemia induces consciousness impairment and increases muscle relaxation, both of which affect patient awakening. Serum potassium evaluation is recommended in cases of delayed emergence from anesthesia.

  5. Virtual unit delay for digital frequency adaptive T/4 delay phase-locked loop system

    DEFF Research Database (Denmark)

    Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede

    2016-01-01

    /processor with a fixed sampling rate considering the cost and complexity, where the number of unit delays that have been adopted should be an integer. For instance, in conventional digital control systems, a single-phase T/4 Delay Phase-Locked Loop (PLL) system takes 50 unit delays (i.e., in a 50-Hz system...... Delay PLL system should be done in its implementation. This process will result in performance degradation in the digital control system, as the exactly required number of delays is not realized. Hence, in this paper, a Virtual Unit Delay (VUD) has been proposed to address such challenges to the digital......Digital micro-controllers/processors enable the cost-effective control of grid-connected power converter systems in terms of system monitoring, signal processing (e.g., grid synchronization), control (e.g., grid current and voltage control), etc. Normally, the control is implemented in a micro-controller...

  6. Suppressing Resistance to Bt Cotton with Sterile Insect Releases

    Energy Technology Data Exchange (ETDEWEB)

    Tabashnik, B E [Department of Entomology, University of Arizona, Tucson, AZ (United States); Sisterson, M S [USDA-ARS, San Joaquin Valley Agricultural Sciences Center, Parlier, CA (United States); Ellsworth, P C [Department of Entomology, University of Arizona, Maricopa Agricultural Center, Maricopa, AZ (United States)

    2011-01-15

    Genetically engineered crops that produce insecticidal toxins from Bacillus thuringiensis (Bt) are grown widely for pest control. However, insect adaptation can reduce the toxins' efficacy. The predominant strategy for delaying pest resistance to Bt crops requires refuges of non-Bt host plants to provide susceptible insects to mate with resistant insects. Variable farmer compliance is one of the limitations of this approach. Here we report the benefits of an alternative strategy where sterile insects are released to mate with resistant insects and refuges are scarce or absent. Computer simulations show that this approach works in principle against pests with recessive or dominant inheritance of resistance. During a largescale, four-year field deployment of this strategy in Arizona, resistance of pink bollworm (Pectinophora gossypiella) to Bt cotton did not increase. A multitactic eradication program that included the release of sterile moths reduced pink bollworm abundance by >99%, while eliminating insecticide sprays against this key invasive pest. (author)

  7. Information transfer via implicit encoding with delay time modulation in a time-delay system

    Energy Technology Data Exchange (ETDEWEB)

    Kye, Won-Ho, E-mail: whkye@kipo.go.kr [Korean Intellectual Property Office, Government Complex Daejeon Building 4, 189, Cheongsa-ro, Seo-gu, Daejeon 302-701 (Korea, Republic of)

    2012-08-20

    A new encoding scheme for information transfer with modulated delay time in a time-delay system is proposed. In the scheme, the message is implicitly encoded into the modulated delay time. The information transfer rate as a function of encoding redundancy in various noise scales is presented and it is analyzed that the implicit encoding scheme (IES) has stronger resistance against channel noise than the explicit encoding scheme (EES). In addition, its advantages in terms of secure communication and feasible applications are discussed. -- Highlights: ► We propose new encoding scheme with delay time modulation. ► The message is implicitly encoded with modulated delay time. ► The proposed scheme shows stronger resistance against channel noise.

  8. Mechanochemical effect on swelling and drug release of natural polymer matrix tablets by X-ray computed tomography.

    Science.gov (United States)

    Hattori, Yusuke; Takaku, Tomomi; Otsuka, Makoto

    2018-03-25

    The relationships between the physicochemical properties of milled starch and drug release from tablets were investigated quantitatively using a drug release kinetic method and X-ray computed tomography (XCT). The samples were prepared from raw β-starch by milling in a planetary ball mill. The tablets, containing 5% theophylline (TH), 94% milled starch, and 1% magnesium stearate, were compressed at 6 kN. The drug-release and gel-forming processes were measured simultaneously using an original dissolution tester with an XCT instrument. Drug release from the tablet was delayed with increasing milling time, because the TH tablet formed a typical gel-layer on the outside of the tablet. The relationship between the crystallinity of milled starch and mean drug release time (MDT) for the TH tablets showed almost a straight inverse proportional relationship. The plots of MDT against area under the curve of the swelling ratio profiles of the TH tablets had a good straight line. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Stress- and sequence-dependent release into the culture medium of HIV-1 Nef produced in Saccharomyces cerevisiae.

    Science.gov (United States)

    Macreadie, I G; Castelli, L A; Lucantoni, A; Azad, A A

    1995-09-11

    We have produced human immunodeficiency virus type 1 (HIV-1) Nef (a myristylated 206-amino-acid protein) in Saccharomyces cerevisaie and shown that, while Nef is normally found as a predominantly intracellular protein, amounts up to 40 micrograms/ml of Nef are also released into the extracellular medium during stress. By electrophoretic (SDS-PAGE) analysis the extracellular Nef is indistinguishable from intracellular Nef. Conditions of stress that lead to the release of Nef include elevated levels of copper or magnesium ions or growth at elevated temperatures. This release appears to be dependent upon the N-terminal sequences of Nef, including the presence of a myristylation site. Our observations concerning Nef release in yeast suggest new ways in which the behaviour of Nef should be examined in order to gain further insights into the development of AIDS. If the release of Nef is important in the development of AIDS, our work reveals that Nef-associated symptoms may be reduced or delayed by reducing stresses, such as fevers.

  10. Impulsive control of time-delay systems using delayed impulse and its application to impulsive master-slave synchronization

    International Nuclear Information System (INIS)

    Sun Jitao; Han Qinglong; Jiang Xiefu

    2008-01-01

    This Letter is concerned with impulsive control of a class of nonlinear time-delay systems. Some uniform stability criteria for the closed-loop time-delay system under delayed impulsive control are derived by using piecewise Lyapunov functions. Then the criteria are applied to impulsive master-slave synchronization of some secure communication systems with transmission delays and sample delays under delayed impulsive control. Two numerical examples are given to illustrate the effectiveness of the derived results

  11. Psilocybin dose-dependently causes delayed, transient headaches in healthy volunteers.

    Science.gov (United States)

    Johnson, Matthew W; Sewell, R Andrew; Griffiths, Roland R

    2012-06-01

    Psilocybin is a well-characterized classic hallucinogen (psychedelic) with a long history of religious use by indigenous cultures, and nonmedical use in modern societies. Although psilocybin is structurally related to migraine medications, and case studies suggest that psilocybin may be efficacious in treatment of cluster headache, little is known about the relationship between psilocybin and headache. This double-blind study examined a broad range of psilocybin doses (0, 5, 10, 20, and 30 mg/70 kg) on headache in 18 healthy participants. Psilocybin frequently caused headache, the incidence, duration, and severity of which increased in a dose-dependent manner. All headaches had delayed onset, were transient, and lasted no more than a day after psilocybin administration. Possible mechanisms for these observations are discussed, and include induction of delayed headache through nitric oxide release. These data suggest that headache is an adverse event to be expected with the nonmedical use of psilocybin-containing mushrooms as well as the administration of psilocybin in human research. Headaches were neither severe nor disabling, and should not present a barrier to future psilocybin research. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. Prehospital delay in acute coronary syndrome--an analysis of the components of delay

    DEFF Research Database (Denmark)

    Ottesen, Michael Mundt; Dixen, Ulrik; Torp-Pedersen, Christian

    2004-01-01

    BACKGROUND: Prompt hospital admission is essential when treating acute coronary syndrome. Delay prior to admission is unnecessarily long. Therefore, a thorough scrutiny of the influence of characteristics, circumstantial and subjective variables on elements of prehospital delay among patients...... admitted with acute coronary syndrome is warranted. METHODS: A structured interview was conducted on 250 consecutive patients admitted alive with acute coronary syndrome. RESULTS: Median prehospital, decision, physician and transportation delays were 107, 74, 25 and 22 min, respectively. Women (n=77) had...... of acute coronary syndrome among women, and thereby contributes to unnecessary long delay to treatment. The patient's prior experience and interpretation has a significant influence on behaviour....

  13. Communication key using delay times in time-delayed chaos synchronization

    International Nuclear Information System (INIS)

    Kim, Chil-Min; Kye, Won-Ho; Rim, Sunghwan; Lee, Soo-Young

    2004-01-01

    We propose an efficient key scheme, which can generate a great number of communication keys, for communication using chaos synchronization. We have attained the keys from delay times of time-delay coupled chaotic systems. We explain the scheme and the efficiency by coupling Henon and logistic maps and illustrate them by coupling Navier-Stokes and Lorenz equations as a continuous system

  14. Patient delay is the main cause of treatment delay in acute limb ischemia: an investigation of pre- and in-hospital time delay

    DEFF Research Database (Denmark)

    Londero, Louise Skovgaard; Nørgaard, Birgitte; Houlind, Kim Christian

    2014-01-01

    Abstract BACKGROUND: The prognosis of acute limb ischemia is severe, with amputation rates of up to 25% and in-hospital mortality of 9-15%. Delay in treatment increases the risk of major amputation and may be present at different stages, including patient delay, doctors´ delay and waiting time...... in the emergency department. It is important to identify existing problems in order to reduce time delay. The aim of this study was to collect data for patients with acute limb ischemia and to evaluate the time delay between the different events from onset of symptoms to specialist evaluation and further treatment...... (median (range)) was identified. From onset of symptoms to first contact with a doctor the time for all patients were 24 (0-1200) hours. Thirty patients needed immediate intervention. In the group of fourteen patients who had immediate operation, the median time from vascular evaluation...

  15. Vehicle barrier with access delay

    Science.gov (United States)

    Swahlan, David J; Wilke, Jason

    2013-09-03

    An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

  16. [The application of delayed skin grafting combined traction in severe joint cicatricial contracture].

    Science.gov (United States)

    Xu, Zihan; Zhang, Zhenxin; Wang, Benfeng; Sun, Yaowen; Guo, Yadong; Gao, Wenjie; Qin, Gaoping

    2014-11-01

    To investigate the effect of delayed skin grafting combined traction in severe joint cicatricial contracture. At the first stage, the joint cicatricial contracture was released completely with protection of vessels, nerves and tendons. The wound was covered with allogenetic skin or biomaterials. After skin traction for 7-14 days, the joint could reach the extension position. Then the skin graft was performed on the wound. 25 cases were treated from Mar. 2000 to May. 2013. Primary healing was achieved at the second stage in all the cases. The skin graft had a satisfactory color and elasticity. Joint function was normal. All the patients were followed up for 3 months to 11 years with no hypertrophic scar and contraction relapse, except for one case who didn' t have enough active exercise on shoulder joint. Delayed skin grafting combined traction can effectively increase the skin graft survival rate and improve the joint function recovery.

  17. Lithium ceramics: sol-gel preparation and tritium release

    International Nuclear Information System (INIS)

    Renoult, O.

    1994-04-01

    Ceramics based on lithium aluminate (LiA1O 2 ), lithium zirconate (Li 2 ZrO 3 ) and lithium titanate (Li 2 TiO 3 ) are candidates as tritium breeder blanket materials for forthcoming nuclear fusion reactors. Lithium silico-aluminate Li 4+x A1 4-3x Si 2x O 8 (0 ≤ x ≤ 0,25) powders were synthetized from alkoxyde-hydroxyde sol-gel route. By direct sintering at 850-1100 deg C (without prior calcination), ceramics with controlled stoichiometry and homogenous microstructure were obtained. We have also prepared, using a comparable method, Li 2 Zr 1-x Ti x O 3 (x = 0, x = 0,1 et x = 1) materials. All these ceramics, with different microstructures and compositions, have been tested in out-of-reactor experiments. Concerning lithium aluminate microporous ceramics, the silicon substitution leads to a significant improvement of the tritrium release. Classical models taking into account independent surface mechanisms are not able to describe correctly the observed tritium release kinetics. We show, using a simple model, that the release kinetics is in fact limited by an intergranular diffusion followed by a desorption. The delay in tritium release, which occurs when the ceramic compacity increases, is explained in terms of an enhancement of the ionic T + diffusion path length. The energy required for desorption includes a leading term independent of hydrogen contained in the sweep gas. This term is attributed to the limiting recombination step of T + in molecular species HTO. For similar microstructures, the facility of tritium release for the different studied materials is explained by three properties: the crystal structure of the ceramic, the acidity of oxides and finally the presence of electronic non-stoichiometric defects. (author). 89 refs., 50 figs., 2 tabs., 1 annexe

  18. Precise delay measurement through combinatorial logic

    Science.gov (United States)

    Burke, Gary R. (Inventor); Chen, Yuan (Inventor); Sheldon, Douglas J. (Inventor)

    2010-01-01

    A high resolution circuit and method for facilitating precise measurement of on-chip delays for FPGAs for reliability studies. The circuit embeds a pulse generator on an FPGA chip having one or more groups of LUTS (the "LUT delay chain"), also on-chip. The circuit also embeds a pulse width measurement circuit on-chip, and measures the duration of the generated pulse through the delay chain. The pulse width of the output pulse represents the delay through the delay chain without any I/O delay. The pulse width measurement circuit uses an additional asynchronous clock autonomous from the main clock and the FPGA propagation delay can be displayed on a hex display continuously for testing purposes.

  19. Improving Delay-Range-Dependent Stability Condition for Systems with Interval Time-Varying Delay

    Directory of Open Access Journals (Sweden)

    Wei Qian

    2013-01-01

    Full Text Available This paper discusses the delay-range-dependent stability for systems with interval time-varying delay. Through defining the new Lyapunov-Krasovskii functional and estimating the derivative of the LKF by introducing new vectors, using free matrices and reciprocally convex approach, the new delay-range-dependent stability conditions are obtained. Two well-known examples are given to illustrate the less conservatism of the proposed theoretical results.

  20. Effects of acute and sub-acute gamma radiation on photosynthetic release and respiration of three unicellular marine algae

    Energy Technology Data Exchange (ETDEWEB)

    Ehrhardt, J P

    1974-12-31

    Thesis. Lethal doses of irradiation are required before a 50% inactivation of the photosynthetic release is achieved. The chloroplasts, after this treatment, are one and a half times more resistant than the nucleus. The delayed effect is irreversible when it corresponds to a dose in excess of that necessary for the immediate 10% inhibition of the photosynthetic release. A decrease is observed in the respiration during several days after the occurrence of an intermediate increase. This behavior may be considered to be a consequence of the irreversible destruction of the mitochondrial sites. (FR)

  1. Modeling of delays in PKPD: classical approaches and a tutorial for delay differential equations.

    Science.gov (United States)

    Koch, Gilbert; Krzyzanski, Wojciech; Pérez-Ruixo, Juan Jose; Schropp, Johannes

    2014-08-01

    In pharmacokinetics/pharmacodynamics (PKPD) the measured response is often delayed relative to drug administration, individuals in a population have a certain lifespan until they maturate or the change of biomarkers does not immediately affects the primary endpoint. The classical approach in PKPD is to apply transit compartment models (TCM) based on ordinary differential equations to handle such delays. However, an alternative approach to deal with delays are delay differential equations (DDE). DDEs feature additional flexibility and properties, realize more complex dynamics and can complementary be used together with TCMs. We introduce several delay based PKPD models and investigate mathematical properties of general DDE based models, which serve as subunits in order to build larger PKPD models. Finally, we review current PKPD software with respect to the implementation of DDEs for PKPD analysis.

  2. A delay fractioning approach to global synchronization of delayed complex networks with stochastic disturbances

    International Nuclear Information System (INIS)

    Wang Yao; Wang Zidong; Liang Jinling

    2008-01-01

    In this Letter, the synchronization problem is investigated for a class of stochastic complex networks with time delays. By utilizing a new Lyapunov functional form based on the idea of 'delay fractioning', we employ the stochastic analysis techniques and the properties of Kronecker product to establish delay-dependent synchronization criteria that guarantee the globally asymptotically mean-square synchronization of the addressed delayed networks with stochastic disturbances. These sufficient conditions, which are formulated in terms of linear matrix inequalities (LMIs), can be solved efficiently by the LMI toolbox in Matlab. The main results are proved to be much less conservative and the conservatism could be reduced further as the number of delay fractioning gets bigger. A simulation example is exploited to demonstrate the advantage and applicability of the proposed result

  3. A distributed delay approach for modeling delayed outcomes in pharmacokinetics and pharmacodynamics studies.

    Science.gov (United States)

    Hu, Shuhua; Dunlavey, Michael; Guzy, Serge; Teuscher, Nathan

    2018-04-01

    A distributed delay approach was proposed in this paper to model delayed outcomes in pharmacokinetics and pharmacodynamics studies. This approach was shown to be general enough to incorporate a wide array of pharmacokinetic and pharmacodynamic models as special cases including transit compartment models, effect compartment models, typical absorption models (either zero-order or first-order absorption), and a number of atypical (or irregular) absorption models (e.g., parallel first-order, mixed first-order and zero-order, inverse Gaussian, and Weibull absorption models). Real-life examples were given to demonstrate how to implement distributed delays in Phoenix ® NLME™ 8.0, and to numerically show the advantages of the distributed delay approach over the traditional methods.

  4. Novel delay-distribution-dependent stability analysis for continuous-time recurrent neural networks with stochastic delay

    International Nuclear Information System (INIS)

    Wang Shen-Quan; Feng Jian; Zhao Qing

    2012-01-01

    In this paper, the problem of delay-distribution-dependent stability is investigated for continuous-time recurrent neural networks (CRNNs) with stochastic delay. Different from the common assumptions on time delays, it is assumed that the probability distribution of the delay taking values in some intervals is known a priori. By making full use of the information concerning the probability distribution of the delay and by using a tighter bounding technique (the reciprocally convex combination method), less conservative asymptotic mean-square stable sufficient conditions are derived in terms of linear matrix inequalities (LMIs). Two numerical examples show that our results are better than the existing ones. (general)

  5. Histamine release from gut mast cells from patients with inflammatory bowel diseases

    DEFF Research Database (Denmark)

    Nolte, Hendrik; Spjeldnæs, Nikolaj; Kruse, Aksel

    1990-01-01

    Inflammatory mediators from intestinal mast cells may serve as initiators of acute and delayed inflammation. Mast cell histamine release was measured in 19 patients with inflammatory bowel diseases using gut mast cells from enzymatically dispersed endoscopic forceps biopsy specimens...... of macroscopically inflamed and normal tissue. Mast cells and corresponding basophils were challenged with anti-IgE, anti-IgG, subclass anti-IgG4, and formyl-methionyl-leucyl-phenylalanine (FMLP) and results were compared with those from nine patient control subjects. The mast cell count in patients with ulcerative...... colitis was increased compared with that in control subjects and patients with Crohn's disease, and the mast cell count obtained from inflamed tissue was greater than that of normal tissue. The study also shows the heterogeneity of the responsiveness of the histamine releasing cells to various...

  6. Fission product release modelling for application of fuel-failure monitoring and detection - An overview

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, B.J., E-mail: lewibre@gmail.com [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, K7K 7B4 (Canada); Chan, P.K.; El-Jaby, A. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, K7K 7B4 (Canada); Iglesias, F.C.; Fitchett, A. [Candesco Division of Kinectrics Inc., 26 Wellington Street East, 3rd Floor, Toronto, Ontario M5E 1S2 (Canada)

    2017-06-15

    A review of fission product release theory is presented in support of fuel-failure monitoring analysis for the characterization and location of defective fuel. This work is used to describe: (i) the development of the steady-state Visual-DETECT code for coolant activity analysis to characterize failures in the core and the amount of tramp uranium; (ii) a generalization of this model in the STAR code for prediction of the time-dependent release of iodine and noble gas fission products to the coolant during reactor start-up, steady-state, shutdown, and bundle-shifting manoeuvres; (iii) an extension of the model to account for the release of fission products that are delayed-neutron precursors for assessment of fuel-failure location; and (iv) a simplification of the steady-state model to assess the methodology proposed by WANO for a fuel reliability indicator for water-cooled reactors.

  7. Time Delay of CGM Sensors

    Science.gov (United States)

    Schmelzeisen-Redeker, Günther; Schoemaker, Michael; Kirchsteiger, Harald; Freckmann, Guido; Heinemann, Lutz; del Re, Luigi

    2015-01-01

    Background: Continuous glucose monitoring (CGM) is a powerful tool to support the optimization of glucose control of patients with diabetes. However, CGM systems measure glucose in interstitial fluid but not in blood. Rapid changes in one compartment are not accompanied by similar changes in the other, but follow with some delay. Such time delays hamper detection of, for example, hypoglycemic events. Our aim is to discuss the causes and extent of time delays and approaches to compensate for these. Methods: CGM data were obtained in a clinical study with 37 patients with a prototype glucose sensor. The study was divided into 5 phases over 2 years. In all, 8 patients participated in 2 phases separated by 8 months. A total number of 108 CGM data sets including raw signals were used for data analysis and were processed by statistical methods to obtain estimates of the time delay. Results: Overall mean (SD) time delay of the raw signals with respect to blood glucose was 9.5 (3.7) min, median was 9 min (interquartile range 4 min). Analysis of time delays observed in the same patients separated by 8 months suggests a patient dependent delay. No significant correlation was observed between delay and anamnestic or anthropometric data. The use of a prediction algorithm reduced the delay by 4 minutes on average. Conclusions: Prediction algorithms should be used to provide real-time CGM readings more consistent with simultaneous measurements by SMBG. Patient specificity may play an important role in improving prediction quality. PMID:26243773

  8. Delay-Dependent Guaranteed Cost Control of an Interval System with Interval Time-Varying Delay

    Directory of Open Access Journals (Sweden)

    Xiao Min

    2009-01-01

    Full Text Available This paper concerns the problem of the delay-dependent robust stability and guaranteed cost control for an interval system with time-varying delay. The interval system with matrix factorization is provided and leads to less conservative conclusions than solving a square root. The time-varying delay is assumed to belong to an interval and the derivative of the interval time-varying delay is not a restriction, which allows a fast time-varying delay; also its applicability is broad. Based on the Lyapunov-Ktasovskii approach, a delay-dependent criterion for the existence of a state feedback controller, which guarantees the closed-loop system stability, the upper bound of cost function, and disturbance attenuation lever for all admissible uncertainties as well as out perturbation, is proposed in terms of linear matrix inequalities (LMIs. The criterion is derived by free weighting matrices that can reduce the conservatism. The effectiveness has been verified in a number example and the compute results are presented to validate the proposed design method.

  9. Delay-Dependent Control for Networked Control Systems with Large Delays

    Directory of Open Access Journals (Sweden)

    Yilin Wang

    2013-01-01

    Full Text Available We consider the problems of robust stability and control for a class of networked control systems with long-time delays. Firstly, a nonlinear discrete time model with mode-dependent time delays is proposed by converting the uncertainty of time delay into the uncertainty of parameter matrices. We consider a probabilistic case where the system is switched among different subsystems, and the probability of each subsystem being active is defined as its occurrence probability. For a switched system with a known subsystem occurrence probabilities, we give a stochastic stability criterion in terms of linear matrix inequalities (LMIs. Then, we extend the results to a more practical case where the subsystem occurrence probabilities are uncertain. Finally, a simulation example is presented to show the efficacy of the proposed method.

  10. Quad nanosecond delay module

    International Nuclear Information System (INIS)

    McDonald, R.J.; Hunter, J.B.; Wozniak, G.J.

    1986-04-01

    Four nanosecond (ns) delay units have been designed to fit in a single-width NIM module. This module is particularly suited for use in conjunction with quad constant fraction timing discriminators (CFTDs) since it has four delay units that can be placed adjacent to the four units of the CFTD. A series of different length cables connected via DIP toggle switches provide delays of 0.60 ns in 4 ns increments. Thus, the CFTD delay can be optimized for pulses of different rise times from approx.10-100 ns. Design work for the PC board and silkscreening of the front panel were done with the MacDraw program on the Apple Mackintosh computer and printed with the Lasewriter printer. 6 refs

  11. Mechanisms of Broad-Spectrum Antiemetic Efficacy of Cannabinoids against Chemotherapy-Induced Acute and Delayed Vomiting

    Directory of Open Access Journals (Sweden)

    Nissar A. Darmani

    2010-09-01

    Full Text Available Chemotherapy-induced nausea and vomiting (CINV is a complex pathophysiological condition and consists of two phases. The conventional CINV neurotransmitter hypothesis suggests that the immediate phase is mainly due to release of serotonin (5-HT from the enterochromaffin cells in the gastrointestinal tract (GIT, while the delayed phase is a consequence of release of substance P (SP in the brainstem. However, more recent findings argue against this simplistic neurotransmitter and anatomical view of CINV. Revision of the hypothesis advocates a more complex, differential and overlapping involvement of several emetic neurotransmitters/modulators (e.g. dopamine, serotonin, substance P, prostaglandins and related arachidonic acid derived metabolites in both phases of emesis occurring concomitantly in the brainstem and in the GIT enteric nervous system (ENS [1]. No single antiemetic is currently available to completely prevent both phases of CINV. The standard antiemetic regimens include a 5-HT3 antagonist plus dexamethasone for the prevention of acute emetic phase, combined with an NK1 receptor antagonist (e.g. aprepitant for the delayed phase. Although NK1 antagonists behave in animals as broad-spectrum antiemetics against different emetogens including cisplatin-induced acute and delayed vomiting, by themselves they are not very effective against CINV in cancer patients. Cannabinoids such as D9-THC also behave as broad-spectrum antiemetics against diverse emetic stimuli as well as being effective against both phases of CINV in animals and patients. Potential side effects may limit the clinical utility of direct-acting cannabinoid agonists which could be avoided by the use of corresponding indirect-acting agonists. Cannabinoids (both phyto-derived and synthetic behave as agonist antiemetics via the activation of cannabinoid CB1 receptors in both the brainstem and the ENS emetic loci. An endocannabinoid antiemetic tone may exist since inverse CB1

  12. Intrathecal application of the nimodipine slow-release microparticle system eg-1962 for prevention of delayed cerebral ischemia and improvement of outcome after aneurysmal subarachnoid hemorrhage.

    Science.gov (United States)

    Etminan, Nima; Macdonald, R Loch; Davis, Cara; Burton, Kevin; Steiger, Hans-Jakob; Hänggi, Daniel

    2015-01-01

    The effective reduction of delayed cerebral ischemia (DCI), a main contributor for poor outcome following aneurysmal subarachnoid hemorrhage (SAH), remains challenging. Previous clinical trials on systemic pharmaceutical treatment of SAH mostly failed to improve outcome, probably because of insensitive pharmaceutical targets and outcome measures, small sample size, insufficient subarachnoid drug concentrations and also detrimental, systemic effects of the experimental treatment per se. Interestingly, in studies that are more recent, intrathecal administration of nicardipine pellets following surgical aneurysm repair was suggested to have a beneficial effect on DCI and neurological outcome. However, this positive effect remained restricted to patients who were treated surgically for a ruptured aneurysm. Because of the favorable results of the preclinical data on DCI and neurological outcome in the absence of neurotoxicity or systemic side effects, we are initiating clinical trials. The PROMISE (Prolonged Release nimOdipine MIcro particles after Subarachnoid hemorrhage) trial is designed as an unblinded, nonrandomized, single-center, single-dose, dose-escalation safety and tolerability phase 1 study in patients surgically treated for aSAH and will investigate the effect of intracisternal EG-1962 administration. The NEWTON (Nimodipine microparticles to Enhance recovery While reducing TOxicity after subarachNoid hemorrhage) trial is a phase 1/2a multicenter, controlled, randomized, open-label, dose-escalation, safety, tolerability, and pharmacokinetic study comparing EG-1962 and nimodipine in patients with aneurysmal SAH.

  13. The SDSS-III DR12 MARVELS radial velocity data release: the first data release from the multiple object Doppler exoplanet survey

    Science.gov (United States)

    Ge, Jian; Thomas, Neil B.; Li, Rui; Senan Seieroe Grieves, Nolan; Ma, Bo; de Lee, Nathan M.; Lee, Brian C.; Liu, Jian; Bolton, Adam S.; Thakar, Aniruddha R.; Weaver, Benjamin; SDSS-Iii Marvels Team

    2015-01-01

    We present the first data release from the SDSS-III Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS) through the SDSS-III DR12. The data include 181,198 radial velocity (RV) measurements for a total of 5520 different FGK stars with V~7.6-12, of which more than 80% are dwarfs and subdwarfs while remainders are GK giants, among a total of 92 fields nearly randomly spread out over the entire northern sky taken with a 60-object MARVELS dispersed fixed-delay interferometer instrument over four years (2008-2012). There were 55 fields with a total of 3300 FGK stars which had 14 or more observations over about 2-year survey window. The median number of observations for these plates is 27 RV measurements. This represents the largest homogeneous sample of precision RV measurements of relatively bright stars. In this first released data, a total of 18 giant planet candidates, 16 brown dwarfs, and over 500 binaries with additional 96 targets having RV variability indicative of a giant planet companion are reported. The released data were produced by the MARVELS finalized 1D pipeline. We will also report preliminary statistical results from the MARVELS 2D data pipeline which has produced a median RV precision of ~30 m/s for stable stars.

  14. UAVs and Control Delays

    National Research Council Canada - National Science Library

    de Vries, S. C

    2005-01-01

    .... Delays of about 250-300 ms often lead to unacceptable airplane handling qualities. Techniques such as filtering and predictive displays may extend the range of acceptable delays up to about 400 ms...

  15. Analytical applications for delayed neutrons

    International Nuclear Information System (INIS)

    Eccleston, G.W.

    1983-01-01

    Analytical formulations that describe the time dependence of neutron populations in nuclear materials contain delayed-neutron dependent terms. These terms are important because the delayed neutrons, even though their yields in fission are small, permit control of the fission chain reaction process. Analytical applications that use delayed neutrons range from simple problems that can be solved with the point reactor kinetics equations to complex problems that can only be solved with large codes that couple fluid calculations with the neutron dynamics. Reactor safety codes, such as SIMMER, model transients of the entire reactor core using coupled space-time neutronics and comprehensive thermal-fluid dynamics. Nondestructive delayed-neutron assay instruments are designed and modeled using a three-dimensional continuous-energy Monte Carlo code. Calculations on high-burnup spent fuels and other materials that contain a mix of uranium and plutonium isotopes require accurate and complete information on the delayed-neutron periods, yields, and energy spectra. A continuing need exists for delayed-neutron parameters for all the fissioning isotopes

  16. Impact of food, alcohol and pH on modified-release hydrocortisone developed to treat congenital adrenal hyperplasia.

    Science.gov (United States)

    Karunasena, Nayananjani; Margetson, Daniel N; Neal, Greg; Whitaker, Martin J; Ross, Richard Jm

    2017-04-01

    We developed a modified-release hydrocortisone, Chronocort, to replace the cortisol rhythm in patients with congenital adrenal hyperplasia. Food, alcohol and pH affect drug absorption, and it is important to assess their impact when replicating a physiological rhythm. In vitro dissolution to study impact of alcohol and pH on Chronocort. A phase 1, three-period, cross over study in 18 volunteers to assess the impact of food on Chronocort and to compare bioavailability to immediate-release hydrocortisone. In vitro dissolution of Chronocort was not affected by gastrointestinal pH up to 6.0 nor by an alcohol content up to 20% v/v. Food delayed and reduced the rate of absorption of Chronocort as reflected by a longer T max (fed vs fasted: 6.75 h vs 4.5 h, P  = 0005) and lower C max (549.49 nmol/L vs 708.46 nmol/L, ratio 77% with CI 71-85). Cortisol exposure was similar in fed and fasted state: Geo LSmean ratio (CI) AUC 0t for fed/fasted was 108.33% (102.30-114.72%). Cortisol exposure was higher for Chronocort compared to immediate-release hydrocortisone: Geo LSmean ratios (CI) 118.83% (111.58-126.54%); however, derived free cortisol showed cortisol exposure CIs were within 80.0-125.0%: Geo LSmean ratio (CI) for AUC 0t 112.73% (105.33-120.65%). Gastric pH ≤6.0 and alcohol do not affect hydrocortisone release from Chronocort. Food delays Chronocort absorption, but cortisol exposure is similar in the fasted and fed state and exposure as assessed by free cortisol is similar between Chronocort and immediate-release hydrocortisone. © 2017 The authors.

  17. 49 CFR 236.563 - Delay time.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

  18. Delayed puberty in boys

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/007695.htm Delayed puberty in boys To use the sharing features on this page, please enable JavaScript. Delayed puberty in boys is when puberty does not begin ...

  19. Delay-range-dependent exponential H∞ synchronization of a class of delayed neural networks

    International Nuclear Information System (INIS)

    Karimi, Hamid Reza; Maass, Peter

    2009-01-01

    This article aims to present a multiple delayed state-feedback control design for exponential H ∞ synchronization problem of a class of delayed neural networks with multiple time-varying discrete delays. On the basis of the drive-response concept and by introducing a descriptor technique and using Lyapunov-Krasovskii functional, new delay-range-dependent sufficient conditions for exponential H ∞ synchronization of the drive-response structure of neural networks are driven in terms of linear matrix inequalities (LMIs). The explicit expression of the controller gain matrices are parameterized based on the solvability conditions such that the drive system and the response system can be exponentially synchronized. A numerical example is included to illustrate the applicability of the proposed design method.

  20. New Results on Passivity Analysis of Stochastic Neural Networks with Time-Varying Delay and Leakage Delay

    Directory of Open Access Journals (Sweden)

    YaJun Li

    2015-01-01

    Full Text Available The passivity problem for a class of stochastic neural networks systems (SNNs with varying delay and leakage delay has been further studied in this paper. By constructing a more effective Lyapunov functional, employing the free-weighting matrix approach, and combining with integral inequality technic and stochastic analysis theory, the delay-dependent conditions have been proposed such that SNNs are asymptotically stable with guaranteed performance. The time-varying delay is divided into several subintervals and two adjustable parameters are introduced; more information about time delay is utilised and less conservative results have been obtained. Examples are provided to illustrate the less conservatism of the proposed method and simulations are given to show the impact of leakage delay on stability of SNNs.

  1. Discounting of Monetary Rewards that are Both Delayed and Probabilistic: Delay and Probability Combine Multiplicatively, not Additively

    Science.gov (United States)

    Vanderveldt, Ariana; Green, Leonard; Myerson, Joel

    2014-01-01

    The value of an outcome is affected both by the delay until its receipt (delay discounting) and by the likelihood of its receipt (probability discounting). Despite being well-described by the same hyperboloid function, delay and probability discounting involve fundamentally different processes, as revealed, for example, by the differential effects of reward amount. Previous research has focused on the discounting of delayed and probabilistic rewards separately, with little research examining more complex situations in which rewards are both delayed and probabilistic. In two experiments, participants made choices between smaller rewards that were both immediate and certain and larger rewards that were both delayed and probabilistic. Analyses revealed significant interactions between delay and probability factors inconsistent with an additive model. In contrast, a hyperboloid discounting model in which delay and probability were combined multiplicatively provided an excellent fit to the data. These results suggest that the hyperboloid is a good descriptor of decision making in complicated monetary choice situations like those people encounter in everyday life. PMID:24933696

  2. Comparative steady-state pharmacokinetic study of an extended-release formulation of itopride and its immediate-release reference formulation in healthy volunteers.

    Science.gov (United States)

    Yoon, Seonghae; Lee, Howard; Kim, Tae-Eun; Lee, SeungHwan; Chee, Dong-Hyun; Cho, Joo-Youn; Yu, Kyung-Sang; Jang, In-Jin

    2014-01-01

    This study was conducted to compare the oral bioavailability of an itopride extended-release (ER) formulation with that of the reference immediate-release (IR) formulation in the fasting state. The effect of food on the bioavailability of itopride ER was also assessed. A single-center, open-label, randomized, multiple-dose, three-treatment, three-sequence, crossover study was performed in 24 healthy male subjects, aged 22-48 years, who randomly received one of the following treatments for 4 days in each period: itopride 150 mg ER once daily under fasting or fed conditions, or itopride 50 mg IR three times daily in the fasting state. Steady-state pharmacokinetic parameters of itopride, including peak plasma concentration (Cmax) and area under the plasma concentration versus time curve over 24 hours after dosing (AUC(0-24h)), were determined by noncompartmental analysis. The geometric mean ratio of the pharmacokinetic parameters was derived using an analysis of variance model. A total of 24 healthy Korean subjects participated, 23 of whom completed the study. The geometric mean ratio and its 90% confidence interval of once-daily ER itopride versus IR itopride three times a day for AUC(0-24h) were contained within the conventional bioequivalence range of 0.80-1.25 (0.94 [0.88-1.01]), although Cmax was reached more slowly and was lower for itopride ER than for the IR formulation. Food delayed the time taken to reach Cmax for itopride ER, but AUC(0-24h) was not affected. There were no serious adverse events and both formulations were generally well tolerated. At steady state, once-daily itopride ER at 150 mg has a bioavailability comparable with that of itopride IR at 50 mg given three times a day under fasting conditions. Food delayed the absorption of itopride ER, with no marked change in its oral bioavailability.

  3. Delayed release dexlansoprazole in the treatment of GERD and erosive esophagitis

    Directory of Open Access Journals (Sweden)

    Eric T Wittbrodt

    2009-11-01

    Full Text Available Eric T Wittbrodt1, Charles Baum2, David A Peura31Takeda Pharmaceuticals North America, Inc., 2Takeda Pharmaceuticals International, Inc., Deerfield, IL, USA; 3University of Virginia, School of Medicine, Charlottesville, VA, USAAbstract: Although proton pump inhibitors (PPI have a record of remarkable effectiveness and safety in the management of gastroesophageal reflux disease (GERD, several treatment challenges with PPI have emerged. Dexlansoprazole MR is the (R-enantiomer of lansoprazole contained in a formulation that produces two distinct releases of drug and significantly extends the duration of active plasma concentrations and % time pH > 4 beyond that of conventional singlerelease PPI. Dexlansoprazole MR can be administered without regard to meals or the timing of meals in most patients. Dexlansoprazole MR 60 mg demonstrated similar efficacy for healing of erosive esophagitis at 8 weeks compared with lansoprazole 30 mg, and dexlansoprazole MR 30 mg was superior to placebo for maintenance of healed erosive esophagitis at 6 months with 99% of nights and 96% of days heartburn-free over 6 months in patients taking dexlansoprazole MR 30 mg. Superior relief of heartburn occurred in patients taking dexlansoprazole MR 30 mg (55% heartburn-free 24-hour periods vs placebo (14% for symptomatic nonerosive GERD. The safety profile of dexlansoprazole MR is similar to that of lansoprazole. The extended pharmacodynamic effects, added convenience, and efficacy and safety of dexlansoprazole MR offer a novel approach to gastric pH control in patients with acid-related disorders.Keywords: dexlansoprazole MR, gastroesophageal reflux disease, GERD, erosive esophagitis, TAK-390MR

  4. VA office of inspector general releases scathing report of Phoenix VA

    Directory of Open Access Journals (Sweden)

    Robbins RA

    2014-08-01

    Full Text Available No abstract available. Article truncated at 150 words. The long-awaited Office of Inspector General’s (OIG report on the Phoenix VA Health Care System (PVAHCS was released on August 27, 2014 (1. The report was scathing in its evaluation of VA practices and leadership. Five questions were investigated: 1.Were there clinically significant delays in care? 2. Did PVAHCS omit the names of veterans waiting for care from its Electronic Wait List (EWL? 3. Were PVAHCS personnel not following established scheduling procedures? 4. Did the PVAHCS culture emphasize goals at the expense of patient care? 5. Are scheduling deficiencies systemic throughout the VA? In each case, the OIG found that the allegations were true. Despite initial denials, the OIG report showed that former PVAHCS director Sharon Helman, associate director Lance Robinson, hospital administration director Brad Curry, chief of staff Darren Deering and other senior executives were aware of delays in care and unofficial wait lists. Perhaps most disturbing is ...

  5. Distinct presynaptic control of dopamine release in striosomal and matrix areas of the cat caudate nucleus

    International Nuclear Information System (INIS)

    Kemel, M.L.; Desban, M.; Glowinski, J.; Gauchy, C.

    1989-01-01

    By use of a sensitive in vitro microsuperfusion method, the cholinergic presynaptic control of dopamine release was investigated in a prominent striosome (areas poor in acetylcholinesterase activity) located within the core of cat caudate nucleus and also in adjacent matrix area. The spontaneous release of [ 3 H]dopamine continuously synthesized from [ 3 H]tyrosine in the matrix area was found to be twice that in the striosomal area; the spontaneous and potassium-evoked releases of [ 3 H]dopamine were calcium-dependent in both compartments. With 10 -6 M tetrodotoxin, 5 x 10 -5 M acetylcholine stimulated [ 3 H]dopamine release in both striosomal and matrix areas, effects completely antagonized by atropine, thus showing the involvement of muscarinic receptors located on dopaminergic nerve terminals. Experiments without tetrodotoxin revealed a more complex regulation of dopamine release in the matrix: (i) in contrast to results seen in the striosome, acetylcholine induced only a transient stimulatory effect on matrix dopamine release. (ii) Although 10 -6 M atropine completely abolished the cholinergic stimulatory effect on [ 3 H]dopamine release in striosomal area, delayed and prolonged stimulation of [ 3 H] dopamine release was seen with atropine in the matrix. The latter effect was completely abolished by the nicotinic antagonist pempidine. Therefore, in the matrix, in addition to its direct (tetrodotoxin-insensitive) facilitatory action on [ 3 H]dopamine release, acetylcholine exerts two indirect (tetrodotoxin-sensitive) opposing effects: an inhibition and a stimulation of [ 3 H]dopamine release mediated by muscarinic and nicotinic receptors, respectively

  6. Delayed enhanced MRI in intraparenchymal tumors

    International Nuclear Information System (INIS)

    Eguchi, Takahiko; Morimoto, Tetsuya; Takeshima, Toshikazu

    1991-01-01

    Delayed enhanced MRI was performed on 20 intraparenchymal tumors, and these findings were compared with those of early enhanced MRI. Using the spin-echo technique (SE: 400-500/20 msec), early scans were obtained 5 minutes, and delayed scans were obtained 60 minutes, after the intravenous injection of 0.1 nmol of gadolinium-DTPA/Kg. We discussed the changes in the delayed scan with regard to the change in the pattern of enhancement and the boundary of enhancement. In these twenty intraparenchymal tumors, there were three low-grade astrocytomas, two anaplastic astrocytomas, seven glioblastomas, and eight metastatic tumors. The changes in the enhanced pattern showed three types as follows: Type I: heterogeneous enhancement in both early and delayed scans; Type II: heterogeneous enhancement in early scan and homogeneous enhancement in delayed scan; Type III: homogeneous enhancement in both early and delayed scans. Most malignant tumors, such as glioblastomas (6/8), anaplastic astrocytomas (2/2), and metastatic tumors (7/8), revealed Type I, although low-grade astrocytomas showed Type II (3/2) and Type III (1/3). The heterogeneous enhancement in delayed scan was found in malignant tumors and in low-grade astrocytoma; even if the early scan revealed heterogeneous enhancement, the delayed scan showed homogeneous enhancement. In the delayed scan, most enhanced boundaries spread out of the boundaries in the early scan. Glioblastomas spread markedly in the delayed scan, although none of the low-grade astrocytomas, anaplastic astrocytomas, or metastases revealed marked spreading. We called these marked increases in the delayed scan a 'spreading sign' and thought that this sign was specific to glioblastomas. Recently some authors have emphasized the usefulness of serial scans. Delayed enhanced MRI 60 minutes after the administration of a contrast medium was here found also to be useful for the accurate diagnosis for brain tumors. (author)

  7. Project delay analysis of HRSG

    Science.gov (United States)

    Silvianita; Novega, A. S.; Rosyid, D. M.; Suntoyo

    2017-08-01

    Completion of HRSG (Heat Recovery Steam Generator) fabrication project sometimes is not sufficient with the targeted time written on the contract. The delay on fabrication process can cause some disadvantages for fabricator, including forfeit payment, delay on HRSG construction process up until HRSG trials delay. In this paper, the author is using semi quantitative on HRSG pressure part fabrication delay with configuration plant 1 GT (Gas Turbine) + 1 HRSG + 1 STG (Steam Turbine Generator) using bow-tie analysis method. Bow-tie analysis method is a combination from FTA (Fault tree analysis) and ETA (Event tree analysis) to develop the risk matrix of HRSG. The result from FTA analysis is use as a threat for preventive measure. The result from ETA analysis is use as impact from fabrication delay.

