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Sample records for acidosis delays evolution

  1. Episodic, transient systemic acidosis delays evolution of the malignant phenotype: Possible mechanism for cancer prevention by increased physical activity

    Maini Philip K

    2010-04-01

    Full Text Available Abstract Background The transition from premalignant to invasive tumour growth is a prolonged multistep process governed by phenotypic adaptation to changing microenvironmental selection pressures. Cancer prevention strategies are required to interrupt or delay somatic evolution of the malignant invasive phenotype. Empirical studies have consistently demonstrated that increased physical activity is highly effective in reducing the risk of breast cancer but the mechanism is unknown. Results Here we propose the hypothesis that exercise-induced transient systemic acidosis will alter the in situ tumour microenvironment and delay tumour adaptation to regional hypoxia and acidosis in the later stages of carcinogenesis. We test this hypothesis using a hybrid cellular automaton approach. This model has been previously applied to somatic evolution on epithelial surfaces and demonstrated three phases of somatic evolution, with cancer cells escaping in turn from the constraints of limited space, nutrient supply and waste removal. In this paper we extend the model to test our hypothesis that transient systemic acidosis is sufficient to arrest, or at least delay, transition from in situ to invasive cancer. Conclusions Model simulations demonstrate that repeated episodes of transient systemic acidosis will interrupt critical evolutionary steps in the later stages of carcinogenesis resulting in substantial delay in the evolution to the invasive phenotype. Our results suggest transient systemic acidosis may mediate the observed reduction in cancer risk associated with increased physical activity. Reviewers This article was reviewed by Natalia Komarova (nominated by Marek Kimmel, Heiko Enderling (nominated by Marek Kimmel, Mark Little (nominated by Marek Kimmel and Yang Kuang.

  2. Metabolic acidosis

    Acidosis - metabolic ... Metabolic acidosis occurs when the body produces too much acid. It can also occur when the kidneys are not ... the body. There are several types of metabolic acidosis. Diabetic acidosis develops when acidic substances, known as ...

  3. Lactic Acidosis

    K.Srikanth

    2012-01-01

    Abstract. Lactic acidosis is a broad-anion gap metabolic acidosis caused by lactic acid overproduction or underutilization. The quantitative dimensions of these two mechanisms commonly differ by 1 order of magnitude. Overproduction of lactic acid, also termed type A lactic acidosis, occurs when the body must regenerate ATP without oxygen (tissue hypoxia). Circulatory, pulmonary, or hemoglobin transfer disorders are commonly responsible. Overproduction of lactate also occurs with cyanide poiso...

  4. Lactic Acidosis

    K.Srikanth

    2012-10-01

    Full Text Available Abstract. Lactic acidosis is a broad-anion gap metabolic acidosis caused by lactic acid overproduction or underutilization. The quantitative dimensions of these two mechanisms commonly differ by 1 order of magnitude. Overproduction of lactic acid, also termed type A lactic acidosis, occurs when the body must regenerate ATP without oxygen (tissue hypoxia. Circulatory, pulmonary, or hemoglobin transfer disorders are commonly responsible. Overproduction of lactate also occurs with cyanide poisoning or certain malignancies. Underutilization involves removal of lactic acid by oxidation or conversion to glucose. Liver disease, inhibition of gluconeogenesis, pyruvate dehydrogenase (thiamine deficiency, and uncoupling of oxidative phosphorylation are the most common causes. The kidneys also contribute to lactate removal. Concerns have been raised regarding the role of metformin in the production of lactic acidosis, on the basis of individual case reports. The risk appears to be considerably less than with phenformin and involves patients with underlying severe renal and cardiac dysfunction.

  5. Time Delay Evolution of Five Active Galactic Nuclei

    A. Kovačević; L. Č. Popović; A. I. Shapovalova; D. Ilić; A. N. Burenkov; V. H. Chavushyan

    2015-12-01

    Here we investigate light curves of the continuum and emission lines of five type 1 active galactic nuclei (AGN) from our monitoring campaign, to test time-evolution of their time delays. Using both modeled and observed AGN light curves, we apply Gaussian kernel-based estimator to capture variation of local patterns of their time evolving delays. The largest variations of time delays of all objects occur in the period when continuum or emission lines luminosity is the highest. However, Gaussian kernel-based method shows instability in the case of NGC 5548, 3C 390.3, E1821+643 and NGC 4051 possibly due to numerical discrepancies between damped random walk (DRW) time scale of light curves and sliding time windows of the method. The temporal variations of time lags of Arp 102B can correspond to the real nature of the time lag evolution.

  6. Acidosis and Urinary Calcium Excretion

    Alexander, R Todd; Cordat, Emmanuelle; Chambrey, Régine;

    2016-01-01

    Metabolic acidosis is associated with increased urinary calcium excretion and related sequelae, including nephrocalcinosis and nephrolithiasis. The increased urinary calcium excretion induced by metabolic acidosis predominantly results from increased mobilization of calcium out of bone and...... renal tubule and then discuss why not all gene defects that cause renal tubular acidosis are associated with hypercalciuria and nephrocalcinosis....

  7. EXISTENCE RESULTS FOR IMPULSIVE NEUTRAL EVOLUTION DIFFERENTIAL EQUATIONS WITH STATE-DEPENDENT DELAY

    2011-01-01

    This paper is mainly concerned with the existence of mild solutions to a first order impulsive neutral evolution differential equations with state-dependent delay. By suitable fixed point theorems combined with theories of evolution systems,we prove some existence theorems. As an application,an example is also given to illustrate the obtained results.

  8. Introducing time delay in the evolution of new technology: the case study of nanotechnology

    Georgalis, Evangelos E.; Aifantis, Elias C.

    2013-12-01

    Starting with Feynman's "There's Plenty of Room at the Bottom" prophetic lecture at Caltech in the 1960s, the term "nanotechnology" was first coined in the scientific literature in the 1980s. This was followed by the unprecedented growth in the corresponding scientific field in 2000 due to the financial incentive provided by President Clinton in the US, followed up by similar efforts in Europe, Japan, China and Russia. Today, nanotechnology has become a driving force for economic development, with applications in all fields of engineering, information technology, transport and energy, as well as biology and medicine. Thus, it is important to forecast its future growth and evolution on the basis of two different criteria: (1) the government and private capital invested in related activities, and (2) the number of scientific publications and popular articles dedicated to this field. This article aims to extract forecasts on the evolution of nanotechnology, using the standard logistic equation that result in familiar sigmoid curves, as well as to explore the effect of time delay on its evolution. Time delay is commonly known from previous biological and ecological models, in which time lag is either already known or can be experimentally measured. In contrast, in the case of a new technology, we must first define the method for determining time delay and then interpret its existence and role. Then we describe the implications that time delay may have on the stability of the sigmoidal behavior of nanotechnology evolution and on the related oscillations that may appear.

  9. Dynamics of second order in time evolution equations with state-dependent delay

    Chueshov, I.; Rezunenko, Oleksandr

    123-124, č. 1 (2015), s. 126-149. ISSN 0362-546X R&D Projects: GA ČR GAP103/12/2431 Institutional support: RVO:67985556 Keywords : Second order evolution equations * State dependent delay * Nonlinear plate * Finite-dimensional attractor Subject RIV: BD - Theory of Information Impact factor: 1.327, year: 2014 http://library.utia.cas.cz/separaty/2015/AS/rezunenko-0444708.pdf

  10. Renal tubular acidosis and nerve deafness.

    Dunger, D B; Brenton, D. P.; Cain, A R

    1980-01-01

    Two brothers are described with renal tubular acidosis and nerve deafness: the elder also had rickets and hypokalaemia. The parents were unaffected. Studies of urinary acidification and bicarbonate excretion were consistent with a distal tubular abnormality. This report strengthens the view previously proposed in similar cases that nerve deafness and renal tubular acidosis constitute a genetic entity. Examination for nerve deafness is indicated in any child with renal tubular acidosis.

  11. Dietary Acid Load and Metabolic Acidosis in Renal Transplant Recipients

    Berg, van den Else; Engberink, M.F.; Brink, E.J.; Baak, van M.A.; Joosten, M.M.; Gans, R.O.B.; Navis, G.; Bakker, S.J.L.

    2012-01-01

    Background and objectives Acidosis is prevalent among renal transplant recipients (RTRs) and adversely affects cardiometabolic processes. Factors contributing to acidosis are graft dysfunction and immunosuppressive drugs. Little is known about the potential influence of diet on acidosis in RTRs. Thi

  12. D-Lactic Acidosis in Humans: Review of Update

    Kang, Kyung Pyo; Lee, Sik; Kang, Sung Kyew

    2006-01-01

    D-Lactic acidosis has been well documented in ruminants. In humans, D-lactic acidosis is very rare, but D-lactic acidosis may be more common than generally believed and should be looked for in a case of metabolic acidosis in which the cause of acidosis is not apparent. The clinical presentation of D-lactic acidosis is characterized by episodes of encephalopathy and metabolic acidosis. The entity should be considered as a diagnosis in a patient who presents with metabolic acidosis accompanied ...

  13. [Hypokalemic pareses secondary to renal tubular acidosis].

    Gøransson, L G; Apeland, T; Omdal, R

    2000-01-30

    A 24 year old woman presented with flaccid paralysis, severe hypokalaemia and hyperchloremia, metabolic acidosis. Immunological tests and labial glandular biopsy indicated primary Sjögren's syndrome as the underlying cause of her distal renal tubular acidosis. The patient recovered after alkali and potassium substitution and was put on oral treatment with potassium citrate. PMID:10827521

  14. Acidosis láctica

    Caridad Soler Morejón

    2000-06-01

    Full Text Available Se conoce que el ácido láctico es un producto terminal del metabolismo anaeróbico de la glucosa, que, en condiciones normales, los niveles séricos alcanzan las 2 mEq/L o menos. La mayor parte del lactato se elimina de forma muy eficaz por el hígado y se utiliza en la gluconeogénesis o para obtener energía. Si se producen incrementos considerables de las cifras de lactato sérico con disminución del metabolismo de conversión de lactato a piruvato se instala un cuadro de acidosis metabólica, a menudo grave, que puede llevar al paciente a la muerte. Desde el punto de vista clínico se debe sospechar ante un paciente con acidosis metabólica no bien explicada y anión Gap elevado, el cual se encuentra por encima de 25-30 mEq/L, aún en presencia de insuficiencia renal, de cetoacidosis o de la ingestión de un tóxico. La prevención de la hipoxia hística desempeña un papel importantísimo y en este sentido todas las medidas que contribuyen a garantizar una buena perfusión hística. Se señala la importancia del control adecuado de la diabetes mellitus, la selección más adecuada de hipoglicemiantes, el aporte de tiamina en los pacientes de riesgo, entre otras medidasIt is know that lactic acid is a last product of glucose anaerobic metabolism, that, in normal conditions, serum levels reach 2 mEq/L or less. Most of lactate is released in a very efficacious way by liver and is used in gluconeogenesis or to obtain energy. If there are significant increases of serum lactate figures with a decrease of metabolism of the conversion of lactate in pyruvate, a situation of metabolic acidosis frequently serious will present, which may provoke death of patient. From the clinical point of view, it must be suspected in a patient with non well explained metabolic acidosis and a high anion gap, which is over 25-30 mEq/L, even in presence of renal failure, ketoacidosis or ingestion of a toxic agent. That prevention of tissue hypoxia play a very

  15. A simple and general method for solving detailed chemical evolution with delayed production of iron and other chemical elements

    Vincenzo, Fiorenzo; Matteucci, Francesca; Spitoni, Emanuele

    2016-01-01

    In this Letter, we present a new theoretical method for solving the chemical evolution of galaxies, by assuming the instantaneous recycling approximation for chemical elements restored by massive stars and the Delay Time Distribution formalism for the delayed chemical enrichment by Type Ia Supernovae. The galaxy gas mass assembly history, together with the assumed stellar yields and initial mass function, represent the starting point of this method. We derive a very simple and general equatio...

  16. Sodium Bicarbonate Therapy in Patients with Metabolic Acidosis

    Adeva-Andany, María M.; Carlos Fernández-Fernández; David Mouriño-Bayolo; Elvira Castro-Quintela; Alberto Domínguez-Montero

    2014-01-01

    Metabolic acidosis occurs when a relative accumulation of plasma anions in excess of cations reduces plasma pH. Replacement of sodium bicarbonate to patients with sodium bicarbonate loss due to diarrhea or renal proximal tubular acidosis is useful, but there is no definite evidence that sodium bicarbonate administration to patients with acute metabolic acidosis, including diabetic ketoacidosis, lactic acidosis, septic shock, intraoperative metabolic acidosis, or cardiac arrest, is beneficial ...

  17. Understanding lactic acidosis in paracetamol (acetaminophen) poisoning

    Shah, Anoop D; Wood, David M; Dargan, Paul I

    2011-01-01

    Paracetamol (acetaminophen) is one of the most commonly taken drugs in overdose in many areas of the world, and the most common cause of acute liver failure in both the UK and USA. Paracetamol poisoning can result in lactic acidosis in two different scenarios. First, early in the course of poisoning and before the onset of hepatotoxicity in patients with massive ingestion; a lactic acidosis is usually associated with coma. Experimental evidence from studies in whole animals, perfused liver sl...

  18. Moduretic-induced metabolic acidosis and hyperkalaemia.

    Wan, H. H.; Lye, M. D.

    1980-01-01

    A patient who developed significant metabolic acidosis and severe hyperkalaemia while taking Moduretic (amiloride and hydrochlorothiazide) is reported. During the period of hyperkalaemia (maximum potassium 7-6 mmol/l) the patient's whole body potassium content was normal. His acid-base balance and serum potassium returned to normal some 10 days after stopping the drug. The possible mechanism of acidosis and hyperkalaemia in this patient is discussed.

  19. Clinical profile of distal renal tubular acidosis

    Ratan Jha; Muthukrishnan, J.; Shekhar Shiradhonkar; Kiran Patro; Harikumar KVS; Modi, K.D.

    2011-01-01

    To determine the clinical profile and progression of renal dysfunction in distal renal tubular acidosis (dRTA), we retrospectively studied 96 consecutive cases of dRTA diagnosed at our center. Patients with unexplained metabolic bone disease, short stature, hypokalemia, re-current renal stones, chronic obstructive uropathy or any primary autoimmune condition known to cause dRTA were screened. Distal RTA was diagnosed on the basis of systemic metabolic acidosis with urine pH >5.5 and positive ...

  20. The genomic analysis of lactic acidosis and acidosis response in human cancers.

    Julia Ling-Yu Chen

    2008-12-01

    Full Text Available The tumor microenvironment has a significant impact on tumor development. Two important determinants in this environment are hypoxia and lactic acidosis. Although lactic acidosis has long been recognized as an important factor in cancer, relatively little is known about how cells respond to lactic acidosis and how that response relates to cancer phenotypes. We develop genome-scale gene expression studies to dissect transcriptional responses of primary human mammary epithelial cells to lactic acidosis and hypoxia in vitro and to explore how they are linked to clinical tumor phenotypes in vivo. The resulting experimental signatures of responses to lactic acidosis and hypoxia are evaluated in a heterogeneous set of breast cancer datasets. A strong lactic acidosis response signature identifies a subgroup of low-risk breast cancer patients having distinct metabolic profiles suggestive of a preference for aerobic respiration. The association of lactic acidosis response with good survival outcomes may relate to the role of lactic acidosis in directing energy generation toward aerobic respiration and utilization of other energy sources via inhibition of glycolysis. This "inhibition of glycolysis" phenotype in tumors is likely caused by the repression of glycolysis gene expression and Akt inhibition. Our study presents a genomic evaluation of the prognostic information of a lactic acidosis response independent of the hypoxic response. Our results identify causal roles of lactic acidosis in metabolic reprogramming, and the direct functional consequence of lactic acidosis pathway activity on cellular responses and tumor development. The study also demonstrates the utility of genomic analysis that maps expression-based findings from in vitro experiments to human samples to assess links to in vivo clinical phenotypes.

  1. A simple and general method for solving detailed chemical evolution with delayed production of iron and other chemical elements

    Vincenzo, Fiorenzo; Spitoni, Emanuele

    2016-01-01

    In this Letter, we present a new theoretical method for solving the chemical evolution of galaxies, by assuming the instantaneous recycling approximation for chemical elements restored by massive stars and the Delay Time Distribution formalism for the delayed chemical enrichment by Type Ia Supernovae. The galaxy gas mass assembly history, together with the assumed stellar yields and initial mass function, represent the starting point of this method. We derive a very simple and general equation which closely relates the Laplace transforms of the galaxy gas accretion and star formation history, which can be used to simplify the problem of retrieving these quantities in most of current galaxy evolution models. We find that - once the galaxy star formation history has been reconstructed from our assumptions - the differential equation for the evolution of the chemical element $X$ can be suitably solved with classical methods. We apply our model to reproduce the $[\\text{O/Fe}]$ and $[\\text{Si/Fe}]$ vs. $[\\text{Fe/...

  2. Prospective strategies to delay the evolution of anti-malarial drug resistance: weighing the uncertainty

    McKenzie F Ellis

    2010-07-01

    Full Text Available Abstract Background The evolution of drug resistance in malaria parasites highlights a need to identify and evaluate strategies that could extend the useful therapeutic life of anti-malarial drugs. Such strategies are deployed to best effect before resistance has emerged, under conditions of great uncertainty. Methods Here, the emergence and spread of resistance was modelled using a hybrid framework to evaluate prospective strategies, estimate the time to drug failure, and weigh uncertainty. The waiting time to appearance was estimated as the product of low mutation rates, drug pressure, and parasite population sizes during treatment. Stochastic persistence and the waiting time to establishment were simulated as an evolving branching process. The subsequent spread of resistance was simulated in simple epidemiological models. Results Using this framework, the waiting time to the failure of artemisinin combination therapy (ACT for malaria was estimated, and a policy of multiple first-line therapies (MFTs was evaluated. The models quantify the effects of reducing drug pressure in delaying appearance, reducing the chances of establishment, and slowing spread. By using two first-line therapies in a population, it is possible to reduce drug pressure while still treating the full complement of cases. Conclusions At a global scale, because of uncertainty about the time to the emergence of ACT resistance, there was a strong case for MFTs to guard against early failure. Our study recommends developing operationally feasible strategies for implementing MFTs, such as distributing different ACTs at the clinic and for home-based care, or formulating different ACTs for children and adults.

  3. Metabolic acidosis: neo-considerations for general surgeons.

    Martin, L C E; Abah, U; Bean, E; Gupta, S

    2012-11-01

    Hyperchloraemic metabolic acidosis is a documented complication of neobladder formation. However, it usually improves with time and is mild. Severe and persistent metabolic acidosis may manifest when patients undergo further surgery for other reasons. Neobladder formation following radical cystectomy or cystoprostatectomy is becoming increasingly common, and surgeons treating patients with neobladders should recognise and treat metabolic acidosis with intravenous fluids and bicarbonate. PMID:23131216

  4. Late Metabolic Acidosis Caused by Renal Tubular Acidosis in Acute Salicylate Poisoning.

    Sakai, Norihiro; Hirose, Yasuo; Sato, Nobuhiro; Kondo, Daisuke; Shimada, Yuko; Hori, Yasushi

    2016-01-01

    A 16-year-old man was transferred to our emergency department seven hours after ingesting 486 aspirin tablets. His blood salicylate level was 83.7 mg/dL. He was treated with fluid resuscitation and sodium bicarbonate infusion, and his condition gradually improved, with a decline in the blood salicylate level. However, eight days after admission, he again reported nausea, a venous blood gas revealed metabolic acidosis with a normal anion gap. The blood salicylate level was undetectable, and a urinalysis showed glycosuria, proteinuria and elevated beta-2 microglobulin and n-acetyl glucosamine levels, with a normal urinary pH despite the acidosis. We diagnosed him with relapse of metabolic acidosis caused by renal tubular acidosis. PMID:27181539

  5. Lactic Acidosis: Current Treatments and Future Directions.

    Kraut, Jeffrey A; Madias, Nicolaos E

    2016-09-01

    Mortality rates associated with severe lactic acidosis (blood pHreduce mortality. This failure has been attributed to both reduction in serum calcium concentration and generation of excess carbon dioxide with intracellular acidification. In animal studies, hyperventilation and infusion of calcium during sodium bicarbonate administration improves cardiovascular function, suggesting that this approach could allow expression of the positive aspects of sodium bicarbonate. Other buffers, such as THAM or Carbicarb, or dialysis might also provide base with fewer untoward effects. Examination of these therapies in humans is warranted. The cellular injury associated with lactic acidosis is partly due to activation of NHE1, a cell-membrane Na(+)/H(+) exchanger. In animal studies, selective NHE1 inhibitors improve cardiovascular function, ameliorate lactic acidosis, and reduce mortality, supporting future research into their possible use in humans. Two main mechanisms contribute to lactic acid accumulation in sepsis and low-flow states: tissue hypoxia and epinephrine-induced stimulation of aerobic glycolysis. Targeting these mechanisms could allow for more specific therapy. This Acid-Base and Electrolyte Teaching Case presents a patient with acute lactic acidosis and describes current and future approaches to treatment. PMID:27291485

  6. Renal tubular acidosis complicated with hypokalemic periodic paralysis.

    Chang, Y C; Huang, C C; Chiou, Y Y; Yu, C Y

    1995-07-01

    Three Chinese girls with hypokalemic periodic paralysis secondary to different types of renal tubular acidosis are presented. One girl has primary distal renal tubular acidosis complicated with nephrocalcinosis. Another has primary Sjögren syndrome with distal renal tubular acidosis, which occurs rarely with hypokalemic periodic paralysis in children. The third has an isolated proximal renal tubular acidosis complicated with multiple organ abnormalities, unilateral carotid artery stenosis, respiratory failure, and consciousness disturbance. The diagnostic evaluation and emergent and prophylactic treatment for these three types of renal tubular acidosis are discussed. PMID:7575850

  7. Recovery of the Time-Evolution Equation of Time-Delay Systems from Time Series

    Bünner, M J; Kittel, A; Parisi, J; Meyer, Th.

    1997-01-01

    We present a method for time series analysis of both, scalar and nonscalar time-delay systems. If the dynamics of the system investigated is governed by a time-delay induced instability, the method allows to determine the delay time. In a second step, the time-delay differential equation can be recovered from the time series. The method is a generalization of our recently proposed method suitable for time series analysis of {\\it scalar} time-delay systems. The dynamics is not required to be settled on its attractor, which also makes transient motion accessible to the analysis. If the motion actually takes place on a chaotic attractor, the applicability of the method does not depend on the dimensionality of the chaotic attractor - one main advantage over all time series analysis methods known until now. For demonstration, we analyze time series, which are obtained with the help of the numerical integration of a two-dimensional time-delay differential equation. After having determined the delay time, we recover...

  8. Management of Metformin-Associated Lactic Acidosis by Continuous Renal Replacement Therapy

    Keller, Geoffray; Cour, Martin; Hernu, Romain; Illinger, Julien; Robert, Dominique; Argaud, Laurent

    2011-01-01

    Background Metformin-associated lactic acidosis (MALA) is a severe metabolic failure with high related mortality. Although its use is controversial, intermittent hemodialysis is reported to be the most frequently used treatment in conjunction with nonspecific supportive measures. Our aim was to report the evolution and outcome of cases managed by continuous renal replacement therapy (CRRT). Methodology and Principal Findings Over a 3-year period, we retrospectively identified patients admitte...

  9. Distal renal tubular acidosis and amelogenesis imperfecta: A rare association

    Ravi, P.; Ekambaranath, T. S.; Arasi, S. Ellil; Fernando, E.

    2013-01-01

    Renal tubular acidosis (RTA) is characterized by a normal anion gap with hyperchloremic metabolic acidosis. Primary distal RTA (type I) is the most common RTA in children. Childhood presentation of distal RTA includes vomiting, failure to thrive, metabolic acidosis, and hypokalemia. Amelogenesis imperfecta (AI) represents a condition where the dental enamel and oral tissues are affected in an equal manner resulting in the hypoplastic or hypopigmented teeth. We report a 10-year-old girl, previ...

  10. Self-similarity in the chemical evolution of galaxies and the delay time distribution of SNe Ia

    Walcher, C J; Minchev, I; Chiappini, C; Bergemann, M; Bruzual, G; Charlot, S; Coelho, P R T; Gallazzi, A; Martig, M

    2016-01-01

    Recent improvements in the age dating of stellar populations and single stars allow us to study the ages and abundance of stars and galaxies with unprecedented accuracy. We here compare the relation between age and \\alpha-element abundances for stars in the solar neighborhood to that of local, early-type galaxies. We find both relations to be very similar. Both fall into two regimes with a flat slope for ages younger than ~9 Gyr and a steeper slope for ages older than that value. This quantitative similarity seems surprising, given the different types of galaxies and scales involved. For the sample of early-type galaxies we also show that the data are inconsistent with literature delay time distributions of either single or double Gaussian shape. The data are consistent with a power law delay time distribution. We thus confirm that the delay time distribution inferred for the Milky Way from chemical evolution arguments also must apply to massive early-type galaxies. We also offer a tentative explanation for t...

  11. Drug-Induced Metabolic Acidosis [version 1; referees: 3 approved

    Amy Quynh Trang Pham

    2015-12-01

    Full Text Available Metabolic acidosis could emerge from diseases disrupting acid-base equilibrium or from drugs that induce similar derangements. Occurrences are usually accompanied by comorbid conditions of drug-induced metabolic acidosis, and clinical outcomes may range from mild to fatal. It is imperative that clinicians not only are fully aware of the list of drugs that may lead to metabolic acidosis but also understand the underlying pathogenic mechanisms. In this review, we categorized drug-induced metabolic acidosis in terms of pathophysiological mechanisms, as well as individual drugs’ characteristics.

  12. Distal renal tubular acidosis in recurrent renal stone formers

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    metabolic disturbances in renal stone formers. Distal renal tubular acidosis (dRTA) was relatively more common in female stone formers and most often found in patients with bilateral stone disease (36%). Since prophylactic treatment in renal stone formers with renal acidification defects is available, this...... (1.1%) had complete distal renal tubular acidosis and 14 (15.5%) incomplete distal renal tubular acidosis. Our results confirm that distal renal tubular acidification defects are associated with a more severe form of stone disease and make distal renal tubular acidosis one of the most frequent...

  13. Distal Renal Tubular Acidosis and Calcium Nephrolithiasis

    Moe, Orson W.; Fuster, Daniel G.; Xie, Xiao-Song

    2008-09-01

    Calcium stones are commonly encountered in patients with congenital distal renal tubular acidosis, a disease of renal acidification caused by mutations in either the vacuolar H+-ATPase (B1 or a4 subunit), anion exchanger-1, or carbonic anhydrase II. Based on the existing database, we present two hypotheses. First, heterozygotes with mutations in B1 subunit of H+-ATPase are not normal but may harbor biochemical abnormalities such as renal acidification defects, hypercalciuria, and hypocitraturia which can predispose them to kidney stone formation. Second, we propose at least two mechanisms by which mutant B1 subunit can impair H+-ATPase: defective pump assembly and defective pump activity.

  14. Acidosis láctica fatal en paciente con síndrome de inmunodeficiencia adquirido y tratamiento antiretroviral de alto grado de actividad: comunicación de un caso Fatal lactic acidosis in a patient with acquired immunodeficiency syndrome treated with highly active antiretroviral therapy: Report of one case

    Martín Lasso B; Jorge Pérez G; L. Miguel Noriega R; Rebeca Northland A

    2000-01-01

    Type B lactic acidosis occurs without any evidence of cellular hypoxia and is associated with the use of drugs or toxins. We report a 36 years old woman with acquired immunodeficiency syndrome that was admitted to the hospital with a severe lactic acidosis. She had been treated with didanosine, stavudine and efavirenz for four months prior to admission. Despite the use of high bicarbonate doses and vasoactive drugs, the patient had a catastrophic evolution and died in shock and multiple organ...

  15. Environmental influences on mosquito foraging and integrated vector management can delay the evolution of behavioral resistance.

    Stone, Chris; Chitnis, Nakul; Gross, Kevin

    2016-03-01

    Along with the scaled-up distribution of long-lasting insecticidal nets for malaria control has become concern about insecticide resistance. A related concern regards the evolution of host-seeking periodicity from the nocturnal to the crepuscular periods of the day. Why we observe such shifts in some areas but not others and which methods could prove useful in managing such behavioral resistance remain open questions. We developed a foraging model to explore whether environmental conditions affect the evolution of behavioral resistance. We looked at the role of the abundance of blood hosts and nectar sources and investigated the potential of attractive toxic sugar baits for integrated control. Higher encounter rates with hosts and nectar sources allowed behaviorally resistant populations to persist at higher levels of bed net coverage. Whereas higher encounter rates with nectar increased the threshold where resistance emerged, higher encounter rates of hosts lowered this threshold. Adding sugar baits lowered the coverage level of bed nets required to eliminate the vector population. In certain environments, using lower bed net coverage levels together with toxic sugar baits may delay or prevent the evolution of behavioral resistance. Designing sustainable control strategies will depend on an understanding of vector behavior expressed in local environmental conditions. PMID:26989441

  16. Effect of advanced and delayed rotation on the dominant flow pattern and its temporal evolution

    Uksul, Esra; Krishna, Swathi; Mulleners, Karen

    2015-11-01

    During a flapping cycle of an insect, complex time dependent flows are produced as the wing reciprocates, producing a maximum lift at the stroke reversals. By flipping the wing rapidly at the end of each stroke, the insect modulates the flow around the wing and hence the aerodynamic forces necessary to hover. The duration and starting point of the flip play an important role in determining the amount of lift produced. To understand and tailor the effect of wing kinematics on the aerodynamic performance we focussed on the vortex dynamics of the flow field. Phase-averaged data from particle image velocimetry was used to evaluate the flow features inherent to changes in rotation during a stroke of a flat plate, which is modelled based on hoverfly characteristics. The period of rotation is one-third of the total time period. A +10% phase shift is used for delayed rotation, a -10% phase shift for advanced rotation. Vortex detection methods like the λ2 and Γ2 criteria are used to determine the effect of a delay or early rotation on the trajectories, size, shape and location of the prominent vortical structures. Proper orthogonal decomposition is used to study the influence of the phase-shifts on the dominant mode structure and the related time-scales.

  17. Type IV renal tubular acidosis associated with Alport's syndrome.

    Tkácová, R.; Roland, R.; Böör, A.; Kovácová, A.; Lazúrová, I.; Tkác, I.; Hildebrand, T.; Sefara, P.

    1993-01-01

    A case of hereditary nephritis with mild reduction of renal function associated with renal tubular acidosis type IV is described. The patient was admitted with life-threatening hyperkalaemia. To our knowledge, type IV renal tubular acidosis has not been reported previously in association with Alport's syndrome in an adult patient.

  18. An unrecognised case of metabolic acidosis following neobladder augmentation cystoplasty

    David Eldred-Evans

    2015-01-01

    Conclusion: Hyperchloremic metabolic acidosis is a well-established complication of urinary diversion. Patient with orthotopic neobladder with high residual urine and large capacity are at even higher risk of metabolic acidosis. This information should be clearly documented in the post-operative discharge documentation to ensure early recognition by non-specialists.

  19. Clinical profile of distal renal tubular acidosis

    Ratan Jha

    2011-01-01

    Full Text Available To determine the clinical profile and progression of renal dysfunction in distal renal tubular acidosis (dRTA, we retrospectively studied 96 consecutive cases of dRTA diagnosed at our center. Patients with unexplained metabolic bone disease, short stature, hypokalemia, re-current renal stones, chronic obstructive uropathy or any primary autoimmune condition known to cause dRTA were screened. Distal RTA was diagnosed on the basis of systemic metabolic acidosis with urine pH >5.5 and positive urine anion gap. In those patients who had fasting urine pH >5.5 with normal baseline systemic pH and bicarbonate levels (incomplete RTA, acid load test with ammonium chloride was done. A cause of dRTA could be established in 53 (54% patients. Urological defect in children (22/44 and autoimmune disease in adults (11/52 were the commonest causes. Hypokalemic paralysis, proximal muscle weakness and voiding difficulty were the common modes of presentation. Doubling of serum creatinine during the study period was noted in 13 out of 27 patients who had GFR 60 mL/min (P <0.005. In conclusion, urological disorders were the commonest cause of dRTA in children while autoimmune disorders were the commonest asso-ciation in adults. Worse baseline renal function, longer duration of disease and greater frequency of nephrolithiasis/nephrocalcinosis and urological disorders were noted in those who had wor-sening of renal dysfunction during the study period.

  20. Clinical profile of distal renal tubular acidosis.

    Jha, Ratan; Muthukrishnan, J; Shiradhonkar, Shekhar; Patro, Kiran; Harikumar, Kvs; Modi, K D

    2011-03-01

    To determine the clinical profile and progression of renal dysfunction in distal renal tubular acidosis (dRTA), we retrospectively studied 96 consecutive cases of dRTA diagnosed at our center. Patients with unexplained metabolic bone disease, short stature, hypokalemia, re-current renal stones, chronic obstructive uropathy or any primary autoimmune condition known to cause dRTA were screened. Distal RTA was diagnosed on the basis of systemic metabolic acidosis with urine pH >5.5 and positive urine anion gap. In those patients who had fasting urine pH >5.5 with normal baseline systemic pH and bicarbonate levels (incomplete RTA), acid load test with ammonium chloride was done. A cause of dRTA could be established in 53 (54%) patients. Urological defect in children (22/44) and autoimmune disease in adults (11/52) were the commonest causes. Hypokalemic paralysis, proximal muscle weakness and voiding difficulty were the common modes of presentation. Doubling of serum creatinine during the study period was noted in 13 out of 27 patients who had GFR 60 mL/min (P <0.005). In conclusion, urological disorders were the commonest cause of dRTA in children while autoimmune disorders were the commonest asso-ciation in adults. Worse baseline renal function, longer duration of disease and greater frequency of nephrolithiasis/nephrocalcinosis and urological disorders were noted in those who had wor-sening of renal dysfunction during the study period. PMID:21422623

  1. Renal tubular acidosis due to the milk-alkali syndrome.

    Rochman, J; Better, O S; Winaver, J; Chaimowitz, C; Barzilai, A; Jacobs, R

    1977-06-01

    A 60-year-old man with a history of excessive ingestion of calcium carbonate presented with azotemia, hypercalcemia and hyperphosphatemia. His acid-base status was initially normal. Following the cessation of calcium carbonate treatment, the hypercalcemia and azotemia disappeared, and the patient was found to be in metabolic acidosis with blunted acid excretion and a urine pH of 6.1. Kidney biopsy showed focal tubular calcification; the tubular damage was apparently caused by hypercalcemia and had resulted in renal tubular acidosis. During the three months of observation since that time there has been a tendecy for spontaneous remission of the renal tubular acidosis. Impaired renal hydrogen ion excretion prevented the development of metabolic alkalosis despite ingestion of alkali initially, and was later responsible for the metabolic acidosis. Renal tubular acidosis occurring as a sequel to the milk-alkali syndrome may aggravate the danger of nephrocalcinosis in this syndrome. PMID:885714

  2. Distal renal tubular acidosis and amelogenesis imperfecta: A rare association.

    Ravi, P; Ekambaranath, T S; Arasi, S Ellil; Fernando, E

    2013-11-01

    Renal tubular acidosis (RTA) is characterized by a normal anion gap with hyperchloremic metabolic acidosis. Primary distal RTA (type I) is the most common RTA in children. Childhood presentation of distal RTA includes vomiting, failure to thrive, metabolic acidosis, and hypokalemia. Amelogenesis imperfecta (AI) represents a condition where the dental enamel and oral tissues are affected in an equal manner resulting in the hypoplastic or hypopigmented teeth. We report a 10-year-old girl, previously asymptomatic presented with the hypokalemic paralysis and on work-up found out to have type I RTA. The discoloration of teeth and enamel was diagnosed as AI. PMID:24339526

  3. Lactic Acidosis in a Patient with Type 2 Diabetes Mellitus.

    Weisberg, Lawrence S

    2015-08-01

    Lactic acidosis occurs when lactate production exceeds its metabolism. There are many possible causes of lactic acidosis, and in any given patient, several causes may coexist. This Attending Rounds presents a case in point. Metformin's role in the pathogenesis of lactic acidosis in patients with diabetes mellitus is complex, as the present case illustrates. The treatment of lactic acidosis is controversial, except for the imperative to remedy its underlying cause. The use of sodium bicarbonate to treat the often alarming metabolic derangements may be quite efficacious in that regard but is of questionable benefit to patients. Renal replacement therapies (RRTs) have particular appeal in this setting for a variety of reasons, but their effect on clinical outcomes is untested. PMID:25762524

  4. Side Effects of HIV Medicines: HIV and Lactic Acidosis

    ... HIV medicines. All HIV medicines in the nucleoside reverse transcriptase inhibitor (NRTI) drug class may cause lactic acidosis, but ... some HIV medicines. HIV medicines in the nucleoside reverse transcriptase inhibitor (NRTI) drug class can cause the body to ...

  5. [Primary distal renal tubular acidosis: a case report].

    Abdallah, Jihene Ben; Charfeddine, Bassem; Braham, Imen; Neffati, Souhir; Othmen, Leila Ben; Letaief, Affef; Smach, Mohamed Ali; Bourfifa, Zoheier; Dridi, Hedi; Limem, Khalifa

    2011-01-01

    The primary distal renal tubular acidosis is characterized biochemically by the inability of the kidney to produce appropriately acid urine in the presence of systemic metabolic acidosis or after acid loading (e.g. ammonium chloride). It is secondary to defective excretion of H(+) by the cells of the collecting duct. We report the observation of the child MC, 4-year-old, for whom the association of polyuria-polydipsia syndrome, a failure to thrive, nephrolithiasis, hypercalciuria, and especially a high urine pH in the presence of metabolic acidosis did evoke diagnosis of distal renal tubular acidosis. An urine acidification test with ammonium chloride was performed, the urinary pH was always higher than 5.5, thus confirming the diagnosis. PMID:21464016

  6. Acute Isoniazid Intoxication: Convulsion, Rhabdomyolysis and Metabolic Acidosis

    OKUTUR, Sadi Kerem

    2006-01-01

    Isoniazid is one of the most commonly used antituberculous drugs. Acute intoxication is characterized by repetitious convulsions, high anion gap metabolic acidosis and coma. The basis of therapy consists of parenteral pyridoxine administration in a dose equivalent to that of isoniazid ingested. Here we present a case of acute isoniazid intoxication presenting with convulsions and metabolic acidosis with consequent rhabdomyolysis and discuss the clinical signs and pathophysiology of isoniazid ...

  7. Renal tubular acidosis secondary to jejunoileal bypass for morbid obesity

    Schaffalitzky de Muckadell, O B; Ladefoged, Jens; Thorup, Jørgen Mogens

    1985-01-01

    Renal handling of acid and base was studied in patients with persistent metabolic acidosis 3-9 years after jejunoileal bypass for morbid obesity. Excretion of acid was studied before and after intravenous infusion of NH4Cl and excretion of bicarbonate after infusion of NaHCO3. Bypass patients...... groups. Fractional loss of bicarbonate in urine was higher in controls than in bypass patients. The renal impairment is classified as distal renal tubular acidosis....

  8. Treatment of Lactic Acidosis with Dichloroacetate in Dogs

    Park, Robert; Arieff, Allen I.; Leach, William; Lazarowitz, Virginia C.

    1982-01-01

    Lactic acidosis is a clinical condition due to accumulation of H+ ions from lactic acid, characterized by blood lactate levels >5 mM and arterial pH 60%. Dichloroacetate (DCA) is a compound that lowers blood lactate levels under various conditions in both man and laboratory animals. It acts to increase pyruvate oxidation by activation of pyruvate dehydrogenase. We evaluated the effects of DCA in the treatment of two different models of type B experimental lactic acidosis in diabetic dogs: hep...

  9. Metformin-induced lactic acidosis: a case series

    Silvestre Joana; Carvalho Susana; Mendes Vitor; Coelho Luis; Tapadinhas Camila; Ferreira Pedro; Povoa Pedro; Ceia Fatima

    2007-01-01

    Abstract Introduction Unlike other agents used in the treatment of type 2 diabetes mellitus, metformin has been shown to reduce mortality in obese patients. It is therefore being increasingly used in higher doses. The major concern of many physicians is a possible risk of lactic acidosis. The reported frequency of metformin related lactic acidosis is 0.05 per 1000 patient-years; some authors advocate that this rate is equal in those patients not taking metformin. Case presentation We present ...

  10. Benign duodenocolic fistula. A case presenting with acidosis

    Benn, Marianne; Nielsen, F T; Antonsen, H K

    1997-01-01

    A case of benign duodenocolic fistula as a complication to peptic ulcer disease is presented, the case being interesting for the rarity of the diagnosis and by being complicated with acidosis. The etiology, clinical features, diagnosis, and treatment are reviewed.......A case of benign duodenocolic fistula as a complication to peptic ulcer disease is presented, the case being interesting for the rarity of the diagnosis and by being complicated with acidosis. The etiology, clinical features, diagnosis, and treatment are reviewed....

  11. A distal renal tubular acidosis showing hyperammonemia and hyperlactacidemia

    C. Ripoli; Pinna, A.; Marras, S.; M.L. Fenu; Nurchi, A M

    2012-01-01

    Introduction: distal renal tubular acidosis (dRTA) presents itself with variable clinical manifestations and often with late expressions that impact on prognosis. Case report: A 45-day-old male infant was admitted with stopping growth, difficult feeding and vomiting after meals. Clinical tests and labs revealed a type 1 renal tubular acidosis, even if the first blood tests showed ammonium and lactate increase. We had to exclude metabolic diseases before having a certain diagnosis. Conclusions...

  12. Lactic acidosis induced by metformin: incidence, management and prevention.

    Lalau, Jean-Daniel

    2010-09-01

    Lactic acidosis associated with metformin treatment is a rare but important adverse event, and unravelling the problem is critical. First, this potential event still influences treatment strategies in type 2 diabetes mellitus, particularly in the many patients at risk of kidney failure, in those presenting contraindications to metformin and in the elderly. Second, the relationship between metformin and lactic acidosis is complex, since use of the drug may be causal, co-responsible or coincidental. The present review is divided into three parts, dealing with the incidence, management and prevention of lactic acidosis occurring during metformin treatment. In terms of incidence, the objective of this article is to counter the conventional view of the link between metformin and lactic acidosis, according to which metformin-associated lactic acidosis is rare but is still associated with a high rate of mortality. In fact, the direct metformin-related mortality is close to zero and metformin may even be protective in cases of very severe lactic acidosis unrelated to the drug. Metformin has also inherited a negative class effect, since the early biguanide, phenformin, was associated with more frequent and sometimes fatal lactic acidosis. In the second part of this review, the objective is to identify the most efficient patient management methods based on our knowledge of how metformin acts on glucose/lactate metabolism and how lactic acidosis may occur (at the organ and cellular levels) during metformin treatment. The liver appears to be a key organ for both the antidiabetic effect of metformin and the development of lactic acidosis; the latter is attributed to mitochondrial impairment and subsequent adenosine triphosphate depletion, acceleration of the glycolytic flux, increased glucose uptake and the generation of lactate, which effluxes into the circulation rather than being oxidized further. Haemodialysis should systematically be performed in severe forms of lactic

  13. Metabolic Acidosis with Ophthalmic Dorzolamide in a Neonate.

    Capino, Amanda C; Dannaway, Douglas C; Miller, Jamie L

    2016-01-01

    Carbonic anhydrase inhibitors are a common cause of normal anion gap metabolic acidosis; however, development is less commonly associated with ophthalmic administration of these agents. We report a case of a premature neonate who was being treated at our institution with betaxolol, dorzolamide, and latanoprost ophthalmic products for suspected bilateral congenital glaucoma. In addition, the patient was also receiving caffeine, ursodiol, and acidified liquid human milk fortifier. The patient developed a normal anion gap metabolic acidosis, and both dorzolamide ophthalmic solution and the acidified human milk fortifier were considered potential causes. Upon discontinuation of the dorzolamide ophthalmic solution and the switching of liquid human milk fortifiers, the normal anion gap metabolic acidosis gradually resolved. As a result of the pH and acidity, the acidified liquid human milk fortifier is thought to be associated with an anion gap acidosis; therefore, dorzolamide is suspected to be the primary cause of a normal gap acidosis. This case demonstrates that systemic effects can occur with ophthalmic administration of dorzolamide in a premature neonate. Ophthalmic agents should not be overlooked as a potential cause of systemic toxicity. PMID:27453705

  14. Acidosis Promotes Bcl-2 Family-mediated Evasion of Apoptosis

    Ryder, Christopher; McColl, Karen; Zhong, Fei; Distelhorst, Clark W.

    2012-01-01

    Acidosis arises in solid and lymphoid malignancies secondary to altered nutrient supply and utilization. Tumor acidosis correlates with therapeutic resistance, although the mechanism behind this effect is not fully understood. Here we show that incubation of lymphoma cell lines in acidic conditions (pH 6.5) blocks apoptosis induced by multiple cytotoxic metabolic stresses, including deprivation of glucose or glutamine and treatment with dexamethasone. We sought to examine the role of the Bcl-2 family of apoptosis regulators in this process. Interestingly, we found that acidic culture causes elevation of both Bcl-2 and Bcl-xL, while also attenuating glutamine starvation-induced elevation of p53-up-regulated modulator of apoptosis (PUMA) and Bim. We confirmed with knockdown studies that these shifts direct survival decisions during starvation and acidosis. Importantly, the promotion of a high anti- to pro-apoptotic Bcl-2 family member ratio by acidosis renders cells exquisitely sensitive to the Bcl-2/Bcl-xL antagonist ABT-737, suggesting that acidosis causes Bcl-2 family dependence. This dependence appears to be mediated, in part, by the acid-sensing G protein-coupled receptor, GPR65, via a MEK/ERK pathway. PMID:22685289

  15. Neurological damage arising from intrapartum hypoxia/acidosis.

    Rei, M; Ayres-de-Campos, D; Bernardes, J

    2016-01-01

    Complications occurring at any level of foetal oxygen supply will result in hypoxaemia, and this may ultimately lead to hypoxia/acidosis and neurological damage. Hypoxic-ischaemic encephalopathy (HIE) is the short-term neurological dysfunction caused by intrapartum hypoxia/acidosis, and this diagnosis requires the presence of a number of findings, including the confirmation of newborn metabolic acidosis, low Apgar scores, early imaging evidence of cerebral oedema and the appearance of clinical signs of neurological dysfunction in the first 48 h of life. Cerebral palsy (CP) consists of a heterogeneous group of nonprogressive movement and posture disorders, frequently accompanied by cognitive and sensory impairments, epilepsy, nutritional deficiencies and secondary musculoskeletal lesions. Although CP is the most common long-term neurological complication associated with intrapartum hypoxia/acidosis, >80% of cases are caused by other phenomena. Data on minor long-term neurological deficits are scarce, but they suggest that less serious intellectual and motor impairments may result from intrapartum hypoxia/acidosis. This chapter focuses on the existing evidence of neurological damage associated with poor foetal oxygenation during labour. PMID:26148854

  16. Type B Lactic Acidosis Associated With Venlafaxine Overdose.

    Iragavarapu, Chaitanya; Gupta, Tanush; Chugh, Savneek S; Aronow, Wilbert S; Frishman, William H

    2016-01-01

    Lactic acidosis that is not secondary to tissue hypoperfusion or hypoxemia (type B lactic acidosis) is a rare but potentially fatal condition that has been associated with drugs like metformin, linezolid, and nucleoside reverse-transcriptase inhibitors in patients with HIV. We report the first case of type B lactic acidosis caused by overdose of the serotonin-norepinephrine reuptake inhibitor, venlafaxine. A 55-year-old man with no significant medical history was brought to the emergency department after intentional ingestion of around 80 capsules of venlafaxine (a total dose of over 6000 mg) in an attempt to commit suicide. Complete blood count and comprehensive metabolic panel were unremarkable except for a bicarbonate level of 13 mEq/L and an anion gap of 22 mEq/L. An arterial blood gas revealed a pH of 7.39, partial pressure of CO2 of 19 mm Hg, calculated bicarbonate of 11.5 mEq/L, and a lactate level of 8.6 mmol/L. The patient was started on aggressive intravenous hydration with normal saline along with oral activated charcoal with sorbitol. Repeat laboratory work after 4 hours showed an improvement in anion gap (15 mEq/L) and serum lactate (5.6 mmol/L). The patient remained stable throughout the hospital stay and lactic acidosis resolved in 24 hours. In the absence of hypotension, hypoxemia, kidney or liver dysfunction, myopathy, malignancy, or use of other medications, venlafaxine was the most likely cause of lactic acidosis in our case. Rapid improvement of acidosis was probably related to clearance of the drug. PMID:25405896

  17. Coagulopathy induced by acidosis, hypothermia and hypocalcaemia in severe bleeding.

    De Robertis, E; Kozek-Langenecker, S A; Tufano, R; Romano, G M; Piazza, O; Zito Marinosci, G

    2015-01-01

    Acidosis, hypothermia and hypocalcaemia are determinants for morbidity and mortality during massive hemorrhages. However, precise pathological mechanisms of these environmental factors and their potential additive or synergistic anticoagulant and/or antiplatelet effects are not fully elucidated and are at least in part controversial. Best available evidences from experimental trials indicate that acidosis and hypothermia progressively impair platelet aggregability and clot formation. Considering the cell-based model of coagulation physiology, hypothermia predominantly prolongs the initiation phase, while acidosis prolongs the propagation phase of thrombin generation. Acidosis increases fibrinogen breakdown while hypothermia impairs its synthesis. Acidosis and hypothermia have additive effects. The effect of hypocalcaemia on coagulopathy is less investigated but it appears that below the cut-off of 0.9 mmol/L, several enzymatic steps in the plasmatic coagulation system are blocked while above that cut-off effects remain without clinical sequalae. The impact of environmental factor on hemostasis is underestimated in clinical practice due to our current practice of using routine coagulation laboratory tests such as partial thromboplastin time or prothrombin time, which are performed at standardized test temperature, after pH correction, and upon recalcification. Temperature-adjustments are feasible in viscoelastic point-of-care tests such as thrombelastography and thromboelastometry which may permit quantification of hypothermia-induced coagulopathy. Rewarming hypothermic bleeding patients is highly recommended because it improves patient outcome. Despite the absence of high-quality evidence, calcium supplementation is clinical routine in bleeding management. Buffer administration may not reverse acidosis-induced coagulopathy but may be essential for the efficacy of coagulation factor concentrates such as recombinant activated factor VII. PMID:24608516

  18. Ventilatory response in metabolic acidosis and cerebral blood volume in humans.

    Ven, M.T.P. van de; Colier, W.N.J.M.; Sluijs, M.C. van der; Oeseburg, B.; Folgering, H.T.M.

    2001-01-01

    The relationship between alterations in cerebral blood volume (CBV) and central chemosensitivity regulation was studied under neutral metabolic conditions and during metabolic acidosis. Fifteen healthy subjects (5610 years) were investigated. To induce metabolic acidosis, ammonium chloride (NH(4)Cl)

  19. Type 4 renal tubular acidosis in a kidney transplant recipient.

    Kulkarni, Manjunath

    2016-02-01

    We report a case of a 66-year-old diabetic patient who presented with muscle weakness 2 weeks after kidney transplantation. Her immunosuppressive regimen included tacrolimus, mycophenolate mofetil, and steroids. She was found to have hyperkalemia and normal anion gap metabolic acidosis. Tacrolimus levels were in therapeutic range. All other drugs such as beta blockers and trimethoprim - sulfamethoxazole were stopped. She did not respond to routine antikalemic measures. Further evaluation revealed type 4 renal tubular acidosis. Serum potassium levels returned to normal after starting sodium bicarbonate and fludrocortisone therapy. Though hyperkalemia is common in kidney transplant recipients, determining exact cause can guide specific treatment. PMID:27105603

  20. [5-0xoproline (pyroglutamic acid) acidosis and acetaminophen- a differential diagnosis in high anion gap metabolic acidosis].