  8. Nonlinear delay monopoly with bounded rationality

    International Nuclear Information System (INIS)

    Matsumoto, Akio; Szidarovszky, Ferenc

    2012-01-01

    The purpose of this paper is to study the dynamics of a monopolistic firm in a continuous-time framework. The firm is assumed to be boundedly rational and to experience time delays in obtaining and implementing information on output. The dynamic adjustment process is based on the gradient of the expected profit. The paper is divided into three parts: we examine delay effects on dynamics caused by one-time delay and two-time delays in the first two parts. Global dynamics and analytical results on local dynamics are numerically confirmed in the third part. Four main results are demonstrated. First, the stability switch from stability to instability occurs only once in the case of a single delay. Second, the alternation of stability and instability can continue if two time delays are involved. Third, the occurence of Hopf bifurcation is analytically shown if stability is lost. Finally, in a bifurcation process, there are a period-doubling cascade to chaos and a period-halving cascade to the equilibrium point in the case of two time delays if the difference between the two delays is large.

  9. Memorized discrete systems and time-delay

    CERN Document Server

    Luo, Albert C J

    2017-01-01

    This book examines discrete dynamical systems with memory—nonlinear systems that exist extensively in biological organisms and financial and economic organizations, and time-delay systems that can be discretized into the memorized, discrete dynamical systems. It book further discusses stability and bifurcations of time-delay dynamical systems that can be investigated through memorized dynamical systems as well as bifurcations of memorized nonlinear dynamical systems, discretization methods of time-delay systems, and periodic motions to chaos in nonlinear time-delay systems. The book helps readers find analytical solutions of MDS, change traditional perturbation analysis in time-delay systems, detect motion complexity and singularity in MDS; and determine stability, bifurcation, and chaos in any time-delay system.

  10. Vernier Delay Unit

    International Nuclear Information System (INIS)

    Pierce, W.B.

    1984-10-01

    This module will accept differential ECL pulses from the auxiliary rear panel or NIM level pulses from the front panel. The pulses are produced at the output with a fixed delay that is software programmable in steps of 0.1 ns over the range of 0.1 to 10.5 ns. Multiple outputs are available at the front panel. Minimum delay through the module is 9 ns

  11. Investigation of activity release from bituminized intermediate-level waste forms under thermal stresses

    International Nuclear Information System (INIS)

    Kluger, W.; Vejmelka, P.; Koester, R.

    1983-01-01

    To determine the consequences of a fire during fabrication, intermediate storage and transport of bituminized NaNO 3 waste forms, the fractions of plutonium released from the waste forms were assessed. For this purpose, laboratory tests were made with PuO 2 -containing specimens as well as a field test with specimens containing Eu 2 O 3 . By the evaluation of plutonium release in the laboratory and by the determination of the total sodium release and the relative Eu/Na release in the field tests the plutonium release can be deduced from full-scale specimens. The results show that for bituminized waste forms with high NaNO 3 contents (approx. 36 wt%) the average plutonium release obtained in laboratory testing is 15%. In the field tests (IAEA fire test conditions) an average Eu release of 8% was found. These results justify the statement that also for waste forms in open 175 L drum inserts a maximum plutonium release of about 15% can be expected. From the time-dependence of Eu/Na release in the field tests an induction period of 15-20 minutes between the start of testing and the first Na/Eu release can be derived. The maximum differential Na/Eu release occurs after a test period of 45 to 60 minutes duration and after 90 to 105 minutes (tests K2 and K4, respectively); after that time also the highest temperatures in the products are measured. The release values were determined for products in open 175 L drum inserts which in this form are not eligible for intermediate and ultimate storage. For bituminized waste forms in concrete packages (lost concrete shieldings) a delayed increase in temperature to only 70-80 deg. C takes place (4-5 hours after extinction of the fire) if the fire lasts 45 minutes. The concrete package remains intact under test conditions. This means that activity release from bituminized waste forms packaged in this way can be ruled out in the case under consideration. (author)

  12. Dryout delay in loss-of-coolant incidents in nuclear power plants

    International Nuclear Information System (INIS)

    Belda, W.

    1975-01-01

    The maximum credible accident (MCA) as a result of a fault in the system is assumed to be the rupture of a pipe in the primary circuit. During the outflow process following the rupture - called blowdown - it is possible that the internals of a reactor pressure vessel are exposed to extreme mechanical and thermal stresses. The fuel rods in the core, the Zircaloy cladding tubes of which can be heated up by lack of coolant to inadmissibly high temperatures, are particularly at risk. In case of the cladding tubes being damaged, radioactive substances are released. If they escape from the outer containment, this would lead to pressures on the immediate and more distant vicinity of the nuclear pover plant. In order to eliminate the factors of uncertainty when calculating the overall blowdown process in advance, it is necessary to have a relationship valid for the instationary circumstances to work out the burnout delay which is of decisive importance for the post-incident cooling phase of the reactor. The aim of this investigation, therefore, is to develop, with the aid of a suitable model, a method of calculating the burnout delay. (orig./TK) [de

  13. Exponential synchronization of two nonlinearly non-delayed and delayed coupled complex dynamical networks

    International Nuclear Information System (INIS)

    Zheng Song

    2012-01-01

    In this paper, the exponential synchronization between two nonlinearly coupled complex networks with non-delayed and delayed coupling is investigated with Lyapunov-Krasovskii-type functionals. Based on the stability analysis of the impulsive differential equation and the linear matrix inequality, sufficient delay-dependent conditions for exponential synchronization are derived, and a linear impulsive controller and simple updated laws are also designed. Furthermore, the coupling matrices need not be symmetric or irreducible. Numerical examples are presented to verify the effectiveness and correctness of the synchronization criteria obtained.

  14. Controlled Release from Core-Shell Nano porous Silica Particles for Corrosion Inhibition of Aluminum Alloys

    International Nuclear Information System (INIS)

    Jiang, X.; Rathod, Sh.; Shah, P.; Brinker, C.J.; Jiang, X.; Jiang, Y.; Liu, N.; Xu, H.; Brinker, C.J.

    2011-01-01

    Cerium (Ce) corrosion inhibitors were encapsulated into hexagonally ordered nanoporous silica particles via single-step aerosol-assisted self-assembly. The core/shell structured particles are effective for corrosion inhibition of aluminum alloy AA2024-T3. Numerical simulation proved that the core-shell nanostructure delays the release process. The effective diffusion coefficient elucidated from release data for monodisperse particles in water was 1.0x10-14 m 2 s for Ce 3+ compared to 2.5x10-13 m 2 s for NaCl. The pore size, pore surface chemistry, and the inhibitor solubility are crucial factors for the application. Microporous hydrophobic particles encapsulating a less soluble corrosion inhibitor are desirable for long-term corrosion inhibition.

  15. Crushed tablets: does the administration of food vehicles and thickened fluids to aid medication swallowing alter drug release?

    Science.gov (United States)

    Manrique, Yady J; Lee, Danielle J; Islam, Faiza; Nissen, Lisa M; Cichero, Julie A Y; Stokes, Jason R; Steadman, Kathryn J

    2014-01-01

    To evaluate the influence of co-administered vehicles on in vitro dissolution in simulated gastric fluid of crushed immediate release tablets as an indicator for potential drug bioavailability compromise. Release and dissolution of crushed amlodipine, atenolol, carbamazepine and warfarin tablets were tested with six foods and drinks that are frequently used in the clinical setting as mixers for crushed medications (water, orange juice, honey, yoghurt, strawberry jam and water thickened with Easythick powder) in comparison to whole tablets. Five commercial thickening agents (Easythick Advanced, Janbak F, Karicare, Nutilis, Viscaid) at three thickness levels were tested for their effect on the dissolution of crushed atenolol tablets. Atenolol dissolution was unaffected by mixing crushed tablets with thin fluids or food mixers in comparison to whole tablets or crushed tablets in water, but amlodipine was delayed by mixing with jam. Mixing crushed warfarin and carbamazepine tablets with honey, jam or yoghurt caused them to resemble the slow dissolution of whole tablets rather than the faster dissolution of crushed tablets in water or orange juice. Crushing and mixing any of the four medications with thickened water caused a significant delay in dissolution. When tested with atenolol, all types of thickening agents at the greatest thickness significantly restricted dissolution, and products that are primarily based on xanthan gum also delayed dissolution at the intermediate thickness level. Dissolution testing, while simplistic, is a widely used and accepted method for comparing drug release from different formulations as an indicator for in vivo bioavailability. Thickened fluids have the potential to retard drug dissolution when used at the thickest levels. These findings highlight potential clinical implications of the addition of these agents to medications for the purpose of dose delivery and indicate that further investigation of thickened fluids and their

  16. Enteric-coated sustained-release nanoparticles by coaxial electrospray: preparation, characterization, and in vitro evaluation

    Science.gov (United States)

    Hao, Shilei; Wang, Bochu; Wang, Yazhou; Xu, Yingqian

    2014-02-01

    Enteric-coated formulations can delay the release of drugs until they have passed through the stomach. However, high concentration of drugs caused by rapidly released in the small intestine leads to the intestinal damage, and frequent administration would increase the probability of missing medication and reduce the patient compliance. To solve the above-mentioned problems, aspirin-loaded enteric-coated sustained-release nanoparticles with core-shell structure were prepared via one-step method using coaxial electrospray in this study. Eudragit L100-55 as pH-sensitive polymer and Eudragit RS as sustained-release polymer were used for the outer coating and inner core of the nanoparticles, respectively. The maximum loading capacity of nanoparticles was 23.66 % by changing the flow rate ratio of outer/inner solutions, and the entrapment efficiency was nearly 100 %. Nanoparticles with core-shell structure were observed via fluorescence microscope and transmission electron microscope. And pH-sensitive and sustained drug release profiles were observed in the media with different pH values (1.2 and 6.8). In addition, mild cytotoxicity in vitro was detected, and the nanoparticles could be taken up by Caco-2 cells within 1.0 h in cellular uptake study. These results indicate that prepared enteric-coated sustained-release nanoparticles would be a more safety and effective carrier for oral drug delivery.

  17. Delay-Range-Dependent H∞ Control for Automatic Mooring Positioning System with Time-Varying Input Delay

    Directory of Open Access Journals (Sweden)

    Xiaoyu Su

    2014-01-01

    Full Text Available Aiming at the economy and security of the positioning system in semi-submersible platform, the paper presents a new scheme based on the mooring line switching strategy. Considering the input delay in switching process, H∞ control with time-varying input delay is designed to calculate the control forces to resist disturbing forces. In order to reduce the conservativeness, the information of the lower bound of delay is taken into account, and a Lyapunov function which contains the range of delay is constructed. Besides, the input constraint is considered to avoid breakage of mooring lines. The sufficient conditions for delay-range-dependent stabilization are derived in terms of LMI, and the controller is also obtained. The effectiveness of the proposed approach is illustrated by a realistic design example.

  18. Systematic of delayed neutron parameters

    International Nuclear Information System (INIS)

    Isaev, S.G.; Piksaikin, V.M.

    2000-01-01

    The experimental studies of the energy dependence of the delayed neutron (DN) parameters for various fission systems has shown that the behaviour of a some combination of delayed neutron parameters has a similar features. On the basis of this findings the systematics of delayed neutron experimental data for thorium, uranium, plutonium and americium isotopes have been investigated with the purpose to find a correlation of DN parameters with characteristics of fissioning system as well as a correlation between the delayed neutron parameters themselves. It was presented the preliminary results which were obtained during study the physics interpretation of the results [ru

  19. Radiation shielding provided by residential houses in Japan in reactor accidents accompanied with atmospheric release

    International Nuclear Information System (INIS)

    Yamaguchi, Yasuhiro; Minami, Kentaro

    1991-01-01

    The present report describes the radiation shielding effect of houses in Japan against the radioactive cloud resulting from a major reactor accident accompanied with atmospheric release. The shielding factor of houses, the ratio of indoor exposure rate to outdoor one, has been studied for the semi-infinite and finite clouds which contain γ-emitting radionuclides released from a reactor facility. The shielding factor of houses against γ-rays from the radioactive cloud decreases gradually with release delay time and keeps a minimum during the period from 50 to 1000 hours after reactor shutdown while 133 Xe predominates in the cloud. Radioiodines mixed in the cloud raise slightly the shielding factor, and the factor depends little on the shape of the cloud. A set of shielding factors for the use of emergency planning was consequently proposed as 0.4 for simple ferroconcrete residential house and 0.9 for other ordinary ones. (author)

  20. Engineering Sensorial Delay to Control Phototaxis and Emergent Collective Behaviors

    Directory of Open Access Journals (Sweden)

    Mite Mijalkov

    2016-01-01

    Full Text Available Collective motions emerging from the interaction of autonomous mobile individuals play a key role in many phenomena, from the growth of bacterial colonies to the coordination of robotic swarms. For these collective behaviors to take hold, the individuals must be able to emit, sense, and react to signals. When dealing with simple organisms and robots, these signals are necessarily very elementary; e.g., a cell might signal its presence by releasing chemicals and a robot by shining light. An additional challenge arises because the motion of the individuals is often noisy; e.g., the orientation of cells can be altered by Brownian motion and that of robots by an uneven terrain. Therefore, the emphasis is on achieving complex and tunable behaviors from simple autonomous agents communicating with each other in robust ways. Here, we show that the delay between sensing and reacting to a signal can determine the individual and collective long-term behavior of autonomous agents whose motion is intrinsically noisy. We experimentally demonstrate that the collective behavior of a group of phototactic robots capable of emitting a radially decaying light field can be tuned from segregation to aggregation and clustering by controlling the delay with which they change their propulsion speed in response to the light intensity they measure. We track this transition to the underlying dynamics of this system, in particular, to the ratio between the robots’ sensorial delay time and the characteristic time of the robots’ random reorientation. Supported by numerics, we discuss how the same mechanism can be applied to control active agents, e.g., airborne drones, moving in a three-dimensional space. Given the simplicity of this mechanism, the engineering of sensorial delay provides a potentially powerful tool to engineer and dynamically tune the behavior of large ensembles of autonomous mobile agents; furthermore, this mechanism might already be at work within

  1. Controlled Release from Core-Shell Nanoporous Silica Particles for Corrosion Inhibition of Aluminum Alloys

    Directory of Open Access Journals (Sweden)

    Xingmao Jiang

    2011-01-01

    Full Text Available Cerium (Ce corrosion inhibitors were encapsulated into hexagonally ordered nanoporous silica particles via single-step aerosol-assisted self-assembly. The core/shell structured particles are effective for corrosion inhibition of aluminum alloy AA2024-T3. Numerical simulation proved that the core-shell nanostructure delays the release process. The effective diffusion coefficient elucidated from release data for monodisperse particles in water was 1.0×10−14 m2s for Ce3+ compared to 2.5×10−13 m2s for NaCl. The pore size, pore surface chemistry, and the inhibitor solubility are crucial factors for the application. Microporous hydrophobic particles encapsulating a less soluble corrosion inhibitor are desirable for long-term corrosion inhibition.

  2. Delay-Dependent Guaranteed Cost H∞ Control of an Interval System with Interval Time-Varying Delay

    Directory of Open Access Journals (Sweden)

    Zhongke Shi

    2009-01-01

    Full Text Available This paper concerns the problem of the delay-dependent robust stability and guaranteed cost H∞ control for an interval system with time-varying delay. The interval system with matrix factorization is provided and leads to less conservative conclusions than solving a square root. The time-varying delay is assumed to belong to an interval and the derivative of the interval time-varying delay is not a restriction, which allows a fast time-varying delay; also its applicability is broad. Based on the Lyapunov-Ktasovskii approach, a delay-dependent criterion for the existence of a state feedback controller, which guarantees the closed-loop system stability, the upper bound of cost function, and disturbance attenuation lever for all admissible uncertainties as well as out perturbation, is proposed in terms of linear matrix inequalities (LMIs. The criterion is derived by free weighting matrices that can reduce the conservatism. The effectiveness has been verified in a number example and the compute results are presented to validate the proposed design method.

  3. Stochastic two-delay differential model of delayed visual feedback effects on postural dynamics.

    Science.gov (United States)

    Boulet, Jason; Balasubramaniam, Ramesh; Daffertshofer, Andreas; Longtin, André

    2010-01-28

    We report on experiments and modelling involving the 'visuo-postural control loop' in the upright stance. We experimentally manipulated an artificial delay to the visual feedback during standing, presented at delays ranging from 0 to 1 s in increments of 250 ms. Using stochastic delay differential equations, we explicitly modelled the centre-of-pressure (COP) and centre-of-mass (COM) dynamics with two independent delay terms for vision and proprioception. A novel 'drifting fixed point' hypothesis was used to describe the fluctuations of the COM with the COP being modelled as a faster, corrective process of the COM. The model was in good agreement with the data in terms of probability density functions, power spectral densities, short- and long-term correlations (Hurst exponents) as well the critical time between the two ranges. This journal is © 2010 The Royal Society

  4. Halloysite Nanotubes: Controlled Access and Release by Smart Gates.

    Science.gov (United States)

    Cavallaro, Giuseppe; Danilushkina, Anna A; Evtugyn, Vladimir G; Lazzara, Giuseppe; Milioto, Stefana; Parisi, Filippo; Rozhina, Elvira V; Fakhrullin, Rawil F

    2017-07-28

    Hollow halloysite nanotubes have been used as nanocontainers for loading and for the triggered release of calcium hydroxide for paper preservation. A strategy for placing end-stoppers into the tubular nanocontainer is proposed and the sustained release from the cavity is reported. The incorporation of Ca(OH)₂ into the nanotube lumen, as demonstrated using transmission electron microscopy (TEM) imaging and Energy Dispersive X-ray (EDX) mapping, retards the carbonatation, delaying the reaction with CO₂ gas. This effect can be further controlled by placing the end-stoppers. The obtained material is tested for paper deacidification. We prove that adding halloysite filled with Ca(OH)₂ to paper can reduce the impact of acid exposure on both the mechanical performance and pH alteration. The end-stoppers have a double effect: they preserve the calcium hydroxide from carbonation, and they prevent from the formation of highly basic pH and trigger the response to acid exposure minimizing the pH drop-down. These features are promising for a composite nanoadditive in the smart protection of cellulose-based materials.

  5. A New Application of Lipid Nanoemulsions as Coating Agent, Providing Zero-Order Hydrophilic Drug Release from Tablets

    Directory of Open Access Journals (Sweden)

    Nicolas Anton

    2012-01-01

    Full Text Available The objective of the present investigation was to evaluate potential of nanoemulsions as a coating material for the tablets. The nanoemulsion of size less than 100 nm was prepared using a simple and low-energy spontaneous emulsification method. Conventional tablets containing theophylline as a model hydrophilic drug were prepared. The theophylline tablets were coated with the nanoemulsion using a fluid bed coater. The effect of different levels of the nanoemulsion coating on the theophylline release was evaluated. The theophylline tablets containing different levels of the nanoemulsion coating could be successfully prepared. Interestingly, the coating of tablet with the nanoemulsion resulted in zero-order release of theophylline from the tablets. The noncoated theophylline tablets release the entire drug in less than 2 minutes, whereas nanoemulsion coating delayed the release of theophylline from tablets. This investigation establishes the proof of concept for the potential of nanoemulsions as a coating material for tablets.

  6. Analysis of a first-order delay differential-delay equation containing two delays

    Science.gov (United States)

    Marriott, C.; Vallée, R.; Delisle, C.

    1989-09-01

    An experimental and numerical analysis of the behavior of a two-delay differential equation is presented. It is shown that much of the system's behavior can be related to the stability behavior of the underlying linearized modes. A new phenomenon, mode crossing, is explored.

  7. Delaying gratification depends on social trust

    Science.gov (United States)

    Michaelson, Laura; de la Vega, Alejandro; Chatham, Christopher H.; Munakata, Yuko

    2013-01-01

    Delaying gratification is hard, yet predictive of important life outcomes, such as academic achievement and physical health. Prominent theories focus on the role of self-control, hypersensitivity to immediate rewards, and the cost of time spent waiting. However, delaying gratification may also require trust in people delivering future rewards as promised. To test the role of social trust, participants were presented with character vignettes and faces that varied in trustworthiness, and then choose between hypothetical smaller immediate or larger delayed rewards from those characters. Across two experiments, participants were less willing to wait for delayed rewards from less trustworthy characters, and perceived trustworthiness predicted willingness to delay gratification. These findings provide the first demonstration of a causal role for social trust in willingness to delay gratification, independent of other relevant factors, such as self-control or reward history. Thus, delaying gratification requires choosing not only a later reward, but a reward that is potentially less likely to be delivered, when there is doubt about the person promising it. Implications of this work include the need to revise prominent theories of delay of gratification, and new directions for interventions with populations characterized by impulsivity. PMID:23801977

  8. Delaying gratification depends on social trust

    Directory of Open Access Journals (Sweden)

    Laura eMichaelson

    2013-06-01

    Full Text Available Delaying gratification is hard, yet predictive of important life outcomes, such as academic achievement and physical health. Prominent theories focus on the role of self-control, hypersensitivity to immediate rewards, and the cost of time spent waiting. However, delaying gratification may also require trust in people delivering future rewards as promised. To test the role of social trust, participants were presented with character vignettes and faces that varied in trustworthiness, and then chose between hypothetical smaller immediate or larger delayed rewards from those characters. Across two experiments, participants were less willing to wait for delayed rewards from less trustworthy characters, and perceived trustworthiness predicted willingness to delay gratification. These findings provide the first demonstration of a causal role for social trust in willingness to delay gratification, independent of other relevant factors, such as self-control or reward history. Thus, delaying gratification requires choosing not only a later reward, but a reward that is potentially less likely to be delivered, when there is doubt about the person promising it. Implications of this work include the need to revise prominent theories of delay of gratification, and new directions for interventions with populations characterized by impulsivity.

  9. Boarding is associated with higher rates of medication delays and adverse events but fewer laboratory-related delays.

    Science.gov (United States)

    Sri-On, Jiraporn; Chang, Yuchiao; Curley, David P; Camargo, Carlos A; Weissman, Joel S; Singer, Sara J; Liu, Shan W

    2014-09-01

    Hospital crowding and emergency department (ED) boarding are large and growing problems. To date, there has been a paucity of information regarding the quality of care received by patients boarding in the ED compared with the care received by patients on an inpatient unit. We compared the rate of delays and adverse events at the event level that occur while boarding in the ED vs while on an inpatient unit. This study was a secondary analysis of data from medical record review and administrative databases at 2 urban academic teaching hospitals from August 1, 2004, through January 31, 2005. We measured delayed repeat cardiac enzymes, delayed partial thromboplastin time level checks, delayed antibiotic administration, delayed administration of home medications, and adverse events. We compared the incidence of events during ED boarding vs while on an inpatient unit. Among 1431 patient medical records, we identified 1016 events. Emergency department boarding was associated with an increased risk of home medication delays (risk ratio [RR], 1.54; 95% confidence interval [CI], 1.26-1.88), delayed antibiotic administration (RR, 2.49; 95% CI, 1.72-3.52), and adverse events (RR, 2.36; 95% CI, 1.15-4.72). On the contrary, ED boarding was associated with fewer delays in repeat cardiac enzymes (RR, 0.17; 95% CI, 0.09-0.27) and delayed partial thromboplastin time checks (RR, 0.54; 95% CI, 0.27-0.96). Compared with inpatient units, ED boarding was associated with more medication-related delays and adverse events but fewer laboratory-related delays. Until we can eliminate ED boarding, it is critical to identify areas for improvement. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Global exponential convergence of neutral-type Hopfield neural networks with multi-proportional delays and leakage delays

    International Nuclear Information System (INIS)

    Xu, Changjin; Li, Peiluan

    2017-01-01

    This paper is concerned with a class of neutral-type Hopfield neural networks with multi-proportional delays and leakage delays. Using the differential inequality theory, a set of sufficient conditions which guarantee that all solutions of neutral-type Hopfield neural networks with multi-proportional delays and leakage delays converge exponentially to zero vector are derived. Computer simulations are carried out to verify our theoretical findings. The obtained results of this paper are new and complement some previous studies.

  11. Suppression of MMP activity in bovine cartilage explants cultures has little if any effect on the release of aggrecanase-derived aggrecan fragments

    Directory of Open Access Journals (Sweden)

    Sondergaard Bodil-Cecilie

    2009-12-01

    Full Text Available Abstract Background Progressive loss of articular cartilage is a central hallmark in many joint disease, however, the relative importance of individual proteolytic pathways leading to cartilage erosion is at present unknown. We therefore investigated the time-dependant release ex vivo of MMP- and aggrecanase-derived fragments of aggrecan and type II collagen into the supernatant of bovine cartilage explants cultures using neo-epitope specific immunoassays, and to associate the release of these fragments with the activity of proteolytic enzymes using inhibitors. Findings Bovine cartilage explants were cultured in the presence or absence of the catabolic cytokines oncostatin M (OSM and tumor necrosis factor alpha (TNFα. In parallel, explants were co-cultured with protease inhibitors such as GM6001, TIMP1, TIMP2 and TIMP3. Fragments released into the supernatant were determined using a range of neo-epitope specific immunoassays; (1 sandwich 342FFGVG-G2 ELISA, (2 competition NITEGE373ELISA (3 sandwich G1-NITEGE373 ELISA (4 competition 374ARGSV ELISA, and (5 sandwich 374ARGSV-G2 ELISA all detecting aggrecan fragments, and (6 sandwich CTX-II ELISA, detecting C-telopeptides of type II collagen. We found that (1 aggrecanase-derived aggrecan fragments are released in the early (day 2-7 and mid phase (day 9-14 into the supernatant from bovine explants cultures stimulated with catabolic cytokines, (2 the release of NITEGE373 neo-epitopes are delayed compared to the corresponding 374ARGSV fragments, (3 the MMP inhibitor GM6001 did not reduce the release of aggrecanase-derived fragment, but induced a further delay in the release of these fragments, and finally (4 the MMP-derived aggrecan and type II collagen fragments were released in the late phase (day 16-21 only. Conclusion Our data support the model, that aggrecanases and MMPs act independently in the processing of the aggrecan molecules, and furthermore that suppression of MMP-activity had little if

  12. Delay-Dependent Exponential Stability for Discrete-Time BAM Neural Networks with Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Yonggang Chen

    2008-01-01

    Full Text Available This paper considers the delay-dependent exponential stability for discrete-time BAM neural networks with time-varying delays. By constructing the new Lyapunov functional, the improved delay-dependent exponential stability criterion is derived in terms of linear matrix inequality (LMI. Moreover, in order to reduce the conservativeness, some slack matrices are introduced in this paper. Two numerical examples are presented to show the effectiveness and less conservativeness of the proposed method.

  13. Synchronization in networks with heterogeneous coupling delays

    Science.gov (United States)

    Otto, Andreas; Radons, Günter; Bachrathy, Dániel; Orosz, Gábor

    2018-01-01

    Synchronization in networks of identical oscillators with heterogeneous coupling delays is studied. A decomposition of the network dynamics is obtained by block diagonalizing a newly introduced adjacency lag operator which contains the topology of the network as well as the corresponding coupling delays. This generalizes the master stability function approach, which was developed for homogenous delays. As a result the network dynamics can be analyzed by delay differential equations with distributed delay, where different delay distributions emerge for different network modes. Frequency domain methods are used for the stability analysis of synchronized equilibria and synchronized periodic orbits. As an example, the synchronization behavior in a system of delay-coupled Hodgkin-Huxley neurons is investigated. It is shown that the parameter regions where synchronized periodic spiking is unstable expand when increasing the delay heterogeneity.

  14. Multi-purposable filaments of HPMC for 3D printing of medications with tailored drug release and timed-absorption.

    Science.gov (United States)

    Kadry, Hossam; Al-Hilal, Taslim A; Keshavarz, Ali; Alam, Farzana; Xu, Changxue; Joy, Abraham; Ahsan, Fakhrul

    2018-04-20

    Three-dimensional printing (3DP), though developed for nonmedical applications and once regarded as futuristic only, has recently been deployed for the fabrication of pharmaceutical products. However, the existing feeding materials (inks and filaments) that are used for printing drug products have various shortcomings, including the lack of biocompatibility, inadequate extrudability and printability, poor drug loading, and instability. Here, we have sought to develop a filament using a single pharmaceutical polymer, with no additives, which can be multi-purposed and manipulated by computational design for the preparation of tablets with desired release and absorption patterns. As such, we have used hydroxypropyl-methylcellulose (HPMC) and diltiazem, a model drug, to prepare both drug-free and drug-impregnated filaments, and investigated their thermal and crystalline properties, studied the cytotoxicity of the filaments, designed and printed tablets with various infill densities and patterns. By alternating the drug-free and drug-impregnated filaments, we fabricated various types of tablets, studied the drug release profiles, and assessed oral absorption in rats. Both diltiazem and HPMC were stable at extrusion and printing temperatures, and the drug loading was 10% (w/w). The infill density, as well as infill patterns, influenced the drug release profile, and thus, when the infill density was increased to 100%, the percentage of drug released dramatically declined. Tablets with alternating drug-free and drug-loaded layers showed delayed and intermittent drug release, depending on when the drug-loaded layers encountered the dissolution media. Importantly, the oral absorption patterns accurately reproduced the drug release profiles and showed immediate, extended, delayed and episodic absorption of the drug from the rat gastrointestinal tract (GIT). Overall, we have demonstrated here that filaments for 3D printers can be prepared from a pharmaceutical polymer with no

  15. Fission product release from defected nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Lewis, B.J.

    1983-01-01

    The release of gaseous (krypton and xenon) and iodine radioactive fission products from defective fuel elements is described with a semi-empirical model. The model assumes precursor-corrected 'Booth diffusional release' in the UO 2 and subsequent holdup in the fuel-to-sheath gap. Transport in the gap is separately modelled with a phenomenological rate constant (assuming release from the gap is a first order rate process), and a diffusivity constant (assuming transport in the gap is dominated by a diffusional process). Measured release data from possessing various states of defection are use in this analysis. One element (irradiated in an earlier experiment by MacDonald) was defected with a small drilled hole. A second element was machined with 23 slits while a third element (fabricated with a porous end plug) displayed through-wall sheath hydriding. Comparison of measured release data with calculated values from the model yields estimates of empirical diffusion coefficients for the radioactive species in the UO 2 (1.56 x 10 -10 to 7.30 x 10 -9 s -1 ), as well as escape rate constants (7.85 x 10 -7 to 3.44 x 10 -5 s -1 ) and diffusion coefficients (3.39 x 10 -5 to 4.88 x 10 -2 cm 2 /s) for these in the fuel-to-sheath gap. Analyses also enable identification of the various rate-controlling processes operative in each element. For the noble gas and iodine species, the rate-determining process in the multi-slit element is 'Booth diffusion'; however, for the hydrided element an additional delay results from diffusional transport in the fuel-to-heath gap. Furthermore, the iodine species exhibit an additional holdup in the drilled element because of significant trapping on the fuel and/or sheath surfaces. Using experimental release data and applying the theoretical results of this work, a systematic procedure is proposed to characterize fuel failures in commercial power reactors (i.e., the number of fuel failures and average leak size)

  16. Group Delay of High Q Antennas

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Pedersen, Gert Frølund

    2013-01-01

    Group Delay variations versus frequency is an essential factor which can cause distortion and degradation in the signals. Usually this is an issue in wideband communication systems, such as satellite communication systems, which are used for transmitting wideband data. However, group delay can also...... become an issue, when working with high Q antennas, because of the steep phase shift over the frequency. In this paper, it is measured how large group delay variations can become, when going from a low Q antenna to a high Q antenna. The group delay of a low Q antenna is shown to be around 1.3 ns, whereas...... a high Q antenna has group delay of around 22 ns. It is due to this huge group delay variation characteristics of high Q antennas, that signal distortion might occur in the radio system with high Q antennas....

  17. Linear rotary optical delay lines

    Science.gov (United States)

    Guerboukha, Hichem; Qu, Hang; Skorobogatiy, Maksim

    2016-03-01

    We present a semi-analytical solution for the design of a high-speed rotary optical delay line that use a combination of two rotating curvilinear reflectors. We demonstrate that it is possible to design an infinite variety of the optical delay lines featuring linear dependence of the optical delay on the rotation angle. This is achieved via shape optimization of the rotating reflector surfaces. Moreover, a convenient spatial separation of the incoming and outgoing beams is possible. For the sake of example, we present blades that fit into a circle of 10cm diameter. Finally, a prototype of a rotary delay line is fabricated using CNC machining, and its optical properties are characterized.

  18. Synchronization of nonidentical chaotic neural networks with leakage delay and mixed time-varying delays

    Directory of Open Access Journals (Sweden)

    Cao Jinde

    2011-01-01

    Full Text Available Abstract In this paper, an integral sliding mode control approach is presented to investigate synchronization of nonidentical chaotic neural networks with discrete and distributed time-varying delays as well as leakage delay. By considering a proper sliding surface and constructing Lyapunov-Krasovskii functional, as well as employing a combination of the free-weighting matrix method, Newton-Leibniz formulation and inequality technique, a sliding mode controller is designed to achieve the asymptotical synchronization of the addressed nonidentical neural networks. Moreover, a sliding mode control law is also synthesized to guarantee the reachability of the specified sliding surface. The provided conditions are expressed in terms of linear matrix inequalities, and are dependent on the discrete and distributed time delays as well as leakage delay. A simulation example is given to verify the theoretical results.

  19. Modelling for radiological and radioecological consequences of an accidental radionuclide release at Sea

    International Nuclear Information System (INIS)

    Paschoa, A.S.

    1997-01-01

    Full text: Scenarios concerning accidental releases of radionuclides into water bodies can be found in the open literature, mostly in connection with nuclear power plants located either onshore or inland. However, meager attention has been given to nuclear reactors used as energy sources for propulsion at sea, which are also subject to accidents. Such potential accidents may involve the loss of part of the reactor core to the surrounding water body. In addition of the initial instantaneous releases, one can estimate delayed source terms based on the rate at which radionuclides are dissolved or leached from the solidified material, like part of the core or structural materials in contact with water. Most of such solidified material might be a mixture of uranium, zirconium, iron, calcium, silica, fission and activation products, and transuranium elements as oxides, forming a glassy type solid. Transport models were used to calculate radionuclide concentrations in water resulting from short and delayed source terms. Oceanographic data used in the calculations were taken either from the open literature or from unclassified reports of the Brazilian Navy, being, however, as generic as possible. Time-dependent concentration functions for radionuclides in aquatic food following an accidental release reflect the net result of intake and elimination processes. However, to avoid the complexities of multiple parameters involved in such processes, the model accounts only for trophic transfer of radionuclides, and yet avoids the necessity of analyzing the details of each transfer step used to determine fish, crustacea, molluscs and seaweed accumulation. Swimming and other aquatic sports are not included in the model used for dose calculations because of theirs relatively low importance in comparison with the pathways concerning ingestion of aquatic food

  20. Synchronization of Markovian jumping stochastic complex networks with distributed time delays and probabilistic interval discrete time-varying delays

    International Nuclear Information System (INIS)

    Li Hongjie; Yue Dong

    2010-01-01

    The paper investigates the synchronization stability problem for a class of complex dynamical networks with Markovian jumping parameters and mixed time delays. The complex networks consist of m modes and the networks switch from one mode to another according to a Markovian chain with known transition probability. The mixed time delays are composed of discrete and distributed delays, the discrete time delay is assumed to be random and its probability distribution is known a priori. In terms of the probability distribution of the delays, the new type of system model with probability-distribution-dependent parameter matrices is proposed. Based on the stochastic analysis techniques and the properties of the Kronecker product, delay-dependent synchronization stability criteria in the mean square are derived in the form of linear matrix inequalities which can be readily solved by using the LMI toolbox in MATLAB, the solvability of derived conditions depends on not only the size of the delay, but also the probability of the delay-taking values in some intervals. Finally, a numerical example is given to illustrate the feasibility and effectiveness of the proposed method.

  1. Dynamics of Nonlinear Time-Delay Systems

    CERN Document Server

    Lakshmanan, Muthusamy

    2010-01-01

    Synchronization of chaotic systems, a patently nonlinear phenomenon, has emerged as a highly active interdisciplinary research topic at the interface of physics, biology, applied mathematics and engineering sciences. In this connection, time-delay systems described by delay differential equations have developed as particularly suitable tools for modeling specific dynamical systems. Indeed, time-delay is ubiquitous in many physical systems, for example due to finite switching speeds of amplifiers in electronic circuits, finite lengths of vehicles in traffic flows, finite signal propagation times in biological networks and circuits, and quite generally whenever memory effects are relevant. This monograph presents the basics of chaotic time-delay systems and their synchronization with an emphasis on the effects of time-delay feedback which give rise to new collective dynamics. Special attention is devoted to scalar chaotic/hyperchaotic time-delay systems, and some higher order models, occurring in different bran...

  2. Identification and systematical studies of the electron-capture delayed fission (ECDF) in the lead region

    CERN Multimedia

    Pauwels, D B; Lane, J

    2008-01-01

    In our recent experiment (March 2007) at the velocity filter SHIP(GSI) we observed the electron-capture delayed fission of the odd-odd isotope $^{194}$At. This is the first unambiguous identification of this phenomenon in the very neutron-deficient nuclei in the vicinity of the proton shell closure at Z=82. In addition, the total kinetic energy (TKE) for the daughter nuclide $^{194}$Po was measured, despite the fact that this isotope does not decay via spontaneous fission. Semi-empirical analysis of the electron-capture Q$_{EC}$ values and fission barriers B$_{f}$ shows that a relatively broad island of ECDF must exist in this region of the Nuclide Chart, with some of the nuclei having unusually high ECDF probabilities. Therefore, this Proposal is intended to initiate the systematic identification and study of $\\beta$-delayed fission at ISOLDE in the very neutron-deficient lead region. Our aim is to provide unique low-energy fission data (e.g. probabilities, TKE release, fission barriers and their isospin dep...

  3. Controllability of nonlinear delay oscillating systems

    Directory of Open Access Journals (Sweden)

    Chengbin Liang

    2017-05-01

    Full Text Available In this paper, we study the controllability of a system governed by second order delay differential equations. We introduce a delay Gramian matrix involving the delayed matrix sine, which is used to establish sufficient and necessary conditions of controllability for the linear problem. In addition, we also construct a specific control function for controllability. For the nonlinear problem, we construct a control function and transfer the controllability problem to a fixed point problem for a suitable operator. We give a sufficient condition to guarantee the nonlinear delay system is controllable. Two examples are given to illustrate our theoretical results by calculating a specific control function and inverse of a delay Gramian matrix.

  4. Modified-release hydrocortisone to provide circadian cortisol profiles.

    Science.gov (United States)

    Debono, Miguel; Ghobadi, Cyrus; Rostami-Hodjegan, Amin; Huatan, Hiep; Campbell, Michael J; Newell-Price, John; Darzy, Ken; Merke, Deborah P; Arlt, Wiebke; Ross, Richard J

    2009-05-01

    Cortisol has a distinct circadian rhythm regulated by the brain's central pacemaker. Loss of this rhythm is associated with metabolic abnormalities, fatigue, and poor quality of life. Conventional glucocorticoid replacement cannot replicate this rhythm. Our objectives were to define key variables of physiological cortisol rhythm, and by pharmacokinetic modeling test whether modified-release hydrocortisone (MR-HC) can provide circadian cortisol profiles. The study was performed at a Clinical Research Facility. Using data from a cross-sectional study in healthy reference subjects (n = 33), we defined parameters for the cortisol rhythm. We then tested MR-HC against immediate-release hydrocortisone in healthy volunteers (n = 28) in an open-label, randomized, single-dose, cross-over study. We compared profiles with physiological cortisol levels, and modeled an optimal treatment regimen. The key variables in the physiological cortisol profile included: peak 15.5 microg/dl (95% reference range 11.7-20.6), acrophase 0832 h (95% confidence interval 0759-0905), nadir less than 2 microg/dl (95% reference range 1.5-2.5), time of nadir 0018 h (95% confidence interval 2339-0058), and quiescent phase (below the mesor) 1943-0531 h. MR-HC 15 mg demonstrated delayed and sustained release with a mean (sem) maximum observed concentration of 16.6 (1.4) microg/dl at 7.41 (0.57) h after drug. Bioavailability of MR-HC 5, 10, and 15 mg was 100, 79, and 86% that of immediate-release hydrocortisone. Modeling suggested that MR-HC 15-20 mg at 2300 h and 10 mg at 0700 h could reproduce physiological cortisol levels. By defining circadian rhythms and using modern formulation technology, it is possible to allow a more physiological circadian replacement of cortisol.

  5. Drug-releasing nano-engineered titanium implants: therapeutic efficacy in 3D cell culture model, controlled release and stability

    Energy Technology Data Exchange (ETDEWEB)

    Gulati, Karan [School of Chemical Engineering, The University of Adelaide, SA 5005 (Australia); Kogawa, Masakazu; Prideaux, Matthew; Findlay, David M. [Discipline of Orthopaedics and Trauma, The University of Adelaide, SA 5005 (Australia); Atkins, Gerald J., E-mail: gerald.atkins@adelaide.edu.au [Discipline of Orthopaedics and Trauma, The University of Adelaide, SA 5005 (Australia); Losic, Dusan, E-mail: dusan.losic@adelaide.edu.au [School of Chemical Engineering, The University of Adelaide, SA 5005 (Australia)

    2016-12-01

    micrograms. • Controlled/delayed drug release patterns using simple biopolymer coatings. • TNTs survives the placement and retrieval from trabecular bone cores ex-vivo.

  6. Delayed rule following

    OpenAIRE

    Schmitt, David R.

    2001-01-01

    Although the elements of a fully stated rule (discriminative stimulus [SD], some behavior, and a consequence) can occur nearly contemporaneously with the statement of the rule, there is often a delay between the rule statement and the SD. The effects of this delay on rule following have not been studied in behavior analysis, but they have been investigated in rule-like settings in the areas of prospective memory (remembering to do something in the future) and goal pursuit. Discriminative even...