    Weiler, Stefan; Bellmann, Romuald; Kullak-Ublick, Gerd A

    2015-12-01

    Rare cases of high anion gap metabolic acidosis during long-term paracetamol administration in therapeutic doses with causative 5-oxoproline (pyroglutamic acid} accumulation have been reported. Other concomitant risk factors such as malnutrition, alcohol abuse, renal or hepatic dysfunction, comedication with flue/oxacillin, vigabatrin, netilmicin or sepsis have been described. The etiology seems to be a drug-induced reversible inhibition of glutathione synthetase or 5-oxoprolinase leading to elevated serum and urine levels of 5-oxoproline. Other more frequent differential diagnoses, such as intoxications, ketoacidosis or lactic acidosis should be excluded. Causative substances should be stopped. 5-oxoproline concentrations in urine can be quantified to establish the diagnosis. Adverse drug reactions, which are not listed or insufficiently described in the respective Swiss product information, should be reported to the regional pharmacovigilance centres for early signal detection. 5-0 xoproline acidosis will be integrated as a potential adverse drug reaction in the Swiss product information for paracetamol. PMID:26654818

  1. Acidosis láctica fatal en paciente con síndrome de inmunodeficiencia adquirido y tratamiento antiretroviral de alto grado de actividad: comunicación de un caso Fatal lactic acidosis in a patient with acquired immunodeficiency syndrome treated with highly active antiretroviral therapy: Report of one case

    Martín Lasso B

    2000-10-01

    Full Text Available Type B lactic acidosis occurs without any evidence of cellular hypoxia and is associated with the use of drugs or toxins. We report a 36 years old woman with acquired immunodeficiency syndrome that was admitted to the hospital with a severe lactic acidosis. She had been treated with didanosine, stavudine and efavirenz for four months prior to admission. Despite the use of high bicarbonate doses and vasoactive drugs, the patient had a catastrophic evolution and died in shock and multiple organ failure, 68 hours after admission. (Rev Méd Chile 2000; 128: 1139-43.

  2. Endocrine and metabolic emergencies in children: hypocalcemia, hypoglycemia, adrenal insufficiency, and metabolic acidosis including diabetic ketoacidosis.

    Kim, Se Young

    2015-12-01

    It is important to fast diagnosis and management of the pediatric patients of the endocrine metabolic emergencies because the signs and symptoms of these disorders are nonspecific. Delayed diagnosis and treatment may lead to serious consequences of the pediatric patients, for example, cerebral dysfunction leading to coma or death of the patients with hypoglycemia, hypocalcemia, adrenal insufficiency, or diabetic ketoacidosis. The index of suspicion of the endocrine metabolic emergencies should be preceded prior to the starting nonspecific treatment. Importantly, proper diagnosis depends on the collection of blood and urine specimen before nonspecific therapy (intravenous hydration, electrolytes, glucose or calcium injection). At the same time, the taking of precise history and searching for pathognomonic physical findings should be performed. This review was described for fast diagnosis and proper management of hypoglycemic emergencies, hypocalcemia, adrenal insufficiency, and metabolic acidosis including diabetic ketoacidosis. PMID:26817004

  3. Endolymphatic Sac Enlargement in a Girl with a Novel Mutation for Distal Renal Tubular Acidosis and Severe Deafness

    Rink Nikki; Bitzan Martin; O'Gorman Gus; Nagel Mato; Torban Elena; Goodyer Paul

    2012-01-01

    Hereditary distal renal tubular acidosis (dRTA) is caused by mutations of genes encoding subunits of the H+-ATPase (ATP6V0A4 and ATP6V1B1) expressed in α -intercalated cells of the distal renal tubule and in the cochlea. We report on a 2-year-old girl with distal RTA and profound speech delay which was initially misdiagnosed as autism. Genetic analysis showed compound heterozygous mutations with one known and one novel mutation of the ATP6V1B1 gene; cerebral magnetic resonance imaging (MRI) r...

  4. Persistent lactic acidosis after chronic topical application of silver sulfadiazine in a pediatric burn patient: a review of the literature

    Willis, Monte S.; Cairns, Bruce A; Purdy, Ashley; Bortsov, Andrey V; Jones, Samuel W.; Ortiz-Pujols, Shiara M; Willis, Tina M Schade; Jr, Benny L Joyner

    2013-01-01

    A 3-year old male who sustained 2nd and 3rd degree burns that covered approximately 60% TBSA presented to a large adult and pediatric verified burn center. On hospital day (HD) 26 of his stay, Candida fungemia was identified by blood culture, delaying operative management until HD 47. On HD 47, after his first operative intervention, the patient developed a persistent metabolic and lactic acidosis. On HD 66, a search for a cause of his osmol gap of 56 mOsm/kg revealed a potential source-propy...

  5. Cerebrovascular response to acute metabolic acidosis in humans.

    Ven, M.T.P. van de; Colier, W.N.J.M.; Kersten, B.T.P.; Oeseburg, B.; Folgering, H.T.M.

    2003-01-01

    OBJECTIVES: Evaluation of the cerebrovascular response (delta CBV/delta PaCO2) during baseline metabolic conditions and acute metabolic acidosis. METHODS: 15 healthy subjects, 5 m, 10 f, 56 +/- 10 yrs were investigated. For acidification, NH4Cl was given orally. CBV was measured using Near Infrared

  6. Phenylbutyrate Therapy for Pyruvate Dehydrogenase Complex Deficiency and Lactic Acidosis

    Ferriero, Rosa; Manco, Giuseppe; Lamantea, Eleonora; Nusco, Edoardo; Ferrante, Mariella I.; Sordino, Paolo; Stacpoole, Peter W.; Lee, Brendan; Zeviani, Massimo; Brunetti-Pierri, Nicola

    2014-01-01

    Lactic acidosis is a build-up of lactic acid in the blood and tissues, which can be due to several inborn errors of metabolism as well as nongenetic conditions. Deficiency of pyruvate dehydrogenase complex (PDHC) is the most common genetic disorder leading to lactic acidosis. Phosphorylation of specific serine residues of the E1α subunit of PDHC by pyruvate dehydrogenase kinase (PDK) inactivates the enzyme, whereas dephosphorylation restores PDHC activity. We found that phenylbutyrate enhances PDHC enzymatic activity in vitro and in vivo by increasing the proportion of unphosphorylated enzyme through inhibition of PDK. Phenylbutyrate given to C57B6/L wild-type mice results in a significant increase in PDHC enzyme activity and a reduction of phosphorylated E1α in brain, muscle, and liver compared to saline-treated mice. By means of recombinant enzymes, we showed that phenylbutyrate prevents phosphorylation of E1α through binding and inhibition of PDK, providing a molecular explanation for the effect of phenylbutyrate on PDHC activity. Phenylbutyrate increases PDHC activity in fibroblasts from PDHC-deficient patients harboring various molecular defects and corrects the morphological, locomotor, and biochemical abnormalities in the noam631 zebrafish model of PDHC deficiency. In mice, phenylbutyrate prevents systemic lactic acidosis induced by partial hepatectomy. Because phenylbutyrate is already approved for human use in other diseases, the findings of this study have the potential to be rapidly translated for treatment of patients with PDHC deficiency and other forms of primary and secondary lactic acidosis. PMID:23467562

  7. Metformin-induced lactic acidosis: a case series

    Silvestre Joana

    2007-10-01

    Full Text Available Abstract Introduction Unlike other agents used in the treatment of type 2 diabetes mellitus, metformin has been shown to reduce mortality in obese patients. It is therefore being increasingly used in higher doses. The major concern of many physicians is a possible risk of lactic acidosis. The reported frequency of metformin related lactic acidosis is 0.05 per 1000 patient-years; some authors advocate that this rate is equal in those patients not taking metformin. Case presentation We present two case reports of metformin-associated lactic acidosis. The first case is a 77 year old female with a past medical history of hypertension and type 2 diabetes mellitus who had recently been prescribed metformin (3 g/day, perindopril and acetylsalicylic acid. She was admitted to the emergency department two weeks later with abdominal pain and psychomotor agitation. Physical examination revealed only signs of poor perfusion. Laboratory evaluation revealed hyperkalemia, elevated creatinine and blood urea nitrogen and mild leukocytosis. Arterial blood gases showed severe lactic acidemia. She was admitted to the intensive care unit. Vasopressor and ventilatory support was initiated and continuous venovenous hemodiafiltration was instituted. Twenty-four hours later, full clinical recovery was observed, with return to a normal serum lactate level. The patient was discharged from the intensive care unit on the sixth day. The second patient is a 69 year old male with a past medical history of hypertension, type 2 diabetes mellitus and ischemic heart disease who was on metformin (4 g/day, glycazide, acetylsalicylic acid and isosorbide dinitrate. He was admitted to the emergency department in shock with extreme bradycardia. Initial evaluation revealed severe lactic acidosis and elevated creatinine and urea. The patient was admitted to the Intensive Care Unit and commenced on continuous venovenous hemodiafiltration in addition to other supportive measures. A

  8. Development of diabetes-induced acidosis in the rat retina.

    Dmitriev, Andrey V; Henderson, Desmond; Linsenmeier, Robert A

    2016-08-01

    We hypothesized that the retina of diabetic animals would be unusually acidic due to increased glycolytic metabolism. Acidosis in tumors and isolated retina has been shown to lead to increased VEGF. To test the hypothesis we have measured the transretinal distribution of extracellular H(+) concentration (H(+)-profiles) in retinae of control and diabetic dark-adapted intact Long-Evans rats with ion-selective electrodes. Diabetes was induced by intraperitoneal injection of streptozotocin. Intact rat retinae are normally more acidic than blood with a peak of [H(+)]o in the outer nuclear layer (ONL) that averages 30 nM higher than H(+) in the choroid. Profiles in diabetic animals were similar in shape, but diabetic retinae began to be considerably more acidic after 5 weeks of diabetes. In retinae of 1-3 month diabetics the difference between the ONL and choroid was almost twice as great as in controls. At later times, up to 6 months, some diabetics still demonstrated abnormally high levels of [H(+)]o, but others were even less acidic than controls, so that the average level of acidosis was not different. Greater variability in H(+)-profiles (both between animals and between profiles recorded in one animal) distinguished the diabetic retinae from controls. Within animals, this variability was not random, but exhibited regions of higher and lower H(+). We conclude that retinal acidosis begins to develop at an early stage of diabetes (1-3 months) in rats. However, it does not progress, and the acidity of diabetic rat retina was diminished at later stages (3-6 months). Also the diabetes-induced acidosis has a strongly expressed local character. As result, the diabetic retinas show much wider variability in [H(+)] distribution than controls. pH influences metabolic and neural processes, and these results suggest that local acidosis could play a role in the pathogenesis of diabetic retinopathy. PMID:27262608

  9. Ácidosis D-láctica secundaria a síndrome de intestino corto D-Lactic acidosis secondary to short bowel syndrome

    M. J. Tapia Guerrero

    2010-10-01

    Full Text Available El síndrome de intestino corto aparece por la reducción de la superficie absortiva intestinal efectiva por pérdida funcional o anatómica de una parte de intestino delgado. Se presenta el caso de una mujer de 35 años con síndrome de intestino corto severo secundario a isquemia intestinal aguda en la edad adulta, que presenta a los 5 años de evolución episodios de mareos con inestabilidad en la marcha y pérdida de fuerza en las manos, llegándose al diagnóstico de acidosis D-láctica. La acidosis D-láctica representa una complicación infrecuente, pero importante por su sintomatología, de este síndrome. Se debe a un cambio en la flora intestinal debido a un sobrecrecimiento de bacterias acidolácticas, que producen D-lactato. Debe sospecharse en aquellos casos de acidosis sin causa aparente y manifestaciones neurológicas sin focalidad en pacientes con síndrome de intestino corto o intervenidos de by-pass yeyuno-ileal. El tratamiento apropiado resuelve con frecuencia los síntomas neurológicos y previene o reduce las recurrencias.The short bowel syndrome appears for the reduction of intestinal absorptive surface due to functional or anatomical loss of part of the small bowel. We present the case of a 35-year-old woman with severe short bowel syndrome secondary to acute intestinal ischemia in adults, who presented at 5 years of evolution episodes of dizziness with gait instability and loss of strength in hands. The diagnosis was D-lactic acidosis. D-lactic acidosis is a rare complication, but important for their symptoms, of this syndrome. It is due to a change in intestinal flora secondary to an overgrowth of lactic acid bacteria that produce D-lactate. D-lactic acidosis should be looked for in cases of metabolic acidosis in which the identity of acidosis is not apparent, neurological manifestations without focality and the patient has short bowel syndrome or patients who have had jejunoileal bypass surgery. Appropiate treatment

  10. Final Evolution and Delayed Explosions of Spinning White Dwarfs in Single Degenerate Models for Type Ia Supernovae

    Benvenuto, Omar G; Kitamura, Hikaru; Hachisu, Izumi

    2015-01-01

    We study the occurrence of delayed SNe~Ia in the single degenerate (SD) scenario. We assume that a massive carbon-oxygen (CO) white dwarf (WD) accretes matter coming from a companion star, making it to spin at the critical rate. We assume uniform rotation due to magnetic field coupling. The carbon ignition mass for non-rotating WDs is M_{ig}^{NR} \\approx 1.38 M_{\\odot}; while for the case of uniformly rotating WDs it is a few percent larger (M_{ig}^{R} \\approx 1.43 M_{\\odot}). When accretion rate decreases, the WD begins to lose angular momentum, shrinks, and spins up; however, it does not overflow its critical rotation rate, avoiding mass shedding. Thus, angular momentum losses can lead the CO WD interior to compression and carbon ignition, which would induce an SN~Ia. The delay, largely due to the angular momentum losses timescale, may be large enough to allow the companion star to evolve to a He WD, becoming undetectable at the moment of explosion. This scenario supports the occurrence of delayed SNe~Ia if...

  11. Metformin-Associated Acute Kidney Injury and Lactic Acidosis

    David Arroyo

    2011-01-01

    Full Text Available Objectives. Metformin is the preferred oral antidiabetic agent for type 2 diabetes. Lactic acidosis is described as a rare complication, usually during an acute kidney injury (AKI. Material and Methods. We conducted a prospective observational study of metformin-associated AKI cases during four years. 29 cases were identified. Previous renal function, clinical data, and outcomes were recorded. Results. An episode of acute gastroenteritis precipitated the event in 26 cases. Three developed a septic shock. Three patients died, the only related factor being liver dysfunction. More severe metabolic acidosis hyperkalemia and anemia were associated with higher probabilities of RRT requirement. We could not find any relationship between previous renal dysfunction and the outcome of the AKI. Conclusions. AKI associated to an episode of volume depletion due to gastrointestinal losses is a serious complication in type 2 diabetic patients on metformin. Previous renal dysfunction (mild-to-moderate CKD has no influence on the severity or outcome.

  12. A distal renal tubular acidosis showing hyperammonemia and hyperlactacidemia

    C. Ripoli

    2012-08-01

    Full Text Available Introduction: distal renal tubular acidosis (dRTA presents itself with variable clinical manifestations and often with late expressions that impact on prognosis. Case report: A 45-day-old male infant was admitted with stopping growth, difficult feeding and vomiting after meals. Clinical tests and labs revealed a type 1 renal tubular acidosis, even if the first blood tests showed ammonium and lactate increase. We had to exclude metabolic diseases before having a certain diagnosis. Conclusions: blood and urine investigations and genetic tests are fundamental to formulate dRTA diagnosis and to plan follow-up, according to possible phenotypic expressions of recessive and dominant autosomal forms in patients with dRTA.

  13. Acidosis ruminal en bovinos lecheros: implicaciones sobre la producción y la salud animal - Ruminal acidosis in dairy cattle: implications for animal health and production

    Granja Salcedo, Yury Tatiana

    2012-04-01

    Full Text Available ResumenLa acidosis ruminal es un importante problema en la producción de bovinos alimentados con dietas ricas en concentrados, especialmente en vacas de alta producción lechera.AbstractRuminal acidosis is a major problem in the production of cattle fed diets rich in concentrates, especially in cows of high milk production.

  14. Metabolic acidosis may be as protective as hypercapnic acidosis in an ex-vivo model of severe ventilator-induced lung injury: a pilot study

    Patsouris Efstratios

    2011-04-01

    Full Text Available Abstract Background There is mounting experimental evidence that hypercapnic acidosis protects against lung injury. However, it is unclear if acidosis per se rather than hypercapnia is responsible for this beneficial effect. Therefore, we sought to evaluate the effects of hypercapnic (respiratory versus normocapnic (metabolic acidosis in an ex vivo model of ventilator-induced lung injury (VILI. Methods Sixty New Zealand white rabbit ventilated and perfused heart-lung preparations were used. Six study groups were evaluated. Respiratory acidosis (RA, metabolic acidosis (MA and normocapnic-normoxic (Control - C groups were randomized into high and low peak inspiratory pressures, respectively. Each preparation was ventilated for 1 hour according to a standardized ventilation protocol. Lung injury was evaluated by means of pulmonary edema formation (weight gain, changes in ultrafiltration coefficient, mean pulmonary artery pressure changes as well as histological alterations. Results HPC group gained significantly greater weight than HPMA, HPRA and all three LP groups (P = 0.024, while no difference was observed between HPMA and HPRA groups regarding weight gain. Neither group differ on ultrafiltration coefficient. HPMA group experienced greater increase in the mean pulmonary artery pressure at 20 min (P = 0.0276 and 40 min (P = 0.0012 compared with all other groups. Histology scores were significantly greater in HP vs. LP groups (p Conclusions In our experimental VILI model both metabolic acidosis and hypercapnic acidosis attenuated VILI-induced pulmonary edema implying a mechanism other than possible synergistic effects of acidosis with CO2 for VILI attenuation.

  15. Blood Parameters Modification at Different Ruminal Acidosis Conditions

    Roberta De Nardi

    2013-09-01

    Full Text Available This study evaluated the reliability of various blood parameters to assess the ruminal acidosis in cattle. Six whole heifers were fed three experimental rations in a 3 x 3 Latin square design. The diets had different starch levels: high (HS, medium (MS or low (CT. Ruminal pH values were continuously measured using wireless sensors. To evaluate the severity of ruminal acidosis, the amount of time per day that the pH was below 5.8, 5.5 and 5.0 was recorded. Blood samples were analyzed for complete blood count, venous blood gas and biochemical profile at 8:00 and 12:00 h. The data were analyzed according to a mixed model. Feeding on CT, MS and HS led to significant differences in DMI (7.7 vs. 6.9 vs. 5.1 kg/d; P < 0.01 which modified the amount of time per day that the pH was below 5.0 (0 vs. 12 vs. 92 min; P < 0.10. Feeding MS and HS diets led to inflammation as indicated by the significant increment of white blood cells when compared to the CT ones and to blood concentration due to the osmotic pressure at ruminal level. Furthermore a significant decrease of bicarbonate level, CO2 partial pressure and oxyhemoglobin was observed as consequence of the activation of metabolic processes aimed to prevent metabolic acidosis. No differences were observed on blood sampling time, suggesting that one daily blood sample was enough to evaluate the metabolic variations related to ruminal acidosis.

  16. Cellular acidosis inhibits assembly, disassembly, and motility of stress granules.

    Chudinova, E M; Nadezhdina, E S; Ivanov, P A

    2012-11-01

    Stress granules (SGs) are large ribonucleoprotein (RNP)-containing particles that form in cytoplasm in response to a variety of acute changes in the cellular environment. One of the general parameters of the cell environment is pH. In some diseases, as well as in muscle fatigue, tissue acidosis occurs, leading to decrease in intracellular pH. Here we studied whether decrease in pH causes the formation of SGs in cultured animal cells, whether it affects the formation of the SGs under the action of arsenite and, if such effects occur, what are the mechanisms of the influence of acidosis. Acidosis was simulated by decreasing the pH of the culture medium, which acidified the cytoplasm. We found that medium acidification to pH 6.0 in itself did not cause formation of SGs in cells. Moreover, acidification prevented the formation of SGs under treatment with sodium arsenite or sodium arsenite together with the proteasome inhibitor MG132, and it inhibited the dissociation of preformed SGs under the influence of cycloheximide. We established that pH decrease did not affect the phosphorylation of eIF2α that occurs under the action of sodium arsenite, and even caused such phosphorylation by itself. We also found that the velocity of SG motion in cytoplasm at acidic pH was very low, and the mobile fraction of SG-incorporated PABP protein revealed by FRAP was decreased. We suppose that acidic pH impairs biochemical processes favoring assembly of RNPs in stress conditions and RNP dissociation on the termination of stress. Thus, in acidosis the reaction of the cellular translation apparatus to stress is modified. PMID:23240565

  17. Metabolic Acidosis Without Clinical Signs of Dehydration in Young Calves

    Kasari, T R; Naylor, J M

    1984-01-01

    Metabolic acidosis without clinical signs of dehydration was diagnosed in four calves between nine and 21 days of age. In each calf either coma or depression with weakness and ataxia was observed. Two calves had slow deep respirations. Treatment with intravenous administration of solutions of sodium bicarbonate was accompanied by a rise in blood pH and a return to normal demeanor, ambulation and appetites, allowing these calves to return to their respective herds.

  18. Lactic acidosis secondary to metformin overdose: a case report

    Timbrell Simon

    2012-08-01

    Full Text Available Abstract Introduction Metformin is a commonly used treatment modality in type 2 diabetes mellitus, with a well documented side effect of lactic acidosis. In the intensive care setting lactate and pH levels are regularly used as a useful predictor of poor prognosis. In this article we highlight how high lactate levels are not an accurate predictor of mortality in deliberate metformin overdose. Case presentation We present the case of a 70-year-old Caucasian man who took a deliberate metformin overdose of unknown quantity. He had a profound lactic acidosis at presentation with a pH of 6.93 and a lactate level of more than 20mmol/L. These figures would normally correspond with a mortality of more than 80%; however, with appropriate management this patient’s condition improved. Conclusion We provide evidence that the decision to treat severe lactic acidosis in deliberate metformin overdose should not be based on arterial lactate and pH levels, as would be the case in other overdoses. We also demonstrate that appropriate treatment with hemodiafiltration and 8.4% sodium bicarbonate, even in patients with a very high lactate and low pH, can be successful.

  19. Acute phase protein response during acute ruminal acidosis in cattle

    Danscher, A. M.; Thoefner, M. B.; Heegaard, Peter M. H.;

    2011-01-01

    The aim of the study was to describe the acute phase protein and leukocyte responses in dairy heifers during acute, oligofructose-induced ruminal acidosis. The study included 2 trials involving oral oligofructose overload (17g/kg BW) to nonpregnant Danish Holstein heifers. Trial 1 included 12...... performed.Heifers receiving oligofructose developed a profound ruminal and systemic acidosis (in Trial 1 and 2 lowest ruminal pH was 4.3±0.2 and 3.8±0.02, respectively, and minimum SBE was −9.3±4.1 and −8.9±2.8, respectively). In Trial 1, SAA concentrations were higher than baseline concentrations on all...... than control heifers at 18 and 24h after overload (max. 13.7±4.3 billions/L). Feeding had no effect on plasma fibrinogen concentrations or WBC in Trial 1.Acute ruminal and systemic acidosis caused by oligofructose overload resulted in distinct acute phase protein and leukocyte responses in dairy...

  20. Hypokalemic quadriparesis and rhabdomyolysis as a rare presentation of distal renal tubular acidosis.

    Ahmad Bhat, Manzoor; Ahmad Laway, Bashir; Mustafa, Farhat; Shafi Kuchay, Mohammad; Mubarik, Idrees; Ahmad Palla, Nazir

    2014-01-01

    Distal renal tubular acidosis is a syndrome of abnormal urine acidification and is characterized by hyperchloremic metabolic acidosis, hypokalemia, hypercalciurea, nephrocalcinosis and nephrolithiasis. Despite the presence of persistent hypokalemia, acute muscular paralysis is rarely encountered in males. Here, we will report an eighteen year old male patient who presented with flaccid quadriparesis and was subsequently found to have rhabdomyolysis, severe short stature, skeletal deformities and primary distal renal tubular acidosis. PMID:25250276

  1. Postoperative metabolic acidosis following the minimally invasive radiofrequency maze procedure

    Raymond Patrick Hom

    2016-01-01

    Full Text Available Purpose: Atrial fibrillation (AF is the most common arrhythmia treated in the world. While medical treatment with antiarrhythmic drugs remains the primary treatment modality, symptomatic refractory AF often requires treatment with a catheter or surgical ablation. One minimally invasive therapy is the Mini-Maze procedure, which utilizes epicardial radiofrequency ablation via a subxiphoid approach to rid the heart of arrhythmogenic atrial foci without a median sternotomy or cardiopulmonary bypass. The goal of this retrospective cohort study was to identify clinical factors associated with metabolic acidosis following the Mini-Maze procedure. Materials and Methods: After Institutional Review Board approval, we studied patients undergoing the Mini-Maze procedure, off-pump coronary artery bypass grafting or patients conventional Cox-Maze on cardiopulmonary bypass. The first base deficit value obtained in the Intensive Care Unit was used as a measure of metabolic acidosis. Using logistic regression with Akaike information criteria, we analyzed preoperative, intraoperative, and postoperative data to determine the factors associated with changes in base deficit. Results: A multivariable model using stepwise selection demonstrated that diabetes mellitus and weight were associated with a decrease in the base deficit by 2.87 mEq/L (95% CI: −5.55-−0.19 and 0.04 mEq/L (95%CI: −0.08, 0.004, respectively. Furthermore, creatinine was associated with a 1.57 mEq/L (95% CI: 0.14, 2.99 increase in the base deficit. Conclusion: The Mini-Maze procedure was not associated with postoperative metabolic acidosis. Instead, nondiabetic patients and patients with higher creatinine were associated with greater base deficits after undergoing cardiac surgery.

  2. Risk Factors for Developing Metabolic Acidosis after Radical Cystectomy and Ileal Neobladder

    Yoon, Hyun Suk; Yoon, Hana; Chung, Woo Sik; Sim, Bong Suk; Ryu, Dong-Ryeol; Lee, Dong Hyeon

    2016-01-01

    Purpose To investigate the serial changes of metabolic acidosis and identify associated risk factors in patients who underwent radical cystectomy and ileal neobladder. Material and Methods From January 2010 to August 2014, 123 patients who underwent radical cystectomy and ileal neobladder reconstruction for bladder cancer were included in this study. Metabolic acidosis was defined as a serum bicarbonate level less than 22 mEq/L and impaired renal function was defined as a GFR <50ml/min. The presence of metabolic acidosis was evaluated at 1 month, 1 year, and 2 years after surgery. Multivariate logistic regression analysis was conducted to identify risk factors associated with development of metabolic acidosis. Results Metabolic acidosis was observed in 52%, 19.5%, and 7.3% of patients at 1 month, 1 year, and 2 years after surgery, respectively. At 1 month after surgery, impaired renal function was the only independent risk factor associated with metabolic acidosis (OR 3.87, P = 0.046). At 1 year after surgery, diabetes was the only independent risk factor associated with metabolic acidosis (OR 5.68, P = 0.002). At 2 years post-surgery, both age and diabetes were significant risk factors associated with metabolic acidosis. Conclusion Approximately, half of patients experienced metabolic acidosis one month after ileal neobladder reconstruction. Preoperative impaired renal function was the most significant risk factor for developing metabolic acidosis in the early postoperative period. However, the incidence of metabolic acidosis decreased to less than 20% 1 year after surgery, and diabetes was an independent risk factor during this period. PMID:27384686

  3. Endolymphatic Sac Enlargement in a Girl with a Novel Mutation for Distal Renal Tubular Acidosis and Severe Deafness

    Rink Nikki

    2012-01-01

    Full Text Available Hereditary distal renal tubular acidosis (dRTA is caused by mutations of genes encoding subunits of the H+-ATPase (ATP6V0A4 and ATP6V1B1 expressed in α-intercalated cells of the distal renal tubule and in the cochlea. We report on a 2-year-old girl with distal RTA and profound speech delay which was initially misdiagnosed as autism. Genetic analysis showed compound heterozygous mutations with one known and one novel mutation of the ATP6V1B1 gene; cerebral magnetic resonance imaging (MRI revealed bilateral enlargement of the endolymphatic sacs of the inner ear. With improved cooperation, audiometric testing showed that hearing loss was most profound on the right, where endolymphatic sac enlargement was greatest, demonstrating a clear link between the degree of deafness and the degree of inner ear abnormality. This case indicates the value of MRI for diagnosis of inner ear involvement in very young children with distal RTA. Although citrate therapy quickly corrects the acidosis and restores growth, early diagnosis of deafness is crucial so that hearing aids can be used to assist acquisition of speech and to provide enough auditory nerve stimulation to assure the affected infants remain candidates for cochlear implantation.

  4. Endolymphatic sac enlargement in a girl with a novel mutation for distal renal tubular acidosis and severe deafness.

    Nikki, Rink; Martin, Bitzan; Gus, O'Gorman; Mato, Nagel; Elena, Torban; Paul, Goodyer

    2012-01-01

    Hereditary distal renal tubular acidosis (dRTA) is caused by mutations of genes encoding subunits of the H(+)-ATPase (ATP6V0A4 and ATP6V1B1) expressed in α-intercalated cells of the distal renal tubule and in the cochlea. We report on a 2-year-old girl with distal RTA and profound speech delay which was initially misdiagnosed as autism. Genetic analysis showed compound heterozygous mutations with one known and one novel mutation of the ATP6V1B1 gene; cerebral magnetic resonance imaging (MRI) revealed bilateral enlargement of the endolymphatic sacs of the inner ear. With improved cooperation, audiometric testing showed that hearing loss was most profound on the right, where endolymphatic sac enlargement was greatest, demonstrating a clear link between the degree of deafness and the degree of inner ear abnormality. This case indicates the value of MRI for diagnosis of inner ear involvement in very young children with distal RTA. Although citrate therapy quickly corrects the acidosis and restores growth, early diagnosis of deafness is crucial so that hearing aids can be used to assist acquisition of speech and to provide enough auditory nerve stimulation to assure the affected infants remain candidates for cochlear implantation. PMID:22966473

  5. The evolution of activity breaks in the nest cycle of annual eusocial bees: a model of delayed exponential growth

    Strohm Erhard

    2006-06-01

    Full Text Available Abstract Background Social insects show considerable variability not only in social organisation but also in the temporal pattern of nest cycles. In annual eusocial sweat bees, nest cycles typically consist of a sequence of distinct phases of activity (queen or workers collect food, construct, and provision brood cells and inactivity (nest is closed. Since the flight season is limited to the time of the year with sufficiently high temperatures and resource availability, every break reduces the potential for foraging and, thus, the productivity of a colony. This apparent waste of time has not gained much attention. Results We present a model that explains the evolution of activity breaks by assuming differential mortality during active and inactive phases and a limited rate of development of larvae, both reasonable assumptions. The model predicts a systematic temporal structure of breaks at certain times in the season which increase the fitness of a colony. The predicted pattern of these breaks is in excellent accordance with field data on the nest cycle of the halictid Lasioglossum malachurum. Conclusion Activity breaks are a counter-intuitive outcome of varying mortality rates that maximise the reproductive output of primitively eusocial nests.

  6. Reality of severe metformin-induced lactic acidosis in the absence of chronic renal impairment.

    Bruijstens, L.A.; Luin, M. van; Buscher-Jungerhans, P.M.; Bosch, F.H.

    2008-01-01

    BACKGROUND: Lactic acidosis in metformin use is a widely recognised but rare side effect. Case reports usually describe elderly patients with conditions which in themselves can cause lactic acidosis or with known contraindications to metformin. We present cases of an elderly woman, a younger woman a

  7. Type IV renal tubular acidosis and spironolactone therapy in the elderly.

    O'Connell, J. E.; Colledge, N. R.

    1993-01-01

    Spironolactone therapy is a well-known cause of hyperkalaemia, but in susceptible patient, it may also be associated with metabolic acidosis. We report a case of severe renal tubular acidosis (Type IV) with life-threatening hyperkalaemia caused by spironolactone, and discuss the mechanisms by which this may occur.

  8. Hypokalemic quadriparesis and rhabdomyolysis as a rare presentation of distal renal tubular acidosis

    Ahmad Bhat, Manzoor; Ahmad Laway, Bashir; Mustafa, Farhat; Shafi Kuchay, Mohammad; Mubarik, Idrees; Ahmad Palla, Nazir

    2014-01-01

    Distal renal tubular acidosis is a syndrome of abnormal urine acidification and is characterized by hyperchloremic metabolic acidosis, hypokalemia, hypercalciurea, nephrocalcinosis and nephrolithiasis. Despite the presence of persistent hypokalemia, acute muscular paralysis is rarely encountered in males. Here, we will report an eighteen year old male patient who presented with flaccid quadriparesis and was subsequently found to have rhabdomyolysis, severe short stature, skeletal deformities ...

  9. A perspective on Serum Lactic acid, Lactic Acidosis in a Critical Care Unit

    Agela A.Elbadri

    2013-06-01

    Full Text Available Breast cancer is one of the major surgical problems encountered in Libya. Lactic acidosis is a universal complication in breast cancer patients and can be considered a possible prognostic marker. Therefore, it will be beneficial to correctly understand and review the biochemistry underlying lactic acidosis and its possible significance as a prognostic marker in critical care patients, including breast cancer.

  10. Rumen microbial and fermentation characteristics are affected differently by bacterial probiotic supplementation during induced lactic and subacute acidosis in sheep

    Lettat Abderzak; Nozière Pierre; Silberberg Mathieu; Morgavi Diego P; Berger Claudette; Martin Cécile

    2012-01-01

    Abstract Background Ruminal disbiosis induced by feeding is the cause of ruminal acidosis, a digestive disorder prevalent in high-producing ruminants. Because probiotic microorganisms can modulate the gastrointestinal microbiota, propionibacteria- and lactobacilli-based probiotics were tested for their effectiveness in preventing different forms of acidosis. Results Lactic acidosis, butyric and propionic subacute ruminal acidosis (SARA) were induced by feed chalenges in three groups of four w...

  11. Hypertrophic cardiomyopathy, cataract, developmental delay, lactic acidosis: A novel subtype of 3-methylglutaconic aciduria

    G. Di Rosa; F. Deodato; F.J. Loupatty; C. Rizzo; R. Carrozzo; F.M. Santorelli; S. Boenzi; A. D'Amico; G. Tozzi; E. Bertini; A. Maiorana; R.J.A. Wanders; C. Dionisi-Vici

    2006-01-01

    3-Methylglutaconic aciduria is the biochemical marker of several inherited metabolic diseases. Four types of 3-methylglutaconic aciduria can be distinguished. In the type I form, accumulation of 3-methylglutaconate is due to deficient activity of 3-methylglutaconyl-CoA hydratase, an enzyme of the le

  12. Deterministically delayed pseudofractal networks

    On the basis of pseudofractal networks (PFNs), we propose a family of delayed pseudofractal networks (DPFNs) with a special feature that newly added edges delay producing new nodes, differing from the evolution algorithms of PFNs where all existing edges simultaneously generate new nodes. We obtain analytical formulae for degree distribution, clustering coefficient (C) and average path length (APL). We compare DPFNs and PFNs, and show that the exponent of the degree distribution of DPFNs is smaller than that of PFNs, meaning that the heterogeneity of this kind of delayed network is higher. Compared to PFNs, small-world features of DPFNs are more prominent (larger C and smaller APL). We also find that the delay strengthens the scale-free and small-world characteristics of DPFNs. In addition, we calculate and compare the mean first passage time (MFPT) numerically, revealing that the MFPT of DPFNs is shorter. Our study may help with a deeper understanding of various deterministically growing delayed networks

  13. Delayed fission

    Delayed fission is a nuclear process that couples beta decay and fission. In the delayed fission process, a parent nucleus undergoes beta decay or electron capture and thus populates excited states in the daughter nucleus. This review covers experimental methods for detecting and measuring delayed fission. Experimental results (ECDF activities and beta-DF activities) and theory are presented. The future prospects for study of delayed fission are discussed. 50 refs., 8 figs., 2 tabs

  14. Atypical presentation of distal renal tubular acidosis in two siblings.

    Tasic, Velibor; Korneti, Petar; Gucev, Zoran; Hoppe, Bernd; Blau, Nenad; Cheong, Hae Il

    2008-07-01

    Primary distal renal tubular acidosis (dRTA) is an inherited disease characterized by the inability of the distal tubule to lower urine pH hypokalemic paralysis. Laboratory investigations revealed proximal tubular dysfunction (low molecular weight proteinuria, generalized hyperaminoaciduria, hypophosphatemia with hyperphosphaturia, and hypouricemia with hyperuricosuria). There was significant hyperoxaluria and laboratory evidence for mild rhabdomyolysis. Under potassium and alkali therapy, proximal tubular abnormalities, muscular enzymes, and oxaluria normalized. A homozygous mutation in the ATP6V1B1 gene, which is responsible for dRTA with early hearing loss, was detected in both siblings. In conclusion, proximal tubular dysfunction and hyperoxaluria may be found in children with dRTA and are reversible under appropriate therapy. PMID:18386070

  15. Screening renal stone formers for distal renal tubular acidosis

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    A group of 110 consecutive renal stone formers were screened for distal renal tubular acidosis (RTA) using morning fasting urinary pH (mfUpH) levels followed by a short ammonium chloride loading test in patients with levels above 6.0. In 14 patients (12.7%) a renal acidification defect was noted......; 13 had incomplete and 1 had complete distal RTA. Distal RTA was found particularly in recurrent stone formers (17%), and especially in those with bilateral stone disease, where a distal renal tubular acidification defect was found in 50%. We have been unable to differentiate primary from secondary...... RTA in renal stone formers. Regardless of whether the acidification defect is primary or secondary to stone formation, however, all renal stone formers with distal RTA can expect to benefit from prophylactic alkaline therapy and it is recommended that the screening procedure, which is easy to use in...

  16. Markers of acidosis and stress in a sprint versus a conducted electrical weapon.

    Ho, Jeffrey D; Dawes, Donald M; Nystrom, Paul C; Collins, Donal P; Nelson, Rebecca S; Moore, Johanna C; Miner, James R

    2013-12-10

    Both profound acidosis and catecholamine excess have been proposed as underlying physiologic derangements in subjects at high risk for arrest related death (ARD). In this study, the objective was to determine a level of physical exertion that is "equivalent" in terms of levels of acidosis and catecholamines to a "standard" TASER X26 exposure. Data were collected on subjects who underwent a 5-s TASER X26 exposure or a sprint of variable distances during a law enforcement training exercise. Our results show that levels of acidosis and catecholamines are less among subjects exposed to the TASER X26 than among subjects who sprinted 20 yards or more. PMID:24314505

  17. Lactic acidosis, potassium, and the heart rate deflection point in professional road cyclists

    Lucia, A.; Hoyos, J; Santalla, A; Perez, M; Carvajal, A.; Chicharro, J.

    2002-01-01

    Objective: To determine the influence of lactic acidosis, the Bohr effect, and exercise induced hyperkalaemia on the occurrence of the heart rate deflection point (HRDP) in elite (professional) cyclists.

  18. Improving the welfare of dairy goats: Feeding behaviour identifies goats at risk of subacute rumen acidosis

    Giger-Reverdin, Sylvie; Sauvant, Daniel; Duvaux-Ponter, Christine

    2013-01-01

    Main messages: Feeding behaviour is highly variable between animals. Feeding behaviour modifies rumen pH pattern and occurrence of subacute ruminal acidosis (SARA). Avoiding SARA increases animal welfare, milk production and therefore farm profit - ability.

  19. Renal tubular acidosis presenting as respiratory paralysis: Report of a case and review of literature

    Kalita J; Nair P; Kumar G; Misra U

    2010-01-01

    Respiratory paralysis due to renal tubular acidosis (RTA) is rare. We report a 22-year-old lady who developed severe bulbar, respiratory and limb paralysis following respiratory infection. She had hypokalemia (1.6 meq/L) and hyperchloremic (110 meq/l) acidosis (pH 7.1). She was diagnosed as distal RTA by ammonium chloride test. She improved following sodium bicarbonate and potassium supplementation. RTA should be differentiated from familial periodic paralysis (FPP) because acetazolamide used...

  20. Distal renal tubular acidosis and hypokalemic paralysis in a patient with hypothyroidism

    Parvaiz Ahmad Koul; Wahid, A.

    2011-01-01

    A 43- year- old woman on treatment for primary hypothyroidism presented with 1- day progressive weakness of all her limbs and history of similar episodes in the past. Clinical examination revealed grade 2 hyporeflexive weakness. Investigations revealed features of hypokalemia, metabolic acidosis, alkaline urine, and a fractional bicarbonate excretion of 3.5%, consistent with distal renal tubular acidosis. Antithyroid peroxidase and antithroglobulin antibodies were positive, suggesting an auto...

  1. Osteomalacia complicating renal tubular acidosis in association with Sjogren's syndrome.

    El Ati, Zohra; Fatma, Lilia Ben; Boulahya, Ghada; Rais, Lamia; Krid, Madiha; Smaoui, Wided; Maiz, Hedi Ben; Beji, Soumaya; Zouaghi, Karim; Moussa, Fatma Ben

    2014-09-01

    Renal involvement in Sjogren's syndrome (SS) is not uncommon and may precede other complaints. Tubulointerstitial nephritis is the most common renal disease in SS and may lead to renal tubular acidosis (RTA), which in turn may cause osteomalacia. Nevertheless, osteomalacia rarely occurs as the first manifestation of a renal tubule disorder due to SS. We herewith describe a 43-year-old woman who was admitted to our hospital for weakness, lumbago and inability to walk. X-ray of the long bones showed extensive demineralization of the bones. Laboratory investigations revealed chronic kidney disease with serum creatinine of 2.3 mg/dL and creatinine clearance of 40 mL/min, hypokalemia (3.2 mmol/L), hypophosphatemia (0.4 mmol/L), hypocalcemia (2.14 mmol/L) and hyperchloremic metabolic acidosis (chlorine: 114 mmol/L; alkaline reserve: 14 mmol/L). The serum alkaline phosphatase levels were elevated. The serum levels of 25-hydroxyvitamin D and 1,25-dihydroxy vitamin D were low and borderline low, respectively, and the parathyroid hormone level was 70 pg/L. Urinalysis showed inappropriate alkaline urine (urinary PH: 7), glycosuria with normal blood glucose, phosphaturia and uricosuria. These values indicated the presence of both distal and proximal RTA. Our patient reported dryness of the mouth and eyes and Schirmer's test showed xerophthalmia. An accessory salivary gland biopsy showed changes corresponding to stage IV of Chisholm and Masson score. Kidney biopsy showed diffuse and severe tubulo-interstitial nephritis with dense lymphoplasmocyte infiltrates. Sicca syndrome and renal interstitial infiltrates indicated SS as the underlying cause of the RTA and osteomalacia. The patient received alkalinization, vitamin D (Sterogyl ®), calcium supplements and steroids in an initial dose of 1 mg/kg/day, tapered to 10 mg daily. The prognosis was favorable and the serum creatinine level was 1.7 mg/dL, calcium was 2.2 mmol/L and serum phosphate was 0.9 mmol/L. PMID:25193912

  2. Risk factors for mortality in children with diabetic keto acidosis from developing countries

    Varadarajan; Poovazhagi

    2014-01-01

    Diabetic keto acidosis(DKA) is the major cause for mortality in children with Diabetes mellitus(DM). With increasing incidence of type 1 DM worldwide, there is an absolute increase of DM among children between 0-14 year age group and overall incidence among less than 30 years remain the same. This shift towards younger age group is more of concern especially in developing countries where mortality in DKA is alarmingly high. Prior to the era of insulin, DKA was associated with 100% mortality and subsequently mortality rates have come down and is now, 0.15%-0.31% in developed countries. However the scenario in developing countries like India, Pakistan, and Bangladesh are very different and mortality is still high in children with DKA. Prospective studies on DKA in children are lacking in developing countries. Literature on DKA related mortality are based on retrospective studies and are very recent from countries like India, Pakistan and Bangladesh. There exists an urgent need to understand the differences between developed and developing countries with respect to mortality rates and factors associated with increased mortality in children with DKA. Higher mortality rates, increased incidence of cerebral edema, sepsis, shock and renal failure have been identified among DKA in children from developing countries.Root cause for all these complications and increased mortality in DKA could be delayed diagnosis in children from developing countries. This necessitates creating awareness among parents, public and physicians by health education to identify symptoms of DM/DKA in children, in order to decrease mortality in DKA. Based on past experience in Parma, Italy it is possible to prevent occurrence of DKA both in new onset DM and in children with established DM, by simple interventions to increase awareness among public and physicians.

  3. Distal renal tubular acidosis with multiorgan autoimmunity: a case report.

    van den Wildenberg, Maria J; Hoorn, Ewout J; Mohebbi, Nilufar; Wagner, Carsten A; Woittiez, Arend-Jan; de Vries, Peter A M; Laverman, Gozewijn D

    2015-04-01

    A 61-year-old woman with a history of pernicious anemia presented with progressive muscle weakness and dysarthria. Hypokalemic paralysis (serum potassium, 1.4 mEq/L) due to distal renal tubular acidosis (dRTA) was diagnosed. After excluding several possible causes, dRTA was considered autoimmune. However, the patient did not meet criteria for any of the autoimmune disorders classically associated with dRTA. She had very high antibody titers against parietal cells, intrinsic factor, and thyroid peroxidase (despite normal thyroid function). The patient consented to a kidney biopsy, and acid-base transporters, anion exchanger type 1 (AE1), and pendrin were undetectable by immunofluorescence. Indirect immunofluorescence detected diminished abundance of AE1- and pendrin-expressing intercalated cells in the kidney, as well as staining by the patient's serum of normal human intercalated cells and parietal cells expressing the adenosine triphosphatase hydrogen/potassium pump (H(+)/K(+)-ATPase) in normal human gastric mucosa. The dRTA likely is caused by circulating autoantibodies against intercalated cells, with possible cross-reactivity against structures containing gastric H(+)/K(+)-ATPase. This case demonstrates that in patients with dRTA without a classic autoimmune disorder, autoimmunity may still be the underlying cause. The mechanisms involved in autoantibody development and how dRTA can be caused by highly specific autoantibodies against intercalated cells have yet to be determined. PMID:25533600

  4. Pyruvate carboxylase deficiency: An underestimated cause of lactic acidosis

    F. Habarou

    2015-03-01

    Full Text Available Pyruvate carboxylase (PC is a biotin-containing mitochondrial enzyme that catalyzes the conversion of pyruvate to oxaloacetate, thereby being involved in gluconeogenesis and in energy production through replenishment of the tricarboxylic acid (TCA cycle with oxaloacetate. PC deficiency is a very rare metabolic disorder. We report on a new patient affected by the moderate form (the American type A. Diagnosis was nearly fortuitous, resulting from the revision of an initial diagnosis of mitochondrial complex IV (C IV defect. The patient presented with severe lactic acidosis and pronounced ketonuria, associated with lethargy at age 23 months. Intellectual disability was noted at this time. Amino acids in plasma and organic acids in urine did not show patterns of interest for the diagnostic work-up. In skin fibroblasts PC showed no detectable activity whereas biotinidase activity was normal. We had previously reported another patient with the severe form of PC deficiency and we show that she also had secondary C IV deficiency in fibroblasts. Different anaplerotic treatments in vivo and in vitro were tested using fibroblasts of both patients with 2 different types of PC deficiency, type A (patient 1 and type B (patient 2. Neither clinical nor biological effects in vivo and in vitro were observed using citrate, aspartate, oxoglutarate and bezafibrate. In conclusion, this case report suggests that the moderate form of PC deficiency may be underdiagnosed and illustrates the challenges raised by energetic disorders in terms of diagnostic work-up and therapeutical strategy even in a moderate form.

  5. Acidosis environment promotes osteoclast formation by acting on the last phase of preosteoclast differentiation: a study to elucidate the action points of acidosis and search for putative target molecules.

    Kato, Kohtaro; Morita, Ikuo

    2011-08-01

    Acidosis promoted tartaric acid-resistant acid phosphatase-positive multinuclear cell (TRAP+MNC) or osteoclast formation. Large osteoclast or TRAP+LMNC formation was observed far more in an acidosis environment than in a physiologically neutral environment. One of the major action points of acidosis was determined to be located in the last phase of preosteoclast differentiation using a co-culture system and a soluble RANKL-dependent bone marrow cell culture system. On-going osteoclast formation in an acidosis environment markedly deteriorated when the medium was replaced with physiologically neutral medium within the first 6h; however, bone marrow cells previously stimulated in an acidosis environment for 9h differentiated into TRAP+LMNC in pH 7.4 medium. Messenger RNA (mRNA) expression levels of DC-STAMP, a key molecule in cell fusion, and NFATc1 did not increase in the acidosis environment compared with those under physiologically neutral conditions. Ruthenium red, a general TRP antagonist, deteriorated acidosis-promoted TRAP+LMNC formation. 4-Alpha-PDD, a TRPV4-specific agonist, added in the last 21 h of preosteoclast differentiation, potentiated TRAP+LMNC formation in a mild acidosis environment, showing synergism between TRPV4 activation and acidosis. RN1734, a TRPV4-specific antagonist, partly inhibited acidosis-promoted TRAP+LMNC formation. We thus narrowed down the major action points of acidosis in osteoclast formation and elucidated the characteristics of this system in detail. Our results show that acidosis effectively uses TRPV4 to drive large-scale cell fusion and also utilizes systems independently of TRPV4. PMID:21575626

  6. A Rare Case of Type I RenalTubular Acidosis with Membranous Nephropathy Presenting as Hypokalemic Paralysis

    Sunder, Sham; Sathi, Satyanand; K Venkataramanan; Verma, Himanshu; Bhardwaj, Minakshi; Rajesh, J.; Mahapatra, Himanshu

    2013-01-01

    Type 1 renal tubular acidosis (RTA), or distal RTA (dRTA), is a disorder of renal tubular acidification, which is generally asymptomatic but may rarely present as hypokalemic paralysis. Here, we report the case of a young male who presented with sudden onset weakness of all 4 limbs and a 2-month history of swelling of the legs. An investigation revealed hypokalemia, metabolic acidosis, and nephrotic syndrome. Additional analyses revealed normal anion gap metabolic acidosis with a positive uri...

  7. Delayed discharge.

    Allen, Daniel

    2016-07-01

    Essential facts Delays in discharging older peo ple from hospital cost the NHS £820 million a year, according to a report from the National Audit Office (NAO). Last year in acute hospitals, 1.15 million bed days were lost to delayed transfers of care, an increase of 31% since 2013. The NAO says rising demand for NHS services is compounded by reduced local authority spending on adult social care - down by 10% since 2009-10. PMID:27380673

  8. Effect of sodium bicarbonate administration on mortality in patients with lactic acidosis: a retrospective analysis.

    Hyun Jeong Kim

    Full Text Available BACKGROUND: Lactic acidosis is a common cause of high anion gap metabolic acidosis. Sodium bicarbonate may be considered for an arterial pH <7.15 but paradoxically depresses cardiac performance and exacerbates acidosis by enhancing lactate production. This study aimed to evaluate the cause and mortality rate of lactic acidosis and to investigate the effect of factors, including sodium bicarbonate use, on death. METHODS: We conducted a single center analysis from May 2011 through April 2012. We retrospectively analyzed 103 patients with lactic acidosis among 207 patients with metabolic acidosis. We used SOFA and APACHE II as severity scores to estimate illness severity. Multivariate logistic regression analysis and Cox regression analysis models were used to identify factors that affect mortality. RESULTS: Of the 103 patients with a mean age of 66.1±11.4 years, eighty-three patients (80.6% died from sepsis (61.4%, hepatic failure, cardiogenic shock and other causes. The percentage of sodium bicarbonate administration (p = 0.006, catecholamine use, ventilator care and male gender were higher in the non-survival group than the survival group. The non-survival group had significantly higher initial and follow-up lactic acid levels, lower initial albumin, higher SOFA scores and APACHE II scores than the survival group. The mortality rate was significantly higher in patients who received sodium bicarbonate. Sodium bicarbonate administration (p = 0.016 was associated with higher mortality. Independent factors that affected mortality were SOFA score (Exp (B = 1.72, 95% CI = 1.12-2.63, p = 0.013 and sodium bicarbonate administration (Exp (B = 6.27, 95% CI = 1.10-35.78, p = 0.039. CONCLUSIONS: Lactic acidosis, which has a high mortality rate, should be evaluated in patients with metabolic acidosis. In addition, sodium bicarbonate should be prescribed with caution in the case of lactic acidosis because sodium bicarbonate

  9. Reversible lactic acidosis in a newborn with thiamine transporter-2 deficiency.

    Pérez-Dueñas, Belén; Serrano, Mercedes; Rebollo, Mónica; Muchart, Jordi; Gargallo, Eva; Dupuits, Celine; Artuch, Rafael

    2013-05-01

    Thiamine transporter-2 deficiency is a recessive disease caused by mutations in the SLC19A3 gene. Patients manifest acute episodes of encephalopathy; symmetric lesions in the cortex, basal ganglia, thalami or periaqueductal gray matter, and a dramatic response to biotin or thiamine. We report a 30-day-old patient with mutations in the SLC19A3 gene who presented with acute encephalopathy and increased level of lactate in the blood (8.6 mmol/L) and cerebrospinal fluid (7.12 mmol/L), a high excretion of α-ketoglutarate in the urine, and increased concentrations of the branched-chain amino acids leucine and isoleucine in the plasma. MRI detected bilateral and symmetric cortico-subcortical lesions involving the perirolandic area, bilateral putamina, and medial thalami. Some lesions showed low apparent diffusion coefficient values suggesting an acute evolution; others had high values likely to be subacute or chronic, most likely related to the perinatal period. After treatment with thiamine and biotin, irritability and opisthotonus disappeared, and the patient recovered consciousness. Biochemical disturbances also disappeared within 48 hours. After discontinuing biotin, the patient remained stable for 6 months on thiamine supplementation (20 mg/kg/day). The examination revealed subtle signs of neurologic sequelae, and MRI showed necrotic changes and volume loss in some affected areas. Our observations suggest that patients with thiamine transporter 2 deficiency may be vulnerable to metabolic decompensation during the perinatal period, when energy demands are high. Thiamine defects should be excluded in newborns and infants with lactic acidosis because prognosis largely depends on the time from diagnosis to thiamine supplementation. PMID:23589815

  10. Haptoglobin and serum amyloid a in subacute ruminal acidosis in goats

    F.H.D. González

    2010-12-01

    Full Text Available Ruminal acidosis is a frequent disorder that occurs in goats as a consequence of feedingmistakes in animals not adapted to a diet of easily fermentable carbohydrates. The subacuteform of the disease is difficult to diagnose because no apparent signs are shownand the acid-base parameters may remain within the normal range. The present studyaimed at testing the hypothesis that haptoglobin (Hp and serum amyloid A (SAA,the two major acute phase proteins in ruminants, may be useful as markers of subacuteacidosis in goats.A subacute acidosis was induced in six Murciano-Granadina goats through a diet of60% mixed feed-40% alfalfa hay offered during 5 days to goats not adapted to eatmixed feed. Two goats were rumen-fistulated to investigate the effect of feeding onruminal pH. Sampling of blood and urine of all animals was done before the inductionof the acidosis, during 5 days after the onset of induction and for 18 days after theinduction (recovery period.Ruminal pH in the fistulated goats dropped to less than 5.5 during the inductionperiod, and half of the goats had diarrhea on the third day after the induction of acidosis.Acid-base parameters showed that the acid-base compensatory mechanisms wereefficient in maintaining the equilibrium. Serum Hp had a moderate increase duringthe induction period, while SAA did not change. These results suggest that Hp mightbe a potential marker for ruminal acidosis in goats.