  7. Probing the limits of delay intolerance: preliminary young adult data from the Delay Frustration Task (DeFT).

    Science.gov (United States)

    Bitsakou, Paraskevi; Antrop, Inge; Wiersema, Jan Roelf; Sonuga-Barke, Edmund J S

    2006-02-15

    Delay intolerance/aversion is one amongst a number of candidate neuropsychological endophenotypes for ADHD. Pilot data suggest that, because of potential ceiling effects, simple choice measures of delay tolerance used for children are probably not appropriate for adolescents and adults. The Delay Frustration Task (DeFT) is a new measure of delay intolerance, designed to be used in a similar form with adolescents and adults as well as children. In it delay frustration is indexed as the number and duration of responses made on a response key during a series of unpredictable and unsignalled delay periods, which interrupt the completion of a simple computer-based tests. The aim of this study was to provide preliminary data on the applicability of the task in a sample of young adults. The DeFT was administered to 49 male and female undergraduate students selected from a normal population-base. Their mean age was 23.14 (S.D.=1.54). Three measures of delay frustration were recorded across time intervals during the response window; the number of responses, their duration and their combined product (total time button was pressed) was calculated for each second interval bin during the post-response delay period. The AARS and HADS were used as screening questionnaires for ADHD and anxiety behaviour, respectively. The results indicated that young adults with high-ADHD symptoms scores pressed the button more than those with low ADHD scores during the post-response delay condition. While both groups increased responding across time within intervals this was significantly more marked in the high-ADHD symptom group. These effects became more pronounced when anxiety was controlled. Young adults with high-ADHD symptoms appear to be more sensitive to the imposition of unscheduled and unsignalled delay during a simple maths test. DeFT may provide a useful index of delay tolerance in young adults with ADHD. Future research needs to examine DeFT performance in different age groups and

  8. Adaptive modification of the delayed feedback control algorithm with a continuously varying time delay

    International Nuclear Information System (INIS)

    Pyragas, V.; Pyragas, K.

    2011-01-01

    We propose a simple adaptive delayed feedback control algorithm for stabilization of unstable periodic orbits with unknown periods. The state dependent time delay is varied continuously towards the period of controlled orbit according to a gradient-descent method realized through three simple ordinary differential equations. We demonstrate the efficiency of the algorithm with the Roessler and Mackey-Glass chaotic systems. The stability of the controlled orbits is proven by computation of the Lyapunov exponents of linearized equations. -- Highlights: → A simple adaptive modification of the delayed feedback control algorithm is proposed. → It enables the control of unstable periodic orbits with unknown periods. → The delay time is varied continuously according to a gradient descend method. → The algorithm is embodied by three simple ordinary differential equations. → The validity of the algorithm is proven by computation of the Lyapunov exponents.

  9. Temperature Dependent Wire Delay Estimation in Floorplanning

    DEFF Research Database (Denmark)

    Winther, Andreas Thor; Liu, Wei; Nannarelli, Alberto

    2011-01-01

    Due to large variations in temperature in VLSI circuits and the linear relationship between metal resistance and temperature, the delay through wires of the same length can be different. Traditional thermal aware floorplanning algorithms use wirelength to estimate delay and routability. In this w......Due to large variations in temperature in VLSI circuits and the linear relationship between metal resistance and temperature, the delay through wires of the same length can be different. Traditional thermal aware floorplanning algorithms use wirelength to estimate delay and routability....... In this work, we show that using wirelength as the evaluation metric does not always produce a floorplan with the shortest delay. We propose a temperature dependent wire delay estimation method for thermal aware floorplanning algorithms, which takes into account the thermal effect on wire delay. The experiment...

  10. Permutation entropy with vector embedding delays

    Science.gov (United States)

    Little, Douglas J.; Kane, Deb M.

    2017-12-01

    Permutation entropy (PE) is a statistic used widely for the detection of structure within a time series. Embedding delay times at which the PE is reduced are characteristic timescales for which such structure exists. Here, a generalized scheme is investigated where embedding delays are represented by vectors rather than scalars, permitting PE to be calculated over a (D -1 ) -dimensional space, where D is the embedding dimension. This scheme is applied to numerically generated noise, sine wave and logistic map series, and experimental data sets taken from a vertical-cavity surface emitting laser exhibiting temporally localized pulse structures within the round-trip time of the laser cavity. Results are visualized as PE maps as a function of embedding delay, with low PE values indicating combinations of embedding delays where correlation structure is present. It is demonstrated that vector embedding delays enable identification of structure that is ambiguous or masked, when the embedding delay is constrained to scalar form.

  11. CGI delay compensation. [Computer Generated Image

    Science.gov (United States)

    Mcfarland, R. E.

    1986-01-01

    Computer-generated graphics in real-time helicopter simulation produces objectionable scene-presentation time delays. In the flight simulation laboratory at Ames Research Center, it has been determined that these delays have an adverse influence on pilot performance during agressive tasks such as nap of the earth (NOE) maneuvers. Using contemporary equipment, computer generated image (CGI) time delays are an unavoidable consequence of the operations required for scene generation. However, providing that magnitude distortions at higher frequencies are tolerable, delay compensation is possible over a restricted frequency range. This range, assumed to have an upper limit of perhaps 10 or 15 rad/sec, conforms approximately to the bandwidth associated with helicopter handling qualities research. A compensation algorithm is introduced here and evaluated in terms of tradeoffs in frequency responses. The algorithm has a discrete basis and accommodates both a large, constant transport delay interval and a periodic delay interval, as associated with asynchronous operations.

  12. Slow-release granisetron (APF530) versus palonosetron for chemotherapy-induced nausea/vomiting: analysis by American Society of Clinical Oncology emetogenicity criteria.

    Science.gov (United States)

    Raftopoulos, Harry; Boccia, Ralph; Cooper, William; O'Boyle, Erin; Gralla, Richard J

    2015-09-01

    APF530 is a novel sustained-release formulation of granisetron. In a Phase III trial, APF530 500 mg was noninferior to palonosetron 0.25 mg in preventing acute chemotherapy-induced nausea and vomiting (CINV) after moderately (MEC) or highly emetogenic chemotherapy (HEC) and delayed CINV after MEC, but not superior in preventing delayed CINV after HEC. Emetogenicity was classified by Hesketh criteria; this reanalysis uses newer American Society of Clinical Oncology criteria. Complete responses (no emesis or rescue medication) after cycle one were reanalyzed after reclassification of MEC and HEC by American Society of Clinical Oncology criteria. APF530 maintained noninferiority to palonosetron. Single-dose APF530 is a promising alternative to palonosetron for preventing acute and delayed CINV after MEC or HEC. The Clinicaltrials.gov identifier for this study is NCT00343460.

  13. New delay-dependent absolute stability criteria for Lur'e systems with time-varying delay

    Science.gov (United States)

    Chen, Yonggang; Bi, Weiping; Li, Wenlin

    2011-07-01

    In this article, the absolute stability problem is investigated for Lur'e systems with time-varying delay and sector-bounded nonlinearity. By employing the delay fractioning idea, the new augmented Lyapunov functional is first constructed. Then, by introducing some slack matrices and by reserving the useful term when estimating the upper bound of the derivative of Lyapunov functional, the new delay-dependent absolute stability criteria are derived in terms of linear matrix inequalities. Several numerical examples are presented to show the effectiveness and the less conservativeness of the proposed method.

  14. Carbon monoxide-induced delayed amnesia, delayed neuronal death and change in acetylcholine concentration in mice

    International Nuclear Information System (INIS)

    Nabeshima, T.; Katoh, A.; Ishimaru, H.; Yoneda, Y.; Ogita, K.; Murase, K.; Ohtsuka, H.; Inari, K.; Fukuta, T.; Kameyama, T.

    1991-01-01

    We investigated the interrelationship of delayed amnesia, delayed neuronal death and changes in acetylcholine concentration induced by carbon monoxide (CO)-exposure in mice. In the test for retention of the passive avoidance task, amnesia was observed 5 and 7 days after CO-exposure when the mice were exposed to CO 1 day after training; in the case when the mice were exposed to CO 5 and 7 days before training, amnesia was also observed in a retention test given 1 day after training. The number of pyramidal cells in the hippocampal CA1 subfield was lower than that of the control 3, 5 and 7 days after CO-exposure. But the neurodegeneration in the parietal cortex, area 1, was not observed until 7 days after CO-exposure. The findings indicated that the amnesia and the neuronal death were produced after a delay when the mice were exposed to CO. In addition, the delayed amnesia was closely related to the delayed neuronal death in the hippocampal CA1 subfield. Moreover, [3H]glutamate and [3H]glycine binding sites did not change after CO-exposure but, 7 days after CO-exposure, the concentration of acetylcholine and the binding of [3H]quinuclidinyl benzilate in the frontal cortex and the striatum were found to have significantly changed, but those in the hippocampus did not show significant change. Therefore, we suggest that delayed amnesia induced by CO-exposure may result from delayed neuronal death in the hippocampal CA1 subfield and dysfunction in the acetylcholinergic neurons, in the frontal cortex, the striatum and/or the hippocampus

  15. Carbon monoxide-induced delayed amnesia, delayed neuronal death and change in acetylcholine concentration in mice

    Energy Technology Data Exchange (ETDEWEB)

    Nabeshima, T.; Katoh, A.; Ishimaru, H.; Yoneda, Y.; Ogita, K.; Murase, K.; Ohtsuka, H.; Inari, K.; Fukuta, T.; Kameyama, T. (Meijo Univ., Nagoya (Japan))

    1991-01-01

    We investigated the interrelationship of delayed amnesia, delayed neuronal death and changes in acetylcholine concentration induced by carbon monoxide (CO)-exposure in mice. In the test for retention of the passive avoidance task, amnesia was observed 5 and 7 days after CO-exposure when the mice were exposed to CO 1 day after training; in the case when the mice were exposed to CO 5 and 7 days before training, amnesia was also observed in a retention test given 1 day after training. The number of pyramidal cells in the hippocampal CA1 subfield was lower than that of the control 3, 5 and 7 days after CO-exposure. But the neurodegeneration in the parietal cortex, area 1, was not observed until 7 days after CO-exposure. The findings indicated that the amnesia and the neuronal death were produced after a delay when the mice were exposed to CO. In addition, the delayed amnesia was closely related to the delayed neuronal death in the hippocampal CA1 subfield. Moreover, (3H)glutamate and (3H)glycine binding sites did not change after CO-exposure but, 7 days after CO-exposure, the concentration of acetylcholine and the binding of (3H)quinuclidinyl benzilate in the frontal cortex and the striatum were found to have significantly changed, but those in the hippocampus did not show significant change. Therefore, we suggest that delayed amnesia induced by CO-exposure may result from delayed neuronal death in the hippocampal CA1 subfield and dysfunction in the acetylcholinergic neurons, in the frontal cortex, the striatum and/or the hippocampus.

  16. Pinning synchronization of the complex networks with non-delayed and delayed coupling

    International Nuclear Information System (INIS)

    Guo Wanli; Austin, Francis; Chen Shihua; Sun Wen

    2009-01-01

    In this Letter, without assuming the symmetry of the coupling matrix, we investigate the global synchronization of the complex networks with non-delayed and delayed coupling based on the pinning controllers. Some sufficient conditions for the global synchronization by adding linear and adaptive feedback controllers to a part of nodes are obtained. Numerical examples are also provided to demonstrate the effectiveness of the theory.

  17. #FakeNobelDelayReasons

    CERN Multimedia

    2013-01-01

    Tuesday’s hour-long delay of the Nobel Prize in Physics announcement was (and still is) quite the cause for speculation. But on the Twittersphere, it was simply the catalyst for some fantastic puns, so-bad-they're-good physics jokes and other shenanigans. Here are some of our favourite #FakeNobelDelayReasons.    

  18. Delay, doubt, and decision: how delaying a choice reduces the appeal of (descriptively) normative options.

    Science.gov (United States)

    van de Ven, Niels; Gilovich, Thomas; Zeelenberg, Marcel

    2010-04-01

    To help explain a regularity in democratic elections, we examined whether choosing to delay making a choice between a focal option and an alternative tends to make people subsequently less likely to choose what they would otherwise have chosen. The results of two experiments demonstrated that participants who were induced to delay making a decision were indeed less likely to choose the descriptively normative option. An additional experiment that primed a sense of doubt in participants provided support for a self-perception account of this result. Electing to delay making a choice is interpreted as an indication of doubt--doubt that tends to be attributed to the most prominent option. Delay-induced doubt about the normative option makes it less likely to be selected.

  19. Location Estimation using Delayed Measurements

    DEFF Research Database (Denmark)

    Bak, Martin; Larsen, Thomas Dall; Nørgård, Peter Magnus

    1998-01-01

    When combining data from various sensors it is vital to acknowledge possible measurement delays. Furthermore, the sensor fusion algorithm, often a Kalman filter, should be modified in order to handle the delay. The paper examines different possibilities for handling delays and applies a new techn...... technique to a sensor fusion system for estimating the location of an autonomous guided vehicle. The system fuses encoder and vision measurements in an extended Kalman filter. Results from experiments in a real environment are reported...

  20. Barrier and operational risk analysis of hydrocarbon releases (BORA-Release)

    International Nuclear Information System (INIS)

    Sklet, Snorre; Vinnem, Jan Erik; Aven, Terje

    2006-01-01

    This paper presents results from a case study carried out on an offshore oil and gas production platform with the purpose to apply and test BORA-Release, a method for barrier and operational risk analysis of hydrocarbon releases. A description of the BORA-Release method is given in Part I of the paper. BORA-Release is applied to express the platform specific hydrocarbon release frequencies for three release scenarios for selected systems and activities on the platform. The case study demonstrated that the BORA-Release method is a useful tool for analysing the effect on the release frequency of safety barriers introduced to prevent hydrocarbon releases, and to study the effect on the barrier performance of platform specific conditions of technical, human, operational, and organisational risk influencing factors (RIFs). BORA-Release may also be used to analyse the effect on the release frequency of risk reducing measures

  1. Getting by on credit: how district health managers in Ghana cope with the untimely release of funds.

    Science.gov (United States)

    Asante, Augustine D; Zwi, Anthony B; Ho, Maria T

    2006-08-17

    District health systems in Africa depend largely on public funding. In many countries, not only are these funds insufficient, but they are also released in an untimely fashion, thereby creating serious cash flow problems for district health managers. This paper examines how the untimely release of public sector health funds in Ghana affects district health activities and the way district managers cope with the situation. A qualitative approach using semi-structured interviews was adopted. Two regions (Northern and Ashanti) covering the northern and southern sectors of Ghana were strategically selected. Sixteen managers (eight directors of health services and eight district health accountants) were interviewed between 2003/2004. Data generated were analysed for themes and patterns. The results showed that untimely release of funds disrupts the implementation of health activities and demoralises district health staff. However, based on their prior knowledge of when funds are likely to be released, district health managers adopt a range of informal mechanisms to cope with the situation. These include obtaining supplies on credit, borrowing cash internally, pre-purchasing materials, and conserving part of the fourth quarter donor-pooled funds for the first quarter of the next year. While these informal mechanisms have kept the district health system in Ghana running in the face of persistent delays in funding, some of them are open to abuse and could be a potential source of corruption in the health system. Official recognition of some of these informal managerial strategies will contribute to eliminating potential risks of corruption in the Ghanaian health system and also serve as an acknowledgement of the efforts being made by local managers to keep the district health system functioning in the face of budgetary constraints and funding delays. It may boost the confidence of the managers and even enhance service delivery.

  2. Getting by on credit: how district health managers in Ghana cope with the untimely release of funds

    Directory of Open Access Journals (Sweden)

    Ho Maria T

    2006-08-01

    Full Text Available Abstract Background District health systems in Africa depend largely on public funding. In many countries, not only are these funds insufficient, but they are also released in an untimely fashion, thereby creating serious cash flow problems for district health managers. This paper examines how the untimely release of public sector health funds in Ghana affects district health activities and the way district managers cope with the situation. Methods A qualitative approach using semi-structured interviews was adopted. Two regions (Northern and Ashanti covering the northern and southern sectors of Ghana were strategically selected. Sixteen managers (eight directors of health services and eight district health accountants were interviewed between 2003/2004. Data generated were analysed for themes and patterns. Results The results showed that untimely release of funds disrupts the implementation of health activities and demoralises district health staff. However, based on their prior knowledge of when funds are likely to be released, district health managers adopt a range of informal mechanisms to cope with the situation. These include obtaining supplies on credit, borrowing cash internally, pre-purchasing materials, and conserving part of the fourth quarter donor-pooled funds for the first quarter of the next year. While these informal mechanisms have kept the district health system in Ghana running in the face of persistent delays in funding, some of them are open to abuse and could be a potential source of corruption in the health system. Conclusion Official recognition of some of these informal managerial strategies will contribute to eliminating potential risks of corruption in the Ghanaian health system and also serve as an acknowledgement of the efforts being made by local managers to keep the district health system functioning in the face of budgetary constraints and funding delays. It may boost the confidence of the managers and even enhance

  3. Analyzing delay causes in Egyptian construction projects

    Directory of Open Access Journals (Sweden)

    Mohamed M. Marzouk

    2014-01-01

    Full Text Available Construction delays are common problems in civil engineering projects in Egypt. These problems occur frequently during project life-time leading to disputes and litigation. Therefore, it is essential to study and analyze causes of construction delays. This research presents a list of construction delay causes retrieved from literature. The feedback of construction experts was obtained through interviews. Subsequently, a questionnaire survey was prepared. The questionnaire survey was distributed to thirty-three construction experts who represent owners, consultants, and contractor’s organizations. Frequency Index, Severity Index, and Importance Index are calculated and according to the highest values of them the top ten delay causes of construction projects in Egypt are determined. A case study is analyzed and compared to the most important delay causes in the research. Statistical analysis is carried out using analysis of variance ANOVA method to test delay causes, obtained from the survey. The test results reveal good correlation between groups while there is significant difference between them for some delay causes and finally roadmap for prioritizing delay causes groups is presented.

  4. Robust Moving Horizon H∞ Control of Discrete Time-Delayed Systems with Interval Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    F. Yıldız Tascikaraoglu

    2014-01-01

    Full Text Available In this study, design of a delay-dependent type moving horizon state-feedback control (MHHC is considered for a class of linear discrete-time system subject to time-varying state delays, norm-bounded uncertainties, and disturbances with bounded energies. The closed-loop robust stability and robust performance problems are considered to overcome the instability and poor disturbance rejection performance due to the existence of parametric uncertainties and time-delay appeared in the system dynamics. Utilizing a discrete-time Lyapunov-Krasovskii functional, some delay-dependent linear matrix inequality (LMI based conditions are provided. It is shown that if one can find a feasible solution set for these LMI conditions iteratively at each step of run-time, then we can construct a control law which guarantees the closed-loop asymptotic stability, maximum disturbance rejection performance, and closed-loop dissipativity in view of the actuator limitations. Two numerical examples with simulations on a nominal and uncertain discrete-time, time-delayed systems, are presented at the end, in order to demonstrate the efficiency of the proposed method.

  5. A novel delay-dependent criterion for delayed neural networks of neutral type

    International Nuclear Information System (INIS)

    Lee, S.M.; Kwon, O.M.; Park, Ju H.

    2010-01-01

    This Letter considers a robust stability analysis method for delayed neural networks of neutral type. By constructing a new Lyapunov functional, a novel delay-dependent criterion for the stability is derived in terms of LMIs (linear matrix inequalities). A less conservative stability criterion is derived by using nonlinear properties of the activation function of the neural networks. Two numerical examples are illustrated to show the effectiveness of the proposed method.

  6. Reasons for diagnostic delay in gynecological malignancies

    DEFF Research Database (Denmark)

    Vandborg, Mai Partridge; Christensen, René dePont Christensen; Kragstrup, Jakob

    2011-01-01

    (≤ or > 60 years), performance of gynecological examination by the GP and notification of cancer suspicion on first referral from GP’s on the diagnostic delay (short delay ≤90 days and long delay >90 days). Results Across cancer type a median total delay of 101 days was observed. The 10% of women......Aim The primary aim of this study was to identify and describe different delay types in women with gynecologic cancer, and to analyze the relationship between diagnostic delay and a number of characteristics for patients, cancers and the health care system. Setting A cohort study of women newly......) and The Danish Gynecological Cancer Database (DGCD). 161 women were included; ovarian cancer: 63, endometrial cancer: 50, cervical cancer: 34 and vulvar cancer: 14. Outcome measures were different delay types counted in days and the influence of four clinical important variables: Presence of alarm symptoms, age...

  7. Discounting of Monetary Rewards That Are Both Delayed and Probabilistic: Delay and Probability Combine Multiplicatively, Not Additively

    Science.gov (United States)

    Vanderveldt, Ariana; Green, Leonard; Myerson, Joel

    2015-01-01

    The value of an outcome is affected both by the delay until its receipt (delay discounting) and by the likelihood of its receipt (probability discounting). Despite being well-described by the same hyperboloid function, delay and probability discounting involve fundamentally different processes, as revealed, for example, by the differential effects…

  8. NETosis Delays Diabetic Wound Healing in Mice and Humans.

    Science.gov (United States)

    Fadini, Gian Paolo; Menegazzo, Lisa; Rigato, Mauro; Scattolini, Valentina; Poncina, Nicol; Bruttocao, Andrea; Ciciliot, Stefano; Mammano, Fabio; Ciubotaru, Catalin Dacian; Brocco, Enrico; Marescotti, Maria Cristina; Cappellari, Roberta; Arrigoni, Giorgio; Millioni, Renato; Vigili de Kreutzenberg, Saula; Albiero, Mattia; Avogaro, Angelo

    2016-04-01

    Upon activation, neutrophils undergo histone citrullination by protein arginine deiminase (PAD)4, exocytosis of chromatin and enzymes as neutrophil extracellular traps (NETs), and death. In diabetes, neutrophils are primed to release NETs and die by NETosis. Although this process is a defense against infection, NETosis can damage tissue. Therefore, we examined the effect of NETosis on the healing of diabetic foot ulcers (DFUs). Using proteomics, we found that NET components were enriched in nonhealing human DFUs. In an independent validation cohort, a high concentration of neutrophil elastase in the wound was associated with infection and a subsequent worsening of the ulcer. NET components (elastase, histones, neutrophil gelatinase-associated lipocalin, and proteinase-3) were elevated in the blood of patients with DFUs. Circulating elastase and proteinase-3 were associated with infection, and serum elastase predicted delayed healing. Neutrophils isolated from the blood of DFU patients showed an increased spontaneous NETosis but an impaired inducible NETosis. In mice, skin PAD4 activity was increased by diabetes, and FACS detection of histone citrullination, together with intravital microscopy, showed that NETosis occurred in the bed of excisional wounds. PAD4 inhibition by Cl-amidine reduced NETting neutrophils and rescued wound healing in diabetic mice. Cumulatively, these data suggest that NETosis delays DFU healing. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  9. An Experimental Investigation on the Combustion and Heat Release Characteristics of an Opposed-Piston Folded-Cranktrain Diesel Engine

    Directory of Open Access Journals (Sweden)

    Fukang Ma

    2015-06-01

    Full Text Available In opposed-piston folded-cranktrain diesel engines, the relative movement rules of opposed-pistons, combustion chamber components and injector position are different from those of conventional diesel engines. The combustion and heat release characteristics of an opposed-piston folded-cranktrain diesel engine under different operating conditions were investigated. Four phases: ignition delay, premixed combustion, diffusion combustion and after combustion are used to describe the heat release process of the engine. Load changing has a small effect on premixed combustion duration while it influences diffusion combustion duration significantly. The heat release process has more significant isochoric and isobaric combustion which differs from the conventional diesel engine situation, except at high exhaust pressure and temperature, due to its two-stroke and uniflow scavenging characteristics. Meanwhile, a relatively high-quality exhaust heat energy is produced in opposed-piston folded-cranktrain diesel engines.

  10. Nuclear size and cell division delay

    International Nuclear Information System (INIS)

    Bird, R.P.

    1986-01-01

    Radiation-induced division delay has been linked to damage at the nuclear envelope. Further, cells in G 2 phase are drastically arrested by high LET radiation such that single particles traversing cell nuclei may produce measurable division delay. A modest effort was initiated using two related cell lines of different size, near-diploid cells and near-tetraploid cells of Chinese hamster origin, to compare their sensitivity for radiation-induced division delay. If the nuclear surface is the critical target, then a larger nuclear cross-section presented to an alpha-particle beam should exhibit delay induced by a lesser particle fluence. Preliminary estimates of the extent of delay in asynchronous cultures following low doses of gamma-irradiation or of alpha-irradiation were made by in-situ observation of the time of onset of mitosis and by fixation and staining of cultures to determine the mitotic index as a function of time after irradiation. The basic approach to evaluating division delay will be to use Colecemid to accumulate mitotic cells over a period of time

  11. A Polynomial Estimate of Railway Line Delay

    DEFF Research Database (Denmark)

    Cerreto, Fabrizio; Harrod, Steven; Nielsen, Otto Anker

    2017-01-01

    Railway service may be measured by the aggregate delay over a time horizon or due to an event. Timetables for railway service may dampen aggregate delay by addition of additional process time, either supplement time or buffer time. The evaluation of these variables has previously been performed...... by numerical analysis with simulation. This paper proposes an analytical estimate of aggregate delay with a polynomial form. The function returns the aggregate delay of a railway line resulting from an initial, primary, delay. Analysis of the function demonstrates that there should be a balance between the two...

  12. Delayed Ejaculation

    Science.gov (United States)

    ... cases, it is due to a combination of physical and psychological concerns. Psychological causes of delayed ejaculation include: Depression, anxiety or other mental health conditions Relationship problems due to stress, poor communication ...

  13. Time Delay Estimation Algoritms for Echo Cancellation

    Directory of Open Access Journals (Sweden)

    Kirill Sakhnov

    2011-01-01

    Full Text Available The following case study describes how to eliminate echo in a VoIP network using delay estimation algorithms. It is known that echo with long transmission delays becomes more noticeable to users. Thus, time delay estimation, as a part of echo cancellation, is an important topic during transmission of voice signals over packetswitching telecommunication systems. An echo delay problem associated with IP-based transport networks is discussed in the following text. The paper introduces the comparative study of time delay estimation algorithm, used for estimation of the true time delay between two speech signals. Experimental results of MATLab simulations that describe the performance of several methods based on cross-correlation, normalized crosscorrelation and generalized cross-correlation are also presented in the paper.

  14. Ca(2+ release events in cardiac myocytes up close: insights from fast confocal imaging.

    Directory of Open Access Journals (Sweden)

    Vyacheslav M Shkryl

    Full Text Available The spatio-temporal properties of Ca(2+ transients during excitation-contraction coupling and elementary Ca(2+ release events (Ca(2+ sparks were studied in atrial and ventricular myocytes with ultra-fast confocal microscopy using a Zeiss LSM 5 LIVE system that allows sampling rates of up to 60 kHz. Ca(2+ sparks which originated from subsarcolemmal junctional sarcoplasmic reticulum (j-SR release sites in atrial myocytes were anisotropic and elongated in the longitudinal direction of the cell. Ca(2+ sparks in atrial cells originating from non-junctional SR and in ventricular myocytes were symmetrical. Ca(2+ spark recording in line scan mode at 40,000 lines/s uncovered step-like increases of [Ca(2+]i. 2-D imaging of Ca(2+ transients revealed an asynchronous activation of release sites and allowed the sequential recording of Ca(2+ entry through surface membrane Ca(2+ channels and subsequent activation of Ca(2+-induced Ca(2+ release. With a latency of 2.5 ms after application of an electrical stimulus, Ca(2+ entry could be detected that was followed by SR Ca(2+ release after an additional 3 ms delay. Maximum Ca(2+ release was observed 4 ms after the beginning of release. The timing of Ca(2+ entry and release was confirmed by simultaneous [Ca(2+]i and membrane current measurements using the whole cell voltage-clamp technique. In atrial cells activation of discrete individual release sites of the j-SR led to spatially restricted Ca(2+ release events that fused into a peripheral ring of elevated [Ca(2+]i that subsequently propagated in a wave-like fashion towards the center of the cell. In ventricular myocytes asynchronous Ca(2+ release signals from discrete sites with no preferential subcellular location preceded the whole-cell Ca(2+ transient. In summary, ultra-fast confocal imaging allows investigation of Ca(2+ signals with a time resolution similar to patch clamp technique, however in a less invasive fashion.

  15. Delayed growth

    Science.gov (United States)

    ... Slow rate of growth; Retarded growth and development; Growth delay Images Toddler development References Cooke DW, Divall SA, Radovick S. Normal and aberrant growth in children. In: Melmed S, Polonsky KS, Larsen PR, ...

  16. Topology identification of the complex networks with non-delayed and delayed coupling

    International Nuclear Information System (INIS)

    Guo Wanli; Chen Shihua; Sun Wen

    2009-01-01

    In practical situation, there exists many uncertain information in complex networks, such as the topological structures. So the topology identification is an important issue in the research of the complex networks. Based on LaSalle's invariance principle, in this Letter, an adaptive controlling method is proposed to identify the topology of a weighted general complex network model with non-delayed and delayed coupling. Finally, simulation results show that the method is effective.

  17. Delay-independent stability of genetic regulatory networks.

    Science.gov (United States)

    Wu, Fang-Xiang

    2011-11-01

    Genetic regulatory networks can be described by nonlinear differential equations with time delays. In this paper, we study both locally and globally delay-independent stability of genetic regulatory networks, taking messenger ribonucleic acid alternative splicing into consideration. Based on nonnegative matrix theory, we first develop necessary and sufficient conditions for locally delay-independent stability of genetic regulatory networks with multiple time delays. Compared to the previous results, these conditions are easy to verify. Then we develop sufficient conditions for global delay-independent stability for genetic regulatory networks. Compared to the previous results, this sufficient condition is less conservative. To illustrate theorems developed in this paper, we analyze delay-independent stability of two genetic regulatory networks: a real-life repressilatory network with three genes and three proteins, and a synthetic gene regulatory network with five genes and seven proteins. The simulation results show that the theorems developed in this paper can effectively determine the delay-independent stability of genetic regulatory networks.

  18. Behavioral effects of delayed timeouts from reinforcement.

    Science.gov (United States)

    Byrne, Tom; Poling, Alan

    2017-03-01

    Timeouts are sometimes used in applied settings to reduce target responses, and in some circumstances delays are unavoidably imposed between the onset of a timeout and the offset of the response that produces it. The present study examined the effects of signaled and unsignaled timeouts in rats exposed to concurrent fixed-ratio 1 fixed-ratio 1 schedules of food delivery, where each response on one lever, the location of which changed across conditions, produced both food and a delayed 10-s timeout. Delays of 0 to 38 s were examined. Delayed timeouts often, but not always, substantially reduced the number of responses emitted on the lever that produced timeouts relative to the number emitted on the lever that did not produce timeouts. In general, greater sensitivity was observed to delayed timeouts when they were signaled. These results demonstrate that delayed timeouts, like other delayed consequences, can affect behavior, albeit less strongly than immediate consequences. © 2017 Society for the Experimental Analysis of Behavior.

  19. Exponential Antisynchronization Control of Stochastic Memristive Neural Networks with Mixed Time-Varying Delays Based on Novel Delay-Dependent or Delay-Independent Adaptive Controller

    Directory of Open Access Journals (Sweden)

    Minghui Yu

    2017-01-01

    Full Text Available The global exponential antisynchronization in mean square of memristive neural networks with stochastic perturbation and mixed time-varying delays is studied in this paper. Then, two kinds of novel delay-dependent and delay-independent adaptive controllers are designed. With the ability of adapting to environment changes, the proposed controllers can modify their behaviors to achieve the best performance. In particular, on the basis of the differential inclusions theory, inequality theory, and stochastic analysis techniques, several sufficient conditions are obtained to guarantee the exponential antisynchronization between the drive system and response system. Furthermore, two numerical simulation examples are provided to the validity of the derived criteria.

  20. Permissible Delay in Payments

    Directory of Open Access Journals (Sweden)

    Yung-Fu Huang

    2007-01-01

    Full Text Available The main purpose of this paper wants to investigate the optimal retailer's lot-sizing policy with two warehouses under partially permissible delay in payments within the economic order quantity (EOQ framework. In this paper, we want to extend that fully permissible delay in payments to the supplier would offer the retailer partially permissible delay in payments. That is, the retailer must make a partial payment to the supplier when the order is received. Then the retailer must pay off the remaining balance at the end of the permissible delay period. In addition, we want to add the assumption that the retailer's storage space is limited. That is, the retailer will rent the warehouse to store these exceeding items when the order quantity is larger than retailer's storage space. Under these conditions, we model the retailer's inventory system as a cost minimization problem to determine the retailer's optimal cycle time and optimal order quantity. Three theorems are developed to efficiently determine the optimal replenishment policy for the retailer. Finally, numerical examples are given to illustrate these theorems and obtained a lot of managerial insights.

  1. Delayed Release from Proactive Interference with Meaningful Material: How Much Do We Remember After Reading Brief Prose Passages?

    Science.gov (United States)

    Blumenthal, Gary B.; Robbins, Donald

    1977-01-01

    Three experiments were conducted, investigating the buildup of and the release from proactive interference, in which the stimulus materials were brief prose passages about specific topics. Each passage was followed by a multiple-choice test, and then a final test on all the passages read was given. Implications of the data for standardized tests…

  2. Periodic flows to chaos in time-delay systems

    CERN Document Server

    Luo, Albert C J

    2017-01-01

    This book for the first time examines periodic motions to chaos in time-delay systems, which exist extensively in engineering. For a long time, the stability of time-delay systems at equilibrium has been of great interest from the Lyapunov theory-based methods, where one cannot achieve the ideal results. Thus, time-delay discretization in time-delay systems was used for the stability of these systems. In this volume, Dr. Luo presents an accurate method based on the finite Fourier series to determine periodic motions in nonlinear time-delay systems. The stability and bifurcation of periodic motions are determined by the time-delayed system of coefficients in the Fourier series and the method for nonlinear time-delay systems is equivalent to the Laplace transformation method for linear time-delay systems. Facilitates discovery of analytical solutions of nonlinear time-delay systems; Illustrates bifurcation trees of periodic motions to chaos; Helps readers identify motion complexity and singularity; Explains pro...

  3. Delay Variation Model with Two Service Queues

    Directory of Open Access Journals (Sweden)

    Filip Rezac

    2010-01-01

    Full Text Available Delay in VoIP technology is very unpleasant issue and therefore a voice packets prioritization must be ensured. To maintain the high call quality a maximum information delivery time from the sender to the recipient is set to 150 ms. This paper focuses on the design of a mathematical model of end-to-end delay of a VoIP connection, in particular on a delay variation. It describes all partial delay components and mechanisms, their generation, facilities and mathematical formulations. A new approach to the delay variation model is presented and its validation has been done by experimention.

  4. Goodwin accelerator model revisited with fixed time delays

    Science.gov (United States)

    Matsumoto, Akio; Merlone, Ugo; Szidarovszky, Ferenc

    2018-05-01

    Dynamics of Goodwin's accelerator business cycle model is reconsidered. The model is characterized by a nonlinear accelerator and an investment time delay. The role of the nonlinearity for the birth of persistent oscillations is fully discussed in the existing literature. On the other hand, not much of the role of the delay has yet been revealed. The purpose of this paper is to show that the delay really matters. In the original framework of Goodwin [6], it is first demonstrated that there is a threshold value of the delay: limit cycles arise for smaller values than the threshold and so do sawtooth oscillations for larger values. In the extended framework in which a consumption or saving delay, in addition to the investment delay, is introduced, three main results are demonstrated under assumption of the identical length of investment and consumption delays. The dynamics with consumption delay is basically the same as that of the single delay model. Second, in the case of saving delay, the steady state can coexist with the stable and unstable limit cycles in the stable case. Third, in the unstable case, there is an interval of delay in which the limit cycle or the sawtooth oscillation emerges depending on the choice of the constant initial function.

  5. The reasons for delay lumbar puncture

    Directory of Open Access Journals (Sweden)

    MH. Lotfi

    2017-04-01

    Full Text Available Early diagnosis of meningitis and encephalitis and prompt initiation of appropriate therapy is vital and any delay will lead to high mortality and serious and permanent morbidity. The main purpose of this study was to evaluate the management of 220 patients with suspected central nervous system (CNS infections (meningitis and encephalitis to determine the percentage of patients’ suspected CNS infection undergo lumbar puncture in acceptable time (in accordance with conventional algorithms. In this descriptive study, patients with suspected CNS infections admitted to Bu-Ali and Qods hospitals, in the period July 2013 to December 2015 were studied. Information of 220 patients was collected. Continuous variables were summarized as means ± standard deviation and categorical variables as frequencies and percentages. Lumbar puncture (LP in patients was delayed in 200 cases (91%. Most common causes of delay in performing LP were prolongation of the process of determining patient needs to puncture, satisfying patients, CT scan delay and the delay in allowing LP by neurologist. In this study, delaying LP rate was higher than other studies. It seems certain pattern in assistants’ visits for counseling. CT requests and neurologic consultation before LP performed for all adult patients.

  6. Delays and networked control systems

    CERN Document Server

    Hetel, Laurentiu; Daafouz, Jamal; Johansson, Karl

    2016-01-01

    This edited monograph includes state-of-the-art contributions on continuous time dynamical networks with delays. The book is divided into four parts. The first part presents tools and methods for the analysis of time-delay systems with a particular attention on control problems of large scale or infinite-dimensional systems with delays. The second part of the book is dedicated to the use of time-delay models for the analysis and design of Networked Control Systems. The third part of the book focuses on the analysis and design of systems with asynchronous sampling intervals which occur in Networked Control Systems. The last part of the book exposes several contributions dealing with the design of cooperative control and observation laws for networked control systems. The target audience primarily comprises researchers and experts in the field of control theory, but the book may also be beneficial for graduate students. .

  7. A scheme to expand the delay-bandwidth product in the resonator-based delay lines by optical OFDM technique

    DEFF Research Database (Denmark)

    Zhu, Jiangbo; Tao, Li; Zhang, Ziran

    2013-01-01

    We propose a novel scheme to expand the inherent limit in the product of the optical delay and the transmission bandwidth in resonator-based delay lines, with the optical orthogonal frequency division multiplexing (OOFDM) technique. The optical group delay properties of a single ring resonator we...

  8. Suppression of postmitochondrial signaling and delayed response to UV-induced nuclear apoptosis in HeLa cells

    International Nuclear Information System (INIS)

    Sasai, Kaori; Yajima, Hirohiko; Suzuki, Fumio

    2002-01-01

    Activation of postmitochondrial pathways by UV irradiation was examined using mouse lymphoma 3SB and human leukemic Jurkat cells and two human carcinoma cell lines (HeLa and MCF-7). Exposure of 3SB and Jurkat cells resulted in large amounts of cytochrome c and apoptosis-inducing factor (AIF) being released into the cytosol, and a clear laddering pattern of DNA fragments was observed within 3 h of incubation after irradiation. Simultaneously, activation of caspase-9 and its downstream caspases was detected. HeLa and MCF-7 cells also showed extensive release of mitochondrial factors and caspase-9 activation at 4 to 6 h after exposure, but apoptotic nuclear changes appeared much later. Compared with 3SB and Jurkat cells, these carcinoma cell lines exhibited reduced activation of caspase-9-like proteolytic activity by UV radiation, and levels of caspase-3-like activity in HeLa cells were extremely low, similar to those in caspase-3-deficient MCF-7 cells. These results suggest that the delayed response to UV-induced nuclear apoptosis in HeLa cells is due to a reduced activation of the caspase cascade downstream of cytochrome c release and suppression of caspase-3 activity. (author)

  9. Maternal Obesity: Risks for Developmental Delays in Early Childhood.

    Science.gov (United States)

    Duffany, Kathleen O'Connor; McVeigh, Katharine H; Kershaw, Trace S; Lipkind, Heather S; Ickovics, Jeannette R

    2016-02-01

    To assess the risk for neurodevelopmental delays for children of mothers who were obese (≥200 pounds) prior to pregnancy, and to characterize delays associated with maternal obesity among children referred to and found eligible to receive Early Intervention Program services. We conducted a retrospective cohort study (N = 541,816) using a population-based New York City data warehouse with linked birth and Early Intervention data. Risks for children suspected of a delay and 'significantly delayed', with two moderate or one severe delay, were calculated. Among the group of children eligible by delay for Early Intervention, analyses assessed risk for being identified with a moderate-to-severe delay across each of five functional domains as well as risks for multiple delays. Children of mothers who were obese were more likely to be suspected of a delay (adjusted RR 1.19 [CI 1.15-1.22]) and borderline association for 'significantly delayed' (adjusted RR 1.01 [CI 1.00-1.02). Among children eligible by delay, children of mothers who were obese evidenced an increased risk for moderate-to-severe cognitive (adjusted RR 1.04 [CI 1.02-1.07]) and physical (adjusted RR 1.04 [CI 1.01-1.08]) delays and for global developmental delay (adjusted RR 1.05 [CI 1.01-1.08]). Maternal obesity is associated with increased risk of developmental delay in offspring. Among children with moderate or severe delays, maternal obesity is associated with increased risk of cognitive and physical delays as well as with increased risk for global developmental delay. While causation remains uncertain, this adds to the growing body of research reporting an association between maternal obesity and neurodevelopmental delays in offspring.

  10. Delays in Building Construction Projects in Ghana

    Directory of Open Access Journals (Sweden)

    Adwoa B Agyakwah-Baah

    2010-07-01

    Full Text Available This study investigates the causes of delay of building construction projects in Ghana to determine the most important according to the key project participants; clients, consultants, and contractors. Thirty-two possible causes of delay were identified from the literature and semi-structured interviews of 15 key players in the implementation process. These delay factors were further categorised into nine major groups. The list of delay causes was subjected to a questionnaire survey for the identification of the most important causes of delay. The field survey included 130 respondents made up of 39 contractors, 37 clients and 54 consultants. The relative importance of the individual causes and the groups were calculated and ranked by their relative importance index. The overall results of the study indicate that the respondents generally agree that financial group factors ranked highest among the major factors causing delay in construction projects in Ghana. The financial group factors were delay in honouring payment certificates, difficulty in accessing credit and fluctuation in prices. Materials group factors are second followed by scheduling and controlling factors.

  11. Picosecond resolution programmable delay line

    International Nuclear Information System (INIS)

    Suchenek, Mariusz

    2009-01-01

    The note presents implementation of a programmable delay line for digital signals. The tested circuit has a subnanosecond delay range programmable with a resolution of picoseconds. Implementation of the circuit was based on low-cost components, easily available on the market. (technical design note)

  12. Electrically tunable photonic true-time-delay line.

    Science.gov (United States)

    Barmenkov, Yuri O; Cruz, José Luis; Díez, Antonio; Andrés, Miguel V

    2010-08-16

    We present a new application of the acousto-optic superlattice modulation of a fiber Bragg grating based on the dynamic phase and group delay properties of this fiber-optic component. We demonstrate a tunable photonic true-time-delay line based on the group delay change of the light reflected from the grating sidebands. The delay is electrically tuned by adjusting the voltage applied to a piezoelectric transducer that generates the acoustic wave propagating along the grating. In our experiments, a true-time delay of 400 ps is continuously adjusted (300 ps within the 3 dB amplitude range of the first sideband), using a 12 cm long uniform grating.