  11. Acidosis láctica por metformina desencadenada por una insuficiencia renal aguda Metformin-induced lactic acidosis due to acute renal failure

    M.D. Macías-Robles

    2011-04-01

    Full Text Available La acidosis láctica es una complicación grave pero infrecuente asociada al empleo de metformina. Se discuten los mecanismos fisiopatológicos implicados en la acidosis láctica, con especial atención al papel potencial del fármaco. Presentamos un caso severo de este efecto secundario de la metformina en una paciente con diabetes tipo 2 que ingresó en el Servicio de Urgencias Hospitalario por un cuadro de insuficiencia renal aguda. El diagnóstico quedó apoyado por unos niveles séricos elevados de la biguanida, procedimiento escasamente utilizado en la práctica clínica. El tratamiento consiste en suspender la administración del fármaco e iniciar de forma inmediata la hemodiálisis con bicarbonato, lo cual proporciona un tratamiento sintomático y etiológico al eliminar del suero tanto el lactato como el antidiabético oral. Los síntomas de la acidosis láctica por metformina son inespecíficos y el comienzo es sutil, lo que hace necesario un alto nivel de sospecha para establecer un diagnostico precoz.Lactic acidosis is a serious but uncommon side effect of metformin use. We discuss the pathophysiological mechanisms of lactic acidosis with particular regard to the role played by the drug as a potential cause of the entity. We report on a severe case of this kind of drug toxicity in a patient with type 2 diabetes mellitus, admitted to the emergency department with acute renal failure symptoms. The diagnosis was supported by elevated serum levels of the biguanide, a procedure scarcely used in clinical practice. The management of this complication consists in drug discontinuation and hemodialysis with bicarbonate that provides symptomatic and ethiological treatment by removing both the lactate and the hypoglycemic agent from the serum. Since the symptoms of metformin-associated lactic acidosis are unspecific and its onset is subtle, a high level of suspicion is needed to establish an early diagnosis.

  12. Hypokalemic periodic paralysis in Sjogren's syndrome secondary to distal renal tubular acidosis.

    Yılmaz, Hakkı; Kaya, Mustafa; Özbek, Mustafa; ÜUreten, Kemal; Safa Yıldırım, İ

    2013-07-01

    We report a 53-year-old Turkish female presented with progressive weakness and mild dyspnea. Laboratory results demonstrated severe hypokalemia with hyperchloremic metabolic acidosis. The urinary anion gap was positive in the presence of acidemia, thus she was diagnosed with hypokalemic paralysis from a severe distal renal tubular acidosis (RTA). Immunologic work-up showed a strongly positive ANA of 1:3,200 and positive antibodies to SSA and SSB. Schirmer's test was abnormal. Autoimmune and other tests revealed Sjögren syndrome as the underlying cause of the distal renal tubular acidosis. Renal involvement in Sjogren's syndrome (SS) is not uncommon and may precede sicca complaints. The pathology in most cases is a tubulointerstitial nephritis causing among other things, distal RTA, and, rarely, hypokalemic paralysis. Treatment consists of potassium repletion, alkali therapy, and corticosteroids. Primary SS could be a differential in women with acute weakness and hypokalemia. PMID:22212410

  13. Trimethoprim/Sulfamethoxazole-Induced Severe Lactic Acidosis: A Case Report and Review of the Literature.

    Bulathsinghala, Marie; Keefer, Kimberly; Van de Louw, Andry

    2016-04-01

    Propylene glycol (PG) is used as a solvent in numerous medications, including trimethoprim/sulfamethoxazole (TMP/SMX) and lorazepam, and is metabolized in the liver to lactic acid. Cases of lactic acidosis related to PG toxicity have been described and always involved large doses of benzodiazepines and PG. We present the first case of severe lactic acidosis after a 3-day course of TMP/SMX alone, involving allegedly safe amounts of PG.A 31-year-old female with neurofibromatosis and pilocytic astrocytoma, receiving temozolomide and steroids, was admitted to the intensive care unit for pneumonia and acute respiratory failure requiring intubation. Her initial hemodynamic and acid-base statuses were normal. She was treated with intravenous TMP/SMX for possible Pneumocystis jirovecii pneumonia and was successfully extubated on day 2. On day 3, she developed tachypnea and arterial blood gas analysis revealed a severe metabolic acidosis (pH 7.2, PCO2 19 mm Hg, bicarbonates 8 mEq/L) with anion gap of 25 mEq/L and lactate of 12.1 mmol/L. TMP/SMX was discontinued and the lactate decreased to 2.9 mmol/L within 24 hours while her plasma bicarbonates normalized, without additional intervention. The patient never developed hypotension or severe hypoxia, and her renal and liver functions were normal. No other cause for lactic acidosis was identified and it resolved after TMP/SMX cessation alone, suggesting PG toxicity.Although PG-related lactic acidosis is well recognized after large doses of lorazepam, clinicians should bear in mind that TMP/SMX contains PG as well and should suspect PG toxicity in patients developing unexplained metabolic acidosis while receiving TMP/SMX. PMID:27124045

  14. Renal Tubular Acidosis after Jejunoileal Bypass for Morbid Obesity: role of secondary hyperparathyroidism

    Andersen, NN; Ladefoged, NN

    1991-01-01

    The effect of calcium infusion was studied in patients with renal tubular acidosis (RTA) and secondary hyperparathyroidism. Both developed after jejunoileal bypass operation (JIB) for morbid obesity. In three of four cases the acidification defect was abolished, probably due to a decrease of serum...... parathyroid hormone. As we found RTA in 9% (95% confidence limits 2-21%) of our patients, screening for acidosis is recommended in obesity patients after malabsorptive operations. RTA can be verified through an ammonium loading test. Before deciding on re-establishing bowel continuity due to RTA, we suggest...

  15. Indomethacin abolishes cerebral blood flow increase in response to acetazolamide-induced extracellular acidosis

    Wang, Qian; Paulson, O B; Lassen, N A

    1993-01-01

    by acetazolamide (Az), a drug that induces brain extracellular acidosis, which triggers its effect on CBF. We compared the results to the inhibitory effect of indomethacin on the CBF increase during hypercapnia. Indomethacin but not diclofenac, another potent cyclooxygenase inhibitor, was found to...... block almost completely the CBF increase caused by Az-induced extracellular acidosis or by CO2, but it did not influence the CBF increase produced by sodium nitroprusside or papaverine. The results suggest that indomethacin exerts its action on CO2 reactivity by a nonprostaglandin-mediated mechanism...

  16. Distal renal tubular acidosis and hypokalemic paralysis in a patient with hypothyroidism

    Parvaiz Ahmad Koul

    2011-01-01

    Full Text Available A 43- year- old woman on treatment for primary hypothyroidism presented with 1- day progressive weakness of all her limbs and history of similar episodes in the past. Clinical examination revealed grade 2 hyporeflexive weakness. Investigations revealed features of hypokalemia, metabolic acidosis, alkaline urine, and a fractional bicarbonate excretion of 3.5%, consistent with distal renal tubular acidosis. Antithyroid peroxidase and antithroglobulin antibodies were positive, suggesting an autoimmune basis for the pathogenesis of the functional tubular defect. Bicarbonate therapy resulted in a sustained clinical recovery.

  17. Renal tubular acidosis presenting as respiratory paralysis: Report of a case and review of literature

    Kalita J

    2010-01-01

    Full Text Available Respiratory paralysis due to renal tubular acidosis (RTA is rare. We report a 22-year-old lady who developed severe bulbar, respiratory and limb paralysis following respiratory infection. She had hypokalemia (1.6 meq/L and hyperchloremic (110 meq/l acidosis (pH 7.1. She was diagnosed as distal RTA by ammonium chloride test. She improved following sodium bicarbonate and potassium supplementation. RTA should be differentiated from familial periodic paralysis (FPP because acetazolamide used in FPP aggravates RTA and sodium bicarbonate used in RTA aggravates hypokalemic periodic paralysis.

  18. Distal renal tubular acidosis and hypokalemic paralysis in a patient with hypothyroidism.

    Koul, Parvaiz Ahmad; Wahid, A

    2011-09-01

    A 43- year- old woman on treatment for primary hypothyroidism presented with 1- day progressive weakness of all her limbs and history of similar episodes in the past. Clinical examination revealed grade 2 hyporeflexive weakness. Investigations revealed features of hypokalemia, metabolic acidosis, alkaline urine, and a fractional bicarbonate excretion of 3.5%, consistent with distal renal tubular acidosis. Antithyroid peroxidase and antithroglobulin antibodies were positive, suggesting an autoimmune basis for the pathogenesis of the functional tubular defect. Bicarbonate therapy resulted in a sustained clinical recovery. PMID:21912036

  19. Identification of neonatal near miss by systematic screening for metabolic acidosis at birth

    Bonnaerens, A.; Thaens, A.; Mesens, T.; Van Holsbeke, C; E. T. M. de Jonge; Gyselaers, Wilfried

    2011-01-01

    Aims: To evaluate the relevance of systematic screening for neonatal metabolic acidosis at birth as part of perinatal audit. Methods: For every baby, born in Ziekenhuis Oost Limburg, Genk Belgium between 1/1/2010 and 31/12/2010, cord blood was analysed to diagnose metabolic acidosis, defined as arterial or venous pH ≤ 7.05 or 7.17 respectively, in association with base excess of ≤ -10 mmol/L. Three observers identified indicators for suboptimal peripartal care with likely contribution to ...

  20. Calcium citrate improves the epithelial-to-mesenchymal transition induced by acidosis in proximal tubular cells

    Maria José Rodriguez Cabalgante; Liliana Gadola; Leonella Luzardo; María Márquez; José Boggia; Mirian Aparecida Boim

    2012-01-01

    INTRODUCTION: Epithelial-to-mesenchymal transition (EMT) is a key event in renal fibrosis. The aims of the study were to evaluate acidosis induced EMT, transforming-growth-factor (TGF) β1 role and citrate effect on it. METHODS: HK2 cells (ATCC 2290) were cultured in DMEM/HAM F12 medium, pH 7.4. At 80% confluence, after 24 hr under serum free conditions, cells were distributed in three groups (24 hours): A) Control: pH 7.4, B) Acidosis: pH 7.0 and C) Calcium citrate (0.2 mmol/L) + pH 7.0. Chan...

  1. [Gastric emptying and metabolic acidosis. III. Study of gastric retention of a sodium citrate solution using an experimental model of metabolic acidosis in rats].

    Baracat, E C; Collares, E F

    1992-01-01

    The gastric emptying of sodium citrate solution 0.25 mEq/ml was studied in rats with metabolic acidosis induced by orogastric infusion of 0.5 M ammonium chloride solution. Two control groups were used: one infused with 0.5 M sodium chloride and the other with water. The 3 solutions content was 2 ml/100 g weight of the animal. Six hours after the infusion, there was a moderate metabolic acidosis in the group with ammonium citrate. This 6 hour interval marked the beginning of the gastric emptying study. The test meal (sodium citrate 0.25 mEq/ml) was utilized containing 6 mg% red fenol as a marker. The gastric emptying of sodium citrate was studied at 5, 10, 20 and 30 minutes after the infusion, and the results showed no differences between the 3 groups. The data suggest that the duodenal receptors to pH were more effective do determine the pattern of gastric response than the acidosis. PMID:1339143

  2. Delayed privatization

    Bernardo Bortolotti; Paolo Pinotti

    2008-01-01

    This paper studies the timing of privatization in 21 major developed economies in the 1977-2002 period. Duration analysis shows that political fragmentation plays a significant role in explaining government's decision to privatize: privatization is delayed longer in democracies characterized by a larger number of parties and operating under proportional electoral rules, as predicted by war of attrition models of economic reform. Results are robust to various assumptions on the underlying stat...

  3. Scalp blood lactate for intra-partum assessment of fetal metabolic acidosis

    Heinis, A.M.; Spaanderman, M.E.A.; Gunnewiek, J.M.; Lotgering, F.K.

    2011-01-01

    Objective. To study to what extent the fetal scalp blood lactate concentration during labor correlates with fetal scalp pH and base deficit, and metabolic acidosis at birth, and to suggest lactate cut-off values to serve as indicators for either reassurance or immediate intervention. Design. A retro

  4. Tumour-specific metabolic adaptation to acidosis is coupled to epigenetic stability in osteosarcoma cells.

    Chano, Tokuhiro; Avnet, Sofia; Kusuzaki, Katsuyuki; Bonuccelli, Gloria; Sonveaux, Pierre; Rotili, Dante; Mai, Antonello; Baldini, Nicola

    2016-01-01

    The glycolytic-based metabolism of cancers promotes an acidic microenvironment that is responsible for increased aggressiveness. However, the effects of acidosis on tumour metabolism have been almost unexplored. By using capillary electrophoresis with time-of-flight mass spectrometry, we observed a significant metabolic difference associated with glycolysis repression (dihydroxyacetone phosphate), increase of amino acid catabolism (phosphocreatine and glutamate) and urea cycle enhancement (arginino succinic acid) in osteosarcoma (OS) cells compared with normal fibroblasts. Noteworthy, metabolites associated with chromatin modification, like UDP-glucose and N(8)-acetylspermidine, decreased more in OS cells than in fibroblasts. COBRA assay and acetyl-H3 immunoblotting indicated an epigenetic stability in OS cells than in normal cells, and OS cells were more sensitive to an HDAC inhibitor under acidosis than under neutral pH. Since our data suggest that acidosis promotes a metabolic reprogramming that can contribute to the epigenetic maintenance under acidosis only in tumour cells, the acidic microenvironment should be considered for future therapies. PMID:27186436

  5. Severity and Nature of Acidosis in Diarrheic Calves Over and Under One Week of Age

    Naylor, Jonathan M.

    1987-01-01

    A prospective study of the severity of dehydration and acidosis was carried out in 42 calves under 35 days of age presented for treatment of neonatal diarrhea. Clinically the mean level of dehydration was 8 to 10%. The plasma volume was 65% of that in the hydrated calf but the calves only gained 6.5% in weight during therapy.

  6. Tumour-specific metabolic adaptation to acidosis is coupled to epigenetic stability in osteosarcoma cells

    Chano, Tokuhiro; Avnet, Sofia; Kusuzaki, Katsuyuki; Bonuccelli, Gloria; Sonveaux, Pierre; Rotili, Dante; Mai, Antonello; Baldini, Nicola

    2016-01-01

    The glycolytic-based metabolism of cancers promotes an acidic microenvironment that is responsible for increased aggressiveness. However, the effects of acidosis on tumour metabolism have been almost unexplored. By using capillary electrophoresis with time-of-flight mass spectrometry, we observed a significant metabolic difference associated with glycolysis repression (dihydroxyacetone phosphate), increase of amino acid catabolism (phosphocreatine and glutamate) and urea cycle enhancement (arginino succinic acid) in osteosarcoma (OS) cells compared with normal fibroblasts. Noteworthy, metabolites associated with chromatin modification, like UDP-glucose and N8-acetylspermidine, decreased more in OS cells than in fibroblasts. COBRA assay and acetyl-H3 immunoblotting indicated an epigenetic stability in OS cells than in normal cells, and OS cells were more sensitive to an HDAC inhibitor under acidosis than under neutral pH. Since our data suggest that acidosis promotes a metabolic reprogramming that can contribute to the epigenetic maintenance under acidosis only in tumour cells, the acidic microenvironment should be considered for future therapies. PMID:27186436

  7. Lactic acidosis occurrence during exercises in the smoke chamber in a 53-year-old firefighter with no significant medical history

    Agata Bronisz

    2014-04-01

    Full Text Available Lactic acidosis is a form of metabolic acidosis with a high anion gap, reduced rate of arterial blood pH under 7.35 mmol/l, and lactic acid concentration over 7 mmol/l. In the literature we can find some descriptions of the cases of lactic acidosis in patients with severe systemic diseases (cancer, acquired immunodeficiency syndrome, sepsis, diabetes with cardiovascular disease and after organ transplantations. We present the case of lactic acidosis in a patient with no chronic disease - a firefighter in whom lactic acidosis has developed during standard exercises in the smoke chamber.

  8. [Distal renal tubular acidosis: report of 3 cases].

    Guibaud, P; Parchoux, B; Langue, J; Bouissou, F; Barthe, P; Larbre, F

    1979-06-01

    Three observations of R.T.A. with nerve deafness are reported. Case 1 and 2 concern consanguinous brothers whose parents are not affected, which confirm the syndrom as an autosomal recessive entity. The third, sporadic, case relates to a 13-year-old non consanguinous girl. Metabolic abnormalities and renal evolution with nephrocalcinosis was such as in Albright disease. However a progressive nerve deafness makes distinction. The authors underline the importance of this sometimes difficult distinction for genetic counseling. PMID:541679

  9. Diffusion and Perfusion Characteristics of MELAS (Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-Like Episode) in Thirteen Patients

    We analyzed the diffusion and perfusion characteristics of acute MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episode) lesions in a large series to investigate the controversial changes of the apparent diffusion coefficient (ADC) that were reported in prior studies. We analyzed 44 newly appearing lesions during 28 stroke-like episodes in 13 patients with MELAS. We performed a visual assessment of the MR images including the ADC and perfusion maps, comparison of the ADC between the normal and abnormal areas, comparison of % ADC between the 44 MELAS lesions and the 30 acute ischemic infarcts. In addition, the patterns of evolution on follow-up MR images were analyzed. Decreased, increased, and normal ADCs were noted in 16 (36%), 16 (36%), and 12 (27%) lesions, respectively. The mean % ADC was 102 ± 40.9% in the MELAS and 64 ± 17.8% in the acute vascular infarcts (p < 0.001), while perfusion imaging demonstrated hyper-perfusion in six acute MELAS lesions. On follow-up images, resolution, progression, and tissue loss were noted in 10, 4, and 17 lesions, respectively. The cytotoxic edema gradually evolves following an acute stroke-like episode in patients with MELAS, and this may overlap with hyper-perfusion and vasogenic edema. The edematous swelling may be reversible or it may evolve to encephalomalacia, suggesting irreversible damage

  10. Audio Modeling based on Delayed Sinusoids

    Boyer, Remy; Abed-Meraim, Karim

    2004-01-01

    In this work, we present an evolution of the DDS (Damped & Delayed Sinusoidal) model introduced within the framework of the general signal modeling. This model is named the Partial Damped & Delayed Sinusoidal (PDDS) model and takes into account a single time delay parameter for a set (sum) of damped sinusoids. This modi- ¯cation is more consistent with the transient audio modeling problem. We show the validity of this approach by compari- son with the well-known EDS (Exponentially Damped Sinu...

  11. Construction and validation of a decision tree for treating metabolic acidosis in calves with neonatal diarrhea

    Trefz Florian M

    2012-12-01

    Full Text Available Abstract Background The aim of the present prospective study was to investigate whether a decision tree based on basic clinical signs could be used to determine the treatment of metabolic acidosis in calves successfully without expensive laboratory equipment. A total of 121 calves with a diagnosis of neonatal diarrhea admitted to a veterinary teaching hospital were included in the study. The dosages of sodium bicarbonate administered followed simple guidelines based on the results of a previous retrospective analysis. Calves that were neither dehydrated nor assumed to be acidemic received an oral electrolyte solution. In cases in which intravenous correction of acidosis and/or dehydration was deemed necessary, the provided amount of sodium bicarbonate ranged from 250 to 750 mmol (depending on alterations in posture and infusion volumes from 1 to 6.25 liters (depending on the degree of dehydration. Individual body weights of calves were disregarded. During the 24 hour study period the investigator was blinded to all laboratory findings. Results After being lifted, many calves were able to stand despite base excess levels below −20 mmol/l. Especially in those calves, metabolic acidosis was undercorrected with the provided amount of 500 mmol sodium bicarbonate, which was intended for calves standing insecurely. In 13 calves metabolic acidosis was not treated successfully as defined by an expected treatment failure or a measured base excess value below −5 mmol/l. By contrast, 24 hours after the initiation of therapy, a metabolic alkalosis was present in 55 calves (base excess levels above +5 mmol/l. However, the clinical status was not affected significantly by the metabolic alkalosis. Conclusions Assuming re-evaluation of the calf after 24 hours, the tested decision tree can be recommended for the use in field practice with minor modifications. Calves that stand insecurely and are not able to correct their position if pushed

  12. The acidosis-induced right shift of the HbO2 dissociation curve is maintained during erythrocyte storage

    Opdahl, Helge; Strømme, Tæwje A; Jørgensen, Lise; Bajelan, Livia; Heier, Hans E

    2011-01-01

    Background and objectives . In fresh blood, tissue hypoxia increases microcirculatory acidosis, which enhances erythrocyte O2 unloading and increases the amount of available O2. Storage of eryfhrocytes increases the HbO2 affinity and reduces O2 unloading. We examined the development of the affinity change during a period of 5 weeks of storage by present blood bank standards, and investigated to what extent acidosis offsets the affinity change. Materials and methods . Blood from volunteer dono...

  13. Rumen microbial and fermentation characteristics are affected differently by bacterial probiotic supplementation during induced lactic and subacute acidosis in sheep

    Lettat Abderzak

    2012-07-01

    Full Text Available Abstract Background Ruminal disbiosis induced by feeding is the cause of ruminal acidosis, a digestive disorder prevalent in high-producing ruminants. Because probiotic microorganisms can modulate the gastrointestinal microbiota, propionibacteria- and lactobacilli-based probiotics were tested for their effectiveness in preventing different forms of acidosis. Results Lactic acidosis, butyric and propionic subacute ruminal acidosis (SARA were induced by feed chalenges in three groups of four wethers intraruminally dosed with wheat, corn or beet pulp. In each group, wethers were either not supplemented (C or supplemented with Propionibacterium P63 alone (P or combined with L. plantarum (Lp + P or L. rhamnosus (Lr + P. Compared with C, all the probiotics stimulated lactobacilli proliferation, which reached up to 25% of total bacteria during wheat-induced lactic acidosis. This induced a large increase in lactate concentration, which decreased ruminal pH. During the corn-induced butyric SARA, Lp + P decreased Prevotella spp. proportion with a concomitant decrease in microbial amylase activity and total volatile fatty acids concentration, and an increase in xylanase activity and pH. Relative to the beet pulp-induced propionic SARA, P and Lr + P improved ruminal pH without affecting the microbial or fermentation characteristics. Regardless of acidosis type, denaturing gradient gel electrophoresis revealed that probiotic supplementations modified the bacterial community structure. Conclusion This work showed that the effectiveness of the bacterial probiotics tested depended on the acidosis type. Although these probiotics were ineffective in lactic acidosis because of a deeply disturbed rumen microbiota, some of the probiotics tested may be useful to minimize the occurrence of butyric and propionic SARA in sheep. However, their modes of action need to be further investigated.

  14. A Rare Cause of Metabolic Acidosis: Fatal Transdermal Methanol Intoxication in an Infant.

    Sahbudak Bal, Zumrut; Can, Fulya Kamit; Anil, Ayse Berna; Bal, Alkan; Anil, Murat; Gokalp, Gamze; Yavascan, Onder; Aksu, Nejat

    2016-08-01

    Oral methanol intoxication is common, but dermal intoxication is rare. We report a previously healthy 19-month-old female infant admitted to the emergency department (ED) with vomiting and tonic-clonic seizure. On physical examination, she was comatose and presented signs of decompensated shock with Kussmaul breathing. Her left thigh was edematous, with purple coloration. Methanol intoxication was suspected due to high anion gap metabolic acidosis (pH, 6.89; HCO3, occipital lobe were detected by computed tomography of the brain. The patient died after 7 days.Although methanol intoxication occurs predominantly in adults, it must be considered in children with high-anion gap metabolic acidosis. This case report demonstrates that fatal transdermal methanol intoxication can occur in children, and it is the second report in the English literature of transdermal methanol intoxication in an infant. PMID:26196361

  15. Alteration in Fecal Microbiota Associated with Grain-induced Subacute Ruminal Acidosis Challenge in Dairy Cows

    Danscher, Anne Mette; Derakshani, Hooman; Li, Shucong;

    2014-01-01

    Introduction: High prevalence of subacute rumen acidosis (SARA) in dairy herds has been reported with large impact on production and welfare. The field diagnosis of SARA is currently unclear and primarily based on point measurements of rumen pH, which are inaccurate. Consequently, SARA cases in t...... markers of the disease. bovine, subacute ruminal acidosis, fecal microbiome, biological marker Host publication information...... field are often not detected. Thus, other and better markers of SARA are needed. The purpose of this research was to study the feces microbiome during SARA and assess the possibilities of using feces microbial markers as indicators of SARA. Methods: Six lactating, rumen cannulated, Danish Holstein cows...... predictive value was estimated to R2: 87.0 and Q2: 73.2, respectively. Conclusion: Results confirm that intensive grain feeding changes the feces microbiome. The identification of specific taxa characteristic of SARA could provide new knowledge of the pathogenesis and might be useful as future biological...

  16. Rapid Revival of a Patient after very Severe Metabolic Acidosis: A Case Report

    Sajad Ahmadi

    2013-01-01

    Full Text Available Background: Metabolic acidosis is a fatal finding in trauma patients thatcomplicates the process of resuscitation.Case: The case was a 37-year-old man with open fracture in both legs and fracturein second lumbar vertebral (L2. The serial arterial blood gas (ABG test resultsshowed a pH value of 6.7 indicating a very severe and special case of metabolicacidosis. The rate of mortality for such a case was very high. The patient wastreated with sodium bicarbonate and successfully revived after four hours posttreatment and metabolic acidosis was resolved.Conclusion: This indicated that bicarbonate administration is useful for verysevere cases. The good condition of the patient after survival from the severeacademia allowed for extubation.

  17. Hyperchloremic Metabolic Acidosis due to Cholestyramine: A Case Report and Literature Review.

    Kamar, Fareed B; McQuillan, Rory F

    2015-01-01

    Cholestyramine is a bile acid sequestrant that has been used in the treatment of hypercholesterolemia, pruritus due to elevated bile acid levels, and diarrhea due to bile acid malabsorption. This medication can rarely cause hyperchloremic nonanion gap metabolic acidosis, a complication featured in this report of an adult male with concomitant acute kidney injury. This case emphasizes the caution that must be taken in prescribing cholestyramine to patients who may also be volume depleted, in renal failure, or taking spironolactone. PMID:26425378

  18. Muscle oxidative metabolism accelerates with mild acidosis during incremental intermittent isometric plantar flexion exercise

    Homma, Toshiyuki; Hamaoka, Takafumi; Sako, Takayuki; Murakami, Motohide; Esaki, Kazuki; Kime, Ryotaro; Katsumura, Toshihito

    2005-01-01

    Background It has been thought that intramuscular ADP and phosphocreatine (PCr) concentrations are important regulators of mitochondorial respiration. There is a threshold work rate or metabolic rate for cellular acidosis, and the decrease in muscle PCr is accelerated with drop in pH during incremental exercise. We tested the hypothesis that increase in muscle oxygen consumption (o2mus) is accelerated with rapid decrease in PCr (concomitant increase in ADP) in muscles with drop in pH occurs d...

  19. Cleistanthus collinus induces type I distal renal tubular acidosis and type II respiratory failure in rats

    Maneksh, Delinda; Sidharthan, Anita; Kettimuthu, Kavithapriya; Kanthakumar, Praghalathan; Lourthuraj, Amala A.; Ramachandran, Anup; Subramani, Sathya

    2010-01-01

    Background and Purpose: A water decoction of the poisonous shrub Cleistanthus collinus is used for suicidal purposes. The mortality rate is 28%. The clinical profile includes distal renal tubular acidosis (DRTA) and respiratory failure. The mechanism of toxicity is unclear. Objectives: To demonstrate features of C. collinus toxicity in a rat model and to identify its mechanism(s) of action. Materials and Methods: Rats were anesthetized and the carotid artery was cannulated. Electrocardiogram ...

  20. Dermal bone in early tetrapods: a palaeophysiological hypothesis of adaptation for terrestrial acidosis

    Janis, Christine M.; Devlin, Kelly; Warren, Daniel E.; Witzmann, Florian

    2012-01-01

    The dermal bone sculpture of early, basal tetrapods of the Permo-Carboniferous is unlike the bone surface of any living vertebrate, and its function has long been obscure. Drawing from physiological studies of extant tetrapods, where dermal bone or other calcified tissues aid in regulating acid–base balance relating to hypercapnia (excess blood carbon dioxide) and/or lactate acidosis, we propose a similar function for these sculptured dermal bones in early tetrapods. Unlike the condition in m...

  1. Sjögren’s, Renal Tubular Acidosis And Osteomalacia - An Asian Indian Series

    Sandhya, Pulukool; Danda, Debashish; Rajaratnam, Simon; Thomas, Nihal

    2014-01-01

    Objective: To study the profile of Renal Tubular Acidosis (RTA) in Asian Indian patients with Primary Sjögren's Syndrome (pSS). Methods: The Electronic medical records of patients with a diagnosis of pSS seen between 2003 and 2010 at our tertiary care teaching hospital were screened for RTA. Clinical features, immunological profile, acid-base balance and electrolyte status, 25-hydroxyvitamin D (25(OH) D3) levels, histopathological changes in minor salivary gland biopsy samples and radiologica...

  2. Multiplexed Microneedle-based Biosensor Array for Characterization of Metabolic Acidosis

    Miller, Philip R; Skoog, Shelby A.; Edwards, Thayne L.; Lopez, DeAnna M.; David R. Wheeler; Dulce C Arango; Xiao, Xiaoyin; Brozik, Susan M.; Wang, Joseph; Polsky, Ronen; Roger J. Narayan

    2011-01-01

    The development of a microneedle-based biosensor array for multiplexed in situ detection of exercise-induced metabolic acidosis, tumor microenvironment, and other variations in tissue chemistry is described. Simultaneous and selective amperometric detection of pH, glucose, and lactate over a range of physiologically-relevant concentrations in complex media is demonstrated. Furthermore, materials modified with a cell-resistant (Lipidure®) coating were shown to inhibit macrophage adhesion; no s...

  3. Fluoxetine Treatment Abolishes the In Vitro Respiratory Response to Acidosis in Neonatal Mice

    Voituron, Nicolas; Shvarev, Yuri; Menuet, Clément; Bevengut, Michelle; Fasano, Caroline; Vigneault, Erika; Mestikawy, Salah El; Hilaire, Gérard

    2010-01-01

    Background To secure pH homeostasis, the central respiratory network must permanently adapt its rhythmic motor drive to environment and behaviour. In neonates, it is commonly admitted that the retrotrapezoid/parafacial respiratory group of neurons of the ventral medulla plays the primary role in the respiratory response to acidosis, although the serotonergic system may also contribute to this response. Methodology/Principal Findings Using en bloc medullary preparations from neonatal mice, we ...

  4. Hearing impairment in association with distal renal tubular acidosis among Saudi children.

    Zakzouk, S M; Sobki, S H; Mansour, F; al Anazy, F H

    1995-10-01

    A follow-up of seven patients with the autosomal recessive inherited syndrome of distal renal tubular acidosis (RTA) and sensorineural hearing loss is described. Five patients were diagnosed as having primary distal renal tubular acidosis and rickets, four were found to have severe sensorineural hearing loss of over 80 dB: two of which are brothers. Two patients were diagnosed as having secondary distal renal acidosis due to a genetic disorder called osteopetrosis; they are brothers and their audiograms showed a mild conductive hearing loss of an average 35 dB bilaterally. All patients had growth retardation with improvement due to alkaline therapy but their hearing loss was not affected by the medication. The pedigrees of two families with half sibs showed the familial incidence for consanguineous marriage. Consanguinity was found to be positive in five out of the seven patients. The tribal tradition in Saudi Arabia fosters consanguineous marriages for cultural and social reasons and pre-arranged marriages are still seen. PMID:7499943

  5. High anion gap refractory metabolic acidosis as a critical presentation of endosulfan poisoning

    Raj Kumar Sharma

    2011-01-01

    Full Text Available Organochloride insecticides are chlorinated cyclic hydrocarbons. One of such insecticides is endosulfan (6,7,8,9,10-10 hexachloro 1,5,5a,6,9,9a-hexahydro-6-methano-2,4,3-hexadithioxanthiep in 3-oxide and it has been widely used in agriculture since 1960. The uncontrolled use of these compounds in developing countries has resulted in the deaths of animals and humans. Characteristic clinical signs following acute exposure are indicative of CNS disturbances or overstimulation. Mortality and morbidity rates are high and there is no specific antidote. We present an uncommon presentation of endosulfan poisoning in a 32-year-old male with high anion gap severe refractory metabolic acidosis. The patient was treated with continuous renal replacement therapy and was salvaged. Till date, there is no case report from India for endosulfan poisoning with severe metabolic acidosis and hypotension. Through this case report, we emphasize the role of continuous renal replacement therapy as a rescue therapy for endosulfan poisoning with severe refractory metabolic acidosis and hypotension, even though it is a non dialyzable poison.

  6. Branched-chain amino acid metabolism in rat muscle: abnormal regulation in acidosis

    May, R.C.; Hara, Y.; Kelly, R.A.; Block, K.P.; Buse, M.G.; Mitch, W.E.

    1987-06-01

    Branched-chain amino acid (BCAA) metabolism is frequently abnormal in pathological conditions accompanied by chronic metabolic acidosis. To study how metabolic acidosis affects BCAA metabolism in muscle, rats were gavage fed a 14% protein diet with or without 4 mmol NH/sub 4/Cl x 100 g body wt/sup -1/ x day/sup -1/. Epitrochlearis muscles were incubated with L-(1-/sup 14/C)-valine and L-(1-/sup 14/C)leucine, and rates of decarboxylation, net transamination, and incorporation into muscle protein were measured. Plasma and muscle BCAA levels were lower in acidotic rats. Rates of valine and leucine decarboxylation and net transamination were higher in muscles from acidotic rats; these differences were associated with a 79% increase in the total activity of branched-chain ..cap alpha..-keto acid dehydrogenase and a 146% increase in the activated form of the enzyme. They conclude that acidosis affects the regulation of BCAA metabolism by enhancing flux through the transaminase and by directly stimulating oxidative catabolism through activation of branched-chain ..cap alpha..-keto acid dehydrogenase.

  7. Lentiform fork sign: a magnetic resonance finding in a case of acute metabolic acidosis.

    Grasso, Daniela; Borreggine, Carmela; Perfetto, Francesco; Bertozzi, Vincenzo; Trivisano, Marina; Specchio, Luigi Maria; Grilli, Gianpaolo; Macarini, Luca

    2014-06-01

    We report a 33 year-old woman addicted to chronic unspecified solvents abuse with stupor, respiratory disorders, tetraplegia and severe metabolic acidosis. On admission an unenhanced cranial CT scan showed symmetrical hypodensities of both lentiform nuclei. MR imaging performed 12 hours after stupor demonstrates bilateral putaminal hemorrhagic necrosis, bilateral external capsule, corona radiata and deep cerebellar hyperintensities with right cingulate cortex involvement. DWI reflected bilateral putaminal hyperintensities with restricted water diffusion as to citotoxic edema and development of vasogenic edema in the external capsule recalling a fork. On day twenty, after specific treatments MRI demonstrated a bilateral putaminal marginal enhancement. Bilateral putaminal necrosis is a characteristic but non-specific radiological finding of methanol poisoning. Lentiform Fork sign is a rare MRI finding reported in literature in 22 patients with various conditions characterized by metabolic acidosis. Vasogenic edema may be due to the differences in metabolic vulnerability between neurons and astrocytes. We postulate that metabolic acidosis could have an important role to generate this sign. PMID:24976195

  8. Lentiform Fork Sign: a Magnetic Resonance Finding in a Case of Acute Metabolic Acidosis

    Grasso, Daniela; Borreggine, Carmela; Perfetto, Francesco; Bertozzi, Vincenzo; Trivisano, Marina; Specchio, Luigi Maria; Grilli, Gianpaolo; Macarini, Luca

    2014-01-01

    Summary We report a 33 year-old woman addicted to chronic unspecified solvents abuse with stupor, respiratory disorders, tetraplegia and severe metabolic acidosis. On admission an unenhanced cranial CT scan showed symmetrical hypodensities of both lentiform nuclei. MR imaging performed 12 hours after stupor demonstrates bilateral putaminal hemorrhagic necrosis, bilateral external capsule, corona radiata and deep cerebellar hyperintensities with right cingulate cortex involvement. DWI reflected bilateral putaminal hyperintensities with restricted water diffusion as to citotoxic edema and development of vasogenic edema in the external capsule recalling a fork. On day twenty, after specific treatments MRI demonstrated a bilateral putaminal marginal enhancement. Bilateral putaminal necrosis is a characteristic but non-specific radiological finding of methanol poisoning. Lentiform Fork sign is a rare MRI finding reported in literature in 22 patients with various conditions characterized by metabolic acidosis. Vasogenic edema may be due to the differences in metabolic vulnerability between neurons and astrocytes. We postulate that metabolic acidosis could have an important role to generate this sign. PMID:24976195

  9. Acidosis Decreases c-Myc Oncogene Expression in Human Lymphoma Cells: A Role for the Proton-Sensing G Protein-Coupled Receptor TDAG8

    Zhigang Li; Lixue Dong; Eric Dean; Yang, Li V.

    2013-01-01

    Acidosis is a biochemical hallmark of the tumor microenvironment. Here, we report that acute acidosis decreases c-Myc oncogene expression in U937 human lymphoma cells. The level of c-Myc transcripts, but not mRNA or protein stability, contributes to c-Myc protein reduction under acidosis. The pH-sensing receptor TDAG8 (GPR65) is involved in acidosis-induced c-Myc downregulation. TDAG8 is expressed in U937 lymphoma cells, and the overexpression or knockdown of TDAG8 further decreases or partia...

  10. Approach to the evaluation of a patient with an increased serum osmolal gap and high-anion-gap metabolic acidosis.

    Kraut, Jeffrey A; Xing, Shelly Xiaolei

    2011-09-01

    An increase in serum osmolality and serum osmolal gap with or without high-anion-gap metabolic acidosis is an important clue to exposure to one of the toxic alcohols, which include methanol, ethylene glycol, diethylene glycol, propylene glycol, or isopropanol. However, the increase in serum osmolal gap and metabolic acidosis can occur either together or alone depending on several factors, including baseline serum osmolal gap, molecular weight of the alcohol, and stage of metabolism of the alcohol. In addition, other disorders, including diabetic or alcoholic ketoacidosis, acute kidney injury, chronic kidney disease, and lactic acidosis, can cause high-anion-gap metabolic acidosis associated with an increased serum osmolal gap and therefore should be explored in the differential diagnosis. It is essential for clinicians to understand the value and limitations of osmolal gap to assist in reaching the correct diagnosis and initiating appropriate treatment. In this teaching case, we present a systematic approach to diagnosing high serum osmolality and increased serum osmolal gap with or without high-anion-gap metabolic acidosis. PMID:21794966

  11. Distal renal tubular acidosis as a cause of osteomalacia in a patient with primary Sjögren's syndrome

    Jovelić Aleksandra

    2005-01-01

    Full Text Available Background. One half of the patients with primary Sjögren’s syndrome has extraglandular manifestations, including renal involvement. The most frequent renal lesion is tubulo-interstitial nephritis, which manifests clinically as distal tubular acidosis and may result in the development of osteomalacia. Case report. In a 29 - year-old female patient, with bilateral nephrolithiasis, the diagnosis of primary Sjögren’s syndrome, tubulo-interstitial nephritis, distal renal tubular acidosis, and hypokalemia were established. She was treated for hypokalemia. Two years later she developed bone pains and muscle weakness, she wasn’t able to walk, her proximal muscles and pelvic bones were painful, with radiological signs of pelvic bones osteopenia and pubic bones fractures. The diagnosis of osteomalacia was established and the treatment started with Schol’s solution, vitamin D and calcium. In the following two months, acidosis was corrected, and the patient started walking. Conclusion. In our patient with primary Sjögren’s syndrome and interstitial nephritis, osteomalacia was a result of the long time decompensate acidosis, so the correction of acidosis, and the supplementation of vitamin D and calcium were the integral part of the therapy.

  12. Effect of metabolic acidosis on renal tubular sodium handling in rats as determined by lithium clearance

    Menegon L.F.

    1998-01-01

    Full Text Available Systemic metabolic acidosis is known to cause a decrease in salt and water reabsorption by the kidney. We have used renal lithium clearance to investigate the effect of chronic, NH4Cl-induced metabolic acidosis on the renal handling of Na+ in male Wistar-Hannover rats (200-250 g. Chronic acidosis (pH 7.16 ± 0.13 caused a sustained increase in renal fractional Na+ excretion (267.9 ± 36.4%, accompanied by an increase in fractional proximal (113.3 ± 3.6% and post-proximal (179.7 ± 20.2% Na+ and urinary K+ (163.4 ± 5.6% excretion when compared to control and pair-fed rats. These differences occurred in spite of an unchanged creatinine clearance and Na+ filtered load. A lower final body weight was observed in the acidotic (232 ± 4.6 g and pair-fed (225 ± 3.6 g rats compared to the controls (258 ± 3.7 g. In contrast, there was a significant increase in the kidney weights of acidotic rats (1.73 ± 0.05 g compared to the other experimental groups (control, 1.46 ± 0.05 g; pair-fed, 1.4 ± 0.05 g. We suggest that altered renal Na+ and K+ handling in acidotic rats may result from a reciprocal relationship between the level of metabolism in renal tubules and ion transport.

  13. Effect of chronic metabolic acidosis on bone density and bone architecture in vivo in rats.

    Gasser, Jürg A; Hulter, Henry N; Imboden, Peter; Krapf, Reto

    2014-03-01

    Chronic metabolic acidosis (CMA) might result in a decrease in vivo in bone mass based on its reported in vitro inhibition of bone mineralization, bone formation, or stimulation of bone resorption, but such data, in the absence of other disorders, have not been reported. CMA also results in negative nitrogen balance, which might decrease skeletal muscle mass. This study analyzed the net in vivo effects of CMA's cellular and physicochemical processes on bone turnover, trabecular and cortical bone density, and bone microarchitecture using both peripheral quantitative computed tomography and μCT. CMA induced by NH4Cl administration (15 mEq/kg body wt/day) in intact and ovariectomized (OVX) rats resulted in stable CMA (mean Δ[HCO3(-)]p = 10 mmol/l). CMA decreased plasma osteocalcin and increased TRAP5b in intact and OVX animals. CMA decreased total volumetric bone mineral density (vBMD) after 6 and 10 wk (week 10: intact normal +2.1 ± 0.9% vs. intact acidosis -3.6 ± 1.2%, P effect attributable to a decrease in cortical thickness and, thus, cortical bone mass (no significant effect on cancellous vBMD, week 10) attributed to an increase in endosteal bone resorption (nominally increased endosteal circumference). Trabecular bone volume (BV/TV) decreased significantly in both CMA groups at 6 and 10 wk, associated with a decrease in trabecular number. CMA significantly decreased muscle cross-sectional area in the proximal hindlimb at 6 and 10 wk. In conclusion, chronic metabolic acidosis induces a large decrease in cortical bone mass (a prime determinant of bone fragility) in intact and OVX rats and impairs bone microarchitecture characterized by a decrease in trabecular number. PMID:24352505

  14. Sjögren’s, Renal Tubular Acidosis And Osteomalacia - An Asian Indian Series

    Sandhya, Pulukool; Danda, Debashish; Rajaratnam, Simon; Thomas, Nihal

    2014-01-01

    Objective: To study the profile of Renal Tubular Acidosis (RTA) in Asian Indian patients with Primary Sjögren's Syndrome (pSS). Methods: The Electronic medical records of patients with a diagnosis of pSS seen between 2003 and 2010 at our tertiary care teaching hospital were screened for RTA. Clinical features, immunological profile, acid-base balance and electrolyte status, 25-hydroxyvitamin D (25(OH) D3) levels, histopathological changes in minor salivary gland biopsy samples and radiological findings were retrieved. RTA was diagnosed in cases of hyperchloremic metabolic acidosis with urinary pH values higher than 5.5. Those with known features suggestive of RTA including hypokalemic paralysis, hyperchloremia and nephrocalcinosis without acidosis were defined as incomplete RTA. Results: Of the 380 patients with clinically suspected pSS, 25 had RTA. The median age was 32 (18-60) years. Nineteen patients had complete RTA. Six had incomplete RTA. Only 10 patients (40%) had symptoms related to RTA at presentation. Sixteen patients (64%) had present or past history of hypokalemic paralysis. Pseudofractures were seen in 7 patients and an additional 2 had subclinical radiological osteomalacia. Majority of the patients (61.2%) had a normal 25(OH) D3 level. Those with osteomalacia had significantly lower serum phosphate, blood ph and higher alkaline phosphatase. Serum calcium and 25(OH) D3 levels were not significantly different between patients with osteomalacia and those without. Conclusion: Most patients were asymptomatic for RTA inspite of clinically overt and elicitable features. Skeletal manifestation was a common finding in patients with Sjögren and RTA, despite normal levels of 25 (OH) D3 in a majority. PMID:25584094

  15. SYSTEMIC LUPUS ERYTHEMATOSUS PRESENTING AS HYPOKALEMIC PERIODIC PARALYSIS SECONDARY TO DISTAL RENAL TUBULAR ACIDOSIS

    Ranjeet; Gurinder

    2014-01-01

    Systemic lupus erythematosus, referred to as SLE or lupus, is sometimes called the “great imitator.” Why? Because of its wide range of symptoms, people often confuse lupus with other health problems. We report the case of a 22-year-old woman who presented with a flaccid paralysis of limbs due to severe hypokalemia as a consequence of distal renal tubular acidosis (dRTA). A search for the cause of dRTA revealed latent Systemic Lupus Erythematosus (SLE). SLE presenting as dRTA ...

  16. SYSTEMIC LUPUS ERYTHEMATOSUS PRESENTING AS HYPOKALEMIC PERIODIC PARALYSIS SECONDARY TO DISTAL RENAL TUBULAR ACIDOSIS

    Ranjeet

    2014-05-01

    Full Text Available Systemic lupus erythematosus, referred to as SLE or lupus, is sometimes called the “great imitator.” Why? Because of its wide range of symptoms, people often confuse lupus with other health problems. We report the case of a 22-year-old woman who presented with a flaccid paralysis of limbs due to severe hypokalemia as a consequence of distal renal tubular acidosis (dRTA. A search for the cause of dRTA revealed latent Systemic Lupus Erythematosus (SLE. SLE presenting as dRTA is uncommon

  17. Primary Sjö-gren's syndrome presenting with distal, renal tubular acidosis and rhabdomyolysis.

    Prakash, E B S; Fernando, M E; Sathiyasekaran, Malathi; Bhoopathy, R M; Jayanth, J J; Samuel, J

    2006-12-01

    Primary Sjögren's syndrome (PSS) is rare in India. Clinically manifest renal disease in PSS is uncommon and is usually an autoimmune tubulointerstitial nephritis presenting with distal renal tubular acidosis (dRTA) or a urinary concentrating defect. Hypokalemic paralysis due to dRTA in PSS is rare but well documented in medical literature. Rhabdomyolysis as a consequence of hypokalemia in PSS is exceptional. We report a case of PSS with dRTA and rhabdomyolysis causing prolonged respiratory failure and quadriparesis. PMID:17334013

  18. Serum acute phase proteins in cows with SARA (Subacute Ruminal Acidosis) suspect

    C. Cannizzo; Gianesella, M.; Giudice, E.; Messina, V; G. Piccione; M. Morgante

    2012-01-01

    The aim of this study was to evaluate the variations of Acute Phase Proteins (APPs) and other blood constituents during the onset of the sub-acute ruminal acidosis (SARA) pathological status. A total of 108 cows from 12 dairy herds were randomly selected and divided into three Groups of 36 animals each. All animals were subjected to a rumenocentesis. Group A was composed by subjects with a rumen pH>5.8, Group B was composed by subjects with a rumen pH ≤5.5≤5.8 and Group C was composed by subj...

  19. Metabolic acidosis in late pregnancy due to 5-oxoproline (pyroglutamic acid)—A case report

    K. Jeyanthan; Sahathevan Sathiyathasan; Hamid, R.

    2012-01-01

    Introduction: Accumulation of 5-oxoproline (pyroglutamic acid) is a rare cause of severe, high anion gap metabolic acidosis in adults. Case: A 21 year old lady presented at 39 weeks gestation in her first pregnancy with 2 weeks history of shortness of breath. She suffered from ear ache and had been taking Paracetamol on regular basis for a year. She was admitted to having regular alcohol intake until the pregnancy when she stopped. She was not in acute distress and all her observations were s...

  20. D-Lactic Acidosis: An Underrecognized Complication of Short Bowel Syndrome

    N. Gurukripa Kowlgi; Lovely Chhabra

    2015-01-01

    D-lactic acidosis or D-lactate encephalopathy is a rare condition that occurs primarily in individuals who have a history of short bowel syndrome. The unabsorbed carbohydrates act as a substrate for colonic bacteria to form D-lactic acid among other organic acids. The acidic pH generated as a result of D-lactate production further propagates production of D-lactic acid, hence giving rise to a vicious cycle. D-lactic acid accumulation in the blood can cause neurologic symptoms such as delirium...

  1. Linfoma marginal del bazo asociado a acidosis láctica tipo B: Caso clínico Type B lactic acidosis associated with marginal lymphoma of the spleen: Report of one case

    Jorge Vega; María de los Ángeles Rodríguez; Armando Peña; Alejadro Vásquez

    2012-01-01

    Lactic acidosis in the absence of hypoxia or tissue hypoperfusion (type B) is very rare and is associated with the use of some drugs or malignancy. We report a 79-year-old woman, with a marginal non-Hodgkin's lymphoma of the spleen that was subjected to a splenectomy one year ago. She presented with unexplained tachypnea associated with pancytopenia and elevation of IgM to 10 times over the higher normal limit. Laboratory tests showed the presence of metabolic acidosis and high lactic acid le...

  2. Draft Genome Sequence of Lactobacillus delbrueckii Strain #22 Isolated from a Patient with Short Bowel Syndrome and Previous d-Lactic Acidosis and Encephalopathy.

    Domann, Eugen; Fischer, Florence; Glowatzki, Fabian; Fritzenwanker, Moritz; Hain, Torsten; Zechel-Gran, Silke; Giffhorn-Katz, Susanne; Neubauer, Bernd A

    2016-01-01

    d-Lactic acidosis with associated encephalopathy caused by overgrowth of intestinal lactic acid bacteria is a rarely diagnosed neurological complication of patients with short bowel syndrome. Here, we report the draft genome sequence of Lactobacillus delbrueckii strain #22 isolated from a patient with short bowel syndrome and previous d-lactic acidosis/encephalopathy. PMID:27469967

  3. Recurrent Anion Gap Acidosis: An Unusual Presentation of X-Linked Adrenoleukodystrophy in a Five-year-old Male

    Schwab, Joel; Pena, Loren; Sigman, Laura; Waggoner, Darrel

    2010-01-01

    We are presenting a five-year-old male with recurrent anion gap acidosis. During his last admission, it was detected that he had elevated VLCFA and the evaluation discovered that he had X-linked Adrenooleukodystrophy. He had the Addisonian only phenotype without any clinical or radiographic CNS findings. We were unable to find any other reports of this presentation of ALD. If the work-up of recurrent anion gap acidosis does not uncover an etiology, X-linked ALD should be considered in the dif...

  4. [Higher Brain Dysfunction in Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis and Stroke-Like Episodes (MELAS)].

    Ichikawa, Hiroo

    2016-02-01

    Stroke-like episodes are one of the cardinal features of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), and occur in 84-99% of the patients. The affected areas detected on neuroimaging do not have classical vascular distribution, and involve predominantly the temporal, parietal and occipital lobes. Thus, the neurological symptoms including higher brain dysfunction correlate with this topographical distribution. In association with the occipital lobe involvement, the most frequent symptom is cortical blindness. Other symptoms have been occasionally reported in case reports: visual agnosia, prosopagnosia, cortical deafness, auditory agnosia, topographical disorientation, various types of aphasia, hemispatial neglect, and so on. On the other hand, cognitive decline associated with more diffuse brain impairment rather than with focal stroke-like lesions has been postulated. This condition is also known as mitochondrial dementia. Domains of cognitive dysfunction include abstract reasoning, verbal memory, visual memory, language (naming and fluency), executive or constructive functions, attention, and visuospatial function. Cognitive functions and intellectual abilities may decline from initially minimal cognitive impairment to dementia. To date, the neuropsychological and neurologic impairment has been reported to be associated with cerebral lactic acidosis as estimated by ventricular spectroscopic lactate levels. PMID:26873235

  5. Magnetic resonance imaging detects placental hypoxia and acidosis in mouse models of perturbed pregnancies.

    Gabriele Bobek

    Full Text Available Endothelial dysfunction as a result of dysregulation of anti-angiogenic molecules secreted by the placenta leads to the maternal hypertensive response characteristic of the pregnancy complication of preeclampsia. Structural abnormalities in the placenta have been proposed to result in altered placental perfusion, placental oxidative stress, cellular damage and inflammation and the release of anti-angiogenic compounds into the maternal circulation. The exact link between these factors is unclear. Here we show, using Magnetic Resonance Imaging as a tool to examine placental changes in mouse models of perturbed pregnancies, that T 2 contrast between distinct regions of the placenta is abolished at complete loss of blood flow. Alterations in T 2 (spin-spin or transverse relaxation times are explained as a consequence of hypoxia and acidosis within the tissue. Similar changes are observed in perturbed pregnancies, indicating that acidosis as well as hypoxia may be a feature of pregnancy complications such as preeclampsia and may play a prominent role in the signalling pathways that lead to the increased secretion of anti-angiogenic compounds.

  6. Lipoyltransferase 1 Gene Defect Resulting in Fatal Lactic Acidosis in Two Siblings

    Taché, Véronique; Bivina, Liga; White, Sophie; Gregg, Jeffrey; Deignan, Joshua; Boyadjievd, Simeon A.; Poulain, Francis R.

    2016-01-01

    A term male neonate developed severe intractable lactic acidosis on day of life 1 and died the same day at our institution. The family previously lost another term, female newborn on day of life 1 from suspected sepsis at an outside hospital. After performing an autopsy on the neonate who died at our institution, extensive and lengthy neonatal and parental genetic testing, as well as biochemical analyses, and whole exome sequencing analysis identified compound heterozygous mutations in the lipoyltransferase 1 (LIPT1) gene responsible for the lipoylation of the 2-keto dehydrogenase complexes in the proband. These mutations were also identified in the deceased sibling. The clinical manifestations of these two siblings are consistent with those recently described in two unrelated families with lactic acidosis due to LIPT1 mutations, an underrecognized and underreported cause of neonatal death. Conclusions. Our observations contribute to the delineation of a new autosomal recessive metabolic disorder, leading to neonatal death. Our case report also highlights the importance of an interdisciplinary team in solving challenging cases. PMID:27247813

  7. Lipoyltransferase 1 Gene Defect Resulting in Fatal Lactic Acidosis in Two Siblings.

    Taché, Véronique; Bivina, Liga; White, Sophie; Gregg, Jeffrey; Deignan, Joshua; Boyadjievd, Simeon A; Poulain, Francis R

    2016-01-01

    A term male neonate developed severe intractable lactic acidosis on day of life 1 and died the same day at our institution. The family previously lost another term, female newborn on day of life 1 from suspected sepsis at an outside hospital. After performing an autopsy on the neonate who died at our institution, extensive and lengthy neonatal and parental genetic testing, as well as biochemical analyses, and whole exome sequencing analysis identified compound heterozygous mutations in the lipoyltransferase 1 (LIPT1) gene responsible for the lipoylation of the 2-keto dehydrogenase complexes in the proband. These mutations were also identified in the deceased sibling. The clinical manifestations of these two siblings are consistent with those recently described in two unrelated families with lactic acidosis due to LIPT1 mutations, an underrecognized and underreported cause of neonatal death. Conclusions. Our observations contribute to the delineation of a new autosomal recessive metabolic disorder, leading to neonatal death. Our case report also highlights the importance of an interdisciplinary team in solving challenging cases. PMID:27247813

  8. Lipoyltransferase 1 Gene Defect Resulting in Fatal Lactic Acidosis in Two Siblings

    Véronique Taché

    2016-01-01

    Full Text Available A term male neonate developed severe intractable lactic acidosis on day of life 1 and died the same day at our institution. The family previously lost another term, female newborn on day of life 1 from suspected sepsis at an outside hospital. After performing an autopsy on the neonate who died at our institution, extensive and lengthy neonatal and parental genetic testing, as well as biochemical analyses, and whole exome sequencing analysis identified compound heterozygous mutations in the lipoyltransferase 1 (LIPT1 gene responsible for the lipoylation of the 2-keto dehydrogenase complexes in the proband. These mutations were also identified in the deceased sibling. The clinical manifestations of these two siblings are consistent with those recently described in two unrelated families with lactic acidosis due to LIPT1 mutations, an underrecognized and underreported cause of neonatal death. Conclusions. Our observations contribute to the delineation of a new autosomal recessive metabolic disorder, leading to neonatal death. Our case report also highlights the importance of an interdisciplinary team in solving challenging cases.

  9. Mechanism of potassium depletion during chronic metabolic acidosis in the rat

    Pair-fed rats on a normal K diet were given either 1.5% NH4Cl or water for 4 days. The acid-fed animals developed metabolic acidosis, negative K balance, and K depletion. Urinary Na excretion and urinary flow were not different between the groups beyond the first day. After the 4 days, isolated kidneys from animals in each of these groups were perfused at normal pH and bicarbonate concentrations. Urinary K excretion was similar between the groups despite the potassium depletion in the acid-fed animals. In contrast, isolated kidneys from animals with comparable K depletion induced by dietary K restriction readily conserved K. Sodium excretion and urinary flow were similar among the three groups of isolated kidneys. Plasma aldosterone concentrations were greater in the acid-fed rats after the 4 days of NH4Cl ingestion than in the control animals. Adrenalectomized rats were treated with either normal (4 μg/day) or high (22 μg/day) aldosterone replacement while ingesting NH4Cl for 4 days. Only in the presence of high aldosterone replacement did the acid-fed adrenalectomized animals develop K depletion. The authors conclude that chronic metabolic acidosis stimulates aldosterone secretion, and that aldosterone maintains the inappropriately high urinary potassium excretion and K depletion seen in this acid-base disorder

  10. Metabolic acidosis mimicking diabetic ketoacidosis after use of calorie-free mineral water.

    Dahl, Gry T; Woldseth, Berit; Lindemann, Rolf

    2012-09-01

    A previously healthy boy was admitted with fever, tachycardia, dyspnea, and was vomiting. A blood test showed a severe metabolic acidosis with pH 7.08 and an anion gap of 36 mmol/L. His urine had an odor of acetone. The serum glucose was 5.6 mmol/L, and no glucosuria was found. Diabetic ketoacidosis could therefore be eliminated. Lactate level was normal. Tests for the most common metabolic diseases were negative. Because of herpes stomatitis, the boy had lost appetite and only been drinking Diet Coke and water the last days. Diet Coke or Coca-Cola Light is sweetened with a blend containing cyclamates, aspartame, and acesulfame potassium, all free of calories. The etiology of the metabolic acidosis appeared to be a catabolic situation exaggerated by fasting with no intake of calories. The elevated anion gap was due to a severe starvation ketoacidosis, mimicking a diabetic ketoacidosis. Pediatricians should recommend carbohydrate/calorie-containing fluids for rehydration of children with acute fever, diarrhea, or illness. PMID:22457081

  11. D-Lactic Acidosis: An Underrecognized Complication of Short Bowel Syndrome

    N. Gurukripa Kowlgi

    2015-01-01

    Full Text Available D-lactic acidosis or D-lactate encephalopathy is a rare condition that occurs primarily in individuals who have a history of short bowel syndrome. The unabsorbed carbohydrates act as a substrate for colonic bacteria to form D-lactic acid among other organic acids. The acidic pH generated as a result of D-lactate production further propagates production of D-lactic acid, hence giving rise to a vicious cycle. D-lactic acid accumulation in the blood can cause neurologic symptoms such as delirium, ataxia, and slurred speech. Diagnosis is made by a combination of clinical and laboratory data including special assays for D-lactate. Treatment includes correcting the acidosis and decreasing substrate for D-lactate such as carbohydrates in meals. In addition, antibiotics can be used to clear colonic flora. Although newer techniques for diagnosis and treatment are being developed, clinical diagnosis still holds paramount importance, as there can be many confounders in the diagnosis as will be discussed subsequently.

  12. Acidosis differentially modulates inactivation in NaV1.2, NaV1.4, and NaV1.5 channels

    PeterRuben

    2012-06-01

    Full Text Available NaV channels play a crucial role in neuronal and muscle excitability. Using whole-cell recordings we studied effects of low extracellular pH on the biophysical properties of NaV1.2, NaV1.4, and NaV1.5, expressed in cultured mammalian cells. Low pH produced different effects on different channel subtypes. Whereas NaV1.4 exhibited very low sensitivity to acidosis, primarily limited to partial block of macroscopic currents, the effects of low pH on gating in NaV1.2 and NaV1.5 were profound. In NaV1.2 low pH reduced apparent valence of steady-state fast inactivation, shifted the τ(V to depolarizing potentials and decreased channels availability during onset to slow and use-dependent inactivation. In contrast, low pH delayed open-state inactivation in NaV1.5, right-shifted the voltage-dependence of window current, and increased channel availability during onset to slow and use-dependent inactivation. These results suggest that protons affect channel availability in an isoform-specific manner. A computer model incorporating these results demonstrates their effects on membrane excitability.

  13. Tumor environmental factors glucose deprivation and lactic acidosis induce mitotic chromosomal instability--an implication in aneuploid human tumors.

    Chunyan Dai

    Full Text Available Mitotic chromosomal instability (CIN plays important roles in tumor progression, but what causes CIN is incompletely understood. In general, tumor CIN arises from abnormal mitosis, which is caused by either intrinsic or extrinsic factors. While intrinsic factors such as mitotic checkpoint genes have been intensively studied, the impact of tumor microenvironmental factors on tumor CIN is largely unknown. We investigate if glucose deprivation and lactic acidosis--two tumor microenvironmental factors--could induce cancer cell CIN. We show that glucose deprivation with lactic acidosis significantly increases CIN in 4T1, MCF-7 and HCT116 scored by micronuclei, or aneuploidy, or abnormal mitosis, potentially via damaging DNA, up-regulating mitotic checkpoint genes, and/or amplifying centrosome. Of note, the feature of CIN induced by glucose deprivation with lactic acidosis is similar to that of aneuploid human tumors. We conclude that tumor environmental factors glucose deprivation and lactic acidosis can induce tumor CIN and propose that they are potentially responsible for human tumor aneuploidy.

  14. An unusual case of refractory metabolic acidosis after homeopathic medicinal treatment

    Sameer Saraf

    2014-01-01

    Full Text Available Homeopathy is one of the most frequently used and controversial systems of complementary and alternative medicine (CAM. It is based on the ′principle of similars′, whereby highly diluted preparations of substances that cause symptoms in healthy individuals are used to stimulate healing in patients who have similar symptoms when ill 1. General trends show a rise in the number of individuals utilising naturopathic and homeopathic therapeutic methods 2. The patients who seek homeopathic treatment are primarily those suffering from long-standing, chronic disease 1. Certainly, the CAM can show clinical benefits. However, some of these also involve a considerable risk of sometimes severe side-effects. We here are reporting an unusual case of refractory metabolic acidosis after homeopathic medicinal treatment.

  15. Dermal bone in early tetrapods: a palaeophysiological hypothesis of adaptation for terrestrial acidosis.

    Janis, Christine M; Devlin, Kelly; Warren, Daniel E; Witzmann, Florian

    2012-08-01

    The dermal bone sculpture of early, basal tetrapods of the Permo-Carboniferous is unlike the bone surface of any living vertebrate, and its function has long been obscure. Drawing from physiological studies of extant tetrapods, where dermal bone or other calcified tissues aid in regulating acid-base balance relating to hypercapnia (excess blood carbon dioxide) and/or lactate acidosis, we propose a similar function for these sculptured dermal bones in early tetrapods. Unlike the condition in modern reptiles, which experience hypercapnia when submerged in water, these animals would have experienced hypercapnia on land, owing to likely inefficient means of eliminating carbon dioxide. The different patterns of dermal bone sculpture in these tetrapods largely correlates with levels of terrestriality: sculpture is reduced or lost in stem amniotes that likely had the more efficient lung ventilation mode of costal aspiration, and in small-sized stem amphibians that would have been able to use the skin for gas exchange. PMID:22535781

  16. Systemic lupus erythematosus with distal renal tubular acidosis presenting as hypokalemic paralysis with respiratory failure.

    Koul, Parvaiz Ahmad; Wahid, Abdul; Shah, Bashir Ahmad

    2003-01-01

    An eighteen-year-old woman presented with hypokalemic respiratory failure. She was found to have distal renal tubular acidosis (dRTA) as the underlying cause for hypokalemia. This was treated successfully, and no apparent etiology for the dRTA was discovered. Three years later she presented with full-blown picture of systemic lupus erythematosus (SLE) together with features of persistent dRTA complicated, this time, with bilateral renal calculi and nephrocalcinosis. It is very likely that the dRTA was an early feature that preceded the other markers of SLE. The moral of this case is that patients with dRTA should be followed-up carefully as a primary cause for the dRTA may show up in-due-course and to monitor the treatment so as to prevent long-term complications of the RTA. PMID:18209445

  17. Serum acute phase proteins in cows with SARA (Subacute Ruminal Acidosis suspect

    C. Cannizzo

    2012-02-01

    Full Text Available The aim of this study was to evaluate the variations of Acute Phase Proteins (APPs and other blood constituents during the onset of the sub-acute ruminal acidosis (SARA pathological status. A total of 108 cows from 12 dairy herds were randomly selected and divided into three Groups of 36 animals each. All animals were subjected to a rumenocentesis. Group A was composed by subjects with a rumen pH>5.8, Group B was composed by subjects with a rumen pH ≤5.5≤5.8 and Group C was composed by subjects with a rumen pH<5.5. Blood samples were collected by jugular venipuncture and Haptoglobin (Hp, Serum Amyloid A (SAA, Total Proteins, Albumin and White Blood Cells (WBC were determined. One-way ANOVA showed a statistical significance on Rumen pH, Hp, SAA. SARA seems not stimulate the APPs production from liver.

  18. Profound Intraoperative Metabolic Acidosis and Hypotension in a Child Undergoing Multilevel Spinal Fusion

    Mohanad Shukry

    2009-01-01

    Full Text Available The prone position may cause cardiovascular system depression. Yet, the mechanisms involved and preemptive measures are not well understood (Edgcombe et al. (2008. During spinal surgery in the prone position, hypotension may occur. Implicated factors include prolonged abdominal compression impeding venous return resulting in increased blood loss, decreased cardiovascular reserve, and the use of total intravenous anesthesia (TIVA which has been shown to blunt the sympathetic response more than inhalation anesthesia. We present a case of hypotension during spinal surgery with all its challenges. Hypotension and acidosis persisted despite all supporting measures, and only to improve with supine positioning. Differential diagnosis for such an event are discussed. Although abdominal compression may not be obvious before the start of surgery, compressing the spine during surgery may lead to abdominal compression and hypoperfusion to abdominal organs.

  19. Esubacute acidosis in rumen of high-yield dairy cows: Prevalence and prevention

    Petrujkić Branko T.

    2008-01-01

    Full Text Available The objective of the investigations presented in this paper was to establish the frequency of the incidence of subacute acidosis in the rumen of cows (SARA in the first three months of lactation and the possibilities for its prevention using a mineral mix based on bentonite, zeolite, magnesium oxide, and sodium bicarbonate (Mix plus. The values obtained for the rumen pH content show that subacute rumen acidosis occurs in in 20 percent of the examined cows in the early stage of lactation. For these investigations, cows in early stages of lactation were chosen and divided into 2 groups. Cows of the experimental group were administered a fodder mix which contained the mineral mix for a buffer effect (Mix plus. The average values of the rumen pH content in the control and the experimental group of cows at the beginning and on the 30th day of the experiment were approximately the same and did not differ significantly (p>0.05. On the 60th day of the experiment, the values for the electrochemical reaction of the rumen content for the control group amounted to an average of 6.219±0.18, and for the experimental group of cows it was 6.772±0.23. The obtained difference was statistically very significant (p<0.001. At the end of the experiment, on the 90th day, the average pH value of the rumen content of cows of the control group was 6.308±0.16, while this value in the experimental group of cows was significantly higher and amounted to 6.676±0.29 (p<0.01.

  20. Diagnostic Challenge in a Patient with Severe Anion Gap Metabolic Acidosis

    Eugene M. Tan

    2015-01-01

    Full Text Available The approach to the patient with acute renal failure and elevated anion and osmolal gap is difficult. Differential diagnoses include toxic alcohol ingestion, diabetic or starvation ketoacidosis, or 5-oxoproline acidosis. We present a 76-year-old female with type 2 diabetes mellitus, who was found at home in a confused state. Laboratory analysis revealed serum pH 6.84, bicarbonate 5.8 mmol/L, pCO2 29 mmHg, anion gap 22.2 mmol/L, osmolal gap 17.4 mOsm/kg, elevated beta-hydroxybutyrate (4.2 mmol/L, random blood sugar 213 mg/dL, creatinine 2.1 mg/dL, and potassium 7.5 mmol/L with no electrocardiogram (EKG changes. Fomepizole and hemodialysis were initiated for presumed ethylene glycol or methanol ingestion. Drug screens returned negative for ethylene glycol, alcohols, and acetaminophen, but there were elevated urine levels of acetone (11 mg/dL. The acetaminophen level was negative, and 5-oxoproline was not analyzed. After 5 days in the intensive care unit (ICU, her mental status improved with supportive care. She was discharged to a nursing facility. Though a diagnosis was not established, our patient’s presentation was likely due to starvation ketosis combined with chronic acetaminophen ingestion. Acetone ingestion is less likely. Overall, our case illustrates the importance of systematically approaching an elevated osmolal and anion gap metabolic acidosis.

  1. Evolution of endotoxin induced acute lung injury in the rat.

    Domenici-Lombardo, L.; C. Adembri; Consalvo, M.; Forzini, R.; Meucci, M.; Romagnoli, P; Novelli, G.P.

    1995-01-01

    To clarify the evolution of acute lung injury induced by endotoxin, the progression of lung damage in 26 rats submitted to intratracheal instillation of 5 mg/kg body weight endotoxin was examined by blood gas analysis, computerized tomography, light and electron microscopy. Hypoxaemia, hypercapnia, acidosis and inhomogeneous bilateral infiltrates developed gradually within 48 hours. Monocytes appeared within blood capillaries and the instertitium by 12 hours after treatment, then migrated int...

  2. An Analytical Delay Model

    MIN Yinghua; LI Zhongcheng

    1999-01-01

    Delay consideration has been a majorissue in design and test of high performance digital circuits. Theassumption of input signal change occurring only when all internal nodesare stable restricts the increase of clock frequency. It is no longertrue for wave pipelining circuits. However, previous logical delaymodels are based on the assumption. In addition, the stable time of arobust delay test generally depends on the longest sensitizable pathdelay. Thus, a new delay model is desirable. This paper explores thenecessity first. Then, Boolean process to analytically describe thelogical and timing behavior of a digital circuit is reviewed. Theconcept of sensitization is redefined precisely in this paper. Based onthe new concept of sensitization, an analytical delay model isintroduced. As a result, many untestable delay faults under thelogical delay model can be tested if the output waveforms can be sampledat more time points. The longest sensitizable path length is computedfor circuit design and delay test.

  3. Successful recovery from iatrogenic severe hypernatremia and severe metabolic acidosis resulting from accidental use of inappropriate bicarbonate concentrate for hemodialysis treatment

    Guruprasad P Bhosale

    2015-01-01

    Full Text Available Bicarbonate dialysis is the treatment modality of choice for correction of metabolic acidosis in chronic renal failure. However, improper selection of dialysate concentrate can result in life-threatening human errors. We report a case of iatrogenic severe hypernatremia (sodium 207 mEq/L and severe metabolic acidosis (pH 6.65 that resulted due to accidental use of inappropriate bicarbonate concentrate for hemodialysis treatment. There was successful recovery in this patient with no neurological sequelae. To the best of our knowledge, this is the first case report in adults of severe hypernatremia along with severe metabolic acidosis due to error in the preparation of dialysis fluid.

  4. Continuous retrieval of delayed Raman polaritons

    Smartsev, Slava; Davidson, Nir; Firstenberg, Ofer

    2016-01-01

    We use a Raman four-wave mixing process to read out light from an atomic coherence which is continuously written. This realizes a continuous source of polaritons having been delayed or effectively stored for a finite duration. Contrary to slow-light delay, which depends on the atom number and population distribution, here the effective storage duration is determined solely by intensive properties of the system, approaching the ground-state natural lifetime at the weak driving limit. The generated polaritons are background free. We experimentally probe these properties utilizing spatial atomic diffusion as an 'internal clock' for the write-read delay. A continuous source of delayed polaritons can replace discrete write-read procedures when the atomic evolution is the subject of interest, for example, when dipolar interactions lead to retrieval of non-classical light.

  5. Neuropsychomotor developmental delay: conceptual map, term definitions, uses and limitations

    Lílian de Fátima Dornelas; Neuza Maria de Castro Duarte; Lívia de Castro Magalhães

    2015-01-01

    OBJECTIVE: 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. DATA SOURCE: 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 deve...

  6. Linfoma marginal del bazo asociado a acidosis láctica tipo B: Caso clínico Type B lactic acidosis associated with marginal lymphoma of the spleen: Report of one case

    Jorge Vega

    2012-02-01

    Full Text Available Lactic acidosis in the absence of hypoxia or tissue hypoperfusion (type B is very rare and is associated with the use of some drugs or malignancy. We report a 79-year-old woman, with a marginal non-Hodgkin's lymphoma of the spleen that was subjected to a splenectomy one year ago. She presented with unexplained tachypnea associated with pancytopenia and elevation of IgM to 10 times over the higher normal limit. Laboratory tests showed the presence of metabolic acidosis and high lactic acid levels in the absence of infection, tissue hypoxia or hypoperfusion. She was treated with sodium bicarbonate and steroids without obtaining a reduction in lactate levels. Twelve days after admission, a single dose of Rituximab quickly normalized lactate concentrations and platelet count. After the fourth dose of Rituximab, pancytopenia disappeared and IgM fell to 25% of its baseline concentration.

  7. Delayed Gambler's Ruin

    Imai, Tomohisa

    2016-01-01

    We present here a new extended model of the gambler's ruin problem by incorporating delays in receiving of rewards and paying of penalties. When there is a difference between two delays, an exact analysis of the ruin probability is difficult. We derive an approximate scheme to find an effective shift in the initial assets of the gambler. Through comparison against computer simulations, this approximation is shown to work for small differences between the two delays.

  8. VARIABLE TIME DELAY MEANS

    Clemensen, R.E.

    1959-11-01

    An electrically variable time delay line is described which may be readily controlled simuitaneously with variable impedance matching means coupied thereto such that reflections are prevented. Broadly, the delay line includes a signal winding about a magnetic core whose permeability is electrically variable. Inasmuch as the inductance of the line varies directly with the permeability, the time delay and characteristic impedance of the line both vary as the square root of the permeability. Consequently, impedance matching means may be varied similariy and simultaneously w:th the electrically variable permeability to match the line impedance over the entire range of time delay whereby reflections are prevented.

  9. Non-Specific Inhibition of Ischemia- and Acidosis-Induced Intracellular Calcium Elevations and Membrane Currents by α-Phenyl-N-tert-butylnitrone, Butylated Hydroxytoluene and Trolox

    Christopher Katnik; Javier Cuevas

    2014-01-01

    Ischemia, and subsequent acidosis, induces neuronal death following brain injury. Oxidative stress is believed to be a key component of this neuronal degeneration. Acute chemical ischemia (azide in the absence of external glucose) and acidosis (external media buffered to pH 6.0) produce increases in intracellular calcium concentration ([Ca2+] i ) and inward membrane currents in cultured rat cortical neurons. Two α-tocopherol analogues, trolox and butylated hydroxytoluene (BHT), and the spin t...

  10. Successful recovery from iatrogenic severe hypernatremia and severe metabolic acidosis resulting from accidental use of inappropriate bicarbonate concentrate for hemodialysis treatment

    Bhosale, Guruprasad P; Veena R Shah

    2015-01-01

    Bicarbonate dialysis is the treatment modality of choice for correction of metabolic acidosis in chronic renal failure. However, improper selection of dialysate concentrate can result in life-threatening human errors. We report a case of iatrogenic severe hypernatremia (sodium 207 mEq/L) and severe metabolic acidosis (pH 6.65) that resulted due to accidental use of inappropriate bicarbonate concentrate for hemodialysis treatment. There was successful recovery in this patient with no neurologi...

  11. Pathophysiology of incomplete renal tubular acidosis in recurrent renal stone formers: evidence of disturbed calcium, bone and citrate metabolism

    Osther, P J; Bollerslev, Jens; Hansen, A B;

    1993-01-01

    Urinary acidification, bone metabolism and urinary excretion of calcium and citrate were evaluated in 10 recurrent stone formers with incomplete renal tubular acidosis (iRTA), 10 recurrent stone formers with normal urinary acidification (NUA) and 10 normal controls (NC). Patients with iRTA had......-carbonic acidosis during fasting may be a pathophysilogical factor of both nephrolithiasis and disturbed bone metabolism in stone formers with iRTA....... significantly increased in iRTA compared with NUA and NC (P <0.01), indicating increased bone turnover in stone formers with iRTA. Stone formers with iRTA thus presented with disturbed calcium, bone and citrate metabolism--the same metabolic abnormalities which characterize classic type 1 RTA. Mild non...

  12. Hypokalemic paralysis and osteomalacia secondary to renal tubular acidosis in a case with primary Sjögren's syndrome.

    Kawashima, Masanori; Amano, Tetsuki; Morita, Yoshitaka; Yamamura, Masahiro; Makino, Hirofumi

    2006-01-01

    A 39-year-old Japanese woman was admitted to our hospital for severe weakness owing to potassium deficiency caused by type 1 renal tubular acidosis (RTA1). Sicca complex, serological tests, and lip biopsy revealed that she had Sjögren's syndrome (SS). Acidosis was corrected by alkali supplement treatment. She also had an impaired renal function with proteinuria, and high absorbance on Ga scintigram was recognized in both kidneys. She was taking warfarin potassium after aortic valve substitution due to aortic regurgitation, therefore renal biopsy was not performed. Prednisone (20 mg/day) was administered for renal inflammation. One month later, she suffered severe chest wall pains with some local tender points over the costae of both sides, which was presumed to be due to pseudo-fractures based on osteomalacia. Hypokalemic paralysis and osteomalacia should be taken into consideration in the diagnosis of SS with RTA1. PMID:16622725

  13. Osteomalacia complicating renal tubular acidosis in association with Sjogren′s syndrome

    Zohra El Ati

    2014-01-01

    Full Text Available Renal involvement in Sjogren′s syndrome (SS is not uncommon and may precede other complaints. Tubulointerstitial nephritis is the most common renal disease in SS and may lead to renal tubular acidosis (RTA, which in turn may cause osteomalacia. Nevertheless, osteomalacia rarely occurs as the first manifestation of a renal tubule disorder due to SS. We herewith describe a 43-year-old woman who was admitted to our hospital for weakness, lumbago and inability to walk. X-ray of the long bones showed extensive demineralization of the bones. Laboratory investigations revealed chronic kidney disease with serum creatinine of 2.3 mg/dL and creatinine clearance of 40 mL/min, hypokalemia (3.2 mmol/L, hypophosphatemia (0.4 mmol/L, hypocalcemia (2.14 mmol/L and hyperchloremic metabolic acidosis (chlorine: 114 mmol/L; alkaline reserve: 14 mmol/L. The serum alkaline phosphatase levels were elevated. The serum levels of 25-hydroxyvitamin D and 1,25-dihydroxy vitamin D were low and borderline low, respectively, and the parathyroid hormone level was 70 pg/L. Urinalysis showed inappropriate alkaline urine (urinary PH: 7, glycosuria with normal blood glucose, phosphaturia and uricosuria. These values indicated the presence of both distal and proximal RTA. Our patient reported dryness of the mouth and eyes and Schirmer′s test showed xerophthalmia. An accessory salivary gland biopsy showed changes corresponding to stage IV of Chisholm and Masson score. Kidney biopsy showed diffuse and severe tubulo-interstitial nephritis with dense lymphoplasmocyte infiltrates. Sicca syndrome and renal interstitial infiltrates indicated SS as the underlying cause of the RTA and osteomalacia. The patient received alkalinization, vitamin D (Sterogyl ®, calcium supplements and steroids in an initial dose of 1 mg/kg/day, tapered to 10 mg daily. The prognosis was favorable and the serum creatinine level was 1.7 mg/dL, calcium was 2.2 mmol/L and serum phosphate was 0.9 mmol/L.

  14. Spiking Activity of a LIF Neuron in Distributed Delay Framework

    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.

  15. Oral rehydration therapy: efficacy of sodium citrate equals to sodium bicarbonate for correction of acidosis in diarrhoea.

    Islam, M. R.; Samadi, A R; Ahmed, S. M. [وسمية محمد أحمد; Bardhan, P K; Ali, A.

    1984-01-01

    Forty patients with moderate degrees of dehydration and acidosis because of acute watery diarrhoea were successfully treated randomly with either WHO recommended oral rehydration solution containing 2.5 g sodium bicarbonate or an oral solution containing 2.94 g sodium citrate in place of sodium bicarbonate per litre of oral rehydration rehydration solution. Efficacies were compared by measuring oral fluid intake, stool and vomitus output, change in body weight, hydration status, and rate of c...

  16. Sympathetic activation in exercise is not dependent on muscle acidosis. Direct evidence from studies in metabolic myopathies

    Vissing, J.; Vissing, S. F.; MacLean, D. A.; Saltin, B.; Quistorff, B.; Haller, R. G.; Blomqvist, C. G. (Principal Investigator)

    1998-01-01

    Muscle acidosis has been implicated as a major determinant of reflex sympathetic activation during exercise. To test this hypothesis we studied sympathetic exercise responses in metabolic myopathies in which muscle acidosis is impaired or augmented during exercise. As an index of reflex sympathetic activation to muscle, microneurographic measurements of muscle sympathetic nerve activity (MSNA) were obtained from the peroneal nerve. MSNA was measured during static handgrip exercise at 30% of maximal voluntary contraction force to exhaustion in patients in whom exercise-induced muscle acidosis is absent (seven myophosphorylase deficient patients; MD [McArdle's disease], and one patient with muscle phosphofructokinase deficiency [PFKD]), augmented (one patient with mitochondrial myopathy [MM]), or normal (five healthy controls). Muscle pH was monitored by 31P-magnetic resonance spectroscopy during handgrip exercise in the five control subjects, four MD patients, and the MM and PFKD patients. With handgrip to exhaustion, the increase in MSNA over baseline (bursts per minute [bpm] and total activity [%]) was not impaired in patients with MD (17+/-2 bpm, 124+/-42%) or PFKD (65 bpm, 307%), and was not enhanced in the MM patient (24 bpm, 131%) compared with controls (17+/-4 bpm, 115+/-17%). Post-handgrip ischemia studied in one McArdle patient, caused sustained elevation of MSNA above basal suggesting a chemoreflex activation of MSNA. Handgrip exercise elicited an enhanced drop in muscle pH of 0.51 U in the MM patient compared with the decrease in controls of 0.13+/-0.02 U. In contrast, muscle pH increased with exercise in MD by 0.12+/-0.05 U and in PFKD by 0.01 U. In conclusion, patients with glycogenolytic, glycolytic, and oxidative phosphorylation defects show normal muscle sympathetic nerve responses to static exercise. These findings indicate that muscle acidosis is not a prerequisite for sympathetic activation in exercise.

  17. Thiamine Deficiency in a Developed Country: Acute Lactic Acidosis in Two Neonates Due to Unsupplemented Parenteral Nutrition.

    Salvatori, Guglielmo; Mondì, Vito; Piersigilli, Fiammetta; Capolupo, Irma; Pannone, Veronica; Vici, Carlo Dionisi; Rizzo, Cristiano; Dotta, Andrea

    2016-08-01

    Thiamine is a water-soluble vitamin implicated in several metabolic processes. Its deficiency, due to prolonged parenteral nutrition without adequate vitamin supplementation, can lead to multiorgan failure characterized by cardiovascular impairment and metabolic acidosis refractory to bicarbonate administration. Only thiamine administration allows the remission of symptoms. We report 2 preterm infants with acute thiamine deficiency due to prolonged parenteral nutrition without adequate vitamin supplementation. PMID:25591974

  18. An Uncommon Presentation of HDR Syndrome: Distal Renal Tubular Acidosis in a Patient with Sjögren's Syndrome

    Ebru Sevinç OK

    2015-12-01

    Full Text Available HDR syndrome is an autosomal dominant disorder characterized by hypoparathyroidism, sensorineural deafness and renal dysplasia. Haploinsufficiency of GATA3 on chromosome 10p15 is implicated in the pathogenesis of the syndrome. It may manifest itself with clinical features other than the classical triad. Here we report a case of HDR syndrome with concomitant Sjögren’s syndrome in a 33-year-old who female presented with distal renal tubular acidosis (dRTA.

  19. Acidosis decreases c-Myc oncogene expression in human lymphoma cells: a role for the proton-sensing G protein-coupled receptor TDAG8.

    Li, Zhigang; Dong, Lixue; Dean, Eric; Yang, Li V

    2013-01-01

    Acidosis is a biochemical hallmark of the tumor microenvironment. Here, we report that acute acidosis decreases c-Myc oncogene expression in U937 human lymphoma cells. The level of c-Myc transcripts, but not mRNA or protein stability, contributes to c-Myc protein reduction under acidosis. The pH-sensing receptor TDAG8 (GPR65) is involved in acidosis-induced c-Myc downregulation. TDAG8 is expressed in U937 lymphoma cells, and the overexpression or knockdown of TDAG8 further decreases or partially rescues c-Myc expression, respectively. Acidic pH alone is insufficient to reduce c-Myc expression, as it does not decrease c-Myc in H1299 lung cancer cells expressing very low levels of pH-sensing G protein-coupled receptors (GPCRs). Instead, c-Myc is slightly increased by acidosis in H1299 cells, but this increase is completely inhibited by ectopic overexpression of TDAG8. Interestingly, TDAG8 expression is decreased by more than 50% in human lymphoma samples in comparison to non-tumorous lymph nodes and spleens, suggesting a potential tumor suppressor function of TDAG8 in lymphoma. Collectively, our results identify a novel mechanism of c-Myc regulation by acidosis in the tumor microenvironment and indicate that modulation of TDAG8 and related pH-sensing receptor pathways may be exploited as a new approach to inhibit Myc expression. PMID:24152439

  20. Acidosis Decreases c-Myc Oncogene Expression in Human Lymphoma Cells: A Role for the Proton-Sensing G Protein-Coupled Receptor TDAG8

    Zhigang Li

    2013-10-01

    Full Text Available Acidosis is a biochemical hallmark of the tumor microenvironment. Here, we report that acute acidosis decreases c-Myc oncogene expression in U937 human lymphoma cells. The level of c-Myc transcripts, but not mRNA or protein stability, contributes to c-Myc protein reduction under acidosis. The pH-sensing receptor TDAG8 (GPR65 is involved in acidosis-induced c-Myc downregulation. TDAG8 is expressed in U937 lymphoma cells, and the overexpression or knockdown of TDAG8 further decreases or partially rescues c-Myc expression, respectively. Acidic pH alone is insufficient to reduce c-Myc expression, as it does not decrease c-Myc in H1299 lung cancer cells expressing very low levels of pH-sensing G protein-coupled receptors (GPCRs. Instead, c-Myc is slightly increased by acidosis in H1299 cells, but this increase is completely inhibited by ectopic overexpression of TDAG8. Interestingly, TDAG8 expression is decreased by more than 50% in human lymphoma samples in comparison to non-tumorous lymph nodes and spleens, suggesting a potential tumor suppressor function of TDAG8 in lymphoma. Collectively, our results identify a novel mechanism of c-Myc regulation by acidosis in the tumor microenvironment and indicate that modulation of TDAG8 and related pH-sensing receptor pathways may be exploited as a new approach to inhibit Myc expression.

  1. Topiramate and severe metabolic acidosis: case report Acidose metabólica grave por topiramato: relato de caso

    Jayme E. Burmeister

    2005-06-01

    Full Text Available Topiramate infrequently induces anion gap metabolic acidosis through carbonic anhydrase inhibition on the distal tubule of the nephron - a type 2 renal tubular acidosis. We report on a 40 years old woman previously healthy that developed significant asymptomatic metabolic acidosis during topiramate therapy at a dosage of 100mg/day for three months. Stopping medication was followed by normalization of the acid-base status within five weeks. This infrequent side effect appears unpredictable and should be given careful attention.Topiramato pode produzir raramente uma acidose metabólica através da inibição da anidrase carbônica no túbulo distal do néfron - acidose tubular renal do tipo 2. Relatamos o caso de mulher de 40 anos previamente saudável que desenvolveu quadro de acidose metabólica assintomática grave, sem outra etiologia identificável, durante uso de topiramato na dose de 100mg/dia por três meses. Este efeito colateral, embora infrequente, parece ser imprevisível e requer atenção cuidadosa.

  2. Dynamic Network Delay Cartography

    Rajawat, Ketan; Giannakis, Georgios B

    2012-01-01

    Path delays in IP networks are important metrics, required by network operators for assessment, planning, and fault diagnosis. Monitoring delays of all source-destination pairs in a large network is however challenging and wasteful of resources. The present paper advocates a spatio-temporal Kalman filtering approach to construct network-wide delay maps using measurements on only a few paths. The proposed network cartography framework allows efficient tracking and prediction of delays by relying on both topological as well as historical data. Optimal paths for delay measurement are selected in an online fashion by leveraging the notion of submodularity. The resulting predictor is optimal in the class of linear predictors, and outperforms competing alternatives on real-world datasets.

  3. Tolerance of acute hypercapnic acidosis by the European eel ( Anguilla anguilla)

    McKenzie, D J; Taylor, E W; Dalla Valle, A Z;

    2002-01-01

    throughout, as a consequence of a significant increase in stroke volume at PwCO(2)s of 40, 60 and 80 mm Hg. The eels maintained O(2) uptake at routine normocapnic levels throughout hypercapnic exposure. A comparison of the rates of blood O(2) delivery (calculated from CO and caO(2)) against O(2) consumption...... at PwCO(2)s of 60 mm Hg and 80 mm Hg indicated that a portion of O(2) uptake was due to cutaneous respiration. Thus, the European eel's exceptional tolerance of acute hypercapnia is probably a consequence of the tolerance of its heart to acidosis and hypoxia, and a contribution to O(2) uptake from......European eels ( Anguilla anguilla) were exposed sequentially to partial pressures of CO(2) in the water ( PwCO(2)) of 5, 10, 20, 40, 60 then 80 mm Hg (equivalent to 0.66-10.5 kPa), for 30 min at each level. This caused a profound drop in arterial plasma pH, from 7.9 to below 7.2, an increase...

  4. Lactic acidosis and diastolic hypotension after intermittent albuterol nebulization in a pediatric patient

    Tehila A. Saadia

    2015-01-01

    Full Text Available We describe a case of 13-year-old female with intermittent asthma who developed lactic acidosis and diastolic hypotension after receiving intermittent albuterol nebulizer treatment. She presented to the emergency department (ED with sudden onset of shortness of breath and chest pain. She received two albuterol nebulizer treatments at home without symptomatic relief. She was treated in the ED with intermittent albuterol nebulization for a total of 22.5 mg over the next 5 hours. A decrease in diastolic blood pressure from 60 mmHg to 40 mmHg was noted after the treatment. Blood lactate level was 5.9 mmol/L. She recovered from it and was discharged to home but she had recurrence of shortness of breath and presented to the ED two days later. She was treated with albuterol nebulization for a total of 17.5 mg over the next two and half hours and developed diastolic hypotension again, as low as 30 mm Hg. After discontinuation of albuterol nebulization, her BP normalized. Cardiopulmonary and metabolic side effects of continuous albuterol therapy have been reported in the recent medical literature. Our patient, however, developed these adverse effects on intermittent albuterol nebulizer treatment. It is important for the pediatrician to recognize the adverse effects of β2-agonist therapy to avoid carrying out extensive workup for hypotension and hyperlactatemia prolonging hospital stay.

  5. Metabolic Acidosis and Strong Ion Gap in Critically Ill Patients with Acute Kidney Injury

    Cai-Mei Zheng

    2014-01-01

    Full Text Available Purpose. To determine the influence of physicochemical parameters on survival in metabolic acidosis (MA and acute kidney injury (AKI patients. Materials and Methods. Seventy-eight MA patients were collected and assigned to AKI or non-AKI group. We analyzed the physiochemical parameters on survival at 24 h, 72 h, 1 week, 1 month, and 3 months after AKI. Results. Mortality rate was higher in the AKI group. AKI group had higher anion gap (AG, strong ion gap (SIG, and apparent strong ion difference (SIDa values than non-AKI group. SIG value was higher in the AKI survivors than nonsurvivors and this value was correlated serum creatinine, phosphate, albumin, and chloride levels. SIG and serum albumin are negatively correlated with Acute Physiology and Chronic Health Evaluation IV scores. AG was associated with mortality at 1 and 3 months post-AKI, whereas SIG value was associated with mortality at 24 h, 72 h, 1 week, 1 month, and 3 months post-AKI. Conclusions. Whether high or low SIG values correlate with mortality in MA patients with AKI depends on its correlation with serum creatinine, chloride, albumin, and phosphate (P levels. AG predicts short-term mortality and SIG value predicts both short- and long-term mortality among MA patients with AKI.

  6. Dynamical behaviour of Liu system with time delayed feedback

    Qian Qin; Wang Lin; Ni Qiao

    2008-01-01

    This paper investigates the dynamical behaviour of the Liu system with time delayed feedback.Two typical situations are considered and the effect of time-delay parameter on the dynamics of the system is discussed.It is shown that the Liu system with time delayed feedback may exhibit interesting and extremely rich dynamical behaviour.The evolution of the dynamics is shown to be complex with varying time-delay parameter.Moreover,the strange attractor like 'wormhole' is detected via numerical simulations.

  7. Differential effects of acidosis, high potassium concentrations, and metabolic inhibition on noradrenaline release and its presynaptic muscarinic regulation.

    Haunstetter, Armin; Schulze Icking, Babette; Backs, Johannes; Krüger, Carsten; Haass, Markus

    2002-03-01

    It was the aim of the present study to characterize the effect of single components of ischaemia, such as inhibition of aerobic and anaerobic energy production by combined anoxic and glucose-free perfusion (metabolic inhibition), high extracellular potassium concentrations (hyperkalaemia), and acidosis, on (1). the stimulated release of noradrenaline from the in situ perfused guinea-pig heart and (2). its presynaptic modulation by the muscarinic agonist carbachol. The release of endogenous noradrenaline from efferent cardiac sympathetic nerve endings was induced by electrical stimulation of the left stellate ganglion (1 min, 5 V, 12 Hz) and quantified in the coronary venous effluent by high-performance liquid chromatography. Under control conditions, two consecutive electrical stimulations (S1, S2) elicited a similar noradrenaline overflow (S2/S1: 0.98 plus minus 0.05). After 10 min of global myocardial ischaemia overflow of endogenous noradrenaline was significantly reduced (S2/S1: 0.18 plus minus 0.03; P< 0.05). When studied separately, metabolic inhibition, hyperkalaemia (16 mM), and acidosis (pH 6.0) each markedly attenuated stimulated noradrenaline overflow (S2/S1: 0.65 plus minus 0.05, 0.43 plus minus 0.14, and 0.37 plus minus 0.09, respectively; P< 0.05). The muscarinic agonist carbachol (10 microM) inhibited stimulated noradrenaline release under normoxic conditions (S2/S1: 0.41 plus minus 0.07; P< 0.05). However, after 10 min of global myocardial ischaemia the inhibitory effect of carbachol on noradrenaline overflow was completely lost. Single components of ischaemia had a differential effect on presynaptic muscarinic modulation. Whereas hyperkalaemia (8-16 mM) did not affect muscarinic inhibition of noradrenaline release, carbachol lost its inhibitory effect during acidosis and metabolic inhibition. In conclusion, hyperkalaemia, metabolic inhibition, and severe acidosis each contribute to reduced overflow of noradrenaline after 10 min of myocardial

  8. Incidence of lactic acidosis toxicity among patients on stavudine or zidovudine containing antiretroviral therapy at Lighthouse clinics

    W Ng'ambi

    2012-11-01

    Full Text Available Although stavudine and zidovudine remain frequently used in low-income countries in Africa, they are associated with long-term toxicities. Lactic acidosis is one of the most serious toxicities in antiretroviral treatment (ART and occurs predominantly in regimens containing stavudine (D4T or zidovudine (AZT. We conducted this study to determine the incidence and risk factors for lactic acidosis among HIV-positive patients that have been on ART for at least 6 months. This study will bridge the gap that exists due to scarcity of data on the extent of toxicities due to long-term use of D4T and AZT. We conducted a retrospective cohort study using routine clinic data from the Lighthouse and Martin Preuss Centre electronic data systems. We used the clinic data collected between 1st January 2004 and 31st December 2011. We included into the analysis all patients that have been on D4T- or AZT-containing ARV drugs for at least 6 months. We analysed the data using Poisson regression of the number of cases of lactic acidosis (LA on gender, age at ART initiation, baseline BMI, and lipodystrophy in order to determine the incidence and risk factors for lactic acidosis. All statistical analyses were done at 5% significance level. We identified 14,854 patients that have ever been on D4T- or AZT-containing ARV drugs for longer than 5 months. Of these, 43% were male and median age was 34 years. The total number of cases of confirmed LA was 342 with observed mortality rate 40% more than the patients without confirmed LA. There were 23.02 cases of LA for every 1000 patient-years on D4T- or AZT-containing ART regimens. The strongest risk factor identified for developing LA was having a baseline BMI >25 with incidence rate ratio (IRR 3.11 (95% CI: 2.49, 3.88. The IRR for patients with a diagnosis of lipodystrophy was 1.77 (95% CI: 1.35, 2.32. Patients aged <30 years at ART initiation had 31% reduced risk of developing LA as compared to patients aged>39 years at ART

  9. Delay in Contests

    Bester, Helmut; Konrad, Kai A.

    2003-01-01

    "Why is there delay in contests? In this paper we follow and extend the line of reasoning of Carl von Clausewitz to explain delay. For a given contest technology, delay may occur if there is an asymmetry between defense and attack, if the expected change in relative strengths is moderate, and if the additional cost of investment in future strength is low." (author's abstract) "In Konfliktsituationen findet der 'showdown' häufig mit einer Verzögerung statt. Das ist überraschend, weil sich m...

  10. commensurate point delays

    M. de la Sen

    2005-01-01

    nominal controller is maintained. In the current approach, the finite spectrum assignment is only considered as a particular case of the designer's choice of a (delay-dependent arbitrary spectrum assignment objective.

  11. Vernier Delay Unit

    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

  12. Delayed Product Introduction

    Kai-Lung Hui; Qiu-Hong Wang

    2005-01-01

    We investigate the incentives of a monopolistic seller to delay the introduction of a new and improved version of his product. By analyzing a three-period model, we show that the seller may prefer to delay introducing a new product, even though the enabling technologies for the product are already available. The underlying motivation is analogous to that found in the durable goods monopolist literature – the seller suffers from a time inconsistency problem that causes his old and new products...

  13. Quad precision delay generator

    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

  14. Progress in Diagnosing Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like Episodes

    Ying-Xin Wang; Wei-Dong Le

    2015-01-01

    Objective:Mitochondrial myopathy,encephalopathy,lactic acidosis,and stroke-like episodes (MELAS) is a progressive,multisystem affected mitochondrial disease associated with a number of disease-related defective genes.MELAS has unpredictable presentations and clinical course,and it can be commonly misdiagnosed as encephalitis,cerebral infarction,or brain neoplasms.This review aimed to update the diagnosis progress in MELAS,which may provide better understanding of the disease nature and help make the right diagnosis as well.Data Sources:The data used in this review came from published peer review articles from October 1984 to October 2014,which were obtained from PubMed.The search term is "MELAS".Study Selection:Information selected from those reported studies is mainly based on the progress on clinical features,blood biochemistry,neuroimaging,muscle biopsy,and genetics in diagnosing MELAS.Results:MELAS has a wide heterogeneity in genetics and clinical manifestations.The relationship between mutations and phenotypes remains unclear.Advanced serial functional magnetic resonance imaging (MRI) can provide directional information on this disease.Muscle biopsy has meaningful value in diagnosing MELAS,which shows the presence of ragged red fibers and mosaic appearance of cytochrome oxidase negative fibers.Genetic studies have reported that approximately 80% of MELAS cases are caused by the mutation m.3243A>G of the mitochondrial transfer RNA (Leu (UUR)) gene (MT-TL1).Conclusions:MELAS involves multiple systems with variable clinical symptoms and recurrent episodes.The prognosis of MELAS patients depends on timely diagnosis.Therefore,overall diagnosis of MELAS should be based on the maternal inheritance family history,clinical manifestation,and findings from serial MRI,muscle biopsy,and genetics.

  15. Fatores de risco maternos associados à acidose fetal Maternal risk factors associated with fetal acidosis

    José Mauro Madi

    2010-09-01

    Full Text Available OBJETIVOS: avaliar os fatores de risco maternos associados à acidose fetal. MÉTODOS: estudo tipo caso-controle composto por 188 recém-nascidos, sendo que 47 compuseram o grupo casos (pH de artéria umbilical OBJECTIVES: to assess maternal risk factors associated with fetal acidosis. METHODS: a case-control type study was conducted of 188 neonates, of whom 47 comprised the case group (umbilical arterial pH <7.0 and 141 the control (umbilical arterial pH E7.1 <7.3. The study included only single-gestation neonates without congenital malformations. Both maternal and fetal variables were taken into consideration. Statistical analysis involved the calculation of the raw and adjusted Odds Ratio, Student's t-test, the chi-squared test and multivariate analysis using Enter-method non-conditional logistic regression. The level of statistical significance was set at p<0.05. RESULTS: in the case group higher percentages of caesarian sections and pre-term births were observed, involving almost five times as much intensive care and twenty-five times more likelihood of Apgar in the 5th minute <7. No association was observed between the groups and fetal presentation, mother's age, history of miscarriage, years of schooling of mother or attendance at prenatal sessions. After multivariate analysis, the only risk factors that remained significant were complications relating to the placenta or the umbilical cord. Deliveries involving complications relating to the placenta or the umbilical cord were three times more likely to involve fetal acidemia. CONCLUSIONS: acidemia among neonates was associated with a higher percentage of caesarians, premature births, a need for intensive care and treatment and an Apgar index of <7 in the 5th minute. After multivariate analysis, complications relating to premature displacement of the placenta and the umbilical cord were the only remaining risk factors associated with fetal acidemia.