  13. Chaos control in delayed chaotic systems via sliding mode based delayed feedback

    Energy Technology Data Exchange (ETDEWEB)

    Vasegh, Nastaran [Faculty of Electrical Engineering, K.N. Toosi University of Technology, Seyed Khandan Bridge, Shariati St. 16314, P.O. Box 16315-1355, Tehran (Iran, Islamic Republic of)], E-mail: vasegh@eetd.kntu.ac.ir; Sedigh, Ali Khaki [Faculty of Electrical Engineering, K.N. Toosi University of Technology, Seyed Khandan Bridge, Shariati St. 16314, P.O. Box 16315-1355, Tehran (Iran, Islamic Republic of)

    2009-04-15

    This paper investigates chaos control for scalar delayed chaotic systems using sliding mode control strategy. Sliding surface design is based on delayed feedback controller. It is shown that the proposed controller can achieve stability for an arbitrary unstable fixed point (UPF) or unstable periodic orbit (UPO) with arbitrary period. The chaotic system used in this study to illustrate the theoretical concepts is the well known Mackey-Glass model. Simulation results show the effectiveness of the designed nonlinear sliding mode controller.

  14. Chaos control in delayed chaotic systems via sliding mode based delayed feedback

    International Nuclear Information System (INIS)

    Vasegh, Nastaran; Sedigh, Ali Khaki

    2009-01-01

    This paper investigates chaos control for scalar delayed chaotic systems using sliding mode control strategy. Sliding surface design is based on delayed feedback controller. It is shown that the proposed controller can achieve stability for an arbitrary unstable fixed point (UPF) or unstable periodic orbit (UPO) with arbitrary period. The chaotic system used in this study to illustrate the theoretical concepts is the well known Mackey-Glass model. Simulation results show the effectiveness of the designed nonlinear sliding mode controller.

  15. Global exponential stability of octonion-valued neural networks with leakage delay and mixed delays.

    Science.gov (United States)

    Popa, Călin-Adrian

    2018-06-08

    This paper discusses octonion-valued neural networks (OVNNs) with leakage delay, time-varying delays, and distributed delays, for which the states, weights, and activation functions belong to the normed division algebra of octonions. The octonion algebra is a nonassociative and noncommutative generalization of the complex and quaternion algebras, but does not belong to the category of Clifford algebras, which are associative. In order to avoid the nonassociativity of the octonion algebra and also the noncommutativity of the quaternion algebra, the Cayley-Dickson construction is used to decompose the OVNNs into 4 complex-valued systems. By using appropriate Lyapunov-Krasovskii functionals, with double and triple integral terms, the free weighting matrix method, and simple and double integral Jensen inequalities, delay-dependent criteria are established for the exponential stability of the considered OVNNs. The criteria are given in terms of complex-valued linear matrix inequalities, for two types of Lipschitz conditions which are assumed to be satisfied by the octonion-valued activation functions. Finally, two numerical examples illustrate the feasibility, effectiveness, and correctness of the theoretical results. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Corticotropin-Releasing Factor Receptors Modulate Oxytocin Release in the Dorsolateral Bed Nucleus of the Stria Terminalis (BNST in Male Rats

    Directory of Open Access Journals (Sweden)

    Daisy Martinon

    2018-03-01

    Full Text Available The neuropeptide oxytocin (OT plays an important role in the regulation of social and anxiety-like behavior. Our previous studies have shown that OT neurons send projections from the hypothalamus to the dorsolateral bed nucleus of the stria terminalis (BNSTdl, a forebrain region critically involved in the modulation of anxiety-like behavior. Importantly, these OT terminals in the BNSTdl express presynaptic corticotropin releasing factor (CRF receptor type 2 (CRFR2. This suggests that CRFR2 might be involved in the modulation of OT release. To test this hypothesis, we measured OT content in microdialysates collected from the BNSTdl of freely-moving male Sprague-Dawley rats following the administration of a selective CRFR2 agonist (Urocortin 3 or antagonist (Astressin 2B, As2B. To determine if type 1 CRF receptors (CRFR1 are also involved, we used selective CRFR1 antagonist (NBI35965 as well as CRF, a putative ligand of both CRFR1 and CRFR2. All compounds were delivered directly into the BNSTdl via reverse dialysis. OT content in the microdialysates was measured with highly sensitive and selective radioimmunoassay. Blocking CRFR2 with As2B caused an increase in OT content in BNSTdl microdialysates, whereas CRFR2 activation by Urocortin 3 did not have an effect. The As2B-induced increase in OT release was blocked by application of the CRFR1 antagonist demonstrating that the effect was dependent on CRFR1 transmission. Interestingly, CRF alone caused a delayed increase in OT content in BNSTdl microdialysates, which was dependent on CRF2 but not CRF1 receptors. Our results suggest that members of the CRF peptide family modulate OT release in the BNSTdl via a fine-tuned mechanism that involves both CRFR1 and CRFR2. Further exploration of mechanisms by which endogenous OT system is modulated by CRF peptide family is needed to better understand the role of these neuropeptides in the regulation of anxiety and the stress response.

  17. Data Assimilation by delay-coordinate nudging

    Science.gov (United States)

    Pazo, Diego; Lopez, Juan Manuel; Carrassi, Alberto

    2016-04-01

    A new nudging method for data assimilation, delay-coordinate nudging, is presented. Delay-coordinate nudging makes explicit use of present and past observations in the formulation of the forcing driving the model evolution at each time-step. Numerical experiments with a low order chaotic system show that the new method systematically outperforms standard nudging in different model and observational scenarios, also when using an un-optimized formulation of the delay-nudging coefficients. A connection between the optimal delay and the dominant Lyapunov exponent of the dynamics is found based on heuristic arguments and is confirmed by the numerical results, providing a guideline for the practical implementation of the algorithm. Delay-coordinate nudging preserves the easiness of implementation, the intuitive functioning and the reduced computational cost of the standard nudging, making it a potential alternative especially in the field of seasonal-to-decadal predictions with large Earth system models that limit the use of more sophisticated data assimilation procedures.

  18. Effect of caffeine on radiation-induced mitotic delay: delayed expression of G2 arrest

    International Nuclear Information System (INIS)

    Rowley, R.; Zorch, M.; Leeper, D.B.

    1984-01-01

    In the presence of 5 mM caffeine, irradiated (1.5 Gy) S and G 2 cells progressed to mitosis in register and without arrest in G 2 . Caffeine (5 mM) markedly reduced mitotic delay even after radiation doses up to 20 Gy. When caffeine was removed from irradiated (1.5 Gy) and caffeine-treated cells, a period of G 2 arrest followed, similar in length to that produced by radiation alone. The arrest expressed was independent of the duration of the caffeine treatment for exposures up to 3 hr. The similarity of the response to the cited effects of caffeine on S-phase delay suggests a common basis for delay induction in S and G 2 phases

  19. Facilitating tolerance of delayed reinforcement during functional communication training.

    Science.gov (United States)

    Fisher, W W; Thompson, R H; Hagopian, L P; Bowman, L G; Krug, A

    2000-01-01

    Few clinical investigations have addressed the problem of delayed reinforcement. In this investigation, three individuals whose destructive behavior was maintained by positive reinforcement were treated using functional communication training (FCT) with extinction (EXT). Next, procedures used in the basic literature on delayed reinforcement and self-control (reinforcer delay fading, punishment of impulsive responding, and provision of an alternative activity during reinforcer delay) were used to teach participants to tolerate delayed reinforcement. With the first case, reinforcer delay fading alone was effective at maintaining low rates of destructive behavior while introducing delayed reinforcement. In the second case, the addition of a punishment component reduced destructive behavior to near-zero levels and facilitated reinforcer delay fading. With the third case, reinforcer delay fading was associated with increases in masturbation and head rolling, but prompting and praising the individual for completing work during the delay interval reduced all problem behaviors and facilitated reinforcer delay fading.

  20. Controlled copper ion release from phosphate-based glasses improves human umbilical vein endothelial cell survival in a reduced nutrient environment.

    Science.gov (United States)

    Stähli, Christoph; Muja, Naser; Nazhat, Showan N

    2013-02-01

    The success of tissue engineering is dependent on rapid scaffold vascularization after engraftment. Copper ions are well known to be angiogenic but exhibit cytotoxicity at elevated doses. The high sensitivity to copper concentration underlines the need of a controlled release mechanism. This study investigated the effect of copper ions released from phosphate-based glasses (PGs) on human umbilical vein endothelial cells (HUVECs) under standard growth conditions (SGC), as well as in a reduced nutrient environment (RNE) with decreased bovine serum and growth factor concentrations to approximate conditions in the core of large volume scaffolds where nutrient diffusion is limited. Initially, HUVECs were exposed to a range of CuCl(2) concentrations in order to identify an optimal response in terms of their metabolism, viability, and apoptotic activity. Under SGC, HUVEC metabolic activity and viability were reduced in a dose-dependent manner in the presence of 0.44-12 ppm Cu(2+). In contrast, HUVEC death induced by the RNE was delayed by an optimal dose of 4 ppm Cu(2+), which was associated with a down-regulation of apoptosis as evidenced by caspase-3/7 activity. Copper ion release from soluble PGs of the formulation 50P(2)O(5)-30CaO-(20-x)Na(2)O-xCuO [mol%] (x=0, 1, 5 and 10) demonstrated a controllable increase with CuO content. The presence of 4 ppm copper ions released from the 10% CuO PG composition reproduced the delay in HUVEC death in the RNE, suggesting the potential of these materials to extend survival of transplanted endothelial cells in large volume scaffolds.

  1. Mathematical Representation of VoIP Connection Delay

    Directory of Open Access Journals (Sweden)

    M. Halas

    2007-09-01

    Full Text Available The main topic of this article is to define mathematical formulation of VoIP connection delay model. It handles about all partial delay components, the mechanism of their generation, facilities and their mathematical formulation. Thereafter based on mathematical formulation of all partial delay components, the final mathematical model of whole VoIP call delay is created. In conclusion of this article the results of the designed mathematical model are compared with the experimentally gained results.

  2. Delays in the management of retroperitoneal sarcomas

    DEFF Research Database (Denmark)

    Seinen, Jojanneke; Almquist, Martin; Styring, Emelie

    2010-01-01

    Retroperitoneal sarcomas are rare and treatment should optimally be centralized. Despite successful centralization with 90% of the patients referred prior to surgery, delays occur, which led us to assess lead times in a population-based series. Method. Patients diagnosed with retroperitoneal...... sarcoma in the southern Sweden health care region 2003-2009 were eligible for the study. Data on referrals and diagnostic investigations were collected from clinical files from primary health care, local hospitals, and from the sarcoma centre. Lead times were divided into patient delays and health care...... delays caused by primary health care, local hospitals, or procedures at the sarcoma centre. Results. Complete data were available from 33 patients and demonstrated a median patient delay of 23¿days (0-17¿months) and median health care delay of 94¿days (1-40¿months) with delays of median 15¿days...

  3. Delay Tolerance: A Therapeutic Possibility for AD/HD?

    Directory of Open Access Journals (Sweden)

    Edmund J. S. Sonuga-Barke

    2004-01-01

    on these two insights to explore the possibility that the motivational alterations underpinning delay aversion can be modified through specific training regimes in a way equivalent to that found with executive and attentional training. The requirements for such an approach are set out. Delay fading is proposed as a possible basis for reorganizing delay experience, altering the incentive value of delay (e.g., increasing tolerance for delay, thereby reducing AD/HD symptoms.

  4. Delay-dependent working memory impairment in young-adult and aged 5-HT1BKO mice as assessed in a radial-arm water maze.

    Science.gov (United States)

    Wolff, Mathieu; Benhassine, Narimane; Costet, Pierre; Hen, Rene; Segu, Louis; Buhot, Marie-Christine

    2003-01-01

    Serotonin (5-HT) plays a modulatory role in mnemonic functions, especially by interacting with the cholinergic system. The 5-HT1B receptor is a key target of this interaction. The 5-HT1B receptor knockout mice were found previously to exhibit a facilitation in hippocampal-dependent spatial reference memory learning. In the present study, we submitted mice to a delayed spatial working memory task, allowing the introduction of various delays between an exposure trial and a test trial. The 5-HT1BKO and wild-type mice learned the task in a radial-arm water maze (returning to the most recent presented arm containing the escape platform), and exhibited a high level of performance at delays of 0 and 5 min. However, at the delay of 60 min, only 5-HT1BKO mice exhibited an impairment. At a delay of 90 min, all mice were impaired. Treatment by scopolamine (0.8 mg/kg) induced the same pattern of performance in wild type as did the mutation for short (5 min, no impairment) and long (60 min, impairment) delays. The 22-month-old wild-type and knockout mice exhibited an impairment at short delays (5 and 15 min). The effect of the mutation affected both young-adult and aged mice at delays of 15, 30, and 60 min. Neurobiological data show that stimulation of the 5-HT1B receptor inhibits the release of acetylcholine in the hippocampus, but stimulates this in the frontal cortex. This dual function might, at least in part, explain the opposite effect of the mutation on reference memory (facilitation) and delay-dependent working memory (impairment). These results support the idea that cholinergic-serotonergic interactions play an important role in memory processes.

  5. A Delay Line for Compression of Electromagnetic Pulses

    International Nuclear Information System (INIS)

    Pchelnikov, Yuriy N.; Nyce, David S.

    2003-01-01

    A novel method to obtain an electromagnetic signal delay is described. It is shown that the positive magnetic and electric coupling between impedance conductors produces an increase in the time delay. It is also shown that the increase in delay time is obtained without additional attenuation. This allows a reduction in electromagnetic losses, by a factor of several times, for a delay time. An approximate analysis of electromagnetic delay lines based on coupled impedance conductors with 'spiral' and 'meander' patterns allowed obtaining very simple expressions for the wave deceleration factor, wave impedance, and attenuation factor. The results of the analysis are confirmed by the results of measurements. It is shown that a delay line based on counter-wound radial spirals can be successfully used for compression of electromagnetic pulses. Although the offered delay line was designed to operate with a relatively small signal, the analysis of the 'coupling effect', taking place in this delay line, might be useful in devices for compression of high-power microwave pulses

  6. Delayed brain radiation necrosis: pathological review and new molecular targets for treatment.

    Science.gov (United States)

    Furuse, Motomasa; Nonoguchi, Naosuke; Kawabata, Shinji; Miyatake, Shin-Ichi; Kuroiwa, Toshihiko

    2015-12-01

    Delayed radiation necrosis is a well-known adverse event following radiotherapy for brain diseases and has been studied since the 1930s. The primary pathogenesis is thought to be the direct damage to endothelial and glial cells, particularly oligodendrocytes, which causes vascular hyalinization and demyelination. This primary pathology leads to tissue inflammation and ischemia, inducing various tissue protective responses including angiogenesis. Macrophages and lymphocytes then infiltrate the surrounding areas of necrosis, releasing inflammatory cytokines such as interleukin (IL)-1α, IL-6, and tumor necrosis factor (TNF)-α. Microglia also express these inflammatory cytokines. Reactive astrocytes play an important role in angiogenesis, expressing vascular endothelial growth factor (VEGF). Some chemokine networks, like the CXCL12/CXCR4 axis, are upregulated by tissue inflammation. Hypoxia may mediate the cell-cell interactions among reactive astrocytes, macrophages, and microglial cells around the necrotic core. Recently, bevacizumab, an anti-VEGF antibody, has demonstrated promising results as an alternative treatment for radiation necrosis. The importance of VEGF in the pathophysiology of brain radiation necrosis is being recognized. The discovery of new molecular targets could facilitate novel treatments for radiation necrosis. This literature review will focus on recent work characterizing delayed radiation necrosis in the brain.

  7. Development of paradigm for the study of amino acid neurotransmitter release in human autopsy brain samples

    International Nuclear Information System (INIS)

    Kuo, K.-W.; Dodd, P.R.

    2001-01-01

    Full text: This study attempted to establish a release protocol to characterize both the vesicular and cytoplasmic components of amino acid transmitter release in human synaptosomes. Experiments with rat synaptosomes showed that, with depolarizing concentrations of K + ions, vesicular release could be successfully differentiated from cytoplasmic release for preloaded L-[ 3 H ]glutamate and [ 14 C ]GABA. However, human tissue studies did not give clear-cut results. Experiments were carried out to optimize the release paradigm as well as to improve the vesicular uptake of labeled transmitters. A 'pulse- chase' protocol, with an unlabelled D-aspartate chase, was performed in human tissue samples in order to enhance the L-[ 3 H ] glutamate release signal derived from exocytosis by removing the cytoplasmic pool of L-[ 3 H ] glutamate first. However, the results showed that total release was not enhanced effectively in comparison with the non-pulse-chase protocol. In brief, the pulse-chase protocol did not build up the vesicular pool of L-[ 3 H ]glutamate, though the cytoplasmic L- [ 3 H ] glutamate pool was effectively depressed by D-aspartate. Further studies applied 4- aminopyridine (4-AP) to trigger release, to circumvent the problem of the reversal of plasma membrane transporters caused by raised K + ion concentrations. The results showed that the application of 4-AP elicited the release of amino acid transmitters from rat synaptosomes, but failed to produce successful release signals in the human tissue experiments. Our findings suggest that the vesicular compartment may be impaired by freezing and affected by post-mortem delay (PMD). Rat studies showed that the freezing step had a major effect on Ca 2+-dependent release, as less L- [3 H ]glutamate and [ 14 C ]GABA were released from the frozen rat tissue preparations. Moreover, there was an indication of a decline in L-[ 3 H ]glutamate release with increasing PMD. Copyright (2001) Australian Neuroscience Society

  8. An approach to normal forms of Kuramoto model with distributed delays and the effect of minimal delay

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Ben, E-mail: niubenhit@163.com [Department of Mathematics, Harbin Institute of Technology, Weihai 264209 (China); Guo, Yuxiao [Department of Mathematics, Harbin Institute of Technology, Weihai 264209 (China); Jiang, Weihua [Department of Mathematics, Harbin Institute of Technology, Harbin 150001 (China)

    2015-09-25

    Heterogeneous delays with positive lower bound (gap) are taken into consideration in Kuramoto model. On the Ott–Antonsen's manifold, the dynamical transitional behavior from incoherence to coherence is mediated by Hopf bifurcation. We establish a perturbation technique on complex domain, by which universal normal forms, stability and criticality of the Hopf bifurcation are obtained. Theoretically, a hysteresis loop is found near the subcritically bifurcated coherent state. With respect to Gamma distributed delay with fixed mean and variance, we find that the large gap decreases Hopf bifurcation value, induces supercritical bifurcations, avoids the hysteresis loop and significantly increases in the number of coexisting coherent states. The effect of gap is finally interpreted from the viewpoint of excess kurtosis of Gamma distribution. - Highlights: • Heterogeneously delay-coupled Kuramoto model with minimal delay is considered. • Perturbation technique on complex domain is established for bifurcation analysis. • Hysteresis phenomenon is investigated in a theoretical way. • The effect of excess kurtosis of distributed delays is discussed.

  9. Application of a Biodegradable Polyesteramide Derived from L-Alanine as Novel Excipient for Controlled Release Matrix Tablets.

    Science.gov (United States)

    Bonillo Martínez, Ana Dora; Galán, Inés Carmen Rodríguez; Bellver, María Victoria Margarit

    2017-11-01

    This pre-formulation study assays the capacity of the polyesteramide PADAS, poly (L-alanine-dodecanediol-L-alanine-sebacic), as an insoluble tablet excipient matrix for prolonged drug release. The flow properties of PADAS were suitable for tableting, and the compressibility of tablets containing exclusively PADAS was evaluated by ESEM observation of the microstructure. The tablets were resistant to crushing and non-friable and they did not undergo disintegration (typical features of an inert matrix). Tablets containing 33.33% sodium diclofenac (DF), ketoprofen (K) or dexketoprofen trometamol (DK-T) as a model drug, in addition with 66.67% of polymer, were formulated, and the absence of interactions between the components was confirmed by differential scanning calorimetry. Dissolution tests showed that PADAS retained DF and K and prolonged drug release, following a Higuchi kinetic. The tablets containing DK-T did not retain the drug sufficiently for prolonged release to be established. Tablets containing DK-T and 66.67, 83.33 or 91.67% PADAS, compressed at 44.48 or 88.96 kN, were elaborated to determine the influence of the polymer amount and of the compression force on DK-T release. Both parameters significantly delayed drug release, except when the proportion of polymer was 91.67%.

  10. Bubbling in delay-coupled lasers.

    Science.gov (United States)

    Flunkert, V; D'Huys, O; Danckaert, J; Fischer, I; Schöll, E

    2009-06-01

    We theoretically study chaos synchronization of two lasers which are delay coupled via an active or a passive relay. While the lasers are synchronized, their dynamics is identical to a single laser with delayed feedback for a passive relay and identical to two delay-coupled lasers for an active relay. Depending on the coupling parameters the system exhibits bubbling, i.e., noise-induced desynchronization, or on-off intermittency. We associate the desynchronization dynamics in the coherence collapse and low-frequency fluctuation regimes with the transverse instability of some of the compound cavity's antimodes. Finally, we demonstrate how, by using an active relay, bubbling can be suppressed.

  11. [Technological and pharmacotherapeutic properties of selected drugs with modified release of diclofenac sodium].

    Science.gov (United States)

    Kołodziejczyk, Michał Krzysztof; Kołodziejska, Justyna; Zgoda, Marian Mikołaj

    2012-01-01

    Diclofenac and its sodium salt is one of the best-known and popular therapeutic agents from the group of NSAIDs used in medicine in many various pharmaceutical forms. Therapeutic products containing diclofenac sodium salt in doses of 100 mg and 75 mg with a qualitatively and quantitatively diversified share of excipients and a variable dosage form of the drug (solid capsules, tablets with modified release) were subjected to technological and pharmaceutical analysis. The effect of solid formulation components of polymer character making the core and the coating of the pharmaceutical form of therapeutic products on the disintegration time and pharmaceutical availability in pharmacopoeial receptor fluids was estimated. Market therapeutic products with diclofenac sodium in doses of 75 mg and 100 mg, technological analysis of the drug dosage form was conducted, disintegration time of solid oral dosage forms of the drug with diclofenac sodium salt was examined and research on pharmaceutical availability of diclofenac sodium salt from tested therapeutic products was conducted using the acid phase and the buffer phase according to the FP standards for delayed release enteral dosage forms. The experimental data was supplemented with the statistical analysis. There are three formulations in the form of solid capsules and one formulation in the form of a coated tablet. All therapeutic products bear features of a dosage form of modified release of diclofenac sodium salt, frequently of a delayed release formula in the duodenum or the small intestine with regard to the limitation of typical undesirable effects after taking NSAIDs. Considerable diversity between solid capsules and the tablet with modified release during disintegration or hydration and swelling has been observed. In the environment of a receptor fluid--purified water (pH = 7) the capsule Dicloberl retard disintegrates at the fastest rate in 5,49 minutes, and then in the order: DicloDuo 75 mg--8,13 minutes and

  12. New Delay-Dependent Stability Criteria for Uncertain Neutral Systems with Mixed Time-Varying Delays and Nonlinear Perturbations

    Directory of Open Access Journals (Sweden)

    Hamid Reza Karimi

    2009-01-01

    Full Text Available The problem of stability analysis for a class of neutral systems with mixed time-varying neutral, discrete and distributed delays and nonlinear parameter perturbations is addressed. By introducing a novel Lyapunov-Krasovskii functional and combining the descriptor model transformation, the Leibniz-Newton formula, some free-weighting matrices, and a suitable change of variables, new sufficient conditions are established for the stability of the considered system, which are neutral-delay-dependent, discrete-delay-range-dependent, and distributed-delay-dependent. The conditions are presented in terms of linear matrix inequalities (LMIs and can be efficiently solved using convex programming techniques. Two numerical examples are given to illustrate the efficiency of the proposed method.

  13. Delay Management with Re-Routing of Passengers

    NARCIS (Netherlands)

    T.A.B. Dollevoet (Twan); D. Huisman (Dennis); M.E. Schmidt (Marie); A. Schöbel (Anita)

    2010-01-01

    textabstractThe question of delay management is whether trains should wait for a delayed feeder train or should depart on time. In classical delay management models passengers always take their originally planned route. In this paper, we propose a model where re-routing of passengers is

  14. Synchronization analysis of coloured delayed networks under ...

    Indian Academy of Sciences (India)

    This paper investigates synchronization of coloured delayed networks under decentralized pinning intermittent control. To begin with, the time delays are taken into account in the coloured networks. In addition, we propose a decentralized pinning intermittent control for coloured delayed networks, which is different from that ...

  15. Time-Delay Effects on Constitutive Gene Expression*

    International Nuclear Information System (INIS)

    Feng Yan-Ling; Wang Dan; Tang Xu-Lei; Dong Jian-Min

    2017-01-01

    The dynamics of constitutive gene expression with delayed mRNA degradation is investigated, where the intrinsic noise caused by the small number of reactant molecules is introduced. It is found that the oscillatory behavior claimed in previous investigations does not appear in the approximation of small time delay, and the steady state distribution still follows the Poisson law. Furthermore, we introduce the extrinsic noise induced by surrounding environment to explore the effects of this noise and time delay on the Fano factor. Based on a delay Langevin equation and the corresponding Fokker–Planck equation, the distribution of mRNA copy-number is achieved analytically. The time delay and extrinsic noise play similar roles in the gene expression system, that is, they are able to result in the deviation of the Fano factor from 1 evidently. The measured Fano factor for constitutive gene expression is slightly larger than 1, which is perhaps attributed to the time-delay effect. (paper)

  16. Delay-Dependent Asymptotic Stability of Cohen-Grossberg Models with Multiple Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Xiaofeng Liao

    2007-01-01

    Full Text Available Dynamical behavior of a class of Cohen-Grossberg models with multiple time-varying delays is studied in detail. Sufficient delay-dependent criteria to ensure local and global asymptotic stabilities of the equilibrium of this network are derived by constructing suitable Lyapunov functionals. The obtained conditions are shown to be less conservative and restrictive than those reported in the known literature. Some numerical examples are included to demonstrate our results.

  17. Quad precision delay generator

    International Nuclear Information System (INIS)

    Krishnan, Shanti; Gopalakrishnan, K.R.; Marballi, K.R.

    1997-01-01

    A Quad Precision Delay Generator delays a digital edge by a programmed amount of time, varying from nanoseconds to microseconds. The output of this generator has an amplitude of the order of tens of volts and rise time of the order of nanoseconds. This was specifically designed and developed to meet the stringent requirements of the plasma focus experiments. Plasma focus is a laboratory device for producing and studying nuclear fusion reactions in hot deuterium plasma. 3 figs

  18. VEGF(165) and bFGF protein-based therapy in a slow release system to improve angiogenesis in a bioartificial dermal substitute in vitro and in vivo

    NARCIS (Netherlands)

    Wilcke, I.; Lohmeyer, J. A.; Liu, S.; Condurache, A.; Krueger, S.; Mailaender, P.; Machens, H. G.

    Background Angiogenesis can be enhanced by several growth factors, like vascular endothelial growth factor-165 (VEGF(165)) and basic fibroblast growth factor (bFGF). Delayed release of such growth factors could be provided by incorporation of growth factors in fibrin matrices. In this study, we

  19. 14 CFR 1214.805 - Unforeseen customer delay.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Unforeseen customer delay. 1214.805 Section... for Spacelab Services § 1214.805 Unforeseen customer delay. Should an unforeseen customer payload..., if requested by the customer, make all reasonable efforts to prevent a delay, contingent on the...

  20. Using random event simulation to evaluate the effectiveness of indoor sheltering during a sour gas release

    International Nuclear Information System (INIS)

    Wilson, D.

    2003-01-01

    In the event of sour gas releases to the atmosphere, there is a strong bias toward evacuation rather than sheltering-in-place. This paper described the critical factors in decision-making for shelter-in-place versus evacuation. These include: delay time expected before release begins; size of potential release, explosion or fire; expected duration; direction to safety for evacuation; the air tightness of the building; and, the number of people in the emergency response zone. A shelter-in-place decision chart developed by the Canadian Association of Fire Chiefs was presented. It shows the usual bias toward evacuation as the default position. It also shows the greatest drawbacks of sheltering-in-place. The main factor in maintaining the effectiveness of the building shelter is the rate of air infiltration into the building. Other issues to consider include: reactive versus passive chemicals in the release; light versus heavy gas releases; building type (houses, high-rise apartments, office buildings, or warehouses); tightness of building construction; whether to turn the house heating and air conditioning on or off during shelter; daytime versus nighttime conditions; and, cost factors. Equations for calculating indoor and outdoor toxic exposure to decide on shelter versus evacuation were also presented. It was concluded that the absence of peak concentrations dramatically reduce the risk of fatality to people sheltering indoors. Keeping people indoors is the best way to assure their safety for the first hour following a toxic release. 8 refs., 6 figs

  1. Magnetic pulse sharpener and delay-line

    International Nuclear Information System (INIS)

    Li Jin; Dai Guangsen; Xia Liansheng

    2002-01-01

    This paper describes a method to achieve short rise time pulse which has been delayed with a delay-line and magnetic pulse sharpener. A delay-line and two shock-lines are designed to carry pulsed signal with a maximum voltage magnitude up to 80 kV. A pulse of High voltage with arise time of 48 ns at a level of 0.1%-0.9% were achieved, and the attenuation in the line is very small

  2. Eye movements in interception with delayed visual feedback.

    Science.gov (United States)

    Cámara, Clara; de la Malla, Cristina; López-Moliner, Joan; Brenner, Eli

    2018-04-19

    The increased reliance on electronic devices such as smartphones in our everyday life exposes us to various delays between our actions and their consequences. Whereas it is known that people can adapt to such delays, the mechanisms underlying such adaptation remain unclear. To better understand these mechanisms, the current study explored the role of eye movements in interception with delayed visual feedback. In two experiments, eye movements were recorded as participants tried to intercept a moving target with their unseen finger while receiving delayed visual feedback about their own movement. In Experiment 1, the target randomly moved in one of two different directions at one of two different velocities. The delay between the participant's finger movement and movement of the cursor that provided feedback about the finger movements was gradually increased. Despite the delay, participants followed the target with their gaze. They were quite successful at hitting the target with the cursor. Thus, they moved their finger to a position that was ahead of where they were looking. Removing the feedback showed that participants had adapted to the delay. In Experiment 2, the target always moved in the same direction and at the same velocity, while the cursor's delay varied across trials. Participants still always directed their gaze at the target. They adjusted their movement to the delay on each trial, often succeeding to intercept the target with the cursor. Since their gaze was always directed at the target, and they could not know the delay until the cursor started moving, participants must have been using peripheral vision of the delayed cursor to guide it to the target. Thus, people deal with delays by directing their gaze at the target and using both experience from previous trials (Experiment 1) and peripheral visual information (Experiment 2) to guide their finger in a way that will make the cursor hit the target.

  3. The dynamics of second-order equations with delayed feedback and a large coefficient of delayed control

    Science.gov (United States)

    Kashchenko, Sergey A.

    2016-12-01

    The dynamics of second-order equations with nonlinear delayed feedback and a large coefficient of a delayed equation is investigated using asymptotic methods. Based on special methods of quasi-normal forms, a new construction is elaborated for obtaining the main terms of asymptotic expansions of asymptotic residual solutions. It is shown that the dynamical properties of the above equations are determined mostly by the behavior of the solutions of some special families of parabolic boundary value problems. A comparative analysis of the dynamics of equations with the delayed feedback of three types is carried out.

  4. Time-delayed chameleon: Analysis, synchronization and FPGA implementation

    Science.gov (United States)

    Rajagopal, Karthikeyan; Jafari, Sajad; Laarem, Guessas

    2017-12-01

    In this paper we report a time-delayed chameleon-like chaotic system which can belong to different families of chaotic attractors depending on the choices of parameters. Such a characteristic of self-excited and hidden chaotic flows in a simple 3D system with time delay has not been reported earlier. Dynamic analysis of the proposed time-delayed systems are analysed in time-delay space and parameter space. A novel adaptive modified functional projective lag synchronization algorithm is derived for synchronizing identical time-delayed chameleon systems with uncertain parameters. The proposed time-delayed systems and the synchronization algorithm with controllers and parameter estimates are then implemented in FPGA using hardware-software co-simulation and the results are presented.

  5. Bifurcation analysis of delay-induced periodic oscillations

    NARCIS (Netherlands)

    Green, K.

    2010-01-01

    In this paper we consider a generic differential equation with a cubic nonlinearity and delay. This system, in the absence of delay, is known to undergo an oscillatory instability. The addition of the delay is shown to result in the creation of a number of periodic solutions with constant amplitude

  6. Improved Delayed-Neutron Spectroscopy Using Trapped Ions

    Energy Technology Data Exchange (ETDEWEB)

    Norman, Eric

    2018-04-24

    The neutrons emitted following the  decay of fission fragments (known as delayed neutrons because they are emitted after fission on a timescale of the -decay half-lives) play a crucial role in reactor performance and control. Reviews of delayed-neutron properties highlight the need for high-quality data for a wide variety of delayed-neutron emitters to better understand the timedependence and energy spectrum of the neutrons as these properties are essential for a detailed understanding of reactor kinetics needed for reactor safety and to understand the behavior of these reactors under various accident and component-failure scenarios. For fast breeder reactors, criticality calculations require accurate delayed-neutron energy spectra and approximations that are acceptable for light-water reactors such as assuming the delayed-neutron and fission-neutron energy spectra are identical are not acceptable and improved -delayed neutron data is needed for safety and accident analyses for these reactors. With improved nuclear data, the delayedneutrons flux and energy spectrum could be calculated from the contributions from individual isotopes and therefore could be accurately modeled for any fuel-cycle concept, actinide mix, or irradiation history. High-quality -delayed neutron measurements are also critical to constrain modern nuclear-structure calculations and empirical models that predict the decay properties for nuclei for which no data exists and improve the accuracy and flexibility of the existing empirical descriptions of delayed neutrons from fission such as the six-group representation

  7. Not All Types of Delay Are Equal: Postsecondary Delay in the U.S. and Taking a Gap Year

    Science.gov (United States)

    Hoe, Nina DePena

    2014-01-01

    Postsecondary delay in the U.S. is a topic that has generated interest in the field of higher education in recent decades. Seventeen percent of U.S. students under the age of 24 who began their postsecondary education in 2004 delayed their entrance for some period of time. At the national level, studies have indicated that students who delay are…

  8. Decade-long time delays in nutrient and plant species dynamics during eutrophication and re-oligotrophication of Lake Fure 1900–2015

    DEFF Research Database (Denmark)

    Sand-Jensen, Kaj; Bruun, Hans Henrik; Båstrup-Spohr, Lars

    2017-01-01

    Fure, Denmark, spanning the transformation from pristine environmental conditions in the early 1900s through a period (1920–1970) of eutrophication – from accelerating sewage input of phosphorus (P) – and subsequent re-oligotrophication after sewage cleaning (1970–2015). We examine time delays between...... sediment release. Fifty years of eutrophication led to a reduction in aquatic macrophyte richness from 36 species to 12. Species’ responses were closely related to their growth strategy and depth distribution. Deep-growing mosses, charophytes and short angiosperms disappeared, while tall angiosperms...... in species dominance takes longer than colonization by new species. Synthesis. Time delays of P concentrations, water clarity and macrophyte richness and composition were long and complex. Neglecting growth strategies of species makes application of extinction debt and colonization credit concepts dubious...

  9. Time-Delay System Identification Using Genetic Algorithm

    DEFF Research Database (Denmark)

    Yang, Zhenyu; Seested, Glen Thane

    2013-01-01

    Due to the unknown dead-time coefficient, the time-delay system identification turns to be a non-convex optimization problem. This paper investigates the identification of a simple time-delay system, named First-Order-Plus-Dead-Time (FOPDT), by using the Genetic Algorithm (GA) technique. The qual......Due to the unknown dead-time coefficient, the time-delay system identification turns to be a non-convex optimization problem. This paper investigates the identification of a simple time-delay system, named First-Order-Plus-Dead-Time (FOPDT), by using the Genetic Algorithm (GA) technique...

  10. Neutron stochastic transport theory with delayed neutrons

    International Nuclear Information System (INIS)

    Munoz-Cobo, J.L.; Verdu, G.

    1987-01-01

    From the stochastic transport theory with delayed neutrons, the Boltzmann transport equation with delayed neutrons for the average flux emerges in a natural way without recourse to any approximation. From this theory a general expression is obtained for the Feynman Y-function when delayed neutrons are included. The single mode approximation for the particular case of a subcritical assembly is developed, and it is shown that Y-function reduces to the familiar expression quoted in many books, when delayed neutrons are not considered, and spatial and source effects are not included. (author)

  11. Developmental delay

    Science.gov (United States)

    Nutrition support is essential for the care of the child with developmental delay. After a thorough evaluation, an individualized intervention plan that accounts for the child’s nutrition status, feeding ability, and medical condition may be determined. Nutrition assessments may be performed at leas...

  12. Controlling the heat release in HCCI combustion of DME with methanol and EGR

    DEFF Research Database (Denmark)

    Pedersen, Troels Dyhr; Schramm, Jesper; Yanai, Tadanori

    2010-01-01

    quantity required was determined. The added methanol increased the BMEP by increasing the total heat release and retarding the combustion to after TDC. Engine knock was reduced with increasing quantities of methanol. The highest BMEP was achieved when the equivalence ratio of methanol was around 0.......12 at 1000 RPM, and around 0.76 at 1800 RPM. EGR was also used to retarding the timing. With a moderate amount of EGR the effect on the combustion was not notable, but as the equivalence ratio approached unity the combustion was increasingly delayed and the rate of reaction reduced. Engine knock seized...

  13. The effective delayed neutron fraction for bare-metal criticals

    International Nuclear Information System (INIS)

    Pearlstein, S.

    1999-01-01

    Given sufficient material, a large number of actinides could be used to form bare-metal criticals. The effective delayed neutron fraction for a bare critical comprised of a fissile material is comparable with the absolute delayed neutron fraction. The effective delayed neutron fraction for a bare critical composed of a fissionable material is reduced by factors of 2 to 10 when compared with the absolute delayed neutron fraction. When the effective delayed neutron fraction is small, the difference between delayed and prompt criticality is small, and extreme caution must be used in critical assemblies of these materials. This study uses an approximate but realistic model to survey the actinide region to compare effective delayed neutron fractions with absolute delayed neutron fractions

  14. Recent activities for β-decay half-lives and β-delayed neutron emission of very neutron-rich isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Dillmann, Iris [TRIUMF, Vancouver BC, V6T 2A3, Canada and GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Abriola, Daniel [Laboratorio Tandar, Comisión Nacional de Energía Atómica, B1650KINA, San Martín, Buenos Aires (Argentina); Singh, Balraj [Department of Physics and Astronomy, McMaster University, Hamilton ON, L8S 4M1 (Canada)

    2014-05-02

    Beta-delayed neutron (βn) emitters play an important, two-fold role in the stellar nucleosynthesis of heavy elements in the 'rapid neutron-capture process' (r process). On one hand they lead to a detour of the material β-decaying back to stability. On the other hand, the released neutrons increase the neutron-to-seed ratio, and are re-captured during the freeze-out phase and thus influence the final solar r-abundance curve. A large fraction of the isotopes inside the r-process reaction path are not yet experimentally accessible and are located in the (experimental) 'Terra Incognita'. With the next generation of fragmentation and ISOL facilities presently being built or already in operation, one of the main motivation of all projects is the investigation of these very neutron-rich isotopes. A short overview of one of the planned programs to measure βn-emitters at the limits of the presently know isotopes, the BRIKEN campaign (Beta delayed neutron emission measurements at RIKEN) will be given. Presently, about 600 β-delayed one-neutron emitters are accessible, but only for a third of them experimental data are available. Reaching more neutron-rich isotopes means also that multiple neutron-emission becomes the dominant decay mechanism. About 460 β-delayed two-, three-or four-neutron emitters are identified up to now but for only 30 of them experimental data about the neutron branching ratios are available, most of them in the light mass region below A=30. The International Atomic and Energy Agency (IAEA) has identified the urgency and picked up this topic recently in a 'Coordinated Research Project' on a 'Reference Database for Beta-Delayed Neutron Emission Data'. This project will review, compile, and evaluate the existing data for neutron-branching ratios and half-lives of β-delayed neutron emitters and help to ensure a reliable database for the future discoveries of new isotopes and help to constrain astrophysical and

  15. Discrete-time BAM neural networks with variable delays

    Science.gov (United States)

    Liu, Xin-Ge; Tang, Mei-Lan; Martin, Ralph; Liu, Xin-Bi

    2007-07-01

    This Letter deals with the global exponential stability of discrete-time bidirectional associative memory (BAM) neural networks with variable delays. Using a Lyapunov functional, and linear matrix inequality techniques (LMI), we derive a new delay-dependent exponential stability criterion for BAM neural networks with variable delays. As this criterion has no extra constraints on the variable delay functions, it can be applied to quite general BAM neural networks with a broad range of time delay functions. It is also easy to use in practice. An example is provided to illustrate the theoretical development.

  16. Discrete-time BAM neural networks with variable delays

    International Nuclear Information System (INIS)

    Liu Xinge; Tang Meilan; Martin, Ralph; Liu Xinbi

    2007-01-01

    This Letter deals with the global exponential stability of discrete-time bidirectional associative memory (BAM) neural networks with variable delays. Using a Lyapunov functional, and linear matrix inequality techniques (LMI), we derive a new delay-dependent exponential stability criterion for BAM neural networks with variable delays. As this criterion has no extra constraints on the variable delay functions, it can be applied to quite general BAM neural networks with a broad range of time delay functions. It is also easy to use in practice. An example is provided to illustrate the theoretical development

  17. Influence of ionic complexation on release rate profiles from multiple water-in-oil-in-water (W/O/W) emulsions.

    Science.gov (United States)

    Bonnet, Marie; Cansell, Maud; Placin, Frédéric; David-Briand, Elisabeth; Anton, Marc; Leal-Calderon, Fernando

    2010-07-14

    Water-in-oil-in-water (W/O/W) double emulsions were prepared, and the kinetics of release of magnesium ions from the internal to the external water phase was followed. Different chelating agents (phosvitin and gluconate) were used to bind magnesium within the prospect of improving the ion retention in the internal aqueous droplets. Magnesium release was monitored for 1 month of storage, for each formulation, with and without chelation, at two storage temperatures (4 and 25 degrees C). Leakage occurred without film rupturing (coalescence) and was mainly due to entropically driven diffusion/permeation phenomena. The experimental results revealed a clear correlation between the effectiveness of chelating agents to delay the delivery and their binding capacity characterized by the equilibrium affinity constant. The kinetic data (percent released versus time curves) were interpreted within the framework of a kinetic model based on diffusion and taking into account magnesium chelation.

  18. [Effect of UV-B radiation on release of nitrogen and phosphorus from leaf litter in subtropical region in China].

    Science.gov (United States)

    Song, Xin-Zhang; Zhang, Hui-Ling; Jiang, Hong; Yu, Shu-Quan

    2012-02-01

    The release of nitrogen and phosphorus from leaf litter of six representative species, Cunninghamia lanceolata, Pinus massoniana, Schima superba, Cinnamanun camphora, Cyclobalanopsis glauca and Castanopsis eyeri, was investigated with litterbag method under ambient and reduced UV-B radiation (22.1% below ambient) treatments in subtropical region. The results showed that, the N dynamics exhibited three patterns: immobilization, mineralization-immobilization and mineralization-immobilization-mineralization. P dynamics also exhibited three different patterns: mineralization, immobilization-mineralization-immobilization and no large change. Compared with ambient treatment, the reduced treatment significantly delayed the N release from C. eyeri and P release from both C. glanca and C. eyeri (Plitter decomposition. The C: P ratios can partly explain the P dynamics during decomposition. The more works need to be done to better understand the role of UV-B radiation in the forest ecosystem in humid subtropical China under global environment change.

  19. Delayed Auditory Feedback and Movement

    Science.gov (United States)

    Pfordresher, Peter Q.; Dalla Bella, Simone

    2011-01-01

    It is well known that timing of rhythm production is disrupted by delayed auditory feedback (DAF), and that disruption varies with delay length. We tested the hypothesis that disruption depends on the state of the movement trajectory at the onset of DAF. Participants tapped isochronous rhythms at a rate specified by a metronome while hearing DAF…

  20. Assessing the efficiency of Wolbachia driven Aedes mosquito suppression by delay differential equations.

    Science.gov (United States)

    Huang, Mugen; Luo, Jiaowan; Hu, Linchao; Zheng, Bo; Yu, Jianshe

    2017-12-14

    To suppress wild population of Aedes mosquitoes, the primary transmission vector of life-threatening diseases such as dengue, malaria, and Zika, an innovative strategy is to release male mosquitoes carrying the bacterium Wolbachia into natural areas to drive female sterility by cytoplasmic incompatibility. We develop a model of delay differential equations, incorporating the strong density restriction in the larval stage, to assess the delicate impact of life table parameters on suppression efficiency. Through mathematical analysis, we find the sufficient and necessary condition for global stability of the complete suppression state. This condition, combined with the experimental data for Aedes albopictus population in Guangzhou, helps us predict a large range of releasing intensities for suppression success. In particular, we find that if the number of released infected males is no less than four times the number of mosquitoes in wild areas, then the mosquito density in the peak season can be reduced by 95%. We introduce an index to quantify the dependence of suppression efficiency on parameters. The invariance of some quantitative properties of the index values under various perturbations of the same parameter justifies the applicability of this index, and the robustness of our modeling approach. The index yields a ranking of the sensitivity of all parameters, among which the adult mortality has the highest sensitivity and is considerably more sensitive than the natural larvae mortality. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Impact of salt form and molecular weight of chitosan on swelling and drug release from chitosan matrix tablets.

    Science.gov (United States)

    Huanbutta, Kampanart; Cheewatanakornkool, Kamonrak; Terada, Katsuhide; Nunthanid, Jurairat; Sriamornsak, Pornsak

    2013-08-14

    Magnetic resonance imaging (MRI) and gravimetric techniques were used to assess swelling and erosion behaviors of hydrophilic matrix tablets made of chitosan. The impact of salt form, molecular weight (MW) and dissolution medium on swelling behavior and drug (theophylline) release was studied. The matrix tablets made of chitosan glycolate (CGY) showed the greatest swelling in both acid and neutral media, compared to chitosan aspartate, chitosan glutamate and chitosan lactate. MRI illustrated that swelling region of CGY in both media was not different in the first 100 min but glassy region (dry core) in 0.1N HCl was less than in pH 6.8 buffer. The tablets prepared from chitosan with high MW swelled greater than those of low MW. Moreover, CGY can delay drug release in the acid condition due to thick swollen gel and low erosion rate. Therefore, CGY may be suitably applied as sustained drug release polymer or enteric coating material. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Delayed feedback control of fractional-order chaotic systems

    International Nuclear Information System (INIS)

    Gjurchinovski, A; Urumov, V; Sandev, T

    2010-01-01

    We study the possibility to stabilize unstable steady states and unstable periodic orbits in chaotic fractional-order dynamical systems by the time-delayed feedback method. By performing a linear stability analysis, we establish the parameter ranges for successful stabilization of unstable equilibria in the plane parameterized by the feedback gain and the time delay. An insight into the control mechanism is gained by analyzing the characteristic equation of the controlled system, showing that the control scheme fails to control unstable equilibria having an odd number of positive real eigenvalues. We demonstrate that the method can also stabilize unstable periodic orbits for a suitable choice of the feedback gain, providing that the time delay is chosen to coincide with the period of the target orbit. In addition, it is shown numerically that delayed feedback control with a sinusoidally modulated time delay significantly enlarges the stability region of steady states in comparison to the classical time-delayed feedback scheme with a constant delay.

  3. Sustained-release progesterone vaginal suppositories 1--development of sustained-release granule--.

    Science.gov (United States)

    Nakayama, Ayako; Sunada, Hisakazu; Okamoto, Hirokazu; Furuhashi, Kaoru; Ohno, Yukiko; Ito, Mikio

    2009-02-01

    Progesterone (P) is an important hormone for the establishment of pregnancy, and its administration is useful for luteal insufficiency. Considering the problems of commercially available oral and injection drugs, hospital-formulated vaginal suppositories are clinically used. However, since the half-life of P suppositories is short, it is difficult to maintain its constant blood concentration. To sustain drug efficacy and prevent side-effects, we are attempting to develop sustained-release suppositories by examining the degree of sustained-release of active ingredients. In this study, we examined the combinations of granulation methods and release systems for the preparation of sustained-release granules of P, and produced 13 types of sustained-release granules. We also examined the diameter, content, and dissolution of each type of granules, and confirmed that the sustained-release of all types of granules was satisfactory. Among the sustained-release granules, we selected granules with a content and a degree of sustained-release suitable for sustained-release suppositories.

  4. Stability of formation control using a consensus protocol under directed communications with two time delays and delay scheduling

    Science.gov (United States)

    Cepeda-Gomez, Rudy; Olgac, Nejat

    2016-01-01

    We consider a linear algorithm to achieve formation control in a group of agents which are driven by second-order dynamics and affected by two rationally independent delays. One of the delays is in the position and the other in the velocity information channels. These delays are taken as constant and uniform throughout the system. The communication topology is assumed to be directed and fixed. The formation is attained by adding a supplementary control term to the stabilising consensus protocol. In preparation for the formation control logic, we first study the stability of the consensus, using the recent cluster treatment of characteristic roots (CTCR) paradigm. This effort results in a unique depiction of the non-conservative stability boundaries in the domain of the delays. However, CTCR requires the knowledge of the potential stability switching loci exhaustively within this domain. The creation of these loci is done in a new surrogate coordinate system, called the 'spectral delay space (SDS)'. The relative stability is also investigated, which has to do with the speed of reaching consensus. This step leads to a paradoxical control design concept, called the 'delay scheduling', which highlights the fact that the group behaviour may be enhanced by increasing the delays. These steps lead to a control strategy to establish a desired group formation that guarantees spacing among the agents. Example case studies are presented to validate the underlying analytical derivations.

  5. Brain Structure Linking Delay Discounting and Academic Performance.

    Science.gov (United States)

    Wang, Song; Kong, Feng; Zhou, Ming; Chen, Taolin; Yang, Xun; Chen, Guangxiang; Gong, Qiyong

    2017-08-01

    As a component of self-discipline, delay discounting refers to the ability to wait longer for preferred rewards and plays a pivotal role in shaping students' academic performance. However, the neural basis of the association between delay discounting and academic performance remains largely unknown. Here, we examined the neuroanatomical substrates underlying delay discounting and academic performance in 214 adolescents via voxel-based morphometry (VBM) by performing structural magnetic resonance imaging (S-MRI). Behaviorally, we confirmed the significant correlation between delay discounting and academic performance. Neurally, whole-brain regression analyses indicated that regional gray matter volume (rGMV) of the left dorsolateral prefrontal cortex (DLPFC) was associated with both delay discounting and academic performance. Furthermore, delay discounting partly accounted for the association between academic performance and brain structure. Differences in the rGMV of the left DLPFC related to academic performance explained over one-third of the impact of delay discounting on academic performance. Overall, these results provide the first evidence for the common neural basis linking delay discounting and academic performance. Hum Brain Mapp 38:3917-3926, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  6. Transcriptional delay stabilizes bistable gene networks.

    Science.gov (United States)

    Gupta, Chinmaya; López, José Manuel; Ott, William; Josić, Krešimir; Bennett, Matthew R

    2013-08-02

    Transcriptional delay can significantly impact the dynamics of gene networks. Here we examine how such delay affects bistable systems. We investigate several stochastic models of bistable gene networks and find that increasing delay dramatically increases the mean residence times near stable states. To explain this, we introduce a non-Markovian, analytically tractable reduced model. The model shows that stabilization is the consequence of an increased number of failed transitions between stable states. Each of the bistable systems that we simulate behaves in this manner.

  7. Improved Criteria on Delay-Dependent Stability for Discrete-Time Neural Networks with Interval Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    O. M. Kwon

    2012-01-01

    Full Text Available The purpose of this paper is to investigate the delay-dependent stability analysis for discrete-time neural networks with interval time-varying delays. Based on Lyapunov method, improved delay-dependent criteria for the stability of the networks are derived in terms of linear matrix inequalities (LMIs by constructing a suitable Lyapunov-Krasovskii functional and utilizing reciprocally convex approach. Also, a new activation condition which has not been considered in the literature is proposed and utilized for derivation of stability criteria. Two numerical examples are given to illustrate the effectiveness of the proposed method.

  8. Physico-chemical state influences in vitro release profile of curcumin from pectin beads.

    Science.gov (United States)

    Nguyen, An Thi-Binh; Winckler, Pascale; Loison, Pauline; Wache, Yves; Chambin, Odile

    2014-09-01

    Curcumin is a polyphenolic compound with diverse effects interesting to develop health benefit products but its formulation in functional foods or in food supplement is hampered by its poor water solubility and susceptibility to alkaline conditions, light, oxidation and heat. Encapsulation of curcumin could be a mean to overcome these difficulties. In this paper, curcumin was encapsulated by ionotropic gelation method in low methoxyl pectin beads associated with different surfactants: Solutol(®), Transcutol(®) and sodium caseinate. After encapsulation, physico-chemical properties of encapsulated curcumin such as its solubility, physical state, tautomeric forms and encapsulation efficiency as well as encapsulation yield were characterized. In vitro dissolution of curcumin from beads displayed different kinetic profiles according to bead composition due to different matrix network. As Solutol(®) was a good solvent for curcumin, the drug was present into amorphous form in these beads inducing a rapid release of curcumin in the simulated digestive fluids. In contrast, drug release was slower from sodium caseinate beads since curcumin was not totally dissolved during the manufacturing process. Moreover, the FLIM studies showed that a part of curcumin was encapsulated in caseinate micelles and that 34% of this drug was in keto form which may delay the curcumin release. The Transcutol beads showed also a slow drug release because of the low curcumin solubility and the high density of the matrix. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Dynamics of microbubble oscillators with delay coupling

    Science.gov (United States)

    Heckman, C. R.; Sah, S. M.; Rand, R. H.

    2010-10-01

    We investigate the stability of the in-phase mode in a system of two delay-coupled bubble oscillators. The bubble oscillator model is based on a 1956 paper by Keller and Kolodner. Delay coupling is due to the time it takes for a signal to travel from one bubble to another through the liquid medium that surrounds them. Using techniques from the theory of differential-delay equations as well as perturbation theory, we show that the equilibrium of the in-phase mode can be made unstable if the delay is long enough and if the coupling strength is large enough, resulting in a Hopf bifurcation. We then employ Lindstedt's method to compute the amplitude of the limit cycle as a function of the time delay. This work is motivated by medical applications involving noninvasive localized drug delivery via microbubbles.

  10. Exploring delay causes of road construction projects in

    Directory of Open Access Journals (Sweden)

    Remon F. Aziz

    2016-06-01

    Full Text Available Construction delays are a common phenomenon in civil engineering projects in Egypt including road construction projects. Therefore, it is essential to study and analyze causes of road construction delays. This paper studied a list of construction delay causes gathered from literature having different types of construction, different countries, different periods and different numbers of delay causes and delay groups. A questionnaire and personal interviews have formed the basis of this paper listing 293 delay causes. The questionnaire survey was distributed to 500 construction participants and 389 were received who represent consultants, contractors and site/design engineers excluding the owner representing the government in road projects as one party only. Relative Importance Index (RII is calculated and according to the highest values the top twenty and the least twenty delay causes of construction projects in Egypt are determined. A case study is analyzed and compared to the most important delay causes in the paper. The test results reveal good correlation of causes and groups between contractors and site/design engineers and between consultants and site design engineers and a somewhat low correlation between contractors and consultants. So there are no root causes that can be taking for granted to be most or least effective delay causes. Proposed model for predicting actual road construction project duration was developed; a real case study tested the accuracy of proposed model. According to the analysis of case study, the most contributing causes and groups to delays were discussed, and some future recommendations were proposed in order to control and minimize delays in road construction projects. These findings can be helpful for project managers to mitigate the road construction delays in Egypt. In order to effectively overcome the road construction delays in developing countries, suggestions are made for fundamental and large

  11. A new car-following model with two delays

    International Nuclear Information System (INIS)

    Yu, Lei; Shi, Zhong-ke; Li, Tong

    2014-01-01

    A new car-following model is proposed by taking into account two different time delays in sensing headway and velocity. The effect of time delays on the stability analysis is studied. The theoretical and numerical results show that traffic jams are suppressed efficiently when the difference between two time delays decreases and those can be described by the solution of the modified Korteweg–de Vries (mKdV) equation. Traffic flow is more stable with two delays in headway and velocity than in the case with only one delay in headway. The impact of local small disturbance to the system is also studied.

  12. Delayed Partial Nephrectomy for Hydronephrosis After Renal Trauma.

    Science.gov (United States)

    Setia, Shaan; Jackson, Jessica Nicole; Herndon, C D Anthony; Corbett, Sean T

    2017-03-01

    Delayed sequelae following conservative management of renal trauma in the pediatric population are uncommon. Reports of delayed operations to manage these sequelae are even less common. Here we present the case of a 16-year-old male patient who had delayed development of upper urinary tract obstruction with recurrent infections following high-grade renal trauma managed conservatively. Ultimately, he required a robotic-assisted partial nephrectomy 2 years after initial nonoperative management. This is unique as no prior studies to our knowledge have described delayed hydronephrosis and delayed partial nephrectomy over a year following renal trauma. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Microscopic Control Delay Modeling at Signalized Arterials Using Bluetooth Technology

    OpenAIRE

    Rajasekhar, Lakshmi

    2011-01-01

    Real-time control delay estimation is an important performance measure for any intersection to improve the signal timing plans dynamically in real-time and hence improve the overall system performance. Control delay estimates helps to determine the level-of-service (LOS) characteristics of various approaches at an intersection and takes into account deceleration delay, stopped delay and acceleration delay. All kinds of traffic delay calculation especially control delay calculation has always ...

  14. Role of delay-based reward in the spatial cooperation

    Science.gov (United States)

    Wang, Xu-Wen; Nie, Sen; Jiang, Luo-Luo; Wang, Bing-Hong; Chen, Shi-Ming

    2017-01-01

    Strategy selection in games, a typical decision making, usually brings noticeable reward for players which have discounted value if the delay appears. The discounted value is measure: earning sooner with a small reward or later with a delayed larger reward. Here, we investigate effects of delayed rewards on the cooperation in structured population. It is found that delayed reward supports the spreading of cooperation in square lattice, small-world and random networks. In particular, intermediate reward differences between delays impel the highest cooperation level. Interestingly, cooperative individuals with the same delay time steps form clusters to resist the invasion of defects, and cooperative individuals with lowest delay reward survive because they form the largest clusters in the lattice.

  15. Time-delayed feedback control of diffusion in random walkers

    Science.gov (United States)

    Ando, Hiroyasu; Takehara, Kohta; Kobayashi, Miki U.

    2017-07-01

    Time delay in general leads to instability in some systems, while specific feedback with delay can control fluctuated motion in nonlinear deterministic systems to a stable state. In this paper, we consider a stochastic process, i.e., a random walk, and observe its diffusion phenomenon with time-delayed feedback. As a result, the diffusion coefficient decreases with increasing delay time. We analytically illustrate this suppression of diffusion by using stochastic delay differential equations and justify the feasibility of this suppression by applying time-delayed feedback to a molecular dynamics model.

  16. Synchronization of conference presentation sequence using delay equalization approach

    Science.gov (United States)

    Godavari, Rakesh K.; Celenk, Mehmet

    2001-11-01

    In this paper, a delay equalization approach is proposed for cohesive conference presentation with minimal screen- freezing effect. The underlying screen-freezing effect is due to varying delays in the communication channels involved in broadcasting. In turn, this poses a threat to the goal of uniform delay distribution among data packets for synchronized presentation broadcast. We wish to achieve uniformity among packet arrival times to the recipients. This objective is achieved by transforming a given input delay distribution (D) to the desired output density through a delay equalization process. Considering a general case of between packet and frame delay distributions for a given input, the desired output is obtained through a delay equalization process. In case of a specific normal delay distribution, a memory-less system g(D) is determined as an approximation to the delay equalizer such that the equalizer output O(t)equalsg[D(t)] is uniformly distributed in the allowable delay limits of (a,b) assuring the specified quality of service (QoS) parameters. The corresponding delay is added at each recipient workstation, which acts as the wait period required before it begins its designated presentation.For a zero mean normal delay density case, the equalizer transfer function can be given in a closed from solution as O(t)equalsg[D(t)[equals(b-a)]0.5+eft(-D/$RO OTR(0)))[+a, where erf(x) is the standard error function. The histogram approximation is adopted as an asymptotically delay equalization means for general cases. This technique provides a means for modifying the dynamic range of data acquired by altering it into a desired distribution. In experimentation, equalizer characteristic functions are derived for a set of selected input delays to obtain the desired output. The delay equalizer system developed here is suited for deployment in a distributed hierarchical conferencing environment. To accommodate a broadcast continuity, the multimedia presentation is

  17. The Limitations to Delay-Insensitivity in Asynchronous Circuits

    National Research Council Canada - National Science Library

    Martin, Alain J

    1990-01-01

    ... produced are delay-insensitive (DI). A digital circuit is DI when its correct operation is independent of the delays in operators and in the wires connecting the operators, except that the delays are finite and positive...

  18. Global synchronization in arrays of delayed neural networks with constant and delayed coupling

    International Nuclear Information System (INIS)

    Cao Jinde; Li Ping; Wang Weiwei

    2006-01-01

    This Letter investigates the global exponential synchronization in arrays of coupled identical delayed neural networks (DNNs) with constant and delayed coupling. By referring to Lyapunov functional method and Kronecker product technique, some sufficient conditions are derived for global synchronization of such systems. These new synchronization criteria offer some adjustable matrix parameters, which is of important significance in the design and applications of such coupled DNNs, and the results improve and extend the earlier works. Finally, an example is given to illustrate the theoretical results

  19. Strategies for operation of containment related ESFs in managing activity release to the environment during accident conditions

    International Nuclear Information System (INIS)

    Bhawal, R.N.; Bajaj, S.S.

    1998-01-01

    In Indian PHWR design, a double containment concept with passive vapour suppression pool (to limit peak pressure) system has been adopted. In addition to it, various Engineered Safety Features (ESFs) have been incorporated to limit the release of radioactivity to the environment. They are: Reactor building emergency coolers for cooling which results in fast reduction of overpressure; Primary Containment Filtration and Pump Back System (PCFPBS) for reduction in iodine concentration inside RB atmosphere during post LOCA period; and, Primary Containment Controlled Discharge System (PCCDS) for the rapid reduction of over-pressure tail. Due to operation of secondary containment purge system, which maintain negative pressure in the annulus, the ground level release is negligibly small. However, if non- availability of negative pressure in secondary containment space is assumed, then operation of PCFPBS and PCCDS system reduces the ground level release significantly. In this situation, depending upon time of operation of the PCFPBS, it can effectively reduce the iodine release, both in stack level and ground level by trapping it in charcoal filters. It is seen that delay time of PCFPBS operation in conjunction with prevailing weather condition can be manipulated to reduce the effect of stack level release of iodine. In this paper the containment related ESFs used in Indian PHWR is discussed in brief and the effectiveness of operator actions and management strategies in actuation of the ESFs in reducing the activity release to environment (during postulated accident conditions) will be brought out. (author)

  20. Delays in the operating room: signs of an imperfect system.

    Science.gov (United States)

    Wong, Janice; Khu, Kathleen Joy; Kaderali, Zul; Bernstein, Mark

    2010-06-01

    Delays in the operating room have a negative effect on its efficiency and the working environment. In this prospective study, we analyzed data on perioperative system delays. One neurosurgeon prospectively recorded all errors, including perioperative delays, for consecutive patients undergoing elective procedures from May 2000 to February 2009. We analyzed the prevalence, causes and impact of perioperative system delays that occurred in one neurosurgeon's practice. A total of 1531 elective surgical cases were performed during the study period. Delays were the most common type of error (33.6%), and more than half (51.4%) of all cases had at least 1 delay. The most common cause of delay was equipment failure. The first cases of the day and cranial cases had more delays than subsequent cases and spinal cases, respectively. A delay in starting the first case was associated with subsequent delays. Delays frequently occur in the operating room and have a major effect on patient flow and resource utilization. Thorough documentation of perioperative delays provides a basis for the development of solutions for improving operating room efficiency and illustrates the principles underlying the causes of operating room delays across surgical disciplines.

  1. A hybrid approach to parameter identification of linear delay differential equations involving multiple delays

    Science.gov (United States)

    Marzban, Hamid Reza

    2018-05-01

    In this paper, we are concerned with the parameter identification of linear time-invariant systems containing multiple delays. The approach is based upon a hybrid of block-pulse functions and Legendre's polynomials. The convergence of the proposed procedure is established and an upper error bound with respect to the L2-norm associated with the hybrid functions is derived. The problem under consideration is first transformed into a system of algebraic equations. The least squares technique is then employed for identification of the desired parameters. Several multi-delay systems of varying complexity are investigated to evaluate the performance and capability of the proposed approximation method. It is shown that the proposed approach is also applicable to a class of nonlinear multi-delay systems. It is demonstrated that the suggested procedure provides accurate results for the desired parameters.

  2. Do shorter delays to care and mental health system renewal translate into better occupational outcome after mental disorder diagnosis in a cohort of Canadian military personnel who returned from an Afghanistan deployment?

    Science.gov (United States)

    Boulos, David; Zamorski, Mark A

    2015-12-07

    Mental disorders in military personnel result in high rates of attrition. Military organisations have strengthened their mental health systems and attempted to overcome barriers to care in order to see better outcomes. This study investigated the roles of mental health services renewal and delay to care in Canadian Armed Forces (CAF) personnel diagnosed with mental disorders. Administrative data were used to identify a retrospective cohort of 30,513 CAF personnel who deployed in support of the mission in Afghanistan. Study participants included 508 individuals with a mental disorder diagnosis identified from CAF medical records of a weighted, stratified random sample of 2014 individuals selected from the study cohort. Weighted Cox proportional hazards regression assessed the association of diagnosis era and delay to care with the outcome, after controlling for a broad range of potential confounders (eg, disorder severity, comorbidity). Taylor series linearisation methods and sample design weights were applied in generating descriptive and regression analysis statistics. The outcome was release from military service for medical reasons, assessed using administrative data for the 508 individuals with a mental disorder diagnosis. 17.5% (95% CI 16.0% to 19.0%) of the cohort had a mental disorder diagnosis after an Afghanistan-related deployment, of which 21.3% (95% CI 17.2% to 25.5%) had a medical release over a median follow-up of 3.5 years. Medical release risk was elevated for individuals diagnosed before 30 April 2008 relative to those with recent diagnoses (adjusted HR (aHR)=1.77 (95% CI 1.01 to 3.11)) and for individuals with a long delay to care (>21 months after return) relative to those with intermediate delays (8-21 months, aHR 2.47=(95% CI 1.28 to 4.76)). Mental health services renewal in the CAF was associated with a better occupational outcome for those diagnosed with mental disorders. Longer delays to care were associated with a less favourable outcome

  3. Vaccination improves survival of Baltic salmon ( Salmo salar ) smolts in delayed release sea ranching (net-pen period)

    DEFF Research Database (Denmark)

    Buchmann, Kurt; Dalsgaard, Inger; Nielsen, Michael Engelbrecht

    1997-01-01

    Baltic salmon (Salmo salar) of the Finnish Iijoki stock were hatched and reared in freshwater in a salmon hatchery on the Danish island of Bornholm in the Baltic sea. Salmon parr were divided in three groups each comprising 22 000 fish. One group was vaccinated by intraperitoneal injection....... In contrast, no increase of titres was seen in the bath vaccinated and untreated groups. Marked cellular reactions in the abdominal cavity of injected fish were registered. A total of 3000 fish have been tagged and released to evaluate the effect of vaccination on the recapture rate. The implications...

  4. Introduction to Focus Issue: Time-delay dynamics

    Science.gov (United States)

    Erneux, Thomas; Javaloyes, Julien; Wolfrum, Matthias; Yanchuk, Serhiy

    2017-11-01

    The field of dynamical systems with time delay is an active research area that connects practically all scientific disciplines including mathematics, physics, engineering, biology, neuroscience, physiology, economics, and many others. This Focus Issue brings together contributions from both experimental and theoretical groups and emphasizes a large variety of applications. In particular, lasers and optoelectronic oscillators subject to time-delayed feedbacks have been explored by several authors for their specific dynamical output, but also because they are ideal test-beds for experimental studies of delay induced phenomena. Topics include the control of cavity solitons, as light spots in spatially extended systems, new devices for chaos communication or random number generation, higher order locking phenomena between delay and laser oscillation period, and systematic bifurcation studies of mode-locked laser systems. Moreover, two original theoretical approaches are explored for the so-called Low Frequency Fluctuations, a particular chaotical regime in laser output which has attracted a lot of interest for more than 30 years. Current hot problems such as the synchronization properties of networks of delay-coupled units, novel stabilization techniques, and the large delay limit of a delay differential equation are also addressed in this special issue. In addition, analytical and numerical tools for bifurcation problems with or without noise and two reviews on concrete questions are proposed. The first review deals with the rich dynamics of simple delay climate models for El Nino Southern Oscillations, and the second review concentrates on neuromorphic photonic circuits where optical elements are used to emulate spiking neurons. Finally, two interesting biological problems are considered in this Focus Issue, namely, multi-strain epidemic models and the interaction of glucose and insulin for more effective treatment.

  5. Prospective analysis of delayed colorectal post-polypectomy bleeding.

    Science.gov (United States)

    Park, Soo-Kyung; Seo, Jeong Yeon; Lee, Min-Gu; Yang, Hyo-Joon; Jung, Yoon Suk; Choi, Kyu Yong; Kim, Hungdai; Kim, Hyung Ook; Jung, Kyung Uk; Chun, Ho-Kyung; Park, Dong Il

    2018-01-17

    Although post-polypectomy bleeding is the most frequent complication after colonoscopic polypectomy, only few studies have investigated the incidence of bleeding prospectively. The aim of this study was to investigate the incidence of delayed post-polypectomy bleeding and its associated risk factors prospectively. Patients who underwent colonoscopic polypectomy at Kangbuk Samsung Hospital from January 2013 to December 2014 were prospectively enrolled in this study. Trained nurses contacted patients via telephone 7 and 30 days after polypectomy and completed a standardized questionnaire regarding the development of bleeding. Delayed post-polypectomy bleeding was categorized as minor or major and early or late bleeding. Major delayed bleeding was defined as a > 2-g/dL drop in the hemoglobin level, requiring hospitalization for control of bleeding or blood transfusion; late delayed bleeding was defined as bleeding occurring later than 24 h after polypectomy. A total of 8175 colonoscopic polypectomies were performed in 3887 patients. Overall, 133 (3.4%) patients developed delayed post-polypectomy bleeding. Among them, 90 (2.3%) and 43 (1.1%) patients developed minor and major delayed bleeding, respectively, and 39 (1.0%) patients developed late delayed bleeding. In the polyp-based multivariate analysis, young age ( 10 mm (OR 2.45; 95% CI 1.38-4.36) were significant risk factors for major delayed bleeding, while young age (< 50 years; OR 2.6; 95% CI 1.35-5.12) and immediate bleeding (OR 3.3; 95% CI 1.49-7.30) were significant risk factors for late delayed bleeding. Young age, aspirin use, polyp size, and immediate bleeding were found to be independent risk factors for delayed post-polypectomy bleeding.

  6. Delayed Complications After Transsphenoidal Surgery for Pituitary Adenomas.

    Science.gov (United States)

    Alzhrani, Gmaan; Sivakumar, Walavan; Park, Min S; Taussky, Philipp; Couldwell, William T

    2018-01-01

    Perioperative complications after transsphenoidal surgery for pituitary adenomas have been well documented in the literature; however, some complications can occur in a delayed fashion postoperatively, and reports are sparse about their occurrence, management, and outcome. Here, we describe delayed complications after transsphenoidal surgery and discuss the incidence, temporality from the surgery, and management of these complications based on the findings of studies that reported delayed postoperative epistaxis, delayed postoperative cavernous carotid pseudoaneurysm formation and rupture, vasospasm, delayed symptomatic hyponatremia, hypopituitarism, hydrocephalus, and sinonasal complications. Our findings from this review revealed an incidence of 0.6%-3.3% for delayed postoperative epistaxis at 1-3 weeks postoperatively, 18 reported cases of delayed carotid artery pseudoaneurysm formation at 2 days to 10 years postoperatively, 30 reported cases of postoperative vasospasm occurring 8 days postoperatively, a 3.6%-19.8% rate of delayed symptomatic hyponatremia at 4-7 days postoperatively, a 3.1% rate of new-onset hypopituitarism at 2 months postoperatively, and a 0.4%-5.8% rate of hydrocephalus within 2.2 months postoperatively. Sinonasal complications are commonly reported after transsphenoidal surgery, but spontaneous resolutions within 3-12 months have been reported. Although the incidence of some of these complications is low, providing preoperative counseling to patients with pituitary tumors regarding these delayed complications and proper postoperative follow-up planning is an important part of treatment planning. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Optical resonators for true-time-delay beam steering

    Science.gov (United States)

    Gesell, Leslie H.; Evanko, Stephen M.

    1996-06-01

    Conventional true time delay beamforming and steering devices rely on switching between various lengths of delay line. Therefore only discrete delays are possible. Proposed is a new photonics concept for true time delay beamforming which provides a finely controlled continuum of delays with switching speeds on the order of 10's of nanoseconds or faster. The architecture uses an array of waveguide cavities with different resonate frequencies to channelize the signal. Each spectral component of the signal is phase shifted by an amount proportional to the frequency of that component and the desired time delay. These phase shifted spectral components are then summed to obtain the delayed signal. This paper provides an overview of the results of a Phase I SBIR contract where this concept has been refined and analyzed. The parameters for an operational system are determined and indication of the feasibility of this approach is given. Among the issues addressed are the requirements of the resonators and the methods necessary to implement fiber optic Bragg gratings as these resonators.

  8. Methods to estimate railway capacity and passenger delays

    DEFF Research Database (Denmark)

    Landex, Alex

    that an evaluation of passenger delays obtained with simulation software (in this case RailSys) and the passenger delay model is comparable with the daily operation of the Copenhagen suburban railway network. Using a microscopic simulation model, the thesis demonstrates that it is possible to compare travel times...... of additional travel time. The differences between the different kinds of delay (train delays, passenger delays and scheduled waiting time) are illustrated through simple, but representative, case examples in CHAPTER 10. The examples demonstrate that 3rd generation passenger delay models are more realistic than...... depend on the given infrastructure and timetable and can result in longer travel times for trains and passengers. Furthermore, the thesis shows that the network effects can result in reduced capacity as some trains or train services can make it impossible to operate other planned/desired trains or train...

  9. Effect of Temperature, Pressure and Equivalence Ratio on Ignition Delay in Ignition Quality Tester (IQT): Diesel,n-Heptane, andiso-Octane Fuels under Low Temperature Conditions

    KAUST Repository

    Yang, Seung Yeon

    2015-11-02

    Effects of temperature, pressure and global equivalence ratio on total ignition delay time in a constant volume spray combustion chamber were investigated for diesel fuel along with the primary reference fuels (PRFs) of n-heptane and iso-octane in relatively low temperature conditions to simulate unsteady spray ignition behavior. A KAUST Research ignition quality tester (KR-IQT) was utilized, which has a feature of varying temperature, pressure and equivalence ratio using a variable displacement fuel pump. A gradient method was adopted in determining the start of ignition in order to compensate pressure increase induced by low temperature heat release. Comparison of this method with other existing methods was discussed. Ignition delay times were measured at various equivalence ratios (0.5-1.7) with the temperatures of initial charge air in the range from 698 to 860 K and the pressures in the range of 1.5 to 2.1 MPa, pertinent to low temperature combustion (LTC) conditions. An attempt to scale the effect of pressure on total ignition delay was undertaken and the equivalence ratio exponent and activation energy in the Arrhenius expression of total ignition delay were determined. Ignition delay results indicated that there were strong correlations of pressure, temperature, and equivalence ratio under most conditions studied except at relatively low pressures. Diesel (DCN 52.5) and n-heptane (DCN 54) fuels exhibited reasonably similar ignition delay characteristics, while iso-octane showed a distinct behavior under low temperature regime having a two-stage ignition, which substantiate the adoption of the gradient method in determining ignition delay.

  10. Chaos in the delay logistic equation with discontinuous delays

    International Nuclear Information System (INIS)

    Sen, Ayan; Mukherjee, Debasis

    2009-01-01

    This paper analyzes a delay logistic equation which models a feedback control problem. Interval map associated to the system is derived. By calculating Lyapunov exponent, we indicate stable orbit and chaotic phenomenon respectively. The results are verified through computer simulation. We identify the parameter which controls the dynamics.

  11. Model‐Informed Development and Registration of a Once‐Daily Regimen of Extended‐Release Tofacitinib

    Science.gov (United States)

    Lamba, M; Hutmacher, MM; Furst, DE; Dikranian, A; Dowty, ME; Conrado, D; Stock, T; Nduaka, C; Cook, J

    2017-01-01

    Extended‐release (XR) formulations enable less frequent dosing vs. conventional (e.g., immediate release (IR)) formulations. Regulatory registration of such formulations typically requires pharmacokinetic (PK) and clinical efficacy data. Here we illustrate a model‐informed, exposure–response (E‐R) approach to translate controlled trial data from one formulation to another without a phase III trial, using a tofacitinib case study. Tofacitinib is an oral Janus kinase (JAK) inhibitor for the treatment of rheumatoid arthritis (RA). E‐R analyses were conducted using validated clinical endpoints from phase II dose–response and nonclinical dose fractionation studies of the IR formulation. Consistent with the delay in clinical response dynamics relative to PK, average concentration was established as the relevant PK parameter for tofacitinib efficacy and supported pharmacodynamic similarity. These evaluations, alongside demonstrated equivalence in total systemic exposure between IR and XR formulations, provided the basis for the regulatory approval of tofacitinib XR once daily by the US Food and Drug Administration. PMID:27859030

  12. Delay-induced wave instabilities in single-species reaction-diffusion systems

    Science.gov (United States)

    Otto, Andereas; Wang, Jian; Radons, Günter

    2017-11-01

    The Turing (wave) instability is only possible in reaction-diffusion systems with more than one (two) components. Motivated by the fact that a time delay increases the dimension of a system, we investigate the presence of diffusion-driven instabilities in single-species reaction-diffusion systems with delay. The stability of arbitrary one-component systems with a single discrete delay, with distributed delay, or with a variable delay is systematically analyzed. We show that a wave instability can appear from an equilibrium of single-species reaction-diffusion systems with fluctuating or distributed delay, which is not possible in similar systems with constant discrete delay or without delay. More precisely, we show by basic analytic arguments and by numerical simulations that fast asymmetric delay fluctuations or asymmetrically distributed delays can lead to wave instabilities in these systems. Examples, for the resulting traveling waves are shown for a Fisher-KPP equation with distributed delay in the reaction term. In addition, we have studied diffusion-induced instabilities from homogeneous periodic orbits in the same systems with variable delay, where the homogeneous periodic orbits are attracting resonant periodic solutions of the system without diffusion, i.e., periodic orbits of the Hutchinson equation with time-varying delay. If diffusion is introduced, standing waves can emerge whose temporal period is equal to the period of the variable delay.

  13. Stability results for stochastic delayed recurrent neural networks with discrete and distributed delays

    Science.gov (United States)

    Chen, Guiling; Li, Dingshi; Shi, Lin; van Gaans, Onno; Verduyn Lunel, Sjoerd

    2018-03-01

    We present new conditions for asymptotic stability and exponential stability of a class of stochastic recurrent neural networks with discrete and distributed time varying delays. Our approach is based on the method using fixed point theory, which do not resort to any Liapunov function or Liapunov functional. Our results neither require the boundedness, monotonicity and differentiability of the activation functions nor differentiability of the time varying delays. In particular, a class of neural networks without stochastic perturbations is also considered. Examples are given to illustrate our main results.

  14. Delay and reward choice in ADHD: an experimental test of the role of delay aversion.

    Science.gov (United States)

    Marco, Rafaela; Miranda, Ana; Schlotz, Wolff; Melia, Amanda; Mulligan, Aisling; Müller, Ueli; Andreou, Penny; Butler, Louise; Christiansen, Hanna; Gabriels, Isabel; Medad, Sheera; Albrecht, Bjorn; Uebel, Henrik; Asherson, Phillip; Banaschewski, Tobias; Gill, Michael; Kuntsi, Jonna; Mulas, Fernando; Oades, Robert; Roeyers, Herbert; Steinhausen, Hans-Christoph; Rothenberger, Aribert; Faraone, Stephen V; Sonuga-Barke, Edmund J S

    2009-05-01

    Children with attention deficit/hyperactivity disorder (ADHD) choose smaller sooner (SS) over larger later (LL) rewards more than controls. Here we assess the contributions of impulsive drive for immediate rewards (IDIR) and delay aversion (DAv) to this pattern. We also explore the characteristics of, and the degree of familiality in, ADHD SS responders. We had 360 ADHD probands; 349 siblings and 112 controls (aged between 6 to 17 years) chose between SS (1 point after 2 s) and LL reward (2 points after 30 s) outcomes on the Maudsley Index of Delay Aversion (Kuntsi, Oosterlaan, & Stevenson, 2001): Under one condition SS choice led to less overall trial delay under another it did not. ADHD participants chose SS more than controls under both conditions. This effect was larger when SS choice reduced trial delay. ADHD SS responders were younger, had lower IQ, more conduct disorder and had siblings who were more likely to be SS responders themselves. The results support a dual component model in which both IDIR and DAv contribute to SS choice in ADHD. SS choice may be a marker of an ADHD motivational subtype.

  15. UWB delay and multiply receiver

    Energy Technology Data Exchange (ETDEWEB)

    Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Romero, Carlos E.

    2013-09-10

    An ultra-wideband (UWB) delay and multiply receiver is formed of a receive antenna; a variable gain attenuator connected to the receive antenna; a signal splitter connected to the variable gain attenuator; a multiplier having one input connected to an undelayed signal from the signal splitter and another input connected to a delayed signal from the signal splitter, the delay between the splitter signals being equal to the spacing between pulses from a transmitter whose pulses are being received by the receive antenna; a peak detection circuit connected to the output of the multiplier and connected to the variable gain attenuator to control the variable gain attenuator to maintain a constant amplitude output from the multiplier; and a digital output circuit connected to the output of the multiplier.

  16. Assessment of Confounding in Studies of Delay and Survival

    DEFF Research Database (Denmark)

    Tørring, Marie Louise; Vedsted, Peter; Frydenberg, Morten

    BACKGROUND: Whether longer time to diagnosis (diagnostic delay) in patients with cancer symptoms is directly and independently associated with poor prognosis cannot be determined in randomised controlled trials. Analysis of observational data is therefore necessary. Many previous studies of the i......BACKGROUND: Whether longer time to diagnosis (diagnostic delay) in patients with cancer symptoms is directly and independently associated with poor prognosis cannot be determined in randomised controlled trials. Analysis of observational data is therefore necessary. Many previous studies......) Clarify which factors are considered confounders or intermediate variables in the literature. 2) Assess how and to what extent these factors bias survival estimates. CONSIDERATIONS: As illustrated in Figure 1, symptoms of cancer may alert patients, GP's, and hospital doctors differently and influence both...... delay and survival time in different ways. We therefore assume that the impact of confounding factors depends on the type of delay studied (e.g., patient delay, GP delay, referral delay, or treatment delay). MATERIALS & METHODS: The project includes systematic review and methodological developments...

  17. Theory and use of GIRAFFE for analysis of decay characteristics of delayed-neutron precursors in an LMFBR

    International Nuclear Information System (INIS)

    Gross, K.C.

    1980-07-01

    The application of the computer code GIRAFFE (General Isotope Release Analysis For Failed Elements) written in FORTRAN IV is described. GIRAFFE was designed to provide parameter estimates of the nonlinear discrete-measurement models that govern the transport and decay of delayed-neutron precursors in a liquid-metal fast breeder reactor (LMFBR). The code has been organized into a set of small, relatively independent and well-defined modules to facilitate modification and maintenance. The program logic, the numerical techniques, and the methods of solution used by the code are presented, and the functions of the MAIN program and of each subroutine are discussed

  18. Drug release kinetic analysis and prediction of release data via polymer molecular weight in sustained release diltiazem matrices.

    Science.gov (United States)

    Adibkia, K; Ghanbarzadeh, S; Mohammadi, G; Khiavi, H Z; Sabzevari, A; Barzegar-Jalali, M

    2014-03-01

    This study was conducted to investigate the effects of HPMC (K4M and K100M) as well as tragacanth on the drug release rate of diltiazem (DLTZ) from matrix tablets prepared by direct compression method.Mechanism of drug transport through the matrices was studied by fitting the release data to the 10 kinetic models. 3 model independent parameters; i. e., mean dissolution time (MDT), mean release rate (MRR) and release rate efficacy (RE) as well as 5 time point approaches were established to compare the dissolution profiles. To find correlation between fraction of drug released and polymer's molecular weight, dissolution data were fitted into two proposed equations.All polymers could sustain drug release up to 10 h. The release data were fitted best to Peppas and Higuchi square root kinetic models considering squared correlation coefficient and mean percent error (MPE). RE and MRR were decreased when polymer to drug ratio was increased. Conversely, t60% was increased with raising polymer /drug ratio. The fractions of drug released from the formulations prepared with tragacanth were more than those formulated using the same amount of HPMC K4M and HPMC K100M.Preparation of DLTZ matrices applying HPMCK4M, HPMC K100M and tragacanth could effectively extend the drug release. © Georg Thieme Verlag KG Stuttgart · New York.