  16. Non-Specific Inhibition of Ischemia- and Acidosis-Induced Intracellular Calcium Elevations and Membrane Currents by α-Phenyl-N-tert-butylnitrone, Butylated Hydroxytoluene and Trolox

    Christopher Katnik

    2014-02-01

    Full Text Available Ischemia, and subsequent acidosis, induces neuronal death following brain injury. Oxidative stress is believed to be a key component of this neuronal degeneration. Acute chemical ischemia (azide in the absence of external glucose and acidosis (external media buffered to pH 6.0 produce increases in intracellular calcium concentration ([Ca2+]i and inward membrane currents in cultured rat cortical neurons. Two α-tocopherol analogues, trolox and butylated hydroxytoluene (BHT, and the spin trapping molecule α-Phenyl-N-tert-butylnitrone (PBN were used to determine the role of free radicals in these responses. PBN and BHT inhibited the initial transient increases in [Ca2+]i, produced by ischemia, acidosis and acidic ischemia and increased steady state levels in response to acidosis and the acidic ischemia. BHT and PBN also potentiated the rate at which [Ca2+]i increased after the initial transients during acidic ischemia. Trolox inhibited peak and sustained increases in [Ca2+]i during ischemia. BHT inhibited ischemia induced initial inward currents and trolox inhibited initial inward currents activated by acidosis and acidic ischemia. Given the inconsistent results obtained using these antioxidants, it is unlikely their effects were due to elimination of free radicals. Instead, it appears these compounds have non-specific effects on the ion channels and exchangers responsible for these responses.

  17. Acidosis promotes Bcl-2 family-mediated evasion of apoptosis: involvement of acid-sensing G protein-coupled receptor Gpr65 signaling to Mek/Erk.

    Ryder, Christopher; McColl, Karen; Zhong, Fei; Distelhorst, Clark W

    2012-08-10

    Acidosis arises in solid and lymphoid malignancies secondary to altered nutrient supply and utilization. Tumor acidosis correlates with therapeutic resistance, although the mechanism behind this effect is not fully understood. Here we show that incubation of lymphoma cell lines in acidic conditions (pH 6.5) blocks apoptosis induced by multiple cytotoxic metabolic stresses, including deprivation of glucose or glutamine and treatment with dexamethasone. We sought to examine the role of the Bcl-2 family of apoptosis regulators in this process. Interestingly, we found that acidic culture causes elevation of both Bcl-2 and Bcl-xL, while also attenuating glutamine starvation-induced elevation of p53-up-regulated modulator of apoptosis (PUMA) and Bim. We confirmed with knockdown studies that these shifts direct survival decisions during starvation and acidosis. Importantly, the promotion of a high anti- to pro-apoptotic Bcl-2 family member ratio by acidosis renders cells exquisitely sensitive to the Bcl-2/Bcl-xL antagonist ABT-737, suggesting that acidosis causes Bcl-2 family dependence. This dependence appears to be mediated, in part, by the acid-sensing G protein-coupled receptor, GPR65, via a MEK/ERK pathway. PMID:22685289

  18. Data Assimilation by delay-coordinate nudging

    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.

  19. Effects of tight versus non tight control of metabolic acidosis on early renal function after kidney transplantation

    Etezadi Farhad

    2012-09-01

    Full Text Available Abstract Background Recently, several studies have been conducted to determine the optimal strategy for intra-operative fluid replacement therapy in renal transplantation surgery. Since infusion of sodium bicarbonate as a buffer seems to be safer than other buffer compounds (lactate, gluconate, acetatethat indirectly convert into it within the liver, We hypothesized tight control of metabolic acidosis by infusion of sodium bicarbonate may improve early post-operative renal function in renal transplant recipients. Methods 120 patients were randomly divided into two equal groups. In group A, bicarbonate was infused intra-operatively according to Base Excess (BE measurements to achieve the normal values of BE (−5 to +5 mEq/L. In group B, infusion of bicarbonate was allowed only in case of severe metabolic acidosis (BE ≤ −15 mEq/L or bicarbonate ≤ 10 mEq/L or PH ≤ 7.15. Minute ventilation was adjusted to keep PaCO2 within the normal range. Primary end-point was sampling of serum creatinine level in first, second, third and seventh post-operative days for statistical comparison between groups. Secondary objectives were comparison of cumulative urine volumes in the first 24 h of post-operative period and serum BUN levels which were obtained in first, second, third and seventh post-operative days. Results In group A, all of consecutive serum creatinine levels were significantly lower in comparison with group B. With regard to secondary outcomes, no significant difference between groups was observed. Conclusion Intra-operative tight control of metabolic acidosis by infusion of Sodium Bicarbonate in renal transplant recipients may improve early post-operative renal function.

  20. Effects of Time Delay on Three Interacting Species System with Noise

    Su, Yi-Jian; Mei, Dong-Cheng

    2008-09-01

    We study the effects of time delay in three interacting species system with noise. The time evolution and spatiotemporal pattern in the Lotka-Volterra model of three interacting species with noise and time delay were investigated by means of stochastic simulation. Our results indicate that: (i) Time delay induces the synchronously periodic oscillations of the three species densities; (ii) Time delay cause the spatiotemporal pattern to be concentrated.

  1. A Comparison of Treating Metabolic Acidosis in CKD Stage 4 Hypertensive Kidney Disease with Fruits and Vegetables or Sodium Bicarbonate

    Goraya, Nimrit; Simoni, Jan; Jo, Chan-Hee

    2013-01-01

    Summary Background and objectives Current guidelines recommend Na+-based alkali for CKD with metabolic acidosis and plasma total CO2 (PTCO2) < 22 mM. Because diets in industrialized societies are typically acid-producing, we compared base-producing fruits and vegetables with oral NaHCO3 (HCO3) regarding the primary outcome of follow-up estimated GFR (eGFR) and secondary outcomes of improved metabolic acidosis and reduced urine indices of kidney injury. Design, setting, participants, & measurements Individuals with stage 4 (eGFR, 15–29 ml/min per 1.73 m2) CKD due to hypertensive nephropathy, had a PTCO2 level < 22 mM, and were receiving angiotensin-converting enzyme inhibition were randomly assigned to 1 year of daily oral NaHCO3 at 1.0 mEq/kg per day (n=35) or fruits and vegetables dosed to reduce dietary acid by half (n=36). Results Plasma cystatin C–calculated eGFR did not differ at baseline and 1 year between groups. One-year PTCO2 was higher than baseline in the HCO3 group (21.2±1.3 versus 19.5±1.5 mM; P<0.01) and the fruits and vegetables group (19.9±1.7 versus 19.3±1.9 mM; P<0.01), consistent with improved metabolic acidosis, and was higher in the HCO3 than the fruits and vegetable group (P<0.001). One-year urine indices of kidney injury were lower than baseline in both groups. Plasma [K+] did not increase in either group. Conclusions One year of fruits and vegetables or NaHCO3 in individuals with stage 4 CKD yielded eGFR that was not different, was associated with higher-than-baseline PTCO2, and was associated with lower-than-baseline urine indices of kidney injury. The data indicate that fruits and vegetables improve metabolic acidosis and reduce kidney injury in stage 4 CKD without producing hyperkalemia. PMID:23393104

  2. Survival after cardiopulmonary arrest with extreme hyperkalaemia and hypothermia in a patient with metformin-associated lactic acidosis

    Tay, Stan; Lee, I-Lynn

    2012-01-01

    Potassium levels are regularly used as a prognostic factor to cease resuscitation in significant hypothermia. In this case report, we highlight how survival is still possible with extreme hyperkalaemia in severe hypothermia. We present a case of a 65-year-old Caucasian man who presented with metformin associated lactic acidosis. On presentation he had potassium of 9.1 mmol/l and a temperature of 31.5°C. Cardiopulmonary resuscitation was commenced when he went into asystolic arrest. This prese...

  3. An Unusual Initial Presentation of Sjögren’s Syndrome: Severe Hypokalemic Paralysis Secondary to Distal Renal Tubular Acidosis

    Sengul, Erkan; Bunul, Fatih; Yazici, Ayten; Sengul, Aysun; Dindar, Sevim; Halhalli, Gökçen Selma Kilic; Binnetoglu, Emine

    2013-01-01

    Sjögren’s syndrome is mainly affects the exocrine glands. Patients usually complain of persistent dryness of the mouth and eyes. However, nonexocrine organs such as the kidneys are often affected in these patients. Distal renal tubular acidosis (dRTA) and interstitiel nephritis are common in Sjögren’s syndrome. Nonetheless, severe hypokalemia and paralysis secondary to dRTA are unusual initial manifestation of Sjögren’s syndrome. Here, we describe a case of a 48 year old women admitted to the...

  4. Successfully Treated Calcific Uremic Arteriolopathy: Two Cases of a High Anion Gap Metabolic Acidosis with Intravenous Sodium Thiosulfate

    Joshua L. Rein

    2014-01-01

    Full Text Available Calcific uremic arteriolopathy (CUA is a rare and potentially fatal disorder of calcification involving subcutaneous small vessels and fat in patients with renal insufficiency. We describe the successful use of intravenous sodium thiosulfate (STS for the treatment of CUA in two patients. The first case was complicated by the development of a severe anion gap metabolic acidosis, which was accompanied by a seizure. Both patients had complete wound healing within five months. Although STS should be considered in the treatment of CUA, little is known about pharmacokinetics and additional studies are required to determine dosing strategies to minimize severe potential side effects.

  5. Effects of acidosis and NO on nicorandil-activated KATP channels in guinea-pig ventricular myocytes

    Moncada, Gustavo A; Kishi, Yukio; Numano, Fujio; Hiraoka, Masayasu; Sawanobori, Tohru

    2000-01-01

    Nicorandil is a hybrid compound of K+ channel opener and nitrate. We investigated a possible interaction of acidosis and nitric oxide (NO)-donors on the nicorandil-activated ATP-sensitive K+ channel (KATP) in guinea-pig ventricular myocytes using the patch-clamp technique.In whole-cell recordings, external application of 300 μM nicorandil activated KATP in the presence of 2 mM intracellular ATP concentration ([ATP]i) at external pH (pHo) 7.4, but the activated current was decreased by reducin...

  6. Time Delay Cosmography

    Treu, Tommaso

    2016-01-01

    Gravitational time delays, observed in strong lens systems where the variable background source is multiply-imaged by a massive galaxy in the foreground, provide direct measurements of cosmological distance that are very complementary to other cosmographic probes. The success of the technique depends on the availability and size of a suitable sample of lensed quasars or supernovae, precise measurements of the time delays, accurate modeling of the gravitational potential of the main deflector, and our ability to characterize the distribution of mass along the line of sight to the source. We review the progress made during the last 15 years, during which the first competitive cosmological inferences with time delays were made, and look ahead to the potential of significantly larger lens samples in the near future.

  7.  Distal Renal Tubular Acidosis, Hypokalemic Paralysis, Nephrocalcinosis, Primary Hypothyroidism, Growth Retardation, Osteomalacia and Osteoporosis Leading to Pathological Fracture: A Case Report

    Mayada Mohammad Swar

    2011-07-01

    Full Text Available  Renal tubular acidosis (RTA is a constellation of syndromes arising from different derangements of tubular acid transport. Recent advances in the biology of urinary acidification have allowed us to discern various molecular mechanisms responsible for these syndromes. RTA often presents as renal stone disease with nephrocalcinosis, ricket/osteomalacia and growth retardation in children with ultimate short stature in adulthood. The case reported here has features of distal renal tubular acidosis (dRTA, hypokalemic paralysis, primary hypothyroidism, growth retardation, osteomalacia and osteopenia leading to stress fracture. All these features presenting in a single case (as in our case is a rare occurrence, so far other cases of distal renal tubular acidosis (dRTA have been reported.

  8. Distal renal tubular acidosis, hypokalemic paralysis, nephrocalcinosis, primary hypothyroidism, growth retardation, osteomalacia and osteoporosis leading to pathological fracture: a case report.

    Basak, Ramen C; Sharkawi, Khairy Mostafa; Rahman, Mohammad Mizanur; Swar, Mayada Mohammad

    2011-07-01

    Renal tubular acidosis (RTA) is a constellation of syndromes arising from different derangements of tubular acid transport. Recent advances in the biology of urinary acidification have allowed us to discern various molecular mechanisms responsible for these syndromes. RTA often presents as renal stone disease with nephrocalcinosis, ricket/osteomalacia and growth retardation in children with ultimate short stature in adulthood. The case reported here has features of distal renal tubular acidosis (dRTA), hypokalemic paralysis, primary hypothyroidism, growth retardation, osteomalacia and osteopenia leading to stress fracture. All these features presenting in a single case (as in our case) is a rare occurrence, so far other cases of distal renal tubular acidosis (dRTA) have been reported. PMID:22043434

  9. Approximation of distributed delays

    Lu, Hao; Eberard, Damien; Simon, Jean-Pierre

    2010-01-01

    We address in this paper the approximation problem of distributed delays. Such elements are convolution operators with kernel having bounded support, and appear in the control of time-delay systems. From the rich literature on this topic, we propose a general methodology to achieve such an approximation. For this, we enclose the approximation problem in the graph topology, and work with the norm defined over the convolution Banach algebra. The class of rational approximates is described, and a constructive approximation is proposed. Analysis in time and frequency domains is provided. This methodology is illustrated on the stabilization control problem, for which simulations results show the effectiveness of the proposed methodology.

  10. Delayed breast implant reconstruction

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne;

    2011-01-01

    -stage procedures. From the Danish Registry for Plastic Surgery of the Breast, which has prospectively registered data for women undergoing breast implantations since 1999, we identified 559 women without a history of radiation therapy undergoing 592 delayed breast reconstructions following breast cancer during the......Studies of complications following reconstructive surgery with implants among women with breast cancer are needed. As the, to our knowledge, first prospective long-term study we evaluated the occurrence of complications following delayed breast reconstruction separately for one- and two...

  11. Asynchronous Bounded Expected Delay Networks

    Bakhshi, Rena; Endrullis, Jörg; Fokkink, Wan; Pang, Jun

    2010-01-01

    The commonly used asynchronous bounded delay (ABD) network models assume a fixed bound on message delay. We propose a probabilistic network model, called asynchronous bounded expected delay (ABE) model. Instead of a strict bound, the ABE model requires only a bound on the expected message delay. While the conditions of ABD networks restrict the set of possible executions, in ABE networks all asynchronous executions are possible, but executions with extremely long delays are less probable. In ...

  12. Delayed traumatic diaphragmatic hernia

    Lu, Jing; Wang, Bo; Che, Xiangming; Li, Xuqi; Qiu, Guanglin; He, Shicai; Fan, Lin

    2016-01-01

    Abstract Background: Traumatic diaphragmatic hernias (TDHs) are sometimes difficult to identify at an early stage and can consequently result in diagnostic delays with life-threatening outcomes. It is the aim of this case study to highlight the difficulties encountered with the earlier detection of traumatic diaphragmatic hernias. Methods: Clinical data of patients who received treatment for delayed traumatic diaphragmatic hernias in registers of the First Affiliated Hospital of Xi’an Jiaotong University from 1998 to 2014 were analyzed retrospectively. Results: Six patients were included in this study. Left hemidiaphragm was affected in all of them. Most of the patients had a history of traffic accident and 1 a stab-penetrating injury. The interval from injury to developing symptoms ranged from 2 to 11 years (median 5 years). The hernial contents included the stomach, omentum, small intestine, and colon. Diaphragmatic injury was missed in all of them during the initial managements. All patients received operations once the diagnosis of delayed TDH was confirmed, and no postoperative mortality was detected. Conclusions: Delayed TDHs are not common, but can lead to serious consequences once occurred. Early detection of diaphragmatic injuries is crucial. Surgeons should maintain a high suspicion for injuries of the diaphragm in cases with abdominal or lower chest traumas, especially in the initial surgical explorations. We emphasize the need for radiographical follow-up to detect diaphragmatic injuries at an earlier stage. PMID:27512848

  13. Speech and Language Delay

    ... child depends on the cause of the speech delay. Your doctor will tell you the cause of your child's problem and explain any treatments that might fix the problem or make it better. A speech and language pathologist might be helpful in making treatment plans. This ...

  14. Short Review of Our Work - “Chronic Metabolic Acidosis Destroys Pancreas” with Focus on the Functional Exocrine Pancreatic Disorders

    linic of San Fran

    2015-07-01

    Full Text Available We deeply appreciate your publishing of our work - “Chronic metabolic acidosis destroys pancreas” in JOP (2014 [1]. We feel that our work can give the food for thought to many young researchers and health practitioners. A short review of our work may generate various questions and ideas for further investigations. In our work, we have focused on negative affects of the chronic metabolic acidosis on pancreatic function including: • Premature activation of the proteases within the pancreas • Diminishing the antimicrobial activity of the pancreatic juice • Suppressing of the flushing out zymogens from the pancreas • Precipitation of the aggressive bile acids • Calcification Authors believe that further research may provide more details of how the acidification destroys the pancreas and causes chronic pancreatitis. We would like to share some of our thoughts on this subject as follows: Descriptions of symptoms of chronic pancreatitis such as pain, malabsorption syndrome, steatorrhea, and weight loss are found in almost all medical books, textbooks, and articles. The medical literature refers to these conditions as “pancreatic insufficiency”. It is known that these symptoms occur when only 10 % of the exocrine pancreatic function is left intact. This is not an “insufficiency.” It is a pancreatic “failure” when the therapeutic opportunities are very limited.

  15. Interferometric Propagation Delay

    Goldstein, Richard

    1999-01-01

    Radar interferometry based on (near) exact repeat passes has lately been used by many groups of scientists, worldwide, to achieve state of the art measurements of topography, glacier and ice stream motion, earthquake displacements, oil field subsidence, lava flows, crop-induced surface decorrelation, and other effects. Variations of tropospheric and ionospheric propagation delays limit the accuracy of all such measurements. We are investigating the extent of this limitation, using data from the Shuttle radar flight, SIR-C, which is sensitive to the troposphere, and the Earth Resources Satellites, ERS-1/2, which are sensitive to both the troposphere and the ionosphere. We are presently gathering statistics of the delay variations over selected, diverse areas to determine the best accuracy possible for repeat track interferometry. The phases of an interferogram depend on both the topography of the scene and variations in propagation delay. The delay variations can be caused by movement of elements in the scene, by changes in tropospheric water vapor and by changes of the charge concentrations in the ionosphere. We plan to separate these causes by using the data from a third satellite visit (three-pass interferometry). The figure gives the geometry of the three-pass observations. The page of the figure is taken to be perpendicular to the spacecraft orbits. The three observational locations are marked on the figure, giving baselines B-12 and B-13, separated by the angle alpha. These parameters are almost constant over the whole scene. However, each pixel has an individual look angle, theta, which is related to the topography, rho is the slant range. A possible spurious time delay is shown. Additional information is contained in the original.

  16. Data-assimilation by delay-coordinate nudging

    Pazó, D; López, J M

    2015-01-01

    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 ...

  17. Lactate production retards, not causes, acidosis: a theoretical approach for physical education students.

    R. Hohl

    2005-07-01

    increased blood  lactate detection  is the  effect  not  the  cause  of acidosis.   The  students  must  understand that if muscles do not  produce  lactate, acidoses and fatigue  would accour faster,  impairing  high intensity exercise performance.  This information must be considered  in their  training schedules.

  18. Subacute ruminal acidosis challenge changed in situ degradability of feedstuffs in dairy goats.

    Li, Fei; Cao, Yangchun; Liu, Nannan; Yang, Xinjian; Yao, Junhu; Yan, Dabing

    2014-01-01

    This study investigated the effects of wheat-induced subacute ruminal acidosis (SARA) on rumen bacterial populations and in situ degradabilities of NDF, starch, and crude protein of feeds. Four multiparous dairy goats (BW=60±3.3kg) fitted with ruminal cannulas were assigned to a 2×2 crossover design (28-d treatment periods separated by a 7-d washout interval). The treatment diets consisted of 2 levels of cracked wheat: 0 (control, corn based concentrate) and 35% (diet-induced SARA, wheat-based concentrate), with a constant forage- (45% alfalfa hay and 5% corn silage of DM) to-concentrate (50% of DM) ratio. Results indicate that diets with a 35% wheat decreased ruminal pH (6.21 vs. 5.98) and increased the duration (1.13 vs. 4.72h/d) and area (0.12 vs. 0.78 pH × h/d) of ruminal pH below 5.6 and induced SARA. The SARA increased ruminal total volatile fatty acid concentration, from 105.0 to 123.8mM, and decreased the acetate molar proportion (62.8 vs. 56.6mol/100mol) and the acetate-to-propionate ratio (3.5 vs. 2.8). Compared with the control group, SARA decreases the relative abundance of Fibrobacter succinogenes (-59.3%) and Ruminococcus flavefaciens (-68.4%), whereas it increased Succinimonas amylolytica (198.1%) and Ruminobacter amylophilus (125.2%). The SARA decreased 24- and 48-h dry matter (DM) and neutral detergent fiber (NDF) degradabilities of corn silage. The 48-h degradabilities of DM (51.0 vs. 48.2%) and NDF (40.3 vs. 36.0%) in alfalfa hay were not affected by SARA, but the SARA tended to reduce the 24-h DM (49.6 vs. 46.3%) and NDF (37.8 vs. 33.2%) degradabilities. The effective ruminal degradabilities of DM and NDF in alfalfa hay and corn silage were reduced during SARA. In situ degradability parameters of DM and starch of wheat were not affected by SARA, but starch degradability of corn (9.5 vs. 13.3%/h) increased. The SARA reduced in situ 12-h degradabilities of DM and crude protein of soybean meal and extruded soybean without affecting the

  19. Optimum Delayed Retirement Credit

    Sheshinski, Eytan

    2002-01-01

    A central question for pension design is how benefits should vary with the age of retirement beyond early eligibility age. It is often argued that in order to be neutral with respect to individual retirement decisions benefits should be actuarially fair, that is, the present value of additional contributions and benefits (’Delayed Retirement Credit’ - DRC) due to postponed retirement should be equal. We show that in a self-selection, asymmetric information model, because individual decisions ...

  20. Delay reduction: current status.

    Fantino, E; Preston, R. A.; Dunn, R

    1993-01-01

    Delay-reduction theory states that the effectiveness of a stimulus as a conditioned reinforcer may be predicted most accurately by the reduction in time to primary reinforcement correlated with its onset. We review support for the theory and then discuss two new types of experiments that assess it. One compares models of choice in situations wherein the less preferred outcome is made more accessible; the other investigates whether frequency of conditioned reinforcement affects choice beyond t...

  1. Time-Delay Interferometry

    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.

  2. Time-Delay Interferometry

    Dhurandhar, Sanjeev V.; Tinto, Massimo

    2005-07-01

    Equal-arm interferometric 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 and mathematical foundations of TDI as it will be implemented by the forthcoming space-based interferometers such as the Laser Interferometer Space Antenna (LISA) mission. We have purposely left out from this first version of our "Living Review" article on TDI all the results of more practical and experimental nature, as well as all the aspects of TDI that the data analysts will need to account for when analyzing the LISA TDI data combinations. Our forthcoming "second edition" of this review paper will include these topics.

  3. Current Vaccine Shortages and Delays

    ... CDC.gov . Vaccines and Immunizations Share Compartir Current Vaccine Shortages & Delays Last Updated December 7, 2015 On ... schedule are included in this update. Chart of Vaccines* in Delay or Shortage Vaccines are listed in ...

  4. Ibuprofen-Induced Hypokalemia and Distal Renal Tubular Acidosis: A Patient’s Perceptions of Over-the-Counter Medications and Their Adverse Effects

    Mark D. Salter

    2013-01-01

    Full Text Available We highlight a case of distal renal tubular acidosis secondary to ibuprofen and codeine use. Of particular interest in this case are the patient’s perception of over-the-counter (OTC medication use, her own OTC use prior to admission, and her knowledge of adverse reactions or side effects of these medications prior to taking them.

  5. Characterization of delay propagation in the airport network

    Fleurquin, Pablo; Eguíluz, Victor M

    2013-01-01

    Complex networks provide a suitable framework to model air traffic. Previous works described the world air-traffic network as a graph with direct flights between airports as edges and passenger commercial airports as vertices. In this work we study the US airport network, in the time period 2005-2011. We characterize the topological structure of the network and identify how the plane rotations adjust to it. The reactionary delays are supposed to propagate following the structure of this network. We analyze the properties of flight delays including the total distribution of delays, the delays per day of the week and the hour-by-hour evolution of the delays within each day. We pay special attention to the long-delayed flights, those accumulating delays longer than 12 hours, and study when and where this type of incidences is most common. The goal of this work is to gain a better understanding of the factors contributing to the reactionary delay propagation with the aim of developing models able to realistically...

  6. Neuropsychomotor developmental delay: conceptual map, term definitions, uses and limitations

    Lílian de Fátima Dornelas

    2015-03-01

    Full Text Available OBJECTIVE: 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. DATA SOURCE: 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. DATA SYNTHESIS: 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 1990s. 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. CONCLUSIONS: 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.

  7. Mucosal necrosis of the small intestine in myopathy,encephalopathy, lactic acidosis, and stroke-like episodes syndrome

    Keita Fukuyama; Yasuhide Ishikawa; Tetsuro Ogino; Hidenobu Inoue; Ryoya Yamaoka; Tetsuro Hirose; Tomohiko Nishihira

    2012-01-01

    This report presents a case of massive mucosal necrosis of the small intestine in a patient with mitochondrial myopathy,encephalopathy,lactic acidosis,and stroke-like episodes (MELAS),which particularly affects the brain,nervous system and muscles.A 45-year-old Japanese female,with an established diagnosis of MELAS,presented with vomiting.Computed tomography showed portomesenteric venous gas and pneumatosis intestinalis.She underwent a resection of the small intestine.A microscopic study showed necrosis of the mucosa and vacuolar degeneration of smooth muscle cells in the arterial wall.Immunohistochemistry showed anti-mitochondrial antibody to be highly expressed in the crypts adjacent the necrotic mucosa.The microscopic and immunohistochemical findings suggested the presence of a large number of abnormal mitochondria in MELAS to be closely linked to mucosal necrosis of the small intestine.

  8. Knock-down of hypoxia-induced carbonic anhydrases IX and XII radiosensitizes tumor cells by increasing intracellular acidosis

    Jérôme eDoyen

    2013-01-01

    Full Text Available The relationship between acidosis within the tumor microenvironment and radioresistance of hypoxic tumor cells remains unclear. Previously we reported that hypoxia-induced carbonic anhydrases CAIX and CAXII constitute a robust pHi-regulating system that confers a survival advantage on hypoxic human colon carcinoma LS174Tr cells in acidic microenvironments. Here we investigate the role of acidosis, CAIX and CAXII knock-down in combination with ionizing radiation. Fibroblasts cells (-/+ CAIX and LS174Tr cells (inducible knock-down for ca9/ca12 were analyzed for cell cycle phase distribution and survival after irradiation in extracellular pHo manipulations and hypoxia (1% O2 exposure. Radiotherapy was used to target ca9/ca12-silenced LS174Tr tumors grown in nude mice. We found that diminishing the pHi-regulating capacity of fibroblasts through inhibition of NHE-1 sensitize cells to radiation-induced cell death. Secondly, the pHi-regulating function of CAIX plays a key protective role in irradiated fibroblasts in an acidic environment as accompanied by a reduced number of cells in the radiosensitive phases of the cell cycle. Thirdly, we demonstrate that irradiation of LS174Tr spheroids, silenced for either ca9 or both ca9/ca12, showed a respective 50% and 75% increase in cell death as a result of a decrease in cell number in the radioresistant S phase and a disruption of CA-mediated pHi regulation. Finally, LS174Tr tumor progression was strongly decreased when ca9/ca12 silencing was combined with irradiation in vivo. These findings highlight the combinatory use of radiotherapy with targeting of the pHi-regulating carbonic anhydrases as an anti-cancer strategy.

  9. Effects of grain, fructose, and histidine on ruminal pH and fermentation products during an induced subacute acidosis protocol.

    Golder, H M; Celi, P; Rabiee, A R; Heuer, C; Bramley, E; Miller, D W; King, R; Lean, I J

    2012-04-01

    The effects of grain, fructose, and histidine on ruminal pH and fermentation products were studied in dairy cattle during an induced subacute acidosis protocol. Thirty Holstein heifers were randomly allocated to 5 treatment groups: (1) control (no grain); (2) grain [fed at a crushed triticale dry matter intake (DMI) of 1.2% of body weight (BW)]; (3) grain (0.8% of BW DMI)+fructose (0.4% of BW DMI); (4) grain (1.2% of BW DMI)+histidine (6 g/head); and (5) grain (0.8% of BW DMI)+fructose (0.4% of BW DMI)+histidine (6 g/head) in a partial factorial arrangement. Heifers were fed 1 kg of grain daily with ad libitum access to ryegrass silage and alfalfa hay for 10 d. Feed was withheld for 14 h before challenge day, on which heifers were fed 200 g of alfalfa hay and then the treatment diets immediately thereafter. Rumen samples were collected 5 min after diet ingestion, 60 min later, and at 3 subsequent 50-min intervals. Grain decreased ruminal pH and increased ammonia, total volatile fatty acid (VFA), acetate, butyrate, propionate, and valerate concentrations compared with controls. The addition of grain had no effect on ruminal D- and L-lactate concentrations. Fructose markedly decreased ruminal pH and markedly increased D- and L-lactate concentrations. Fructose increased total VFA and butyrate and decreased valerate concentrations. Although histidine did not have a marked effect on ruminal fermentation, increased concentrations of histamine were observed following feeding. This study demonstrates that the substitution of some grain for fructose can lower ruminal pH and increase VFA and lactate concentrations, warranting further investigation into the role of sugars on the risk of acidosis in dairy cattle. PMID:22459843

  10. Time-Delay Interferometry

    Dhurandhar Sanjeev V.

    2005-07-01

    Full Text Available Equal-arm interferometric 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 and mathematical foundations of TDI as it will be implemented by the forthcoming space-based interferometers such as the Laser Interferometer Space Antenna (LISA mission. We have purposely left out from this first version of our "Living Review" article on TDI all the results of more practical and experimental nature, as well as all the aspects of TDI that the data analysts will need to account for when analyzing the LISA TDI data combinations. Our forthcoming "second edition" of this review paper will include these topics.

  11. Vehicle barrier with access delay

    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.

  12. Concurrent Delay in Construction Disputes

    Cavaleri, Sylvie Cécile

    Delay is one of the issues most frequently encountered in today’s construction industry; it causes significant economic damage to all parties involved. Construction contracts, standard and bespoke, almost invariably consider delay from a perspective of single liability. If the event causing the...... period of delay can potentially be attributed to several events falling within both parties' spheres of responsibility, commonly termed concurrent delay, is rarely regulated in construction contracts in spite of its common occurrence. This book analyses both the theoretical foundations and the practical...... solutions to the issue of concurrent delay in a comparative perspective between common and civil law systems, with an emphasis on Danish and English law....

  13. Synchronizing time delay systems using variable delay in coupling

    Highlights: → Delay and anticipation in coupling function varies with system dynamics. → Delay or anticipation of the synchronized state is independent of system delay. → Stability analysis developed is quite general. → We demonstrate enhanced security in communication. → Generalized synchronization possible over a wide range of parameter mismatch. - Abstract: We present a mechanism for synchronizing time delay systems using one way coupling with a variable delay in coupling that is reset at finite intervals. We present the analysis of the error dynamics that helps to isolate regions of stability of the synchronized state in the parameter space of interest for single and multiple delays. We supplement this by numerical simulations in a standard time delay system like Mackey Glass system. This method has the advantage that it can be adjusted to be delay or anticipatory in synchronization with a time which is independent of the system delay. We demonstrate the use of this method in communication using the bi channel scheme. We show that since the synchronizing channel carries information from transmitter only at intervals of reset time, it is not susceptible to an easy reconstruction.

  14. Long delayed radio echoes

    This thesis describes an experimental program carried out at Stanford over a five-year period. The experiment involved transmitting a radio signal, and tape-recording the output of a receiver gang-tuned with the transmitter for the following 30 s interval. The tapes were later audited for possible LDE. Although none of the possible LDE received reproduces exactly the transmitted signal, many exhibit features that seem unlikely to have been generated except by an LDE mechanism. A mechanism for producing LDE has been studied which involves signal propagation in an electron plasma wave mode at very low group velocity. Modifications to the simplified theory leading to prediction of longer delays are discussed

  15. Location Estimation using Delayed Measurements

    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...

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

    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.

  17. Post-CTS Delay Insertion

    Jianchao Lu; Baris Taskin

    2010-01-01

    A post-clock-tree-synthesis (post-CTS) optimization method is proposed that suggests delay insertion at the leaves of the clock tree in order to implement a limited version of clock skew scheduling. Delay insertion is limited on each clock tree branch simultaneous with a global monitoring of the total amount of delay insertion. The delay insertion for nonzero clock skew operation is performed only at the clock sinks in order to preserve the structure and the optimizations implemented in the c...

  18. Ácidosis D-láctica secundaria a síndrome de intestino corto D-Lactic acidosis secondary to short bowel syndrome

    M. J. Tapia Guerrero; Olveira Fuster, G.; M. Bravo Utrera; N. Colomo Rodríguez; Fernández García, J. C.

    2010-01-01

    El síndrome de intestino corto aparece por la reducción de la superficie absortiva intestinal efectiva por pérdida funcional o anatómica de una parte de intestino delgado. Se presenta el caso de una mujer de 35 años con síndrome de intestino corto severo secundario a isquemia intestinal aguda en la edad adulta, que presenta a los 5 años de evolución episodios de mareos con inestabilidad en la marcha y pérdida de fuerza en las manos, llegándose al diagnóstico de acidosis D-láctica. La acidosis...

  19. Arrhythmogenic Biophysical Phenotype for SCN5A Mutation S1787N Depends upon Splice Variant Background and Intracellular Acidosis.

    Rou-Mu Hu

    Full Text Available SCN5A is a susceptibility gene for type 3 long QT syndrome, Brugada syndrome, and sudden infant death syndrome. INa dysfunction from mutated SCN5A can depend upon the splice variant background in which it is expressed and also upon environmental factors such as acidosis. S1787N was reported previously as a LQT3-associated mutation and has also been observed in 1 of 295 healthy white controls. Here, we determined the in vitro biophysical phenotype of SCN5A-S1787N in an effort to further assess its possible pathogenicity.We engineered S1787N in the two most common alternatively spliced SCN5A isoforms, the major isoform lacking a glutamine at position 1077 (Q1077del and the minor isoform containing Q1077, and expressed these two engineered constructs in HEK293 cells for electrophysiological study. Macroscopic voltage-gated INa was measured 24 hours after transfection with standard whole-cell patch clamp techniques. We applied intracellular solutions with pH7.4 or pH6.7. S1787N in the Q1077 background had WT-like INa including peak INa density, activation and inactivation parameters, and late INa amplitude in both pH 7.4 and pH 6.7. However, with S1787N in the Q1077del background, the percentages of INa late/peak were increased by 2.1 fold in pH 7.4 and by 2.9 fold in pH 6.7 when compared to WT.The LQT3-like biophysical phenotype for S1787N depends on both the SCN5A splice variant and on the intracellular pH. These findings provide further evidence that the splice variant and environmental factors affect the molecular phenotype of cardiac SCN5A-encoded sodium channel (Nav1.5, has implications for the clinical phenotype, and may provide insight into acidosis-induced arrhythmia mechanisms.

  20. Persistent lactic acidosis in neonatal hypoxic-ischaemic encephalopathy correlates with EEG grade and electrographic seizure burden.

    Murray, D M

    2012-02-03

    BACKGROUND: Predicting at birth which infants with perinatal hypoxic-ischaemic injury will progress to significant encephalopathy remains a challenge. OBJECTIVE: To determine whether lactic acidosis at birth in asphyxiated neonates could predict the grade of EEG encephalopathy by examining the relationship between time taken for the normalisation of lactate, severity of encephalopathy and seizure burden. METHODS: Continuous early video-EEG monitoring was performed in babies at risk for hypoxic-ischaemic encephalopathy. Encephalopathy was graded from the EEG data. Total seizure burden (seconds) was calculated for each baby. Initial blood gas measurements of pH, base deficit and lactate were taken within 30 minutes of delivery. Time to normal serum lactate was determined in hours from birth for each infant. RESULTS: All 50 term infants had raised initial serum lactate (median (lower, upper quartiles) 11.7 (10.2, 14.9)). There were no significant differences between the initial serum lactate, pH and base deficit in infants with normal\\/mildly abnormal (n = 24), moderately abnormal (n = 14), severely abnormal (n = 5) and inactive EEGs (n = 7). Time to normal lactate varied significantly with EEG grade (median (lower, upper quartile) 6.0 (4.1, 9.5) for mild\\/normal EEG, 13.5 (6.8, 23.5) moderate EEG, 41.5 (30.0, 55.5) severe group, 12.0 (8.1, 21.5) inactive group; p<0.001). Time to normal lactate correlated significantly with EEG seizure burden (seconds; R = 0.446, p = 0.002). Mean (SD) time to normal lactate was 10.0 (7.2) hours in infants who did not have seizures and 27.3 (19.0) hours in the 13 infants with electrographic seizures (p = 0.002). CONCLUSIONS: Serum lactate levels in the first 30 minutes of life do not predict the severity of the ensuing encephalopathy. In contrast, sustained lactic acidosis is associated with severe encephalopathy on EEG and correlates with seizure burden.

  1. Deficiency of the iron-sulfur clusters of mitochondrial reduced nicotinamide-adenine dinucleotide-ubiquinone oxidoreductase (complex I) in an infant with congenital lactic acidosis.

    Moreadith, R W; Batshaw, M L; Ohnishi, T.; Kerr, D.; Knox, B; Jackson, D; Hruban, R; Olson, J; Reynafarje, B; Lehninger, A L

    1984-01-01

    We report the case of an infant with hypoglycemia, progressive lactic acidosis, an increased serum lactate/pyruvate ratio, and elevated plasma alanine, who had a moderate to profound decrease in the ability of mitochondria from four organs to oxidize pyruvate, malate plus glutamate, citrate, and other NAD+-linked respiratory substrates. The capacity to oxidize the flavin adenine dinucleotide-linked substrate, succinate, was normal. The most pronounced deficiency was in skeletal muscle, the le...

  2. Acidosis Sensing Receptor GPR65 Correlates with Anti-Apoptotic Bcl-2 Family Member Expression in CLL Cells: Potential Implications for the CLL Microenvironment

    Rosko, Ashley E.; McColl, Karen S.; Zhong, Fei; Ryder, Christopher B; Chang, Ming-Jin; Sattar, Abdus; Caimi, Paolo F.; Hill, Brian T; Al-harbi, Sayer; Almasan, Alexandru; Distelhorst, Clark W.

    2014-01-01

    The tumor microenvironment is generally an acidic environment, yet the effect of extracellular acidosis on chronic lymphocytic leukemia (CLL) is not well established. Here we are the first to report that the extracellular acid sensing G-protein coupled receptor, GPR65, is expressed in primary CLL cells where its level correlate strongly with anti-apoptotic Bcl-2 family member levels. GPR65 expression is found normally within the lymphoid lineage and has not been previously reported in CLL. We...

  3. Distal Renal Tubular Acidosis, Hypokalemic Paralysis, Nephrocalcinosis, Primary Hypothyroidism, Growth Retardation, Osteomalacia and Osteoporosis Leading to Pathological Fracture: A Case Report

    Mayada Mohammad Swar; Mohammad Mizanur Rahman; Khairy Mostafa Sharkawi; Basak, Ramen C.

    2011-01-01

     Renal tubular acidosis (RTA) is a constellation of syndromes arising from different derangements of tubular acid transport. Recent advances in the biology of urinary acidification have allowed us to discern various molecular mechanisms responsible for these syndromes. RTA often presents as renal stone disease with nephrocalcinosis, ricket/osteomalacia and growth retardation in children with ultimate short stature in adulthood. The case reported here has features of distal renal tubular acido...

  4. The diversity of the fecal bacterial community and its relationship with the concentration of volatile fatty acids in the feces during subacute rumen acidosis in dairy cows

    Mao Shengyong; Zhang Ruiyang; Wang Dongsheng; Zhu Weiyun

    2012-01-01

    Abstract Background Sub-acute ruminal acidosis (SARA) is a well-recognized digestive disorder found in particular in well-managed dairy herds. SARA can result in increased flow of fermentable substrates to the hindgut, which can increase the production of volatile fatty acids, alter the structure of the microbial community, and have a negative effect on animal health and productivity. However, little is known about changes in the structure of the microbial community and its relationship with ...

  5. Delayed unlatching mechanism

    Bzorgi, Fariborz M.

    2015-05-19

    In various embodiments an apparatus is presented for securing a structure such as a door, window, hatch, or gate that moves between an open and a closed position relative to a fixed structure to provide or deny access to a compartment, a room, an outdoor area, or a facility. Various embodiments provide a delay in opening the closure of sufficient duration to frustrate a rapid activation that might be desired by a person who is attempting to pass through the closure for some illicit purpose. Typically, hydraulics are used to activate the apparatus and no electrical energy or electronic signals are employed. In one embodiment, a plurality of actuations of a hand lever operates a hydraulic pump that moves a locking bolt from a first position in which a locking bolt is engaged with a recess in the fixed structure (preventing opening of a gate) to a second position in which the locking bolt is disengaged from the recess to permit opening of the gate.

  6. Delayed breast implant reconstruction

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne;

    2012-01-01

    We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... the period between 1999 and 2006. A history of radiation therapy was associated with increased risk of severe capsular contracture for 1- and 2-stage procedures, with adjusted hazard ratios (HR) of 3.3 (95% confidence interval [CI]: 0.9-12.4) and 7.2 (95% CI: 2.4-21.4), respectively. Similarly, a...... history of radiation therapy was associated with a non-significantly increased risk of reoperation after both 1-stage (HR = 1.4; 95% CI: 0.7-2.5) and 2-stage (HR = 1.6; 95% CI: 0.9-3.1) procedures. Reconstruction failure was highest (13.2%) in the 2-stage procedures with a history of radiation therapy...

  7. Delay Adjusted Incidence Infographic

    This Infographic shows the National Cancer Institute SEER Incidence Trends. The graphs show the Average Annual Percent Change (AAPC) 2002-2011. For Men, Thyroid: 5.3*,Liver & IBD: 3.6*, Melanoma: 2.3*, Kidney: 2.0*, Myeloma: 1.9*, Pancreas: 1.2*, Leukemia: 0.9*, Oral Cavity: 0.5, Non-Hodgkin Lymphoma: 0.3*, Esophagus: -0.1, Brain & ONS: -0.2*, Bladder: -0.6*, All Sites: -1.1*, Stomach: -1.7*, Larynx: -1.9*, Prostate: -2.1*, Lung & Bronchus: -2.4*, and Colon & Rectum: -3/0*. For Women, Thyroid: 5.8*, Liver & IBD: 2.9*, Myeloma: 1.8*, Kidney: 1.6*, Melanoma: 1.5, Corpus & Uterus: 1.3*, Pancreas: 1.1*, Leukemia: 0.6*, Brain & ONS: 0, Non-Hodgkin Lymphoma: -0.1, All Sites: -0.1, Breast: -0.3, Stomach: -0.7*, Oral Cavity: -0.7*, Bladder: -0.9*, Ovary: -0.9*, Lung & Bronchus: -1.0*, Cervix: -2.4*, and Colon & Rectum: -2.7*. * AAPC is significantly different from zero (p<.05). Rates were adjusted for reporting delay in the registry. www.cancer.gov Source: Special section of the Annual Report to the Nation on the Status of Cancer, 1975-2011.

  8. Geometric time delay interferometry

    The space-based gravitational-wave observatory LISA, a NASA-ESA mission to be launched after 2012, will achieve its optimal sensitivity using time delay interferometry (TDI), a LISA-specific technique needed to cancel the otherwise overwhelming laser noise in the interspacecraft phase measurements. The TDI observables of the Michelson and Sagnac types have been interpreted physically as the virtual measurements of a synthesized interferometer. In this paper, I present Geometric TDI, a new and intuitive approach to extend this interpretation to all TDI observables. Unlike the standard algebraic formalism, Geometric TDI provides a combinatorial algorithm to explore exhaustively the space of second-generation TDI observables (i.e., those that cancel laser noise in LISA-like interferometers with time-dependent arm lengths). Using this algorithm, I survey the space of second-generation TDI observables of length (i.e., number of component phase measurements) up to 24, and I identify alternative, improved forms of the standard second-generation TDI observables. The alternative forms have improved high-frequency gravitational-wave sensitivity in realistic noise conditions (because they have fewer nulls in the gravitational-wave and noise response functions), and are less susceptible to instrumental gaps and glitches (because their component phase measurements span shorter time periods)

  9. Geometric Time Delay Interferometry

    Vallisneri, M

    2005-01-01

    The space-based gravitational-wave observatory LISA, a NASA--ESA mission to be launched after 2012, will achieve its optimal sensitivity using Time Delay Interferometry (TDI), a LISA-specific technique needed to cancel the otherwise overwhelming laser noise in the inter-spacecraft phase measurements. In this paper I present_Geometric TDI_, a new, intuitive approach to derive the TDI observables and to understand them as the virtual measurements of a synthesized multi-beam interferometer. Unlike the standard algebraic formalism, Geometric TDI provides a combinatorial algorithm to explore exhaustively the space of _second-generation_ TDI observables (i.e., those that cancel laser noise in LISA-like interferometers with time-dependent armlengths). Using this algorithm, I survey the space of second-generation TDI observables of length (i.e., number of component phase measurements) up to 24, and I identify alternative, improved forms of the standard second-generation TDI observables. The alternative forms have imp...

  10. Magnetic bearing optical delay line

    Dool, T.C. van den; Kamphues, F.G.; Fouss, B.; Henrioulle, K.; Hogenhuis, H.

    2004-01-01

    TNO TPD, in close cooperation with Micromega-Dynamics and Dutch Space, has developed an advanced Optical Delay Line (ODL) for use in PRIMA, GENIE and other ground based interferometers. The delay line design is modular and flexible, which makes scaling for other applications a relatively easy task.

  11. Consumer Procrastination and Purchase Delay

    Darpy, Denis

    2000-01-01

    Recent research on purchase delay have developed numerous situational and individual causes. This paper proposes Consumer Procrastination to conceptualize the individual factor which influence people to chronically delay their purchases. Consumer Procrastination is measured with a new scale. An experiment is designed to show the importance of its impact on the decision to not choose along with context effects.

  12. #FakeNobelDelayReasons

    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.    

  13. Delayed Reinforcement of Operant Behavior

    Lattal, Kennon A.

    2010-01-01

    The experimental analysis of delay of reinforcement is considered from the perspective of three questions that seem basic not only to understanding delay of reinforcement but also, by implication, the contributions of temporal relations between events to operant behavior. The first question is whether effects of the temporal relation between…

  14. 奶牛瘤胃酸中毒的发病机制和防治措施%The Mechanism and Prevention of Dairy Cow Rumen Acidosis

    杨艳玲; 沈赞明

    2015-01-01

    The cow rumen acidosis is caused by the high concentrated feed used .It has improved ruminal pH ,microbial flora ,eventually led to a decline in milk production and milk quality ,triggering a series of nutritional and metabolic disease ,great harm to dairy production .This pa‐per reviews several aspects of acute acidosis and subacute ruminal acidosis in the etiology ,pathogenesis and prevention measures to provide sci‐entific and theoretical basis for actual production .%奶牛瘤胃酸中毒是由于大量饲喂易发酵的碳水化合物日粮引起的,造成奶牛瘤胃酸度增加,微生物菌群失调,最终导致奶牛产奶量和乳品质下降,进而引发一系列的营养代谢病,对奶牛生产危害极大。文章就急性瘤胃酸中毒和亚急性瘤胃酸中毒的发病病因、发病机理及防治措施等几方面进行综述,为实际生产提供科学的理论依据。

  15. Hyperlactatemia and metabolic acidosis in critically ill patient%重症患者的高乳酸血症与代谢性酸中毒

    杜微; 刘大为

    2011-01-01

    高乳酸血症和代谢性酸中毒的关系一直是讨论的热点,涉及到休克复苏、机体内环境稳定及营养支持等方面.一方面重症患者组织低灌注时无氧酵解增加带来的乳酸生成增多会加重代谢性酸中毒,而另一方面乳酸在器官水平和细胞水平被利用会引起血乳酸水平降低进而减轻代谢性酸中毒,最终血乳酸水平取决于两者的平衡.%The relationship between hyperlactatemia and metabolic acidosis, which may involve shock resuscitation,homoiostasis, and nutritional support, remains a hot topic. On one hand, increased production of lac-tate due to anaerobic glycolysis during tissue hypoperfusion can aggravate metabolic acidosis; on the other hand,the utilization of lactate at organ and cell levels may lower blood lactate level, and thus alleviate metabolic acidosis.The ultimate blood lactate level depends on the balance of these two action mechanisms.

  16. Time-delay damping theory

    洪峰

    2002-01-01

    In this paper, existing damping theories are briefly reviewed. On the basis of the existing damping theories, a new kind of damping theory, i.e., the time-delay damping theory, is developed. In the time-delay damping theory, the damping force is considered to be directly proportional to the increment of displacement. The response analysis of an SDOF time-delay damping system is carried out, and the methods for obtaining the solution for a time-delay damping system in the time domain as well as the frequency domain are given. The comparison between results from different damping theories shows that the time-delay damping theory is both reasonable and convenient.

  17. Analog Group Delay Equalizers Design Based on Evolutionary Algorithm

    M. Laipert

    2006-04-01

    Full Text Available This paper deals with a design method of the analog all-pass filter designated for equalization of the group delay frequency response of the analog filter. This method is based on usage of evolutionary algorithm, the Differential Evolution algorithm in particular. We are able to design such equalizers to be obtained equal-ripple group delay frequency response in the pass-band of the low-pass filter. The procedure works automatically without an input estimation. The method is presented on solving practical examples.

  18. Delayed radiation neuropathy

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author)

  19. Parameter estimation for time-delay chaotic system by particle swarm optimization

    The knowledge about time delays and parameters is very important for control and synchronization of time-delay chaotic system. In this paper, parameter estimation for time-delay chaotic system is given by treating the time delay as an additional parameter. The parameter estimation is converted to an optimization problem, which finds a best parameter combination such that an objective function is minimized. Particle swarm optimization (PSO) is used to optimize the objective function through particles' cooperation and evolution. Two illustrative examples are given to show the validity of the proposed method.

  20. The Evolution of Tidal Debris

    Mihos, C

    2004-01-01

    Galaxy interactions expel a significant amount of stars and gas into the surrounding environment. I review the formation and evolution of the tidal debris spawned during these collisions, and describe how this evolution depends on the large scale environment in which the galaxies live. In addition to acting as a long-lived tracer of the interaction history of galaxies, the evolution of this material -- on both large scales and small -- has important ramifications for galactic recycling processes, the feeding of the intracluster light and intracluster medium within galaxy clusters, and the delayed formation of galactic disks and dwarf galaxies.

  1. Attosecond delays in molecular photoionization

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

    2016-01-01

    We report measurements of energy-dependent attosecond photoionization delays between the two outer-most 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 $\\sim$110 as. The unstructured continua of H$_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.

  2. Time Delay in Molecular Photoionization

    Hockett, P; Villeneuve, D M; Corkum, P B

    2015-01-01

    Time-delays in the photoionization of molecules are investigated. As compared to atomic ionization, the time-delays expected from molecular ionization present a much richer phenomenon, with a strong spatial dependence due to the anisotropic nature of the molecular scattering potential. We investigate this from a scattering theory perspective, and make use of molecular photoionization calculations to examine this effect in representative homonuclear and hetronuclear diatomic molecules, nitrogen and carbon monoxide. We present energy and angle-resolved maps of the Wigner delay time for single-photon valence ionization, and discuss the possibilities for experimental measurements.