  19. A delay-dependent approach to robust control for neutral uncertain neural networks with mixed interval time-varying delays

    International Nuclear Information System (INIS)

    Lu, Chien-Yu

    2011-01-01

    This paper considers the problem of delay-dependent global robust stabilization for discrete, distributed and neutral interval time-varying delayed neural networks described by nonlinear delay differential equations of the neutral type. The parameter uncertainties are norm bounded. The activation functions are assumed to be bounded and globally Lipschitz continuous. Using a Lyapunov functional approach and linear matrix inequality (LMI) techniques, the stability criteria for the uncertain neutral neural networks with interval time-varying delays are established in the form of LMIs, which can be readily verified using the standard numerical software. An important feature of the result reported is that all the stability conditions are dependent on the upper and lower bounds of the delays. Another feature of the results lies in that it involves fewer free weighting matrix strategy, and upper bounds of the inner product between two vectors are not introduced to reduce the conservatism of the criteria. Two illustrative examples are provided to demonstrate the effectiveness and the reduced conservatism of the proposed method

  20. Accelerated in-vitro release testing methods for extended-release parenteral dosage forms.

    Science.gov (United States)

    Shen, Jie; Burgess, Diane J

    2012-07-01

    This review highlights current methods and strategies for accelerated in-vitro drug release testing of extended-release parenteral dosage forms such as polymeric microparticulate systems, lipid microparticulate systems, in-situ depot-forming systems and implants. Extended-release parenteral dosage forms are typically designed to maintain the effective drug concentration over periods of weeks, months or even years. Consequently, 'real-time' in-vitro release tests for these dosage forms are often run over a long time period. Accelerated in-vitro release methods can provide rapid evaluation and therefore are desirable for quality control purposes. To this end, different accelerated in-vitro release methods using United States Pharmacopeia (USP) apparatus have been developed. Different mechanisms of accelerating drug release from extended-release parenteral dosage forms, along with the accelerated in-vitro release testing methods currently employed are discussed. Accelerated in-vitro release testing methods with good discriminatory ability are critical for quality control of extended-release parenteral products. Methods that can be used in the development of in-vitro-in-vivo correlation (IVIVC) are desirable; however, for complex parenteral products this may not always be achievable. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

  1. Accelerated in vitro release testing methods for extended release parenteral dosage forms

    Science.gov (United States)

    Shen, Jie; Burgess, Diane J.

    2012-01-01

    Objectives This review highlights current methods and strategies for accelerated in vitro drug release testing of extended release parenteral dosage forms such as polymeric microparticulate systems, lipid microparticulate systems, in situ depot-forming systems, and implants. Key findings Extended release parenteral dosage forms are typically designed to maintain the effective drug concentration over periods of weeks, months or even years. Consequently, “real-time” in vitro release tests for these dosage forms are often run over a long time period. Accelerated in vitro release methods can provide rapid evaluation and therefore are desirable for quality control purposes. To this end, different accelerated in vitro release methods using United States Pharmacopoeia (USP) apparatus have been developed. Different mechanisms of accelerating drug release from extended release parenteral dosage forms, along with the accelerated in vitro release testing methods currently employed are discussed. Conclusions Accelerated in vitro release testing methods with good discriminatory ability are critical for quality control of extended release parenteral products. Methods that can be used in the development of in vitro-in vivo correlation (IVIVC) are desirable, however for complex parenteral products this may not always be achievable. PMID:22686344

  2. Gravitational Lens Time Delays Using Polarization Monitoring

    Directory of Open Access Journals (Sweden)

    Andrew Biggs

    2017-11-01

    Full Text Available Gravitational lens time delays provide a means of measuring the expansion of the Universe at high redshift (and therefore in the ‘Hubble flow’ that is independent of local calibrations. It was hoped that many of the radio lenses found in the JVAS/CLASS survey would yield time delays as these were selected to have flat spectra and are dominated by multiple compact components. However, despite extensive monitoring with the Very Large Array (VLA, time delays have only been measured for three of these systems (out of 22. We have begun a programme to reanalyse the existing VLA monitoring data with the goal of producing light curves in polarized flux and polarization position angle, either to improve delay measurements or to find delays for new sources. Here, we present preliminary results on the lens system B1600+434 which demonstrate the presence of correlated and substantial polarization variability in each image.

  3. Experimentally reduced corticosterone release promotes early breeding in black-legged kittiwakes.

    Science.gov (United States)

    Goutte, Aurélie; Clément-Chastel, Céline; Moe, Børge; Bech, Claus; Gabrielsen, Geir Wing; Chastel, Olivier

    2011-06-15

    Breeding at the right time is important for successful reproduction. In birds, stressful environmental conditions are known to delay the timing of breeding but the underlying mechanisms are poorly understood. The stress hormone corticosterone appears to be a good candidate for mediating egg-laying date according to early environmental conditions and physiological state. By experimentally reducing the release of corticosterone in black-legged kittiwakes during the pre-laying period, we tested whether egg-laying date was mechanistically linked to corticosterone levels. Male and female kittiwakes were implanted with a low dose of exogenous corticosterone to inhibit endogenous corticosterone production. According to our predictions, the experimental reduction of corticosterone release was paralleled by a significant advancement of egg laying in females (around 4 days earlier). In addition, females with experimentally reduced corticosterone release gained mass during the pre-laying period compared with controls. Ultimately, the advancement of egg laying in females with experimentally reduced corticosterone levels was associated with an enhanced breeding success. This effect was strongly sex specific. In corticosterone-treated male kittiwakes, egg-laying date and reproductive success were not affected, but breeding probability was lower than in controls. This corticosterone treatment did not influence immediate clutch size, or return rate and breeding decision the following year. Our results support the hypothesis that corticosterone secretion during the pre-laying period mediates the timing of breeding in this long-lived seabird, possibly through the dynamics of energy reserves.

  4. Optical True Time Delay for Phased Array Antennas Composed of 2×2 Optical MEMS Switches and Fiber Delay Lines

    Institute of Scientific and Technical Information of China (English)

    Back-Song; Lee; Jong-Dug; Shin; Boo-Gyoun; Kim

    2003-01-01

    We proposed an optical true time delay (TTD) for phased array antennas (PAAs) composed of 2×2 optical MEMS switches, single-mode fiber delay lines, and a fixed wavelength laser diode. A 3-bit TTD for 10 GHz PAAs was implemented with a time delay error less than ± 0.2 ps.

  5. Chitosan films incorporated with nettle (Urtica Dioica L.) extract-loaded nanoliposomes: II. Antioxidant activity and release properties.

    Science.gov (United States)

    Almasi, Hadi; Zandi, Mohsen; Beigzadeh, Sara; Haghju, Sara; Mehrnow, Nazila

    2016-07-14

    Chitosan films were loaded with NE nettle (Urtica dioica L.) extract (NE) at concentrations of 0, 0.5, 1 and 1.5%w/w in the free or nanoliposomal form to obtain active and nanoactive films, respectively. The antioxidant potential of the films containing NE-loaded nanoliposomes was decreased in comparison of free NE incorporated films. Diffusion of NE to soybean oil was enough to delay the induction of the oxidation of soybean oil stored for 60 days in contact with chitosan based films. Release studies indicated that the release rate of NE in 95% ethanol simulant significantly decreased by the nanoencapsulation of NE. The diffusion coefficient (D) for chitosan films containing 1.5%w/w of free and encapsulated NE at 25 °C was 18.80 and 3.68 × 10 -7 cm 2  s -1 , respectively. Moreover, the formation of nanoliposomes diminished the increasing effect of temperature on the release rate as when storage temperature increased from 4 °C to 40 °C.

  6. Fast Heuristics for Delay Management with Passenger Rerouting

    NARCIS (Netherlands)

    T.A.B. Dollevoet (Twan); D. Huisman (Dennis)

    2011-01-01

    textabstractDelay management models determine which connections should be maintained in case of a delayed feeder train. Recently, delay management models are developed that take into account that passengers will adjust their routes when they miss a connection. However, for large-scale real-world

  7. Qualitative analysis of controlled release ciprofloxacin/carbopol 934 mucoadhesive suspension

    Directory of Open Access Journals (Sweden)

    Subhashree Sahoo

    2011-01-01

    Full Text Available Mucoadhesive polymeric (carbopol 934 suspension of ciprofloxacin was prepared by ultrasonication and optimized with the aim of developing an oral controlled release gastro-retentive dosage form. The qualitative analysis of the formulation was performed by fourier transform infrared spectroscopy (FTIR, Raman spectroscopy, X-ray powder diffraction (XRD, and scanning electron microscopy (SEM analyses. FTIR (400 cm-1 to 4000 cm-1 region and Raman (140 to 2400 cm-1 region Spectroscopic studies were carried out and the spectra were used for interpretation. XRD data of pure drug, polymer and the formulation were obtained using a powder diffractometer scanned from a Bragg′s angle (2q of 10° to 70°. The dispersion of the particle was observed using SEM techniques. The particle size distribution and aspect ratio of particles in the polymeric suspension were obtained from SEM image analysis. The results from FTIR and Raman spectroscopic analyses suggested that, in formulation, the carboxylic groups of ciprofloxacin and hydroxyl groups of C934 undergo a chemical interaction leading to esterification and hydrogen bonding. The XRD data suggested that the retention of crystalline nature of ciprofloxacin in the formulation would lead to increase in stability and drug loading; decrease in solubility; and delay in release of the drug from polymeric suspension with better bioavailability and penetration capacity. The SEM image analysis indicated that, in the formulation maximum particles were having aspect ratio from 2 to 4 and standard deviation was very less which provided supporting evidences for homogeneous, uniformly dispersed, stable controlled release ciprofloxacin suspension which would be pharmaceutically acceptable.

  8. Systematics in delayed neutron yields

    Energy Technology Data Exchange (ETDEWEB)

    Ohsawa, Takaaki [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.

    1998-03-01

    An attempt was made to reproduce the systematic trend observed in the delayed neutron yields for actinides on the basis of the five-Gaussian representation of the fission yield together with available data sets for delayed neutron emission probability. It was found that systematic decrease in DNY for heavier actinides is mainly due to decrease of fission yields of precursors in the lighter side of the light fragment region. (author)

  9. Diagnosis delay in tuberculosis and its consequences

    International Nuclear Information System (INIS)

    Habibullah, S.; Sheikh, M.A.; Sadiq, A.; Anwar, T.

    2004-01-01

    Objective: To find out the average duration from onset of symptoms to the diagnosis and treatment of tuberculosis, reasons for diagnostic delay, its consequences, association of variables and formulation of recommendations. Results: In this study it was found that average time from onset of initial symptoms to diagnosis and treatment of tuberculosis was 120 days. In 64% of the patients medical practitioners were responsible for delaying the diagnosis of tuberculosis. Loss of weight in 40% and haemoptysis is 21% were the consequences of diagnostic delay of tuberculosis. Delay in the diagnosis of tuberculosis was statistically significant in those patients who consulted private practitioners, and consequences of tuberculosis were severe in those patients who consulted late. (author)

  10. News/Press Releases

    Data.gov (United States)

    Office of Personnel Management — A press release, news release, media release, press statement is written communication directed at members of the news media for the purpose of announcing programs...

  11. Acute gonadotropin-releasing hormone agonist treatment enhances extinction memory in male rats.

    Science.gov (United States)

    Maeng, L Y; Taha, M B; Cover, K K; Glynn, S S; Murillo, M; Lebron-Milad, K; Milad, M R

    2017-08-01

    Leuprolide acetate (LEU), also known as Lupron, is commonly used to treat prostate cancer in men. As a gonadotropin-releasing hormone (GnRH) receptor agonist, it initially stimulates the release of gonadal hormones, testosterone (T) and estradiol. This surge eventually suppresses these hormones, preventing the further growth and spread of cancer cells. Individuals receiving this treatment often report anxiety and cognitive changes, but LEU's effects on the neural mechanisms that are involved in anxiety during the trajectory of treatment are not well known. In this study, we examined the acute effects of LEU on fear extinction, hypothesizing that increased T levels following a single administration of LEU will facilitate extinction recall by altering neuronal activity within the fear extinction circuitry. Two groups of naïve adult male rats underwent a 3-day fear conditioning, extinction, and recall experiment. The delayed group (n=15) received a single injection of vehicle or LEU (1.2mg/kg) 3weeks before behavioral testing. The acute group (n=25) received an injection one day after fear conditioning, 30min prior to extinction training. Following recall, the brains for all animals were collected for c-fos immunohistochemistry. Blood samples were also collected and assayed for T levels. Acute administration of LEU increased serum T levels during extinction training and enhanced extinction recall 24h later. This enhanced extinction memory was correlated with increased c-fos activity within the infralimbic cortex and amygdala, which was not observed in the delayed group. These results suggest that the elevation in T induced by acute administration of LEU can influence extinction memory consolidation, perhaps through modification of neuronal activity within the infralimbic cortex and amygdala. This may be an important consideration in clinical applications of LEU and its effects on anxiety and cognition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Delayed child-bearing.

    Science.gov (United States)

    Johnson, Jo-Ann; Tough, Suzanne

    2012-01-01

    To provide an overview of delayed child-bearing and to describe the implications for women and health care providers. Delayed child-bearing, which has increased greatly in recent decades, is associated with an increased risk of infertility, pregnancy complications, and adverse pregnancy outcome. This guideline provides information that will optimize the counselling and care of Canadian women with respect to their reproductive choices. Maternal age is the most important determinant of fertility, and obstetric and perinatal risks increase with maternal age. Many women are unaware of the success rates or limitations of assisted reproductive technology and of the increased medical risks of delayed child-bearing, including multiple births, preterm delivery, stillbirth, and Caesarean section. This guideline provides a framework to address these issues. Studies published between 2000 and August 2010 were retrieved through searches of PubMed and the Cochrane Library using appropriate key words (delayed child-bearing, deferred pregnancy, maternal age, assisted reproductive technology, infertility, and multiple births) and MeSH terms (maternal age, reproductive behaviour, fertility). The Internet was also searched using similar key words, and national and international medical specialty societies were searched for clinical practice guidelines and position statements. Data were extracted based on the aims, sample, authors, year, and results. The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). The Society of Obstetricians and Gynaecologists of Canada. RECOMMENDATIONS 1. Women who delay child-bearing are at increased risk of infertility. Prospective parents, especially women, should know that their fecundity and fertility begin to decline significantly after 32 years of age. Prospective parents should know that assisted reproductive technologies cannot guarantee a live birth or completely

  13. Contamination delays the release of Laricobius osakensis for biological control of hemlock woolly adelgid: cryptic diversity in Japanese Laricobius spp

    Science.gov (United States)

    Melissa J. Fischer; Nathan P. Havill; Carrie S. Jubb; Sean W. Prosser; Brent D. Opell; Scott M. Salom; Loke T. Kok

    2014-01-01

    Laricobius osakensis (Coleoptera: Derodontidae) was imported from Japan to the United States in 2006 for study in quarantine facilities as a potential biological control of Hemlock Woolly Adelgid. Laricobius osakensis was released from quarantine in 2010, but it was soon discovered that the colony also contained a cryptic species...

  14. Understanding the delayed-keyword effect on metacomprehension accuracy.

    Science.gov (United States)

    Thiede, Keith W; Dunlosky, John; Griffin, Thomas D; Wiley, Jennifer

    2005-11-01

    The typical finding from research on metacomprehension is that accuracy is quite low. However, recent studies have shown robust accuracy improvements when judgments follow certain generation tasks (summarizing or keyword listing) but only when these tasks are performed at a delay rather than immediately after reading (K. W. Thiede & M. C. M. Anderson, 2003; K. W. Thiede, M. C. M. Anderson, & D. Therriault, 2003). The delayed and immediate conditions in these studies confounded the delay between reading and generation tasks with other task lags, including the lag between multiple generation tasks and the lag between generation tasks and judgments. The first 2 experiments disentangle these confounded manipulations and provide clear evidence that the delay between reading and keyword generation is the only lag critical to improving metacomprehension accuracy. The 3rd and 4th experiments show that not all delayed tasks produce improvements and suggest that delayed generative tasks provide necessary diagnostic cues about comprehension for improving metacomprehension accuracy.

  15. Managing contamination delay to improve Timing Speculation architectures

    Directory of Open Access Journals (Sweden)

    Naga Durga Prasad Avirneni

    2016-08-01

    Full Text Available Timing Speculation (TS is a widely known method for realizing better-than-worst-case systems. Aggressive clocking, realizable by TS, enable systems to operate beyond specified safe frequency limits to effectively exploit the data dependent circuit delay. However, the range of aggressive clocking for performance enhancement under TS is restricted by short paths. In this paper, we show that increasing the lengths of short paths of the circuit increases the effectiveness of TS, leading to performance improvement. Also, we propose an algorithm to efficiently add delay buffers to selected short paths while keeping down the area penalty. We present our algorithm results for ISCAS-85 suite and show that it is possible to increase the circuit contamination delay by up to 30% without affecting the propagation delay. We also explore the possibility of increasing short path delays further by relaxing the constraint on propagation delay and analyze the performance impact.

  16. The effects of the framing of time on delay discounting.

    Science.gov (United States)

    DeHart, William Brady; Odum, Amy L

    2015-01-01

    We examined the effects of the framing of time on delay discounting. Delay discounting is the process by which delayed outcomes are devalued as a function of time. Time in a titrating delay discounting task is often framed in calendar units (e.g., as 1 week, 1 month, etc.). When time is framed as a specific date, delayed outcomes are discounted less compared to the calendar format. Other forms of framing time; however, have not been explored. All participants completed a titrating calendar unit delay-discounting task for money. Participants were also assigned to one of two delay discounting tasks: time as dates (e.g., June 1st, 2015) or time in units of days (e.g., 5000 days), using the same delay distribution as the calendar delay-discounting task. Time framed as dates resulted in less discounting compared to the calendar method, whereas time framed as days resulted in greater discounting compared to the calendar method. The hyperboloid model fit best compared to the hyperbola and exponential models. How time is framed may alter how participants attend to the delays as well as how the delayed outcome is valued. Altering how time is framed may serve to improve adherence to goals with delayed outcomes. © Society for the Experimental Analysis of Behavior.

  17. Does Bilingualism Delay the Development of Dementia?

    OpenAIRE

    Amy L Atkinson

    2016-01-01

    It has been suggested that bilingualism (where individuals speak two languages) may delay the development of dementia. However, much of the research is inconclusive. Some researchers have reported that bilingualism delays the onset and diagnosis of dementia, whilst other studies have found weak or even detrimental effects. This paper reviews a series of nine empirical studies, published up until March 2016, which investigated whether bilingualism significantly delays the onset of dementia. Th...

  18. Stabilizing embedology: Geometry-preserving delay-coordinate maps

    Science.gov (United States)

    Eftekhari, Armin; Yap, Han Lun; Wakin, Michael B.; Rozell, Christopher J.

    2018-02-01

    Delay-coordinate mapping is an effective and widely used technique for reconstructing and analyzing the dynamics of a nonlinear system based on time-series outputs. The efficacy of delay-coordinate mapping has long been supported by Takens' embedding theorem, which guarantees that delay-coordinate maps use the time-series output to provide a reconstruction of the hidden state space that is a one-to-one embedding of the system's attractor. While this topological guarantee ensures that distinct points in the reconstruction correspond to distinct points in the original state space, it does not characterize the quality of this embedding or illuminate how the specific parameters affect the reconstruction. In this paper, we extend Takens' result by establishing conditions under which delay-coordinate mapping is guaranteed to provide a stable embedding of a system's attractor. Beyond only preserving the attractor topology, a stable embedding preserves the attractor geometry by ensuring that distances between points in the state space are approximately preserved. In particular, we find that delay-coordinate mapping stably embeds an attractor of a dynamical system if the stable rank of the system is large enough to be proportional to the dimension of the attractor. The stable rank reflects the relation between the sampling interval and the number of delays in delay-coordinate mapping. Our theoretical findings give guidance to choosing system parameters, echoing the tradeoff between irrelevancy and redundancy that has been heuristically investigated in the literature. Our initial result is stated for attractors that are smooth submanifolds of Euclidean space, with extensions provided for the case of strange attractors.

  19. H-infty Control of systems with multiple i/o delays

    NARCIS (Netherlands)

    Agoes Ariffin Moelja, A.A.; Meinsma, Gjerrit; Mirkin, Leonid

    2003-01-01

    In this paper the standard (four-block) H-infty control problem for systems with multiple i/o delays in the feedback loop is studied. The central idea is to see the multiple delay operator as a special series connection of elementary delay operators, called the adobe delay operators. The adobe delay

  20. Algebraic entropy for differential-delay equations

    OpenAIRE

    Viallet, Claude M.

    2014-01-01

    We extend the definition of algebraic entropy to a class of differential-delay equations. The vanishing of the entropy, as a structural property of an equation, signals its integrability. We suggest a simple way to produce differential-delay equations with vanishing entropy from known integrable differential-difference equations.

  1. Neural processes mediating the preparation and release of focal motor output are suppressed or absent during imagined movement

    Science.gov (United States)

    Eagles, Jeremy S.; Carlsen, Anthony N.

    2016-01-01

    Movements that are executed or imagined activate a similar subset of cortical regions, but the extent to which this activity represents functionally equivalent neural processes is unclear. During preparation for an executed movement, presentation of a startling acoustic stimulus (SAS) evokes a premature release of the planned movement with the spatial and temporal features of the tasks essentially intact. If imagined movement incorporates the same preparatory processes as executed movement, then a SAS should release the planned movement during preparation. This hypothesis was tested using an instructed-delay cueing paradigm during which subjects were required to rapidly release a handheld weight while maintaining the posture of the arm or to perform first-person imagery of the same task while holding the weight. In a subset of trials, a SAS was presented at 1500, 500, or 200 ms prior to the release cue. Task-appropriate preparation during executed and imagined movements was confirmed by electroencephalographic recording of a contingent negative variation waveform. During preparation for executed movement, a SAS often resulted in premature release of the weight with the probability of release progressively increasing from 24 % at −1500 ms to 80 % at −200 ms. In contrast, the SAS rarely (movement. However, the SAS frequently evoked the planned postural response (suppression of bicep brachii muscle activity) irrespective of the task or timing of stimulation (even during periods of postural hold without preparation). These findings provide evidence that neural processes mediating the preparation and release of the focal motor task (release of the weight) are markedly attenuated or absent during imagined movement and that postural and focal components of the task are prepared independently. PMID:25744055

  2. Transmission delays in hardware clock synchronization

    Science.gov (United States)

    Shin, Kang G.; Ramanathan, P.

    1988-01-01

    Various methods, both with software and hardware, have been proposed to synchronize a set of physical clocks in a system. Software methods are very flexible and economical but suffer an excessive time overhead, whereas hardware methods require no time overhead but are unable to handle transmission delays in clock signals. The effects of nonzero transmission delays in synchronization have been studied extensively in the communication area in the absence of malicious or Byzantine faults. The authors show that it is easy to incorporate the ideas from the communication area into the existing hardware clock synchronization algorithms to take into account the presence of both malicious faults and nonzero transmission delays.

  3. Generation of wideband chaos with suppressed time-delay signature by delayed self-interference.

    Science.gov (United States)

    Wang, Anbang; Yang, Yibiao; Wang, Bingjie; Zhang, Beibei; Li, Lei; Wang, Yuncai

    2013-04-08

    We demonstrate experimentally and numerically a method using the incoherent delayed self-interference (DSI) of chaotic light from a semiconductor laser with optical feedback to generate wideband chaotic signal. The results show that, the DSI can eliminate the domination of laser relaxation oscillation existing in the chaotic laser light and therefore flatten and widen the power spectrum. Furthermore, the DSI depresses the time-delay signature induced by external cavity modes and improves the symmetry of probability distribution by more than one magnitude. We also experimentally show that this DSI signal is beneficial to the random number generation.

  4. Intragastric Gelation of Heated Soy Protein Isolate-Alginate Mixtures and Its Effect on Sucrose Release.

    Science.gov (United States)

    Huang, Zhaozhi; Gruen, Ingolf; Vardhanabhuti, Bongkosh

    2018-06-15

    The goal of our study was to investigate the effect of alginate on in vitro gastric digestion and sucrose release of soy protein isolate (SPI) in model beverages. Model beverages containing 5% w/w SPI, 0% to 0.20% w/w alginate, and 10% w/w sucrose were prepared by heating the mixtures at 85 °C for 30 min at pH 6.0 or 7.0. Characterizations of beverages included determination of zeta potential, particle size and rheological properties. Digestion patterns and sucrose release profiles were determined during 2 hr in vitro gastric digestion using SDS-PAGE and HPLC analysis, respectively. Increasing alginate concentration led to increased negative surface charge, particle size, as well as viscosity and pseudoplastic behavior; however, no phase separation was observed. SPI beverages formed intragastric gel during in vitro gastric digestion when the formulations contained alginate or at pH 6.0 without alginate. Formation of the intragastric gel led to delayed protein digestion and release of sucrose. Higher resistance to digestion and a slower sucrose release rate were exhibited at increased alginate concentration, and to a lesser extent, at pH 6.0. This suggests that electrostatic interaction between SPI and alginate that occurred when the beverages were under gastric condition could be responsible for the intragastric gelation. These results could potentially lead to the formulation of SPI beverages with functionality to lower postprandial glycemic response. The results could be used to design beverages or semi solid food products with altered digestion properties and lowered or slower glucose release. © 2018 Institute of Food Technologists®.

  5. Delay Bound: Fractal Traffic Passes through Network Servers

    Directory of Open Access Journals (Sweden)

    Ming Li

    2013-01-01

    Full Text Available Delay analysis plays a role in real-time systems in computer communication networks. This paper gives our results in the aspect of delay analysis of fractal traffic passing through servers. There are three contributions presented in this paper. First, we will explain the reasons why conventional theory of queuing systems ceases in the general sense when arrival traffic is fractal. Then, we will propose a concise method of delay computation for hard real-time systems as shown in this paper. Finally, the delay computation of fractal traffic passing through severs is presented.

  6. Kainate-enhanced release of D-(3H)aspartate from cerebral cortex and striatum: reversal by baclofen and pentobarbital

    Energy Technology Data Exchange (ETDEWEB)

    Potashner, S.J.; Gerard, D.

    1983-06-01

    A study was made of the actions of the excitant neurotoxin, kainic acid, on the uptake and the release of D-(2,3-3H)aspartate (D-ASP) in slices of guinea pig cerebral neocortex and striatum. The slices took up D-ASP, reaching concentrations of the amino acid in the tissue which were 14-23 times that in the medium. Subsequently, electrical stimulation of the slices evoked a Ca2+-dependent release of a portion of the D-ASP. Kainic acid (10(-5)-10(-3) M) produced a dose-dependent inhibition of D-ASP uptake. The electrically evoked release of D-ASP was increased 1.6-2.0 fold by 10(-5) and 10(-4)M kainic acid. The kainate-enlarged release was Ca2+-dependent. Dihydrokainic acid, an analogue of kainic acid with little excitatory or toxic action, did not increase D-ASP release but depressed D-ASP uptake. Attempts were made to block the action of kainic acid with baclofen and pentobarbital, compounds which depress the electrically evoked release of L-glutamate (L-GLU) and L-aspartate (L-ASP). Baclofen (4 X 10(-6)M), an antispastic drug, and pentobarbital (10(-4)M), an anesthetic agent, each inhibited the electrically evoked release of D-ASP and prevented the enhancement of the release above control levels usually produced by 10(-4)M kainic acid. It is proposed that 10(-5) and 10(-4)M kainic acid may enhance the synaptic release of L-GLU and L-ASP from neurons which use these amino acids as transmitters. This action is prevented by baclofen and pentobarbital. In view of the possibility that cell death in Huntington's disease could involve excessive depolarization of striatal and other cells by glutamate, baclofen might be effective in delaying the loss of neurons associated with this condition.

  7. Time-Delay Interferometry

    Directory of Open Access Journals (Sweden)

    Massimo Tinto

    2014-08-01

    Full Text Available Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI. This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

  8. Delay-Dependent Stability Criteria of Uncertain Periodic Switched Recurrent Neural Networks with Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Xing Yin

    2011-01-01

    uncertain periodic switched recurrent neural networks with time-varying delays. When uncertain discrete-time recurrent neural network is a periodic system, it is expressed as switched neural network for the finite switching state. Based on the switched quadratic Lyapunov functional approach (SQLF and free-weighting matrix approach (FWM, some linear matrix inequality criteria are found to guarantee the delay-dependent asymptotical stability of these systems. Two examples illustrate the exactness of the proposed criteria.

  9. Outer synchronization of complex networks with internal delay and coupling delay via aperiodically intermittent pinning control

    Science.gov (United States)

    Zhang, Chuan; Wang, Xingyuan; Wang, Chunpeng; Xia, Zhiqiu

    This paper concerns the outer synchronization problem between two complex delayed networks via the method of aperiodically intermittent pinning control. Apart from previous works, internal delay and coupling delay are both involved in this model, and the designed intermittent controllers can be aperiodic. The main work in this paper can be summarized as follows: First, two cases of aperiodically intermittent control with constant gain and adaptive gain are implemented, respectively. The intermittent control and pinning control are combined to reduce consumptions further. Then, based on the Lyapunov stability theory, synchronization protocols are given by strict derivation. Especially, the designed controllers are indeed simple and valid in application of theory to practice. Finally, numerical examples put the proposed control methods to the test.

  10. State-dependent neutral delay equations from population dynamics.

    Science.gov (United States)

    Barbarossa, M V; Hadeler, K P; Kuttler, C

    2014-10-01

    A novel class of state-dependent delay equations is derived from the balance laws of age-structured population dynamics, assuming that birth rates and death rates, as functions of age, are piece-wise constant and that the length of the juvenile phase depends on the total adult population size. The resulting class of equations includes also neutral delay equations. All these equations are very different from the standard delay equations with state-dependent delay since the balance laws require non-linear correction factors. These equations can be written as systems for two variables consisting of an ordinary differential equation (ODE) and a generalized shift, a form suitable for numerical calculations. It is shown that the neutral equation (and the corresponding ODE--shift system) is a limiting case of a system of two standard delay equations.

  11. Early versus delayed hormonal treatment in locally advanced or asymptomatic metastatic prostatic cancer patient dilemma.

    Science.gov (United States)

    Prezioso, Domenico; Iacono, Fabrizio; Romeo, Giuseppe; Ruffo, Antonio; Russo, Nicola; Illiano, Ester

    2014-06-01

    The objective of this work is to compare the effectiveness of hormonal treatment (luteinizing hormone-releasing hormone agonists and/or antiandrogens) as an early or as a deferred intervention for patients with locally advanced prostate cancer (LAPC) and/or asymptomatic metastasis. Systematic review of trials published in 1950-2007. Sources included MEDLINE and bibliographies of retrieved articles. Eligible trials included adults with a history of LAPC who are not suitable for curative local treatment of prostate cancer. We retrieved 22 articles for detailed review, of which 8 met inclusion criteria. The Veterans Administration Cooperative Urological Research Group suggested that delaying hormonal therapy did not compromise overall survival and that many of the patients died of causes other than prostate cancer. In European Organisation for Research and Treatment of Cancer (EORTC) 30846 trial, the median survival for delayed endocrine treatment was 6.1 year, and for immediate treatment 7.6 year, the HR for survival on delayed versus immediate treatment was 1.23 (95 % CI 0.88-1.71), indicating a 23 % nonsignificant trend in favour of early treatment. In EORTC 30891, the immediate androgen deprivation resulted in a modest but statistically significant increase in overall survival. The protocol SAKK 08/88 showed the lack of any major advantage of immediate compared with deferred hormonal treatment regarding quality of life or overall survival. The early intervention with hormonal treatment for patients with LAPC provides important reductions in all-cause mortality, prostate cancer-specific mortality, overall progression, and distant progression compared with deferring their use until standard care has failed to halt the disease.

  12. Delayed traumatic intracranial hematoma

    International Nuclear Information System (INIS)

    Tomita, Hiroki

    1984-01-01

    CT was performed serially within 24 hours after head injury in 64 patients having Glasgow Coma Scale of 14 or less or cranial fracture shown on roentgenogram. Delayed traumatic extradural hematoma was observed within 7-12 hours after head injury in 6 cases (9.4%). This was prominent in the frontal and occipital regions (67%). Good recovery was seen in 83.3%. Delayed traumatic intracerebral hematoma was observed within 6-24 hours after head injury in 17 cases (26.6%). This higher incidence was related to contre coup injury. Conservative treatment was possible in 14 of the 17 patients (82.4%), showing good recovery in 70%. (Namekawa, K.)

  13. Learning monopolies with delayed feedback on price expectations

    Science.gov (United States)

    Matsumoto, Akio; Szidarovszky, Ferenc

    2015-11-01

    We call the intercept of the price function with the vertical axis the maximum price and the slope of the price function the marginal price. In this paper it is assumed that a monopolistic firm has full information about the marginal price and its own cost function but is uncertain on the maximum price. However, by repeated interaction with the market, the obtained price observations give a basis for an adaptive learning process of the maximum price. It is also assumed that the price observations have fixed delays, so the learning process can be described by a delayed differential equation. In the cases of one or two delays, the asymptotic behavior of the resulting dynamic process is examined, stability conditions are derived. Three main results are demonstrated in the two delay learning processes. First, it is possible to stabilize the equilibrium which is unstable in the one delay model. Second, complex dynamics involving chaos, which is impossible in the one delay model, can emerge. Third, alternations of stability and instability (i.e., stability switches) occur repeatedly.

  14. Global chaos synchronization with channel time-delay

    International Nuclear Information System (INIS)

    Jiang Guoping; Zheng Weixing; Chen Guanrong

    2004-01-01

    This paper addresses a practical issue in chaos synchronization where there is a time-delay in the receiver as compared with the transmitter. A new synchronization scheme and a general criterion for global chaos synchronization are proposed and developed from the approach of unidirectional linear error feedback coupling with time-delay. The chaotic Chua's circuit is used for illustration, where the coupling parameters are determined according to the criterion under which the global chaos synchronization of the time-delay coupled systems is achieved

  15. Diagnosis delay in Libyan female breast cancer.

    Science.gov (United States)

    Ermiah, Eramah; Abdalla, Fathi; Buhmeida, Abdelbaset; Larbesh, Entesar; Pyrhönen, Seppo; Collan, Yrjö

    2012-08-21

    To study the diagnosis delay and its impact on stage of disease among women with breast cancer on Libya. 200 women, aged 22 to 75 years with breast cancer diagnosed during 2008-2009 were interviewed about the period from the first symptoms to the final histological diagnosis of breast cancer. This period (diagnosis time) was categorized into 3 periods: 6 months. If diagnosis time was longer than 3 months, the diagnosis was considered delayed (diagnosis delay). Consultation time was the time taken to visit the general practitioner after the first symptoms. Retrospective preclinical and clinical data were collected on a form (questionnaire) during an interview with each patient and from medical records. The median of diagnosis time was 7.5 months. Only 30.0% of patients were diagnosed within 3 months after symptoms. 14% of patients were diagnosed within 3-6 months and 56% within a period longer than 6 months. A number of factors predicted diagnosis delay: Symptoms were not considered serious in 27% of patients. Alternative therapy (therapy not associated with cancer) was applied in 13.0% of the patients. Fear and shame prevented the visit to the doctor in 10% and 4.5% of patients, respectively. Inappropriate reassurance that the lump was benign was an important reason for prolongation of the diagnosis time. Diagnosis delay was associated with initial breast symptom(s) that did not include a lump (p diagnosis, the clinical stage distribution was as follows: 9.0% stage I, 25.5% stage II, 54.0% stage III and 11.5% stage IV.Diagnosis delay was associated with bigger tumour size (p Diagnosis delay is very serious problem in Libya. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer awareness and training of general practitioners to reduce breast cancer mortality by promoting early detection. The treatment guidelines should pay more attention to the early phases of breast

  16. Diagnosis delay in Libyan female breast cancer

    Directory of Open Access Journals (Sweden)

    Ermiah Eramah

    2012-08-01

    Full Text Available Abstract Aims To study the diagnosis delay and its impact on stage of disease among women with breast cancer on Libya. Methods 200 women, aged 22 to 75 years with breast cancer diagnosed during 2008–2009 were interviewed about the period from the first symptoms to the final histological diagnosis of breast cancer. This period (diagnosis time was categorized into 3 periods: 6 months. If diagnosis time was longer than 3 months, the diagnosis was considered delayed (diagnosis delay. Consultation time was the time taken to visit the general practitioner after the first symptoms. Retrospective preclinical and clinical data were collected on a form (questionnaire during an interview with each patient and from medical records. Results The median of diagnosis time was 7.5 months. Only 30.0% of patients were diagnosed within 3 months after symptoms. 14% of patients were diagnosed within 3–6 months and 56% within a period longer than 6 months. A number of factors predicted diagnosis delay: Symptoms were not considered serious in 27% of patients. Alternative therapy (therapy not associated with cancer was applied in 13.0% of the patients. Fear and shame prevented the visit to the doctor in 10% and 4.5% of patients, respectively. Inappropriate reassurance that the lump was benign was an important reason for prolongation of the diagnosis time. Diagnosis delay was associated with initial breast symptom(s that did not include a lump (p  Diagnosis delay was associated with bigger tumour size (p Conclusions Diagnosis delay is very serious problem in Libya. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer awareness and training of general practitioners to reduce breast cancer mortality by promoting early detection. The treatment guidelines should pay more attention to the early phases of breast cancer. Especially, guidelines for good practices in managing

  17. Lag synchronization of chaotic systems with time-delayed linear ...

    Indian Academy of Sciences (India)

    delayed linear terms via impulsive control is investigated. Based on the stability theory of impulsive delayed differen- tial equations, some sufficient conditions are obtained guaranteeing the synchronized behaviours between two delayed chaotic ...

  18. Hippocampus, delay discounting, and vicarious trial-and-error.

    Science.gov (United States)

    Bett, David; Murdoch, Lauren H; Wood, Emma R; Dudchenko, Paul A

    2015-05-01

    In decision-making, an immediate reward is usually preferred to a delayed reward, even if the latter is larger. We tested whether the hippocampus is necessary for this form of temporal discounting, and for vicarious trial-and-error at the decision point. Rats were trained on a recently developed, adjustable delay-discounting task (Papale et al. (2012) Cogn Affect Behav Neurosci 12:513-526), which featured a choice between a small, nearly immediate reward, and a larger, delayed reward. Rats then received either hippocampus or sham lesions. Animals with hippocampus lesions adjusted the delay for the larger reward to a level similar to that of sham-lesioned animals, suggesting a similar valuation capacity. However, the hippocampus lesion group spent significantly longer investigating the small and large rewards in the first part of the sessions, and were less sensitive to changes in the amount of reward in the large reward maze arm. Both sham- and hippocampus-lesioned rats showed a greater amount of vicarious trial-and-error on trials in which the delay was adjusted. In a nonadjusting version of the delay discounting task, animals with hippocampus lesions showed more variability in their preference for a larger reward that was delayed by 10 s compared with sham-lesioned animals. To verify the lesion behaviorally, rat were subsequently trained on a water maze task, and rats with hippocampus lesions were significantly impaired compared with sham-lesioned animals. The findings on the delay discounting tasks suggest that damage to the hippocampus may impair the detection of reward magnitude. © 2014 Wiley Periodicals, Inc.

  19. A stability criterion for HNFDE with non-uniform delays

    International Nuclear Information System (INIS)

    Liu Xingwen; Zhong Shouming; Zhang Fengli

    2005-01-01

    Stability of functional differential equations (FDE) is an increasingly important problem in both science and engineering. Delays, whether uniform or non-uniform, play an important role in the dynamics of a system. Since non-uniform delay is more general and less focused than uniform delay, this paper concentrates on the stability of high-order neutral functional differential equations (HNFDE) with non-uniform delay, and proposes a sufficient condition for it. This result may be widely helpful, thanks to the frequent emergence of a HNFDE with non-uniform delay in various fields. Its effectiveness is illustrated by some examples

  20. Delay time and Hartman effect in strain engineered graphene

    International Nuclear Information System (INIS)

    Chen, Xi; Deng, Zhi-Yong; Ban, Yue

    2014-01-01

    Tunneling times, including group delay and dwell time, are studied for massless Dirac electrons transmitting through a one-dimensional barrier in strain-engineered graphene. The Hartman effect, the independence of group delay on barrier length, is induced by the strain effect, and associated with the transmission gap and the evanescent mode. The influence of barrier height/length and strain modulus/direction on the group delay is also discussed, which provides the flexibility to control the group delay with applications in graphene-based devices. The relationship between group delay and dwell time is finally derived to clarify the nature of the Hartman effect

  1. Hydraulic running and release tool with mechanical emergency release

    International Nuclear Information System (INIS)

    Baker, S.F.

    1991-01-01

    This patent describes a setting tool for connection in a well string to position a tubular member in a well bore. It comprises: a mandrel adapted to be connected to the well string; an outer sleeve surrounding the mandrel and releasably secured thereto; a latch nut releasably connected to the outer sleeve; piston means sealingly engaging the mandrel; shear means releasably securing the piston to the latch nut to maintain the latch nut releasably connected to the tubular member; the mandrel having port means for conducting fluid pressure from the well string to release the piston means from and the latch nut; cooperating engageable surfaces on the piston and latch nut to reengage them together after the piston moves a predetermined longitudinal distance relative to the latch nut; and additional cooperating engageable surfaces on the latch nut and the outer sleeve which are engageable when the piston and engaged latch nut are moved a predetermined additional longitudinal distance by fluid pressure to secure the engaged piston and latch nut with the outer sleeve for retrieval along with the mandrel from the well bore

  2. Improved delay-dependent globally asymptotic stability of delayed uncertain recurrent neural networks with Markovian jumping parameters

    International Nuclear Information System (INIS)

    Yan, Ji; Bao-Tong, Cui

    2010-01-01

    In this paper, we have improved delay-dependent stability criteria for recurrent neural networks with a delay varying over a range and Markovian jumping parameters. The criteria improve over some previous ones in that they have fewer matrix variables yet less conservatism. In addition, a numerical example is provided to illustrate the applicability of the result using the linear matrix inequality toolbox in MATLAB. (general)

  3. Delay-Dependent Stability Criterion for Bidirectional Associative Memory Neural Networks with Interval Time-Varying Delays

    Science.gov (United States)

    Park, Ju H.; Kwon, O. M.

    In the letter, the global asymptotic stability of bidirectional associative memory (BAM) neural networks with delays is investigated. The delay is assumed to be time-varying and belongs to a given interval. A novel stability criterion for the stability is presented based on the Lyapunov method. The criterion is represented in terms of linear matrix inequality (LMI), which can be solved easily by various optimization algorithms. Two numerical examples are illustrated to show the effectiveness of our new result.

  4. Exponential stability for stochastic delayed recurrent neural networks with mixed time-varying delays and impulses: the continuous-time case

    International Nuclear Information System (INIS)

    Karthik Raja, U; Leelamani, A; Raja, R; Samidurai, R

    2013-01-01

    In this paper, the exponential stability for a class of stochastic neural networks with time-varying delays and impulsive effects is considered. By constructing suitable Lyapunov functionals and by using the linear matrix inequality optimization approach, we obtain sufficient delay-dependent criteria to ensure the exponential stability of stochastic neural networks with time-varying delays and impulses. Two numerical examples with simulation results are provided to illustrate the effectiveness of the obtained results over those already existing in the literature. (paper)

  5. Generalized Synchronization of Time-Delayed Discrete Systems

    International Nuclear Information System (INIS)

    Jing Jianyi; Min Lequan

    2009-01-01

    This paper establishes two theorems for two time-delayed (chaotic) discrete systems to achieve time-delayed generalized synchronization (TDGS). These two theorems uncover the general forms of two TDGS systems via a prescribed transformation. As examples, we convert the Lorenz three-dimensional chaotic map to an equal time-delayed system as the driving system, and construct the TDGS driven systems according to the Theorems 1 and 2. Numerical simulations demonstrate the effectiveness of the proposed theorems. (interdisciplinary physics and related areas of science and technology)

  6. Global robust stability of neural networks with multiple discrete delays and distributed delays

    International Nuclear Information System (INIS)

    Gao Ming; Cui Baotong

    2009-01-01

    The problem of global robust stability is investigated for a class of uncertain neural networks with both multiple discrete time-varying delays and distributed time-varying delays. The uncertainties are assumed to be of norm-bounded form and the activation functions are supposed to be bounded and globally Lipschitz continuous. Based on the Lyapunov stability theory and linear matrix inequality technique, some robust stability conditions guaranteeing the global robust convergence of the equilibrium point are derived. The proposed LMI-based criteria are computationally efficient as they can be easily checked by using recently developed algorithms in solving LMIs. Two examples are given to show the effectiveness of the proposed results.