  3. Nonlinear dynamics of neural delayed feedback

    Longtin, A.

    1990-01-01

    Neural delayed feedback is a property shared by many circuits in the central and peripheral nervous systems. The evolution of the neural activity in these circuits depends on their present state as well as on their past states, due to finite propagation time of neural activity along the feedback loop. These systems are often seen to undergo a change from a quiescent state characterized by low level fluctuations to an oscillatory state. We discuss the problem of analyzing this transition using techniques from nonlinear dynamics and stochastic processes. Our main goal is to characterize the nonlinearities which enable autonomous oscillations to occur and to uncover the properties of the noise sources these circuits interact with. The concepts are illustrated on the human pupil light reflex (PLR) which has been studied both theoretically and experimentally using this approach. 5 refs., 3 figs.

  4. Birthrates and delay times of Type Ia supernovae

    Wang, Bo; Han, Yunkun; Lei, Zhenxin; Luo, Yangping; Han, Zhanwen; 10.1007/s11433-010-0152-8

    2010-01-01

    Type Ia supernovae (SNe Ia) play an important role in diverse areas of astrophysics, from the chemical evolution of galaxies to observational cosmology. However, the nature of the progenitors of SNe Ia is still unclear. In this paper, according to a detailed binary population synthesis study, we obtained SN Ia birthrates and delay times from different progenitor models, and compared them with observations. We find that the Galactic SN Ia birthrate from the double-degenerate (DD) model is close to those inferred from observations, while the birthrate from the single-degenerate (SD) model accounts for only about 1/2-2/3 of the observations. If a single starburst is assumed, the distribution of the delay times of SNe Ia from the SD model is a weak bimodality, where the WD + He channel contributes to the SNe Ia with delay times shorter than 100Myr, and the WD + MS and WD + RG channels to those with age longer than 1Gyr.

  5. Birthrates and delay times of Type Ia supernovae

    2010-01-01

    Type Ia supernovae (SNe Ia) play an important role in diverse areas of astrophysics, from the chemical evolution of galaxies to observational cosmology. However, the nature of the progenitors of SNe Ia is still unclear. In this paper, according to a detailed binary population synthesis study, we obtained SN Ia birthrates and delay times from different progenitor models, and compared them with observations. We find that the Galactic SN Ia birthrate from the double-degenerate (DD) model is close to those inferred from observations, while the birthrate from the single-degenerate (SD) model accounts for only about 1/2-2/3 of the observations. If a single starburst is assumed, the distribution of the delay times of SNe Ia from the SD model is a weak bimodality, where the WD + He channel contributes to the SNe Ia with delay times shorter than 100 Myr, and the WD + MS and WD + RG channels to those with age longer than 1 Gyr.

  6. Delayed population models with Allee effects and exploitation.

    Liz, Eduardo; Ruiz-Herrera, Alfonso

    2015-02-01

    Allee effects make populations more vulnerable to extinction, especially under severe harvesting or predation. Using a delay-differential equation modeling the evolution of a single-species population subject to constant effort harvesting, we show that the interplay between harvest strength and Allee effects leads not only to collapses due to overexploitation; large delays can interact with Allee effects to produce extinction at population densities that would survive for smaller time delays. In case of bistability, our estimations on the basins of attraction of the two coexisting attractors improve some recent results in this direction. Moreover, we show that the persistent attractor can exhibit bubbling: a stable equilibrium loses its stability as harvesting effort increases, giving rise to sustained oscillations, but higher mortality rates stabilize the equilibrium again. PMID:25811339

  7. Delays and networked control systems

    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. .

  8. Language Delays in Toddlers: Information for Parents

    ... Stages Listen Español Text Size Email Print Share Language Delays in Toddlers: Information for Parents Page Content ... situation or repeats scripts from TV Delays in language Delays in language are the most common types ...

  9. Optimization of the concrete delayed deformations by Kalman filter

    Imperviousness of French nuclear power plants containments has to secure radioactive products confinement during incident or accident. Temporal evolution of containments is obtained through the numerical model Code Aster that purpose is to detect if some fissure could appear and as a consequence, imperviousness lost. In parallel, sensors are placed all around the containments to follow real time deformations. In this paper, Kalman filter analysis of an extensometer data is used to optimize eight parameters of the numerical model Code Aster. This method allows us to improve the concrete delayed behaviors modelization and supplies uncertainties to the forecast of the containment evolution. (author)

  10. Tunable silicon CROW delay lines

    Morichetti, Francesco; Canciamilla, Antonio; Torregiani, Matteo; Ferrari, Carlo; Melloni, Andrea; Martinelli, Mario

    2010-05-01

    Tunable coupled resonator optical waveguides (CROWs) are powerful and versatile devices that can be used to dynamically control the delay of optical data streams on chip. In this contribution we show that CROW delay lines fabricated on a silicon on insulator (SOI) platform are suitable for applications in the emerging scenario of optical systems at 100 Gbit/s. Issues concerning technology, design, limits and applications of SOI CROWs are discussed. The performances of silicon CROW delay lines activated by thermal tuning are compared to those of glass CROW in terms of power consumption, thermal crosstalk and reconfiguration speed. The continuous delay of 10-ps long optical pulses by 8 bit length is demonstrated by using a silicon CROW with a bandwidth of 87 GHz and made of 12 RRs. At 100 Gbit/s this structure provides comparable figures of merit (fractional delay of 0.75 bit/RR and fractional loss of 0.7 dB per bit-delay) of state-of-the art glass CROW operating at 10 Gbit/s, yet the area of the latter being three order of magnitude larger. The compatibility of silicon CROW with the emerging 100 Gbit/s systems is demonstrated by showing error-free phase-preserving propagation of a 100 Gbit/s return-to-zero (RZ) polarization-division-multiplexing (PolDM) differential quaternary phase shit keying (DQPSK) signal dynamically delayed by the CROW. It is also demonstrated that a silicon CROW can be used in a PolDM system to introduce a polarization selective delay in order to optimize the time interleaving of the two orthogonally polarized data streams.

  11. Deconstructing delayed posttraumatic stress disorder

    Smid, G.E.

    2011-01-01

    According to the Diagnostic and Statistical Manual of Mental Disorders, delayed posttraumatic stress disorder (PTSD) must be diagnosed in individuals fulfilling criteria for PTSD if the onset of symptoms is at least six months after the trauma. The purpose of this thesis was to establish the prevalence of delayed PTSD and to examine factors that may explain its occurrence. We conducted a meta-analysis and examined prospective data from disaster survivors, unaccompanied refugee minors, and arm...

  12. Systematics in delayed neutron yields

    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)

  13. Basin stability in delayed dynamics

    Leng, Siyang; Lin, Wei; Kurths, Jürgen

    2016-02-01

    Basin stability (BS) is a universal concept for complex systems studies, which focuses on the volume of the basin of attraction instead of the traditional linearization-based approach. It has a lot of applications in real-world systems especially in dynamical systems with a phenomenon of multi-stability, which is even more ubiquitous in delayed dynamics such as the firing neurons, the climatological processes, and the power grids. Due to the infinite dimensional property of the space for the initial values, how to properly define the basin’s volume for delayed dynamics remains a fundamental problem. We propose here a technique which projects the infinite dimensional initial state space to a finite-dimensional Euclidean space by expanding the initial function along with different orthogonal or nonorthogonal basis. A generalized concept of basin’s volume in delayed dynamics and a highly practicable calculating algorithm with a cross-validation procedure are provided to numerically estimate the basin of attraction in delayed dynamics. We show potential applicabilities of this approach by applying it to study several representative systems of biological or/and physical significance, including the delayed Hopfield neuronal model with multistability and delayed complex networks with synchronization dynamics.

  14. Schwannoma of the Median Nerve: Diagnosis Sometimes Delayed

    Monsef Boufettal; Mohamed Azouz; Abdelkarim Rhanim; Mohamed Abouzahir; Mustapha Mahfoud; Ahmed El Bardouni; Mohamed S. Berrada; Moradh El Yaacoubi

    2014-01-01

    Schwannoma is a tumor that develops from nerve sheath. The authors report an unusual case of schwannoma of the median nerve (MN) that remained asymptomatic for four years. The diagnosis was based on MRI (magnetic resonance imaging) and histopathological examination. Surgical removal is usually curative. The asymptomatic character of the tumor and its slow evolution remain an essential factor in diagnosis delays. This tumor has a good prognosis with a low recurrence rate and potential for mali...

  15. Dialysis Disequilibrium Syndrome: Brain death following hemodialysis for metabolic acidosis and acute renal failure – A case report

    Bagshaw Sean M

    2004-08-01

    Full Text Available Abstract Background Dialysis disequilibrium syndrome (DDS is the clinical phenomenon of acute neurologic symptoms attributed to cerebral edema that occurs during or following intermittent hemodialysis (HD. We describe a case of DDS-induced cerebral edema that resulted in irreversible brain injury and death following acute HD and review the relevant literature of the association of DDS and HD. Case Presentation A 22-year-old male with obstructive uropathy presented to hospital with severe sepsis syndrome secondary to pneumonia. Laboratory investigations included a pH of 6.95, PaCO2 10 mmHg, HCO3 2 mmol/L, serum sodium 132 mmol/L, serum osmolality 330 mosmol/kg, and urea 130 mg/dL (46.7 mmol/L. Diagnostic imaging demonstrated multifocal pneumonia, bilateral hydronephrosis and bladder wall thickening. During HD the patient became progressively obtunded. Repeat laboratory investigations showed pH 7.36, HCO3 19 mmol/L, potassium 1.8 mmol/L, and urea 38.4 mg/dL (13.7 mmol/L (urea-reduction-ratio 71%. Following HD, spontaneous movements were absent with no pupillary or brainstem reflexes. Head CT-scan showed diffuse cerebral edema with effacement of basal cisterns and generalized loss of gray-white differentiation. Brain death was declared. Conclusions Death is a rare consequence of DDS in adults following HD. Several features may have predisposed this patient to DDS including: central nervous system adaptations from chronic kidney disease with efficient serum urea removal and correction of serum hyperosmolality; severe cerebral intracellular acidosis; relative hypercapnea; and post-HD hemodynamic instability with compounded cerebral ischemia.

  16. Clinical Significance of Early Correction of Metabolic Acidosis in Patients with Chronic Kidney Disease%早期纠正慢性肾脏病患者代谢性酸中毒的临床意义

    田秋菊

    2015-01-01

    blood pressure before and after treatment between two groups. Conclusion Bicarbonate and diet therapy can cor-rect metabolic acidosis in patients with CKD and TCO2> 22mmol/L.They can delay the progress of renal function and have renal protection effect, and do not cause electrolyte disorders and high blood pressure.

  17. Delay Independent Criterion for Multiple Time-delay Systems

    Chang, C. J.; Liu, K. F. R.; Yeh, K.; Chen, C. W.; Chung, P. Y.

    Based on the fuzzy Lyapunov method, this work addresses the stability conditions for nonlinear systems with multiple time delays to ensure the stability of building structure control systems. The delay independent conditions are derived via the traditional Lyapunov and fuzzy Lyapunov methods for multiple time-delay systems as approximated by the Tagagi-Sugeno (T-S) fuzzy model. The fuzzy Lyapunov function is defined as a fuzzy blending of quadratic Lyapunov functions. A parallel distributed compensation (PDC) scheme is utilized to construct a global fuzzy logic control (FLC) by blending all linear local state feedback controllers in the controller design procedure. Furthermore, the H infinity performance and robustness of the design for modeling errors also need to be considered in the stability conditions.

  18. Does high-dose metformin cause lactic acidosis in type 2 diabetic patients after CABG surgery? A double blind randomized clinical trial

    Rahman Ghafari

    2011-06-01

    Full Text Available Metformin is a dimethyl biguanide oral anti-hyperglycemic agent. Lactic acidosis due to metformin is a fatal metabolic condition that limits its use in patients in poor clinical condition, consequently reducing the number of patients who benefit from this medication. In a double blind randomized clinical trial, we investigated 200 type 2 diabetic patients after coronary artery bypass surgery in the open heart ICU of the Mazandaran Heart Center, and randomly assigned them to equal intervention and control groups. The intervention group received regular insulin infusion along with 2 metformin 500 mg tablets every twelve hours, while the control group received only intravenous insulin with 2 placebo tablets every twelve hours. Lactate level, pH, base excess, blood glucose and serum creatinine were measured over five 12 h periods, with data averaged for each period. The primary outcome in this study was high lactate levels. Comparison between the 2 groups was made by independent Student’s t-test. To compare changes in multiple measures in each group and analysis of group interaction, a repeated measurement ANOVA test was used. There was no significant difference between the 2 groups regarding pH, base excess, or bicarbonate intake (P>0.05. No patient showed lactic acidosis in either group. Lactate levels were 23.0 vs 23.4 in the insulin-metformin and insulin only groups when the study was started, respectively. At the end of the study, those levels were 18.7 vs 18.9, respectively. In addition, the ANOVA repeated measurement test did not show a significant difference in terms of changes in the amount of lactate level between the 2 groups during the five measurement tests of the study period (P>0.05. High-dose metformin (1,000 mg twice daily with insulin does not cause lactic acidosis in type 2 diabetic patients after coronary artery

  19. Evaluating in vitro dose-response effects of Lavandula officinalis essential oil on rumen fermentation characteristics, methane production and ruminal acidosis

    Yadeghari, Shahin; Malecky, Mostafa; Dehghan Banadaky, Mehdi; Navidshad, Bahman

    2015-01-01

    Four in vitro experiments (Exp.) were conducted to evaluate lavender essential oil (LEO) effects at 0 (control), 250 (low dose), 500 (medium dose), 750 and 1000 µL per L (high doses) of incubation medium on rumen gas production kinetics (Exp.1), ruminal digestibility and fermentation (Exp.2), methane production (Exp.3) and rumen acidosis (Exp.4). The asymptote of gas production (A) increased quadratically (p < 0.001), but the lag phase (L) increased (p = 0.003), and gas production rate (µ) de...

  20. Atp6v0a4 knockout mouse is a model of distal renal tubular acidosis with hearing loss, with additional extrarenal phenotype

    Elizabeth E. Norgett; Golder, Zoe J.; Lorente-Cánovas, Beatriz; Ingham, Neil; Steel, Karen P; Karet Frankl, Fiona E.

    2012-01-01

    Autosomal recessive distal renal tubular acidosis (dRTA) is a severe disorder of acid–base homeostasis, often accompanied by sensorineural deafness. We and others have previously shown that mutations in the tissue-restricted a4 and B1 subunits of the H+-ATPase underlie this syndrome. Here, we describe an Atp6v0a4 knockout mouse, which lacks the a4 subunit. Using β-galactosidase as a reporter for the null gene, developmental a4 expression was detected in developing bone, nose, eye, and skin, i...

  1. 49 CFR 236.563 - Delay time.

    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....

  2. On Stability of Linear Time-Delay Systems with Multiple Time-Varying Delays

    Park, Gwang-Seok; Choi, Ho-Lim

    In this letter, delay-dependent stability criterion for linear time-delay systems with multiple time varying delays is proposed by employing the Lyapunov-Krasovskii functional approach and integral inequality. By the N-segmentation of delay length, we obtain less conservative results on the delay bounds which guarantee the asymptotic stability of the linear time-delay systems with multiple time varying delays. Simulation results show that the proposed stability criteria are less conservative than several other existing criteria.

  3. Time delay in quantum scattering

    As is well known, the knowledge of the scattering cross section and its angular dependence, as a function of energy, is insufficient to determine the phase shifts uniquely. This led Eisenbud and Wigner to propose the measurement of the scattering lifetime or time delay as an additional independent datum. A rigorous time-dependent study of time delay within the framework of Hilbert space formalism is presented. Specifically, Martin's theory of time delay and the validity of the Eisenbud-Wigner time delay formula are extended to spherically symmetric potentials satisfying the asymptotic fall-off rate V(r) → O(r/sup -2-epsilon/). This extension is obtained by use of a maximal estimate of the rate of convergence of the asymptotic condition and the elimination of Martin's requirement that the scattering operator S be three times differentiable with respect to the free-particle Hamiltonian H0. Also presented are related results on the total time a quantum particle spends inside some bounded regions in position space. It is then proved that any two free particles having identical distributions of energy and angular momentum take exactly identical expectation values for the transit time across an arbitrary spherical region centered at the origin in position space. Ways to extend this result to nonfree Hamiltonians are indicated. Finally, the relationship between the position operator and the Eisenbud-Wigner time delay operator is examined. It is shown that the usual method of calculating time delay based on the classical analysis of the position operator is not exact

  4. Chaos in the delay logistic equation with discontinuous delays

    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.

  5. A quantum delayed choice experiment

    Peruzzo A.; Shadbolt P.; Brunner N.; Popescu S.; O'Brien J.L.

    2012-01-01

    Quantum systems exhibit particle-like or wave-like behaviour depending on the experimental apparatus they are confronted by. This wave-particle duality is at the heart of quantum mechanics, and is fully captured in Wheeler's famous delayed choice gedanken experiment. In this variant of the double slit experiment, the observer chooses to test either the particle or wave nature of a photon after it has passed through the slits. Here we report on a quantum delayed choice experiment, based on a q...

  6. Importance of delayed neutrons in nuclear research

    The report presents a comprehensive review of the uses ofβ-, n delayed neutrons in nuclear research with special emphasis on energy spectra and reactor applications. The review covers the following aspects : (1) delayed neutron in reactor analysis, (2) absolute delayed neutron yield, (3) delayed neutron decay constants, (4) delayed neutron energy spectra and their importance in high accuracy criticality calculations and precise evaluation of reactor kinetics characteristics, particularly fast breeders, (5) a chronological account of the developments in the measurement of delayed neutron energy spectra, both aggregate (composite) and from individual fission product isotopes during the last fifty years or so, (6) major spectrometry techniques for measuring delayed neutron energy spectra, (7) spectral analysis, (8) calculations of delayed neutron energy spectra from precursor data, and (9) sensitivity analysis of fast reactor dynamic behaviour to delayed neutron energy spectra. Finally the report recommends a number of areas for future research work on delayed neutrons. (author). refs., 49 figs., 10 tabs

  7. (Uncommon) Mechanisms of Branchial Ammonia Excretion in the Common Carp (Cyprinus carpio) in Response to Environmentally Induced Metabolic Acidosis.

    Wright, Patricia A; Wood, Chris M; Hiroi, Junya; Wilson, Jonathan M

    2016-01-01

    Freshwater fishes generally increase ammonia excretion in acidic waters. The new model of ammonia transport in freshwater fish involves an association between the Rhesus (Rh) protein Rhcg-b, the Na(+)/H(+) exchanger (NHE), and a suite of other membrane transporters. We tested the hypothesis that Rhcg-b and NHE3 together play a critical role in branchial ammonia excretion in common carp (Cyprinus carpio) chronically exposed to a low-pH environment. Carp were exposed to three sequential environmental treatments-control pH 7.6 water (24 h), pH 4.0 water (72 h), and recovery pH 7.6 water (24 h)-or in a separate series were simply exposed to either control (72 h) or pH 4.0 (72 h) water. Branchial ammonia excretion was increased by ∼2.5-fold in the acid compared with the control period, despite the absence of an increase in the plasma-to-water partial pressure NH3 gradient. Alanine aminotransferase activity was higher in the gills of fish exposed to pH 4 versus control water, suggesting that ammonia may be generated in gill tissue. Gill Rhcg-b and NHE3b messenger RNA levels were significantly elevated in acid-treated relative to control fish, but at the protein level Rhcg-b decreased (30%) and NHE3b increased (2-fold) in response to water of pH 4.0. Using immunofluorescence microscopy, NHE3b and Rhcg-b were found to be colocalized to ionocytes along the interlamellar space of the filament of control fish. After 72 h of acid exposure, Rhcg-b staining almost disappeared from this region, and NHE3b was more prominent along the lamellae. We propose that ammoniagenesis within the gill tissue itself is responsible for the higher rates of branchial ammonia excretion during chronic metabolic acidosis. Unexpectedly, gill Rhcg-b does not appear to be important in gill ammonia transport in low-pH water, but the strong induction of NHE3b suggests that some NH4(+) may be eliminated directly in exchange for Na(+). These findings contrast with previous studies in larval zebrafish

  8. Carnosine inhibits carbonic anhydrase IX-mediated extracellular acidosis and suppresses growth of HeLa tumor xenografts

    Carbonic anhydrase IX (CA IX) is a transmembrane enzyme that is present in many types of solid tumors. Expression of CA IX is driven predominantly by the hypoxia-inducible factor (HIF) pathway and helps to maintain intracellular pH homeostasis under hypoxic conditions, resulting in acidification of the tumor microenvironment. Carnosine (β-alanyl-L-histidine) is an anti-tumorigenic agent that inhibits the proliferation of cancer cells. In this study, we investigated the role of CA IX in carnosine-mediated antitumor activity and whether the underlying mechanism involves transcriptional and translational modulation of HIF-1α and CA IX and/or altered CA IX function. The effect of carnosine was studied using two-dimensional cell monolayers of several cell lines with endogenous CA IX expression as well as Madin Darby canine kidney transfectants, three-dimensional HeLa spheroids, and an in vivo model of HeLa xenografts in nude mice. mRNA and protein expression and protein localization were analyzed by real-time PCR, western blot analysis, and immunofluorescence staining, respectively. Cell viability was measured by a flow cytometric assay. Expression of HIF-1α and CA IX in tumors was assessed by immunohistochemical staining. Real-time measurement of pH was performed using a sensor dish reader. Binding of CA IX to specific antibodies and metabolon partners was investigated by competitive ELISA and proximity ligation assays, respectively. Carnosine increased the expression levels of HIF-1α and HIF targets and increased the extracellular pH, suggesting an inhibitory effect on CA IX-mediated acidosis. Moreover, carnosine significantly inhibited the growth of three-dimensional spheroids and tumor xenografts compared with untreated controls. Competitive ELISA showed that carnosine disrupted binding between CA IX and antibodies specific for its catalytic domain. This finding was supported by reduced formation of the functional metabolon of CA IX and anion exchanger 2 in the

  9. Providing Delay Guarantees in Bluetooth

    Ait Yaiz, Rachid; Heijenk, Geert; Titsworth, F.

    2003-01-01

    Bluetooth polling, also referred to as Bluetooth MAC scheduling or intra-piconet scheduling, is the mechanism that schedules the traffic between the participants in a Bluetooth network. Hence, this mechanism is highly determining with respect to the delay packets experience in a Bluetooth network. I

  10. Diagnostic Delay in Rheumatoid Arthritis

    Mølbaek, Karen; Hørslev-Petersen, Kim; Primdahl, Jette

    2016-01-01

    BACKGROUND: To prevent joint damage among patients with rheumatoid arthritis (RA), there is a need to minimize delays from the onset of symptoms until the initiation of appropriate therapy. The present study explored the factors that have an impact on the time it takes for Danish patients with RA...

  11. Deconstructing delayed posttraumatic stress disorder

    Smid, G.E.

    2011-01-01

    According to the Diagnostic and Statistical Manual of Mental Disorders, delayed posttraumatic stress disorder (PTSD) must be diagnosed in individuals fulfilling criteria for PTSD if the onset of symptoms is at least six months after the trauma. The purpose of this thesis was to establish the prevale

  12. Design flaw could delay collider

    Cho, Adrian

    2007-01-01

    "A magnet for the Large Hadron Collider (LHC) failed during a key test at the European particle physics laboratory CERN last week. Physicists and engineers will have to repair the damaged magnet and retrofit others to correct the underlynig design flaw, which could delay the start-up of the mammouth subterranean machine." (1,5 page)

  13. Local Effects of Delayed Food

    Davison, Michael; Baum, William M.

    2007-01-01

    Five pigeons were trained on a procedure in which seven concurrent variable-interval schedules arranged seven different food-rate ratios in random sequence in each session. Each of these components lasted for 10 response-produced food deliveries, and components were separated by 10-s blackouts. We varied delays to food (signaled by blackout)…

  14. Livermore blasted for project delay

    1999-01-01

    In a 12 page report issued last week, a review committee set up by the University of California has concluded that mismanagement and poor planning are to blame for significant cost overruns and delays in the construction of NIF, the worlds largest laser (1 page).

  15. Early-delayed radiation rhombencephalopathy

    A 37-year-old woman developed an early-delayed rhombencephalopathy 7 weeks after completing a course of radiotherapy to a glomus jugulare tumour. The clinical features, comprising nystagmus, skew strabismus, unilateral facial weakness, dysarthria and ataxia, are compared with four previously reported patients with this syndrome. (author)

  16. Delayed School Entry in Uganda

    Moyi, Peter

    2011-01-01

    Since 1997 Uganda has seen a large increase in school enrolment. Despite this increased enrolment, universal education has remained elusive. Many children enrol in school, but not at the recommended age, and they drop out before completing school. This article focuses on one of these problems--delayed school entry. What household factors are…

  17. 儿童远端肾小管酸中毒1例%1 Case of Children With Distal Renal Tubular Acidosis

    王瑞彬

    2015-01-01

    在儿科临床工作中,如果小儿有烦渴,多饮,多尿,腹泻,乏力,低钾血症,不明原因的代谢性酸中毒,生长发育落后,佝偻病,要考虑到本病,进一步检查血离子,血气,肾功能,尿常规,双肾超声,腕骨 X 线片。注意酸碱度,有无高氯性酸中毒,电解质紊乱,活动性佝偻病,肾结石,肾钙化。%In pediatric clinical work if the child has thirst, polydipsia, polyuria, diarrhea, fatigue, hypokalemia, metabolic acidosis, unexplained, growth retardation, rickets, taking into account the disease, further examination of blood ions, blood gas, kidney function, urine routine, renal ultrasound, Carpale x-ray. Note that the pH is hyperchloremic acidosis, electrolyte disorder, activity of rickets, kidney stones, renal calcification.

  18. The Pathogenesis and Prevention of Ruminal Acidosis in Cattle%牛瘤胃酸中毒发病机制与防治的研究进展

    陈渊; 朱家增; 邓立新; 李小波; 贺丛; 贺秀媛

    2011-01-01

    With the development of intensive cultivation on cattle, the high-concentrated feed has been used more and more widely. It has improved the bovine performance trait and caused some nutrition metabolic diseases, especially ruminal acidosis's occurrence, which has resulted in enormously economic losses. The pathogenesis and prevention of ruminal acidosis are discussed systematically in this article in order to provide theoretical instruction for preventing the occurrence of this disease.%随着牛集约化养殖的发展,高精饲料的使用越来越广泛,这在不断提高牛生产性能的同时也引起了一些营养代谢病,特别是瘤胃酸中毒的发生,给养殖业造成了巨大的经济损失.作者就牛瘤胃酸中毒的发病机制与防治进行了较为系统地论述,以期为临床生产中更有效地预防和控制该病的发生和流行提供一定的理论参考.

  19. Deficiency of the iron-sulfur clusters of mitochondrial reduced nicotinamide-adenine dinucleotide-ubiquinone oxidoreductase (complex I) in an infant with congenital lactic acidosis.

    Moreadith, R W; Batshaw, M L; Ohnishi, T; Kerr, D; Knox, B; Jackson, D; Hruban, R; Olson, J; Reynafarje, B; Lehninger, A L

    1984-09-01

    We report the case of an infant with hypoglycemia, progressive lactic acidosis, an increased serum lactate/pyruvate ratio, and elevated plasma alanine, who had a moderate to profound decrease in the ability of mitochondria from four organs to oxidize pyruvate, malate plus glutamate, citrate, and other NAD+-linked respiratory substrates. The capacity to oxidize the flavin adenine dinucleotide-linked substrate, succinate, was normal. The most pronounced deficiency was in skeletal muscle, the least in kidney mitochondria. Enzymatic assays on isolated mitochondria ruled out defects in complexes II, III, and IV of the respiratory chain. Further studies showed that the defect was localized in the inner membrane mitochondrial NADH-ubiquinone oxidoreductase (complex I). When ferricyanide was used as an artificial electron acceptor, complex I activity was normal, indicating that electrons from NADH could reduce the flavin mononucleotide cofactor. However, electron paramagnetic resonance spectroscopy performed on liver submitochondrial particles showed an almost total loss of the iron-sulfur clusters characteristic of complex I, whereas normal signals were noted for other mitochondrial iron-sulfur clusters. This infant is presented as the first reported case of congenital lactic acidosis caused by a deficiency of the iron-sulfur clusters of complex I of the mitochondrial electron transport chain. PMID:6432847

  20. [Gastric emptying and metabolic acidosis. II. Study, in an experimental model in rats, of gastric retention of a sodium bicarbonate solution].

    Belangero, V M; Collares, E F

    1992-01-01

    The gastric emptying of a 0.25 M sodium bicarbonate solution was studied in rats with metabolic acidosis induced by a previous (6 hours) orogastric infusion of a 0.5 M ammonium chloride solution. Two control groups were used: one previously infused with 0.5 M sodium chloride and the other with water, in the same volume that further solutions. Every animal was fed with 2 ml/100 g of its weight of these solutions. The test meal (bicarbonate solution) was utilized containing 6 mg% red fenol as a marker. The gastric retentions were determined 6 hours after those first meals at 5, 10, 20 and 30 minutes. The results demonstrated that the gastric retentions of the bicarbonate solution were significantly lower in the acidotic group than that one of water group (at 20 minutes) and that one of the sodium chloride (at 10, 20 and 30 minutes). The data here presented suggest that metabolic acidosis accelerates the gastric emptying of a sodium bicarbonate solution. PMID:1339142

  1. Renal Tubular Acidosis

    ... is normal, but too much acid—acidosis—can disturb many bodily functions. Healthy kidneys help maintain acid- ... disseminates research findings through its clearinghouses and education programs to increase knowledge and understanding about health and ...

  2. Relationship of hyperlactatemia and metabolic acidosis%高乳酸血症与代谢性酸中毒的相互关系

    杜微; 刘大为; 石岩; 隆云; 芮曦; 王小亭

    2011-01-01

    目的 观察重症患者的高乳酸血症与代谢性酸中毒的相关性,以提供更为准确的反映组织灌注的指标.方法 回顾了2009年8月至2010年4月,9个月间所有重症医学科(ICU)患者的血气分析结果.入选标准为患者同时抽取的一份动脉血标本同时送检血气分析、血清电解质、血清白蛋白检查,其中血气分析结果中乳酸升高,满足高乳酸血症标准(Lac≥2 mmol/L)的结果.结果 在这一乳酸升高(Lac≥2)的人群中用传统方法判断代酸,代酸发生率33.9%,用Stewart's方法判断代酸,代酸发生率为56.0%.但该组人群血清pH值不具有典型酸血症的特点(7.42±0.07),存活组中乳酸占代酸的百分比为(33.6±17.9)%,死亡组中乳酸占代酸的百分比为(42.1±18.5)%,P=0.008;存活组中SIG占代酸百分比为(28.6±23.5)%,死亡组中SIG占代酸的百分比(44.9±23.0)%,P=0.000.结论 在ICU乳酸升高的人群中,乳酸并不是引起代酸的主要成分,乳酸和SIG共同组成代酸的主要组分,但乳酸占代酸的百分比和SIG占代酸的百分比升高可能提示预后不佳,这两个指标也许能为临床提供更准确的反映组织灌注的信息.%Objective To investigate the acid-base abnormalities of the patients with hyperlactatemia and explore the relationship of hyperlactatemia and metabolic acidosis so as to seek a more precise index of reflecting organ perfusion. Methods From August 2009 to April 2010, all consecutive patients admitted into intensive care unit received an analysis of blood gas. Those individuals with arterial lactate ≥2 mmol/L were selected. Results In the group of hyperlactatemic patients, the occurrence of metabolic acidosis as judged by the traditional method was less than that by the Stewart's method (33.9% vs 56. 0% ). No typical acidemia was found. And all components of metabolic acidosis were calculated. Lactate and SIG (strong ion gap ) contributed a certain percentage to metabolic acidosis in the

  3. Distributed delays stabilize neural feedback systems

    Meyer, Ulrike; Chakrabarty, Saurish; Brandt, Sebastian F; Luksch, Harald; Wessel, Ralf

    2007-01-01

    We consider the effect of distributed delays in neural feedback systems. The avian optic tectum is reciprocally connected with the nucleus isthmi. Extracellular stimulation combined with intracellular recordings reveal a range of signal delays from 4 to 9 ms between isthmotectal elements. This observation together with prior mathematical analysis concerning the influence of a delay distribution on system dynamics raises the question whether a broad delay distribution can impact the dynamics of neural feedback loops. For a system of reciprocally connected model neurons, we found that distributed delays enhance system stability in the following sense. With increased distribution of delays, the system converges faster to a fixed point and converges slower toward a limit cycle. Further, the introduction of distributed delays leads to an increased range of the average delay value for which the system's equilibrium point is stable. The enhancement of stability with increasing delay distribution is caused by the int...

  4. Stabilization of linear continuous time-varying systems with state delays in Hilbert spaces

    Vu Ngoc Phat

    2001-10-01

    Full Text Available This paper studies the stabilization of the infinite-dimensional linear time-varying system with state delays $$dot x = A(tx + A_1(tx(t-h+B(tu,.$$ The operator $A(t$ is assumed to be the generator of a strong evolution operator. In contrast to the previous results, the stabilizability conditions are obtained via solving a Riccati differential equation and do not involve any stability property of the evolution operator. Our conditions are easy to construct and to verify. We provide a step-by-step procedure for finding feedback controllers and state stability conditions for some linear delay control systems with nonlinear perturbations.

  5. Delay of Vehicle Motion in Traffic Dynamics

    Bando, M; Nakanishi, K; Nakayama, A; Bando, Masako; Hasebe, Katsuya; Nakanishi, Ken; Nakayama, Akihiro

    1996-01-01

    We demonstrate that in Optimal Velocity Model (OVM) delay times of vehicles coming from the dynamical equation of motion of OVM almost explain the order of delay times observed in actual traffic flows without introducing explicit delay times. Delay times in various cases are estimated: the case of a leader vehicle and its follower, a queue of vehicles controlled by traffic lights and many-vehicle case of highway traffic flow. The remarkable result is that in most of the situation for which we can make a reasonable definition of a delay time, the obtained delay time is of order 1 second.

  6. Characteristics of a Delayed System with Time-dependent Delay Time

    Kye, Won-Ho; Choi, Muhan; Rim, Sunghwan; Kurdoglyan, M. S.; Kim, Chil-Min; Park, Young-Jai

    2004-01-01

    The characteristics of a time-delayed system with time-dependent delay time is investigated. We demonstrate the nonlinearity characteristics of the time-delayed system are significantly changed depending on the properties of time-dependent delay time and especially that the reconstructed phase trajectory of the system is not collapsed into simple manifold, differently from the delayed system with fixed delay time. We discuss the possibility of a phase space reconstruction and its applications.

  7. Delay-dependent stability criteria for time-delay chaotic systems via time-delay feedback control

    This paper studies delay-dependent stability of time-delay chaotic systems via time-delayed feedback control (DFC). The delay-dependent stability criteria via DFC are derived from the results based on standard feedback control (SFC), the method can be obtained to stabilize the system to an unstable fixed point. A numerical example is discussed to illustrate the advantage of the obtained result

  8. Delay locked loop integrated circuit.

    Brocato, Robert Wesley

    2007-10-01

    This report gives a description of the development of a Delay Locked Loop (DLL) integrated circuit (IC). The DLL was developed and tested as a stand-alone IC test chip to be integrated into a larger application specific integrated circuit (ASIC), the Quadrature Digital Waveform Synthesizer (QDWS). The purpose of the DLL is to provide a digitally programmable delay to enable synchronization between an internal system clock and external peripherals with unknown clock skew. The DLL was designed and fabricated in the IBM 8RF process, a 0.13 {micro}m CMOS process. It was designed to operate with a 300MHz clock and has been tested up to 500MHz.

  9. Assembly delay line pulse generators

    1971-01-01

    Assembly of six of the ten delay line pulse generators that will power the ten kicker magnet modules. One modulator part contains two pulse generators. Capacitors, inductances, and voltage dividers are in the oil tank on the left. Triggered high-pressure spark gap switches are on the platforms on the right. High voltage pulse cables to the kicker magnet emerge under the spark gaps. In the centre background are the assembled master gaps.

  10. Teriparatide Induced Delayed Persistent Hypercalcemia

    Nirosshan Thiruchelvam

    2014-01-01

    Full Text Available Teriparatide, a recombinant PTH, is an anabolic treatment for osteoporosis that increases bone density. Transient hypercalcemia is a reported side effect of teriparatide that is seen few hours following administration of teriparatide and resolves usually within 16 hours of drug administration. Persistent hypercalcemia, although not observed in clinical trials, is rarely reported. The current case describes a rare complication of teriparatide induced delayed persistent hypercalcemia.

  11. Incident Dispatching, Clearance and Delay

    Hall, Randolph

    2000-01-01

    This report models response times and delays for highway incidents, according for spacing between interchanges and the time penalty for changing directions, enabling a response vehicle to reach an incident on the opposite side of the highway. A fundamental question in dispatching incident crews is whether to send the closest vehicle that is currently available or to wait for another to become available that is even closer. Waiting for a closer one is advantageous because service time is effec...

  12. A Delayed Choice Quantum Eraser

    Kim, Yoon-Ho; R. Yu; Kulik, S. P.; Shih, Y. H.; Scully, Marlan O.

    1999-01-01

    This paper reports a "delayed choice quantum eraser" experiment proposed by Scully and Dr\\"{u}hl in 1982. The experimental results demonstrated the possibility of simultaneously observing both particle-like and wave-like behavior of a quantum via quantum entanglement. The which-path or both-path information of a quantum can be erased or marked by its entangled twin even after the registration of the quantum.

  13. Peripartal changes in reticuloruminal pH and temperature in dairy cows differing in the susceptibility to subacute rumen acidosis.

    Humer, E; Ghareeb, K; Harder, H; Mickdam, E; Khol-Parisini, A; Zebeli, Q

    2015-12-01

    The present study aimed to investigate changes in the reticuloruminal pH and temperature dynamics in periparturient dairy cows. Reticuloruminal pH and temperature measurements were conducted from 7 d before until 8 d after parturition using indwelling sensors. Nine Simmental and 4 Brown Swiss dairy cows were fed a close-up total mixed ration (52.5% neutral detergent fiber, 5.68MJ of net energy for lactation per kg of dry matter) with additional 1kg/cow per d concentrate mixture (29.5% neutral detergent fiber and 6.25MJ of net energy for lactation per kg of dry matter), starting from 2 wk before the estimated calving date. Postpartum, all cows had free access to the same close-up diet and were gradually fed increasing amounts of a concentrate-rich total mixed ration for early-lactation cows (32.7% neutral detergent fiber, 7.22MJ of net energy for lactation per kg of dry matter). Data showed depressed reticuloruminal pH early postpartum, but only in the group of cows defined as subacute ruminal acidosis (SARA) susceptible (n=8), which had a higher duration time of pH cows (n=5; 15±6min/d). Also, compared with SARA-tolerant cows (112±91min/d), the SARA-susceptible group showed longer (1,049±75min/d) duration time of pH cows (6.25±0.05), but no differences were observed in the duration of pH cows produced more milk (30.4±1.2kg/d) compared with Brown Swiss cows (27.9±1.3kg/d). Neither total dry matter intake nor milk yield were different between SARA-susceptible and SARA-tolerant groups. However, SARA-tolerant cows consumed greater amounts of the close-up total mixed ration than their SARA-susceptible counterparts, whereas no difference was observed in the intake of the early-lactating total mixed ration between the groups. Reticuloruminal temperature was not affected by breed or SARA susceptibility. Interestingly, the mean reticuloruminal temperature and the time duration of temperature >39.5°C abruptly dropped from d 2 to 1 before calving by 0.35°C and 430min

  14. Delayed recombination and standard rulers

    Measurements of baryonic acoustic oscillations (BAOs) in galaxy surveys have been recognized as a powerful tool for constraining dark energy. However, this method relies on the knowledge of the size of the acoustic horizon at recombination derived from cosmic microwave background (CMB) anisotropy measurements. This estimate is typically derived assuming a standard recombination scheme; additional radiation sources can delay recombination altering the cosmic ionization history and the cosmological inferences drawn from CMB and BAO data. In this paper we quantify the effect of delayed recombination on the determination of dark energy parameters from future BAO surveys such as the Baryon Oscillation Spectroscopic Survey and the Wide-Field Multi-Object Spectrograph. We find the impact to be small but still not negligible. In particular, if recombination is nonstandard (to a level still allowed by CMB data), but this is ignored, future surveys may incorrectly suggest the presence of a redshift-dependent dark energy component. On the other hand, in the case of delayed recombination, adding to the analysis one extra parameter describing deviations from standard recombination does not significantly degrade the error bars on dark energy parameters and yields unbiased estimates. This is due to the CMB-BAO complementarity.

  15. A quantum delayed choice experiment

    Peruzzo, Alberto; Brunner, Nicolas; Popescu, Sandu; O'Brien, Jeremy L

    2012-01-01

    Quantum systems exhibit particle-like or wave-like behaviour depending on the experimental apparatus they are confronted by. This wave-particle duality is at the heart of quantum mechanics, and is fully captured in Wheeler's famous delayed choice gedanken experiment. In this variant of the double slit experiment, the observer chooses to test either the particle or wave nature of a photon after it has passed through the slits. Here we report on a quantum delayed choice experiment, based on a quantum controlled beam-splitter, in which both particle and wave behaviours can be investigated simultaneously. The genuinely quantum nature of the photon's behaviour is tested via a Bell inequality, which here replaces the delayed choice of the observer. We observe strong Bell inequality violations, thus showing that no model in which the photon knows in advance what type of experiment it will be confronted by, hence behaving either as a particle or as wave, can account for the experimental data.

  16. On Hamlet's Delay in the Revenge

    刘莎

    2009-01-01

    Hamlet is a representative tragedy written by Shakespeare. Question on Hemlet's delay has been drawing the interest of many literature critics. It is still under discussion today. This thesis focuses on analyzing the reasons for Hamlet's delay in the revenge.

  17. Delaying or Preventing Type 2 Diabetes

    ... Care Diabetes Statistics Delaying or Preventing Type 2 Diabetes What is type 2 diabetes? Type 2 diabetes, formerly called adult-onset diabetes, ... for some, taking aspirin daily. Can type 2 diabetes be delayed or prevented? Yes. The results of ...

  18. Robustness of unstable attractors in arbitrarily sized pulse-coupled networks with delay

    We consider arbitrarily large networks of pulse-coupled oscillators with non-zero delay where the coupling is given by the Mirollo–Strogatz function. We prove that such systems have unstable attractors (saddle periodic orbits whose stable set has non-empty interior) in an open parameter region for three or more oscillators. The evolution operator of the system can be discontinuous and we propose an improved model with continuous evolution operator

  19. A Developmental Study on Delay of Gratification

    小林, 小夜子; 光富, 隆

    2009-01-01

    Two studies were conducted to investigate development of delay of gratification. In Study 1, the personal delay of gratification test, social delay of gratification inventory and personality inventory were administered to kindergarteners aged 3 to 6 years. The personal delay of gratification test included three reward pairs and subjects were instructed to choose between a less valuable reward which was immediately available and a more valuable reward which was available tomorrow. In the perso...

  20. Delayed signatures of underground nuclear explosions

    Carrigan, Charles R.; Sun, Yunwei; Hunter, Steven L.; Ruddle, David G.; Wagoner, Jeffrey L.; Myers, Katherine B. L.; Emer, Dudley F.; Drellack, Sigmund L.; Chipman, Veraun D.

    2016-01-01

    Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a former UNE site. We observe the character of signals at the surface due to the migration of gases from the post-detonation chimney under realistic transport conditions. Background radon signals are found to be highly responsive to cavity pressurization suggesting that large local radon anomalies may be an indicator of a clandestine UNE. Computer simulations, using transport properties obtained from the experiment, track radioxenon isotopes in the chimney and their migration to the surface. They show that the chimney surrounded by a fractured containment regime behaves as a leaky chemical reactor regarding its effect on isotopic evolution introducing a dependence on nuclear yield not previously considered. This evolutionary model for radioxenon isotopes is validated by atmospheric observations of radioxenon from a 2013 UNE in the Democratic People’s Republic of Korea (DPRK). Our model produces results similar to isotopic observations with nuclear yields being comparable to seismic estimates. PMID:26979288

  1. Delayed signatures of underground nuclear explosions

    Carrigan, Charles R.; Sun, Yunwei; Hunter, Steven L.; Ruddle, David G.; Wagoner, Jeffrey L.; Myers, Katherine B. L.; Emer, Dudley F.; Drellack, Sigmund L.; Chipman, Veraun D.

    2016-03-01

    Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a former UNE site. We observe the character of signals at the surface due to the migration of gases from the post-detonation chimney under realistic transport conditions. Background radon signals are found to be highly responsive to cavity pressurization suggesting that large local radon anomalies may be an indicator of a clandestine UNE. Computer simulations, using transport properties obtained from the experiment, track radioxenon isotopes in the chimney and their migration to the surface. They show that the chimney surrounded by a fractured containment regime behaves as a leaky chemical reactor regarding its effect on isotopic evolution introducing a dependence on nuclear yield not previously considered. This evolutionary model for radioxenon isotopes is validated by atmospheric observations of radioxenon from a 2013 UNE in the Democratic People’s Republic of Korea (DPRK). Our model produces results similar to isotopic observations with nuclear yields being comparable to seismic estimates.

  2. Dynamic Cournot Duopoly Game with Delay

    A. A. Elsadany

    2014-01-01

    Full Text Available The delay Cournot duopoly game is studied. Dynamical behaviors of the game are studied. Equilibrium points and their stability are studied. The results show that the delayed system has the same Nash equilibrium point and the delay can increase the local stability region.

  3. Nonautonomous Lotka-Volterra Systems with Delays

    Teng, Zhidong

    2002-03-01

    The paper studies the general nonautonomous Lotka-Volterra multispecies systems with finite delays. The ultimate boundedness, permanence, global attractivity, and existence and uniqueness of strictly positive solutions, positive periodic solutions, and almost periodic solutions are obtained. These results are basically an extension of the known results for nonautonomous Lotka-Volterra multispecies systems without delay to systems with delay.

  4. Modelling delay propagation within an airport network

    Pyrgiotis, N.; Malone, K.M.; Odoni, A.

    2013-01-01

    We describe an analytical queuing and network decomposition model developed to study the complex phenomenon of the propagation of delays within a large network of major airports. The Approximate Network Delays (AND) model computes the delays due to local congestion at individual airports and capture

  5. Modeling the evolution of galactic magnetic fields

    An analytic model for evolution of galactic magnetic fields in hierarchical galaxy formation frameworks is introduced. Its major innovative components include explicit and detailed treatment of the physics of merger events, mass gains and losses, gravitational energy sources and delays associated with formation of large-scale magnetic fields. This paper describes the model, its implementation, and core results obtained by its means

  6. Travelling waves in arrays of delay-coupled phase oscillators

    Laing, Carlo R.

    2016-09-01

    We consider the effects of several forms of delays on the existence and stability of travelling waves in non-locally coupled networks of Kuramoto-type phase oscillators and theta neurons. By passing to the continuum limit and using the Ott/Antonsen ansatz, we derive evolution equations for a spatially dependent order parameter. For phase oscillator networks, the travelling waves take the form of uniformly twisted waves, and these can often be characterised analytically. For networks of theta neurons, the waves are studied numerically.

  7. BOLD delay times using group delay in sickle cell disease

    Coloigner, Julie; Vu, Chau; Bush, Adam; Borzage, Matt; Rajagopalan, Vidya; Lepore, Natasha; Wood, John

    2016-03-01

    Sickle cell disease (SCD) is an inherited blood disorder that effects red blood cells, which can lead to vasoocclusion, ischemia and infarct. This disease often results in neurological damage and strokes, leading to morbidity and mortality. Functional Magnetic Resonance Imaging (fMRI) is a non-invasive technique for measuring and mapping the brain activity. Blood Oxygenation Level-Dependent (BOLD) signals contain also information about the neurovascular coupling, vascular reactivity, oxygenation and blood propagation. Temporal relationship between BOLD fluctuations in different parts of the brain provides also a mean to investigate the blood delay information. We used the induced desaturation as a label to profile transit times through different brain areas, reflecting oxygen utilization of tissue. In this study, we aimed to compare blood flow propagation delay times between these patients and healthy subjects in areas vascularized by anterior, middle and posterior cerebral arteries. In a group comparison analysis with control subjects, BOLD changes in these areas were found to be almost simultaneous and shorter in the SCD patients, because of their increased brain blood flow. Secondly, the analysis of a patient with a stenosis on the anterior cerebral artery indicated that signal of the area vascularized by this artery lagged the MCA signal. These findings suggest that sickle cell disease causes blood propagation modifications, and that these changes could be used as a biomarker of vascular damage.

  8. Comparison of conventional and diffusion-weighted MRI and proton MR spectroscopy in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like events

    Abe, K.; Hikita, T.; Sakoda, S. [Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, 565-0871, Osaka (Japan); Yoshimura, H.; Tanaka, H.; Fujita, N. [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, 565-0871, Osaka (Japan)

    2004-02-01

    The mechanism of neurological disturbances in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is controversial. We studied 12 patients with MELAS using conventional and diffusion weighted MRI (DWI) and MR spectroscopy (MRS), to look at the physiopathology of the stroke-like events. Although conventional MRI showed lesions in all patients, DWI was more sensitive. One patient did not show high signal on DWI 48 h after a from stroke-like episode, but MRS demonstrated a lactate peak in left occipital lobe; 2 weeks after the attack, high signal was demonstrated on the right frontal lobe where MRS had shown a lactate peak. Our findings suggest a possible predictive ability of {sup 1}H-MRS, in showing early MELAS lesions and supports the hypothesis that mitochondrial metabolic dysfunction may precedes abnormalities on DWI. (orig.)

  9. Predisposition to metabolic acidosis induced by topiramate Predisposição a acidose metabólica induzida por topiramato

    MARIA AUGUSTA MONTENEGRO

    2000-12-01

    Full Text Available RATIONALE: Metabolic acidosis induced by topiramate is a well documented but infrequent adverse event. The objective was to demonstrate the lowering of carbon dioxide serum levels, which is usually asymptomatic but may facilitate the occurrence of metabolic acidosis in patients using topiramate. METHODS: We evaluated, prospectively, the carbon dioxide serum levels of 18 patients seen at the epilepsy clinic of our university hospital, before and 3 months after introducing topiramate. RESULTS: Five patients were female and 13 were male, age ranging from 2 to 16 years old (mean=9.3. Carbon dioxide mean serum levels were 25 and 21.2 mmol/L (normal = 22 to 30, before and 3 months after introducing topiramate, respectively. Dose ranged from 2.08 to 11.76 mg/kg/day (mean=6.7mg/kg/day. Adverse events were anorexia, nausea and somnolence. CONCLUSION: We conclude that the lowering of carbon dioxide serum levels induced by topiramate is mostly asymptomatic, but may facilitate the occurrence of metabolic acidosis. Since patients in use of topiramate have refractory epilepsy, they may need epilepsy surgery, and must be carefully monitored for the risk of metabolic acidosis during surgery.INTRODUÇÃO: Acidose metabólica induzida por topiramato é evento adverso pouco frequente, mas bem documentado. Nosso objetivo foi demonstrar a diminuição dos níveis de dióxido de carbono, muitas vezes assintomática, mas que pode predispor ao aparecimento de acidose metabólica. MATERIAL E MÉTODO: Avaliamos prospectivamente os níveis de dióxido de carbono de 18 pacientes acompanhados no ambulatório de epilepsia infantil da UNICAMP, antes e 3 meses após o início do uso de topiramato. RESULTADOS: Foram avaliados 18 pacientes com idade entre 2 e 16 anos (média = 9,3 anos. Cinco pacientes eram do sexo feminino e 13, do sexo masculino. Os níveis médios de dióxido de carbono antes e após o uso de topiramato foram 25 e 21,2 mmol/L (normal = 22 a 30

  10. Control of Fractal Erosion of Safe Basins in a Holmes-Duffing System via Delayed Position Feedback

    SHANG Hui-Lin

    2011-01-01

    A linear delayed position feedback control is applied to control the erosion of safe basins in a Holmes-Duffing system. The conditions of fractal erosion of the safe basin of the controlled system on the basis that the range of time delay leading to good control is obtained by the Melnikov method. It is found that the increasing time delay can reduce the basin erosion under a weak and positive feedback gain. Then the evolutions of safe basins with time delay are presented in detail by the fourth Runge-Kutta and Monte-Carlo methods, which shows that the safe basin of the controlled Holmes-Duffing system can be expanded, and its fractal can be reduced by the increasing time delay. These results suggest that delayed position feedbacks can be used as a good approach to control the erosion of safe basins.