  7. Simulation of activation and propagation delay during tripolar neural stimulation

    NARCIS (Netherlands)

    Goodall, E.V.; Goodall, Eleanor V.; Kosterman, L. Martin; Struijk, Johannes J.; Struijk, J.J.; Holsheimer, J.

    1993-01-01

    Computer simulations were perfonned to investigate the influence of stimulus amplitude on cathodal activation delay, propagation delay and blocking during stimulation with a bipolar cuff electrode. Activation and propagation delays were combined in a total delay term which was minimized between the

  8. Delayed polymorphonuclear leukocyte infiltration is an important component of Thalassophryne maculosa venom pathogenesis.

    Science.gov (United States)

    Pareja-Santos, Alessandra; Oliveira Souza, Valdênia Maria; Bruni, Fernanda M; Sosa-Rosales, Josefina Ines; Lopes-Ferreira, Mônica; Lima, Carla

    2008-07-01

    Thalassophryne maculosa fish envenomation is characterized by severe pain, dizziness, fever, edema and necrosis. Here, the dynamic of cellular influx, activation status of phagocytic cells, and inflammatory modulator production in the acute inflammatory response to T. maculosa venom was studied using an experimental model. Leukocyte counting was performed (2 h to 21 days) after venom injection in BALB/c mice footpads. Our results showed an uncommon leukocyte migration kinetic after venom injection, with early mononuclear cell recruitment followed by elevated and delayed neutrophil influx. The pattern of chemokine expression is consistent with the delay in neutrophil recruitment to the footpad: T. maculosa venom stimulated an early production of IL-1beta, IL-6, and MCP-1, but was unable to induce an effective early TNF-alpha and KC release. Complementary to these observations, we detected a marked increase in soluble KC and TNF-alpha in footpad at 7 days post-venom injection when a prominent influx of neutrophils was also detected. In addition, we demonstrated that bone marrow-derived macrophages and dendritic cells were strongly stimulated by the venom, showing up-regulated ability to capture FITC-dextran. Thus, the reduced levels of KC and TNF-alpha in footpad of mice concomitant with a defective accumulation of neutrophils at earlier times provide an important clue to uncovering the mechanism by which T. maculosa venom regulates neutrophil movement.

  9. Delayed neutrons in liquid metal spallation targets

    International Nuclear Information System (INIS)

    Ridikas, D.; Bokov, P.; David, J.C.; Dore, D.; Giacri, M.L.; Van Lauwe, A.; Plukiene, R.; Plukis, A.; Ignatiev, S.; Pankratov, D.

    2003-01-01

    The next generation spallation neutron sources, neutrino factories or RIB production facilities currently being designed and constructed around the world will increase the average proton beam power on target by a few orders of magnitude. Increased proton beam power results in target thermal hydraulic issues leading to new target designs, very often based on flowing liquid metal targets such as Hg, Pb, Pb-Bi. Radioactive nuclides produced in liquid metal targets are transported into hot cells, past electronics, into pumps with radiation sensitive components, etc. Besides the considerable amount of photon activity in the irradiated liquid metal, a significant amount of the delayed neutron precursor activity can be accumulated in the target fluid. The transit time from the front of a liquid metal target into areas, where delayed neutrons may be important, can be as short as a few seconds, well within one half-life of many delayed neutron precursors. Therefore, it is necessary to evaluate the total neutron flux (including delayed neutrons) as a function of time and determine if delayed neutrons contribute significantly to the dose rate. In this study the multi-particle transport code MCNPX combined with the material evolution program CINDER'90 will be used to evaluate the delayed neutron flux and spectra. The following scientific issues will be addressed in this paper: - Modeling of a typical geometry of the liquid metal spallation target; - Predictions of the prompt neutron fluxes, fission fragment and spallation product distributions; - Comparison of the above parameters with existing experimental data; - Time-dependent calculations of delayed neutron precursors; - Neutron flux estimates due to the prompt and delayed neutron emission; - Proposal of an experimental program to measure delayed neutron spectra from high energy spallation-fission reactions. The results of this study should be directly applicable in the design study of the European MegaPie (1 MW

  10. Time-delayed autosynchronous swarm control.

    Science.gov (United States)

    Biggs, James D; Bennet, Derek J; Dadzie, S Kokou

    2012-01-01

    In this paper a general Morse potential model of self-propelling particles is considered in the presence of a time-delayed term and a spring potential. It is shown that the emergent swarm behavior is dependent on the delay term and weights of the time-delayed function, which can be set to induce a stationary swarm, a rotating swarm with uniform translation, and a rotating swarm with a stationary center of mass. An analysis of the mean field equations shows that without a spring potential the motion of the center of mass is determined explicitly by a multivalued function. For a nonzero spring potential the swarm converges to a vortex formation about a stationary center of mass, except at discrete bifurcation points where the center of mass will periodically trace an ellipse. The analytical results defining the behavior of the center of mass are shown to correspond with the numerical swarm simulations.

  11. Theory of attosecond delays in molecular photoionization.

    Science.gov (United States)

    Baykusheva, Denitsa; Wörner, Hans Jakob

    2017-03-28

    We present a theoretical formalism for the calculation of attosecond delays in molecular photoionization. It is shown how delays relevant to one-photon-ionization, also known as Eisenbud-Wigner-Smith delays, can be obtained from the complex dipole matrix elements provided by molecular quantum scattering theory. These results are used to derive formulae for the delays measured by two-photon attosecond interferometry based on an attosecond pulse train and a dressing femtosecond infrared pulse. These effective delays are first expressed in the molecular frame where maximal information about the molecular photoionization dynamics is available. The effects of averaging over the emission direction of the electron and the molecular orientation are introduced analytically. We illustrate this general formalism for the case of two polyatomic molecules. N 2 O serves as an example of a polar linear molecule characterized by complex photoionization dynamics resulting from the presence of molecular shape resonances. H 2 O illustrates the case of a non-linear molecule with comparably simple photoionization dynamics resulting from a flat continuum. Our theory establishes the foundation for interpreting measurements of the photoionization dynamics of all molecules by attosecond metrology.

  12. Television viewing associates with delayed language development.

    Science.gov (United States)

    Chonchaiya, Weerasak; Pruksananonda, Chandhita

    2008-07-01

    To identify impact of television viewing on language development. The case-control study included 56 new patients with language delay and 110 normal children, aged 15-48 months. Language delay was diagnosed by reviewing language milestones and Denver-II. Television viewing variables and child/parental characteristics between both groups were interviewed. The data were analyzed by ANOVA and chi-square test. Adjusted odds ratios and 95% confidence intervals were calculated from multivariate logistic regression model. Forty-six boys and 10 girls; mean [+/-SD] age, 2.11+/-0.47 years of the case group and 59 boys and 51 girls; mean [+/-SD] age, 2.23+/-0.80 years of the control group were enrolled. Children who had language delay usually started watching television earlier at age 7.22+/-5.52 months vs. 11.92+/-5.86 months, p-valuetelevision than normal children (3.05+/-1.90 h/day vs. 1.85+/-1.18 h/day; p-valuetelevision attelevision>2 h/day were approximately six times more likely to have language delays. There is a relationship between early onset and high frequency of TV viewing and language delay.

  13. Characteristics of hypertrophic cardiomyopathy on delayed contrast-enhanced MRI

    International Nuclear Information System (INIS)

    Yan Chaowu; Zhao Shihua; Li Hua; Jiang Shiliang; Lu Minjie; Zhang Yan; Wei Yunqing; Ling Jian; Fang Wei

    2010-01-01

    Objective: To analyze the characteristics of hypertrophic cardiomyopathy (HCM) on delayed contrast-enhanced cardiac magnetic resonance imaging (CMRI). Methods: All patients underwent delayed contrast-enhanced CMRI. The left ventricle was divided into 9 segments to assess the location, extent and function of the hypertrophic segments. The t test was applied for the statistics. Results: Of 154 patients, delayed enhancement of' hypertrophic segment was found in 95 cases and non-delayed enhancement in 59 cases. The thickness and number of hypertrophic segment in patients with delayed enhancement were larger than those with non-delayed enhancement [(24.8±5.5) mm vs (20.4± 3.8) mm, t=3.82, P<0.05; (3.3±1.9) vs (2.4±1.7), t=2.26, P<0.05], and the age was younger [(46.0±15.2) years vs (55.0±11.9) years, t=-3.67, P<0.05]. The diffuse enhancement was found in 62 patients, and confluent enhancement in 33 patients. Confluent enhancement was found in all 14 patients after the alcohol ablation procedure. Conclusion: The age, thickness and number of hypertrophic segments in patients with delayed enhancement are different from those with non-delayed enhancement. (authors)

  14. Does Bilingualism Delay the Development of Dementia?

    Directory of Open Access Journals (Sweden)

    Amy L Atkinson

    2016-08-01

    Full Text Available It has been suggested that bilingualism (where individuals speak two languages may delay the development of dementia. However, much of the research is inconclusive. Some researchers have reported that bilingualism delays the onset and diagnosis of dementia, whilst other studies have found weak or even detrimental effects. This paper reviews a series of nine empirical studies, published up until March 2016, which investigated whether bilingualism significantly delays the onset of dementia. The article also explores whether the inconsistent findings can be attributed to differences in study designs or the definitions of bilingualism used between studies. Based on current evidence, it appears that lifelong bilingualism, where individuals frequently use both languages, may be protective against dementia. However, becoming bilingual in adulthood or using the second language infrequently is unlikely to substantially delay onset of the disease.

  15. Spiking Activity of a LIF Neuron in Distributed Delay Framework

    Directory of Open Access Journals (Sweden)

    Saket Kumar Choudhary

    2016-06-01

    Full Text Available Evolution of membrane potential and spiking activity for a single leaky integrate-and-fire (LIF neuron in distributed delay framework (DDF is investigated. DDF provides a mechanism to incorporate memory element in terms of delay (kernel function into a single neuron models. This investigation includes LIF neuron model with two different kinds of delay kernel functions, namely, gamma distributed delay kernel function and hypo-exponential distributed delay kernel function. Evolution of membrane potential for considered models is studied in terms of stationary state probability distribution (SPD. Stationary state probability distribution of membrane potential (SPDV for considered neuron models are found asymptotically similar which is Gaussian distributed. In order to investigate the effect of membrane potential delay, rate code scheme for neuronal information processing is applied. Firing rate and Fano-factor for considered neuron models are calculated and standard LIF model is used for comparative study. It is noticed that distributed delay increases the spiking activity of a neuron. Increase in spiking activity of neuron in DDF is larger for hypo-exponential distributed delay function than gamma distributed delay function. Moreover, in case of hypo-exponential delay function, a LIF neuron generates spikes with Fano-factor less than 1.

  16. Large scientific releases

    International Nuclear Information System (INIS)

    Pongratz, M.B.

    1981-01-01

    The motivation for active experiments in space is considered, taking into account the use of active techniques to obtain a better understanding of the natural space environment, the utilization of the advantages of space as a laboratory to study fundamental plasma physics, and the employment of active techniques to determine the magnitude, degree, and consequences of artificial modification of the space environment. It is pointed out that mass-injection experiments in space plasmas began about twenty years ago with the Project Firefly releases. Attention is given to mass-release techniques and diagnostics, operational aspects of mass release active experiments, the active observation of mass release experiments, active perturbation mass release experiments, simulating an artificial modification of the space environment, and active experiments to study fundamental plasma physics

  17. Noise-sustained fluctuations in stochastic dynamics with a delay.

    Science.gov (United States)

    D'Odorico, Paolo; Laio, Francesco; Ridolfi, Luca

    2012-04-01

    Delayed responses to external drivers are ubiquitous in environmental, social, and biological processes. Delays may induce oscillations, Hopf bifurcations, and instabilities in deterministic systems even in the absence of nonlinearities. Despite recent advances in the study of delayed stochastic differential equations, the interaction of random drivers with delays remains poorly understood. In particular, it is unclear whether noise-induced behaviors may emerge from these interactions. Here we show that noise may enhance and sustain transient periodic oscillations inherent to deterministic delayed systems. We investigate the conditions conducive to the emergence and disappearance of these dynamics in a linear system in the presence of both additive and multiplicative noise.

  18. Stimulatory effects of neuronally released norepinephrine on renin release in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, Yasuo; Kawazoe, Shinka; Ichihara, Toshio; Shinyama, Hiroshi; Kageyama, Masaaki; Morimoto, Shiro (Osaka Univ. of Pharmaceutical Sciences (Japan))

    1988-10-01

    Extracellular high potassium inhibits renin release in vitro by increasing calcium concentrations in the juxtaglomerular cells. The authors found that the decreased response of renin release from rat kidney cortical slices in high potassium solution changed to a strikingly increased one in the presence of nifedipine at doses over 10{sup {minus}6} M. They then examined the stimulatory effect of extracellular high potassium in the presence of nifedipine on renin release. The enhancement of release was significantly suppressed either by propranolol or by metoprolol but not by prazosin. High potassium plus nifedipine-induced increase in renin release was markedly attenuated by renal denervation. The enhancing effect was not observed when the slices were incubated in calcium-free medium. Divalent cations such as Cd{sup 2+}, Co{sup 2+}, and Mn{sup 2+} blocked this enhancement in a concentration-dependent manner. High potassium elicited an increase in {sup 3}H efflux from the slices preloaded with ({sup 3}H)-norepinephrine. The increasing effect was not influenced by nifedipine but was abolished by the removal of extracellular calcium or by the addition of divalent cations. These observations suggest to us that the high potassium plus nifedipine-induced increase in renin release from the slices is mediated by norepinephrine derived from renal sympathetic nerves and that this neuronally released norepinephrine stimulates renin release via activation of {beta}-adrenoceptors.

  19. A continuous time Cournot duopoly with delays

    International Nuclear Information System (INIS)

    Gori, Luca; Guerrini, Luca; Sodini, Mauro

    2015-01-01

    This paper extends the classical repeated duopoly model with quantity-setting firms of Bischi et al. (1998) by assuming that production of goods is subject to some gestation lags but exchanges take place continuously in the market. The model is expressed in the form of differential equations with discrete delays. By using some recent mathematical techniques and numerical experiments, results show some dynamic phenomena that cannot be observed when delays are absent. In addition, depending on the extent of time delays and inertia, synchronisation failure can arise even in the event of homogeneous firms.

  20. Modeling Directional Selectivity Using Self-Organizing Delay-Aadaptation Maps

    OpenAIRE

    Tversky, Mr. Tal; Miikkulainen, Dr. Risto

    2002-01-01

    Using a delay adaptation learning rule, we model the activity-dependent development of directionally selective cells in the primary visual cortex. Based on input stimuli, a learning rule shifts delays to create synchronous arrival of spikes at cortical cells. As a result, delays become tuned creating a smooth cortical map of direction selectivity. This result demonstrates how delay adaption can serve as a powerful abstraction for modeling temporal learning in the brain.

  1. Delay-distribution-dependent H∞ state estimation for delayed neural networks with (x,v)-dependent noises and fading channels.

    Science.gov (United States)

    Sheng, Li; Wang, Zidong; Tian, Engang; Alsaadi, Fuad E

    2016-12-01

    This paper deals with the H ∞ state estimation problem for a class of discrete-time neural networks with stochastic delays subject to state- and disturbance-dependent noises (also called (x,v)-dependent noises) and fading channels. The time-varying stochastic delay takes values on certain intervals with known probability distributions. The system measurement is transmitted through fading channels described by the Rice fading model. The aim of the addressed problem is to design a state estimator such that the estimation performance is guaranteed in the mean-square sense against admissible stochastic time-delays, stochastic noises as well as stochastic fading signals. By employing the stochastic analysis approach combined with the Kronecker product, several delay-distribution-dependent conditions are derived to ensure that the error dynamics of the neuron states is stochastically stable with prescribed H ∞ performance. Finally, a numerical example is provided to illustrate the effectiveness of the obtained results. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Effects of delaying the operation of a nuclear power plant

    International Nuclear Information System (INIS)

    Hill, L.J.; Rainey, J.A.; Tepel, R.C.; Van Dyke, J.W.

    1983-12-01

    This report documents a study of an actual 24-month nuclear power plant licensing delay. A representative utility was chosen for examination. The research was oriented toward determination of the licensing delay's impact on the utility's operating results, ratepayers, and security issues. The methodology utilized to estimate those impacts involved the recursive interaction of a generation costing program to estimate replacement fuel costs and a financial regulatory model to concomitantly determine the impact on the utility, its ratepayers and security issues. The latter model was executed under six alternate scenarios: (1) no delay in the plant's operation; (2) a 24-month delay; (3) a 24-month delay but further assuming all replacement power was generated by coal-fired plants; (4) a 24-month delay assuming all replacement power from oil-fired plants; (5) no delay but assuming the capital cost of the plant was twice as large; and (6) a 24-month delay with the capital cost of the plant twice as large. Three primary conclusions were made. First, under all scenarios, a 24-month delay in operation of the plant has an adverse impact on the utility's internal generation of funds. Second, although electricity rates are not appreciably affected by the delay, the direction of electricity price changes is contingent on the source of fuel used for replacement power. Finally, a 24-month delay has an adverse impact on the indicators used to evaluate the financial soundness of the utility in all cases under consideration

  3. Delayed feedback control in quantum transport.

    Science.gov (United States)

    Emary, Clive

    2013-09-28

    Feedback control in quantum transport has been predicted to give rise to several interesting effects, among them quantum state stabilization and the realization of a mesoscopic Maxwell's daemon. These results were derived under the assumption that control operations on the system are affected instantaneously after the measurement of electronic jumps through it. In this contribution, I describe how to include a delay between detection and control operation in the master equation theory of feedback-controlled quantum transport. I investigate the consequences of delay for the state stabilization and Maxwell's daemon schemes. Furthermore, I describe how delay can be used as a tool to probe coherent oscillations of electrons within a transport system and how this formalism can be used to model finite detector bandwidth.

  4. $\\beta$-delayed fission in proton-rich nuclei in the lead region

    CERN Document Server

    AUTHOR|(CDS)2085005; Huyse, Mark; Popescu, Lucia

    Nuclear fission is the breakup of an atomic nucleus into two (sometimes three) fragments, thereby releasing a large amount of energy. Soon after its discovery in the late 1930’s, the gross properties of the fission phenomenon were explained by macroscopic nuclear models. Certain features however, such as asymmetric fission-fragment mass distributions in the actinide region, require the inclusion of microscopic effects. This interplay of the microscopic motion of individual nucleons on this macroscopic process is, until today, not yet fully understood. The phenomenon of fission has therefore been of recurring interest for both theoretical and experimental studies. This thesis work focuses on the $\\beta$-delayed fission ($\\beta$DF) process, an excellent tool to study low-energy fission of exotic nuclei, which was discovered in 1966 in the actinide region. In this two-step process, a precursor nucleus first undergoes $\\beta$-decay to an excited level in the daughter nucleus, which may subsequently fission. Rec...

  5. Lag synchronization of chaotic systems with time-delayed linear

    Indian Academy of Sciences (India)

    In this paper, the lag synchronization of chaotic systems with time-delayed linear terms via impulsive control is investigated. Based on the stability theory of impulsive delayed differential equations, some sufficient conditions are obtained guaranteeing the synchronized behaviours between two delayed chaotic systems.

  6. ATFM airborne delays without extra fuel consumption in wind conditions

    OpenAIRE

    Delgado, L.; Prats, X.

    2012-01-01

    Air Traffic Flow Management (ATFM) regulations, such as ground holdings, are often canceled before their initially planned ending time. The ground delays impact on the cost of recovering part of the delay if the regulation is canceled, as aircraft are still at the origin airport. In previous publications, the authors have suggested a speed reduction strategy to split the assigned ATFM delay between ground delay and airborne delay. By flying at the the minimum speed that g...

  7. Unconditionally stable difference methods for delay partial differential equations

    OpenAIRE

    Huang, Chengming; Vandewalle, Stefan

    2012-01-01

    This paper is concerned with the numerical solution of parabolic partial differential equations with time-delay. We focus in particular on the delay dependent stability analysis of difference methods that use a non-constrained mesh, i.e., the time step-size is not required to be a submultiple of the delay. We prove that the fully discrete system unconditionally preserves the delay dependent asymptotic stability of the linear test problem under consideration, when the following discretizati...

  8. Operational monitoring of the release behaviour of the AVR core

    International Nuclear Information System (INIS)

    Wawrzik, U.; Ivens, G.

    1985-01-01

    The AVR reactor has been used for the mass testing of spherical HTR fuel elements for more than 17 years. To date 14 fuel element types have been used, some of which differ considerably with reference to the heavy metal content, fuel coating and chemical fuel composition. The aim of the measurements at the reactor and of a comprehensive post-irradiation examination programme for fuel elements is to check and evaluate the behaviour of these fuel elements under real reactor conditions. This paper considers only those measurements which are of interest for reactor operation. The integral release behaviour of the fuel elements is continuously monitored by measuring the noble fission gas activity in the primary system. This value is directly determined by the heavy metal contamination. If any significant particle defects occur during operation, these are immediately indicated by a considerable increase in the noble gas activity. The integral release of the solid fission products is monitored by means of filter samples both in the hot and in the cold gas area; this examination, however, is performed intermittently and with a time delay. As these integral measurements only allow one to draw limited conclusions about the behaviour of single fuel element charges or types, they are supplemented by the systematic extraction of fuel elements. These elements are then subjected to standardized annealing tests (KFA) to determine the individual noble gas release, and to examinations of the fuel-free shell to establish the distribution of the solid fission products in it (AVR). The latter method, in particular, has proved to be practicable, as particle defects are detected at an early stadium. During operation to date, only one fuel element charge exhibited incipient particle defects shortly before reaching its final burnup. It was possible to limit the activity release by altering the charging strategy, which resulted in lower fuel element temperatures, and by systematically

  9. Myocardial delayed-enhancement CT: initial experience in children and young adults

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

    2017-10-15

    Clinical utility of myocardial delayed enhancement CT has not been reported in children and young adults. To describe initial experience of myocardial delayed enhancement CT regarding image quality, radiation dose and identification of myocardial lesions in children and young adults. Between August 2013 and November 2016, 29 consecutive children and young adults (median age 16 months) with suspected coronary artery or myocardial abnormality underwent arterial- and delayed-phase cardiac CT at our institution. We measured CT densities in normal myocardium, left ventricular cavity, and arterial and delayed hypo-enhancing and delayed hyperenhancing myocardial lesions. We then compared the extent of delayed hyperenhancing lesions with delayed-enhancement MRI or thallium single-photon emission CT. Normal myocardium and left ventricular cavity showed significantly higher CT numbers on arterial-phase CT than on delayed-phase CT (t-test, P<0.0001). Contrast-to-noise ratios of the arterial and delayed hypo-enhancing and delayed hyperenhancing lesions on CT were 26.7, 17.6 and 18.7, respectively. Delayed-phase CT findings were equivalent to those of delayed-enhancement MRI in all cases (7/7) and to those of thallium single-photon emission CT in 70% (7/10). Myocardial delayed-enhancement CT can be added to evaluate myocardial lesions in select children and young adults with suspected coronary artery or myocardial abnormality. (orig.)

  10. Myocardial delayed-enhancement CT: initial experience in children and young adults

    International Nuclear Information System (INIS)

    Goo, Hyun Woo

    2017-01-01

    Clinical utility of myocardial delayed enhancement CT has not been reported in children and young adults. To describe initial experience of myocardial delayed enhancement CT regarding image quality, radiation dose and identification of myocardial lesions in children and young adults. Between August 2013 and November 2016, 29 consecutive children and young adults (median age 16 months) with suspected coronary artery or myocardial abnormality underwent arterial- and delayed-phase cardiac CT at our institution. We measured CT densities in normal myocardium, left ventricular cavity, and arterial and delayed hypo-enhancing and delayed hyperenhancing myocardial lesions. We then compared the extent of delayed hyperenhancing lesions with delayed-enhancement MRI or thallium single-photon emission CT. Normal myocardium and left ventricular cavity showed significantly higher CT numbers on arterial-phase CT than on delayed-phase CT (t-test, P<0.0001). Contrast-to-noise ratios of the arterial and delayed hypo-enhancing and delayed hyperenhancing lesions on CT were 26.7, 17.6 and 18.7, respectively. Delayed-phase CT findings were equivalent to those of delayed-enhancement MRI in all cases (7/7) and to those of thallium single-photon emission CT in 70% (7/10). Myocardial delayed-enhancement CT can be added to evaluate myocardial lesions in select children and young adults with suspected coronary artery or myocardial abnormality. (orig.)

  11. Moments of the Wigner delay times

    International Nuclear Information System (INIS)

    Berkolaiko, Gregory; Kuipers, Jack

    2010-01-01

    The Wigner time delay is a measure of the time spent by a particle inside the scattering region of an open system. For chaotic systems, the statistics of the individual delay times (whose average is the Wigner time delay) are thought to be well described by random matrix theory. Here we present a semiclassical derivation showing the validity of random matrix results. In order to simplify the semiclassical treatment, we express the moments of the delay times in terms of correlation functions of scattering matrices at different energies. In the semiclassical approximation, the elements of the scattering matrix are given in terms of the classical scattering trajectories, requiring one to study correlations between sets of such trajectories. We describe the structure of correlated sets of trajectories and formulate the rules for their evaluation to the leading order in inverse channel number. This allows us to derive a polynomial equation satisfied by the generating function of the moments. Along with showing the agreement of our semiclassical results with the moments predicted by random matrix theory, we infer that the scattering matrix is unitary to all orders in the semiclassical approximation.

  12. Beta delayed particle emission in light nuclei

    International Nuclear Information System (INIS)

    Riisager, K.; Gabelmann, H.

    1991-01-01

    A short discussion of theoretical treatments of beta delayed particle emission is followed by a presentation of data on the newly found beta delayed deuteron decay of 6 He. This decay cannot be described properly with existing theories. (author) 8 refs.; 3 figs

  13. Heterogeneity of time delays determines synchronization of coupled oscillators.

    Science.gov (United States)

    Petkoski, Spase; Spiegler, Andreas; Proix, Timothée; Aram, Parham; Temprado, Jean-Jacques; Jirsa, Viktor K

    2016-07-01

    Network couplings of oscillatory large-scale systems, such as the brain, have a space-time structure composed of connection strengths and signal transmission delays. We provide a theoretical framework, which allows treating the spatial distribution of time delays with regard to synchronization, by decomposing it into patterns and therefore reducing the stability analysis into the tractable problem of a finite set of delay-coupled differential equations. We analyze delay-structured networks of phase oscillators and we find that, depending on the heterogeneity of the delays, the oscillators group in phase-shifted, anti-phase, steady, and non-stationary clusters, and analytically compute their stability boundaries. These results find direct application in the study of brain oscillations.

  14. Periodic Solutions of a System of Delay Differential Equations for a Small Delay

    Directory of Open Access Journals (Sweden)

    Adu A.M. Wasike

    2002-06-01

    Full Text Available We prove the existence of an asymptotically stable periodic solution of a system of delay differential equations with a small time delay t > 0. To achieve this, we transform the system of equations into a system of perturbed ordinary differential equations and then use perturbation results to show the existence of an asymptotically stable periodic solution. This approach is contingent on the fact that the system of equations with t = 0 has a stable limit cycle. We also provide a comparative study of the solutions of the original system and the perturbed system.  This comparison lays the ground for proving the existence of periodic solutions of the original system by Schauder's fixed point theorem.

  15. Flight delay performance at Hartsfield-Jackson Atlanta International Airport

    Directory of Open Access Journals (Sweden)

    Grigoriy Yablonsky

    2014-01-01

    Full Text Available Purpose: The main objective of this paper is to determine the annual cyclical flight delays at Hartsfield-Jackson Atlanta International Airport. Then using other data such as annual precipitation, passenger and aircraft traffic volumes and other factors, we attempted to correlate these factors with overall delays. These data could assist airport management in predicting periods of flight delay.Design/methodology/approach: Data were taken and analyzed from the data base “Research and Innovation Technology Administration” (RITA for the years 2005-2011 for Hartsfield-Jackson Atlanta International Airport. The data included 2.8 million flights originating and departing from this airport. Data were also gathered from the National Oceanic and Atmospheric Administration (NOAA showing precipitation. Additional data were gathered from the FAA regarding delay causes, number and types of delays and changes to the infrastructure of ATL airportFindings: There is a repeatable annual pattern of delays at ATL that can be modeled using delay data from the Bureau of Transportation Statistics. This pattern appears to be caused primarily by the frequency and amount of precipitation that falls at ATL and by the amount of flights that arrive and depart at ATL.Originality/value: This information could assist airport operations personnel, FAA air traffic controllers and airlines in anticipating and mitigating delays at specific times of the year.

  16. Swelling kinetics of spray-dried chitosan acetate assessed by magnetic resonance imaging and their relation to drug release kinetics of chitosan matrix tablets.

    Science.gov (United States)

    Huanbutta, Kampanart; Sriamornsak, Pornsak; Limmatvapirat, Sontaya; Luangtana-anan, Manee; Yoshihashi, Yasuo; Yonemochi, Etsuo; Terada, Katsuhide; Nunthanid, Jurairat

    2011-02-01

    Magnetic resonance imaging (MRI) was used to assess in situ swelling behaviors of spray-dried chitosan acetate (CSA) in 0.1N HCl, pH 6.8 and pH 5.0 Tris-HCl buffers. The in vitro drug releases from CSA matrix tablets containing the model drugs, diclofenac sodium and theophylline were investigated in all media using USP-4 apparatus. The effect of chitosan molecular weight, especially in pH 6.8 Tris-HCl, was also studied. In 0.1N HCl, the drug release from the matrix tablets was the lowest in relation to the highest swelling of CSA. The swelling kinetics in Tris-HCl buffers are Fickian diffusion according to their best fit to Higuchi's model as well as the drug release kinetics in all the media. The high swelling rate (k(s)(')) was found to delay the drug release rate (k'). The linear relationship between the swelling and fractions of drug release in Tris-HCl buffers was observed, indicating an important role of the swelling on controlling the drug release mechanism. Additionally, CSA of 200 and 800 kDa chitosan did not swell in pH 6.8 Tris-HCl but disintegrated into fractions, and the drug release from the matrix tablets was the highest. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Delay and death-thought accessibility: a meta-analysis.

    Science.gov (United States)

    Steinman, Christopher T; Updegraff, John A

    2015-12-01

    The dual-process component of Terror Management Theory (TMT) proposes that different types of threats lead to increases in death-thought accessibility (DTA) after different delay intervals. Experimental studies of terror management threats' effect on DTA were collected and coded for their use of explicitly death-related (vs. not explicitly death-related) threats, and for their use of delay and task-switching during the delay. Results reveal that studies using death-related threats achieved larger DTA effect-sizes when they included more task-switching or a longer delay between the threat and the DTA measurement. In contrast, studies using threats that were not explicitly death-related achieved smaller DTA effect-sizes when they included more task-switching between the threat and the DTA measurement. These findings provide partial support for the dual-process component's predictions regarding delay and DTA. Limitations and future directions are discussed. © 2015 by the Society for Personality and Social Psychology, Inc.

  18. Observations on early and delayed colostomy closure.

    Science.gov (United States)

    Tade, A O; Salami, B A; Ayoade, B A

    2011-06-01

    Traditional treatment of a variety of colorectal pathologies had included a diverting colostomy that was closed eight or more weeks later during a readmission. The aim of this retrospective study was to determine the outcomes of early colostomy closure and delayed colostomy closure in patients with temporary colostomies following traumatic and non-traumatic colorectal pathologies. In this study early colostomy closure was the closure of a colostomy within three weeks of its construction, while delayed colostomy closure referred to closure after 3 weeks. Complete records of the 37 adult patients who had temporary colostomy constructed and closed between Jan. 1997 December 2003 for various colorectal pathologies were studied. Fourteen patients had early colostomy closure while 23 had delayed closure. In the early colostomy closure group there were 10 men and 4 women. The mean age of the patients was 28yr with a range of 18-65yr. Colostomies were closed 9-18 days after initial colostomy construction. There was no mortality. Morbidity rate 28.6% (4 out of 14). There were two faecal fistulas (14.3%). Twenty-three patients had delayed colostomy closure 8 weeks to 18 months after initial colostomy construction. These were patients unfit for early surgery after initial colostomy construction because of carcinoma, significant weight loss, or sepsis. There was no mortality. Morbidity rate was 26.1%. There were 3 faecal fistulas (13.2%). Outcomes following early colostomy closure and delayed closure were comparable. Patients fit for surgery should have early closure whilst patients who may have compromised health should have delayed closure.

  19. Time delayed Ensemble Nudging Method

    Science.gov (United States)

    An, Zhe; Abarbanel, Henry

    Optimal nudging method based on time delayed embedding theory has shows potentials on analyzing and data assimilation in previous literatures. To extend the application and promote the practical implementation, new nudging assimilation method based on the time delayed embedding space is presented and the connection with other standard assimilation methods are studied. Results shows the incorporating information from the time series of data can reduce the sufficient observation needed to preserve the quality of numerical prediction, making it a potential alternative in the field of data assimilation of large geophysical models.

  20. Time delay in a multichannel formalism

    International Nuclear Information System (INIS)

    Haberzettl, Helmut; Workman, Ron

    2007-01-01

    We reexamine the time-delay formalism of Wigner, Eisenbud, and Smith, which was developed to analyze both elastic and inelastic resonances. An error in the paper of Smith has propagated through the literature. We correct this error and show how the results of Eisenbud and Smith are related. We also comment on some recent time-delay studies, based on Smith's erroneous interpretation of the Eisenbud result

  1. Time delays, population, and economic development

    Science.gov (United States)

    Gori, Luca; Guerrini, Luca; Sodini, Mauro

    2018-05-01

    This research develops an augmented Solow model with population dynamics and time delays. The model produces either a single stationary state or multiple stationary states (able to characterise different development regimes). The existence of time delays may cause persistent fluctuations in both economic and demographic variables. In addition, the work identifies in a simple way the reasons why economics affects demographics and vice versa.

  2. Multiwire proportional counter (lecture by an electromagnetic delay line)

    International Nuclear Information System (INIS)

    Bruere-Dawson, R.

    1989-01-01

    For track localisation of ionizing particles with multiwire proportional chamber, an electronic chain including amplifying, shaping and memorizing circuits is required for each wire. In order to lower the cost of this type of detector, an electromagnetic delay line is proposed among various possibilities. In this paper, different coupling modes between chamber and delay line are studied with their respective advantages. The realization of one meter long delay line with a unit delay time of 15 ns per cm is also presented [fr

  3. Analysis of an Nth-order nonlinear differential-delay equation

    Science.gov (United States)

    Vallée, Réal; Marriott, Christopher

    1989-01-01

    The problem of a nonlinear dynamical system with delay and an overall response time which is distributed among N individual components is analyzed. Such a system can generally be modeled by an Nth-order nonlinear differential delay equation. A linear-stability analysis as well as a numerical simulation of that equation are performed and a comparison is made with the experimental results. Finally, a parallel is established between the first-order differential equation with delay and the Nth-order differential equation without delay.

  4. Profitless delays for extinction in nonautonomous Lotka-Volterra system

    Science.gov (United States)

    Liu, Shengqiang; Chen, Lansun

    2001-12-01

    We study the delayed periodic n-species Lotka-Voterra systems where the growth rate of each species is not always positive. The sufficient conditions for the extinction that are independent of the delays are obtained. Some known results are improved and generalized. Our results suggest that under some conditions, the introduction and the variance of the time delays can be both harmless and profitless. Discussion about the effect of time delays on the extinction of the system is also advanced.

  5. PWR-GALE, Radioactive Gaseous Release and Liquid Release from PWR

    International Nuclear Information System (INIS)

    Chandrasekaran, T.; Lee, J.Y.; Willis, C.A.

    1988-01-01

    1 - Description of program or function: The PWR-GALE (Boiling Water Reactor Gaseous and Liquid Effluents) Code is a computerized mathematical model for calculating the release of radioactive material in gaseous and liquid effluents from pressurized water reactors (PWRs). The calculations are based on data generated from operating reactors, field tests, laboratory tests, and plant-specific design considerations incorporated to reduce the quantity of radioactive materials that may be released to the environment. 2 - Method of solution: GALE calculates expected releases based on 1) standardized coolant activities derived from ANS Standards 18.1 Working Group recommendations, 2) release and transport mechanisms that result in the appearance of radioactive material in liquid and gaseous waste streams, 3) plant-specific design features used to reduce the quantities of radioactive materials ultimately released to the environs, and 4) information received on the operation of nuclear power plants. 3 - Restrictions on the complexity of the problem: The liquid release portion of GALE uses subroutines taken from the ORIGEN (CCC-217) to calculate radionuclide buildup and decay during collection, processing, and storage of liquid radwaste. Memory requirements for this part of the program are determined by the large nuclear data base accessed by these subroutines

  6. ANALYSING SURFACE MOVEMENT DELAYS IN AN AIRPORT

    Directory of Open Access Journals (Sweden)

    Volodymyr Kharchenko

    2014-07-01

    Full Text Available Queuing effect can be in the different components of ground operations. Causes of surface – movement delays are long taxi – in and taxi – out operations during departure and arrival of aircraft. Surface movement delays in an airport are analyzed

  7. Travelling wave solutions in delayed cooperative systems

    International Nuclear Information System (INIS)

    Li, Bingtuan; Zhang, Liang

    2011-01-01

    We establish the existence of travelling wave solutions for delayed cooperative recursions that are allowed to have more than two equilibria. We define an important extended real number that is used to determine the speeds of travelling wave solutions. The results can be applied to a large class of delayed cooperative reaction–diffusion models. We show that for a delayed Lotka–Volterra reaction–diffusion competition model, there exists a finite positive number c * + that can be characterized as the slowest speed of travelling wave solutions connecting two mono-culture equilibria or connecting a mono-culture with the coexistence equilibrium

  8. The spacing effect in immediate and delayed free recall.

    Science.gov (United States)

    Godbole, Namrata R; Delaney, Peter F; Verkoeijen, Peter P J L

    2014-01-01

    Spacing repetitions improves learning relative to massing repetitions (the spacing effect). While most studies have examined the spacing effect at short retention intervals, there are contradictory claims about its fate at a delay. Certain empirical findings suggest that the spacing effect persists at a delay. However, a recent theoretical account proposes that in free recall the spacing effect should disappear at a delay. The few studies that have examined the spacing effect at a delay are sub-optimally designed, preventing an unbiased conclusion. The current study used incidental learning and controlled recency and encoding strategy in order to examine the effect of delay on the recall of spaced items within a free recall paradigm. The results demonstrated that the spacing effect persists after a delay. The results point to an important dissociation between intentional forgetting and context-change designs (which produce more forgetting of spaced than massed items) and the passage of time (which produces similar forgetting of spaced and massed items).

  9. Dynamical response of Mathieu–Duffing oscillator with fractional-order delayed feedback

    International Nuclear Information System (INIS)

    Wen, Shao-Fang; Shen, Yong-Jun; Yang, Shao-Pu; Wang, Jun

    2017-01-01

    Highlights: • The analytical solution for Mathieu–Duffing oscillator with fractional-order delayed feedback is obtained. • The fractional-order delayed feedback has both the functions of delayed velocity feedback and delayed displacement feedback. • The special effects of time delay on nonzero periodic solutions are analyzed in detail. • The effects of the fractional-order parameters on system response are characterized. - Abstract: In this paper, the dynamical response of Mathieu–Duffing oscillator under fractional-order delayed feedback is investigated. At first, the approximate analytical solution and the amplitude-frequency equation are obtained based on the averaging method. The equivalent stiffness coefficient and equivalent damping coefficient are defined by the feedback coefficient, fractional order and time delay et al. The effects of feedback coefficient, fractional order and time delay on these two equivalent parameters are analyzed. It is found that the fractional-order delayed feedback has not only the function of delayed velocity feedback, but also the function of delayed displacement feedback. Then, the comparison of the amplitude-frequency curves obtained by the analytical and numerical solutions verifies the correctness and satisfactory precision of the approximate analytical solution. The effects of the parameters in the fractional-order delayed feedback on the complex dynamical behaviors of Mathieu–Duffing oscillator are studied. It could be found that fractional-order delayed feedback has important influences on the dynamical behavior of Mathieu–Duffing oscillator, and the results are very helpful to design, analyze or control in vibration engineering.

  10. [Influence of polymer type on the physical properties and the release study of papaverine hydrochloride from tablets].

    Science.gov (United States)

    Kasperek, Regina; Polski, Andrzej; Sobótka-Polska, Karolina; Poleszak, Ewa

    2014-01-01

    Polymers are widely used in drug manufacturing. Researchers studied their impact on the bioavailability of active substances or on physical properties of tablets for many years. To study the influence of polymer excipients, such as microcrystalline cellulose (Avicel PH 101, Avicel PH 102), croscarmellose sodium, crospovidone or polyvinylpyrrolidone, on the release profile of papaverine hydrochloride from tablets and on the physical properties of tablets. Six series of uncoated tablets were prepared by indirect method, with previous wet granulation. Tablets contained papaverine hydrochloride and various excipients. The physical properties of the prepared granules, tablets and the release profile of papaverine hydrochloride from tablets were examined. The content of papaverine hydrochloride from the release study were determined spectrophotometrically. All tablets met the pharmacopoeia requirements during following tests: the disintegration time of tablets, uncoated tablets resistance to abrasion, the weight uniformity and dose formulations, their dimensions, the resistance to crushing of tablets and the drug substance content in the tablet. In four cases more than 80% of papaverine was released up to 2 min, in one formula it was up to 5 min, and in last one up to 10 min. Tablets containing crospovidone disintegrated faster than tablets with croscarmellose sodium. Adding gelatinized starch to the tablet composition increased the disintegration time, hardness and delayed the release of papaverine. During the wet granulation process, granules containing polyvinylpyrrolidone were characterized by a suitable flow properties and slightly prolonged disintegration time. Tablets containing Avicel PH 102 compared to tablets with Avicel PH 101 had less weight loss during the test of mechanical resistance, improved hardness and faster release profile of papaverine from tablets.