  11. Activation of P-glycoprotein (Pgp)-mediated drug efflux by extracellular acidosis: in vivo imaging with 68Ga-labelled PET tracer

    In vitro it has been shown that the functional activity of P-glycoprotein (Pgp), an important drug transporter responsible for multidrug resistance, can be strongly increased by extracellular acidosis. Here mitogen-activated protein kinases (MAPK) (p38, ERK1/2) seem to play an important role for signal transduction. However, it is unclear whether these effects are also relevant in vivo. With the newly developed PET tracer Schiff base-based 68Ga-MFL6.MZ the functional Pgp activity was visualized under acidic conditions and during inhibition of MAPKs non-invasively by means of microPET in rat tumours. Tumours were acidified either by inspiratory hypoxia (8% O2) or by injection of lactic acid. Inhibitors of the MAPK were injected intratumourally. With increasing tumour volume the tumour pH changed from 7.0 to 6.7 and simultaneously the Pgp activity increased almost linearly. When the tumour was acidified by direct lactic acid injection the PET tracer uptake was reduced by 20% indicating a higher transport rate out of the cells. Changing the inspiratory O2 fraction to 8% dynamically led to a reduction of extracellular pH and in parallel to a decrease of tracer concentration. While inhibition of the p38 pathway reduced the Pgp transport rate, inhibition of ERK1/2 had practically no impact. An acidic extracellular environment significantly stimulates the Pgp activity. The p38 MAPK pathway plays an important role for Pgp regulation in vivo, whereas ERK1/2 is of minor importance. From these results new strategies for overcoming multidrug resistance (e.g. reducing tumour acidosis, inhibition of p38) may be developed. (orig.)

  12. Activation of P-glycoprotein (Pgp)-mediated drug efflux by extracellular acidosis: in vivo imaging with {sup 68}Ga-labelled PET tracer

    Thews, Oliver; Dillenburg, Wolfgang [University Medicine Mainz, Institute of Physiology and Pathophysiology, Mainz (Germany); Fellner, Marco; Roesch, Frank [University of Mainz, Institute of Nuclear Chemistry, Mainz (Germany); Buchholz, Hans-Georg; Bausbacher, Nicole; Schreckenberger, Mathias [University Medicine Mainz, Department of Nuclear Medicine, Mainz (Germany)

    2010-10-15

    In vitro it has been shown that the functional activity of P-glycoprotein (Pgp), an important drug transporter responsible for multidrug resistance, can be strongly increased by extracellular acidosis. Here mitogen-activated protein kinases (MAPK) (p38, ERK1/2) seem to play an important role for signal transduction. However, it is unclear whether these effects are also relevant in vivo. With the newly developed PET tracer Schiff base-based {sup 68}Ga-MFL6.MZ the functional Pgp activity was visualized under acidic conditions and during inhibition of MAPKs non-invasively by means of microPET in rat tumours. Tumours were acidified either by inspiratory hypoxia (8% O{sub 2}) or by injection of lactic acid. Inhibitors of the MAPK were injected intratumourally. With increasing tumour volume the tumour pH changed from 7.0 to 6.7 and simultaneously the Pgp activity increased almost linearly. When the tumour was acidified by direct lactic acid injection the PET tracer uptake was reduced by 20% indicating a higher transport rate out of the cells. Changing the inspiratory O{sub 2} fraction to 8% dynamically led to a reduction of extracellular pH and in parallel to a decrease of tracer concentration. While inhibition of the p38 pathway reduced the Pgp transport rate, inhibition of ERK1/2 had practically no impact. An acidic extracellular environment significantly stimulates the Pgp activity. The p38 MAPK pathway plays an important role for Pgp regulation in vivo, whereas ERK1/2 is of minor importance. From these results new strategies for overcoming multidrug resistance (e.g. reducing tumour acidosis, inhibition of p38) may be developed. (orig.)

  13. Glucocorticoid activity and metabolism with NaCl-induced low-grade metabolic acidosis and oral alkalization: results of two randomized controlled trials.

    Buehlmeier, Judith; Remer, Thomas; Frings-Meuthen, Petra; Maser-Gluth, Christiane; Heer, Martina

    2016-04-01

    Low-grade metabolic acidosis (LGMA), as induced by high dietary acid load or sodium chloride (NaCl) intake, has been shown to increase bone and protein catabolism. Underlying mechanisms are not fully understood, but from clinical metabolic acidosis interactions of acid-base balance with glucocorticoid (GC) metabolism are known. We aimed to investigate GC activity/metabolism under alkaline supplementation and NaCl-induced LGMA. Eight young, healthy, normal-weight men participated in two crossover designed interventional studies. In Study A, two 10-day high NaCl diet (32 g/d) periods were conducted, one supplemented with 90 mmol KHCO3/day. In Study B, participants received a high and a low NaCl diet (31 vs. 3 g/day), each for 14 days. During low NaCl, the diet was moderately acidified by replacement of a bicarbonate-rich mineral water (consumed during high NaCl) with a non-alkalizing drinking water. In repeatedly collected 24-h urine samples, potentially bioactive-free GCs (urinary-free cortisol + free cortisone) were analyzed, as well as tetrahydrocortisol (THF), 5α-THF, and tetrahydrocortisone (THE). With supplementation of 90 mmol KHCO3, the marker of total adrenal GC secretion (THF + 5α-THF + THE) dropped (p = 0.047) and potentially bioactive-free GCs were reduced (p = 0.003). In Study B, however, GC secretion and potentially bioactive-free GCs did not exhibit the expected fall with NaCl-reduction as net acid excretion was raised by 30 mEq/d. Diet-induced acidification/alkalization affects GC activity and metabolism, which in case of long-term ingestion of habitually acidifying western diets may constitute an independent risk factor for bone degradation and cardiometabolic diseases. PMID:26349936

  14. Time-delayed feedback in neurosystems

    Schoell, E.; Hiller, G; Hoevel, P.; Dahlem, M. A.

    2008-01-01

    The influence of time delay in systems of two coupled excitable neurons is studied in the framework of the FitzHugh-Nagumo model. Time-delay can occur in the coupling between neurons or in a self-feedback loop. The stochastic synchronization of instantaneously coupled neurons under the influence of white noise can be deliberately controlled by local time-delayed feedback. By appropriate choice of the delay time synchronization can be either enhanced or suppressed. In delay-coupled neurons, an...

  15. Delay Variation Model with Two Service Queues

    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.

  16. Stellar evolution

    Meadows, A J

    2013-01-01

    Stellar Evolution, Second Edition covers the significant advances in the understanding of birth, life, and death of stars.This book is divided into nine chapters and begins with a description of the characteristics of stars according to their brightness, distance, size, mass, age, and chemical composition. The next chapters deal with the families, structure, and birth of stars. These topics are followed by discussions of the chemical composition and the evolution of main-sequence stars. A chapter focuses on the unique features of the sun as a star, including its evolution, magnetic fields, act

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

    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.

  18. Delay test generation for synchronous sequential circuits

    Devadas, Srinivas

    1989-05-01

    We address the problem of generating tests for delay faults in non-scan synchronous sequential circuits. Delay test generation for sequential circuits is a considerably more difficult problem than delay testing of combinational circuits and has received much less attention. In this paper, we present a method for generating test sequences to detect delay faults in sequential circuits using the stuck-at fault sequential test generator STALLION. The method is complete in that it will generate a delay test sequence for a targeted fault given sufficient CPU time, if such a sequence exists. We term faults for which no delay test sequence exists, under out test methodology, sequentially delay redundant. We describe means of eliminating sequential delay redundancies in logic circuits. We present a partial-scan methodology for enhancing the testability of difficult-to-test of untestable sequential circuits, wherein a small number of flip-flops are selected and made controllable/observable. The selection process guarantees the elimination of all sequential delay redundancies. We show that an intimate relationship exists between state assignment and delay testability of a sequential machine. We describe a state assignment algorithm for the synthesis of sequential machines with maximal delay fault testability. Preliminary experimental results using the test generation, partial-scan and synthesis algorithm are presented.

  19. Precise delay measurement through combinatorial logic

    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.

  20. Delay in the diagnosis of cancer

    Hansen, Rikke Pilegaard

    with all cancer diagnoses in a common data pool. The chapter raises a series of questions from which the aims of the thesis are formulated. The aims of the PhD thesis were: 1) To measure the length of patient, doctor, system and total delay for all cancers in a population-based cohort study and to examine...... to which extent delay differs by cancer type (Article 1). 2) To analyze whether specific socioeconomic and psychosocial patient characteristics predict long delay in cancer diagnosis (Articles 2 and 3). 3) To analyze whether specific GP and practice characteristics predict long delay in cancer diagnosis...... components, long delays were experienced by the 4th quartile of patients. We found much variation in delay by cancer type. In Article 2 we report that male patients had a higher likelihood of long doctor delays than women when gender-specific cancers were excluded, but apart from this, gender did not predict...

  1. Programmable Electronic Delay Device for Detonator

    A. Sudheer Babu

    2013-05-01

    Full Text Available Delay devices are used to perform various roles like aiding in sequential release of payload, providing safety in flight/ trajectory, enabling self-destruction of ammunitions, allowing blast of the warhead after penetration in runway/bunker, etc. The delay time is introduced to cause a series of detonation events from the explosive charge, in order to achieve desired efficiency. Inspite of many improvements performed along the years, in search of precise delay compositions, it is noticed that the obtained accuracy in chemical delay compositions is of ±4%.The present work using microcontroller gives possible accuracy of upto ±1%.This paper discusses about programmable electronic delay device, timing accuracy of electronic delay device and its merits over chemical delay devices.Defence Science Journal, 2013, 63(3, pp.305-307, DOI:http://dx.doi.org/10.14429/dsj.63.2880

  2. Optimal Kalman Filtering for a Class of State Delay Systems with Randomly Multiple Sensor Delays

    Dongyan Chen; Long Xu

    2014-01-01

    The optimal Kalman filtering problem is investigated for a class of discrete state delay stochastic systems with randomly multiple sensor delays. The phenomenon of measurement delay occurs in a random way and the delay rate for each sensor is described by a Bernoulli distributed random variable with known conditional probability. Based on the innovative analysis approach and recursive projection formula, a new linear optimal filter is designed such that, for the state delay and randomly multi...

  3. Time-delay feedback control in a delayed dynamical chaos system and its applications

    Ye, Zhi-Yong; Yang, Guang; Deng, Cun-Bing

    2011-01-01

    The feedback control of a delayed dynamical system, which also includes various chaotic systems with time delays, is investigated. On the basis of stability analysis of a nonautonomous system with delays, some simple yet less conservative criteria are obtained for feedback control in a delayed dynamical system. Finally, the theoretical result is applied to a typical class of chaotic Lorenz system and Chua circuit with delays. Numerical simulations are also given to verify the theoretical results.

  4. New Delay-dependent Stability Criteria for Linear Systems with Time-varying Delay

    Weiwei Zhang

    2013-01-01

    Full Text Available This paper is concerned with the problem of asymptotic stability for linear systems with time-varying delays. With the introduction of delay-partition approach, some new delay-dependent stability criteria are established and formulated in the form of linear matrix inequalities. Both constant time delays and time-varying delays have been taken into account. Numerical examples are given to demonstrate the effectiveness and less conservativeness of the proposed methods.

  5. GENERAL: Synchronization of time-delay chaotic systems on small-world networks with delayed coupling

    Qi, Wei; Wang, Ying-Hai

    2009-04-01

    By using the well-known Ikeda model as the node dynamics, this paper studies synchronization of time-delay systems on small-world networks where the connections between units involve time delays. It shows that, in contrast with the undelayed case, networks with delays can actually synchronize more easily. Specifically, for randomly distributed delays, time-delayed mutual coupling suppresses the chaotic behaviour by stabilizing a fixed point that is unstable for the uncoupled dynamical system.

  6. New Delay-dependent Stability Criteria for Linear Systems with Time-varying Delay

    Weiwei Zhang; Chao Ge; Hong Wang

    2013-01-01

    This paper is concerned with the problem of asymptotic stability for linear systems with time-varying delays. With the introduction of delay-partition approach, some new delay-dependent stability criteria are established and formulated in the form of linear matrix inequalities. Both constant time delays and time-varying delays have been taken into account. Numerical examples are given to demonstrate the effectiveness and less conservativeness of the proposed methods.

  7. Schumpeter's Evolution

    Andersen, Esben Sloth

    This draft of a book on Schumpeter is distributed for commenting. It is a stylised intellectual biography that focus on the emergence and extension of the Schumpeterian vision and analysis of economic and social evolution. The draft provides novel interpretations of Schumpeter's six major books. He...... reworking of his basic theory of economic evolution in Development from 1934, and this reworking was continued in Cycles from 1939. Here Schumpeter also tried to handle the statistical and historical evidence on the waveform evolution of the capitalist economy. Capitalism from 1942 modified the model of...... economic evolution and added evolutionary contributions to other social sciences. History, which was published by his widow, was based on his evolutionary theory of the history of economic analysis. This sequential analysis of Schumpeter's six books demonstrates the progress he within his research...

  8. Delayed recombination and cosmic parameters

    Current cosmological constraints from cosmic microwave background anisotropies are typically derived assuming a standard recombination scheme, however additional resonance and ionizing radiation sources can delay recombination, altering the cosmic ionization history and the cosmological inferences drawn from the cosmic microwave background data. We show that for recent observations of the cosmic microwave background anisotropy, from the Wilkinson microwave anisotropy probe satellite mission (WMAP) 5-year survey and from the arcminute cosmology bolometer array receiver experiment, additional resonance radiation is nearly degenerate with variations in the spectral index, ns, and has a marked effect on uncertainties in constraints on the Hubble constant, age of the universe, curvature and the upper bound on the neutrino mass. When a modified recombination scheme is considered, the redshift of recombination is constrained to z*=1078±11, with uncertainties in the measurement weaker by 1 order of magnitude than those obtained under the assumption of standard recombination while constraints on the shift parameter are shifted by 1σ to R=1.734±0.028. From the WMAP5 data we obtain the following constraints on the resonance and ionization sources parameters: εαi<0.058 at 95% c.l.. Although delayed recombination limits the precision of parameter estimation from the WMAP satellite, we demonstrate that this should not be the case for future, smaller angular scales measurements, such as those by the Planck satellite mission.

  9. A stochastic delay model for pricing debt and equity: Numerical techniques and applications

    Tambue, Antoine; Kemajou Brown, Elisabeth; Mohammed, Salah

    2015-01-01

    Delayed nonlinear models for pricing corporate liabilities and European options were recently developed. Using self-financed strategy and duplication we were able to derive a Random Partial Differential Equation (RPDE) whose solutions describe the evolution of debt and equity values of a corporate in the last delay period interval in the accompanied paper (Kemajou et al., 2012) [14]. In this paper, we provide robust numerical techniques to solve the delayed nonlinear model for the corporate value, along with the corresponding RPDEs modeling the debt and equity values of the corporate. Using financial data from some firms, we forecast and compare numerical solutions from both the nonlinear delayed model and classical Merton model with the real corporate data. From this comparison, it comes up that in corporate finance the past dependence of the firm value process may be an important feature and therefore should not be ignored.

  10. Fractal Erosion of the Safe Basin in a Helmholtz Oscillator and Its Control by Linear Delayed Velocity Feedback

    SHANG Hui-Lin; WEN Yong-Peng

    2011-01-01

    Fractal erosion of the safe basin in a Helmholtz oscillator system is studied. A linear delayed velocity feedback is employed to suppress the fractal erosion. The necessary basin erosion condition of the delayed feedback controlled system is obtained. The evolution of the boundary and area of the safe basin over time delay is also presented. It follows that the delayed velocity feedback can be used as an effective strategy to control fractal erosion of a safe basin.%Fractal erosion of the safe basin in a Helmholtz oscillator system is studied.A linear delayed velocity feedback is employed to suppress the fractal erosion.The necessary basin erosion condition of the delayed feedback controlled system is obtained.The evolution of the boundary and area of the safe basin over time delay is also presented.It follows that the delayed velocity feedback can be used as an effective strategy to control fractal erosion of a safe basin.Since the safe basin was induced to explain the integrity of dynamical systems,studies on safe basins have attracted much attention.[1-6] Leigh and Armin calculated the survival probability of a ferry in random seas by estimating the erosion of the safe basin during the ship rolling motion by using Monte Carlo simulations.[1] Lenci and Rega induced the erosion of a safe basin to explain pull-in phenomenon in micro-electro mechanical systems.[2

  11. Conversion of linear time-invariant time-delay feedback systems into delay-differential equations with commensurate delays

    Yamazaki, Tatsuya; Hagiwara, Tomomichi

    2014-08-01

    A new stability analysis method of time-delay systems (TDSs) called the monodromy operator approach has been studied under the assumption that a TDS is represented as a time-delay feedback system consisting of a finite-dimensional linear time-invariant (LTI) system and a pure delay. For applying this approach to TDSs described by delay-differential equations (DDEs), the problem of converting DDEs into representation as time-delay feedback systems has been studied. With regard to such a problem, it was shown that, under discontinuous initial functions, it is natural to define the solutions of DDEs in two different ways, and the above conversion problem was solved for each of these two definitions. More precisely, the solution of a DDE was represented as either the state of the finite-dimensional part of a time-delay feedback system or a part of the output of another time-delay feedback system, depending on which definition of the DDE solution one is talking about. Motivated by the importance in establishing a thorough relationship between time-delay feedback systems and DDEs, this paper discusses the opposite problem of converting time-delay feedback systems into representation as DDEs, including the discussions about the conversion of the initial conditions. We show that the state of (the finite-dimensional part of) a time-delay feedback system can be represented as the solution of a DDE in the sense of one of the two definitions, while its 'essential' output can be represented as that of another DDE in the sense of the other type of definition. Rigorously speaking, however, it is also shown that the latter representation is possible regardless of the initial conditions, while some initial condition could prevent the conversion into the former representation. This study hence establishes that the representation of TDSs as time-delay feedback systems possesses higher ability than that with DDEs, as description methods for LTI TDSs with commensurate delays.

  12. Variable-delay feedback control of unstable steady states in retarded time-delayed systems

    Gjurchinovski, Aleksandar; 10.1103/PhysRevE.81.016209

    2010-01-01

    We study the stability of unstable steady states in scalar retarded time-delayed systems subjected to a variable-delay feedback control. The important aspect of such a control problem is that time-delayed systems are already infinite-dimensional before the delayed feedback control is turned on. When the frequency of the modulation is large compared to the system's dynamics, the analytic approach consists of relating the stability properties of the resulting variable-delay system with those of an analogous distributed delay system. Otherwise, the stability domains are obtained by a numerical integration of the linearized variable-delay system. The analysis shows that the control domains are significantly larger than those in the usual time-delayed feedback control, and that the complexity of the domain structure depends on the form and the frequency of the delay modulation.

  13. Rates and Delay Times of Type Ia Supernovae

    Ruiter, Ashley J; Fryer, Chris L

    2009-01-01

    We analyze the evolution of binary stars to calculate synthetic rates and delay times of the most promising Type Ia Supernovae progenitors. We present and discuss evolutionary scenarios in which a white dwarf reaches the Chandrasekhar-mass and potentially explodes in a Type Ia supernova. We consider: Double Degenerate (DDS), Single Degenerate (SDS), and AM Canum Venaticorum scenarios. The results are presented for two different star formation histories; burst (elliptical-like galaxies) and continuous (spiral-like galaxies). It is found that delay times for the DDS in our standard model (with common envelope efficiency alpha = 1) follow a power-law distribution. For the SDS we note a wide range of delay times, while AM CVn progenitors produce a short burst of SNe Ia at early times. We point out that only the rates for two merging carbon-oxygen white dwarfs, the only systems found in the DDS, are consistent with the observed rates for typical Milky Way-like spirals. We also note that DDS progenitors are the dom...

  14. Fuzzy delay model based fault simulator for crosstalk delay fault test generation in asynchronous sequential circuits

    S Jayanthy; M C Bhuvaneswari

    2015-02-01

    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. The fault simulator based on fuzzy delay detects unstable states, oscillations and non-confluence of settling states in asynchronous sequential circuits. The fuzzy delay model based fault simulator is used to validate the test patterns produced by Elitist Non-dominated sorting Genetic Algorithm (ENGA) based test generator, for detecting crosstalk delay faults in asynchronous sequential circuits. The multi-objective genetic algorithm, ENGA targets two objectives of maximizing fault coverage and minimizing number of transitions. Experimental results are tabulated for SIS benchmark circuits for three gate delay models, namely unit delay model, rise/fall delay model and fuzzy delay model. Experimental results indicate that test validation using fuzzy delay model is more accurate than unit delay model and rise/fall delay model.

  15. Stability of Impulsive Differential Equation with any Time Delay

    Sanjay K. Srivastava

    2013-03-01

    Full Text Available In this paper, the stability of general impulsive retarded functional differential equations with any time delay has been considered. Many evolution processes are characterized by the fact that at certain moments of time they experience a change of state abruptly. Consequently, it is natural to assume that these perturbations act instantaneously, that is, in the form of impulses. Impulsive differential equations, that is, differential equations involving impulse effects, are a natural description of observed evolution phenomena of several real world problems. Impulsive control which based on impulsive differential equations has attracted the interest of many researchers recently. The method of Lyapunov functions and Razumikhin technique have been widely applied to stability analysis of various delay differential equation. When Lyapunov functions are used, it becomes necessary to choose an appropriate minimal class of functionals relative to which the derivative of the Lyapunov function is estimated. This approach is known as the Lyapunov–Razumikhin technique. When Lyapunov functionals are used the corresponding derivative can be estimated without demanding minimal classes of functional. By using Lyapunov functions and analysis technique along with Razumikhin technique, some results for the uniform stability of such impulsive differential equations have been derived. The obtained results extend and generalize some results existing in the literature.

  16. Noise-and delay-induced phase transitions of the dimer–monomer surface reaction model

    Highlights: ► We study the dimer–monomer surface reaction model. ► We show that noise induces first-order irreversible phase transition (IPT). ► Combination of noise and time-delayed feedback induce first- and second-order IPT. ► First- and second-order IPT is viewed as noise-and delay-induced phase transitions. - Abstract: The effects of noise and time-delayed feedback in the dimer–monomer (DM) surface reaction model are investigated. Applying small delay approximation, we construct a stochastic delayed differential equation and its Fokker–Planck equation to describe the state evolution of the DM reaction model. We show that the noise can only induce first-order irreversible phase transition (IPT) characteristic of the DM model, however the combination of the noise and time-delayed feedback can simultaneously induce first- and second-order IPT characteristics of the DM model. Therefore, it is shown that the well-known first- and second-order IPT characteristics of the DM model may be viewed as noise-and delay-induced phase transitions.

  17. Delayed neutron emission probability measurements

    Some neutrons are emitted from fission fragments several seconds to several minutes after fission occurs. These delayed neutrons play a key role for the conduct and in safety aspects of nuclear reactors [1]. But the probabilities to emit such neutrons (Pn) are not well known. A summary of different database and compilation of Pn values is presented to show these discrepancies and uncertainties. Experiments are carried out at the Lohengrin mass spectrometer (at Inst. Laue Langevin in Grenoble) and at the ISOLDE facility (CERN) in order to measure some Pn values. Two different techniques are used: either by using gamma-rays detection or neutron emission detection. These two techniques and some preliminary results are presented. (authors)

  18. Cell probing by delayed luminescence

    Musumeci, Francesco; Ballerini, Monica; Baroni, Giuliana; Costato, Michele; Ferraro, Lorenzo; Milani, Marziale; Scordino, Agata; Triglia, Antonio

    1999-05-01

    Delayed luminescence (D.L.) is a measure that provides important information on biological systems fields, structures and activities, by counting impinging and emitted photons. Many recent experimental works have shown the existence of a close connection, sometimes analytically expressed between the biological state of the system and D.L. parameters. Our investigations aim to show that D.L. is a workable analytical technique covering a large number of disciplinary fields, from agriculture to pollution control and from medical diagnostics to food quality control. The authors have conducted systematic research about D.L. from unicellular alga Acetabularia acetabulum to Saccharomyces cerevisiae yeast cultures and about more complex systems such as Soya seed (Glycine max, L.) and its dependence on sample preparation, history, intracellular signaling, metabolism and pollutant presence. We will discuss the most relevant results together with theoretical considerations on the basic interaction at work between biological systems and electromagnetic fields.

  19. Testing the spherical evolution of cosmic voids

    Demchenko, Vasiliy; Heymans, Catherine; Peacock, John A

    2016-01-01

    We study the spherical evolution model for voids in $\\Lambda$CDM, where the evolution of voids is governed by dark energy at an earlier time than that for the whole universe or in overdensities. We show that the presence of dark energy suppresses the growth of peculiar velocities, causing void shell-crossing to occur at progressively later epochs as $\\Omega_{\\Lambda}$ increases. We apply the spherical model to evolve the initial conditions of N-body simulated voids and compare the resulting final void profiles. We find that the model is successful in tracking the evolution of voids with radii greater than $30 h^{-1} \\rm Mpc$, implying that void profiles could be used to constrain dark energy. We find that the initial peculiar velocities of voids play a significant role in shaping their evolution. Excluding the peculiar velocity in the evolution model delays the time of shell crossing.

  20. Testing the spherical evolution of cosmic voids

    Demchenko, Vasiliy; Cai, Yan-Chuan; Heymans, Catherine; Peacock, John A.

    2016-08-01

    We study the spherical evolution model for voids in ΛCDM, where the evolution of voids is governed by dark energy at an earlier time than that for the whole universe or in overdensities. We show that the presence of dark energy suppresses the growth of peculiar velocities, causing void shell-crossing to occur at progressively later epochs as ΩΛ increases. We apply the spherical model to evolve the initial conditions of N-body simulated voids and compare the resulting final void profiles. We find that the model is successful in tracking the evolution of voids with radii greater than 30 h-1Mpc, implying that void profiles could be used to constrain dark energy. We find that the initial peculiar velocities of voids play a significant role in shaping their evolution. Excluding the peculiar velocity in the evolution model delays the time of shell crossing.

  1. Stochastic switching in delay-coupled oscillators.

    D'Huys, Otti; Jüngling, Thomas; Kinzel, Wolfgang

    2014-09-01

    A delay is known to induce multistability in periodic systems. Under influence of noise, coupled oscillators can switch between coexistent orbits with different frequencies and different oscillation patterns. For coupled phase oscillators we reduce the delay system to a nondelayed Langevin equation, which allows us to analytically compute the distribution of frequencies and their corresponding residence times. The number of stable periodic orbits scales with the roundtrip delay time and coupling strength, but the noisy system visits only a fraction of the orbits, which scales with the square root of the delay time and is independent of the coupling strength. In contrast, the residence time in the different orbits is mainly determined by the coupling strength and the number of oscillators, and only weakly dependent on the coupling delay. Finally we investigate the effect of a detuning between the oscillators. We demonstrate the generality of our results with delay-coupled FitzHugh-Nagumo oscillators. PMID:25314515

  2. Delay banking for air traffic management

    Green, Steven M. (Inventor)

    2007-01-01

    A method and associated system for time delay banking for aircraft arrival time, aircraft departure time and/or en route flight position. The delay credit value for a given flight may decrease with passage of time and may be transferred to or traded with other flights having the same or a different user (airline owner or operator). The delay credit value for a given aircraft flight depends upon an initial delay credit value, which is determined by a central system and depends upon one or more other flight characteristics. Optionally, the delay credit value decreases with passage of time. Optionally, a transaction cost is assessed against a delay credit value that is used on behalf of another flight with the same user or is traded with a different user.

  3. Time Delay Estimation Algoritms for Echo Cancellation

    Boris Simak

    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.

  4. Dynamics of Nonlinear Time-Delay Systems

    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...

  5. Delayed Self-Synchronization in Homoclinic Chaos

    Arecchi, F. T.; Meucci, R.; E. Allaria; Di Garbo, A.; Tsimring, L. S.

    2001-01-01

    The chaotic spike train of a homoclinic dynamical system is self-synchronized by re-inserting a small fraction of the delayed output. Due to the sensitive nature of the homoclinic chaos to external perturbations, stabilization of very long periodic orbits is possible. On these orbits, the dynamics appears chaotic over a finite time, but then it repeats with a recurrence time that is slightly longer than the delay time. The effect, called delayed self-synchronization (DSS), displays analogies ...

  6. Terrestrial Planet Finder cryogenic delay line development

    Smythe, Robert F.; Swain, Mark R.; Alvarez-Salazar, Oscar; Moore, James D.

    2004-01-01

    Delay lines provide the path-length compensation that makes the measurement of interference fringes possible. When used for nulling interferometry, the delay line must control path-lengths so that the null is stable and controlled throughout the measurement. We report on a low noise, low disturbance, and high bandwidth optical delay line capable of meeting the TPF interferometer optical path length control requirements at cryogenic temperatures.

  7. Bubbling in delay-coupled lasers

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

    2009-01-01

    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 co...

  8. Network Delay Inference from Additive Metrics

    Bhamidi, Shankar; Rajagopal, Ram; Roch, Sebastien

    2006-01-01

    We demonstrate the use of computational phylogenetic techniques to solve a central problem in inferential network monitoring. More precisely, we design a novel algorithm for multicast-based delay inference, i.e. the problem of reconstructing the topology and delay characteristics of a network from end-to-end delay measurements on network paths. Our inference algorithm is based on additive metric techniques widely used in phylogenetics. It runs in polynomial time and requires a sample of size ...

  9. Lensing Time Delays and Cosmological Complementarity

    Linder, Eric V.

    2011-01-01

    Time delays in strong gravitational lensing systems possess significant complementarity with distance measurements to determine the dark energy equation of state, as well as the matter density and Hubble constant. Time delays are most useful when observations permit detailed lens modeling and variability studies, requiring high resolution imaging, long time monitoring, and rapid cadence. We quantify the constraints possible between a sample of 150 such time delay lenses and a near term supern...

  10. Delay in camera-to-display systems

    2011-01-01

    Today we see an increasing number of time dependent visual computer systems, ranging from interactive video installations, via high definition teleconferencing to the high performance computer vision disciplines for example in industry and robotics. Common for all of these are the requirement for low and predictable delays from the system itself and its components. In this thesis, we look into the delay of camera-to-display computer systems to understand the properties of their delay com...

  11. Construction delay analysis of EDA Center building

    Tomažič, Denis

    2011-01-01

    This theses deals with the analysis of building construction and timeline of the project using the delay calculation method. The first and the second part are devoted to building presentation and construction characteristic technology, diversification work phases, facility structure and technological work processes. The third and the fourth part presents in detail the method for calculating the delay based on various reasons, such as the delay that happened for not anchoring the tower cran...

  12. Dimensional reduction of nonlinear time delay systems

    M. S. Fofana

    2005-01-01

    infinite-dimensional problem without the assumption of small time delay. This dimensional reduction is illustrated in this paper with the delay versions of the Duffing and van der Pol equations. For both nonlinear delay equations, transcendental characteristic equations of linearized stability are examined through Hopf bifurcation. The infinite-dimensional nonlinear solutions of the delay equations are decomposed into stable and centre subspaces, whose respective dimensions are determined by the linearized stability of the transcendental equations. Linear semigroups, infinitesimal generators, and their adjoint forms with bilinear pairings are the additional candidates for the infinite-dimensional reduction.

  13. Time delay plots of unflavoured baryons

    Kelkar, N. G.; Nowakowski, M.; Khemchandani, K. P.; Jain, S. R.

    2004-01-01

    We explore the usefulness of the existing relations between the S-matrix and time delay in characterizing baryon resonances in pion-nucleon scattering. We draw attention to the fact that the existence of a positive maximum in time delay is a necessary criterion for the existence of a resonance and should be used as a constraint in conventional analyses which locate resonances from poles of the S-matrix and Argand diagrams. The usefulness of the time delay plots of resonances is demonstrated through a detailed analysis of the time delay in several partial waves of πN elastic scattering.

  14. Reducing Transmitted Vibration Using Delayed Hysteretic Suspension

    Lahcen Mokni

    2011-01-01

    Full Text Available Previous numerical and experimental works show that time delay technique is efficient to reduce transmissibility of vibration in a single pneumatic chamber by controlling the pressure in the chamber. The present work develops an analytical study to demonstrate the effectiveness of such a technique in reducing transmitted vibrations. A quarter-car model is considered and delayed hysteretic suspension is introduced in the system. Analytical predictions based on perturbation analysis show that a delayed hysteretic suspension enhances vibration isolation comparing to the case where the nonlinear damping is delay-independent.

  15. Group Delay of High Q Antennas

    Bahramzy, Pevand; Pedersen, Gert Frølund

    2013-01-01

    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....

  16. A Boolean delay equation model of ENSO variability

    Saunders, Amira; Ghil, Michael

    2001-12-01

    Boolean delay equations (BDEs) provide a mathematical framework to formulate and analyze conceptual models of complex multi-component systems. This framework is used here to construct a simple conceptual model for the El-Niño/Southern Oscillation (ENSO) phenomenon. ENSO involves the coupling of atmospheric and oceanic processes that are far from being completely understood. Our BDE model uses Boolean variables to represent key atmospheric and oceanic quantities and equations that involve logical operators to describe their evolution. Two distinct time-delay parameters, one for the local atmosphere-ocean coupling effects and the other for oceanic wave propagation, are introduced. Over a range of physically relevant delay values, this truly minimal model captures two essential features of ENSO’s interannual variability - its regularity and its tendency to phase-lock to the annual cycle. Oscillations with average cycle length that is an integer multiple of the seasonal cycle are prevalent and range from 2 to 7 years. Transition zones - where the average period lengths are noninteger rational multiples of the forcing period - exhibit Devil’s staircases, a signature of the quasi-periodic (QP) route to chaos. Our BDE model thus validates results from previous studies of the interaction of the seasonal cycle with ENSO’s “delayed oscillator”. It gives therewith support to the view that the observed irregularity results predominantly from low-order chaotic processes rather than from stochastic weather noise. Moreover, in the transition zone between the two integer periodicities of 2 and 3 years, a heretofore unsuspected, self-similar “fractal sunburst” pattern emerges in phase-parameter space. This pattern provides a distinct and more complex scenario than the QP route to chaos found in earlier, more detailed ENSO models. Period selection in this 2-3-year transitional region seems to play a key role in ENSO’s irregularity, as well as in the appearance of

  17. Analysis of fluctuations in transient states in a non-linear nuclear reactor model with delayed neutrons

    We study the behaviour of neutron fluctuations during the transient regime in a non-linear reactor model with an instantaneous feedback effect and delayed neutrons. We consider a master equation description modellizing the internal fluctuations and apply the system-size expansion method in order to obtain the evolution equations of the fluctuations. The appearance of an enhancement of the fluctuations and the effect of delayed neutrons is analysed. The reliability of the deterministic approach is discussed. (author)

  18. A novel heterozygous mutation in the ATP6V0A4 gene encoding the V-ATPase a4 subunit in an adult patient with incomplete distal renal tubular acidosis.

    Imai, Eri; Kaneko, Shuzo; Mori, Takayasu; Okado, Tomokazu; Uchida, Shinichi; Tsukamoto, Yusuke

    2016-06-01

    A 40-year-old Japanese man who had a medical history of hypokalemic periodic paralysis 4 months prior was hospitalized to undergo a cholecystectomy. Hypokalemia, nephrocalcinosis and alkaluria suggesting distal renal tubular acidosis (dRTA) were detected, but metabolic acidosis was not evident. An ammonium chloride/furosemide-fludrocortisone/bicarbonate loading test demonstrated a remarkable disability in urinary H(+) excretion. A novel heterozygous mutation in the ATP6V0A4 gene encoding the vacuolar H(+)-ATPase (V-ATPase) a4 subunit p.S544L was detected. Among cases of V-ATPase a4 mutations, this is the first case in which a heterozygous mutation developed to an incomplete or latent form of dRTA. PMID:27274828

  19. Representing Evolution

    Hedin, Gry

    2012-01-01

    article discusses Willumsen's etching in the context of evolutionary theory, arguing that Willumsen is a rare example of an artist who not only let the theory of evolution fuel his artistic imagination, but also concerned himself with a core issue of the theory, namely to what extent it could be applied...

  20. Cepheid evolution

    A review of the phases of stellar evolution relevant to Cepheid variables of both Types I and II is presented. Type I Cepheids arise as a result of normal post-main sequence evolutionary behavior of many stars in the intermediate to massive range of stellar masses. In contrast, Type II Cepheids generally originate from low-mass stars of low metalicity which are undergoing post core helium-burning evolution. Despite great progress in the past two decades, uncertainties still remain in such areas as how to best model convective overshoot, semiconvection, stellar atmospheres, rotation, and binary evolution as well as uncertainties in important physical parameters such as the nuclear reaction rates, opacity, and mass loss rates. The potential effect of these uncertainties on stellar evolution models is discussed. Finally, comparisons between theoretical predictions and observations of Cepheid variables are presented for a number of cases. The results of these comparisons show both areas of agreement and disagreement with the latter result providing incentive for further research

  1. L-Arginine Affects Aerobic Capacity and Muscle Metabolism in MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-Like Episodes Syndrome.

    Lance H Rodan

    Full Text Available To study the effects of L-arginine (L-Arg on total body aerobic capacity and muscle metabolism as assessed by (31Phosphorus Magnetic Resonance Spectroscopy ((31P-MRS in patients with MELAS (Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes syndrome.We performed a case control study in 3 MELAS siblings (m.3243A>G tRNA(leu(UUR in MTTL1 gene with different % blood mutant mtDNA to evaluate total body maximal aerobic capacity (VO(2peak using graded cycle ergometry and muscle metabolism using 31P-MRS. We then ran a clinical trial pilot study in MELAS sibs to assess response of these parameters to single dose and a 6-week steady-state trial of oral L-Arginine.At baseline (no L-Arg, MELAS had lower serum Arg (p = 0.001. On 3(1P-MRS muscle at rest, MELAS subjects had increased phosphocreatine (PCr (p = 0.05, decreased ATP (p = 0.018, and decreased intracellular Mg(2+ (p = 0.0002 when compared to matched controls. With L-arginine therapy, the following trends were noted in MELAS siblings on cycle ergometry: (1 increase in mean % maximum work at anaerobic threshold (AT (2 increase in % maximum heart rate at AT (3 small increase in VO(2peak. On (31P-MRS the following mean trends were noted: (1 A blunted decrease in pH after exercise (less acidosis (2 increase in Pi/PCr ratio (ADP suggesting increased work capacity (3 a faster half time of PCr recovery (marker of mitochondrial activity following 5 minutes of moderate intensity exercise (4 increase in torque.These results suggest an improvement in aerobic capacity and muscle metabolism in MELAS subjects in response to supplementation with L-Arg. Intramyocellular hypomagnesemia is a novel finding that warrants further study.Class III evidence that L-arginine improves aerobic capacity and muscle metabolism in MELAS subjects.ClinicalTrials.gov NCT01603446.

  2. Delay Banking for Managing Air Traffic

    Green, Steve

    2008-01-01

    Delay banking has been invented to enhance air-traffic management in a way that would increase the degree of fairness in assigning arrival, departure, and en-route delays and trajectory deviations to aircraft impacted by congestion in the national airspace system. In delay banking, an aircraft operator (airline, military, general aviation, etc.) would be assigned a numerical credit when any of their flights are delayed because of an air-traffic flow restriction. The operator could subsequently bid against other operators competing for access to congested airspace to utilize part or all of its accumulated credit. Operators utilize credits to obtain higher priority for the same flight, or other flights operating at the same time, or later, in the same airspace, or elsewhere. Operators could also trade delay credits, according to market rules that would be determined by stakeholders in the national airspace system. Delay banking would be administered by an independent third party who would use delay banking automation to continually monitor flights, allocate delay credits, maintain accounts of delay credits for participating airlines, mediate bidding and the consumption of credits of winning bidders, analyze potential transfers of credits within and between operators, implement accepted transfers, and ensure fair treatment of all participating operators. A flow restriction can manifest itself in the form of a delay in assigned takeoff time, a reduction in assigned airspeed, a change in the position for the aircraft in a queue of all aircraft in a common stream of traffic (e.g., similar route), a change in the planned altitude profile for an aircraft, or change in the planned route for the aircraft. Flow restrictions are typically imposed to mitigate traffic congestion at an airport or in a region of airspace, particularly congestion due to inclement weather, or the unavailability of a runway or region of airspace. A delay credit would be allocated to an operator of a

  3. Deficiency of the reduced nicotinamide adenine dinucleotide dehydrogenase component of complex I of mitochondrial electron transport. Fatal infantile lactic acidosis and hypermetabolism with skeletal-cardiac myopathy and encephalopathy.

    Hoppel, C L; Kerr, D S; Dahms, B; Roessmann, U

    1987-01-01

    A mitochondrial defect was investigated in an infant with fatal congenital lactic acidosis (3-14 mM), high lactate-to-pyruvate ratio, hypotonia, and cardiomyopathy. His sister had died with a similar disorder. Resting oxygen consumption was 150% of controls. Pathological findings included increased numbers of skeletal muscle mitochondria (many with proliferated, concentric cristae), cardiomegaly, fatty infiltration of the viscera, and spongy encephalopathy. Mitochondria from liver and muscle ...

  4. Delays in Referral of Soft Tissue Sarcomas

    G. D. Johnson

    2008-01-01

    Full Text Available Introduction and aims. It is well established that soft tissue sarcomas (STSs are more effectively treated in a specialist centre. However, delays in time taken for a patient to be referred to a specialist centre may lead to a poorer prognosis. This study aims to identify the length of these delays and where they occur. Patients and methods. Patients with a proven STS were included. They were recruited from both outpatient clinics and from the surgical ward of the Royal Orthopaedic Hospital (Birmingham, UK. A structured interview was used to take a detailed history of the patients' treatment pathway, before arriving at the specialist centre. Dates given were validated using the case notes. Results. The median time for the patient to present to a specialist centre from the onset of symptoms was 40.4 weeks. The median delay until presentation to a medical professional (patient delay was 1.3 weeks. Median delay in referral to a specialist centre (service delay was 25.0 weeks. Discussion. Medical professionals rather than patients contribute the greatest source of delay in patients reaching a specialist centre for treatment of STS. Adherence to previously published guidelines could decrease this delay for diagnosis of possible sarcoma. Steps should be taken to refer patients directly to a diagnostic centre if they have symptoms or signs suggestive of STS.

  5. Delayed Encephalopathy Associated with Carbon Monoxide Intoxication

    Huseyin Aydin

    2011-01-01

    Full Text Available Acute carbon monoxide intoxication may cause coma and death. Patients usually recovier within days after prompt therapy. However, in a small number of patients, severe clinical deterioration may develop after a period with no apparent abnormality. This is called delayed type encephalopathy. We present MR imaging findings of a case of delayed encephalopathy due to carbon monoxide intoxication.

  6. Delayed Encephalopathy Associated with Carbon Monoxide Intoxication

    Hüseyin Aydın; Mürüvet Akın; Emel Boyraz; Murat Çolakkaya

    2011-01-01

    Acute carbon monoxide intoxication may cause coma and death. Patients usually recovier within days after prompt therapy. However, in a small number of patients, severe clinical deterioration may develop after a period with no apparent abnormality. This is called delayed type encephalopathy. We present MR imaging findings of a case of delayed encephalopathy due to carbon monoxide intoxication.

  7. Delay generation methods with reduced memory requirements

    Tomov, Borislav Gueorguiev; Jensen, Jørgen Arendt

    2003-01-01

    Modern diagnostic ultrasound beamformers require delay information for each sample along the image lines. In order to avoid storing large amounts of focusing data, delay generation techniques have to be used. In connection with developing a compact beamformer architecture, recursive algorithms were...

  8. Test Anxiety and Academic Delay of Gratification

    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…

  9. Delays in the management of retroperitoneal sarcomas

    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 sarc...... indicate that development of coordinated diagnostic packages could shorten delays at the sarcoma centre....

  10. Congenital rubella syndrome and delayed manifestations

    Dammeyer, Jesper Herup

    2010-01-01

    Objective: Several hypotheses of different medical and psychological delayed manifestations among people who have congenital rubella syndrome (CRS) have been discussed. This study tests some of these hypotheses of delayed manifestations. Methods: Gathering information about 35 individuals who have...

  11. Trichothiodystrophy with sideroblastic anaemia and developmental delay.

    Lynch, S A; de Berker, D; Lehmann, A R; Pollitt, R. J.; Reid, M. M.; Lamb, W.H.

    1995-01-01

    A patient with sideroblastic anaemia, development delay, and trichothiodystrophy is presented. Trichothiodystrophy is a feature of several autosomal recessive diseases. Photosensitivity, failure to thrive, and developmental delay are commonly observed in affected cases. X linked inheritance accounts for the bulk of cases with sideroblastic anaemia. This case highlights the importance of routine hair microscopy in cases of atypical ectodermal dysplasia.

  12. Accelerating Smaller Cutbacks to Delay Larger Ones?

    Tepe, Markus; Vanhuysse, Pieter

    effects of unemployment and population aging: these socio-demographic variables tend to delay large-size cutbacks, but to accelerate medium-size cutbacks in pension generosity, possibly because they function as alarm bell signals urging policymakers to take still feasible incremental action through...... ‘muddling-through type’ retrenchment in order to delay more radical and politically highly risky retrenchment....

  13. Stabilization of a Nonlinear Delay System

    Walid Arouri

    2012-01-01

    Full Text Available Problem statement: The analysis and control of delayed systems are becoming more and more research topics in progress. This is mainly due to the fact that the delay is frequently encountered in technological systems. This can affect their significantly operations. Most control command laws are based on current digital computers and delays are intrinsic to the process or in the control loop caused by the transmission time control sequences, or computing time. The delay may affect one or more states of the considered system. It may also affect the establishment of the command. Several studies have investigated the stability of delay systems under the assumption that the delay is a variable phenomenon; such variation is considered to be bounded or limited to facilitate analysis of the system. In this study we propose a modelling of delayed system by using the multimodels and switched system theory. The analysis of stability is based on the use of second Lyapunov method. The issued stability conditions are expressed as Bilinear Matrix Inequalities impossible to resolve. That’s why we propose the same original relaxations to come over this difficulty, an example of induction machine is given to illustrate over approach. Approach: We propose to use the control theory developed for switched systems to synthesis a control laws for the stabilisation of delays system. Results: We stabilize the induction machine around many operating points despite the non linearities. Conclusion: The developed method is less conservative and less pessimistic than the used classical methods.

  14. Delaying Developmental Mathematics: The Characteristics and Costs

    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…

  15. Analyzing delay causes in Egyptian construction projects

    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.

  16. Algebraic entropy for differential-delay equations

    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.

  17. Programmable delay circuit for sparker signal analysis

    Pathak, D.

    on it to classify the seafloor sediment properties. A specific purpose oriented programmable delay circuit was developed to generate the necessary delay so that the A/D conversion could start just before the arrival of the echo from the water bottom interface...

  18. Delaying gratification depends on social trust

    LauraMichaelson

    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.

  19. On Delay and Security in Network Coding

    Dikaliotis, Theodoros K.

    2013-01-01

    In this thesis, delay and security issues in network coding are considered. First, we study the delay incurred in the transmission of a fixed number of packets through acyclic networks comprised of erasure links. The two transmission schemes studied are routing with hop-by-hop retransmissions, where every node in the network simply stores and…

  20. Discounting of Delayed Rewards Is Not Hyperbolic

    Luhmann, Christian C.

    2013-01-01

    Delay discounting refers to decision-makers' tendency to value immediately available goods more than identical goods available only after some delay. In violation of standard economic theory, decision-makers frequently exhibit dynamic inconsistency; their preferences change simply due to the passage of time. The standard explanation for this…

  1. Effects of elongation delay in transcription dynamics.

    Zhang, Xuan; Jin, Huiqin; Yang, Zhuoqin; Lei, Jinzhi

    2014-12-01

    In the transcription process, elongation delay is induced by the movement of RNA polymerases (RNAP) along the DNA sequence, and can result in changes in the transcription dynamics. This paper studies the transcription dynamics that involved the elongation delay and effects of cell division and DNA replication. The stochastic process of gene expression is modeled with delay chemical master equation with periodic coefficients, and is studied numerically through the stochastic simulation algorithm with delay. We show that the average transcription level approaches to a periodic dynamics over cell cycles at homeostasis, and the elongation delay can reduce the transcription level and increase the transcription noise. Moreover, the transcription elongation can induce bimodal distribution of mRNA levels that can be measured by the techniques of flow cytometry. PMID:25365608

  2. Photonic Quantum Circuits with Time Delays

    Pichler, Hannes

    2015-01-01

    We study the dynamics of photonic quantum circuits consisting of nodes coupled by quantum channels. We are interested in the regime where time delay in communication between the nodes is significant. This includes the problem of quantum feedback, where a quantum signal is fed back on a system with a time delay. We develop a matrix product state approach to solve the Quantum Stochastic Schr\\"odinger Equation with time delays, which accounts in an efficient way for the entanglement of nodes with the stream of emitted photons in the waveguide, and thus the non-Markovian character of the dynamics. We illustrate this approach with two paradigmatic quantum optical examples: two coherently driven distant atoms coupled to a photonic waveguide with a time delay, and a driven atom coupled to its own output field with a time delay as an instance of a quantum feedback problem.

  3. Switching control and time-delay identification

    Chen, Qi; Li, Xiang; Qin, Zhi-Chang; Zhong, Shun; Sun, J. Q.

    2014-12-01

    The unknown time delay makes the control design a difficult task. When the lower and upper bounds of an unknown time delay of dynamical systems are specified, one can design a supervisory control that switches among a set of controls designed for the sampled time delays in the given range so that the closed-loop system is stable and the control performance is maintained at a desirable level. In this paper, we propose to design a supervisory control to stabilize the system first. After the supervisory control converges, we start an algorithm to identify the unknown time delay, either on-line or off-line, with the known control being implemented. Examples are shown to demonstrate the stabilization and identification for linear time invariant and periodic systems with a single control time delay.

  4. Service Provider Competition: Delay Cost Structure, Segmentation, and Cost Advantage

    Maxim Afanasyev; Haim Mendelson

    2010-01-01

    We model competition between two providers who serve delay-sensitive customers. We compare a generalized delay cost structure, where a customer's delay cost depends on her service valuation, with the traditional additive delay cost structure, where the delay cost is independent of the customer's service valuation. Under the additive delay cost structure, service providers offer different prices and expected delays, but customers are indifferent between the providers. Under the generalized del...

  5. PRIMARY SJOGREN’S SYNDROME AND DISTAL RENAL TUBULAR ACIDOSIS: PRESENTING WITH NEPHROGENIC DIABETES INSI PIDUS SECONDARY TO SEVERE HYPOKALEMIA-A CASE REPORT

    Ksh. Achouba

    2013-02-01

    Full Text Available NTRODUCTION: Sjogren’s syndrome is a slowly progressing autoimmun e disease characterized by lymphocytic infiltration of the exo crine glands, mainly the lacrimal and salivary glands, resulting in their impaired secreto ry function. Simultaneously, systemic involvement and symptoms of cutaneous, respiratory, r enal, hepatic, neurologic, and vascular systems often occur.[ 1 ] This syndrome can present either alone (as primary Sjogren’s syndrome or in the context of an underlying connec tive tissue disease (as secondary Sjogren’s syndrome.[ 2 ] Renal involvement is a well recognized extra glan dular manifestation of primary Sjogren’s syndrome (pSS. Most common manifestations are related to tubular dysfunction, resulting from chronic interstitial nephritis, which can manifest as distal renal tubular acidosis (dRTA, proximal RTA(pRTA, tubular proteinuria, or nephrogenic diabetes insipidus.[ 3 , 4 ] Hypokalemic periodic paralysis, urolithiasis, or osteo malacia are uncommon renal manifestations of pSS.[ 1 ] Here, we present a case of primary Sjogren’s syndr ome predominantly presenting as a renal manifestation in the form of nephrogenic Diabetes Insipidus secondary to severe hypokalemia due to dRTA .