  11. Delay time and tunneling transient phenomena

    International Nuclear Information System (INIS)

    Garcia-Calderon, Gaston; Villavicencio, Jorge

    2002-01-01

    Analytic solutions to the time-dependent Schroedinger equation for cutoff wave initial conditions are used to investigate the time evolution of the transmitted probability density for tunneling. For a broad range of values of the potential barrier opacity α, we find that the probability density exhibits two evolving structures. One refers to the propagation of a forerunner related to a time domain resonance [Phys. Rev. A 64, 0121907 (2001)], while the other consists of a semiclassical propagating wave front. We find a regime where the forerunners are absent, corresponding to positive time delays, and show that this regime is characterized by opacities α c . The critical opacity α c is derived from the analytical expression for the delay time, which reflects a link between transient effects in tunneling and the delay time

  12. The value of delay in tidal energy development

    International Nuclear Information System (INIS)

    MacDougall, Shelley L.

    2015-01-01

    Despite robust research, prototype development and demonstration of in-stream tidal energy devices, progress to the commercialization stage has been slow. Some of this can be attributed to a lack readiness or financing. However, when uncertainty is high, a developer may choose to delay a project until more is known. The option to delay has value for a company. This study applies the real option valuation model to an investment in a 10 MW array of in-stream tidal energy conversion devices at the Fundy Ocean Research Centre for Energy (FORCE) in the Bay of Fundy, Nova Scotia, Canada. The values of investing and the option to delay are calculated. A sensitivity analysis of key drivers and scenarios with various input values to the option model are constructed to observe the impact on the 'invest versus delay' decision. The analysis suggests there is value in owning the option to develop, by leasing a FORCE berth, but waiting while uncertainty is resolved. Implications for policy-setting are discussed. - Highlights: • Analyze an invest-vs-delay decision in tidal energy conversion using real options. • Assess whether conditions are conducive to an economically rational decision to delay. • Identify aspects of the decision that can be influenced by government policy.

  13. Lie group classification of first-order delay ordinary differential equations

    Science.gov (United States)

    Dorodnitsyn, Vladimir A.; Kozlov, Roman; Meleshko, Sergey V.; Winternitz, Pavel

    2018-05-01

    A group classification of first-order delay ordinary differential equations (DODEs) accompanied by an equation for the delay parameter (delay relation) is presented. A subset of such systems (delay ordinary differential systems or DODSs), which consists of linear DODEs and solution-independent delay relations, have infinite-dimensional symmetry algebras—as do nonlinear ones that are linearizable by an invertible transformation of variables. Genuinely nonlinear DODSs have symmetry algebras of dimension n, . It is shown how exact analytical solutions of invariant DODSs can be obtained using symmetry reduction.

  14. On minimizing the maximum broadcast decoding delay for instantly decodable network coding

    KAUST Repository

    Douik, Ahmed S.

    2014-09-01

    In this paper, we consider the problem of minimizing the maximum broadcast decoding delay experienced by all the receivers of generalized instantly decodable network coding (IDNC). Unlike the sum decoding delay, the maximum decoding delay as a definition of delay for IDNC allows a more equitable distribution of the delays between the different receivers and thus a better Quality of Service (QoS). In order to solve this problem, we first derive the expressions for the probability distributions of maximum decoding delay increments. Given these expressions, we formulate the problem as a maximum weight clique problem in the IDNC graph. Although this problem is known to be NP-hard, we design a greedy algorithm to perform effective packet selection. Through extensive simulations, we compare the sum decoding delay and the max decoding delay experienced when applying the policies to minimize the sum decoding delay and our policy to reduce the max decoding delay. Simulations results show that our policy gives a good agreement among all the delay aspects in all situations and outperforms the sum decoding delay policy to effectively minimize the sum decoding delay when the channel conditions become harsher. They also show that our definition of delay significantly improve the number of served receivers when they are subject to strict delay constraints.

  15. Improved Delay-Dependent Robust Stability Criteria for a Class of Uncertain Neutral Type Lur’e Systems with Discrete and Distributed Delays

    Directory of Open Access Journals (Sweden)

    Kaibo Shi

    2014-01-01

    Full Text Available This paper is concerned with the problem of delay-dependent robust stability analysis for a class of uncertain neutral type Lur’e systems with mixed time-varying delays. The system has not only time-varying uncertainties and sector-bounded nonlinearity, but also discrete and distributed delays, which has never been discussed in the previous literature. Firstly, by employing one effective mathematical technique, some less conservative delay-dependent stability results are established without employing the bounding technique and the mode transformation approach. Secondly, by constructing an appropriate new type of Lyapunov-Krasovskii functional with triple terms, improved delay-dependent stability criteria in terms of linear matrix inequalities (LMIs derived in this paper are much brief and valid. Furthermore, both nonlinearities located in finite sector and infinite one have been also fully taken into account. Finally, three numerical examples are presented to illustrate lesser conservatism and the advantage of the proposed main results.

  16. Proceedings of the specialists' meeting on delayed neutron nuclear data

    International Nuclear Information System (INIS)

    Katakura, Jun-ichi

    1999-07-01

    This report is the Proceedings of the Specialists' Meeting on Delayed Neutron Nuclear Data. The meeting was held on January 28-29, 1999, at the Tokai Research Establishment of Japan Atomic Energy Research Institute with the participation of thirty specialists, who are evaluators, theorist, experimentalists. Although the fraction of the delayed neutron is no more than 1% in the total neutrons emitted in the fission process, it plays an important roll in the control of fission reactor. In the meeting, the following topics were reported: the present status of delayed neutron data in the major evaluated data libraries, measurements of effective delayed neutron fraction using FCA (Fast Critical Assembly) and TCA (Tank-type Critical Assembly) and their analyses, sensitivity analysis for fast reactor, measurements of delayed neutron emission from actinides and so on. As another topics, delayed neutron in transmutation system and fission yield data were also presented. Free discussion was held on the future activity of delayed neutron data evaluation. The discussion was helpful for the future activity of the delayed neutron working group of JNDC aiming to the evaluation of delayed neutron data for JENDL-3.3. The 15 of the presented papers are indexed individually. (J.P.N.)

  17. Delay 25 an ASIC for timing adjustment in LHC

    NARCIS (Netherlands)

    Furtado, H.; Schrader, J.H.R.; Marchioro, A.; Moreira, P.

    A five channel programmable delay line ASIC was designed featuring 4 channels that allow to phase delay periodic or non-periodic digital signals and a master channel that can be used to phase delay a clock signal. The master channel serves as a calibration reference guaranteeing independence from

  18. A Polynomial Estimate of Railway Line Delay

    DEFF Research Database (Denmark)

    Cerreto, Fabrizio; Harrod, Steven; Nielsen, Otto Anker

    2017-01-01

    Railway service may be measured by the aggregate delay over a time horizon or due to an event. Timetables for railway service may dampen aggregate delay by addition of additional process time, either supplement time or buffer time. The evaluation of these variables has previously been performed...

  19. Test Anxiety and Academic Delay of Gratification

    Science.gov (United States)

    Bembenutty, Hefer

    2009-01-01

    The present study examined the relationship between college students' willingness to delay gratification, motivation, self-regulation of learning, and their level of test anxiety (N = 364). Academic delay of gratification refers to students' postponement of immediately available opportunities to satisfy impulses in favor of pursuing academic…

  20. Allee effects on population dynamics with delay

    International Nuclear Information System (INIS)

    Celik, C.; Merdan, H.; Duman, O.; Akin, O.

    2008-01-01

    In this paper, we study the stability analysis of equilibrium points of population dynamics with delay when the Allee effect occurs at low population density. Mainly, our mathematical results and numerical simulations point to the stabilizing effect of the Allee effects on population dynamics with delay

  1. Robust stability bounds for multi-delay networked control systems

    Science.gov (United States)

    Seitz, Timothy; Yedavalli, Rama K.; Behbahani, Alireza

    2018-04-01

    In this paper, the robust stability of a perturbed linear continuous-time system is examined when controlled using a sampled-data networked control system (NCS) framework. Three new robust stability bounds on the time-invariant perturbations to the original continuous-time plant matrix are presented guaranteeing stability for the corresponding discrete closed-loop augmented delay-free system (ADFS) with multiple time-varying sensor and actuator delays. The bounds are differentiated from previous work by accounting for the sampled-data nature of the NCS and for separate communication delays for each sensor and actuator, not a single delay. Therefore, this paper expands the knowledge base in multiple inputs multiple outputs (MIMO) sampled-data time delay systems. Bounds are presented for unstructured, semi-structured, and structured perturbations.

  2. Passivity analysis and synthesis for uncertain time-delay systems

    Directory of Open Access Journals (Sweden)

    Magdi S. Mahmoud

    2001-01-01

    Full Text Available In this paper, we investigate the robust passivity analysis and synthesis problems for a class of uncertain time-delay systems. This class of systems arises in the modelling effort of studying water quality constituents in fresh stream. For the analysis problem, we derive a sufficient condition for which the uncertain time-delay system is robustly stable and strictly passive for all admissible uncertainties. The condition is given in terms of a linear matrix inequality. Both the delay-independent and delay-dependent cases are considered. For the synthesis problem, we propose an observer-based design method which guarantees that the closed-loop uncertain time-delay system is stable and strictly passive for all admissible uncertainties. Several examples are worked out to illustrate the developed theory.

  3. Compensating for telecommunication delays during robotic telerehabilitation.

    Science.gov (United States)

    Consoni, Leonardo J; Siqueira, Adriano A G; Krebs, Hermano I

    2017-07-01

    Rehabilitation robotic systems may afford better care and telerehabilitation may extend the use and benefits of robotic therapy to the home. Data transmissions over distance are bound by intrinsic communication delays which can be significant enough to deem the activity unfeasible. Here we describe an approach that combines unilateral robotic telerehabilitation and serious games. This approach has a modular and distributed design that permits different types of robots to interact without substantial code changes. We demonstrate the approach through an online multiplayer game. Two users can remotely interact with each other with no force exchanges, while a smoothing and prediction algorithm compensates motions for the delay in the Internet connection. We demonstrate that this approach can successfully compensate for data transmission delays, even when testing between the United States and Brazil. This paper presents the initial experimental results, which highlight the performance degradation with increasing delays as well as improvements provided by the proposed algorithm, and discusses planned future developments.

  4. Optimal Control for Stochastic Delay Evolution Equations

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Qingxin, E-mail: mqx@hutc.zj.cn [Huzhou University, Department of Mathematical Sciences (China); Shen, Yang, E-mail: skyshen87@gmail.com [York University, Department of Mathematics and Statistics (Canada)

    2016-08-15

    In this paper, we investigate a class of infinite-dimensional optimal control problems, where the state equation is given by a stochastic delay evolution equation with random coefficients, and the corresponding adjoint equation is given by an anticipated backward stochastic evolution equation. We first prove the continuous dependence theorems for stochastic delay evolution equations and anticipated backward stochastic evolution equations, and show the existence and uniqueness of solutions to anticipated backward stochastic evolution equations. Then we establish necessary and sufficient conditions for optimality of the control problem in the form of Pontryagin’s maximum principles. To illustrate the theoretical results, we apply stochastic maximum principles to study two examples, an infinite-dimensional linear-quadratic control problem with delay and an optimal control of a Dirichlet problem for a stochastic partial differential equation with delay. Further applications of the two examples to a Cauchy problem for a controlled linear stochastic partial differential equation and an optimal harvesting problem are also considered.

  5. Complex Time-Delay Systems Theory and Applications

    CERN Document Server

    Atay, Fatihcan M

    2010-01-01

    Time delays in dynamical systems arise as an inevitable consequence of finite speeds of information transmission. Realistic models increasingly demand the inclusion of delays in order to properly understand, analyze, design, and control real-life systems. The goal of this book is to present the state-of-the-art in research on time-delay dynamics in the framework of complex systems and networks. While the mathematical theory of delay equations is quite mature, its application to the particular problems of complex systems and complexity is a newly emerging field, and the present volume aims to play a pioneering role in this perspective. The chapters in this volume are authored by renowned experts and cover both theory and applications in a wide range of fields, with examples extending from neuroscience and biology to laser physics and vehicle traffic. Furthermore, all chapters include sufficient introductory material and extensive bibliographies, making the book a self-contained reference for both students and ...

  6. Kinetics, Ca2+ dependence, and biophysical properties of integrin-mediated mechanical modulation of transmitter release from frog motor nerve terminals

    Science.gov (United States)

    Chen, B. M.; Grinnell, A. D.

    1997-01-01

    Neurotransmitter release from frog motor nerve terminals is strongly modulated by change in muscle length. Over the physiological range, there is an approximately 10% increase in spontaneous and evoked release per 1% muscle stretch. Because many muscle fibers do not receive suprathreshold synaptic inputs at rest length, this stretch-induced enhancement of release constitutes a strong peripheral amplifier of the spinal stretch reflex. The stretch modulation of release is inhibited by peptides that block integrin binding of natural ligands. The modulation varies linearly with length, with a delay of no more than approximately 1-2 msec and is maintained constant at the new length. Moreover, the stretch modulation persists in a zero Ca2+ Ringer and, hence, is not dependent on Ca2+ influx through stretch activated channels. Eliminating transmembrane Ca2+ gradients and buffering intraterminal Ca2+ to approximately normal resting levels does not eliminate the modulation, suggesting that it is not the result of release of Ca2+ from internal stores. Finally, changes in temperature have no detectable effect on the kinetics of stretch-induced changes in endplate potential (EPP) amplitude or miniature EPP (mEPP) frequency. We conclude, therefore, that stretch does not act via second messenger pathways or a chemical modification of molecules involved in the release pathway. Instead, there is direct mechanical modulation of release. We postulate that tension on integrins in the presynaptic membrane is transduced mechanically into changes in the position or conformation of one or more molecules involved in neurotransmitter release, altering sensitivity to Ca2+ or the equilibrium for a critical reaction leading to vesicle fusion.

  7. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-05-14

    This thesis presents a general framework and method for detection of an object in a video based on apparent motion. The object moves, at some unknown time, differently than the “background” motion, which can be induced from camera motion. The goal of proposed method is to detect and segment the object as soon it moves in an online manner. Since motion estimation can be unreliable between frames, more than two frames are needed to reliably detect the object. Observing more frames before declaring a detection may lead to a more accurate detection and segmentation, since more motion may be observed leading to a stronger motion cue. However, this leads to greater delay. The proposed method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms, defined as declarations of detection before the object moves or incorrect or inaccurate segmentation at the detection time. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  8. Nonlinear Cournot duopoly with implementation delays

    International Nuclear Information System (INIS)

    Matsumoto, Akio; Szidarovszky, Ferenc

    2015-01-01

    We study the effects of two delays on the local as well as on global stability of nonlinear Cournot duopoly dynamics. The two major findings are an analytical construction of the stability switching curve on which stability is lost and the numerical confirmation of the birth of aperiodic global dynamics when the stationary state is locally unstable. The delays matters and can generate various dynamics ranging from simple to complicated dynamics.

  9. The Strategic Perils of Delayed Differentiation

    OpenAIRE

    Krishnan S. Anand; Karan Girotra

    2007-01-01

    The value of delayed differentiation (also known as postponement) for a monopolist has been extensively studied in the operations literature. We analyze the case of (imperfectly) competitive markets with demand uncertainty, wherein the choice of supply chain configuration (i.e., early or delayed differentiation) is endogenous to the competing firms. We characterize firms' choices in equilibrium and analyze the effects of these choices on quantities sold, profits, consumer surplus, and welfare...

  10. Tunable delay time and Hartman effect in graphene magnetic barriers

    International Nuclear Information System (INIS)

    Ban, Yue; Wang, Lin-Jun; Chen, Xi

    2015-01-01

    Tunable group delay and Hartman effect have been investigated for massless Dirac electrons in graphene magnetic barriers. In the presence of magnetic field, dwell time is found to be equal to net group delay plus the group delay contributing from the lateral shifts. The group delay times are discussed in both cases of normal and oblique incidence, to clarify the nature of Hartman effect. In addition, the group delay in transmission can be modulated from subluminality to superluminality by adjusting the magnetic field, which may also lead to potential applications in graphene-based microelectronics

  11. Euclidean null controllability of nonlinear infinite delay systems with ...

    African Journals Online (AJOL)

    Sufficient conditions for the Euclidean null controllability of non-linear delay systems with time varying multiple delays in the control and implicit derivative are derived. If the uncontrolled system is uniformly asymptotically stable and if the control system is controllable, then the non-linear infinite delay system is Euclidean null ...

  12. Factors associated with long diagnostic delay in celiac disease.

    Science.gov (United States)

    Fuchs, Valma; Kurppa, Kalle; Huhtala, Heini; Collin, Pekka; Mäki, Markku; Kaukinen, Katri

    2014-11-01

    Here, we investigated the factors associated with long diagnostic delay in celiac disease and the impact of the national Current Care Guidelines in reducing the delay. This population-based study involved 825 adult celiac disease patients. The diagnosis was considered delayed when the interval between first symptoms and diagnosis was >10 years. The patients were asked about the duration and type of symptoms before diagnosis, time and site (tertiary, secondary, or primary care) of the diagnosis, family history of the disease, and presence of significant comorbidities. Analysis was performed by binary logistic regression. Altogether, 261 (32%) out of 825 participants reported a diagnostic delay of >10 years. Female gender, neurological or musculoskeletal disorders and presence of diarrhea, abdominal pain, and malabsorption were associated with prolonged delay. Male gender, diagnosis after the introduction of the first Current Care Guidelines in 1997, and being detected by serological screening, and family history of celiac disease were associated with a lower risk of delayed diagnosis. Factors not associated with the delay were site of diagnosis, age, and presence of dermatitis herpetiformis, type 1 diabetes, or thyroidal disease. The number of long diagnostic delays in celiac disease has decreased over the past decades. The shift of diagnostics from secondary and tertiary care to primary care has not been detrimental. National guidelines together with increased awareness and active screening in at-risk groups of celiac disease are important in these circumstances.

  13. Predictors of Delayed Healthcare Seeking Among American Muslim Women.

    Science.gov (United States)

    Vu, Milkie; Azmat, Alia; Radejko, Tala; Padela, Aasim I

    2016-06-01

    Delayed care seeking is associated with adverse health outcomes. For Muslim women, delayed care seeking might include religion-related motivations, such as a preference for female clinicians, concerns about preserving modesty, and fatalistic beliefs. Our study assesses associations between religion-related factors and delayed care seeking due to a perceived lack of female clinicians. Surveys were distributed to Muslim women attending mosque and community events in Chicago. Survey items included measures of religiosity, religious fatalism, discrimination, modesty, and alternative medicine utilization and worship practices. The outcome measure asked for levels of agreement to the statement "I have delayed seeking medical care when no woman doctor is available to see me." Two hundred fifty-four women completed the survey with nearly equal numbers of African Americans (26%), Arab Americans (33%), and South Asians (33%). Fifty-three percent reported delays in care seeking due to a perceived lack of female clinicians. In multivariate analysis adjusting for sociodemographic factors, higher religiosity (odds ratio [OR] = 5.2, p 20 years (OR = 0.22, p American Muslim women reported delays in care seeking due to a perceived lack of female clinicians. Women with higher levels of modesty and self-rated religiosity had higher odds of delaying care. Women who had lived in the United States for longer durations had lower odds of delaying care. Our research highlights the need for gender-concordant providers and culturally sensitive care for American Muslims.

  14. Risk factors of ophthalmic disorders in children with developmental delay

    DEFF Research Database (Denmark)

    Sandfeld, L.N.; Jensen, H.; Skov, L.

    2008-01-01

    PURPOSE: To identify diagnoses that increase the risk of ophthalmic disorders in developmentally delayed children. METHODS: A cross-sectional study of 1126 Danish children with developmental delay (IQ Udgivelsesdato: 2008/12......PURPOSE: To identify diagnoses that increase the risk of ophthalmic disorders in developmentally delayed children. METHODS: A cross-sectional study of 1126 Danish children with developmental delay (IQ Udgivelsesdato: 2008/12...

  15. Delaying Developmental Mathematics: The Characteristics and Costs

    Science.gov (United States)

    Johnson, Marianne; Kuennen, Eric

    2004-01-01

    This paper investigates which students delay taking a required developmental mathematics course and the impact of delay on student performance in introductory microeconomics. Analysis of a sample of 1462 students at a large Midwestern university revealed that, although developmental-level mathematics students did not reach the same level of…

  16. Delay-dependent exponential stability for neural networks with discrete and distributed time-varying delays

    International Nuclear Information System (INIS)

    Zhu Xunlin; Wang Youyi

    2009-01-01

    This Letter studies the exponential stability for a class of neural networks (NNs) with both discrete and distributed time-varying delays. Under weaker assumptions on the activation functions, by defining a more general type of Lyapunov functionals and developing a new convex combination technique, new less conservative and less complex stability criteria are established to guarantee the global exponential stability of the discussed NNs. The obtained conditions are dependent on both discrete and distributed delays, are expressed in terms of linear matrix inequalities (LMIs), and contain fewer decision variables. Numerical examples are given to illustrate the effectiveness and the less conservatism of the proposed conditions.

  17. Flash release an alternative for releasing complex MEMS devices

    NARCIS (Netherlands)

    Deladi, S.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2004-01-01

    A novel time-saving and cost-effective release technique has been developed and is described. The physical nature of the process is explained in combination with experimental observations. The results of the flash release process are compared with those of freeze-drying and supercritical CO2

  18. Thermal Aware Floorplanning Incorporating Temperature Dependent Wire Delay Estimation

    DEFF Research Database (Denmark)

    Winther, AndreasThor; Liu, Wei; Nannarelli, Alberto

    2015-01-01

    Temperature has a negative impact on metal resistance and thus wire delay. In state-of-the-art VLSI circuits, large thermal gradients usually exist due to the uneven distribution of heat sources. The difference in wire temperature can lead to performance mismatch because wires of the same length...... can have different delay. Traditional floorplanning algorithms use wirelength to estimate wire performance. In this work, we show that this does not always produce a design with the shortest delay and we propose a floorplanning algorithm taking into account temperature dependent wire delay as one...

  19. Control for delayed bilateral teleoperation of a quadrotor.

    Science.gov (United States)

    Slawiñski, E; Santiago, D; Mut, V

    2017-11-01

    This paper proposes a cascade control scheme for delayed bilateral teleoperation of a quadcopter. The strategy transforms a 6D real quadcopter to an easy-to-teleoperate 3D virtual quadcopter. The scheme is formed by a P+d plus PID controller for each dof. The analysis based on Lyapunov theory gets as result the way to set the control parameters depending on the magnitude of the asymmetric time delays (forward and backward delays). This technic aims to reach stability, simplicity and good performance in practice. Besides, experimental tests about delayed bilateral teleoperation of a quadcopter including the proposed control scheme are shown in order to evaluate the system performance. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Statistical delay estimation in digital circuits using VHDL

    Directory of Open Access Journals (Sweden)

    Milić Miljana Lj.

    2014-01-01

    Full Text Available The most important feature of modern integrated circuit is the speed. It depends on circuit's delay. For the design of high-speed digital circuits, it is necessary to evaluate delays in the earliest stages of design, thus making it easy to modify and redesign a circuit if it's too slow. This paper gives an approach for efficient delay estimation in the describing phase of the circuit design. The method can statistically estimate the minimum and maximum delay of all possible paths and signal transitions in the circuit, considering the practical implementation of circuits, and information about the parameters' tolerances. The method uses a VHDL description and is verified on ISCAS85 benchmark circuits. Matlab was used for data processing.

  1. The Strong Lensing Time Delay Challenge (2014)

    Science.gov (United States)

    Liao, Kai; Dobler, G.; Fassnacht, C. D.; Treu, T.; Marshall, P. J.; Rumbaugh, N.; Linder, E.; Hojjati, A.

    2014-01-01

    Time delays between multiple images in strong lensing systems are a powerful probe of cosmology. At the moment the application of this technique is limited by the number of lensed quasars with measured time delays. However, the number of such systems is expected to increase dramatically in the next few years. Hundred such systems are expected within this decade, while the Large Synoptic Survey Telescope (LSST) is expected to deliver of order 1000 time delays in the 2020 decade. In order to exploit this bounty of lenses we needed to make sure the time delay determination algorithms have sufficiently high precision and accuracy. As a first step to test current algorithms and identify potential areas for improvement we have started a "Time Delay Challenge" (TDC). An "evil" team has created realistic simulated light curves, to be analyzed blindly by "good" teams. The challenge is open to all interested parties. The initial challenge consists of two steps (TDC0 and TDC1). TDC0 consists of a small number of datasets to be used as a training template. The non-mandatory deadline is December 1 2013. The "good" teams that complete TDC0 will be given access to TDC1. TDC1 consists of thousands of lightcurves, a number sufficient to test precision and accuracy at the subpercent level, necessary for time-delay cosmography. The deadline for responding to TDC1 is July 1 2014. Submissions will be analyzed and compared in terms of predefined metrics to establish the goodness-of-fit, efficiency, precision and accuracy of current algorithms. This poster describes the challenge in detail and gives instructions for participation.

  2. Impact of delayed information in sub-second complex systems

    Science.gov (United States)

    Manrique, Pedro D.; Zheng, Minzhang; Johnson Restrepo, D. Dylan; Hui, Pak Ming; Johnson, Neil F.

    What happens when you slow down the delivery of information in large-scale complex systems that operate faster than the blink of an eye? This question just adopted immediate commercial, legal and political importance following U.S. regulators' decision to allow an intentional 350 microsecond delay to be added in the ultrafast network of financial exchanges. However there is still no scientific understanding available to policymakers of the potential system-wide impact of such delays. Here we take a first step in addressing this question using a minimal model of a population of competing, heterogeneous, adaptive agents which has previously been shown to produce similar statistical features to real markets. We find that while certain extreme system-level behaviors can be prevented by such delays, the duration of others is increased. This leads to a highly non-trivial relationship between delays and system-wide instabilities which warrants deeper empirical investigation. The generic nature of our model suggests there should be a fairly wide class of complex systems where such delay-driven extreme behaviors can arise, e.g. sub-second delays in brain function possibly impacting individuals' behavior, and sub-second delays in navigational systems potentially impacting the safety of driverless vehicles.

  3. Impact of delayed information in sub-second complex systems

    Directory of Open Access Journals (Sweden)

    Pedro D. Manrique

    Full Text Available What happens when you slow down the delivery of information in large-scale complex systems that operate faster than the blink of an eye? This question just adopted immediate commercial, legal and political importance following U.S. regulators’ decision to allow an intentional 350 microsecond delay to be added in the ultrafast network of financial exchanges. However there is still no scientific understanding available to policymakers of the potential system-wide impact of such delays. Here we take a first step in addressing this question using a minimal model of a population of competing, heterogeneous, adaptive agents which has previously been shown to produce similar statistical features to real markets. We find that while certain extreme system-level behaviors can be prevented by such delays, the duration of others is increased. This leads to a highly non-trivial relationship between delays and system-wide instabilities which warrants deeper empirical investigation. The generic nature of our model suggests there should be a fairly wide class of complex systems where such delay-driven extreme behaviors can arise, e.g. sub-second delays in brain function possibly impacting individuals’ behavior, and sub-second delays in navigational systems potentially impacting the safety of driverless vehicles. Keywords: Ultra-fast networks, Temporal perturbation, Competition, Modeling

  4. Break-before-make CMOS inverter for power-efficient delay implementation.

    Science.gov (United States)

    Puhan, Janez; Raič, Dušan; Tuma, Tadej; Bűrmen, Árpád

    2014-01-01

    A modified static CMOS inverter with two inputs and two outputs is proposed to reduce short-circuit current in order to increment delay and reduce power overhead where slow operation is required. The circuit is based on bidirectional delay element connected in series with the PMOS and NMOS switching transistors. It provides differences in the dynamic response so that the direct-path current in the next stage is reduced. The switching transistors are never ON at the same time. Characteristics of various delay element implementations are presented and verified by circuit simulations. Global optimization procedure is used to obtain the most power-efficient transistor sizing. The performance of the modified CMOS inverter chain is compared to standard implementation for various delays. The energy (charge) per delay is reduced up to 40%. The use of the proposed delay element is demonstrated by implementing a low-power delay line and a leading-edge detector cell.

  5. Editorial Commentary: "Defer No Time, Delays Have Dangerous Ends" (Henry VI, Shakespeare): Delayed Anterior Cruciate Ligament Reconstruction Has Consequences.

    Science.gov (United States)

    Siegel, Mark G

    2018-06-01

    There continues to be controversy over the timing of anterior cruciate ligament (ACL) surgery. Early or delayed intervention after ACL injury is a topic that has not been settled. The issue is whether ACL tears should have surgery performed in an expedient manner. Or is delay an option with no repercussions to the health of the knee? My associates in nonsurgical specialties wave the New England Journal of Medicine to support their view that surgery is not needed. I routinely espouse the literature confirming that delay of surgery may cause future damage. It is now established that a failure to intervene in a timely manner does cause additional damage. I stand vindicated and can affirm to my colleagues that I have found the answer. There is no longer any doubt or equivocation. Delay in reconstructing an unstable knee does cause damage. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  6. Delayed encephalopathy after acute carbon monoxide poisoning

    Directory of Open Access Journals (Sweden)

    Mehmet İbrahim Turan

    2014-03-01

    Full Text Available Carbon monoxide poisoning is a major cause of death following attempted suicide and accidental exposures. Although clinical presentation depends on the duration and the intensity of exposure, the assessment of the severity of intoxication is difficult. A small percentage of patients who show complete initial recovery may develop delayed neurological deficits. Delayed encephalopathy after acute carbon monoxide poisoning is a rare and poor prognosis neurologic disorders and there is no specific treatment. We present a case with early onset of delayed encephalopathy after acute carbon monoxide poisoning with typical cranial imaging findings in a child with atypical history and clinical presentation.

  7. Methodology for Analysis, Modeling and Simulation of Airport Gate-waiting Delays

    Science.gov (United States)

    Wang, Jianfeng

    This dissertation presents methodologies to estimate gate-waiting delays from historical data, to identify gate-waiting-delay functional causes in major U.S. airports, and to evaluate the impact of gate operation disruptions and mitigation strategies on gate-waiting delay. Airport gates are a resource of congestion in the air transportation system. When an arriving flight cannot pull into its gate, the delay it experiences is called gate-waiting delay. Some possible reasons for gate-waiting delay are: the gate is occupied, gate staff or equipment is unavailable, the weather prevents the use of the gate (e.g. lightning), or the airline has a preferred gate assignment. Gate-waiting delays potentially stay with the aircraft throughout the day (unless they are absorbed), adding costs to passengers and the airlines. As the volume of flights increases, ensuring that airport gates do not become a choke point of the system is critical. The first part of the dissertation presents a methodology for estimating gate-waiting delays based on historical, publicly available sources. Analysis of gate-waiting delays at major U.S. airports in the summer of 2007 identifies the following. (i) Gate-waiting delay is not a significant problem on majority of days; however, the worst delay days (e.g. 4% of the days at LGA) are extreme outliers. (ii) The Atlanta International Airport (ATL), the John F. Kennedy International Airport (JFK), the Dallas/Fort Worth International Airport (DFW) and the Philadelphia International Airport (PHL) experience the highest gate-waiting delays among major U.S. airports. (iii) There is a significant gate-waiting-delay difference between airlines due to a disproportional gate allocation. (iv) Gate-waiting delay is sensitive to time of a day and schedule peaks. According to basic principles of queueing theory, gate-waiting delay can be attributed to over-scheduling, higher-than-scheduled arrival rate, longer-than-scheduled gate-occupancy time, and reduced gate

  8. Postraumatic delayed loss of vision

    International Nuclear Information System (INIS)

    Partington, C.R.; Graves, V.B.; Ruetenacht, D.A.; Weinstein, J.M.; Strother, C.M.

    1989-01-01

    The imaging studies and clinical findings in 10 patients who suffered delayed vision loss beginning 1 day to 13 years after head trauma have been reviewed. Two different primary lesions could be identified: pseudoaneurysm of the internal carotid artery and carotid cavernous fistula. The pathologic changes associated with pseudoaneurysm included compression of the optic nerves and/or chiasm by arterial aneurysm and intracranial hematoma. Carotid cavernous fistula caused delayed vision loss by compression of the optic nerves and chiasm by saccular dilatation of the cavernous sinus and by abnormal orbital venous drainage with retinal venous stasis, retinal edema, and glaucoma

  9. 20 CFR 606.42 - High unemployment delay.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false High unemployment delay. 606.42 Section 606... THE FEDERAL UNEMPLOYMENT TAX ACT; ADVANCES UNDER TITLE XII OF THE SOCIAL SECURITY ACT Relief from Interest Payment § 606.42 High unemployment delay. (a) Applicability. Paragraph (9) of section 1202 (b) of...

  10. 45 CFR 164.412 - Law enforcement delay.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Law enforcement delay. 164.412 Section 164.412 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES ADMINISTRATIVE DATA STANDARDS AND RELATED... § 164.412 Law enforcement delay. If a law enforcement official states to a covered entity or business...

  11. [Neuropsychomotor developmental delay: conceptual map, term definitions, uses and limitations].

    Science.gov (United States)

    Dornelas, Lílian de Fátima; Duarte, Neuza Maria de Castro; Magalhães, Lívia de Castro

    2015-01-01

    To retrieve the origin of the term neuropsychomotor developmental delay" (NPMD), its conceptual evolution over time, and to build a conceptual map based on literature review. A literature search was performed in the SciELO Brazil, Web of Science, Science Direct, OneFile (GALE), Pubmed (Medline), Whiley Online, and Springer databases, from January of 1940 to January of 2013, using the following keywords NPMD delay, NPMD retardation, developmental delay, and global developmental delay. A total of 71 articles were selected, which were used to build the conceptual map of the term. Of the 71 references, 55 were international and 16 national. The terms developmental delay and global developmental delay were the most frequently used in the international literature and, in Brazil, delayed NPMD was the most often used. The term developmental delay emerged in the mid 1940s, gaining momentum in the 1990 s. In Brazil, the term delayed NPMD started to be used in the 1980s, and has been frequently cited and published in the literature. Delayed development was a characteristic of 13 morbidities described in 23 references. Regarding the type of use, 19 references were found, with seven forms of use. Among the references, 34 had definitions of the term, and 16 different concepts were identified. Developmental delay is addressed in the international and national literature under different names, various applications, and heterogeneous concepts. Internationally, ways to improve communication between professionals have been indicated, with standardized definition of the term and use in very specific situations up to the fifth year of life, which was not found in Brazilian publications. Copyright © 2014 Associação de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  12. On the Delay-Energy Tradeoff in Multiuser Fading Channels

    Directory of Open Access Journals (Sweden)

    Ralf R. Müller

    2009-01-01

    Full Text Available We consider the delay-energy tradeoff on a fading channel with multiuser diversity. For fixed arbitrary rates of the users, the total transmitted energy is minimized subject to a delay constraint. To achieve this goal we propose a scheme which schedules a subset of all users simultaneously. The scheduled users are allocated power to guarantee successful separation at the detector by successive decoding. In this way, we can benefit from both multiuser diversity and the near-far situation via scheduling and simultaneous transmission, respectively. We analytically show that when the number of users goes to infinity the energy required to guarantee the required user rates can be made as small as required at the cost of a higher delaydelay-energy tradeoff”. We explicitly compute the delay under the proposed scheduling policy and discuss how delay differentiation can be achieved. We extend the results to multiband multiaccess channel. Finally, all the results can be generalized in a straightforward fashion to broadcast channel due to the Gaussian multiaccess-broadcast channel duality.

  13. Phase delaying the human circadian clock with a single light pulse and moderate delay of the sleep/dark episode: no influence of iris color.

    Science.gov (United States)

    Canton, Jillian L; Smith, Mark R; Choi, Ho-Sun; Eastman, Charmane I

    2009-07-17

    Light exposure in the late evening and nighttime and a delay of the sleep/dark episode can phase delay the circadian clock. This study assessed the size of the phase delay produced by a single light pulse combined with a moderate delay of the sleep/dark episode for one day. Because iris color or race has been reported to influence light-induced melatonin suppression, and we have recently reported racial differences in free-running circadian period and circadian phase shifting in response to light pulses, we also tested for differences in the magnitude of the phase delay in subjects with blue and brown irises. Subjects (blue-eyed n = 7; brown eyed n = 6) maintained a regular sleep schedule for 1 week before coming to the laboratory for a baseline phase assessment, during which saliva was collected every 30 minutes to determine the time of the dim light melatonin onset (DLMO). Immediately following the baseline phase assessment, which ended 2 hours after baseline bedtime, subjects received a 2-hour bright light pulse (~4,000 lux). An 8-hour sleep episode followed the light pulse (i.e. was delayed 4 hours from baseline). A final phase assessment was conducted the subsequent night to determine the phase shift of the DLMO from the baseline to final phase assessment.Phase delays of the DLMO were compared in subjects with blue and brown irises. Iris color was also quantified from photographs using the three dimensions of red-green-blue color axes, as well as a lightness scale. These variables were correlated with phase shift of the DLMO, with the hypothesis that subjects with lighter irises would have larger phase delays. The average phase delay of the DLMO was -1.3 +/- 0.6 h, with a maximum delay of ~2 hours, and was similar for subjects with blue and brown irises. There were no significant correlations between any of the iris color variables and the magnitude of the phase delay. A single 2-hour bright light pulse combined with a moderate delay of the sleep/dark episode

  14. Phase delaying the human circadian clock with a single light pulse and moderate delay of the sleep/dark episode: no influence of iris color

    Directory of Open Access Journals (Sweden)

    Choi Ho-Sun

    2009-07-01

    Full Text Available Abstract Background Light exposure in the late evening and nighttime and a delay of the sleep/dark episode can phase delay the circadian clock. This study assessed the size of the phase delay produced by a single light pulse combined with a moderate delay of the sleep/dark episode for one day. Because iris color or race has been reported to influence light-induced melatonin suppression, and we have recently reported racial differences in free-running circadian period and circadian phase shifting in response to light pulses, we also tested for differences in the magnitude of the phase delay in subjects with blue and brown irises. Methods Subjects (blue-eyed n = 7; brown eyed n = 6 maintained a regular sleep schedule for 1 week before coming to the laboratory for a baseline phase assessment, during which saliva was collected every 30 minutes to determine the time of the dim light melatonin onset (DLMO. Immediately following the baseline phase assessment, which ended 2 hours after baseline bedtime, subjects received a 2-hour bright light pulse (~4,000 lux. An 8-hour sleep episode followed the light pulse (i.e. was delayed 4 hours from baseline. A final phase assessment was conducted the subsequent night to determine the phase shift of the DLMO from the baseline to final phase assessment. Phase delays of the DLMO were compared in subjects with blue and brown irises. Iris color was also quantified from photographs using the three dimensions of red-green-blue color axes, as well as a lightness scale. These variables were correlated with phase shift of the DLMO, with the hypothesis that subjects with lighter irises would have larger phase delays. Results The average phase delay of the DLMO was -1.3 ± 0.6 h, with a maximum delay of ~2 hours, and was similar for subjects with blue and brown irises. There were no significant correlations between any of the iris color variables and the magnitude of the phase delay. Conclusion A single 2-hour bright light

  15. A unified model of hydride cracking based on elasto-plastic energy release rate over a finite crack extension

    International Nuclear Information System (INIS)

    Zheng, X.J.; Metzger, D.R.; Sauve, R.G.

    1995-01-01

    A fracture criterion based on energy balance is proposed for elasto-plastic cracking at hydrides in zirconium, assuming a finite length of crack advance. The proposed elasto-plastic energy release rate is applied to the crack initiation at hydrides in smooth and notched surfaces, as well as the subsequent delayed hydride cracking (DHC) considering limited crack-tip plasticity. For a smooth or notched surface of an elastic body, the fracture parameter is related to the stress intensity factor for the initiated crack. For DHC, a unique curve relates the non-dimensionalized elasto-plastic energy release rate with the length of crack extension relative to the plastic zone size. This fracture criterion explains experimental observations concerning DHC in a qualitative manner. Quantitative comparison with experiments is made for fracture toughness and DHC tests on specimens containing certain hydride structures; very good agreement is obtained. ((orig.))

  16. 33 CFR 117.9 - Delaying opening of a draw.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Delaying opening of a draw. 117.9... DRAWBRIDGE OPERATION REGULATIONS General Requirements § 117.9 Delaying opening of a draw. No person shall unreasonably delay the opening of a draw after the signals required by § 117.15 have been given. Note: Trains...

  17. Methods of Synthesis of Automatic Control Systems with Delay

    Directory of Open Access Journals (Sweden)

    Aliaksandr Lapeta

    2013-05-01

    Full Text Available The paper investigates the procedure for introduction of systems containing delay elements. Shortcomings and difficulties in the synthesis of regulators and precompensators of control systems with delays in output and control channel where determined. The author focused on two approaches for the formation of promatrix and synthesis of control systems, considering the factor of delay.

  18. Time delay systems theory, numerics, applications, and experiments

    CERN Document Server

    Ersal, Tulga; Orosz, Gábor

    2017-01-01

    This volume collects contributions related to selected presentations from the 12th IFAC Workshop on Time Delay Systems, Ann Arbor, June 28-30, 2015. The included papers present novel techniques and new results of delayed dynamical systems. The topical spectrum covers control theory, numerical analysis, engineering and biological applications as well as experiments and case studies. The target audience primarily comprises research experts in the field of time delay systems, but the book may also be beneficial for graduate students alike. .

  19. NUMERICAL HOPF BIFURCATION OF DELAY-DIFFERENTIAL EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper we consider the numerical solution of some delay differential equations undergoing a Hopf bifurcation. We prove that if the delay differential equations have a Hopf bifurcation point atλ=λ*, then the numerical solution of the equation also has a Hopf bifurcation point atλh =λ* + O(h).

  20. On the linearity of cross-correlation delay times

    Science.gov (United States)

    Mercerat, E. D.; Nolet, G.

    2012-12-01

    We investigate the question whether a P-wave delay time Δ T estimated by locating the maximum of the cross-correlation function between data d(t) and a predicted test function s(t): γ (t) = ∫ t1t_2 s(τ ) d(τ -t) \\ {d}τ, provides an estimate of the Delta T that is (quasi-)linear with the relative velocity perturbation deltaln V_P}. Such linearity is intuitive if the data d(t) is an undeformed but delayed replica of the test signal, i.e. if d(t)=s(t-Delta T). Then the maximum of gamma (t) is shifted exactly by the delay Delta T, and linearity holds even for Delta T very large. In this case, we say that the body waves are in the ray theoretical regime and their delays, because of Fermat's Principle, depend quasi-linearly on the relative velocity (or slowness) perturbations deltaln V_P in the model. However, even if we correct for dispersion induced by the instrument response and by attenuation, body waves may show frequency dependent delay times that are caused by diffraction effects around lateral heterogeneities. It is not a-priori clear that linearity holds for Delta T, as is assumed in finite-frequency theory, if the waveforms of d(t) and s(t) differ substantially because of such dispersion. To test the linearity, we generate synthetic seismograms between two boreholes, and between the boreholes and the surface, in a 3D box of 200 × 120 × 120 m. The heterogeneity is a checkerboard with cubic anomalies of size 12 × 12 × 12 m. We test two different anomaly amplitudes: ± 2% and ± 5%, and measure Delta T using a test seismogram s(t) computed for an homogeneous medium. We also predict the delays for the 5% model from those in the 2% model by multiplying with 5/2. These predictions are in error by 10-20% of the delay, which is usually acceptable for tomography when compared with actual data errors. A slight bias in the prediction indicates that the Wielandt effect - the fact that negative delays suffer less wavefront healing than positive delays - is a