  6. EVALUATION OF MITOCHONDRIAL ENCEPHALOMYOPATHY WITH LACTIC ACIDOSIS AND STROKE-LIKE EPISODES WITH MAGNETIC RESONANCE IMAGING AND PROTON MAGNETIC RESONANCE SPECTROSCOPY

    Feng Feng; Hui You; Jing Gao; Xiao-zhen Li; Chun-ling Meng; Hong-yi Sun; Zheng-yu Jin; Yu-pu Guo

    2006-01-01

    Objective To study the characteristics of spectra on proton magnetic resonance spectroscopy (1H-MRS) and its value in patients with mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS).Methods Seven clinically diagnosed patients with MELAS underwent magnetic resonance imaging (MRI) and 1H-MRS examinations.The 1H-MRS techniques,characteristics of the spectra,and its correlation with the laboratory tests were analyzed.Results Cerebral abnormalities were revealed in all 7 patients on conventional MR images,and most abnormal signals were observed in bilateral occipital,parietal,and temporal lobes.We found 4 cases with basal ganglia involvement,2 cases with mild frontal lobe lesions,and 1 case with involvement of lateral cerebral peduncles and thalami.Additionally,1 patient was involved with left insular lobe.Spectra from prominent lesions in brain parenchyma showed lactate doublet peak in 6 patients,3 of whom were also noted lactate peak in ventricular cerebrospinal fluid (CSF).Conclusion 1H-MRS may provide more direct information about the metabolism changes,which aids to affirm the diagnosis,and may replace the conventional invasive method of quantifying lactate in CSF.

  7. Isochronal synchronization of time delay and delay-coupled chaotic systems

    Grzybowski, J. M. V.; Macau, E. E. N.; Yoneyama, T.

    2011-04-01

    This paper studies the problem of isochronal synchronization of time-delay chaotic systems featuring also coupling delay. Based on the Lyapunov-Krasovskii stability theory, sufficient conditions are derived for the stability of isochronal synchronization between a pair of identical chaotic systems. Such criteria permit the proper design of stable proportional linear feedback controller, more specifically, the design of adequate proportional feedback gain matrices. The proposed criteria are suited to systems with (i) intrinsic delay, (ii) coupling delay or (iii) both. Numerical simulations of the synchronization of delay-coupled systems are presented as examples of the application of the criteria.

  8. Novel delay-dependent robust stability criteria for uncertain neutral systems with time-varying delay

    The problem of delay-dependent robust stability for neutral control systems with time-varying delay and time-varying structured uncertainties is investigated. An improved linear matrix inequality-based delay-dependent stability test is introduced to ensure a large upper bound for time-delay. A new class of Lyapunov-Krasovskii functionals combined with the descriptor model transformation and the decomposition technique of coefficient matrix is constructed to derive some novel delay-dependent stability criteria. Finally, numerical examples are given to demonstrate the derived condition are much less conservative than those given in the literature.

  9. Mitochondrial Evolution

    Gray, Michael W

    2012-01-01

    Viewed through the lens of the genome it contains, the mitochondrion is of unquestioned bacterial ancestry, originating from within the bacterial phylum α-Proteobacteria (Alphaproteobacteria). Accordingly, the endosymbiont hypothesis—the idea that the mitochondrion evolved from a bacterial progenitor via symbiosis within an essentially eukaryotic host cell—has assumed the status of a theory. Yet mitochondrial genome evolution has taken radically different pathways in diverse eukaryotic lineag...

  10. Work in Greece on Delayed Neutrons

    At present, two programmes on delayed neutron research are in progress in Greece. Delayed Neutron Energy Spectrum Measurements. In an experiment at the 1 MW Democritus reactor, the energy of the delayed neutrons from 235U fission is measured by the time-of-flight technique and β-n-coincidence using a special fast system for irradiation of the sample. The beta particle preceding the emission of the delayed neutron is used as a start pulse while the delayed neutron provides a stop signal. A maximum flight time of approximately 100 nsec is allowed over a flight distance of approximately 30 cm (longer flight paths could be used for better energy resolution, but this would decrease the efficiency of detecting the delayed neutron). To avoid false measurements due to other beta particles which do not correspond to delayed neutrons, an anti-coincidence system is used to cancel the measurement whenever two beta particles come in a time interval shorter than 100 nsec. Coincidences due to delayed neutrons are relatively rare in comparison with chance coincidences or β-γ-coincidences. The spectrum obtained in a first run of measurements is discussed. An attempt will be made to measure the spectrum of each individual group by varying the irradiation time and the measuring time. Various irradiation, transfer and measuring times can be obtained with the existing experimental set-up. A minimum transfer time of 300 msec can be achieved. Very thin foils (a few mg/cm2) are used to minimize the beta-particle absorption in the sample. Delayed Neutron Group Relative Abundances And Periods. In a second experiment, measurements to determine the relative abundances and periods of the delayed neutrons for various fissile materials are now under way. The arrangement for delayed neutron group measurement allows the sample to be transferred in a minimum time of approximately 800 msec. Accordingly, delayed neutrons of quite short half-lives can be detected. The experimental facility permits

  11. Work in Greece on delayed neutrons

    At present, two programmes on delayed neutron research are in progress in Greece. DELAYED NEUTRON ENERGY SPECTRUM MEASUREMENTS. In an experiment at the 1 MW Democritus reactor, the energy of the delayed neutrons from 235U fission is measured by the time-of-flight technique and β-n-coincidence using a special fast system for irradiation of the sample. The beta particle preceding the emission of the delayed neutron is used as a start pulse while the delayed neutron provides a stop signal. A maximum flight time of approximately 100 nsec is allowed over a flight distance of approximately 30 cm (longer flight paths could be used for better energy resolution, but this would decrease the efficiency of detecting the delayed neutron). To avoid false measurements due to other beta particles which do not correspond to delayed neutrons, an anti-coincidence system is used to cancel the measurement whenever two beta particles come in a time interval shorter than 100 nsec. Coincidences due to delayed neutrons are relatively rare in comparison with chance coincidences or β-γ-coincidences. The spectrum obtained in a first run of measurements is discussed. An attempt will be made to measure the spectrum of each individual group by varying the irradiation time and the measuring time. Various irradiation, transfer and measuring times can be obtained with the existing experimental set-up. A minimum transfer time of 300 msec can be achieved. Very thin foils (a few mg/cm2) are used to minimize the beta-particle absorption in the sample. DELAYED NEUTRON GROUP RELATIVE ABUNDANCES AND PERIODS. In a second experiment, measurements to determine the relative abundances and periods of the delayed neutrons for various fissile materials are now under way. The arrangement for delayed neutron group measurement allows the sample to be transferred in a minimum time of approximately 800 msec. Accordingly, delayed neutrons of quite short half-lives can be detected. The experimental facility permits

  12. Splicing mutation in CYP21 associated with delayed presentation of salt-wasting congenital adrenal hyperplasia

    Kohn, B.; Patel, S.V.; Pelczar, J.V. [North Shore Univ. Hospital, Manhasset, NY (United States)] [and others

    1995-07-03

    Patients with salt-wasting congenital adrenal hyperplasia (SW-CAH) most commonly carry an A-G transition at nucleotide 656 (nt 656 A{r_arrow}G), causing abnormal splicing of exons 2 and 3 in CYP21, the gene encoding active steroid 21-hydroxylase. Affected infants are severely deficient in cortisol and aldosterone, and usually come to medical attention during the neonatal period. We report on 2 affected boys, homozygous for the nt 656 mutation, who thrived in early infancy, but suffered salt-wasting crises unusually late in infancy, at 3.5 and 5.5 months, respectively. Laboratory studies at presentation showed hyponatremia, hyperkalemia, dehydration, and acidosis; serum aldosterone was low in spite of markedly elevated plasma renin activity. Basal 17-hydroxyprogesterone levels were only moderately elevated, yet the stimulated levels were more typical of severe, classic CAH due to 21-hydroxylase deficiency. Genomic DNA from the patients was analyzed. Southern blot showed no major deletions or rearrangements. CYP21-specific amplification by polymerase chain reaction, coupled with allele-specific hybridization using wild-type and mutant probes at each of 9 sites for recognized disease-causing mutations, revealed a single, homozygous mutation in each patient: nt 656 A{r_arrow}G. These results were confirmed by sequence analysis. We conclude that the common nt 656 A{r_arrow}G mutation is sometimes associated with delayed phenotypic expression of SW-CAH. We speculate that variable splicing of the mutant CYP21 may modify the clinical manifestation of this disease. 22 refs., 1 fig., 1 tab.

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

    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)

  14. Delayed feedback applied to breathing in humans

    Janson, N. B.; Pototsky, A.; Parkes, C.

    2013-10-01

    We studied the response of healthy volunteers to the delayed feedback generated from the breathing signals. Namely, in the freely-breathing volunteers the breathing signal was recorded, delayed by τ seconds and fed back to the same volunteer in real time in the form of a visual and auditory stimulus of low intensity, i.e. the stimulus was crucially non-intrusive. In each case volunteers were instructed to breathe in the way which was most comfortable for them, and no explanation about the kind of applied stimulus was provided to them. Each volunteer experienced 10 different delay times ranging between 10% and 100% of the average breathing period without external stimulus. It was observed that in a significant proportion of subjects (11 out of 24) breathing was slowed down in the presence of delayed feedback with moderate delay. Also, in 6 objects out of 24 the delayed feedback was able to induce transition from nearly periodic to irregular breathing. These observations are consistent with the phenomena observed in numerical simulation of the models of periodic and chaotic self-oscillations with delays, and also in experiments with simpler self-oscillating systems.

  15. Delays in Building Construction Projects in Ghana

    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.

  16. Delayed self-synchronization in homoclinic chaos

    Arecchi, F. T.; Meucci, R.; Allaria, E.; di Garbo, A.; Tsimring, L. S.

    2002-04-01

    The chaotic spike train of a homoclinic dynamical system is self-synchronized by applying a time-delayed correction proportional to the laser output intensity. Due to the sensitive nature of the homoclinic chaos to external perturbations, stabilization of very long-periodic orbits is possible. On these orbits, the dynamics appears chaotic over a finite time, but then it repeats with a recurrence time that is slightly longer than the delay time. The effect, called delayed self-synchronization, displays analogies with neurodynamic events that occur in the buildup of long-term memories.

  17. Delayed encephalopathy after acute carbon monoxide poisoning

    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.

  18. Technical Progress of China's Delayed Coking Technology

    Zhang Lixin; Li Hejie

    2005-01-01

    This article introduces the recent advances of China in the fields of process technology of delayed coking, enlarged equipment size, hydraulic decoking, automatic control and environmental protection. By the end of 2004 the total capacity of delayed coking units in China had reached 37.24Mt/a with the maximum coke drum diameter equating to 9.4 m. This article also presents the investment in delayed cokers and the current production status while pointing out the existing problems and future development trends.

  19. Synchronisation of time-delay systems

    Bünner, M J; Bünner, Martin J.; Just, Wolfram

    1998-01-01

    We present the linear-stability analysis of synchronised states in coupled time-delay systems. There exists a synchronisation threshold, for which we derive upper bounds, which does not depend on the delay time. We prove that at least for scalar time-delay systems synchronisation is achieved by transmitting a single scalar signal, even if the synchronised solution is given by a high-dimensional chaotic state with a large number of positive Lyapunov-exponents. The analytical results are compared with numerical simulations of two coupled Mackey-Glass equations.

  20. Finite time stabilization of delayed neural networks.

    Wang, Leimin; Shen, Yi; Ding, Zhixia

    2015-10-01

    In this paper, the problem of finite time stabilization for a class of delayed neural networks (DNNs) is investigated. The general conditions on the feedback control law are provided to ensure the finite time stabilization of DNNs. Then some specific conditions are derived by designing two different controllers which include the delay-dependent and delay-independent ones. In addition, the upper bound of the settling time for stabilization is estimated. Under fixed control strength, discussions of the extremum of settling time functional are made and a switched controller is designed to optimize the settling time. Finally, numerical simulations are carried out to demonstrate the effectiveness of the obtained results. PMID:26264170

  1. ON FEEDBACK CONTROL OF DELAYED CHAOTIC SYSTEM

    李丽香; 彭海朋; 卢辉斌; 关新平

    2001-01-01

    In this paper two different types of feedback control technique are discussed: the standard feedback control and the time-delay feedback control which have been successfully used in many control systems. In order to understand to what extent the two different types of control technique are useful in delayed chaotic systems, some analytic stabilization conditions for chaos control from the two types of control technique are derived based on Lyapunov stabilization arguments. Similarly, we discuss the tracking problem by applying the time-delay feedback control. Finally, numerical examples are provided.

  2. Impulsive fractional differential inclusions with infinite delay

    Khalida Aissani

    2013-11-01

    Full Text Available In this article, we apply Bohnenblust-Karlin's fixed point theorem to prove the existence of mild solutions for a class of impulsive fractional equations inclusions with infinite delay. An example is given to illustrate the theory.

  3. Diagrammatic approach to attosecond delays in photoionization

    Dahlström, J M; Lindroth, E

    2012-01-01

    We study laser-assisted photoionization by attosecond pulses using a time-independent formalism based on diagrammatic many-body perturbation theory. Our aim is to provide an ab inito route to the "delays" for this above-threshold ionization process, which is essential for a quantitative understanding of attosecond metrology. We present correction curves for characterization schemes of attosecond pulses, such as "streaking", that account for the delayed atomic response in ionization from neon and argon. We also verify that photoelectron delays from many-electron atoms can be measured using similar schemes if, instead, the so-called continuum--continuum delay is subtracted. Our method is general and it can be extended also to more complex systems and additional correlation effects can be introduced systematically.

  4. Ranking different factors influencing flight delay

    Meysam Kazemi Asfe

    2014-07-01

    Full Text Available Flight interruption is one of the most important issues in today’s airline industry. Every year, most airlines spend significant amount of money to compensate flight delays. Therefore, it is important to detect important factors influencing on flight delays. This paper presents an empirical investigation to determine important factors on this issue. The study also asks some decision makers to make pairwise comparison and ranks various factors using the art of analytical hierarchy process. The study determines that technical defects and delayed entry were among the most important factors to blame for flight delays. In addition, announcing the postponement, replacement aircraft and path replacement are among the most important decisions facing managers in the aviation industry during the disruption of the flight.

  5. SBASI: Actuated pyrotechnic time delay initiator

    Salter, S. J.; Lundberg, R. E.; Mcdougal, G. L.

    1975-01-01

    A precision pyrotechnic time delay initiator for missile staging was developed and tested. Incorporated in the assembly is a single bridgewire Apollo standard initiator (SBASI) for initiation, a through-bulkhead-initiator to provide isolation of the SBASI output from the delay, the pyrotechnic delay, and an output charge. An attempt was made to control both primary and secondary variables affecting functional performance of the delay initiator. Design and functional limit exploration was performed to establish tolerance levels on manufacturing and assembling operations. The test results demonstrate a 2% coefficient of variation at any one temperature and an overall 2.7% coefficient of variation throughout the temperature range of 30 to 120 F. Tests were conducted at simulated operational altitude from sea level to 200,000 feet.

  6. Internet end-to-end delay dynamics

    Zhu Changhua; Pei Changxing; Li Jiandong; Chen Nan; Yi Yunhui

    2006-01-01

    End-to-end delay is one of the most important characteristics of Internet end-to-end packet dynamics, which can be applied to quality of services (QoS) management, service level agreement (SLA) management, congestion control algorithm development, etc. Nonstationarity and nonlinearity are found by the analysis of various delay series measured from different links. The fact that different types of links have different degree of Self-Similarity is also obtained. By constructing appropriate network architecture and neural functions, functional networks can be used to model the Internet end-to-end nonlinear delay time series. Furthermore, by using adaptive parameter studying algorithm, the nonstationarity can also be well modeled. The numerical results show that the provided functional network architecture and adaptive algorithm can precisely characterize the Internet end-to-end delay dynamics.

  7. Lauch of CERN particle accelerator delayed

    2007-01-01

    "Scientists seeking to uncover the secrets of the universe will have to wait a little longer after the CERN laboratory inSwitzerland yesterday confirmed a delay in tests of its massive new particle accelerator." (1 page)

  8. The SAS-3 delayed command system

    Hoffman, E. J.

    1975-01-01

    To meet the requirements arising from the increased complexity of the power, attitude control and telemetry systems, a full redundant high-performance control section with delayed command capability was designed for the Small Astronomy Satellite-3 (SAS-3). The relay command system of SAS-3 is characterized by 56 bystate relay commands, with capability for handling up to 64 commands in future versions. The 'short' data command service of SAS-1 and SAS-2 consisting of shifting 24-bit words to two users was expanded to five users and augmented with a 'long load' data command service (up to 4080 bits) used to program the telemetry system and the delayed command subsystem. The inclusion of a delayed command service ensures a program of up to 30 relay or short data commands to be loaded for execution at designated times. The design and system operation of the SAS-3 command section are analyzed, with special attention given to the delayed command subsystem.

  9. Delay Time in Quaternionic Quantum Mechanics

    De Leo, Stefano

    2012-01-01

    In looking for quaternionic violations of quantum mechanics, we discuss the delay time for pure quaternionic potentials. The study shows in which energy region it is possible to amplify the difference between quaternionic and complex quantum mechanics.

  10. Tropospheric Delay Raytracing Applied in VLBI Analysis

    MacMillan, D. S.; Eriksson, D.; Gipson, J. M.

    2013-12-01

    Tropospheric delay modeling error continues to be one of the largest sources of error in VLBI analysis. For standard operational solutions, we use the VMF1 elevation-dependent mapping functions derived from ECMWF data. These mapping functions assume that tropospheric delay at a site is azimuthally symmetric. As this assumption does not reflect reality, we have determined the raytrace delay along the signal path through the troposphere for each VLBI quasar observation. We determined the troposphere refractivity fields from the pressure, temperature, specific humidity and geopotential height fields of the NASA GSFC GEOS-5 numerical weather model. We discuss results from analysis of the CONT11 R&D and the weekly operational R1+R4 experiment sessions. When applied in VLBI analysis, baseline length repeatabilities were better for 66-72% of baselines with raytraced delays than with VMF1 mapping functions. Vertical repeatabilities were better for 65% of sites.

  11. Four-channel delay generator model 5740

    The 4-channel delay generator model 5740 generates 4-pulse groups in independent channels. The device offers the possibility of controlling both the time intervals between the pulses of a group and the rate of generation of groups

  12. Lensing Time Delays and Cosmological Complementarity

    Linder, Eric V

    2011-01-01

    Time delays in strong gravitational lensing systems possess significant complementarity with distance measurements to determine the dark energy equation of state, as well as the matter density and Hubble constant. Time delays are most useful when observations permit detailed lens modeling and variability studies, requiring high resolution imaging, long time monitoring, and rapid cadence. We quantify the constraints possible between a sample of 150 such time delay lenses and a near term supernova program, such as might become available from an Antarctic telescope such as KDUST and the Dark Energy Survey. Adding time delay data to supernovae plus cosmic microwave background information can improve the dark energy figure of merit by almost a factor 5 and determine the matter density \\Omega_m to 0.004, Hubble constant h to 0.7%, and dark energy equation of state time variation w_a to 0.26, systematics permitting.

  13. Delayed transverse radiation myelitis in esophageal carcinoma

    Objective: To investigate the prevention and treatment of delayed transverse myelitis caused by radiotherapy in patients with thoracic esophageal carcinoma. Methods: Radical radiotherapy had been given to five patients (female 3, male 2) with thoracic esophageal carcinoma with delayed transverse myelitis developed 7 to 30 months after radiotherapy without any local recurrence. The study was done in an attempt to describe the clinical symptoms and signs. Analysis of causes was done to seek possible means of treatment and prevention. Results: Once delayed transverse myelitis had happened, it was not possible to cure. In this group, four patients died 1-2 years after myelopathy had occurred, and one was alive with functional neurological loss. Conclusions: Delayed transverse myelitis is an uncommon and serious complication induced by irradiation. It is very difficult to manage and indicates a very poor prognosis. The authors recommend precise radiation design and prudent performance for prevention

  14. Monolithic Time Delay Integrated APD Arrays Project

    National Aeronautics and Space Administration — The overall goal of the proposed program by Epitaxial Technologies is to develop monolithic time delay integrated avalanche photodiode (APD) arrays with sensitivity...

  15. Dry Mouth? Don't Delay Treatment

    ... For Consumers Home For Consumers Consumer Updates Dry Mouth? Don't Delay Treatment Share Tweet Linkedin Pin ... saliva, cavities may occur. back to top Dry Mouth Treatments Your doctor or dentist may recommend oral ...

  16. Lensing time delays and cosmological complementarity

    Time delays in strong gravitational lensing systems possess significant complementarity with distance measurements to determine the dark energy equation of state, as well as the matter density and Hubble constant. Time delays are most useful when observations permit detailed lens modeling and variability studies, requiring high resolution imaging, long time monitoring, and rapid cadence. We quantify the constraints possible between a sample of 150 such time delay lenses and a near term supernova program, such as might become available from an Antarctic telescope such as the KDUST and the Dark Energy Survey. Adding time delay data to supernovae plus cosmic microwave background information can improve the dark energy figure of merit by almost a factor 5 and determine the matter density Ωm to 0.004, the Hubble constant h to 0.7%, and the dark energy equation of state time variation wa to 0.26, systematics permitting.

  17. Nursing diagnosis of delayed surgical recovery

    Rosimere Ferreira Santana; Tallita Mello Delphino; Nathalia Martins Henriques; Priscilla Alfradique de Souza; Thais da Silva Soares; Shimmenes Kamacael Pereira

    2014-01-01

    The purpose of this study was to identify and analyze the nursing diagnosis of delayed surgical recovery, its defining characteristics and related factors according to NANDA-I taxonomy, through an integrative review. 34 articles were selected from MEDLINE, CINAHL, LILACS, and BDENF databases. In these, the delayed surgical recovery diagnosis was identified in a study. However, it was possible to identify the defining characteristics: difficulty to move about (36.4%) which requires help to com...

  18. Resource allocation for delay constrained wireless communications

    Chen, J.

    2010-01-01

    The ultimate goal of future generation wireless communications is to provide ubiquitous seamless connections between mobile terminals such as mobile phones and computers so that users can enjoy high-quality services at anytime anywhere without wires. The feature to provide a wide range of delay constrained applications with diverse quality of service (QoS) requirements, such as delay and data rate requirements, will require QoS-driven wireless resource allocation mechanisms to efficiently ...

  19. Delayed encephalopathy after acute carbon monoxide poisoning

    Mehmet İbrahim Turan; Atilla Çayır; Haşim Olgun

    2014-01-01

    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...

  20. Restarting delayed nuclear power plant projects

    The management of nuclear power plant projects with delays of several years with respect to the original scheduled commercial operation date presents particular issues and problem areas beyond the normal management tasks needed for projects implemented within originally planned schedules. During the years 1997-1998 the IAEA collected information and practical examples on necessary management actions to preserve the capability for resuming work and completing delayed nuclear power projects when conditions permit. The results were published in the IAEA-TECDOC-1110 entitled Management of Delayed Nuclear Power Plant Projects. As this publication was finalized, at the end of 1998, the available information at the IAEA PRIS (Power Reactor Information System) indicated that more than 40 nuclear power plant projects had delays of five or more years with respect to the originally scheduled operation dates. The PRIS data, collected at the end of 2007, illustrates a trend toward restarting and completing projects that were once delayed. The data indicates that the number of delayed nuclear power projects has reduced to about 25. Some practical methodologies and successful experience from the restarted projects were reviewed, summarized and included in the present publication. The purpose is to address the specific management issues pertaining to a delayed nuclear power project in the period after the decision for restarting is adopted. This publication covers those management issues not considered within the normal processes described in other IAEA publications. It is expected that the practical experience collected from delayed nuclear power projects that were successfully restarted, completed and brought to commercial operation, can provide useful assistance to the management of similar projects considering resumption of work in the future. This publication was produced within the IAEA programme directed to increase the capability of Member States for strengthening national

  1. Anharmonic resonances with recursive delay feedback

    Goldobin, Denis S.

    2011-01-01

    We consider application of the multiple time delayed feedback for control of anharmonic (nonlinear) oscillators subject to noise. In contrast to the case of a single delay feedback, the multiple one exhibits resonances between feedback and nonlinear harmonics, leading to a resonantly strong or weak oscillation coherence even for a small anharmonicity. Analytical results are confirmed numerically for van der Pol and van der Pol-Duffing oscillators. Highlights: > We construct general theory of ...

  2. Delayed chromosomal instability induced by DNA damage.

    Marder, B A; Morgan, W. F.

    1993-01-01

    DNA damage induced by ionizing radiation can result in gene mutation, gene amplification, chromosome rearrangements, cellular transformation, and cell death. Although many of these changes may be induced directly by the radiation, there is accumulating evidence for delayed genomic instability following X-ray exposure. We have investigated this phenomenon by studying delayed chromosomal instability in a hamster-human hybrid cell line by means of fluorescence in situ hybridization. We examined ...

  3. Statistical Module Level Area and Delay Estimation

    Akhilesh Tyagi

    1997-01-01

    The increasing complexity of VLSI design process has led to an increasing use of layout synthesis systems. For many components of a high-level synthesis system such as module generators and module generator development environments, an accurate model of area and delay for the layouts generated by a layout synthesis system is extremely desirable. We have experimented with a statistical model for area and delay of function modules. This model is surprisingly accurate for a standard cell based l...

  4. Delayed stoma formation in Fournier's gangrene.

    Bronder, C S; Cowey, A; Hill, J

    2004-11-01

    Fournier's gangrene is traditionally treated with prompt surgical debridement and in many cases a diverting colostomy is also fashioned during the same procedure. We present four cases where stoma formation was delayed until the second look procedure. The physiological states at the time of either procedure were compared using POSSUM. The results showed an improvement in the physiological condition in all patients at the time of the second operation, suggesting that a delay can potentially improve prognosis in such cases. PMID:15521946

  5. Delay in diagnosis of congenital anal stenosis

    Weledji, Elroy P; Motaze Sinju

    2016-01-01

    Although a minor anorectal malformation the delay in diagnosis and treatment of anal stenosis may result in significant early or late complications. Early inspection of the perineum in the neonate to pick up and correct anorectal malformation improves long term outcome but this requires proper anal examination or it could be missed. We present and discuss a case of delayed diagnosis of congenital anal stenosis (a low anorectal anomaly) with an imminent colonic perforation. Severe anal stenosi...

  6. NONEL High Precision MS Delay Detonator

    2001-01-01

    The NONEL high precision MS Delay Detonator (FDG-1detonator) is introduced. The main aspects about the FDG-1 detonator include the choice of structure, delay composition, control of the gas chamber, o ptimum charge and density, suitable explosives per meter in the NONEL tube, base firing charge and the main specifications. The improvement of the characteristics of FDG-1 detonator has been tested systematical ly. The testing method is reliable and its precision can meet the dema nd for usage.

  7. CHEMICAL EVOLUTION

    Calvin, Melvin

    1965-06-01

    How did life come to be on the surface of the earth? Darwin himself recognized that his basic idea of evolution by variation and natural selection must be a continuous process extending backward in time through that period in which the first living things arose and into the period of 'Chemical Evolution' which preceded it. We are approaching the examination of these events by two routes. One is to seek for evidence in the ancient rocks of the earth which were laid down prior to that time in which organisms capable of leaving their skeletons in the rocks to be fossilized were in existence. This period is sometime prior to approximately 600 million years ago. The earth is believed to have taken its present form approximately 4700 million years ago. We have found in rocks whose age is about 1000 million years certain organic molecules which are closely related to the green pigment of plants, chlorophyll. This seems to establish that green plants were already fluorishing prior to that time. We have now found in rocks of still greater age, namely, 2500 million years, the same kinds of molecules mentioned above which can be attributed to the presence of living organisms. If these molecules are as old as the rocks, we have thus shortened the time available for the generation of the complex biosynthetic sequences which give rise to these specific hydrocarbons (polyisoprenoids) to less than 2000 million years.

  8. Difference methods for stiff delay differential equations

    Delay differential equations of the form y'(t) = f(y(t), z(t)), where z(t) = [y1(α1(y(t))),..., y/sub n/(α/sub n/(y(t)))]/sup T/ and α/sub i/(y(t)) less than or equal to t, arise in many scientific and engineering fields when transport lags and propagation times are physically significant in a dynamic process. Difference methods for approximating the solution of stiff delay systems require special stability properties that are generalizations of those employed for stiff ordinary differential equations. By use of the model equation y'(t) = py(t) + qy(t-1), with complex p and q, the definitions of A-stability, A( )-stability, and stiff stability have been generalize to delay equations. For linear multistep difference formulas, these properties extend directly from ordinary to delay equations. This straight forward extension is not true for implicit Runge-Kutta methods, as illustrated by the midpoint formula, which is A-stable for ordinary equations, but not for delay equations. A computer code for stiff delay equations was developed using the BDF. 24 figures, 5 tables

  9. Introduction to attosecond delays in photoionization

    This tutorial presents an introduction to the interaction of light and matter on the attosecond timescale. Our aim is to detail the theoretical description of ultra-short time delays and to relate these to the phase of extreme ultraviolet (XUV) light pulses and to the asymptotic phaseshifts of photoelectron wave packets. Special emphasis is laid on time-delay experiments, where attosecond XUV pulses are used to photoionize target atoms at well-defined times, followed by a probing process in real time by a phase-locked, infrared laser field. In this way, the laser field serves as a ‘clock’ to monitor the ionization event, but the observable delays do not correspond directly to the delay associated with single-photon ionization. Instead, a significant part of the observed delay originates from a measurement induced process, which obscures the single-photon ionization dynamics. This artefact is traced back to a phaseshift of the above-threshold ionization transition matrix element, which we call the continuum-continuum phase. It arises due to the laser-stimulated transitions between Coulomb continuum states. As we shall show here, these measurement-induced effects can be separated from the single-photon ionization process, using analytical expressions of universal character, so that eventually the attosecond time delays in photoionization can be accessed.

  10. Ignition Delay Studies on Hypergolic Fuel Grains

    S. R. Jain

    1988-07-01

    Full Text Available The ignition delays of several solid hypergolic fuel compositions, casted using various polymeric binders, or as melts, have been determined with fuming nitric acid as oxidizer. The ignition delays of various hypergolic fuel compositions increase drasticaliy on casting with binders like. carboxyl or hydroxyl termninated polybutadiene. Fuel grains cast using some newly syhthesised epoxy  resins with other ingrcdients, such as curing agent, magnesium powder and fuel, have short ignition delays of the order of 200 ms, and also good mechanical strength. Increasing the amount of binder in the composition retards the hypergolicity of the rain. Similar studies have been made on melt-cast systems using low melting hypergolic fuels for casting fuel powders. The ignition delays of the melt-cast grains, are longer than those determined taking the composition in the powder form. The effect of highly hypergolic additives, and metal powders, on the ignition delay of the cast compositions has been determined. Grains having good mechanical strength and short ignition delays have been obtained by optimising the fuel grain composition.

  11. Speech and language delay in children.

    McLaughlin, Maura R

    2011-05-15

    Speech and language delay in children is associated with increased difficulty with reading, writing, attention, and socialization. Although physicians should be alert to parental concerns and to whether children are meeting expected developmental milestones, there currently is insufficient evidence to recommend for or against routine use of formal screening instruments in primary care to detect speech and language delay. In children not meeting the expected milestones for speech and language, a comprehensive developmental evaluation is essential, because atypical language development can be a secondary characteristic of other physical and developmental problems that may first manifest as language problems. Types of primary speech and language delay include developmental speech and language delay, expressive language disorder, and receptive language disorder. Secondary speech and language delays are attributable to another condition such as hearing loss, intellectual disability, autism spectrum disorder, physical speech problems, or selective mutism. When speech and language delay is suspected, the primary care physician should discuss this concern with the parents and recommend referral to a speech-language pathologist and an audiologist. There is good evidence that speech-language therapy is helpful, particularly for children with expressive language disorder. PMID:21568252

  12. Optimal Control with Time Delays via the Penalty Method

    Mohammed Benharrat

    2014-01-01

    Full Text Available We prove necessary optimality conditions of Euler-Lagrange type for a problem of the calculus of variations with time delays, where the delay in the unknown function is different from the delay in its derivative. Then, a more general optimal control problem with time delays is considered. Main result gives a convergence theorem, allowing us to obtain a solution to the delayed optimal control problem by considering a sequence of delayed problems of the calculus of variations.

  13. Boolean Delay Equations: A simple way of looking at complex systems

    Ghil, Michael; Zaliapin, Ilya; Coluzzi, Barbara

    2006-01-01

    Boolean Delay Equations (BDEs) are semi-discrete dynamical models with Boolean-valued variables that evolve in continuous time. Systems of BDEs can be classified into conservative or dissipative, in a manner that parallels the classification of ordinary or partial differential equations. Solutions to certain conservative BDEs exhibit growth of complexity in time. They represent therewith metaphors for biological evolution or human history. Dissipative BDEs are structurally stable and exhibit ...

  14. Finite-dimensional global attractors for parabolic nonlinear equations with state-dependent delay

    Chueshov, I.; Rezunenko, Oleksandr

    2015-01-01

    Roč. 14, č. 5 (2015), s. 1685-1704. ISSN 1534-0392 R&D Projects: GA ČR GAP103/12/2431 Institutional support: RVO:67985556 Keywords : Parabolic evolution equations * state-dependent delay * global attractor * finite-dimension * exponential attractor Subject RIV: BC - Control Systems Theory Impact factor: 0.844, year: 2014 http://library.utia.cas.cz/separaty/2015/AS/rezunenko-0444705.pdf

  15. Improved delay-dependent stability criteria for time-delay systems

    Xu, S; Lam, J.

    2005-01-01

    This note provides an improved asymptotic stability condition for time-delay systems in terms of a strict linear matrix inequality. Unlike previous methods, the mathematical development avoids bounding certain cross terms which often leads to conservatism. When time-varying norm-bounded uncertainties appear in a delay system, an improved robust delay-dependent stability condition is also given. Examples are provided to demonstrate the reduced conservatism of the proposed conditions. © 2005 IE...

  16. Stability and Hopf Bifurcation of a Computer Virus Model with Infection Delay and Recovery Delay

    Haitao Song

    2014-01-01

    Full Text Available A computer virus model with infection delay and recovery delay is considered. The sufficient conditions for the global stability of the virus infection equilibrium are established. We show that the time delay can destabilize the virus infection equilibrium and give rise to Hopf bifurcations and stable periodic orbits. By the normal form and center manifold theory, the direction of the Hopf bifurcation and stability of the bifurcating periodic orbits are determined. Numerical simulations are provided to support our theoretical conclusions.

  17. Stability and Hopf Bifurcation of a Computer Virus Model with Infection Delay and Recovery Delay

    Haitao Song; Qiaochu Wang; Weihua Jiang

    2014-01-01

    A computer virus model with infection delay and recovery delay is considered. The sufficient conditions for the global stability of the virus infection equilibrium are established. We show that the time delay can destabilize the virus infection equilibrium and give rise to Hopf bifurcations and stable periodic orbits. By the normal form and center manifold theory, the direction of the Hopf bifurcation and stability of the bifurcating periodic orbits are determined. Numerical simulations are p...

  18. Delay-dependent stability of uncertain fuzzy large-scale systems with time delays

    In this paper the delay-dependent stability problem of the Takagi-Sugeno fuzzy large-scale system with time delays and parametric uncertainties is considered. Two delay-dependent robust stability criteria are proposed in terms of linear matrix inequalities (LMIs) by using the Lyapunov-Krasovskii functional method. Generalized Park's inequality is used to derive our results for bounding the cross term. Finally, numerical example is given to demonstrate the correctness and effectiveness of main theoretical results

  19. Network Effects, Congestion Externalities, and Air Traffic Delays: Or Why All Delays Are Not Evil

    Christopher Mayer; Todd Sinai

    2002-01-01

    We examine two factors that might explain the extent of air traffic delays in the United States: network benefits due to hubbing and congestion externalities. Airline hubs enable passengers to cross-connect to many destinations, thus creating network benefits that increase in the number of markets served from the hub. Delays are the equilibrium outcome of a hub airline equating high marginal benefits from hubbing with the marginal cost of delays. Congestion externalities are created when airl...

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

    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.

  1. Delay-dependent guaranteed cost control for uncertain systems with both state and input delays

    Xuanfang YANG; Wuhua CHEN; Huajing FANG

    2004-01-01

    This paper considers the guaranteed cost control problem for a class of uncertain linear systems with both state and input delays.By representing the time-delay system in the descriptor system form and using a recent result on bounding of cross products of vectors,we obtain new delay-dependent sufficient conditions for the existence of the guaranteed cost controller in terms of linear matrix inequalities.Two examples are presented which show the effectiveness of our approach.

  2. Design of a Novel Current Balanced Voltage Controlled Delay Element

    Pooja Saxena

    2014-04-01

    Full Text Available This paper presents a design of fast voltage controlled delay element based on modified version of low noise Current Balanced Logic (CBL. This delay element provides identical rising and falling edge delays controlled by the single control voltage. The post layout tunable delay range is from 140 ps to 800 ps over control voltage range of 0 to 2.1 V. An analysis for the delay element is also presented, which is in agreement with the simulated delays. A Delay Lock Loop (DLL is designed using this delay element to verify its performance.

  3. Apparatus and Method for Compensating for Process, Voltage, and Temperature Variation of the Time Delay of a Digital Delay Line

    Seefeldt, James (Inventor); Feng, Xiaoxin (Inventor); Roper, Weston (Inventor)

    2013-01-01

    A process, voltage, and temperature (PVT) compensation circuit and a method of continuously generating a delay measure are provided. The compensation circuit includes two delay lines, each delay line providing a delay output. The two delay lines may each include a number of delay elements, which in turn may include one or more current-starved inverters. The number of delay lines may differ between the two delay lines. The delay outputs are provided to a combining circuit that determines an offset pulse based on the two delay outputs and then averages the voltage of the offset pulse to determine a delay measure. The delay measure may be one or more currents or voltages indicating an amount of PVT compensation to apply to input or output signals of an application circuit, such as a memory-bus driver, dynamic random access memory (DRAM), a synchronous DRAM, a processor or other clocked circuit.

  4. Time-Delay Estimation using the Characteristic Roots of Delay Differential Equations

    Sun Yi

    2012-01-01

    Full Text Available Problem statement: For ordinary dynamic systems (i.e., non-delayed, various methods such as linear least-squares, gradient-weighted least-squares, Kalman filtering and other robust techniques have been widely used in signal processing, robotics, civil engineering. On the other hand, time-delay estimation of systems with unknown time-delay is still a challenging problem due to difficulty in formulation caused. Approach: The presented method makes use of the Lambert W function and analytical solutions of scalar first-order Delay Differential Equations (DDEs. The Lambert W function has been known to be useful in solving delay differential equations. From the solutions in terms of the Lambert W function, the dominant characteristic roots can be obtained and used to estimate time-delays. The function is already embedded in various software packages (e.g., MATLAB and thus, the presented method can be readily used for time-delay systems. Results: The presented method and the provided examples show ease of formulation and accuracy of time-delay estimation. Conclusion: Estimation of time-delays can be conducted in an analytical way. The presented method will be extended to general systems of DDEs and application to physical systems.

  5. Identification of nonlinear systems with unknown time delay based on time-delay neural networks.

    Ren, X M; Rad, A B

    2007-09-01

    In this letter, we address the problem of online identification of nonlinear continuous-time systems with unknown time delay based on neural networks (NNs). A novel time-delay NN model with learning algorithm is employed to perform simultaneous system identification and time-delay estimation. The proposed network is an extended version of the time-delay-free dynamical NN. Rigorous stability proof for the identification error is given by means of Lyapunov theory. The simulation studies are provided to demonstrate the performance of the identification algorithm and clarify the theoretical implications. PMID:18220203

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

    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

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

    Sun Jitao E-mail: sunjt@sh163.net

    2004-08-01

    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.

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

    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

  9. Community Evolution

    Bródka, Piotr; Kazienko, Przemysław

    2016-01-01

    The continuous interest in the social network area contributes to the fast development of this field. The new possibilities of obtaining and storing data facilitate deeper analysis of the entire social network, extracted social groups and single individuals as well. One of the most interesting research topic is the network dynamics and dynamics of social groups in particular, it means analysis of group evolution over time. It is the natural step forward after social community extraction. Having communities extracted, appropriate knowledge and methods for dynamic analysis may be applied in order to identify changes as well as to predict the future of all or some selected groups. Furthermore, knowing the most probably change of a given group some additional steps may be performed in order to change this predicted future according to specific needs. Such ability would be a powerful tool in the hands of human resource managers, personnel recruitment, marketing, telecommunication companies, etc.

  10. SUSCEPTIBILIDADE DE BOVINOS DAS RAÇAS JERSEY E GIR À ACIDOSE LÁCTICA RUMINAL: II - ACIDOSE METABÓLICAE METABOLIZAÇÃO DO LACTATO-L SUSCEPTIBILITY OF JERSEY AND GIR STEERS TO RUMEN LACTIC ACIDOSIS: II - METABOLIC ACIDOSIS AND L-LACTATE METABOLISM

    Celso Akio Maruta

    2002-02-01

    Full Text Available Quatro garrotes Jersey (J (Bos taurus e quatro Gir (G (Bos indicus foram utilizados para comparar a susceptibilidade de zebuínos e taurinos à acidose láctica ruminal (ALR. Neste trabalho, acompanhou-se o grau da acidose metabólica (AM e a metabolização do lactato-L. A ALR foi induzida com a administração de sacarose intraruminal. Amostras de sangue foram colhidas nos seguintes momentos: zero, 14, 16, 18, 20, 22 e 24 horas. Foram determinadas as concentrações de lactato total, de seus isômeros L e D e o perfil hemogasométrico. Nos momentos mais críticos observados (14ªh a 18ªh, a AM foi severa em ambas as raças, porém, ao término do experimento, esta passou a grau moderado nos garrotes G, mantendo-se severa nos J. Os animais J absorveram, do rúmen, maiores quantidades de lactato-D, o qual apresentou correlação negativa com o pH sangüíneo (r = - 0,78. Por outro lado, o lactato-L foi mais absorvido e utilizado nos bovinos G, contribuindo para a restauração parcial do equilíbrio ácido-básico e gerando alterações nas pCO2 e pO2. Os garrotes zebuínos da raça Gir apresentaram menor susceptibilidade à AM que os taurinos da raça Jersey.In order to compare the susceptibility to acute rumen lactic acidosis (RLA, four Jersey (J (Bos taurus and four Gir (G (Bos indicus steers were used to evaluate the degree of metabolic acidosis (MA and the metabolism of L-lactate during the RLA. The RLA was induced by the administration of sucrose into the rumen. Blood samples were collected at following times: zero, 14th,16th, 18th, 20th, 22nd and 24th h. Total lactic acid and its isomers, and blood gas determination were measured. At the most critical moments (14th to 18th h the MA was severe in both breeds, but the MA became moderate in the G steers and remained severe in the J steers at the end of the trial. Higher amounts of D-lactate was absorbed from the rumen to the blood of the J steers; the higher the D-lactate plasma level, the

  11. 10例HIV/AIDS患者HAART后继发高乳酸血症或乳酸酸中毒临床分析%Clinical analysis of hyperlactacidemia/lactic acidosis after receiving HAART in 10 HIV/AIDS patients

    黄维; 黄葵; 蓝珂; 邬剑威; 刘宁; 蒙江明

    2012-01-01

    目的 探讨HIV/AIDS患者高效抗反转录病毒治疗(highly active antiretroviral therapy,HAART)后继发高乳酸血症或乳酸酸中毒的临床表现和治疗方案.方法 回顾性分析10例HIV/AIDS患者HAART后继发高乳酸血症或乳酸酸中毒的临床表现、实验室检测结果和治疗效果等资料.结果 10例在继发高乳酸血症或乳酸酸中毒前均服用过含有核苷类反转录酶抑制剂(nucleoside reverse transcriptase inhibitors,NRTIs)组合的HAART方案,临床症状以乏力、恶心、腹胀、肌肉酸痛和呼吸困难多见,血乳酸浓度为5.14~10.74mmol/L,其中8例出现高乳酸血症或乳酸酸中毒的相关症状,2例未出现.6例经换药或停药处理后好转,4例死亡.结论 引起高乳酸血症或乳酸酸中毒的主要原因是使用含有NRTIs的组合方案,其中司他夫定最为常见,其次为齐多夫定.治疗时应立刻换药或停药.%Objective To investigate the clinical manifestations and treatment of HIV/AIDS patients who are affected with hy-perlactacidemia/lactic acidosis after receiving highly active antiretroviral therapy (HAART). Methods The clinical manifestations, laboratory findings and treatment efficacy were retrospectively analyzed in 10 HIV/AIDS patients who were affected with hyperlacta-cidemia/lactic acidosis after receiving HAART. Results All the 10 HIV/AIDS patients had received HAART regimens including nu-cleoside reverse transcriptase inhibitors (NRTIs) before being affected with hyperlactacidemia/lactic acidosis. The common clinical symptoms were fatigue, nausea, abdominal distension, muscle aches and difficulty of breathing. The blood lactic acid level of the 10 patients was 5.14-10.74 mmol/L, symptoms related to hyperlactacidemia/lactic acidosis occurring in 8 patients. Six patients were improved on cessation or switching to another medication, and 4 died. Conclusions The major cause that leads to hyperlactacidemia/ lactic acidosis is receiving HAART including

  12. Om religion og evolution

    Geertz, Armin W.

    kulturens kausale virkning på den menneskelige kognition og ikke mindst den hominine evolution. Ud fra, hvad vi ved om den menneskelige evolution, ses det, at den hominine evolution har en dybde, som sjældent medtænkes i teorier og hypoteser om den menneskelige evolution. Den menneskelige evolution er...

  13. Performansi Parameter Delay Pada Aplikasi Monitoring DIAMon

    Kurnia Ageng Pratama

    2013-03-01

    Full Text Available Kemampuan seorang administrator jaringan untuk mengawasi jaringan sangat penting agar jaringan tersebut dapat beroperasi dengan baik. Maka diperlukan aplikasi monitoring jaringan yang dapat memberikan informasi yang sedang terjadi pada jaringan tersebut, sehingga memudahkan administrator jaringan untuk mengatur dan bertindak agar jaringan tersebut memiliki kinerja yang baik. Salah satu parameter untuk menganalisa kondisi sebuah jaringan adalah delay. Metodologi pada tugas akhir ini dengan perancangan sistem terintegrasi monitoring delay dengan web aplikasi, pengujian monitoring delay dengan ping, pengambilan dan perhitungan statistik dari database MySQL, pengujian aplikasi monitoring DIAMon yang sudah terintegrasi dan penarikan kesimpulan dari pengujian dan hasil analisa data. Tugas akhir ini dibuat sebuah aplikasi monitoring DIAMon yang mampu mengukur delay dan ditampilkan dalam suatu dashboard yang komunikatif sehingga dapat membantu adminstrator jaringan bekerja. Dan didapatkan rata-rata selisih terbaik antara aplikasi monitoring DIAMon dengan PRTG yaitu 30,19853% dan terburuk yaitu 46,73768%. Sedangkan rata-rata selisih terbaik antara aplikasi monitoring DIAMon dengan perhitungan delay yaitu 57,79807% dan terburuk yaitu 91,69501%.  

  14. Computing using delayed feedback systems: towards photonics

    Appeltant, L.; Soriano, M. C.; Van der Sande, G.; Danckaert, J.; Massar, S.; Dambre, J.; Schrauwen, B.; Mirasso, C. R.; Fischer, I.

    2012-06-01

    Reservoir computing has recently been introduced as a new paradigm in the eld of machine learning. It is based on the dynamical properties of a network of randomly connected nodes or neurons and shows to be very promising to solve complex classication problems in a computationally ecient way. The key idea is that an input generates nonlinearly transient behavior rendering transient reservoir states suitable for linear classication. Our goal is to study up to which extent systems with delay, and especially photonic systems, can be used as reservoirs. Recently an new architecture has been proposed1 , based on a single nonlinear node with delayed feedback. An electronic1 and an opto-electronic implementation2, 3 have been demonstrated and both have proven to be very successful in terms of performance. This simple conguration, which replaces an entire network of randomly connected nonlinear nodes with one single hardware node and a delay line, is signicantly easier to implement experimentally. It is no longer necessary to construct an entire network of hundreds or even thousands of circuits, each one representing a node. With this approach one node and a delay line suce to construct a computational unit. In this manuscript, we present a further investigation of the properties of delayed feedback congurations used as a reservoir. Instead of quantifying the performance as an error obtained for a certain benchmark, we now investigate a task-independent property, the linear memory of the system.

  15. The use of delay in multitrack production

    Case, Alexander U.

    2003-04-01

    Delay, inevitable whenever sound propagates through space, is too often the bane of the acoustician's practice. An audible echo generally relegates a music performance hall-no matter how beautiful it otherwise might sound-to the lowest status. Multitrack music production on the other hand, with its aggressive use of overdubbing, editing, and signal processing, is not bound by those rules of time and space which determine the sound of a hall. In the recording studio, where music is synthesized for playback over loudspeakers, the delay is employed as a powerful, multipurpose tool. It is not avoided. It is in fact embraced. Echoes are used on purpose, strategically, to enhance the loudspeaker listening experience. Moreover, the humble delay is the basis for many nonecho effects. Flanging, chorus, and pitch shifting are delay-based effects regularly used in audio engineering practice. This paper discusses some of the more common delay-based effects, reviewing their technical structure, the psychoacoustic motivation behind them, and the musical value they create.

  16. Delayed Station Blackout Event and Nuclear Safety

    Andrija Volkanovski

    2015-01-01

    Full Text Available The loss of off-site power (LOOP event occurs when all electrical power to the nuclear power plant from the power grid is lost. Complete failure of both off-site and on-site alternating current (AC power sources is referred to as a station blackout (SBO. Combined LOOP and SBO events are analyzed in this paper. The analysis is done for different time delays between the LOOP and SBO events. Deterministic safety analysis is utilized for the assessment of the plant parameters for different time delays of the SBO event. Obtained plant parameters are used for the assessment of the probabilities of the functional events in the SBO event tree. The results show that the time delay of the SBO after the LOOP leads to a decrease of the core damage frequency (CDF from the SBO event tree. The reduction of the CDF depends on the time delay of the SBO after the LOOP event. The results show the importance of the safety systems to operate after the plant shutdown when the decay heat is large. Small changes of the basic events importance measures are identified with the introduction of the delay of the SBO event.

  17. Effect of Delay on Children's Delay-Execute Prospective Memory Performance

    Rendell, Peter G.; Vella, Melissa J.; Kliegel, Matthias; Terrett, Gill

    2009-01-01

    To date, little work has been done investigating prospective memory in children, particularly using a delay-execute paradigm. Two experiments were conducted to investigate this issue with children aged 5-11 years. While playing a computer driving game, children's ability to carry out a delayed intention either immediately a target cue appeared or…

  18. Improved LMI representations for delay-independent and delay-dependent stability conditions

    Yingmin JIA; Hideki Kokame

    2003-01-01

    Some new linear matrix inequality (LMI) representations for deley-independent and delay-dependent stability conditions are obtained by introducing additional matrices and eliminating the product coupling of the system matrices and the Lyapunov matrices. The results improve conservativeness of the given conditions for the analysis and the design of time-delay systems with polytopic-type uncertainty.

  19. A novel criterion for delayed feedback control of time-delay chaotic systems

    This paper investigated stability criterion of time-delay chaotic systems via delayed feedback control (DFC) using the Lyapunov stability theory and linear matrix inequality (LMI) technique. A stabilization criterion is derived in terms of LMIs which can be easily solved by efficient convex optimization algorithms. A numerical example is given to illuminate the design procedure and advantage of the result derived

  20. Global exponential synchronization of nonlinear time-delay Lur'e systems via delayed impulsive control

    Chen, Wu-Hua; Wei, Dan; Lu, Xiaomei

    2014-09-01

    This paper is concerned with the global exponential synchronization problem of two identical nonlinear time-delay Lur'e systems via delayed impulsive control. Some novel impulsive synchronization criteria are obtained by introducing a discontinuous Lyapunov function and by using the Lyapunov-Razumikhin technique, which are expressed in forms of linear matrix inequalities. The derived criteria reveal the effects of impulsive input delays and impulsive intervals on the stability of synchronization error systems. Then, sufficient conditions on the existence of a delayed impulsive controller are derived by employing these newly-obtained synchronization criteria. Additionally, some synchronization criteria for two identical time-delay Lur'e systems with impulsive effects are presented by using delayed continuous feedback control. The synchronization criteria via delayed continuous feedback control can deal with the case when the impulsive control strategy fails to synchronize two identical impulsive time-delay Lur'e systems. Three numerical examples are provided to illustrate the efficiency of the obtained results.